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Biomedical subjects

P Shrivastava

Publications and source records attributed to P Shrivastava.

8 recordsLinked to original sources
PubMed2003

Effect of thymosin-alpha1 on the production of nitric oxide by tumor-associated macrophages.

The present investigation was conducted to study the effect of thymic peptide: thymosinalpha1 (thyalpha1) on the activation of tumor associated mphi (TAM) obtained from mice bearing a transplantable T cell lymphoma of spontaneous origin designated as Dalton's lymphoma, to produce nitric oxide (NO). It was found that in vivo administration of aqueous thymic extract obtained from thymus of normal mice or thyalpha1 could activate the TAM to produce enhanced amount of NO which was further augmented on in vivo treatment of these TAM by LPS. These observations suggest that thyalpha1 could prime TAM for activation by second signal of LPS. The study also presents evidence that tumor cell elaborate factors that enhance the effect of thyalpha1 on TAM for production of NO. This is the first study to show that thyalpha1 can activate TAM directly even in the absence of LPS, and may, therefore, have clinical significance.

Animals↗
PubMed2001

Management of colonic perforation during percutaneous nephrolithotomy in horseshoe kidney.

Few cases of colonic injury during percutaneous nephrolithotomy (PCNL) have been reported in orthotopic kidneys and none in horseshoe kidney, and the management protocol has not been standardized. A plain film on postoperative day 1 following PCNL showed contrast medium in the descending colon, leading to the diagnosis of colonic injury in a 53-year-old male patient with horseshoe kidney and multiple bilateral stones. He was asymptomatic and was treated successfully by minimally invasive techniques. An asymptomatic patient with a colonic injury following PCNL can be treated by minimal manipulations. Computed tomography imaging is necessary prior to percutaneous surgery on a horseshoe kidney.

Colon↗
PubMed2000

Anticancer drug-induced apoptosis in human monocytic leukemic cell line U937 requires activation of endonuclease(s).

Anticancer agents effect tumor cell killing both in vivo and in vitro through the induction of apoptosis. Endonuclease-mediated internucleosomal DNA fragmentation, the most widely used biochemical marker of apoptosis, has been shown to play a central role in apoptosis in many experimental systems. In the present investigation, we report that activation of endonuclease(s) leading to oligonucleosomal DNA fragmentation is common and an essential event in apoptosis, induced by different anticancer drugs, adriamycin, etoposide and cisplatin. The endonuclease inhibitors aurintricarboxylic acid and zinc ion prevented apoptotic cell death in human monocytic leukemic cell line U937, as documented by DNA fragmentation, morphological and nuclear alterations, and cell viability assay. Additional studies suggest endonuclease(s)-mediated DNA fragmentation may not play a central role in apoptosis in the same cell line in response to other inducers such as heat shock and cells may undergo cell death showing all morphological features of apoptosis even in the absence of DNA fragmentation.

Antineoplastic Agents↗
PubMed1998

Circumvention of multidrug resistance by a quinoline derivative, MS-209, in multidrug-resistant human small-cell lung cancer cells and its synergistic interaction with cyclosporin A or verapamil.

PURPOSE AND METHODS: To develop a clinically useful approach to circumvent P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) in MDR human small-cell lung cancer (SCLC), we examined the ability of a novel quinoline compound, MS-209, to reverse MDR by inhibition of P-gp function in combination with other MDR-reversing drugs using a cytotoxicity assay. RESULTS: We established MDR human SCLC cells by culture in medium with gradually increasing concentrations of adriamycin (ADM). Compared with the parental human SCLC cells, SBC-3, the MDR variant SBC-3 cells obtained (SBC-3/ADM) were highly resistant to various chemotherapeutic agents due to P-gp expression. MS-209 reversed the resistance to ADM and vincristine (VCR) of SBC-3/ADM and H69/VP cells in a dose-dependent manner. Moreover, MS-209 in combination with cyclosporin A (CsA) or verapamil (VER) synergistically enhanced the antitumor effects of ADM and VCR on SBC-3/ADM cells. MS-209 restored ADM incorporation and this effect was enhanced by CsA and VER, suggesting that these synergistic effects were due to competitive inhibition of P-gp function. CONCLUSION: MS-209 in combination with CsA or VER might increase the efficacy of these chemotherapeutic agents against MDR human SCLC cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

Hyperthermia quality assurance guidelines.

These Hyperthermia Quality Assurance guidelines are a result of a joint workshop of the Hyperthermia Committee of the American College of Radiology and the Hyperthermia Physics Center, which is the national quality assurance program under Contract No. N01-CM-37512 with the National Cancer Institute. Hyperthermia technology presently lacks the kind of standardization in equipment, treatment procedures, patient monitoring, and treatment documentation available in radiotherapy. Therefore, preventing unacceptable variability in treatment data demands a strong commitment to in-house quality control procedures and to centralized quality assurance reviews in cooperative multi-institutional trials. This paper presents a set of test procedures necessary to ensure proper operation of equipment, suggests a frequency for such tests, and also includes guidelines on quality control procedures to be used during treatment to improve the safety, effectiveness, and reproducibility of hyperthermia treatments. A set of forms are presented to indicate the minimum data, albeit incomplete, that must be collected for acceptable documentation of treatment. These guidelines should be valuable not only to the new entrants in the field but also to those participating in multi-institutional cooperative hyperthermia trials. They have been approved by the Hyperthermia Committees of American College of Radiology, American Society for Therapeutic Radiology and Oncology, Radiation Therapy Oncology Group and the American Association of Physicists in Medicine.

Forms and Records Control↗