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Kolluri V, Mohanty A, Das S, Arya B, Chandramouli BA, Gupta PK, Das BS, Sastry KV. Peritumoural oedema in meningiomas : a radiological and histological correlation. Neurol India 1997; 45:166-169. [PMID: 29512541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
One hundred and six patients with intracranial meningiomas were evaluated retrospectively, and the degree of peritumoural oedema as noticed on CT, was correlated with the histological features and site and size of the tumour. 89 of the tumours which were 4.5 cms or more and all angioblastic and haemangiopericytic subtypes were associated with significant peritumoural oedema.
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Nagarkar MM, Gupta PK. Method for obtaining a symmetric power tuning curve for a single-mode continuous-wave CO(2) laser. APPLIED OPTICS 1997; 36:4099-4101. [PMID: 18253433 DOI: 10.1364/ao.36.004099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We propose and demonstrate a technique for obtaining a symmetric power tuning curve for a single-mode continuous-wave CO(2) laser regardless of the operating power level.
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Chatthai M, Kaukinen KH, Tranbarger TJ, Gupta PK, Misra S. The isolation of a novel metallothionein-related cDNA expressed in somatic and zygotic embryos of Douglas-fir: regulation by ABA, osmoticum, and metal ions. PLANT MOLECULAR BIOLOGY 1997; 34:243-254. [PMID: 9207840 DOI: 10.1023/a:1005839832096] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
To isolate genes which are expressed preferentially during embryogenesis, a Douglas-fir embryogenesis cDNA library was constructed and differentially screened with cDNA probes made with mRNA from developing and mature embryos, respectively. The cDNA clone PM 2.1 was isolated based on its abundance in developing seeds and absence in mature seeds, and its predicted amino acid sequence was shown to have structural features characteristic of plant MT-like proteins. Alignment of the PM 2.1 predicted amino acid sequence with other plant MT-like protein sequences revealed a general paucity of Cys and Cys-Xaa-Cys sequences and the presence of novel serine residues within the conserved Cys-Xaa-Cys motifs in the C-terminal domain. The consensus sequence following the Cys-poor spacer in type 2 MT-like proteins, CXCXXXCXCXXCXCX, was modified in PM 2.1 to CXSXXXSXYXX-XCX. Phylogenetic analysis supported PM 2.1 was distinct from other MT and grouped with MT-like proteins from Arabidopsis (OEST), rice (AEST) and kiwifruit (AD1), which do not belong to type 1 or 2. The PM 2.1 gene was expressed in somatic and zygotic embryos, in haploid maternal tissue, as well as in hormone- and metal-treated seeds and seedlings. The PM 2.1 transcripts were detected in the needles of 14-week-old seedlings, but not the root tissue or mature pollen. The expression of the PM 2.1 gene in embryos was dependent upon ABA and osmoticum and in seedlings was differentially modulated by metals, suggesting a role of the PM 2.1 gene product in the control of microelement availability during Douglas-fir seed development and germination. The novel structural features, and the developmental, hormonal and metal modulation of PM 2.1 expression, are evidence for a new type of MT-related protein in plants.
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279
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Zaman SS, van Hoeven KH, Slott S, Gupta PK. Distinction between bronchioloalveolar carcinoma and hyperplastic pulmonary proliferations: a cytologic and morphometric analysis. Diagn Cytopathol 1997; 16:396-401. [PMID: 9143840 DOI: 10.1002/(sici)1097-0339(199705)16:5<396::aid-dc4>3.0.co;2-a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objectives of this study were to identify key cytologic features for the morphologic differentiation of bronchioloalveolar carcinoma from reactive pulmonary proliferations, and to determine if morphometry of the cytologic specimens could provide additional data to distinguish the two processes. We analyzed 15 morphologic criteria in pulmonary cytologic specimens from 17 histologically proven cases of bronchioloalveolar carcinoma and 13 cases with reactive cellular changes and compared the findings using univariate analysis. This revealed four statistically significant features more commonly associated with bronchioloalveolar carcinoma: (i) predominance of two- and three-dimensional tissue fragments, (ii) tenacious intercytoplasmic connections between cells, (iii) intranuclear cytoplasmic inclusions, and (iv) paucity of multinucleated cellular forms. Morphometric measurement revealed significant differences between the mean of the nuclear area of benign reactive cells and that of the malignant cells. The utilization of these criteria is helpful to diagnose bronchioloalveolar carcinoma and to distinguish it from reactive pulmonary processes.
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280
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Faigel DO, Ginsberg GG, Bentz JS, Gupta PK, Smith DB, Kochman ML. Endoscopic ultrasound-guided real-time fine-needle aspiration biopsy of the pancreas in cancer patients with pancreatic lesions. J Clin Oncol 1997; 15:1439-43. [PMID: 9193337 DOI: 10.1200/jco.1997.15.4.1439] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Endoscopic ultrasound (EUS) is an important new tool in the staging of pancreatic malignancies. Using new curved linear-array instruments, real-time fine-needle aspiration biopsy (RTFNA) of pancreatic lesions can be performed. METHODS Forty-five patients with pancreatic lesions (22 males and 23 females) underwent staging with the Olympus EUM-20 (Olympus America Corp, Melville, NY) followed by EUS-RTFNA with the Pentax FG-32PUA (Pentax-Precision Instrument Corp, Orangeburg, NY) and the 22-gauge GIP needle (GIP Medizin Technik, Grassau, Germany). RESULTS EUS tumor stages were as follows: TO, n = 1; T1, n = 8; T2, n = 9; and T3 n = 27. Aspiration attempts were unsuccessful in four patients (two technical failures and two inadequate specimens). The remaining 41 lesions (mean size, 3.3 cm) were aspirated under EUS guidance (median passes, three) and the cytologic diagnoses were 25 definite adenocarcinoma, five suspicious for adenocarcinoma (three subsequently confirmed and two clinical course consistent with adenocarcinoma), and 11 negative for malignancy. Of 11 negatives, two were found to have adenocarcinoma, seven were confirmed benign at surgery (four cystadenomas and three inflammatory), one had a benign pseudocyst, and one had abundant inflammatory cells on RTFNA and follow-up time greater than 12 months with computed tomographic (CT) scans consistent with resolving inflammation. There were no false-positive RTFNAs. There were no procedure-related complications. Among those with diagnostic EUS-RTFNA (91%), the sensitivity for malignancy (confirmed plus suspicious) was 94% and negative predictive value 82%. CONCLUSION EUS-guided RTFNA is a safe and accurate method for performing pancreatic biopsy. It should be considered in patients with suspected pancreatic malignancies in whom a tissue diagnosis is required or when other modalities have failed. EUS-RTFNA allows for local staging and tissue diagnosis in one procedure.
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281
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Mishra S, Gupta PK. Exchange transfusion in neonates. JOURNAL OF THE INDIAN MEDICAL ASSOCIATION 1997; 95:109-11. [PMID: 9357273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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282
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283
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Gupta PK, Sahota A, Boyadjiev SA, Bye S, Shao C, O'Neill JP, Hunter TC, Albertini RJ, Stambrook PJ, Tischfield JA. High frequency in vivo loss of heterozygosity is primarily a consequence of mitotic recombination. Cancer Res 1997; 57:1188-93. [PMID: 9067291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We have used the adenine phosphoribosyltransferase gene (APRT; 16q24) to investigate the mechanisms of loss of heterozygosity (LOH) in normal human somatic cells in vivo. APRT-deficient (APRT-/-, APRT-/0) T lymphocytes from the peripheral blood of four obligate APRT heterozygotes (APRT+/-) with characterized germ-line mutations were selected in medium containing 100 microM 2,6-diaminopurine. A total of 80 2,6-diaminopurine-resistant T-cell clones from 2 of the heterozygotes were analyzed for this study. The presence or absence of LOH of proximal linked microsatellite repeat markers was used to divide the clones into two groups: (a) those in which LOH was likely due to localized changes in APRT (e.g., point mutations); and (b) those with LOH at additional loci. A total of 61 clones (76%) exhibited LOH of linked microsatellite repeat markers at different locations on 16q, which extended from the smallest measured region (<5.5 cM) to the entire 16q arm. The remaining 19 clones (24%) had point mutations in APRT or other relatively minor alterations. Ten clones with LOH encompassing different regions of 16q were examined by conventional cytogenetics and by fluorescence in situ hybridization using an APRT cosmid probe. All clones exhibited a normal diploid karyotype, and nine exhibited two copies of APRT. The one clone that was hemizygous for APRT had the smallest observed region of LOH in clones from that individual. These results indicate that mitotic recombination and, to a much lesser extent, deletion may be the primary mechanisms for the relatively high frequency of in vivo LOH observed in normal human T cells. Because LOH leads to the expression of recessive tumor suppressor genes in many cancers, these data have significant implications for the role of LOH in the early stages of tumor development, especially in breast cancer.
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Gupta PK, Erozan YS, Schwartz MR. American Society of Cytopathology Laboratory Accreditation Program. Arch Pathol Lab Med 1997; 121:260-3. [PMID: 9111113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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285
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Gupta PK, Shao C, Zhu Y, Sahota A, Tischfield JA. Loss of heterozygosity analysis in a human fibrosarcoma cell line. CYTOGENETICS AND CELL GENETICS 1997; 76:214-8. [PMID: 9186527 DOI: 10.1159/000134552] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Loss of heterozygosity (LOH) is an important event in tumor formation. We have used polymorphic microsatellite repeat markers to identify and characterize LOH in spontaneous mutants of a human cell line, MR12-1, that is heterozygous for the adenine phosphoribosyltransferase gene (APRT+/-) located on chromosome 16q24.3. Initially, clones without extensive LOH (which are likely derived as a consequence of intragenic point mutations) and clones with multilocus LOH (which are likely due to major chromosome alterations) were identified. Clones with major regions of LOH were further characterized by assaying additional informative microsatellite markers. Analysis of 20 spontaneously-arising, independent APRT-/- clones from MR12-1 demonstrated that nine of the mutants retained both copies of APRT and 11 had undergone multilocus genetic alterations. The nature of LOH in four of the latter clones has been examined in detail by karyotype and fluorescence in situ hybridization analysis (Shao et al., 1996). These data demonstrate that LOH of chromosome 16 may be due to mitotic recombination, interstitial or partial deletion, or to more complex mechanisms. LOH in these clones may be a consequence of events similar to those observed in many tumors.
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286
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Trudo FJ, Gopez EV, Gupta PK, Schuster MG, Tino G. Pleural effusion due to herpes simplex type II infection in an immunocompromised host. Am J Respir Crit Care Med 1997; 155:371-3. [PMID: 9001338 DOI: 10.1164/ajrccm.155.1.9001338] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Pleural effusions caused by herpes simplex viruses are rare. We report a case of a young woman with acute lymphocytic leukemia (ALL) and prolonged neutropenia who developed pleural space infection with herpes simplex type II virus (HSV II), as confirmed by cytologic and microbiologic studies. We believe that this is the first report of a pleural effusion caused by HSV II, and suggest that this virus now be considered in the differential diagnosis of an unexplained exudative pleural effusion, especially in an immunocompromised host.
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Abstract
BACKGROUND AND OBJECTIVE This article reports results of an in vitro study involving 63 patients for the evaluation of the diagnostic potential of N2 laser excited autofluorescence spectroscopy of human breast tissues. MATERIALS AND METHODS The N2 laser-excited spectra were recorded from benign (fibroadenomas, 35 patients), cancerous (ductal carcinomas, 28 patients), and normal (the uninvolved areas of the resected cancerous specimens). A stepwise multivariate linear regression (MVLR) analysis was developed to analyze the diagnostic content of the breast tissue fluorescence spectra. RESULTS Significant changes were observed in the autofluorescence from normal, benign, and cancerous breast tissues, particularly in the spectrally integrated fluorescence intensity. The ratio of mean spectrally integrated intensity from cancerous tissues to that from benign tumor and normal tissues were 3.2 and 2.8, respectively. A discrimination parameter based on spectrally integrated intensity alone provided a sensitivity and specificity of up to 99.6% over the sample size investigated for discrimination of cancerous breast tissues from benign/normal. CONCLUSION Our results suggest that a straightforward measurement of the total integrated fluorescence intensity can provide excellent discrimination between cancerous and benign/ normal breast tissues.
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Gupta PK, Mital BK, Garg SK. Antagonistic activity of Lactobacillus acidophilus fermented milk against different pathogenic bacteria. INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY 1996; 34:1245-7. [PMID: 9246920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lactobacillus acidophilus strains tested showed inhibitory activity towards Salmonella typhi, Staphylococcus aureus, Escherichia coli, Proteus vulgaris and Yersinia enterocolitica. However, wide variations in the activity of the strains were observed. Antagonistic activity of the strains exhibited high heat stability (120 min at 92 degrees C, 15 min at 121 degrees C) but it was markedly influenced by changes in pH. Effect of kind of milk on antagonistic activity was variable, whereas skimming had no significant effect.
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Zaman SS, Sack MJ, Ramchandani P, Tomaszewski JE, Gupta PK. Cytopathology of retrograde renal pelvis brush specimens: an analysis of 40 cases with emphasis on collecting duct carcinoma and low-intermediate grade transitional cell carcinoma. Diagn Cytopathol 1996; 15:312-21. [PMID: 8982587 DOI: 10.1002/(sici)1097-0339(199611)15:4<312::aid-dc12>3.0.co;2-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report our experience with 40 retrograde renal brush samples of pelvic-calyceal lesions with confirmatory tissue studies. On-site cytopathologic evaluation was performed in 38 of these specimens. The final histologic diagnoses included 24 cases of transitional cell carcinoma (TCC), 17 of which were low-intermediate grade tumors. All 24 cases were diagnosed cytologically as TCC (22), or as suspicious for TCC (2). Three cases classified as collecting duct carcinomas were resected; the cytologic specimens in 2 of these cases were interpreted as TCC, and one as reactive change. There were three renal cell carcinomas (RCC); cytologically, one was considered a papillary neoplasm, one suspicious for malignancy, and one as reactive. Two cases of atypical renal cysts were reported as suspicious for malignancy in both cytologic and histologic material. There was one case of metastatic colon carcinoma identified in the brush specimen. Finally, tissue studies in the remaining 7 cases showed reactive/inflammatory changes; however, four of the corresponding pelvic brush specimens were considered abnormal. A review of the above cases is reported with the objective of presenting the cytologic features seen in collecting duct carcinoma, low-intermediate grade TCC, and diagnostically difficult cases with cyto/histomorphologic discrepancies. The contribution of on-site assessment to diagnostic accuracy is also discussed.
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291
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Wake MC, Gupta PK, Mikos AG. Fabrication of pliable biodegradable polymer foams to engineer soft tissues. Cell Transplant 1996. [PMID: 8800514 DOI: 10.1016/0963-6897(96)00025-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have fabricated pliable, porous, biodegradable scaffolds with poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) blends using a solvent-casting and particulate-leaching technique. Our study investigated the effects of four different processing parameters on pliability and pore morphology of the biodegradable scaffolds. The parameters investigated were the PLGA copolymer ratio, the PLGA/PEG blend ratio, the initial salt weight fraction, and the salt particle size. A wide range of shear moduli (0.59 to 9.55 MPa), porosities (0.798 to 0.942), and median pore diameters (71 to 154 microns) was able to be achieved by varying the combination of these parameters. Our study indicates that initial salt weight fraction and PLGA/PEG blend ratio have the most significant effects on the physico-mechanical properties of the scaffolds. Enhanced pliability of the three dimensional foams made with blends of PLGA and PEG is evidenced by the ability to roll them into a tube without macroscopic damage to the scaffold. Pliable polymer substrates hold great promise for regeneration of soft tissues such as skin, or those requiring a tubular conformation such as intestine or vascular grafts.
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Zaman SS, Seykora JT, Hodinka RL, Gupta PK, Pietra GG. Cytologic manifestations of respiratory syncytial virus pneumonia in bronchoalveolar lavage fluid: a case report. Acta Cytol 1996; 40:546-51. [PMID: 8669193 DOI: 10.1159/000333913] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Respiratory syncytial virus (RSV) pneumonia in immunocompromised patients, especially bone marrow transplant recipients, is associated with high mortality. Early diagnosis in these cases is important because antiviral therapy with ribavirin is effective in reducing mortality. CASE A 45-year-old male with multiple myeloma who underwent autologous peripheral stem cell transplantation subsequently developed bilateral pulmonary infiltrates. A bronchoalveolar lavage specimen demonstrated the cytologic changes associated with RSV pneumonia. Infection with RSV was confirmed by indirect immunofluorescence, enzyme immunoassay and, later, on histology and electron microscopy at autopsy. CONCLUSION Recognition of the cytologic changes associated with RSV pneumonia in immunodeficient patients can be life saving since this would initiate confirmatory immunologic studies and therapy.
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Look RM, Lim SW, Waxman AD, Gupta PK, Fuerst MM, Kusuanco DA, Lawrence GN, Giles FJ. Technetium-99m sestamibi scanning in multiple myeloma stem cell transplantation. Leuk Lymphoma 1996; 20:453-6. [PMID: 8833402 DOI: 10.3109/10428199609052428] [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: 02/02/2023]
Abstract
We report the use of technetium-99m sestamibi (MIBI) in a patient with multiple myeloma (MM) undergoing peripheral blood stem cell (PBSC) transplantation. MIBI is a radionuclide agent that is preferentially taken up by malignant tumors. Plain radiographs in a MM patient, taken prior to PBSC transplantation, showed a large right humeral lytic lesion that correlated with increased uptake of MIBI at the same location. MIBI uptake, demonstrating active MM bone disease, was also evident in areas which were normal on plain radiographs. Three months after PBSC transplant, the lytic lesion had healed by plain radiographs and repeat MIBI scan showed no uptake. MIBI scanning results have a positive correlation with plain radiographs, and more importantly, demonstrate active MM bone disease not yet detectable by plain radiographs. If MIBI proves more sensitive in the detection of MM bone disease than plain radiographs or bone scanning with traditional isotopes, it will have a significant role in the detection of early disease and in monitoring disease progression during and after therapy.
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Gupta PK, Mital BK, Garg SK. Characterization of Lactobacillus acidophilus strains for use as dietary adjunct. Int J Food Microbiol 1996; 29:105-9. [PMID: 8722191 DOI: 10.1016/0168-1605(95)00014-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Seven Lactobacillus acidophilus strains were studied for their morphology, biochemical properties, growth behaviour, bile tolerance, cholesterol uptake and survival at low pH. The strains significantly differed in their biochemical and beneficial traits. The strains which exhibited cholesterol uptake and ability to grow in the presence of 0.3% bile salt also utilized mannitol.
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295
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Look RM, Koh HA, Hamburg SI, Lim SW, Waxman AD, Jochelson MS, Gupta PK, Fuerst MM, Kusuanco DA, Lawrence GN, Giles FJ. Technetium-99m Sestamibi Scanning Reflects Marrow Activity in a β-Thalassemia Patient Treated with an Allogeneic Bone Marrow Transplant. Hematology 1996; 1:173-6. [PMID: 27406433 DOI: 10.1080/10245332.1996.11746302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
β-thalassemia major is a disorder of globin synthesis, resulting in anemia and compensatory bone marrow hyperproliferation. Conventional imaging studies do not measure bone marrow activity reliably. We report on the use of technetium-99m sestamibi (MIBI) in a β-thalassemia major patient treated with an allogeneic bone marrow transplant. Pre-transplant and early post-transplant MIBI scannings demonstrated generalized marrow uptake, reflecting marrow hyperproliferation. After full engraftment, post-transplant MIBI showed disappearance of abnormal uptake in the skeleton, indicating normalization of the marrow activity. MIBI scan may be used as a noninvasive measure of bone marrow proliferation that may guide hypertransfusion therapy in thalassemia patients.
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Wied GL, Bartels PH, Bibbo M, Gupta PK, Gurley AM, Hilgarth M, Jiménez-Ayala M, Kato H, Knight BK, McGoogan E, Medley G, Meisels A, Nishiya I, Nozawa S, Ramzy I, Reith A, Rilke F, Rivera-Pomar JM, Rosenthal DL, Schenck U, Verhest AP, Vooijs GP. Computer-assisted quality assurance. Acta Cytol 1996; 40:1-3. [PMID: 8604561 DOI: 10.1159/000333452] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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297
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Gupta PK, Singh AK, Naik RT, Borgohain R, Dinakar I. Evolution of a tubercular abscess on prolonged antitubercular treatment. THE JOURNAL OF THE ASSOCIATION OF PHYSICIANS OF INDIA 1996; 44:67-8. [PMID: 8773103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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298
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Shao C, Gupta PK, Sun Y, Sahota A, Tischfield JA. Complex chromosomal mechanisms lead to APRT loss of heterozygosity in heteroploid cells. CYTOGENETICS AND CELL GENETICS 1996; 75:216-21. [PMID: 9067427 DOI: 10.1159/000134486] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Loss of the wild-type allele of a tumor suppressor gene, or loss of heterozygosity (LOH), is one of the most important mechanisms of carcinogenesis. Adenine phosphoribosyltransferase (APRT) has been used as a surrogate marker for tumor suppressor genes. We have previously shown that APRT deficiency in an APRT heterozygous human cell line, MR12-1, was predominantly caused by the loss of the remaining wild-type allele. Here we report the characterization of the chromosomal pathways leading to LOH in four clones derived from this heteroploid cell line. We performed karyotype analysis, chromosome 16-specific painting, and fluorescence in situ hybridization with an APRT-containing cosmid on these clones and their heteroploid parental cells. Our findings suggest that LOH occurs in tetraploid as well as diploid cells, and that diploid cells with LOH may undergo endoreduplication to attain tetraploidy. Our results also suggest that, in addition to LOH being caused by a single event (such as mitotic recombination or deletion), LOH may be caused by a combination of sequential events, such as mitotic recombination or translocation followed by chromosome loss. The instability of the genomes of the parental cells may have provided a greater diversity of options for genetic evolution. Similar karyotypic evolution may occur at late stages of carcinogenesis in vivo.
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Dinakar I, Gupta PK, Ratnakar KS. Diagnostic dilemma of an intramedullary vascular malformation. A case report. Angiology 1995; 46:1063-8. [PMID: 7486231 DOI: 10.1177/000331979504601115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A young man was seen at a neurologic center for a slowly progressive myelopathy involving the lower limbs in 1983. After examination and investigations, a diagnosis of chronic tuberculous spinal arachnoiditis was made and the patient was administered antituberculous treatment. However, his condition continued to deteriorate. He was reviewed at another center in 1985, where a diagnosis of demyelinating disorder was made, for which he was treated. However, this also did not help, and he was diagnosed as having a nonspecific spinal arachnoiditis at yet another center in 1988. His condition continued to worsen, and after ten years of symptoms, when magnetic resonance imaging (MRI) was done, an intramedullary cystic lesion opposite D-12 vertebrae was seen, which on histopathology was proved to be a vascular malformation. After excision of the lesion his neurologic status has been slowly improving. The conditions that a malformation could mimic, misleading a clinician, and the role of MRI in clinching the diagnosis are highlighted.
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Logan LS, Gupta PK. Modified staining technique for the on-site evaluation of fine-needle aspiration specimens from fatty tissues. Diagn Cytopathol 1995; 13:345-6. [PMID: 8599923 DOI: 10.1002/dc.2840130416] [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: 01/31/2023]
Abstract
The adequacy of on-site evaluation of fine-needle aspiration from fatty tissues can be complicated by less than optimal adherence or fixation of the aspirated cells to the surface of the glass slide. This article describes a modified staining technique that optimizes the recovery of material in such circumstances.
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