Hydroxymethylglutaryl-CoA reductase activity is essential for mitochondrial β-oxidation of fatty acids to prevent lethal accumulation of long-chain acylcarnitines in the mouse liver

BACKGROUND AND PURPOSE

Statins are competitive inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGCR), and exert adverse effects on mitochondrial function, although the mechanisms underlying these effects remain unclear. We used a tamoxifen-induced Hmgcr-knockout (KO) mouse model, a multi-omics approach and mitochondrial function assessments to investigate whether decreased HMGCR activity impacts key liver energy metabolism pathways.

EXPERIMENTAL APPROACH

We established a new mouse strain using the Cre/loxP system, which enabled whole-body deletion of Hmgcr expression. These mice were crossed with Rosa26Cre mice and treated with tamoxifen to delete Hmgcr in all cells. We performed transcriptomic and metabolomic analyses and thus evaluated time-dependent changes in metabolic functions to identify the pathways leading to cell death in Hmgcr-KO mice.

KEY RESULTS

Lack of Hmgcr expression resulted in lethality, due to acute liver damage caused by rapid disruption of mitochondrial fatty acid β-oxidation and very high accumulation of long-chain (LC) acylcarnitines in both male and female mice. Gene expression and KO-related phenotype changes were not observed in other tissues. The progression to liver failure was driven by diminished peroxisome formation, which resulted in impaired mitochondrial and peroxisomal fatty acid metabolism, enhanced glucose utilization and whole-body hypoglycaemia.

CONCLUSION AND IMPLICATIONS

Our findings suggest that HMGCR is crucial for maintaining energy metabolism balance, and its activity is necessary for functional mitochondrial β-oxidation. Moreover, statin-induced adverse reactions might be rescued by the prevention of LC acylcarnitine accumulation.

Understanding Bartonella-Associated Infective Endocarditis: Examining Heart Valve and Vegetation Appearance and the Role of Neutrophilic Leukocytes

BACKGROUND

The endocardium and cardiac valves undergo severe impact during infective endocarditis (IE), and the formation of vegetation places IE patients at a heightened risk of embolic complications and mortality. The relevant literature indicates that 50% of IE cases exhibit structurally normal cardiac valves, with no preceding history of heart valve disease. Gram-positive cocci emerge as the predominant causative microorganisms in IE, while Gram-negative Bartonella spp., persisting in the endothelium, follow pathogenic pathways distinct from those of typical IE-causing agents. Employing clinical as well as advanced microbiological and molecular assays facilitated the identification of causative pathogens, and various morphological methods were applied to evaluate heart valve damage, shedding light on the role of neutrophilic leukocytes in host defense. In this research, the immunohistochemical analysis of neutrophilic leukocyte activation markers such as myeloperoxidase, neutrophil elastase, calprotectin, and histone H3, was performed. A distinct difference in the expression patterns of these markers was observed when comparing Bartonella spp.-caused and non-Bartonella spp.-caused IE. The markers exhibited significantly higher expression in non-Bartonella spp.-caused IE compared to Bartonella spp.-caused IE, and they were more prevalent in vegetation than in the valvular leaflets. Notably, the expression of these markers in all IE cases significantly differed from that in control samples. Furthermore, we advocated the use of 16S rRNA Next-Generation Sequencing on excised heart valves as an effective diagnostic tool for IE, particularly in cases where blood cultures yielded negative results. The compelling results achieved in this study regarding the enigmatic nature of Bartonella spp. IE's pathophysiology contribute significantly to our understanding of the peculiarities of inflammation and immune responses.

The Role of the p16 and p53 Tumor Suppressor Proteins and Viral HPV16 E6 and E7 Oncoproteins in the Assessment of Survival in Patients with Head and Neck Cancers Associated with Human Papillomavirus Infections

The role of HPV in the survival prognosis of patients with head and neck squamous cell carcinoma, especially patients with laryngeal squamous cell carcinoma (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC), is still somewhat ambiguous. The present study aimed to explore the significance of tumor suppressor proteins and HPV16 E6 and E7 oncoproteins in the assessment of survival in patients with oropharyngeal squamous cell carcinoma (OPSCC), LSCC, and HPSCC associated with high-risk (HR-) and low-risk (LR-) HPV infections. By utilizing molecular and immunohistochemical investigations of HNSCC samples and patient data, univariate and multivariate survival analyses were conducted. The presence of HPV DNA (LR- and HR-HPV) was associated with a better 5-year OS and DSS for OPSCC and LSCC. The IHC overexpression of HPV16 E6 protein and p16 protein was associated with better survival in the univariate (for OPSCC) and multivariate (OPSCC and HPSCC) survival analyses. The overexpression of p53 was associated with better survival in OPSCC. HPV infection plays a significant role in the tumorigenesis of HNSCC, and the immunohistochemical assessment of HPV16 E6 protein expression should be interpreted as a useful prognostic marker for OPSCC and HPSCC.

Size distribution and relationship of airborne SARS-CoV-2 RNA to indoor aerosol in hospital ward environments

Aerosol particles proved to play a key role in airborne transmission of SARS-CoV-2 viruses. Therefore, their size-fractionated collection and analysis is invaluable. However, aerosol sampling in COVID departments is not straightforward, especially in the sub-500-nm size range. In this study, particle number concentrations were measured with high temporal resolution using an optical particle counter, and several 8 h daytime sample sets were collected simultaneously on gelatin filters with cascade impactors in two different hospital wards during both alpha and delta variants of concern periods. Due to the large number (152) of size-fractionated samples, SARS-CoV-2 RNA copies could be statistically analyzed over a wide range of aerosol particle diameters (70-10 µm). Our results revealed that SARS-CoV-2 RNA is most likely to exist in particles with 0.5-4 µm aerodynamic diameter, but also in ultrafine particles. Correlation analysis of particulate matter (PM) and RNA copies highlighted the importance of indoor medical activity. It was found that the daily maximum increment of PM mass concentration correlated the most with the number concentration of SARS-CoV-2 RNA in the corresponding size fractions. Our results suggest that particle resuspension from surrounding surfaces is an important source of SARS-CoV-2 RNA present in the air of hospital rooms.

Healthy and Osteoarthritis-Affected Joints Facing the Cellular Crosstalk

Osteoarthritis (OA) is a chronic, progressive, severely debilitating, and multifactorial joint disease that is recognized as the most common type of arthritis. During the last decade, it shows an incremental global rise in prevalence and incidence. The interaction between etiologic factors that mediate joint degradation has been explored in numerous studies. However, the underlying processes that induce OA remain obscure, largely due to the variety and complexity of these mechanisms. During synovial joint dysfunction, the osteochondral unit undergoes cellular phenotypic and functional alterations. At the cellular level, the synovial membrane is influenced by cartilage and subchondral bone cleavage fragments and extracellular matrix (ECM) degradation products from apoptotic and necrotic cells. These "foreign bodies" serve as danger-associated molecular patterns (DAMPs) that trigger innate immunity, eliciting and sustaining low-grade inflammation in the synovium. In this review, we explore the cellular and molecular communication networks established between the major joint compartments-the synovial membrane, cartilage, and subchondral bone of normal and OA-affected joints.

Risk factors associated with mortality in the infective endocarditis patients requiring cardiac surgery: a study based on Latvian population

BACKGROUND

Increased life expectancy, developments in medicine and intracardiac devices, accessibility of cardiac surgery, decrease in the prevalence of rheumatic heart disease are changing infective endocarditis patient profile and thus risk factors for the adverse events. This single-center-based study covering the whole Latvian population aimed to assess the intrahospital and 3-year mortality of infective endocarditis patients who underwent cardiac surgery, as well as risk factors and laboratory indices predictive of adverse outcomes of the disease.

METHODS

Clinical profiles, data of laboratory and instrumental analyses, operation and intensive care unit records of cardiac surgery patients treated in Pauls Stradins Clinical University Hospital, Riga, Latvia, between 2015 and 2019 were analyzed.

RESULTS

We analyzed data from 242 episodes of surgically treated infective endocarditis in 233 patients. The median age of patients was 57.00 (45.00-68.00) years. The rate of intrahospital mortality was 11.16%. Risk factors associated with mortality in the univariate analyses were S. aureus infection (HR=2.27, 95% CI: 1.36-3.80; P=0.002) and systemic embolization of vegetations (HR=1.63, 95% CI: 1.00-2.64; P=0.048). Perivalvular complications (HR=1.98, 95% CI: 1.19-3.29; P=0.009) were found to be independently associated with mortality in multivariate analysis (HR=1.99, 95% CI: 1.05-3.78; P=0.035). One-year survival was 78.3%, whereas three-year -71.3%.

CONCLUSIONS

Intrahospital mortality of surgically treated IE patients was 11.2%; however, one- and three-year mortality was 21.7 and 28.7%, respectively. Perivalvular complications were independently associated with mortality. Laboratory indices were not predictive of adverse outcomes.

Prevalence, Cell Tropism, and Clinical Impact of Human Parvovirus Persistence in Adenomatous, Cancerous, Inflamed, and Healthy Intestinal Mucosa

Parvoviruses are single-stranded DNA viruses, infecting many animals from insects to humans. Human parvovirus B19 (B19V) causes erythema infectiosum, arthropathy, anemia, and fetal death, and human bocavirus (HBoV) 1 causes respiratory tract infections, while HBoV2-4 are enteric. Parvoviral genomes can persist in diverse non-permissive tissues after acute infection, but the host-cell tropism and the impact of their tissue persistence are poorly studied. We searched for parvoviral DNA in a total of 427 intestinal biopsy specimens, as paired disease-affected and healthy mucosa, obtained from 130 patients with malignancy, ulcerative colitis (UC), or adenomas, and in similar intestinal segments from 55 healthy subjects. Only three (1.6%) individuals exhibited intestinal HBoV DNA (one each of HBoV1, 2, and 3). Conversely, B19V DNA persisted frequently in the intestine, with 50, 47, 31, and 27% detection rates in the patients with malignancy, UC, or adenomas, and in the healthy subjects, respectively. Intra-individually, B19V DNA persisted significantly more often in the healthy intestinal segments than in the inflamed colons of UC patients. The highest loads of B19V DNA were seen in the ileum and colon specimens of two healthy individuals. With dual-RNAscope in situ hybridization and immunohistochemistry assays, we located the B19V persistence sites of these intestines in mucosal B cells of lymphoid follicles and vascular endothelial cells. Viral messenger RNA transcription remained, however, undetected. RNA sequencing (RNA-seq) identified 272 differentially expressed cellular genes between B19V DNA-positive and -negative healthy ileum biopsy specimens. Pathway enrichment analysis revealed that B19V persistence activated the intestinal cell viability and inhibited apoptosis. Lifelong B19V DNA persistence thus modulates host gene expression, which may lead to clinical outcomes.

Etiology, Risk Factors and Clinical Outcomes in Infective Endocarditis Patients Requiring Cardiac Surgery

Background: Infective endocarditis, which may be caused by various microbial agents, severely affects the innermost layer of the heart and often leads to poor clinical outcomes. The purpose of this study was to investigate the etiology, risk factors and short and long-term outcomes of infective endocarditis caused by various bacterial agents in patients requiring cardiac surgery. Methods: One hundred and forty-four patients aged 18 years or above with indications for cardiac surgery due to S. aureus, Streptococcus spp., E. faecalis or coagulase-negative staphylococci caused infective endocarditis were included in this study. Results: S. aureus, Streptococcus spp., E. faecalis and coagulase-negative staphylococci were the causative agents of infective endocarditis in 44 (30.6%), 35 (24.3%), 33 (22.9%) and 32 (22.2%) patients, respectively. The presence of bicuspid aortic valve was the most common predisposing factor confirmed in 19 (23.5%), whereas intravenous drug usage was the most common in 17 (11.8%) patients. No significant differences in intrahospital mortality due to infective endocarditis caused by various bacterial agents were found, however, the worsening of long-term prognosis of endocarditis caused by S. aureus when compared to E. faecalis was confirmed (p = 0.03). The presence of S. aureus was associated with significantly higher rates of embolic complications (p = 0.003). The presence of coagulase-negative staphylococci was associated with prosthetic valve endocarditis (p = 0.015) and perivalvular complications (p = 0.024). Conclusions: In contrast to E. faecalis, the presence of S. aureus determines the worsening of the long-term mortality from infective endocarditis. Perivalvular complications are associated with the presence of coagulase-negative staphylococci.

Low cardiac content of long-chain acylcarnitines in TMLHE knockout mice prevents ischaemia-reperfusion-induced mitochondrial and cardiac damage

Increased tissue content of long-chain acylcarnitines may induce mitochondrial and cardiac damage by stimulating ROS production. N⁶-trimethyllysine dioxygenase (TMLD) is the first enzyme in the carnitine/acylcarnitine biosynthesis pathway. Inactivation of the TMLHE gene (TMLHE KO) in mice is expected to limit long-chain acylcarnitine synthesis and thus induce a cardio- and mitochondria-protective phenotype. TMLHE gene deletion in male mice lowered acylcarnitine concentrations in blood and cardiac tissues by up to 85% and decreased fatty acid oxidation by 30% but did not affect muscle and heart function in mice. Metabolome profile analysis revealed increased levels of polyunsaturated fatty acids (PUFAs) and a global shift in fatty acid content from saturated to unsaturated lipids. In the risk area of ischemic hearts in TMLHE KO mouse, the OXPHOS-dependent respiration rate and OXPHOS coupling efficiency were fully preserved. Additionally, the decreased long-chain acylcarnitine synthesis rate in TMLHE KO mice prevented ischaemia-reperfusion-induced ROS production in cardiac mitochondria. This was associated with a 39% smaller infarct size in the TMLHE KO mice. The arrest of the acylcarnitine biosynthesis pathway in TMLHE KO mice prevents ischaemia-reperfusion-induced damage in cardiac mitochondria and decreases infarct size. These results confirm that the decreased accumulation of ROS-increasing fatty acid metabolism intermediates prevents mitochondrial and cardiac damage during ischaemia-reperfusion.

Identification of High-Risk Human Papillomavirus DNA, p16, and E6/E7 Oncoproteins in Laryngeal and Hypopharyngeal Squamous Cell Carcinomas

Human papillomavirus (HPV) was proven to play a significant role in cancer development in the oropharynx. However, its role in the development of laryngeal (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC) remains to be clarified. High-risk HPV (HR-HPV) viral proteins E6 and E7 are considered to be pertinent to HPV-related carcinogenesis. Hence, our aim was to estimate LSCC and HPSCC for HR-HPV DNA, p16, and E6/E7 oncoprotein status by using molecular virology and immunohistochemistry methods. The prevalence of HPV16 infection was 22/41 (53.7%) and 20/31 (64.5%) for LSCC and HPSCC, accordingly. The majority of HPV16+ tumor samples were stage III or IV. In most samples, the presence of either HPV16 E6 or HPV16 E7 viral protein in dysplastic or tumor cells was confirmed using immunohistochemistry. Our results suggest a high prevalence of HPV16 as a primary HR-HPV type in LSCC and HPSCC. The lack of HPV E6/E7 oncoproteins in some tumor samples may suggest either the absence of viral integration or the presence of other mechanisms of tumorigenesis. The utilization of p16 IHC as a surrogate marker of HR-HPV infection is impractical in LSCC and HPSCC.

Comparison of outcome between blood culture positive and negative infective endocarditis patients undergoing cardiac surgery

Background

Up to 30% or even more of all infective endocarditis (IE) cases are recognized as blood culture negative, meaning that the causative agent is left unidentified. The prompt diagnosis together with the identification of causative microorganism and targeted antibiotic treatment can significantly impact the prognosis of the disease and further patient’s health status. In some studies, blood culture negative endocarditis has been shown to be associated with delayed diagnosis, worse outcome and course of the disease, and a greater number of intra and postoperative complications.

Methods

We retrospectively analysed the medical records of all patients who underwent cardiac surgery for endocarditis between years 2016 and 2019. The aim of this study was to analyse short and long-term mortality and differences of laboratory, clinical and echocardiography parameters in patients with blood culture positive endocarditis (BCPE) and blood culture negative endocarditis (BCNE) and its possible impact on the clinical outcome.

Results

In our study population were 114 (55.1%) blood culture positive and 93 (44.9%) blood culture negative cases of infectious endocarditis. The most common pathogens in the blood culture positive IE group were S.aureus in 36 cases (31.6%), Streptococcus spp. in 27 (23.7%), E.faecalis in 24 (21.1%), and other microorganisms in 27 (23.7%). Embolic events were seen in 60 patients (28.9%). In univariate analyses, detection of microorganism, elevated levels of procalcitonin were found to be significantly associated with intrahospital death, however it did not reach statistical significance in multivariate analyses. Among microorganisms, S.aureus was significantly associated with intrahospital death in both univariate and multivariate analyses.

Conclusions

There are no statistically significant differences between groups of BCPE and BCNE in terms of intrahospital mortality, hospital and ICU stay or 3-year mortality.

There were higher levels of procalcitonin in BCPE group, however procalcitonin failed to show independent association with mortality in multivariate analysis.

The most common microorganism in the BCPE group was S.aureus. It was associated with independently higher intrahospital mortality when compared to other causative microorganisms.

Plasma levels of Th17-associated cytokines and selenium status in autoimmune thyroid diseases

Introduction

The contribution of Th17 cytokines to autoimmune thyroid disease (AITD) is generally accepted. However, the roles of Th17 cells in the initiation and progression of Hashimoto's thyroiditis (HT) and Graves' disease (GD) remain unclear. Selenium deficiency, along with genetic predisposition and environmental factors, may have a role in thyroid autoimmunity.

Aim

We aimed to assess (1) the Th17 immune response by measuring plasma levels of Th17‐ and Treg‐associated cytokines and (2) the selenium status in treatment‐naïve Latvian patients with newly diagnosed GD or HT.

Methods

Eleven GD patients, 41 HT patients, and 26 healthy subjects were recruited for this study. Plasma levels of IL‐17a, IL‐22, IL‐23, IL‐6, and IL‐10 were detected by xMAP technology, while selenium was detected fluorometrically.

Results and Conclusions

No significant differences in IL‐17a, IL‐22, IL‐23, IL‐6, or IL‐10 levels were found among the HT patients, GD patients, and controls. In the HT patients, IL‐17a levels were positively correlated with IL‐22, IL‐23, IL‐6, and IL‐10, while IL‐22 was correlated with IL‐6, IL‐23, and IL‐10. In the GD patients, IL‐17a levels were positively correlated with IL‐22, IL‐23, and IL‐10; IL‐22 was positively correlated with IL‐23, IL‐6, and IL‐10; FT3 was positively correlated with IL‐17a, IL‐23, and IL‐10; and FT4 was positively correlated with IL‐17a and IL‐10 levels. Plasma selenium levels were negatively correlated with antithyroid peroxidase antibody titers in the HT patients. Although no difference in selenium levels was observed between the AITD patients and controls, the selenium status of the Latvian patients with GD or HT was at a suboptimal level.

Analysis of the occurrence and distribution of primary and recurrent basal cell carcinoma of head and neck coupled to the assessment of tumor microenvironment and Sonic hedgehog signaling

Often, basal cell carcinoma (BCC) displays local aggressiveness, and when developed in the head and neck presents with deep tissue invasion and recurrence. Previous studies have pointed out the necessity of systematic assessment of primary and recurrent BCC based on a better understanding of the biology and function of its microenvironment. Although hedgehog-dependent tumor cells signaling to the underlying stroma, and vice versa, have been demonstrated to be implicated in the pathogenesis of BCC, little is known about peculiarities of the tumor microenvironment and the above-mentioned signaling in the head and neck. The occurrence and distribution of 79 primary and recurrent BCCs developed in the head and neck region were estimated. The data were coupled with the immunohistochemical assessment of type IV collagen, laminin, alpha-smooth muscle actin (α-SMA), and Sonic hedgehog (Shh). The frequency of the mixed BCCs and the predominance of the nose and cheek region affection by primary and recurrent tumors were demonstrated. Furthermore, the increase of peritumoral and entire stromal α-SMA immunoreactivity in the mixed recurrent BCC was confirmed using statistics. We found the increase of strong levels of Shh immunoexpression in the aggressive variants of BCC - infiltrative, mixed, and micronodular. Surprisingly, we confirmed the upregulation of Shh paralleled by the downregulation of α-SMA immunoexpression in the superficial subtype of the tumor. Our results suggest the necessity of further studies assessing the nature of the tumor along with the peculiarities of signaling in BCCs of head and neck.

Dickkopf-related protein 1 expression in bone marrow of multiple myeloma patients: correlation with bone disease and plasma cell malignancy type

BACKGROUND

Previous studies have pointed out the role of dickkopf-related protein 1 (DKK 1) - Wnt inhibitor, which is essential for osteoblast functioning, in the development of osteolytic lesions in multiple myeloma (MM).

AIM

To assess the DKK 1 expression displayed by myeloma cells in bone marrow trephine biopsies of patients with and without osteolytic lesions, and in different malignancy grades of the disease.

METHODS

The expression level of DKK 1 was assessed immunohistochemically in bone marrow of 49 MM patients presented with and without osteolytic lesions (the 1^st and the 2^nd group, respectively).

RESULTS

Levels of weak, moderate, and strong DKK 1 expression were distributed - as 43.33, 27.78 and 25.56%, and 63.91, 18.80, and 1.50%, respectively when evaluating the samples obtained from the 1^st and the 2^nd group. Statistically significant differences were found when the levels of DKK 1 expression in the 1^st and the 2^nd group were compared (χ² = 51; df = 3; p < 0.001).

CONCLUSIONS

DKK 1 contributes to the development of osteolytic lesions in MM. The present study provides morphological evidence that inhibition in Wnt signaling may lead to bone damage observed in the advanced stage of the disease.

Survival analysis of oropharyngeal squamous cell carcinoma patients linked to histopathology, disease stage, tumor stage, risk factors, and received therapy

BACKGROUND

Survival of oropharyngeal squamous cell carcinoma (OSCC) patients depends on the risk and environmental factors, tumor biology, achievements in diagnostics and treatment approaches.

AIM

To perform a survival analysis of the patients with OSCC treated over a 10-year period in a single hospital in Latvia linking these data to histopathological findings, risk factors and received therapy.

MATERIALS AND METHODS

The main outcome measures were overall and disease-specific survival (OS and DS) along with histopathology analysis.

RESULTS

Kaplan - Meier survival analysis showed better survival for females, younger patients lacking bad habits, operated and received radiotherapy, with lower T grade and disease stage. Cox regression showed diminished early death risk in patients with lower T grade, no regional metastases (N0) and bad habits, operated and received radiotherapy. A vast majority of tumors were localized in palatine tonsils and the base of the tongue. The localization did not correlate with mean survival time/survival. Lower OS (p = 0.03) and DS (p = 0.026) were estimated for patients with pharyngeal wall and tonsillar involvement compared to tumors localized in the soft palate. A histological variant of tumor seemed irrelevant estimating OS and DS, whereas therapeutic modalities significantly affected survival.

CONCLUSIONS

OSCC patients with lower T grade, N0 status, lacking bad habits, and surgically treated had better survival.

Upregulated tissue expression of T helper (Th) 17 pathogenic interleukin (IL)-23 and IL-1β in Hashimoto's thyroiditis but not in Graves' disease

T helper (Th) 17 cells and interleukin (IL)-17 play a significant role in the pathogenesis of autoimmune thyroid disease (AITD). However, it has recently become clear that Th17 cells are more heterogeneous and exhibit two different phenotypes, whereas IL-23 and IL-1β are crucial for the generation of pathogenic Th17 lymphocytes. We aimed to investigate the association between IL-17 and Th17-promoting cytokines in AITD by studying the immunoexpression patterns of IL-17, IL-23, and IL-1β in thyroid tissue. Following thyroidectomy, 29 patients with AITD (21 cases of Hashimoto's thyroiditis (HT) and 8 cases of Graves' disease (GD)) and 18 patients with colloid goiter, as controls, were enrolled in this study, and immunohistochemistry was performed. The expression level of IL-17 in thyrocytes was significantly higher in HT and GD patients than in colloid goiter patients. Immunopositivity for both IL-23 and IL-1β was significantly increased in HT patients compared to GD and colloid goiter patients. However, no difference was found between IL-23 or IL-1β expression in patients with GD and colloid goiter. A positive correlation between IL-17 and IL-23 as well as IL-17 and IL-1β expression was observed in HT patients (r = 0.574, p = 0.007 and r = 0.461, p = 0.036, respectively). In the GD group, IL-17 was positively correlated with IL-1β (r = 0.817, p = 0.013) but not with IL-23 expression. We found increased IL-23 and IL-1β expression in the HT group but not in the GD group. Furthermore, both interleukins were correlated with IL-17 immunopositivity in thyroid tissue, suggesting that pathogenic Th17-promoting cytokines may play a role in HT pathogenesis.

Heterogeneity of tissue IL-17 and tight junction proteins expression demonstrated in patients with autoimmune thyroid diseases

Th17 cells together with their hallmark cytokine interleukin (IL)-17 were identified as crucial contributing factors in the pathogenesis of thyroid autoimmunity. The cytokine-regulated tight junction (Tj) disruption is thought to be essential in the initiation and/or development of several diseases. Still, the role of IL-17 maintaining Tj integrity in autoimmune thyroid diseases (AITDs) has not yet been evaluated. We aimed to investigate integrity of the thyroid follicle by studying immunoexpression of cellular Tj - zonula occludens (ZO)-1 and claudin-1 proteins coupled to IL-17A and CD68 detection in AITD patients compared with controls.Thirty-five adult patients undergoing thyroidectomy and presenting 18 cases of Hashimoto thyroiditis (HT), 7 of Graves' disease (GD) as well as 10 subjects of colloid goiter without autoimmune component served as controls were enrolled in this study. An immunohistochemical analysis including IL-17A, ZO-1, claudin-1, and CD68 detection was performed in each case. The correlation of IL-17A with Tj and CD68 in patients with AITD was also analyzed.Apart from inflammatory cells, we evidenced a stronger expression level of IL17A in the thyroid follicular cells in HT patients when compared with GD or colloid goiter. A significant reduction of ZO-1 immunoreactivity was observed in the thyrocytes in HT patients, whereas no significant differences were found in claudin-1 expression in HT and GD compared with colloid goiter patients. A significantly higher number of thyroid follicles with CD68-positive cells was found in HT patients than that in patients with GD or colloid goiter. In HT patients, the expression of IL-17A in the follicular cells was positively correlated with CD68 immunopositivity, whereas no association with claudin-1 or ZO-1 expression was found. GD patients did not reveal any significant correlation of IL-17A with Tj and CD68.Strong overexpression of IL-17A observed in the thyroid epithelial cells is associated with the presence of intrafollicular CD68-positive cells in HT patients. We evidenced the changes in molecules of thyrocyte junctional complexes highlighting impairment of the thyroid follicle integrity in HT, but no association with IL-17A was found.

Structural and Ultrastructural Alterations in Human Olfactory Pathways and Possible Associations with Herpesvirus 6 Infection

Structural and ultrastructural alterations in human olfactory pathways and putative associations with human herpesvirus 6 (HHV-6) infection were studied. The olfactory bulb/tract samples from 20 subjects with an unspecified encephalopathy determined by pathomorphological examination of the brain autopsy, 17 healthy age-matched and 16 younger controls were used. HHV-6 DNA was detected in 60, 29, and 19% of cases in these groups, respectively. In the whole encephalopathy group, significantly more HHV-6 positive neurons and oligodendrocytes were found in the gray matter, whereas, significantly more HHV-6 positive astrocytes, oligodendrocytes, microglia/macrophages and endothelial cells were found in the white matter. Additionally, significantly more HHV-6 positive astrocytes and, in particular, oligodendrocytes were found in the white matter when compared to the gray matter. Furthermore, when only HHV-6 PCR⁺ encephalopathy cases were studied, we observed similar but stronger associations between HHV-6 positive oligodendrocytes and CD68 positive cells in the white matter. Cellular alterations were additionally evidenced by anti-S100 immunostaining, demonstrating a significantly higher number of S100 positive cells in the gray matter of the whole encephalopathy group when compared to the young controls, and in the white matter when compared to both control groups. In spite the decreased S100 expression in the PCR⁺ encephalopathy group when compared to PCR^- cases and controls, groups demonstrated significantly higher number of S100 positive cells in the white compared to the gray matter. Ultrastructural changes confirming the damage of myelin included irregularity of membranes and ballooning of paranodal loops. This study shows that among the cellular targets of the nervous system, HHV-6 most severely affects oligodendrocytes and the myelin made by them.

Biomechanical and morphological peculiarities of the rectum in patients with obstructed defecation syndrome

The morphological and biomechanical peculiarities of the rectum observed in obstructed defecation syndrome (ODS) are not completely understood. The biomechanical properties and morphological features of the rectum in patients with ODS in correlation with the status of the enteric nervous system (ENS) were evaluated. Uniaxial tensile tests on the rectum samples of patients with ODS and controls were performed; collagenous constituents were assessed by Reticulin and Masson's trichrome stainings; the expressions of α-smooth muscle actin (α-SMA), S100 and CD117 labeling of interstitial cells of Cajal (ICCs) were investigated by immunohistochemistry. In both groups, the ultimate stress in the posterior rectal wall was statistically significantly higher compared to the anterior one. The ultimate strain was higher in ODS compared to controls. The tangential modulus of elasticity was significantly higher in the control group than in the ODS one, both in the anterior and posterior walls. A significantly higher density of collagen demonstrated throughout the wall was evidenced in controls compared to ODS. The mucosal muscular compartment was significantly thicker but more disorganized in the patients group. The enteric S100-positive glial cells were significantly reduced in number in the anterior wall, but elevated in the posterior wall of the rectum in ODS simultaneously demonstrating the higher numbers of ICCs within the entire muscular layer and myenteric. The biomechanical and morphological results show that the rectal wall in patients with ODS is more deformable and less rigid compared to controls. The results of biomechanical properties and morphological changes in the human rectum are essential when choosing the method of ODS treatment.

Association of active human herpesvirus-6 (HHV-6) infection with autoimmune thyroid gland diseases

OBJECTIVES

Viral infections frequently have been cited as important environmental factors implicated in the onset of autoimmune thyroiditis (AIT). The aim of this study was to determine the involvement of HHV-6 infection in the development of autoimmune thyroiditis.

METHODS

This study included 45 patients (42 female and 3 male; median age 47.00 IQR 38.50-57.00) with histologically, laboratory, and clinically confirmed autoimmune thyroiditis, as well as 30 autopsied subjects (26 female and 4 male; median age 58.50, IQR 51.50-67.00) without thyroid pathologies and 30 healthy blood donors (25 female and 5 male; median age 33.50, IQR 27.75-44.25) as controls. Results were obtained by applying molecular virology and immunohistochemistry techniques.

RESULTS

The presence of persistent HHV-6 infection in AIT patients was significantly higher (p 0.0058) than in the control group (44/45 (98%) vs. 23/30 (77%), respectively). Also, a significantly higher frequency of HHV-6 activation marker (U79/80 mRNA) was found in patients' thyroid gland tissue samples with AIT in comparison with the control group (18/44 (41%) vs. 1/17 (6%), respectively; p 0.0118). The median HHV-6 load was found to be higher in patients with active viral infection than in patients without it (2147, IQR 971-4188 vs. 551, IQR 145-1589 copies/1×10⁶ cells; p 0.003). The presence of HHV-6 antigen expression was demonstrated in intrafollicular cellular clusters and immunohistochemistry indicated thyrocytes in the follicle wall.

CONCLUSIONS

These findings provide evidence of strong HHV-6 infection association with AIT development.

Detection frequency of human herpesviruses-6A, -6B, and -7 genomic sequences in central nervous system DNA samples from post-mortem individuals with unspecified encephalopathy

In this autopsy-based study, human herpesvirus-6 (HHV-6) and -7 (HHV-7) genomic sequence frequency, HHV-6 variants, HHV-6 load and the expression of HHV-6 antigens in brain samples from the individuals, with and without unspecified encephalopathy (controls), using nested and real-time polymerase chain reactions, restriction endonuclease, and immunohistochemical analysis were examined. GraphPad Prism 6.0 Mann-Whitney nonparametric and chi-square test and Fisher's exact test were used for statistical analysis. The encephalopathy diagnoses were shown by magnetic resonance imaging made during their lifetime and macro- and microscopically studied autopsy tissue materials. Widespread HHV-6 and/or HHV-7 positivity was detected in the brain tissue of various individuals with encephalopathy, as well as in controls (51/57, 89.4 % and 35/51, 68.6 %, respectively; p = 0.009). Significantly higher detection frequency of single HHV-6 and concurrent HHV-6 + HHV-7 DNA was found in pia mater meninges, frontal lobe, temporal lobe, and olfactory tract DNAs in individuals with encephalopathy compared to the control group. HHV-6 load and higher frequency of the viral load >10 copies/10(6) cells significantly differed in samples from individuals with and without encephalopathy. The expression of HHV-6 antigens was revealed in different neural cell types with strong predominance in the encephalopathy group. In all HHV-6-positive autopsy samples of individuals with and without encephalopathy, HHV-6B was revealed. Significantly higher detection frequency of beta-herpesvirus DNA, more often detected HHV-6 load >10 copies/10(6) cells, as well as the expression of HHV-6 antigens in different brain tissue samples from individuals with encephalopathy in comparison with control group indicate on potential involvement of these viruses in encephalopathy development.

Effect of infliximab induction therapy on secondary systemic amyloidosis associated with Crohn's disease: case report and review of the literature

Secondary systemic (AA) amyloidosis is reported as a serious complication that occurs in long-standing Crohn's disease (CD), with an incidence of 0.3-10.9%. Various therapeutic approaches using medicines and elemental diet have been recommended, but still there are no established standards of treatment for secondary systemic amyloidosis in CD. Only a few studies have shown the role of TNFα ihibitors in the treatment of AA amyloidosis over a long term period. We report the case of a 24-year-old male with CD complicated by AA amyloidosis with renal and gastrointestinal tract involvement treated with infliximab as induction therapy. Intestinal AA amyloidosis progression occurred at the same time with the development of CD as an early complication, whereas duration of CD prior to the diagnosis of renal AA amyloidosis was 6 years. Infliximab therapy (3 infusions) caused a significant decrease of serum amyloid A protein (by 97.9%), C-reactive protein (by 70%), improvement of disease activity index, and CD caused clinical symptoms. At the same time gradual progression of the renal damage (reduction of renal function) was not affected by the treatment. Direct efficacy of infliximab infusions on serum amyloid protein level may support the hypothesis of TNFα induced reduction on the progression of AA amyloidosis described in previous study reports. Targeted histological analysis of tissue biopsy is crucial to clarify the presence of AA amyloidosis in CD induced multiorgan damage cases.

Protective reactivity and alteration of the brain tissue in alcoholics evidenced by SOD1, MMP9 immunohistochemistry, and electron microscopy

Alcohol and its associated oxidative stress is one of the widespread contributors to the brain damage. Matrix metalloproteinases, which are extensively analyzed in brain pathology studies, are not sufficiently investigated in chronic alcohol consumption. This study evaluated regional brain damage caused by oxidative stress. Contribution of metalloproteinase-9 to this affection was evidenced in alcoholic subjects and correlated with ultrastructural changes. The authors found correlation between neuronal expression patterns of superoxide dismutase-1 and metalloproteinase-9 in nigral (r = 0.532, p < 0.001), striatal (r = 0.327, p < 0.001), and cortical (r = 0.306, p < 0.001) regions, and a significant decrease of nigral superoxide dismutase-1 median values accompanied by severe myelin damage.

The outcome of the movement disorder in methcathinone abusers: clinical, MRI and manganesemia changes, and neuropathology

BACKGROUND AND PURPOSE

There is limited knowledge regarding the long-term outcome of the methcathinone/manganese-induced movement disorder. Our purpose was to define prognosis in intravenous methcathinone abusers affected by this distinctive disorder attributed to manganese (Mn) toxicity. Also, neuropathology from a globus pallidus region biopsy from a former user is reported.

METHODS

Eighteen methcathinone abusers were categorized as active (five), discontinued (four) or former (nine) users. They were reassessed after a median of 32.5 months (range 3.4-59.6) clinically, on rating scales, and with MRI and blood Mn levels. The biopsy was examined ultrastructurally.

RESULTS

Overall the group showed a slight tendency to deterioration at follow-up on clinical assessment of motor functioning, especially the active users. No significant change occurred on parkinsonian rating scale reassessment. Significant reduction in Mn levels occurred in former users, and decreased T1-weighted hyperintensity on basal ganglia MRI occurred in 3 of 4 former and 2 of 3 discontinued users, despite lack of clinical improvement. The biopsy consisted of white matter showing decompacted myelin sheaths and frequent abnormalities of mitochondria.

CONCLUSIONS

No improvement in this Mn-induced movement disorder occurs after cessation of methcathinone abuse despite improvement of Mn blood levels and/or MRI abnormalities. Ultrastructural abnormalities in a former user confirm structural damage to white matter is associated with the disorder. Methcathinone/Mn toxicity is an important, disabling and permanent medical sequel of intravenous drug abuse in the former Soviet Union.

The proper delivery pressure for cardioplegic solution in neonatal cardiac surgery - an investigation of biomechanical and structural properties of neonatal and adult coronary arteries

When cardioplegic solution is injected into coronary arteries with a pump in order to ensure myocardial protection, it is necessary to determine the correct delivery pressure to avoid damage of the heart. Biomechanical and structural properties of the neonatal coronary artery wall should be taken into account when determining the delivery pressure. We investigated twelve coronary artery specimens without cardiac pathology retrieved from autopsies of neonates 9.3 ± 9.7 days old and compared them to adult specimens with no detected atherosclerosis. There was a rapid increase in the strain until the inner pressure reached 80 - 100 mmHg, whilst the increase of stress in the wall of the neonatal coronary arteries was less rapid. When the pressure exceeded 100 mmHg, the increase in the strain slowed down, whilst the wall stress and modulus of elasticity began to increase rapidly. Morphologic examination of tensile properties revealed prominent affection of the vascular wall of the neonates, with accentuated redistribution (loosening) of medial myocytes and the adventitial vasa vasorum. Collectively, a raised inner pressure applied to cardioplegic solution injected into the coronary artery of a neonate may increase the risk of structural damage to the vascular wall.

Alcoholism and cellular vulnerability in different brain regions

Alcohol-induced damage causes dysfunction of selected brain regions. Multidisciplinary studies have provided an extensive description of changes observed in neurons and glia following alcohol consumption. In this study the authors have elucidated preferential cellular vulnerability in three different brain regions. Autopsy material of the prefrontal cortex, striatum, and substantia nigra obtained from the brain tissue of alcoholic subjects was used in this study. We found that dendritic tree and astroglial damage is irreversible, while neuronal somata and most axons do not display irreversible changes.

Kynurenine and neopterin in chronic glomerulonephritis

The results of our clinical observations of 102 patients with chronic glomerulonephritis with normal renal function have shown that hyperkynureninemia in 22.5% of patients develops in cases of pyridoxal-5-phosphate deficiency (hyperkynureninemia after peroral L-tryptophan load), but in 14.8% of patients through the stimulation of the cellular immune system (hyperkynureninemia at fasting state, increase of serum neopterin concentration). In all 20 patients with chronic renal failure hyperkynureninemia develops due to decreased renal function (increased serum kynurenine, neopterin and creatinine concentrations). Therefore, L-tryptophan peroral loading test with the determination of serum concentration of kynurenine before and at 3rd hour after the load, as well as the detection of serum concentration of neopterin and creatinine are helpful for the differentiation of following pathologies in patients with chronic glomerulonephritis: pyridoxal-5-phosphate deficiency, cellular immune stimulation and chronic renal failure.

Demonstration of collagen type VI and alpha-smooth muscle actin in renal fibrotic injury in man

BACKGROUND

Overproduction of collagenous fibres types I and III is a common finding of fibrotic injury. Collagen type VI is generally associated with type I. Appearance of fibroblasts expressing alpha-smooth muscle actin (ASMA) and their role in fibrogenesis has been partly defined. However, correlation between renal fibroblasts and accumulation of microfibrillar collagen type VI, as well as its exact distribution, is not fully delineated. This study was undertaken to investigate these issues using a complex morphological approach.

METHODS

Morphological examination included immunohistochemical detection of the collagen type VI and ASMA, relying on a streptavidin-biotin-peroxidase-based technique, and electron microscopy.

RESULTS

Collagen type VI was strongly expressed in areas of fibrotic injury, although mild expression was always revealed in renal interstitium. Glomerular immunoreactivity with the anti-collagen type VI antibody was almost nil excepting cases of diabetic glomerulosclerosis and amyloid nephrosis. Glomerular nodules in cases of diabetes displayed intense reactivity. Mesangial, as well as discontinuous peripheral deposition of collagen along the glomerular basement membrane, was noticed in case of amyloidosis. Ultrastructurally, cross-banded collagen microfibrils were found in renal interstitium in close association with the fibroblast membrane. Moreover, fibrillar elements revealing tubular structure and fine filamentous material were observed between cross-banded microfibrils. Some of fibroblasts exhibited bundles of microfilaments in their cytoplasm. An increased number of ASMA-positive cells was detected in fibrotic interstitium. An intense concentric network made up of actin-bearing cells surrounded glomerular capillaries in the case of crescentic glomerular lesions.

CONCLUSIONS

Markedly increased deposition of collagen type VI takes place in renal fibrotic lesions. Simultaneously, interstitial fibrotic areas appeared to contain a great number of fibroblasts sharing morphological characteristics of classic fibroblasts and smooth muscle cells. Detailed examination of coexistence of these two interstitial phenomena should further clarify the cellular mechanisms involved in renal interstitial fibrosis.

A quantitative immunohistochemical study of the expression of mesangial alpha-smooth muscle actin and the proliferation marker Ki-67 in glomerulonephritis in man

Using a specific marker 1A4 (DAKO), a quantitative evaluation of alpha-smooth muscle actin (ASMA) in glomeruli has been performed on human renal biopsies from patients suffering from acute, postinfectious, endocapillary glomerulonephritis (GN; 9 biopsies), IgA nephropathy (11 biopsies) and membranoproliferative GN (11 biopsies) and appropriate controls expressing a very weak ASMA reactivity. A significantly increased expression was found in all categories of GN. The glomeruli from IgA nephropathy showed variation of ASMA expression (range 0.1-27.7%) and a pattern of ASMA staining that was mesangial, global and diffuse. This pattern was also seen in cases of IgA nephropathy with focal, segmental, proliferative GN. In all biopsies, the glomerular cell number and proliferation index was determined. All the categories of GN showed significantly increased glomerular cellularity and proliferation index. Among the three types of GN, the glomerular cellularity and proliferation was lowest in IgA nephropathy. The mean number of Ki-67-positive intraglomerular nuclei and the proliferation index were both significantly correlated with the mean number of glomerular cell nuclei. Morphometric estimates demonstrate increased ASMA expression in types of GN with different prognosis. This finding and the lack of correlation with proliferation markers together indicate that the role of ASMA in GN is complex. This method of ASMA estimation may be useful in further studies of its role in disease activity and prognosis.