SARS-CoV-2 infection impacts carbon metabolism and depends on glutamine for replication in Syrian hamster astrocytes.

COVID-19 causes more than million deaths worldwide. Although much is understood about the immunopathogenesis of the lung disease, a lot remains to be known on the neurological impact of COVID-19. Here, we evaluated immunometabolic changes using astrocytes in vitro and dissected brain areas of SARS-CoV-2 infected Syrian hamsters. We show that SARS-CoV-2 alters proteins of carbon metabolism, glycolysis, and synaptic transmission, many of which are altered in neurological diseases. Real-time respirometry evidenced hyperactivation of glycolysis, further confirmed by metabolomics, with intense consumption of glucose, pyruvate, glutamine, and alpha ketoglutarate. Consistent with glutamine reduction, the blockade of glutaminolysis impaired viral replication and inflammatory response in vitro. SARS-CoV-2 was detected in vivo in hippocampus, cortex, and olfactory bulb of intranasally infected animals. Our data evidence an imbalance in important metabolic molecules and neurotransmitters in infected astrocytes. We suggest this may correlate with the neurological impairment observed during COVID-19, as memory loss, confusion, and cognitive impairment.

Ultrasound-Guided Minimally Invasive Tissue Sampling: A Minimally Invasive Autopsy Strategy During the COVID-19 Pandemic in Brazil, 2020.

BACKGROUND: Minimally invasive autopsies, also known as minimally invasive tissue sampling (MITS), have proven to be an alternative to complete diagnostic autopsies (CDAs) in places or situations where this procedure cannot be performed. During the coronavirus disease 2019 (COVID-19) pandemic, CDAs were suspended by March 2020 in Brazil to reduce biohazard. To contribute to the understanding of COVID-19 pathology, we have conducted ultrasound (US)-guided MITS as a strategy. METHODS: This case series study includes 80 autopsies performed in patients with COVID-19 confirmed by laboratorial tests. Different organs were sampled using a standardized MITS protocol. Tissues were submitted to histopathological analysis as well as immunohistochemical and molecular analysis and electron microscopy in selected cases. RESULTS: US-guided MITS proved to be a safe and highly accurate procedure; none of the personnel were infected, and accuracy ranged from 69.1% for kidney, up to 90.1% for lungs, and reaching 98.7% and 97.5% for liver and heart, respectively. US-guided MITS provided a systemic view of the disease, describing the most common pathological findings and identifying viral and other infectious agents using ancillary techniques, and also allowed COVID-19 diagnosis confirmation in 5% of the cases that were negative in premortem and postmortem nasopharyngeal/oropharyngeal swab real-time reverse-transcription polymerase chain reaction. CONCLUSIONS: Our data showed that US-guided MITS has the capacity similar to CDA not only to identify but also to characterize emergent diseases.

Nicotinamide attenuates streptozotocin-induced diabetes complications and increases survival rate in rats: role of autonomic nervous system.

BACKGROUND: To evaluate the effect of nicotinamide prior to streptozotocin-induced (STZ) diabetes in baroreflex sensitivity and cardiovascular autonomic modulation, and its association with hemodynamics and metabolic parameters. METHODS: Methods: Male Wistar rats were divided into control (Cont) and STZ-induced diabetes (Diab). Half of the rats from each group received a single dose of nicotinamide (100 mg/Kg) before STZ injection (Cont+NicA and Diab+NicA). All groups were followed-up for 5 weeks. RESULTS: Body weight loss of more than 40% was observed in Diab throughout the period (Diab: 271.00 ± 12.74 g; Diab+NicA: 344.62 ± 17.82). Increased glycemia was seen in Diab rats (541.28 ± 18.68 mg/dl) while Diab+NicA group had a slight decrease (440.87 ± 20.96 mg/dl). However, insulin resistance was observed only in Diab. In relation to Cont, heart rate, mean blood pressure and diastolic function were reduced when compared to Diab, together with parasympathetic modulation and baroreflex sensitivity. All of these parameters were improved in Diab+NicA when compared to Diab. Improved baroreflex sensitivity and parasympathetic modulation were correlated with glycemia, insulin resistance, and body weight mass. Additionally, Diab+NicA group increased survival rate. CONCLUSIONS: Results suggest that the association of nicotinamide in STZ-induced diabetic rats prevents most of the expected derangements mainly by preserving parasympathetic and baroreflex parameters.

An autopsy study of the spectrum of severe COVID-19 in children: From SARS to different phenotypes of MIS-C.

BACKGROUND: COVID-19 in children is usually mild or asymptomatic, but severe and fatal paediatric cases have been described. The pathology of COVID-19 in children is not known; the proposed pathogenesis for severe cases includes immune-mediated mechanisms or the direct effect of SARS-CoV-2 on tissues. We describe the autopsy findings in five cases of paediatric COVID-19 and provide mechanistic insight into the mechanisms involved in the pathogenesis of the disease. METHODS: Children and adolescents who died with COVID-19 between March 18 and August 15, 2020 were autopsied with a minimally invasive method. Tissue samples from all vital organs were analysed by histology, electron microscopy (EM), reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). FINDINGS: Five patients were included, one male and four female, aged 7 months to 15 years. Two patients had severe diseases before SARS-CoV-2 infection: adrenal carcinoma and Edwards syndrome. Three patients were previously healthy and had multisystem inflammatory syndrome in children (MIS-C) with distinct clinical presentations: myocarditis, colitis, and acute encephalopathy with status epilepticus. Autopsy findings varied amongst patients and included mild to severe COVID-19 pneumonia, pulmonary microthrombosis, cerebral oedema with reactive gliosis, myocarditis, intestinal inflammation, and haemophagocytosis. SARS-CoV-2 was detected in all patients in lungs, heart and kidneys by at least one method (RT-PCR, IHC or EM), and in endothelial cells from heart and brain in two patients with MIS-C (IHC). In addition, we show for the first time the presence of SARS-CoV-2 in the brain tissue of a child with MIS-C with acute encephalopathy, and in the intestinal tissue of a child with acute colitis. Interpretation: SARS-CoV-2 can infect several cell and tissue types in paediatric patients, and the target organ for the clinical manifestation varies amongst individuals. Two major patterns of severe COVID-19 were observed: a primarily pulmonary disease, with severe acute respiratory disease and diffuse alveolar damage, or a multisystem inflammatory syndrome with the involvement of several organs. The presence of SARS-CoV-2 in several organs, associated with cellular ultrastructural changes, reinforces the hypothesis that a direct effect of SARS-CoV-2 on tissues is involved in the pathogenesis of MIS-C. FUNDING: Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Bill and Melinda Gates Foundation.

Salivary glands are a target for SARS-CoV-2: a source for saliva contamination.

The ability of the new coronavirus SARS-CoV-2 to spread and contaminate is one of the determinants of the COVID-19 pandemic status. SARS-CoV-2 has been detected in saliva consistently, with similar sensitivity to that observed in nasopharyngeal swabs. We conducted ultrasound-guided postmortem biopsies in COVID-19 fatal cases. Samples of salivary glands (SGs; parotid, submandibular, and minor) were obtained. We analyzed samples using RT-qPCR, immunohistochemistry, electron microscopy, and histopathological analysis to identify SARS-CoV-2 and elucidate qualitative and quantitative viral profiles in salivary glands. The study included 13 female and 11 male patients, with a mean age of 53.12 years (range 8-83 years). RT-qPCR for SARS-CoV-2 was positive in 30 SG samples from 18 patients (60% of total SG samples and 75% of all cases). Ultrastructural analyses showed spherical 70-100 nm viral particles, consistent in size and shape with the Coronaviridae family, in the ductal lining cell cytoplasm, acinar cells, and ductal lumen of SGs. There was also degeneration of organelles in infected cells and the presence of a cluster of nucleocapsids, which suggests viral replication in SG cells. Qualitative histopathological analysis showed morphologic alterations in the duct lining epithelium characterized by cytoplasmic and nuclear vacuolization, as well as nuclear pleomorphism. Acinar cells showed degenerative changes of the zymogen granules and enlarged nuclei. Ductal epithelium and serous acinar cells showed intense expression of ACE2 and TMPRSS receptors. An anti-SARS-CoV-2 antibody was positive in 8 (53%) of the 15 tested cases in duct lining epithelial cells and acinar cells of major SGs. Only two minor salivary glands were positive for SARS-CoV-2 by immunohistochemistry. Salivary glands are a reservoir for SARS-CoV-2 and provide a pathophysiological background for studies that indicate the use of saliva as a diagnostic method for COVID-19 and highlight this biological fluid's role in spreading the disease. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Salivary glands are a target for SARS-CoV-2: a source for salivacontamination

The ability of the new coronavirus SARS-CoV-2 to spread and contaminate is one of the determinants of the COVID-19 pandemic status. SARS-CoV-2 has been detected in saliva consistently, with similar sensitivity to that observed innasopharyngeal swabs. We conducted ultrasound-guided postmortem biopsies in COVID-19 fatal cases. Samples ofsalivary glands (SGs; parotid, submandibular, and minor) were obtained. We analyzed samples using RT-qPCR, immu-nohistochemistry, electron microscopy, and histopathological analysis to identify SARS-CoV-2 and elucidate qual-itative and quantitative viral proles in salivary glands. The study included 13 female and 11 male patients, with amean age of 53.12 years (range 8­83 years). RT-qPCR for SARS-CoV-2 was positive in 30 SG samples from18 patients (60% of total SG samples and 75% of all cases). Ultrastructural analyses showed spherical 70­100 nm viral particles, consistent in size and shape with the Coronaviridae family, in the ductal lining cell cytoplasm,acinar cells, and ductal lumen of SGs. There was also degeneration of organelles in infected cells and the presence of acluster of nucleocapsids, which suggests viral replication in SG cells. Qualitative histopathological analysis showedmorphologic alterations in the duct lining epithelium characterized by cytoplasmic and nuclear vacuolization, as wellas nuclear pleomorphism. Acinar cells showed degenerative changes of the zymogen granules and enlarged nuclei.Ductal epithelium and serous acinar cells showed intense expression of ACE2 and TMPRSS receptors. An anti-SARS-CoV-2 antibody was positive in 8 (53%) of the 15 tested cases in duct lining epithelial cells and acinar cellsof major SGs. Only two minor salivary glands were positive for SARS-CoV-2 by immunohistochemistry. Salivaryglands are a reservoir for SARS-CoV-2 and provide a pathophysiological background for studies that indicate theuse of saliva as a diagnostic method for COVID-19 and highlight this biological uid's role in spreading the disease.© 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

An autopsy study of the spectrum of severe COVID-19 in children: From SARS to different phenotypes of MIS-C

Background: COVID-19 in children is usually mild or asymptomatic, but severe and fatal paediatric cases have been described. The pathology of COVID-19 in children is not known; the proposed pathogenesis for severe cases includes immune-mediated mechanisms or the direct effect of SARS-CoV-2 on tissues. We describe the autopsy findings in five cases of paediatric COVID-19 and provide mechanistic insight into the mechanisms involved in the pathogenesis of the disease. Methods: Children and adolescents who died with COVID-19 between March 18 and August 15, 2020 were autopsied with a minimally invasive method. Tissue samples from all vital organs were analysed by histology, electron microscopy (EM), reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry (IHC). Findings: Five patients were included, one male and four female, aged 7 months to 15 years. Two patients had severe diseases before SARS-CoV-2 infection: adrenal carcinoma and Edwards syndrome. Three patients were previously healthy and had multisystem inflammatory syndrome in children (MIS-C) with distinct clinical presentations: myocarditis, colitis, and acute encephalopathy with status epilepticus. Autopsy findings varied amongst patients and included mild to severe COVID-19 pneumonia, pulmonary microthrombosis, cerebral oedema with reactive gliosis, myocarditis, intestinal inflammation, and haemophagocytosis. SARSCoV- 2 was detected in all patients in lungs, heart and kidneys by at least one method (RT-PCR, IHC or EM), and in endothelial cells from heart and brain in two patients with MIS-C (IHC). In addition, we show for the first time the presence of SARS-CoV-2 in the brain tissue of a child with MIS-C with acute encephalopathy, and in the intestinal tissue of a child with acute colitis. Interpretation: SARS-CoV-2 can infect several cell and tissue types in paediatric patients, and the target organ for the...(AU)

Acute renal denervation normalizes aortic function and decreases blood pressure in spontaneously hypertensive rats.

Mechanisms involved in the acute responses to renal denervation (RDN) have yet to be fully understood. We assessed urinary volume, autonomic control and aorta vascular reactivity after acute RDN. Male normotensive Wistar rats and spontaneously hypertensive rats (SHR) were divided into normotensive + RDN (ND) or sham surgery (NS), and hypertensive + RDN (HD) or sham surgery (HS). Metabolic parameters and hemodynamic measurements were recorded 72h and 4 days after intervention, respectively. Aortic rings were studied 7 days post RDN in an isometric myograph. Concentration-response curves to phenylephrine, sodium nitroprusside and acetylcholine (10-10-10-5 M) were performed. Two-way ANOVA was used for group comparisons and differences reported when p < 0.05. Results are presented as mean ± SEM. Urinary volume was 112% higher in HD vs. HS (HS = 14.94 ± 2.5 mL; HD = 31.69 ± 2.2 mL) and remained unchanged in normotensive rats. Systolic BP was lower in HD rats (HS = 201 ± 12 vs. HD = 172 ± 3 mmHg) without changes in normotensive group. HD group showed increased HF and LF modulation (HS = 5.8 ± 0.7 ms2 vs. HD = 13.4 ± 1.4 ms2; HS = 3.5 ± 0.7 ms2 vs. HD = 10.5 ± 1.7 ms2, respectively). RDN normalized vascular reactivity in HD rats and increased phenylephrine response in ND rats. Acute fall in BP induced by RDN is associated with increased urinary volume, which in turn may also have contributed to functional changes of the aorta.

Th17/Treg imbalance in COPD progression: A temporal analysis using a CS-induced model.

BACKGROUND: The imbalance between pro- and anti-inflammatory immune responses plays a pivotal role in chronic obstructive pulmonary disease (COPD) development and progression. To clarify the pathophysiological mechanisms of this disease, we performed a temporal analysis of immune response-mediated inflammatory progression in a cigarette smoke (CS)-induced mouse model with a focus on the balance between Th17 and Treg responses. METHODS: C57BL/6 mice were exposed to CS for 1, 3 or 6 months to induce COPD, and the control groups were maintained under filtered air conditions for the same time intervals. We then performed functional (respiratory mechanics) and structural (alveolar enlargement) analyses. We also quantified the NF-κB, TNF-α, CD4, CD8, CD20, IL-17, IL-6, FOXP3, IL-10, or TGF-ß positive cells in peribronchovascular areas and assessed FOXP3 and IL-10 expression through double-label immunofluorescence. Additionally, we evaluated the gene expression of NF-κB and TNF in bronchiolar epithelial cells. RESULTS: Our CS-induced COPD model exhibited an increased proinflammatory immune response (increased expression of the NF-κB, TNF-α, CD4, CD8, CD20, IL-17, and IL-6 markers) with a concomitantly decreased anti-inflammatory immune response (FOXP3, IL-10, and TGF-ß markers) compared with the control mice. These changes in the immune responses were associated with increased alveolar enlargement and impaired lung function starting on the first month and third month of CS exposure, respectively, compared with the control mice. CONCLUSION: Our results showed that the microenvironmental stimuli produced by the release of cytokines during COPD progression lead to a Th17/Treg imbalance.

Baroreflex Impairment Precedes Cardiometabolic Dysfunction in an Experimental Model of Metabolic Syndrome: Role of Inflammation and Oxidative Stress.

This study analyzes whether autonomic dysfunction precedes cardiometabolic alterations in spontaneously hypertensive rats (SHR) with fructose overload. Animals were randomly distributed into three groups: control, hypertensive and hypertensive with fructose overload. Fructose overload (100 g/L) was initiated at 30 days old, and the animals (n = 6/group/time) were evaluated after 7, 15, 30 and 60 days of fructose consumption. Fructose consumption reduced baroreflex sensitivity by day 7, and still induced a progressive reduction in baroreflex sensitivity over the time. Fructose consumption also increased TNFα and IL-6 levels in the adipose tissue and IL-1ß levels in the spleen at days 15 and 30. Fructose consumption also reduced plasmatic nitrites (day 15 and 30) and superoxide dismutase activity (day 15 and 60), but increased hydrogen peroxide (day 30 and 60), lipid peroxidation and protein oxidation (day 60). Fructose consumption increased arterial pressure at day 30 (8%) and 60 (11%). Fructose consumption also induced a late insulin resistance at day 60, but did not affect glucose levels. In conclusion, the results show that baroreflex sensitivity impairment precedes inflammatory and oxidative stress disorders, probably by inducing hemodynamic and metabolic dysfunctions observed in metabolic syndrome.

Blockade of AT1 type receptors for angiotensin II prevents cardiac microvascular fibrosis induced by chronic stress in Sprague-Dawley rats.

To test the effects of chronic-stress on the cardiovascular system, the model of chronic mild unpredictable stress (CMS) has been widely used. The CMS protocol consists of the random, intermittent, and unpredictable exposure of laboratory animals to a variety of stressors, during 3 consecutive weeks. In this study, we tested the hypothesis that exposure to the CMS protocol leads to left ventricle microcirculatory remodeling that can be attenuated by angiotensin II receptor blockade. Male Sprague-Dawley rats were randomly assigned into four groups: Control, Stress, Control + losartan, and Stress + losartan (N = 6, each group, losartan: 20 mg/kg/day). The rats were euthanized 15 days after CMS exposure, and blood samples and left ventricle were collected. Rats submitted to CMS presented increased glycemia, corticosterone, noradrenaline and adrenaline concentration, and losartan reduced the concentration of the circulating amines. Cardiac angiotensin II, measured by high-performance liquid chromatography (HPLC), was significantly increased in the CMS group, and losartan treatment reduced it, while angiotensin 1-7 was significantly higher in the CMS losartan-treated group as compared with CMS. Histological analysis, verified by transmission electron microscopy, showed that rats exposed to CMS presented increased perivascular collagen and losartan effectively prevented the development of this process. Hence, CMS induced a state of microvascular disease, with increased perivascular collagen deposition, that may be the trigger for further development of cardiovascular disease. In this case, CMS fibrosis is associated with increased production of catecholamines and with a disruption of renin-angiotensin system balance, which can be prevented by angiotensin II receptor blockade.

Aerobic exercise inhibits obesity-induced respiratory phenotype.

PURPOSE: Obesity results in decreased lung function and increased inflammation. Moderate aerobic exercise (AE) reduced lung inflammation and remodeling in a variety of respiratory disease models. Therefore, this study investigated whether AE can attenuate a diet-induced obesity respiratory phenotype; including airway hyper-responsiveness (AHR), remodeling and inflammation. METHODS: Sixty C57Bl/6 male mice were distributed into four groups: control lean (CL), exercise lean (EL), obese (O) and obese exercise (OE) groups (2 sets of 7 and 8 mice per group; n = 15). A classical model of diet-induced obesity (DIO) over 12 weeks was used. AE was performed 60 min/day, 5 days/week for 5 weeks. Airway hyperresponsiveness (AHR), lung inflammation and remodeling, adipokines and cytokines in bronchoalveolar lavage (BAL) was determined. RESULTS: A high fat diet over 18 weeks significantly increased body weight (p < .0001). Five weeks of AE significantly reduced both AHR and pulmonary inflammation. AHR in obese mice that exercised was reduced at the basal level (p < .05), vehicle (PBS) (p < .05), 6.25 MCh mg/mL (p < .05), 12.5 MCh mg/mL (p < .01), 25 MCh mg/mL (p < .01) and 50 MCh mg/mL (p < .05). Collagen (p < .001) and elastic (p < .001) fiber deposition in airway wall and also smooth muscle thickness (p < .001) were reduced. The number of neutrophils (p < .001), macrophages (p < .001) and lymphocytes (p < .01) were reduced in the peribronchial space as well as in the BAL: lymphocytes (p < .01), macrophages (p < .01), neutrophils (p < .001). AE reduced obesity markers leptin (p < .001), IGF-1 (p < .01) and VEGF (p < .001), while increased adiponectin (p < .01) in BAL. AE also reduced pro-inflammatory cytokines in the BAL: IL-1ß (p < .001), IL-12p40 (p < .001), IL-13 (p < .01), IL-17 (p < .001, IL-23 (p < .05) and TNF-alpha (p < .05), and increased anti-inflammatory cytokine IL-10 (p < .05). CONCLUSIONS: Aerobic exercise reduces high fat diet-induced obese lung phenotype (AHR, pulmonary remodeling and inflammation), involving anti-inflammatory cytokine IL-10 and adiponectin.

Immunoglobulin therapy ameliorates the phenotype and increases lifespan in the severely affected dystrophin-utrophin double knockout mice.

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder, caused by mutations in the dystrophin gene, affecting 1:3500-5000 boys worldwide. The lack of dystrophin induces degeneration of muscle cells and elicits an immune response characterized by an intensive secretion of pro-inflammatory cytokines. Immunoglobulins modulate the inflammatory response through several mechanisms and have been widely used as an adjuvant therapy for autoimmune diseases. Here we evaluated the effect of immunoglobulin G (IG) injected intraperitoneally in a severely affected double knockout (dko) mouse model for Duchenne muscular dystrophy. The IG dko treated mice were compared regarding activity rates, survival and histopathology with a control untreated group. Additionally, dendritic cells and naïve lymphocytes from these two groups and WT mice were obtained to study in vitro the role of the immune system associated to DMD pathophysiology. We show that IG therapy significantly enhances activity rate and lifespan of dko mice. It diminishes muscle tissue inflammation by decreasing the expression of costimulatory molecules MHC, CD86 and CD40 and reducing Th1-related cytokines IFN-γ, IL-1ß and TNF-α release. IG therapy dampens the effector immune responses supporting the hypothesis according to which the immune response accelerates DMD progression. As IG therapy is already approved by FDA for treating autoimmune disorders, with less side-effects than currently used glucocorticoids, our results may open a new therapeutic option aiming to improve life quality and lifespan of DMD patients.

Myocardial protection induced by fentanyl in pigs exposed to high-dose adrenaline.

The use of high doses of adrenaline is common in critical patients, especially during cardiac arrest. During these situations, myocardial dysfunction can be a result of multiple factors, including adrenaline use. In addition, opioids have been shown to have anti-arrhythmic and anti-ischemic mechanisms that may confer cardiac protection. This study aimed to evaluate the effects of fentanyl on myocardial function in pigs exposed to high-dose adrenaline. After institutional ethics committee approval, 26 pigs were randomly allocated to receive either 20 µg/kg fentanyl (n = 10; fentanyl group) administered 5 min before five doses of adrenaline (20 µg/kg), equivalent-volume saline (n = 10; saline group) using the same adrenaline dosing protocol, or neither fentanyl nor adrenaline (n = 6; sham group). The fentanyl group showed lower levels of troponin at the end of the sixth hour compared with the saline group (1.91 ± 1.47 vs 5.44 ± 5.35 ng/mL, P = 0.019). Transmission electron microscopy and immunohistochemistry also showed less myocardial injury in the fentanyl group. The conclusion was reached that fentanyl attenuates myocardial injury caused by high-dose adrenaline without blunting the hemodynamic effect of adrenaline.

Diagnosis of primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is a genetic disorder of ciliary structure or function. It results in mucus accumulation and bacterial colonization of the respiratory tract which leads to chronic upper and lower airway infections, organ laterality defects, and fertility problems. We review the respiratory signs and symptoms of PCD, as well as the screening tests for and diagnostic investigation of the disease, together with details related to ciliary function, ciliary ultrastructure, and genetic studies. In addition, we describe the difficulties in diagnosing PCD by means of transmission electron microscopy, as well as describing patient follow-up procedures.

Diagnosis of primary ciliary dyskinesia / Diagnóstico de discinesia ciliar primária

Primary ciliary dyskinesia (PCD) is a genetic disorder of ciliary structure or function. It results in mucus accumulation and bacterial colonization of the respiratory tract which leads to chronic upper and lower airway infections, organ laterality defects, and fertility problems. We review the respiratory signs and symptoms of PCD, as well as the screening tests for and diagnostic investigation of the disease, together with details related to ciliary function, ciliary ultrastructure, and genetic studies. In addition, we describe the difficulties in diagnosing PCD by means of transmission electron microscopy, as well as describing patient follow-up procedures.

Discinesia ciliar primária (DCP) é uma doença genética que compromete a estrutura e/ou a função ciliar, causando retenção de muco e bactérias no trato respiratório e levando a infecções crônicas nas vias aéreas superiores e inferiores, defeitos de lateralidade visceral e problemas de fertilidade. Revisamos os sinais e sintomas respiratórios da DCP, os testes de triagem e a investigação diagnóstica, bem como detalhes relacionados ao estudo da função, ultraestrutura e genética ciliar. Descrevemos também as dificuldades em diagnosticar a DCP por meio de microscopia eletrônica de transmissão, bem como o seguimento dos pacientes.

Tratamento da sequela de queimadura com uso de substituto dérmico aloplástico, avaliação clínica e histológica: estudo piloto / Clinical and histological evaluation of dermal regeneration in burn sequel with use of alloplastic dermal substitute: pilot stud

Introdução: O surgimento dos substitutos de regeneração dérmica nas duas últimas décadas permitiu um grande avanço no tratamento tanto das queimaduras agudas como das sequelas. No entanto, ainda há carência de informações sobre a relação entre os resultados clínicos e o que ocorre no tecido com cada tipo de matriz. Objetivo: Avaliar o aspecto histológico e correlacioná-lo aos resultados clínicos obtidos com o uso de dois tipos de substitutos dérmicos existentes no mercado, um deles mais fino e com uma lâmina de silicone (Integra®) e outro mais espesso e sem essa lâmina de silicone (Matriderm®). Método: Dez pacientes com sequelas de queimaduras foram tratados. Cada 5 pacientes receberam um desses dois tipos de matriz, ambos associados à terapia de pressão negativa. Após 19 dias, foi realizado um autoenxerto fino. Foram colhidas biópsias 12, 60 e 180 dias após o enxerto. Resultados: A análise histológica de ambos os substitutos mostrou o crescimento de tecido conjuntivo bem vascularizado sobre o leito cirúrgico destituído do tecido cicatricial original, com desenvolvimento adequado para recebimento do enxerto. Porém, houve diferenças quanto ao tempo de permanência no tecido, à integridade e à retração das matrizes: o substituto dérmico mais espesso apresentou maior retração tecidual, mas, também, maiores taxas de integração, e deixou de ser observado nos cortes histológicos mais precocemente em relação ao substituto fino com lâmina de silicone. Conclusão: O substituto dérmico de duas camadas (com lâmina de silicone) mostrou-se do ponto de vista clínico com menor retração ao longo de 6 meses, assim como com menor contagem de Vancouver. Do ponto de vista histológico, as diferenças foram apenas quanto à presença de matriz.

Introduction: The appearance of the dermal substitute regeneration over the last two decades has allowed large steps to be taken in the treatment of both acute burns and its sequels. However, there is still lack of information regarding the relationship between the clinical outcomes and what happens in the tissue with each kind of substitute. Objective: To evaluate the histological aspect and correlate it with the clinical results obtained using two kinds of dermal substitute available, one thinner and with a layer of silicone (Integra®) and one thicker and without silicone layers (Matriderm®). Methods: Ten patients with burn sequels were treated: 05 with Integra® and the others with Matriderm®, both associated to the therapy of negative pressure. After 19 days, a thin autograft was performed. After 12, 60 and 180 days from the grafting, biopsies were collected. Results: The histological analysis of both dermal substitutes has shown the growth of vascularized connective tissue where the scarred tissue was settled before, with the right development for receiving the graft. However, there were differences regarding the time it stayed on the tissue, the integrity and retraction of the dermal substitutes: the thicker dermal substitute has presented larger retraction of the tissue but, also, higher rates of integration and could no longer be observed in the histological cuts earlier than the thinner substitute with a silicon layer. Conclusion: Two layers dermal substitute (silicone sheet) proved from the clinical point of view with lower shrinkage over 6 months and less Vancouver count. From the histological point of view, the differences were only for the presence of the matrix.

Estudo comparativo entre pentoxifilina e triancinolona no tratamento das cicatrizes hipertróficas pós-queimadura quanto à remodelação do colágeno e das fibras do sistema elástico / Comparative study of pentoxifylline and triamcinolone in the treatment of post-burn hypertrophic scars on the collagen remodeling and elastic system fibers

Introdução: O tratamento das sequelas cicatriciais permanece um desafio na prática diária. Corticosteroides injetáveis são amplamente utilizados no combate a queloides e cicatrizes hipertróficas, mas substâncias como a pentoxifilina (PTF) também têm demonstrado eficácia clínica na modulação dessas cicatrizes. Objetivos: No presente estudo, propusemos a comparação dos efeitos da PTF e do corticosteroide triancinolona nas cicatrizes hipertróficas de pacientes vítimas de queimaduras por meio de análise histológica da organização das fibras que contêm colágeno e das fibras do sistema elástico. Métodos: Foram estudadas amostras de pele cicatricial de 10 pacientes, entre 20 e 40 anos, com história de queimaduras em tronco, com até 24 meses de evolução, não tratadas cirurgicamente. Cada paciente teve duas áreas cicatriciais tratadas, uma com Hexacetonido de Triancinolona 20 mg/ml e outra com Pentoxifilina 1 mg/ ml; tendo sido realizadas três aplicações intracicatriciais com intervalos mensais. Uma biópsia de cada área tratada foi colhida após 30 dias de cada aplicação. Resultados: Os resultados clínicos foram evidentes e semelhantes para as duas drogas: diminuição da espessura, do prurido, da hiperemia e da consistência da cicatriz. Não se observaram diferenças arquiteturais no tecido conjuntivo subepidérmico quando comparadas a cicatriz original com as cicatrizes após cada tipo de tratamento (grandes feixes de fibras colágenas em todas as direções, com ausência de fibras do sistema elástico). Estudos subsequentes envolvendo a análise da espessura total da cicatriz e o grau de vascularização/ inflamação presentes se fazem necessários na investigação da justificativa da eficácia clínica dos tratamentos. Conclusão: Concluímos que a PTF teve uma resposta clínica e morfológica similar à triancinolona nos casos tratados.

Introduction: The treatment of scarring sequelae remains challenge in daily practice. Injecting corticosteroids are widely used to combat keloids and hypertrophic scars, but substances such as pentoxifylline (PTF) have also demonstrated clinical efficacy in modulating these scars. Objectives: This study set out to compare the effects of TFP and corticosteroid triamcinolone in hypertrophic scars of burn victims by histological analysis of the organization of the fibers containing collagen and elastic system fibers. Methods: Scar skin samples from 10patients were studied between 20 and 40 years, with a history of burns on the trunk, up to 24 months of evolution, not surgically treated. Each patient had two treated scar areas, one with triamcinolone hexacetonide 20 mg/ml and the other with pentoxifylline 1 mg/ml; having been held three intracicatriciais applications at monthly intervals. A biopsy of each treated area was harvested after 30 days of each application. Results: The clinical results were evident and similar for the two drugs: thinning, itching, hyperemia and scar consistency. There were no differences in architectural subepidermal connective tissue when compared with the original scar scars after each treatment (large bundles of collagen fibers in all directions with no elastic system fibers). Subsequent studies involving the analysis of the total thickness of the scar and the extent of vascularization/inflammation gifts are needed to investigate the reasons of clinical efficacy of treatments. Conclusion: We conclude that TFP had a clinical and morphological response similar to triamcinolone in treated cases.

Endotoxemic myocardial dysfunction: subendocardial collagen deposition related to coronary driving pressure.

Sepsis impairs the autoregulation of myocardial microcirculatory blood flow, but whether this impairment is correlated with myocardial remodeling is unknown. This study investigated the role of coronary driving pressure (CDP) as a determinant of microcirculatory blood flow and myocardial fibrosis in endotoxemia and sepsis. The study is composed of two parts: a prospective experimental study and an observational clinical study. The experimental study was performed on male Wistar rats weighing 300 to 320 g. Endotoxemia was induced in rats by lipopolysaccharide (LPS) injection (10 mg·kg intraperitoneally). Hemodynamic evaluation was performed 1.5 to 24 h after LPS injection by measuring the mean arterial pressure, CDP, left ventricular end-diastolic pressure, dP/dtmax, and dP/dtmin. Microspheres were also infused into the left ventricle to measure myocardial blood flow, and myocardial tissue was histologically assessed to analyze collagen deposition. The CDP, mean arterial pressure, and myocardial blood flow were reduced by 55%, 30%, and 70%, respectively, in rats 1.5 h after LPS injection compared with phosphate buffer saline injection (P < 0.05). The CDP was significantly correlated with subendocardial blood flow (r = 0.73) and fibrosis (r = 0.8). Left ventricular function was significantly impaired in the LPS-treated rats, as demonstrated by dP/dtmax (6,155 ± 455 vs. 3,746 ± 406 mmHg·s, baseline vs. LPS; P < 0.05) and dP/dtmin (-5,858 ± 236 vs. -3,516 ± 436 mmHg·s, baseline vs. LPS; P < 0.05). The clinical study was performed on 28 patients with septic shock analyzed for CDP. The CDP data and histological slices were collected from septic patients. In addition, the clinical data demonstrated fibrosis and 45% CDP reduction in nonsurvivors compared with survivors. In conclusion, the left ventricular subendocardial blood flow was positively correlated with CDP, and higher CDP was negatively correlated with myocardial collagen deposition. Thus, early reductions in myocardial blood flow and CDP facilitate late myocardial fibrosis in rats and likely in humans.