Precise Measurement of the D

We report a measurement of the D^{0} and D^{+} lifetimes using D^{0}→K^{-}π^{+} and D^{+}→K^{-}π^{+}π^{+} decays reconstructed in e^{+}e^{-}→cc[over ¯] data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy e^{+}e^{-} collider. The data, collected at center-of-mass energies at or near the ϒ(4S) resonance, correspond to an integrated luminosity of 72 fb^{-1}. The results, τ(D^{0})=410.5±1.1(stat)±0.8(syst) fs and τ(D^{+})=1030.4±4.7(stat)±3.1(syst) fs, are the most precise to date and are consistent with previous determinations.

[Overcoming of radiation resistances]. / Strahlenresistenzen und ihre Überwindung.

Despite good achievements in prevention and control, cancer is still a leading cause of death worldwide. The development of resistances against conventional treatment modalities is one of the main causes of failure in the treatment of cancer. Radio- and chemotherapies fail frequently due to intrinsic or acquired resistances in apoptotic signalling pathways or alterations in DNA-repair processes. Targeted radiotherapies employing α-particle-emitting radionuclides and Auger-emitting electrons are a promising approach in cancer treatment to break radio- and chemoresistance by overcoming DNA-repair mechanisms and reversing deficient activation of apoptotic pathways in cancer cells.

Insect-Transmitted Urediniospores of the Rust Puccinia punctiformis Cause Systemic Infections in Established Cirsium arvense Plants.

ABSTRACT The rust fungus Puccinia punctiformis has potential as a biological control agent for creeping thistle Cirsium arvense, because systemically infected shoots usually die before flowering. The mechanism of rust transfer as well as the spore type responsible for systemic infections have been a source of controversy. One possibility of successful transmission is the use of the weevil Ceratapion onopordi as a vector. Our results from a garden experiment show that urediniospores transmitted by the weevil are able to induce systemic infections in established thistle clones. Furthermore, the weevil origin and the date of rust treatment significantly influenced the number of rust-infected shoots. The earlier a shoot was treated, the higher the probability of rust transmission. These results challenge the current belief that teliospores passing through the soil and infecting root buds are the major cause of systemic infections in the field. Further research on biological control of creeping thistle should therefore concentrate on the application of urediniospores to enhance systemic rust infections.

The Drosophila proteins Pelle and Tube induce JNK/AP-1 activity in mammalian cells.

The mammalian interleukin-1 (IL-1) signal transduction pathways display remarkable homology to the Toll signaling cascade in Drosophila. To address the question whether members of the Drosophila Toll pathway are functional in mammalian cells, inactive and constitutively active versions of the protein kinase Pelle and its regulator Tube were expressed in HeLa cells and tested for their impact on IL-1-dependent signaling events. The Drosophila proteins failed to induce the IL-1-responsive transcription factor, nuclear factor-kappaB, but selectively activated the IL-1-regulated kinase, c-Jun N-terminal kinase (JNK), thus resulting in elevated AP-1 activity. Activation of JNK/AP-1 activity was seen upon expression of a Pelle mutant lacking its C-terminal half or by a membrane-bound and multimerised Tube protein, showing the functionality of the Drosophila proteins in mammalian cells.

I kappa B-independent control of NF-kappa B activity by modulatory phosphorylations.

Activation of the transcription factor nuclear factor kappa B (NF-kappa B) requires its release from inhibitor of NF-kappa B (I kappa B) proteins in the cytoplasm. Much work has focussed on the identification of pathways regulating this cytosolic rate-limiting step of NF-kappa B activation. However, there is increasing evidence for another complex level of NF-kappa B activation, which involves modulatory phosphorylations of the DNA-binding subunits. These phosphorylations can control several functions of NF-kappa B, including DNA binding and transactivation properties, as well as interactions between the transcription factor and regulatory proteins. Although their overall impact on NF-kappa B function has yet to be determined, modifications of this factor will very probably provide a mechanism to fine tune NF-kappa B function.

Hypericin as a non-antioxidant inhibitor of NF-kappa B.

NF-kappa B is a transcription factor involved in immune and inflammatory responses. Here we show that micromolar concentrations of hypericin inhibited the PMA- and TNF-alpha-induced activation of NF-kappa B in HeLa and TC10 cells, respectively. In contrast, NF-kappa B activated by H2O2 was not influenced by hypericin, indicating a pathway-specificity of hypericin. Hyperforin and a Hypericum perforatum extract standardised on 0.15% hypericin and 5% hyperforin were not active at pharmacologically relevant concentrations. The PMA/TNF-alpha-induced transcription of a reporter gene, which is under the control of the NF-kappa B-dependent IL-6 promoter, was strongly reduced by preincubation with hypericin.

Various glucocorticoids differ in their ability to induce gene expression, apoptosis and to repress NF-kappaB-dependent transcription.

Glucocorticoids (GCs) influence a great variety of cellular functions by at least three important modes of action: the activation (or repression) of genes controlled by binding sites for the glucocorticoid receptor (GR), the induction of apoptosis in lymphocytes and the recently discovered cross-talk to other transcription factors such as NF-kappaB. In this study we systematically compared various natural and synthetic steroid hormones frequently used as therapeutic agents on their ability to mediate these three modes of action. Betamethasone, triamcinolone, dexamethasone and clobetasol turned out to be the best inducers of gene expression and apoptosis. All GCs including the antagonistic compound RU486 efficiently reduced NF-kappaB-mediated transactivation to comparable extents, suggesting that ligand-induced nuclear localization of the GR is sufficient for transrepression. Glucocorticoid treatment of cells did not result in elevated IkappaB-alpha expression, but impaired the tumor necrosis factor (TNF)-alpha-induced degradation of IkappaB-alpha without affecting DNA binding of NF-kappaB. The structural requirements for the various functions of glucocorticoids are discussed.

Substrate vibrations elicit defensive behaviour in leafminer pupae.

Late instar larvae and pupae of the spotted tentiform leafminer Phyllonorycter malella (Ger.) (Lepidoptera: Gracillariidae) react with defensive behaviour when attacked by one of their parasitoids, the eulophid wasp Sympiesis sericeicornis Nees (Hymenoptera: Eulophidae). Vibrations produced during the insertion of the ovipositor into the mine are known to be important cues by which larvae detect the presence of their enemies. The aim of this study was to investigate which frequency components elicit defensive reactions in leafminer pupae using synthetic vibrations. Sine vibrations and bandlimited noise stimuli were offered to both free pupae and pupae concealed in their leafmines. Using Laser vibrometry we measured the vibrations experienced by pupae inside their mines and assessed the influence of the mine. Pupae were shown to react to substrate vibrations, and do so over a broad range of frequencies. Behavioural reactions to noise stimuli were stronger than to pure sine stimuli. Mine tissue attenuated vibration amplitudes of the input signal from 5.1 to 22.6dB. However, as response thresholds of concealed pupae were only twice as high as thresholds of free pupae (which is adequate to 3dB) pupae inside their mine were more sensitive than expected. This discrepancy is discussed both in terms of the conditions of pupae and in terms of mine structure. The results indicate that broadbandedness of vibrations produced by hunting parasitoids during ovipositor insertion into the mine may be a major criterion used by leafminers to perceive parasitoid presence and to escape ovipositor stings.

[Studies of biological availability. A critical assessment based on a study of spironolactone preparations]. / Zur Problematik der Bioverfügbarkeits-untersuchungen. Eine kritische Betrachtung anhand einer Studie über Spironolactonpräparate.

Investigations have been performed to determine the relative bioavailability of canrenone from an improved spironolactone preparation, Deverol drgs., in comparison with canrenone from a spironolactone standard preparation on the Austrian market (Osiren drgs.). This was carried out by comparing the areas under the serumconcentration-time-curves under conditions of steady-state after oral application of both preparations. Additionally the contents of spironolactone in the two preparations tested were determined. By intraindividual comparison of the areas under the serum-concentration-time-curves of canrenone a relative bioavailability of 99.37% of canrenone from Deverol drgs. could be calculated versus canrenone from the standard. However a remarkable different content of spironolactone in the preparations was found: in 50 mg of Deverol drgs. 50.5 mg spironolactone and in 100 mg of Osiren drgs. 109.6 mg spironolactone were found. Determination of drug contents in products appears to be necessary to determine their relative bioavailability correctly, because the usual range of +/- 5% may be overshot as demonstrated in our investigation.

In vivo clearance of antibody-sensitized human drug carrier erythrocytes.

Antibody coating of resealed drug carrier erythrocytes may be useful for drug targeting to the reticuloendothelial system. We have investigated the survival in the circulation of anti-Rh antibody (IgG anti-D)-coated autologous erythrocytes loaded with gentamicin by hypoosmotic dialysis. Five subjects were injected with 15.2 +/- 0.4 ml and five additional subjects with 62.8 +/- 1.5 ml carrier cells. Survival of the cells was monitored by intraerythrocytic gentamicin concentration in blood. In the first subject group initial t1/2 was 0.21 +/- 0.06 hours and terminal t1/2 was 1.71 +/- 0.36 hours. In the second group initial t1/2 was 0.59 +/- 0.21 hours followed by a slow phase with a t1/2 of 89 +/- 28 hours. Results indicate that rapid drug delivery to the reticuloendothelial system by antibody-sensitized carrier erythrocytes is possible, but small volumes of erythrocytes seem more efficient.

Survival of gentamicin-loaded carrier erythrocytes in healthy human volunteers.

Resealed erythrocytes are potential slow release carriers for drugs and enzymes. We have investigated carrier erythrocyte survival in human volunteers using gentamicin (G) as encapsulated cell marker; G was readily incorporated into red cells by hypo-osmotic dialysis (87% efficiency of incorporation) and did not exit from carrier cells in vitro. Six healthy young volunteers were injected with 59 +/- 7 ml carrier erythrocytes containing 56 +/- 13 mg G. G levels were measured in plasma and haemolysed whole blood by RIA. After an initial phase of cell loss (up to 4.5 h post-injection) the carrier erythrocytes survived in circulation with a half-life of 22 days, as was indicated by intracellular G concentration. G levels were detectable in plasma during the first 90 min after injection. This indicates haemolysis of some carrier cells. In conclusion, carrier erythrocytes appear to circulate longer than any other drug carrier under investigation and may well serve as innocuous slow release system.

Erythrocytes as carriers for heparin. Preliminary in vitro and animal studies.

Encapsulation of heparin into resealed carrier erythrocytes may be useful in the prevention of thromboembolism because heparin may be released locally during retraction of fresh thrombi. Heparin encapsulation in human and canine erythrocytes was achieved by hypo-osmotic dialysis with 44% and 36% encapsulation, respectively. Encapsulated heparin did not leak from carrier erythrocytes in vitro. In vivo survival of heparin-loaded carrier erythrocytes in dogs was biphasic: After an initial phase of cell loss the carrier cells survived in circulation with a half-life of 28 h. The present results seem to warrant clinical studies with heparin-loaded carrier erythrocytes.

Pharmacokinetics and bioavailability of isosorbide-5-mononitrate in humans.

The relative bioavailability of isosorbide-5-mononitrate from two different formulations (MONOCLAIR, ISMO) was investigated in a double-blind randomized cross-over study in 8 healthy human subjects. After single orale doses of 40 mg the plasma concentration and the urinary excretion of isosorbide-5-mononitrate were measured over 24 hours. The comparison of the results obtained over the whole experimental period showed a significantly higher plasma concentration with a higher renal excretion after MONOCLAIR, the latter changes being insignificant as compared with those after ISMO, the reference drug. Thus the two formulations are judged to be at least equivalent with regard to their drug bioavailability.

Angiotensin-induced hypertension in conscious dogs: biochemical parameters and baroreceptor reflex.

The effects of a continuous iv infusion (osmotic minipumps) of angiotensin II (80 ng . kg-1 . min-1) and isoprenaline (10 ng . kg-1 . min-1) lasting 28 days were studied in six normotensive, conscious dogs. The parameters measured were systolic and diastolic blood pressure, heart rate, levels of angiotensin II, renin activity, aldosterone and antidiuretic hormone in plasma, baroreceptor reflex sensitivity and body weight. The treatment resulted in an approximately sevenfold increase in plasma angiotensin II level from 62.9 +/- 24.5 pg . ml-1 to 455.3 +/- 95.6 pg . ml-1. Systolic and diastolic blood pressure, measured for the first time 2 days after implanting the minipumps, were markedly increased throughout the infusion period (pretreatment value: 123.8 +/- 5.3/68.3 +/- 3.8 mmHg; after 2 days: 159.8 +/- 12.0/100.5 +/- 9.8 mmHg; after 28 days: 159.8 +/- 7.1/98.3 +/- 6.4 mmHg, whereas the heart rate remained unchanged due to the combined effects of angiotensin II and the concomitantly given isoprenaline. A high correlation was found between angiotensin II level in plasma and mean arterial blood pressure (r = 0.846; p less than 0.001). Furthermore, plasma renin activity was markedly suppressed by the treatment, and aldosterone levels rose. Plasma antidiuretic hormone levels were found to be unchanged at the chosen sampling time. A decrease in baroreceptor reflex sensitivity accompanied the development of the hypertensive state. There was also a loss of body weight during the infusion of angiotensin II and isoprenaline. The data provide evidence for the usefulness of the presented experimental protocol as an alternative model of arterial hypertension in chronically instrumented, conscious dogs.

Characterization of vasodilators by comparison of their effects on blood pressure, counterregulation and myocardial oxygen demand in conscious normotensive dogs.

Vasodilators were characterized on the basis of their first-dose effect on systolic and diastolic blood pressure, heart rate, on the product of heart rate and systolic blood pressure and on plasma renin activity (PRA) in conscious normotensive dogs. The compounds were given orally to the animals and the effects were studied over a period of 4 h. The arterial vasodilators (propyldazine, dihydralazine and labetalol) caused a marked reduction of systolic and diastolic blood pressure with excessive stimulation of the sympathetic nervous system, leading to an increase in myocardial oxygen demand. The blood pressure effect of urapidil and prazosin resembled more the pattern seen with typical venous dilators (molsidomine and nitrates) and was not accompanied by significant increases in heart rate and in PRA. Hence, the magnitude of diastolic blood pressure reduction seems to be an essential determinant of reflex counterregulation. The results prove that some few parameters can give information about the overall pattern of hemodynamic effects of vasodilators.

The influence of repeated administration of prazosin on its hypotensive effect and on renin release in conscious dogs. A comparison with urapidil.

The effects of prazosin (0.1, 0.5 and 2.5 mg/kg, orally) on blood pressure, heart rate and PRA were investigated after acute and chronic administration in conscious, normotensive dogs. The acute administration of prazosin caused a reduction in both systolic and diastolic blood pressure and an increase in heart rate and PRA. After chronic administration, twice daily for four days, tolerance developed, which was not due to persistent counterregulation. On comparison with urapidil, another alpha-adrenoceptor antagonist, the hypotensive and counterregulatory response to acute administration were similar with both substances; the development of tolerance to prazosin after chronic administration contrasted with the results with urapidil.

Altered blood pressure response to propyldazine after repeated oral administration in conscious normotensive dogs: role of the renin-angiotensin system.

The magnitude and the persistence of blood pressure reduction by propyldazine (PDZ) was investigated following treatment over a period of 4 days. The experiments were performed on 6 normotensive dogs trained to submit to puncture of the femoral artery and to stand quietly in a special frame over the experimental period of 7 to 8 hours. The first dose effect of orally administered PDZ (0.06, 0.29 and 1.42 mg/kg) on heart rate, arterial blood pressure and plasma renin activity (PRA) was compared with the effect of the substance after treatment at the same respective dosage twice daily over 4 days. The compound caused a dose-dependent decrease in blood pressure accompanied by dose-dependent increases in heart rate and PRA. With 0.06 mg/kg and 0.29 mg/kg PDZ a sustained effect on arterial blood pressure was observed, whereas with 1.42 mg/kg PDZ tolerance occurred after treatment over the 4-day period. A comparison with the effects observed previously with 1.42 and 7.1 mg/kg dihydralazine (DHZ) under identical conditions showed similar results with respect to dose-dependence of blood pressure and counterregulation (1). It is considered that with a low-dose regimen there would be no decrease in activity of PDZ, the long-term hypotensive efficacy of the drug thereby being guaranteed.

Effects of acylcarnitine-transferase blocking agent sodium 2[5-(4-chlorophenyl)-pentyl]-oxirane-2-carboxylate (POCA) on cardiodynamics and myocardial metabolism in dogs.

An investigation is presented of the effects of the acylcarnitine-transferase blocking agent sodium 2[5-(4-chlorophenyl)-pentyl]-oxirane-2-carboxylate (POCA; 20 mg/kg i.v.) on cardiodynamics and myocardial metabolism in normoxic, anesthetized dogs. POCA induced an initial increase in pulmonary vascular resistance; pulmonary vascular pressure was increased up to 4 h. All other hemodynamic parameters were unchanged. POCA induced a continuous rise in arterial free fatty acid (FFA) level and a marked initial increase in arterial lactate level. Arterial glucose level decreased. Myocardial FFA uptake was almost completely inhibited by POCA; myocardial lactate uptake increased markedly and myocardial glucose uptake remained unchanged. These changes were accompanied by an increase in respiratory quotient from 0.72 to 1.0 and a decrease in myocardial oxygen consumption by 15-20%. In conscious dogs, POCA (20 mg/kg i.v.) induced similar changes in arterial substrate levels. The increase in arterial FFA level was accompanied by an increase in arterial glucagon. Ketone body levels decreased initially but increased simultaneously with glucagon levels. These findings confirm the efficacy of POCA in inhibiting FFA oxidation and, consequently, in decreasing myocardial oxygen consumption. However, possible deleterious effects of the increase in arterial FFA levels on the ischemic myocardium require further experimental evaluation.