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Biomedical subjects

C Martin

Publications and source records attributed to C Martin.

At least 1,351 records · Page 75Linked to original sources
PubMedDate not supplied

Regulation of melatonin production by catecholamines and adenosine in a photoreceptive pineal organ. An in vitro study in the pike and the trout.

The pineal organ of fish contains photoreceptor cells with structural and functional analogies to retinal photoreceptors. In these cells, the light/dark (LD) cycle influences the production of melatonin by controlling the activity of one of its synthetizing enzymes, serotonin N-acetyltransferase (NAT). The daily rhythm in NAT activity is generated endogenously in the pike but not in the trout pineal. We report here that in addition to the LD information, chemical factors are also involved in the control of melatonin production. Adenosine and two of its analogs stimulated or inhibited NAT activity and melatonin release in cultured pike and trout pineals, depending on the experimental conditions. It is believed that the nucleoside, produced locally, exerts a modulatory role on the neurohormonal output via still enigmatic mechanisms, involving a transmembranous carrier. Nocturnal melatonin production in cultured pike pineals was inhibited by alpha-adrenergic agonists and stimulated by a beta-adrenergic agonist. No effect could be induced in trout pineals cultured under similar conditions. Because melatonin production by pineal photoreceptors is apparently regulated by both light and chemical inputs, we propose they might be multieffector cells.

Adenosine↗
PubMedDate not supplied

Ondansetron compared with granisetron in the prophylaxis of cisplatin-induced acute emesis: a multicentre double-blind, randomised, parallel-group study. The Ondansetron and Granisetron Emesis Study Group.

This is the first international, multi-centre, double-blind, randomised, parallel group study to directly compare the efficacy and safety profile of a single intravenous dose of ondansetron (8 or 32 mg) with granisetron (3 mg) in the control of cisplatin-induced acute emesis. A total of 496 patients were randomised to receive one of three anti-emetic treatments prior to cisplatin chemotherapy (> or = 50 mg/m2). Of these, 165 and 162 patients received 8 and 32 mg of ondansetron, respectively, and 169 patients received 3 mg of granisetron. Complete control of emesis (0 emetic episodes) over 24 h was reported in 59% of patients in the 8-mg ondansetron group, 51% of patients in the 32-mg ondansetron group and 56% of patients in the granisetron group. Complete or major control (< or = 2 emetic episodes) was achieved in 76 and 74% of patients in the 8- and 32-mg ondansetron group, respectively, compared with 78% of patients in the granisetron group. Nausea graded none or mild 24 h after the start of cisplatin infusion was reported in 71 and 69% of patients in the 8- and 32-mg ondansetron groups, respectively, and in 73% of patients in the granisetron group. There were no significant differences between the treatment groups when global satisfaction scores were compared. Logistic regression models were fitted to assess any interaction between treatments and prognostic factors (age, gender, alcohol use, cisplatin dose or concomitant chemotherapy) on complete or major response, but there was no evidence of interaction for any factor. All three anti-emetic treatments were well tolerated and no severe or unexpected drug-related adverse events were observed with ondansetron or granisetron. Headache, the most reported drug-related adverse event for all three treatment groups, occurred in 9% of all patients. In summary, no significant difference was observed between any of the treatment groups with respect to emesis, nausea or drug-related adverse events.

Adult↗
PubMedDate not supplied

Nurses' role in family health services authorities.

Changes in the philosophy and provision of community care which were created by implementation of the National Health Service and Community Care Act 1992 have had far-reaching effects. This article addresses the implications of these changes for nursing in general practice and the role of the family health services authority in the community.

Community Health Services↗
PubMedDate not supplied

7-Desmethyl-microcystin-RR, a hepatotoxin from a waterbloom of Microcystis aeruginosa.

A peptide toxin was isolated from a waterbloom of Microcystis aeruginosa from Lake Frøylandsvatn in Norway. The isolation procedure included liquid and solid phase extraction and reversed phase high performance liquid chromatography. Amino acid analysis yielded D-glutamic acid, D-erythro-beta-methylaspartic acid and D-alanine in equimolar and L-arginine in twofold molar ratios. The presence of dehydroalanine was confirmed by hydrogenation and subsequent amino acid analysis with combined gas liquid chromatography/mass spectrometry. Investigation of the toxin with fast atom bombardment mass spectrometry showed a nominal relative molecular mass of 1023. 3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyl- 4,6-decadienoic acid (Adda) was identified by 1H NMR and 1H, 1H COSY spectroscopy. The structure of the toxin was elucidated as 7-desmethyl-microcystin-RR.

Amino Acid Sequence↗
PubMedDate not supplied

Ultrastructure of 26 cases of Ki-1 lymphomas: morphoimmunologic correlation.

Twenty-six cases of high-grade lymphomas with activation markers (CD30) classified and immunophenotyped according to the Kiel classification were studied to determine their fine structural features. Transmission electron microscopy showed in 17 cases anaplastic nuclear and cytoplasmic changes identical to those observed in Hodgkin's disease, it being impossible to determine by the morphology a B, T, or null nature. Four high-grade B-centroblastic and immunoblastic cases and five T-pleomorphic cases showed nuclear changes and cytoplasmic differentiation that suggested a T or B nature. An immunogold-labeling technique showed CD30-positive particles primarily in the Golgi complex and occasionally in the cell membrane.

Antigens, Differentiation↗
PubMedDate not supplied

Origin of erythropoietic stem cells in avian development: shift from the yolk sac to an intraembryonic site.

Haemopoietic stem cells are currently considered as deriving exclusively from the embryonic yolk sac in birds and mammals. A new experimental approach has been devised: quail embryonic bodies are grafted on to chick yolk sacs before establishment of circulation, and allowed to develop. The proportions of quail and chick erythrocytes in the circulating blood are assayed through a differential immunohaemolysis technique. Up to 10 days of incubation, grafted quails have 80 to 95% chick erythrocytes. Between 10 and 13 days, quail erythrocytes appear in increasing proportions making up as much as 80% of the red blood cells in some embryos. Morphological analysis reveals that chick cells colonize transiently the spleen of grafted embryos between 10 and 12 days, and undergo erythropoiesis in that organ. However at 13 days chick cells have disappeared from the spleen of grafted embryos. It is concluded that yolk sac stem cells are capable of colonizing intraembryonic organs, but do not do permanently and that there is an intraembryonic source of definitive erythropoietic stem cells.

Age Factors↗
PubMedDate not supplied

[Public health professionals' perceptions regarding two dimensions of health promotion: the ecological approach and community participation].

The aim of this paper is to explore public health professionals' perceptions regarding two dimensions of the new health promotion movement: the ecological approach and the principle of community participation. Data were collected by focus-groups of public health professionals (n = 22) in one Public Health Directorate in Québec. Results indicate a fair degree of integration of these two dimensions into the respondents' professional practice. However, limitations related to the work environment and to the theoretical underpinnings of these two components might impede the respondents' ability to integrate them into their practice.

Ecology↗
PubMedDate not supplied

Virulence gene regulation in pathogenic Escherichia coli.

The ability to regulate gene expression throughout the course of an infection is important for the survival of a pathogen in the host. Thus, virulence gene expression responds to environmental signals in many complex ways. Frequently, global regulatory factors associated with specific regulators co-ordinate expression of virulence genes. In this review, we present well-described regulatory mechanisms used to co-ordinate the expression of virulence factors by pathogenic Escherichia coli with a relative emphasis on diseases caused by E. coli in animals. Many of the virulence-associated genes of pathogenic E. coli respond to environmental conditions. The involvement of global regulators, including housekeeping regulons and virulence regulons, specific regulators and then sensor regulatory systems involved in virulence, is described. Specific regulation mechanisms are illustrated using the regulation of genes encoding for fimbriae, curli, haemolysin and capsules as examples.

Animals↗
PubMedDate not supplied

[Ocular bacterial infections : present and prospective methods of diagnosis].

Bacteriological samples and tests are essentiel for the diagnosis of superficial ocular infections and endophtalmitis. The direct examination and the traditional culture of the samples can be in the futur associated with new diagnostic approach using antigen detection (immunofluorescence, enzyme immunosorbent assays) and genome research by hybridation or better by amplification for Chlamydia and for the most frequent species responsible of endophtalmitis. An original genomic strategy of bacterial endophtalmitis diagnosis was developped.

Antigens, Bacterial↗
PubMedDate not supplied

[On what depends the dependence? Thoughts on the law establishing a specific subsidy of dependence in old age].

The dependency of elderly persons became recently an autonomous issue beside the problem of the pensions or the disability. We can explain this late apparition in the field of social policy by a strong attention paid to problems of the pensions and the lack of interest to the new concept of disability. But the main reason is the disagreement on two main questions. There is no common vision on the resources that the community must devote to help dependent people and their family. Moreover there is no agreement on the quality assurance of the services provided. The public debate for the first law was focused on the measure of the dependency and its budget. The second, in a context of growth of the number of dependent people, must integrate the need of support for an increasing number of families, and the condition for production of care of quality.

Activities of Daily Living↗
PubMedDate not supplied

[Evaluating the quality of life of 42 heart transplant patients and candidates: a cross-sectional study].

OBJECTIVE: Although evaluation of heart transplant candidates and recipients is usually based on objective clinical variables, self-assessment has been proved to be an important component of treatment evaluation. Quality of life is a multidimensional concept, a mix of objective and subjective measures, that could reflect the adjustment to the illness and its treatment. Few studies have reported on quality of life in heart transplantation candidates. This exploratory study, conducted in Bordeaux (France), was designed to assess both objectively and subjectively the quality of life in heart transplant candidates and recipients and to determine the relationships between subjective and objective variables. METHOD: The assessment was cross-sectional; 21 candidates evaluated at an average of 10 (Sd 21.4) months into the waiting period, were matched with 21 recipients at 29.5 months post operative. Subjective evaluation of the quality of life was self-assessed by the Tableau d'évaluation assistée de la qualité de la vie (TEAQV) and the Nottingham Health Profile (NHP). A semi structured psychiatric interview, and the NYHA (New York Heart Association) cardiac insufficiency score provided objective measurements. RESULTS: The NHP and TEAQV mean scores were not not significantly different between the two groups: candidates (C) and recipients (R) reported similar subjective data regarding positive quality of life experience. The objective data indicated significant disadvantages for the candidate group: the cardiac insufficiency score was worse in the candidates [(NYHA mean score: (C) = 2.7 Sd 0.56 vs (R) = 0.7 Sd 0.8, t de Student p < 0.01)] and the DSM III-R axis 1 diagnoses were more frequent in the candidates [(C) = 16/21 vs (R) = 9/21 Chi2 p < 0.05)]. There was a prevalence of adjustment disorders in the candidates. Significant correlations were found between NYHA and NHP mean scores (r = 0.6, p < 0.01) and NYHA and physical and psychological dimensions of the TEAQV (r = -0.65 and r = -0.55, p < 0.01) in the recipient group. In the candidate group, no correlation was found between these scores. CONCLUSION: In the recipient group, objective and subjective assessment showed greater concordance than in the candidate group. Despite more objective physical and moderate yet frequent psychiatric complications, the candidate group reported as positively as did the recipients upon the quality of their life experience. This could be the result of psychological adaptation to the stressful situation. These data were in accordance to several earlier reports. However, the literature has remained controversial upon the evaluation of the quality of life of the candidates. The results of this study, limited by some methodological bias (the small number of patients assessed), need to be confirmed in a prospective study.

Adaptation, Psychological↗
PubMedDate not supplied

[A survey of private practice psychiatrist's training and activity in activity in Aquitaine, France, in 1993].

UNLABELLED: This study was conducted to gather information regarding the current professional activities of French private practice psychiatrists. METHOD: A mail survey was carried out in an attempt to find more about the characteristics of the 380 private practice psychiatrists in Aquitaine (south west France) in 1993. Data are reported in terms of psychiatrist's characteristics (demographics, training and practice activities), patient characteristics and trends in treatment modalities. RESULTS: There was a good response rate (55%), and this enabled us to statistically analyze the data to determine profiles of activities. For the respondents in this survey, the median age is 45 years and 30.7% of respondents are women. The portion of responders reporting a qualification in Neuropsychiatry versus Psychiatry, is low (1/7). The patients seen in private practice are generally young females with anxiety and affective disorders. An important feature was the trend for psychotherapy training and practice. Psychoanalytically oriented and individual psychotherapy were predominant over other forms of psychotherapy. Half of the psychiatrists reported using pharmacotherapy in combination with psychotherapy. There are only little differences in the practice of young and female psychiatrists. CONCLUSION: The impact of psychodynamic theories on the training of French private practice psychiatrists is still very important. Interestingly, these same psychiatrists seem to use an eclectic approach to their practice of psychiatry; about half of the respondents report using pharmacological treatments in combination with psychoanalytically oriented psychotherapy.

Adult↗
PubMedDate not supplied

[Quantitative evaluation of sharing practices of materials at risk for infectious virus contamination by intravenous opiate users seeking treatment--application of the RAB(Risk for AIDS Behavior) self-administered questionnaire].

The objective of this study was to quantify the occurrence of AIDS risk related sharing activities in i.v. opiate users seeking treatment using a self administered questionnaire. Subjects were recruited among first time consultants of an outpatient clinic and assessed using the Risk for AIDS Behavior questionnaire (RAB), a self administered questionnaire that assesses both needle-sharing and unprotected sexual activity; the Beck Depression Inventory (BDI) a self administered questionnaire that assesses depressive symptoms; and the Addiction Severity Index (ASI), a 45-min, structured interview that provides assessments of problem severity in seven functional areas commonly impaired among drug abusers. Among the 102 patients who came in for treatment, all 66 subjects reporting i.v. drug abuse agreed to participate. The study was based on the data collected from these 66 subjects of whom 49 were males (74%) and mean age +/- SD was 31 +/- 5. Fifty-eight-percent of theses subjects reported having shared needles or related paraphernalia over the past 6 months. Despite informational campaigns on the risks of sharing and despite the well spread knowledge of such a risk, most i.v. opiate users seeking treatment report having shared at least once over the previous 6 months.

Acquired Immunodeficiency Syndrome↗