Seroepidemiology of Herpes Simplex Viruses Type 1 and 2 in Pregnant Women in Croatia

Background and Objectives: Herpes simplex viruses (HSV-1 and HSV-2) are one of the most widespread causes of human viral infections. In Croatia, only two published studies have analyzed the seroprevalence of HSV infections in childbearing-aged and pregnant women (2005-2010), while more recent data are lacking. This study aimed to analyze the prevalence and risk factors for HSV-1 and HSV-2 infections among pregnant women in Croatia in the period from 2011 to 2021. Materials and Methods: This study included 667 pregnant women aged 16-45 years submitted for HSV-1 and HSV-2 serology testing. Serum samples were initially screened for HSV-1 and HSV-2 IgM and IgG antibodies using a commercial ELISA test with a confirmation of HSV-2-positive samples using an immunoblot assay. Results: The overall IgG seroprevalence rates were 69.9% for HSV-1 and 3.8% for HSV-2. A significant gradual increase in the HSV-2 seroprevalence with age was observed from 0.5% in participants under 30 years to 8.3% in participants above 40 years. The HSV-1 seroprevalence was stable up to 40 years (70.0 and 68.3%, respectively), with an increase to 86.1%, but this difference did not reach statistical significance. Area of residence (urban or suburban/rural), geographic region (continental or coastal), and obstetric history (normal pregnancy or unfavorable obstetric history) were not associated with HSV-1 and HSV-2 seroprevalence. Older age was found to be a significant risk factor for HSV-2 seropositivity in both univariate and multivariate risk analysis. Conclusions: HSV-1 infection is widely prevalent among pregnant women with a stable trend over time. However, a declining trend in the HSV-2 seroprevalence was observed compared to 2005-2010. Serological screening in pregnant women is important in identifying seronegative women who are susceptible to HSV infection as well as seropositive women who are at risk for genital herpes recurrence during delivery.

Insights into hepatitis E virus epidemiology in Croatia

BACKGROUND

Hepatitis E virus (HEV) is an emerging virus of global health concern. The seroprevalence rates differ greatly according to geographic region and population group.

AIM

To analyze the seroprevalence of HEV in exposed (animal-related professions) and nonexposed populations, as well as solid organ and hematopoietic stem cell transplant patients.

METHODS

Forestry workers (n = 93), hunters (n = 74), and veterinarians (n = 151) represented the exposed population. The general population (n = 126) and pregnant women (n = 118) constituted the control group. Transplant patients included liver transplant recipients (LTRs) (n = 83), kidney transplant recipients (KTRs) (n = 43), and hematopoietic stem cell transplant recipients (HSCRs) (n = 39). HEV immunoglobulin G antibodies were detected using the enzyme-linked immunosorbent assay and confirmed by the immunoblot test.

RESULTS

The HEV seroprevalence significantly differed between groups: Veterinarians 15.2%, hunters 14.9%, forestry workers 6.5%, general population 7.1%, and pregnant women 1.7%. In transplant patients, the seropositivity was highest in LTRs (19.3%), while in KTRs and HSCRs, the seroprevalence was similar to the general population (6.9% and 5.1%, respectively). A significant increase in seropositivity with age was observed from 2.9% in individuals less than 30 years to 23.5% in those older than 60 years. Sociodemographic characteristics (sex, educational level, area of residence, and number of household members), eating habits (game meat, offal, and pork products consumption), and environmental and housing conditions (drinking water supply, type of water drainage/sewer, waste disposal, domestic animals) were not associated with HEV seropositivity. However, individuals who reported a pet ownership were more often seropositive compared to those who did not have pet animals (12.5% vs 7.0%).

CONCLUSION

The results of this study showed that individuals in professional contact with animals and LTRs are at higher risk for HEV infection. In addition, age is a significant risk factor for HEV seropositivity.

Revealing the Wonder of Natural Photonics by Nonlinear Optics

Nano-optics explores linear and nonlinear phenomena at the nanoscale to advance fundamental knowledge about materials and their interaction with light in the classical and quantum domains in order to develop new photonics-based technologies. In this perspective article, we review recent progress regarding the application of nonlinear optical methods to reveal the links between photonic structures and functions of natural photonic geometries. Furthermore, nonlinear optics offers a way to unveil and exploit the complexity of the natural world for developing new materials and technologies for the generation, detection, manipulation, and storage of light at the nanoscale, as well as sensing, metrology, and communication.

Parvovirus B19 in Croatia: A Large-Scale Seroprevalence Study

Background and Objectives: Seroepidemiological studies indicate that parvovirus B19 circulates in all areas of the world, although with some differences. The aim of this study is to analyze the seroprevalence of parvovirus B19 in the Croatian population. Materials and Methods: From 2010 to 2021, 1538 serum samples from different populations were tested for the presence of parvovirus B19 IgM/IgG antibodies. Serological tests were performed using a commercial enzyme-linked immunosorbent assay. Results: IgG antibodies were detected in 986/64.1% of participants with differences (p < 0.001) among the following population groups: 42.4% of children and adolescents, 67.1% of the adult general population, 66.7% of hemodialysis patients, and 65.6% of liver transplant recipients. Seroprevalence increased with age, from 30.0% in the 6 months-9 years age group to 69.0% in the 40-49 years age group, and remained stable thereafter (68.8-73.3%). There was no difference in the seropositivity among males (66.1%) and females (63.1%), as well as the place of residence (suburban/rural 63.9%, urban 64.1%). IgM antibodies (current/recent infection) were found in 61/4.0% of participants with the highest seropositivity in the youngest age group (11.1%). In pregnant women, seroprevalence was higher in women with an unfavorable obstetric history compared with a normal pregnancy (IgG 71.0% vs. 62.6%; IgM 6.5% vs. 2.4%), but these differences were not significant. Logistic regression showed that the adult population had almost three times higher risk of IgG seropositivity compared to children/adolescents (general population OR = 2.777, 95% CI = 2.023-3.812; hemodialysis patients OR = 2.586, 95% CI = 1.531-4.367; and transplant patients OR = 2.717, 95% CI = 1.604-4.603). A one-year increase in age increased the risk of IgG seroprevalence (OR = 1.017; 95% CI = 1.011-1.022). Conclusions: Older age was the main risk factor for IgG seropositivity. Hemodialysis and organ transplantation seem unrelated to the increased parvovirus B19 seroprevalence. The role of parvovirus B19 in the etiology of TORCH infections needs to be studied further.

Seroepidemiology of hepatitis E in patients on haemodialysis in Croatia

PURPOSE

Data on the seroprevalence of hepatitis E virus (HEV) in heamodialysis (HD) patients are conflicting, ranging from 0 to 44%. The aim of this study was to determine the HEV seroprevalence and risk factors among HD patients in Croatia.

METHODS

A total of 394 HD patients from six medical facilities in five Croatian cities (three sites in the continental and three sites in the coastal region) were tested for HEV IgM/IgG antibodies using an enzyme-linked immunosorbent assay. Additionally, all samples were tested for HEV RNA by RT-PCR. Sociodemographic data and risk factors were collected using a questionnaire.

RESULTS

HEV IgG antibodies were detected in 110 (27.9%) patients. The seroprevalence varied significantly between dialysis centres, ranging from 5.2 to 43.4% (p = 0.001). HEV IgM antibodies were found in 0.04% of IgG positive patients. All patients tested negative for HEV RNA. Factors associated with HEV IgG seropositivity were age > 60 years (OR 8.17; 95% CI 1.08-62.14), living in the continental parts of the country (OR 2.58; 95% CI 1.55-4.30), and transfusion of blood products (OR 1.66; 95% CI 1.01-2.73). After adjusting for age and gender, patients from continental regions had higher odds of HEV seropositivity compared to patients from coastal regions (OR 2.88; 95% CI 1.71-4.85) and those who had RBC transfusions (OR 1.70, 95% CI 1.02-2.69) compared to those who did not.

CONCLUSION

The study showed a high HEV seropositivity among HD patients in Croatia, with significant variations between geographical regions. Continental area of residence and RBC transfusion were the most significant risk factors for HEV seropositivity. Due to the high seroprevalence, routine HEV screening among HD patients, especially in transplant candidates should be considered.

Unveiling the nonlinear optical response of Trictenotoma childreni longhorn beetle

The wings of some insect species are known to fluoresce under illumination by ultraviolet light. Their fluorescence properties are however, not comprehensively documented. In this article, the optical properties of one specific insect, the Trictenotoma childreni yellow longhorn beetle, were investigated using both linear and nonlinear optical (NLO) methods, including one- and two-photon fluorescence and second harmonic generation (SHG). These three distinct optical signals discovered in this beetle are attributed to the presence of fluorophores embedded within the scales covering their elytra. Experimental evidence collected in this study indicates that the fluorophores are non-centrosymmetric, a fundamental requirement for SHG. This study is the first reported optical behavior of this type in insects. We described how NLO techniques can complement other more convenient approaches to achieve a more comprehensive understanding of insect scales and integument properties.

Influence of Gerontology Services on the Physical and Psychological Health of Elderly in the City of Zagreb

BACKGROUND

The World Health Organization (WHO) defines the quality of life as an individual perception of personal position in the cultural and social system within an individual's environment. Elderly people, in general, prefer to live in their own home as much as possible, and moving means for them losing social relationships, changing routines and lifestyles and losing independence. The research aimed to gain insight into the use of gerontology services for the elderly people, their availability, diversity of information, a range of services they provide, and impact of these services on quality of life.

SUBJECTS AND METHODS

The study population is defined as persons residing in Zagreb, 65 years of age or older, with no physical disability or severe bodily, cognitive or mental illnesses who are users of the gerontology center. The survey was conducted using a customized questionnaire survey on a total sample of 103 respondents.

RESULTS

The most significant number of respondents, since they use the facilities, feel satisfied (68%) and very satisfied (28.2%) in their life. More than half of the participants (52.4%) rated their quality of life as very good and excellent, 46.6% of respondents rated their quality of life as good. Issues that effect on quality of life point to the dissatisfaction of the respondents are their financial resources, inadequate health services, and the lack of a positive social network.

CONCLUSIONS

Community services, such as gerontology centers, enable social network development, new learning, physical activity, which have an impact on physical and psychological health and thus on the quality of life of elderly people. The satisfaction of the respondents using these services was rated above the average (3.71), which indicates that the society is moving in the right direction, encouraging this form of care for the elderly.

Nonlinear optical spectroscopy and two-photon excited fluorescence spectroscopy reveal the excited states of fluorophores embedded in a beetle's elytra

Upon illumination by ultraviolet light, many animal species emit light through fluorescence processes arising from fluorophores embedded within their biological tissues. Fluorescence studies in living organisms are however relatively scarce and so far limited to the linear regime. Multiphoton excitation fluorescence analyses as well as nonlinear optical techniques offer unique possibilities to investigate the effects of the local environment on the excited states of fluorophores. Herein, these techniques are applied for the first time to study of the naturally controlled fluorescence in insects. The case of the male Hoplia coerulea beetle is investigated because the scales covering the beetle's elytra are known to possess an internal photonic structure with embedded fluorophores, which controls both the beetle's coloration and the fluorescence emission. An intense two-photon excitation fluorescence signal is observed, the intensity of which changes upon contact with water. A third-harmonic generation signal is also detected, the intensity of which depends on the light polarization state. The analysis of these nonlinear optical and fluorescent responses unveils the multi-excited states character of the fluorophore molecules embedded in the beetle's elytra. The role of form anisotropy in the photonic structure, which causes additional tailoring of the beetle's optical responses, is demonstrated by circularly polarized light and nonlinear optical measurements.

Hepatitis E seroprevalence and associated risk factors in Croatian liver transplant recipients

INTRODUCTION

Solid-organ transplant recipients are at risk of hepatitis E virus (HEV) infection. We analyzed the seroprevalence/risk factors of HEV in Croatian liver transplant recipients.

METHODS

Two hundred forty-two serum samples were tested for HEV immunoglobuline IgG/IgM and HEV RNA. Sociodemographic data and risk factors were collected using a questionnaire.

RESULTS

HEV IgG seroprevalence rate was 24.4%. Positive/equivocal HEV IgM were found in two patients. HEV RNA was not detected. Logistic regression showed that older age, female gender, rural area/farm, water well, and septic tank were associated with HEV seropositivity.

CONCLUSIONS

This study revealed a high exposure rate to HEV in Croatian liver recipients.

Linear and nonlinear optical effects in biophotonic structures using classical and nonclassical light

In this perspective article, we review the optical study of different biophotonic geometries and biological structures using classical light in linear and nonlinear regime, especially highlighting the link between these morphologies and modern biomedical research. Additionally, the importance of nonlinear optical study in biological research, beyond traditional cell imaging is also highlighted and described. Finally, we present a short introduction regarding nonclassical light and describe the new future perspective of quantum optical study in biology, revealing the link between quantum realm and biological research.

Diagnostic significance of immunoglobulin G avidity in symptomatic and asymptomatic West Nile virus infection

INTRODUCTION

West Nile virus (WNV) immunoglobulin M (IgM) antibodies have been shown to persist for up to 500 days in certain patients. To evaluate the usefulness of immunoglobulin G (IgG) avidity assessment in the diagnosis of WNV infection, we analyzed 54 WNV IgM- and/or IgG-positive serum samples from 39 patients with neuroinvasive disease and 15 asymptomatic cases tested during a seroprevalence investigation.

METHODS

Serological tests (WNV IgM/IgG antibody detection, IgG avidity) were performed using commercially available enzyme-linked immunosorbent assays.

RESULTS

WNV IgM antibodies were detected in 47 (87%) samples. Acute/recent WNV infection was confirmed based on low/borderline avidity index (AI) in 44 IgM-positive samples (93.6%). In three IgM-positive samples (6.4%), high IgG AIs were detected, thus indicating persisting IgM antibodies from previous infections. All IgM-negative samples showed high AIs. Patients with WNV neuroinvasive disease tested within 30 days showed low AIs. In six patients tested 34-50 days after disease onset, AI was borderline (42%-60%), suggesting earlier WNV IgG maturation. Samples with the highest IgM values were associated with the lowest AIs (Spearman's rho coefficient -0.767, p < 0.001).

CONCLUSIONS

Our results indicate that IgG avidity differentiates current/recent WNV infection from persistent IgM seropositivity from the previous WNV transmission season both in patients with WNV neuroinvasive disease and in asymptomatic persons. A strong negative correlation between IgM antibody levels and AI indicates that in cases with very high IgM levels, determination of IgG avidity may not be necessary. As many patients showed rapid avidity maturation, low IgG avidity is indicative of WNV infection within the previous month.

Controlled fluorescence in a beetle's photonic structure and its sensitivity to environmentally induced changes

The scales covering the elytra of the male Hoplia coerulea beetle contain fluorophores embedded within a porous photonic structure. The photonic structure controls both insect colour (reflected light) and fluorescence emission. Herein, the effects of water-induced changes on the fluorescence emission from the beetle were investigated. The fluorescence emission peak wavelength was observed to blue-shift on water immersion of the elytra whereas its reflectance peak wavelength was observed to red-shift. Time-resolved fluorescence measurements, together with optical simulations, confirmed that the radiative emission is controlled by a naturally engineered photonic bandgap while the elytra are in the dry state, whereas non-radiative relaxation pathways dominate the emission response of wet elytra.

Seroepidemiology of cytomegalovirus infections in Croatia

BACKGROUND

Cytomegalovirus (CMV) is endemic worldwide, with marked differences in the seroprevalence rates between countries. The aim of this study was to analyze the seroprevalence of CMV infections in Croatia.

METHODS

During a 3-year period (2013-2015) 2438 consecutive serum samples collected from Croatian residents were tested for the presence of CMV IgM and IgG antibodies using enzyme-linked immunoassay. The IgM/IgG positive samples were further tested for IgG avidity.

RESULTS

The overall seroprevalence rates for CMV IgG and IgM antibodies were 74.4 % and 4.3 %, respectively. The IgG seroprevalence showed significant differences between population groups: children/adolescents 54.6 %, general adult population 77.2 %, hemodialysis patients 91.4 % (p < 0.001). Seropositivity of CMV was strongly age-dependent with prevalences ranging from 53.0 % in children less than 10 years old to 93.8 % in persons above 60 years (p < 0.001). There was no difference in the prevalence rate between women with normal pregnancy and women with poor obstetric history. Gender and place of residence were not associated with CMV seropositivity. Using IgG avidity, current/recent primary CMV infection was confirmed by a low/borderline avidity index (AI) in 46.7 % participants, while in 53.3 % a high AI indicated CMV reactivation or reinfection. Primary infections were detected mainly in children and adolescents (83.2 % and 70.5 %, respectively), while reactivation/reinfection was common in persons older than 40 (77.0-100 %). Reactivation/reinfection was most commonly detected in hemodialysis patients (92.3 %). Logistic regression showed that older age and being on hemodialysis were significant predictors of CMV seropositivity.

CONCLUSION

Infections with CMV are widespread in the Croatian population. Older age and being on hemodialysis appear to be the main risk factors for CMV infection.

Seroepidemiology of Hepatitis E in Selected Population Groups in Croatia: A Prospective Pilot Study

Hepatitis E has become an emerging infection in many European countries. We analysed the prevalence of hepatitis E virus (HEV) infection in selected population groups in Croatia. Overall HEV IgG seropositivity was 5.6%, while 1.9% participants showed IgM antibodies suggestive of recent infection. No IgM-positive sample was positive for HEV RNA. HEV IgG antibodies were most prevalent in alcohol abusers (8.9%) and war veterans (8.6%), compared with 6.1% among injecting drug users and 2.7% in healthcare professionals. No individual with high-risk sexual behaviour tested HEV seropositive. HEV IgG positivity increased significantly with age from 1.8% to 2.3% in individuals younger than 40 years to 11.3% in individuals older than 50 years (P = 0.023). The mean age of HEV-positive participants was significantly higher than that of HEV-negative participants (50.9 ± 11.8 years versus 41.2 ± 11.8 years, P = 0.008). Seroprevalence rates were significantly higher in residents of suburban and rural areas compared with residents of urban areas (14.5% versus 2.5%, P = 0.003). Additionally, an increasing prevalence of HEV IgG antibodies was observed from 1.8% in participants living in families with two household members to 12.1% in those living with more than four members (P = 0.046). Gender, marital status, educational level, sexual orientation, source of drinking water, history of blood transfusions, surgical procedures, tattooing and travelling were not associated with HEV seroprevalence. Logistic regression showed that living in suburban/rural areas was the main risk factor for HEV seropositivity (OR = 6.67; 95%CI = 1.89-25.0; AOR = 7.14, 95%CI = 1.89-25.0).

Prevalence and dynamics of cytomegalovirus infection among patients undergoing chronic hemodialysis

Cytomegalovirus (CMV) is an important pathogen in immunocompromised individuals. The aim of this study was to analyze prevalence and dynamics of CMV infection among patients undergoing chronic hemodialysis. From 2010 to 2012, a total of 162 patients and 160 control subjects were tested for the presence of CMV IgM and IgG antibodies using enzyme-linked immunosorbent assay. IgM/IgG reactive samples were further evaluated for IgG avidity to confirm or rule out recent primary CMV infection. The overall IgG seropositivity was higher in hemodialysis patients compared to controls (90.7% vs. 81.9%; crude odds ratio [OR] =2.02, 95% confidence interval [CI] =1.05–3.89; OR adjusted for age and gender = 2.18, 95% CI = 1.05–4.55). CMV IgG antibody titers were similar in both groups. There was no difference in CMV prevalence between males (87.9%) and females (96.3%). According to age, a progressive increase in seropositivity was observed in both hemodialysis patients and the control group. Three hemodialysis patients (1.9%) developed recurrent CMV infection (positive IgM with high avidity IgG antibodies). In one patient (2.9%), seroconversion was documented during the second year of the follow-up period indicating primary infection. In contrast, in the control group, recent primary CMV infection (positive IgM with low/borderline IgG avidity) was demonstrated in three subjects (1.9%), whereas one (0.6%) developed recurrent infection. On multivariate logistic regression, hemodialysis and older age were significant predictors for CMV seropositivity.

Stress, depression and burnout among hospital physicians in Rijeka, Croatia

BACKGROUND

Six years of recent ongoing economic and structural crisis in Croatia have brought to a significant decrease of socioeconomic standard in our country, and had an important impact on the health care system. In this background we examined the prevalence of depression and burnout and their association with work stressors.

SUBJECTS AND METHODS

Cross sectional survey was conducted with self reported questionnaires in 459 hospital physicians in Rijeka, Croatia. Physicians were divided into three groups: surgical, nonsurgical and diagnostic group. Socio-demographic and work-related characteristics questionnaire, Occupational Stress Assessment Questionnaire (OSAQ), Maslach Burnout Inventory-Human Services Survey (MBI-HSS) and Beck Depression Inventory II (BDI-II) were used. Sperman correlation and logistic regression were calculated to rank association between stressors at work with depression and burnout syndrome.

RESULTS

Response rate was 62.3%, (286/459). Every fifth doctor experienced all examined stressors in the workplace as stressful. The prevalence of moderate and severe depression was 12.2%. High levels of emotional exhaustion were 43.6%, depersonalization 33.5%, and lack of personal accomplishment 49.1%. There was no statistical difference in surgical, nonsurgical and diagnostic groups in depression and all domains of MBI-HSS. Almost all stressors were correlated with depression and burnout syndrome. Most of the perceived stressors were significant predictors of burnout syndrome and depression.

CONCLUSIONS

High levels of burnout domain compared to overall results from similar studies from other countries, placed the results in our sample on the higher end of the range, while results for depression after adjustment with lower cutoff point would be similar to those usually found in research literature. Our study showed that burnout is highly prevalent among Croatian physicians. Target interventions at the workplace should be considered as one of the strategies to reduce negative impact of work stress on physicians' mental health.

Drug-eluting balloons in patients with non-ST elevation acute coronary syndrome

BACKGROUND

We compared efficacy of bare-metal stent (BMS) and drug-eluting balloon (DEB) combination vs BMS alone, in patients with non-ST elevation acute coronary syndrome treated with percutaneous coronary intervention (PCI).

METHODS

Patients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina (UA) were randomized to BMS only or BMS+DEB group. Angiographic follow-up was performed after 6 months. The primary endpoints were binary in-stent restenosis (ISR) and late lumen loss (LLL) and the secondary endpoints were target lesion revascularization (TLR), stent thrombosis (ST), and new acute coronary syndrome (ACS).

RESULTS

A total of 85 patients were enrolled, 44 (BMS) and 41 (BMS+DEB). The median age was 67 (36-84) years and 68 (80%) were male. Fifty-two patients (61.2%) had NSTEMI and 33 patients (38.8%) UA. There was no difference in patient demographics, risk factors, and clinical characteristics, except for more smokers in the BMS+DEB group 18/41 (43.9%) vs 9/44 (20.5%). At follow-up, no significant difference in binary ISR was found; p=0.593, but LLL was significantly lower in the BMS+DEB group 0.68 (0.00-2.15) mm vs 0.22 (0.00-2.35) mm; p=0.002. The difference in major adverse cardiac events (MACE) rate combining TLR, ST, and ACS, between the groups was also non-significant, 29.5% (BMS) vs 24.4% (BMS+DEB); p=0.835. One patient had a subacute ST (BMS+DEB) due to clopidogrel resistance.

CONCLUSION

Patients treated with BMS+DEB combination for non-ST elevation acute coronary syndrome had significantly less LLL in comparison to patients treated with BMS alone but without an impact on patient clinical outcomes.

Lower levels of total HDL and HDL3 cholesterol are associated with albuminuria in normoalbuminuric Type 1 diabetic patients

BACKGROUND

Previous studies have suggested a positive association between dyslipidemia and chronic kidney disease, but sparse data are available on the relation of lipids and urinary albumin excretion rate (UAE) in normoalbuminuric patients with normal renal function.

AIM

The aim of this study was to evaluate the associations of serum lipids, including total, LDL, HDL, HDL2, HDL3 cholesterol, and triglyceride levels with UAE in normoalbuminuric Type 1 diabetic (T1D) patients.

METHODS

Study included 313 normoalbuminuric T1D patients with normal renal function and before any interventions with statins, ACE inhibitors or angiotensin II receptor blockers. Subjects were classified as low-normoalbuminuric (UAE<11.0 mg/24h) or high-normoalbuminuric (UAE≥11.0 mg/24h) based on median UAE of at least two 24- h urine collections. Correlations and multiple linear regressions analysis were performed to identify relationships between serum lipids and UAE in normoalbuminuric subjects.

RESULTS

Total HDL (p=0.02) and HDL3 cholesterol (p=0.01) levels were higher in low-normoalbuminuric subjects compared to high-normoalbuminuric subjects. In logistic regression analysis, after adjustment for age, sex, BMI, duration of diabetes and HbA1c, lower total HDL and HDL3 cholesterol levels were significantly associated with risk of higher UAE in our normoalbuminuric subjects (p≤0.01), with odds ratios of 0.34 to 0.43.

CONCLUSIONS

Elevated total HDL and HDL3 cholesterol levels are associated with lower UAE in normoalbuminuric T1D patients. However, whether the detection of elevated total HDL and HDL3 cholesterol levels in T1D patients has protective value for development of microalbuminuria needs to be assessed in further follow-up studies.

Mammographic density and estimation of breast cancer risk in intermediate risk population

It is not clear to what extent mammographic density represents a risk factor for breast cancer among women with moderate risk for disease. We conducted a population-based study to estimate the independent effect of breast density on breast cancer risk and to evaluate the potential of breast density as a marker of risk in an intermediate risk population. From November 2006 to April 2009, data that included American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) breast density categories and risk information were collected on 52,752 women aged 50-69 years without previously diagnosed breast cancer who underwent screening mammography examination. A total of 257 screen-detected breast cancers were identified. Logistic regression was used to assess the effect of breast density on breast carcinoma risk and to control for other risk factors. The risk increased with density and the odds ratio for breast cancer among women with dense breast (heterogeneously and extremely dense breast), was 1.9 (95% confidence interval, 1.3-2.8) compared with women with almost entirely fat breasts, after adjustment for age, body mass index, age at menarche, age at menopause, age at first childbirth, number of live births, use of oral contraceptive, family history of breast cancer, prior breast procedures, and hormone replacement therapy use that were all significantly related to breast density (p < 0.001). In multivariate model, breast cancer risk increased with age, body mass index, family history of breast cancer, prior breast procedure and breast density and decreased with number of live births. Our finding that mammographic density is an independent risk factor for breast cancer indicates the importance of breast density measurements for breast cancer risk assessment also in moderate risk populations.

Prevalence of Coxiella burnetii antibodies among febrile patients in Croatia, 2008-2010

Despite the widespread distribution of Q fever, the prevalence in humans is not accurately known, because many infected people seroconvert without symptoms or with a mild febrile disease. The aim of this study was to determine the seroprevalence of Q fever in different regions of Croatia. During a 2-year period (2008-2010), serum samples from 552 febrile patients with prolonged cough aged 1-88 were tested for the presence of Coxiella burnetii antibodies by using indirect immunofluorescent assay. Sera from 27.5% patients showed IgG antibodies. Serological evidence of C. burnetii infection was found in patients from all parts of Croatia. Seroprevalence rates significantly differed among regions from 21.5% to 41.2% (p=0.001). Men were more often seropositive (31.6%) than women (22.2%; p=0.016). According to age, a progressive increase in the IgG seropositivity rates was observed as ranging from 6.7% in children less than 10 years of age to 39.2% in patients aged 40-49 (p=0.001). Above the age of 50, the IgG seroprevalence remained stable. Patients from rural areas were more often seropositive than patients from urban areas (40.8% vs. 19%), p<0.001). Acute Q fever was confirmed in 5.8% of patients. Cases occurred throughout the year. A majority of cases were reported during summer months.

Seroepidemiology of hepatitis a in the croatian population

BACKGROUND

Hepatitis A virus (HAV) has a worldwide distribution, although this distribution tends to be uneven among geographical regions and population groups. The prevalence of anti-HAV antibodies in the general population varies widely among countries. In Europe, the seroprevalence of HAV is reported to range from 32% to 88%.

OBJECTIVES

The aim of this study was to determine the seroprevalence of HAV among the general Croatian population.

MATERIALS AND METHODS

During a 2-year period (2008-2009), a total of 791 serum samples were tested for the presence of anti-HAV total (IgM+IgG) and anti-HAV IgM antibodies using an automated enzyme-linked fluorescent assay (Mini Vidas; bioMérieux, Marcy l'Etoile, France).

RESULTS

The overall anti-HAV seroprevalence was 41.6%. The observed difference in the seroprevalence rates among male and female patients was not statistically significant (44% vs. 39.6%, P = 0.218). A marked increase in anti-HAV seropositivity with age was observed (P < 0.001). The seroprevalence did not differ significantly between participants residing in rural regions (45.3%) and those residing in urban regions (40.6%, P = 0.292).

CONCLUSIONS

Our results corroborate those of seroprevalence studies in other developed countries. More than half of the Croatian population (59.4%) is susceptible to HAV infection. Older age is an important predictor for being anti-HAV positive.

Herpes simplex virus infection in the Croatian population

BACKGROUND

Herpes simplex virus (HSV) infections are caused by 2 types of virus, HSV-1 and HSV-2. Both viruses are endemic worldwide. There are marked variations in the seroprevalences of HSV-1 and HSV-2 in Europe. The aim of this study was to determine the seroprevalence of HSV infections in Croatia.

METHODS

During a 3-y period (2008-2010), a total of 1672 patients were tested for the presence of HSV-1 and HSV-2 antibodies using an enzyme-linked immunosorbent assay.

RESULTS

The overall immunoglobulin G (IgG) seroprevalence rates were 72.5% for HSV-1 and 9.9% for HSV-2. There was no significant difference in seropositivity between males and females for HSV-1 (72.0% vs 73.0%) or HSV-2 (8.9% vs 10.7%). HSV-1 seroprevalence increased from 26.4% in those aged 6 months-9 y to 89.9% in those aged 40?49 y, and remained stable thereafter, ranging from 87.4% to 91.5% (p < 0.001). HSV-2 IgG seropositivity increased progressively from 5.7% in participants aged 20-29 y to 26.5% in participants aged ≥ 60 y (p < 0.001). HSV-1 seroprevalence did not differ between participants residing in urban and rural areas (72.5% vs 72.6%). Urban place of residence was a significant factor for HSV-2 seroprevalence in univariate analysis, but after standardization for age, it was no longer significant.

CONCLUSIONS

Multiple logistic regression showed that age was a significant predictor of both HSV-1 and HSV-2 seropositivity, while female gender was a significant predictor of HSV-2 seropositivity. In pregnant women, obstetric history was not a significant predictor of either HSV-1 or HSV-2 seroprevalence.

Preoperative staging of renal cell carcinoma using magnetic resonance imaging: comparison with pathological staging

We have retrospectively assessed the accuracy of our MRI protocol on 1.0-T MRI system for preoperative staging of renal cell carcinoma using the 2002 TNM staging system and pathological staging as the gold standard. Medical records of 48 patients (mean age, 56.28 years) with 57 renal tumors were reviewed: 52 malignant renal tumors were found; most of the patients were staged T1N0M0. In our study, κ test revealed excellent agreement between all three classes of the TNM staging system.

Seroprevalence of TORCH infections in women of childbearing age in Croatia

During 2005-2009, a seroepidemiological study was carried out in Croatia to define the population susceptible to common TORCH agents among pregnant and non-pregnant women of childbearing age. The IgG seroprevalence was 29.1% forT. gondii, 94.6% for rubella, 75.3% for cytomegalovirus (CMV), 78.7% for herpes simplex virus type 1 (HSV-1), and 6.8% for HSV-2. Acute toxoplasmosis and CMV infection (positive IgM antibodies with low IgG avidity) were documented in 0.25% and 0.09% women, respectively. IgM prevalence was 1.2% for both HSV-1 and HSV-2. None of the participants showed acute rubella infection. Seropositivity to T. gondii and HSV-2 varied significantly between age groups (p = 0.001 and p = 0.036, respectively). Women residing in rural regions showed a significantly higher seroprevalence rate for T. gondii, CMV, and HSV-1 than urban women (T. gondii: 44.0% vs. 25.4%, p < 0.001; CMV: 85.0% vs. 73.1%, p = 0.018; HSV-1: 86.0% vs. 76.4%, p = 0.041).

Seroprevalence, risk factors, and hepatitis C virus genotypes in groups with high-risk sexual behavior in Croatia

The seroprevalence, risk factors and genotypes of hepatitis C virus (HCV) in groups with high-risk sexual behavior (persons with multiple sexual partners, men who have sex with men, commercial sex workers and their clients and persons with sexually transmitted diseases) in seven Croatian cities were analyzed. A total of 821 participants without history of injecting drug use were included in the study. Anti-HCV prevalence among risk groups varied from 2.9% to 8.5% with an overall prevalence of 4.6% (95% CI = 3.2-6.1) compared with 0.5% (95% CI = 0.0-1.5) in controls (pregnant females; OR = 9.66; 95% CI = 1.32-70.7). HCV-RNA was detected in 73.1% anti-HCV positive patients. Three of the seronegative cases (2.1%) were also found to be HCV-RNA positive ("window period"). Genotype 1 was most commonly detected (55.6%). The most prevalent subtypes were 1a (38.9%) and 3a (38.9%). Sociodemographic characteristics (age, gender, marital status and level of education) were not associated with anti-HCV seropositivity. Among sexually transmitted disease markers, a higher seroprevalence of HCV infection was found in subjects with a history of HBV infection (10.5% vs. 3.8%, P = 0.002) and gonorrhea (13.2% vs. 4.2%, P = 0.011). No other factors reflecting risk sexual behavior such as sexual orientation, number of sexual partners and number of risk behaviors were associated with HCV seroprevalence.

Controlling the photoluminescence of CdSe/ZnS quantum dots with a magnetic field

We present an investigation of the photoluminescence of CdSe/ZnS quantum dots at high light intensity and in low magnetic fields. Upon increasing the magnetic field up to 90 G, the photoluminescence intensity drops. When decreasing the magnetic field back to zero the photoluminescence drop remains present. A plausible explanation is the Zeeman splitting of defect-associated energy levels under the influence of a magnetic field. The defect-trapped electrons may then be positioned at a metastable level, thereby reducing the number of recombinations. This effect may be used to control the luminescence of quantum dots.

Single molecule fluorescence spectroscopy of pH sensitive oligonucleotide switches

Several authors demonstrated that an oligonucleotide based pH-sensitive construct can act as a switch between an open and a closed state by changing the pH. To validate this process, specially designed fluorescence dye-quencher substituted oligonucleotide constructs were developed to probe the switching between these two states. This paper reports on bulk and single molecule fluorescence investigations of a duplex-triplex pH sensitive oligonucleotide switch. On the bulk level, only a partial quenching of the fluorescence is observed, similarly to what is observed for other published switches and is supposed to be due to intermolecular interactions between oligonucleotide strands. On the single molecule level, each DNA-based nanometric construct shows a complete switching. These observations suggest the tendency of the DNA construct to associate at high concentration.

Biochemical indication for myristoylation-dependent conformational changes in HIV-1 Nef

The accessory HIV-1 Nef protein is essential for viral replication, high virus load, and progression to AIDS. These functions are mediated by the alteration of signaling and trafficking pathways and require the membrane association of Nef by its N-terminal myristoylation. However, a large portion of Nef is also found in the cytosol, in line with the observation that myristoylation is only a weak lipidation anchor for membrane attachment. We performed biochemical studies to analyze the implications of myristoylation on the conformation of Nef in aqueous solution. To establish an in vivo myristoylation assay, we first optimized the codon usage of Nef for Escherichia coli expression, which resulted in a 15-fold higher protein yield. Myristoylation was achieved by coexpression with the N-myristoyltransferase and confirmed by mass spectrometry. The myristoylated protein was soluble, and proton NMR spectra confirmed proper folding. Size exclusion chromatography revealed that myristoylated Nef appeared of smaller size than the unmodified form but not as small as an N-terminally truncated from of Nef that omits the anchor domain. Western blot stainings and limited proteolysis of both forms showed different recognition profiles and degradation pattern. Analytical ultracentrifugation revealed that myristoylated Nef prevails in a monomeric state while the unmodified form exists in an oligomeric equilibrium of monomer, dimer, and trimer associations. Finally, fluorescence correlation spectroscopy using multiphoton excitation revealed a shorter diffusion time for the lipidated protein compared to the unmodified form. Taken together, our data indicated myristoylation-dependent conformational changes in Nef, suggesting a rather compact and monomeric form for the lipidated protein in solution.

Cardiovascular diseases in Croatia and other transitional countries: comparative study of publications, clinical interventions, and burden of disease

AIM

To determine the number of publications on cardiovascular diseases in the MEDLINE database, the rate of medical doctors and clinical interventions in cardiology, and health and socioeconomic indicators for Croatia, and to compare them with those for Slovenia, Hungary, the Czech Republic, and Austria.

METHODS

PubMed was used in search for publications on cardiovascular diseases published in 1991-2004. Rates per million population and proportions of publications on cardiovascular diseases in the MEDLINE database were calculated. Gross domestic product (GDP) per capita was used as a socioeconomic indicator, whereas human resources in medicine were presented as the rate of medical doctors per million population. Standardized death rates from cardiovascular diseases and ischemic heart disease were used as indicators of cardiovascular health. Clinical interventions in cardiology, such as coronary angiograms, percutaneous transluminal coronary angioplasties (PTCA), and coronary bypass surgeries (CABG) were expressed per million population per year.

RESULTS

Croatia had the lowest GDP per capita among the analyzed countries. The standardized death rate from cardiovascular diseases in Croatia was 91.7 per 100,000 population aged 0-64 in 2001, which was higher than that in Slovenia and Austria (P<0.001), similar to that in the Czech Republic, and lower than that in Hungary (P<0.001). Cardiovascular scientific output in Croatia was the lowest among investigated countries, ie, 1.1 per million population in 2003 (P<0.001). Despite a significantly lower number of medical doctors in comparison with Hungary and the Czech Republic (P<0.001), Croatia experienced a similar increment in the amount of clinical interventions in cardiology.

CONCLUSION

In contrast to high cardiovascular mortality rates, cardiovascular scientific production in Croatia was significantly lower than in other investigated countries. A positive trend in cardiovascular medicine was recorded in clinical practice, but has yet to be followed by scientific production.

Sex ratio at birth and war in Croatia (1991–1995)

BACKGROUND

We have investigated sex ratio at birth (expressed as the proportion of males) in Croatia before, during and after the war (1991-1995).

METHODS

Data for each of 21 counties in Croatia (861 516 births) were collected and pooled into two groups: the first, consisting of the counties unaffected by the war, and the second, comprising the counties affected by war events. Odds ratios of being born as a male were calculated, with being born in a county exposed to war defined as the risk factor.

RESULTS

No significant deviations from the expected ratio of 0.514 were found in pre-war, wartime or post-war period at the national level. The ratio was 0.515 during the pre-war and wartime periods, and 0.514 in the post-war period. Comparison of the ratios in the three periods in both affected and unaffected counties revealed no significant increase in the sex ratio. The only significant increase in the sex ratio was registered in two counties unaffected by the warfare.

CONCLUSIONS

This study indicates that warfare did not cause a detectable increase of the sex ratio at birth in Croatia, in contrast to what might have been predicted based on earlier reports in the literature.

Foam films stabilized by dodecyl maltoside. 1. Film thickness and free energy of film formation

Foam films stabilized by a sugar-based nonionic surfactant, beta-dodecyl maltoside, are investigated. The film thickness and the film contact angle (which is formed at the transition between the film and the bulk solution) are measured as a function of NaCl concentration, surfactant concentration, and temperature. The film thickness measurements provide information about the balance of the surface forces in the film whereas the contact angle measurements provide information about the specific film interaction free energy. The use of the glass ring cell and the thin film pressure balance methods enables studies under a large variety of conditions. Thick foam films are formed at low electrolyte concentration. The film thickness decreases (respectively the absolute value of the interaction film free energy increases) with the increase of the electrolyte concentration according to the classical DLVO theory. This indicates the existence of a repulsive double layer electrostatic component of the disjoining pressure. An electrostatic double layer potential of 16 mV was calculated from the data. A decrease of the film thickness on increase of the surfactant concentration in the solution is observed. The results are interpreted on the basis of the assumption that the surface double layer potential originates in the adsorption of hydroxyl ions at the film surfaces. These ions are expelled from the surface at higher surfactant concentration.

Entanglement of protons in organic molecules: an attosecond neutron scattering study of C [bond] H bond breaking

Interactions between adjacent particles of condensed phases can lead to quantum correlation phenomena, like quantum interference, entanglement, delocalization, and "Schrödinger's cat" states. Such correlations are theoretically expected to be extremely short-lived because of environmental disturbances. Here, we present experimental evidence for quantum entanglement between well localized protons of C [bond] H bonds of 2-isobutoxyethanol dissolved in D(2)O. The applied experimental method is neutron Compton scattering (NCS), which has a characteristic time window in the subfemtosecond time range. Our NCS results reveal that, in the subfemtosecond time scale, the measured cross-section density, and thus, in simple terms, the effectively present concentration, of the H atoms is "anomalously" reduced by approximately 20%. Affecting the microdynamics of protons of covalent C [bond] H bonds, this novel effect may have a broad range of chemical and biological applications.