Response of jejunal phosphate absorption to 1,25-dihydroxyvitamin D(3) stimulationin vivo in young X-linked hypophosphatemic (Hyp) mice.

YoungHyp mice malabsorb phosphate from the jejunum at 4 weeks of age. This has been attributed to both low plasma levels of 1,25-dihydroxyvitamin D and to intestinal resistance to stimulation by 1,25-dihydroxyvitamin D. To differentiate between these two hypotheses, 4 week old normal andHyp mice were treated with 0, 17, 50, or 150 ng/kg/day of 1,25-dihydroxyvitamin D(3) by Alzet osmotic mini pumps (n=10-12/group). After 4 days, the jejunum was isolated by sutures and 0.5 ml 2 mM Na(2)HPO(4) in 150MM: NaCl with 1.0 µCi(32)PO(4) was injected into the lumen. After 8 min, plasma, jejunal tissue and lumenai contents were measured for(32)P content. Absorption was measured as counts removed from the lumen. Both normal andHyp mice responded to the 1,25-dihydroxyvitamin D(3) with increased absorption, increased tissue(32)P and increased plasma(32)P.Hyp mice responded less than normal mice to the 50 ng/kg/day dose in plasma(32)P levels (significant dose by genotype interaction,P<0.05). Plasma was pooled by genotype and dose for the measurement of plasma 1,25-dihydroxyvitamin D. This yielded 13 samples (7 normal and 6Hyp). Absorption of(32)P (r=0.75, p=0.002) and jejunal tissue content of(32)P (r=0.66, p=0.02) were correlated to plasma 1,25-dihydroxyvitamin D. Analysis of covariance revealed a significant difference in phosphate absorption between normal andHyp mice (p=0.02). In conclusion, there is a partial resistance of intestinal phosphate absorption to 1,25-dihydroxyvitamin D stimulation.

Training opinion leaders to promote safer sex.

Training opinion leaders in a men's residence hall in a brief program focused on communication and life skills is an effective way to stimulate peer discussions on HIV prevention and risk reduction and appears likely to have positive influences on behavioral change or intention. The program at the University of Wisconsin-Madison was extremely cost-effective and generated more than 350 conversations in a single residence hall in 1 month. This limited intervention revealed several key indicators of risk reduction. We believe that larger, more refined programs over a longer period will produce sustained prevention benefits and changes in the peer norms that so strongly influence behavior.

Malabsorption of phosphate by the intestines of young X-linked hypophosphatemic mice.

X-linked hypophosphatemic (Hyp) mice are a model for human X-linked (familial) hypophosphatemia (vitamin D-resistant rickets). In several studies, Hyp mice have been shown to exhibit either normal intestinal phosphate absorption or malabsorption of phosphate. These apparently conflicting reports led us to further investigate intestinal phosphate absorption. Isolated intestinal segments in vivo were used in C57BL/6J normal and Hyp mice, both male and female. 33P was placed in the segment in 2 mM Na2HPO4 + 150 mM NaCl, pH 7.2. Mice at 4, 7, and 12 weeks of age were used. No significant differences in phosphate absorption were found between the sexes. At 4 weeks of age, Hyp mice showed significant malabsorption of phosphate, with the jejunum being the most severely affected. Malabsorption was judged by significantly more 33P remaining in the lumen, less in the intestinal tissue, and less in the plasma. At 7 weeks of age, these same trends were seen but at a nonsignificant level. By the 12th week of life, the absorption of 33P was similar in Hyp and normal mice. Thus, phosphate malabsorption in Hyp mice is an age-related phenomena. These changes parallel the malabsorption of calcium in young Hyp mice and reflect the lowered plasma 1,25-dihydroxyvitamin D (1,25(OH)2D) levels of young Hyp mice.

Mineral uptake by the femora of older female X-linked hypophosphatemic (HYP) mice but not older male HYP mice.

X-linked hypophosphatemic (Hyp) mice are a model of human sex-linked vitamin D-resistant rickets. Young adult Hyp mice are characterized by osteomalacia and decreased bone mineral content. However, older heterozygous Hyp female mice increase in bone mineral content with age so that by one year of age the bone mass/mm femoral length equals or exceeds normal females. To test for the occurrence of this mineral accretion in Hyp male mice and in homozygous Hyp female mice, femora from all 3 Hyp genotypes as well as normal male and female mice were analyzed at various ages from one to 52 weeks of age. Compared to normal mice, all three Hyp genotypes were depressed in bone ash, femoral length, and ash/length ratio at 13 weeks of age. After that age the femora of both heterozygous and homozygous Hyp females showed a slow mineral accretion and, by 52 weeks of age, a normal ash/length ratio. However, the femora of Hyp males, as well as those of normal males, failed to increase in bone mineral content or ash/length ratio after 13 weeks of age. The differences between male and female Hyp mice could not be explained by differences in the plasma levels of calcium, phosphate, or alkaline phosphatase. Increased bone mineral content in older Hyp mice was seen in both heterozygous and homozygous females but not in hemizygous males. Thus, the basis for this increase is not incomplete dominance of the Hyp gene in females nor the Lyon hypothesis. The accretion of mineral in older female Hyp mice despite lifelong reduced plasma phosphate levels suggests that there are factors other than phosphate that also regulate mineral accretion in this bone disease.

[Value of the Chiba needle in the technique of percutaneous transhepatic cholangiography. 20 cases. (author's transl)]. / Apport de l'aiguille de Chiba dans la technique de la cholangiographie trashépatique percutanée.

The authors used the Chiba needle for percutaneous trasphepatic cholangiography in 20 patients. Catheterisation of non-dilated biliary canals is easy with this new piece of equipment, making it possible to confirm or eliminate the presence of an obstruction. There were no severe complications. The authors report a certain number of incidents which were troublesome during the examination and in the interpretation of the results: intraparenchymatous injection, sub-capsular injection, defective filling.

[Radiological exploration of the Budd-Chiari syndrome. Study of 13 cases]. / Exploration radiologique du syndrom de Budd-Chiari. Etude de 13 cas

Using 13 cases of Budd-Chiari syndrome, the authors describe their method of radiological investigation in order to reach a positive and sometimes aetiological diagnosis. Hepatic venous thrombosis can be confirmed only on the basis of findings at hepatic phlebography. Cavography, which precedes retrograde catheterisation of the hepatic veins, provides only presumptive evidence and sometimes reveals total thrombosis of the inferior vena cava. Coeliac and superior mesenteric, or even hyperselective hepatic arteriography, is of great value if there is inversion of the portal flow. Otherwise it only leads to a suspicion of the diagnosis, and makes it possible to determine the state of the portal trunk and to seek an aetiology.

[A rare cause of spontaneous haemoperitoneum: rupture of an aneurysm due to fibromuscular dysplasis (author's transl)]. / Une cause rare d'hémopéritoine spontané : la rupture d'un anévrysme d'une dysplasie fibro-musculaire

The authors report the case of a patient presenting with an acute haemoperitoneum. Angiography after surgery led to a diagnosis of fibro-muscular dysplasia. They stress the rarity of this aetiology in the development of haemoperitoneum, perhaps related to the small number of angiographic studies made after surgery.

[Arterial embolization in the treatment of metrorrhagia of tumoral origin]. / L'embolisation artérielle dans le traitement des métrorragies d'origine tumorale

The authors report two cases of embolisation of the genital arteries in patients suffering from emtrorrhagia due to a tumour and in whom surgical treatment was impossible. The results of embolisation were satisfactory.