Biomedical subjects

J Brunet

Publications and source records attributed to J Brunet.

At least 19 recordsLinked to original sources

PubMed1992

Lumbar bone mineral content measured by dual energy X-ray absorptiometry in newborns and infants.

Dual energy X-ray absorptiometry (DXA), a non-invasive method for measuring small amounts of mineral, was used to assess the bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine (5 vertebrae) in 57 newborns (on day 1-2) and 22 infants (1-24 months of age). A modified high-resolution program (Hologic) allowed us to assess BMC and BMD with a precision higher than 2.4% and 1.5%, respectively. In newborns, BMC and BMD correlated positively with birth weight, body area, length and gestational age: r = 0.73, 0.71, 0.63 and 0.60, respectively, for BMC; and r = 0.59, 0.58, 0.54 and 0.53, respectively, for BMD. In infants, both BMC and BMD were highly correlated with weight, age, length and body area over two years (r = 0.94 or better in each instance). The data provide normal values for lumbar spine BMC and BMD in newborns (gestational age 31-40) and infants up to two years of age; DXA appears to be an excellent and safe tool for pediatric bone mineral measurements.

Absorptiometry, Photon↗

PubMed1992

Dual energy x-ray absorptiometry measurement of bone mineral content in newborns: validation of the technique.

To evaluate the applicability of dual energy x-ray bone absorptiometry in newborns, precision and accuracy of the method was tested for very small quantities of mineral ranging from less than 0.5 g to about 4 g of hydroxyapatite using a Hologic QDR 1000 instrument. For six femurs excised from preterm stillborns, the mean precision for bone mineral content (BMC) and bone mineral density (BMD) was 1.2 and 0.8%, respectively. Accuracy based on ash weight indicated a mean overestimation of about 7%. In vivo, the precision was assessed by measuring lumbar spine BMC and BMD (L1 to L5) two or three times in 10 newborns (gestational age, 33 to 40 wk). The mean coefficients of variation were 2.40 and 1.55% for BMC and BMD, respectively. Lumbar spine BMC and BMD were also measured once in 30 full-term infants. Values ranged from 1.17 to 3.90 g for BMC and from 0.192 to 0.356 g/cm2 for BMD. The present study shows that dual energy x-ray absorptiometry provides a valuable new tool for the assessment and management of BMC in low birth weight infants and neonates in general.

Absorptiometry, Photon↗

PubMed1991

[In vitro evaluation of the maximal possible deformation imposable on the median collateral ligaments in rabbits].

With this study, we identified the maximal level of deformation applicable to medial collateral rabbit ligaments in vitro. According to scanning electron microscopy photographs of ligaments fixed at different elongation level 0% (n = 5), 5% (n = 4), 6% (n = 5), 8% (n = 5), 10% (n = 7), 15% (n = 4) and 20% (n = 4), we concluded that a 6% deformation would be optimal. At that level, the collagen fiber undulation are completely unstretched, and still, no collagen ruptures could be observed.

Animals↗

PubMed1990

A scanning electron microscopic study of rabbit ligaments under strain.

For the purpose of determining the critical strain level for ligaments submitted to mechanical stimulation, rabbit medial collateral ligaments (MCLs) were subjected to different predetermined strain levels and then examined by scanning electron microscopy (SEM). Below 10% strain no evidence of disruption of the collagenous entities has been found. At about 10% strain, the ligaments were still intact macroscopically but SEM revealed numerous broken thin collagen fibers. At 20% strain, ruptures of thick collagen fibers bundles (5 to 10 mu in diameter) were found. These findings suggest that when using mechanical stimulation of ligaments, care must be taken to not exceed 10% strain level.

Animals↗

PubMed1989

Postpubertal cryptorchism. Morphofunctional study with special reference to Leydig's cells.

In a group of 17 patients of postpubertal age with unilateral (n = 15) or bilateral (n = 2) cryptorchism, a significant decrease in the tubular diameter was observed, in addition to Leydig cell hyperplasia (many with cytoplasm vacuolization and/or atrophy) in both the cryptorchid testes and in the contralateral scrotal testes. The number of testosterone-positive Leydig cells in testicular tissue sections, studied with peroxidase-antiperoxidase, was diminished in the cryptorchid testes, whereas in the contralateral scrotal testes it was similar to the control group. Together with normal testosterone levels and elevated luteinizing hormone and follicle-stimulating hormone levels in peripheral blood, this leads us to think of a compensated dysfunction of the Leydig cells. This possible lower testosterone production by the Leydig cells in the cryptorchid testis is not borne out morphologically, where the volume of the organelles is similar to the contralateral scrotal testes.

Adolescent↗

PubMed1988

[Recurrent infections caused by Salmonella typhimurium].

We report the case of a 27 month-old girl with recurrent Salmonella typhi murium infections. The study of the neutrophil cells showed a transitory selective deficiency of the chemiluminescent response. After 5 months of pefloxacine therapy, recovery was obtained.

Anti-Bacterial Agents↗

PubMed1988

[Aerobic and aero-anaerobic bacterial flora of the nasal cavities of lambs].

On the basis of bacteriological examinations carried out on 415 intranasal swabs, aerobic and aero-anaerobic respiratory microbes were studied in lambs. A great diversity of bacteria has been found (in total 35 bacterial species and genus have been identified). This flora is characterised by the presence of gram positive cocci with a gram negative strain included in genus Moraxella and connected with Moraxella bovis species.

Animals↗

PubMed1988

[Metastatic neuroblastoma with secondary hypersecretion of vasoactive intestinal peptide].

A 18-month-old boy with stage 4 neuroblastoma needed intensive care because of prerenal acute renal failure related to an intractable watery diarrhoea syndrome occurring 10 months after the diagnosis of the primary tumor. This diarrhoea was in relation with a late hyperproduction of vasoactive intestinal peptide by the relapsing neuroblastoma itself and stopped with intravenous somatostatin administration.

Diarrhea, Infantile↗

PubMed1977

[Health services priorities in Quebec].

The reform of health services in Quebec, of which the most important stage was the creation of the Department of Social Affairs and the Quebec Health Insurance Board, has solved certain problems such as the inaccessibility to care because of the cost, the paucity of medical personnel and the excessive increase in the cost of the services offered to hospital patients. A critical analysis of both the reform and its practical consequences points to certain conclusions which, far from rejecting the principle of the reform, indicate none the less various possibilities for reorienting its priorities. Observing the rate of recourse to health services as well as the attitudes and conduct of health professionals have helped us to identify the causes of certain tendencies inspired by the incentives inherent in the reform. The organization of health services in Quebec must be oriented toward new priorities: the prevention and treatment both of environmental diseases and diseases associated with ageing plus the definition of a global approach to public health.

Attitude of Health Personnel↗

PubMed1975