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Biomedical subjects

K Reddy

Publications and source records attributed to K Reddy.

At least 91 records · Page 5Linked to original sources
PubMed1988

Slit ventricle syndrome with aqueduct stenosis: third ventriculostomy as definitive treatment.

Slit ventricle syndrome is a poorly understood entity characterized by features of raised intracranial pressure and small ventricles in shunt-dependent hydrocephalics. Five patients with this syndrome were treated with antisiphon devices, high pressure shunts, or subtemporal decompression, but continued to be symptomatic. Third ventriculostomy, performed as a last resort in these patients, gave encouraging results. The patient data, operative approach, and preliminary results are presented here.

Adult↗
PubMed1988

Effect of subarachnoid hemorrhage on intracranial pulse waves in cats.

The influence of vasoconstrictors of intracranial arteries on the amplitude and configuration of the intracranial pulse wave (ICPW) was investigated. Continuous pressure recordings from the descending aorta (systemic arterial pressure) and the third cerebral ventricle (intracranial pressure) were obtained from anesthetized cats. Computerized analysis of the configuration, amplitude, and frequency spectrum of ventricular wave (ICPW) and aortic pulse wave (SAPW) was performed. Artificial cerebrospinal fluid (CSF), blood, or 5-hydroxytryptamine (5-HT) was injected intracisternally. In 24 control cats, 2 ml artificial CSF was injected into the cisterna magna. This produced a significant increase in amplitude of the ICPW but no change in the SAPW. Ten animals received 14 intracisternal injections of 2 ml autologous blood which caused narrowing of the amplitude of the ICPW as well as of all its components (P1, P2, and P3), with no significant change in the SAPW's. Eight animals were also subjected to cisternal injection of 2 ml of a 10(-4)-M solution of 5-HT, resulting in findings similar to those produced by autologous blood. Frequency spectrum of the intracranial and aortic pulse waves showed a high degree of correlation between wave amplitudes and height of the fundamental wave in the FFT record. These results suggest that the cerebral vasospasm that follows cisternal injections of blood and 5-HT in cats can be diagnosed by analysis of the ICPW. This method may allow early diagnosis and continuous monitoring of cerebral vasospasm in humans.

Animals↗
PubMed1987

Multiple intracerebral arteriovenous malformations. A case report and literature review.

The presence of multiple intracerebral arteriovenous malformations (AVMs) in a single patient has only been very rarely reported. We present a patient with three separate angiographically demonstrable intracerebral AVMs, all of which were radiologically demonstrated and surgically removed without residual neurological deficit. A literature survey was conducted and all the previously described cases of multiple intracerebral AVMs are discussed, along with the potential diagnostic and therapeutic implications.

Abnormalities, Multiple↗
PubMed1987

The Carey-Coons percutaneous biliary endoprosthesis: a three-centre experience in 87 patients.

Eighty-seven patients with malignant obstruction of the biliary tract from three centres and deemed unsuitable for surgery underwent insertion of the 'Carey-Coons' transhepatic endoprosthesis. It was successfully introduced in all, with early relief of cholestasis in 97%. The 30 day mortality rate was 11.5%, which is lower than reported in series using different endoprostheses. Two fifths of patients had complications, especially cholangitis. Despite its ease of insertion the design of the endoprosthesis may be related to the high incidence of cholangitis and to formation of biliary sludge and occlusion found in follow up. Although the anchoring threads prevented migration, they may have played a role in infection at the skin entry site in four patients and in tumour seeding to the skin in a further two. Still further improvements in endoprosthesis design are desirable.

Adenoma, Bile Duct↗
PubMed1987

Carotid endarterectomy without indwelling shunts and intraoperative electrophysiologic monitoring.

Although carotid endarterectomy is a common surgical procedure in North America, controversies exist regarding the type of anesthesia, the use of indwelling shunts and the need for intraoperative cerebral monitoring. We present a prospective study of 100 carotid endarterectomies performed over a three year period by a single surgeon without the use of indwelling shunts, patch grafts, or EEG monitoring. The combined stroke and mortality rate was 1%. Our results confirm those of other authors; that indwelling shunts and EEG monitoring are not absolutely essential for a satisfactory outcome in carotid endarterectomies.

Aged↗
PubMed1987

Painless glossopharyngeal "neuralgia" with syncope: a case report and literature review.

Glossopharyngeal neuralgia is an uncommon craniofacial pain syndrome. An association with syncope is even less common. We report a case illustrating that the glossopharyngeal neuralgia-syncope syndrome can occur without pain in the sensory distribution of the glossopharyngeal nerve and that it can have similar consequences. We suggest that permanent cardiac pacing alone may be a viable option in the initial management of such cases.

Aged↗
PubMed1987

Ependyma of the central canal of the rat spinal cord: a light and transmission electron microscopic study.

Ependymal cells of the rat central canal were examined with a view to identifying features that distinguish them regionally and from their counterparts elsewhere in the ventricular system. The results revealed that the lining consisted for the most part of a pseudostratified layer of uniformly organised cuboidal to columnar ependymal cells present in largest numbers in lumbar and sacral segments and in the conus. Two cell variants were identified on the basis of the presence or absence of a radially directed cytoplasmic process originating from the base of the cell. The tanycytic form of ependymal cell was encountered along the entire length of the central canal but with increased frequency in caudalmost segments. Ependymal cells were largely similar in ultrastructural appearance along the length of the cord. Although they were also similar in appearance and orientation to their counterparts in the ventricles they did exhibit some unique features. The most notable were the prominent junctional complexes and associated filaments present along the lateral border of the cells near their apex and the abundance of intermediate filaments in tanycytes. The central canal of the filum differed most markedly from other segments of the cord and resembled in structure the primitive ependymal tube of the caudal cord in lower vertebrates. Ependymal cells of the cord were not sufficiently dissimilar morphologically from their counterparts in the ventricles to account for differences in proliferative capacity in response to localised injury. A factor that merits further study is the difference in numbers of tanycyte ependymal cells in the two locations for they may be the reactive elements that proliferate in response to injury.

Animals↗
PubMed1985

Cricothyroidotomy for prolonged ventilatory support after cardiac operations.

Forty-nine patients required prolonged ventilatory support after cardiac operations. Cricothyroidotomy was used routinely in these patients after approximately 7 days of endotracheal intubation. There were no infections of the median sternotomy wounds despite frequent colonization of the stoma. The only immediate complication was mild stomal bleeding in a patient taking anticoagulants. Nineteen patients (39%) died of underlying disease. The average duration of cricothyroidotomy was 59 days (range, 3 to 270 days). Cannulas were successfully removed in all survivors after an average of 38 days (range, 6 to 187 days). All of the patients were followed by personal interview, telephone contact, or contact with the referring physician. The average length of follow-up was 17 months (range, 2 to 50 months). All symptomatic patients were evaluated by laryngoscopy and bronchoscopy. One patient required endoscopic removal of granulation tissue from the stomal site; 2 others required tracheal resection for stenosis at the balloon site. There were no instances of subglottic stenosis. There were 4 late deaths, none of which was related to the cricothyroidotomy. Based on these findings, we suggest that cricothyroidotomy, with its low complication rate, is the procedure of choice for patients requiring prolonged mechanical ventilation after cardiac operations.

Cardiac Surgical Procedures↗
PubMed1984

Gossypin-induced analgesia in mice.

A flavonoid, gossypin, was evaluated for its analgesic action by using acetic acid-induced writhing in mice and was compared with morphine. Gossypin inhibited writhing in a dose-dependent manner. This action was antagonised by naloxone. The pA2 values for morphine-naloxone and gossypin-naloxone were almost identical suggesting a definite involvement of opiate receptors in the analgesic action of gossypin.

Analgesia↗
PubMed1981

A clinical experience with the NCGT graft.

A comparison of 130 grafts done in 101 patients included 47 veins, 25 Johnson & Johnson dialdehyde-starch-tanned collagen prostheses, and 58 NCGT grafts that had been followed for a 40-month period. This study had documented the fact that in spite of frequent poor runoff, a useful result is provided by the NCGT graft apparently due in part to its built-in nonthrombogenic structure providing a cumulative patency of 73%. The patency rate was even superior with venous bypasses. Therefore, we still feel that the autogenous vein provides the most useful bypass conduit available in vascular reconstruction. In situations where a vein could not be used or was not available the NCGT graft offers an equally useful nonthrombogenic surface to maintain prolonged patency. Thus, collagen appropriately modified can provide a useful prosthesis in vascular reconstruction.

Aged↗
PubMed1980

Long-term function of NCGT vascular conduits in a multicenter trial: evaluation of physical chemical parameters.

Our experience with the NCGT graft has now encompassed 12 years in experimental animals and 4.5 years clinical experience with 134 grafts in man. It has previously been suggested that vessel wall structure, interface-charge, electric potential, and polarity of the blood intimal interface appear critical in the prevention of intravascular thrombosis in all vascular prosthetic bypass grafts. This concept has now been confirmed using ferritin, colloidal iron and fluorescamine intimal labelling. These provide a quantitative special characterization of the surface charges of several grafts, including the NCGT graft. Study indicates that each step in the production of the NCGT graft results in a cumulative increase in the structured negative charge of the vascular interface. The more dense the structured negative charge of the prosthesis, the more resistant is the graft to short and long-term thrombosis in experimental animals and man. The experience has been confirmed with a comparative analysis of implantation results in 105 patients up to 4.5 years with 65 to 70% patency rate over that time interval. Statistical analysis of parameters confirm again that the polarity and structure of the vascular interface is important in the effective function and patency rate of the grafts.

Animals↗
PubMed1978

The prevalence of hypertension in the Indian population of Durban.

In a random house-to-house study of 1 000 Indians the prevalence of essential hypertension according to the World Health Organization (WHO) criteria was 19% (females 22%; males 15%). The study revealed that the prevalence of hypertension was higher than in published data from India. Ethnicity in our study caused a significant variation in prevalence. Prevalence was lower than in our urban Zulu study. Blood pressure rose with age, but there was a greater rise in systolic than in diastolic blood pressure. Prevalence in males and females under 40 years were equal. There was an association between hypertension and diabetes mellitus. More effective screening and therapeutic programmes should be initiated in the Indian population because of the high prevalence of hypertension which may lead to complications if untreated, and because 58% of the hypertensive subjects were untreated or had discontinued therapy.

Adolescent↗
PubMed1977

Multiple fistulas between the coronary arteries and the left ventricle.

The authors report a case of fistulas connecting the anterior descending, circumflex, and dominant right coronary arteries with the left ventricle. Although fistulous connections between a coronary artery and a cardiac chamber have been described before, this is only the third known case in which all of the coronary arteries communicated with the left ventricle.

Coronary Vessels↗
PubMed1976

Radionuclide venography of the lower extremities and inferior vena cava by continuous injection and moving bed gamma camera technique.

Radionuclide venography has proved to be a tedious procedure because of the need for multiple imaging set-ups with coordinated, repeated injections of radionuclide. The use of a moving bed gamma camera has shortened the procedure. This method enables the entire sapheno-femoral-iliac-caval system to be visualized in continuity on a single film. The moving table top system also adequately imaged the suspected areas of thrombi or endothelial damage on the post-exercise study on a single film.

Humans↗
PubMed1976

Oxygen toxicity: augmentation of antioxidant defense mechanisms in rat lung.

In studies directed at determining the activities of selected enzymes in lung tissue after in vivo exposure to hyperoxia, 70-day-old rats were exposed to 85% or 90% O2 for 1-14 days. After 7 days of exposure to 90% O2 (1atm), superoxide dismutase activities in mitochondrial and cytosolic fractions increased, respectively, to 245 and 145% of control; glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase activities increased, respectively, to 317, 175, and 413% of control. The levels of reduced glutathione and total nonprotein sulfhydryl compounds were elevated to 195% and 365% of control. Similar changes were observed in rats exposed to 85% O2 for up to 14 days, but to a lesser degree. The changes are interpreted as a reflection of the overall magnitude of oxidant-induced lung injury-reparative processes. The results suggest that hyperoxia induces an increase in lung "antioxidant" defense capabilities. This apparent adaptive response may be important in decreasing the susceptibility of lung tissue to continued O2 toxicity.

Animals↗