Porcine endogenous retrovirus (PERV) infection of HEK-293 cell line alters expression of human endogenous retrovirus (HERV-W) sequences.

The risk of infections of human recipients after xenotransplantations is now mainly represented by porcine endogenous retroviruses (PERVs) as these particles are part of the porcine genome. As in all vertebrates, human genome harbours its own numerous genetic sequences of retroviral origin; it is estimated that they comprise about 8 % of the human genome. Because some of them play an important role in human physiology, it is valuable to estimate whether the presence of PERVs in human cells influences homeostasis of the human endogenous retrovirus (HERV) expression pattern. The aim of the study was to evaluate whether the expression profile of HERV-W genes changes after infection of cells by porcine endogenous retroviruses. In the experimental settings, human embryonic kidney cell line (HEK-293) was infected by PERV particles and cultivated up to 22th passage after infection. HERV-W gag, pol and env, as well as env from locus 7q21.2 gene expression was monitored by means of realtime reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot techniques. We found that the expression level of HERV-W genes differs in PERV-infected HEK-293 cell cultures in comparison with that from non-infected cultures. Relative HERV-W gene expression also differed significantly between particular passages (P < 0.05). Moreover, we have noticed a high correlation between the HERV-W Env(7q21.2) mRNA and protein level (Spearman rank r = 0.65; P < 0.05) during the course of the experiment. As previously hypothesized, human genomic sequences of retroviral origin may be changed by the presence of porcine endogenous retroviruses.

Cytotoxic reaction mediators: granzymes A and B in women with ovarian cancer.

The purpose of this work was the assessment of cytotoxic reaction mediators - granzymes A and B in the serum of women with ovarian tumors. The study included 120 women with proven ovarian tumors. The control group consisted of 60 healthy women in whom no pathological changes within the reproductive system were detected. Concentrations of granzymes A and B were measured by enzyme-linked immunosorbent (ELISA) assay. The highest concentrations of the studied parameters were observed in serum of women with ovarian cancer. Moreover, the concentrations of granzymes A and B in patients with ovarian cancer were substantially increased in comparison to concentrations in patients with ovarian cystadenomas (P < 0.0001) or ovarian teratomas (P < 0.0001).

Efficiency of lipofection of adherent cells is limited by apoptosis.

Stability of gene expression and transfection efficiency plays the main role in the application of gene transfer method. In somatic cell gene delivery, expression of the gene product is limited by the function of the cell to which it is delivered. In the present study analyzing the lipofected adherent cells, we have shown that lower level of transgene: beta-galactosidase activity at later time period correlated with decrease in cell viability, which was shown to be due to apoptosis. Apoptosis following DNA uptake occurred only when DNA was present during lipofection.

Oral DNA vaccination promotes mucosal and systemic immune responses to HIV envelope glycoprotein.

In this report, we described induction of HIV envelope (env)-specific systemic and mucosal immune responses by oral vaccination of BALB/c mice with env-encoded plasmid DNA encapsulated in poly(dl-lactide-co-glycolide) (PLG) microparticles. We demonstrated that intragastric administration of the encapsulated plasmid DNA resulted in transduced expression of the env glycoprotein in the intestinal epithelium. Mice immunized orally exhibited env-specific type 1 and cytotoxic T lymphocyte (CTL) responses in spleen and the inductive (Peyer's patches) and effector (lamina propria) mucosal tissues of gut. Oral administration of PLG-encapsulated plasmid DNA encoding gp160 also induced env-specific serum antibodies, and an increased level of IgA directed to gp160 was detected in fecal washes of the immunized mice. In contrast, intramuscular (i.m.) administration of naked or PLG-encapsulated DNA vaccine induced only systemic cellular and humoral responses to the env glycoprotein. Using an HIV env-expressing recombinant vaccinia viral intrarectal murine challenge system, we observed higher resistance to mucosal viral transmission in mice immunized orally than in animals injected i.m. with PLG-encapsulated plasmid DNA encoding gp160. Results of these studies demonstrate the feasibility of using orally delivered PLG microparticles containing plasmid DNA-encoded HIV gp160 for induction of env-specific systemic and mucosal immune responses and protection against recombinant HIV env vaccinia virus challenge.

Antibiotic resistance in Salmonella enterica serotype typhimurium.

In order to analyse the development of antibiotic resistance in Salmonella spp., a total of 262 Salmonella strains isolated in 1987 (n = 148) and in 1996 (n = 114) from clinical specimens in Wurzburg, Germany, were tested in parallel by the agar diffusion method. In 1987. most of the strains were Salmonella enterica serotype typhimurium (42.6%), whereas in 1996 most were Salmonella enterica serotype enteritidis (68.4%). The majority of Salmonella enterica serotype enteritidis isolates was fully susceptible in 1987 and 1996. In contrast, the percentage of drug-resistant strains of Salmonella enterica serotype typhimurium increased significantly from 27% in 1987 to 52.4% in 1996. This increase, which might reflect uncontrolled use of antibiotics in the environment, should be of concern to public health authorities.

The effect of epitope variation on the profile of cytotoxic T lymphocyte responses to the HIV envelope glycoprotein.

To address the relationship between viral and host factors during HIV infection, we analyzed the effect of viral mutations on T cell responses in seropositive, asymptomatic HLA-A2+ individuals using four envelope (env)-specific peptides with the HLA-A*0201 binding motif. We showed that the natural sequence variation was frequent within epitopes located in the C-terminal region of the env glycoprotein and was largely responsible for a lower env-specific cytotoxic T lymphocyte (CTL) activity in the peptide-stimulated cultures. The highest CTL responses in vitro were induced with conserved epitopes D1 and 4.3 that mapped to the N-terminal region of the env glycoprotein. These peptides exhibited high binding affinity for HLA-A*0201 molecules and stimulated CD8+ T cells of relatively limited TCR Vbeta chain repertoire. Decreased CTL activities to the D1 epitope were observed in the absence of any detectable viral mutation, and were associated with lower proliferative responses and expression of the CD28 antigen. Results of this study demonstrate that the degree of sequence variation within a stimulatory epitope of the viral quasispecies, as well as proliferative potential of the effector cells, are among the factors underlying decreased CTL activity in HIV-infected patients. These experiments also provide evidence that the D1 peptide might be useful for the development of vaccines and immune-based therapy.

A cholera-like illness in a traveller due to a mixed infection with enterotoxigenic Escherichia coli, Vibrio parahaemolyticus and Pseudomonas aeruginosa.

A healthy 67-year-old male traveller developed a cholera-like disease after returning from a five-week stay in Pakistan and India. In addition to Vibrio parahaemolyticus and large numbers of Pseudomonas aeruginosa, two strains of enterotoxigenic Escherichia coli were isolated from a single stool specimen.

[Incidence of intestinal disease due to Yersinia enterocolitica (author's transl)]. / Zur Häufigkeit von Darmerkrankungen durch Yersinia enterocolitica.

Enteropathogenic bacteria have been identified in 413 of 7054 patients (5.9%) with intestinal disease who were examined at the Institute of Hygiene and Microbiology, University of Würzburg (South Germany), during the period November 1975 to November 1977. Salmonella was most frequently isolated (304 cases = 4.3%), followed by Yersinia enterocolitica (102 cases = 1.5%). Cases of shigellosis (7 cases) or infections with so-called enteropathogenic serogroups of Escherichia coli (20 cases) were rarely observed. Disease due to Yersinia enterocolitica occurred in 57 male and 45 female patients. Sixty-two patients were children of less than 15 years; among them, the age-group of 1 to 3 years (31 cases) was most frequently attacked. -Mild to severe enteritis was prevalent in 84 cases. Thirteen patients developed pseudo-appendicitis or abdominal cramps without diarrhea, three of whom had appendectomies. One female patient suffered from mild diarrhea followed by fever and arthritis; in three other subjects intestinal symptoms were lacking. In the two years' period the highest incidence of salmonellosis was observed during August to October. On the other hand, most Yersinia cases occurred during September to December. At the end of the year (December 1976 and November 1977, respectively) Yersinia enterocolitica became the most important agent of bacterial enteritis. The results are discussed in view of the current Federal German Public Health Regulations.

[Three new serotypes of Salmonella subgenus I and four serological variants (author's transl)]. / Drei neue Serotypen des Salmonella-Subgenus I und vier serologische Varianten

The Salmonella strains described in this paper were isolated from clinical and environmental sources in Togo (West Africa). All strains belong to subgenus I of the genus Salmonella. 1. Salmonella kodjovi 47:c:-, Supplement No. XVII (1974), isolated from stool specimen 2. Salmonella dadzie 51:1, v:e, n, x, Supplement No. XVII (1974), isolated from stool specimen 3. Salmonella mono 4, 12:1, w:1, 5, Supplement No. XVII (1975), isolated from pig droppings 4. Salmonella chincol var. s-, monophas. 6, 8:g, m:-, Supplement No. XVIII (1975), isolated from lizard intestines 5. Salmonella chicago var. i+, 28:r, i:1,5, Supplement No. XVIII (1975), isolated from stool specimen 6. Salmonella havana var. s+, 36+, 13,23:f,g,s:-, Supplement No. XVIII (1974), isolated from stool specimen 7. Salmonella elisabethville var. 15+, 3,15:r:1,7, isolated from lizard intestines.

Butandioldehydrogenase in Vibrio parahaemolyticus.

396 strains of V. parahaemolyticus, 345 originating from Togo and 51 from Japan, were submitted to the study of butandiol dehydrogenase (BDH). It was found that 52.3% of the strains were BDH-positive and 44.2% BDH-negative. An intermediate group characterized by weak reactions amounted to 3.5% of the strains. The distribution of this enzyme parallels to a certain degree the results of serotyping. Positive reactions have been found in all or most strains belonging to serotypes 03K29, O4K8, 04K12, 04K55, 05K15, and 012K19, whereas strains of serotypes 03K5 and 04K10 gave negative reactions. In serotype 05K17 both properties were found in nearly equal proportions. The test of BDH, which can supplement serotyping in characterizing strains of V. parahaemolyticus, can be applied as an aid to epidemiological studies.

[Utilization of LIN (lysine-indole-motility) medium for the preliminary identification of enteropathogenic bacteria]. / Die Verwendung von LIM (Lysin-Indol-Motilitäts) -Medium zur primären Identifizierung pathogener Darmbakterien

A multiple-test medium for the routine laboratory identification of enteropathogenic bacteria is described. The medium has the following formula: Bacto-peptone (Difco) 5 g; yeast extract (Difco) 3 g; casein tryptic digest peptone (Merek) 15 g; glucose 1 g; L-lysine-monohydrochloride (Merck, No. 5700) 5 g; NaCl 5 g; bromcresol purple 0.016 g; agar 2 g; distilled water 1000 ml; final pH 6.6. The medium is dispensed in amounts of 5 ml into tubes of 14 X 85 mm and autoclaved at 120 degrees C for 10 min. The tubes are tightly closed with rubber stoppers. - The medium is inoculated by stabbing to the bottom of the tube. Readings are made after over-night incubation at 37 degrees C. A scheme for the preliminary identification of enteropathogenic bacteria is given, based on LIM medium in conjunction with Kligler's iron agar, and the oxidase reaction.