Precise genetic control of ATOH1 enhances maturation of regenerated hair cells in the mature mouse utricle.

Vestibular hair cells are mechanoreceptors critical for detecting head position and motion. In mammals, hair cell loss causes vestibular dysfunction as spontaneous regeneration is nearly absent. Constitutive expression of exogenous ATOH1, a hair cell transcription factor, increases hair cell regeneration, however, these cells fail to fully mature. Here, we profiled mouse utricles at 14 time points, and defined transcriptomes of developing and mature vestibular hair cells. To mimic native hair cells which downregulate endogenous ATOH1 as they mature, we engineered viral vectors carrying the supporting cell promoters GFAP and RLBP1. In utricles damaged ex vivo, both CMV-ATOH1 and GFAP-ATOH1 increased regeneration more effectively than RLBP1-ATOH1, while GFAP-ATOH1 and RLBP1-ATOH1 induced hair cells with more mature transcriptomes. In utricles damaged in vivo, GFAP-ATOH1 induced regeneration of hair cells expressing genes indicative of maturing type II hair cells, and more hair cells with bundles and synapses than untreated organs. Together our results demonstrate the efficacy of spatiotemporal control of ATOH1 overexpression in inner ear hair cell regeneration.

Comprehensive Analysis of Yoghurt Made with the Addition of Yellow Mealworm Powder (Tenebrio molitor).

The study aimed to be able to incorporate mealworm powder into yoghurts to increase protein content. Tenebrio molitor is gaining popularity as an alternative protein source. In the face of a growing human population and the associated challenges of sustainable nutrition, mealworms offer a promising solution. The mealworm is distinguished by its high protein content and for being rich in essential amino acids, vitamins, and minerals, making it a valuable component of diet. Among others, chemical composition, colour, texture, degree of syneresis, sensory analysis, and microbiological analysis were analysed. As expected, the addition of insect powder increased the protein content from 4.91% (0 TM) to 7.41% (5 TM). It also increased the fat content from 1.67% (0 TM) to 3.88% (5 TM). Furthermore, the addition of mealworm powder resulted in a significant change in the colour of the yoghurt to a darker colour, due to the dark brown colour of the powder. Food with added edible insects is increasingly available but is not always popular due to cultural and psychological barriers. Sensory analysis of yoghurts has shown that the more powder that is added, the less appealing the product becomes and the more bitter the taste.

Use of House Cricket (Acheta domesticus) Powder in Yoghurt Products.

This study aims to implement and increase values regarding the use of cricket powder in food. This is due to the need to increase the range of products enriched with cricket powder in order to increase the market and acceptance of insects in the diet. The work analyzed properties of yoghurt with cricket powder added (chemical composition, acidity, colour, consistency, degree of syneresis, texture and sensory analysis). Research has shown that the greater the addition of cricket powder, the higher the protein, fat and dry matter content and the lower the hardness of the yoghurt. As the content of cricket powder in yoghurt increased, the brightness (L*) and redness (a*) decreased, while the yellowness (b*) of the samples increased. A change in the colour of the yoghurt was observed with the increase in the cricket powder content; the yoghurt had a darker, browner colour. The best overall sensory rating compared to the control variant (6.4) was given to the yoghurt with 1.5% cricket powder added (5.7), while the worst rating was given to the yoghurt with 5% powder added (2 points out of 7).

Dynamic water profile in various types of cheese analyzed by means of nuclear magnetic resonance relaxometry.

The aim of the study was to enquire to which extend 1H spin-lattice nuclear magnetic resonance (NMR) relaxometry data collected over a broad range of resonance frequencies (from 10 kHz to 10 MHz) have the potential to be used for assessing quality and authenticity of different categories of cheese. The following cheeses were selected mozzarella, processed cheese, pizza cheese, pizza cheese with modified fat phase), low-fat cheese, and long ripened cheese. The cheeses from 3 different production plants and various cheese production batches were used in the study. The samples from each group were subjected to instrumental composition analysis (FoodScan analyzer type 78810, FOSS, Hillerod, Denmark), water activity assessment (Aqualab 4TEV analyzer, type S40001855) and nuclear magnetic resonance relaxation dispersion study (SMARtracer FFC relaxometer, Stelar S.r.l, Italy). The state and dynamics of water present in products as free and bound water largely determines the properties of food products, including cheeses. Nuclear magnetic resonance relaxometry studies of cheese enable to reveal relaxation features characteristic of specific categories of cheese. Consequently, the studies can be treated as a step toward exploiting NMR relaxometry for accessing quality and authenticity of cheese. It was shown that at low resonance frequencies, the lower the moisture, the larger the relaxation rate. The durability and quality of cheeses depend on the presence and condition of water, so it is necessary to find a relationship between the presence, condition and mobility of water in cheeses, to increase and improve the quality and extend the shelf life.

Health Outcomes of Judo Training as an Organized Physical Activity for Children and Adolescents: A Literature Review.

Judo, an organized physical activity for children and adolescents, has gained popularity worldwide. Physical activity is vital during times of rising obesity and a sedentary lifestyle in this age group. The article aims to review the current knowledge of the health benefits of judo-specific exercises for children and youth. Six international scientific databases (PubMed, Scopus, UpToDate, Web of Science, EBSCOhost, and Google Scholar) were searched from 1 January 2007 to 30 September 2022. The search focused on health-related factors regarding healthy preschool and school-aged judo practitioners. Sixteen original studies met the inclusion criteria. School-aged children aged 7-15 years were included in the analysis. The average training time was between two and six hours a week, with the judo intervention mainly ranging from nine months to three years. Most studies registered positive changes caused by judo training. The outcomes focused on maintaining or reducing body fat, increasing bone mineralization, and improving the function of the cardiorespiratory system compared to the non-practicing control group. However, there were no differences between judo and other sports groups. The main conclusions presented health benefits from judo-specific training in school-aged children and may support the World Health Organization recommendations concerning daily physical activity.

Stethoscopes or Maybe "Bacterioscopes" - Is hand Hygiene Solely Capable of Preventing Hospital-Associated Infections?

The stethoscope remains an indispensable diagnostic tool for medical students. Improper stethoscope hygiene may cause bacterial infections, including hospital-associated infections (HAIs), which challenge the Polish medical system. The study's main objective was to evaluate the hygiene habits declared by medical students. Moreover, microbiological control with the characteristics of potentially pathogenic microorganisms was performed. The study included 66 medical students from the Faculty of Medicine at the Jagiellonian University Medical College in Cracow, Poland. The participants filled in an anonymous questionnaire. Stethoscope contamination was assessed through isolation, identification, testing of antibiotic resistance, and clonality of the isolates bacterial pathogens. The survey showed that only 30.3% of students cleaned their stethoscopes after each patient, and 1.5% never did this. Of the 66 stethoscopes tested, 100% were positive for bacterial growth. Staphylococcus spp. was the most frequently isolated contaminant (50.5%). The questionnaire results demonstrated the necessity of the validated procedures for cleaning the stethoscopes. Stethoscopes used by medical students are contaminated with numerous bacterial species, including multidrug-resistant organisms. The clonal structure of the MRSA and MRSE populations acquired from stethoscopes has been demonstrated. Our results confirm the possibility that these medical devices mediate the spread of hazardous pathogens in the hospital environment. Practical exercises are essential to forming the correct hygiene habits involving stethoscopes, which enable practicing and checking the correctness of the established skills.

Effect of in vitro cultivation on human gut microbiota composition using 16S rDNA amplicon sequencing and metabolomics approach.

Gut microbiota (GM) plays many key functions and helps maintain the host's health. Consequently, the development of GM cultivation under in vitro stimulating physiological conditions has gained extreme interest in different fields. In this study, we evaluated the impact of four culture media: Gut Microbiota Medium (GMM), Schaedler Broth (SM), Fermentation Medium (FM), and Carbohydrate Free Basal Medium (CFBM) on preserving the biodiversity and metabolic activity of human GM in batch in vitro cultures using PMA treatment coupled with 16S rDNA sequencing (PMA-seq) and LC-HR-MS/MS untargeted metabolomics supplemented with GC-MS SCFA profiling. Before the experiments, we determined the possibility of using the pooled faecal samples (MIX) from healthy donors (n = 15) as inoculum to reduce the number of variables and ensure the reproducibility of in vitro cultivation tests. Results showed the suitability of pooling faecal samples for in vitro cultivation study. Non-cultured MIX inoculum was characterized by higher α-diversity (Shannon effective count, and Effective microbial richness) compared to inocula from individual donors. After 24 h of cultivation, a significant effect of culture media composition on GM taxonomic and metabolomic profiles was observed. The SM and GMM had the highest α-diversity (Shannon effective count). The highest number of core ASVs (125) shared with non-cultured MIX inoculum and total SCFAs production was observed in the SM. These results might contribute to the development of standardized protocols for human GM in vitro cultivation by preventing methodological bias in the data.

Application of In Vitro Models for Studying the Mechanisms Underlying the Obesogenic Action of Endocrine-Disrupting Chemicals (EDCs) as Food Contaminants-A Review.

Obesogenic endocrine-disrupting chemicals (EDCs) belong to the group of environmental contaminants, which can adversely affect human health. A growing body of evidence supports that chronic exposure to EDCs can contribute to a rapid increase in obesity among adults and children, especially in wealthy industrialized countries with a high production of widely used industrial chemicals such as plasticizers (bisphenols and phthalates), parabens, flame retardants, and pesticides. The main source of human exposure to obesogenic EDCs is through diet, particularly with the consumption of contaminated food such as meat, fish, fruit, vegetables, milk, and dairy products. EDCs can promote obesity by stimulating adipo- and lipogenesis of target cells such as adipocytes and hepatocytes, disrupting glucose metabolism and insulin secretion, and impacting hormonal appetite/satiety regulation. In vitro models still play an essential role in investigating potential environmental obesogens. The review aimed to provide information on currently available two-dimensional (2D) in vitro animal and human cell models applied for studying the mechanisms of obesogenic action of various industrial chemicals such as food contaminants. The advantages and limitations of in vitro models representing the crucial endocrine tissue (adipose tissue) and organs (liver and pancreas) involved in the etiology of obesity and metabolic diseases, which are applied to evaluate the effects of obesogenic EDCs and their disruption activity, were thoroughly and critically discussed.

Hepatitis B in Poland in 2021.

Objective: Evaluation of the epidemiological situation of hepatitis B in Poland in 2021 compared to previous years, considering the impact of the COVID-19 pandemic. Material and methods: Data from individual reports on hepatitis B cases and HBV infections registered by local sanitary and epidemiological stations in the EpiBaza system were analyzed. Aggregate data published in the annual bulletins: "Infectious diseases and poisonings in Poland", "Vaccinations in Poland" and data on deaths provided by the Demographic Surveys Department of Statistics Poland (GUS) were also used. Results: In 2021, a total of 1,547 cases of hepatitis B were registered, including 10 cases of acute hepatitis B, with an incidence of acute hepB 0.03/100,000 population. The incidence of acute hepB was lower by 25% than in 2020 and lower by 75% than the median incidence for 2015-2019. Acute cases occurred only in 6 voivodeships, all in people over 28 years of age. Two out of 10 acute cases were classified as imported. In 2021, 1,537 chronic or unknown-phase cases (UNK) were reported and registered, the diagnosis rate was 4.03/100,000 and was higher by 58% than the rate in 2020 and lower by 53% than the median for 2015-2019. The distribution of cases by gender, age and place of residence was similar to that observed previously - chronic cases or UNK were diagnosed more often in men (male-to female ratio 1.5:1) and people living in cities. Two chronic infections have been reported in infants born to HBV-infected women. 2.5% of chronic and UNK cases were considered imported. According to Statistics Poland (GUS), 20 people died in 2021, including 3 due to acute hepatitis B. The vaccination coverage of 1-year-olds with 3 doses of hepatitis B vaccine (HepB3) decreased slightly compared to 2020 and amounted to 89.3%. Conclusions: In the second year of the COVID-19 pandemic, a gradual levelling of the sharp decline in the number of diagnosed chronic and UNK cases that occurred in 2020 was observed. In acute cases, a further decline in incidence was noted compared to 2020, but a smaller number of acute cases was most likely due to the lower effectiveness of surveillance during the COVID-19 pandemic, rather than from an improvement in the epidemiological situation. The vaccination coverage of children in the second year of life (born in 2020) with the third dose of HepB vaccine continued to decline, although slightly.

Bacterial Pathogens in the Food Industry: Antibiotic Resistance and Virulence Factors of Salmonella enterica Strains Isolated from Food Chain Links.

Salmonella is one of the most important foodborne pathogens. Fifty-three strains of Salmonella deposited in the Culture Collection of Industrial Microorganisms-Microbiological Resources Center (IAFB) were identified using molecular and proteomic analyses. Moreover, the genetic similarity of the tested strains was determined using the PFGE method. Main virulence genes were identified, and phenotypical antibiotic susceptibility profiles and prevalence of resistance genes were analyzed. Subsequently, the occurrence of the main mechanisms of ß-lactam resistance was determined. Virulence genes, invA, fimA, and stn were identified in all tested strains. Phenotypic tests, including 28 antibiotics, showed that 50.9% of the strains were MDR. The tet genes associated with tetracyclines resistance were the most frequently identified genes. Concerning the genes associated with ESBL-producing Salmonella, no resistance to the TEM and CTX-M type was identified, and only two strains (KKP 1597 and KKP 1610) showed resistance to SHV. No strains exhibited AmpC-type resistance but for six Salmonella strains, the efflux-related resistance of PSE-1 was presented. The high number of resistant strains in combination with multiple ARGs in Salmonella indicates the possible overuse of antibiotics. Our results showed that it is necessary to monitor antimicrobial resistance profiles in all food chain links constantly and to implement a policy of proper antibiotic stewardship to contain or at least significantly limit the further acquisition of antibiotic resistance among Salmonella strains.

Hepatitis B in Poland in 2020.

OBJECTIVE: Aim of the study was the assessment of hepatitis B epidemiological situation in Poland in 2019 compared to previous years, taking into consideration the impact of the COVID-19 pandemic during that time. MATERIAL AND METHODS: Data for 2020 included in individual reports on hepatitis B and HBV infections recorded by sanitary and epidemiological stations at EpiBaza, i.e. in the electronic epidemiological surveillance system on infectious diseases, were analyzed. In the assessment of the epidemiological situation, data published in the annual bulletins: "Infectious diseases and poisonings in Poland in 2020" and "Vaccinations in Poland in 2020" were also used. Data on deaths were obtained from the Statistics Poland (GUS). RESULTS: In 2020, 2,854 cases of hepatitis B were reported, which corresponds to the incidence of 2.59 per 100,000 population, lower by 65.1% than in 2019. 14 cases of acute hepatitis B were reported, constituting 1.4% of all registered cases. The incidence of acute hepatitis B was 0.04 per 100,000 population and was lower by 67% compared to 2019 and lower by 71% compared to the median for the years 2014-2018. There were no cases of acute disease in the age group 0-29 years. A total of 978 chronic and unknown hepatitis B cases (UNK) were registered and the diagnosis rate was 2.56 per 100,000 population, lower by 64.2% than in 2019. Compared to the median diagnosis rate of chronic hepatitis B in 2014-2018, a decrease of 70.4% was observed. In the age group 0-19 years, there was no case reported. In 2020, 24 people died due to hepatitis B, including 22 from chronic hepatitis B. CONCLUSIONS: The COVID-19 pandemic resulted in a significant reduction in the number of HBV tests performed and, consequently, a reduction in the number of diagnosed infections. A decrease in the number of detected infections was observed from the second quarter of 2020, i.e. from the beginning of the COVID-19 pandemic, although already in the first quarter of 2020 the number of registered hepatitis B cases was lower than in the same period in 2019. No acute cases were reported among people who were vaccinated against hepatitis B during childhood. Vaccination with three doses of hepatitis B vaccine in children in the second year of life was only slightly lower than in 2019, which proves the stability of the implementation of the preventive vaccination program, despite the limited access to primary health care during the pandemic.

The attitude of Polish women planning pregnancy and/or having children towards vaccinations: a cross-sectional survey study.

OBJECTIVES: Infectious diseases in pregnant women can cause birth defects. Implementing appropriate prevention methods while planning pregnancy can help avoid some of them. MATERIAL AND METHODS: A cross-sectional survey study was performed. The questionnaire investigated attitudes towards vaccinations, as well as opinions on anti-vaccine movements and the so-called "chickenpox parties". The questionnaire was developed for the purpose of this study and the survey was conducted using the google form, which was posted on social media groups for women planning pregnancy, being pregnant or for mothers' groups from Poland. RESULTS: The study group consisted of 2402 women; their median age was 31 years (range 16-54 years). Most women were from cities > 100,000 inhabitants (49.7%, 1194/2402) and had higher education (71.9%, 1726/2402). A positive attitude towards vaccinations was more common among younger, nulliparous women from big cities (p = 0.02, p = 0.04 and p = 0.01, respectively). 2068/2402 (86.1%) of respondents were not vaccinated before pregnancy and 1931/2402 (80.4%) of women were not vaccinated during pregnancy. While most women (1545/2402, 64.3%) considered vaccination safe, and effective (1904/2402, 79.3%) against infectious diseases, many (n = 296/2402 12.3%) have no opinion on the so-called chickenpox party. CONCLUSIONS: Most surveyed women had a positive attitude towards vaccinations and consider vaccines a safe and effective method of protection against infectious diseases. Since a significant proportion of women were not vaccinated before or during pregnancy and about 12% of women are undecided, the physician's role is crucial in educating and persuading the patient to be vaccinated.

Reply to van Lingen et al. Comment on "Szczubelek et al. Effectiveness of Crohn's Disease Exclusion Diet for Induction of Remission in Crohn's Disease Adult Patients. Nutrients 2021, 13, 4112".

Thank you for your comment and interest [...].

Principles of Judo Training as an Organised Form of Physical Activity for Children.

When organising judo training for children, it is essential to ensure maximum safety, and use an appropriate training methodology adapted to the age of the youngest judo athletes. This paper aims to review the current literature containing judo training principles and safety-related considerations for preschool (4-6 years) and school-age (7-12 years) children as an organised physical activity. Data were collected until October 2021 from eight international scientific databases (PubMed, Scopus, UpToDate, Web of Science, Cochrane, EBSCOhost, ScienceDirect, Google Scholar). In the overviews, we found various times and frequencies of judo training for children. In preschool, the training time was 30-60 min with a frequency of 2-3 times per week, whereas in the school-age group, the training time was extended from 45 to 90 min 3-4 times per week. The most common injuries included upper arm injuries, followed by those of the lower limbs. In the future, it would be an advantage to systematise the methodology of judo training as an organised form of physical activity that can complement the daily dose of exercises recommended by the World Health Organization for maintaining children's general health.

Analysis of Preventable Risk Factors for Toxoplasma gondii Infection in Pregnant Women: Case-Control Study.

BACKGROUND: Toxoplasma gondii (TG) is a parasitic protozoon that may cause miscarriages or birth defects if the infection occurs during pregnancy. The study's aim was to evaluate the risk factors associated with TG infection in pregnant women. MATERIALS: Medical charts for all 273 pregnant women with suspected TG infection consecutively admitted to the Hospital of Warsaw between 2019 and 2020 were retrospectively analyzed. The presumptive TG diagnosis was verified by a serologic assessment of IgM and IgG titers, and IgG affinity tests. RESULTS: The median age was 32 years (range: 19-42 years). The diagnosis of primary TG infection was confirmed in 74/273 (27.1%) women. In 114/273 (41.8%) there was evidence of past infection. In 71/273 (26%) women, an infection was excluded. In 172/273 (62%) women the recommended testing for other infectious diseases putting fetus development at risk was performed correctly. Logistic regression model analysis revealed that living in rural areas and eating raw meat were independent factors associated with increased risk of TG infection during pregnancy (OR 2.89, 95% CI: 1.42-5.9, p = 0.004; and OR 2.07, 95% CI: 1.03-4.18, p = 0.04, respectively). CONCLUSIONS: The independent risk factors for TG infection during pregnancy include living in rural areas and eating raw meat. The physician's educational role here is crucial for the efficient prevention of congenital toxoplasmosis.

Characterization and Genome Study of Novel Lytic Bacteriophages against Prevailing Saprophytic Bacterial Microflora of Minimally Processed Plant-Based Food Products.

The food industry is still searching for novel solutions to effectively ensure the microbiological safety of food, especially fresh and minimally processed food products. Nowadays, the use of bacteriophages as potential biological control agents in microbiological food safety and preservation is a promising strategy. The aim of the study was the isolation and comprehensive characterization of novel bacteriophages with lytic activity against saprophytic bacterial microflora of minimally processed plant-based food products, such as mixed leaf salads. From 43 phages isolated from municipal sewage, four phages, namely Enterobacter phage KKP 3263, Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 have lytic activity against Enterobacter ludwigii KKP 3083, Citrobacter freundii KKP 3655, Enterobacter cloacae KKP 3082, and Serratia fonticola KKP 3084 bacterial strains, respectively. Transmission electron microscopy (TEM) and whole-genome sequencing (WGS) identified Enterobacter phage KKP 3263 as an Autographiviridae, and Citrobacter phage KKP 3664, Enterobacter phage KKP 3262, and Serratia phage KKP 3264 as members of the Myoviridae family. Genome sequencing revealed that these phages have linear double-stranded DNA (dsDNA) with sizes of 39,418 bp (KKP 3263), 61,608 bp (KKP 3664), 84,075 bp (KKP 3262), and 148,182 bp (KKP 3264). No antibiotic resistance genes, virulence factors, integrase, recombinase, or repressors, which are the main markers of lysogenic viruses, were annotated in phage genomes. Serratia phage KKP 3264 showed the greatest growth inhibition of Serratia fonticola KKP 3084 strain. The use of MOI 1.0 caused an almost 5-fold decrease in the value of the specific growth rate coefficient. The phages retained their lytic activity in a wide range of temperatures (from -20 °C to 50 °C) and active acidity values (pH from 4 to 11). All phages retained at least 70% of lytic activity at 60 °C. At 80 °C, no lytic activity against tested bacterial strains was observed. Serratia phage KKP 3264 was the most resistant to chemical factors, by maintaining high lytic activity across a broader range of pH from 3 to 11. The results indicated that these phages could be a potential biological control agent against saprophytic bacterial microflora of minimally processed plant-based food products.

Effectiveness of Crohn's Disease Exclusion Diet for Induction of Remission in Crohn's Disease Adult Patients.

Exclusive enteral nutrition (EEN) is a first-line treatment in active, mild to moderate Crohn's disease (CD) in children. The Crohn's disease exclusion diet (CDED), which avoids products known to have a pro-inflammatory effect on the intestinal mucosa, presents similar effectiveness to EEN for inducing remission in the paediatric population. The aim of the study was to evaluate the effectiveness of the CDED in inducing remission in adult patients. Between March 2020 and May 2021, 32 patients in a gastroenterology outpatient centre were treated according to the assumptions of the CDED. The patients were seen at baseline, at week 6, and at week 12 of the study. During the visits, anthropometric measurements and laboratory tests were performed, Crohn's disease activity index (CDAI) was calculated, and the Inflammatory Bowel Disease Questionnaire (IBDQ) was completed. The study included a total of 32 participants, 18 women (56.3%) and 14 men (43.7%). Clinical remission was obtained in 76.7% patients after 6 weeks and in 82.1% after 12 weeks of therapy. Calprotectin levels were significantly lower in the second follow-up compared with baseline (p = 0.021). The CDED is an effective therapy for inducing remission in the adult CD population.

Evaluation of selected health behaviours in patients with inflammatory bowel diseases - a preliminary report.

In treating inflammatory bowel diseases (IBD), regular physical activity (PA) and healthy behaviours play an increasingly important role. AIM: The aim of the study was to analyse PA with motivation to undertake it, health behaviours, and level of self-esteem in individuals with IBD. MATERIALS AND METHODS: The study involved 50 (mean age 39.1±11.5 years) adults with IBD hospitalised in Poznan. The control group consisted of 50 (mean age 40.7±9.1 years) healthy volunteers. The survey included sociodemographic data, Inventory of Physical Activity Objectives (IPAO), Inventory of Health Behaviours (IHB), and Rosenberg self-esteem scale. Differences between groups were calculated using the Mann-Whitney test (p<0.05). RESULTS: Most respondents of both groups did not undertake any PA. The values of IPAO categories in a group with IBD were significantly higher compared to the control group. Also, people with IBD had a statistically more significant value of general intensity index of health behaviour and statistically higher self-esteem than a group of healthy people. CONCLUSIONS: We found that people with IBD show a greater awareness of the impact of their health behaviour on their health when compared to control. However, the authors recorded the unsatisfactory level of motivation to undertake daily PA and practical pro-health activities. In treating these chronically ill patients, physicians should pay more attention to adequate education and motivation for regular exercise and appropriate health behaviours in everyday life.

Acute Hepatitis B and Unusual Follow-Up in a 16-Year-Old Boy: Case Report.

In this case report, we present a 16-year-old Ukrainian boy with acute hepatitis B. He had not been previously vaccinated against hepatitis B. Possible sources of infection included: a tattoo made at home, a finger cut made with hairdresser scissors during work, and unprotected sexual encounters. The clinical course of the disease was typical with jaundice and elevated aminotransferases levels without liver failure. During the follow-up visit 16 months after the onset of the disease, chronic hepatitis b was excluded but an ulcer around his anus was found. Additional tests for sexually transmitted diseases were ordered and they were positive for syphilis. The extended interview revealed that the patient had several unprotected bisexual encounters, which may have indicated a potential source of infections including the hepatitis B virus (HBV). The reported case shows that despite the significant decrease in the hepatitis B prevalence in Poland, the infection is still possible. It is necessary to conduct epidemiological interviews regarding sexually transmitted diseases in teenagers, especially when a blood-borne disease has been diagnosed.

Blood and immune development in human fetal bone marrow and Down syndrome.

Haematopoiesis in the bone marrow (BM) maintains blood and immune cell production throughout postnatal life. Haematopoiesis first emerges in human BM at 11-12 weeks after conception1,2, yet almost nothing is known about how fetal BM (FBM) evolves to meet the highly specialized needs of the fetus and newborn. Here we detail the development of FBM, including stroma, using multi-omic assessment of mRNA and multiplexed protein epitope expression. We find that the full blood and immune cell repertoire is established in FBM in a short time window of 6-7 weeks early in the second trimester. FBM promotes rapid and extensive diversification of myeloid cells, with granulocytes, eosinophils and dendritic cell subsets emerging for the first time. The substantial expansion of B lymphocytes in FBM contrasts with fetal liver at the same gestational age. Haematopoietic progenitors from fetal liver, FBM and cord blood exhibit transcriptional and functional differences that contribute to tissue-specific identity and cellular diversification. Endothelial cell types form distinct vascular structures that we show are regionally compartmentalized within FBM. Finally, we reveal selective disruption of B lymphocyte, erythroid and myeloid development owing to a cell-intrinsic differentiation bias as well as extrinsic regulation through an altered microenvironment in Down syndrome (trisomy 21).