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H Neuhaus

Publications and source records attributed to H Neuhaus.

At least 73 records · Page 4Linked to original sources
PubMed1994

Etl2, a novel putative type-I cytokine receptor expressed during mouse embryogenesis at high levels in skin and cells with skeletogenic potential.

The regulatory effects of signaling proteins like hormones, growth factors, and cytokines are mediated by specific cell surface receptors which are grouped into distinct families on the basis of structural criteria. Here we report on the isolation and embryonic expression of a novel mouse gene, Etl2 (enhancer trap locus 2) which, based on its deduced amino acid sequence, constitutes a new member of the cytokine type-I receptor family. Among type-I receptors Etl2 is most similar to the alpha subunits of the human ciliary neurotrophic factor (CNTF) receptor and the mouse interleukin-6 (IL6) receptor with 32 and 30% identical amino acids, respectively. From Day 9 p.c. (postcoitum) onward low levels of Etl2 mRNA were detected in mesenchymal cells throughout the embryo and in parts of the nervous system, in particular in the ependymal linings of the spinal cord and the developing brain vesicles and in the neuronal layer of the retina. Highest levels of Etl2 expression were found on Day 12.5 p.c. in the craniofacial mesenchyme and during subsequent development in mesenchymal cells around all developing cartilages. At later stages, Etl2 transcripts were abundant in the dental papilla, the dermis, and hair follicles, as well as in the perichondrium and periost, i.e., in regions containing chondro and osteo progenitor cells. Etl2 mRNA was not detected, however, in mature odontoblasts, chondroblasts, osteoblasts, chondrocytes, and osteocytes. Our results suggest that Etl2 is a new orphan receptor belonging to the type-I cytokine receptor family and that Etl2 might have regulatory functions, particularly in the control of proliferation and/or differentiation of skeletogenic progenitor and other mesenchymal cells.

Amino Acid Sequence↗
PubMed1994

Cholangioscopy.

Explore the source record for details and available documents.

Biliary Tract↗
PubMed1994

[Endoscopy of small ducts: a luxury for a few?].

A plethora of tiny endoscopes has become available for endoscopy of the biliary tree and the main pancreatic duct. Main indications are differentiation of radiologically undetermined ductal lesions and guided lithotripsy of difficult bile duct stones. The technique of peroral and percutaneous transhepatic miniendoscopy is safe after endoscopic papillotomy or percutaneous biliary drainage. Changes of the ducts can be reliably visualized but target biopsies are required for histological confirmation of the macroscopic diagnosis. However, the technique is particularly difficult for the peroral approach, and a comparison with radiological biopsy procedures is warranted. Lithotripsy of biliary and pancreatic stones under direct visual control offers a time-saving alternative to ESWL but requires a skillful endoscopy team. In case of a failure of peroral stone removal due to a difficult anatomy, percutaneous transhepatic cholangioscopy should be considered as an effective alternative to surgery.

Cholestasis↗
PubMed1994

[Possibilities of endoscopy in bile duct lesions].

Biliary duct injuries are occasional complications of cholecystectomy, encountered especially during early experience of laparoscopic cholecystectomy. Beside surgical reintervention, several promising endoscopic therapeutic procedures are available. Endoscopic papillotomy, possibly in combination with the placement of a drain, brings about occlusion of biliary leakage and fistula in 80% of cases. Strictures and stenoses of biliodigestive anastomoses can be treated using endoscopic transpapillary or, additionally, transhepatic percutaneous techniques. The results are comparable to those of surgery with lower rates of complications. For final judgement, however, a longer period of observation is necessary. At the moment non-surgical procedures are to be considered for patients at high risk from surgery and patients with recurrent stenoses after surgical interventions. Management of choledocholithiasis, complicating cholecystolithiasis, is becoming more and more a task for the endoscopist, at least at the present stage of evolution of laparoscopic cholecystectomy. Endoscopic bile duct clearance with or without percutaneous clearance, if necessary in combination with modern techniques of lithotripsy, is successful in almost all cases. However, the indications for risky and time-consuming procedures should always be discussed between surgeons and internists.

Biliary Fistula↗
PubMed1993

[The benefits and risks of percutaneous transhepatic cholangioscopy].

Percutaneous transhepatic cholangioscopy (PTCS) was undertaken in 101 patients (for diagnostic reasons in 64 and/or therapeutic reasons in 56) out of 167 consecutive patients (56 women, 45 men; mean age 64.2 [27-95] years) in whom percutaneous transhepatic drainage had been instituted. In all but one of 64 patients PTCS clearly defined stenoses which had been unclear in the cholangiogram. There was a 90% accuracy of histological diagnosis of biopsies obtained under vision in 60 cases. A malignant stenosis was seen in 19 of 25 cases (sensitivity 76%). Severe stenosis, not passable by contrast medium, were recanalized cholangioscopically in 14 of 15 cases. Biliary tract stones were completely removed by PTCS in 40 of 41 patients, by mechanical means (n = 4) or intracorporeal lithotripsy (n = 37). There were no complications from PTCS. It is concluded that PTCS can be performed safely and reliably in patients with functioning percutaneous transhepatic drainage. It provides the diagnosis of previously unclear cholangiographic findings as well as treatment of difficult biliary tract stenoses and/or ductal stones.

Adult↗
PubMed1993

Laser lithotripsy of difficult bile duct stones under direct visual control.

Biliary laser lithotripsy was performed under direct visual control in 35 consecutive patients not amenable to routine endoscopy. The patients had 1-50 (median 1) bile duct stones with the greatest diameter of the largest stone being 9-42 mm (median 20 mm). Conventional endoscopic treatment had failed because of an inaccessible papilla (16 patients), biliary strictures (seven patients), and impaction or large size of calculi (12 patients). Twelve patients, depending on their anatomical condition, underwent peroral cholangioscopy by means of a mother-babyscope system. Percutaneous cholangioscopy was initially carried out in 23 patients, 7-20 days (median 10 days) after creation of a transhepatic fistula. Pulsed dye laser (32 patients) or alexandrite laser (three patients) lithotripsy was applied under an appropriate direct visual control in all cases. Complete stone disintegration succeeded in 33 of 35 patients. All resultant fragments passed the papilla within a mean number of 1.3 treatment sessions. Peroral cholangioscopic lithotripsy failed in two cases. One patient successfully underwent percutaneous laser treatment and the other patient was referred to surgery. Fever, temporary haemobilia, or a subcapsular liver haematoma were seen in a total of eight patients during establishment of the cutaneobiliary fistula. A 95 year old patient who had been admitted with septic cholangitis died because of cardiorespiratory failure 5 days after bile duct clearance. It is concluded that laser lithotripsy performed under a direct visual control is an effective and safe procedure for the non-surgical treatment of difficult bile duct stones. Ductal clearance can usually be achieved in a single treatment session when the papilla and the stones are accessible by the peroral route. Percutaneous cholangioscopic lithotripsy is more time consuming but highly effective even in patients with a difficult anatomy, bile duct strictures, or intrahepatic calculi. This approach should be limited, however, to cases not amenable to retrograde procedures because the creation of the cutaneobiliary fistula is not without risks.

Aged↗
PubMed1993

[Hilar bile duct cancer: diagnostic and therapeutic strategies].

Hilar bile duct carcinoma is difficult to diagnose and requires high standards of a curative or palliative therapy. The tumor staging is performed by means of transabdominal sonography, CT scan, endoscopic retrograde cholangiography, and/or percutaneous transhepatic cholangiography and angiography. The value of cholangioscopy and endosonography must be evaluated in further studies. These procedures could improve the preoperative selection of completely resectable tumors. In addition, the mapping of tumor extension into individual hepatic segments facilitates curative operations with the smallest necessary hepatic resection which is associated with low early mortality rates and good long-term results. Nevertheless, the majority of patients can only be treated by palliation with operative, percutaneous, or endoscopic drainage. The decision of the selection of the method is individual, since there are no controlled trials for the hilar bile duct carcinoma.

Adenocarcinoma↗
PubMed1993

[Peroral and percutaneous transhepatic cholangioscopy].

Cholangioscopy, in conjunction with histological examinations, yields diagnostic information in unclear biliary diseases in addition to conventional indirect imaging methods. Unclear stenoses and protruded lesions can be differentiated, and the preoperative staging can probably be improved due to an exact mapping of the intraductal extension of bile duct lesions. Cholangioscopic electrohydraulic lithotripsy or laser treatment of stones not amenable to routine endoscopy are highly effective and safe alternatives to surgery. The peroral technique promises a rapid visualization of the biliary tree, provided that the papilla can be approached adequately. The retrograde access to lesions above the bifurcation or upstream from strictures is limited. In contrast, the more time-consuming percutaneous transhepatic cholangioscopy can be performed even in patients with a difficult anatomy, retrogradely inaccessible bile duct stenoses or intrahepatic calculi. However, this approach should be limited to cases not amenable to peroral techniques, because the creation of the cutaneo-biliary fistula is not without risks.

Bile Duct Diseases↗
PubMed1993

[The role of endoscopic retrograde cholangiopancreatography in complications after laparoscopic cholecystectomy].

Endoscopic retrograde cholangiography (ERC) following conventional as well as laparoscopic cholecystectomy is a suitable method in the case of residual calculi and biliary leakage. This is due to the fact that this method enables an exact diagnosis and, in most patients, a prompt and effective therapy. Problems due to bile duct injuries frequently arise with a time-lag after surgery. Even in these cases ERC and, in certain anatomical conditions, percutaneous transhepatic cholangiography (PTC) enable the accurate delineation of changes which are the basis of further therapy. Concerning stenoses of the biliary tract the question awaits evaluation as to what extent an endoscopic or radiologic intervention will be a sound alternative to surgery. First results are encouraging.

Biliary Fistula↗
PubMed1992

[Laparoscopic cholecystectomy: ERCP as standard preoperative diagnostic technique].

In a prospective study 250 patients with proven cholelithiasis and clinical, biochemical and ultrasound indications for laparoscopic cholecystectomy (LC) underwent endoscopic retrograde cholangiography (ERCP) and (if bile-duct stones had been shown) endoscopic papillotomy (EPT). The biliary system was demonstrated in 229 patients (91.6%). Biliary tract stones were confirmed in 18 of 68 patients in whom they had been suspected clinically. In addition, ERCP revealed small stones in the bile-duct in eight of 154 patients with normal biochemical results and unremarkable ultrasound imaging, and in seven patients bile-duct anomalies which required EPT or open cholecystectomy. However, in retrospect five of the patients with cystic duct anomalies could have been treated by LC. The complication rate of ERCP/EPT was 3.2%. It is concluded from these results that, in view of the cost and potential risk to the patient, ERCP before LC can be limited to patients suspected of having bile-duct stones, even though small stones may be missed.

Adolescent↗
PubMed1992

The two main rDNA size classes of Ascaris lumbricoides: comparison of transcription termination and spacer organization.

Structural and functional analyses were carried out to compare transcription termination and intergenic spacer organization between the two heterogeneous ribosomal DNA size classes of Ascaris lumbricoides. By performing mung bean nuclease mapping in vivo, we localized the 3' end of the mature 26S rRNA to the same position in both forms. This site coincides with the in vivo and in vitro transcription termination site of the 40S-precursor rRNA from both rDNA size classes. We demonstrate that the 3' boundary of sequences necessary for faithful transcription termination extends 35 bp beyond the end of the 26S rRNA gene and that these sequences are perfectly conserved within the two size classes. The intergenic spacers of both rDNA size classes have been completely sequenced; they are 2410 bp and 1937 bp long and show a sequence homology of 92.8%. There is no evidence for the presence of reiterated termination sites or promoters within the relatively short intergenic spacers of the two rRNA gene classes.

Animals↗
PubMed1992

Pain in extracorporeal shock-wave lithotripsy: a comparison of different lithotripters in volunteers.

The aim of the present study was to investigate pain sensations experienced during extracorporeal shock-wave application, comparing an electrohydraulic (MPL 9000; Dornier Medizintechnik, Germering, Germany), an electromagnetic (Lithostar Plus; Siemens, Erlangen, Germany), and a piezoelectric (Piezolith 2300; Wolf, Knittlingen, Germany) shock-wave system. In nine healty volunteers, three therapeutically used intensities were applied in a randomized order with each lithotripter (MPL 9000: 16, 20, and 24 kV; Lithostar Plus: settings 5, 7, and 9; and Piezolith 2300: settings 2, 3, and 4). The subjects received nine series of 20 shock waves amounting to a total of 180 shock waves per session. The treatment was performed under clinical conditions, and no premedication was given. A visual analog scale and the McGill Pain Questionnaire were used for assessment of pain. In addition, somatosensory evoked potentials caused by shock-wave stimulation were recorded. Some of the volunteers were unable to bear the pain caused by the highest shock-wave intensity of the electrohydraulic (n = 3) and the electromagnetic system (n = 4). Estimates using the visual analogue scale showed increased pain sensations with increasing energy settings for each lithotripter. The amplitudes of the somatosensory evoked potentials became larger, and latencies shortened with increasing stimulus intensities (P less than 0.05). Subjective estimates by means of the visual analogue scale (P less than 0.01) as well as the McGill Pain Questionnaire (NS) and the somatosensory evoked potentials (P less than 0.05) showed that stimulation by the piezoelectric lithotripter was less painful than stimulation by the two other generators.

Adult↗
PubMed1992

Aerobilia and hypomotility of the sphincter of Oddi in a patient with chronic intestinal pseudo-obstruction.

A 50-year-old woman with a typical history of chronic idiopathic intestinal pseudo-obstruction was admitted to hospital because of an acute episode of abdominal cramps, nausea, and vomiting. The diagnosis of chronic idiopathic intestinal pseudo-obstruction had been established in this patient who had malnutrition and extreme weight loss as a result of severe malabsorption syndrome. The abdominal roentgenogram showed a typical hypotonic intestine with an enlarged stomach and distended intestinal loops with the radiological signs of an ileus. In addition to former episodes, there was also a transient aerobilia. The patient had not undergone biliary surgery or endoscopic sphincterotomy. To investigate the cause of the findings, endoscopic retrograde cholangiopancreatography and endoscopic manometry of the sphincter of Oddi were performed. The endoscopy showed the stomach and duodenum with a wide and dilated lumen and no spontaneous motility. Endoscopic manometry of the biliary tract and the sphincter of Oddi showed several abnormalities compared with a group of normal volunteers or patients who were examined via biliary manometry for other reasons. There was a low basal pressure (3.5 mm Hg) in the sphincter of Oddi together with low-amplitude phasic contractions (25-30 mm Hg), but the contraction frequency was in the normal range. Further investigations of the motility of the gastrointestinal tract in this patient showed diffuse esophageal spasms and a markedly delayed gastric emptying. The findings of biliary manometry in this patient suggest involvement of the sphincter of Oddi and the biliary system in chronic idiopathic pseudo-obstruction.

Air↗
PubMed1992

Enhancer trap integrations in mouse embryonic stem cells give rise to staining patterns in chimaeric embryos with a high frequency and detect endogenous genes.

We have generated mouse embryonic stem cell lines that carry lacZ enhancer trap constructs integrated in their genome. Fifty-nine cell lines were analysed for lacZ expression in undifferentiated stem cells and at day 7.5, 8.5 and 12.5 of development in chimaeric embryos obtained after blastocyst injection. In 13 cell lines the lacZ reporter gene was expressed in undifferentiated stem cells ('blue', lines) as monitored by beta-galactosidase activity; 46 cell lines did not show detectable beta-galactosidase activity ('white', lines). In chimaeric embryos one-third of the analysed 59 embryonic stem cell lines gave rise to a variety of patterns. Six out of the 13 'blue' lines and 14 out of the 46 'white' lines showed spatially and temporally regulated patterns of beta-galactosidase expression and were additionally analysed on day 9.5. The majority of patterns showed staining exclusively or predominantly in structures of the developing nervous system, three patterns were observed only or predominantly in non-neuronal structures and five patterns were found exclusively in extraembryonic tissues. The analysis of DNA from cell lines that gave rise to staining patterns in chimaeric embryos showed that in 11 out of 15 cases simple integrations had occurred at a single site while in the remaining four cell lines multiple copies had integrated either at a single or at multiple sites. Flanking sequences from five reporter gene integrations have been cloned. At present, three integration sites have been analysed further and in all three cases we have identified transcribed sequences in the flanking DNA and isolated corresponding cDNA clones. The expression patterns of two of these genes were analysed by RNA in situ hybridisation. In both cases, expression of the endogenous genes was more widespread than the corresponding beta-galactosidase staining, suggesting that the reporter gene responded to only a subset of the regulatory elements of the endogenous gene. Our results demonstrate that enhancer trap integrations in embryonic stem cells can be used to efficiently identify transcriptional activation patterns during mouse embryogenesis and to isolate endogenous genes expressed in spatially and temporally regulated patterns.

Animals↗
PubMed1992

Laser lithotripsy of pancreatic and biliary stones via 3.4 mm and 3.7 mm miniscopes: first clinical results.

The pulsed dye laser is safe and effective in lithotripsy of biliary and pancreatic ductal stones, however delivery of the laser energy to the site of the calculi is technically difficult. A 3.4 mm miniscope inserted through a standard duodenoscope was used for transpapillary laser application under direct vision in one patient with an impacted pancreatic stone and in three patients with bile duct stones not amenable to treatment by routine endoscopy. Lithotripsy and ductal clearance was achieved in 3 of the 4 patients within a single treatment session. Percutaneous transhepatic laser lithotripsy via a 3.7 mm miniscope succeeded in the patient in whom the peroral approach had failed and in two further patients with bile duct stones not accessible by a retrograde approach. There were no major complications. The miniscopes provide an appropriate direct visual control for laser lithotripsy of pancreatobiliary calculi. This approach using miniscopes seems to be an effective, minimally invasive and time-saving alternative to conventional endoscopic laser lithotripsy.

Adult↗
PubMed1992

Implantation of self-expanding esophageal metal stents for palliation of malignant dysphagia.

Eleven self-expanding metal stents were perorally implanted in ten patients with locally advanced malignant obstruction of the esophagus. After bougienage of the strictures, the stents were painlessly inserted and properly released by means of an 18 French gauge delivery catheter. In all cases, the endoprostheses expanded to a diameter of 14-20 mm and achieved immediate improvement of dysphagia. One perforation was seen after a single session of dilatation and subsequent stent insertion. No other early complication was observed. After a median follow-up of 74 days (Range, 33-252 days), one of eight patients is still alive and 7 died of non-procedural causes. The grade of dysphagia improved from a mean of 2.9 to a mean of 1.6 and 2.0, respectively, depending on the follow-up period (scale 0-4). Esophageal reobstruction occurred in four patients due to food impaction (two patients) or tumor ingrowth into the stent through the wire mesh (two patients). Recanalisation of the obstructed stent lumen was achieved by endoscopic irrigation (two patients), laser therapy only (one patient) or diathermia with subsequent insertion of a conventional plastic endoprosthesis into the metal stent (one patient). The initial results are promising. The delivery system, the wide-bore diameter, the macroporous configuration and the low mass of the self-expanding stents would seem to be associated with a less traumatic insertion procedure and a lower rate of stent migration as compared with conventional prostheses. Technical improvement may be required for prevention of tumor infiltration. Controlled trials are warranted to determine the future role of metallic stents for palliation of esophagocardial tumors.

Adult↗