Eletrocuaterizaçäo endoscópica do teto nasal na epistaxe severa etmoidal / Endoscopic electrocauterization of nasal roof in severe ethmoidal epistaxis

A localizaçäo de pontos inacessíveis nas fossas nasais para o controle da epistaxe severa posterior tornou-se possível através da exploraçäo endoscópica. O objetivo deste trabalho é demonstrar a técnica de eletrocauterizaçäo bipolar do teto nasal por via endoscópica, relacionando as possíveis vantagens desta modalidade terapêutica para as epistaxes de origem etmoidal. Seis pacientes com epistaxe severa posterior de origem etmoidal foram submetidos à eletrocauterizaçäo bipolar do sítio sangrante no teto nasal, através de endoscopia com telescópio 30º e aspirador-cauterizador bipolar com isolamento. A epistaxe foi resolvida em todos os casos, sem complicaçöes e o paciente teve alta hospitalar no mesmo dia sem tamponamento nasal. Esta técnica é de fácil realizaçäo, eficiente e apresenta menor morbidade.

Estudo Comparativo das abordagens transmaxilar e retromolar à artéria maxilar, na epistaxe severa posterior / Comparative study of transmaxillar and retromolar approach on posterior severe epistaxis

Esse estudo apresenta em um caso de epistaxe severa posterior tratado por duas abordagens cirúrgicas, pelas vias bucais retromolar e transmaxilar, que em ambas as técnicas a artéria maxilar é alcançada na mesma regiäo anatômica, ou seja, na regiäo zigomática, junto à tuberosidade da maxila, o que foi corroborado por estudo complementar em dez peças anatômicas.

Estudo da hipertrofia adenoideana: endoscopia x radiografia de nasofaringe / Study of enlarged adenoids: endoscopy versus radiography of the nasopharynx

Introduçäo: A avaliaçäo diagnóstica da hipertrofia adenoideana é discutida pelos autores através de comparaçäo entre a radiografia simples em perfil da nasofaringe e a endoscopia nasal. Material e método: O estudo foi realizado com um grupo de 100 pacientes, entre dois e 10 anos de idade, com quadro de obstruçäo nasal sem rinopatia ou sinusopatia. O exame radiológico da nasofaringe foi analisado pelo método de Cohen e Konakl; e a endoscopia nasal, interpretada por método descrito por Wormald e colaboradores² e modificado pelos autores. Resultados: Os resultados foram analisados estatisticamente e apresentaram igualdade entre os métodos, mostrando-se a endoscopia superior pela sua objetividade e simplicidade de realizaçäo

Schistosoma mansoni: genetic restriction and cytokine profile of the CD4 + T helper cell response to dominant epitope peptide of major egg antigen Sm-p40.

Granuloma formation in schistosomiasis is mediated by MHC class II-restricted CD4 + T helper lymphocytes sensitized to egg antigens. We previously reported that C3H mice, which develop large granulomas, display strong CD4 + T helper cell responses to the major egg antigen Sm-p40. Moreover, all members of a panel of egg antigen-specific T cell hybridomas responded to the Sm-p40 antigen. Given the significance of the Sm-p40 molecule in the C3H T cell repertoire against schistosomal egg antigens, the current work was undertaken to map its immunogenic epitopes, using a library of 15 synthetic overlapping 30-mer peptides. The dominant epitope recognized by polyclonal CD4 + Th cells was located in peptide 10 (amino acids 229-258); subdominant epitopes were detected in peptides 8 (amino acids 179-208) and 12 (amino acids 279-308). The anti-Sm-p40 T cell hybridomas variously responded to any one of the same three stimulatory peptides. Furthermore, studies with various mouse strains demonstrated that a strong anti-Sm-p40 response was restricted by H-2(k). Interestingly, the cells responding to peptide 10 and to the Sm-p40 antigen only secreted IL-2 and IFN-gamma, but not IL-4 and IL-10, indicating that they are entirely of the Th-1-type, a subset with demonstrated capacity to mediate egg granuloma formation. The identification of dominant epitopes within key egg antigens offers opportunities for desensitization of the CD4 + Th cells that mediate pathology in schistosomia sis.

A ligand for human CD48 on epithelial cells.

CD48 is a member of the Ig superfamily with a high degree of sequence homology to CD58 (LFA-3). In rodents, CD48 is the ligand for CD2 whereas in humans, CD58 is the ligand for CD2. Despite intensive efforts, no ligand for human CD48 has been convincingly demonstrated. We now show that a ligand for human CD48 is present on epithelial cells. The ligand was detected based on the ability of epithelial cells to bind both a decameric, soluble CD48 IgM fusion protein and monomeric CD48 immobilized on plastic dishes. mAbs raised to the ligand completely block binding of CD48 to all epithelial cells tested. We further show that the cell surface proteoglycan CD44 plays an auxiliary role in the binding of epithelial cells to CD48 and that this interaction involves the glycosaminoglycan binding site of CD44. No interaction of human CD48 with CD2 was detected. This is the first clear demonstration that human CD48 can function as an adhesion molecule and suggests a role for CD48 in lymphocyte epithelial cell interactions.

Tyrosine sulfation of varicella-zoster virus envelope glycoprotein gpl.

Sulfation is a common post-translational modification of secreted and membrane proteins, with the sulfate attached to tyrosine residues or to glycan side-chains. I have shown that varicella-zoster virus (VZV) envelope glycoproteins gpI, gpII, and gpIII can be labeled with [35S]sulfate. The predominant VZV glycoprotein, gpI, was shown to be sulfated on asparagine-linked glycans and on tyrosine. This is the first report of tyrosine sulfation of a viral envelope glycoprotein. Examination of the predicted amino acid sequences of gpI from the Dumas and CP-5262 VZV strains revealed the presence of a single consensus sequence for tyrosine sulfation of tyr88:IWPRNDYDGFLEN. Consensus sequences are also present in the homologues of gpI in herpes simplex type 1, herpes simplex type 2, and pseudorabies virus, suggesting that tyrosine sulfation may be a general post-translational modification of the neurotropic alphaherpesviruses.

Phosphorylation of neurotropic alphaherpesvirus envelope glycoproteins: herpes simplex virus type 2 gE2 and pseudorabies virus gI.

I have examined the state of phosphorylation of the envelope glycoproteins of two neurotropic herpesviruses, HSV-2 and PRV. HSV-2 gE2 and PRV gI, which are the homologues to HSV-1 gE, were found to be phosphorylated and phosphoaminoacid analysis revealed that both contained phosphoserine. These findings are consistent with a conserved phosphorylation of the glycoprotein homologues to HSV gE among the neurotropic alphaherpesviruses.

Abordagem da artéria maxilar na regiäo zigomática para tratamento da epistaxe posterior grave / Approach to the maxillary artery in the zigomatic area for the purpose of treatment of severe posterior epistaxis

A epistaxe posterior grave foi tratada em 15 pacientes pela técnica de abordagem a artéria maxilar pela via bucal, com descolamento subperiostal ao nível da tuberosidade da maxila, com sucesso terapeutico no controle da hemorragia, na totalidade ods casos; mostrou ser técnica rápida, de simples execuçäo e baixa morbidade; por suas características pode ser considerada uma cirurgía ambulatorial

Attachment of Giardia lamblia to rat intestinal epithelial cells.

The human enteric protozoan, Giardia lamblia, has surface membrane lectin activity which mediates parasite adherence to erythrocytes. To determine whether an intestinal binding site exists for this lectin we have studied the interaction in vitro between axenically cultured Giardia trophozoites and isolated rat intestinal epithelial cells. Scanning electron microscopy showed that Giardia attached to the apical microvillus membrane and basolateral membrane of rat enterocytes. Any location on the parasite surface could mediate attachment without predeliction for the ventral disc. Trophozoites attached more avidly to jejunal compared with colonic epithelial cells. Attachment was inhibited at 4 degrees C, by sugars and glycoproteins containing D-mannosyl residues and by subagglutinating concentrations of anti-Giardia rabbit serum and two monoclonal antibodies, all with reactivity to parasite surface membrane determinants. Trypsinisation of trophozoites also reduced attachment but the ability to attach was rapidly restored after returning trophozoites to TYI-S culture medium for 4 h at 37 degrees C. Attachment was unaltered by the presence of the microfilament inhibitor cytochalasin B and in the absence of Ca++ and Mg++ ions. These findings support previous work that Giardia possesses a surface membrane mannose binding lectin and indicate that appropriate binding sites are present on rat intestinal epithelial cells. This lectin may play a part in mediating adherence of Giardia to mammalian intestine and could be a target for host immune defence.

Varicella-zoster virus gpI and herpes simplex virus gE: phosphorylation and Fc binding.

gpI, the predominant varicella-zoster virus (VZV) envelope glycoprotein, was shown to be phosphorylated exclusively on serine and threonine residues, and phosphorylated gpI was detected in isolated virions. In cells infected with herpes simplex virus type 1 (HSV-1), a related neurotropic alpha-herpesvirus, HSV gE, the homolog to VZV gpI, and HSV gB, the homolog to VZV gpII, were also phosphorylated. The phosphate on gB and gE was alkali labile and resistant to endo H, suggesting linkage to serine and/or threonine. Although VZV gpI and HSV gE share sequence homology and similar post-translational modifications, no Fc-binding activity similar to that associated with gE was detected for gpI or any of the VZV glycoproteins.

An 88,000-Mr Giardia lamblia surface protein which is immunogenic in humans.

Human anti-Giardia lamblia sera specifically immunoprecipitated an 88,000-Mr surface protein from radioiodinated trophozoites, establishing this protein as a potentially important immunogen in humans. A mouse monoclonal antibody (GL-1) was isolated which immunoprecipitated the same 88,000-Mr surface protein recognized by the human sera. GL-1 gave uniform fluorescent staining of the cell surface and flagella of G. lamblia trophozoites from the Portland 1 and WB strains as well as fresh clinical isolates, but not of Giardia muris, suggesting that the surface antigen is specific to G. lamblia. Other human parasites, including Entamoeba histolytica, Trichomonas vaginalis, and Trichomonas hominis, were not stained. A second mouse monoclonal antibody (GL-2) gave weaker immunofluorescent staining of living G. lamblia trophozoites but intense staining of fixed cells. None of the other parasites tested were stained, with the exception of E. histolytica, which may contain a cross-reactive antigen. No proteins were recognized in immunoprecipitation studies with iodinated trophozoites.

New common nomenclature for glycoprotein genes of varicella-zoster virus and their glycosylated products.

The accumulation of recent data concerning the reactivity of monoclonal antibodies with particular varicella-zoster virus (VZV) glycoproteins and the mapping of several of their respective genes on the VZV genome has led to a unified nomenclature for the glycoprotein genes of VZV and their mature glycosylated products. Homologs to herpes simplex virus glycoprotein genes are noted.

Biochemical analysis suggests distinct functional roles for the BLAST-1 and BLAST-2 antigens.

The biochemical processing of the BLAST-1 and BLAST-2 activation antigens has been studied. Both are glycoproteins that derive from different precursors of the same apparent m.w. on SDS-PAGE. BLAST-1 is synthesized as a 43,000 m.w. light chain in association with a second heavier chain of 55,000 m.w. The light chain acquires sialylated O-linked glycans and is stably expressed at the cell surface with a half-life of 14 hr. BLAST-2 is also synthesized as a 43,000 m.w. precursor, but it acquires only unsialylated N-linked glycans. The mature glycoprotein is only expressed briefly at the cell surface (half-life of 1 to 2 hr), and is then shed into the culture supernatant as a soluble 33,000 m.w. derivative. The different fates of these molecules, one stably expressed at the cell surface and one shed, suggest disparate roles for these two antigens in B cell activation.

Cross-reactivity between herpes simplex virus glycoprotein B and a 63,000-dalton varicella-zoster virus envelope glycoprotein.

Cross-reactive monoclonal antibodies recognizing both herpes simplex virus (HSV) glycoprotein B and a major 63,000-dalton varicella-zoster virus (VZV) envelope glycoprotein were isolated and found to neutralize VZV infection in vitro. None of the other VZV glycoproteins was recognized by any polyclonal anti-HSV serum tested. These results demonstrate that HSV glycoprotein B and the 63,000-dalton VZV glycoprotein share antigenic epitopes and raise the possibility that these two proteins have a similar function in infection.

Identification of the products of a varicella-zoster virus glycoprotein gene.

Two of the genes identified from the previously published DNA sequence of the Us component of the varicella-zoster virus (VZV) genome were predicted to encode membrane proteins with polypeptide molecular weights of 39000 (39K) and 70K. A rabbit antiserum directed against a unique peptide containing the seven amino acid residues at the carboxy terminus of the 39K gene product specifically precipitated glycoproteins with apparent molecular weights of 55K and 45K from VZV-infected cells labelled with [3H]mannose. The complete inhibition of precipitation of gp55 by free peptide and the partial inhibition of precipitation of gp45 support the conclusion that the 39K gene encodes gp55 and perhaps gp45. The number of VZV genes currently thought to encode glycoproteins is discussed in view of this finding.

Varicella-zoster virus envelope glycoproteins: biochemical characterization and identification in clinical material.

Varicella-zoster virus (VZV)-infected human foreskin fibroblasts synthesize viral glycoproteins of 125,000 (gp125), 118,000 (gp118), 92,000 (gp92), 63,000 (gp63), 59,000 (gp59), and 47,000 (gp47) Da. In biochemical studies, all of these VZV glycoproteins were shown to contain asparagine-linked (N-linked) oligosaccharide chains and, except for gp125 and gp47, to be sialoglycoproteins. Experiments with endo-beta-N-acetylglucosaminidase H (endo H) demonstrated that gp92 contained only complex type (endo H-resistant) N-linked glycosyl chains, while the other mature glycoproteins contained both high-mannose (endo H-sensitive) and complex-type oligosaccharides. Monoclonal antibodies recognizing multiple glycoproteins, gp63/gp125 or gp92/gp59/gp47, neutralized virus infection, suggesting the glycoproteins were important components of the virus envelope. This was confirmed for gp92/gp59/gp47 by immunoelectron microscopy, which revealed dense staining localized exclusively to the virion envelope and to the plasma membrane of virus-producer cells. The mature forms of all of these glycoproteins were also present in viral material isolated from vesicles of varicella and zoster patients, indicating that in infected individuals the viral glycoproteins are synthesized and processed in a manner similar to that in tissue culture cells.

A rapid procedure for the enrichment of undenaturated, antigenically active herpes simplex virus glycoproteins.

The usefulness of lentil lectin affinity chromatography for the rapid enrichment of HSV glycoproteins in an undenatured state for both research and clinical purposes was investigated. In order to compare the lentil lectin-binding characteristics and immunologic specificities of undenatured HSV-1 and HSV-2 glycoproteins, [35S]methionine-labelled extracts of virus-infected HEp-2 cells were subjected to lentil lectin affinity chromatography. Individual HSV-1 and HSV-2 glycoproteins in bound and unbound fractions were identified using monoclonal antibodies. With the exception of a portion of pgD and gD, all major viral glycoprotein species (gA, gB, gC, gD, gE and gF) and their glycosylated processive intermediates bound to lentil lectin indicating that all possess predominantly mannosyl and/or glucosyl carbohydrate moieties. Although the unbound pgD and gD species were glycosylated, no gD and only a portion of pgD bound to lentil lectin when reapplied to the column indicating that these subspecies possess alterations in factors required for efficient lectin binding. Immunoprecipitation of undenatured lectin-bound glycoproteins from infected cells using HSV-1 and HSV-2-specific rabbit and human antisera confirmed previous findings that the predominant type-specific glycoproteins of HSV-1 and HSV-2 are gC and gE/gF, respectively.

Synthesis and processing of the three major envelope glycoproteins of Epstein-Barr virus.

In pulse-chase experiments, the three major Epstein-Barr virus envelope glycoproteins, gp350/300, gp250/200, and gp85, were shown to be synthesized from separate precursors of 190,000, 160,000, and 83,000 daltons, respectively. These three pulse-labeled species were chased into the mature forms of the glycoproteins between 1 and 3 h after transfer to nonradioactive medium. Digestion of precursor forms with endo-beta-N-acetylglucosaminidase H (endo H) yielded polypeptides of 160,000, 120,000, and 75,000 daltons. Comparison of these results with those from experiments with tunicamycin, which specifically blocks N-linked glycosylation, indicated that some other post-translational modification(s), probably O-linked glycosylation, contributes about 100,000 and 60,000 daltons of apparent molecular mass to gp350/300 and gp250/200, respectively. Experiments with endo H showed that mature gp350/300 and gp250/200 contain complex-type (endo H-resistant) N-linked glycosyl chains, whereas gp85 contains both high-mannose (endo H-sensitive)- and complex-type oligosaccharides. In contrast to the results obtained with the three envelope glycoproteins, no precursor forms of the two unglycosylated protein, p160 (the major Epstein-Barr virus capsid antigen) and p140 (an envelope protein), were detected. The partial proteolytic maps of gp350/300 and gp250/200 were quite similar, suggesting that polypeptide sequence homology could account for at least part of the observed serological cross-reactivity of the two proteins. Taken together, these results demonstrate that the polypeptide portions of gp350/300 and gp250/200 are closely related but not derived from a common precursor. Furthermore, the polypeptide portions comprise half or less of the apparent molecular weight of the mature glycoproteins on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

An unusually high-titer human anti-Epstein Barr virus (EBV) serum and its use in the study of EBV-specific proteins synthesized in vitro and in vivo.

Sera from a patient with a chronic Epstein Barr virus (EBV) infection contained unusually high anti-EBV antibody titers (1:2560 to 1:10,240 for EA(D) and 1:5,120 to 1:40,960 for VCA). One of these serum samples was shown by immunoprecipitation to recognize at least 11 EBV-specific proteins from virus producer cells labeled in vivo and 10 EBV-specific proteins from in vitro translations of producer cell mRNA. Six of the in vivo labeled proteins (135,000, 89,000, 50,000 to 55,000 doublet, 46,000, and 34,000 daltons) are "early" by their resistance to phosphonoacetic acid, and five (350,000, 220,000, 160,000, 140,000, and 85,000 daltons) are "late" membrane and capsid proteins. The EBV-specific proteins immunoprecipitated from in vitro translations had molecular masses of 150,000, 140,000, 115,000, 52,000, 50,000, 45,000, 34,000, 29,000, 17,000, and 15,000. Subcellular fractionation studies of cells labeled in vivo revealed that the 135,000-dalton protein and part of the 50,000 to 55,000 dalton protein doublet were found in both the nuclear and the cytoplasmic fractions, and thus are good candidates to be components of the EA(D) diffuse-type immunofluorescence observed with many EA-positive sera.