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Anti-glomerular basement membrane (GBM) disease is a rare and severe vasculitis that affects the glomerular and pulmonary capillaries and has an incidence of less than 2 cases per million individuals per year. Anti-GBM disease is mediated by autoantibodies against the α3 chain of type IV collagen. In the majority of cases, the autoantibodies are of the immunoglobulin G (IgG) class, with rare cases being mediated by immunoglobulin M (IgM) or immunoglobulin A (IgA); there are less than 15 IgA-mediated cases reported in the literature worldwide. The classic form of this disease manifests with rapidly progressive glomerulonephritis (RPGN), with or without pulmonary hemorrhage, and the diagnosis consists of identifying high titers of autoantibodies in the serum and/or deposited in the tissues. IgA antibodies are not identified in routine immunoassay tests, and renal biopsy with immunofluorescence is essential for diagnosis. We present a case of RPGN due to anti-GBM disease with linear IgA deposition, whose diagnosis was made exclusively by renal biopsy and with an unfavorable prognosis.

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This short article discusses selected scanning electron microscope and transmission electron microscope features of vasa vasorum including pericytes and basement membrane of the human saphenous vein (SV) harvested with either conventional (CON) or no-touch (NT) technique for coronary artery bypass grafting. Scanning electron microscope data shows the general damage to vasa vasorum of CON-SV, while the transmission electron microscope data presents ultrastructural features of the vasa in more detail. Hence there are some features suggesting pericyte involvement in the contraction of vasa blood vessels, particularly in CON-SV. Other features associated with the vasa vasorum of both CON-SV and NT-SV preparations include thickened and/or multiplied layers of the basement membrane. In some cases, multiple layers of basement membrane embrace both pericyte and vasa microvessel making an impression of a "unit" made by basement membrane-pericyte-endothelium/microvessel. It can be speculated that this structural arrangement has an effect on the contractile and/or relaxing properties of the vessels involved. Endothelial colocalization of immunoreactive inducible nitric oxide synthase and endothelin-1 can be observed (with laser confocal microscope) in some of the vasa microvessels. It can be speculated that this phenomenon, particularly of the expression of inducible nitric oxide synthase, might be related to structurally changed vasa vessels, e.g., with expanded basement membrane. Fine physiological relationships between vasa vasorum endothelium, basement membrane, pericyte, and perivascular nerves have yet to be uncovered in the detail needed for better understanding of the cells'specific effects in SV preparations for coronary artery bypass grafting.

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Cell context is key for cell state. Using physiologically relevant models of laminin-rich extracellular matrix (lrECM) induction of mammary epithelial cell quiescence and differentiation, we provide a landscape of the key molecules for the proliferation-quiescence decision, identifying multiple layers of regulation at the mRNA and protein levels. Quiescence occurred despite activity of Fak (also known as PTK2), Src and phosphoinositide 3-kinases (PI3Ks), suggesting the existence of a disconnecting node between upstream and downstream proliferative signalling. Pten, a lipid and protein phosphatase, fulfils this role, because its inhibition increased proliferation and restored signalling via the Akt, mTORC1, mTORC2 and mitogen-activated protein kinase (MAPK) pathways. Pten and laminin levels were positively correlated in developing murine mammary epithelia, and Pten localized apicolaterally in luminal cells in ducts and near the nascent lumen in terminal end buds. Consistently, in three-dimensional acinogenesis models, Pten was required for triggering and sustaining quiescence, polarity and architecture. The multilayered regulatory circuitry that we uncovered provides an explanation for the robustness of quiescence within a growth-suppressive microenvironment, which could nonetheless be disrupted by perturbations in master regulators such as Pten.

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SUMMARY: To investigate changes of MMP-9 in the rat spleen and hypoxia-induced microvascular basement membrane under high altitude hypoxia. Thirty male specific pathogen-free Sprague Dawley rats were randomly divided into control and hypoxia groups, with 15 rats in each group. The rats in the control group were placed in Dingxi City, Gansu Province (2080 m above sea level) for 30 days. Rats in the hypoxia group were raised in a hypoxic environment in Maduo County, Qinghai Province (4300 m above sea level), for 30 days to establish a hypoxic rat model. Routine blood tests, MMP-9 mRNA, MMP-9 protein, and the spleen microvascular basement membrane were detected. (1) Compared with the control group, the red blood cell count, hemoglobin, and hematocrit levels of the rats in the hypoxia group were all increased; thus, a hypoxia model was successfully established. (2) Compared with the control group, the expression of MMP-9 mRNA and protein was significantly higher in the spleen of rats in the hypoxic group, and the difference was statistically significant (P <0.05). (3) Compared with the control group, the blood vessel basement membrane in the spleen of the hypoxia group was degraded. Under natural low air pressure and high altitude conditions, the expression of MMP-9 in rat spleen tissue increases and participates in the degradation of the microvascular basement membrane.

El objetivo de este trabajo fue investigar los cambios de la MMP-9 en el bazo de la rata y la membrana basal microvascular inducida bajo hipoxia a gran altura. Treinta ratas macho Sprague Dawley, libres de patógenos específicos, se dividieron aleatoriamente en dos grupos de 15 ratas cada uno, un grupo control y un grupo hipoxia. Durante 30 días las ratas del grupo control estuvieron en la ciudad de Dingxi, provincia de Gansu (2080 m sobre el nivel del mar). Las ratas del grupo de hipoxia se criaron en un entorno hipóxico en el condado de Maduo, provincia de Qinghai (4300 m sobre el nivel del mar), durante 30 días para establecer un modelo de rata hipóxica. Se realizaron análisis de sangre de rutina, ARNm de MMP-9, proteína MMP-9 y de la membrana basal microvascular del bazo. En comparación con el grupo control, el recuento de glóbulos rojos, la hemoglobina y los niveles de hematocrito de las ratas del grupo de hipoxia aumentaron; por lo tanto, se estableció con éxito un modelo de hipoxia. En comparación con el grupo control, la expresión de ARNm y proteína de MMP-9 fue significativamente mayor en el bazo de las ratas del grupo hipóxico, siendo la diferencia estadísticamente significativa (P <0,05). En comparación con el grupo control, la membrana basal de los vasos sanguíneos estaba degradada en el bazo del grupo hipoxia. En condiciones naturales de baja presión atmosférica y gran altitud, la expresión de MMP-9 en el tejido del bazo de la rata aumenta y participa en la degradación de la membrana basal microvascular.

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ABSTRACT This short article discusses selected scanning electron microscope and transmission electron microscope features of vasa vasorum including pericytes and basement membrane of the human saphenous vein (SV) harvested with either conventional (CON) or no-touch (NT) technique for coronary artery bypass grafting. Scanning electron microscope data shows the general damage to vasa vasorum of CON-SV, while the transmission electron microscope data presents ultrastructural features of the vasa in more detail. Hence there are some features suggesting pericyte involvement in the contraction of vasa blood vessels, particularly in CON-SV. Other features associated with the vasa vasorum of both CON-SV and NT-SV preparations include thickened and/or multiplied layers of the basement membrane. In some cases, multiple layers of basement membrane embrace both pericyte and vasa microvessel making an impression of a "unit" made by basement membrane-pericyte-endothelium/microvessel. It can be speculated that this structural arrangement has an effect on the contractile and/or relaxing properties of the vessels involved. Endothelial colocalization of immunoreactive inducible nitric oxide synthase and endothelin-1 can be observed (with laser confocal microscope) in some of the vasa microvessels. It can be speculated that this phenomenon, particularly of the expression of inducible nitric oxide synthase, might be related to structurally changed vasa vessels, e.g., with expanded basement membrane. Fine physiological relationships between vasa vasorum endothelium, basement membrane, pericyte, and perivascular nerves have yet to be uncovered in the detail needed for better understanding of the cells'specific effects in SV preparations for coronary artery bypass grafting.

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Renal involvement in COVID-19 infection is varied and worsens its outcome and prognosis. However, the association of COVID-19 infection with glomerulonephritis is exceptional. We report a 46-year-old woman with COVID-19 who had an acute kidney injury and ANCA associated glomerulonephritis two weeks after the onset of the disease. The kidney biopsy showed a crescentic glomerulo-nephritis and the presence of anti-glomerular basement membrane antibodies (GBM-Abs). She was treated with steroids and oral cyclophosphamide with good response without requiring plasmapheresis. Plasma anti GBM-Abs were negative. This case suggests that the presence of anti-GBM-Abs in the kidney, was temporally related to COVID-19 pulmonary damage. The absence of plasma antibodies is probably due to transient production and glomerular adsorption, but with unknown pathogenic role.

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ABSTRACT: Hybrid verrucous carcinoma (HVC) is defined as a rare neoplasm in which there is histopathological evidence of verrucous carcinoma and microscopic foci of squamous cell carcinoma, synchronously in the same site, affecting behavior and prognosis. This study aimed to present a new case of HVC in the mouth, and critically and comparatively analyze the cases reported in literature, to better understand the biological behavior and contribute to diagnostic precision. A review was performed using six databases, and the gray literature. Twenty-two articles were selected, with a total of 280 cases. The most frequent clinical appearance was verrucous carcinoma which included benign lesions. This implies that the potential for aggressive behavior can be detected microscopically, in the form of a ruptured basement membrane, which visualization can be facilitated by the use of some immunohistochemical markers discussed here. This is important for the diagnosis of HVC and adequate treatment. Hybrid verrucous carcinoma is what can be thought of as "a wolf in sheep's clothing." When analyzing cases with clinical suspicion of verrucous carcinoma microscopically, great attention is recommended, since they may be HVC and can recur, metastasize, and lead to death.

RESUMEN: El carcinoma verrugoso híbrido (CVH) se define como una neoplasia poco frecuente en la que existe evidencia histopatológica de carcinoma verrugoso y focos microscópicos de carcinoma de células escamosas, sincrónicamente en el mismo sitio, que afectan el comportamiento y el pronóstico. Este estudio tuvo como objetivo presentar un nuevo caso de CVH en la cavidad oral, y analizar crítica y comparativamente los casos reportados en la literatura, para comprender mejor el comportamiento biológico y contribuir a la precisión diagnóstica. Se realizó una revisión utilizando seis bases de datos y la literatura gris. Se seleccionaron veintidós artículos, con un total de 280 casos. La aparición clínica más frecuente fue el carcinoma verrugoso que incluyó lesiones benignas. Esto implica que el potencial de comportamiento agresivo puede detectarse microscópicamente, en forma de una membrana basal rota, cuya visualización puede ser facilitada por el uso de algunos marcadores inmunohistoquímicos discutidos aquí. Esto es importante para el diagnóstico de CVH y el tratamiento adecuado. El CVH es lo que se puede considerar como "un lobo con piel de oveja". Al analizar microscópicamente casos con sospecha clínica de carcinoma verrugoso, se recomienda una atención inmediata debido a que pueden ser CVH y pueden recurrir, metastatizar y conducir a la muerte.

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Epidermolysis bullosa (EB), a phenotypically and genetically heterogeneous disorder, has been linked to mutations in the genes encoding structural proteins that reinforce skin integrity via dermal-epidermal adhesion. Breakdowns in these adhesion mechanisms result in four different subtypes of EB classified on the basis of the level of tissue separation within the cutaneous basement membrane zone (BMZ). Mutations in as many as 17 distinct genes that encode structural proteins in the BMZ have been linked to EB. Despite the clinical and histopathological confirmation of EB, many cases remain genetically unsolved. Technical advancements in next-generation sequencing have paved the way for the identification of genes involved in the pathophysiology of EB. Structural proteins have long been identified as the candidate molecules altered in EB, however, recently non-structural proteins, encoded for example by PLOD3, USB1, EXPH5, and KLHL24, involved in enzymatic modification or migration of structural proteins have been implicated. In this overview, we discuss recent work regarding these proteins vis-à-vis their function, associated clinical manifestations, and involvement in the pathogenesis of EB.

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El síndrome de Alport es una entidad hereditaria que se produce principalmente por una mutación en los genes que codifican el colágeno tipo IV. Por otro lado, la glomerulonefritis C3 es una entidad rara que presenta un patrón de glomerulonefritis membranoproliferativa y su etiología se basa en un control anormal de la activación de la vía alternativa del complemento. A continuación se describe un caso de un paciente, de sexo masculino, que cursa con un síndrome nefrótico corticorresistente en el que se documenta un patrón de glomerulonefritis membranoproliferativa en la biopsia renal con depósitos de C3 en la inmunofluorescencia, asociada a una deleción heterocigota en el gen CFHR1 en el estudio genético de las proteínas reguladoras del complemento. Además, en el panel genético realizado por corticorresistencia se encuentra una variante COL4A5 asociada al síndrome de Alport ligado al X. Estas entidades pueden presentarse con un curso clínico diverso, pero al estar asociadas pueden acelerar la progresión a enfermedad renal crónica, por lo que se hace necesario hacer un seguimiento clínico más estricto.

Alport Syndrome is a hereditary entity that occurs mainly due to a mutation in the genes that encode type IV collagen. C3 glomerulonephritis is a rare entity with a pattern of membranoproliferative glomerulonephritis and its etiology is based on abnormal control of the activation of the alternative complement pathway. We describe a case of a male patient who presents with a corticosteroid nephrotic syndrome in which a pattern of membranoproliferative glomerulonephritis is documented in the renal biopsy with C3 deposits in the immunofluorescence, associated with a heterozygous deletion in the gene CFHR1 in the genetic study of complement regulatory proteins. Furthermore, a variant COL4A5 associated with X-linked Alport syndrome is found in the genetic panel for corticosteroid resistance. These entities can present with a diverse clinical course, but when associated they can accelerate progression to chronic kidney disease, which is why makes it necessary to do a more strict clinical follow-up.

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The purpose of this study was to examine the effect of topical and/or oral angiotensin converting enzyme II inhibitor and TGF-beta signaling blocker losartan on corneal stromal fibrosis that developed in rabbit corneas after Descemetorhexis removal of central Descemet's membrane and corneal endothelium. Twenty-eight New Zealand white rabbits were included and either had 8 mm central Descemetorhexis or sham control surgery without Descemetorhexis in one eye. Groups of 4 eyes without Descemetorhexis were treated for one month with no medications, topical losartan or oral losartan. Groups of 4 eyes with Descemetorhexis were treated with topical and oral vehicle, topical losartan, oral losartan, or both topical losartan and oral losartan for one month. Standardized slit lamp photos were obtained with central opacity intensity measured with ImageJ. The posterior fibrotic zone of corneas was measured on immunohistochemistry for alpha-smooth muscle actin (SMA) and keratocan using QuPath analysis. Collagen type IV expression in the posterior cornea was quantitated with ImageJ and duplex immunohistochemistry for collagen type IV and TGF beta-1. After Descemetorhexis, topical, but not oral, losartan decreased the intensity of central stromal opacity, reduced peripheral corneal scarring, and decreased alpha-smooth muscle actin myofibroblast fibrosis area compared to corneas that had Descemetorhexis and treatment with vehicles alone. Topical losartan decreased posterior stromal cellular, non-Descemet's membrane, collagen type IV production, that is likely stimulated by TGF beta as part of a negative regulatory feedback mechanism, compared to vehicle treatment at one month after Descemetorhexis. Topical losartan is likely to be effective in reducing corneal scarring fibrosis produced by traumatic injury, microbial infection, and some corneal diseases and surgeries.

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Lysyl oxidases (LOXs) are amino oxidase enzymes that catalyze the oxidative deamination of lysine and hydroxylysine residues to form allysine, the first step towards the development of the final cross-linking reaction in collagens, a crucial macromolecule that reinforces extracellular matrices. Basement membranes are specialized extracellular matrices that are essential components of the glomerular filtration barrier, which also support tubular epithelial cells. Lysyl oxidases are post-translational enzymes indispensable for tissue architecture, participating actively in the development and function of kidneys. The differential expression and dysregulation of these enzymes promote diabetic nephropathy, one of the major complications observed in end-stage renal diseases. In addition, these enzymes act as transcription factors that trigger the epithelial-mesenchymal transition responsible for the generation of different cancers. In the kidney, the expression studies in physiological conditions identified LOXL1 and LOXL2 as constituent proteins of glomerular basement membranes. Besides, LOX and LOXL2 are upregulated in fibrosis and renal cell carcinoma. The current review summarizes the physiological expression of LOXs enzymes in the nephrons, including glomerulus and tubules. Their roles in renal diseases are particularly highlighted in diabetic nephropathy and renal cell carcinoma, two pathophysiological conditions where these enzymes have been demonstrated to participate. The focus of the present study is to describe and discuss the current understanding in this field. The current potential of LOXs enzymes as a biomarker and pharmacological target to kidney diseases that involves extracellular matrix cross-linking enzymes is also discussed. LOXs isoforms and their capacity as therapeutic targets could be used for diagnostic and prognostic purposes and in treating these renal complications.

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We report clinical, serologic, and immunogenetic studies of a set of monozygotic male twin patients who develop autoimmune thyroiditis and vitiligo associated with the HLA-DRB1*04-DQB1*03:02 and HLA-DRB1*03-DQB1*0201 haplotypes. The patients had detectable anti-thyroid and anti-melanocyte autoantibodies. A critical review is presented regarding the role of MHC II molecules linked to clinical manifestations of various autoimmune diseases displayed in a single patient, as is the case in the twin patients reported here.

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The purpose of this investigation was to study Descemet's membrane and corneal endothelial regeneration, myofibroblast generation and disappearance, and TGF beta-1 localization after Descemet's membrane-endothelial excision (Descemetorhexis) in rabbits. Thirty-six rabbits had 8 mm Descemetorhexis and standardized slit lamp photos at 1, 2 and 4 days, 1, 2 and 4 weeks, and 2, 4 and 6 months, as well as multiplex IHC for stromal cell markers keratocan, vimentin, and alpha-smooth muscle actin (SMA); basement membrane (BM) components perlecan, nidogen-1, laminin alpha-5, and collagen type IV; and corneal endothelial marker Na,K-ATPase ß1, and TGF beta-1, with ImageJ quantitation. Stromal transparency increased from the periphery beginning at two months after injury and progressed into the central cornea by six months. At six months, central transparency was primarily limited by persistent mid-stromal neovascularization. Stromal myofibroblast zone thickness in the posterior stroma peaked at one month after injury, and then progressively decreased until to six months when few myofibroblasts remained. The regeneration of a laminin alpha-5 and nidogen-1 Descemet's membrane "railroad track" structure was accompanied by corneal endothelial closure and stromal cell production of BM components in corneas from four to six months after injury. TGF beta-1 deposition at the posterior corneal surface from the aqueous humor peaked at one day after Descemetorhexis and diminished even before regeneration of the endothelium and Descemet's membrane. This decrease was associated with collagen type IV protein production by corneal fibroblasts, and possibly myofibroblasts, in the posterior stroma. Descemet's membrane and the corneal endothelium regenerated in the rabbit cornea by six months after eight mm Descemetorhexis. Real-time quantitative RT-PCR experiments in vitro with marker-verified rabbit corneal cells found that 5 ng/ml or 10 ng/ml TGF beta-1 upregulated col4a1 or col4a2 mRNA expression after 6 h or 12 h of exposure in corneal fibroblasts, but not in myofibroblasts. Stromal cells produced large amounts of collagen type IV that likely decreased TGF beta-1 penetration into the stroma and facilitated the resolution of myofibroblast-generated fibrosis.

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Snakebite envenoming is a neglected tropical disease affecting millions of people every year, especially in vulnerable rural populations in the developing world. Viperid snakes cause envenomings characterized by a complex pathophysiology which includes local and systemic hemorrhage due to the action of snake venom metalloproteinases (SVMPs). The pathogenesis of SVMP-induced systemic hemorrhage has not been investigated in detail. This study explored the pulmonary hemorrhage induced in a murine model by a P-III SVMP from the venom of Crotalus simus. Histological analysis revealed extravasation in the lungs as early as 15 min after intravenous injection of the toxin, and hemorrhage increased at 360 min. Western blot analysis demonstrated the cleavage of basement membrane (BM) proteins in lung homogenates and in bronchoalveolar lavage fluid, implying an enzymatic disruption of this extracellular matrix structure at the capillary-alveolar barrier. Likewise, alveolar edema was observed, with an increment in protein concentration in the bronchoalveolar lavage fluid, and a neutrophil-rich inflammatory infiltrate was present in the parenchyma of the lungs as part of the inflammatory reaction. Pretreatment of mice with indomethacin, pentoxifylline and an anti-neutrophil antibody resulted in a significant decrease in pulmonary hemorrhage at 360 min. These findings suggest that this P-III SVMP induces acute lung injury through the direct action of this enzyme in the capillary-alveolar barrier integrity, as revealed by BM degradation, and as a consequence of the inflammatory reaction that develops in lung tissue. Our findings provide novel clues to understand the mechanism of action of hemorrhagic SVMPs in the lungs.

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Chaetodon striatus is a cosmopolitan seawater species present in aquaria all over the world and its extractivism is quite high. The lack of studies on the reproductive biology of C. striatus contributes to the difficulty in managing the species outside its natural habitat. Without knowledge of the mechanisms that control or affect gonadal changes, reproduction of C. striatus in captivity has become almost impossible, considering that the species is quite sensitive and the effect of captive conditions on its reproductive biology is unknown. Therefore, this study aimed to evaluate the effect on its reproductive biology of the animal's confinement and possible alteration in structure of the ovaries. In C. striatus, after oocyte development, for animals confined in small spaces, maturing oocytes undergo atresia. During atresia, ovarian follicles were at different stages of degeneration, characterized by the progressive loss of the basement membrane and disorganization of the follicle complex. In the advanced stage of follicular atresia, there was total loss of the basement membrane, culminating in degradation of the follicle complex. In unconfined animals, oocyte development and maturation were not affected. Confinement also affected the cell structure of the germinal epithelium, which showed large numbers of apoptotic bodies. The difference in cortisol and glucose levels between the unconfined and confined groups was significant, which may have to do with the change found in the ovaries, such as extensive follicular atresia and loss of the basement membrane.

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RESUMEN Una vez más en medicina interna no podemos, aún, prescindir de los métodos invasivos para alcanzar un diagnóstico. Los avances diarios en el hallazgo de nuevas herramientas paraclínicas no permiten reemplazar aquellos métodos de certeza como la anatomía patológica. El caso presentado es una muestra de ello. Se trata de una mujer de 27 años de edad, con antecedente de tiroiditis de Hashimoto que consulta por presentar severo deterioro de la función renal asociado a oligoanuria. Realizamos una revisión del tratamiento de las glomerulonefritis rápidamente progresivas por anticuerpos antimembrana basal glomerular, serológicamente negativas.

ABSTRACT Once again in internal medicine we cannot do a diagnosis without invasive methods. Daily advances in the finding of new paraclinical tools do not allow the replacement of certain methods such as pathological anatomy. The case presented is a sample of this. This is a 27-year-old woman with a history of Hashimoto's thyroiditis who consults for presenting severe impairment of kidney function associated with oligoanuria. We performed a review of the treatment of the rapidly progressive glomerulonephritis for serologically negative anti-GBM antibodies.

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Abstract Introduction The extent of epithelial lesion in allergic and non-allergic rhinitis and its association with inflammatory changes in nasal lavage has not been clarified. Objective To verify the association between the inflammatory cells in the nasal lavage, epithelial lesion extent and basement membrane thickness, in the nasal mucosa of patients with rhinitis; to determine the cutoff point of the percentage of eosinophils in the nasal lavage associated with the atopic patients. Methods Patients with rhinitis and indication for septoplasty and (or) turbinectomy for turbinate hypertrophy were selected, and were submitted to allergy skin tests, nasal lavage with measurement of albumin and interleukin-8 levels, total and differential counting of cells, and mucosal histopathological analysis to determine the extent of epithelial lesion, and degree of basement membrane thickening. Results Fifty-six patients with a median age of 24.5 years and a diagnosis of allergic rhinitis (n = 36) and non-allergic rhinitis (n = 20) were studied. In atopic subjects, allergy skin tests were positive for Dermatophagoides pteronyssinus in 35 (97.0%) and Lolium perenne in 18 (50.0%). Atopic subjects showed a higher clinical score index of rhinitis compared to non-atopic ones. The total count of cells, neutrophils, and levels of albumin and IL-8 were not different in the nasal lavage of atopic and non-atopic subjects. The cutoff point for eosinophil count in nasal fluid for the distinction between allergic rhinitis and non-allergic rhinitis was 4%. Some degree of epithelial lesion was more frequent in allergic rhinitis (94%) than in non-allergic rhinitis (65%) patients. In the presence of basement membrane thickness, as a marker of remodeling, there was no difference in the nasal lavage of patients with allergic rhinitis and non-allergic rhinitis. Conclusion In this series, 4% was the cutoff point for the number of eosinophils in the nasal lavage, for atopy differentiation. Upper airway remodeling accessed by basement membrane thickness showed similar inflammatory cell infiltrate in the nasal lavage, regardless of the presence of atopy.

Resumo Introdução A extensão da lesão epitelial na rinite alérgica e não alérgica e sua associação com alterações inflamatórias no lavado nasal ainda não estão esclarecidas. Objetivo Verificar a relação entre o processo inflamatório no lavado nasal, extensão da lesão epitelial e espessamento da membrana basal na mucosa nasal de pacientes com rinite; determinar o ponto de corte do percentual de eosinófilos no lavado nasal associado à presença de atopia. Método Foram selecionados pacientes com rinite e indicação de septoplastia e (ou) turbinectomia por hipertrofia de conchas nasais, os quais foram submetidos aos testes cutâneos alérgicos, lavado nasal com determinação das concentrações de albumina, interleucina-8 (IL-8), contagem total e diferencial de células, análise da extensão da lesão epitelial, e grau de espessamento da membrana basal por meio de histopatologia da mucosa. Resultado Foram estudados 56 pacientes, mediana de 24,5 anos com diagnóstico de rinite alérgica (n = 36) e rinite não alérgica (n = 20). Nos atópicos os testes cutâneos alérgicos foram positivos para D. pteronyssinus em 35 (97,0%) e L. perenne em 18 (50,0%). Atópicos apresentaram maior índice de escore clínico para rinite em comparação a não atópicos. A contagem total de células, neutrófilos e níveis de albumina e IL-8 não foi diferente entre o lavado nasal de atópicos e não atópicos. O ponto de corte da contagem de eosinófilos no fluido nasal para a distinção de rinite alérgica e rinite não alérgica foi de 4%. Algum grau de lesão epitelial foi mais frequente em pacientes com rinite alérgica (94%) do que em pacientes com rinite não alérgica (65%). Na presença de espessamento da membrana basal, como marcador de remodelamento, não houve diferença no lavado nasal entre pacientes com rinite alérgica e não alérgica. Conclusão Nesta casuística, 4% foi o ponto de corte do número de eosinófilos no lavado nasal, para diferenciação de atopia. Remodelamento da via aérea superior pelo espessamento da membrana basal revelou infiltrado semelhante de células inflamatórias no lavado nasal, independentemente da presença de atopia.

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Liver is an essential organ that carries out multiple functions such as glycogen storage, the synthesis of plasma proteins, and the detoxification of xenobiotics. Hepatocytes are the parenchyma that sustain almost all the functions supported by this organ. Hepatocytes and non-parenchymal cells respond to the mechanical alterations that occur in the extracellular matrix (ECM) caused by organogenesis and regenerating processes. Rearrangements of the ECM modify the composition and mechanical properties that result in specific dedifferentiation programs inside the hepatic cells. Quiescent hepatocytes are embedded in the soft ECM, which contains an important concentration of fibrillar collagens in combination with a basement membrane-associated matrix (BM). This work aims to evaluate the role of fibrillar collagens and BM on actin cytoskeleton organization and the function of rat primary hepatocytes cultured on soft elastic polyacrylamide hydrogels (PAA HGs). We used rat tail collagen type I and Matrigel® as references of fibrillar collagens and BM respectively and mixed different percentages of collagen type I in combination with BM. We also used peptides obtained from decellularized liver matrices (dECM). Remarkably, hepatocytes showed a poor adhesion in the absence of collagen on soft PAA HGs. We demonstrated that collagen type I inhibited apoptosis and activated extracellular signal-regulated kinases 1/2 (ERK1/2) in primary hepatocytes cultured on soft hydrogels. Epidermal growth factor (EGF) was not able to rescue cell viability in conjugated BM but affected cell aggregation in soft PAA HGs conjugated with combinations of different proportions of collagen and BM. Interestingly, actin cytoskeleton was localized and preserved close to plasma membrane (cortical actin) and proximal to intercellular ducts (canaliculi-like structures) in soft conditions; however, albumin protein expression was not preserved, even though primary hepatocytes did not remodel their actin cytoskeleton significantly in soft conditions. This investigation highlights the important role of fibrillar collagens on soft hydrogels for the maintenance of survival and aggregation of the hepatocytes. Data suggest evaluating the conditions that allow the establishment of optimal biomimetic environments for physiology and cell biology studies, where the phenotype of primary cells may be preserved for longer periods of time.

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Human amniotic membrane (HAM) is a biomaterial with biological properties beneficial to tissue repair, serving as a substrate for cell cultivation. Irradiation is used for tissue sterilization, but can damage the HAM structure. The objective of this paper was to construct a skin substitute, composed of human keratinocytes cultured on glycerolated HAMs, and to evaluate the influence radiation on subsequent cell culture growth. Four batches of HAMs were glycerolated, and half of them were radio-sterilzed with 25 kGy. Non-irradiated glycerolated HAM (ni-HAM) and irradiated glycerolated HAM (i-HAM) samples were then de-epithelized and analyzed using optical microscopy (Picrossirius staining), immunofluorescence and electron microscopy. Subsequently, keratinocytes were cultured on ni- and i-HAMs, and either immersed or positioned at the air-liquid interface. The basement membranes of the ni-HAM group remained intact following de-epithelialization, whereas the i-HAM group displayed no evidence or remnant presence of these membranes. Concerning the keratinocyte cultures, the ni-HAM substrate promoted the growth of multi-layered and differentiated epithelia. Keratinocytes cultured on i-HAM formed epithelium composed of three layers of stratification and discrete cell differentiation. The glycerolated HAM was compatible with cultured epithelia, demonstrating its potential as a skin substitute. Irradiation at 25 kGy caused structural damage to the amnion.

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BACKGROUND: Melasma is a chronic acquired focal hypermelanosis which pathogenesis has not been fully elucidated. Classical pathophysiologic studies have analysed the affected and perilesional areas, but little is known about the status of sun-protected skin, which is subjected to the same endogenous and genetic factors. OBJECTIVE: To assess the histological characteristics of melasma compared to adjacent and retroauricular skin. METHODS: Skin samples were collected from 10 female from: melasma, perilesional area and retroauricular. The samples were stained (haematoxylin-eosin, periodic acid-Schiff, Fontana-Masson, picrosirius red, toluidine blue and Verhoeff), immunolabelled for CD34 and Wnt1. The data from the skin sites were analysed simultaneously by a multivariate model. RESULTS: Melasma skin exhibited noteworthy stratum corneum compaction, greater collagen heterogeneity, solar elastosis, higher number of mast cells, basement membrane zone (BMZ) damage, Wnt1 expression, pendulum melanocytes, higher cellularity and vascular proliferation at the superficial dermis. Stratum corneum compaction, collagen heterogeneity and BMZ abnormalities were variables associated to melasma that not follow a continuum through retroauricular to adjacent skin. Mast cell count was the variable that disclosed correlation with the most other abnormalities as well as had the greater contribution in the multivariate model. CONCLUSION: In addition to melanocyte hyperactivity, melasma skin exhibits alterations in the epidermal barrier, upper dermis and BMZ, which differ from the adjacent sun-exposed skin and retroauricular skin, indicating a distinct phenotype, rather than a mere extension of photoageing or intrinsic ageing. Mast cells appear to play a central role in the physiopathology of melasma.