Tolerance to high ultrafiltration rates during closed batch hemodialysis. The tolerance to high levels of ultrafiltration that has been observed when using a RP-6 dialyzer with polyacrylonitrile membrane and a closed batch dialysate delivery system has led the authors to put patients on a free sodium and fluid intake. Eight patients were put on such a diet for six months. They have been dialyzed four to five hours, three times per week, on a RP-6-Rhodial 75. The mean intersession weight gain was 4.29+/-0.18 Kg after three days for a mean predialytic body weight of 63.55+/-2.54 Kg. Mean predialytic blood pressure was 1.38+/-4 mmHg for systolic pressure and 82+/-5 mmHg for diastolic pressure. Mean ultrafiltrate volume was 4.86+/-0.36 liters which corresponds to a sodium output of 661.3+/-49.5 mEq. Total plasma protein and hematocrit increased 18.8+/-3.34% and 19.13+/-3.22%, respectively, when the pre and post-dialytic values were compared. No clinical sign of fluid overload (dyspnea, edema, etc.) was noted in these patients. Cardiothoracic index remained in the normal range. This tolerance is due, possibly, to the high sodium concentration (145 mEq/L) in the dialysate. The free sodium and water diet may contribute to a better rehabilitation.


Scanning electron microscopic evaluation of the surfaces of artificial hearts. This report summarizes the surface changes seen in artificial hearts implanted in calves for periods up to four months. Fabrication defects as well as degradation resulting from wear are identified. SEM evaluation of the blood contacting surface as well as the surface of the diaphragm associated with the drive mechanisms has revealed potential problems with current heart designs and methods of fabrication. Materials evaluation of implanted hearts is crucial for a clinically useful system to evolve.


Molecular, microscopic, microstructural and mechanical methods of analyzing pseudoneointimal linings within partial artificial hearts in man and the calf. Ex vivo molecular, microscopic (cellular), microstructural and mechanical methods have been utilized to evaluate biologic, blood-interfacing linings (pseudoneointimal) formed on textured, fibril-flocked pumping surfaces within abdominal left ventricular assist devices (ALVADs) on partial artificial hearts. Thus far, seventeen human and twenty bovine pseudoneointimal linings (1--28 day pumping durations) have been evaluated by these methods. The results indicate that pseudoneointima begins developing within 24 hours after contact of the pumping surface with blood and is well developed at five days. The linings exhibit surface immunofluorescent fibrinogen activity, viable surface macrophages and histiocytes and scattered erythrocytes at ALVAD removal. Structurally similar linings (20 micrometer to 500 micrometer in thickness) develop in calves and in man. Mechanically, pseudoneointima is a stable, adherent, highly compliant, isotropic structural material. It is linearly elastic and strain-rate independent, with small viscous energy losses under physiologic strains. The methods employed for the evaluation of pseudoneointima provide useful information to determine the suitability of textured or rough surfaces for blood interfacing. The cumulative results indicate that the textured surface approach is useful for intermediate-term clinical ALVAD utilization.


Blood plasma/implant interfaces FT--IR studies of adsorption on polyethylene and heparin-treated polyethylene surfaces. Described is an attenuated total reflection (ATR), Fourier Transform infrared (FT--IR) technique useful for studying the adsorption of blood plasma proteins onto polymer surfaces. This technique had the advantage of employing whole blood plasma and has detected differences between the species adsorbed onto heparin-treated polymers as compared to the species adsorbed on untreated polymers. Differences detected consist of 1) changes in conformation and/or composition of proteins adsorbed on treated and untreated polymers, and 2) changes in amounts of carbohydrate-containing materials on the treated and untreated polymer surfaces. The advantages of FT-IR are its extreme sensitivity and its ability to work with highly complex systems such as whole blood plasma. These abilities should be of great value for providing direct molecular level information concerning protein adsorption from intact blood systems.


Ataxia telangiectasia.

Ataxia telangiectasia. Ataxia telangiectasia has been described as a single-gene autosomal recessive disorder. It affects multiple systems. Several attempts to present an etiological hypothesis that will account for the multisystem involvement have been made. Those reviewed haer are (1) aberration of inductive signaling, which is predicted on a deficient mesoderm, leading to vascular and thus multiorgan effects (a critical timing of events is a basic assumption); (2) developmental imbalance, based on multisystem supression of embryological development; (3) the autoimmune hypothesis, which requires the presence of a cell surface antigen on thymic and nerve cells analogous to the thy 1.1 antigen of mouse and rat. The development of cytotoxic autoantibody to this antigen is postulated as an explanation of the pathogenesis.


Common origin of rods, cores, miniature cores, and focal loss of cross-striations. Twelve patients suffering from congenital neuromuscular disorders showed at least two of the following structural changes in their muscle biopsy specimens: rods, cores, miniature cores (M lesions), and focal loss of cross-strians (F lesions). There appeared to be no essential differences between M and F lesions except for the presence of vesicular nuclei in and around the latter. A striking finding was the presence of adjacent M lesions, F lesions, or both in two or several adjoining muscle fibers. Serial sections often showed a definite relationship of the lesions with blood vessels. The finding of rods cores, and M and F lesions, not only in one biopsy specimen but also in one muscle fiber, raised the intriguing possibility of common pathogenic mechanisms producing these lesions.


Intracranial pressure reserve testing. A study in experimental animals. Quantitating cerebral "elastance" or "ICP reserve" has added considerably to the value of continuous monitoring of intracranial pressure (ICP). Intracranial pressure reserve is a measure of the capacity of the brain's natural compensatory mechanisms for countering increases in ICP secondary to increases in intracranial volume. Intracranial pressure reserve testing was studied in dogs with known volumes of extracerebral intracranial mass, both in normal and in edematous brains and at various ICPs. Ten thousand measurements were made with five different methods of measuring ICP reserve. Testing when multiple increments of subdural saline infusion were used over a five-minute period to quantitate ICP reactivity to volumetric stress seemed most reliable and most adaptable to clinical application. Methods of measuring cerebral "elastance" using only a single subdural infusion proved to be variable and difficult to read.


Erythrocyte metabolism in muscular dystrophy. Erythrocytes from patients with Duchenne's and myotonic muscular dystrophies contained more adenosine triphosphate (ATP) and produced more lactate than did normal erythrocytes in incubation studies conducted in vitro at an initial pH of 7.4. Since the same results were obtained in two different genetic dystrophies, these metabolic variations appear to be secondary to the primary changes occurring in these diseases. Following ouabain treatment, ATP content increased and lactate production decreased in erythrocytes from both dystrophies. This result differs from one reported earlier in experiments conducted at alkaline pH.


Computerized axial tomography and cerebral scintigraphy in leukodystrophy. A study of two boys presumably suffering from lysosomal disease. Two unrelated boys, 12 and 9 years old, suffered from a diffuse cerebral disease that followed a parallel, subacute course. Mental regression, loss of hearing and vision, spastic-ataxic and pseudobulbar disturbances, and atrophy of the optic nerves occurred in both. Enzyme studies and the liver biopsy of one of the patients suggest a "lysosomal disease." The hallmark of both patients is the striking similarity of the cerebral scintigraphy and the computerized axial tomography (CT). Cerebral scintigraphy showed annular and crescent-shaped areas of increased radioactivity in the parietoccipital region. The CT indicated bilateral, symmetric bands of elevated density after contrast enhancement in the paraventricular white matter in the same region. These findings and the neurologic symptoms are compatible with leukodystrophy. Thus cerebral scintigraphy and CT appear to be useful aids in the diagnosis of metabolic brain disease. Computerized axial tomography is preferred for distinguishing whether lesions are in white or gray matter.


The lissencephaly (agyria) syndrome in siblings. Computerized tomographic and neuropathologic findings. Two consecutive nontwin siblings had the lissencephalic syndrome. The literature of this syndrome in siblings is reviewed, and the somatic and clinicopathologic features and delineated further. Computerized tomography is reported for the first time to our knowledge in this entity as an important, nonivasive, and possibly specific test. Diagnosis early in life is possible for adequate management of the patients and genetic counseling.


Isolated benign cerebral vasculitis.

Isolated benign cerebral vasculitis. A young woman south medical care for headache, nausea, and evolving focal neurologic signs. The CSF was normal; cerebral angiography showed segmental narrowing and irregularity of intraparenchymal arterioles. Isolated cerebral vasculitis was the clinical diagnosis made by careful exclusion; the illness reponded well to steroids and there was later angiographic evidence of healing.


Use of discriminant analysis. II. Identification of persons with glaucomatous visual field defects. Thirty-three ocular, systemic, and laboratory variables were used in a discriminant analysis to separate 219 patients suffering from chronic open-angle glaucoma from 100 people who did not have the disease. The analysis used seven of the variables to separate 93% of the patients correctly. Without intraocular pressure, a 90% separation was obtained.


Small melanomas of the choroid.

Small melanomas of the choroid. We reviewed 38 cases of small choroidal melanomas on file in the Eye Pathology Laboratory of Bascom Palmer Eye Institute, Miami. Clinical and histopathological features of these cases were noted, and clinical follow-up information was obtained for 36 (95%) of the patients. Two tumor deaths occurred among the 18 patients that had a possible follow-up period of six years of more, yielding a tumor death rate of 11%. Retrospective analysis of clinical records and photographs permitted us to correlate the presence or absence of documented tumor growth with the degree of mitotic activity.


The disc sign in sickling hemoglobinopathies. The disc sign is the presence of dark red spots on the optic disc of patients with a sickling hemoglobinopathy. The dark spots appear to be plugs of deoxygenated erythrocytes in small surface disc vessels. The occlusions, which are transient and do not produce clinically detectable visual impairment, were seen most often in patients with homozygous sickle cell anemia and may be the result of clogging of small vessels by irreversibly sickled erythrocytes.


The iris sphincter in aberrant regeneration of the third nerve. Fourteen patients with aberrant regeneration of the third cranial nerve were examined using self-developing photographs, motion pictures, and pupillography. These pupillary phenomena were noted: (1) sector contractions of the iris sphincter in response to light, (2) sector contractions of the iris sphincter associated with eye movements, and (3) an abnormal pupillary unrest. The observations strongly support the concept that after injury, fibers regenerate and sprout collateral branches that finally reach muscles of the oculomotor group other than those originally innervated.


Autosomal recessively inherited ocular albinism. A new form of ocular albinism affecting females as severely as males. A new form of ocular albinism, autosomal recessively inherited ocular albinism (AROA), was studied in seven females and two males from five unrelated Caucasian kindreds. Affected patients have the impaired vision, translucent irides, congenital nystagmus, photophobia, albinotic fundi with hypoplasia of the fovea, and strabismus that are also found in X-linked ocular albinism (XOA). Unlike XOA, however, this form of ocular albinism is inherited as an autosomal recessive trait, with females affected as severely as males. Obligate heterozygotes of AROA lack the ocular abnormalities that are present in females heterozygous for XOA. Also, skin and hairbulb biopsy specimens do not reveal any abnormalities in patients with AROA, whereas giant pigment granules are found in patients heterozygous and hemizygous for XOA. The recognition of this disorder is imperative for proper diagnosis and responsible genetic counseling.


Grating test of contrast sensitivity in patients with retrobulbar neuritis. A retrospective study of 57 patients with retrobulbar neuritis (RBN) was carried out with a new test of contrast sensitivity that utilizes printed sinusoidal gratings. For 21 patients suffering from multiple sclerosis, visual abnormality was detected in 18 "affected" eyes and 12 apparently unaffected eyes. For the 36 patients with RBN, abnormalities were detected in 29. In seven of these cases, the grating test showed bilateral impairment. The grating test seemed to be a more sensitive indicator of demyellinization than other psychophysical tests. In 24 of the patients with the least severe disease, the grating test was compared with the visual evoked response. The probability of making a positive diagnosis was .54 for the evoked potential alone, and .71 for the grating test alone.


Vitamin A-responsive panocular xerophthalmia in a healthy adult. An unusual case of classical xerophthalmia occurred in an otherwise healthy, well-nourished, 25-year-old woman. She had marked conjunctival and corneal xerosis, including early stromal edema, evolving pigmentary alterations of the retinal pigment epithelium, and notable constriction of her visual fields, which paralleled the distribution of the retinal lesions. Abnormalities of the conjunctiva, cornea, and visual fields disappeared within two weeks of oral vitamin A therapy, and 1 1/2 months later, many of the retinal lesions cleared as well. This case supports the primacy of isolated vitamin A deficiency in the etiology of corneal xerosis and "fundus xerophthalmicus"; demonstrates that stromal edema is an important early component of corneal involvement; and localizes the funduscopic abnormalities to the retinal pigment epithelium.


Intraocular penetration of topical clindamycin in rabbits. II. Clindamycin phosphate. We have obtained comparative data for the intraocular absorption of topically administered clindamycin hydrochloride hydrate and clindamycin phosphate, made feasible with a new gas chromatographic method of analysis. Results indicated that clindamycin phosphate underwent hydrolysis in the eye, liberating the biologically active clindamycin. However, topical clindamycin hydrochloride produced higher levels (two to six times more) of the antibiotic than those achievable with the phosphates ester in the uvea, aqueous humor, and cornea, presumably due to clindamycin hydrochloride's higher lipid solubility. Based on this data, clindamycin hydrochloride appears to be the preferred form of the antibiotic for topical ocular applications.


Human posterior subcapsular cataract. A gross and flat preparation study. Fifteen human lenses with posterior subcapsular cataracts (PSC) were examined en bloc and in flat preparations of the posterior capsules. The PSCs were polygonal to stellate in shape, showing some correlation with the sutural pattern. Most PSCs had a thin, semiliquefied zone centrally. All lenses showed superficial epithelial cells migrating posteriorly from one or more sectors of the equator. In these sectors, the epithelial nuclei were enlarged, with complete disorganization of the postequatorial nuclear rows. The migrating cells were stellate, layered, and in the larger cataracts, were oriented in a ring configuration around the liquefied central portion of the PSC and bladder and other proliferative cells tended to accumulate around the ring area. Control cataractous and aging lenses showed considerable irregularity of the postequatorial nuclear rows but only occasional migration toward the posterior pole.


The structural basis of altered vascular permeability following intraocular inflammation. An immunogenic uveitis was produced in rabbits by the intravitreal injection of bovine gamma-globulin. Four to six months later, an alteration in vascular permeability was determined by greater accumulation of iodinated I 125 serum albumin in the previously inflamed eye than in the normal eye. An altered vascular permeability was found only in eyes with profound structural changes. Possible sites of extravascular protein leakage were: (1) proliferated blood vessels in the posterior chamber and vitreous; and (2) leakage through the disrupted and scarred ciliary epithelium. In eyes without evidence of altered vascular permeability, a persistent chronic inflammation was observed, and gliosis and chorioretinal scarring was prominent.


Treatment of negative middle ear pressure and serous otitis media with Politzer's technique. An old procedure revisited. This study sought to monitor changes in middle ear pressure with tympanometry after a simplified home politzerization maneuver in children who had excessive negative intratympanic pressure and/or serous otitis media. The mean middle ear pressure for 23 children was -201 mm H2O, whereas seven subjects displayed a flat tympanogram that was consistent with the medical diagnosis of serous otitis media. Middle ear pressure measurements with tympanometry at five and ten minutes after politzerization indicated successful tympanic ventilation in 91% and 85% of the ears, respectively. For children with negative intratympanic pressures of -250 mm H2O, data suggested that ventilation was sustained for at least 30 minutes. In general, results lend support for using home politzerization as an alternative or associative treatment in children with high negative pressure and/or serous otitis media.


Cervicofacial actinomycosis. Rapid diagnosis by thin-needle aspiration. Thin-needle aspiration cytology is a well-known minimally invasive technique that is used in the diagnosis of neoplastic disease. The same biopsy technique provides a means for immediate identification of actinomycosis. Aspiration specimens may be used for morphologic studies, as well as for microbiologic isolation. The diagnostic histologic feature of sulfur granules remains intact with this cytologic aspiration technique. This technique is a safe, simple, and rapid means of diagnosing actinomycosis and appears to have value in the diagnosis of other infectious diseases as well.


Two years of a program in hearing-aid-related services. A program of hearing-aid-related services is described in which a dispenser of hearing aids visits an audiology facility on a regular basis as a supplier. Surveys to assess the program were conducted during a two-year period. Of the 128 patients who participated in the study, 89% continued wearing their hearing aids during the first year and 86% during the second year. The adjustment period of about 30 days with an accompanying orientation program was crucial. Ear mold considerations and use of the hearing aid during noisy situations constituted two major problem areas. Five aids were returned to the factory during the adjustment period, six during the first year, and 15 during the second year. Group work in hearing aid evaluation and orientation was a positive factor.


Prognostic importance of the tumor-free laryngectomy specimen. In a review of 500 consecutive laryngectomies, 36 specimens were found with no tumor. All patients had received radiation treatment preoperatively. Patients with small primary tumors and no tumor evident in microscopically examined lymph nodes had excellent long-term survival. Those patients with extensive (T4) primary tumors or with tumor found microscopically in their lymph nodes had poor survival statistics. This information reconfirms the known limitations of radiation and surgery in the case of the patient with advanced head and neck cancer. Hopefully, adjuvant chemotherapy or immunotherapy will improve the survival of these patients.


Middle component averaged electroencephalic responses to tonal stimuli from normal neonates. Initial report. Tone-pips, centered at 1,000 Hz, were used to elicit middle component averaged electroencephalic responses (AERs) (8 to 90 ms) from five normal neonates. The stimuli were presented monaurally at 10-, 30-, and 50-dB HL, with regard to adult behavioral thresholds. Averaged electroencephalic responses were also derived for no-stimulus control conditions. The initial portion of the stimulus-elicited AER waveforms was similar to that obtained from adults. An objective, scoring procedure, based on predetermined rules, was used to determine peak latencies and to quantify point-to-point amplitudes. Inspection of the scored data revealed that latencies decreased and amplitudes increased as the stimulus magnitude increased, as has also been reported for adults. Unlike adult responses, the middle components from the neonates in this study were identifiable only when recorded from the side of the head ipsilateral to the ear stimulated.


So-called hairy polyps or teratoid tumors of the nasopharynx. Two new cases of hairy polyp of the nasopharynx, one with congenital atresia of the left carotid artery, are added to 111 cases that have already been reported. Unlike trigerminal neoplastic teratomas, the hairy polyps are derived from two germ cells, the ectoderm and mesoderm. They are composed of a conglomeration of disorganized and disorderly tissues that form a sessile to a pedunculated mass that is attached to the nasopharynx. They are strictly developmental anomalies in early embryogenesis with very limited growth potential. We discuss their clinical features, diagnosis, and development. In an evaluation of any nasopharyngeal mass in the newborn, consideration should be given as to whether the mass arises in the nasopharynx or is an extracranial extension of glioma or encephalocele.


Unusual vascular lesions of the neck.

Unusual vascular lesions of the neck. Vascular lesions of the neck may initially appear atypically, without the expected findings of a bluish discoloration, pulsations, or a bruit. The initial characteristics may mimic that of a metastatic carcinoma. The true nature of the lesion may remain obscure, despite a thorough preoperative evaluation, including angiography. The head and neck surgeon must be aware of the occasional unusual appearance and must be prepared to treat whatever vascular lesion he might encounter.


Management of tracheocutaneous fistula.

Management of tracheocutaneous fistula. In our experience, recommended treatment of the closure of tracheocutaneous fistula has been disappointing. Complications associated with primary closure, which we have experienced, include pneumomediastinum, pneumothorax, and wound breakdown. The alternate method of treating tracheocutaneous fistula, which we recommend, consists of excision of the tract down to the level of the trachea and allowing healing to take place via secondary intention. Elective scar revision, if indicated, is scheduled at some time in the future.


Eighth nerve in acoustic neuromas. Special reference to superior vestibular nerve function and histopathology. Eighth nerve specimens were removed during acoustic neuroma surgery, and findings were related to cochlear and especially to superior vestibular nerve function as studied by conventional caloric testing in 21 cases. The origin of the tumor was in eight cases the inferior and in two cases the superior vestibular nerve, and in eight cases the vestibular nerve without more specific localization. In three advanced cases the exact site of origin could not be determined. Leaving age-related changes out of account, the utricle and horizontal canal ampulla appeared normal in all ears except one in which the ampulla was replaced by tumor tissue. In 11 ears the superior vestibular nerve was histologically intact and three of these ears also showed normal caloric responses. In seven ears there was a canal paresis, and in three no reaction was obtained. The ten ears with partial or total nerve invasion by tumor either showed a weak reaction or no response at all. It is likely that an early conduction block arises in both cochlear and vestibular nerves, and reduced reactions to appropriate stimuli do not warrant conclusions that the numbers of anatomically intact nerve fibers possibly are reduced.


Hemifacial atrophy. A review of an unusual craniofacial deformity with a report of a case. Progressive hemifacial atrophy is an unusual craniofacial deformity that is amenable to surgical reconstruction. The disease may involve any layer of the superficial facial tissues as well as cartilage and bone. While the cause of the disease is unknown, several hypotheses exist to account for the progressive nature of the disorder. Histologically, the skin undergoes thinning of the Malpighian stratum and atrophy of the skin adenexa and dermal units. The subcutaneous tissue shows chronic inflammatory changes. This picture closely resembles that of scleroderma, and some authors believe the disorder to be an isolated form of scleroderma. Various hypotheses have been promulgated as to the cause of this disorder, its pathologic process, and varied clinical presentation.


Advantage of computerized tomography scan. Diagnosis of an otogenic cerebellar abscess. Computerized axial tomography with contrast enhancement is very useful for the diagnosis of brain abscesses. This fact is illustrated by a case report of a cerebellar abscess secondary to chronic mastoiditis with cholesteatoma.


Comparison of hearing threshold determined by auditory pathway electric responses and by behavioural responses. In order to evaluate their reliability for determing the hearing threshold, the cochlear microphonic potentials, the auditory nerve and brain stem neural evoked responses as well as the cortical evoked responses were compared with the behavioural hearing thresholds of the same subjects in the same session. The threshold for recording the cochlear microphonic potnetial was found to be appreciably higher than the behavioral threshold. The threshold for recording the auditory nerve and brain stem responses was within a few decibels of the behavioural threshold. The thresold of the cortical evoked response was several decibels higher. It is concluded that (1) the auditory nerve and brain stem neural evoked responses are the best indicators of hearing threshold; (2) the cortical evoked responses are usually comparable, and (3) all types of evoked responses are indispensable aids in the evaluation of hearing and the determination of site of lesion in the auditory system.


Backward and forward masking in listeners with severe sensorineural hearing loss. Using synthetic stimuli, backward and forward masking by a first-formant stimulus were measured for two tasks: (1) discrimination of a second-formant transition and (2) pure-tone detection. 16 listeners with moderate to severe sensorineural hearing impairment were studied. Many of the listeners showed backward and forward discrimination masking, sometimes extending as far as 200 ms before or after the first-formant interval. There were large individual differences in degree and temporal extent of masking. The masking contribution of sensitivity shifts, as indicated by pure-tone detection levels, appeared to be limited to a range of only 50 ms before or after the first-formant masker.


[Remote masking as a test of cochlear conductive hearing losses (author's transl)]. The authors studied the remote masking (RM) in patients with Menière's disorder during the hearing loss fluctuations produced either by the disorder or by the glycerol test (Klockhoff). The RM was recorded for pulsed tones of 250, 500 and 1 000 Hz; the masker was a continuous narrow-band noise centered at 3 000 Hz, with 305 Hz (2 875-3 180 Hz) bandwidth, delivered at an overall level of 98 dB SPL. The results showed that the RM decreases during the acute phase, i.e. when the hearing loss increases, and, increases if the glycerol tests do not significantly modify the RM value. They seem to confirm the hypothesis that the RM may be due to a mechanical effect in the internal ear and suggest the possibility of using the RM as a test of end-organ rigidity.


Effect of homolateral and contralateral routing of signals through body-worn hearing aids on the localization ability of hearing-impaired people. This investigation compared the localization abilities in the horizontal plane of 22 hearing-impaired adults (9 with symmetrical conductive and 13 with symmetrical sensorineural hearing impairment) whilst listening to speech through body-worn hearing aids in two different ways: (a) hearing-aid microphone placed on the same side as the stimulated ear (homolateral routing of signals); (b) hearing aid microphone placed on the opposite side to the stimulated ear (contralateral routing of signals). It was found that the localization performances of all the subjects, especially when using binaural hearing aids, under homolateral routing of signals, were far superior to their respective localization performances achieved with contralateral routing of signals.


The effects of middle ear muscle contraction on auditory and overload thresholds. The present investigation examined psychophysically the frequency-specific and nonlinear attenuation of sound energy provided by middle ear muscle contraction in normal hearers. Aural overload and absolute auditory thresholds were measured at 500, 1 000 and 2 000 Hz prior to and during acoustic stapedial reflex contraction. Reflex contraction was elicited with contralateral broad-band noise. Results revealed that overload thresholds were elevated at 500 and 1 000 Hz and a slight decrease in overload threshold was apparent at 2 000 Hz during reflex contraction while absolute thresholds remained essentially unchanged. These data are consistent with previous psychophysical and physiological findings. The aural overload test having been derived directly from observations of cochlear microphonic saturation, moreover, affords direct comparison to results of electrophysiological experimentation.


An effect of linguistic experience. Auditory word discrimination by native and non-native speakers of English. In this study, the effect of linguistic experience on the auditory discrimination of words has been examined. 18 subjects, including 6 native and 12 non-native speakers of English, were tested with CID auditory test W-22 in quiet and in the presence of white noise at the signal-to-noise (S/N) ratios of +12, +6 and 0 dB. The non-native speakers of English included 6 with 1 year of experience and 6 with 3-4 years of experience speaking Enligsh in the USA. In the absence of noise, the results were essentially equivalent for all three groups. As noise level increased, word discrimination deteriorated for all three groups with non-native speakers of English obtaining results significantly poorer than native speakers of English. Linguistic experience and noise levels were significant at the 0.001 level fo confidence. It appears that at 0 dB S/N, individual variability of non-native speakers of English, regardless of their original linguistic background, was much smaller than that found for native speakers of English. The results of the study tend to indicate that a limited linguistic experience results in a persistent deterioration of auditory word discrimination under impoverished conditions of audition.


Pregnancy rates and non-return rates following artificial and natural breeding in dairy herds. Information routinely supplied during the conduct of a dairy herd health program was analysed to evaluate the performance of artificial breeding in Victoria. A comparison was made between 60 to 90-day non-return rates (supplied by artificial breeding centres) and pregnancy rates (determined by manual pregnancy diagnosis) for first artificial inseminations in 108 herd years in which both items were available in the 1973 and 1974 breeding seasons. The values were 69.3% and 58.2% respectively (P less than 0.001). Non-return rates and conception rates were found to decline as herd size increased. Pregnancy rates to first artificial and natural services did not differ significantly from each other but pregnancy rates were significantly more variable to natural than artificial service (P less than 0.001). The mean pregnancy rate to artificial insemination for all herd years studied was 57.5% and the pregnancy rate to natural service was 58.0%.


Some effects of reduced energy intake on the development of anaplasmosis in Bos indicus cross steers. Some effects of the plane of nutrition on the development of anaplasmosis in Brahman cross steers were investigated. Batches of 39 and 30 Brahman cross steers, aged approximately 27 months were each divided by stratified randomisation into 4 groups of similar mean PCV and body weight. Two similar experiments, designated A and B were conducted. Groups 1 and 2 were fed a ration of lucerne chaff at the rate of 1 M Cal ME/80 kg live weight/day for 8 weeks aimed to reduce body weight by approximately 5 kg/week. Animals in groups 3 and 4 were fed a ration for the same period aimed to increase body weight by approximately 2 kg/week. Groups 1 and 3 were then inoculated with approximately 10(10) Anaplasma marginale infected erythrocytes and the effects of the subsequent infections during the clinical and recovery phases were examined by measuring humoral antibody response, packed cell volume, parasitaemia and body weight. Groups 2 and 4 were uninfected controls. Anaplasmosis, as measured by three responses, was less severe in the starved animals of group 1. Significant differences in packed cell volume and parasitaemia were detected for short periods between the infected groups 1 and 3. Anaplasmosis caused losses of 6.2% and 5.9% in the mean body weight of group 3 animals in experiments A and B respectively. Most of this loss occurred during the clinical phase of the disease. The disease caused no apparent loss of weight in the infected animals of group 1.


Serological procedures to determine time of infection of pigs with porcine parvovirus. It was found possible to correlate serological responses to porcine parvovirus (PPV) with the time after infection. Two procedures were used for PPV antibody measurement: an immunodiffusion technique to measure precipitating antibody and a haemagglutination inhibition (HI) procedure to measure concentration of 2-mercaptoethanol (2-ME) sensitive antibody. Both procedures successfully related antibody titres to time post-infection, but it was considered that a 2 M 2-ME HI procedure showed the greater promise for field investigations.


Adrenocortical insufficiency in the dog. Primary adrenocortical insufficiency is described in 3 dogs. Clinical signs included marked depression, vomiting, diarrhoea, weakness and bradycardia. Diagnosis was based on clinical signs and biochemical findings of hyperkalaemia, hyponatraemia and a lowered plasma Na+ : K+ ratio. Treatment during the acute illness consisted of intravenous fluids and hydrocortisone sodium succinate. Fludrocortisone acetate has maintained all dogs in good health. One dog was on treatment for 4 years.


Squamous cell carcinoma of the tongue of the cat. A case of squamous cell carcinoma of the tongue in an 11-year-old castrated male cat is described. The clinical signs of excessive salivation and inability to eat or drink were associated with enlargement of the tongue. The pathology, possible aetiology and pathogenesis of the neoplasm are discussed.


Guttural pouch mycosis in two horses.

Guttural pouch mycosis in two horses. The history and clinical findings of 1 horses with guttural pouch mycosis referred to us are described. The salient features of the history and clinical signs common to both cases were profuse spontaneous nasal haemorrhage, partial pharyngeal paralysis; subsequently bilateral nasal discharge containing food material, inability to drink and parotid pain became evident. One case made a gradual recovery with conservative medical treatment while the second case was destroyed and submitted for post-mortem, histopathological and microbiological examination. This examination failed to establish the initiating cause of the lesion but later stages were clearly associated with an invasive septate fungus morphologically resembling Aspergillus.


Chronic copper poisoning in dairy cows.

Chronic copper poisoning in dairy cows. Chronic copper poisoning in a dairy herd fed supplementary copper is recorded. Most cows received 11 g of copper sulphate per day but high milk producers received 22.0 g and within 6 months, 3 of them became ill and died. The signs shown by the 3 cows were anorexia, decreased milk production, frequent recumbency and jaundice. Within 4 days of showing signs, the cows died. The autopsy findings were dehydration, anaemia, jaundice, liver damage and intestinal haemorrhage. Liver copper values varied from 1,250 to 2,410 ppm DM.


Chronic methylmercurialism in the cat.

Chronic methylmercurialism in the cat. The mercury levels in 69 muscle samples from fish weighing from 0.3 to 200 kg caught in Moreton Bay, Queensland, in the latter half of 1976 ranged from less than 10 to 2,030 ng/g. Mercury levels in blood samples from 53 humans and 100 dogs in Brisbane almost all contained less than 10 ng/ml while the level in 162 cats sampled ranged from less than 10 to 329 ng/ml. Chronic methylmercurialism developed in 2 cats dosed daily with methylmercury, bound to cysteine, at the rate of 0.6 mg/kg body weight for 74 and 77 days respectively. Terminal clinical signs included anorexia, weight loss, knuckling over at the carpus and tarsus, hypermetria initially involving the forelegs and later the hindlegs, sluggish reflexes, paresis involving all limbs, persistent crying, apparent blindness, tonic and clonic convulsions and salivation. Pathological changes were confined to the nervous system and included degeneration of neurones and perivascular cuffing in the cerebrocortical grey matter, focal atrophy of the granular layer, focal spongiosus of the molecular layer and degeneration and loss of Purkinje cells in the cerebellum and demyelination in the fibre tracts of the dorsal funiculus, mainly the fasciculus cuneatus and in the lateral and ventral corticospinal tracts. Terminal blood methylmercury levels were in excess of 18 microgram/ml, while brain methylmercury levels ranged from 21.0 to 28.4 microgram/g. The liver and kidney contained the highest total levels of mercury of 50 to 80 microgram/g, of which 23 to 37% was inorganic.


A phonocardiographic study of equine heart sounds. The occurrence and timing of heart sounds were examined from phonocardiograms taken from the mitral, aortic and tricupsid recording areas in each of 18 horses. 10 sound events could be identified with each cardiac cycle. Atrial contraction produced up to 3 sound events. The first heart sound consisted of 4 components whereas the second sound was single. Two sound events were associated with the 3rd heart sound in early diastole. The occurrence of third and fourth heart sound components varied between horses and between recording areas. The mitral recording area was considered most satisfactory for routine phonocardiographic studies in horses.


Congenital bovine epizootic arthrogryposis and hydranencephaly. Epizootics of congenital neurological defects in calves have been recorded at various intervals in south eastern New South Wales for over 40 years. In 1974 a particularly severe outbreak occurred. Field observations of the clinical entities, their time of appearance, distribution and incidence were recorded in an attempt to determine an epidemiological pattern. The neurological entities observed occupied different time spans in the epizootic, the order of appearance being polioencephalomyelitis, arthrogryposis, hydranencephaly and micrencephaly. The probable period of infection correlated well with the likely presence of Culiciodes brevitarsus in the epizootic area and the distribution and incidence of neurologic cases likewise correlated well with the expected geographical and climatic distribution of C. brevitarsus in this period. The probable association of Akabane virus infection and the outbreak of stillbirths and abortions which preceded the neurologic entities is discussed.


The isolation of lentogenic strains of Newcastle disease virus in Australia. Twelve isolations of Newcastle disease virus were made from 77 clinical samples from chickens from conjunctivitis, respiratory disease, proventriculitis and bursal atrophy. Nine of the isolations were made from chickens with conjunctivitis. The viruses were identified as Newcastle disease virus by inhibition of their haemagglutinins with specific antiserum to Newcastle disease virus. The viruses failed to kill chicken embryos after inoculation into the allantoic cavity and they were judged to be lentogenic strains. There was no evidence that the Newcastle disease viruses were responsible for any of the clinical conditions from which they were isolated. The presence of other agents in 10 of the samples was indicated by reduced production of haemagglutinin in allantoic fluids of infected embryos, by deaths of infected embryos, by the production of cytopathic changes in avian cell cultures and by electron microscopy. Three isolations of infectious bronchitis virus, 2 of avian adenovirus and one of avian reovirus were made. Other samples were suspected of containing infectious bronchitis virus and mycoplasmas, but these were not isolated. The Newcastle disease viruses failed to produce plaques in chicken embryo fibroblast cell cultures and they were separated from the contaminating agents by haemagglutination and elution followed by passage at terminal dilution in chick embryos. No Newcastle disease virus was isolated from 60 caecal tonsils and 60 lung samples from 9-week-old broiler chickens. Eight lung samples yielded mycoplasmas that caused haemadsorption in chicken cell cultures. The mycoplasmas were probably Mycoplasma gallisepticum.


The toxicity and efficiency of arecoline hydrobromide in the Tasmanian hydatid control program. Results on the efficiency and toxicity of arecoline hydrobromide during the first 11 years of the hydatid limitation program in Tasmania are presented. A satisfactory mucous purge was obtained from about 80% of dogs when arecoline was used at 3.25 mg/kg and from about 75% when the dose rate was reduced to 1.62 mg/kg of body weight. Arecoline is considered to have a low efficiency in detecting tapeworm infection in individual dogs, but is valuable as a diagnostic aid in groups of dogs. Toxicity was seen as acute cardiac collapse in about 5 dogs per 1000 dosed. Deaths followed in 1 dog in about 9,500.


Splenectomy in the horse.

Splenectomy in the horse. Splenectomy was successfully performed on 2 aged horses to facilitate experimental studies of Babesia equi infection. Resection of part of the 17th rib provided the most acceptable approach and avoided many complications encountered on removing part of the 16th rib.


Endrin toxicity in cagebirds.

Endrin toxicity in cagebirds. The deaths of approximately 320 cagebirds (finches, doves, quails) were found to be due to ingestion of panicum seed (Panicum miliaceum) contaminated with endrin. Most birds were found dead but some showed flight instability prior to death. No gross or microscopic lesions were found in necropsied birds.


A health program for commercial dairy herds. 1. Objectives and methods. A health program for dairy herds is defined as a planned and coordinated approach to achieving and maintaining optimal health and productive efficiency of livestock. A program is described, which has been developed over a period of eight years to fulfill this definition in providing veterinary services to commercial dairy herds. It is demonstrated that clinical veterinary services to participating herds did not satisfactorily achieve the stated aim and therefore an alternative approach was developed. This approach is centred around the concept of performance targets, and each herd is monitored closely by means of a computer-based health and productivity monitoring system in order to detect deviation from target performance. When such deviations occur, the monitoring system is used to diagnose the nature of the problem. The detailed targets adopted in this study are described and the examinations which are undertaken on cattle are outlined. These examinations are aimed at correcting problems, or at confirming satisfactory performance. Further details of the findings of the study are outlined in following papers.


A health program for commercial dairy herds. 2. Data processing. The development of a computerised data handling and analysis system to aid the operation of a health and management program for commercial dairy herds is described. The aims for the system are outlined, and the development of the system over a period of 8 years to meet these aims is described. The documentation used in the current system is described in relation to the various procedures involved in the operation of the dairy herd health program. Two features which make this system unique are its use for the selection of problem and high risk cows for examination and treatment, and the provision of analyses of recent performance in a number of facets of health and production, which aid in the identification of emerging problems. It is considered that future improvements in the system will be in the areas of milk production recording and calf rearing and disease recording.


A health program for commercial dairy herds. 3. Changes in reproductive performance. A health program service was implemented on 9 farms, for periods ranging up to 7 years. Reproductive performance was substantially improved, when performance indicators were compared with values for the herds prior to commencement of the service. On average, the mean calving to conception intervals for the herds were reduced by 24 days over their periods of participation in the program, from an initial value of 119 days. The intercalving interval was reduced by an average of 27 days. This improvement was associated with a reduction in the mean dry period length of 20 days, from an initial value of 117 days. There was a tendency for the lactation lengths to be reduced to an undesirable extent due to slow adaptation by management to the improvement in reproductive performance, but the problem was corrected late in the study. The improvement in performance was attributed to improved oestrus detection, correction of temporary nutritional deficiencies, and prompt treatment of genital tract disorders in individual animals. Results for a range of performance indicators related to reproductive function are reported in detail.


A health program for commercial dairy herds. 4. Changes in mastitis prevalence. A study of mastitis prevalence in 10 herds which participated in a herd health program is reported for varying periods, up to a maximum of 10 years. The program was based on teat dipping with idophor or sodium hypochlorite teat dip, regular maintenance of the milking machine, and selective dry period treatment of quarters which were classified as infected on the basis of California Mastitis Test score and bacteriological examination of milk samples taken before drying off. The procedures reduced mastitis prevalence (measured in cows being dried off), incidence of clinical mastitis, and disposal of cows due to mastitis. Results obtained were similar to those found in short-term studies of control programs based on teat dipping and dry period therapy. The only significant difficulty which arose in maintaining the control program over 10 years was loss of enthusiasm by farmers for teat dipping. This was usually induced by teat irritation problems apparently caused by teat dipping. The use of a monitoring procedure for mastitis prevalence was important in persuading farmers to return to the use of teat dip.


A health program for commercial dairy herds. 5. The occurrence of specific disease entities. Disease incidence data was collected from 9 dairy herds which participated in a herd health program. A total of 11,534 cow years was analysed. In common with other Australian data, the important clinical diseases were mastitis and infertility. There was an average level of 43.4 disease incidents per year per 100 animals at risk. An average of 18.6% of the herd left each year. This comprised 1.5% through death and 17.1% through sale. Disease accounted for the disposal of 9.8% of animals, and management reasons for 8.8%. These findings are similar to those of other studies in Australia and in other countries, but the results in this study were based on a longer period and on closer surveillance.


Urolithiasis in animals.

Urolithiasis in animals. Urolithiasis is a disease of multifactorial origin. Prominent amongst the causes of disease outbreaks are nutritional factors. Alteration of diet is probably one of the most effective means of prevention, depending of course on the nature of the uroliths formed. In this regard analysis of the stones formed is an essential prelude to understanding, adequately treating the disease and preventing its recurrence.


Osteochondritis dissecans in the dog.

Osteochondritis dissecans in the dog. The diagnosis, aetiology, pathogenesis and treatment of osteochondritis dissecans in the shoulder, elbow, stifle and hock joints of the dog is reviewed. A technique of surgically exploring the shoulder joint with minimal exposure is described. Recommendations for preventing the development of osteochondritis dissecans are made.


Pathogenicity for cattle of atypical mycobacteria isolated from feral pigs and cattle and the correlation of lesions with tuberculin sensitivity. Two experiments involving the inoculation of cattle with atypical mycobacteria are described. In the first experiment groups of 5 cattle were inoculated either subcutaneously or into a mesenteric lymph node with a strain of M. scrofulaceum or M. intracellulare. Four weeks and 10 weeks after inoculation the cattle were tuberculin tested with bovine PPD, avian PPD and homologous PPDs. The pathological changes observed were similar within each group of cattle inoculated with the same strain of mycobacteria. A significant interaction was demonstrated between the strain and the route of inoculation. In the second experiment 17 cattle were similarly inoculated by either of the two routes with 1 of 6 strains of M. intracellulare, a strain of M. scrofulaceum or a strain of Runyon Group IV, all of which had been isolated from feral pigs, or a strain of M. intracellulare of bovine origin. Tuberculin tests were carried out after 4 weeks and 10 weeks. Only the isolate from a bovine lymph node produced a significant level of sensitivity to bovine PPD. Cultural isolation of the mycobacteria from autopsy material was not correlated with the presence of macroscopic lesions nor with sensitivity to bovine PPD. The response to bovine PPD of cattle infected with these atypical mycobacteria decreased between 48 h and 96 h after injection of the tuberculins. As the maximum difference in the response to bovine and avian tuberculins occurs at 72 h a comparative tuberculin test should be read at this time to eliminate non-specific reactors.


The toxicity of myoporum tetrandrum (Boobialla) and myoporaceous furanoid essential oils for ruminants. Boobialla (Myoporum tetrandrum)leaf contains from 0.25 to 0.5% wet weight of furanoid sesquiterpene essential oils of which the main component is dehydrongaione. The plant was toxic when dosed to calves at equivalent dose rates of oils of from 50 to 134 mg/kg, causing mainly extensive haemorrhagic centrillobular necrosis; and to sheep at equivalent dose rates of oil of from 55 to 66 mg/kg, causing either centrilobular or periportal liver lesions with or without acute pulmonary oedema. An essential oil mixture of similar composition derived from Myoporum deserti produced similar syndromes. In addition, treatment of calves with phenobarbitone or Melaleuca linariifolia essential oils prior to dosing with the Myoporum oils caused periportal hepatic necrosis rather than the centrilobular lesion which occurred usually in this species. The liver lesions found in the experimental calves and sheep respectively, were thus similar to those reported in suspected field cases of Boobialla poisoning in cattle and goats in Western Australia. The liver injury that may be expected in intoxication of livestock by myoporaceous plants containing this type of essential oils can thus be either periportal, midzonal or centrilobular necrosis, depending, probably, on the nutritional regime of the animal immediately prior to consumption of the toxic plant.


The prevalence and distribution of leptospiral titres in cattle and pigs in Queensland. Serological test results for leptospiral species on serums from cattle and pigs performed by the diagnostic laboratories of the Queensland Department of Primary Industries from July 1973 to June 1976 were used to determine the prevalence and geographical distribution of 3 leptospiral serotypes in Queensland. There was a higher prevalence of antibodies to L. hardjo than to L. pomona in cattle, whereas in pigs the prevalence of antibodies to L. pomona was much higher than that for L. tarassovi or L. hardjo. Feral pigs had a particularly high prevalence of L. pomona antibodies. There is a different geographical distribution of antibodies to L. pomona and L. hardjo. L. hardjo antibodies appear to be fairly uniformly distributed but there is a higher prevalence of L. pomona antibodies in low rainfall areas. This relationship was shown to be significantly correlated.


The effect of age on resistance of cattle to Babesia bovis. Susceptible Hereford cattle of different ages were inoculated with 2 X 10(8) Babesia bovis organisms. Experiment I consisted of cows aged 6 to 7 years, steers aged 17 to 18 months and calves aged 5 to 6 months, while experiment 2 consisted of cows aged 6.5 to 7.5 years, steers aged 23 to 24 months and yearlings aged 11 to 12 months. Daily measurements of temperature, parasitaemia and packed cell volume were made in order to determine susceptibility of the different ages. Twenty-four of the 36 animals in experiment I, which included all 12 cows, required treatment. One cow died as a result of an enlarged ruptured spleen, and 2 steers and 1 calf died with classical babesiosis symptoms. No treatement was given to experiment II animals, and 5 of the 12 cows died, but the steers and yearlings underwent relatively mild reactions. Statistical analysis confirmed the high susceptibility to B. bovis of the aged cows in both experiments, and the innate resistance of 5 to 6 month old calves in experiment I. The reaction of the 18-month-old steers in experiment I was significantly greater than that of the calves, but significantly less severe than that of the aged cows. Two-year-old steers and yearlings in experiment 2 underwent similar mild reactions, suggesting that innate immunity may persist for longer periods when compared to aged cows. Age groups showing reduced susceptibility were found to reach peak parasitaemia, temperature and anaemia before the more susceptible age groups. Heterologous challenge of the remaining experiment 1 and experiment 2 animals at 6 and 8 months respectively after primary inoculation, revealed all animals of all ages had a solid resistance to B. bovis.


Melioidosis in a sulphur-crested cockatoo (Cacatua galerita). A case of melioidosis in a sulphur-crested cockatoo (Cacatua galerita) kept as a pet in Townsville is described. This case was characterised by liver necrosis with both a heterophil and mononuclear cell inflammatory response associated with giant cells. Pseudomonas pseudomallei was isolated by blood plate culture and guinea pig inoculation. This is the first case of melioidosis reported in a native bird in Australia.


Toadfish poisoning (tetrodotoxin) in the cat. Two cases of tetrodotoxin (toadfish) poisoning in the cat are reported. The pharmacological and physiological actions of the toxin and treatment of this intoxication are discussed.


The specificity of prostaglandin E2 (PGE2) in reducing coronary vascular resistance: A comparison with adenosine. Experiments were performed on the isolated, electrically driven guinea-pig heart, perfused at constant rate. All animals were pretreated with reserpine. Myocardial contractile force (MCF), coronary perfusion pressure (CPP) and myocardial oxygen consumption (QO2) were monitored continuously. Both adenosine (ADO) and PGE2 produced a concentration-dependent decrease in the CPP. The ED50 (50% of maximum response) was 2.1 +/- 0.6 X 10(-9)M for PGE2 but 40 +/- 7 X 10(-9)M for ADO (P less than 0.01) at 1.8 mM Ca(e). This coronary vasodilation was independent of the external Ca-concentration, which was varied between 0.55-9.0 mM. PGE2 had no effect on MCF or QO2 and the effect of ADO was only slight. There was no evidence that any action of ADO could be inhibited by simultaneously applied PGE2. The results provide evidence for the specific coronary vasodilating action of PGE2 which in this system is about 20 times as effective as adenosine.


Multifactorial determination of 201thallium uptake of the heart: an experimental study concerning the influence of ventricular mass, perfusion and oxygen consumption. Studies were performed in 42 cats in order to analyze the determinants of myocardial 201Thallium uptake. (1) Ventricular mass represents the major determinant of myocardial 201Thallium uptake. The inner (subendocardial) layer of the left ventricle storages 10-15 per cent more Thallium than the outer (subepicardial) layer, whereas the right ventricle has 201Thallium accumulation by 40 per cent less than the left ventricle. (2) Coronary perfusion increase as induced by intravenous injection of dipyridamole leads-at constant muscle mass-to considerable increase in myocardial 201Thallium uptake by 106 per cent. (3) Changes in myocardial oxygen consumption as induced by inotropic interventions are associated with considerable changes in the myocardial 201Thallium uptake. These results demonstrate that ventricular mass, myocardial flow and myocardial oxygen consumption are major determinants of myocardial 201Thallium uptake. Thus, by quantitiative determination of the myocardial 201Thallium uptake, a useful equivalent of the viability degree of the left ventricle, which itself is determined by mass, flow and metabolism, may be obtained.


PO2 and microflow histograms of the beating heart in response to changes in arterial pO2. The influence of different values of arterial oxygen partial pressure (PO2) on local tissue PO2 was investigated. Tissue PO2 was measured on the surface of the beating hearts of rabbit and cat by the multiwire surface electrode as described by Kessler and Lübbers (21). In parallel experiments, local hydrogen clearance applying the H2-PH2 probe (33) was used to determine the mean blood flow per area (microflow) at the capillary level. Mean blood flow per area, v, was calculated from PH2 clearance curves obtained by local application of rectangular hydrogen pulses. The results are presented as histograms. Under steady state conditions (barbiturate narcosis), tissue PO2 ranged from 5 to 65 Torr (0.67 to 8.67 kPA) with a median of 31 Torr (4.13 kPA) in the cat heart. Mean flow per area covered values between 25 and 11 mum/s with a median of 55 mum/s. For rabbit heart muscle, the median was v = 37 mum/s and the range 28 to 46 mum/s. Hyperoxia broadened the range of tissue PO2 and shifted flow per area to lower values. Different degrees of hypoxia shifted the PO2 histogram to the left (median PO2 14 Torr and 4 Torr, respectively; [1.87 kPA and 0.53 kPA]) and the flow histogram to the right.


[Systolic time intervals. 1st communication: normal values from children without heart diseases]. The concept of "systolic time intervals" was introduced into noninvasive cardiologic examination by Weissler et al.; in detail these are the following data: the total electromechanical systole = QS2, the left ventricular ejection time = LVET, the preejection period = PEP and the quotient PEP/LVET. These quantities are not in principle new parameters; in the German literature the QS2 is known as "Systolendauer", the LVET is identical to the "Austreibungszeit" and the PEP is identical to the "Anspannungszeit". The determination of PEP (= QS2-LVET) is preferable to the usual calculation of the "Anspannungszeit" nach Blumberger in so far as longer time intervals must be measured and therefore the statistical error decreases. From 96 children between 3 and 15 years polygraphic tracings were recorded and the STI were calculated and standard values were ascertained and were evaluated statistically. QS2 and LVET grow longer linearly with increasing age (p less than or equal to 0.001) and diminish linearly with increasing heart rate (p less than or equal to 0.001). For PEP only the inverse correlation with the heart rate was significant. PEP/LVET does not very significantly. Girls have longer PEP (+ 6 msec, p less than or equal to 0.01) and higher PEP/LVET (+ 0.04, p less than or equal to 0.001) than boys. The normal range of variation of the STI is relatively large (QS2: 278-386 msec, LVET: 200-285 MSEC, PEP: 65-114 msec, PEP/LVET: 0.27-0.47). For the examination of individual cases it is better to compare them with the standard values ascertained by the regression equations (table 3+4).


Studies on sex-organ development. Changes in chemical composition and oestradiol-binding capacity in chromatin during the differentiation of chick Müllerian ducts. Biochemical and immunochemical techniques were used to probe the changes in composition of the chromatin of differentiating Müllerian ducts. The non-histone protein increases gradually in the left duct and reaches a constant amount at day 15 of incubation, then remains at the same value until after birth. In the regressing right duct, the non-histone protein increases and then decreases. Gel electrophoresis indicated an increased heterogeneity in the composition of the non-histone protein corresponding to Müllerian-duct differentiation. Little variation in quantity and quality of the histone was observed; however, immunochemical assay confirmed the structural change of Müllerian-duct chromatin during development. An antibody against the chromatin of the newborn-chick oviduct was produced in the rabbit. The chromatin of Müllerian ducts from the early embryonic stage showed a small affinity with the antibody; the affinity increased during the late embryonic stages. The affinity was greatly decreased in the regressing right duct. Oestrogen-binding sites were present in the chromatin of the left and right Müllerian ducts during differentiation, with more sites in the left duct than in the right one during the late stages of development. After oestrogen treatment in vivo, the oestrogen-binding sites on the chromatin of both the left and the right ducts were increased, with a greater increase in the left duct than in the right. In the developing left duct the binding sites reach a maximum on day 15 of incubation, and remain constant at that value until birth.


The realiability of rates of glucose appearance in vivo calculated from constant tracer infusions. The rate of appearance of unlabelled glucose was calculated from tracer data and compared with the actual rate of infusion of unlabelled glucose into a anaesthetized dog with all sources  of endogenous glucose production surgically removed. The mean steady-state rate of appearance of unlabelled glucose calculated from the equilibrium specific radioactivity was insignificantly higher (0.3%) than the actual rate of infusion of unlabelled glucose (n = 6). During non-steady states, a time-variable volume of distribution of glucose (V) was necessary to predict the rate of appearance of unlabelled glucose correctly from the pool-dependent equation described by Steele [(1959) Ann. N.Y. Acad. Sci. 82, 420--430]. Rapid fluctuations in the rate of appearance of glucose could be predicted reasonably well by using a fixed value of V for 40ml/kg, but by using larger fixed values for V (100--160ml/kg) the rates were inaccurate. The pool-dependent two-radiactive-isotope technique described by Issekutz, Issekutz & Elahi [(1974) Can. J. Physiol. Pharmacol. 52, 215--224] predicted single-step increases in the rate of infusion of glucose reasonably accurately, but the Steele (1959) equation was better at predicting sequential changes in the rate of infusion of unlabelled glucose.


Protein phosphorylation in normal and neoplastic development. Phosphorylation of proteins endogenous to foetal tissues and tumours. The abilities of proteins endogenous to normal and neoplastic tissues to serve as substrates in a protein-phosphorylation reaction in vitro were compared. After the tissue extracts were incubated with [gamma-32P]ATP, the phosphorylated proteins were separated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and the dried gels were subjected to radioautography. Considerable incorporation of 32P into a protein of mol.wt. 135000 was observed with extracts from foetal tissues and tumours, but only minimal incorporation into this protein occurred when extracts from adult tissues were used. The ability of this protein to become phosphorylated in vitro may be related to cell proliferation. When ascites cells were incubated with [32P]Pi, one of the major phosphoproteins migrated on sodium dodecyl suphate/polyacrylamide gels at mol.wt. 135000, suggesting that this protein can be phosphorylated both in intact cells and broken-cell preparations. A protein of mol.wt. 87000 was highly phosphorylatable in extracts from solid tumours, but was not phosphorylated in extracts from ascites tumours, foetal or adult tissues. The phosphorylation pattern of these two proteins can thus distinguish solid neoplasms and normal adult tissues from ascites tumours and from foetal tissues. A protein of mol.wt. 49000, which was the most labelled protein in adult tissues, was also one of the major phosphoproteins in foetal and neoplastic tissues. Numerous mechanisms are postulated to explain how the extent of 32P incorporation into a protein could vary as a function of biological state.


Composition and distribution of glycosaminoglycans in cultures of human normal and malignant glial cells. The glycosaminoglycans of human cultured normal glial and malignant glioma cells were studied. [35S]Sulphate or [3H]glucosamine added to the culture medium was incorporated into glycosaminoglycans; labelled glycosaminoglycans were isolated by DEAE-cellulose chromatography or gel chromatography. A simple procedure was developed for measurement of individual sulphated glycosaminoglycans in cell-culture fluids. In normal cultures the glycosaminoglycans of the pericellular pool (trypsin-susceptible material), the membrane fraction (trypsin-susceptible material of EDTA-detached cells) and the substrate-attached material consisted mainly of heparan sulphate. The intra- and extra-cellular pools showed a predominance of dermatan sulphate. The net production of hyaluronic acid was low. The accumulation of 35S-labelled glycosaminoglycans in the extracellular pool was essentially linear with time up to 72h. The malignant glioma cells differed in most aspects tested. The total production of glycosaminoglycans was much greater owing to a high production of hyaluronic acid and hyaluronic acid was the major cell-surface-associated glycosaminoglycan in these cultures. Among the sulphated glycosaminoglycans chondroitin sulphate, rather than heparan sulphate, was the predominant species of the pericellular pool. This was also true for the membrane fraction and substrate-attached material. Furthermore, the accumulation of extracellular 35S-labelled glycosaminoglycans was initially delayed for several hours and did not become linear with time until after 24 h of incubation. The glioma cells produced little dermatan sulphate and the dermatan sulphate chains differed from those of normal cultures with respect to the distribution of iduronic acid residues. The observed differences between normal glial and malignant glioma cells were not dependent on cell density; rather they were due to the malignant transformation itself.


The influence of ammonia on purine and pyrimidine nucleotide biosynthesis in rat liver and brain in vitro. 1. The effect of ammonia on purine and pyrimidine nucleotide biosynthesis was studied in rat liver and brain in vitro. The incorporation of NaH(14)CO(3) into acid-soluble uridine nucleotide (UMP) in liver homogenates and minces was increased 2.5-4-fold on incubation with 10mm-NH(4)Cl plus N-acetyl-l-glutamate, but not with either compound alone. 2. The incorporation of NaH(14)CO(3) into orotic acid was increased 3-4-fold in liver homogenate with NH(4)Cl plus acetylglutamate. 3. The 5-phosphoribosyl 1-pyrophosphate content of liver homogenate was decreased by 50% after incubation for 10min with 10mm-NH(4)Cl plus acetylglutamate. 4. Concomitant with this decrease in free phosphoribosyl pyrophosphate was a 40-50% decrease in the rates of purine nucleotide synthesis, both de novo and from the preformed base. 5. Subcellular fractionation of liver indicated that the effects of NH(4)Cl plus acetylglutamate on pyrimidine and purine biosynthesis required a mitochondrial fraction. This effect of NH(4)Cl plus acetylglutamate could be duplicated in a mitochondria-free liver fraction with carbamoyl phosphate. 6. A similar series of experiments carried out with rat brain demonstrated a significant, though considerably smaller, effect on UMP synthesis de novo and purine base reutilization. 7. These data indicate that excessive amounts of ammonia may interfere with purine nucleotide biosynthesis by stimulating production of carbamoyl phosphate through the mitochondrial synthetase, with the excess carbamoyl phosphate in turn increasing pyrimidine nucleotide synthesis de novo and diminishing the phosphoribosyl pyrophosphate available for purine biosynthesis.


Tryptophan pyrrolase, the regulatory free haem and hepatic porphyrias. Early depletion of haem by clinical and experimental exacerbators of porphyria. 1. The importance of the early depletion of liver haem in the production of porphyria is discussed and further supporting evidence is presented from experiments with tryptophan pyrrolase, under conditions of exacerbation of experimental porphyria by therapeutic and other agents. 2. In addition to the early depletion of pyrrolase haem by porphyrogens, a further depletion is produced when rats are given a porphyrogen plus an analogue or one of 19 drugs known to exacerbate the human disease. 3. Non-exacerbators of human porphyrias do not cause a further early depletion of pyrrolase haem and it is suggested that this system may be used as a screening test for possible exacerbation of the disease by new and existing drugs. 4. A similar further early depletion of haem is produced by combined administration of lead acetate plus phenobarbitone, thus suggesting that the depletion is a more general phenomenon in experimental porphyria. 5. The relationship between tryptophan pyrrolase and the regulatory free haem is discussed. It is suggested that pyrrolase may play an important role in the regulation of haem biosynthesis.


Distinctive effects of glucagon on gluconeogenesis and ketogenesis in hepatocytes isolated from normal and biotin-deficient rats. In hepatocytes from 48 h-starved rats identical glucagon dose-response curves were obtained for the stimulation of gluconeogenesis from lactate, for ketogenesis and for the decreasing of the C5-dicarboxylate pool. Glucagon (20 nM) caused a 5-fold increase in 3-hydroxybutyrate formation, but decreased acetoacetate production 50% of that of the control. In hepatocytes from biotin-deficient rats glucagon no longer stimulated gluconeogenesis from lactate, but still produced its effects on the mitochondrial redox state and the C5-dicarboxylate pool. The results suggest that the primary site of the hormone action on gluconeogenesis is located within the mitochondria rather than in the cytosol.


Increased calcium-ion influx is a component of capacitation of spermatozoa. Capacitation (modifications required for gamete fusion) is produced by incubating guinea-pig spermatozoa in vitro in a chemically defined medium. It is shown that during such incubation a net uptake of Ca2+ by the sperm occurs in two distinguishable phases. An initial loose association of Ca2+, possibly to surface sites, is unaffected by agents (Mg2+, inhibitors of mitochondiral function) that prevent or delay the exocytotic spermatozoal acrosome reaction. The time course of a secondary Ca2+ uptake parallels or slightly precedes the time course of the acrosome reaction. This parallelism is maintained during a variety of treatments that either expedite (local anaesthetics, ionophore A23187, Triton X-100) or delay (Mg2+, low external Ca2+) the acrosome reaction. We conclude that the secondary Ca2+ influx described herein apparently serves to link alterations of the spermatozoal membrane to subsequent contractile and secretory components of the capacitation sequence.


Phycocyanobilin synthesis in the unicellular rhodophyte Cyanidium caldarium. Light is required for synthesis of the accessory photosynethetic pigment phycocyanin in cells of the unicellular rhodophyte Cyanidium caldarium. Phycocyanin is a conjugated protein composed of polypeptide subunits to which the light-absorbing bile pigment chromophore phycocyanobilin is covalently attached. Dark-grown cells of C. caldarium are unable to make phycocyanin, but when incubated in the dark with 5-aminolaevulinate the cells synthesize and excrete a protein-free phycobilin (algal bile pigment) into the suspending medium. The electronic absorption spectrum, electron impact mass spectrum, chromatographic properties and imide products obtained after chronic acid degradation of the excreted phycobilin were identical with those of phycocyanobilin cleaved from phycocyanin in boiling methanol. This establishes the structural identity between the excreted phycobilin, which is the end product of bile-pigment synthesis in vivo, and the chromophore cleaved from phycocyanin in boiling methanol. The significance of the structure of the excreted phycobilin with respect to the events surrounding the assembly of the phycocyanin molecule in vivo is discussed.


Characterization of uterine heterogeneous nuclear ribonucleic acid and the effect of oestradiol-17 beta on its synthesis. An early response to the administration of oestradiol-17 beta to immature rats is a dramatic stimulation in the synthesis of uterine hnRNA (heterogenous nuclear RNA). High-molecular-weight fractions of the hnRNA were purified and subfractionated on poly(U)-Sepharose into fractions that differed in their poly(A) content and their size profile on polyacrylamide gels. Oestrogen treatment of the rats stimulated the synthesis of all three fractions of high-molecular-weight hnRNA, but the kinetics of synthesis, degree of stimulation and size distribution of the newly synthesize RNA differed in each fraction.


Effects of ammonia and norvaline on lactate metabolism by hepatocytes from starved rats. The use of 14C-labelled lactate in studies of hepatic gluconeogenesis. 1. Hepatocytes from starved rats were incubated with l-lactate and NH(4)Cl or norvaline, and the rates of the tricarboxylic acid cycle and of gluconeogenesis were calculated from changes in metabolite concentrations or from radioisotopic data from incubations with labelled lactate or propionate. 2. Gluconeogenesis was stimulated by the addition of 10mm-NH(4)Cl, 5mm-norvaline or 1mm-oleate by 27, 45 and 59% respectively. NH(4)Cl or norvaline also increased lactate uptake. Norvaline inhibited urea synthesis from NH(4)Cl by 85%. 3. The effects of NH(4)Cl and norvaline were not additive. However, NH(4)Cl inhibited and norvaline was without effect on gluconeogenesis from pyruvate, indicating that the two compounds act by different mechanisms. 4. The tricarboxylic acid-cycle flux was increased 80% by lactate, and NH(4)Cl caused a further 25% stimulation. Norvaline had no effect on the tricarboxylic acid-cycle flux. NH(4)Cl and norvaline tripled and doubled, respectively, flux through pyruvate dehydrogenase. 5. Total ATP formation was calculated to range from 470 to 830mumol/h per 100mg of protein, of which the basic metabolic activity accounted for 400-450mumol/h per 100mg of protein. ATP formation does not seem to be rate-limiting for gluconeogenesis. 6. Pyruvate recycling was estimated from the (14)C yield from [1-(14)C]propionate in lactate and glucose to be 10-30% of the flux of phosphoenolpyruvate to glucose. The further addition of NH(4)Cl more than doubled the recycling of pyruvate. 7. [1,4-(14)C]Succinate was rapidly metabolized by hepatocytes. About 20% of the radioactivity was recovered in glucose, indicating that succinate is also metabolized by intact (non-damaged) hepatocytes. 8. It is concluded that the metabolism of lactate by the liver is too complex to allow simple rate measurements with labelled compounds.


Some transport properties of resealed washed human erythrocyte membranes. A comparison was made between the phosphate- and glucose-transport systems of intact erythrocytes and resealed washed membranes. Glucose transport exhibits identical properties in both cases, but the phosphate-transport system does not appear to have survived the membrane isolation procedure unaltered. Evidence is presented to support the suggestion that some form of structural perturbation has occurred to the protein mediator of phosphate exchange.


Bifunctional intercalation and sequence specificity in the binding of quinomycin and triostin antibiotics to deoxyribonucleic acid. Quinomycin C, triostin A and triostin C are peptide antibiotics of the quinoxaline family, of which echinomycin (quinomycin A) is also a member. They all remove and reverse the supercoiling of closed circular duplex DNA from bacteriophage PM2 in the fashion characteristic of intercalating drugs, and the unwinding angle at I 0.01 is, in all cases, almost twice that of ethidium. Thus, as with echinomycin, they can be characterized as bifunctional intercalating agents. For the triostins this conclusion has been confirmed by measurements of changes in the viscosity of sonicated rod-like DNA fragments; the helix extension was found to be almost double that expected for a simple monofunctional intercalation process. For triostin A, further evidence for bifunctionality was derived from the cross-over point of binding isotherms to nicked circular and closed circular bacteriophage-PM2DNA. Binding curves for the interaction of quinomycin C and triostin A with a variety of synthetic and naturally occurring nucleic acids were determined by solvent-partition analysis, but triostin C was too insoluble in aqueous solution to make this method applicable. For quinomycin C the highest binding constant was found with Micrococcus lysodeikticus DNA, and its pattern of specificity among natural DNA species was broadly similar to that of echinomycin, although the binding constants were 2--6 times as large. For triostin A the highest binding constant was again found for M. lysodeikticus DNA, but the specificity pattern was quite different from that of the quinomycins. In particular, triostin A bound better to poly(dA-dT) than to the poly(dG-dC) whereas this order was reversed for quinomycin C. There was also evidence that the binding to poly(dA-dT) might be co-operative in nature. No significant interaction could be detected with poly(dA).poly(dT) or with RNA from Escherichia coli. Poly(dG).poly(dC) gave variable results, depending on the source of the polymer. The different patterns of specificity displayed by the quinomycins and triostins are tentatively ascribed to differences in their conformations in solution.


Interaction between synthetic analogues of quinoxaline antibiotics and nucleic acids. Changes in mechanism and specificity related to structural alterations. The interaction with DNA of six chemically synthesized derivatives of the quinoxaline antibiotics was investigated. Five of the compounds bound only weakly to DNA or not at all; for these substances spectrophotometric measurements, sedimentation studies with closed circular duplex bacteriophage-PM2 DNA and thermal-denaturation profiles were used to determine limits fot the binding constants. No interaction could be detected with two products of degradation of echinomycin (quinomycin A), one of which, echinomycinic acid dimethyl ester, had the lactone linkages opened, whereas the other retained an intact octapeptide ring but had a broken cross-bridge. The other compounds studied were des-N-tetramethyl-triostin A ('TANDEM') and its derivatives. A derivative of 'TANDEM' IN WHICH benzyloxycarbonyl moieties replace both quinoxaline chromophores had binding constants to nucelic acids in the range 10(2)--10(3)-1, whereas no interaction could be detected for a benzyloxycarbonyl derivative that, in addition, had the cross-bridge broken. The derivative of 'TANDEM' with L-serine in place of D-serine in both positions showed no detectable interaction with Clostridium perfringens DNA, whereas the binding constant to poly(dA-dT) was approx 2 X 10(3)M-1. 'TANDEM' itself bound strongly to DNA, and the bathochromic and hypochromic shifts in its u.v.-absorption spectrum in the presence of DNA were similar to those seen with echinomycin. From the effect on the sedimentation coefficient of closed circular duplex bacteriophage-PM2 DNA the mechanism of binding was shown to involve bifunctional intercalation, typical of the naturally occurring quinoxaline antibiotics. Solvent-partition analysis was used to determine binding constants for the interaction between 'TANDEM' and a variety of natural and synthetic DNA species. The pattern of specificity thus revealed differed markedly from that previously found with the naturally occurring quinoxaline antibiotics. Most striking was the evident large preference for (A + T)-rich DNA species, in complete contrast with echinomycin and triostin A. The highest binding constant was found for poly(dA-dT), the interaction with which appeared highly co-operative in character. The conformations adopted by those quinoxaline compounds that bind strongly to DNA were examined withe aid of molecular models on the basis of results derived from n.m.r. and computer studies. It appears that the observed patterns of base-sequence specificity are determined, at least in part, by the structure and conformation of the sulphur-containing cross-bridge.


Isolation and characterization of isocitrate lyase from a thermophilic Bacillus sp. Isocitrate lyase was isolated in homogeneous state from a thermophilic Bacillus. The enzyme has a mol.wt. of 180000 and a pI of 4.5 and contains threonine as the N-terminal residue. It resembles in size the cognate enzyme from the mesophilic bacterium Pseudomonas indigofera, but is smaller than the enzyme from the eukaryotic fungus Neurospora crassa. All three lyases are tetramers and similar in amino acid composition, but the thermophile enzyme is distinctive from its mesophilic coutnerparts in possessing a lower catalytic-centre activity, greater resistance to chemical and thermal denaturation and fewer thiol groups and in being strongly activated by salts. Salt activation, by 0.4M-KCl, is about 3-fold at 30 degrees C and pH 6.8 and weakens progressively as the temperature or pH is raised. The activation is probably due to a change in the enzyme conformation caused by the electrolyte modifying the interaction between charged groups or between hydrophobic groups in protein. The possible significance of the salt activation, of the relative paucity of thiol groups and of the greater resistance to chemical denaturants is discussed. Besides its effect on the Vmax., KCl produces large increases in the magnitude of several kinetic parameters. A rise in reaction temperature from 30 to 55 degrees C produces a somewhat similar result. In view of these peculiar features, the patterns of inhibition of enzyme activity by compounds such as succinate and phosphoenolpyruvate were examined at 30 and 55 degrees C in the presence and absence of KCl.


A defined molecular-weight distribution of deoxyribonucleic acid after extensive sonication. Concentrated solutions of low-molecular-weight DNA (Mw=35000) with a known molecular-weight distribution can be prepared in several hours, and require no additional fractionation procedures. This is achieved by sonication of the DNA in 1.0 M-NaCl at high power at 0--2 degrees C. No denaturation of the DNA is detectable, even after 8h of continuous sonication. After 2h, the molecular-weight distribution of the total DNA sample is that of the most probably Schulz distribution, described by-Mn:-Mw:-Mz ...=1:2:3 ...etc. Such a molecular-weight distribution is expected for a random break-up of indefinitely long macromolecules and indicates that the sonication process is essentially by random double-strand scission. DNA was also sonicated in the presence of ligands capable of modifying the DNA tertiary structure. The results support the idea that inflexibility of the DNA is required for efficient sonic degradation.


The similarity of the two high-molecular-weight polypeptides of erythrocyte spectrin. 1. The two major polypeptides (P1 and P2) of erythrocyte-membrane spectrin were isolated by preparative polyacrylamide-gel electrophoresis. 2. The two polypeptides were shown to possess similar amino acid compositions, both with the characteristically high glutamate and leucine contents of the parent spectrin. 3. The tryptic-peptide 'maps' of the two polypeptides were prepared by a combination of t.l.c. and electrophoresis. 4. Radioactive peptides were prepared by [14C]carboxymethylation and chloramine-T-catalysed [125I]iodination. 5. 'Maps' of both sets of peptides demonstrate a marked similarity between the two polypeptides. 6. These new data confirm earlier evidence for the similarity of the two chains. 7. The number of peptides in the 'maps' of carboxymethylated peptides suggest that polypeptides P1 and P2 are not aggregates.


Characterization of proteoglycan and the proteoglycan--hyaluronic acid complex by electric birefringence. An electric field causes partial alignment of macromolecules in a dilute solution. The accompanying changes in the solution birefringence offer a sensitive and quick means of monitoring the rates of particle orientation and hence the size of the solute molecules. Such measurements are reported for dilute solutions of proteoglycans in the absence and presence of added hyaluronic acid. The proteoglycan molecules are shown to be some 580 nm long. In the presence of hyaluronic acid they form aggregates that appear to be consistent with the model previously proposed in which the proteoglycans attach radially to the extended hyaluronic acid chain. The electric-birefringence relaxation rates indicate aggregates of similar length to that of the extended hyaluronic acid chain, with the proteoglycans spaced on average at 29nm intervals. A proteoglycan sample the cystine residues of which had been reduced and alkylated showed no evidence of aggregation with hyaluronic acid up to the concentrations of the acid corresponding to 1% of the total uronic acid content. The electric-birefringence method is shown to have a large potential in the study of associating polysaccharide solutions.


Blood-group-Ii-active gangliosides of human erythrocyte membranes. More than ten new types of gangliosides, in addition to haematoside and sialosylparagloboside, were isolated from human erythrocyte membranes. These were separated by successive chromatographies on DEAE-Sephadex, on porous silica-gel columns and on thin-layer silica gel as acetylated compounds. Highly potent blood-group-Ii and moderate blood-group-H activities were demonstrated in some of the ganglioside fractions. The gangliosides incorporated into cholesterol/phosphatidylcholine liposomes stoicheiometrically inhibited binding of anti-(blood-group I and i) antibodies to a radioiodinated blood-group-Ii-active glycoprotein. The fraction with the highest blood-group-I-activity, I(g) fraction, behaved like sialosyl-deca- to -dodeca-glycosylceramides on t.l.c. Certain blood-group-I and most of the -i determinants were in partially or completely cryptic form and could be unmasked by sialidase treatment. Thus the I and i antigens, which are known to occur on internal structures of blood-group-ABH-active glycoproteins in secretions, also occur in the interior of the carbohydrate chains of erythrocyte gangliosides.


Inactivation and modification of lactate oxidase with fluorodinitrobenzene. 1. Dinitrophenylation of 2 +/- 0.2mol of residues/mol of enzyme-bound FMN resulted in the complete inactivation of the flavoenzyme L-lactate oxidase. 2. Hydrolysates of the inactivated enzyme contained 1mol each of Nim-Dnp-histidine (abbreviation: Dnp-,2,4-dinitrophenyl-; Nim indicates that either of the N atoms in the imidazole ring is substituted) and epsilon-Dnp-lysine/mol of FMN. 3. Competitive inhibitors decreased the extent of inactivation to a 10% loss of activity, and dinitrophenylation was decreased from 2 to approx. 0.5mol/mol of FMN. Only Nim-Dnp-histidine was detected in the hydrolysates. 4. Although the dinitrophenylated enzyme did not possess enzyme activitiy, L-lactate reduced approx. 50% of the enzyme-bound flavin slowly (0.6min-1), and approx. 50% of the flavin in the modified enzyme-bound flavin slowly (0.6min-1), and approx. 50% of the flavin in the modified enzyme formed a complex with bisulphite. 6. The modified enzyme (2mol of Dnp/mol of FMN) was unable to bind substrate analogues and competitive inhibitors.


Inaccuracies in measurement of conjugated and unconjugated bilirubin in bile with ethyl anthranilate diazo and solvent-partition methods. A criticial evaluation was made of the ethyl anthranilate diazo and two solvent-partition methods for the determination of conjugated and unconjugated bilirubin in human and rat bile. The ethyl anthranilate diazo reagent, which reacts only with conjugated bilirubin in serum, also diazotized a variable proportion of unconjugated bilirubin in bile and thus overestimated the concentration of monoconjugates. With the Weber-Schalm and modified Folsch solvent-partition methods applied to human or rat bile, 4--9% of added 14C-labelled unconjugated bilirubin partitioned with the conjugated bilirubin in the upper phase, and 4--9% of added 14C-labelled conjugated bilirubin partitioned into the lower phase. With dog bile, the spill-over of 14C-labelled bilirubin into the lower phase was 9--11%. Analysis of azopigments from the Weber-Schalm partition confirmed that over two-thirds of the bilirubin in the lower phase represents monoconjugates, principally the less-polar monoxylosides and monoglucosides. These solvent-partition methods thus overestimate the concentration of unconjugated bilirubin in bile.


Involvement of deoxyribonucleic acid polymerase beta in nuclear deoxyribonucleic acid synthesis. The effects on DNA synthesis in vitro in mouse L929-cell nuclei of differential extraction of DNA polymerases alpha and beta were studied. Removal of all measurable DNA polymerase alpha and 20% of DNA polymerase beta leads to a 40% fall in the replicative DNA synthesis. Removal of 70% of DNA polymerase beta inhibits replicative synthesis by 80%. In all cases the nuclear DNA synthesis is sensitive to N-ethylmaleimide and aCTP (arabinosylcytosine triphosphate), though less so than DNA polymerase alpha. Addition of deoxyribonuclease I to the nuclear incubation leads to synthesis of high-molecular-weight DNA in a repair reaction. This occurs equally in nuclei from non-growing or S-phase cells. The former nuclei lack DNA polymerase alpha and the reaction reflects the sensitivity of DNA polymerase beta to inhibiton by N-ethylmaleimide and aCTP.


Primary structure of the major beta-chain of rat haemoglobins. The amino acid sequence of the major beta-chain, (II)beta, from rat haemoglobins was established with an automated sequencer. Amino acid heterogeneities were found that appear to result from allelic variation at particular residues. We applied several new or unusual techniques in determining the sequence: (1) reaction of the polypeptide with dansylaziridine for detection of cysteine; (2) blockage of the N-terminal residue and the epsilon-amino group of lysine residues with 1-fluoro-2-nitro-4-trimethylammoniobenzene iodide and subsequent identification of the modified lysine phenylthiohydantoin by absorbance at 420nm; (3) identification of histidine phenylthiohydantoin by its blue fluorescence under long-wave u.v. light; (4) cleavage of the chain into two or three fragments and subsequent sequencing without purification [a detailed statement giving the major phenylthiohydantoins assigned at each step for each sequence run before their alignment in individual sequences has been deposited as Supplementary Publication SUP 50084 (10 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169, 5]; (5) separation of fragments produced by CNBr cleavage by cation-exchange chromatography; (6) peptide sequencing after attachment of the peptide to cytochrome c. The amino acid sequence was confirmed by amino acid compositions of the complete chain, of CNBr fragments 1 and 3, and of 11 purified tryptic peptides.


Blood-group-I activity associated with band 3, the major intrinsic membrane protein of human erythrocytes. Affinity chromatography of radioiodinated solubilized erythrocyte stroma and of radioiodinated purified Band 3 on an anti-(blood-group I)-adsorbent column showed blood-group-I activity associated with a subpopulation of Band 3. The specificity of binding was confirmed by inhibition with known blood-group substances in radioimmunoassays.


Diffusional increase and decrease in half-maximal-activity substrate concentrations with two-substrate enzymic reactions. Diffusional effects on two-substrate enzymic reactions mainly depend on the relative affinities of the enzyme for its two substrates. With two substrates of widely different affinities, diffusional limitations increase and decrease the half-maximal-activity concentration of the high-and low-affinity substrate respectively.


A spectrophotometric method for the detection of contaminant chymopapains in preparations of papain. Selective modification of one type of thiol group in the chymopapains by a two-protonic-state reagent. A simple spectrophotometric method for the detection of chymopapains A and B, contaminants in some preparations of papain (EC 3.422.2), was devised. If the amount of rapidly reacting thiol in the preparation, as determined by increase in A343 consequent on reaction with the two-protonic-state thiol titrant, 2,2' -dipyridl disulphide, is greater at PH8-9 than at pH4, contamination by the chymopapains is in dicated.


Heparin-sepharose 4B at low temperatures retains ribosomes. Ribosomes were separated by zonal ultracentrifugation from the fraction of reticulocyte postmitochondrial supernatants retained on heparin bound to Sepharose 4B at 4 degrees C. No ribosomes were retained at 22 degrees C. Ribosomes were also adsorbed on Sepharose 4B and 6B at low temperatures and could be eluted after increasing the column temperature.


Thermodynamics for the interaction of epsilon-dinitrophenyl-L-lysine and bovine colostral anti-dinitrophenyl immunoglobulin G2. The effect of varying the temperature over a wide range (4--60 degrees C) on the binding of epsilon-dinitrophenyl-L-lysine to bovine colostral anti-dinitrophenyl immunoglobulin G2 yielded a non-linear van't Hoff plot. The extent of curvature was indicative of a large positive heat-capacity change, and the thermodynamic parameters, calculated by using a non-linear least squares computer procedure, revealed an enthalpy--entropy-compensation mechanism for hapten-antibody binding. The enthalpy factor was found to be the primary contributor for the complex-formation at low temperatures, but at increasing temperatures the entropy factor assumed greater importance. At physiological temperature (39 degrees C), the entropy factor was the major contributor to the free energy of reaction.


Preparation of allosteric ribonuclease.

Preparation of allosteric ribonuclease. A method for the preparation of allosteric ribonuclease from bovine pancreas is described. The effects of freeze-drying ribonuclease from acid and alkaline solutions on plots of velocity versus substrate concentration for the hydrolysis of 2':3'-cyclic CMP are examined. Comparison of these plots with the plots obtained with severeal commercial enzyme preparations indicates that the conformation of the enzyme is dependent on the method of preparation. Aging experiments demonstrate that further conformational changes occur at different rates, depending on the methods of storage. Results suggest that the allosteric behaviour of ribonuclease has not always been observed with commercial preparations, owing to variations in methods of preparation and storage of the enzyme.


The amino acid sequence of the tryptic peptides from actinidin, a proteolytic enzyme from the fruit of Actinidia chinensis. The amino acid sequences of the tryptic peptides of the thiol proteinase actinidin from Actinidia chinensis were determined by the manual dansyl--Edman procedure. There are 12 tryptic peptides, which give a polypeptide chain of 220 residues with a mol.wt. of 23500. An alignment of the tryptic peptides was made by using the X-ray-crystallographic data of Baker [(1977) J. Mol. Biol. 115, 263--277] determined at 0.28 nm resolution on crystalline actinidin. Detailed evidence for the amino acid sequences of the tryptic peptides has been deposited as Supplementary Publication SUP 50083 (14 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169, 5.