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C Kunz

Publications and source records attributed to C Kunz.

At least 127 records · Page 7Linked to original sources
PubMed1991

The relationship between the flaviviruses Skalica and Langat as revealed by monoclonal antibodies, peptide mapping and RNA sequence analysis.

The flavivirus Skalica was isolated from a bank vole in Czechoslovakia in 1976. It can be serologically distinguished from prototype strains of tick-borne encephalitis (TBE) virus and has a decreased virulence for adult mice. We have further defined the relationship of Skalica virus to other members of the TBE serocomplex (TBE European and Far Eastern subtypes, Langat and louping ill virus) by using a panel of 22 monoclonal antibodies, peptide mapping and RNA sequence analyses. By these criteria Skalica virus proved to be distinct from TBE virus and to be very closely related to Langat virus, differing by only two bases among a total of 416 nucleotides compared. The sequence of 22% of the Langat genome was determined and the encoded amino acid sequences were derived. Comparison of these with the corresponding amino acid sequences of TBE virus revealed a similarity of 85%, as opposed to 93% similarity between the European and Far Eastern subtypes of TBE virus.

Amino Acid Sequence↗
PubMed1991

Fusion activity of flaviviruses: comparison of mature and immature (prM-containing) tick-borne encephalitis virions.

The fusion activity of flaviviruses [tick-borne encephalitis (TBE) virus and Japanese encephalitis virus] was assessed by inducing fusion from without of C6/36 mosquito cells with purified virus preparations. Membrane fusion and polykaryocyte formation was observed only after incubating the viruses at acidic pH. Two groups of monoclonal antibodies reacting with distinct non-overlapping antigenic domains on the TBE virus protein E inhibited fusion from without. One of these domains contains the most highly conserved and putative fusion-active sequence of the flavivirus protein E. Of five TBE virus monoclonal antibody escape mutants, each defined by a single amino acid substitution in the envelope protein E, one revealed a reduced fusion activity and another one a lower pH threshold. TBE virus grown in the presence of ammonium chloride as well as Langat virus purified from the supernatant of infected chick embryo cells contained the precursor of protein M (prM) rather than M itself. These 'immature' virions did not cause fusion from without, suggesting that the proteolytic processing of prM may be necessary for the generation of fusion-competent virions.

Aedes↗
PubMed1991

Detection of varicella-zoster virus DNA by polymerase chain reaction in the cerebrospinal fluid of patients suffering from neurological complications associated with chicken pox or herpes zoster.

The polymerase chain reaction (PCR) was used to detect varicella-zoster virus (VZV) DNA in the cerebrospinal fluid of patients with VZV infection associated with neurological symptoms. Positive results were obtained in three of five children with post-chicken pox cerebellitis and in seven of seven herpes zoster patients with neurological symptoms. The PCR thus provides a useful tool for the early diagnosis of VZV-associated neurological disease.

Chickenpox↗
PubMed1991

The flavivirus envelope protein E: isolation of a soluble form from tick-borne encephalitis virus and its crystallization.

By the use of limited trypsin digestion of purified virions, we generated a membrane anchor-free and crystallizable form of the tick-borne encephalitis virus envelope glycoprotein E. It retained its reactivity with a panel of monoclonal antibodies, and only subtle structural differences from the native protein E were recognized. Treatment with the bifunctional cross-linker dimethylsuberimidate resulted in the formation of a dimer. Crystallization experiments yielded hexagonal rod-shaped crystals suitable for X-ray diffraction analysis.

Amino Acid Sequence↗
PubMed1991

Presence of poly(A) in a flavivirus: significant differences between the 3' noncoding regions of the genomic RNAs of tick-borne encephalitis virus strains.

A poly(A) tail was identified on the 3' end of the prototype tick-borne encephalitis (TBE) virus strain Neudoerfl. This is in contrast to the general lack of poly(A) in the genomic RNAs of mosquito-borne flaviviruses analyzed so far. Analysis of several closely related strains of TBE virus, however, revealed the existence of two different types of 3' noncoding (NC) regions. One type (represented by strain Neudoerfl) is only 114 nucleotides long and carries a 3'-terminal poly(A) structure. This was also found in several TBE virus strains isolated from different geographic regions over a period of almost 30 years. The other type (represented by strain Hypr) is 461 nucleotides long and not polyadenylated. The sequence homology between the two types of TBE virus 3' NC regions terminates at a specific position 81 nucleotides after the stop codon. The second type of 3' NC region more closely resembles the common flavivirus pattern, including the potential for the formation of a 3'-terminal hairpin structure. However, it lacks primary sequence elements that are conserved among other flavivirus genomes.

Animals↗
PubMed1991

[Early summer meningoencephalitis vaccination, a preventive medicine measure with high acceptance in Austria].

The vaccination against Tick-borne encephalitis (TBE) was accepted by the Austrian population on a broad scale. Of the estimated 5 million Austrians at risk of TBE, as of 1987 only 1.7 million were unvaccinated. From the very small number of TBE cases despite vaccination we were able to calculate a protection rate of 95% after 2 vaccinations and of 99% after 3 or more vaccinations. Since 1984 as a consequence of the vaccination campaign a steady decline of TBE could be observed in Austria. More than 10 years ago improved procedures enabled the production of a highly purified vaccine, thus reducing the number of side effects to a minimum. We here present data from 2067 vaccinees who reported on eventual side reactions by means of a questionnaire. The reactions reported did not exceed those which could be expected after application of a placebo vaccine. Due to high immunogenicity of the vaccine a booster effect can be achieved even some years after a missed vaccination, precluding the necessity of beginning a new series.

Antibodies, Viral↗
PubMed1990

Surveillance of viral respiratory tract infections over a one year period in mainly hospitalized Austrian infants and children by a rapid enzyme-linked immunosorbent assay diagnosis.

In order to obtain more information on viral respiratory tract infections in Austrian infants and children, nasopharyngeal secretions from 1432 infants and children, collected from October 1984 to October 1985, were screened for the presence of respiratory syncytial virus (RSV), adenoviruses, parainfluenza virus type 1, 2, and 3, and influenza viruses type A and B, by enzyme-linked immunosorbent assay (ELISA). The results obtained were analyzed with respect to incidence, seasonal distribution and clinical syndromes associated with the different viral pathogens investigated and also with the practicability of ELISA diagnostics over long distances. A viral etiology of acute respiratory tract infection was confirmed in 372 (26%) infants. RSV was detected in 286 (20%) of the nasal secretions and was thus the most frequently encountered agent. RSV infections occurred mainly in the winter months and were often associated with bronchitis, bronchiolitis, and pneumonia. Only sporadic infections were found with one of the other viruses investigated.

Adenoviruses, Human↗
PubMed1990

[Testing for hepatitis C].

Over the past 10 years, 12,146 cases of hepatitis were diagnosed in the Virology Department of Vienna University. 30.3% were hepatitis A, 39.2% hepatitis B, 3.0% cytomegalovirus and 1.5% Epstein-Barr virus infections. The remaining 25.8% were diagnosed as non-A, non-B hepatitis (NANB). Therefrom, a sample of 167 sera from acute and 78 from chronic hepatitis NANB were tested for hepatitis C. 9.6% of the acute and 44.9% of the chronic cases were positive. We conclude from these data that about 12% of all hepatitis cases in Austria are caused by the hepatitis C virus. In addition, risk groups for hepatitis C were tested. The highest prevalence (80%) was found in drug addicts. Polytransfused (organ transplanted) patients had antibodies in 44.8% of cases. Of 78 dialysis patients, 7 were positive but nearly all positives came from one single dialysis unit, thus indicating a prevalence of 30% there.

Adult↗
PubMed1990

[HIV infection and AIDS in Austria].

AIDS is a notifiable disease in Austria. Until August 31, 1989, a total of 324 cases were recorded, with 145 deaths. Since 1988, the annual doubling of cases that was initially found is no longer observed. Centralization of confirmatory testing of samples that are positive in the ELISA permits us to follow up the incidence and prevalence of HIV infections. By September 15, 1989, a total of 3,071 persons were found to be infected. The highest rates of AIDS patients and seropositive individuals were recorded in Vienna (151/1,712), followed by Upper Austria (63/606) and the Tyrol (29/367). Among those found to be positive since October 1987, 28% are homo- or bisexual and 42% are i.v. drug addicts. About 4% of men and women report heterosexual contacts as the likely mode of infection. Since 1986 the yearly incidence of HIV infection appears to be decreasing. This development corresponds with a decline in other sexually transmitted diseases (gonorrhoea, hepatitis B) and indicates a change in the sexual behaviour of the population.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Establishment of PCR for the early diagnosis of herpes simplex encephalitis.

The early detection of herpes simplex encephalitis (HSE) represents a major problem in viral diagnostics. We have now established a test system based on PCR for the specific amplification of HSV-DNA in cerebrospinal fluid (CSF) samples followed by oligonucleotide hybridization. The test proved to be very sensitive. Five molecules of HSV 1 DNA still yielded positive signals after hybridization. The assay was applied to CSF samples from 6 patients with confirmed HSE. All except one CSF sample obtained from the 2nd to the 8th day after onset of neurological symptoms yielded positive results. The primers used also exhibit a certain degree of crossreactivity with HSV 2, as revealed by testing of a CSF sample from an HSV 2-infected child. No positive signals were obtained with human DNA and with DNA from CMV- and VZV-infected fibroblasts. Also 42 CSF samples of patients suffering from other diseases of the CNS yielded negative results. The present results indicate that the detection of HSV DNA in CSF by PCR represents a valuable tool for the early diagnosis of HSE.

Antibodies, Viral↗
PubMed1990

Viral reactivation as a cause of unexplained fever in patients with progressive metastatic breast cancer.

Patients suffering from metastatic breast cancer and recurrent fever were investigated for viral reactivation or new viral infection as a possible cause of these febrile episodes. Three groups of patients were included in the study: (a) patients under adjuvant chemotherapy with cyclophosphamide, methotrexate and fluoruracil, (b) patients with stable metastatic disease treated with cyclophosphamide, fluoruracil and Adriamycin or mitoxantrone and (c) patients with progressive metastatic disease who also received the latter treatment. During the time of observation, patients under adjuvant chemotherapy did not present with fever or asymptomatic viral reactivation or bacterial infections at all. Out of 7 patients with stable disease, 2 had bacterial infections that coincided with the leukocyte nadir, and 1 presented with asymptomatic reactivation of cytomegalovirus. In contrast, fever in 9 of 11 patients with progressive disease was associated with a reactivation of herpes simplex virus (HSV) and in 3 of them with a consecutive reactivation of varicella zoster virus (VZV). The increase in complement-fixing anti-HSV or anti-VZV antibodies occurred in close association with a rise of the respective preexisting antibodies of the IgG class. In addition, HSV-infected cells were recovered from the urine of 7 patients with progressive disease further corroborating the serological data. Incidentally, natural killer cell activity, which has been postulated to be connected with the defense against viral infections, was found to be significantly lower in the group of patients with progressive disease, as compared to the group of patients under adjuvant chemotherapy (P less than 0.05) or to the group of patients with stable disease (P less than 0.05). We conclude that unexplained fever in patients with progressive metastatic breast cancer may result from viral reactivation.

Antibodies, Viral↗
PubMed1990

Safety and immunogenicity of an inactivated hepatitis A candidate vaccine in healthy adult volunteers.

The reactogenicity and immunogenicity of a formaldehyde-inactivated hepatitis A vaccine have been investigated. Three different dose levels of vaccine (180, 360 and 720 ELISA units) were administered to healthy volunteers according to a 0, 1, 2 and 12 month schedule. The vaccine was safe and well tolerated. Reactions observed following vaccination were essentially mild and were not dependent upon the quantity of antigen administered. All subjects had measurable titres of anti-HAV antibodies after the full vaccination course; the immune response to the vaccine was dose-related. Antibody titres in vaccinees at month 13 were between 60- and 190-fold higher than those observed in a group of subjects given anti-HAV immunoglobulin.

Adolescent↗
PubMed1990

Antibody response to gp E of tick-borne encephalitis virus: comparison between natural infection and vaccination breakdown.

Human sera obtained after tick-borne encephalitis (TBE) without prior vaccination were compared with sera from patients after a vaccination breakdown. Most sera previously shown to have high titers of IgG and IgM against TBE virus as detected in the ELISA and hemagglutination inhibition (HI) tests also reacted in Western blot with TBE virus E protein which is involved in virus neutralization. The serum of a patient with a vaccination breakdown, however, reacted only very weakly with the E protein in the Western blot in spite of a high amount of antibodies detectable in ELISA. Using SDS-denaturated virus as an antigen in ELISA (imitating the blotting condition), this serum revealed a significant reduction in its reactivity with denatured virus compared to the control sera. This indicates that the patient had an insufficient immune response against certain denaturation resistant epitopes which might contribute to development of disease despite vaccination. The analysis of the immune response of human sera at the epitope level revealed a characteristic "fingerprint" for each serum reflecting the genetic control of the production of antibody populations against different antigenic determinants.

Antibodies, Viral↗
PubMed1990

Relevance of hepatitis B DNA detection in patient's serum.

Detection of HBV-DNA showed a satisfactory sensitivity (6 pg/ml) and high specificity: 15 patients with hepatitis A, 6 with CMV, 7 with EBV infection, 81 with hepatitis NANB as well as 174 persons with isolated HBc antibodies and 9 hepatitis B vaccinees gave negative results. However, out of 118 persons with a history of hepatitis B (HBs and HBc antibodies positive), one repeatedly had a positive result. We followed 58 patients with chronic hepatitis B, 25 healthy antigen carries, and 16 HBV-infected dialysis patients over an extended period with multiple blood sampling. Most of those patients showed changes of detectability of HBV-DNA. Typically, periods with positive DNA tests were followed by intervals with negative tests which could last for up to a few years. 75% of dialysis patients were positive in all sera available, while 48% of healthy antigen carriers were consistently negative. Additionally, 9 patients with a history of recent hepatitis B and a positive HBs antibody test as well as 4 patients with simultaneous infection by A and B were tested for HBV-DNA. In none of these two groups, a variation from the pattern usually found in hepatitis B was established. A case of intrauterine infection with hepatitis B virus is reported. Because the blood of the mother was free from HBV-DNA and HBe antigen at delivery and because the hepatitis B immunoglobulin prophylaxis failed in the child who developed HBs antigen very soon after delivery, it has been concluded that the child was infected in utero. The highest values of HBV-DNA determined quantitatively were found in dialysis patients which explains the high risk of acquiring hepatitis B in the dialysis unit. The results from earlier studies on the prognostic relevance of HBV-DNA and the risk of medical personnel as a source of infection with hepatitis B are discussed briefly.

Chronic Disease↗
PubMed1990

Human-milk proteins: analysis of casein and casein subunits by anion-exchange chromatography, gel electrophoresis, and specific staining methods.

Casein in human milk is believed to serve several biological functions in newborns. However, the content and subunit composition of human casein has so far received little attention. We recently developed a method to separate human-milk whey and casein by adjustment of whole human milk to pH 4.3 and addition of calcium followed by ultracentrifugation. In this study we analyzed and evaluated human casein prepared by different methods. We used fast protein liquid chromatography (FPLC) with an anion-exchange column (Mono-Q) and polyacrylamide gradient gel electrophoresis techniques to analyze the casein subunit composition. Total casein in human milk, as determined by the Kjeldahl method, varies during lactation; the casein content is approximately 20% of the total protein content in early lactation and 45% in late lactation. We found differences in both glycosylation and phosphorylation patterns of kappa-caseins and beta-caseins from premature and term milk samples.

Caseins↗
PubMed1990

Casein and casein subunits in preterm milk, colostrum, and mature human milk.

Human milk proteins have both nutritional and physiological roles for the breast-fed infant. While the biochemistry and developmental patterns for many whey proteins are well known, our knowledge of human casein and its subunits is still limited. We have recently developed a method to isolate casein from whey proteins in human milk and to separate the casein subunits by fast protein liquid chromatography. In this study we have applied this methodology to study the casein subunit pattern in preterm milk, colostrum, and mature milk. Casein concentration increased with lactation time, largely due to an increase in glycosylated forms of casein (kappa-caseins). Thus, the relative proportion of beta-casein to kappa-casein decreased during the lactation period. The patterns of phosphorylated and glycosylated casein subunits were found to vary during lactation, showing that both synthesis and posttranslational modification of beta- and kappa-casein are regulated by different mechanisms.

Adult↗