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Biomedical subjects

O Wolf

Publications and source records attributed to O Wolf.

At least 19 recordsLinked to original sources
PubMed2007

Early endothelial and haematological response to cryoplasty compared with balloon angioplasty of the superficial femoral artery--a pilot study.

The purpose of the present study was to assess the course of adhesion molecules (intercellular adhesion molecule (ICAM), vascular cell adhesion molecule (VCAM), e-selectin, p-selectin and monocyte chemoatlractant protein 1 (MCP-1)), growth factors (transforming growth factor beta (TGFbeta) and basic fibroblast growth factor (bFGF)) and the cytokine tumour necrosis factor alpha (TNFalpha) after both angioplasty and cryoplasty. Recently cryoplasty has been suggested as a new method to oppose neointimal hyperplasia resulting in restenosis formation. While in vitro models have shown that the application of cryothermal energy to the endothelium during angioplasty leads to apoptosis induction and reduced proliferation rates, no human in vivo proof for an inhibition of neointimal hyperplasia exists. For restenosis initiation adhesion molecules, growth factors and cytokines play an important role. One possibility to investigate the endothelial response to angioplasty is the measurement of the soluble forms of adhesion molecules, growth factors and cytokines that are released into the circulation after denuding the vessel wall. In the present study we assessed the distribution pattern of the soluble forms of e-selectin, p-selectin, ICAM, VCAM, MCP-1, TGFbeta, bFGF and TNFalpha after angiography, angioplasty and cryoplasty of the femoropopliteal artery in the early course of 4 weeks in 29 patients with peripheral arterial occlusive disease. During the 4 weeks after intervention levels of e-selectin, ICAM, VCAM and MCP-1 increased after both angioplasty and cryoplasty. The course of the screened biomarkers was similar between angioplasty and cryoplasty. P-selectin and TGFbeta both decreased after cryoplasty, but not significantly. The present results show that the release of adhesion molecules, growth factors and cytokines is similar between balloon angioplasty and cryoplasty.

Aged↗
PubMed2006

MRI lesions after invasive therapy of carotid artery stenosis: a risk-modeling analysis.

BACKGROUND: Diffusion-weighted imaging (DWI) abnormalities can frequently be detected after carotid endarterectomy (CEA) and carotid angioplasty with stent placement (CAS) of the carotid arteries. We looked for possible predictors for the development of DWI lesions during the intervention. METHODS: We investigated 41 patients who underwent CAS without protection devices and 93 patients who underwent CEA. DWI studies were performed 1 day before and after the intervention. RESULTS: Ischemic complications consisted of two strokes (2.2%) in the CEA group and one stroke (2.4%) in the CAS group. DWI lesions were detected in 28.0% of all patients after intervention. Using a multivariate regression analysis, diabetes mellitus (DM), hyperlipidemia, symptomatic stenosis, age and CAS were found to be significant predictors for the occurrence of DWI lesions. CONCLUSIONS: DWI is an objective and highly sensitive method for monitoring interventions of the carotid arteries. Our results point to an increased risk of patients with diabetes and hyperlipidemia to develop DWI lesions during invasive therapy of the ICA.

Age Factors↗
PubMed2004

Frequency, clinical significance and course of cerebral ischemic events after carotid endarterectomy evaluated by serial diffusion weighted imaging.

OBJECTIVES: Neurological deficit defines the outcome of Carotid Endarterectomy (CEA) that is mainly caused by cerebral ischemia. Diffusion-weighted imaging (DWI) is a sensitive method for demonstrating even small ischemic lesions. The aim of this study was to evaluate the frequency, clinical significance and course of ischemic lesions after CEA using serial DWI. METHODS: DWI was performed within 1 day before and after CEA in 88 patients. Postoperative lesions were analyzed by their quantity, volume and distribution. To differentiate temporary ischemia from definite cerebral infarction (blood brain barrier disruption) all patients with a positive postoperative DWI were reexamined with contrast-enhanced T1-MRI 7-10 days after the procedure. All patients were examined by a neurologist within 2 days before and after CEA. RESULTS: Two patients showed a postoperative neurological deficit. Postoperative DWI revealed ipsilateral ischemic lesions in 15 patients. In seven of these patients a brain infarction was diagnosed on the T1-MRI during follow-up. A significant correlation between the number of DWI lesions (p=0.031) as well as the volume of DWI lesions (p=0.023) and definite infarction was found. Symptomatic patients preoperatively showed significantly more DWI lesions (p=0.036) and cerebral infarcts (p=0.003). CONCLUSION: DWI is a sensitive method of demonstrating ischemic events after CEA. The number and volume of DWI lesions after CEA are highly predictive of brain infarction.

Aged↗
PubMed2004

The density of epidermal p53 clones is higher adjacent to squamous cell carcinoma in comparison with basal cell carcinoma.

BACKGROUND: It is well accepted that ultraviolet radiation from the sun can induce and promote growth of skin tumours. Skin cancer develops as a consequence of multiple genetic hits, where an initial, important step includes proliferation of cells susceptible to malignant transformation. Foci of morphologically normal epidermal keratinocytes overexpressing p53 protein are common in chronically sun-exposed skin. Such foci have previously been shown to represent expanding clones of p53-mutated keratinocytes. Although several characteristics concerning epidermal p53 clones remain to be resolved, an important role in skin carcinogenesis is anticipated. The density of epidermal p53 clones in human skin is largely unknown. OBJECTIVES: To compare the occurrence of epidermal p53 clones in skin surrounding cancers with that in skin surrounding benign melanocytic naevi. To assess the influence of age on frequency and size of epidermal p53 clones in human facial skin. METHODS: We have analysed the number and sizes of epidermal p53 clones in skin specimens from patients with squamous cell carcinoma (SCC), basal cell carcinoma (BCC) and benign melanocytic naevi. Cases included normal facial skin from four different age groups. Tissue sections were immunohistochemically stained and the presence of p53 clones was recorded. Approximately 1.4 m of epidermis from a total of 112 biopsies was analysed. RESULTS: We found 128 epidermal p53 clones in biopsy specimens from 112 patients. The results showed that the number and size of p53 clones increase with age. In normal skin adjacent to SCC p53 clones were significantly more numerous and greater in size in comparison with those in normal skin both adjacent to benign naevi and adjacent to BCC. Interestingly, normal skin in the close vicinity of BCC and melanocytic naevi showed similar results regarding both number and size of epidermal p53 clones. CONCLUSIONS: Our findings suggest a connection between development of epidermal p53 clones and SCC.

Adult↗
PubMed2002

Endoscopy of intracranial cysts in the adult patient.

In this study we report about our experience in surgical therapy of patients with intracranial supratentorial cysts. The main interest herein lies in the difference between conventional surgery and the endoscopic approach. Since 1997 in the Unfallkrankenhaus Berlin 4 male and 4 female patients with intracranial cysts aged between 21 and 66 have been treated surgically. The intracranial endoscopy was performed in 6 patients. The initially complained, mostly unspecific, symptoms diminished post operatively and in the follow-up. As complications a transient hemiparesis and an aseptic bone necrosis have to be mentioned, the latter after use of conventional surgery. In clear diagnostic cases an operation of intracranial cysts seems appropriate. Both surgical methods, open and endoscopic approach, are appropriate. To avoid complications due to greater surgical wounds the endoscopic method should be preferred.

Adult↗
PubMed2000

Necrobacillosis in free-living male European bison in Poland.

In the Bialowieza Primeval Forest (Poland) a chronic disease of the external genital organs has been observed in free-living male European bison (Bison bonasus) since 1980. Investigations on this disease started in the late 1980s. The most striking findings are necrotic and ulcerative lesions of the prepuce and penis of bison aged from 6 mo to >10 yr. Histologic examination of tissue samples from the prepuce of six bison (9-mo- to 8-yr-old), and from the penis of two bison (3- and 8-yr-old), were characteristic of necrobacillosis. Masses of slender, Gram-negative, rod-like or filamentous bacteria occurred in necrotic tissue. At the periphery of necrotic tissue filamentous bacteria were often arranged in large clusters and strands that advanced towards healthy tissue. Immunolabeling and electron microscopy also suggest that these organisms are Fusobacterium sp.

Animals↗
PubMed1999

[First experiences using microsurgical techniques for minimally invasive ventral interbody fusion of the lumbar spine (MINI-ALIF)].

Minimal invasive techniques recently have become more important in spine surgery. Ventral approaches for lumbar fusion techniques are known for a long time. Their disadvantages are their size and the associated trauma. Since the early nineties two schools of minimal invasive procedures were developed. On one hand surgeons developed laparascopic methods, on the other hand traditional ventral approaches were minimized and combined with microsurgical techniques, in a way that they offer all advantages of minimal invasive procedures. This technique widely known under the acronym MINI-ALIF, which stands for MINImal invasive Antero-Lumbar Interbody Fusion, was developed for retroperitoneal approaches to the segments L2/3, L3/4, L4/5 and for the transperitoneal approach to the segment L5/S1. Its advantages include reduced technical and personnel effort, minimal traumatized tissue, low blood-loss, short operating times and reduced rates of complications. Additionally the surgeon does not need to be experienced in laparascopic methods. The operation technique is explained and discussed from the neurosurgical point of view.

Humans↗
PubMed1998

[Cystic echinococcosis of the spleen].

Based on the portal infection root, the hydatid disease of the spleen represents a rarity. Because of a lack of prospective studies, spleen-preserving procedures and splenectomies were published as surgical therapy in case reports. In this report, the case of a 72-year-old woman with symptomatic hydatid disease of the spleen will be reported. Surgical and pharmaceutical strategy to minimize the risk of an OPSI syndrome as well as the value of adjuvant therapy with Albendazole will be discussed.

Aged↗
PubMed1994

Endorectal ultrasound and leiomyosarcoma of the rectum.

Leiomyosarcomas of the rectum are uncommon neoplasms accounting for fewer than 1% of all malignancies of the colon and rectum. Approximately 215 cases have been described in the literature. Distinction from leiomyoma is often difficult, but regarding dignity is important. The case reported is that of a 68-year-old man in whom a 2.2-cm rectal mass covered by mucosa was diagnosed by rectoscopy and endorectal ultrasound. After treatment by wide local excision the histological specimen revealed a low-grade, highly differentiated leiomyosarcoma. Due to the lack of a large series of this disease, there is disagreement over the therapeutic strategy. At the moment a selective treatment approach seems to be the most frequently advocated. Large tumors and those extending beyond the rectal wall are treated by radical surgical resection. Leiomyosarcomas less than 2.5 cm in size and confined to the bowel wall can be treated by wide local excision. Endosonography can provide exact assessment of tumor size and expansion and is of great value in selecting the appropriate treatment.

Aged↗
PubMed1992

The traumatic dural sinus injury--a clinical study.

In a period of 13 years 978 cases of severe head injuries were operated on in our clinic. An analysis of the medical reports includes injuries of the superficial dural sinus (39 cases = 4%): among these injuries of the anterior and central part of the superior sagittal sinus (66 per cent), injuries of the transverse sinus (18 per cent), injuries of the posterior part of the superior sagittal sinus (8 per cent), and combined injuries of different dural sinuses (8 per cent). Clinical data, i.e. the causes of accident, radiological examination results, intracranial lesions, operation techniques and outcome are analysed and discussed. The analysis of cases with dural sinus injuries shows a high mortality rate (total mortality rate: 16 patients = 41%; intra-operative mortality rate: 8 patients = 20%).

Adolescent↗
PubMed1992

Drug rechallenge and patients' rights.

Challenging a hypersensitive patient with a potentially harmful drug is most important to the development of medical knowledge. However, it does not always serve the interest of the particular patient. In order to protect the interest of an individual patient, one must abstain from challenge unless it is vital to the health of the particular patient at the time and has no substitute. Patients' rights demand the establishment of limitations and guidelines for the procedure of rechallenge in all its aspects. An approach which will bring physicians closer to a solution, which will protect the patient from uncontrolled decisions and from unnecessary risks, is suggested.

Clinical Protocols↗
PubMed1991

Atherosclerosis in the aorta of hypercholesterolemic rabbits and the influence of daltroban.

These studies have examined aortic atherogenesis in cholesterol-fed rabbits and have correlated the effects of daltroban to the pathomechanism of the vessel wall lesions. After feeding a 0.5% cholesterol-enriched diet for 96 d atherosclerotic alterations were seen, which exhibited a proximo-distal pattern, to which the branching of the aorta contributed considerably. Depending on their localization and size a varying cellular constitution of the plaques was obvious. Large plaques, which were mainly seen in the aortic arch and the proximal descending thoracic aorta, consisted of numerous proliferating cells, masses of fibrillar ground substance, clusters of foam cells, and rarely contained cholesterol crystals and necroses. Emerging plaques mainly found in distal thoracic and abdominal aorta imposed as fatty streaks. Daltroban treatment, used in a clinically relevant doses of 10 mg/kg b. wt. per day, reduced extension and protrusional area of plaques to about 40%, which was evaluated using a newly developed computerized morphormetric method, in association with significant reductions in free cholesterol content within the aorta. The results suggest that daltroban inhibits the progression of atherosclerosis in cholesterol-fed rabbits. This effect may be related to its antagonistic interaction with the thromboxane A2 receptor and also to an inhibition of the cholesterol metabolism.

Animals↗
PubMed1991

[Results of multistep oxygen therapy in the treatment of sudden hearing loss].

Oxygen multistep therapy (von Ardenne) was applied in 28 patients suffering from an idiopathic sudden hearing loss. The oxygen therapy consisted of a multistep short procedure, each of which lasted for 15 minutes. The results of our study were evaluated by means of standardised statistics confirming the effectiveness and even the superiority of the oxygen multistep therapy in comparison with any other treatment, and also in view of the spontaneous remission rate in cases of sudden hearing loss.

Adult↗
PubMed1990

[Comparison of plethysmography findings before and following varicose vein surgery].

In the chronic venous insufficiency on the basis of a primary varicosis the occlusion plethysmography of the veins is a suitable remedy in the positioning trial before and after a combined phlebectomy to determine the capacity of the venous part of the circulation on the lower extremity. In altogether 160 patients the functional capacity of the venous valves with the initial inclination to swelling St as well as the capacity of the venous vascular system on the calf and the ankle were established by the determination of the maximal venous capacity Vmax. It could be proved that particularly in stage III of the chronic venous insufficiency the haemodynamically most effective efficacy can be achieved by an operation of the varices.

Female↗
PubMed1990

Chemotactic response of osteoblastlike cells to transforming growth factor beta.

Transforming growth factor beta (TGF-beta) has multiple effects on bone cell metabolism in vitro but its exact role in bone remodeling still needs to be defined. Here we demonstrate that TGF-beta is chemotactic for osteoblastlike cells from fetal rat calvariae and osteoblastlike ROS 17/2.8 osteosarcoma cells. Maximal chemotaxis occurred at 5-15 pg/ml of TGF-beta and was observed with TGF-beta 1 and TGF-beta 2 at equivalent concentrations. Conditioned medium from osteoblastlike cells containing latent TGF-beta failed to stimulate chemotactic migration. However, chemotactic activity was observed in conditioned medium that had been transiently acidified. Since acidification is known to activate TGF-beta, these results suggest that only active TGF-beta is capable of inducing a chemotactic response. Preincubation of osteoblastlike cells with TGF-beta in concentrations from 10 pg/ml to 1 ng/ml for 48 h abolished a subsequent chemotactic response of these cells to TGF-beta, indicating that TGF-beta-induced chemotaxis is a transient phenomenon. Since TGF-beta may be released from the bone matrix and/or activated during bone resorption, the chemotactic activity of TGF-beta for osteoblastlike cells may be important for the recruitment of osteoblastlike cells to sites of bone remodeling.

Animals↗