PubMed Health⌕ Search

Biomedical subjects

M L Hart

Publications and source records attributed to M L Hart.

10 recordsLinked to original sources
PubMed2002

Osteopetrosis, femoral fracture, and chronic osteomyelitis caused by Staphylococcus aureus small colony variants (SCV) treated by girdlestone resection--6-year follow-up.

Chronic osteomyelitis caused by Staphylococcus aureus small colony variants in combination with osteopetrosis is a unique combination of disorders that confronted us with major challenges. The therapeutic approach included four serial debridements and antimicrobial therapy. The aggressive treatment led to an instability of the brittle and hard osteopetrotic bone, and after 11 weeks, a fracture of the femoral neck occurred. A salvage procedure of the femur was performed, and the cultures obtained during this intervention remained negative. At a 6-year follow-up, the girdlestone situation still showed an acceptable functional outcome without any recurrence of osteomyelitis.

Adult↗
PubMed2001

Deterministic dynamics in the minority game.

The minority game (MG) behaves as a stochastically disturbed deterministic system due to the coin toss invoked to resolve tied strategies. Averaging over this stochasticity yields a description of the MG's deterministic dynamics via mapping equations for the strategy score and global information. The strategy-score map contains both restoring-force and bias terms, whose magnitudes depend on the game's quenched disorder. Approximate analytical expressions are obtained and the effect of "market impact" is discussed. The global-information map represents a trajectory on a de Bruijn graph. For small quenched disorder, a Eulerian trail represents a stable attractor. It is shown analytically how antipersistence arises. The response to perturbations and different initial conditions is also discussed.

Journal Article↗
PubMed2001

MHCII, Tlr4 and Nramp1 genes control host pulmonary resistance against the opportunistic bacterium Pasteurella pneumotropica.

MHCII, Tlr4, and Nramp1 genes are each independently important in pulmonary immunity. To determine the effect of these genes on host resistance, mice carrying various combinations of functional alleles for these three genes were experimentally challenged with the opportunistic bacterium, Pasteurella pneumotropica. MHCII-/-, Tlr4d/d, and Nramp1s/s mice were significantly more susceptible to experimental infections by P. pneumotropica after intranasal challenge compared to mice carrying functional alleles at only one of those genes. P. pneumotropica were cultured from the lungs of challenged mice, and the severity of the pneumonia strongly correlated with the number of isolated bacteria. Mice with the genotype MHCII-/- Tlr4n/n genotype were less susceptible to pneumonia than MHCII+/+, Tlr4d/d mice. It is interesting that the Nramp1 gene contribution to host resistance was apparent only in the absence of functional MHCII or Tlr4 genes. These data suggest that MHCII, Tlr4, and Nramp1 genes are important to pulmonary bacterial resistance.

Alleles↗
PubMed2000

Interaction of mannose-binding lectin with primary isolates of human immunodeficiency virus type 1.

Mannose-binding lectin (MBL) is present in human serum and plays an important role in innate immunity by binding to carbohydrate on micro-organisms. Whereas the gp120/gp41 of human immunodeficiency virus type 1 (HIV-1) contains numerous N-linked glycosylation sites and many of these sites contain high-mannose glycans which could interact with MBL, the interaction between MBL and primary isolates (PI) of HIV-1 has not been studied. To determine if PI of HIV bind to MBL, a virus capture assay was developed in which virus was incubated in MBL-coated microtitre wells followed by detection of bound virus with an ELISA for p24 antigen. The X4 HIV-1(MN) T cell line-adapted strain and PI of HIV (R5 and X4) bound to MBL. Binding of virus to MBL was via the carbohydrate-recognition domain of MBL since binding did not occur in the absence of Ca(2+) and was blocked by preincubation of MBL-coated wells with soluble mannan. The interaction of virus with MBL-coated wells was also inhibited by preincubation of virus with soluble MBL, indicating that both immobilized and soluble forms of MBL bound to HIV. Although host cell glycoproteins are incorporated into the membrane of HIV, binding of virus to immobilized MBL required expression of gp120/gp41 on virus particles, suggesting the presence of either an unusually high carbohydrate density and/or a unique carbohydrate structure on gp120/gp41 that is the target of MBL. This study shows that PI of HIV bind to MBL and suggests that MBL can selectively interact with HIV in vivo via carbohydrate structures on gp120/gp41.

Acquired Immunodeficiency Syndrome↗
PubMed1977

The biosynthesis of elastin by an aortic medial cell culture.

A long term culture of aortic medial cells, derived from newborn pig aorta, has been established. The ability of these cells to synthesize soluble elastin has been demonstrated by isolation and characterization of the radioactively labeled protein, using soluble elastin of copper-deficient pig aorta as the carrier. The synthesis of corsslinked elastin was shown by the isolation and identification of the lysine-derived crosslinks after incubating the cultures with [14C]-labeled lysine. The precursor relationship of soluble to insoluble elastin was demonstrated by incubating the [3H]-labeled soluble elastin from copper-deficient pig aorta with the culture and isolating labeled crosslinks from the insoluble elastin residue.

Aorta↗