Enhanced radioresponse of paclitaxel-sensitive and -resistant tumours in vivo

Functional assembly of the plasminogen-dependent proteolytic system on the cell surface requires multiple interactions involving urokinase (uPA), urokinase receptor (uPAR), plasminogen activator inhibitors, and other molecules that mediate cell migration and adhesion. We analyzed the in vitro interaction of uPAR-containing particulate cell fractions with the amino-terminal fragment (ATF) of human urokinase and the matrix-like form of vitronectin. Binding and cross-linking of 125I-labeled ATF to crude membrane extracts from LB6-19 mouse cells overexpressing human uPARs in the presence of 25 nM urea-denatured vitronectin led to the formation of Mr 137,000, 92, 000, and 82,000 covalent complexes. Immunoprecipitation of the preformed cross-linked 125I-labeled complexes with anti-vitronectin, anti-uPA, or anti-uPAR antibodies revealed that the Mr 82,000 and 92, 000 species do contain ATF and vitronectin and identified the Mr 137, 000 species as a ternary complex formed by ATF, uPAR, and vitronectin. A similar electrophoretic pattern was displayed by acid-pretreated membranes extracted from MCF-7 breast carcinoma or HT1080 fibrosarcoma cell lines, as well as a ductal breast carcinoma specimen; the latter exhibited complex formation at concentrations of vitronectin lower than 10 nM. Finally, uPAR-vitronectin interaction was further documented by the decreased reactivity of an anti-uPAR polyclonal antibody to acid-pretreated sections of 10 breast carcinomas that had been preincubated with vitronectin. Our findings highlight the ability of uPAR to interact simultaneously with vitronectin and uPA in breast cancer, supporting a dynamic coupling of the molecular mechanisms underlying plasminogen-dependent matrix degradation and cell adhesion.     

On the transport of a suspended particle in flow through the entrance region of a tube

The motion of a single, spherical particle, released at different radial positions at the inlet of the entrance region of a straight circular laminar flow tube (Re = 260), was studied theoretically. Radial migration of the particle, either toward the tube center or toward the tube wall, was predicted. Based on the hypothesis that the particle experienced a lift force which was produced by the vorticity in the boundary layer and a velocity difference between the center of the suspended particle and the fluid medium, an inertia-vorticity fluid dynamic model was formulated to analyze the particle radial motions. Computational flow dynamics (CFD) solutions obtained from a 9.8 mm diameter tube model included the resulting particle loci for three particle radii (a = 0.1 cm, 0.085 cm, 0.050 cm), with the particle entry at various radial positions. The computation also covered a range of different particle entry speeds. The results showed that the particle migrates toward the tube center if it lags behind the medium in the core region; otherwise, it migrates toward the tube wall. Additional flow experiments were conducted in a circular (2R = 10.2 mm), 300 mm long straight tube. A small polystyrene sphere (2a = 1.72 mm, density rho p = 1.014 g.cm-3) was released at the inlet (X = 0, eta/R = 0.48) with two dimesionless release velocities (omega p = 0, and omega p > 1.0). The recorded particle traces agree well with the computational model.     

Co-trimoxazole in prevention of bacteriuria after prostatectomy

In a prospective, double-blind trial prophylactic cotrimoxazole produced a highly significant reduction in the incidence of bacteriuria after prostatectomy. Only two out of 38 patients who received the drug developed bacteriuria compared with 19 out of 36 patients on placebo. Klebsiella-Enterobacter spp and coagulase-negative staphylococci were responsible for most infections. Although co-trimoxazole prophylaxis is obviously effective, widespread use might increase the incidence of bacterial resistance.     

Approaches to lung cancer treatment using the CD3 x EGP-2-directed bispecific monoclonal antibody BIS-1

OBJECTIVES: To evaluate the clinical importance of the interaction between carbamazepine (CBZ) and dextropropoxyphene in elderly patients. METHODS: All patients (n = 7263) in Gothenburg, Sweden, who were part of a drug-dispensing programme, were included in the study. Eight per cent of the patients took CBZ and 18% took dextropropoxyphene, continuously. Patients who used a combination of these drugs were compared with patients who took only CBZ or dextropropoxyphene or neither of the two drugs. These four groups of patients were matched to each other with reference to gender, age and concomitant medication, which finally resulted in 21 patients in each group. A questionnaire with 30 symptoms of well-being, including symptoms typical of adverse effects of CBZ, were answered by the patients with the help of a registered nurse. Venous blood samples were drawn from the patients for the analysis of CBZ, its metabolite CBZ 10,11-epoxide (CBZ-E) and dextropropoxyphene. RESULTS: The doses of CBZ and dextropropoxyphene were lower among patients who used the combination of the two drugs than among those who only used one of the drugs. The mean level of CBZ in serum (S-CBZ) was, however, significantly higher and the level of CBZ-E in serum (S-CBZ-E) significantly lower among the patients who used the combination of CBZ and dextropropoxyphene, thus indicating an inhibition of the metabolism of CBZ. The prevalence of symptoms indicating side effects of CBZ was significantly higher in the group of patients who used both drugs. CONCLUSION: This study has shown that the combination of CBZ and dextropropoxyphene is hazardous in elderly patients and should be used with caution.     

Adrenergic beta 1- and beta 1 + 2-receptor blockade suppress the natural killer cell response to head-up tilt in humans

To evaluate stress-induced changes in blood leukocytes with emphasis on the natural killer (NK) cells, eight male volunteers were followed during three trials of head-up tilt with adrenergic beta 1- (metoprolol) and beta 1 + 2- (propranolol) blockade and with saline (control) infusions. The beta 1- and beta 1 + 2-receptor blockade did not affect the appearance of presyncopal symptoms, but the head-up tilt induced a transient lymphocytosis that was abolished by beta 1 + 2-receptor blockade but not by beta 1-receptor blockade. Head-up tilt also resulted in delayed neutrophilia, which was insensitive to beta-receptor blockade. Lymphocyte subset analysis revealed that the head-up tilt resulted in a twofold increase in the percentage and absolute number of CD3-/CD16+ and CD3-/CD56+ NK cells in peripheral blood and that this increase was partially blocked by metoprolol and abolished by propranolol. The NK cell activity on a per NK cell basis did not change during head-up tilt, indicating that the cytotoxic capability of NK cells recruited to circulation is unchanged. The data suggest that the head-up tilt-induced lymphocytosis was due mainly to CD16+ and CD56+ NK cells and that their recruitment to the blood was inhibited by beta 1- and especially beta 1 + 2-receptor blockade. Thus stress-induced recruitment of lymphocytes, and of NK cells in particular, is mediated by epinephrine through activation of beta-receptors on the lymphocytes.     

A distinct form of spondyloepimetaphyseal dysplasia with multiple dislocations

Three unrelated patients with identical radiological features are presented. Hypotonia was noted at birth and one patient was diagnosed as having congenital fibre type disproportion in the neonatal period. Later muscle biopsies, however, were entirely normal. All patients, now in their teens and twenties, are of normal intelligence, show striking epiphyseal and metaphyseal changes of the long bones, and have joint laxity and multiple dislocations of large joints, which are particularly incapacitating at the knees. These three cases represent a sporadic, previously unreported skeletal dysplasia with spondyloepimetaphyseal distribution and multiple large joint dislocations.     

The application of radionuclide infarct scintigraphy to diagnose perioperative myocardial infarction following revascularization

To evaluate the application of radionuclide infarct scintigraphy to diagnose myocardial infarction after revascularization, we obtained postoperative technetium 99m pyrophosphate myocardial scintigrams, serial electrocardiograms and CPK-MB isoenzymes in ten control and 51 revascularized patients. All control patients had negative electrocardiograms and scintigrams, but eight had positive isoenzymes. Eight revascularized patients had positive electrocardiograms, images and enzymes and two had positive scintigrams and enzymes with negative electrocardiograms. Thirty-four patients with negative electorcardiograms and scintigrams had positive isoenzymes; in only seven patients were all tests negative. Our data suggest radionuclide infarct scintigraphy is a useful adjunct to the electrocardiogram in diagnosing perioperative infarction. The frequent presence of CPK-MB in postoperative patients without other evidence of infarction suggests that further studies are required to identify all factors responsible for its release.     

Double-blind, placebo-controlled study of the effects of carvedilol in patients with moderate to severe heart failure. The PRECISE Trial. Prospective Randomized Evaluation of Carvedilol on Symptoms and Exercise

BACKGROUND: Carvedilol has improved the symptomatic status of patients with moderate to severe heart failure in single-center studies, but its clinical effects have not been evaluated in large, multicenter trials. METHODS AND RESULTS: We enrolled 278 patients with moderate to severe heart failure (6-minute walk distance, 150 to 450 m) and a left ventricular ejection fraction < or = 0.35 at 31 centers. After an open-label, run-in period, each patient was randomly assigned (double-blind) to either placebo (n = 145) or carvedilol (n = 133; target dose, 25 to 50 mg BID) for 6 months, while background therapy with digoxin, diuretics, and an ACE inhibitor remained constant. Compared with placebo, patients in the carvedilol group had a greater frequency of symptomatic improvement and lower risk of clinical deterioration, as evaluated by changes in the NYHA functional class (P = .014) or by a global assessment of progress judged either by the patient (P = .002) or by the physician (P < .001). In addition, treatment with carvedilol was associated with a significant increase in ejection fraction (P < .001) and a significant decrease in the combined risk of morbidity and mortality (P = .029). In contrast, carvedilol therapy had little effect on indirect measures of patient benefit, including changes in exercise tolerance or quality-of-life scores. The effects of the drug were similar in patients with ischemic heart disease or idiopathic dilated cardiomyopathy as the cause of heart failure. CONCLUSIONS: These findings indicate that, in addition to its favorable effects on survival, carvedilol produces important clinical benefits in patients with moderate to severe heart failure treated with digoxin, diuretics, and an ACE inhibitor.     

The structural basis for pseudoreversion of the H95N lesion by the secondary S96P mutation in triosephosphate isomerase

The structural basis for the 3000-fold decrease in catalytic efficiency of the H95N mutant chicken triosephosphate isomerase and the 60-fold regain of catalytic efficiency in the double mutant, H95N.S96P, have been analyzed. The results from a combination of X-ray crystallography and Fourier transform infrared spectroscopy experiments indicate that the predominant defect in the H95N mutant isomerase appears to be its inability to bind the substrate in a coplanar, cis conformation. The structures of each mutant isomerase were determined from X-ray crystallography of the complex of phosphoglycolohydroxamate (PGH), an intermediate analog with the isomerase, and each was solved to a resolution of 1.9 A. The PGH appeared to be in two different conformations in which the enediol-mimicking atoms, O2-N2-C1-O1, of the PGH were not coplanar. No density was observed that would correspond to the coplanar conformation. Two bands are observed for the dihydroxyacetone phosphate carbonyl in the H95N mutant FTIR spectrum, and these can be explained if the O1 of DHAP, like the O1 of PGH in the crystal structure, is in two different positions. Two ordered water molecules are located between O1 of PGH and N delta of N95. Comparison of the structure of the pseudorevertant, H95N.S96P with that for the H95N single mutant, shows that S96P mutation causes the double mutant to regain the ability to bind PGH predominantly in the coplanar, cis conformation. Electron density for a single ordered water molecule bridging the N95 amide side chain and the O2 of PGH is observed, but the density was weak, perhaps indicating that the water molecule is somewhat disordered. Whether or not a water molecule is hydrogen bonded to O2 of PGH may explain the two carbonyl stretching frequencies observed for the GAP carbonyl. Together, the crystal structures and the FTIR data allow a complete explanation of the catalytic properties of these two mutant isomerases.