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Biomedical subjects

P Singh

Publications and source records attributed to P Singh.

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

Improved HPLC method for the simultaneous determination of allantoin, uric acid and creatinine in cattle urine.

An HPLC procedure developed for the rapid and simultaneous determination of purine derivatives (PD) in ruminants' urine was investigated, since the adoption of a single method for the simultaneous detection of PD and creatinine was not carried out due to elution of polar co-extractives and also due to overlapping of the peaks of allantoin and creatinine. The experimental conditions chosen in the present study avoid the presence of chemically competitive compounds and afford a good separation of the peaks of allantoin and creatinine. The recoveries of the standard compounds added to urine samples were 94-104%. This method can be proposed as a possible reference method for the estimation of allantoin, uric acid and creatinine in cattle urine.

Allantoin↗
PubMed2005

The effect of citrate, oxalate, acetate, silicate and phosphate on stability of synthetic arsenic-loaded ferrihydrite and Al-ferrihydrite.

The effect of the organic species oxalate, citrate and acetate and the inorganic species silicate and phosphate on release of As(V) from synthetic arsenic-loaded ferrihydrite and Al-ferrihydrite in the pH range 4-8 was investigated. For ferrihydrite, the organic species increased %As(V) extraction in the order: acetate PO4(3-). Competitive adsorption of the investigated organic and inorganic species on ferrihydrite and Al-ferrihydrite could explain the enhanced release of As(V) into solution. However, disproportionate adsorption of other species relative to amount of As(V) release occurs, suggesting that mechanisms other than competitive adsorption are also operative. The results could best be explained in terms of combination of competitive adsorption and processes involving pH-dependent dissolution of ferrihydrite/Al-ferrihydrite, formation of various complex ionic species involving Al(III), Fe(III), As(V), SiO3(2-), PO4(3-), OH-, H+ and organic species: acetate, oxalate and citrate.

Acetates↗
PubMed2005

Trapping force on a finite-sized particle in a dielectrophoretic cage.

The point dipole (PD) model is routinely used for estimating the dielectrophoretic (DEP) force acting on a particle placed in the nonuniform electric fields of dielectrophoresis devices, such as square cages. We show that if the particle size is much smaller than the dielectrophoretic cage size, the PD model accurately approximates the actual DEP force, computed numerically using the Maxwell stress tensor method. However, when the two sizes are comparable, the actual DEP force differs significantly in both magnitude and direction from that given by the PD model.

Journal Article↗
PubMed2005

Common cancers in India: knowledge, attitudes and behaviours of urban slum dwellers in New Delhi.

RESEARCH QUESTIONS: What is the level of knowledge and awareness of common cancers? What are the prevalent attitudes and behaviours relating to common cancers? OBJECTIVES: To assess knowledge, attitudes and behaviours regarding common cancers amongst urban slum dwellers in New Delhi. STUDY DESIGN: Field-based cross-sectional survey of an urban slum cluster. SETTING: Slum clusters along Pankha Road, West New Delhi. PARTICIPANTS: Slum dwellers of selected slums. STUDY VARIABLES: Independent variables were sociodemographic factors. Dependent variables were knowledge, attitudes and behaviours regarding preventive and curative aspects of common cancers. STATISTICAL ANALYSIS: Proportions, confidence intervals, tests of significance and multiple logistic regression. RESULTS: Only 13% (10.6-15.7%) of the study participants were aware of Pap smears, and only 2% (1.1-3.3%) were able to identify all the common signs of cancer. However, 87% (84.4-89.5%) of the study participants knew that tobacco is a risk factor for cancer. Overall, 51% (47.2-54.7%) had some knowledge pertaining to cancer. CONCLUSION: A focused, concerted and effective information, education and communication drive is urgently needed for all aspects of common cancers in India.

Adolescent↗
PubMed2005

Oesophageal foreign bodies at the University Hospital of the West Indies.

A retrospective study was conducted of 97 patients with oesophageal foreign bodies (EFB). The patients were admitted to assess characteristics of EFB, modes of presentation and radiological and endoscopic findings. The patients were from the University Hospital of the West Indies and most (42%) were over the fourth decade of life. The commonest EFB were bones. A negative radiological finding was not a reliable means to select patients for endoscopy. Oesophagoscopy is a reliable method in the treatment of EFB impaction. There were no major complications or deaths.

Bone and Bones↗
PubMed2005

The effect of Hurricane Ivan on Emergency Department operations at the University Hospital of the West Indies.

The objective of this study was to determine the impact of Hurricane Ivan on the operations of the Emergency Department (ED) at the University Hospital of the West Indies (UHWI). Hurricane Ivan,--a category four Hurricane--traversed the south coast of the island of Jamaica on September 10, 2004, causing damage to several parishes. The study design is a descriptive retrospective record-based incidence study of all admissions to the ED commencing at 8:00 am September 10, 2004 and ending at 12 midnight September 11, 2004, covering the period of the entire duration of the hurricane as well as immediately after. Injuries that took place during the hurricane, inclusive of gun-shot wounds (GSWs) represented 40% of the total patients seen. The types of admission are listed categorically as well as specific items to be considered in planning for potential disasters of higher magnitude. Overall, the coping mechanism of the ED at UHWI was adequate for this magnitude of disaster.

Adult↗
PubMed2005

Using IMAP technology to identify kinase inhibitors: comparison with a substrate depletion approach and analysis of the nature of false positives.

IMAP is a fluorescence polarisation-based assay method which can be applied to the measurement of protein kinase activity. Using a model serine/threonine kinase we found that IMAP generated a good assay window (Z' > 0.8), was very tolerant of DMSO, and was flexible with respect to sample processing (stopped reactions were stable over a period of several days). Using a set of six low molecular weight inhibitors of the kinase, we found a good correlation between IMAP and scintillation proximity assay (SPA) potency data. IMAP, which measures product accumulation, was compared in an HTS setting with a substrate depletion method (luminescence-based measurement of ATP concentration). There was a reasonable (approximately 50%) overlap in primary hits from a 17,000 compound set, but more apparent false positives were generated from the IMAP method. We followed up the compounds that showed activity in the IMAP method but not in the luminescence assay. Approximately 10% of these compounds displayed intrinsic fluorescence, suggesting that they were false actives by virtue of intrinsic spectroscopic properties. Compound activity by competition of phosphopeptide binding to IMAP beads can occur with high concentrations of chelating compounds, but did not occur with any of the false actives, suggesting that this form of interference is rare.

Adenosine Triphosphate↗
PubMed2005

Effects of xylazine, lignocaine and their combination for lumber epidural analgesia in water buffalo calves (Bubalus bubalis).

The study was conducted to evaluate the effects of xylazine alone (0.05 mg/kg), lignocaine alone (2.0 mg/kg) and a combination of xylazine and lignocaine (0.05 mg/kg and 2.0 mg/kg, respectively) after lumbar epidural administration in water buffalo calves. Fifteen nondescript, male water buffalo calves of 6-8 months of age and weighing between 55 and 75 kg were randomly placed in 3 groups (A, B and C). The agents were administered at the 1st lumbar epidural space. Clinico-physiological parameters such as analgesia, ataxia, sedation, salivation, heart rate, respiratory rate and rectal temperature were studied. Other haematological and biochemical parameters monitored were haemoglobin, packed cell volume, total leukocyte count, plasma glucose, cortisol, protein albumin, globulin, blood urea nitrogen, creatinine, ALT, sodium, potassium and chloride. The onset of analgesia was faster in group C (3.0 +/- 0.44 min) compared with that of group B (4.4 +/- 0.40 min) and group A (34.0 +/- 1.86 min). Analgesia of the thorax, flank, inguinal region, hind limbs, perineum and tail was complete in group C, but mild to moderate in groups A and B. Ataxia was severe in groups B and C and mild in group A. Mild to deep sedation were produced by groups A and C animals. Longer duration and greater depth of analgesia was produced in animals in group C. Heart rate, respiratory rate and rectal temperature decreased in groups A and C. The haematological parameters decreased in all the groups. The biochemical parameters like glucose, cortisol, blood urea nitrogen, creatinine, ALT increased in all the animals. However, total proteins and albumin decreased in the 3 groups. The plasma electrolytes sodium, potassium and chloride did not show any significant change. The results of this study indicated a possible additive analgesic interaction between epidurally administered xylazine and lignocaine, without causing any marked systemic effects in water buffalo calves.

Adrenergic alpha-Agonists↗
PubMed2004

Morphological description of combined variation of distal attachments of fibulares in a foot.

An interesting case of peculiarity of the distal attachment of the three fibular muscles is reported in the left foot of a male adult cadaver of Indian origin. The fibularis brevis, just inferior to the fibular malleolus, gave off an additional slender tendon anteromedial to its main tendon. This was attached to the dorsal digital expansion of the little toe while its main tendon was inserted to the customary bone. The tendon of fibularis longus on the plantar aspect just medial to the cuboid tunnel received a prominent slip of attachment of the tendon of tibialis posterior. The fibularis tertius had two parallel-running tendons attached to the bases of the fourth metatarsal and the fourth and fifth metatarsals respectively. The combined variation of the three fibulares in a single foot has not been reported previously. The more distal attachment of the fibularis brevis in this case is a regression in evolution. Weakness of both the fibularis brevis and fibularis longus is found in pes cavovarus. The former can be used as a rotational graft in soft tissue loss of the leg.

Adult↗
PubMed2004

Imaging and morphology of the paracondylar process in a dry adult human skull: a case report.

An unusually long paracondylar process (PCP) was found articulating with the transverse atlantal process in a dry adult male skull. It was 13 mm long and 19 mm in circumference at its middle and projected to a lower plane than the styloid process of the same side. A radiograph revealed the structure of spongiosa of the PCP to be like mastoid cells. PCP can lead to clinical symptoms due to alterations in posture and functional limitations in neck movements. Thus awareness of this process, its topographical relations and its attendant problems is of importance to clinicians, radiologists, surgeons and chiropractors. In symptomatic cases surgical resection of this process can be attempted to relieve the symptoms. The craniovertebral junction constitutes a unique part of the somite-derived axial skeleton; the lowest part of the basioccipital component including this process develops from occipital sclerotomes. Developmental variations in this region can resemble deformities.

Adult↗
PubMed2004

Total number and mean size of alveoli in mammalian lung estimated using fractionator sampling and unbiased estimates of the Euler characteristic of alveolar openings.

Estimation of alveolar number in the lung has traditionally been done by assuming a geometric shape and counting alveolar profiles in single, independent sections. In this study, we used the unbiased disector principle to estimate the Euler characteristic (and thereby the number) of alveolar openings in rat lungs and rhesus monkey lung lobes and to obtain robust estimates of average alveolar volume. The estimator of total alveolar number was based on systematic, uniformly random sampling using the fractionator sampling design. The number of alveoli in the rat lung ranged from 17.3 x 10(6) to 24.6 x 10(6), with a mean of 20.1 x 10(6). The average number of alveoli in the two left lung lobes in the monkey ranged from 48.8 x 10(6) to 67.1 x 10(6) with a mean of 57.7 x 10(6). The coefficient of error due to stereological sampling was of the order of 0.06 in both rats and monkeys and the biological variation (coefficient of variance between individuals) was 0.15 in rat and 0.13 in monkey (left lobe, only). Between subdivisions (left/right in rat and cranial/caudal in monkey) there was an increase in variation, most markedly in the rat. With age (2-13 years) the alveolar volume increased 3-fold (as did parenchymal volume) in monkeys, but the alveolar number was unchanged. This study illustrates that use of the Euler characteristic and fractionator sampling is a robust and efficient, unbiased principle for the estimation of total alveolar number in the lung or in well-defined parts of it.

Age Factors↗
PubMed2004

A comparison of sonourethrography and retrograde urethrography in evaluation of anterior urethral strictures.

AIM: This prospective study was undertaken to evaluate the abnormalities of the male anterior urethra using high-resolution ultrasound (sonourethrography) and to compare the efficacy with that of retrograde urethrography (RGU) using operative findings as the gold standard. MATERIALS AND METHODS: Seventy patients with symptoms of lower urinary tract obstruction underwent RGU followed by sonourethrography. The sonologist was blinded to the findings of RGU. The parameters studied were compared with the intra-operative findings as gold standard, and the sensitivity, specificity and overall accuracy for the procedures were calculated. Chi-square test and kappa statistics were used where appropriate. RESULTS: All patients found to have urethral stricture disease by RGU were also detected by sonourethrography and confirmed intra-operatively. In the estimation of stricture length, RGU showed a lower sensitivity (60-80%) for lengths 1-4 cm, compared with sonourethrography (73.3-100%). Spongiofibrosis was detected by sonourethrography with a sensitivity of 77.3-83.3%. All the false tracts and calculi detected at sonourethrography were confirmed at surgery, whereas RGU showed a low sensitivity in their detection. The complications encountered during the procedures were pain, urethral bleeding and contrast intravasation. The frequency of pain during RGU was greater (p < 0.001); however, the difference in frequency of bleeding after the two procedures was not significant (p < 0.5). CONCLUSION: RGU and sonourethrography are equally efficacious in detection of anterior urethral strictures. Further characterization of strictures in terms of length, diameter and periurethral pathologies, like spongiofibrosis and false tracts, is done with greater sensitivity using sonourethrography as compared with RGU, with the added benefit of lower incidence of complications.

Hemorrhage↗
PubMed2004

Renal replacement therapy options from an Indian perspective: dialysis versus transplantation.

In developing countries such as India, the management of end-stage renal disease (ESRD) is largely guided by economic considerations. In the absence of health insurance plans, fewer than 10% of all patients receive renal replacement therapy (RRT). Hemodialysis (HD) is mainly a short-term measure to support ESRD patients prior to transplant. Infections are common in dialysis patients. The majority of patients starting HD die or are forced to abandon treatment because of cost constraints within the first 3 months. The cost of peritoneal dialysis (PD) is two times higher than that of HD, fewer than 2% of patients are started on PD. Among the three RRT options available, renal transplant is the preferred mode, as it is most cost-effective and provides a better quality of life. But due to financial constraints and nonavailability of organs, only about 5% of ESRD patients undergo transplant surgery. Though the removal of organs from brain-dead patients has been legalized, the concept of donation of organs from deceased donors has not received adequate social sanction. Only 2% of all transplants are performed from deceased donors. Due to limited access to RRT, the ideal approach should be to reduce the incidence of ESRD and attempt preventive measures. Preemptive transplant, reducing the duration of dialysis prior to transplant, use of immunosuppression for only up to 1 year, and availability of more deceased donor organs may be helpful to make RRT options within the reach of the common man.

Humans↗
PubMed2004

Radiation-induced brain disorders in patients with pituitary tumours.

Radiation-induced brain disorders (RIBD) are uncommon and they are grave sequelae of conventional radiotherapy. In the present report, we describe the clinical spectrum of RIBD in 11 patients who received post-surgery conventional megavoltage irradiation for residual pituitary tumours. Of these 11 patients (nine men, two women), seven had been treated for non-functioning pituitary tumours and four for somatotropinomas. At the time of irradiation the age of these patients ranged from 30 to 59 years (mean, 39.4 +/- 8.3; median, 36) with a follow-up period of 6-96 months (mean, 18.3 +/- 26.4; median, 11). The dose of radiation ranged from 45 to 90 Gy (mean, 51.3 +/- 13.4; median, 45), which was given in 15-30 fractions (mean, 18.6 +/- 5.0; median, 15) with 2.8 +/- 0.3 Gy (median, 3) per fraction. The biological effective dose calculated for late complications in these patients ranged from 78.7 to 180 Gy (mean, 99.1 +/- 27.5; median, 90). The lag time between tumour irradiation and the onset of symptoms ranged from 6 to 168 months (mean, 46.3 +/- 57.0; median, 57). The clinical spectrum of RIBD included new-onset visual abnormalities in five, cerebral radionecrosis in the form of altered sensorium in four, generalized seizures in four, cognitive dysfunction in five, dementia in three and motor deficits in two patients. Magnetic resonance imaging (MRI)/CT of the brain was suggestive of radionecrosis in eight, cerebral oedema in three, cerebral atrophy in two and second neoplasia in one patient. Associated hormone deficiencies at presentation were hypogonadism in eight, hypoadrenalism in six, hypothyroidism in four and diabetes insipidus in one patient. Autopsy in two patients showed primitive neuroectodermal tumour (PNET) and brainstem radionecrosis in one, and a cystic lesion in the left frontal lobe following radionecrosis in the other. We conclude that RIBD have distinctive but varying clinical and radiological presentations. Diabetes insipidus and PNET as a second neoplastic disorder in adults following pituitary irradiation have not been reported previously.

Adenoma↗
PubMed2004

Keratoconus in Asian eyes at a tertiary eye care facility.

BACKGROUND: The purpose of this study was to assess the demographic variables, age at diagnosis, keratometry and slitlamp signs in keratoconus. METHODS: Thirty-one patients with 61 keratoconic eyes were selected provided they met one of two criteria: 1. They had an irregular corneal surface, Vogt's striae, Fleischer's ring or apical sub-epithelial corneal scarring characteristic of keratoconus; 2. Corneal topography revealed an average simulated keratometry of more than 45.2 D, central corneal power higher than 47.2 D or infero-superior asymmetry greater than 1.4 D. The main outcome measures were demographic variables, age at diagnosis, disease severity on keratometry and biomicroscopic signs. RESULTS: The patients' mean age at presentation was 20.2 +/- 6.4 years. Based on average keratometry values, 67.2 per cent of eyes had severe and 32.8 per cent had moderate keratoconus. Eyes with severe keratoconus presented at a younger average age (18.8 +/- 5.35 years) than moderate keratoconus (23.69 +/- 8.07 years). Thirty-eight eyes (92.5 per cent) with severe and 13 eyes (65 per cent) with moderate keratoconus demonstrated biomicroscopic signs of keratoconus. Twenty eyes (32.7 per cent) demonstrated apical sub-epithelial cornea scarring and 95 per cent of these eyes had severe keratoconus. CONCLUSIONS: The majority of keratoconic eyes in Asian-Indian patients demonstrate the severe stage of the disease by the second decade.

Adolescent↗
PubMed2004

Presentation and outcome of rhino-orbital-cerebral mucormycosis in patients with diabetes.

AIM: To report presentation and outcome of rhino-orbital-cerebral mucormycosis (ROCM) exclusively in patients with diabetes mellitus. METHODS: Retrospective, non-comparative, interventional analysis of the medical records of 35 patients with ROCM among 22 316 patients with diabetes seen over the last 12 years. RESULTS: A cohort of 23 men and 12 women with a mean (SD) age of 47.3 (14.4) years (range 18-70 years) was studied. Five patients had type 1 diabetes mellitus, 29 had type 2 diabetes mellitus, and one had secondary diabetes. Nine patients had ROCM as the first clinical manifestation of diabetes. The mean (SD) blood glucose at presentation was 20.6 (8.3) mmol/l (range 10.0 to 53.3 mmol/l) and 17 patients had ketosis/ketoacidosis. Ophthalmic symptoms and signs were pronounced: external ophthalmoplegia (89%), proptosis (83%), visual loss (80%), chemosis (74%), and eye lid gangrene (14%). Non-ophthalmic manifestations included sinusitis (100%), nasal discharge/ulceration (74%), infranuclear VI nerve palsy (46%), palatal necrosis (29%), cerebral lobe involvement (20%), and hemiparesis (17%). Computed tomography/magnetic resonance imaging showed involvement of paranasal sinuses in all patients with ethmoid (86%) and maxillary (80%) sinuses being most frequently involved. Orbital involvement was observed in 80% of patients with cavernous sinus thrombosis in 11%, and internal carotid occlusion and hydrocephalus in 3% each. All were treated with amphotericin B (3-3.5 g) and 26 (74%) patients underwent appropriate surgery. Twenty one patients (68%) survived with a mean (SD) follow up of 39.6 (34.1) months (range 10 months to 11 years). Factors related to poor survival included delay in diagnosis and treatment (p<0.05), facial and/or eye lid gangrene (p<0.05), hemiplegia (p<0.05), cerebral invasion by mucorales (p<0.05), and treatment with amphotericin B alone (p<0.05). CONCLUSIONS: In patients with diabetes and ROCM, ROCM was the presenting manifestation in one fourth of the patients. Ophthalmic and extensive cerebral involvement predominated in the clinical picture. Delay in treatment due to late presentation and associated complications were major determinants of the survival outcome in these patients.

Adolescent↗