Implication of alterations in Parkin gene among North Indian patients with colorectal cancer.

BACKGROUND/AIMS: Alterations in Parkin (PRKN) have been described in many cancers; however, the molecular mechanism that contributes to loss of Parkin expression in colorectal cancer (CRC) remains unclear. The aim of this study was to investigate the involvement of PRKN mutation and loss of heterozygosity (LOH) in loss of Parkin expression. To understand the role of PRKN in cancer progression, we also evaluated the association of Parkin expression with clinicopathological parameters in North Indian population. MATERIALS AND METHODS: We studied 219 CRC samples and their adjacent normal tissues (control) obtained from North Indian patients with CRC. The expression of Parkin was analyzed by immunohistochemistry (IHC). PRKN mutations were analyzed by single-stranded conformational polymorphism (SSCP) and sequencing. For loss of heterozygosity (LOH), we employed two intragenic, D6S305 and D6S1599, and one telomeric marker, D6S1008. RESULTS: In our study, we found four novel somatic mutations, namely, C166G, K413N, R420P (exon 4), and V425E (exon 11). Both mutation in Parkin (p = 0.0014) and LOH (p = 0.0140) were significantly associated with loss of Parkin expression. Additionally, Parkin mutations were not associated with the clinicopathological parameters of the patients. Furthermore, both, LOH in Parkin and Parkin expression were significantly correlated with different clinicopathological variables (p<0.05). CONCLUSION: Our results indicate that Parkin expression is not regulated by a single mechanism, but both mutation and LOH contribute to loss of Parkin expression. We also provide evidence of involvement of Parkin in metastasis and cancer progression. We, therefore, suggest Parkin as a potential prognostic marker and warrant further analysis in this direction.

Population levels of Phthiraptera on greylag goose, Anser anser (L.).

OBJECTIVE: The present study was performed to record the mean monthly prevalence, intensity of infestation, sample mean abundance and frequency distribution pattern of one phthirapteran species infesting of A. anseris. METHODS: Ten birds were examined every month. Infested birds were deloused. The bird was placed in a polythene bag containing a wool of cotton soaked in chloroform (head protruded out to allow breathing). After 10 minutes, the bird's feathers were ruffled on a white plastic sheet placed below. The head was examined separately. The louse load was transferred to 70% alcohol and separated stage wise and sex wise. RESULTS: A total of 339 specimens of A. anseris were recovered from 66 infested hosts. Male-female ratio was 1: 1.8. Prevalence of Anaticola anseris was 55% (n=120). The sample mean abundance was 2.38 lice/bird. Variance to mean ratio exceeded unity (10.70). The index of discrepancy (D) was 0.75 and the value of exponent of negative binomial (k) remained 0.334.The observed and expected frequencies did not differ significantly (χ2= 13.33, df= 15, p=0.05). CONCLUSION: The prevalence of A. anseris on Indian greylag goose was high but its intensity remained quite low. The distribution pattern of A. anseris conformed the negative binomial model.The temperature, photoperiod and heat index exhibited significant positive correlations with the prevalence of A. anseris.