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Biomedical subjects

P Cohn

Publications and source records attributed to P Cohn.

At least 19 recordsLinked to original sources
PubMed1996

Survival and yields of chromosome aberrations in hamster and human lung cells irradiated by alpha particles.

The effects of alpha-particle irradiation on hamster and human lung cells have been studied. In both cases two end points were taken, cell death and the induction of chromosome aberrations. The hamster cells were common stock V79 cells; the human ones were freshly derived from fetal material. For both types of cells, the survival curves could be described by straight lines in the conventional exponential plot, with values of D(o) of 0.78 and 0.37 Gy for the hamster and human cells, respectively. The rate of induction of chromosome aberrations could also be described by straight lines with slopes of 0.30 and 0.62 aberration per cell per gray. Thus, for this second end point also, it appears that human cells are twice as sensitive to the effects of alpha-particle irradiation as hamster cells.

Alpha Particles↗
PubMed1994

Drinking Water Contamination and the Incidence of Leukemia and Non-Hodgkin's Lymphoma.

>A study of drinking water contamination and leukemia and non-Hodgkin's lymphoma (NHL) incidence (1979-1987) was conducted in a 75-town study area. Comparing incidence in towns in the highest trichloroethylene (TCE) stratum (>5 microg/l) to towns without detectable TCE yielded an age-adjusted rate ratio (RR) for total leukemia among females of 1.43 (95% CI 1.07-1.90). For females under 20 years old, the RR for acute lymphocytic leukemia was 3.26 (95% CI 1.27-8.15). Elevated RRs were observed for chronic myelogenous leukemia among females and for chronic lymphocytic leukemia among males and females. NHL incidence among women was also associated with the highest TCE stratum (RR = 1.36; 95% CI 1.08-1.70). For diffuse large cell NHL and non-Burkitt's high-grade NHL among females, the RRs were 1.66 (95% CI 1.07-2.59) and 3.17 (95% CI 1.23-8.18), respectively, and 1.59 (95% CI 1.04-2.43) and 1.92 (95% CI 0.54-6.81), respectively, among males. Perchloroethylene (PCE) was associated with incidence of non-Burkitt's high-grade NHL among females, but collinearity with TCE made it difficult to assess relative influences. The results suggest a link between TCE/PCE and leukemia/ NHL incidence. However, the conclusions are limited by potential misclassification of exposure due to lack of individual information on long-term residence, water consumption, and inhalation of volatilized compounds.

Journal Article↗
PubMed1993

Infrared thermography in the detection and management of coronary artery disease.

Infrared thermography was used to measure and map precordial skin temperature in 60 patients undergoing elective coronary angiography; 9 patients were normal and 51 had coronary artery disease (CAD). Thermograms were graded by quartile area (zero to 4 plus) and magnitude of thermal asymmetry (recorded as degrees celsius). The presence, mean area and degree of thermal asymmetry were significantly greater in patients with CAD. Twenty-two patients subsequently underwent successful revascularization with angioplasty with a highly significant decrease in the presence, magnitude and degree of thermal asymmetry. The results demonstrate that CAD is associated with precordial thermal asymmetry. The area and magnitude of thermal asymmetry is greater in patients with CAD than in control subjects without angiographically significant CAD. Successful revascularization changed the asymmetric precordial pattern to a more symmetric one. Infrared thermography is a promising technique for the detection of CAD before and after revascularization.

Adult↗
PubMed1989

Ibuprofen and acetaminophen in the relief of acute pain: a randomized, double-blind, placebo-controlled study.

To determine the relative analgesic efficacy of ibuprofen 400 mg and acetaminophen 1000 mg, we conducted a single-dose, double-blind, placebo-controlled, randomized clinical trial using a standard assay for analgesic agents, the dental pain model. At regular intervals over 6 hours, 184 patients who had undergone dental impaction surgery rated pain intensity and relief on categorical scales and pain half-gone on a dichotomous nominal scale; a categorical overall evaluation was completed at the end of 6 hours. Both active agents were effective compared to placebo. Ibuprofen 400 mg was more effective than acetaminophen 1000 mg for Sum Pain Intensity Difference (SPID), Total Pain Relief (TOTPAR), sum pain half-gone, and overall evaluation (P less than .05 to P less than .001). The time-effect curves demonstrated a greater peak effect and longer duration of action for ibuprofen 400 mg compared to acetaminophen 1000 mg. Side effects were reported in five ibuprofen patients, 11 acetaminophen-treated patients, and seven placebo patients. Based on the results of this clinical study, we conclude that ibuprofen 400 mg is a safe and more effective analgesic than acetaminophen 1000 mg for patients with acute pain.

Acetaminophen↗
PubMed1989

Aldehyde dehydrogenase from human erythrocytes: structural relationship to the liver cytosolic isozyme.

Human red cell aldehyde dehydrogenase (ALDH) resembles the liver cytosolic isozyme in numerous physicochemical properties. This study was undertaken to establish the structural relationship between the erythrocyte and liver ALDH isozymes. The purified red cell ALDH was S-(14C)-carboxymethylated, and cleaved with trypsin. The tryptic digest was fractionated using Sephadex and reversed-phase chromatography. All peptides analyzed were identified within the liver cytosolic enzyme structure. In each case the sequence obtained corresponds exactly to a segment from the human liver cytosolic ALDH. Thus, the erythrocyte enzyme, by virtue of its chemical and structural identity with the liver cytosolic enzyme, may serve as a suitable peripheral enzyme model to understand the cause and mechanism of alcohol abuse-related changes in liver cytosolic ALDH that has been found to be reduced in alcoholics.

Aldehyde Dehydrogenase↗
PubMed1989

[New aspects of acetaldehyde metabolism in human tissues and erythrocytes].

Acetaldehyde, the active metabolite of ethanol oxidation, has been implicated to be mainly responsible for the diverse toxic effects of alcohol drinking. Aldehyde dehydrogenase (ALDH) catalyzes the oxidation of acetaldehyde in human liver and other organs. Impaired acetaldehyde metabolism by way of reduced ALDH activity may be the primary cause of tissue injury. Erythrocyte ALDH activity has been found to be decreased in alcoholics and returns to normal values on reducing the alcohol intake. The purpose of this study was to determine the interindividual variation in ALDH activity in different human tissues and erythrocytes. Results of the present study show that significant interindividual variation occurs in ALDH activity in different tissues. This variability in ALDH activity might explain the widely observed interindividual and ethnic/racial differences in alcohol intolerance and susceptibility to ethanol- and acetaldehyde-related tissue and organ damage. The study also confirms earlier observations that erythrocyte ALDH activity significantly varies in healthy individuals without alcohol abuse. This fact should be taken into consideration while evaluating the erythrocyte ALDH activity as a potential marker of alcoholism.

Acetaldehyde↗
PubMed1987

Impact of a screening family genogram on first encounters in primary care.

The family genogram is generally used when the clinical situation suggests that a family assessment is warranted. Owing to the prevalence of psychosocial problems in primary care, a screening genogram that is administered to patients routinely may have a significant impact on the care provided by clinicians. A randomized controlled trial was conducted to determine the influence of screening genograms on patients' initial visits to primary care physicians. The genograms captured more information about family structure, major life events, repetitive illnesses, and family relationships than did the physicians on their own. Nevertheless, the experimental and control groups were no different on the dependent variables: physician exploration of family issues, request for interviews with other family members and counseling or referral because of emotional problems. Although the power of the study alone could account for the lack of significant results, several other methodological issues, especially contamination of the control group, could have contributed to the negative results. The results of this study are similar to those of other psychosocial screening studies using similar designs. Hence, additional studies using alternative research protocols are indicated before rejecting the usefulness of screening genograms in primary care.

Data Collection↗
PubMed1984

Comparative efficacy of fenoprofen calcium and zomepirac sodium in postsurgical dental pain.

The relative analgesic efficacy of zomepirac sodium 100 mg and fenoprofen calcium 200 mg was evaluated in patients with pain due to surgical removal of dental impactions. This is the first study to make a direct comparison of their effectiveness. This study is especially important since zomepirac sodium was recently removed from the market as an analgesic for acute pain. Zomepirac sodium was extremely popular among clinicians and was considered the most effective of the peripherally acting analgesics. Patients were requested to take a single dose of study medication when they had moderate to severe pain. The study medications were identical in appearance and randomly allocated under double-blind conditions. The medication was evaluated over the next 4 hours according to subjective analgesic measurement scales. The primary measures of efficacy included total pain relief ( TOTPAR ), sum pain intensity difference ( SPID ), overall evaluation, and time to remedication . Of the 136 patients entered, 117 were included in the efficacy analysis. Both active agents demonstrated marked superiority to placebo (p less than 0.001) for all efficacy measures but were inseparable from each other. The mean analgesic efficacy values for both zomepirac sodium and fenoprofen calcium were almost identical. The nineteen subjects who reported side effects were evenly distributed among the three groups. No serious side effects occurred. The results of this study indicate that fenoprofen calcium 200 mg and zomepirac sodium 100 mg are equally efficacious, with similar onset, peak, and total analgesic effects.

Adult↗
PubMed1982

Macrophages of hypothalamic third ventricle. II. Immunological characterization of supraependymal cells in culture.

The question of whether hematogenous macrophages are present in the brain has remained incompletely resolved for many years. In the present study, a modified tissue culture system was employed, which enabled the isolation and visualization of cells which migrated from the surface of the hypothalamic third ventricle. Cultured cells were examined for macrophage characteristics, such as surface fine structure and cell spreading, phagocytic activity, nonspecific esterase activity, and the presence of cell surface receptors for the Fc portion of the immunoglobulin IgG. Markers of these characteristics were correlated cell by cell with light microscopy and scanning electron microscopy, utilizing both secondary and back-scattered electron imaging. Cells with all characteristic markers of the monocyte/macrophage line were identified and represent ventricular macrophages.

Animals↗
PubMed1981

Inhibition of lymphocyte capping and transformation by propranolol and related compounds.

1 The effects of propranolol on phytohaemagglutinin (PHA)-induced transformation of murine T lymphocytes and capping of anti-IgG on the surface of murine B lymphocytes have been examined. 2 A 50% inhibition of transformation was observed with 10(-5) M propranolol, whereas a higher concentration, of the order of 10(-3) M propranolol was required to inhibit capping by 50%. The (+)-and (-)-isomers of propranolol proved equipotent in these respects, and the relative potencies of selected analogues of propranolol (alprenolol, oxprenolol, metoprolol, practolol, and sotalol) coincided with their potencies as membrane stabilizers; however, lymphocyte transformation was consistently more sensitive than capping. 3 Similar effects were also seen with quinidine, chlorpromazine and lignocaine, and it was concluded that the inhibition of both lymphocyte functions was due to the membrane stabilizing actions of propranolol.

Adrenergic beta-Antagonists↗