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Biomedical subjects

A Raja

Publications and source records attributed to A Raja.

At least 37 records · Page 2Linked to original sources
PubMed2003

Plasma antioxidant vitamins in brain tumors.

Plasma levels of vitamins A, E and C were analyzed in 102 patients with different types of brain tumors. A follow-up study was done with 27 postoperative patients. On comparison with plasma from normal individuals, vitamin A and E were decreased, but the decrease was statistically insignificant. Vitamin C levels remained in the normal range. In a comparative study of preoperative and postoperative cases, plasma vitamin A levels in postoperative glioma patients were significantly higher than those in the pre-operative state. There was no significant difference in the plasma level of vitamins C and E. The results of the present study suggest that the plasma antioxidant vitamins are not altered effectively in brain tumor cases.

Adult↗
PubMed2003

Unusual self-inflicted penetrating craniocerebral injury by a nail.

Penetrating injuries of the brain caused by a nail are rare. An interesting case of a patient with schizophrenia who attempted suicide by a self-inflicted penetrating intracranial injury using a nail is reported here. The literature related to this unusual case is reviewed.

Brain Injuries↗
PubMed2003

Delayed pharyngo-esophageal perforation: rare complication of anterior cervical spine surgery.

An injury to the pharynx and esophagus is a known complication of anterior cervical spine surgery. Two cases of delayed pharyngo-esophageal perforation following anterior cervical spine surgery that resulted in fistula are presented. We postulate that graft displacement and dislodgement of implant with resulting esophageal erosion was responsible for this complication.

Adolescent↗
PubMed2002

Pattern recognition technique in immunological antigenic tests to identify Mycobacterium tuberculosis infection.

UNLABELLED: The importance of a diagnostic test that is simple and quick to identify Mycobacterium tuberculosis infection needs no emphasis. The tuberculin skin test (TST - 1 TU RT23) is the diagnostic tool for identifying M. tuberculosis infection at present. The test reaction on the skin is measured after 48-72 h. It is observed that often multi-modes are seen, when the reactions are drawn as a graph and the bimodality is seen very feebly. Because of the difficulties in the administration of TST, several serological tests were developed over three decades, but none of the studies showed the desired results. One study to evaluate purified protein derivative (PPD) antigen resulted in a claim of 80% sensitivity and 4% false-positivity rate (14), while other researchers were not able to obtain similar results. In addition, several problems were encountered due to the non-availability of antigens, and data analyses from an ELISA-based diagnostic test showed considerable overlap of distributions of optical density (OD) values among patients and healthy individuals (10). Classical statistical techniques cannot explain the cause of these overlaps. Hence, an attempt is made in this article to resolve these difficulties by the pattern recognition technique (PRT). The technique lies in splitting the data into clusters using a supervised algorithm. The data set is normally split into a training set, a test set and a validation set. The PRT gets "trained" through the training data set until the infected and uninfected groups of individuals are correctly classified. The training occurs based on an algorithm on the training set. On successful completion of the training, this technique is further tested and validated in the respective data sets. SETTING: A total of 273 finger-prick specimens were collected from five categories (Al, A2, B, C, D, E) of subjects not vaccinated with (bacille Calmette Guerin) (BCG) from Trivellore BCG Trial area adopted by the Tuberculosis Research Center, Chennai, India. OBJECTIVE: The study was conducted with the primary aim of evaluating purified antigens--r38 kDa, PPD and 30 kDa--for their usefulness as diagnostic tools and to test the applicability of the PRT in the evaluation of diagnostic tests. Individuals in two main categories (definitely not infected categories Al, A2 and D, and definitely infected categories B, E and C based on reaction to TST) were assembled for the purpose. RESULTS: The overall PRT performance of 30 kDa was 72.3% sensitivity and 90.9% specificity for identifying M. tuberculosis infection, while the r38 kDa antigen recorded a sensitivity of 73.8% and a specificity of 84.6%. In the case of PPD, the results were not promising. CONCLUSION: This paper on ELISA-based diagnostic tests attempts to implement an optimal decision support system through PRT that would identify the outcome (as infected or non-infected) based on the OD values. The PRT was able to predict the outcome for individual suspects. Further, Kullback-Leibler distance measurement has validated the PRT in distinguishing infected individuals from healthy subjects (based on the OD values).

Adolescent↗
PubMed2001

Contemporary management of subarachnoid hemorrhage and vasospasm: the UIC experience.

BACKGROUND: Cerebral vasospasm is a well-known and serious complication of aneurysmal subarachnoid hemorrhage. The means of monitoring and treatment of vasospasm have been widely studied. Each neurosurgical center develops a protocol based on their experience, availability of equipment and personnel, and cost, so as to keep morbidity and mortality rates as low as possible for their patients with vasospasm. METHODS: At the University of Illinois at Chicago, we have developed algorithms for the diagnosis and management of cerebral vasospasm based on the experience of the senior authors over the past 25 years. This paper describes in detail our approach to diagnosis and treatment of aneurysmal subarachnoid hemorrhage and vasospasm. Our discussion is highlighted with data from a retrospective analysis of 324 aneurysm patients. RESULTS: Over 3 years, 324 aneurysms were treated; 185 (57%) were clipped, 139 (43%) were coiled. The rate of vasospasm for the 324 patients was 27%. The rate of hydrocephalus was 32% for those patients who underwent clipping, and 29% for those coiled. The immediate outcomes for those who underwent clipping was excellent in 35%, good in 38%, poor in 15.5%, vegetative in 3%, and death in 8% of the patients. For those who underwent coiling the immediate outcome was excellent in 64%, good in 14.5%, vegetative in 2.5%, and death in 14.5% of the patients. These statistics include all Hunt and Hess grades. For those patients who underwent clipping, 51% were intact at 6 months follow-up, 15% had a permanent deficit, 10% had a focal cranial nerve deficit, and 2% had died from complications not directly related to the procedure. For those patients who had undergone coiling, 75% were intact at 6 months follow-up, 12.5% had a permanent deficit, and 12.5% had a cranial nerve deficit, with no deaths. CONCLUSIONS: The morbidity and mortality of cerebral vasospasm is significant. A good outcome after aneurysmal subarachnoid hemorrhage is dependent upon careful patient management in the preoperative, perioperative, and postoperative periods. The timely work-up and aggressive treatment of neurological deterioration, whether or not it is because of vasospasm, is paramount.

Algorithms↗
PubMed2001

Spontaneous regression of a large lumbar disc herniation: report of an illustrative case.

A case of spontaneous regression of a large herniated disc at the lumbar level is presented. The disc regression correlated with clinical improvement and was documented on serial MRI studies. Although the phenomenon of spontaneous disappearance of decrease in size of herniated disc fragments is well known, the exact mechanism underlying this process remains unclear. This report discusses three possible explanations for disc regression: retraction into the intervertebral space, dehydration/shrinkage, and resorption due to inflammatory reaction.

Adult↗
PubMed2001

Specific and early detection of IgG, IgA and IgM antibodies to Mycobacterium tuberculosis 38kDa antigen in pulmonary tuberculosis.

The objective was to apply the purified 38kDa protein antigen of Mycobacterium tuberculosis in ELISA to estimate the IgG, IgA and IgM antibody levels in sera and circulating immune complexes of tuberculosis patients. Sera from smear and culture positive tuberculosis patients were positive for anti 38kDa IgG, IgA and IgM antibodies, with a sensitivity of 61%, 30% and 10%, respectively, and with a specificity of 100% for IgG. The sensitivity of the test improved to a level of 68% for IgG+IgA and of 71.4% for IgG+IgA+IgM without significantly compromising the specificity (IgG of 100%, IgG+IgA of 96%, IgG+IgA+IgM of 90%). Among the smear, culture-negative but X-ray-positive cases, 60% were serum positive for IgG antibody, while in smear-negative but culture-positive cases, 54% were positive for IgG antibody. Measurement of 38kDa antibodies showed a greater than 95% sensitivity in smear and culture-positive, and smear-negative and culture-positive patients, through a combination of assays for serum IgG and circulating immune complex antibodies, while the specificity was 100%.

Antibodies, Bacterial↗
PubMed2001

Serologic response to a secreted and a cytosolic antigen of Mycobacterium tuberculosis in childhood tuberculosis.

BACKGROUND AND AIM: Bacteriologic diagnosis of childhood tuberculosis is difficult, and alternate methods are needed. The utility of a serologic test for major secretory antigen (30 kDa) and a cytosolic antigen (16 kDa) of Mycobacterium tuberculosis was evaluated for the diagnosis of tuberculosis in children. METHODS: Enzyme-linked immunosorbent assay was used. Specific IgG, IgA and IgM antibodies were measured in the sera from 26 clinically and/or bacteriologically diagnosed cases of childhood tuberculosis and 61 normal children. RESULTS: Anti-IgG antibodies alone, against both 30- and 16-kDa antigens, were detected in 65.4% of patients. However, by combination of all three isotypes, increased sensitivities of 84.6 and 73%, with a specificity of 96.7% each, were obtained for 30- and 16-kDa antigens, respectively. CONCLUSIONS: We found good specificity and reasonably good sensitivity for detection of antibodies by enzyme-linked immunosorbent assay to 30-kDa antigen alone. The 16-kDa antigen did not perform as well.

Acyltransferases↗
PubMed2000

In vitro strand transfer from broken RNAs results in mismatch but not frameshift mutations.

An in vitro system to compare the fidelity of strand transfers from truncated vs full-length RNAs was constructed. A donor RNA, on which reverse transcriptase (RT)-directed DNA synthesis was initiated, shared homology with an acceptor RNA, to which DNAs initiated on the donor could transfer. All RNAs were derived from the N-terminal portion of the alpha-lac gene. On full-length donors, transfers occurred when DNAs migrated to the acceptor prior to being completed on the donor. On donors that were truncated, most transfers occurred after DNAs reached the end of the donor. Transfer products were amplified by PCR and used to replace the corresponding region in a vector containing the alpha-lac gene. Transformed Escherichia coli were screened for alpha-complementation by blue-white phenotype analysis, with white colonies scored as those with errors in alpha-lac. These errors were derived from RT synthesis and strand transfer. The mutant colony frequency approximately doubled for transfer products derived from truncated donors (0.026+/-0.005 vs. 0.053+/-0.011 (three experiments +/- SD), for full-length vs. truncated, respectively). The increases resulted from additional non-template-directed bases (mostly thymidines) added to the DNAs before transfer. Sequence analysis of DNAs synthesized on truncated donors showed that about 60% had additions (20/34); however, those without additions transferred at a much higher rate than those with. Transfer of the DNAs with additions always resulted in substitutions; no frameshifts were observed. Results are consistent with RT adding nontemplated nucleotides at template termini. Transfer and subsequent extension of these products is severely inhibited relative to products without additions. The potential relevance of these findings to retrovirus replication is discussed.

Base Pair Mismatch↗
PubMed2000

Bacteraemia.

Explore the source record for details and available documents.

Antibiotic Prophylaxis↗
PubMed2000

Role of antioxidant enzymes in brain tumours.

Erythrocyte antioxidant enzymes were analysed in 100 patients with intracranial neoplasm and in 47 controls. There was a significant decrease in RBC glutathione reductase (GRx) and superoxide dismutase (SOD) activity in most types of brain tumor cases. Patients with acoustic neurinoma showed a significant reduction in selenium-dependent glutathione peroxidase (Se-GPx) activity. A decrease in catalase (CT) activity was seen in most of the brain tumor patients but remained statistically insignificant when compared to controls. A significant increase in plasma ceruloplasmin concentration was observed in patients with glioma. These enzymes were also studied in 27 post-treatment cases. GRx activity returned to normal levels in these patients. RBC SOD and plasma ceruloplasmin levels showed a tendency to return to normal. Hence, a marked decrease in the antioxidant enzymes may have a role in the genesis of considerable oxidative stress in patients with brain tumors.

Adolescent↗
PubMed2000

Transcultural oral health care: 3. Dental care and treatment during the fast of Ramadan.

The aim of this paper is to highlight issues that may affect dental treatment and care of Muslim patients when they are fasting during Ramadan. Recommendations are provided on how to provide culturally sensitive oral health care for this community. By taking into account the beliefs and wishes of the individual, dentists will provide a service that is acceptable and appropriate to both the Muslim community and individual Muslims.

Appointments and Schedules↗
PubMed2000

Production & characterization of monoclonal antibodies to Mycobacterium tuberculosis.

BACKGROUND & OBJECTIVES: Monoclonal antibodies (MAbs) against Mycobacterium tuberculosis H37Rv culture filtrate (CF) were raised by immunizing BALB/c mice and characterization was done. Attempts have been directed towards identifying mycobacterial antigens in biological fluids by employing polyclonal and monoclonal antibodies specific for M. tuberculosis. Immunohistologic studies, using MAbs for the localization of whole or fragmented bacilli in the biopsy specimens were also carried out. METHODS: Intrasplenic IS and intraperitoneal i.p. routes of immunization, were compared. The MAbs were characterized for their isotype, binding specificity, nature of binding epitope, reactivity in immunoassays etc. RESULTS: IS and i.p. routes of immunization, were compared and i.p. was found superior. Ten MAbs designated TRC 1-10 were produced. Of these, 7 MAbs, TRC 1-7 reacted with the 30/31 kDa doublet (antigen 85 complex), TRC 8 with 12 kDa in addition to 30/31 kDa and TRC 9 and 10 with the 24 and 12 kDa antigens respectively. Six MAbs were classified as broadly cross reactive and 2 showed limited cross reactivity. TRC 8 and 10 showed species specificity. Employing TRC 8 in sandwich ELISA, antigen was detected in sera from 17 of 25 pulmonary tuberculosis patients and 3 of 20 controls. TRC 8 was found to be useful in detecting antigens specifically in M. tuberculosis and M. leprae infected tissues, by immunoperoxidase staining. INTERPRETATION & CONCLUSION: TRC 8 was found to be restricted in its reactivity to M. tuberculosis complex and M. leprae. TRC 8 may prove useful in immuno-diagnosis of tuberculosis.

Animals↗