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M Maier

Publications and source records attributed to M Maier.

At least 109 records · Page 6Linked to original sources
PubMed1996

Expression of calcium channel subunits in the normal and diseased human myocardium.

We investigated the expression of alpha1 and beta subunits of the L-type Ca2+ channel on the protein level in cardiac preparations from normal human heart ventricles and from the hypertrophied septum of patients with hypertrophic obstructive cardiomyopathy (HOCM). 1,4-Dihydropyridine (DHP) binding and immunorecognition by polyclonal antibodies directed against the C-terminal amino acid sequences of the beta2 and beta3 subunits were used for detection and quantification of alpha1, beta2, and beta3 subunits. Bmax of high-affinity DHP binding was 35 +/- 2 fmol/mg protein in HOCM and 20 +/- 2 fmol/mg protein in normal human hearts (P<0.05). In rabbit hearts the anti-beta2 subunit antibody immunoprecipitated 80% of the total amount of DHP-labeled Ca2+ channels present in the assay. Under identical experimental conditions 25% of labeled Ca2+ channels were recovered in the immunoprecipitates of both normal and HOCM ventricles. A similar partial immunoprecipitation was observed in pig hearts. Immunoblot analysis demonstrated that the beta2 subunit was associated with the DHP receptor/Ca2+ channel in cardiac muscle of rabbit, pig, and human heart. In neither of these purified cardiac Ca2+ channels was the beta3 subunit isoform detected. Our results suggest that both alpha1 and beta2 subunit expression is upregulated in HOCM in a coordinate manner.

Amino Acid Sequence↗
PubMed1996

Management of retained bile duct stones: a prospective open trial comparing extracorporeal and intracorporeal lithotripsy.

BACKGROUND: Endoscopic management of common bile duct stones has become the approach of choice, especially in patients with high surgical risk. Problems are encountered if there are large stones or a duct stenosis. For these difficult stones, shock wave technology serves as an alternative to surgical intervention. METHODS: A total of 125 patients with common bile duct stones in whom conventional endoscopic treatment had failed were selected and treated either by extracorporeal piezoelectric lithotripsy (ESWL, n = 79) or intracorporeal electrohydraulic lithotripsy (EHL, n = 46). The average age of our patients was 70 years. RESULTS: In the ESWL group visualization of the stones by ultrasound and ensuing treatment were possible in 71 out of 79 patients (90%); stones could be fragmented in 68 patients. The biliary tree could then be completely freed of calculi in 62 of 79 patients, a success rate of 78.5%. In the EHL group, stones were successfully fragmented in 38 of 46 patients; 34 patients (74%) eventually became stone free. Thirty-day mortality was zero in both groups. Combined treatment including ESWL, EHL, and intracorporeal laser lithotripsy was finally successful in 118 patients (94%). CONCLUSIONS: Endoscopic management in combination with the lithotripsy techniques described can be recommended as the method of choice for treating difficult common bile duct stones. A success rate of almost 100% and a mortality rate of 0% is now the established standard, even in elderly and unstable patients.

Aged↗
PubMed1996

Influence of pentoxifylline and albifylline on liver microcirculation and leukocyte adhesion after hemorrhagic shock in the rat.

The aim of this study was to evaluate the effects of two xanthine derivates, pentoxifylline (PTX) and its more metabolically stable analogue, albifylline (HWA 138), on hepatic sinusoidal perfusion and leukocyte endothelial interactions in the liver after hemorrhagic shock. Sprague-Dawley rats (n = 8 per group) were exposed to hemorrhagic shock at 40 mm Hg for 60 minutes and subsequently resuscitated with 60% of shed blood and lactated Ringer's solution before intravital microscopy of the liver 3 hours after resuscitation. Using fluorescence markers, quantitative evaluations of red blood cell (RBC) and white blood cell (WBC) velocities and WBC endothelium interactions were performed. Animals were chosen randomly and blindly to receive either PTX or HWA 138 in a dosage of 25 mg/kg body weight 1 minute before resuscitation, or they received placebo. This was followed by a further infusion of 25 mg/kg body weight during the 3-hour resuscitation period. Although systemic parameters were comparable in all groups, both xanthine derivates enhanced the reduced velocity of RBCs and WBCs of the placebo group. Pathological values of WBC endothelium adhesion in the placebo group (adhesion index: 126.7 +/- 19.5 s/100 WBCs, mean +/- SE) was significantly reduced by PTX (64.4 +/- 10.5, p < 0.05) and HWA 138 (71.9 +/- 10.7, p < 0.05). The results indicate a significant reduction of shock-induced leukocyte adhesions to the sinusoidal endothelium in the liver. In addition, both xanthine derivates led to improved microvascular blood flow in the liver. Thus, PTX and HWA 138 reveal multiple positive effects on early shock-induced alterations in the liver, supporting earlier studies which indicated their potential application in shock therapy.

Animals↗
PubMed1996

Idiopathic mesenteric varices causing lower gastrointestinal bleeding.

We report a case of lower gastrointestinal bleeding caused by idiopathic mesenteric varices. A 25-year-old man presented with a history of two episodes of lower gastrointestinal bleeding without transfusion. Colonoscopy revealed varices of the entire colon and terminal ileum. Intravariceal blood flow was demonstrated by dopplersonography. Vascular abnormalities were excluded by selective angiography of the upper and lower mesenteric artery. No therapy was given without a new episode of bleeding and there has been no further bleeding to date (a period of 14 months). Mesenteric varices are a rare cause of lower gastrointestinal bleeding, almost always associated with portal hypertension. The varices are idiopathic in only a few cases. The therapy depends on the intensity of bleeding, but resection is the most frequent treatment.

Adult↗
PubMed1996

Peroral laser lithotripsy of difficult intrahepatic and extrahepatic bile duct stones: laser effectiveness using an automatic stone-tissue discrimination system.

OBJECTIVES: The use of laser lithotripsy with an integrated stone-tissue discrimination system is an ambitious treatment modality for bile duct stone fragmentation. The aim of our prospective study was to determine the effectiveness and safety of the laser system and to find whether it reduced the need for choledochoscopy. METHODS: Thirty patients with complicated bile duct stones were treated perorally with a flashlamp-pulsed Rhodamine-6G dye laser and an automatic stone-tissue discrimination system. Initial treatment sessions were performed under fluoroscopic guidance in each patient and switched to choledochoscopic control if the stone could not be approached properly. RESULTS: Eighteen of 19 patients with extrahepatic bile stones were treated under fluoroscopic control; 17 of 19 patients were successfully treated through laser therapy. In nine of the patients with intrahepatic stones (n = 11), choledochoscopy was necessary for sufficient laser lithotripsy; seven of those patients became stone-free. Twenty-four of 30 patients (80%) were stone-free after sole laser therapy. Combined with other methods, the overall success rate was 27/30 (90%). Therapy-related mortality was 0%. CONCLUSIONS: Laser lithotripsy is effective and safe. The stone-tissue discrimination system facilitates therapy under fluoroscopic control and precludes the need for choledochoscopy, which is highly significant (p <0.001) if the calculi are extrahepatically located.

Adult↗
PubMed1996

-Bile duct stenoses and leakage after cholecystectomy: endoscopic diagnosis, therapy and treatment outcome-.

Minimal invasive methods compete with surgical treatment in the therapy of complications after cholecystectomy. In this retrospective study we evaluate the efficacy of endoscopically placed biliary stents in 35 patients (25 female, ten male) with biliary strictures and/or leakage after cholecystectomy. 27 patients received a 10- or 11.5-French endoprosthesis, eight patients needed a percutaneous-transhepatic-cholangio-drainage (PTCD). Four patients (11.4%) underwent a surgical therapy. Endoscopic therapy was successfully completed in 23 patients (65.7%), at which we noticed a superior result in patients with early incidenced stenosis/leakages after cholecstectomy. During a follow-up period of 1-109 months (median 28 months) two recurrent strictures (5.7%) were observed. As a complication we have seen a prosthesis-dislocation after PTCD. None of the patients died of complications related to endoscopic therapy.

Adult↗
PubMed1996

Endoscopic biliary stenting for the palliation of pancreatic cancer: results, survival predictive factors, and comparison of 10-French with 11.5-French gauge stents.

OBJECTIVES: To compare the efficacy and complications of different stent lengths and diameters in the palliation of jaundice caused by pancreatic cancer, as well as investigate survival predictive factors and the success of endoscopic therapy. METHODS: This study summarizes our results with 103 pancreas cancer patients treated by endoscopic plastic biliary stenting, of whom 87 were followed up until death or the time of writing. Before therapy, bilirubinemia, tumor primary size, presence of distant metastases, and signs of duodenal involvement were evaluated as prognosis risk factors. In a retrospective, nonrandomized fashion, we compared the efficacy and complications (especially clogging) of 10-French versus 11.5-French gauge stents and of "short" (< or = 8 cm) versus "long" (> or = 9 cm) prostheses. RESULTS: Thirty six men and 51 women (median age 74 yr) with pancreatic cancer were analyzed. Stenting could abolish jaundice or make it imperceptible (bilirubinemia < 3 mg %) in 74 patients (85%). Median bilirubinemia after treatment decreased from 13.9 mg/dl to 1.0 mg/dl. Hospital mortality was 2.7%. The commonest long term complication was clogging, which occurred 66 times in 33 patients. Median stent patency was 3 and 4 months for 10-F gauge and 11.5-F gauge stents, respectively (p > 0.05). When analyzing the patients who were alive 6 months after therapy, the clogging rate was 46% and 55% for 10-F and 11.5-F stents, respectively (p > 0.05). The length also did not influence stent patency. The only risk factor assessed before therapy, which independently predicted survival, was the presence of distant metastases. Median survival for patients with metastatic disease was 2.5 months and 9 months for those without metastases (p = 0.0015). CONCLUSIONS: We conclude that 10-F and 11.5-F stents have the same efficacy in the palliative management of malignant obstructive jaundice due to cancer of the pancreas. Detection of distant metastases is the best outcome predictive factor in these patients and should be regarded as a restriction to the insertion of biliary metal stents.

Adenocarcinoma↗
PubMed1996

[Aortoduodenal fistula as the cause of gastrointestinal hemorrhage].

The aortoenteric fistula is one of the rare causes of gastrointestinal bleeding. A 73 year old patient presented with a secondary fistula after implantation of a synthetic graft. The diagnosis was confirmed by endoscopy. At elective laparotomy, a communication between the graft and the duodenum was discovered. Principally the combination of gastrointestinal bleeding and aortic graft is always suspicious of an aortoenteric fistula. The treatment must be surgical.

Aged↗
PubMed1995

High precision measurement of electrical resistance across endothelial cell monolayers.

Effects of vasoactive agonists on endothelial permeability was assessed by measurement of transendothelial electrical resistance (TEER) of human umbilical vein endothelial cells (HUVECs) grown on porous polycarbonate supports. Because of the low values of TEER obtained in this preparation (< 5 omega cm2) a design of an Ussing type recording chamber was chosen that provided for a homogeneous electric field across the monolayer and for proper correction of series resistances. Precision current pulses and appropriate rates of sampling and averaging of the voltage signal allowed for measurement of < 0.1 omega resistance changes of the endothelium on top of a 21 omega series resistance of the support and bathing fluid layers. Histamine (10 microM) and thrombin (10 U/ml) induced an abrupt and substantial decrease of TEER, bradykinin (1 microM) was less effective, PAF (380 nM) and LTC4 (1 microM) had no effect. TEER was also reduced by the calcium ionophore A-23187 (10 microM). The technique allows for measurements of TEER in low resistance monolayer cultures with high precision and time resolution. The results obtained extend previous observations in providing quantitative data on the increase of permeability of HUVECs in response to vasoactive agonists.

Bradykinin↗
PubMed1995

Proton magnetic resonance spectroscopy: an in vivo method of estimating hippocampal neuronal depletion in schizophrenia.

Diffuse loss of cortical volume and ventricular enlargement have been demonstrated in schizophrenia using imaging. In addition, histological studies have provided evidence that the number of neurons in the medial temporal lobe structures is reduced and that the cytoarchitecture is abnormal. In an attempt to correlate these histological findings with in vivo estimates of neuronal integrity we have studied the concentration of the neuronal marker N-acetyl aspartate (NAA) in the hippocampi of schizophrenics using in vivo Magnetic Resonance Spectroscopy (MRS). Compared with a group of healthy volunteers schizophrenics showed a 22% loss of NAA in the left hippocampus. Two other metabolites, choline and creatine showed bilateral reduction in schizophrenics and these achieved significance in the left hippocampus. These results indicate a significant depletion of NAA in schizophrenia and are in close agreement with the reported neuronal loss in the hippocampus detected histologically. We propose that in vivo MRS is a valid measure of integrity of neuronal populations in schizophrenia.

Adult↗
PubMed1995

Tropheryma whippelii endocarditis confirmed by polymerase chain reaction.

This report concerns a patient with cardiac manifestation of Whipple's disease. For the first time, the gene that encodes the 16s rRNA of Tropheryma whippelii was identified in a native aortic valve by means of a polymerase chain reaction technique. DNA amplification gives evidence of Tropheryma whippelii as a causative organism in infective endocarditis.

Actinobacteria↗
PubMed1995

In vivo magnetic resonance spectroscopy. Applications in psychiatry.

BACKGROUND: Nuclear magnetic resonance is a non-destructive and non-invasive technology that is highly suited for research in psychiatry. It is establishing itself as a versatile means of studying brain morphology, chemistry and function and is finding a place in the diagnosis of disease, monitoring of treatment and the study of basic brain processes. METHOD: A literature review was undertaken. RESULTS: Magnetic resonance spectroscopy has been shown to distinguish between psychiatric disorders, and has provided evidence of their pathophysiological mechanisms. CONCLUSIONS: Spectroscopy in particular opens a window, for the first time, on the study of in vivo brain chemistry.

Brain↗
PubMed1995

[Percutaneous transhepatic cholangioscopy (PTCS)--an important supplement in diagnosis and therapy of biliary tract diseases (indications, technique and results)].

In 39 patients with biliary disease inappropriate for a transpapillary access (21 m, 18 f, mean age 62 y.) 61 percutaneous transhepatic cholangioscopies (PTCS) were performed. In 28 cases (71.8%) diagnostic PTCS was done in order to investigate the etiology of a biliary stenosis. Nine of these patients had histological as well as clinical outcome indicating a benign lesion. Histology was positive for malignancy in 14 (82%) out of 17 patients with clinically assumed malignant stenosis. The etiology of the stenosis remained obscure from a clinical point of view in two cases with negative histology for malignancy. In twelve patients (30.7%) we performed PTCS for endoscopically controlled laser or electrohydraulic lithotripsy of bile duct stones. The procedure was successful in all patients and stone fragments were delivered to the duodenum by saline lavage. Seven of these patients had stones combined with a benign stenosis and were additionally treated by long-term drainage (Yamakawa drain) for three to twelve months. Two of the seven patients had no relaps of the biliary stricture after a follow-up of ten and twelve months respectively. In five cases (12.8%) PTCS controlled insertion of a guide-wire was attempted after failure of the radiologically guided internalization of the percutaneous drainage. The procedure was successful in three of these patients.

Adult↗
PubMed1995

[Anastomotic recurrence with tumor stenosis after Billroth II gastrectomy for adenocarcinoma: implantation of 2 metal stents as palliative therapy].

We report on a 70 year old patient with a great relapse in the region of the anastomosis after a palliative, subtotal gastrectomy with Billroth-II-gastrojejunostomie because of an adenocarcinoma one year before. He was unable to swallow fluids or solid food. The possibility of a sufficient gastroenteroanastomosis was certainly limited (great tumor-mass left during operation). So we implantated two metal stents in the afferent and the efferent limb, respectively. The patient's vomiting completely relieved and he was able to swallow fluid food again. After that treatment the patient's quality of live noticeably increased. Furthermore, by stenting the afferent limb a sufficient drainage out of the duodenum could be reached, thereby preventing an increasing cholestasis.

Adenocarcinoma, Mucinous↗
PubMed1995

[Bleeding peptic ulcers--concept for acute therapy].

Acute ulcer bleeding still is a life-threatening event. The therapeutic goal is to establish intensity, activity and location of the bleeding and to assess primary hemostasis by consequent endoscopic therapy, also preventing recurrence significantly. With the injection method, primary hemostasis accounts for over 90% success. Also recurrent bleeding can be stopped to the same extent. Endoscopic doppler allows a qualitative and quantitative registration of potentially dangerous vessels on the ulcer base. Drug therapy does serve for the acute treatment to a lesser extent; it is more valid for the initiation of the conservative ulcer therapy. Surgical interventions therefore confined to risk patients in whom a primary hemostasis failed or the ulcer is located in a dangerous site, for instance in the back wall of the duodenal bulb.

Acute Disease↗
PubMed1995

[Risks and follow-up after crural vascular reconstruction in the extremity at risk for ischemia].

After 36 crural bypass operations the operative risk and the long-term results were analyzed in 34 patients. For reconstruction autologous vein (n = 12), a composite graft (saphenous vein and PTFE, n = 10) and in 14 cases a 6 mm PTFE graft were used. In 18 cases a monobypass, in another 16 patients a jump graft and in two patients a sequential bypass were performed. Postoperative complications were seen in 16.7%. An early bypass occlusion was seen in one patient, an amputation was necessary in 2 patients. After 1,2 and 3 years the bypass patency rate was 85%, 67% and 67%. The long-term results were dependent on the bypass material. The best results were seen with vein or composite grafts with a 3 year patency rate of 82% in contrast to only 39% of a PTFE graft.

Aged↗