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Biomedical subjects

S Balasundaram

Publications and source records attributed to S Balasundaram.

16 recordsLinked to original sources
PubMed2000

Detection of an Ehrlichia bovis-like organism in cultured buffalo monocytes.

Monocytes from a buffalo were cultured in RPMI 1640 medium following separation of plasma by the erythrocyte sedimentation technique and subsequent separation of mononuclear cells by density gradient centrifugation. Growth of an organism considered to be Ehrlichia bovis was noticed in the cultured monocytes after 10 days. The inclusions were considered to be those of E. bovis from their morphology, staining characteristics and growth characteristics in culture, and by indirect immunofluorescence examination with an anti-E. canis serum. The utility of peripheral blood monocyte cultures opens the possibility of diagnosing the carrier status of ehrlichiosis in animals.

Animals↗
PubMed1996

Morphology and staining characteristics of Ehrlichia bovis.

Morphology and staining characteristics of Ehrlichia bovis were observed after staining with Romanowsky and Gimenez stains and fluorochroming with acridine orange. Ehrlichia bovis could be identified as elementary bodies, initial bodies and morulae in the host cell cytoplasm. The inclusions were solid and compact and resembled more closely those of E. canis (canine monocytic ehrlichia) than E. phagocytophilia or E. ondiri (bovine granulocytic ehrlichiae). The organisms usually took acidophilic shades with Romanowsky stains. Apart from morulae, the other forms sometimes resembled azurophil granules. While Gimenez staining and fluorochroming by Anderson and Greiff technique gave poor results, the organism stained well on fluorochroming with Lauer's technique.

Animals↗
PubMed1995

Usefulness of rabbits and mice as experimental laboratory models for Ehrlichia bovis.

Attempts were made to infect mice and immunosuppressed rabbits with Ehrlichia bovis. While evidence of infection could be noticed in rabbits, their identity as E. bovis needs confirmation. Mice appeared to be infected and showed clear inclusions in both blood monocytes and peritoneal macrophages. While symptoms of disease were not observable in rabbits, alopecia, dullness and death were noticed among infected mice. It is concluded that mice are better laboratory models for E. bovis infection; also that infection in mice could be enhanced by immunosuppression.

Animals↗
PubMed1991

Leaflet embolisation from Duromedics valves: a report of two cases.

Embolization of parts of mechanical valves has been reported since the inception of prosthetic valve implantation. We report here two cases of embolization of one hemileaflet of a Duromedic bileaflet prosthesis in the mitral position due to a pivot fracture. Both presented with moderately severe mitral regurgitation and pulmonary edema and were successfully managed by replacement of the malfunctioning prostheses. The embolised disc was located in the left common iliac artery by abdominal ultrasound and removed by an inguinal, retroperitoneal approach with low morbidity. Both patients left hospital and are doing well to-date.

Adult↗
PubMed1991

A feasibility study of valve repair in rheumatic mitral regurgitation.

Valve repair is an established form of treatment for mitral valve regurgitation. In order to elucidate the feasibility and results of aggressive repair in a young rheumatic population, all consecutive patients operated on between July 1988 and July 1990 for mitral regurgitation were reviewed. There were 203 patients with a mean age of 29 years; 91% were in functional classes III-IV. Pure regurgitation was present in 47.8%. Associated valvular surgery was performed in 56.2%. Forty-nine (24.1%) patients had a straight valve replacement (MVR), 18 (8.9%) had an unsuccessful attempt at repair and in 136 (67%) the repair was considered successful. Overall hospital mortality was 3.4%: 4% for MVR, 16.6% for the attempts, 1.4% for repairs. The thromboembolic rate for replacement was 6.0% pt-yr and for repair 0.87% pt-yr. There were five late deaths in the replacement group and one in the repair group. Seventeen patients required reoperation in the repair group (12.6%) with a mean age of 17 years. Six of these patients had active rheumatic carditis, either at first operation or in the postoperative period. The postoperative functional status of all patients was excellent. In conclusion, valve repair although possible in a high percentage of rheumatic regurgitation patients carried a penalty of unsuccessful attempts and reoperations. However, in the follow-up period the rate of thromboembolism and late mortality among the patients with prostheses offsets these disadvantages.

Adolescent↗
PubMed1990

Haemodynamic effect of supraaortic ridge enhancement on the closure mechanism of the aortic valve and its implications in aortic valve repair.

The presence of the sinus of valsalva plays an essential part in the closing mechanism of the aortic valve. High-energy vortices are initiated at the upper limit of each sinus or supraaortic crest, and last during the whole valve closing time. An attempt was made to prove this hypothesis in vivo by intermittent augmentation of each supraaortic ridge. In a series of five dogs without cardiopulmonary bypass, pledgeted sutures were placed at the level of each crest and passed through tourniquets. In a series of three sheep, similar sutures were placed under direct vision with cardiopulmonary bypass. The supraaortic crests were augmented or maintained normal by tightening or loosening the tourniquets repeatedly. Simultaneous aortic and ventricular pressures and 2D- and M-mode echocardiography were recorded. In the dog series the results were unpredictable due to variability in the supraaortic crest enhancement because the sutures did not correspond to the anatomical crest. In the sheep series the sutures were correctly placed and M-mode echocardiography demonstrated a significant (p less than 0.01) shortening in systolic time. These results suggest the use of enhancement of the supraaortic crest as an adjunct technique in aortic valve repair.

Animals↗
PubMedDate not supplied

The problems of valve surgery in a developing country.

The management of young patients with valvular heart disease is a difficult problem in developing countries. At our Institution, 765 valves were operated upon in 523 patients over a period of two years. Rheumatic etiology was seen in 70% of the valves and 60% of all the valves were repaired. The hospital mortality and morbidity in the form of thromboembolic episodes were less in the repair group; 35 valves in 26 patients had to be reoperated upon for instability of the primary repair. Despite this high and early reoperation rate in the repair group and considering the higher mortality plus the problems of anticoagulation and limited durability of bioprostheses in the replacement group, conservation of the patient's own valve remains a better alternative in the long-term.

Adult↗
PubMedDate not supplied

Persistent left superior vena cava: a simple technique for adequate drainage during cardiopulmonary bypass.

Persistent left superior vena cava is a frequent anomaly of the systemic venous return and usually drains into the right atrium through the coronary sinus. Inadequate drainage of this vessel during cardiopulmonary bypass can result in complications for the patient and problems for the surgeon. Various methods of draining this vessel, directly or indirectly through the coronary sinus, have been already described. Some surgeons temporarily occlude or even ligate this vessel. We describe here an alternative and simple method to drain this vessel during cardiopulmonary bypass.

Cardiopulmonary Bypass↗
PubMedDate not supplied

Cardiopulmonary bypass in sickle cell anaemia. Report of five cases.

Five patients with sickle cell haemoglobinopathies underwent open heart surgery. At the start of the cardiopulmonary bypass the patient's circulating blood volume was separately drained into a bag, spun down and retransfused into the patient at the end of the operation. Moderate hypothermia, aortic cross clamping, topical hypothermia and cold crystalloid cardioplegia were used in all patients. None of the patients had transfusions in the postoperative period. No macroscopic or microscopic evidence of haemolysis were seen, nor haematuria or other clinical evidence of sickling. There was no evidence of wound infection and all were discharged home at a mean of 12.6 days. It is concluded that in cases of sickle cell anaemia exchange transfusion at the beginning of cardiopulmonary bypass followed by retransfusion of the red cell free blood can be used safely, permitting the performance of standard open heart procedures.

Adolescent↗