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Biomedical subjects

R Prakash

Publications and source records attributed to R Prakash.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Echocardiographic evaluation of the effect of hemodialysis on cardiac size and function in patients with end-stage renal disease.

Twelve stable patients with end-stage renal failure maintained on hemodialysis were studied by echocardiography before and after dialysis. The left ventricular (LV) end-diastolic wall thickness, interventricular septal thickness and LV mass were increaed suggesting concentric LV hypertrophy. The LV end-diastolic and end-systolic volumes, and cardiac output were increased before dialysis. Aortic root dimensions, aortic valve opening, left atrium, LV wall and septal excursions and per cent LV internal diameter shortening were normal before dialysis. Some pericardial effusion was found in 50% of the patients without any symptoms or signs. With dialysis the systolic and diastolic volumes and dimensions of the left ventricle and atrium decreased significantly as did the stroke volume. These changes were associated with a significant reduction of body weight, and thereby blood volume, induced by dialysis. The cardiac output remained unchanged despite significant reduction in the stroke volume due to an increase in heart rate.

Adult↗
PubMedDate not supplied

Electrocardiographic and echocardiographic characteristics of long distance runners. Comparison of left ventricular function with age- and sex-matched controls.

Nineteen long distance runners and 19 age- and sex-matched sedentary controls were evaluated by echocardiography and electrocardiography (ECG) at rest and after 12 minutes of treadmill exercise. Seven of ten male athletes exhibited ECG abnormalities of prominent precordial voltage, early repolarization, and one had right ventricle hypertrophy; only three of nine females had ECG abnormalities. The resting and postexercise heart rates and blood pressures were lower in athletes than controls (P less than 0.001). The athletes increased their left ventricular end-diastolic volume and stroke volume and had a moderate increase in heart rate. Controls markedly increased only their heart rate to the same level of exercise. One female athlete and one female control had 1 mm of ST segment depression with exercise. The right ventricular wall thickness was equal to or greater than 6 mm in athletes versus equal to or less than 5 mm in controls. The left ventricular wall was thicker in athletes than controls, the resultant left ventricular mass was 60% more in athletes due to left ventricular hypertrophy (P less than 0.001). We concluded left ventricular hypertrophy is present in athletes as a result of endurance running.

Adult↗
PubMedDate not supplied

Copper(II) ion-selective microelectrochemical transistor.

A device has been developed for the measurement of copper(II) ions (Cu++) in aqueous medium. The device reported here is an electrochemical transistor that consists of two platinum electrodes separated by 100-microm spacing and bridged with an anodically grown polycarbazole film. The undoped polycarbazole film is observed to be highly selective for the Cu(II) ions. In a completed device, the conductivity of the polycarbazole film changes on addition of Cu (II)ions. This change in conductivity is attributed to the conformational changes in the polymer phase on occupation of the Cu(II) ions, without affecting electron/proton transfer. The device turns on by adding 2.5 x 10(-6) M Cu(II) ions and reaches a saturation region above a concentration of 10(-4) M Cu(II) ions. In this concentration range, the plot of I(D) vs log[Cu(II)] is linear. The selectivity of the device for other metal ions such as Cu(I), Co(II), Fe(II), Fe(III), Zn(II), and Pb(II) is also studied.

Copper↗
PubMedDate not supplied

Endodontic management of taurodontic teeth.

Taurodontism is a morpho-anatomical change in the shape of the tooth in which the body of the tooth is enlarged and the roots are reduced in size. Although taurodontism is a dental rarity, this unusual radicular form should merit circumspect considerations in planning and treatment. Endodontic management in taurodont teeth has been described as complex and difficult. The present paper describes the successful completion of endodontic treatment in three taurodontic teeth with appropriate use of instruments and techniques and also emphasizes the need for post endodontic rehabilitation.

Calcium Hydroxide↗
PubMedDate not supplied

Fine needle aspiration cytologic diagnosis of the solitary cold thyroid nodule. Comparison with ultrasonography, radionuclide perfusion study and xeroradiography.

Thirty-six cases of solitary and scintigraphically "cold" thyroid nodules were studied by fine needle aspiration (FNA) cytology, ultrasonography, radionuclide perfusion study (RPS) and xeroradiography with the aim of differentiating the neoplastic from the nonneoplastic nodules. Histologic study of the excised specimens provided the definitive diagnosis in all cases. Of the techniques used in this study, FNA cytology and RPS had the highest sensitivities and specificities. Ultrasonography and xeroradiography were of limited use due to their low sensitivity rates.

Adenocarcinoma↗