Biomedical subjects

N Ahsan

Publications and source records attributed to N Ahsan.

At least 37 records · Page 2Linked to original sources

PubMed1998

Intravenous infusion of total dose iron is superior to oral iron in treatment of anemia in peritoneal dialysis patients: a single center comparative study.

In the treatment of anemia of chronic renal failure, the most common cause of recombinant human erythropoietin (rhEPO) resistance is iron deficiency. In peritoneal dialysis (PD) patients, oral iron therapy is an accepted and convenient method of iron supplementation. The effectiveness of oral iron, however, is limited by many factors, including gastrointestinal side effects and poor gastric absorption. This study prospectively compared the efficacy of single intravenous infusion of total dose iron (ITDI group) given in an outpatient setting with oral iron (oral group) for the treatment of anemia in PD patients. Twenty-five adult stable PD patients with baseline hematocrit 25 to 35% were entered into the study. Thirteen patients with serum transferrin saturation (TSAT) < 25% received ITDI, and 12 patients with TSAT between 25 and 35% received oral iron. One patient in the oral group received emergent blood transfusion and was excluded from analysis. Hematocrit and iron indices were measured at monthly intervals. Doses of rhEPO were adjusted monthly to maintain target hematocrit at 35%. At the end of the study (6 mo), despite similar baseline mean hematocrit (31.0 +/- 0.9 versus 33.0 +/- 1.0%), comparable mean baseline weekly rhEPO dose (7886 +/- 1449 versus 6370 +/- 1553 U/wk), and significantly lower level of mean TSAT (11.3 +/- 3.5 versus 30.1 +/- 3.5%; P < 0.05), the ITDI group when compared with the oral group had significantly higher mean hematocrit (36.0 +/- 1.0 versus 31.4 +/- 1.1%; P < 0.05) and TSAT (33.7 +/- 3.7 versus 22.6 +/- 4.0%; P < 0.05) values. In addition, the final mean dose of weekly rhEPO was significantly lower in the ITDI group (4799 +/- 981 versus 9998 +/- 1027 U/wk; P < 0.05). No patient in the ITDI group developed an adverse reaction to intravenous iron. It is concluded that ITDI represents a more efficacious method of iron supplementation in PD patients receiving rhEPO. Moreover, ITDI is safe and well tolerated and can be administered in an outpatient setting.

Administration, Oral↗

PubMed1998

ITDI is the preferred treatment for iron supplementation in rHuEpo-treated anemic PD patients.

In recombinant human erythropoietin (rHuEpo)-treated anemic peritoneal dialysis (PD) patients, oral iron therapy, despite its limited efficacy, remains an accepted and convenient method of iron supplementation. In this study, we compared infusion of total dose iron (ITDI) to oral iron for the treatment of anemia in PD patients. Thirteen patients with serum transferrin saturation (TSAT) < 25% received ITDI and 11 patients with TSAT between 25% to 35% received oral iron. Doses of rHuEpo were adjusted monthly to maintain target hematocrit at 35%. Both groups had similar baseline mean hematocrits (31.0 +/- 0.9% vs. 33.0 +/- 1.0%), and comparable mean baseline weekly rHuEpo dose (7886 +/- 1449 units/week vs. 6370 +/- 1553 units/week). At the end of the 6-month study, the ITDI group had a 16% improvement in mean hematocrit compared to baseline. The final mean dose of weekly rHuEpo was also reduced by 59% in the ITDI group. During the same period, compared to baseline, the oral group had a 4.8% fall in mean hematocrit despite 51% higher requirement of rHuEpo doses. There was no adverse reaction to intravenous iron. We conclude that ITDI is the preferred treatment for iron supplementation in rHuEpo-treated anemic PD patients.

Administration, Oral↗

PubMed1998

Immunopathogenesis of human immunodeficiency virus.

Human immunodeficiency virus (HIV) types 1 and 2 infect cells of the immune system and initiate a robust immune response which counteracts the viral spread but also accelerates the destruction of the immune system. Many pathogenic mechanisms have been proposed which include viral gene products, syncytium formation, direct virus killing of cells, apoptosis, autoimmunity, cytokine and chemokine expression, superantigens, virus directed cell-mediated cytolysis, and disruption of the lymphoid architecture. At present, there is no unifying theory or experimental proof of a single or a predominant mechanism for the pathogenesis of the HIV disease. This review is intended to highlight areas of HIV research relevant to the understanding of HIV immunopathogenesis.

Acquired Immunodeficiency Syndrome↗

PubMed1997

Recurrent type I membranoproliferative glomerulonephritis after renal transplantation and protective role of cyclosporine in acute crescentic transformation.

Almost all diseases affecting the native kidney may recur in the transplanted kidney, with one of the most frequent being recurrent glomerulonephritis. Among the glomerulonephritides, membranoproliferative glomerulonephritis (MPGN), immunoglobulin A nephropathy (IgA), and focal-segmental glomerulosclerosis (FSGS) have the highest rates of recurrence. Here we report a patient who, after living-related kidney transplantation, suffered allograft loss shortly after surgery due to recurrence of glomerulonephritis. Two weeks prior to transplant nephrectomy light microscopic examination of the allograft biopsy failed to show glomerulonephritis. Subsequent histopathology of the transplant nephrectomy specimen demonstrated a crescentic form of type I MPGN following withdrawal of cyclosporin A (CsA) and intense course or oral steroid therapy. The entity of recurrent type I MPGN in kidney transplantation is reviewed, and a possible protective role of CsA against rapidly progressive crescentic type I MPGN is explored.

Cyclosporine↗

PubMed1997

Successful reversal of acute vascular rejection in a renal allograft with combined mycophenolate mofetil and tacrolimus as primary immunotherapy.

Despite the use of newer immunosuppressive drugs, early allograft rejection is still a major cause of graft loss and diminished graft survival. The pathological picture of acute interstitial rejection usually responds to high dose steroids, whereas the treatment of acute vascular (AVR) rejection characterized by an intense vasculitis and/or endotheliolitis is more formidable. The use of newer monoclonal antibodies specific for T lymphocytes and their subsets has only been occasionally successful in reversing AVR. Here we report a case of successful reversal of acute vascular renal allograft rejection with mycophenolate mofetil (MMF) and tacrolimus as primary therapy.

Adult↗

PubMed1997

Pure red cell aplasia due to parvovirus B19 infection in solid organ transplantation.

Human parvovirus B19 disease is an infrequent but recognized rare cause of anemia in immunocompromised patients. A few cases of parvovirus B19 infections have been reported in transplant recipients, of those only four patients underwent renal transplantation. The primary immunosuppressive therapy in these patients included prednisone with either cyclosporine or tacrolimus. In one patient the disease was self-limiting, while in three others the hematocrit improved following 10-15 d of treatment with commercial intravenous immunoglobulin (IVIG). Herein, we report the fifth case of pure red cell aplasia due to parvovirus B19 infection in a renal transplant recipient who responded to a 5-d course of IVIG. To our knowledge, this is the first case of parvovirus B19 infection in a patient with solid-organ transplantation whose immunosuppressive regimen included both mycophenolate mofetil and tacrolimus and in whom an excellent clinical response was achieved with a short course of IVIG infusion.

Adult↗

PubMed1997

Efficacy of oral ganciclovir in prevention of cytomegalovirus infection in post-kidney transplant patients.

Unlike parenteral gancicovir, the efficacy of oral ganciclovir in the prevention and treatment of cytomegalovirus (CMV) infection in kidney transplantation has not been well documented. This study prospectively evaluated the episodes of CMV infection within the first nine months after transplantation in renal transplant recipients treated prophylactically with oral ganciclovir (750 mg twice a day) over a period of 3 months (oral ganciclovir, N = 22), compared with patients randomly assigned as controls (controls, N = 22) who did not receive any anti-viral prophylaxis. Diagnosis of CMV infection at presentation included serological determination of CMV-specific immunoglobulin M antibodies, CMV immunofluorescence assay [standard culture tube and shell vial] (blood) and virus isolation (urine and tissue). CMV infection occurred in one patient (5%) in the oral ganciclovir group and 6 patients (27%) in the control group (p < 0.05). The episodes of biopsy proven allograft rejections were 5% (1/21) and 18% (4/22) in the oral ganciclovir and control groups, respectively. Except for one, none of these patients developed CMV infection either before or after rejection(s). Controlling for the reason (induction or treatment of rejection) for using cytolytic antibody therapies, we found that prophylactic oral ganciclovir was protective against CMV infection (adjusted risk reduction 0.83; 95% confidence interval, 0.33-0.98; p < 0.05). Neither, the CMV status of donors and recipients nor the treatment for acute rejection had any significant impact on the occurrence of CMV infections. Our results show that oral ganciclovir is an effective and well tolerated therapy in the prevention of CMV infection in renal transplant patients.

Administration, Oral↗

PubMed1996

Adverse effect of donor vasopressor support on immediate and one-year kidney allograft function.

BACKGROUND: This purpose of this study was to determine if there was a significant difference between the rates of acute tubular necrosis (ATN) and long-term graft survival in renal allografts procured from donors requiring inotropic support (DRIS) and those from donors not requiring inotropic support. METHODS: Eighty-two consecutive cadaveric renal transplant patients were prospectively followed in our local procurement area, the Delaware Valley Transplant Program. Forty-eight patients received organs from DRIS (> 10 mcg/kg per minute of dopamine, dobutamine, epinephrine, and norepinephrine alone or in combination), and 34 did not. RESULTS: Allografts from the non-DRIS group had an immediate function rate of 82.4% and a 1-year function rate of 91.2%. In comparison, the DRIS grafts had an immediate function rate of 58.3% and a 1-year function rate of 72.9%. These differences were statistically significant. The mean serum creatinine in the non-DRIS group was 1.46 +/- 0.58 mg/dl, whereas in the DRIS cohort it was 1.89 +/- 0.93 mg/dl. CONCLUSIONS: Kidneys transplanted from DRIS had significantly (1) poorer immediate function, (2) worse 1-year survival rates, and (3) higher serum creatinine at 1 year. We conclude that recipients receiving organs from donors requiring inotropic support are at a higher risk of developing ATN after surgery and experience reduced 1-year function.

Adolescent↗

PubMed1996

Acute renal failure secondary to solid tumor renal metastases: case report and review of the literature.

Renal metastases from solid tumors to both kidneys rarely result in acute renal failure (ARF). We present a case of squamous cell pulmonary carcinoma responsible for ARF due to (1) extensive (50% to 75%) bilateral parenchymal infiltration and replacement accompanied by tissue destruction, (2) widespread vascular invasion and thrombosis resulting in ischemia, and (3) histological evidence for foci of distal intratubular obstruction and pyelonephritis. Five additional cases, including one pulmonary cancer, causing ARF from extensive tissue replacement and destruction are reviewed. In a separate case, ARF resulted from lymphatic metastases rather than from parenchymal destruction or obstruction. Common findings in all six reported cases include bilaterally enlarged kidneys and progressive oligoanuria despite correction of prerenal or postrenal conditions. In our patient and in one other prior reported case, extrarenal obstruction was not considered important because invasive therapeutic procedures were unsuccessful in reversing ARF. In one case, irradiation of kidney tumor resulted in reversal of ARF. These cases emphasize the rare potential for solid tumors to metastasize to both kidneys and result in irreversible oligoanuric ARF. A high level of suspicion is required, and an early diagnosis may result in reversible ARF if the tumor is amenable to chemotherapy or irradiation.

Acute Kidney Injury↗

PubMed1996

Fecal short-chain fatty acids in patients with diarrhea-predominant irritable bowel syndrome: in vitro studies of carbohydrate fermentation.

Colonic bacterial production of short-chain fatty acids (SCFA) plays an important role in the salvage of unabsorbed carbohydrate and in colonic absorption of electrolytes and water. The objective of this study was to determine whether patients with diarrhea-predominant irritable bowel syndrome (DP-IBS) have a different pattern and rate of fermentation of carbohydrate and fiber to SCFA compared with controls. Fecal homogenates from 10 patients with DP-IBS and 10 age-matched controls were studied. SCFA were measured by gas chromatography in baseline fecal samples and in fecal homogenates in an in vitro anaerobic fermentation system after incubation with no additional substrate, lactulose, potato starch, citrus pectin, and hemicellulose over a 24-hour period. Net SCFA production rates were calculated for the first 6 h of the incubation period. Patients with DP-IBS had a consistently different pattern of less total SCFA, a lower percentage of acetate (p < 0.05), and a higher proportion of n-butyrate (p < 0.05) than controls. In stool homogenates from both controls and DP-IBS patients, lactulose fermentation resulted in the highest rate of SCFA production followed by pectin, starch, and hemicellulose. However, at all time points, the fecal homogenates from controls generated a higher concentration of total SCFA, acetate, and propionate with all substrates tested. SCFA production rates were higher in controls incubated with lactulose, starch, and hemicellulose. The fecal SCFA profile of patients with DP-IBS is characterized by lower concentrations of total SCFA, acetate, and propionate and a higher concentration and percentage of n-butyrate. Fecal flora from these patients produced less SCFA in an in vitro fermentation system in response to incubations with various carbohydrates and fibers. Differences in SCFA production by colonic bacterial flora in patients with DP-IBS may be related to the development of gastrointestinal symptoms.

Acetates↗

PubMed1996

Acute renal failure following immunoglobulin therapy.

Intravenous IgG infusion has infrequently been reported to cause acute renal failure. In almost all these reports, a sucrose containing IgG product was believed to be the cause of renal injury. Sucrose-induced osmotic nephrosis has been well described in the literature. In this report, we describe a case of acute anuric renal failure following a large infusion of intravenous IgG containing sucrose. Urine cytology demonstrated typical osmotic injury to the renal tubular epithelial cells. Early recovery of renal function was achieved by dialytic removal of sucrose from the circulation.

Acute Kidney Injury↗

PubMed1996

Effect of use of vasopressors in organ donors on immediate function of renal allografts.

The purpose of this study was to determine whether use of vasopressors in cadaveric donors of renal transplants was associated with an increased prevalence of acute tubular necrosis after kidney transplantation. We compared immediate allograft function in 26 consecutive renal allograft recipients whose donors had been given vasopressors with that in 26 recipients whose donors had nor. The donors treated with vasopressors had been given more than 10 micrograms/kg per minute of dopamine, norepinephrine, or epinephrine, alone or in combination. The groups were matched with respect to donors' age, recipients' disease, and cold ischemic time. The prevalence of immediate allograft function was significantly lower in recipients whose donors had required use of vasopressors (38.5%) than in recipients whose donors had not required vasopressors (65.4%). We conclude that use of vasopressors in kidney donors leads to an increased prevalence of acute tubular necrosis.

Adolescent↗

PubMed1996

Efficacy of bolus intravenous iron dextran treatment in peritoneal dialysis patients receiving recombinant human erythropoietin.

The efficient use of recombinant human erythropoietin (rHuEPO) requires adequate body stores of iron. In peritoneal dialysis (PD) patients, iron replacement is most commonly administered orally. In this study, we prospectively followed 7 stable PD patients following bolus intravenous infusion of 1 g iron dextran in an outpatient setting. At 12 weeks, significant (p < 0.05) increments in mean hematocrit from 29.13% to 34.85%, transferrin saturation from 10.15% to 29.33%, serum iron from 27.38 to 67.00 micrograms/dL, and serum ferritin from 150.30 to 331.40 ng/mL were observed. Post-treatment, there was less requirement of rHuEPO, and at six months there was a 26% reduction in the mean weekly subcutaneous rHuEPO dose. At 12 weeks, serum albumin increased significantly from 3.50 to 3.76 g/dL (p < 0.05). There was no abnormality in any of the measured liver function tests. No patient developed an adverse or allergic reaction. We concluded that bolus intravenous infusion of iron dextran is an effective and well-tolerated method of repleting iron stores, and will allow a more efficient and economic use of rHuEPO in PD patients.

Adult↗

PubMed1996

The Family Preservation and Support Services Program.

Two recent issues of The Future of Children have examined programs that support families with young children: the Winter 1993 issue on home visiting and the Winter 1995 issue on the long-term outcomes of early childhood programs. In both issues, the legislation creating the Family Preservation and Support Services Program was discussed as a possible funding source for such programs. This Revisiting article summarizes the key elements of that federal program and discusses some of the challenges states have faced as they have tried to implement the new law. Thus far, the legislation has had only a modest impact on the availability of services, but it has triggered a comprehensive and broad-based planning process that is likely to have lasting benefits.

Child↗

PubMed1995

Leprosy-associated renal disease: case report and review of the literature.

Leprosy is an infectious disease the principal clinical manifestations of which are anesthetic skin lesions and the development of peripheral neuropathy. The most common renal manifestation in leprosy patients is glomerulonephritis. Both immunofluorescent and electron microscopic studies suggest that the varied glomerular lesions found in these patients are immune complex mediated. Other renal lesions that have been described include amyloidosis, tubulointerstitial disease, acute renal failure, and functional defects in the absence of identifiable histologic abnormalities. In this report, a patient is described who developed the clinical syndrome of rapidly progressive glomerulonephritis. The renal biopsy showed a diffuse endocapillary proliferative process with electron-dense deposits in the glomerular subendothelial and subepithelial spaces. Organisms consistent with Mycobacterium leprae were identified within several of the glomeruli.

Aged↗

PubMed1995

Gastrointestinal tuberculosis in renal transplantation: a case report and review.

The pattern of tuberculosis has changed and in recent years: extrapulmonary tuberculosis has become more common, especially in immuno-compromised individuals. A case of primary intestinal tuberculosis in a patient with kidney transplant is reported. The patient presented with persistent fever and right-sided abdominal pain. Histopathology of colonic tissue showed granulomatous inflammation containing acid fast bacilli, and culture of the tissue grew Mycobacterium tuberculosis. Clinical improvement occurred after institution of appropriate anti-tubercular treatment.

Abdominal Pain↗

PubMed1994

Intravenous immunoglobulin-induced osmotic nephrosis.

Intravenous immunoglobulin preparations are being used for an increasing number of indications in clinical medicine. To minimize adverse reactions, sugar additives such as sucrose are added to some preparations to serve as stabilizing agents. We describe a patient treated with an immunoglobulin preparation containing sucrose who developed a fully reversible form of acute renal failure with histologic changes characterized by vacuolization and swelling of renal proximal tubular cells. We believe the high concentration of sucrose in the immunoglobulin preparation resulted in osmotic injury to the renal tubules. Such changes, which are identical to those described in humans and experimental animals given intravenous infusions of hypertonic sucrose, have come to be known as osmotic nephrosis. Risk factors for the development of this lesion are renal insufficiency and volume depletion. The risk for such injury can be minimized by further diluting the immunoglobulin preparation and slowing the infusion rate.

Aged↗

PubMed1994

Fecal short-chain fatty acids in children with inflammatory bowel disease.

Nutrition of colonic epithelial cells (colonocytes) is maintained by luminal short-chain fatty acids (SCFAs), chiefly by n-butyrate. The importance of SCFAs for the maintenance of colonic epithelium has been demonstrated in animal models of colitis produced by rectal instillation of an inhibitor of SCFA oxidation and in patients with diversion colitis in whom a segment of colonic epithelium was deprived of contact with luminal SCFAs. We measured fecal SCFAs and lactate in children with ulcerative colitis (UC; n = 17) and with Crohn's disease with ileocolonic involvement (CD; n = 22) and age-matched controls (n = 12) by a vacuum-distillation, gas chromatographic method. Fecal SCFA concentrations were correlated with scores of clinical disease activity. Patients with UC and CD had a decrease in the fecal concentration of acetate (p < 0.05) and an increase in n-butyrate (p < 0.01) compared with controls. No significant changes in fecal lactate were seen. A comparison of inactive- or mild-UC patients with moderate or severe-UC patients yielded major differences in SCFA concentrations with n-butyrate increased in inactive and mild UC well above control values and total SCFA and acetate decreased in moderate and severe UC below control levels. Raised concentrations of fecal n-butyrate may reflect impaired utilization of this SCFA in the colon of patients with mild UC and Crohn's disease with colonic involvement. Whether this defect is primary or secondary to inhibitors in the colonic lumen, due to impaired transport of n-butyrate into the cell or defective metabolism within the cell, or specific to inflammatory bowel disease remains to be explored.

Adolescent↗