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Biomedical subjects

J Clement

Publications and source records attributed to J Clement.

At least 73 records · Page 4Linked to original sources
PubMed1991

Long-lasting effects of audiogenic seizures on neurotransmitter amino acids in Rb mice.

The existence of long-lasting (15-18 h) alterations of neurotransmitter amino acid levels following a single or repeated acoustic stimulations in audiogenic seizure-prone Rb1 and Rb2 mice and seizure-resistant Rb3 mice were investigated. The levels of glutamate, aspartate, glycine, taurine, and of some of their precursors: glutamine and serine were determined. Fourteen brain areas were examined. Alterations were found only in 6 brain areas (pons, olfactory bulbs, superior colliculus, inferior colliculus, olfactory tubercles and raphe). Most frequent occurring changes were observed in pons and olfactory tubercles. These changes concerned mainly the excitatory amino acids, glutamate, and aspartate. Alterations of taurine, glycine and serine were also recorded.

Acoustic Stimulation↗
PubMed1991

Expression of S14-mRNA and its translational product in differentiating 3T3-L1 cells.

During adipogenic conversion of 3T3-L1 cells S14-mRNA increased from undetectable levels in preadipocytes to high levels in differentiated adipocytes (adipocyte-like cells). In vitro translation of hybrid-selected S14-mRNA revealed an identical protein in 3T3-L1 adipocytes and in rat liver with regard to migration properties in two-dimensional gel electrophoresis. No translation product was found in 3T3-L1 preadipocytes. In conclusion, protein-S14 is very similar or even identical in rat lipogenic tissues and in 3T3-L1 adipocytes. Therefore, this cell line can be employed to elucidate further physiological aspects of protein-S14.

Adipose Tissue↗
PubMed1990

Amino acid neurotransmitter alterations in three sublines of Rb mice differing by their susceptibility to audiogenic seizures.

The levels of inhibitory amino acids (Tau, Gly), or excitatory amino acids (Glu, Asp) and Gln, precursor of GABA, have been determined, under resting conditions, in 17 brain areas of 3 sublines of inbred Rb mice displaying different responses to an acoustic stimulus. Rb1 mice were clonictonic seizure-prone, Rb2 mice were clonic seizure-prone and Rb3 mice were seizure resistant. Profile of distribution in the brain of each one of these amino acids differed. Maximum to minimum level ratio was higher for Tau (3.8) than for Glu or Asp or Gln (2). The level of Gly was similar in 13 out of the 17 areas examined. Multiple inter-subline differences were recorded for each amino acid. These differences have been analyzed considering the seizure susceptibility or severity of the three Rb sublines. Common lower levels (approximately -20%: Rb1/Rb3, Rb2/Rb3) of Gln in Temporal Cortex may be implicated in seizure susceptibility. Seizure severity (Rb1/Rb2) seems to correlate, in some areas, with additional lower amounts of GABA already reported and, to a lower extent, of Asp (-19% in striatum, inferior colliculus and cerebellum), of Tau and Gly; a tendency for a rise in Gln content was observed in certain others (10-20% in olfactory bulb, thalamus, hypothalamus, substantia nigra, and frontal, temporal and occipital cortex). The data and correlations recorded provide guidelines for further investigations for synaptosomal and metabolic alterations in the three sublines of the same strain of Rb mice.

Acoustic Stimulation↗
PubMed1989

Long lasting effect of a single audiogenic seizure on GABA turnover rates and steady-state levels.

GABA turnover rates (TOR) and steady-state levels (SSL) were determined, 16-18 h after a single acoustic stimulation, in 15 brain areas of 3 mouse sublines. Each subline differs in its response to an acoustic stimulation (Rb1 mice are clonic-tonic seizure-prone, Rb2: clonic seizure-prone, Rb3: seizure-resistant). TOR and SSL were compared to those of unstimulated control mice and to those of repeatedly stimulated mice of the same subline. Following a single acoustic stimulation long-lasting alterations of GABA metabolism, mainly large alterations of GABA TOR, are observed. Most of the effects elicited after repeated stimulations, either on SSL or TOR, are not those of the last stimulation and repeated seizures (and/or stimulations) strengthen the effect of a single one. It appears that, for each of the Rb sublines, a specific and quite simple profile of the alterations of GABA metabolism in response to a single or repeated audiogenic seizures (and/or stimulations) can be given. The global analysis through the correlation of GABA TOR and SSL gives an indication that the alterations of the parameters of the correlation observed are to be allocated to the audiogenic seizures. Furthermore the tonic and clonic components of the audiogenic seizures can be distinguished.

Acoustic Stimulation↗
PubMed1989

Total respiratory resistance and reactance as a measurement of response to bronchial challenge with histamine.

The potential of the forced oscillation technique to detect the airway response on histamine bronchial challenge tests was compared with that of FEV1 and plethysmographic SGaw. In 53 subjects with a history of episodic wheezing and a normal baseline airway resistance, we carried out bronchial challenges with successively doubling concentrations of histamine until FEV1 had dropped by 15% or more or a concentration of 16 mg/ml histamine was reached. For the baseline values, a mean within-subject coefficient of variation was found of 2.8% for FEV1, 7.4% for SGaw, 8.7% for the oscillatory respiratory conductance at 6 Hz (1/Rrs6), and 7.7% for the mean oscillatory respiratory conductance (between 2 and 26 Hz) (1/Rrs). The latter coefficients allow the calculation of the following threshold values: PD15FEV1, PD40SGaw, PD47 1/Rrs6, and PD42 1/Rrs. The probability of exceeding these levels by chance is virtually zero. Histamine challenge caused significant absolute changes in Rrs at 6 Hz (Rrs6), in mean level of Rrs and of respiratory reactance (Xrs), in slope of Rrs and Xrs versus frequency, and in mean curvature of Rrs-frequency curve. A multivariate analysis of the differences between prechallenge and postchallenge values showed that the parameters with the best sensitivity to detect the effect of histamine were, in decreasing order: the relative change of SGaw, of 1/Rrs6, of 1/Rrs, of FEV1, of FVC, and of 1/Vtg, followed by the absolute change of Xrs and of the average slope of the Rrs-frequency relationship.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

A sporadic case of acute Hantavirus nephropathy in The Netherlands.

A 32-yr-old man presented with acute renal failure preceded by a viral-like disease with high fever, bilateral loin pain, nausea, headache and slight thrombocytopenia. Renal biopsy revealed only minor tubulointerstitial abnormalities. Renal function completely normalised within 10 days after hospitalisation. The diagnosis of acute Hantavirus nephropathy was proved by serological examinations.

Acute Kidney Injury↗
PubMed1988

[Not Available].

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History, Modern 1601-↗
PubMed1987

Age-dependent changes of brain GABA levels, turnover rates and shock-induced aggressive behavior in inbred strains of mice.

Shock-induced aggressive behavior (SIAB) is absent or very weak in C57BL/6 (C57) mice at the age of 12 weeks while it reaches high levels at the age of 20 weeks. This age-dependent increase of aggressive responses is absent in DBA/2 (DBA) mice. Aggressive C57 mice (20 week old) are characterized by lower GABA levels in amygdala, striatum and substantia nigra than both non-aggressive C57 (12 week old) and DBA mice (12-20 week old). Concerning turnover rate, C57 mice at the age of 20 weeks show lower turnover rate values in cerebellum and raphe and higher values in septum in comparison with 12 week old mice of the same strain. These results are discussed in terms of the role of GABA function in brain areas which are involved in the control of emotionality and aggressive behavior.

Age Factors↗
PubMed1987

Effect of repeated convulsive seizures on brain gamma-aminobutyric acid metabolism in three sublines of mice differing by their response to acoustic stimulations.

The turnover rates and steady-state levels of gamma-aminobutyric acid (GABA) have been determined in 15 brain areas of three sublines of inbred mice differing in their susceptibility to audiogenic seizures: Rb3, which is seizure resistant; Rb2, which develops clonic seizures; and Rb1, which develops tonic-clonic seizures. In the Rb1 subline, GABA steady-state levels are lower than in the Rb3 subline in three of the 15 areas examined (cerebellum, anterior colliculus, and amygdala), whereas in the Rb2 subline, steady-state levels are either higher (posterior colliculus and hippocampus) or lower (amygdala) than in the Rb3 subline. GABA turnover rates differ in three brain areas in Rb1 (amygdala, raphe, and hypothalamus) and in a single area (amygdala) in Rb2 when compared with Rb3. Only one area has similar variations of GABA turnover rate and steady-state levels in the two susceptible sublines: the amygdala. After 2 weeks of repeated auditory stimulations (two times a day, 8,000 Hz, 100 dB), additional alterations in GABA metabolism are observed: mainly large increases in GABA turnover rates (from 40% to three- to fourfold). The Rb2 subline displays a greater number of alterations (increases of turnover rates in pons, cerebellum, anterior and posterior colliculus, amygdala, olfactory bulbs and tubercles, striatum, and frontal cortex) than the Rb1 subline (increases of turnover rates in cerebellum, posterior colliculus, olfactory tubercles, raphe, and frontal cortex and a decrease in hypothalamus). In the Rb3 subline, increases of the turnover rate in amygdala and olfactory tubercles and decreases in olfactory bulbs and hippocampus are observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acoustic Stimulation↗
PubMed1987

Thyroid hormones alter mRNA activity profiles of differentiated 3T3-L1-cells.

The influence of thyroid hormones on the gene expression of 3T3-L1-adipocytes was examined. mRNA activity profiles were investigated by in vitro-translation and 2D-electrophoresis. Seven protein spots out of 210 were sensitive to 3,5,3'-triiodothyronine (T3). All proteins increased from hypothyroid to hyperthyroid status. Additionally two spots increased from hypothyroid to T3-substituted and euthyroid status. There is evidence for the existence of protein S14 in differentiated 3T3-L1-cells, as part of spot 5.

Adipose Tissue↗
PubMed1986

Patterns of juvenile criminal activity as a function of demographic, family, and individual variables.

Patterns of juvenile criminal activity were investigated with respect to differences in a range of demographic, family, and individual variables. Subjects were 89 juveniles who were referred to a county juvenile services center (70 males, 19 females; 78 Caucasians, 10 Blacks, 1 Oriental; mean age = 15.7). Discriminant function analyses were used to assess the discriminating power of the variables across crime categories (felony vs. misdemeanor), crime subcategories (person vs. property), number of prior referrals (none vs. one or more), and grade level (junior vs. senior high). All groups could be discriminated effectively on the basis of Wilks' lambda and associated chi-square tests of statistical significance.

Adolescent↗