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Biomedical subjects

G Becker

Publications and source records attributed to G Becker.

At least 361 records · Page 20Linked to original sources
PubMedDate not supplied

A medical workstation for the evaluation of alternative 3D radiotherapy treatment plans.

A medical workstation for the evaluation of alternative 3D radiotherapy plans is described. Our system can simultaneously apply qualitative as well as quantitative evaluation methods to as many as three 3D dose distributions. The user interface of the workstation has been designed with the demands of radiation oncologists in mind. The handling of the large amounts of 3D data (CT data, up to three 3D dose distributions, volumes of interest) is assisted by computer graphics.

Computer Graphics↗
PubMedDate not supplied

Local versus regional procurement and distribution of granulocytes.

Granulocyte concentrates obtained by discontinuous flow centrifugation (DFC) and continuous flow centrifugation (CFC) were studied. The DFC granulocytes were obtained from a regional center and stored for 24 hours prior to transfusion. The CFC granulocytes were obtained locally and transfused within a few hours. Even at 24 hours, DFC granulocytes had significantly reduced bactericidal capacity, chemiluminescence, nitroblue tetrazolium reduction, chemotaxis and random mobility. Granulocyte kinetics utilizing DF32P and skin windows demonstrated the ability of DFC granulocytes to circulate and migrate into the tissues despite the in vitro abnormalities. Until effective storage techniques for granulocyte preservation became available, rapid transportation and processing from regional centers or local procurement of granulocytes is necessary to transfuse functional granulocytes.

Blood Bactericidal Activity↗
PubMedDate not supplied

[Long-term results in complex knee injuries using sutures and reconstruction of the posterior cruciate ligament].

There is still a great discussion what's the best treatment for disruptions of the posterior cruciate ligament. The results of the operations are often bad. In Rheinfelden from 1979 to 1990 34 Patients underwent an operation of the posterior cruciate ligament. In 1991 we made a follow-up evaluation with 30 of these patients. The results according the OAK-Score were 8 x excellent, 11 x good, 3 x fair and 5 x poor, 3 patients were reoperated elsewhere. The average Lysholm score was 79 points. The results after treatment of the freshly ruptured ligaments were much better than the results of the treatment of chronic instabilities. A significant acute posterior instability should be operated.

Acute Disease↗
PubMedDate not supplied

Advances in treatment techniques and time/dose schedules in external radiation therapy of brain tumours in childhood.

Recent advances in radiotherapy techniques seek to improve the therapeutic ratio in childhood brain tumours by adding potentially more effective treatment in ways that will increase tumour control and limit radiation toxicity. Stereotactic irradiation techniques in conjunction with rigid head fixation systems comprising single high-dose delivery ("radiosurgery"), fractionated convergence therapy and three dimensional conformal therapy focus the dose to tumour while sparing surrounding normal tissue. Although these techniques are well established in adults data for childhood central nervous system malignancies are scarce. Preliminary data reveal low acute toxicity and promising results in recurrent tumours as well as in primary treatment. Whether stereotactic radiation therapy with either of the latter techniques will add substantially to disease control and preserve neurologic function remains to be established and should be part of future investigations. The introduction of quality control procedures assures precise radiotherapy of the tumour site, whole brain and craniospinal axis and is a prerequisite to improve survival and to reduce potential adverse effects. Hyperfractionated radiotherapy has the potential of increasing dose to tumour more safely theoretically sparing children some of the late effects while in particular in craniospinal irradiation. Pilot studies revealed excellent tumour control in medulloblastoma with acceptable acute toxicity. The strategy is part of the subsequent HIT '98 trial both for low and high risk patients. In conclusion, there is considerable enthusiasm among all those caring for children with brain tumours to study modifications of radiation delivery that may result in improved treatment. Rapid accrual to an increasing number of cooperative prospective trials is expected to provide the body of data supporting the selection of novel radiation therapy modalities in the future.

Adult↗
PubMedDate not supplied

Interleukin-2-dependent mechanisms are involved in the development of glomerulosclerosis after partial renal ablation in rats.

BACKGROUND: Glomerulosclerosis is a common feature of many end-stage renal diseases. The contribution of cellular immune mechanisms has been implicated in the development of glomerulosclerosis. We investigated whether the inhibition of lymphocyte activation influences this process in an established rat model of renal hyperfiltration. METHODS: After removal of two-thirds of their respective kidney mass, rats were treated with either tacrolimus (0.08 mg/kg/day) or vehicle until the end of the study (n = 10/group). The rats were pair-fed and proteinuria was assessed regularly. Twenty weeks after nephrectomy, creatinine clearance and systemic blood pressure were determined, and kidneys were harvested for morphological, immunohistological and PCR analysis. RESULTS: In control animals, renal function started to decline from week 12, as indicated by an elevated proteinuria. Interleukin (IL)-2 and IL-2 receptor synthesis was upregulated in control animals and inhibited by tacrolimus treatment. Transforming growth factor-beta (TGF-beta(1)), platelet-derived growth factor-AA (PDGF-AA) and macrophage chemoattractant protein-1 (MCP-1) mRNA levels were upregulated in control animals, but were significantly lower in immunosuppressed hosts. Additionally, tacrolimus treatment resulted in a significant reduction of proteinuria. Morphological analysis supported these functional results; glomerular sclerosis, tubular atrophy and intimal proliferation were more pronounced in controls than in the tacrolimus group. These morphological parameters were accompanied by reduced infiltration of CD5+ (rat T-cell marker) T cells, ED1+ (rat macrophage marker) macrophages, and less intense staining for laminin and fibronectin. CONCLUSION: A continuous treatment with tacrolimus - an inhibitor of lymphocyte proliferation - reduced the pace of glomerulosclerosis in the remnant kidney.

Animals↗
PubMedDate not supplied

Psychopathological symptoms of depression in Parkinson's disease compared to major depression.

Parkinson's disease is frequently associated with depressive symptoms. When depression occurs at early stages and before the onset of characteristic motor symptoms of the disease, differential diagnosis of major depression may be difficult. Differences in psychopathological features of depression in Parkinson's disease and major depression have been reported by some authors. This study presents data of 49 patients with depression in Parkinson's disease and 38 patients with major depression. The severity of depressive symptoms was equivalent in both groups. Depressive features did not differ between the two groups with exception of affective flattening, delusional ideas and suicide attempts. In conclusion, this investigation gives support to the assumption of a common neurobiological origin of depression in Parkinson's disease and major depression.

Affect↗
PubMedDate not supplied

Diagnostic and clinical outcome of neurogenic tumours in the head and neck area.

A retrospective analysis of diagnostic procedures and clinical outcome of patients with neurogenic tumours of the head and neck region was performed. There were 25 patients - 16 with neurinoma, 5 with neurofibroma and 4 with neurogenic sarcoma - who presented with a mass in the head and neck area. In 13 patients, the neurinoma originated from the facial nerve, 2 of them were located in the middle ear and mastoid and showed facial palsy. Four patients presented with neurofibromatosis type 1. Twenty-three patients were operated on to remove the tumorous masses. Eighteen tumours were assigned intraoperatively to a cranial nerve main trunk, whereas 7 tumours originated from small branches or showed diffuse growth in neurofibromatosis. All benign neurogenic tumours were removed totally without relapse. One of 2 auricular nerve autografts in middle-ear facial nerve neurinoma resulted in a sufficient muscle tonus of the face. Three patients with malignancies died within 12-24 months showing local recurrencies (n = 1) and/or pulmonary metastasis (n = 2). As expected, neurogenic tumours are unusual neoplasms of the head and neck regions. On the other hand, neurogenic malignancies exhibit diagnostic problems as well as uncertain chances for long-term survival. Tumour staging, determined by extension and critical for treatment decisions, is well evaluated by CT scan and MRI. A multimodal therapy regimen with operation and radiation is recommended for neurogenic sarcoma also when developing in neurofibromatosis. However, in main trunk neurinomas, nerve autografting with interposition is the therapy of choice with a good chance of functional recuperation.

Combined Modality Therapy↗
PubMedDate not supplied

Percutaneous jet ventilation.

A method of ventilation utilizing an S-shaped cannula placed through the cricothyroid membrane and hooked up to a conventional jetting system is described. Its advantages are reduced morbidity, better ventilation, and an unobstructed view of the operating site for the surgeon. The system allows ventilation of the patient with oxygen prior to the induction, or at the end of anesthesia if necessary, and allows the surgeon to perform a tracheostomy in the usual manner if it is indicated. The system is not proposed as a routine method of ventilation during anesthesia for laryngeal surgery but is reserved for cases in which other methods would not perform adequately.

Aged↗