Urinary sulfated glycosaminoglycan insufficiency and chondroitin sulfate supplement in urolithiasis

Familial members of urolithiasis have high risk for stone development. We observed the low sulfated glycosaminoglycan (GAG) excretion in urolithiasis patients and their descendants. In this study, we investigated urinary excretion of sulfated GAG, chondroitin sulfate (CS), heparan sulfate (HS) and hyaluronic acid (HA) in urolithiasis and their children, and explored the effect of CS and HA supplement in urolithic hyperoxaluric rats. The 24-hour urines were collected from urolithiasis patients (28) and their children (40), as well as healthy controls (45) and their children (33) to measure urinary sulfated GAG, CS, HS and HA excretion rate. Our result showed that urinary sulfated GAG and CS were diminished in both urolithiasis patients and their children, while decreased HS and increased HA were observed only in urolithiasis patients. Percentage of HS per sulfated GAG increased in both urolithiasis patients and their children. In hyperoxaluric rats induced by ethylene glycol and vitamin D, we found that CS supplement could prevent stone formation, while HA supplement had no effect on stone formation. Our study revealed that decreased urinary GAG and CS excretion are common in familial members of urolithiasis patients, and CS supplement might be beneficial in calcium oxalate urolithiasis prophylaxis for hyperoxaluric patients.

Lime powder regimen supplement alleviates urinary metabolic abnormalities in urolithiasis patients

BACKGROUND

Urolithiasis has high recurrent rate after surgical removal within 3 years. Potassium citrate compound is used to prevent stone recurrence but it has intolerable gastrointestinal adverse effects. We conducted a phase 2 clinical study of lime power regimen (LPR), a limeade-based supplement containing potassium and citrate for 6 months period of treatment, to evaluate its effects on biochemical and clinical aspects of recurrent urolithiasis.

METHODS

Seventy-four urolithiasis patients were randomly allocated to receive either LPR or placebo for 6 months in a double-blinded manner. Plasma and 24 h urine samples were collected to measure urinary pH, mineral excretion and urinary total antioxidant status , plasma for creatinine and plasma protein carbonyl, and stone for elemental analysis at the initiation and end-of-treatment (6 month). Adverse effects were recorded.

RESULTS

Administration of LPR significantly increased urinary pH, citrate and potassium excretion. Urinary levels of calcium and oxalate, and plasma protein carbonyl content were reduced, while urinary total antioxidant status was elevated by LPR treatment. Urinary supersaturation was decreased and urinary protein excretion was ameliorated in LPR-treated patients. Gastrointestinal adverse effects were rarely observed. None of the participants developed stone recurrence for the duration of the trial.

CONCLUSION

Lime power regimen is a potential drug to correct urinary metabolic disorders associated with urolithiasis in high risk stone recurrent patients. A phase 3 clinical trial is underway to validate anti-stone recurrence property of LPR in long-term treatment.

Urinary stone risk factors in the descendants of patients with kidney stone disease

BACKGROUND

Evidence has indicated that immediate family members of nephrolithiasis patients had high opportunity to develop stones. However, they are usually not regarded to be at risk, since it is unclear if there are any lithogenic abnormalities found in non-stone-forming nephrolithiasis relatives. Our aim was to investigate urinary metabolic abnormalities in the children of nephrolithiasis patients, compared with the general population.

METHODS

The 24-h urinary metabolic profile was studied for 28 calcium oxalate nephrolithiasis patients (NL) and 46 of their descendants (ND), as well as 40 non-stone-forming volunteers (V) and 34 of their descendants (VD).

RESULTS

There was no difference between age, gender, and serum creatinine between NL vs. V (parental groups) and ND vs. VD (descendant groups). High urinary oxalate in nephrolithiasis and urinary calcium in their descendants was detected. In addition, an elevated urinary excretion rate of calcium, phosphate, protein, and albumin, along with low citrate excretion and high urinary supersaturation was observed in both the nephrolithiasis patients and their descendants. Approximate 17.8-24.4% of the nephrolithiasis descendants had a urinary supersaturation higher than the nephrolithiasis level, but none was found in VD group. The level of urinary supersaturation index was correlated with urinary protein and albumin excretion in nephrolithiasis family.

CONCLUSION

It was demonstrated that nephrolithiasis offspring carried several urinary metabolic risks predisposing to stone formation which are similar to their parents, and about one in every five nephrolithiasis children had nephrolithiasis level urinary supersaturation.

Combination of vitamin E and vitamin C alleviates renal function in hyperoxaluric rats via antioxidant activity

Hyperoxaluria and oxidative stress are risk factors in calcium oxalate (CaOx) stone formation. Supplement with antioxidant could be effective in prevention of recurrent stone formation. The present study aims to evaluate the protective effects of vitamin E and vitamin C in hyperoxaluric rat. The experiment was performed in rats for 21 days. Rats were divided into 5 groups as follows: control (group 1, n=8), hyperoxaluric rats (group 2, n=8), hyperoxaluric rats with vitamin E supplement (group 3, n=7), hyperoxaluric rats with vitamin C supplement (group 4, n=7) and hyperoxaluric rats with vitamin E and C supplement (group 5, n=7). Hyperoxaluria was induced by feeding hydroxyl L-proline (HLP) 2% w/v dissolved in drinking water. Intraperitoneal 200 mg/kg of vitamin E was given in groups 3 and 5 on days 1, 6, 11 and 16, while 500 mg of vitamin C was injected intravenously in groups 4 and 5 on days 1 and 11. Renal functions and oxidative status were measured. The urinary oxalate excretion was increased in HLP supplement rats, while glomerular filtration rate, proximal water and sodium reabsorption were significantly lower in group 2 compared with a control (P<0.05). Giving antioxidants significantly lower urinary calcium oxalate crystals (P<0.05). Hyperoxaluric rats had higher plasma malondialdehyde (PMDA) and lower urinary total antioxidant status (UTAS), which were alleviated by vitamin E and/or vitamin C supplement. In conclusion, giving combination of vitamin E and vitamin C exerts a protective role against HLP-induced oxalate nephropathy.

Oxidative stress induces hypomethylation of LINE-1 and hypermethylation of the RUNX3 promoter in a bladder cancer cell line

Increased oxidative stress and changes in DNA methylation are frequently detected in bladder cancer patients. We previously demonstrated a relationship between increased oxidative stress and hypomethylation of the transposable long-interspersed nuclear element-1 (LINE-1). Promoter hypermethylation of a tumor suppressor gene, runt-related transcription factor 3 (RUNX3), may also be associated with bladder cancer genesis. In this study, we investigated changes of DNA methylation in LINE-1 and RUNX3 promoter in a bladder cancer cell (UM-UC-3) under oxidative stress conditions, stimulated by challenge with H2O2 for 72 h. Cells were pretreated with an antioxidant, tocopheryl acetate for 1 h to attenuate oxidative stress. Methylation levels of LINE-1 and RUNX3 promoter were measured by combined bisulfite restriction analysis PCR and methylation-specific PCR, respectively. Levels of LINE-1 methylation were significantly decreased in H2O2-treated cells, and reestablished after pretreated with tocopheryl acetate. Methylation of RUNX3 promoter was significantly increased in cells exposed to H2O2. In tocopheryl acetate pretreated cells, it was markedly decreased. In conclusion, hypomethylation of LINE-1 and hypermethylation of RUNX3 promoter in bladder cancer cell line was experimentally induced by reactive oxygen species (ROS). The present findings support the hypothesis that oxidative stress promotes urothelial cell carcinogenesis through modulation of DNA methylation. Our data also imply that mechanistic pathways of ROS-induced alteration of DNA methylation in a repetitive DNA element and a gene promoter might differ.

Calcium oxalate crystallization index (COCI): an alternative method for distinguishing nephrolithiasis patients from healthy individuals

Urinary supersaturation triggers lithogenic crystal formation. We developed an alternative test, designated calcium oxalate crystallization index (COCI), to distinguish nephrolithiasis patients from healthy individuals based on their urinary crystallization capability. The effect of urine volume, oxalate, phosphate, citrate, potassium, and sodium on COCI values was investigated. COCI values were determined in 24-hr urine obtained from nephrolithiasis patients (n=72) and matched healthy controls (n=71). Increases in urine oxalate and phosphate and decreases in urine volume and citrate resulted in significantly increased COCI values. The urinary COCI in nephrolithiasis patients was significantly higher than that in healthy individuals. Two healthy subjects who had elevated COCI values were found to have asymptomatic kidney calculi. The receiver operating characteristic analysis showed an area under the curve of the urinary COCI test of 0.9499 (95%CI: 0.9131-0.9868) for distinguishing between nephrolithiasis and healthy subjects. At the cutoff of 165 mg oxalate equivalence/day, the urinary COCI test provided sensitivity, specificity, and accuracy amounts of 83.33%, 97.18%, and 90.21%, respectively. Urinary COCI values were primarily dependent on urine volume, oxalate, and phosphate. The test provided high sensitivity and specificity for clinically discriminating nephrolithiasis patients from healthy controls. It might be used to detect individuals with asymptomatic kidney calculi.

Inflammatory and fibrotic proteins proteomically identified as key protein constituents in urine and stone matrix of patients with kidney calculi

To uncover whether urinary proteins are incorporated into stones, the proteomic profiles of kidney stones and urine collected from the same patients have to be explored. We employed 1D-PAGE and nanoHPLC-ESI-MS/MS to analyze the proteomes of kidney stone matrix (n=16), nephrolithiatic urine (n=14) and healthy urine (n=3). We identified 62, 66 and 22 proteins in stone matrix, nephrolithiatic urine and healthy urine, respectively. Inflammation- and fibrosis-associated proteins were frequently detected in the stone matrix and nephrolithiatic urine. Eighteen proteins were exclusively found in the stone matrix and nephrolithiatic urine, considered as candidate biomarkers for kidney stone formation. S100A8 and fibronectin, representatives of inflammation and fibrosis, respectively, were up-regulated in nephrolithiasis renal tissues. S100A8 was strongly expressed in infiltrated leukocytes. Fibronectin was over-expressed in renal tubular cells. S100A8 and fibronectin were immunologically confirmed to exist in nephrolithiatic urine and stone matrix, but in healthy urine they were undetectable. Conclusion, both kidney stones and urine obtained from the same patients greatly contained inflammatory and fibrotic proteins. S100A8 and fibronectin were up-regulated in stone-baring kidneys and nephrolithiatic urine. Therefore, inflammation and fibrosis are suggested to be involved in the formation of kidney calculi.

Fibrosis and evidence for epithelial-mesenchymal transition in the kidneys of patients with staghorn calculi

OBJECTIVES

• To quantify fibrotic lesions in renal tissues obtained from patients with large calculi and to evaluate association with renal function. • Presence of epithelial-mesenchymal transition (EMT) in stone-containing renal tissues was investigated.

PATIENTS, SUBJECTS AND METHODS

• In all, 50 patients with nephrolithiasis with large calculi and matched healthy controls (37) were recruited. • Plasma creatinine (Cr) and corrected Cr clearance (CCr) were determined in all subjects. • Of the 50 patients, 38 had renal tissue available for histological analysis. Fibrosis was assessed by Masson's trichrome staining. Co-expression of epithelial cytokeratins and mesenchymal markers [α-smooth muscle actin (αSMA) and vimentin] in renal tubular cells was detected by dual immunofluorescence staining. • Expression of fibronectin, transforming growth factor β₁ (TGF-β₁) and CD68 were investigated.

RESULTS

• Overall, the kidney function of the patients was significantly reduced, indicated by increased plasma Cr and decreased corrected CCr compared with healthy controls. • Inflammation grading in renal tissues of the patients was correlated with the percentage of the fibrotic area. Renal fibrosis was inversely correlated with renal function. • Cytokeratins co-expressed with αSMA and vimentin were found in nephrolithiatic renal tubular cells, and these cells strongly expressed fibronectin and TGF-β₁. • Infiltration of CD68-positive cells was a common finding in the inflamed renal sections.

CONCLUSIONS

• Kidneys of large stone-forming patients had robust signs of inflammation and fibrosis, and there was a close correlation of renal fibrosis with renal dysfunction. • This is the first study to show evidence for renal tubular cells showing signs of EMT in large stone-containing kidneys. Plausibly, TGF-β₁ triggers EMT, which at least in part contributes to large stone-induced renal fibrosis.

Lithogenic activity and clinical relevance of lipids extracted from urines and stones of nephrolithiasis patients

We investigated contents and classes of urinary and stone matrix lipids, and evaluated their clinical relevance in nephrolithiasis patients. Lithogenic role of major lipid classes was explored. Urine (24 h) and stone samples were collected from 47 patients with nephrolithiasis. Control urines were obtained from 29 healthy subjects. Urinary 8-hydroxy-deoxyguanosine (8-OHdG), malondialdehyde (MDA), N-acetyl-β-glucosaminidase (NAG) activity and total proteins were measured. Total lipids were extracted from centrifuged urines (10,000 rpm, 30 min) and stones by chloroform/methanol method. Major classes of lipids were identified using multi-one-dimensional thin-layer chromatography (MOD-TLC). Influence of each lipid class purified from stone matrices on stone formation was evaluated using crystallization and crystal aggregation assays. Urinary NAG activity and 8-OHdG were significantly elevated in nephrolithiasis patients. Total lipids in centrifuged urines of the patients were not significantly different from that of controls. In nephrolithiasis, urinary excretion of total lipids was linearly correlated to urinary MDA, 8-OHdG, NAG activity and total proteins. Lipid contents in stone matrices varied among stone types. Uric acid stone contained lower amount of total lipids than calcium oxalate and magnesium ammonium phosphate stones. MOD-TLC lipid chromatograms of healthy urines, nephrolithiasis urines and stone matrices were obviously different. Triacylglyceride was abundant in urines, but scarcely found in stone matrices. Stone matrices were rich in glycolipids and high-polar lipids (phospholipids/gangliosides). Partially purified glycolipids significantly induced crystal aggregation while cholesterol was a significant inducer of both crystal formation and agglomeration. In conclusion, total lipids in centrifuged urines did not differ between nephrolithiasis and healthy subjects. Our finding suggests that the significant sources of lipids in patients' urine may be large lipids-containing particles, which are removed in centrifuged urines. However, urinary lipid excretion in nephrolithiasis patients was associated with the extent of oxidative stress and renal tubular injury. Triacylglyceride was abundant in urines, but rarely incorporated into stones. Glycolipids were principal lipid constituents in stone matrices and functioned as crystal aggregator. Cholesterol purified from stone matrices bared crystal nucleating and aggregating activities.

Right ventricular electrocardiographic leads for detection of Brugada syndrome in sudden unexplained death syndrome survivors and their relatives

BACKGROUND

Sudden unexplained death syndrome (SUDS) is a sudden death syndrome in previously healthy Southeast Asian young adults without any structural causes of death. Many SUDS survivors show electrocardiographic (ECG) evidence of RSR' and ST elevation in leads V1 to V3, which is similar to the ECG pattern in Brugada syndrome. However, in many cases transient normalization of the ECG does not make diagnosis with standard 12-lead ECG possible.

HYPOTHESIS

To overcome this problem, we utilized the new right ventricular ECG leads to detect the Brugada syndrome in SUDS survivors.

METHODS

The subject was a Thai male patient who presented with a SUDS-like syncopal attack. He had cardiac arrest due to idiopathic ventricular fibrillation.

RESULTS

Post-resuscitation standard 12-lead ECG showed no diagnostic features of Brugada syndrome. However, ECG patterns of RSR' and ST elevations typical for Brugada syndrome could be detected at the higher intercostal space leads V1 to V3. We observed similar findings in 2 of the other 10 SUDS survivors and 4 of 23 healthy family members.

CONCLUSIONS

Our data suggest that these new right ventricular leads ECG may be helpful in detecting Brugada syndrome in SUDS survivors and their relatives.

Messenger RNA expression of monocyte chemoattractant protein-1 and interleukin-6 in stone-containing kidneys

OBJECTIVES

To investigate the intrarenal mRNA expression of monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) in patients with nephrolithiasis, and to evaluate whether their expression is associated with renal function, as oxidative stress and inflammation are involved in the pathogenesis of nephrolithiasis.

PATIENTS, SUBJECTS AND METHODS

Renal biopsies from near the stone, and blood and 24-h urine specimens were collected from 29 patients with nephrolithiasis. Control renal tissues were taken from non-cancerous and cancerous portions of nephrectomy from six patients with renal cancers, and control 24-h urine samples were obtained from 30 healthy subjects. Corrected creatinine clearance, urinary N-acetyl-beta-glucosaminidase activity and 8-hydroxy-deoxyguanosine (8-OHdG) were determined. The mRNA expressions of MCP-1 and IL-6 in the tissues were measured by real time reverse transcription-polymerase chain reaction.

RESULTS

Patients with nephrolithiasis had significantly greater renal tubular damage and oxidative stress than the healthy controls. Intrarenal mRNA expressions of MCP-1 and IL-6 in stone-adjacent renal tissues were significantly lower than in cancerous renal tissues, but not statistically different from that in non-cancerous renal tissues. In stone-adjacent renal tissues, the mRNA level of MCP-1 was significantly higher than that of IL-6, but their expressions were significantly correlated with each other. Histological examination showed that the number of infiltrated leukocytes corresponded well with the intrarenal mRNA levels of MCP-1 and IL-6. Patients with nephrolithiasis and compromised renal function had significantly higher intrarenal mRNA levels of MCP-1 and IL-6 than those with preserved renal function. Also, the mRNA levels in patients with severe renal tubular damage were significantly greater than in those with less renal tubular damage. There was no association between intrarenal mRNA expression and urinary 8-OHdG.

CONCLUSION

Nephrolithiasis was associated with low-grade intrarenal inflammation. A greater intrarenal mRNA expression of MCP-1 and IL-6 was associated with enhanced renal impairment. Thus, expression of MCP-1 and IL-6, at least in part, contributed to the progression of nephrolithiasis.

Estimation of blood loss in transurethral resection of prostate (TUR-P) by urine-strip

OBJECTIVES

Blood loss in transurethral resection ofprostate (TUR-P) operation is estimated by the difference between pre- and post-operative hemoglobin (Hb) concentration. The authors introduced a novel practical method to estimate blood loss in the patients who were surgically managed with TUR-P operation.

MATERIAL AND METHOD

Complete blood count was collected pre-operative, immediate post-operative, and 24-hour post-operative to determine red blood cells and Hb concentration. Hemoglobin of irrigating fluid was measured by standard spectrophotometry and blood loss was estimated by the authors' calculation. Irrigating fluid was frozen and thawed to completely hemolyse the red blood cells, then it was tested by urine-strips and calculated for red cells using estimating cell ranges given by the product's prescription. The correlation between these indicators was evaluated.

RESULTS

Calculated blood loss detected by spectrophotometric method has no correlation with immediate post-operative or 24-hour post-operative Hb concentration. However, it had a significant positive correlation with calculated blood loss by urine-strip technique (r = 0.897, p = 0.01).

CONCLUSION

Urine-strip method can be used to estimate total blood loss in irrigating fluid in patients with TUR-P operation. This is practical and useful in immediate post-operative evaluation of blood loss to consider the need of blood transfusion.

Urinary 8-hydroxydeoxyguanosine is elevated in patients with nephrolithiasis

8-hydroxydeoxyguanosine (8-OHdG) is an oxidatively modified guanosine, which has been widely used as an oxidative DNA damage marker in various diseases. The present study aimed to determine urinary 8-OHdG in nephrolithiasis patients and evaluate its clinical significance. Thirty-six nephrolithiasis patients and 30 healthy subjects were recruited. Urine volume, creatinine, malondialdehyde, beta-N-acetylglucosaminidase (NAG) activity and proteins were measured in 24 h urine samples. Urinary 8-OHdG was determined by competitive enzyme-linked immunosorbent assay. Mineral composition of stones was analyzed using Fourier-transformed infrared spectroscopy. Nephrolithiasis patients excreted urinary 8-OHdG significantly higher than healthy controls. Urinary 8-OHdG levels compared among patients with calcium oxalate, struvite and uric acid stones were insignificantly different. The urinary NAG activity correlated positively with urinary 8-OHdG. Multiple linear regression showed that urinary NAG activity was an independent predictor of urinary 8-OHdG level. Receiver operating characteristic analysis revealed that the urinary 8-OHdG test was adequate for diagnosing nephrolithiasis. At 10 mug/g creatinine cutoff, the 8-OHdG test imparted high specificity (96.67%) and a positive predictive value (91.67%). In conclusion, this is the first report of elevated urinary 8-OHdG excretion in nephrolithiasis patients indicating increased oxidative DNA damage. Increased renal tubular damage was independently associated with elevated urinary 8-OHdG. Elevated urinary 8-OHdG levels adjunct with metabolic profile may be useful for identifying people at risk of stone development.

Environmental tobacco smoke exposure and respiratory syncytial virus infection in young children hospitalized with acute lower respiratory tract infection

OBJECTIVE

The present study was performed to determine the relationship between environmental tobacco smoke (ETS) exposure and acute lower respiratory tract infection (LRI) caused by respiratory syncytial virus (RSV) in children.

MATERIAL AND METHOD

The authors did the study in 71 children (median age 12 months; 60% male) who were admitted to King Chulalongkorn Memorial Hospital with acute LRI between June and September 2004. 27% had RSV infection.

RESULTS

RSV-LRI required longer duration of oxygen therapy than non RSV-LRI (4.5 +/- 1.7 vs 2.8 +/- 1.3 days; p < 0.001). Desaturation in room air was more common in the former group compared to the latter group (37 vs 11%; p = 0.01). There was no difference in urinary cotinine level between the two groups (median 0.5 vs 0.6 mcg/mg Cr; ns). Among RSV-LRI, those with desaturation had higher urinary cotinine level than those without desaturation (median 0.8 vs 0.0 mcg/mg Cr; p = 0.04).

CONCLUSION

ETS exposure was not associated with RSV-LRI but increased the risk of desaturation in these patients.

Effects of the etonogestrel-releasing implant Implanon® and a nonmedicated intrauterine device on the growth of breast-fed infants

The study objectives were to compare the effects of an etonogestrel-releasing implant (Implanon) and a nonmedicated intrauterine device (IUD) on parameters of lactation in breast-feeding women and on the growth of their breast-fed infants over a 3-year period. Healthy lactating women (28-56 days postpartum) chose either the implant (n=42) or the IUD (n=38). Infant growth during a 3-year follow-up period is reported here. Total duration of breast-feeding coinciding with the mothers' treatment was 421.0 and 423.4 days in the Implanon and IUD groups, respectively. There were no differences between the infant groups in terms of body length, biparietal head circumference and body weight. No abnormalities were reported in psychomotor development or during physical examination. No treatment-related side effects were observed in either group. In conclusion, there were no differences in the growth of breast-fed infants of women treated with Implanon or a nonmedicated IUD. Implanon, therefore, appears to be a safe contraceptive option for breast-feeding women and their infants.

The benefits of vitamin C and vitamin E in children with beta-thalassemia with high oxidative stress

The present study aimed to determine the benefits of vitamin C and vitamin E as antioxidant supplements in beta-Thalassemia children who are at risk of iron overload due to multiple blood transfusion and high oxidative stress. Antioxidant status, oxidative products, plasma free hemoglobin, total hemoglobin and bilirubin were discussed. Twenty children who had laboratory confirmation of major beta-Thalassemia at least 6 months with history of packed red cell transfusion without iron chelation were recruited. The informed consent for blood sample collection and antioxidant medication was performed. Most patients (85%) had hyperferritinemia and all of them had high oxidative stress. All of them had low vitamin C and vitamin E level at recruitment. Three months after vitamin C and vitamin E supplementation, plasma vitamin C, vitamin E and glutathione were significantly increased, while total bilirubin was slightly decreased without significance. Other parameters included total antioxidant status (TAS), plasma and erythrocyte malondialdehyde (MDA), hemoglobin and plasma free hemoglobin had no differences during the study period.

CONCLUSION

B-Thalassemia major children who had multiple blood transfusion are at risk in iron overload and high oxidative stress. From the present study, no significant improvement in raising hemoglobin and concerning low dose vitamin C is not contraindication in beta-Thalassemia patients. Therefore, vitamin C plus vitamin E supplementation have benefits more than vitamin E alone in promoting antioxidant status and may enhance liver function as total bilirubin tends to decrease.

Effects of potassium-magnesium citrate supplementation on cytosolic ATP citrate lyase and mitochondrial aconitase activity in leukocytes: A window on renal citrate metabolism

BACKGROUND

An increase in urinary citrate excretion is associated with a decrease in activity of renal cortical cytosolic ATP citrate lyase (ACL) and mitochondrial aconitase (m-aconitase). Because potassium-magnesium citrate causes an increase in urinary citrate excretion, we decided to assess its effects on ACL and m-aconitase in the leukocytes of renal stone patients.

METHODS

Twenty male renal stone patients were supplemented with potassium-magnesium citrate twice daily (i.e. 42 mEq potassium, 21 mEq magnesium, and 63 mEq citrate per day) for a period of 1 month. Two 24-h urine and one 15-mL heparinized blood samples were collected from each patient before and after supplementation. Urine samples were analyzed for relevant biochemical compositions. Leukocytes were separated from blood samples by centrifugation and assayed for ACL and m-aconitase activity.

RESULTS

Supplementation with potassium-magnesium citrate significantly increased urinary pH (P < 0.005) and excretions of potassium (P < 0.001), magnesium (P < 0.001) and citrate (P < 0.0001). The activity of both ACL and m-aconitase were significantly decreased (P < 0.004 and P < 0.02 respectively). The decrease in ACL activity was inversely correlated with an increase in urinary excretion of both potassium (r = -0.620, P < 0.0001) and citrate (r = -0.451, P < 0.004). A similar inverse correlation was observed between m-aconitase activity and urinary excretion of citrate (r = -0.322, P < 0.043).

CONCLUSION

Changes in enzyme activity, related to citrate metabolism in leukocytes, might reflect the status of renal tubular cells.

Changes in erythrocyte contents of potassium, sodium and magnesium and Na, K-pump activity after the administration of potassium and magnesium salts

Low potassium and magnesium status and decreased Na, K-pump activity is an endemic condition among rural Northeast Thais. The authors examined the effect of supplementing potassium and magnesium on erythrocyte potassium, sodium and magnesium content and on Na, K-pump activity. Rural Northeast Thai renal stone patients (62) were recruited, divided into four groups and supplemented for one month with potassium chloride (Group1, n = 16), potassium-sodium citrate (Group2, n = 15), chelated magnesium (Group 3, n =16) and potassium-magnesium citrate (Group 4, n =15) in order to achieve 40 mmol potassium, 10 mmol magnesium and 60 mmol citrate daily. After supplementation with potassium (Groups 1, 2 and 4), plasma potassium and Na, K-pump activity rose significantly in Groups 1, 2 and 4, but erythrocyte potassium rose only in Groups 2 and 4. When supplementing elemental magnesium (Groups 3 and 4), the chelated magnesium caused a significant increase in plasma potassium, erythrocyte potassium, sodium and magnesium without a significant increase in Na, K-pump activity. By contrast, potassium-magnesium citrate caused a significant increase in erythrocyte potassium and magnesium and Na, K-pump activity, but depressed erythrocyte sodium. These results suggest the forms of potassium and /or magnesium salts being supplemented should be considered because they affect erythrocyte potassium, sodium and magnesium content and Na, K-pump activity differently.

Renal tubular cell damage and oxidative stress in renal stone patients and the effect of potassium citrate treatment

Our objective was to evaluate the oxidative stress and renal tubular cell damage in patients who have renal stones compared to normal subjects. The patients were re-evaluated after 1-months supplementation with potassium citrate. We recruited 30 patients (11 males and 19 females) diagnosed with kidney stones and scheduled for surgical stone removal the following month, and 30 healthy non-stone formers (14 males and 16 females). Two 24-h urine samples and one heparinized blood sample were collected from each subject. Plasma was separated from the erythrocytes and assayed for creatinine, potassium, sodium, calcium, magnesium, phosphate, malondialdehyde (MDA, a lipid peroxidation product) (P-MDA), protein thiol as an indicator of protein oxidation, and vitamin E. Erythrocytes were analysed for MDA (E-MDA), reduced glutathione (GSH) and cellular glutathione peroxidase (cGPx) activity. The urine was analyzed for pH, creatinine, potassium, sodium, calcium, magnesium, phosphate, oxalate, citrate, MDA (U-MDA), total protein (U-protein) and N-acetyl-beta-glucosaminidase (NAG) activity. For the stone patients, urine and blood samples were re-evaluated after supplementation with potassium citrate (60 mEq/day) for 1 month. Renal stone patients had higher plasma creatinine and lower plasma potassium, urinary pH, potassium, magnesium, phosphate and citrate than the controls. The patients had higher P-MDA, E-MDA, U-MDA, U-protein and NAG activity, but lower GSH, cGPx activity, protein thiol and vitamin E, when compared with controls. After potassium citrate supplementation, P-MDA and E-MDA decreased while plasma vitamin E, urinary NAG activity and citrate increased. Renal stone disease is associated with high oxidative stress and damage to renal tubular cells. These abnormalities are coincident with an increase in blood lipid peroxidation products and a decrease in antioxidant status. Although supplementation with potassium citrate improved urinary citrate levels and oxidative stress, it neither reduced urinary lipid peroxidation products nor remedied the damage to renal tubular cells, probably due to the existence of kidney stones.

Oxidative stress from rapid versus slow intravenous iron replacement in haemodialysis patients

METHODS AND RESULTS

Oxidative stress was examined in 19 erythropoietin-treated haemodialysis patients who were receiving 100 mg of iron sucrose every 2 weeks by two intravenous methods, rapid injection and slow infusion. There were no significant differences in incidence of iron oversaturation state between the two methods. Regarding oxidative stress markers, the values of plasma and red blood cell thiobarbituric acid reactive substances (TBARS) expressed in terms of malonyldialdehyde (MDA) equivalents following the two methods did not increase, and the values of area under the curve (AUC) of both markers were not different between both regimens. Also, there were no significant differences in the values of plasma and AUC of anti-oxidant markers including total anti-oxidant status, reduced thiols, and vitamin E among both periods treated with two intravenous iron methods.

CONCLUSION

As such, both intravenous iron methods could be safely used without enhancing oxidative stress in haemodialysis patients. The rapid injection method would be the preferred method of intravenous iron administration because it is more convenient while still retaining the safety profile.

The effects of potassium and magnesium supplementations on urinary risk factors of renal stone patients

The effects of potassium and magnesium supplementation on urinary risk factors for renal stone disease were studied in 61 renal stone patients. The subjects were divided into four groups and supplemented for a period of one month with potassium chloride (KCl, Group 1), potassium sodium citrate (K Na citrate, Group 2), magnesium glycine (Mg glycine, Group 3) and potassium magnesium citrate (K Mg citrate, Group 4) with a daily dose of 42 mEq potassium, 21 mEq magnesium or sodium and 63 mEq citrate, accordingly. The results showed that serum potassium and magnesium of all four groups normalized after the supplementation. Though urinary potassium significantly increased in all three groups supplemented with elemental potassium containing solutions [i.e. KCl (p < 0.001), K Na citrate (p < 0.001) and K Mg citrate (p < 0.001)] only K Na citrate and K Mg citrate, caused a significant increase in urinary pH and citrate but decrease in calcium. Supplementation with Mg glycine in Group 3 although caused a significant increase in urinary magnesium, its effects on urinary pH, citrate and calcium, however, were similar to KCl, in that they caused a significant decrease in urinary pH without any change in urinary citrate or calcium. Supplementation with K Mg citrate in Group 4 seems to have given the best results, as far as lowering stone risk factors in that it caused an increase in urinary pH, potassium and citrate and decreased calcium excretions similar to K Na citrate in Group 2. In addition, K Mg citrate also caused the enrichment of urine with magnesium, another inhibitor of calcium-containing stones. Although the four supplements had no effect on urinary saturation of calcium oxalate salt, their effects on the saturations of brushite (CaHPO4 x 2H2O), octacalcium phosphate (Ca8H2 (PO4)6 x 5H2O) and uric acid were clearly associated with changes in urinary pH. Therefore, in Group 1 and 3, subjects having a decrease in urinary pH, also experienced a significant increase in uric acid saturation. Though the saturation of brushite and octacalcium phosphate in Group 2 and 4 and the sodium acid urate in Group 2 were significantly increased, these urinary risk factors could be overcome, however, by the concomitant increase in urinary citrate. The present results demonstrate that for those stone vulnerable subjects having a high risk of potassium and magnesium depletion, to obtain the best therapeutic results, they should be provided supplementations of both potassium and magnesium together and also in the forms that would result in the delivery of an alkali loading effect.

The correlation between markers of oxidative stress and risk factors of coronary artery disease in Thai patients

An imbalance between oxidative damage and antioxidative protection in association with the pathophysiology of atherosclerosis has been suggested. The aim of our study was to investigate the relationship between plasma lipids, the antioxidant system and oxidative damage in Thai patients with stable coronary artery disease (CAD). Sixty-one patients (40 males, 21 females), who were angiographically defined as having CAD and were clinically stable, participated in this study. Thirty-two healthy subjects (20 males, 12 females) served as normal controls. The investigation included the measurements of plasma lipid profiles and plasma total antioxidative status (TAS) such as plasma vitamin E erythrocyte glutathione (GSH) and glutathione peroxidase (GPx), as well as malondialdehyde (MDA) and total plasma total protein thiols (P-SH). In patients with CAD, erythrocyte GSH and GPx were significantly lower than those found in controls. However plasma TAS and vitamin E were not significantly different between groups. Patients with CAD also had higher MDA and lower P-SH levels than the controls, which represents the oxidative damage products of lipid and proteins. Multiple regression analysis revealed negative correlations between GSH and cholesterol, GSH and low density lipoprotein (LDL), vitamin E and MDA, as well as P-SH and MDA. This study demonstrated the status of oxidative stress in patients with stable CAD. Since oxidative stress is the imbalance between the total oxidants and antioxidants in the body, any single oxidant/antioxidant parameter may not reflect the overall oxidative stress system. Thus, in patients with CAD, diets with various types of antioxidants may be more beneficial in increasing antioxidant activity than any particular antioxidant supplementation.

Treatment of glomerular endothelial dysfunction in steroid-resistant nephrosis with Ganoderma lucidum, vitamins C, E and vasodilators

Glomerular endothelial dysfunction is believed to be responsible for the proteinuria and nephronal damage, namely tubulointerstitial fibrosis and glomerulosclerosis, observed in severe nephrosis such as focal segmental glomerulosclerosis. A dysfunctioning glomerular endothelium is likely to be induced by oxidative stress and oxidized LDL as well as altered immunocirculatory balance with a defective anti-inflammatory pathway. A defective release of vasodilator inconjunction with enhanced production of angiotensin II induces hemodynamic maladjustment by preferential constriction at the efferent arteriole. Such a hemodynamic maladjustment exerts two significant hemodynamic impacts. Close to the efferent constriction, it induces intraglomerular hypertension and glomerulosclerosis. Far from the efferent constriction, it reduces peritubular capillary flow, which eventually leads to tubulointerstitial fibrosis. Treatment with a vasodilator improves the hemodynamic maladjustment but does not completely suppress proteinuria. A successful suppression of proteinuria is accomplished by using Ganoderma lucidum and vitamins C and E. The beneficial effect of Ganoderma lucidum appears to be multifactorial, including the modulation of immunocirculatory balance, antilipid, vasodilator, antiplatelet and improved hemorheology. Together with vitamins C and E, this helps to neutralize oxidative stress and suppress the toxic effect to the glomerular endothelial function.

Short-term effects of an intensive lifestyle modification program on lipid peroxidation and antioxidant systems in patients with coronary artery disease

The purpose of this study was to compare the short-term effects of an intensive lifestyle modification (ILM) program on lipid peroxidation and antioxidant systems in patients with coronary artery disease (CAD). Twenty-two patients in the control group continued to receive their conventional treatment with lipid-lowering drugs, whereas 22 patients in the experimental group were assigned to intensive lifestyle modification (ILM) without taking any lipid-lowering agent. The ILM program comprised dietary advice on low-fat diets, high antioxidants and high fiber intakes, yoga exercise, stress management and smoking cessation. After 4 months of intervention, patients in the experimental group revealed a statistically significant increase in plasma total antioxidants, plasma vitamin E and erythrocyte glutathione (GSH) compared to patients in the control group. There was no significant change in plasma malondialdehyde (MDA), a circulating product of lipid peroxidation, in either group. We concluded that the ILM program increased circulating antioxidants and reduced oxidative stress in patients with CAD.

Urinary citrate excretion in patients with renal stone: roles of leucocyte ATP citrate lyase activity and potassium salts therapy

BACKGROUND

Hypocitraturia is a major metabolic abnormality in rural Northeast Thais with renal stones. These people also have low serum and urinary potassium and consume a high carbohydrate and low fat diet, which together might influence the intracellular metabolism and urinary excretion of citrate.

METHODS

In Study A, we measured plasma and urinary chemistries and assayed leucocyte ATP citrate lyase (ACL) activity in 30 normal urban control subjects (Group A1) and 30 rural renal stone patients (Group A2) in Northeast Thailand. Some of the subjects from both groups were also used to evaluate the intake of carbohydrate, protein and fat. In Study B, we examined the effects of potassium salts therapy with another group of 30 rural renal stone patients: Group B1 (n = 15) treated with potassium chloride and Group B2 (n = 15) with potassium-sodium citrate (with an aim to achieve 42 mEq potassium, 21 mEq sodium and 62 mEq citrate per day for 1 month).

RESULTS

In Study A, the leucocyte ACL activity of Group A1 was much lower than that of Group A2 (3.2 +/- 0.7 vs. 9.3 +/- 3.8 micromol acetylhydroxamate/mg protein/30 min, p < 0.0001). The plasma potassium, urinary excretions of potassium and citrate in Group A1 were higher than in Group A2. When data of the two groups were combined, urinary citrate excretion was inversely correlated with leucocyte ACL activity (r = 0.6783, p < 0.001). While the dietary protein intake did not differ between Groups A1 and A2, the carbohydrate intake by Group A1 was significantly lower (65.2 +/- 7.9% vs. 83.1 +/- 2.9%, p < 0.01) and fat higher (21.0 +/- 6.4% vs. 6.2 +/- 4.1%, p < 0.002) than Group A2. After treatment with potassium chloride (Group B1), only the potassium was increased (p < 0.001), while those treated with potassium-sodium citrate (Group B2) experienced a significant increase in urinary pH (p < 0.002), potassium (p < 0.001) and citrate (p < 0.001), and a decrease in leucocyte ACL activity (p < 0.001).

CONCLUSIONS

Compared to normal subjects, renal stone patients have low urinary citrate excretion with high leucocyte ACL activity. In Northeast Thailand, low potassium status and a high carbohydrate and low fat diet may cause the increased ACL activity. However, hypokaliuria, hypocitraturia and high leucocyte ACL activity can be corrected by potassium-sodium citrate salt therapy.

Magnesium status of patients with renal stones and its effect on urinary citrate excretion

OBJECTIVES

To assess the magnesium status and its effect on urinary citrate excretion in patients with renal stones, as they have a low muscular magnesium content.

PATIENTS, SUBJECTS AND METHODS

Using a magnesium-tolerance test (0.1 mmol/L MgSO4/kg body weight, delivered intravenously), the magnesium status was assessed in 17 patients with renal stones from rural North-east Thailand, and in three groups of normal subjects from different environments (i.e. 17 from rural Central Thailand, 16 from urban and 14 from rural North-east Thailand). Participants with magnesium deficiency (magnesium retention > 50%) were supplemented with 300 mg chelated magnesium daily for 1 month and reassessed. Their urinary citrate excretion was also measured before and after supplementation.

RESULTS

Nine of the patients with renal stones were magnesium deficient, as were six normal subjects from the same area, whereas only one and two of the rural Central and urban North-east Thais had magnesium deficiency. The magnesium status of the 13 deficient subjects significantly improved (P = 0.003) after supplementation with chelated magnesium. The supplement also caused a significant increase in mean (sd) urinary citrate excretion, from 237.7 (173.1) to 361.3 (284.1) mg/day (P= 0.012).

CONCLUSIONS

These results indicate that magnesium deficiency is common among patients with renal stones in rural North-east Thailand, and that the probable cause is environmental. The increase in urinary citrate excretion after magnesium supplementation suggests that magnesium is important in renal stone formation, through its effect on citrate metabolism.

Oxidative stress and hemodynamic maladjustment in chronic renal disease: a therapeutic implication

Hemodynamic maladjustment with predominant constriction at the efferent arteriole has been encountered in a variety of clinical settings of glomerulonephropathy. In essence, it induces not only intraglomerular hypertension but also exaggeratedly reduces the peritubular capillary flow, which supplies the tubulointerstitial compartment. The hemodynamic maladjustment is believed to reflect a glomerular endothelial cell dysfunction. In this regard, oxidative stress and antioxidant defect are likely responsible for the glomerular endothelial dysfunction. Improvement in renal function was accomplished following the correction of oxidant and antioxidant imbalance with antioxidant therapy and vasodilators. Following such therapy, there was a correction in hemodynamic maladjustment with a decline in intraglomerular hydrostatic pressure and an increase in renal perfusion with a subsequent increase in renal functions namely creatinine clearance, glomerular filtration rate and a decline in FEMg.

Magnesium and zinc status in survivors of sudden unexplained death syndrome in northeast Thailand

Sudden Unexplained Death Syndrome (SUDS) is a major health problem in rural residents of Northeast Thailand. The cause of death in SUDS is suspected to be cardiovascular abnormalities. As magnesium (Mg) and zinc (Zn) deficiency contribute significantly to several cardiovascular diseases, we investigated the Mg- and Zn-status of patients with sudden respiratory distress and cardiac arrest who had survived resuscitation attempts or a near-SUDS episode (N-SUDS). The following subjects were enrolled: 12 N-SUDS inhabitants of rural Northeast Thailand (rural group 1, R1), 13 rural villagers with no past history of N-SUDS (rural group 2, R2), 15 urban Northeasterners (urban group 1, U1); 13 Bangkokians (urban group 2, U2). All subjects were free of structural heart disease. Magnesium and zinc were assessed by atomic absorption spectrophotometry of samples of plasma, red blood cells (RBC), white blood cells (WBC), and 24-hour urine. The mean levels of magnesium in the RBC, WBC, and 24-hour urine of N-SUDS patients (R1) were significantly lower than those of the urban groups (U1 and U2), while the plasma levels did not show any differences. When comparing the Zn-status of R1 with that of the urban groups (U1 and U2), the plasma, RBC, and WBC levels were found to be significantly lower in R1 (except for the RBC-Zn of the U1 group), while the 24-hour urine levels was higher. Although the magnesium and zinc parameters were not significantly different between the rural groups R1 and R2, the prevalence of hypomagnesuria (<2.2 mmol/day), hypozincemia (<9.7 micromol/l), and hyperzincuria (>10.7 micromol/day) was higher in the R1 group. These findings suggest that the homeostasis of both magnesium and zinc is altered in N-SUDS patients. Similar alterations, to a lesser degree, were observed in those people living in the same rural environment (R2).

New electrocardiographic leads and the procainamide test for the detection of the Brugada sign in sudden unexplained death syndrome survivors and their relatives

AIMS

Sudden unexplained death syndrome occurs in previously healthy South-east Asian young adults without any structural cause of death. The common electrocardiographic (ECG) change in sudden unexplained death syndrome survivors is right bundle branch block and ST elevations in leads V(1) to V(3), which are similar to the ECG pattern in the Brugada syndrome (Brugada sign). It is difficult to diagnose the Brugada sign with the 12-lead ECG in sudden unexplained death syndrome survivors and their family members because the ECG could be transiently normalized. We proposed using the higher intercostal space V(1) to V(3) lead ECG, together with procainamide to detect the Brugada sign.

METHODS AND RESULTS

Among 20 ventricular fibrillation cardiac arrest patients, 13 sudden unexplained death syndrome survivors and their relatives (n=88) were studied using the single standard 12-lead ECG and the new six higher intercostal space V(1) to V(3) lead ECG (-V(1) to -V(3) and -2V(1) to -2V(3)). Ten sudden unexplained death syndrome survivors and relatives (n=48) who had a normalized ECG were also infused with procainamide (10 mg x kg(-1)i.v.) to unmask the Brugada sign and both ECG methods were recorded. Forty healthy individuals and 13 spouses served as the control group. Prior to the procainamide infusion, the Brugada sign could be detected in nine sudden unexplained death syndrome survivors (69.2%) and three (3.4%) relatives with the standard ECG and in 12 (92.3%) and nine (10.2%) with the new six-lead ECG. After the procainamide infusion, the Brugada sign could be demonstrated in seven sudden unexplained death syndrome survivors (70%) and seven (14.6%) relatives with the standard ECG and in nine (90%) (P=0.26) and 23 (47.9%) (P=0.0004) with the new six-lead ECG, respectively. All the controls were negative for the Brugada sign.

CONCLUSIONS

Our data suggest that the new higher intercostal space lead ECG, with or without the procainamide test is helpful in detecting the Brugada sign in sudden unexplained death syndrome survivors and their relatives.

Potassium status of Northeast Thai constructors in three different geographic locations

Sudden and unexpected death of young adults during sleep is a phenomenon among Southeast Asians and particularly young Northeast (NE) Thailand constructors in Singapore. Survivor of sudden unexplained death syndrome (SUDS) without structural heart disease with idopathic ventricular fibrillation (VF) has been documented. Low plasma potassium (K) and depletion of K can occur simply through a reduction of K intake and are associated with increased risk of VF. The K-status of the populations was evaluated in the NE (Group 1, n=30), Bangkok (Group 2, n=48) and Singapore (Group 3, n=46). Groups 2 and 3 were further subdivided into Group 2A (worked in Bangkok < or = 1 year, n=8), Group 2B (worked in Bangkok > 1 year, n=40), Group 3A (consumed self-prepared or ready-to-buy meals, n=25) and Group 3B (regularly consumed foods provided free-of-charge by construction companies, n=21). Thirty-four male healthy university personnels from the NE and Bangkok served as the control--Group 4. Two 24-h urine samples and a fasting blood sample were collected from each subject. Dietary-K from food was determined by duplicated meal analysis. All these samples were then analyzed for their K-content. Group 3A had the lowest K-status: their K-intake, serum-K, and urinary-K level were 29 +/- 5.8 mmol/day (% low K-intake=100), 3.43 +/- 0.34 mmol/L (% hypokalemia=48) and 19.23 +/- 8.2 mmol/day (% hypokaliuria=87.5), respectively. Among the construction workers, average K-intake, serum-K and urinary-K levels were 45.5 +/- 6.1 mmol/day (% low K-intake = 37.5), 3.93 +/- 0.2 mmol/L (% hypokalemia = 2.5) and 39.6 +/- 9.2 mmol/day (% hypokaliuria = 12.5), respectively. The values of Group 2B were similar to Group 4. In addition, when the data from all of the groups were compared, there was a positive correlation between dietary-K (intake) and urinary-K (excretion) (r=0.881, p<0.001). In conclusion, NE Thailand constructors from various locations exhibited low K status with low dietary-K, high incidence of hypokalemia, and low urinary-K. From the present study, this low K status may be an important trigger factor for VF in construction workers and associated with increase risk of SUDS.

Effects of the etonogestrel-releasing contraceptive implant (Implanon on parameters of breastfeeding compared to those of an intrauterine device

Eighty healthy single births born at a gestational age of 259-294 days were studied in an open, non-randomized, group comparative fashion. The mothers were on average 6 weeks postpartum, healthy, and fully breastfeeding at the start of treatment. Forty-two mothers elected to use the etonogestrel-releasing implant, Implanon, while 38 chose use of a non-hormone medicated intrauterine device (IUD). One month after implant placement, the dose of etonogestrel ingested by the infants via breast milk was 19.86 ng/kg/day, which decreased to 10.45 ng/kg/day at the end of the study period (month 4). The volume of breast milk production was not affected by the use of Implanon. There were no significant differences between groups in milk content of total fat, total protein, and lactose. The timing and quantity of supplementary feedings did not differ between the two groups. Growth of the infants was analyzed by treatment and gender. For the girls, no differences between groups were seen for body weight, body length, and head circumference. The same applied to the boys except for a somewhat larger, although not statistically significant, increase in body weight for boys whose mother used Implanon. There was a low incidence of intercurrent illnesses in the infants of both groups. None of the conditions was of a serious nature. From the present study, we conclude that Implanon did not change the volume and composition of breast milk. The low concentration of etonogestrel ingested by the infant was not associated with adverse effects.

A Thai boy with hereditary enzymopenic methemoglobinemia type II

Individuals with methemoglobin exceeding 1.5 g/dl have clinically obvious central cyanosis. Hereditary methemoglobinemia is due either to autosomal dominant M hemoglobins or to autosomal recessive enzymopenic methemoglobinemia. Four types of enzymopenic methemoglobinemia have been described. In addition to methemoglobinemia, individuals with type II, which is the generalized cytochrome b5 reductase deficiency, have severe and progressive neurological disabilities. Here we report a 3-year-old Thai boy with type II hereditary enzymopenic methemoglobinemia. He was born to a second-cousin couple. His central cyanosis was first observed around 10 months of age. His neurological abnormalities were seizures beginning at 1 year of age, microcephaly, and inability to hold his head up. His cardiovascular and pulmonary evaluations were unremarkable. Methemoglobin level by spectral absorption pattern was 18 per cent. A qualitative enzymatic assay confirmed the deficiency of the cytochrome b5 reductase enzyme. With this definite diagnosis, a prenatal diagnosis for the next child of this couple will be possible.

Potassium, sodium and magnesium contents in skeletal muscle of renal stone-formers: a study in an area of low potassium intake

Skeletal muscles surgically obtained from the stone-former group (external oblique muscle; n = 202, 82 males & 120 females), control group I (external oblique muscle; n = 5, all males), control group II (rectus abdominis muscle; n = 23, all females) and control group III (quadriceps femoris muscle; n = 11, all males) were analyzed for potassium (K), sodium (Na) and magnesium (Mg) contents. Muscle samples were digested with 65 per cent HNO3 and determined for K, Na and Mg by an atomic absorption spectrophotometer. The results of analysis showed the mean K, Na and Mg (+/- S.D.) contents in mumol per one gram of fresh tissue of the stone-former group, control groups I, II and III were 73.5 +/- 16.6, 51.3 +/- 13.4 and 6.6 +/- 1.3, 77.5 +/- 3.9, 43.9 +/- 9.9 and 7.2 +/- 0.5, 83.8 +/- 27.5, 49.4 +/- 24.1 and 6.7 +/- 1.8 and 85.0 +/- 17.1, 48.5 +/- 12.1 and 6.8 +/- 1.3. Among these variables, only the K content of control group III was higher significantly (p < 0.05) than that of the stone-former group. In the stone-former group, regression analysis showed significant correlations between K and Mg contents (r = 0.856, p < 0.001) and K and Na contents (r = -0.325, p < 0.001). Due to no available data of the external oblique, we made a comparison of our results to the soleus type of skeletal muscle of normal subjects reported by Dorup et al and found that the external oblique muscle had lower mean contents of K and Mg but a higher Na content than those of the soleus. Our results were similar to the K and Mg depleted muscles obtained from the patients receiving long-term treatment with diuretic drugs. The results suggest that most of our subjects in both the stone-former and the 3 control groups were in a state of K and Mg depletion. The causes may be multifactorial, for instance low intake, high sweat loss and the existence of environmental inhibitor (s) for K transport like vanadium.

Fast liver alkaline phosphatase isoenzyme in diagnosis of malignant biliary obstruction

Fast liver alkaline phosphatase isoenzyme was measured by cellulose acetate electrophoresis in the sera obtained from 84 patients with specific hepatobiliary diseases and 10 control subjects. The mean value of this isoenzyme in patients with malignant extrahepatic obstruction was 130.58 +/- 107.08 U/L, significantly higher than that of patients with benign extrahepatic obstruction (65.63 +/- 34.14 U/L), as well as patients with intrahepatic cholestasis and infiltrative liver cancers (65.31 +/- 38.11 U/L and 48.47 +/- 36.85 U/L, respectively). Furthermore, we could not detect this isoenzyme in normal individuals. When 100 U/L was used as a cut-off value to discriminate between patients with malignant extrahepatic obstruction and the remaining hepatobiliary disorders, the sensitivity, specificity and accuracy of the test were 63 per cent, 84 per cent and 80 per cent, respectively. It is concluded that the fast liver isoenzyme could be a useful marker in diagnosis of malignant extrahepatic obstruction.

Potassium needed for maintaining its balance in healthy male subjects residing in an area of low potassium intake and with a high environmental temperature

Low potassium (K) intake and high prevalence of hypokalemia and hypokaliuria among rural dewellers in the northeast region of Thailand have been repeatedly reported and they were speculated to be in a state of low K status. In this communication we studied K balance of 10 rural (R) and 5 urban (U) male subjects in this region during a 10-day period of semi-free-living and eating group-selected diets. While K in intake, 24-h urine and feces were measured daily in all subjects, the direct measurement of K lost in sweat was made only in one subject coded R3. These parameters were then used to calculate the K balance. The results showed that mean K intakes were 1731 +/- 138 and 1839 +/- 145 mg/day for R and U subjects, respectively. Their mean K balances, calculated by subtracting the K excretions in 24-h urine (721 +/- 129 mg/day for R and 919 +/- 186 mg/day for U) and in feces (148 +/- 25 mg/day for R and 164 +/- 21 mg/day for U) from intakes, were +860 +/- 140 and +756 +/- 222 mg/day for R and U, respectively. In the subject R3, his mean K balances without and with subtracting the sweat K excretion (451 +/- 57 mg/day), were +847 +/- 373 and +396 +/- 344 mg/day, respectively. Regression of K balance versus intake indicated that R and U subjects needed K of 832 and 884 mg/day to stay in balance. Since the study was performed during the hot season (average temperature = 35.2 +/- 2.0 degrees C at 3 pm) and sweating was clearly observed (estimated sweat volume per day was 1927 +/- 420 ml for R and 1759 +/- 408 ml for U), therefore, K balance calculated without sweat K was overestimated. This was apparently seen in the subject R3 where he actually needed K of 1203 mg/day, instead of 814 mg/day calculated without sweat K, to stay in balance. The similarities in K balance data among the two groups suggested they both had the same food habit and K status. Our results indicate that any calculation for the levels of dietary K, or probably also for other minerals, to achieve the balance could be underestimated if loss via sweat is not taken into consideration.

Environmental distal renal tubular acidosis in Thailand: an enigma

Distal renal tubular acidosis is a common health problem in northeastern Thailand, with the population background of the low potassium intake, low urine citrate, and decreased red blood cell Na-K adenosine triphosphatase (ATPase) activity and the environment of the high soil vanadium. The disease is usually seen in the people with low socioeconomic status in summer. The patients have decreased gastric acidity and low urine potassium. There are varying degrees of renal function from normal to impairment. Gastric hypoacidity is an important clue. Defects in H-K ATPase and anion exchange (AE2) mechanism are considered. The urine vanadium is higher in the patients than that of normal rural northeastern villagers. Inhibition of H-K ATPase by vanadium seems possible and requires more supporting evidence. AE1 gene mutation is noted in few patients. The cause of dRTA is not apparent. The AE2 gene and H-K ATPase gene remain to be studied. Both environmental and genetic factors could contribute to the pathogenesis of the disease.

Alpha-L-fucosidase as a serum marker of hepatocellular carcinoma in Thailand

To evaluate the role of serum alpha-L-fucosidase (AFU) in the diagnosis of hepatocellular carcinoma (HCC), we simultaneously studied both AFU activity and alpha-fetoprotein (AFP) level in 60 patients with HCC, 60 patients with cirrhosis and chronic hepatitis each, 30 patients with other liver tumors and 60 healthy subjects. Serum AFU activity in patients with HCC (1,418.62 +/- 575.76 nmol/ml/hr) was significantly higher than that found in cirrhosis (831.25 +/- 261.13 nmol/ml/hr), chronic hepatitis (717.71 +/- 205.86 nmol/ ml/hr) or other tumors (706.68 +/- 197.67 nmol/ml/hr) and in controls (504.18 +/- 121.88 nmol/ml/hr, p < 0.05). With 870 nmol/ml/hr (mean value of controls plus 3 standard deviations) considered as the cut-off point, AFU was more sensitive (81.7 vs 39.1%) but less specific (70.7 vs 99.3%) than AFP at a level of > 400 ng/ml as a tumor marker of HCC. With both markers combined, the sensitivity was improved to as much as 82.6%. AFU activity in HCC patients was correlated to tumor size (r = 0.3529, p = 0.006) but not associated with tumor staging classified by Okuda's criteria (p = 0.1). The AFU activity in the viral hepatitis group (hepatitis B or C) was also significantly higher than in the non-viral group (p = 0.0005). We conclude AFU to be a useful marker, in conjunction with AFP and ultrasonography, for detecting HCC, particularly in patients with underlying viral hepatitis and cirrhosis.

Potassium contents of northeastern Thai foods

From our previous nutritional assessment, low potassium (K) intake among northeastern Thai males has been clearly demonstrated. This prompted us to undertake a survey of the K content of local foods. Food samples comprised of 57 animal and 142 plant products which were collected from various places in the northeast of Thailand. The dry ashing method was used to prepare the samples for K analysis using an atomic absorption spectrophotometer. Foods could be divided into 7 groups according to their K levels. Foods containing K > or = 1000 mg per 100 g fresh food were categorized in group 1. These were mainly foods in the legume group, i.e., soybean, cowpea and mungbean. While rice (polished) and rice products, the main staple, were in group 7, the lowest K group of less than 100 mg per 100 g fresh food. Comparison studies of the natural foods between those collected from the northeast and from the central regions of the country, and between the cooked foods purchased from the rural villages and from the urban areas of Khon Kaen municipality, showed that, for most food items, the K content was similar wherever it came from. However, when the K content in various parts or in different stages of growth of the same kind of plants or animals was compared, a great variation was clearly seen, for example, young tamarind leaves contained K in group 6 whereas ripe tamarind fruit contained K in group 1. According to our food consumption data, the analysis of food components of 48 meals taken during the hot season by 13 rural volunteers revealed that food items eaten with the highest frequencies and in the largest amount were those in the low K food groups, i.e., glutinous rice (group 7) and green papaya (group 6). Our results suggest that the low K intake of these northeast rural Thai people is not due to a low K content of foods in this region, but rather that their food habits and low socioeconomic status restricts consumption of those food items with higher K contents.

Nutritional potassium status of healthy adult males residing in the rural northeast Thailand

Sixteen villages from rural areas of 8 provinces in the northeastern region of Thailand were randomly selected as study sites. Data on potassium (K) contents in 24-hour urine and serum samples of 93 healthy adult volunteer males aged 20-50 years old were completely collected and covered all 3 seasons of the year. The method of direct weighing of food was used to assess K intake in 13 subjects. K loss through sweat during working (9 hours) in the field was measured in 14 subjects by soaking their worn-clothes in distilled water after which K contents were measured by the flame photometry method. The results showed that the means urinary K excretion of 93 subjects were less than that of the cut-off value for normal (> or = 30 mmol/day) in all seasons of which 76.71%, 90.71% and 81.02% of the urine were categorized as hypokaliuria in the hot, rainy and cold seasons, respectively. In the case of serum K of these subjects, though the mean values were within a normal limit (> or = 3.5 mmol/l), 36.56%, 34.41% and 29.03% of the serum were classified as hypokalemia in the hot, rainy and cold seasons, respectively. In the assessment of K intake, it was clearly demonstrated that the values in all 3 seasons were much lower than that of the estimated safe and adequate daily dietary intake (ESADI) of K for the westerners (1975-5625 mg/day), i.e., the means of intake in the hot, rainy and cold seasons were only 807 +/- 172, 877 +/- 257 and 902 +/- 227 mg/day, respectively. Furthermore, K loss through sweat in the cold and the hot seasons were as high as a third (7.4 +/- 2.4 mmol/day) and a half (11.5 +/- 1.6 mmol/day), respectively, of the urinary excretion. Though the total body K contents were not evaluated in this study, our results suggest rural people in the northeast region of Thailand may be in a state of K deficiency. The severity is probably worsened in the hot season as seen from the tendency of decrease in serum K levels among 650 renal stone formers and 260 blood donors in this season.

Low erythrocyte Na/K-pump activity and number in northeast Thailand adults: evidence suggesting an acquired disorder

Healthy northeastern Thais have a higher erythrocyte sodium concentration and a lower erythrocyte membrane Na,K-adenosine triphosphatase (ATPase) activity than central Thais. To elucidate whether the defect is hereditary or acquired, we studied plasma sodium and potassium and erythrocyte sodium, potassium, Na,K-ATPase activity, and ouabain-binding sites (OBS) in the following groups: healthy newborns of ethnic central Thais (group 1), healthy newborns of ethnic northeast Thais (group 2), healthy adults of central Thailand ethnicity who lived in the rural central region (group 3) or in Bangkok (group 4), healthy adults of northeast Thailand ethnicity who lived in the rural northeast region (group 5) or who migrated to work in Bangkok for at least 1 year (group 6). Erythrocyte Na was higher in group 2 than in group 1. Group 3 had lower erythrocyte Na,K-ATPase activity than group 4, and it was lower in group 5 than in group 6. Among all groups, group 5 had the highest erythrocyte Na (11.6 mmol/L,F < 0.0001) and the lowest Na,K-ATPase activity (63 mmol Pi/mg x h, F < 0.0001) and erythrocyte OBS (397 sites per cell, F < 0.05) than the other adult groups. There was a positive correlation between erythrocyte Na,K-ATPase and erythrocyte OBS (r = .416, P < .0001). Multiple regression analysis demonstrated a correlation between erythrocyte Na as a dependent variable and erythrocyte OBS, plasma potassium, erythrocyte potassium, and erythrocyte Na,K-ATPase (r = .517, P < .0001). The erythrocyte Na,K-ATPase/OBS ratio, an expression of Na,K-ATPase activity equalized for the number of Na,K-pump units, was lowest among rural adults of the central region (group 3) and the northeast region (group 5) (F < 0.0002). Our data suggest that rural dwellers in Thailand tend to have lower erythrocyte Na,K-ATPase activity than urban dwellers and that this is probably acquired after birth. It was more severe among those from the northeast versus the central region, and was less severe among those who migrated to an urban area. This defect in northeast rural dwellers was probably associated with low numbers of Na,K-pump units and a defect of the pump to express activity, whereas in central rural dwellers it was probably associated with the latter condition. We postulate that there might be circulating Na,K-pump inhibitors and metabolic disturbances that cause attenuation of Na,K-ATPase function and synthesis in the northeast Thailand rural population, and that such substances may have an environmental origin. There may be a relationship between these abnormalities and sudden unexpected deaths.

Increased risk of urinary stone disease by physical exercise

Constituents of 6-hour (0900-1500 hours) urine collected during rest and exercise have been compared among 3 groups of male volunteers. Groups 1 and 2 (GI, GII) were normal controls residing in an urban area (n = 10) and rural villages (n = 9), respectively, and group 3 (GIII) consisted of 10 renal stone formers from the same location as GII. Exercise was performed by cycling on an electronic bicycle with three 150-watt loads and the duration of each load was 20 minutes. Collected usine was analyzed for volume, pH, PI (permissible increment) in oxalate, creatinine, calcium, sodium, potassium, phosphorus, oxalate, uric acid and citrate. The results showed that most urinary excretions during both rest and exercise periods were similar among the 3 groups. Only the following values were significantly different, ie in the rest period, calcium of GIII < GII (p < .01) and potassium of GII < GI (p < .05); in the exercise period, potassium of GIII < GI (p < .02) and phosphorus of GIII < GII (p < .03). In comparison between the rest and exercise periods within each group, the decreased total excretions during exercise were creatinine of GI (p < .05) and GIII (p < .05), calcium of GII (p < .05) and phosphorus of GIII (p < .05); only calcium of GIII (p < .05) was increased. However, when the concentration of each constituent was taken into consideration, most constituents increased in concentration during the exercise period due to the fall in urinary volume. Furthermore, during exercise both pH and PI in oxalate of urine decreased significantly. Thus the results of our study suggested that though most total urinary excretion patterns were similar between the rest and exercise periods, the risk of stone formation in the urinary tract during exercise could be enhanced. The enhanced risk is likely due to 3 main factors, ie (1) decrease in urinary volume, (2) increased propensity for crystallization of calcium oxalate (PI in oxalate decreased) and (3) decrease in urinary pH which will directly cause an increase in saturation level of uric acid. This increased risk of stone formation was consistently observed in all three groups of subjects.

Hypokalemia, high erythrocyte Na+ and low erythrocyte Na,K-ATPase in relatives of patients dying from sudden unexplained death syndrome in north-east Thailand and in survivors from near-fatal attacks

The sudden unexplained death syndrome (SUDS) is a sudden death of unknown cause in healthy South-East Asians. In Thailand, it is common in the North-East region. We previously reported high incidences of low erythrocyte sodium and potassium-activated adenosine triphosphatase (Na,K-ATPase) activity and of high erythrocyte sodium in North-East Thais and speculated that this metabolic defect might be associated with the high incidence of SUDS in that region. In this communication, we studied plasma sodium and potassium, erythrocyte sodium and potassium, activities of erythrocyte Na,K-ATPase, ouabain-insensitive ATPase and total ATPase in healthy Thai blood donors from Central Thailand (group 1), healthy North-East city dwellers (group 2), relatives of SUDS victims (group 3) and survivors from SUDS-like attacks (group 4). Compared with groups 1 and 2, group 3 and 4 subjects had significantly lower plasma potassium (p < 0.0001), higher erythrocyte sodium (p < 0.0001), lower activities of erythrocyte Na,K-ATPase (p < 0.0001) and of erythrocyte total ATPase (p < 0.0001). In addition, group 4 subjects had lower plasma potassium, higher erythrocyte sodium and lower activity of total ATPase than those of group 3. The findings suggest that the pathogenesis of SUDS could be related to hypokalemia and a membrane sodium/potassium pump defect.

Seasonal changes in serum and erythrocyte potassium among renal stone formers from northeastern Thailand

Hypocitraturia, hypokalemia and low urinary excretion of potassium are common findings in nephrolithiasis in Northeastern Thailand. However, intracellular potassium has not been studied. We measured serum potassium, erythrocyte potassium, 24-hour urinary excretion of sodium, potassium, citrate, ammonium, titratable acid and pH in 17 nephrolithiasis patients from Northeastern Thailand during 2 seasons: the cool and hot months. There were no significant differences in urinary pH, ammonium, titratable acid, citrate and potassium during these 2 seasons. However, hypocitraturia and hypokaliuria were observed in the majority of cases in both periods. Seasonal variation in serum potassium, erythrocyte potassium, urine volume and urinary excretion of sodium was observed. Values were significantly lower in the hot months. In the cool months, the urinary excretion of citrate correlated linearly with that of potassium (r = 0.696, p < 0.002). Such a correlation was not found in the hot months. We concluded that extracellular and intracellular potassium depletion might be present in these patients and is greater during the hot than during the cool months. The pathogenesis may be multi-factorial.