Pote Sriboonlue

Incidence of urolithiasis in northeast Thailand.

Background:

Blood and urinary aggregator and inhibitor composition in controls and renal-stone patients from northeastern Thailand.

Renal-stone disease (RSD) is common in the rural communities of northeastern Thailand. We report the biochemical composition of blood and urine in 25 healthy city dwellers (G1), 12 healthy village dwellers (G2) and 25 village dwellers who had RSD (G3). They were male with a range of ages between 20 and 50 years and were free of renal failure, urinary infection, urinary obstruction and systemic illness. The results showed that hypocitraturia, hypokalemia and hypokaliuria were more common in the latter 2 groups. The 24-h urinary citrate excretion correlated significantly with urinary potassium in G3 cases (r = 0.704, p = 0.0002). After potassium chloride supplementation, serum and urinary potassium increased remarkably (p less than 0.003 and p = 0.002, respectively), whereas urinary citrate remained unchanged. Our results suggest that the predominant abnormality in our RSD patients were hypocitraturia and potassium deficiency and that these may be related.

Uricosuric effect of Roselle (Hibiscus sabdariffa) in normal and renal-stone former subjects.

AIM OF THE STUDY The Roselle (Hibiscus sabdariffa) was investigated for its uricosuric effect. MATERIALS AND METHODS A human model with nine subjects with no history of renal stones (non-renal stone, NS) and nine with a history of renal stones (RS) was used in this study. A cup of tea made from 1.5 g of dry Roselle calyces was provided to subjects twice daily (morning and evening) for 15 days. A clotted blood and two consecutive 24-h urine samples were collected from each subject three times: (1) at baseline (control); (2) on days 14 and 15 during the tea drinking period; and (3) 15 days after the tea drinking was stopped (washout). Serum and 24-h urinary samples were analyzed for uric acid and other chemical compositions related to urinary stone risk factors. RESULTS All analyzed serum parameters were within normal ranges and similar; between the two groups of subjects and among the three periods. Vis-à-vis the urinary parameters, most of the baseline values for both groups were similar. After taking the tea, the trend was an increase in oxalate and citrate in both groups and uric acid excretion and clearance in the NS group. In the RS group, both uric acid excretion and clearance were significantly increased (p<0.01). When the fractional excretion of uric acid (FEUa) was calculated, the values were clearly increased in both the NS and SF groups after the intake of tea and returned to baseline values in the washout period. These changes were more clearly observed when the data for each subject was presented individually. CONCLUSIONS Our data demonstrate a uricosuric effect of Roselle calyces. Since the various chemical constituents in Roselle calyces have been identified, the one(s) exerting this uricosuric effect need to be identified.

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.

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.

An indirect method for urinary oxalate estimation

Oxalate was first coprecipitated at pH 5 as calcium oxalate precipitate (COP) with excess calcium ions and ethanol. Interference in the COP, mainly calcium phosphate, was successfully removed by washing with 0.1 M acetic acid equilibrated with calcium oxalate monohydrate crystal. Since the calcium content of the washed COP showed a high correlation with the original oxalate concentration, both in artificial (r = 0.998, P <0.001) and real (r = 0.951, P < 0.001 for colorimetric; r = 0.982, p < 0.001 for enzymatic methods) urines, it could be used to predict indirectly the urinary oxalate concentration. The mean percentage recovery of the predicted oxalate was 98.95, S.D. = +/-4.77% (n = 6). The method is simple, reproducible and relatively precise. It therefore could be set up as a routine method of urinary oxalate assessment in general clinical laboratories.

Effects of Orthosiphon grandiflorus, Hibiscus sabdariffa and Phyllanthus amarus Extracts on Risk Factors for Urinary Calcium Oxalate Stones in Rats

PURPOSE We evaluated the antilithic effect of Orthosiphon grandiflorus, Hibiscus sabdariffa and Phyllanthus amarus extracts on known risk factors for calcium oxalate stones in rats. MATERIALS AND METHODS We divided 30 male Wistar rats into 5 equal groups. Controls were fed a standard diet and the remaining groups received a 3% glycolate diet for 4 weeks to induce hyperoxaluria. One glycolate fed group served as the untreated group and the others were given oral extracts of Orthosiphon grandiflorus, Hibiscus sabdariffa or Phyllanthus amarus at a dose of 3.5 mg daily. We collected 24-hour urine and blood samples. Kidneys were harvested for histological examination. We measured the renal tissue content of calcium and oxalate. RESULTS The Hibiscus sabdariffa group showed significantly decreased serum oxalate and glycolate, and higher oxalate urinary excretion. The Phyllanthus amarus group showed significantly increased urinary citrate vs the untreated group. Histological examination revealed less CaOx crystal deposition in the kidneys of Hibiscus sabdariffa and Phyllanthus amarus treated rats than in untreated rats. Those rats also had significantly lower renal tissue calcium content than untreated rats. All parameters in the Orthosiphon grandiflorus treated group were comparable to those in the untreated group. CONCLUSIONS Hibiscus sabdariffa and Phyllanthus amarus decreased calcium crystal deposition in the kidneys. The antilithic effect of Hibiscus sabdariffa may be related to decreased oxalate retention in the kidney and more excretion into urine while that of Phyllanthus amarus may depend on increased urinary citrate. In contrast, administering Orthosiphon grandiflorus had no antilithic effect.

Serial analyses of postmortem changes in human skeletal muscle : A case study of alterations in proteome profile, histology, electrolyte contents, water composition, and enzyme activity

Postmortem tissues are frequently used in forensic investigation, clinical studies, and biomedical research. It is well known that the shorter period from death to analyses provides the more accurate results. However, the longest postmortem interval that still provides the reliable data remains unclear. We performed serial analyses of postmortem changes in proteome profile, histology, electrolyte contents, water composition, and enzyme activity in human vastus lateralis muscle from a male cadaver (died from a motorcycle accident). This uninjured muscle was sectioned into several 1‐cm3 cubes and stored in individual closed tubes at 4 or 25°C for 0, 2, 4, 6, 12, 24 or 48 h prior to proteomic, histological, chemical and biochemical analyses. At 4°C, the 2‐DE proteome profile remained unchanged until 24 h, when some poorly focused protein spots and significant decrease in the total number of visualized spots were observed. These changes were detectable earlier (12 h) in the samples stored at 25°C. Profound vacuolization and autolysis started at 24 and 6 h for the samples stored at 4ºC and 25°C, respectively. K and Mg contents began to increase at 12 and 48 h, respectively, for both temperatures. However, the increase in Na and Ca contents began at 24 h in the samples stored at 4°C, but started earlier (12 h) in those stored at 25°C. Water content started to decline at 48 and 24 h in the samples stored at 4 and 25°C, respectively. Muscle lactate dehydrogenase activity began to be out of range at 12 h for both temperatures. These findings demonstrate that storing the samples at 4°C could delay some of the aforementioned changes, which occurred more rapidly at 25°C. Our results also suggest that muscle proteome profile, histology, electrolyte contents, water composition, and enzyme activity should be analyzed within the optimal postmortem intervals, which vary among individual analyses, to obtain the most reliable data.

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.

Metabolic enzymes, antioxidants, and cytoskeletal proteins are significantly altered in vastus lateralis muscle of K-depleted cadaveric subjects.

Molecular mechanisms underlying myopathy caused by prolonged potassium (K) depletion remain poorly understood. In the present study, we examined proteome profile of vastus lateralis muscle obtained from cadaveric subjects who had K depletion (KD) (muscle K<80 micromol/g wet weight) compared to those who had no KD (NKD) (muscle K>or=80 micromol/g wet weight) (n=6 per group). Muscle proteins were extracted, resolved by 2-DE, and visualized with CBB-R250 stain. Spot matching and intensity analysis revealed significant changes in levels of 11 (6 increased and 5 decreased) protein spots in the KD group. Q-TOF MS and MS/MS analyses identified these altered proteins as metabolic enzymes (aldehyde dehydrogenase 1A1, uridine diphosphoglucose pyrophosphorylase, enolase 1, cytosolic malate dehydrogenase, and carbonic anhydrase III), antioxidants (peroxiredoxin-3 isoform b), cytoskeletal proteins (slow-twitch skeletal troponin I and myosin light chain 2), and others. These altered proteins are involved in many cellular functions, including bioenergetics, acid-base regulation, oxidative stress response, and muscle contractility. Validation was done by Western blot analysis, which confirmed the increased level of peroxiredoxin-3 and decreased level of troponin-I in the KD muscle. Linear regression analysis also revealed a significant negative correlation between peroxiredoxin-3 level and muscle K content (r=-0.887; p<0.001), as well as a significant positive correlation between troponin-I level and muscle K content (r=0.618; p<0.05). Our results implicate the important roles these altered proteins play in the development of KD-associated myopathy.