Biomedical subjects
Publications and source records attributed to L Greiner.
Shockwave therapy of bile duct stones is not dependent on difficult preconditions concerning stone-volume and -composition or subsequent lythic therapy. Its main indication is failure of endoscopic sphincterotomy (EST). Shockwave lithotripsy of bile duct stones--which may even be carried out even instead of EST in specific cases--is with a success rate of 80 to 95% as effective as shockwave lithotripsy in urology.
The endoscopic examination of a patient with gastrointestinal bleeding unexpectedly revealed a cholecysto-antral fistula with incipient penetration of a gallstone into the stomach (and presumably intermittent bleeding from the fistula rim). As endoscopic extraction was not possible and the stone impacted in the fistula was visible in the ultrasound scan extracorporeal shock-wave lithotripsy was carried out. An electrohydraulic lithotripter was used and 1,913 shock waves were applied at a maximum of 26,000 volts. In a single treatment session the stone was disintegrated completely into fragments small enough for spontaneous elimination. No sedative or analgesic medication was required. There was no evidence of any complications or side-effects following the ESWL.
With the aim of analysing the frequency of gastrointestinal (GI) metastases identified by endoscopic procedures, a survey was conducted by questionnaire, which was completed by 34 of 127 medical departments. Peritoneal carcinosis and direct tumor extension were disregarded. One GI metastasis (duodenum) was verified among 3477 upper GI tract endoscopies. Primary site was cutaneous melanoma. In another case metastatic origin is discussed (esophagus). Considering the average frequency of 102 upper GI tract endoscopies performed by the collaborating centers, one case of gastroduodenal metastasis could be expected every 17 (34) months in these institutions. 1634 examinations of the colon and rectum did not reveal any metastatic tumor growth. A longterm study is planned to provide further statistically reliable prevalence data.
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Since 1985/86, more than 200 patients with problematic intra- and extrahepatic bile duct stones were treated with ESWL. Results are excellent and comparable with ESWL's success-story in urinary stone disease, abandoning widely open surgery for bile duct stones. In gallbladder-stone treatment, ESWL (always combined with bile acid litholysis) is only promising or successful in a carefully selected subset (10 to 15%) of all symptomatic patients (with good gallbladder contractility, limited stone volume and sonolucent stones).
Ultrasound is an indispensable tool for preliminary diagnosis ("filter function"), during treatment ("monitoring function") and in the follow-up examinations ("follow-up function") after shock-wave lithotripsy of gallstones. It permits rapid and reliable assessment of the therapeutic outcome and early identification of complications, which present-day experience has shown to be rare.
Ultrasound is an indispensable tool for preliminary diagnosis ('filter function'), during treatment ('monitoring function') and in the followup examinations ('follow-up function') after shock wave lithotripsy of gallstones. It permits rapid and reliable assessment of the therapeutic outcome and early identification of complications, which experience to date has shown to be rare.
Using a subtile examination technique genuine information can be obtained from the interior of a gallstone--at least to a depth of 15 mm. This information should provide an indication of the homogeneous (crystalline) or inhomogeneous (non-cholesterol) structure of the stone. Further systematic use of differentiating gallstone ultrasonography could become a useful additional decision making criterion for selection of gallstones suitable for conservative treatment.
The use of clozapine, a unique antipsychotic drug, has been restricted due to a 1-2% incidence of drug-induced agranulocytosis. Metabolic activation of clozapine in neutrophils or stem cells could be the molecular mechanism underlying this side effect. Clozapine oxidation by human myeloperoxidase and horseradish peroxidase was evident from the disappearance of the UV absorbance at 290 nm. High performance liquid chromatography analysis revealed the formation of at least four radioactive peaks as a result of clozapine metabolism, including radioactivity coeluting with the protein. The tight association of radioactivity with the enzymatic protein was metabolism-dependent. This protein binding, which correlates with the total metabolism of clozapine, was reduced in the presence of glutathione and was absent in the presence of ascorbate. Similarly, in the presence of both reducing agents, the metabolite peaks in the high performance liquid chromatography radiogram, which are not associated with protein, disappeared. In contrast, in the presence of glutathione, two additional metabolites were found that could be isolated and identified by NMR and mass spectroscopy as clozapine glutathionyl adducts. Evidence for one-electron transfer reactions or the intermediate formation of a clozapine radical during the peroxidase-mediated metabolism of clozapine stems from the observation of thiyl and ascorbyl radicals in the presence of glutathione and ascorbate, respectively. The ascorbyl radical was detected by direct ESR spectroscopy in a peroxidase system. Its steady state concentration was significantly increased in the presence of clozapine. Glutathionyl radical formation was demonstrated by radical trapping with 5,5-dimethyl-1-pyrroline N-oxide in a peroxidase system. Again, the radical adduct concentration was significantly increased in the presence of clozapine. Similarly, when oxygen consumption was measured in peroxidase systems in the presence of glutathione or NADPH, the rate of oxygen uptake was markedly enhanced upon addition of clozapine. Thus, the data support the possibility of clozapine activation to free radical metabolites, which may cause oxidative stress or lead to adduct formation. Further, it can be concluded from these data that radical scavengers such as ascorbic acid, when coadministered with clozapine to patients, may reduce oxidative stress and protein adduct formation.
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All stools passed on the first 3 days after extracorporeal shock-wave lithotripsy of gallbladder stones in 21 patients were collected and examined for the presence of stone fragments. A total of 555 fragments varying in number per patient (4-69) and in size (maximum diameters from 0.5-8.0 mm) were recovered by sieving aqueous suspensions of the feces. All 482 fragments less than or equal to 3.0 mm left the biliary tract without any clinical symptoms, as did the three largest fragments with maximum diameters of 7.0-8.0 mm and almost all of the 70 fragments measuring 3.5-5.0 mm. During the observation period, four episodes of biliary complaints were recorded in three patients in whom fragments with maximum diameters of 3.5-5.0 mm were found. The only chemical abnormality was a temporary elevation of lipase activity to twice the normal range in 1 case. All fragments were identified as gallbladder stones by infrared spectroscopy on the basis of their (varyingly high) cholesterol content. By macroscopic criteria, most of the fragments were from mixed stones; therefore, provided there is a functioning gallbladder and sufficiently fine fragmentation, successful extracorporeal shock-wave lithotripsy does not seem to be limited to pure cholesterol stones.
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Extracorporeal lithotripsy (EL) was undertaken in 50 patients (mean age 73.7 years; range 29-90 years) with extrahepatic and, in five, with intrahepatic gallstones, the usual endoscopic methods having been unsuccessful in removing the stones. Occasionally stone fragments were passed spontaneously, but in most they had to be removed endoscopically, in 48 (96%) with extrahepatic and in three (60%) with intrahepatic stones. Biliary tract or gallbladder infections occurred after the lithotripsy and associated local litholysis in seven of the 48 with extrahepatic (14%) and three of the five (60%) with intrahepatic stones. There was one hospital death. The results indicate that EL has definite advantages over surgical treatment in these patients, who are usually elderly and in whom surgical intervention is more risky.
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The energy expenditure of lower (group 1) and upper socioeconomic group females (group 2) from a marginal community in Guatemala City was determined by using the doubly labelled water method. Energy expenditure values were 1925 +/- 66 (mean, SEM) kcal/d (group 1) and 2253 +/- 145 kcal/d group 2 (p less than 0.03). About half of this difference can be attributed to size.
Between September 1986 and April 1987, extracorporeal shock-wave lithotripsy, supplemented by oral chemolitholysis, was undertaken on 157 patients with symptoms of gallstones. Partial or complete stone fragmentation was achieved in 148 (94.3%). Freedom from stones was maintained under continuous chemolysis treatment for an average observation period of 8.5 weeks in 31 (19.7%). Considerable fragment reduction was obtained in 97 (61.8%), of whom 26 (16.6%) were demonstrated to have only minimal stone residues. Insufficient fragmentation and (or) no response to litholysis occurred in 29 (18.5%). These preliminary results suggest that, if there are moderately sized (less than 25 mm) and only a few (1-3) noncalcified cholesterol stones, these two methods in combination promise to be an effective alternative to cholecystectomy.