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Biomedical subjects

J Raus

Publications and source records attributed to J Raus.

At least 109 records · Page 6Linked to original sources
PubMed1990

An augmented escape of beta-endorphins to suppression by dexamethasone in severely depressed patients.

Baseline beta-endorphin and cortisol levels and their responses to 1 mg dexamethasone were measured in 11 healthy controls and in 35 depressed patients, categorized according to the DSM-III. Dexamethasone significantly suppressed beta-endorphin levels. Depressed patients with melancholia/psychotic features exhibited significantly increased post-dexamethasone beta-endorphin levels compared with healthy controls, minor and simple major depressives; the baseline beta-endorphin levels did not differ between those study samples. Post-dexamethasone beta-endorphin and cortisol values were found to be significantly and positively correlated. Accordingly, cortisol non-suppressors showed significantly higher post-dexamethasone beta-endorphin levels. Post-dexamethasone beta-endorphin may be the most sensitive and specific reflection of the disorder in negative feedback exerted by dexamethasone in depression.

Adult↗
PubMed1990

The identification of polyoxyethylene glycols and related compounds by capillary gas chromatography.

A sample work-up method for gas chromatographic profiling of polyoxyethylene glycol (PEG)-related compounds in pharmaceutical matrices is described. After a short sample clean-up, carbon-oxygen linkages are partially cleaved with 0.07 M boron tribromide in dichloromethane at room temperature. The reaction is stopped after 1 min by addition of 0.01 M HCl. The products are trimethylsilylated and injected onto a WCOT 50 m x 0.25 mm CP-SIL 5 CB fused silica column. Eleven model compounds, representing four common types of PEG-derivatives, have been evaluated by this method. The results show that characteristic profiles can be obtained from PEG-derivatives carrying different functional groups. Minimum detectable amounts are in the range of 200 micrograms.

Chromatography, Gas↗
PubMed1990

Suppressant effects of dexamethasone on the availability of plasma L-tryptophan and tyrosine in healthy controls and in depressed patients.

Formation in the brain of serotonin from L-tryptophan (L-TRP) and noradrenaline from tyrosine are pathways related to the pathophysiology of major depression and to the regulation of the hypothalamic-pituitary-adrenal (HPA) axis. In the past, decrements in L-TRP availability and disorders in the HPA axis have repeatedly been observed in major depressed patients; both factors were shown to be inversely correlated. In order to investigate the relationships between glucocorticosteroid activity and the availability of L-TRP and tyrosine, the authors measured L-TRP, tyrosine, valine, leucine, isoleucine and phenylalanine in baseline conditions and after treatment with 1 mg dexamethasone in 16 healthy controls and in 50 depressed patients. The ratios between L-TRP and tyrosine and the sums of the amino acids known to compete with them during transport across the blood-brain barrier were computed as an index of (respectively) the serotonin and noradrenaline synthesis in the brain. We found significantly decreased plasma L-TRP and tyrosine levels after treatment with dexamethasone compared with basal levels. Accordingly, the plasma ratios between L-TRP and tyrosine and the sum of the competing amino acids were significantly reduced by dexamethasone administration. It was hypothesized that through these actions of dexamethasone on peripheral amino acids, the central noradrenaline and serotonin control over the HPA-axis could be altered.

Adult↗
PubMed1990

Comparison of the staphylocoagulase activities of Staphylococcus aureus and Staphylococcus intermedius on Chromozym-TH.

The staphylocoagulases of Staphylococcus intermedius (39 strains from clinical samples from dogs and 1 strain from a pigeon) and Staphylococcus aureus (40 strains from nine different animal species) were compared by using the chromogenic methods of Engels et al. (W. Engels, M. Kemps, and C. P. A. van Boven, J. Clin. Microbiol. 14:496-500, 1981). S. intermedius produced staphylocoagulase which resembled that of S. aureus in its rate and method of action on prothrombin, but S. intermedius produced it in lesser amounts. Therefore, chromogenic substrate tests such as Chromozym-TH (Boehringer GmbH, Mannheim, Federal Republic of Germany) (as described by Engels et al.) can be used for the detection of staphylocoagulase in both of these species. However, to detect accurately the presence of S. intermedius staphylocoagulase by this method, preconcentration of the extracellular proteins or an extension of the reaction time of the test would be required. The method described by Engels et al. was designed specifically for clinical laboratories that handle human samples. Under those circumstances the method could be regarded as specific, enabling an identification of S. aureus only. However, as both S. aureus and S. intermedius give positive results in this test, in veterinary diagnostic laboratories, heavy reliance must not be placed on this test for determination of organisms to the species level.

Animals↗
PubMed1990

Hypersomatotropism in the dysmature infant at term and preterm birth.

Growth hormone (GH) concentrations were measured in cord serum of small (less than 2.4 kg), appropriate (3.4 +/- 0.1 kg) and large (greater than 4.4 kg) infants born at term (38-42 weeks), and in cord serum of prematurely born twins (28-36 weeks) which were either appropriate (greater than P10) or small (less than P10) for gestational age. Cord serum GH levels were found to be significantly elevated in small for gestational age infants, both at term and preterm birth. In view of the insulin-antagonizing action of fetal GH, these results further support a homeostatic function for GH in the late-gestational human fetus.

Fetal Blood↗
PubMed1990

Alpha-1-proteinase inhibitor gene frequencies in Belgium.

The alpha-1-antitrypsin phenotype was determined in cord blood of 1345 Belgian newborns by isoelectric focusing in polyacrylamide gels. Proteinase inhibitor (PI) gene frequencies were calculated. The relative gene frequency of the M allele was 0.9245, and those of S and Z alleles were 0.0543 and 0.0167 respectively. I and F alleles were less represented. These results are in agreement with population studies of neighbouring countries.

Belgium↗
PubMed1989

Human B cell lines secreting IgM antibody specific for myelin basic protein.

In this study we describe for the first time the production of stable human B cell lines and clones that secrete IgM antibody specific for human myelin basic protein. The technique based on limiting dilutions of Epstein-Barr virus (EBV)-transformed peripheral B cells from patients with multiple sclerosis precluded the need for preselecting or stimulating antigen-specific B cells. Most of the cell lines were stable for at least 6 months in continuous culture and produced 5-12 micrograms/ml antibody after 2 weeks in culture. The myelin basic protein (MBP)-specific B cells were surface IgM positive, and occurred with a frequency of approximately 1/2500 mononuclear cells in peripheral blood. The successful selection and quantitation of specific B cell clones described here suggests that this technique is well suited for evaluating B cell responses to known and suspected antigens and autoantigens.

Antibodies, Anti-Idiotypic↗
PubMed1989

Identification of polysaccharides in pharmaceuticals by capillary gas chromatography.

A sensitive method for the identification of polysaccharides in pharmaceuticals is described. Polysaccharides are isolated by gel filtration and subsequently hydrolysed. The monomeric carbohydrates obtained are transformed into oxime-trimethylsilyl derivatives and analysed by capillary gas chromatography. Profiles of 13 different natural or semi-synthetic polysaccharides are discussed. The profiles of the hydrolysis products can be used to identify the polysaccharides mentioned above. Possible interferences by other polymers are given. The method can be used to identify most polysaccharides used as pharmaceutical adjuvants.

Alcohols↗
PubMed1989

The nephrotoxic potential of neomycin in the horse.

Neomycin was administered intramuscularly to four normal adult horses at a dose rate of 10 mg/kg bodyweight every 12 h for 10 days (21 doses). The pharmacokinetic behaviour of neomycin with multiple dosing was characterised and a range of blood chemical and urinary parameters examined for evidence of nephrotoxicity. There was evidence of physical renal tubular injury (enzymuria and cylindriuria) within four days of neomycin administration but this subsided following cessation of treatment. No significant functional nephrotoxicity was detected. More severe nephrotoxicity might be expected in ill horses and it is recommended that several clinicopathological results be monitored serially in those horses receiving parenteral neomycin.

Alkaline Phosphatase↗
PubMed1989

Cortisol, ACTH, prolactin and beta-endorphin responses to fenfluramine administration in major-depressed patients.

In the past, some researchers found increased cortisol and prolactin responses to the administration of fenfluramine in major-depressed patients. It was believed that the fenfluramine test could prove to constitute another challenge probe to reflect the central serotonergic function. The present study was conducted in order to investigate the pituitary/adrenal responses to fenfluramine in major- versus minor-depressed patients. To this end we administered 60 mg D,L-fenfluramine p.o. to 40 depressed patients categorized according to the DSM-III. The basal levels of cortisol, adrenocorticotrophic hormone (ACTH), beta-endorphins and prolactin and their levels 2 and 4 h after fenfluramine administration were measured. We found no significant effect for fenfluramine treatment on cortisol, ACTH or beta-endorphins. There was a significant (p = 0.02) effect for fenfluramine treatment on prolactin. The enhanced secretion of prolactin was only significant (p = 0.006) in major (296.X2, 296.X3, 296.X4) and not in minor (300.40, 309.00) depressives. It was concluded that our findings corroborate the thesis of a hypersensitive serotonergic neurotransmission during a major depressive episode.

Adrenocorticotropic Hormone↗
PubMed1989

Impaired lymphocyte stimulation by mitogens in severely depressed patients. A complex interface with HPA-axis hyperfunction, noradrenergic activity and the ageing process.

To investigate the relationships between the immune apparatus, major depression, and HPA-axis and noradrenergic activity, the authors measured the lymphocyte stimulation responses to the mitogens phytohaemagglutinin (PHA), pokeweed mitogen (PWM) and concanavalin A (CON A), post-dexamethasone cortisol (DST) values and 3-methoxy-4-hydroxyphenylglycol (MHPG) excretion in 24-hour urine samples from 48 patients. We found that lymphocyte responses to PHA and PWM in melancholic and psychotic depressives were significantly lower than in minor depressives. The lymphocyte responses to PHA, PWM and CON A showed significantly negative correlations with age, DST results and HRSD score. Responses to PHA were significantly negatively correlated with MHPG excretion. Up to +/- 33% of the variance in the three mitogenic lymphocyte responses could be explained by canonical correlation with age, DST results and MHPG values.

Adult↗
PubMed1988

Neonatal screening for alpha-1-antitrypsin deficiency.

The results of a neonatal screening programme for alpha-1-antitrypsin deficiency are presented. Cord blood samples with an alpha-1-antitrypsin concentration below 1.628 mg/ml, as measured by an enzyme-linked immunosorbent assay method, were phenotyped by isoelectric focusing in polyacrylamide gels. Abnormal phenotypes were found in 51% of this group as compared with 11.3% in a control group (P much less than 0.0001). Twenty subjects detected by the initial quantitative alpha-1-antitrypsin determination had a highly pathogenic phenotype (PiZZ, PiSS, PiSZ). In the control group only moderately affected individuals were found (PiMS, PiMZ).

Belgium↗
PubMed1986

Gentamicin dosage in foals aged one month and three months.

The absorption and disposition kinetics of gentamicin were compared at two dosage levels (2 and 4 mg/kg bodyweight [bwt]) in one- and three-month-old foals. Following intramuscular (im) injection of single 2 mg/kg bwt doses, the drug was absorbed rapidly and produced peak serum concentration (18.2 mu 5.3 +/- g/ml, n = 8) at 30 mins. Much wider variations were associated with the amount of drug absorbed and the serum gentamicin concentrations after administration at the higher dosage level. The half-life of gentamicin was similar in the one-month-old (3.7 +/- 1.7 h, n = 8) and three-month-old (3.3 +/- 0.8 h, n = 8) foals, and was independent of the dose. One-month-old foals did not appear to have a deficiency in renal excretion of gentamicin. The minimum inhibitory concentration of gentamicin for Corynebacterium equi and certain other equine bacterial isolates was less than 0.195 microgram/ml. It was concluded that 2 mg/kg bwt administered by im injection at 8 to 12 h intervals, depending on the severity of the infection, could be recommended as the dose rate for treatment of systemic infections caused by microorganisms that are susceptible to gentamicin.

Absorption↗
PubMed1985

Leu-3+ lymphocytes account for increased CSF cellularity.

Inflammatory conditions of the central nervous system (CNS) are often marked by an increase in lymphocyte number in the cerebrospinal fluid (CSF). In order to determine if changes in CSF cell numbers can alter T-lymphocyte subset composition in CSF or in blood, cell surface markers were evaluated in 25 CSF and paired blood samples from a variety of neurologically affected patients. T-cell subset levels in peripheral blood did not reflect subset levels in paired CSF samples. However, CSF samples with elevated cell numbers (greater than 3 cells/mm3) had significantly increased levels of Leu-3+ T-cells (P less than 0.001), but not Leu-2+ T-cells relative to CSF samples with low cell counts. These data suggest a selective increase in the Leu-3+ T-lymphocyte subset in CSFs with increased cellularity in patients with acute neurologic signs.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1983

Characterization of coagulase-positive Staphylococcus intermedius and Staphylococcus aureus isolated from veterinary clinical specimens.

Staphylococci were the most frequent isolates from clinical specimens submitted from a large referral and teaching veterinary hospital. In this study a total of 160 isolates were examined by a wide range of biochemical tests and modifications of basic procedures. An attempt was made to test the validity of these procedures for use in characterization of clinical isolates of coagulase-positive staphylococci. Of the isolates examined, some 27 were Staphylococcus aureus, 115 were Staphylococcus intermedius, and the rest were coagulase-negative staphylococci and were not characterized further. The most useful discriminatory tests were acid production from maltose incubated overnight on maltose purple agar (W. E. Kloos and K. H. Schleifer, J. Clin. Microbiol., 1:82-88, 1975), acetoin production detected by the Barritt method, and detection of hyaluronidase activity. These gave accurate and fast results. Supplemented with the tellurite reduction test and the direct staphylocoagulase assay using Chromozym TH (Engels et al.; J. Clin. Microbiol. 14:496-500, 1981), these tests should eliminate the possibility of false identifications of these two species.

Animals↗