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Biomedical subjects

H Venkatakrishna-Bhatt

Publications and source records attributed to H Venkatakrishna-Bhatt.

53 records · Page 3Linked to original sources
PubMed1976

Syndrome of depressed vital functions in the immediate post-operative period of surgical patients: some aspects of its pathogenesis.

Fifty adult male and female surgical patients (age 25--40 years) undergoing elective and emergency surgical procedures were subjected to isocapnoeic, hypocapnoeic and hypercapnoeic ventilation during anaesthesia; the PaCO2 ranged between 22--90 mm Hg. Three developed the syndrome of depressed vital functions in the post-surgical period by scoring less than 7 out of 10, the others recovered normally with complete resotration of reflex activity, consciousness and skeletomuscular tone, scoring on an average 8 out of 10 points. The role of muscle relaxant drugs in this syndrome and also the depression of the central nervous system is discussed.

Adult↗
PubMed1975

Toxicological effects of intravenous administration of pyridine in anaesthetized dogs.

In 17 anaesthetized dogs effects on blood pressure, respiration and biochemical changes in blood, i.e. serum glutamic oxaloacetic transaminase (SGOT), alkaline phosphatase (Alk.Pase), and urea, after intravenous administration of pyridine at various dose levels of 88 to 880 mg/kg body weight (LD5 to LD50) are reported. Commonly observed toxicity signs and symptoms are due to action of pyridine on the nervous system. There is no direct evidence of lowering of blood pressure. Lowering of blood pressure is noticed only at lethal doses and is accompanied by marked tachycardia. Death is due to respiratory failure. The significant biochemical changes are increase in SGOT and blood urea (p less than 0.01) and decrease in serum Alk,Pase (p less than 0.01).

Alkaline Phosphatase↗
PubMed1975

Pressor response induced by local anaesthetics perfused through the cerebral ventricles of dogs.

1 The antihistamines mepyramine and halopyramine which have local anesthetic properties, produced a rise in arterial blood pressure followed by a fall, similar to that seen with procaine, when perfused in a 10 mg/ml solution from the lateral ventricle to the cisterna magna in dogs. 2 The pressor response produced by procaine perfused through the cerebral ventricle is due to an action on structures situated in the caudal half of the floor of the fourth ventricle because a pressor response was obtained when a few microlitres of a 50 mg/ml solution of procaine were applied to a small area of the exposed floor of the fourth ventricle in a region 2 to 4 mm rostral to obex, and after cauterization of this area procaine perfused through the cerebral ventricles no longer raised arterial blood pressure. 3 Bilateral denervation of the carotid sinus did not affect the pressor response obtained with procaine perfused through the cerebral ventricles. 4 The pressor response to procaine is mediated through the sympathetic nervous system. It results partly from an increased adrenaline discharge from the adrenal glands and partly from increased sympathetic vasomotor tone, because the response is abolished or attenuated after removal of the adrenal glands and intravenous injections of hexamethonium and phentolamine.

Adrenal Glands↗
PubMed1975

Role of thiopentone, nitrous oxide and relaxant anaesthesia in causing the syndrome of post-operative paralysis in man.

Forty-seven patients undergoing elective/emergency surgery were investigated for the recovery pattern by numerically scoring the state of consciousness, skeletomuscular tone, respiration and blood pressure after the neuromuscular transmission at the level of thenar muscles returned to normalcy. Anaesthesia in them consisted of thiopentone induction and passive ventilation with nitrous oxide and oxygen mixtures (4 1/2:2 1/2 1) with consequent changes in PaCO-2 (22.0 to 90 mm Hg) after using 0.43 to 0.68 mg/kg d-tubocurarine or 2.3 to 3.8 mg/kg gallamine. In this series twelve patients were selected at random and biological assay of cerebrospinal fluid in them for curare/gallamine after 15 min anaesthesia and in the recovery phase was carried out on frog rectus muscle. All the patients recovered satisfactorily and did not present clinical signs of depression of central nervous system, even though all of them showed the presence of curare (ranging from 0.05 to 0.33 mug/ml) and gallamine (from 0.1 to 0.75 mug/ml) in the cerebrospinal fluid. This study therefore indicates that thiopentone, nitrous oxide and relaxant type of anaesthesia does not cause clinical syndrome of post-operative paralysis even when mild to moderate degree of hypocapnia is present and even when such a technique of anaesthesia is administered in poor-risk patients with associated changes in acid-base balance, electrolytes etc. Significant quantities of skeleto-muscular relaxant drug (used during the technique) when found in cerebrospinal fluid after the technique of anaesthesia need not induce post-operative paralysis in man.

Adult↗
PubMed1968

Procaine perfused into cerebral ventricles and subarachnoid space in conscious and anaesthetized dogs.

1. Perfusion of 1% procaine into the cerebral ventricles of conscious dogs produced mild paresis, defaecation, vomiting, jerky movements of eyelids, brisk nystagmus, increase in amplitude of respiration and sometimes loss of consciousness. Procaine 2% produced paralysis, loss of consciousness and sometimes respiratory depression.2. Procaine 2% perfused into the cerebral ventricles of dogs under chloralose anaesthesia produced an initial increase in amplitude of respiration, which preceded its final depression, which is due primarily to procaine and only partly to a change in pH.3. The site of action for the initial increase in amplitude of respiration was in the fourth ventricle, for it did not occur on perfusion of procaine into the cranial subarachnoid space.4. Perfusion of spinal subarachnoid space with procaine is enough to cause respiratory failure even when the procaine does not reach the medulla.

Anesthesia↗
PubMedDate not supplied

Effect of sensitized macrophages in transplantable sarcoma in mice. synergistic effect of hyperimmunized serum, sensitized spleen cells and macrophages in tumor transplantation.

BACKGROUND: Immunosuppression cannot develop tumors by itself. It may induce tumors under appropriate conditions and may accelerate tumor development which may be reversed by sensitized spleen cells. This study concerns the effect of sensitized macrophages in murine-transplantable sarcomas by a combination of hyperimmune serum, sensitized spleen cells and macrophages. METHODS: The main technique adopted was intraperitoneal (ip) injection of 2 mL of 10% protease peptone broth, followed 2 days later by inoculation into the peritoneum with 10-mL Hank isotonic solution. The cells from the pooled peritoneal fluid were tested by dye exclusion test to ascertain the percentage of live cells. They were tried in whole body-irradiated mice with a combination of immune serum and sensitized spleen cells to ascertain whether a suppression of growth of solid tumors could be achieved when subcutaneously (sc) administered with the previously mentioned combinations. RESULTS: The addition of immunomacrophages from transplanted tumor-bearing mice significantly suppressed the growth of subcutaneous solid tumors when the number of tumor cells was kept constant. A change in number of immunomacrophages from hyperimmunized mice at a ratio of 4:l showed a direct relationship in suppression of tumor growth. Experiments were initiated in which tumor cells were injected sc and peritoneal macrophages were injected either intravenously (iv) or ip. Experiments were then initiated to prove that cell-to-cell contact is essential for tumor suppression. In experiments in which tumor cells were administered sc and macrophages injected either iv or ip, a significant immunosuppressive effect was not shown, thus also indicating that regardless of which, cell-to-cell contact is an absolutely essential factor involved in tumor suppression. A combination of hyperimmune serum and macrophages was found to act synergistically. Macrophages and hyperimmune serum at a lesser proportion did not suppress tumor growth. Sensitized macrophages and spleen cells together significantly suppressed tumor growth in a pure isogenic strain of irradiated mice. The sensitized macrophages injected iv prolonged the survival period and retarded tumor growth. CONCLUSIONS: Tumor suppression by macrophages was found to be due to its contact with tumor cells that enables the effective transfer of immunity. Hyperimmune serum and other cells (macrophages, spleen lymphocytes) act synergistically toward each other and prolong the survival period.

Animals↗
PubMedDate not supplied

Distribution of isomers of BHC and related histopathology of liver in hexachlorocyclohexane (technical grade BHC) fed mice.

In an attempt to correlate body burden and related liver histopathology after exposure to 500 ppm benzene hexachloride, 6- to 8-wk-old male and female mice were fed benzene hexachloride with their mash diet for a 6-month period. The mice were divided into 8 groups (12/group; 6 experimental, 6 control) and were sacrificed by group monthly. During the first month, 3 groups of mice were sacrificed after 10, 20, and 30 days of treatment, respectively. A dose-related increase in liver weight was found in test animals (P less than .01). The histopathology of liver showed clear, oval cells; hypertrophied cells with foci; and neoplastic nodules that were apparent during the final 3- to 6-month period. Few oval and hypertrophied cells were found in control animals. The alpha isomer concentration of benzene hexachloride rose during the first 2 months of treatment, but declined after that time. A transient rise was noted for the beta isomer concentration of benzene hexachloride at the end of the 6-month period. The gamma isomer concentration was elevated during the initial 3 months of treatment, but declined during the subsequent 3 months. The results present definitive changes suggestive of precancerous states.

Animals↗
PubMedDate not supplied

Differential diagnosis of byssinosis by blood histamine and pulmonary function test: a review and an appraisal.

A study was conducted on byssinotic (N = 8) and nonbyssinotic (N = 16) mill workers exposed to cotton dust and on controls (N = 15) from a cotton dust-free zone. They were examined for chest tightness and breathlessness during successive days from Mondays to Fridays. In addition to monitoring the workers only on Mondays after shift work, their blood histamine levels and pulmonary function tests such as FEV1, PEFR, and FEF25-75% (PEFR represents airflow of larger airways, FEF25-75% reflects airflow in smaller airways, and FEV1 represents airflow in both central and peripheral airways) were screened, but Monday data were only counted to appraise a contrast between these two parameters. The results showed that the histamine levels were significantly higher in the cotton dust-exposed workers in association with significantly decreased FEV1, PEFR, and FEF25-75%, indicating bronchoconstriction of the central, larger, and peripheral airways. Histamine can cause a severe constriction of the central as well as peripheral airways in cotton dust-exposed workers, enabling a paradoxical effect for a differential diagnosis of byssinosis.

Adult↗
PubMedDate not supplied

Lithium effect: review on chemico-biologic interactions.

Lithium affects nerve excitation, synaptic transmitter and neuronal metabolism. These effects may be produced by alteration of ions transport or distribution, by inhibition of adenyl cyclase mediated responses or by more direct interference with neuronal metabolism. Which of these effects is responsible for the therapeutic benefit in mania, if any, is still unknown. This state of ignorance is directly related to conflicting interpretations and incomplete understanding of the manic state itself.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Effect of selenium dioxide on the testes of rat.

Selenium dioxide was administered (ip) to albino male rats (200 +/- 5 g) in increasing doses (2, 6 and 10 micrograms/rat, daily) for 90 days. Histologic and histometric study showed that there was dose dependent injury to testes. No cellular deformation was observed following 2 micrograms-dose; whereas 6 micrograms-dose caused significant damage of gametogenic cells. At a dose of 10 micrograms, there was a significant testicular degeneration along with testicular atrophy.

Animals↗