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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↗
PubMed1987

Saccadic eye velocity in concomitant divergent squint.

Study was conducted on 10 normal subjects, 20 cases of unilateral divergent squint and 20 cases of alternating divergent squint. In unilateral divergent squint cases lateral rectus of nondominant eye showed overactivity on fixation with dominant eye. In the alternating divergent squint cases which had onset of squint at or after the age of 2 years showed increased saccadic velocity of medial rectus of non-dominant eye on fixation with dominant eye. Working hypothese have been suggested to explain these phenomena.

Eye Movements↗
PubMed1986

Anterior segment ischemia following extraocular muscle surgery.

An experimental study was conducted on rhesus monkeys using the technique of anterior segment fluorescein angiography to determine the changes that occur in the iris circulation following surgery on extraocular recti muscles in various combinations and to investigate the safe time limit to perform further surgery on the remaining recti muscles. Based on the results, the probable blood supply to the iris and its clinical significance is discussed. It is concluded that the often quoted clinical safe period of 6 weeks is not enough from the angiographic point of view, as the iris circulation is not fully normalized by that time.

Animals↗
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↗