Protective role of Avena fatua against drug-induced liver toxicity.

The study was conducted to examine the protective potential of ethanol seed extract (ESEt) of Avena fatua (wild oats) against antituberculosis drug (ATD)-induced hepatotoxicity in rats. Four groups of rats (n=6) were used. Of which, three groups were given ATD (Rimstar 900mg/15kg) and divided them into hepatotoxic control (distilled water 1mL/kg), positive control (silymarin 200mg/kg) and test group (ESEt 800mg/kg). The fourth was the normal control group treated only with distilled water (1mL/kg). All treatments were orally administered in their respective groups for 26 days. On the 27thday, rats were decapitated. Body and liver weights were measured whereas serum and liver samples were collected for biochemical and histopathological assessments. The rats treated with silymarin and ESEt showed a significant decrease (p<0.05, 0.01& 0.0001) in liver enzymes including alanine & aspartate transaminases, gamma glutamyltranspeptidase and alkaline phosphatase. ESEt also improved total bilirubin (particularly indirect bilirubin), total protein, albumin and low density lipoprotein cholesterol levels in test group. The hepatoprotective ability of extract was also evident by histological study of liver tissues of the test group that showed normal architecture as compared to liver of ATD treated hepatotoxic control group displayed heterogeneous hepatocytes, inflamed central vein, fatty deposits, enlarged sinusoid, Kupffer's cells infiltration, hypertrophy and fibrosis. In conclusion, ESEt of A.fatua is hepatoprotective in nature which may be due to the presence of total phenols and flavonoids already reported from the seeds of this plant.

Multi-walled carbon nanotube-induced genotoxic, inflammatory and pro-fibrotic responses in mice: Investigating the mechanisms of pulmonary carcinogenesis.

The International Agency for Research on Cancer has classified one type of multi-walled carbon nanotubes (MWCNTs) as possibly carcinogenic to humans. However, the underlying mechanisms of MWCNT- induced carcinogenicity are not known. In this study, the genotoxic, mutagenic, inflammatory, and fibrotic potential of MWCNTs were investigated. Muta™Mouse adult females were exposed to 36±6 or 109±18µg/mouse of Mitsui-7, or 26±2 or 78±5µg/mouse of NM-401, once a week for four consecutive weeks via intratracheal instillations, alongside vehicle-treated controls. Samples were collected 90days following the first exposure for measurement of DNA strand breaks, lacZ mutant frequency, p53 expression, cell proliferation, lung inflammation, histopathology, and changes in global gene expression. Both MWCNT types persisted in lung tissues 90days post-exposure, and induced lung inflammation and fibrosis to similar extents. However, there was no evidence of DNA damage as measured by the comet assay following Mitsui-7 exposure, or increases in lacZ mutant frequency, for either MWCNTs. Increased p53 expression was observed in the fibrotic foci induced by both MWCNTs. Gene expression analysis revealed perturbations of a number of biological processes associated with cancer including cell death, cell proliferation, free radical scavenging, and others in both groups, with the largest response in NM-401-treated mice. The results suggest that if the two MWCNT types were capable of inducing DNA damage, strong adaptive responses mounted against the damage, resulting in efficient and timely elimination of damaged cells through cell death, may have prevented accumulation of DNA damage and mutations at the post-exposure time point investigated in the study. Thus, MWCNT-induced carcinogenesis may involve ongoing low levels of DNA damage in an environment of persisting fibres, chronic inflammation and tissue irritation, and parallel increases or decreases in the expression of genes involved in several pro-carcinogenic pathways.

Chronic atrophic antral gastritis and risk of metaplasia and dysplasia in an area with low prevalence of Helicobacter pylori.

INTRODUCTION: The Northeastern region of Peninsular Malaysia is an area with exceptionally low prevalence for Helicobacter pylori infection. The risk of intestinal metaplasia and dysplasia in patients with chronic atrophic gastritis (CAG) and its association with Helicobacter pylori is unknown in this region. METHODS: This was a cross-sectional study on gastric biopsies from 234 consecutive patients (mean age 53.5 [14.8] years) who underwent upper gastrointestinal endoscopy between January 2006 and December 2006. RESULTS: There were 137 (59%) men and 185 (79%) Malay patients. Among 234 biopsies, CAG was found in 99 and non-atrophic gastritis in 135. Intestinal metaplasia and dysplasia were detected in 8 and 6 atrophic gastritis biopsies, respectively, and in 10 and 3 of non-atrophic gastritis biopsies, respectively. H. pylori were detected in 16 (9 Malays, 7 non- Malays) biopsies (p=0.024); intestinal metaplasia was detected in 4 biopsies (p=0.3) and dysplasia in 5 biopsies (p=0.3). Of the 218 biopsies negative for H. pylori, intestinal metaplasia was found in 14 and dysplasia in 4. The risk of intestinal metaplasia as well as dysplasia was associated with presence of H. pylori infection (p=0.029 and p<0.001 respectively). CONCLUSION: Even in a setting of low prevalence of H. pylori, intestinal metaplasia and dysplasia were significantly associated with H. pylori infection. The frequency of intestinal metaplasia and dysplasia was similar different between biopsies with atrophic gastritis and non-atrophic gastritis.

Prognostic value of proliferating cell nuclear antigen (PCNA) in infiltrating ductal carcinoma breast.

OBJECTIVE: To assess the independent and interdependent prognostic value of proliferating cell nuclear antigen (PCNA) in carcinoma of breast in our female population and its association with pathologic variables and disease outcome. DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: Section of Histopathology, Department of Pathology and Microbiology, The Aga Khan University, Karachi from January 1992 to December 1997. PATIENTS AND METHODS: All cases diagnosed with invasive ductal carcinomas (IDC) of breast with lymph nodes sampling were included. The expression of PCNA was analyzed on tumor specimens of IDC breast. These patients also had axillary lymph node sampling. The expression of PCNA protein was analyzed immunohistochemically by PAP technique. Patients were followed for a median duration of 48 months. RESULTS: The percentage of PCNA positive tumor cells was estimated semi-quantitatively. Positivity was seen in every case, mean PCNA positivity was 27% (range 10-80) with a median of 28%. The <25% positivity was seen in 149 (47%) cases, and >25% positivity seen in 166 (53%) cases. According to the pathological grading lowest mean PCNA was seen in grade-I i.e., 26% tumor cells showed nuclear reactivity to PCNA followed by grade-II 30% and grade-III 33%. PCNA categorical expression was significantly correlated with histological differentiation, (p<0.05) and tumor size (p<0.01). Distant metastases were seen in>25% positive cases (p<0.05). PCNA expression when correlated with overall survival, showed significant correlation between categorical PCNA (p<0.05). At a median follow-up of 48 months, 66% of <25 PCNA positive patients died with an overall survival of 3.16 years and disease-free survival of 2.5 years, among >25% PCNA positive patients 77% died with an overall survival of 2.7 years and a disease-free survival of 2.2 years. CONCLUSION: In this study PCNA proved to be an independent prognostic indicator in predicting disease-free and overall survival in breast carcinoma patients.