Semyon A. Risin

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Weightlessness or microgravity of spaceflight induces bone loss due in part to decreased bone formation by unknown mechanisms. Due to difficulty in performing experiments in space, several ground-based simulators such as the Rotating Wall Vessel (RWV) and Random Positioning Machine (RPM) have become critical venues to continue studying space biology.(More)
The purpose of this study was to determine whether production of liver metastasis by human colon carcinoma (HCC) cells depends on the response of tumor cells to organ-derived growth factors. HCC cells were isolated from several surgical specimens whose malignant potential differed (Dukes' stage B or D tumors), adapted to grow in culture, and assessed for(More)
Clinical management of ductal carcinoma in situ (DCIS) remains a challenge because significant proportions of patients experience recurrence after conservative surgical treatment. Unfortunately, it is difficult to prospectively identify, using objective criteria, patients who are at high risk of recurrence and might benefit from additional treatment. We(More)
Studies conducted in real Space and in ground-based microgravity analog systems (MAS) have demonstrated changes in numerous lymphocyte functions. In this investigation we explored whether the observed functional changes in lymphocytes in MAS are associated with changes in gene expression. NASA-developed Rotating Wall Vessel (RWV) bioreactor was utilized as(More)
Postprimary tuberculosis occurs in immunocompetent people infected with Mycobacterium tuberculosis. It is restricted to the lung and accounts for 80% of cases and nearly 100% of transmission. Little is known about the immunopathology of postprimary tuberculosis due to limited availability of specimens. Tissues from 30 autopsy cases of pulmonary tuberculosis(More)
Programmed cell death is an inherent characteristic of all somatic cells, including some immortalized cell lines. Cell death by apoptosis is attributed to nuclear disintegration, chromatin condensation, DNA fragmentation and cytoplasmic boiling. The purpose of this communication is to provide another cytogenetic marker of extensive telomeric associations(More)
We have previously reported the isolation of the cytotoxic factors, tumor necrosis factor-alpha (TNF-alpha), from monocytes and lymphotoxin or TNF-beta, from an established human B lymphoblastoid cell line. In the current study, we examined the production of cytotoxic factors by primary lymphoid cells derived from patients with different malignancies and(More)
The fusion of mouse and human melanoma cells that were tumorigenic but had different metastatic capabilities resulted in hybrids that were metastatic when injected intravenously or subcutaneously into nude mice, regardless of whether it was the mouse or the human melanoma clone that was metastatic. The H7 hybrid line, formed by fusing murine nonmetastatic(More)
Grapefruit juice increases bioavailability of a number of drugs because of inhibition of the P-glycoprotein pump and inhibition of intestinal cytochrome P450 3A4 enzyme. However, interaction between acetaminophen (also known as paracetamol in many parts of the world) and grapefruit juice has never been reported. The interaction of grapefruit juice with(More)
Several studies have shown an association between high nuclear grade or necrosis of ductal carcinoma in situ (DCIS) lesions and the risk of local disease recurrence in patients with DCIS treated surgically with less than mastectomy. Although criteria for separating low from high nuclear grade lesions have been published, no information exists regarding(More)