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Biomedical subjects

A K Mandal

Publications and source records attributed to A K Mandal.

At least 19 recordsLinked to original sources
PubMed2003

Trabeculectomy with or without mitomycin-C for paediatric glaucoma in aphakia and pseudophakia following congenital cataract surgery.

PURPOSE: To evaluate the safety and efficacy of trabeculectomy with or without mitomycin-C (MMC) in the management of glaucoma in aphakia and pseudophakia following congenital cataract surgery. PATIENTS AND METHODS: All patients of glaucoma with aphakia or pseudophakia who underwent trabeculectomy with or without MMC from January 1989 to April 2000 were included. The medical records of 19 consecutive patients (23 eyes) were reviewed. Data collected from a retrospective chart review were analysed. Outcome measures were evaluated using Kaplan-Meier survival analysis. Pre- and postoperative intraocular pressures (IOPs), visual acuities, success rate, bleb characteristics, surgical failure and complications were the main outcome measures. Successful IOP control was defined as an IOP between 6 and 21 mmHg, without antiglaucoma medications, without further antiglaucoma surgery and without any sight-threatening complication. RESULTS: The mean age of patients was 8.8+/-5.5 years at the time of trabeculectomy with MMC compared to 11.0+/-12.4 years for trabeculectomy without MMC. Eight patients underwent trabeculectomy with MMC and 11 patients underwent trabeculectomy without MMC. There was no statistically significant difference between the two groups in terms of visual acuity, IOP, antiglaucoma medications, age at cataract surgery and at trabeculectomy. The IOP reduced from a preoperative level of 34.2+/-8.9 mmHg (range: 20-52) to a postoperative level of 18.4+/-12.2 mmHg (range: 2-60) with a mean follow-up of 24.2+/-17.9 months. The mean reduction in IOP in the MMC group was 15.5+/-17.3 and 16.3+/-13.8 mmHg in the other group (P = 0.967). Overall, complete success was achieved in 36.8%, qualified success in 21.1% and surgical failure in 42.1% of patients with a mean follow-up of 24.2+/-17.9 months. There was no difference in the success between the two groups at the last follow-up. One patient developed bleb-related endophthalmitis in both eyes following trabeculectomy with MMC. CONCLUSIONS: The success rate of trabeculectomy in glaucoma following congenital cataract surgery was 36.8% at the end of 3 years. The present study proves a poor success rate of trabeculectomy in a small series of aphakic Asian Indian patients even with the use of MMC.

Adolescent↗
PubMed2002

Computerized tomography attenuation value of renal calculus: can it predict successful fragmentation of the calculus by extracorporeal shock wave lithotripsy? A preliminary study.

PURPOSE: We evaluated the attenuation value of renal calculi on unenhanced axial computerized tomography (CT) images as a predictor of calculous fragmentation by extracorporeal shockwave lithotripsy (ESWL) (Dornier Medical Systems, Inc., Marietta, Georgia). MATERIALS AND METHODS: We included 30 patients with renal calculi up to 20 mm. in this prospective study. Calculous attenuation value was measured in Hounsfield units on unenhanced CT sections through the calculi. Patients were subsequently treated with ESWL. RESULTS: Patients were grouped according to calculous attenuation value as groups 1-less than 500, 2-500 to 1,000 and 3-greater than 1,000 Hounsfield units. Of the 30 patients 24 (80%) underwent successful treatment. The rate of stone clearance was 100% (12 of 12 cases) in group 1, 85.7% (6 of 7) in group 2 and 54.5% (6 of 11) in group 3. The success rate for stones with an attenuation value of greater than 1,000 Hounsfield units was significantly lower than that for stones with a value of less than 1,000 Hounsfield units (6 of 11 versus 18 of 19 cases, chi-square 7.07, p <0.01). Patients in group 3 required a greater median number of shock waves for stone fragmentation than those in groups 1 and 2 (7,300, 2,500, and 3,390, respectively). The mean attenuation value and number of shock waves required for calculous fragmentation correlated significantly (r = 0.779, p <0.001). CONCLUSIONS: The CT attenuation value of renal calculi can help to differentiate stones that are likely to fragment easily on ESWL from those that would require a greater number of shock waves for fragmentation or may fail to fragment on ESWL.

Adult↗
PubMed2001

Herpes simplex virus bullous keratitis misdiagnosed as a case of pseudophakic bullous keratopathy with secondary glaucoma: an unusual presentation.

PURPOSE: To report an unusual case of herpetic bullous keratitis misdiagnosed as a case of pseudophakic bullous keratopathy with secondary glaucoma. RESULTS: A retrospective analysis of the case record of a 60-year-old man who had earlier undergone bilateral cataract surgery, was done. He presented with a complaint of decrease in vision in the right eye of 20 days duration. On examination, cornea showed epithelial bullae all over the surface with stromal and epithelial edema. Intraocular pressure was 30 mm of Hg in RE. He was treated with anti-glaucoma medications. Two dendritic lesions were seen in the cornea during a subsequent visit four days later. Virological investigations confirmed a diagnosis of Herpes simplex keratitis. He was treated with topical acyclovir. CONCLUSIONS: This case highlights the fact that herpes simplex keratitis can present initially as a more diffuse corneal stromal and epithelial edema with epithelial bullae mimicking bullous keratopathy. Herpetic bullous keratitis, although unusual, should be considered in the differential diagnosis under such circumstances.

Acyclovir↗
PubMed2001

Should the indications for laparascopic live donor nephrectomy of the right kidney be the same as for the open procedure? Anomalous left renal vasculature is not a contraindiction to laparoscopic left donor nephrectomy.

BACKGROUND: The left kidney is preferred for live donation. In open live donor nephrectomy, the right kidney is selected if the left kidney has multiple renal arteries or anomalous venous drainage. With laparoscopic live donor nephrectomy (LLDN), there is reluctance to procure the right kidney because of the more difficult exposure and further shortening of the right renal vein (RRV) after a stapled transection. An experience with LLDN is reviewed to determine whether the right kidney should be procured laparoscopically. METHODS: From February 1995 to November 1999, 227 patients underwent live donor renal transplants with allografts procured by LLDN. The results of these transplants were analyzed. RESULTS: Of the 227 kidneys transplanted, 17 (7.5%) were right kidneys. In the early experience, three (37.5%) of the eight right renal allografts developed venous thrombosis, two of which had duplicated RRV. Based on these initially unacceptable results, donor evaluation and LLDN techniques were modified. Spiral computerized tomography (CT) replaced conventional angiography to define better the venous anatomy. LLDN was modified in one of three ways: (1) changing the stapler port placement such that the RRV was transected in a plane parallel to the inferior vena cava, (2) relocation of the incision for open division of RRV, or (3) lengthening of the donor RRV with a panel graft constructed of recipient greater saphenous vein. Finally, the recipient operation enjoined complete mobilization of the left iliac vein with transposition lateral to the iliac artery. With these modifications, there were no vascular complications with the subsequent nine right renal allografts (P<0.05). Of the left kidneys transplanted, 31 had multiple renal arteries, 14 had retroaortic or circumaortic veins, 4 had both multiple arteries and venous anomalies, and 1 had a duplicated IVC draining the left renal vein. There were no vascular complications with left renal allografts that had multiple arteries or venous anomalies. CONCLUSIONS: LLDN of the left kidney is technically easier. Left kidneys with multiple arteries or anomalous venous drainage are not problematic. The right kidney can be procured with LLDN; however, a rational approach to preoperative angiographic imaging, donor operation, and recipient operation is crucial.

Blood Vessels↗
PubMed2001

Penetrating chest wounds: 24 years experience.

Thoracic and thoracoabdominal penetrating wounds are frequently encountered in urban medical centers in the United States. This study was undertaken to determine the clinical characteristics and in hospital outcome of these injuries. This was a longitudinal, nonblinded study using the established standard of care of patients with penetrating chest trauma. It consists of an analysis of a consecutive series of 3049 patients treated at one trauma center between April 1972 and March 1996. There were 1347 stab wounds and 1702 gunshot wounds. Antibiotic prophylaxis was administered to patients who underwent laparotomy or thoracotomy or who had lung contusion with hemoptysis (41.6%, 1296/3049). Of 3049 patients, 196 had cardiac injuries. All of them underwent thoracotomy, and the mortality was 21.9%. In contrast, among 2853 patients without cardiac injuries, only 257 (9%) required thoracotomy; the mortality in this group was 1.5%. Patients with thoracoabdominal injuries (899/3049) had a mortality of 4.3% compared to 2.1% among those who had isolated chest injuries. The overall mortality was 2.8%. Of 1702 patients with gunshot wounds, 85 (5%) sustained transaxial injuries, with an overall mortality of 36.5%. The complication rate among the survivors was 6% with only 2.5% being infectious. We conclude that the mortality for noncardiac penetrating injuries of the chest is low. The presence of associated abdominal injuries increases the mortality twofold. More than one-third of the patients with transaxial wounds die. Gunshot wounds of the heart result in higher mortality than stab wounds to the heart. The infection rate is low.

Abdominal Injuries↗
PubMed2001

Purification, characterization and partial amino acid sequencing of a 70 kD inhibitor protein of Na+,K+-ATPase from goat testis cytosol.

A protein isolated from goat testis cytosol is found to inhibit Na+,K+-ATPase from rat brain microsomes. The inhibitor has been purified by ammonium sulphate precipitation followed by hydroxyapatite column chromatography. The purified fraction appears as a single polypeptide band on 10% SDS-PAGE of approximate molecular mass of 70 kDa. The concentration at which 50% inhibition (I50) occurs is in the nanomolar range. The inhibitor seems to bind Na+,K+-ATPase reversibly at ATP binding site in a competitive manner with ATP, but away from ouabain binding site. It does not affect p-nitrophenyl-phosphatase activity. The inhibitor is found to inhibit the phosphorylation step of the Na+,K+-ATPase. The enhancement of tryptophan fluorescence and changes in CD pattern suggest conformational changes of Na+,K+-ATPase on binding to the inhibitor. Amino acid sequence of the trypsinised fragments show some homology with aldehyde reductase.

Amino Acids↗
PubMed2001

Disrupted signaling and inhibited regeneration in obese mice with fatty livers: implications for nonalcoholic fatty liver disease pathophysiology.

The impaired regenerative capacity of fatty livers might promote the progression of nonalcoholic fatty liver disease (NAFLD). To identify mechanisms involved, regenerative responses were compared in normal mice and ob/ob mice (a model for NAFLD) after partial hepatectomy (PH). We hypothesized that the usual PH activation of oxidant-sensitive, growth-regulatory kinase cascades would be abnormal in fatty hepatocytes, which have adapted to chronic oxidant stress, and expected that this might interfere with the induction of proliferative- and stress-related genes. The normal coordinated induction of Jun N-terminal kinases (Jnks) and extracellular regulated kinases (Erks) does not occur after PH in ob/ob mice, which cannot activate Jnks but can superinduce Erks. Jnk inhibition is associated with enhanced activation of Akt, which inhibits phosphoenolpyruvate carboxykinase (PEPCK) induction, causing severe hypoglycemia and increased lethality in the ob/ob group. Activation of nuclear factor kappaB (NF-kappaB) is also inhibited, but liver damage is increased only modestly, perhaps because Akt-regulated survival factors are protective. Despite enhanced Erk activity, induction of cyclin D-1, an NF-kappaB target gene, is abolished and this, together with hyperphosphorylated signal transducer and activator of transcription-3 (Stat-3) and reduced adenosine triphosphate (ATP) levels, arrests fatty hepatocytes in G(1). Thus, in mice with NAFLD that have adapted hepatocyte signaling mechanisms to survive chronic oxidative stress, the cellular response to an acute regenerative stimulus is altered. This contributes to NAFLD pathophysiology by inhibiting proliferation, increasing injury, and limiting function in fatty livers.

Adenosine Triphosphate↗
PubMed2001

Molecular characterization of murine pancreatic phospholipase A(2).

The pancreatic secretory phospholipase A(2) (sPLA(2)IB) is considered to be a digestive enzyme, although it has several important receptor-mediated functions. In this study, using the newly isolated murine sPLA(2)IB cDNA clone as a probe, we demonstrate that in addition to the pancreas, the sPLA(2)IB mRNA was expressed in extrapancreatic organs such as the liver, spleen, duodenum, colon, and lungs. We also demonstrate that sPLA(2)IB mRNA expression was detectable from the 17(th) day of gestation in the developing mouse fetus, coinciding with the time of completion of differentiation of the pancreas. Furthermore, the mRNA expression pattern of sPLA(2)IB was distinct from those of sPLA(2)IIA and cPLA(2) in various tissues examined. The murine sPLA(2)IB gene structure is well conserved, consistent with findings in other mammalian species, and this gene mapped to the region of mouse chromosome 5F1-G1.1. Taken together, our results suggest that sPLA(2)IB plays important roles both in the pancreas and in extrapancreatic tissues and that in the mouse, its expression is developmentally regulated.

Amino Acid Sequence↗
PubMed2001

Prognostic significance of apoptosis in squamous cell carcinoma of oral cavity with special reference to TNM stage, histological grade and survival.

Apoptotic count was assessed in 38 cases of squamous cell carcinoma of oral cavity by light microscopy and correlated with TNM stage, histological grade and survival. A direct correlation with the TNM stage (p = 0.0166) and an inverse correlation with the histological grade (p = 0.03) was found, however no correlation was found with the survival. Apoptotic count was significantly different between well and moderately differentiated carcinoma (p = 0.347) and well and poorly differentiated carcinoma (p = 0.0190). Thus apoptotic count may have prognostic value particularly in combination with staging and histological grade.

Adult↗
PubMed2001

Management of the late leaking filtration blebs. A report of seven cases and a selective review of the literature.

PURPOSE: To describe the outcome of various treatment modalities in the management of late bleb leaks after glaucoma filtering surgery (GFS). MATERIALS AND METHODS: Seven consecutive patients treated for late bleb leaks (Seidel's positive) between July 1990 and June 1999 were were enrolled in the study. The management strategy consisted of initial conservative therapy, and tailored surgery, if necessary. The surgical technique employed was either conjunctival-Tenon's advancement flap, hinged scleral flap, or fistulectomy with direct suturing. The main outcome measures were bleb characteristics and postoperative intraocular pressure (IOP). The secondary outcome measure was visual acuity. RESULTS: One patient responded to conservative therapy (aqueous suppressants, bandage contact lens) and six patients needed surgery. The successful surgical technique was conjunctivo-Tenon's advancement flap in three, hinged scleral flap in two, and fistulectomy-direct suturing to the wound (combined with cataract surgery and intraocular lens implantation) in one patient. The bleb leak stopped in all cases and 5 of the 6 surgical patients sustained functioning filtering blebs. Follow-up ranged from 8 to 56 months (mean = 20.4 +/- 16.2 months). Visual acuity improved to 6/12 or better in 4 cases, 6/36 in 2 cases and it remained at light perception in one case. None of the patients had any intraoperative or postoperative complications. CONCLUSIONS: Late leaking blebs after GFS can be treated successfully. The management decision and selection of surgical technique should be based on the clinical condition.

Aged↗
PubMed2000

Dynamics of compact denatured states of glutaminyl-tRNA synthetase probed by bis-ANS binding kinetics.

Bis-ANS binds to native glutaminyl-tRNA synthetase (GlnRS) with a fast and a slow phase. The rate constant of the slow phase is independent of bis-ANS concentration suggesting a slow conformational change in the pathway of bis-ANS binding. Aging of GlnRS causes a large decrease of the slow phase amplitude with concomitant increase of the fast phase amplitude. Several other large, multi-domain proteins show similar patterns upon aging. The near UV-CD spectra of the native and the aged GlnRS remain similar. Significant changes in far UV-CD, acrylamide quenching and sulfhydryl reactivity, are seen upon aging, suggesting disruptions in native interactions. Refolding of GlnRS from the urea-denatured state rapidly produces a state that is very similar to the equilibrium molten globule state. Bis-ANS binds to the molten globule state with kinetics similar to that of the aged state and unlike that of the native state. This suggests that the slow binding phase of bis-ANS, seen in native proteins, originate from relatively high energy barriers between the native and the more open states. Thus bis-ANS can be used as a powerful probe for large amplitude, low-frequency motions of proteins.

Amino Acyl-tRNA Synthetases↗
PubMed2000

Plasmapheresis: an effective therapy for primary allograft nonfunction after liver transplantation.

BACKGROUND: The role of plasmapheresis in liver failure and hepatic coma remains controversial. Also, its use as a salvage strategy for patients with severe allograft dysfunction after liver transplantation has not been defined. This report reviews the use of plasmapheresis in primary hepatic allograft nonfunction (PNF). METHODS: From May of 1997 to October of 1998, five patients underwent plasmapheresis for PNF after other causes of immediate allograft dysfunction were excluded. These patients underwent two to five plasmapheresis procedures during which one plasma volume was removed and replaced with fresh frozen plasma (FFP) or with 50% FFP and 50% albumin. RESULTS: All recipients who underwent plasmapheresis had restoration of liver function. There was one death from pulmonary embolism, for an overall survival rate of 80%. The four surviving patients all had functioning allografts 1 year after liver transplantation. In contrast, during the same period, there were two patients in whom PNF was treated by retransplantation, and both died within 3 months after surgery with functioning allografts. CONCLUSIONS: Plasmapheresis provides an effective treatment option for PNF immediately after liver transplantation and may obviate the need for retransplantation.

Adolescent↗