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W Häcki

Publications and source records attributed to W Häcki.

At least 19 recordsLinked to original sources
PubMed1992

[Endosonography: progress in the diagnosis of endocrine pancreatic tumors].

Diagnostic procedures for secreting endocrine pancreatic tumors comprise biochemical tests, CT scans, conventional abdominal sonography, angiography and occasionally MR imaging and isotope scans. Due to their small size, insulinomas and gastrinomas, the most common of these tumors, elude these diagnostic procedures. Preoperative sonography and CT scans were negative in over 60%, angiograms in 35% of the patients. The example of a patient with insulinoma demonstrates that in the future endosonography will offer itself as an accurate method with little risk.

Aged↗
PubMed1992

pH-feedback controlled infusions of ranitidine are no more effective than fixed-dose infusions in reducing gastric acidity and variability in antisecretory responses.

1. The antisecretory responses to pH-feedback controlled (maximum dose 800 mg 24 h-1) and fixed-dose (0.25 mg kg-1 h-1) continuous infusions of ranitidine were compared in a randomised, placebo-controlled, cross-over study in 10 healthy male volunteers. 2. To assess tolerance during repeated dosing with ranitidine, the same infusion regimens were given before and after 6 days oral dosing with ranitidine 300 mg four times daily. 3. With the pH-feedback controlled infusion of ranitidine the median % time (interquartile range) with pH greater than 4 in the 24 h period was 57% (45-76) before and 23% (17-34) after 6 days oral dosing (P less than 0.001). The respective values with fixed-dose infusion were 51% (38-63) and 26% (15-32) (P less than 0.002). 4. The median 24 h doses (interquartile range) of ranitidine given by feedback-controlled infusion before and after 6 days oral dosing were 675 mg (542-728) and 749 mg (709-760), respectively (P less than 0.01). The dose of ranitidine given by fixed-rate infusion was 423 mg (393-502) on both study days (P less than 0.001 vs feedback infusion). 5. Plasma gastrin concentrations remained slightly elevated after 6 days of oral ranitidine dosing, whereas pancreatic polypeptide plasma levels remained unchanged. 6. The antisecretory efficacy of infusions of ranitidine is significantly decreased by circadian stimuli and tolerance. Individually-adapted infusions of high doses of ranitidine were not superior to fixed-dose infusion of 0.25 mg kg-1 h-1 in overcoming this variability.

Adult↗
PubMed1991

[30-months extracorporeal electrohydraulic shock-wave lithotripsy of gallstones using the MPL-9000 at the Zurich University Hospital].

The effect of extracoporeal shockwave lithotripsy (ESWL) in combination with oral chemolitholysis on gallstone clearance was tested in a prospective study. We used a non-waterbath lithotripter, and the patients were treated without general anesthesia or intravenous analgesia. They solely received oral or subcutaneous premedication. Within the 30 months study-period 78 patients were selected according to the "Munich-criteriae". At the end of the study period 33 patients were free of stones, 20 patients had residual fragments, and 25 patients stopped the therapy prior to complete stone clearance because of compliance (n = 11), or methodological (n = 14) problems. This includes 3 patients in whom the ESWL had to be discontinued because of pain. No severe complications were seen with the exception of one attack of acute pancreatitis, from which the patient recovered. The rate of stone clearance was analyzed using the life-table calculation according to KAPLAN-MEIER to weigh the follow-up time of each patient. At 12 months it revealed a stonefree rate of 70% in patients who did not discontinue the treatment because of methodological problems. The advantage of ESWL is the possibility to treat gallstones without general anesthesia or intravenous analgesia. However, the patient-population must be highly selected, and there is the risk of recurrence.

Adult↗
PubMed1990

[The organization of gallstone lithotripsy using the MPL-9000 at the Zurich University Hospital, successes and failures. Initial results].

At Zurich fragmentation of gallstones is a joint venture between the Visceral Surgery Clinic, the Medical Clinic, Medical Policlinic, Radiodiagnostic Central Institute and Urologic Clinic. Lithotripsy is performed by a team from the Visceral Surgery Clinic with apparatus placed at their disposal by the Urologic Clinic. Indications for lithotripsy include symptomatic cholecystolithiasis, functioning gallbladder, and up to 3 gallstones of at least 10 mm and at most 30 mm diameter. Bile duct stones, acute cholecystitis, coagulopathy, pregnancy, aortic aneurysm and pacemakers are exclusion criteria. Patients spend two days in hospital, lithotripsy is performed without anesthesia, and outpatient follow-up is performed 1, 3, 6 and 12 months afterwards. Our experiences show that lithotripsy is more difficult and more treatments are needed if multiple gallstones are present. We had to perform cholecystectomy in 6 of a total 48 patients, mainly because of therapy resistant biliary pain due to stone fragments. The intraoperative findings did not correspond to the ultrasonic examination before lithotripsy in two of the patients who underwent cholecystectomy. Histologic examination of the six gallbladders in the surgical cases showed no abnormality. After an average treatment duration of 209 days, 9 of 48 patients are stone-free, 15 patients show improvement, in 14 patients no distinct reduction of fragments could yet be shown in recent follow-ups and 4 patients have not yet been reached for follow-up. Of the 230 patients examined lithotripsy was indicated only in 48 (21%) cases.

Adult↗
PubMed1989

[Experimental pancreatic duct occlusion with polyurethane].

Pancreatic transplantation requires an effective method to manage exocrine secretion. A new technique to eliminate the exocrine function of the pancreas by obstruction of the duct with polyurethane was investigated in terms of function, outcome and morphology. Polyurethane is an alcoholic solution of block copolymers with the property of polymerizing within 5-10 min. In this study the in-situ pancreatic tail model in dogs was utilized, the pancreatic duct was cannulated and injected with 2-3 ml of polyurethane. As a result, complete atrophy and fibrosclerosis of the exocrine tissue was obtained leaving islets well vascularized and functioning for the entire experimental periods. All animals remained normoglycemic and showed normal K-values. Amylase levels were found to be maximally elevated at 24 h and returned to normal within 2 weeks after duct occlusion. Insulin, glucagon and somatostatin levels remained normal. Because of its ability to effect a complete occlusion of the pancreatic ducts with subsequent atrophy of the exocrine gland and without notable disturbance of endocrine function, we feel that polyurethane solution is superior to previously used materials for this purpose.

Animals↗
PubMed1987

Comparative diagnostic value of the calcium-pentagastrin test versus the tolbutamide test in a patient with a somatostatinoma.

We describe a patient with a small somatostatinoma of the papilla of Vater without clinical evidence for diabetes mellitus, diarrhea, steatorrhea, or cholelithiasis, showing normal plasma basal levels for somatostatinlike immunoreactivity. The diagnosis was based on histologic and immunohistochemical analysis of tumor tissue and hypersomatostatinemia induced by the calcium-pentagastrin test. Before removal of the tumor both diagnostic tests recommended for the detection of a somatostatinoma, a tolbutamide test and a calcium-pentagastrin test, were performed. Whereas the calcium-pentagastrin test provoked a markedly elevated plasma somatostatin level in association with a depressed plasma neurotensin level, the tolbutamide test surprisingly did not. After removal of the tumor the calcium-pentagastrin test no longer induced hypersomatostatinemia. Further studies are needed to determine whether the calcium-pentagastrin test is a more reliable diagnostic test than the tolbutamide test in somatostatinomas with normal plasma basal levels.

Adenoma, Islet Cell↗
PubMed1983

Immunogenicity of a hepatitis B subunit vaccine in hemodialysis and in renal transplant recipients.

A hepatitis B subunit vaccine was given to 59 medical staff members, 106 hemodialysis patients and 28 renal allograft recipients. The vaccine consisted of formalin-inactivated hepatitis Bsurface antigen (HBsAg) and was given in 3 doses (times 0, 1 and 6 months) of 20-40 micrograms. Some of the vaccinees received anti-HBs antibodies together with the first vaccine dose (active/passive vaccination). One month after the last infection, 93% of the medical staff members who had received active/passive immunisation and 97% of those who had received active immunisation had detectable anti-HBs antibodies with mean titers ranging from 1:512 to 1:1024. In the group of hemodialysis patients antibodies were detectable in 63-65% of the individuals who had received active or passive/active immunisation in mean titers between 1:32 and 1:64. Finally, only 32% of the renal allograft patients developed measurable anti-HBs antibodies, the titers of responders being still lower than in the hemodialysis patients. Side effects occurred following 10% of all vaccine injections and were always mild in nature. Within the 12 months observation period period following the first vaccination, 3 HBV events occurred in the 193 individuals: One aclinical case detected by a transient seroconversion against the hepatitis B core antigen, one anicteric and one icteric hepatitis case. The data illustrate the difficulties for active immunisation against hepatitis B of hemodialysis patients or of renal transplant recipients.

Antibodies, Viral↗
PubMed1981

[Release of pancreatic polypeptide induced by cholecystokinin in man and dog].

In four healthy volunteers increasing doses of intravenous CCK-33 induced an increase in plasma PP concentration measured by RIA. PP concentration rose from a basal level of 67 +/- 15 pmol/l to 198 +/- 45 pmol/l with 2 IDU/kg/h (p less than 0.05). In four mongrel dogs equipped with Thomas cannulas, the same doses induced a more pronounced rise in plasma PP (p less than 0.01). It is concluded that intravenous CCK-33 induces the release of PP in man and dog in a dose-dependent manner.

Animals↗
PubMed1981

[Diagnosis and occurrence of viral esophagitis].

Upper gastrointestinal endoscopy in 500 consecutive patients from medical, oncological and surgical wards showed a 1% incidence of viral esophagitis. The 5 reported cases could not be distinguished either on clinical or on endoscopic grounds from reflux esophagitis. Brush cytology served in all but one case to diagnose viral esophagitis. Identification of the virus was possible in 4 cases (3 herpes simplex, 1 cytomegaly). Viral esophagitis was mainly a complication in severe underlying disease.

Adult↗
PubMed1981

Diagnostic value of the fecal chymotrypsin test in pancreatic insufficiency, particularly chronic pancreatitis: correlation with the pancreozymin-secretin test, fecal fat excretion and final clinical diagnosis.

The diagnostic value of the fecal chymotrypsin test (FCT) was reevaluated with regard to (a) proved pancreatic hypofunction of different severity (183 pancreozymin-secretin tests); (b) the final clinical diagnosis, and (c) fecal fat excretion (208 patients with chronic pancreatitis; CP). Progressive pancreatic disease (cancer, CP) was mainly associated with moderate or severe pancreatic hypofunction (119/138; 86.2%) and a low incidence of false-normal FCT values (14/138; 10.1%). Miscellaneous disorders (mainly reversible pancreatic hypofunction) were mainly associated with slight pancreatic hypofunction and a high incidence of false-normal FCT values (17/45; 37.8%). Pancreatic steatorrhea (greater than 10 g/day) was found only in patients with markedly depressed FCT values. Progressive deterioration of pancreatic function was demonstrated by repeated FCT in CP (n = 220).

Celiac Disease↗
PubMed1981

The release of pancreatic polypeptide by exogenous CCK in man and dog.

4 healthy volunteers received commercial 20% pure CCK-33 in 4 consecutive doses of 0.5, 1.0, 2.0, 4.0 IDU/kg/h. blood samples were assayed for pancreatic polypeptide (PP) by radioimmunoassay. Plasma PP concentrations increased stepwise from a basal level of 67 +/- 15 pmol/l to a maximum of 198 +/- 46 pmol/l (p less than 0.05). In 4 mongrel dogs with Thomas cannulas, the same doses of 99% pure CCK-33 were successively infused. Plasma PP concentrations rose stepwise with each dose from 44 +/- 7 to 259 +/- 43 pmol/l (p less than 0.02). This rise significantly correlated with pancreatic protein secretion (p less than 0.01). It is concluded that intravenous CCK-33 induces the release of PP in man and in dog, in a dose-dependent manner.

Animals↗
PubMed1978

[Gastric secretion and gastrin values following portocaval and splenocaval shunts in the rat].

The basal and gastrin-stimulated gastric acid output was measured in rats with a distal splenocaval shunt. In addition, serum gastrin levels were determined in rats with splenocaval and portacaval shunts. The rise in gastric acid output with increasing gastrin dosage was the same in rats with splenocaval shunt as in the controls. Serum gastrin levels were not influenced by portocaval or splenocaval shunting.

Animals↗
PubMed1976

A new look at the plasma disappearance of sulfobromophthalein (BSP): correlation with the BSP transport maximum and the hepatic plasma flow in man.

In order to improve the clinical usefulness of the plasma disappearance curve of sulfobromophthalein (BSP), its components were analyzed in 26 control subjects, in 28 patients with cirrhosis, and in 13 cases of miscellaneous liver abnormalities. The uncorrected initial disappearance rate (ki) was found to discriminate best between the control and the patient groups. The second exponential component (k2) was linearly correlated with the transport maximum (Tm) on a double logarithmic plot, but appeared to be independent of the estimated hepatic plasma flow (EHPF). An interpretation of this relationship was possible, when based on a model having saturation kinetics for biliary excretion. The first exponential component (ki) appeared primarily determined by hepatic perfusion. These relationships may contribute to a better understanding and more rational use of dye excretion tests as measures of hepatic function. The data also add to our knowledge about the nature of the excretory defect in cirrhosis.

Adult↗
PubMed1974

A practical approach to quantitate hepatic excretory function.

A statistical comparison of different BSP tests was carried out in normal subjects and in patients with various degrees of chronic liver damage. Only the logarithm of the BSP retention correlated linearly with the physiologically more meaningful determination of the maximal excretory capacity of the liver (BSP Tm, Wheele's method). A double logarithmic transformation was required to correlate the second exponential component of the BSP plasma disappearance curve (k(2)) with the BSP Tm. When the limitations of these methods are kept in mind, the observed statistical relationships can be used to express hepatic functional deterioration in more physiological terms.

Humans↗