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Biomedical subjects

Beena Kumar

Publications and source records attributed to Beena Kumar.

4 recordsLinked to original sources

The wound repair response controls outcome to cutaneous leishmaniasis.

Chronic microbial infections are associated with fibrotic and inflammatory reactions known as granulomas showing similarities to wound-healing and tissue repair processes. We have previously mapped three leishmaniasis susceptibility loci, designated lmr1, -2, and -3, which exert their effect independently of T cell immune responses. Here, we show that the wound repair response is critically important for the rapid cure in murine cutaneous leishmaniasis caused by Leishmania major. Mice congenic for leishmaniasis resistance loci, which cured their lesions more rapidly than their susceptible parents, also expressed differentially genes involved in tissue repair, laid down more ordered collagen fibers, and healed punch biopsy wounds more rapidly. Fibroblast monolayers from these mice repaired in vitro wounds faster, and this process was accelerated by supernatants from infected macrophages. Because these effects are independent of T cell-mediated immunity, we conclude that the rate of wound healing is likely to be an important component of innate immunity involved in resistance to cutaneous leishmaniasis.

Animals↗

Abnormalities of the RB1 pathway in ovarian serous papillary carcinoma as determined by overexpression of the p16(INK4A) protein.

Dysfunction of proteins involved in the G1 to S transition of the cell cycle, such as p16(INK4A) and RB1, is common in many cancer types. A screen of p16 protein expression was performed in benign, borderline, and invasive ovarian tumors, together with endometrial cancers, aligned on a tissue microarray. We observed frequent p16 overexpression in serous papillary carcinomas of ovarian and endometrial origin. An extended cohort of ovarian serous papillary carcinomas was examined to further evaluate the frequency of p16 overexpression. Strong, uniform staining in the majority of cancer cells occurred commonly in invasive serous papillary ovarian cancers, particularly in grade 3 carcinomas. RB1 protein expression abnormalities were rare. Our data indicate that abnormalities in the retinoblastoma pathway, as determined by p16 overexpression, are common in serous papillary carcinomas and are probably an early event.

Adult↗

Tissue microarrays: a practical guide.

Tissue microarrays are a recent innovation in the field of pathology. They were originally designed as a high-throughput approach for researchers to assess the expression of interesting candidate disease-related genes or gene products simultaneously on hundreds of tissue samples. However, their use is becoming more widespread in routine pathology, for example for quality assurance and for the optimisation of diagnostic reagents such as monoclonal antibodies and gene probes. Several molecular and conventional pathological techniques can be performed on a single tissue array, thereby enabling morphology, DNA, RNA and protein targets to be analysed on sequential sections through multiple tissue samples. Moreover, compared with full-face tissue sections, tissue microarrays are a cost- and time-efficient, effective approach to analysing biomarker expression on a large number of samples. Whilst tissue microarrays are available from commercial sources, many pathology laboratories prefer to make in-house arrays from their often extensive pathology archive to facilitate the correlation of their findings with clinical parameters. The technical skills necessary to produce tissue arrays are well within the capacity of most laboratories. However, several pitfalls to successful array production exist. The present article describes the applications of this technique and details practical points for optimal tissue array production.

Gene Expression Profiling↗