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Biomedical subjects

H Neuhaus

Publications and source records attributed to H Neuhaus.

At least 19 recordsLinked to original sources
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↗
PubMed1992

Endoscopic laser lithotripsy with an automatic stone recognition system for basket impaction in the common bile duct.

In a patient with a common bile duct stone 28 mm in diameter, the traction wires of two basket catheters fractured during endoscopic mechanical lithotripsy. Disintegration of the concrement and removal of the impacted baskets failed even after extracorporeal application of 8,000 shockwaves. Pulsed dye laser lithotripsy was carried out via a 250 microns fiber which was advanced to the stone through a 6 French ERCP guiding catheter. Lithotripsy could be safely performed under fluoroscopic control since the laser used provides an automatic cut-out system upon tissue contact. 3,600 of 11,800 applied pulses were emitted with the total power setting and complete disintegration of the calculus was achieved. The baskets and the fragments could be removed endoscopically in the same session. Laser lithotripsy with a stone recognition system would seem to improve the applicability and safety of intracorporeal lithotripsy even when performed without direct visual guidance.

Aged↗
PubMed1992

Prospective evaluation of the use of endoscopic retrograde cholangiography prior to laparoscopic cholecystectomy.

Preoperative cholangiography and subsequent removal of bile duct stones may increase the efficacy of laparoscopic cholecystectomy and reduce the rate of conversion to open cholecystectomy. Since there is little data on the incidence of choledocholithiasis in this group of patients, we undertook a prospective study on the routine performance of ERC in 288 patients selected for laparoscopic cholecystectomy. ERC succeeded in 264 of the 288 patients (91.7%) and showed a normal bile duct system in 227 (86.0%). Atypical bile duct anatomy was seen in eight patients. Open cholecystectomy was performed in seven of them but was judged to be absolutely necessary in only two cases (one patient each with Caroli syndrome and Mirizzi syndrome). ERC also revealed bile duct stones in 29 of 264 patients (11.0%) which had not been suspected on the basis of clinical, laboratory and ultrasonographic findings in nine cases (3.4%). EPT succeeded in all of the 29 patients with choledocholithiasis but open cholecystectomy was subsequently performed in four patients due to incomplete bile duct clearance (n = 3) or temporary bleeding after EPT (n = 1). The rate of ERC/EPT-related morbidity was 2.8%. It is concluded from a risk-benefit analysis in these patients that ERC should be restricted to patients with suspected bile duct stones. Following this strategy, small ductal concrements and bile duct abnormalities will be missed in 6.4% of cases but the clinical relevance of these findings is still unclear. In patients with combined gallbladder and common bile duct stones, preoperative EPT plus subsequent laparoscopic cholecystectomy appears to be an effective and time-saving therapeutic regimen which should be compared with open cholecystectomy plus common bile duct exploration in future studies.

Bile Duct Diseases↗
PubMed1992

[Role of cholangiography in laparoscopic cholecystectomy].

Cholangiography in laparoscopic cholecystectomy is indicated for the detection of bile duct stones and for visualization of the biliary anatomy in particular cases. For a selective approach patients with gallbladder stones can be split into groups with a low, an intermediate and a high probability of choledocholithiasis by use of ultrasonographic and laboratory parameters. In this respect, the choledochal diameter is the most accurate criterion for the prediction of duct stones. A narrow lumen, detectable in almost one-half of the patients, indicates a less than 4% incidence of duct stones. Cholangiography seems to be unnecessary in this low risk group. However, endoscopic retrograde cholangiography (ERC) or intraoperative cholangiography is indicated in patients with a 7-12 mm width of common bile duct and/or an elevated serum bilirubin level due to 10-50% risk of choledocholithiasis. There are several therapeutic options in case of detected duct calculi. To date, laparoscopic bile duct clearance can not be reliably performed. In about 15% of the patients an even larger choledochol diameter is associated with a high chance of bile duct stones. ERC and in case of detected stones endoscopic papillotomy (EPT) should be routinely performed in these patients to facilitate elective laparoscopic cholecystectomy.

Cholangiography↗
PubMed1991

[Endoscopic papillotomy (sphincterotomy) in the 1990-s].

This review summarizes the past history and presence of endoscopic papillotomy (EPT, sphincterotomy) in the treatment of biliary and pancreatic tract diseases. The indications of the different techniques used, and the comparison of the effectiveness of EPT with that of the traditional surgical treatment is also discussed. Based on the results, EPT is an up-to-date technique with good effectiveness, low risk for patients and widening indication range. EPT in the future, will play a determining role in the effective treatment of biliary and pancreatic tract diseases.

Ampulla of Vater↗
PubMed1991

Cloning and expression of cDNAs for the alpha subunit of the murine lymphocyte-Peyer's patch adhesion molecule.

cDNA clones encoding the alpha chain of the murine lymphocyte-Peyer's patch adhesion molecule (LPAM), which is associated with lymphocyte homing, have been isolated by screening with the human VLA-4 (alpha 4h) probe. Several alpha 4 antigenic determinants were identified on COS-7 cells after transfection. From overlapping clones, approximately 5 kb of contiguous nucleotide sequence have been determined, encoding a protein sequence of 1039 amino acids for the LPAM alpha chain (alpha 4m). LPAM is a member of the integrin family of cell-surface heterodimers, and alpha 4m is the murine homologue of the human alpha 4 h chain. The two proteins have a total sequence similarity of 84%, with an almost perfect conservation (31/32 amino acids) in the cytoplasmic domain. Like alpha 4h, alpha 4m is distinct from other integrin alpha chains because it has neither an I-domain nor a COOH-terminal cleavage site. The positions of the characteristic Cysteine residues are conserved, and a putative protease cleavage site is located near the middle of the protein sequence. The NH2-terminal part of the protein contains seven homologous repeats, and three of them include putative divalent cation-binding sites. These sites are among the most conserved between the alpha 4m sequence and other alpha chains, and may therefore be involved in the binding of integrin alpha and beta chains. An additional cDNA clone was isolated which shares a sequence of perfect homology with the alpha 4m encoding cDNAs, but has a unique 3' poly-A end. This observation correlates with the fact that three discrete murine RNA bands are observed in Northern blot experiments using alpha 4m as a probe, whereas only two human RNA species are described for alpha 4h, indicating a higher complexity for murine than for human sequences.

Amino Acid Sequence↗
PubMed1991

[Self-expanding and expandable bile duct prostheses].

The main problem of conventional endoscopic or percutaneous biliary drainage is the clogging of plastic endoprostheses. Therapeutic advances may be achieved by self-expanding or balloon-expandable braided or slit metal stents due to their large lumen and small surface area. Preliminary clinical studies show excellent early results but a divergent long-term clinical outcome depending on the selection of patients, the implantation technique or the type of the stent. If a long-distance overlap of biliary stenoses is achieved the metal stents may be superior to plastic prostheses due to a reduction of the risk of bile encrustation.

Bile Duct Neoplasms↗
PubMed1991

In vitro fragmentation of gallstones: comparison of electrohydraulic, electromagnetic and piezoelectric shockwave lithotripters.

To compare the fragmentation efficiency of three different shockwave systems, 63 human gallstone triplets were disintegrated in vitro using an electrohydraulic (MPL 9000, Dornier), an electromagnetic (Lithostar Plus, Siemens) and a piezoelectric (Piezolith 2300, R. Wolf) lithotripter. Since each stone triplet was obtained from the same gallbladder, the concrements of one such set were identical in physicochemical parameters. According to the maximal diameter, the calculi were divided into group A (6 to 15 mm) and group B (16 to 30 mm). Shockwave application was terminated when residual fragments measured 4 mm or less. Forty-five triplets were fragmented at energy settings mainly used in clinical treatment of patients with gallbladder stones (MPL 9000: 20 kV; Lithostar Plus: setting 9 (maximal); Piezolith 2300: setting 3). The fragmentation endpoint was achieved in group A (n = 3 x 36) with the Piezolith 2300 after median 150 (range = 50 to 500) pulses and with the Lithostar Plus after 150 (50 to 750) pulses compared with 500 (50 to 1,500) pulses using the MPL 9000 (p less than 0.01). In group B (n = 3 x 9) the Lithostar Plus (median = 750, range = 250 to 1,250 pluses) required fewer discharges than the Piezolith 2300 (1,250, 250 to 2,500 pulses; p less than 0.05) and the MPL (1,500, 500 to 1,600 [upper limit] pulses; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cholelithiasis↗