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Biomedical subjects

M Wunsch

Publications and source records attributed to M Wunsch.

14 recordsLinked to original sources
PubMed2003

[Percutaneous radiofrequency ablation of liver tumors using the LeVeen 4 cm array probe].

BACKGROUND: The purpose of this study was to evaluate safety and efficacy of a radiofrequency ablation system in clinical practice. METHODS: In 35 patients (age 63,9 +/- 12,6 years, range 22 - 83) a total of 65 liver tumors were percutaneously treated using a 200 watt radiofrequency generator and a LeVeen 4 cm array probe (RF3000, Boston Scientific). The interventions were performed under CT guidance in local anaesthesia and sedation. Adapted to the tumor size, the LeVeen Probe was repositioned during the procedure with an additional safety margin of 1 cm. Primary tumors were colorectal in 22, and mamma tumors (n = 4), zystic pancreas tumors (n = 2), gastric cancer (n = 1), zystadenocarcinoma of the liver (n = 1), lung cancer (n = 1), gastrointestinal stroma tumor (n = 1), duodenal carcinoma (n = 1), cholangiocellular carcinoma (n = 1) and hepatocellular carcinoma (n = 1). Post interventional control and follow-up was performed with multislice-CT (collimation 2.5 mm, unenhanced and contrast enhanced, arterial and portal filling) at 4 weeks, and every three months. RESULTS: One to 4 metastases were treated per patient during one or up to 4 procedure sessions. Mean lesion size was 2,3 +/- 1,2 cm (range 0,2 to 7,0). The corresponding size of the necrosis achieved was 4,6 +/- 1,4 cm (range 2,0 - 8,2). Primary technical success with complete tumor ablation was reached in 60 of 65 lesions. In 4 cases two treatment sessions were necessary in order to achieve the intended results. In one case the procedure was aborted because of a close relationship between lesion and right colon. 63 tumors were treated in sedation and local anesthesia. General anesthesia was necessary in two cases, in one who refused intervention in sedation, and in another case with insufficient analgetic effect. Morbidity was 9.2 %: Bleeding complications (n = 3, one arterial bleeding from the ablation tract, two intrahepatic bleedings with extrahepatic hematoma) were confirmed by selective angiography of the hepatic artery and were treated with coil embolisation of the respective segmental arteries. One case with subcapsular tumor ablation suffered from a large subcapsular hematoma requiring a blood transfusion. In one case with a subphrenic location of the metastasis, the needle electrode had passed the costophrenic recessus and resulted in an hematothorax. This patient was treated by pleural drainage for two days. One patient suffered from fever up to 39 degrees C and inflammation of the biliary tract and received a cholecystectomy 22 days post interventionally. There was no peri interventional mortality. Mean follow-up is 5,6 +/- 3,3 months (range 0 to 13). 21 of 35 patients showed no evidence of tumor recurrence. One case is scheduled for a second treatment session for complete tumor ablation. 13 of 35 patients suffered from tumor recurrence, either local recurrences and/or new metastases. At the sites of prior RF-ablation 9 local recurrences were detected in 7 patients, two cases with isolated local recurrences and 5 cases with local recurrences and new metastases. 6 Patients showed no evidence for local recurrences but new metastases. In these 11 cases a total of 37 metastases were found at new locations. In three patients tumor recurrence was treated by means of a second RF-ablation. The remaining 10 patients received chemotherapy. CONCLUSION: RF-ablation can be performed in local anaesthesia and sedation with low peri interventional morbidity and mortality. Using the LeVeen probe and a 200 watt generator, appropriate necroses can be achieved. CT follow-up is required every three months because of the tumor recurrence rate and reinterventions may be required.

Adult↗
PubMed2001

Endoscopic exploration of Red Sea coral reefs reveals dense populations of cavity-dwelling sponges.

Framework cavities are the largest but least explored coral reef habitat. Previous dive studies of caverns, spaces below plate corals, rubble and artificial cavities suggest that cavity-dwelling (coelobite) filter-feeders are important in the trophodynamics of reefs. Quantitative community data are lacking, however, as the bulk of the narrow crevices interlacing the reef framework are inaccessible to conventional analysis methods. Here we have developed endoscopic techniques to explore Red Sea framework crevices up to 4 m into the carbonate rock, revealing a large internal surface (2.5-7.4 m2 per projected m2 reef) dominated by encrusting filter-feeders. Sponges alone provided up to 60% of coelobite cover, outweighing epi-reefal filter-feeder biomass by two orders of magnitude. Coelobite community filtration removed more than 60% of the phytoplankton in the course of its less than 5-minute passage through the crevices, corresponding to an uptake of roughly 0.9 g carbon m-2 d-1. Mineralization of the largely allochthonous organic material is a principal source of nutrients supporting coral and algal growth. The supply of new material by coelobites may provide a key to understanding the 'coral reef paradox'-a rich ecosystem thriving in nutrient-poor water.

Animals↗
PubMed1996

Biomechanical studies of transthoracic vertebral body replacement with autologous bone grafts (fibula and rib).

Thoracic processes which destroy vertebral bodies leave gaps which usually have to be bridged. The aim of our experiments was to find out whether rib and fibula grafts are suitable vertebral body substitutes from the biomechanical point of view. Therefore, we examined characteristics of vertebral body/bone graft/vertebral body arrangements under the influence of pulsating compression forces in a testing machine. The deformation of the rib graft alone was 0.78 mm under a preselected peak load of 1010 Newton. When the rib graft was placed between two vertebral bodies, the deformation (creeping) was 6 mm under a peak load of 1010 Newton. The deformation of the fibula graft alone was 0.41 mm, and when placed between vertebral bodies maximally 3 mm. The results of our experiments lead to the conclusion that ribs modified according to our design are prinzipally suitable for vertebral body replacement in the thoracic region as far as primary stress resistance is concerned. Characteristics of these bone grafts in the human body are being followed-up.

Biomechanical Phenomena↗
PubMed1991

Junior and senior faculty women: commonalities and differences in perceptions of academic life.

The purpose of this study was to explore the commonalities and differences in the perceptions of senior and junior faculty women regarding the barriers to success experienced early in academic careers. The population consisted of 22 pairs of junior and senior faculty women who participated in a mentoring program at a major public research university. Descriptive data indicate close agreement among junior and senior women faculty regarding the importance of the majority of potential barriers. Nonetheless, important differences exist. An exploratory factor analysis identified four underlying dimensions: personal security, work priorities, sense of belonging, and scholarly accomplishment. There was a significant difference between the two groups in their perceptions of personal security.

Adult↗
PubMed1989

[Intrauterine cerebral hemorrhage as a cause of hydrocephalus].

Intracranial haemorrhages in before-term children and risk newborn are a well-known problem, hydrocephalus being one of the possible posthaemorrhagic complications. In most cases intrapartal and postpartal complications will be responsible for the occurrence of haemorrhages. However, in this regard it is difficult to assess the ranking of individual factors such as acidosis, birth trauma, postpartal care and infusion therapy or postpartal complications. The following case report concerns a rare case of prepartal intraventricular bleeding resulting in hydrocephalus in an otherwise uneventful pregnancy course. Whereas in the 32nd pregnancy week both the cerebral ventricular system and the dimensions of the head had been normal, development of hydrocephalus was discovered at random in the 36th week during a screening procedure.

Adult↗
PubMed1984

[Bilateral pneumothorax following laparoscopy].

A case of laparoscopy is presented with postoperative large subcutaneous emphysema and bilateral pneumothorax. As a result of careful control, conservative treatment, and consequent oxygen administration, this life-threatening phenomena disappeared within a short time. Preventive measures for complications of diagnostic laparoscopy are discussed and established to lower the anaesthetic risk of this widely practised procedure.

Adult↗
PubMed1983

[Sonographic diagnosis of a large placental tumour in late pregnancy - case and consequences for delivery].

The article deals with the sonographic diagnosis of a large chorioangioma in the 34th week of pregnancy. In consequence of the fast growth of the tumour and development of an oligohydramnios a Caesarian section was carried out in the 36th week. The infant suffered with anaemia. We summarize the current literature and discuss the differential diagnosis as well as the consequences for delivery in conclusion of the diagnosis "placental tumour".

Adult↗
PubMedDate not supplied

Prevalence of cardiovascular disease risk factors in a southwestern Native American tribe.

A cross-sectional study was conducted among the Pascua Yaqui Indian tribe in Tucson, AZ, in 1990 to document the prevalence of cardiovascular disease risk factors. Cardiovascular disease is the leading cause of mortality for Native Americans and for members of the Pascua Yaqui tribe specifically. A total of 230 randomly selected adults, ages 25-65 years, who were listed as members on the tribal roll, participated, resulting in a 73-percent participation rate for those contacted. The five risk factors studied included diabetes, hypertension, hypercholesterolemia, obesity, and smoking. Only 14 percent of participants had none of the risk factors; 52 percent had two or more factors. Obesity was the most prevalent, being present in 69 percent of the women and 40 percent of the men, followed by diabetes, 35 percent of men and 39 percent of women. Twenty-six percent of the population had hypertension, and 43 percent of men were smokers, compared with 24 percent of women. Hypercholesterolemia was present in 19 percent of men and 14 percent of women. The rates of diabetes, obesity, hypertension, and smoking documented in this tribe are relatively high and can serve as a baseline for evaluating future prevention efforts.

Adult↗