Liver disease accompanied by enteropathy in common variable immunodeficiency: Common pathophysiological mechanisms.

Common variable immunodeficiency (CVID) is one of the inborn errors of immunity that have the greatest clinical impact. Rates of morbidity and mortality are higher in patients with CVID who develop liver disease than in those who do not. The main liver disorder in CVID is nodular regenerative hyperplasia (NRH), the cause of which remains unclear and for which there is as yet no treatment. The etiology of liver disease in CVID is determined by analyzing the liver injury and the associated conditions. The objective of this study was to compare CVID patients with and without liver-spleen axis abnormalities in terms of clinical characteristics, as well as to analyze liver and duodenal biopsies from those with portal hypertension (PH), to elucidate the pathophysiology of liver injury. Patients were divided into three groups: Those with liver disease/PH, those with isolated splenomegaly, and those without liver-spleen axis abnormalities. Clinical and biochemical data were collected. Among 141 CVID patients, 46 (32.6%) had liver disease/PH; 27 (19.1%) had isolated splenomegaly; and 68 (48.2%) had no liver-spleen axis abnormalities. Among the liver disease/PH group, patients, even those with mild or no biochemical changes, had clinical manifestations of PH, mainly splenomegaly, thrombocytopenia, and esophageal varices. Duodenal celiac pattern was found to correlate with PH (p < 0.001). We identified NRH in the livers of all patients with PH (n = 11). Lymphocytic infiltration into the duodenal mucosa also correlated with PH. Electron microscopy of liver biopsy specimens showed varying degrees of lymphocytic infiltration and hepatocyte degeneration, which is a probable mechanism of lymphocyte-mediated cytotoxicity against hepatocytes and enterocytes. In comparison with the CVID patients without PH, those with PH were more likely to have lymphadenopathy (p < 0.001), elevated ß2-microglobulin (p < 0.001), low B-lymphocyte counts (p < 0.05), and low natural killer-lymphocyte counts (p < 0.05). In CVID patients, liver disease/PH is common and regular imaging follow-up is necessary. These patients have a distinct immunological phenotype that may predispose to liver and duodenal injury from lymphocyte-mediated cytotoxicity. Further studies could elucidate the cause of this immune-mediated mechanism and its treatment options.

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.

Nitro-Heterocyclic compounds induce apoptosis-like effects in Leishmania (L). amazonensis promastigotes.

BACKGROUND: Three drugs - pentavalent antimonials, amphotericin B and pentamidine - are currently used for leishmaniasis treatment. They are administered for long periods, only parenterally, and have high cardiac, renal and hepatic toxicities. Therefore, the investigation of new compounds is required. Nitro-heterocyclic derivatives have been used as possible drug candidates to treat diseases caused by trypanosomatids. METHODS: Leishmania (L.) amazonensis promastigotes (MHO/BR/73/M2269), maintained in the Laboratório de Soroepidemiologia - Instituto de Medicina Tropical- USP, were exposed to five nitroheterocyclic derivatives, with differences at phenyl-ring position 4: BSF-C4H9, BSF-H, BSF-NO2, BSF-CH3 and BSF-Cl, for 48 hours. After analyzing viability (MTT assay), we evaluated cellular-morphology activity of compounds by transmission electron microscopy (TEM) and measurement of apoptosis (phosphatidylserine expression) by flow cytometry. RESULTS: EC50 of amphotericin B and BSF-CH3 were 0.50 (M and 0.39 (M respective. Other nitro-heterocyclic compounds presented EC50 higher than amphotericin B. All compounds showed greater AV- and PI-positive expression than amphotericin B at 100 (M, except BSF-NO2. TEM showed complete nuclear disfigurement with 100 (M of BSF-NO2, 25 and 6.25 (M of BSF-H, and 6.25 (M BSF-Cl; presence of vesicles within the flagellar pocket with 25 (M BSF-H; alteration of the kinetoplast with 25 (M BSF-C4H9, 25 (M of BSF-H, 6.25 (M BSF-CH3 and 6.25 (M of BSF-Cl. CONCLUSIONS: Nitro-heterocyclic compounds have shown activity against promastigotes of L. amazonensis, at lower concentrations. However, improvement of compound scaffolds are needed to assist the elucidation of the mechanism of action and to achieve greater activity.

Nitro-Heterocyclic compounds induce apoptosis-like effects in Leishmania (L). amazonensis promastigotes

Abstract Background: Three drugs - pentavalent antimonials, amphotericin B and pentamidine - are currently used for leishmaniasis treatment. They are administered for long periods, only parenterally, and have high cardiac, renal and hepatic toxicities. Therefore, the investigation of new compounds is required. Nitro-heterocyclic derivatives have been used as possible drug candidates to treat diseases caused by trypanosomatids. Methods: Leishmania (L.) amazonensis promastigotes (MHO/BR/73/M2269), maintained in the Laboratório de Soroepidemiologia - Instituto de Medicina Tropical- USP, were exposed to five nitroheterocyclic derivatives, with differences at phenyl-ring position 4: BSF-C4H9, BSF-H, BSF-NO2, BSF-CH3 and BSF-Cl, for 48 hours. After analyzing viability (MTT assay), we evaluated cellular-morphology activity of compounds by transmission electron microscopy (TEM) and measurement of apoptosis (phosphatidylserine expression) by flow cytometry. Results: EC50 of amphotericin B and BSF-CH3 were 0.50 (M and 0.39 (M respective. Other nitro-heterocyclic compounds presented EC50 higher than amphotericin B. All compounds showed greater AV- and PI-positive expression than amphotericin B at 100 (M, except BSF-NO2. TEM showed complete nuclear disfigurement with 100 (M of BSF-NO2, 25 and 6.25 (M of BSF-H, and 6.25 (M BSF-Cl; presence of vesicles within the flagellar pocket with 25 (M BSF-H; alteration of the kinetoplast with 25 (M BSF-C4H9, 25 (M of BSF-H, 6.25 (M BSF-CH3 and 6.25 (M of BSF-Cl. Conclusions: Nitro-heterocyclic compounds have shown activity against promastigotes of L. amazonensis, at lower concentrations. However, improvement of compound scaffolds are needed to assist the elucidation of the mechanism of action and to achieve greater activity.

Cell death mechanisms in Leishmania amazonensis triggered by methylene blue-mediated antiparasitic photodynamic therapy

Antiparasitic photodynamic therapy (ApPDT) is an emerging approach to manage cutaneous leishmaniasis (CL) since no side effects, contraindications and parasite resistance have been reported. In addition, methylene blue (MB) is a suitable photosensitizer to mediate ApPDT on CL. In this study we aimed to look for the best parameters to eradicate Leishmania amazonensis and investigated the cell death pathways involved in MB-mediated ApPDT. MB uptake by parasites was determined using different MB concentrations (50, 100, 250 and 500 µM) and incubation times (10, 30 and 60 min). L. amazonensis promastigotes were cultured and submitted to ApPDT using different concentrations of MB (50, 100 and 250 µM) combined to a red LED emitting at 645 ±â€¯10 nm. The pre-irradiation time was 10 min. Two optical powers (100 mW and 250 mW) were tested and cells were exposed to 60 and 300 s of MB-mediated ApPDT delivering energies of 6, 15, 30 and 75 J and fluences of 21.2, 53.1, 106.2 and 265.4 J/cm2, respectively. Following ApPDT, cells were prepared for flow cytometry and transmission electron microscopy to unravel the mechanisms of cell death. Our results showed the lowest MB concentration (50 µM) and the lowest optical power (100 mW) promoted the highest percentage of cell decrease. ApPDT caused alterations on cell membrane permeability as well depolarization of mitochondrial membrane potential. We also observed ultrastructural changes of the parasites such as cell shrinkage, intense vacuolization of the cytoplasm, enlargement of mitochondrion-kinetoplast complex, and small blebs on parasite flagella and cell membrane after MB-mediated ApPDT. Taken together, our findings ratify that ApPDT parameters play a pivotal role in cell susceptibility and suggest that apoptosis is involved in parasite death regardless MB-mediated ApPDT protocol

Cell death mechanisms in Leishmania amazonensis triggered by methylene blue-mediated antiparasitic photodynamic therapy.

Antiparasitic photodynamic therapy (ApPDT) is an emerging approach to manage cutaneous leishmaniasis (CL) since no side effects, contraindications and parasite resistance have been reported. In addition, methylene blue (MB) is a suitable photosensitizer to mediate ApPDT on CL. In this study we aimed to look for the best parameters to eradicate Leishmania amazonensis and investigated the cell death pathways involved in MB-mediated ApPDT. MB uptake by parasites was determined using different MB concentrations (50, 100, 250 and 500 µM) and incubation times (10, 30 and 60 min). L. amazonensis promastigotes were cultured and submitted to ApPDT using different concentrations of MB (50, 100 and 250 µM) combined to a red LED emitting at 645 ±â€¯10 nm. The pre-irradiation time was 10 min. Two optical powers (100 mW and 250 mW) were tested and cells were exposed to 60 and 300 s of MB-mediated ApPDT delivering energies of 6, 15, 30 and 75 J and fluences of 21.2, 53.1, 106.2 and 265.4 J/cm2, respectively. Following ApPDT, cells were prepared for flow cytometry and transmission electron microscopy to unravel the mechanisms of cell death. Our results showed the lowest MB concentration (50 µM) and the lowest optical power (100 mW) promoted the highest percentage of cell decrease. ApPDT caused alterations on cell membrane permeability as well depolarization of mitochondrial membrane potential. We also observed ultrastructural changes of the parasites such as cell shrinkage, intense vacuolization of the cytoplasm, enlargement of mitochondrion-kinetoplast complex, and small blebs on parasite flagella and cell membrane after MB-mediated ApPDT. Taken together, our findings ratify that ApPDT parameters play a pivotal role in cell susceptibility and suggest that apoptosis is involved in parasite death regardless MB-mediated ApPDT protocol.

Esophageal mucosa in HIV infection: A"deeper" look at this little spoken organ.

BACKGROUND AND AIM: Although the esophagus is a common site of opportunistic infection in AIDS patients, little is known about the impact of HIV as well as opportunistic infection in the esophageal mucosa. Our aim is to analyze the esophageal immune profile in HIV+ patients with different immunological status with and without the opportunistic Candida infection. METHODS: Immunohistochemistry to CD4+ and CD8+ T-cells, γ-interferon, transforming growth factor-ß, interleukin (IL)-4, IL-6, IL-13, and IL-17 was performed in esophageal samples of 40 chronically HIV+ patients under highly active antiretroviral therapy (16 with Candida esophagitis, 12 virologically non-supressed with blood CD4 count < 500, and 12 virologically suppressed with blood CD4 count > 500; the latter two groups without esophageal candidiasis). The controls were 12 HIV-negative healthy individuals. RESULTS: Esophageal CD4+ T-cell expression in HIV+ patients did not differ from the control group (P = 0.50). Mucosal CD8+ T-cell expression was significantly increased in HIV+ patients (P = 0.0018). Candida esophagitis and virologically non-supressed HIV+ patients with CD4 < 500 showed an increased expression of IL-17 and IL-6 with fewer expressions of γ-interferon, more attenuated in the latter group. Transforming growth factor-ß was increased only in virologically suppressed HIV+ patients with CD4 > 500. IL-4 and IL-13 were similar to the control group. CONCLUSION: In contrast to CD8+ T-cell expression, esophageal CD4+ T-cell expression does not reflect the HIV+ patient's immunological status. T-helper 17 (Th17) response seems to play a role in the esophageal mucosa of virologically non-supressed HIV+ patients with blood CD4 < 500. Candida esophagitis showed a Th1/Th17 response but seems to be dominantly regulated by the Th17 pathway.

Ultrastructure of vascular permeability in urticaria.

BACKGROUND: Few studies have addressed the ultrastructure of vascular permeability in urticaria. OBJECTIVES: To describe the types of endothelial cell organelles involved in vascular permeability in drug-induced acute urticaria (DIAU). METHODS: Seven patients with DIAU were enrolled in the study. Biopsies of urticarial lesions and apparently normal skin were performed. The 14 collected fragmentswere processed with immunogold electron microscopy using single stains for tryptase and factor XIIIa (FXIIIa) and double immunogold labeling for both tryptase and FXIIIa. RESULTS: Some sections demonstrated mast cells in the degranulation process, in both anaphylactic and piecemeal degranulation. After double immunogold staining, 10 nm (FXIIIa) and 15 nm (tryptase) gold particles wereboth present, covering the granules in the mast cells, indicating that both tryptase and FXIIIa were localized within the granules of these cells. Interestingly, we found strong evidence of the presence of caveolae and vesico-vacuolar organelles (VVOs) in the endothelial cells of the biopsies. In addition to these findings, we were able to demonstrate the presence of tryptase and FXIIIa in the endothelial celIs, in urticarial lesions and in apparently normal skin. CONCLUSIONS: VVOs are present in the endothelial cells of post-capillary venules in DIAU. This is the first report on the expression of FXIIIa and tryptase in the cytoplasm of endothelial cells in urticaria.

Immunoelectron microscopy study of superficial skin nerves in drug-induced acute urticaria.

BACKGROUND: Few studies have evaluated the ultrastructure of the superficial skin nerves in urticaria. OBJECTIVE: The objective of this study was to describe findings in superficial skin nerves in cases of drug-induced acute urticaria. METHODS: Seven patients with drug-induced acute urticaria were included in the study. Skin biopsies were obtained from the urticarial lesion and from the apparently normal skin. The 14 fragments collected were processed for immunogold electron microscopy using single stains for antitryptase and anti-FXIIIa antibodies, as well as double immunogold labeling for both. RESULTS: Some sections showed mast cells in the process of degranulation. Following double immunogold staining, 10 nm (FXIIIa) and 15 nm (Tryptase) gold particles were found together throughout the granules in mast cells, indicating that tryptase and FXIIIa are located inside each one of the granules of these cells. Interestingly, we found strong evidence of the presence of tryptase and factor XIIIa in the superficial skin nerves of these patients, both in cases of urticarial lesions (wheals) and in the apparently normal skin. CONCLUSIONS: Tryptase and FXIIIa are present in the superficial nerves of the skin in drug-induced acute urticaria. This is the first report of tryptase and FXIIIa expression in the superficial skin nerves of patients with urticaria. Tryptase may be participating in neural activation in these patients, while FXIIIa may be present in the nerves to guarantee the functional integrity of structures.

Immunoelectron microscopy study of superficial skin nerves in drug-induced acute urticaria / Estudo de microscopia imunoeletrônica dos nervos superficiais da pele na urticária aguda induzida por medicamentos

BACKGROUND: Few studies have evaluated the ultrastructure of the superficial skin nerves in urticaria. OBJECTIVE: The objective of this study was to describe findings in superficial skin nerves in cases of drug-induced acute urticaria. METHODS: Seven patients with drug-induced acute urticaria were included in the study. Skin biopsies were obtained from the urticarial lesion and from the apparently normal skin. The 14 fragments collected were processed for immunogold electron microscopy using single stains for antitryptase and anti-FXIIIa antibodies, as well as double immunogold labeling for both. RESULTS: Some sections showed mast cells in the process of degranulation. Following double immunogold staining, 10 nm (FXIIIa) and 15 nm (Tryptase) gold particles were found together throughout the granules in mast cells, indicating that tryptase and FXIIIa are located inside each one of the granules of these cells. Interestingly, we found strong evidence of the presence of tryptase and factor XIIIa in the superficial skin nerves of these patients, both in cases of urticarial lesions (wheals) and in the apparently normal skin. CONCLUSIONS: Tryptase and FXIIIa are present in the superficial nerves of the skin in drug-induced acute urticaria. This is the first report of tryptase and FXIIIa expression in the superficial skin nerves of patients with urticaria. Tryptase may be participating in neural activation in these patients, while FXIIIa may be present in the nerves to guarantee the functional integrity of structures.

FUNDAMENTOS: Poucos autores têm estudado a ultraestrutura dos nervos superficiais na urticária. OBJETIVO: Descrever os achados nos nervos cutâneos superficiais em casos de urticária aguda induzida por medicamentos. MÉTODOS: Sete pacientes com urticária aguda induzida por medicamentos foram incluídos no estudo. Foram obtidas biopsias da pele da lesão urticariforme e da pele aparentemente normal. Os 14 fragmentos coletados foram processados usando imunomarcação com ouro para anticorpos anti-triptase e anti-FXIIIa separadamente, além da dupla imunomarcação com ambos anticorpos. A seguir as amostras foram submetidas à análise por microscopia imunoeletrônica. RESULTADOS: Alguns cortes demonstraram mastócitos em processo de degranulação. Após a imunomarcação dupla, partículas de ouro de 10 nm (FXIIIa) e partículas de ouro de 15 nm (Triptase) apresentavam-se juntas em grânulos de mastócitos indicando que a triptase e o FXIIIa se localizam dentro de cada um dos grânulos dessas células. Curiosamente, foi encontrada uma forte evidência da presença da triptase e do fator XIIIa nos nervos superficiais dos pacientes avaliados, tanto em lesões urticadas, como na pele aparentemente normal. CONCLUSÕES: A triptase e o FXIIIa estão presentes nos nervos superficiais da pele na urticária aguda medicamentosa. Este é o primeiro relato da expressão de triptase e de FXIIIa nos nervos superficiais na urticária. A triptase poderia estar participando da ativação neural nos pacientes estudados. O FXIIIa poderia estar presente nos nervos, com a finalidade de manter a integridade funcional dessas estruturas.

Diffuse-regressive alterations and apoptosis of myocytes: possible causes of myocardial dysfunction in HIV-related cardiomyopathy.

OBJECTIVE: To determine the frequency of cardiac alterations in necropsies of AIDS patients in pre-HAART era and better understand the pathogenesis of HIV-related cardiomyopathy. DESIGN: Retrospective study of 94 complete necropsies. METHOD: Macroscopic, histopathologic (histochemical, immunohistochemical and in situ hybridization techniques) and ultra structural myocardial evaluation (23 cases). RESULTS: Cardiac alterations were observed in 94.4%; 74% showed variable degrees of cardiac dilation not related to known cardiovascular diseases. Eighty-two percent (81.8%) of patients with biventricular dilation showed diffuse-regressive alterations (thinning and waving cardiomyocytes with increase of lipofuscin pigment granules). Myocarditis was diagnosed in 27 cases (28.7%), 16 (59.3%) of known etiology. The ultra structural study has revealed cardiomyocytes alterations (mitochondriosis, loss of myofibrils, increase in the amount of perinuclear-lipofuscin pigment granules) associated to activation signals of capillary-endothelial cells (enhancement of pseudopodia and transcellular channels). Cardiomyocytes' apoptosis was demonstrated at structural level in 10 (43.5%) patients; tumor necrosis factor alpha (TNF alpha) was detected in 17/18 cases. CONCLUSIONS: This pioneer study described the association of histopathological and ultra structural findings (thinning and waving cardiomyocytes with increase of lipofuscin pigment granules, mitochondriosis and loss of myofibrils) with different degrees of cardiac-chamber dilation probably representing a spectrum of alterations that would lead to myocardial dysfunction and development of HIV-related cardiomyopathy. Cardiomyocytes' apoptosis observed at ultra structural level and demonstration of TNF alpha associated to described alterations suggest that this cytokine plays an important role in both negative-inotropic effect and capacity to induce apoptosis through death receptor-controlled pathway.

Hepatic ultrastructural mitochondrial changes prior to antiretroviral therapy in HIV-infected patients in Brazil.

The use of antiretroviral (ARV) medications has been linked to the emergence of severe adverse effects, including mitochondrial toxicity. The liver also appears to be among the affected organs. Nevertheless, different studies suggest that these patients' mitochondrial alterations could be associated to other etiological factors. The goal of this study was to analyze hepatic mitochondria ultrastructural changes in HIV-infected patients under investigation for hepatopathy. Semiquantitative analysis of mitochondria was performed in liver biopsies from 10 patients divided into 2 groups: Group 1 consisted of 5 patients who had never used ARV medications; group 2 consisted of 5 patients who reported previous use of either zidovudine or didanosine. Significant mitochondrial alterations were found in both groups. The summation of the mitochondrial alterations was higher in group 1 (P < .05) when compared with those who had previously used ARV medications. Therefore, the authors conclude that severe mitochondrial alterations occur in HIV-infected patients who have never been submitted to antiretroviral therapy.

Revisiting the liver in human yellow fever: virus-induced apoptosis in hepatocytes associated with TGF-beta, TNF-alpha and NK cells activity.

Flavivirus infection as dengue and yellow fever persists as a terrible menace to pandemics, due to Aedes prevalence in the Americas. Yellow fever is characterized by hepatocyte damage, with steatosis, apoptosis and necrosis, mainly in the midzonal region of the liver, but the injury mechanism has not been studied at the light of recent knowledge, such as the advances in cell death mechanisms, inflammatory response and cytokine cell expression tools. We studied 53 human liver paraffin embedded blocks from patients who died with yellow fever, all with histological demonstration of higher prevalence of apoptosis over necrosis and mild disproportionate inflammatory response. Viral antigens were found most frequently in hepatocytes from the midzonal area than other lobule areas, as detected by specific immunohistochemistry. Infiltrating cell subpopulations showed mainly CD4+ T lymphocytes, with small numbers of CD8+ cytotoxic lymphocytes, CD20+ B lymphocytes, NKT+ cells and S100+ dendritic cells in the sites of inflammation, as compared to normal and leptospirosis liver blocks. Some cells expressed TNF-alpha and IFN-gamma, but a much more intense proportion of TGF-beta expressing cells were found, suggesting both a Th1 and Th3 patterns of immune response in yellow fever. Most affected hepatocyte presented apoptosis markers that appear at the cell death main pathway in this infection. Viral antigens, which production could interfere in hepatocyte biology, could induce the activation of apoptosis cascade, but TGF-beta was also an apoptosis promoter. Our finding supports the key effect of the yellow fever virus in hepatocyte injury, resulting in prevalence of apoptosis over necrosis, aside from a TGF-beta action induced by the inflammatory response.

Pruritic papular eruption associated with HIV-etiopathogenesis evaluated by clinical, immunohistochemical, and ultrastructural analysis.

Pruritic Papular Eruption with Human Immunodeficiency Virus infection (PPE-HIV) is characterized by symmetrically distributed papules with pruritus in the skin of patients suffering advanced HIV infection. Although known since 1985, the etiology of this symptomatic dermatitis is unclear. We set out to characterize the phenotype of the infiltrating cells and the cytokine profile in the lesions, as an attempt to contribute to determining its etiopathogenesis. Clinical data and histological, immunohistochemical, and ultrastructural features of skin biopsies from 20 HIV patients with PPE were studied. The histopathological aspects, cell immunophenotypes, and cytokine expressions in the lesions where quantified and compared to perilesional skin, and to those in the clinically normal skin of HIV patients without PPE-HIV (n=11) and those in normal skin samples from HIV negative individuals (n=10). PPE-HIV occurred mainly in HIV patients with mean CD4+ counts of 124.6 +/- 104 lymphocytes/mm3. Furthermore, their eosinophil counts were significantly increased. The skin lesions were characterized by a predominantly perivascular dermal lymphohistiocytic inflammatory infiltrate. Langerhans cells were normally distributed in the epidermis and seen among the cellular components of dermal infiltrates. The density of CD8+ lymphocytes was elevated and the density of CD4+ cells was reduced in dermal infiltrates. Interleukin 5 was the predominant cytokine in the lesions. Electron microscopic analysis didn't disclose HIV or other infectious agents in the lesions. These results refute the hypothesis of an infectious etiology of PPE-HIV. CD8+ lymphocytes and Langerhans cells seem to have roles in the pathogenesis of PPE-HIV. The increased frequency of IL5 was associated with abundant eosinophils in the lesions, suggesting a type Th2 response in this dermatitis.

Reconsideration of histopathology and ultrastructural aspects of the human liver in yellow fever.

Yellow fever is a re-emerging infectious disease that currently is at risk of urbanization due to the advance of the Aedes aegypti vector. The disease affects about 200,000 individuals annually, mainly in tropical Africa and South America. It causes severe disease involving especially the liver, with lesions characterized by midzonal steatosis, apoptosis and lytic necrosis of the hepatocytes. Quantitative histological and immunohistochemical analysis of 53 human hepatic samples demonstrated apoptosis, steatosis and lytic necrosis of hepatocytes with midzonal pattern. No substantial alterations and reticular network were observed. The inflammatory infiltrate consisted of mononuclear cells and intensity was minimal or moderate, disproportionate to the intense death of the hepatocytes. Hepatic damage in yellow fever resulted mainly from a massive death of hepatocytes due to apoptosis and to a lesser extent due to lytic necrosis. It is recommended that therapeutic regimens for serious cases should include measures to protect against apoptosis.

Ultrastructural study of the pancreas in AIDS.

INTRODUCTION: Frequent histologic changes (90%) in the pancreas suggesting protein-energy malnutrition were found in a previous necropsy study of pancreas morphology in patients with AIDS. However, additional studies were required to clarify subcellular changes. AIM: To ultrastructurally analyze pancreas changes in AIDS patients through transmission electron microscopy. METHODOLOGY AND RESULTS: Pancreas specimens for necropsy were obtained from nine consecutive AIDS patients and four normal controls. A semiquantitative histologic and ultrastructural analysis of exocrine pancreas was carried out with the following findings: preserved pancreas structure with little autolysis, marked decrease in zymogen granules (100%), increased lipofuscin pigment (80%), augmented and dilated rough endoplasmic reticulum (100%), and increased number and size of mitochondria. The Golgi complex could be identified only in two cases. In all cases, acinar nuclei were decreased in size, with peripherally condensed chromatin and undulated membrane suggesting early apoptosis. In addition, immunohistochemical evaluation of the pancreas was carried out to detect opportunistic agents. CONCLUSION: Decreased zymogen granules, acinar atrophy, increased lipofuscin pigment, and rarefying Golgi complex represent the morphologic substrate of protein-energy malnutrition in AIDS patients. The combination of rough endoplasmic reticulum and mitochondria changes could be due to the need for supplying vital plasma proteins rather than exportation protein synthesis associated, or not, with the deleterious effects of inflammatory cytokines and/or therapy for disease.

Imunomapeamento no diagnóstico das epidermólises bolhosas hereditárias distróficas / Immunomapping in the diagnosis of hereditary epidermolysis bullosa dystrophica

O objetivo deste estudo é mostrar as vantagens da técnica de imunomapeamento no diagnóstico das epidermólises bolhosas distróficas. Dos 37 doentes estudados realizou-se 28 exames anatomopatológicos, 23 exames de microscopia eletrônica de transmissão e 37 imunomapeamentos. Dos exames histopatológicos 3 foram compatíveis com epidermólise bolhosa simples (EBS) e 25 com os grupos das epidermólises bolhosas juncionais (EBJ) e das epidermólises bolhosas distróficas (EBD). Dos 19 exames de microscopia eletrônica de transmissão representativos, 2 foram compatíveis com EBS, 1 com EBJ e 16 com EBD. Nos imunomapeamentos 3 foram compatíveis com EBS, 3 com EBJ, 14 com EBD dominante (EBBD) e 17 com EBD recessiva (EBDR). O imunomapeamento pôde fazer a diferenciação dos dois grupos das EBD de forma mais fácil e de custo inferior ao da MET. Sabe-se que essa diferenciação pode ser feita pela MET, no entanto exige avaliação morfológica e quantificação das fibrilas de ancoragem, tornando esta técnica difícil, demorada e sujeita e erros por trabalhar com área restrita da zona da membrana basal

Estudo ao microscópico óptico e eletrônico de transmissäo na cicatrizaçäo de feridas produzidas pelo laser de CO2 no palato do rato / Light and transmission electron microscopic study of CO2 laser wound healing on palatine mucosa of rats

Os autores estudaram a cicatrizaçäo de feridas produzidas pelo laser CO2 na mucosa palatina do rato. A cicatrizaçäo ocorreu em uma semana, e a regiäo atingida foi ocupada por tecido conjuntivo neoformado e por epitélio. Foram notados os numerosos leucócitos polimorfonucleares e fibroblastos entre as fibras colágenas neoformadas