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Biomedical subjects

R Dubois

Publications and source records attributed to R Dubois.

At least 19 recordsLinked to original sources
PubMed1996

Altered sensory processing in the somatosensory cortex of the mouse mutant barrelless.

Mice homozygous for the barrelless (brl) mutation, mapped here to chromosome 11, lack barrel-shaped arrays of cell clusters termed "barrels" in the primary somatosensory cortex. Deoxyglucose uptake demonstrated that the topology of the cortical whisker representation is nevertheless preserved. Anterograde tracers revealed a lack of spatial segregation of thalamic afferents into individual barrel territories, and single-cell recordings demonstrated a lack of temporal discrimination of center from surround information. Thus, structural segregation of thalamic inputs is not essential to generate topological order in the somatosensory cortex, but it is required for discrete spatiotemporal relay of sensory information to the cortex.

Animals↗
PubMed1992

Chronic pancreatitis beginning in childhood and adolescence.

We identified 10 patients with symptoms beginning before the age of 20 years in a group of 69 patients with proven chronic pancreatitis. Six of the 10 patients were women. There was a family history of pancreatitis in three patients and alcohol exposure in seven patients. Three patients were dependent on narcotics at the time of presentation. Six of the 10 patients had pancreatic duct dilatation to 10 mm or more in diameter during observation. These six patients underwent pancreaticojejunostomy, with clinical improvement in five patients. The median time of follow-up was 19 years from presentation. No patient developed diabetes and one developed malabsorption. Only three patients were free of pain, but four other patients had only mild episodes that rarely required hospital admission. One patient died of metastatic abdominal carcinoma of unknown origin 51 years after developing familial pancreatitis. Chronic pancreatitis beginning at a young age is sufficiently common to merit special awareness. It is compatible with prolonged survival, and pancreaticojejunostomy may help if the pancreatic duct reaches sufficient size. The disease does not seem to burn out with time.

Adolescent↗
PubMed1991

Effect of nomegestrol acetate on spinability, ferning and mesh dimension of midcycle cervical mucus.

A study was carried out in order to determine the impact of Nomegestrol acetate on the human cervix and to evaluate the ability of changes induced in cervical mucus to render the cervical canal hostile to spermatozoa at midcycle. Under the influence of Nom Ac, loss of spinability, absence of ferning pattern and drastic tightening of the glycoprotein meshwork rendered midcycle mucus very similar to that elaborated during physiological states under total progesterone dominance. The results obtained in this study gave clear evidence that Nomegestrol acetate may provide cervical blocking thereby preventing sperm transport to the uterine cavity.

Adult↗
PubMed1989

Doppler estimation of pressure gradient in pulmonary stenosis: maximal instantaneous vs peak-to-peak, vs mean catheter gradient.

We undertook a study to identify the hemodynamic significance of a Doppler-derived gradient across a stenotic pulmonary valve. Furthermore, we attempted to define the optimal plane for velocity data acquisition. A total of 17 children with valvar pulmonary stenosis were evaluated using Doppler echocardiography. Flow-velocity profiles were obtained from both the parasternal and subxiphoid windows. Ten of 17 patients were studied before and after balloon valvotomy. Therefore, 27 different transvalvar gradients were assessed by Doppler and these data were compared with the catheter-derived maximal instantaneous, peak-to-peak, and mean pressure gradients. The maximal Doppler gradient correlated well with the catheter-derived peak-to-peak pressure gradient (r = 0.95) and catheter maximal instantaneous pressure gradient (r = 0.95). Although these correlation coefficients were similar, the Doppler maximal gradient consistently overestimated the peak-to-peak catheter gradient by as much as 25%-40%. Such an overestimation was not observed when we compared the maximal Doppler gradient with the catheter-derived maximal instantaneous gradient. Moreover, the regression line of the latter comparison closely approximated the line of identity. The correlation coefficient between Doppler mean and catheter mean gradients was only 0.91. Doppler velocities were best derived when multiple transducer positions were employed to interrogate pulmonary artery velocity.

Blood Pressure↗
PubMed1986

Trypanosoma musculi infection in the CBA/N mouse.

The infection of B-cell deficient CBA/N mice by Trypanosoma musculi resulted in a higher parasitaemia, delayed recovery, and a defective antibody response (IgM and IgG1). CBA/N mice were thus less efficient than CBA/J in controlling the infection. These results indicate that B-cells are involved in the immunological control of this parasite.

Animals↗
PubMed1984

Modulation of ventricular parasystole by extraneous depolarizations.

The ectopic cycle length of a ventricular parasystole was influenced in a predictable fashion (modulated) by nonparasystolic beats. Although the interectopic intervals were not multiples of the ectopic cycle length (as in "classical" parasystole), the diagnosis could be established because: a) nonparasystolic beats falling during the first half of the cycle produced an 8-12% shortening of the ectopic cycle length; and b) nonparasystolic beats occurring during the second half of the cycle decreased the ectopic cycle length by 9-14%. The events occurring in this case are further proof that the classical criteria for the diagnosis of parasystole have to be reevaluated.

Arrhythmias, Cardiac↗
PubMed1983

Assessing the preovulatory LH surge with a three-hour radioimmunoassay.

A rapid, simple and precise luteinizing-hormone (LH) assay would appear to be the most appropriate approach to predicting ovulation in in vitro fertilization and artificial insemination programs based on natural ovulation. Therefore, we modified a standard LH radioimmunoassay into a convenient assay providing reliable results within three hours after blood collection. The antigen-antibody reaction takes place during a two-hour incubation under nonequilibrium conditions at 20 C. The immune complex is precipitated with polyethyleneglycol containing sheep anti-rabbit antibodies. The standard curve of the rapid method shows characteristics (ED-50, slope, sensitivity, range, precision) similar to those of the regular assay, and the results of both assays are comparable over a wide range of values. The interassay variation is less than 15%. The preovulatory LH surge has been evaluated in 32 cycles (20 women) with successive dosages of daily blood samples taken every three to five hours. LH surges vary in shape and duration. In most of the cycles the LH surge is relatively steep, and the maximum LH value is observed within 17 hours after the beginning of the LH rise in 87% of the cycles. Detection of the initial rise in the LH peak on the basis of successive assays of frequent blood samples seems to be reliable in predicting ovulation.

Adult↗
PubMed1982

[Dibekacin treatment of infectious complications of abdominal surgery].

Major abdominal surgery often involves severe postoperative infections with various pathogens: enterobacteriaceae, staphylococcus and anaerobic bacteria. For this reason a strong antibiotherapy can be necessary in the case of an infectious disease. Dibekacin was administered at a daily dose of 3 mg/kg to 22 patients suffering from very severe postoperative infection. In all the cases dibekacin was combined with a beta-lactamine and in some with nitro-imidazole derivative. The results were especially favourable in all of these cases and a good tolerance was observed.

Abdomen↗
PubMed1981

A ruby cystotome.

Explore the source record for details and available documents.

Cataract Extraction↗
PubMed1981

[The diagnosis of adnexal masses of a gynaecological nature using ultrasound: an analysis of the specificity and reliability of the examination (author's transl)].

A retrospective analysis has been carried out on 118 cases of gynaecological tumours of the adnexae. The reliability of ultrasound examination is about 90% for evaluating the existence, the size, the localisation and the structure of these masses. The principal mistakes occurred when the technique was poor, when the interpretation of the picture was faulty and when loops on intestine were in the way. It is possible to diagnose accurately simple ovarian cysts, dermoid cysts and adenocarcinomatous cysts. It is difficult to be specific as far as tubal pathology is concerned, and particularly in infections and ectopic pregnancies. Echotomography of the pelvis has become accepted among the battery of paraclinical gynaecological examinations. It has become of greatest importance in these examinations and particularly when exploring adnexal gynaecological masses. The purpose of this retrospective work has been to evaluate the reliability of ultrasound diagnosis of the nature and origin of masses.

Adult↗
PubMed1979

The variation of the mean spinability of human cervical mucus throughout the various stages of reproductive life. Automatic measurement and statistical study.

The evolution of the mean spinability value of human cervical mucus was studied by means of an automatic device throughout the menstrual cycle and pregnancy and during and after the onset of menopause. The automatic measurement brings to light the major drawbacks presented by manual methods: values previously obtained should be considered as underestimated. The mean spinability value recorded from cyclic mucus exhibits a very significant increase at mid-cycle. Graphical analysis demonstrates that only small differences in the mean spinability value occur as pregnancy proceeds. A progressive and regular decrease in the mean spinability value can be recorded from the very beginning of the menopause. However, the spinability values observed in premenopausal mucus are noticeably higher than those recorded after the onset of the menopause. The numeric data furnished by the automatic measurement are discussed in terms of statistics.

Cervix Mucus↗