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Biomedical subjects

S N Bellur

Publications and source records attributed to S N Bellur.

14 recordsLinked to original sources
PubMed1994

Daytime sleepiness in insomnia: behavioral, biological and subjective indices.

We compared three measures of daytime sleepiness, sleep behavior (as measured by the multiple sleep latency test), a biological index of sleepiness (pupillometry) and subjective sleepiness (as measured by the Stanford Sleepiness Scale), in evaluating middle-aged individuals with psychophysiological insomnia (n = 20) or no sleep problem (n = 20). Subjects underwent polysomnography (PSG) and four multiple sleep latency test/pupillometry trials the following day. The results determined that neither behavioral, biological nor subjective indices distinguished these two groups. Differentiating the insomniacs into true insomniac (n = 14) and normal sleeping insomniac (insomniacs with sleep efficiency greater than 90%, n = 6) subgroups based upon PSG did not improve daytime discriminations. Furthermore, nighttime sleep experience, measured by either PSG or self-report, was not a strong predictor of these daytime indices among either insomniacs or noninsomniacs. The results of this study support the conclusions that insomniacs do not exhibit heightened levels of daytime sleepiness and that routine fluctuations in sleep exert minimal influence on daytime sleepiness among insomniacs and noninsomniacs. The former finding is likely due either to insomniacs satisfying their biological sleep need despite poor sleep or chronic physiological hyperarousal preventing both sleep and sleepiness.

Adult↗
PubMed1987

Cardiac regulation and depression.

Heart rate and heart rate regulation during sleep and wakefulness was studied in 28 patients with major depressive disorder and in 19 control subjects. Heart rate during quiet wakefulness was greater in the depressed group (H.R. = 73.04) than in the control group (H.R. = 65.35) (t = 3.06, p less than 0.005). Heart rate remained elevated throughout sleep in the depressed group as measured in Stage II (H.R. = 67.81) compared with the control group (H.R. = 60.84) (t = 2.49, p less than 0.01). Heart rate increased during movements in sleep in all subjects. The heart rate increases were attenuated in the depressed subjects compared with nondepressed controls (p less than 0.001). The effect was independent of sleep stage or baseline heart rate. All effects were independent of subject age. These findings point to a change in autonomic regulation of heart rate in depression.

Adolescent↗
PubMed1986

Low CSF protein concentration in idiopathic pseudotumor cerebri.

An inverse relationship between the cerebrospinal fluid (CSF) opening pressure and the corresponding protein value was found for patients with idiopathic pseudotumor cerebri who underwent their first lumbar puncture (LP) prior to the initiation of therapy. This relationship provides evidence for a pressure-dependent bulk flow absorption for CSF and also suggests that patients with high CSF pressures will have low CSF protein concentration.

Cerebrospinal Fluid Proteins↗
PubMed1983

EEG sleep in depressed adolescents.

Sleep disturbances, including disturbances in REM sleep, are common among depressed adults; it is unclear if the same is true for depressed adolescents. The authors monitored the sleep of 13 depressed adolescents and 13 normal age-matched controls. They found that, as with depressed adults, REM latency was significantly shorter and REM density significantly greater in the depressed group. There was no correlation between reduced REM latency and severity of depression, but there was a significant negative correlation between REM latency and age.

Adolescent↗
PubMed1981

Meningioma size. Its relationship to other diseases.

In an autopsy study of 7.345 cases from a 20-year period, 76 cases of meningiomas were noted. Meningiomas in the diameter range of 0.5 to 2.7 cm ("small" meningiomas) were significantly associated with extraneural malignancies and chronic renal failure as opposed to those in the diameter range of 2.8 to 10.5 cm ("large" meningiomas). These data suggest that small meningiomas may be nosologically distinct from large meningiomas. When discovered at autopsy, small meningiomas may not be "incidental" in the sense of being do novo phenomena of chance occurrence.

Humans↗
PubMed1981

Mental side effects of amantadine therapy: its spectrum and characteristics in a normal population.

A clinical survey of the mental side effects of prophylactic amantadine usage is reported. A total of 43 of 295 hospital employees taking the drug reported some mental side effects. While the majority of the side effects were alterations in mood (elevation or depression), there were also reports of delusions (7%), disturbances in memory and orientation (20%), and night terrors (33%). The author does not feel the findings warrant discontinuing the prophylactic usage of amantadine but do highlight the need for physician and patient education about its side effects.

Adult↗
PubMed1980

Arachnoidal cell hyperplasia. Its relationship to aging and chronic renal failure.

The biological implications of human arachnoidal cell hyperplasia are unclear. In a study based on 922 autopsies performed over a four-year period that investigated the conditions associated with arachnoidal cell hyperplasia, hyperplasia was found in 184 cases (study cases). The incidence of arachnoidal cell hyperplasia was found to increase linearly with advancing age. In a case-control design used to ascertain any other clinical associations, 22 of the study cases had comcomitant chronic renal failure, whereas only four in a control group matched for age at time of death had chronic renal failure. No other associations were observed. Arachnoidal cell hyperplasia seems to be an age-related phenomenon and shows a statistically significant association with chronic renal failure.

Adolescent↗
PubMed1979

Association of meningiomas with extraneural primary malignancy.

In an autopsy-based, case-control study of meningiomas over a 20-year period, there were 76 patients with meningiomas, and 20 of them also had an extraneural primary malignancy. In two control populations with autopsy-proved central nervous system (CNS) pathology (group I) and non-CNS pathology (group II), extraneural primary malignancies were seen in two patients in group I and in seven patients in group II. There was a high degree of statistical association between meningioma and extraneural primary malignancy (chi2 = 17.22, p less than 0.005 group I and chi2 = 7.61, p less than 0.01 group II). Screening of patients with meningioma for extraneural primary malignancy, and of patients with extraneural primary malignancy for meningioma are strongly indicated for the benefit of the patients as well as for further elucidation of the etiologic and temporal relationships between the two conditions.

Adolescent↗
PubMed1978

Effects of cholinomimetic agents on pentobarbital anesthesia in mice.

We evaluated the effects of physostigmine, choline chloride, and neostigmine on pentobarbital anesthesia in mice, both when given before and after the administration of pentobarbital. Neostigmine and choline chloride had no effects. Physostigmine shortened the onset of pentobarbital anesthesia when given before pentobarbital but had no effects on the duration of anesthesia. However, when given after pentobarbital it shortened the duration of pentobarbital anesthesia. It seems unlikely that the above effects of physostigmine are dependent on the cholinergic system in the nervous system since neostigmine and choline chloride were without action. However, they may be due to the effects of physostigmine on the blood brain barrier permeability to pentobarbital.

Anesthetics↗
PubMed1975

Opsoclonus: Its clinical value.

Although the exact site of pathologic involvement and the pathogenesis remain uncertain, opsoclonus is an invaluable clinical sign that in it alone may herald an occult systemic malignancy. A thorough systematic evaluation should be undertaken to exclude an occult neoplasm in any patient who presents with opsoclonus unaccompanied by any other clinical sign.

Brain Diseases↗
PubMedDate not supplied

Effects of carbachol and nicotine injected into the cerebral ventricles on electromyogram of conscious cats.

Carbachol and nicotine injected into the cerebral ventricles produced high amplitude and fast frequency activity in the electromyogram of conscious cats. Carbachol, much more than nicotine, caused bursts of such activity spaced at irregular time intervals accompanied by marked activity in the electrooculogram. In addition carbachol, but not nicotine, caused adynamia. The effect of nicotine laster 3-5 hr, while the effect of carbachol lasted up to 6 hr. The obtained results suggest that central muscarinic and nicotinic mediations are involved in the activation of the motor efferent system.

Animals↗
PubMedDate not supplied

Absorption characteristics of three phenytoin sodium products after administration of oral loading doses.

The absorption characteristics of three phenytoin sodium products given orally as loading doses in five healthy men were studied. Extended phenytoin sodium capsules, prompt phenytoin sodium capsules, and phenytoin sodium injection were administered in a randomized, crossover trial as single 18-mg/kg doses and as divided doses of 6 mg/kg every three hours for three doses. Each dose was given with 200 ml of water, and a two-week washout period followed each treatment. The maximum plasma concentration (Cmax), time to reach maximum plasma concentration, time to reach the lower end (10 mg/liter) of the therapeutic range, time to reach a plasma concentration greater than 15 mg/liter, and time within the therapeutic range were determined for each loading-dose regimen. Prompt phenytoin sodium capsules (prompt PHT) given in divided doses produced a mean Cmax of 22.0 mg/liter, which was significantly higher than that observed with any of the other loading-dose regimens. In addition, all subjects receiving prompt PHT in divided doses had plasma phenytoin concentrations of 10 mg/liter within six hours; only this treatment produced plasma concentrations greater than 15 mg/liter at nine hours in all subjects. Plasma concentrations remained within the therapeutic range (10-20 mg/liter) for 81 and 78% of the first 24-hour period for prompt PHT in divided and single doses, respectively. Adverse effects were minimal in all regimens. The prompt-release phenytoin sodium capsules used in this study may provide an alternative means for rapidly achieving therapeutic phenytoin concentrations in situations where i.v. administration is not indicated or practical.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗