Characterisation of G serotype dependent non-antibody inhibitors of rotavirus in normal mouse serum

Serotype specific (non-immunoglobulin) inhibitors of rotavirus have been identified in normal mouse serum obtained from BALB/c, CBA, and BL10 mice. Sialic acid was essential for the neutralising activity sera treated with the neuraminidase from Vibrio cholerae failed to neutralise rotavirus. G serotypes 4, 5, 7, 8, 9, and 10 were unaffected by the inhibitor(s) while G serotypes 1, 2, 6 and two G3 strains were neutralised to significant titres. Assessment of neutralisation of reassortants suggested that VP7 is the virus protein involved in the interaction although it remains possible that VP7 is influencing VP4 binding. Analysis of the sera by Western blot followed by virus overlay confirmed that binding is dependent on the presence of sialic acid. The human strain tested, Wa, bound to two (glyco) proteins (50 and 80 kDa) while the bovine strains tested, NCDV and UK bound to one (55 kDa) and two (36 and 55 kDa) proteins respectively. This indicates that while the bovine rotaviruses may bind to a common element, the human strain binds to clearly distinct proteins. We propose that these inhibitors interact with animal rotaviruses in a manner analogous to that by which they attach to target cells. The glycoprotein to which NCDV bound was purified and identified by N-terminal sequencing as murine alpha-1-anti-trypsin (MuAAT) and was confirmed to possess both neutralisation and anti-trypsin activity. Since MuAAT is known to possess only three N-linked glycans, identification and analysis of the actual virus-binding structure should now be possible.     

Polymorphisms of complement component I and C1R subcomponent of C1 in nine aboriginal Taiwanese populations

Complement component I (IF) and C1R subcomponent of C1 (C1R) types were determined by isoelectric focusing and subsequent immunoblotting techniques for 658 individuals from nine aboriginal Taiwanese populations. The frequency of the IF*A allele ranges from 0.075 (Bunun) to 0.430 (Saisiat), and a new variant allele IF*B2 was found to have polymorphic frequency in the Atayal. The frequency of the C1R*1 allele ranges from 0.410 (Yami) to 0.650 (Atayal), and the frequency of the C1R*2 allele ranges from 0.265 (Atayal) to 0.586 (Saisiat). The C1R*5 allele was found in five populations (Atayal, Bunun, Ami, Puyuma, Yami), and the C1R*9 allele was found in two populations (Tsou, Puyuma). The results indicate a remarkable degree of genetic variability among these populations. The variability may reflect long-term genetic and geographic isolation of each population.     

Polypeptide pattern of human breast epithelial cells following human chorionic gonadotropin (hCG) treatment

Numerous attempts have made to describe the particular protein pattern of malignant cells by using high resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The placental hormone human chorionic gonadotropin (hCG) inhibits tumor initiation and progression in experimental animals and has an inhibitory effect on the proliferation of human breast epithelial cells (HBEC) in vitro. The inhibitory effect on the immortalized HBEC MCF-10F is accompanied by the immunocytochemical expression of inhibin alpha and beta subunits by treated cells. With the purpose of clarifying the molecular mechanisms involved in this effect, the pattern of protein synthesis and mRNA were studied by 2-D PAGE in the immortalized HBEC MCF-10F cells treated in vitro 1001U for 24 h. The effect of hCG treatment on the synthesis of MCF-10F cells was monitored by labeling both control and treated cells with [S35]methionine and separation by 2-D PAGE. At least 11 proteins were preferentially synthesized and five specific polypeptides were decreased in hCG treated cells in comparison with controls. The hCG induced at least four new mRNAs which encoded protein in the molecular mass range of 24-72 kDa. It also increased the expression of at least six mRNAs and reduced the expression of least four mRNAs in comparison with control cells. The hCG-treated cells actively synthesized a 33-kDa polypeptide which was not present in control cells. The nature of this hCG-inducible 33 kDa protein elucidated by immunoprecipating [S35]methionine-labeled proteins with antisera directed against rat inhibin subunit alpha and beta b.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cell swelling activates separate taurine and chloride channels in Ehrlich mouse ascites tumor cells

The photosensitizing properties of tetrasulphonated Al- and Zn-phthalocyanines (AlPcS4 and ZnPcS4) in lymphoma cells were studied as a function of the pre/post-illumination incubation time. Photocytotoxicity increased with incubation time, ranging from a transient cell-cycle arrest to cell killing. Under all experimental conditions, the phototoxicity of ZnPcS4 was markedly higher than that of AlPcS4. The primary photoprocesses initiated by metallo-phthalocyanines (MePcS4) in the cells were probed with DMPO/esr spin-trapping techniques. Under all incubation conditions the intracellularly bound MePcS4 sensitized formation of three different types of DMPO spin-adducts: DMPO/OH (hydroxyl radical), DMPO/R (organic carbon-centred radical(s)) and an unidentified simple nitroxyl, referred to as DMPO/ox. The yields of trapped radicals depended on the length of the incubation with the dyes prior to illumination and the formation of spin-adducts was shown to be intracellular. The ability of DMPO to protect cells from the photocytotoxic effects of Al- and ZnPcS4, combined with the generation of carbon-centred spin-adducts is direct evidence for the involvement of free-radical-mediated damage of cellular constituents.     

Corosolic acid isolated from the fruit of Crataegus pinnatifida var. psilosa is a protein kinase C inhibitor as well as a cytotoxic agent

We report a case of left-sided hydronephrosis and ureteropelvic urinary extravasation due to a large left iliac artery aneurysm. Urinoma was diagnosed preoperatively by contrast-enhanced computed tomography. The patient was successfully treated by percutaneous nephrostomy and ureteral double J stent placement followed by staged operative repair.     

Age-related alterations in pre-synaptic and receptor-mediated cholinergic functions in rat brain

Fractional [3H]acetylcholine (ACh) release and regulation of release process by muscarinic receptors were studied in corpus striatum of young and aged rat brains. [3H] Quinuclidinyl benzilate (QNB) binding and carbachol stimulated phosphoinositide turnover, on the other hand, were compared in striatal, hippocampal and cortical tissues. High potassium (10 mM)-induced fractional [3H]ACh release from striatal slices was reduced by aging. Although inhibition of acetylcholinesterase with eserine (20 microM) significantly decreased stimulation-induced fractional [3H]ACh release in two groups of rats, this inhibition slightly lessened with aging. Incubation of striatal slices with muscarinic antagonists reversed eserine-induced inhibition in fractional [3H]ACh release with a similar order of potency (atropine = 4-DAMP > AF-DX 116 > pirenzepine) in young and aged rat striatum, but age-induced difference in stimulated ACh release was not abolish by muscarinic antagonists. These results suggested that fractional [3H]ACh release from striatum of both age groups is modulated mainly by M3 muscarinic receptor subtype. Although both muscarinic receptor density and labeling of inositol lipids with [myo-3H]inositol decreased with aging, carbachol-stimulated [3H]myo inositol-1-fosfat (IP1) accumulation was found similar in striatal, cortical and hippocampal slices.     

Clostridium difficile infection in patients with reactive arthritis of undetermined etiology

BACKGROUND: Multiple sensory neuropeptides are present in human airways and may contribute to diseases such as asthma. This study quantified and characterised substance P (SP), neurokinin A (NKA), and calcitonin gene related peptide (CGRP) immunoreactivity in bronchoalveolar lavage fluid in asthmatic and normal subjects. METHODS: Using specific radioimmunoassay (RIA), SP, NKA and CGRP were measured in bronchoalveolar lavage fluid from asthmatic subjects (n = 5), normal subjects (n = 5), atopic non-asthmatic subjects (n = 6), and asthmatic subjects four hours after allergen challenge (n = 12). Peptide immunoreactivity was characterised using high performance liquid chromatography (HPLC) and RIA. RESULTS: No SP or CGRP immunoreactivity was detected in any of the fractions from samples after extraction, HPLC, and RIA. Non-specific binding resulted in spurious SP immunoreactivity being detected in bronchoalveolar lavage fluid when no extraction process was employed. NKA was detected in significant amounts in asthmatic (median 550, range 425-625 pg/ml) and normal subjects (median 725, range 350-1425 pg/ml). The level of NKA was significantly higher in the asthmatic subjects after allergen challenge (median 750, range 350-1250 pg/ml) than in unchallenged asthmatic subjects (median 600, range 425-600 pg/ml, p < 0.01). CONCLUSIONS: Extraction and characterisation of peptides from bronchoalveolar lavage fluid must be performed to ensure that the measured immunoreactivity represents target peptide. NKA is present in bronchoalveolar lavage fluid in high concentrations and is the predominant tachykinin. The concentrations of NKA are similar in normal subjects and subjects with mild asthma.