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Biomedical subjects

N Singh

Publications and source records attributed to N Singh.

At least 55 records · Page 3Linked to original sources
PubMed2004

Virilisation in a case of transitional cell carcinoma of the ovary.

A 52 year old woman presented with a five month history of emotional changes, voice changes, and of abdominal discomfort. Clinical, biochemical, and radiological examinations showed evidence of virilisation, raised testosterone, and a complex ovarian mass. Microscopy of the resection specimen showed the tumour to be a transitional cell carcinoma of the ovary with luteinisation and hyperplasia of the intervening stromal cells. This is a unique case of virilisation caused by transitional cell carcinoma of the ovary. Theories as to the origin of testosterone production in non-functioning ovarian tumours are discussed.

Carcinoma, Transitional Cell↗
PubMed2004

Evaluation of expression of apoptosis-related proteins and their correlation with HPV, telomerase activity, and apoptotic index in cervical cancer.

OBJECTIVE: The aim of this study was to examine the expression of apoptosis-related proteins in cervical cancer, and investigate their correlation with the apoptotic index (AI), telomerase activity, human papilloma virus (HPV) infection and clinicopathological characteristics. METHODS: Fifty cervical cancer samples and 20 normal cervical tissues were assessed for the protein expression of survivin, Bcl-2, Cox-2, p53 and p73 by immunohistochemistry. HPV DNA was detected by PCR, telomerase activity by PCR-ELISA, and AI by TUNEL assay. RESULTS: 46/50 cervical tumors (92%) showed an increased telomerase activity as compared to 3/20 (15%) controls. 45/50 (90%) cervical tumors were positive for HPV, of which 30 were HPV-16 positive and 5 were HPV-18 positive. 24/50 (48%) tumors were positive for survivin, 14 (28%) for Bcl-2, 13 (26%) for Cox-2, 19/45 (42%) for p73, 10/45 (24%) for p53. Telomerase activity was highest in tumors with the poorest grade. A positive correlation was seen between survivin and Bcl-2, survivin and tumor stage, Bcl-2 and Cox-2, p73 and p53 and p73 and the AI. Despite the overexpression of various antiapoptotic proteins, no significant difference was observed in the AI between tumors and controls. CONCLUSIONS: Since deregulation of the apoptotic pathway appears to occur in cervical cancer, some apoptosis-related proteins could be assessed as potential markers for progression/prognosis in cervical cancer. Additionally, newer proteins such as p73 may play a compensatory role for the nonfunctional proteins such as p53.

Adult↗
PubMed2003

Hydrolysis of fenamiphos and its oxidation products by a soil bacterium in pure culture, soil and water.

A bacterium, identified as Brevibacterium sp. MM1, readily hydrolysed fenamiphos, a widely used organophosphorus insecticide and its toxic oxides (fenamiphos sulfoxide, fenamiphos sulfone), which all contain a common P-O-C bond, in a mineral salts medium. The bacterium also hydrolysed fenamiphos and its oxides in soil and groundwater. Interestingly, fenamiphos phenol, fenamiphos sulfoxide phenol and fenamiphos sulfone phenol, formed during bacterial hydrolysis of fenamiphos and its oxides, persisted in the mineral salts medium, but were transitory in soil and groundwater due to their further metabolism by indigenous micro-organisms. The cell-free preparation (crude enzyme) of this bacterium was very effective in hydrolysing fenamiphos. This is the first report on exceptionally rapid hydrolysis of fenamiphos by a bacterium in pure cultures, soil and groundwater.

Brevibacterium↗
PubMed2003

Serum sialic acid, a reputed cardiovascular risk factor, is related to serum leptin concentrations in Fijians.

BACKGROUND: Serum sialic acid (TSA) has been shown to be a cardiovascular risk factor and an acute phase reactant, with elevated concentrations associated with increased cardiovascular mortality and to precede the onset of type 2 diabetes. AIM: The purpose of this present study was to test the hypothesis that serum TSA may be related to serum leptin concentrations in healthy individuals. METHODS: Thirty Fijian individuals were studied (8 males and 22 females). They were urban Melanesians living in Raiwaga, a suburb of Suva in Fiji. RESULTS: Serum TSA significantly correlated with subject body mass index (BMI, rho 0.39, P<0.05) and serum leptin concentration (rho 0.44, P<0.05). In stepwise multiple regression analysis serum TSA independently correlated with subject waist/hip ratio (r(2)=0.167, P<0.02) and diastolic blood pressure (r(2)=0.300, P<0.01) but not with age, BMI, serum insulin-like growth factor binding protein (IGFBP-1), fasting plasma glucose or systolic or diastolic blood pressure. CONCLUSIONS: Serum TSA is related to markers of obesity and adipose tissue metabolism which may help to explain why it is a reputed cardiovascular risk factor and why elevated serum TSA concentrations precede the development of type 2 diabetes mellitus.

Adult↗
PubMed2003

Inadequate rates are lower when FNAC samples are taken by cytopathologists.

Inadequate rates (IR) in FNAC from different sources were compared. The rates were lowest when FNAC was performed by a cytopathologist (12%) and highest when done by a non-cytopathologist (32%). These differences were mirrored in high IRs in breast cancer cases. IR was not significantly improved when non-cytopathologist FNAC was attended by a cytotechnician.

Biopsy, Fine-Needle↗
PubMed2003

Changing epidemiology and predictors of mortality in patients with spontaneous bacterial peritonitis at a liver transplant unit.

OBJECTIVES: To determine whether antimicrobial resistance in pathogens and outcome in patients with spontaneous bacterial peritonitis (SBP) has evolved over time. METHODS: Sixty-one consecutive episodes of SBP were studied in patients with end-stage liver disease undergoing evaluation for liver transplantation between 1991 and 2001. Patients were dichotomized into a cohort between 1991 and 1995 (the earlier cohort) and 1996-2001 (the later cohort). RESULTS: Overall, 19% of all bacteria were multiply-antibiotic resistant. The frequency of multiple-antibiotic resistance in bacteria increased from 8.3% to 38.5% in the earlier as compared to the later cohort (P = 0.07). Overall, mortality at 30 days in the study patients was 26% and had remained unchanged between the two cohorts. The mortality rate was significantly higher in patients with multiply-antibiotic-resistant bacteria than in those with other bacteria (P = 0.045). However, the Child-Pugh score (P = 0.003), and renal failure (P = 0.04) were the only independently significant predictors of mortality in patients with SBP. CONCLUSIONS: Mortality in patients with end-stage liver disease who developed SBP has remained unchanged over the last decade. Although multiple-antibiotic resistance in bacteria causing SBP has increased over time, the severity of hepatic and renal dysfunction were the predominant determinants of outcome in these patients.

Adult↗
PubMed2003

Retroperitoneoscopic deroofing of a giant renal cyst in a solitary functioning hydronephrotic kidney with a 3-port technique.

To explore the safety and feasibility of performing retroperitoneoscopic renal cystectomy in a case of massive giant renal cyst in a solitary hydronephrotic renal unit. We have described the retroperitoneal three-trocar technique. The role of laparoscopic renal cyst ablation in giant symptomatic renal cysts and non-polycystic kidney disease has been discussed. The patient was successfully managed by retroperitoneoscopic deroofing using a three-port technique. The operating room time was 90 minutes and her hospital stay lasted 54 hours. The fluid cytology and cyst histology were negative for tumor. Complete resolution of the cyst was noted on a follow-up ultrasound done after 2 months. Currently at 9-month follow up, the patient is ultrasonographically free of any cyst recurrence or hydronephrosis. The retroperitoneal approach is feasible for marsupializing giant symptomatic renal cysts and appears to be safe for solitary symptomatic renal units too. It shortens the overall operating time and avoids the complications and demerits of transperitoneal access.

Aged↗
PubMed2003

Detection of tumour lymphovascular space invasion using dual cytokeratin and CD31 immunohistochemistry.

BACKGROUND: Lymphovascular space invasion (LVSI) is an important step in the complex process of tumour metastasis. Various methods have been used in the past to improve the histological detection of LVSI. AIMS: To develop a sensitive immunohistochemical method for the detection of LVSI. METHODS: Paraffin wax blocks from 108 patients who had undergone hysterectomy for stage I endometrial cancer were retrieved. Dual immunostaining for pancytokeratin and the CD31 endothelial cell marker was carried out on 4 micro m sections cut from these bocks and compared with conventional haematoxylin and eosin staining. RESULTS: The detection rate for LVSI increased threefold compared with conventional haematoxylin and eosin staining in the test group. CONCLUSION: This finding suggests that LVSI is a much more common phenomenon than previously thought and questions current understanding of tumour metastasis.

Biomarkers, Tumor↗
PubMed2003

The hospital- and field-based performances of the OptiMAL test, for malaria diagnosis and treatment monitoring in central India.

The performance of the OptiMAL test, to detect and differentiate Plasmodium falciparum and P. vivax, was evaluated in central India. The subjects were either symptomatic patients, who presented at a referral hospital in urban Jabalpur, or the inhabitants of remote, tribal, forested villages where malaria is a major public-health problem. In each setting, the results of conventional microscopy were used as the 'gold standard'. Under hospital conditions, the test had excellent sensitivity (100%), good specificity (97%), a high positive predictive value (98%) and a high negative predictive value (100%). The corresponding values in the field-based study in the tribal villages (100%, 67%, 84% and 100%, respectively) were almost as good. The results of OptiMAL testing reveal the decline in parasitaemias (of P. falciparum or P. vivax) after drug administration. For monitoring the effectiveness of treatment, the test could therefore be a useful alternative to microscopy, particularly (1) in places where the facilities for microscopy are poor or non-existent and (2) among hospitalized patients with severe, complicated malaria (in whom parasitaemia and drug response need to be followed very carefully). Follow-up (within 28 days of diagnosis) of the 58 malaria cases detected in the field revealed that the OptiMAL test can be used to detect re-infection with a different Plasmodium sp. (sensitivity = 100%; specificity = 100%; J-index = 1) or recrudescence/re-infection with the same Plasmodium sp. (sensitivity = 83%; specificity = 100%; J-index = 0.83) accurately. The ability to use the test to distinguish P. falciparum from P. vivax, and to identify mixed infections of these two species, is of great significance in areas where the preferred and effective therapy for P. falciparum malaria differs from that for P. vivax.

Adult↗
PubMed2003

Effect of thymosin-alpha1 on the production of nitric oxide by tumor-associated macrophages.

The present investigation was conducted to study the effect of thymic peptide: thymosinalpha1 (thyalpha1) on the activation of tumor associated mphi (TAM) obtained from mice bearing a transplantable T cell lymphoma of spontaneous origin designated as Dalton's lymphoma, to produce nitric oxide (NO). It was found that in vivo administration of aqueous thymic extract obtained from thymus of normal mice or thyalpha1 could activate the TAM to produce enhanced amount of NO which was further augmented on in vivo treatment of these TAM by LPS. These observations suggest that thyalpha1 could prime TAM for activation by second signal of LPS. The study also presents evidence that tumor cell elaborate factors that enhance the effect of thyalpha1 on TAM for production of NO. This is the first study to show that thyalpha1 can activate TAM directly even in the absence of LPS, and may, therefore, have clinical significance.

Animals↗
PubMed2002

Effects of age on brain volume and head circumference in autism.

OBJECTIVE: To determine whether brain volume, as assessed on MRI scans, differs between individuals with autism and control subjects, and whether such differences are affected by age. BACKGROUND: Previous studies have found increased brain weight, head circumference, and MRI brain volume in children with autism. However, studies of brain size in adults with autism have yielded conflicting results. The authors hypothesize that enlargement of the brain may be a feature of brain development during early childhood in autism that normalizes with maturational processes. METHODS: The authors measured total brain volumes from 1.5-mm coronal MRI scans in 67 non-mentally retarded children and adults with autism and 83 healthy community volunteers, ranging in age from 8 to 46 years. Head circumference was also measured. Groups did not differ on age, sex, verbal IQ, or socioeconomic status. RESULTS: Brain volumes were significantly larger for children with autism 12 years old and younger compared with normally developing children, when controlling for height. Brain volumes for individuals older than age 12 did not differ between the autism and control groups. Head circumference was increased in both younger and older groups of subjects with autism, suggesting that those subjects older than age 12 had increased brain volumes as children. CONCLUSIONS: Brain development in autism follows an abnormal pattern, with accelerated growth in early life that results in brain enlargement in childhood. Brain volume in adolescents and adults with autism is, however, normal, and appears to be due to a slight decrease in brain volume for these individuals at the same time that normal children are experiencing a slight increase.

Adolescent↗
PubMed2002

Vascular phenotype in angiogenic and non-angiogenic lung non-small cell carcinomas.

We have previously described a group of non-small cell lung carcinomas without morphological evidence of neo-angiogenesis. In these tumours neoplastic cells fill up the alveoli and the only vessels present appear to belong to the trapped alveolar septa. In the present study we have characterised the phenotype of the vessels present in these non-angiogenic tumours, in normal lung and in angiogenic non-small cell lung carcinomas. The vessels, identified by the expression of CD31, were scored as mature when expressing the epitope LH39 in the basal membrane and as newly formed when expressing alphaVbeta3 on the endothelial cells and/or lacking LH39 expression. In the nine putative non-angiogenic cases examined, the vascular phenotype of all the vessels was the same as that of alveolar vessels in normal lung: LH39 positive and alphaVbeta3 variable or negative. Instead in 104 angiogenic tumours examined, only a minority of vessels (mean 13.1%; range 0--60%) expressed LH39, while alphaVbeta3 (in 45 cases) was strongly expressed on many vessels (mean 55.5%; range 5--90%). We conclude that in putative non-angiogenic tumours the vascular phenotype is that of normal vessels and there is no neo-angiogenesis. This type of cancer may be resistant to some anti-angiogenic therapy and different strategies need to be developed.

Carcinoma, Non-Small-Cell Lung↗