Ocular manifestations of disseminated Mycobacterium chimaera infection after cardiothoracic surgery.

Objective: To describe the ocular manifestations of disseminated Mycobacterium chimaera infection after cardiothoracic surgery.

Design: Retrospective, observational case series.

Participants: Patients with disseminated M.

Electron microscopy and hydrodynamic properties of factor XIII subunits.

Factor XIII is a transglutaminase important in blood coagulation and fibrinolysis. Its function is to catalyze peptide bond formation between the gamma-carboxamide group of glutamines in one protein and the epsilon-amino group of lysine in another. There are two zymogenic forms of factor XIII: one is a noncovalent, intracellular dimer (A2); the other is a noncovalent, extracellular tetramer (A2B2).

Structure of human platelet membrane glycoproteins IIb and IIIa as determined by electron microscopy.

The glycoprotein (GP) IIb-IIIa complex was isolated from human platelet membranes and examined for glycoprotein stoichiometry and morphology. To determine the ratio of glycoproteins in the complex, the isolated glycoproteins were solubilized with sodium dodecyl sulfate and separated by high-performance liquid chromatography. Quantitative amino acid analysis of individual glycoproteins showed that the ratio of GP IIb to GP IIIa in the Ca2+-dependent complex was 0.

Fibronectin in extended and compact conformations. Electron microscopy and sedimentation analysis.

We have studied the ionic strength-dependent change in conformation of fibronectin, half-molecules of fibronectin produced by reduction and carboxyamidomethylation, and proteolytic fragments. In zone sedimentation through glycerol gradients, intact fibronectin sedimented at 13.5 and 10 S in 0.

Hereditary dysfibrinogenemia in a patient with thrombotic disease.

A new case of congenital dysfibrinogenemia, in which the patient has severe thrombotic disease, is reported. The abnormal fibrinogen molecules are characterized by normal fibrinopeptide release with thrombin and defective polymerization in the formation of fibrin. Clotting times with ancrod and reptilase are significantly prolonged.

High resolution electrophoretic analysis of human fibrinogen and its crosslinked intermediates.

Heterogeneity in human fibrinogen was examined using an improved two-dimensional isoelectric focusing-SDS polyacrylamide gel electrophoretic procedure. Four different preparations of fibrinogen were compared: single donor fibrinogen prepared from plasma by precipitation with ammonium sulfate or by affinity chromatography on fibrin-monomer Sepharose, fraction 1-4 prepared from Cohn fraction I paste, and Kabi grade L. The subunit A alpha, B beta, and gamma chains in all preparations had marked charge heterogeneity.

Fibrinogen Chapel Hill II: defective in reactions with thrombin, factor XIIIa and plasmin.

Fibrinogen Chapel Hill II is a hereditary, abnormal fibrinogen which is characterized by poor substrate reactivity toward thrombin, factor XIIIa and plasmin. The patient has a low plasma level of clottable protein with normal antigen concentration, high amounts of fibrinogen related material in serum, and prolonged thrombin and reptilase clotting times. Fibrinopeptide release was decreased with both thrombin and ancrod, indicating that release of fibrinopeptide A from the abnormal fibrinogen was impaired.

Fibronectin molecule visualized in electron microscopy: a long, thin, flexible strand.

We have determined the structure of plasma fibronectin by electron microscopy of shadowed specimens. the 440,000 molecular weight, dimeric molecule appears to be a long, thin, highly flexible strand. The contour length of the most extended molecules is 160 nm, but a distribution of lengths down to 120 nm was observed, indicating flexibility in extension as well as in bending.

A naturally occurring antibody that inhibits fibrin polymerization.

A 13-year-old girl with chronic aggressive hepatitis, postnecrotic cirrhosis, ulcerative colitis, and a coagulation defect acquired an antibody that specifically interfered with fibrin formation. We sought to characterize the antibody and determine the mechanism of its inhibitory activity. The patient's purified fibrinogen was functionally normal; however, the antibody inhibited the self-assembly of fibrin and prolonged the clotting times of the patient's plasma.

Fibrinogen Chapel Hill: hypodysfibrinogenemia with a tertiary polymerization defect.

A patient with a functionally defective fibrinogen (fibrinogen Chapel Hill) has been investigated. Fibrinogen Chapel Hill is characterized by hypofibrinogenemia, with a plasma concentration about one third of normal, as measured both functionally and immunochemically. Fibrinogen survival is normal; so also is fibrinopeptide release.