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Biomedical subjects

A Back

Publications and source records attributed to A Back.

At least 19 recordsLinked to original sources
PubMed2004

Isolation and characterization of Ornithobacterium rhinotracheale from chickens in Brazil.

Ornithobacterium rhinotracheale (ORT) is a recently described species of bacterium associated with respiratory disease, growth retardation, mortality, and decreased egg production in chickens and turkeys. Pneumonia, pleuritis, and airsacculitis characterise the infection. ORT has been isolated in many countries but it is still considered exotic in Brazil. Up to date it is prohibited to import and produce reagents for diagnostic and vaccination control. The aim of this study was to isolate and identify the bacteria in chickens. Four isolates were obtained from tracheal swabs of broilers. They were isolated in blood agar with gentamicin and showed biochemical, morphological, antigenic and genetic characteristics of ORT. The results confirm that ORT is present in Brazil.

Animals↗
PubMed1998

Application of recombinant fimbrial protein for the specific detection of Salmonella enteritidis infection in poultry.

A number of disease outbreaks of Salmonella enterica serotype enteritidis (SE) in humans have been traced to the consumption of SE-contaminated egg and egg products. A rapid, specific, and inexpensive method of detecting SE infection in poultry is necessary to reduce human outbreaks. We evaluated rSEF14 fimbrial antigen of SE for specific detection of SE-infected birds in latex agglutination test and enzyme-linked immunosorbent assay. rSEF14 antigen was highly specific in identifying birds infected with SE. The sera from birds infected with closely related serogroup-D Salmonella and other avian pathogens did not react with rSEF14 antigen. The rSEF14 antigen identified antibodies in serum of 88% of birds during the first 2 weeks of infection, and 100% of the birds subsequently. The SE-specific antibodies were detected in egg yolk as early as 6 days post-infection in rSEF14-enzyme-linked immunosorbent assay. Our results suggest that rSEF14-based assays could be used as screening tests for detection of SE antibodies and would overcome the cross reactions observed with existing serological tests.

Amino Acid Sequence↗
PubMed1998

SERE, a widely dispersed bacterial repetitive DNA element.

The presence of a Salmonella serotype Enteritidis repeat element (SERE) located within the upstream regulatory region of the sefABCD operon encoding fimbrial proteins is reported. DNA dot-blot hybridisation analyses and computerised searches of genetic databases indicate that SERE is well conserved and widely distributed throughout the bacterial and archaeal kingdoms. A SERE-based polymerase chain reaction (SERE-PCR) assay was developed to fingerprint 54 isolates of Enteritidis representing nine distinct phage types and 54 isolates of other Salmonella serotypes. SERE-PCR identified five distinct fingerprint profiles among the 54 Enteritidis isolates; no correlation between phage types and SERE-PCR fingerprint patterns was noticed. SERE-PCR was reproducible, rapid and easy to perform. The results of this investigation suggest that the limited heterogeneity of SERE-PCR fingerprint patterns can be utilised to develop serotype- and serogroup-specific fingerprint patterns for isolates of Enteritidis.

Animals↗
PubMed1995

Leukocyte integrin CD11b promoter directs expression in lymphocytes and granulocytes in transgenic mice.

The human leukocyte integrin subunit CD11b is expressed predominantly on myelomonocytic cells. To identify CD11b promoter sequences important for myelomonocytic gene expression and to assess the utility of the CD11b promoter for expressing heterologous genes in vivo, we generated transgenic mice with a human CD4 reporter gene driven by CD11b promoter constructs composed of 1.5, 0.3, or 0.1 kb of DNA sequence 5' to the transcription start site. Using flow cytometry to detect the human CD4 reporter on murine leukocytes, two of three 1.5-kb CD11b promoter founder lines showed surface expression of the human CD4 transgene in granulocytes and lymphocytes. The transgene expression observed in lymphocytes was inappropriate relative to the normal pattern of CD11b expression. Of the eight 0.3-kb or 0.1-kb founder lines, only one 0.1-kb founder line showed transgene expression. The overall pattern of transgene expression among the 11 founder lines does not parallel expression of the endogenous CD11b gene. These studies indicate that additional CD11b regulatory elements will be required to express a reporter gene in vivo in a lineage-specific pattern that mimics the endogenous CD11b gene.

Animals↗
PubMed1994

[Intensification of sensitivity of monoclonality determination of B-cells in autoimmune thyroiditis and low malignancy B-NHL of the MALT type using temperature gradient gel electrophoresis (TGGE)].

Malignant non-Hodgkins lymphoma with primary involvement of the thyroid is a rare disease. Nearly all these lymphomas are of B-cell phenotype, and they represent a broad morphological spectrum of high and low grade entities. We investigated 18 cases of Hashimotos disease and 95 cases of thyroid non-Hodgkins lymphoma including 16 cases of MALT-lymphoma. This type of lymphoma is often hardly distinguishable from reactive lesions, even by immunohistochemistry. Therefore, we introduced a new molecular genetic technique based on the polymerase chain reaction (PCR) combined with temperature-gradient gel electrophoresis to demonstrate monoclonal populations of B cells in a polyclonal background of reactive B lymphocytes. With this approach we found monoclonality in 4 of 18 cases of Hashimotos disease. In our opinion, these 4 cases demonstrate clearly the transition from autoimmune disease into non-Hodgkins lymphoma.

B-Lymphocytes↗
PubMed1993

Multistrain outbreak of chancroid in San Francisco, 1989-1991.

Restriction fragment length polymorphism (RFLP) and plasmid analyses were used to evaluate an outbreak of Haemophilus ducreyi in San Francisco. Fifty-four cases of culture-confirmed chancroid occurred between May 1989 and May 1991. Of these, 46 (96%) were in men and 35 (65%) were in blacks; the median age of patients was 34 years. Among the 32 isolates submitted for RFLP and plasmid analyses, six different HindIII RFLP patterns were identified. Two RFLP types were found in patients who had recently traveled to Los Angeles, Korea, or El Salvador. Four RFLP types appeared to be acquired locally and were more common among blacks (P = .002), in patients with a history of a sexually transmitted disease (P = .01), and in those who used drugs or exchanged drugs or money for sex (P = .08). The use of RFLP analysis confirmed that this outbreak was associated with multiple strains of H. ducreyi and allowed for the identification of risk factors for locally acquired chancroid.

Adolescent↗