Successful strategy for the selection of new strawberry-associated rhizobacteria antagonistic to Verticillium wilt

In order to isolate and characterize new strawberry-associated bacteria antagonistic to the soil-borne pathogenic fungus Verticillium dahliae Kleb., rhizobacterial populations from two different strawberry species, Greenish Strawberry (Fragaria viridis) and Garden Strawberry (F. x ananassa) obtained after plating onto King's B and glycerol-arginine agar, were screened for in vitro antagonism toward V. dahliae. The proportion of isolates with antifungal activity determined in in vitro assay against V. dahliae was higher for the Garden Strawberry than for the Greenish Strawberry. From 300 isolates, 20 isolates with strong antifungal activity were selected characterized by physiological profiling and molecular fingerprinting methods. Diversity among the isolates was characterized with molecular fingerprints using amplified ribosomal DNA restriction analysis (ARDRA) and the more discriminating BOX-PCR fingerprint method. The physiological profiles were well correlated with molecular fingerprinting pattern analysis. Significant reduction of Verticillium wilt by bacterial dipping bath treatment was shown in the greenhouse and in fields naturally infested by V. dahliae. The relative increase of yield ranged from 117% (Streptomyces albidoflavus S1) to 344% (Pseudomonas fluorescens P10) in greenhouse trials, and 113% (Streptomyces albidoflavus S1) to 247% (Pseudomonas fluorescens P6) in field trials. Evaluation resulted in the selection of three effective biocontrol agents (Pseudomonas fluorescens P6, P10, and Streptomyces diastatochromogenes S9) antagonistic to the Verticillium wilt pathogen.

Characterization of alpha2-adrenoceptor subtypes in pregnant human myometrium

The aim of the present investigation was to determine which subtypes of the alpha2-adrenoceptors are being expressed in the human pregnant myometrium at term pregnancy. In radioligand binding studies, the specific binding of [3H]rauwolscine to human myometrial membranes was specific and of high affinity with Kd of 2.8 +/- 0.6 nMand Bmax of 95 +/- 5 fmol/mg protein. Results from competition for the binding of [3H]rauwolscine using subtype-selective ligands, oxymetazoline (alpha2A-subptype), chlorpromazine (alpha2B-subtype) and prazosin (alpha2B-alpha2C-subtype), suggested that the alpha2A- and alpha2B-subtypes are being co-expressed. In order to examine if also the alpha2C-subtype is being expressed we used an optimal concentration of oxymetazoline or chlorpromazine which would block the high-affinity site, equivalent to the alpha2A- and alpha2B-subtype respectively. Competition curves of both oxymetazoline and chlorpromazine still showed a significantly better fit using a two-site model, suggesting that the alpha2C-subtype also is being expressed. The expression of alpha2C-subtype mRNA was confirmed using reverse transcription-polymerase chain reaction on mRNA isolated from myometrial biopsies. In conclusion, our results suggest that all three subtypes of alpha2-adrenoceptors are being coexpressed in the human myometrium at term pregnancy and that alpha2-expression is dominated by the alpha2A-subtype.

Genotypic and phenotypic differentiation of an antifungal biocontrol strain belonging to Bacillus subtilis

Physiological and molecular fingerprints of biotechnologically relevant rhizobacteria are necessary for registration, patenting, recognition and quality checking of the strains. To characterize the biological control agent, Bacillus subtilis B2g, the strain was compared with other plant-associated B. subtilis isolates. Phenotypic characterization included biochemical and nutritional properties, in vitro activity and analysis of potential antagonistic mechanisms towards several plant pathogenic fungi. According to the phenotypic characteristics, it was not possible to differentiate the biocontrol agent from the other strains, although the enzymatic fingerprint was unique. Genotypic diversity among the isolates was characterized by molecular fingerprinting methods using REP-PCR (repetitive extragenomic palindromic PCR), and macrorestriction of genomic DNA and electrophoretic separation of DNA fragments by pulsed-field gel electrophoresis (PFGE). A protocol for PFGE analysis using restriction enzyme SfiI for B. subtilis was developed. PFGE typing of B. subtilis B2g resulted in a unique fingerprint. Therefore, it was possible to differentiate B. subtilis B2g, the biocontrol agent of Phytovit, from other antifungal B. subtilis isolates.

Changes in beta(2)-adrenoceptor expression and in adenylyl cyclase and phosphodiesterase activity in human uterine leiomyomas

Uterine leiomyoma is a very common benign tumour with unclear pathophysiology in adult women. In the present study we have investigated the expression level of alpha(2)- and beta(2)-adrenoceptors, and the adenylyl cyclase and phosphodiesterase activity in leiomyoma tissue compared with adjacent myometrium. Our results show that the alpha(2)/beta(2)-adrenoceptor ratio is increased in leiomyoma, due to a significant decrease in beta(2)-adrenoceptor expression. These changes were not due to an increased innervation, as the tumour tissue was completely devoid of nerve fibres. Moreover, the adenylyl cyclase activity of leiomyoma membranes was found to be approximately 50% lower, whereas the phosphodiesterase activity was significantly increased (by approximately 100%). We found that stimulating an increase in intracellular cyclic AMP, by adenylyl cyclase activity through beta(2)-adrenoceptors (isoprenaline), by direct enzyme activation (forskolin), or by inhibition of phosphodiesterase activity (papaverine), potently blocked both protein and DNA synthesis in cultured leiomyoma smooth muscle cells. Our results imply the adrenoceptors might be involved in, or a consequence of, leiomyoma growth. The results also suggest a new interesting approach for leiomyoma pharmacotherapy.

Observation of hot-electron pressure in the vibration dynamics of metal nanoparticles

We investigate the vibration dynamics of ellipsoidal silver nanoparticles, using time-resolved optical pump-probe spectroscopy. When excited with femtosecond laser pulses, the particles execute anisotropic shape oscillations. We show that these vibrations are triggered by the thermal expansion of the optically heated particles. The time dependence of the vibrations indicates that this expansion is caused by two mechanisms: The lattice anharmonicity and the extremely large pressure of the hot conduction electrons.

Heparin-induced thrombocytopenia: a critical risk/benefit analysis of patients in intensive care treated with R-hirudin

Patients in intensive care may be at high risk of in vivo platelet activation because comorbid conditions, such as infections, septicemia, shock, disseminated intravascular coagulation, and cancer represent procoagulant states. Hyperreactivity of platelets with or without a decline of cell count may result in thromboembolic complications potentially associated with the phenomenon of heparin-induced thrombocytopenia. We analyzed the data of 10 patients highly suspected of having heparin-induced thrombocytopenia during their intensive care treatment of 29 plus or minus 22 days. In seven patients, thrombocytopenia coincided with thromboembolic complications. Six patients had additionally undergone fibrinolytic therapy before starting activated partial thromboplastin time-adapted alternative anticoagulation with r-hirudin. In three patients, the platelet count decreased without a clinical manifestation, of heparin-induced thrombocytopenia. R-Hirudin treatment monitored by activated partial thromboplastin time and prothrombin time (PT) was effective and safe. The target value for activated partial thromboplastin time was a twofold prolongation. In four of five patients with deep venous thrombosis, a partial recanalization of the lower extremity could be achieved. Three patients with pulmonary embolism associated with deep venous thrombosis in two cases and in one additional case with an acute myocardial infarction did clinically profit from fibrinolysis with recombinant tissue plasminogen activator (rtPA) and r-hirudin treatment. Two lethal events probably caused by the underlying multimorbidity could not be prevented. No recurrence of thrombosis occurred, and there were no severe bleeding complications attributed to r-hirudin treatment. Platelet counts were significantly reduced on day 9.4 plus or minus 6.4 of heparin administration in all cases (>50% decrease related to the initial values) from 224,000 plus or minus 126,000/microL to 96,000 plus or minus 61,000/microL, and increased during rhirudin treatment to mean values of 224,000 plus or minus 126,000/microL. The heparin-induced platelet activation assay (HIPAA) assay was positive in 8/10 cases, whereas the PF4 enzyme-linked immunosorbent assay showed a positive result in four of eight analyzed cases. In four cases, the assays were concordantly positive. The PF4 enzyme-linked immunosorbent assay was not performed in two cases.

Acute myocardial infarction occurring in versus out of the hospital: patient characteristics and clinical outcome. Maximal Individual TheRapy in Acute Myocardial Infarction (MITRA) Study Group

OBJECTIVES

We describe the baseline characteristics and clinical course of patients who had an acute myocardial infarction (AMI) during their hospital stay.

BACKGROUND

In comparison with patients who had an AMI outside of the hospital (prehospital AMI), the data on patients who had an AMI in the hospital are poorly described.

METHODS

Patients with an in-hospital AMI were prospectively registered in the Southwest German Maximal Individual TheRapy in Acute myocardial infarction (MITRA) study and compared with patients with prehospital AMI.

RESULTS

Of 5,888 patients with AMI, 403 patients (6.8%) had an in-hospital AMI. These patients were older, more often male and sicker as compared with the patients with a prehospital AMI. They also showed a higher prevalence of concomitant diseases, such as arterial hypertension, diabetes mellitus, renal insufficiency and contraindications for thrombolysis. There was no significant difference regarding the use of reperfusion therapy, either thrombolysis (in-hospital AMI 44.2% vs. prehospital AMI 49.1%; odds ratio [OR] 0.86, 95% confidence interval [CI] 0.70 to 1.05) or primary angioplasty (9.9% vs. 8.2%; OR 1.23, 95% CI 0.88 to 1.73), or a combination of both, between the two groups. The interval from symptom onset to the start of treatment in patients receiving reperfusion therapy was 55 min for patients with an in-hospital AMI versus 180 min for patients with a prehospital AMI (p = 0.001). In-hospital death occurred in 110 (27.3%) of 403 patients with an in-hospital versus 762 (13.9%) of 5,485 patients with a prehospital AMI (OR 2.33, 95% CI 1.85 to 2.94). This was confirmed by logistic regression analysis after adjusting for other confounding variables (OR 1.67, 95% CI 1.23 to 2.24).

CONCLUSIONS

In-hospital AMI occurred in 6.8% of patients. Time to intervention was shorter; however, the use of reperfusion therapy for in-hospital AMI was not different from that for prehospital AMI. In particular, primary angioplasty seems to be underused in these patients. This, as well as the selection of patients, may result in the high hospital mortality rate of 27.3%.

Diversity of antifungal and plant-associated Serratia plymuthica strains

A total of 21 plant-associated Serratia plymuthica strains were characterized phenotypically by their nutritional patterns, susceptibility to antibiotics, antifungal and haemolytic properties, and genotypically by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA, PCR fingerprints using BOX primers (BOX-PCR) and pulsed-field gel electrophoresis (PFGE) after digestion with SpeI. All of the investigated strains demonstrated antifungal activity in vitro against fungal pathogens while only six strains produced the antifungal antibiotic prodigiosin. Haemolytic activity and antibiotic resistance patterns were investigated to assess the risk associated with the use of isolates in plant protection. The strains were haemolytic at human-relevant temperatures. The level of resistance to antibiotics was low. This work shows that BOX-PCR and PFGE are useful fingerprinting methods to characterize Ser. plymuthica strains, although the discriminatory effect between the two methods differed. Computer-assisted analysis of phenotypic and genotypic features demonstrated relationships between the origin of isolation, the production of prodigiosin and the molecular fingerprint.

Salt adaptation in pseudomonads: characterization of glucosylglycerol-synthesizing isolates from brackish coastal waters and the rhizosphere

The compatible solute glucosylglycerol (GG) is widespread among cyanobacteria, but, until now, has been reported for only two species of heterotrophic bacteria. About 120 bacterial isolates from coastal regions of the Baltic Sea were screened by HPLC for their ability to synthesize GG. Positive isolates (26) were grouped by SDS-PAGE of whole-cell proteins and representative strains of each group were investigated by sequencing their 16S rRNA genes and phenotypic characterization. All GG-synthesizing isolates were shown to belong to the genus Pseudomonas (sensu stricto) and were assigned to 4 distinct groups, although none of the GG-synthesizing isolates could be unambiguously assigned to described species. The identity of GG was verified by 13C NMR analysis and enzymatic digestion with alpha- and beta-glucosidases. Besides GG, salt adapted cultures of the aquatic isolates accumulated the dipeptide N-acetylglutaminylglutamine amide (NAGGN) and glutamate. The accumulation of noncharged compatible solutes was also tested in previously identified pseudomonads isolated from the rhizosphere of oilseed rape and potato. The majority of these strains were fluorescent species of the genus Pseudomonas and accumulated trehalose and NAGGN when grown under salt stress conditions. However, rhizosphere isolates of Stenotrophomonas maltophilia synthesized GG and trehalose or only trehalose in a strain-dependent manner. These data indicate that the ability to synthesize GG is widely distributed among slightly or moderately halotolerant pseudomonads.

Estrogen effects on postural balance in postmenopausal women without vasomotor symptoms: a randomized masked trial

OBJECTIVE

To assess whether estrogen treatment given to postmenopausal women without vasomotor symptoms improves balance more than placebo.

METHODS

Forty healthy postmenopausal women without vasomotor symptoms were randomized to transdermal 17beta-estradiol (E2) 50 microg/day for 14 weeks or identical transdermal placebo patches. Postural balance was measured with dynamic posturography before and after 4, 12, and 14 weeks of therapy. In this test, the visual, vestibular, and somatosensory systems were provoked with increasing difficulty and body sway was measured with a dual forceplate. A low score showed large sway and a score of 100 showed no sway at all.

RESULTS

Thirty-eight women completed the study. Both groups had normal balance for their ages and near maximum scores in the three easier balance tests at baseline. In the most difficult test, both groups improved their postural balance significantly (from 13 to 32 and from 22 to 39, respectively) after 4 weeks. Thereafter, no change was seen. One problem was low statistical power, but the relative change in balance did not differ between groups. The comparison did not show even a minute advantage of E2 over placebo, so a study with higher power would probably not have shown a more pronounced effect of estrogen than placebo. The change over time did not differ between groups, which indicates a significant learning effect.

CONCLUSION

In women without vasomotor symptoms, estrogen therapy did not seem to increase postural balance significantly more than placebo. However, we could not rule out that estrogens affect postural balance in women with vasomotor symptoms.

Prevalence of chronic complications, metabolic control and nutritional intake in type 1 diabetes: comparison between different European regions. EURODIAB Complications Study group

This study compares the prevalence of chronic complications, the quality of metabolic control and the nutritional intake in people with type 1 diabetes in different European regions. The EURODIAB Complications Study included a sample of 3250 European patients with type 1 diabetes stratified for gender, age and diabetes duration. All examinations were performed using standardised, validated methods. HBA1c, LDL-cholesterol and fasting triglycerides were higher in the eastern European centres than in the southern or north-western European centres. Acute (severe ketoacidosis, severe hypoglycaemia) and chronic diabetes complications (retinopathy, nephropathy, neuropathy, cardiovascular disease) were all considerably more frequent in the eastern European centres. HbA1c was lower in the German centres than in the total EURODIAB cohort or in the north-western European centres, but severe hypoglycaemia and proliferative retinopathy were more common. Persons from the eastern European and the German centres consumed undesirably high amounts of cholesterol, total and saturated fat. Overall, improvements in the prevention, detection and management of diabetes complications in persons with type 1 diabetes are essential throughout Europe, particularly in eastern European regions. Since elevated LDL-cholesterol levels and hypertension were strikingly common in this relatively young cohort of European people with type 1 diabetes, generally more attention should be directed towards an adequate management of these cardiovascular risk factors.

Daytime and nighttime differences in patterns of performance of primary angioplasty in the treatment of patients with acute myocardial infarction. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

BACKGROUND

Concern exists regarding the results of primary angioplasty for acute myocardial infarction when the procedure is performed during night hours.

METHODS AND RESULTS

Between June 1994 and January 1997, 491 patients with acute myocardial infarction who underwent primary angioplasty procedures were consecutive registered in the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study. Three hundred seventy-eight patients (77%) were treated during the day and 113 (23%) at night. Baseline characteristics showed no major differences between the 2 groups. Prehospital delay time was 60 minutes shorter during the night (median value 180 minutes for day, 120 minutes for night, P =.005), and in-hospital time to treatment was 9 minutes longer (median value 85 minutes day, 94 minutes night, P =.037). Patients treated during the night more often received angiotensin-converting enzyme blockers (61.4% day, 76.1% night, P =.004) and the so-called optimal adjunctive therapy (54% day, 64.6% night, P =.045). There were no differences concerning clinical events between the 2 groups. Hospital mortality was 8.7% during the day and 5.3% during the night (univariate analysis P =.238; logistic regression P =.653).

CONCLUSIONS

In a clinical setting, primary angioplasty for acute myocardial infarction can be performed safely during the night with a clinically insignificant prolongation of in-hospital time to reperfusion compared with practice during the day.

Chronic infection with Helicobacter pylori does not provoke major systemic inflammation in healthy adults: results from a large population-based study

It has been suggested that chronic infection with Helicobacter pylori (H. pylori), in particular infection with virulent strains producing the cytotoxin-associated protein CagA, may increase the risk of coronary heart disease by generation of a persistent low-grade inflammatory stimulus. We assessed the relation between serological markers of H. pylori infection and various markers of systemic inflammation in a population-based sample of 1834 men and women aged 18-88. A total of 39.3% of the sample had a positive IgG response, and among these a slight majority was CagA positive. Infection with H. pylori was unrelated to C-reactive protein and the leukocyte count, regardless of CagA status. There was an inverse relation between H. pylori infection and serum albumin. The adjusted OR (95% CI) of an albumin level in the bottom versus the top third were 2.2 (1.5-3.1) and 2.0 (1.4-3.1) for infection with CagA-positive and CagA-negative H. pylori strains, respectively. These results do not support the hypothesis that chronic infection with virulent H. pylori strains provokes major systemic inflammation. The mechanisms underlying the inverse association between H. pylori infection and serum albumin and the clinical relevance of this finding require further research.

[Acute pericardial tamponade in cardiac echinococcosis]

An echinococcal cyst of the heart is a rare cause of acute cardiac tamponade. We report on a 24 year old male from the Kosovo who was brought in an emergency state from a provincial hospital complaining of severe dyspnea, thoracic pain, dizziness, and a short period of unconsciousness. Surgical decompression had to be performed urgently, because the pericardium could not be punctuated due to the position of the hydatid cyst. The differential diagnosis was cardiac tumor or echinococcal cyst. Because of a negative result of a test for anti-echinococcal antibodies (indirect haemagglutination) and no eosinophilia (5%), the diagnosis of hydatid cyst was at first discarded. Later on, the test for anti-echinococcal antibodies became positive and a marked eosinophilia (59%) was manifest. In combination with a typical appearance in the echocardiograph and NMR, the diagnosis of a cardiac hydatid cyst was made. After preoperative treatment with albendazole, the cyst was sterilized with a 20% NaCl solution and the contents evacuated. The therapy with albendazole was continued. When last seen eight months after the first incidence, the patient was well except some degree of dyspnea on exertion. As a differential diagnosis of a cardiac tumor, a hydatid cyst should be taken into account in patients from an area where Echinococcus granulosus is endemic. A negative test on antiechinococcal antibodies and the absence of eosinophilia do not rule out echinococcosis.

Genotypic and phenotypic relationships between clinical and environmental isolates of Stenotrophomonas maltophilia

While the gram-negative bacterium Stenotrophomonas maltophilia is used in biotechnology (e.g., for biological control of plant pathogens and for bioremediation), the number of S. maltophilia diseases in humans has dramatically increased in recent years. A total of 40 S. maltophilia isolates from clinical and environmental sources (plant associated and water) was investigated to determine the intraspecies diversity of the group and to determine whether or not the strains could be grouped based on the source of isolation. The isolates were investigated by phenotypic profiling (enzymatic and metabolic activity and antibiotic resistance patterns) and by molecular methods such as temperature-gradient gel electrophoresis of the 16S rRNA gene fragment, PCR fingerprinting with BOX primers, and pulsed-field gel electrophoresis (PFGE) after digestion with DraI. Results of the various methods revealed high intraspecies diversity. PFGE was the most discriminatory method for typing S. maltophilia when compared to the other molecular methods. The environmental strains of S. maltophilia were highly resistant to antibiotics, and the resistance profile pattern of the strains was not dependent on their source of isolation. Computer-assisted cluster analysis of the phenotypic and genotypic features did not reveal any clustering patterns for either clinical or environmental isolates.

[Use of coronary angiography after acute myocardial infarction in Germany: a comparison of daily clinical practice with international guidelines. MITRA Study]

OBJECTIVES

Two third of patients with acute myocardial infarction are admitted to hospitals without cardiac catheterization facilities. Whether a postinfarction patient will undergo cardiac catheterization or not is more often decided by general physicians than by cardiologists. The purpose of this presentation is to investigate the determinants for decision making to use cardiac catheterization in patients after myocardial infarction.

METHODS

MITRA is a prospective, multicenter registry, which enrolls all consecutive patients with acute Q wave infarction admitted to 54 hospitals in Southwestern Germany. During the pilot phase 949 consecutive survivors of acute myocardial infarction were included, and inhospital outcome as well as therapeutic strategies were registered.

RESULTS

Only half of the patients underwent cardiac catheterization regardless of whether a catheterization facility was available or not. In 63% of the patients under 65 years of age coronary angiography was performed; however, every fourth patient with age above 70 years was transferred to an invasive therapeutic strategy. The percentage of male patients was twice a high in the invasive group, whereas patients with prior infarction, clinical signs of congestive heart failure, patients with moderately or severely impaired left ventricular function, and finally patients with a prehospital delay of more than 4 hours were more frequent in the conservative group. The following three parameters were calculated to be independent determinants of an invasive strategy: pathological stress ECG (OR: 2.8; CI: 1.80-4.60), patients < 70 years without stress ECG (OR: 2.18; CI: 1.5-3.18), and male gender (OR: 1.45: CI: 1.10-2.00). Independent factors of a conservative strategy were primary PTCA (OR: 0.2; CI: 0.09-0.46), prehospital delay > 4 hours (OR: 0.71; CI: 0.51-0.97), and the combination of age > 70 years and the absence of a stress ECG (OR: 0.78; CI: 0.55-1.11).

CONCLUSIONS

In Germany, patients with acute myocardial infarction are less likely to undergo cardiac catheterization compared to patients in other Western countries (e.g. , the United States). Despite recommended guidelines, invasive strategies are more frequent in low risk groups (younger patients, male gender) than in postinfarction patients at high risk (severely impaired left ventricular function, clinical signs of congestive heart failure, the elderly).

Lepirudin (recombinant hirudin) for parenteral anticoagulation in patients with heparin-induced thrombocytopenia. Heparin-Associated Thrombocytopenia Study (HAT) investigators

BACKGROUND

We prospectively investigated lepirudin for further parenteral anticoagulation in patients with heparin-induced thrombocytopenia (HIT).

METHODS AND RESULTS

Patients with confirmed HIT (n=112) received lepirudin according to need for 2 to 10 days (longer if necessary): A1, treatment: 0.4 mg/kg IV bolus, followed by 0.15 mg. kg(-1). h(-1) intravenous infusion, n=65; A2, treatment in conjunction with thrombolysis: 0.2 mg/kg, followed by 0.10 mg. kg(-1). h(-1), n=4; and B, prophylaxis: 0.10 mg. kg(-1). h(-1), n=43. Outcomes from 95 eligible lepirudin-treated patients were compared with those of historical control patients (n=120). Complete laboratory response (activated partial thromboplastin time ratio >1.5 with </=2 dose increases and platelet count normalization by day 10) was achieved in 65 lepirudin-treated patients (69.1%; 95% CI, 59. 3% to 78.3%). At 2 weeks after cessation of lepirudin, 11 patients died (9.8%), 10 underwent limb amputation (8.9%), and 20 suffered a new thromboembolic complication (17.9%). The average combined event rate per patient-day decreased from 5.1% in the pretreatment period to 1.5% in the treatment period. Thirty-five days after HIT confirmation, fewer lepirudin-treated patients than historical control patients had experienced >/=1 outcome (cumulative incidence 30.9% versus 52.1%; relative risk [RR] 0.71; P=0.12, log-rank test). Bleeding events were more frequent in the lepirudin group than the historical control group (cumulative incidence at 35 days, 44.6% versus 27.2%; RR 2.57; P=0.0001, log-rank test). No difference was observed in bleeding events requiring transfusion (cumulative incidence at 35 days, 12.9% versus 9.1%; RR 1.66; P=0.23, log-rank test); no intracranial bleeding was observed in the lepirudin group.

CONCLUSIONS

Lepirudin effectively prevents death, limb amputations, and new thromboembolic complications and has an acceptable safety profile in HIT patients. Treatment should be initiated as soon as possible if HIT is suspected.

Hemodynamic effects of double bolus reteplase versus alteplase infusion in massive pulmonary embolism

BACKGROUND

Thrombolytic agents are given in massive pulmonary embolism to dissolve or reduce the clot and normalize hemodynamics. Comparative clinical studies have shown that administration of a 2-hour infusion of alteplase is more effective than urokinase over a 12-hour period. Reteplase is a new generation thrombolytic with a longer half-life that can be administered more conveniently as a double bolus. We compared efficacy and safety of reteplase with the approved regimen of alteplase in massive pulmonary embolism.

METHODS

Thirty-six patients were enrolled and randomly assigned: 23 received reteplase and 13 received alteplase along with intravenous heparin. Reteplase was administered as 2 intravenous bolus injections of 10 U 30 minutes apart, and alteplase was administered as an intravenous infusion of a total dose of 100 mg over a 2-hour period, including an initial 10-mg bolus. Diagnosis of pulmonary embolism was confirmed by selective pulmonary angiography. Hemodynamic monitoring was conducted during the first 24 hours after administration. The primary end point was change in total pulmonary resistance. Secondary variables were pulmonary pressure, cardiac index, clinical parameters, and adverse events.

RESULTS

The primary parameter of total pulmonary resistance showed a significant decrease after just 0.5 hours in the reteplase group and after 2 hours in the alteplase group, with a further decrease persisting for up to 24 hours in both treatment groups. A similar pattern was seen in other directly measured hemodynamic parameters, especially mean pulmonary artery pressure and cardiac index; there was no significant difference between reteplase and alteplase. There was also no apparent difference between the treatment groups with respect to safety, and no stroke or intracranial hemorrhage occurred. The rate of bleedings and the incidence of nonhemorrhagic adverse events were as expected for patients with pulmonary embolism treated with a thrombolytic agent.

CONCLUSIONS

Reteplase is suitable for treatment of massive pulmonary embolism with a standard double bolus 10 + 10 U. Efficacy of reteplase appeared to be at least as good at decreasing pulmonary vascular resistance as that of the approved alteplase regimen of 100 mg infusion over a 2-hour period.

Using information theory to discover side chain rotamer classes: analysis of the effects of local backbone structure

An understanding of the regularities in the side chain conformations of proteins and how these are related to local backbone structures is important for protein modeling and design. Previous work using regular secondary structures and regular divisions of the backbone dihedral angle data has shown that these rotamers are sensitive to the protein's local backbone conformation. In this preliminary study, we demonstrate a method for combining a more general backbone structure model with an objective clustering algorithm to investigate the effects of backbone structures on side chain rotamer classes and distributions. For the local structure classification, we use the Structural Building Blocks (SBB) categories, which represent all types of secondary structure, including regular structures, capping structures, and loops. For classification of side chain data, we use Minimum Message Length (MML) clustering from information theory. We show an example of how MML clustering on data classified by backbone SBBs can reveal different distributions of rotamer classes among the SBBs. Using these preliminary results, some of the characteristics of a rotamer library created using MML clustering on SBB dependent rotamer data are demonstrated.

Does potassium channel opening contribute to endothelium-dependent relaxation in human internal thoracic artery?

Opening of potassium channels can cause hyperpolarization and relaxation of vascular smooth muscle cells. The aim of this work was to investigate the contribution of potassium channel activation to vasorelaxation in internal thoracic artery taken from patients undergoing coronary artery bypass graft surgery. Relaxations to carbachol and sodium nitroprusside were studied in isolated rings of internal thoracic artery in the absence and presence of nitric oxide synthase inhibitors and potassium channel blockers. The nitric oxide synthase inhibitors Nomega-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine abolished relaxations to carbachol. Relaxations to both carbachol and sodium nitroprusside were attenuated in the presence of raised extracellular potassium and the potassium channel blockers charybdotoxin, iberiotoxin and tetraethylammonium. Neither apamin nor glibenclamide modified relaxation. ODQ (1H-[1,2,4]oxadiazolol-[4,3a] quinoxalin-1-one), an inhibitor of soluble guanylate cyclase, abolished relaxation to carbachol in rings from some but not all subjects. These results suggest that potassium channel opening may make a small contribution to endothelium-dependent vasorelaxation in internal thoracic artery. The potassium channels had characteristics consistent with those of large-conductance calcium-dependent potassium channels.

Alcohol consumption and Helicobacter pylori infection: results from the German National Health and Nutrition Survey

Alcohol has strong antimicrobial activity and stimulates gastric acid secretion. Alcohol consumption may therefore compromise the living conditions of Helicobacter pylori in the stomach. We assessed the relation of alcohol consumption with H. pylori infection among 1,785 participants ages 18-88 in the German National Health and Nutrition Survey. Detailed information on dietary and lifestyle habits was obtained in personal interviews using a standardized food frequency questionnaire. Serum samples were analyzed for H. pylori immunoglobulin G antibodies by enzyme-linked immunosorbent assay. Overall prevalence of H. pylori infection was 39.2%. There was a clear inverse dose-response-relation between reported alcohol consumption and H. pylori infection. The relation persisted after control for potential confounding factors. The adjusted prevalence ratios (95% confidence intervals) for H. pylori infection among persons who consumed up to 10, 10 to 20, and more than 20 gm of alcohol per day compared with non-drinkers were 0.93 (0.77-1.13), 0.82 (0.65-1.04), and 0.71 (0.55-0.92). The inverse relation between alcohol consumption and H. pylori infection was even stronger when individuals with an indication of a recent change of alcohol consumption were excluded from the analysis. These findings support the hypothesis that moderate alcohol consumption may facilitate spontaneous elimination of H. pylori infection among adults.