Search PubMed⌕ Search

Biomedical subjects

P Prakash

Publications and source records attributed to P Prakash.

At least 19 recordsLinked to original sources
PubMed1992

45Ca-efflux in embryonic chick heart and its modification by caffeine and ryanodine.

Ontogenic changes in the kinetics of exchangeable cellular calcium were studied in embryonic (ECV) and post-hatch (PHCV) chick ventricular tissue by monitoring 45Ca-efflux. The isolated whole ventricle (5 & 7 days ECV) or ventricular strips (12 & 18 days ECV and 1-2 days PHCV) were "loaded" with 45Ca (37 degrees C) and then passed through a series of tubes containing efflux solution (4 degrees C) to determine 45Ca-efflux. Curve 'peeling' of the efflux curve indicated existence of 3 kinetically distinct components of exchangeable cellular Ca2+ compartments: C1, C2 & C3. The size of C1, which was the largest in 5 & 7 days ECV decreased significantly to become minimum in 18 days ECV & PHCV. The rate constant of this compartment, however, reduced with the age of the embryo. In contrast, the size of C3 increased with the embryonic development to become the largest in 18 days ECV & PHCV. An increase in the rate constant of this compartment was also observed during embryogenesis. The size and rate constant of C2 remained unaltered during development. However, the increase in size of C3 during embryonic development indicates differentiation of Ca2+ storage sites, like sarcoplasmic reticulum (SR), during the later stages. Caffeine (10 mM) and ryanodine (10 microM) enhanced fractional escape rate during slow phase (ie 120-180 min) of efflux at all developmental stages. The magnitude of enhancement increased during later stages of development indicating greater prominence of SR with the age of embryo.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Enriched collagen as coadjuvant therapeutic agent in experimental osteomyelitis in dogs.

Osteomyelitis was induced in the tibiae of dogs by injecting hemolytic strain of Staphylococcus aureus. Clinical, radiological and histomorphological reactions in the diseased tibiae were studied up to 15 weeks to evaluate the response of infected bone to parenteral oxytetracycline in cases of closed wounds and surgical curettage, antimicrobial irrigation along with parenteral oxytetracycline therapy in animals carrying open wounds. Enriched collagen as a constituent of therapeutic regimen was also administered locally and its efficacy during resolution of osteomyelitis was compared with other treatments. Surgical curettage along with irrigation of lesions was observed to be an effective method for bringing an early recovery in aggravated cases of osteomyelitis. The addition of collagen enhanced the healing process in comparison with non-collagen treated animals.

Adjuvants, Pharmaceutic↗
PubMed1990

The vasopressin response to severe birth asphyxia.

Serial measurements of urinary arginine vasopressin (AVP) were made in six severely birth asphyxiated newborn infants. In five infants serial plasma concentrations were also evaluated. There was a strong negative correlation between plasma AVP and plasma osmolality in these infants (r = -0.52, P = 0.0012). In neither the individual babies nor the group as a whole was there a significant correlation between plasma AVP and the urinary excretion of AVP even if the latter was standardised for creatinine content. Normal development at follow up was only observed in two asphyxiated infants who had consistently low urinary arginine vasopressin levels in the first days of life. Infants with consistently high urinary vasopressin concentrations either died or were severely abnormal in their subsequent development.

Apgar Score↗
PubMed1990

Scleral dellen in strabismus surgery.

This communication highlights scleral dellen as an unusual complication of strabismus surgery in a 55-year-old hypertensive male. The clinical significance, differential diagnosis and management of this condition has been discussed.

Humans↗
PubMed1990

Air leaks and vasopressin release.

Eleven very low birthweight babies being ventilated for respiratory problems during the first week of life developed air leaks on 22 occasions. On 16 out of 19 occasions the infants showed increases in urinary excretion of vasopressin after these events and on 10 occasions out of 13 there was a rise in the plasma arginine vasopressin concentration. The peripheral signs of the syndrome of inappropriate antidiuretic hormone release were seen on only one occasion in response to the sometimes high vasopressin concentrations.

Arginine Vasopressin↗
PubMed1978

A quantitative histological study of the aortic nerve and the aortic body in the buffalo (Bubalus bubalis).

In the buffalo, the left aortic nerve ramifies in the periarterial connective tissue between the ventral surface of the aortic arch and the truncus pulmonalis. The right aortic nerve ramifies over the dorsal and right aspects of the aorta ascendens near its origin. The histograms of myelinated fibres of both left and right aortic nerve are distinctly unimodal with peak around 4-6 micron (64.2-67.8%). The left aortic body is situated in the periarterial connective tissue between the ventral surface of the aortic arch and the truncus pulmonalis, while the right aortic body is located in the tunica adventitia of the dorsal and right aspects of the aorta ascendens near its origin. The greatest sagittal section area of the left aortic body is 0.102 +/- 0.009 mm2 and that of the right aortic body is 0.041 +/- 0.002 mm2. The organ is highly vascular. The mean size of the glomus cells from the left aortic body is 7.68 +/- 0.9 micron x 9.37 +/- 0.13 micron (short diameter x long diameter), whereas the corresponding value for the right aortic body is 7.84 +/- 0.14 micron x 9.86 +/- 0.21 micron; and their density values are (11,417 +/- 301.7)/mm2 and (9,839 +/- 213.3)/mm2 respectively.

Animals↗
PubMed1978

Morphological changes in cooked longissimus dorsi muscle of pig, buffalo, sheep, goat and poultry.

In an effort to establish the morphological differences between the cooked muscles of pig, buffalo, sheep, goat and poultry longissimus dorsi were examined. Cooking at 100 degrees C produced shrinkage of muscle fibres in all species. The demarcation of the fascicles was also lost. Cooking at 121 degrees C destroyed even the granulated structure of collagen, reducing it to an amorphous state. The transverse striations were lost and the muscle fibres showed cracking, breaking and splitting. In relation to the control the per cent values of the cross-sectional area of the muscle fibre after treatment at 100 degrees C decreased by 28.6% in pig, 17.8% in buffalo, 20.4% in sheep, 24.3% in goat and 34.8% in poultry, whereas the respective values after cooking at 121 degrees C were 38.3%, 28.6%, 32%, 33.9% and 44.1%. Besides, the muscle fibre diameter in all species was also reduced after cooking. The number of muscle fibres and fascicles per mm2 were found to increase after cooking at 100 degrees C and 121 degrees C.

Animals↗
PubMed1978

Structural changes in the thyroid gland of buffalo following administration of thiouracil.

The effects of a goitrogen (thiouracil) on the structural variations of the thyroid gland were studied in male buffalo calves. Following the treatment, the thyroid became enlarged and both the weight and the size of the gland were significantly increased (P less than 0.01). Hyperplasia and hypertrophy of the gland were correlated with a significant increase of thyroidal uptake of 131I. The height and number of the follicular cells were significantly increased (P less than 0.01). The follicles were small and had vacuolations in the colloid. The colloid content of the follicles became reduced. The vascularity of the gland was appreciably increased.

Animal Feed↗
PubMed1977

Autoradiographic localization of 131I-labelled thyroxine in the tissues of rat.

An attempt was made to visualize the sites of localization of 131I-labelled thyroxine in the tissues of the rat by autoradiographic dipping techniques. The maximal uptake of 131I-throxine in rats occurred at 12 hours in all the tissues examined. The radioactivity continued to decrease from 12 to 36 hours after the injection. In the liver and kidney, the decline after 12 hours was rather marked. The radioactivity decreased only slightly from 12 to 36 hours in the spleen. After 3 hours of injection, the radioactivity was consistently higher in the thyroid follicular epithelial cells than in the interfollicular connective tissue. A high concentration of radioactivity was found at the periphery of the colloid areas.

Animals↗
PubMed1976

Localization of radioiodine in the tissues of swine: an autoradiographic study.

An attempt was made to visualize the sites of accumulation and distribution of 131I and 125I in the organs and tissues of swine by a modified autoradiographic dipping technique. Radioactivity was substantially higher with the injection of 125I than that of 131I. There was a tendency in all tissues for concentration of radioiodine to vary with the age of the animals. Concentration was evident in the lung, muscle, liver, pancreas, intestinal mucosa, thymus and spleen, in addition to the known accumulation sites, such as the adrenal, pituitary and gonads. The isotopes were concentrated at the striated border of the epithelial cells of the duodenum. The submandibular gland had a marked concentration in the collecting ducts and a lesser one in the secretory parenchyma of the gland. The most radioactive organ examined was the thyroid gland. The readioactivity was consistently higher in the follicular epithelial cells than in the connective tissue between the follicles. The bound radioiodine formed rings over the colloid-cell interface.

Age Factors↗
PubMed1976

A morphological study of the carotid body and the fibre content of carotid nerve in the buffalo.

In the buffalo the carotid body is located in the periarterial connective tissue of the occipital artery immediately cranial to the bifurcation of the common carotid artery. The carotid body is lobulated and does not appear to contain chromaffin tissue. Nerve terminals have been seen in close relation to the glomus cells. A quantitative study of the fibre content of the carotid nerve and the carotid body has also been made. The myelinated fibres in the carotid nerve range from 278 to 473, with a mean of 368 +/- 39 fibres. The histogram of myelinated fibres is distinctly unimodal. Of the myelinated fibre population, 55.4% of fibres have diameters of 2 mum, 34.1% of 4 mum, 9.5% of 6 mum and 1% have diameters of 8 mum. The mean greatest sagittal sectional area of the carotid body is 0.58 +/- 0.09 mm2. The mean density (per mm2) of glomus cells is 9,216 +/- 378. It appears that the organ is highly vascular (473 +/- 56 blood vessels/mm2 area). The mean size of the glomus cells is 7.85 +/- 0.46 mum X 10.02 +/- 0.64 mum (short diameter X long diameter), whereas the mean size of their nuclei is 4.96 +/- 0.19 mum X 5.52 +/- 0.27 mum.

Animals↗
PubMed1976

Effect of ethanol on angina pectoris.

We evaluated the effect of ethanol on exercise performance until angina in 12 patients in a double-blind, randomized study. The mean resting heart rate times systolic blood pressure was not changed after Fresca but was increased after 2 ounces of ethanol (P less than 0.001) and after 5 ounces of ethanol (P less than 0.01). Compared to the control periods, the mean exercise time until angina was not different after Fresca but was decreased after 2 ounces of ethanol (P less than 0.001) and after 5 ounces of ethanol (P less than 0.001). Compared to the control periods, the mean maximal ischemic ST-segment depression after angina was not changed after Fresca but was increased after 2 ounces of ethanol (P less than 0.01) and after 5 ounces of ethanol (P less than 0.001). Drinking 5 ounces or 2 ounces of ethanol decreases exercise duration until angina and increases ischemic ST-segment depression after angina.

Administration, Oral↗
PubMed1976

An autoradiographic study on the localization of 131I-labeled thyroid hormones in the tissues of the pig.

Autoradiographic studies on the localization of 131I-labeled thyroxine and triiodothyronine in the various organs and tissues of the pig have been conducted. The isotopes were compared as to the intensity of radioactivity on the basis of the concentration of developed silver grains in the tissues following the respective radioactive hormone injections. In general, for an identical dose of the isotope and with analogous processing procedures, the autoradiographs of most of the tissues after triiodothyronine were relatively more radioactive than after thyroxine. In both the hormone treatments, the tissues from younger pigs were relatively more radioactive than the tissues of older pigs. The various tissormones. Based on differential localization of radioactivity, the pigs excreted more radioiodine through bile, pancreatic and salivary secretions and in urine.

Age Factors↗