Jungle yellow fever: clinical and laboratorial sudies emphasizing viremia on a human case

The authors report the clinical, laboratorial and epidemiological aspects of a human case of jungle yellow fever. The patient suffered from fever, chills, sweating, headaches, backaches, myalgia, epigastric pains, nausea, vomiting, diarrhea and prostration. He was unvaccinated and had been working in areas where cases of jungle yellow fever had been confirmed. Investigations concerning the yellow fever virus were performed. Blood samples were collected on several days in the course of the illness. Three of these samples (those obtained on days 5,7 and 10) were inoculated into suckling mice in attempt to isolate virus and to titrate the viremia level. Serological surveys were carried out by using the IgM Antibodies Capture Enzyme Linked Immunosorbent Assay (MAC-ELISA), Complement Fixation (CF), Hemagglulinalion Inhibition (HI) and Neutralization (N) tests. The yellow fever virus, recovered from the two first samples and the virus titration, showed high level of viremia. After that, specific antibodies appeared in all samples. The interval between the end of the viremia and the appearance of the antibodies was associated with the worsening of clinical symptoms, including bleeding of the mucous membrane. One must be aware of the risk of having a urban epidemics in areas where Aedes aegypti is found in high infestation indexes.

Training-related accidents during teacher-student-assistance activities of medical students

A survey was done to determine the most common hospital accidents with biologically contaminated material among students at the Medical College of the Federal University of Minas Gerais. Six hundred and ninety-four students (between fifth and twelfth semesters of the college course) answered the questionnaire individually. Three-hundred and forty-nine accidents were reported. The accident rate was found to be 33.9% in the third semester of the course, and increased over time, reaching 52.3% in the last semester. Sixty-three percent of the accidents were needlestick or sharp object injuries; 18.3% mucous membrane exposure; 16.6% were on the skin, and 1.7% were simultaneously on the skin and mucous membrane exposure. The contaminating substances were: blood (88.3%), vaginal secretion (1.7%), and others (9.1%). The parts of the body most frequently affected were: hands (67%), eyes (18.9%), mouth (1.7%), and others (6.3%). The procedures being performed when the accidents occurred were: suture (34.1%), applying anesthesia (16.6%), assisting surgery (8.9%), disposing of needles (8.6%), assisting delivery (6.3%), and others (25.9%). Forty-nine percent of those involved reported the accident to the accident control department. Of these 29.2% did not receive adequate medical assistance. Eight percent of those involved used antiretroviral drugs and of these 86% discontinued the treatment on receiving the Elisa method applied to the patient (HIV-negative); 6.4% discontinued the treatment due to its side-effects; and 16% completed the treatment.

Alveolar macrophages and lung dendritic cells sense RNA and drive mucosal IgA responses.

The mechanisms regulating systemic and mucosal IgA responses in the respiratory tract are incompletely understood. Using virus-like particles loaded with single-stranded RNA as a ligand for TLR7, we found that systemic vs mucosal IgA responses in mice were differently regulated. Systemic IgA responses following s.c. immunization were T cell independent and did not require TACI or TGFbeta, whereas mucosal IgA production was dependent on Th cells, TACI, and TGFbeta. Strikingly, both responses required TLR7 signaling, but systemic IgA depended upon TLR7 signaling directly to B cells whereas mucosal IgA required TLR7 signaling to lung dendritic cells and alveolar macrophages. Our data show that IgA switching is controlled differently according to the cell type receiving TLR signals. This knowledge should facilitate the development of IgA-inducing vaccines.

Dendritic cells: the host Achille's heel for mucosal pathogens?

Mucosal surfaces represent the main sites of interaction with environmental microorganisms and antigens. Sentinel cells, including epithelial cells and dendritic cells (DCs), continuously sense the environment and coordinate defenses for the protection of mucosal tissues. DCs play a central role in the control of adaptive immune responses owing to their capacity to internalize foreign materials, to migrate into lymph nodes and to present antigens to naive lymphocytes. Some pathogenic microorganisms trigger epithelial responses that result in the recruitment of DCs. These pathogens hijack the recruited DCs to enable them to infect the host, escape the host's defense mechanisms and establish niches at remote sites.

A case of oesophageal cancer limited to the mucosa and submucosa

The authors report a case of an oesophageal cancer limited to the mucosa and the submucosa. This case is interesting because of its long history for more than 18 months, the difficulty of fiberoptic diagnosis and the diagnostic value of rigid instruments completed via vital staining by o-toluidine.

Clinical, Parasitological and Immunological Aspects of Experimental Infection with Trypanosoma evansi in Dogs

This research investigated the pattern of antibody response by means of enzyme linked immunosorbent assay (Elisa) and indirect fluorescent antibody test (IFAT) through the course of experimental Trypanosoma evansi infection in dogs. Clinical and parasitological features were also studied. The average prepatent period was 11.2 days and parasitaemia showed an undulating course. Biometrical study of parasites revealed a mean total length of 21.68mm. The disease was characterized by intermittent fever closely related to the degree of parasitaemia and main clinical signs consisted of pallor of mucous membrane, edema, progressive emaciation and enlargement of palpable lymph nodes. Diagnostic antibody was detected within 12 to 15 days and 15 to 19 days of infection by IFAT and Elisa, respectively. High and persistent antibody levels were detected by both tests and appeared not to correlate with control of parasitaemia

Monitoring of vaccine-specific gamma interferon induction in genital mucosa of mice by real-time reverse transcription-PCR.

Monitoring of T-cell responses in genital mucosa has remained a major challenge because of the absence of lymphoid aggregates and the low abundance of T cells. Here we have adapted to genital tissue a sensitive real-time reverse transcription-PCR (TaqMan) method to measure induction of gamma interferon (IFN-gamma) mRNA transcription after 3 h of antigen-specific activation of CD8 T cells. For this purpose, we vaccinated C57BL/6 mice subcutaneously with human papillomavirus type 16 L1 virus-like particles and monitored the induction of CD8 T cells specific to the L1(165-173) H-2D(b)-restricted epitope. Comparison of the responses induced in peripheral blood mononuclear cells and lymph nodes (LN) by L1-specific IFN-gamma enzyme-linked immunospot assay and TaqMan determination of the relative increase in L1-specific IFN-gamma mRNA induction normalized to the content of CD8b mRNA showed a significant correlation, despite the difference in the readouts. Most of the cervicovaginal tissues could be analyzed by the TaqMan method if normalization to glyceraldehyde-3-phosphate dehydrogenase mRNA was used and a significant L1-specific IFN-gamma induction was found in one-third of the immunized mice. This local response did not correlate with the immune responses measured in the periphery, with the exception of the sacral LN, an LN draining the genital mucosa, where a significant correlation was found. Our data show that the TaqMan method is sensitive enough to detect antigen-specific CD8 T-cell responses in the genital mucosa of individual mice, and this may contribute to elaborate effective vaccines against genital pathogens.

Potential exposure to hepatitis C virus through accidental blood contact in interventional radiology.

PURPOSE: To quantify the prevalence of accidental blood exposure (ABE) among interventional radiologists and contrast that with the prevalence of patients with hepatitis C virus (HCV) undergoing interventional radiology procedures. MATERIALS AND METHODS: A multicenter epidemiologic study was conducted in radiology wards in France. The risk of ABE to radiologists was assessed based on personal interviews that determined the frequency and type of ABE and the use of standard protective barriers. Patients who underwent invasive procedures underwent prospective sampling for HCV serologic analysis. HCV viremia was measured in patients who tested positive for HCV. RESULTS: Of the 77 radiologists who participated in 11 interventional radiology wards, 44% reported at least one incident of mucous membrane blood exposure and 52% reported at least one percutaneous injury since the beginning of their occupational activity. Compliance with standard precautions was poor, especially for the use of protective clothes and safety material. Overall, 91 of 944 treated patients (9.7%) tested positive for HCV during the study period, of whom 90.1% had positive viremia results, demonstrating a high potential for contamination through blood contacts. CONCLUSIONS: The probability of HCV transmission from contact with contaminated blood after percutaneous injury ranged from 0.013 to 0.030; the high frequency of accidental blood exposure and high percentage of patients with HCV could generate a risk of exposure to HCV for radiologists who perform invasive procedures with frequent blood contact. The need to reinforce compliance with standard hygiene precautions is becoming crucial for medical and technical personnel working in these wards.

Histological and histochemical evaluation of human oral mucosa constructs developed by tissue engineering

Reconstruction of large oral mucosa defects is often challenging, since the shortage of healthy oral mucosa to replace the excised tissues is very common. In this context, tissue engineering techniques may provide a source of autologous tissues available for transplant in these patients. In this work, we developed a new model of artificial oral mucosa generated by tissue engineering using a fibrin-agarose scaffold. For that purpose, we generated primary cultures of human oral mucosa fibroblasts and keratinocytes from small biopsies of normal oral mucosa using enzymatic treatments. Then we determined the viability of the cultured cells by electron probe quantitative X-ray microanalysis, and we demonstrated that most of the cells in the primary cultures were alive and had high K/Na ratios. Once cell viability was determined, we used the cultured fibroblasts and keratinocytes to develop an artificial oral mucosa construct by using a fibrin-agarose extracellular matrix and a sequential culture technique using porous culture inserts. Histological analysis of the artificial tissues showed high similarities with normal oral mucosa controls. The epithelium of the oral substitutes had several layers, with desmosomes and apical microvilli and microplicae. Both the controls and the oral mucosa substitutes showed high suprabasal expression of cytokeratin 13 and low expression of cytokeratin 10. All these results suggest that our model of oral mucosa using fibrin-agarose scaffolds show several similarities with native human oral mucosa.

Novel functions of the polymeric Ig receptor: well beyond transport of immunoglobulins.

The polymeric Ig receptor (pIgR) ensures efficient secretion of polymeric IgA (pIgA) at mucosal surfaces. On basal to apical transport across epithelial cells, the pIgR extracellular domain is cleaved, releasing secretory component (SC) in association with pIgA. This finds its raison d'être in the recent observation that SC is directly involved in the protective function of secretory IgA. In addition, free SC exhibits scavenger properties with respect to enteric pathogens. However, although pIgR dedicates its life to mucosal protection, it also seems to permit pathogen entrance through the epithelial barrier. The multiple mechanisms that they are involved in make pIgR and SC instrumental to mucosal immunity.

Metastasis of renal cell carcinoma to the buccal mucosa 19 years after radical nephrectomy

Renal cell carcinoma (RCC) has high metastatic potential, which requires early diagnosis to optimize the chance of cure. Metastasis of RCC to the head and neck region is less common and metastasis to the buccal mucosa is extremely rare. This phenomenon occurs mostly in patients with generalized dissemination, especially with lung metastases. In this article we report a case of buccal mucosa metastasis from RCC in a 65-year-old man who presented 19 years after undergoing a left radical nephrectomy for clear cell RCC. Surgical excision of the buccal lesion was performed without evidence of recurrence or new metastatic lesions after 6 years of followup. To our knowledge, this is the first case of metastasis to the buccal mucosa from a RCC reported in the literature.

Parenteral is more efficient than mucosal immunization to induce regression of human papillomavirus-associated genital tumors.

Cervical cancer is a public health concern as it represents the second cause of cancer death in women worldwide. High-risk human papillomaviruses (HPV) are the etiologic agents, and HPV E6 and/or E7 oncogene-specific therapeutic vaccines are under development to treat HPV-related lesions in women. Whether the use of mucosal routes of immunization may be preferable for inducing cell-mediated immune responses able to eradicate genital tumors is still debated because of the uniqueness of the female genital mucosa (GM) and the limited experimentation. Here, we compared the protective activity resulting from immunization of mice via intranasal (i.n.), intravaginal (IVAG) or subcutaneous (s.c.) routes with an adjuvanted HPV type 16 E7 polypeptide vaccine. Our data show that s.c. and i.n. immunizations elicited similar frequencies and avidity of TetE71CD81 and E7-specific Interferon-gamma-secreting cells in the GM, whereas slightly lower immune responses were induced by IVAG immunization. In a novel orthotopic murine model, both s.c. and i.n. immunizations allowed for complete long-term protection against genital E7-expressing tumor challenge. However, only s.c. immunization induced complete regression of already established genital tumors. This suggests that the higher E7-specific systemic response observed after s.c. immunization may contribute to the regression of growing genital tumors, whereas local immune responses may be sufficient to impede genital challenges. Thus, our data show that for an efficiently adjuvanted protein-based vaccine, parenteral vaccination route is superior to mucosal vaccination route for inducing regression of established genital tumors in a murine model of HPV-associated genital cancer.

The role of polymerase chain reaction of high-risk human papilloma virus in the screening of high-grade squamous intraepithelial lesions in the anal mucosa of human immunodeficiency virus-positive males having sex with males.

OBJECTIVES To evaluate the advantages of cytology and PCR of high-risk human papilloma virus (PCR HR-HPV) infection in biopsy-derived diagnosis of high-grade squamous intraepithelial lesions (HSIL = AIN2/AIN3) in HIV-positive men having sex with men (MSM). METHODS This is a single-centered study conducted between May 2010 and May 2014 in patients (n = 201, mean age 37 years) recruited from our outpatient clinic. Samples of anal canal mucosa were taken into liquid medium for PCR HPV analysis and for cytology. Anoscopy was performed for histology evaluation. RESULTS Anoscopy showed 33.8% were normal, 47.8% low-grade squamous intraepithelial lesions (LSIL), and 18.4% HSIL; 80.2% had HR-HPV. PCR of HR-HPV had greater sensitivity than did cytology (88.8% vs. 75.7%) in HSIL screening, with similar positive (PPV) and negative predictive value (NPV) of 20.3 vs. 22.9 and 89.7 vs. 88.1, respectively. Combining both tests increased the sensitivity and NPV of HSIL diagnosis to 100%. Correlation of cytology vs. histology was, generally, very low and PCR of HR-HPV vs. histology was non-existent (<0.2) or low (<0.4). Area under the receiver operating characteristics (AUROC) curve analysis of cytology and PCR HR-HPV for the diagnosis of HSIL was poor (<0.6). Multivariate regression analysis showed protective factors against HSIL were: viral suppression (OR: 0.312; 95%CI: 0.099-0.984), and/or syphilis infection (OR: 0.193; 95%CI: 0.045-0.827). HSIL risk was associated with HPV-68 genotype (OR: 20.1; 95%CI: 2.04-197.82). CONCLUSIONS When cytology and PCR HR-HPV findings are normal, the diagnosis of pre-malignant HSIL can be reliably ruled-out in HIV-positive patients. HPV suppression with treatment protects against the appearance of HSIL.

Kartagener syndrome: an uncommon cause of neonatal respiratory distress?

We report a newborn with respiratory distress and situs inversus totalis. The diagnosis of primary ciliary dyskinesia was confirmed by both ultrastructural and functional investigations. The immotile cilia syndrome was suspected because of respiratory distress, situs inversus, abnormal nasal discharge and hyperinflated chest X-ray. We suggest that ultrastructural and functional investigations of the respiratory mucosa should be done in any newborn with respiratory distress without explanation for the respiratory problems. Establishment of the correct diagnosis at an early stage may allow to improve the prognosis provided prophylactic physiotherapy, vaccinations, and aggressive antibiotic treatment of intercurrent respiratory infections are instituted. CONCLUSION Despite its rarity, primary ciliary dyskinesia should be considered in unexplained cases of neonatal distress.

Isolation and characterization of carcinoembryonic antigen (CEA) extracted from normal human colon mucosa.

Carcinoembryonic antigen (CEA) was identified in perchloric acid (PCA)_extract from normal colon mucosa by 2 immunological criteria: a line of identity in double diffusion and a parallel inhibition curve in radioimmunoassay (RIA), both with reference colon carcinoma-CEA (CEA-Tu). The average concentration of CEA in normal colon mucosa (CEA-No) was 35 times lower than in primary large bowel carcinomas and 230 times lower than in metastatic colon or rectum carcinomas. CEA-No was purified from PCA extracts of normal colon mucosa by Sephadex G-200 filtration and immunoadsorbent columns. Purified CEA-No had quatitatively the same inhibition activity in RIA as the British Standard CEA coded 73/601. Purified CEA-No was labelled with 125I. The percentage of binding of labelled CEA-No to a specific goat anti-CEA-Tu antiserum was similar to that of CEA-Tu. Labelled CEA-No could be used as radioactive tracer in RIA as well as labelled CEA-Tu. The physico-chemical properties of purified CEA-Tu as demonstrated by Sepharose 6 B filtration, SDS Polyacrylamide gel analysis and cesium chloride density gradient, were found to be almost identical to those of reference CEA-Tu. Preliminary results showed that CEA-No and CEA-Tu contained the same types of carbohydrates in similar proportions. A rabbit antiserum against CEA-No was obtained which demonstrated the same specificity as conventional anti-CEA-Tu antisera.