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Biomedical subjects

L Joubert

Publications and source records attributed to L Joubert.

At least 19 recordsLinked to original sources
PubMed2005

Response of the microbial community to copper oxychloride in acidic sandy loam soil.

AIMS: Determining the response of different microbial parameters to copper oxychloride in acidic sandy loam soil samples using cultivation-dependent and direct microscopic techniques. METHODS AND RESULTS: Culturable microbial populations were monitored for 245 days in a series of soil microcosms spiked with different copper oxychloride concentrations. Microbial populations responded differently to additional Cu. Protistan numbers and soil metabolic potential decreased. Experiments with more soil samples revealed that metabolic potential was not significantly affected by < or =100 mg kg(-1) additional Cu. However, a negative impact on protista was noted in soil containing only 15 mg kg(-1) EDTA-extractable Cu. The negative impact on protistan numbers was less severe in soils with a higher phosphorous and zinc content. CONCLUSIONS: Bacterial populations responded differently, and protista were most sensitive to elevated Cu levels. Protistan numbers in soil from uncultivated land were higher and seemed to be more sensitive to additional Cu than the numbers of these organisms in soil originating from cultivated land. SIGNIFICANCE AND IMPACT OF THE STUDY: Protistan sensitivity to small increases in Cu levels demonstrates the vulnerability of the soil ecosystem to Cu perturbations, especially when the importance of protista as link in the flow of energy between trophic levels is considered.

Animals↗
PubMed2004

GPCR-interacting proteins (GIPs): nature and functions.

The simplistic idea that seven transmembrane receptors are single monomeric proteins that interact with heterotrimeric G-proteins after agonist binding is definitively out of date. Indeed, GPCRs (G-protein-coupled receptors) are part of multiprotein networks organized around scaffolding proteins. These GIPs (GPCR-interacting proteins) are either transmembrane or cytosolic proteins. Proteomic approaches can be used to get global pictures of these 'receptosomes'. This approach allowed us to identify direct but also indirect binding partners of serotonin receptors. GIPs are involved in a wide range of functions including control of the targeting, trafficking and signalling of GPCRs. One of them, Shank, which is a secondary and tertiary partner of metabotropic and ionotropic glutamate receptors, respectively, can induce the formation of a whole functional glutamate 'receptosome' and the structure to which it is associated, the dendritic spine.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Psychosocial aspects of sexual disorders.

BACKGROUND: The sexual urge is as old as humanity itself and necessary for the propagation of all species. However, sexuality is not only influenced by the integrity of the genital tract, but also the limbic system and spinal arousal centres. Social and cultural influences on sexual behaviour are in a continuous process of change. OBJECTIVE: This article attempts to highlight the importance of a multifaceted systemic approach to a common and distressing problem. DISCUSSION: The aetiology of sexual dysfunction is diverse and usually results from a complex interaction of biological, psychological and social factors. Consequently, there is little to be gained from trying to determine whether a disorder is either biological or psychological, as both will be relevant to a certain extent in every case. Even in a case with a clear biological cause (e.g. diabetic neuropathy) the treatment and long term consequences of the secondary sexual disorder will be affected by psychosocial implications. Sexual functioning can be strongly influenced by one's own sense of self and social competence.

Adult↗
PubMed1997

Excess of autorefraction over subjective refraction: dependence on age.

The purpose of this study was to examine the difference between subjective refraction and autorefraction for different age groups. We call the difference (autorefraction minus subjective refraction) the excess of autorefraction over subjective refraction or the autorefractive excess. Five age groups of 50 subjects each were used. Subjects in group 1 were aged between 1 and 10 years, group 2 between 11 and 20 years, group 3 between 21 and 30 years, group 4 between 31 and 40 years, and group 5 consisted of subjects over 41 years of age. Automatic refraction was performed with an Allergan Humphrey model 580 autorefractor. The data were analyzed using recently developed statistical methods for the analyzing of dioptric power. These methods include the use of the coordinate vector h as a representation of dioptric power. The results indicate that there is a statistically significant mean autorefractive excess and that the mean is different for different age groups. The behavior of the left and right eyes appears to be essentially the same. In terms of vector h the mean autorefractive excess for both the left and the right eyes of group 1 (1 to 10 years of age) is approximately (-0.25 0.00-0.43)'. It increases by roughly delta h = (0.10 0.00 0.10)' per decade. In more conventional terms the nearest equivalent sphere of the mean excess for group 1 is approximately -0.34 D for the right and for the left eyes. The mean autorefractive excess for group 1 is approximately -0.25 -0.18 x 180. The astigmatic component appears to be the same for all age groups, whereas the spherical component increases by approximately 0.1 D per decade. The standard deviations of the autorefractive excesses are relatively large for components h1, and h3 of h: they were between approximately 0.4 and 0.7 D, possibly decreasing slightly with age. The standard deviation of h2 remains at 0.2 D or less for all age groups. The greatest variation of autorefractive excess appears to be approximately in the spherical direction in symmetric dioptric power space and appears to be less for the older age groups than the younger age groups.

Adolescent↗
PubMed1997

The pattern-of-care model: a tool for planning community mental health services.

In periods of change, psychiatric services must project outcomes of decisions about service innovations and reductions, including budgetary implications. To support such decision making, a public-sector psychiatric service in Melbourne, Victoria, Australia, developed a modeling tool that combines data from its service activity database and budgetary information with modeling techniques based on use of a spreadsheet. The model is based on clients' use of three major service components: the inpatient unit, continuing clinical care and consultancy services, and crisis assessment and treatment services. It classifies clients according to patterns of care-that is, whether they used one, two, or three of the components, in various combinations. The authors report service use and financial data derived from the model for the financial year 1992-1993. They describe two scenarios for using the model to project changes in patterns of care and costs when new services are implemented. Such a model can clarify costs, including opportunity costs, of management decisions and facilitate participation of senior clinicians in active service planning within the realities of budgetary constraints.

Budgets↗
PubMed1990

Phase I study of oral spirogermanium.

Thirty-three patients with advanced malignancy were treated with oral spirogermanium in a Phase I study to determine a maximum tolerated dose. Patients were entered in the study at doses of 100, 200, and 300 milligrams daily. The dose-limiting toxicity was gastrointestinal with moderate nausea and vomiting occurring with the 300 milligram dose. No myelosuppression or renal dysfunction was noted. Elevations of serum transaminase were seen in 41 percent of the patients at study entry. While abnormalities in hepatic function were recorded during the study, the relationship to spirogermanium could not be determined. No patient exhibited clinical hepatic dysfunction or elevation of serum bilirubin. It is recommended that future studies of oral spirogermanium incorporate careful monitoring of these parameters. Two patients with lymphoproliferative disorders had objective responses to therapy. A dose of 200 milligrams is recommended for further Phase II trials.

Administration, Oral↗
PubMed1988

[The phenomenon of "early and stimulated death" in mice infected and then vaccinated against rabies].

Live (diluted) and inactivated rabies vaccines of low antigen content induce early and enhanced death in mice, inoculated before vaccination with a wild type of rabies virus. Such vaccines, which neither induce interferon nor protect, produce a low level of antibodies which appear later than with vaccines of higher antigenicity. It is recommended to examine rabies vaccines not only by the usual (pre-exposure) potency test-NIH test or modified NIH test (one vaccination), but also by a post-exposure potency test.

Animals↗
PubMed1985

Woodchuck hepatitis virus infection: serologic and histopathologic course and outcome.

Five out of seven American woodchucks inoculated with woodchuck hepatitis virus developed antigenemia after 2 to 13 weeks followed by an antibody response. One animal became a carrier, and another animal exhibited a primary antibody response. Clinical disease was not obvious and aminotransferase elevation could not be demonstrated. Liver biopsy showed mononuclear portal infiltration and little parenchymal cell necrosis.

Animals↗
PubMed1985

Dynamics of beta-adrenoceptor blockade with cetamolol.

Cetamolol is a new beta-adrenoceptor blocking agent shown in animals to have moderate beta 1-adrenoceptor selectivity and partial agonist activity. In healthy normal volunteers, beta 1-adrenoceptor blockade was measured as the reduction of exercise-induced tachycardia, systolic blood pressure, and double product at 2, 8, and 24 h after a single oral dose of 10, 25, and 50 mg cetamolol. beta 1-adrenoceptor blockade was significantly linearly related to log serum cetamolol level, was maximal at 2 h, and was still clinically significant at 24 h. A crossover study of single 0, 10, and 25 mg doses confirmed these findings.

Acetamides↗
PubMed1985

Involuntary smoking and lung cancer: a case-control study.

In a case-control study in 4 hospitals from 1971 to 1981, 134 cases of lung cancer and 402 cases of colon-rectum cancer (the controls) were identified in nonsmoking women. All cases and controls were confirmed by histologic review of slides, and nonsmoking status and exposures were verified by interview. Odds ratios (OR) increased with increasing number of cigarettes smoked by the husband, particularly for cigarettes smoked at home. The OR for women whose husbands smoked 20 or more cigarettes at home was 2.11 (95% confidence limits: 1.13, 3.95). A logistic regression analysis showed a significant positive trend of increasing risk with increased exposure to the husband's smoking at home, controlled for age, hospital, socioeconomic class, and year of diagnosis. Comparison of women classified by number of hours exposed a day to smoke in the last 5 years and in the last 25 years showed no increase in risk of lung cancer.

Adult↗
PubMed1984

Histologic type of lung cancer and asbestos exposure.

The histologic types of lung cancer in 855 patients (747 men and 107 women) from three hospitals and one international study of insulation workers were evaluated. Of these, 196 cases had asbestos exposure. About one half of the cases were diagnosed from surgical slides and one half from autopsy slides. Squamous cell carcinoma constituted the largest percentage of tumor types and was found with the same frequency in exposed and nonexposed groups. Small cell carcinoma was found in 25% of the exposed and in 15% of the nonexposed patients. Upper lung sites were involved in about two thirds of the cases with asbestos exposure and lower lobes in the other one third. There was little difference in histologic type in cases regardless of whether upper or lower lobes were involved. Cigarette smokers who smoked until their cancer diagnosis showed no difference in histologic type by amount smoked, and slight but not statistically significant differences from ex-cigarette smokers.

Adenocarcinoma↗
PubMed1984

[Spontaneous and experimental infection of alpine marmots (Marmota marmota) by the North American woodchuck hepatitis virus (Marmota monax). Initial results].

Summer's discovery in 1978 of a DNA virus, very close to human Hepatitis B virus in a woodchuck population in the U.S.A. (Pennsylvania) was a confirmation of the first description made by Snyder at Penrose Research Laboratory (Philadelphia). It was the first animal model of human B hepatitis infection. The comparative study of morphological, ecological and ethological characteristics of the marmot (Marmota marmota) and the woodchuck (Marmota monax) enables an easy distinction between these two species. The natural infection of M. monax by the WHV shows that the woodchuck is a good model for human B hepatitis and should be extended to M. marmota. A sample of 24 marmots caught in the Alpes of Haute-Provence has not revealed any spontaneous infection in these animals by the woodchuck virus. The failure of experimental inoculation of the marmot (24 animals) with the WHV confirms the refractory status of this species (no viremia and very low and short serological response with or without an immunosuppressive treatment). These preliminary results require a confirmation in other animals of different age and geographical region and also by using more specific tests such as molecular hybridization, research on DNA polymerase and direct transfection trials.

Age Factors↗
PubMed1982

Etodolac in postsurgical pain: a double-blind dose-ranging efficacy study with aspirin and placebo.

A study was conducted to compare the analgesic activity of single oral doses of etodolac (25, 50, 100, 200, and 400 mg) with 650 mg aspirin and placebo. A total of 146 patients with moderate or severe pain from orthopedic or urologic interventions received one of the test medications 13-25 h after the beginning of surgery and according to a randomized allocation balanced as to initial pain intensity. Data for pain intensity and pain relief were collected at 1/2 h and then hourly for 8 h. Vital signs and adverse reactions were also recorded. One hundred and forty-two patients completed the study: four were excluded because of protocol deviations. The average response to 100, 200, and 400 mg of etodolac was superior to that of placebo. On the basis of SPID, TOTPAR, and duration of analgesia, 400 mg etodolac was also significantly more effective than 650 mg aspirin. Mild side effects probably or possibly related to etodolac were reported by three patients. This study provides evidence that etodolac in doses of 100 mg and higher is an effective and well-tolerated analgesic.

Acetates↗