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Biomedical subjects

Pat Mahachoklertwattana

Publications and source records attributed to Pat Mahachoklertwattana.

12 recordsLinked to original sources
PubMed2006

Association between bone mineral density and erythropoiesis in Thai children and adolescents with thalassemia syndromes.

Increased marrow erythropoiesis in patients with thalassemia syndromes results in the expansion of bone marrow cavities and consequently decreases bone tissues, leading to osteoporosis. Whether the soluble transferrin receptor (sTfR), a marker of erythropoietic activity, correlates with the bone mineral density (BMD) in thalassemic patients has not previously been addressed. Forty-six children and adolescents with thalassemia syndromes, who were either not transfused or suboptimally transfused, were studied. BMD was determined by dual-energy X-ray absorptiometry. Blood samples were obtained in order to determine sTfR and hemoglobin. The patients were categorized into four groups: 1, beta-thalassemia/hemoglobin E (beta-thal/E) with transfusion-dependency (TD) (n = 18); 2, beta-thal/E with transfusion-independency (TI) (n = 15); 3, beta-thalassemia major (beta-major) (n = 6); 4, hemoglobin H (HbH) (n = 7). All patients had normal serum free thyroxine (FT4) and thyroid-stimulating hormone (TSH), and intact parathyroid hormone (PTH), serum calcium (Ca), phosphate (P), and 25-OH-vitamin D levels. The BMD of patients in the beta-major and beta-thal/E with TD groups were not significantly different. In comparison with the beta-major and beta-thal/E with TD groups, the beta-thal/E with TI and HbH groups had significantly higher BMD of the total body (TB), femoral neck (FN), and lumbar spine (LS), as well as higher levels of hemoglobin. In contrast, the sTfR levels of the beta-major, beta-thal/E with TI, and HbH groups were significantly lower than those of the beta-thal/E with TD group. The BMD of TB, FN, and LS was negatively correlated with the sTfR level, but positively correlated with the hemoglobin level. In conclusion, increased marrow erythropoiesis is one of the major determinants of reduced bone mass in thalassemic patients with either no transfusion or suboptimal transfusion.

Adolescent↗
PubMed2005

Biochemical markers of bone formation in Thai children and adolescents.

The measurement of biochemical markers of bone turnover is essential in the study of skeletal metabolism in health and diseases. Due to variations in the rate of bone growth in different age groups and possible ethnic differences, age-specific reference ranges for biochemical markers should be established in a particular pediatric population. In this study, biochemical markers of bone formation, bone-specific alkaline phosphatase (BAP), and osteocalcin (OC) in healthy Thai children and adolescents aged 9 to 18 years were evaluated in relation to their ages and pubertal development. Serum BAP levels in boys increased with age and peaked at about 12 to 13 years. In contrast, there was a progressive decline of serum BAP levels with advancing age in girls older than 9 years. Serum OC also increased with age and reached a peak at ages 12 and 13 years in girls and boys, respectively. In addition, both serum BAP and OC levels also varied with pubertal stages. The BAP levels in boys increased sharply at pubertal stage 3 and decreased at pubertal stage 5. In girls, the BAP levels showed a fairly constant high level up to stage 3, followed by a remarkable decrease thereafter. The OC levels in boys increased sharply at pubertal stage 4 and decreased thereafter. In girls, OC started to increase at pubertal stage 3 with no subsequent changes. The levels of serum BAP and OC were higher in boys than in girls at pubertal stages 3 to 5 and at stages 2, 4, and 5, respectively. Moreover, only serum BAP level showed significant positive correlation with height velocity in both genders. In multiple regression analyses, gender, age, and pubertal stage were consistently correlated with both serum BAP and OC levels. In summary, male and female adolescents have different patterns of changes in biochemical markers of bone formation.

Adolescent↗
PubMed2005

Exogenous subclinical hyperthyroidism during adolescence: effect on peak bone mass.

BACKGROUND: Chronic subclinical hyperthyroidism induced by suppressive doses of L-thyroxine (L-T4) therapy, so-called exogenous subclinical hyperthyroidism, may cause diminished bone mass in postmenopausal women. The effect of subclinical hyperthyroidism during childhood and adolescence on peak bone mass, however, has not been evaluated. OBJECTIVE: To determine whether exogenous subclinical hyperthyroidism during adolescence, the period of critical bone mass acquisition, would reduce peak bone mass. PATIENTS AND METHODS: Eighteen female adolescents and young adults with Hashimoto's thyroiditis and euthyroid goiter (aged 22.4 +/- 4.4 years) who had been treated with suppressive doses of L-T4, 127.5 +/- 23.7 microg/day, during adolescence (age at onset of subclinical hyperthyroidism, 14.2 +/- 1.5 years) for 6.3 +/- 3.4 years were enrolled in the study. Twenty-nine healthy female volunteers matched for age, weight, height and body mass index served as the controls. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. RESULTS: BMD of the lumbar spine, radius, Ward's triangle and total body were comparable in the two groups. In contrast, BMD of the femoral neck, trochanter and shaft of patients was slightly higher than those of controls. There were no correlations between BMD values and clinical parameters. CONCLUSION: Exogenous subclinical hyperthyroidism during adolescence has no demonstrable detrimental effect on peak bone mass attainment.

Adolescent↗
PubMed2004

Suppression of adrenal function in children with acute lymphoblastic leukemia following induction therapy with corticosteroid and other cytotoxic agents.

OBJECTIVE: To evaluate adrenal function in children with acute lymphoblastic leukemia (ALL) after induction therapy with corticosteroid and other cytotoxic agents. Study design Children with ALL (N=24) were treated with prednisolone (40 mg/m(2) per day) for 28 days during the induction phase followed by 1 week of oral dexamethasone every 4 weeks. A low-dose (1 microg) adrenocorticotropin (ACTH) test was performed 2 weeks after discontinuation of prednisolone; it was repeated 2 weeks later and then every 4 weeks in patients with adrenal suppression until normal response was achieved. RESULTS: Adrenal suppression was found in 46% of patients at 2 weeks after discontinuation of prednisolone; it persisted in 38%, 29%, and 13% of patients through 4 weeks, 8 weeks, and 20 weeks, respectively. Adrenal suppression appeared to last significantly longer in children aged >or=5 years than in children aged <5 years. Four children developed febrile neutropenia; all belonged to the adrenal suppressed group and were unable to mount an adequate adrenal response to the stress. CONCLUSIONS: About 50% of children with ALL developed adrenal suppression 2 weeks after a 4-week induction therapy with prednisolone. The suppression could persist through 20 weeks and may hinder an adequate adrenal response during acute febrile illness.

Adolescent↗
PubMed2003

Bone mineral density, biochemical and hormonal profiles in suboptimally treated children and adolescents with beta-thalassaemia disease.

OBJECTIVE: Thalassaemia/haemoglobinopathy is a hereditary disease causing increased erythropoiesis and expansion of the bone marrow cavity. As a consequence, there is a reduction in trabecular bone tissue resulting in osteopenia/osteoporosis. The present study was performed to assess bone mineral density (BMD) in children and adolescents with beta-thalassaemia disease and to determine biochemical and hormonal changes that may affect BMD. METHODS: Forty-eight children and adolescents with beta-thalassaemia were divided into two groups, transfusion-dependent (TD) (n = 16) and transfusion-independent (TI) (n = 32). All patients were treated suboptimally. BMD was determined by dual-energy X-ray absorptiometry. Bone maturation was assessed by radiographic bone age (BA). Blood and urine samples were obtained for the determination of biochemical and hormonal profiles, which included PTH, 25-hydroxyvitamin D (25-OHD), osteocalcin, bone-specific alkaline phosphatase, IGF-1, fT4, TSH and urine deoxypyridinoline. RESULTS: Most of the patients were short and underweight, and they had delayed BA with mean Z-scores of -2.77 in the TD and -2.04 in TI groups. The mean Z-scores of BMD in the TD vs. TI groups of total body, radius, femoral neck and lumbar spine were -2.09 vs.-1.49, -0.73 vs. -0.54, -1.93 vs.-1.17 and -3.45 vs.-2.43, respectively. Although the means BMD values in the TD group were lower than those in the TI group, they were not significantly different. Mean serum IGF-1 levels were lower in the TD than the TI groups, 11.6 and 24.9 nmol/l, respectively (P < 0.05). Other biochemical and hormonal profiles did not differ between these two groups. CONCLUSIONS: Patients with undertransfused severe beta-thalassaemia had more bone marrow expansion, lower serum IGF-1 levels and more delayed bone age than did patients with untransfused moderately severe beta-thalassaemia. Therefore, the severity of the disease appeared to be a primary factor for low bone mineral density in undertransfused patients in association with bone age delay and low serum IGF-1.

25-Hydroxyvitamin D 2↗
PubMed2003

Bone histomorphometry in children and adolescents with beta-thalassemia disease: iron-associated focal osteomalacia.

Thalassemia/hemoglobinopathy is a hereditary disease that causes chronic anemia and increased erythropoiesis. Consequently, an expansion of bone marrow spaces may contribute to osteopenia/osteoporosis. However, the pathogenesis of bone changes is not yet known. We, therefore, carried out the study on bone histomorphometry and biochemical and hormonal profiles in children and adolescents with suboptimally treated beta-thalassemia disease with the hope of gaining some new insight into the cellular and structural alterations of thalassemic bone. Seventeen patients underwent iliac crest bone biopsy for histomorphometric analyses. Bone mineral density (BMD) measurements were performed by dual energy x-ray absorptiometry. Most patients had growth retardation and delayed bone age. BMD was low especially at the lumbar spine. Serum IGF-I levels were almost always low. Bone histomorphometry revealed increased osteoid thickness, osteoid maturation time, and mineralization lag time, which indicate impaired bone matrix maturation and defective mineralization. In addition, iron deposits appeared along mineralization fronts and osteoid surfaces. Moreover, focal thickened osteoid seams were found together with focal iron deposits. Dynamic bone formation study revealed reduced bone formation rate. These findings indicate that delayed bone maturation and focal osteomalacia are the pathogenesis of bone disease in suboptimally blood-transfused thalassemics with iron overload. Iron deposits in bone and low circulating IGF-I levels may partly contribute to the above findings.

Adipose Tissue↗
PubMed2002

Accuracy of glucose meters in measuring low blood glucose levels.

BACKGROUND: Hypoglycemia is an emergency condition requiring treatment as soon as possible. Therefore, rapid and reliable blood glucose measurements are necessary. There are 2 systems of glucose meters (GMs), the reflectance photometer system (RPS) and the electrochemical biosensor system (BSS). GMs are widely used in monitoring blood glucose (BG) in patients with diabetes. BG values measured by GMs have been confirmed to be accurate especially in measuring normal and high BG levels. However, the data on the accuracy of GMs in measuring low BG levels are limited. OBJECTIVE: To compare accuracy and reliability of different systems of GMs in the measurement of low BG values. PATIENTS AND METHOD: Venous and capillary whole blood specimens were collected from patients who were investigated for pituitary dysfunction. The patients underwent an insulin-induced hypoglycemia test by intravenously administering human regular insulin. The low BG level was defined as having venous plasma glucose (PG) of less than 60 mg/dl (mean +/- SD = 36.59 +/- 9.19, n = 54). Capillary blood samples were obtained from fingertips. Venous BG (vBG) and capillary BG (cBG) were measured by GMs. Venous PG which considered a reference value was measured by the glucose dehydrogenase method. RESULTS: The correlation coefficient (r) between vBG measured by GMs-RPS and PG was 0.86 (p < 0.001), whereas, that between vBG by GMs-BSS and PG was 0.75 (p < 0.001). Similarly, the r between cBG by GMs-RPS and PG was 0.73 (p < 0.001), whereas, that between cBG by GMs-BSS and PG was 0.69 (p < 0.001). The mean difference between vBG by GMs-RPS and PG values was 0.01 +/- 4.90 mg/dl, whereas, that between vBG by GMs-BSS and PG values was 10.50 +/- 7.07 mg/dl which was significantly greater than the former (p<0.001). Moreover, the mean difference between cBG by GMs-RPS and PG values was 14.45 +/- 8.76 mg/dl, whereas, that between cBG by GMs-BSS and PG values was 23.87 +/- 9.48 mg/dl which was also significantly greater than the former (p < 0.001). These results demonstrated that vBG measured by GMs-RPS was comparable to PG values. In addition, cBG values by GMs-RPS and GMs-BSS were approximately 14 mg/dl or 38 per cent and 24 mg/dl or 65 per cent greater than PG values, respectively. CONCLUSION: In measuring low blood glucose levels, glucose meters using the reflectance photometer system are more accurate than those using the electrochemical biosensor system.

Blood Glucose↗
PubMed2002

Earlier onset of pubertal maturation in Thai girls.

BACKGROUND: Recent studies in the USA and Hong Kong demonstrated the onset of puberty in girls has shifted toward a younger age. Based upon previous studies on variations of pubertal maturation in Thai girls, the secular trend has also moved toward an earlier age. The latest study in 1995 revealed the mean age of menarche was 12.3 years. OBJECTIVES: To identify the onset of puberty, menarche and pubarche in female children and adolescents in 2 Bangkok schools. METHOD: Three hundred school girls aged 9-19 years were enrolled in the study. Data were collected from January 1997 through December 1999. Assessment of pubertal staging by Tanner's criteria was performed by a trained pediatrician. All were in good physical health and had normal height and weight. The median ages of thelarche, menarche and pubarche were estimated by probit analysis. All other parameters were expressed as mean +/- SD. RESULTS: The median ages of thelarche and pubarche were 9.4 and 11.1 years, respectively. Two hundred and twenty one girls had experienced menstruation. The median age of menarche was 11.2 years, whereas, the mean age was 12.1 years. Most girls reached near final adult height after 14 years old. CONCLUSION: The secular trend in decline of the ages of thelarche (or puberty) and menarche was observed in Bangkok girls. Further study in a larger population including a younger age group is required to define the current reference interval of onset of puberty.

Adolescent↗
PubMed2002

Antineutrophilic cytoplasmic antibody-positive systemic vasculitis associated with propylthiouracil therapy: report of 2 children with Graves' disease.

Systemic vasculitis is a rare complication of therapy with antithyroid medication. Antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis has been described in patients treated with propylthiouracil (PTU) and methimazole (MMI). The majority of cases have underlying Graves' disease. The authors report 2 children who developed ANCA-associated systemic vasculitis during PTU therapy of Graves' disease. One patient, after PTU treatment for 3 years, developed severe systemic vasculitis. After 3 weeks of arthritis, she abruptly presented with hematuria, proteinuria and edema concomitant with anemia. Her serum creatinine was elevated, to 6 mg/dl. Renal biopsy revealed crescentic glomerulonephritis. After admission, she developed intracerebral hemorrhage and pulmonary hemorrhage. She had positive perinuclear-ANCA (p-ANCA) with a titer of 1:160. Despite intensive therapy with immunosuppressive agents and plasmapheresis, as well as discontinuation of PTU, she died of the complications of severe systemic vasculitis. The other patient developed fever, arthralgia and leukocytoclastic vasculitis of the skin during treatment with PTU for about 2 years. Her symptoms and skin lesions disappeared after discontinuation of PTU. However, she has had a persistently high titer of p-ANCA 1:320 through 17 months follow-up time. Thus, patients who are treated with PTU can develop ANCA-positive vasculitis in a mild or severe form. Therefore, they should be carefully followed and monitored, not only for their thyroid status but also the serious complications of PTU.

Antibodies, Antineutrophil Cytoplasmic↗
PubMedDate not supplied

Bone mineral density in children and young adults with beta-thalassemia trait.

BACKGROUND: Homozygous beta-thalassemia is a hereditary hematological disease due to defective beta-globin synthesis. Consequently, there is ineffective erythropoiesis and increased peripheral hemolysis. Increased erythropoiesis in bone marrow results in expansion of marrow cavity and reduced bone mass. Patients with heterozygous beta-thalassemia or beta-thalassemia trait may have mild anemia, and consequently mildly increased erythropoiesis. Whether modestly increased erythropoiesis might decrease bone mass is not well established. OBJECTIVE: To evaluate bone mineral density (BMD) in children and young adults with beta-thalassemia trait. METHODS: Thirty-one healthy young adults aged 20-45 yr and 26 healthy children aged 8-15 yr with beta-thalassemia trait were enrolled in the study. BMD was determined by dual X-ray absorptiometry (DEXA). Determinations of intact parathormone (PTH), 25-hydroxyvitamin D (25-OHD), and bone markers were performed. RESULTS: In adults, all had z-scores of BMD more than -2 above the mean. The mean z-scores of BMD of lumbar spine, radius and femoral neck were 0.11, -0.10 and 0.41, respectively. In children, only two of 26 had z-scores of lumbar spine BMD more than -2 below the mean. The mean z-scores of BMD of total body, lumbar spine, radius and femoral neck were 0.12, -0.28, 0.30 and -0.14, respectively. All subjects had normal PTH, 25-OHD and bone markers levels. CONCLUSION: beta-Thalassemia trait is not a contributing factor for osteopenia/osteoporosis in children and young adults.

Adolescent↗