Role of transforming growth factor beta in peritoneal fibrosis

SUMMARY: Technique survival of peritoneal dialysis is seriously limited by the development of peritoneal fibrosis. the mesothelial cell layer lining the peritoneum is important in the pathogenesis of peritoneal fibrosis. Mesothelial cells are able to produce transforming growth factor beta (TGF-β), and respond to stimulation by this cytokine. In this review, we will detail the evidence available so far for the role of the complex interaction between TGF-β and mesothelial cells in the development of peritoneal fibrosis.     

A method for morphometric study of the intercostal muscles by high-resolution ultrasound

Besides their main function of assisting in breathing, the intercostal muscles also play an important role in maintaining the balance of forces acting on the thoracic cage including the thoracic spine. Since it is virtually impossible to conduct a morphometric evaluation of these muscles, a study was undertaken to standardize an ultrasound method for accurate determination of the area of the intercostal muscles and hence, indirectly, their function. In a pilot study, the area of the intercostal muscles was determined on the torso of a fresh specimen of a grown-up lamb, using high-resolution ultrasound and CT, and by direct measurements of the intercostal space at two points equidistant from the midline on the left and the right sides of the back of the specimen. The size of the intercostal muscles was determined either by tracing or from the perpendiculars of the area of the muscles both on sonographs and on CT scans. The results showed that measurements derived from the perpendiculars of the muscle area on the sonographs give better estimates than those derived from CT scans, and were in good accordance with the direct measurements of the corresponding intercostal space on the specimen. To evaluate the applicability of the method in vivo the area of the intercostal muscles at maximal inhalation and exhalation was determined in one adult person. It was found that measurements at maximal inhalation were more accurate than those taken at maximal exhalation. It is concluded that ultrasonography is a reliable, safe, easy to apply and high-resolution method for measurements of the area and, indirectly, of the activity of the intercostal muscles in humans, and that the measurements are more accurate at maximal inhalation. Received: 24 March 1997 Revised: 8 November 1997 Accepted: 27 November 1997     

Gamma interferon induction in human thymocytes activated by lectins and B cell lines.

Human thymocytes in culture synthesized small quantities of interferon (IFN) when stimulated by the lectins concanavalin A or phytohemagglutinin. IFN production by lectin-activated thymocytes was enhanced in the presence of live B lymphoblastoid cells, irradiated B lymphoblastoid cells, or the conditioned medium from B lymphoblastoid cell cultures. The IFN synthesized in mixed cultures had characteristics of IFN-gamma, whereas the IFN synthesized by B lymphoblastoid cells alone could be identified as IFN-alpha on the basis of its neutralization with specific antisera and stability at pH 2. These findings indicate that human thymocytes in culture synthesize IFN-gamma and that B lymphoblastoid cells and their products considerably stimulate IFN-gamma synthesis by lectin-activated human thymocytes in culture. This stimulation was not diminished in the presence of antibodies to IFN-alpha, indicating that IFN-alpha production by B lymphoblastoid cells was not responsible for the stimulatory effect. Removal of adherent cells from thymocyte suspensions did not abrogate IFN-gamma production.     

Human leukocyte antigen in genodermatosis

ABSTRACT: Tissue typing performed on the lymphocytes of 41 Patients, including: 23 patients with ichthyosis (15 of autosomal dominant and 8 of the x-linded variety; 8 patients with tuberous sclerosis (epiloia); and 10 patients with acroder-matitis enteropathica (AEP). In adddition, tissue typing was performed for a control group of 80 healthy unrelated subjects of the same ethnic origin as the patients. A significant increase of A₂ antigen or its crossreacting antigen A₂₈ was detected among the three diseases studied. A significant increase of HLA-A₂ antigen was found in autosomal dominant ichthyosis, while the x-linked variety showed significant association with HLA-Cw2. A significant association with HLA-A₂₈ antigen was noticed in both epiloia and AEP. The suggested mechanisms of such association may be refferred to as incidental genetic linkage with mutants causing disease or deficiency.     

Osteotomy does not improve early outcome after slipped capital femoral epiphysis

We performed a retrospective, nonrandomized cohort study of unilateral, chronic, severe, stable slipped capital femoral epiphysis comparing five girls and five boys who underwent in-situ screw fixation alone with five girls and five boys who underwent in-situ screw fixation combined with staged flexion intertrochanteric femoral osteotomy to restore proximal femoral alignment. Functional outcome was measured by the Harris hip score, with 20% selected as a goal for improvement in functional outcome after corrective osteotomy. While flexion intertrochanteric femoral osteotomy improved hip range of motion, we found no significant difference in functional outcome between the two groups at early follow-up. This is a level 3 evidence study.     

Anastomotic esophageal leak due to Taenia saginata following esophagectomy for esophageal cancer

A 50-year-old female with squamous cell carcinoma of the lower third of the esophagus underwent an esophagectomy via laparotomy and right thoracotomy. She developed a major anastomotic leak on the third postoperative day. The chest tube slipped out on the 10th postoperative day and a segment of Taenia saginata tapeworm came out through the tube drain site and was extracted. She was given praziquantel tablets treatment; after which the leakage dropped dramatically and ceased completely after one week. Patients scheduled for esophagectomy who experienced recurrent abdominal pain in areas endemic with a tapeworm need to be screened for taeniasis before surgery.     

Modulation of the expression of Tac antigen (T-cell growth factor response) on human thymocytes

This study shows that anti-Tac antibody does not bind to human thymocytes unless they are activated. Human thymocytes could be induced to express Tac antigen (TCGF receptor) on their cell surface by Concanavalin A. B lymphoblastoid cells or 12-O-tetradecanoylphorbol 13-acetate alone did not induce TCGF receptors, but they did exert a very marked synergistic effect with Concanavalin A. This observation is consistent with our earlier finding that B lymphoblastoid cells secrete a factor which exerts a synergistic effect on the induction of lymphokine secretion by thymocytes and T-cells. The early expression of Tac antigen was independent of thymocyte proliferation. Anti-Tac antibody (10(-3)) inhibited the expression of TCGF receptors and late proliferation of thymocytes. TCGF did not reverse this inhibition nor did it prevent the binding of Tac antibody, but it enhanced the expression of Tac antigen.