Highlights What are the main findings? In-hospital adverse events were associated with higher 30-day mortality after hip fracture surgery. Baseline-only models, based on the ASA PS Classification, the Charlson Comorbidity Index, and the Elixhauser Comorbidity Index, showed broadly comparable discrimination for 30-day mortality in this cohort. What are the implications of the main findings? Routinely available comorbidity indices provided broadly similar short-term risk stratification, although their discrimination was acceptable rather than perfect. In-hospital adverse events should be interpreted as time-dependent clinical events associated with mortality rather than baseline predictors or evidence of causality. Abstract Background/Objectives: Hip fractures are associated with high short-term mortality in older adults. This study aimed to determine 30-day mortality after hip fracture surgery and evaluate factors associated with short-term mortality, with particular attention to baseline comorbidity indices and in-hospital adverse events. Methods: This retrospective cohort study included 785 patients who underwent surgery for hip fracture at University Hospital of Split, Croatia, between January 2021 and December 2022. Clinical data were extracted from medical records. The primary outcome was 30-day mortality, including in-hospital and post-discharge deaths. Associations with mortality were examined using univariable and multivariable logistic regression. Baseline-only comorbidity models were constructed using the American Society of Anesthesiologists Physical Status Classification System (ASA PS Classification), the Charlson Comorbidity Index (CCI), and the Elixhauser Comorbidity Index (ECI). Exploratory hospital-course models additionally included in-hospital adverse events, which were interpreted as time-dependent hospital-course events rather than baseline predictors. Results: 30-day mortality was 11.0% (86/785). Older age, male sex, higher comorbidity burden, and in-hospital adverse events were associated with mortality. Mortality was 5.7% without documented adverse events, 24.2% with one adverse event, and 42.4% with two or more adverse events. Baseline-only comorbidity models showed acceptable and broadly comparable discrimination, with AUCs of 0.73–0.77. Exploratory hospital-course models showed higher discrimination, with AUCs of 0.80–0.82. Conclusions: 30-day mortality after hip fracture surgery was associated with baseline patient vulnerability and in-hospital adverse events. Baseline-only models based on the ASA PS Classification, the CCI, and the ECI provided broadly comparable short-term risk stratification. In-hospital adverse events should be viewed as markers of an adverse clinical trajectory, not evidence of causality.

Background and Objectives: Vitamin D signaling plays critical roles in immune regulation, bone metabolism, and cellular differentiation across multiple tissues. However, the spatial and temporal expression patterns of key vitamin D signaling components—the vitamin D receptor (VDR) and the enzyme 1α-hydroxylase (encoded by CYP27B1)—during human nephrogenesis have not been mapped at the protein level. The primary objective of this study was to characterize VDR and 1α-hydroxylase expression across critical stages of human kidney development, complementing prior transcriptomic and single-cell descriptions, and to contextualize these developmental observations against the dysregulation of vitamin D pathway genes in adult renal and urothelial malignancies. Materials and Methods: Immunofluorescence analysis was performed on FFPE kidney tissue from 12 specimens (3 per stage) at 10, 22 and 38 gestational weeks and postnatally at 1.5 years. For each specimen, at least three non-adjacent sections were stained and 6 non-overlapping cortical fields were imaged at ×40 (18 fields per stage). Fluorescence-area percentages were quantified in ImageJ 1.54g, and group differences were assessed by one-way ANOVA with Tukey’s post hoc test at both field- and specimen-level. An accompanying bioinformatic analysis evaluated the differential expression of VDR, CYP27B1, and CYP24A1 in adult renal and urothelial malignancies (TCGA cohorts: KICH, KIRC, KIRP, BLCA) using unpaired Welch’s t-test, with Benjamini–Hochberg FDR correction applied across all 16 tumor-versus-normal comparisons (12 gene-wise + 4 post hoc log2(CYP24A1/CYP27B1) ratios). Results: VDR showed its highest mean fluorescence area at 10 weeks (3.40% (95% CI 3.24–3.56); field-level Tukey p < 0.0001 versus other stages) and its lowest at 22 weeks (0.69% (0.64–0.74)). 1α-hydroxylase was also highest at 10 weeks (5.44% (5.29–5.60); p < 0.0001) and stabilized at lower levels thereafter (3.04–4.26%). Co-expression of both proteins was observed throughout development except in 22-week glomeruli. In TCGA, all 12 significant gene-wise comparisons retained significance after BH FDR correction (q < 0.05). VDR showed cohort-specific dysregulation: reduced in KICH (q = 2 × 10−4) but increased in KIRC and KIRP (q = 2 × 10−4 for both). CYP24A1 was reduced in all three renal cohorts (q ≤ 0.029) and unchanged in BLCA. CYP27B1 showed cohort-specific direction (reduced in KIRC; increased in KICH, KIRP, and BLCA). Conclusions: This study provides an initial immunofluorescence-based spatial description of VDR and 1α-hydroxylase across human kidney development, revealing a coordinated redistribution from immature glomeruli at 10 weeks to mature tubular segments at later stages. The TCGA analysis demonstrates that vitamin D pathway dysregulation in renal carcinoma is cohort-specific and is not abolished by multiple-testing correction. Together, these results indicate that the developmentally engaged vitamin D pathway retains kidney-specific functional relevance in adult renal pathology and provide a baseline reference for future mechanistic studies.

Kidney transplantation remains the optimal treatment for end-stage renal disease, yet long-term allograft survival has plateaued due to persistent rejection. This review provides a comprehensive overview of the inflammatory and immune pathways implicated in kidney allograft rejection, integrating current evidence from basic and translational research. Ischemia–reperfusion injury initiates an inflammatory cascade through the release of damage-associated molecular patterns, activating Toll-like receptors and the complement system, thereby priming the alloimmune response. Innate immune cells, including macrophages, dendritic cells, and natural killer cells, bridge sterile tissue injury to adaptive alloimmunity, while the emerging concept of trained immunity reveals long-lasting epigenetic reprogramming of monocytes with direct implications for graft longevity. The adaptive response encompasses T cell-mediated rejection, driven by Th1, Th17, and CD8+ cytotoxic lymphocytes, and antibody-mediated rejection, mediated by donor-specific antibodies through complement activation and antibody-dependent cellular cytotoxicity. Key signalling pathways, including JAK-STAT, NF-κB, NLRP3 inflammasome, and mTOR, amplify allograft inflammation and promote progression toward chronic injury. Macrophage polarisation and macrophage-to-myofibroblast transition have been identified as major drivers of interstitial fibrosis and late graft failure. Recent advances in non-invasive biomarkers, such as donor-derived cell-free DNA and molecular phenotyping, are transforming rejection diagnostics. Emerging therapies, including costimulation blockade, anti-CD38 antibodies, complement inhibitors, and regulatory T cell-based approaches, offer the potential to shift transplant medicine toward precision-guided, tolerance-inducing strategies. This review synthesises these developments and discusses future perspectives for improving long-term allograft outcomes.

Background/Objectives: Clear cell renal cell carcinoma (ccRCC) is the most prevalent subtype of renal cancer, characterized by frequent metastasis and poor prognosis. Epithelial–mesenchymal transition (EMT) plays a pivotal role in tumor progression. Protocadherin 9 (PCDH9) has emerged as a potential tumor suppressor, but its relationship with EMT markers in ccRCC remains unclear. This study aimed to investigate the expression patterns and prognostic significance of PCDH9, β-catenin (CTNNB1), Snail (SNAI1), and Vimentin (VIM) in ccRCC. Methods: Immunofluorescence analysis was performed on formalin-fixed paraffin-embedded tissue sections from 48 ccRCC patients (31 low-grade, 17 high-grade) and adjacent normal renal cortex. Findings were validated using The Cancer Genome Atlas (TCGA-KIRC) dataset via GEPIA2/GEPIA3 platforms, including differential expression, correlation, and survival analyses. Results: PCDH9 mRNA was significantly downregulated in ccRCC tumors (TCGA-KIRC), while VIM was upregulated at the transcriptomic level. Tissue-level immunofluorescence quantification revealed discordant patterns, highlighting the influence of cellular heterogeneity on bulk protein assessment. The strong positive correlation between PCDH9 and CDH1 observed in normal kidney was completely lost in tumor tissue. Unexpectedly, PCDH9 showed positive correlations with EMT transcription factors (ZEB1, SNAI1) in tumors. In univariate survival analysis, high PCDH9 and CTNNB1 expression were associated with improved overall survival. Multivariate Cox regression revealed endpoint-specific prognostic signatures: VIM independently predicted disease progression, while SNAI1 predicted overall mortality. CTNNB1 was consistently protective across both endpoints. Conclusions: Our findings support a tumor-suppressive role for PCDH9 in ccRCC and reveal disruption of epithelial adhesion molecule co-regulation during tumorigenesis. The identification of endpoint-specific prognostic signatures has implications for patient stratification and suggests that ccRCC exhibits a partial EMT phenotype rather than classical EMT.

Background/Objectives: Clear cell renal cell carcinoma is the most common subtype of kidney cancer and exhibits marked biological heterogeneity, even among tumors of the same histological grade. Although tumor grade remains a key prognostic parameter, the molecular alterations associated with tumor differentiation are not fully understood. This study aimed to evaluate grade-dependent tissue-level expression patterns of proteins involved in cellular stress response, growth regulation, stemness, and apoptosis in clear cell renal cell carcinoma. Methods: Protein expression of heat shock protein 70, insulin-like growth factor 1, octamer-binding transcription factor 4, and apoptosis-inducing factor were analyzed in human clear cell renal cell carcinoma samples and normal renal cortex. Low-grade and high-grade tumors were compared using immunofluorescence staining combined with semi-quantitative and quantitative image analysis. The proportion of positive signals and the number of positive cells were assessed across tissue compartments. In addition, publicly available transcriptomic data from The Cancer Genome Atlas kidney renal clear cell carcinoma cohort were analyzed to explore associations between gene expression levels and overall survival. Results: Distinct grade-dependent expression patterns were observed for all investigated proteins. Heat shock protein 70, insulin-like growth factor 1, and octamer-binding transcription factor 4 showed a higher expression in normal renal tissue with a progressive reduction across tumor grades. In contrast, apoptosis-inducing factor exhibited increased expression in tumor tissue, particularly in low-grade tumors, with a relative decrease in high-grade carcinomas. Stromal compartments of tumor tissue showed minimal or no expression for most markers. Transcriptomic survival analysis did not reveal significant differences in overall survival between high- and low-expression groups for any of the investigated genes. Grade-stratified transcriptomic analysis of the TCGA KIRC cohort revealed consistent patterns for HSP70 family members and OCT4, with progressive grade-dependent mRNA reduction toward higher grades, while IGF1 showed an inverse mRNA trend and AIFM1 showed a uniform reduction across all tumor grades without a clear inter-grade pattern. Conclusions: The findings demonstrate that stress response, growth-related, stemness-associated, and apoptotic proteins display distinct grade-dependent tissue-level expression patterns in clear cell renal cell carcinoma, with the expression profiles of high-grade tumors being of particular translational interest given the aggressive clinical behavior and therapeutic resistance characteristic of this disease stage. These alterations appear to reflect tumor differentiation and biological behavior rather than independent prognostic value, highlighting the complexity of molecular regulation in renal tumorigenesis.

Background/Objectives: Growing evidence indicates that melatonin contributes to kidney development and function, while disruptions of fetal circadian signaling have been linked to congenital anomalies of the kidney and urinary tract (CAKUT). This study aimed to characterize the developmental and spatial expression patterns of melatonin receptors MTNR1A and MTNR1B in normal human fetal kidneys and in CAKUT phenotypes. Methods: This study analyzed 40 human fetal kidney specimens, including healthy controls and CAKUT cases (horseshoe kidneys, duplex kidneys, and dysplastic kidneys), obtained from spontaneous abortions and pregnancy terminations. Samples were classified into developmental phases Ph2–Ph4 according to established morphological criteria. Immunofluorescence staining was used to visualize MTNR1A and MTNR1B expression. Quantitative analysis was performed using ImageJ, measuring the fluorescence area percentage. Statistical comparisons were conducted using a two-way ANOVA. Results: In control kidneys, MTNR1A expression was predominantly observed in glomeruli and interstitial cells and showed a descending trend across developmental stages, whereas MTNR1B was localized to glomeruli and strongly to the apical membranes of tubules, particularly distal tubules, without substantial developmental variation. CAKUT phenotypes exhibited higher expression of both receptors compared to controls. Significant phase-dependent differences in MTNR1A expression were observed in horseshoe, duplex, and dysplastic kidneys. MTNR1B expression decreased across developmental stages in dysplastic kidneys and differed significantly between Ph3 and Ph4 in duplex kidneys. At Ph3, duplex kidneys showed the highest MTNR1B expression. Conclusions: Altered developmental expression patterns of MTNR1A and MTNR1B in CAKUT suggest an association between melatonin signaling and abnormal human kidney development.

Background/Objectives: Shoulder disorders are among the most prevalent musculoskeletal conditions, with lifetime prevalence reaching 67% and substantial associated disability and economic burden. Geographic barriers and workforce shortages impede access to optimal rehabilitation. This narrative review aims to synthesize current evidence on tele-diagnostics and tele-rehabilitation in shoulder disorders, evaluate clinical outcomes and implementation factors, and explore models for integrating these complementary approaches. Methods: A structured but non-systematic literature search was conducted across PubMed, Scopus, and Web of Science covering publications from January 2010 through December 2025, using terms related to telehealth, tele-rehabilitation, tele-diagnostics, and shoulder disorders. Priority was given to randomized controlled trials, systematic reviews, feasibility studies, and clinical practice guidelines in adult populations. A total of 97 articles were included in the final narrative synthesis. Results: Tele-diagnostic approaches demonstrate acceptable reliability for range-of-motion assessment and general diagnostic classification, though glenohumeral instability evaluation remains challenging remotely. Multiple randomized controlled trials suggest non-inferior outcomes for tele-rehabilitation compared to conventional physiotherapy across rotator cuff repair, shoulder arthroplasty, and conservative management, with generally high patient satisfaction. Certainty of evidence is currently low to moderate due to short follow-up durations, modest sample sizes, and heterogeneous protocols. Key implementation barriers include the digital divide, inability to deliver manual therapy, and insufficient long-term outcome data. Conclusions: Current evidence supports telehealth as a viable complement to conventional shoulder care, with the strongest evidence base for postoperative tele-rehabilitation. Hybrid care models appear clinically feasible, though widespread adoption requires standardized outcomes, longer-term trials, and strategies addressing health equity barriers.

Background/Objectives: Hidradenitis suppurativa (HS) is a chronic, immune-mediated inflammatory skin disease characterized by painful nodules, abscesses, sinus tracts, and progressive fibrosis. Vascular activation is becoming increasingly acknowledged as an important factor in HS pathogenesis; however, the effects of tumor necrosis factor alpha (TNF-α) blockade on vascular remodeling in HS remain poorly characterized. This study investigated the impact of TNF-α inhibition by adalimumab (ADA) on endothelial and fibroblast-associated markers in HS lesions. Methods: Formalin-fixed paraffin-embedded skin samples from 71 HS patients were analyzed, including treatment-naive (n = 38) and adalimumab-treated (n = 33) cases. Histopathology and immunofluorescence were performed using antibodies against CD31, von Willebrand factor (vWF), α-smooth muscle actin (αSMA), vimentin, Ki-67 (proliferation), and cleaved Caspase-3 (apoptosis). ImageJ software was used to determine the immunoexpression of selected markers and vascular density. Vascular density, assessed as vessel count per mm2, was designated as the primary endpoint. Sex-related differences were analyzed as exploratory endpoints. Results: Adalimumab-treated tissue exhibited significantly reduced vascular density (p < 0.01) compared to the treatment-naive group. Conversely, vimentin immunoexpression was significantly higher (p < 0.01) in the adalimumab-treated group. No significant differences were found in endothelial Ki-67 or cleaved Caspase-3 expression between treatment groups, indicating that the observed reduction in vascular density is not associated with direct effects on endothelial cell proliferation or apoptosis, but rather may occur indirectly through attenuation of the pro-angiogenic inflammatory milieu. Exploratory sex-stratified analysis revealed that treatment-naive males had significantly higher endothelial proliferation (Ki-67; p = 0.031) and vimentin expression (p = 0.017) compared to treatment-naive females. In the ADA-treated group, males exhibited significantly lower vascular density (p = 0.036) and higher endothelial apoptosis (p = 0.039) compared to females, whereas females showed a significant increase in vimentin expression following treatment (p = 0.008), suggesting possible sex-dependent differences in vascular remodeling. Conclusions: TNF-α blockade is associated with reduced vascular density, consistent with indirect anti-angiogenic effects, suggesting that adalimumab exerts disease-modifying effects on the microenvironment beyond inflammatory cytokine suppression. Sex-dependent differences in vascular regression underscore the importance of considering sex as a biological variable in HS pathogenesis and treatment response. These results highlight the significance of vascular interactions in HS and support adalimumab as a disease-modifying treatment. These exploratory findings require confirmation in longitudinal studies with paired biopsies.

Background/Objectives: Spontaneous intracerebral hemorrhage (sICH) is a particularly severe subtype of stroke, characterized by high rates of mortality and long-term disability, for which robust prognostic markers are still lacking. The aim of this study was to assess the relationship of the ICH score, the National Institutes of Health Stroke Scale (NIHSS) score, and serum high-sensitivity cardiac troponin I (hs-cTnI) levels with 30-day mortality in patients with sICH. Methods: We conducted a prospective observational cohort study enrolling 100 consecutive patients diagnosed with sICH based on neuroimaging findings. Demographic data, clinical parameters, neuroimaging findings, and serum hs-cTnI levels were collected on admission. Subsequently, the ICH score, its individual components, and the NIHSS score were assessed. Results: Patients who died were older and had significantly higher ICH and NIHSS scores, lower Glasgow Coma Scale (GCS) scores, larger hematoma volumes, more frequent intraventricular hemorrhage (IVH), and elevated hs-cTnI levels compared to survivors. Serum hs-cTnI concentrations were significantly correlated with ICH and NIHSS scores, lower GCS scores, larger hematoma volumes, and the presence of IVH. On univariate logistic regression, higher ICH score, NIHSS score, and hs-cTnI level were associated with mortality, whereas multivariate analysis identified the GCS score, hematoma volume, and IVH score as significant independent factors related to fatal outcome. Conclusions: Individual components of the ICH score may provide useful information on outcomes in patients with sICH. Higher serum hs-cTnI levels were associated with 30-day mortality but were not independent predictors. These markers may assist in patient monitoring and support established clinical procedures in therapeutic decision-making. Nevertheless, larger multicenter studies are needed to further clarify their clinical implications in sICH management.

Background/Objectives: Congenital anomalies of the kidney and urinary tract (CAKUTs) represent the leading cause of pediatric chronic kidney disease, yet the molecular mechanisms underlying these malformations remain incompletely understood. While genetic studies have identified numerous CAKUT-associated genes, conventional knockout approaches often result in embryonic lethality or fail to reveal tissue-specific gene functions. This review aims to synthesize findings from conditional knockout mouse studies that have elucidated the spatiotemporal requirements of key signaling pathways during kidney development. Methods: We conducted a narrative synthesis of studies employing Cre-loxP conditional gene targeting in mouse models, identified through systematic searches of PubMed and cross-referencing of key primary research. Studies were selected based on their use of lineage-specific Cre drivers (Six2-Cre, Hoxb7-Cre, Foxd1-Cre) to investigate nephron progenitor maintenance, ureteric bud branching morphogenesis, and stromal–epithelial interactions. Results: Conditional knockout studies have redefined CAKUT pathogenesis as a disorder of dose-dependent signaling, temporal regulation, and inter-compartmental communication. WNT/β-catenin signaling operates in a biphasic, dose-dependent manner in nephron progenitors, with Six2-Cre-mediated β-catenin deletion causing premature progenitor depletion. BMP and FGF pathways demonstrate dose-dependent and context-specific functions in progenitor maintenance, while GDNF/RET signaling is essential for ureteric bud outgrowth and branching. Importantly, stromal-specific deletions have uncovered non-cell-autonomous mechanisms regulating nephron formation. Haploinsufficiency studies demonstrate that partial pathway disruption can reduce nephron endowment without overt CAKUT, predisposing to adult-onset hypertension and chronic kidney disease. Conclusions: Conditional gene targeting has mechanistically redefined CAKUT from a collection of structural malformations to a spectrum of disorders arising from quantitative perturbations in lineage-specific signaling networks. These findings establish that phenotypic severity is determined by the degree of pathway disruption, the developmental timing of insult, and the compartment affected, providing a framework for interpreting oligogenic interactions and variable penetrance in human CAKUTs.