Artificial gravity and space travel: can humans survive long treks across interplanetary distances?
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Biomedical subjects
Publications and source records attributed to L David.
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Car collisions are a major cause of death in young children. Many of these deaths could be avoided by using child restraint systems. In May 1990, an illustrated leaflet, describing the utility for a child to be seated on the backseat and belted, was distributed to all children in the primary schools of the Rhône department. To assess the impact of this program "Ceint et sauf" (belted and safe), questionnaires were filled by teachers, once before, and twice after leaflets were distributed. These questionnaires allowed to estimate, in each classroom, the proportion of children who were seated and belted on the backseat during the last day of the preceding week. Answers to questionnaires were received from 673 out of the 5,249 classrooms of the Rhône department (12.8%). The sample was representative with regard to public-private sector, geographical area, and size of schools. Among those who were on the backseat, the proportion of children who were belted increased from 32 to 47%. The proportion of children correctly protected remained low: at the end of the program, only 39% of all children were on the backseat and belted. Despite a methodology unadequate for evaluation, this survey underlined the low level of protection of children in cars in France. Other actions, well evaluated, are needed to promote the use of child restraint systems in France.
The authors report on the case of a child with the nephrotic syndrome complicated by thrombosis of superior longitudinal sinus, bilateral massive pulmonary embolism resulting in a sudden death. A dramatic deficiency in factor XII was demonstrated; the pathophysiology and management of such an abnormality are discussed.
In an attempt to evaluate the relationship between c-erbB-2 expression and/or gene amplification, DNA ploidy and morphology, wall penetration, lymphatic permeation, and vascular invasion, we studied a series of 87 primary gastric carcinomas and their respective metastases (n = 335) using immunohistochemistry and performed DNA analysis of 30 primary tumors and 10 metastases from eight cases. Flow cytometry of fresh or frozen material was performed in 79 primary tumors. Five out of 87 primary tumors (5.7%) and 17 out of 335 lymph node metastases (5.1%) showed unequivocal membrane immunostaining for c-erbB-2. Seven out of 30 primary tumors (23.3%) showed gene amplification while amplification was identified in four out of 10 metastases (40.0%) from three patients. Eight tumors (9.2%) showed c-erbB-2 protein immunoreactivity, gene amplification, or both. One of these cases showed c-erbB-2 protein immunoreactivity only in the metastatic deposits, while gene amplification could be identified in the primary tumor. Three primary tumors showed gene amplification, but immunoreactive cells could not be identified. In no case was protein overexpression identified in the absence of gene amplification. Five cases with c-erbB-2 expression/amplification were well/moderately differentiated, and all the eight cases with c-erbB-2 expression/amplification disclosed aggressive features. Lymphatic permeation/lymph node metastases were found in all the cases and seven cases showed vascular invasion as well. In one case, there was also a liver metastasis. Two cases were early gastric carcinomas (T1sm) showing lymphatic permeation/nodal metastases and venous invasion. Six cases were aneuploid.(ABSTRACT TRUNCATED AT 250 WORDS)
A 46,XX,r(17) karyotype was observed in a 9-year-old infant with short stature, moderate mental retardation but without other physical abnormality. Eight cases with an r(17) have since been reported: 4 can be compared with our patient, one was detected by amniocentesis, and 3 have Miller-Dieker syndrome. Submicroscopic deletions in the subband p13.3 are probably the cause of Miller-Dieker syndrome. They are present in some cases of r(17) but, in others, this short arm region is entirely preserved.
Immunohistochemical study of the expression of simple mucin-type carbohydrate antigens (Tn, sialosyl-Tn, T and sialosyl-T) was performed using specific monoclonal antibodies in the mucosa adjacent to gastric carcinomas histologically appearing unaffected (n = 58), and in primary gastric carcinomas (n = 87) and their metastases (329 lymph nodes and two liver metastases). Normal-looking mucosas: Tn antigen expression was identified in all the cases; sialosyl-Tn in eight cases; T antigen was never expressed and sialosyl-T antigen was observed in four cases; the expression of these antigens was distinctly limited to the cytoplasm, mostly in the supranuclear (Golgi) area. All the mucosas with intestinal metaplasia showed sialosyl-Tn expression in the goblet cells. Gastric carcinomas: 80 cases (91.9%) stained for Tn antigen, 69 cases (19.3%) expressed sialosyl-Tn antigen, 18 cases (20.7%) expressed T antigen and 17 cases (19.5%) stained for sialosyl-T antigen. In contrast to normal mucosa, carcinoma cells expressed simple mucin-type antigens both at the cytoplasm and at the cell membrane. Most primary carcinomas were concurrently stained for Tn and sialosyl-Tn antigens alone (41.1%), or together with T antigen or sialosyl-T antigen (28.7%). We found a close relationship between the expression of simple mucin-type carbohydrate antigens in the primary tumours and their respective metastases. T antigen (and sialosyl-T antigen) expression was correlated with the wall invasiveness of the tumours. The 18 tumours expressing T antigen and 16 out of the 17 tumours expressing sialosyl-T antigen had nodal metastases and/or sialosyl-Tn expression and the aggressiveness of the tumours (wall penetration, lymph node metastasis and venous invasion). No significant differences were observed between positive and negative tumours for Tn, sialosyl-Tn, T and sialosyl-T antigens regarding the morphologic at type, growth pattern, ploidy or lymphoid infiltrate of the primary tumours.
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Thin-layer chromatography coupled with flame ionization detection was used to develop a method to separate and to determine simultaneously three polyether carboxylic ionophore antibiotics (abierixin, nigericin and grisorixin) produced by Streptomyces hygroscopicus NRRL B 1865. Various proportions of chloroform, methanol and formic acid (or acetic acid as a substitute for formic acid) were used in the developing solvent to determine changes in RF values of the antibiotics and to allow conditions for maximum resolution to be obtained. Development on Chromarods SII with chloroform-methanol-formic acid (97:4:0.6, v/v/v) gave satisfactory and reliable separations of the three polyether antibiotics. Under these conditions, the internal standard methyl desoxycholate was found to be suitable for their simultaneous determination in the lipid extracts of Streptomyces hygroscopicus NRRL B 1865.
Recombinant interleukin-2 (rIL-2) is a new promising treatment for cancer, but is associated with severe renal toxicity. This study is the first to analyse the renal effects of rIL-2 in children. Twenty-one cycles of continuous rIL-2 infusion were studied in 15 patients; mean age was 6.9 years and average weight 18.9 kg. Interstitial fluid retention and oliguria (baseline, 1.7 ml/kg per hour; nadir, 0.5 mg/kg per hour) were associated with hypotension (baseline, 101/56 mm Hg; nadir, 85/43 mm Hg) and decreased intravascular volume (plasma renin activity increased x 10). Weight gain (+7.9%) was observed in 13 cycles whereas weight loss (-6.3%) was shown in 8 cycles because of digestive and cutaneous losses, mainly in the youngest patients. This prerenal azotaemia was characterized by a decrease in creatinine clearance (from 101 to 36 ml/min per 1.73 m2) and a low fractional excretion of sodium (FENa) (from 0.70% to 0.09%). Hypotension and hypovolaemia needed vascular filling (n = 12), dopamine (n = 7) and interruption of rIL-2 (n = 2). Most abnormalities occurred as early as day 2 of therapy and were always reversible after a short period with sodium leakage (diuresis = 2.2 ml/kg per hour, FENa = 2.01%). Hypophosphataemia was associated with low urinary excretion of phosphorus, suggesting an increased uptake of inorganic phosphorus by rapidly proliferating lymphoid cells.
We update and review a large pedigree originally described by Santos and Magalhães with familial gastric polyposis and a high incidence of gastric cancer. The present observation of male-to-male transmission of the disease clearly demonstrates the autosomal dominant pattern of inheritance. The histologic review of the polyps present in several members of the family allowed the diagnosis of hyperplastic polyposis. Eight members of the family (two with concomitant gastric pathology) have severe cutaneous psoriasis. This finding may represent the existence of two different disorders segregating in the family or, alternatively, pleiotropic manifestations of the same gene.
Congenital megalo-urethra is a malformation of the male urethra with a major dilatation of its penile part without obstruction downwards. It is either due to hypoplasia or agenesia of spongy tissue. Two types are described, scaphoid and fusiform types, according to the presence or the absence of erectile tissue. Megalo-urethra is a rare condition, and 56 cases were previously reported until 1987. A new case of this severe anomaly is reported and management discussed.
The authors report a case of right ventricle endomyocardial fibrosis in a 6-year-old boy. Particular attention is paid to the discussion of the new methods for diagnosing and treating these conditions, namely echocardiography, endomyocardial biopsy and surgery.
Two siblings born from consanguineous parents experienced infantile nephrotic syndrome with ocular and neurological abnormalities; the boy also had a micropenis; both patients died before age 1 year. An initial renal biopsy followed by a two-step binephrectomy allowed good histological assessment of disease progression in one patient. The progression of the lesions was characterized by mesangial involvement, then an extensive extracapillary proliferation and tubular dilatations with a high mitotic activity of the epithelium and nuclei of unequal size. The main features involved major ultrastructural changes of the glomerular basement membrane. These two patients may represent a new disease entity or a severe form of diffuse mesangial sclerosis, with autosomal recessive inheritance.
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Hypocalcemia is commonly observed in the neonatal period and is usually transient from a few days to a few weeks. On only rare occasions is neonatal hypocalcemia permanent and secondary to congenital hypoparathyroidism caused by either isolated absence of parathyroid glands or in association with other malformations. Most cases of neonatal hypocalcemia fall into one of two clinical categories. Namely early neonatal hypocalcemia occurs in 24-48 h of life and it is usually observed in premature infants or infants of diabetic mothers. Late neonatal hypocalcemia is observed at the end of the first week of life. In addition of these two major categories, neonatal hypocalcemia may occur in association with hypomagnesemia.
The bone mineral density (BMD) of the lumbar spine (L1-L4) was measured by dual energy x-ray absorptiometry (Hologic QDR 1000) in 135 healthy caucasian children, aged 1-15 yr, and values were correlated with age, height, weight, body surface, bone age, pubertal status, calcium intake, vitamin D supplementation, and serum bone gla protein. BMD increased with age in children of both sexes (r = 0.88; P less than 0.001) from 0.446 +/- 0.048 g/cm2 at 1 yr to 0.625 +/- 0.068 g/cm2 at 10 yr and 0.891 +/- 0.123 g/cm2 at 15 yr of age. The increase was steeper at the time of puberty, reaching values above 0.80 g/cm2 after puberty was achieved. There were no significant differences between boys and girls, except at the age of 12 yr when BMD was higher in girls than in boys (P = 0.007), probably because of the earlier onset of puberty in females. BMD was also highly correlated with height, weight, body surface, and bone age. BMD was not correlated with calcium intake when age was held constant, nor with vitamin D supplementation. Serum bone gla protein showed a steady increase during childhood, with peak values at 11-12 yr of age, and was weakly but significantly correlated with BMD (r = 0.27; P = 0.007). Because of low irradiation exposure, rapid scanning, and high precision, dual energy x-ray absorptiometry is a noninvasive method which is well adapted to the child. It should be helpful in the investigation and follow-up of children with diseases impairing bone metabolism.
A 12 year-old girl with a family of Charcot-Marie-Tooth neuropathy was referred to us with mild proteinuria without hematuria or renal insufficiency; a renal biopsy specimen showed focal glomerulosclerosis. Two years later, proteinuria and renal function were quite stable and there was no arterial hypertension. Of 13 other cases in the literature, the outcome of renal involvement has the same profile:proteinuria at onset with or without microhematuria, sometimes with nephrotic syndrome; the prognosis is often poor, since 9 out of 13 patients have end-stage renal failure after 6 months to 17 years of follow-up. The pathological examination show focal glomerulosclerosis in most cases. Nerve deafness is uncommon in Charcot-Marie-Tooth disease but was present in 7 out of 13 patients with the nephritis. Such an association may be a variant of the dominant autosomal form of the disease, whose gene is located on chromosome 1.
Twenty cases of membranous glomerulonephritis have been diagnosed between 1978 and 1988 in children (13 girls, 7 boys) aged 4 to 15 years, observed for a 5.1 +/- 2.9 year period. The conditions of the diagnosis were: routine urinalysis in 10 cases, edema in eight, and the surveyance of a D-penicillamine treatment in two. All the patients had proteinuria (0.3 to 15 g/24 h) ranging to nephrotic syndrome in nine children. Microscopic hematuria was found in 16 children (80%). Elevated blood pressure was recorded in two cases at the time of diagnosis, and developed in two other cases during the follow-up. One child experienced renal failure at the onset of the disease. Most histological lesions consisted in stage II membranous glomerulonephritis. Immunofluorescence study (18 biopsies/20) always showed granulosus and intensive IgC deposits, associated with IgM and IgA deposits which were less marked; intensive extra-membranous C3 deposits were noted in 11 cases. As to the etiology, D-penicillamine was responsible for two cases (10%) and HBs antigen in one (5%); the nephropathy was considered as idiopathic in the 17 remaining cases (85%). Regarding the evolution: in eight cases (38%) proteinuria disappeared by 54 +/- 28 months; in 10 cases (55%), proteinuria persisted after 41 +/- 31 months; hematuria, which was present at onset, disappeared in most cases (13/17); in one case (5%), end-stage renal failure occurred within 3 years. The patient with initial renal failure has been last sight off.(ABSTRACT TRUNCATED AT 250 WORDS)