Cross-sectional echocardiography in the diagnosis of congenital heart disease. Identification of the relation of the ventricles and great arteries. Using a mechanical sector-scanner, two-dimensional echocardiograms were obtained from 28 normal subjects, 15 patients with tetralogy of Fallot, 11 patients with complete transposition of the great arteries and six patients with double outlet right ventricle. The image obtained perpendicular to the long axis of the left ventricle at the base of the venticular septum was superimposed on the image obtained perpendicular to the long axis at the origin of the great arteries. In normal subjects, these superimposed images demonstrated that the aorta originated posterior and to the left of the ventricular septum. In patients with tetralogy of Fallot, the aorta was displaced anterior and to the right resulting in the aorta over-riding the ventricular septum. In patients with double outlet right ventricle both great arteries originated anterior to the ventricular septum (i.e., from the right ventricle). In patients with complete transposition, the aorta originated anterior and the pulmonary artery posterior to the ventricular septum. Thus, cross-sectional echocardiography permits noninvasive identification of the relation of the ventricles and great arteries and, therefore, provides important information for the diagnosis of patients with congenital heart disease.


Echocardiographic assessment of a normal adult aging population. Echocardiograms were performed on 105 male participants in the National Institutes on Aging's volunteer Longitudinal Study Program. All subjects (25--84 years of age) were physically active and had no evidence of hypertension or cardiovascular disease. Measurements were made of the initial diastolic (E-F) slope of the anterior mitral valve leaflet, the aortic and left ventricular cavity dimensions, and the thickness of the posterior left ventricular wall. Fractional shortening of the minor semi-axis of the left ventricle and the velocity of circumferential fiber shortening were also determined. It was found that increasing age correlated with a decrease mitral valve E-F slope and increased aortic root diameter and left ventricular wall thickness. Aging did not affect left ventricular cavity dimension, fractional shortening of the minor semi-axis, and velocity of circumferential fiber shortening. These findings suggest that aging in the normal male is associated with altered left ventricular diastolic filling, increased aortic root diameter and left ventricle hypertrophy but little change in contractile ability in the resting state.


Echocardiographic measurement of right ventricular wall thickness. A new application of subxiphoid echocardiography. The feasibility of subxiphoid echocardiography to measure the thickness of the right ventricular wall (RVWT) was investigated. In 87 (90.6%) of the 96 patients studied, adequate visualization of the echoes from the right ventricular wall was obtained using the subxiphoid technique. RVWT averaged 0.34 +/- 0.08 cm (mean +/- 1 SD), ranging from 0.2 to 0.5 cm in 25 normal individuals. This was not significantly different from the values in the left ventricular overload group (0.36 +/- 0.10 cm). However, the RVWT was increased significantly (P less than 0.001) in the combined group (0.62 0.18 cm), the right ventricular (RV) pressure overload group (0.60 +/- 0.13 cm) and the RV volume overload group (0.53 +/- 0.11 cm). Thirty-two patients underwent diagnosis right heart catheterization which revealed a good correlation between the RVWT measured echocardiographically and the right ventricular peak systolic pressure (r = 0.84). Subxiphoid echocardiography was considered to be useful in diagnosing right ventricular hypertrophy in adults.


The effect of propranolol on canine myocardial CPK distribution space and rate of disappearance. Canine myocardial CPK was partially purified and injected into 11 conscious mongreal dogs. From serial serum CPK measurements in each dog, mean Kd was calculated as 0.0047 +/- 0.0009 (+/- SD) min-1. Correlation coefficients indicated that CPK disappearance rate was well described by a single exponential expression. Kd measured on consecutive days in four dogs varied minimally. CPK distribution space ranged from 74 to 134% of plasma volume. Propranolol loading with 0.3 mg/kg or 2 mg/kg, followed by hourly maintenance doses, resulted in increased Kd in eight of ten dogs, mean Kd rising from .0048 min-1 to .0059 min-1 (P less than 0.02). Propranolol appeared to increase plasma volume but had no significant effect on the relationship of CPK distribution space to plasma volume. If the serial CPK technique were used to measure infarct size, using an average Kd, propranolol might produce artifactual reduction of infarct size measuremnt by increasing Kd and possibly by increasing plasma volume. The obligation to assess the effect upon CPK Kd and distribution space of an agent designed to limit infarct size is apparent.


Effect on training on myocardial oxygen supply/demand balance. In five well-trained and five sedentary control subjects potential subendocardial blood supply was estimated from the diastolic pressure time index (DPTI) and myocardial oxygen demands from the tension time index (TII) during a progressive near-maximal treadmill test. DPTI/TTi was used to assess the effects of training on myocardial oxygen supply/demand balance. DPTI/TTI was significantly higher in trained subjects at rest and comparable workloads. At 6.4 km/hr, 18% grade (maximum for the controls), TTI was significantly lower (4300 +/- 76 vs 4495 +/- 99 mm Hg-sec/min) and DPTI significantly higher (2534 +/- 86 vs 2295 +/- 91 mm Hg-sec/min) in the trained subjects; DPTI/TTI was significantly higher (0.59 +/- .02 vs 0.50 vs .03). At near-maximal heart rates both groups achieved the same supply/demand balance (0.50); however, the trained subjects were working at higher workloads. We conclude that endurance conditioning increases work capacity, reduces myocardial O2 demands, increases potential O2 supply and improves the supply/demand balance at any given submaximal workload which reduces the risk of ischemia.


Chronic congestive heart failure after repair of tetralogy of Fallot. The etiology of chronic congestive heart failure (CHF) after repair of tetralogy of Fallot was determined in 102 patients consecutively catheterized 1 to 12 years postoperatively. Chronic CHF was observed in 36/102 patients. The most prevalent abnormality leading to congestive failure (31/36) was a large residual ventricular septal defect alone or in combination with other lesions. All postoperative patients with pulmonary to systemic flow ratios greater than 2:1 (25/102) had congestive failure and evidence of biventricular dysfunction. Significant tricuspid regurgitation (N = 11) and persistent systemic to pulmonary artery shunts (N = 6) contributed to volume overload and congestive failure in the patients with large residual ventricular septal defect. Isolated severe residual right ventricular outflow tract obstruction was a common cause of chronic CHF. Pulmonary artery hypertension was present in 20/36 patients with CHF. The increased pulmonary pressure was not wholly due to an increased pulmonary flow since 7/20 patients had pulmonary vascular resistance greater than 3 mm Hg/L/min/m2. Our findings indicate that persistent or chronic congestive heart failure in postoperative tetralogy of Fallot patients requires bilateral cardiac catherterization since an identifiable and surgically correctable lesion is nearly always present.


Abnormal left ventricular contraction pattern in the systolic click-late systolic murmur syndrome. A contraction abnormality of the left ventricle has previously been described in patients with systolic click-late systolic murmur syndrome. To determine if the contraction abnormality is present in the preprolapse period, LV dimensions and the instantaneous velocity of circumferential fiber shortening (VCF) were studied in 18 patients with the mitral valve prolapse and 16 normal subjects using computer analysis of echocardiograms. VCF attained its maximum (max VCF) during the preprolapse period an average of 94 msec before the mid-systolic click. Max VCF was significantly reduced in patients with mitral valve prolapse (2.06 vs 2.55 circ/sec in normal subjects, P less than 0.001). Despite the reduction in max VCF, no difference in the extent and percentage of diameter shortening was found between patients and normal subjects. This discrepancy is explained by a sustained rate of mid-to-late systolic diameter shortening in the presence of mitral valve prolapse as manifested by a typical VCF profile (P less than 0.001) and a longer duration of diameter shortening (353 vs 306 msec in normal subjects, P less than 0.01). The decrease of max VCF in patients with mitral valve prolapse suggests a reduction in LV contractility. Since the abnormality is present in the preprolapse period, it is unrelated to a direct mechanical effect of the prolapse itself. Additional fiber shortening in mid-to-late systole indicates that the sudden displacement of the mitral leaflets may have an unloading effect on the left ventricle.


Effect of increased free fatty acids on myocardial oxygen extraction and angina threshold during atrial pacing. To evaluate whether elevated arterial free fatty acids (FFA) increase myocardial oxygen demand and ischemia, 15 fasting patients with coronary artery disease underwent a standardized atrial pacing test before (PTI) and during (PT2) heparin infusion. The patients were monitored for clinical and electrocardiographic (ECG) manifestations of ischemia. Myocardial extraction of lactate, inorganic phosphate, oxygen and FFA was measured before and during each PT. The control arterial FFA was 0.65 +/- 0.03 micromole/ml and rose to 1.83 +/- 0.16 micromole/ml during heparin influsion. Myocardial oxygen extraction at rest and during PT was not affected by the increase in arterial FFA. Seven patients asymptomatic during PT1 did not develop ischaemic manifestations during PT2. In eight patients with angina during both PTs, increased arterial FFA concentration did not modify the severity of anginal pain, the amount of ST-segment depression and the myocardial balance of lactate or inorganic phosphate. Elevation of arterial FFA by heparin neither increased myocardial oxygen extraction at rest or during pacing nor accentuated ischemic manifestations during PT.


Clinicopathologic correlations. De subitaneis mortibus. XXV. Sarcoid heart disease. Postmortem findings within the cardiac conduction system are described from the case of a black woman with sarcoid heart disease who died suddenly. Her clinical course had been characterized by recurring ventricular arrhythmias and bouts of syncope. Both the sinus node artery and the atrioventricular (A-V) node artery were sites of focal fibromuscular dysplasia, which thickened slightly the wall of the former but markedly narrowed the lumen of the latter. Small foci of sarcoid infiltration were present in the sinus node and the A-V node. Fatty replacement within the His bundle was attributable to the probable ischemia caused by narrowing of the A-V node artery. Sarcoid granulomata and infiltration with epithelioid cells were present throughout the ventricular myocardium, but were conspicuously less prevalent in the atria. All the large coronary arteries were normal. Many small coronary arteries in the ventricular myocardium were involved by the sarcoidosis and their lumen were narrowed. These findings and analogous ones reported by others are discussed relative to the pathogenesis of syncopal attacks and sudden death which seem to peculiarly prevalent in sarcoid heart disease.


Clinical course in adults with ventricular septal defect. The 38 adult patients admitted to the Natural History Study with a small ventricular defect had a generally favorable course, similar to that noted in children and adolescents. None died under medical or surgical management, and none deteriorated. Among patients treated medically, complete closure was demonstrated during the course of follow-up in one, and in the others, wo were catheterized, the shunt remained the same or decreased slightly. Significant vascular disease did not develop in any of the patients. Among seven surgically-treated patients for whom data were complete, the defect was completely closed in six. In 18 patients who had large ventricular septal defects and mild or moderate pulmonary vascular disease, no significant change occurred in the four who were managed medically. Of 14 who underwent surgery, two died; six of eight who were recatheterized had normal pulmonary arterial pressure, with no residual shunt in four and a trivial shunt in two. Two patients who had had moderate vascular disease preoperatively (RP/RS was 0.4 in both) had open defects and slightly higher resistance ratios at final catheterization. Of the 18 patients with Eisenmenger's syndrome, eight died during the study, including one of two who underwent surgery. The other surgical patient survived and showed significant hemodynamic improvement at final catheterization.


Bacterial endocarditis in patients with pulmonary stenosis, aortic stenosis, or ventricular septal defect. Bacterial endocarditis developed in 24 patients during follow-up in the Natural History Study. It occurred significantly more often in patients with ventricular septal defect (1.5/1000 patient-years) and aortic stenosis (1.8/1000 patient-years) than in those with pulmonary stenosis (0.2/1000 patient-years). Complications, especially emboli and aortic regurgitation, occurred in 50% of the patients. Overall mortality was 25%. Incidence rates were significantly greater for males than for females and greater for patients over 20 years of age than for younger patients. Patients who had had ventricular septal defect treated surgically had a lower incidence of endocarditis than non-surgical patients, whereas surgery did not reduce the incidence in patients with aortic stenosis. The estimated risk of contracting bacterial endocarditis prior to 30 years of age in a patient with medically-treated ventricular septal defect is 9.7%; the risk estimate for surgical patients in 2.0%. Although data regarding the use of prophylactic antibiotics were not available for patients in the Natural History Study, these results certainly suggest that continued antibiotic prophylaxis for dental and certain surgical procedures is mandatory for patients with aortic stenosis, even after successful cardiac surgery. It is the authors opinion that prophylaxis is probably less necessary for patients who have pulmonary stenosis, whether surgically treated or not, and for patients with documented complete closure of VSD.


Asthma due to inhaled chemical agents--epoxy resin systems containing phthalic acid anhydride, trimellitic acid anhydride and triethylene tetramine. Six workers with a diagnosis of occupational asthma and one with chronic bronchitis were examined for sensitivity to epoxy resin systems and certain of their components. In six cases the chemical agent responsible for their symptoms was identified by careful inhalation challenge testing, simulating their exposure at work and thus providing a precise aetiological diagnosis. In one worker asthma followed exposure to triethylene tetramine fume; four were sensitive to acid anhydrides, three to phthalic acid anhydride as a fume or powder and one to trimellitic anhydride. On worker thought to be sensitive to toluene di-isocyanate gave negative reactions to this and positive reactions to a phthalic acid anhydride epoxy resin and another thought to have asthma from acid anhydride fumes was found to be sensitive only to toluene di-isocyanate. Immediate, non-immediate or combined asthmatic reactions were elicited.


Phthalic anhydride asthma.

Phthalic anhydride asthma. A patient with occupational asthma caused by phthalic anhydride is described. Inhalation challenges under laboratory control produced immediate and delayed asthmatic responses. Repeat exposure to phthalic anhydride after treatment with cromolyn sodium showed inhibition of the late but not early bronchoconstrictive, asthmatic response.


Respiratory allergy and month of birth.

Respiratory allergy and month of birth. A total of 476 patients with respiratory allergy were interviewed to establish whether the season of birth influenced the type of allergy experienced. Patients with perennial symptoms did not differ from the general population of the U.K. in the distribution of their months of birth. Patients with summer seasonal symptoms attributable to grass pollen sensitivity were more likely to have been born in December to February than in August to November. This trend was most significant in female patients who did not have associated perennial symptoms and who developed symptoms early in life. Other significant differences were also noted between groups of patients complaining of the same symptoms. More males than females had summer seasonal symptoms whereas more females than males had perennial symptoms. Patients who had both perennial symptoms and summer seasonal exacerbations had a higher incidence of a positive family history of atopy and developed symptoms earlier in life than those patients who had summer seasonal or perennial symptoms only.


Treatment of chronic urticaria with a beta2-adrenergic stimulant. Twenty-four patients with chronic utricaria resistant to conventional therapy were treated orally with terbutaline, a specific beta2 stimulant. This therapy was much more effective than antihistamines. At the dose of 1-25 mg three times a day, there were few side effects. The efficacy was independent of the IgE levels; it seemed greater in idiopathic cases than in cholinergic or pressure induced urticaria.


Results of a controlled trial of the acaricide paragerm on Dermatophagoides spp. in dwelling houses. The effect of Paragerm spray from either a hand pressurized can or from a general room mist device (MCR device) on mattress mite populations was compared with the effect of a control spray. After 1 month a reduction in mite population due to the cleaning procedures was evident in the control treated mattresses; Paragerm treated mattresses had significantly fewer mites, notably those treated with the aerosol can spray, nine out of fifteen of which were mite free. Dissection of the mattresses showed that some mites survive and they could form the nucleus from which reinfestation could occur.


Inactivation of heamolytic complement by house dust allergen in the serum of children with atopic diseases. Purified house dust allergen has been employed for screening the susceptibility to inactivation of haemolytic complement in the blood serum of atopic children and control subjects. Fluid phase complement in the control group of children was more sensitive to allergen-induced inactivation than observed in a normal adult population. Though the mean complement sensitivity indices in all groups of patients were below the valve for the control group, there was considerable statistical overlap. The serum complement sensitivities were in no way related to the clinical manifestations. The results of the complement test were not correlated to the total IgE levels, the RAST scores nor the skin reactions with house dust allergen. Some evidence for the in vivo involvement of the complement system in childhood atopic allergy was provided: the mean C3 proactivator level was significantly lower in atopic children, than in the control group; the mean C4 level in children with bronchial asthma and in children with atopic dermatitis was significantly depressed. A significant positive correlation between the serum C4 levels and allergen-complement sensitivities in children with both bronchial asthma and atopic dermatitis was observed.


A study of the effects of systemic administration of adrenal glucocorticoids in an experimental model of hypersensitivity pneumonitis. To study the effects of steroids on the pulmonary lesions in experimental hypersensitivity pneumonitis, rabbits were sensitized to ovalbumin (OA) by injections of OA into footpads and 3 weeks later they were subjected to two successive aerosol challenges with OA at an interval of 48 hr. Injections of hydrocortisone sodium succinate 10 mg twice daily (but not at the reduced dosage of 5 mg twice daily) or methyprenisolone acetate 5 mg twice daily beginning 30 min before the first challenge and continued to the time of killing reduced the extent and intensity of vasculitis in both the treated groups and showed less alveolar septal thickening in the hydrocortisone treated group and less alveolar consolidation in the methylprednisolone treated group compared to the pulmonary lesions in the rabbits which were sensitized and then subjected to OA aerosol challenges, but received no treatment. In view of the observation that even in a steroid sensitive species like the rabbit, extensive pulmonary changes like alveolar consolidation, septal thickening and vasculitis persisted in spite of treatment with relatively large doses of these steroids, it was felt that in human hypersensitivity pneumonitis steroids might only suppress the warning symptoms without substantially affecting the progress of the pulmonary lesions.


House dust mites in Iran.

House dust mites in Iran. In the Caspian Sea region of Iran asthma seems closely related to house dust allergy. Since a high proportion of house dust sensitive patients appear to be sensitive to house dust mites, an investigation was carried out to determine the occurrence, distribution and abundance of these species in Iranian house dust in order to assess their role and clinical importance in house dust allergy in Iran. Thirty-five samples of house dust collected from houses in the Caspian Sea region and five samples from other areas were examined for mites. The three pyroglyphid species Dermatophagoides pteronyssinus, D. farinae and Euroglyphus maynei, reported by European and Japanses workers to be common in house dust and to be a major source of house dust allergens, were found to occur in Iranian house dust and to account for nearly two-thirds of the total mit population present in the dust. Dermatophagoidex pteronyssinus was the most frequent and most numerous species recorded, occurring in 90% of the samples examined and forming 94% of the pyroglyphid and 60% of the total mite population. The frequency with which house dust mites were found in the Iranian Caspian Sea region coupled with the relatively high frequency of allergic bronchial asthma in this area suggests that they may well be an important precipitating factor in asthma in Iran.


Diagnostic and therapeutic problems associated with hereditary deficiency of the C1 esterase inhibitor. Six patients in a family with a history of hereditary angioedema reported swelling of the extremities and recurrent abdominal pain occurring spontaneously or after trauma. Attacks of oedema involving the airways, the greatest danger with this disorder, were present only in one case. This autosomal dominant disease is due to deficient activity of the inhibitor of the first component of complement. Low levels of C4, and absence of C1 esterase inhibitor confirm the diagnosis. Two asymptomatic cases with the appropriate biochemical abnormality are reported in this study. For short term prophylaxis of attacks (before surgery expecially), fresh frozen plasma is used, or better still, C1 esterase inhibitor. For long term prophylaxis of attacks antifibrinolytic and hormonal drugs are used: in two cases, the authors obtained good results with methyltestosterone after failure of tranexamic acid.


Serological investigations in hymenoptera sting allergy: IgE and haemagglutinating antibodies against bee venom in patients with bee sting allergy, bee keepers and non-allergic blood donors. Specific IgE-antibodies and haemagglutinins to bee venom were determined in fifty-five bee sting allergic patients, fifty-seven bee keepers and fifty-two blood donors without evident allergy to hymenoptera stings. IgE-antibodies were detected by RAST in 70% of allergic patients, 40% of bee keepers and 12% of blood donors. Most bee keepers with detectable IgE-antibodies to bee venom recorded severe local or even general reactions to bee stings. Most blood donors with detectable specific IgE had been stung by hymenoptera in the past. High titres of haemagglutinating antibodies against phospholipase A were found in most bee keepers, occasionally in bee sting allergic patients but only rarely in blood donors. The determination of specific IgE-antibodies to insect venoms by RAST seems to be a valuable method for the diagnosis of hymenoptera sting allergy.


Circulating immune complexes in patients with atopic allergy. Sera from forty-nine patients with atopic allergy were tested for the presence of circulating immune complexes by the sensitive, quantitative Clq assay. Compared to twenty-five normal individuals the atopic patients had significantly higher mean values of Clq reactive material, expressed as Clq inhibition values. The highest mean values were seen in the group (twenty-one patients) who had been on long term maintenance immunotherapy for 5 or more years. When positive sera were fractionated by ultracentrifugation on sucrose density gradients, the Clq reactive material was found in intermediate (7S-19S) and heavy (greater than 19S) regions. The heavy material contained both IgM and IgG. It is suggested that the IgG antibodies known to be produced by chronic hyposensitization procedures in allergic individuals may circulate in the serum as antibody-allergen immune complexes, and could carry out their blocking action in this form.


Comparision of a glutaraldehyde-modified pollen--tyrosine adsorbate with an alum-precipitated pollen vaccine in the treatment of hay fever. Nineteen patients with hay fever symptoms received nine weekly injections of pyridine-extracted alum-precipitated grass pollen vaccine (Alavac P). The results were compared with agroup of twenty patients who received a three injection series of a glutaraldehyde-modified pollen-tyrosine vaccine (Pollinex). In both groups 65% had a subjective improvement in their symptoms and no significant difference in symptom scores was obtained throughout the pollen season. In the Pollinex group a lower incidence of systemic side effects was recorded.


Specific IgE antibodies in nasal secretion from patients with allergic rhinitis and with negative or weakly positive RAST on the serum. Nasal secretions from eighteen patients with allergic rhinitis with a positive case history, intradermal test and nasal provocation test, but with negative or only weakly positive RAST (radioallergosorbent test) on the serum against a total of thirty-five allergens, were studied. In the RAST an immunosorbent-purified anti-IgE with DE2 specificity was used, which raised the detection limit. Nasal secretion was collected by washing the nasal mucosa with 0-9% and 18% NaCl solution respectively, and the latter secretion was also luophilized and concentrated. In ten cases RAST was slightly positive on the nasal secretion, and in three of the concentrated secretions the RAST value was higher than on the serum. In none of the serum or nasal secretion samples was RAST positive according to the cut off value for a positive result defined by the reference system used in Phadebas Rast. From these results it is concluded that RAST analyses of nasal secretion from patients with allergic rhinitis is of no appreciable value in routine clinical allergological diagnosis. However, the increased sensitivity of RAST obtained with isotope-labelled anti-DE2 may be useful in the serological diagnosis of patients with low grade allergy having low levels of IgE antibodies in serum.


Simultaneous determination of hemoglobin derivatives, oxygen content, oxygen capacity, and oxygen saturation in 10 microliters of whole blood. We describe a new method for simultaneous determination of four hemoglobin derivatives (deoxyhemoglobin, Hb; oxyhemoglobin, HbO2; methemoglobin, Hb+; and carbon monoxide hemoglobin, HbCO) and total oxygen content in 10 microliters of whole blood. Percentage HbO2, HbCO, Hb+, total hemoglobin (Hbt), and oxygen capacity can also be obtained from the experimental data by simple calculations. Total analysis time is 1 min. Blood is diluted 100-fold with a buffer contained in a quasi-anaerobic cuvette, where simultaneous measurements of oxygen pressure (by a po2 electrode) and adsorbance (at 497, 565, and 620 nm) are made. The decrease of oxygen pressure, as recorded by the oxygen electrode, is proportional to the amount of deoxyhemoglobin. The concentrations of HbO2, HbCO, and Hb+ can be obtained from absorbance measurements at the specified wavelengths. The new method eliminates the use of short-path optical cells and, due to the low sample volume requirement, makes possible the automated measurement of hemoglobin derivatives and oxygen saturation in arterialized capillary blood.


Evaluation of a discrete samples/stopped-flow mixer system for equilibrium and kinetic analyses. This paper describes the evaluation of a system for computer-controlled discrete sampling and stopped-flow mixing for equilibrium and kinetic determinations of several sorts of analytes in human serum. The instrumental system features a wash-out sampling system that permits rapid change-over from one sample and (or) reagent type to another, and a mixing-measurement system that can provide reliable data as soon as 10 ms after reagent and sample are mixed. Examples discussed include equilibrium procedures for glucose and cholesterol, slow kinetic procedures for glucose and lactate dehydrogenase, and a fast kinetic method for thiocyanate. The regression equation for all stopped-flow results (n = 114) vs. results by conventional methods is y = (103 +/- 0.01)x - (0.016 +/- 0.019) for numerical values of y between 0.3 and 3.0. The correlation coefficient for these data was 0.991. These results demonstrate that the stopped-flow method is a viable analytical approach for equilibrium, slow kinetic, and fast kinetic determinations that require measurement times shorter than 0.1 s.


Analysis for platinum in biological material by flameless atomic absorption spectrometry. A method for determining platinum in biological materials by flameless atomic absorption spectrometry has been developed for use in pharmacological studies of platinum antitumor compounds. Tissue digests are analyzed in a heated graphite atomizer, with use of background correction and ramp temperature charring. We have overcome problems of apparent loss of platinum in Pt-supplemented tissue samples with time and of difficulty in analyzing tissue lipid. The validity of the assay was verified by injecting rats with radiolabeled cis-dichlorodiammineplatinum (II), then measuring platinum in tissues by gamma scintillation spectrometry and flameless atomic absorption spectrometry. Correlation between the two methods was excellent. The limit of the assay in its present form is about 0.1 migrogram/gram of wet tissue.


Automation of radioimmunoassays for some sex steroids with use of both iodinated and tritiated ligands. We describe an automated technique for estradiol, progesterone, and testosterone, in which System Olli 3000 pipetting and incubation units are used. After extraction or chromatography, steroids are redissolved in ethanol or buffer, and duplicate aliquots are arranged for radioimmunoassay in 24-tube blocks. Addition of antibodies, tracers (125I or 3H), dextran-coated charcoal for separating free and bound ligands, and removal of a portion of the supernate for counting are all performed by the pipetting instrument. Incubations are at 37 degrees C in the incubation unit, or at 4 degrees C. After counting, steroid concentrations are computed from punch tape records by a Nova 840 computer. The management of assays in 24-tube units, and accurate simultaneous pipetting has reduced experimental error, and because there is no carryover, many different assays can be performed concurrently or in rapid sequence. Various scintillation media are compared.


Radioimmunoassay for free and conjugated urinary metanephrine. We describe a convenient and specific radioimmunoassay for urinary metanephrine, in which we used an antiserum generated in rabbits by injecting with synephrine conjugated to bovine serum albumin as described by Grota and Brown [Endocrinology 98, 615 (1976)]. The antiserum is specific for metanephrine and epinephrine. Epinephrine cross reaction is minimized to 1% by adding 2 ng of epinephrine to each assay tube. Incubation time is 12 h. The sensitivity of the assay is 40 pg. Within-and between-assay coefficients of variation are 7.0 and 9.7%, respectively. We assayed first-voided morning urine and 24-h urine specimens from 15 normal subjects before and after acid hydrolysis, to assess total and free metanephrine concentrations. Mean (+/-SD) total and free urinary metanephrine excretion were 17 +/- 11 and 3.5 +/- 1.0 micrograms/24 h in these subjects; corresponding values for the morning specimens were 13.4 +/- 8.3 and 3.5 +/- 1.5 micrograms/liter, respectively.


Determination of urinary normetanephrine, metanephrine, and 3-methoxytyramine by liquid chromatography, with amperometric detection. We describe a sensitive procedure for measuring the basic catecholamine metabolites--normetanephrine, metanephrine, and 3-methoxytyramine--in urine by use of liquid chromatography, with electrochemical detection. These substances are isolated from hydrolyzed urine by passage through small ion-exchange columns and then pre-concentrated by a rapid set of solvent extractions before being injected onto the liquid-chromatographic column. Concentration and instrumental response are linearly related to 2.0 mg/liter for all three compounds, and practical lower detection limits are about 20 micrograms/liter for actual urine samples. The high selectivity that accrues from the combination of the extraction procedure, high-performance liquid chromatography, and electrochemical detection makes this procedure suitable for quantitative studies of catecholamine metabolism. A set of six samples can be taken through the extraction procedure in parallel in less than 2 h; once prepared, the extracts can be analyzed at a rate of three per hour.


Determination of "true" serum creatinine by high-performance liquid chromatography combined with a continuous-flow microanalyzer. We coupled a high-performance liquid chromatograph with a continuous-flow microanalyzer to produce a system for specifically determinig "true" creatinine in urine and serum specimens. A selective microbore pellicular cation-exchange column and a single eluting sodium citrate buffer are used to separate the noncreatinine but Jaffé-positive constituents from the creatinine in normal and experimental specimens. The effluent is analyzed continuously, on-line, the alkaline picrate complex being developed and measured in the microanalyzer. Physiological samples, reference standards, and internal control specimens are assayed in 6-min intervals subsequent to the initial injection. The relationship between concentration and peak are is linear for creatinine standards between 5 and 10 mg/liter. Specimen volumes ranging from 1 to 25 microliters, and containing creatinine in amounts exceeding 5 ng per injected sample, can be assayed with this system.


Improved assessment of plasma lipoprotein patterns. III. Direct measurement of lipoproteins after gel-electrophoresis. Based on a previously described technique [Clin. Chem. 19, 737 (1973)] of precipitating plasma lipoproteins with polyanions after their electrophoretic separation in gels, a new method is presented for measuring normal plasma lipoproteins densitometrically. The method is fast and easy; the CV for beta-, pre-beta-, and alpha-lipoproteins was less than 5% in one series. Results are linearly related to concentration up to 10 g of total lipoprotein per liter. No unusual equipment is required. Standardization is done with the aid of a commercially available filter. Total plasma cholesterol and cholesterol calculated from quantified lipoprotein fractions were highly (r = 0.963) correlated.


Simultaneous determination of iron, zinc, selenium, rubidium, and cesium in serum and packed blood cells by neutron activation analysis. We determined the iron, zinc, selenium, rubidium, and cesium concentrations in serum and packed blood cells by instrumental neutron activation analysis without chemical separations. Lyophilized samples were irradiated for 12 days at a flux of 10(13) neutrons-cm-2-s-1, mineralized by wet digestion, and measured two times with a high-resolution Ge(Li) detector--for 6 h about a month after the irradiation and for 15 h two or three months after the irradiation, The following values were obtained: 163 +/- 0.43 mg/liter (serum iron), 1025 +/- 136 mg/kg wet wt (packed cells iron), 1¿ +/- 0.20 mg/liter (serum zinc), 11.15 +/- 1.83 mg/kg wet wt (packed cells zinc), 0.13 +/- 0.02 mg/liter (serum selenium), 0.16 +/- 0.03 mg/kg wet wt (packed cells selenium), 0.17 +/- 0.04 mg/liter (serum rubidium), 4.28 +/- 0.98 mg/kg wet wt (packed cells rubidium), 0.74 +/- 0.20 microgram/liter (serum cesium), and 4.82 +/- 2.10 microgram/kg wet wt (packed cells cesium).


Measurement of thiamylal and thiopental in plasma by electron capture and flame photometric gas-liquid chromatography. We describe an isothermal gas-liquid chromatographic procedure developed for measuring thiamylal and thiopental in plasma. The unchanged drug is extracted into ethyl acetate from acidified plasma, together with an internal standard. The solvent is removed, the residue methylated, aliquots, diluted with benzene, are injected into a 183-cm gas-liquid chromatographic column containing 3% OV-17. Sensitivity of detection is in the nanogram to picogram range.


Determination of plasma procainamide and N-acetylprocainamide concentration by high-pressure liquid chromatography. We describe a routine method for determining concentrations of the antiarrhythmic drug procainamide and its active metabolite, N-acetylprocainamide, in plasma. A simple extraction of 1.0 ml of plasma is followed by separation and chromatographic analysis by use of a column containing microparticulate silica. p-nitro-N-(2-diethylaminoethyl)benzamide hydrochloride was synthesized and used as the internal standard. Total chromatographic time is only 7 min. The day-to-day CV during three months of daily use was less than 4% of the mean for each compound, and we saw no deterioration in column performance during this time. Phenobarbital, phenytoin, lidocaine, primidone, methsuximide, quinidine, and their metabolites do not interfere.


Improved colorimetric determination of serum zinc. We show how zinc may easily be quantified in serum by first using an optimum concentration of guanidine hydrochloride to cause release of zinc from proteins, followed by complexation of released metals with cyanide. The cyanide complex of zinc is preferentially demasked with chloral hydrate, followed by a colorimetric reaction between zinc and 4-(2-pyridylazo)resorcinol. This is a sensitive water-soluble ligand; its complex with zinc has an absorption maximum at 497 nm. Values found by this technique compare favorably with those obtained by atomic absorption spectroscopy.


Elimination of glucose interference and improved precision in a continuous-flow analysis for inulin. A modified fermentation procedure based on one described by Homer Smith in his textbook was used to eliminate glucose interference in the automated detrmination of inulin. The manifold of Fjeldbo and Stamey [J. Lab. Clin. Med. 72, 353 (1968)] was modified to enable us to insert the fermentation procedure without sacrificing precision in continuous-flow analysis for inulin. Analytical recoveries of inulin from plasma and urine with the modified manifold were 100.1 +/- 0.8% (SD) and 99.9 +/- 1.6%. Corresponding recoveries of inulin from specimens of plasma and urine containing 5 g of glucose per liter and treated with yeast were 99.6 +/- 1.5% and 100.0 +/- 1.6%.


Therapeutic monitoring of tricyclic antidepressants in plasma by gas chromatography. We describe a comprehensive gas chromatographic analysis for therapeutic concentrations of amitriptyline, nortriptyline, imipramine, desipramine, doxepin, and desmethyldoxepin in plasma, with use of a nitrogen detector. All these drugs are extracted and chromatographed under identical conditions. Each tertiary amine tricyclic is well resolved from its secondary amine metabolite on a mixed-phase column and the concentrations of both are determined simultaneously, without derivatization. The lower limit of sensitivity is 10 microgram/liter of plasma (2-ml sample). Analytical recoveries of the tertiary and secondary amines are 100 and 80%, respectively. Between-run CV's for all of the drugs ranged between 5 and 7%.


Creatine kinase isoenzyme activity in human placenta and in serum of women in labor. Creatine kinase (EC 2.7.3.2) isoenzymes in extracts of human placenta and in serum from nonpregnant women and women in labor were separated on columns containing diethylaminoethyl-cellulose and assayed. The distribution of the isoenzymes in placenta (n = 10) was 80% BB (200 +/- 66 U/g (wet weight), 19% MM (49 +/- 30 U/g), and 1% MB (2.6 +/- 1.7 U/g); The geometric mean for the serum BB activity of the nonpregnant women (n = 50) was 0.6 +/- 1.5 U/liter, as compared to 3.0 +/- 1.4 U/liter for patients in labor who had normal deliveries (n = 92). The arithmetic mean for serum BB activity of labor patients with induced labor (n = 20), premature labor (n = 7), cesarian section (n = 6), or hypertension and pre-eclampsia (n = 6) did not differ significantly from the arithmetic mean BB activity for serum of labor patients with normal deliveries. However, the arithmetic mean serum BB activity of patients with stillbirths (n = 7) was significantly smaller than the arithmetic mean for normal labor patients.


Assessment of a method for measuring serum thyroxine by radioimmunoassay, with use of polyethylene glycol precipitation. We assessed the efficacy of a new thyroxine radioimmunoassay kit (Abott) in which polyethylene glycol is used to separate bound from free hormone. Mean serum thyroxine was 88 +/- 15 (+/-SD) microgram/liter for 96 normal persons. Results for hypothyroid and hyperthyroid persons were clearly separated from those for normal individuals. Women taking oral contraceptive preparations showed variable increases in their serum thyroxine values. The coefficient of variation ranged from 1 to 3% within assay and from 5.4 to 11% among different assays. Excellent parallelism was demonstrated between thyroxine values estimated by this method and those obtained either by competitive protein binding or by a separate radioimmunoassay for the hormone.


Micromethod for determination of diazepam by electron-capture gas-liquid chromatography. We used 100 microliters of plasma for the determination of diazepam. After the internal standard, prazepam, is added, the serum is directly extracted with diethyl ether, the extract is evaporated, the residue is dissolved in ethanol, and the drug is measured by gas-liquid chromatography, with use of an electron capture detector. With this procedure, 2.5 ng of diazepam in the sample can be speedily measured with specificity, accuracy, and reproducibility (CV = 4.5%).


Positive interference with the Jaffé reaction by cephalosporin antibiotics. Cephaloglycin, cephalothin, cephaloridine, cefoxitin, and cephacetrile are cephalosporin antibiotics that react with alkaline picrate solution to give a creatinine-like response. The mechanism of this reaction is not known, and several structurally similar compounds do not react under these same conditions. Because large quantities of a cephalosporin antibiotic may be administered to a patient with limited ability to excrete the drug (as occurs with compromised renal function), the magnitude of this interference can be appreciable. It does not appear possible to avoid the cephalosporin-caused interference by the use of "kinetic" creatinine methods.


Impact of posture on the "reference range" for serum proteins and calcium. The impact of water shifts due to changes in posture has been reinvestigated for serum protein and calcium concentrations in a young, healthy population. We found that generaly accepted normal ranges for total serum protein, and to a lesser degree for total serum calcium, are not acceptable as a reference range for a hospitalized population that is predominantly in a supine position. Our data indicate a smaller biological variability for total protein and calcium for a reference population in the recumbent posture as compared to the same population in the upright position.


Heparin pretreatment suppresses norepinephrine concentrations in dogs in endotoxic shock. Mongrel dogs were treated intravenously with either 1000 units of beef-lung heparin per kilogram of body weight or with isotonic saline, before intravenous administration of E. coli endotoxin. We found significant differences in circulating norepinephrine concentrations between a heparin-pretreatment group (1.89 +/- 0.39 microgram/liter) and the control group (9.83 +/- 4.64 microgram/liter), but none with respect to epinephrine. Systolic blood pressures at 360 min were also significantly (P less than 0.05) different, 148 +/- 6 mmHg as compared with 118 +/- 13.4 mmHg. Evidently heparin pretreatment can decrease circulating norepinephrine concentrations in the endotoxic state and changes in circulating catecholamine concentrations can affect physiological variables.


Measurement of free thyroid hormones in serum by dialysis and gas chromatography. We describe a simultaneous, absolute analysis for free (dialyzable) triiodothyronine and thyroxine in serum by the sequence: dialysis, internal standard addition to the dialysate, cation-exchange chromatography, derivatization, and gas chromatography with electron capture detection. The detection limit is 0.2 pg and the precision (repeatability) in the range of 4 to 20 ng/liter is 1.6%. Mean values for free T3 and T4 in 29 euthryoid sera were 4.2 and 18.9 ng/liter, respectively, in close agreement with accepted values. Correlation coefficients for the two compounds were 0.99 and 0.97, respectively, when this procedure was compared with a method involving tracer dialysis and radioimmunoassay. A chromatographic peak was seen for free 3,3',5'-triiodothyronine in the analyses of two of eight hyperthyroid sera, and, with a larger sample volume, from a euthyroid serum. The new method is a potential reference and research procedure for analysis of free iodothyronines.


Column cation-exchange separation of melanin-related metabolites in  urine from cases of melanoma. We describe recent developments in the use of a stable free radical, diphenylpicrylhydrazyl, as a colorimetric detector of reducing metabolites in melanoma urines. A procedure for buffering aqueous/solvent reagent solutions is presented, and examples of the baseline stability achieved for reference chromatograms and urine samples are provided. Chromatograms of phaeomelanin precursors and of an extract of a highly pigmented hamster melanoma are also presented. Identities are tentatively assigned for some of the chromatographic peaks that have previously been correlated with disease, including isomers of cysteinyldopa, and observations of new pigment- and tumor-related metabolites in the chromatograms are noted.


Quantitative analysis of biological marker synthesis in tumor cell cycle. A quantitative relationship between tumor cell number and biologic marker concentration has been investigated and characterized by the previously developed discrete-time kinetic model for the study of cell kinetics. Here, this model is further expanded to cope with both cell cycle kinetics and biologic marker synthesis. A synchronized tumor-cell population is examined to determine the time course of the synthesis of markers in relation to cell cycle. The DNA content distributions, measured by flow microfluorometry, are analyzed by use of the model, and the cell age distribution is extracted. The average marker content per cell in cell cycle is measured for each time sequence in synchronized cell populations. The model, incorporating the cell age distribution and the average marker content per cell in cell cycle, enables one to generate the marker content distribution, from which the cell number is estimated from the marker concentration. The model performance is further evaluated with Chinese hamster ovary cells, and their polyamine content and the total polyamine concentration during synchronization is calculated and related to the total cell number.


Automated zone electrophoresis--experiments and new concepts. I have investigated various modalities of automation of zone electrophoresis. One system has already been previously described (U.S. Pat. No. 3,896,021). Other systems investigated can be divided into batch systems and one random-access system; the former involve separation on cellulose acetate that is supported on 0.127 mm thick polyester (Mylar) film in the form of tape, cards, or discs. Systems in which the separation is in a direction transverse to the long axis of the tape use a typical tape width of 7.5 cm; systems in which separation is longitudinal make use of supports of various widths, depending upon the assay rate desired. Concepts were also developed for a random-access systems for automated electrophoresis, which requires no start-up time. Small Lucite cassettes are used, one for each sample. Each cassette has one surface of either cellulose acetate or any of several gels used for electrophoretic separation. There are further small wells for sample and calibrator. The loaded cassette is inserted into an input queue that allows serial processing. The cassettes move sequentially through prewetting (if needed), sample application, electrophoretic separation, staining, and scanning. This system should also be suitable for automated isoelectric focusing.


Microchemical analytical techniques of potential clinical interest. Microchemical techniques with the capability of single-cell analysis will become increasingly important in clinical laboratory practice. One of the current moves underway in this direction is determination of enzyme activities of cells by microscale spectrophotometry and spectrophotofluorometry for prenatal diagnosis of inherited enzyme deficiencies. Three less-common microanalytical techniques are considered here that are of potential interest in laboratory medicine. The first is dilatometry, which provides a means for enzyme or substrate assay involving measurement of the change in volume or density accompanying chemical reaction in solution. In this connection, the measurement of specific gravity itself to obtain certain chemical information is also of interest. The second of these techniques is the use of spectrophotometry to measure oxygen uptake for functional assays of cells. The third is the use of luminometry in a general system of analysis for determination of many important biochemical substances and activities. Each of these techniques can be used for microscale analysis without sacrifice of precision or accuracy; each is relatively simple, instrumentally ant technically, and could be automated.


Quantitative assays of enzyme activity in single cells: early prenatal diagnosis of genetic disorders. The combined use of special cell culture techniques and biochemical ultramicromethods permits one to handle very small amounts of materials, to reduce the costs of chemicals, and more accurately to assess gene dosage effects by expressing enzyme activities per cell instead of per total cell protein. An alkaline phosphatase induction test has been developed which allows one to screen small numbers of fibroblasts for lysosomal storage diseases, cystic fibrosis, and chromosomal disorders. A successful attempt has been made to automate the microtechniques. Combining the alkaline phosphatase induction with the ultramicro automatization should eventually permit one to screen all pregnancies for major possible fetal genetic defects. Automated ultramicro enzyme assays should contribute to the general development of clinical chemistry.


Development of instrumentation and fluorochromes for automated multiparameter analysis of cells. We have developed and interfaced to a computer an automated instrument (the AMAC III) which is designed to observe simultaneously several physical parameters of cells. Typical parameters include electronic cell volume (Coulter effect), RF amplitude (opacity), multiwavelength fluorescence of cytological stains, and cell light-scattering. The use of a new ultraviolet laser combined with a holographic grating spectrograph promises to increase the number of fluorescing species that can be detected simultaneously. This number can be further increased by use of special rare-earth-based fluorochromes, that emit well-defined, spectrally distinct peaks.


Hemoglobinometry: A comparison between the hemiglobincyanide method and the Coulter S counter. The relative accuracy and precision of the Coulter S Counter have been evaluated in comparison with manual hemiglobincyanide determination according to the recommendations of the International Committee for Standardization in Hematology. Some improvements in the manual procedure, such as centrifugation of hemiglobincyanide solutions and the use of the detergent Triton X-100, were also tested. The Coulter S Counter generally gives higher precision in comparison with the manual method. Nevertheles, Coulter S determinations are systematically lower due to both constant and proportional errors. The available data ranged between hemoglobin values of 11.5 and 18.5%, giving differences of 0-8% between hemoglobin values determined by the Coulter S Counter and the hemiglobincyanide method.


Sweat testing for cystic fibrosis: characteristics of a combination chloride ion-selective electrode. Filling solution leakage, reproducibility, stability, interferences and temperature effects have been studied in relation to the use of the Orion 96-17-01 combination chloride ion-selective electrode in sweat testing for cystic fibrosis. While stability and reproducibility is good, certain antiseptic systems and especially Hibitaine (chlorhexidine gluconate) interfere with the electrode and therefore need to be absent during sweat testing. Temperature conditions during calibration and sweat testing need to be controlled in view of the extent of response variations for even modest temperature differences between sensor-skin interface and electrode stem.


A specific direct radioimmunoassay for oestriol-16alpha-glucuronide in pregnancy plasma. A specific radioimmunoassay has been developed for measuring oestriol-16alpha glucuronide in pregnancy plasma using a highly specific antiserum. The specificity of this antiserum has been assessed by the 50% displacement method and by measuring oestriol-16alpha-glucuronide concentrations in pregnancy plasma samples, both with and without chromatography. The antiserum was found to have Ka of 1.3 X 10(10) M-1. The assay had a sensitivity of 5 pg (least quantity of oestriol-16alpha-glucuronide distinguishable from the zero point, p less than 0.05), an intra-assay variation of 6.07% and an inter-assay variation of 3.36%. The assay was used to measure plasma oestriol-16alpha-glucuronide concentrations throughout eight pregnancies, five of which were normal and three had some defined abnormality.


Digoxin radioimmunoassay: a comparison of the assay performances using tritiated and 125I radioiodinated tracers. The preparation of 125I-labelled tracer for digoxin radioimmunoassay (125I monoiodinated 3-succinyl digoxigenin-1-tyrosine) is described, and its performance in radioimmunoassay of plasma samples is compared with that obtained with tritiated digoxin. The accuracy levels were assessed through the evaluation of different potential sources of systematic errors, such as interference from digoxin-related molecules and plasma proteins and methodological artefacts possibly associated with the immunocomplex instability, and through a series of checks including the recovery and parallelism tests and the correspondence of results obtained with the two tracers. The slope and the repeatability with time of the calibration curves and the spread of replicate estimates were taken into consideration to assess the assay precision. An essential equivalence in terms of reliability of measurement was proved for the two methodological variants, so that practical aspects and economic factors remain the main criteria to evaluate the relative merits: from this point of view, the advantages of using 125I-labelled tracer, as an alternative to tritiated digoxin, are discussed.


Lipoprotein composition in hypothyroidism. Sixteen patients with hypothyroidism have had their lipid status assessed before and during replacement therapy. More than 60% had hypercholesterolaemia and more than 60% had hypertriglyceridaemia. Significant reductions in plasma cholesterol, but not in plasma triglyceride, were seen during replacement therapy. A high cholesterol: triglyceride ratio was observed in VLDL and this relationship tended back to normal during treatment. This raises the possibility that in hypothyroidism, as in Type III hyperlipoproteinaemia, an abnormality in VLDL conversion to LDL is present.


Starch gel electrophoresis for galactose-1-phosphate uridylyl-transferase applied to dried filter paper blood specimens. Starch gel electrophoresis of galactose-1-phosphate uridylyl transferase has been adapted for use on dried filter paper blood specimens submitted for the purposes of routine newborn screening for galactosemia and other inborn errors of metabolism. Selected for study were those specimens with reduced transferase activity, as determined by the Beutler enzyme spot screening test. Clinically benign low activity enzyme variants were readily identified, thus reducing significantly the number of requested additional blood specimens. Transferase-deficient specimens with potential clinical significance had too little activity for transferase visualization and thus could be separated from the benign variants. This technique would facilitate routine newborn screening for galactosemia.


Cholesterol side-chain cleavage enzyme activity and cytochrome P-450 content in adrenal mitochondria of a patient with congenital lipoid adrenal hyperplasia (Prader disease). An autopsied case with congenital lipoid adrenal hyperplasia (Prader disease) was presented. The cholesterol side-chain cleavage (SCC) enzyme activity in adrenal mitochondria of this case was assayed with [3H]cholesterol as substrate, combined with purified bovine adrenodoxin and adrenodoxin reductase, by measuring the amount of [3H]pregnenolone formed. The cytochrome P-450 content was also measured by recording the difference absorption spectra of carbon monoxide-complexed P-450. The cholesterol SCC enzyme activity in adrenal mitochondria of Prader disease was 0.81 nmol pregnenolone/nmol P-450 per min, which was approximately 10% of that in normal tissue. The content of cytochrome P-450 was 0.074 nmol/mg protein, which was about half of that in controls. These results indicate that there is a cholesterol SCC enzyme deficiency in adrenal mitochondria in this disease.


Evaluation of a rapid gas-chromatographic method for the simultaneous quantitative determination of ethosuximide, phenyletheylmalonediamide, carbamazepine, phenobarbital, primidone and diphenylhydantoin in human serum. A simple and rapid gas chromatographic method for the simultaneous estimation of the anticonvulsant drugs ethosuximide, carbamazepine, phenobarbital, primidone, diphenylhydantoin and the metabolite PEMA in serum is presented. The method is based on a simple ether extraction of 1 ml serum before and after precipitation of the proteins by ammonium sulfate and injection of the extract dissolved in methanol without derivative formation. Gas chromatographic separation is performed on a highly polar acidic phase (SP 1000, a terephthalic acid modified Carbowax 20 M), for detection the instrument is equipped with a nitrogen selective detector, quantitation is performed by automatic electronic integration of peak areas in relation to the internal standard Mesantoin. The optimal approach to the gas chromatographic analysis of "problem drugs" like carbamazepine and phenobarbital is discussed, various stationary phases and support materials are compared for effectiveness with this method. In the analysis of over 800 routine serum samples as well as internal and external quality control samples this method was found to be reliable and the results reproducible.


Carbohydrate content of human red cell membrane in patients with cirrhosis of the liver. The protein and carbohydrate contents of red cell membranes from 12 patients with liver cirrhosis were compared to those from 12 normal donors. Protein content was significantly higher and surface sialic acid and neutral hexoses were similar, whereas surface fucose and hexosamine were significantly lower in the cirrhotic red cells. The role of these membrane modifications is discussed.


The nature and origin of hyperamylasemia following open-heart surgery with extracorporeal circulation. The nature of the postoperative hyperamylasemia in 27 patients undergoing open-heart surgery was investigated. An increase in serum amylase activity was found in 56% of the patients. Isoamylase analysis revealed that the rise was in the salivary-type isoamylase in all of these patients. Since the level of serum amylase activity was increased in the postoperative state with prolongation of extracorporeal circulation, it is conceivable that cellular hypoxia due to inadequate tissue perfusion may cause disturbances in cellular metabolism with a release of intracellular amylase. The finding of the salivary-type amylase in normal lung tissue, transient salivary-type hyperamylasemia in acute respiratory distress and increased amylase activity of the salivary-type in serum specimens from the left atrium compared to those from the right ventricle suggest that the origin of the amylase responsible for the transient postoperative hyperamylasemia in the salivary-type is due to the amylase released from lung tissues under hypoxia during and after operation.


Endogenous phosphorylation of membrane proteins in normal and in hereditary spherocytosis erythrocytes. The phosphorylation state of the proteins in hereditary spherocytosis erythrocyte membranes, incubated in the presence of [gamma-32P]ATP, appears to be different from that in normal ones. This is indicated by the finding that in the two types of erythrocyte membranes the ratios between the 32P-labeling of their phosphorylserine and phosphorylthreonine residues were different.


A simple, rapid fluorimetric assay of amoxycillin in plasma. A method for estimation of amoxycillin in plasma is described, based on the formation of a fluorescent derivative which is measured in the presence of 2-methoxyethanol. Drugs commonly administered together with amoxycillin do not appear to interfere with the assay. Data on the sensitivity, accuracy and linearity of the assay are presented together with a comparison with the microbiological assay.


Evaluation of metabolic pathway activity in cultured skin fibroblasts and blood leukocytes. Screening for a variety of blocked catabolic mutants can be achieved in cultured skin fibroblasts and in peripheral blood leukocytes with a simple radioisotope method that is reliable and convenient. The method measures the incorporation into trichloroacetic acid (TCA) insoluble macromolecules of a 14C-labelled intermediate in the pathway under question; incorporation of a 3H-labelled metabolite, not in the same pathway, is used as an internal control of metabolism in the cell population. The 14C/3H incorporation ratio is decreased in blocked pathways; use of the ratio method eliminates the delay required by radioautography (used in earlier adaptations of this method), the problems involved in CO2 collection, and the need to standardize cultures for cell number. This method has been used to identify cells with biochemical lesions in the oxidation of propionate, galactose, hypoxanthine and pyruvate; it has allowed us to identify a new variant of methylmalonicaciduria; we believe it can be extended to include other metabolites and pathways.


(2-Ethoxyethoxy)acetic acid: an unusual compound found in the gas chromatographic analysis of urinary organic acids. An unknown acidic compound was detected in a number of urine samples from patients with a suspected metabolic disorder and some patients treated with chemotherapy. The structure of this compound has been characterized as (2-ethoxyethoxy)acetic acid, using a gas chromatography/mass spectrometry/computer system. The authentic compound was synthesized and compared with the unknown. Urinary (2-ethoxyethoxy)acetic acid is assumed to be formed endogenously from an exogenous precursor, probably 2-(2-ethoxyethoxy)ethanol.


The quality control of alkaline phosphatase determinations with placental phosphatase. Human placenta has been recommended as the source of the alkaline phosphatase used for the preparation of control or reference materials. The effect of certain inhibitors, which may be present in the reagents, on control materials containing the placental isoenzyme, is shown to differ significantly from their effect on the isoenzymes in patient's sera. This finding indicates that if control materials are used which contain only human placental alkaline phosphatase, changes in accuracy resulting from differences in reagent quality may be missed, or alternatively a change in accuracy may be indicated by the quality control results which does not apply to the patient's sera.


Gonadotrophin release in ovariectomized patients. I. Suppression by clomiphene or low doses of ethinyl oestradiol. Administration of clomiphene citrate (150 mg/day) for 5 days to twenty-four ovariectomized patients and seven normal female patients evoked a significant release of FSH and LH in the normal control group and suppressed the gonadotrophin secretion in the castrated patients. A similar suppressive effect on gonadotrophin secretion was noted in eight ovariectomized patients treated for 10 days with low doses (50 microgram/day) of ethinyl oestradiol. It is suggested that in the ovariectomized hypoestrogenic patients, clomiphene acted as an oestrogen, suppressing by a negative feedback action gonadotrophin release in a way similar to ethinyl oestradiol. In the normal control group with an adequate steroid environment, clomiphene acted (probably at the hypothalamic level) as an oestrogen antagonist and stimulated gonadotrophin secretion. In view of our findings, it seems as if the ability of anovulatory patients to respond to clomiphene treatment by increased gonadotrophin secretion depends upon the absolute concentration of the compound in the different organs and by the quantitative relation of clomiphene to the endogenous oestrogens.


The hormone response to a synthetic androgen (mesterolone) in oligospermia. Forty subfertile men with oligospermia were treated with a synthetic androgen (Mesterolone). The effect of the drug was evaluated by measuring serum testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and analysing the semen before and after treatment. The results demonstrated that in twenty-three patients treated for 6-9 months there was a significant decrease in serum testosterone (P less than 0.01); the means +/- SEM before and after treatment were 17.05 +/- 0.95 and 14.7 +/- 0.95 (nmol/l serum) respectively. There was a pronounced increase in serum LH (P less than 0.01), the values being 2.73 +/- 0.26 and 3.61 +/- 0.3 (u/l) respectively. However, no significant difference was found in serum FSH before and after treatment. The sperm concentration showed a variable response to treatment. In twenty-one patients there was either no change or worsening in the sperm concentration, whereas in nineteen patients an improvement was observed. The analysis of variance of sperm concentration and motility for the periods before and after treatment, for all the patients, showed no significant difference in the sperm concentration F1.145 = 2.82 (P=0.1).


Thyroid hormone levels and protein binding in patients on long-term diphenylhydantoin treatment. The effect of long-term diphenylhydantoin (DPH) treatment on thyroid hormone concentrations and protein binding was determined in a randomized controlled trial. As has been demonstrated previously, total thyroxine (T4) concentrations were significantly depressed in patients on DPH. There was no significant effect on indirect indices of protein binding of thyroid hormones, and the free thyroxine index (FTI) was also significantly depressed. Triiodothyronine (T3) and thyrotrophin (TSH) concentrations were either unaffected, or only very slightly affected by DPH. Significant effects on the FTI were still apparent 4 weeks after discontinuing treatment. It is concluded that the depression of total T4 levels observed in vivo is not due solely to diminished protein binding, but may instead be largely explained by reports suggesting enhanced degradation of T4 following DPH therapy.


Vasovagal hypotension and vasopressin release. Mild vasovagal hypotension occurred in two normal male volunteers during insertion of indwelling venous cannulae. In spite of a rapid intravenous fluid load (3.6-4.6 litres in 90 min) both subjects passed little urine for 100 min. When the experiment was repeated without vasovagal hypotension, a rapid large diuresis followed the fluid load. The prolonged oliguria after vasovagal hypotension was the result of vasopressin release. This was demonstrated by measuring vasopressin in the blood and urine and by observing the renal response to a water load. The observation in man that a mild transient hypotensive episode may reduce urine flow for 100 min has clinical significance.


The effect of isoprenaline on plasma renin activity in man: a dose-response curve. Four normal subjects on a free sodium intake received intravenous isoprenaline in doses of 2, 4, 8 and 16 microgram over 2 min. Three of the subjects received a second infusion of 8 microgram. The rate of renin release indexed by changes in plasma renin activity increased in all subjects at each dose level. The mean peak levels of plasma renin were 9%, 29% and 77% above the mean control levels at doses of 2, 4 and 8 microgram respectively. The response of 16 microgram was no different from that seen with 8 microgram. The renin response obtained at 8 microgram was highly reproducible such that the coefficient of variation for duplicate estimations of plasma renin (twelve duplicates) ranged from 1.7 to 4%.


A study of complement fixation by rheumatoid factor using a haemolytic assay system. Complement fixation by rheumatoid factor (RF) in sera from rheumatoid arthritis patients has been investigated by means of a haemolytic assay system employing sheep erythrocytes (SRBC) coated with reduced and alkylated rabbit IgG anti-SRBC antibody. Haemolysis was almost invariably detected with RF-positive sera whereas haemolysis was not observed with RF-negative sera; It was evident from a marked increase in haemolysis, obtained following isolation of IgM-RF of high purity from several RF-positive sera, that the full in vitro complement-fixing ability and hence lytic potential of RF in serum is masked. Parallel observations were also made with synovial fluids. The inhibition of haemolysis by RF in sera and synovial fluids commonly involved a reduction in degree of lysis at high concentration of test material as well as a more generalized inhibition in overall percentage lysis. Complete replication of typical RF-positive serum and synovial fluid patterns of lysis on dilution was achieved by addition of heat-aggregated human IgG to isolated IgM-RF preparations and demonstrated that the two inhibitory effects are separable in terms of complement depletion and reduction of free rheumatoid factor antibody activity, respectively.


Quantitative relationships between IgE antibody and blocking antibodies specific for antigen E in patients given immunotherapy with ragweed antigen E. Total antibody binding of ragweed antigen E (AgE) and IgE antibody of AgE were quantitatively measured in serum from eleven patients given immunotherapy with purified AgE. From these data the contribution of antibody other than IgE, presumed to be mostly IgG, to total AgE binding could be determined. Binding of AgE by antibody other than IgE antibody was considered to be due to blocking antibody. As immunotherapy progressed, IgG antibody binding of AgE and the IgG/IgE binding ratio were serially determined. IgG antibody binding of AgE increased from a pretreatment mean of 238 ng AgE bound/ml to 3142 ng AgE bound/ml just prior to the first ragweed season and reached a peak of 4286 ng AgE-bound/ml. Although blocking antibody thus increased progressively with treatment it was not correlated significantly with symptom scores. The IgG/IgE binding ratio increased from a pretreatment mean of 19-290 just prior to the first ragweed season and reached a peak of 1167. This ratio was related significantly to symptom scores reported by patients during the ragweed season subsequent to immunotherapy.


Purification of normal human eosinophils using the different binding capacities of blood leucocytes for complexed rabbit IgG. A method has been developed for separating eosinophils from other types of leucocyte in normal individuals. Erythrocytes are sedimented with dextran, and mononuclear cells are removed on an isotonic density gradient of ficoll and sodium diatrizoate. The eosinophils and neutrophils are then washed and sedimented onto plastic petri dishes coated with human IgG and rabbit anti-human IgG antibody; As neutrophils and monocytes have Fc-binding sites for complexed rabbit IgG they attach to the dishes, and the unabsorbed normal eosinophils which lack this binding site are eluted in a purified suspension. The mean purity of the eosinophils obtained in this way was 70%, range 50-90%, and the mean yield was 49%, range 21-81%. This method provides purified eosinophils from normal people without subjecting them to osmotic or plasma membrane stimulation. Normal eosinophils which are prepared in this way are particularly suitable for studying the ways in which eosinophils became altered in disease states.


Immunological studies of patients with asbestosis. I. Studies of cell-mediated immunity. A variety of cancers have been documented in patients exposed to asbestos dust. Since a deranged immune system may play a rôle in cancer development, the general level of immunocompetence was studied in a group of twenty-six patients with radiographically defined asbestosis, who might be at risk of developing asbestos-related neoplasms. Statistical comparisons were made with a comparable control group. A disproportionate number of the patients displayed cutaneous energy to certain recall antigens and to 2,4-dinitrochlorobenzene. In vitro studies of cellular immunity, as evaluated by phytohaemagglutinin-induced proliferative and cytotoxicity assays,  showed significantly lower values amongst the patient group. Serum inhibitors of mitogen-induced lymphocyte transformation were also detected in several of the patients. The possible significance of these findings is discussed.


The genetic contribution of the NZB mouse to the renal disease of the NZB x NZW hybrid. The occurrence of lupus nephritis in (NZB x NZW)F1 mice appears to depend on the action of at least two dominant or co-dominant genes (at least one gene from each parent) as neither of the inbred parental strains shows the disorder. Identifying affected animals by antemortem determinations of renal function, using improved methods of measuring proteinuria and renal clearance, we have studied the incidence of the renal disease in 230 (NZB x NZW)F1 x NZW backcross mice. The incidence was 49-6% which indicates that NZB strain contributes only one gene, or cluster of closely linked genes, to the renal disorder of the F1 hybrid. The gene(s) must be dominant or co-dominant, as it expresses its effect in the heterozygous state. Study of the H-2 status of the backcross mice showed a loose linkage of the NZB renal disease gene(s) to the D end of the H-2 complex, the crossover frequency being 32-6+/-3-1%.


Increased serum IgD concentrations in patients with Hodgkin's disease. Serum IgD concentrations have been determined in twenty-one patients with Hodgkin's disease, in eight patients with non-Hodgkin's lymphomas and in twenty-eight normal (control) individuals by both a solidphase radio-immuno-assay and radial-immunodiffusion. Fourteen of the Hodgkin's patients displayed three to forty-five-fold increased serum IgD levels as compared to control individuals, while in the remaining seven patients IgD concentrations were practically normal. Patients with non-Hodgkin's lymphomas had decreased IgD concentrations.


Lactic acidosis.

Lactic acidosis. Lactic acid is generated as the end product of anaerobic metabolism of glucose and is disposed by gluconeogenesis or oxidation. Changes in the lactate pyruvate ratio are not necessarily indicative of tissue hypoxia. The plasma lactate concentration is the result of lactate production and lactate removal (hepatic and renal gluconeogenesis; oxidation by muscle, liver and kidney). Lactic acidosis is defined as a state of metabolic acidosis (arterial pH less than 7.3) due to an increase in the blood concentration of lactate (greater than 2 mEq/l). Lactic acidosis may occur with evidence of tissue hypoxemia (type A) or in its absence (type B). Lactic acidosis has been described in association with phenformin therapy, hereditary enzymatic defects, hematological malignancy, prolonged fasting, shock with or without septicemia and occasionally without any underlying disease ("idiopathic" lactic acidosis). The therapy of lactic acidosis consists of administration of sodium bicarbonate and restoration of adequate tissue perfusion; hemodialysis may be helpful to control sodium excess and possibly to remove phenformin. The effectiveness of methylene blue, glucose and insulin are not yet established.


Renal function after high-dose urography in patients with chronic renal insufficiency. Renal function was assessed by frequent recordings of Ccr and serum creatinine in 22 patients with chronic renal failure before and after high-dose urography. Urography was followed by a significant, moderate and transient decrease in Ccr which was maximal on the second day; at the same time a significant increase in serum creatinine was observed which was maximal on the fourth day after urography. In all but two patients, Ccr and serum creatinine returned to pre-urographic levels within the next two weeks. Possible causes of the deleterious effects of the contrast media on the kidneys are discussed.


Quadriceps tendon ruptures in uremia. Treatment with surgery and 1alpha-hydroxycholecalciferol. Three young patients with chronic renal failure, one on regular hemodialysis, suffered bilateral quadriceps tendon ruptures. All three had uncontrolled, severe osteitis fibrosa. In two, aluminium hydroxide failed to control secondary hyperparathyroidism, while 1alpha-hydroxycholecalciferol (1alphaOHD3) given after the injury resulted in rapid resolution of the hyperparathyroidism. Prevention of tendon ruptures in uremia depends on effective control of secondary hyperparathyroidism. Treatment should involve prompt surgical repair and reversal of the osteitis fibrosa with an effective vitamin D metabolite such as 1alphaOHD3.


Renal failure in Burkitt's lymphoma.

Renal failure in Burkitt's lymphoma. A case of Burkitt's lymphoma with renal failure due to massive infiltration of the kidney is reported. There was a striking initial response to chemotherapy with a parallel improvement in renal function and decrease in renal size. The rare occurrence of renal failure due to lymphomatous infiltration of the kidney parenchyma in the absence of urinary tract obstruction is reviewed.


Thanatophoric dwarfism. Two case reports and survey of the literature. Thanatophoric dwarfism is a severe form of short-limbed dwarfism in which cardiorespiratory failure uniformly results in death in the neonatal period. Its radiographic features include markedly flattened vertebral bodies with a typical U-shaped deformity, a flat squat pelvis, and short, bowed extremities with flaring and irregularity of the metaphyses. These characteristic features distinguish this entity from the two other most commonly confused congenital short-limbed forms of dwarism--achondroplasia and achondrogenesis. The distinctions are discussed in the text.


Antibiotic-associated colitis.

Antibiotic-associated colitis. Among 26,294 hospitalized patients monitored by the Boston Collaborative Drug Surveillance Program (BCDSP), 8,948 (34%) received at least one antibiotic, and none were diagnosed as having drug-induced colitis to in-hospital antibiotic exposure. Seven patients who had taken antibiotics as outpatients, however, were admitted with antibiotic-associated colitis. Six of these patients had taken lincomycin prior to the onset of symptoms; one had taken ampicillin. Six of the patients were hospitalized at a New Zealand hospital and one at a hospital in Canada. The five patients with lincomycin-associated colitis at the New Zealand hospital were admitted over an 11-month period. Severe colitis due to antibiotics has been a rare event in the BCDSP experience, especially in the United States.


Enhancement by food of canrenone bioavailability from spironolactone. The influence of food intake on the bioavailability of canrenone, the major and active metabolite of spironolactone, was explored in 8 healthy male volunteers. Spironolactone was administered as a single oral dose of 100 mg, both in the fasting state and together with a standardized breakfast. Numerous venous blood samples were taken from 30 min to 96 hr after ingestion of the drug, and the plasma concentrations of canrenone were determined by spectrofluorometry. The results indicate that more canrenone enters the general circulation when spironolactone in ingested together with a meal.


Enhancement of hydralazine bioavailability by food. The influence of food on the bioavailability of hydralazine in noncoated and coated tablets was examined in 5 healthy males. Each subject received an oral 50-mg dose on four different occasions: two 25-mg noncoated tablets with and without food and one 50-mg coated tablet with and without food. The meal was a standardized breakfast of 440 calories. Venous blood samples were obtained during a 6-hr period, and the plasma concentrations of unmetabolized hydralazine were assessed by a selective and sensitive gas chromatographic method. The results indicate that food enhances the bioavailability of hydralazine 2- to 3-fold both when noncoated and coated tablets are used.


Enhancement of the bioavailability of propranolol and metoprolol by food. The possible influence of food intake on the bioavailability of one nonselective and one cardioselective beta adrenoceptor antagonist, propranolol and metoprolol, was examined by serial determinations of the drug concentrations in blood of healthy subjects, taking single doses of the drugs both on an empty stomach and together with a standardized breakfast. The results indicate that food enhances the bioavailability of both propranolol and metoprolol. They also confirm that there is extensive interindividual variation in the bioavailability of these drugs.


Digoxin toxicity in patients with normokalemic potassium depletion. Reviews of large series of patients with digitalis-induced arrhythmias create a seeming paradox: Hypokalemia is infrequently associated with digitalis-induced arrhythmias but the clinical benefit of supplementation of potassium for most digitalis-induced arrhythmias is obvious. Examination of the electrophysiologic abnormalities induced by digitalis coupled with the electrophysiologic effects dependent on the ratio intracellular to extracellular concentrations of potassium clarifies the issue. We present evidence that supports additive effects of the toxicity of digitalis and abnormal ratios of concentrations of potassium inside and outside the cardiac cell. We provide guidelines for assessing this crucial ratio of intracellular to extracellular concentrations of potassium to aid the clinician in the diagnosis and effective treatment of digitalis-induced arrhythmias.


Linear dose response and quantitative attenuation by potassium of the inotropic action of acetylstrophanthidin. To evaluate the nature of the inotropic dose response of digitalis and to determine the effects of potassium on this response, isometrically contracting isolated supported right ventricular cat papillary muscles were studied relative to their peak tension and peak dT/dt increases to physiologic cumulative doses of acetylstrophanthidin (ACS) in different extracellular potassium concentrations in the muscle bath. The inotropic dose response to ACS was observed to be linear in cumulative glycoside concentrations ranging from 0.40 to 4.23 X 10(-7) M ACS in 3.5 mM K+ medium and from 1.22 to 7.47 X 10(-7) M ACS in 7.0 mM K+ medium. The influence of potassium alterations in the muscle bath from the low to the high K+ concentrations prior to ACS resulted in marked attenuation of the positive inotropic property of ACS. From these data, it is concluded that the dose inotropic response of digitalis is linear, with small doses producing proportionally the same effects as larger doses, and that extracellular potassium markedly influences this linear dose response such that higher K+ concentrations considerably attenuate the positive inotropic response of digitalis.


Response optimization of drug dosage: antiarrhythmic studies with tocainide. The benefits of using antiarrhythmic response to optimize dosage regimens of antiarrhythmic drugs in individual patients have been examined. Graded antiarrhythmic response and simultaneously measured plasma drug concentrations have been obtained in 15 patients receiving multiple oral doses of a new antiarrhythmic, tocainide. Plasma drug concentration-antiarrhythmic response data from each of 11 subjects responding to the drug have been fitted by a generalized concentration effect function which is valid over the entire range of response. With the use of experimentally determined pharmacokinetic parameters to define the dose-plasma concentration relationship and plasma drug concentration-response parameters estimated for individual patients, simulations were carried out to show the effect of various dosage regimens on antiarrhythmic response in individual patients. Such simulations provide a means of assessing antiarrhythmic effect in the range of clinical interest (80% to 100% of maximum effect), where the antiarrhythmic effect is a nonlinear function of dose, plasma drug concentration, or their logarithms. The simulations also demonstrate that for identical daily doses and dosing intervals patients show marked variability in antiarrhythmic response.


Cumulation of N-acetylprocainamide, an active metabolite of procainamide, in patients with impaired renal function. N-Acetylprocainamide (NAPA) accumulated in the plasma of 6 cardiac patients with renal failure taking procainamide chronically for therapy (4 were undergoing hemodialysis) and contributed to the therapeutic and toxic effects of the procainamide. NAPA plasma levels ranged from 14.0 to 28.0 microgram/ml 3 hr after a dose of procainamide which is well above the 3-hr NAPA plasma levels of nonazotemic cardiac patients (range 1.9 to 6.3 microgram/ml; p = 0.002) on larger doses of procainamide. There was almost no decline in NAPA plasma levels on interdialysis days. In one of the patients with renal failure NAPA was still present 15 days (13.8 microgram/ml) and 38 days (0.9 microgram/ml) after procainamide was stopped, indicating a half-life of several days. Measurement of procainamide plasma concentrations by the usual fluorometric or colorimetric methods does not detect NAPA. Since NAPA accumulates in patients with impaired renal function, the concentrations of both this active metabolite and procainamide should be determined in these patients if drug level monitoring is to be helpful.


Elimination of furosemide in healthy subjects and in those with renal failure. Furosemide was administered intravenously to 5 healthy volunteers and 15 patients with various degrees of renal failure. Two patients were given the drug orally. The plasma half-life of furosemide averaged 0.79 hr in the healthy subjects. Although most patients with kidney disease had a prolonged half-life (t1/2), up to 24.58 hr, some with advanced renal failure had an almost normal t1/2. The plasma clearance of furosemide, which in the normal subjects averaged 194 ml/min, decreased proportionally with decreasing creatinine clearance, as did the renal clearance, which in the healthy subjects averaged 95 ml/min. There was no correlation between kidney function and the apparent volume of distribution or of nonrenal clearance. One patient was given 35S-labeled furosemide intravenously. Although the furosemide plasma t1/2 was essentially normal, the elimination rate of metabolites was decreased. Unlike that of healthy subjects, the main route of excretion of label was in the feces.


Effects of prazosin on forearm resistance and capacitance vessels. The effects of oral prazosin on the peripheral circulation were evaluated in 10 subjects, including 7 patients with chronic congestive failure due to coronary heart disease. To achieve this purpose the actions of 30 to 50 micrograms/kg body weight prazosin were assessed on both the forearm arteriolar and venous beds simultaneously with the use of the limb plethysmographic technique. Prazosin produced marked decline of forearm venous tone (FVT) from 44.5 +/- 12.3 to 14.3 +/- 3.1 mm Hg/ml (p less than 0.01) concomitant with marked decrease in forearm vascular resistance (FVR) from 70.2 +/- 11.4 to 48.4 +/- 4.9 mm Hg/ml/100 gm/min (p less than 0.05) which persisted for at least 60 mins without change in heart rate. These findings, demonstrating that prazosin induces systemic venodilation and peripheral arteriolodilation, indicate potential benefits of the oral drug for relief of pulmonary congestion and elevations of cardiac output in patients with chronic congestive heart failure.


Physiologic disposition of nabilone, a cannabinol derivative, in man. Nabilone is a cannabinoid that is being evaluated in man as a potentially useful psychoactive drug. We found that nabilone was readily absorbed from the human gastrointestinal tract when administered orally as a coprecipitate with polyvinyl-pyrrolidone. The absorbed drug disappeared from plasma rather rapidly (half-life, approximately 2 hr), evidently due to extensive tissue distribution and rapid metabolism. The metabolites of nabilone persist in plasma for extended periods (half-life of total radioactivity exceeds 20 hr). Circulating metabolites include isomeric carbinols formed by reduction of the ketone in the 9-position of nabilone. Nabilone is eliminated in feces (about 65% of dose) and urine (20%). The excretory products in urine have not been identified, but metabolites that are labile to hydrolysis by beta-glucuronidase or sulfatase do not appear to be formed in significant amounts. A metabolite of nabilone in feces has been identified as a diol formed by reduction of the 9-keto group plus oxidation at the penultimate carbon of the dimethylheptyl side chain. The long duration of action of nabilone in the face of rapid and extensive metabolic elimination suggests that the pharmacologic effects, at least in part, may be exerted by one or more active metabolites.


Cineradiographic assessment of Björk-Shiley aortic and mitral prosthetic heart valves. A non-invasive method for assessment of Björk-Shiley mitral and aortic heart valve movements has been developed. The Björk-Shiley tilting disc valve is described and its placement within the heart is explained. Twenty patients have been studied post-operatively with 23 valves, 10 mitral valves and 13 aortic valves, three patients having both. The method of assessment is described and consists of projecting the valve with its opaque disc marker in true profile and en face using the C arm screening system of a C.G.R. Angiorama coronary angiography unit. A cineradiograph is taken and the maximum opening angle of the valve is measured from the projected image directly or calculated from measurements taken from the image. Movement of the valve ring can also be assessed when paraprosthetic leak is suspected. The results of the study show that: (1) This method is simple, non-invasive, requires no preparation and is reproducible. (2) The valve discs open to a smaller angle than expected in most cases, and in only a few cases to 60 degrees or more. (3) It is valuable to record valve function post-operatively so that a comparison can be made later should valve malfunction be suspected. (4) In only one case was it found impossible to assess valve movement because of orientation of the valve within the patient.


Coronary arteriography; method of presentation of the arteriogram report and a scoring system. A coronary arteriographic report presentation consisting of a diagram on which the radiologist draws the coronary arterial anatomy of each individual case is described. The diagram allows a clear visual presentation of all the information gained from the analysis of the original arteriographic study including anatomical variations, the position and importance of each artery in terms of the myocardium it supplies, the sites and severity of obstructions and the presence of collateral pathways. A myocardial scoring system which expresses the severity of left ventricular arterial obstructive disease is also presented. The myocardial score takes into account not only the degree of stenosis of any number of arterial branches, but also their importance in terms of the amount of myocardium supplied.


Posterior urethral valves.

Posterior urethral valves. During the past decade some urologists and radiologists have doubted the existence of posterior urethral valves. It has been suggested that the primary lesion in patients thought to have urethral valves is bladder neck obstruction. During the past seven years we have seen an average of three new cases of posterior urethral valves per annum. In all cases the valves themselves, not the bladder neck, obstructed the urethra. The urologist may miss valves at urethroscopy, but use of the new fibreoptic endoscope has improved his chances of seeing them. Posterior urethral valves may not be demonstrated radiologically if the radiologist does not use a rapid recording device or if the patient does not micturate forcefully during micturating cystourethrography. Failure to detect the valves may lead to an erroneous diagnosis of bladder neck obstruction.


The significance of bone islands, cystic areas and sclerotic areas in dysbaric osteonecrosis. Dysbaric osteonecrosis is a major hazard to compressed air workers and an increasing hazard to divers. Symptomless osteonecrosis is best recognised by radiology and it is of fundamental importance that interpretation be reliable and accurate. There is much controversy concerning the significance of bone islands and cystic areas; several authors report bone islands and cystic areas to be up to eight times more frequent in compressed air workers and divers and believe that these represent positive evidence of osteonecrosis. Skeletal radiographs of 100 Royal Navy divers, all of whom were at risk to osteonecrosis were matched for age and rank with 100 controls, none of whom had been exposed to high pressures. The radiographs were interpreted by three radiologists working independently without knowing whether the radiographs were in the diving or control group. It is concluded that bone islands, cystic areas and sclerotic areas, as described in this text, occur with equal frequency in divers as in the normal population and do not represent positive evidence of osteonecrosis. The report includes autopsy studies of the proximal femur and proximal humerus in six diving fatalities. Five bone islands in the proximal humerus and one in the femoral neck were studied in bones removed from five divers. In the sixth case a cyst was seen to develop radiologically in the femoral neck and then reduce in size over 3 years and 10 months. Slab radiographs and histological section in all cases show no evidence of osteonecrosis.


Cervical vertebrae measurements in syringomyelia. Lateral X-rays of the cervical spine taken under standard conditions in 69 cases of syringomyelia have been measured to assess the relative sizes of the canals and bodies. One hundred and five cases without cervical spine abnormality provided controls. The expected expansion has been observed in males from C5 to C7 and in females from C3 to C7. The oddity that the expansive process seemed to come higher in females than in males has been noted by other workers. In both sexes it has been found that diminution of vertebral body size is a more consistent finding than enlargement of the canals and correlation coefficients have confirmed that enlargement of the canal appears to take place at least in part at the expense of the body. Possible factors in the enlargement are discussed. Oblique measurements taken in 57 syrinx cases and 89 controls showed the expected change caused by the view of the lower cervical vertebrae being closer to AP and pictures of the upper vertebrae being progressively closer to lateral views. There was a tendency for the bigger oblique diameters to occur in these cases with the biggest sagittal diameters and an insignificant tendency for the biggest canals to have a diminished difference between the two oblique measurements. There was no evidence that oblique measurements could be used to detect slight degrees of enlargement in cases of syringomyelia.