Cadmium,zinc, copper and metallothionein levels in human liver

The concentrations of cadmium, zinc, copper and metallothionein in the autopsy samples of liver among the inhabitants of Lód? (Poland) were determined. The cadmium levels were low in the range of 1.5 to 5.8 micrograms/g. The concentration of metallothionein determined by the Hg-method was high (0.160-1.665 mumol Hg/g); it was mainly a Zn-thionein. The percentage of hepatic zinc bound in the MT-fraction increased with the overall content of zinc in the liver. The elevation of zinc in the liver occurs in the proportion required for the saturation of metal-binding ligands of metallothionein. The role of cadmium remains less clear. Our results suggest that the metallothionein level in the liver increase significantly in response to elevated cadmium concentrations. This response, however, is in high excess to the demand which is justified stoichiometrically.     

MR imaging of viscoelastic properties

Mechanical waves in magnetic resonance imaging, which have been suggested for possible clinical applications, were analyzed with regard to imaging of the viscoelastic properties of large objects. The method is based on the Larmor frequency modulation caused by the application of mechanical waves. Possible clinical applications include all diseases that result in a change in the mechanical properties of biologic tissues (eg, atherosclerosis).     

Epitope of the vaccine-type Bordetella pertussis strain 186 lipooligosaccharide and antiendotoxin activity of antibodies directed against the terminal pentasaccharide-tetanus toxoid conjugate

Lipooligosaccharides (LOS) isolated from Bordetella pertussis strains 186 and 606 were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high-resolution magic angle spinning nuclear magnetic resonance (NMR). These analyses distinguished between the LOS of strains 186 and 606, suggesting that the structure of LOS in B. pertussis is heterogeneous. The pentasaccharide was selectively cleaved from LOS of B. pertussis strain 186, purified, and covalently linked to a monomer fraction of tetanus toxoid. Injection of rabbits with the neoglycoconjugate emulsified in complete Freund's adjuvant yielded immunoglobulin G antibodies that were reactive with the LOS. These antibodies reacted strongly with B. pertussis LOS possessing the complete dodecasaccharide, as determined by an enzyme-linked immunosorbent assay, immunoblotting, and flow cytometry with intact, live bacterial cells. The binding epitope within the pentasaccharide was investigated by saturation transfer difference (STD) NMR spectroscopy. Protons H-1 and H-4 of the terminal alpha-D-GlcpNAc and proton H-6 and protons of an N-methyl group at H-4 of 3-substituted beta-L-FucpNAc4NMe exhibited the largest saturation transfers. STD NMR experiments confirmed that the immunodominant epitope recognized by the antineoglycoconjugate antibodies is located predominantly in the distal trisaccharide of B. pertussis 186 LOS. The antipentasaccharide antibodies induced by the conjugate inhibited the secretion of tumor necrosis factor alpha, interleukin-6, and NO by LOS-stimulated J774A.1 cells.     

Use of type 1 /type 2 chimeric polioviruses to study determinants of poliovirus type 1 neurovirulence in a mouse model

We previously described the characteristics of a type 1/type 2 (PV-1/PV-2) chimeric poliovirus, v510, which contains the six amino acids specific for PV-2 in the B-C loop of VP1. This virus was found to be mouse-adapted, as PV-2 and in contrast with PV-1. Determinants of host range were studied in detail and are reported here. PV-1/PV-2 chimeras containing partial PV-1----PV-2 substitutions in the B-C loop of VP1 were obtained by making use of a mutagenesis cartridge on PV-1 cDNA. Analysis of mouse neurovirulence of these chimeras, when correlated with the three-dimensional structure of the v510 capsid, revealed that PV-2 residues important for mouse tropism are those which determine the particular conformation of the B-C loop of VP1 in v510. The mutation of the adenine residue at position 480 of the 5' noncoding region into a guanine residue has been shown to be an important determinant of PV-1 attenuation in monkeys. We show that introduction of this mutation in the v510 genome results in a virus which is partially attenuated for mice. This suggests that analysis of genomic determinants important for PV-1 neurovirulence could be carried out in a mouse model by making use of a mouse-adapted PV-1/PV-2 chimera.     

Usefulness of high doses of glucocorticoids and hyperbaric oxygen therapy in sudden sensorineural hearing loss treatment.

OBJECTIVE: We investigated the effect of pharmacologic (steroids, vasodilators, vitamins, and Betaserc) and hyperbaric oxygen therapy on patients with sudden sensorineural hearing loss. METHODS: The pharmacologic arm of the study consisted of 52 patients with defined sudden sensorineural hearing loss treated simultaneously in the ENT Department and National Center for Hyperbaric Medicine of the Medical University of Gdansk, Poland, from 1997 to 2000 (Group A). The hyperbaric oxygen therapy consisted of exposure to 100% oxygen at a pressure of 250 kPa for a total of 60 minutes in a multiplace hyperbaric chamber. The control group included 81 patients with defined sudden sensorineural hearing loss treated in the ENT Department, Medical University of Gdansk, from 1980 to 1996 (Group B). Both groups were comparable regarding the age of the patients, season of hearing loss occurrence, tinnitus and vestibular symptom frequency, delay before therapy, and average threshold loss before the start of treatment. The treatment results (hearing gain) were estimated using pure-tone audiometry. We retrospectively analyzed the audiograms of all patients. RESULTS: Patients from Group A (blood flow-promoting drugs, glucocorticoids in high doses, betahistine, and hyperbaric oxygen therapy) showed significantly better recovery of hearing levels compared with those from Group B (blood flow-promoting drugs and glucocorticoids in low doses) at seven frequencies (500, 1,000, 2,000, 3,000, 4,000, 6,000, and 8,000 Hz) (p < 0.05) and four groups of frequencies (pure-tone average, high-tone average, pure middle-tone average, and overall average) (p < 0.05). Percentage hearing gain in all investigated frequencies was also better in Group A versus Group B, and the differences were statistically significant (p < 0.05). CONCLUSION: We conclude that hyperbaric oxygen therapy with high doses of glucocorticoids improves the results of conventional sudden sensorineural hearing loss treatment and should be recommended. In addition, the best results are achieved if the treatment is started as early as possible.     

(-)-Epigallocatechin-3-gallate is a new inhibitor of hepatitis C virus entry

Here, we identify (-)-epigallocatechin-3-gallate (EGCG) as a new inhibitor of hepatitis C virus (HCV) entry. EGCG is a flavonoid present in green tea extract belonging to the subclass of catechins, which has many properties. Particularly, EGCG possesses antiviral activity and impairs cellular lipid metabolism. Because of close links between HCV life cycle and lipid metabolism, we postulated that EGCG may interfere with HCV infection. We demonstrate that a concentration of 50 μM of EGCG inhibits HCV infectivity by more than 90% at an early step of the viral life cycle, most likely the entry step. This inhibition was not observed with other members of the Flaviviridae family tested. The antiviral activity of EGCG on HCV entry was confirmed with pseudoparticles expressing HCV envelope glycoproteins E1 and E2 from six different genotypes. In addition, using binding assays at 4°C, we demonstrate that EGCG prevents attachment of the virus to the cell surface, probably by acting directly on the particle. We also show that EGCG has no effect on viral replication and virion secretion. By inhibiting cell-free virus transmission using agarose or neutralizing antibodies, we show that EGCG inhibits HCV cell-to-cell spread. Finally, by successive inoculation of na?ve cells with supernatant of HCV-infected cells in the presence of EGCG, we observed that EGCG leads to undetectable levels of infection after four passages. CONCLUSION: EGCG is a new, interesting anti-HCV molecule that could be used in combination with other direct-acting antivirals. Furthermore, it is a novel tool to further dissect the mechanisms of HCV entry into the hepatocyte.