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.     

Variability of ankle and brachial systolic pressures in the measurement of atherosclerotic peripheral arterial disease.

The aim of this study was to determine the variability of measurements of ankle and brachial systolic pressures and ankle brachial ratios in order to assess their suitability for use in epidemiological studies of arterial disease in the lower limbs. Thirty-six subjects had repeat measurements taken by four observers on two separate days using a Doppler probe and random zero sphygmomanometer. The variability in the measurement of ankle systolic pressure was comparable to that for brachial systolic pressure. The 95% confidence limits of one measurement of the ankle brachial ratio was estimated to be +/- 16%, reducing to +/- 10% for the mean of four measurements taken by two observers on two days. Analysis of variance indicated that the variability in the measurement of ankle brachial ratios attributable to observers, days, timing of measurements on the same day, and repeat measurements was considerably less than the "biological" variability between subjects and between legs. These results suggest that repeatability of the ankle brachial ratio is such that a single measurement is suitable for most epidemiological studies of atherosclerotic peripheral arterial disease.     

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.      

Application of molecular biology techniques to malignant haematology]

Malignant hemopathies, although heterogeneous in their prognosis and oncogenesis, represent an interesting model for studying cancer genesis mechanisms in man through the recurrent presence of genetic abnormalities involved in oncogenesis and the availability of tumour material. Nowadays, molecular biology techniques are very much used for the diagnosis, the treatment and the follow-up of these diseases. Firstly used for research, the new techniques have completely changed our ability to characterise malignant hemopathies and to understand the cancer-inducing processes, permitting us to perform the biological assessment of patients with malignant hemopathies, the diagnosis, and to estimate and follow the outcome of patients after treatment. At a more fundamental level, the structural and functional analysis of the deregulated genes implied in leukaemia and lymphoma has improved our knowledge and understanding of oncogenic and physiologic mechanisms significantly.     

The Effects of IB4, a Monoclonal Antibody to the CD18 Leukocyte Integrin on Phorbol Myristate Acetate (PMA)-Induced Polymorphonuclear Leukocyte (PMN) Accumulation and Endothelial Injury in Rabbit Lungs

A model of acute lung injury induced by intravenous phorbol myristate acetate (PMA) is described. The model is characterized by the accumulation of polymorphonuclear leukocytes (PMNs) and a hemorrhagic edema in bronchoalveolar lavage (BAL) fluid when measured 6 h following the administration of PMA (60 g/kg, i.v.). It was also determined that PMA induces acute leukopenia and neutropenia which were maximal at 5 min following the injection of PMA and were sustained for at least 6 h, with circulating leukocyte numbers returning to control values by 24 h. The extents to which the inflammatory and systemic changes induced by PMA were dependent on the surface expression on leukocytes of the 2-integrins was assessed by comparing responses to PMA in control animals and animals pretreated with the anti-CD18 monoclonal antibody IB4. The administration of IB4 (1 mg/kg, i.v.) 15 min before PMA did not alter the time course or extent of PMA-induced leukopenia and neutropenia. In contrast IB4 administration (0.1 to 1 mg/kg) produced a dose dependent inhibition of PMN accumulation and plasma extravasation measured in BAL fluid. IB4 (1 mg/kg) completely inhibited PMA evoked increases in plasma extravasation (94.5 ± 1.7%, N = 4) and hemorrhage (95.2 ± 2.1%, N = 4) whereas PMN accumulation in BAL fluid was inhibited by 77.8 ± 3.8% (mean ± SEM, N = 4). Thus, a small, but reproducible, component of the PMA-induced PMN accumulation was not inhibited using this regimen of IB4 administration. If IB4 administration was delayed for 3 h post injection of PMA and bronchoalveolar lavage performed 3 h later, the extents of PMN accumulation and edema formation were similar to those observed 3 h following PMA challenge in control animals not dosed with IB4. This suggests that administration of IB4 during an ongoing inflammatory response is capable of preventing the further development of inflammatory changes and further supports the therapeutic potential of CD18 blockade in conditions such as adult respiratory distress syndrome.     

Do women 'over-report' morbidity? Men's and women's responses to structured prompting on a standard question on long standing illness

It is frequently observed in contemporary industrialised societies that although women live longer than men, they are sicker than men in that they report higher rates of morbidity, disability and health care use. One common element of the explanation for women's higher rates of morbidity is that there are gender differences in the way that symptoms are perceived, evaluated and acted upon. It is widely assumed that women will be more ready to report illness and to seek help and that they have greater flexibility in their lives to accommodate illness. The few studies that have examined men and women with the same conditions or symptoms are contradictory, but lend little support to this hypothesised greater propensity, yet it is still widely believed. Here we compare men's and women's answers to a global, commonly used question about chronic illness and to a series of more specific prompts and classify the conditions reported by an externally defined categorisation of severity and International Classification of Disease chapter. Contrary to the common expectation that women report higher rates of morbidity and are more ready to report mental health problems, we found: no gender differences in the initial reporting of conditions; men reported a higher proportion of their conditions in response to the initial global question; and no evidence that women were more likely to report 'trivial' or mental health conditions in response to the initial question.