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Biomedical subjects

R Waziri

Publications and source records attributed to R Waziri.

At least 37 records · Page 2Linked to original sources
PubMed1986

Drug effects on serine metabolism in psychiatric patients.

The question of whether neuroleptics can play a role in the hyperserinemia and low serine hydroxymethyltransferase (SHMT) activity previously reported in psychotic patients is investigated in this report. We find that in drug-free psychotics who had significantly higher plasma serine levels (PSL) and lower SHMT activity compared to nonpsychotics and normal subjects, more than 2 weeks of neuroleptic treatment decreased PSL and did not affect SHMT activity. This finding makes it unlikely that neuroleptics play an important role in the hyperserinemia of psychotics. The possible role of dietary factors in these patients is also discussed.

Antipsychotic Agents↗
PubMed1985

Metabolism of an ingested serine load in psychotic and nonpsychotic subjects.

Our previous studies have shown that in psychotics, the plasma serine level is abnormally high and that plasma serine hydroxymethyltransferase (which cleaves serine to glycine) activity is abnormally low as compared with that in nonpsychotic subjects. In this study, psychotic and nonpsychotic subjects ingested a large bolus of L-serine (4 mM/kg) at breakfast and blood was drawn before breakfast, 2 hr, 4 hr, and 6 hr after serine ingestion. Baseline serine and SHMT activity differentiated between psychotics and nonpsychotics with high degrees of significance (p less than 0.0001) and p less than 0.01, respectively). Plasma serine levels 2 hr after serine ingestion were significantly higher (p less than 0.01) in nonpsychotics as compared with psychotics. Elimination of serine in psychotics was bimodal and was significantly different from that of nonpsychotics (p less than 0.0079, Moses test). These findings provide additional evidence for abnormal serine metabolism in psychotic patients.

Age Factors↗
PubMed1985

Differentiation of psychotic from nonpsychotic depression by a biological marker.

In a study of fasting plasma serine levels (PSL) previously shown to be a biological marker for psychosis, we found significantly higher (P = 0.0008) PSL in 18 psychotic depressives when compared to 22 nonpsychotic depressives. Similarly the activity of the enzyme serine hydroxymethyltransferase (SHMT) which cleaves serine to glycine, was significantly lower (P less than 0.0001) in psychotics than in nonpsychotics. The difference between psychotic and nonpsychotic depressives were not attributable to age, sex or drug intake. This finding is in support of the hypothesis that these two types of depressions are qualitatively distinct from each other.

Adult↗
PubMed1984

Repetitive activity alters spike initiation locus and conduction velocity in Aplysia axons.

During a burst of spikes in the axon of neuron R2 of Aplysia, the spike initiation zone moves down the axon. The orthodromic latency of propagated spikes decreases as the trigger zone moves distally. At the same time, the conduction velocity of the spikes slows down, which leads to lengthening of interspike intervals, especially in remote regions of the axon. Similar timing changes are seen in the chemical and electrotonic postsynaptic potentials in some follower neurons of L10.

Action Potentials↗
PubMed1984

Serine metabolism and psychosis.

Plasma serine levels (PSL) in a group of patients with the diagnosis of major or atypical psychoses were significantly higher than in patients with nonpsychotic diagnoses or nonpatient controls. The enzyme serine hydroxymethyltransferase (SHMT), which metabolizes serine to glycine, showed abnormal activity in the psychotics compared to nonpsychotics and controls. PSL differentiated psychotics from nonpsychotics with a high (95%) degree of confidence. PSL were highly correlated to SHMT activity, suggesting that the hyperserinemia in psychotics was due to the abnormality of the enzyme. Previously psychotic patients who had been treated and were psychosis free still manifested abnormal high PSL and abnormal enzyme activity. These findings suggest that disturbed serine metabolism may be a biological marker and a vulnerability factor for psychosis.

Adult↗
PubMed1984

Arthritis associated with lithium toxicity: case report.

A 33-year-old man developed transient polyarthritis associated with lithium toxicity. The arthritic symptoms resolved after lithium was discontinued. A link between lithium, autoimmune mechanisms, and arthritis is postulated.

Adult↗
PubMed1983

Plasma serine to cysteine ratio as a biological marker for psychosis.

In a study of plasma amino acids in psychiatric patients, serine to cysteine (S/C) ratio was higher (S/C = 1.57 +/- 0.28) in 57 psychotics compared to 27 nonpsychotics (S/C = 1.06 +/- 0.23). This difference was highly significant at P less than 0.001. Psychotic patients were given a psychosis score (p score) of 1-4. The S/C ratios of individual patients were significantly correlated to their p scores (r = 0.65, P less than 0.001). S/C ratios were not related to diagnosis, age, sex, food intake and medications. When the initial S/C ratio and p scores of 22 patients were compared to their S/C ratio and p score at the time when they were improved and ready to be discharged, there was a concomitant fall both in S/C ratios and p scores suggesting the high S/C ratios may be indicative of a state rather than a trait characteristic. Our findings lead us to the conclusion that S/C ratios may provide a marker for the presence of psychosis and an index of its severity.

Adolescent↗
PubMed1983

The Capgras symptom and nondominant cerebral dysfunction.

Although the etiology of the Capgras symptom is still unknown, recent reports strongly support the role of organic factors. The authors present the case of a psychotic woman with Capgras symptoms who showed evidence of nondominant cerebral dysfunction, documented by neuropsychologic testing and electrophysiologic procedures. This observation lends credibility to the role of organic factors in the development of the Capgras phenomenon.

Adult↗
PubMed1980

Lateralization of neuroleptic-induced dyskinesia indicates pharmacologic asymmetry in the brain.

Since the two hemispheres of the human brain are asymmetrical for various cognitive and perceptual functions, a pharmacological as well as the known anatomical differentiation between the two hemispheres may underly the asymmetrical functions. A lateralization of the dyskinetic states consequent to long-term usage of large doses of neuroleptics would be indicative of a pharmacologic asymmetry in the brain hemispheres. Seven of eight right-handed psychiatric patients had greater right-than left-sided dyskinesias, a finding which pointed to pharmacological vulnerability in the left dominant hemisphere.

Adult↗
PubMed1980

Induction of 2',3'-cyclic nucleotide 3'-phosphohydrolase and morphological alterations in C6 glioma cells by dexamethasone, (3-butoxy-4-methoxybenzyl)-2-imidazolinone and prostaglandin E1.

Dexamethasone, RO20-1724 and prostaglandin E1 all induced morphological alterations and increased the glial specific enzyme 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) in rat C6 glioma cells in culture. Morphological alterations consisted mainly in the development of astrocytelike changes. Increases in dexamethasone-induced CNP activity was time dependent. Dexamethasone reduced cell growth rate, depending on the concentration employed.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1979

The mast cells of the mammalian central nervous system. IV. Culture of neurolipomastocytoid cells from rabbit and rat leptomeninges.

Leptomeningeal cells of 1-3 day-old rabbits and rats were cultured in Hamm's complete medium or in Eagle's Basal Medium (BME); the latter proved to be favorable for the present research. Three types of granular cell could be differentiated and isolated from other mesenchymal, neuronal and neuroglial elements. These three closely resembled (i) mast cells (MCs), (ii) neurolipomastocytoid cells (NLMs), and (iii) typical macrophages. Because MCs are absent from adult rabbit leptomeninges but present in the rat, it was concluded that the MC-like elements in rabbit cultures were derived from precursor cells normally capable of producing NLMs. The macrophages appeared typical, but their cell of origin, as that of the MCs and NLMs, could not be determined conclusively; a small round mononuclear cell might have given rise to all three cell types. NLMS, like MCs but unlike macrophages, are sensitive to the MC-discharger compound 48/80. This finding, plus the peculiar morphological features of the NLMs, in addition to evidence of a strong phagocytic activity by the macrophages, distinguishes the mature NLMs from mature macrophages as distinct cellular entities. It is closely concluded that NLMs in culture resemble ordinary MCs more closely.

Animals↗
PubMed1978

The Capgras phenomenon: cerebral dysfunction with psychosis.

A psychotic woman with Capgras symptoms is presented in whom evidence of cerebral dysfunction is documented both by neurophysiological and neurophysiological findings. The possible etiological aspects of these symptoms are discussed. The main conclusion arrived at is that Capgras symptoms cannot be explained either on the basis of cerebral dysfunction alone or on the basis of a psychosis alone. The simultaneous presence of cerebral dysfunction and psychosis is necessary for the development of symptoms.

Adult↗
PubMed1978

Depression and hemispheric functions: changes associated with unilateral ECT.

Nine depressed patients received ECT to the dominant (left) side along with nine matched depressed patients who received ECT to the non-dominant (right) side. Neuropsychological tests showed that the right hemispheric functions were more frequently abnormal as compared to left hemispheric (dominant) functions in the pre-ECT tests. ECTs delivered to either the right or left side improved right hemispheric functions when the depression was ameliorated. This study indicates that in depression right hemispheric functions are initially disturbed and ECT, instead of being deleterious to these functions, tends to improve them.

Depression↗