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Biomedical subjects

M Walter

Publications and source records attributed to M Walter.

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

[Traumatic aneurysm of the superior mesenteric artery as the cause of massive upper gastrointestinal hemorrhage].

Vascular malformation and aneurysmal disease of visceral arteries usually exhibit diagnostic problems in upper GI bleeding. In the presented case recurrent massive bleeding caused by an superior mesenteric artery aneurysm was a serious diagnostic and therapeutic challenge. Interventional embolization of the sacciform aneurysm led to a successful treatment and a favourable outcome.

Adult↗
PubMed1995

[An arteriovenous fistula in an unusual site].

Arteriovenous fistulas are caused by trauma as well as iatrogenic, the latter especially being facilitated by the increasing frequency of invasive diagnostic and interventional procedures. We report the case of an arterio-venous fistula between the 9th arteria intercostalis and the 9th vena intercostalis caused by computed tomography guided small needle aspiration of a pleural tumor.

Adult↗
PubMed1995

[Aortocolic fistula as a rare complication of aorto-iliac aneurysms].

Primary aortocolic fistula is a rare complication of infrarenal abdominal aortic aneurysm. Many case reports have been published along with small series but the incidence of primary aortocolic fistulae remains unknown. In contrast, the incidence of secondary aortocolic fistulae increases approximately up to 1.5-4.0% as a result of rapid evolution of aorto-iliac vascular reconstruction with prosthetic grafts. The prognosis of aortocolic fistulae mainly depends on the time interval between first clinical manifestations and operative treatment. Loss of time by detailed preoperative investigations worsens the critical situation of the patient. The high mortality is mainly due to the sequelae of hemorrhagic shock, and in a lesser degree to graft infection. Therefore the principal operative treatment is to stop bleeding in order to reduce the sequelae of hemorrhagic shock. The method of choice for vascular reconstruction is the extra-anatomic axillobifemoral bypass as a time-saving and uncomplicated operation to avoid fatal graft infection and to ensure sufficient arterial blood supply to the lower limbs. Any enteral bleeding of patients with aorto-iliac aneurysm or with a history of aorto-iliac prosthetic substitution has to be considered as an aortointestinal or an aortocolic fistula until the opposite is proven. This consideration is decisive for the prognosis of aortocolic fistulae. The operation treatment of all diagnosed aorto-iliac aneurysms, as well as the ultrasound control of all aorto-iliac prosthetic reconstructions, are possible preventive measures.

Aged↗
PubMed1994

The high density lipoprotein- and apolipoprotein A-I-induced mobilization of cellular cholesterol is impaired in fibroblasts from Tangier disease subjects.

Tangier disease (also known as familial HDL-deficiency) is characterized by very low high density lipoprotein (HDL) plasma levels, splenomegaly, and massive cholesteryl ester accumulation in the cytoplasm of various cell types. Since this phenotype may in part be caused by a defect in the pathway mediating cholesterol efflux from peripheral cells, we investigated the HDL3-mediated mobilization of cholesterol synthesized de novo from [14C]-mevalonolactone in cultivated fibroblasts from two patients with Tangier disease. Our results indicate that the HDL3-induced translocation of [14C]-cholesterol from intracellular pools to the plasma membrane and its subsequent secretion into the extracellular medium was approximately 50% less in the cells from the patients than in controls. The same result was also obtained with artificial apolipoprotein A-I-containing phospholipid vesicles. By contrast, no significant difference in HDL3-induced cholesterol efflux was observed when plasma membrane was labeled with exogenous [14C]-cholesterol. We conclude that inefficient cholesterol efflux in Tangier disease is primarily caused by impaired HDL3-induced activation of cholesterol translocation from intracellular pools to the plasma membrane.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1994

Regioselective synthesis of new sucrose derivatives via 3-ketosucrose.

3-Ketosucrose (alpha-D-ribo-hexopyranosyl-3-ulose-beta-D-fructofuranoside), obtained from sucrose via microbial oxidation with Agrobacterium tumefaciens, was shown to be an appropriate and versatile synthon for regioselective syntheses. Condensation with hydroxylamine and its derivatives with allyl and benzyl groups leads to the oxime and the corresponding substituted products. By reductive amination 3-amino-3-deoxy-alpha-D-allopyranosyl-beta-D-fructofuranoside is obtained which can readily be submitted to further functionalization to methacryloyl and fatty acid derivatives. After silylation of 3-ketosucrose the 3-allyl and butylene-substituted as well as decyl- and dodecyl-substituted sucrose can be obtained via Grignard reaction, the side chains being C-C linked to the saccharide.

Carbohydrate Conformation↗
PubMed1994

Mapping of antigenic epitopes within the recombinant human preproinsulin related to insulin-dependent diabetes mellitus.

The human insulin domains, signal peptide, B-chain, C-peptide, and A-chain, were highly expressed in Escherichia coli as recombinant proteins N-terminally fused to glutathione-S-transferase and a histidine-hexapeptide. The recombinant proteins were purified from insoluble cell fraction by affinity chromatography using metal chelating matrix, which was charged with Ni+2 ions. ELISA screening for autoantibodies directed to preproinsulin were performed with sera from patients with recently diagnosed insulin-dependent diabetes mellitus in order to localize the antigenic epitopes within the human preproinsulin. Of the patients, 14% had developed autoantibodies that recognized either the recombinant C-peptide or the signal peptide. No reaction was observed with the A-chain or B-chain.

Autoantibodies↗
PubMed1994

Characterization of atherosclerosis in a patient with familial high-density lipoprotein deficiency.

We describe the cardiovascular state of a 60-year-old homozygous patient with familial HDL deficiency (Tangier disease). The patient was examined by coronary angiography and intravascular ultrasound because of chest pain at rest and on exertion. We found a normal left ventricular function, moderately diffuse coronary sclerosis without stenosis and no critical stenosis of peripheral arteries. Intravascular ultrasound revealed the three layer appearance of arterial intima, media and adventitia with normal thickness. No calcified plaques or intimal hyperplasia could be detected apart from a single, discrete atherosclerotic lesion in one iliac artery segment. Concentric non-occlusive atherosclerotic lesions which are readily detectable with intravascular ultrasound were not found. The lack of severe atherosclerosis was remarkable insofar as massive foam cell formation and the virtually complete absence of circulating HDL is characteristic of Tangier disease and has been previously demonstrated in this patient. Our findings suggest that HDL deficiency and foam cell formation in Tangier disease are not necessarily associated with accelerated development of atherosclerosis.

Adult↗
PubMed1994

Clinical performance of machined titanium restorations.

In 37 patients 88 titanium restorations were placed during a 1-year period 1990-91. The 69 crowns and 19 fixed partial dentures comprised 147 prosthodontic units. All restorations were fabricated by duplication milling and electrical discharge machining of pure titanium (Procera Technology, Nobelpharma, Gothenburg, Sweden). Based on the results of clinical follow-up, Kaplan-Meier survivor functions were calculated. The survivor rate of 40 metal crowns and pontics was 100%. In 107 porcelain-fused-to-metal units the 3-year survivor rate concerning removal was 95%. When relating the survival to an intact ceramic veneer, the 3-year survivor rate of porcelain-fused-to-metal units was 84%. The quality of the restorations evaluated by the rating system of the California Dental Association was found to be satisfactory in the vast majority of cases. It can be concluded that machined titanium restorations are suitable for clinical use, although not all problems, especially in the field of metal-ceramics have yet been completely solved.

Crowns↗
PubMed1994

Captopril inhibits the agonist-induced increase of cytosolic free Ca2+ in glomerular mesangial cells.

To evaluate the underlying mechanism of the putative renal protective effects of angiotensin converting enzyme (ACE) inhibitors, the modulatory action of captopril on the angiotensin II (Ang II) and platelet-derived growth factor (PDGF)-induced increase of cytosolic free calcium concentration ([Ca2+]i) was investigated in cultured glomerular mesangial cells (MC) from spontaneously hypertensive rats from the Münster strain (SHR) and normotensive Wistar-Kyoto rats (WKY). Resting [Ca2+]i was not affected by captopril in MC from either SHR or WKY. Captopril inhibited the Ang II-induced [Ca2+]i increase in MC from both SHR and WKY in a dose-dependent and time-dependent fashion. The preincubation of MC with 1 mumol/liter captopril for 40 minutes significantly reduced the Ang II-induced [Ca2+]i increase in SHR from 167 +/- 30 nmol/liter (N = 17) to 74 +/- 20 nmol/liter (N = 8, P < 0.05) and in WKY from 102 +/- 42 nmol/liter (N = 14) to 43 +/- 12 nmol/liter (N = 7, P < 0.05). After removal of external calcium there was no significant effect of captopril on the Ang II-induced [Ca2+]i increase. With the Mn2+ quenching technique, it was confirmed that captopril affects Ca2+ influx. Phospholipase C activity as estimated by diacylglycerol formation was not changed by captopril. The preincubation of MC with 1 mumol/liter captopril for 40 minutes significantly reduced the PDGF-induced [Ca2+]i increase in SHR from 166 +/-54 nmol/liter (N = 9) to 31 +/- 19 nmol/liter (N = 6, P < 0.01) and in WKY from 127 +/- 31 nmol/liter (N = 11) to 61 +/- 32 nmol/liter (N = 5, P < 0.05). Similarly captopril reduced the [Ca2+]i increase induced by endothelin and vasopressin. The results indicate that the actions of Ang II and PDGF on MC are modulated by captopril, probably resulting in the impairment of the calcium dependent contractile response of mesangial cells.

Angiotensin II↗
PubMed1994

Anastomotic aneurysms following aortofemoral vascular replacement.

Despite the advances in reconstructive vascular surgery, anastomotic aneurysms,--particularly in inguinal position--have remained an unsolved problem. Between 1985 and 1992 in 46 patients who underwent aortoiliac or aortofemoral bypass grafting 58 anastomotic aneurysms were operated in our institution. The mean interval between primary reconstruction and onset was 65.0 months. In 54% we observed real suture aneurysms. Technical faults are supposed to be the most causative factor in development of anastomotic aneurysm. The rate of recurrence after repair was 10%. There was no postoperative mortality. It is concluded that comprehensive follow-up is required after aortofemoral grafting. Because of the risk of peripheral embolization and local disruption surgical repair has to be done soon after the diagnosis of anastomotic aneurysm.

Adult↗
PubMed1994

Aorto-caval fistula--an uncommon complication of infrarenal aortic aneurysms.

Aorto-caval fistulas are an uncommon complication of infrarenal aortic aneurysms, being found in 0.22% to 6.04% of all cases. Operating on 1231 patients with abdominal aortic aneurysm in the last 30 years we saw 17 patients with an aortocaval fistula. While 5 patients showed an isolated fistula, 12 had an additional rupture of the aneurysm into the retroperitoneal space or the abdominal cavity. Only in four patients was the aorto-caval fistula diagnosed preoperatively. In 16 patients the fistula was closed from within the aorta. One patient needed ligation of the vena cava and the iliac veins. Mortality rate was 40% in the group with isolated fistula and 66.7% in the group with concomitant rupture. Aorto-caval fistula is a severe complication of abdominal aortic aneurysms, which may be fatal and demands early diagnosis and prompt treatment.

Aged↗
PubMed1994

Once- versus twice-daily administration of controlled-release isosorbide-5-mononitrate 60 mg in the treatment of stable angina pectoris. A randomized, double-blind, cross-over study. The Swedish Multicentre Group.

Thirty-seven patients with chronic, stable angina pectoris were included in a randomized, double-blind cross-over study to assess the efficacy of once- and twice-daily dosage regimens of 60 mg isosorbide-5-mononitrate, in a controlled-release formulation (5-ISMN Durules, Astra). After 2 weeks of treatment, during a symptom-limited bicycle ergometer exercise test performed 3 h after the dose, the time to 1 mm ST segment depression was observed to be longer by once-daily than by a twice-daily dosage regimen (614 +/- 165 vs 561 +/- 148 s; P < 0.01). The time to the end of exercise was also significantly prolonged by once-daily dosage, as compared with placebo (693 +/- 158 and 645 +/- 173 s, respectively; P < 0.05), which was not observed with the twice-daily regimen. Both dosage regimens still had a significant effect on the prolongation of the time to onset of angina 9 h after the dose: 420 +/- 164 s by placebo, 492 +/- 161 s by once-daily dosage; P < 0.01, and 466 +/- 154 s by twice-daily dosage; P < 0.05. Anginal attack rate and nitroglycerin consumption was significantly lower during the once-daily dosage period as compared with placebo; this difference was not evident during the twice-daily administration of the drug. Controlled-release 5-ISMN 60 mg given once daily was effective in angina pectoris patients for at least 9 h after the dose and showed no clinical signs of tolerance after 2 weeks of the treatment. Attenuation of the clinical effect was observed with the twice-daily (in 12 h intervals) dosage regimen, presumably caused by constantly high 5-ISMN plasma concentration.

Analysis of Variance↗
PubMed1994

[Bovine heterologous graft in replacement of a small calibre artery].

An experimental study of a new biologic vascular graft for reconstruction of small diameter arteries was carried out in 50 sheep. Results up to 2 years allow us to conclude that the new vascular prostheses may be "reutilized" by the host. Infections and aneurysmal degeneration were be observed. Early occlusion of the graft due to technical reasons occurred in only one case.

Animals↗
PubMed1994

Is the brush border membrane of the intestinal mucosa a generator of "chymosomes"?

1. The microvilli of enterocytes in calf intestine demonstrate high levels of vesiculation activity at the top and at the basal region. 2. The morphology of the vesicles associated with microvilli (100-500 nm diameter, unilamellar, few intramembraneous particles, high AP activity) is very similar to the morphology of vesicles found in the chyme. 3. Vesicles can be purified 6-10 fold from chyme of the calf intestine applying a Mg(++)-precipitation method, used for brush border membrane preparation. 4. Specific activities of alkaline phosphatase and disaccharidases were found to be much higher in chyme vesicles than in the mucosa. 5. Phospholipid content and phospholipid composition is in chyme vesicles different from brush border membrane vesicles. 6. The characterized chyme vesicles are referred to as chymosomes. We consider the mucosa as a large-scale generator of chymosomes, i.e. digestive enzymes bearing vesicles.

Alkaline Phosphatase↗
PubMed1994

[Coronary angiography and intravascular ultrasound examination of a 60-year-old patient with familial HDL deficiency (Tangier disease)].

A 60-year-old homozygous patient with familial high density lipoprotein deficiency (Tangier disease) was examined by coronary angiography and intravascular ultrasound because of typical angina pectoris. We found a normal left ventricular function, moderately diffuse coronary sclerosis without stenosis, and no critical stenosis of peripheral arteries. Intravascular ultrasound revealed normal thickness and the three-layer appearance of the arterial intima, media, and adventitia within the peripheral arteries, and showed a single, discrete arteriosclerotic lesion in one iliac artery segment. The lack of severe atherosclerosis was remarkable insofar as massive foam cell formation in reticuloendothelial tissues and the virtually complete absence of circulating HDL is characteristic of Tangier disease and had been previously demonstrated in this patient.

Arteriosclerosis↗
PubMed1994

[Place of surgical treatment of lung metastases].

From 1.1.1980 to 31.12.1992, ninety-four of our patients underwent surgical removal of pulmonary metastases. The classification of the primary tumours found cas as follows: sarcoma 24.5% (n = 23), renal carcinoma 22.3% (n = 21), malignant melanoma 19.1% (n = 19), colon carcinoma 15.9% (n = 15) and ovarian and testicular tumours with 10.6% (n = 10). Three cases presented metastases from a carcinoma of the floor of the outh. The remaining cases were secondaries from bronchial, oesophageal and larynx carcinoma and from a malignant thymoma. In 71 cases, the tumour was removed using an atypical resection technique, and in 22 cases by carrying out a lobectomy. In one case an "extended lobectomy" was performed. Hospital mortality was 1.1%. Survival rate was 60% at 1 year and 40% at 3 years. 38.3% of the patients lived for five years or more.

Carcinoma↗