Facilitating interaction between rauwolscine and angiotensin in the mesenteric artery of the rabbit

Summary The interaction between rauwolscine and angiotensin II was investigated in the isolated mesenteric artery of the rabbit. Rauwolscine, known as an antagonist at ₂-adrenoceptors, did not induce contraction itself but interacted with angiotensin to produce a facilitated response of the vascular tissue. In the presence of rauwolscine, the contractile response of the tissue to angiotensin was markedly enhanced. The degree of facilitation appeared to be dependent on the rauwolscine concentration used rather than that of angiotensin. Moreover, rauwolscine induced a concentration-dependent increase in tension (pD₂=6.8) in the presence of even subcontractile concentrations of angiotensin (10^–10 mol/l). This effect was not attributable to an indirect action involving presynaptic catecholamines, as revealed by the use of tissue strips from animals pretreated with reserpine or after chemical sympathectomy. Furthermore, an interaction via the prostaglandin system was excluded by negative results obtained with indomethacin. The agonistic effect of rauwolscine was significantly attenuated by phentolamine (₁/₂) but not by prazosin (₁) or phenoxybenzamine when applied for only a short time. The ₂-antagonist BDF 6143 behaved like rauwolscine whereas the ₁-antagonist corynanthine, a stereoisomer of rauwolscine, did not. The results indicate that the rauwolscine effect is mediated by a receptor with ₂-characteristics. In general, angiotensin appears to interfere with some process which determines the expression of a drug's intrinsic effect.This study was supported by a grant of the Deutsche Forschungsgemeinschaft     

Patient and public involvement cultures and the perceived impact in the vulnerable context of palliative care: A qualitative study

BackgroundCultural values are crucial to the practice and impact of patient and public involvement (PPI) in research.ObjectiveTo understand different PPI cultures among research teams and the impacts of PPI associated with each culture type.DesignA participatory action research design.Setting and participantsThe setting was 10 palliative care research projects. Seventeen patients and members of the public and 31 researchers participated.InterventionA programme consisting of four components: (1) training and coaching of patients and the public to prepare them for participation in research, (2) tailored coaching of the 10 research teams over 12‐18 months, (3) a community of practice, and (4) a qualitative evaluation.ResultsWe identified three cultures types: relationship cultures, task cultures, and control cultures. We identified four areas of impact: the project aim became more relevant to the target audience, methodological reliability increased, the research products were better able to reach the public, and the awareness increased, associated with behavioural changes, among researchers regarding PPI.DiscussionA relationship culture appears to be long‐lasting due to impacting the behaviours of the researchers during future projects. Different cultural types require different types of patients and researcher participants, assigned to different tasks.ConclusionsFurther research remains necessary to investigate the support required by researchers to enable relationship‐ and task‐oriented PPI cultures.Patient or public contributionPatient advocates and representatives contributed to our research team throughout the entire research process, as well as within the 10 implementation projects.     

Impact of COVID-19 pandemic lockdown on myocardial infarction care

European Journal of Epidemiology - The aim of this study was to evaluate the impact of the COVID-19 pandemic lockdown on acute myocardial infarction (AMI) care, and to identify underlying stressors...     

Radon progeny unattached fraction in an atmosphere far from radioactive equilibrium

It is often assumed that the unattached fraction of the exposure to suspended radon progeny activity can be predicted from particle concentration measurements. While this may be true in many circumstances, there are important exceptions to this rule. In particular, in an atmosphere far from radioactive equilibrium, such as a working area in a mine close to a source of radon and supplied with fresh air, the unattached fraction can be a factor of ten or more greater than indicated by a simple particle concentration measurement. Recent measurements made in a diesel powered uranium mine are presented to illustrate this effect.     

Mechanical properties of normal andmdx mouse sarcolemma: Bearing on function of dystrophin

Summary The tensile strength of the muscle fibre surface membrane was estimated (1) from the suction required to burst membrane patches and (2) by aspiration of sarcolemmal vesicles into micropipettes of uniform bore. Each method gave an average value close to 60 N cm^–1 for the maximum tension sustainable by normal mouse sarcolemma and only slightly lower values for sarcolemma frommdx mice which lack dystrophin. The elastic modulus of area expansion, as measurable by pipette aspiration of sarcolemmal vesicles, was found to have an average value of 3160 N cm^–1 for normal and 2770 N cm^–1 formdx mouse sarcolemma.The tensile strength of the sarcolemma is much too small for any differences in it to be the basis for the different osmotic behaviour of normal andmdx muscle fibres reported recently (Menke & Jockusch, 1991). By analogy with the better understood origin of the osmotic fragility of different types of red blood cells, the higher osmotic fragility ofmdx muscle fibres is suggested to be of morphological origin. We postulate that dystrophin functions as an element of the submembrane cytoskeleton so as to maintain the normal folding which safeguards the sarcolemma against mechanical damage.     

Depth-discrimination in direct 3D-scanning without image reconstruction using a coincidence technique

A 3D-scanner for direct three-dimensional imaging using a --coincidence technique is presented. The characteristics of the system were demonstrated by isoresponse curves and modulation transfer functions. A phantom study showed the possibility of detecting cold nodes when they are invisible in normal scans in large subjects because of masking by overlying activity.     

Does the participation of a surgical trainee adversely impact patient outcomes? A study of major pancreatic resections in California

BACKGROUND: Some patients have concerns regarding the impact of surgical trainees on the quality of care that they receive in teaching hospitals. No population-based data exist that describe outcomes of surgical procedures in teaching and nonteaching hospitals; however, institutional data suggest that teaching hospitals provide high-quality care. We hypothesized that the presence of a general surgery residency program (GSRP) is associated with superior outcomes for pancreatic resection, a complex surgical procedure. METHODS: A retrospective, population-based, risk-adjusted analysis of 5696 patients who underwent major pancreatic resection compares the outcomes of patients treated at hospitals with a GSRP (GSRP+) and those hospitals without a GSRP (GSRP-). RESULTS: GSRP+ hospitals had a lower operative mortality rate (8.3% vs 11.0%; P <. 001), a lower percentage of patients discharged to another acute care hospital or skilled nursing facility (6.5% vs 13.0%; P <.001), and a longer length of stay compared with GSRP- hospitals (22.1 +/- 0.4 days vs 19.6 +/- 0.3 days; P <.001). The observed difference in hospital mortality rates was not significant after an adjustment was made for patient mix and hospital volume (9.7% vs 10.0%). However, superior outcomes were found in the university teaching hospitals, as compared with the affiliated teaching and the nonteaching hospitals (5.3% [P <.001] vs 11.4% vs 11.0%; risk adjusted, 8.0% [P <.05] vs 10.9% vs 10.0%). CONCLUSIONS: The presence of surgical trainees does not have an adverse impact on the quality of care for One complex procedure, pancreatectomy, and is associated with superior operative mortality rate in university teaching hospitals.     

Methylated DNA collected by tampons--a new tool to detect endometrial cancer.

This proof of principle study aimed to define a new and simple strategy for detection of endometrial cancer using epigenetic markers. We investigated DNA isolated from vaginal secretion collected from tampon for aberrant methylation of five genes (CDH13, HSPA2, MLH1, RASSF1A, and SOCS2) using MethyLight in 15 patients with endometrial cancer and 109 patients without endometrial cancer. All endometrial cancer patients revealed three or more methylated genes, whereas 91% (99 of 109) of the patients without endometrial cancer had no or fewer than three genes methylated in their vaginal secretion. The methods developed in this study provide the basis for a prospective clinical trial to screen asymptomatic women who are at high risk for endometrial cancer.