Histopathologic and Immunohistochemical Assessment of Acute Respiratory Distress Syndrome (ARDS): Challenges and Complexities of Postmortem Diagnosis.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition due to acute lung injury (ALI), characterized by rapid-onset respiratory failure, leading to the clinical manifestations of poor lung compliance, severe hypoxemia, and dyspnea. ARDS/ALI has many causes, most commonly related to infections (sepsis, pneumonia), traumas, and multiple transfusions. The objective of this study is to assess the performance of postmortem anatomopathological examination in identifying etiological agents associated with ARDS or ALI in deceased patients from the State of São Paulo from 2017 to 2018.

RBD and Spike DNA-Based Immunization in Rabbits Elicited IgG Avidity Maturation and High Neutralizing Antibody Responses against SARS-CoV-2.

Neutralizing antibodies (nAbs) are a critical part of coronavirus disease 2019 (COVID-19) research as they are used to gain insight into the immune response to severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) infections. Among the technologies available for generating nAbs, DNA-based immunization methods are an alternative to conventional protocols. In this pilot study, we investigated whether DNA-based immunization by needle injection in rabbits was a viable approach to produce a functional antibody response.

IMMUNOHISTOCHEMICAL ASSESSMENT OF LYMPHATIC VESSELS IN HUMAN LIVERS WITH CHRONIC HEPATITIS C - RELATION TO HISTOLOGICAL VARIABLES.

Background: Viral hepatitis C is a significant public health challenge. The disease may remain clinically silent in both acute and chronic forms, and chronic infections may progress to advanced disease such as cirrhosis and hepatocellular carcinoma, requiring costly treatment, compromising the patient's quality of life and even leading to death. For this reason, it is one of the most frequent indications for liver transplantation.

Immunophenotype of the inflammatory response in the central and enteric nervous systems of cockatiels () experimentally infected with parrot bornavirus 2.

Proventricular dilatation disease is a lethal disease of psittacine birds. In this study, we characterized the local cellular immune response in the brain, proventriculus, and small intestine of 27 cockatiels () experimentally infected with parrot bornavirus 2 (PaBV-2). Perivascular cuffs in the brain were composed of CD3+ T-lymphocytes and Iba1+ macrophages/microglia in most cockatiels (n = 26).

Gastric cancer molecular classification based on immunohistochemistry and in situ hybridization: Analysis in western patients after curative-intent surgery.

Background: Gastric cancer (GC) is a highly heterogeneous disease, and the identification of molecular subtyping of gastric adenocarcinoma emerged as a promising option to define therapeutic strategies and prognostic subgroups. However, the costs and technical complexity of molecular methodologies remains an obstacle to its adoption, and their clinical significance by other approaches needs further evidence.

Aim: To evaluate the clinicopathological characteristics and long-term survival of GC based on the subgroups of molecular classification by immunohistochemistry (IHC) and in situ hybridization (ISH).

Surveillance of hemorrhagic fever and/or neuroinvasive disease: challenges of diagnosis.

Objective: To evaluate the performance of post mortem laboratory analysis in identifying the causes of hemorrhagic fever and/or neuroinvasive disease in deaths by arbovirus infection.

Methods: Retrospective cross-sectional study based on the differential analysis and final outcome obtained in patients whose samples underwent laboratory testing for arboviruses at the Pathology Center of the Adolfo Lutz Institute, in São Paulo, Brazil.

Results: Of the 1355 adults clinically diagnosed with hemorrhagic fever and/or neuroinvasive disease, the most commonly attributed cause of death and the most common final outcome was dengue fever.

Yellow Fever as Cause of Death of Titi Monkeys ( Spp.).

From 2016 to 2018, an epidemic wave of yellow fever (YF) occurred in Brazil, affecting a large number of Platyrrhini monkeys. Titi monkeys ( spp.) were severely affected yet pathological characterizations are lacking.

Presumptive Primary Cerebral T-Cell Lymphoma in a White-Tailed Deer (Odocoileus virginianus).

Primary central nervous system (CNS) lymphomas are rare in humans and even more uncommon in animals. We report the clinical, pathological and immunohistochemical features of a presumptive primary cerebral T-cell lymphoma (PCTCL) in an aged female white-tailed deer (Odocoileus virginianus) that had chronic progressive neurological disease characterized by ataxia, claudication and eventual circling. The animal was euthanized due to poor prognosis.

Yellow fever surveillance challenge: Investigation of a marmoset non-autochthonous case.

Yellow fever (YF) surveillance in Brazil is focused mainly on the detection of epizootic events regarding New World non-human primates (NWNHP). We present a challenging case of a Callitrichidae (Callithrix spp) kept as a domiciliated pet that lived in the urban area of São Paulo municipality and was positive to YF virus by RT-qPCR and immunohistochemistry. After investigation, it was the first occurrence of non-autochthonous YF case of NWNHP described, with probable place of infection in the North shore of São Paulo state.

Genomic Surveillance of Yellow Fever Virus Epizootic in São Paulo, Brazil, 2016 - 2018.

São Paulo, a densely inhabited state in southeast Brazil that contains the fourth most populated city in the world, recently experienced its largest yellow fever virus (YFV) outbreak in decades. YFV does not normally circulate extensively in São Paulo, so most people were unvaccinated when the outbreak began. Surveillance in non-human primates (NHPs) is important for determining the magnitude and geographic extent of an epizootic, thereby helping to evaluate the risk of YFV spillover to humans.

Against All Odds: RNA Extraction From Different Protocols Adapted to Formalin-fixed Paraffin-embedded Tissue.

For the preservation of tissue samples, formalin fixation followed by paraffin embedding (FFPE) has been the method of choice for decades, mainly because it maintains the morphologic characteristics of the original tissue particularly preserved, as well as its genetic material. FFPE cells can be used to perform molecular tests, such as conventional (c) or quantitative (q) reverse transcriptase polymerase chain reaction (RT-PCR), in retrospective investigations. However, extracting RNA from archived FFPE tissues is a challenging procedure, as it requires time and the use of complex extraction methods.

Immunohistochemical expression of thymidylate synthase and prognosis in gastric cancer patients submitted to fluoropyrimidine-based chemotherapy.

Objective: Adjuvant chemotherapy with 5-fluorouracil (5-FU) has been widely used in gastric cancer (GC) patients to prevent relapse after curative resection. 5-FU acts by inhibiting thymidylate synthase (TS), and high levels of TS correlate with resistance to treatment with fluoropyrimidines. The aim of this study was to evaluate the expression of TS in GC patients, and its relation with clinicopathological characteristics and prognosis in adjuvant chemotherapy with 5-FU.

Immunohistochemical Assessment of the Expression of Biliary Transportation Proteins MRP2 and MRP3 in Hepatocellular Carcinoma and in Cholangiocarcinoma.

Multidrug resistance-associated protein 2 (MRP2) is a multi-specific organic anion transporter predominantly expressed in the canalicular membrane of hepatocytes, epithelial cells from gallbladder and apical membranes of proximal tubular kidney epithelium whereas multidrug resistance-associated protein 3 (MRP3) is present in the basolateral membrane of hepatocytes and cholangiocytes. This study aims to detect the expression of these transporters in hepatocellular carcinoma (HCC) and in cholangiocarcinoma (CC), searching for evidences for future studies on differential diagnosis and on clinical essays. The immunohistochemical reactivity (IHC) of these transporters was assessed in tissue microarrays of 80 HCC and 56 CC cases using monoclonal antibodies and compared with anatomopathological (AP) variables.

Outbreak of Yellow Fever among Nonhuman Primates, Espirito Santo, Brazil, 2017.

In January 2017, a yellow fever outbreak occurred in Espirito Santo, Brazil, where human immunization coverage is low. Histologic, immunohistologic, and PCR examinations were performed for 22 deceased nonhuman New World primates; typical yellow fever features were found in 21. Diagnosis in nonhuman primates prompted early public health response.

Experimental Zika virus infection induces spinal cord injury and encephalitis in newborn Swiss mice.

A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 in South and Central America, with neurological symptons including meningoencephalitis and Guillain-Barré syndrome in adults, besides an apparent increased incidence of microcephaly in infants born to infected mothers. It is becoming a necessity to have a trustworthy animal model to better understand ZIKV infection. In this study we used newborn white Swiss mice as a model to investigate the ZIKV strain recently isolated in Brazil.

Differential Expression of Stem Cell Markers in Human Adamantinomatous Craniopharyngioma and Pituitary Adenoma.

Background/aims: Although craniopharyngioma (CP) is histologically benign, it is a pituitary tumour that grows rapidly and often recurs. Adamantinomatous CP (ACP) was associated with an activating mutation in β-catenin, and it has been postulated that pituitary stem cells might play a role in oncogenesis in human ACP. Stem cells have also been identified in pituitary adenoma.

Morphologic, molecular and microenvironment factors associated with stromal invasion in breast ductal carcinoma in situ: Role of myoepithelial cells.

Background: Ductal carcinoma in situ is the last step preceding invasive ductal carcinoma in breast carcinogenesis.

Objective: We investigated the role of myoepithelial cells and epithelium characteristics as predictors of the risk of stromal invasion.

Methods: We selected 236 cases with initial diagnosis of DCIS followed by surgical ressection distributed in groups 1 (without invasion) and 2 (with invasive carcinoma).

Carnoy's solution is an adequate tissue fixative for routine surgical pathology, preserving cell morphology and molecular integrity.

Aims: To compare Carnoy's solution (CS) and 10% neutral buffered formalin solution (NBF) as tissue fixatives in colorectal cancer specimens.

Methods And Results: Surgical specimens from patients with colorectal cancer were analysed. Three groups were studied, as follows: group 1 consisted of 16 paired samples fixed in CS and NBF; and groups 2 and 3 consisted of 14 prospective and 80 retrospective samples, respectively, both randomized for fixation in CS or NBF.

Basal cytokeratin as a potential marker of low risk of invasion in ductal carcinoma in situ.

Objectives: Biological markers that predict the development of invasive breast cancer are needed to improve personalized therapy for patients diagnosed with ductal carcinoma in situ. We investigated the role of basal cytokeratin 5/6 in the risk of invasion in breast ductal carcinoma in situ.

Methods: We constructed tissue microarrays using 236 ductal carcinoma in situ samples: 90 pure samples (group 1) and 146 samples associated with invasive carcinoma (group 2).