Development and evaluation of a phage typing scheme for Vibrio cholerae O139

The scenario of cholera that existed previously changed in 1992 and 1993 with the emergence of toxigenic Vibrio cholerae O139 in India. The genesis of the new serogroup formed the impetus to search for O139 phages in and around the country. A total of five newly isolated phages lytic to V. cholerae O139 strains were used for the development of this phage typing scheme. These phages differed from each other and also differed from the existing O1 phages in their lytic patterns, morphologies, restriction endonuclease digestion profiles, and immunological criteria. With this scheme, 500 V. cholerae O139 strains were evaluated for their phage types, and almost all strains were found to be typeable. The strains clustered into 10 different phage types, of which type 1 (38.2%) was the dominant type, followed by type 2 (22.4%) and type 3 (18%). Additionally, a comparative study of phage types in 1993 and 1994 versus those from 1996 to 1998 for O139 strains showed a higher percentage of phage type 1 (40.5%), followed by type 3 (18.8%) during the period between 1993 and 1994, whereas phage type 2 (32. 1%) was the next major type during the period from 1996 to 1998. This scheme comprising five newly isolated phages would be another useful tool in the study of the epidemiology of cholera caused by V. cholerae O139.     

TP53 polymorphisms in gliomas from Indian patients: Study of codon 72 genotype, rs1642785, rs1800370 and 16 base pair insertion in intron-3

Several single nucleotide polymorphisms of the TP53 gene have been reported, amongst which polymorphism in codon 72 (rs1042522) has received significant attention and shown to be associated with disease susceptibility in different cancer types. However, there are variable reports on this polymorphism in gliomas from worldwide with inconsistent results. In addition, the implications of other polymorphic loci are not much explored in gliomas. Hence, in the present study the TP53 sequence was analyzed for all polymorphism and mutations in a total of 84 gliomas of different types and grades from patients of Indian origin. The complete sequence of all coding exons (2 to 11) and introns 2, 3, 5 and 8 of TP53 gene were studied while for introns 1, 4, 6, 7, 9 and 10, only exon flanking regions could be studied. The polymorphic loci were compared with control population. In addition to the well known codon 72 polymorphism (rs1042522), three other polymorphisms rs1642785, rs1800370 and a 16 base pair insertion in intron-3 were found. At codon 72, our study showed higher Arg/Arg genotype in gliomas compared to normal population (38% versus 13%). The Arg allele frequency in glioma patients was comparatively higher than controls (0.55 versus 0.45; P = 0.037). The Arg allele frequency was also high in adult glioblastomas compared to paediatric counterparts (0.55 versus 0.36). However, there was no significant association of TP53 mutations with any genotype of codon 72. At rs1642785, the G allele frequency was significantly higher in gliomas than in control population (0.55 versus 0.36, P = 0.005). The genotype at a 16 base pair insertion in intron-3 was almost similar in case and control. However, the polymorphism at rs1800370 was exclusive to gliomas. This is the first report of TP53 gene polymorphism in glioma patients from India. Our study also delineates the frequency of four polymorphisms in gliomas for the first time. The codon 72 variant (rs1042522) and rs1642785 polymorphisms possibly poses risk to glioma development in Indian population. However, the functional significance of these polymorphism needs further elucidation.     

Sequence analysis of morbillivirus CD150 receptor-signaling lymphocyte activation molecule (SLAM) of different animal species

Signaling Lymphocyte Activation Molecule-SLAM (CD150) molecule has been reported as a putative receptor for most morbilliviruses for their respective host species. In this study, we determined the complete nucleotide sequence of the gene coding for the morbillivirus receptor-SLAM from the four species, namely, goat (Capra hircus), sheep (Ovis aries), Indian cattle (Bos indicus), and buffalo (Bubalus bubalis). The nucleotide (nt) open reading frame sequence of SLAM gene in all the four species studied was 1017 nucleotides in length encoding a polypeptide of 339 amino acids (aa), similar to Bos taurus, but different from canine, human, marmoset, and mouse SLAM, which were 1029, 1008, 1011, and 1032 nts, respectively, in length, and coding for 343, 336, 337, and 344 aa, respectively. Sequence analysis revealed 96.3–98.5% and 92.9–96.8% identities among the four species at the nt and aa level, respectively. Sequence diversity at aa level between various species revealed that the critical functional region of SLAM protein among different species is relatively conserved, thereby facilitating this molecule to act as a receptor for morbillivirus. Phylogenetic relationship based on the aa sequences of SLAM protein revealed that caprine, ovine, cattle, and buffalo fall under a defined cluster but caprine SLAM is more closely related to ovine, followed by bovine.     

Clonal mutations in primary human glial tumors: evidence in support of the mutator hypothesis

Background  

A verifiable consequence of the mutator hypothesis is that even low grade neoplasms would accumulate a large number of mutations that do not influence the tumor phenotype (clonal mutations). In this study, we have attempted to quantify the number of clonal mutations in primary human gliomas of astrocytic cell origin. These alterations were identified in tumor tissue, microscopically confirmed to have over 70% neoplastic cells.     

Transforming growth factor-beta3 stimulates lactotrope cell growth by increasing basic fibroblast growth factor from folliculo-stellate cells

Recently, we have shown that transforming growth factor-beta3 (TGFbeta3) mediates estradiol's mitogenic action in primary cultures of mixed anterior pituitary cells. In some cell types, TGFbeta isoforms stimulate cell proliferation via a paracrine mechanism by increasing growth stimulatory peptide growth factors. Whether such a mechanism exists in pituitary cell culture was examined in the studies presented here. The data demonstrate that unlike the response of lactotropes in mixed pituitary cultures, cultures of enriched lactotropes, obtained by Percoll gradient separation, did not proliferate in response to TGFbeta3 treatment. The lactotropic cells of the RC-4B/C cell line, a cell line that contains all of the hormone-secreting cell types of the anterior pituitary but is devoid of folliculo-stellate (FS) cells, did not proliferate in response to TGFbeta3 unless RC-4B/C cells were cocultured with FS cells. Enriched lactotropes cocultured with FS cells also demonstrated a proliferative response to TGFbeta3. Media collected from FS cells treated with TGFbeta3 stimulated the proliferation of lactotropes in enriched cultures. TGFbeta3 increased the release of basic fibroblast growth factor from FS cells. Immunoneutralization of basic fibroblast growth factor in FS cell-conditioned medium inhibited the growth stimulatory action on lactotropes. These data provide evidence for a novel mechanism of TGFbeta3 action involving cell-to-cell interaction in the anterior pituitary between lactotropes and FS cells during estrogen-induced mitogenesis.     

Dopamine increases the efficacy of anticancer drugs in breast and colon cancer preclinical models.

PURPOSE: Because neurotransmitter dopamine inhibits vascular permeability factor/vascular endothelial growth factor (VEGF)-induced angiogenesis and as anti-VEGF agents act synergistically with anticancer drugs, we therefore investigated whether dopamine can increase the efficacies of these drugs. EXPERIMENTAL DESIGN: The effect of dopamine was investigated in human breast cancer-(MCF-7) and colon (HT29) cancer-bearing mice. Experimental groups received either dopamine or doxorubicin or dopamine plus doxorubicin in MCF-7 tumor-bearing mice, and either dopamine or 5-fluorouracil or dopamine plus 5-fluorouracil in HT29-bearing mice. Thereafter, tumor growth, angiogenesis, tumor cell apoptosis, life span, and the effect of dopamine on the growth and survival of tumor cells in vitro were determined. Finally, the effects of dopamine on tumor vascular permeability; on VEGF receptor-2, mitogen-activated protein kinase, and focal adhesion kinase phosphorylation; and also on the proliferation and migration of tumor endothelial cells were investigated. RESULTS: Dopamine, in combination with anticancer drugs, significantly inhibited tumor growth and increased the life span when compared with treatment with dopamine or anticancer drugs alone. Dopamine had no direct effects on the growth and survival of tumor cells. The antiangiogenic action of dopamine was mediated by inhibiting proliferation and migration of tumor endothelial cells through suppression of VEGF receptor-2, mitogen-activated protein kinase, and focal adhesion kinase phosphorylation. CONCLUSION: Our study shows that dopamine significantly enhances the efficacies of commonly used anticancer drugs and also indicates that an inexpensive drug like dopamine, which is being extensively used in the clinics, might have a role as an antiangiogenic agent for the treatment of breast and colon cancer.     

Falciparum malaria

We analysed cases of hematologically proved cases ofPlasmodium falciparum malaria encountered from July 1984 to Dec 1985 in a military hospital. The age range was 3 days to 10 years. Majority presented with classical symptom of fever (92.7%). Others presented with gastrointestinal (7.3%), hepatic (4.5%), central nervous system (7.3%) and respiratory (3.6%) symptoms. Anemia was found in 36.4%. Hepatosplenomegaly was present in majority of the cases. The rare findings were polyarthritis, rash, urticaria and cerebellar features. All cases responded to chloroquin or quinine. No resistance to drugs was found and there was no mortality.