Biomedical subjects
Publications and source records attributed to M Fischer.
Even the concept of carpal stability is not clear. The complex anatomy of the multiple ligaments is difficult to understand. Arthroscopy is the golden standard in diagnosis of ligamentary tears. But the arthroscopical findings are in contrast to the today's classification of carpal instability.
The anatomy of the palmar scapho-triquetral ligament was studied: on 15 hand specimens by means of gross anatomical dissections and MR imaging; and on a further 10 foetal wrist specimens, microanatomically. This ligament allows us to present the proximal carpal row as a socket, consisting of an upper part (the triquetrum, distal part of the scaphoid, and the dorsal and palmar scapho-triquetral ligament), and a base (the concave parts of the lunatum and scaphoid, connected by the scapho-lunate ligament). With a hyperextension wrist injury the upper part follows the distal part of the carpus, while the base remains fixed at the radius. The upper part slips away from the base, consequently, injuring the ligamentous structure, or causing a scaphoid fracture. The luno-triquetral and the palmar scapho-triquetral ligaments are also frequently torn. The overall prognosis depends on the grade of ligament damage. The arthroscopy allows us to estimate the state of the ligament structures, therefore, it is indicated before any reconstructive operation.
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Forty-nine patients who had coronary artery reoperations were divided into two groups: the 29 patients of the first group were operated conventionally with use of one internal mammary artery or a saphenous vein; the 20 patients of the second group were reoperated using both internal mammary arteries. Three patients (6%) died prematurely: two in the first and one in the second group. The rates of peri-operative infarction were 7% and 15% respectively. The average postoperative bleeding was 472 +/- 385 ml in the first group and 700 +/- 628 ml in the second group (NS). All patients are pauci-symptomatic and have a negative exercise stress test. The mortality and morbidity of coronary reoperation does not seem to be greater with double internal mammary artery bypass grafting. However, this technique should be reserved for patients who can derive long-term benefit from reoperation with arterial grafts, that is to say in patients in good clinical condition, less than 65 years of age with good left ventricular function. In these patients, double internal mammary artery bypass grafting may avoid a third operation for myocardial revascularisation.
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In a series of twenty patients with carpal instability, arthroscopy detected 2,7 ligament tears per wrist. Fifty percent of the lesions were found in the radio-carpal compartment and 50% in the midcarpal compartment on the ulnar aspect. In 80% the tears were found to be combined in both compartments. These findings may be in contrast to today's classification of carpal instabilities. Arthroscopy is of great value in evaluating the most appropriate method of surgical repair on patients with carpal instability.
The cardiotoxic effects of bupivacaine are related to the temporal dispersion of effective refractory periods in different parts of the cardiac conduction system. This effect facilitates the occurrence of re-entry arrhythmias under burst stimulation [4, 8]. In this study physiological increments in heart rate were simulated by cardiac pacing, and the electrophysiological and haemodynamic effects under the influence of cardiotoxic concentrations of bupivacaine were measured. METHODS. After institutional approval we generated cardiotoxic arterial plasma concentrations of bupivacaine (6.9 +/- 1.6 micrograms/ml) in pigs (n = 8; 15-22 kg) by i.v. injection of 4 mg bupivacaine/kg, followed by a constant rate infusion of 0.2 mg/kg per min [8]. The pigs were anaesthetized with midazolam, fentanyl and pancuronium and normoventilated with a FiO2 of 0.4. Internal right atrial and right ventricular pacing was performed with increasing frequencies of 20, 40, 60, 80 and 100 stimulations/min above individual spontaneous heart rates (AL) before (control) and after the administration of bupivacaine. ECG, MAP, LVSP, dp/dtmax and stimulation thresholds were recorded. Student's t-test, and the U-test of Wilcoxon, Mann and Whitney were used for statistical testing with a significance level of 0.05. RESULTS. By inducing a frequency-dependent increase in stimulation threshold, bupivacaine prevented regular atrial pacing with frequencies higher than AL + 60. Ventricular pacing with a frequency of AL+40 induced a lethal arrhythmia in 1 animal. In the remaining 7 pigs ventricular pacing showed a frequency-dependent increase in stimulation thresholds (Fig. 1) and stimulus-QRS intervals (Fig. 5). MAP (Fig. 2), LVSP (Fig. 3) and cardiac inotropy (Fig. 4) showed frequency-dependent decreases under ventricular pacing. CONCLUSIONS. The toxic effects of bupivacaine on pacing thresholds, av conduction, intraventricular conduction, cardiac inotropy, and blood pressure are modulated by the stimulation frequency of a cardiac pacemaker. The cardiotoxic effects of bupivacaine seem to be use dependent. Even minor increments in heart rate can induce malignant arrhythmias. Cardiac pacing can be difficult in the presence of toxic bupivacaine concentrations, and high-frequency pacing should be avoided. It has to be verified whether higher heart rates generated by the physiological pacemakers of the heart do also increase the cardio-circulatory toxicity of bupivacaine. If that holds true, drugs that can induce tachycardias should be avoided in the treatment of bupivacaine toxicity.
Increased pressure on the lunate bone due to anatomical variance seems to be an important etiological factor in Kienböck's disease. Early diagnosis and treatment may prevent the development of carpal collapse. Ulnar lengthening and radial shortening have proven helpful in stages I-III of Kienböck's disease.
In a series of 45 patients with carpal instability, arthroscopy detected 2.9 ligament tears per wrist. The lesions were found in 50% in the radio-carpal compartment and in 50% in the midcarpal compartment on the ulnar aspect. In 70% the tears were found to be combined in both compartments. These findings may be in contrast to the today's classification of carpal instability. Arthroscopy is of great value in evaluating the most appropriate method of surgical repair on patients with carpal instability.
Localization procedures are required in adrenal diseases after biochemical confirmation of hormonal excess. Whereas computed tomography, ultrasound and--in rare cases--also magnetic resonance are needed to image the morphological abnormalities and the anatomy of neighbouring structures, adrenocortical and adrenomedullary scintigraphy is dependent on a functioning adrenal gland. Adrenocortical scintigraphy has the advantage of being able to differentiate between unilateral adenoma and bilateral hyperplasia in patients with primary hyperaldosteronism. It is of minor significance in patients with Cushing's syndrome or hyperandrogenism. In patients with catecholamine-producing tumours scintigraphy with radioiodine-labelled meta-iodobenzylguanidine (MIBG) may detect intra- and extra-adrenal, uni- and bilateral or multilocular, benign and malignant lesions. In patients with malignant but inoperable phaeochromocytoma, therapy with high doses of MIBG may improve clinical symptoms and reduce tumour volume.
103 patients suffering from recurrent venous thrombosis, recurrent arterial thromboembolism and/or recurrent myocardial infarction and 50 healthy subjects were tested for Hageman factor (F XII) coagulant activity and antigen. Among the 103 patients we identified 15 subjects with F XII deficiency (15%), 3 with protein C deficiency (3%) and 3 with protein S deficiency (3%). Combined F XII and protein C, protein S or antithrombin III deficiency was not observed. The 103 patients were divided into subgroups according to the type of thrombotic complication. Among patients with exclusively recurrent venous thromboembolism 8% (p = 0.153) were deficient in F XII. Among patients suffering from recurrent arterial thromboembolism and/or myocardial infarction, the incidence of F XII deficiency was significantly higher (20%, p < 0.003). In 67% of the patients with F XII deficiency a positive family history of thrombosis could be established. In contrast, only 32% (p = 0.043) of all venous and 28% (p = 0.019) of all arterial thrombosis patients had a positive family history. We believe that reduced levels of F XII should be considered as a risk factor in the development of thromboembolism. Consequently, more attention should be payed to the measurement of F XII when evaluating thromboembolic risk factors especially in cases of recurrent arterial thromboembolism and/or myocardial infarction.
Only few reports deal with local low dose thrombolysis of peripheral arterial occlusions by the infiltration technique with recombinant human tissue plasminogen activator (rTPA). We report the treatment of 45 cases (38 patients, 13 times women and 32 times men, aged 33 to 86 years). The patients suffered from thrombotic occlusions of the femoropopliteal artery (n = 39), a femoro-popliteal PTFE bypass (n = 3), a femorocrural bypass graft (n = 2) or a popliteal embolus (n = 1). The thrombus was infiltrated with 2.5 mg rTPA/hour attenuated to 30 ml normal saline solution. In the mean 7.1 mg rTPA was given. The rate of recanalisation was 76% during the days the patient stayed in hospital. The rate of recanalisation was higher (88%) in 16 cases suffering from acute arterial occlusion (< 24 hours). Even in those cases with undetectable or absent peripheral arterial runoff, therapeutic success was achieved at 92%.
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One hundred and three patients suffering from recurrent venous thrombosis, recurrent arterial thromboembolism and/or recurrent myocardial infarction and 50 healthy subjects were tested for Hageman factor (FXII) coagulant activity and antigen. Among the 103 patients we identified 15 subjects with FXII deficiency (15%), 3 with protein C deficiency (3%) and 3 with protein S deficiency (3%). Combined FXII and protein C, protein S or antithrombin III deficiency was not observed. The 103 patients were divided into subgroups according to the type of thrombotic complication. Among patients with exclusively recurrent venous thromboembolism 8% (p = 0.153) were deficient in FXII. Among patients suffering from recurrent arterial thromboembolism and/or myocardial infarction, the incidence of FXII deficiency was significantly higher (20%, p less than 0.003). In 67% of the patients with FXII deficiency a positive family history of thrombosis could be established. In contrast, only 32% of all venous and 28% of all arterial thrombosis patients had a positive family history. We believe that reduced levels of FXII should be considered as a risk factor in the development of thromboembolism. Consequently, more attention should be payed to the measurement of FXII when evaluating thromboembolic risk factors especially in cases of recurrent arterial thromboembolism and/or myocardial infarction.
This study follows our previous investigation describing the production of four cytokines (IL-2, IL-4, IFN-gamma, and TNF-alpha) by subsets of thymocytes defined by the expression of CD3, 4, 8, and 25. Here we investigate in greater detail subpopulations of CD4-CD8- double negative (DN) thymocytes. First we divided immature CD25-CD4-CD8-CD3- (CD25- triple negative) (TN) thymocytes into CD44+ and CD44- subsets. The CD44+ population includes very immature precursor T cells and produced high titers of IL-2, TNF-alpha, and IFN-gamma upon activation with calcium ionophore and phorbol ester. In contrast, the CD44- subset of CD25- TN thymocytes did not produce any of the cytokines studied under similar activation conditions. This observation indicates that the latter subset, which differentiates spontaneously in vitro into CD4+CD8+, already resembles CD4+CD8+ thymocytes (which do not produce any of the tested cytokines). We also subdivided the more mature CD3+ DN thymocytes into TCR-alpha beta- and TCR-gamma delta-bearing subsets. These cells produced cytokines upon activation with solid phase anti-CD3 mAb. gamma delta TCR+ DN thymocytes produced IL-2, IFN-gamma and TNF-alpha, whereas alpha beta TCR+ DN thymocytes produced IL-4, IFN-gamma, and TNF-alpha but not IL-2. We then studied alpha beta TCR+ DN T cells isolated from the spleen and found a similar cytokine production profile. Furthermore, splenic alpha beta TCR+ DN cells showed a TCR V beta gene expression profile reminiscent of alpha beta TCR+ DN thymocytes (predominant use of V beta 8.2). These observations suggest that at least some alpha beta TCR+ DN splenocytes are derived from alpha beta TCR+ DN thymocytes and also raises the possibility that these cells may play a role in the development of Th2 responses through their production of IL-4.
20 cats in a cat home were treated prophylactically and therapeutically with Baypamun HK. The animals were allocated into three groups as described. 7 freshly admitted clinically healthy cats were treated prophylactically on day 1, 2 and 9 with 1 ml Baypamun HK (group I). 7 cats, who already were allocated for one year in the home and were sick of the feline respiratory disease complex were treated as described for group I (group II). 6 further cats, who also showed symptoms of the feline respiratory disease complex and had stayed for one year in the home were treated with physiol.saline solution according to group I (group III). From all cats blood samples were taken at day 1, 3, 10 and 17. The blood samples were checked for antibodies against feline calicivirus (FCV), feline herpesvirus (FHV), panleukopenia virus (PLV), feline peritonitis virus (FIPV) and feline immunodeficiency virus (FIV). Also the occurrence of the feline leukemia virus (FeLV) was evaluated. The cellular immunity was evaluated by means of the lymphocyte transformations test (LTT), nitroblue-tetrazolium reduction test (NBT) and cytochrome C-reduction test (CRT). Mean value and standard deviation was calculated from the results. The significance was determined by the t-test. The animals were examined clinically daily for 20 days for the feline respiratory disease complex. When necessary, the animals were treated by homeopathic and antibiotic products. At the time of admission to the home all cats were or had been treated with an attenuated panleukopenia vaccine. The serologic parameters were not influenced in the cats of group I.(ABSTRACT TRUNCATED AT 250 WORDS)
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PrPC is a host protein anchored to the outer surface of neurons and to a lesser extent of lymphocytes and other cells. The transmissible agent (prion) responsible for scrapie is believed to be a modified form of PrPC. Mice homozygous for disrupted PrP genes have been generated. Surprisingly, they develop and behave normally for at least seven months, and no immunological defects are apparent. It is now feasible to determine whether mice devoid of PrPC can propagate prions and are susceptible to scrapie pathogenesis.