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Biomedical subjects

Arun Gupta

Publications and source records attributed to Arun Gupta.

At least 19 recordsLinked to original sources

MR demonstration of complete cerebellar and corpus callosum agenesis.

Complete cerebellar agenesis is a very rare entity, which occurs during the early period of embryogenesis and is usually associated with severe motor dysfunction. We report a case of complete cerebellar agenesis with complete corpus callosum agenesis diagnosed on magnetic resonance imaging (MRI). These anomalies were also associated with rudimentary pons.

Agenesis of Corpus Callosum↗

Reader error during CT colonography: causes and implications for training.

This study investigated the variability in baseline computed tomography colonography (CTC) performance using untrained readers by documenting sources of error to guide future training requirements. Twenty CTC endoscopically validated data sets containing 32 polyps were consensus read by three unblinded radiologists experienced in CTC, creating a reference standard. Six readers without prior CTC training [four residents and two board-certified subspecialty gastrointestinal (GI) radiologists] read the 20 cases. Readers drew a region of interest (ROI) around every area they considered a potential colonic lesion, even if subsequently dismissed, before creating a final report. Using this final report, reader ROIs were classified as true positive detections, true negatives correctly dismissed, true detections incorrectly dismissed (i.e., classification error), or perceptual errors. Detection of polyps 1-5 mm, 6-9 mm, and > or =10 mm ranged from 7.1% to 28.6%, 16.7% to 41.7%, and 16.7% to 83.3%, respectively. There was no significant difference between polyp detection or false positives for the GI radiologists compared with residents (p=0.67, p=0.4 respectively). Most missed polyps were due to failure of detection rather than characterization (range 82-95%). Untrained reader performance is variable but generally poor. Most missed polyps are due perceptual error rather than characterization, suggesting basic training should focus heavily on lesion detection.

Clinical Competence↗

Atypical antipsychotic-induced akathisia with depression: therapeutic role of mirtazapine.

OBJECTIVE: To investigate the efficacy of mirtazapine in treating akathisia caused by risperidone and olanzapine, as well as its use in alleviating comorbid depressive disorder. CASE SUMMARIES: Five patients with diagnoses varying from schizophrenia, delusional disorder, and bipolar disorder developed akathisia while on treatment with olanzapine and risperidone. The likelihood that risperidone and olanzapine had induced akathisia in all patients was rated probable according to the Naranjo probability scale. Four of these patients were also found to be depressed. The akathisia was successfully treated with mirtazapine, and 3 of the 4 depressed patients improved with mirtazapine treatment. Use of mirtazapine did not result in any adverse effect. DISCUSSION: Mirtazapine is a potent antagonist of central alpha(2) auto- and hetero-adrenergic receptors, as well as an antagonist of 5-HT(2A/2C), 5-HT(3), and histaminergic H(1) postsynaptic receptors. The efficacy of mirtazapine in treatment of akathisia may result from its antagonist property at the H(1) receptors and its dopaminergic activity in frontal cortex. The use of mirtazapine offers advantages over other anti-akathisia drugs in its better adverse effect profile, as well as its ability to treat coexisting depression. CONCLUSIONS: Mirtazapine is efficacious in treating atypical antipsychotic-induced akathisia. It may be a good option, particularly in patients with coexisting depression.

Adult↗

Mammalian Rad9 plays a role in telomere stability, S- and G2-phase-specific cell survival, and homologous recombinational repair.

The protein products of several rad checkpoint genes of Schizosaccharomyces pombe (rad1+, rad3+, rad9+, rad17+, rad26+, and hus1+) play crucial roles in sensing changes in DNA structure, and several function in the maintenance of telomeres. When the mammalian homologue of S. pombe Rad9 was inactivated, increases in chromosome end-to-end associations and frequency of telomere loss were observed. This telomere instability correlated with enhanced S- and G2-phase-specific cell killing, delayed kinetics of gamma-H2AX focus appearance and disappearance, and reduced chromosomal repair after ionizing radiation (IR) exposure, suggesting that Rad9 plays a role in cell cycle phase-specific DNA damage repair. Furthermore, mammalian Rad9 interacted with Rad51, and inactivation of mammalian Rad9 also resulted in decreased homologous recombinational (HR) repair, which occurs predominantly in the S and G2 phases of the cell cycle. Together, these findings provide evidence of roles for mammalian Rad9 in telomere stability and HR repair as a mechanism for promoting cell survival after IR exposure.

Animals↗

Incidence of periventricular leucomalacia among a cohort of very low birth weight neonates(< 1500 g).

BACKGROUND: Periventricular leucomalacia (PVL) is the most important neuropathologic lesion underlying major neuro-motor deficits of pre-term very low birth weight (VLBW) infants. Published data regarding PVL is not available from our country. OBJECTIVES: A study was planned with main objectives to estimate incidence and describe natural history of PVL among a very low birth weight cohort. STUDY DESIGN: A cohort study was performed on inborn VLBW babies over one year period at a tertiary neonatal intensive care unit. Serial weekly cranial ultrasounds were performed on 97 enrolled subjects until discharge, to diagnose and describe natural history of PVL. RESULTS: 31 out of 97 enrolled subjects developed PVL. No case of PVL developed beyond 19 days of postnatal life. Serial ultrasounds for each baby were tracked until discharge or death. Majority of lesions at onset were flares. Cysts tended to develop in over one third of cases during course of hospital stay. About 50% of ultrasound had normalized at discharge and sequelae such as cerebral atrophy and ventriculomegaly had appeared in few, the rest of lesions being either flares or cysts of PVL. CONCLUSIONS: PVL is fairly common among very low birth weight neonates. Ultrasonographic lesions of PVL undergo dynamic evolution from time of first detection to either progress, regress or leave sequelae before discharge. Ultrasound remains an important bedside diagnostic tool for PVL.

Disease Progression↗

Monitoring of head injured patients.

PURPOSE OF REVIEW: This article reviews recent advances in multimodality monitoring of patients following severe head injury during the period of 2004-2005. RECENT FINDINGS: Whilst intracranial pressure measurement remains the cornerstone of neuromonitoring, analysis of the intracranial pressure waveform provides additional information, which may help guide treatment and predict outcome. Non-invasive detection of intracranial hypertension and assessment of cerebral perfusion pressure and autoregulation is the focus of ongoing research. Although jugular venous saturation monitoring remains a useful method for detecting global hypoperfusion its sensitivity to regional ischaemia is low. Brain tissue oxygen monitoring overcomes this deficiency and sheds new light on the pathophysiology of cerebral ischaemia following brain injury. Further studies are required to define ischaemic thresholds and their association with outcome. Extracellular brain pH has been recently linked to outcome and further studies are required to establish the role of pH regulation. Monitoring of brain metabolism using a cerebral microdialysis continues to develop its niche in clinical neuromonitoring, although it currently remains a research tool. SUMMARY: Multimodality neuromonitoring plays an important role in managing patients with severe head injury. It helps guide treatment, provides prognostic information and explores the pathophysiology of evolving brain injury.

Journal Article↗

High pre-transplant soluble CD30 levels are predictive of the grade of rejection.

In renal transplantation, serum soluble CD30 (sCD30) levels in graft recipients are associated with increased rejection and graft loss. We investigated whether pre-transplant sCD30 concentrations are predictive of the grade of rejection. Pre-transplant sera of 51 patients with tubulointerstitial rejection (TIR), 16 patients with vascular rejection (VR) and an age-matched control group of 41 patients with no rejection (NR) were analyzed for sCD30. The transplant biopsies were immunostained for C4d. The median sCD30 level was significantly elevated in the group with VR (248 Units (U)/mL, range: 92-802) when compared with TIR (103 U/mL, range: 36-309, p<0.001) and NR (179 U/mL, range: 70-343, p<0.03). Moreover, patients with TIR had significantly lower sCD30 levels compared to NR. Based on C4d staining, a TH2 driven process, the median sCD30 levels were significantly raised in C4d+ patients compared with C4d- group (177 U/mL vs. 120 U/mL, p<0.05). sCD30 levels measured at time of transplantation correlate with the grade of rejection. High pre-transplant levels are associated with antibody-mediated rejection which carries a poorer prognosis. sCD30 could be another tool to assess immunological risk prior to transplantation and enable a patient centered approach to immunosuppression.

Adult↗

Involvement of human MOF in ATM function.

We have determined that hMOF, the human ortholog of the Drosophila MOF gene (males absent on the first), encoding a protein with histone acetyltransferase activity, interacts with the ATM (ataxia-telangiectasia-mutated) protein. Cellular exposure to ionizing radiation (IR) enhances hMOF-dependent acetylation of its target substrate, lysine 16 (K16) of histone H4 independently of ATM function. Blocking the IR-induced increase in acetylation of histone H4 at K16, either by the expression of a dominant negative mutant DeltahMOF or by RNA interference-mediated hMOF knockdown, resulted in decreased ATM autophosphorylation, ATM kinase activity, and the phosphorylation of downstream effectors of ATM and DNA repair while increasing cell killing. In addition, decreased hMOF activity was associated with loss of the cell cycle checkpoint response to DNA double-strand breaks. The overexpression of wild-type hMOF yielded the opposite results, i.e., a modest increase in cell survival and enhanced DNA repair after IR exposure. These results suggest that hMOF influences the function of ATM.

Acetyltransferases↗

True tail in a neonate.

Distinction between true and pseudo trail in lumbo-sacral region is important since treatment and prognosis are different. Fewer than 40 cases have been reported in literature. The authors report a case of true tail in a neonate, a rare event.

Humans↗

Neonatal lower extremity gangrene.

Four neonates suffering from bilateral lower limb gangrene were referred to us for further management. Two neonates had no contributory etiology. All four received appropriate treatment thus avoiding mortality but morbidity could not be avoided. All four neonates recovered uneventfully.

Female↗

Tuberculous gastric perforation: report of a case.

A 21-year-old woman presented with a 2-day history of acute abdominal pain. Contrast-enhanced computed tomography (CT) showed a perforation in the lesser curve of the stomach. The patient suffered a bout of hematemesis, following which an endoscopy showed a bleeding blood vessel at the edge of the perforation. We performed an emergency distal gastrectomy, including the ulcer site. Histopathological examination revealed tuberculous granulation tissue and acid-fast bacilli in the ulcer. The patient was given antituberculosis therapy (ATT) postoperatively, and was well when last seen 1 year 5 months after surgery. We analyzed the clinical data of five cases of tuberculous gastric perforation (TGP), reported between 1948 and 2003, including our patient. The patients ranged in age from 21 to 45 years, with a mean age of 36.8 years (SD +/- 10.21), and a male to female ratio of 3 : 2. The diagnosis was confirmed by surgery or autopsy. Abdominal lymphadenopathy was present in all patients. Gastrectomy was performed in four patients, and two were given ATT. All four patients in the previous reports died of their disease.

Abdominal Pain↗

Primary leiomyosarcoma of the seminal vesicle.

A case of leiomyosarcoma of the seminal vesicle detected as a prerectal mass on routine per-rectal examination is described in a 37-year-old man. Computed tomography scan confirmed it to be arising from the right seminal vesicle. Per-rectal trucut biopsy showed malignant cells. Radical cystoprostatectomy with bilateral pelvic lymphadenectomy with anterior resection of rectum and urinary diversion with ileal conduit was performed. Microscopic examination of the resected specimen showed moderately differentiated leiomyosarcoma from the seminal vesicle. The patient received adjuvant chemotherapy and sandwiched radiotherapy. He is well and free of tumor 20 months after surgery.

Adult↗

Genomic instability and enhanced radiosensitivity in Hsp70.1- and Hsp70.3-deficient mice.

Heat shock proteins (HSPs) are highly conserved among all organisms from prokaryotes to eukaryotes. In mice, the HSP genes Hsp70.1 and Hsp70.3 are induced by both endogenous and exogenous stressors, such as heat and toxicants. In order to determine whether such proteins specifically influence genomic instability, mice deficient for Hsp70.1 and Hsp70.3 (Hsp70.1/3(-/-) mice) were generated by gene targeting. Mouse embryonic fibroblasts (MEFs) prepared from Hsp70.1/3(-/-) mice did not synthesize Hsp70.1 or Hsp70.3 after heat-induced stress. While the Hsp70.1/3(-/-) mutant mice were fertile, their cells displayed genomic instability that was enhanced by heat treatment. Cells from Hsp70.1/3(-/-) mice also display a higher frequency of chromosome end-to-end associations than do control Hsp70.1/3(+/+) cells. To determine whether observed genomic instability was related to defective chromosome repair, Hsp70.1/3(-/-) and Hsp70.1/3(+/+) fibroblasts were treated with ionizing radiation (IR) alone or heat and IR. Exposure to IR led to more residual chromosome aberrations, radioresistant DNA synthesis (a hallmark of genomic instability), increased cell killing, and enhanced IR-induced oncogenic transformation in Hsp70.1/3(-/-) cells. Heat treatment prior to IR exposure enhanced cell killing, S-phase-specific chromosome damage, and the frequency of transformants in Hsp70.1/3(-/-) cells in comparison to Hsp70.1/3(+/+) cells. Both in vivo and in vitro studies demonstrate for the first time that Hsp70.1 and Hsp70.3 have an essential role in maintaining genomic stability under stress conditions.

Animals↗