Association of Serum Omentin-1 Concentration with the Content of Adipose Tissue and Glucose Tolerance in Subjects with Central Obesity.

Omentin is one of the few adipokines with potentially beneficial metabolic effects. The main aim of this study was to determine the association between serum omentin-1 levels and the occurrence of central obesity and abnormal glucose tolerance, taking into account gender. The study involved 88 participants aged 30-60, including 47 women and 41 men. Two subgroups among the obese subjects were distinguished-those with normal and abnormal glucose tolerance. Anthropometric and biochemical examinations and blood pressure measurements were performed. Omentin-1 concentrations were significantly lower among patients with obesity compared to those without obesity (p = 0.027) and, similarly, comparing men with abnormal glucose tolerance with men with normal glucose tolerance (p = 0.035). In contrast, no such pattern was observed in women. The multivariable regression model showed a significant effect of gender status and important factors of tissue insulin sensitivity, such as OGGT results, WHR and amount of body fat, on the variability of serum omentin-1 concentration in the entire study population (R2adj. = 13.7%; p = 0.003). High omentin-1 levels found in men with obesity and normal glucose tolerance suggest that omentin-1 protects against metabolic disorders associated with obesity in the male population.

The Association of Serum Circulating Neuropeptide Q and Chemerin Levels with Cardiometabolic Risk Factors among Patients with Metabolic Syndrome.

The potential involvement of neuropeptide Q (NPQ) and chemerin (CHEM) in metabolic disorders is yet to be fully elucidated. The aim of this study was to evaluate serum concentrations of NPQ and CHEM and to establish their relationship with cardiometabolic risk factors among individuals with metabolic syndrome. A total of 66 patients with metabolic syndrome (MetS) and 83 healthy volunteers (non-MetS) underwent biochemical, blood pressure, and anthropometric measurements. The concentration of NPQ in the MetS group was significantly lower (0.47 (0.34 ; 0.54) vs. 0.52 (0.43 ; 0.60) ng/mL, p = 0.015) than in non-MetS, while there were no differences in CHEM level. In the entire study population, we observed several negative correlations between NPQ concentration and waist-hip ratio (WHR), visceral adipose tissue, diastolic blood pressure (DBP), triglycerides (TG) along with a positive correlation with high-density lipoprotein (HDL), total muscle mass, and CHEM. Moreover, a negative correlation was observed in the MetS group between NPQ and glycemia. CHEM showed no significant correlations with cardiometabolic risk factors in the study population. In a multiple regression model, the total muscle mass proved to be an independent factor determining NPQ concentration in the population (p < 0.00000001, R2adj = 28.6%). NPQ seems to protect against metabolic disorders correlated with obesity. Thus, it is worth considering NPQ level as a candidate protective biomarker of metabolic syndrome complications.

Assessment of Selected Clock Proteins (CLOCK and CRY1) and Their Relationship with Biochemical, Anthropometric, and Lifestyle Parameters in Hypertensive Patients.

BACKGROUND: Circadian rhythms misalignment is associated with hypertension. The aim of the study was to evaluate the concentration of selected clock proteins-cryptochrome 1 (CRY1) and circadian locomotor output cycles kaput (CLOCK) to determine their relationships with biochemical and anthropometric parameters and lifestyle elements (diet, physical activity, and quality of sleep) in hypertensive patients. METHODS: In 31 females with hypertension (HT) and 55 non-hypertensive women (NHT) the CRY1 and CLOCK concentrations, total antioxidant status (TAS), lipid profile, and glycemia were analyzed. Blood pressure and anthropometric measurements, nutritional, exercise, and sleep analyses were performed. RESULTS: In the HT group, the CRY1 level was 37.38% lower than in the NHT group. No differences were noted in CLOCK concentration between groups. BMI, FBG, and TG were higher in the HT group compared to the NHT group, while TC, LDL, and HDL levels were similar. The study showed no relationship between CRY1 or CLOCK concentrations and glucose or lipids profile, amount of physical activity, or sleep quality, although CRY1 was associated with some anthropometric indicators. In the HT group, increased CLOCK and CRY1 values were associated with a high TAS level. CONCLUSIONS: The serum level of CRY1 could be considered in a detailed diagnostic of hypertension risk in populations with abnormal anthropometric indices.

Vaspin (but not neuropeptide B or neuropeptide W) as a possible predictor of body weight normalization in anorexia nervosa.

INTRODUCTION: The aim of the study was to evaluate the correlation between the nutritional status of patients with anorexia nervosa (AN) and levels of vaspin (VASP), neuropeptide B (NPB), neuropeptide W (NPW) and total antioxidant status (TAS). MATERIAL AND METHODS: Ninety serum samples collected from 30 teenage female patients during the acute stage of AN and 30 healthy persons (CONTR) were subjected to biochemical analysis; patients with AN were examined at the beginning of the study (AN-I) and after hospitalization (AN-II), as a result of which partial stabilization of anthropometric measurements was achieved (an increase of body mass index (BMI) by 3.5 kg/m2). RESULTS: Vaspin levels dropped at the end of the hospitalization (compared to AN-I, p < 0.05), achieving values comparable to the CONTR; moreover there was a positive correlation between VASP level and the achieved body weight in AN-II (p < 0.05). Positive correlations were also noted with regard to VASP vs. NPB in AN-I (p < 0.02) (and AN-II, p < 0.013), as well as in the case of VASP vs. NPW in the same groups (p < 0.02 and p < 0.015, respectively). NPB concentration was higher in AN-I (p < 0.05) and AN-II (p < 0.018) than in CONTR, whereas there were no differences (p > 0.05) with regard to levels of VASP, NPW, or TAS. CONCLUSIONS: The high level of NPB despite treatment and normalization of VASP level may suggest that there are chronic neuroendocrine disorders at play in anorexia nervosa.

Evaluation of Vitamin D Fractions in Obese Hypertensive Patients.

Vitamin D fractions can be involved in the pathogenesis of metabolic disorders, but their concentrations are rarely determined. The aim of this study was to evaluate the concentration of vitamin D fractions in obese hypertensive patients and to determine its associations with anthropometric parameters, glucose levels, and lipid profiles. A total of 85 obese hypertensive patients (OBHT) and 40 nonobese nonhypertensive subjects (NOBNHT) underwent biochemical measurements of lipid profiles, glycemia, 25-hydroxyvitamin D (25(OH)D), free vitamin D (free25(OH)D), vitamin D binding protein, albumin levels. Moreover, free25(OH)D and bioavailable25(OH)D (bio25(OH)D) concentrations were calculated. Blood pressure and anthropometric measurements were performed. Differences between groups (p < 0.001) were found for 25(OH)D (OBHT 40.25 ± 18.02 vs. NOBNHT 64.10 ± 22.29 nmol/L), free25(OH)D (9.77 (7.46; 11.49) vs. 13.80 (10.34; 16.82) pmol/L), bioavailable 25(OH)D (3.7 (2.8; 4.4) vs. 5.4 (4.2; 6.7) nmol/L), and calculated free25(OH)D (7.82 (5.54; 11.64) vs. 10.46(8.06;16.28) pmol/L, p = 0.002). The OBHT patients showed no relationship between vitamin D fractions concentration and glucose or lipids level, although it was associated with anthropometric parameters. In the NOBNHT group, vitamin D fractions correlated positively with HDL cholesterol and negatively with triglyceridemia and hip circumference. Vitamin D fractions were decreased in obese hypertensive subjects, and were associated with anthropometric parameters, but not with glucose level or lipid profiles; they thus cannot be considered as a predictive marker of metabolic disorders in this group of patients.

Neuropeptide B and neuropeptide W as new serum predictors of nutritional status and of clinical outcomes in pediatric patients with type 1 diabetes mellitus treated with the use of pens or insulin pumps.

INTRODUCTION: The aim of our study was to determine the relationship between neuropeptide B (NPB), neuropeptide W (NPW), nutritional and antioxidant status and selected fat- and bone-derived factors in type 1 diabetes mellitus (T1DM) treated using pens (T1DM pen group) or insulin pumps (T1DM pump group) in order to investigate the potential role of NPB and NPW in the clinical outcomes of T1DM. MATERIAL AND METHODS: Fifty-eight patients with T1DM and twenty-five healthy controls (CONTR) participated in the study. Assessments of NPB, NPW, total antioxidant status (TAS), leptin, adiponectin, osteocalcin, and free soluble receptor activator for nuclear factor κB (free sRANKL) were conducted. RESULTS: NPB, NPW, leptin, and TAS were lower (by 33%, p < 0.013; 34%, p < 0.008; 290%, p < 0.00004; 21%, p < 0.05; respectively), while adiponectin was by 51% higher (p < 0.006) in T1DM vs. CONTR, while osteocalcin and free sRANKL levels were similar in both groups. NPW was lower in the T1DM pen group both vs. the T1DM pump group (36% lower, p < 0.0009) and vs. the CONTR group (35% lower, p < 0.002). In the T1DM pen group, but not in the T1DM pump group or the CONTR group, the Cole index and TAS levels explain (besides NPB) the variation in NPW values. ROC curves showed that serum levels of leptin, adiponectin, NPB and NPW (but not osteocalcin or free sRANKL) were predictive indicators for T1DM. CONCLUSIONS: Measurements of NPB and NPW, besides leptin and adiponectin, are worth considering in the detailed prognosis of nutritional status in T1DM, primarily in the T1DM pen-treated population.

Chemerin, Resistin, and Adiponectin in Patients with Connective Tissue Diseases.

BACKGROUND: The exact role of cytokines in inflammation and metabolic disorders in case of connective tissue diseases (CTDs) is under discussion. METHODS: In this study, we intended to find the relationship between the selected cytokines in inflammatory and metabolic disorders in patients with CTDs (n=55) and compared the results with those of control group subjects (n=25) matched by age and body mass. We estimated their nutritional status by the bioimpedance method. The levels of basic biochemical parameters and the levels of adiponectin, resistin, and chemerin were also estimated. Multiple regressions and area under the curve in receiver operating characteristic (AUC-ROC) curve were used to find the associations of aforementioned parameters. RESULTS: Patients with CTDs exhibited higher levels of chemerin than that of control group subjects. We found an inverse relationship between chemerin, RBC count, and hemoglobin levels. The concentration of adiponectin inversely correlated with the levels of platelets and concentrations of glucose and triglycerides as well as the erythrocyte sedimentation rate, whereas the concentration of resistin was positively correlated with WBC count, C-reactive protein (CRP), and the amount of used oral glucocorticosteroids. The mean ± standard deviation for the AUC-ROC curve in case of chemerin was the highest (AUC-ROC=0.714, p=0.0005) than that of both resistin and adiponectin. CONCLUSIONS: Chemerin and resistin levels are related to the inflammatory state in patients with CTDs, whereas adiponectin levels seem to be correlated with a protective effect. Chemerin can be considered as a marker differentiating a proinflammatory state present in CTDs.

Neuropeptide B and Vaspin as New Biomarkers in Anorexia Nervosa.

INTRODUCTION: The aim of the study was to assess the correlation between the levels of neuropeptide B (NPB), neuropeptide W (NPW), vaspin (VAS), and the total antioxidant status (TAS) in the blood, as well as nutritional status of patients with anorexia nervosa (AN). MATERIALS AND METHODS: The study covered a cohort of 76 female teenagers, including 46 females with extreme AN and 30 healthy peers (CONTR) aged 12-17. RESULTS: AN persons were characterized by higher (in comparison to CONTR) NPB and VAS concentrations and lower values of TAS levels, body weight, and anthropometric values. Positive correlations between NPB and VAS levels were noted in the AN group (R=0.33; p<0.001) as well as between concentrations of NPW and VAS in the same group (R=0.49; p<0.001). Furthermore, positive correlations existed between NPB and NPW concentrations across the whole studied population (AN+CONTR; R=0.75; p<0.000001), AN (R=0.73; p<0.000001) and CONTR (R=0.90; p<0.0005). CONCLUSIONS: In detailed diagnostics of AN it is worth considering testing NPB and VAS levels.

Impact of 25-hydroxyvitamin D, free and bioavailable fractions of vitamin D, and vitamin D binding protein levels on metabolic syndrome components.

INTRODUCTION: Various forms of vitamin D and factors involved in their metabolism can play a role in the etiopathogenesis of metabolic disorders. This paper aims to define the relationship between concentration of the hydroxylated form of vitamin D (25(OH)D), the fraction of free and bioavailable vitamin D, and of vitamin D binding protein (VDBP) levels on the one hand and the prevalence of metabolic syndrome components on the other. MATERIAL AND METHODS: The studies were conducted on 79 people, including 52 with metabolic syndrome (MetS+) and 27 without it (MetS-). Biochemical measurements (lipid profile, glycemia, 25(OH)D, VDBP, albumin, calcium, parathyroid hormone) were performed, concentration of free and bioavailable vitamin D was mathematically calculated, and anthropometric and blood pressure measurements were taken. RESULTS: The mean ± SD concentration of 25(OH)D among MetS+ individuals (41.90 ±13.12 nmol/l) was lower (p < 0.0001) than among the MetS- group (66.09 ±18.02 nmol/l). Differences between groups were observed in relation to medians/means of concentrations of free and bioavailable vitamin D (p < 0.0001) but not in the case of VDBP. In the entire study population, 25(OH)D correlated with all metabolic syndrome components, whereas its free and bioavailable fraction correlated with particular components of the syndrome. In the MetS+ group, VDBP concentration negatively correlated with body mass index (p = 0.037) and levels of diastolic pressure (p = 0.022). In the case of the MetS- group, the free fraction of vitamin D negatively correlated with triglyceridemia (p = 0.049). CONCLUSIONS: The evaluation of various forms of vitamin D and VDBP in different population groups seems to have significant clinical value in evaluating the prevalence of metabolic disorders.

Hypovitaminosis D and adipose tissue - cause and effect relationships in obesity.

In recent years, attention has been focused on pleiotropic directions of effects exerted by vitamin D. Epidemiological data indicate that deficiency of vitamin D in various population groups represents an increasingly widespread phenomenon, while a decreased serum concentration of calcitriol correlates with manifestation of civilization-linked diseases, including visceral obesity. This study aims at a review and synthesis of data linked to relationships between lowered vitamin D concentrations in blood and manifestation of obesity, and potential mechanisms which affect the concentration of the vitamin in conditions of an excessive accumulation of adipose tissue. Several variables are distinguished which can affect the status of vitamin D in obesity, but the key role in this respect is ascribed to the metabolic activity of visceral adipose tissue. Among others, the activity favours sequestration and modulation of calcitriol turnover. On the other hand, the effects of vitamin D on the process of adipogenesis and its involvement in remodelling of adipose tissue are pointed out. Also, several factors of an environmental nature (e.g. time of year/day, dietetic supply of vitamin D), genetic nature (e.g. genetic polymorphisms) and other conditioning (e.g. coexisting diseases, age, content of melanin in skin) cannot be bypassed as they may affect the concentration of vitamin D. Nevertheless, it still remains unresolved to what extent hypovitaminosis D represents the cause and to which it is the effect of obesity.

Concentrations of omentin and vaspin versus insulin resistance in obese individuals.

INTRODUCTION: Omentin and vaspin are adipokines manifesting a potentially protective action against obesity-associated metabolic disturbances. AIM: Evaluation of relationship between serum concentrations of omentin and vaspin on one hand and indices of insulin resistance and anthropometric parameters in obese individuals on the other. MATERIAL AND METHODS: The studies were conducted on 64 individuals. The investigated group (37 obese patients) included the subgroup with normal glucose tolerance (NGT) and with abnormal glucose tolerance (AGT). The control group (n=27) included healthy individuals with normal body weight. In all participants anthropometric analyses and biochemical tests, including estimation of omentin and vaspin concentrations were performed, and insulin resistance by HOMA-IR was evaluated. RESULTS: Concentrations of examined adipokines manifested no significant differences between the examined groups. Median values of the index defining ratio between studied adipokine and degree of insulin resistance, i.e. omentin/HOMA-IR, proved to be different in the investigated and the control group while no such difference could be noted in cases of vaspin/HOMA-IR indices. In the studied population a negative relationship was detected between serum concentration of omentin and systolic blood pressure (p<0.04). Values of omentin/HOMA-IR index manifested a correlation with values of most anthropometric parameters (p<0.0001), blood pressure (p<0.0001) concentrations of TG (p<000.1) and HDL (p<0.0001), ISIbasal (p<0.00001), ISIgly (p<0.0001), Quicki (p<0.00001) and fasting insulinaemia (p<0.00001). In the case of vaspin/HOMA-IR index only its positive relationship with HDL concentration was noted (p<0.05). CONCLUSION: In context of date of correlation, multiple regression and values of area of under receiver operating characteristics curve omentin, as compared to vaspin, seems to provide a better predictor of insulin resistance in obese individuals.

The use of low-carbohydrate diet in type 2 diabetes - benefits and risks.

The pharmacological treatment of type 2 diabetes is increasingly being supported by the recommendation of an appropriate diet. The purpose of this study is to identify the potential benefits and risks arising from the use of one of the modern models of low-carbohydrate diet in patients with type 2 diabetes. Research shows that diet can favourably affect the health of diabetic patients. It has been shown that diet affects positively the concentration of blood glucose, glycosylated haemoglobin, and also contributes to the reduction of insulin taken in the course of drug therapy. At the same time, short-term studies have demonstrated a positive relationship of nutrition with reduction in body weight, as well as favourable changes in lipid profile of HDL cholesterol and levels of triglyceride. Attention is also drawn to the negative health effects of a low-carbohydrate diet; these include an increased risk of mineral deficiency, hypovitaminosis and reduced intake of dietary fibres. This diet may be associated with very high levels of protein which, in turn, raises the risk of renal dysfunction and the appearance of irregularities in the water and electrolyte balance. The impact of changes in the skeletal system and the development of osteopenia and osteoporosis is also observed. Besides the positive impact of this model of diet on the lipid profile parameters, its use significantly increases the risk of adverse changes in other markers predisposing to atherosclerosis occurring in individuals with type 2 diabetes. In composing a nutrition model for diabetes patients, both the benefits and potential risks of a low-carbohydrate diet should therefore take into account. At the same time, it is important to individualize the diet used, based on the current state of health, used pharmacological treatments, as well as taking into account the individual characteristics of the patient.

The influence of natural feeding on human health: short- and long-term perspectives.

Breastfeeding is the most appropriate way to nourish infants. It promotes proper physical and intellectual development of the child. Human milk is unique and impossible to replicate with any other kind of food. However, using maternal milk not only has beneficial effects on the infant's health but it can also help to prevent illnesses in adulthood. Breastfeeding improves immunity and consequently decreases the occurrence of infections, especially those of the gastrointestinal tract and respiratory tract. Moreover, it helps to reduce the risk of some disorders such as allergies, diabetes mellitus type 1, obesity and arterial hypertension.

Benefits and risks associated with genetically modified food products.

Scientists employing methods of genetic engineering have developed a new group of living organisms, termed 'modified organisms', which found application in, among others, medicine, the pharmaceutical industry and food distribution. The introduction of transgenic products to the food market resulted in them becoming a controversial topic, with their proponents and contestants. The presented study aims to systematize objective data on the potential benefits and risks resulting from the consumption of transgenic food. Genetic modifications of plants and animals are justified by the potential for improvement of the food situation worldwide, an increase in yield crops, an increase in the nutritional value of food, and the development of pharmaceutical preparations of proven clinical significance. In the opinions of critics, however, transgenic food may unfavourably affect the health of consumers. Therefore, particular attention was devoted to the short- and long-lasting undesirable effects, such as alimentary allergies, synthesis of toxic agents or resistance to antibiotics. Examples arguing for the justified character of genetic modifications and cases proving that their use can be dangerous are innumerable. In view of the presented facts, however, complex studies are indispensable which, in a reliable way, evaluate effects linked to the consumption of food produced with the application of genetic engineering techniques. Whether one backs up or negates transgenic products, the choice between traditional and non-conventional food remains to be decided exclusively by the consumers.

Influence of prednisolone on glucose and uric acid transport across peritoneal membrane in vitro.

Prednisolone and other glucocorticosteroids are used by some peritoneal dialysis patients because of underlying diseases such as peritonitis. Although corticosteroids are potent inhibitors of various processes during inflammation, their influence on the transport properties of peritoneum is little known. Our study investigated the influence of prednisolone (0.001 g/dL) on glucose (1.8 g/dL) and uric acid (0.02 g/dL) transfer across isolated parietal peritoneum taken from the anterior abdominal wall of white Hyplus 59 rabbits and placed inside a modified Ussing-type chamber. Values for transfer from the interstitial (I) to the mesothelial (M) side of membrane (I-->M) and in the opposite direction (M-->I) were calculated using the mathematical model of mass transport and are expressed as a coefficient of diffusive permeability [P (in centimeters per second)]. Four separate series of experiments were done. In the first and second series, we respectively examined glucose transport under control conditions (for 120 minutes) and then before (15-60 minutes) and after (75-120 minutes) introduction of prednisolone on the M side of the membrane. In the third and fourth series, similar studies of uric acid transfer were done. In the control (first and third) series, the stability of bidirectional transport for solute of interest was observed. The values of P +/- standard error of the mean (all x0.0001) for I-->M and M-->I transfer of glucose were, respectively, 2.489 +/- 0.329 cm/s and 2.259 +/- 0.493 cm/s. In the case of uric acid, the transport values were lower and amounted 1.936 +/- 0.324 cm/s and 1.895 +/- 0.596 cm/s for I-->M and M-->I respectively. Application of prednisolone on the M side of membrane lowered bidirectional transfer of glucose across peritoneal membrane by a mean of 73% (p < 0.02) and transport of uric acid by a mean of 19% (p < 0.003). These results show that, in vitro, prednisolone lowers glucose and uric acid transport across the peritoneal membrane, modifying the transfer dynamics of glucose to a greater extent. These observations may have clinical importance, especially in patients with disorders of peritoneal permeability, diabetes, and hyperuricemia.

Influence of osmotic and oncotic factors on gentamicin and insulin transport across the peritoneal membrane in vitro.

Glucose or its polymer is usually added to dialysis solution for the development of sufficient ultrafiltration during peritoneal dialysis. The aim of the present study was to determine the influence of glucose and icodextrin on the transport of gentamicin and insulin from the mesothelial to the interstitial side of the peritoneal membrane. Transfer values are expressed as a coefficient of diffusive permeability, P, in centimeters per second. Each of the molecules was tested in 3 series of experiments using rabbit parietal peritoneum, a modified Ussing chamber, and a mathematical model of mass transport. First, transperitoneal transfers of gentamicin (0.040 g/dL) and insulin (0.1 g/dL) were analyzed in control conditions for 120 minutes. Then, transport parameters for gentamicin and insulin were separately determined before (15-60 minutes) and after (75-120 minutes or 75-130 minutes) the application of glucose (1.8 g/dL) or icodextrin (2 g/ dL) on the mesothelial side of the peritoneal membrane. Insulin transport was observed to be stable in the control series. Gentamicin transfer was not stable; its passage declined by 52% (p < 0.01) in the control series. The mean transfer parameters were 7.41 +/- 1.40 cm/s (x0.0001) over 15-30 minutes and 3.21 +/- 0.54 cm/s (x0.0001) over 75-130 minutes. Gentamicin transfer declined less in the series with glucose or icodextrin, by 21% (p < 0.04) and 30% (p < 0.05) respectively, than in the control series. For insulin, the mean P (+ standard error of the mean) was 0.15 +/- 0.02 cm/s (x0.0001) at the first hour of transfer and 0.14 - 0.02 cm/s (x0.0001) at the second. Glucose induced a nonsignificant intensification of insulin transport. Icodextrin increased insulin passage by 107% (p < 0.03). Osmotic and oncotic factors (glucose and icodextrin) both stabilize the transfer of gentamicin across the peritoneal membrane in vitro. Glucose polymer intensifies insulin transport from the mesothelial to the interstitial side of the peritoneum. Similar modifications might be observed in vivo during peritoneal dialysis or continuous intraperitoneal administration of insulin, influencing the efficiency of those treatments.

Transperitoneal transport of uric acid: impact of p-cresol, sodium hyaluronan, and sodium deoxycholate in vitro.

Our study investigated uric acid transport across isolated parietal peritoneum taken from the anterior abdominal wall of white New Zealand rabbits and placed inside a modified Ussing-type chamber. Values for transfer from the mesothelial to the interstitial side of membrane (M --> I) were calculated using the mathematical model of mass transport and are expressed as a coefficient of diffusive permeability [P (in centimeters per second)]. Four separate series of experiments were done. In the first series, we examined uric acid transfer in control conditions (for 120 minutes). In the second and third series, P was calculated before (15 - 60 minutes) and after introduction of p-cresol (0.005 g/dL) or sodium hyaluronan (0.04 g/dL) on the M side of the membrane. In the fourth series, transfer parameters were measured before (15 - 75 minutes) and after (90 - 150 minutes) application of sodium deoxycholate (0.104 g/dL). The dynamics of transperitoneal transport of uric acid were stable. The values of P +/- standard error of the mean (x0.0001) were 1.936 +/- 0.324 cm/s and 2.078 +/- 0.186 cm/s. Application of p-cresol on the M side of membrane lowered uric acid transport by 10%. Application of sodium hyaluronan produced no change, but application of sodium deoxycholate increased the transfer of uric acid by 155%. These observations may have clinical importance.

Urea transport across peritoneal membrane in vitro: influence of protamine sulfate, glyoxal, and methylglyoxal.

Charge factors and reactive carbonyl solutes may change peritoneal structure and the transport properties of peritoneum. The aim of the present study to analyze the influence of polycationic protamine and glucose degradation products on the diffusive permeability (P) of peritoneal membrane for urea in vitro. Values for diffusion from the interstitial (1) to the mesothelial (M) side of the membrane and in opposite direction are expressed as coefficients of diffusive permeability. Four separate series of experiments were conducted. In the first experiment, transperitoneal transfer of urea (20 mg/dL) in control conditions over 120 minutes was analyzed. In the subsequent three experiments, transport parameters were analyzed before (15 - 60 minutes) and after (75 - 120 minutes) the addition of chemical factors (protamine sulfate 5 mg/dL, glyoxal 10 mg/dL, methylglyoxal 1 mg/dL) on the mesothelial side of the peritoneal membrane. Stability of urea transport was observed in the control series (120 minutes). The mean diffusive permeability coefficients (P = standard error of the mean) were 2.293 +/- 0.211 cm/s and 2.621 +/- 0.457 cm/s (x0.0001) for I --> M and M --> I transfer respectively. Protamine and methylglyoxal did not alter transport, but glyoxal lowered urea M --> I transport by 12% (p < 0.01), with a statistically nonsignificant reduction in opposite direction. Similar modifications are observed in vivo during peritoneal dialysis and may influence the efficiency of renal replacement therapy.

[Problems of peritoneal dialysis--history and research perspectives]. / Problemy dializy otrzewnowej--historia i perspektywy badan.

This paper specifies the peritoneal dialysis problems as a method of renal replacement therapy in a historical perspective. It pointed out to the dynamic development of peritoneal dialysis in the nineties and distinct slump of the presented treatment form at the turn of XXth and XXIst century, despite substantial progress in the dialysis techniques, effectiveness and biocompatibility of the therapy as well as a detailed evaluation of peritoneal function in vivo and in vitro. It showed descriptions and outline of the peritoneal cavity dating from ancient times, 19th-century animal experiments determining essential laws of peritoneal absorption and removal molecules, as well as the first peritoneal dialysis of a man which took place at the beginning of the 20th-century. The technical problems and peritonitis were the fundamental limitations of this therapy employment in this phase of dialysis development. The application of Tenckhoffs catheter and the technique specified as continuous ambulatory peritoneal dialysis was the invention and at the same time, the turning point which decided about the considerable progress of the described method of dialysis in the nineties. In this period, the analyses concerning failures of the peritoneal transport functions and protection of peritoneum during its long-term use as a dialysis membrane dominated. These studies referred to not absolutely biocompatibility factors of the environment of the peritoneal cavity during peritoneal dialysis. Thence, proposed future directions of analyses include researches concerning components of dialysis solution to assure long-term preservation of peritoneal transport functions and its secretory properties. It is not excluded that experiments of applying the newest achievements of regenerative medicine, in the scope of genetic modification and implantation of mesothelial cells will be continued.

Hyaluronan influence on diffusive permeability of the peritoneum in vitro.

Hyaluronan (HA), an essential component of peritoneal extracellular matrix, participates in restoring peritoneal integrity and remodeling the peritoneum changed by prolonged peritoneal dialysis and repeated peritonitis episodes. The aim of the present study was to compare urea, creatinine, and uric acid transport across the peritoneal membrane in control conditions and after HA application. Experiments were undertaken using rabbit parietal peritoneum and a modified Ussing-type chamber. Values of the transfer directed from the interstitial to the mesothelial side of the membrane (I --> M) and in the opposite direction (M --> I) were expressed as coefficients of diffusive permeability P. Transperitoneal transport in control conditions (for 120 minutes) and transfer parameters before (15 - 60 minutes) and after HA application (2000 kDa, 0.04 g/dL, 75-120 minutes) were examined. In the control series, stability of bidirectional transport for urea (0.02 g/dL), creatinine (0.1 g/dL), and uric acid (0.02 g/dL) was observed. The values of P +/- standard error of the mean for I --> M and M --> I transfers were respectively 2.293 +/- 0.211 and 2.621 +/- 0.457 for urea, 1.522 +/- 0.102 and 1.865 +/- 0.244 for creatinine, and 1.936 +/- 0.324 and 2.078 +/- 0.186 for uric acid [all x 10(-4) cm/s]. Application of HA reduced bi-directional urea transport by a mean of 12%, but did not change the P for creatinine and uric acid. These results show that in vitro HA modifies the dynamics of transport for certain small solutes.