The effects of four-site intrastriatal 6-hydroxydopamine (6-OHDA) lesions were examined in adult male rats. Five days after the lesions the animals were checked for specific rotational behavior induced by middle dose of amphetamine and the results confirmed the effectiveness of the lesions. The RNAs from the striatum were isolated at different time points after the lesion, and the RT-PCR analyse were performed for the D1 and D2 receptor mRNA. The results show a decline in the D2 receptor mRNA level (40%) at 6 h and 24 h points while this change was not observed seven days after the lesion. In contrast, no statistically significant changes in the level of the D1 receptor mRNA after the lesion at any time point were found.
In this study we measured the effects of eight-week atherogenic diet on plasma lipid status, glutathione- S-transferase activity, red blood cells-catalase activity, and glutathione and vitamin E plasma level adult male Wistar albino rats. The animals were sacrificed by decapitation 24 h after the end of the diet. Triglycerides, total cholesterol, and LDL cholesterol plasma levels, as well as LDL/HDL ratio, and vitamin E plasma level significantly raised (p<0,05) after the diet in comparison with the controls. HDL cholesterol plasma level glutathione- -S-transferase and red blood cells-catalase activities, and glutathione plasma level remained unchanged (p>0,05). These findings demonstrated that prolonged specific atherogenic diet in rats induced significant raise of the lipid parameters, but did not affect blood antioxidant status.
The subject of these studies was the thyroid gland tissue of middle-aged (14-month-old) female rats chronically treated with calcium glucoheptonate. The peripheral and central zone of the thyroids were stereologically analysed and the following morphometric parameters determined: the height and volumetric density of follicular epithelium, colloid, interstitium and follicles and index of activation rate. The height of follicular epithelium, its volume density and index of activation rate were significantly reduced (by 8%, p < 0.05, 18%, p < 0.025 and 34%, p < 0.01, respectively) as compared to the controls. However, the volumetric density of colloid and interstitium were increased (by 10% and 14% respectively). These morphometric results indicate that Ca treatment expressed an inhibitory effect on thyroid follicular cells structure in middle-aged female rats.
Proteinuria causes damage to proximal tubular cells. To investigate the influence of different levels of glomerular proteinuria, we examined 50 patients (24 male and 26 female). Their creatinine clearance (Ccr) was higher than 50 mL/min (87,29"31,17 mL/min). According to the proteinuria range level patients were separated in three groups. The first group, with proteinuria less than 0,3 g/24h, included 19 persons (7 man and 12 woman), mean age 45,12"13,28 years and mean Ccr 94,27"34,70 mL/min. Proteinuria 0,3?3,0 g/24h is the second group characteristic. This group included 18 patients (8 male and 10 female) mean age 45,39"12,64 years, with mean 90,07"31,89 mL/min. Patients with proteinuria higher than 3,0 g/24h were members of third group. Mean age 50,08"13,73 years and mean Ccr 73,25"20,44 mL/min are caracteristics of 13 members (9 male and 4 female) of the third group. Enzymes alkaline phosphatase (AP), g-glutamil transpherase (gGT) and Nacetyl- b-D-glucosaminidase (b-NAG) were used as parameters of tubular damage. Gama-glutamil transpherase is more sensitive parameter of tubular damage then alkaline phosphatase. N-acetyl-b-D-glucosaminidase is the most sensitive parameter of tubular damage due to proteinuria.
Basal glomerular membrane represents mechanical and electrical obstacle for passing of plasma proteins. In physiological conditions only plasma proteins of low molecule weight are completely filtered through basal membrane. Due to damages of basal glomerular membrane there is increase in filtration of plasma protein of middle and high molecular weight. Depending on etiology of proteinuria it can be prerenal, renal and postrenal. By analyzing albumin a1-microglobulin, immunoglobulin G and a2-macroglobulin, together with total protein in urine, it is possible to detect and differentiate causes of prerenal, glomerular, tubular and postrenal proteinuria. The adequate and early differentiation of proteinuria is of an immense diagnostic and therapeutic importance.
The structure and function of C cells of adult female rats after ovariectomy (Ovx) were investigated. Intact control and Ovx rats were i.p. treated with sterile olive oil for 4 weeks. Peroxidase-antiperoxidase (PAP) immunohistochemical procedure was applied to localize calcitonin (CT) in thyroid C cells while its serum content was determined by RIA method. Morphometric analyses of the C cells volume, that of their nuclei and relative volume density included stereological method with the multipurpose test system M-42. Also, the average number of C cells number per mm(2) was calculated. Ovx led to a significant increase in body weight (21%; p<0.005). At the same time the C cells of Ovx rats had a significantly decreased cell volume (13%; p<0.005) and their number per mm2 was increased by 59% (p<0.001) in comparison with the controls. Ovx resulted in reduction of serum CT level by 45% comparing to the corresponding controls. Based on these data it can be concluded that Ovx inhibits both the structure and function of the C cells.
This paper explains general requirements that testing laboratories should fulfill in order to confirm their competence in the certain field of testing according to the international standard ISO/IEC 17025. The requirements of the standard are separated in two main groups: management requirements and technical requirements. Management requirements can be implemented in the similar way in many testing laboratories, since they consider elements, common for all business systems. A laboratory should pay special attention to the fulfillment of technical requirements. In addition to the requirements of the standard, within each test area exist other applicable legislation. Each laboratory should establish its own goals and needs taking into account the requirements of business environment and legislative that has to be implemented.
After statistical analysis of biochemical parameters in 60 patients with acute leukaemia, it was concluded that most prominent alterations were elevated values of serum lactate-dehydrogenase, uric acid and calcaemia. In patients with acute myeloid leukaemia, prothrombin time and partial thromboplastin time were significantly prolonged, and in patients with acute lymphocytic leukaemia serum immunoglobuline levels were significantly lower. Biochemical alterations may produce some implications for the general state of the patient, as well as for the clinical course of the disease, its complications and outcome, with possible influence on the effect of therapy.
In the present study we employed Nw-nitro-L-arginine methyl ester, non-specific potent nitric oxide synthase inhibitor and a selective inhibitor of neuronal nitric oxide synthase, 7-nitroindazole, reportedly to investigate the possible involvement of nitric oxide in quinolinic acid-induced striatal toxicity in the rat. Quinolinic acid was administered unilaterally into striatum of adult Wistar rats in the single dose of 150 nmol/L. The other two group of animals were pretreated with Nw-nitro-L-arginine methyl ester and 7-nitroindazole respectively. Control groups of animals were treated with 0,154 mmol/L saline solution likewise. Nitrite levels was decreased in the ipsi- and contralateral striatum and forebrain cortex in the group treated with nitric oxide synthase inhibitors and neurotoxin compared to quinolinic acid-treated animals. In the same structures, activity of glucose-6-phosphate dehydrogenase was also decreased, compared to quinolinic acid-treated animals. These results indicate that application of the nitric oxide synthase inhibitors, supressed nitrite accumulation and glucose-6-phosphate dehydrogenase activity and attenuated quinolinic acid-induced neuronal damage in the striatum and forebrain cortex.
In order to find the essential structural motif of the D2L dopamine receptor necessary for the interaction with a-subunit of Gi1 protein, four fragments of the third cytoplasmic loop (CPL3) of this receptor were cloned, expressed in E. coli and purified. After that, fusion proteins with glutathione-S-transferase (GST) were prepared and the interactions quantified by a colorimetric assay for GST activity determination. The presence of D2L-CPL3 fragment-Gia1 complexes was detected by SDS-polyacrylamide gel electrophoresis (PAGE). Kd values for the interaction of the three fragments with Gia1 were similar and in nmol/L range of concentrations, while the peptide representing the insert in the long form of the dopamine D2 receptor expressed about 10-fold lower binding affinity. These results could serve to design new therapeutic agents that might act at the level of receptor/G protein interaction rather than at the level of ligand-receptor binding.
Protection management of working environment in the laboratories may be implemented only through efficient control of all laboratory hazards, which may be manifested at any time. The protection involves first of all the recognition of the hazards and is implemented by reasonable approach, good behaviour of the personnel, adequate work process in all laboatories and continuing application of good laboratory practice and techniques in the laboatory work. The responsibility for the implementation of safety measures lies primanly on the head of the laboratory i.e. employer but also on the entire personnel. Each clinical-biochemical laboratory must have an official protection programme. Besides, it is upon the employer to provide reliable laboratory procedures, constant, supervision over the work of the employees, information on the manner of protection, training, protective equipment and medical protection for the personnel.
This paper reports a case of beta-thalassaemia major whose molecular diagnosis was achieved by using modern methods of molecular genetics. This example demonstrates the strategy we chose to detect beta-thalassaemia mutations in the Republic of Serbia in order to complete molecular screening in our population and to make prenatal diagnosis in pregnancies at risk. The analysis of genomic DNA isolated from the blood of patient affected with thalassaemia major is carried out by the methods: RDB (reverse dot blot) and ARMS (amplification refractory mutation system). It is shown that the patient is a compound heterozygote for two beta-thalassaemic mutations: beta+IVSI-110 and beta+IVSI-6.
Some metabolic and endocrine consequences of portacaval shunt were examined in rats eight weeks after the operation. Plasma levels of insulin, glucagon somatostatin, such as pancreatic content of insulin, glucagon, and somatostatin were determined by radioimmunoassay. Numerous biochemical parameters, such as the concentration of serum ammonia, transaminase (AST and ALT), urea bilirubin, total plasma protein and plasma albumin levels were determined by standard biochemical tests. Normal plasma levels of insulin and somatostatin hyperglucagonaemia were observed in rats with portacaval shunt. After portacaval shunt there was a highly significant increase (p<0.01) in levels of blood ammonia, AST and ALT. Serum fasting glucose levels were significantly lower in portacaval shunt rats (p<0.01) in comparison to controls and sham operated rats. We conclude that the metabolic and endocrine consequences of portacaval shunt in rats are probably related to the functional deterioration of the liver due to diversion of the portal blood in systemic circulation.
Alterations of insulin-like growth factors (IGF-I and -II) and their binding proteins (IGFBP) in patients infected with Helicobacter pylori or Francisella tularensis are reported in this paper. Infections were diagnosed immunochemically, by determination of specific antibodies to each bacterial species. It was shown that IGF-I, IGF-II and IGFBP-3 concentrations were lower in patients with bacterial infections, while IGFBP-2 concentration increased in comparison with healthy adults. Although the effect was more pronounced in the case of H. pylori infection, statistically significant reductions of IGF-I and IGF-II were found in both groups of patients. For IGF-I p < 0.0001 and for IGF-II p = 0.037 in patients with H. pylori, while p = 0.017 and p = 0.032 in patients with F. tularensis. Alterations of the IGF system can be regarded as a combined effect of bacterial infection on immuno, gastrointestinal, hepatobiliary and nutritional axes in the organism.
The aim of this study was to examine urinary iodine excretion from the 125I-RIA-INEP laboratory personnel. Radiodosimetric measurements have shown that people received ionization energy doses that were significantly bellow the permissible levels, i.e. 0.15 - 0.45 mSv. The amount of iodide in urine varied from 123 to 396 mg/L (1.0 - 3.2 mmol/L) and the mean value was 264 mg/L (2.1 mmol/L; n = 25, SD = 75.3 mg/L or 0.60 mmol/L, CV = 28.5 %). On the basis of the obtained data it can be concluded that professionaly exposed individuals in the examined laboratory consume sufficient amount of dietary iodine, thus minimizing a risk of internal accumulation of 125I.
Hypothyroidism is associated with dislipidaemia and an increased risk of atherosclerosis. The aim of this study was to examine the effect of disease and long-term levothyroxine replacement therapy on serum lipids in hypothyroid children. We measured concentrations of total cholesterol, HDL-cholesterol LDL-cholesterol, triglycerides and thyroid-stimulating hormone in serum samples of 58 children with hypothyroidism (before and after therapy) and in 100 healthy controls. LDL-C and TC values were most markedly affected by the hypothyroid state. The values in the patients were on the average of 100% (LDL-C) and 54% (TC) higher than in the healthy controls. This finding is accordance with the known fact that LDL clearance is slower in hypothyroidism. TG concentrations were slightly higher (p<0.05) and HDL-C lower (p<0.02), but only in some age groups of patients. The effect of long-term L-T4 replacement on LDL-C and TC was quantitatively most pronounced. The values obtained in patients after therapy were markedly lower than before therapy and did not differ significantly from the values found in the corresponding age groups of healthy children. Significantly lower concentrations of HDL-C and TG after L-T4 administration were found only in children aged from 10 to 15 years. When we compared the lipid-lowering effect of L-T4 replacement therapy in normometabolic versus hypometabolic patients, we obtained a significantly greater effect on TC and LDL-C values in the normometabolic than in hypometabolic group (p<0.01). TC and LDL-C concentrations obtained in the L-T4 treated patients correlated well with the corresponding TSH levels (r = 0.770 and 0.725, respectively).
Patients with chronic renal insufficiency on hemodialysis develop lipoprotein abnormalities that may contribute to increased risk for atherosclerosis. The atherogenic risk for chronic renal insufficiency patients and dialysis treated patients was assessed by measuring total cholesterol, triglycerides HDL-cholesterol, LDLcholesterol and calculating the ratio: TC/HDL-C and LDL-C/HDL-C. The examined group consisted of 18 cronic renal insufficiency patients and 60 patients on hemodialysis. The results were compared to a control group of 85 voluntary blood donors. Serum lipid parameters were examined by standard methods. All lipid parameters in hemodialysis patients were statistically different compared to the control group (p<0.05) while chronic renal insufficiency patients showed significant difference only in triglycerides and HDL-cholesterol. Hypertriglyceridemia was present in both examined groups of patients and HDL-cholesterol was lower within both groups. All calculated atherogenic ratios were higher for patients than the control group. Lipid parameters were compared between chronic renal insufficiency and hemodialysis patients but statistical significantly difference was obtained only for HDL-cholesterol (p<0.05). We conclude that increased values of triglycerides and lower HDL-cholesterol in chronic renal insufficiency patients contribute to high incidence of cardiovascular disease. Chronic renal insufficiency patients have impaired reverse cholesterol transport from peripheral cells to lipoproteins, decreased levels of HDL-cholesterol hypertriglyceridemia prevalence of small, dense LDL and increased levels of potentially atherogenic remnant particles.
Evidence-based laboratory medicine (EBLM) is the use of the current best evidence of the utility of laboratory tests in making decisions about the care of individual patients. This practice means integrating laboratory and clinical experience with the last available external evidence from systematic research. It means that the definition of EBLM focuses on two key elements: experience and evidence from systematic research. Although the term evidence-based medicine (EBM) was created in Canada at Mc Master University by a group lad by Dr Gard Guyatt, there are various claims as to the origin of its practice. Regardless of its origins, many factors have come together over the past 30 years to drive the movement to EBM. One factor is those individual physicians, faced with numerous medical informations; the second factor is the global phenomenon of increasing health care costs and third is that patients who have generally more education, want the best in diagnostics and therapies. It means that evidence-based medicine has been driven by the need to cape with information overload, by cost-control, and by public impatient for the best in diagnostics and treatment. Clinical guidelines care maps, and outcome measures are quality improvement tools for the appropriateness, efficiency, and effectiveness of health services. Laboratory professionals must direct more effort to demonstrating the impact of laboratory tests on a greater variety of clinical outcomes. Evidence-based laboratory medicine aims to advise clinical diagnosis and management of disease through systematic researching and disseminating generalisible new knowledge that meets the standard of critical review on clinically effective practice of laboratory investigations. In laboratory medicine, the use of tests increases; new tests are constantly introduced, but >>old<< tests are seldom removed from the repertoire. This, together with limited public funds for the health care, should underline the challenge for laboratory professionals to provide evidence for the utility of different tests. This practice means integrating laboratory and clinical experience with the best available external evidence from systematic research therefore, it is important that advice given by laboratory medicine professionals are sound and based on evidence in the pre-analytical, analytical, and post-analytical phases of the diagnostic process. This paper provides an insight into the rationale, methodology and the phases of the EBLM.
In modern laboratory medicine there is a growing tendency for finding out the most specific and most sensitive biomarkers as indicators of a disease and diagnostic means for the follow-up treatment and therapeutical results. Detection of sensitive biomarkers was speeded up by world companies as manufacturers of diagnostic reagents. Today, the determination of some biochemical parameters is performed by immunodetermination which uses monoclonal antibodies and different markers, and thus achieving the desired high specificity of determination. The selections of biomarkers which are the most important for the clinical practice and which will give the best diagnostic information, requires large researches including analytical, clinical and economic properties. Thanks to statistical methods, especially to ROC analysis, the so-called cutoff-values are determined. On the basis of these values differentiation between sick people and healthy individuals is possible. In other words, the evaluation of clinical specificity requires also inclusion of patients whose clinical picture reflects the disease for which a marker is tested. The development and choice of biomarkers is also helped by IFCC with suggestion of the best procedures and preparation of reference materials. The use of selected biomarkers must be profitable in respect of the price and diagnostic information. In the paper the principles of selection, use, diagnostic and prognostic significance of biomarkers is discussed. The following biomarkers served as examples: cardiovascular (troponin T and I, myoglobin, CK-MB mass), bone (deoxypyridinolin, osteocalcin, C-terminal propeptide collagen, type I, osteo-alkaline-phosphase), malignant (PSA) and for pancreas diseases (lipase, PAM).
Receptors for estrogen and progesterone are accepted by international consensus as biomarkers of breast carcinoma responsiveness to endocrine therapy. Numerous current studies are aimed at consideration of importance of >>the new generation<< of estrogen-regulated biomarkers in treatment of breast cancer patients. Simultaneous knowledge of all these biomarkers may help in medical decision making. However, the amount of tumor material available from breast carcinoma can make impossible determination of estrogen-regulated biomarkes together with estrogen and progesterone receptors. To assess whether we could replace our current five-point ligand binding assay for measurement of estrogen and progesterone receptors with a single-point ligand binding assay, we compared simultaneous measurements in same samples of breast carcinomas by both methods, A linear regression analysis shows that single-point assay can be confidently used instead of five-point assay. In addition, there were no variations over time in estrogen and progesterone receptors phenotypes, as well as in estrogen and progesterone receptors contents determined by single-point assay. Accordingly, the results clearly demonstrate the validity of intralaboratory quality control and give a possibility for the establishment of interlaboratory quality control of single-point ligand binding assay.
