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Biomedical subjects

B Graf

Publications and source records attributed to B Graf.

At least 37 records · Page 2Linked to original sources

Circulating microemboli in patients after aortic valve replacement with pulmonary autografts and mechanical valve prostheses.

BACKGROUND: The pulmonary autograft procedure (Ross) is now considered the gold standard for aortic valve replacement. One of its advantages is the freedom from macroemboli without anticoagulation. Whether this holds true for circulating microemboli, detectable as high-intensity transient Doppler signals (HITS), has not yet been verified. METHODS AND RESULTS: We investigated 8 patients (2 women, 6 men; mean age, 50.6+/-17.9 years) after the Ross procedure, 9 patients (3 women, 6 men; mean age, 67.2+/-9.46 years) after aortic valve replacement with a mechanical valve prosthesis, and 12 young healthy volunteers by unilateral 1-hour recording of the middle cerebral artery on digital audio tape. Patients with extracranial carotid artery disease were excluded by color duplex sonography. During the off-line evaluation, the investigator was not aware of any patient details. No HITS were detected in healthy volunteers (95% confidence interval [CI], 0% to 26.46%). After the Ross procedure, 1 patient had 11 and 1 patient had 1 HITS (95% CI, 3.19% to 65.09%). All recipients of mechanical valves had HITS, ranging from 2 to 84 per hour (95% CI, 66.7% to 100%). Significantly more recipients of mechanical valves exhibited HITS than recipients of pulmonary autografts (P<.05) or control subjects (P<.05). CONCLUSIONS: In contrast to mechanical valves, pulmonary autografts are seldom the source of microemboli, confirming the pulmonary autograft as the superior substitute for aortic valve replacement.

Adult↗

[Risk and prevention of thromboembolism complications in gynecologic malignancies].

Gynecologic malignancies are often associated with deep vein thrombosis and pulmonary embolism, even before treatment is begun. But such complications also happen during treatment, also if thromboembolism prophylaxis is performed. The incidence of pulmonary embolism before treatment was investigated using scintigraphy. In a retrospective and in a prospective randomized trial, various methods of thromboembolism prophylaxis were evaluated during primary or postoperative radiation therapy. Pulmonary embolism was present in 11.9% of the patients admitted with uterine malignancy. Retrospectively, there were deep vein thromboses in 6.8%, pulmonary embolisms in 3.8% and bleeding complications in 5.3% of the patients receiving thromboembolism prophylaxis with acenocoumarol during radiation therapy of cervical and endometrial cancer. In the prospective study, deep vein thromboses occurred in 1.5%, pulmonary embolisms in 5.9% and bleedings in 2.2%, with both the LMW heparin and the acenocoumarol groups presenting similar results. Thromboembolism is a frequent paraneoplasia of uterine malignancies. The prevention of thromboembolic complications during radiation therapy of uterine malignancies is efficacious and safe using either LMW heparin or acenocoumarol.

Acenocoumarol↗

The effect of tourniquet use on postoperative strength recovery after arthroscopic meniscectomy.

The purpose of this prospective study was to determine the effect of pneumatic tourniquet use during arthroscopic meniscectomy on postoperative recovery of quadriceps and hamstring strength. Thirty-four patients with no ligamentous instability underwent arthroscopic meniscectomy after random assignment to the tourniquet or no tourniquet group. Tourniquet pressure was determined with a nomogram that considered thigh circumference and systolic blood pressure at time of induction. Quadriceps and hamstring strengths were tested preoperatively and at 1 week and 4 weeks postoperatively on a Biodex isokinetic dynamometer and expressed as a percentage of the uninvolved side. No significant differences in quadriceps or hamstring strength were noted between groups at any time periods. The findings of this study indicate that recovery of quadriceps and hamstring strength after arthroscopic meniscectomy is not adversely affected by tourniquet use if tourniquet times and pressures are carefully controlled.

Adolescent↗

[Developmental trends in farm animal husbandry from an ethological point of view].

The current discussion on "semi-natural" or "extensive" animal production and husbandry shows that such terms are vague and are often used for various meanings. This paper addresses what can be referred to as natural environmental conditions from an ethological point of view, as well as the animal's environment in today's animal production, and how "near to nature" animal husbandry can realistically be. Apart from some outdoor systems with few ethological problems, the predominant part of milk and meat production in the future will still largely take place indoors. Thus, the development of housing conditions which are more appropriate to the animal's needs will still be an important issue of farm animal behaviour science. Consequently the essential environmental requirements of cattle and pigs derived from their species-specific behaviour are described and explained. In the future, an improved fulfillment of ethological requirements will lead to increased group housing in cold and open, structured barns with indoor straw-bedded lying compartments and integrated outdoor feeding and activity areas. This process will also be influenced by ecological, economic and technical aspects. Finally, several studies on cattle and pigs are presented which demonstrate the possible benefits from more appropriate housing systems or the fulfillment of single ethological requirements regarding behaviour, health, fertility and production of the animals.

Animal Husbandry↗

Evoked potential monitoring during repeatedly induced ventricular fibrillation for internal defibrillator implantation.

Repeated induction of ventricular fibrillation (VF) with circulatory compromise during implantable cardioverter defibrillator (ICD) testing may cause cerebral injury. To test this hypothesis, somatosensory evoked potentials (SEP), a more sensitive marker of injury, were recorded in patients (N = 10) undergoing ICD implantation. SEP were recorded before induction of anesthesia, after induction of anesthesia, before and at several times following induction of VF. Possible modifying factors of the SEP measurements such as anesthetic application, blood pressure, body temperature, and hematocrit remained constant throughout the operations. Central conduction time was unaffected by ICD defibrillation testing. Amplitude of SEP primary complexes was transiently reduced at 34.9% (P < 0.01) by defibrillation testing, but returned to control within 10 minutes after testing. It is concluded that while ICD defibrillation testing may produce transient changes in SEP, there is no evidence of residual cerebral injury.

Adult↗

Increased serum concentrations of adhesion molecules after coronary angioplasty.

1. Reocclusion is still a significant complication after percutaneous transluminal coronary angioplasty. The injury of coronary arteries resulting from PTCA plays an important role in the pathophysiology of both abrupt closure and late restenosis after an initially successful procedure. Cytokines play a pivotal role in the accumulation of circulating blood cells at the endothelium and are known to regulate their interaction with the vessel wall. 2. To obtain further information about this interaction, serum concentrations of soluble endothelial leukocyte adhesion molecule 1 (sELAM-1), leucocyte endothelial cell adhesion molecule 1 (sL-selectin), intercellular adhesion molecule 1 (sICAM-1), interleukin 2 receptor (sIL-2R) and interleukin 8 (IL-8) detected by enzyme-linked immunosorbent assay were monitored in 30 consecutive patients referred for elective PTCA. Fifteen patients who underwent elective coronary angiography without PTCA served as controls. 3. All patients underwent successful first PTCA. Within 24 h the serum concentrations of sELAM-1 increased gradually from 21.7 (SD 7.1) to 48.2 (SD 8.6) ng/ml (P < 0.01); levels of sL-selectin rose from 982.1 (SD 128.7) to 1541.3 (SD 104.6) ng/ml after 48 h (P < 0.01). Serum levels of IL-8 remained stable initially, but peaked at the end of the observation time of 72 h (9.4, SD 3.8, versus 16.1, SD 4.9 ng/ml; P < 0.05). A positive correlation was found between the number of dilatations and the rise in these parameters (P < 0.01). No significant changes were found in the serum concentrations of sICAM-1 and sIL-2R after PTCA or in any of the parameters in patients after coronary angiography. 4. We conclude that PTCA induces a significant rise in the concentration of certain adhesion molecules in serum. Thus, we provide preliminary data on the potential role of cytokines for blood cell-endothelium interaction after PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

An OspA serotyping system for Borrelia burgdorferi based on reactivity with monoclonal antibodies and OspA sequence analysis.

A total of 136 Borrelia burgdorferi sensu latu strains from various biological sources (ticks, human skin, and cerebrospinal fluid) and geographical sources (Europe and North America) were investigated by Western blot (immunoblot) with eight monoclonal antibodies against different epitopes of the outer surface protein A (OspA). On the basis of the differential reactivities of these monoclonal antibodies, seven OspA serotypes were defined. As determined by 16S rRNA sequence analysis, these serotypes correlated well with recently delineated genospecies: serotype 1 corresponds to B. burgdorferi sensu strictu, serotype 2 corresponds to group VS461, and serotypes 3 to 7 correspond to Borrelia garinii sp. nov. (G. Baranton, D. Postic, I. Saint Girons, P. Boerlin, J.-C. Piffaretti, M. Assous, and P. A. D. Grimont, Int. J. Syst. Bacteriol. 42:378-383, 1992). Antigenic differences were confirmed by partial sequence analysis of OspA of representatives of each serotype. Comparative sequence analysis suggested that serotype 5 OspA resulted from genetic recombination of serotype 4 and 6 ospA genes. Serotype 2 (group VS461) was most prevalent among European skin isolates (49 of 62 isolates). Among all B. garinii strains included in this study, serotype 6 was most frequently found in ticks and only rarely in human skin and cerebrospinal fluid, whereas serotypes 4 and 5 were isolated from patients but never from ticks. Our data suggest different pathogenic potentials and organotropisms of distinct OspA serotypes and raise the question of true antigenic variation among B. garinii strains.

Amino Acid Sequence↗

Effect of knee joint laxity on long-loop postural reflexes: evidence for a human capsular-hamstring reflex.

The onset latency and discharge amplitude of preprogrammed postural responses were evaluated in order to determine if the structure of synergistic activation could be altered by ligamentous laxity at the knee joint. Twelve subjects with unilateral and one subject with bilateral anterior cruciate ligament (ACL) insufficiency were tested while standing on a moveable platform. External balance perturbations (6 cm anterior or posterior horizontal displacements of the platform) were presented at velocities ranging from 15 to 35 cm/s. Perturbations were presented under the following experimental conditions: unilateral and bilateral stance, knees fully straight or flexed, and with ankle motion restricted or free. These stance, knee position, and ankle motion conditions were introduced to alter the stress transmitted to the knee joint during movement of the support surface. The automatic postural response was recorded from the tibialis anterior (T), quadriceps (Q), and medial hamstrings muscles (H) bilaterally. The normal response to an externally induced backward sway involved the automatic activation of T and Q at latencies of 80 ms and 90 ms respectively. Activation of the hamstrings in the non-injured extremity was not coupled with the postural response. Hamstrings are not typically involved in the correction posterior sway because H activation would tend to pull the center of mass further backwards. However, when the response in the ACL-deficient extremity was compared to the non-injured limb: (1) the automatic postural response in the ACL-deficient extremity was restructured to include hamstrings activation (100 ms latency), (2) H activation time was faster and less variable in the ACL-deficient limb, and (3) the ratio of H/Q discharge amplitude integrated over 100 ms and 200 ms from the onset of EMG activation showed a dominance of hamstring activity during unilateral stance on the lax limb. In addition, H/Q ratios integrated over 200 ms showed dominant hamstring activity in the ACL-deficient limb during bilateral stance. (4) Cross-limb comparisons showed greater normalized IEMG amplitudes for T, H, and Q during unilateral stance on the lax limb. These results suggest that a capsular-hamstring reflex is integrated into the existing structure of a preprogrammed postural synergy in order to compensate for ligamentous laxity. Furthermore, the generalized increase of response gain observed during perturbations of unilateral stance on the lax limb indicates that joint afference can modulate central programming to control localized joint hypermobility. A concept of postural control is discussed with respect to the capsular reflex, joint loading and displacement of the center of gravity.

Adolescent↗

[The incidence of silent myocardial ischemia].

Retrospectively evaluated was the patient population of the years 1982 to 1988 which underwent ergometric investigations concerning the appearance of silent myocardial ischaemias. In 256 reactions of exercise ischaemia of patients with definitive coronary disease in 47 cases angina pectoris appeared (18.4%). Reactions of ischaemia in a large area of the breast wall showed, compared with a small area of ischaemia, a significantly higher proportion of symptomatic episodes (34.3% vs 13.0%, P less than 0.05). Ergometric exercises lying below the norm of age were more frequently accompanied by symptomatic ischaemias than ischaemic reactions, which only appeared in a good area of performance (26.0% vs 11.4%, P less than 0.05). In addition to this more anginose complaints were found in patients, whose ischaemic reaction was accompanied by an insufficient frequency response (28.1% vs 9.8%, P less than 0.05).

Angina Pectoris↗

[Pneumonia prevention in long-term mechanically ventilated patients: selective skin decontamination according to Stoutenbeek or prevention of colonization according to Unertl? A prospective randomized comparison of both treatments].

In a prospective randomised study, the effects of two different colonisation prophylaxis techniques on colonisation and pulmonary infection were investigated in 40 critically ill patients with long-term ventilatory support (greater than or equal to 4 days). 20 patients were selectively decontaminated with 4 x 100 g polymyxin E, 4 x 80 mg tobramycin and 4 x 500 mg amphotericin B, administered through the gastric tube and with an antimicrobial sticky paste in the oropharynx (group I). 20 patients received 50 mg of polymyxin B and 80 mg of gentamicin dissolved in 10 ml of 0.9% saline at 6 h intervals into nose, oropharynx and stomach as well as 300 mg of amphotericin B in the oropharynx only (group II). All patients received cefotaxime systemically in the first 3 days. In group I gram-negative aerobic bacteria in the pharynx decreased from 35% to 0%, in group II from 40% to 10% and in the rectum from 80% to 61% (10% in the second week) in Group I and from 100% to 73% (33% in the second week) in group II. The decrease in gram-negative microorganisms was accompanied by an increase in the frequency of Staphylococcus epidermidis. In group I, two patients developed pneumonia and two patients urinary tract infections, in group II two patients suffered from pneumonia and 3 patients urinary tract infections. Both regimes are effective methods of prophylaxis for lowering colonisation with gram-negative aerobic bacteria and the frequency of pneumonia in patients requiring long-term mechanical ventilation. A possible selection of gram-positive bacteria must be appropriately monitored.

Adult↗

[Endogenous candida endophthalmitis: a new therapy].

A thirty-year-old patient underwent an extensive abdominal surgery because of a precancerosis due to a colitis ulcerosa. An accompanying smoldering panuveitis led under immunosuppressive therapy to the loss of sight of one eye. Only an increasing vitritis of the second eye allowed the diagnosis of an endogenous Candida endophthalmitis (ECE) following a vitrectomy. A systemic administration of the common antifungal medications was impossible because of the patient's pathological blood-picture and a severe cholestasis. We report the successful use of Fluconazol (Diflucan), an antimycotic agent we never used before in this connection.

Adult↗

[Effects of diltiazem in acute and long-term administration].

In 16 patients with unstable angina pectoris haemodynamic and clinical effects of diltiazem were investigated. In a second group patients (n = 11) with unstable or therapy-refractory course the long-term effect was tested. The acute intervention with injected and infused diltiazem via an improved oxygen balance due to decreased minute work and reduced product of cardiac frequency and pressure stabilized the clinical picture from the haemodynamic aspect. The decreases of the ST segment were significantly lower. In the long-term use a significant influence on the frequency of angina pectoris with increase of the range of efficacy by one NYHA-state was the result. Diltiazem can be regarded as alternative medicament in unstable phases and in therapy-refractory courses of the chronic coronary heart disease.

Angina, Unstable↗

[Treatment indications of hypertensive blood pressure dysregulation (a 7-year follow-up)].

The results of the present course investigations by means of bicycle ergometry over seven years on patients with vitality-limiting load hypertension in normotensive and initial situation of the borderline blood pressure, respectively, render necessary from the point of view of the authors an increase of the former indications to treatment. Situative measurement of blood pressure only at rest are hereby not sufficient and demand a bicycle-ergometric objectivation of the possible hypertensive dysregulation of blood pressure in patients with anamnestically restricted range of physical efficacy. In patients with exclusively under load increased vitality-limiting blood pressure values the ergometry represents the diagnostic method of choice.

Adult↗

[The status of prazosin in therapy of chronic heart failure].

Cardiac dysfunction and neurohumoral dysregulation show that the administration of vasodilators is reasonable in a cardiac insufficiency which is therapy-refractory against glycosides and saluretics. The alpha 1-blocker prazosin is a potent substance. On the basis of haemodynamic investigations of 55 patients the acute effects are demonstrated. Depending upon the degree of the cardiac insufficiency and the sympathetic dysregulation--measured at the behaviour of the resistance--the acute effects are convincing in more than 60% of the patients. For the long-term course patients with unequivocal initial improvement are suitable. This group can undergo a satisfactory therapy for a longer time by means of a carefully increased dosage, by corrections of the application of saluretics and by short interruptions of therapy and by the change of the dilator, respectively, or by an additional administration of another vasodilator. In the total spectre of the vasodilators which are administered in cardiac insufficiency prazosin occupies one of the first places.

Cardiomyopathy, Dilated↗

[Kineto- and displacement cardiography in heart valve diseases and possible diagnostic values].

With the help of the method of the kinetocardiography (KKG) inaugurated by Eddleman and the displacement cardiography (DKG) using a high fidelity changer, apart from a control group of 12 test persons with healthy heart 8 different groups of cardiac abnormalities consisting of altogether 88 patients were examined. Displacement cardiography and kinetocardiography did not significantly differ in the course of the curves. The courses of the curves for the cardiac abnormalities proved reproducible. There were significant differences in at least 6 parameters of the curves (p less than 0.05 to p less than 0.001) between the control group and each group with cardiac abnormalities. Linear correlations between the parameters of the curves and invasively gained cardial parameters confirm relations relevant to cardiac abnormalities. In future in possible computer assisted analyses of curves a better rational evaluation in controls of the curves will be the result. The value of this methodology lies in the character of the parameters confirming the cardiac abnormalities. The disadvantage consists in the absent exact quantification of the degree of severity.

Adult↗

Retrovirus and periosteal osteogenic cells. Morphology study.

A cortical hyperostosis is induced by injection of myeloblastic virus MAV 2 (O) in direct contact with periosteum, in chicken just after hatching. It appears an hyperplasia of osteogenic cells of the endoperiosteum. The enchondral ossification develops in normal condition. This lesion is quite different from osteopetrosis.

Animals↗

Complications of intra-articular anterior cruciate reconstruction.

Intra-articular reconstruction of the ACL is a powerful technique, but is associated with a variety of potential complications. Careful patient selection, precise intraoperative technique, and aggressive rehabilitation can help minimize these problems. Our most common complication, postoperative limitation of motion, was nearly eliminated by a change to arthroscopic surgical technique and early motion.

Arthroplasty↗