High Nuclease Activity of Long Persisting Staphylococcus aureus Isolates Within the Airways of Cystic Fibrosis Patients Protects Against NET-Mediated Killing.

Staphylococcus aureus is one of the first and most prevalent pathogens cultured from the airways of cystic fibrosis (CF) patients, which can persist there for extended periods. Airway infections in CF patients are characterized by a strong inflammatory response of highly recruited neutrophils. One killing mechanism of neutrophils is the formation of neutrophil extracellular traps (NETs), which capture and eradicate bacteria by extracellular fibers of neutrophil chromatin decorated with antimicrobial granule proteins. S. aureus secretes nuclease, which can degrade NETs. We hypothesized, that S. aureus adapts to the airways of CF patients during persistent infection by escaping from NET-mediated killing via an increase of nuclease activity. Sputum samples of CF patients with chronic S. aureus infection were visualized by confocal microscopy after immuno-fluorescence staining for NET-specific markers, S. aureus bacteria and overall DNA structures. Nuclease activity was analyzed in sequential isogenic long persisting S. aureus isolates, as confirmed by whole genome sequencing, from an individual CF patient using a FRET-based nuclease activity assay. Additionally, some of these isolates were selected and analyzed by qRT-PCR to determine the expression of nuc1 and regulators of interest. NET-killing assays were performed with clinical S. aureus isolates to evaluate killing and bacterial survival depending on nuclease activity. To confirm the role of nuclease during NET-mediated killing, a clinical isolate with low nuclease activity was transformed with a nuclease expression vector (pCM28nuc). Furthermore, two sputa from an individual CF patient were subjected to RNA-sequence analysis to evaluate the activity of nuclease in vivo. In sputa, S. aureus was associated to extracellular DNA structures. Nuclease activity in clinical S. aureus isolates increased in a time-and phenotype-dependent manner. In the clinical isolates, the expression of nuc1 was inversely correlated to the activity of agr and was independent of saeS. NET-mediated killing was significantly higher in S. aureus isolates with low compared to isolates with high nuclease activity. Importantly, transformation of the clinical isolate with low nuclease activity with pCM28nuc conferred protection against NET-mediated killing confirming the beneficial role of nuclease for protection against NETs. Also, nuclease expression in in vivo sputa was high, which underlines the important role of nuclease within the highly inflamed CF airways. In conclusion, our data show that S. aureus adapts to the neutrophil-rich environment of CF airways with increasing nuclease expression most likely to avoid NET-killing during long-term persistence.

Cloning, expression and purification of 3'-nucleotidase/nuclease, an enzyme responsible for the Leishmania escape from neutrophil extracellular traps.

Leishmaniasis is one of the most significant of the neglected tropical diseases, with 350 million people in 98 countries worldwide living at risk of developing one of the many forms of the disease. During the transmission of the parasite from its vector to the vertebrate host, neutrophils are rapidly recruited to the site of the sandfly bite. Using different strategies, neutrophils can often kill a large number of parasites. However, some parasites can resist neutrophil-killing mechanisms and survive until macrophage arrival at the infection site. One of the strategies for neutrophil-mediated killing is the production of neutrophil extracellular traps (NETs). Because of its ecto-localized nuclease activity, the enzyme 3'-nucleotidase/nuclease (3'NT/NU), present in different Leishmania species, was recently identified as part of a possible parasite escape mechanism from NET-mediated death. Previous studies showed that 3'NT/NU also plays an important role in the establishment of Leishmania infection by generating extracellular adenosine that favors the parasite and macrophage interaction. This study aims to deepen the knowledge about 3'NT/NU, mainly with respect to its nuclease activity that is little studied in the current literature. For this, we cloned, expressed and purified the recombinant La3'NT/NU and have confirmed its contribution to the parasite escape from NET-mediated killing.

Molecular characterization of shrimp harbinger transposase derived 1 (HARBI1)-like and its role in white spot syndrome virus and Vibrio alginolyticus infection.

The role of the nuclease, HARBI1-like protein (mjHARBI1-like) in the innate immunity of Marsupenaeus japonicus was explored in this study. The 1361 bp cDNA sequence of mjHARBI1-like was cloned from M. japonicus using RACE. RT-qPCR analysis results showed that the gills and hepatopancreas of M. japonicus were the main tissues where mjHARBI1-like is expressed. In addition, it was also found that white spot syndrome virus (WSSV) or Vibrio alginolyticus challenge could stimulate mjHARBI1-like expression. After mjHARBI1-likewas inhibited, expression of immune genes such as toll, p53, myosin, and proPO were significantly downregulated (P < 0.01). However, in shrimp hemocytes, hemocyanin and tumor necrosis factor-α (TNF-α) were up-regulated significantly (P < 0.01). This study demonstrated that mjHARBI1-like plays a key role in the progression of WSSV and V. alginolyticus infection. Specifically, the cumulative mortality of WSSV-infected and V. alginolyticus-infected shrimp was significantly advanced by double-strand RNA interference (dsRNAi) of mjHARBI1-like. Apoptosis studies indicated that mjHARBI1-dsRNA treatment caused a reduction in hemocyte apoptosis in bacterial and viral groups. In addition, phagocytosis experiments illustrated that mjHARBI1-dsRNA treatment led to a lower phagocytosis rate in hemocytes of V. alginolyticus-challenged shrimp. It was also found that knockdown of mjHARBI1-like inhibited shrimp phenoloxidase (PO) activity, superoxide dismutase (SOD) activity, and total hemocyte count (THC) after WSSV or V. alginolyticus infection. These data indicate a regulative role of mjHARBI1-likein the immunity of shrimp in response to pathogen infection. Resultantly, it was concluded that mjHARBI1-like might have a positive effect on the anti-WSSV immune response of shrimp by regulating apoptosis, THC, PO activity, and SOD activity. Additionally, mjHARBI1-like might promote anti-V. alginolyticus infection by participating in regulating phagocytosis, apoptosis, SOD activity, PO activity, and THC.

Deletion of ssnA Attenuates the Pathogenicity of Streptococcus suis and Confers Protection against Serovar 2 Strain Challenge.

Streptococcus suis serotype 2 (SS2) is a major porcine and human pathogen which causes arthritis, meningitis, and septicemia. Streptococcus suis nuclease A (SsnA) is a recently discovered deoxyribonuclease (DNase), which has been demonstrated to contribute to escape killing in neutrophil extracellular traps (NETs). To further determine the effects of ssnA on virulence, the ssnA deletion mutant (ΔssnA) and its complemented strain (C-ΔssnA) were constructed. The ability of ΔssnA mutant to interact with human laryngeal epithelial cell (Hep-2) was evaluated and it exhibited dramatically decreased ability to adhere to and invade Hep-2 cells. This mutation was found to exhibit significant attenuation of virulence when evaluated in CD1 mice, suggesting ssnA plays a critical role in the pathogenesis of SS2. Finally, we found that immunization with the ΔssnA mutant triggered both antibody responses and cell-mediated immunity, and conferred 80% protection against virulent SS2 challenge in mice. Taken together, our results suggest that ΔssnA represents an attractive candidate for designing an attenuated live vaccine against SS2.

Silencing the shutoff protein of Epstein-Barr virus in productively infected B cells points to (innate) targets for immune evasion.

During productive infection with Epstein-Barr virus (EBV), a dramatic suppression of cellular protein expression is caused by the viral alkaline exonuclease BGLF5. Among the proteins downregulated by BGLF5 are multiple immune components. Here, we show that shutoff reduces expression of the innate EBV-sensing Toll-like receptor-2 and the lipid antigen-presenting CD1d molecule, thereby identifying these proteins as novel targets of BGLF5. To silence BGLF5 expression in B cells undergoing productive EBV infection, we employed an shRNA approach. Viral replication still occurred in these cells, albeit with reduced late gene expression. Surface levels of a group of proteins, including immunologically relevant molecules such as CD1d and HLA class I and class II, were only partly rescued by depletion of BGLF5, suggesting that additional viral gene products interfere with their expression. Our combined approach thus provides a means to unmask novel EBV (innate) immune evasion strategies that may operate in productively infected B cells.

Cooperation between Epstein-Barr virus immune evasion proteins spreads protection from CD8+ T cell recognition across all three phases of the lytic cycle.

CD8+ T cell responses to Epstein-Barr virus (EBV) lytic cycle expressed antigens display a hierarchy of immunodominance, in which responses to epitopes of immediate-early (IE) and some early (E) antigens are more frequently observed than responses to epitopes of late (L) expressed antigens. It has been proposed that this hierarchy, which correlates with the phase-specific efficiency of antigen presentation, may be due to the influence of viral immune-evasion genes. At least three EBV-encoded genes, BNLF2a, BGLF5 and BILF1, have the potential to inhibit processing and presentation of CD8+ T cell epitopes. Here we examined the relative contribution of these genes to modulation of CD8+ T cell recognition of EBV lytic antigens expressed at different phases of the replication cycle in EBV-transformed B-cells (LCLs) which spontaneously reactivate lytic cycle. Selective shRNA-mediated knockdown of BNLF2a expression led to more efficient recognition of immediate-early (IE)- and early (E)-derived epitopes by CD8+ T cells, while knock down of BILF1 increased recognition of epitopes from E and late (L)-expressed antigens. Contrary to what might have been predicted from previous ectopic expression studies in EBV-negative model cell lines, the shRNA-mediated inhibition of BGLF5 expression in LCLs showed only modest, if any, increase in recognition of epitopes expressed in any phase of lytic cycle. These data indicate that whilst BNLF2a interferes with antigen presentation with diminishing efficiency as lytic cycle progresses (IE>E>>L), interference by BILF1 increases with progression through lytic cycle (IE

A nucleic-acid hydrolyzing single chain antibody confers resistance to DNA virus infection in hela cells and C57BL/6 mice.

Viral protein neutralizing antibodies have been developed but they are limited only to the targeted virus and are often susceptible to antigenic drift. Here, we present an alternative strategy for creating virus-resistant cells and animals by ectopic expression of a nucleic acid hydrolyzing catalytic 3D8 single chain variable fragment (scFv), which has both DNase and RNase activities. HeLa cells (SCH07072) [corrected] expressing 3D8 scFv acquired significant resistance to DNA viruses. Virus challenging with Herpes simplex virus (HSV) in 3D8 scFv transgenic cells and fluorescence resonance energy transfer (FRET) assay based on direct DNA cleavage analysis revealed that the induced resistance in HeLa cells was acquired by the nucleic acid hydrolyzing catalytic activity of 3D8 scFv. In addition, pseudorabies virus (PRV) infection in WT C57BL/6 mice was lethal, whereas transgenic mice (STG90) that expressed high levels of 3D8 scFv mRNA in liver, muscle, and brain showed a 56% survival rate 5 days after PRV intramuscular infection. The antiviral effects against DNA viruses conferred by 3D8 scFv expression in HeLa cells as well as an in vivo mouse system can be attributed to the nuclease activity that inhibits viral genome DNA replication in the nucleus and/or viral mRNA translation in the cytoplasm. Our results demonstrate that the nucleic-acid hydrolyzing activity of 3D8 scFv confers viral resistance to DNA viruses in vitro in HeLa cells and in an in vivo mouse system.

Systemic lupus erythematosus: molecular cloning and analysis of recombinant DNase monoclonal κ light chain NGK-1.

Because DNase antibodies are cytotoxic, enter the nucleus and cause DNA fragmentation inducing cell death by apoptosis, they can play an important role in the pathogenesis of different autoimmune pathologies and especially systemic lupus erythematosus (SLE). The interesting goal of catalytic antibodies research is not only to study a possible biological role of such antibodies, but also to develop in future new human and animal therapies that use the advantages offered by abzymes. An immunoglobulin κ light chain library from SLE patients was cloned into a phagemid vector. Phage particles displaying recombinant monoclonal antibody light chains (MLChs) capable of binding DNA were isolated by affinity chromatography on DNA-cellulose. Sixteen of the 46 MLChs efficiently hydrolyzed DNA; one MLCh (approximately 27-28kDa) was expressed in Escherichia coli and purified by metal chelating and gel filtration. MLCh NGK-1 was electrophoretically homogeneous and demonstrated a positive answer with mouse IgGs against light chains of human antibodies after western blotting. SDS-PAGE in a gel containing DNA demonstrated that the MLCh hydrolyzes DNA and is not contaminated by canonical DNases. The DNase MLCh was activated by several metal ions. The protein sequence of the DNase MLCh has homology with mammalian DNases I and shares with them several identical or similar (with the same side chain functionality) important amino acid residues, which are necessary for DNA hydrolysis and binding of Mg(2+) and Ca(2+) ions. The affinity of DNA for this first example of a MLCh (K(M) = 0.3 microM) was 150- to 200-fold higher than for human DNase I.

TAK1-JNK axis mediates survival signal through Mcl1 stabilization in activated T cells.

TAK1, a member of MAPK kinase kinase (MAPKK-K) family, can activate JNK, p38 MAPK, and NF-κB signaling pathways. Although targeted gene disruption studies have demonstrated that TAK1 plays a critical role in T cell functions, precise functions of downstream mediators remain elusive. We used the chemical compound LL-Z1640-2, which preferentially suppressed MAPK activation but not NF-κB signal downstream of TAK1. LL-Z1640-2 blocked TCR-induced T cell proliferation and activation, confirming that a TAK1-mediated MAPK signal is essential for T cell activation. LL-Z1640-2 induced apoptosis of activated mouse splenic T cells in a caspase- and caspase-activated DNase-dependent manner. TAK1-JNK pathway, which is activated downstream of IL-2R, induced the phosphorylation of antiapoptotic protein Mcl1 in activated T cells, resulting in the stabilization of Mcl1 protein. Our data uncover that among signal transduction pathways downstream of TAK1, JNK mediates a survival program through Mcl1 stabilization downstream of IL-2R in activated T cells and that blockade of TAK1-JNK pathway can eliminate activated T cells by apoptosis.

Prognostic utility of anti-EBV antibody testing for defining NPC risk among individuals from high-risk NPC families.

PURPOSE: Epstein-Barr virus (EBV) infection and a family history of nasopharyngeal carcinoma (NPC) are associated with NPC risk. We examined the risk associated with EBV markers and their clinical utility to identify NPC susceptibles within high-risk NPC families. EXPERIMENTAL DESIGN: We evaluated antibody titers against viral capsid antigen (VCA) IgA, EBV nuclear antigen-1 (EBNA1) IgA, and DNase among unaffected relatives of NPC cases from 358 multiplex families in Taiwan. Incident NPC cases were identified via linkage to the National Cancer Registry. Clinical examinations of 924 individuals were also done to identify occult, asymptomatic NPC. Baseline EBV serology was used to estimate NPC risk using rate ratios with 95% CI. Associated sensitivity/specificity and receiver operating characteristic (ROC) curves were calculated. RESULTS: A total of 2,444 unaffected individuals with 15,519 person-years (6.5 years median follow-up) yielded 14 incident NPC cases (nearly 11 times the general population rate). The absolute rate of NPC among anti-EBV EBNA1 IgA seropositives using a standard positivity cutoff versus an optimized cutoff point defined by ROC analyses was 265/100,000 person-years with a 4.7-fold increased risk of NPC (95% CI: 1.4-16) and 166/100,000 person-years with a 6.6-fold increase (95% CI: 1.5-61), respectively. Sensitivity and specificity using the optimized positivity cutoff points were 85.7% and 51.2%, respectively. It is estimated that active evaluation of 49% of individuals from high-risk NPC families seropositive for this marker could lead to earlier detection of up to 86% of NPC cases. Risks associated with the other three EBV markers were weaker. CONCLUSIONS: Future efforts are needed to identify susceptibility markers among high-risk NPC families that maximize both sensitivity and specificity.

Serologic antienzyme rate of Epstein-Barr virus DNase-specific neutralizing antibody segregates TNM classification in nasopharyngeal carcinoma.

PURPOSE: We investigate the value of pretreatment serologic antienzyme rate (AER) of Epstein-Barr virus (EBV) DNase-specific neutralizing antibody complementing TNM staging in prognostication of nasopharyngeal carcinoma (NPC). PATIENTS AND METHODS: Pretreatment serum samples from 1,303 patients with untreated NPC were collected and examined for AER. After a 10-year follow-up period, the prognoses of the patients, classified by their clinical stage with AER, were assessed by multivariate analysis. Of the 1,303 patients, 600 patients were randomly assigned to a training set to generate an AER cutoff point by receiver operating characteristic (ROC) curve analysis. AER levels were then analyzed with overall survival (OS), progression-free survival (PFS), local failure-free survival (LFFS), and distant metastasis-free survival (DMFS) in a testing set (703 patients). Another independent cohort of 464 patients was studied in a validating set. RESULTS: In the training set, the ROC analysis-generated AER cutoff point for OS was 58.0%, which was used as the cutoff point in the testing set. The subset of low AER levels predicted a significant survival advantage over the subset of high AER levels for OS, PFS, LFFS, and DMFS in the testing set. Moreover, two distinguished subgroups were segregated by an AER level of 58.0% within each clinical stage comparing prognostication of OS, PFS, LFFS, and DMFS. Importantly, AER level was revealed as the only significant independent prognostic factor for death, recurrence, and distant metastasis in the validating set. CONCLUSION: Pretreatment serologic AER of EBV DNase-specific neutralizing antibody serves as an independent prognostic marker complementing TNM stage in NPC. Supplementing pretreatment AER with TNM staging leads to more accurate risk definition in patient subgroups.

Epstein-Barr virus evasion of CD8(+) and CD4(+) T cell immunity via concerted actions of multiple gene products.

Upon primary infection, EBV establishes a latent infection in B cells, characterized by maintenance of the viral genome in the absence of viral replication. The Epstein-Barr Nuclear Antigen 1 (EBNA1) plays a crucial role in maintenance of the viral DNA episome and is consistently expressed in all EBV-associated malignancies. Compared to other EBV latent gene products, EBNA1 is poorly recognized by CD8(+) T lymphocytes. Recent studies are discussed that shed new light on the mechanisms that underlie this unusual lack of CD8(+) T cell activation. Whereas the latent phase is characterized by the expression of a limited subset of viral gene products, the full repertoire of over 80 EBV lytic gene products is expressed during the replicative phase. Despite this abundance of potential T cell antigens, which indeed give rise to a strong response of CD4(+) and CD8(+) T lymphocytes, the virus can replicate successfully. Evidence is accumulating that this paradoxical situation is the result of actions of multiple viral gene products, inhibiting discrete stages of the MHC class I and class II antigen presentation pathways. Immediately after initiation of the lytic cycle, BNLF2a prevents peptide-loading of MHC class I molecules through inhibition of the Transporter associated with Antigen Processing, TAP. This will reduce presentation of viral antigens by the large ER-resident pool of MHC class I molecules. Synthesis of new MHC class I molecules is blocked by BGLF5. Viral-IL10 causes a reduction in mRNA levels of TAP1 and bli/LMP2, a subunit of the immunoproteasome. MHC class I molecules present at the cell surface are downregulated by BILF1. Also the antigen presenting capacity of MHC class II molecules is severely compromised by multiple EBV lytic gene products, including gp42/gH/gL, BGLF5, and vIL-10. In this review, we discuss how concerted actions of these EBV lytic proteins result in highly effective interference with CD8(+) and CD4(+) T cell surveillance, thereby providing the virus with a window for undisturbed generation of viral progeny.

Association of Epstein-Barr virus infection with systemic lupus erythematosus in Taiwan.

An association between Epstein-Barr virus (EBV) infection and systemic lupus erythematosus (SLE) has been suggested from previous serologic evidence. Since most adults in Taiwan are EBV-infected, seroepidemiologic studies based on standard assays for EBV are unlikely to dissociate SLE patients and control groups. We reexamine this question by using novel methodologies in which IgA anti-EBV-coded nuclear antigens-1 (EBNA-1) and IgG anti-EBV DNase antibodies were analysed by ELISA, and EBV viral loads were detected by real-time quantitative PCR for 93 adult SLE patients and 370 age-, sex- and living place-matched healthy controls in Taiwan. The specificities of antibodies for extractible nuclear antigens were determined by Western blot. Our results show that IgA anti-EBV EBNA1 antibodies were detectable in 31.2% SLE patients but only in 4.1% of controls (odds ratio [OR] = 10.72, 95% confidence interval [CI] = 5.19-22.35; P < 10(-7)), IgG anti-EBV DNase antibodies were detected in 53.8% SLE patients but only in 12.2% controls (OR = 8.40, 95% CI = 4.87-14.51; P < 10(-7)). EBV DNA was amplifiable from the sera of 41.9% SLE patients but from only 3.24% controls (P < 0.05). A significant association of IgG anti-EBV DNase antibodies with anti-Sm/RNP antibodies was observed (P < 0.005). The higher seroreactivity and higher copy numbers of EBV genome indicated association of EBV infection with SLE in Taiwan.

Host shutoff during productive Epstein-Barr virus infection is mediated by BGLF5 and may contribute to immune evasion.

Relatively little is known about immune evasion during the productive phase of infection by the gamma(1)-herpesvirus Epstein-Barr virus (EBV). The use of a unique system to isolate cells in lytic cycle allowed us to identify a host shutoff function operating in productively EBV-infected B cells. This impairment of protein synthesis results from mRNA degradation induced upon expression of the early lytic-cycle gene product BGLF5. Recently, a gamma(2)-herpesvirus, Kaposi sarcoma herpesvirus, has also been shown to encode a host shutoff function, indicating that host shutoff appears to be a general feature of gamma-herpesviruses. One of the consequences of host shutoff is a block in the synthesis of HLA class I and II molecules, reflected by reduced levels of these antigen-presenting complexes at the surface of cells in EBV lytic cycle. This effect could lead to escape from T cell recognition and elimination of EBV-producing cells, thereby allowing generation of viral progeny in the face of memory T cell responses.

Antibodies against four proteins from a Streptococcus pyogenes serotype M1 strain and levels of circulating mannan-binding lectin in acute poststreptococcal glomerulonephritis.

BACKGROUND: Responses against antigens from the potentially nephritogenic Streptococcus pyogenes serotype M1 in patients with acute poststreptococcal glomerulonephritis (AGN) were studied to seek indications of expression of these antigens during the preceding infection. Also, the question was asked whether the complement protein mannan-binding lectin (MBL) is required for development of the hypocomplementemia associated with AGN. Hypothetically, the lectin pathway might trigger the alternative pathway, which is consistently activated in AGN. METHODS: Antibodies against three proteins associated with M1, M1 protein, streptococcal inhibitor of complement (SIC) and protein H, an IgG-binding protein, were determined by ELISA in 56 children and 17 adults with AGN. Antibodies against streptococcal cysteine proteinase, which is produced by all serotypes of S. pyogenes, were also examined. MBL concentrations were measured in the same 71 patients by a sandwich ELISA. RESULTS: Increased concentrations of antibodies were found against all four streptococcal proteins, albeit not uniformly distributed between different subgroups of patients. The prevalence of low MBL concentrations (<100 microg/l) including 2 patients with undetectable MBL (<10 microg/l) was similar in AGN (11%) and in controls (16%). CONCLUSIONS: Our results give evidence of exposure to SIC and protein H in conjunction with AGN. This implies that SIC and protein H and/or cross-reacting proteins may have a role in the pathogenesis of AGN or that streptococci expressing SIC or protein H are nephritogenic for other reasons. The finding of MBL-deficient individuals among the patients demonstrates that MBL is not necessary for the recruitment of complement in AGN.

Immune responses to Epstein-Barr virus lytic proteins in patients with nasopharyngeal carcinoma.

Immune responses to three Epstein-Barr virus (EBV) lytic proteins, DNase, thymidine kinase (TK), and BMRF-1 gene products (50/52 kDa diffused early antigen, EA-D complex) were determined in EBV-infected control individuals and patients with nasopharyngeal carcinoma (NPC). Immunofluorescence assays (IFA) were used to detect their humoral immune responses using recombinant EBV lytic proteins expressed in a baculovirus system as antigens. Cell proliferation assays were performed to evaluate their cellular immune responses by monitoring 3H-thymidine incorporation. Seventy patients with NPC and 32 non-cancer controls were analyzed. The results of IFA showed antibody titers to all three EBV lytic proteins to be higher in the patients with NPC especially for the IgA class. Positivity rates of the three IgA antibodies also were higher in the patients with NPC population. Furthermore, the profiles of the IgA antibodies correlated with those to total early antigens (EA) expressed in the early phase and viral capsid antigen (VCA) expressed in the late phase, of EBV replication. The most interesting finding was that antibody titers to the three EBV lytic proteins were associated significantly with metastases of cervical lymph nodes in patients with NPC. As for cellular immunity to the EA-D complex and DNase, weak responses were observed in the cell proliferation assays. Peripheral blood cells from most individuals could not be stimulated to proliferate, except for a few patients with NPC whose antibody titers against the EA-D complex and DNase also were very high.

Oral contraceptive induced chorea: another condition associated with anti-basal ganglia antibodies.

Use of oral contraceptives is a recognised but infrequent cause of chorea. This type of chorea has usually been considered a reactivation of Sydenham's chorea by an unknown mechanism. A patient developed a chorea triggered by the use of oral contraceptives with no definite evidence of previous Sydenham's chorea or recent streptoccocal infections. However, the patient had positive anti-basal ganglia antibodies, which supports an immunological basis for the pathophysiology of this chorea.

Expression of caspase-activated deoxyribonuclease (CAD) and caspase 3 (CPP32) in the hydropic cochlea of guinea pigs - second report.

Apoptosis was induced in the cochlea by the injection of keyhole limpet hemocyanin (KLH) into the endolymphatic sac of guinea pigs and immunohistochemically examined. Keyhole limpet hemocyanin was injected into the right endolymphatic sac. The temporal bones were fixed via cardiac infusion of fixative and immunohistochemically stained for caspase-activated deoxyribonuclease or caspase 3. Endolymphatic hydrops became evident in the cochlea 1 day after the injection of keyhole limpet hemocyanin (n=6). The temporal bones in the control group did not show any caspase-activated deoxyribonuclease or caspase 3 immunoreactivity (n=6). Immunoreactivity for caspase 3 was detected in the supporting cells of the organ of Corti, the stria vascularis and the spiral ganglion cells. Caspase-activated deoxyribonuclease was also detected in the same areas. These findings suggest that apoptosis is involved in the pathogenesis of endolymphatic hydrops. This phenomenon could lead to cochlear dysfunction, as seen in endolymphatic hydrops.

[Dynamic of DNAse activity induction in serum of normal animals after heterogeneous DNA injection and in hereditary pathology]. / Dinamika induktsii DNKaznoi aktivnosti v syvorotke krovi zhivotnykh pri vvedenii geterogennoi DNK v norme i pri nasleduemoi patologii.

Studies of reactions in animals with hereditary diseases (Sapphire minks highly sensitive to Aleutian disease virus, ADV; CBA mice with 60-70% incidence of tumors; AKR mice with 90% incidence of leukemia) showed that serum DNAse activity in these animals dropped after injection of a foreign heterogeneous DNA and remained decreased during 72 h. By contrast, serum DNAse activity considerably and persistently increased after injection of DNA in Standard minks resistant to ADV, C57BI/6J mice with 1% tumor incidence, and random-bred albino mice. Presumably the capacity of standard minks to react to a foreign heterogeneous DNA by increase of DNAse activity ensures their resistance to DNA-containing ADV, while incapacity of Sapphire minks to respond to DNA by DNAse activity induction makes them sensitive to ADV. A similar relationship between the capacity to react to DNA by changes in serum DNAse activity and capacity to inherit a disease was detected in mouse strains.

Serologic markers of Epstein-Barr virus infection and nasopharyngeal carcinoma in Taiwanese men.

BACKGROUND: It is probable but unproven that Epstein-Barr virus (EBV) has a role in nasopharyngeal carcinoma. We determined whether antibodies against EBV are present before the development of nasopharyngeal carcinoma. METHODS: A total of 9699 men were enrolled between 1984 and 1986. Blood samples were examined for IgA antibodies against EBV capsid antigen and neutralizing antibodies against EBV-specific DNase. During 131,981 person-years of follow-up, 22 pathologically confirmed new cases of nasopharyngeal carcinoma that were diagnosed more than one year after recruitment were ascertained through linkage with the National Cancer Registry of Taiwan. RESULTS: The cumulative risk of nasopharyngeal carcinoma per 100,000 person-years was 11.2 for subjects who tested positive for neither serologic marker, 45.0 for those who had one marker, and 371.0 for those who had both markers. After adjustment for age and the presence or absence of a family history of nasopharyngeal carcinoma, the relative risk of nasopharyngeal carcinoma was 32.8 for subjects with both markers (95 percent confidence interval, 7.3 to 147.2; P<0.001) and 4.0 for subjects with one marker (95 percent confidence interval, 1.6 to 10.2; P=0.003), as compared with subjects with neither marker. The longer the duration of follow-up, the greater the difference in the cumulative incidence of nasopharyngeal carcinoma between seropositive and seronegative subjects. CONCLUSIONS: IgA antibodies against EBV capsid antigen and neutralizing antibodies against EBV DNase are predictive of nasopharyngeal carcinoma.