Treatment with 16 microM K2Cr2O7 results is a time-dependent loss of the clonogenicity of E. coli cells. Under the same experimental conditions, optical density values do not change significantly, since cells have the ability to replicate but not to septate. In fact, microscopic analysis of samples taken over 240 min of exposure to the toxin has revealed the formation of filaments. The filamentous response appears similar to that generated by mitomycin C.

DNA Damage↗

PubMedDate not supplied

The effect of histidine on the cytotoxicity of hydrogen peroxide in cultured mammalian and bacterial cells.

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Animals↗

PubMedDate not supplied

Synthesis and biological application of a new heterodinucleotide with both anti-HSV and anti-HIV activity.

A new antiviral drug with both anti-HSV and anti-HIV activity was synthesized by coupling Acyclovir and the acyclic nucleoside phosphonate (R)PMPA. The heterodinucleotide ACVpPMPA encapsulated into autologous erythrocytes was added to human macrophages providing an effective in vitro protection from HSV-1 and HIV-1 replication.

Anti-HIV Agents↗

PubMedDate not supplied

Bacteria in biopsies of human hypochlorhydric stomach: a scanning electron microscopy study.

A long-lasting condition of hypochloridria leads to a bacterial growth both in the gastric lumen and biopsies of human stomach. Some of these bacteria are probably involved in gastric carcinogenesis, due to their capacity of nitrosation. This study was carried out on biopsies taken during endoscopy from both gastric antrum and the body of patients with or without hypochloridria. Scanning electron microscopy observation shows that bacteria, other than Helicobacter pylori, found in hypochloridria, can be located not only over but also into and under the mucus layer covering the gastric epithelium. In such areas, mechanical and biochemical damage may occur.

Achlorhydria↗

PubMedDate not supplied

Correlation between endoscopic features of gastric antrum, histology and Helicobacter pylori infection in adults.

BACKGROUND: Helicobacter pylori induces histologic inflammation of mucosa variably correlated to different macroscopic features. Recent studies highlight that the presence of Helicobacter pylori could be assessed on the basis of the macroscopic pattern only, in particular nodularity. The present prospective study has correlated this and other endoscopic features, defined by Sydney classification of gastritis, both to Helicobacter pylori presence and histological patterns. RESULTS: Out of 532 patients, 364 were evaluable. The prevalence of Helicobacter pylori was 51.1% with a different distribution between the endoscopic features. Nodularity showed the highest positive predictive value in detecting the Helicobacter pylori presence (69.9%). The histological findings were: normal 26.9%, non atrophic gastritis 55.2%, atrophic gastritis 17.9%. There was a significant difference between abnormal endoscopic features in detecting the histologic gastritis, with endoscopic atrophy and nodularity showing the highest positive predictive value which reaches 96.7% and 91.8%, respectively. Helicobacter pylori infection and histologic gastritis were also present in 30.9% and 41.8%, respectively, of endoscopically normal subjects. Multivariate analysis has strictly correlated age with all abnormal endoscopic features, metaplasia with endoscopic atrophy, and chronic inflammation (gastritis) with nodularity. CONCLUSIONS: The single endoscopic features are poorly correlated with histologic changes and Helicobacter pylori status. Biopsies are mandatory in all cases. The causes of the different macroscopic findings are not yet fully understood.

Adolescent↗