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Biomedical subjects

I Bhan

Publications and source records attributed to I Bhan.

At least 19 recordsLinked to original sources
PubMed2000

Nitric oxide (NO.) stabilizes whereas nitrosonium (NO+) enhances filopodial outgrowth by rat retinal ganglion cells in vitro.

Recent observations suggest that nitric oxide (NO(.)) can increase or decrease growth cone motility. Here, these apparently paradoxical results are explained by distinct actions of different NO-related species. Filopodial morphology of 223 rat retinal ganglion cells was monitored under computer-enhanced video microscopy in the presence of NO synthase (NOS) substrates or inhibitors, donors of specific NO-related species, and membrane-permeant cyclic nucleotide analogs. Physiological NOS activity induced filopodial outgrowth, whereas inhibition of NOS stabilized filopodia. Similar to NOS, nitrosonium (NO(+) transfer) and peroxynitrite (ONOO(-)), which can regulate the activity of growth-associated proteins by S-nitrosylation and oxidation, respectively, induced filopodial outgrowth. In contrast, NO(.), which stimulates guanylate cyclase to increase cGMP, stabilized filopodial activity. Thus disparate NO-related species may offer a dynamic process of filopodial growth regulation.

Animals↗
PubMed2000

Association of bronchopulmonary sequestration with expression of the homeobox protein Hoxb-5.

Bronchopulmonary sequestration (BPS) is caused by the abnormal development of an accessory lung diverticulum from the foregut very early in embryogenesis. The developmental abnormalities seen with BPS suggest that this anomaly is caused by abnormal expression of homeobox genes, which control axial identity and organ-specific patterning during embryogenesis. The authors previously have shown that the homeobox gene Hoxb-5 is necessary for normal airway branching during lung development. The authors now report that BPS is associated with aberrant developmental expression of Hoxb-5 protein, suggesting that this Hox gene is involved in the development of BPS.

Bronchopulmonary Sequestration↗
PubMed1996

Possible new autosomal recessive syndrome of lymphedema, hydroceles, atrial septal defect, and characteristic facial changes.

We describe two brothers with congenital lymphedema of lower limbs, atrial septal defect (ASD), and similar facial appearance. A sister had severe hydrops fetalis, ASD, omphalocele, and other anomalies. This combination of congenital lymphedema and ASD differs from other reported cases of congenital lymphedema and most likely constitutes a previously unrecognized autosomal recessive syndrome.

Abnormalities, Multiple↗
PubMed1996

Desmoplastic small cell tumor: a report of three cases and a review of the literature.

PURPOSE: Desmoplastic round cell tumor (DSCT) is a highly malignant abdominal tumor first described in 1991, with subsequent cases predominantly noted in pathologic case reports. The authors evaluated response to alternating, intensive chemotherapy in three patients with DSCT, and reviewed the clinical experience with this newly described tumor as reported in the literature. PATIENTS AND METHODS: Three adolescent boys with DSCT were treated intravenously with vincristine 2 mg/m2, doxorubicin 75 mg/m2, cyclophosphamide 1.8 g/m2, alternating with 5-day cycles of etoposide 100 mg/m2/day, ifosfamide 1.8 g/m2/day for a total of 11-15 courses. RESULTS: Each patient showed initial tumor regression during chemotherapy, but developed progressive disease within 8-18 months. One patient subsequently showed a transient response to doxorubicin 45 mg/m2 plus 5-fluorouracil 500-600 mg/m2. All three patients died of disease within 20 months of diagnosis. A comprehensive literature review of clinical data on 101 reported cases of DSCT is presented. The median age was 21 years (range 6-38 years) with 78 male patients and 23 female patients. Ninety-nine cases involved tumor mass in the abdominal-pelvic cavity in proximity to the mesentery. Metastatic seeding to the omentum was most common, followed by spread of disease to liver, distant lymph nodes, lung, and occasionally to scrotum or to ovary. Tumor response to chemotherapy was noted in approximately 50% of 40 patients who received combinations of doxorubicin, cisplatin, cyclophosphamide, etoposide, and/or 5-fluorouracil. Four of 13 patients who received additional radiotherapy were alive at 24-48 months. Median survival was 17 months (range: 3-72 months), with only two patients reported disease free beyond 2 years at 40 and 48 months. CONCLUSION: DSCT should be included in the differential diagnosis of small round cell tumors in children and young adults. Tumor regression has been noted during multiagent chemotherapy, but prolonged survival is rare with current therapies.

Abdominal Neoplasms↗
PubMed1991

IgA nephropathy as a possible cause of renal insufficiency following liver transplantation.

Three years following successful liver transplantation, a child developed proteinuria, hematuria and hypertension in the setting of progressive renal insufficiency. These abnormalities did not resolve with lower doses of ciclosporin. Because multiple drugs were required to control the hypertension and because no other etiology of the urinary abnormalities could be found, a renal biopsy was performed. The renal biopsy revealed findings consistent with severe IgA nephropathy, including glomerulosclerosis, segmental crescents, mesangial cell and matrix expansion, mesangial deposits, and positive immunofluorescence for IgA.

Biliary Atresia↗
PubMed1988

Polyneuropathies associated with IgM monoclonal gammopathies.

We studied ten patients with IgM monoclonal gammopathies. Five had M proteins that reacted with myelin-associated glycoprotein (MAG) and five had no recognizable antinerve activity. The neuropathy in the MAG-reactive patients was homogeneous by clinical and laboratory analysis, while the neuropathy in the MAG-nonreactive patients varied considerably. Both groups responded well to immunosuppressive therapy, which lowered the concentration of the serum M protein. The homogeneity of the MAG-reactive patients and their response to sustained lowering of the M protein levels support the concept that the IgM M protein directly damages nerve fibers and is the proximate cause of the polyneuropathy.

Aged↗
PubMed1988

Atypical lymphohistiocytic infiltrate (pseudolymphoma) of the oral cavity.

In the oral cavity, differentiation between reactive and neoplastic lymphoproliferative lesions can, at times, be very difficult. We report an unusual case in which immunohistochemical findings were necessary to determine that the lesion was reactive despite the original interpretation of malignant lymphoma. The relationship of this lesion to atypical histiocytic granuloma, angiolymphoid hyperplasia with eosinophilia, and traumatic ulcerative granuloma with stromal eosinophilia is discussed and possible pathogenetic mechanisms are proposed. The value of immunohistochemistry in the diagnosis of extranodal lymphoproliferative lesions is emphasized.

Adult↗
PubMed1987

Cystic medial necrosis in coarctation of the aorta: a potential factor contributing to adverse consequences observed after percutaneous balloon angioplasty of coarctation sites.

Percutaneous transluminal angioplasty has been shown to be both feasible and efficacious for the treatment of aortic coarctation. Recent reports, however, have indicated that the development of aortic aneurysms at or near the coarctation segment may complicate attempts to treat this lesion by catheter-based intervention. Accordingly, we examined the light microscopic features of coarctation segments excised at surgery (n = 31) or obtained at autopsy (n = 2) in 33 patients with coarctation of the aorta. Cystic medial necrosis, defined as depletion and disarray of elastic tissue, was observed in each of the 33 specimens. In the majority of coarctation specimens (22 of 33 or 67%) the extent of cystic medial necrosis, graded semiquantitatively on a scale of 0 (normal aorta) to 3+, was severe (3+). The finding that cystic medial necrosis represents a consistent histologic feature of coarctation of the aorta provides a pathologic basis for the formation of aneurysms observed after balloon angioplasty of coarctation sites.

Angioplasty, Balloon↗
PubMed1984

Completely cartilaginous trachea in a child with Crouzon syndrome.

We describe a patient with Crouzon syndrome and congenital tracheal stenosis. The trachea lacked rings and was completely cartilaginous, making it rigid and narrow. The respiratory difficulties that are present in patients with Crouzon syndrome have been ascribed to the nasal or choanal defects that are associated with this condition. However, the presence of congenital tracheobronchial abnormalities as a cause of respiratory problems has not been widely investigated. Congenital tracheal stenosis may occur as an isolated defect or as one of many other congenital defects. In patients with Crouzon syndrome who have recurrent respiratory problems, congenital tracheal or bronchial defects should be considered since surgical intervention may correct the defect.

Abnormalities, Multiple↗
PubMed1982

The child with peptic esophagitis: a correlation of radiologic signs with esophageal pathology.

Thirty-five children with gastroesophageal reflux were examined in a prospective study in which radiologic findings were correlated with the esophageal biopsy. No consistent radiologic abnormality was found in 24 children with minimal to moderate esophagitis and in three children with normal histology. Positive radiologic findings were found in five out of seven patients with severe, or severe ulcerative, esophagitis and in one child with moderate esophagitis. The positive radiologic findings consisted of signs of mucosal inflammation (mucosal edema, ulceration, esophageal narrowing) in five cases and abnormalities of esophageal function (aperistalsis, continuous reflux) in three. In children with peptic esophagitis, the barium examination of the esophagus appeared to be of diagnostic value only in the small number of patients with advanced disease; the absence of radiologic signs (with one exception) excluded severe inflammation. A statistically significant correlation was found between age and the histologic severity of esophagitis.

Adolescent↗