Use of cloned DNA methylase genes to increase the frequency of transfer of foreign genes into Xanthomonas campestris pv. malvacearum.

In vitro-packaged cosmid libraries of DNA from the bacterium Xanthomonas campestris pv. malvacearum were restricted 200- to 1,000-fold when introduced into Mcr+ strains of Escherichia coli compared with restriction in the Mcr- strain HB101. Restriction was predominantly associated with the mcrBC+ gene in E.

Platelet and fibrin modification by radiographic contrast media.

The effect of the radiographic contrast agents, iopamidol and diatrizoate, on fibrin assembly and structure as well as platelet surface charge was studied. Increasing the iopamidol concentration from 0 to 4.5 mM prolongs the fibrin gelation time from 20 to 105 seconds (an anticoagulant effect) and reduces the fibrin fiber mass/length ratio from 3.

Thrombotic and cardiovascular complications related to nonionic contrast media during cardiac catheterization: analysis of 8,517 patients.

The incidence of major complications associated with nonionic contrast media has not been defined in a large study. Accordingly, cardiovascular complications, especially thrombotic events, were prospectively evaluated in 8,517 consecutive patients undergoing diagnostic cardiac catheterization with either iopamidol (n = 6,293) or iohexol (n = 2,224). Thrombotic events were defined as coronary embolus, coronary occlusion, transient ischemic attack or stroke occurring at the time of catheterization.

Small, stable shuttle vectors for use in Xanthomonas.

Plasmids from three broad-host-range (bhr) incompatibility groups (Inc) were evaluated for use as cloning vectors in Xanthomonas campestris pv. malvacearum (Xcm), the causal agent of bacterial blight of cotton. The IncP vectors pLAFR3 and pVK102 could not be introduced into Xcm at a significant frequency (less than 1 x 10(-10] and IncQ vectors such as pKT210 were unstable in their maintenance and tended to delete cloned inserts.

Calcium destabilizes and causes conformational changes in hyaluronic acid.

The physical properties of proteoglycans found in the extracellular matrix influence the behavior of resident macromolecules, micro-ions, and cells. The forces stabilizing structured regions of hyaluronic acid (HA), a major component of extracellular matrix, were measured. The free energy of stability associated with structured regions within human HA was determined by potentiometric titration.

The clinical manifestations of Degos' syndrome.

Pathologic mechanisms underlying Degos' syndrome are poorly characterized. Thrombosis, either as a consequence of a postulated vasculitis or as a primary defect, is often a clinical complication of this syndrome. We have studied multiple coagulation parameters, including potential defects in fibrin assembly and other adhesive proteins, in a patient with Degos' syndrome and found no specific abnormality to explain the pathologic features of this syndrome.

Effect of homo poly(L-amino acids) on fibrin assembly: role of charge and molecular weight.

Positively charged molecules such as protamine, leukocyte cationic protein, and the carboxyl terminus of platelet factor 4 have been shown to increase fibrin fiber thickness. Synthetic homo poly(L-amino acids) were used to explore the role of charge and molecular weight of cationic molecules on fibrin assembly. The effects of poly(L-lysine) (PLL), poly(L-glutamic acid) (PLG), poly(L-aspartic acid) (PLA), poly(L-histidine) (PLH), and poly(L-arginine) (PLArg) on the assembly and structure of fibrin gels were studied by using light-scattering techniques.

Influence of the subendothelial basement membrane components on fibrin assembly. Evidence for a fibrin binding site on type IV collagen.

Effective repair of a vascular injury depends on establishment of a stable fibrin patch at the injury site. Data presented in this study demonstrate that structural modification of fibrin occurs as a result of fibrin interaction with naturally occurring components of the vascular basement membrane and subendothelial structures. Of the basement membrane components, type IV collagen produces the greatest structural modification, generating thick fibrin fibers; a 3-fold increase in the fiber mass/length ratio occurs when type IV collagen is increased from 0 to 100 ng/ml.

Nonsecretory multiple myeloma.

A diagnosis of nonsecretory multiple myeloma, based on multiple bony lytic lesions seen on roentgenographic studies and sheets of plasma cells seen in the bone marrow, was established in two patients with severe back pain. No paraprotein was detected in the serum or concentrated urine of the patients. Immunofluorescent staining of the bone marrow demonstrated the presence of intracytoplasmic J chains in the patients' plasma cells.

The use of high-dose intravenous gamma-globulin in acquired von Willebrand syndrome.

Acquired von Willebrand syndrome has been reported in patients with a variety of primary diseases, many immunologic in nature. Usually, an autoantibody to von Willebrand factor can be identified. These patients often experience severe hemorrhages requiring large doses of cryoprecipitate or factor VIII concentrates, thus exposing them to viral and allergic complications.

Desensitisation of human platelets against stimulation by thromboxane mimics--reduction in receptor capacity and loss of functional response.

Number and affinity of thromboxane A2/PGH2 receptors on gel-filtered human platelets was determined using the receptor antagonist 3H-SQ 29548 as a tracer compound. Preincubation of platelet rich plasma (PRP) with U 46619 reduced receptor number to 31% of control platelets without affecting the affinity (2 x 10(-9) mol/l). Pretreated platelets lost their reactivity to stimulation by U 46619 but not to thrombin within 3 h.

Influence of factor XIII and fibronectin on fiber size and density in thrombin-induced fibrin gels.

The possible role of fibronectin as a molecular anchor for fibrin to ground substance, the ability of factor XIII to cross-link fibronectin to fibrin, and the demonstrated differences between purified fibrin and fibrin formed in plasma prompted this study of the effect of both proteins on fibrin assembly and structure. The influences of activated factor XIII (FXIIIa) and fibronectin were studied by use of turbidity techniques. Fibronectin over a concentration range of 0 to 800 micrograms/ml produced no change in either the mass-length ratio or density of fibrin fibers in 1 mg/ml fibrin gels.

Spontaneous antithrombin in a patient with benign paraprotein.

A 66-year-old man with peptic ulcer disease developed a paraprotein that resulted in a spontaneously prolonged prothrombin time, activated partial thromboplastin time, and thrombin clotting time. Although the reptilase time was normal, the thrombin clotting time failed to correct with the addition of normal plasma, calcium, or protamine sulfate. The patient's purified fibrinogen was normal, but his serum contained an IgG that inhibited the clotting of normal plasma and purified fibrinogen in the presence of thrombin.

Platelet factor 4 enhances fibrin fiber polymerization.

In order to further examine the role of platelet secretory products on fibrin assembly, we have examined the effects of purified platelet factor 4 (PF4) on fibrin formation in vitro. The kinetics of fibrin formation and the structural properties of the resulting fibrin gel are strongly affected by PF4. In the presence of 7.

Influence of Ca2+ on the structure of reptilase-derived and thrombin-derived fibrin gels.

The effects of Ca2+ ion on the structure of thrombin-derived and reptilase-derived fibrin gels formed at various ionic strengths were studied turbidimetrically. For both enzymes clotting times were shorter, final gel turbidities were higher and fibre mass/length ratios were increased as the ionic strength was lowered. The addition of 5 mM-Ca2+ augmented each of these effects for any given ionic strength.

Gene-for-gene interactions of five cloned avirulence genes from Xanthomonas campestris pv. malvacearum with specific resistance genes in cotton.

A total DNA clone bank of a strain of Xanthomonas campestris pv. malvacearum (Xcm) was constructed in the cosmid vector pSa747 and transfected into Escherichia coli. The Xcm strain carries at least nine identifiable avirulence (A) genes.

Oophoropexy and the management of Hodgkin's disease. A reevaluation of the risks and benefits.

Female patients with Hodgkin's disease who undergo staging laparotomy frequently have oophoropexy performed to preserve both fertility and hormone production. Because of recent changes in therapy favoring systemic chemotherapy rather than total nodal irradiation for patients with stage III Hodgkin's disease, the need for oophoropexy may be less than previously described. Thirty-nine women of childbearing age underwent laparotomy at the University of North Carolina, Chapel Hill, from 1970 to 1984.

[Pretherapeutic testing of sensitivity to cytostatic drugs in primary cultures of selected urologic tumors].

In 30 patients with malignant urologic tumours (scrotal tumours, renal tumours, tumours of the urinary bladder) an in vitro cultivation of the primary tumor was tried. According to the technique of Tannenberger and Bacigalupo 21 primary cell cultures could be applied. This corresponds to an accession rate of 70%.

Gradual dinosaur extinction and simultaneous ungulate radiation in the hell creek formation.

Dinosaur extinction in Montana, Alberta, and Wyoming was a gradual process that began 7 million years before the end of the Cretaceous and accelerated rapidly in the final 0.3 million years of the Cretaceous, during the interval of apparent competition from rapidly evolving immigrating ungulates. This interval involves rapid reduction in both diversity and population density of dinosaurs.

Hyperfibrinogenemia as a cause of prolonged thrombin clotting time.

Recognized causes of a prolonged thrombin clotting time (TCT) include a decreased plasma fibrinogen level, dysfibrinogenemia, paraproteinemia, heparin contamination, elevated levels of fibrin degradation products, and liver failure. We have frequently seen patients with an isolated prolonged TCT in the absence of any of these conditions and without obvious clinical impact. During a previous evaluation of hyperfibrinogenemia, we noted a surprisingly high incidence of prolonged TCT, prompting this evaluation of hyperfibrinogenemia as a possible cause.

Granulocyte lysosomal cationic protein alters fibrin assembly: a possible mechanism for granulocyte control of clot structure.

The effect of highly positively charged molecules on the assembly and structure of thrombin-induced fibrin gels was studied with turbidity techniques. Lysosomal cationic proteins (LCP) extracted from rabbit heterophils produced enhanced lateral association of fibrin fibers. A crude extract of LCP had little effect on kinetics but produced an increase in the final fiber mass/length ratios.

Viscous factors in peripheral tissue perfusion.

To ascertain the relative importance of the factors that influence blood viscosity (VIS), we measured hematocrit (HCT), filterability index, fibrinogen level (FIB), and Ektacytometer indices at osmolarities of both 290 (EI 290) and 200 (EI 200) in 21 diabetic patients with peripheral vascular disease (DPVDs) and 11 healthy volunteers (HVs). Stepwise multiple regression analyses generated a formula based on three of the independent variables (FIB, HCT, EI 200) that accurately predicted VIS (r = 0.79, p less than 0.

Tracer diffusion coefficients of proteins by means of holographic relaxation spectroscopy: application to bovine serum albumin.

Holographic relaxation spectroscopy has been used to measure tracer diffusion coefficients for photochromically labeled bovine serum albumin in solutions having total bovine serum albumin concentrations in the range 3.25 to 257 g/liter. In the limit of zero concentration, the diffusion coefficient (20 degrees C, 0.