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Biomedical subjects

S Singhal

Publications and source records attributed to S Singhal.

At least 91 records · Page 5Linked to original sources
PubMed1999

Complete remission rate and outcome after intensive treatment of 177 patients under 75 years of age with IgG myeloma defining a circumscribed disease entity with a new staging system.

Because the presence of IgG paraprotein in the blood is clear cut, it makes IgG myeloma a more circumscribed disease than myeloma as a whole in which to study treatment efficacy, particularly relating to complete remission (CR). Between May 1989 and December 1997, 177 consecutive patients with IgG myeloma who were <75 years old were seen, of whom 153 entered a sequential therapy (ST) programme of initial courses of C-VAMP infusional chemotherapy (IC), high-dose treatment (with or without stem cell rescue) (119 patients) and maintenance interferon (87 patients). 74/153 (48.4%) patients entered CR. Median overall survival (OS) and event-free survival (EFS) were 4.9 and 2.1 years, respectively. Multivariate analysis at presentation showed OS was significantly prolonged for beta2M <2.7 mg/l and age 8.5 g/dl predicted for longer EFS. For CR patients, age <median 51 years, absence of Bence-Jones proteinuria (BJP), male sex and white blood cells (WBC) <7 x 109/l predicted for a longer OS. Longer length of first CR was predicted by absence of BJP at presentation (P = 0.03) and fewer than five courses of IC (P = 0.02) to attain CR. We have therefore been able to refine the use of ST in IgG myeloma, redefine CR as a 'macro' endpoint, and propose a new staging system for IgG myelomas. Analysis of 41 comparable IgA patients showed IgG to be a distinct entity.

Adult↗
PubMed1999

An evaluation of the no-scalpel vasectomy technique.

OBJECTIVE: To evaluate the magnitude and range of complications encountered during no-scalpel vasectomy (NSV) and to identify any limiting factor or contraindication to NSV. SUBJECTS AND METHODS: A total of 4255 men visiting a family welfare clinic of a city hospital in Delhi, India, or outpatients of the surgery department, opted for NSV; 4253 procedures were performed from September 1989 to December 1997, with two not performed because of technical difficulties. The success and complication rates were recorded. RESULTS: The complication rates with NSV were surprisingly low; seven complications were encountered, comprising two small haematomas (0.047%), three painful nodules (0.07%), three wound infections (0.07%) and two vasal fistulae, a complication not previously described. A meticulous procedure should avoid this last complication. The mean duration of NSV was 9.5 min. CONCLUSION: NSV is a refined and rapid technique of vasectomy with an extremely low complication rate. Being a minimally invasive procedure, it allays the fear of incision commonly encountered in men choosing vasectomy.

Contraindications↗
PubMed1999

Fungal infection and liposomal amphotericin B (AmBisome) therapy in liver transplantation: a 2 year review.

We reviewed the use of liposomal amphotericin B in 30 patients receiving therapy following liver transplantation over a 2 year period. Five of these patients were treated for presumed invasive aspergillosis: four of them died despite therapy, each having combined renal and respiratory failure at the time of diagnosis of presumed aspergillosis. Post-mortem examination of three of these patients confirmed the diagnosis of aspergillosis. Twenty-five patients were treated empirically; 11 died and supportive evidence for invasive fungal infection following commencement of therapy was found in only one case. Following liver transplantation, the use of liposomal amphotericin B following confirmation of aspergillus infection or for empirical therapy is of uncertain value, and strategies based on selective prophylaxis for high-risk cases may be preferable.

Amphotericin B↗
PubMed1999

Long-term outcome of adult acute leukemia patients who are alive and well two years after allogeneic bone marrow transplantation from an HLA-identical sibling.

We studied the long-term outcome of 136 adults with acute leukemia (age 15-48 years at transplant, median 28; 112 myeloid, 22 lymphoblastic, 2 undifferentiated) who were alive in continuous remission two years after allografting from HLA-identical sibling donors. Six relapsed 25-46 months (median 30) after BMT. Fourteen (10%) died of non-relapse causes (12 transplant-related and 2 unrelated) 24-140 months (median 73) after BMT; mainly due to complications of chronic GVHD (8 infections, 3 secondary malignancies). One hundred and seventeen (86%) patients are alive in remission 25-226 months (median 103) after BMT; 116 (85%) in continuous remission. Eight survivors have symptomatic chronic GVHD requiring therapy (Karnofsky scores 60-90%, median 80%). The majority of those without chronic GVHD have Karnofsky scores of 100%. The 10-year probabilities of survival, toxic death, and relapse (from the 2-year mark) are 81%, 13%, and 5%. Twenty-two (19%) survivors had creatinine levels of > 110 mumol/L (one more than double), and 11 (9%) had bilirubin levels of > 17 mmol/L (one more than double) at the last follow-up. The absence of chronic GVHD at the 2-year mark (RR 3.5, P = .004), and female sex (RR 2.9, P = .04) influenced overall survival favorably, and the absence of chronic GVHD at the 2-year mark (RR 8.1, P = .001) influenced toxic death favorably. We conclude that patients with acute leukemia who are alive and well without chronic GVHD two years following an allograft have a high probability of being cured, whereas patients with active chronic GVHD requiring immunosuppression continue to be at risk of non-relapse death. The incidence of long-term liver and kidney dysfunction measured by serum bilirubin and creatinine is low.

Acute Disease↗
PubMed1999

Long-term follow-up of relapsed acute leukemia treated with immunotherapy after allogeneic transplantation: the inseparability of graft-versus-host disease and graft-versus-leukemia, and the problem of extramedullary relapse.

Long-term outcome of 23 acute myeloid (AML, n=16) or lymphoblastic (ALL, n=7) leukemia patients who had received immunotherapy for treatment of persistent or recurrent disease 1.5-26 (median 4) months after allogeneic transplantation was studied to determine eventual survival. Immune manipulation comprised donor leukocyte infusion (n=18), interferon-alpha2b and/or interleukin-2 (n=15), and cyclosporine withdrawal (n=11) in various combinations. Graft-versus-host disease (GVHD) developed in 12 patients. Thirteen of 20 evaluable patients responded; 6 relapsing again. Eight patients died of toxicity, and 10 of progressive disease at 3-206 weeks (median 11). Five patients (3 AML, 2 ALL) are alive in remission with GVHD 2-46 months (median 23) after immunotherapy with Karnofsky scores of 70-100% (median 80). The overall survival of the whole group is 1-206 weeks (median 12), with an actuarial survival of 22% at 2 years. The development of GVHD was associated with superior survival in multivariate analysis (P=.007). Seven patients received immunosuppression because of the severity of GVHD (grade III/IV acute or extensive chronic): 3 died of GVHD, 3 improved but relapsed concomitantly, and 1 is alive in remission with extensive chronic GVHD. Four episodes of extramedullary relapse (granulocytic sarcomas) were seen in 3 patients with AML whose marrow remained in remission. We conclude that GVHD appears to be inseparable from graft-versus-leukemia in relapsed acute leukemia patients undergoing immunotherapy with a high proportion of patients dying due to toxicity or progressive disease, and isolated extramedullary relapse seems to be unusually common.

Acute Disease↗
PubMed1999

The impact of karyotype on remission rates in adult patients with de novo acute myeloid leukemia receiving high-dose cytarabine-based induction chemotherapy.

One hundred and twenty-eight patients aged 15 years or over (median 34) with de novo acute myeloid leukemia (AML) received 2- or 3-drug induction chemotherapy comprising 5 days of daily high-dose cytarabine (2 g/m2 q12h) and etoposide (100 mg/m2), without (n=62, 1985-90, protocol BF11) or with (n=66, 1990-97, protocol BF12) daily 5 mg/m2 anthracycline (61 idarubicin, 5 mitoxantrone). Twelve patients with t(15;17) were not included. Evaluable karyotypes were obtained in 110 (86%): 30 (27%) favorable, 60 (55%) intermediate, and 20 (18%) adverse. Three patients dying during chemotherapy were inevaluable. Eighty-four (67%) patients remitted with one cycle, and the overall complete remission (CR) rate was 72%. CR rates were comparable for patients with and without evaluable karyotypes. CR rates with BF11 (64% after one cycle; 72% overall) and BF12 (70% after one cycle; 72% overall) were comparable (P=.4 and 1.0 respectively). CR rates after one cycle (86%, 61% and 55%; P=.03) as well as overall CR rates (90%, 69% and 55%; P=.02) were significantly different for patients with favorable, intermediate and adverse karyotypes respectively. In Cox analysis, the karyotype was the only factor found to influence CR independently. We conclude that the karyotype of the leukemic clone is the most important determinant of response to high-dose cytarabine-based induction chemotherapy in AML. The addition of idarubicin to high-dose cytarabine and etoposide does not appear to improve CR rates. A different treatment strategy may be needed to improve CR rates for patients with non-favorable karyotypes.

Acute Disease↗
PubMed1998

Identification of new nonrandom translocations in multiple myeloma with multicolor spectral karyotyping.

Multicolor spectral karyotyping (SKY) was performed on bone marrow samples from 50 patients with multiple myeloma (MM) in anticipation of discovering new previously unidentified translocations. All samples showed complex karyotypes with chromosome aberrations which, in most cases, were not fully characterized by G-banding. Patients of special interest were those who showed add(14)(q32), add(8)(q24) and those whose G-banding karyotypes showed poor chromosome morphology. Three new recurring chromosome translocations not previously reported in MM were identified. Two of the translocations involve recurring aberrations at band 14q32.3, the site of the IgH locus, with different exchange partners. The most frequently recurring rearrangement was a subtle translocation at 14q32.3 designated as a t(14;16)(q32;q22 approximately 23), which was identified in six patients. A second and larger translocation at 14q32, identified in two patients, was designated as a t(9;14)(p13;q32), previously associated with Waldenstrom's macroglobulinemia and lymphoplasmacytoid lymphoma. A third translocation, identified in two patients, involved a whole-arm t(6;8)(p10;q10) translocation. The SKY technique was able to refine the designations of over 156 aberrations not fully characterized by G-banding in this study and resolved additional chromosome aberrations in every patient studied except two. The t(14;16)(q32;q22 approximately 23) identified by SKY in this study suggests this may be a frequent translocation in MM associated with complex karyotypes and disease progression. Therefore, the SKY technique provides a useful adjunct to routine G-banding and fluorescence in situ hybridization studies in the cytogenetic analysis of MM.

Chromosomes, Human, Pair 14↗
PubMed1998

Identification of patients who may benefit from prophylactic immunotherapy after bone marrow transplantation for acute myeloid leukemia on the basis of lymphocyte recovery early after transplantation.

Two hundred and one patients (median age, 29 years) with acute myeloid leukemia (AML) underwent bone marrow transplantation (BMT) from HLA-identical sibling donors after conditioning with melphalan-total-body irradiation (TBI) (57%), cyclophosphamide-TBI (35%), or chemotherapy alone (8%). Graft-versus-host disease (GVHD) prophylaxis included cyclosporine alone (68%), cyclosporine-methotrexate (26%), or T-cell depletion (6%). The probability of relapse was calculated as a function of the absolute lymphocyte count (10(9)/L) on days 27 to 30 posttransplant (<0.1 v >/=0.1, <0.2 v >/=0.2, and <0.3 v >/=0.3). In each of these 12 comparisons, the probability of relapse was higher for the group with the lower lymphocyte count. Because the difference was most significant (P = .004) for an absolute lymphocyte count of <0.2 on day 29 (3-year relapse probability, 42%) versus >/= 0.2 (16%), this variable was included in a Cox model to determine factors independently affecting relapse. Multivariate analysis showed that conditioning regimens other than melphalan-TBI, a low lymphocyte count on day 29, French-American-British (FAB) subtypes M4-7, and a nucleated cell dose of > 2.42 x 10(8)/kg was associated with a higher risk of relapse. We conclude that slow lymphocyte recovery after allogeneic BMT, to < 0.2 x 10(9)/L 29 days in this analysis, appears to be associated with a higher risk of relapse in patients with AML. This group of patients may benefit from posttransplant immune manipulations such as abbreviated GVHD prophylaxis, or donor cell or cytokine administration to enhance graft-versus-leukemia reactions to reduce relapse.

Acute Disease↗
PubMed1998

Salvage autologous or allogeneic transplantation for multiple myeloma refractory to or relapsing after a first-line autograft?

Forty-two patients allografted for multiple myeloma after not having attained at least a partial remission (n = 19) or after having experienced disease progression (n = 23) following one autograft were compared with 42 pair-matched controls who underwent salvage autotransplantation under identical conditions. Autografted controls were matched closely for albumin, C-reactive protein, creatinine, disease sensitivity, duration of standard therapy prior to the first transplant, Ig isotype, karyotype, LDH, and response to the first transplant, but, in comparison to allografted patients, were older, had higher beta2-microglobulin, and had a shorter interval between the two transplants. The complete remission rate was 41% after allogeneic and 33% after autologous transplantation (P = NS). The 3-year probability of event-free survival was comparable for the two groups (25 +/- 8% after autografting and 20 +/- 8% after allografting). The 3-year probability of survival was significantly higher after autologous transplantation (54 +/- 8% vs 29 +/- 9%; P = 0.01). Twenty-one patients in the autograft group were alive 11-59 months (median 32) following the second transplant, while 15 patients in the allograft group were alive at 10-53 months (median 20). The 3-year probability of disease progression was significantly lower after allogeneic transplantation (31 +/- 10% vs 72 +/- 9%, P = 0.03). The 1-year probability of transplant-related mortality was significantly higher after allografting (43 +/- 8% vs 10 +/- 5%; P = 0.0001). We conclude that while autografting appears to be superior to allografting for salvage therapy of myeloma persisting or relapsing after one previous autotransplant in terms of overall survival, event-free survival is comparable due to significantly lower disease progression after allografting. Reduction in allograft-related toxicity can potentially improve the results of allogeneic transplantation significantly.

Adult↗
PubMed1998

Red cell fragmentation (schistocytosis) after bone marrow transplantation.

Red cell fragmentation is often the earliest sign of thrombotic microangiopathy. Days +14, +28 and +42 blood films from 58 allograft and 32 autograft recipients were reviewed blind to determine the incidence and severity of schistocytosis (the number of fragmented red cells per 1000 red cells expressed as a percentage). Schistocytosis was graded as mild (<1%), moderate (1-1.9%) or severe (> or =2%). Schistocytes were seen in 99% of day 14 films (0.1-3.0%, median 0.4%), 97% of day 28 films (0.1-3.2%, median 0.4%), and 98% of day 42 films (0.1-4.3%, median 0.5%). Nine patients (10%) had severe fragmentation and 20 patients (22%) had moderate fragmentation at some time or the other. The difference in the extent of fragmentation between the days was not significant. Allogeneic BMT was associated with more extensive fragmentation than autologous transplantation on day 28 (P = 0.008) and day 42 (P = 0.02). Age, conditioning regimen and diagnosis had no influence. None of the patients followed-up for 6 months after transplant developed full-blown thrombotic microangiopathy. The occasional patient showing mild clinical and laboratory features of hemolysis responded well to adjustment of fluid balance and cyclosporine dose where applicable. Our data indicate that mild red cell fragmentation is a common morphologic finding after transplantation with no clinical significance in the absence of other clinical and laboratory findings suggestive of thrombotic microangiopathy, although patients with moderate or severe fragmentation should be monitored closely.

Adolescent↗
PubMed1998

Graft-versus-myeloma.

Whereas patients with multiple myeloma continue to relapse after autologous transplantation and are unlikely to be cured, the probability of progression is less after allogeneic transplantation and a proportion of patients may be cured. This is attributable to an immunologically mediated graft-versus-myeloma (GVM) effect which is akin to the well-known graft-versus-leukemia effect. The available clinical and experimental evidence strongly support the existence of GVM, but it is not known whether GVM is separable from graft-versus-host disease (GVHD) in practice. The best way to exploit GVM reactions is unclear, and the morbidity and mortality associated with GVHD undermine long-term survival. There is usually a time lag of a few weeks between immune intervention and disease response. There is a propensity for extramedullary disease recurrence in patients whose marrow disease is controlled with immunologic manipulation. Exploration of GVM outside conventional allogeneic transplantation or after autologous transplantation is necessary to increase the number of patients likely to benefit from this phenomenon and to make it safer. This article reviews the currently available literature on the subject.

Bone Marrow Transplantation↗
PubMed1998

Comparable engraftment kinetics following peripheral-blood stem-cell infusion mobilized with granulocyte colony-stimulating factor with or without cyclophosphamide in multiple myeloma.

PURPOSE: To compare, in the setting of tandem autotransplantations for multiple myeloma (MM), two established methods of peripheral-blood stem-cell (PBSC) procurement with chemotherapy or hematopoietic growth factor alone. PATIENTS AND METHODS: Between June 1994 and July 1995, 44 patients with MM were randomized to PBSC mobilization with either granulocyte colony-stimulating factor (G-CSF) 16 microg/kg (group 1; n = 22) or high-dose cyclophosphamide (HDCTX) 6 g/m2 plus G-CSF 5 microg/kg (group 2; n = 22). All 44 patients received melphalan 200 mg/m2 with their first autograft and 32 patients proceeded to a second transplantation. RESULTS: Group 2 required a significantly longer time interval for completion of PBSC collection than group 1 (median, 22 v 8 days; P = .0001), greater frequency of hospitalization (100% v 32%; P = .0001), and increased transfusion of platelets (86% v 18%; P = .0001) and packed RBCs (86% v 55%; P = .02). Likewise, the incidence of fever and pneumonia/sepsis were higher in group 2 (P = .02 and P = .04, respectively). Surprisingly, despite greater CD34 cell quantities infused in group 2, median recovery times of granulocytes (both > 500/microL and 2,500/microL) and platelets (both > 50,000/microL and > 100,000/microL) were similar (all P > .7). Posttransplant toxicities were also similar. CONCLUSION: Compared with HDCTX plus G-CSF, high-dose G-CSF alone is associated with lower morbidity, shorter duration of PBSC mobilization, and comparable hematopoietic recovery after transplantation, which should result in significant cost reduction. Considering the relatively limited antitumor activity of HDCTX (10% with > or = 50% tumor cytoreduction), PBSC mobilization with HDCTX should be limited to selected patients with persistent MM despite induction chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Educational status and dietary fat and anti-oxidant intake in urban subjects.

To assess correlation of dietary atherogenic and anti-atherogenic factors with socio-economic status (SES) we performed nutritional survey among 182 (122 men, 60 women) randomly selected individuals using 24 hour diet recall and a food-frequency questionnaire. SES was assessed by educational level which strongly correlated with occupational class (r = 0.55) and income levels (r = 0.88). There was significant (p < 0.05) positive correlation (r values) of educational level with intake of calories (0.55), proteins (0.19), fat (0.45), fat derived energy (en%) (0.14), saturated fat en% (0.45), linoleic acid (0.17), vitamin A (0.14), vitamin C (0.16), vitamin E (0.44), fruits and vegetables (0.34) and fibre (0.24) and negative correlation with intake of linolenic acid (-0.35), monounsaturated fat (MUFA) en% (-0.15), polyunsaturated fat (PUFA)/saturated fat (SFA) (-0.33) and MUFA/SFA (-0.42). In persons of highest educational level (> 15 years education) vs illiterates, the daily intake of SFA (29.1 +/- 15 vs 7.8 +/- 6), SFA en% (13.2 +/- 5 vs 6.7 +/- 4), linoleic acid en% (5.4 +/- 3 vs 3.9 +/- 2) and n6/n3 (24.0 +/- 58 vs 4.5 +/- 5) was more and intake of linolenic acid en% (0.7 +/- 1 vs 1.6 +/- 1), MUFA en% (8.6 +/- 7 vs 15.6 +/- 9), PUFA/SFA (0.6 +/- 1 vs 1.0 +/- 1) and MUFA/SFA (0.7 +/- 1 vs 4.0 +/- 5) was less. Intake of antioxidant vitamins A, C and E and fruits and vegetables was significantly more in better educated.

Adult↗
PubMed1998

Cancer chemotherapy using suicide genes.

Suicide gene therapy is a unique form of drug delivery system that allows for negative selection of malignant cells using a prodrug approach. Malignant cells are transduced with a gene encoding an enzyme that can metabolize an otherwise nontoxic prodrug into a toxic metabolite. The prototype of this system is the herpes simplex virus thymidine kinase gene (HSV-tk). Suicide genes may be introduced into tumor cells either by viral vectors or nonviral methods. Current work is underway to fine tune both the delivery systems and optimize the efficacy of the production of the toxic metabolites. Suicide gene therapy is an exciting strategy currently in clinical trial in the treatment of a number of tumors.

Antineoplastic Agents↗