Relationship between deficiency of vitamin D and exponents of metabolic syndrome

OBJECTIVE

Widespread hypovitaminosis D and an increased incidence of metabolic syndrome (MetS) represent significant problems of contemporary medicine but link between them remain unresolved. We aimed to define relationship between vitamin D serum concentration and exponents of MetS.

PATIENTS AND METHODS

The studies were conducted on 70 individuals (51 with and 19 without MetS). Concentrations of 25(OH)D (25-hydroxyergocalciferol and 25-hydroxycholecalciferol), calcium, cholesterol, HDL, cholesterol LDL, triglycerides, fasting glucose, blood pressure and anthropometric parameters were measured.

RESULTS

Median concentration of vitamin D in the research population amounted to 41.46 nmol/L. Concentration of 25(OH)D in MetS group was lower than in remainder participants (38.45 nmol/L vs. 58.50 nmol/L, p = 0.0104). An inverse correlation was demonstrated between 25(OH)D level on one hand and body weight, waist and hips circumference, adipose body weight, Body Mass Index, Waist to Height Ratio (WHtR), glycaemia and number of MetS components on the other in persons free of MetS. No such relationships could be documented in MetS group. In the entire population values of Waist to Hip Ratio (WHpR) and WHtR indices manifested correlation with hyperglycaemia, hypertriglyceridaemia, low HDL concentrations.

CONCLUSIONS

In persons without MetS a relationship was detected between vitamin D concentration and exponents of metabolic syndrome, although further studies on this problem are required.

Plasma ghrelin and interleukin-6 levels correlate with body mass index and arterial blood pressure in males with essential hypertension

We examined an association between ghrelin, including its major isoforms, interleukin-6 (IL-6), body mass index (BMI), and mean arterial pressure (MAP) in male overweight patients with essential hypertension. Twenty hypertensive male patients with newly diagnosed essential hypertension (EH) before starting drug treatment and 22 age-matched healthy controls were enrolled in the study. Fasting total plasma ghrelin (TGhr), acyl ghrelin (AGhr), des-acyl ghrelin (DGhr) and IL-6 were determined and correlations between studied parameters were calculated. We found significantly lower total plasma ghrelin and higher plasma IL-6 in hypertensives when compared with the control. In patients with hypertension the negative correlations were found: between TGhr and BMI, DGhr and BMI, TGhr and MAP, and between DGhr and MAP. IL-6 positively correlated with BMI and MAP in hypertensive subjects. No correlations between all forms of ghrelin and IL-6 were noted. The changes in plasma ghrelin and IL-6 contribute independently to the elevated blood pressure in essential hypertension. Negative correlation of DGhr and MAP may suggest its hemodynamic involvement in regulation of blood pressure.

The influence of antihypertensive drugs on mineral status in hypertensive patients

OBJECTIVES

Long-term therapy of hypertension may influence mineral status in patients. However, drug-micronutrient interactions are largely unexplored in practice. This study intended to evaluate the effect of hypotensive monotherapy on iron, zinc, and copper levels, as well as on selected biochemical parameters, in newly diagnosed patients with hypertension, and to assess the influence of diet with optimal mineral levels on the mineral balance in these subjects.

PATIENTS AND METHODS

Forty-five patients, aged 18-65 years with diagnosed essential hypertension, beginning monotherapy treatment with diuretics, calcium antagonists, angiotensin-converting enzyme inhibitors, and β-blockers, were employed. Over three months, the patients underwent monotherapy (stage II). Next, patients were randomly divided into a diet group (of 27 subjects) and a control group (of 18 subjects). In this stage, which lasted one month, patients were given the same drug but also followed an optimal mineral-content diet (for the diet group), or else continued drug use without any change in diet (for control group) (stage III). Lipids, glucose, ceruloplasmin, and ferritin--along with superoxide dismutase and catalase activities--were assayed in serum. Iron, zinc, and copper concentrations in serum, erythrocytes, and urine were determined using flame atomic absorption spectrometry. Blood pressure was measured. Diet intake was monitored at each stage.

RESULTS

It was found that the zinc level in serum significantly decreased following treatment, and that the use of the optimal-mineral diet during antihypertensive treatment markedly increased zinc serum concentration. After treatment, a significant increase in zinc excretion in the urine was observed. Glucose levels in the serum of patients in stage II were significantly higher than in the baseline. In patients in the diet group, glucose levels markedly decreased. Moreover, a negative correlation was found between serum glucose and zinc levels in patients.

CONCLUSIONS

Antihypertensive treatments should include monitoring of mineral status. It seems that the zinc balance of patients on long-term therapy with hypotensive drugs may benefit from an optimal-mineral diet.

Evaluation of insulin resistance, tumor necrosis factor alpha, and total antioxidant status in obese patients smoking cigarettes

INTRODUCTION AND BACKGROUND

Obesity and smoking are leading causes of morbidity and mortality worldwide. Cross-sectional studies indicate that heavy smoking may be associated with a greater risk of obesity. While there are important unresolved issues in relation to the effect of smoking on body weight, there is increasing evidence that smoking is conducive to a greater accumulation of visceral fat and greater insulin resistance.

AIM

of this study was to determine the potential influences of obesity and smoking on tumor necrosis factor alpha (TNF-α), total antioxidant status (TAS), and insulin resistance.

SUBJECTS AND METHODS

30 obese nonsmokers, 30 obese smokers, 30 normal-weight smokers, and 30 healthy volunteers (the control) were studied. In all subjects, assessments of TNF-α, TAS, and insulin were made. Insulin resistance was evaluated according to the homeostasis model assessment-insulin resistance (HOMA-IR) protocol.

RESULTS

TNF-α concentrations, as well as insulin resistance levels, in obese patients significantly exceeded those observed in the control. Compared to the control, obese patients presented significantly lower TAS levels. In the group of obese patients who actively smoked cigarettes, further increases in TNF-α and insulin resistance, as well as decreases in TAS level, were noticed. TNF-α concentration and insulin resistance levels were significantly higher, while TAS was lower in normal-weight smoking subjects, compared to the control. A positive correlation between TNF-α and HOMA-IR was found in the overall population.

CONCLUSIONS

Obesity may evoke inflammatory processes, oxidative stress, and insulin resistance, all of which are aggravated by cigarette smoking. TNF-α should be considered in the complex pathogenesis of insulin resistance in obese patients who actively smoke.

Supplementation with L-arginine favorably influences plasminogen activator inhibitor type 1 concentration in obese patients. A randomized, double blind trial

BACKGROUND

Elevated plasminogen activator inhibitor type 1 (PAI 1) plays an important role in the pathogenesis of excess blood coagulability in obese patients. L-arginine supplementation has shown to be associated with enhanced cardiovascular and metabolic health. The aim of the study was to assess the effect of L-arginine supplementation on PAI 1 concentration and to evaluate the relation to changes in nitric oxide (NO) plasma level, insulin sensitivity (M value), and total antioxidant status (TAS) in obese patients.

MATERIAL/SUBJECTS AND METHODS

A randomized, double-blind, placebo-controlled study was conducted from March 2010 to June 2011. Eightyeight obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed, and PAI 1, NO, TAS levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique.

RESULTS

We found that 6-month L-arginine supplementation resulted in significant decrease of PAI 1. Significant increase of NO, TAS, and insulin sensitivity level were noticed. In a group of patients treated with L-arginine, negative correlation between a change of insulin sensitivity value and a change of PAI 1 concentration was found.

CONCLUSIONS

The present findings demonstrate favorable influence of L-arginine supplementation on PAI 1 concentration in obese patients. Beneficial influence is related to insulin sensitivity improvement. The potential therapeutic role of L-arginine administration in patients with obesity needs further investigation.

Oral L-arginine supplementation in patients with mild arterial hypertension and its effect on plasma level of asymmetric dimethylarginine, L-citruline, L-arginine and antioxidant status

BACKGROUND

Potential role of L-arginine supplementation as a new effective strategy of improving endothelial function in patients with hypertension is recently under consideration.

OBJECTIVE

To evaluate influence of 28-day oral supplementation of L-arginine on plasma level of asymmetric dimethylarginine (ADMA), L-citrulline, L-arginine and total antioxidant status (TAS), in patients with mild arterial hypertension.

SUBJECTS AND METHODS

54 participants (24 women and 30 men) were studied. Ambulatory blood pressure monitoring (ABPM) was used for allotting patients to either healthy control group (19 subjects) or hypertensive treatment group (35 patients). Patients were later randomized to either L-arginine (2 g tid or 4 g tid) or placebo. During 28 days of study on 5 consecutive visits TAS, plasma level of ADMA, L-citrulline, and L-arginine were measured.

RESULTS

In patients with mild hypertension treated with L-arginine significant increase in TAS and plasma level of arginine and citrulline was observed. Additionally plasma ADMA concentrations after 28 days of L-arginine supplementation significantly exceeded initial concentrations.

CONCLUSIONS

L-arginine supplementation increases plasma arginine, citrulline and TAS in patients with mild arterial hypertension. It confirms the thesis that augmented concentrations of L-arginine stimulate NO biosynthesis which leads to reduction of oxidative stress. Increase of ADMA plasma level after L-arginine supplementation confirms correlation between ADMA and L-arginine.

Serum resistin concentrations are higher in human obesity but independent from insulin resistance

Although obesity may be linked to resistin, the role of resistin in humans is still controversial. Conflicting results of the associations between resistin and BMI and measures of insulin resistance were reported. In view of the yet unexplained role of resistin in human obesity, the aim of this study was to examine correlations between serum resistin concentrations and the degree of human obesity and insulin sensitivity. For this purpose, we investigated 2 homogenous groups of obese and non obese humans, in whom the presence of obesity was the solely differentiating factor. The WHO definition of obesity was used. Study group consisted of 136 obese subjects (75 women and 61 men) and 48 non-obese controls (31 women, 17 men) aged 48.0 ± 10.1, and 48.8 ± 13.4 yrs, respectively.

RESULTS

Obese subjects showed higher resistin concentrations than non obese controls (24.89 ± 9.73 ng/mL, median 26.61 vs. 15.34 ± 4.68 ng/mL, median 14.76, P < 0.0001). Resistin concentrations correlated with BMI in the whole cohort (r = 0.4296, P < 0.0001), but not in obese and non-obese subjects separately (r = 0.1418, P = 0.0997; r = 0.2712, P = 0.0623, respectively). Moreover, serum resistin was not influenced by insulin resistance in either group examined.

CONCLUSION

Although concentrations of resistin differ between obese and non-obese humans, no relationship between resistin concentration and insulin resistance has been found. Correlations between resistin and BMI are present only in a mixed population but disappear in non obese and obese subjects when analyzed separately.

Leptin, soluble leptin receptors, free leptin index, and their relationship with insulin resistance and BMI: high normal BMI is the threshold for serum leptin increase in humans

Leptin binds to the soluble form of its receptor (sOB-R). Leptin and sOB-R balance (free leptin index, FLI) reflect leptin activity. Leptin correlates with obesity and insulin resistance, but it remains uncertain whether sOB-R and FLI also do the same. Therefore, the aim of this study was to measure serum leptin, sOB-R, and FLI, and evaluate their associations with BMI and insulin resistance. We studied 145 obese and 49 nonobese humans. Obesity was defined according to WHO (BMI >30 kg/m (2)). Results are given as: median and interquartile range, obese vs. nonobese, respectively. Leptin (ng/ml): 30.83, 37.27 vs. 8.31, 10.04; sOB-R (ng/ml): 17.62, 17.05 vs. 27.25, 11.30; FLI: 231.2, 310.0 vs. 30.85, 27.77; HOMA: 5.99, 6.64 vs. 3.92, 4.52; p<0.001 for all. Serum leptin, sOB-R, and FLI did not correlate with insulin resistance separately in obese and nonobese humans. Leptin and FLI, but not sOB-R, were associated with insulin resistance in obese and nonobese subjects examined together. Leptin, sOB-R and FLI differed between obese and nonobese humans, and, except sOB-R, correlated with BMI. In piecewise linear regression, BMI threshold where leptin increased was 24.6 (r=0.5969, p=0.00016 and <0.00001). Leptin and its free index, but not sOB-R, correlate with BMI only in a mixed obese and nonobese human cohort, and not in isolated obese or nonobese groups. Moreover, BMI threshold where leptin starts to increase is 24.6 kg/m (2), which is lower than the cutoff for overweight. Under the conditions, metabolic abnormalities may occur in parallel to much lower BMI levels as expected so far.

The Y111 H (T415C) polymorphism in exon 3 of the gene encoding adiponectin is uncommon in Polish obese patients

The genetic background of obesity is under research. Obesity-related phenotype candidate genes include the gene encoding adiponectin (AdipoQ). In this study, exon 3 of the adiponectin gene was screened for the Y111 H (Tyr111His, or T415C, rs17366743) polymorphism, and adiponectin serum concentrations were measured in 206 obese subjects (110 women and 96 men, aged 50.5+/-16.9 years). Their BMI, % of body fat, plasma glucose, insulin, and glycosylated hemoglobin were measured. Adiponectin was determined by enzyme-linked immunosorbent assay. Genomic DNA was extracted from peripheral blood leukocytes. A fragment of exon 3 of the adiponectin gene was amplified in PCR and screened for the Y111 H polymorphism in SSCP analysis. Genetic screening revealed a different SSCP pattern in 2 subjects. Subsequent genotyping disclosed the TC genotype in both subjects, resulting in Y111 H heterozygote variant frequency of 0.01 in the whole cohort. Other results for SNP (single nucleotide polymorphism) positive and negative subjects were as follows, respectively: BMI (kg/m (2)) 39.95+/-9.83 vs. 38.12+/-8.56; waist circumference (cm) 122+/-18.4 vs.115+/-16; glucose (mmol/l) 7.51+/-1.86 vs. 5.56+/-0.74; HbA1c (%) 7.55+/-1.86 vs. 6.58+/-1.36; body fat (%) 51+/-2 vs. 44+/-10; plasma insulin (mU/l) 28.92+/-16.50 vs. 37.59+/-47.34; adiponectin (ng/ml) 1301+/-15.8 vs. 5682+/-4156. Due to a proportion of 2 vs. 204, statistical calculations were not possible. The Y111 H adiponectin gene variant is uncommon in Polish obese subjects. Although we observed low adiponectin concentrations in Y111 H SNP heterozygote carriers, this finding was not confirmed by statistics.

Circulating serum adiponectin concentrations do not differ between obese and non-obese caucasians and are unrelated to insulin sensitivity

Reduced serum levels of adiponectin in obesity and insulin resistance seem paradoxical, since adipose tissue is the only source of adiponectin, and reports on that subject are contradictory. The aim of this study was to investigate the concentrations of adiponectin in non-obese and obese normoglycemic humans, and to determine the correlation between adiponectin and HOMA index of insulin sensitivity. Based on the WHO definition of obesity, 145 obese subjects and 49 non-obese controls (aged 20-55 years) were studied. The serum adiponectin concentrations did not differ between subjects and controls (p=0.6398) and were not correlated with HOMA index (r=-0.0211; p=0.8048, and r=-0.0523; p=0.4757, for subjects and controls, respectively). Adiponectin was not correlated with HOMA index in females (r=-0.0521; p=0.6546, and r=-0.0825; p=0.3981, for female subjects and controls, respectively) as well as in males (r=0.0033; p=0.9791, and r=0.0123; p=0.9131, for male subjects and controls, respectively). These results lead to the conclusion that neither the concentrations of adiponectin differ between obese and non-obese humans, nor does any relationship between adiponectin concentration and insulin sensitivity exist.

Effects of extracorporeal shock wave lithotripsy on renal function in patients with kidney stone disease

The effects of extracorporeal shock wave lithotripsy on glomerular and tubular renal functions were determined by serum beta2-microglobulin (Sbeta2m) and urinary beta2-microglobulin (Ubeta2m) estimations in patients with nephrolithiasis. Unilateral treatment was performed in all patients. Urinary and serum creatinine levels were determined according to the method of Yatzidis. Sbeta2m and Ubeta2m were measured by radioimmunoassay the day before ESWL, on the day of ESWL, and then 1, 2, 5, 7, 8, 9, 14, and 28 days after treatment. Creatinine clearance, hourly urinary beta2m excretion (Ubeta2m/h), and tubular reabsorption of beta2m (TRbeta2m) were calculated. After lithotripsy, significant increases in Ubeta2m, Ubeta2m/h, and TRbeta2m were found (p < 0.001), whereas Sbeta2m, serum creatinine, and creatinine clearance values remained unchanged. Ubeta2m, Ubeta2m/h, and TRbeta2m reached their pretreatment values within 7-9 days after ESWL. We concluded that ESWL does not affect the glomerular filtration rate; however, it leads to a transient proximal tubular dysfunction.

[Digoxin as a cause of chromatopsia and depression in a patient with heart failure and hyperthyroidism]

67 year old patient with chronic heart failure and persistent atrial fibrillation had overdosed glycosides for several months. The symptoms of gastrointestinal system and nervous system appeared after long term therapy with toxic doses of glycosides. Originally depression was diagnosed based on the central nervous system disturbances. Even though overdose of glycosides was diagnosed the blood serum glycoside level was within the therapeutic limits. Based on the precise analysis of the data, it was concluded that the reason for normal blood serum glycoside level in this case was coexisting hyperthyreosis.

[The role of rheological factors in the pathogenesis of diabetic nephropathy]

In this paper the stages and pathogenesis of diabetic nephropathy have been presented. Factors which influence blood rheology and hemorheologic abnormalities founded in diabetic patients have been reviewed. Attention was paid to the role of rheological parameters in initiating and progression of diabetic nephropathy. The possibilities of prevention of diabetic microvascular complications by influencing blood rheology have been presented.

[Leptin and obesity]

Obesity is associated with increased incidence of cardiovascular diseases, insulin resistance, dyslipoproteinemia and cancer. The discovery of leptin in 1994 has provided a lot of new information about obesity. Leptin is a 167-amino acid peptide synthetized almost exclusively in adipose tissue. This hormone circulates in blood serum in both free and bound forms. The long isoform of leptin receptor is widely distributed in brain, whereas numerous short forms are also being present in peripheral tissues. Leptin acts by binding to the receptors in hypothalamus and altering a release of several neuropeptides, especially neuropeptide Y, regulating energy intake and expenditure. Apart from signaling energy reserves to the brain, leptin promotes hematopoiesis, influences pubertal development and contributes to the increase in arterial blood pressure. Leptin production regulation in humans is poorly understood, but appears to depend on the total body fat, changes in energy intake and serum level of several hormones. Despite the recent advances in the knowledge of both physiology and pathophysiology of leptin, several many important questions require further studies.

[Endothelin and arterial hypertension]

Endothelins (ETs) are peptides of 21 amino acids synthesized and released by variety of cells. Endothelin (now this peptide is called endothelin-1 (ET-1)) was isolated and identified in 1988 by Yanagisawa et al. Following studies revealed two other isoforms of endothelin': Endothelin-2 (ET-2) and endothelin-3 (ET-3). All of them bind to two types of receptors (A and B (ET-A r, ET-Br). ET-A r are responsible for concentration mediating. Two subtypes of ET-B r are known. ET-B1 r mediates vasorelaxation; ET-B2 vasoconstriction. ETs (especially ET-1) have variety of biological actions but the most important are vasoconstrictor and mitogenic action. Through these two mechanism ETs may participate in the pathogenesis and/or in the maintenance of hypertension in both experimental animal models and human essential hypertension. The intravenous infusion of synthetic ET induces a long-lasting elevation of blood pressure in experimental animals and in healthy humans. Number of studies have shown enhanced responses to ET in hypertensive subjects but decreased responses have also been reported. Similarly, plasma levels of ET-1 are either normal or elevated in experimental and human essential hypertension. Numerous investigators have suggested an interaction between ET and angiotensin-converting enzyme inhibitors through the renin-angiotensin system or through the accumulation of endogenous bradykinin. Also calcium antagonists of different classes prevent endothelin-induced contractions. Endothelin- converting enzyme inhibitor (phosphoramidon) and ET-A/B r antagonists (bosentan, BQ-123, FR139317) may have potential role as vasodilators in the treatment of hypertension.

Acetylsalicylic acid (aspirin) test for the diagnosis of renovascular hypertension

OBJECTIVE

To determine whether the administration of acetylsalicylic acid (ASA, also known as Aspirin) differentiates patients with renovascular hypertension from those with essential hypertension, in order to provide a simple alternative to more expensive forms of diagnosis for this condition.

DESIGN

Trial of ASA test in patients with previously diagnosed essential and renovascular hypertension.

SETTING

Inpatient department of an academic health sciences centre in Poznan, Poland.

PATIENTS

Forty patients with essential hypertension and 21 patients with renovascular hypertension.

INTERVENTIONS

Patients were given an intravenous injection of ASA (10 mg/kg body weight), blood pressure was measured and blood was sampled and assayed for plasma renin activity (PRA) before and 30 minutes after the injection.

RESULTS

ASA infusion in patients with renovascular hypertension resulted in a decrease in PRA from 15.2 (standard deviation [SD] 12.4) ng/mL per hour to 7.2 (SD 9.8) ng/mL per hour, whereas in patients with essential hypertension the initial PRA was significantly lower before ASA administration and did not change afterward. In patients with renovascular hypertension, the mean systolic, diastolic and arterial pressure decreased significantly (p < 0.001) after ASA infusion, but these did not change in patients with essential hypertension. Based on the criterion of 4 mm Hg as a detectable decrease in mean blood pressure, the sensitivity of the ASA test was 95.0% and the specificity 82.5%; its positive predictive value was 74% and its negative predictive value 97%.

CONCLUSION

The precise measurement of blood pressure during the ASA test may provide a useful method of differentiating between patients with renovascular and essential hypertension.

[Effect of nifedipine on proximal tubular function in patients with essential hypertension]

The effect of a single 20 mg sublingual dose of nifedipine on function of proximal tubule of nephron in patients with essential hypertension was studied by measuring changes in renal excretion of water, sodium, uric acid and beta-2-microglobulin (B2m) after nifedipine administration. Fifteen patients at the mean age of 40.1 +/- 7 years, with mild to moderate essential hypertension were studied. Systolic (SBP) and diastolic (DBP) blood pressure as well as heart rate (HR) were recorded every hour. Urine was sampled over 60-min, four times. The first two periods were regarded controls and the last two periods followed the administration of a 20 mg sublingual nifedipine dose. Blood samples were taken 1 h before and 1 h after that. Sodium, uric acid, B2m and creatinine in urine and plasma were determined. Nifedipine caused a significant fall in SBP and DBP (p < 0.001) and a marked increase in HR (p < 0.001). Diuresis, sodium (CNa) and uric acid (Cua) clearances were significantly increased (p < 0.001). Similarly, fractional excretion of sodium (FENa) was higher (p < 0.01). B2m excretion (UB2m) showed a two fold increase after nifedipine administration (p < 0.01). A positive correlations were found between the changes in CNa and Cua (r = 0.835, p < 0.001) and between the changes in UB2m and CNa (r = 0.747, p < 0.001). The results indicate that nifedipine induces an increase in diuresis, natriuresis and excretion of uric acid and B2m. These findings and the relationship between the changes in UB2m and Cua proves effect of nifedipine on proximal tubular function.

[Evaluation of uric acid transport in nephrons of patients with calcium nephrolithiasis and hyperuricosuria]

Renal excretion of uric acid was studied in 48 patients with recurrent calcium nephrolithiasis. Hyperuricosuria was found in 16 patients (33%) and among them 10 patients had increased values of urate clearance and fractional excretion. The tubular transport of urate was evaluated by means of pharmacological tests with pyrazinamide (PZA) and benzbromarone (BB) in these 11 patients with hyperuricosuria of renal origin. PZA suppression test was normal in 10 patients while in one case uric acid excretion was not suppressed sufficiently by PZA. Maximal uricorusirc response to BB was increased in two patients, normal in one patient and impaired in eight patients. PZA and BB tests revealed isolated defect of uric acid postsecretory reabsorption in seven patients, impaired reabsorption at both pre- and postsecretory site in one case and enhanced tubular secretion of uric acid in two patients. This study indicates that different defects of uric acid transport in nephron are the frequent cause of hyperuricosuria in patients with recurrent calcium nephrolithiasis.

[Usefulness of determining beta-2-microglobulin in serum and urine in patients with metabolically active kidney calculi and healthy individuals]

The study aimed at evaluating the proximal tubule function in patients with active metabolic urolithiasis with the assay of beta 2-microglobulin in the urine. The studies involved 30 patients with urolithiasis associated with chronic pyelonephritis and 31 patients with urolithiasis without pyelonephritis. Fifty healthy individuals served as a control group. Serum and urine beta 2-microglobulin concentrations were assayed with radioimmunological technique in all persons. Clearance of this microglobulin and tubular reabsorption were calculated. It was found that beta 2-microglobulin excretion with the urine is significantly higher in patients with metabolically active urolithiasis accompanied by the chronic pyelonephritis. beta 2-microglobulin clearance was significantly higher and tubular reabsorption significantly lower than those in patients without pyelonephritis and in control group. These finding suggest a dysfunction of the proximal tubule in patients with urolithiasis produced by the chronic inflammatory process in the urinary system. Negative correlation between blood serum beta 2-microglobulin levels and creatinine clearance was shown. Therefore, serum beta 2-microglobulin concentrations may be of value in evaluation of the glomerular filtration rate.

[Evaluation of selected indicators of the renal proximal tubule function in patients treated with gentamicin]

The study aimed at evaluating proximal renal tubule function in patients with nephrolithiasis and chronic pyelonephritis, and in patients with infectious diseases treated with gentamicin. The study involved 2 groups of patients: group A--17 patients with nephrolithiasis and chronic pyelonephritis and group B--30 patients with other infectious diseases (pneumonia, biliary tract infections) but with normal glomerular filtration rate. Patients from both groups were treated with gentamicin in a daily dose of 2-3 mg/kg for 7-10 days. Serum and urine creatinine levels were assayed in all patients prior to, 2-3, 7, 10 days, and after the treatment. Patients assigned to group B were divided into two subgroups: B1 included 15 patients with normal beta 2-microglobulinuria, and B2 15 patients with increased renal loss of beta 2-microglobulin and decreased tubular reabsorption of this protein. Significant increase in beta 2-microglobulinuria was seen on the third day of therapy, the decrease in the tubular reabsorption and glomerular filtration rate were noted in all patients on the seventh day of gentamicin administration. Beta 2-microglobulinuria was significantly higher in patients from groups A and B2 in comparison with group B1 in which no dysfunction of the proximal renal tubule was present before gentamicin therapy. A degree of beta 2-microglobulinuria is an early and sensitive indicator of gentamicin nephrotoxicity. The risk of nephrotixic symptoms is particularly obvious in patients with deteriorated function of renal proximal tubuli before the treatment with gentamicin.

[Nephrotoxic effect of gentamicin on the function of the proximal tubules of the nephron and glomerular filtration]

The purpose of the study was assessment of gentamicin nephrotoxicity with reference to proximal tubule function and glomerular filtration. The study was carried out in 20 patients with nephrolithiasis and chronic pyelonephritis, and 33 patients with respiratory and bile tract infections treated with gentamicin in doses of 2-3 mg/kg/2 h. In 3 patients with nephrolithiasis and chronic pyelonephritis signs of increased nephrotoxicity of gentamicin (according to Schentag criteria) were found. Similar signs were demonstrated in 3 patients with non-urinary tract infections. The abnormalities included increased excretion of low-molecular protein and beta-2-microglobulin (B2m), reduction of B2m reabsorption and lower glomerular filtration. Beta-2-microglobulinuria increase precede by 4-5 days the fall of the glomerular filtration rate which suggests that beta-2-microglobulinuria assessment is an early sign of gentamicin neurotoxicity.

[Malignant mesothelioma of the pericardium--diagnostic problems]

A case of the malignant mesothelioma of pericardium is presented as this is rare primary neoplasm of pericardium. Diagnosis of the malignant mesothelioma of pericardium is a difficult clinical problem. The authors discuss the value of various diagnostic techniques used in diagnosis of the malignant mesothelioma of pericardium.

[Effect of nifedipine on kidney output of calcium, oxalic acid, and saturation of urinary calcium oxalate]

The study involved 30 patients treated with nifedipine in daily dose of 30 mg for 7 days. Calcium, magnesium, phosphate, oxalate, and uric acid levels in the urine were measured. It was found that nifedipine significantly decreased oxaluria urinary excretion of calcium, magnesium, phosphate, and uric acid remained unchanged following nifedipine therapy. Results may suggest that nifedipine may exert an influence on renal stone formation.

[Effect of intravenous administration of cimetidine on renal excretion of calcium, phosphates, magnesium and adenosine cyclic monophosphate]

An effect of cimetidine on parathyroid glands functioning in healthy subjects was evaluated. Serum calcium, phosphate, and magnesium concentrations together with renal excretion++ of these ions in healthy subjects as well as cAMP excretion++ in selected individuals were determined before and following intravenous administration of cimetidine (Altratmet Lek Ljublijana) in total dose of 500 mg (50 mg injected rapidly as a bolus following with 450 mg in an intravenous infusion during 60 minutes). No significant changes in serum calcium, phosphates, and magnesium concentrations were noted. Renal clearance of calcium and magnesium remained unchanged whereas renal phosphate excretion++ increased from 10.69 +/- 4.9 mL/min to 15.1 +/- 5.41 mL/min (p less than 0.02). Excretion++ of 3.5 cAMP increased from 2.65 +/- 2.19 nM/min to 5.16 +/- 2.0 nM/min (p less than 05). The obtained results do not exclude stimulating effect of intravenous cimetidine on parathyroid glands. Cimetidine given intravenously in the bleeding gastric or duodenal ulcers in the course of the primary hyperparathyroidism+ may decrease serum phosphate levels due to increased exretion of this ion with the urine.