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Biomedical subjects

M Walter

Publications and source records attributed to M Walter.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Cervical anastomotic stenosis after gastric tube reconstruction in esophageal carcinoma. Evaluation of a patient sample 1989-1995].

Common late complications after esophagectomy and gastric tube reconstruction for esophageal carcinoma are symptomatic, benign fibrotic stenoses of the cervical anastomosis, which require dilatation. Since the prognosis of esophageal carcinoma still remains poor, bad functional results such as dysphagia affect quality of life. In a retrospective analysis, our patients were evaluated with regard to the underlying effects of cervical anastomotic stenosis after esophagectomy and gastric tube reconstruction. From 1 January 1989 to 31 July 1995, 173 patients with carcinoma of the esophagus were operated in our institution. Transhiatal esophageal dissection was performed in 133 patients; 40 patients underwent transthoracic en bloc resection. The 30-day mortality rate was 7.5% (13 patients). Postoperative fibrotic stenosis of the cervical anastomosis requiring dilatation occurred in 36.4% (63 patients) 6-12 weeks after operation. Fibrotic stenosis of the cervical anastomosis did not develop in 97 patients. There was a significant difference concerning the incidence of anastomotic leaks within both groups: whereas in 23.8% of the 63 patients who developed a fibrotic stricture of the cervical anastomosis an anastomotic leak preceded this event (P < 0.001), no anastomotic leak occurred in the group of 97 patients with normal healing of the cervical anastomosis. In addition, significantly (P < 0.01) more patients (37.5%, n = 23) with preexisting diabetes mellitus could be found among the 63 patients who developed a fibrotic stricture of the cervical anastomosis, in contrast to the 97 patients without anastomotic stenosis.

Adenocarcinoma↗
PubMed1997

[Adrenal gland incidentaloma is not a "time bomb"--arguments for follow-up control].

Adrenal masses are nowadays more and more diagnosed incidentally. In the vast majority of cases these "incidentalomas" are benign adrenocortical adenomas which do not compel operative therapy. In about 12% of patients an endocrine activity is detected. With Increasing tumor size the risk of malignancy increases. This article summarizes recommendations, only to allow patients with endocrine activity or an increased risk of malignancy to be selected for surgery. A small uncertainty will always remain, but may be minimized by an individually tailored follow-up.

Adrenal Gland Neoplasms↗
PubMed1997

[Fatal outcome factors of intestinal infarct of primary vascular origin].

Despite diagnostic and therapeutic advances, mesenteric vascular occlusion with intestinal infarction is often fatal. Parameters determining the high mortality are seldom discussed in the literature. By univariate statistical analysis we correlated the therapeutic outcome of our patients to 20 parameters. Between 1 January 1984 and 30 April 1996 we treated 22 men and 18 women with acute bowel ischemia of vascular origin. All patients underwent laparotomy, 40% (n = 16) due to the diagnosis of mesenteric infarction. In 15% (n = 6) the laparotomy was only exploratory; in 34 cases (85%) bowel resection was carried out. Mortality for all patients was 55% (n = 22). Univariate analysis of the 20 parameters showed that the therapeutic outcome was significantly correlated to a pre-existing diabetes, the course of hospitalization, and the high ASA class. There was no correlation to the length of resected bowel. Most parameters that determine the mortality of bowel infarction are pre-existing and cannot be influenced, but survival can be achieved in some patients if radical and aggressive resection is carried out at the side of almost complete small bowel infarction and followed by an elective second-look operation. Even short-bowel syndrome can be treated. Patients can return to a near normal lifestyle with an acceptable quality of life with the aid of parenteral nutrition at home.

Aged↗
PubMed1996

Defective regulation of phosphatidylcholine-specific phospholipases C and D in a kindred with Tangier disease. Evidence for the involvement of phosphatidylcholine breakdown in HDL-mediated cholesterol efflux mechanisms.

The negative correlation between coronary heart disease and plasma levels of HDL has been attributed to the ability of HDL to take up cellular cholesterol. The HDL3-induced removal of cellular cholesterol was reported to be impaired in fibroblasts from patients with familial HDL deficiency (Tangier disease, TD). In addition, we have recently shown that HDL3 stimulates the hydrolysis of phosphatidylcholine (PC) in cholesterol-loaded fibroblasts. To investigate whether this cell signaling pathway is involved in cholesterol efflux mechanisms, we compared the HDL3-induced PC hydrolysis in normal fibroblasts and in fibroblasts from a TD kindred, in whom the HDL3- and apolipoprotein A-I (apo A-I)-induced mobilization of cellular cholesterol was found to be reduced by 50%. The HDL3-induced formation of phosphatidic acid (PA) via PC-specific phospholipase D (PC-PLD) was markedly reduced by 60-80% in these cells, whereas the formation of diacylglycerol (DG) via PC-specific phospholipase C (PC-PLC) was two- to threefold enhanced. Defective regulation of PC-PLC and PC-PLD was similarly observed in response to apo A-I and endothelin, but not in response to the receptor-independent stimulation of PC hydrolysis by PMA. A Tangier-like PA and DG formation pattern could be induced in normal cells after preincubation with pertussis toxin, suggesting the involvement of a G-protein. The impaired mobilization of radiolabeled cellular cholesterol in TD cells could completely be overcome by increasing the PA levels in the presence of the PA phosphohydrolase inhibitor propranolol. Conversely, the inhibition of PA formation in the presence of 0.3% butanol as well as the inhibition of DG formation in the presence of the PC-PLC inhibitor D 609 reduced the mobilization of cellular cholesterol both in normal and in TD cells. Our data indicate that the coordinate formation of PA and DG via PC-PLD and PC-PLC is essential for efficient cholesterol efflux. The molecular defect in this TD kindred appears to affect an upstream effector of protein kinase C responsible for the G-protein-dependent regulation of PC-specific phospholipases.

Apolipoprotein A-I↗
PubMed1996

Inhibition of human mast cell chymase by secretory leukocyte proteinase inhibitor: enhancement of the interaction by heparin.

The inhibition of human chymase, a chymotrypsin-like proteinase stored in mast cell granules, by secretory leukocyte proteinase inhibitor (SLPI) is investigated in this study. SLPI is a serine proteinase inhibitor present in human mucus secretions and tissues. It binds heparin, a highly sulfated glycosaminoglycan also found in mast cell secretary granules, and the interaction increases its effectiveness as an inhibitor of neutrophil elastase. Analysis of the chymase-SL interaction by equilibrium and kinetic methods indicates that the inhibition of chymase results from the reversible formation of a stable 1:1 enzyme-inhibitor complex. The dissociation equilibrium constant (determined in reactions containing 0.18 M or 1.0M NaCl (pH 8.0, 25 degrees C) was 5 X 10(-8) and 2 x 10(-8) M, respectively. Addition of heparin to the low-salt reaction decreased the Ki approximately 10-fold to a value of 3 x 10(-9) M, making SLPI a more effective inhibitor of human chymase. The decrease was due primarily to an approximately 10-fold increase in the association rate constant (kass) from 2 X 10(4) to 3 X 10(5) M-1 s-1. The magnitudes of the rate and dissociation equilibrium constants indicate that SLPI has the potential to be a good chymase inhibitor in vivo, especially if chymase and heparin are released from mast cell granules simultaneously. The enhanced interaction in the presence of heparin supports the importance of this glycosaminoglycan to the inhibitory function of SLPI.

Animals↗
PubMed1996

[Long-term parenteral nutrition in vascular-induced short bowel syndrome].

Mesenteric vascular occlusion with intestinal infarction is often regarded as a fatal illness. Often the diagnosis of severe ischemia is made during laparotomy. Sometimes resection is not performed because the conditions is thought to be incurable, and in such cases the mortality is 100%. If radical and aggressive resection is carried out even at the site of almost complete small bowel infarction and followed by an elective second-look operation, survival can be achieved in some patients. The motivation to attempt treatment should be further enhanced by the observation that the short-bowel syndrome following resection can be successfully treated, giving an acceptable quality of life for the patients. Between 1 January 1979 and 31 December 1979 we treated 9 male and 6 female patients with short-bowel syndrome after mesenteric occlusive disease; their ages ranged between 4 and 78 years, and the total duration of parenteral nutrition was 30,494 patient-days. With a median of 1503 days, the longest individual periods of parenteral nutrition were 4,919 and 5,015 days. We show the problems of long-term parenteral nutrition, including catheter-associated and nutritional complications, with reference to the individual courses of patients with short-bowel syndrome after mesenteric infarction. Despite some problems, patients of all ages can return to near-normality with an acceptable quality of life with the aid of parenteral nutrition at home.

Adolescent↗
PubMed1996

[Surgical therapy of advanced hemorrhoidal disease--is an ambulatory surgery intervention possible?].

Hemorrhoidal disease is the most common pathophysiologic abnormality in the anus in the western civilized world. Sixty years after publication of the method in The Lancet, hemorrhoidectomy according to Milligan and Morgan and modifications of their methods are still considered the standard procedure in cases of advanced hemorrhoidal disease. During the last 5 years, 107 patients underwent hemorrhoidectomy in the Department of Surgery at the University of Cologne. In most of these patients, the operation followed Milligan and Morgan's method. There were 69 males and 38 females with a mean age of 47.9 years. Mean length of hospital stay was 4.5 days. We saw one case of postoperative bleeding that required operative review. The patients' risk profile (age, concomitant diseases, ASA classification) did not influence the length of the hospital stay. Operative hemorrhoidectomy according to Milligan and Morgan allows a short stay in hospital according to the individual needs of the patient, with a high degree of safety concerning possible postoperative complications.

Adult↗
PubMed1996

True infrapopliteal artery aneurysms: report of two cases and literature review.

Aneurysms of the infrapopliteal arteries are rare and commonly associated with trauma. Most appear as false aneurysms. Because they are quite rare events, we describe for the first time in the English-language literature two cases of a combination of true aneurysms of the popliteal and tibial arteries. Symptoms at initial examination are calf mass and distal ischemia. Clinical features, radiographic findings, surgical management, and a review of the literature on true infrapopliteal aneurysms are discussed.

Adult↗
PubMed1996

Pulmonary embolectomy: review of a 15-year experience and role in the age of thrombolytic therapy.

OBJECTIVE: Surgical intervention for fulminant pulmonary embolism is nowadays most commonly restricted to patients with failure of or contraindication to thrombolytic therapy. Such a second choice indication may alter operative risks or late outcome, and this was investigated in a retrospective study. MATERIAL AND METHODS: Thirty-six patients (17 male, mean age: 50.6 +/- 15.5 years) with fulminant pulmonary embolism of either the pulmonary trunk or one of the pulmonary arteries and at least one contralateral segment underwent pulmonary embolectomy on cardiopulmonary bypass during a 15-year period (1979-89: 31 patients, group I; 1990-94: 5 patients, group II). Group II included only patients who did not meet the criteria for acute thrombolysis. All patients were in strongly compromised circulatory conditions (29/36 high dose catecholamines, 20/36 mechanical ventilation, 14/36 pre-operative cardiopulmonary resuscitation). RESULTS: The perioperative mortality rate was 26% in group I (8/31 patients, 7 with pre-operative cardiac arrest) and 20% in group II (1/5 patients not related to failure of previous thrombolytic therapy). Severe but non-fatal complications occurred in six patients who fully recovered following treatment. Follow-up was completed to 93% (25/27 patients) and comprised a total of 248 patient-years (mean: 119 months). Twenty-three out of 25 patients (92%) were in functional class I or II (NYHA). No recurrent pulmonary embolism or late clinical symptoms related to embolectomy were observed. One patient died 8 years postoperatively (late mortality: 0.4% patient-year). There was no difference between group I and group II regarding perioperative mortality, complications and late results. CONCLUSIONS: Late results after pulmonary embolectomy are excellent in respect to functional class and late mortality. Early mortality is closely associated with preoperative cardiac arrest. Previous thrombolysis does not alter the perioperative risks, occurrence of complications or late outcome after surgical intervention.

Adolescent↗
PubMed1996

Diadenosine polyphosphates induce transplasma membrane calcium influx in cultured glomerular mesangial cells.

The effects of diadenosine tetraphosphate (AP4A) diadenosine pentaphosphate (AP5A) and diadenosine hexaphosphate (AP6A) on the cytosolic-free calcium concentration ([Ca2+]i) were evaluated in cultured rat glomerular mesangial cells (MCs) using the fluorescent dye technique. The addition of 10 mumol L-1 AP4A, AP5A or AP6A significantly increased [Ca2+]i in MCs by 57 +/- 9 nmol L-1 n = 17; P < 0.01), 76 +/- 27 nmol L-1 (n = 9; P < 0.01) or 65 +/- 12 nmol L-1 (n = 18; P < 0.01) respectively. In the absence of extracellular calcium, there was no significant change in [Ca2+]i in MCs after administration of diadenosine polyphosphates, indicating that these agents induce transplasma membrane Ca2+ influx. AP6A significantly enhanced the angiotensin II-induced changes in [Ca2+]i in MCs. The AP5A-induced transplasma membrane Ca2+ influx was inhibited by the P2 purinoceptor blockers suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), but was not affected by the adenosine A1 receptor blocker 8-cyclopentyl-1.3-dipro-pylzanthine (CPDPX). Adenosine triphosphate (ATP) and adenosine 5'-O-(3-thio)triphosphate (ATP-gamma S) increased [Ca2+]i in MCs, whereas alpha, beta-methylene ATP had no effect on [Ca2+]i in MCs. Measurements of diacylglycerol and phosphatidic acid showed that AP5A and AP6A also stimulated phospholipase C, but had no effect on phospholipase D. The inhibition of phosphatidylcholine-specific phospholipase C significantly reduced the AP5A-induced [Ca2+]i increase. In summary, diadenosine polyphosphates induce Ca2+ influx through P2 purinoceptors and may be involved in the local regulation of vascular resistance evoked by the Ca(2+)-dependent contractile response of mesangial cells.

Adenosine Triphosphate↗
PubMed1996

The prevalence of lung cancer in vascular surgery patients.

Inhalative cigarette smoking is a major risk factor for atherosclerotic disease as well as primary carcinoma of the lung. On that account, this study was performed to determine the prevalence of primary lung cancer on admission in patients scheduled for vascular surgery. All patients presenting to our department for an intervention are screened for lung diseases. If this pretherapeutic examination suggests the existence of a lung tumor further diagnostic procedures are performed. Making use of a prospective computer-assisted patient-documentation system, we analysed incidental findings of lung cancer in those patients admitted for elective surgery. Between Jan. 1st 1990 and October 31st 1994, we electively treated 2214 patients with the diagnosis of vascular stenosis (n = 1711/77.3%) or atherosclerotic aneurysms (n = 503/22.7%) in our department. In 16 of these patients (m:f = 13:3; age 50-72 [mean: 61.1] years) a carcinoma of the lung was detected during preoperative diagnostic procedures, a prevalence of 0.72%. All these patients were smokers, with a daily inhalative nicotine consumption averaging 25 cigarettes per day for a mean of 35 years. 8 patients underwent a surgical (n = 6) or other invasive (n = 2) vascular interventions. In 8 patients no vascular intervention was performed because of the revealed lung carcinoma. The prevalence of lung cancer in a population of vascular patients in the present study is in accord with data of older investigations of high-risk groups. Only 2 out of 16 lung cancers were detected at a prognostically favourable stage. Smokers with symptoms of vascular disease should be carefully examined for signs of lung cancer.

Aged↗
PubMed1996

Allergenic epitopes of bovine alpha S1-casein recognized by human IgE and IgG.

B-cell epitopes of bovine alpha S1-casein, one of the major allergens of cow's milk, were identified by a screening method based on synthetic peptides. According to the known amino acid sequence of alpha S1-casein, a set of 188 overlapping sequential decapeptides shifted by one amino acid was manually synthesized on polyethylene pins by the 9-fluorenyl-methoxycarbonyl (Fmoc) method. Peptides were screened by an enzyme-linked immunosorbent assay (ELISA) specific for human IgE and IgG. Bound antibodies were detected by successive incubation with up to three polyclonal antibodies, the last one conjugated to horseradish peroxidase. Tested sera were from 15 patients with acute clinical reactions to cow's milk and IgE-specific reactions to bovine alpha-casein in the ELISA and immunoblot. Sera from 10 healthy subjects without remarkable reactions to cow's milk proteins were used as controls. All sera from allergic subjects showed reactions with three regions of alpha S1-casein, corresponding to amino acids 19-30, 93-98, and 141-150. Furthermore, individual sera showed reactions with other parts of the protein. No essential differences in the epitope specificity of IgE and IgG were found. Inhibition of IgE binding to alpha S1-casein with soluble synthetic peptides confirmed the results and revealed peptide CN-2 as the most inhibiting one.

Adolescent↗
PubMed1996

PCR-in situ hybridization detection of human T-cell lymphotropic virus type 1 (HTLV-1) tax proviral DNA in peripheral blood lymphocytes of patients with HTLV-1-associated neurologic disease.

PCR-in situ hybridization (PCR-ISH) was developed and utilized to determine the distribution of human T-cell lymphotropic virus type 1 (HTLV-1) tax proviral DNA in peripheral blood lymphocytes (PBL) from patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). PCR-ISH of HTLV-1 tax DNA in PBL from patients with HAM/TSP revealed that 1 in 5,000 to 1 in 10,000 PBL contained virus. PCR-ISH was sensitive, because a positive signal was consistently demonstrated from the HTLV-1-infected cell lines HUT-102 (which contains four to six copies of HTLV-1 proviral DNA per cell) and MT-1 (which contains one to three copies of HTLV-1 proviral DNA per cell). Also, intracellular amplification by PCR-ISH significantly increased sensitivity compared with conventional ISH and was shown to be specific for HTLV-1 tax DNA. These results are in contrast to solution-phase PCR amplification in which greater than 1% of cells were estimated to be infected. The discordance between these results is discussed and may indicate that more than one copy of HTLV-1 tax proviral DNA is present in an individual PBL.

Base Sequence↗