Effects of attentional focus and gaze instruction during observational learning of a basketball free-throw.

Observational learning has long been used to instruct individuals on how to perform a novice motor skill. Recently, research has shown a benefit to instructing learners to focus externally when viewing a video model (Asadi, Aiken, Heidari, & Kochackpour, 2021). Research has also highlighted the effectiveness of modeling correct gaze behaviors when learning a cognitive task (Jarodzka, van Gog, Dorr, Scheiter, & Gerjets, 2013). The purpose of the present study was to investigate the effectiveness of combining these two modalities. 40 individuals with a mean age of 21.77 ± 1.40 performed a novel motor task where they were asked to either focus internally or externally, and were provided with traditional instruction or were provided with an experienced performer's gaze behaviors while viewing a video demonstration. It was observed that both the external focus groups and the gaze instructed groups performed a basketball free-throw more accurately and had longer periods of quiet eye than an internal focus or traditional verbal instruction (p's < 0.05). Eye tracking also allowed for the assessment of attentional focus adherence. Participants focused on the instructed cues significantly more than irrelevant task aspects or a different focus types (p's < 0.05). These results highlight the effectiveness of cuing a learner to focus externally during observational learning. It also highlights the usefulness of providing correct gaze behaviors when observing a model.

The probiotic properties and potential of vaginal Lactobacillus spp. isolated from healthy women against some vaginal pathogens.

During the last decade, probiotic research has progressed considerably and significant advances have been made in the selection and characterization of specific probiotic strains. The most studied probiotics belong to the genus Lactobacillus. In this study, 80 Lactobacillus spp. isolated from healthy women tolerated low pH and were able to grow in the presence of bile salts. RAPD PCR technique resulted in the identification of 38 different types. These isolates were then evaluated based on adhesion capacity, antibiotic susceptibility and tolerance in simulated gastrointestinal tract. Species-specific PCR and detection of bacteriocin-related genes were also surveyed. Among the isolates, five strains-Lacticaseibacillus rhamnosus NO21, Lacticaseibacillus casei NO1, Lactiplantibacillus plantarum NO4, Lactobacillus acidophilus NO7 and Lactobacillus gasseri NO38-presented acceptable antibiotic susceptibility pattern. Further analysis showed antimicrobial activity of Lacticaseibacillus culture against various bacterial pathogens and real-time PCR showed all five strains were able to prevent the colonization of bacterial pathogens. All five selected strains produced organic acids, hydrogen peroxide and were resistant to the spermicide. In addition, they lacked haemolytic activity with the ability of hydrophobicity, auto-aggregation and co-aggregation with pathogens. These results suggest that the vaginal microbiome could be a good source for the isolation of probiotics and the strains of this study may be considered as good probiotic candidates.

The effect of attentional instructions during modeling on gaze behavior and throwing accuracy in 7 to 10 year-old children.

Research has shown the effectiveness of attentional instructions and observation on the performance and learning in children. However, there is little research on the effects of instruction that manipulates attentional focus during observation. The purpose of the study was to investigate performance following instructions that directed an individual to focus internally or externally during the viewing of a model. Eye tracking was also used to investigate the visual search strategy under different instructional groups. 24 children between the ages of 7 and 10 years were randomly divided into an internal (IFM) or external (EFM) modeling group. Children performed a 10-trial pre-test to measure throwing accuracy and quiet eye duration (QED). Following pre-test, children observed a model performing the correct overarm throw 10 times while eye movement was recorded. They then performed a 10-trial post-test. Results revealed that both groups improved accuracy from pre-test to post-test (p < .001) and increased QED from pre- to post-test (p < .001). It was also observed that EFM had greater accuracy and (p = .01) and longer QED (p < .001) than IFM during post-testing. Evidence was also observed for adherence to the attentional focus strategy as EFM and IFM looked more frequently at the specific cue provided (p < .001). Directing visual attention to the movement effects while observing a model significantly benefits motor performance and learning in children. Changing the focus of instruction to an external focus improved both throwing accuracy and increased QED.

A 3'-untranslated region variant (rs2289046) of insulin receptor substrate 2 gene is associated with susceptibility to nonalcoholic fatty liver disease.

PURPOSE: Nonalcoholic fatty liver disease (NAFLD) is an increasing global health concern defined by excessive hepatic fat content in the absence of excessive alcohol consumption. Regarding the key role of insulin and insulin resistance in NAFLD, we investigated whether insulin receptor substrate 1 (IRS1) and insulin receptor substrate 2 (IRS2) gene variants were associated with NAFLD risk. METHODS: In this case-control study, 305 subjects including 151 cases with biopsy-proven NAFLD and 154 controls were enrolled. All the subjects were genotyped for IRS1 (rs1801278) and IRS2 (rs2289046) gene variants using PCR-RFLP method. RESULTS: Our findings showed that the IRS2 rs2289046 "GG+AG" genotype compared with "AA" genotype to be a marker of decreased NAFLD susceptibility and the difference remained significant even after adjustment for confounding factors including age, BMI, sex, smoking status, systolic blood pressure, and diastolic blood pressure (P=0.014; OR=0.50, 95%CI= 0.29-0.87). Furthermore, the IRS2 "G" allele was significantly underrepresented in the cases with NAFLD than controls (P=0.026 ; OR=0.62, 95%CI=0.41-0.94). However, no significant difference was found for IRS1 rs1801278 gene variant. CONCLUSIONS: This study suggests, for the first time, that the IRS2 gene rs2289046 variant may play a role in NAFLD susceptibility. Nevertheless, this observation warrants further investigations in other populations.

Evaluation of Hepatitis B Vaccination among Lichen Planus Patients.

Lichen planus (LP) is an idiopathic chronic inflammatory mucocutaneous disease. Many reports in the literature have described hepatitis B vaccine as a predisposing factor for LP. This study was performed to determine the rate of previous vaccination against hepatitis B in LP patients. This was a cross sectional study on LP patients. Diagnosis of LP was confirmed by histological examination. Data were gathered by dermatology residents based on a checklist designed to guide their interview. Blood samples were tested for HBsAB titer, HBsAg, HCV Ab and liver function tests. One hundred & twenty four (124) patients entered the study. Females were 2.72 times more affected. The mean age of patients was 45.63 years (age range; 18-88). Forty-four (35.5%) patients had been vaccinated against hepatitis B. Lichen planus during the first six months of vaccination occurred in only one patient. Our findings bring into question the causative role of HBV vaccine in LP incidence in our population.

Responding to physical and psychological health impacts of disasters: case study of the Iranian disaster rehabilitation plan.

This paper describes the process of developing a national pre-disaster plan for physical health and psychological rehabilitation of disaster-stricken communities. Data gathered from a literature review and expert panel discussions informed the process of drawing up unified definitions of physical and psychological health rehabilitation, carrying out stakeholder and STEEP-V analyses, and assigning the responsible organization and the collaborative organizations for each task. The Ministry of Health and the Welfare Organization were selected as the two responsible organizations. Integrated management at all levels, and sharing information, education and funding, were identified as ways to improve stakeholders' participation and collaboration. A system is needed for evaluating the implementation of the disaster rehabilitation plan, using valid and reliable indicators.

High rate CNP removal from a milk processing wastewater in a single ultrasound augmented up-flow anaerobic/aerobic/anoxic bioreactor.

Simultaneous removal of carbon, nitrogen and phosphorus (CNP) in a single bioreactor is of high significance in terms of reactor volume and energy consumption. Therefore, in this study, an innovative up-flow anaerobic/aerobic/anoxic bioreactor (UAAASB) augmented by ultrasound was developed as a high rate single bioreactor for the simultaneous removal of nutrients from a milk processing wastewater. The ultrasonic irradiation used in this work was in the range of high frequency (1.7 MHz). The central composite design (CCD) and response surface methodology (RSM) were applied to design the experimental conditions, model obtained data, and optimize the process. The effects of three independent variables, i.e. hydraulic retention time (HRT), aeration mode and mixed liquor suspended solid (MLSS) concentration on 10 process responses were investigated. The results prove that the ultrasonic irradiation has a positive effect on the sludge settling velocity and effluent turbidity. The optimum conditions were determined as 12-15 h, 4000-5000 mg/l and 1.5-2 for HRT, MLSS concentration and aeration mode, respectively, based on removal efficiency of sCOD ⩾ 90%, TN and TP ⩾ 50%.

Extended covalent containers: synthesis and guest encapsulation.

The synthesis and characterization of two new covalent capsules are described. The structures use biphenyl and azobenzene spacers capped on both ends with deep cavitands. The tubular capsules are robust in a range of media and accommodate guests as long as squalene.

Performance of intermittently aerated up-flow sludge bed reactor and sequencing batch reactor treating industrial estate wastewater: a comparative study.

In this study, an innovative aerobic/anoxic sludge bed bioreactor with two feeding regimes, continuous-fed (an up-flow sludge bed reactor (USBR)) and batch fed (sequencing batch reactor (SBR)), was evaluated for the treatment of an industrial estate wastewater with low BOD(5)/COD ratio. The process performance in the two regimes was compared. Two numerical independent variables (retention/react time and aeration time) were selected to analyze, model and optimize the process. Response surface methodology with central composite design (CCD) was used with five levels of hydraulic retention time (HRT)/react time (12-36h) and aeration time (40-60min/h). In order to analyze the process, ten dependent parameters as the process responses were studied. As a result, HRT/react time showed a decreasing impact on the responses measured in both hydraulic regimes, USBR and SBR. The USBR showed better performance than the SBR in removal of total COD, slowly biodegradable COD, total nitrogen and total Kjeldahl nitrogen.

Simultaneous removal of carbon and nutrients from an industrial estate wastewater in a single up-flow aerobic/anoxic sludge bed (UAASB) bioreactor.

Simultaneous removal of carbon and nutrients (CNP) in a single bioreactor is highly significant for energy consumption and control of reactor volume. Basically, nutrients removal is dependant to the ratio of biochemical oxygen demand to chemical oxygen demand (BOD5/COD). Thus, in this study the treatment of an industrial estate wastewater with low BOD5/COD ratio in an up-flow aerobic/anoxic sludge bed (UAASB) bioreactor, with an intermittent regime in aeration and discharge, was investigated. Hydraulic retention time (HRT) of 12-36 h and aeration time of 40-60 min/h were selected as the operating variables to analyze, optimize and model the process. In order to analyze the process, 13 dependent parameters as the process responses were studied. From the results, it was found, increasing HRT decreases the CNP removal efficiencies. However, by increasing the BOD5 fraction of the feed, the total COD (TCOD), slowly biodegradable COD (sbCOD), readily biodegradable COD (rbCOD), total nitrogen (TN), and total phosphorus (TP) removal efficiencies were remarkably increased. Population of heterotrophic, nitrifying and denitrifying bacteria showed good agreement with the results obtained for TCOD and TN removal. The optimum conditions were determined as 12-15 h and 40-60 min/h for HRT and aeration time respectively.

Immunohistochemical characterisation of cells co-producing insulin and glucagon in the developing human pancreas.

AIMS/HYPOTHESIS: In adult human islets, insulin and glucagon production is largely restricted to individual cell populations. The production of these hormones is less segregated during development and during the differentiation of human pluripotent stem cells towards pancreatic lineages. We therefore sought to characterise the transcription factor profile of these cells that co-produce insulin and glucagon in the developing human pancreas, and thus to gain insight into their potential fate during normal pancreas development. METHODS: An immunohistochemical analysis was performed on human pancreas sections from fetal donors aged 9 to 21 weeks and from adult donors between the ages of 17 and 55 years. RESULTS: Endocrine cells were observed within the pancreas at all ages examined, with cells co-producing insulin and glucagon observed as early as 9 weeks of fetal age. The population of cells that co-produce insulin and glucagon generally decreased in prevalence with age, with negligible numbers in adult pancreas. From 9 to 16 weeks, the population of glucagon-only cells increased, while the insulin-only cells decreased in abundance. Cells that co-produced insulin and glucagon also produced the alpha cell transcription factor, aristaless related homeobox (ARX), and lacked the beta cell transcription factors pancreatic and duodenal homeobox 1 (PDX1), NK6 homeobox 1 (NKX6.1) and v-maf musculoaponeurotic fibrosarcoma oncogene homologue A (MAFA). CONCLUSIONS/INTERPRETATION: Our results indicate that cells co-producing insulin and glucagon in the developing human pancreas share a transcription factor profile that is similar to that of mature alpha cells and suggest that some maturing alpha cells briefly exhibit ectopic insulin expression. Thus cells that co-produce insulin and glucagon may represent a transient cell population, which gives rise to mature alpha cells.

Musashi expression in ß-cells coordinates insulin expression, apoptosis and proliferation in response to endoplasmic reticulum stress in diabetes.

Diabetes is associated with the death and dysfunction of insulin-producing pancreatic ß-cells. In other systems, Musashi genes regulate cell fate via Notch signaling, which we recently showed regulates ß-cell survival. Here we show for the first time that human and mouse adult islet cells express mRNA and protein of both Musashi isoforms, as well Numb/Notch/Hes/neurogenin-3 pathway components. Musashi expression was observed in insulin/glucagon double-positive cells during human fetal development and increased during directed differentiation of human embryonic stem cells (hESCs) to the pancreatic lineage. De-differentiation of ß-cells with activin A increased Msi1 expression. Endoplasmic reticulum (ER) stress increased Msi2 and Hes1, while it decreased Ins1 and Ins2 expression, revealing a molecular link between ER stress and ß-cell dedifferentiation in type 2 diabetes. These effects were independent of changes in Numb protein levels and Notch activation. Overexpression of MSI1 was sufficient to increase Hes1, stimulate proliferation, inhibit apoptosis and reduce insulin expression, whereas Msi1 knockdown had the converse effects on proliferation and insulin expression. Overexpression of MSI2 resulted in a decrease in MSI1 expression. Taken together, these results demonstrate overlapping, but distinct roles for Musashi-1 and Musashi-2 in the control of insulin expression and ß-cell proliferation. Our data also suggest that Musashi is a novel link between ER stress and the compensatory ß-cell proliferation and the loss of ß-cell gene expression seen in specific phases of the progression to type 2 diabetes.

Significance of blood-related high-risk behaviors and horizontal transmission of hepatitis B virus in Iran.

Hepatitis B virus (HBV) is a significant public health problem and a leading cause of morbidity and mortality, and approximately 30% of the world's population is infected with HBV. The objective of our study was to determine the seroprevalence of HBV and major risk factors associated with its occurrence. Four thousand eighty-seven healthy Iranian subjects aged 8-80 years were screened for HBV serological markers by an enzyme immunoassay method. A structured questionnaire was administered to all participants. Multiple logistic regression, an unpaired t-test for continuous data and the χ (2) test for categorical data were performed. A total of 4087 participants were tested for hepatitis B surface antigen (HBsAg), of which 62 (1.5%) were seropositive. Fifteen percent of the subjects were positive for anti-HBs, 6.3% were positive for isolated anti-HBc and 12.5% were positive for both anti-HBs and anti-HBc. Laborers showed a higher HBsAg(+) seroprevalence and risk compared with jobless participants (Pearson's = 8.276, P = 0.004; OR = 4.1, 95% CI: 1.5-11.2). Bivariate logistic regression revealed that the following variables were significantly associated with HBV seropositivity: phlebotomy (P = 0.002; OR = 5.0, 95% CI: 2.1-11.9), tattooing (P = 0.003; OR = 3.4, 95% CI: 1.6-7.0), intravenous drug use (P = 0.001; OR = 2.4, 95% CI: 1.4-4.1). The adjusted prevalence ratios remained significantly associated with HBV seropositivity and thus likely served as possible risk factors for HBV. The overall positive seroprevalence was 1.5%. Among the variables, only phlebotomy, tattooing and intravenous drug injection emerged as major potential risk factors for hepatitis B infection and responsible for transmission of the disease.

DsAAV8-mediated expression of glucagon-like peptide-1 in pancreatic beta-cells ameliorates streptozotocin-induced diabetes.

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that performs a wide array of well-characterized antidiabetic actions, including stimulation of glucose-dependent insulin secretion, upregulation of insulin gene expression and improvements in beta-cell survival. GLP-1-receptor agonists have been developed for treatment of diabetes; however, the short biological half-lives of these peptide-based therapeutics requires that frequent injections be administered to maintain sufficient circulating levels. Thus, novel methods of delivering GLP-1 remain an important avenue of active research. It has recently been demonstrated that self-complimentary, double-stranded, adeno-associated virus serotype-8 (DsAAV8) can efficiently transduce pancreatic beta-cells in vivo, resulting in long-term transgene expression. In this study, we engineered a DsAAV8 vector containing a GLP-1 transgene driven by the mouse insulin-II promoter (MIP). Biological activity of the GLP-1 produced from this transgene was assessed using a luciferase-based bioassay. DsAAV8-MIP-GLP-1 was delivered via intraperitoneal injection and beta-cell damage induced by multiple low dose streptozotocin (STZ) administration. Glucose tolerance was assessed following intraperitoneal glucose injections and beta-cell proliferation measured by PCNA expression. Expression of GLP-1 in Min6 beta-cells resulted in glucose-dependent secretion of biologically active GLP-1. Intraperitoneal delivery of DsAAV8-MIP-GLP-1 to mice led to localized GLP-1 expression in beta-cells and protection against development of diabetes induced by multiple low-dose STZ administration. This protection was associated with significant increase in beta-cell proliferation. Results from this study indicate that expression and secretion of GLP-1 from beta-cells in vivo via DsAAV8 represents a novel therapeutic strategy for treatment of diabetes.

Preparation of antibody against horseradish peroxidase using hybridoma technology.

BACKGROUND: Monoclonal antibody against horseradish peroxidase (HRP) has many applications which peroxidase anti-peroxidase. Peroxidase-antiperoxidase (PAP) complex formation is its most known and important usage. This complex is used in many immunohistochemical and immunocytochemical staining techniques. OBJECTIVE: The aim of this study was the preparation of anti-HRP monoclonal antibody through hybridoma technology. METHODS: The BALB/c mice were immunized by repeated injections of HRP. After the confirmation of their immunization by ELISA test, the spleen lymphocytes and SP2/0 myeloma cells were hybridized using PEG as fusing agent. The hybridoma cells were then selected by culturing in HAT medium. Identification and selection of anti-HRP producing clones were done by ELISA test on culture supernatants of the obtained clones. To acquire the monoclones, limiting dilution was performed twice and the effect of finally obtained antibodies on enzyme activity was investigated by a specific ELISA test. In vivo tumor induction method was used for production of concentrated antibody. At last class and subclass of the obtained antibodies were determined by Isostrip Kit. RESULTS: After seven rounds of cell fusions, 224 clones were obtained, from which, six ones were anti-HRP producers. Two clones (P1F11 and P2F6) with higher antibody secretion were selected and subcloned. Both derived hybridoma monoclones (P1F11D2 and P2F6F3) were producing antibodies from IgG1 subclass with kappa (Kappa) light chains which didn't affect the enzyme activity. The electrophoresis of ascetic fluid of tumor induced mice showed an obvious band in gamma (gamma) position. CONCLUSION: The obtained monoclonal antibodies are from IgG class and don't affect the enzyme activity, therefore it seems that they are suitable for PAP complex production.

Biochemical characterization of four novel mutations in the thyroid hormone receptor beta gene in patients with resistance to thyroid hormone.

In resistance to thyroid hormone (RTH), decreased tissue responsiveness to thyroid hormones is usually caused by mutations in the thyroid hormone receptor beta (THRB) gene. Subsequently, in serum the level of thyroid stimulating hormone (TSH) is not suppressed despite increased concentrations of thyroxine (T4) and triiodothyronine (T3). In our laboratory, DNA sequences of exon 7 to 10 in the THRB gene have been analysed in individuals with biochemical signs of RTH. Four novel point mutations were identified (I250T, A279E, T327A and L440P) and their effects on T3 binding activity characterized. The mutations were introduced into a vector carrying the wild-type THRB cDNA by in vitro mutagenesis. T3-binding activity was measured by a filter-binding assay procedure in receptors generated from the vector by in vitro transcription and translation. Specific binding was calculated as total activity subtracted by non-specific activity. The association constants (Ka) of the wildtype (WT) and mutant receptors were determined by Scatchard analysis. No specific T3-binding was observed for the receptor with the A279E mutation. The binding affinity was reduced by 74% in the T327A mutant and by about 50% in the I250T and L440P mutants compared to the WT receptor (Ka = 4.2 x 10(10) L/mol). The reduction of T3-binding affinity caused by the four mutations in our study is comparable to the effects of THRB gene mutations found in other patients with RTH and supports the assumption that the signs of RTH observed in our patients are caused by the mutations.

ESDN is a marker of vascular remodeling and regulator of cell proliferation in graft arteriosclerosis.

Vascular remodeling is a common feature of many vasculopathies, including graft arteriosclerosis (GA). We investigated whether endothelial and smooth muscle cell-derived neuropilin-like protein (ESDN) is a marker of vascular remodeling in GA. Immunostaining of human coronary arteries demonstrated high levels of ESDN in GA, but not in normal arteries. In a model of GA, where a segment of human coronary is transplanted into a severe combined immunodeficient mouse, followed by allogeneic human peripheral blood mononuclear cell (PBMC) reconstitution, ESDN was minimally expressed in transplanted human arteries in the absence of reconstitution. By 2 weeks following PBMC reconstitution, at a time corresponding to maximal vascular cell proliferation, high levels of ESDN were detected in the transplanted arteries. Similarly, injury-induced vascular remodeling in apoE(-/-) mice was associated with early and transient ESDN upregulation, in parallel with cell proliferation. In vascular smooth muscle cell (VSMC) cultures, ESDN expression was significantly higher in proliferating, as compared to growth-arrested cells. ESDN overexpression in VSMC led to a decline in growth curves, while ESDN knock down had the opposite effect. We conclude that ESDN is a marker of vascular remodeling and regulator of VSMC proliferation. ESDN may serve as a therapeutic or diagnostic target for GA.

Knowledge, attitudes and sources of information regarding HIV/AIDS in Iranian adolescents.

The World Health Organization recently reported an 'alarming trend' of increasing Human Deficiency Virus (HIV) infection in the Islamic Republic of Iran. Adolescents form a particularly important target group for primary prevention. An anonymous questionnaire, derived from standard surveys such as the Safer Choices questionnaire and the 2001 Youth Risk Behavior Survey, was distributed to 1227 Iranian students attending 19 randomly selected high schools in Hashtgerd in 2002. Students reported that television (84%) and school teachers (66%) were the best sources of HIV/AIDS information, while parents (27%) and school books (15%) were least informative. Most students knew that heterosexual intercourse (90%) and shared intravenous needles (94%) can cause HIV infection; however, salient misconceptions were revealed. Only 53% were aware that condoms protect against infection through sexual intercourse. More effective school-based HIV/AIDS education is needed in Iran.

Prevalence and distribution of peripheral nerve injuries in victims of Bam earthquake.

INTRODUCTION: In the early morning of Friday 25th Dec. 2003, the ancient and historical city of Bam in Southern East of Iran was vibrated by a big and horrible earthquake for 6.4 degree of Richter. About 30,000 people were died and about 30,000 victims and injured persons were the initial results of the earthquake. Almost all of the buildings were destroyed and all the people became houseless. In this study, 156 patients with peripheral nerve lesion (PNL) were assessed for their injuries. MATERIALS AND METHODS: In a cross sectional study since the second week after the quake until 6 months later, we examined 506 patients with the symptoms and signs of motor/sensory and performed the Electrodiagnostic study for all of the patients who had obvious or suspected lesion of peripheral nerves. There were 156 patients (31.2%) afflicted with peripheral nerve lesion. We performed NCS/EMG for upper limb and face at least 2 weeks and for lower limb, at least 3 weeks after injury in 156 of the victims that had PNL. FINDINGS: Of 156 patients, 75 (48%) were female and 81 (52%) were male. The average of age was 29.2 +/- 12.9 years, about 87.2% were between 15 to 50 yrs old. The frequency of injuries was 88 nerves, 53 neural plexuses and 5 cauda equina lesions. The most frequent injured nerve was sciatic nerve (24.8%) and the next was Radial nerve (15.5%) and the less frequent nerve was axillary which observed just in 1 patient. 21.6% of patients had the brachial plexus and/or lumbosacral plexus injuries. There were more involvements in lower limbs comparing upper limbs and face (p < 0.01). CONCLUSION: Peripheral nerve injury is one of the most frequent injuries in earthquake victims. These lesions may cause temporary or lifelong disabilities in patients. In this study, the more frequent involvement of sciatic and radial nerve seems to be related to their anatomic location and also the position of victims when earthquake happened and the involvement of brachial and lumbosacral plexus could be due to inappropriate evacuation of the victims from the loads and also due to incorrect transportation.

[The verification of the results of screening antibodies to hepatitis C virus in blood donors].

6,744 persons were examined for the presence of antibodies to hepatitis C virus (HCV) before blood donation (4,219 persons in Moscow and 2,525 persons in St. Petersburg). The serum samples found to contain antibodies to HCV were additionally studied by the immunoblot techniques. The positive results of antibody screening were registered in 78 persons: 26 persons in Moscow (0.62%) and 52 in St. Petersburg (2.05%). In both cities the positive results of screening were confirmed in 62% of cases. Different occurrence of the profile with the presence of antibodies to all fragments of the virus: 52% in Moscow, 12% in St. Petersburg (chi2 = 12.11; p < 0.001). Considerable differences were also registered in the spread of individual antibodies.