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R Bhargava

Publications and source records attributed to R Bhargava.

At least 19 recordsLinked to original sources
PubMed2006

Comparison of a dipstick dot-ELISA with commercial assays for anti-dengue virus IgM antibodies.

Dengue virus infections have undergone dramatic expansion in range, affecting several tropical and subtropical regions of the world. Dengue virus causes life-threatening complications characterized by dengue hemorrhagic fever and dengue shock syndrome. No standard validated test systems are available for serological diagnosis of dengue virus infection. This creates problems in the diagnosis and proper management of patients. Evaluation of a Defense Research and Development Establishment (DRDE) dengue virus dipstick dot-ELISA test, developed in house, vis-à-vis commercially available immunodiagnostic kits was carried out for detection of IgM antibodies. The DRDE dengue dipstick dot-ELISA was performed on the basis of the dot-ELISA principle. Commercial tests, namely, the Panbio Dengue IgM Capture ELISA system (Panbio, Sinnamon Park, Australia) and Pathozyme Dengue M (Omega Diagnostics, Alva, UK), were performed according to the manufacturers' protocols. Ninety-one serum samples collected from the states of Kerala and Delhi, India during August and November of 2004 were used in the present study. The overall agreement among all three tests was found to be only 72.16% for IgM antibodies. Correlations between the DRDE dipstick dot-ELISA and the Panbio kit, between the DRDE dipstick dot-ELISA and the Pathozyme Dengue M kit, and between the Panbio kit and the Pathozyme Dengue M kit were found to be 96, 93, and 94%, respectively. Although the Panbio kit is widely used in various laboratories in India, the DRDE dipstick dot-ELISA promises to be a useful kit because of its field applicability and comparable sensitivity.

Animals↗
PubMed2005

Autosomal dominant inheritance of spondyloenchondrodysplasia.

Spondyloenchondrodysplasia comprises generalized enchondromatosis with platyspondyly and is thought to be inherited as an autosomal recessive condition. A mother and son are reported with typical features of spondyloenchondrodysplasia. Their similar radiographic and MRI findings are presented. The radiologic appearance of the spine changed over time, illustrating the evolving phenotype of this condition. Transmission from mother to son suggests that dominant pattern of inheritance is possible. A classification of the enchondromatoses is discussed.

Adult↗
PubMed2004

Using magnetic resonance imaging to characterize pedicle asymmetry in both normal patients and patients with adolescent idiopathic scoliosis.

STUDY DESIGN: Morphometric analysis of vertebrae from normal patients and patients with adolescent idiopathic scoliosis. OBJECTIVES: To use magnetic resonance imaging to assess pedicle asymmetry in normal patients and patients with adolescent idiopathic scoliosis in the early stages of scoliosis development and to determine if patients with adolescent idiopathic scoliosis exhibited a consistent vertebral morphology. SUMMARY OF BACKGROUND DATA: To date, most studies of vertebral morphology in adolescent idiopathic scoliosis have produced conflicting data, especially on pedicle length, and have been conducted on patients in the late stages of scoliosis development, which may affect the patterns of vertebral morphology detected. Magnetic resonance imaging enables in vivo assessment of curves during development and permits improved acquisition of transverse images. METHODS: Magnetic resonance images of 76 pedicles from 8 normal patients and 80 pedicles from 10 patients with adolescent idiopathic scoliosis were examined retrospectively. Recorded parameters included pedicle lengths, pedicle widths, pedicle areas, pedicle perimeters, and lamina lengths. The extent and direction of asymmetry in vertebrae from normal patients and patients with adolescent idiopathic scoliosis were determined and compared. RESULTS: Normal patients displayed significant neural arch asymmetry, with the left sided measurements being greater. Patients with adolescent idiopathic scoliosis also displayed significant neural arch asymmetry; however, the longer pedicle was not consistently on the convexity or the concavity. CONCLUSIONS: The baseline used to assess adolescent idiopathic scoliosis vertebral morphology must take into consideration the extent and direction of normal vertebral asymmetry. The pattern of vertebral asymmetry seen inadolescent idiopathic scoliosis may depend on the specific cause of the disorder, with no consistent pattern evident when data from different causes are pooled together.

Adolescent↗
PubMed2003

Reversible posterior leukoencephalopathy syndrome in a child with cerebral X-linked adrenoleukodystrophy treated with cyclosporine after bone marrow transplantation.

Reversible posterior leukoencephalopathy syndrome (RPLS) was described by Hinchey and colleagues in 1996. The disorder occurs predominantly in patients with acute hypertension and/or on pharmacological immunosuppression. We report a 6-year-old male with cerebral X-linked adrenoleukodystrophy who received an HLA-matched unrelated bone marrow transplant (BMT). Cyclosporine was used as graft-versus-host disease prophylaxis. At 55 days post-BMT, his cyclosporine concentrations were high for several days and the concentration was still high on day 70 (353 microg/L). He presented 83 days post-BMT with new onset of headache, lethargy, acute visual loss and focal seizures. He was not hypertensive. MRI of the head revealed signal changes that now extended more peripherally into the subcortical and cortical regions of the occipital and temporal lobes. The patient's cyclosporine was stopped for 5 days. The patient's vision returned to normal and his headaches and lethargy resolved with no further seizures 3 weeks later. Follow-up MRI of the head 2 months later showed almost complete resolution of the cortical signal abnormalities. It is important to consider RPLS in patients with cerebral adrenoleukodystrophy who present with acute neurological deterioration. Attention to the pattern of white matter and the presence of cortical grey matter involvement on neuroimaging is important for the diagnosis. When appropriate management is initiated, that is controlling hypertension when present and discontinuing or reducing the dose of offending immunosuppressive agents, the acute neurological symptoms will usually resolve.

Adrenoleukodystrophy↗
PubMed2003

Pediatric temporal lobectomy for epilepsy.

BACKGROUND: Temporal lobectomy in adults is an accepted form of treatment for patients with intractable complex partial seizures. There have been few long-term studies of children undergoing temporal lobectomy for epilepsy. METHODS: We reviewed the pediatric cases of temporal lobectomy for intractable epilepsy performed by the Comprehensive Epilepsy Program at the University of Alberta Hospitals between 1988 and 2000. All patients had preoperative and postoperative clinical evaluations, seizure charts, drug levels, EEG, CT/MRI, long-term video EEG monitoring and neuropsychological testing. The patients were reassessed at 6 weeks, 6 months and 1 year postoperatively, then yearly. The duration of follow up was 1-10 years (mean 5 years). RESULTS: Forty-two patients were studied (25 males and 17 females). Age at surgery ranged from 18 months to 16 years. The interictal EEG was abnormal in 38 of the 42 patients. Twenty-two patients had focal epileptic discharge and 1 had generalized epileptic discharge. Focal slowing was seen in 9 patients and diffuse slowing in 5 patients. CT scan was abnormal in 17 of 39 patients and normal in 22 of 39. MRI was abnormal in 34 of 42 patients and normal in 8 of 42. Pathology included brain tumors in 14 patients, mesial temporal sclerosis in 8, focal cortical dysplasia in 4, tuberous sclerosis in 4, dual pathology in 4, porencephalic cyst in 1 and normal pathology or gliosis in 6. Thirty-three of 42 patients (78%) were seizure-free following surgery and an additional 5 (12%) had a decrease in seizure frequency. Three patients had complications, but there were no deaths. CONCLUSION: Temporal lobectomy is a safe and effective treatment for children with intractable complex partial seizures. Seventy-eight percent of patients are seizure-free following the surgery and there are few complications. MRI is superior to CT scan for detection of temporal lobe pathology yet failed to detect abnormalities in some patients. The most common pathologies found were brain tumors, mesial temporal sclerosis and developmental lesions. In addition to seizure control, many patients experienced improvement in cognitive and psychosocial function following surgery.

Adolescent↗
PubMed2003

Prevalence of aspergillosis in bronchogenic carcinoma.

Bronchoalveolar lavage of 42 patients of bronchogenic carcinoma was studied to find out the prevalence of aspergillosis. Sera of the patients were also analysed for presence of anti-Aspergillus antibodies by Immunodiffusion (ID), Enzyme linked immunosorbent assay (ELISA) and dot blot assay (DBA). Aspergillus was isolated in culture from 6 (14.2%) patients of bronchogenic carcinoma. Aspergillus fumigatus was the predominant species isolated. All the strains of Aspergillus were sensitive to itraconazole, ketoconazole and amphotericin B while resistance (33.3%) was found with fluconazole. Anti-aspergillus antibodies were detected equally by ID, ELISA and DBA in 9 (21.4%) cases. The present study revealed prevalence and seroprevalance of Aspergillus in bronchogenic carcinoma to be 14.2% and 21.4% respectively. Consistent reactivity against 18 kDa Aspergillus fumigatus antigen was noted in serologically positive cases. Antibodies against 18 kDa protein antigen in western blotting may be used as a reference marker for diagnosis of aspergillosis in bronchogenic carcinoma. It is also suggested that the simplest serological technique like ID may be performed along with culture for diagnosing Aspergillosis in patients of bronchogenic carcinoma since ID, ELISA and DBA showed similar sensitivity.

Adolescent↗
PubMed2002

MRI characteristics of the neurocentral synchondrosis.

BACKGROUND AND OBJECTIVES: The neurocentral synchondrosis (NCS) is a cartilaginous growth plate that since the early 1900s has been implicated as a potential cause of adolescent idiopathic scoliosis (AIS). Previous studies have focused only on the closure age without characterizing normal NCS development. Using MRI, the normal development of the NCS image can be characterized, and the stages preceding the disappearance of this image can be specified. METHODS: A total of 405 NCSs were visualized in 11 normal pediatric patients using T1 and T2 transverse and sagittal MRI views. The images were correlated and the variety of images recorded to categorize the NCS into developmental stages. RESULTS: The development of the NCS was categorized into five developmental stages. The image of the NCS became absent in a specific pattern along the vertebral column, first in the cervical region (age 6), then in the lumbar region (age 12), and finally in the thoracic region (age 14). CONCLUSION: The normal development of the NCS at the level of individual vertebrae and also along the vertebral column as a whole was determined using MRI. These patterns of development are valuable and necessary to evaluate the role of the NCS in pathological conditions.

Adolescent↗
PubMed2002

Colour duplex Doppler ultrasonography evaluation of non-vasculogenic male erectile dysfunction: An Indian perspective.

We present the study of colour duplex Doppler ultrasonography on Indian patients with non-vasculogenic erectile dysfunction. Patients with a history suggestive of psychogenic impotence along with a normal clinical response to intracavernosal papaverine were presumed to have non-vasculogenic erectile dysfunction. In our patients, the incidence of psychogenic impotence was much higher and the mean age of patients presenting with erectile dysfunction was lower as compared to patients from developed countries reported in research. The Doppler flowmetry showed much higher mean peak systolic velocities (PSVs) with a negative correlation between age and PSV. End diastolic velocity, resistive index and acceleration time values conformed to the literature.

Adolescent↗
PubMed2002

Development of the neurocentral junction as seen on magnetic resonance images.

The neurocentral junction (NCJ) is a cartilaginous growth plate in the vertebra that has been implicated as a potential cause of adolescent idiopathic scoliosis (AIS) since the early 1900s. Studies to date have focused on the age of closure without characterizing normal NCJ development. Using MRI, the normal development of the NCJ image can be determined and the stages preceding the disappearance of the NCJ image can be characterized. 405 NCJs from 11 pediatric patients were examined using MRI and the various images were categorized. NCJ development encompassed five stages, with a specific pattern of absence of the NCJ image noted in each vertebra and in the vertebral column as a whole. The image of the NCJ first became absent in the cervical region (age 6), then in the lumbar region (age 12) and finally in the thoracic region (age 14). These patterns of development serve as a baseline to evaluate NCJ pathology in conditions such as adolescent idiopathic scoliosis (AIS).

Adolescent↗
PubMed2002

The components of the magnetic resonance image of the neurocentral junction.

The neurocentral junction (NCJ) is a cartilaginous growth plate located between the vertebral centrurn and the neural arch. In characterizing the age of closure of this growth plate, anatomic studies have suggested that the NCJ closes before age 10, whereas MRI studies have suggested that the NCJ does not fuse until adolescence In this study, gross anatomic and histologic sections were correlated with MR images to determine the components of the NCJ image. The NCJ image appeared as a thick white line that was shown to encompass the cartilage of the growth plate, the surrounding woven bone and a portion of the trabecular bone of the vertebra. Although the MR pixels were too large to completely resolve the tissues that surround the growth plate, MRI was shown to be a valuable technique of visualizing the NCJ cartilage and further MRI studies of the human NCJ are needed.

Age Factors↗
PubMed2001

Fourier transform infrared imaging: theory and practice.

The signal-to-noise ratio (SNR) of spectral data obtained from a microimaging Fourier transform infrared (FT-IR) spectrometer assembly, employing a step-scan interferometer and focal plane array detector, is analyzed. Based on the methodology of data collection, a theoretical description for the performance characteristics is proposed and quantitative effects of the acquisition parameters on the SNR are explained theoretically and compared to experiment. To obtain the best strategy for achieving either the highest SNR in a given time interval or for attaining a given SNR in the shortest time period, the concept of characteristic plots is introduced. The theoretical analysis is extended to FT-IR microimaging employing continuous scan interferometers in which the advantages of fast image collection are enumerated, while SNR limitations arising from mirror positioning errors are discussed. A step-scan method is suggested for faster data collection in which an optimal detector response and SNR benefits are retained. Theoretically obtained SNRs based upon the expressions proposed in this paper predict experimentally determined values quite well and can be used to obtain an understanding of the required developments for improved performance. Finally, SNRs for both microimaging systems and conventional microspectroscopic instrumentation are compared.

Journal Article↗
PubMed2001

FTIR images.

Explore the source record for details and available documents.

Journal Article↗
PubMed2001

Leber hereditary optic neuropathy, progressive visual loss, and multiple-sclerosis-like symptoms.

PURPOSE: To report a case of Leber hereditary optic neuropathy with multiple-sclerosis-like symptoms. METHODS: Observational case report. A 34-year-old man was found to have Leber hereditary optic neuropathy and a mutation at position 11778 of the mitochondrial genome. The progression of vision loss and onset of weakness in the right leg warranted neuroimaging. RESULTS: Magnetic resonance imaging documented multiple lesions in the brain and spinal cord. CONCLUSION: Although rarely reported, progression of optic neuropathy over months has been previously documented in Leber hereditary optic neuropathy. The emergence of multiple sclerosis-like symptoms and signs in our patient may be part of the spectrum of Leber hereditary optic neuropathy or a coincidental occurrence.

Adult↗
PubMed2001

Tyrosine kinase activation in breast carcinoma with correlation to HER-2/neu gene amplification and receptor overexpression.

The HER-2/neu oncogene encodes a transmembrane receptor with intrinsic tyrosine kinase activity. A pilot study was performed to investigate downstream effects of HER-2/neu (or related growth factor receptor) activation by identifying phosphorylated tyrosine. Fifty-four breast carcinomas were evaluated for HER-2/neu overexpression by the HercepTest (Dako, Carpinteria, CA) and the monoclonal CB11 antibody (Ventana, Tucson, AZ). Phosphotyrosine (an indication of tyrosine kinase activity) was detected by an antiphosphotyrosine mouse monoclonal antibody (Upstate Biotechnology, Lake Placid, NY). The gene amplification status was evaluated in 50 of the 54 cases by fluorescence in situ hybridization (FISH) using the Ventana gene probe. The HER-2/neu oncogene amplification was detected in 28% (14 of 50) of cases. Of the 14 cases showing oncogene amplification, tyrosine kinase activity was detected in 9 (64.2%) cases. There was moderate agreement between HER-2/neu gene amplification and tyrosine kinase activity (kappa = 0.43). Immunohistochemical staining of 3+ (with both HercepTest and CB11) showed better agreement with HER-2/neu oncogene amplification and increased tyrosine kinase activity than 2+ immunohistochemical staining. Overall, oncogene amplification and overexpression correlated with increased tyrosine kinase activity, supporting the mechanism of tyrosine kinase activation by HER-2/neu amplification and overexpression. However, 7 cases showing increased tyrosine kinase activity did not show gene amplification or 3+ receptor expression (by either HercepTest or CB11), raising the possibility of other growth factor receptors operating via the tyrosine kinase pathway. There was no apparent correlation between tyrosine kinase activity and hormone receptor status (estrogen or progesterone). Increased tyrosine kinase activity is more commonly associated with higher-grade tumors and thus may correlate with aggressive biologic behavior in breast carcinoma. The results of this pilot study suggest that a larger-scale investigation into downstream activation of tyrosine kinase and correlation to clinical outcome or response to Herceptin therapy may identify subsets of patients whose clinical response or outcome may be predicted by tyrosine kinase activation.

Adult↗
PubMed2001

Analysis of normal epithelial cell specific-1 (NES1)/kallikrein 10 mRNA expression by in situ hybridization, a novel marker for breast cancer.

PURPOSE: Normal epithelial cell specific-1 (NES1)/kallikrein 10 gene is expressed in normal mammary and prostate epithelial cells, but the expression of NES1 mRNA and protein is markedly reduced in established breast and prostate cancer cell lines although the NES1 gene is intact. Here, we wished to assess whether NES1 expression is down-regulated in primary breast cancers. EXPERIMENTAL DESIGN: We developed and used an in situ hybridization technique with an antisense NES1 probe to detect NES1 mRNA in sections of normal breast specimens, typical and atypical ductal hyperplasia, ductal carcinoma in situ, and infiltrating ductal carcinoma. RESULTS: All of the 30 normal breast specimens showed high NES1 expression. Notably, 18 (75%) of 24 typical and atypical breast hyperplasia specimens showed high NES1 expression, with weak-to-moderate expression in 6 (25%). Significantly, 13 (46%) of 28 ductal carcinoma in situ specimens lacked NES1 expression, and the remaining 15 (54%) showed weak-to-moderate expression. Finally, 29 of 30 (97%) infiltrating ductal carcinoma grades I-III samples lacked NES1 mRNA, with weak expression in the remaining one sample. CONCLUSIONS: Our results demonstrate that NES1 mRNA is expressed in normal breast tissue and benign lesions, with loss of NES1 expression during tumor progression. We suggest that NES1 expression may serve as a molecular tool in the study of breast cancer progression. Studies with larger series of specimens should help assess whether NES1 expression can be a diagnostic and/or prognostic marker in breast and other cancers.

Biomarkers, Tumor↗
PubMed2000

Primitive neuroectodermal tumor of the diaphragm: a case report.

We present a case of primitive neuroectodermal tumor (PNET) arising from the diaphragm in a neonate. PNETs are rare malignant tumors that belong to the group of small, round, blue-cell neoplasms of childhood. To the best of our knowledge, a PNET originating from the diaphragm has not been previously reported.

Age Factors↗
PubMed2000

Diffuse neonatal haemangiomatosis.

A newborn girl with severe diffuse neonatal haemangiomatosis is described. She was treated with high dose systemic corticosteroids and high dose interferon-alpha-2a, but with fatal outcome. A review of the current literature is presented.

Adrenal Cortex Hormones↗