Relationship of HLA to schizophrenia not supported in multiplex families.

The role of the human histocompatibility complex (HLA) in the pathogenesis of schizophrenia has been suggested in previous reports. We conducted a genetic study in 33 new families. Our linkage analysis, which used the affected sib-pair method, did not provide evidence for nonrandom assortment. Moreover, the results of an association study using the "haplotype relative risk" method failed to confirm the positive association between HLA A9 and schizophrenia. Taken together, our data did not support any relationship of HLA type to schizophrenia.     

Production of multiple murine CD2 receptor constructs using the baculovirus expression vector and a rapid dot-blot assay

The baculovirus expression system was used to produce three different constructs of the murine cell surface adhesion receptor CD2. One construct coded for a single, N-terminal, Ig-fold domain. It was inefficiently secreted and therefore primarily intracellular. The second construct coded for both extracellular, N-terminal Ig-fold domains. This was efficiently secreted into culture supernatant. The third construct coded for the full-length transmembrane molecule which localized to the cell surface. All constructs were monomers of predicted MW_r and were appropriately glycosylated. They retained epitopic specificity as demonstrated by binding to mAbs, and adhesion function as demonstrated by a rosetting assay.     

Zygomycosis. Report of four cases with formation of chlamydoconidia in tissue

The authors describe spheric to ovoid chlamydoconidia and mucoraceous hyphae in tissues from four patients, two with cutaneous and two with pulmonary zygomycosis. The diagnosis in each case was confirmed by immunofluorescence staining and the presence of characteristic hyphae in tissue. It is important that these conidia be recognized, because they can easily be mistaken for other fungi, nematode ova, or other microorganisms in tissue sections, thereby resulting in the potential for misdiagnosis.     

Nitric oxide participates in the intestinal pathology associated with murine syngeneic graft-versus-host disease

Syngeneic graft-versus-host disease (SGVHD) develops following lethal irradiation, reconstitution with syngeneic bone marrow, and treatment with a short course of cyclosporin A (CsA) therapy. The disease is characterized by the development of a T helper cell type 1-like cytokine response [interleukin (IL)-12, interferon-gamma (IFN-gamma), and tumor necrosis factor alpha], and macrophage activation is central to development of the syndrome. It has been shown that nitric oxide (NO) participates significantly in the development of allogeneic GVHD. Studies were initiated to determine if NO participates in the pathology associated with SGVHD. Significant increases in inducible NO synthase (iNOS) mRNA and circulating NO were found in the tissues of SGVHD versus control animals. Treatment of SGVHD animals with the iNOS inhibitor aminoguanidine (AG) reversed the pathology associated with this disease. Furthermore, AG treatment reduced the production of IL-12 and IFN-gamma mRNA in the colons of CsA-treated mice. These studies demonstrate that NO participates in the pathological processes that are associated with the development of murine SGVHD.     

Characterization of hepatitis B virus (Dane particle)

Hepatitis B virions (Dane particles) were purified from the sera of chronic HBsAg carriers by consecutive rate-zonal and isopycnic centrifugations in sucrose gradients using HBsAg, HBcAg and endogenous DNA polymerase activities as specific markers. Purified Dane particles, radiolabelled with Na ¹²⁵I by the chloramine-T procedure, had a higher buoyant density in CsCl (1.28 g/cm³) than unlabelled particles (1.26 g/cm³) and an estimated sedimentation coefficient of 280 s. ¹²⁵I-Dane particles were fully precipitated by anti-HBs and not by anti-HBc sera. Heavy and light density core particles were purified from heavy and light density populations of Dane particles and radioiodinated. The iodinated polypeptides of Dane particles and HBcAg were compared with those of the iodinated 22-nm form of HBsAg by SDS-PAGE. Iodinated Dane particles contained seven polypeptides with molecular weights of 18,000, 23,000, 26,000, 34,000, 43,000, 48,000 and 115,000. Heavy and light core particles contained three polypeptides with molecular weights of 18,000, 25,000 and 37,000.     

In vitro degradation of silk fibroin

A significant need exists for long-term degradable biomaterials which can slowly and predictably transfer a load-bearing burden to developing biological tissue. In this study Bombyx mori silk fibroin yarns were incubated in 1mg/ml Protease XIV at 37 degrees C to create an in vitro model system of proteolytic degradation. Samples were harvested at designated time points up to 12 weeks and (1) prepared for scanning electron microscopy (SEM), (2) lyophilized and weighed, (3) mechanical properties determined using a servohydraulic Instron 8511, (4) dissolved and run on a SDS-PAGE gel, and (5) characterized with Fourier transform infrared spectroscopy. Control samples were incubated in phosphate-buffered saline. Fibroin was shown to proteolytically degrade with predictable rates of change in fibroin diameter, failure strength, cycles to failure, and mass. SEM indicated increasing fragmentation of individual fibroin filaments from protease-digested samples with time of exposure to the enzyme; particulate debris was present within 7 days of incubation. Gel electrophoresis indicated a decreasing amount of the silk 25 kDa light chain and a shift in the molecular weight of the heavy chain with increasing incubation time in protease. Results support that silk is a mechanically robust biomaterial with predictable long-term degradation characteristics.     

New families of adhesion molecules play a vital role in platelet functions

Adhesion molecules play a crucial part in cell-matrix and in cell-cell interactions. These interactions, which are essential to the body's defense processes, involve adhesion molecules belonging to different families: integrins, immunoglobulins and selectins. Integrins are expressed by a large number of tissues, whereas other adhesion molecule families are restricted to a small number of cell types. A recent symposium dealt with the recruitment of circulating platelets at specific sites, their adhesion to extracellular matrix components and their activation by agonists leading to aggregation or attachment to other cells. These events, supporting hemostasis and thrombosis, involve integrins, selectins and other adhesion molecules. This report focuses on newly reported integrins (GPIa, GPIc, GPIIa), selectins (GMP-140) and GPIIIb, previously known as 'minor' surface oriented platelet glycoproteins. Major membrane glycoproteins such as GPIIb-IIIa (an integrin) and GPIb, which also play a vital role in platelet functions, have been extensively reviewed elsewhere.