Heart transplantation 1987--2007: 20 years' experience at Chulalongkorn hospital.

OBJECTIVE: After many years, heart transplantation is still the most accepted treatment for end-stage heart disease. A heart transplantation program was started at our hospital in December 1987 as the first intrathoracic organ transplantation in Southeast Asia. Herein, we have reviewed our 20 years of experience from 1987 to 2007. METHODS: We followed every individual within our 52-patient cohort for up to 20 years. Three eras were studied: 1987 to 1995, 1996 to 2002, and 2003 to 2007. End points were survival, rejection, infection event, and graft coronary artery disease (CAD). RESULTS: There were 52 patients (39 males and 12 females). The mean age was 41.7 years (range, 12-23 years). Perioperative mortality (within 1 month) was 13.4% (n = 7) due to graft failure (n = 2), rejection (n = 3), infection (n = 1), on pulmonary hypertension (n = 1). Medium-term mortality (1-12 months) was 30.7% (n = 16) due to rejection (n = 8), infection (n = 7), or CAD (n = 1). After 1 year causes of death were rejection (n = 4), infection (n = 4), renal failure (n = 2), or CAD (n = 1). Overall actuarial 1-, 5-, and 10-year survival rates for all recipients were 54.7%, 43.3%, and 32.5%, respectively. The first patient in this series is still alive. For the period 2003 to 2007, actuarial 1-year and 4-year survival rates for all recipients were both 77.8%. The rate of rejection was reduced to just one event during this period. All surviving patients were NYHA Functional class I and II; 86% went back to work, leading almost normal lives. CONCLUSION: Improved survival in the current era may be attributed to better organ preservation, improved immunosuppression, and control of infection, as well as less graft CAD. Those who survive more than 1 year have a good quality of life.

Oxidation of hydrogen sulfide by flocculated Thiobaccillus denitrificans in a continuous culture.

In a continuous fermentation, significant advantages may be gained by immobilization of microbial cells. Immobilization allows cells to be retained in the fermenter or to be readily recovered and recycled. Therefore, the hydraulic retention time and the biomass retention time are decoupled. A novel cell immobilization has been developed for the immobilization of autotrophic bacteria by coculture with floc-forming heterotrophic bacteria with growth of the latter limited by the availability of organic carbon. The result is an immobilization matrix which grows along with the immobilized autotroph. We have previously demonstrated the utility of this approach by immobilizing the chemoautotroph Thiobacillus denitrificans in macroscopic floc by coculture with floc-forming heterotrophs from an activated sludge treatment facility. Floc with excellent settling characteristics were produced. These floc have now been used to remove H(2)S from a gas stream bubbled through continuous cultures. The stoichiometry and kinetics of H(2)S oxidation by immobilized T. denitrificans were comparable to that reported previously for free-cell cultures. Oxygen uptake measurements indicated the growth of both T. denitrificans and the heterotrophs although the medium contained no added organic carbon. Continuous cultures with total biomass recycle were maintained for up to four months indicating the long-term stability of the commensal relationship between the immobilized autotroph and the heterotrophs which composed the immobilization matrix. It was observed that at any given H(2)S loading the biomass concentration reached a maximum and leveled out. The ultimate biomass concentration was dependent upon the H(2)S feed rate.

Six years clinical experience with dura mater cardiac valves.

Homologous dura mater bioprostheses have been used for over 6 years in 217 patients who hae undergone cardiac valve replacement at Chulalongkorn Hospital and Medical School, Bangkok. The mitral valves were replaced in 151 patients (69.6%), aortic valve replacements were performed in 29 patients (13.7%), and multiple valve replacement were performed in 37 patients (16.7%). This study will be confined mainly to the isolated mitral and aortic valve replacements. The early deaths in the mitral replacement series was 10.5%, and 13.8% in the aortic valve replacement. Myocardial (pump) failure was the cause of early death in the majority of cases. The late mortality was 7.3% in the mitral position and 12.0% in the aortic position. The mean improvement of NYHA class was from 3.76 to 1.13 in the mitral series, and from 3.64 to 1.32 in the aortic group. The actuarial survival rates at 6 years after operation were 87% and 84% respectively and compare favorably with several prostheses currently in use. There was no case of thromboembolism even though no anticoagulants were used.

An open study of acebutolol, given as a single daily dose in the management of hypertension in the Chulalungkorn Hospital, Thailand.

In an open study of fifteen patients with essential hypertension, acebutolol, a cardioselective B 1-adrenoceptor antagonist given orally once daily at dosages of between 400 mg and 1200 mg, produced a substantial and progressive reduction in systolic and diastolic arterial pressure and in the tension time index both in the lying and standing position over the 3 months of the trial. The changes from pre-trial values of blood pressure assessments were statistically significant (p less than 0.001). No side-effects were reported and laboratory monitoring of biological parameters revealed no untoward effects of treatment.