High- and low-density lipoproteins enhance infection of Trypanosoma cruzi in vitro

Trypanosoma cruzi exhibits a developmentally regulated neuraminidase activity that is inhibited by high-density lipoprotein (HDL). We report here that the infection of culture cells by T. cruzi trypomastigotes is enhanced by HDL in a dose-dependent manner. The enhanced infection is prevented by Vibrio cholerae neuraminidase, an enzyme whose activity is not inhibited by HDL, suggesting that sialic acid is involved in T. cruzi-host interaction. Similar enhancement of infection is also produced by low-density lipoprotein (LDL), which inhibits T. cruzi neuraminidase as well as HDL. Further evidence that the enhancement is due to lipoproteins is provided by the fact that infection of host cells in lipoprotein-deficient medium is less than in normal medium; it can be restored to the higher level by the addition of HDL, LDL or both to the lipoprotein-deficient medium. In view of these results, we propose that HDL and LDL regulate T. cruzi infection in mammalian hosts by inhibiting the parasite neuraminidase activity.     

The development of mouse APECED models provides new insight into the role of AIRE in immune regulation

Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy is a rare recessive autoimmune disorder caused by a defect in a single gene called AIRE (autoimmune regulator). Characteristics of this disease include a variable combination of autoimmune endocrine tissue destruction, mucocutaneous candidiasis and ectodermal dystrophies. The development of Aire-knockout mice has provided an invaluable model for the study of this disease. The aim of this review is to briefly highlight the strides made in APECED research using these transgenic murine models, with a focus on known roles of Aire in autoimmunity. The findings thus far are compelling and prompt additional areas of study which are discussed.     

Role of macrophages,interferon gamma and procoagulant activity in the resistance of genetic heterogeneous mouse populations to mouse hepatitis virus infection

Summary Genetic heterogeneous mouse populations selected for high (H_III) and low (L_III) antibody response were used to study some aspects of mouse hepatitis virus 3 (MHV3) infection, such as the resistance pattern, virus replication in the liver and peritoneal exudate or in cultured peritoneal macrophages, the interferon (IFN) synthesis in the serum and peritoneal exudate and the procoagulant activity (PCA) of the peritoneal exudate (PEC) and spleen cells (SC). The H_III mice, when compared to their L_III mice counterparts, were susceptible to MHV3 infection showing higher virus titres in the liver and peritoneal exudate, comparable IFN alpha/beta or IFN gamma titres in the peritoneal exudate or in the serum, and higher levels of PCA of PEC and SC. A higher virus titre was detected in the supernatants of H_III mouse macrophages infected with MHV3. The activation of H_III mouse macrophages with LPS, IFN alpha/beta or IFN gamma, in contrast to that of L_III mouse macrophages, did not induce an antiviral effect with partial restriction of the MHV3 replication. The LPS antiviral activity was shown to be partially exerted by IFN alpha/beta synthesis. The IFN gamma was shown to be more effective in inducing an antiviral state in L_III macrophages, when compared to IFN alpha/beta. The data obtained are consistent with the notion that the resistance mechanisms to the MHV3 infection involve the PCA and the sensitivity of macrophages to IFN.     

A novel avian virus with trisegmented double-stranded RNA and further observations on previously described similar viruses with bisegmented genome

The occurrence in chickens of small viruses with bisegmented double-stranded RNA (dsRNA) genome is confirmed and a new virus with similar properties but with three genome segments is described. Both differ from birnaviruses (Intervirology 25, 141-143, 1986) in having indistinct surface structure, smaller diameters (35 nm), and higher buoyant density (1.4 g/ml) in CsCl but are similar in these respects to viruses previously described in several mammals (Lancet 2, 103-104, 1988; J. Gen. Virol. 69, 2749-2754, 1988; Res. Vet. Sci, in press) under the tentative name of picobirnaviruses (PBV). Genome segment length estimations gave values of 2.6 and 1.9 kbp for the avian PBV and 2.9, 2.4 and 0.9 kbp for the trisegmented viruses. The source and pathogenic potential of these viruses remain to be established.     

Epidemiology,characterization, and diagnosis of neuropsychiatric events in systemic lupus erythematosus

Introduction: Neuropsychiatric systemic lupus erythematosus (NPSLE) is characterized by a heterogeneity of clinical manifestations. The absence of diagnostic criteria and the lack of clinical trials is a challenge in clinical practice.

Areas covered: A literature review was performed to describe epidemiology, characterization (clinical, immunological, and imaging), diagnosis and treatment of NPSLE. Classification criteria have been the first step towards a uniform definition. More recently, different attribution models have been developed to help to determine if the NP event is due to SLE. Disease activity is a major risk factor for NP events. Cytokines and autoantibodies are associated with NP events, however, only a few studies have identified risk factors for individual NP events.

Expert opinion: Further research needs to search for and validate biomarkers for NPSLE and individual NP events, including neuroimaging findings, attribution models, and serologic markers. This will be a fundamental step in planning randomized control trials in the treatment of NPSLE to improve outcome.     

Course-related depressive syndromes in schizophrenia

The authors evaluated 20 patients, diagnosed by Research Diagnostic Criteria after 1 week of hospitalization as having schizophrenia, weekly throughout their hospitalization. Four patients developed syndromes of depression after resolution of their psychoses: three manifesting a "minor" and one a "major" postpsychotic depressive syndrome. Four other patients went on to develop syndromes equivalent to major depression at a time when they were still actively psychotic, and their cross-sectional diagnoses were therefore changed to schizoaffective disorder, depressed type. The authors discuss the implications of these findings for diagnosis.     

Clearing the clouds: Case‐report and review of the literature

In peritoneal dialysis (PD), a cloudy dialysate is an alarming finding. Bacterial peritonitis is the most common cause, however, atypical infections and non‐infectious causes must be considered. A 46‐year‐old man presented with asthenia, paraesthesia, foamy urine and hypertension. Laboratory testing revealed severe azotaemia, anaemia, hyperkalaemia and nephrotic‐range proteinuria. Haemodialysis was started through a central venous catheter. Later, due to patient preference, a Tenckhoff catheter was inserted. Conversion to PD occurred 3 weeks later, during hospitalization for a presumed central line infection. A month later, the patient was hospitalized for neutropenic fever. He was diagnosed an acute parvovirus infection and was discharged under isoniazid for latent tuberculosis. Four months later, the patient presented with fever and a cloudy effluent. Peritoneal fluid (PF) cytology was suggestive of infectious peritonitis, but the symptoms persisted despite antibiotic therapy. Bacterial and mycological cultures were negative. No neoplastic cells were detected. Mycobacterium tuberculosis eventually grew in PF cultures, despite previous negative molecular tests. Directed therapy was then initiated with excellent response. Thus, facing a cloudy effluent, one must consider multiple aetiologies. Diagnosis of peritoneal tuberculosis is hampered by the lack of highly sensitive and specific exams. Here, diagnosis was only possible due to positive mycobacterial cultures.     

Pseudoangiosarcomatous squamous cell carcinoma: first case report on penis

Pseudoangiosarcomatous squamous cell carcinoma, also called pseudovascular, pseudoangiomatoid or adenoid pseudovascular carcinoma, is an uncommon and highly aggressive variant of squamous cell carcinoma. Histologically, it is characterized by proliferation of atypical keratinocytes with acantholysis and formation of pseudovascular spaces, forming anastomosed channels lined with neoplastic cells that invade the dermis. These cells are positive for cytokeratin and negative for vascular markers such as CD31 and CD34. There are few reports of this variant in the literature. Skin, breast, lung and vulva involvement have been described, but to the best of our knowledge, no cases involving the penis has been described. This study aims to describe the first case of angiosarcomatous squamous cell carcinoma of the penis. The patient presented with a painful lesion in the penis associated with urinary retention. Macroscopic findings exhibited an ulcerative vegetating lesion that involving the entire glans and part of the penile body, as well as infiltration of penile structures and scrotal skin. Microscopy shows atypical proliferation of sarcomatous keratinocyte pattern mimicking vascular spaces. Human papilloma virus (HPV) biomarkers and polymerase chain reaction (PCR) were all negative. Advanced penile squamous cell carcinoma with aggressive lymph node metastasis. This report presents the first case of penile pseudoangiosarcomatous squamous cell carcinoma, as an important differential diagnosis.