Correlation between 6-min walk test and exercise stress test in healthy children.

AIM: To investigate the correlation between 6-min walk test (SMWT) and incremental treadmill exercise stress test (EST) as indicators for the functional capacity in children. METHODS: Healthy children aged 9-12 years were included. The anthropometric data, SMWT and EST were prospectively measured using the standard protocols. Various parameters were analysed to define the correlation between SMWT and EST. RESULTS: A total of 100 subjects (53 boys) aged 10.3 +/- 1.0 years participated in the study. The SMWT distance was 586.1 +/- 44.0 m. Height (r = 0.59, R(2) = 35%), length of the leg (r = 0.64, R(2) = 41%), heart rate at the end of SMWT (r = 0.59, R(2) = 35%) and heart rate difference at the end of SMWT (r = 0.71, R(2) = 50%) were found to have significant correlation with SMWT distance. The estimated maximal oxygen consumption (eVO2) obtained during the EST tended to be greater in boys than in girls. Among the parameters obtained during EST, maximal heart rate (r = 0.33, R(2) = 11%) and the eVO2 (r = 0.54, R(2) = 53%) were found to have significant correlation with SMWT. CONCLUSIONS: SMWT distance is significantly correlated with the eVO2 obtained during the EST. This indicates that SMWT is also one of the predictive markers for EST performance.

Left main coronary occlusion from Takayasu arteritis in an 8-year-old child.

Takayasu's arteritis (TA) is a chronic systemic inflammatory disease that usually affects the aorta and its primary branches and occasionally the coronary arteries. We report the case of an 8-year-old girl who was presented with chest pain and was referred to our institution with the presumptive diagnosis of pneumonia and sepsis. Ultimately, the patient's chest pain was attributed to myocardial infarction secondary to coronary occlusion from TA. She underwent a successful stenting of the left main coronary artery with sirolimus-eluting stent. In a review of the literature, we discuss the demographic profile, clinical and radiographic findings, and available therapeutic options.

Beraprost therapy in children with pulmonary hypertension secondary to congenital heart disease.

We present a report on children with severe pulmonary hypertension secondary to congenital heart disease who received 6 months of beraprost therapy. The children had an increase in intracardiac left-to-right shunt and a reduction of the pulmonary-to-systemic vascular resistance ratio, whereas the pulmonary artery pressure was not significantly changed.

Inhibition of K(+) channel activity in human pulmonary artery smooth muscle cells by serum from patients with pulmonary hypertension secondary to congenital heart disease.

Activity of K(+) channels regulates cytosolic free Ca(2+) concentration by controlling membrane potential. A rise in cytosolic free Ca(2+) concentration in pulmonary artery smooth muscle cells (PASMC) triggers pulmonary vasoconstriction and stimulates PASMC proliferation. Whether serum from children with pulmonary hypertension (PH) secondary to congenital cardiopulmonary diseases contains a factor(s) that inhibits K(+) channel function in PASMC was investigated using patch clamp techniques. PASMC isolated from normal subjects were cultured in media containing 5% serum from normotensive (NPH) or PH patients. Cell growth rate and the currents through voltage-gated K(+) channels were determined and compared between the cells treated with serum from NPH and PH patients. In the absence of growth factors, incubation of PASMC in media containing NPH serum for 48 h increased cell numbers by 2.5-fold, whereas incubation of the cells in media containing PH serum increased cell numbers by 4.5-fold (p < 0.001). Amplitude of whole-cell voltage-gated K(+) currents in NPH serum-treated cells (1119 +/- 222 pA at +80 mV, n = 43) was 3.5-fold greater than in PH serum-treated cells (323 +/- 34 pA, n = 43, p < 0.001). Consistently, membrane potential was much more depolarized in PASMC treated with PH serum (-28 +/- 2 mV, n = 29) than cells treated with NPH-serum (-47 +/- 2 mV, n = 28; p < 0.001). These results suggest that a circulating mitogenic agonist, which induces membrane depolarization by inhibiting voltage-gated K(+) channel activity in PASMC, may be produced or up-regulated in pediatric patients with secondary PH.

Upregulated TRP and enhanced capacitative Ca(2+) entry in human pulmonary artery myocytes during proliferation.

A rise in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) due to Ca(2+) release from intracellular Ca(2+) stores and Ca(2+) influx through plasmalemmal Ca(2+) channels plays a critical role in mitogen-mediated cell growth. Depletion of intracellular Ca(2+) stores triggers capacitative Ca(2+) entry (CCE), a mechanism involved in maintaining Ca(2+) influx and refilling intracellular Ca(2+) stores. Transient receptor potential (TRP) genes have been demonstrated to encode the store-operated Ca(2+) channels that are activated by Ca(2+) store depletion. In this study, we examined whether CCE, activity of store-operated Ca(2+) channels, and human TRP1 (hTRP1) expression are essential in human pulmonary arterial smooth muscle cell (PASMC) proliferation. Chelation of extracellular Ca(2+) and depletion of intracellularly stored Ca(2+) inhibited PASMC growth in media containing serum and growth factors. Resting [Ca(2+)](cyt) as well as the increases in [Ca(2+)](cyt) due to Ca(2+) release and CCE were all significantly greater in proliferating PASMC than in growth-arrested cells. Consistently, whole cell inward currents activated by depletion of intracellular Ca(2+) stores and the mRNA level of hTRP1 were much greater in proliferating PASMC than in growth-arrested cells. These results suggest that elevated [Ca(2+)](cyt) and intracellularly stored [Ca(2+)] play an important role in pulmonary vascular smooth muscle cell growth. CCE, potentially via hTRP1-encoded Ca(2+)-permeable channels, may be an important mechanism required to maintain the elevated [Ca(2+)](cyt) and stored [Ca(2+)] in human PASMC during proliferation.

Sustained membrane depolarization and pulmonary artery smooth muscle cell proliferation.

Pulmonary vasoconstriction and vascular medial hypertrophy greatly contribute to the elevated pulmonary vascular resistance in patients with pulmonary hypertension. A rise in cytosolic free Ca(2+) ([Ca(2+)](cyt)) in pulmonary artery smooth muscle cells (PASMC) triggers vasoconstriction and stimulates cell growth. Membrane potential (E(m)) regulates [Ca(2+)](cyt) by governing Ca(2+) influx through voltage-dependent Ca(2+) channels. Thus intracellular Ca(2+) may serve as a shared signal transduction element that leads to pulmonary vasoconstriction and vascular remodeling. In PASMC, activity of voltage-gated K(+) (Kv) channels regulates resting E(m). In this study, we investigated whether changes of Kv currents [I(K(V))], E(m), and [Ca(2+)](cyt) affect cell growth by comparing these parameters in proliferating and growth-arrested PASMC. Serum deprivation induced growth arrest of PASMC, whereas chelation of extracellular Ca(2+) abolished PASMC growth. Resting [Ca(2+)](cyt) was significantly higher, and resting E(m) was more depolarized, in proliferating PASMC than in growth-arrested cells. Consistently, whole cell I(K(V)) was significantly attenuated in PASMC during proliferation. Furthermore, E(m) depolarization significantly increased resting [Ca(2+)](cyt) and augmented agonist-mediated rises in [Ca(2+)](cyt) in the absence of extracellular Ca(2+). These results demonstrate that reduced I(K(V)), depolarized E(m), and elevated [Ca(2+)](cyt) may play a critical role in stimulating PASMC proliferation. Pulmonary vascular medial hypertrophy in patients with pulmonary hypertension may be partly caused by a membrane depolarization-mediated increase in [Ca(2+)](cyt) in PASMC.

Wire-snare technique with distal flow control for coil occlusion of a modified Blalock-Taussig shunt.

Coil occlusion of Blalock-Taussig shunts has been associated with a high rate of device embolization. We describe a technique consisting of transvenous snaring and exteriorization of a guidewire advanced through a modified left Blalock-Taussig shunt, allowing distal shunt flow control and successful coil occlusion of the shunt. Cathet. Cardiovasc. Intervent. 49:51-54, 2000.

Spontaneous resolution of myelofibrosis and pancytopenia followed by the development of acute myeloid leukemia with an extramedullary mass.

PURPOSE: Spontaneous resolution of myelofibrosis is extremely rare. A patient with myelofibrosis and pancytopenia that spontaneously resolved with subsequent development of acute myelomonocytic leukemia and an extramedullary mass of the ovary is described. PATIENT AND METHODS: A 2-year-old girl had severe pancytopenia and myelofibrosis without signs of myeloid metaplasia. The patient was transfused with packed red blood cells and platelets and monitored. RESULTS: The pancytopenia and myelofibrosis resolved spontaneously within 1 month after initial presentation and her blood counts normalized. The patient developed a chloroma of the ovary and acute myelomonocytic leukemia 13 months later and eventually died from disease. CONCLUSIONS: This patient initially had acute myelofibrosis which was most likely secondary to occult acute myelomonocytic leukemia. The transfusions may have been a contributing factor in the spontaneous remission.

Safety and immunogenicity of REMUNE in HIV-infected Thai subjects.

The safety and immunogenicity of REMUNE, an HIV-specific immune based therapy for HIV infection, was evaluated in a cohort of 30 HIV infected subjects in Thailand. This therapy utilizes a gp120 depleted inactivated virus (HZ321), which exhibits a high degree of conservation with the core antigens of both type B' and E strains of HIV, the predominant Thailand isolates. The treatment was well tolerated, with no serious adverse events reported over the course of the 4-month trial. Treatment in which four doses were administered with REMUNE appeared to boost HIV-specific immune responses, with approximately 75% of the treated subjects demonstrating an increase in either the repertoire or the intensity of the serological response to HIV as measured by Western blot. CD4%, viral load, and weight remained stable over the course of the 4-month study relative to baseline values. Viral subtyping of this cohort revealed a predominance of type 'E'. These data suggest that REMUNE is safe and immunogenic in seropositive Thai subjects and supports further study of the therapeutic potential of REMUNE to treat HIV-1 infection.

Factors affecting patients' acceptance of H.I.V. infections.

A study on patients' acceptance of the diagnosis of HIV infection was done in 36 patients at Ramathibodi Hospital. Patients were interviewed based on the data in a questionnaire. Over one half of the patients were 21-40 years old. Eighteen patients were prostitutes. The stages of the infection were: AIDS in 1, AIDS-related complex in 9 and asymptomatic in 26 cases. The rate of acceptance of having the infection did not differ regarding age, education, income, risk factors in acquiring the infection, and the stage of the disease. However, all patients who had worked in a foreign country did not accept the diagnosis while all who had never worked abroad did. Patients whose family knew that they had the infection accepted the diagnosis better than those whose family did not know. It is concluded that a substantial portion of patients did not accept that they had HIV infection. Counselling must be appropriately applied to each individual.

HIV seroconversion in Thai hemophiliacs up to 1991.

In Thailand, the anti-HIV screening in the donor blood was started in 1987 and was compulsory nationwide in February 1989. Sixty-six hemophilia A and 10 hemophilia B patients who received approximately six million units of factor VIII and IX in the form of fresh frozen plasma, frozen cryoprecipitate, cryoprecipitate removed plasma, fresh dry plasma and factor concentrate during 1976 to 1991 were tested for anti-HIV since 1987. The age ranged from 1-39 year (mean +/- SD = 15 +/- 7.3). The anti-HIV test was performed by ELISA and/or gel agglutination and confirmed by Western blot analysis. The patients would be checked 1-2 times per year and as necessary. A total of 174 tests for the first, second, third, fourth, fifth and sixth tests were studied in 76, 49, 27, 14, 5 and 3 patients respectively during 1987 to 1991. The prevalence of HIV seroconversion in the year 1987, 1988, 1989, 1990 and 1991 was 2.2% (1/45), 1.9% (1/53), 1.6% (1/63), 1.5% (1/67) and 3.9% (3/76) respectively. Three HIV seroconversion were found in the first, fourth and fifth anti-HIV test in 3 hemophilia A patients who received massive infusion of blood components during orthopedic corrective surgery. One case of HIV seroconversion found in 1987 was transmitted by HIV unscreened blood while 2 cases in 1991 by anti-HIV seronegative blood whose donors were in the window period of HIV infection. The prevalence of HIV seroconversion in Thai hemophiliacs is much lower than those in western countries.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B vaccination in Ramathibodi health personnel 1986-1987.

Hevac-B-Pasteur 5 mcg, H-B-Vax I 20 mcg, and Engerix B 20 mcg, were given to 23, 34, 15 health personnel in Ramathibodi hospital. The seroconversion rate for Pasteur vaccine was 85 per cent compared to 95 per cent for the other two groups. Adverse reactions were few and transient.

Prevalence of chlamydial infection in patients with gonococcal urethritis.

Using a fluorescein labelled monoclonal antibody ("Microtrak") to identify Chalmydia elementary bodies in urethral smears, we detected Chlamydia trachomatis in 32 (26.67%) of 120 male patients after treatment of their gonococcal urethritis. Sixteen of these 32 patients (50%) had normal urethral smear. Only 16 (50%) of the patients yielding chlamydia would have received treatment in the absence of diagnostic service for chlamydial infection.

Prevalence, detection and control of hypertension in Thai population of a central rural community.

Epidemiolagical survey of hypertension was carried out on 2,374 villagers, aged 15 years and above, residing in Bang-Pa-in district, Ayutthaya province. The overall prevalence of hypertension was 11.3 per cent. The prevalence rate of pure systolic hypertension rose with age up to elderly; whereas the prevalence rate of diastolic hypertension increased with age up to late middle age, then declined in the elderly. Regarding the detection of hypertension, only 41.6 per cent of the cases were previously detected. And only 30.1 per cent of the cases were under current treatment. Females had a greater proportion of previously detected and currently treated cases than males. Among those currently treated hypertensive patients, 50.5 per cent went to see a physician, 29.5 per cent went to the local health centers; the rest sought the services of local quacks, traditional healers and drug stores. It yielded only 24.7 per cent of the treated cases whose BP were under control. Since the people prefer seeking help from local personnel, the role of community health personnel should be strengthened to bring more effective control of the disease.

Acquired immune deficiency syndrome in Thailand. A report of two cases.

PIP: As a major tourist attraction for heterosexuals and homosexuals, Thailand stands to experience major increases in the rate of acquired immunodeficiency syndrome (AIDS). This article describes 2 AIDS cases in Thailand, including the 1st documented case. The 1st case involved a 28-year-old unmarried Thai male who travelled to the US in 1981 for postgraduate work and had contact with both female prostitutes and homosexual men. In 1982-83, the patient demonstrated fever, fatigue, meningitis, and finally Pneumocystis carinii. He was hospitalized in 1984 for fever, bilateral deafness, and diarrhea. Serologic analysis revealed antibodies to human T-cell lymphotropic virus type III (HTLV- III). Death occurred in January 1985. The 2nd patient was a 52-year- old single man who had moved from West Germany to Thailand 10 years previously to admission in 1985 for upper gastrointestinal bleeding. The patient, a homosexual, make frequent visits to Germany and was an alcoholic. The initial clinical diagnosis was ruptured esophageal varices with cirrhosis. The patient further had a history of herpes simplex genitalis. The subsequent course of the disease process included massive blood loss and interstitial pneumonitis. Serology revealed antibodies to HTLV-III. Death occurred in August 1985. Both of these patients belonged to groups at high risk of AIDS and had clinical, serologic, and immunologic indicators that enabled confirmation of the AIDS diagnosis.^ieng