The use of neural networks in evaluation of the direction and dynamics of changes in lipid parameters in kidney transplant patients on the Mediterranean diet.

OBJECTIVE: The objective of the study was to assess whether neural networks can be a tool useful in the evaluation of the effect of the Mediterranean diet (MD) on the direction and dynamics of selected parameters. DESIGN: Randomized, prospective study. SETTING: Outpatient Clinic of the Department of Nephrology, Transplantology, and Internal Medicine. PATIENTS AND INTERVENTION: The study group consisted of 21 patients after kidney transplantation whose diet complied with the MD; the control group included 16 patients (also after transplantation) on a low-fat diet, isocaloric with the study diet. MAIN OUTCOME MEASURES: Anthropometry, plasma lipids, chromatography of triacylglycerols and fatty acids, and activity of superoxide dismutase and catalase were measured in both groups. Statistical analysis was done with the SNN (Statistica Neural Networks) StatSoft software package. RESULTS: The advantage of neural networks is the possibility of the dynamic presentation of a process taking place in a biological system. In the MD group in the first months of use of the diet, the cholesterol level was reduced only in the group of young and middle-aged patients. This tendency was not observed among elderly patients, among whom a small reduction of the total cholesterol level was noted only at the end of the observation period. In control group at the beginning of the observation, the plasma total cholesterol level was proportional to the patient's age. After 6 months, the total cholesterol increased in young patients and redacted in the group of elderly patients. CONCLUSIONS: We concluded that the MD diet would be ideal for posttransplantation patients without serious pathologic dyslipidemia. In the case of patients with substantial dyslipidemia, appropriate pharmacologic treatment lowering proatherosclerotic lipid levels should be used in combination with the MD. Artificial neural networks (ANNs) were a useful tool in modeling biological parameters, showing dynamics of the studied interactions in a very detailed way. ANN is the most suitable method for investigations with many variables, interconnected nonlinearly; therefore, this method allows for a more general approach to biological problems. However, it should be noted that considerable data sets are required to obtain a satisfactory fit to the data. Moreover, to ensure the predictive power of this method for new cases, the representative database is indispensable. In spite of these demands, ANN is a prospective tool for reliable, quick assessments and predictions.     

Osteoglophonic dysplasia: appearance and progression of multiple nonossifying fibromata

The appearance and gradual enlargement of fibrous cortical defects and multiple nonossifying fibromata are documented in this report of a 2-year-old boy with a very rare skeletal dysplasia known as osteoglophonic dysplasia, characterized by multiple and recurrent craniosynostoses, platyspondyly, short tubular bones, and epiphyseal dysplasia. Received: 10 November 1995 Accepted: 13 March 1996     

Effect of Hemodialysis on T Lymphocyte Subsets, Con-A-Activated Suppressor Cell Activity, and Interleukin-2 Receptor Expression on Lymphocytes in Chronic Uremic Patients

Effect of hemodialysis (HD) on some indices of immune response was studied in nine chronic uremics. Total lymphocyte, OKT4+, and OKT8+ cell numbers significantly decreased during the first 20 min of HD, and they were decreased till the third hour of the procedure, whereas the OKT4+/OKT8+ cell number ratio did not change significantly. Before HD, Con-A--activated suppressor cells exerted a stimulatory action on autologous responder cells measured in two-step culture. During HD, Con-A-activated suppressor cell activity transiently appeared, with its peak at 60 min after the start of HD. It was accompanied by a transient rise in lymphocyte count with spontaneous interleukin-2 (IL-2) receptor expression, whereas the number of cells expressing IL-2 receptor following phytohemaglutinin (PHA) stimulation was progressively decreased during HD. A significant correlation was found between the increment of Con-A-activated suppressor cell activity and the increment of spontaneous IL-2 receptor expression on lymphocytes during one single blood flow through the dialyzer. The results supply further evidence that HD may impose additional disturbances on immune regulation in chronic uremics.     

The influence of gender, weight, height and BMI on pentosidine concentrations in plasma of hemodialyzed patients

BACKGROUND/AIMS: Advanced glycation end-products (AGEs) such as pentosidine play an important role in complications associated with chronic renal failure (CRF) and hemodialysis (HD). This study was undertaken to determine the influence of anthropometric parameters and inflammation on plasma pentosidine concentrations. METHODS: We measured total and free pentosidine in the plasma of 49 patients on chronic HD. Acid hydrolysis of plasma and protein precipitation with trichloroacetic acid was done in the case of total and free pentosidine, respectively. Pentosidine was measured by high performance liquid chromatography (HPLC). C-reactive protein (CRP) was measured by the nephelometric method. RESULTS: A strong negative correlation between dry weight and mean concentration of total pentosidine before and after HD was found (R = -0.47, p < 0.001). This correlation was stronger in males (R = -0.47, p = 0.017) than females (R = -0.34, p = 0.10). Even stronger correlations were noted between body mass index (BMI) and total (R = -0.55, p < 0.001), as well as free (R = -0.39, p = 0.01) pentosidine. Multivariate analysis demonstrated that BMI and time on HD were two independent factors influencing total pentosidine concentrations. CRP did not correlate with pentosidine or BMI. CONCLUSIONS: Lower BMI values are associated with significantly higher plasma pentosidine concentrations in patients on HD. Presumably this relationship is mediated by hypercatabolism observed in these patients. Catabolism produces weight loss and reduces BMI concurrently with the induction of oxidative and carbonyl stresses that stimulate the generation of pentosidine and other harmful AGEs in dialyzed patients.     

Impact of presence of HBs antigen and anti-hepatitis C virus and anti-cytomegalovirus antibodies on transplanted kidney survival

INTRODUCTION: Infections are one of the most common complications after organ transplantation. Viral infections such as hepatitis type B (HBV) and C (HCV) or cytomegalovirus (CMV) infections are among the most serious ones. A high frequency of HBV and HCV infections has been recognized in kidney recipients. Viral infections play a special role in graft recipients because of clinical symptoms influencing graft function and recipient survival. Immunosuppressive treatment to decrease immunological reactions after organ transplantation may increase the risk of viral infections. The aim of this study was to evaluate the impact of the presence of HBs antigen and HCV and CMV antibodies on patient and graft survivals. MATERIAL AND METHODS: Two hundred one enrolled kidney transplantation patients (96 women and 105 men) were treated with the same immunosuppressive regimen. Age, sex, and viral state (HBs antigen, anti-HCV and anti-CMV antibodies) were evaluated in every patient. Statistical analysis was performed with the Gompertz model, Kaplan-Meier curves and Cox proportional hazard tests. RESULTS: The presence of HBs antigen was detected in 161 patients (20.4%), HCV antibodies in 61 recipients (30.3%); and CMV antibodies in 12 patients (5.9%). Eighty-seven recipients (43.4%) were seronegative. Average recipient age was 38.5 years. CONCLUSION: Time of graft function was independent of the presence of HBs antigen or HCV or CMV antibodies.     

Hypoxanthine as a graft ischemia marker stimulates catalase activity in the renal vein during reperfusion in humans

BACKGROUND: The impairment of organ function derived from ischemia-reperfusion injury is still an important problem in solid organ transplantation. Cell alterations induced by ischemia prime the tissue for subsequent damage occurring during the reperfusion phase. Purine nucleotides and oxypurines are products of adenine nucleotide degradation. Reperfusion and reoxygenation are characterized by great production of reactive oxygen species and free radicals. On the contrary, superoxide dismutase, catalase, glutathione, and glutathione peroxidase are involved in protecting against free radicals. The aim of the study was to examine the correlation between concentrations of ischemia markers (hypoxanthine or inosine) and the activity of erythrocyte superoxide dismutase, catalase, or glutathione peroxidase. PATIENTS AND METHODS: The study included 40 renal transplant recipients. Before anastomosis of the kidney vessels with the recipient's iliac vessels, a "0" blood sample was taken from the iliac vein. Then, after anastomosis, the renal vein of the graft was cannulated and blood samples I, II, and III were obtained. The reperfusion of the transplanted kidney was measured with a thermovision camera ThermaCAM SC500. RESULTS: The plasma concentrations of hypoxanthine and inosine increased in statistically significant fashion immediately after total tissue reperfusion (P < .0001). Catalase activity at 4 minutes after total tissue reperfusion correlated positively with hypoxanthine concentrations immediately after total tissue reperfusion (Rs = +0.49), 2 minutes after total tissue reperfusion (Rs = +0.47), and 4 minutes after total tissue reperfusion (Rs = +0.46). There were no statistically significant correlations between hypoxanthine or inosine concentrations or superoxide dismutase or glutathione peroxidase activities. CONCLUSIONS: The results of the present study suggest that catalase activity may correlate with the concentration of hypoxanthine in the graft renal vein and other mediators of oxidative stress.     

Risk assessment for preterm delivery in pregnant women with active periodontitis

INTRODUCTION: Premature labor has been regarded as a highly problematic clinical event not only due to its relation with perinatal mortality but also in the light of the remote results of the prematurity. Therefore many ongoing studies concentrate on evaluation of potentially avoidable risk factors of premature labor. Relatively few studies have suggested chronic periodontitis as such a determinant. OBJECTIVES: Prospective evaluation of periodontium changes in the course of otherwise normal pregnancy. Assessment of potential influence of periodontium pathology, and its severity, on the obstetrical complications. The authors have made literature search on the relation of active periodontitis and premature labor. MATERIALS AND METHODS: Study involved 120 randomized gravidae attending electively dental clinic for a routine control. Inclusion criteria: single pregnancy, no preterm delivery in a history, mother's age 18 to 35 years, gestational age 10 to 20 weeks based on a last menstrual period date--confirmed on ultrasound. Every patient underwent dental examination twice--at the inclusion date and 48 hours after delivery. Patients were divided into three groups. Group I (n = 25)--healthy patients. Group II (n = 61)--patients with mild or moderate periodontitis. Group III (n = 39) patients with a severe periodontitis. Progression of lesions was recognized if the post-delivery dental assessment revealed increase of the pockets depth higher than 2mm and in at least 4 places compared with the initial findings. RESULT: In the course of otherwise normal pregnancy women with signs of inflammation within periodontium revealed progression of this pathology proportional to its severity in early pregnancy. This increase was associated with 4-fold higher rate of preterm deliveries in Group II and 12-fold in Group III compared with healthy patients. CONCLUSION: Active and severe periodontitis should be regarded as independent and highly influential risk factor of the preterm delivery.     

Changes to the periodontium in postmenopausal women

Few up to date studies on the influence of hormonal replacement therapy (HRT) on periodontium has been conducted on small groups of patients and the conclusions made may require further investigation on a larger population. It has been widely accepted that decreased estrogen levels in postmenopausal women are associated with a gradual loss of a bone density and increased risk of a dental loss. Much less stress is put however on the fact that the same phenomenon, especially suboptimal levels of estradiol, may deteriorate periodontal tissue condition. The authors made a literature search on the influence of HRT on periodontium.