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Biomedical subjects

G Kauffmann

Publications and source records attributed to G Kauffmann.

At least 19 recordsLinked to original sources
PubMed1998

Molecular cloning of genes differentially regulated by TNF-alpha in bovine aortic endothelial cells, fibroblasts and smooth muscle cells.

OBJECTIVE: Tumor necrosis factor-alpha (TNF-alpha) is a pleiotropic-cytokine binding to and thereby stimulating vascular cells. TNF-alpha mediated intermediate stimulation of vascular cells is believed to play a pivotal role in the development of arteriosclerosis. While extensive information has recently become available on gene induction by TNF-alpha, less is known about gene suppression by TNF-alpha in vascular cells. Endothelial cells are the first cell layer within the vessel wall interacting with circulating, cytokine releasing cells. Therefore, they were selected as target for these study. METHODS: A differential screening approach has been used to isolate cDNAs whose abundance was suppressed by incubating bovine aortic endothelial cells (BAEC) for 6 h with 1 nM TNF-alpha. The gene expression of 6 isolated cDNAs after TNF-alpha was investigated by dot blots and nuclear run-on analysis in BAEC. The investigated genes were partially or completely sequenced. Differential expression after TNF-alpha stimulation of BAEC, bovine fibroblasts and vascular smooth muscle cells (SMC) was studied by Northern blots. RNA transcripts of the clone C7 in aortic aneurysms were examined by in situ hybridization. RESULTS: 49 independent cDNAs were isolated by the differential screening approach and 6 clones were further analyzed. These genes were downregulated in a time and dose dependent manner in BAEC. Sequence analysis revealed that 3 cDNAs encoded previously unidentified genes (C1, C5, C7), while 3 encoded known genes: connective tissue growth factor (CTGF; A1), fibronectin (A8) and the mitochondrial genome (B1). A1 and B1 were suppressed in BAEC, fibroblasts and SMC, whereas A8, C1, C5 and C7 were not uniformly downregulated in the investigated cells. C7 RNA transcripts were exclusively induced in the endothelium of an uninflamed aortic aneurysm. The transcripts were undetectable in an inflamed aortic aneurysm and control vessels. CONCLUSIONS: Gene suppression is a prominent feature of the intermediate effect of TNF-alpha on endothelial cells. Differences in the expression of the tested genes in endothelial cells, fibroblasts and vascular smooth muscle cells open possibilities for the study of cellular interactions in the vascular wall in disease situations with high local TNF-alpha concentrations.

Animals↗
PubMed1996

Diagnostic accuracy in remote expert consultation using standard video-conference technology.

An international multicenter study (Germany, Sweden, and Switzerland) was performed to investigate the feasibility and diagnostic reliability of standard video-conferencing (VC) technology for remote expert consultation in radiology. Three high-spatial-resolution films (hand-bone, mammography, chest) and two low-spatial-resolution image sets (liver CT and MRI) were studied (total 446 images taken from different examinations). The images were recorded by a video camera, transmitted via public broadband networks, and displayed on a video monitor. The resolution of the recorded images varied from 2.4 lp/mm to 4.8 lp/mm at maximum zoom. After 3-4 months, the images were reexamined using conventional light-box reading. Diagnostic reliability was evaluated by receiver operating characteristics (ROC) analysis. With video conferencing, there was a noticeable loss of diagnostic accuracy for the high-spatial-resolution films, whereas for liver CT and liver MRI images VC reading seemed to be satisfactory (average area value difference < 0.02).

Feasibility Studies↗
PubMed1996

[Therapeutic efficiency of of pulsed spray lysis in peripheral arterial occlusions].

PURPOSE: To determine the clinical efficacy of pulse-spray thrombolysis. MATERIAL AND METHODS: In a prospective trial 28 patients with acute arterial (n = 14) and bypass (n = 14) occlusions of the lower extremities were treated with pulse spray thrombolysis. 23/28 legs were at risk. RESULTS: Technical and clinical success were 89% and 68% respectively. Time interval until restitution of antegrade flow was less than two hours, the median duration of the complete intervention was 17 hours. Two patients (7.1%) needed transfusions for inguinal haematomas. After six months 50% of occluded segments remained patent, secondary patency is comparable at 53%. Bypasses show significantly lower patency (p = 0.04) and higher amputation (p = 0.009) rates than native arteries. Bad run-off (< or = 1 artery patent) is a significant predictor for clinical failure and early amputation. CONCLUSIONS: The distinct advantage of pulse-spray thrombolysis is fast restoration of antegrade flow and thereby effective treatment of acute ischaemia. The complication rate is low without associated mortality.

Adult↗
PubMed1996

[Percutaneous therapy of malignant obstructive jaundice using expandable metal stents: a prospective study of 92 patients].

PURPOSE: To evaluate the clinical efficiency of percutaneously placed metallic stents in patients with malignant biliary obstruction. PATIENTS AND METHODS: In a prospective study 92 consecutive patients with malignant biliary obstruction were treated percutaneously with expandable metallic stents. Technical and clinical parameters during the procedure and regular follow-up were evaluated. RESULTS: Technical and clinical success rates were 100 and 91% respectively. During stent implantation we observed no severe complications. 30-day morbidity and mortality were 12 and 13% respectively. Late complications occurred in 35%, in 20.7% due to reocclusion of the bile ducts which was treated successfully in 17/19 patients. 75% of patients benefited from the procedure. Primary and secondary patency were 79.3 and 97.8%, respectively. CONCLUSIONS: Percutaneous transhepatic implantation of expandable metallic stents is a reliable and safe therapy for malignant jaundice and has a definite positive impact on the patients quality of life.

Adult↗
PubMed1991

[Objective assessment of disorders of visual perception following unilateral vestibular loss. Studies of the so-called Dandy symptom].

Visual ability and compensatory eye movements during defined vertical oscillation were investigated in 20 patients with unilateral lesions of labyrinthine function and in 20 normal subjects. Oscillation frequencies were performed at the rate of 1 to 1.5 Hz with an amplitude of 5 cm, comparative to head locomotions of a running person. In synchronism with this, the visual function was tested with Landolt rings. Patients complaining of subjective visual disturbance during walking and running, also presented a measurable blur of vision under test conditions. In addition, eye movements were recorded and classified into three types. However, these eye movements showed no relation to gaze function. Our results suggest that the otolith-ocular reflex may participate in adjusting the vertical eye position during vertical stimulations at low frequencies. The effect of visual disturbances in patients with labyrinthine lesions is explained by the "efference-copy" initially described by von Holst. The efference-copy is responsible for the neutralisation of provoked retinal perceptions.

Adult↗
PubMed1991

[Combined intra-arterial chemotherapy and radiotherapy in inoperable non-small cell bronchial carcinoma].

The five years survival rates of patients with non-operable non-small cell lung carcinoma are between 6% and 9%. Multiple attempts have been made to improve the response rate and the survival of these patients with different chemo- and radiotherapy schemes. The systemic chemotherapy with cisplatin-vindesine is until now one of the most active treatments with a response rate of 40%, but it is limited because of its side effects and toxicity. Eleven patients are treated one to four times with an intraarterial infusion of 3 mg/m2 vindesine and 20 mg/m2 cisplatin into the tumor-feeding bronchial artery combined with a simultaneous radiotherapy (60 Gy). Until now no major side effects occurred and the systemic toxicity was insignificant. An objective tumor response was encountered in 7/11 patients. The intraarterial chemotherapy combined with radiotherapy is strictly local and therefore effective especially in patients with limited or locally advanced disease.

Adenocarcinoma↗
PubMed1990

[Value assessment of the MIRA (multichannel infant reflex audiometry) hearing evaluation with and without biofeedback. 3. Diagnosis from curves or behavioral observation?].

Basing on the results of behavioural audiometry, MIRA (Multichannel Infant Reflex Audiometry) with and without biofeedback as well as in several cases also from the ABR, the authors demonstrate the advantages of the combination of curve analysis with behavioural observation compared with isolated looking at physiological curves or at the behaviour. The results were obtained from 100 babies in their first year of life accepted in sequence for testing their hearing; nearly one half of them had considerable hearing risks, most of them having been subjected to several different hearing tests.

Arousal↗
PubMed1987

[Microangiographic findings in experimental intestinal anastomoses].

Microangiography of anastomosis at the rat colon and the pig jejunum did reveal the postoperative state of vessel regeneration. Findings for evaluation were avascular areas, dislocation and dilatation of vessels, vessel break, vessel-anastomosis to the opposite site and to adhesions as well as the complete regeneration of the vessel architecture. A suture technique leading to correct apposition of the wound edges without destroying the circulation will be followed by an almost complete regeneration of the vessel architecture.

Animals↗
PubMed1987

[Assessment of a hearing test procedure, the MIRA (Multichannel Infant Reflex Audiometry) and biofeedback. 2. Influences on threshold determination].

Four years of experience with the hearing tests for babies MIRA (electrical registration of sucking, breathing and localisation reactions, respectively, due to acoustic stimuli with following evaluation of the curves) and biofeedback (1 1/2 years of experience, frequency modulation of the stimulus by the sucking activity and thus examination of the interaction between articulation and hearing) show different kinds of influence on the threshold determination. These are, in the first year of life, influences of a physical nature (room acoustics, audiometric apparatus and activity transducers) and of organisation and action (taking care of the babies, problems arising from simultaneous action and observation), as well as of different weighting of the number of reactions. These are compared with each other in respect of the reactions they provoke, rated individually, and discussed.

Age Factors↗
PubMed1986

Cerebrospinal fluid pressure alterations in experimental communicating hydrocephalus. Response of cerebrospinal fluid pressure to increase in arterial carbon dioxide tension.

The response of cerebrospinal fluid (CFS) pressure to increased arterial carbon dioxide tension (PCO2) was evaluated in 5 control animals and 7 animals with experimentally induced communicating hydrocephalus. The CSF pressure in control dogs increased moderately in response to PCO2; in dogs with hydrocephalus, an increase in PCO2 produced a pronounced increase in CSF pressure accompanied by a simultaneous decrease in cerebral perfusion pressure. Progression of hydrocephalus can be explained by increased intracranial pressure, periventricular edema and cerebral ischemia.

Animals↗