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Biomedical subjects

D Relman

Publications and source records attributed to D Relman.

6 recordsLinked to original sources
PubMed2001

Whipple's disease and Tropheryma whippelii: secrets slowly revealed.

Whipple's disease was described in 1907 and was designated "intestinal lipodystrophy," despite the detection of bacteria in 1 specimen. This finding was later substantiated by the success of antibiotic therapy, which resulted in dramatic clinical responses, and by use of electron microscopy, which detected monomorphic bacilli in affected tissues. Many attempts at culture failed, and these bacteria were characterized as actinomycetes for the first time by means of broad-range 16S rDNA amplification and molecular phylogenetic methods. The name "Tropheryma whippelii" was proposed for this bacterium. Whipple's disease is a systemic disease that affects many organ systems, producing protean manifestations. This article summarizes recent developments with regard to this topic as well as unanswered questions regarding the pathogenesis and acquisition of infection, the biology and ecology of the organism, the clinical spectrum of disease, diagnosis of the disease, and therapy.

Actinobacteria↗
PubMed1998

Diagnostic utility of the polymerase chain reaction in 2 cases of suspected Whipple disease.

We describe 2 patients with a diagnosis of Whipple disease in whom the usual antibiotic therapy failed. A polymerase chain reaction-based test was used to identify the recently described Whipple bacillus, Tropheryma whippelii. In one case, the diagnosis was confirmed, whereas in the second case, which had been histologically diagnosed as Whipple disease of the brain, the process was identified as a monocyte-derived histiocytosis. In conclusion, Whipple disease can be distinguished from other diseases with similar histological features with the use of a polymerase chain reaction-based test.

Actinobacteria↗
PubMed1990

Recognition of a bacterial adhesion by an integrin: macrophage CR3 (alpha M beta 2, CD11b/CD18) binds filamentous hemagglutinin of Bordetella pertussis.

During the course of whooping cough, Bordetella pertussis interacts with alveolar macrophages and other leukocytes on the respiratory epithelium. We report here mechanisms by which these bacteria adhere to human macrophages in vitro. Whole bacteria adhere by means of two proteins, filamentous hemagglutinin (FHA) and pertussis toxin, either of which is sufficient to mediate adherence. FHA interacts with two classes of molecules on macrophages, galactose-containing glycoconjugates and the integrin CR3 (alpha M beta 2, CD11b/CD18). The interaction between CR3 and FHA involves recognition of the Arg-Gly-Asp (RGD) sequence at positions 1097-1099 in FHA. This study demonstrates that bacterial adherence can be based on the interaction of a bacterial adhesin RGD sequence with an integrin and that bacterial adhesins can have multiple binding sites characteristic of eukaryotic extracellular matrix proteins.

Amino Acid Sequence↗
PubMed1990

Genetic characterization of Bordetella pertussis filamentous haemagglutinin: a protein processed from an unusually large precursor.

The nucleotide sequence of the structural gene for filamentous haemagglutinin (FHA), fhaB, a crucial adherence factor for Bordetella pertussis, has been determined. Its 10774 nucleotides are far more than necessary to encode the 220 kD biologically active, mature polypeptide product, suggesting a role for co- or post-translational processing. Fusion proteins derived from various portions of the fhaB open reading frame (ORF) were used to generate polyclonal antisera. Western immunoblot analysis of purified FHA and Bordetella sp. whole cell extracts with these antisera indicated that the 220 kD product is encoded by the 5' portion of the ORF and that the smaller polypeptide species are breakdown products of this polypeptide. These data, as well as N-terminal amino acid sequencing of the major polypeptide species, suggest a scheme for the proteolytic processing of an FHA precursor polypeptide.

Adhesins, Bacterial↗