Chlamydial heat shock protein 60 localizes in human atheroma and regulates macrophage tumor necrosis factor-alpha and matrix metalloproteinase expression

High concentrations of bile acids have been reported as injurious to hepatocytes. We report the influence of various combinations of bile acids on the liver-specific function of cultured rat hepatocytes. Using 4 bile acids (glycocholate [GC], taurocholate [TC], glycohenodeoxycholate [GCDC], and taurochenodeoxycholate [TCDC]), we obtained 6 bile-acid mixtures, each containing equal amounts of 2 bile acids (total bile acids [TBA], 2 mM). Changes in gluconeogenesis, ureagenesis, DNA contents, medium alanine aminotransferase, and morphologies were compared among the paired bile acid compositions by measuring the C/CDC ratio ([GC + TC]/[GCDC + TCDC]) of each. In terms of their relative impairments of ureagenesis from greatest to least, the acids were GCDC, TCDC, and GC, which was almost the same as TC. When the C/CDC ratio was 0, the values of all parameters measured deteriorated. When the C/CDC ratio was 1 in the presence of 1 mM GCDC, only the rate of ureagenesis was diminished. When the C/CDC ratio was infinite, no hepatocellular injury was observed. GCDC and TCDC, together or separately, showed significant hepatocellular injury when the TBA concentration was 2 mM.     

Pathological changes according to the severity of asthma

BACKGROUND: There have been many studies concerning pathological changes in bronchial mucosa from asthmatics; however, few studies has been carried out to evaluate pathological changes according to the severity of asthma. OBJECTIVE: This study was designed to evaluate the cellular components in bronchoalveolar lavage fluid (BALF) and histological abnormalities in asthmatics according to the severity of asthma. METHODS: Bronchoalveolar lavages, bronchoscopic biopsies and ultrastructural examinations were performed in 13 asthmatics and 11 (BAL) or four (biopsies) non-asthmatic controls. The proportions of epithelial cells and correlations with PC20Meth which reflects bronchial hyperresponsiveness. Light microscopic examination revealed loss of epithelium, inflammatory cell infiltrations and thickening of the basement membrane which also showed significant correlation with PC20Meth. Hypertrophy of airway smooth muscles and hyperplasia of mucous glands were prominent in asthmatics but there was no difference according to the severity of asthma. Ultrastructural examination revealed that basement membrane thickening on light microscopic examination is due to the increased subepithelial collagen deposition with normal thickness of basal lamina. CONCLUSION: These data suggest that loss of epithelial cells, infiltration of inflammatory cells, especially eosinophils, and increased deposition of subepithelial collagen play major roles in determining the severity of asthma and non-specific bronchial hyperresponsiveness.     

Clinical and demographic features of Meige's syndrome

Fifty five patients with Meige's syndrome were examined for clinical and demographic features. The mean age of onset was 52.3 years. The peak age of onset was in the sixth decade with a male to female ratio of 1.11:1. The mean duration of illness was 3.7 years. Commonest initial symptom was increased blinking, seen in 30 cases (54.5%). Twenty five patients (45.4%) had complete syndrome of blepharospasm with oromandibular dystonia, whereas 24 patients (43.6%) had blepharospasm alone and the rest (6 patients, 10.9%) had oromandibular dystonia. The extension of spasm beyond cranial muscles was observed in 10 patients (18.1%). Eleven patients had family history of dystonia or other extrapyramidal disorders. Incidence of depression was high in these cases.     

Urate oxidase in prevention and treatment of hyperuricemia associated with lymphoid malignancies

Standard prophylaxis and treatment of malignancy-associated hyperuricemia in the USA has been allopurinol with vigorous hydration, urinary alkalinization and osmotic diuresis. Urate oxidase, the enzyme that converts uric acid to allantoin (a readily excreted metabolite that has 5- to 10-fold higher solubility than uric acid), is an alternative therapy; however, few published findings support this practice. Between February 1994 and December 1996, we administered non-recombinant urate oxidase (Uricozyme) to 126 children with newly diagnosed non-B cell acute lymphoblastic leukemia (ALL) during the first 5 days of chemotherapy with methotrexate, 6-mercaptopurine or both. Their blood levels of uric acid and other indicators of tumor lysis were measured at diagnosis and during treatment and then compared with findings in 129 similarly treated historical controls who had received allopurinol to control hyperuricemia. Clinical responses to urate oxidase were also determined in eight patients with newly diagnosed B cell ALL or advanced-stage non-Hodgkin lymphoma. Patients treated with urate oxidase had rapid and significantly greater decreases in their blood uric acid levels than did the historical controls (median maximal level during treatment, 2.3 vs 3.9 mg/dl, P < 0.001). They also had lower creatinine (0.6 vs 0.7 mg/dl, P = 0.01) and blood urea nitrogen (11 vs 24 mg/dl, P < 0.001) levels. Similar findings were made in the eight cases of B cell ALL or non-Hodgkin lymphoma. None of the patients required dialysis for acute renal failure. Six (4.5%) of the 134 children given urate oxidase had allergic reactions, manifested primarily by urticaria, bronchospasm and hypoxemia. Thus, non-recombinant urate oxidase is a more effective uricolytic agent than allopurinol but is associated with acute hypersensitivity reactions, even in patients without a history of allergy.     

Matrix induced re-differentiation of cultured rat hepatocytes and changes of CCAAT/enhancer binding proteins

Rat hepatocytes de-differentiate and proliferate when cultured on collagen-coated dishes in a chemically defined Hepatocyte Growth Medium in the presence of hepatocyte growth factor and epidermal growth factor. The addition of biomatrix derived from Engelbreth-Holm-Swarm (EHS) mouse sarcoma stops this process and leads to re-differentiation of the cells. We monitored DNA binding activity and protein levels of CCAAT/Enhancer Binding Proteins (C/EBPs) during these events by electrophoretic mobility shift assays and western blot analysis. We used plasma protein gene expression as a marker for the proliferation and differentiation phases. During the initial proliferation phase the DNA binding activity of C/EBPs decreased about 5-10 fold, mainly due to reduction of C/EBP alpha protein to nearly undetectable levels. Addition of EHS-gel prevented the further loss of C/EBP alpha protein and established a new steady state level. Since C/EBP beta proteins were affected to a much lesser extent, the C/EBP alpha:C/EBP beta ratio was greater in the presence of EHS-gel. Transferrin, alpha 1-antitrypsin, and albumin mRNA expression increased substantially. Thus stabilized C/EBP alpha expression, an increased C/EBP alpha:C/EBP beta ratio, and increased expression of liver specific mRNAs all correlated with the transition of proliferative to differentiated cells.     

Stability of sulfonamide antibiotics in spiked pig liver tissue during frozen storage

A bulk portion of homogenized pig liver tissue was spiked at room temperature with 0.2 mg/kg (twice the Australian maximum residue limit) of each of sulfathiazole, sulfachlorpyridazine, sulfadimidine (sulfamethazine), sulfaquinoxaline, and sulfadimethoxine. After subsampling and packaging, selected individual packaged units were tested to confirm homogeneity of the prepared material. The material was stored frozen at -20 degrees C and analyzed in replicate by liquid chromatography on 11 sampling dates over a period of about 6 months. Analytical data were plotted on a log-linear scale and subjected to linear regression on the basis of first-order kinetics for the decay. Storage stabilities (decay half-lives at -20 degrees C) calculated from the mean slope of regression lines were sulfadimethoxine, 567 days; sulfadimidine, 457 days; sulfachlorpyridazine, 312 days; sulfathiazole, 291 days; and sulfaquinoxaline, 271 days. Significant depletion (65% loss) of residue was observed for sulfaquinoxaline during preparation of spiked bulk liver tissue. An extension of the study to measure the storage stability of sulfaquinoxaline under accelerated decay conditions (refrigerator temperature, 4 degrees C) showed it to be relatively unstable, with a decay half-life of 11 days. Results demonstrate the need for both regulatory agencies and testing laboratories to be aware of potential errors associated with improper transport, storage, and handling of tissue samples submitted for antibiotic testing.     

Caries prevention

It is apparent that the use of fluoride in multiple measures has a significant impact upon the prevention of dental caries. These measures involve public health benefits of water fluoridation, professional fluoride treatments in the dental office, and the home use of effective fluoridated dentifrices, with the use of fluoride rinses and gels as adjuncts when needed. In many clinical situations, professional judgment is required to identify the most appropriate treatment measures to address the needs of individual patients.     

The potential of subtype-selective neuronal nicotinic acetylcholine receptor agonists as therapeutic agents

Neuronal nicotinic acetylcholine receptors (NAChRs) are pentameric ligand-gated ion channel receptors which exist as different functional subunit combinations which apparently subserve different physiological functions as indicated by molecular biological and pharmacological techniques. It is possible to design and synthesize novel compounds that have greater selective affinities and efficacies than nicotine for different NAChRs, which should translate into different behavioral profiles and therapeutic potentials. Examples of NAChR agonists studied are nicotine, SIB-1508Y, SIB-1553A and epibatidine. These compounds have different degrees of selectivity for human recombinant NAChRs, different neurotransmitter release profiles in vitro and in vivo and differential behavioral profiles. Preclinical studies suggest that SIB-1508Y is a candidate for the treatment of the motor and cognitive deficits of Parkinson's disease, whereas SIB-1553A appears to have potential as a candidate for the treatment of Alzheimer's disease. Epibatidine has a strong analgesic profile, however the ratio between pharmacological activity and undesirable effects is so low that it is difficult to envisage the use of this compound therapeutically. Nicotine has a broad profile of pharmacological activity, for instance demonstrating activity in models for cognition and analgesia. As for epibatidine, the adverse effects of nicotine severely limits its therapeutic use in humans. The discovery of subtype-selective NAChR agonists such as SIB-1508Y and SIB-1553A provides a new class of neuropsychopharmacological agents with better therapeutic ratios than nonspecific agents such as nicotine.     

Pravastatin has cholesterol-lowering independent effects on the artery wall of atherosclerotic monkeys

The amino acid sequence of triosephosphate isomerase from Trypanosoma brucei, Trypanosoma cruzi, and Leishmania mexicana have an identity of 68%. Using the numbering system for the T. brucei enzyme, in their aligned sequences, the T. cruzi and leishmanial enzymes have cysteine residues at positions 14, 40, 117 and 126. T. brucei triosephosphate isomerase has cysteine residues at positions 14, 40 and 126, and a valine residue at position 117. Dithionitrobenzoic acid and methylmethane thiosulfonate inhibited the three enzymes, but T. cruzi triosephosphate isomerase was more than 100-fold more sensitive. The sensitivity of wild type triosephosphate isomerase from T. cruzi and T. brucei to the reagents was equal to that of the Cys117Val and Val117Cys mutant enzymes, respectively. Triosephosphate isomerases that have cysteine residues at positions 40 and 126, but lack a cysteine residue at position 14 are insensitive to methylmethane thiosulfonate. Thus, sulfhydryl reagents act on Cys14. At stoichiometric concentrations, the reagents inhibited the three enzymes as a consequence of structural alterations as measured by binding of 8-anilino-1-napthalenesulfonic acid to previously buried hydrophobic regions. However, the times for half-maximal alterations were 10 min, 15 hours and over 30 hours for T. cruzi, T. brucei and L. mexicana triosephosphate isomerase, respectively. The effect of pH on the action of the sulfhydryl reagents and molecular modeling showed no differences in the solvent accessibility of Cys14. As Cys14 forms part of the dimer interface, the data indicate that, in the three enzymes, barriers of different magnitude hinder the interaction between the sulfhydryl reagents and Cys14. The barrier is lower in T. cruzi triosephosphate isomerase which makes its dimer interface more susceptible for perturbation.