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Biomedical subjects

C Bader

Publications and source records attributed to C Bader.

At least 19 recordsLinked to original sources
PubMed1999

Anatomy teaching for medical undergraduates: general practice as a guideline? The brain.

Basic science teaching, particularly the teaching of gross anatomy, is at present a highly controversial topic. How much and what kind of anatomy should be taught to medical undergraduates nowadays? In conducting the present study we based our proposals on the criterion of general medical relevance. Therefore, we sent an anatomical questionnaire to a sample of Swiss general practitioners. Here, we present the results derived from questions on the human brain, discussing them in connection with the other organs so far investigated. The results obtained suggest that a common body of anatomical knowledge appropriate for the field of general medical practice does in fact exist. We believe that this basic stock can serve as a guideline for decision makers involved in the development of curricula, which can be fitted into the time frame available for anatomy teaching today while still guaranteeing a sound level of competence required for general practice of medicine. We also hope that this approach may serve as a model for the teaching of other basic sciences.

Anatomy↗
PubMed1998

Carotid atherosclerosis in renal transplant recipients.

BACKGROUND: Cardiovascular accidents are the major cause of morbidity and mortality in renal transplant recipients. However, there is little information concerning carotid atherosclerotic wall changes in renal transplant recipients, their relationship with cardiovascular accidents and their possible association with cardiovascular risk factors in such patients. METHODS: Between April 1991 and December 1997, we prospectively assessed cardiovascular accidents in 79 renal transplant recipients who had received a transplant at our institution before January 1, 1986. Carotid morphology by B-mode ultrasonography, relevant clinical and laboratory cardiovascular risk factors, including lipid abnormalities and total homocyst(e)ine, were determined at the start of the follow-up period. Seventeen healthy subjects matched for age and sex with renal transplant recipients served as controls who volunteered for ultrasonographic examination of carotid arteries. RESULTS: Nine patients experienced cardiovascular events during the period of follow-up. Compared with healthy, age- and sex-matched control subjects (n = 17), the frequency of carotid plaques was higher in renal transplant recipients with cardiovascular events (n = 9), but not in those without such events (n = 70). The frequency of cardiovascular accidents was related to the number of carotid plaques (4, 17 and 24% for no plaque, one plaque and > 1 plaque respectively, P < 0.04). However, by multivariate analysis, serum total cholesterol [odds ratio (OR) of 1.8 for each 1.0 mM, P < 0.07) and the presence of diabetes mellitus (OR of 28.4 for presence, P < 0.01) were the only predictors of cardiovascular events in such patients, whereas the presence of carotid plaques was not. Moreover, neither serum lipoprotein (a) nor total homocyst(e)ine concentrations could be identified as risk factors. CONCLUSIONS: This prospective study shows that although a close association exists between asymptomatic carotid atherosclerosis and cardiovascular accidents in renal transplant recipients with long-term follow-up and relatively good renal function, other potentially modifiable risk factors appear to be better predictors of cardiovascular events. Consequently, the assessment of carotid atherosclerosis may not be clinically useful for the systematic identification of renal transplant recipients with an increased risk of developing cardiovascular events.

Adult↗
PubMed1996

Fourier transform infrared microscopy identification of crystal deposits in tissues: clinical importance in various pathologies.

The presence of crystal deposits in tissues is associated with various pathologies. Sometimes their identification is useful for understanding the etiology or the mechanism of the disorder. The authors applied Fourier transform infrared microscopy (FTIRM) to the molecular characterization of crystal deposits in tissue and compared the results with those provided by histologic studies using polarized light microscope and histochemical reactions. Twenty-five biopsies were investigated. In 10 cases, the results were in good agreement. In 15 cases only FTIRM could precisely identify the crystals. In three cases, this technique allowed to characterize dihydroxyadenine crystals revealing an adenine phosphoribosyltransferase deficiency previously undiagnosed in patients presenting severe chronic renal failure. In three cases, crystal deposition was related to drug therapy. In other cases, crystal identification was useful to understand the mechanism of the pathology responsible for tissue damage and crystal deposition.

Adenine↗
PubMed1996

Predictive value of magnetic resonance imaging and computerized tomography for conservative renal surgery in an ex vivo tumor enucleation study followed by step-sectioning.

PURPOSE: Due to the early diagnosis of many renal cell cancers, the treatment options of organ conserving surgery is of interest even for patients with a normal contralateral kidney. To our knowledge the predictive value of preoperative investigations in such patients has not been clarified. MATERIALS AND METHODS: In a prospective study of 30 patients with stage T1/T2 renal cell carcinoma ex vivo enucleation was performed following tumor nephrectomy. Magnetic resonance imaging (MRI) and computerized tomography (CT) were done preoperatively in all patients. For pathological evaluation the kidneys were step-sectioned in 1 mm. slices. Macroscopic and microscopic findings were compared to those of the preoperative investigations. RESULTS: Mean tumor diameter was 4.6 cm. (range 2.0 to 10.0). Twelve tumors were incidental and smaller than 4 cm. Residual carcinoma due to incomplete resection was found in 4 kidneys with tumors larger than 4 cm. Parenchymal or hilar venous invasion was noted in 4 cases, including 1 in the incidental group. Prediction of renal fat capsule invasion by MRI was highly confirmed by pathological examination. On the other hand, parenchymal venous involvement or secondary renal tumors smaller than 2 cm. could not be predicted by MRI or CT. CONCLUSIONS: Neither MRI nor CT predicts complete tumor control when conservative renal surgery is considered. All incidental tumors smaller than 4 cm. could be resected completely by nephron sparing surgery. Nevertheless, microscopic venous invasion was present in 1 of the latter cases.

Adult↗
PubMed1994

[Dynamic arthro-CT in the diagnosis of recurrent shoulder dislocations].

"Dynamic" double contrast arthro-CT in internal and external rotation was performed on 42 patients with recurrent subluxation of the shoulder. The differential distribution of contrast and air caused by the rotation resulted in optimal demonstration of the capsulo-labrale components responsible for joint stability. In 22 patients there appeared to be an indication for arthroscopy; this confirmed the previous findings. In all cases the anterior part of the capsule and the middle and lower labrum were seen best during internal rotation. In this way all the 15 anterior capsule lesions could be seen, as well as 16 out of 17 Bankart lesions; it also showed one lesion of the middle labrum which had been masked by a haemarthrosis during external rotation. The study also defined lesions of the upper labrum caused by a different pathological mechanism which was present in 7 patients (6 Andrews and 1 S.L.A.P. lesion). These and 2 posterior labrum tears could be diagnosed during external rotation. Sensitivity for lesions of the anterior labrum was 95%.

Adolescent↗
PubMed1994

Stereotactic and ultrasound guided minimal invasive surgery of subcortical cavernomas.

The experience of 7 operated patients with cavernous haemangiomas (CHa) and of 2 conservatively treated older patients is reported. There was no further postoperative neurological deficit, although 6 of the 7 patients had the CHa in an eloquent cerebral region. Two of the operated patients (22%) had several bleedings before surgery. In these cases seizures and visual field deficits remained. The relatively low rate of complications in our patient group was possible because an exact preoperative localisation helped to avoid a large traumatisation. This is possible with a stereotactic system or directly by CT guided skin marking. Intraoperative ultrasound was necessary in all cases because there was no landmark at the cerebral surface. The CHa was removed by a transsulcal microsurgical operation. A complete removal of the surrounding haemosiderin rim around the angioma seems necessary to avoid further seizures. The used technique has proved to be a simple and safe minimal invasive method.

Adolescent↗
PubMed1994

Endoscopic fenestration of the 3rd ventricular floor in aqueductal stenosis.

Six endoscopic fenestrations of the 3rd ventricular floor have been performed in patients with stenosis (SAS) of the aqueduct of Sylvius in our institute during the last two years. The endoscopic intraventricular landmarks were the Monro's foramen followed by the mamillary bodies. The fenestration instrument was a monopolar coagulation wire, the dilatation instrument was a balloon catheter. The patients included two newborns and four adults. The two newborns developed a recurrent hydrocephalus after 2 months. The four adults remained well after the operation. The only complication was edema (SIADH syndrome) in one case for 24 hours. Flow sensitised phase MRI showed a mirroring in the prestenotic CSF pulsation curve preoperatively. This, in combination with an increased intraventricular pulsation, is a sign of reduced capacity of the subarachnoid space at the cerebral surface. The postoperative patency of the fenestration with diminished intraventricular pulsation can be demonstrated with ECG retrogated phase MRI. There was a slow and incomplete decrease of the preoperative enlarged ventricular size. This operative method is a low-risk, minimal invasive alternative method to shunt implantation in adults with SAS.

Adult↗
PubMed1994

Influence of various calcium intakes on calcium-oxalate crystalluria in rats on sodium-oxalate diet.

Forty adult male Wistar rats were placed in metabolic cages on a Ca-deficient diet (0.1%) for 7 days and then on a Ca-deficient, Na-oxalate (NaOx) enriched diet (20 mg/100 g) for another 14 days. The animals were subdivided into three groups receiving three different types of mineral water: group I (n = 13), Badoit (Ca 222 mg/l); group II (n = 14), Contrexéville (Ca 467 mg/l); and group III (n = 13), Evian (Ca 78 mg/l). Another series of 25 rats (group I, n = 9; group II, n = 8; group III, n = 8) underwent the same study protocol, except that they received a normal Ca diet (1%). On the low-Ca diet, urinary Ca-Ox monohydrate (COM) crystals were observed only under the Na-Ox diet, with a mean crystal number significantly greater in group III (16.7 +/- 4.5 crystals/mm3) than in group I or II rats (2.5 +/- 1.5 or 4.1 +/- 1.5 crystals/mm3, respectively). Urinary Ca concentrations decreased in all groups (P < 0.001) under the Na-Ox diet, while urinary oxalate concentrations increased in all groups (P < 0.001). On the normal Ca diet, COM crystal excretion was observed only with the Na-Ox-enriched diet, but in this case feeding the Na-Ox diet did not modify urinary oxalate excretion. Ca/Ox ratio was significantly lower under 0.1% Ca diet than under normal Ca diet, related with the type and the number of crystals observed, demonstrating that assessment of crystalluria can provide an index of disease severity. Moreover, the hardness of the drinking water influences urinary COM crystal excretion only under a low-Ca, oxalate-rich diet, suggesting that the total calcium intake rather than the water calcium content is an important factor in the occurrence of Ca-Ox nephrolithiasis.

Animals↗
PubMed1993

[The postoperative MR tomographic findings following the removal of a hypophyseal adenoma].

36 patients with pituitary adenomas were examined via MRI to describe physiological changes and to visualise a residual tumour. Pre- and postoperative examinations included T1- and T2-weighted SE sequences. T1-weighted images were obtained in sagittal and coronal orientation pre- and post-Gd-DTPA application and T2-weighted images in coronal orientation. In 12 cases a residual tumour was found. Its signal intensity and contrast enhancement were similar to those of the primary tumour. Implanted material could be distinguished by localisation, decrease in volume and different signal intensity. The behaviour of contrast enhancement was helpful, since implanted material showed a rim enhancement. In our experience a sensitive imaging protocol in the follow-up of operated pituitary adenomas would be an early examination three months postoperatively followed by a control examination after one year. Information on the size and localisation of the primary tumour and the performed operative procedure is essential.

Adenoma↗
PubMed1993

[The CT classification of intra-articular calcaneus fractures].

93 patients with 102 intraarticular calcaneus fractures (ICF) were examined by CT from 1986 to 1992. The images were evaluated with the use of a modified classification based on the number of fractured heel bone facets (2 facets in 4.8%, 3 facets in 53.9%, 4 facets in 32.3%, comminution in 8.8% of the fractures), the involvement of the calcaneus-cuboid joint (60.8%) and the fracture mechanism (tongue-type in 28.4%, joint depression in 62.7%) with the weight-bearing calcaneal compartments taken into special consideration. In that way, each intraarticular calcaneus fracture could be scored, enabling a fast diagnosis comprising factors relevant for the therapy and prognosis.

Adolescent↗
PubMed1992

Increasing short-term fluctuation by increasing the intensity of the fixation aid during perimetry.

An increase in short-term fluctuation is a clinically useful clue in the diagnosis of acquired disorders of the visual pathways. However, short-term fluctuation can also be increased in normal subjects by several factors. We found an increase in short-term fluctuation occurred in normal subjects when the visual field was tested using a bright fixation aid. Eight normal subjects underwent automated perimetry with the Octopus 2000R, in which the dimmest (12.5 candelas/m2) and brightest (435 cd/m2) available fixation aids were used. Mean short-term fluctuation values were 1.63 +/- 0.27 dB with the dimmest aid, and were 2.65 +/- 1.26 dB with the brightest aid. The difference was significant using the paired t-test (P = .037). Moreover, mean sensitivity was reduced from 35.67 +/- 2.26 dB to 33.66 +/- 1.71 dB when the brightest fixation aid was used (P = .004). In six of eight subjects, the relative changes in short-term fluctuation after an increase in brightness of the fixation aid were more pronounced than those in mean sensitivity. An increase in intensity of the fixation aid may cause visual changes in normal subjects that resemble those induced by disorders in the visual pathways. Whenever possible, minimal intensity of the fixation aid should be used to allow for an adequate interpretation of short-term fluctuation values.

Adult↗