Toxicity to bilirubin in neonates: infant development during first year in relation to maximum neonatal serum bilirubin concentration. Neurologic and developmental performance during the first year of life was correlated with maximum neonatal serum bilirubin levels for 27,000 infants in the Collaborative Perinatal Project. The infants were grouped by race and by five birth weight/gestational age categories to control for the effect of these factors on hyperbilirubinemia and developmental outcome. Low mean eight-month motor scores and delayed one-year motor development were associated with serum bilirubin levels in the range of 10 to 14 mg/dl and above. This relationship was strongest for low-birth-weight/short-gestational-period infants. A persistent association of developmental outcome with hyperbilirubinemia was found over and above the variation of maturity within the birth weight/gestational age categories.


Development of anaerobic fecal flora in healthy newborn infants. Stool samples from 196 healthy infants less than ten days of age were cultured to delineate bacterial colonization patterns of the intestine. By one week of age, isolation rates of Bacteroides fragilis and other anaerobic bacteria in term infants following vaginal delivery and formula feeding approach that of adults. Differences in gestational age, type of delivery, and type of feeding are associated with significantly different colonization patterns of anaerobic and aerobic bacteria in the first week after birth.


Quantitative nitrobluetetrazolium reduction by normal newborn monocytes. The phagocytosis-induced metabolic burst of human newborn monocytes, as evaluated by their capacity to reduce NBT, was comparable to that of adult monocytes. The NBT reduction assay constitutes a simple method of ascertaining the functional capacity of human monocytes.


Intrapatient variability in theophylline kinetics. Seven asthmatic children had repeat determinations of theophylline pharmacokinetic measurements over three- to nine-month intervals. Significant intrapatient variability was found in the theophylline clearance and t1/2, which determine the dosage regimen necessary to provide given average, peak, and trough theophylline plasma levels. Repeat clearance values were, on average, 52% different from the original clearances, with a range of -57% to +142%. A single determination of theophylline kinetic measurements in any individual patient cannot be used routinely to predict future theophylline dosage regimens for that patient.


A colobomatous optic disc anomaly and associated retinal detachement. A case is presented of a two-year-old white female with an optic nerve anomaly and an associated retinal detachment. A unilateral colobomatous disc was noted to be surrounded by a chorioretinal pigmentary alteration in the form of an annulus. A clear zone with absence pigmentation ringed the more central gray-black area. The retinal vessels were noted to come directly out of the deeply colobomatous disc area and to run between the cystic convolutions of the adiacent retinal tissue. A surrounding area of retinal detachment extended for a distance of three disc diameters from the disc. This case is one of a few yet reported in the literature.


One hundred consecutive coarctation resections followed from one to thirteen years. The technique of operative repair for coarctation of the aorta is now well standardized and the immediate surgical mortality has been lowered to less than 5% in most large series. Long term follow up, however, is only recently being reported. This paper describes the current status of 100 consecutive patients who underwent elective resection from 1--13 yr ago. There was only one operative death. In contrast with other reports, residual systemic hypertension is rare in the 97 survivors. These observations confirm that coarctation of the aorta can be repaired surgically with an acceptable operative mortality; the outlook of the survivors appears excellent.


Sector shaped membranous cataract.

Sector shaped membranous cataract. A sector shaped membranous defect of the lens is described. Possible causes for the defect are discussed. An injury to a small area of the anterior layer of epithelial cells plus a localized rupture of the capsule occurring between the third and eighth months of development might account for this defect.


Modified Blalock shunts utilizing pericardial tube grafts. In the last decade, 14 patients underwent an aorticpulmonary shunt for cyanotic heart disease, at which time the subclavian artery was either deemed too small or too short to function satisfactorily as a Blalock shunt. In each case a rectangular piece of pericardium was excised, rolled into a tube, and sutured down one edge to create a tube graft. One end of the graft was sutured to the stump of the subclavian artery near its takeoff and the other end was sutured end-to-side to the corresponding pulmonary artery. During the same period, 5 children had azygos vein grafts and 2 had Teflon grafts inserted to create a modified Blalock shunt. This article will discuss the indications, techniques, and long term results of aorticpulmonary shunts of all types, and more specifically the complications and long term results in patients where these grafts were used.


Surgical correction of pectus excavatum. It has been observed that some patients who had correction of funnel chest deformity by methods which failed to provide fixed elevation of the involved sternal segment developed progressive sagging in later years in spite of looking good at the operating table. This has led to the adoption of a new technique of double sternal support. This procedure has resulted in 35 of 37 children (94%) being classified as excellent or satisfactory. This double support was initially established in 1959 by overlapping the upper transsected sternum while maintaining elevation of the lower end with a soft tissue sling of perichondrium and intercostal muscle. Beginning in 1961, a rigid bridge of rib or stainless steel bar was substituted at the lower end of the sternum. This has provided better support and the current preference of using the steel bar has been validated in this group of patients. The few disappointments were related to removal of the bar earlier than desired, failure to excise all the protruding sternal cartilage stumps or rib graft tips and inability to cover the lateral sternal edges with pectoral muscles. If possible, the steel bar should not be removed before 12 mo. When these pitfalls were avoided, the results were almost uniformly excellent. The wisdom of excising all depressed cartilaginous segments, as advocated by Ravitch in 1949, has been substantiated. A submammary transverse incision has provided an excellent cosmetic appearance. The morbidity has been low and the mortality zero. In spite of the absence of objective evidence of cardiopulmonary dysfunction, there seems to be an almost uniform improvement in appearance and in patient activity following successful correction of the funnel chest. The latter may be as much a psychological response as a physiologic one. The low morbidity, satisfactory long term results, and general improvement in the patient's body image and outlook on life indicate the need to offer correction of the severe pectus excavatum deformity to low risk children.


Spiral looping of retinal artery.

Spiral looping of retinal artery. An isolated retinal vascular anomaly in the form of an arterial loop is presented in a 32-year-old male. This loop originated on the retina beyond the optic disc border and returned to the lower branch of the central artery on the retinal tissue after making six spirals. The retinal circulatory dynamics of this eye, defined by fluorescein angiography, was observed over a period of 12 years with no loss of function to the involved eye.


Peripheral uveitis in children.

Peripheral uveitis in children. The treatment of peripheral uveitis in the young patient requires close supervision. Early diagnosis of the inflammation will permit the ophthalmologist versed in the use of local, periocular, and systemic corticosteroid therapy to control the inflammation in these young patients and to preserve their vision. Treatment should be instituted when vision decreases to less than 20/40, and when optic nerve or retinal changes appear to be progressing. The use of general anesthesia in patients less than 14 years of age is necessary when they are treated with periocular injections.


Transtracheal drainage of lung abscesses in children. Experience with three patients with primary lung abscesses indicates that transtracheal catheter drainage of lung abscesses is a safe and beneficial procedure in childhood. The ability to drain abscesses not easily reached percutaneously will promote emptying and collapse of the abscess and provide bacteriological information which will enable the physician to select the correct antibiotics.


Early recognition and aggressive treatment of gastroesophageal reflux following repair of esophageal atresia. Twelve patients with gastroesophageal reflux following repair of esophageal atresia are presented. Reflux produced recurrent stricture, failure to thrive, repeated pneumonitis, and in one patient, respiratory arrest and nearly death. Treatment consists of positional therapy or fundoplication operation both of which seem less successful in this combination of lesions than with GER and a  normal esophagus. There was one death as a late postoperative complication of fundoplication.


The Vogt--Koyanagi--Harada syndrome in children. Two cases of the Vogt--Koyanagi--Harada syndrome in children, a very rare disorder in this age group, are reported; one patient had the chronic diffuse type, and the other had neurologic symptoms and exudative retinal detachments. Various theories of causation of the syndrome have been proposed, including viral infection, sympathetic ophthalmia, and altered immunologic status, but the etiology remains obscure.


Subcutaneous reduction clitoroplasty.

Subcutaneous reduction clitoroplasty. Congenital clitoral hypertrophy should be corrected in infancy. Most surgeons perform a total clitroectomy or one of several kinds of clitoral recession procedures. There are some reasons for dissatisfaction with both of these alternatives. An operation in which the corpora cavernosum are resected subcutaneously and the glans sutured to the pubis preserves blood supply and sensation and results in a perineal appearance close to normal. The author has performed this operation infive cases of clitoral hypertrophy associated with adrenogenital syndrome and suggests a wider trial of procedure.


Intussusception in the 1970s: indications for operation. Eighty-one patients with proven intussusception were treated at the Cincinnati Children's Hospital from 1970-1974. One died. Seven of these had ileo-ileal intussusception, all treated surgically. Seventy-four had colonic components of their intussusceptions. In 58 of these patients (78%), reduction was attempted at barium enema, successfully in 32. Hydrostatic reduction was abandoned and the patient operated upon when the intussusception was not pushed out of the colon, when barium failed to reflux into several loops of ileum, or when there was a large persistent filling defect in the cecum or terminal ileum. Primary operation without barium enema was done in 16 patients. The appearance of intestinal obstruction by abdominal x-ray seemed to give the best warning about the complicated, incarcerated, or gangrenous intussusception. Primary operation is, therefore, advised for the patient with intussusception if there is x-ray evidence of intestinal obstruction. The age of the patient and the duration of his symptoms do not seem important in this regard, except as they correlate with peritonitis or obstruction. For the patient without peritonitis or intestinal obstruction, attempted reduction of the intussusception at barium enema seems safe and effective, regardless of the patient's age or duration of his symptoms.


Traumatic death in urban children.

Traumatic death in urban children. Trauma has remained one of the leading causes of death in children in spite of improved medical care. A review of 911 pediatric trauma deaths which occurred over a 5 yr period in an urban setting revealed that almost 50% of these children died before receiving medical care. A significant improvement of the trauma mortality can thus only be accomplished by reducing the number of "DOAs". We therefore analyzed the cause and type of injury and its relationship to age, sex, race, seasonal occurrence, and sociological circumstances. The following four categories are merely part of the overall material developed in this review. Even with improved medical care of trauma patients the overall pediatric trauma mortality cannot be significantly reduced unless the number of DOAs is decreased through prevention. Educational and family assistance programs can be designed for specific problem areas to reach identified susceptible groups through existing channels such as day care centers, schools, or welfare agencies. Statistical data, such as presented here (but not previously available) are essential to analyze the particular problems of specific geographic and sociologic areas. Since the vast majority of pediatric trauma deaths fall within the interest sphere of the pediatric surgeon, our active participation in accident prevention is essential to achieve a significant reduction of pediatric trauma mortalities.


Radioisotope diagnosis of splenic trauma. Multiple injury or delay in seeking medical attention may prevent confident clinical diagnosis of splenic trauma. The spleen scan is a rapid, simple, noninvasive test useful in such circumstances. When peritoneal lavage is contraindicated, unrevealing, or inapproapriate, radioisotope imaging of the spleen can help confirm a suspicion of splenic injury.


Use of fresh amnion as a burn dressing.

Use of fresh amnion as a burn dressing. Thirty-seven children with second and third degree burns dressed with amnion were compared to seventy-three children treated with Furacin (Eaton Labs, Norwich, N.Y.) dressing. Amnion was found to be as easy to use as Furacin. Fewer split thickness skin grafts were needed in amnion treated children and these patients required fewer days of hospitalization. Bacterial culture data suggests that amnion is as good as and possibly superior to nitrofurazone in decreasing the number of organisms on the burn wound. No adverse reactions to amnion were noted. The use of amnion is supported by this preliminary study and is deserving of further investigation and clinical use.


Composition of amniotic fluid with experimental jejuno-ileal atresia. The possibility that the composition of amniotic fluid is significantly altered with fetal intestinal obstruction was examined in 15 normal, 15 sham operated and 15 ewes in which jejuno-ileal atresia was created by devascularizing a 15 cm intestinal segment in the fetus at 90--100 days gestation. Samples of amniotic fluid for osmolality, urea N, creatinine, electrolytes, amylase, lipase, bilirubin, and proteins were obtained at 100 days gestation and at C-section performed 5 days prior to the anticipated date of delivery. One sham operated and four operated fetuses aborted prior to term for an 83% overall fetal survival rate. All surviving operated animals had total intestinal obstruction with the classical appearance of jejuno-ileal atresia. The volume of amniotic fluid at term varied from gelatinous material to as much as 1.0 liter of clear yellow to dark orange fluid. Amniotic fluid composition in term animals was not significantly different from those at 100 days gestation when the creatinine was below 15 mg%. However, sodium and chloride were significantly elevated in all groups at term when the creatinine was above 15 mg%. The osmolality and urea N in the latter group was not significantly different from animals at 100 days gestation. The amylase, lipase, total proteins, albumin, total and direct, and bilirubin in control animals at term was not significantly different from sham operated and experimental subjects. This study suggests that routine amniocentesis in the "high risk" patient would not be diagnostic of fetal intestinal obstruction.


Fine structural changes in the gastro-intestinal tract of the hypoxic puppy: a study of natural history. The present study demonstrates that a 2 hr period of sustained hypoxia results in a focally destructive process, a process which resolves by 5 days. That the changes described in earlier work are not overwhelming to the animal suggest that an early, focal, and reversible stage of the development of acute enterocolitis in the puppy can be described with the aid of electron microsocpy.


A critical appraisal of two common "neonatal" experiment subjects. A comparative study of 11 physiologic variables in 200 piglets and puppies during the first 7 days of life was done. Seven of 11 physiologic variables significantly changed in the 1st wk of the piglets' life. Five of 11 variables significantly changed in the first week of the puppies' life. Six of 11 variables were significantly different when the newborn piglet was compared to the newborn puppy. The rate and/or direction of 7 of 11 physiologic changes during the first day of life were significantly different when the piglet was compared to the puppy. It was concluded that there are marked physiologic differences between: the newborn piglets and the 7 day old piglet; the newborn puppy and the 7 day old puppy; the newborn piglet and the newborn puppy and the "maturation" rate of the piglet and the puppy.


VCN-releasable sialic acid and gangliosides in human neuroblastomas. The ganglioside pattern and VCN-releasable sialic acid residues of six human neuroblastomas were studied. There was no correlation between VCN-releasable sialic acid and prognosis. The ganglioside patterns were more complex in those cases with an expected good prognosis as reflected by the presence of trisialoganglioside. The complexity of the ganglioside pattern did not always correlate with the histologic grade of the tumor. These results suggest the ganglioside pattern may serve as a chemical marker for predicting the prognosis in patients with neuroblastomas.


Prognosis for children with neuroblastoma presenting with paralysis. Since 1947, we have treated 19 children with neuroblastoma whose first symptoms were paralysis or weakness of an extremity, and/or incontinence due to tumor in the spinal canal. In 18 patients, the spine tumor was part of a dumbbell tumor which was present in the adjacent paravertebral area and in one, no extraspinal tumor was found. Aggressive treatment was employed for all. In 17 children, the intraspinal tumor was treated by laminectomy and irradiation with and without chemotherapy. Radiation and chemotherapy were used for two. The extraspinal tumor was excised totally in six and partially in six. All 12 children received postoperative radiation and chemotherapy. In 6 children, the extraspinal tumor was treated only with radiation and chemotherapy. Nine of 19 children are alive without evidence of neuroblastoma. Thirteen patients showed either partial (6) or full (7) neurologic recovery. Survival was related to the child's age at diagnosis and the extent of disease. While 8 of 9 children under 1 yr of age survived, only 1 of 10 children over 1 yr survived. None of the 5 children with Stage IV disease at diagnosis could be saved. The degree and frequency of neurologic recovery were greatest in children whose neurologic symptoms had been present the shortest times and were equal among those who survived and those who died. The outlook for children who became paralyzed by neuroblastoma is not hopeless; therapy aimed at saving life or neurologic function is both worthwhile and rewarding.


The changing signs of congenital hip dislocation. A total of 36 patients (42 hips) with frank congenital hip dislocation were studied. The initial clinical and x-ray signs were evaluated according to the age at which the patient was first seen and treatment started.


Endobronchial cryotherapy in the treatment of tracheal strictures. Modern advances in ventilatory support systems have introduced a patient population requiring long term endotracheal intubation or tracheostomy. The formation of tracheal strictures in such patients remains a very significant clinical problem despite new modifications in endotracheal tube design and materials. Dissatisfied with standard modalities of treatment for these lesions, we have explored the usefulness of endobronchial cryotherapy for the treatment of such stricture. Cervical tracheal strictures were produced in 11 sheep. In six animals a prototype cryosurgical probe was passed through the bronchoscope and these lesions frozen to -80 degrees C. Respiratory epithelial regeneration was complete, but significant reduction in strictures was not noted. Utilizing the cryosurgical probe in conjunction with the endobronchial resection of tracheal strictures in three animals did, however, produce significant reduction in stricture size. Healing following cryonecrosis was associated with minimal fibrosis. Endobronchial cryotherapy is easily performed and has been well tolerated by these animals.


Fiberoptic transillumination: a new tool for the pediatric surgeon. Transillumination (TI) is a safe and reliable technique for evaluating masses or the presence of free air in the thorax or abdomen. TI can also be of help in the accurate placement of catheters or needles in the chest, abdomen, bladder, or vessels. Its use in several hundred cases has been documented by this report.


Late results of ureteroureterostomy in puppies. Experimental resection of a segment of ureter in the puppy with end-to-end ureteroureterostomy led to severe anastomotic stricture, obstructive atrophy, and 100% ipsilateral renal loss at one year. This may have been the result of unrecognized anastomotic tension. Transureteroureterostomy was followed by normally functioning upper urinary tracts at the end of one year, without evidence of damage to the recipient ureter. These experimental findings in the growing animal suggest that transureteroureterostomy in the immature nondilated ureter is a safe and reliable procedure in the management of surgically acquired unilateral segmental ureteral defects.


Surgical management of thirty-nine children with lymphedema. Thirty-nine children underwent staged excisional surgery for lymphedema. The procedures are described in detail. All the children operated on have improved and have a more normal appearance. The decrease in attacks of cellulitis and lymphangitis is striking. The morbidity of this simple procedure is negligible. The operation is tedious, fatiguing, anatomically unexciting, and has a vague end-point. At this time, staged subcutaneous excision appears to be the procedure of choice in moderate to severe lymphedema in children regardless of etiology or classification. The procedure is not a cure.


Maturation of the rectoanal response in premature and perinatal infants. Twenty unselected premature and perinatal infants, and 40 older infants and children with chronic constipation were investigated manometrically. Anorectal pressure studies were found to be a safe and reliable screening method for Hirschsprung's disease. Many unnecessary deep and superficial rectal biopsies were avoided by recording a normal rectoanal response. Failure to record a normal reflex requires further evaluation by tissue diagnosis. A normal reflex does not occur in premature or perinatal infants in whom maturational age (gestational age plus age after birth) has yet to reach 39 wk, and who weigh less than 6 lb.


Need compatibility and marital adjustment in young married couples. This investigation of need compatibility in married couples introduced several theoretical and methodological innovations in an effort to overcome the problems inherent in previous studies. It was predicted that spouses would express greater adjustment on the Locke-Wallace Marital-Adjustment Scale to the extent that they were similar on 9 needs and complementary on 3 needs (Type 1) and 14 need combinations (Type 2). The needs of 66 young married couples were assessed by having them respond to a revised version of Jackson's Personality Research Form under four instructional sets: self, ideal self, spouse, and ideal spouse. The results revealed that although all couples tended to be similar in their ideal ratings, well-adjusted spouses were more similar than poorly adjusted spouses in their self and spouse ratings, as predicted, especially in the needs for affiliation, aggression, autonomy, and nutrurance. No evidence for either Type 1 or Type 2 complementarity emerged. The results were discussed in terms of their implications for Winch's theory of complementary needs and for past and future investigation of need compatibility.


Pitch changes during attempted deception. Two studies on speech samples from 32 male college students are reported. In the first, it was shown that the average voice fundamental frequency of the subjects was higher when lying than when telling the truth. In the second, judges rated the truthfulness of 64 true and false utterances either from an audiotape that had been electronically filtered to render the semantic content unintelligible or from an unfiltered tape. The truthfulness ratings of the judges who heard the content-filtered tape were negatively correlated with fundamental frequency, whereas for the unfiltered condition, truthfulness ratings were uncorrelated with pitch. Although raings made under the two conditions did not differ in overalll accuracy, accuracy differences were found that depended on how an utterance had been elicited originally.


Attributions of blame and coping in the "real world": severe accident victims react to their lot. The purpose of this study was to examine the relation between victims' attributions of causality for their accidents and their ability to cope with severe misfortune. A total of 29 individuals who had been paralyzed in serious accidents were intensively interviewed. Both quantitative and open-ended questions were used to elicit attributions of blame and causality by respondents; coping scores were obtained from a social worker and a nurse familiar with each respondent's case. Findings suggested that blaming another and feeling that one could have avoided the accident were successful predictors of poor coping; self-blame was a successful predictor of good coping. The question, "Why me?" was posed by all respondents, and 28 of the 29 related specific hypotheses that they entertained to explain why the accident had happened to them. Their responses seemed to illustrate the respondents' need for meaning in explaining the selective incidence of the accident.


Self-esteem in young men: a longitudinal analysis of the impact of educational and occupational attainment. This paper analyzes relationships among self-esteem, educational attainment, and occupational status. Data from a nationwide longitudinal study of more than 1600 young men show a substantial increase in self-esteem between 19TT (when respondents were beginning tenth grade) and 1974. Reliability and construct validity data for the self-esteem measure are reported. As expected, both educational attainment and occupational status are correlated with self-esteem. Contrary to expectations, educational attainment as of 1974 is more strongly correlated with tenth grade self-esteem than with 1974 self-esteem. A path analysis led to these conclusions: (a) Self-esteem during high school has little or no direct causal impact on later educational and occupational attainment; self-esteem and attainment are correlated primarily because of shared prior causes including family background, ability, and scholastic performance. (b) Occupational status has a direct positive impact on self-esteem. (c) Post high school educational attainment has no direct impact on self-esteem and only a trivial indirect impact via occupational status. Additional findings indicate that factors associated with educational success become less central to the self-evaluations of young men during late high school and the years thereafter.


GI motor inhibition associated with acute exposure to methyl methacrylate vapor. A mixture of monomeric methyl methacrylate vapor in air was delivered into the breathing air of chloralose-urethan anesthetized dogs. Fixed length exposures to 2000-ppm doses of the vapor resulted in a transient drop in arterial blood pressure and a marked inhibition of ongoing GI motor activities. Motor inhibition always continued for a variable time (approximately 10-15 min) subsequent to the cessation of methyl methacrylate vapor administration. This inhibitory response was not blocked by bilateral vagotomy, spinal transection, splanchnectomy, or the intravenous administration of tetraethylammonium chloride. Another series of experiments determined that the administration of blood from a dog receiving methyl methacrylate vapor produced GI motor inhibition in another dog not connected to the experimental gas mixture. Therefore, it is concluded that, aside from any reflex effects produced, methyl methacrylate vapor in sufficient concentration probably exerts a direct inhibitory effect upon GI smooth muscle that is mediated by the cardiopulmonary systems.


Disposition of sulfonamides in food-producing animals IV: Pharmacokinetics of sulfamethazine in cattle following administration of an intravenous dose and three oral dosage forms. The plasma and urine data obtained following intravenous administration of sulfamethazine to cattle were fit to a one-compartment pharmacokinetic model with a half-life of elimination of 9 hr and a volume of distribution of 0.35 liter/kg. Sulfamethazine was eliminated by excretion of unchanged sulfamethazine (18%) into urine and by formation of three metabolites subsequently excreted into urine. Sulfamethazine also was administered as a solution, a rapid-release bolus, and a sustained-release bolus. The change in the urinary metabolic pattern with different routes of administration suggested that first-pass metabolism was occurring during the absorption process. The absorption half-life was 6 hr. The absorption process for the two solid boluses kinetically appeared to include a dissolution step.


GLC determination of acetohexamide and hydroxyhexamide in biological fluids. A sensitive and specific GLC assay was developed for acetohexamide and hydroxyhexamide, its major metabolite, in plasma and urine. The assay uses tolbutamide as a mass internal standard. Compounds are extracted from acidified plasma or urine with toluene, converted to methylated derivatives with dimethyl sulfate, and measured by GLC using a flame-ionization detector. With GLC-mass spectrometry, the compounds measured are the N-methylsulfonamides resulting from GLC pyrolysis. Plasma and urine data are presented from a bioavailability study to demonstrate the utility of this method.


Structure-activity studies using valence molecular connectivity. The extension of the molecular connectivity concept to the treatment of heteroatom molecules affords an opportunity to examine structure-activity relationships in a wide variety of molecule series that possess biological activity. Four series are described in this report. The correlations found indicate that molecular connectivity is an extremely useful descriptor of structure in studying drug molecule structure-activity relationships.


Bioavailability of digoxin-hydroquinone complex: a new oral digoxin formulation. A new oral digoxin formulation, a digoxin-hydroquinone complex (99% dissolution at 5 min), was evaluated in 12 healthy human volunteers with reference to bioavailability and extent and time of peak serum digoxin levels. This preparation was compared with a commercial digoxin tablet (26% dissolution at 5 min), digoxin elixir, and a parenteral digoxin solution. Bioavailability was assessed by the 24-hr area under the serum digoxin-time curve and 48-hr digoxin excretion in urine. The bioavailability of the complex was similar to that of the elixir but not statistically different from that of the tablet. The tablet was less bioavailable than the elixir. There was less interindividual variation in bioavailability with the complex than with the elixir. Peak serum digoxin levels were higher with the complex than the tablet and were achieved more quickly.


Diffusion model for drug release from suspensions I: theoretical considerations. A new mathematical model based on physicochemical principles is presented; it does not require a "diffusion layer" for the release of a suspended drug from a semisolid vehicle. This general model has wide range application to systems where release is controlled by the diffusion rate or dissolution rate of a drug. The appropriate mathematical relationships are derived and evaluated. Theoretical drug concentration distributions in the vehicle and a membrane and the predicted cumulative drug mass uptake by blood under specified conditions are presented. The dissolution rate of solid drug in the vehicle markedly influences predicted drug release using the model presented. It is anticipated that the model will stimulate further research to confirm or reject the assumption that the dissolution rate may be slow enough to be important in the systems studied.


Diffusion model for drug release from suspensions II: release to a perfect sink. Numerical mathematical methods are applied to a diffusion model based on physicochemical principles to predict drug release from suspensions of drug in semisolid vehicles. The predicted mass of drug released versus time curves using this model are in agreement with some reported experimental data but differ from predictions using the classical model for semisolid suspensions. The differences are discussed in relation to the drug dissolution rate and diffusion rate in the vehicle.


Polymorphism of phenylbutazone: properties and compressional behavior of crystals. Data from X-ray diffraction, thermal analysis, IR spectroscopy, and solubility studies were used for the identification and characterization of four crystalline modifications of phenylbutazone. The thermal behavior of the polymorphs under different treatment conditions also was investigated. Compression of the thermodynamically unstable forms, at a compression force of 1590--2040 kg, induced polymorphic changes in the crystals. Similar changes also were produced through grinding. The apparent equilibrium solubilties of polymorphs were determined, as was the dissolution of the polymorphs as compressed disks in an aqueous medium. The small effective surface area possessed by one polymorph resulted in slow dissolution.


Antipyretic testing of commercial aspirin formulations in rats. Four commercial aspirin formulations and aspirin powder USP were assayed in yeast-fevered rats for antipyretic activity. Tablets allowed to disintegrate spontaneously prior to dosing yielded aggregates of various sizes which failed to produce uniform patterns of antipyresis. When tested at smaller, more uniform particle sizes of total product, consistent, statistically significant antipyresis was observed with no significant variation among formulations. The ED50 values and parallel line assays were homogeneous.


Effect of temperature and relative humidity on nitrazepam stability in solid state. The decomposition of a 1% dilution of nitrazepam in microcrystalline cellulose was established by quantitative determination of the two main breakdown products, 2-amino-5-nitrobenzophenone and 3-amino-6-nitro-4-phenyl-2(1H)-quinolone, using in situ diffuse reflectance measurements on thin-layer chromatograms. The decomposition and formation rate constant of nitrazepam and of the breakdown products, respectively, were determined at four temperatures and six relative humidities. By means of a three-parameter regression equation, it was possible to correlate quantitatively the decomposition constant of nitrazepam to both temperature and relative humidity.


High-performance liquid chromatographic determination of chlordiazepoxide and major related impurities in pharmaceuticals. A rapid, precise, forward-phase (adsorption) high-performance liquid chromatographic procedure is presented for the determination of chlordiazepoxide and two common impurities, 7-chloro-1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one 4-oxide and 2-amino-5-chlorobenzophenone, in commercial formulations and for the determination of the benzophenone in the chlordiazepoxide drug substance. The method involves simultaneous quantitation of chlordiazepoxide and the 1,3-dihhydro impurity, followed by quantitation of the benzophenone from a separate sample extract using a second mobile phase. A single microparticulate silica gel column is used throughout. Nitrazepam and o-dinitrobenzene are the internal standards, Quantitation is by peak area using a computing integrator, except that the peak due to the benzophenone is quantitated by peak height. The described procedure is of equivalent precision, but superior accuracy, to the BP 1973 spectrophotometric procedure for the analysis of chlordiazepoxide in chlordiazepoxide formulations. Quantitation of the 1,3-dihydro and the benzophenone impurities at levels as low as 6.3 and 0.9 ng, respectively, is demonstrated.


Stable nonaqueous pentobarbital sodium solutions for use in laboratory animals. The degradation kinetics of pentobarbital sodium in propylene glycol-based solutions were studied along with the in vivo effects in laboratory animals. The degradation rate constant was directly proportional to the water concentration in propylene glycol-water solvent systems. An activation energy of 23.4 kcal/mole was obtained in propylene glycol-water (1:1). Pentobarbital sodium solutions in anhydrous propylene glycol and 9:1 mixtures of propylene glycol with ethanol, glycerin, or dimethylacetamide gave relatively slow degradation rates at 100 degrees with all projected 25 degrees t 99% values greater than 4.5 years. Intravenous administration of pentobarbital sodium in various anhydrous propylene glycol-based vehicles to rats produced no hemolysis of gross organ damage that would interfere with pathological evaluations. Results of an intraperitoneal sleeptime study indicated that pentobarbital sodium produced consistent hypnotic effect when administered as an aqueous solution or in anhydrous propylene glycol-based vehicles.


Bactericidal properties of quaternary ammonium compounds in dispersed systems. Alkyltrimethylammonium bromides of selected chain length were synthesized and characterized with respect to their bactericidal properties. A partitioning method was developed, and the aqueous phases of the partitioned systems were evaluated for their antibacterial activity against Staphylococcus aureus. The relationships between the quaternary ammonium compound chain length and the aliphatic alcohol chain length were determined. The effect of selected hydrocarbons on the bactericidal effectiveness of the systems was studied. Cream systems corresponding to the partitioned systems were prepared and evaluated against S. aureus. The relationship between the aqueous phase concentration of the bactericidal agent was studied, and a correlation was shown between the bactericidal activity of the partitioned systems and cream systems.


Determination of solasodine in fruits of Solanum species. A potentiometric nonaqueous titration procedure was developed for the quantitative determination of solasodine in fruits of the Solanum species. The steroid glycoalkaloids were extracted from freshly harvested fruits with 2% acetic acid and methanol. After hydrolysis, the common aglycone solasodine was extracted with benzene. An aliquot was mixed with an equal volume of acetone and titrated potentiometrically with 0.005 N perchloric acid in dioxane, using glass and silver electrodes for the determination.


Utilization of cyclodextrin complexation for separation of E, A, and B prostaglandins by ion-exchange liquid chromatography. Application of cyclodextrin complexation to the separation of E-, A-, and B-type prostaglandins by ion-exchange liquid chromatography is demonstrated. The addition of alpha-or beta-cyclodextrin into the mobile phase on an anion-exchange support decreased the retention times of the prostaglandins significantly because of soluble complex formation. Chromatographic separation behavior is discussed on the basis of the stability of the inclusion complex. A rapid and sensitive method for the separation and quantification of the prostaglandins, using beta-cyclodextrin in the mobile phase, is described.


Benzoyl peroxide stability in pharmaceutical gel preparations. The storage stability of benzoyl peroxide in the presence of both individual and combined pharmaceutical gel ingredients was investigated. Benzoyl peroxide was quite unstable in the presence of nucleophilic agents and certain acidic substances. At both 30 and 40 degrees storage temperatures, benzoyl peroxide was destroyed rapidly (within 1 month) in the presence of ethanol and acidic chelating agents. The substitution of acetone for ethanol, the elimination of chelating agents, and the addition of sodium hydroxide to gel preparations markedly reduced degradation.


GLC determination of free triclocarban in blood. A method is presented for the quantitative determination of free triclocarban in rat or human blood. The procedure involves the extraction from blood with acetone, a TLC cleanup, derivatization with N,O-bis (trimethylsily) acetonide, and GLC using an electron-capture detector. GLC-mass spectral analysis confirmed that the structure of the derivative was a bis (trimethylsilyl) molecule with one group on a nitrogen and the second group attached to the enol tautomer. The method is sensitive to 25 ng (12.5 microgram/liter of blood). Recoveries of added triclocarban in the 12.5--50-microgram/liter range weree between 80 and 90%.


Effect of surfactants on absorption through membranes V: Concentration-dependent effect of a bile salt (sodium deoxycholate) on absorption of a poorly absorbable drug, phenolsulfonphthalein, in humans. The effect of administration of 600-and 300-mg doses of sodium deoxycholate 1 hr before phenolsulfonphthalein solution is reported. The 600-mg dose caused a decrease in drug bioavailability as measured by the total amount excreted in 24 hr. The 300-mg dose cause and increase in the initial phenolsulfonphthalein absorption rate, suggesting a direct action of the bile salt on membrane permeability. The decrease in absorption upon administration of 600 mg was attributed to micellar entrapment of the drug molecule.


Uptake of acetazolamide by human erythrocytes in vitro. The binding of acetazolamide to human erythrocytes was studied in vitro. Blood and plasma samples were analyzed by electron-capture GLC. At 37 degrees, drug equilibrated between plasma and erythrocytes in approximately 40 min. The effect of plasma concentration on the steady-state level of drug within the erythrocytes was examined. Erythrocyte accumulation of acetazolamide appeared to be a composite of two processes: a nonlinear, saturable process and a linear, diffusion-controlled process. By appropriate linear transformation of the data, estimates of the data, estimates of the erythrocyte binding capacity and the dissociation constant for the drug were obtained.


Direct analysis of salicylic acid in keratolytic plaster by gas-solid chromatography. A rapid gas-solid chromatographic method is reported for the direct analysis of salicylic acid in keratolytic plaster. The method requires no preseparation or derivatization and takes about 14 min. Since it requires only 2-7 mg of sample, it can determine the salicylic acid concentration in a particular area of plaster. The analyzing column is packed with porous polymer beads of 2,6-diphenyl-1,4-phenylene oxide. An automatic solid sampling system is used to connection with the gas chromatograph employing dual flame-ionization detectors. The average recovery of salicylic acid in synthetic samples containing 400-2700 microgram was 100.6 +/-1.6%. The average correlation coefficient of the peak area against the standard was +0.9995 +/- 0.0003 for samples in the 300-3000-microgram range.


Stability of phenylbutazone in presence of pharmaceutical colors. The degradation of phenylbutazone was studied in the presence of lakes suitable for coloring the sugar coats of phenylbutazone tablets. The drug was degraded, in light, in the presence of erythrosine sodium. The degradation probably proceeds via singlet oxygen generated by the light-exicited dye. The degradation may be important in some quality control procedures and can lead, for example, to unusual results in dissolution rate testing.


High-pressure liquid chromatographic analysis of polythiazide in pharmaceutical tablet formulations. A high-pressure liquid chromatographic method was developed for the quantitative determination of polythiazide in pharmaceutical tablet formulations after extraction of the powdered tablets with a water-acetonitrile solvent. Analysis is a accomplished by comparison of peak areas after chromatography.


Quantitative high-pressure liquid chromatographic determination of thimerosal in pharmaceutical formulations. A quantitative high-pressure liquid chromatographic method an anion-exchange resin column and an aqueous perchlorate solution as the mobile phase is employed for the determination of thimerosal in pharmaceutical formulations. With a liquid formulation containing large amounts of edetate disodium, calcium chloride is used for complexation to eliminate the interference from edetate disodium.


Mathematical description of solute velocities during dissolution from a horizontal surface. A mathematical analysis of solute flow in a descending column following dissolution is presented. The acceleration of a solute particle from zero velocity, when it is in the solid phase, to its final equilibrium descending velocity was analyzed. The maximum velocity for N-(3-methylphenyl) acetamide developed essentially at the solid-liquid interface, contradicting the postulate of a microsize diffusional layer. The possibility of a diffusional layer existing for solids of lower solubility than N-(3-methylphenyl)acetamide is discussed.


Novel method for determination of partition coefficients of penicillins and cephalosporins by high-pressure liquid chromatography. Newly defined lipophilic indexes, log k', of a series of penicillins and cephalosporins were rapidly and reliably determined by reversed-phase high-pressure liquid chromatography (HPLC) on bonded octadecylsilane supports. The log k' values obtained from their retention times exhibited a linear relationship with methanol concentration (v/v%) in the mobile phase. The extrapolated log k' values to zero and those at 30% correlated well with the partition coefficients, log P, in 1-octanol-water and with Rm values from TLC. This HPLC technique provided some new log P and Rm values for highly ionizable beta-lactam antibiotics. The HPLC method for the determination of partition coefficients of drugs has some advantages and is a useful alternative for the determination of log P and Rm.


Rapid GLD determination of ibuprofen in serum. A rapid procedure for the determination of ibuprofen in human serum was developed using a single extraction with carbon tetrachloride after deproteinization with perchloric acid. The internal standard, 3-methyl-3-phenylbutyric acid, was added directly to the serum. Gas chromatograms were free of interfering peaks. Calibration curves (0--40 micron g/ml) were linear with a sensitivity of 0.5 micron of ibuprofen/ml of serum. Relative standard deviations ranged from 1.1 to 25%.


Liquid chromatography in pharmaceutical analysis VII: determination of dantrolene sodium in biological fluids. Dantrolene sodium can be determined in plasma and urine samples by high-pressure liquid chromatography without interference from its two major metabolites, the hydroxy and acetamido compounds. The minimum detectability of the drug using this procedure is 8 ng. The complete assay including extraction, evaporation, and separation steps can be performed in approximately 70 min with an accuracy of 1--3%.


Polynitro aromatic compounds in analytical chemistry I: reaction with ouabain and digitoxin. By the use of NMR spectroscopy, the highly colored reaction products formed by ouabain or digitoxin in with 1,3,5-trinitrobenzene or 2,4,6-trinitroanisole in the presence of alkali (as used for the determination of these glycosides) are shown to be Meisenheimer complexes. The complexes are produced by attachment of a carbon of the butenolide ring to an aromatic carbon of the nitro compound with formation of a charge-delocalized cyclohexadienate anion.


Sensitive assay procedure for ethambutol hydrochloride via charge transfer complex formation. The charge transfer complex formation between ethambutol and iodine was investigated and utilized as the basis for a sensitive spectrophotometric procedure for ethambutol and its dosage forms. The solutions exhibited blue-shifted iodine bands at 293 and 360 nm. A Job's plot of corrected absorbance against the mole ratio of ethambutol to iodine indicated a 1:2 drug-iodine ratio. At 293 nm, the absorbance was linear (r=0.9998) over the 0.25-15-microgram/ml concentration range, but the concentration range for best accuracy is 1.6-5.8 microgram/ml. The method can be applied successfully to the analysis of commercially available ethambutol tablets.


GLC determination of lasalocid and its bromo analog as their silyl derivatives. A GLC method is presented for the determination of lasalocid and its bromo analog. The method is based on the quantitative trimethylsilylation of the compounds without any molecular cleavage, followed by chromatography on a nonpolar silicone column. Silylation was carried out directly without any extraction or prior cleanup, despite the complexity of the dosage forms. This procedure was used for the assay of pure substances, pellets, premixes, experimental ampul solutions, and mycelial filter cakes. The results were in good agreement with data obtained by microbiological procedures.


Simplified method to study stability of pharmaceutical preparations. Data simulating zero-, first-, and simple second- and third-order kinetic reactions are employed at four elevated temperatures. The existence of a linear relationship is established between the logarithm of t0.9 (the time required for the concentration of the reactant remaining to decompose to reach 90% of its original value) and the reciprocal of the corresponding temperature in absolute degrees. The independence of the result from the order of the reaction is reconfirmed using literature data. The application of the linear relationship to predict the shelflife of dosage forms is discussed.


Simple GLC determination of ethylene oxide and its reaction products in drugs and formulations. Convenient rapid GLC methods for the estimation of residual ethylene oxide, ethylene chlorohydrin, and ethylene glycol in ethylene oxide-sterilized bulk drugs and formulations prepared therefrom are described. Ethylene oxide was chromatographed using a porous polymer column; ethylene chlorohydrin and ethylene glycol were chromatographed using either polyethylene glycol 400 or a porous polymer column. All three residuals were determined from the same sample preparation for each type of drug or formulation examined. Recoveries of each of the three residuals were greater than 95% for all samples examined. Detection limits, at moderate electrometer sensitivities, were 2 microgram/g or ml for ethylene oxide and ethylene chlorohydrin and 5 microgram/g or ml for ethylene glycol. The most likely interferences are discussed.


Enzymatic activity of pig heart mitochondrial malate dehydrogenase monomolecular films by surface exchange technique. A technique for studying the catalytic activity of enzymes spread as a film at an air-water interface, by exchanging the subphase under the film to remove unspread enzyme molecules, was developed, and its effectiveness was studied using surface-spread mitochondrial malate dehydrogenase. Mitochondrial malate dehydrogenase formed stable films which gave reproducible pi-A curves. The enzyme activity was measured by the oxidation rate of reduced nicotinamide adenine dinucleotide (NADH) in the presence of the substrate oxalacetic acid. Oxalacetic acid and NADH were injected into the subphase. The catalytic activity of the enzyme was dependent on the surface pressure of the film. The maximum catalytic activity was observed at a surface pressure of 4.4 dynes/cm. The activity was higher at intermediate surface pressures than at very low or very high surface pressures. A high bulk catalytic activity was observed in the unstable region, i.e., at a high degree of compression, of the film. The catalytic activity of the surface-spread enzyme was only a fraction of an equivalent amount of enzyme in solution.


GLC determination of plasma acenocoumarol levels. A method for the quantitative estimation of acenocoumarol in plasma is described. Plasma containing acenocoumarol, to which a known amount of gamma-oxo derivative of phenylbutazone is added as an internal standard, is acidified and extracted with ethylene dichloride. The drug and the internal standard are then back-extracted into alkali, which, in turn, is acidified and reextracted with ethylene dichloride. The organic extract is evaporated and treated with an ethereal solution of diazomethane (100 microliter). The reacted mixture is evaporated, and the residue is dissolved in 25 microliter of carbon disulfide. Aliquots (2-3 microliter) are injected into a gas chromatograph equipped with a flame-ionization detector. The methyl derivatives of acenocoumarol and the internal standard give sharp, well-separated, symmetrical peaks. The method is of sufficient sensitivity to determine 0.25 microgram/ml of the drug in plasma with a relative standard deviation of 4%.


Binding of codeine, morphine, and methadone to human serum proteins. The binding properties of codeine, morphine (as representative opium alkaloids), and methadone (a synthetic pharmacologically similar compound) were studied with selected human serum proteins. The methodology involved equilibrium and dynamic dialysis using 3H-and/or 14C-labeled compounds. For estimation of the percent binding with equilibrium dialysis, concentrations of the ligand used were approximately therapeutic blood levels and another concentration 30-60 times higher. The percent binding to whole human serum ranged from about 20% for morphine to almost 60% for methadone. Of the human serum proteins investigated, the highest percent binding was found with albumin, except for methadone for which it was beta-globulin III. The affinity for other serum proteins varied with the ligand. In studies with albumin using dynamic dialysis, the plots of nubar divided by free concentration versus nubar were similar for all three ligands studied and had positive slopes, unlike those reported for acidic compounds for which the slope is always negative. In studies of binding of one ligand in the presence of another, significant competition was demonstrated, suggesting that the same binding sites were involved.


Liquid chromatography in pharmaceutical analysis VIII: determination of isoniazid and acetyl derivative in plasma and urine samples. Parameters are described for the qualitative and quantitative analysis of a mixture of isoniazid and its acetyl derivative. The compounds are chromatographed on an octadecylsilane column, using absolute methanol-distilled water (60:40) at pH 2.5 containing 0.01 M dioctyl sodium sulfosuccinate. The flow rate was 2.0 ml/min (2500 psig). The separation and quantification are applicable to plasma and urine samples. The determination in each biological fluid can be achieved in approximately 90 min with percentage accuracies for isoniazid of 5.25 and 7.45 and for the acetyl derivative of 4.47 and 1.56 in plasma and urine, respectively.


In vitro and in vivo considerations of a novel matrix-controlled bovine progesterone-releasing intravaginal device. An in vitro system measuring progesterone release from silicone matrixes into serum is described. Drug release followed a matrix-controlled diffusion model in which the cumulative quantity released was linear with the square root of time. A bovine intravaginal device, consisting of a steel coil coated on both sides with a progesterone silicone matrix, was used as an in vivo drug delivery system. In vivo drug release also was matrix controlled, with rates comparable to those obtained in vitro. However, lag times of 1.7 and 4.2 days before reaching the steady-state rate were obtained for the outer and inner surfaces, respectively. The combination of effects resulted in a pseudo-zero-order drug-releasing device in which cumulative drug released was linear with time for at least 16 days.


Prostaglandin monolayers II: monomolecular film behavior of dinoprost C-15 alkyl esters. Monomolecular film compression-relaxation behavior was examined for select dinoprost C-15 alkyl esters. Higher homologs of the series such as palmitate and decanoate esters yielded stable expanded monolayers that exhibited minimal relaxation of surface pressure during noncompression. Their limiting molecular areas were consistent with a Hirschfelder model projection in which the prostaglandin moiety assumes a horizontal orientation at the interface with its alkyl ester chain oriented vertical to the surface plane. Shorter chain homologs such as hexanoate, valerate, butyrate, propionate, and acetate also formed expanded monolayers but exhibited increased instability with decreased alkyl chain length, as reflected in their lower surface pressure development during compression and significant relaxation of pressure during noncompression. Such instability can be tied to their increased solubility in the subphase solution and higher desorption rate from the interface.


Effect of primidone concentration on glass transition temperature and dissolution of solid dispersion systems containing primidone and citric acid. The glass transition temperatures of glasses containing various concentrations of primidone in citric acid were measured and found to increase as the primidone concentration increased. Dissolution studies of these systems and particle-size measurements of primidone precipitated during dissolution of devitrified glasses suggest that the increase in the dissolution rate of the devitrified systems is due to both the small size of the precipitated crystals and the excellent wettability of these systems.


Quantitation of the antimalarial agent, mefloquine, in blood, plasma, and urine using high-pressure liquid chromatography. Sensitive and specific assays are described for the quantitation of mefloquine in whole blood, plasma, and urine specimens using high-pressure liquid chromatography. Specimens were extracted with ethyl acetate and concentrated before chromatography. Whole blood and plasma extracts were chromatographed on a polar bonded phase partitioning column, and urine extracts were chromatographed on a bonded reversed-phase partitioning column. The sensitivity of the assays for mefloquine was 0.05 microgram/ml of whole blood or plasma and 0.25 microgram/ml of urine using 5-ml samples. The assays are suitable for studying mefloquine pharmacokinetics in humans.


Cytolysis of neuroblastoma cells in vitro and treatment of neuronal tumors in vivo with bromoacetylcholine. The effect of bromoacetylcholine on mouse neuroblastoma C-1300 was investigated in cell culture as well as in A/J mice. In vitro, bromoacetylcholine (1 X 10(-5) M) was a potent cytolytic agent and produced an additive effect in combination with vincristine (3 X 10(-9) M). Since the choline acetyltransferase inhibitor, dimethylaminoethyl chloroacetate, does not inhibit neuroblastoma efficiently in vitro, the potent cytolytic action of bromoacetylcholine is probably not due to its choline acetyltransferase inhibitory action. Furthermore, the neuroblastoma inhibitory effect of bromoacetylcholine was not affected by atropine. Therefore, the inhibitory action is not related to the interaction of bromoacetylcholine with muscarinic receptors either. In in vivo experiments, 1, 10, or 30 mg/kg of bromoacetylcholine was injected directly into the tumors three times daily for 6 weeks. Bromoacetylcholine at 10 and 30 mg/kg gave significant protection of A/J mice from the death induced by neuroblastoma inoculation, and the lifespan was prolonged significantly with these bromoacetylcholine treatments.


Determination of triprolidine in human plasma by quantitative TLC. A chromatographic thin-layer fluorescence procedure, with a sensitivity limit of 0.8 ng/ml, is described for the quantitative analysis of triprolidine in human and rat plasma. Following the intravenous administration of 1 mg/kg of triprolidine to rats, the drug distributed rapidly into tissues and was eliminated from plasma with a half-life of 53 min. The method was used to determine the plasma triprolidine levels in 16 normal human volunteers following oral administration of 3.75 mg of triprolidine hydrochloride in 15 ml of a syrup. The drug obtained a mean peak plasma level of 8.2 ng/ml in 2 hr and was eliminated from the plasma with a half-life of 5 hr. Considerable individual variation was observed in the area under the plasma triprolidine level-time curve; values ranged from 19 to 163 ng hr/ml with a mean value of 75 ng hr/ml.


Potential antitumor agents: procarbazine analogs and other methylhydrazine derivatives. With the objective of developing new antitumor agents, two groups of hydrazine compounds, having structural features in common with the antitumor agents procarbazine and 1-acetyl-2-picolinoylhydrazine, were synthesized. The L-1210 leukemia system was used to evaluate compounds of both groups. The aliphatic procarbazines also were screened for antitumor activity as bis(benzyloxycarbonyl) derivatives and as derivatives having a phthalazine nucleus. No L-1210 antitumor activity was exhibited by these compounds.


Formulation factors affecting strength and dissolution of uncoated oxytetracycline tablets. The effect of various formulation and processing factors on the properties of 300-mg oxytetracycline tablets was studied. At a constant moisture level and packing fraction, an increase in gelatin concentration resulted in increased tensile strength, increased disintegration and dissolution times, and reduced capping tendency. The Wagner theory of dissolution applied satisfactorily to tablets containing up to 5% (w/w) gelatin but was less applicable at higher gelatin levels. Dissolution rate constants were calculated, and their values depended on the gelatin content and packing fraction of the tablets.


Pharmacokinetics of methylphenidate in the rat using single-ion monitoring GLC-mass spectrometry. A GLC-mass spectrometric assay for methylphenidate in biological fluids was developed using the ethyl ester homolog of the drug as the internal standard. The procedure has a lower level of sensitivity of 1.2 ng/ml and is based on GLC-mass spectrometic monitoring of the m/e 180 ion common to the mass spectra of the N-trifluoroacetyl derivatives of the drug and internal standard. The brain and plasma levels of methylphenidate in rats were determined after intravenous administration of 0.5 mg/kg of the drug. The two-compartment open pharmacokinetic model fit the data.


GI absorption of niacin in humans.

GI absorption of niacin in humans. By using the GI tube technique, niacin was shown to be equally well absorbed from the stomach and the upper small intestine. The maximum plasma niacin concentrations occurred 10-20 and 5-10 min, respectively, after instillation. Thus, the physiological prerequisites for a physically retarded niacin preparation were established.


Alkaloids of Glaucium flavum Grantz, populations Isfahan and Kazerun. Glaucium flavum Grantz, population Isfahan, contained four major alkaloids: dicentrine (0.8%), bulbocapnine (0.42%), protopine (0.35%), and salutaridine (0.2%). G. flavum Grantz, population Kazerun, contained four major alkaloids: dicentrine (1.4%), bulbocapnine (0.5%), O-methylflavinantine (0.5%), and salutaridine (0.3%); it also contained two minor alkaloids, protopine and alpha-allocryptonine. O-Methylflavinantine was found for the first time in the Papaveraceae.


Rapid determination of procainamide and its N-acetyl derivative in human plasma by high-pressure liquid chromatography. A rapid, specific, high-pressure liquid chromatographic method for the determination of procainamide and its N-acetyl derivative in plasma was developed. The procedure is fast enough (15 min from receipt of blood to reporting value) to be used for emergency determinations. The sensitivity, precision, and accuracy are sufficient for routine monitoring of therapeutic levels in patients. The assay is specific enough to be valid in the presence of a number of drugs and dietary substances present in clinical samples.


Lipid-protein interactions: detergent binding to L-glutamic acid dehydrogenase. A nonionic detergent was found to bind to the enzyme L-glutamic acid dehydrogenase [L-glutamate:nicotinamide adenine dinucleotide phosphate oxidoreductase (deaminating) EC 1.4.1.3]. The amount bound was 17 moles of detergent/mole of enzyme, which, however, was not sufficient for the enzyme to be included in a detergent micelle.


Separation and quantitative determination of 2,4-disulfamyl-5-trifluoromethylaniline in hydroflumethiazide using high-pressure liquid chromatography. A high-pressure liquid chromatographic method was developed to quantify 2,4-disulfamyl-5-trifluoromethylaniline in hydroflumethiazide using a bonded pellicular packing. An internal standard was added to the samples to ensure reproducibility. The results were compared with methods currently in use.


Enhancement of intestinal glucose transport following chronic parathion poisoning. Chronic administration of parathion to male rats stimulated glucose (p less than 0.05) but not calcium (p greater than 0.05) transport in the everted duodenal gut sac preparation. Chronic parathion stimulation was not reduced by concurrent administered of atropine. Acutely applied parathion or paraoxon, its active metabolite, did not increase glucose transport in this preparation.


Metabolic studies with the nonnutritive sweetener cycloheptylsulfamate. The nonnutritive sweetener cycloheptylsulfamate was administered orally to rabbits and rats. The urine of each species was separately collected for 3 days and examined for the metabolites cycloheptylamine, cycloheptanone, and cycloheptanol and for cycloheptylsulfamate. A previously tested GLC method was adapted for the determination of the metabolites. Cycloheptylsulfamate was assayed by hydrolysis and subsequent measurement of the absorbance of the product formed (lambdamax=489 nm) by the liberated amine with p-benzoquinone. The conversions to the metabolites were 0.276, 0.390, and 0.170%, respectively, in rabbits and 0.064, 0.022, and 0.017%, respectively, in rats.


NMR solvent shift data for methoxylated xanthones. The NMR spectra of 1-, 2-, 3-, and 4-hydroxyanthones, 1,3-, 1,5-, 1,6-, 1,7-, 1,8-, 2,5-, 3,4-, 3,5-, 3,6-, and 4,5-dihydroxyxanthones, 1,3,6- and 1,3,8-trihydroxyxanthones, and 1,3,6,8-tetrahydroxyxanthone, as well as those of the corresponding methyl ethers and acetates, were recorded. The spectra of the methyl ethers were measured in deuterochloroform, benzene, trifluoroacetic acid, and 3% trifluoroacetic acid in benzene. The solvent shift parameters for the methoxyl resonances are tabulated and discussed.


Synthesis of 5-substituted 2-oxazolidinethiones and their antagonism to uterotropic effect of diethylstilbestrol. 5-(4-Aminophenoxymethyl)-2-oxazolidinethiones were synthesized by the cyclization of 1-(4-aminophenoxy)-3-amino-2-propanol in the presence of potassium hydroxide and carbon disulfide. This oxazolidinethione, on reaction with suitable isothiocyanates, yielded 5-[4-(substituted thiocarbamido)phenoxymethyl]-2-oxazolidinethiones. These compounds antagonized the uterotropic effects of diethylstilbestrol in female rats and possessed approximate LD50 values of 400-greater than 800 mg/kg.


Cytotoxic agents from Bursera klugii (Burseraceae) I: isolation of sapelins A and B. A crude chloroform-soluble fraction of the ethanol extract of the leaves of Bursera klugii showed activity against two test systems, the P-388 lymphocytic leukemia (3PS) and the human epidermoid carcinoma of the nasopharynx (9KB). The PS activity was due to two constituents, sapelins A and B.


Quinuclidine chemistry: autocondensation reactions of 3-quinuclidinone. During the synthesis of 3-hydroxy-3-ethinylquinuclidine (I), two additional products were isolated and identified as (E)-3-[2-(3-oxoquinuclidine)]quinuclidylidene (III) and (E)-3-[2-(3-hydroxy-3-ethinylquinuclidine)]quinuclidylidene (V). The base-catalyzed autocondensation of 3-quinuclidinone resulted in the alpha,beta-unsaturated ketone dimer (III) as a single isomer. The geometric configuration was deduced by examination of the NMR spectra of the methyl iodide salt. Compound V was thus the result of attack on the carbonyl carbon of III by the acetylide anion. The isolation and identification of these compounds clarified the reported differences in the physical properties of I and its analogs.


Modified electron-capture GLC assay for salsolinol in brain tissue. A modified assay for a neuroamine-derived tetrahydroisoquinoline, salsolinol, is presented. It combines the ease and rapidity of solvent extraction from brain tiessue with the sensitivity of electron-capture GLC. Detection of salsolinol (1,2,3,4-tetrahydro-1-methyl-6,7-isoquinolinediol), the alkaloid derived from condensation of dopamine and acetaldehyde, at levels of 5-10 ng/g of brain tissue is possible. The advantages afforded by the modifications are discussed in relation to existing procedures.


Quantitative determinations of codeine phosphate, guaifenesin, pheniramine maleate, phenylpropanolamine hydrochloride, and pyrilamine maleate in an expectorant by high-pressure liquid chromatography. The quantitative determinations of codeine phosphate, guaifenesin, pheniramine maleate, phenylpropanolamine hydrochloride, and pyrilamine maleate in a liquid dosage form are described. All active and inactive ingredients (sodium benzoate and FD&C Yellow No. 5 dye) can be separated with high-pressure liquid chromatography except the two antihistamines, pheniramine maleate and pyrilamine maleate. Pheniramine maleate is determined colorimetrically, and pyrilamine maleate is determined either by difference or spectrophotometrically. The methods are simple short, accurate, and precise. The standard deviations are reported.


Quantitative determinations of antipyrine and benzocaine in ear drops by high-pressure liquid chromatography. Antipyrine and benzocaine were determined quantitatively in ear drops by high-pressure liquid chromatography on an octadecyltrichlorosilane permanently bonded to a Si-C column, using 0.02 M KH2PO4 in methanol-water as the mobile phase. Both compounds can be assayed in combination directly without interference from each other or from oxyquinoline sulfate (the preservative). The method is accurate, precise (estimated universe standard deviations of 0.68% for antipyrine and 1.18% for benzocaine), simple, and short (requires 30 min versus 2-3 hr by the NF method). The method was tried on a commercial product with excellent results and can be used in the presence of decomposition products.


GI pharmacology of polyethyleneimine I: effects on gastric emptying in rats. Experiments were conducted to determine the effect of ingested polyethyleneimine upon gastric emptying of the fasted rat. Emptying was evaluated by the phenolsulfonphthalein and resin bead methods. The two techniques gave comparable results; both showed that this agent inhibited gastric emptying. A delay in gastric emptying could be detected within 15 min of intubation. The effect was dose related, quite long lasting (approximately 4 hr), and reversible. Commercially available, branched polyethyleneimines were highly active, but the linear polyethyleneimine was without observable effect. A branched polyethyleneimine derivative with all primary amine sites selectively acetylated also was inactive.


New compounds: potential antituberculous agents I: alkylaryl 4-arylformamidinothiosemicarbazones. A series of alkylaryl 4-arylformamidinothiosemicarbazones was synthesized for evaluation as antituberculous agents. The synthesis was effected by the condensation of different arylcyanamides with various thiosemicarbazones. The required intermediates also are described.


Plasma catecholamine concentrations in unanesthetized rats during sleep, wakefulness, immobilization and after decapitation. A relatively unstressful technique for obtaining blood samples from rats has been employed to determine the amounts of catecholamines in blood during physiological sleep, undistrubed wakefulness, gentle handling and physical immobilization. These circulating plasma levels of catecholamines [0.46 ng of norepinephrine (NE) and 0.18 ng of epinephrine (EPI) per ml*were found to be markedly lower than previously reported for rats, which were generally handled or restrained prior to blood sampling. Compared with animals in natural sleep, awake rats had increases in plasma levels of EPI but larger increases of NE. Gentle handling, produced an additional increase in EPI only, whereas physical immobilization, produced massive elevations of circulating levels of both EPI and NE. Decapitation was found to be associated with a 10-fold increase in circulating NE and an 80-fold increase in circulating levels of EPI, whereas dopamine remained at undetectable levels. The high levels of plasma catecholamines in rats compared with other animals and humans, and changes produced in pharmacological and physiological experiments, probably reflect environmentally induced changes in sympathoadrenomedullary activity rather than differences in basal sympathetic neuronal activity.


A comparison of the effects of haloperidol on dopamine turnover in the striatum, olfactory tubercule and median eminence. A sensitive radioenzymatic procedure was used to quantify the effect of haloperidol on dopamine concentrations and rates of turnover in rat striatum, olfactory tubercle and median eminence, regions containing terminals of nigrostriatal, mesolimbic and tuberoinfundibular neurons, respectively. Haloperidol (2.5 mg/kg s.c.) did not alter the steady-state concentrations of dopamine in any of these brain regions at any time. Haloperidol increased dopamine turnover in the striatum and olfactory tubercle 2 and 8 hours after adminstration. The rate of dopamine turnover was increased only in the median eminence 16 and 24 hours after the administration of haloperidol, and effect which was blocked by hypophysectomy. Two other antipsychotic agents, clozapine and thioridazine, also increased dopamine turnover in the median eminence 16 hours after the first of two injections. These results provide evidence for the existence of hormonal neuronal feedback modulation of tuberoinfundibular dopaminergic neurons in contrast to the neuronal feedback modulation of nigrostriatal and mesolimbic neurons.


Centrally mediated intestinal stimulation by morphine. A study was designed to examine the effects of intraventricularly (i.vt.) administered morphine, apomorphine and epinephrine on the small intestine. Adult cats of either sex were implanted chronically with extracellular, monopolar electrodes at equal intervals along the entire small intestine. A collison cannula was placed in the left lateral cerebral ventricle in each animal. In animals that did not respond with emesis, morphine sulfate (200 micron g) administered i.vt. increased the incidence of spike potentials over the proximal three-quarters of the small intestine almost immediately. The response to i.vt. morphine was abolished by pretreatment with i.vt. naloxone HC1 (200 micron g) and was not obtained after peripheral (i.p.) injection of morphine at the same dose effective centrall. Now change in the number of spike potentials occure after i.vt. administration of two other potent emetic agents, apomorphine HC1 (200 micron g) and epinephrine HC1 (15O micron g), in animals that did not respond with emesis. The results suggest that the increased incidence of spike potentials after i.vt. morphine is a naloxone-sensitive, centrally mediated event not associated with activation of the central emetic mechanism.


Effect of L-dopa on plasma renin activity with and without inhibition of extracerebral dopa decarboxylase in dogs. The aim of the present study was to investigate the possibility that catecholaminergic pathways within the central nervous system play a role in the control of renin secretion. Plasma renin activity (PRA) was measured after intravenous administration of L-dopa with and without prior inhibition of extracerebral dopa decarboxylase by carbidopa (MK-486) in pentobarbital-anesthetized dogs in which changes in renal perfusion pressure were minimized by means of a suprarenal aortic clamp. When L-dopa (20 mg/kg ) was administered intravenously without carbidopa. PRA and blood pressure increased. In contrast, administration of L-dopa (20 mg/kg i.v.) after blockade of extracerebral, but not cerebral dopa decarboxylase by intravenous carbidopa (20 mg/kg), produced significant decrease in both PRA and blood pressure. Larger doses of l-dopa (30-50) mg/kg i.v.) also lowered both PRA and blood presure in three carbidopa-treated animals, whereas a smaller dose of L-dopa (10 mg/kg i.v.) significantly lowered blood pressure but not PRA. In dogs with both kidneys acutely denervated, L-dopa (20 mg/kg i.v.) with carbidopa lowered arterial pressure but did not consistently alter PRA. These data suggest that catecholamines formed within the central nervous system can act to lower renin secretion as well as blood pressure.


Blood and tissue levels of [14C]isosorbide dinitrate after oral and intravenous administration to rat. Rat blood and various tissues were analyzed for levels of isosorbide dinitrate (ISDN), an antianginal drug, after the administration of 14C-labeled compound. Unaltered [14C]ISDN was found in all tissues analyzed and in the circulating blood for up to 4 hours after p.o. or i.v. administration. These results clearly show that ISDN is not completely degraded in a single pass through the liver after either route of administration. ISDN concentration (nanograms of ISDN per gram wet weight of tissue) in vascular tissue were significantly greater than other tissues or the blood.


The pharmacology of verapamil. I. Elimination kinetics in dogs and correlation of plasma levels with effect on the eletrocardiogram. The elimination kinetics of verapamil, an experimental antiarrhythmic agent which inhibits slow-channel activity, have been studied in mongrel dogs after i.v. drug administration. The disposition of verapamil follows first-order kinetics and may be adequately described by a one-compartment model. After single i.v. doses of the drug, the overall elimination rate constant (mean +/-S.E.M.) was 0.0146 +/- 0.0021 min-1; the apparent volume of distribution was 4.47 +/- 0.40 liters/kg; and the total body drug clearance was 1244 +/- 113.4 ml/min. After longer i.v. infusions, the disposition kinetics were similar to those found with bolus dosing. A linear relationship was found between verapamil plasma concentrations and changes in atrioventricular conduction time, as estimated from the P-R interval of the surface electrocardiogram (r = 0.95, P less than .001). No changes were seen in the QRS duration of Q-T interval. These data show that the effect of verapamil of verapamil on slow-channel-dependent conduction in the heart is directly related to the concentration of the drug in plasma.


Ultrastructural changes in guinea-pig myocardium after acute ouabain treatment. Ultrastructural changes in the region adjacent to the nuclear pole were identified in the ventricular myocardium of ouabain-treated guinea pigs after 1 to 4 hours of treatment. Significant changes include expansion of the Golgi complex, an increase in the number of coated vesicles and an increase in the number of cytoplasmic particulates including glycogen particles and ribosomes. The coated vesicles appear to coalesce with the internal terminal regions of T-tubules and thereby may contribute to increase tubular mass or surface. In contrast to acute ouabain treatment, the morphologic change identified with the administration of another positive inotropic drug, isoproterenol, consists of some increase in cytoplasmic particulates, but no significant change in the Golgi apparatus or in the number of coated vesicles compared with control hearts. It is concluded that the administration of ouabain leads to activation of the Golgi complex, possibly associated with the synthesis of new T-tubular membrane components.


Testicular blood flow and a study of the testicular venous to arterial transfer of radioactive krypton and testosterone in the rhesus monkey. 1. Testicular blood flow (ml. 100 g(-1).min(-1); mean +/- S.E. of the mean) measured in monkeys by (133)Xe clearance was 15.9 +/- 1.2 (twenty-six estimations on three monkeys; six testes) within 15 min of anaesthesia and 7.5 +/- 0.8 (twelve estimates; four monkeys, eight testes), after 1-2 hr of anaesthesia; and, when measured by (85)Kr clearance in the second hour of anaesthesia was 9.1 +/- 3.7 (seven estimates; four monkeys, four testes). Testicular temperature was 32.9 +/- 0.2 degrees C (mean +/- S.E. of mean) when deep body temperature was 37.2 +/- 0.2 degrees C.2. Blood flow in the caput epididymidis was 27.4 +/- 2.1 ml. 100 g(-1).min(-1) (mean +/- S.E. of mean; four estimates).3. Radioactivity accumulated in the ipsilateral testis and epididymis but not in the contralateral tissues, during the infusion of (85)Kr saline into the testicular veins.4. During [(3)H]testosterone infusions into the testicular veins, radioactivity was consistently higher in ipsilateral testicular arterial plasma than in plasma withdrawn simultaneously from the aorta in four of five experiments with no difference in one. After two such infusions, the radioactivity was up to 5 times greater in the ipsilateral testis and epididymis than in the contralateral tissues.5. During one infusion of [(125)I]bovine serum albumin into the testicular veins, there was no accumulation of radioactivity in the ipsilateral tissues.6. Testosterone concentrations (ng.ml(-1); mean +/- S.E. of mean) in plasma from seven anaesthetized monkeys which were sexually experienced were: testicular vein 53.22 +/- 8.03 (eight estimates); testicular artery, 4.58 +/- 0.94 (14); saphenous vein, 3.81 +/- 0.68 (14). The corresponding values from four sexually inexperienced monkeys were 25.27 +/- 2.11 (12); 2.89 +/- 1.99 (12); aorta 2.76 +/- 0.57 (12).7. The results are discussed as evidence for vascular exchange of molecules between the testicular veins and artery in the spermatic cord.


Effects of replacing medium sodium by choline, caesium, or rubidium, on water and ion contents of renal cortical slices. 1. Renal cortical slices from rat, rabbit, and guinea-pig were incubated in media in which choline, caesium or rubidium replaced sodium.2. Slices of rabbit and guinea-pig renal cortex incubated in oxygenated choline Ringer decreased in volume initially and did not swell over 3 hr at 25 degrees C. There was a steady loss of potassium. Inhibition of metabolism (N(2) + 1 mM iodoacetamide) caused some swelling. Ouabain, 10 mM, in choline Ringer affected neither loss of potassium nor tissue water content.3. Slices of rat renal cortex similarly incubated in choline Ringer swelled over 3 hr at 25 degrees C whether or not metabolism was inhibited; ouabain (15 mM) affected neither tissue potassium loss nor tissue water content.4. Incubation in choline Ringer containing either 0.2 mMp-chloromercuribenzoic acid, or 1 mM ethacrynic acid increased the tissue water content of guinea-pig renal cortical slices.5. Depletion of cellular potassium (by preliminary incubation in oxygenated potassium-free sodium Ringer with 10 mM ouabain at 30 degrees C) resulted in increased tissue water content when rabbit renal cortical slices were subsequently incubated in oxygenated choline Ringer at 25 degrees C for 3 hr.6. There was no evidence of energy-dependent extrusion of water or ions from either equilibrated rat or rabbit renal cortical slices leached at 0.5 degrees C and then reincubated at 25 degrees C in choline Ringer.7. Rat and guinea-pig renal cortical slices leached at 0.5 degrees C and reincubated at 25 degrees C swelled in rubidium Ringer and in caesium Ringer. There was no evidence of energy-dependent water or ion extrusion when metabolism was restored after leaching in either of these media. Metabolizing rat slices but not guinea-pig slices swelled faster than slices whose metabolism was inhibited.8. These results lend no support to the mechano-chemical hypothesis which ascribes cellular volume regulation to a contractile mechanism squeezing isotonic extracellular fluid from the cells. Instead it is suggested that cellular water content in these experiments reflects the balance between the rate of loss of potassium (and chloride) from the cells and the rate of uptake of extracellular cation (and chloride) into the cells - these rates reflecting both the electrochemical potential gradients of the ions and membrane permeability to them. The implications in relation to the hypothesis of ouabain-insensitive cellular volume regulation are discussed.


Effects of sodium, potassium and calcium ions on the slow wave in the circular muscle of the guinea-pig stomach. 1. The contribution of Na, K and Ca ions to the generation of slow waves in the circular muscle of the guinea-pig stomach was studied.2. The slow waves had a lower, potential-independent (first) and an upper, potential-dependent (second) component. Reduction of the external Na prolonged the first component, but complete removal of Na depolarized the membrane and caused deterioration of the slow wave.3. Readmission of Na (5-10 mM) restored the slow wave; this action was not abolished by ouabain.4. Removal of K depolarized the membrane and slightly reduced the amplitude and duration of the slow waves. Readmission of K hyperpolarized the membrane and increased the amplitude and duration of the slow waves, particularly of the first component. Ouabain blocked the effects on the membrane potential, but not the effects on the slow waves.5. An increase in extracellular Ca prolonged the first component and reduced the frequency. Removal of extracellular Ca abolished the slow wave activity. Excess Ca enhanced, and low Ca reduced the effects of altering the concentrations of external K.6. It is concluded that the ouabain-sensitive Na-K pump may not be directly involved in generating slow waves, but that some other metabolic process is involved, which is regulated to a large extent by Ca, and possibly also by Na and K.


The effect of anaesthesia on the inhibition of pentagastrin-evoked gastric acid secretion induced by atropine in the rat. 1. In the anaesthetized, vagally intact rat, with a perfused gastric lumen, atropine produced a maximum inhibition of 60% of maximal pentagastrin-evoked gastric acid secretion. Sub-maximal pentagastrin-stimulated secretion was also inhibited by atropine.2. In the anaesthetized, vagotomized rat, with a perfused gastric lumen, atropine had no inhibitory effect on maximal pentagastrin-evoked gastric acid secretion.3. In the conscious fistula rat, atropine totally abolished both the basal gastric acid secretion and the maximal gastric acid secretion evoked by pentagastrin. In the anaesthetized chronic fistula rat, doses of atropine up to 1.6 mg.kg(-1) administered subcutaneously produced a maximum inhibition of 70% of maximal pentagastrin-evoked gastric acid secretion. Vagotomy did not affect the response to atropine.4. In the conscious Heidenhain pouch rat, doses of atropine up to 1.6 mg.kg(-1) administered subcutaneously produced a maximum inhibition of 70.9% of maximal pentagastrin-evoked gastric acid secretion. Both anaesthesia and vagotomy, alone or in combination, did not affect the response to atropine.


The distribution of alpha-bungarotoxin binding sites of mammalian skeletal muscle developing in vivo. 1. The distribution of alpha-bungarotoxin binding sites on embryonic and neonatal rat skeletal muscle fibres was determined by autoradiography. Most of the bungarotoxin binding could be inhibited by curare. This observation, together with the spatial distribution of toxin-binding sites, indicates that the distribution of bound toxin reflects that of acetylcholine (ACh) receptors on these developing muscle cells.2. At 15 days of embryogenesis, muscle fibres showed an essentially uniform distribution of receptors. By 16 days, many fibres showed an accumulation of receptors in their mid-region. This accumulation was at the same location as histochemically demonstrated cholinesterase activity.3. At 16 days ACh receptors were distributed over the entire length of the fibres, with a gradient of increasing density as the accumulation was appoached. The density of toxin binding sites in the accumulation was greater than the general level on 15 day cells, suggesting that the high junctional density does not develop solely by the loss of extrajunctional receptors.4. The accumulations of ACh receptors became more pronounced and circumscribed with embryonic development, and after birth the extent of the localizations appeared to follow the size of the neuromuscular junction. The extrajunctional receptor density decreased with development, and by 1 week after birth was undetectable by the methods used.5. The results suggest that the high junctional receptor density found on adult, innervated skeletal muscle fibres develops after the formation of the neuromuscular junction.


Sucrose absorption by the rat small intestine in vivo and in vitro. 1. The absorption of glucose and fructose derived from sucrose has been studied using in vitro and in vivo loops of the rat jejunum.2. At low sucrose concentrations (1 and 10 mM) glucose appeared in the serosal compartment of the in vitro preparation at a faster rate than fructose, but at high sucrose concentrations (50 and 100 mM) the rates of serosal transfer of the two sugars were similar. Glucose and fructose appeared in the mucosal compartment, with the rate of fructose appearance exceeding that of glucose, at all the sucrose concentrations studied.3. Phlorizin (5 x 10(-5)M) added to the mucosal medium of the in vitro preparation abolished the serosal transfer of glucose derived from 50 mM sucrose, and reduced that of fructose by 75%.4. In the absence of sodium ions, the in vitro preparation failed to transfer glucose and fructose derived from 50 mM sucrose, into the serosal compartment.5. Glucose was actively accumulated in the whole gut wall of the in vivo preparation to concentrations higher than those in the plasma at 50 and 100 mM, but not at 10 mM sucrose concentrations. Fructose was also actively accumulated to about half the extent of glucose, but reached tissue concentrations greater than those in the plasma, at each sucrose concentration.6. The whole wall concentrations of glucose and fructose derived from sucrose added to the lumen continued to rise when the blood supply to the in vivo preparation was terminated.7. No increase in the in vivo whole wall concentrations of glucose and fructose were detected when sucrose was added to the lumen together with concentrations of glucose sufficient to saturate the monosaccharide transport systems.8. The results favour the view that disaccharide hydrolysis and resulting hexose transfer are sequential, separate events.


Skin temperature during running--a study using infra-red colour thermography. Infra-red colour thermography has been used to visualize skin temperatures in two athletes standing and running in an outdoor environment at 20 degrees C and in a climatic chamber at 11 degrees C. Temperature distributions and changes have been recorded on film and analysed. Mean skin temperatures determined by this method have been compared with skin temperatures obtained with a probe thermocouple. During running, skin temperatures were higher over muscles than over other structures and the distribution differed dramatically from that observed before exercise. Regional mean skin temperatures obtained by thermography differed by up to 4 degrees C from those obtained with the thermocouple probe. Overall mean skin temperatures obtained by both methods agreed to within 1-5 degrees C.


Reduction of the duration of isovolumic relaxation in the ejecting left ventricle of the dog: residual volume clamping. 1. The individual effects of stroke volume and speed of ejection on the duration of the isovolumic relaxation phase were analysed in the canine left ventricle with a constant end-systolic residual volume.2. A new technique was employed to maintain the ventricular end-systolic residual volume at a desired constant value regardless of wide changes in stroke volume and speed of ejection in a given inotropic background.3. The duration of isovolumic relaxation, which was defined to be the time taken for ventricular pressure to fall from its end-systolic level to its 75, 50 and 25% levels, markedly decreased with increases in stroke volume. The reduction amounted to as much as 30-50% when stroke volume was increased from zero (isovolumic) to 20-25 ml.4. The degree of shortening of the duration of isovolumic relaxation was largely independent of changes in speed of ejection which ranged from about 100-800 ml./sec at a constant stroke volume of 15 ml.5. It was therefore concluded that stroke volume itself could be a major determinant of the duration of isovolumic relaxation.6. It was speculated that the mechanism of the observed phenomenon might be a manifestation of the uncoupling effect of muscle shortening on contractile state.


Electrophysiological study of the antiluminal membrane in the proximal tubule of Necturus: effect of inorganic anions and SCN-. 1. A study has been made of the effects of anionic substitutions on the electrical potential difference (p.d.) and conductance characteristics of the antiluminal (peritubular) membrane of the proximal tubule of Necturus kidney. The tubular lumina were filled with oil in order to minimize potential and conductance contributions from luminal membrane and from paracellular shunt pathway.2. Isosmotic substitutions, [A](o) for [Cl](o), produced the following average changes in membrane p.d. (mV): F(-) +1.7, BrO(3) (-) +0.1, Br(-) -4.5, ClO(3) (-) -5.2, I(-) -7.9, NO(3) (-) -12.1, ClO(4) (-) -17.8, SCN(-) -25.3.3. The amplitude of the depolarization caused by increase in K concentration (K-depolarization) in the peritubular perfusate was found to increase during perfusion of the tissue with ClO(4) (-) (by 78%), SCN(-) (45%), I(-) (23%), NO(3) (-) (20%), Br(-) (16%); it decreased with F(-) (by 17%).4. Comparison of membrane p.d. at peak K-depolarization in the control state (during KCl perfusion) with that obtained in the experimental state (during KA perfusion) was found to be more reliable than determination of bi-ionic potentials as a qualitative estimate of the permeabilities of the various anions (P(A)) relative to that of chloride (P(Cl)).5. Study of both peak K-depolarization p.d. and bi-ionic potentials yielded the following sequence for halide anion permeabilities: P(F) > P(Cl) > P(Br) > P(I). The peritubular membrane was found to be substantially more permeable to NO(3) (-), ClO(4) (-) and SCN(-) than to Cl(-).6. The sequence of membrane conductances during anionic substitutions was Cl(-) approximately BrO(3) (-) < Br(-) </= ClO(3) (-) < I(-) approximately F(-) < NO(3) (-) < ClO(4) (-) < SCN(-).7. From the changes in p.d. induced by K-depolarization, the absolute values of p.d. at peak K-depolarization and from the changes in membrane conductance induced by anionic substitutions, it may be inferred that Br(-), I(-), NO(3) (-), ClO(4) (-) and SCN(-) all increase P(K); and that F(-) increases P(Na) (though a smaller increase in P(K) cannot be excluded).


On the question of body fluid volume or sodium status influencing renin release. 1. The extent to which renin release is affected by simultaneous changes in body Na and body fluid volume was studied in six sheep. 2. The animals' water intake was restricted for 10-17 days after which they were offered solutions containing varying amounts of NaCl. 3. Plasma renin concentration (PRC) of water restricted sheep was 2-3 times normal. 4. The changes in PRC following drinking were inversely related to the amount of sodium consumed, Na excretion and plasma Na concentration. There was no correlation between the changes of PRC and of plasma volume in so far as the latter is reflected by alterations in plasma protein concentration. 5. We conclude that changes in renin release were related to the animals' handling of NA, and not to alterations in body fluid volume. 6. These findings are compatible with the proposition that renin release was mediated by a macula densa mechanism.


The pupillary, the intraocular pressure and the vasomotor responses to noradrenaline in rabbits. 1. A study has been made of the cause of the temporal disparity between the pupillary and intraocular pressure responses to noradrenaline applied topically. 2. Over a 5-day experimental period, the quantitative characteristics of the pupillary response to noradrenaline applied either once or several times daily remained essentially unchanged. In the same rabbits the delay in pressure response to noradrenaline on the first day was increased by a second application and, on subsequent days, multiple applications of noradrenaline induced a biphasic pressure response. 3. Intravenous phenoxybenzamine inhibited both the pupillary and the biphasic pressure responses to noradrenaline. Phenoxybenzamine applied topically inhibited the ocular hypertensive but not the hypotensive and pupillary responses. 4. Analysis of aqueous humour dynamics by manometric procedures showed that the hyper- and hypotensive responses were associated with increase and decrease, respectively, of the resistance to outflow of the aqueous humour.