Autoimmunity Against Surfactant Protein B Is Associated with Pneumonitis During Checkpoint Blockade

RATIONALE

Immune checkpoint inhibitor-related pneumonitis is a serious autoimmune event affecting up to 20% of patients with non-small cell lung cancer, yet the factors underpinning its development in some patients and not others are poorly understood.

OBJECTIVES

To investigate the role of autoantibodies and autoreactive T cells against surfactant-related proteins in the development of pneumonitis.

METHODS

The study cohort consisted of non-small cell lung cancer patients who gave blood samples before and during immune checkpoint inhibitor treatment. Serum was used for proteomics analyses and to detect autoantibodies present during pneumonitis. T cell stimulation assays and single-cell RNA sequencing were performed to investigate the specificity and functionality of peripheral autoreactive T cells. The findings were confirmed in a validation cohort comprising patients with non-small cell lung cancer and patients with melanoma.

MEASUREMENTS AND MAIN RESULTS

Across both cohorts, patients who developed pneumonitis had higher pre-treatment levels of immunoglobulin G autoantibodies targeting surfactant protein-B. At the onset of pneumonitis, these patients also exhibited higher frequencies of CD4+ interferon-gamma-positive surfactant protein B-specific T cells, and expanding T cell clonotypes recognizing this protein, accompanied by a pro-inflammatory serum proteomic profile.

CONCLUSIONS

Our data suggest that the co-occurrence of surfactant protein-B-specific immunoglobulin G autoantibodies and CD4+ T cells is associated with the development of pneumonitis during ICI therapy. Pre-treatment levels of these antibodies may represent a potential biomarker for elevated risk of developing pneumonitis and on-treatment levels may provide a diagnostic aid. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Pulmonary Surfactant Proteins Are Inhibited by Immunoglobulin A Autoantibodies in Severe COVID-19

Rationale: Coronavirus disease 2019 (COVID-19) can lead to acute respiratory distress syndrome with fatal outcomes. Evidence suggests that dysregulated immune responses, including autoimmunity, are key pathogenic factors. Objectives: To assess whether IgA autoantibodies target lung-specific proteins and contribute to disease severity. Methods: We collected 147 blood, 9 lung tissue, and 36 BAL fluid samples from three tertiary hospitals in Switzerland and one in Germany. Severe COVID-19 was defined by the need to administer oxygen. We investigated the presence of IgA autoantibodies and their effects on pulmonary surfactant in COVID-19 using the following methods: immunofluorescence on tissue samples, immunoprecipitations followed by mass spectrometry on BAL fluid samples, enzyme-linked immunosorbent assays on blood samples, and surface tension measurements with medical surfactant. Measurements and Main Results: IgA autoantibodies targeting pulmonary surfactant proteins B and C were elevated in patients with severe COVID-19 but not in patients with influenza or bacterial pneumonia. Notably, pulmonary surfactant failed to reduce surface tension after incubation with either plasma or purified IgA from patients with severe COVID-19. Conclusions: Our data suggest that patients with severe COVID-19 harbor IgA autoantibodies against pulmonary surfactant proteins B and C and that these autoantibodies block the function of lung surfactant, potentially contributing to alveolar collapse and poor oxygenation.

Frequency and Genomic Aspects of Intrinsic Resistance to Vismodegib in Locally Advanced Basal Cell Carcinoma

PURPOSE

Vismodegib is approved for the treatment of locally advanced basal cell carcinoma (laBCC), but some cases demonstrate intrinsic resistance (IR) to the drug. We sought to assess the frequency of IR to vismodegib in laBCC and its underlying genomic mechanisms.

EXPERIMENTAL DESIGN

Response to vismodegib was evaluated in a cohort of 148 laBCC patients. Comprehensive genomic and transcriptomic profiling was performed in a subset of five intrinsically resistant BCC (IR-BCC).

RESULTS

We identified that IR-BCC represents 6.1% of laBCC in the studied cohort. Prior treatment with chemotherapy was associated with IR. Genetic events that were previously associated with acquired resistance (AR) in BCC or medulloblastoma were observed in three out of five IR-BCC. However, IR-BCCs were distinct by highly rearranged polyploid genomes. Functional analyses identified hyperactivation of the HIPPO-YAP and WNT pathways at RNA and protein levels in IR-BCC. In vitro assay on the BCC cell line further confirmed that YAP1 overexpression increases the cell proliferation rate.

CONCLUSIONS

IR to vismodegib is a rare event in laBCC. IR-BCCs frequently harbor resistance mutations in the Hh pathway, but also are characterized by hyperactivation of the HIPPO-YAP and WNT pathways.

Early disappearance of tumor antigen-reactive T cells from peripheral blood correlates with superior clinical outcomes in melanoma under anti-PD-1 therapy

Background

Anti-programmed cell death protein 1 (PD-1) antibodies are now routinely administered for metastatic melanoma and for increasing numbers of other cancers, but still only a fraction of patients respond. Better understanding of the modes of action and predictive biomarkers for clinical outcome is urgently required. Cancer rejection is mostly T cell-mediated. We previously showed that the presence of NY-ESO-1-reactive and/or Melan-A-reactive T cells in the blood correlated with prolonged overall survival (OS) of patients with melanoma with a heterogeneous treatment background. Here, we investigated whether such reactive T cells can also be informative for clinical outcomes in metastatic melanoma under PD-1 immune-checkpoint blockade (ICB).

Methods

Peripheral blood T cell stimulation by NY-ESO-1 and Melan-A overlapping peptide libraries was assessed before and during ICB in two independent cohorts of a total of 111 patients with stage IV melanoma. In certain cases, tumor-infiltrating lymphocytes could also be assessed for such responses. These were characterized using intracellular cytokine staining for interferon gamma (IFN-γ), tumor negrosis factor (TNF) and CD107a. Digital pathology analysis was performed to quantify NY-ESO-1 and Melan-A expression by tumors. Endpoints were OS and progression-free survival (PFS).

Results

The initial presence in the circulation of NY-ESO-1- or Melan-A-reactive T cells which became no longer detectable during ICB correlated with validated, prolonged PFS (HR:0.1; p>0.0001) and OS (HR:0.2; p=0.021). An evaluation of melanoma tissue from selected cases suggested a correlation between tumor-resident NY-ESO-1- and Melan-A-reactive T cells and disease control, supporting the notion of a therapy-associated sequestration of cells from the periphery to the tumor predominantly in those patients benefitting from ICB.

Conclusions

Our findings suggest a PD-1 blockade-dependent infiltration of melanoma-reactive T cells from the periphery into the tumor and imply that this seminally contributes to effective treatment.

CD155 on Tumor Cells Drives Resistance to Immunotherapy by Inducing the Degradation of the Activating Receptor CD226 in CD8+ T Cells

The activating receptor CD226 is expressed on lymphocytes, monocytes, and platelets and promotes anti-tumor immunity in pre-clinical models. Here, we examined the role of CD226 in the function of tumor-infiltrating lymphocytes (TILs) and resistance to immunotherapy. In murine tumors, a large proportion of CD8⁺ TILs had decreased surface expression of CD226 and exhibited features of dysfunction, whereas CD226^hi TILs were highly functional. This correlation was seen also in TILs isolated from HNSCC patients. Mutation of CD226 at tyrosine 319 (Y319) led to increased CD226 surface expression, enhanced anti-tumor immunity and improved efficacy of immune checkpoint blockade (ICB). Mechanistically, tumor-derived CD155, the ligand for CD226, initiated phosphorylation of Y319 by Src kinases, thereby enabling ubiquitination of CD226 by CBL-B, internalization, and proteasomal degradation. In pre-treatment samples from melanoma patients, CD226⁺CD8⁺ T cells correlated with improved progression-free survival following ICB. Our findings argue for the development of therapies aimed at maintaining the expression of CD226.

Expression of AXL receptor tyrosine kinase relates to monocyte dysfunction and severity of cirrhosis

Infectious complications in patients with cirrhosis frequently initiate episodes of decompensation and substantially contribute to the high mortality. Mechanisms of the underlying immuneparesis remain underexplored. TAM receptors (TYRO3/AXL/MERTK) are important inhibitors of innate immune responses. To understand the pathophysiology of immuneparesis in cirrhosis, we detailed TAM receptor expression in relation to monocyte function and disease severity prior to the onset of acute decompensation. TNF-α/IL-6 responses to lipopolysaccharide were attenuated in monocytes from patients with cirrhosis (n = 96) compared with controls (n = 27) and decreased in parallel with disease severity. Concurrently, an AXL-expressing (AXL⁺) monocyte population expanded. AXL⁺ cells (CD14⁺CD16^highHLA-DR^high) were characterised by attenuated TNF-α/IL-6 responses and T cell activation but enhanced efferocytosis and preserved phagocytosis of Escherichia coli Their expansion correlated with disease severity, complications, infection, and 1-yr mortality. AXL⁺ monocytes were generated in response to microbial products and efferocytosis in vitro. AXL kinase inhibition and down-regulation reversed attenuated monocyte inflammatory responses in cirrhosis ex vivo. AXL may thus serve as prognostic marker and deserves evaluation as immunotherapeutic target in cirrhosis.

CD14+ CD15- HLA-DR- myeloid-derived suppressor cells impair antimicrobial responses in patients with acute-on-chronic liver failure

OBJECTIVE

Immune paresis in patients with acute-on-chronic liver failure (ACLF) accounts for infection susceptibility and increased mortality. Immunosuppressive mononuclear CD14⁺HLA-DR^- myeloid-derived suppressor cells (M-MDSCs) have recently been identified to quell antimicrobial responses in immune-mediated diseases. We sought to delineate the function and derivation of M-MDSC in patients with ACLF, and explore potential targets to augment antimicrobial responses.

DESIGN

Patients with ACLF (n=41) were compared with healthy subjects (n=25) and patients with cirrhosis (n=22) or acute liver failure (n=30). CD14⁺CD15^-CD11b⁺HLA-DR^- cells were identified as per definition of M-MDSC and detailed immunophenotypic analyses were performed. Suppression of T cell activation was assessed by mixed lymphocyte reaction. Assessment of innate immune function included cytokine expression in response to Toll-like receptor (TLR-2, TLR-4 and TLR-9) stimulation and phagocytosis assays using flow cytometry and live cell imaging-based techniques.

RESULTS

Circulating CD14⁺CD15^-CD11b⁺HLA-DR^- M-MDSCs were markedly expanded in patients with ACLF (55% of CD14+ cells). M-MDSC displayed immunosuppressive properties, significantly decreasing T cell proliferation (p=0.01), producing less tumour necrosis factor-alpha/interleukin-6 in response to TLR stimulation (all p<0.01), and reduced bacterial uptake of Escherichia coli (p<0.001). Persistently low expression of HLA-DR during disease evolution was linked to secondary infection and 28-day mortality. Recurrent TLR-2 and TLR-4 stimulation expanded M-MDSC in vitro. By contrast, TLR-3 agonism reconstituted HLA-DR expression and innate immune function ex vivo.

CONCLUSION

Immunosuppressive CD14⁺HLA-DR^- M-MDSCs are expanded in patients with ACLF. They were depicted by suppressing T cell function, attenuated antimicrobial innate immune responses, linked to secondary infection, disease severity and prognosis. TLR-3 agonism reversed M-MDSC expansion and innate immune function and merits further evaluation as potential immunotherapeutic agent.

MerTK expressing hepatic macrophages promote the resolution of inflammation in acute liver failure

OBJECTIVE

Acute liver failure (ALF) is characterised by overwhelming hepatocyte death and liver inflammation with massive infiltration of myeloid cells in necrotic areas. The mechanisms underlying resolution of acute hepatic inflammation are largely unknown. Here, we aimed to investigate the impact of Mer tyrosine kinase (MerTK) during ALF and also examine how the microenvironmental mediator, secretory leucocyte protease inhibitor (SLPI), governs this response.

DESIGN

Flow cytometry, immunohistochemistry, confocal imaging and gene expression analyses determined the phenotype, functional/transcriptomic profile and tissue topography of MerTK+ monocytes/macrophages in ALF, healthy and disease controls. The temporal evolution of macrophage MerTK expression and its impact on resolution was examined in APAP-induced acute liver injury using wild-type (WT) and Mer-deficient (Mer^-/-) mice. SLPI effects on hepatic myeloid cells were determined in vitro and in vivo using APAP-treated WT mice.

RESULTS

We demonstrate a significant expansion of resolution-like MerTK+HLA-DR^high cells in circulatory and tissue compartments of patients with ALF. Compared with WT mice which show an increase of MerTK+MHCII^high macrophages during the resolution phase in ALF, APAP-treated Mer^-/- mice exhibit persistent liver injury and inflammation, characterised by a decreased proportion of resident Kupffer cells and increased number of neutrophils. Both in vitro and in APAP-treated mice, SLPI reprogrammes myeloid cells towards resolution responses through induction of a MerTK+HLA-DR^high phenotype which promotes neutrophil apoptosis and their subsequent clearance.

CONCLUSIONS

We identify a hepatoprotective, MerTK+, macrophage phenotype that evolves during the resolution phase following ALF and represents a novel immunotherapeutic target to promote resolution responses following acute liver injury.

Patients with acute-on-chronic liver failure have increased numbers of regulatory immune cells expressing the receptor tyrosine kinase MERTK

BACKGROUND & AIMS

Characteristics of decompensated cirrhosis and acute-on-chronic liver failure (ACLF) include susceptibility to infection, immuneparesis, and monocyte dysfunction. MER receptor tyrosine kinase (MERTK) is expressed by monocytes and macrophages and contributes to down-regulation of innate immune responses. We investigated whether MERTK expression is altered on monocytes from patients with liver failure.

METHODS

We analyzed blood and liver samples collected from patients admitted to the liver intensive therapy unit at King's College Hospital in London from December 2012 through July 2014. Patients had either ACLF (n = 41), acute decompensation of cirrhosis without ACLF (n = 9), cirrhosis without decompensation (n = 17), or acute liver failure (n = 23). We also analyzed samples from healthy individuals (controls, n = 29). We used flow cytometry to determine the level of innate immune function, and associated the findings with disease severity. We developed an assay to measure recruitment and migration of immune cells from the tissue parenchyma. Immunohistochemistry and confocal microscopy were used to determine levels of MERTK in bone marrow, liver, and lymph node tissues. We performed immunophenotype analyses and measured the production of tumor necrosis factor and interleukin 6 and intracellular killing of Escherichia coli by monocytes and peritoneal macrophages incubated with lipopolysaccharide, with or without an inhibitor of MERTK (UNC569).

RESULTS

The number of monocytes and macrophages that expressed MERTK was greatly increased in the circulation, livers, and lymph nodes of patients with ACLF, compared with patients with stable cirrhosis and controls. MERTK expression (mean fluorescence intensity) correlated with the severity of hepatic and extrahepatic disease and systemic inflammatory responses. Based on immunophenotype, migration, and functional analyses, MERTK-expressing monocytes migrate across the endothelia to localize into tissue sites and regional lymph nodes. Expression of MERTK reduced the response of cultured monocytes to lipopolysaccharide; the addition of UNC569 restored production of inflammatory cytokines in response to lipopolysaccharide.

CONCLUSIONS

Patients with ACLF have increased numbers of immunoregulatory monocytes and macrophages that express MERTK and suppress the innate immune response to microbes. The number of these cells correlates with disease severity and the inflammatory response. MERTK inhibitors restore production of inflammatory cytokines by immune cells from patients with ACLF, and might be developed to increase the innate immune response in these patients.

Endometriosis - clinical approach based on histological findings

Endometriosis is a benign disease defined by the presence of endometrial glands and stroma outside of the uterus and is associated with both pelvic pain and infertility. The most common sites of endometriosis, in decreasing order of frequency, are the ovaries, anterior and posterior cul-de-sac, posterior broad ligaments, uterosacral ligaments, uterus, fallopian tubes, sigmoid colon, appendix, and round ligaments. The main treatment is surgical, but often-microscopic islands of endometrial tissue remain, which proliferate and are responsible for relapses. We tested the efficacy of two drugs (Medroxyprogesterone and Triptorelinum), administered for six months to prevent recurrence after surgery. Treatment with Medroxyprogesterone was 100% effective in terms of relapse, while Triptorelinum could not prevent recurrence of endometriosis.

Correlations between intratumoral vascular network and tumoral architecture in prostatic adenocarcinoma

The authors made a preliminary assessment of possible correlations between the intratumoral vascular density (IVD) and the architectural tumoral patterns described by Gleason. The studied material consisted of samples obtained by transurethral resection from 34 patients diagnosed with prostatic adenocarcinoma. Ten fields, five for dominant and five for secondary identified patterns of each case, with no necrosis were selected randomly from CD34 immunomarked sections using ×20 objective. IVD increased with Gleason pattern both for the entire group, but also for "solid" phenotype group of subtypes up to pattern 4, respectively subtype 4B. In "necrotizing" phenotype group of subtypes, IVD had a decreasing trend from the better-differentiated subtypes to the poorest one. These preliminary data showed that the intratumoral vascular network reacts differently to the loss of tumoral differentiation in the two groups of Gleason subtypes suggesting the existence of two different populations of malignant cells.

Clinical and morphological correlations in acute ischemic stroke

We studied the clinical and histopathological changes in twenty-seven cases of acute ischemic stroke, aged between 65 and 75 years. All deaths occurred within 30 days after stroke. The aim of our study was to establish the clinical and histological correlations in acute ischemic stroke to detect prognostic factors. Brain lesions after acute stroke were observed in all regions. Our study describes the heterogeneity of brain injury after acute ischemic stroke with the participation of all brain components and the chronology in which these lesions develop and evolve. By histological and immunohistochemical studies, we identified neuronal, glial and vascular damage. The neurons had undergone in the area of lesion a process of necrosis, ballooning or condensation process. In the ischemic penumbra, we observed the presence of red neurons. Vascular lesions were represented by the discontinuity of capillaries, always associated with a marked perivascular edema. The following clinical and morphological correlations were established: liquefactive necrosis, astrocyte gliosis, phagocytosis phenomena are the more intense the later the death of the patient; apoptosis phenomena are the more intense the faster the death of the patient; the entire cerebral microcirculation presented microscopic modifications following the ischemic strokes, regardless of the time since the lesion occurred and the histological examination was made; the major neurological complications of the ischemic stroke - the hemorrhagic transformation phenomena, cerebral edema, were microscopically objectified, regardless of the time since the lesion occurred and the histological examination was made.

Histological and immunohistochemical changes of the myocardium in dilated cardiomyopathy

Dilated cardiomyopathy is a major cause of heart failure and a major cause of morbidity and mortality. It is a multifactorial disease that includes both hereditary and acquired forms. It is estimated that around 20-35% of patients with dilated cardiomyopathy have hereditary forms. It is the third most common cause of heart failure and the most common cause of heart transplant. Dilated cardiomyopathy can be a secondary condition of many diseases such as coronary heart disease, diabetes, pheochromocytoma, infections, malnutrition, ingestion of toxic substances (alcohol, cocaine), ingestion of chemotherapeutic drugs, autoimmune diseases. In our study, we aimed to describe the changes of myocardial cells and interstitial connective tissue in patients clinically diagnosed with alcoholic dilated cardiomyopathy. The material studied consisted of heart fragments sampled from the left ventricle (LV) during necropsy from a total of 28 patients, aged between 58 and 73 years, with a clinical and laboratory diagnosis of dilated cardiomyopathy, hospitalized in the Cardiology Center of the Emergency County Hospital of Craiova in 2009 and 2010. In dilated cardiomyopathy, myocardial muscle fibers appeared slightly elongated or wavy, with hypochromatic, heterogeneous, vacuolar sarcoplasm, by a decrease of myofibril numbers. Lipofuscin granules were frequently seen in the sarcoplasm. Nuclear changes were consistent with sarcoplasmic alterations. Changes of the interstitial connective tissue were sometimes extensive and sometimes barely noticeable. The most common alteration of this structure was the onset and development of a mainly perivascular collagen fibrillogenetic process.

Chronic gastritis with intestinal metaplasia: clinico-statistical, histological and immunohistochemical study

Chronic gastritis has a high incidence in adults, causing progressive destruction of glandular structures, favoring the development of gastric atrophy. The association of chronic gastritis with intestinal type metaplasia of gastric mucosa has a poor outcome as intestinal metaplasia is regarded as a precancerous lesion. Metaplasia is common in patients with Helicobacter pylori infection and also heavy smokers. The aim of our study was to evaluate the relationship between chronic gastritis and intestinal metaplasia. The study was conducted on a total of 1218 patients, aged between 5 and 90 years, who presented for dyspeptic disorders in the period 2007-2010 and were examined clinically and endoscopically. During the gastroscopic examination, fragments of gastric mucosa were collected for the histopathological study and for highlighting the H. pylori infection. For the histopathological study, the Hematoxylin-Eosin and PAS-Alcian Blue stains were performed, while for the immunohistochemical study the anti-TAG72 and anti-PCNA antibodies were used. A diagnosis of gastritis was established in 615 patients, representing approximately 50.5% of all cases. Most cases with gastritis were found in people of middle age. Gastritis was present in almost all age groups, from teenagers to the elders. Of the 615 cases of gastritis, urease test was positive in 353 patients, representing approximately 57.40% of all patients with gastritis. Histopathological examination identified the presence of intestinal metaplasia in 61.60% of patients with chronic gastritis, mostly complete metaplasia. PCNA immunohistochemistry revealed that cell proliferation processes are intensified in intestinal metaplasia. This study highlights the importance of chronic gastritis, intestinal metaplasia, and H. pylori infection in the etiopathogeny of gastric cancer.

Correlations between intratumoral interstitial fibrillary network and tumoral architecture in prostatic adenocarcinoma

The authors made a preliminary assessment of possible correlations between the amount of intratumoral stromal fibrillary components (ISFC) and the architectural tumoral patterns described by Gleason. The studied material consisted of samples obtained by transurethral resection from 34 patients diagnosed with prostatic adenocarcinoma. Ten fields, five for dominant and five for secondary identified patterns of each case, with no necrosis were selected randomly from Gömöri stained sections using ×20 objective. ISFC-ratio increased with Gleason pattern both for the entire group but also for "Necrotizing" phenotype patterns and "Solid" phenotype patterns, excepting the subtype "4A" where the stromal compartment was reduced by the expansion of tumoral ducts enlarged by growing tumoral intraductal cribriform masses. These preliminary data showed that stromal microenvironment try to adapt to the loss of tumoral differentiation by increasing the amount of fibrillary components of intratumoral stromal compartment.

The importance of tumor proliferation markers in assessing lesions of the palatine tonsil

Oropharyngeal cancer, and especially squamous cell carcinoma, is one of the most common cancers worldwide, and its incidence is increasing, with the palatine tonsil being one of the main locations. The etiopathogenic factors, together with its location as well as the available immunohistochemical methods, make this type of cancer an accessible one in terms of diagnosis. However, it is usually diagnosed in late stages. Therefore, we tried to elucidate the causes of treatment failures and development of local recurrence. For this, we reassessed the proliferative pattern of tonsil lesions using the anti-p53, anti-PCNA and anti-Ki67 antibodies on 73 tonsil fragments collected after curative surgery on adults aged between 28 and 86 years. Following the reevaluation of the histopathological examination using markers for cell proliferation, the diagnosis was modified in 16 cases, representing about 22% of the cases take into study. By using immunohistochemical markers in the histopathological examination the diagnosis is improved, leading to a more appropriate therapeutical approach.

Preliminary study of bipolar hip prosthesis - influence of acetabular bone interactions on bone morphology

Periprosthetic bone changes following hip arthroplasty are yet to be completely described. The material consisted of imagistic records (X-ray films, CT and MRI scans) and of acetabular bone tissue sampled from 14 cases with femoral head prosthesis and revision of the prosthesis fixed and decalcified in Duboscq-Brazil solution and stained with Hematoxylin and Eosin, trichrome van Gieson and trichrome Masson. Acetabular bone is home of a great variety of morphological changes that can be divided in degenerative and regenerative changes seen in both compact and trabecular components but only inside the maximal pressure area of the acetabular roof. Our preliminary morphological study revealed the existence of an adaptation effort to the mechanical stress materialized through a dynamic process of bone remodeling in the maximal pressure area.

Histopathological and immunohistochemical aspects in chronic suppurative maxillary rhinosinusitis

Chronic rhinosinusitis is a multifactorial disease with pathophysiological mechanisms, which remain unclear, and with a high prevalence worldwide. They generate social problems due to the high number of days of leave and relatively elevated medical expenses. The histopathological and immunohistochemical study that we conducted revealed many lesional aspects of the epithelium of the sinus mucosa, which ranged from hypertrophy, hyperplasia and metaplasia, to erosion and discontinuities. In the chorion of the sinus mucosa there was an inflammatory infiltrate composed mainly of lymphocytes, plasma cells and macrophages, and also a highly developed vascular network. Among immune cells, T-cells appeared to be more numerous than B-lymphocytes and macrophages. We believe that microscopic changes are due mainly to microscopic organisms that make up the biofilm of the sinus cavity, whose virulence has been more or less influenced by exogenous or endogenous factors.

Study of cellular changes induced by moderate cerebral ischemia achieved through internal carotid artery ligation

Reduced cerebral blood flow beyond the compensatory mechanisms leads to cerebral hypoxia. Hypoxia causes various lesions of neurons, glial cells and cerebral blood vessels, depending on its duration and intensity. In our study, we reduced cerebral blood flow in the experience animal on average by 30%, by right internal carotid artery ligation. Fifteen days after the onset of hypoxia, by histology and immunohistochemical studies, we identified neuronal, glial and vascular damage. Lesions of nerve and glial cells ranged from changes of cytoplasmic tinting with the development of "red neurons", to neuronal and glial cytolysis with areas of focal necrosis. Vascular lesions were represented by the collapse, fragmentation and discontinuity of capillaries, always associated with a marked perivascular edema.

Pericytes and myofibroblasts reaction in experimental thermal third degree skin burns

Pericytes and myofibroblasts are two types of connective cells that appear in large quantities in reparative processes. In order to evaluate their response and any relationships between them, we have inflicted third degree skin burns to seven groups of five common Wistar rats each from which we sampled granulation tissue at three days interval for histological and immunohistochemical studies. Alpha-SMA and CD34 antibodies revealed that granulation tissue myofibroblasts do not express CD34 and do not arise from pericytes. The parallel arrangement of myofibroblasts in relation to the burned wound surface suggests that their main function is mechanical traction on granulation tissue and wound edges.

Histological and ultrastructural analysis of the seminiferous tubule wall in ageing testis

The authors evaluated possible morphological changes of basement membrane (BM) and lamina propria (LP) of seminiferous tubule wall (ST) related to ageing. Surgical samples of testicular tissue from 28 cases with orchiectomy for prostate adenocarcinoma were processed for light microscopy and transmission electron microscopy (TEM) examination. Seven age groups (AgGr) between 50 and 80 years were designed. Tissue samples were immunomarked for collagen IV and smooth muscle actin. Images were acquired and measured with a specialized software. Thirty ST were randomly selected, with ×40-objective, for each case. Five random determinations for each ST and each parameter were performed. Mean values/tubule, case and AgGr were calculated for each parameter. Regression line (RL), slope and significance test for slope were determined for each parameter correlation with ageing. BM mean value was around 0.5 μm, with narrow limits of ranging in AgGr but more extended individual limits. RL showed discrete decreasing trend with ageing but without an obvious statistical correlation. LP mean value was around 6 μm, also with narrow limits of ranging in AgGr and more extended individual limits. RL decreased discretely with ageing but without an obvious statistical correlation. TEM showed more prominent BM material and more collagen fibers and less fibroblasts in LP of older AgGr and higher fibroblasts density in LP of younger AgGr. Our results showed that BM thickness is apparently decreasing with ageing whereas LP presents extremely variable degenerative changes, with a "mosaic", focal distribution and no tendency to advance with ageing.

Correlations between intralobular interstitial morphological changes and epithelial changes in ageing testis

The study focuses on the possible influences of intra (I) lobular (L) stromal compounds [intertubular spaces and seminiferous (S) tubule (T) wall (W)] morphologic changes on S epithelium (E) during ageing process. The material consisted of surgical samples of testicular tissue from 192 patients with orchidectomy for prostate carcinoma. Seven age groups were designed, from 50 to 80 years. Tissue samples were fixed in neutral buffered formalin, embedded in paraffin stained with HE, Goldner and Gömöri and immunomarked (in a subgroup of 28 cases) for smooth muscle actin, collagen IV, and CD34. SE had an uneven involution, both individually and inter-individually, but with normal spermatogenesis in many of ST. E degenerative changes were seen mainly in L periphery. Different stages of maturation arresting were more frequent in older patients. IL septae had changes with extremely variable intensity, dispersed mainly in L periphery, without significant spread and without extensive trend with ageing. Leydig cells showed focal hyperplasia without extensive trend related with ageing. STW presented strictly in the internal layer of lamina propria (apposed to basement membrane of ES) a focal sclerosis, with variable extension concerning its presence, thickness and T circumference (T without sclerosis, with focal sclerosis and with fibro-hyaline "collar" - FHyC) but not related with ageing. IL arteriolae showed focal areas of degeneration with a wide individual and inter-individual range of intensity and extension, but not related with age. Capillary network (CN), with both its peri-T and intramural segments, was present in all age groups, with no quantitative endothelial changes and decreasing only in very old cases. FHyC was often associated with E atrophy. STW focal sclerosis could explain focal degeneration of SE in senescence, although CN undergoes no significant changes.

Angiogenesis assessment in experimental third degree skin burns: a histological and immunohistochemical study

In the past 30 years, after the discovery of vascular proliferation factors, angiogenesis is one of the most intensively studied fields. Restoring the vascular network after burn injury is essential for healing, as it brings oxygen and nutrients to injured tissues, improves the contribution of inflammatory cells and prepares the damaged area for repair and tissue regeneration. To study the process of angiogenesis we used seven groups of five animals, each of adult Wistar rats, which were inflicted with third degree skin burns. From each group of animals, we sampled at successive intervals of three days the entire burnt wound with a ring of surrounding normal skin. Sampled skin fragments were processed for paraffin inclusion, sectioned with a microtome and stained with Hematoxylin-Eosin or Masson trichrome. The samples were also analyzed using single chromogenic immunohistochemistry or double immunofluorescence for the presence of CD34 and alpha smooth muscle actin (α-SMA). Angiogenesis process started at about three days after the burn infliction, with the appearance of tubular structures lined by CD34-positive cells. Subsequently, these cells showed intense proliferative activity that generated a network that included progressive neovascularization around the wound surface. Maximum vascular proliferation occurred at 9-15 days after injury, when the number of capillaries reached 229/mm², and the total area of capillary angiogenesis at 100.27 μm² (about 10% of the section area). Subsequently, the process of angiogenesis was gradually reduced, but remained at moderate levels after wound healing. During the process of angiogenesis, there was a very close relationship between CD34-positive cells and pericytes (as α-SMA-positive).

Study of vascular microdensity in areas of cerebral ischemia on experimental model

Stroke is the third leading cause of death and the first cause of disability with an increasing incidence, especially of the ischemic type. There is no effective curative treatment for stroke and therefore the therapy for this disease currently relies on identifying patients at risk and instituting preventive measures. Since ischemic stroke in middle cerebral artery territory (and with preferential localization in the striated nuclei) is the main type of stroke in humans, animal models obtained by surgical ligation of the middle cerebral artery (MCAO) are valuable tools for the fundamental study of this disease. In this study, we investigated the morphological and immunohistochemical remodeling of the tissue after stroke and in particular the vascular component in a MCAO murine model. The analysis included the sequential sacrificing of animals at 1, 14, 28 and 60 days post-stroke and brain processing for paraffin embedding and sectioning. Our results show a gradual revascularization of the lesion as we move away from the time of the surgical intervention. This effect is accompanied by the development of an increasingly dense glial scar at the periphery of the lesion. The perilesional area itself, the penumbra, is characterized by minimal histological changes (such as eosinophilic neurons), but also by an increased expression of activated caspase 3 as a sign of apoptotic neurons and glial cells. Our study confirms the potential of the organism in its attempt to revascularize the injured area, and raises questions on the role of the glial scar in limiting the process of neovascularization.

Morphological experimental study of bone stress at the interface acetabular bone/prosthetic cup in the bipolar hip prosthesis

By calculating the tension and distortion of the elements composing the bipolar prosthesis under extreme conditions encountered in real life using a special post-processing program, we established the variation curves of the contact pressure at the hip bone-cup, armor-cup and cup-femoral head interface. By comparing the data obtained from all the examined cases, important conclusions were drawn regarding the influence of tension and pressure distribution on the structural integrity and biomechanics of the prosthesis, as well as the acetabular wear and tear, in order to assess its reliability. The experimentally determined tension and distortion status at the acetabular bone-metal armour interface, lead to the wear and tear phenomenon, which can be explained by three mechanisms and theories incompletely reflecting the overall process. The histopathologic study of the acetabular bone tissue using FEM (finite elements method) on surgically removed specimens will probably lead to the identification of a series of factors that could reduce the rate of the wear and tear process.

Comparative study between prostatic carcinoma G1-G3 and Gleason grading systems

The need of an accurate and prognostically valuable method for grading the prostatic carcinoma resulted in, in the last decades, a large number of systems, none of them succeeding in being unanimously accepted by the pathologists family. The authors selected and reassessed using Gleason system a group of 221 cases with prostatic adenocarcinoma previously diagnosed using a combined G1-G3 system. The results were converted from Gleason system to G1-G3 system and then compared with the initial diagnostics. The group was divided, following the type of surgical procedure used for drawing the tissue, into three groups: transvesical prostatectomies (TVP), transurethral resections (TUR) and needle biopsies (B). The concordance between the two systems was good, even the number of TUR and B specimens was significant (85% of the studied group) showing that any of them can be successfully used in current practice, depending only on pathologist's experience.

Assessment of Gleason system use on different types of prostatic tissue samples

One of the well-known and accepted methods of prostatic adenocarcinoma grading is Gleason system. The authors made a retrospective analysis of 221 prostatic adenocarcinomas divided into three groups (transvesical prostatectomies, transurethral resections and needle biopsies) following the type of surgical procedure used for drawing the tissue. Gleason scores and comparison between odd and even Gleason scores were assessed in the entire group and in each subgroup. High scores prevailed, meaning a tendency towards a low grade of differentiation. Even scores also prevailed meaning, on one hand, that, often, the examined specimen reveals only one pattern and, on the other hand, that surgical procedures as transurethral resections and unique needle biopsies cannot offer a sufficient material for examination, the multicentricity of prostatic carcinoma being well known.

Osteoarticular tuberculosis--a ten years case review

Extrapulmonary sites of tuberculosis must not be neglected as they are not so rarely fortuitous discovering. The morphological diagnosis of tuberculosis is generally easy to do. However, there are the atypical lesions rising diagnostic difficulties. The authors reviewed the histopathological diagnostic in 19 cases of osteoarticular tuberculosis lesions selected from 390 cases of surgical extrapulmonary granulomatous lesions, using for difficult cases, with atypical lesions, new diagnostic tools as immunohistochemistry and DNA amplification technique by the polymerase chain reaction.