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Biomedical subjects

J W Warren

Publications and source records attributed to J W Warren.

At least 127 records · Page 7Linked to original sources
PubMed1980

Kinetics of a carbamazepine-ethosuximide interaction.

Carbamazepine and ethosuximide are used together to treat epileptic mixed-seizure patterns. Since carbamazepine has been shown to induce drug-metabolizing enzyme(s) in the liver, it follows that carbamazepine may alter ethosuximide disposition. Six normal subjects took one 250-mg ethosuximide capsule twice each day for 55 consecutive doses (study days 1 to 28) and one 200-mg carbamazepine tablet each evening from study days 11 to 27. Plasma samples were collected on study days 10, 17, 21, and 28. Mean steady-state concentrations of ethosuximide declined by 17% from a preinduction (study day 10) level of 32.2 +/- 5.6 micrograms/ml to a postinduction level of 26.8 +/- 5.2 micrograms/ml on study day 28. Ethosuximide clearance increased (alpha = 0.05) between study days 10 and 28 from 0.664 +/- 0.120 to 0.800 +/- 0.0154 l/hr. The time course of induction was analyzed using a kinetic induction theory. Ethosuximide half-life was lowered from mean - 53.7 +/- 11.5 hr (before induction) to mean = 44.6 +/- 10.7 hr (after induction); the difference between some subjects was large. These data show that ethosuximide disposition is altered by carbamazepine.

Adult↗
PubMed1979

Workshops enhance role of volunteers.

Educational workshops were developed to enrich volunteers' services to a large metropolitan hospital. Staff also benefit by acquiring useful input from the volunteers.

Chicago↗
PubMed1979

Bat-associated histoplasmosis in Maryland bridge workers.

An epidemic of acute prolonged febrile respiratory disease affecting nine of 19 workers on a Maryland State bridge maintenance crew was diagnosed as histoplasmosis by serologic testing in all and by isolation of the organism in one. In our investigation, it was revealed that work on a particular bridge was associated with disease. Culture of bat guano from the site two months later revealed H. capsulatum. Four previously uninfected epidemiologic investigators also became ill with histoplasmosis following collection of soil and bat guano. This outbreak reveals that bats and bat guano are a source of histoplasmosis, suggests that only brief exposure is necessary for acute infection and reemphasizes that histoplasmosis is not confined to the midwestern states.

Animals↗
PubMed1978

Antibiotic irrigation and catheter-associated urinary-tract infections.

To investigate the efficacy of antibiotic irrigation in preventing catheter-associated urinarytract infection, we carried out a randomized controlled trial of a neomycin-polymyxin irrigant administered through closed urinary catheters. Eighteen of 98 (18 per cent) of the patients not given irrigation became infected, as compared with 14 of 89 (16 per cent) of those given irrigation, yielding a mean daily incidence of 5 per cent in each group. The distribution of organisms and their antibiotic sensitivities differed in the two groups, the organisms from the patients with irrigation being more resistant. Disconnections of the catheter junctions were associated with high rates of infection. The rate of disconnections of the junctions in the group given irrigation was almost twice that of the control group because of the presence of the extra junction on overall infection rate represents the result of two opposing phenomena: the increased entry of organisms and the suppression of a portion of them.

Adult↗
PubMed1978

Bacteriuria in a population-based cohort of women.

A survey for bacteriuria was conducted in a community-wide, unselected population of women 16--69 years old. The overall prevalence of bacteriuria was 3.5%. The prevalence of bacteriuria increased with age with a linear trend, but with a significant nonlinear component as well. Bacteriuria was associated with parity after correction for the effects of age. Current symptoms of dysuria and a history of previous urinary tract infection were slightly but significantly more common in women with bacteriuria. The population described should serve as an adequate base for continuing studies of the possible consequences of bacteriuria.

Adolescent↗
PubMed1977

Drug migration during drying of tablet granulations I: effect of particle size of major diluent.

Migration of a water-soluble drug, propoxyphene hydrochloride, during drying of tablet granulations was studied. Wet granulations of the drug were prepared using lactose as the major diluent and corn starch as a disintegrant. Particle-size fractions of lactose ranging from 53 to 177 micron in diameter were employed in different granulations to examine the effect of particle size of the major diluent on drug migration. Determination of drug concentration at various depths in a dried granulation bed was accomplished by using a drying cell consisting of four layers. A numerical coefficient of migration was developed to compare the extent of drug migration in the various lactose granulations. Migration increased with decreasing particle size of the major diluent, lactose. Two factors that may contribute to increased migration with smaller particles are increased entry suction due to decreased intragranular capillary size and increased intergranular contact area.

Chemistry, Pharmaceutical↗
PubMed1977

Drug migration during drying of tablet granulations II: effect of binder solution viscosity and drying temperature.

The effect of binder solution viscosity and drying temperature on the integranular migration of propoxyphene hydrochloride was studied. Wet granulations containing the drug were prepared using binder solutions with viscosities ranging from 1 to 1000 cps. Temperature studies were conducted using granulations prepared with a 3-cps binder solution and dried at 40, 50, 60, 70, and 80 degrees. Drug migration decreased with increased binder solution viscosity, and insignificant migration occurred in granulations prepared with binder solutions having apparent viscosities above 90 cps. No significant effect on intergranular drug migration was observed within the drying temperature range studied. Tablets compressed from a granulation in which drug migration was high showed a greater tablet-to-tablet drug content variation than a granulation with lower migration, even though each dried granulation was thoroughly mixed before tableting.

Calcium Phosphates↗
PubMed1976

The concepts of sensitivity, specificity and accuracy in evaluation of electrocardiographic, vectorcardiographic and polarcardiographic criteria.

The concepts sensitivity and specificity are critically evaluated in the light of case studies drawn from electrocardiographic literature. These terms are often misused, and the meaning of these elementary statistical concepts is often misunderstood in studies on ECG, VCG and PCG criteria. Specificity figures reported in literature commonly refer to the fraction of true negatives with a negative test in normals. Limiting the test to two-group analysis and eliminating other disease categories tend to give overoptimistic values for specificity and diagnostic accuracy in general. It is pointed out that various performance indices for diagnostic accuracy depend heavily on the composition of the test groups and the fraction of test cases in each group. Sensitivity and specificity appear inadequate performance indices for evaluation of event detection schemes such as classification of ectopic beats. Alternative performance indices are considered, including the error ratio, association index, accuracy of positive test, accuracy of negative test, and overall diagnostic accuracy. Increased utilization of simple statistical tests for significance estimation in ECG criteria evaluation is suggested. The development and application of better diagnostic performance evaluation schemes based on concepts of cost of misclassification, entropy and information is encouraged.

Arrhythmias, Cardiac↗
PubMed1975

Hepatitis B in Nuremberg, Germany. Epidemiology of a drug-associated epidemic. Among US Army soldiers.

Beginning in 1971, acute viral hepatitis was epidemic among US soldiers stationed in Europe, with a total of over 8,700 cases reported between 1971 and 1974. Hepatitis B surface antigen (HBsAg) determinations suggest a predominance of hepatitis B. In the Nuremberg area, primary association was with the illicit use of drugs. This association was demonstrated by a chronologic relationship between measurable community drug use and the number of hepatitis admissions three to six months later and by a case-control study. Parenteral drug use and, to a lesser degree, cannabis smoking appeared to be factors in disease transmission. Sharing of illicit drugs with a hepatitis contact, whether parenterally or orally, was associated with increased risk of contracting the disease.

Acute Disease↗
PubMed1975

Double blind trial of L-dopa in chronic schizophrenia.

A double blind study in 28 patients with chronic schizophrenia was carried out comparing L-dopa (up to 1250 mgm daily) with placebo (both groups continuing to receive regular neuroleptic medication) over a six week period. Assessments by the psychiatrists and psychologist using Rockland and Pollin Rating Scale showed differential improvement of insignificant proportions but the nurse's ratings showed clearly significant improvement in the subject group.

Adult↗
PubMed1968

Infrared receptors in the facial pits of the Australian python Morelia spilotes.

There is a series of pits in the scales of the rostrum and posterior portion of the lower lips in some pythons and boas. In the Australian python Morelia spilotes, these pits are innervated by the maxillary and mandibular branches of the trigeminal nerve. Structural and neurophysiological evidence indicate that in the pits there are receptors that function as detectors of radiant heat flux.

Action Potentials↗