Analysis of proteins synthesized by fibroblasts from patients with cystic fibrosis by two-dimensional gel electrophoresis and double label autoradiography

Mucoviscidosis, the most frequently lethal genetic syndrome of Caucasian population, is a recessive disease with multiple tissue involvement. Although the major pathological changes are observed in lungs and pancreas, abnormalities have also been detected in several other exocrine glands. For many reasons, such as the ready availability of tissue material, the absence of secondary changes and the potential for prenatal diagnosis, cultured skin fibroblasts could be the tissue of choice to search for the primary defect. Several abnormalities have been reported in CF fibroblasts, suggesting that the genetic abnormality is expressed in these cells. To search for potentially mutant protein(s) we have compared the protein composition of normal and CF fibroblasts by two dimensional gel electrophoresis and double-labeling autoradiography using 35S and 75Se methionine as tracer. The results demonstrate the power of the method; however, we have not found one protein spot consistently missing in CF cells. Possible reasons for the absence of a single common identifiable defect are discussed.     

Role of G(s) proteins in hypoxic constriction of sheep pulmonary artery rings

The introduction of hypoxia is well known to cause contraction of pulmonary artery rings in vitro. Despite intensive studies, the cellular mechanisms of hypoxic pulmonary vasoconstriction are still not well defined. In this study, we aimed to determine the contribution of G(S) proteins in hypoxia-induced vasoconstriction in large-diameter sheep pulmonary arteries using cholera toxin (CT). Hypoxia caused further contractions in serotonin but not in NaF-precontracted pulmonary artery rings. However, hypoxic vasoconstriction due to lowering of pO(2) from 97 to 5 mm Hg was totally abolished by preincubation with CT in serotonin-precontracted arteries. These preliminary results indicate that signal transduction mediated by G(s) proteins may be an important mechanism in the hypoxic vasoconstriction of isolated pulmonary arteries of sheep.     

Pleural flap for treating perigraft leak after a modified Blalock-Taussig shunt

Plasa oozing through the graft after a modified Blalock-Taussig shunt is a troublesome complication. We encountered a massive leak following a modified Blalock-Taussig shunt in a 2 1/2 year-old-girl which required reexploration. The leak was treated by wrapping the polytetrafluoroethylene shunt with the parietal pleura flap harvested from the adjacent chest wall. The patient had an uneventful recovery. Covering of the polytetrafluoroethylene shunt with parietal pleura appears to stop plasma leak through the graft following a modified Blalock-Taussig shunt.     

Immunophenotypic changes and induction of apoptosis of monocytes and tumour cells during their interactions in vitro

The in vitro model of tumour infiltrating macrophages (TIM)-tumour interactions in which monocytes and monocyte-derived macrophages (MDM) are cultured with cancer cells was used to assess immunophenotypic changes of interacting cells. Following short cocultures, monocytes, MDM and tumour cells were sorted out by FACS and the expression of several determinants was evaluated. Monocytes showed the induction of CD44v6 and v7/8, and up-regulation of CD16 (Fc gamma RIII), CD54 (ICAM-1), CD68 (macrophage maturation marker) and CD86 (costimulatory molecule B7.2). The increased expression of CD11a (LFA-1) and CD58 (LFA-3) was noted on some cancer cells. Up-regulation of TNFRII and HLA-DR was observed on both types of cells. MDM shared similar changes. Contact of monocytes, but not of MDM, with tumour cells led to Fas-FasL-dependent apoptosis of both types of cells. This study suggests that the immunophenotype of monocytes/macrophages and cancer cells may be modified during their bidirectional interactions in the absence of other microenvironmental elements that are present in the tumour stroma.     

Neoadjuvant chemotherapy with taxotere-epirubicin-5-fluorouracil (TEF) in local-regionally advanced breast cancer: a preliminary report

AIMS AND BACKGROUND: Sixty-three patients with local-regionally advanced breast cancer were treated with neoadjuvant chemotherapy consisting of docetaxel (Taxotere), epirubicin, and 5-fluorouracil (TEF). METHODS AND STUDY DESIGN: Preoperatively, patients received four cycles of Taxotere (80 mg/m2), epirubicin (60 mg/m2), and 5-fluorouracil (500 mg/m2), repeated every 21 days. Following completion of four cycles of chemotherapy, appropriate surgery was performed. After the surgery, patients received one cycle of the TEF chemotherapy regimen; following chemotherapy, radiotherapy was applied, and at the end two more cycles of TEF chemotherapy regimen were given. RESULTS: Sixty-three patients with locally advanced breast cancer were treated. Three patients were excluded from the study before the evaluation of response. Median age of the patients was 50 years (range, 25-77). Twenty-seven and 33 patients were premenopausal and postmenopausal, respectively. Thirty-nine patients were in stage IIIA and 21 in stage IIIB. Complete and partial responses were observed in 15 (25%) and 42 (70%) of the patients following four cycles of preoperative TEF chemotherapy regimen, respectively. Overall response was 95%, and primary lesion progressed only in 3 (5%) patients. The mean disease-free survival was 15.9 +/- 6.8 (range, 3.5-28) months and the mean overall survival was 18.6 +/- 7.2 (range, 5-30) months. The most frequent side effects were nausea-vomiting, mucositis, alopecia and leukopenia. CONCLUSIONS: TEF therapy is a treatment with a high overall response rate and toxicities similar to other taxotere combinations. A longer follow-up of patients is necessary for the determination of disease-free survival and overall survival.     

Limited genetic diversity of Candida albicans in fecal flora of healthy volunteers and inpatients: a proposed basis for strain homogeneity in clinical isolates

Molecular analysis of Candida albicans isolates from individual patients often yields a single strain at multiple sites. Whether this strain-limitation is due to virulence factors favoring the invasive strain or to lack of genetic diversity in the gastrointestinal reservoir is uncertain. We elected to study C. albicans genotypes in the fecal flora among healthy volunteers and inpatients. Self-obtained stool swabs or stool samples were cultured on inhibitory mold agar. From each subject with C. albicans, nine colonies were randomly selected, individually propagated, and typed utilizing random amplified polymorphic DNA. Colonies were considered identical (all bands matched), related variants (one to three unique bands), or distinct strains (more than three unique bands). Analysis showed a single clone in 33/43 (76.7%) volunteers and 6/18 (33.3%) inpatients (P = 0.018), two to four related variants in eight (18.6%) volunteers and 10 (55.6%) inpatients, and two distinct strains in two volunteers (4.6%) and two inpatients (11.1%). Strain variation was more common in females (33.5 versus 5.6%; P = 0.04) and tended to increase with age (r = 0.245, P = 0.06). These findings illustrate that most healthy subjects harbor a single strain of C. albicans in the fecal flora. This strain may undergo genetic evolution leading to minor clonal variations. The mechanisms for strain selection, maintenance and possible evolution remain to be delineated.