Release of soluble transferrin receptor from the surface of human leukemic HL60 cells

Information regarding transferrin (Tf) receptor degradation is largely incomplete. HL60 cells were shown to release to their growth medium a Tf-binding protein which could be immunoprecipitated by anti-Tf receptor monoclonal antibodies (MoAbs) B3/25 and OKT9. Soluble Tf receptor was detected in the medium within one hour of replating of cells, and its release was inhibited at 4 degrees C. The affinity of Tf for the soluble receptor released by cells (kd = 2.3 x 10(-10) mol/L) was slightly lower than its affinity for the detergent-solubilized cellular receptor (kd = 1.2 x 10(-10) mol/L). 125I-Tf internalized and released by cells subsequently bound to Tf receptor released by the same cells, and soluble Tf receptor in the conditioned medium (CM) inhibited 125I-Tf binding to intact cells. The soluble Tf receptor isolated from the CM was smaller (78,000 daltons) than the cell surface receptor (94,000 daltons) when analyzed by gel electrophoresis under reducing conditions. Isolated cell membranes readily released soluble receptor; however, this release could be blocked by protease inhibitors. The soluble Tf receptor may represent the extracytoplasmic domain of the cellular Tf receptor released from the surface of HL60 cells through proteolytic cleavage by a membrane-based protease.     

Localization of a gene for otosclerosis to chromosome 15q25-q26

Among white adults otosclerosis is the single most common cause of hearing impairment. Although the genetics of this disease are controversial, the majority of studies indicate autosomal dominant inheritance with reduced penetrance. We studied a large multi- generational family in which otosclerosis has been inherited in an autosomal dominant pattern. Five of16 affected persons have surgically confirmed otosclerosis; the remaining nine have a conductive hearing loss but have not undergone corrective surgery. To locate the disease- causing gene we completed genetic linkage analysis using short tandem repeat polymorphisms (STRPs) distributed over the entire genome. Multipoint linkage analysis showed that only one genomic region, on chromosome 15q, generated a lod score >2.0. Additional STRPs were typed in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis gene.      

Peritoneal fluid concentrations of interleukin-8 in women with endometriosis: relationship to stage of disease

There is increasing evidence that immunological mechanisms play a role in the pathogenesis and pathophysiology of endometriosis. It was therefore of interest to study interleukin-8 (IL-8), a chemokine, in the peritoneal fluid and peripheral blood of women undergoing laparoscopic procedures. The presence and concentrations of IL-8 in relation to endometriosis, infertility and abdominal pain were evaluated. Samples of peritoneal fluid (n = 49) and peripheral blood (n = 50) were obtained from 50 consecutive patients undergoing laparoscopic surgery for various gynaecological indications (abdominal pain, infertility, sterilization). IL-8 was present in the peritoneal fluid of most women (87%). The concentration of IL-8 in the peritoneal fluid was higher in women with endometriosis compared to women without (P = 0.02). This difference was more pronounced in early (stage 1) endometriosis (P = 0.001). IL-8 concentrations in the peritoneal fluid were also higher in women with early endometriosis compared to women with later stages of the disease (P = 0.003). Peripheral blood concentrations did not correlate with peritoneal fluid concentrations of IL-8 and/or the presence of endometriosis. We conclude that IL-8 is an important factor that may contribute to the pathogenesis of endometriosis possibly by promoting neovascularization. This information can be a guide in the development of new therapeutic approaches for the treatment of endometriosis.      

慢性硬膜下血肿168例的诊治和预后

0　引言　 1 992 - 0 5～ 1 999- 0 5我科收治慢性硬膜下血肿 (CS-DH) 1 6 8例 ,其中 1 6 4例经颅骨钻孔冲洗引流术治疗 ,4例保守治疗 ,结果 1 6 5例治愈 ,3例死亡 .结论 :CSDH的诊断主要依靠 CT检查 ,手术简单 ,防止并发症可改善预后 .1　临床资料　男 1 6 3例 ,女 5例 ,年龄 32～ 79岁 ,平均 5 4岁 .有明确的外伤史 1 4 5例 (86 .3% ) ,原因不明 2 3例(1 3.7% ) ,病程 3wk～ 6 a.头昏、头痛、呕吐 1 1 6例 ,肢体运动障碍 6 8例 ,智力及精神障碍 46例 ,语言障碍 1 0例 ,感觉障碍2 1例 ,排尿障碍 5例 ,癫痫 3例 ,视乳头水肿 92例 ,锥体…     

5,10-methylenetetrahydrofolate reductase common mutations, folate status and plasma homocysteine in healthy French adults of the Supplementation en Vitamines et Mineraux Antioxydants (SU.VI.MAX) cohort

The 677cytosine mutation identified in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene has been frequently associated with an elevated plasma homocysteine concentration. The aim of the present study was to determine the impact of this MTHFR common mutation on plasma and erythrocyte folate (RCF) and plasma total homocysteine (tHcy) concentrations in healthy French adults. A cohort of 291 subjects living in the Paris area and participating in the Supplementation en Vitamines et Mineraux Antioxydants (SU.VI.MAX) study were analysed to assess the impact of MTHFR polymorphism 677C-->T on folate status and plasma tHcy concentration. The frequency of the mutant homozygote for 677C-->T polymorphism (677TT genotype) in the present cohort was 16.8%. There were significant differences in plasma tHcy between 677CC, 677CT and 677TT genotype groups. The RCF concentrations were significantly different between each genotype, the lowest levels being associated with the 677TT genotype. When segregated by gender, no differences in tHcy between homozygous 677TT, heterozygous 677CT and wild-type 677CC genotype groups in women were observed. The fasting tHcy in women was unrelated to the 677C-->T mutation. However, tHcy was significantly increased in men with the homozygous 677TT genotype. We also analysed the possible implication of a second new MTHFR polymorphism (1298A-->C) in subjects with mild hyperhomocysteinaemia (4th quartile of homocysteinaemia; tHcy >11.1 micromol/l). The polymorphism 1298A-->C did not have a notable effect on tHcy or on the RCF levels. Our observations confirm a relatively high frequency of the 677TT genotype in the French population. Women with this genotype did not show the same increase in tHcy observed in men. In the present study dietary folate intake was not measured. Thus, the interaction of dietary folate with the MTHFR genotype in the French population needs further study.