Abdominal zygomycotic thromboangiitis in a patient with AML and t(1;13;14)

 The case report of a 61 year-old man with AML M2 FAB, t(1; 13; 14) and zygomycotic mesenterial thromboangiitis is presented. Two induction cycles of chemotherapy were administered due to primary drug resistance. They were complicated by pneumonia, colonic pseudo-obstruction and perforation with peritonitis. The patient died on the 40th day of therapy, 4 days after undergoing palliative surgery. Zygomycotic thromboangiitis, which very probably contributed to the intestinal perforation, was confirmed morphologically at necropsy. The novel complex chromosomal translocation t(1; 13; 14) (q31; q32; q24) and the problems connected with the diagnosis of invasive fungal infections are discussed. Received: 26 January 1996 / Accepted: 12 June 1996     

Monoclonal antibodies against transferrin. Precipitating mixtures and lack of inter-species cross-reactivity

Five stable hybridoma lines were prepared using the myeloma cell line P3-X63-Ag.653 and spleen cells of mice hyperimmunized by pig transferrin. All hybridomas grew well in mouse peritoneal cavity and produced antibodies of the IgG₁ subclass. Antibody preparations obtained from ascitic fluids tested for their capacity of antigen precipitation. No precipitation was obtained with single antibodies and with pairs of antibodies. Three out of 10 possible triads gave clear and sharp precipitation zones and rings in immunodiffusion tests performed in agar gel. All 5 antibodies were shown by quantitative enzyme-immunoassay to be specific for pig transferrin: no cross-reaction was obtained with mouse, human, horse and sheep transferrins.     

The relation between lymphocyte profile in BALF and the course of sarcoidosis based on short term observation

The aim of this study was to assess how the extent of the number and percentage of lymphocytes in BALF and also the CD4 to CD8 ratio can help to predict the short outcome in sarcoidosis. Material consisted of 74 patients, 39 men and 35 women in the age from 23 to 58 years. 11 patients had chest lesions in stage I, 43 in stage II and 20 in stage III. Clinical markers of activity (fever, erythema nodosum) were present in 22 cases. Extrathoracic lesion were present in 31 and abnormal pulmonary function in 30. In all patients BAL was done before treatment and lymphocyte count, percentage and CD4/CD8 ratio was calculated. 50 patients were treated with corticosteroids and 24 were observed without treatment. After 6-12 month of observation regression of sarcoid lesions was observed in 46 of 50 patients treated with corticosteroids and in 17 out of 24 patients observed without treatment. There were no differences in lymphocyte count and percentage in BALF and in the short term outcome between group treated with corticosteroids and without treatment. The patients in whom regression of lesions was observed have however significantly higher CD4/CD8 ratio than others.     

Synthesis of TGF-beta 1 by vascular endothelial cells is correlated with cell spreading.

Cultured vascular endothelial cells (ECs) secrete transforming growth factor beta (TGF-beta) which stimulates intimal smooth muscle cells to synthesize increased amounts of lipoprotein-binding proteoglycans. We report here that the amount of TGF-beta 1 synthesized by ECs is correlated with EC density and cell spreading. ECs cultured at low density synthesized and secreted 2- to 3-fold more TGF-beta, measured by the Mink lung cell assay, than intermediate and high density cultures, and this increase in secreted protein was matched by a corresponding increase in mRNA for TGF-beta 1 measured by Northern hybridization using a [32P]-labeled cDNA probe for TGF-beta 1. TGF-beta 1 mRNA was detected in individual cells by in situ hybridization with the cDNA probe labeled with [35S] and with a [35S]-labeled 30-mer antisense oligonucleotide. In situ mRNA levels did not relate to cell density per se but to cell area. The larger the area of substratum covered, the more mRNA per cell, irrespective of cell density. For cell areas in the range 500-1,200 microns 2, a doubling of cell area resulted in an approximately 3-fold increase in mRNA. Cells cultured at low density had a larger mean cell area than cells cultured at higher densities, and this increased area was sufficient to account for the increased TGF-beta 1 mRNA levels found for the low density cultures by Northern hybridization. Despite variations in cell area, cell volumes did not change significantly with cell density.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of physical activity on vertebral strength during late adolescence

Background contextReduced vertebral strength is a clear risk factor for vertebral fractures. Men and women with vertebral fractures often have reduced vertebral size and bone mineral density (BMD). Vertebral strength is controlled by both genetic and developmental factors. Malnutrition and low levels of physical activity are commonly considered to result in reduced bone size during growth. Several studies have also demonstrated the general relationship between BMD and physical activity in the appendicular skeleton.PurposeIn this study, we wanted to clarify the role of physical activity on vertebral bodies. Vertebral dimensions appear to generally be less pliant than long bones when lifetime changes occur. We wanted to explore the association between physical activity during late adolescence and vertebral strength parameters such as cross-sectional size and BMD.Study designThe association between physical activity and vertebral strength was explored by measuring vertebral strength parameters and defining the level of physical activity during adolescence.Patient sampleThe study population consisted of 6,928 males and females who, at 15 to 16 and 19 years of age, responded to a mailed questionnaire inquiring about their physical activity. A total of 558 individuals at the mean age of 21 years underwent magnetic resonance imaging (MRI) scans.MethodsWe measured the dimensions of the fourth lumbar vertebra from the MRI scans of the Northern Finland Birth Cohort 1986 and performed T2* relaxation time mapping, reflective of BMD. Vertebral strength was based on these two parameters. We analyzed the association of physical activity on vertebral strength using the analysis of variance.Results and conclusionsWe observed no association between the level of physical activity during late adolescence and vertebral strength at 21 years.     

The immune regulatory protein B7-H3 promotes osteoblast differentiation and bone mineralization

B7-H3, a member of the B7 family of the Ig superfamily proteins, is expressed on the surface of the antigen-presenting cells and down-regulates T cell functions by engaging an unknown counterreceptor on T cells. Although B7-H3 is ubiquitously expressed, its potential nonimmune functions have not been addressed. We found that B7-H3 is highly expressed in developing bones during embryogenesis and that its expression increases as osteoblast precursor cells differentiate into mature osteoblasts. In vitro bone formation by osteoblastic cells was inhibited when B7-H3 function was interrupted by the soluble recombinant protein B7-H3-Fc. Analysis of calvarial cells derived from neonatal B7-H3 knockout (KO) mice revealed normal numbers of osteoblast precursor cells possessing a normal proliferative capacity. However, the B7-H3-deficient calvarial cells exhibited impaired osteogenic differentiation, resulting in decreased mineralized bone formation in vitro. These results suggest that B7-H3 is required for the later phase of osteoblast differentiation. Although B7-H3 KO mice had no gross skeletal abnormalities, they displayed a lower bone mineral density in cortical (but not trabecular) bones compared with WT controls. Consistent with the reduced bone mineral density, the femurs of B7-H3 KO mice were more susceptible to bone fracture compared with those of WT mice. Taken together, these results indicate that B7-H3 and its unknown counterreceptor play a positive regulatory role in bone formation. In addition, our findings identified B7-H3 as another molecule that has a dual role in the bone-immune interface.     

Amino-Acid Sequence of Rabbit Skeletal Tropomyosin and Its Coiled-Coil Structure

A tentative amino-acid sequence for the COOH-terminal half of rabbit skeletal tropomyosin is reported. These studies confirm our previous conclusions that this tropomyosin consists of several different but similar polypeptide chains. In the sequence, nonpolar residues occur in two series at intervals of seven residues. Amino-acid residues in series I are three residues on the NH(2)-terminal side of, and four residues on the COOH-terminal side of, residues in series II. The presence of occasional charged or ambivalent residues in the positions of series I or II does not lead to a disruption of this long-range pattern. The majority of residues located between the nonpolar residues are charged or polar amino acids. Two highly similar or identical alpha-helices with the reported sequence can be packed together in parallel in a coiled-coil structure. These may be in register or staggered by seven residues or some multiple of it. The observation that groups of small hydrophobic side chains appear to alternate with groups of bulky side chains suggests that a staggered arrangement of the two alpha-helices would maximize the regularity and hydrophobic interactions of the coiled-coil. Model building considerations show that this would occur with a stagger of 14 residues. Such an arrangement could account for the end-to-end aggregation of tropomyosin in solution, and in crystal and tactoid filaments. However, a structure in which the two polypeptides are in register cannot be ruled out.