PubMed Health⌕ Search

Biomedical subjects

I Hennig

Publications and source records attributed to I Hennig.

16 recordsLinked to original sources
PubMed1999

Downregulation of a protective Actinobacillus pleuropneumoniae antigen during the course of infection.

The persistence of Actinobacillus pleuropneumoniae in convalescent pigs significantly contributes to the distribution of disease. The downregulation of protective antigens in vivo as one possible mechanism responsible for this phenomenon was investigated using the small iron-regulated transferrin binding protein (TbpB-protein) as exemplary protective antigen. From a total of 21 pigs experimentally infected with A. pleuropneumoniae serotype 7 in three trials, bronchoalveolar lavage fluid (BALF) was obtained on day 1 or 2, day 7, day 14 and day 21. Employing double immunofluorescence of BALF with a monoclonal anti-TbpB antibody and an A. pleuropneumoniae -specific anti-polysaccharide antiserum a statistically significant decrease of the percentage of A. pleuropneumoniae bacteria strongly expressing TbpB protein was observed during the course of infection. These results were supported by in vitro incubation of A. pleuropneumoniae in medium supplemented with BALF. In addition, it was found that TbpB-expression in BALF from day 7 after infection could not be inhibited by the substitution of iron. These results suggest (i) the downregulation of protective antigens is one possible mechanism allowing bacterial persistence, (ii) in vitro induction in the presence of BALF mimics the in vivo situation, and (iii) TbpB expression is additionally regulated by an iron-independent mechanism.

Actinobacillus Infections↗
PubMed1998

The phantom.

Explore the source record for details and available documents.

Adult↗
PubMed1998

[Clinical and laboratory diagnostic findings in chronic pleuropneumonia of swine].

In the course of an experimental study 12 pigs were infected intrabronchially with the pathogen of infectious porcine pleuropneumonia, Actinobacillus pleuropneumoniae. All animals survived the acute stage of infection due to the application of subtherapeutic doses of antibiotics. After infection all of the animals showed clinical signs of acute pneumonia with an elevation of body temperature to about 41 degrees C. Bronchoalveolar lavage fluid (BALF) was taken every week endoscopically. An increase of neutrophil granulocytes could be observed at day 7 and 14 after infection. In parallel, a clear granulocytosis and a shift to the left of the nuclei was observed at day 7. Comparing the methods for detection of Actinobacillus pleuropneumoniae serological assays like the complement-fixation assay (CFA) and enzyme-linked immunosorbent assay (ELISA) as well as immunofluorescence in lung tissue and BALF were more sensitive than cultural isolation from lung tissue, tonsils and BALF.

Actinobacillus Infections↗
PubMed1996

Local up-regulation of neuropeptide receptors in host blood vessels around human colorectal cancers.

BACKGROUND & AIMS: Neuropeptide receptors, expressed at high density by neoplastic cells, can be instrumental for diagnosis and therapy. However, little is known about neuropeptides and neuropeptide receptors in the tumor bed. The aim of this study was to study the expression of two neuropeptide receptors in peritumoral blood vessels. METHODS: Somatostatin and substance P receptors were measured using in vitro receptor autoradiography in well-defined submucosal and subserosal vessels located in the immediate surroundings of human colorectal carcinomas or in normal colon taken at increasing distances from the tumor. RESULTS: Both receptors were 3-5-fold overexpressed in the host veins within a 2-cm-wide area surrounding human primary colorectal carcinomas compared with veins located at 5-10-cm distance in normal gut tissue. The expression of peritumoral vascular somatostatin receptor and substance P receptor appears independent of receptor expression in the tumor, of tumor stage, and of the grade of local inflammation. CONCLUSIONS: These biochemical alterations of veins in the immediate vicinity of tumors represent a novel tumor-related site of expression for the two receptors and may point to a new biological principle of host-tumor interaction. Thus, vascular regulatory mechanisms in the tumor bed may be important for tumor development and metastasis and may be used as a target for tumor therapy.

Aged↗
PubMed1995

Interleukin-12 expression in human lymphomas and nonneoplastic lymphoid disorders.

Interleukin-12 (IL-12), a cytokine with in vitro and in vivo immunomodulatory effects, is produced by lymphocytes and stimulated monocytes. Little is known about the production and possible role of IL-12 in human lymphoproliferative disorders. We examined IL-12 expression by immunohistochemistry using antibodies recognizing the p40, p35 subunits, and the p70 heterodimeric IL-12 protein, and by Northern blot in lymph nodes from patients with Hodgkin's disease (HD), non-Hodgkin's lymphomas (NHL), and nonneoplastic lymphoid lesions. In the majority of the HD cases (28 of 34), IL-12 immunoreaction was found in small lymphoid cells cultured around Hodgkin and Reed-Sternberg (H&RS) cells. No IL-12 signal was seen in H&RS cells. Transcripts for IL-12 were found by Northern and dot blot analysis in 13 of 19 (IL-12 p40) and 11 of 19 (IL-12 p35) cases. The HD cases were further examined for the presence of Epstein-Barr virus (EBV) latent membrane protein (LMP-1). All cases with EBV-LMP-1 positivity (22 of 34 cases) also expressed IL-12. No IL-12 immunoreaction was found in neoplastic cells of 33 cases of various NHLs, which were all LMP-1 negative and showed no EBV-genome sequence, as assessed by polymerase chain reaction (PCR). In 24 nonneoplastic lymphoid lesions, few dispersed IL-12 positive cells were seen in the parafollicular area and in the sinus of the lymph node. The marked presence of IL-12 in the majority of HD cases indicates that IL-12 might play a role in the pathobiology of HD, suggesting that this cytokine is involved in EBV-positive HD.

Biomarkers↗
PubMed1994

EBV T-cell lymphoma.

Explore the source record for details and available documents.

Herpesviridae Infections↗
PubMed1993

Association of the subtype 2 of the Epstein-Barr virus with T-cell non-Hodgkin's lymphoma of the midline granuloma type.

Lethal midline granuloma (LMG) is associated with Epstein-Barr virus (EBV). The latter has at least two subtypes with different biological properties. The subtypes can be identified by their genomic configuration. Using EBV-RNA (EBER) in situ hybridization and EBV polymerase chain reaction (PCR), we have looked for the presence of EBV in six LMGs and six non-Hodgkin's lymphomas (NHLs) located in the nasopharyngeal region, and determined the subtype of EBV. Six of six LMGs were positive by PCR and EBER in situ hybridization, whereas NHLs were either negative or, in three of six cases, showed few EBER-positive cells considered to be nonneoplastic lymphocytes. The subtype 2 was found in LMG lesions of three of six patients; the remaining three of six patients with LMG had the generally occurring subtype 1. The results indicate that the association of EBV with NHL may depend more on tumor type than on its localization. The occurrence of the rare subtype 2 in LMG may relate to a covert immune defect.

Aged↗
PubMed1993

Mitotic stability of fragile X mutations in differentiated cells indicates early post-conceptional trinucleotide repeat expansion.

We demonstrate here that somatic variation of CGG repeat length is based on a mosaic of cells with different but stable FMR-1 alleles and does not reflect permanent mitotic instability. The length of a particular allele in an individual cell was maintained in progeny cells establishing a clone. The mutation patterns of multiple repeats in the DNA of fetal tissues were identical and did not significantly change during proliferation in vitro. It is proposed that genotype mosaicism and expansion to full mutation are generated post-conceptionally by the same molecular mechanism in a particular window of early development.

Alleles↗
PubMed1992

Distribution and localization of Epstein-Barr virus subtypes A and B in AIDS-related lymphomas and lymphatic tissue of HIV-positive patients.

Tissue samples of 21 HIV-positive patients have been studied for the presence and distribution of Epstein-Barr virus (EBV) subtypes A and B. This was done by PCR, EBER in situ hybridization, and immunohistochemical detection of EBV latent membrane protein (LMP) in AIDS-associated malignant lymphomas (16 cases) and lymphatic organs of patients without lymphoma (5 cases). Eleven cases were considered to be EBV-positive, with type A in four, and type B virus in four other cases. In patients with malignant lymphoma, EBV was localized in tumour tissue exclusively. One patient without lymphoma presented with multiple EBV genome type B-positive cells in all the lymphoid tissue samples examined. In HIV-positive patients, both subtypes of EBV, A and B, may play a role in the pathogenesis of lymphoproliferative lesions.

Adult↗
PubMed1992

Enteropathy-associated T-cell lymphoma in a renal transplant patient with evidence of Epstein-Barr virus involvement.

The clinical and histological findings in a 54-year-old patient with enteropathy-associated T-cell lymphoma (EATL) occurring 18 years after renal transplantation are presented. Ten years after adult-onset coeliac disease the patient developed medium to large T-cell non-Hodgkin's lymphoma of the small intestine. Epstein-Barr virus (EBV) genome was detected by polymerase chain reaction in the lymphoma tissue and localized via Epstein-Barr virus RNAs in situ hybridization to some of the tumour cells. This is the first case report of EBV-positive EATL occurring in the setting of immunosuppression.

Base Sequence↗
PubMed1992

[The EBNA2 coding region in the viral genome of Epstein-Barr virus (EBV)-positive cases of Hodgkin's disease].

Epstein-Barr virus (EBV)-genome containing cases of Hodgkin's disease (HD) are known to express latent membrane protein (LMP) of EBV but no EBV nuclear antigen 2 (EBNA2). We investigated 35 cases of HD for the presence of EBV genome sequences to know whether EBNA2 coding region is deleted in HD. 27 cases had general EBV sequences, none had evidence of a deletion of EBNA2. 26 cases turned out to harbour EBV type 1, one case had EBV type 2. The absence of EBNA2 protein expression in HD can not be explained by a deletion of EBNA2 coding region. EBV type 1 is the prevalent subtype of EBV in our series of HD.

Acquired Immunodeficiency Syndrome↗
PubMed1982

"Hybrid" X--Y translocation chromosomes of Drosophila hydei and D. neohydei.

The Y chromosome of Drosophila carries fertility genes which, in part, develop lampbrush loops during the meiotic prophase. Hybrid males from crosses between D. hydei and D. neohydei are fertile although the morphology of the lampbrush loops differs between both species. With the aid of X ray induced "hybrid" X-Y translocation chromosomes the question has been studied whether Y chromosomal genes of D. neohydei can substitute deletions in the Y chromosome of D. hydei. Although the induction of translocation chromosomes almost regularly results in an inactivation of the translocated Y fragment within a few generations, one case of successful complementation has been demonstrated. Furthermore, a new lampbrush loop pair has been detected in D. neohydei which is morphologically similar to the "nooses" of D. hydei. Preliminary evidence for the location of the lampbrush loops on the Y chromosome of D. neohydei is discussed.

Drosophila↗
PubMedDate not supplied

DIABETEX decision module 2--calculation of insulin dose proposals and situation recognition by means of classifiers.

Current research in the field of medical decision making tries to represent and to analyse complex, uncertain and complicated situations. The first version of DIABETEX, which is a decision support system for the treatment of diabetic out-patients, accepts the challenge to overcome these difficulties. It includes a network of rules on the basis of known glucose-insulin relationships under different situations. The insulin dose for type I diabetic patients is suggested accordingly. In this, the application of special cybernetic methods offers the chance to overcome complexity, uncertainty, fuzzyness and incompleteness of data. Two methods of classification are presented to complete the DIABETEX decision unit: (1) the Bayes' classification is used in the calculation of insulin doses for type I diabetic patients on multiple subcutaneous insulin injections considering the basis-bolus concept; (2) fuzzy classification is employed in separating 'normal diabetic days' from days with information on special situations such as exercise, illness, menstruation on the one side, from stress, hypoglycaemia etc. on the other.

Bayes Theorem↗