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Biomedical subjects

C B Smith

Publications and source records attributed to C B Smith.

At least 181 records · Page 10Linked to original sources
PubMed1981

Quantitative evidence for cochlear, non-neuronal norepinephrine.

Endogenous norepinephrine was quantitatively measured in cochlear tissues of pigmented and nonpigmented animals by high-performance liquid chromatography and electrochemical detection. Epinephrine, dopamine and serotonin were not detected. The cochlear norepinephrine content of the pigmented animals was found to be more than double that present in corresponding albinos. Cochlear norepinephrine was only minimally depleted 48 h after surgical removal of the superior cervical ganglion. 12 h after administration of reserpine (5 mg/kg), cochlear norepinephrine was partially depleted. These results indicate that the norepinephrine located in the cochlea is probably not confined entirely to noradrenergic nerve terminals.

Adrenergic Agents↗
PubMed1981

Changes in protein synthesis underlying functional plasticity in immature monkey visual system.

Local rates of cerebral protein synthesis were determined in newborn rhesus monkeys subjected to either acute or chronic monocular visual deprivation. Chronic monocular deprivation resulted in decreased rates of protein synthesis in the laminae of the lateral geniculate nuclei innervated by the deprived eye whereas rates of protein synthesis were normal in geniculate laminae innervated by the functioning eye. Acute monocular deprivation produced no differential changes in rates of protein synthesis in any of the geniculate laminae.

Animals↗
PubMed1981

Risk factors for staphylococcal toxic-shock syndrome.

Fifty-two cases of toxic-shock syndrome that occurred in January 1, 1976 through August 31, 1980, were reported to the Utah State Health Department between February 1 and August 31, 1980. The annual attack rate for Utah based on a six-month surveillance period was 14.4 per 100,000 women ages 12-49 years. All cases were in women who had onset of illness within two days of menses. Potential risk factors were investigated with a case-control study utilizing 29 women hospitalized with toxic-shock syndrome and 91 neighborhood female controls. Nine of the 29 (31%) women reported recurrences of similar illness. Use of tampons (p = 0.012) and use of a single brand of tampon-Rely-during the month of illness (p less than 0.005, RR =6.11) were associated with a significantly increased risk of acquiring toxic-shock syndrome. More controls were sexually active than women who had toxic-shock syndrome (p less than 0.05, RR - 0.277). This epidemiologic investigation of toxic-shock syndrome in menstrual-age women has identified tampons generally and a single brand specifically as significant risk factors in acquiring toxic-shock syndrome.

Adolescent↗
PubMed1981

Androgen metabolism within the lobes of rhesus monkey prostate.

Testosterone metabolism was investigated in the caudal and cranial lobe of the rhesus monkey prostate. Analysis of the radiometabolites revealed that dihydrotestosterone and androstanediols are the main metabolites in the two lobes of the monkey prostate, suggesting that in this gland the main metabolic pathway is via the 5 alpha-reductive route. In contrast, the metabolic pathway for liver was found to be an oxidative one. The major metabolite in liver being androstenedione. There were no significant differences between the recovered radiometabolites in the two lobes of the prostate. The significance of the metabolic studies together with the differential uptake and receptor content of the two lobes of the monkey prostate have been discussed in relation to the zonal anatomy of the human prostate.

Animals↗
PubMed1981

Altered androgen metabolism in carcinoma of the prostate.

Testosterone metabolism was investigated in benign hypertrophied and malignant prostates using a tissue culture technique. The results demonstrated a distinct difference between the two types of tumour. The benign tissue was found to metabolize testosterone via a reductive pathway. The main radiometabolites were found to be dihydrotestosterone and androstanediols. On the other hand, the malignant tumours showed less ability to metabolize testosterone and the metabolism by these tumours was found to be an oxidative one, with the main metabolite being androstenedione.

Androstenediols↗
PubMed1981

Physiological and behavioral approaches to the study of the quasi-morphine withdrawal syndrome.

The effects of two benzazocines, UM-1037 and UM-1046, which produce a quasi-morphine abstinence syndrome in normal rhesus monkeys, were characterized by the use of the isolated guinea-pig ileal preparation and by a drug discrimination procedure in pigeons. These benzazocines produce a contraction of the ileum isolated from narcotic-naive guinea pigs similar to the narcotic antagonist-precipitated contraction of ilea isolated from morphine-pretreated animals. This effect is suppressed by morphine, and the suppression is reversed by naloxone. These benzazocines appear to stimulate the release of acetylcholine from ilea that have not been exposed to narcotics, and thus produce an effect similar to the release of acetylcholine produced by narcotic antagonists in ilea that have been exposed to morphine-like narcotics. The drug discrimination studies are also consistent with the involvement of cholinergic mechanisms in the behavioral effects produced by the benzazocines. In pigeons that have been trained to discriminate UM-1046 from saline, physostigmine, but not neostigmine, produces responses like those produced by UM-1046. In contrast, drugs from other pharmacological classes do not share discriminative stimulus properties with UM-1046. Thus, complementary evidence was obtained from both a physiological and a behavioral approach. The involvement of cholinergic pathways in the quasi-abstinence syndrome produced by UM-1037 and UM-1046 suggests that similar pathways might be active during narcotic abstinence.

Acetylcholine↗
PubMed1980

In vivo metabolic activity of a putative circadian oscillator, the rat suprachiasmatic nucleus.

The suprachiasmatic nucleus (SCN) has been proposed as a site for an endogenous circadian oscillator in mammals, since lesions of the nucleus abolish a wide spectrum of overt-circadian rhythms. To demonstrate that a directly measurable property of the SCN itself in intact (unlesioned) animals is affected by environmental light and exhibits circadian rhythmicity, we used the autoradiographic 2-deoxy-D-[14C]glucose method to determine glucose utilization of rat SCN under a variety of lighting conditions. Our experiments indicate an important role for the SCN in circadian rhythm organization, and we believe the deoxyglucose method will prove useful as a tool for better understanding the functions and mechanisms of circadian clocks. Key words: suprachiasmatic nucleus, circadian rhythm, 2-deoxy-D-[14C]glucose.

Animals↗
PubMed1980

Comparison of acute and chronic lithium treatment on 3H-norepinephrine uptake by rat brain slices.

The effects of lithium chloride, given IP in high (2.5-15 mEq/kg) and low (1.25 mEq/kg) doses twice daily, upon 3H-norepinephrine uptake and retention were examined with slices from four regions of the rat brain, namely brain stem, hypothalamus, parietal cortex, and caudate nucleus. Control uptake was significantly higher in slices from the caudate nucleus and lower in brain stem slices than in slices from hypothalamus or parietal cortex. With the higher doses, uptake increased significantly in all regions after 2 days of treatment and returned to normal by 7 days. With the lowest dose, uptake was increased after 7 days but normal at 14 days. Only in caudate slices was there a second elevation of 3H-norepinephrine uptake after 21 days of treatment, which returned to normal by 42 days. No other effects were observed during 70 days of treatment with lithium. The correlation between changes in 3H-norepinephrine uptake and plasma lithium levels was studied.

Animals↗
PubMed1980

Preparation and characterization of high-specific activity radiolabeled 50 S measles virus RNA.

A method is described to radiolabel measles virus RNA for hybridization studies. Tritiated nucleosides were added to the media of measles virus infected Vero cells and negative-strand (genome) RNA with a specific activity of 6 X 10(5) c.p.m./microgram was purified from viral nucleocapsids. 50 S RNA was the sole RNA present in nucleocapsids and self-annealed to 50% due to the presence of 25% 50 S plus-strands (anti-genomes).

Adenosine↗
PubMed1980

Effects of ageing on local rates of cerebral glucose utilization in the rat.

The effects of ageing on local rates of glucose utilization in 47 brain structures in resting conscious rats have been examined. Three age groups have been studied: young adult (4 to 6 months), middle-aged (14 to 16 months), and aged (26 to 36 months). The results show that ageing per se is associated with decreases in rates of glucose utilization in specific brain regions. The decreases were not progressive with age, probably because of the influence of a survival effect. Age-related pathological changes are known to occur in some of the brain structures in which decreases in rates of glucose utilization were found. Selective decreases were also found in the caudate-putamen, the parietal cortex and in structures associated with vision and audition. In these latter structures the changes may reflect reductions in local functional activity, perhaps due to decreased sensory input from the primary sensory organs.

Aging↗
PubMed1980

Effect of viral infections on pulmonary function in patients with chronic obstructive pulmonary diseases.

The effect of 100 separate viral infections of the respiratory tract on pulmonary function was evaluated prospectively over an eight-year period in 84 patients with chronic obstructive pulmonary diseases and in eight normal subjects. Some viral infections were associated with small acute declines in forced vital capacity and/or 1-sec forced expiratory volume of 25-300 ml. These declines were detectable only during the 90-day period after infection. The greatest abnormalities of pulmonary function followed infections with influenza virus, and the mean acute changes in 1-sec forced expiratory volume (-118.5 ml) were significantly greater than expected (-15.2 ml; P = 0.03). Smaller, statistically insignificant declines followed infections with parainfluenza virus, rhinovirus, adenovirus, and respiratory syncytial virus, and no changes were detectable after infections with coronavirus, herpes simplex virus, Mycoplasma pneumoniae, and Haemophilus influenzae. Long-term effects of influenza or other viral infections on the course of chronic obstructive pulmonary disease were not detected in this study population.

Acute Disease↗
PubMed1980

Lack of effect of oral ribavirin in naturally occurring influenza A virus (H1N1) infection.

A double-blind placebo-controlled trial of ribavirin was conducted in 97 young adult males naturally infected with influenza virus similar to A/Brazil/11/78 (H1N1). Ribavirin was given orally at a dose of 1,000 mg/day for five days beginning within 24 or 48 hr after onset of clinical influenza. The clinical signs and symptoms of influenza and quantitative viral shedding were the same in ribavirin- and placebo-treated groups. Ribavirin treatment was associated with significantly fewer fourfold or greater rises in antibody to influenza A viral antigen by the complement-fixation test, while rises in hemagglutination-inhibiting antibody titers occurred with equal frequency in both groups. The ribavirin-treated group experienced significant increases in bilirubin and in reticulocyte counts after onset of therapy.

Administration, Oral↗