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B Niranjan

Publications and source records attributed to B Niranjan.

10 recordsLinked to original sources
PubMed2002

A comparative study of modified radical mastectomy using harmonic scalpel and electrocautery.

AIM: The harmonic scalpel is recently emerging as an alternative surgical tool for dissection and haemostasis and has been extensively used in the field of minimally invasive surgery. We studied the utility and advantages of this instrument over electrocautery for performing modified radical mastectomy. METHODS: The operative and morbidity details of twenty-three breast cancer patients who underwent modified radical mastectomy using the harmonic scalpel were compared with 23 matched controls operated with electrocautery by the same surgical team. RESULTS: There was no significant difference in the operating time between the harmonic scalpel and electrocautery group (104 and 100 mins, p > 0.05). The blood loss (60 +/- 35 ml and 294 +/- 155, p < 0.001) and drainage volume (590 +/- 430 ml and 1,085 +/- 690 ml, p < 0.001) were significantly lower in the harmonic scalpel group. There was a significant reduction of drain days in harmonic scalpel group (mean five and nine days, p < 0.05). There was no significant difference in the seroma rate between two groups (16% and 22%). CONCLUSION: Modified radical mastectomy using harmonic scalpel is feasible and learning curve is short. Harmonic scalpel significantly reduces the blood loss and duration of drainage as compared to electrocautery.

Adult↗
PubMed2001

Loss of cyclin D2 expression in the majority of breast cancers is associated with promoter hypermethylation.

Cyclin D2 is a member of the D-type cyclins, implicated in cell cycle regulation, differentiation, and malignant transformation. It was noted previously that cyclin D2 is not expressed in the majority of breast cancer cell lines, whereas abundant expression was detected in finite life span human mammary epithelial cells. By reverse transcription-PCR and Western blot analysis, we extended this finding to primary breast carcinomas and show that the majority of these tumors lack expression of cyclin D2 mRNA (18 of 24) and protein (10 of 13). In contrast, both luminal and myoepithelial subpopulations of normal breast tissues expressed cyclin D2. Hypermethylation of the CpG island in the promoter was detected by methylation-specific PCR in nearly half of the breast cancers (49 of 106) and was associated with silencing of cyclin D2 gene expression. Promoter hypermethylation was also detected in ductal carcinoma in situ, suggesting that loss of cyclin D2 expression is an early event in tumorigenesis. Our results suggest that loss of cyclin D2 expression is associated with the evolution of breast cancer.

Blotting, Western↗
PubMed2001

Wilms' tumor suppressor gene (WT1) is expressed in primary breast tumors despite tumor-specific promoter methylation.

We analyzed Wilms' tumor suppressor 1 (WT1) expression and its regulation by promoter methylation in a panel of normal breast epithelial samples and primary carcinomas. Contrary to previous reports, WT1 protein was strongly expressed in primary carcinomas (27 of 31 tumors) but not in normal breast epithelium (1 of 20 samples). Additionally, the WT1 promoter was methylated in 6 of 19 (32%) primary tumors, which nevertheless expressed WT1. The promoter is not methylated in normal epithelium. Thus, although tumor-specific methylation of WT1 is established in primary breast cancer at a low frequency, other transcriptional regulatory mechanisms appear to supercede its effects in these tumors. Our results demonstrate expression of WT1 in mammary neoplasia, and that WT1 may not have a tumor suppressor role in breast cancer.

Breast↗
PubMed2001

Vertical rectus abdominis myocutaneous flap cover for lower abdomen, chest wall, groin and thigh defects following resection of malignant tumours.

Vertical rectus abdominis mycutaneous (VRAM) flap provides a reliable flap cover for large soft tissue defects of chest wall, torso, groin, perineum and thigh. It has been mainly used in trauma and benign conditions. Between January 1994 through January 1999, eight patients with locally advanced malignant tumors underwent radical resection and reconstruction using pedicled VRAM flap. Inferiorly based VRAM flap was used in five patients and superiorly based VRAM flap in three patients. Defect size ranged from 144 to 900 CM2. (mean 386 cm2). Average blood loss for combined resection and reconstruction was 600ml. (range 400-800 ml.) Primary closure of both donor and recipient sites achieved in all patients. There was no wound infection, flap necrosis or abdominal hernia. There patients received postoperative radiotherapy and chemotherapy and two patients received radiotherapy only. All the the patients are alive and free of local recurrence at mean follow up 32 months. Results of our study shows that VRAM flap is versatile and sturdy flap with a wide are of rotation and it can reach diverse anatomical sites like torso, chestwall, thigh and perineum to cover large defects following radical resection for tumors.

Adult↗
PubMed1999

HGF/SF in mammary epithelial growth and morphogenesis: in vitro and in vivo models.

HGF/SF is a multifunctional cytokine which through binding to its cellular receptor, c-MET, can elicit mitogenic, morphogenic and motogenic responses in target cells. Expression of HGF/SF and c-MET has been shown to be critical in early embryogenesis affecting development of many organs and tissues. The effects of HGF/SF4 on established human and mouse mammary cell lines have previously been reported. This review describes the source and targets for HGF/SF in both human and mouse mammary tissue and discusses the effects of HGF/SF on primary mouse and human mammary epithelial cells in vitro, detailing the individual response of the two epithelial sub-population of cells which comprise this organ. Additionally, the effects of HGF/SF overexpression on mouse mammary gland development in vivo, are summarized.

Animals↗
PubMed1998

In vivo effects of hepatocyte growth factor/scatter factor on mouse mammary gland development.

We have recently demonstrated the regulated expression of HGF/SF and its receptor (c-met) during mouse mammary gland development together with the mitogenic, motogenic and morphogenic effects of exogenous HGF/SF on primary mammary epithelial cells in culture. This study was undertaken to analyze the influence of HGF/SF on reconstituted mouse mammary gland development in vivo. Here we report that overexpression of HGF/SF induces a range of alterations in the architecture of virgin mouse mammary gland. These include an enhancement of ductal end bud (mammary gland morphoregulatory control point) size and numbers and hyperplastic branching morphogenesis. These data are the first demonstration of the effects of HGF/SF on mammary epithelium in vivo.

Animals↗
PubMed1996

Inhibitory effects of activin on the growth and morpholgenesis of primary and transformed mammary epithelial cells.

Activin is a member of the transforming growth factor beta superfamily, which is known to have activities involved in regulating differentiation and development. By using reverse transcription-PCR analysis on immunoaffinity-purified human breast cells, we have found that activin beta a and activin type II receptor are expressed by myoepithelial cells, whereas no expression was detected in other breast cell types. In examining 15 breast cell lines, we have found only four (HBL-100, MCF10-A, PMC-42, and BT 20) to be positive for activin beta a mRNA, whereas all expressed the activin type II receptor. Furthermore, we have found activin A to be a potent growth inhibitor of MCF- 7 cells (at 2 ng/ml), where it causes an arrest in G(1). Activin A does not appear to have an effect on the cell cycle of primary myoepithelial or luminal cells. However, we demonstrate that activin is an inhibitor of tubule formation by human mammary organoids in vitro. These are the first observations of activin and activin receptor in the normal human breast and in human breast cell lines and suggest a role for activin in mammary cell growth and morphogenesis.

Activins↗
PubMed1995

HGF/SF: a potent cytokine for mammary growth, morphogenesis and development.

The mammary gland is a renewing tissue in which morphogenetic processes and differentiation occur cyclically during the menstrual cycle, pregnancy and lactation. These events have been shown to be dependent upon epithelial-mesenchymal interactions. Studies of the effects of individual factors, their cellular source and their target cell populations in the different developmental stages of the mammary gland are greatly facilitated by the accessibility of this organ and the application of new techniques that allow purification of the major epithelial and stromal components of this tissue. Here we demonstrate that HGF/SF and its cellular receptor, c-met, are expressed and regulated temporally during mouse mammary development and differentiation. We show that human and mouse mammary fibroblasts produce HGF/SF and that HGF/SF is not only mitogenic but morphogenic and motogenic for both human and mouse mammary epithelial cells. We have found that human luminal and myoepithelial cells express c-met differentially and that HGF/SF has different effects on these two mammary epithelial cell populations. HGF/SF is mitogenic for luminal cells but not myoepithelial cells, and morphogenic to myoepithelial cells but not luminal cells. This is discussed in the context of the proliferative compartments in the normal mammary gland and the potential role of the myoepithelial cells to act as the skeleton for ductal development.

Animals↗
PubMedDate not supplied

Symptomatic outcome after laparoscopic cholecystectomy.

AIMS: Patients with gallstones often present with multiple complaints. We wanted to study the major complaints of our patients undergoing laparoscopic cholecystectomy and the symptomatic relief afforded by the operation. METHODS: We studied 113 patients with symptomatic gallstone disease who underwent laparoscopic cholecystectomy in a single surgical unit. Patients with proven common bile duct stones, obstructive jaundice, cholangitis, present or past associated abdominal pathology or cholecystoenteric fistula were excluded from the study. The mean follow up period was 18 months (range 10-22 months). A detailed account of the symptoms of gallstones, length of post-operative stay, persistence of symptoms, development of fresh symptoms and resumption of fat containing diet were assessed. RESULTS: The male to female ratio was 1:4. Common presenting symptoms were abdominal pain (96%), flatulence or feeling of fullness of abdomen (85%), heartburn (66%), belching (62%), sour eructation (52%), vomiting (48%) and nausea (45%). Mean postoperative hospital stay was 28 hours (range 9-68 hours). Biliary pain was relieved in 99% of patients after laparoscopic cholecystectomy (p < 0.001). The non-pain symptoms which are relieved significantly (p < 0.001) included nausea (98%), vomiting (96%) and sour eructation (92%) had better outcome than belching (64%) flatulence (61%) and heart burn (59%). None of the patients developed jaundice after cholecystectomy. Fresh symptoms that developed after laparoscopic cholecystectomy were heart-burn (6%), belching (3.5%), sour eructation (1%) and vomiting (0.5%). Post-cholecystectomy post-prandial diarrhoea occurred in 20% of the patients. The patients' appreciation of a satisfactory cosmetic result of operation scars was 100 percent. Fifteen female patients (13.5%) complained of increased weight gain of more than 5 kg after laparoscopic cholecystectomy [(p > 0.05; not significant (NS)]. CONCLUSION: Laparoscopic cholecystectomy significantly relieved symptoms of gall stone disease. Biliary pain, nausea, vomiting and sour eructations had better outcome compared to belching, flatulence and heartburn, which are also relieved in majority. Postcholecystectomy post-prandial diarrhea was a significant new symptom after cholecystectomy. Pre-operative flatulence and heartburn are risk factors for poor symptom relief. All patients should be pre operatively counselled about the risk of persistence of some non-pain symptoms after laparoscopic cholecystectomy.

Adolescent↗