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Biomedical subjects

R Lee

Publications and source records attributed to R Lee.

At least 379 records · Page 21Linked to original sources
PubMed1977

Antidepressants and pain: a review of the pharmacological data supporting the use of certain tricyclics in chronic pain.

There have been reports that tricyclic antidepressants, such as clomipramine (Anafranil), alleviate some forms of chronic pain in man. This paper examines and compares the pharmacological properties of centrally-acting analgesics and the tricyclic antidepressants, to establish a scientific basis for the observed clinical effects of the tricyclics. Opiates and tricyclic antidepressants share a number of pharmacological properties including activity in animal tests for antidepressant and analgesic activity. In doses which alone were not analgesic, clomipramine potentiated whilst maprotiline (Ludiomil) attenuated the analgesic activity of single doses of morphine in laboratory animals. However, when morphine and tricyclic agent were given repeatedly over several days, clomipramine enhanced or accelerated the onset of morphine tolerance, whereas maprotiline delayed tolerance. It is concluded that there is much experimental data to support the belief that tricyclics such as clomipramine may be useful in chronic clinical pain. Where an opiate is being administered chronically (for example in terminal pain) the concomitant administration of maprotiline may delay onset of tolerance.

Analgesics↗
PubMed1976

Inhibition by superoxide dismutase of methemoglobin formation from oxyhemoglobin.

The formation of methemoglobin from oxyhemoglobin in a solution containing photoreduced riboflavin and oxygen was inhibited by superoxide dismutase. The rate of the reaction was pH-dependent in the range of 6.8 to 7.8, increasing as the pH was reduced. Inhibition by superoxide dismutase was enhanced as the EDTA concentration increased and was dependent on enzymatic activity. Under conditions in which superoxide dismutase inhibition was incomplete, catalase inhibited the reaction but mannitol had no effect. The data support the mediation of methemoglobin formation by superoxide. The hypothesis is offered that superoxide anion reduced the heme-bound oxygen in oxygemoglobin by one electron, permitting the subsequent dissociation of ferrihemoglobin and peroxide. The ability of superoxide dismutase to inhibit the formation of methemoglobin may represent one of its functions in the mature erythrocyte.

Animals↗
PubMed1976

A comparison of the hemodynamic effects of inotropic agents.

This experimental study was conducted to compare and contrast the cardiovascular effects of the drugs most commonly used to alleviate low-cardiac-output syndrome. Twenty-five adult mongrel dogs were infused with sodium pentobarbital (60 mg/min) until their cardiac output fell to 50+/-5% of the average control values determined by thermodilution technique prior to pentobarbital infusion. The dogs were then divided into six groups, and one of the following agents or combinations of agents was administered to each group: isoproterenol, glucagon, dopamine, dobutamine, levarterenol and phentolamine, or levarterenol and nitroprusside. All drugs, except for glucagon and the combination of levarterenol and nitroprusside, produced an increase in cardiac output above the nonfailure baseline values. However, this increase was accompanied by an undesirable, pronounced tachycardia except when levarterenol was used simultaneously with phentolamine. Both dopamine and the combined infusion of levarterenol and phentolamine proved the most effective in restoring systemic arterial pressure to near baseline values, and both were able to increase renal blood flow above the failure baseline values. While renal blood flow remained elevated with all dosages of levarterenol and phentolamine, it tended to decrease with larger doses of dopamine. These experiments demonstrate that there are major advantages in the use of simultaneously infused levarterenol and phentolamine for control of low-cardiac-output syndrome: increased cardiac output without elevated peripheral vascular resistance, restoration of systemic arterial pressure and consequent improved coronary flow, absence of tachycardia, and augmented renal blood flow.

Animals↗
PubMed1975

The benefits of corticosteroids in endotoxic shock.

The experiments reported here were undertaken to study the effects of pharmacological doses of corticosteroids administered alone or in conjunction with prolonged (12-hour) assisted circulation in 22 dogs subjected to LD50-60 Escherichia coli endotoxin. The most striking findings were lengthened survival time, higher cardiac output, decreased fluid requirement, and minimal evidence of pulmonary congestion or injury in the animals treated with steroids only. Unexplained mesenteric infarction prematurely terminated the experiments in animals undergoing assisted circulation. The benefits of corticosteroids in experimentally induced endotoxic shock are clearly demonstrated in these experiments. Further studies are needed to clarify the supportive role of assisted circulation in endotoxic shock and to determine any possible advantage of hypothermia over normothermia during its course.

Animals↗
PubMed1975

On the homology of congruence subgroups and k(3)(z).

Let Gamma(n;p) be the congruence subgroup of SL(n;Z) of level p. We study the homology and cohomology of Gamma(n;p) as modules over SL(n;F(p)) and apply our results to obtain an upper bound for the order of K(3)(Z).

Journal Article↗
PubMed1975

The detection of carotenoid pigments in human skin.

Carotenoid pigments were extracted chemically from both epidermis and dermis obtained from non-carotenemic individuals at autopsy. Absorption maxima characteristic of beta-carotene were found in the extracts of specimens of epidermis following cantharidin application in volunteers made carotenemic by the ingestion of beta-carotene (180 mg/day for 10 weeks). These maxima were absent in the extracts of epidermis obtained from the volunteers before beta-carotene ingestion.

Carotenoids↗
PubMed1975

Surveillance of some infectious diseases among aircrew personnel in Southeast Asia.

A 2-year analysis of specimens among aircrew personnel in Southeast Asia is reported. Stool specimens were examined for intestinal parasites and enteric bacteria, blood smears for blood parasites, and sera tested for transaminases (SGOT) and antibodies to Entamoeba histolytica, Toxoplasma gondii, Chikungunya and Japanese encephalitis viruses, Rickettsia tsutsugamushi, Leptospira sp. and Pseudomonas pseudomallei. One to four specimens each were obtained from 537 adult males and 20 females. There were 56 subjects with intestinal parasites as follows: Giardia lamblia (3.8%), Endolimax nana (2.6%), Entamoeba histolytica (1.4%), Entamoeba hartmanni (0.9%), Entamoeba coli (0.7%), Trichiuris trichiura (1.7%), Ascaris lumbricoides (1.4%), hookworm (0.9%), and Clonorchis sinensis (1.2%). Two individuals had malaria, Plasmodium vivax (0.6%). Pathogenic enteric bacteria were isolated from seven stool specimens; Shigella groups B and D (0.9%), Salmonella paratyphi (0.3%), and Arizona group (0.9%). Significantly elevated SGOT levels were found in 0.9% and antibodies to Japanese encephalitis virus in 1.5%, to Rickettsia tsutsugamushi in 1.2%, to Pseudomonas pseudomallei in 0.3%, to Entamoeba histolytica in 0.9% and to Toxoplasma gondii in 10.1%. No antibodies were found to Chikungunya virus or Leptospira sp.

Aerospace Medicine↗
PubMed1975

Association of race, age, menopausal status, and cerumen type with breast fluid secretion in nonlactating women, as determined by nepple aspiration.

Biologic and physiologic factors associated with the availability of breast secretions by a nipple aspiration technique were investigated in 606 normal, non-lactating women. Data obtained on race, age, menstrual status, parity, contraceptive pill use, hormone use, and cerumen type indicated that availability of secretions was related to race, age, and menopause, and to genetic factors associated with apocrine bland function. Fluid aspirates were obtained most often from Caucasians (70.2% success), least often from Chinese (24.1% success). The percentage of successful aspirations declined in women over 50 years of age in all racial groups, but distinctly less so in Caucasians. Chinese and Japanese women with dry-type cerumen had a lower percentage of successful aspirations than those with wet type, which suggested that genetic factors may be associated with breast fluid secretion in nonlactating women.

Age Factors↗