Factors in the development of chronic infection foci in the nasopharynx

Antigens were studied of HLA system in always ailing patients presenting with the formed chronic focus of infection in the tonsils. A total of 56 patients with chronic decompensated tonsillitis who were assigned for tonsillectomy by clinical indications were examined together with 53 essentially healthy subjects. Tonsillitis patients revealed HLA-antigens B7, A1, associations A10B7, more frequently than controls, the difference being statistically significant. The data obtained are helpful in identification of risk groups in relation to formation in recurrent respiratory diseases of chronic focal pathology in the nasopharynx.     

The participation of the brain dopamine D1 and D2 receptors in the process of the development of depression induced by social confrontations in mice

Brain D1 and D2 receptors were studied in male mice with repeated experience of social defeats in daily intermale aggressive confrontations inducing development of experimental depression. Groups of animals were studied after 10 (T10 losers) and 20 (T20 losers) days of agonistic confrontations. Mice after 5 days of individual housing were used as a control group. In the experimental groups D1/D2 antagonist cisfluphentixol (0.2 mg/kg) did not affect the communicative behavior in the partition test that estimated behavioral reactivity of a male to another one. Selective D2 antagonist sulpiride (20 mg/kg), however, decreased these reactions in the control group and, in particular, in T10 losers but was ineffective in T20 losers. Both antagonists changed behavior in Porsolt's test of the control mice and, to a greater extent, of T10 losers but failed to change it in T20 losers. Decrease in Bmax in nucleus accumbens and increase in Kd in amygdala were revealed in T20 losers with [3H]-SCH 23390 binding assay. The obtained evidence shows that development of DISC is accompanied by D1 and D2 receptor sensitivity changes. Analysis of data suggests the specific participation of D1 receptors of the mesolimbic dopaminergic system at the stage of developed DISC.     

Essential iris atrophy, pigment dispersion, and glaucoma in DBA/2J mice

PURPOSE: To characterize ocular abnormalities associated with iris atrophy in DBA/2J mice and to determine whether mice of this strain develop elevated intraocular pressure (IOP) and glaucoma. METHODS: Different approaches, including slit-lamp biomicroscopy, ophthalmoscopic examination, ultrasound backscatter microscopy, and histology were used to examine the eyes of DBA/2J mice ranging from 2 to 30 months old. IOP was measured in DBA/2J mice of different ages. RESULTS: DBA/2J mice were found to develop pigment dispersion, iris transillumination, iris atrophy, anterior synechias, and elevated IOP. IOP was elevated in most mice by the age of 9 months. These changes were followed by the death of retinal ganglion cells, optic nerve atrophy, and optic nerve cupping. The prevalence and severity of these lesions increased with age. Optic nerve atrophy and optic nerve cupping was present in the majority of mice by the age of 22 months. CONCLUSIONS: DBA/2J mice develop a progressive form of secondary angle-closure glaucoma that appears to be initiated by iris atrophy and the associated formation of synechias. This mouse strain represents a useful model to evaluate mechanisms of pressure-related ganglion cell death and optic nerve atrophy, and to evaluate strategies for neuroprotection.     

Affinity labelling of the tick-borne encephalitis virus RNA replicase proteins by 4-N-exo-base-substituted photoreactive CTP analogs

4-N-exo-base-substituted photoreactive analogs of CTP were designed and synthesized. Two flavivirus proteins NS5 and NS3 are shown to be labelled after RNA synthesis in the presence of the analogs, irradiation by UV-light (313 nm) and subsequent [alpha-32P]NTP incorporation.     

Hepatitis C and G co-infection: response to interferon therapy and quantitative changes in serum HGV-RNA

Hepatitis G virus (HGV), a positive sense RNA virus, is distantly related to hepatitis C virus (HCV): its genetic organization and identity are consistent with the Flaviviridae family. Coinfection with HGV occurs in 10% to 20% of HCV-infected subjects. These similarities raise two theoretical questions. First, could HGV coinfection play any role in the response of HCV to antiviral therapy and second, would this coinfected population have changes in serum HGV-RNA induced by interferon. To address these questions, 98 patients with documented chronic HCV underwent interferon therapy (3 million units three times a week) for 6 months. Response to therapy was categorized using standard biochemical criteria. Changes in HGV-RNA levels were evaluated before, during, and after interferon therapy by a quantitative branched DNA amplification research-based assay. Eleven of 98 (11%) patients with HCV infection had detectable serum HGV-RNA. There was no difference between the groups (HGV+ vs. HGV-) when baseline alanine aminotransferase (ALT) values, HCV-RNA levels, HCV genotype, histological severity, or other demographic features were analyzed. Interferon response was similar in both groups and HGV was not associated with outcome following therapy. Antiviral therapy appeared to induce a reduction in HGV-RNA load in five of nine patients coinfected with HCV serially tested. In two patients, the fall in serum HGV-RNA correlated with biochemical response, independent of changes in HCV-RNA. These observations indicate that a larger study of an HGV population is required to more clearly define the relationship between HCV and HGV coinfection and their response to antiviral therapy.     

Non-natural aglycones of glycopeptide antibiotics of the vancomycin group. Synthesis and antibacterial activity

A new approach for the modification of the heptapeptide core of glycopeptide antibiotics was proposed based on the replacement of amino acid residues in positions 1 and 3 in teicoplanin aglycone and in position 1 in the eremomycin aglycone. Six novel nonnatural aglycones of the vancomycin type were obtained. Compounds derived from the teicoplanin aglycone exhibited in vitro activity against Gram-positive bacteria, and two of them were also active against the vancomycin-resistant enterococci.     

Response of anterior parietal cortex to different modes of same-site skin stimulation

Response of anterior parietal cortex to different modes of same-site skin stimulation. J. Neurophysiol. 80: 3272-3283, 1998. Intrinsic optical signal (IOS) imaging was used to study responses of the anterior parietal cortical hindlimb region (1 subject) and forelimb region (3 subjects) to repetitive skin stimulation. Subjects were four squirrel monkeys anesthetized with a halothane/nitrous oxide/oxygen gas mixtures. Cutaneous flutter of 25 Hz evoked a reflectance decrease in the sectors of cytoarchitectonic areas 3b and/or 1 that receive input from the stimulated skin site. The intrinsic signal evoked by 25-Hz flutter attained maximal intensity 相似文献   

Regulation of spore-formation in Streptomyces galbus mutants

Some asporogenous strains of Streptomyces galbus recover the capacity to form aerial mycelium and spores when they are grown together with the parent sporulating strain under the conditions of superficial cultivation. The sporulating strain of Str. griseus that produces the A factor, a bioregulator, does not restore sporogenesis in asporogenous variants of Str. galbus, in contrast to Str. griseus. Therefore, Str. galbus must liberate a specific compound which controls spore formation in this species.