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Biomedical subjects

V Patel

Publications and source records attributed to V Patel.

At least 109 records · Page 6Linked to original sources

The pathways to primary mental health care in high-density suburbs in Harare, Zimbabwe.

The pathways to care for mental illness are diverse and are dependent on sociocultural and economic factors. The objective of this study was to describe the pathways to primary care for patients with common mental disorders in Harare. One hundred and nine consecutive patients with conspicuous psychiatric morbidity identified by general nurses in three primary health care clinics (PHC) and by four traditional medical practitioners were interviewed with the Pathways to Care Schedule. Other than those patients with an acute illness, most patients consulted more than one care provider; three-quarters of those with a history of prior consultations had consulted both traditional and biomedical care providers. Biomedical care providers were the most common first care provider consulted; if this treatment failed, then patients tried other biomedical or traditional care providers. Different factors operated in the decision-making process in choosing between consulting biomedical and traditional care providers. Traditional care providers provided explanations more often than biomedical care providers; explanations given were most often spiritual. Injectable treatments were often prescribed for mental illness, especially by private general practitioners (GPs). Such treatments, and many oral treatments, were non-specific. Dissatisfaction with consultations was most commonly due to lack of symptomatic improvement. The costs of consultation were highest for private GPs, general hospitals and traditional healers; faith-healers, PHCs and hospital psychiatric departments were the cheapest.

Adolescent↗

Synaptic exocytosis of dense-core vesicles in blue crab (Callinectes sapidus) stomach muscles.

Neuromuscular terminals of a single motoneuron to four muscles (CPV7a, GM5a, CV2, and CV3) in the stomach of the blue crab Callinectes sapidus showed structural evidence for the exocytotic release of dense-core vesicles exclusively at synapses. The primary evidence was the appearance of dense cores in the synaptic cleft, accompanied by indentations of the presynaptic or postsynaptic membrane. In their simplest form, these consisted of an omega-shaped figure of the presynaptic membrane enclosing one dense core, denoting release of a single dense-core vesicle. A larger indentation of the presynaptic membrane enclosing several dense cores denoted multiple release. A more complex form of multiple release was where the presynaptic membrane was normal, but the postsynaptic membrane elaborated into a sac projecting into the granular sarcoplasm and filled with dense cores. The postsynaptic sac in some instances was compressed into a thin, fingerlike extension, which lacked dense cores and, at its distal end, separated into small cisternae, suggesting a mechanism for membrane recycling. Profiles depicting single and multiple releases of dense-core vesicles were found more frequently at neuromuscular terminals that release relatively large amounts of transmitter with a single stimulus, such as CV2 and CV3, compared to those releasing smaller amounts, such as CPV7a and GM5a. The disparity in release sites among the four muscles of this single motor unit and the fact that many of the multiple-release figures were closely adjacent to the active zones for transmitter release suggest a possible modulatory role for dense-core vesicles in synaptic transmission. Such modulation may be long lasting, as implied by the postsynaptic sacs, which may permit prolonged release of the contents of their dense cores into the synaptic cleft. This is in keeping with the functional role of these stomach muscles, which is to be continuously active for long periods of time.

Animals↗

Structural-functional differences of a crab motoneuron to four stomach muscles.

A motor unit in the stomach of the blue crab, Callinectes sapidus, consists of four separate muscles involved in different aspects of the trituration and filtering of food. Motor nerve terminals to two of the muscles (CPV7a and GM5) release small amounts of transmitter (low-output) while those to the other two muscles (CV2 and CV3) release between three and five-fold greater amounts (high-output). Structural features underlying the disparity in synaptic strength were analysed with thin serial-section electron microscopy. Nerve terminals were similar in their volume percent of mitochondria, clear vesicles and dense core vesicles among the four muscles. This was also the case for the number and size of synaptic contacts. However, presynaptic dense bars representing active zones were longer and occurred more frequently at high-output synapses than at low-output ones. High-output synapses were also characterized by the close spacing of adjacent dense bars. The longer and more closely spaced dense bars at high-output synapses would be factors in the generation of larger synaptic potentials in these terminals compared to their low-output counterparts. Other factors, however, need to be considered to fully account for the physiological differences in synaptic strength among the four muscles.

Animals↗

The Shona Symptom Questionnaire: the development of an indigenous measure of common mental disorders in Harare.

The objective of this study was to develop an indigenous measure of common mental disorders (CMD) in the Shona language in Zimbabwe. Ethnographic and qualitative studies elicited idioms of distress of mental disorder leading to the preliminary Shona Symptom Questionnaire (SSQ), and items from the Self-Report Questionnaire (SRQ) were added to it. The 56-item Preliminary Shona Symptom Questionnaire (PSSQ) was administered to 302 randomly selected primary care attenders, of whom 100 were classified as cases on the basis of agreement between care provider assessment and a psychiatric interview. Discriminant analysis identified 14 items that were the strongest predictors of mental disorder. The 14-item SSQ has a high level of internal consistency (Cronbach's alpha = 0.85). The items are a mixture of emic and etic phenomena. The total score correlates strongly with patients' self-assessment of the emotional nature of their illness. Satisfactory specificity and sensitivity occurred at a cut-off point of 7/8. The SSQ is the first indigenous measure of mental disorder developed in sub-Saharan Africa to have included idioms or distress of primary care attenders and involved patients consulting traditional medical practitioners. It promises to be a useful instrument for epidemiological and clinical research. The methodology used is an innovative way of combining etic and emic methods in the evaluation of CMD.

Adolescent↗

Pheochromocytoma: effect of nonionic contrast medium in CT on circulating catecholamine levels.

PURPOSE: To study the catecholamine-releasing effect of peripheral intravenous administration of the nonionic contrast medium iohexol in patients with pheochromocytomas. MATERIALS AND METHODS: Ten patients (eight women, two men; mean age, 44 years; age range, 25-70 years) with pheochromocytomas and related tumors and six healthy volunteers (five men, one woman; mean age, 31 years; age range, 27-35 years) were examined. Plasma catecholamine levels were measured at intervals for 60 minutes after the injection of 0.9% saline or iohexol on 2 separate days. All 10 patients intravenously received the specific alpha-adrenergic blocker phenoxybenzamine hydrochloride (0.5 mg/kg in 250 mL of 5% dextrose infused over 2 hours) 24 hours before iohexol-enhanced computed tomography. RESULTS: There was no statistically significant increase in epinephrine or norepinephrine levels in the patients or the control subjects. CONCLUSION: While it may be prudent to administer oral alpha- and beta-adrenoceptor antagonists in all patients with a biochemically proved pheochromocytoma to control their symptoms and to prevent a spontaneous adrenergic crisis, specific blockade may not be required before contrast medium-enhanced scanning with iohexol. Although the sample size of this study is relatively small, the results do suggest that in an incidentally detected, clinically silent adrenal mass that may or may not be hypersecreting, the nonionic contrast medium iohexol may be used for scanning without blockade.

Adrenal Gland Neoplasms↗

Common mental disorders in primary care in Harare, Zimbabwe: associations and risk factors.

BACKGROUND: This study aimed to investigate the associations for common mental disorders (CMD) among primary care attenders in Harare. METHOD: This was an unmatched case-control study of attenders at primary health clinics, general practitioner surgeries and traditional medical practitioner clinics; 199 cases with CMD as identified by an indigenously developed case-finding questionnaire, and 197 controls (non-cases), were interviewed using measures of sociodemographic data, disability, care-giver diagnoses and treatment, explanatory models, life events and alcohol use. RESULTS: CMD was associated with female gender (P = 0.04) and older age (P = 0.02). After adjustment for age, gender and site of recruitment, CMD was significantly associated with chronicity of illness; number of presenting complaints; beliefs in "thinking too much" and witchcraft as a causal model; economic impoverishment; infertility; recent unemployment; an unhappy childhood for females; disability; and consultations with traditional medical practitioners and religious priests. CONCLUSIONS: Mental disorders are associated with female gender, disability, economic deprivation, and indigenous labels of distress states.

Age Factors↗

Low-density lipoprotein stimulated peroxide production and endocytosis in cultured human endothelial cells: mechanisms of action.

The effects of arachidonic acid metabolism and NADPH oxidase inhibitor on the hydrogen peroxide (H2O2) generation and endocytotic activity of cultured human endothelial cells (EC) exposed to atherogenic low-density lipoprotein (LDL) levels have been investigated. EC were incubated with 240 mg/dl LDL cholesterol and cellular H2O2 production and endocytotic activity measured in the presence and absence of the arachidonic acid metabolism inhibitors, indomethacin, nordihydroguaiaretic acid, and SKF525A, and NADPH oxidase inhibitor, apocynin. All inhibitors, with the exception of indomethacin, markedly reduced high LDL-induced increases in EC H2O2 generation and endocytotic activity. EC exposed to exogenously applied arachidonic acid had cellular functional changes similar to those induced by high LDL concentrations. EC incubated with 1-25 uM arachidonic acid had increased H2O2 production and heightened endocytotic activity. Likewise, EC pre-loaded with [3H]arachidonic acid when exposed to increasing LDL levels (90-330 mg/dl cholesterol) had a dose-dependent rise in cytosolic [3H]arachidonic acid. The phospholipase A2 inhibitors, 4-bromophenacyl bromide and 7,7-dimethyleicosadienoic acid, markedly inhibited H2O2 production in EC exposed to 240 mg/dl LDL cholesterol. These findings suggest that arachidonic acid contributes mechanistically to high LDL-perturbed EC H2O2 generation and heightened endocytosis. Such cellular functional changes add to our understanding of endothelial perturbation, which has been hypothesized to be a major contributing factor in the pathogenesis of atherosclerosis.

Acetophenones↗

P2 purinoceptor-stimulated conversion of arginine to citrulline in bovine endothelial cells is reduced by inhibition of protein kinase C.

Bovine aortic endothelial cells contain two coexisting receptors for extracellular ATP, named the P2Y and P2U purinoceptors. Previous studies have shown that these receptors are linked to phospholipase C in a manner that is modulated in part by protein kinase C (PKC). In this study, we investigate the influence of PKC in the regulation of endothelial nitric oxide synthase (NOS) by these two purinoceptors. Activation of either P2Y or P2U purinoceptors by either 2-methylthio-ATP or UTP, respectively, stimulated the formation of [3H]-citrulline in [3H]-arginine-labelled cells in a concentration-dependent manner. This stimulation was sensitive to inhibition by NG-nitro-L-arginine. Ten minutes of pretreatment with the PKC activator tetradecanoyl phorbol acetate (TPA) failed to affect NOS activity, either alone or when stimulated with 2-methylthio-ATP or UTP. However, under these conditions TPA caused almost complete translocation of PKC-alpha from the cytosol to the membrane. Ten minutes of pretreatment with the PKC inhibitor Ro 31-8220 significantly inhibited the agonist-induced stimulation of NOS. These results show that both P2Y and P2U purinoceptors stimulate endothelial NOS in a manner that is dependent on PKC activity.

Animals↗

Phosphorylation and activation of p42 and p44 mitogen-activated protein kinase are required for the P2 purinoceptor stimulation of endothelial prostacyclin production.

Extracellular ATP and ADP, released from platelets and other sites stimulate the endothelial production of prostacyclin (PGI2) by acting on G-protein-coupled P2Y2 and P2Y2 purinoceptors, contributing to the maintenance of a non-thrombogenic surface. The mechanism, widely described as being dependent on elevated cytosolic [Ca2+], also requires protein tyrosine phosphorylation. Here we show that activation of both these P2 receptor types leads to the tyrosine phosphorylation and activation of both the p42 and p44 forms of mitogen-activated protein kinase (MAPK). 2-Methylthio-ATP and UTP, selectively activating P2Y1 and P2Y2 purinoceptors respectively, and ATP, a non-selective agonist at these two receptors, stimulate the tyrosine phosphorylation of both p42mapk and p44mapk, as revealed by Western blots with an antiserum specific for the tyrosine-phosphorylated forms of the enzymes. By using separation on Resource Q columns, peptide kinase activity associated with the phosphorylated MAPK enzymes distributes into two peaks, one mainly p42mapk and one mainly p44mapk, both of which are stimulated by ATP with respect to kinase activity and phospho-MAPK immunoreactivity. Stimulation of P2Y1 or P2Y2 purinoceptors leads to a severalfold increase in PGI2 efflux; this was blocked in a dose-dependent manner by the selective MAPK kinase inhibitor PD98059. This drug also blocked the agonist-stimulated increase in phospho-MAPK immunoreactivity for both p42mapk and p44mapk but left the phospholipase C response to P2 agonists essentially unchanged. Olomoucine has been reported to inhibit p44mapk activity. Here we show that in the same concentration range olomoucine inhibits activity in both peaks from the Resource Q column and also the agonist stimulation of 6-keto-PGF1, but has no effect on agonist-stimulated phospho-MAPK immunoreactivity. These results provide direct evidence for the involvement of p42 and p44 MAPK in the PGI2 response of intact endothelial cells: we have shown that both the endothelial P2Y purinoceptors are linked to activation of MAPK, and that activation of this pathway is a requirement for the stimulation by ATP/ADP of endothelial PGI2 production.

Adenosine Triphosphate↗

Factors affecting DNA-binding proteins and pcbC transcript levels in Penicillium chrysogenum.

Proteins extracted from Penicillium chrysogenum grown in either complex or defined medium were used in electromobility shift assays. With a probe DNA covering the region -10 to -132 relative to the pcbC translation start codon, four protein/DNA complexes (designated A-D) were reproducibly observed. Two of the four DNA/protein complexes routinely detected in extracts from liquid cultures (A and B) were also detectable with protein extracts from P. chrysogenum spores. Generally, with proteins from liquid cultures, there was a correlation between increased levels of the complexes and increased levels of the pcbC transcript. In addition, the detectable levels of the complexes and the pcbC transcript showed some relationship to the extracellular pH of the medium. In defined medium, with glucose as the carbon source, the pcbC transcript was not detectable in extracts from the wild-type strain at any time, whereas with the high penicillin-producing strain P-2, a pcbC transcript was detected. In complex medium, the pcbC transcript was detectable during the exponential phase of cultures of the wild-type or P-2, even when glucose levels were as high as 2.5% (w/v).

Blotting, Northern↗

Effect of the mouse scid mutation on meiotic recombination.

The goal of this study was to determine the effect of the mouse severe combined immunodeficiency (scid) mutation on the rate of meiotic recombination, by standard backcross linkage analysis. For this purpose, we examined four crosses that involved F1 hybrid animals heterozygous for the strain C57BL/6 and BALB/c genomes. In one set of reciprocal crosses, F1 animals were homozygous scid/scid, and in a second set of reciprocal crosses, F1 mice were homozygous wild-type (+/+) at the scid locus. Backcross progeny were typed for recombination between selected genetic markers on mouse Chromosomes (Chrs) 1, 4, 6, 7, 9, 15, and 17. Although some differences in recombination were observed over some intervals, the expression of the SCID phenotype did not appear to have a major or consistent effect on meiotic recombination.

Animals↗

Multicenter randomized clinical trial of home uterine activity monitoring: pregnancy outcomes for all women randomized.

OBJECTIVE: Our purpose was to evaluate the impact of home uterine activity monitoring on pregnancy outcomes among women at high risk for preterm labor and delivery. STUDY DESIGN: Women at high risk for preterm labor at three centers were randomly assigned to receive high-risk prenatal care alone (not monitored) or to receive the same care with twice-daily home uterine activity monitoring without increased nursing support (monitored). There were 339 women with singleton gestations randomized with caregivers blinded to group assignment. The two groups were medically and demographically similar at entry into the study. RESULTS: Women in the monitored group had prolonged pregnancy survival (p = 0.02) and were less likely to experience a preterm delivery (relative risk 0.59; p = 0.04). Infants born to monitored women with singleton gestations were less likely to be of low birth weight (< 2500 gm; relative risk 0.47, p = 0.003), and were less likely to be admitted to a neonatal intensive care unit (relative risk 0.5, p = 0.01). CONCLUSION: These data show, among women with singleton gestations at high risk for preterm delivery, that the use of home uterine activity monitoring alone, without additional intensive nursing care, results in improved pregnancy outcomes, including prolonged gestation, decreased risk for preterm delivery, larger-birth-weight infants, and a decreased need for neonatal intensive care.

Adult↗

Fatal thrombocytopenia associated with Mycoplasma pneumoniae infection.

The case of a 21-year-old male who presented with pneumonia associated with thrombocytopenia and bleeding and who died from intracranial haemorrhage is described. Very high titres of complement fixing and agglutinating anti-mycoplasma antibodies indicated recent Mycoplasma pneumoniae infection. Possible links between thrombocytopenia and M. pneumoniae infection are discussed.

Adult↗