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Biomedical subjects

G Faust

Publications and source records attributed to G Faust.

At least 19 recordsLinked to original sources

Finite element analysis of a bone-implant system with the proximal femur nail.

Static analysis with finite element of a realistic femur nail bone-implant system in a typical proximal femoral fracture under physiological load bearing situations provides results for stress, displacement and strain. The question to be answered is, if simulation with the finite element analysis is able to explain biomechanically clinical observed patterns of failure. Surface-Reconstruction with CT database of a proximal femur and reconstruction with CT based density data was done. Next steps were to unite the bone structure with the Proximal Femoral Nail and to model two relevant fractures (31-A2.2 and A2.3 according AO). After modelling of geometry, isotropic material behaviour and load application numeric calculation of the femur-nail system with FE-software was performed. FE simulation mainly shows an axial dislocation of the femoral head screw with nearly no dislocation of the antirotation screw. This so-called z-effect therefore means: (1) Tilting of the proximal main fragment around the sagittal axis between the screws and (2) relative movement of both screws in the frontal plane. Relative movement of the two screws against each other could be the reason for implant failure, the so called cut out. Furthermore simulation shows different gliding of the screws explaining the so called z-telescoping. The analyzed stress patterns have to be relativized, because isotropic material behaviour of cancellous bone was assumed. Further examinations for this issue are necessary.

Biomechanical Phenomena↗

[Dying through the hand of man or taken by the hand of man? Results of an opinion poll concerning active euthanasia and the Hospice Movement].

BACKGROUND: Opinion polls show a growing support of active euthanasia in Germany. The hospice movement rejects active euthanasia and pleads for a qualified care for the dying. The aim of our study was to evaluate how far the work and the ideas of the hospice movement are known in Germany and to which extend this knowledge influences the attitude towards active euthanasia. METHODS: An interview of 200 people in the pedestrian area of Mainz was undertaken. RESULTS: 73% of all interviewees supported active euthanasia. Significant predictors for opposition to active euthanasia were increasing age and belonging to the roman catholic confession. However, 72% of active euthanasia supporters did not know what a hospice is, and 80% were not aware of the existence of such an establishment in Mainz. Opponents of euthanasia had significantly more knowledge of these items. CONCLUSION: The results of our study indicate that physicians should wherever possible explain the aims and the work of the hospice movement who should be their ally in a qualified commitment for the dying. It can be expected that the hospice movement will find a lot of sympathy in the population as 2 of its major aims--openness in communication and dying at home wherever possible--were shared by the vast majority of all interviewees: in case of incurable disease 92% wanted to be informed on their diagnosis, and 84% wanted to die at home or in their families home.

Euthanasia↗

Warfarin anticoagulation in the perioperative period: is it safe?

This study was undertaken to determine if warfarin anticoagulation could be safely continued during surgery and in the perioperative period. An animal model was followed by a prospective human study of all patients on heparin or warfarin at the time of surgery. Twenty-four rabbits underwent laparotomy, during which a controlled liver injury was created and repaired. Group 1 (Warf) was anticoagulated with warfarin to raise the mean international normalization ratio (INR) to 2.5-3.0. Group 2 (Hep) was anticoagulated with heparin to raise the activated partial thromboplastin time to 1.5-2.0 times control. The heparin was then stopped 6 hr prior to surgery and resumed 6 hr postoperatively without a bolus. Group 3 (control) was not anticoagulated and received saline infusion. For the human study, data were collected on 40 patients undergoing 50 operations from October 1996 to January 1998. The results of this study reveal that (1) bleeding was less in the group anticoagulated with warfarin throughout surgery in the animal model, (2) bleeding complications were less in the patients continued on warfarin through surgery than those on heparin (3) older patients may have an increased risk of bleeding, and (4) an INR of >3 at the time of surgery may increase the risk of bleeding.

Animals↗

Minimal incision abdominal aortic aneurysm repair.

PURPOSE: The use of a limited incision for abdominal aortic aneurysm (AAA) repair was evaluated, and its outcome was analyzed in comparison to laparoscopic-assisted and standard open repair. METHODS: Eleven patients who had an AAA that required a tube graft underwent minimal incision (MINI) repair. The procedure consisted of a standard endoaneurysmorrhaphy performed through an 8- to 10-cm minilaparotomy. Clinical characteristics, in-hospital outcomes, and total in-hospital charges for this procedure were then compared with those of comparative groups of patients who had undergone repair of AAA by means of a laparoscopic-assisted (LAP) approach or a standard open (OPEN) technique. RESULTS: MINI repair was successfully completed in all 11 patients. Patients in the three groups were comparable for age, sex, risk factors, and aortic dimensions. The mean values for operative time, blood loss, length of hospital stay, and total hospital charges for the three comparison groups were: 129. 7 minutes (MINI) vs. 244.8 minutes (LAP)*, 209.9 minutes (OPEN)*; 522.7 mL (MINI) vs. 1214.7 mL (LAP), 1795.8 mL (OPEN)*; 5.18 days (MINI) vs. 18.7 days (LAP), 17.4 days (OPEN); $22,692 (MINI) vs. $59, 922 (LAP)*, $62,324 (OPEN)* (*P <.05). Local complications occurred in 18.2% of patients who underwent MINI repair, 23.5% of patients who underwent LAP repair, and 29.7% of patients who underwent OPEN repair (P = not significant). Patients undergoing minilaparotomy demonstrated decreased compromise of gastrointestinal function, with a decreased need for postoperative fluid resuscitation (6799.7 mL [MINI], 7781.8 mL [LAP] vs. 11061.1 mL [OPEN]*) and shortened nasogastric tube decompression (1.6 days [MINI], 1.5 days [LAP] vs. 4.1 days [OPEN]*; *P <.05). CONCLUSION: MINI repair is a technically feasible technique that combines the benefits of minimally invasive surgery with those of conventional open repair with few, if any disadvantages. Facility of the procedure, combined with the potential cost benefits, encourages further study for consideration of this technique as a viable alternative for the management of AAAs.

Aged↗

[Quality management in the hospital].

Quality management in hospitals is a much discussed topic. However, mainly theorists take the floor, who have some good advice, but rarely have practical experience. All those theorists have been heard by the responsible person of the Fritz-König-hospital in Bad Harzburg, as well. At the end, however, an own system of quality management was developed with the aid of an external expert. This article describes the step-by-step introduction of quality management and the related experiences.

Documentation↗

Valsartan, a new angiotensin II antagonist for the treatment of essential hypertension: efficacy and safety compared to hydrochlorothiazide.

OBJECTIVE: To compare the antihypertensive efficacy of a new angiotensin II antagonist, valsartan, with a reference therapy, hydrochlorothiazide (HCTZ). METHODS: In this double-blind study, 167 adult out-patients with mild-to-moderate essential hypertension were randomly allocated in equal number to receive valsartan 80 mg or HCTZ 25 mg for 12 weeks. In patients whose blood pressure (BP) remained uncontrolled after 8 weeks of monotherapy, atenolol 50 mg was added to the initial treatment. Patients were assessed at 4, 8 and 12 weeks. The primary efficacy variable was change from baseline in mean sitting diastolic BP (SDBP) at 8 weeks. Secondary variables included change in sitting systolic BP (SSBP) and responder rates (percentage of patients with SDBP < 90 mmHg or drop > or = 10 mmHg compared to baseline) at 8 weeks. RESULTS: Valsartan and HCTZ were both effective at lowering diastolic and systolic blood pressure at all time points. Similar falls were seen in both groups with no significant differences between treatments. For the primary variable (decrease in SDBP) there was no significant difference between treatments. For SSBP there was also no significant difference observed. Responder rates at 8 weeks were 74% for valsartan and 62% for HCTZ (P = 0.10). Both treatments were well tolerated, both as monotherapy, and when combined with atenolol 50 mg per day. CONCLUSION: The data show valsartan 80 mg to be as effective as HCTZ in the treatment of mild-to-moderate hypertension. The results also show valsartan to be well tolerated when taken alone or in combination with atenolol.

Adolescent↗

Brief depression among patients in general practice. Prevalence and variation by recurrence and severity.

Depression with substantial psychosocial impairment, but not qualifying as depressive disorder according to the standard diagnostic manuals, is frequent among primary care patients. Recurrent brief depression (RBD) is a diagnostic category intended to identify a major proportion of this group of patients. The WHO study on "Psychological Problems in Primary Health Care" was used as a vehicle to estimate the proportion of patients with this diagnosis and to evaluate the validity of this diagnosis as well as of alternative concepts of brief depression with multiple episodes. This study applies a two-stage sampling scheme; 300 patients also underwent an additional interview tailored for variants of brief depression. 7.6% of primary care patients were identified as RBD with the majority not receiving any other psychiatric diagnosis (DSM-III-R). These patients reported substantial psychosocial impairment, and the majority were identified as psychological cases by general practitioners. However, patients experiencing other variants of brief episodes were also found to be substantially psychosocially impaired, although they were not identified as psychiatric cases by DSM-III-R. Thus, a less restrictive definition of RBD is proposed. The diagnostic definition of RBD has a major impact on the sex ratio of cases: the less restrictive the diagnosis, the more balanced are the prevalence rates between males and females.

Adolescent↗

[A one year study of single administration of nilvadipine. Results of the effectiveness and long-term tolerance in hypertension].

AIM: To test the efficacy and long-term tolerability of a single daily dose of nilvadipine. STUDY DESIGN: Open, multicenter follow-up study of 8-months duration following a 4-month randomized double-blind preliminary study (vs. nifedipine). PATIENTS: 307 ambulatory hypertensives with a diastolic blood pressure of < or = 95 mm Hg at the end of the preliminary study. MEDICATION: One capsule of nilvadipine retard 8 or 16 mg taken once a day (in the morning). PARAMETERS: Monthly recording of blood pressure, pulse rate and body weight, and any adverse reactions: global assessment by the physician of tolerability and efficacy in month 12; in addition, ECG and laboratory parameters in months 6, 9 and 12. RESULTS: In more than 95% of the patients, nilvadipine reduced blood pressure to normal levels. Some 95% of the physicians investigated assessed efficacy and tolerability to be "good" to "very good". The direct changeover of medication from nifedipine t.i.d. to a single daily dose of nilvadipine presented no problems.

Aged↗

Loads on muscles, tendons and bones in the hind extremities of sheep--a theoretical study.

Muscle forces and bending moments were calculated with a two-dimensional non-linear force and moment analysis (according to the Finite Element Method) during the foot-lowering phase, stance phase and stem phase in the hind legs of sheep. During the foot-lowering phase, the largest production of force is detectable in the m. biceps femoris and the highest bending moment in the proximal third of the metatarsal bone. The lowest influence of force resulted during the stance phase. During the stance phase, high forces are detectable only in the patellar ligament and middle-high forces in the m. flexor digitalis profundus. In contrast, bending forces are almost equal in strength in the metatarsus and tibia. The strongest forces are detectable in the m. quadriceps femoris and extreme demands of the patellar ligament as well as of the flexors in the proximal ankle joint during the stem phase.

Algorithms↗

The tolerability of nilvadipine compared to nifedipine in patients with essential hypertension.

In one multicenter, double-blind study, 659 hypertensive patients were treated for 16 weeks with either nilvadipine (n = 326) or nifedipine (n = 333). The major objective of the study was to compare the compatibility of the two calcium antagonists with regard to hepatic compatibility and side-effect profiles. The dosages were chosen so that the effective blood pressure reduction in both groups was equally good (mean decreases in systolic pressure of 27 +/- 12 mm Hg with nilvadipine and 26 +/- 15 mm Hg with nifedipine, and in diastolic pressure of 18 +/- 6 mm Hg with nilvadipine and 19 +/- 7 mm Hg with nifedipine). The mean heart rate was slightly lowered by about 2 beats/min by both substances. Although there was no effect on lipid or glucose levels, the serum glutamate-pyruvate transaminase (SPGT) levels were more often found to be raised in the nifedipine group than in the nilvadipine group (p < 0.05). The vasodilator effect of both calcium antagonists was responsible for side effects, of which the most common were flushing, edema, headache, and palpitations. The number of complaints was less in the group treated with nilvadipine than with nifedipine, especially flushing and edema. Significantly more patients in the nifedipine group withdrew from treatment due to undesirable side effects (p < 0.05).

Alanine Transaminase↗

The calcium messenger system and the kinetics of elastase release from human neutrophils in patients with abdominal aortic aneurysms.

Aortic elastase and neutrophil elastase is higher in patients with abdominal aortic aneurysms. The purpose of this study was to determine if these proteolytic elevations occur after abdominal aortic aneurysms have been repaired. Specifically, we studied the stimulation and inhibition of elastase degranulation from neutrophils in postoperative abdominal aortic aneurysm patients compared to aortic occlusive disease patients. Neutrophil elastase was determined in postoperative abdominal aortic aneurysm and aortic occlusive disease patients in response to calcium and the ionophore A23187. Inhibition of elastase release was determined with the calcium channel blocking agent Verapamil. Neutrophil elastase secretion was significantly higher in the abdominal aortic aneurysm patients (47%) versus aortic occlusive disease (20%) (p less than .05), while the effect of Verapamil in blocking this response was significantly lower in the abdominal aortic aneurysm patients (14%) compared to aortic occlusive disease patients (27%) (p less than .02). The time for degranulation to occur was longer in the abdominal aortic aneurysm patients (14.7 minutes) versus aortic occlusive disease patients (3.5 minutes), but the rate of secretion was not different between the two groups. These data indicate that, (1) neutrophils secrete more elastase in response to a calcium stimulus in abdominal aortic aneurysm patients; (2) it takes longer to secrete the increased amount of elastase in abdominal aortic aneurysm patients since the rate of secretion is similar between the two groups; and (3) Verapamil blocks elastase secretion ineffectively in abdominal aortic aneurysm patients. We conclude that the proteolytic alterations in abdominal aortic aneurysm patients are more likely a primary event and not a response to the abdominal aortic aneurysm and that Verapamil is a poor drug to use to medically manipulate the protease system in abdominal aortic aneurysm patients.

Aorta, Abdominal↗

[Potential cardiotonics. 7. Synthesis and cardiovascular effects of 5-(4-pyridinyl)-, 6-methyl-4-(4-pyridinyl) and 6-methyl-5-phenyl-substituted 3-cyano-2-aminoalkylamino-pyridines].

The title compounds were synthesized by treating of 2-chloro-pyridines 1-3 with the appropriate aminoalkylamines or piperazines. In isolated guinea pig atria some compounds showed greater positive inotropic activity than amrinone. Heart rate was decreased or remained unchanged. In anesthetized dogs some derivatives exerted a dose-dependent increase in myocardial contractility and, additionally, a decrease in blood pressure.

Animals↗

Gastroenterology, diagnosis-related groups, and age.

Hospitals are now being reimbursed by a prospective Diagnosis-Related Group (DRG) classification system. There have been no major changes in the Federal Medicare DRG classification system since its inception 5 years ago. In this project, we analyzed all gastrointestinal (GI) medicine admissions by age and resource utilization at a large academic medical center. Total hospital costs for the 3,598 GI patients (January 1, 1985, through December 31, 1987) were $18,460,604. Although DRG reimbursement for all patients for the 3-year period would have generated an aggregate profit of $957,760, four out of five age categories of patients 65 years of age and above would have generated losses; the highest loss was for patients 85 years and over, at $2,235 per patient. Older GI patients (i.e., 65 years and over) had higher hospital costs, longer lengths of stay, more diagnoses and procedures per patient, and a higher mortality rate than younger patients. Both intensive care unit (ICU) and blood utilization rose with age. Thus, older GI patients consumed a disproportionately larger share of hospital resources. Our study suggests that the current DRG reimbursement scheme may be inequitable relative to the older GI medicine patient; financial disincentives from DRGs may affect elderly patients' access to and quality of care in the future.

Academic Medical Centers↗

[X-ray crystallographic studies of diclofenac-sodium--structural analysis of diclofenac-sodium tetrahydrate].

The crystal structure of the hydrate of the antiphlogistic drug diclofenac sodium was determined to explain the unusual dissolution behaviour in ethyl acetate. The compound crystallizes in the monoclinic space group P2(1)/m with a = 9.464(2), b = 39.405(7), c = 9.972(3) A und beta = 90.74(2) degrees. The unit cell contains two symmetry independent formula units (C14H10Cl2NO2)-Na+.3,94 H2O. There are molecule layers and sodium-water layers which show order-disorder phenomena.

Crystallization↗

Percutaneous angioplasty for peripheral arterial occlusive disease. Correlates of clinical success.

We reviewed 142 percutaneous transluminal angioplasties (PTAs) in the iliac (n = 94) and femoropopliteal (n = 48) positions of 107 patients. Emphasis was placed on the ultimate clinical outcome, which was determined from a pool of clinical, hemodynamic, and angiographic data. Limb-threatening ischemia was the indication for intervention in 53% of the cases. The median follow-up interval was 17 months. Overall success was achieved in 50% of cases in both iliac and femoral positions at one year after PTA. The following factors were found to correlate with a successful clinical outcome: PTA for claudication vs limb-threatening ischemia (P less than .001); focal as opposed to diffuse stenosis or occlusion (P less than .02); immediate return of distal pulses (P less than .001); the absence of diabetes (P less than .05); and the presence of a patent outflow tract (P less than .001). Treatment results with PTA will vary widely according to the nature of the patient population and the criteria for determining success.

Aged↗

[The synthesis of 3-amino-5-(4-pyridinyl)-1,2-dihydropyrid-2-one (Cordemcura) from a technical mixture of pyridines].

For preclinical and clinical research the headline compound 6 has been synthesized from pyrid-4-yl-malondialdehyde (3) and its bis-N,N-dimethyl)-aldimin-derivative 1 by cyclization with cyanoacetamide giving 4, partial hydrolysis to the amide 5, and degradation by sodiumhypochlorite to the amine 6, concerning to the way described in patent literature. Starting product was a mixture of alkyl pyridines from which 4-picoline reacted selectively with the Vilsmeyer-complex of phosgene/DMF to give cristalline 1. Optimization in all steps resulted in a procedure that gives us the intermediates in good yields and qualities and the final product 6 with high purity, suitable for pharmaceutical use.

Aminopyridines↗