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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 145 records · Page 8Linked to original sources
PubMed1995

Transcranial Doppler and cortical microcirculation at increased intracranial pressure and during the Cushing response: an experimental study on rabbits.

The effect of increased intracranial pressure on the flow velocity of the basilar artery was measured with transcranial ultrasonic Doppler in New Zealand White rabbits under alpha-chloralose anesthesia and artificial respiration. Laser Doppler flowmetry served to study changes of the cortical microcirculation. The results confirm a high inverse correlation of the diastolic flow velocity, the pulsatility index, and the resistance index with the cerebral perfusion pressure (CPP). During acute intracranial hypertension, however, these parameters do not show a good correlation with the local cortical blood flow. The absence of a correlation was evident over a wide CPP range down to values of 35 mm Hg. Only at CPP values below this critical threshold is the microcirculation impaired. The threshold is reached at pulsatility index values of more than 2.0 and at resistance index values of more than 0.8. Therefore, transcranial Doppler indices permit the detection of critical reductions of microcirculatory blood flow. The Cushing reaction occurred with a constant time lag of 5.5 +/- 0.7 seconds after the loss of CPP. The Cushing reaction did not establish systolic blood flow, which remained below the functional threshold, as concluded from the temporary loss of somatosensory evoked potentials.

Animals↗
PubMed1995

Median nerve somatosensory evoked potentials in cervical syringomyelia: correlation of preoperative versus postoperative findings with upper limb clinical somatosensory function.

Median nerve somatosensory evoked potentials (SEPs) were recorded in 30 patients with cervical syringomyelia before and after surgery. The different SEP components were compared with clinical somatosensory findings. The N13 potential (generated in the dorsal horn at C5-C6) was pathological in 85% of the upper extremities, or 90% of the patients, and correlated with pain/temperature as well as vibration/joint position sense; it was of higher sensitivity in syringomyelia than any other clinical symptom or SEP component. P14 (brain stem) and N20 (postcentral cortex) were less often affected and correlated with only vibration/joint position sense. Short-term postoperative clinical or SEP changes were most often seen after syringoendoscopy and less often after syringostomy, resection of cerebellar tonsils, or tumor extirpation. Alterations of SEPs after surgery occurred in more patients (60%) than did changes in clinical condition (approximately 27%); there was, however, no general correlation between these findings. We conclude that median nerve SEP testing with a proper recording technique identifying the different subcortical components is a valuable supplement in the pre- and postoperative diagnostic evaluation of syringomyelia and is of higher sensitivity than clinical somatosensory examination alone.

Adult↗
PubMed1995

Fluvoxamine. A review of global drug-drug interaction data.

The overall reporting rate of drug-drug interactions with fluvoxamine is very low: only 73 cases have been identified from an estimated exposure of over 8 million patients worldwide. The reporting rate is similar in men and women, and most events relate to the use of fluvoxamine in conjunction with psychotropic compounds and anticoagulants. Two deaths have been documented. One involved a female patient who was given concomitant tryptophan and reportedly developed neuroleptic malignant syndrome. The causative role of fluvoxamine/tryptophan interaction in this case is unknown. The other reported death was considered to be unrelated to fluvoxamine. Fluvoxamine interactions with anti-epileptic or antidepressant drugs resulted in elevated plasma concentrations of the target drug and/or clinical symptoms, while interactions with neuroleptic or anticoagulant agents mostly resulted in clinical symptoms. Fluvoxamine increased plasma concentrations of tricyclic antidepressants by varying extents, particularly those of clomipramine (maximum reported increase 8-fold). Generally, clinical symptoms were infrequent and varied widely; no symptom clusters were identified. Those agents metabolised by cytochrome P450 1A2 isoenzyme appear most likely to be involved in drug-drug interactions with fluvoxamine.

Animals↗
PubMed1995

[Hemiprosthesis in femoral neck fracture].

From 1968 to 1993 835 hemiarthroplasties were performed at the Department of Trauma Surgery of the University of Erlangen. Until 1984 Moore (297) and Thompson (148) prostheses were implanted. After this period 390 patients were treated with a bipolar headneck replacement. Average age of patients at the time of surgery was 80.2 years from 1968 to 1980 and 83.1 from 1981 to 1993. All hemiarthroplasties were performed due to intracapsular fractures of the femoral neck. 5.9% of the Thompson and Moore prostheses were revised to total hip arthroplasty, the rate of revisions of bipolar prostheses was 4.9%. Main causes of revision for Thompson and Moore prostheses were acetabular erosion and protrusion (5.2%). Revision of bipolar prostheses became necessary because of recurrent luxation in 4.1%. The social status of the patients was examined 1 year after the operation. From 1968 to 1980 67% of the patients lived in their own home or with their families, compared to 39% from 1981 to 1993. The percentage of patients in retirement homes tripled from 9% to 29% for the same period.

Activities of Daily Living↗
PubMed1995

[Surgical tooth reconstruction in conjunction with irradiation of malignant tumors].

An infected osteoradionecrosis (IORN) is one of the most problematic sequelae of radiation in the course of cancer treatment in the head and neck. To prevent this, prophylactic dental extractions have been demanded before radiation, as well as specific measures (epiperiostalplastic cover, perioperative antibiotic treatment) if a tooth has to be extracted after the radiation treatment has been carried out. From 1980 until 1993, 812 Patients who had to be irradiated underwent a prophylactic dental extraction programme. Only in 0.5% of these cases an infected osteoradionecrosis developed later on. 167 patients were treated after the radiation had been applied, using perioperative antibiotic treatment and meticulous soft tissue cover following epiperiostal preparation of the gingiva. In spite of 25% of localised dehiscences no immediate infection of the bone was observed. At the same time 53 infected osteoradionecrosis were treated, 43% of which were of dental origin. Most of these were seen in the lower molar area. The results show the high value of prophylactic dental extractions before radiation as well as the benefit of careful extractions with epiperiostal gingival cover, after the radiation treatment, especially in the area of the posterior lower alveolus.

Head and Neck Neoplasms↗
PubMed1995

[Neoadjuvant radiochemotherapy in locally advanced non-small cell bronchial carcinoma. Initial results of a prospective multicenter study].

PURPOSE: In the last years new encouraging methods in the therapy of bronchial carcinoma have been elaborated. The early stages of bronchial carcinoma are still a domain of operative treatment. The long-term results of surgical treatment for locally advanced disease are considered to be unfavourable. Multimodal treatment concepts with simultaneous or consecutive application of radio-chemotherapy followed by surgical resection seem to reveal improved possibilities of therapy. PATIENTS AND METHODS: General treatment consists of 2 blocks of neoadjuvant chemotherapy with carboplatin, ifosfamide and etoposide, followed by a third course, consisting of carboplatin and vindesine. Simultaneously with the third course a hyperfractionated, accelerated radiotherapy with a single dose of 1.5 Gy 10 times per week is applied. The total dose is 45 Gy in 3 weeks, given at least to the 80% isodose. After restaging, tumor resection is carried out. Patients without tumor are randomized for prophylactic brain irradiation. RESULTS: From January 1992 up to 1.10.1993 25 patients have been treated in accordance to the study. All tumors were locally advanced (stage IIIa and IIIb). Until 1.10.1993 4 patients died, 2 of them certainly related to the tumor. Thirteen patients have been resected after neoadjuvant treatment. In 11 of these cases a R0-, and in 2 cases a R1 resection has been carried out. Tumor cells have been found only in 5 histologies. The hematotoxic side effects under competing RTX/CTX seemed to be unproblematical (RTOG/grade II). Problems occurred with 4 cases of serious esophagitis (RTOG/grade III to IV) and 2 cases of pneumonitis with 1 case ending lethally. CONCLUSION: Preliminary results of our study show the feasibility of multimodal treatment. A favourable 1-year survival rate after aggressive multimodal therapy and a high resection rate in previously unresectable patients could be demonstrated.

Adenocarcinoma↗
PubMed1995

[Intraoperative radiotherapy (IORT) in malignant brain tumors].

PURPOSE: Feasibility and morbidity of IORT for malignant brain tumors as well as value of innovative imaging for diagnosis of rest tumors and recurrences were examined. METHODS AND MATERIALS: Between May 1992 and November 1993, 23 patients with malignant brain tumors were treated in Münster with IORT. The patient collective was heterogeneous and negatively selected, i.e. beside of primary treatments, also patients with extensive previous treatment, recurrent tumors or metastases were included. Therapy consisted of radical surgical resection and intraoperative electron radiotherapy using total doses from 15 Gy to 25 Gy relative to the 90% isodose. Afterwards, patients without prior treatment underwent percutaneous irradiation with a maximum dose of 60 Gy, related to the small volume of the tumor area plus a safety margin of 2 cm. RESULTS: No increase of peri-operative morbidity or subacute sequelae was observed. Overall 1-year survival was 67% for grade III gliomas (WHO), and 56% for glioblastoma multiforme. When the Matsutani selection criteria (primary therapy of a supratentorial, peripheral astrocytoma grade III or glioblastoma smaller than 5 cm in diameter with a Karnofsky performance index of more than 60% and possible wide resection) were applied, 1-year survival increased to 75%. Nuclear medical diagnostics using 123I-alpha-methyltyrosin SPECT proved a valuable method for imaging of non-resectable tumor tissue and diagnosis of recurrences. CONCLUSIONS: The results of this study indicate that IORT can contribute to successful tumor treatment while neither increasing peri-operative morbidity nor subacute sequelae.

Adult↗
PubMed1995

[Endoluminal HDR brachytherapy in the palliative treatment of patients with the recurrence of a non-small-cell bronchial carcinoma after prior radiotherapy].

PURPOSE: The preferred primary treatment in non-small cell lung cancer is surgical resection. In fact, only less than 25% of patients are resectable with curative intent. The remaining patients are primarily treated with radiation therapy or combined radiochemotherapy, achieving remission rates up to 60% but 5-year survival rates of only about 5%. Therefore an effective palliative treatment is important. The aim of our study was to show that using intraluminal HDR brachytherapy, tumor-induced bronchial obstruction and its symptoms can be relieved in the majority of cases. PATIENTS AND METHODS: Sixteen patients with recurrent previously irradiated non-small cell lung cancer were treated with intraluminal high dose rate iridium-192 afterloading irradiation at the Department of Radiotherapy and Radiation Oncology of the University of Münster between 1989 and 1993. There were 15 men and 1 woman with a median age of 61 years. As a primary treatment, 50 to 60 Gy had been delivered percutaneously. The recurrences were treated with HDR brachytherapy using 2 to 4 applications of 5 Gy to 6 Gy each to a tissue depth of 0.5 cm. RESULTS: In 13 of 16 patients dyspnoea could be improved and in 15 of 16 patients atelectasis could be dissolved. Nine of 16 patients achieved a partial or complete remission evaluated by bronchoscopic criteria. The median period of remission was 4 months. The median survival time, measured from the start of therapy and analysed using the Kaplan-Meier method, was only 9 months. As side effects, 1 pneumothorax and 1 tracheomediastinal fistula occurred, the latter presumably related to tumor progression. CONCLUSION: Our results show the importance of intraluminal HDR brachytherapy in the palliative treatment of patients with recurrent non-small cell lung cancer.

Adenocarcinoma↗
PubMed1994

[The long-term functional results following velopharyngoplasty as a speech-improving measure].

Forty three out of 148 patients who had undergone velopharyngeal flap graft between 1980 and 1992 to treat velopharyngeal insufficiency, and for whom pre- and postoperative data were available, were studied for the purpose of determining the long term morphological functional results of the treatment. Almost all of the 43 patients (93.5%) had received a velopharyngeal flap graft according to Sanvenero-Rosselli. The remaining 4.7% had received a velopharyngeal adhesion according to Stellmach. Four physicians from the fields of oral surgery, orthodontics, phoniatrics, and logopedics evaluated the pre- and postoperative data as well as the results of the follow-up examination according to subjective criteria from their respective disciplines. All four physicians judged that following velopharyngeal flap graft a gradual improvement in the ability to speak had been achieved in 86% of the patients in the follow-up study. At the time of the follow-up examination 70% of these cases were judged to have achieved a "good" qualitative level of articulation and 21% were judged to have achieved a "usefull" level. The best results were obtained in patients who had been operated on before the age of six. The reason is that in these young patients muscular malfunction and pathological movement patterns can be more easily modified than in older patients. In many cases additional speech improvement was achieved through logopedic therapy following the velopharyngeal flap graft. In the most difficult cases intensive therapy while the patients were still hospitalized proved to be especially effective.(ABSTRACT TRUNCATED AT 250 WORDS)

Cleft Lip↗
PubMed1994

Caesarean section in a diabetic patient with a recent myocardial infarction.

This is a report of a 38-yr-old parturient with multiple medical problems including diabetes mellitus, bronchial asthma, chronic myelogenous leukaemia, pre-eclampsia and a recent myocardial infarction. After medical management in the coronary care unit, it was decided to proceed with a Caesarean section. The choice of anaesthetic was made by the patient and had to be modified in accordance with her medical condition. Cardiovascular monitoring included PA catheterisation and transoesophageal echocardiography. A general anaesthetic was performed using fentanyl, thiopentone and succinylcholine. The outcome was satisfactory for both parturient and baby.

Adult↗
PubMed1994

Biochemistry and molecular genetics of Leishmania glucose transporters.

Glucose is utilized as a significant source of metabolic energy by Leishmania parasites. This sugar is accumulated by the parasite via a specific carrier-mediated transport system located in the parasite membrane. Parasites may also contain another transporter that shuttles glucose between the cytoplasm and the glycosome, a membrane-bound organelle where the early steps of glycolysis occur. The transport systems of both the insect stage promastigotes and the intracellular amastigotes have been characterized and shown to have kinetic properties that are consistent with the different physiological environments of the insect gut and the macrophage phagolysosome. Several genes have been cloned from Leishmania species which encode proteins with substantial sequence similarity to glucose transporters from mammals and lower eukaryotes. Two of these genes are expressed preferentially in the promastigote stage of the life cycle, where glucose is more readily available and more rapidly transported and metabolized than in the intracellular amastigotes. One of these two developmentally-regulated genes has been functionally expressed in Xenopus oocytes and shown to encode a glucose transporter. A third gene encodes a protein that is also a member of the glucose transporter family on the basis of sequence similarity and proposed secondary structure. However, the significant differences between this protein and the other two suggest that it is likely to transport a different substrate. Functional expression will be required to define the specific biochemical role of each gene within the parasite.

Animals↗
PubMed1994

Fluvoxamine. A review of its safety profile in world-wide studies.

Fluvoxamine, a selective serotonin reuptake inhibitor, was studied extensively in 34,587 predominantly depressed patients in 66 studies conducted world-wide. These studies were largely uncontrolled trials representing the use of fluvoxamine by psychiatric and general practice physicians in everyday conditions. The safety data were analyzed according to standardized medical review and data management policies. Approximately 70% of the fluvoxamine population were female and 44% were aged 31-51 years. The modal total daily dose was 100 mg. Safety findings revealed a pharmacological adverse event profile similar to that seen with other serotonin reuptake inhibitors. Nausea was found to be the only common symptom, with an incidence rate of 16%. Approximately 2% of the fluvoxamine population reported at least one serious adverse event (per FDA criteria). Overall suicidality rates of fluvoxamine were found to be low (0.7%). No cases of zimelidine syndrome, bleeding syndrome or Guillain-Barré syndrome were identified. Overall, fluvoxamine was found to be safe and well tolerated suggesting a favorable alternative in the treatment of depression.

Adolescent↗
PubMed1994

Highly selective vagotomy in the rat: effects on bone and mineral metabolism.

Highly selective vagotomy (HSV) or sham operation was performed in male rats. Fifteen weeks later bone mineralization, fractional intestinal absorption and balance, urinary excretion, and serum levels of calcium, magnesium and phosphorus, together with serum gastrin, parathyroid hormone, calcitonin, vitamin D metabolites, osteocalcin, isoenzymes of alkaline phosphatase, and the urinary excretion of cyclic AMP and hydroxyproline were assessed. HSV induced chronic hypergastrinemia and enhanced the weight of the fundus, antrum, and pancreas. Body weight, food intake, intestinal absorption, mineral balance, and bone mineralization were unaffected by HSV, whereas serum parathyroid hormone levels and urinary hydroxyproline excretion were increased. It is concluded that in the rat 1) HSV has a trophic effect on gastric and extragastric tissues; 2) gastric acid production is not a major determinant of intestinal calcium absorption; and 3) normal bone mass in the presence of signs of hyperparathyroidism indicates an intrinsic capacity of HSV to interfere with calcium metabolism, probably via hypergastrinemia, gastrin being an element of the gastro-parathyroid axis. Our present findings underscore the fact that osteopenia after HSV in man may be a rare finding, but it cannot be ruled out that bone disease found after partial or total gastrectomy may be due in part to concomitant vagotomy.

Animals↗
PubMed1994

Intraoperative SEP monitoring in neurosurgery around the brain stem and cervical spinal cord: differential recording of subcortical components.

The results of intraoperative monitoring of median nerve somatosensory evoked potentials (SEP's) were evaluated in 75 neurosurgical patients in order to assess the role of differential derivation of brain stem (P14) and spinal cord (N13) wave activity. These components were compared with the conventionally recorded neck potential ("N13") that reflects overlap of P14 and N13. The spinal cord N13 wave was recorded from the posterior to anterior lower aspect of the neck and the brain stem P14 wave from the midfrontal scalp to the nasopharynx; both derivations enabled isolated low-artifact recording of these components. In 18.7% of patients, moderate to major latency and/or amplitude shifts of N13 or P14 were found that were masked in conventional neck-scalp recordings of "N13". There was a 6.7% false-negative rate in this series. Using a neck-scalp derivation alone, a 14.7% false-negative rate would have resulted and an isolated worsening of the P14 component (with stable neck potential) in six cases would have been overlooked. It is concluded that the proposed SEP recording technique allows independent assessment of spinal cord and brain stem activity. It is, therefore, superior to the conventional neck-scalp derivation technique, in which important information may be concealed or even lost due to the overlap of the brain stem P14 and spinal cord N13 potentials.

Adolescent↗
PubMed1994

[The radiotherapy of hyperplastic heterotopic ossification in osteogenesis imperfecta. 2 case reports].

PURPOSE: Osteogenesis imperfecta is a rare hereditary disease of connective tissue with a genetic defect in collagen synthesis. In osteogenesis imperfecta hyperplastic heterotopic ossification can be induced by hyperplastic callus formation caused by trauma or operation. Heterotopic ossifications can be found in numerous benign diseases. The successful use of low dose radiotherapy in the treatment of heterotopic ossifications is well-known from the literature. PATIENTS AND METHODS: We treated two children (a 13-year-old girl and a ten-year-old boy) with heterotopic ossifications of the lower extremities in osteogenesis imperfecta type IV (Lobstein) with a low dose irradiation (10 x 1 Gy, respectively 6 x 1 Gy) under megavoltage conditions. RESULTS: After radiotherapy the children were painfree and the hyperplastic callus was considerably reduced. The previously immobilized patients could partly be mobilized. Thereby it could be contributed to the rehabilitation of the patients. New hyperplastic callus formation was not observed in the irradiated areas so far. CONCLUSION: Analogous to the successful radiation of heterotopic ossifications in other benign diseases radiation therapy seems to be a successful treatment of hyperplastic callus formation in osteogenesis imperfecta. Despite the late risks of radiotherapy radiation treatment of benign diseases in children might be indicated.

Adolescent↗