Biomedical subjects
Publications and source records attributed to A P Singh.
Haemangioma is a common benign soft tissue tumour. Intramuscular haemangiomas are rare but pose quite a diagnostic challenge. An intramuscular haemangioma can be confused with other soft tissue swellings including abscess. We present a case report of swelling around the knee in an adolescent patient, which was ultimately diagnosed and treated as intramuscular haemangioma of the quadriceps muscle.
MUC4 mucin is a high molecular weight transmembrane glycoprotein that plays important roles in tumour biology. It is aberrantly expressed in pancreatic adenocarcinoma, while not being detectable in the normal pancreas. Previous studies have demonstrated that the cystic fibrosis transmembrane conductance regulator (CFTR), a chloride channel that is defective in CF, is implicated in multiple cellular functions, including gene regulation. In the present study, using a CFTR-defective pancreatic cancer cell line and its derived subline expressing functional CFTR, we report that MUC4 expression is negatively regulated by CFTR. Short-interfering RNA (siRNA)-mediated silencing of CFTR also leads to an increased expression of MUC4. Additionally, our results suggest that CFTR-mediated regulation of MUC4 is cell density-dependent and is achieved by transcriptional and posttranslational mechanisms. Moreover, in a panel of pancreatic cancer cell lines and normal pancreas, we observed that CFTR was downregulated in pancreatic cancer cells and negatively correlated with MUC4 in most cases. An aberrant expression of MUC4 was also detected in the CF pancreas. Downregulation of CFTR in pancreatic adenocarcinoma and its inverse association with the tumour-linked mucin, MUC4, indicate novel function(s) of CFTR in pancreatic tumour biology and suggest the implication of new signalling pathway(s) in MUC4 regulation.
BACKGROUND: General anesthesia (GA) is the standard anesthesia for patients undergoing modified radical mastectomy (MRM) for breast cancer. Cervical epidural anesthesia (CEA) is practiced less often because of its reported complications. This prospective study aimed to evaluate the safety and efficacy of CEA as an anesthetic technique for MRM. PATIENTS AND METHODS: Fifty breast cancer patients with ASA (American Society of Anesthesiologists) grade I or II underwent MRM under CEA from September 2004 to January 2006. Anesthesia was induced with 10 ml of 1% lignocaine; adrenaline was administered through an 18-gauge catheter in C(6)-C(7) or C(7)-T(1) epidural space. Postoperative analgesia was maintained with 0.125% bupivacaine through the epidural catheter. RESULTS: In 49 (98%) patients surgery was conducted smoothly under CEA with good analgesia. 44 patients were awake during surgery. Five patients had to be given intravenous sedation with midazolam, and in one case the procedure was terminated after accidental dura puncture. There were no clinically significant variations in perioperative pulse and respiratory rate, and there was no fall in mean arterial blood pressure during the procedure. The mean preoperative anesthesia time and total cost of the procedure was 20.36 + 2.75 minutes and 12.19 + 2.2 pound, respectively. All patients were started on a liquid diet and mobilized 4 hours after surgery. CONCLUSIONS: Cervical epidural anesthesia is a safe alternative to GA and was preferred by our patients because of its lower cost and reduced perioperative morbidity.
BACKGROUNDS AND AIMS: Information on the micro-distribution of lignin within the middle lamella is only just beginning to emerge. This paper provides evidence of marked heterogeneity in the micro-distribution of lignin, pectin, peroxidase and hydrogen peroxide in the middle lamella of alfalfa (Medicago sativa). METHODS: Specimens from alfalfa stems were collected and processed for transmission electron microscopy. The middle lamella architecture was examined prior to and during lignification, using transmission electron microscopy in combination with pectin- and lignin-specific staining. In addition, immuno-gold labelling of peroxidase and cytochemical localization of hydrogen peroxide (H2O2) were undertaken. KEY RESULTS: Lignin showed inhomogeneity in its distribution in the middle lamella. It was found that the distribution of pectin was irregular and corresponded to the pattern of deposited lignin. Additionally, a similarity in the pattern of the deposited lignin to the pattern of distribution of peroxidase and H2O2 was also observed. CONCLUSIONS: Irregular distribution of pectin in the middle lamella may be related to subsequent inhomegeneity in lignin in this region.
NALCO--the largest exporter of aluminium in India has a power plant of 720 MW capacity in Nandira watershed in Angul district of Orissa. The power plant utilises local coal to generate thermal power and disposes of large amount of ash which accumulates in slurry form at nearby two ash ponds. These ash ponds were breached on 31 December 2000, causing ash accumulation for entire regime of the Nandira river. An attempt has been made towards preparation of recovery and rehabilitation plan for NALCO using temporal Remote Sensing data and GIS. Indian remote sensing satellite data for pre-breach condition 12 December 2000, during breach event 31 December 2000 and post-breach condition 4 and 6 January 2001 has been digitally analysed for Nandira watershed. The satellite data of coarse spatial resolution provides the absence and presence of fresh sediment deposition along Nandira watershed and Brahmani river pertaining to pre-breach and post-breach conditions respectively on regional scales. The temporal comparison of fine resolution has clearly highlighted the aerial extent of damage caused by the disaster for entire watershed on local scales. The GIS has helped in demarcation of freshly accumulated ash at interval of 500 m along the river length as well as in delineation of maximum ash accumulation across the river width. The study has clearly demonstrated the use of temporal Remote Sensing data in conjunction with GIS for disaster management in terms of recovery and rehabilitation plan preparation of the Nandira watershed.
Spinal muscular atrophies (SMA) are clinically heterogenous group of motor system disorders characterised by progressive pure lower motor neuron involvement. The distal form of SMA is an extremely rare disorder, which presents in the adults and has a relatively slow progression with almost no effect on the patients' life-span. Differential diagnosis of this syndrome include other forms of neuromuscular disorders with peroneal muscular atrophy like hereditary motor sensory neuropathy (HMSN) and distal myopathies, which need exclusion before confirming this rare entity. We present a young male with this disorder and briefly discuss the theoretical aspects.
Mobile elements are most abundant in the mammalian genome, comprising at least 40-50% of the DNA. They are differentiated into two most prominent families: the LINE elements, which are preferentially located in the G-bands, and SINES, which are clustered in the R-bands. We report here a novel mammalian non-L1-retroposon, which invaded the genome of Microtus agrestis in a very short time from an evolutionary viewpoint. No relevant sequence homology could be demonstrated to known sequences in the NCBI database. However, cross-hybridizing sequences exist in the genomes of all other Microtus species analyzed, but not in Mus musculus, indicating the recent evolutionary origin of this element. This retroposon is enriched in the entire heterochromatin of the X and Y chromosomes, but is also interspersed in autosomal locations in euchromatic portions of the genome. We show that the retroposon is heavily transcribed from the heterochromatin during female meiosis prerequisite for the subsequent retrotransposition. The estimated rate of retrotransposition is at least 1-2 x 10(-2) per generation, which is hundred-fold higher than that of the majority of invertebrate retroposons and also higher than the transposition rate of a murine L1 element, which was calculated to be 3 x 10(-3) per generation.
Granulomatous angiitis of central nervous system (CNS) is a rare inflammatory disease of blood vessels mostly confined to CNS. We describe a case which presented with right sided hemiplegia with aphasia, after herpes zoster ophthalmicus. CT scan and MRI brain showed a large left sided infarct in the left middle cerebral artery (MCA) territory. MRI angiography revealed narrowing and thinning of left internal carotid artery (ICA) and to a lesser extent, left MCA suggestive of granulomatous vasculitis. Herpes zoster is often associated with major CNS involvement and a vascular etiology was previously postulated. Recent pathological reports suggest that cerebral angiitis secondary to herpes virus infection may be more common than realised.
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Atypical laterality (i.e. the lack of a clear pattern of lateralization) has been found to be a characteristic feature of individuals with intellectual disability (ID). The evidence for this has been based on 'handedness' studies which have contained little information about the ability of people with ID to carry out interhemispheric tasks reflecting bilateral transfer or interference. The present study examined this capacity in individuals with ID by utilizing bilateral transfer and interference paradigms. Right-handed subjects with ID (IQ = 55-76) and controls matched for age and sex were tested for bilateral transfer of motor skill in contralateral hands with a mirror-drawing task. The subjects were also tested for their ability to perform a finger-tapping task while processing verbal and non-verbal stimuli. The findings indicated that people with ID are significantly deficient relative to matched controls in bilateral transfer of motor skills from their non-preferred (left) hand to their preferred (right) one. The effect of interference during performance of the dual task was significantly greater in individuals with ID. Subjects with ID were found to perform better with their non-preferred than with their preferred hand. A within-group comparison revealed that right-handed performance was more affected by interference than left in these subjects.
A 55 year old man presented with features of cauda equina syndrome. Magnetic resonance imaging (MRI) showed a well demarcated intradural extramedullary tumour at L2 vertebra. At surgery it was found to be well encapsulated and had no attachment to spinal cord or root. Histopathology including immunohistochemistry confirmed it to be a low grade astrocytoma.
Generalizing the mode-coupling theory for ideal liquid-glass transitions, equations of motion are derived for the correlation functions describing the glassy dynamics of a diatomic probe molecule immersed in a simple glass-forming system. The molecule is described in the interaction-site representation and the equations are solved for a dumbbell molecule consisting of two fused hard spheres in a hard-sphere system. The results for the molecule's arrested position in the glass state and the reorientational correlators for angular-momentum index l=1 and l=2 near the glass transition are compared with those obtained previously within a theory based on a tensor-density description of the molecule in order to demonstrate that the two approaches yield equivalent results. For strongly hindered reorientational motion, the dipole-relaxation spectra for the alpha process can be mapped on the dielectric-loss spectra of glycerol if a rescaling is performed according to a suggestion by Dixon et al. [Phys. Rev. Lett. 65, 1108 (1990)]. It is demonstrated that the glassy dynamics is independent of the molecule's inertia parameters.
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Within the mode-coupling theory (MCT) for the evolution of structural relaxation in glass-forming liquids, correlation functions and susceptibility spectra are calculated characterizing the rotational dynamics of a top-down symmetric dumbbell molecule, consisting of two fused hard spheres immersed in a hard-sphere system. It is found that for sufficiently large dumbbell elongations, the dynamics of the probe molecule follows the same universal glass-transition scenario as known from the MCT results of simple liquids. The alpha-relaxation process of the angular-index j=1 response is stronger, slower, and less stretched than the one for j=2, in qualitative agreement with results found by dielectric-loss and depolarized-light-scattering spectroscopy for some supercooled liquids. For sufficiently small elongations, the reorientational relaxation occurs via large-angle flips, and the standard scenario for the glass-transition dynamics is modified for odd-j responses due to precursor phenomena of a nearby type-A MCT transition. In this case, a major part of the relaxation outside the transient regime is described qualitatively by the beta-relaxation scaling laws, while the alpha-relaxation scaling law is strongly disturbed.
Histopathologically and immunologically confirmed case of paraganglioma of cauda equina region is described.
OBJECTIVE: To study the significance of new onset seizure in patient with human immunodeficiency virus (HIV) infection. METHODS: Patients infected with HIV with the new onset seizure were enrolled in the study. Seizure type was classified. Adequate work up was done to search for a cause of their initial seizure. All patients were administered antiepileptic drugs in addition those detected to have treatable opportunistic infection were treated for the same. RESULTS: A total of 455 patients of HIV infection were admitted to this centre during study period, of these twenty three patients had new onset seizures. Seizures were generalized tonic-clonic in fifteen patients (65.21%), partial motor in six patients (26.08%) and partial motor with secondary generalization in two patients (8.69%). Recurrence of seizures was observed in 69.56% patients. Identified causes included cerebral toxoplasmosis in seven patients (30.43%), cryptococcal meningitis in four (17.39%), tuberculoma in three (13.04%), AIDS dementia complex in one (4.34%) and progressive multifocal leucoencephalopathy in one (4.34%). In seven patients (30.43%) seizures were not associated with any identifiable cause. Phenytoin was used for control of seizures and no side effects to the drug were noted during the brief period of follow up. CONCLUSION: Majority of patients with HIV infection and new onset seizures have secondary brain lesion as the cause of seizure. High rate of seizure recurrence mandates therapy of solitary seizure in patients with HIV infection.
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