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Biomedical subjects

D Dubey

Publications and source records attributed to D Dubey.

At least 19 recordsLinked to original sources
PubMed2006

Is laparoscopic approach safe for ectopic pelvic kidneys?

OBJECTIVE: To assess the feasibility and safety of a laparoscopic approach to pelvic kidneys for ablative and reconstructive surgery. METHODS: Between January 2002 and February 2005, 6 patients with a left pelvic kidney; 2 with ureteropelvic junction obstruction, 2 with nonfunctioning kidney and 2 with pelvic stones were selected. These patients underwent dismembered pyeloplasty, simple nephrectomy and pyelolithotomy by laparoscopic approach. For pyeloplasty, omitting the prior retrograde stent facilitated dissection around the pelvis, which was identified first and then the ureter was traced downwards. Dismembered pyeloplasty was done by continuous sutures using 4-0 vicryl over a double-J stent placed antegradely. During nephrectomy, the ureter was identified over the iliac vessels and divided first. Subsequent dissection was carried out after lifting the kidney to identify ectopic renal vessels. Pyelolithotomy was performed for a large single pelvic stone after placing the ureteric catheter and confirming the stone's position by fluoroscopy. RESULTS: One patient with pyelolithotomy was converted to open surgery while the others were completed laparoscopically. Mean hospital stay was 4.16 (range 3-5) days, blood loss 115 (range 30-300) ml and mean operative time was 170 (range 140-220) min. There were no post-operative complications. After pyeloplasty there was significant improvement in renal function and drainage pattern on diuretic scan at 11 and 12 months. CONCLUSION: The laparoscopic approach provides all the benefits of a minimally invasive procedure to the patients. Due to the different locations of renal vessels, it is safe to approach the ureter first when performing nephrectomy. When performing pyeloplasty, omitting the prior stent placement helps in the identification and dissection of the renal pelvis.

Adult↗
PubMed2005

Enterococcal resistance--an overview.

Nosocomial acquisition of microorganisms resistant to multiple antibiotics represents a threat to patient safety. Here, we review the antimicrobial resistance in Enterococcus, which makes it important nosocomial pathogen. The emergence of enterococci with acquired resistance to vancomycin has been particularly problematic as it often occurs in enterococci that are also highly resistant to ampicillin and aminoglycoside thereby associated with devastating therapeutic consequences. Multiple factors contribute to colonization and infection with vancomycin resistant enterococci ultimately leading to environmental contamination and cross infection. Decreasing the prevalence of these resistant strains by multiple control efforts therefore, is of paramount importance.

Animals↗
PubMed2003

Substitution urethroplasty for anterior urethral strictures: a critical appraisal of various techniques.

OBJECTIVE: To retrospectively compare the outcome of various techniques of substitution urethroplasty. PATIENTS AND METHODS: Between 1989 and 2000, 109 patients (mean age 39.5 years) underwent substitution urethroplasty for recurrent anterior urethral strictures. Between 1989 and 1995 the procedure was by ventral placement of free grafts (bladder mucosa, buccal mucosa, penile skin) or penile skin flaps. From 1995 onwards the flaps and grafts (buccal mucosa) were applied either ventrally or dorsally. Stricture recurrence and the complications associated with each technique were compared. RESULTS: Ventral onlay repairs were associated with a higher incidence of complications than dorsal repairs, e.g. postvoid dribbling (39% vs 23%, P = 0.01), ejaculatory dysfunction (20% vs 5%, P = 0.03) and flap/graft pseudo-diverticulum or out-pouching (26% vs 2.6%, P = 0.01). Superficial penile skin necrosis was significantly more common with the use of penile skin flaps than with free grafts. There was no significant difference in stricture recurrence, erectile dysfunction and residual penile deformity among the various techniques. CONCLUSIONS: Dorsal free graft/flap onlay urethroplasty gives better results than ventrally placed free grafts/flaps. Dorsal onlay buccal mucosal urethroplasty is a versatile procedure and associated with fewer complications than other substitution methods.

Adolescent↗
PubMed2001

Cyclosporin A withdrawal in live related renal transplantation: long-term results.

Cyclosporin A (CsA) withdrawal after 1 yr of stable graft function has been shown to be beneficial in cadaveric renal transplantation. This strategy could be even more suitable for 'immunologically advantaged' grafts as in live related renal transplantation. We report the long-term outcome of patients in a live related transplantation programme undergoing early (between 1989 and 1992) and late (1993 onwards) CsA withdrawal as compared with those on long-term low dose CsA (1993 onwards). Two-hundred and fifty-two patients were divided into three groups based on the following immunosuppressive protocol: group ECyW (n=99), early CsA withdrawal (9 months after transplantation); group LCyW (n=44), late CsA withdrawal (median 16 months, range 13--22 months after transplantation); and group LDCy (n=109), long-term low dose CsA. The median period of follow-up was 66 months after transplantation (range 43--84 months). There was no difference in the actuarial 6-yr patient or graft survival among the three groups. Acute rejection episodes were more frequent in ECyW (54.4%) than in LDCy (31.8%) and LCyW (23.8%) (p=0.001). The risk of developing late (> or =9 months) acute rejection was highest in ECyW 32/99 (32.3%) as compared with LCyW 8/44 (18.4%; p=0.08) and LDCy 8/109 (7.3%; p=0.0001). Of the 32 ECyW patients who developed acute rejection episodes after CsA withdrawal, 13 (40.6%) lost their grafts either due to uncontrolled acute rejection or to chronic rejection. Chronic rejection was higher in ECyW (24%) than in LCyW (11%; p=0.04) and LDCy (17%; p=0.17). Antihypertensive requirement was highest in patients maintained on low dose CsA. Graft function, as measured by serum creatinine levels, was significantly better in LCyW (1.24+/-0.4 mg%) as compared with ECyW (1.49+/-0.5 mg%) and LDCy (1.48+/-0.6 mg%). Early CsA withdrawal after live related renal transplantation is associated with a significant risk of acute rejection and subsequent chronic rejection. Slow withdrawal after 1 yr is safe and more economical than the long-term administration of low dose CsA.

Acute Disease↗
PubMed2001

Dorsal or ventral placement of the preputial/penile skin onlay flap for anterior urethral strictures:does it make a difference?

OBJECTIVE: To report our experience in managing complex anterior urethral strictures with a dorsally/dorsolaterally placed penile/preputial vascularized flap, and to discuss the advantages of this procedure over a traditional ventrally placed flap. PATIENTS AND METHODS: Between 1995 and 1999, 40 patients (mean age 40.5 years) with recurrent strictures of the pendulous and/or bulbar urethra were treated with longitudinal penile/circumpenile flap substitution urethroplasty. Nineteen patients underwent dorsal placement of the flap as an onlay (DO), whereas 21 patients had a ventral onlay (VO). Five patients needed inferior pubectomy to facilitate high proximal placement of the flap. RESULTS: Both groups had statistically similar ages, number of previous interventions, stricture site, length and follow-up. After a median follow-up of 27.5 months, the stricture recurred in three (24%) of the VO and two (11%) of the DO groups (P > 0.05). One patient in the VO group required surgical closure of the urethral fistula. Flap pseudo-diverticulum and/or sacculation with postvoid dribble occurred in six patients in the VO and none in the DO group (P = 0.01). CONCLUSIONS: Dorsal placement of the pedicled flap is anatomically and functionally more appropriate than the traditional VO placement. DO preputial/penile flap urethroplasty is a versatile procedure and can be applied even for long anterior urethral strictures, including reconstruction of the meatus and high proximal bulbar strictures.

Adult↗
PubMed2001

Acute urinary retention: defining the need and timing for pressure-flow studies.

OBJECTIVE: To investigate the utility of "late" pressure-flow studies in predicting the outcome of prostatectomy for acute urinary retention. PATIENTS AND METHODS: Fifty-eight patients with acute urinary retention were prospectively assessed using the International Prostate Symptom Score and pressure-flow studies at a median (range) of 24 (13-60) days after the episode of retention, and before transurethral resection of the prostate. Bladder outlet obstruction and bladder contractility were graded using a modified adaptation of Schäfer's passive urethral linear resistance relation. RESULTS: Fifty-six (97%) patients generated a voluntary detrusor contraction, with a mean (range) detrusor pressure at maximum flow of 72.7 (5-144) cmH2O, and 43 (75%) patients were deemed to be obstructed. Eight (16%) patients failed to void after prostatectomy and required clean intermittent catheterization. There were statistically significant differences between successful and unsuccessful patients in mean (SD) age, at 66.30 (6.9) vs 78.8 (2.6) years (P = 0.001), detrusor instability (49% vs 0%, P = 0.01), inability to void during pressure study (8% vs 75%, P = 0.001), and maximal detrusor pressure in the voiding phase, at 80 (36.0) vs 19 (11.2) cmH2O (P = 0.001). CONCLUSIONS: In patients with acute urinary retention, pressure-flow studies undertaken after a period of adequate bladder rest (> 3 weeks) are useful in predicting the surgical outcome. Old age, absence of bladder instability, inability to void during the pressure-flow study and a maximal detrusor pressure of < 20 cmH2O are associated with a poor outcome after prostatectomy.

Acute Disease↗
PubMed2001

Modified bulbar urethral sling procedure for the treatment of male sphincteric incontinence.

BACKGROUND AND PURPOSE: Urinary incontinence secondary to intrinsic sphincter deficiency is a debilitating condition for the patient and an ordeal for the urologist. Because of the complexity of reconstructive surgical techniques and the prohibitive cost of the prosthetic devices used, there is a need for a simple procedure. We herein report our experience in managing urinary incontinence secondary to sphincteric incompetence in nine consecutive patients using a modified bulbar urethral sling procedure over a period of 2 years. PATIENTS AND METHODS: In eight patients, the incontinence followed open prostatectomy or transurethral resection for benign prostatic hyperplasia, and one patient had incontinence following fulguration of posterior urethral valves. Our procedure uses bolsters that are suspended from the rectus fascia, and a hammock made of a folded Dacron patch is placed beneath the bulbospongiosus muscle to form a sling. RESULTS: All patients were continent postoperatively, with only mild stress leakage in the erect posture, during a mean follow-up of 12.2 months (range 6-22 months) and required one or two improvised pads per day to remain continent during the daytime. Persistent perineal infection necessitated removal of the sling in one patient. One patient required clean intermittent catheterization for a short period postoperatively. CONCLUSION: This modified bulbar urethral sling procedure is a simple yet effective method to treat sphincteric deficiency of any cause.

Adult↗
PubMed2001

Dorsal placement of the pedicled preputial/penile onlay flap for anterior urethral stricture: is it more logical?

OBJECTIVES: We present our preliminary experience in the management of inflammatory anterior urethral strictures with a dorsally/dorsolaterally placed penile/preputial vascularized flap and discuss the distinct advantages of this procedure over a traditional ventrally placed flap. METHODS: Twelve patients (age, 20-66 years; mean age, 40.5 years) with recurrent inflammatory strictures of the penile and/or bulbar urethra (penile, 2; bulbar, 5 and bulbopenile, 5) were treated with dorsally/dorsolaterally placed penile/preputial (penile skin, 5; prepuce, 7) vascularized flap substitution urethroplasty. Prior to surgery, 7 patients had suprapubic cystostomy for acute urinary retention and 5 had a mean peak flow rate of 6.2 ml/sec. Inferior pubectomy was performed as an adjunct in two patients to facilitate proximal placement of the flap. Follow-up (5 to 24 months; mean, 15.5) included uroflowmetry and retrograde urethrograms at 6, 12 and 18 months, and thereafter as required. RESULTS: The mean stricture length was 5.8 cm (range, 3 to 12 cm) and all strictures were associated with dense spongifibrosis. Temporary urethral fistulae, which healed spontaneously, occurred in 4 patients. The clinical and radiological outcome during the mean follow up of 15.5 months was gratifying. The mean peak flow rate improved to 24.2 ml/sec. No stricture recurrence has been noted to date. Sacculation of the flap, diverticulum formation and post-void dribble have not been encountered. None of the patients developed chordee or erectile dysfunction. CONCLUSIONS: Dorsal onlay preputial/penile flap urethroplasty is a versatile procedure in the treatment of inflammatory anterior urethral strictures. The dorsal pedicle flap may be anatomically and functionally more logical as compared to the traditional ventrally placed flap.

Adult↗
PubMed1997

Cell-mediated cytotoxicity: a predictor of chronic rejection in pediatric HLA haploidentical renal transplants.

BACKGROUND: Recipient antidonor cytotoxic T-cell activity has been associated with graft loss and acute rejection in renal allograft recipients. The role of immunologic mechanisms in the development of chronic graft rejection is controversial. We analyzed all living related renal transplants performed at Children's Hospital (Boston, MA) from 1983 to 1995 to assess whether cell-mediated cytotoxicity, determined in vitro and measured before transplantation, was predictive of chronic rejection. METHODS: Eighty-three patients were studied retrospectively. Fifty-seven patients with one haplotype-matched renal transplants from living related donors were studied to determine the association between cell-mediated lympholysis (CML) level, acute rejection, chronic rejection, and graft failure. Acute rejection was defined by the decision to treat. Chronic rejection was defined by histology and/or the absolute serum creatinine value using an increasing serum creatinine level >1.0 mg/dl for children less than 3, a creatinine level >1.5 mg/dl for children between 3 and 10 years of age, and a creatinine level >2.0 mg/dl for children above 10 years of age. Return to dialysis or retransplantation was considered graft failure. RESULTS: Of the 57 haploidentical patients, there were 33 males and 24 females. The mean age at transplant was 11.1 years (SD=6.7). Twelve patients developed chronic rejection, 24 patients developed acute rejection, and 7 patients had graft failure. Pretransplant cytotoxic T lymphocyte activity was associated with chronic rejection (P=0.001) and graft failure (P=0.013) but only marginally with acute rejection (P=0.058). Controlling for age and sex, Cox's proportional hazards model revealed that CML level was predictive of time to chronic rejection (P<0.01) but not acute rejection (P=0.11). It was estimated that every 1-unit increase in CML level raises the monthly risk of chronic rejection by 7%. Ten children received HLA-identical kidneys from their siblings. There were no episodes of chronic rejection after 5 years. Two patients with high CML levels had episodes of acute rejection; both patients responded to treatment. CONCLUSION: Our data demonstrate an association between pretransplant cell-mediated cytotoxicity and the occurrence of chronic rejection in living related one-haploidentical renal transplants in pediatric patients.

Adolescent↗
PubMed1993

Anti-interleukin-2 receptor monoclonal antibody therapy supports a role for Th1-like cells in HgCl2-induced autoimmunity in rats.

Brown-Norway (BN) rats injected with HgCl2 develop an autoimmune disease characterized by a T-dependent polyclonal B-cell activation. Increase in major histocompatibility complex class II molecule expression on B cells concomitant with enhancement of serum IgE concentration supports the involvement of the T helper 2 (Th2)-like subset in the induction of the disease. The mercury disease is autoregulated and does not develop in Lewis (LEW) rats. Considering the reciprocal regulation, well defined in mice, between the Th1 and Th2 subsets, we addressed the role of the Th1-like subset in this disease. Brown-Norway and LEW rats injected with HgCl2 were treated with NDS61, a mouse anti-rat-IL-2R MoAb that blocks mainly Th1 cells. Data reported herein show that: (1) HgCl2 treatment does not modify either the percentage of IL-2R+ cells or IL-2R expression in both BN and LEW rats; (2) treatment of BN rats with NDS61 MoAb does not modify the induction phase of the mercury disease but delays in part the regulation phase; (3) such a treatment leads to some immune abnormalities in LEW rats; (4) HgCl2 markedly potentiates the anti-mouse Ig antibody response in BN rats which probably limits the effect of this treatment. This study supports a role for the Th1-like subset in HgCl2-induced autoimmunity in the rat.

Animals↗
PubMed1993

Patients and communities.

In 1992, Chicago's Mount Sinai Hospital Medical Center was awarded the Foster G. McGaw Prize for outstanding community service. This article describes Mount Sinai's commitment and some of the programs that led to its receiving the prize, which is funded by The Baxter Foundation and administered by The Hospital Research and Educational Trust of the American Hospital Association.

Chicago↗
PubMed1983

Cellular basis of defective cell-mediated lympholysis in atopic dermatitis.

Peripheral blood lymphocytes (PBL) from patients with atopic dermatitis (A.D.) were examined for their capacity to generate cytotoxic T lymphocytes (CTL) during mixed lymphocyte cultures (MLC). Cell-mediated lympholysis (CML) activity, but not proliferative response during MLC, was significantly decreased (p less than 0.01) in patients with A.D. (n = 19) compared with normal controls (n = 19) or patients with other skin diseases (n = 14). Regression analysis revealed a significant correlation (p less than 0.001) between CML activity and the percentage of circulating T8+ suppressor/cytotoxic T cells. Deficient CML activity in A.D. patients, however, was not corrected when isolated autologous T4+ and T8+ cells were recombined at a normal ratio (2:1) of T4+ to T8+ cells. Examination of CML activity in co-cultures of isolated T4+ and T8+ cells obtained from two A.D. patients and their respective HLA-identical healthy siblings indicated that the defect in CML resided in both the helper/inducer T4+ cells and the effector T8+ cells. The defective cytotoxic T cell function reported in the present study may account for the increased susceptibility of patients with A.D. to develop severe viral infections.

Adolescent↗
PubMed1980

Use of monocytes in HLA-A, B, C and DR typings.

A simple method of improved serologic typing of monocytes for HLA-A, B, C and DR specificities is described. The method employs monocytes recovered from frozen samples of peripheral blood mononuclear cells; it chiefly involves pretreatment of monocytes with 0.01% iodoacetamide (IAA) prior to typing. The advantage of this method lies principally in the lowering of the background nonspecific cytotoxicities and false positive readings upon IAA addition to the monocyte preparations. Using this method monocytes can be typed for HLA-A, B, C determinants. Although the addition of IAA results in substantial typing improvements, we found the assignment of A, B, C specificities difficult due to the presence of extra positive reactions when monocytes were compared to T lymphocyte typings. probably due to the presence of DR or monocyte specific antibodies in the routinely used HLA antisera. This method proved to be most useful in DR typings where mono cytes in the presence of IAA were compared with autologous B cells in the absence of IAA. The differences in typings due to a decrease in false positive cytotoxic readings were significantly in favor of using IAA treated monocytes in DR typings (P < 0.0001). The use of IAA in the course of B cell or T cell typings bad no adverse consequences on either A, B, C or DR typings, respectively. Our results indicate a potential usefulness for the use of IAA in typing monocytes HLA determinants in general and for the DR determinants in particular.

Enzyme Inhibitors↗
PubMed1980

Platelet HLA typing and cross-matching by a direct microcytotoxic assay. A new method employing carboxyfluoresceindiacetate-stained platelets.

Carboxyfluoresceindiacetate-labelled platelets can be used in direct microcytotoxic assays for the purpose of typing platelets for a number of antigenic determinants, such as HLA and beta-2 microglobulin. The assay when used in direct platelet cross-matching, where thrombocytopenic patient sera were screened, resulted in the uncovering of many extrapositive and weakly positive cross-matches not identified by the lymphocyte cross-match. The simplicity and rapidity of this new method makes it an attractive alternative for future use in research and clinical studies.

ABO Blood-Group System↗