201
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Salamah SD, Hossain MM, Ahmed T. Enquiry into the causes of misuse of antibiotics. Saudi Med J 2000; 21:986-7. [PMID: 11369973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023] Open
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202
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Salamat N, Saleem M, Ahmed T. Lupus coagulant and anticardiolipin antibodies in patients with recurrent fetal loss: a case control study. Ann Saudi Med 2000; 20:450-3. [PMID: 17264648 DOI: 10.5144/0256-4947.2000.450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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203
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Ahmed T, Iskandrani A, Uddin MN. Sodium bicarbonate solution nebulization in the treatment of acute severe asthma. Am J Ther 2000; 7:325-7. [PMID: 11317181 DOI: 10.1097/00045391-200007050-00012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This is a case report of a 15-year-old asthmatic girl who was admitted with a severe acute attack of bronchial asthma who eventually recovered, possibly with the help of sodium bicarbonate solution nebulization.
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204
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Sabaawy HE, Farley T, Ahmed T, Feldman E, Abraham NG. Synergetic effects of retrovirus IFN-alpha gene transfer and 5-FU on apoptosis of colon cancer cells. Acta Haematol 2000; 101:82-8. [PMID: 10202238 DOI: 10.1159/000040929] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Gene transfer has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells including the most primitive stem cells and cancer cells. Several investigators have reported on the clinical effects of interferon-alpha (IFN-alpha) or the combination of 5-FU plus IFN-alpha on patients with advanced colorectal carcinoma. Therefore, we examined the ability of a retrovirus-mediated IFN-alpha gene transfer to infect colon cancer cells COLO 201 and the effect of IFN-alpha gene expression alone or in combination with other chemotherapeutic drugs as 5-FU. IFN-alpha showed positive antitumor activity against COLO 201 cells, whereas 5-FU showed time- and concentration-dependent antitumor activity against COLO 201 cells. Furthermore, we demonstrated that combination therapy of IFN-alpha gene transfer and 5-FU resulted in enhancement of cancer cell lethality. The potentiation increased with higher concentrations of 5-FU by 1.5- to 2.1-fold. Our results suggest that retrovirus-mediated IFN-alpha gene transfer in COLO 201 cells resulted in functional gene expression as assessed by the levels of IFN-alpha mRNA and protein; furthermore, the combination of IFN-alpha gene transfer and 5-FU have additional effects on the induction of apoptosis. This finding provides an experimental basis for possible clinical therapy using retrovirus-mediated IFN-alpha gene transfer alone or in combination with other chemotherapeutic drugs for treatment of colorectal cancer.
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Chiao JW, Moonga BS, Yang YM, Kancherla R, Mittelman A, Wu-Wong JR, Ahmed T. Endothelin-1 from prostate cancer cells is enhanced by bone contact which blocks osteoclastic bone resorption. Br J Cancer 2000; 83:360-5. [PMID: 10917552 PMCID: PMC2374574 DOI: 10.1054/bjoc.2000.1261] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The causes for the propensity of metastasized prostate cancer cells to grow in bone and to induce osteoblastic lesions remain unresolved. Co-culture of human prostate cancer cell lines with bone slices was determined to increase the level of endothelin-1 (ET-1) mRNA and its production. ET-1 is an ejaculate protein that also stimulates osteoblasts. Osteoclastic bone resorption was significantly blocked by the presence of androgen-independent prostate cancer cells in a dose-dependent manner as that of synthetic ET-1. The inhibition could be neutralized by specific ET-1 antibody, indicating the association of prostate cancer-derived ET-1 with inhibition of bone resorption. The combined ET-1 activity on osteoclasts and osteoblasts disrupts bone remodelling. ET-1 production is also elevated in the presence of prostate-specific antigen (PSA). ET-1 in turn enhances DNA synthesis of prostate cancer cells. Interactions among cancer cells, bone, ET-1 and PSA may be critical in cancer growth and lesions in bone.
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206
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Feldman EJ, Seiter K, Traganos F, Darzynkiewicz Z, Goff H, Pozzuoli M, Baskind P, Santos S, Ahmed T. Phase II evaluation of a high-dose mitoxantrone based induction regimen in untreated adults with acute myeloid leukemia. Leuk Lymphoma 2000; 38:309-15. [PMID: 10830737 DOI: 10.3109/10428190009087021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To evaluate a regimen including high-dose mitoxantrone in previously untreated adults with AML, 45 patients aged 21-59 (median 41) were given cytarabine, 3 g/m2 days 1-5, mitoxantrone, 80 mg/m2 day 2 and etoposide, 150 mg/m2 days 1,3,5. Post-remission therapy consisted of 5 cycles combining the same agents at reduced doses. Complete remission was seen in 36 patients. The observed 3-year survival is 28%. Cytogenetic pattern and CD34 expression correlated with response and survival. Significant toxicity included myelosuppression, mucositis, diarrhea and hyperbilirubinemia. Ventricular ejection fraction was generally reduced, with clinical cardiac dysfunction in only 2 patients. This high-dose mitoxantrone combination can be administered to young adults with AML with tolerable toxicity and results comparable to those of other dose-intensive regimens.
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207
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Chiao JW, Chung F, Krzeminski J, Amin S, Arshad R, Ahmed T, Conaway CC. Modulation of growth of human prostate cancer cells by the N-acetylcysteine conjugate of phenethyl isothiocyanate. Int J Oncol 2000; 16:1215-9. [PMID: 10811998 DOI: 10.3892/ijo.16.6.1215] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
There is growing evidence that thiol conjugates of isothiocyanates present in cruciferous vegetables are effective cancer chemopreventive and potentially active therapeutic agents. The effects of the N-acetylcysteine conjugate of phenethyl isothiocyanate (PEITC-NAC) on tumor cell growth were analyzed in human prostate cancer cell lines LNCaP, androgen-dependent, and DU-145, androgen-independent. Exposure of the cells to PEITC-NAC at high concentrations caused cytolysis, while at lower concentrations PEITC-NAC mediated a dose-dependent growth modulation, with reduction of DNA synthesis and growth rate, inhibition of clonogenicity and induction of apoptosis in both types of prostate cancer cells. PEITC-NAC decreased cells in S and G2M phases of cell cycle, blocking cells entering replicating phases. In parallel, a significant enhancement of cells expressing the cell cycle regulator p21 as well as its intensity was determined using a fluorescent antibody technique. The action of PEITC-NAC was time-dependent, with the magnitude of inhibition increasing to 50-65% after PEITC-NAC exposure for several days. Interaction of tumor cells with dissociation products of PEITC-NAC, PEITC and NAC, are proposed as the mechanism of growth regulation.
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208
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Ahmed T, Semmens MJ, Voss MA. Energy loss characteristics of parallel flow bubbleless hollow fiber membrane aerators. J Memb Sci 2000. [DOI: 10.1016/s0376-7388(00)00300-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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209
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Wrigley JD, Ahmed T, Nevett CL, Findlay JB. Peripherin/rds influences membrane vesicle morphology. Implications for retinopathies. J Biol Chem 2000; 275:13191-4. [PMID: 10747861 DOI: 10.1074/jbc.c900853199] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peripherin/rds is an integral membrane glycoprotein found in the rim regions of vertebrate photoreceptor cell discs. Natural mutations of the encoding gene result in degenerative retinal disorders, such as retinitis pigmentosa. The retinal degeneration slow (rds) phenotype, observed in mice, is considered to be an appropriate model for peripherin/rds-mediated retinitis pigmentosa. Associated abnormalities in the outer segment of photoreceptor cells have implicated peripherin/rds in some aspect of disc morphology, yet it remains unclear whether such morphological effects are the cause or the result of this condition. Here we present the first direct evidence to support a role for peripherin/rds in maintaining the flattened vesicle morphology characteristic of photoreceptor outer segments. In vitro expression yields a 36-kDa immunoreactive species, which is inserted into membranes and undergoes N-glycosylation, inter- and intramolecular disulfide bonding, and dimerization. Electron microscopy reveals that peripherin/rds flattens microsomal vesicles. This effect appears to be dependent on disulfide bond formation but not N-glycosylation. The inability of two pathogenic peripherin/rds mutants (P216L and C165Y) to flatten membrane vesicles implicates such mutations as the primary cause of the retinal degeneration observed in retinitis pigmentosa.
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Ahmed T, Kancherla R, Qureshi Z, Mittelman A, Seiter K, Mannancheril A, Puccio C, Chun HG, Bar M, Lipshutz M, Ali MF, Goldberg R, Preti R, Lake D, Durrani H, Farley T. High-dose chemotherapy and stem cell transplantation for patients with stage IV breast cancer without clinically evident disease: correlation of CD34+ selection to clinical outcome. Bone Marrow Transplant 2000; 25:1041-5. [PMID: 10828863 DOI: 10.1038/sj.bmt.1702374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Forty-five patients with metastatic breast cancer without clinically evident disease were treated with thiotepa 750 mg/m2, mitoxantrone 40 mg/m2 and carboplatin 1000 mg/m2 followed by stem cell transplantation to determine the safety and efficacy of CD34+ selection of peripheral blood stem cells. Of these, 15 patients' (group I) stem cells were processed through Baxter Isolex 300 device for CD34+ selection, whereas 30 patients (group II) received unmanipulated stem cells. Toxicity, progression-free survival and survival were compared between these two groups. There was no difference in transfusion requirements, white cell count and platelet recovery and non-hematologic toxicity between the two groups. The survival of patients in group I was 27 months compared to 38 months in group II (P = 0.8). The progression-free survival was 12 months and 13.5 months for group I and group II patients, respectively (P = 0.6). Our results indicate that while there is no adverse effect, there is also no significant advantage of CD34+ selection in terms of progression-free survival and survival in patients with metastatic breast cancer without clinically evident disease. Bone Marrow Transplantation (2000).
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211
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Ahmed T, Ungo J, Zhou M, Campo C. Inhibition of allergic late airway responses by inhaled heparin-derived oligosaccharides. J Appl Physiol (1985) 2000; 88:1721-9. [PMID: 10797135 DOI: 10.1152/jappl.2000.88.5.1721] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Inhaled heparin has been shown to inhibit allergic bronchoconstriction in sheep that develop only acute responses to antigen (acute responders) but was ineffective in sheep that develop both acute and late airway responses (LAR) (dual responders). Because the antiallergic activity of heparin is molecular-weight dependent, we hypothesized that heparin-derived oligosaccharides (<2, 500) with potential anti-inflammatory activity may attenuate the LAR in the dual-responder sheep. Specific lung resistance was measured in 24 dual-responder sheep before and serially for 8 h after challenge with Ascaris suum antigen for demonstration of early airway response (EAR) and LAR, without and after treatment with inhaled medium-, low-, and ultralow-molecular-weight (ULMW) heparins and "non-anticoagulant" fractions (NAF) of heparin. Airway responsiveness was estimated before and 24 h postantigen as the cumulative provocating dose of carbachol that increased specific lung resistance by 400%. Only ULMW heparins caused a dose-dependent inhibition of antigen-induced EAR and LAR and postantigen airway hyperresponsiveness (AHR), whereas low- and medium-molecular-weight heparins were ineffective. The effects of ULMW heparin and ULMW NAF-heparin were comparable and inhibited the LAR and AHR even when administered "after" the antigen challenge. The ULMW NAF-heparin failed to inhibit the bronchoconstrictor response to histamine, carbachol, and leukotriene D(4), excluding a direct effect on airway smooth muscle. In six sheep, segmental antigen challenge caused a marked increase in bronchoalveolar lavage histamine, which was not prevented by inhaled ULMW NAF-heparin. The results of this study in the dual-responder sheep demonstrate that 1) the antiallergic activity of inhaled "fractionated" heparins is molecular-weight dependent, 2) only ULMW heparins inhibit the antigen-induced EAR and LAR and postantigen AHR, and 3) the antiallergic activity is mediated by nonanticoagulant fractions and resides in the ULMW chains of <2,500.
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212
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Ahmed T, Kelly SM, Price NC, Lawrence AJ. Activation of phospholipase A(2) by long chain fatty acyl groups involves a novel unstable linkage. J Biochem 2000; 127:871-5. [PMID: 10788797 DOI: 10.1093/oxfordjournals.jbchem.a022681] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The acidic isoform of phospholipase A(2) from Naja mossambica mossambica was activated by treatment with a molar equivalent of oleoyl imidazolide. Modification of the protein was accompanied by 50% quenching of tryptophan fluorescence and a significant red shift. The (3)H(9,10) labeled oleoyl residue was co-eluted with the enzyme during gel filtration in the presence of 20% 1-propanol or excess albumin, both of which remove free oleic acid from the enzyme. In contrast, the adduct was labile as to electrophoresis on SDS-PAGE and acid or alkali urea PAGE. The formation of a covalently linked adduct was demonstrated by electrospray mass spectrometry in the presence of 2% formic acid. No such adduct was formed by the phospholipase A(2) isoform from Naja naja atra, which differs in sequence from the N. mossambica mossambica isoform by seven residues including 2 histidine residues and 1 lysine residue. We conclude that oleoyl imidazolide activates the N. mossambica mossambica enzyme by forming an acyl adduct which is unstable as to protein denaturation. The magnitude of tryptophan fluorescence quenching indicates that the site of acylation lies in the sequence WWHF.
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213
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Mittelman A, Chun HG, Puccio C, Coombe N, Lansen T, Ahmed T. Phase II clinical trial of didemnin B in patients with recurrent or refractory anaplastic astrocytoma or glioblastoma multiforme (NSC 325319). Invest New Drugs 2000; 17:179-82. [PMID: 10638489 DOI: 10.1023/a:1006379402114] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The activity of didemnin B, a natural product derived from the Caribbean Tunic was assessed in 16 patients with Glioblastoma multiforme. Didemnin B was administered intravenously by a short infusion at a dose of 4.3 mg/m2 and subsequently escalated to 6.3 mg/m2. No anti-tumor activity was observed. Toxicity consisted of fatigue, weakness, stomatitis, mild blood count changes, nausea and vomiting and occasional fever. Based on these results further studies with didemnin B in patients with Glioblastoma multiforme are not recommended.
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214
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Seiter K, Feldman EJ, Dorota Halicka H, Deptala A, Traganos F, Burke HB, Hoang A, Goff H, Pozzuoli M, Kancherla R, Darzynkiewicz Z, Ahmed T. Clinical and laboratory evaluation of all-trans retinoic acid modulation of chemotherapy in patients with acute myelogenous leukaemia. Br J Haematol 2000; 108:40-7. [PMID: 10651722 DOI: 10.1046/j.1365-2141.2000.01804.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
All-trans retinoic acid (ATRA) is synergistic with chemotherapy in leukaemia cell lines. We treated 53 patients with newly diagnosed acute myelogenous leukaemia (AML) with high-dose cytarabine-based chemotherapy followed by ATRA. Peripheral blood and bone marrow samples were obtained to study the effect of in vitro exposure to ATRA and to measure apoptosis and bcl-2. The response rate was 72% for patients under age 60 years and 46% for patients aged 60 years or above. There was no difference in the percentage of responding patients, time to recurrence or overall survival for patients receiving chemotherapy with ATRA vs. historical controls receiving chemotherapy without ATRA. After in vitro exposure of day 3 bone marrow samples to ATRA, there was an increase in apoptotic cells in 25% of patient samples compared with samples not exposed to ATRA. Later date of peak apoptosis in peripheral blood and higher percentage of apoptotic cells in bone marrow on day 3 of treatment were associated with lack of clinical response to treatment. Increased bcl-2 in patient samples was associated with shorter time to recurrence and poor cytogenetic risk. The addition of ATRA to chemotherapy did not improve patient outcome. However, evidence of in vitro response to ATRA in 25% of patients suggests that retinoid pathways should be studied further in patients with AML.
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215
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Stein M, Feldman E, Seiter K, Chiao JW, Goff H, Baskind P, Beer M, Ahmed T. Cyclosporine-induced autologous graft-versus-host disease in patients with acute myeloid leukemia undergoing non-myeloablative chemotherapy without progenitor cell reinfusion. Bone Marrow Transplant 1999; 24:1073-7. [PMID: 10578157 DOI: 10.1038/sj.bmt.1702034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
To determine the incidence and severity of cyclosporine-induced graft-versus-host disease following non-myeloablative chemotherapy without progenitor cell reinfusion in patients with acute leukemia, 17 adults with refractory acute myeloid leukemia (14) or blastic phase of chronic myeloid leukemia (3) were treated with etoposide 2400 mg/m2 and cyclophosphamide 120 mg/kg followed by cyclosporine (CsA) 2.5 mg/kg i.v. daily and interferon gamma 0.025 mg/m2 subcutaneously every other day until day 28. Skin biopsies were obtained on days 14 and 28, or on the appearance of a skin rash, and graded for GVHD. Blood samples were examined at baseline and weekly starting on day 14 for natural killer (NK) cell and T cell lymphocytic changes. Post-treatment lymphocytes from select patients were assessed for allogeneic NK cell and autologous leukemic cell cytolytic activity. Four patients developed pathologic grade 2 cutaneous acute GVHD. Of the three patients who achieved a complete remission, two had evidence of GVHD. Post-treatment, three patients (two with GVHD) in whom adequate numbers of lymphocytes could be obtained showed NK cell cytolytic activity against allogeneic tumor cells (K562), but none had cytolytic activity against their own cryopreserved leukemic cells. These data suggest that in patients with AML treated with subablative doses of chemotherapy without autotransplant, autologous GVHD can be induced, although at an incidence lower than that reported for CsA-induced GVHD following marrow transplantation. An enhancement of T cell and NK cell activity levels similar to experiences in syngeneic models of autologous GVHD was seen, but no direct autologous leukemic cell cytotoxicity could be demonstrated.
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Ahmed T. International Society on Thrombosis and Hemostasis--17th congress. 14-21 August 1999, Washington, DC, USA. IDRUGS : THE INVESTIGATIONAL DRUGS JOURNAL 1999; 2:1139-42. [PMID: 16113985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
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217
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Quan S, Feldman E, Yang L, Wagener FA, Farley TJ, Abraham NG, Ahmed T. Distinct effect of retroviral-mediated IFN-alpha gene transfer on human erythroleukemic and CD34+ cell growth and differentiation. JOURNAL OF HEMATOTHERAPY & STEM CELL RESEARCH 1999; 8:491-502. [PMID: 10791900 DOI: 10.1089/152581699319948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Human interferon-alpha (IFN-alpha) has been used in the management of leukemia, but its diverse adverse effects may influence the ability of IFN-alpha to treat this disease. We constructed two retroviral vectors, LSN-IFN-alpha and LNC-IFN-alpha, in which IFN-alpha cDNA was driven by viral LTR and CMV promoters, respectively. After transduction into the PA317 and PG13 retroviral packaging cells, high titers of retrovirus were produced and were used to infect K562 and human BM CD34+ hematopoietic cells. The IFN-alpha gene expression in transduced K562 cells was confirmed by Northern blot, RT-PCR, RIA, and biologic assay. Cell proliferation and cell viability in IFN-alpha-transduced K562 cells were significantly suppressed as compared with control K562 cells. Although the IFN-alpha expression in K562 cells did not affect BCR/ABL expression, it apparently upregulated the production of adhesion molecules (VLA-4 and Mac-1). We evaluated the effect of IFN-alpha gene transfer on human CD34+ cells infected with LSN-IFN-alpha retrovirus with the aid of fibronectin (FN) fragment CH-296 and growth factors. RIA showed that IFN-alpha-transduced CD34+ cells produced 72.2+/-15 U/ml of IFN-alpha compared with 4.3+/-1.2 U/ml in control CD34+ cells. Methylcellulose clonogenic assay indicated that IFN-alpha-transduced CD34+ cells produced similar numbers of burst-forming units-erythrocytes (BFU-E)/colony-forming units-GM (CFU-GM) colonies as compared with control CD34+ cells. Selected colonies expressed IFN-alpha and neo(r) mRNA, as measured by RT-PCR. These studies indicate that retrovirus-mediated IFN-alpha gene transfer may provide a useful tool for studying the effect of IFN-alpha gene transfer on leukemic cells and long-lived CD34+ cells.
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Chiao JW, Xu W, Yang YM, Kancherla R, Seiter K, Ahmed T, Mittelman A. Regulation of growth and apoptosis of breast cancer cells by a 54 kDa lymphokine. Int J Oncol 1999; 15:835-8. [PMID: 10493970 DOI: 10.3892/ijo.15.4.835] [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: 11/06/2022] Open
Abstract
A normal human lymphocyte-derived 54 kDa polypeptide, capable of regulating cell growth has been identified as an isoform variant (abbreviated as NP54) of protein neuroleukin-phosphoglucose isomerase (PGI). Since distinct PGI variants undetectable in normal tissues had been identified in breast cancer tissues, the effect of NP54 on the growth of human breast cancer cells SK-Br-3 in cultures was analyzed. Exposure to NP54 caused a dose-dependent growth modulation. Approximately 40% reduction of cell density was detected at 40 pM of NP54, along with a blocking of G1 cells entering into S phase. The growth modulation was correlated with a significantly reduced expression of epidermal growth factor receptor (EGF-R) gene transcript, supporting the interpretation that the level of EGF-R expression and cell growth are related mechanisms. NP54 treatment also significantly increased cells with apoptotic morphological feature and fragmented DNA. Incubation with a monoclonal anti-NP54 antibody negated NP54 activity, confirming a regulatory activity in cell growth and apoptosis.
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Quan S, Seiter K, Feldman E, Yang L, Argani I, Farley TJ, Abraham NG, Ahmed T. Human CD34+ hematopoietic cells transduced by retrovirus-mediated interferon alpha gene maintains regeneration capacity and engraftment in NOD/SCID mice. Exp Hematol 1999; 27:1511-8. [PMID: 10517492 DOI: 10.1016/s0301-472x(99)00095-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To achieve long-term expression of human interferon alpha-5 (IFNalpha) gene in the bone marrow (BM) hematopoietic microenvironment, replication-deficient retroviral vector LSN-IFNalpha was used to deliver the IFNalpha gene into human BM CD34+ cells. After fibronectin-facilitated transduction, a fraction of CD34+ cells was plated in methylcellulose medium with or without G418 to assess transduction efficiency and the effect of IFNalpha gene transfer on colony formation. Colony-forming assay in the presence of G418 (400 microg/mL) revealed that 41% CFU-GM colonies are G418 resistant after infection with LSN-IFNalpha retrovirus. There was no significant difference in CFU-GM/BFU-E colony formation among IFNalpha gene-transduced CD34+ cells, control vector (LXSN) transduced-CD34+ cells and nontransduced CD34+ cells. Another portion of CD34+ cells was grown in liquid medium to measure IFNalpha production. RIA revealed that IFNalpha gene-transduced CD34+ cells produced 72.2 +/- 15.4 U/mL (10(6) cells/24 hours) of IFNalpha compared with 8.3 +/- 2.1 U/mL and 4.3 +/- 1.2 U/mL in LXSN-transduced or nontransduced CD34+ cells, respectively. The remaining portion of transduced CD34+ cells was transplanted into immunodeficient (NOD/SCID) mice to allow analysis of long-term expression of IFNalpha. Transplantation of 1x10(6) CD34+ cells into sublethally irradiated NOD/SCID mice showed that IFNalpha and neo(r) mRNA were detectable in engrafted mouse BM cells for up to 6 months. We conclude that continual local expression of IFNalpha in transduced CD34+ cells does not impair either CD34+ cell growth and differentiation or engraftment and long-term survival in NOD/SCID mice.
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Seiter K, Kancherla R, Yang L, Quan S, Farley TJ, Abraham NG, Ahmed T. Adenovirus and retrovirus mediated interferon alpha gene transfer into CD34+ cells maintains regeneration capacity and enhances adhesion molecules in K562 cells. J Investig Med 1999; 47:414-24. [PMID: 10510594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND Systemic administration of interferon-alpha (IFN-alpha) results in cytogenetic remissions and enhanced survival in a significant percentage of patients with chronic mylogenous leukemia (CML) and lymphoma. However, this treatment is associated with deleterious toxic effects. Gene transfer of the IFN-alpha gene into hematopoietic progenitors represents a novel strategy to deliver high concentrations of IFN-alpha to a local area. METHODS We compared the effect of the transfer of the IFN-alpha gene on the cell growth and differentiation of several CD34+ cells in culture and in a NOD/SCID animal model, using adenovirus and retrovirus constructs. RESULTS Transient local expression of the IFN-alpha gene using an adenovirus vector was associated with normal proliferation of CD34+ progenitors as measured by a colony forming unit of granulocyte-macrophage (CFU-GM) growth. Flow cytometric determination revealed that there was no significant difference in viability of these cells for 24-hour transduction periods. Reverse transcriptase/polymerase chain reaction (RT-PCR) analysis of RNA from CD34+ harvested CFU-GM progenitors demonstrated expression of IFN-alpha mRNA; radioimmunoassay (RIA) revealed that transduced cells secreted substantial levels of IFN-alpha protein. Furthermore, we constructed a retroviral vector in which IFN-alpha cDNA was driven by a viral LTR promoter to evaluate the effect of permanent IFN-alpha gene expression on cell growth. Retroviral packaging cells PA317 with high titers of retrovirus were produced and used to infect CD34+ and K562 cells. RIA showed that IFN-alpha-transduced CD34+ cells (with the aid of fibronectin fragment CH-296) produced approximately 400 units of IFN-alpha protein compared to CD34+ cells, or cells transduced with empty vector. IFN-alpha transduced CD34+ generated similar numbers of CFU-GM colonies as compared to control CD34+ cells. Engraftment of CD34+ cells transduced with IFN-alpha gene in NOD/SCID mice was successful for the first 30 days. Additionally, we studied the effect of local IFN-alpha expression on the cellular adhesion molecules, VLA-4, Mac-1, ICAM-1, and L-selectin in K562 cells, and human umbilical endothelial vein cells. K562 cells transduced with the IFN-alpha gene expressed a significantly elevated level of VLA-4, Mac-1, and ICAM-1. CONCLUSIONS We conclude that expression of the IFN-alpha gene using retrovirus vectors results in an adequate localized expression of IFN-alpha mRNA and protein.
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Ahmed T, Kelly SM, Price NC, Lawrence AJ. Activation of the acidic isoform of phospholipase A2 from Naja mossambica mossambica venom by oleoyl imidazolide requires the cooperative action of two ionizing groups. IUBMB Life 1999; 48:287-91. [PMID: 10690640 DOI: 10.1080/713803513] [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: 10/23/2022]
Abstract
The acidic phospholipase A2 isoform from the spitting cobra Naja mossambica mossambica is activated irreversibly by treatment with a molar equivalent of oleoyl imidazolide. The kinetics of the chemical modification of the enzyme can also be monitored by measuring the large reduction of tryptophan fluorescence, which is accompanied by a distinct red shift. The addition of a single molar equivalent of oleic acid to the enzyme produces an instantaneous reduction in fluorescence but with a barely detectable red shift, confirming that the response to oleoyl imidazolide results from covalent modification of the protein rather than hydrolysis of the reagent. The pH dependence of both activation and fluorescence reduction by oleoyl imidazolide has an optimum rate near pH 8.0. We propose that long-chain fatty acids and long-chain acyl imidazolides bind at a single activation site and that the reaction of the imidazolides involves two protein residues, one of which is a nonessential histidine residue and the other a primary amino group.
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Ahmed T, Gonzalez BJ, Danta I. Prevention of exercise-induced bronchoconstriction by inhaled low-molecular-weight heparin. Am J Respir Crit Care Med 1999; 160:576-81. [PMID: 10430731 DOI: 10.1164/ajrccm.160.2.9812076] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Because many biological actions of heparin including the antiallergic activity are molecular weight dependent, we hypothesized that low-molecular-weight heparin (LMWH) may have greater potency in attenuating exercise-induced bronchoconstriction (EIB). Therefore, in the present investigation we studied the effects of inhaled LMWH, enoxaparin, and unfractionated heparin on EIB in subjects with asthma. Thirteen asthmatic subjects performed a standardized exercise challenge on a treadmill to document the presence of EIB. The workload was increased until 85% of predicted maximal heart rate was achieved, and the exercise was sustained at that workload for 10 min. EIB was assessed by measuring FEV(1) before and immediately after the exercise. On five different experiment days the subjects were pretreated with 4 ml of aerosolized heparin (80,000 units = 7.5 mg/kg), placebo, or 3 different doses of enoxaparin (0.5 mg/kg, 1 mg/kg, 2 mg/kg) in a double-blind, randomized, crossover design, and exercise challenge was performed 45 min later. Bronchial provocation with methacholine was also performed in five subjects on two additional days after pretreatment with either placebo or inhaled enoxaparin (2 mg/kg), and venous blood was obtained for analysis of plasma antifactor Xa. Postexercise, the maximal decreases in FEV(1) (mean +/- SE) were 30 +/- 4% and 29 +/- 5% on control and placebo days. The exercise-induced decreases in FEV(1) were inhibited by 31% with heparin (DeltaFEV(1) = 20 +/- 4%); and by 28%, 38%, and 48% by enoxaparin at doses of 0.5 mg/kg (DeltaFEV(1) = 21 +/- 5%), 1 mg/kg (DeltaFEV(1) = 18 +/- 5%), and 2 mg/kg (DeltaFEV(1) = 15 +/- 3%), respectively (p < 0.05). The inhibitory effect of 0.5 mg/kg dose of enoxaparin was comparable to heparin (7.5 mg/kg), whereas 2 mg/ kg dose of enoxaparin was the most potent. Inhaled enoxaparin failed to modify the bronchoconstrictor response to methacholine, and did not change the plasma antifactor Xa activity. These data demonstrate that inhaled enoxaparin prevents EIB in a dose-dependent manner; and its antiasthmatic activity is independent of its effect on plasma antifactor Xa activity.
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van Schaik P, Ahmed T, Suvakovic N, Hindmarsh JR. Effect of an educational multimedia prostate program on the International Prostate Symptom Score. Eur Urol 1999; 36:36-9. [PMID: 10364653 DOI: 10.1159/000019924] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To determine the effect of an interactive multimedia prostate education program (MMP) on self assessment of symptom scores due to benign prostatic hyperplasia (BPH). METHODS The interactive MMP was developed including a computer-administered version of the International Prostate Symptom Score (IPSS) questionnaire. Eighty-eight men referred to the Urology Out-patients with prostatic symptoms entered the study. They first completed the IPSS on paper and secondly used the MMP before completing the computer-administered IPSS. A final feedback questionnaire enquiring into their experience including previous exposure to computers, ease of use, and value of the program content was completed. RESULTS The use of the MMP resulted in a significant decrease in mean IPSS score from 16.6 to 13.9 (t = 7.456, d.f. = 87, p < 0.01), but no change in quality of life. Patients felt that their knowledge had increased (chi2(1) = 21.253, p < 0.01) and that they had completed the IPSS more accurately (chi2(1) = 10.227, p < 0.01) with the MMP IPSS module compared to the IPSS on paper. Previous use of patient education, patient characteristics and MMP use beyond the information required for the IPSS did not affect IPSS difference (IPSS before versus after MMP use). CONCLUSION The use of the MMP enhanced patients' knowledge of their condition and reduced patients' IPSS score. The results were independent of previous exposure to information, previous IPSS completion, computer use and age.
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Ahmed T, Ali M, Ullah MM, Choudhury IA, Haque ME, Salam MA, Rabbani GH, Suskind RM, Fuchs GJ. Mortality in severely malnourished children with diarrhoea and use of a standardised management protocol. Lancet 1999; 353:1919-22. [PMID: 10371570 DOI: 10.1016/s0140-6736(98)07499-6] [Citation(s) in RCA: 194] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Severely malnourished children have high mortality rates. Death commonly occurs during the first 48 h after hospital admission, and has been attributed to faulty case-management. We developed a standardised protocol for acute-phase treatment of children with severe malnutrition and diarrhoea, with the aim of reducing mortality. METHODS We compared severely malnourished children with diarrhoea aged 0-5 years managed by non-protocol conventional treatment, and those treated by our standardised protocol that included slow rehydration with an emphasis on oral rehydration. The standardised-protocol group included children admitted to the ICDDR,B Hospital, Dhaka between Jan 1, 1997, and June 30, 1997, while those admitted between Jan 1, 1996, and June 30, 1996, before the protocol was implemented, were the non-protocol group. FINDINGS Characteristics on admission of children on standardised protocol (n=334) and non-protocol children (n=293) were similar except that more children on standardised protocol had oedema, acidosis, and Vibrio cholerae isolated from stools. 199 (59.9%) of children on standardised protocol were successfully rehydrated with oral rehydration solution, compared with 85 (29%) in the non-protocol group (p<0.0001). Use of expensive antibiotics was less frequent in children on standardised protocol than in the other group (p<0.0001). Children on standardised protocol had fewer episodes of hypoglycaemia than non-protocol children (15 vs 30, p=0.005). 49 (17%) of children on non-protocol treatment died, compared with 30 (9%) children on standardised protocol (odds ratio for mortality, 0.49, 95% CI 0.3-0.8, p=0.003). INTERPRETATION Compared with non-protocol management, our standardised protocol resulted in fewer episodes of hypoglycaemia, less need for intravenous fluids, and a 47% reduction in mortality. This standardised protocol should be considered in all children with diarrhoea and severe malnutrition.
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Sabaawy HM, Ikehara S, Adachi Y, Quan S, Feldman E, Kancherla R, Abraham NG, Ahmed T. Enhancement of 5-fluorouracil cytotoxicity on human colon cancer cells by retrovirus-mediated interferon-alpha gene transfer. Int J Oncol 1999; 14:1143-51. [PMID: 10339671 DOI: 10.3892/ijo.14.6.1143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. Several reports documented the clinical effects of interferon-alpha (IFN-alpha) in management of patients with advanced colorectal carcinoma. We report for the first time, the successful transduction of human IFN-alpha gene into colon cancer cells, COLO 201 using a replication-defective retroviral vector. Retrovirus-containing supernatant from PA 317 packaging cells was used to infect colon cancer cells, COLO 201 and NIH 3T3 cells. Transient infection showed that cell proliferation and cell viability were significantly suppressed in colon cancer cells transduced with IFN-alpha gene. Moreover, IFN-alpha-transduced cells acquired less resistance to 5-FU induced apoptosis. These data demonstrate that IFN-alpha gene transfer may have a clinical application and can be combined with chemotherapy for treatment of advanced colorectal cancer.
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Ahmed T. Innovation in cardiovascular drugs: drug development portfolios. 3-4 March 1999, London, UK. IDRUGS : THE INVESTIGATIONAL DRUGS JOURNAL 1999; 2:400-2. [PMID: 16155839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This conference, organized by SMi, brought together representatives from some of the leading companies in cardiovascular (CV) drug development. The two-day meeting was chaired by Dr Ajay Kakkar (Thrombosis Research Institute, London, UK) and covered drug development portfolios, genetic approaches to therapy and innovative therapeutic strategies.
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Campo C, Molinari JF, Ungo J, Ahmed T. Molecular-weight-dependent effects of nonanticoagulant heparins on allergic airway responses. J Appl Physiol (1985) 1999; 86:549-57. [PMID: 9931190 DOI: 10.1152/jappl.1999.86.2.549] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have hypothesized that antiallergic activity of inhaled heparin is molecular weight dependent and mediated by "nonanticoagulant fractions" (NAF-heparin). Therefore, we studied comparative effects of high-, medium-, and ultralow-molecular-weight (HMW, MMW, and ULMW, respectively) NAF-heparins on acute bronchoconstrictor response (ABR) and airway hyperresponsiveness (AHR) in allergic sheep. Specific lung resistance was measured in 23 allergic sheep, before and immediately after challenge with Ascaris suum antigen, without and after pretreatment with inhaled NAF-heparins. Airway responsiveness was estimated before and 2 h postantigen as the cumulative provocating dose of carbachol in breath units, which increased specific lung resistance by 400%. NAF-heparins attenuated ABR and AHR in a molecular-weight-dependent fashion. HMW NAF-heparin (n = 8) was the least effective agent: it attenuated ABR [inhibitory dose causing 50% protection (ID50) = 4 mg/kg] but had no effect on AHR. MMW NAF-heparin (n = 8) showed intermediate efficacy (ABR ID50 = 0.8 mg/kg, AHR ID50 = 1.4 mg/kg), whereas ULMW NAF-heparin (n = 7) was the most effective agent (ABR ID50 = 0.4 mg/kg, AHR ID50 = 0.2 mg/kg). ULMW NAF-heparin was 3.5 times more potent in attenuating antigen-induced AHR when administered "after" antigen challenge and failed to inhibit the bronchoconstrictor response to carbachol and histamine. In 15 additional sheep, segmental antigen challenge caused a marked increase in histamine in bronchoalveolar lavage fluid that was not prevented by any of the inhaled NAF-heparins. These data indicate that antiallergic activity of inhaled heparin is independent of its anticoagulant action and resides in the <2,500 ULMW chains. The antiallergic activity of NAF-heparins is mediated by an unknown biological action and may have therapeutic potential.
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Mascie-Taylor CG, Alam M, Montanari RM, Karim R, Ahmed T, Karim E, Akhtar S. A study of the cost effectiveness of selective health interventions for the control of intestinal parasites in rural Bangladesh. J Parasitol 1999; 85:6-11. [PMID: 10207355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
The study examined the cost effectiveness of 4 different regimens in reducing the prevalence and intensity of infection of Ascaris lumbricoides, Trichuris trichiura, and hookworm over an 18-mo period in randomized community samples of children aged 2-8 yr living in rural Bangladesh. The household was the unit of randomization in each community. The 4 regimens were (1) only chemotherapy to all household members at the commencement of the study (i.e., at an interval of 18 mo), (2) same as group (1) and regular health education throughout the study period, (3) chemotherapy to all household members at the commencement of the study and subsequent chemotherapy to all children at intervals of 6 mo, and (4) same as group 3 with the addition of regular health education throughout the study period. Health education (through home and school visits and focus group discussions) was aimed at increasing awareness of worm transmission and the disabilities caused by intestinal helminths. Simple ways of improving personal hygiene and sanitation through hand washing, nail trimming, wearing of shoes, and use of a latrine and clean water supplies were encouraged. Because albendazole is a broad spectrum anthelmintic, the cost effectiveness of the 4 interventions were compared by the weighted percentage reduction in prevalence and the weighted percentage reduction in intensities of infection as measured by geometric mean egg loads of all 3 worms combined. The most cost-effective strategy was the single albendazole mass chemotherapy at an interval of 18 mo. The 2 regimens involving health education were the least cost effective.
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Mascie-Taylor CGN, Alam M, Montanari RM, Karim R, Ahmed T, Karim E, Akhtar S. A Study of the Cost Effectiveness of Selective Health Interventions for the Control of Intestinal Parasites in Rural Bangladesh. J Parasitol 1999. [DOI: 10.2307/3285691] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Chiao JW, Xu W, Seiter K, Feldman E, Ahmed T. Neuroleukin mediated differentiation induction of myelogenous leukemia cells. Leuk Res 1999; 23:13-8. [PMID: 9933130 DOI: 10.1016/s0145-2126(98)00129-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Leukemia cells enriched from peripheral blood of a patient with myelogenous leukemia were induced to differentiate with a purified T cell lymphokine neuroleukin. With sufficient neuroleukin concentrations, cells with macrophage-like morphology were identified among the developing adherent cells. After 2-5 days, approximately 38-50% of the suspension cells became macrophage-like and acquired CD21, alpha-naphthyl acetate reactivity and immune adherence capability. The amount of these nonproliferating cells increased along with cells containing fragmented DNA. Induction with insufficient neuroleukin quantity or with patient plasma alone developed few or no mature cells, indicating differentiation to mature cells is dose-dependent. The possibility of insufficient quantity of neuroleukin in regulation of patient plasma for differentiation was discussed.
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Feldman EJ, Seiter K, Chiao JW, Halicka HD, Traganos F, Fatora SR, McMichael J, Baskind P, Goff H, Beer M, Ahmed T, Darzynkiewicz Z. In vitro effects and clinical evaluation of a human chorionic gonadotrophin preparation in acute leukemia. Leukemia 1998; 12:1749-55. [PMID: 9823950 DOI: 10.1038/sj.leu.2401196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Commercial human chorionic gonadotrophin (HCG) preparations decrease the tumorigenicity of human tumors in immunodeficient mice and induce apoptotic cell death in animal tumor models. Preliminary studies in humans have demonstrated tumor regression in patients with Kaposi's sarcoma given intralesional injections of HCG. To further evaluate HCG's antitumor activity we conducted in vitro and clinical evaluations of HCG in acute myeloid leukemia (AML). In HL-60 leukemic cell lines, a 20-40% inhibition of cell density was demonstrated by trypan blue exclusion method at low concentrations of an HCG preparation (2 x 10(-3)-2 x 10(-2)). Similar concentrations also resulted in a reduction in the proportion of cells in G2M phase of the cell cycle, as well as enhanced differentiation compared to control cells. Fifteen patients with advanced AML with marrow blast counts >30%, and five with marrow blast counts between 10 and 26% were given daily subcutaneous injections of HCG 2-4 IU and oral levamisole 50 mg weekly. Five patients with absolute blast counts in the blood ranging from 0 to 3500/microl and percent blasts in the marrow ranging from 16 to 81% were observed to have no progressive increase in either marrow or peripheral blast counts for 70-121 days. One patient with a pretreatment blast count of 10% in the marrow, no circulating blasts and minor cytopenias had a decrease in marrow blasts to less than 5% which has persisted at 550 days. No significant improvement from baseline levels of neutrophils, hemoglobin or platelets were observed in any nl the patients treated. Increases in apoptotic cell death were observed in over 50% of patients' cells with some demonstrating peak levels similar to experiences in patients treated with DNA-damaging chemotherapy. A decreased expression of bcl-2 was seen in the majority of patients ranging from 6 to 62%. These new observations suggest that HCG preparations may inhibit leukemic cell growth through enhancement of cell death mechanisms and could be used in judicious combinations with other approaches. The results confirm the pro-apoptotic effects of HCG preparations reported in patients with Kaposi's sarcoma. Identification of the active component of HCG preparations and further understanding of its growth modulatory action will be important in its development as a clinically useful agent.
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Ahmed T, Ein S, Moore A. The role of peritoneal drains in treatment of perforated necrotizing enterocolitis: recommendations from recent experience. J Pediatr Surg 1998; 33:1468-70. [PMID: 9802792 DOI: 10.1016/s0022-3468(98)90476-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND/PURPOSE Intraperitoneal drains have been used in the treatment of perforated necrotizing enterocolitis (NEC), especially in infants less than 1,000 g, yet their role is still debated. The authors wished to examine their more recent experience in the treatment of NEC to make recommendations for operative management. METHODS The authors reviewed the records of all infants seen between 1989 and 1995 who had clinical and radiological evidence of NEC at the Hospital for Sick Children, Toronto, Ontario. One hundred sixty-seven infants were treated for NEC and 73 (44%) infants required surgical intervention. RESULTS Forty-five patients had perforated NEC; 23 were treated initially by peritoneal drainage and 22 by primary laparotomy. The 23 newborns who had peritoneal drainage were of significantly lower birth weight, and 19 (83%) of these infants required subsequent laparotomy for worsening disease. The overall mortality rate for perforated NEC was 36%. CONCLUSION Insertion of a peritoneal drain is still useful in resuscitating small critically ill infants with NEC; however, the majority of these infants will also require laparotomy.
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Ahmed T. Drugs Affecting Lipid Metabolism--XIII International Symposium. 30 May-3 June 1998, Florence, Italy. IDRUGS : THE INVESTIGATIONAL DRUGS JOURNAL 1998; 1:281-285. [PMID: 18465547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This meeting convened over four days in the historical city of Florence, Italy. It attracted around 2500 attendees mainly from academia and pharmaceutical companies but also included clinical cardiologists from around the world. The conference covered a wide range of topics in the field of heart disease and lipid lowering drugs in the plenary sessions, workshops, and over 300 posters. The plenary sessions and series of workshops entitled "Drugs affecting lipid metabolism" were well attended and stimulated much discussion. There was a noticeably high content of basic research in the workshops, particularly in the field of molecular biology, although clinical studies also made up a large part of the data.
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Ahmed T, Sumazaki R, Shin K, Nagai Y, Shibasaki M, Fuchs GJ, Takita H. Humoral immune and clinical responses to food antigens following acute diarrhoea in children. J Paediatr Child Health 1998; 34:229-32. [PMID: 9633968 DOI: 10.1046/j.1440-1754.1998.00223.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To investigate the effect of acute watery diarrhoea in children upon humoral immune responses to food antigens and the subsequent development of food allergy. METHODOLOGY Serum antibodies to cows' milk, beta-lactoglobulin, alpha-lactalbumin, bovine serum albumin and ovalbumin were measured in 30 children with acute diarrhoea in the acute phase and 1 month after recovery. The children were followed for 1 year to assess the development of food allergy. RESULTS IgG antibeta-lactoglobulin titres for the study group increased 1 month after recovery compared to the titres during the acute phase (P = 0.02). Antibody concentration for the other antigens studied did not rise. Four children developed positive IgE antibodies to one or more of the allergens after the diarrhoeal episode, although the titres were very low. None showed evidence of allergy to cows' milk or egg during the year-long follow-up. CONCLUSIONS Acute diarrhoea in children resulted in increased production of IgG antibody to beta-lactoglobulin and had a priming effect for development of positive IgE antibody to cows' milk. Clinical food allergy was not observed in any of the children during the year-long follow-up.
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Molinari JF, Campo C, Shakir S, Ahmed T. Inhibition of antigen-induced airway hyperresponsiveness by ultralow molecular-weight heparin. Am J Respir Crit Care Med 1998; 157:887-93. [PMID: 9517607 DOI: 10.1164/ajrccm.157.3.9708027] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Unfractionated heparin (UF-heparin) has been shown to prevent antigen-induced airway hyperresponsiveness (AHR), but it is ineffective when administered after the antigen challenge. We hypothesized that the failure of UF-heparin to modify postantigen AHR might depend on molecular weight. We therefore studied the effects of UF-heparin and three low-molecular-weight heparin fractions (medium-molecular-weight heparin [MMWH]; low-molecular-weight heparin [LMWH]; and ultralow-molecular-weight heparin [ULMWH]) on antigen-induced AHR and histamine release in bronchoalveolar lavage fluid (BALF). Specific lung resistance (SRL) was measured in 20 allergic sheep before, immediately after, and up to 2 h after challenge with Ascaris suum antigen. Airway responsiveness was expressed as the cumulative provocative dose of carbachol, in breath units, that increased SRL by 400% (PD400). PD400 was determined before and 2 h after antigen, both without and after treatment with aerosolized UF-heparin (1,000 U/kg) and various heparin fractions (0.04 mg/kg to 5 mg/kg) administered after the antigen challenge. Inhaled UF-heparin (n = 4), MMWH (n = 4), and LMWH (n = 6) failed to modify postantigen AHR when administered after the challenge. Only ULMWH (n = 6) inhibited postantigen AHR in a dose-dependent manner (percent protection ranged from 31% to 139%). In eight additional sheep, histamine in BALF was measured with a radioimmunoassay (RIA) before and after the segmental antigen challenge, without and after pretreatment with inhaled UF-heparin, LMWH, or ULMWH. Inhaled UF-heparin and LMWH inhibited antigen-induced histamine release as measured in BALF by 81% and 75%, respectively; whereas ULMWH was ineffective in this respect. We conclude that: (1) modification of antigen-induced AHR by fractionated heparins is molecular-weight dependent; and (2) only ULMWH attenuates AHR when administered after antigen challenge, via an unknown mast-cell-independent action.
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Ahmed T, Lutton JD, Feldman E, Tani K, Asano S, Abraham NG. Gene transfer of alpha interferon into hematopoietic stem cells. Leuk Res 1998; 22:119-24. [PMID: 9593468 DOI: 10.1016/s0145-2126(97)00133-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. IFN-alpha has been used in the management of leukemia, and gene transfer of the IFN-alpha gene into hematopoietic progenitor cells may have great potential for the treatment of chronic myelogenous leukemia (CML). Therefore, we examined the ability of adenovirus (Ad)-IFN-alpha gene construct to transfect normal bone marrow hematopoietic CD34+ stem cells and the production of IFN-alpha protein by these cells. Ad-cytomegalovirus (CMV) promoter-driven IFN-alpha at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture. Optimal transduction of CD34+ cells with the AdCMV-IFN-alpha construct was achieved using 120 plaque forming units (pfu). Flow cytometric determinations revealed that there was no significant difference in CD34+ cell viability for the 8 or 12-h transfection periods. Immunoassay of IFN-alpha produced by CD34+ cells shows that IFN-alpha levels increased several fold in transfected cells and this was not seen in CD34+ cells transfected with the heme oxygenase gene (HO-1). These in vitro data suggest that adenovirus-mediated gene transfer of IFN-alpha into hematopoietic stem cells can be achieved and that the IFN-alpha protein is produced by viable CD34 progenitor cells.
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Carere RG, Webb JG, Miyagishima R, Djurdev O, Ahmed T, Dodek A. Groin complications associated with collagen plug closure of femoral arterial puncture sites in anticoagulated patients. CATHETERIZATION AND CARDIOVASCULAR DIAGNOSIS 1998; 43:124-9. [PMID: 9488539 DOI: 10.1002/(sici)1097-0304(199802)43:2<124::aid-ccd2>3.0.co;2-c] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A retrospective study was conducted to determine the frequency and nature of groin complications when the Vasoseal (Datascope Corp., NJ) hemostasis device was used on 204 occasions to enable removal of the groin sheath in anticoagulated patients. The patients had undergone balloon angioplasty (53%), coronary stenting (20%), and diagnostic angiography (27%). Complications included vascular surgery in 5% including 2 embolized collagen plugs, failure to achieve hemostasis (2%), late external bleeding (2%), purulent discharge (1.5%), a minor ooze of blood (7%), hematomas >6 cm (6%), and hematomas < or = 6 cm (7%). One or more complications occurred with 64 of 204 (30.5%) uses. Multivariate analysis identified diagnostic angiography to be associated with a reduced risk of complications [odds ratio (OR) 0.25], while stent procedure (OR 2.7) and female gender (OR 2.5) were associated with increased risk. This complication rate is similar to other reported series except for a higher rate of vascular surgery. The high incidence of anticoagulation in our study patients (94%) may explain this difference. We recommend caution and adherence to the recommended technique when the device is used in anticoagulated patients.
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Datta K, Chin A, Ahmed T, Qing WG, Powell KL, Simhambhatla P, MacLeod MC, Stoica G, Kehrer JP. Mixed effects of 2,6-dithiopurine against cyclophosphamide mediated bladder and lung toxicity in mice. Toxicology 1998; 125:1-11. [PMID: 9585095 DOI: 10.1016/s0300-483x(97)00149-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
2,6-Dithiopurine (DTP) has been proposed as a possible chemopreventive agent because of its ability to react with electrophiles. Acrolein, an electrophilic metabolite of cyclophosphamide (CP) involved in the toxicities of this anticancer drug, can be scavenged by DTP. The present study examined the effect of DTP treatment on CP-mediated bladder and lung toxicity in male ICR mice. Mice fed a diet containing 4% DTP that were treated intraperitoneally (i.p.) with 350 mg/kg CP showed no significant bladder damage (measured as bladder blood content at 48 h) with respect to the group fed a control diet. DTP (50 and 100 mg/kg), given i.p. 0.5 and 7 h after the initial injection of CP, also prevented the bladder damage when compared with the group receiving CP alone. Surprisingly, although neither parenteral CP nor DTP alone caused any mortality at these doses, the combined treatment resulted in 67% mortality within 3 days. At 24 h after CP + DTP, blood urea nitrogen was elevated 6-fold and urine volumes decreased by 70%. Histopathological analyses revealed a diffuse myocardial degeneration and necrosis, severe granular degeneration in the liver, abundant cellularity and infiltrates in interalveolar spaces in the lung and swollen nephron epithelial cells with some necrosis. All mice survived treatment when the dose of CP was lowered to 250 and 25-75 mg/kg DTP was given i.p. 0.5 and 7 h after CP. These DTP regimens reduced the degree of CP-induced lung toxicity, measured by [3H]thymidine incorporation into lung DNA 7 days after CP, in a dose-dependent manner. DTP (75 mg/kg) also reduced CP-induced lung fibrosis estimated by lung hydroxyproline content 28 days after CP. Analyses of urine from mice given CP + DTP revealed large amounts of the metabolic product dithiouric acid, smaller amounts of the parent DTP and several smaller peaks. The major unique metabolite peak was collected and analyzed by mass spectrometry, but did not correspond to either acrolein-DTP or acrolein-dithiouric acid. Thus, either very small amounts of an acrolein adduct are generated, the adduct is broken down to an unidentified product, or the ability of DTP to prevent CP-induced lung and bladder damage is related to some other mechanism. The possibility that mercapturic acid metabolites of acrolein released the parent electrophile in the urine was not supported by the finding that probenecid did not prevent CP-induced bladder toxicity.
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239
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Obaid-ur-Rahman M, Ahmed T, Rahman S. Effects of socioeconomic factors, psychological stress, smoking, alcohol and caffeine on preterm delivery. PAKISTAN JOURNAL OF PHARMACEUTICAL SCIENCES 1998; 11:35-9. [PMID: 16414809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The relation between preterm birth and socioeconomic and psychological factors, smoking, alcohol and caffeine consumption are studied. Gestational age was determined from ultrasound and maternal dates. Adverse social circumstances are associated with preterm birth which inturn effects fetal growth.
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240
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Martinez-Salas J, Mendelssohn R, Abraham WM, Hsiao B, Ahmed T. Inhibition of allergic airway responses by inhaled low-molecular-weight heparins: molecular-weight dependence. J Appl Physiol (1985) 1998; 84:222-8. [PMID: 9451639 DOI: 10.1152/jappl.1998.84.1.222] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Inhaled heparin prevents antigen-induced bronchoconstriction and inhibits anti-immunoglobulin E-mediated mast cell degranulation. We hypothesized that the antiallergic action of heparin may be molecular weight dependent. Therefore, we studied the effects of three different low-molecular-weight fractions of heparin [medium-, low-, and ultralow-molecular-weight heparin (MMWH, LMWH, ULMWH, respectively)] on the antigen-induced acute bronchoconstrictor response (ABR) and airway hyperresponsiveness (AHR) in allergic sheep. Specific lung resistance was measured in 22 sheep before and after airway challenge with Ascaris suum antigen, without and after pretreatment with inhaled fractionated heparins at doses of 0.31-5.0 mg/kg. Airway responsiveness was estimated before and 2 h postantigen as the cumulative provocating dose of carbachol in breath units that increased specific lung resistance by 400%. All fractionated heparins caused a dose-dependent inhibition of ABR and AHR. ULMWH was the most effective fraction, with the inhibitory dose causing 50% protection (ID50) against ABR of 0.5 mg/kg, whereas ID50 values of LMWH and MMWH were 1.25 and 1.8 mg/kg, respectively. ULMWH was also the most effective fraction in attenuating AHR; the ID50 values for ULMWH, LMWH, and MMWH were 0.5, 2.5, and 4.7 mg/kg, respectively. These data suggest that 1) fractionated low-molecular-weight heparins attenuate antigen-induced ABR and AHR; 2) there is an inverse relationship between the antiallergic activity of heparin fractions and molecular weight; and 3) ULMWH is the most effective fraction preventing allergic bronchoconstriction and airway hyperresponsiveness.
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241
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Ahmed T, Fuchs GJ. Gastrointestinal allergy to food: a review. JOURNAL OF DIARRHOEAL DISEASES RESEARCH 1997; 15:211-23. [PMID: 9661317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Gastrointestinal food allergy still poses a challenge to the clinician because of its variable symptomatology and lack of reliable diagnostic tests. Its prevalence is estimated at 2 approximately 5%, higher in children than in older age-groups. Allergy to food usually diminishes with advancing age. Although a wide variety of foods can cause allergic reactions, cow's milk is the most common cause of food allergy in infants and young children. Depending upon the speed of onset of symptoms, immediate and delayed types of food allergy have been described. Gastrointestinal symptoms in food allergy have been explained by alterations in transport across the intestinal wall (increased secretory and/or decreased absorptive functions), increased permeability, and motility of the intestine. The exact pathogenesis of food allergy is still not clear. However, immediate type of food allergy is believed to be mediated by type I hypersensitivity reaction, involving mast cells and food-specific IgE antibodies. The diagnosis of food allergy is based upon a favorable response to an elimination diet and a response to a challenge with the suspected food. The condition is treated by eliminating the allergenic food from diet for as long as 9-12 months in case of cow's milk allergy. While exclusive breast-feeding for the initial four months or more reduces the chances of development of food allergy, the role of diet restrictions in the mother in reducing the incidence of food allergy in the infant is controversial. Data on food allergy from developing countries are limited. This may be due to lack of diagnosis or less attention given to the condition relative to other diseases including infectious diarrheas and acute respiratory infections. The role of cow's milk allergy in the pathogenesis of persistent diarrhoea, a major problem in the developing world, remains speculative. Frequent intestinal infections and reduced secretory IgA, which are associated with malnutrition, alter intestinal permeability and result in an increased uptake of food antigens. The increased antigenic load combined with factors such as an atopic predisposition may initiate an abnormal mucosal immune response resulting in chronic enteropathy.
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242
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Nusier SQ, Newaz GM, Chaudhury ZA, Ahmed T. Effect of Holding Time on Damage State in a Thermal Barrier Coating. COMPOSITES AND FUNCTIONALLY GRADED MATERIALS 1997. [DOI: 10.1115/imece1997-0692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
Abstract
Abstract
Spallation is a major failure condition experienced by thermal barrier coatings (TBCs) subjected to thermal and mechanical loads. Although evidence of spallation is substantiated and mechanistic models to describe the failure condition is prevalent in literature, the progressive nature of damage evolution leading to spallation has not been addressed adequately. In this study, the effect of holding time on damage evolution in partially stabilized zirconia TBC on Nickel-based single crystal superalloy, Rene N5, was studied. Button specimens with Electron Beam - Physical Vapor Deposition (EB-PVD) TBC coating were thermally cycled. The bond coat was PtAl. Two different thermal cycle profiles were used to assess damage development. Damage state was tracked using microscopy and thermal wave imaging technique on samples subjected to a series of thermal cycles. It was found that if the sum of hold times at the same peak temperature are kept constant for two different thermal cycles profiles, similar damage states can be obtained.
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243
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Feldman E, Ahmed T, Lutton JD, Farley T, Tani K, Freund M, Asano S, Abraham NG. Adenovirus mediated alpha interferon (IFN-alpha) gene transfer into CD34+ cells and CML mononuclear cells. Stem Cells 1997; 15:386-95. [PMID: 9323802 DOI: 10.1002/stem.150386] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Gene transfer or gene therapy has advantages in the treatment of a variety of disorders due to its selective expression within specific mammalian cells. Interferon-alpha (IFN-alpha) has been used in the management of leukemia but its diverse adverse activities with multiple potential side effects, possibly unrelated to therapeutic targets, may negatively influence the ability of IFN-alpha to treat this disorder. Therefore, we examined the ability of adenovirus (Ad)-IFN-alpha gene construct to transfect normal (CD34+ cells) and chronic myelogenous leukemia (CML) bone marrow mononuclear cells (BMMNC) and the transient overexpression of IFN-alpha in these cells. Ad-cytomegalovirus promoter driven IFN-alpha (AdCMV-IFN-alpha) at multiple doses was assessed to transfect highly purified CD34+ cells in liquid culture, and optimal transduction of CD34+ cells was achieved using 120 plaque forming units. Flow cytometric determinations revealed that there was no significant difference in cell viability for the 4 h or 24 h transfection periods. Immunoassay of IFN-alpha produced by CD34+ cells shows that IFN-alpha levels increased several fold in transfected cells. Transient expression of the IFN-alpha gene did not suppress proliferation of CD34+ progenitors as indicated by BFU-E or colony forming units-granulocyte-macrophage (CFU-GM) growth. Reverse transcriptase/polymerase chain reaction analysis of RNA from CD34+ harvested CFU-GM progenitor cells demonstrated transient IFN-alpha mRNA expression. Similarly, CML BMMNC were transfected with AdCMV-IFN-alpha under similar conditions as described for CD34+ cells. BMMNC cells exposed to adenovirus for 24 h and 48 h were found to express IFN-alpha at a substantial level. This in vitro data suggest that Ad-mediated gene transfer of IFN-alpha into hematopoietic stem cells can be achieved and that the IFN-alpha gene can be translated into its specific mRNA in CD34 progenitor cells.
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MESH Headings
- Adenoviridae/genetics
- Antigens, CD34/genetics
- Bone Marrow Cells/cytology
- Colony-Forming Units Assay
- Cytomegalovirus/genetics
- DNA, Complementary/analysis
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Dose-Response Relationship, Drug
- Gene Transfer Techniques
- Genetic Vectors
- Humans
- Interferon-alpha/genetics
- Interferon-alpha/therapeutic use
- Interferon-alpha/toxicity
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy
- Leukocytes, Mononuclear/drug effects
- Leukocytes, Mononuclear/physiology
- RNA, Messenger/analysis
- RNA, Messenger/genetics
- Stem Cells/drug effects
- Stem Cells/immunology
- Stem Cells/physiology
- Transfection
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244
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Haq SA, Alam MN, Hossain SM, Ahmed T, Tahir M. Value of clinical features in the diagnosis of enteric fever. BANGLADESH MEDICAL RESEARCH COUNCIL BULLETIN 1997; 23:42-6. [PMID: 9465434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There is no objective data on the value of individual clinical symptoms or signs in the diagnosis of enteric fever in a febrile patient. The purpose of the study was to assess the value of some clinical and simple laboratory features in the diagnosis of enteric fever. One hundred & six patients with microbiologically confirmed enteric fever and 170 patients with other established febrile illnesses were included in the evaluation. History of stepladder pattern of rise of temperature, loose motions, relative bradycardia and coated tongue proved to be powerful markers of enteric fever with high specificity (100%, 94.71%, 94.71%, 94.12% respectively), positive and negative predictive values. Headache, hepatomegaly and splenomegaly were moderately powerful. ESR and WBC count appeared to have little value in the diagnosis of enteric fever. Pattern of onset and loose motions did not discriminate between typhoid and paratyphoid fever. Most of these patients had illness persisting beyond one week by which viral infections and infectious enterocolitides were largely excluded. Elucidation of power of these markers in distinguishing enteric fever from other febrile illnesses with the help of better designed prospective studies would lessen our dependence on expensive and time consuming laboratory investigations.
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245
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Farley TJ, Rooney W, Kuhns E, Ahmed T, Preti RA. An intralaboratory quality control program for quantitation of CD34+ cells by flow cytometry. JOURNAL OF HEMATOTHERAPY 1997; 6:303-8. [PMID: 9377068 DOI: 10.1089/scd.1.1997.6.303] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study was undertaken to develop a quality control protocol to monitor instrument, operator, and CD34 assay performance. A dual level control system was established by cryopreserving aliquots of cells from peripheral blood progenitor cell (PBPC) collections exhibiting different percentages of CD34+ cells. Twenty-five samples from each control specimen were assayed to establish a control range (mean +/- 2 SD). Levey-Jennings graphs were prepared for each control specimen to plot multiple measurements of CD34%. No significant differences were observed between fresh or cryopreserved PBPC aliquots in terms of light scatter properties or CD34 antigen density within the gated cell population. Cryopreserved PBPC samples are ideal for serving as a positive methodology control for daily CD34 analysis. Furthermore, such a system can help identify problems with assay reagents, sample preparation technique, or incorrect data analysis.
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246
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Chaudhury Z, Newaz G, Nusier S, Ahmed T. Interfacial damage in EB-PVD thermal barrier coatings due to thermal cycling. MATERIALS SCIENCE AND ENGINEERING: A 1997; 231:34-41. [DOI: 10.1016/s0921-5093(97)00093-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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247
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Ahmed T, Sumazaki R, Nagai Y, Shibasaki M, Takita H. Immune response to food antigens: kinetics of food-specific antibodies in the normal population. ACTA PAEDIATRICA JAPONICA : OVERSEAS EDITION 1997; 39:322-8. [PMID: 9241893 DOI: 10.1111/j.1442-200x.1997.tb03745.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The role of food-specific antibodies in the pathogenesis of food allergy is controversial. The first step in solving this controversy may be the assessment of antibody response to food antigens in the normal population. Most of the existing data in this field come from studies that used assays of different standards. This study investigated food-specific antibodies in the normal population using standardized assays. Normal levels of antibody titers were also derived for use as reference. Two hundred and eight individuals from different age groups participated. Immunoglobulin G (IgG) antibodies to cow's milk and its component proteins, and to hen's egg ovalbumin, IgA and IgM antibodies to beta-lactoglobulin and ovalbumin were measured by enzyme-linked immunosorbent assay. The sepharose-radioallergosorbent test was used to measure IgE antibodies to cow's milk and ovalbumin. Titers of IgG antibodies to cow's milk and its component proteins revealed an age-related trend, peaking in the 5 months-1 year age group and then decreased to negligible values in adults. A similar trend was observed with IgG anti-ovalbumin antibodies. Temporal association was less evident for antibodies of other classes. Only six subjects had positive IgE antibodies to cow's milk, while none had positive IgE anti-ovalbumin antibody. The prevalences of IgG antibodies to cow's milk, its component proteins, and ovalbumin are influenced by age and feeding habits. Cross-reactivity to related food antigens is common. The presence of IgE antibodies to food antigens is not a physiological phenomenon.
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248
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Ahmed T, Campo C, Abraham MK, Molinari JF, Abraham WM, Ashkin D, Syriste T, Andersson LO, Svahn CM. Inhibition of antigen-induced acute bronchoconstriction, airway hyperresponsiveness, and mast cell degranulation by a nonanticoagulant heparin: comparison with a low molecular weight heparin. Am J Respir Crit Care Med 1997; 155:1848-55. [PMID: 9196085 DOI: 10.1164/ajrccm.155.6.9196085] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Inhaled heparin prevents antigen-induced bronchoconstriction and inhibits anti-IgE-mediated mast-cell degranulation. We hypothesized that the antiallergic action of heparin may be dependent on molecular weight and related to its nonanticoagulant properties. Therefore, in the present investigation we studied the effects of a nonanticoagulant fraction of heparin (LA-heparin) on antigen-induced bronchoconstriction, airway hyperresponsiveness (AHR), and mast-cell degranulation, and compared its antiallergic activity with that of a low molecular weight heparin (LMW-heparin, fragmin). Specific lung resistance (SRL) was measured in 15 sheep before, immediately after, and serially for as long as 2 h after airway challenge with Ascaris suum antigen, without and after pretreatment with inhaled fractionated heparins at doses of 2.5 and 5 mg/kg. Airway responsiveness was estimated before, and 2 h after antigen as the cumulative provocating dose (PD400) of carbachol in breath units, which increased SRL by 400% (one breath unit was defined as one breath of 1% carbachol solution). LA-heparin caused a dose-dependent inhibition of antigen-induced bronchoconstriction, and a 5-mg/kg nebulized dose caused a 67% inhibition of allergic bronchoconstriction, whereas a 2.5-mg/kg dose was ineffective (20% inhibition). Inhaled fragmin was more potent than LA-heparin, as shown by 84% (2.5 mg/kg) and 82% (5 mg/kg) inhibition of allergic bronchoconstriction. Fragmin (5 mg/kg) also attenuated the postantigen AHR, whereas LA-heparin was ineffective. In vitro, preincubation with both LA-heparin and fragmin inhibited the anti-IgE-induced degranulation of rat peritoneal mast-cells in a dose-dependent fashion. LA-heparin was fourfold more potent than fragmin, with IC50 of 80 and 320 microg/ml, respectively. These data suggest that: (1) fractionated heparins attenuate antigen-induced acute bronchoconstriction, (2) nonanticoagulant fractions mediate the antiallergic activity of inhaled heparin, and (3) antiallergic activity of nonanticoagulant heparin and LMW-heparin may be related to prevention of mast-cell degranulation.
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Vose JM, Pandite AN, Beveridge RA, Geller RB, Schuster MW, Anderson JE, LeMaistre CF, Ahmed T, Granena A, Keating A, Fernandez Ranada JM, Stiff PJ, Tabbara I, Longo W, Copelan EA, Nichols C, Smith A, Topolsky DL, Bierman PJ, Lebsack ME, Lange M, Garrison L. Granulocyte-macrophage colony-stimulating factor/interleukin-3 fusion protein versus granulocyte-macrophage colony-stimulating factor after autologous bone marrow transplantation for non-Hodgkin's lymphoma: results of a randomized double-blind trial. J Clin Oncol 1997; 15:1617-23. [PMID: 9193361 DOI: 10.1200/jco.1997.15.4.1617] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE A phase III trial to compare PIXY321 with granulocyte-macrophage colony-stimulating factor (GM-CSF) following high-dose therapy and autologous bone marrow transplant (ABMT) was conducted to evaluate the time to hematopoietic recovery. PATIENTS AND METHODS One hundred seventy-seven patients with non-Hodgkin's lymphoma (NHL) receiving ABMT were randomized to receive either PIXY321 750 micrograms/m2/d divided into two subcutaneous (SC) doses or GM-CSF 250 micrograms/m2/d as a 2-hour intravenous (IV) infusion starting on day 0 post-ABMT for a maximum of 28 days. RESULTS The median time to reach an absolute neutrophil count (ANC) > or = 500/microL in the PIXY321 group was 17 days versus 19 days in the GM-CSF group (P = .07) and the median time to reach platelet transfusion independence in the PIXY321 group was 25 days versus 23 days in the GM-CSF group (P = .30). The toxicity profiles of the two agents appeared to be equivalent with the exception of more patients in the PIXY321 group with a rash (64%) compared with the GM-CSF group (48%) (P = .028). A logistic regression model identified the use of a non-total-body irradiation (TBI) regimen and/or receipt of unpurged marrow and a body-surface area greater than 2.0 m2 as predictive of faster neutrophil engraftment, and those three factors, as well as the receipt of < or = two prior chemotherapy regimens as predictive for rapid platelet engraftment. CONCLUSION There was a trend toward a slight improvement in neutrophil engraftment post-ABMT with the PIXY321 administered by an SC route compared with GM-CSF administered by an IV route. However, no differences could be identified between the two agents with respect to the time to platelet transfusion independence. Patient, regimen, and graft characteristics were most predictive of the engraftment tempo.
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250
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Feldman EJ, Seiter K, Damon L, Linker C, Rugo H, Ries C, Case DC, Beer M, Ahmed T. A randomized trial of high- vs standard-dose mitoxantrone with cytarabine in elderly patients with acute myeloid leukemia. Leukemia 1997; 11:485-9. [PMID: 9096687 DOI: 10.1038/sj.leu.2400623] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
To evaluate the efficacy and tolerability of a high-dose mitoxantrone-based induction regimen without consolidation therapy in patients over age 60 with newly diagnosed acute myeloid leukemia (AML), 54 patients aged 60-83 were randomized to receive mitoxantrone, either 80 mg/m2 on day 2, or 12 mg/m2 on days 1-3 in addition to cytarabine, 3 g/m2 on days 1-5. Significant toxicity included mucositis, diarrhea, transient hyperbilirubinemia and cardiac events. No difference in toxicity was observed between the two dosage regimens. Overall, 27 patients achieved a complete remission (CR), 16/28 CR in the high-dose and 11/25 in the lower-dose group. Induction death occurred in 11 patients, three in the high-dose and eight in the low-dose arm. Actuarial median survival was 6 months for the low-dose and 9 months for the high-dose group, and the respective relapse-free survival is 3 and 5 months. The observed differences in outcome were not statistically significant. patients in both arms of this trial, who received no consolidation, appear to have response and survival rates equivalent to those of standard-dose induction with repetitive consolidation. This approach might offer elderly patients equivalent outcome with fewer days of treatment, presumably enhancing quality of life.
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