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Biomedical subjects

K Singh

Publications and source records attributed to K Singh.

At least 37 records · Page 2Linked to original sources
PubMed2005

Patients with gallstones develop gallbladder cancer at an earlier age.

Significant proportions of Indian patients with gallbladder cancer are young. Multiple risk factors for gallbladder cancer are recognized among Indian patients. The effect of these risk factors on the age of development of gallbladder cancer is not known. We conducted a study to determine the influence of risk factors on the age at diagnosis of patients with gallbladder cancer and to assess the interactions between these risk factors. Patients with gallbladder cancer from two tertiary care institutions during the period 1994-2001 were prospectively studied. An ultrasound examination was done to look for the presence of gallstones. The influence of gender, gallstones, socio-economic status, smoking, residence in rural areas and in the Gangetic belt on the age at presentation was analysed using univariate analysis, logistic and linear regression analyses. The mean age of the 121 patients studied was 55+/-11.7 (SD) years. There were 51 (42%) patients aged less than 50 years. The younger patients (age < or =50 years) were more likely to have gallstones (88 versus 66%; P=0.008) and to have come from a lower socio-economic background (88 versus 71%; P=0.02) in comparison with older patients. However, there was no effect of the other risk factors. The independent determinants for younger age of patients with gallbladder cancer on logistic regression analysis were gallstones [odds ratio (OR) 4, 95% confidence interval (CI) 1.5-11; P=0.006] and lower socio-economic status (OR 3.1, 95% CI 1.1-8.6; P=0.03). On linear regression analysis, age at presentation was lowered by 5.6 years if there were associated gallstones. The mean age of patients with these two risk factors was significantly lower than that of those with one risk factor or no risk factor (52+/-12 years versus 57+/-11 years versus 61+/-9 years; P=0.007). In conclusion, the presence of gallstones and lower socio-economic status were both independently associated with a younger age at diagnosis of gallbladder cancer and their effect was additive.

Adult↗
PubMed2005

The teaching of obstetrics and gynaecology in Singapore from 1905 to the present.

Medical education commenced a century ago in 1905. In 1922, the Department of Midwifery and Gynaecology was established. This was renamed the Department of Obstetrics in 1951. Medical undergraduate curriculum in Obstetrics and Gynaecology has evolved and undergone radical changes. From a compulsory 11-week residential posting in Kandang Kerbau Hospital, medical students are now only expected to be resident when they are scheduled for night duties. Having been an examination subject by itself in the Final MBBS Examination, Obstetrics and Gynaecology has in the latest revised undergraduate medical curriculum been incorporated into the Surgical tract and has ceased to be evaluated as a subject on its own. In this review, the establishment of postgraduate training in Obstetrics and Gynaecology is traced over the last 50 years and the important changes over the years are described. The first local Master of Medicine (Obstetrics and Gynaecology) was awarded in 1971. Currently, the specialist training for Obstetrics and Gynaecology in Singapore spans a period of 6 years, comprising 3 years of basic structural training and 3 years of advanced structural training. Over the years, the Department of Obstetrics and Gynaecology, National University of Singapore, has played a pivotal role in the teaching of clinical and laboratory research. This has added substantially to Singapore's efforts to become a world-class knowledge hub, especially in the areas of relevance to Obstetrics and Gynaecology.

Education, Medical↗
PubMed2004

The difference between ultrasound and computed tomography (CT) measurements of aortic diameter increases with aortic diameter: analysis of axial images of abdominal aortic and common iliac artery diameter in normal and aneurysmal aortas. The Tromsø Study, 1994-1995.

OBJECTIVE: To assess agreement between ultrasound and computed tomography (CT) measurements from axial images of normal and aneurysmatic aortic and common iliac artery diameter. DESIGN: Part of a population health screening for abdominal aortic aneurysm conducted in 1994-1995. MATERIALS AND METHODS: Three hundred and thirty-four subjects with and 221 subjects without ultrasound-detected aneurysm were scanned with CT. Three technicians and one radiologist measured ultrasonographic diameters and five radiologists measured CT diameters. The paired ultrasound-CT measurement differences were analyzed to assess agreement. RESULTS: Compared to CT measurements, ultrasound slightly underestimated the diameter in normal aortas and tended to overestimate the diameter in aneurysmal aortas. In 555 ultrasound-CT pairs of measurements, the absolute differences for measurements of maximal aortic diameter were 2 mm or less in 62, 60 and 77% in anterior-posterior, transverse and maximum diameter in any plane, respectively. The corresponding figures for an absolute difference of 5 mm or more were 14, 18 and 8%, respectively. Variability increased with increasing diameter. CONCLUSIONS: Both ultrasound and CT measurements of abdominal aortic diameter are liable to variability and neither of these methods can be considered to be 'gold standard'. Both methods can be used, while taking variability into consideration when making clinical decisions.

Aged↗
PubMed2004

A role for schwann cells in the neuroregenerative effects of a non-immunosuppressive fk506 derivative, jnj460.

UNLABELLED: FK506 and its non-immunosuppressive derivatives represent a class of pharmacological agents referred to as immunophilin ligands that have been reported to promote neuroregeneration and survival in several experimental models; however their cellular and molecular mechanisms of action have not been well established. Here we characterize a new immunophilin ligand that interacts with both FK506 binding protein 12 (FKBP12) and FKBP52, and demonstrate that JNJ460 induces neurite outgrowth from freshly explanted dorsal root ganglia (DRG) in a Schwann cell-dependent manner. Purified cultures of neurons fail to respond to these drugs, but cultures containing Schwann cells and neurons respond with neurite outgrowth, as do neurons grown in conditioned medium from JNJ460-treated Schwann cells. Using microarray analysis and a transcription reporter assay, we show that JNJ460 induces a series of transcriptional changes that occur in a temporal cascade. Among the Schwann cell-expressed genes upregulated following JNJ460 treatment is the POU transcription factor SCIP, which has been shown to regulate Schwann cell gene transcription and differentiation. JNJ460 potentiated transforming growth factor beta (TGF-beta)-induced transcriptional activation and SCIP induction in Schwann cells, by altering the interaction between FKBP12 and the TGF-beta type I receptor, TbetaR1. Finally, to test whether JNJ460 enhances neurite regeneration in vivo, we treated animals with JNJ460 for 30 days following mechanical transection of the sciatic nerve and demonstrated myelin and axonal hypertrophy at the ultrastructural level. Collectively, these data suggest that Schwann cells play an important role in the biological effects of immunophilin ligands by affecting neuron-glial signaling during regeneration. SUMMARY: The cellular and molecular mechanisms responsible for the regenerative effects of immunophilin ligands are not well understood. Here we show that the neuritogenic effects of JNJ460 in a DRG model depend on interactions between neurons and Schwann cells. Treatment of purified Schwann cells with JNJ460 alters Schwann cell gene expression, and promotes the generation of factors that act on neurons. These data indicate that Schwann cells play an important role in the actions of immunophilin ligands.

Animals↗
PubMed2004

Analysis of cellular structure by light scattering measurements in a new cytometer design based on a liquid-core waveguide.

The results of applying a novel microfluidic optical cytometer to generate and observe the light scattered from biological cells over a wide range of angles are presented. This cytometer incorporates a waveguide that increases the intensity of the scattered light to the extent that an inexpensive digital camera can be used to detect the light over a large solid angle. This device was applied to yeast cells and latex beads and experimental data were compared with the results of a finite difference time-domain (FDTD) method of simulation. The simulated scattering patterns were calculated from reported values of optical parameters and are in good qualitative agreement with experiment. It is demonstrated that this system could be used to acquire information on the microstructure and potentially the nanostructure of cells.

Journal Article↗
PubMed2004

Radiological spectrum of late sequelae of corrosive injury to upper gastrointestinal tract. A pictorial review.

PURPOSE: To evaluate the radiological spectrum of sequelae of corrosive acid and alkali injury to the upper gastrointestinal (GI) tract using barium contrast examination. MATERIAL AND METHODS: Barium contrast radiographic films of 155 patients with a history of corrosive ingestion, acid in 120 and alkali in 35 patients with grade 2b and 3 injury on initial endoscopy, were retrospectively evaluated. Barium contrast examination of the upper GI tract was performed in the course of follow-up, beyond 3 weeks of corrosive ingestion. RESULTS: The esophagus was involved in 131 patients and the stomach in 74. Fifty patients had simultaneous involvement of esophagus and stomach. Radiological findings in the esophagus were solitary or multiple strictures of varying length, intramural pseudodiverticula, and carcinoma in long-standing corrosive injury. The stomach showed cicatrization, predominantly involving the antrum, linitis plastica type deformity with multiple pseudodiverticula. There was no difference in the radiological findings as to the type of corrosive ingested. CONCLUSION: Barium examination of the upper GI tract is useful in the evaluation of late sequelae of corrosive injury (acid/alkali). There was no difference in the radiological findings as to the type of corrosive ingested. Thus, contrary to general belief, we found that acid and alkali damage both the esophagus and the stomach with equal degree of severity.

Acids↗
PubMed2004

Intraductal pancreatic calculi in patients with choledochal cyst.

Summary Intraductal pancreatic calculi are a rare association in patients with choledochal cyst (CC). Reported herein is a retrospective analysis of the data on pancreatic calculi in 37 patients (10 children and 27 adults) who underwent endoscopic retrograde cholangiopancreatography (ERCP) for CC over a period of 15 years. Five patients (one child and four adults) were identified as having intraductal pancreatic calculi. Three had type I and two had type IV CC. Four underwent cyst excision. No intervention was carried out for the pancreatic calculi. There was no evidence of pancreatic insufficiency on follow up and none had recurrence of abdominal pain. One patient died of cholangitis, which was the initial presenting problem. Intraductal pancreatic calculi associated with CC, although uncommon, are not rare and are not always symptomatic.

Adolescent↗
PubMed2004

Contrast-free unilateral endoscopic palliation in malignant hilar biliary obstruction: new method.

BACKGROUND: Bilateral endoscopic drainage is difficult in malignant hilar biliary obstruction. Recently, unilateral drainage in malignant hilar biliary obstruction has been shown to be equally effective. However, contrast injection leads to cholangitis. There have been no reported studies on contrast-free metal stenting in malignant hilar biliary obstruction. The present study was undertaken to evaluate the results of contrast-free unilateral metal stenting in type II malignant hilar biliary obstruction. METHODS: We prospectively studied the results of unilateral metal stenting in type II malignant hilar biliary obstruction without contrast injection in 18 patients. RESULTS: A successful endoscopic drainage was achieved in 100% (18/18) of patients with hilar strictures. Cholangitis and 30-day mortality occurred in none. CONCLUSIONS: Unilateral endoscopic metal stenting without contrast in type II malignant hilar biliary obstruction is a safe and effective method of palliation.

Biliary Tract Neoplasms↗
PubMed2004

Goblet cell status in idiopathic ulcerative colitis--implication in surveillance program.

Idiopathic ulcerative colitis (IUC) patients have higher incidence of dysplasia and malignancy. Close follow-up with biopsy at regular interval is mandatory. The study was done to correlate incidence of atypical epithelium, goblet cell hyperplasia (GCH) and disease duration (DD) with Ki67, AgNOR and p53 expression in IUC with disease for 5 or more years. Ki67 and AgNOR are good indicators of cellular proliferation and p53 tumour suppressor protein is a marker for neoplastic cell. Of 130 cases studied, 40 cases showed atypical epithelium and were selected for further study. DD in these 40 cases ranged from 60 to 228 months. All had GCH and showed histological features of chronicity. Low-grade dysplasia (LGD) was seen in 15 cases, indefinite for dysplasia (ID) in 8 and inflammatory atypia in 17 cases. Disease duration showed no influence in the type of atypical epithelium. A positive staining of lining epithelium by Ki67 and p53 was not restricted to dysplasia. LGD and ID showed stronger p53 nuclear staining. AgNOR appeared to be a more sensitive marker than Ki67. GCH showed a positive correlation with DD and AgNOR index. p53 expression correlated positively with goblet cell hyperplasia. Conclusion- goblet cell hyperplasia could indicate presence of epithelial cell dysplasia.

Adolescent↗
PubMed2004

Effect of orthostatic stress on systolic time intervals in rabbits.

Systolic time intervals (STI) are sensitive indices of myocardial function. The present study was conducted to evaluate the effect of orthostatic stress on STI before and after 70 degrees head up tilt (HUT) in rabbits. Electrocardiogram (ECG), phonocardiogram and carotid arterial pulse were recorded simultaneously on four channel polyrite (INCO). Within 1 second of tilt there was a significant rise (P<0.001) in electromechanical systole (QS2), left ventricular ejection time (LVET), pre-ejection period (PEP), and ratio of PEP/LVET (P<0.01), however, there was no change in heart rate and mean arterial blood pressure insignificantly. QT/QS2 ratio and ejection fraction (EF) were also elevated (P<0.05) on tilt. After 20 seconds of HUT, QS2 showed reduction (P < 0.001), LVET elevation (P < 0.001), PEP and ratio of PEP/LVET reduction (P < 0.001) from control level. QT/QS2 and EF declined gradually towards basal values. These changes in STI (raised LVET, reduced PEP and PEP/LVET ratio) and increased QT/SQ2 ratio and EF pointed towards rise in contractility of heart.

Animals↗
PubMed2003

Endoscopic total extraperitoneal management of Amyand's hernia.

Presence of an appendix in a hernial sac (Amyand's hernia) is a rare entity, still rarer is an inflamed appendix within the hernial sac. An endoscopic total extraperitoneal repair of a right-sided incarcerated inguinal hernia is described. The inguinal hernial sac contained an inflamed appendix. An associated small incisional hernia at the lower end of a midline suprapubic scar for a Millin's prostatectomy was simultaneously repaired.

Aged↗
PubMed2003

Anorexia nervosa and pelvic floor dysfunction.

Pelvic floor dysfunction in women with eating disorders is an underexplored area. We present a case of pelvic floor dysfunction in a nulliparous woman with anorexia nervosa.

Anorexia Nervosa↗
PubMed2003

Risk factors for antibiotic-resistant infection and treatment outcomes among hospitalized patients transferred from long-term care facilities: does antimicrobial choice make a difference?

A prospective observational study of 153 patients transferred from long-term care facilities and admitted to acute-care hospitals who had microbiologically confirmed infections was undertaken to determine the risk factors, outcomes, and resource use associated with isolation of antibiotic-resistant bacteria (ARB). Eighty patients (52%) were infected with ARB. In multivariable logistic analysis, the presence of a feeding tube (odds ratio, 3.0) or polymicrobial infection (odds ratio, 4.6) was associated with isolation of ARB. Forty-nine percent of patients infected with ARB received an initial antibiotic regimen to which their isolate was not susceptible. Fifty-one percent of all patients had a change in their antibiotic regimen during their hospital course. For these patients, length of stay, number of days of antibiotic therapy, and cost of hospitalization were significantly higher. However, neither infection with ARB nor appropriateness of initial treatment regimen was significantly related to outcome or resource use.

Aged↗
PubMed2003

Idiopathic cases of male infertility from a region in India show low incidence of Y-chromosome microdeletion.

Chromosomal and Y-chromosomal microdeletion analysis has been done in cases of idiopathic infertility with the objective of evaluating the frequency of chromosomal and molecular anomaly as the causal factor of infertility. Barring a few cases of Klinefelter syndrome (XXY or XY/XXY mosaics), no chromosomal anomaly was encountered. Y-microdeletion was analysed by PCR-screening of STSs from different regions of the AZF (AZFa, AZFb, AZFc) on the long arm of the Y, as well as by using DNA probes of the genes RBM, DAZ (Yq), DAZLA (an autosomal homologue of DAZ) and SRY (Yp; sex determining gene). Out of 177 cases examined, 9 (azoospermia - 8 and oligoasthenospermia - 1) showed partial deletion of AZF. The size of deletion varied among patients but AZFc was either totally or partially removed in all of them. In contrast, no deletion was detected in AZFa. Testis biopsy done on a limited number of cases (50) showed diverse stages of spermatogenic arrest with no specific correlation with the genotype. The frequency of Y-chromosome microdeletion in our samples (approximately 5%) is much lower than the frequency (approximately 10%) reported globally and the two previous reports from India. We contend that the frequency may be affected by population structures in different geographical regions.

Biopsy↗