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Biomedical subjects

D K Mitra

Publications and source records attributed to D K Mitra.

At least 73 records · Page 4Linked to original sources
PubMed1998

Fertility and unilateral undescended testis in the rat model II.

Continuing experimental work on the effect of experimentally created unilateral undescended testis (UL-UDT) in neonatal rats, this study examined the fertility and correlated it to contralateral (CL) testicular morphology, seminiferous tubular diameter (STD), DNA flowcytometry, and the presence of serum anti-sperm antibodies (ASA) at 120-135 days of age. In our previous reported work, the fertility of rats with UL-UDT at 65-80 days of age was the same as that of controls. In the present study the rats with UL-UDT had significantly reduced fertility (P < 0.01) compared to controls, even though the Johnsen scores and mean STD of the CL testicular tissue were comparable. DNA flowcytometry demonstrated a significant decrease (P < 0.001) in haploid cell population in the CL testicular tissue of rats with UL-UDT. Furthermore, the rats with UL-UDT who either received an immunosuppressive or in whom the UDT was excised early showed almost normal fertility and DNA histograms like those of controls. Significantly high titres of serum ASA were detected only in the group with UL-UDT when tested at 135 days of age. From these results, in combination with earlier results on similar work, it may be inferred that UL-UDT causes immunologically-mediated, progressive damage to the CL descended testis, leading to a decrease in fertility in rats.

Aging↗
PubMed1998

Upper-tract changes after treatment of posterior urethral valves.

This paper discusses the long-term sequelae in the upper urinary tract with respect to hydroureteronephrosis (HUN), vesicoureteral reflux (VUR), renal parenchymal disease, and their correlation with renal function in 84 boys with posterior urethral valves followed for 1 to 21 years. Thirty-one boys (39.3%) were adolescents or older at the time of review. The incidence of high-grade VUR (grade III or more) was 47.6% at presentation, and resolution following decompression of the lower urinary tract occurred in 38.7% of refluxing units. VUR was associated with a high incidence of chronic renal failure (CRF) (30%) on long-term follow up; however, 16% of non-refluxing patients also progressed to CRF. The incidences of renal parenchymal disease and persistent upper-tract dilatation in the non-refluxing group were 25% and 50% of renal units respectively. Gross HUN persisted in 12.3% of patients despite decompression and reconstructive surgery, with vesicoureteral junction (VUJ) obstruction being documented in 1 patient only. Moderate and mild upper-tract dilatation persisted in 31.6% and 43.9% of patients, respectively. Persistent gross HUN was associated with a very high incidence of CRF (92.3%), while 88.4% of those with persistent mild/moderate dilatation maintained normal renal function over a follow-up period ranging from 1 to 21 years. This study emphasizes the need for systematic evaluation to exclude VUJ obstruction and abnormal urodynamics as a cause of persistent HUN so that effective therapy can be instituted early to relieve back-pressure and to provide a low-pressure reservoir with effective emptying. In the absence of either of these causes, persistent ureterectasis after treatment is presumably due to secondary peristaltic failure as a consequence of ureteral fibrosis, ureteral tortuosity, or developmental dysplasia.

Adolescent↗
PubMed1998

Tubed vaginostomy: a new technique for preliminary drainage of neonatal hydrometrocolpos.

The preferred treatment of neonatal hydrometrocolpos has been vaginal drainage onto the perineum. However, in some situations a temporary vaginostomy is required, for which an indwelling catheter is used. This report describes an operative procedure that avoids the use of any indwelling catheter and at the same time provides excellent drainage and an easy access for performing dye studies to outline the pathological anatomy of the condition. This procedure has been performed in two patients, found ready acceptance, and gave gratifying results.

Drainage↗
PubMed1998

Gastric pneumatosis associated with preduodenal portal vein, duodenal atresia, and asplenia.

An 8-day-old newborn presented with non-bilious vomiting, upper abdominal fullness, and failure to pass meconium. Plain radiographs revealed gastric pneumatosis (GP). At operation, he was found to have a non-obstructive preduodenal portal vein, preampullary duodenal atresia, asplenia, and malrotation. The baby was treated by duodeno-duodenostomy without mobilizing the portal vein and correction of the malrotation according to Ladd's procedure. He made an uneventful recovery and the GP resolved spontaneously. The malformative process was believed to have occurred at or soon after the 5th week of gestation, and the GP probably resulted from intramural air tracking through mucosal tears caused by high intragastric pressure.

Cysts↗
PubMed1998

Somatic growth and renal function after unilateral nephrectomy for Wilms' tumor.

Solitary kidneys in renal donors and patients who have undergone unilateral nephrectomy for malignant disease have been reported to undergo hyperfiltration injury. This study was undertaken to evaluate the somatic growth and development of followed-up patient after Wilms' tumor to evaluate their renal function and identify any evidence of injury in the remaining kidney. The growth and development of all the children was found to be normal, as was DTPA clearance. Microalbuminuria in 24-h urinary collections was detected in 84% of the patients, indicating evidence of hyperfiltration injury. This study highlights the need for close monitoring of the renal function of long-term follow-up patients after Wilms' tumor in addition to the routine monitoring for tumor recurrence.

Albuminuria↗
PubMed1998

The Internet and the paediatric surgeon.

The Internet, which has truly united the world, is an extensive network of inter-linked computers storing immense bytes of information that can be accessed by anyone, transcending all barriers. The paediatric surgery Internet consists of exponentially growing material that deals with information specifically for paediatric surgeons and patients of the paediatric age group. We reviewed the methods available to take advantage of this network to enable busy paediatric surgeons to accrue the benefits easily and efficiently rather than be lost in the information ocean by surfing individually. By getting connected to the Internet, the paediatric surgeon gains enormous information that can be useful for patient care. The Internet has revolutionised scientific publications by virtue of its fast and accurate transmission of manuscripts. Paediatric surgeons can send manuscripts by this channel and also access journals, obviating the inherent lag period of communication by post.

Communication↗
PubMed1998

Multiple urethral calculi in children: report of two cases.

Multiple urethral calculi are rarely found in children. We report herein two unusual cases of children found to have multiple urethral calculi. In one, the calculi formed proximal to a stricture and in the other they formed within a diverticulum. Both patients required urethrotomy for removal of the calculi. A unique cause of urethral stricture is also described in case 1.

Child↗
PubMed1998

Exteriorization of the distal esophagus in the abdomen in esophageal atresia.

METHODS: The distal esophagus was exteriorized on to the left upper abdominal wall (abdominal esophagostomy) in 15 babies who had esophageal atresia with or without tracheo-esophageal fistula. The indications for this procedure were long gap atresia with or without tracheoesophageal fistula in which primary anastomosis was not possible and a major anastomotic dehiscence requiring cervical esophagostomy and gastrostomy. In all these patients a decision to replace the esophagus had been made, and a cervical esophagostomy was constructed. The distal esophagus was mobilized either from the thorax if thoracotomy had been done or by a transhiatal abdominal route. CONCLUSIONS: Advantages of the abdominal esophagostomy include absence of gastroesophageal reflux, no indwelling catheter, early institution of enteral feeds, intermittent catheterization for feeding, easy nursing care, and no stomal complications. In addition, this procedure allows the entire stomach to be available for esophageal replacement and retains the natural gastroesophageal junction and the lower esophagus for anastomosis to any bowel segment being used for the esophageal replacement.

Abdominal Muscles↗
PubMed1998

Urethral strictures after fulguration of posterior urethral valves.

This report discusses the incidence and predisposing factors for postfulguration urethral strictures in 82 boys with posterior urethral valves treated over 20 years and followed up for a period ranging from 1 to 21 years. A urethral stricture developed in three of the 82 patients (3.6%). All newborns and infants with small urethral caliber at presentation were treated on a temporary tubeless diversion, and fulguration of the valves was deferred until 9 to 12 months of age. A 9F resectoscope with a loop electrode was used to fulgurate at 5, 7, and 12 o'clock positions. A definite technical factor leading to a stricture could be identified in one of these three patients. Comparison of the "stricture" group with the "no stricture" group suggested that although dry fulguration did not have a definite correlation with stricture formation, it is best avoided. Refulguration and properly managed preoperative catheterization did not predispose to stricture formation. Meticulous surgical technique and avoiding oversized instrumentation were the most important factors for preventing this complication.

Adolescent↗
PubMed1998

Endoscopic treatment of tracheal diverticulum after primary repair of esophageal atresia and tracheoesophageal fistula.

Two cases of recurrent and persistent respiratory symptoms after primary repair of esophageal atresia and tracheoesophageal fistula are described. The diagnostic workup included barium swallow examination, radionuclide study for gastroesophageal reflux, and bronchoscopy. The tracheal diverticulum was detected on bronchoscopy. Treatment consisted of endoscopic cauterization of the mucosa of the diverticulum and its orifice using electrocoagulation in case 1 and the Nd:YAG laser in case 2. Electrocoagulation produced tracheal edema, which caused severe respiratory distress necessitating temporary tracheostomy. Cauterization with the Nd:YAG laser was safe, effective, and uncomplicated.

Bronchoscopy↗
PubMed1998

Bilateral Wilms tumor: an eleven year experience.

Over the last 11 years, 101 patients of Wilms tumor were treated at our hospital. Of these, 7 had bilateral Wilms tumors (BWT). The first two patients were referred in terminal stages and died. Of the latter five, three have survived while one is on treatment. One patient succumbed to liver metastasis, he had stage III disease on one side and was irregular in his chemotherapy protocol. Remarkably, one of the survivors was cured even after developing vertebral metastasis, retroperitoneal recurrence and bilateral lung metastasis. Part of the success was due to "salvage chemotherapy regimens" using Cis-plantinum, ifosphamide and VP-16. Flow cytometric analysis of DNA ploidy performed on only three of the five patients showed that two tumors were aneuploid and one was diploid. Spectacular cure rates can be achieved in BWT by renal conservation surgeries and effective chemotherapy. The use of "salvage chemotherapeutic regimes" and the study of DNA ploidy is being highlighted.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

HIV does not replicate in naive CD4 T cells stimulated with CD3/CD28.

In this report, we demonstrate that the T cell tropic strain of HIV, LAI, does not replicate in naive CD4 T cells stimulated by cross-linking CD3 and CD28. In contrast, LAI replicates well in memory CD4 T cells stimulated in the same way. Unlike this physiologically relevant stimulation, PHA stimulates productive LAI replication in both naive and memory T cells. These studies were conducted with highly purified (FACS-isolated) subsets of CD4 T cells identified by expression of both CD45RA and CD62L. Remixing of purified T cells showed that naive T cells do not suppress LAI replication in memory T cells and that memory T cells do not restore LAI expression in naive T cells. The suppression of productive LAI replication in naive T cells is not due to differential expression of viral coreceptors, nor is it due to inhibition of activation of the important HIV transcription factors, nuclear factor-kappaB and activator protein-1. The inherent resistance of naive T cells to productive HIV infection, coupled with their proliferative advantage as demonstrated here, provides a sound basis for proposed clinical therapies using ex vivo expansion and reinfusion of CD4 T cells from HIV-infected adults.

Apoptosis↗
PubMed1997

HLA-DR polymorphism modulates the cytokine profile of Mycobacterium leprae HSP-reactive CD4+ T cells.

In the present study, in vitro attempts have been made to define the cytokine profile of CD4+ T cells from polar leprosy patients and healthy individuals against Mycobacterium leprae-derived heat shock proteins (HSPs), HSP65 and HSP18, and their trypsin-digested fragments, relating to HLA-DR polymorphism. While all tryptic fragments of optimal digestion and undigested HSPs could stimulate CD4+ T cells from tuberculoid (TT) leprosy patients and healthy contacts (stimulation index, SI > 2.0), only two fragments, TDB65-2 (18 kDa) and TDB18-3 (3 kDa) triggered CD4+ T cells of anergic lepromatous (LL) leprosy patients. Both of these HSPs and their tryptic fragments showed diverse HLA-DR restriction, with DR15 providing the strongest restriction. Cytokine analysis demonstrated that HSP65 and HSP18 induced Th1-like activity in the context of all the restricting HLA-DR alleles, except DR1 and DR7 which induced a Th2 type of response against HSP65 and HSP18, respectively. These Th2 inducer epitopes on HSP65 (DR1 restricted) and HSP18 (DR7 restricted) were absent from TDB65-2 and TDB18-3 which exclusively triggered Th1 cells in both TT and LL forms of leprosy in the context of multiple DR alleles, DR15 being the major antigen-presenting allele. These studies suggest that the major histocompatibility complex phenotype of the antigen-presenting cell can modulate Th1-like versus Th2-like activity against M. leprae pathogens in leprosy and healthy individuals.

Adjuvants, Immunologic↗
PubMed1997

Mesenteric neurofibroma in von Recklinghausen's disease.

The authors report the case of a 6-year-old boy admitted for surgical removal of a 5- x 4-cm neurofibroma over the left wrist. On routine clinical examination a mobile firm, nodular, central abdominal mass was discovered. At laparotomy a tumor (measuring 7 x 5 x 3 cm) arising from the ileal mesentery was found. Complete excision of the mass together with a segment of ileum, followed by end-to-end bowel anastomosis was performed. Histological examination showed that the main elements of the mass consisted of wavy, long-spindled cells that crossed irregularly (pallisading negative). Special stains and immunocytochemistry for S-100 protein confirmed the mass to be a neurofibroma of the mesentery. The patient had an uneventful postoperative course and no signs of recurrence or fresh tumor have been recognized in the 4 years since his operation.

Anastomosis, Surgical↗
PubMed1997

Genitourinary tuberculosis in pediatric surgical practice.

BACKGROUND: Genitourinary tuberculosis (GUTB) has been reported to account for 20% to 73% of all cases of extrapulmonary tuberculosis in the general population but is much rarer in children. GUTB is a form of secondary tuberculosis with vague symptoms. Surgical intervention is required in a minority of cases. METHODS: Nine cases of genitourinary tuberculosis (GUTB) were diagnosed and treated from 1988 to 1995. The age of the patients ranged from 5 to 12 years. There were five boys and four girls. Presenting features were diverse and included gross hematuria in 44% of cases and epididymoorchitis in 22% of cases. Rarer presenting features included acute renal failure, staghorn calculus, and pyonephrosis. Associated or past history of tuberculosis was present in three patients. Conclusive diagnosis was made on the basis of isolation of mycobacterium tuberculosis, histopathology, or cystoscopy in eight patients, whereas one patient was given a therapeutic trial based on clinical manifestations. RESULTS: Response to antitubercular drug therapy was gratifying. Excisional surgery in the form of nephrectomy was needed in one patient, whereas another underwent bilateral ureteric replacement with ileal loops for multiple ureteric strictures. CONCLUSIONS: The wide variety of presenting features and pathological lesions that result from GUTB are emphasized. The diagnosis of GUTB must be suspected in patients who present with hematuria (gross or otherwise), epididymoorchitis, and patients with long segment or multiple ureteric strictures. In view of the anticipated resurgence in tuberculosis caused by the prevalence of aquired immunodeficiency syndrome the pediatric urologist must be aware of the pathophysiology and clinical spectrum of this disease.

Antitubercular Agents↗
PubMed1996

Congenital diaphragmatic hernia with ipsilateral eventration: a report of two cases.

We report herein the cases of two patients in whom the unusual association of a diaphragmatic hernia with eventration of the diaphragm on the same side were confirmed. Although various recognized patterns of malformations have been described in children with diaphragmatic defects or eventration, to the best of our knowledge, this association has never been reported before. Following our case reports, the literature on this unusual topic is reviewed and a discussion on the possible pathogenesis is presented.

Child↗