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Biomedical subjects

N Tyagi

Publications and source records attributed to N Tyagi.

At least 19 recordsLinked to original sources
PubMed2004

Proteomic analysis of homocysteine inhibition of microvascular endothelial cell angiogenesis.

Although homocysteine (Hcy) inhibits angiogenesis in vivo and in vitro, the mechanism(s) underlying this phenomenon are largely unclear. The hypothesis of the present work is that Hcy, while inducing the expression of antiangiogenic factors, inhibits the production of angiogenic factors. Mouse brain microvascular endothelial cells (MVEC) were cultured in the presence and absence of 20 microM Hcy for 24 hr in serum-free medium. Cell homogenates were incubated with Trans-Signal Angiogenesis Antibody Array containing antibodies to angiogenic activators (ANG, HGF, leptin, VEGF, IL-6, IL-8, PIGF, FGF-alpha/beta, TNF-alpha and TGF-alpha) and inhibitors (IFN-gamma, IL-12, IP-10, TIMP-1 and -2). The array membranes were scanned and normalized with positive controls. Angiogenesis and formation of capillaries were measured by culturing the MVEC in Matrigels. The capillary-like structures were identified by transmission microscopy. Hcy decreased the expression of leptin, IL-6, -8, PIGF, FGF-alpha and VEGF, while the levels of anti-angiogenic IL-12, IP-10 (chemokine) and TIMP-1 were increased by Hcy. The vascular tube-like structures by MVEC were decreased by increased Hcy. However, the addition of VEGF to Hcy-treated MVEC ameliorated the decreased Hcy-mediated capillary formation. The results suggest that Hcy inhibits angiogenesis, in part, by decreasing VEGF and increasing TIMP-1.

Animals↗
PubMed1997

Soft tissue tumours of eyelid.

Soft tissue tumours of eyelid constituted 28.9% of all eyelid tumours. Morphologically they were either vascular 32 cases (49.23%), neural 24 cases (36.92%), fibrous 6 cases (9.23%) or adipose tissue tumours 3 cases (4.62%). The age ranged from 1-30 years, haemangiomas and neurofibromas were present since birth. Upper eyelid was involved in 81.54% cases. Neurofibroma was associated with generalized lesions in 13.6% cases.

Adipose Tissue↗
PubMed1996

Tumours of eyelid: a clinicopathologic study.

A retrospective study of 207 cases of eyelid tumours and tumour like lesions, diagnosed histopathologically, was carried out for the period 1957 to 1991. There was a slight preponderance of males as the male/female ratio was 1.3:1. The age of the cases ranged from one to 80 years. Benign tumours were usually seen in the first two decades whereas the malignant tumours were common in the age group of 40 to 60 years. Malignancy was noticed in 85 cases (41.1%). Of these cases of malignant tumours, basal cell carcinoma was the commonest (38.8%) followed by sebaceous carcinoma (27.1%), squamous cell carcinoma (22.4%), basisquamous cell carcinoma (8.2%) and melanoma (3.5%). The ratio of basal cell carcinoma to squamous cell carcinoma was 1.74: 1. Of the 122 benign lesions common ones were vascular tumours (21.3%), neural tumours (18.0%), dermoid cysts (16.4%), squamous cell papilloma (13.1%) and naevi (12.3%).

Adolescent↗
PubMed1994

Malakoplakia of bone presenting as a pathological fracture.

A male aged 54 years presented with a pathological fracture of the right femur at the subtrochanteric level. The fracture site showed a lytic lesion with expansion of the bone, considered to be a metastasis. On histology, however, the area turned out to be malakoplakia of bone. The patient responded well to antibiotics and sulphonamides along with skeletal traction. This appears to be the fourth reported case of malakoplakia of bone.

Bone Diseases↗
PubMed1994

Surface epithelial tumours of the ovary.

Surface epithelial tumours (SET) constituted 65.7% of all the ovarian tumours. Benign tumours were 182 (71.9%), of low malignant potential (LMP) 11 (4.4%) and frank malignant 60 (23.7%). Maximum number of cases, 102 (40.3%) belonged to 3rd decade. Mean age for serous cystoma was 31.5% years as compared to 30.8 years for mucinous cystoma. The commonest presenting feature was the abdominal lump observed in 182 cases (71.9%) and pain in abdomen in 120 (47.4%). Serous cystomas were t he most frequent tumours and comprised of 32.21% of all the ovarian tumours or 46.01% of all the SET or 65.56% of all the cystic SET. Seventeen (11.7%) of serous tumours were bilateral. Mucinous cystomas constituted 14.55% of all the ovarian tumours or 30.8% of all the SET. These tumours were bulky (78.6%; 15 cm diameter) and multilocular (83.9%). Mucinous cystadenocarcinoma was the commonest malignant epithelial tum our (36.6%). Endometroid carcinoma comprised 3.65% of all the SET or 8.4% of all the ovarian malignancy. Squamous metaplasia was seen in one case whereas 2 cases were of mesodermal mixed tumour with heterologous element as rhabdomyosarcoma. Clear cell carcinoma, Brenner tumour and unclassified group constituted 0.79%, 1.18% and 1.58% of all SET respectively.

Adenocarcinoma, Clear Cell↗
PubMed1993

Solid tumours of the ovary.

One hundred seventeen solid ovarian tumours, diagnosed histologically during the period between 1971 and 1990, were studied. The overall incidence of solid ovarian tumours was 23.4% of all the ovarian tumours (500 cases) studied. Of 117 solid ovarian tumours 19 (16.2%) were benign and the rest 98 (83.8%) were malignant. Epithelial tumours were the commonest (28.2%) followed by germ cell tumours (22.2%), sex cord stromal tumours (21.4%), metastatic tumours (19.7%) and non-specific tumours (8.5%). The average age (26.8 years) was comparatively low for germ cell tumours otherwise in other groups it ranged between 42 and 45 years. Below 15 years immature teratoma was diagnosed in 4 cases and granulosa cell tumour in 2 cases. Bilateral tumours were seen in 22 cases (23.2%) out of 95 cases observed. Pain and fullness in the pelvic region were observed in 94.9% cases. Varied morphological picture was seen in 6 cases of endometrioid carcinoma. Dysgerminoma constituted 6.8% of solid ovarian tumours. Gliomatosis peritonei was noticed in one case of immature teratoma. Granulosa cell tumour accounted for 11.1% of solid ovarian tumours. Of 23 cases of metastatic tumours, Krukenberg tumour was noticed in 88.9% cases. Diagnostic problems as well as prognostic factors of solid ovarian tumours have been discussed.

Adolescent↗
PubMed1992

Stromal cellular response in breast tumours and allied lesions.

Histopathological study for stromal cellular response was made on 200 cases of benign and dysplastic lesions and malignancy of breast. Infiltrations with lymphocytes and plasma cells were observed in 64% cases of fibroadenoma, 66.6% cases of giant fibroadenoma, 61% cases of mammary dysplasia and 33.3% cases of gynaecomastia. While mast cell infiltration was not observed in giant fibroadenoma, its presence was observed in 92% cases of fibroadenoma, 77.8% cases of mammary dysplasia and 33.3% cases of gynaecomastia. Lymphocytes and plasma cells infiltrations were observed in 100% of cases of invasive duct carcinoma, medullary carcinoma and fibrosarcoma. Comedocarcinoma showed infiltration with these cells in 75% of cases while that for colloid carcinoma and Paget's disease of breast were observed in 50% of cases of each. Infiltrations with mast cells were observed in 92.3% cases of invasive duct carcinoma, 75% cases of comedocarcinoma and 25% cases of medullary carcinoma. Other malignant conditions of breast did not show mast cell infiltration. Degree of infiltration with lymphocytes and plasma cells was mainly of low grade in benign and dysplastic lesions compared to high degree of infiltration in malignancy. Mast cell infiltration was of low degree in both the types of lesions.

Adenofibroma↗
PubMed1992

Morphological changes in diseased gall bladder: a study of 415 cholecystectomies at Aligarh.

Morphological changes of gall bladder were studied in 415 cholecystectomy specimens. There was a preponderance of females (male to female ratio--1:6.5). The mean age of the cases was 43.6 years. Most of the cases (63.4%) were in the 4th and 5th decades of life. The average duration of illness was 2.8 years. Associated cholelithiasis was present in 85.3% cases. Gall-stones were of mixed variety in 78.2% cases, cholesterol type in 15.3% cases and both types were present in 6.5% cases. Chronic cholecystitis was the main histological diagnosis (50.8%). Other lesions observed were adenomyomatosis (8.2%), adenomatous hyperplasia (10.1%), granulomatous cholecystitis (4.1%), cholesterosis (2.7%), acute cholecystitis (4.1%), acute on chronic infection (10.8%), sub-acute cholecystitis (2.4%) and carcinoma gall bladder (6.8%). The frequency of Rokitansky-Aschoff's sinuses was closely related with the degree of inflammatory response. In 13 (6.2%) cases the diagnosis of chronic follicular cholecystitis was made. All the cases of cholesterosis were multiparous females and of younger age. Of the malignant lesions, adenocarcinoma was the commonest (96.4%).

Adult↗
PubMed1991

Chronic granulomatous cholecystitis: a clinicopathological study of 17 cases.

In a clinicopathological study of 376 cases of gall bladder diseases, chronic granulomatous cholecystitis was diagnosed in 17 specimens (4.52%). All these cases presented with pain in the right hypochondrium and a non-functioning gall bladder. Besides cholegranulomas and xanthogranulomas, 5 cases presented with localised yellowish brown areas in the wall of the gall bladder which revealed on histology proliferation of histiocytes containing abundant granular brown pigment (as seen in ceroid granulomas), intermingled with lymphocytes, plasma cells and occasional foreign body giant cells. The average age of the patients was 41.3 years. Cholelithiasis was present in 12 cases (70.6%). In one case the gall bladder was bilocular, having granulomatous lesion on one side of the septum and papillary adenocarcinoma on the other side.

Adult↗