PubMed Health⌕ Search

Biomedical subjects

A Parameswaran

Publications and source records attributed to A Parameswaran.

At least 19 recordsLinked to original sources
PubMed2005

Maxillary second premolar with three roots and three separate root canals--case reports.

Aberrations in root canal systems are a commonly occurring phenomenon. Knowledge of the basic root canal anatomy and its variation is necessary for successful completion of endodontics. Maxillary second premolars usually have one root and one canal. The occurrence of these teeth having three roots and three canals is very rare. Three such cases of maxillary second premolar with three roots and three canals are presented here.

Adult↗
PubMed2004

In vitro testing to diagnose venom allergy and monitor immunotherapy: a placebo-controlled, crossover trial.

BACKGROUND: In people with a history of sting allergy, only prior reaction severity and older age are known to predict subsequent reaction risk. Furthermore, no diagnostic test other than a deliberate sting challenge has been found to identify people in whom venom immunotherapy (VIT) has been unsuccessful. OBJECTIVE: We aimed to assess the utility of a number of in vitro tests to diagnose venom allergy and to monitor immunotherapy. METHODS: During a double-blind randomized placebo-controlled crossover trial of Myrmecia pilosula ant VIT the following venom-specific tests were performed at enrolment, and at completion of treatment prior to a diagnostic sting challenge; leucocyte stimulation index (SI), IL-4 production, IgE RAST, histamine release test (HRT), leukotriene release test (LRT) and basophil activation test (BAT). Intradermal venom skin testing (VST) was also performed at trial entry. RESULTS: Only VST and HRT identified those at risk of sting anaphylaxis in the placebo group. Although IgE RAST, leucocyte SI and IL-4 production, LRT and BAT all correlated well with intradermal VSTs, they did not predict sting challenge outcome. After successful VIT, venom-induced leucocyte IL-4 production tended to fall, whereas IgE RAST increased and a natural decline in HRT reactivity was reversed. A confounding seasonal affect on laboratory results was suspected. CONCLUSION: The HRT warrants further assessment for diagnosis of venom allergy. Uninformative performance of the commercially available LRT and BAT tests may be due to pre-incubation with IL-3. None of the tests evaluated appear to be reliable markers of successful VIT.

Animals↗
PubMed2003

Effectiveness of prophylactic use of rofecoxib in comparison with ibuprofen on postendodontic pain.

The purpose of this study was to determine if prophylactic rofecoxib would significantly reduce postendodontic pain, when compared with ibuprofen or placebo. An additional objective was to establish if any relationship exists between periapical diagnosis and the need for additional medication after completion of pulpectomy. A total of 45 patients consented to a double-blind, single-dose oral administration of 50 mg of rofecoxib, 600 mg of ibuprofen, or a placebo before conventional root canal therapy. The root canal treatment was performed in two appointments. Patient-reported visual analog scale ratings of pain intensity were conducted upon initial clinical presentation and at 4, 8, 12, 24, 48, and 72 h after completion of pulpectomy. Results showed that at the 4- and 8-h periods, both rofecoxib and ibuprofen provided significantly better pain relief than placebo. At the 12- and 24-h periods, rofecoxib demonstrated significantly better pain relief than both ibuprofen and placebo. Patients with a periapical diagnosis of acute apical periodontitis showed a significantly increased need for additional medication after completion of pulpectomy compared with all other periapical diagnoses.

Acute Disease↗
PubMed2002

Scanning electron microscopic and energy dispersive spectrometric investigations on the effect of XeCl excimer laser on human dentin with smear layer.

The purpose of this study was to study the effect of XeCl excimer laser on smear layer covered dentine of extracted human teeth. Twenty-four freshly extracted human molar teeth were collected and randomly divided into one control group and three experimental groups of six teeth each (groups A-D). The teeth in the experimental groups were irradiated with XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2 and a constant pulse repetition rate of 25 Hz. Group A was used as the control, while groups B, C and D were irradiated at different exposure times of 3, 5 and 7 s, respectively. Subsequently these teeth specimens were subjected to scanning electron microscopic (SEM) examination and energy dispersive X-ray (EDX) spectrometric analysis. The SEM examination revealed melting of the smear layer covered dentin to conceal the underlying dentinal tubules. At a longer exposure time (7 s), dentin melted to form large grains and this resulted in non-uniform closure of underlying dentinal tubules. Under the conditions of this study, it is concluded that the pulsed XeCl 308-nm excimer laser at a fluence of 0.4 J cm-2, with an exposure time of 5 s uniformly occluded exposed smear layer covered dentine with no conspicuous variation in chemical structure.

Calcium↗
PubMed1996

A comparison of canal preparation using the K-file and Lightspeed in resin blocks.

Twenty-four resin blocks with simulated curved canals of approximately 38 degrees were divided into two groups of 12 each. One group was instrumented with stainless steel K-files and the other group with nickel-titanium Lightspeed Rotary instruments. The efficiency of canal preparation was evaluated at 1, 3, 5, and 7 mm from the apex using magnified images (x4) of the radiographed blocks. The results showed that K-files caused more widening at the apical end, with a higher incidence of transportation, zipping, and elbow formation. The Lightspeed instrument stayed centered in the canals maintaining the central axis, with minimal incidence of transportation, elbow formation, and zipping. Thus, the Lightspeed instrument may be considered more suitable for efficient preparation of curved canals than the K-type file.

Dental Instruments↗
PubMed1996

Intrasellar paraganglioma: report of a case in a sibship of von Hippel-Lindau disease.

Although uncommon, paragangliomas are known to affect the central nervous system. Those that arise in the sellar region are particularly rare. We report the clinicopathological features of a paraganglioma occurring in the setting of von Hippel-Lindau disease, a disorder in which paragangliomas are known to occur. We also present a review of the literature.

Adolescent↗
PubMed1993

Apical third instrumentation of curved canals with K-type and canal master instruments.

Forty acrylic blocks with curved canals were divided into two groups of 20 each. One group had canals with 30-degree curvature and the other with 45-degree curvature. Each group was divided into two subgroups of 10 blocks each. One subgroup was instrumented with precurved Kerr files and the other was instrumented with Canal Master hand instruments. The efficiency of the two instruments for preparing the apical third of curved canals was compared. In plastic blocks, Canal Master caused less transportation and was more suitable for instrumenting the canals.

Dental Cavity Preparation↗
PubMed1992

Salivary flow and dental caries in Indian children suffering from chronic malnutrition.

Chronic protein-energy malnutrition during the period of growth and development causes permanent disturbances of salivary gland function and tooth structure. Moderate protein-energy deficiency also causes impaired saliva secretion rate and composition in the adult rat. These impairments have been shown to coincide with an increased incidence of dental caries. In the present investigation we studied the effect of chronic malnutrition on saliva secretion rate and susceptibility to dental caries in Indian children. It was found that chronic malnutrition reduced the secretion rate of stimulated saliva, but not that of unstimulated saliva. The salivary buffer capacity was continuously decreased as the secretion rate decreased with the level of malnutrition in the Indian children. The malnourished children developed increased caries. Thus, it could be concluded that chronic malnutrition in growing children enhances the cariogenic potential stemming from fermentable carbohydrates.

Body Height↗
PubMed1983

Renal lesions in the obliterative cardiomyopathies: endomyocardial fibrosis and Loffler's endocarditis.

Electron and, or light microscopic examination of paraffin embedded renal tissue obtained from necropsies on eleven patients with obliterative cardiomyopathy showed a variety of abnormalities. Glomerular lesions present in patients with endomyocardial fibrosis included capillary wall thickening, basement membrane duplication, mesangial expansion and interposition, intraluminal fibrin and dense subendothelial deposits. These changes, some of which have been reported earlier in patients with Loffler's endocarditis, probably result from deposition and organisation of immune complexes.

Adolescent↗