Effect of artesunate and mefloquine in combination on the Fridericia corrected QT intervals in Plasmodium falciparum infected adults from Thailand

OBJECTIVE

To ascertain whether mefloquine (MQ) produces electrocardiogram (ECG) changes that could be a risk for Torsades de Pointe (TdP), a potentially malignant, ventricular tachyarrhythmia.

METHODS

We measured the Fridericia corrected QT (QTcF) intervals on 12 lead ECGs on days (D) 0, 3, 7 in Plasmodium falciparum infected adults, treated with oral artesunate (AS) and MQ as a new fixed dose (n = 25) combination or loose tablets (n = 25) over 3 days. Target total doses were 12 mg/kg of AS and 24-25 mg/kg of MQ. MQ concentrations ([MQ]) were measured by HPLC.

RESULTS

All ECG intervals were similar between drug arms and were combined for analysis. Mean QTcF values were 389 (D0), 407 (D3) and 399 (D7) ms (Ps < 0.003 vs. D0); corresponding heart rates and [MQ]s were 83, 67 and 73 beats/minute (Ps ≤ 0.0003 vs. D0) and 0, 3095 and 1721 ng/ml. One male patient (loose arm) had a D3 QTcF 504 ms (D0 406 ms, D7 433 ms). In the modelling of QTcF and JTcF from D0 to D7, significant effects were observed individually for [MQ], temperature and heart rate (HR). The MQ AUC(0-∞) was not a significant factor. Using a manual descending, model building approach to select variables, the HR was the only significant variable (P = 0.001) over time in the model that best explained the changes in the QTcF and JTcF intervals.

CONCLUSIONS

In this small group of patients, slowing heart rates due to malaria resolution best explained the observed increases in the QTcF intervals.

The relationship between serum concentration of cardiac troponin I in chronic renal failure patients and cardiovascular events

OBJECTIVE

The purpose of this study was to evaluate the relationship between serum cardiac troponin I in asymptomatic chronic renal failure patients and cardiovascular events.

BACKGROUND

Short-term follow-up studies on this subject produced conflicting results.

MATERIAL AND METHOD

A total of 63 asymptomatic patients with chronic renal failure (CRF) with regular hemodialysis were followed for 18 months for cardiac mortality, myocardial infarction events and interventional procedures such as percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG). Serum cTnI and other blood chemistries were measured at the time of the study.

RESULTS

Forty seven chronic dialysis patients (75%) had an elevated level of cTnI concentration more than the 0.08 ng/ml cutoff but only fourteen patients (22%) had and elevated cTnI concentration of more than the AMI cutoff (0.4ng/ml). When using the 0.08 ng/ml cutoff, the NT-proBNP concentrations of the elevated groups were significantly higher than the normal groups. The authors also found that the elevated groups above the AMI cutoff had significantly higher cardiovascular events.

CONCLUSION

Elevated cTnI concentrations are commonly found in chronic renal failure patients. The AMI cutoff level of cTnI (0.4 ng/ml) seem to have a benefit for predicting the cardiovascular events in asymptomatic chronic renal failure patients while the 0.08 ng/ml cutoff doesn't have usefulness for this purpose. Further studies are needed to clarify this hypothesis.

An open, randomized trial of three-day treatment with artesunate combined with a standard dose of mefloquine divided over either two or three days, for acute, uncomplicated falciparum malaria

The combination of artesunate and mefloquine is currently one of the most effective treatments for multidrug-resistant Plasmodium falciparum malaria. Simultaneous, rather than sequential treatment with the two drugs, would allow better patient compliance. We therefore evaluated three-day treatment with artesunate combined with either 2 or 3 days of mefloquine co-administered once a day with artesunate. The study was an open, randomized trial for acute, uncomplicated falciparum malaria and was conducted at the Bangkok Hospital for Tropical Diseases. One hundred and twenty adult patients were randomized to two treatment groups. Group 1 patients received 4 mg/kg/day of artesunate for 3 days and 3 daily doses of 8.0 mg/kg/day mefloquine given with artesunate. Group 2 patients received the same dose of artesunate and the same total dose of mefloquine (25 mg/kg). However, the mefloquine was given as 15 mg/kg on the first day and 10 mg/kg/ on the second day, again with artesunate. The baseline demographic and clinical characteristics of the patients in the two groups were similar. The cure rates for the 3-day and 2-day mefloquine regimens were 100% and 99%, respectively. There were no significant differences in either median fever clearance times (group 1=32 hours; group 2=33 hours) or mean parasite clearance times (group 1=42.3 hours; group 2=43.3 hours). Both regimens were well tolerated and there were no significant differences in the incidence of adverse effects. Nausea or vomiting occurred in 3.8% of patients in both groups and transient dizziness occurred in 4% of group 1 and 9% of group 2 patients. These results suggest that a 3-day regimen of mefloquine administered with artesunate is effective and well tolerated. This practical regimen could improve patient compliance.

Cardiac troponin T: its role in the diagnosis of clinically suspected acute myocarditis and chronic dilated cardiomyopathy in children

This study was conducted to assess the use of the serum cardiac troponin T (cTnT) level as a noninvasive indicator to differentiate acute myocarditis and chronic dilated cardiomyopathy in pediatric patients. Myocarditis and dilated cardiomyopathy are clinically difficult to differentiate. Endomyocardial biopsy proved to be quite useful. However, the nature of the procedure--invasiveness, time-consuming, and limited sensitivity--caused some concerns, especially in pediatric patients. Hence, we attempted to find an alternative method that could give a prompt diagnosis of acute myocarditis. Twenty cases with clinically suspected myocarditis or dilated cardiomyopathy and a control group of 21 cases with moderate left-to-right shunt and congestive heart failure were recruited. History, physical examination, electrocardiogram, chest roentgenogram, echocardiogram, cTnT, creatine kinase MB isoenzyme (CK-MB mass), and/or endomyocardial biopsy were compared. The gold standard used to diagnose myocarditis is endomyocardial biopsy (Dallas criteria) and/or recovery from cardiovascular problems within 6 months of follow-up. Ten patients were diagnosed as having myocarditis (group 1) and 10 with chronic dilated cardiomyopathy (group 2). The control group of 21 cases was designated as group 3. The median serum cTnT levels were 0.088 (0.04-3.11), 0.010 (0.010-0.990), and 0.010 (0.010-0.550) ng/ml in groups 1, 2, and 3, respectively. The mean CK-MB mass level for groups, 1, 2, and 3 were 18.35 (7.14-70.00), 4.80 (0.54-108.00), and 2.26 (0.95-7.06) ng/ml. The study showed that both the cTnT and CK-MB mass levels were significantly higher in group 1 than either group 2 or group 3. Histopathology was studied in 9 cases. In 2 of 5 cases and in all 4 cases in group 1 and group 2 histopathology was pathologically proved. Levels of cTnT and CK-MB were significantly higher for myocarditis than for dilated cardiomyopathy and left-to-right shunt with CHF. Further study is needed to assess the optimum cTnT level for differentiating both conditions.

Homozygous DNA variants in exon 9 of the LDL receptor gene in a Thai patient with primary hypercholesterolemia phenotype

Mutation in low density lipoprotein (LDL) receptor gene causes an inherited primary hypercholesterolemia namely familial hypercholesterolemia (FH). In this study, 46 Thai patients with primary hypercholesterolemia were screened for mutations in exon 9 of the LDL receptor gene by polymerase chain reaction-restriction fragment length polymorphism (PCR - RFLP). The analysed fragment was 224 bp in length. According to the published cDNA sequence, exon 9 of the LDL receptor gene contains several hypermutable CpG dinucleotides. Three of these sites are Hpa II recognition sites. PCR product of exon 9 obtained from amplification of wild-type DNA sample would yield four fragments after Hpa II digestion. The expected sizes of these restriction fragments were 15, 30, 40 and 139 bp. All normocholesterolemic subjects (n = 33) showed normal RFLP. However, in one patient (72 year old female), abnormal RFLP from Hpa II digestion of the amplified exon 9 was observed, i.e., a fragment of 70 bp and another one smaller than 139 bp. Such RFLP reflects that exon 9 of both alleles of the LDL receptor gene in this patient lost one and gained one Hpa II site. It is interesting that this patient, eventhough harbouring two mutations on both alleles of the LDL receptor gene (presumably homozygous genotype of FH), apparently revealed lipid levels of heterozygous phenotype of FH without symptoms of coronary artery disease. It has yet to be proved whether these genetic variations are disease-related mutations or presumably common DNA polymorphisms.

Serum magnesium in Thai coronary artery disease patients

Hypomagnesemia or magnesium (Mg) deficiency has been hypothesized to play a role in coronary artery disease (CAD). The authors aimed to evaluate serum Mg concentration in 100 CAD patients compared with 100 healthy controls. Mean values of serum Mg level in CAD and the control group were 2.14 +/- 0.39, 2.24 +/- 0.3 mg/dL respectively (P=0.052). The prevalence of Mg deficiency was 12 per cent in the CAD patients, and 5 per cent in the control group (odds ratio=2.59, 95% confident interval = 0.88-7.65, P=0.063). There was no significant difference in the serum Mg level between the 2 groups, although it tended to be lower in CAD patients. The prevalence of Mg deficiency did not differ significantly between the study group, however, it tended to be higher in CAD patients. These findings demonstrated that CAD patients may be associated with Mg deficiency, and contribute to the pathogenesis of CAD or acute thrombosis. Following this evidence, Mg treatment may be necessary in CAD patients with Mg deficiency or acute myocardial infarction (AMI).

Chronic infections and atherosclerosis

The established risk factors for atherosclerosis such as hypertension, smoking, diabetes mellitus, hyperlipidemia, and hyperhomocysteinemia do not explain clinical and epidemiological features of coronary heart disease (CHD). The role of infectious disease as a CHD risk factor may partly explain these features. Chronic infection with various microorganisms, particularly, Chlamydia pneumoniae, Cytomegalovirus (CMV) and Helicobacter pylori may play a role in etiological factors, linking inflammation and atherogenesis. Results from epidemiological studies, pathology of atherosclerotic plaques, animal studies, molecular biology and clinical antibiotic trials indicated a positive association between C. pneumoniae infection and CHD. Chronic infection might also influence preexisting plaque by enhancing T cell activation, which participate in destabilization of intimal cap. However, the exact nature of pathophysiological link between the organisms and CHD remains to be elucidated. Future antibiotic interventional studies may help to further clarify the role of chronic infection and inflammation in CHD.

Inexpensive, rapid and convenient PCR-minigel SSCP protocol for polymorphisms and mutations analyses of LDL receptor gene

Hypercholesterolemia has been recognized as a major risk factor of atherosclerosis and coronary artery disease. The elevation in plasma low density lipoprotein (LDL) cholesterol is frequently due to genetic alteration at the genetic locus specifying the LDL receptors, leading to defective catabolism of LDL. In order to facilitate the molecular diagnosis of LDL receptor disorder, single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction (PCR) amplified genomic DNA fragments has become a simple and sensitive screening method for identification of DNA polymorphisms and mutations in LDL receptor gene prior to DNA sequencing. In addition, SSCP patterns can be detected by silver staining to avoid hazardous radioactive material or other costly nonradioactive detection techniques. However, the original SSCP protocol is generally large-formatted, which is both time and reagents consuming as well as cumbersome. Minigel SSCP protocols have thus been devised but they involve, although commercially available, costly precast gels. We describe here a nonradioactive PCR-minigel SSCP protocol which is sensitive, inexpensive, rapid, reproducible and manually convenient. The results in this study demonstrate that minigel-SSCP (gel size: 10 cm x 7.3 cm x 0.075 cm) can detect conformation polymorphisms in PCR-fragments with a comparative sensitivity to large gel SSCP (gel size: 30 cm x 40 cm x 0.04 cm) as exemplified by the SSCP analyses of exon 13 of the LDL receptor gene. For minigel SSCP, the reagents for gel components and silver staining are reduced approximately 9 times and 10 times, respectively. For electrophoresis, electrical power is also reduced 10 times. This improved technique can become routinely used for molecular diagnosis of LDL receptor defect as well as for other genetic disorders.

Screening for mutations in exons encoding the ligand-binding domain of the LDL receptor gene using PCR-CFLP and PCR-SSCP

Primary hypercholesterolemia includes both monogenic disorders and polygenic conditions. Two well defined monogenic disorders are familial hypercholesterolemia (FH) and familial defective apolipoprotein (apo) B-100 (FDB). Both disorders convey high risk of premature coronary artery disease. FH and FDB are caused by mutations in LDL receptor and apo B-100 genes, respectively. In the present study, mutations in both genes in Thai subjects with primary hypercholesterolemia were screened. For apo B-100 gene, a common mutation R3500Q was screened. This mutation was not observed in the patients (n = 45). For LDL receptor gene, mutations in the exons encoding the ligand-binding domain were screened. By PCR-CFLP analysis, 18 abnormal CFLP patterns in exon 4, the hot spot for mutations, were found in patients (n=45). One of the DNA samples with abnormal CFLP patterns was previously identified and reported as a possible disease-causing mutation, namely D151Y. For the other exons, the screening technique was PCR-SSCP. Abnormal SSCP patterns in DNA samples from patients (n=20) were found as follows, two in exon 3, one in exon 5 and another one in exon 6. Further characterization by DNA sequencing and family studies for these abnormal patterns are underway.

Roxithromycin in prevention of acute coronary syndrome associated with Chlamydia pneumoniae infection: a randomized placebo controlled trial

The role of Chlamydia pneumoniae infection in precipitating acute coronary syndrome (ACS) is unclear. Some studies have indicated that intervention with macrolide antibiotics might reduce coronary events in patients with ACS. A double blind, randomized, placebo-control trial was conducted on 84 ACS patients. Patients were randomized to 30 days of treatment with roxithromycin (150 mg, twice daily) or matching placebo. The follow-up period was 90 days, and the primary clinical end point included cardiovascular death, unplanned revascularization and recurrent angina/MI. Anti-C. pneumoniae IgG positive in 24 of 43 (55.8%) patients in the roxithromycin group and 23 of 41 (56.1%) patients in the placebo group. Anti-C. pneumoniae IgA positive in 20 of 43 (46.5%) patients in the roxithromycin group and 13 of 41 (31.7%) patients in the placebo group. Thirty-three cardiac events occurred (2 cardiovascular deaths, 9 CABG, 12 PTCA and 10 recurrent angina/MI) with 17 events in the roxithromycin group and 16 events in the placebo group. There was no significant difference of cardiac events between the roxithromycin and placebo groups. The present study suggests that antibiotic therapy with roxithromycin is not associated with reduction of cardiac events as reported by other investigators. However, therapeutic interventions may need to be specifically targeted to a group of patients who are confirmed with chronic C. pneumoniae infection.

Homocysteine and restenosis after percutaneous coronary intervention

Numerous clinical studies in Western and Asian countries suggest that individuals with elevated blood levels of homocysteine have an increased risk of atherosclerosis, myocardial infarction, cerebral infarction, and deep vein thrombosis. Homocysteine is also known to induce both atherogenic and thrombogenic mediators in cultured vascular cells so that homocysteine may influence the damage of endothelial cells, promote smooth muscle cell growth, induce atherogenic mediators and thrombus formation after coronary angioplasty. The association between homocysteine and restenosis after percutaneous coronary intervention (PCI) has been discussed. In this study, the relationship between plasma homocysteine levels and restenosis after PCI to investigate whether plasma homocysteine levels may be a predictor of restenosis after PCI was examined. One hundred consecutive patients who underwent successful PCI were enrolled and plasma homocysteine level was measured in all patients prior to PCI. Plasma for homocysteine level was obtained in 99 of 100 patients who had angioplasty. The mean plasma homocysteine concentration in the enrolled patients was 13.61 +/- 6.04 micromol/L. The minimum and maximum of plasma homocysteine were 4.40 micromol/L and 50.00 micromol/L, respectively. In healthy subjects, the normal reference range of homocysteine level is 5-15 micromol/L However, recent data suggest that some patients may be at increased cardiovascular and cerebrovascular risk at levels as low as 12 micromol/L. For this reason, both cut off points of homocysteine level > or = 15 micromol/L or > or = 12 micromol/L to identify the high homocysteine level group were used. Of 99 patients, high homocysteine level (> or = 15 micromol/L) was established in 9 patients with restenosis versus 20 patients without restenosis. If the cut off point of homocysteine level > or = 12 micromol/L was used, high homocysteine level was established in 14 patients with restenosis versus 39 patients without restenosis. From both cut off points of homocysteine level, there was no correlation between plasma homocysteine level and the restenosis group. (p>0.05).

Rapid detection of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells of coronary artery disease patients by real-time fluorescence PCR

Several recent reports including serological, pathological and animal studies have associated Chlamydia pneumoniae with coronary artery disease (CAD). In order to establish whether chronic C. pneumoniae infection is linked to coronary artery disease, clinical intervention trials may be needed. However, to detect eligible patients with persistent infection, a reliable diagnostic marker must be developed for identifying cases and assessing efficacy of antichlamydial therapy. Moreover, the prevalence of circulating C. pneumoniae DNA in CAD patients varied widely from previous reports. A real-time PCR has been established by using HL-1 and HR-1 primer to amplify 437 base pairs product. Confirmation of the product was performed on LightCycler by melting curve analysis of detection probes labeled with LC-Red705. Ninety-five angiographically confirmed CAD patients and 104 normal, healthy volunteers were recruited. The mononuclear cell layer was separated from collected blood and rapid, single step real-time PCR was used to detect C. pneumoniae DNA. C. pneumoniae DNA in peripheral blood mononuclear cells (PBMC) was found in 17 per cent of 95 CAD patients and 1 per cent of 104 normal healthy volunteers (odds ratio 20.86, 95% confidence interval 2.71 - 160.67, p < 0.0001). There was no association between C. pneumoniae DNA in PBMC and serological status. The rapid, real-time PCR showed a clear-cut result between positive and negative cases. PBMC-based real-time PCR may be a useful tool for identifying subjects carrying C. pneumoniae in the circulation or in the vascular wall as well. It will be a specific indicator of current infection and will be used as a marker for assessing the microbiological efficacy of antichlamydial therapy in clinical intervention trials.

Prevalence of hyperhomocysteinemia in normal healthy Thai subjects

The concentration of circulating total homocysteine is a sensitive marker of inadequate folate and vitamin B12 status. The elevations of plasma homocysteine concentration are associated with an increased risk of vascular disease. The primary goals of this study were to identify plasma homocysteine concentrations in Thai residents and to test for differences in homocysteine levels among sex and age categories. The authors measured plasma total homocysteine concentrations in 3,345 Shinawatra employees (1,133 males, 2,212 females aged between 20-65 years) by using fluorescence polarization immunoassay (FPIA) method. The mean plasma homocysteine concentrations of males and females were 11.495 and 8.547 micromol/L respectively. Plasma homocysteine concentrations were significantly lower in females than in males (p < 0.0001). The age-specific plasma homocysteine levels were lower in females than in males for each group, but the levels of each group was not significantly different both in males and females. When more than 12 micromol/L was used as the cut-off value, it was found that 33.6 per cent of males and 6.69 per cent of females were classified as hyperhomocysteinemia subjects. The authors concluded that the prevalence of hyperhomocysteinemia in Thai males is more common than in females. Further investigation should be done to clarify the association between serum folate, vitamin B12, vitamin B6 concentrations and plasma homocysteine concentration.

Serum nitric oxide levels in patients with coronary artery disease

Nitric oxide (NO) plays a pivotal role in the pathophysiology of coronary artery disease. The roles of NO are not only physiological but also pathological in the cardiovascular system. An inappropriate release of NO has been linked to the pathogenesis of CAD. The authors investigated whether serum NOx (nitrate and nitrite), a stable end product of NO, level was related to patients with coronary artery disease. The blood chemistry, such as cholesterol, triglyceride, LDL-C, HDL-C and blood sugar, was also measured in comparison with serum NOx. Serum NOx was measured in samples from 20 healthy controls, 20 angina patients without angiographic evidence of coronary lesions (CAG) and 20 angina patients with angiographic evidence of coronary lesions (CAD) by using modified Griess reaction. The mean serum NOx levels in the CAD groups was higher than CAG and control groups (41.3 +/- 5.5, 32.7 +/- 3.9 and 25.7 +/- 3.5 micromol/L, respectively). NOx levels in the CAD group was only significantly higher than the control groups (p < 0.05) but not the CAG groups. There were no significant differences of NOx levels in all age groups. In the CAD group, women showed significantly higher NOx levels than men (64.0 +/- 7.5 and 29.0 +/- 4.7 microl/L, respectively, p < 0.05). Interestingly, the mean serum NOx levels in the CAD groups was significantly higher in a group of abnormal lipid profiles (cholesterol, triglyceride, LDL-C) and blood sugar than in a group of normal profiles. The results suggested that there was an increased NOx levels in patients with coronary artery disease and much higher in patients with multiple underlying conditions such as hyperlipidemia and hyperglycemia. Thus, the measurement of the NOx levels at different times may help to monitor the state and severity of coronary artery disease.

Serum concentrations of lipids and apolipoprotein E in angiographically defined coronary artery disease patients

Apolipoprotein (apo) E is an important component of plasma lipoproteins and influences lipoprotein metabolism through its action as a receptor ligand. The association of serum apo E concentrations and coronary artery diseases (CAD) was investigated in 100 CAD patients (71 men, 29 women, mean age 62.0 years) and 155 healthy volunteers (87 men, 68 women, mean age 50.6 years). Patients with CAD had lower serum apo E concentrations (5.1+1.3 mg/dL) than the healthy volunteers (5.9+1.8 mg/dL, p <0.001). There were no significant differences between the number of disease vessels and the concentration of serum apo E. Serum apo E concentrations may have an anti-atherosclerotic effect and the serum apo E levels could be a useful parameter for defining cardiovascular risk factor.

Serum lipoprotein (a) level and restenosis after percutaneous coronary intervention

Restenosis is regarded as the result of a combination of various pathological events. The mechanisms are complex and not completely understood. In this study, the authors focused on the lipoprotein (a) (Lp (a)). It is one of the novel risk factors in atherosclerotic vascular disease. Numerous clinical studies suggest that individuals with elevated blood levels of Lp (a) have been shown to be associated with atherosclerotic vascular disease. However, whether a high serum concentration of Lp (a) affects restenosis after PCI remains controversial. In this study, the relationship between serum Lp (a) levels and restenosis after PCI was examined to investigate whether serum Lp (a) levels may be a predictor of restenosis after PCI. Of the 100 patients studied, 31 patients (31%) were classified as the restenosis group and 69 patients (69%) the non-restenosis group. Both groups did not significantly differ in serum concentration of total cholesterol, triglyceride, HDL-C, and LDL-C. The mean serum Lp (a) concentration in patients with restenosis was 41.50 +/- 34.99 mg/dL compared with a mean serum Lp (a) concentration of 29.87 +/- 25.47 mg/dL in those without restenosis. There was no statistical significance of Lp (a) level between the restenosis and non-restenosis groups (p=0.06). In healthy subjects, the normal reference range of serum Lp (a) concentration is below 30 mg/dL. From this reference, if a cut off point of serum Lp (a) concentration equal to 30 mg/dL or above to identify high Lp (a) level group was used. High serum Lp (a) level was established in 15 patients with restenosis versus 21 patients without restenosis. From this cut off point of serum Lp (a) level, the authors did not find a correlation between serum Lp (a) level and the restenosis group. (p=0.08).

Effect of HbE and HbH on HbA1C level by ionic exchange HPLC comparing to immunoturbidimetry

BACKGROUND

The hemoglobin (Hb)A1C level is widely used to monitor diabetes mellitus patients. The N-terminal amino acid valine of its beta chain is glycated. The assay of HbA1C is based on differences in the charge, chemical and structural properties of the protein.

METHODS

There are fully automated instruments available in clinical chemistry laboratory to assay HbA1C level. The effect of hemoglobinopathies was studied between an ionic exchange high-pressure liquid chromatography (HPLC) (Bio-Rad Laboratories, USA) and immunoturbidimetry (BM/Hitachi 912 with Roche HBA1CII, Germany-Japan) assay. The influence of high level HbF relative to the HbA1C level by ionic exchange HPLC is known. The effect of HbE and HbH to the HbA1C level by ionic exchange HPLC comparing to immunoturbimetry was examined. The evaluation was performed on 34 normal controls (A2A), 17 beta thalassemia traits (A2 upward arrow A), 36 HbE heterozygotes (EA), 37 HbE homozygotes (EE), 36 beta thalassemia/HbE (EF/EFA), 11 EABart's diseases (EABart's), 34 Hb H diseases (A2/CSAH) and 13 cord blood samples (FA).

CONCLUSIONS

Hemoglobinopathies can impact on the assay of HbA1C level such as HbE and HbH to ionic exchange HPLC. Although not studied as yet, this effect may influence the other methods such as affinity chromatography.

DHEA(S): the fountain of youth

Dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are weak androgens produced primarily by the adrenal gland. Although their plasma concentrations by far exceed those of any other adrenal product, their physiological roles have not yet been determined. In plasma, where the major portion of these hormones is present in the sulfate form, it is possible that DHEAS serves as a reservoir for DHEA. Since various tissues have been shown to contain steroid sulfatases. The peak plasma levels of DHEA and DHEAS occur at approximately age 25 years, decrease progressively thereafter, and diminish by 95 per cent around the age of 85 years. The decline of DHEAS concentrations with aging has led to the suggestion that DHEAS could play a role in itself and be implicated in longevity. Moreover, the epidemiological evidence has shown that adult men with high plasma DHEAS levels are less likely to die of cardiovascular disease. DHEA has also been shown to increase the body's ability to transform food into energy and burn off excess fat. Another recent finding involves the anti-inflammatory properties of DHEA. It has been known that DHEA can lower the levels of interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-alpha). It should be pointed out that chronic inflammation is known to play a critical role in the development of the killer diseases of aging: heart disease, Alzheimer's disease and certain types of cancer. In conclusion, DHEA or DHEAS administration combined with conventional treatment may be implicated in particular conditions to improve the quality of life.

Serum dehydroepiandrosterone sulfate, testosterone, and biochemical markers of bone turnover in elderly Thai men

The most abundant human steroid, dehydroepiandrosterone sulfate (DHEAS), may have a multitude of beneficial effects, but declines with age. It is unclear whether DHEAS deficiency is an important factor contributing to increased bone resorption and impaired bone formation or not that leads to their bone loss. Thus, we investigated serum DHEAS, testosterone, osteocalcin (N-MID osteocalcin) and C-terminal telopeptides (beta-CrossLaps) in 121 healthy Thai males without bone diseases. Thirty-nine males (mean age 31.5 +/- 8.2, range 23-42 years) were recruited as the normal adult group and 82 males (mean age 61.2 +/- 7.0, range 52-77 years) were assigned as the elderly group. DHEAS levels were higher in the adult group compared with the elderly subjects (296.8 +/- 93.4 vs 172.6 +/- 99.8 microg/dL, p < 0.0001). Serum osteocalcin concentrations were also higher in the adult group compared with the elderly males (27.9 +/- 11.1 vs 23.2 +/- 7.9 ng/ml, p = 0.0091). However, serum testosterone and C-terminal telopeptides levels were not significantly different between the two groups. We concluded that low DHEAS concentrations are commonly encountered in elderly males and may relate to low osteocalcin levels due to the osteoblast stimulation effects of DHEAS. These findings may be implicated in the treatment of osteoporosis in elderly men by using DHEAS.

Biochemical markers of bone turnover in angiographically-demonstrated coronary artery disease patients and healthy Thais

The patients with coronary artery disease (CAD) were suffering from dyspnea. Physical activity of these patients was limited. Their lifestyle may be contributory factors for osteoporosis. Recent research has shown that biochemical markers may be used to predict future bone loss and identify individuals at risk for osteoporosis. Our objectives were to estimate reference ranges of bone markers in healthy Thais and to compare bone turnover between 105 healthy people and 118 CAD patients by using biochemical markers of bone formation and resorption. Mean values of bone markers in controls and patients were 22.9 +/- 12.9, 21.6 +/- 16.2 respectively for N-Mid osteocalcin and 0.45 +/- 0.30, 0.47 +/- 0.37 respectively for beta-Crosslaps. There was no statistical difference of N-Mid osteocalcin (p=0.50) and beta-Crosslaps (p=0.64) values between groups. Our data from this study suggested that that CAD patients have no higher risk for osteoporosis than healthy people.

Correlation of serum lipoprotein(a) with the clinical presentation of Thai coronary artery disease patients

Elevated serum levels of lipoprotein(a) [Lp(a)] confer an increased risk of coronary artery disease (CAD) and have been confirmed as a strong and independent risk factor for this disease. This case-control study was to determine the significance of elevated Lp(a) levels for the existence of CAD by systematically recording cardiovascular risk factors in diagnostic coronary angiography in a group of patients. Two hundred thirty seven consecutive patients (175 men, 62 women, aged 61+/-10 years) which comprised 24 acute myocardial infarction (AMI), 76 unstable angina (UA) and 137 stable angina (SA) who underwent coronary angiography, were used as cases. One hundred seventy normal healthy volunteers (95 men, 75 women, and aged 58+/-15 years) were used as controls. Lp(a) concentration were measured by an immunoturbidimetric method (Roche Diagnostics, Switzerland). There was a significant difference between Lp(a) levels in UA compared with the control subjects (44.2+/-49.0 vs. 27.6+/-25.3 mg/dL, p = 0.0006). When we compared SA and the control group (35.6+/-31.3 vs. 27.6+/-25.3 mg/dL, p = 0.0139) there was a significant difference between these two groups. UA patients also had a significantly higher prevalence of abnormal Lp(a) (>30 mg/dL) compared with the normal healthy control group (43.2% UA vs. 28.8% control, OR = 1.90, 95%CI = 1.08-3.32, p = 0.0248). SA patients also had the same finding as UA patients in a higher prevalence of abnormal Lp(a) when compared with the control group (45.2% SA vs. 28.8% control, OR = 2.04, 95%CI = 1.27-3.27, p = 0.0028). These data further support the role of Lp(a) in atherosclerotic coronary disease and the pathogenesis of acute coronary syndromes.

Analytical and clinical performance of two homogeneous assays for measuring of LDL-cholesterol

A clinical laboratory currently estimates LDL-Cholesterol (LDL-C) concentration using the Friedewald calculation, which requires fasting specimens and is subject to error with increasing triglycerides levels. We evaluated the analytical and clinical performance of the direct LDL-C assay from two companies, Roche Diagnostics (LDL-C(Roche)) and Wako Pure Chemical (LDL-C(Wako)). Both methods meet current guidelines for precision with within-run coefficients of variation less than 3 per cent. The LDL-C(Roche) assay correlated well with the LDL-C from the Friedewald equation (LDL-C(Fried), r = 0.958, y = 0.85x + 17.08 mg/dL, n = 422). The LDL-C(Wako) assay also correlated with the LDL-C(Fried) (r = 0.946, y = 0.86x + 7.81 mg/dL, n = 422). In addition, at the medical decision cutoff points, LDL-C(Roche) assay and LDL-C(Wako) showed positive predictive values of 87.44 per cent and 69.67 per cent respectively. We conclude that the LDL-C(Roche) assay meets the currently established analytical and clinical performance, but LDL-C(Wako) assay meets only analytical performance. Clinical performance needs further evaluation.

Impaired fasting glucose, diabetes mellitus and coronary risk factors

The authors conducted a prevalence survey of impaired fasting glucose and diabetes mellitus in 3,615 Shinawatra employees, and we also determined various risk factors of coronary artery disease such as blood pressure level, body mass index and serum lipids. The prevalence of impaired fasting glucose and diabetes mellitus were 1.7 per cent and 0.8 per cent respectively. The prevalences were more common in males and increased with increasing age. Coronary risk factors were higher in impaired fasting glucose (IFG) and diabetes mellitus (DM) when compared with normal glucose levels. There were also significant differences between impaired fasting glucose and diabetes mellitus, except for pulse pressure, serum cholesterol level, LDL-cholesterol level and HDL-cholesterol level.

Seroprevalence of Chlamydia pneumoniae infection in Thailand

Chlamydia pneumoniae (C. pneumoniae) is an emerging infectious agent, with a spectrum of clinical manifestations, and it has recently been tentatively linked to atherosclerosis. In order to describe the seroprevalence of C. pneumoniae in Thailand, we evaluated 1,798 normal healthy subjects (aged 20-93 years) for anti-C. pneumoniae IgG and IgA. Specific antibodies were measured by the fully automated ELISA method using elementary bodies of C. pneumoniae as an antigen. IgG antibodies against C. pneumoniae were presented in 55.16 per cent of men and 41.63 per cent of women. Anti-C. pneumoniae IgA were presented in 31.50 per cent of men and 27.49 per cent of women. The prevalence of IgG antibody increased with age and reached 78 per cent in subjects between 51-93 years. The pattern of IgA antibody was a saddle shape, which indicated 2 peaks of chronic infection. Our results suggested that C. pneumoniae infection was common in Thailand. The high prevalence of evidence of exposure to C. pneumoniae may have implications for the prevention of cardiovascular disease if further study concludes that infection with this organism is a risk for cardiovascular disease.

Regular exercise and cardiovascular risk factors

Physical inactivity has been counted as a risk factor for coronary artery disease. Regular exercise has also been reported to reduce risk of cardiovascular disease and its risk factors. We surveyed 3615 subjects for their conventional risk factors of coronary disease and for the frequency of their exercise. We found that subjects who had regular exercise were more likely to have lower triglyceride and resting heart rate. HDL cholesterol was higher in the group of subjects who had regular exercise. There was no difference in fasting plasma glucose, total cholesterol or blood pressure levels between those who had and those who did not have regular exercise.

Serum cardiac troponin T in unstable angina pectoris patients

Cardiac troponin T (cTnT) is a regulatory contractile protein not normally found in blood. Its detection in the circulation has been shown to be a sensitive and specific marker for myocardial cell damage. In this study, we used a second-generation enzyme immunoassay for cTnT to determine whether its presence in the serum of patients with unstable angina was a prognostic indicator. Thirty patients with unstable angina pectoris (UAP) and 30 patients with Q-wave acute myocardial infarction (AMI) were screened for serum CK-MB activity and cTnT at 6, 12, 24 and 48 hours after the onset of chest pain, All of the mean concentrations of CK-MB activity determined in UAP patients were less than the upper limit of normal (25 U/L). Meanwhile, the mean concentration of cTnT at 6, 12, 24 and 48 hours after onset of chest pain were higher than the cutoff values (0.1 microg/L), We found that one third of UAP patients had serum cTnT at the time of admission more than 0.1 microg/L and that these groups of patients were associated with a high risk for cardiac events. Our results suggested that patients with elevated serum cTnT could be considered as high-risk patients for developing myocardial infarction, Patients with normal cTnT levels and a low or intermediate clinical risk could be stabilized and further stratified noninvasively.

Myocardial injury after radiofrequency catheter ablation

Radiofrequency catheter ablation has been a good treatment option for various types of cardiac arrhythmia. However there is concern about myocardial injury associated with radiofrequency catheter ablation. We studied myocardial injury with biochemical markers and echocardiogram in 41 consecutive patients who underwent electrophysiology study (EP study) and radiofrequency catheter ablation (RFCA) at our institute from April to July 2000. The concentration of biochemical markers (CK-MB mass, troponin T and myoglobin) and result of the echocardiograms were analyzed with other characteristics. In 41 patients subjected to EP study with possible RFCA, abnormal levels of troponin T, CK-MB mass and myoglobin were found in 46 per cent, 15 per cent and 44 per cent immediately after procedure, which went up to 64 per cent, 22 per cent and 2 per cent at twenty four hours. Compare to the group with normal troponin T level, the patients with abnormal level at 24 hours after RFCA had a longer procedure time (119+/-44 min. vs 90+/-22 min.), more frequent use of impedance ablation catheters (65% vs 27%), more RF applications (9+/-8 vs 18+/-16) and more ventricular ablation sites (69% vs 9%). The echocardiogram results showed no remarkable abnormality in any patients. Troponin T was the most sensitive marker to detect thermal myocardial injury associated with radiofrequency catheter ablation. Prolonged procedure time, RF applications, the use of impedance ablation catheter and ventricular ablation site were associated with elevated troponin T concentration after RFCA.

Comparison of parathyroid hormone in angiographically-demonstrated coronary artery disease patients and healthy Thais

Parathyroid hormone (PTH) influences the calcium metabolism. The idea of cardiovascular effects of PTH is not new. Target cells for PTH are cardiomyocytes and smooth muscle cells. Evidence from previous studies suggest that many patients with heart disease have elevated PTH concentrations. Our objective was to determine PTH status in patients with coronary artery disease (CAD). We compared intact PTH levels in 109 CAD patients with 103 healthy people by electrochemiluminescence immunoassay. Mean values of PTH in healthy Thais and CAD patients were 37.4 +/- 17.9 and 40.2 +/- 21.8 respectively. No statistical difference was shown. In addition, we compared PTH levels among various numbers of coronary occlusion and also found no differences. We propose that intact PTH concentrations in CAD patients are not higher than in the healthy population.

Obesity and risk factors of coronary heart disease in healthy Thais: a cross-sectional study

Association between obesity and conventional risk factors for coronary artery disease is well established. Obesity is currently considered an independent risk for coronary artery disease. The relationship between body mass index (BMI) and fasting plasma lipids and glucose and blood pressures in non-obese subjects is not established. The authors studied relationships between BMI and lipids, and glucose, and blood pressure levels in healthy a population. The authors measured the weights and heights of 3,615 employees of a company during a routine yearly health examination. There were 1,250 males aged 31.3 +/- 6.6 and 2,365 females aged 29.3 +/- 4.9 years old. The average BMI for males and females were 23.5 +/- 3.6 and 20.1 +/- 3.0 respectively. The levels of total cholesterol (Chol), LDL-cholesterol, and triglyceride (TG), fasting plasma glucose (FPG) had a positive relationship with BMI (r = 0.22, 0.26, 0.41, 0.20; p < 0.001). HLD-cholesterol had a negative correlation with BMI (r = -0.36, p < 0.001). Both systolic (SBP) and diastolic (DBP) blood pressures had a positive correlation with BMI. The association persisted after all values were adjusted by age and sex. BMI has a significant positive relationship with the conventional risk factors for coronary artery disease and a negative relationship with HDL-cholesterol.

Are routine checkups necessary?: The Shinawatra's employee study

The authors performed a survey in 3,615 Shinawatra employees aged 18-60 years to determine the abnormalities found with routine checkup. The annual checkup included: history taking. anthropometric measurement, physical examination, complete blood count, urine analysis, chest roentgenography, blood chemistry (fasting blood glucose, BUN, creatinine, uric acid, AST/ALT, cholesterol, triglyceride and HDL-cholesterol). The prevalence of abnormalities with management change detected by complete blood count, urine analysis was low and we did not recommend the routine use of complete blood count and urine analysis. The prevalence of hypertension was more common in males and the prevalence increased sharply after the age of 25 years in males and 40 years in females. The prevalence of abnormalities of BUN, creatinine (both males and females) and uric acid (in females) was very low. There was high prevalence of high AST/ALT which suggested hepatitis in our population, and the prevalence was more common in males beginning at a young age. Diabetes mellitus was more common in males especially after the age of 45 years. Chest roentgenography abnormalities were found in 9.4 per cent and the prevalence of abnormalities increased with age and was common after the age of 44 years. Most of the abnormalities found by chest roentgenography were pulmonary infiltration and cardiomegaly. The authors' findings did not recommend the routine use of complete blood count, urine analysis, fasting BUN and creatinine. We recommend routine blood pressure measurement in males aged 25 years or more and in females aged 40 years or more. We suggest routine blood cholesterol measurement in both sexes, blood triglyceride measurement in males aged 25 years or more and fasting blood sugar tests in males aged more than 44 years, chest roentgenography in males and females after the age of 45 years.

The prevalence of left ventricular hypertrophy and associated factors in a Thai population

Electrocardiographic left ventricular hypertrophy (LVH) has been a bad prognostic factor for cardiovascular morbidity and mortality. However the prevalence and prognostic value of LVH are varied among nationalities and populations. Several factors have been shown to associate with LVH. Some factors are treatable such as hypertension. We prospectively studied the prevalence of LVH and associated factors in selected group of Thai population. The study population was 1,606 Shinawatra employees who were 30 year old or more. The prevalence of LVH was 13 per cent (210) among study population. Hypertension, lower body weight and male sex were significantly associated factors. In the subjects with LVH, the prevalence of hypertension was 25.6 per cent, male ratio was 5:1 and mean body weight was 57.7 kg, compare to 9.8 per cent prevalence of hypertension, 2:1 female ratio and mean body weight was 62.3 kg in the group without LVH.

Prevalence of new coronary risk factors in Thai population

Many new cardiovascular biomarkers of atherosclerosis have recently been emerging. However, there is a paucity of these data in the Thai population. This study aims to determine the prevalence of these biomarkers of atherosclerosis and the relationship between these new risk factors and other conventional risk factors for atherosclerosis in the healthy Thai population. As a yearly check-up program, we surveyed 3,615 normal healthy populations for their conventional risk factors and some new cardiovascular biomarkers for atherosclerosis. The authors found hyperhomocysteinemia and high level of Lp(a) in 27 per cent and 32 per cent of the cases respectively. Prevalence of recent and past chlamydial infection was found in 30 per cent and 51 per cent respectively.

A 5-year prospective study of conventional risk factors of coronary artery disease in Shinawatra employees: a preliminary prevalence survey of 3,615 employees

We conducted a prevalence survey of conventional risk factors of coronary artery disease in 3,615 Shinawatra employees and we planned to prospectively follow up this population to determine the impact of the risk factors in the development of coronary disease. The prevalence of hypertension, diabetes mellitus, hyperlipidemia, obesity, physical inactivity and smoking were 7.4 per cent, 1.4 per cent, 21.1 per cent, 13.9 per cent, 76.3 per cent and 16.3 per cent respectively. The awareness of hypertension, diabetes mellitus and hyperlipidemia were 42.2 per cent, 78 per cent and 32.9 per cent respectively. The prevalence of the risk factors was more common in males and increased with increasing age. Dependent variables which were associated with hypertension included: excessive weight; male sex; increasing age; hypercholesterolemia and diabetes mellitus. Variables which were associated with diabetes mellitus were hypertriglyceridemia, hypertension, male sex, increasing age and excessive weight.. Variables which were associated with hypercholesterolemia were hypertriglyceridemia, high HDL-cholesterol, increasing age, excessive weight and hematocrit level while overweight, hypercholesterolemia, low HDL-cholesterol, smoking, hematocrit level, low income and increasing age were associated with hypertriglyceridemia. Excessive weight was associated with hypertriglyceridemia, low HDL-Cholesterol, presence of hypertension, hypercholesterolemia, diabetes mellitus, increasing age and low education.

Chlamydia pneumoniae antibodies and angiographically demonstrated coronary artery disease in Thailand

Recent reports have suggested an association between Chlamydia pneumoniae and coronary artery disease. This study investigated the relationship between the presence of immunoglobulin G (IgG), immunoglobulin A (IgA) of C. pneumoniae in angiographically diagnosed coronary disease. Patients enrolled were 243 (178 male, 65 female, mean age 61 +/- 10 years) with angiographically proven at least one significant coronary artery stenosis. Fifty-eight patients (33 male, 25 female, mean age 57 +/- 11 years) with no angiographic evidence of coronary lesions were used as the normal coronary angiogram group. Control subjects (95 male, 92 female, mean age 58 +/- 17 years) were used as normal healthy persons who had no history of coronary artery disease. C. pneumoniae IgG and IgA antibodies were measured by ELISA method. We found that 179 out of 243 (73.7%) coronary artery disease (CAD) patients were positive for IgG and 132 out of 243 (54.3%) were positive for IgA. In 58 normal coronary angiogram patients, 23 (39.7%) cases were positive for IgG and 6 (10.3%) cases were positive for IgA. Among 187 healthy controls, 111 (59.4%) cases were positive for IgG and 83 (44.4%) were positive for IgA. When C. pneumoniae IgG antibodies were considered, there was significant difference between CAD patients and healthy controls (OR = 1.91, 95% CI = 1.27 - 2.88, p = 0.0018). In cases of positive IgA antibodies, significant difference was also found between CAD patients and healthy controls (OR = 1.49, 95% CI = 1.02 - 2.19, p = 0.0257). These findings were also found with higher odds ratio when we compared between CAD patients and normal coronary angiogram patients. The result suggested that C. pneumoniae infection is common in Thai people and chronic C. pneumoniae infection is more common in CAD patients. Chronic C. pneumoniae infection may be associated with the development of atherosclerotic coronary disease and treatment with antibiotics should be considered in ischemic heart disease.

Amoxicillin for fever and sore throat due to non-exudative pharyngotonsillitis: beneficial or harmful?

OBJECTIVES

To determine duration of signs and symptoms and adverse reactions after treatment with amoxicillin of patients with fever and sore throat due to non-exudative pharyngotonsillitis.

DESIGN

This was a randomized, double-blinded, placebo-controlled trial. Outpatients at four medical centers were enrolled. Patients over 5 years of age presented with fever and sore throat for less than 10 days due to non-exudative pharyngotonsillitis. Cases with any of the following symptoms or illness were excluded: earache, nasal discharge with foul smell, rheumatic fever, valvular heart disease, renal disease, and penicillin hypersensitivity. Amoxicillin or identical placebo at the dosage of 50 mg/ kg per day was given three or four times daily for 7 days.

RESULTS

There were 1217 patients enrolled in this study. Some were lost to follow-up, which is the reason for the variability in number of cases in these analyses. After therapy, duration of fever was 2.46 and 2.48 days (P = 0.78) and of sore throat 3.01 and 3.04 days (P = 0.80) in amoxicillin (n = 431) and placebo (n = 436) groups, respectively. Complications were clinically documented in 13 (2.5%) and 16 (3.0%) cases in amoxicillin (n = 527) and placebo (n = 524) groups (P = 0.56). Two cases (0.46% and 0.46%) from each group (n= 433 and 431) were positive by antistreptolysin O antibody determination. The history of carditis and abnormal urinalysis after treatment were not obtained.

CONCLUSIONS

Amoxicillin therapy for non-exudative pharyngotonsillitis conferred no beneficial or harmful effect.

Association between serum homocysteine, vitamin B12, folate and Thai coronary artery disease patients

BACKGROUND

Homocysteine is an intermediate compound formed during metabolism of methionine. The plasma level of homocysteine is dependent on the genetically regulated level of essential enzymes and the intake of folic acid, vitamin B6 (pyridoxine), and vitamin B12 (cobalamine). Elevated serum homocysteine levels are a known risk factor for coronary artery disease (CAD). To establish the magnitude of the CAD that is associated with an increased serum homocysteine level, we compared CAD patients with normal healthy Thai controls.

METHOD

In a cross-sectional study design we investigated the association between serum homocysteine, vitamin B12 and folate levels and the coronary heart disease in 178 CAD patients and 178 normal healthy controls by age and sex matching. These comprised 266 men and 90 women, mean age 58 +/- 10 years for normal controls and 60 +/- 10 years for CAD patients. Serum homocysteine, vitamin B12 and folate were measured by ELISA method and electrochemiluminescense method respectively.

RESULTS

Paired t-test analysis showed that serum homocysteine concentrations were significantly higher in CAD patients (23.83 +/- 11.29 mumol/L) than in control subjects (19.69 +/- 8.51 mumol/L; p < 0.001). Homocysteine levels were also higher in males than in females. These findings were similar in healthy controls (male: 20.37 +/- 8.5 mumol/L, female: 17.77 +/- 8.2 mumol/L, p < 0.05) and in CAD patients (male: 24.91 +/- 11.8 mumol/L, female: 20.73 +/- 8.9 mumol/L, p < 0.05). Homocysteine above 17 mumol/L occurred more common in CAD patients than in control groups (OR = 1.65, 95% CI = 1.09-2.52, p = 0.0249). Low levels of vitamin B12 and folate did not reaching statistical significance when comparing controls and CAD patients.

CONCLUSIONS

Serum homocysteine concentrations were significantly higher in CAD patients than in controls. Serum vitamin B12 and serum folate levels were not statistically significantly different between CAD patients and control groups. The data also demonstrated that the serum homocysteine level is almost always higher in men than in women as previously reported. Although serum vitamin B12 and serum folate levels were not below the upper limit of normal, vitamin B12 and folic acid treatment may reduce serum homocysteine concentrations in CAD patients. We hope that the reversible risk factors will be concern to clinicians for the reduction in the risk of myocardial infarction.

The prevalence of Chlamydia pneumoniae antibodies in Thai patients with coronary artery disease

Blood samples were obtained from 243 consecutive coronary artery disease (CAD) patients (177 male, 66 female) aged 35-78 years (mean, 61 years) admitted for coronary angiography because of suspected coronary heart disease, and from 115 blood donors (91 male, 24 female) aged 25-60 years (mean, 47 years). Of the 243 CAD patients, 179 (74%) were positive by an ELISA method for Chlamydia pneumoniae antibodies IgG and 132 (54%) were positive for C. pneumoniae IgA. Among the 115 blood donors, 80 (70%) were positive for C. pneumoniae IgG and 49 (43%) were positive for C. pneumoniae IgA. When IgG antibodies were considered, there was no significant difference between CAD patients and healthy controls (OR = 1.29, 95% CI = 0.79-2.10, p > 0.05). In cases of positive IgA antibodies alone, there was a significant difference between CAD patients and healthy controls (OR = 1.58, 95% CI = 1.01-2.4, p = 0.029). If both IgG and IgA antibodies were positive, OR was increased from 1.58 to 1.80 (95% CI = 0.97-3.36, p = 0.044). In conclusion, C. pneumoniae infection is common in Thai people but chronic C. pneumoniae infection is more common in CAD patients than in middle-aged blood donors.

Improved detection of radiofrequency current-induced minor myocardial injury by cardiac troponin T measurement

Transcatheter radiofrequency current application in patients with cardiac arrhythmias was reported to be associated with a low rate of an increase in the activity of enzyme creatine kinase (CK) and CK-MB isoenzyme. As the novel heart-specific protein troponin T (cTnT) was shown to be superior to CK and CK-MB in detecting small damage to myocardial tissue in various clinical situations including unstable angina, a comparison of the diagnostic efficiency of these marker proteins to detect myocardial damage was made in 34 patients (mean age 38.3 +/- 15.6 years) undergoing radiofrequency (RF) catheter ablation of accessory pathways (n = 17) and atrioventricular nodal reentrant tachycardia (n = 17). Serial measurements of total CK and CK-MB activity before and every 8 hours for 24 hours after ablative procedure were performed with enzymatic and immunoinhibition method, respectively, using automated chemical analyzer Hitachi 717. Serum concentration of cTnT was determined by one-step sandwich ELISA performed on ES 300 analyzer (Boehringer Mannheim). With a median of 7.0 (range 1-39) RF current pulses only 12 (35%) and 10 (29%) of 34 patients showed an increase above the upper limit of normal CK and CK-MB activity, respectively. The peak activity of CK (mean peak = 285.8 +/- 517.7 IU/L) occurred at a variable time that infrequently coincided with those of peak CK-MB activity (23.1 +/- 8.0 IU/L). By contrast, all except 4 (88%) of 34 patients exhibited a distinct elevation of cTnT concentration (mean peak = 0.56 +/- 0.63 ng/ml), with almost all (33) of these 34 patients showed an early peak value at 8 hours postprocedural. There was, on the average, a small but distinct higher relative increase (5.6 times) in cTnT concentration from the upper limit of reference range compared with those of CK (1.5 times) and CK-MB peak activity (0.9 time). In conclusion, cTnT exhibited a minor but distinct elevation in its concentration and demonstrated a higher rate and magnitude of increase following radiofrequency current application than the conventional CK and CK-MB isoenzyme. Measurements of cTnT serum concentration may thus provide a useful test method for assessing the effect of the new transcatheter ablation procedures on myocardial tissue.

Metabolic and immune effects of dietary arginine, glutamine and omega-3 fatty acids supplementation in immunocompromised patients

To evaluate the nutritional, metabolic and immune effects of dietary arginine, glutamine and omega-3 fatty acids (fish oil) supplementation in immunocompromised patients, we performed a prospective study on the effect of immune formula administered to 11 severe trauma patients (average ISS = 24), 10 burn patients (average % TBSA = 48) and 5 cancer patients. Daily calorie and protein administration were based on the patient's severity (Stress factor with the range of 35-50 kcal/kg/day and 1.5-2.5 g/kg/day, respectively) Starting with half concentration liquid immune formula through nasogastric tube by continuous drip at 30 ml/h and increasing to maximum level within 4 days. The additional energy and protein requirement will be given either by parenteral or oral nutritional support. Various nutritional, metabolic, immunologic and clinical parameters were observed on day 0 (baseline), day 3, 7, and 14. Analysis was performed by paired student-t test. Initial mean serum albumin and transferrin showed mild (trauma) to moderate (burn and cancer) degree of malnutrition. Significant improvement of nutritional parameters was seen at day 7 and 14 in trauma and burn patients. Significant increase of total lymphocyte count (day 7, P < 0.01), CD4 + count (day 7, p < 0.01), CD8 + count (day 7, p < 0.0005 & day 14, p < 0.05), complement C3 (day 7, p < 0.005 day 14, p < 0.01), IgG (day 7, and 14, p < 0.0005), IgA (day 7, p < 0.0005 & day 14, p < 0.05), in all patients. C-reactive protein decreased significantly on day 7 (p < 0.0005) and day 14 (p < 0.005). 3 cases of burn wound infection, one case of UTI and one case of sepsis were observed. Two cases of hyperglycemia in burn, 3 cases of hyperbilirubinemia in trauma, 10 cases of elevated LFT (5 trauma/5 burn), and one case of hyponatremia in cancer patients were observed. Two cases of nausea, 4 cases of vomiting, 5 cases of diarrhea (< 3 times/day), 2 cases of abdominal cramp, 1 case of distension were observed. The feeding of IMMUNE FORMULA was well tolerated and significant improvement was observed in nutritional and immunologic parameters as in other immunoenhancing diets. Further clinical trials of prospective double-blind randomized design are necessary to address the so that the necessity of using immunonutrition in critically ill patients will be clarified.

A new alpha chain variant Hb Tonosho [alpha 110(G17)Ala----Thr]: subunit dissociation during cation exchange chromatography for Hb A1c assay

A new alpha chain variant, alpha 110(G17)Ala----Thr, was detected because of subunit dissociation during the determination of the Hb A1c by automated cation exchange high performance liquid chromatography. The abnormal hemoglobin overlapped the cathodic edge of the band of Hb A in isoelectrofocusing. It was slightly unstable in the isopropanol test and had a slightly increased oxygen affinity. The abnormal alpha chain eluted slightly faster than the normal alpha chain in reversed phase high performance liquid chromatography. The amino acid substitution was determined by purification of S-alkylated alpha T-12,13 tryptic peptide, chymotryptic digestion, and sequencing of an octapeptide alpha 110-117. The abnormal alpha chain comprised about 14% of the total alpha chain. A biosynthetic study did not suggest selective loss of the abnormal chain in reticulocytes.

Laboratory assessment of thrombolytic therapy in acute myocardial infarction

Hemostatic profiles and cardiac enzymes were studied in 55 acute myocardial infarct (AMI) patients to assess SK and rt-PA therapy. Hypofibrinogenemia occurred 85% in SK group and 55% in rt-PA group with high FDP and D-Dimer, indicating systemic fibrinogenolysis and local crosslinked fibrin clot lysis. The incidence of bleeding in SK and rt-PA groups combined with anticoagulants were the same but lower in rt-PA with antiplatelet. The mean FDP was significantly higher in the bleeding group (p < 0.01). Cardiac enzymes: CK, CK-MB peak values indicated reperfusion were 26.6%, 60% and 90% in conventional, SK and rt-PA therapy, respectively. Early and late occlusion did not occur either in SK or rt-PA followed by anticoagulants. Late occlusion was found in patients treated with rt-PA and antiplatelet. Mortality rate was 20% in conventional therapy.