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Refeeding inpatients with anorexia nervosa (AN) is costly, stressful, and can precipitate the refeeding syndrome. Caloric intake is usually increased gradually from a low starting point until a steady weight gain is achieved. There is no reliable equation that predicts the number of calories required for a weight gain. It was our clinical suspicion that anxiety, exercise, and cigarette smoking might increase the caloric need for refeeding. We conducted an observational cohort study of 17 females with AN admitted to an inpatient eating disorder unit for refeeding. We estimated the energy intake by observation, the caloric expenditure due to exercise with a triaxial accelerometer, the number of cigarettes smoked by history, and the anxiety by the Beck Anxiety Inventory (BAI). Neither anxiety, exercise, or cigarette smoking predicted the caloric requirement for refeeding, individually or in combination. Discussion: Our data suggest that the caloric requirement for weight gain during refeeding is not predicted by the patient's anxiety, exercise or smoking habits. The standard methods of estimating caloric requirements for refeeding remain indirect calorimetry and previous history.

We present the case of a 24-year old female with recurrent fainting attacks. Surface ECG revealed QT prolongation. There were no arrhythmias during several months of monitoring using a wearable external defibrillator (WCD®). Eight months after implantation of an ICD, the patient experienced syncope with appropriate shock for polymorphic ventricular tachycardia. Diagnostic criteria and treatment options for the congenital long QT syndrome are discussed briefly. Wir berichten über eine 24-jährige Patientin mit rezidivierender Bewusstlosigkeit. Das Oberflächen-EKG zeigte eine QT-Verlängerung. Während einer sechsmonatigen Überwachungsphase mit einer tragbaren Defibrillatorweste (WCD®) konnten keine Arrhythmien dokumentiert werden. Acht Monate nach der Implantation eines ICD hatte die Patientin eine Synkope. Die Abfrage des ICD zeigte eine polymorphe Kammertachykardie, die durch einen Schock beendet wurde. Diagnostische Kriterien und Behandlungsoptionen für das kongenitale Long-QT-Syndrom werden diskutiert.

The Wearable Cardioverter Defibrillator (WCD®) is an external defibrillator that automatically detects and treats ventricular tachyarrhythmias without the need for assistance from a bystander while at the same time allowing the patient to ambulate freely. The main components of the system are the defibrillator unit and a chest belt with electrodes for arrhythmia detection and therapy delivery. ??Between December 1998 and October 2001, 84 patients used the device at our institution. The majority of patients had a history of acute myocardial infarction or coronary artery bypass surgery with an increased risk for sudden cardiac death or were awaiting heart transplantation. During a mean follow-up of 116±90 days, 7 episodes of ventricular tachyarrhythmias were detected and terminated successfully by the WCD® in 5 patients. In 9720 days, there was one inappropriate shock due to oversensing of electrical noise. Four patients died during follow-up; none of them had a cardiac arrest while wearing the device. Five patients were excluded because of irregularities in device use. An ICD was implanted in 24 patients at the end of the follow-up period. ??The WCD® is effective in detecting and treating ventricular tachyarrhythmias in patients with an intermittently increased risk for sudden cardiac death. Further use of the system in larger patient populations is needed to confirm its safety and cost effectiveness. Der tragbare Kardioverter/Defibrillator (WCD®) ist ein externer Defibrillator, der ventrikuläre Tachyarrhythmien automatisch erkennt und ohne Hilfe von medizinischem Personal oder Laien durch Abgabe von bis zu fünf Gleichstromschocks behandelt und dem Patienten gleichzeitig vollständige Mobilität gewährleistet. Die beiden Hauptkomponenten sind die tragbare Defibrillatortasche sowie eine Elektrodenweste mit einem Gürtel, die vom Patienten angelegt wird. ??Zwischen Dezember 1998 und Oktober 2001 wurden in unserer Einrichtung 84 Patienten mit einem WCD® versorgt. In der Mehrzahl der Fälle handelte es sich um Patienten nach akutem Myokardinfarkt oder herzchirurgischem Eingriff, bei denen das Risiko für einen plötzlichen Herztod zeitweilig erhöht war, oder um Patienten, die sich auf einer Warteposition für die Herztransplantation befanden. Während einer mittleren Nachbeobachtungszeit von 116±90 Tagen wurden bei fünf Patienten sieben Episoden einer ventrikulären Tachyarrhythmie automatisch durch den WCD® detektiert und durch Abgabe eines monophasischen Schocks erfolgreich terminiert. Während einer Gesamtanwendungsdauer von 9720 Tagen kam es zu einem inadäquaten Schock aufgrund von Oversensing. Vier Patienten verstarben im Verlauf der Nachbeobachtung. Bei keinem dieser Patienten trat ein arrhythmiebedingter Herztod auf, während der WCD® getragen wurde. Fünf Patienten wurden aufgrund unregelmäßiger Tragezeiten von der Studie ausgeschlossen. Bei 24 Patienten wurde am Ende der Tragezeit ein implantierbarer Kardioverter/Defibrillator implantiert. ?? Der WCD® ist in der Lage, ventrikuläre Tachyarrhythmien bei Patienten mit einem intermittierend erhöhten Risiko für einen arrhythmiebedingten Herztod sicher zu erkennen und automatisch zu behandeln. Unsere ersten Erfahrungen zeigen, dass es mit dem WCD® möglich ist, einen begrenzten Zeitraum mit einem erhöhten Arrhythmierisiko zu überbrücken.

The limited efficacy of and side effects associated with antiarrhythmic drug therapy have led to renewed interest in non-pharmacologic treatment options for paroxysmal atrial fibrillation. In addition to catheter ablation of the initiating ectopic atrial beats, electrical stimulation of the atrium is a new and promising method to reduce the frequency of arrhythmia recurrences. Recent studies have confirmed the importance of both the initiating triggers and the electrophysiologic substrate for the recurrence and perpetuation, respectively, of atrial fibrillation. Bradycardia and pauses, atrial premature beats, and early recurrence of atrial fibrillation all seem to play an important role for (re-)initiation of an episode. Results from single-site atrial pacing in the high right atrium have shown a reduction of atrial fibrillation episodes and progression into chronic atrial fibrillation in selected groups of patients (brady-tachycardia syndrome and vagally induced atrial fibrillation). Therefore, specific preventive pacing algorithms (atrial overdrive pacing, rate smoothing or rate acceleration after detection of atrial premature beats and termination of a mode-switch) and new pacing sites have recently been investigated in order to address all of these initiation mechanisms and to increase the efficacy of pacing. In studies published so far, the specific pacing algorithms seem to add benefit compared to atrial-based demand (AAI or DDD) pacing alone. Finally, attempts are being made to terminate recurrences of atrial tachycardia or atrial flutter with antitachycardia pacing algorithms in order to avoid progression into atrial fibrillation. Based on experimental and clinical evidence, the initial phase of the majority of atrial tachyarrhythmia recurrences is not ‘leading circle reentry’. Most episodes start relatively regular and seem to have an excitable gap, allowing capture and pace termination. Die begrenzte Effektivität und das ungünstige Nebenwirkungsspektrum der medikamentösen antiarrhythmischen Therapie hat zu einem gesteigerten Interesse für nicht-medikamentöse Therapieoptionen von Vorhofflimmern geführt. Neben der Katheterablation stellt die Stimulation eine interessante Möglichkeit dar, die Rezidivrate von paroxysmalem Vorhofflimmern zu reduzieren. Auf Grund neuerer Untersuchungen spielen neben dem elektrophysiologischen Substrat eine Reihe von Auslösemechanismen (,Trigger‘) eine Rolle beim Auftreten von Vorhofflimmern. Gegenüber der Vorhof-gesteuerten (AAI oder DDD) Demand-Stimulation scheinen spezifische präventive Stimulationsalgorithmen, die sich gegen die einzelnen inzwischen bekannten Auslösemechanismen des Vorhofflimmerns richten, und die Optimierung des Stimulationsortes eine weitere Reduktion der Häufigkeit der Vorhofflimmerepisoden zu ermöglichen. Zusätzlich wird in der letzten Zeit der Versuch gemacht, trotz präventiver Stimulation aufgetretene Episoden von Vorhofflattern und atrialen Tachykardien mit Hilfe einer antitachykarden Stimulation früh wieder zu terminieren und so den Übergang in Vorhofflimmern zu verhindern. Die Aufzeichnungen mit Hilfe implantierbarer Aggregate und der Erfolg der Überstimulation legen nahe, dass ein Teil der klinisch beobachteten Episoden von Tachyarrhythmien relativ regelmässig beginnt und initial eine erregbare Lücke besitzt und so eine Pace-Terminierung erlaubt und erst zu einem späteren Zeitpunkt in funktionellen (,leading circle‘) Reentry übergeht.

Although radiofrequency (RF) catheter ablation has been shown to be an effective treatment strategy in patients with supraventricular tachycardia, RF ablation may lead to potentially serious complications. We describe a case of a 65-year old man who was transferred for catheter ablation of typical atrial flutter. 21 RF applications (mean energy: 81±9 watts) were applied in the temperature-controlled mode (70[emsp4 ]°C) between a 8-mm tip electrode and an indifferent electrode using a high-power RF generator (100 watts) until bi-directional atrial isthmus block was achieved. After the procedure, a third-degree skin burn (10×2[emsp4 ]cm) was observed at the lateral edge of the adhesive indifferent electrode whereas the medial edge of the electrode was not fully attached to the skin surface. This case is one out of 1128 ablation procedures (0.09%) at our institution using a high-power RF generator. The present study demonstrates a severe skin burn induced by mal-attachment of an indifferent electrode during RF ablation. Long RF energy application times, high-power settings, and heavy sedation may have contributed to the observed severity of skin damage.

Electrical atrial remodeling during rapid atrial activation is known to be an important phenomenon for perpetuation of atrial fibrillation. Recent studies have demonstrated that electrical remodeling is mediated by an increase in calium currents through L-type calcium channels during atrial fibrillation. Electromechanical factors may also contribute to the observed shortening in the effective refractory period (ERP) during atrial remodeling. The purpose of our study was to examine the influence of right atrial pressure on electrical remodeling during high frequency pacing in an intact animal model. Methods:10 closed-chest dogs (25±1kg) were studied during continuous autonomic blockade with i.v. Atropine (bolus: 0.04mg/kg followed by 0.007mg/kg/h) and i.v. Propranolol (bolus: 0.2mg/kg followed by 0.04mg/kg/h). The right atrial appendage was paced for 7 hours at a rate of 800bpm (4mA). Right atrial pressure and systemic blood pressure were continuously recorded. Atrial ERP was determined at a different right atrial site every hour at a basic cycle length of 350ms. After 7h pacing, animals were divided into two groups according to the mean right atrial pressure (group 1: 4±0.2mmHg versus group 2: 7±1mmHg; p<0.01). Results:Despite autonomic blockade, significant electrical remodeling was observed in all animals. The decrement in ERP was significantly greater in group 2compared to group1 (group1: 166±12ms to 145±16ms versus group2: 164±14ms to 126±17ms; p<0.05). The duration of induced atrial fibrillation was significantly longer in group 2 compared to group1 (59±22s vs. 19±12s; p<0.05). The mean AF cycle length was not significantly different in both groups (135±27ms vs. 142±24ms; p=ns). While ERP reached baseline 30 minutes after cessation of rapid pacing in group 1 the ERP remained shorter in group2 (91±8%; p=0.054). There were no differences in blood pressure, mean atrial or ventricular rates between the two groups. Conclusions:Atrial remodeling is accentuated by elevated right atrial pressure despite complete autonomic blockade. Thus, increases mechanical stretch produced by elevated atrial pressure may be an additional factor which contributes to electrical remodeling during atrial fibrillation. Hohe atriale Depolarisationsfrequenzen bei Vorhofflimmern führen über einen verstärkten zellulären Kalziumeinstrom zu einer signifikanten Verkürzung der atrialen Refraktärzeit. Dieses atriale Remodeling scheint ein bedeutender Faktor zu sein, der zur Aufrechterhaltung des Vorhofflimmerns beiträgt. Das Ziel der vorliegenden Studie war es, zu untersuchen, ob unterschiedliche atriale Druckverhältnisse einen modulierenden Effekt auf das Entstehen und das Ausmaß des atrialen Remodeling besitzen und damit auch zur Entwicklung von Vorhofflimmern im Tiermodell beitragen. Methoden:Bei 10 Hunden (25±1kg) wurde während Inhalationsnarkose mit Isofluran der rechte Vorhof über einen quadripolaren Elektrodenkatheter für 7 Stunden mit 800bpm stimuliert. Komplette autonome Blockade wurde durch intravenöse Gabe von Atropin und Propranolol induziert und über den Versuchszeitraum konstant gehalten (Atropin: Bolus: 0,04mg/kg gefolgt von 0,007mg/kg/h und Propranolol: Bolus: 0,2mg/kg gefolgt von 0,04mg/kg/h). Die atriale effektive Refraktärzeit wurde stündlich bei einer Basiszykluslänge von 350ms über eine implantierte atriale Schrittmacherelektrode im rechten Herzohr bestimmt. Die Tiere wurden nach Abschluß der Versuchsreihe entsprechend dem mittleren atrialen Druckes im rechten Vorhof in zwei Gruppen eingeteilt. Der mittlere Vorhofdruck in Gruppe1 (n=5) betrug 4±0,2mmHg und der in Gruppe2 (n=5) 7±1mmHg (p<0,01). Ergebnisse:Bei allen Tieren kam es zu einer signifikanten Verkürzung der effektiven atrialen Refraktärzeit während hochfrequenter Stimulation. Die ERP verkürzte sich in Gruppe1 von 166±12ms auf 145±16ms (p<0,05) und in der Gruppe2 von 164±14ms auf 126±17ms (p<0,001). Die Verkürzung der effektiven Refraktärzeit war in Gruppe2 mit 23±5% signifikant größer als bei Tieren der Gruppe1 (13±5%; p<0,05). Die Dauer des induzierten Vorhofflimmerns war mit 59±22s in Gruppe2 ebenfalls signifikant gegenüber Gruppe1 (19±12s; p<0,05) verlängert. Die Zykluslänge des Vorhofflimmerns war nicht signifikant unterschiedlich (135±27ms in Gruppe1 versus 146±23ms in Gruppe2; p=ns). Während in Gruppe1 die Refraktärzeit 30 Minuten nach Beendigung der Stimulation den Ausgangswert erreicht hatte, war die effektive Refraktärzeit in der 2. Gruppe lediglich auf 91±8% des Basiswertes angestiegen (p=0,054). Zwischen den untersuchten Gruppen bestand kein Unterschied hinsichtlich der mittleren atrialen und ventrikulären Erregungsfrequenz bzw. des systemischen Blutdrucks. Schlußfolgerungen:Erhöhter Vorhofdruck scheint, auch unabhängig von einer möglichen vagalen Stimulation, ein zusätzlicher Faktor zu sein, der zu einer progressiven Verkürzung der atrialen effektiven Refraktärzeit während hochfrequenter atrialer Stimulation beiträgt. Es ist durchaus möglich, daß durch diesen Effekt das atriale elektrische Remodeling begünstigt und dadurch die Persistenz von Vorhofflimmern verlängert wird.

Since the mallet finger that is treated with isolated splinting of the distal interphalangeal (DIP) joint can be moved freely proximal to the DIP joint, we sought to determine whether such motion might cause a tendon gap that could explain the extensor lag that often follows treatment. Experiments were performed on 32 cadaveric fingers with open mallet finger lesions, immobilizing either the DIP joint alone or both the DIP and PIP joints, while repeatedly flexing and extending the more proximal finger and wrist joints. For each experiment, the gap in the extensor tendon was measured. Joint motion proximal to the DIP joint and retraction of the intrinsics did not cause a tendon gap in a finger with a mallet lesion, supporting the convention that only the DIP joint needs to be immobilized.

Since the mallet finger that is treated with isolated splinting of the distal interphalangeal (DIP) joint can be moved freely proximal to the DIP joint, we sought to determine whether such motion might cause a tendon gap that could explain the extensor lag that often follows treatment. Experiments were performed on 32 cadaveric fingers with open mallet finger lesions, immobilizing either the DIP joint alone or both the DIP and PIP joints, while repeatedly flexing and extending the more proximal finger and wrist joints. For each experiment, the gap in the extensor tendon was measured. Joint motion proximal to the DIP joint and retraction of the intrinsics did not cause a tendon gap in a finger with a mallet lesion, supporting the convention that only the DIP joint needs to be immobilized. Copyright 1999 The British Society for Surgery of the Hand

The elastin content of the chick thoracic aorta increases 2--3-fold during the first 3 weeks post-hatching. The deposition of elastin requires the covalent cross-linking of tropoelastin by means of lysine-derived cross-links. This process is sensitive to dietary copper intake, since copper serves as cofactor for lysyl oxidase, the enzyme that catalyses the oxidative deamination of the lysine residues involved in cross-link formation. Disruption of cross-linking alters tissue concentrations of both elastin and tropoelastin and results in a net decrease in aortic elastin content. Autoregulation of tropoelastin synthesis by changes in the pool sizes of elastin or tropoelastin has been suggested as a possible mechanism for the diminished aortic elastin content. Consequently, dietary copper deficiency was induced to study the effect of impaired elastin cross-link formation on tropoelastin synthesis. Elastin in aortae from copper-deficient chicks was only two-thirds to one-half the amount measured in copper-supplemented chicks, whereas copper-deficient concentrations of tropoelastin in aorta were at least 5-fold higher than normal. In spite of these changes, however, increased amounts of tropoelastin, copper deficiency and decreased amounts of elastin did not influence the amounts of functional elastin mRNA in aorta. Likewise, the production of tropoelastin in aorta explants was the same whether the explants were taken from copper-sufficient or -deficient birds. The lower accumulation of elastin in aorta from copper-deficient chicks appeared to be due to extracellular proteolysis, rather than to a decrease in the rate of synthesis. Electrophoresis of aorta extracts, followed by immunological detection of tropoelastin-derived products, indicated degradation products in aortae from copper-deficient birds. In extracts of aortae from copper-sufficient chicks, tropoelastin was not degraded and appeared to be incorporated into elastin without further proteolytic processing.

"Inhibin"-like protein, partially purified from the human prostate, was similar to that obtained from human seminal plasma under idential conditions. Concentration of inhibin in human prostate was tenfold higher as compared to human testis and was active biologically and immunologically. The presence of a high amount of inhibin in prostate seems to be unique in humans. Further inhibin concentration in benign prostatic hypertrophy tissue increased by tenfold in comparison to normal or cancerous tissue. Hence determination of serum level of inhibin may be used as a therapeutic tool to monitor prostate diseases.

The authors investigated the joint effects of diet and oral contraceptive use on ovarian cancer risk in 194 white women aged 65 years or less with epithelial ovarian cancer and 193 age- and residence-matched controls in Boston between 1984 and 1987 by using in-person interviews and self-administered food frequency questionnaires. Use of oral contraceptives for 3 months or more was associated with a modest protective effect for ovarian cancer (odds ratio (OR) = 0.7, 95 percent confidence interval (CI) 0.5-1.1). In women who consumed 11 g or less per day of lactose, use of oral contraceptives for 3 months or more was associated with a nonsignificant increased risk (OR = 1.6, 95 percent CI 0.8-3.2). In women who consumed more than 11 g per day of lactose, use of oral contraceptives for 3 months or more was associated with a substantially decreased risk of ovarian cancer (OR = 0.3, 95 percent CI 0.1-0.7). Within this group, the strongest association occurred with more than 4 years of total oral contraceptive use (OR = 0.2, 95 percent CI 0.1-0.6) and in those who had more than 2 years of oral contraceptive use after age 30 years (OR = 0.1, 95 percent CI 0.03-0.4). These results suggest that, with respect to ovarian cancer, lactose users may be the most likely to benefit from oral contraceptive use and that the benefit may be strongest when oral contraceptive use occurs after age 30 years.

When integrating the views of a large telecomunications application database at Bellcore, it was found that some pairs of view objects had significant structural similarities but differed semantically.+ This observation motivated the design of the structural integration methodology described in this article. Currently existing view and schema integration methodologies are based on semantic considerations. They allow integration only if two objects agree in their semantic and structural aspects. Structural integration permits the integration of objects even if they differ semantically. This article introduces structural integration for the case of full structural correspondence. We further develop an important special case, namely structural integration for classes with attribute partial correspondence. We use a subschema of the telecommunications application to demonstrate the applicability of structural integration to situations involving the complexities of real-world databases and applications. Algorithms for checking full structural correspondence of classes and databases are presented. Structural integration has several advantages, including the identification of shared common structures that are important for sharing of data and methods.

Finasteride (Proscar—an orally active 5α -reductase enzyme inhibitor) blocks the conversion of testosterone to dihydrotestosterone. The effects of finasteride in patients with benign prostatic hyperplasia were investigated in 2 double-blind, placebo-controlled studies. In study 1, 86 patients were treated with placebo or finasteride (5 to 80mg. per day) for 12 weeks, followed by a 12-week drug-free period. After 12 weeks of treatment all doses of finasteride showed significant decreases in prostate volume. However, 12 weeks after discontinuation of finasteride prostate volume returned to near baseline values. In study 2, 104 patients were treated with placebo or finasteride (0.2 to 40mg. per day) for 24 weeks. After 24 weeks of finasteride treatment prostate volume showed a mean decrease of 24% and 28% (p <0.01) in the 1 and 5mg. groups, respectively. Lower doses had a lesser effect on prostate shrinkage. Maximum urinary flow showed a mean increase of 3.7cc per second when the 1 and 5mg. groups were combined. Symptom improvement was observed in the 1 and 5mg. groups, although this was not statistically different from the placebo group due to the small sample size.

A 67year-old man with known coronary artery disease presented with an episode of wide QRS tachycardia with left bundle branch block (LBBB) morphology associated with dyspnea, angina and near syncope which terminated spontaneously on arrival in the emergency room. The differential diagnosis consisted of (1) ventricular tachycardia or (2) supraventricular tachycardia with either aberrant conduction or anterograde conduction via an accessory connection. During invasive electrophysiologic testing, programmed ventricular stimulation reproducibly induced the clinical tachycardia with LBBB morphology and a cycle length of 342ms. Retrograde conduction via a concealed left-sided accessory connection was confirmed. During tachycardia, sensed ventricular extrastimulation induced a sudden increase in tachycardia cycle length associated with loss of LBBB. This (paradoxical) increase in tachycardia cycle length with loss of ipsilateral bundle branch block during orthodromic AV reentrant tachycardia was due to the additional presence of dual AV node physiology and switch from anterograde fast to anterograde slow pathway conduction. The LBBB was most likely due to the ’linking phenomenon‘ which was interrupted by the right ventricular extrastimulus. The accessory connection was successfully ablated within the proximal coronary sinus, and typical or atypical AV node reentry could not be induced. Thus, slow pathway ablation was not performed. Ein 67jähriger Patient mit rezidivierender Tachykardie mit Linksschenkelblock (LSB-artig) konfiguriertem Kammerkomplex wird beschrieben. Die Differentialdiagnose umfaßte (1) ventrikuläre Tachykardie und (2) supraventrikuläre Tachykardie mit Aberration oder antegrader Leitung über eine akzessorische Leitungsbahn. Während der invasiven elektrophysiologischen Untersuchung konnte mittels programmierter ventrikulärer Stimulation die klinische Tachykardie (LSB, Zykluslänge 342ms) reproduzierbar ausgelöst werden. Dabei erfolgte die retrograde Leitung über eine verborgene (nur retrograd leitende) akzessorische Leitungsbahn. Bei ventrikulärer Extrastimulation während der Tachykardie wurde eine Zunahme der Tachykardie-Zykluslänge auf 390ms und gleichzeitig eine Normalisierung der QRS-Komplexes beobachtet. Die (paradoxe) Zunahme der Zykluslänge bei Verlust eines ipsilateralen Schenkelblocks während orthodromer AV-Reentry-Tachykardie beruhte in diesem Falle auf dem zusätzlichen Vorliegen einer dualen AV-Knoten-Physiologie mit Wechsel der antegraden Leitung während der Tachykardie vom schnellen zum langsamen AV-Knoten Leitungsweg. Es wurde eine erfolgreiche Hochfrequenzstrom-Ablation der akzessorischen Bahn innerhalb des Coronarvenensinus durchgeführt. Typische oder atypische AV-Knoten Reentry ließ sich nicht auslösen, so daß ein Ablationsversuch des AV-Knoten Slow Pathways nicht unternommen wurde.

Diffraction arid partial coherence cause errors in the measurement of small-scale photographic detail by microdensitometers and projection systems. The optical imaging nonlinearities can be avoided by scanning the silver distribution with a narrow beam of energetic electrons and counting the secondary quanta that are excited. It is found that the number of low energy (secondary) and high energy (backscattered) electrons emitted from various emulsion types as well as the characteristic Ag x-ray fluorescence are measures of the local silver concentration. A mechanism for the secondary electron contrast, which is only in part due to surface relief, is proposed. Spatial frequencies up to 2280 p/mm have been retrieved by such scanning electron beam probes.

We compared the effect of a variety of drug regiments to lower prostate DHT concentration. Patients with BPH were treated for one week prior to surgery with either tamoxifen, flutamide, megestrol acetate, megestrol acetate plus tamoxifen and megestrol acetate plus DES or ketoconazole. DHT concentration in the surgically resected tissue was compared with tissue obtained from untreated patients. We also obtained prostate tissue at the time of relapse in patients with prostate cancer who had been treated with orchiectomy with or without estrogen therapy. Megestrol acetate plus the mini-dose of DES (0.1 mg) and megestrol acetate plus ketoconazole both decreased DHT concentrations in prostate tissue to levels (0.79 ng/g) significantly below those noted with orchiectomy (1.16 ng/g). The difference between the DHT concentration in the two groups (orchiectomy vs. total androgen blockade) represents the contribution of adrenal androgens to prostate tissue DHT. This small amount of DHT (approximately 0.4 ng/g) may be biologically important in stimulating prostate epithelial cell growth.

Instantane und zirkadiane HRV können bei Patienten mit IDC, auch in Gegenwart einer hohen VES-Dichte, mittels LPA verläßlich bestimmt werden und, im Gegensatz zu SDNN und sNN50, als Marker der linksventrikulären Pumpfunktion bei der Risikostratifikation verwendet werden.

We have been studying the endocrine system of elderly men with prostatic disorders, none of whom had any clinical or routine laboratory evidence of an endocrine disorder. The presence of prostate disease, so common in males over 60, may be an incidental finding, since we do not have data in age-matched controls. In 8 patients studied to date, 4 with prostate carcinoma and 4 with benign prostatic hypertrophy, decreased or absent pituitary luteinizing hormone (LH) reserve has been uniformly noted. No other abnormalities of pituitary function have been noted except that two patients had increased 24-h urinary total pituitary gonadotrophins, probably indicating primary testicular failure. Investigations included studies of growth hormone (GH) reserve by measurement of plasma GH levels following arginine stimulation (Merimee & Rabinowitz, 1969). Although 4 patients had Stage IV carcinoma of the prostate, none was cachectic and body weight in this group ranged from 2·5 to 16

Objective: In the clinical setting, the response of adult and neonatal cardiac rhythms to hypoxia and to acidosis differs, the former leading to tachyarrhythmias and the latter to bradyarrhythmias. In this study, the aim was to determine whether a cellular electrophysiological substrate could be identified to explain the clinical observation. Methods: Conventional microelectrode techniques were used to study the electrophysiological responses of automatic Purkinje fibres to acidosis, hypoxia, and hyperkalaemia individually. Results: Adult Purkinje fibres showed decreases in maximum diastolic potential, activation voltage, and automaticity as pH was decreased from 7.3 to 6.1. Triggered activity due to early afterdepolarisations developed in 70% of adult Purkinje fibres at pH 6.1. Neonatal Purkinje fibres showed decreased automaticity as pH decreased and, in contrast to adults, quiescence occurred at pH 6.1 At Po₂ <2.9 kPa automaticity decreased significantly in adult Purkinje fibres, whereas neonatal fibres were unaffected. The effect of raising [K+]_o was comparable at both ages. Conclusions: The response to acidosis and to hypoxia differs significantly between neonatal and adult Purkinje fibres and may explain some developmental differences in the expression of cardiac arrhythmias. Cardiovascular Research 1994;28:125-128

The determinants of atrioventricular (AV) nodal “slow pathway” conduction remain controversial. We hypothesized that anterograde “slow pathway” conduction time depends on the length (rather than functional properties) of the pathway. Therefore, we studied 19 patients (4 men and 15 women, mean age 51±4 years) with typical AV nodal reentrant tachycardia (AVNRT) who underwent successful radiofrequency ablation (RFA) of the “slow pathway”. As a measure of the pathway length we determined two distances in both RAO and LAO projections: I) coronary sinus (CS) os to the His bundle and 2) mapping catheter tip at the successful ablation site to the His bundle. These distances were correlated with the conduction time of the “slow pathway” (AH interval) during programmed atrial stimulation following coupling intervals longer than the functional “slow pathway” refractory period and during AVNRT. RFA was initially attempted in the posteroseptal area of the right atrium close to the CS os and was delivered at progressively superior and anterior locations (closer to the compact AV node) only when inferior RFA applications were unsuccessful.