Sleep quality in the Croatian adult population during the COVID-19 pandemic

Background

The COVID-19 pandemic as a worldwide public health issue is a traumatic event that has affected both the sleep and mental health of the general population. This study aimed to evaluate the quality of sleep in the Croatian adult population during the COVID-19 pandemic.

Methods

This cross-sectional questionnaire study was conducted from February to June 2021 period. A validated, anonymous questionnaire that contained questions regarding demographic data, as well as Pittsburgh Sleep Quality Index (PSQI) and Coronavirus Anxiety Scale (CAS) was self-administered to a convenient sample of Croatian adults from central and northwestern Croatia.

Results

The study sample included 939 subjects with, median age of 42 years (interquartile range 35-48), 35.4% males, and 64.6% females. At the PSQI 22.6% of subjects presented sleep disturbances while at the CAS 0.4% of subjects presented dysfunctional anxiety associated with the COVID-19 pandemic. Sleep disturbances were more frequent among females (p < 0.001), inhabitants of the Croatian capital Zagreb (p = 0.001), subjects who were not infected with COVID-19 virus (p = 0.042), subjects who had fear of coronavirus infection in the workplace (p < 0.001), subjects who had fear of coronavirus infection during daily life activities (p < 0.001), subjects who had fear of coronavirus infection during daily physical activities (p < 0.001), subjects who worked with limited social contact (p = 0.005), and subjects with dysfunctional anxiety associated with the COVID-19 pandemic (p = 0.003).

Conclusions

Poor sleep quality is common during the COVID-19 pandemic in Croatia. Identifying factors associated with poor sleep would help develop specific intervention programs that enhance mental health and sleep quality during pandemics.

Key messages

• The COVID-19 pandemic has a significant negative influence on the mental health of the Croatian general population.

• Appropriate supportive programs and interventional approaches directed toward the general population are needed to address mental health problems in Croatia during the COVID-19 pandemic.

Salmonella Detection in Cocoa and Chocolate by Motility Enrichment on Modified Semi-Solid Rappaport-Vassiliadis Medium: Collaborative Study

A collaborative study was performed in 13 laboratories (including the authors’ laboratories) to validate motility enrichment on modified semi-solid Rap-paport-Vassiliadis (MSRV) medium for rapid detection of motile Salmonella in cocoa powder and chocolate. The MSRV method was compared with the AOAC standard culture method for detection of Salmonella in cocoa powder, milk chocolate, sweet chocolate, and dark chocolate. Chocolate samples were artificially inoculated with Salmonella at 2 levels of contamination. Cocoa powder was inoculated at 2 levels with naturally contaminated dust from cocoa beans. Uninoculated control samples were also included for each type of product. The sensitivity rate was 98.1 % for the MSRV method and 94.9% for the AOAC culture method. The specificity rate was 100.0% for both methods. There was no significant difference in the proportion of samples positive by MSRV and the AOAC culture methods for any of the food types. The MSRV method has been adopted first action by AOAC INTERNATIONAL.

Relative Effectiveness of Selenite Cystine Broth, Tetrathionate Broth, and Rappaport-Vassiliadis Medium for Recovery of Salmonella spp. from Raw Flesh, Highly Contaminated Foods, and Poultry Feed: Collaborative Study

A collaborative study was performed in 18 laboratories to validate use of Rappaport-Vassiliadis (RV) medium in the standard culture method for recovery of Salmonella spp. from raw, highly contaminated foods and poultry feed. RV medium made from its individual ingredients and incubated at 42�C was compared with selenite cystine (SC) broth incubated at 35�C and tetrathionate (TT) broth incubated at 35� and 43�C for effectiveness in recovery of Salmonella spp. Four artificially contaminated foods (oysters, frog legs, mushrooms, and shrimp) and poultry feed and one naturally contaminated food (chicken) were analyzed. The artificially contaminated foods were inoculated with single serovars of Salmonella at target levels of 0.04 colony-forming units (CFU)/g for the low level and 0.4 CFU/g for the high level. For analysis of 1125 test portions, RV medium (42�C) recovered Salmonellairom 409 test portions; TT (43�C), from 368 test portions; TT (35�C), from 310 test portions; and SC (35�C), from 334 test portions. Overall, RV medium was comparable with or better than other selective enrichments for recovery of Salmonella from the foods in this study, except mushrooms. From mushrooms, SC broth (35�C) recovered more positive test portions than did RV medium (42�C) and TT broth (43�C). The method for detection of Salmonella in raw, highly contaminated foods and

Comparison of in vitro test systems using bacterial and mammalian cells for genotoxicity assessment within the "health-related indication value (HRIV) concept

In numerous cases, the German health-related indication value (HRIV) concept has proved its practicability for the assessment of drinking water relevant trace substances (Umweltbundesamt 2003). The HRIV is based on the toxicological profile of a substance. An open point of the HRIV concept has been the assignment of standardized test procedures to be used for the assessment. The level of the HRIV is at its lowest as soon as the genotoxicity of the substance is detected. As a single test on its own, it is not sufficient enough to assess the human toxicological relevance of a genotoxic effect or exclude it in the case of a negative result; a reasonable test battery was required, technically oriented towards the already harmonized international, hierarchical evaluation for toxicological assessment of chemicals. Therefore, an important aim of this project was to define a strategy for the genotoxicological assessment of anthropogenic trace substances. The basic test battery for genotoxicity of micropollutants in drinking water needs to fulfill several requirements. Although quick test results are needed for the determination of HRIV, a high degree of transferability to human genotoxicity should be ensured. Therefore, an in vitro genotoxicity test battery consisting of the Ames fluctuation test with two tester strains (ISO 11350), the umu test and the micronucleus test, or from the Ames test with five tester strains (OECD 471) and the micronucleus test is proposed. On the basis of selected test substances, it could be shown that the test battery leads to positive, indifferent, and negative results. Given indifferent results, the health authority and the water supplier must assume that it is a genotoxic substance. Genetically modified tester strains are being sensitive to different chemical classes by expression of selected mammalian key enzymes for example nitroreductase, acetyltransferase, and glutathione-S-transferase. These strains may provide valuable additional information and may give a first indication of the mechanism of action. To check this hypothesis, various additional strains expressing specific human-relevant enzymes were investigated. It could be shown that the additional use of genetically modified tester strains can enhance the detectable substance spectrum with the bacterial genotoxicological standard procedures or increase the sensitivity. The additional use provides orienting information at this level as a lot of data can be obtained quite quickly and with little effort. These indications of the mechanism of action should be however verified with a test system that uses mammalian cells, better human cells, to check their actual relevance. The selection of appropriate additional tester strains has to be defined from case to case depending on the molecular structure and also still requires some major expertise.

Neurofibromatosis type 1 gene haploinsufficiency reduces AP-1 gene expression without abrogating the anabolic effect of parathyroid hormone

Approximately 50% of neurofibromatosis type 1 (NF1) patients exhibit skeletal pathology, such as premature osteoporosis or pseudoarthroses. Loss of neurofibromin deregulates Ras signal transduction to affect generation of mitogen-activated protein kinase and Akt, both of which have been implicated in parathyroid hormone (PTH) anabolic mechanisms. Our aim was to determine if loss of neurofibromin impaired the anabolic effect of PTH on bone mass. Nf1 heterozygote (Nf1(+/-)) and wild type (Nf1(+/+)) mice were treated with recombinant human PTH(1-34) or vehicle once daily for 3-28 days. PTH enhanced mRNA expression of c-fos, junB, and fra2 in the distal femur metaphyses of both genotypes; expression of these transcripts was consistently lower in PTH-treated Nf1(+/-) mice. Despite lowered c-fos expression in Nf1(+/-) mice, PTH increased bone mass equivalently in both genotypes by 28 days. Ex vivo, Nf1 heterozygosity was associated with increased inducible osteoclasts in PTH-treated bone marrow cells and impairment of the actin stress fiber and cyclic adenosine monophosphate response to PTH in osteoprogenitors. Lower c-fos expression was previously thought to abrogate PTH responsiveness. Our results suggest crosstalk might occur between Ras signal transduction and the protein kinase A pathway in Nf1(+/-) mice. Ras signal transduction does not appear to be essential for the anabolic actions of PTH on bone. Because PTH was effective in the absence of Nf1, it may offer a useful approach to treat osteoporosis in NF1 patients.

Osteoblast apoptosis and bone turnover

With the discoveries of different death mechanisms, an emerging definition of apoptosis is the process of cell death associated with caspase activation or caspase-mediated cell death. This definition accepts that caspases represent the final common mechanistic pathway in apoptosis. Apoptosis may be triggered either by activation events that target mitochondria or endoplasmic reticulum or by activation of cell surface "death receptors," for example, those in the tumor necrosis factor (TNF) superfamily. In the postnatal and adult skeleton, apoptosis is integral to physiological bone turnover, repair, and regeneration. The balance of osteoblast proliferation, differentiation, and apoptosis determines the size of the osteoblast population at any given time. Although apoptosis has been recorded in many studies of bone, the selective mechanisms invoked in the different models studied rarely have been identified. This review offers a broad overview of the current general concepts and controversies in apoptosis research and then considers specific examples of osteoblast apoptosis pertinent to skeletal development and to the regulation of bone turnover. In reviewing selected work on interdigital apoptosis in the developing skeleton, we discuss the putative roles of the bone morphogenetic proteins (BMPs), Msx2, RAR-gamma, and death inducer obliterator 1 (DIO-1). In reviewing factors regulating apoptosis in the postnatal skeleton, we discuss roles of cytokines, growth factors, members of the TNF pathway, and the extracellular matrix (ECM). Finally, the paradoxical effects of parathyroid hormone (PTH) on osteoblast apoptosis in vivo are considered in the perspective of a recent hypothesis speculating that this may be a key mechanism to explain the anabolic effects of the hormone. An improved understanding of the apoptotic pathways and their functional outcomes in bone turnover and fracture healing may facilitate development of more targeted therapeutics to control bone balance in patients with osteoporosis and other skeletal diseases.

Hepatitis B in the family

During a 3-year period (1992-1995), 239 index cases of hepatitis B virus (HBV) infection and 459 members of their households from the Osijek-Baranja county were examined. The aim of the study was to determine the spread of HBV infection in the families with a member verified as a virus carrier, and to identify the family members with the highest risk of infection according to kinship degrees. The retrospective and prospective methods were used in the study. The probable route of infection was assessed by the use of an epidemiologic questionnaire, and the serologic status of the study subjects concerning infection with HBV was determined by enzyme immunoassays (HBsAg, anti-HBs, anti-HBe and anti-HBc). The first member of a family identified as a virus carrier was considered an index case. HBV infection was demonstrated in 334 (47.85%) out of a total of 698 subjects. Only 21 (6.28%) of the 334 subjects with verified HBV infection developed the clinical picture of acute hepatitis B. The ratio of clinically manifest vs inapparent infection was 1:16. Serologic traces of infection were detected in 95 of the 459 family members of the index cases, yielding a mean rate of the infection among the virus carrier family members of 20.70%.

Military casualties in Baranja and east Slavonia during the first 9 months of the war in Croatia

The total number of Croatian Army soldiers killed in the period from the beginning of July 1991 until the end of March 1992 was 487. The number of severely wounded was 1,160, and 1,141 soldiers were slightly wounded. The ratio of the killed to wounded was 1:5, except in the municipality of Osijek, where it was 1:2.5. The number of casualties increased continually and culminated during November 1991, the period of fiercest fighting in this territory, followed by a gradual decrease. The most common mechanism of injury was explosives, which were responsible for almost half of all casualties (47.9%). An equal number of soldiers were killed by explosives and infantry weapons (46.4% and 44.9%, respectively). Casualties caused by motor vehicle crashes are not to be ignored, especially after the cease-fire agreement. Car crashes frequently resulted in death (from 4.5%-12.4%).

[The effect of cellulose diacetate dialysis membranes on lipids and lipoproteins in uremic patients]

The patients treated with hemodialysis have marked cardiovascular morbidity and mortality. Furthermore, lipid and lipoprotein disorders in these patients are well known. Since lipid and lipoprotein disorders are undoubtedly associated with cardiovascular morbidity and mortality, treatment of this group of patients should aim also at the correction of these disorders. The effect of hemodialysis with cellulose diacetate membranes on plasma lipids and lipoproteins was studied in 13 female patients followed-up for 4.5 months. Total cholesterol, triglycerides, HDL and LDL cholesterol, and apolipoproteins (a), AI and B were determined in each patient at the beginning and at the end of the study. Significant increases in HDL cholesterol (0.95 +/- 0.30-1.09 +/- 0.32 mmol/l), apolipoprotein B (1.14 +/- 0.35-1.35 +/- 0.36 g/l), and apolipoprotein (a) (272.38 +/- 281.66-357.36 +/- 400.30 U/l), nonsignificant increases in total cholesterol (5.61 +/- 1.18-5.63 +/- 1.23 mmol/l), LDL cholesterol (3.30 +/- 1.05-3.69 +/- 1.32 mmol/l) and apolipoprotein AI (1.03 +/- 0.25-1.11 +/- 0.19 g/l), and nonsignificant decrease in triglycerides (3.07 +/- 1.49-2.74 +/- 1.37 mmol/l) were found in the study. In conclusion, only some of the observed changes in plasma proteins and lipoproteins are beneficial for the patients.

Salmonella detection in cocoa and chocolate by motility enrichment on modified semi-solic Rappaport-Vassiliadis medium: collaborative study

A collaborative study was performed in 13 laboratories (including the authors' laboratories) to validate motility enrichment on modified semi-solid Rappaport-Vassiliadis (MSRV) medium for rapid detection of motile Salmonella in cocoa powder and chocolate. The MSRV method was compared with the AOAC standard culture method for detection of Salmonella in cocoa powder, milk chocolate, sweet chocolate, and dark chocolate. Chocolate samples were artificially inoculated with Salmonella at 2 levels of contamination. Cocoa powder was inoculated at 2 levels with naturally contaminated dust from cocoa beans. Uninoculated control samples were also included for each type of product. The sensitivity rate was 98.1% for the MSRV method and 94.9% for the AOAC culture method. The specificity rate was 100.0% for both methods. There was no significant difference in the proportion of samples positive by MSRV and the AOAC culture methods for any of the food types. The MSRV method has been adopted first action by AOAC INTERNATIONAL.

Collaborative study of the International Office of Cocoa, Chocolate and Sugar Confectionery on Salmonella detection from cocoa and chocolate processing environmental samples

A comparative collaborative study was performed in 13 laboratories to evaluate the use of motility enrichment on Modified Semisolid Rappaport-Vassiliadis medium for rapid Salmonella detection from food-processing environmental samples. Artificially contaminated chocolate scrapings and naturally contaminated cocoa bean dust samples were used in the study. Pre-enrichment was performed in buffered peptone water with added casein and malachite green oxalate. Motility enrichment was compared with a conventional cultural procedure using Rappaport-Vassiliadis broth and selenite cystine broth as selective enrichment. The productivity of motility enrichment was 93.5% compared to a productivity of the cultural procedure of 92%. Statistical analysis showed that there was no significant difference between the two procedures. Modified Semisolid Rappaport-Vassiliadis medium is a sensitive and simple diagnostic tool for the microbiological safety evaluation of food-processing environments.