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Biomedical subjects

J Thompson

Publications and source records attributed to J Thompson.

At least 757 records · Page 42Linked to original sources
PubMed1977

Evaluation of a radioimmunoassay for serum unconjugated estriol using commercial reagents.

A radioimmunoassay using a commercially available antiserum was evaluated for measurement of serum unconjugated estriol in pregnancy. The evaluation showed an inter-assay variance of 12.1%, intra-assay variance of 6.8%, sensitivity of 0.2-0.6 ng/ml (0.7-2.1 nmol/l), and average recovery of 85.3%. The assay is specific for unconjugated estriol, showing less than 1% cross-reactivity with estriol-3-sulfate and estriol-16-glucuronide. Normal limits were established from 7 to 40 weeks' gestation using 175 serum samples. No diurnal variation could be demonstrated at 8 a.m. and 3 p.m. Eighty-nine serum specimens and 82 urine specimens obtained from 18 high-risk pregnancies were within normal limits except in cases of intruterine fetal death, pre-eclampsia, and suspected placental sulfatase deficiency. Serial urinary estriol levels fluctuated as much as 75%, while serial serum samples varied by only 30%.

Adolescent↗
PubMed1977

Trials of influenza A/New Jersey/76 virus vaccine in normal children: an overview of age-related antigenicity and reactogenicity.

The total multicenter data from trials with inactivated monovalent influenza A/New Jersey/76 virus vaccine in 2,326 normal children were collected and summarized at Vanderbilt University (Nashville, Tenn.). These combined data provided the best measure of the relative antigenicity and reactogenicity of each manufacturer's vaccine. Children younger than 10 years of age were shown to have vaccine-associated reactions to doses of whole-virus vaccine containing as little as 50 chick cell-agglutinating units. Split-virus vaccines were well tolerated in doses eight times as high. No vaccine was satisfactorily antigenic in a single dose. A two-dose regimen of split-virus vaccine was antigenic, and this regimen was not associated with acute reactions.

Adolescent↗
PubMed1977

The repeatability of the measurement of aerobic power in man and factors affecting it.

The repeatability of measuring man's aerobic power was tested with regard to the influences from the following; 1. The immediate repeatability of the test. 2. The time sequences in which the progressive load increments are applied. 3. The subject's personal activities in the eighteen hours prior to the test. 4. The temperature of the laboratory during the test. 5. The time of day at which the test is carried out. 6. The day of the week on which the test is carried out. 7. The nervous state of the subject during the test produced by drugs affecting the autonomic nervous system. It was considered that aerobic power can be consistently measured in man as a standard control measurement if the following criteria are taken into account. The subject should be tested: 1. during the first few hours of his working day, 2. in an ambient temperature of not more than 4 degrees C above that of his normal working environment, 3. when he has been normally active during the previous 24 h, 4. when he is systematically free from drugs, particularly those affecting the nervous system, 5. when free from a previous severe stress, 6. at least 1 h after a cigarette or contact with a smoke aerosol.

Adolescent↗
PubMed1977

Effect of warfarin on the induction and course of experimental Staphylococcus epidermidis endocarditis.

The effect of warfarin treatment on an experimental Staphylococcus epidermidis endocarditis was studied. Warfarin was found to affect both the induction and course of the infection of catheter-induced endocardial vegetations. In warfarin-treated rabbits, larger bacterial inocula were needed to induce an infection, and the degree of infection of the vegetations was also significantly lower, eventually resulting in the total elimination of the bacteria from the vegetations. Thus, warfarin treatment seems to have an inhibitory effect on the induction and development of an S. epidermidis infection of the endocardium. The results differ from previous findings in studies done with Streptococcus anguis, where warfarin was found to have no effect on the induction or course of the infection of endocardial vegetations, which suggests that different mechanisms are involved in the pathogenesis of endocarditis caused by these two species of bacteria.

Animals↗
PubMed1977

Phosphoenolpyruvate and 2-phosphoglycerate: endogenous energy source(s) for sugar accumulation by starved cells of Streptococcus lactis.

In the absence of an exogenous energy source, galactose-grown cells of Streptococcus lactis ML3 rapidly accumulated thiomethyl-beta-D-galactopyranoside (TMG) and 2-deoxyglucose to intracellular concentrations of 40 to 50 mM. Starved cells maintained the capacity for TMG uptake for many hours, and accumulation of the beta-galactoside was insensitive to proton-conducting ionophores (tetrachlorosalicylanilide and carbonylcyanide-m-chlorophenyl hydrazone) and sulfydryl group reagents including iodoacetate and N-ethylmaleimide. Fluorimetric analysis of glycolytic intermediates in extracts prepared from starved cells revealed (a) high intracellular levels of phosphoenolpyruvate (13 mM; PEP) and 2-phosphoglycerate (approximately 39 mM; 2-PG), but an absence of other metabolites including glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-diphosphate, and triosephosphates. The following criteria showed PEP (and 2-PG) to be the endogenous energy source for TMG accumulation by the phosphotransferase system: the intracellular concentrations of PEP and 2-PG decreased with concomitant uptake of TMG, and a close correlation was observed between maximum accumulation of the beta-galactoside and the total available concentration of the two intermediates; TMG accumulated as an anionic derivative, which after extraction and incubation with alkaline phosphatase (EC 3.1.3.1) formed the original analogue; fluoride inhibition of 2-phospho-D-glycerate hydrolyase (EC 4.2.1.11) prevented the conversion of 2-PG to PEP, and uptake of TMG by the starved cells was reduced by 80%; and the stoichiometric ratio [TMG] accumulated/[PEP] consumed was almost unity (0.93). In cells metabolizing glucose, all intermediates listed in (a) and (b) were found. Upon exhaustion of glucose from the medium, the metabolites in (b) were not longer detectable, while the intracellular concentrations of PEP and 2-PG increased to the levels previously observed in starved cells. The glycolytic intermediates in (b) are all in vitro heterotropic effectors of pyruvate kinase (adenosine 5'-triphosphate:pyruvate 2-O-phosphotransferase, EC 2.7.1.40) from S. lactis ML3. It is suggested that the capacity of starved cells to maintain high intracellular concentrations of PEP and 2-PG is a consequence of decreased in vivo activity of this key regulatory enzyme of glycolysis.

Biological Transport↗
PubMed1977

The effect of metal ions on the activity of delta-aminolevulinic acid dehydratase.

The effects of lead, iron, copper, and zinc ions on delta-aminolevulinic acid dehydratase from red blood cell haemolysates in humans, both in the absence and presence of plasma proteins, have been investigated. delta-aminolevulinic acid dehydratase (ALAD) was not found to be a specific indicator of blood lead concentrations since it was also inhibited by copper and activated by zinc. Plasma protein protected the enzyme from both inhibition and activation. ALAD activity was found to be an indicator of the total metal ion concentration in the blood and was therefore considered to be of doubtful value in screening large populations for increased lead absorption.

Blood Proteins↗
PubMed1977

Conjoined thoracopagus twins.

A case of vaginally delivered stillborn female thoracopagus conjoined twins is presented. Each twin had a cleft lip and cleft palate. They shared a common pericardial sac and a common abdominal cavity. The liver was conjoined, and the small bowel was common to both twins. One twin was asplenic. Although the twins were monozygotic, their viscera were neither identical nor mirror-image to each other, and the visceral anomalies were unique to each twin. The hearts were fused, and communications existed between the circulations at the atrial and ventricular levels. One twin had single atrium, solitary (right) ventricle, malposed great arteries, pulmonary valvular atresia and infundibular stenosis, right aortic arch with aberrant left subclavian artery and with left ductus arteriosus, and atresia of the common pulmonary vein. The other twin had two atrial septal defects of the fossa ovalis and sinus venosus types, partial anomalous pulmonary venous connection, persistent left superior vena cava to coronary sinus, solitary (left) ventricle, malposed great arteries, and left aortic arch with aberrant right subclavian artery and with left ductus arteriosus. There was atrial and ventricular fusion. On hypothetical grounds, and in a comparable anatomic situation, salvage of one twin might be possible by surgical means, while the other twin was sacrificed.

Abnormalities, Multiple↗
PubMed1976

Reappraisal of skin flap closure for neonatal gastroschisis.

During the past 11 years, 18 infants with gastroschisis abdominal wall defects have undergone surgical repair at the UCLA Hospital. Sixteen infants had skin flap closure in infancy. A gastrostomy was performed on all infants, and peripheral intravenous hyperalimentation was used in 14 of the 18 infants. Sixteen of the 18 infants (89%) lived more than one year after surgical repair. Of these, 12 have undergone second-stage closure of the ventral hernia. Operative repair was greatly facilitated by forceful stretching of the abdominal musculature and milking of the bowel contents proximally into the stomach and distally out through the anus. The low morbidity and mortality of gastroschisis repair by primary skin closure, supplemented by intravensou hyperalimentation with late secondary ventral hernia repair, appear to justify continued use of this technique. Prosthetic materials probably should be reserved for reconstructing more complex abdominal wall defects.

Abdominal Muscles↗
PubMed1976

Vasectomy and vasovasostomy. II. A comparison of two methods of vasovasostomy: silastic versus chromic stents.

Twelve adult, bilaterally vasectomized dogs were used to compare two different procedures for reuniting the severed vas deferens. Approximately 5 months postvasectomy six dogs had vasovasostomies utilizing Silastic stents and the vasa deferentia of six additional dogs were rejoined with intravasal chromic stents. Ejaculates were subsequently obtained at 2-week intervals and evaluated for sperm count, motility, viability, and seminal ion concentrations. All of the dogs in which Silastic had been utilized as the stent had sperm reappear in the ejaculate, whereas only 40% of the dogs in which chromic catgut had been utilized had reappearance of spermatozoa. The over-all quality of the ejaculate was also better in the animals in which Silastic had been utilized. Testicular and epididymal histology was normal in most dogs of both groups, but three of the dogs with chromic stents in which the anastomosis had not been a success had abnormal histology, with reduced numbers of spermatocytes, spermatids, and spermatozoa. The data suggest that Silastic stents are better than chromic stents for vas reanastomosis. They also suggest that some dog testes react negatively to vasectomy and do not recover by 1 year postvasectomy when vas patency is not reversed.

Animals↗
PubMed1976

Clinical reactions and serologic response following inactivated monovalent influenza type B vaccine in young children and infants.

A monovalent, zonally purified, inactivated influenza B vaccine was administered to 29 children, 3 to 6 years of age, and 16 infants, 12 to 28 months of age, as a single dose of 0.25 ml containing 250 chick cell agglutinating units. The vaccine was both antigenic and well tolerated in the older group of preschool children. In the infants the vaccine was also antigenic but poorly tolerated clinically. Febrile reactions to 102 or greater were seen in 9 of the 16 infants, and two of these infants experienced a seizure following vaccination. The clinical reactions observed with the administration of influenza B vaccine in the dose used in this study would suggest significant limitations on its use in children under 3 years of age.

Antibody Formation↗
PubMed1976

Evaluation of a live, attenuated respiratory syncytial virus vaccine in infants.

Respiratory syncytial virus ts-1 is a live attenuated experimental vaccine which was administered intranasally to 25 infants 11 to 19 months of age. Clinical evaluation was carried out following a controlled, double-blind protocol which eliminated observer bias, assessed intercurrent illness, and was designed to detect virus transmission. At the low dose of virus of virus used (100 TCID50) 8 of the 25 recipients were successfully infected with RS virus ts-1 as determined by virus shedding or antibody response.

Antibodies, Viral↗
PubMed1976

Effect of warfarin on the induction and course of experimental endocarditis.

The effect of warfarin treatment on an experimental endocarditis was studied in rabbits. Warfarin had no effect on the induction of a Streptococcus sanguis infection in catheter-induced endocardial vegetations, and the course of this infection was also unaltered. However, warfarin treatment resulted in rapidly progressive bacteremia, probably due to impaired circulation in clearing organs such as the lungs, liver, and spleen. Warfarin also reduced the survival time of the infected rabbits, in which pulmonary edema and extensive lung hemorrhages may have been a contributory factor.

Animals↗
PubMed1976

Characteristics and energy requirements of an alpha-aminoisobutyric acid transport system in Streptococcus lactis.

Galactose-grown cells of Streptococcus lactis ML3 acculated alpha-aminoisobutyric acid (AIB) by using energy derived from glycolysis and arginine catabolism. The transport system displayed low-affinity Michaelis-Menten saturation kinetics. Using galactose or arginine as energy sources, similar V max and K m values for AIB entry were obtained, but on prolonged incubation the intracellular steady-state concentration of AIB in cells metabolizing arginine was only 65 to 70% that attained by glycolyzing cells. Efflux of AIB FROM PRELOADED CElls was temperature dependent and exhibited the characteristics of a first-order reaction. The rate of AIB exit was accelerated two- to threefold in the presence of metabolizable energy sources. Metabolic inhibitors including p-chloromercuribenzoate, dinitrophenol, azide, arsentate, and N, N'-dicyclohexylcarbodiimide either prevented or greatly reduced AIB uptake. Fluoride, iodoacetate and N-ethylmaleimide abolished galactose-dependent, but not arginine-energized, AIB uptake. K+ and Rb+ reduced the steady-state intracellular AIB concentration by approximately 40%, and these cations also induced rapid efflux of solute from actively transporting cells. Equivalent concentrations (10 mM) of Na+, Li+, or NH4+ were much less inhibitory. The proton-conducting ionophores tetrachlorosalicylanilide and carbonylcyanide m-chlorophenlyhydrazone abolished uptake and induced AIB efflux even though glycolysis and arginine catabolism continued at 60 and 140%, respectively, of control rates. A proton motive force is most likely involved in the active transport of AIB, whereas data from efflux studies suggest that energy is coupled to AIB exit in cells of S. lactis ML3.

Aminoisobutyric Acids↗