Reversible activation of proactivator (factor B) of the alternative pathway without cleavage of the molecule

The serum of a patient (M.C.) with chronic glomerulonephritis and renal deposits of IgA, C3, and properdin converted C3 on overnight exposure of 0 degrees C. The cold reaction was dependent on immunoglobulin, initiating factor, Factors B and D, and magnesium but not on properdin. Factor B, the C3-cleaving enzyme in this reaction, was used in zymogen form. After participation in this rection, Factor B zymogen in M.C. serum could be fully activated by cobra venom factor (CVF) at 37 degrees C. That activation without fragmentation was not due to an abnormal form of Factor B was shown by its typical cleavage on incubation of MC. serum with CVF or C3b or after depletion of C3b inactivator. The evidence indicates that in the cold reaction only the initial C3 convertase of the alternative parhway is formed and that this enzyme is responsible for the observed C3 consumption.     

Molecular tools for presymptomatic testing in multiple endocrine neoplasia type 1

This study sought to determine the prevalence of upper-extremity musculoskeletal disorders (UEMSDs) among keyboard operators in Sao Paulo, Brazil, and to compare this prevalence with that among other office workers. One hundred and thirty keyboard operators (mean age 33 years, 60 male/70 female) and 138 office workers (mean age 35 years, 82 male/56 female) from two computing centers were interviewed by a research assistant using a standardized questionnaire. Symptomatic subjects, defined as those who reported upper extremity pain or lost work time due to pain in the preceding 12 months, were examined by a rheumatologist. Mean (SD) lengths of employment were 9 (6) years for keyboard operators and 8 (6) years for office workers. Upper-extremity pain during the preceding seven days was reported by 66 keyboard operators (51%) and by 18 office workers (13%) (p < 0.0001); during the preceding 12 months, by 90 keyboard operators (69%) and by 26 office workers (19%) (p < 0.0001). UEMSDs were diagnosed following physical examination in 50 keyboard operators and in 12 office workers (9%) (p < 0.0001). Tenosynovitis was the most common disorder diagnosed among the keyboard operators (n = 23). Among the keyboard operators the prevalence of UEMSDs was significantly lower for males (p = 0.017, OR = 0.38, 95%CI = 0.17-0.86). The presence of a diagnosed UEMSD was significantly associated with duration of employment (p = 0.005) and lack of or insufficient rest breaks (p = 0.012). Keyboard operators had significantly more UEMSDs than did office workers. Strategies aimed at the reduction of repetitive strain injuries among keyboard operators, such as the provision of adequate work breaks, should be evaluated.     

Biosynthetic pathways of glycerol accumulation under salt stress in Aspergillus nidulans

Vitamin D is best known for its role in the regulation of calcium and bone metabolism. The effects of the biologically active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25 (OH)2D3), are mediated by binding to a specific intracellular vitamin D receptor, which is present in most tissues including the skin where it regulates the growth of epidermal cells. Calcipotriol is a synthetic analogue of 1,25(OH)2D3. In vitro the activity of calcipotriol is comparable to that of 1,25(OH)2D3. In vivo, however, the risk of calcipotriol changing calcium metabolism is greatly reduced. Animal studies have established that calcipotriol is 100-200 times less calcaemic than 1,25(OH)2-D3. This low calcaemic activity is mainly due to the rapid metabolism of calcipotriol. This pharmacological profile makes calcipotriol an ideal candidate for topical treatment of hyperproliferative skin disorders, such as psoriasis. This paper reviews the clinical experience with calcipotriol in psoriasis patients.     

Age and family relationship accentuate the risk of insulin-dependent diabetes mellitus (IDDM) in relatives of patients with IDDM

The international community of diabetologists is rapidly becoming involved in intervention trials aimed at preventing insulin-dependent diabetes in high risk relatives. Whereas age and relationship to a proband with insulin-dependent diabetes mellitus interacting with detected islet cell autoantibodies (ICA) are risk factors, their independent contribution to that risk remains unclear. In a prospective study of 6851 nondiabetic relatives of 2742 probands conducted between 1979-1993, we found age, but not relationship, to be a dramatic risk variable in ICA-positive persons as estimated by the Cox regression model. The 5-yr risk of insulin-dependent diabetes mellitus was 66% for those found to have ICA detectable before age 10 yr, falling progressively to less than 16% for ICA-positive relatives over age 40 yr. In ICA-negative relatives, age and relationship are independent prognostic variables.     

Primary adenocarcinoma of the appendix

Two cases of carcinoma of the appendix presenting as appendicular masses are discussed. Carcinoma of the appendix is rare and hence a pre-operative diagnosis is seldom made. Awareness of the condition would naturally arouse suspicion of its presence, especially in elderly patients who present with cute appendicitis or an appendix mass. It is known to have occurred in an appendix stump several years after the initial appendicectomy, and also in a 17-year-old patient. The need for histological examination of all appendicetomy specimens is stressed. The operation of choice is right hemicolectomy, either as a primary or as a secondary procedure. This is associated with better survival rates than when the condition is treated by appendicectomy alone.     

The role of Saccharomyces cerevisiae coronin in the actin and microtubule cytoskeletons

Coronin was originally identified as a cortical protein associated with the actin cytoskeleton in Dictyostelium [1]. More recent studies have revealed that coronin is involved in actin-based motility, cytokinesis and phagocytosis [2,3]. Here, we describe the identification of a single homolog of coronin in Saccharomyces cerevisiae, which we show localizes to cortical actin patches in an actin-dependent manner. Unlike Dictyostelium mutants that lack coronin, yeast strains lacking coronin had no detectable defects in actin-based processes. This may reflect differences in the functions of the actin cytoskeleton in these two organisms. Previous studies have shown that cortical actin may mediate astral microtubule-based movements of the mitotic spindle in S. cerevisiae [4,5] and that, during mitosis in Dictyostelium, the regions of the cell cortex that overlap with astral microtubules become enriched in actin and coronin [6]. We therefore examined whether yeast lacking coronin had defects in the microtubule cytoskeleton. The mutant strains had increased sensitivity to the microtubule-destabilizing drug benomyl and an increased number of large-budded cells with short spindles. Further examination of microtubule-related processes, including spindle formation, migration of the mitotic spindle to the bud neck, spindle elongation, and translocation of the elongating spindle through the bud neck, failed to reveal any defects in the coronin mutant. Taken together, these results suggest that S. cerevisiae coronin is a component of the actin cytoskeleton that may interact with the microtubule cytoskeleton.     

The morphological characteristics of the lung lesions in straighteners working with brass-bronze alloys

Morphologic study of lung specimens obtained during diagnostic thoractomy in 6 workers engaged in smelting brass-bronze alloys showed changes typical of exogenous fibrosing alveolitis, namely, terminal bronchiolitis with pseudopolypous growth in the submucous layer, vasculitis (predominantly arteritis) paralleled by secondary recalibration of vessels, arteriolar and venular shunting, and microcirculatory disorders.