901
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Vaidyanathan S, Singh G, Sett P, Watt JW, Soni BM, Oo T. Cutaneous adverse reaction to ciprofloxacin precipitated by ingestion of alcohol in a tetraplegic patient. Spinal Cord 1999; 37:663-4. [PMID: 10490860 DOI: 10.1038/sj.sc.3100896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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902
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Abstract
Metallothioneins (MTs) are low-molecular-weight proteins involved in metalloregulatory functions such as cell proliferation, growth, and differentiation. In recent years, MT expression has been linked with carcinogenesis, resistance to cancer therapy, and tumour progression. However, the significance of MT expression in ovarian cancers is at present inadequately documented. In this study, MT immunohistochemistry was performed in 12 benign, 14 borderline, and eight malignant serous tumours of the ovary. The intensity of the immunostaining was evaluated by image analysis. There was a significantly higher number of MT-immunopositive cells in the multilayered epithelial cells of borderline serous tumours (atypical proliferative serous tumours) than in the single layered epithelial cells within the same tumour, and in the single cell layer of benign serous tumours. There was no difference in the expression of MTs in the single layered tumour cells of benign and borderline serous tumours. Significantly higher numbers of MT-immunopositive cells were observed in both the single and the multilayered epithelial cells of serous carcinomas, the highest number being observed in the multiple layers of serous carcinomas. The positively stained malignant tumour cells in both single and multiple layers were larger than the negatively stained cells in benign, borderline, and malignant serous ovarian tumours. There was moderate to intense staining. These findings indicate that there is increased expression of MTs in the progression of malignancy, which could be used as a marker in grading the three groups of ovarian serous tumours and for determining prognosis.
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903
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Abstract
Previous studies have shown that rapid cell proliferation is associated with elevated glucose consumption. However, those studies did not establish whether glucose is required for prostate cancer cell proliferation or define the molecular mechanisms by which glucose regulates cell division. We addressed these issues by studying two metastatic human prostate cancer cell lines: DU145, which is androgen independent and highly proliferative; and LNCaP, which is androgen dependent and relatively slow growing. We found that proliferation of DU145 cells was significantly inhibited by reduction of glucose in the medium to 0.5 g/L, which is half the physiologic concentration, whereas LNCaP cells grew at control rates even in the presence of only 0.05 g/L glucose. Glucose deprivation of DU145 cells caused a 90% reduction in DNA synthesis; a 10-20-fold reduction in cyclins D and E and CDK4 levels; and cell cycle arrest in G0-G1. However, glucose deprivation did not cause global inhibition of protein synthesis, since mutant p53 levels increased in glucose-deprived DU145 cells. This observed increase in mutant p53 levels was not associated with a rise in p21 levels. Glucose deprivation of DU145 cells also led to apparent dephosphorylation of mutant retinoblastoma (RB) protein. We conclude that: 1) high levels of glucose consumption are required for rapid proliferation of androgen-independent prostate cancer cells, 2) glucose may not be required for slow growth of androgen-dependent prostate cancer cells, and 3) glucose promotes passage of cells through early G1 by increasing the expression of several key cell cycle regulatory proteins that normally inhibit RB function.
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904
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Vaidyanathan S, Parsons KF, Krishnan KR, Soni BM, Singh G, Sett P. What is the optimum fluid intake in male patients with spinal cord injury and neuropathic bladder? Spinal Cord 1999; 37:594-5. [PMID: 10455538 DOI: 10.1038/sj.sc.3100882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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905
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Caney C, Bulmer JT, Singh G, Lukka H, Rainbow AJ. Pre-exposure of human squamous carcinoma cells to low-doses of gamma-rays leads to an increased resistance to subsequent low-dose cisplatin treatment. Int J Radiat Biol 1999; 75:963-72. [PMID: 10465362 DOI: 10.1080/095530099139728] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate low-dose hypersensitivity to cisplatin and increased resistance at higher doses of cisplatin for the human squamous carcinoma cell line SCC-25 and its cisplatin-resistant derivative SCC-25/CP, and to examine the effects of pre- and post-treatment of SCC-25 cells with low-doses of gamma-rays on their resistance to cisplatin. MATERIALS AND METHODS SCC-25 and SCC-25/CP cells were treated with various cisplatin concentrations (0.1 to 20 microM for 1 h) and assayed for survival using a conventional colony assay. For SCC-25, various doses of gamma-rays (5 cGy to 2.5 Gy) were given either 10 or 60 min before the cisplatin challenge dose as well as either 10 or 60 min after the cisplatin challenge dose. RESULTS Low-dose (0.5, 0.75 and 1 microM for 1 h) hypersensitivity to cisplatin and increased resistance at higher doses was detected for the SCC-25 cell line, but not for its cisplatin-resistant derivative, SCC-25/CP. Pretreatment of SCC-25 cells with an acute low-dose of 5, 25 cGy or 1 Gy gamma-rays given 60 min before a low-dose cisplatin challenge (0.1 and 1 microM for 1 h) resulted in a significant increase in resistance (p=0.2, 0.01 and <0.001 respectively). For pretreatment of SCC-25 cells with similar low-doses of gamma-rays 10 min before the challenge cisplatin dose, the increased resistance was reduced or absent and was only significantly increased for pretreatment with 25 cGy and a challenge cisplatin dose of 0.1 microM for 1 h (p = 0.02). Similar acute low-doses of y-rays given either 10 or 60 min after the challenge cisplatin dose did not increase resistance. CONCLUSIONS The human squamous carcinoma cell line SCC-25 showed a low-dose hypersensitivity to cisplatin followed by increased resistance at higher doses. Treatment of SCC-25 cells with low-doses of gamma-rays can induce a protective effect to a subsequent low-dose cisplatin challenge.
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906
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Singh P, Singh G, Luthra D, Kotwal S, Singh H. A rare long standing foreign body in the larynx. Indian J Otolaryngol Head Neck Surg 1999; 51:31-3. [PMID: 23119591 PMCID: PMC3451025 DOI: 10.1007/bf03001549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
An accidentally inhaled foreign body (A metallic toe ring) inside the larynx of a 2 1/2 year old child has been studied. It remained in the larynx for 8 months before detection and removal.
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907
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Singh G, Prabhu S. Leprosy presenting as macrocheilia. INDIAN JOURNAL OF LEPROSY 1999; 71:341-2. [PMID: 10626241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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908
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Singh G, Prabhu S, Mohan M. Hyperreflexia in leprosy. INDIAN JOURNAL OF LEPROSY 1999; 71:342-3. [PMID: 10626242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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909
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Sweet S, Singh G. Changes in mitochondrial mass, membrane potential, and cellular adenosine triphosphate content during the cell cycle of human leukemic (HL-60) cells. J Cell Physiol 1999; 180:91-6. [PMID: 10362021 DOI: 10.1002/(sici)1097-4652(199907)180:1<91::aid-jcp10>3.0.co;2-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Oxidative phosphorylation within the inner mitochondrial membrane generates the majority of cellular adenosine triphosphate (ATP) required for normal physiological functions (including regulation of cell volume and solute concentration, maintenance of cellular architecture, and synthesis of essential macromolecules). Its efficient functioning depends on the maintenance of an electrochemical gradient and is tightly coupled to the energetic demands of the cell and/or tissue. Commitment to and completion of the cell division cycle are sensitive to changes in the availability of mitochondrially derived ATP, although the relationship between cell cycle and mitochondrial physiology is poorly understood. Using vital, mitochondrial-specific fluorochromes to differentiate between mitochondrial mass (10-N-nonyl acridine orange) and mitochondrial membrane potential (Rhodamine 123), together with a quantification of total cellular ATP levels, it was possible to generate profiles of these mitochondrial characteristics in HL-60 cells at different stages of their cell cycle. The data suggest that the availability of ATP changes in a cell cycle-specific manner and cannot be predicted by changes in mitochondrial mass or membrane potential. Furthermore, transition points in the cell cycle where ATP availability is low with respect to the amount of functional inner mitochondrial membrane have been observed. We suggest that these cell cycle phase transitions are sensitive to inhibition of mitochondrial activity because the basal levels of available ATP at these points are nearer to a theoretical "minimal threshold" below which cell cycle progression is inhibited.
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910
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911
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Morotti RA, Cangiarella J, Gutierrez MC, Jagirdar J, Askin F, Singh G, Profitt SA, Wert SE, Whitsett JA, Greco MA. Congenital cystic adenomatoid malformation of the lung (CCAM): evaluation of the cellular components. Hum Pathol 1999; 30:618-25. [PMID: 10374767 DOI: 10.1016/s0046-8177(99)90084-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Congenital cystic adenomatoid malformation of the lung (CCAM) is a rare congenital lesion whose pathogenesis is not well defined. It is generally accepted that the various types of CCAMs originate at different levels of the tracheobronchial tree. To further define the pathogenesis of CCAM, we evaluated the cellular composition of different CCAM types by immunohistochemistry. Twenty-two CCAMs (17 CCAM type 1, two type 2, one type 3, and two type 4) were collected. The cellular composition was determined using immunohistochemical stains for type I cell-associated antigen (T1 cell-Ag), surfactant proteins and surfactant protein precursors (SP-A, SP-B, proSP-B, and proSP-C), neuroendocrine cells (GRP), Clara cells (UP-1), and the adhesion molecule CD44v6, a glycoprotein thought to be involved in cell-matrix and cell-cell interactions. Eleven fetal lungs also were analyzed to compare cytodifferentiation of the epithelial-lined cysts of the different types of CCAM with the stages of normal lung development. Our results indicate that CCAM is caused by an arrest in lung development, and, on the basis of cytodifferentiation, two major subtypes can be distinguished. One subtype consisting of CCAM types 1, 2, and 3 that shows a bronchiolar type of epithelium and a second subtype, consisting of CCAM type 4, that has an acinar-alveolar type of epithelium. Our findings also suggest that these two subtypes may arise at different stages of the branching of the bronchopulmonary tree, the first at the pseudoglandular stage and the second at the saccular stage.
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912
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Yamaguchi T, Yamada T, Okutani R, Shijubo N, Singh G, Itoh Y. Characterization of monoclonal antibodies to human protein 1/Clara cell 10 kilodalton protein. Clin Chem Lab Med 1999; 37:631-7. [PMID: 10475070 DOI: 10.1515/cclm.1999.098] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Human protein 1/Clara cell Mr 10,000 protein consists of two identical subunits of seventy amino acid residues each. In the present study, eight clones of monoclonal antibodies against native protein 1 were prepared and their respective epitopes were immunochemically and immunohistochemically characterized using native protein 1, truncated recombinant protein 1 and synthesized peptides. Among the clones, three designated as TY-5, TY-7 and TY-8 recognized amino acid residues 7-16, residues 19-28, and residues 39-46, respectively, all of which comprise the hydrophobic cavity of protein 1, possibly associated with chemical binding function. With the exception of TY-4, the remaining clones recognized residues 61-68 which are exposed to solvent. The epitope of TY-4 remains undetermined. Proper selection and combination of clones and recombinant protein 1 may be useful for fundamental and clinical studies of protein 1.
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913
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Gupta PP, Singh G, Sodhi S, Sood N. Sequential clinical, haematological, biochemical, immunopathological and histopathological alterations in buffalo calves (Bubalus bubalis) intravenously infected with Absidia corymbifera. Trop Anim Health Prod 1999; 31:143-60. [PMID: 10445250 DOI: 10.1023/a:1005165429270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Absidiosis was produced experimentally in 18 buffalo calves by intravenous inoculation of spores of Absidia corymbifera. Infected animals exhibited dullness, depression, partial anorexia and an initial pyrexia and coughing during the first week and two animals died on each of 9, 13 and 16 days post infection (DPI). The haemoglobin concentration and total erythrocyte count showed no appreciable change from their basal values at any stage of the experiment. However, the erythrocyte sedimentation rate and total leukocyte count increased significantly in the infected animals. The differential leukocyte count revealed a relative neutrophilia from 5 to 20 DPI. There was a significant increase in the serum total proteins, blood urea nitrogen, creatinine, alanine aminotransferase, aspartate aminotransferase, serum alkaline phosphatase, total immunoglobulins and circulating immune complexes in the infected animals as compared to the controls. In the sera of the infected animals, specific Absidia corymbifera IgM and IgG antibodies were detected from 3 DPI to 6 DPI respectively by Dot-EIA. Type I and type III skin hypersensitivity were detected from 10 DPI and type IV hypersensitivity from 15 DPI onwards. The gross and microscopic pathological lesions were seen mainly in the lungs, in all except one of the affected animals. This animal died 9 DPI and mycotic granulomas were also seen in its heart and kidneys. The microscopic lesions in the lung took the form of well-developed granulomas.
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914
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Singh G, Thomas D. The Female Tetraplegic: An Admission of Urological Failure. J Urol 1999. [DOI: 10.1016/s0022-5347(05)68901-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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915
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Singh G, Arora V, Fenn PT, Mets B, Blair IA. A validated stable isotope dilution liquid chromatography tandem mass spectrometry assay for the trace analysis of cocaine and its major metabolites in plasma. Anal Chem 1999; 71:2021-7. [PMID: 10361501 DOI: 10.1021/ac981060e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A validated method has been developed for the simultaneous quantitation of cocaine and its major metabolites (ecgonine methyl ester, benzoylecgonine, and norcocaine) in rat plasma. The method is based upon the use of stable isotope dilution liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Previously reported methods do not have the sensitivity and specificity that can be attained with this method. Plasma samples required no cleanup apart from protein precipitation, and no derivatization was required. Selected reaction monitoring was performed on the transitions of m/z 200 to m/z 182 (ecgonine methyl ester), m/z 290 to m/z 168 (benzoylecgonine), m/z 304 to m/z 182 (cocaine), and m/z 290 to m/z 168 (norcocaine). The standard curves were linear over the range from 2 ng/mL (benzoylecgonine, cocaine, and norcocaine) or 5 ng/mL (ecgonine methyl ester) to 1000 ng/mL in rat plasma. The lower limit of quantitation (LLQ) for benzoylecgonine, cocaine, and norcocaine was 2 ng/mL, and for ecgonine methyl ester, the LLQ was 5 ng/mL for plasma. This simple, rapid, reliable, and sensitive method of quantitation had excellent accuracy and precision for the four analytes. The method was sensitive enough to permit a detailed study of the pharmacokinetics of cocaine and its metabolites after administration of a bolus intravenous dose to rats.
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916
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Singh G, Prabhu S, Mohan M. Peyronies disease, scleroderma and diabetes mellitus. Indian J Dermatol Venereol Leprol 1999; 65:152. [PMID: 20921643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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917
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Saxena AK, Singh G. Cyclophosphamide modulates gene expression in neonatal rat testis following antenatal exposure to fetuses during testicular differentiation. ARCHIVES OF ANDROLOGY 1999; 42:205-10. [PMID: 10407652 DOI: 10.1080/014850199262878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The present study was designed to evaluate the altered gene expression in neonatal rat testis after antenatal exposure of cyclophosphamide (one time single dose of either 2, 10, or 20 mg/kg body weight) to the developing fetuses, especially at the time of male sex differentiation. The rationale behind these experiments is to know about the involvement of Y-chromosome gene-dependent product(s) associated with gonadal dysfunction. Using SDS-polyacrylamide gel electrophoresis and photosensitive silver staining technique, the study shows that the variety of proteins of different molecular weight ranges 40,000 to 127,000 Da are modulated by cyclophosphamide exposure to the developing testis. Interestingly, the overexpression of one protein of 74,500 Da was observed both in supernatant as well as in pallet fractions. The qualitative and quantitative regulation of newly synthesized protein appearance or disappearance is observed in a dose-dependent manner.
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918
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Singh G, Kaushal V, Ram S, Kaushal RK, Dhanuka AK, Khurana S. Cysticercus immunoblot assay in patients with single, small enhancing lesions and multilesional neurocysticercosis. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 1999; 47:476-9. [PMID: 10778553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
A single, small (< 20 mm), ring or disc shaped contrast enhancing lesion located at the cortical-subcortical junction with minimal or no surrounding edema on computed tomography is the commonest mode of presentation of neurocysticercosis in the Indian subcontinent. Serum samples of 37 patients with these single, small enhancing lesions (SSEL's) and five patients with typical multilesional parenchymal neurocysticercosis were tested by the electro-immunoblot transfer (EITB) assay and the enzyme linked immunosorbent assay (ELISA). EITB was positive in 18 patients (48.64%) and ELISA was positive in 21 patients (56.76%) with SSEL's. On the other hand EITB was positive in all five patients (100%) and ELISA was positive in four patients (80%) with multilesional neurocysticercosis. The low sensitivity of the EITB in the SSEL's is probably linked to an insufficient immune stimulation provided by a single cysticercus cyst.
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919
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Vaidyanathan S, Singh G, Sett P, Soni BM. Bladder stones of unusual shape in a male with paraplegia due to spinal cord injury who has been performing self-catheterisation. Spinal Cord 1999; 37:375-6. [PMID: 10369177 DOI: 10.1038/sj.sc.3100820] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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920
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Newman LA, Kuerer HM, Hunt KK, Singh G, Ames FC, Feig BW, Ross MI, Taylor S, Singletary SE. Local recurrence and survival among black women with early-stage breast cancer treated with breast-conservation therapy or mastectomy. Ann Surg Oncol 1999; 6:241-8. [PMID: 10340882 DOI: 10.1007/s10434-999-0241-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BACKGROUND Black women with breast cancer have significantly worse survival rates and receive diagnoses at relatively younger ages, compared with white patients with breast cancer, in the United States. Young age at diagnosis has been associated with increased risk for local recurrence (LR) after breast-conservation therapy (BCT). The goal of this study was to evaluate the impact of age and BCT on LR and survival rates among black patients with breast cancer. METHODS The records for 363 black women treated for breast cancer (excluding stage IV disease) at a comprehensive cancer center were reviewed. RESULTS Fifty-eight percent of patients (n = 211) had tumors < or = 5 cm in diameter. Forty-two of these patients (19.9%) received BCT; the LR rate for this group was 9.8%. A total of 168 patients (79.6%) underwent mastectomy; the LR rate for this group was 8.9%. Data on the primary operation were unavailable for one patient. Five-year disease-free survival rates were similar for patients treated with BCT and those treated with mastectomy (88% and 73%, respectively). LR was associated with significant decreases in 5-year overall survival rates for both the BCT group (67% vs. 95%, P < .01) and the mastectomy group (43% vs. 76%, P < .01). LR and 5-year disease-specific survival rates were similar for patients <50 years of age and patients > or = 50 years of age, regardless of treatment. CONCLUSIONS LR and survival rates are not compromised by the use of BCT among black American patients. LR is associated with an increased risk of breast cancer death, regardless of treatment type. Younger age at diagnosis was not associated with an increased rate of LR after BCT in this series.
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921
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Singh G, Triadafilopoulos G. Epidemiology of NSAID induced gastrointestinal complications. J Rheumatol Suppl 1999; 56:18-24. [PMID: 10225536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Nonsteroidal antiinflammatory drugs (NSAID) are one of the most commonly used classes of medications worldwide. It is estimated that more than 30 million people take NSAID daily. Gastrointestinal (GI) complications related to NSAID therapy are the most prevalent category of adverse drug reactions. Patients with arthritis are among the most frequent users of NSAID and are therefore particularly at risk for these side effects. To evaluate the nature of NSAID-related GI complications and to determine how their frequency can be reduced, a series of studies of such complications in patients with rheumatic disease have been carried out based on data from the Arthritis, Rheumatism, and Aging Medical Information System (ARAMIS). This report briefly reviews the literature and presents recent findings from the ARAMIS studies, which provide an update on published information. It addresses whether GI side effects such as dyspepsia can serve as warning symptoms for life-threatening GI complications and describes the risk factors for these events. It also summarizes a study that investigated whether H2-receptor antagonists and antacids affect the development of serious GI complications. In addition, ongoing research and topics to be addressed in future studies are described.
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922
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Adams K, Rainbow AJ, Wilson BC, Singh G. In vivo resistance to photofrin-mediated photodynamic therapy in radiation-induced fibrosarcoma cells resistant to in vitro Photofrin-mediated photodynamic therapy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1999; 49:136-41. [PMID: 10392463 DOI: 10.1016/s1011-1344(99)00047-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The effects of Photofrin-mediated photodynamic therapy (PDT) on the in vitro cell survival and in vivo tumor growth of murine radiation-induced fibrosarcoma (RIF) cell tumors have been examined following in vivo PDT treatment of tumors. The response to in vivo PDT is examined in tumors derived from RIF-1 mouse fibrosarcoma cells and in tumors derived from RIF-8A cells, which show in vitro resistance to PDT. A significant reduction in tumor volume is observed over the first three days following in vivo PDT treatment of either 5 or 10 mg/ kg. The reduction in tumor volume is greater for a 10 compared to a 5 mg/ml dose and occurs to a similar extent for both RIF-1 and RIF-8A tumors. The re-growth is significantly delayed for RIF-1 compared to RIF-8A tumors, indicating a greater response for RIF-1 tumors compared to RIF-8A tumors following PDT. A reduced response of the RIF-8A compared to the RIF-1 tumor cells is also observed in the clonogenic survival of cells from tumors that were excised and explanted in vitro immediately following in vivo PDT treatment. These data indicate that the intrinsic cell sensitivity to PDT is an important component in the mechanism that leads to tumor response following in vivo photodynamic therapy.
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923
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Schreiber M, Muller WJ, Singh G, Graham FL. Comparison of the effectiveness of adenovirus vectors expressing cyclin kinase inhibitors p16INK4A, p18INK4C, p19INK4D, p21(WAF1/CIP1) and p27KIP1 in inducing cell cycle arrest, apoptosis and inhibition of tumorigenicity. Oncogene 1999; 18:1663-76. [PMID: 10208428 DOI: 10.1038/sj.onc.1202466] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cell cycle regulatory proteins are important candidates for therapeutic tumour suppressors. Adenovirus vectors were constructed to overexpress cyclin kinase inhibitors p16INK4A, p18INK4C, p19INK4D, p21(WAF1/CIP1) and p27KIP1 under the control of the murine cytomegalovirus immediate early gene promoter. These vectors directed the efficient expression of each of the cyclin kinase inhibitors and induced growth arrest, inhibited DNA synthesis, and prevented phosphorylation of the retinoblastoma protein (pRb) in cell lines expressing functional pRb. In pRb-deficient cells, expression of the cyclin kinase inhibitors was not effective in inhibiting DNA replication or growth arrest. Interestingly, three of the cyclin kinase inhibitors, p16, p18 and p27 were found to induce apoptotic death in transduced HeLa and A549 cells. When the vectors were tested for their ability to inhibit tumorigenicity in a polyomavirus middle T antigen model of murine breast carcinoma, expression of the cyclin kinase inhibitors resulted in a delay in tumour formation that varied from several weeks for the p19 expressing vector to greater than 25 weeks for the p27 expressing vector. When tumours were injected directly with the adenovirus vectors expressing the cyclin kinase inhibitors, only treatment with the vector expressing p16 resulted in a delay in tumour growth.
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924
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Moorehead RA, Singh G. Mitochondrial membrane potential regulation is independent of c-fos expression. Can J Physiol Pharmacol 1999; 77:195-203. [PMID: 10535693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Tumour cells contain mitochondria with elevated membrane potentials compared with normal cells, and thus this feature provides a selective target for destroying tumour cells. To improve mitochondrial-based therapies, a better understanding of the factors involved in regulating mitochondria are required. Since v-fos overexpression has been shown to elevate mitochondrial membrane potentials in rat fibroblasts, we investigated whether the human homologue, c-fos, was also capable of regulating the mitochondrial membrane potential in cells. Rat fibroblasts transfected with the c-fos gene did not accumulate more rhodamine 123 (Rh123) nor did they retain this Rh123 for extended periods of time compared with their parental line. Moreover, there was no difference in survival following dequalinium chloride (Deca) treatment between transfectants and controls. Similarly, reduction of c-fos expression in rat fibroblasts did not significantly alter their mitochondrial membrane potential. In addition, human ovarian carcinoma cells, which overexpress the c-fos gene, did not accumulate more Rh123 nor were they hypersensitive to Deca compared with their parental line. In another human ovarian carcinoma cell line, selection of variants with lower mitochondrial membrane potential did not alter c-fos mRNA or protein levels. These data suggest that alterations in c-fos expression do not regulate the magnitude of the mitochondrial membrane potential.
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925
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Singh G, Bhatia RS, Khurana D, Khurana SB. Reappearing CT lesions: 4 cases. Neurol India 1999; 47:47-50. [PMID: 10339708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
An overwhelming majority of disappearing CT lesions in India have been aetiologically linked to cysticercosis. We report 4 patients with disappearing CT lesions in whom the lesion later reappeared at the same (3 patients) or different site (1 patient). One patient was a Taenia carrier. Serial MRI evaluation in one patient revealed a persisting lesion in the interval period. The contribution of these observations towards the understanding of the aetiology of disappearing CT lesions is discussed.
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