Search

A novel 1-h topical method eradicated Helicobacter pylori in 96% of dyspeptic patients. The eradication rate of amoxycillin/omeprazole therapy varies from 0 to 93%.To compare both methods in patients with endoscopically proven duodenal ulcer.Eighty patients (59 males, 21 females; median age 43 years) were randomized into two therapeutic groups. The first group (group A) was treated with a 6-week course of ranitidine 300 mg/day, then omeprazole 20 mg b.d. with pronase 36000 units/day for 2 days, followed by 1-h topical therapy with a solution of bismuth, metronidazole, amoxycillin and pronase. The second group (group B) consisted of patients treated with omeprazole 20 mg b.d. and amoxycillin 2 g/day for 2 weeks, followed by a 4-week course of ranitidine 300 mg/day. Eradication of H. pylori was assessed by urease test, histology, a polymerase chain reaction and a 13C-urea breath test, all of which were performed 4 weeks after discontinuation of the antibacterial treatment.Eradication rates in groups A and B were 2.5% and 35% in an intention-to-treat analysis, respectively. Side-effects were encountered in 40.5% and 12.5% of subjects in groups A and B, respectively. Treatment tolerance was rated as poor by 54% of patients in group A and 2.5% of patients in group B.Both treatment regimens, the 1-h topical method and amoxycillin with omeprazole, have low eradication rates in patients with duodenal ulcer. In addition, the topical treatment is characterized by a high rate of side-effects and poor tolerance. Based on the results of our study, neither method can be recommended for eradication of H. pylori in patients with duodenal ulcer.

With the first generation of implantable left ventricular assist devices intended for semi-permanent or permanent use, clinical experiences have been gathered worldwide during the last 8 to 10 years. The development phase of these devices started in the early 1970’s, it took 15–20 years until initial clinical applications.

The institution of extracorporeal circulatory support in the pediatric population has been limited due to the scarcity of suitable devices. Although the successful use of miniaturized intra-aortic balloon pumps in children has been reported occasionally (23, 34), providing intra-aortic balloon pump support in this cohort has been hampered by difficulties associated with inserting cannulas into small vessels and synchronizing the device to a rapid heart rate. Its efficacy has further been questioned in small children because of increased aortic compliance. Over the last decade circulatory support in pediatric surgery has most commonly been provided through extracorporeal membrane oxygenation (ECMO)(14, 17, 25, 36). The capability of ECMO to provide biventricular as well as respiratory support may be beneficial in maintaining circulation in children, especially those with congenital heart defects. Some recent reports have described the successful use of a centrifugal ventricular assist device (VAD) in children for cardiogenic shock after cardiac surgery (6, 15), for donor heart failure, and as a bridge to cardiac transplantation (26). However, the impossibility of mobilizing the patient, generating a pulseless flow, and the short durability of the components are critical disadvantages for long-term support with ECMO or centrifugal VADs.

Over the last 10 years more than 1000 intrathoracic transplant procedures have been performed at the German Heart Institute Berlin, 840 of which were orthotopic heart transplantations. From early on, it became apparent that medical treatment alone would not be sufficient for supporting patients through an ever-expanding waiting period before transplantation (1, 2, 3, 5–7).

A 2.5-cm-long middiaphyseal plate-stabilized segmental defect in the right femora of 5 adult sheep was implanted with 1.5 mg of recombinant human bone morphogenetic protein 2 mixed with inactivated demineralized ovine bone matrix. Bone healing was evaluated for 12 months using clinical, radiographic, gross pathologic, and histologic techniques. Bone formation within the defect was first visible radiographically between Weeks 2 and 4 after surgery; bone union was apparent between Weeks 12 and 16, at which time the plates were removed. Recanalization of the medullary cavity with neocortex formation was near completion at Week 52. Bone mineral content at the defect sites equaled that of the nonsurgically treated intact femora by Week 16. Perifemoral soft tissue mineralization did not occur, and callus size was not greater than that formed with autograft. By Week 52, the sheep were not lame, and at necropsy the surgically treated femora were rigidly healed. Woven and lamellar bone bridged the defect site. An apparently normal sequence of ossification, modeling, and remodeling events had occurred. Recombinant human bone morphogenetic protein 2 mixed with a suitable carrier could provide an alternative to autograft for use in a variety of orthopaedic procedures.

In recent years, comparative sport shoe tests have resulted in an improvement of athletic footwear quality. Examples demonstrate the value and the limits of material tests, biomechanical investigations and subjective wear test evaluations. Biomechanical experiments have the primary goal to analyse sports shoe function with regard to shoe properties to prevent injuries. Rear foot pronation and supination measurements, in-shoe pressure distribution analyses, and the registration of ground reaction forces as well as tibial accelerations are valuable in the process of biomechanical evaluation. Material tests can be used to determine production quality between shoes and midsole material deterioration in used shoes. Wear tests with subjective evaluation are necessary for the judgement of shoe properties (e.g., shoe fit) which cannot be measured by biomechanical or material test methods.

A middiaphyseal, 2.5-cm osteoperiosteal segmental defect stabilized by plate fixation was created in the right femur of 17 sheep. Four treatment groups were included: Group I, no implant; Group II, inactive bone matrix; Group III, recombinant human bone morphogenetic protein (rhBMP-2) mixed with inactive bone matrix; and Group IV, autogeneic bone graft. Three animals had early failure of fixation, and the remaining 14 were evaluated at three months after implantation. Radiographs showed bony union of all defects treated with rhBMP-2 (six) and a lack of bony union in the negative-control groups treated with no implant (three) and inactive bone matrix without BMP (three). Both defects treated with autograft healed. New bone formation in the defect sites treated with rhBMP-2 first appeared one month after implantation and had a mean bending strength (expressed as a percentage of the contralateral femur) of 91% +/- 59% (mean +/- standard deviation) for defects treated with BMP-2, 77% +/- 34% for autograft, 9% +/- 8% for no implant, and 11% +/- 7% for inactive matrix without BMP. Three sheep treated with rhBMP-2 had their fixation plates removed at four months and were followed for one year. Their bone defect sites remained solidly healed one year after the initial operation.

Zur prognostischen Beurteilung infragenualer Bypass-Verfahren wurden bisher morphologische Scores verwendet und enttauschten zunehmend. Deshalb wurde fur die genaue Bestimmung des Abfluswiderstandes, eines funktionellen Parameters, eine einfache Methode entwickelt, um eine prognostische Aussage uber die Bypassfunktion geben zu konnen. Die ersten Ergebnisse an 45 Patienten mit 52 Widerstandsmessungen zeigten, das bei hohen Widerstandswerten (> 1,1 mmHg × min/ml) ein By-pass-Sofort-bzw.-Fruhverschlus absehbar war.

Heart transplantation has become a routine procedure. Surgical techniques have been standardized and triple-drug immunosuppression has proven to be the most effective posttransplantation medical treatment. A shortage of donor organs has remained the major factor inhibiting extensive application of heart transplantation. Improved techniques of organ protection may eventually contribute to an extension of the donor pool. However, it seems to be more important to develop alternative procedures further (artificial heart, xenotransplantation, extended use of conservative surgical or medical treatment). The patient population undergoing heart transplantation will undoubtedly include more older, severely ill, polymorbid patients who are not suitable for alternative procedures. Pediatric heart transplantation may increase in the coming years and mechanical circulatory support will surely gain in importance for both adult and pediatric patients awaiting heart transplantation.

Mechanical circulatory support systems are currently in clinical use to keep patients alive with the aim of either cardiac recovery after open heart surgery, myocardial infarction and after heart transplantation with acute graft failure, or as a bridge to transplantation in heart transplant candidates. At the German Heart Institute the "Berlin Heart" mechanical circulatory support system has been used invariably since 1987. Up to 1991 there were 22 patients in the "recovery" group. Four patients could be weaned from the system, but only one patient was discharged from the hospital. In 65 patients mechanical circulatory support systems were implanted as a bridge to transplantation, 39 patients had transplants, and 22 patients left the hospital. Risk factor analysis in the bridging group revealed that previous heart surgery, infective pneumonia, shock-related coagulation disorders, and an age greater than 50 years had an unfavorable influence on patient survival. It is concluded that patients may be kept alive for weeks and months after any kind of cardiogenic shock. Complete cardiac recovery may be achieved in the case of early posttransplant graft failure. Reliable prediction of outcome in the bridge to transplantation group requires further experience.

After reconstructive vascular surgery the quality of perfusion and the risk of failure can be predicted, if the distal outflow resistance of the graft is known. The laws of the hydrodynamics for the calculation of flow resistance in tubes are discussed with respect to their validity in the circulatory system. Because of great differences between the physiological realities and the physical assumption, and problems in monitoring some of the parameters of the equations, the calculation of the physiological vascular resistance according to the a.m. laws is not possible. With "Ohms law" of the hydrodynamic the calculation of the outflow resistance distal of a graft is possible if the flow through the bypass and the pressure losses in the outflow bed are known. Easier to perform is the measurement of the pressure-time integral generated by the injection of a standardized volume into the graft and the calculation of the outflow resistance with the help of a microprocessor.

Between February 1989 and June 1991 the peripheral outflow resistance was measured at 45 patients during infragenual bypass surgery. In order to find out whether there is a correlation between successful bypass grafting and measured outflow resistance, all patients were controlled regularly. There was a significant difference in mean resistance between those grafts remaining patent and those that failed. 8 out of 11 bypasses, that failed up to one month after operation, had measured peripheral resistance higher than 1.1 mmHg x min/ml. 12 out of 15 bypass grafts remained patent for more than one month and had an outflow resistance less than 0.55 mmHg x min/ml. There is no definite correlation between a measured outflow resistance from 0.55 to 1.1 mmHg x min/ml because of the low number of patients in this group. The purpose of resistance measurement during peripheral vascular surgery was to determine a final value for a decision, if additional surgical or non surgical treatment for a better runoff is necessary. In our study this value is 1.1 mmHg x min/ml. Additional treatments are the peripheral AV-fistula and a jump- or sequential-graft. Another possibility is the intra- and postoperative application of Prostaglandin, which is in an experimental study in our clinic.

The measurement of the vascular outflow resistance during reconstructive vascular operations was applied since 1989 on 45 subjects with reliable results. This measurement is an aid for decision of additional treatment increasing the outflow, like a jump- or sequential bypass or a pharmacological therapy. The principle of measurement is based on the injection of a known volume of saline in the vessel and the integration of the intravascular pressure during this injection. In the prototype used, the pressure integration was performed by means of a modified analog/digital conversion method, hereby the results could be achieved directly as numerical values. Further an automatic, microcomputer based implementation of the outflow resistance measurement, showed remarkable improvements of accuracy in laboratory tests.

Branchial cleft cyst was diagnosed in a 6-month-old Angus bull with a large swelling in the distal ventral neck region. A definitive diagnosis could not be attained from results of the clinical examination, radiography, and ultrasonography. Diagnosis was made from histologic examination of the surgically removed mass. Branchial cleft cysts are remnants of the branchial apparatus and are considered rare in domestic animals. The differential diagnosis should include the thymic form of bovine viral leukosis, thymoma, abscess, goiter, and thyroid gland tumors as well as other rare cysts that can develop in the same location.

Between 7/87 and 9/90 thirty-four patients underwent total artificial heart (Berlin Heart) (n = 2) or biventricular assist device (Berlin Heart) (n = 32) implantation as a bridge to cardiac transplantation. The time of mechanical support ranged from 2 to 60 days, for a mean of 19.2 days. Twenty-three patients received heart transplants, with 74% 30-day survival and 52% long-term survival. Implantation of a mechanical support system became indicated in those patients whose hemodynamic and clinical condition deteriorated despite treatment with enoximone in addition to maximal sympathomimetic medication. The strategy to administer enoximone routinely was the result of a prospective study on 24 pretransplant patients in whom enoximone therapy reduced the need for mechanical assistance by 62%. At the time of device implantation shock-related organ impairment such as cerebral, renal, hepatic, and respiratory dysfunction was present in 62% of patients. In addition, 7 patients had pneumonia. During mechanical support complete recovery of end-organ failure and resolution of pneumonia was observed in the majority of patients. The results indicate that end-organ dysfunction per se should not be considered a contraindication to mechanical circulatory support as a bridge to cardiac transplantation. However, further clinical investigations are needed to identify predictive indicators of irreversible organ damage.

Die rekonstruktive krurale Arterienchirurgie leidet immer noch in einem hohen Prozentsatz an Miserfolgen. Ursache ist der schlechte periphere Abflus, der bedingt ist durch einen hohen Abfluswiderstand bei meist multiplen Unterschenkelarterienverschlussen. Die Prognose infragenualer Rekonstruktionen hangt daher weit weniger von der Gefasmorphologie als vielmehr vom Abfluswiderstand ab.

A piezoelectric pressure distribution platform (1000 elements) was employed, to investigate the mechanical behavior of three different foot structures. Ten male subjects in each of the foot groups Cavus, Rectus, and Planus performed voluntarily controlled jumps with one leg onto the pressure distribution platform. Using a trap door arrangement, the subjects fell in a second set of experiments unexpectedly onto the sensor matrix. In order to exclude a voluntary foot muscle response, the time duration of falling was restricted by choosing a falling height of only 20 cm. Comparing the data from both impact conditions the influence of active foot muscle involvement could be investigated. The analysis of the temporal pressure pattern, the local peak pressures and the regional impulses permitted an insight into the mechanical characteristics of the different foot structures.

The Berlin Artificial Heart System/Biventricular Assist Device (BVAD) was used in 38 patients. 1) Twenty-eight patients were awaiting cardiac transplantation (Tx) (age 23-56 yrs). All patients had contraindications not allowing immediate Tx. 2) Five patients were emergency cases not on our Tx list (postcardiotomy cardiac failure, acute myocarditis) (age 28-59). 3) Five patients were post Tx patients with graft failure (age 22-52). Extracorporal circulation was used for implantation of the BVAD. In group 1, 21 of 28 patients (pts) recovered, and all were subsequently transplanted after 6 hours to 39 days, when all organ function was restored. In 7 pts, mechanical circulation was terminated after 1-40 days because of further deterioration. Five of the transplanted pts died, 14 pts survived (greater than 30 days), and 2 pts were just transplanted with satisfactory postoperative courses. Of group 2 and 3 pts, two were successfully weaned. In one patient the allograft recovered after 11 days of support.

In total artificial heart replacement the pumps are attached to the vascular system with the help of connectors. These consist of a woven Dacron vessel graft to which a short silastic segment is vulcanized. In 36 calves surviving total artificial heart replacement between one and seven months (average 85 days) the morphological alterations due to interfacial reactions were studied: thrombus formation and neointimal fibrous hyperplasia at the anastomoses. In 15 calves (41.7%) thrombus growth within the outflow tract led to anastomotic stenosis: pulmonary artery 14 (93.3%), aorta-anastomosis 1 (2.8%), both vessels 1 (2.8%), in combination with pannus growth in atrial location 13 (86.7%). In 73.3% the pannus consisted of infected organized thrombus imitating the course of septic vegetative endocarditis. Two calves were reoperated in order to remove the vegetative thrombi, one successfully. In five animals pulmonary stenosis was the main cause of death. The presence and location of excessive tissue growth and thrombus formation within the outflow tract are also inherent to the fluid mechanical design of the valve. Neointimal fibrous hyperplasia at the anastomoses of the grafts seems to be a reparative process started up by platelet-induced subendothelial cell proliferation in response to intimal injuries.

Six polyurethanes (PUs) were tested with respect to their cytocompatibility. Initial adhesion, initial spreading, and the proliferation of endothelial cells were investigated. All smooth PUs showed similar initial adhesion. Initial spreading was faster on rough PUs. Collagen coating resulted in faster initial adhesion but not better proliferation of endothelial cells.

The electrophysiological mechanisms underlying supraventricular dysrhythmias that accompany acute myocardial infarction were studied in rabbits subjected to ligation of right coronary artery. In vivo, sinus bradycardia, atrioventricular block and rapid atrial arrhythmias were observed 2 to 5 hours after coronary occlusion; evidence of ventricular arrhythmias was absent. The bradyarrhythmias were markedly improved after iv administration of atropine. The infarcted hearts were then removed and the isolated sinoatrial (SA) node, right atrium and atrioventricular (AV) node were studied with intracellular microelectrodes in vitro. Rapid, repetitive atrial depolarizations occurring spontaneously or initiated by premature atrial stimulation were observed only in preparations obtained from infarcted hearts. In disseminated areas localized within the SA node and the atrium, the subendocardial fibers had a reduced action potential amplitude but showed also normal potentials in other regions as compared with noninfarcted preparations. Sinus rate, poststimulatory sinus-node recovery time, intraatrial conduction and the parameters of AV nodal function including action potential amplitude and conduction were not significantly different in preparations isolated from infarcted and noninfarcted hearts. The results suggest that the observed bradyarrhythmias accompanying acute myocardial infarction may be partly due to a vagomimetic reflex whereas the supraventricular tachycardias seem to result from direct cellular damage.

Die Untersuchungen der Entwicklung der Erythrocytenvolumina bei heranwachsenden Kalbern zeigen bei Milchmastkalbern die Entwicklung einer Eisenmangelanamie, die im Normalfall bis zum Zeitpunkt der Schlachtreife fortschreitet. Bei rechtzeitiger gezielter und uberwachter Futterumstellung ist es moglich, die fur Implantationsversuche eines kunstlichen Herzens bestgeeigneten Versuchskalber jahreszeitunabhangig heranzuziehen. Die Umstellung mus im fruhen Alter (14 bis 21 Tage), in dem die Tiere noch ausreichend durch das fotale Eisendepot versorgt sind, erfolgen. Anzustreben sind Versuchstiere mit folgenden Werten: Bei der Verwendung derartiger Rauhfutterkalber zeigten sich erhebliche Vorteile auf den Gebieten: Hamatologie, Hamodynamik — Kreislaufregulation, operative Technik, Raumbedarf der Blutpumpen — Herzzeitvolumen.

A nonlinear dynamic mathematical model of the cardiovascular system is outlined, which is employable to analyse the hemodynamic system behaviour under normal as well as under pathological conditions. By modifying this model, assuming that cardiac output is constant at a preset level (which is in accordance with most of the total artificial heart systems, since their pumps output is preselected with fixed driving parameters), the hemodynamic behaviour of a circulation system with an artificial heart was simulated. Comparing the simulation results with those obtained from total artificial heart experiments, a good agreement in right atrial and aortic pressure under exercise conditions could be proven. Furthermore, the modified and tested cardiovascular system model can be used as a tool for evaluation of optimal control parameters under given conditions, by quantitatively analysing the artificial heart connected with the vascular system.

An Ammoniten, Sauriern, Fischen, Pflanzen wird dargelegt, das das „Typische” von Neuerscheinungen nicht erst mit ihnen auf den Plan tritt, sondern als Erbe schon in der „phyletischen Muttergeneration” angelegt wird. Auch in absterbenden Zweigen wirkt sich gleiches Erbgut aus. Die Behandlung im System ist bei verschiedenen Abteilungen nicht logisch gleichmasig gehandhabt: die Palaontologie hat Anlas und den Vorzug, die zeitlichen Zasuren zu berucksichtigen und gleichsam ein 2-dimensionales System zu einem 3-dimensionalen auszubauen.