Einflu\ eines Β1-Rezeptorenblockers auf die Plasmaspiegel des atrialen natriuretischen Peptids bei Patienten mit essentieller Hypertonie unter Ergometerbelastung

Summary In order to investigate the behaviour of atrial natriuretic peptide (ANP) in untreated mild to moderate essential hypertension and the influence of blood pressure normalisation by a ₁-receptor blocker a study was conducted in groups of normotensive and hypertensive middle aged subjects. 10 normal subjects and 10 patients with essential hypertension (WHO I–II) without any medication and on betaxolol monotherapy were studied at rest and during graded exercise. In addition the response of ANP, cyclic guanosine monophosphate (cGMP) and the renin-aldosterone-system was investigated.Normal subjects and hypertensive patients did not differ in ANP levels at rest and also responded with a comparable exercise dependent increase at all workload levels. A steady decrease of ANP was noticed during the recovery period in both groups. After-blocker treatment in the hypertensive patients ANP concentrations significantly rose, both at rest and more pronounced during exercise. cGMP reacted in a similar way but showed a more inert response. A counter-regulatory behaviour between ANP and PRA or aldosterone, as seen under volume shifts, could not be detected. These findings demonstrate that plasma ANP is not altered in untreated essential hypertension. Increased ANP levels in ₁-blocker treatment may contribute to its blood lowering effect.

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Abkürzungsverzeichnis ANP atriales natriuretisches Peptid - ALD Aldosteron - C_In Inulin Clearance - cGMP zyklisches Guanosinmonophosphat - irANP immunoreaktives atriales natriuretisches Peptid - PAH Paraaminohippursäure - PRA Plasma-Renin-Aktivität - RAA-System Renin-Angiotensin-Aldosteron-System - RBF renaler Blutflu - RIA Radioimmunoassay - RVR renaler Gefä\widerstand     

Effect of regular training on the anthropometric parameters and urine steroids in childhood

The changes in the anthropometric data and urine steroid metabolites caused by regular training in children in two age groups (11 and 14 years old) were investigated. The skinfolds of older girls participating in regular athletic, swimming or soccer training were thinner compared with age-matched control groups (P < 0.01) and their body mass and constitution were lower (P < 0.05). In the other groups no significant differences were observable in the anthropometric parameters. The trained children in all groups had significantly higher exercise times on the cycle ergometer (P < 0.01, in young boysP < 0.05). The strength of their hands was lower in three trained groups: in younger boys (P < 0.05), in younger girls (P < 0.01) and in older girls (right handP < 0.01, left handP < 0.05). The urinary excretion of androsterone (P < 0.02), 11-ketopregnanetriol (P < 0.01) and pregnenetriol (P < 0.02) was decreased in the older trained girls; pregnenetriol was increased in younger boys (P < 0.05). Urinary excretion of cortisol metabolites was increased in trained boys [in younger boys: tetrahydrocorticosterone (P < 0.05) and 20-hydroxycortisol (P < 0.05); in older boys allotetrahydrocortisol (P < 0.02), cortisol (P < 0.05) and 20-hydroxycortisol (P < 0.05)]. There were no significant differences in the younger girls. In the trained older girls urinary excretion of cortisol metabolites was decreased: tetrahydrocortisone (P < 0.02), allotetrahydrocorticosterone (P < 0.01), tetrahydrocortisol (P < 0.05), -cortolone (P < 0.01), cortisol (P < 0.02), 6-hydroxycortisol (P < 0.01) and 20-hydroxycortisol (P < 0.05). A multivariate analysis of the data from the trained groups and sedentary, age-matched control groups showed that regular training has a significant effect on steroid excretion.     

The emergency medicine training needs of rural general practitioners

This study aimed to identify the emergency medicine training needs of rural general practitioners (GPs) in the catchment area of the Hunter Rural Division of General Practice. The GPs were surveyed using a questionnaire in which they were asked about their confidence levels in a number of specific emergency medicine skills, and about the areas of emergency medicine that they saw as priorities for upskilling. More than a third of GPs who were responsible for on-call work at the hospital indicated that they had low levels of confidence in a number of their emergency medicine skills, in particular skills relating to paediatric emergencies, cardiovascular emergencies, and respiratory emergencies. These emergency medicine domains were also seen as high priorities for upskilling by the majority of the respondents. The study shows that rural doctors need the opportunity to access emergency medicine training that provides upskilling not only in the management of clinical problems, but also in practical procedures.     

Prevention of anterior cruciate ligament injuries in soccer

Proprioceptive training has been shown to reduce the incidence of ankle sprains in different sports. It can also improve rehabilitation after anterior cruciate ligament (ACL) injuries whether treated operatively or nonoperatively. Since ACL injuries lead to long absence from sports and are one of the main causes of permanent sports disability, it is essential to try to prevent them. In a prospective controlled study of 600 soccer players in 40 semiprofessional or amateur teams, we studied the possible preventive effect of a gradually increasing proprioceptive training on four different types of wobble-boards during three soccer seasons. Three hundred players were instructed to train 20 min per day with 5 different phases of increasing difficulty. The first phase consisted of balance training without any balance board; phase 2 of training on a rectangular balance board; phase 3 of training on a round board; phase 4 of training on a combined round and rectangular board; phase 5 of training on a so-called BABS board. A control group of 300 players from other, comparable teams trained normally and received no special balance training. Both groups were observed for three whole soccer seasons, and possible ACL lesions were diagnosed by clinical examination, KT-1000 measurements, magnetic resonance imaging or computed tomography, and arthroscopy. We found an incidence of 1.15 ACL injuries per team per year in the control group and 0.15 injuries per team per year in the proprioceptively trained group (P<0.001). Proprioceptive training can thus significantly reduce the incidence of ACL injuries in soccer players.     

Regulation of PaCO2 during rest and exercise: A modeling study

A nonlinear mathematical model of the CO₂ control system was used to examine a number of issues concerning the regulation of PaCO₂ during rest and exercise. To gain insight to the regulatory properties of the respiratory system, the open loop gain (G_l) and closed loop sensitivities S_i=ξPaCO₂/ξPiCO₂ and were calculated. Gl indicates the ability of a control system to regulate the controlled variable, PaCO₂ in the model. Si and Sv represent the change in PaCO₂ to unit changes in PiCO₂ and , respectively. Model predications were obtained for rest and various intensities of exercise for the following challenges to the respiratory system: (a) CO₂ inhalation, (b) i.v. CO₂ loading, (c) application of an external dead space, and (d) a shift in the resting operating point. Increasing exercise intensity produced a substantial decrease in Gl and increase in Si consistent with the hypothesis that exercise degrades the ability of the respiratory system to regulate PaCO₂. However, Sv decreased indicating that the respiratory system would actually be better able to regulate PaCO₂ if there were fluctuations in . Thus, Gl does not completely describe the regulatory characteristics of the respiratory control system. It is demonstrated that the regulatory characteristics of the respiratory system as described by Gl, Si, and Sv are complex and depend on the nature of the challenge. Techniques for systematically describing the regulatory properties of the CO₂ control system are described.     

Continuous monitoring of extracellular lactate concentration by microdialysis lactography for the study of rat muscle metabolism in vivo

A method is described for the measurement and on-line monitoring of muscular extracellular lactate concentration in both anaesthetized and freely moving rats. This method is based on microdialysis sampling and lactic dehydrogenase-catalysed nicotinamide adenine dinucleotide, reduced (NADH)-fluorescence detection techniques. In vivo calibration revealed a resting extracellular lactate concentration of 1.92±0.13 mmol/l (± SEM) in the gastrocnemius muscle of adult male Wistar rats (n=6), while the average whole-blood lactate level was 0.76±0.12 mmol/l (± SEM). This measured extracellular lactate concentration was 1.73-times higher than that deduced from the arterial lactate concentration. Blocking glycolysis with iodoacetate reduced the extracellular lactate concentration to 52±6% (± SEM, n= 4) of the resting level. The extracellular lactate concentration in rat gastrocnemius muscle had increased to significantly (P0.05) different levels, 2.4±0.03 (± SEM) or 4.0±0.55 (± SEM) times the control value, 1 h after aortic clamping (n=3) or cardiac arrest (n=3), respectively. Stimulation of the sciatic nerve induced elevations of the extracellular lactate concentration in the tibialis anterior muscle which were linearly related to the recorded isometric force-time integral. We also monitored on-line the changes in extracellular lactate concentration in the tibialis anterior muscle of a swimming rat. Our results indicate that microdialysis lactate reflects also intracellular metabolism. Lactography may be a useful alternative to biopsies and nuclear magnetic resonance spectroscopy in clinical medicine and physiology for the monitoring of metabolism in vivo.     

Treatment of defaecation problems in children: the role of education, demystification and toilet training

To evaluate the effect of education in children with chronic defaecation problems, a prospective 6-week intervention study was designed. A total of 54 children (5–14 years) underwent an education programme, with demystification of symptoms and advice about diet and toilet training. The present treatment was continued. After 6 weeks, children with persistent problems received biofeedback training with a follow up of 1 year. The intervention programme was successful in 8 children (15%). Biofeedback training was successful in 49% of the remaining group after 1 year. Conclusion A total of 15% of the children with chronic defaecation problems seen at a referral centre could surprisingly be helped by a simple education programme with, demystification and toilet training. Further studies evaluating treatment in children with defaecation problems should account for the primary effect of these measures. Received: 30 July 1996 and in revised form: 30 November 1996 / Accepted: 11 January 1997     

Otorhinolaryngological training in Europe—a comparative study

Postgraduate training in the United Kingdom is undergoing radical changes following the `Calman Report'. Commissioned in response to a European Union (EU) Directive, this contained recommendations to allow reciprocal recognition of all EU trained specialists. We present the findings of a postal questionnaire sent to representatives of the European Federation of Oto-Rhino-Laryngological Societies and the otolaryngology professors of the UK and Ireland with a response rate of 62.7%. Aspects assessed included clinical and surgical experience, examinations, teaching, research, length, regulation and perception of training. The programmes share similar teaching and research experience but substantial differences exist in most other areas. The accredited UK trainee has a much wider clinical and surgical repertoire than those from the Continent. Greek trainees were trained to the lowest minimum standard. The requirements of a training system are largely determined by the level of clinical experience and surgical skill required by an independent specialist in a given country.     

How to organize gynecologic oncology in the future: Results of an internationalquestionnaire

Vergote IB, de Oliveira CF, Dargent D. How to organize gynecologic oncologyin the future: Results of an international questionnaire. Int J GynecolCancer 1997; 7: 368–375.
A questionnaire was sent to 93 gynecologic oncologists from 54 countriesabout the way in which gynecologic oncology was organized in their country, orif the (sub)speciality wasnot yet recognized, how they thought it should be organized. The questionnairewas answered by 64 persons from 42 different countries. The subspecialty wasrecognised in 17 (41%) of the countries. Fifty-five respondents (86%) thought thatgynecologic oncology should be a subspecialty of obstetrics and gynecology. Themedian duration of the gynecologiconcologic fellowship program was 30 months. Diagnosis and surgery accounted forabout 58% of the duration of the program. In 52% of the answersfrom countries with boardcertification, the fellows had to pass a theoretical and practical examination,and in addition 22% of the candidates had to defend a thesis to qualifyfor certification.Training centers in countries that recognized gynecologic oncology had amedian number of 142 new cases per year (for 1 fellow). The median number ofgynecologic oncologogistsand fellows per 10⁽⁷⁾ inhabitants in countries with boardcertification in gynecologic oncology was 42 and 6, respectively. Finally, theimportant role of internationalsocieties (like the International Gynecologic Cancer Society and the EuropeanSociety of Gynaecological Oncology) in supporting the countries withoutrecognized GynecologicOncology was stressed by the respondents. The setting up of internationalstandards for training programs, training centers, board certification, and theorganization ofinternational exchange programs for fellows seemed to be equally important,according to the questionnaire responses.