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Biomedical subjects

A David

Publications and source records attributed to A David.

At least 181 records · Page 10Linked to original sources
PubMed1993

Fine specificity of monoclonal antibodies directed at human T cell receptor variable regions: comparison with oligonucleotide-driven amplification for evaluation of V beta expression.

Seven distinct anti-human T cell receptor (TcR) V region monoclonal antibodies (mAb) were generated by immunizing mice with either human T cell lines or transfected murine cells expressing human TcR V beta genes. The specificity of these reagents was determined as follows: T cells recognized by each mAb were purified from the peripheral blood of healthy donors and TcR transcripts expressed in these cells were analyzed using oligonucleotide-driven amplification and cDNA sequencing. Four mAb were found to delineate the V beta 3, V beta 8, V beta 17 and V beta 19 subfamilies, respectively. The remaining reagents recognize subsets within the V beta 2, V beta 5 and V beta 13 subfamilies. Reactivity of the mAb with circulating T cells from 18 unrelated healthy individuals was determined. Limited variability was found from an individual to another. In four donors, mAb staining was compared to oligonucleotide-driven amplification for evaluation of V beta 3, V beta 8, V beta 17 and V beta 19 subfamily expression in the peripheral blood. Although the V gene subfamily-specific oligonucleotides used in this study belong to a carefully controlled series, our results show that this method does not give an accurate estimate of the percentage of peripheral T cells expressing a given TcR beta chain. The present data confirm the necessity to establish a complete set of well-characterized monoclonal reagents to study human T cell responses.

Animals↗
PubMed1993

Asymptomatic carrier of two CFTR mutations: consequences for prenatal diagnosis?

The cystic fibrosis (CF) gene has been observed to have the highest frequency of mutations in the Caucasian population. Prenatal diagnosis can now be performed with a high degree of accuracy since the identification of most of the gene's mutations, as well as the characterization of intragenic markers. However, the observation of a distribution of clinical phenotypes increases the need to identify a mild phenotype and avoid false-negative diagnosis. By screening most of the exons of the CFTR gene, we showed that a supposed obligate carrier of CF was in fact an asymptomatic affected woman.

Base Sequence↗
PubMed1993

Cognitive impairment in patients with chronic fatigue: a preliminary study.

Subjective impairment of memory and concentration is a frequent complaint in sufferers from chronic fatigue. To study this, 65 general practice attenders identified as having chronic fatigue were administered a structured psychiatric interview and a brief screening battery of cognitive tests. Subjective cognitive impairment was strongly related to psychiatric disorder, especially depressed mood, but not fatigue, anxiety, or objective performance. Simple tests of attention and concentration showed some impairment but this was influenced by both fatigue and depression. Subjects with high levels of fatigue performed less well on a memory task requiring cognitive effort, even in the absence of depression. There was no evidence for mental fatiguability. The relationship between depression, fatigue, and cognitive function requires further research.

Adolescent↗
PubMed1993

The role of catecholamines in muscular growth.

This paper reports on an experiment concerning the involvement of catecholamines in the biosynthesis of nucleic acids and proteins at muscular levels, using various types of skeletal muscles (psoas, diaphragm, soleus) and heart muscles from male Wistar rats treated with adrenalin. Assessment of the biosynthetic processes was made by the uptake level of 3H thymidine, 3H uridine, and 3H triptophan in the muscles. The experiment showed the followings: a) nucleic acids and protein synthesis stayed unchanged in the psoas; b) adrenalin stimulated the uptake of the radioactive precursors in the diaphragm and soleus, and c) the biosynthetic processes were inhibited in the myocardium by adrenalin administration. Though adrenalin is known to stimulate proteic synthesis in the skeletal muscle, our study showed that this process occurs only in certain types of muscles (with slow contraction). Inhibition of proteic synthesis in the myocardium in the presence of adrenalin might be one of the cellular mechanisms involved in cardiac failure.

Animals↗
PubMed1993

The role of catecholamines in the distribution of steroid hormones in the striated and cardiac muscle.

Loss of muscular strength is a well-known component of the clinical picture many endocrine diseases and is often their predominant aspect. It has recently been proved that the cytoplasmatic receptors for steroid hormones (SH) are artefacts of the fixation techniques and that they are attached to the internal surface of the cell membrane. Our experiment was made on male and female. Wistar rats which were tested for the level of radioactively labelled steroid hormones (3H and HD3H hydrocortisone; 3H testosterone, TS3H; 3H estrone, FS3H) in various types of skeletal muscles (from rapid to slow) and cardiac muscle before and after adrenalin administration. Before adrenalin administration one noticed: (a) a significantly higher level of HD3H (p < 0.05) in the female skeletal muscle; (b) in the femoral biceps and psoas, a significantly higher distribution of TS3H in males (p < 0.01), whereas in the diaphragm and the heart, there were no significant differences between sexes; (c) there are significant differences between sexes as regards the ES3H level in any of the studied muscles. After adrenalin administration there was a significant decrease in the level of labelled SH uptake in all experimental schemes. It is possible that adrenalin block the HS diffusion through the plasma membrane or even their binding to specific receptors.

Animals↗
PubMed1993

[Precocious puberty revealing Bourneville tuberous sclerosis].

BACKGROUND: Benign tumors are seen in tuberous sclerosis. They are found in many organs, and the precocious puberty due to hypothalamic hamartoma and tuberous sclerosis has been reported. However, precocious puberty exceptionally reveals the tuberous sclerosis. CASE REPORT: A 2 month-old boy was admitted because of the fortuitous discovery of polycystic renal disease. Precocious puberty developed at 13 months with enlargement of the penis and testes, appearance of pubic hair, acne and deepening of the voice. Linear growth was recently accelerated and the bone maturation was advanced. Plasma testosterone was elevated (460 ng/100 ml) and LH-RH injection induced rapid rises in plasma LH (2.6 to 28 mUl/ml) and FSH (2 to 8 mUl/ml). Brain imaging techniques (CT scan and NMR) showed a hypothalamic hamartoma and periventricular calcified lesions. Examination with the Wood lamp identified two white leaf macules in the dorsal area. Administration of an analogue of LH-RH effectively reduced the manifestations of precocious puberty. CONCLUSION: Tuberous sclerosis is exceptionally revealed by precocious puberty. The association of polycystic disease and precocious puberty has never before been reported in tuberous sclerosis.

Hamartoma↗
PubMed1992

Schizophrenia and city life.

Prevalence of schizophrenia and rates of first admission to hospital for this disorder are higher in most modern industrialised cities, and in urban compared with rural areas. The "geographical drift" hypothesis (ie, most schizophrenics tend to drift into city areas because of their illness or its prodrome) has remained largely unchallenged. We have investigated the association between place of upbringing and the incidence of schizophrenia with data from a cohort of 49,191 male Swedish conscripts linked to the Swedish National Register of Psychiatric Care. The incidence of schizophrenia was 1.65 times higher (95% confidence interval 1.19-2.28) among men brought up in cities than in those who had had a rural upbringing. The association persisted despite adjustment for other factors associated with city life such as cannabis use, parental divorce, and family history of psychiatric disorder. This finding cannot be explained by the widely held notion that people with schizophrenia drift into cities at the beginning of their illness. We conclude that undetermined environmental factors found in cities increase the risk of schizophrenia.

Adult↗
PubMed1992

Hypoglossia-hypodactylia syndrome with jejunal atresia in an infant of a diabetic mother.

Despite advances in therapy for maternal diabetes, pregnancies of diabetic women remained at an increased risk of spontaneous abortion or delivery of an infant with major malformation. We report on an infant of a diabetic mother with hypoglossia-hypodactylia associated with complete jejunal atresia. A common pathogenesis for these 2 malformations could be a vascular disruptive mechanism with in utero arterial thrombosis.

Adult↗
PubMed1992

A case of primary non-Hodgkin lymphoma of the pancreas.

Non-Hodgkin pancreatic lymphoma is a rare disease. Its diagnosis is difficult without histological examination. Ultrasonographic, computed tomodensitometric, and endoscopic retrograde cholangio-pancreatographic findings are not pathognomonic. The better prognosis of these tumors, compared to adenocarcinoma, and their sensitivity to chemotherapy, implies the need for pathologic examination of every pancreatic tumor.

Adult↗
PubMed1992

Digito-reno-cerebral syndrome: confirmation of Eronen syndrome.

In 1985, Eronen et al. described a new autosomal recessive syndrome with absence of the distal phalanges of the toes and fingers, renal defect and cerebral anomalies (dilated ventricles or seizures). Two unrelated children affected by this syndrome enable us to accept its autonomy and delineate its nosology. Variability of the expression of the renal and cerebral manifestations is emphasized.

Abnormalities, Multiple↗
PubMed1992

The assessment of insight in psychosis.

An assessment schedule was used to determine the nature of insight in 91 mixed psychotic patients, and to examine its distribution and associations. While all the components of the schedule intercorrelated significantly, scores for compliance were only weakly related to those for ability to label psychotic phenomena as abnormal. Compliance and illness recognition were related to IQ. Total insight score was inversely correlated, moderately, with a global measure of psychopathology derived from the PSE, and was less in patients involuntarily committed. Age, sex, diagnosis, and the number of previous hospital admissions had little effect. The results support the notion that insight is not a unitary concept.

Adult↗
PubMed1992

Plasma neurotransmitter profile during different phases of the ovulatory cycle.

The influence of the different phases of the menstrual cycle on platelet-poor plasma norepinephrine (NE) and serotonin (5HT) was examined in 17 normal volunteers. The examinations were performed consecutively during 3 phases of the ovulatory cycle: 1) follicular phase, 2) ovulation, and 3) luteal phase. This investigation was initiated after a preliminary study in 51 volunteers showed wide and consistent variations of plasma NE and 5HT during the different phases of the cycle. Since in this first group the determinations had not been performed consecutively in the same subjects, and the changes observed in the different phases of the cycle could reflect interpersonal variations, the determinations were performed consecutively in a second group, concomitantly with serum estradiol (E2) and LH measurements. The results showed a decrease in plasma 5HT from the follicular phase [144.3 +/- 69.3 nmol/L (+/- SD)] to ovulation (55.7 +/- 41.4; P less than 0.001) and a subsequent increase in the luteal phase (141.3 +/- 96.4; P less than 0.01). The nadir in plasma 5HT showed an inverse correlation with serum LH (r = -0.07). Plasma NE increased from the follicular phase (1226.5 +/- 475.1 pmol/L) to ovulation (1694.0 +/- 564.4; P = 0.027) and reached a maximum in the luteal phase (2335.0 +/- 728.2; P = 0.0034). This rise correlated positively with serum E2. In conclusion, plasma 5HT and NE vary with the different phases of the menstrual cycle. Plasma NE rises during ovulation and seems to to correlate positively with serum E2 levels. Plasma 5HT reaches a nadir during ovulation and correlates inversely with serum LH.

Adult↗