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. We demonstrated that three doses of DNA plasmid carrying the gene encoding the full-length spike protein (S) or the receptor binding domain (RBD) of SARS-CoV-2 induced a time-dependent increase in IgG antibody avidity maturation. Moreover, the IgG antibodies displayed high cross neutralization by live SARS-CoV-2 and pseudoviruses neutralization assays. Thus, we established a simple, low cost and feasible DNA-based immunization protocol in rabbits that elicited high IgG avidity maturation and nAbs production against SARS-CoV-2, highlighting the importance of DNA-based platforms for developing new immunization strategies against SARS-CoV-2 and future emerging epidemics.

Understanding Sabiá virus infections (Brazilian mammarenavirus).

BACKGROUND: Only two naturally occurring human Sabiá virus (SABV) infections have been reported, and those occurred over 20 years ago. METHODS: We diagnosed two new cases of SABV infection using metagenomics in patients thought to have severe yellow fever and described new features of histopathological findings. RESULTS: We characterized clinical manifestations, histopathology and analyzed possible nosocomial transmission. Patients presented with hepatitis, bleeding, neurological alterations and died. We traced twenty-nine hospital contacts and evaluated them clinically and by RT-PCR and neutralizing antibodies. Autopsies uncovered unique features on electron microscopy, such as hepatocyte "pinewood knot" lesions. Although previous reports with similar New-World arenavirus had nosocomial transmission, our data did not find any case in contact tracing. CONCLUSIONS: Although an apparent by rare, Brazilian mammarenavirus infection is an etiology for acute hemorrhagic fever syndrome. The two fatal cases had peculiar histopathological findings not previously described. The virological diagnosis was possible only by contemporary techniques such as metagenomic assays. We found no subsequent infections when we used serological and molecular tests to evaluate close contacts.

Testicular pathology in fatal COVID-19: A descriptive autopsy study.

BACKGROUND: Multi-organ damage is a common feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, going beyond the initially observed severe pneumonia. Evidence that the testis is also compromised is growing. OBJECTIVE: To describe the pathological findings in testes from fatal cases of COVID-19, including the detection of viral particles and antigens, and inflammatory cell subsets. MATERIALS AND METHODS: Postmortem testicular samples were obtained by percutaneous puncture from 11 deceased men and examined by reverse-transcription polymerase chain reaction (RT-PCR) for RNA detection and by light and electron microscopy (EM) for SARS-CoV-2. Immunohistochemistry (IHC) for the SARS-CoV-2 N-protein and lymphocytic and histiocytic markers was also performed. RESULTS: Eight patients had mild interstitial orchitis, composed mainly of CD68+ and TCD8+ cells. Fibrin thrombi were detected in five cases. All cases presented congestion, interstitial edema, thickening of the tubular basal membrane, decreased Leydig and Sertoli cells with reduced spermatogenesis, and strong expression of vascular cell adhesion molecule (VCAM) in vessels. IHC detected SARS-Cov-2 antigen in Leydig cells, Sertoli cells, spermatogonia, and fibroblasts in all cases. EM detected viral particles in the cytoplasm of fibroblasts, endothelium, Sertoli and Leydig cells, spermatids, and epithelial cells of the rete testis in four cases, while RT-PCR detected SARS-CoV-2 RNA in three cases. DISCUSSION AND CONCLUSION: The COVID-19-associated testicular lesion revealed a combination of orchitis, vascular changes, basal membrane thickening, Leydig and Sertoli cell scarcity, and reduced spermatogenesis associated with SARS-CoV-2 local infection that may impair hormonal function and fertility in men.

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

From 2016 to 2018, an epidemic wave of yellow fever (YF) occurred in Brazil, affecting a large number of Platyrrhini monkeys. Titi monkeys (Callicebus spp.) were severely affected yet pathological characterizations are lacking. This study characterized epizootic YF in 43 titi monkeys (Callicebus spp.) with respect to the microscopic lesions in liver, kidney, spleen, heart, brain, and lung, as well as the distribution of immunolabeling for YF virus antigen, and the flaviviral load in the liver. Of 43 titi monkeys examined, 18 (42%) were positive for yellow fever virus (YFV) by immunohistochemistry or reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR). Affected livers had consistent marked panlobular necrotizing hepatitis, lipidosis, and mild inflammation, with intense immunolabeling for YFV mainly in centrilobular hepatocytes (zone 1; P = .05). In the spleen, consistent findings were variable lymphoid depletion (10/11), lymphoid necrosis (lymphocytolysis; 4/11), and immunolabeling for YFV in histiocytic cells (3/16). The main finding in the kidney was multifocal acute necrosis of tubular epithelium (5/7) that was occasionally associated with intracytoplasmic immunolabeling for YFV (6/15). These data indicate that titi monkeys are susceptible to YFV infection, developing severe hepatic lesions and high viral loads, comparable to humans and Alouatta spp. Thus, Callicebus spp. may be reliable sentinels for YF surveillance.

Differential Yellow Fever Susceptibility in New World Nonhuman Primates, Comparison with Humans, and Implications for Surveillance.

A major outbreak of yellow fever (YF) occurred in Brazil during 2016-2018. Epizootics in New World nonhuman primates are sentinel events for YF virus circulation. However, genus-specific susceptibilities and suitability for YF surveillance remain poorly understood. We obtained and compared epidemiologic, histopathologic, immunohistochemical, and molecular results from 93 human and 1,752 primate cases submitted during the recent YF outbreak in Brazil (2017), with the support of the Brazilian National YF Surveillance Program. We detected heterogeneous YF-associated profiles among the various genera of primates we analyzed. Alouatta primates were the most reliable sentinel; Sapajus and Callicebus primates had higher viral loads but lower proportional mortality rates. Callithrix primates were the least sensitive, showing lower viral loads, lower proportional mortality rates, and no demonstrable YF virus antigen or extensive lesions in liver, despite detectable viral RNA. These differences in susceptibility, viral load, and mortality rates should be considered in strategic surveillance of epizootics and control measures for YF.

The Pathology of Cetacean Morbillivirus Infection and Comorbidities in Guiana Dolphins During an Unusual Mortality Event (Brazil, 2017-2018).

Cetacean morbillivirus (CeMV; Paramyxoviridae) is the most significant pathogen of cetaceans worldwide. The novel "multi-host" Guiana dolphin (Sotalia guianensis; GD)-CeMV strain is reported in South American waters and infects Guiana dolphins and southern right whales (Eubalaena australis). This study aimed to describe the pathologic findings, GD-CeMV viral antigen distribution and detection by RT-PCR (reverse transcriptase polymerase chain reaction), and infectious comorbidities in 29 Guiana dolphins that succumbed during an unusual mass-mortality event in Rio de Janeiro state, Brazil, between November 2017 and March 2018. The main gross findings were lack of ingesta, pulmonary edema, ascites, icterus, hepatic lipidosis, multicentric lymphadenomegaly, as well as pneumonia, polyserositis, and multiorgan vasculitis caused by Halocercus brasiliensis. Microscopically, the primary lesions were bronchointerstitial pneumonia and multicentric lymphoid depletion. The severity and extent of the lesions paralleled the distribution and intensity of morbilliviral antigen. For the first time in cetaceans, morbilliviral antigen was detected in salivary gland, optic nerve, heart, diaphragm, parietal and visceral epithelium of glomeruli, vulva, and thyroid gland. Viral antigen within circulating leukocytes suggested this as a mechanism of dissemination within the host. Comorbidities included disseminated toxoplasmosis, mycosis, ciliated protozoosis, and bacterial disease including brucellosis. These results provide strong evidence for GD-CeMV as the main cause of this unusual mass-mortality event.

Yellow fever and orthotopic liver transplantation: new insights from the autopsy room for an old but re-emerging disease.

AIMS: The clinical spectrum of yellow fever (YF) ranges from asymptomatic to fulminant hepatitis. During the sylvatic YF epidemic in the metropolitan area of São Paulo, Brazil in 2018, seven orthotopic liver transplantations (OLTs) were performed in our institution to treat fulminant YF hepatitis. Three patients recovered, while four patients died following OLT. The autopsy findings of all these cases are presented herein as the first description of YF in transplanted patients. METHODS AND RESULTS: All patients were men, aged 16-40 years, without vaccination to YF virus (YFV). All organs were examined, with tissue sampling for histopathological analysis. Detection of YF virus antigens (YFV Ag) was performed with two primary antibodies (mouse polyclonal anti-YFV antibody directed to wild strain and a goat anti-YF virus antibody), and RT-PCR assays were utilised to detect YFV-RNA. All the cases depicted typical findings of YF hepatitis in the engrafted liver. The main extrahepatic findings were cerebral oedema, pulmonary haemorrhage, pneumonia, acute tubular necrosis and ischaemic/reperfusion pancreatitis. Of the four cases, the YVF Ag was detected in the heart in one case, liver and testis in three cases, and the kidney and spleen in all four cases. All four cases had YF virus RNA detected by RT-PCR in the liver and in other organs. CONCLUSIONS: Infection of the engrafted liver and other organs by YFV, possibly combined with major ischaemic systemic lesions, may have led to the death of four of the seven patients undergoing OLT.

Comparative Immunopathology of Cetacean morbillivirus Infection in Free-Ranging Dolphins From Western Mediterranean, Northeast-Central, and Southwestern Atlantic.

Cetacean morbillivirus (CeMV; Paramyxoviridae) causes epizootic and interepizootic fatalities in odontocetes and mysticetes worldwide. Studies suggest there is different species-specific susceptibility to CeMV infection, with striped dolphins (Stenella coeruleoalba), bottlenose dolphins (Tursiops truncatus), and Guiana dolphins (Sotalia guianensis) ranking among the most susceptible cetacean hosts. The pathogenesis of CeMV infection is not fully resolved. Since no previous studies have evaluated the organ-specific immunopathogenetic features of CeMV infection in tissues from infected dolphins, this study was aimed at characterizing and comparing immunophenotypic profiles of local immune responses in lymphoid organs (lymph nodes, spleen), lung and CNS in CeMV-molecularly (RT-PCR)-positive cetaceans from Western Mediterranean, Northeast-Central, and Southwestern Atlantic. Immunohistochemical (IHC) analyses targeted molecules of immunologic interest: caspase 3, CD3, CD20, CD57, CD68, FoxP3, MHCII, Iba1, IFNγ, IgG, IL4, IL10, lysozyme, TGFß, and PAX5. We detected consistent CeMV-associated inflammatory response patterns. Within CNS, inflammation was dominated by CD3+ (T cells), and CD20+ and PAX5+ (B cells) lymphocytes, accompanied by fewer Iba1+, CD68+, and lysozyme+ histiocytes, mainly in striped dolphins and bottlenose dolphins. Multicentric lymphoid depletion was characterized by reduced numbers of T cells and B cells, more pronounced in Guiana dolphins. Striped dolphins and bottlenose dolphins often had hyperplastic (regenerative) phenomena involving the aforementioned cell populations, particularly chronically infected animals. In the lung, there was mild to moderate increase in T cells, B cells, and histiocytes. Additionally, there was a generalized increased expression of caspase 3 in lymphoid, lung, and CNS tissues. Apoptosis, therefore, is believed to play a major role in generalized lymphoid depletion and likely overt immunosuppression during CeMV infection. No differences were detected regarding cytokine immunoreactivity in lymph nodes, spleen, and lung from infected and non-infected dolphins by semiquantitative analysis; however, there was striking immunoreactivity for IFNγ in the CNS of infected dolphins. These novel results set the basis for tissue-specific immunophenotypic responses during CeMV infection in three highly susceptible delphinid species. They also suggest a complex interplay between viral and host's immune factors, thereby contributing to gain valuable insights into similarities, and differences of CeMV infection's immunopathogenesis in relation to body tissues, CeMV strains, and cetacean hosts.

Comparative histopathologic and viral immunohistochemical studies on CeMV infection among Western Mediterranean, Northeast-Central, and Southwestern Atlantic cetaceans.

Cetacean morbillivirus (CeMV) is a major natural cause of morbidity and mortality in cetaceans worldwide and results in epidemic and endemic fatalities. The pathogenesis of CeMV has not been fully elucidated, and questions remain regarding tissue tropism and the mechanisms of immunosuppression. We compared the histopathologic and viral immunohistochemical features in molecularly confirmed CeMV-infected Guiana dolphins (Sotalia guianensis) from the Southwestern Atlantic (Brazil) and striped dolphins (Stenella coeruleoalba) and bottlenose dolphins (Tursiops truncatus) from the Northeast-Central Atlantic (Canary Islands, Spain) and the Western Mediterranean Sea (Italy). Major emphasis was placed on the central nervous system (CNS), including neuroanatomical distribution of lesions, and the lymphoid system and lung were also examined. Eleven Guiana dolphins, 13 striped dolphins, and 3 bottlenose dolphins were selected by defined criteria. CeMV infections showed a remarkable neurotropism in striped dolphins and bottlenose dolphins, while this was a rare feature in CeMV-infected Guiana dolphins. Neuroanatomical distribution of lesions in dolphins stranded in the Canary Islands revealed a consistent involvement of the cerebrum, thalamus, and cerebellum, followed by caudal brainstem and spinal cord. In most cases, Guiana dolphins had more severe lung lesions. The lymphoid system was involved in all three species, with consistent lymphoid depletion. Multinucleate giant cells/syncytia and characteristic viral inclusion bodies were variably observed in these organs. Overall, there was widespread lymphohistiocytic, epithelial, and neuronal/neuroglial viral antigen immunolabeling with some individual, host species, and CeMV strain differences. Preexisting and opportunistic infections were common, particularly endoparasitism, followed by bacterial, fungal, and viral infections. These results contribute to understanding CeMV infections in susceptible cetacean hosts in relation to factors such as CeMV strains and geographic locations, thereby establishing the basis for future neuro- and immunopathological comparative investigations.

Fatal toxoplasmosis in a southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil: Pathological, immunohistochemical, and molecular characterization.

We report the pathological, immunohistochemical, and molecular features of fatal acute systemic toxoplasmosis in an adult, female, free-living southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil. PCR-RFLP genotyping analysis identified the #21 genotype of Toxoplasma gondii. This represents the first report of acute toxoplasmosis involving this genotype in humans and animals.

Fatal toxoplasmosis in a southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil: Pathological, immunohistochemical, and molecular characterization

We report the pathological, immunohistochemical, and molecular features of fatal acute systemic toxoplasmosis in an adult, female, free­living southern muriqui (Brachyteles arachnoides) from São Paulo state, Brazil. PCR­RFLP genotyping analysis identified the #21 genotype of Toxoplasma gondii. This represents the first report of acute toxoplasmosis involving this genotype in humans and animals.

Relatamos as características patológicas, imuno-histoquímicas e moleculares da toxoplasmose sistêmica aguda fatal em um muriqui do sul adulto (feminino) de vida livre (Brachyteles arachnoides) do estado de São Paulo, Brasil. A análise de genotipagem por PCR ­ RFLP identificou o genótipo # 21 de Toxoplasma gondii. Isso representa o primeiro relato de toxoplasmose aguda envolvendo esse genótipo em humanos e animais

Comparative study of five commercial probes for the detection of Epstein-Barr virus (EBV) by in situ hybridization in cases of nodular sclerosis Hodgki's lymphoma / Estudo comparativo de cinco sondas comerciais para detecção do vírus Epstein-Barr (EBV) por hibridização in situ em casos de linfoma de Hodgkin esclerose nodular

ABSTRACT Introduction: Epstein-Barr virus (EBV) may serve as a target in therapeutic treatments, thus reliable diagnostic results are necessary. Objective: The aim of this study was to evaluate the accuracy of EBV detection by in situ hybridization (ISH) using five commercial probes in formalin-fixed and paraffin-embedded samples of nodular sclerosis Hodgkin's lymphoma (HL), and to compare the results with immunohistochemistry (IHC) and polymerase chain reaction (PCR). Material and method: Thirty samples were selected, 28 were lymph nodes, one bone marrow and one mediastinum. The following parameters were analyzed: signal intensity; proportionality of positive cells; quality of the reaction according to comfort for evaluation, sign quality and homogeneity of labeled cells; background reaction; morphology; presence of artifacts; and positivity in other non-neoplastic cells. All samples were analyzed for EBV detection using the five probes, IHC for latent membrane protein type 1 (LMP1) and PCR for Epstein Barr virus nuclear antigen 1 (EBNA1). Statistical analyses were performed with the R1 software; Fleiss' test and Cohen Kappa index of 5% were considered significant. Results: The detection by IHC-LMP1 was 26.7% (8/30) and 66.7% (20/30) by PCR-EBNA1. All probes detected EBV. Positivity was observed in 42/90 (46.7%), 38/90 (42.2%), 45/90 (50%), 27/90 (30%) and 61/90 (67.8%) for probes A, B, C, D and E, respectively. Discussion: All five probes demonstrated positivity. Conclusion: Probe E showed better rate (67.8%), sensitivity, specificity and accuracy (100%), a very good correlation among the different observers and with PCR, besides great cost-benefits relation.

RESUMO Introdução: O vírus Epstein-Barr (EBV) pode servir como alvo nos tratamentos terapêuticos, sendo necessário resultado diagnóstico confiável. Objetivo: Avaliar a acurácia da detecção do EBV pela hibridização in situ (ISH), utilizando cinco sondas comerciais em amostras fixadas em formalina e incluídas em parafina de linfoma de Hodgkin (LH) esclerose nodular, comparando os resultados com a imuno-histoquímica (IHQ) e a reação em cadeia pela polimerase (PCR). Material e método: Trinta amostras foram selecionadas, sendo 28 linfonodos, uma medula óssea e um mediastino. Os seguintes parâmetros foram analisados: intensidade do sinal; proporcionalidade das células positivas; qualidade da reação de acordo com o conforto na avaliação, qualidade do sinal e homogeneidade das células marcadas; reação de fundo; morfologia; presença de artefatos; e positividade em outras células não neoplásicas. Todas as amostras foram analisadas para a detecção do EBV usando as cinco sondas, IHQ para proteína da membrana latente tipo 1 (LMP1) e PCR para antígeno nuclear do EBV (EBNA1). As análises estatísticas foram realizadas com o software R1; os índices de 5% para Kappa de Fleiss e Cohen foram considerados significantes. Resultados: A detecção pela IHQ-LMP1 foi de 26,7% (8/30) e 66,7% (20/30) pela PCR-EBNA1. Todas as sondas detectaram EBV. A positividade foi observada em 42/90 (46,7%), 38/90 (42,2%), 45/90 (50%), 27/90 (30%) e 61/90 (67,8%) para as sondas A, B, C, D e E, respectivamente. Discussão: Todas as sondas demonstraram positividade. Conclusão: A sonda E mostrou melhor taxa (67,8%), sensibilidade, especificidade e precisão (100%), boa correlação entre os diferentes observadores e com a PCR, além de ótimo custo/benefício.

Phylogeography of Rickettsia rickettsii genotypes associated with fatal Rocky Mountain spotted fever.

Rocky Mountain spotted fever (RMSF), a tick-borne zoonosis caused by Rickettsia rickettsii, is among the deadliest of all infectious diseases. To identify the distribution of various genotypes of R. rickettsii associated with fatal RMSF, we applied molecular typing methods to samples of DNA extracted from formalin-fixed, paraffin-embedded tissue specimens obtained at autopsy from 103 case-patients from seven countries who died of RMSF. Complete sequences of one or more intergenic regions were amplified from tissues of 30 (29%) case-patients and revealed a distribution of genotypes consisting of four distinct clades, including the Hlp clade, regarded previously as a non-pathogenic strain of R. rickettsii. Distinct phylogeographic patterns were identified when composite case-patient and reference strain data were mapped to the state and country of origin. The phylogeography of R. rickettsii is likely determined by ecological and environmental factors that exist independently of the distribution of a particular tick vector.

Fulminant encephalitis associated with a vaccine strain of rubella virus.

Involvement of the central nervous system is common in measles, but rare in rubella. However, rubella virus (RV) can cause a variety of central nervous system syndromes, including meningitis, encephalitis, Guillain-Barré syndrome and sub acute sclerosing panencephalitis. We report the occurrence of one fatal case of the encephalitis associated with measles-rubella (MR) vaccine during an immunization campaign in São Paulo, Brazil. A 31 year-old-man, previously in good health, was admitted at emergency room, with confusion, agitation, inability to stand and hold his head up. Ten days prior to admission, he was vaccinated with combined MR vaccine (Serum Institute of India) and three days later he developed 'flu-like' illness with fever, myalgia and headache. Results of clinical and laboratory exams were consistent with a pattern of viral encephalitis. During hospitalization, his condition deteriorated rapidly with tetraplegia and progression to coma. On the 3rd day of hospitalization he died. Histopathology confirmed encephalitis and immunohistochemistry was positive for RV on brain tissue. RV was also detected by qPCR and virus isolation in cerebrospinal fluid, brain and other clinical samples. The sequence obtained from the isolated virus was identical to that of the RA 27/3 vaccine strain.

Rhabdomyosarcoma in a yellow-headed caracara (Milvago chimachima).

Rhabdomyosarcoma is a malignant tumor originating from rhabdomyoblasts that is rarely reported in domestic animals or in free-living and pet birds. This paper presents a case of rhabdomyosarcoma in a free-ranging yellow-headed caracara (Milvago chimachima), originating from the muscle region of proximal left humerus, with metastases in the left pectoral muscles, heart, lungs, and proventriculus. The cytology was suggestive of rhabdomyosarcoma because of malignant features and cytoplasmic cross-striations in cells. The histopathologic examination revealed neoplastic proliferation composed of spindle cells arranged in irregular sheets or bundles with marked cellular pleomorphism, moderate mitotic ratio, and multinucleated giant cells. Some neoplastic cells also presented evidence of scant cytoplasmic cross-striations visible at histologic sections stained by hematoxylin and eosin and phosphotungstic acid hematoxylin. Immunohistochemically, tumors cells were positive for desmin and negative for alpha-smooth muscle actin and S100 protein.

A molecular analysis and long-term follow-up of two siblings with severe congenital hypothyroidism carrying the IVS30+1G>T intronic thyroglobulin mutation / Análise molecular e acompanhamento a longo prazo de dois irmãos com hipotireoidismo congênito portadores da mutação intrônica IVS30+1G>T no gene da tireoglobulina

OBJECTIVE: To extend the molecular analysis of the IVS30+1G>T intronic thyroglobulin (TG) mutation, and to report the eleven year follow-up of the affected patients. METHOSD: Two siblings with severe congenital hypothyroidism with fetal and neonatal goiter, harboring the IVS30+1G>T mutation were included. Nodular and non-nodular thyroid tissue specimens were collected. Specific thyroid genes expression was evaluated by real-timePCR and by immunohistochemistry. RESULTS: In non-nodular tissue specific thyroid genes mRNA were reduced when compared to normal thyroid sample. In the nodule, TPO and NIS expression was very low. Microscopic examinations showed very large follicular-lumina and swollen vesicles of endoplasmatic-reticulum. Strong cytoplasmatic and low follicular-lumen TG immunostaining were detected. Intracellular NIS, membrane TPO and TSHR immunostaining had higher positivity in non-nodular sample. Both patients had a long-term adequate developmental outcome, besides one patient have been lately-treated. CONCLUSIONS: IVS30+1G>T mutation not only lead to very enlarge endoplasmatic-reticulum, but also to alterations of specific thyroid genes expression. The clinical evolution of patients harboring these mutations strengthen the concept of the influence of environment, like iodine nutrition, to determine the final phenotypic appearance.

OBJETIVO: Aprofundar a análise molecular da mutação intrônica IVS30+1G>T do gene tireoglobulina (TG) e relatar a clínica de pacientes portadores da mutação, acompanhados por 11 anos. MÉTODOS: Foram estudados dois irmãos com hipotireoidismo congênito grave com bócio fetal e bócio neonatal, portadores da mutação IVS30+1G>T. Foram coletadas amostras de tecido nodular e não-nodular. Avaliou-se a expressão de genes específicos da tireóide por PCR em tempo real e imunohistoquímica. RESULTADOS: A expressão de genes específicos da tireóide foi menor no tecido não-nodular que no tecido normal controle. Expressões de TPO e NIS foram extremamente baixas no tecido nodular. Verificou-se lúmen folicular aumentado com grandes vesículas de retículo endoplasmático, e detectou-se forte marcação de TG no citoplasma e fraca no lúmen folicular. No tecido não-nodular observou-se forte positividade de NIS intracelular e, TPO e TSHR na membrana plasmática. O acompanhamento em longo prazo dos pacientes mostrou adequado desenvolvimento, apesar de um deles ter recebido tratamento tardio. CONCLUSÕES: A mutação IVS30+1G>T não só promove alterações no retículo endoplasmático, como alterações na expressão de genes específicos da tireóide. A evolução clínica destes pacientes reforça o conceito da influência do meio ambiente, como o aporte nutricional de iodo, no fenótipo final.

Association of low sodium-iodide symporter messenger ribonucleic acid expression in malignant thyroid nodules with increased intracellular protein staining.

CONTEXT: The expression of sodium iodide symporter (NIS) is required for iodide uptake in thyroid cells. Benign and malignant thyroid tumors have low iodide uptake. However, previous studies by RT-PCR or immunohistochemistry have shown divergent results of NIS expression in these nodules. OBJECTIVE: The objective of the study was to investigate NIS mRNA transcript levels, compare with NIS and TSH receptor proteins expression, and localize the NIS protein in thyroid nodules samples and their surrounding nonnodular tissues (controls). DESIGN: NIS mRNA levels, quantified by real-time RT-PCR, and NIS and TSH receptor proteins, evaluated by immunohistochemistry, were examined in surgical specimens of 12 benign and 13 malignant nodules and control samples. RESULTS: When compared with controls, 83.3% of the benign and 100% of the malignant nodules had significantly lower NIS gene expression. Conversely, 66.7% of the benign and 100% of malignant nodules had stronger intracellular NIS immunostaining than controls. Low gene expression associated with strong intracellular immunostaining was most frequently detected in malignant (100%) than benign nodules (50%; P = 0.005). NIS protein was located at the basolateral membrane in 24% of the control samples, 8.3% of the benign, and 15.4% of the malignant nodules. The percentage of benign nodules with strong TSH receptor positivity (41.6%) was higher than malignant (7.7%). CONCLUSION: We confirmed that reduced NIS mRNA expression in thyroid malignant nodules is associated with strong intracellular protein staining and may be related to the inability of the NIS protein to migrate to the cellular basolateral membrane. These results may explain the low iodide uptake of malignant nodules.

A molecular analysis and long-term follow-up of two siblings with severe congenital hypothyroidism carrying the IVS30+1G>T intronic thyroglobulin mutation.

OBJECTIVE: To extend the molecular analysis of the IVS30+1G>T intronic thyroglobulin (TG) mutation, and to report the eleven year follow-up of the affected patients. METHOSD: Two siblings with severe congenital hypothyroidism with fetal and neonatal goiter, harboring the IVS30+1G>T mutation were included. Nodular and non-nodular thyroid tissue specimens were collected. Specific thyroid genes expression was evaluated by real-timePCR and by immunohistochemistry. RESULTS: In non-nodular tissue specific thyroid genes mRNA were reduced when compared to normal thyroid sample. In the nodule, TPO and NIS expression was very low. Microscopic examinations showed very large follicular-lumina and swollen vesicles of endoplasmatic-reticulum. Strong cytoplasmatic and low follicular-lumen TG immunostaining were detected. Intracellular NIS, membrane TPO and TSHR immunostaining had higher positivity in non-nodular sample. Both patients had a long-term adequate developmental outcome, besides one patient have been lately-treated. CONCLUSIONS: IVS30+1G>T mutation not only lead to very enlarge endoplasmatic-reticulum, but also to alterations of specific thyroid genes expression. The clinical evolution of patients harboring these mutations strengthen the concept of the influence of environment, like iodine nutrition, to determine the final phenotypic appearance.

Proliferative lesions of prostate: a multivariate approach to differential diagnosis.

Prostatic needle biopsies from 142 patients were studied: 61 cases were "benign", 19 atypical small acinar proliferation, 31 high-grade prostatic intraepithelial neoplasia, and 31 adenocarcinoma. Using univariate analysis of 46 previously described morphological features, 16 variables were selected, which were followed by multivariate discriminant analysis. Of these parameters, seven (glandular fusion, crystalloids, nucleolomegaly, papillary architecture, visibility of basal cell layer, areas of normal luminal cell nucleus/cytoplasm ratio and areas of high luminal cell nucleus/cytoplasm ratio) remained significant in discriminating the groups. Multivariate analysis selected a small panel of histological features as those most helpful in the differential diagnosis of proliferative lesions in prostate biopsies.

Expressão de galectina-3 e citoqueratina 19 nas neoplasias epiteliais da glândula tireóidea e correlação histopatológica / Expression of galectin-3 and cytokeratin 19 in the epithelial neoplasm of the thyroid gland and histopathological correlation

INTRODUÇAO: O câncer da glândula tireóidea é caracterizado pela sua variedade clínica e patológica. O difícil diagnóstico pré-operatório das lesões foliculares induz a mais procedimentos cirúrgicos de caráter diagnóstico do que propriamente terapêutico. A proposta deste estudo foi identificar a expressão imuno-histoquímica das neoplasias epiteliais tireóideas utilizando anticorpos monoclonais para galectina-3 e citoqueratina 19 e correlacioná-la com variáveis histopatológicas. MATERIAL E MÉTODO: A expressão da galectina-3 e da citoqueratina 19 foi estudada imuno-histoquimicamente em 84 casos com diagnóstico de tecido normal (n = 10), bócio adenomatoso (n = 8), adenoma folicular (n = 12), adenoma de célula de Hürthle (n = 3), carcinoma papilífero (n = 29), carcinoma folicular (n = 8), carcinoma insular (n = 4), carcinoma de células de Hürthle (n = 4) e carcinoma indiferenciado (n = 6), selecionados a partir de pacientes operados no Serviço de Cirurgia de Cabeça e Pescoço do Hospital Heliópolis (HOSPHEL), no período de 1984 a 1995. RESULTADOS: A expressão da galectina-3 foi observada em bócio adenomatoso (12,5 por cento), adenoma folicular (16,7 por cento), carcinoma papilífero (96,6 por cento), carcinoma folicular (12,5 por cento), carcinoma insular (50 por cento), carcinoma de célula de Hürthle (100 por cento) e carcinoma indiferenciado (50 por cento). Nossos resultados confirmaram a expressão significativa da galectina-3 no grupo das neoplasias malignas, principalmente no carcinoma papilífero. O padrão de expressão da citoqueratina 19 foi diferente entre os tipos de lesão: enquanto nos bócios e adenomas mostrou-se fraco, nos carcinomas papilíferos foi forte e difuso. CONCLUSAO: Associadas, a galectina-3 e a citoqueratina 19 auxiliam o diagnóstico histopatológico, principalmente nas lesões de interpretação duvidosa, além de evidenciarem atipias e, com isso, determinarem uma lesão suspeita.