University Hospital for Infectious Diseases "Dr Fran Mihaljevic"

Antitubercular drug-induced liver injury (ATDILI) poses a significant obstacle to successful tuberculosis treatment, including for tuberculous lymphadenitis. Its global incidence varies considerably, typically ranging from 2% to 30%, influenced by factors like patient demographics, co-morbidities, and geographical context. Despite some findings suggesting potentially lower rates in tuberculous lymphadenitis, the inherent hepatotoxic nature of standard anti-TB drugs means the risk remains clinically relevant. Key risk factors for ATDILI encompass older age, female gender, pre-existing liver conditions, HIV co-infection, malnutrition, alcoholism, and genetic polymorphisms, particularly in N-acetyltransferase 2 which affects isoniazid metabolism. The mechanisms of injury are drug-specific: isoniazid primarily causes hepatocellular damage via oxidative stress from toxic metabolites, while rifampicin induces cholestasis and endoplasmic reticulum stress, and pyrazinamide is linked to mitochondrial dysfunction. Management involves prompt withdrawal of antitubercular therapy when liver enzyme thresholds are exceeded, followed by careful reintroduction. Challenges are amplified in resource-limited settings due to higher prevalence of risk factors and limited access to consistent monitoring and sophisticated diagnostics. Promising advancements include safer regimens like the 3-month once-weekly isoniazid-rifapentine (3HP) for latent TB, which significantly reduces hepatotoxicity. The development of shorter active TB regimens and novel anti-TB drugs with improved safety profiles further aims to enhance treatment adherence and reduce ATDILI incidence, ultimately improving patient outcomes globally.

<title>Abstract</title> Aim This narrative review examines the impact of SARS-CoV-2 on dental practice, integrating evidence on transmission pathways, infection control, oral manifestations, vaccination, and long-term clinical and operational implications. Materials and Methods A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, and Cochrane Library, covering studies published between 2020 and 2025. Eligible studies addressed viral transmission within dental settings, infection-prevention strategies, clinical presentations, vaccination attitudes, and professional guidelines. Data were synthesized qualitatively and organized thematically to reflect the multidimensional impact of the pandemic. Results SARS-CoV-2 RNA was detected in the saliva of over 90% of infected individuals, while 40–45% of cases remained asymptomatic. The use of extraoral suction systems reduced aerosol contamination by up to 90%, and rubber dam application lowered aerosol generation by 80–99%. Oral manifestations occurred in 45–68% of patients, with dysgeusia being the most prevalent (45%). Vaccination acceptance among dental professionals reached 81%. However, healthcare workers still exhibited a high prevalence of long COVID (78%). Economic data indicated that 97% of dental practices closed except for emergencies during peak pandemic periods, while Croatian studies documented a 30.27% reduction in patient visits. The crisis also accelerated the global adoption of teledentistry for consultation and triage. Conclusions SARS-CoV-2 profoundly affected dental practice. Sustained implementation of infection-control protocols and adequate personal protective equipment remains essential, while persistent oral sequelae, such as taste disorders, require ongoing clinical monitoring. Level of Evidence Level 1 (systematic reviews, metaanalyses, RCTs) Level 2 (cohort studies) Level 3 (casecontrol, case series) Level 4 (expert opinion, guidelines, narrative reviews).

Parkinson's disease (PD) is characterised by α-synuclein aggregation, dopaminergic neuron loss and chronic neuroinflammation. Disruption of the blood-brain barrier enables immune cell infiltration, including dendritic cells (DCs) and CD4+ T-cells, contributing to disease progression. To explore peripheral immune mechanisms in PD, we isolated DCs and CD4+ T-cells from the blood of 17 PD patients and 10 controls using magnetic separation, followed by flow cytometry and single-cell RNA sequencing. Cell-type annotation identified CD4+ T-cell and DC subtypes, including rare DC3 cells. PD patients showed reduced circulating DCs, with no change in CD4+ T-cell levels. Differential gene expression and pathway analysis suggest CD4+ effector memory T-cells (TEMs) and cDC2s as important mediators of immune responses in PD, enriched for immune-related pathways including T-cell activation and antigen presentation. Our findings implicate specific immune subsets in PD-associated neuroinflammation, suggesting cDC2s and CD4+ TEMs as potential targets for immunomodulatory strategies.

Jedna od komplikacija akutnog pijelonefritisa jest bubrežni apsces, čije liječenje zahtjeva produljeno antimikrobno liječenje, a nerijetko i perkutanu drenažu. Zbog nespecifičnih simptoma uključujući i nalaze krvnih pretraga i pretraga urina, ovaj entitet potrebno je uzeti u obzir prvenstveno u diferencijalnoj dijagnozi akutnog pijelonefritisa kod sporog ili neuspješnog kliničkog odgovora na antimikrobno liječenje. U ovom radu prikazana je 86-godišnja bolesnica koja nije prethodno imala uroinfekcije niti je ozbiljnije bolovala, a hospitalizirana je zbog akutnog pijelonefritisa koji je bio kompliciran intrarenalnim apscesom i bakterijemijom uzrokovanima bakterijom Escherichia coli koja producira beta-laktamazu proširenog spektra. Radiološka detekcija bubrežnog apscesa bila je presudna za postavljanje konačne dijagnoze, kao i rezultati antimikrobne osjetljivosti koja je pokazala rezistenciju na empirijski započeto liječenje. U bolesnice je provedeno prolongirano liječenje te je provedena kontrola nakon otpusta, tijekom koje je i klinički i radiološki verificirana potpuna regresija bolesti.

Background: Ceftriaxone upregulates GLT1 glutamate transporter in the brain and may have anti-CFC and anti-OCD effects. Methods: Twenty WZ-5HT rats were used to investigate the effects of ceftriaxone on obsessive-compulsive (OCD)-like behaviour in the marble-burying (MB) test, freezing behaviour in contextual fear conditioning (CFC) and expression of GLT1 protein in the hippocampus or amygdala using immunoblots. Fifteen DBA/2J mice were used in the MB test. We also compared diazepam with ceftriaxone in open-field, beam-walking, and wire-hanging tests on 47 DBA/2J mice. Ceftriaxone (200 mg/kg) and saline were applied intraperitoneally, once daily for 7 (rats) or 5 (mice) consecutive days. A single dose of diazepam (1.5-3.0 mg/kg) or saline was injected 30 min before the behavioural tests. Results: Ceftriaxone significantly diminished OCD-like behaviour (↓ number of marbles buried) and freezing behaviour in CFC context session (↑ latencies, ↓ total duration, ↓ duration over four 2 min periods of the session) but increased GLT1 protein expression in the amygdala and hippocampus of rats. Diazepam induced sedation, ataxia and myorelaxation in mice. Ceftriaxone did not have these side effects. Conclusions: The results of this study confirm the anti-CFC and anti-OCD effects of ceftriaxone, which did not produce the unwanted effects typical of diazepam.

ObjectiveTo understand primary care physicians’ perspectives on academic detailing from an antimicrobial stewardship team to combat antibiotic overuse for upper respiratory infections and bronchitis in the COVID-19 era, which will help prevent avoidable outpatient visits.MethodsIn this prospective study, 14 female Croatian physicians completed standardized qualitative interviews using a semi-structured guide. The data were analyzed using inductive methodology based on reflexive thematic analysis. We used a theoretically informed approach based on a conceptual framework of healthcare intervention implementability focused on three domains: acceptability, fidelity, and feasibility.ResultsWe identified six key themes highlighting barriers to changing prescribing practices, with patient pressure and specialist recommendations having an impact on the effectiveness of academic detailing. Despite challenges, primary care physicians described appreciation of direct interaction with evidence-based practices and reported usefulness, effectiveness, and further need for academic detailing.ConclusionThis study highlights the complex dynamics involved in implementing healthcare interventions and provides valuable insights for enhancing strategies directed at improving antibiotic prescribing practices. Specifically, our findings emphasize factors influencing behavior changes in physicians’ antibiotic prescribing. The authors advocate for a collaborative approach involving community and hospital-based professionals to provide tailored guidance and address questions, ultimately improving prescribing practices.

Background and Objectives: John Cunningham polyomavirus (JCPyV) is a highly prevalent virus in the human population. The prevalence of JCPyV in patients with central nervous system disorders has not been examined extensively. The aim of this study was to analyze the prevalence of JCPyV DNA/antibodies in patients with neuroinvasive diseases (NID) of unknown etiology. Materials and Methods: The study included 132 patients with NID (febrile headache, meningitis, encephalitis) tested from January 2021 to December 2022. The control group consisted of 47 asymptomatic individuals. In patients with NID, serum and cerebrospinal fluid (CSF) samples were collected in the acute phase of the disease. CSF samples were tested for JCPyV DNA (PCR), while serum samples were tested for JCPyV IgG antibodies (ELISA). In controls, serum samples were tested for JCPyV IgG antibodies (ELISA). Results: JCPyV DNA was not detected in any of the CSF samples from patients with NID. JCPyV IgG antibodies were detected in 88.6% of patients and 74.5% of controls (p < 0.001). In the patients' group, a significant difference in the IgG prevalence was observed between males (94.6%) and females (81.0%). In addition, significant differences in the seropositivity between age groups were found. The lowest seroprevalence (28.6%) was in patients less than 20 years, followed by a sharp increase in the 20-29-year group (69.2%), after which the seroprevalence remained stable (90.0-94.1%) in patients up to 69 years. All patients older than 70 years were JCPyV IgG-seropositive. No significant difference in the seroprevalence was found in patients presenting with febrile headache (81.6%), meningitis (93.3%), or meningoencephalitis (91.3%). No difference in the seropositivity between genders was found in controls. Although the seropositivity steadily increased in older participants, these differences were not significant. Analyzing the JCPyV antibody levels in patients with NID, the median antibody titers differed significantly between groups, ranging from 248 AU/mL (younger age groups) to 400 AU/mL (older age groups). Conclusions: Higher seroprevalence in the patients' group highlights the need to further investigate the possible association of JCPyV and NID.

Hemorrhagic fever with renal syndrome (HFRS) is an acute zoonotic disease caused by viruses of the Orthohantavirus genus. This syndrome is characterized by renal and cardiopulmonary implications detectable with different biomarkers. Here, we explored the role of serum and urine levels of lipocalin-2, endothelin-1 and N-terminal pro-brain natriuretic peptide (NT-proBNP) in HFRS pathology. A total of twenty-eight patients hospitalized due to a Puumala orthohantavirus infection were included, with serum and urine samples collected on patient admission (acute phase) and discharge (convalescent phase). In comparison to healthy individuals, patients exhibited significantly higher acute-phase serum and urine levels of lipocalin-2, serum levels of endothelin-1 and serum and urine levels of NT-proBNP. Patients in the convalescent phase showed a significant decrease in urine lipocalin-2, serum endothelin-1 and serum and urine NT-proBNP levels. We recorded a strong correlation between serum levels of lipocalin-2 and endothelin-1 and urine levels of lipocalin-2 with several kidney injury markers, such as serum creatinine, urea, urine white blood cell count and proteinuria. We also demonstrated an independent correlation of serum and urine lipocalin-2 levels with acute kidney injury in HFRS. All in all, our results show an involvement of NT-proBNP, lipocalin-2 and endothelin-1 in the renal and cardiac pathology of HFRS.

Semaphorins have recently been recognized as crucial modulators of immune responses. In the pathogenesis of COVID-19, the activation of immune responses is the key factor in the development of severe disease. This study aimed to determine the association of serum semaphorin concentrations with COVID-19 severity and outcomes. Serum semaphorin concentrations (SEMA3A, -3C, -3F, -4D, -7A) were measured in 80 hospitalized adult patients with COVID-19 (moderate (n = 24), severe (n = 32), critical, (n = 24)) and 40 healthy controls. While SEMA3C, SEMA3F and SEMA7A serum concentrations were significantly higher in patients with COVID-19, SEMA3A was significantly lower. Furthermore, SEMA3A and SEMA3C decreased with COVID-19 severity, while SEMA3F and SEMA7A increased. SEMA4D showed no correlation with disease severity. Serum semaphorin levels show better predictive values than CRP, IL-6 and LDH for differentiating critical from moderate/severe COVID-19. SEMA3F and SEMA7A serum concentrations were associated with the time to recovery, requirement of invasive mechanical ventilation, development of pulmonary thrombosis and nosocomial infections, as well as with in-hospital mortality. In conclusion, we provide the first evidence that SEMA3A, SEMA3C, SEMA3F and SEMA7A can be considered as new biomarkers of COVID-19 severity.