Autoantibody titers against OxLDL are correlated with Achilles tendon thickness in patients with familial hypercholesterolemia

Achilles tendon xanthomas are associated with increased cardiovascular risk in patients with familial hypercholesterolemia (FH). Oxidized low density lipoprotein (OxLDL), the antibodies against OxLDL, and the LDL-associated phospholipase A(2) (Lp-PLA(2)) may play important roles in atherogenesis. We investigated the possible association between plasma levels of OxLDL, Lp-PLA(2) activity, and autoantibody titers against various types of mildly OxLDL with Achilles tendon thickness (ATT). ATT was determined by sonography in 80 unrelated heterozygous FH patients. Three different types of mildly OxLDL were prepared: OxLDL(L), OxLDL(P), and OxLDL(D), at the end of the lag, propagation, and decomposition phases of oxidation, respectively. Similar types of OxLDL were also prepared after inactivation of the LDL-associated Lp-PLA(2). These types were denoted OxLDL(-)(L), OxLDL(-)(P), and OxLDL(-)(D). FH patients exhibited significantly higher plasma OxLDL levels and serum IgG titers against OxLDL(P) and OxLDL(D) compared with 40 normolipidemic apparently healthy controls. ATT values were positively correlated with autoantibody titers against OxLDL(P) and OxLDL(D); however, in multiple regression analysis, ATT was independently associated only with the autoantibody titers against OxLDL(D). We conclude that the IgG autoantibody titers against OxLDL(D) but not OxLDL or Lp-PLA(2) may play an important role in the pathogenesis of Achilles tendon xanthomas in FH patients.     

Map location of the pcbA mutation and physiology of the mutant.

The obligate aerobe Cowpea Rhizobium sp. strain 32H1 in axenic culture is able to fix N2 when grown under 0.2% O2 but not when grown under 21% O2. It was, therefore, of interest to investigate ATP synthesis in these cells grown under the two conditions. When respiring in buffers having pHs ranging from 6 to 8.5, cells grown under either O2 tension maintained an intracellular pH more alkaline than the exterior. The transmembrane chemical gradient of H+ (delta pH) was essentially the same under both conditions of growth, decreasing from ca. 90 mV at medium pH 6 to ca. 30 mV at pH 8.5. However, the transmembrane electrical gradient (delta psi) was significantly higher in cells grown under 21% O2 (150 to 166 mV) than in cells grown under 0.2% O2, the latter being 16 mV at pH 6 and increasing to 88 mV at pH 8.5. Therefore, the proton motive force of 21% O2-grown cells ranged from 237 mV at external pH 6 to 185 mV at pH 8.5, compared with a proton motive force of 114 to 121 mV in the 0.2% O2-grown cells. The cells grown in 0.2% O2 had the same proton motive force whether tested at 21 or at 0.2% O2. The phosphorylation potential, calculated from the intracellular ATP, ADP, and Pi concentrations, was 424 mV in the 21% O2-grown cells and 436 mV in the 0.2% O2-grown cells. Thus, the 21% O2-grown cells translocated 1.8 to 2.3 H+/ATP synthesized by the H+-ATPase, whereas the H+/ATP ratio for 0.2% O2-grown cells was 3.7 to 3.8.     

A note on the Wilcoxon-Mann-Whitney test for 2 X kappa ordered tables

Biological and medical investigations often use ordered categorical data. When two groups are to be compared and the data for the groups fall in three or more ordered categories, the Wilcoxon-Mann-Whitney (WMW) test uses information in the ordering to give a test that is usually powerful against shift alternatives. However, such applications of WMW often involve distributions for which extensive ties play an important role. Newly available computer programs for performing exact tests give deeper insights into the characteristics of the exact WMW distributions and the suitability of normal approximations. We offer practical advice, based on experience with published biomedical data sets and on numerical studies of hypothetical ordered tables, for the use of WMW and its normal approximations.     

Epidemiological survey of rhinosporidiosis in Kanyakumari district of Tamil Nadu

One hundred and twelve nasal polyps received along with full history from three different hospitals of Kanyakumari district of Tamil Nadu during the period 1983–1987 were found positive for rhinosporidiosis on histopathological examination. Among the four taluks (countries) the majority of the cases (41.1 per cent) came from Agastheeswaram, followed by Kalkulam (28.6 per cent), Thovalai (17.0 per cent) and Vilavancode (13.3 per cent). The 11–20 years age group found to be highly susceptible (60 per cent). There was no sex prepondence in contracting the disease as the cases were evenly distributed between both sexes. These findings exhibited the endemic nature of the disease in Kanyakumari district.Unreported cases to an extent of 9 to 40 per cent were encountered during the ENT disease diagnostic camps conducted in nine high incidence villages. Further 8 more cases were detected in addition to cases attended in the hospitals and ENT camps when a complete enumeration of cases was undertaken in Pallam village. Thus the actual number of cases found in the district need a stratified random sampling.     

Synaptonemal complex damage induced by clastogenic and anti-mitotic chemicals: implications for non-disjunction and aneuploidy

Mice were treated with mitomycin C, cyclophosphamide, amsacrine, colchicine, or vinblastine sulfate, and meiotic prophase cells analyzed for synaptonemal complex (SC) damage. All test agents caused synaptonemal complex breakage and synapsis irregularities, although propensities for inducing specific types of damage at S-phase or prophase stages varied among the chemicals. The data indicate that SC analysis can reveal chemical-specific alterations to meiotic homologue pairing/synapsis which have not generally been recognized, and which theoretically may be implicated in non-disjunction.     

Inorganic pyrophosphatase activity in cell-free extracts of Ureaplasma urealyticum

Cell-free extracts of Ureaplasma urealyticum strains Pi and T960 (CX8) (serovars 6 and 8, respectively) metabolized inorganic pyrophosphate (PPi). The inorganic pyrophosphatase (PPase) activity was greatest with Mg2+ as cofactor, but Mn2+ acted as a poor substitute. The PPases of the two serovars differed electrophoretically. Although the highest PPase activity was obtained using PPi as substrate, the enzyme could also utilize to a lesser degree both tripolyphosphate and trimetaphosphate. No activity was observed against beta-glycerophosphate, naphthyl phosphates, glucose 6-phosphate, fructose 6-phosphate, fructose 1,6-bisphosphate, thiamin pyrophosphate, phosphoribosylpyrophosphate, ADP or ATP. Acid- and alkaline-phosphatase activities were observed with naphthyl phosphates as substrates, but they did not have the same electrophoretic mobility on gels as the PPase activity. U. urealyticum PPase was inhibited by oxidized glutathione, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, phenylglyoxal, p-chloromercuribenzoic acid, Mn2+, Zn2+ and Ca2+. Neither reduced glutathione, L-cysteine nor Co2+ enhanced activity. PPi can act as a substrate or regulator of certain metabolic reactions, and PPi metabolism can function in bacterial bioenergetics; its role in ureaplasmas is presently unclear.     

Human transforming growth factor-beta 3: recombinant expression, purification, and biological activities in comparison with transforming growth factors-beta 1 and -beta 2

Recent cDNA characterization has predicted the existence of a new member of the transforming growth factor family, transforming growth factor-beta 3 (TGF beta 3). However, nothing is known about the biological activities of the TGF beta 3 protein, since it has not been purified from any natural sources. We report here the recombinant expression in mammalian cells and the purification to apparent homogeneity of human TGF beta 3. The TGF beta 3 was evaluated in comparison with purified TGF beta 1 and TGF beta 2 in several assays for its effects on stimulation or inhibition of proliferation of mammalian cells. These analyses revealed that TGF beta 3 exerts activities similar to the two other TGF beta species, but that there are distinct differences in potencies between the different TGF beta forms depending on the cell type and assay used.     

Basic pancreatic trypsin inhibitor has unusual thermodynamic stability parameters

The stability parameters delta Gst, delta Hst and delta Sst of native basic pancreatic trypsin inhibitor (BPTI) have been characterized by microcalorimetric unfolding studies in various buffer solutions, at different pH values and in the presence of guanidine hydrochloride. The unfolding enthalpy of BPTI, in contrast ot other globular proteins, exhibits a very small dependence on temperature, which results in a characteristic different temperature dependence of the Gibbs energy of stabilization. BPTI has a very high specific Gibbs energy of stabilization, which renders the slow exchange rates of amide protons understandable. Comparison of the unfolding entropy of BPTI at 110 degrees C with corresponding values of other proteins, revealed that the delta S values of BPTI are lower by 2.9 J/(K X residue). This lower value of the unfolding entropy is in good agreement with predictions of a theoretical study by Poland & Scheraga (1965) where the influence of crosslinks on the configurational entropy has been studied. Additionally, we were able to calculate an interaction enthalpy per site of -5.6 kJ/mol based on the measurements of unfolding of BPTI in 6 M-guanidine hydrochloride.