Platelet-osteosarcoma cell interaction is mediated through a specific fibrinogen-binding sequence located within the N-terminal domain of thrombospondin 1.

Approximately 20% of patients with osteosarcoma have metastatic disease in lungs or bones at diagnosis. The requirement of platelets in hematogenous dissemination of metastatic cells is now well established. Tumor cells interact with platelets and induce platelet aggregation. In this respect, metastatic potential of tumor cells correlates with their capacity to aggregate platelets in vitro. We have previously shown that thrombospondin 1 (TSP-1) is synthesized and expressed on the surface of MG-63 osteosarcoma cells and mediates platelet-osteosarcoma cell interaction. However, active sites mimicking the function of TSP-1 during platelet-osteosarcoma cell interaction are not known. In this study, a panel of antibodies directed against the N-terminal and C-terminal domains and type 1, type 2, and type 3 repeats of TSP-1 were first used to delineate the structural requirement for the binding of osteosarcoma cell surface-associated TSP-1 to platelets. A drastic inhibition of the platelet-aggregating activity of MG-63 cells was obtained in the presence of a monoclonal antibody directed against the N-terminal domain of TSP-1. Among a series of 16 synthetic peptides spanning the whole N-terminal domain of TSP-1, only synthetic peptide N12/I encompassing amino acid residues 151-164 of the N-terminal domain of TSP-1 inhibited the platelet-aggregating activity of MG-63 cells. Electron microscopy studies showed that peptide N12/I strongly inhibited platelet-osteosarcoma cell interaction. A polyclonal antibody directed against peptide N12/I specifically bound to the surface of MG-63 cells, recognized TSP-1 and drastically inhibited the platelet-aggregating activity of MG-63 cells. In addition, peptide N12/I specifically bound to fibrinogen and inhibited TSP-1/fibrinogen interaction. Overall, our results provide evidence that a fibrinogen-binding sequence located within the N-terminal domain of TSP-1 mediates the binding of osteosarcoma cell surface-associated TSP-1 to platelet-bound fibrinogen.     

Concurrent cisplatin/etoposide plus 3D-conformal radiotherapy followed by surgery for stage IIB (superior sulcus T3N0)/III non-small cell lung cancer yields a high rate of pathological complete response

Introduction: Optimal preoperative treatment of stage IIB (Pancoast)/III non-small cell lung cancer (NSCLC) remains undetermined and a subject of controversy. The goal of our study is to confirm feasibility and pathological response rates after induction chemoradiation (CRT) in our community-based treatment center. Patients and methods: Patients were selected according to functional and resectability criteria. Induction treatment comprised 3D conformal 4500 cGy radiotherapy delivered to the primary tumor and pathologic hilar and/or mediastinal lymph nodes on CT scan with an extra-margin of 1–1.5 cm. Concurrent chemotherapy regimen was cisplatinum 20 mg/m² d1–d5 and etoposide 50 mg/m² d1–d5, d1–5 d29–33. Within 3–4 weeks after CRT completion, operability was re-assessed accordingly. Surgery was performed 4–6 weeks after CRT completion in patients (pts) deemed resectable. Inoperable pts were referred for a 20–25 Gy boost ±1 extra-cycle of cisplatinum + etoposide. Results: From 1996 to 2005, 107 pts were initially selected for treatment and received induction chemoradiation (stage IIB-Pancoast 18, IIIA 58 and IIIB 31, squamous cell carcinoma 48%, adenocarcinoma 44%, large-cell undifferentiated carcinoma 14%). After preoperative evaluation, 72 pts (67%) had a thoracotomy (pneumonectomy 21, lobectomy 45, bilobectomy 5) and all but one (unresectable tumor) had a macroscopic complete resection. During the 3-month postoperative time, five patients (6.9%) died, four after pneumonectomy (right 3, left 1). The analysis of tumoral samples showed a pathological complete response rate or microscopic residual foci of 39.5%. Median follow-up time was 22.3 months (survivors: 36.8 months), 2-year and 3-year overall survival rates were 55% and 40%, respectively (median = 26.7 months) for all the intention-to-treat population (n = 107), 62% and 51% (median = 36.5 months) for 71 resected pts, 41% and 16% for 36 non-resected pts (median = 19.1 months). On multivariate analysis, surgical resection and tumoral necrosis >50% (or pathological complete response) were the most pertinent predictive factors of the risk of death (hazard ratio = 0.50 and 0.48, p = 0.006 and 0.038, respectively). Conclusion: Surgery was feasible after induction chemoradiation, particularly lobectomy in PS 0–1, stage IIB (Pancoast)/III NSCLC pts but pneumonectomy carries a high risk of postoperative death (particularly, right pneumonectomy). Pathological response to induction chemoradiation was complete in 39.5% of patients and was a significant predictive factor of overall survival.     

Evaluation of C4d Deposition and Circulating Antibody in Small Bowel Transplantation

Antibody-mediated rejection (AMR) consensus criteria are defined in kidney and heart transplantation by histological changes, circulating donor-specific antibody (DSA), and C4d deposition in affected tissue. AMR consensus criteria are not yet identified in small bowel transplantation (SBTx). We investigated those three criteria in 12 children undergoing SBTx, including one retransplantation and four combined liver-SBTx (SBTx), with a follow-up of 12 days to 2 years. All biopsies (91) were evaluated with a standardized grading scheme for acute rejection (AR), vascular lesions and C4d expression. Sera were obtained at day 0 and during the follow-up. C4d was expressed in 37% of biopsies with or without AR, but in 50% of biopsies with severe vascular lesions. In addition, vascular lesions were always associated with AR and a poor outcome. All children with AR (grade 2 or 3) observed before the third month died or lost the graft. DSA were never found in any studied sera. We found no evidence that C4d deposition was of any clinical relevance to the outcome of SBTx. However, the grading of vascular lesions may constitute a useful marker to identify AR that is potentially resistant to standard treatment, and for which an alternative therapy should be considered.     

Prognostic value of homocysteinemia in patients with congestive heart failure.

BACKGROUND: Elevated plasma homocysteine levels are associated with increased risk of vascular disease and of congestive heart failure (CHF), with a relationship between homocysteine values and disease severity. Hyperhomocysteinemia is a risk factor for cardiac dysfunction. In this study, the predictive value of elevated homocysteine levels was investigated in the prognosis of ischemic and non-ischemic CHF. METHODS: A total of 159 patients with CHF, 89 with non-ischemic and 70 with ischemic CHF (83% males, mean age 62 years, mean ejection fraction 27%), and 119 controls (79% males, mean age 59.8 years) had fasting blood samples taken to measure plasma homocysteine, vitamin B(12) and folate levels. Coronary angiography was performed for all patients. The mean duration of follow-up was 49.6+/-36.7 months. RESULTS: As in other studies, the mean level of homocysteinemia was significantly higher in the CHF group (15.80 micromol/L) than in the control group (10.90 micromol/L) (p=0.001) whatever the etiology (non-ischemic, 16.11+/-6.84 micromol/L; ischemic, 15.41+/-6.45 micromol/L). This result was observed without vitamin deficiency, but in patients, the mean creatinine value was moderately higher than in controls. We found a positive correlation between plasma homocysteine levels and New York Heart Association (NYHA) classification, creatinine and age. Moreover, hyperhomocysteinemia appears to be a powerful predictive factor of mortality in CHF patients (relative risk of death, 4.23; p=0.0003). In the follow-up of this study, 41.5% of patients with homocysteinemia >17 micromol/L died vs. 21.3% of patients with levels <17 micromol/L. In multivariate analysis, when homocysteine levels were adjusted for a second parameter (age, NYHA, creatinine, diabetes), the risk of death remained significant after each adjustment. CONCLUSIONS: Elevated homocysteine levels observed in CHF patients, whatever the etiology of their heart disease (ischemic or non-ischemic), were correlated with the severity of the disease. Hyperhomocysteinemia appears to be a predictive factor of mortality in CHF patients.     

The antiperinuclear factor and the so-called antikeratin antibodies are the same rheumatoid arthritis-specific autoantibodies.

The so-called antikeratin antibodies (AKA) and the antiperinuclear factor (APF) are the most specific serological markers of RA. Using indirect immunofluorescence, AKA label the stratum corneum of various cornified epithelia and APF the keratohyalin granules of human buccal mucosa epithelium. We recently demonstrated that AKA recognize human epidermal filaggrin. Here, we report the identification of the major APF antigen as a diffuse protein band of 200-400 kD. This protein is seen to be closely related to human epidermal (pro) filaggrin since it was recognized by four antifilaggrin mAbs specific for different epitopes, and since the APF titers of RA sera were found to be correlated to their AKA titers and to their immunoblotting reactivities to filaggrin. Immunoabsorption of RA sera on purified epidermal filaggrin abolished their reactivities to the granules of buccal epithelial cells and to the 200-400-kD antigen. Moreover, antifilaggrin autoantibodies, i.e., AKA, affinity purified from RA sera, were shown to immunodetect the 200-400-kD antigen and to stain these granules. These results indicate that AKA and APF are largely the same autoantibodies. They recognize human epidermal filaggrin and (pro) filaggrin-related proteins of buccal epithelial cells. Identification of the epitopes recognized by these autoantibodies, which we propose to name antifilaggrin autoantibodies, will certainly open new paths of research into the pathophysiology of RA.     

Functional consequences of a neutral pH in neonatal rat stratum corneum

At birth, neonatal stratum corneum (SC) pH is close to neutral but acidifies with maturation, which can be ascribed, in part, to secretory phospholipase A(2) and sodium/hydrogen antiporter 1 (NHE1) activities. Here we assessed the functional consequences of a neutral SC pH in a newborn rat model. While basal transepidermal water loss rates are near normal, barrier recovery (BR) rates after acute barrier disruption were delayed in newborn animals. The abnormality in barrier homeostasis could be improved by topical applications of an acidic buffer, indicating that barrier abnormality is primarily due to high SC pH. The delay in BR correlated with incompletely processed lamellar membranes and decreased activity of beta-glucocerebrosidase. Inhibition of NHE1 delayed BR after acute barrier perturbation. SC integrity was abnormal in newborn animals. Electron microscopy demonstrated decreased corneodesmosomes (CD) in newborn animals with decreased expression of desmoglein 1 and corneodesmosin. Serine protease activation appears to be responsible for CD degradation in newborn animals, because serine protease activity is increased in the SC and it can be reduced by acidification of the SC. The delay in acidification of neonatal SC results in abnormalities in permeability barrier homeostasis and SC integrity and are likely due to pH-induced modulations in enzyme activity.     

Soluble flagellin, FliC, induces an Ag-specific Th2 response, yet promotes T-bet-regulated Th1 clearance of Salmonella typhimurium infection

Clearance of disseminated Salmonella infection requires bacterial-specific Th1 cells and IFN-γ production, and Th1-promoting vaccines are likely to help control these infections. Consequently, vaccine design has focused on developing Th1-polarizing adjuvants or Ag that naturally induce Th1 responses. In this study, we show that, in mice, immunization with soluble, recombinant FliC protein flagellin (sFliC) induces Th2 responses as evidenced by Ag-specific GATA-3, IL-4 mRNA, and protein induction in CD62L(lo) CD4(+) T cells without associated IFN-γ production. Despite these Th2 features, sFliC immunization can enhance the development of protective Th1 immunity during subsequent Salmonella infection in an Ab-independent, T-cell-dependent manner. Salmonella infection in sFliC-immunized mice resulted in augmented Th1 responses, with greater bacterial clearance and increased numbers of IFN-γ-producing CD4(+) T cells, despite the early induction of Th2 features to sFliC. The augmented Th1 immunity after sFliC immunization was regulated by T-bet although T-bet is dispensable for primary responses to sFliC. These findings show that there can be flexibility in T-cell responses to some subunit vaccines. These vaccines may induce Th2-type immunity during primary immunization yet promote Th1-dependent responses during later infection. This suggests that designing Th1-inducing subunit vaccines may not always be necessary since this can occur naturally during subsequent infection.     

Immunohistochemical identification of reserve cells of the endocervical canal by monoclonal antibodies EE21-06d

All-Union Oncologic Scientific Center, Moscow. Kazan' Medical Institute, USSR. Departments of Cell Biology and Histology, Toulouse-Purpan School of Medicine, Toulouse, France. (Presented by Academician of the Academy of Medical Sciences of the USSR D. S. Sarkisov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 11, pp. 603–606, November, 1989.