M-mode echocardiographic diagnosis of dilated cardiomyopathy in giant breed dogs

M-mode echocardiograms were recorded from 62 giant breed dogs without historical, clinical, electrocardiographic and roentgenologic signs of heart disease, from six dogs with asymptomatic dilated cardiomyopathy (DCM, NYHA class I), and 13 dogs with symptomatic DCM (NYHA class III-IV). There was a general trend that several echocardiographic parameters were significantly in control Great Danes as compared to Newfoundlands and Irish Wolfhounds. There were substantial differences in left ventricular size both in systole and diastole and in systolic indices of the left ventricle between the control group, the asymptomatic dogs and symptomatic dogs with DCM (P = 0.0001). There was also a significant decreased in the interventricular septum thickness (P = 0.0001) and left ventricular free wall thickness in systole (P = 0.002) and diastole (P = 0.005) between the three groups. Furthermore, the left atrial/aortic ratio was significantly different between the three groups (P = 0.0001). It was concluded that this study established echocardiographic reference values in giant breed dogs which may be useful in the study of heart diseases in giant breed dogs.     

Serum malondialdehyde: possible use for the clinical management of chronic hepatitis C patients

BACKGROUND: A high risk of developing sludge or gallstones has been associated with pregnancy. The aim of this study was to relate the prevalence of sludge and gallstones during and shortly after pregnancy to fasting gallbladder volume as an indicator of gallbladder motility. METHODS: The population included 114 apparently healthy pregnant women from the Outpatient Clinic of Obstetrics of a large regional hospital and from the practices of regional midwives. Ultrasonography of the gallbladder was performed at weeks 15, 25, and 35 of gestation and at week 3 and month 6 postpartum. RESULTS: At gestational week 15, 3 women had gallstones and 10 had sludge (mean volume, 33.8 ml), and 99 women had a normal gallbladder (mean volume, 30.5 ml). At week 25, 1 woman with a normal gallbladder formed gallstones and underwent cholecystectomy shortly after, and 22 women had sludge, of whom 13 had a normal gallbladder at first examination (mean volume, 33.2 ml). In 88 women with normal gallbladders (of whom 2 had sludge at week 15) mean volume was 31.9 ml. At week 35, 2 women had gallstones, and 21 had sludge (mean volume, 30.5 ml). In the remaining 79 women the gallbladders were clear (mean volume, 29.5 ml). Eight women developed sludge and two women gallstones in normal gallbladders at week 25. Seven women with sludge at week 25 had a normal gallbladder at week 35. Three weeks postpartum only 10 of 100 women had sludge (mean volume, 29.1 ml). Of these 10, 9 women had a normal gallbladder at week 35. Twenty of 21 women with sludge at week 35 had normal gallbladders week 3 postpartum. Gallstones found at week 35 had disappeared. In the women with a normal gallbladder the mean volume was decreased to 19.7 ml (P < 0.0001). Six months postpartum, sludge was found in 6 (mean volume, 18.4 ml) of 93 women (mean volume, 20.3 ml), of whom 5 had a normal gallbladder at week 3 postpartum. Only 61 women showed a normal gallbladder at each examination of the study. No differences in patient characteristics were found between women with normal gallbladders and those with sludge or gallstones. CONCLUSIONS: Fasting gallbladder volume was increased in all pregnant women. This could not explain the formation of sludge or gallstones during gestation. Decrement of gallbladder volumes after delivery was faster in normal, clear gallbladders. More than a prerequisite, increased fasting gallbladder volume seemed to be a permissive factor of pregnancy-associated gallstone formation.     

Reduced contractility and histological changes in the gallbladder due to portal hypertension in a hamster cirrhosis model

BACKGROUND/AIMS: Little is known about the relationship of portal venous pressure to contractility and histological changes in the gallbladder. In this study, we investigated the relationship between portal hypertension and contractility and histological changes in the gallbladder in a hamster cirrhosis model. METHODS: Liver cirrhosis was induced in the hamsters (n = 20) by thioacetamide (TAA). Portal venous pressure was directly measured using a pressure-measuring instrument. The contractility of the gallbladder was appraised by the diameter before and after caerulein treatment. Gallbladder wall thickness and vessel areas in tissues were evaluated in relation to the portal venous pressure. RESULTS: The portal venous pressure, gallbladder wall thickness with submucosal edema and area of vessels in the gallbladder wall in the cirrhosis group were significantly increased compared with those in the control group (n = 20, receiving saline instead of TAA). The gallbladder contraction rate in the cirrhosis group was significantly decreased compared with that in the control group. In the cirrhosis group, there were positive correlations between the portal venous pressure and the gallbladder contraction rate, gallbladder wall thickness, and area of vessels. CONCLUSIONS: In the gallbladders of experimental cirrhotic hamsters, portal hypertension caused dilatation of the vessels as well as submucosal edema, and was an important factor in the increased thickness and reduced contractility of the gallbladder wall.     

Biliary dyskinesia: natural history and surgical results

Patients with biliary dyskinesia have symptoms consistent with biliary colic and an abnormal gallbladder ejection fraction (GEF) in the absence of cholelithiasis. Cholecystokinin hepatobiliary scan quantifies gallbladder function and may assist in selecting patients with acalculous biliary pain who would benefit from cholecystectomy. Seventy-eight patients with an abnormal GEF (< 35%) on cholecystokinin hepatobiliary scan without cholelithiasis were studied retrospectively. Patients were divided into groups based on diagnosis and treatment. In Group I, the patients who underwent cholecystectomy, 80 per cent (35 of 44) had complete symptomatic resolution whereas the remaining 20 per cent (9 of 44) had symptomatic improvement. Pathology reports demonstrated chronic cholecystitis in 95 per cent of specimens. Group II were patients with symptoms attributable to biliary dyskinesia, but did not undergo cholecystectomy. Persistence of symptoms was noted in 75 per cent (18 of 24) of patients whereas 25 per cent (6 of 24) had symptomatic resolution without any treatment. Group III consisted of patients with an abnormal ejection fraction who had improvement of symptoms after treatment for an alternative diagnosis (n = 10). These findings suggest that an abnormal ejection fraction does not always indicate gallbladder disease. Alternative diagnoses must be investigated and treated. Patients with persistent biliary type symptoms in combination with an abnormal GEF in the absence of other attributable causes can expect a favorable response to cholecystectomy.     

Echogenic fetal bowel and calcified meconium in a fetus with trisomy 21

A case of acute cholecystitis in an immunosuppressed patient with hepatocellular dysfunction is reported. The diagnostic dilemmas posed by the lack of specific sonographic findings, the possibility of acute gallbladder disease without early cystic duct obstruction, and the absence of clear guidelines for the interpretation of delayed appearance of the gallbladder on hepatobiliary scintigraphy in this subgroup of patients are discussed.     

Porcelain gallbladder associated with primary biliary adenocarcinoma in a dog

A 9-year-old spayed female Poodle was admitted because of vomiting of 3 weeks' duration, lethargy, and anorexia. Palpation of the cranial portion of the abdomen elicited signs of pain. Principal laboratory abnormalities included mild segmented neutrophilia, lymphopenia, high serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities, and hyperbilirubinemia. Radiography revealed foamy appearing areas of mineral opacity in the region of the gallbladder. Ultrasonographically, a hyperechoic structure with acoustic shadowing was seen in the same region, and extrahepatic bile ducts were distended. Cholecystectomy was performed. The gallbladder wall felt thicker than normal and was bluish-white. Multiple choleliths were found in the gallbladder and extrahepatic bile ducts. Histologic examination revealed chronic proliferative lymphoplasmacytic cholecystitis with mineralization and a well-differentiated adenocarcinoma of the gallbladder neck. A diagnosis of porcelain gallbladder was made. The dog recovered without complications and was healthy 14 months after surgery. To our knowledge, porcelain gallbladder has not been reported in dogs. In human patients, it is defined as intramural mineralization of the gallbladder commonly associated with gallbladder neoplasia. Early recognition is important for appropriate surgical treatment.     

Treatment of fulminant hepatic failure with intravenous prostaglandin E1

We studied 32 patients with the thickened lesions of the wall of the gallbladder by using dynamic MRI. We tried the differential diagnosis of gallbladder lesions according to the time intensity curve (TIC) and enhanced pattern. TIC of carcinoma was elevated more seeply from plain to arterial phase than the inflammatory diseases. The Inflammatory diseases were keeping three-layer structures of the wall of the gallbladder, but gallbladder carcinoma destroys the wall-structure. We could diagnose as direct liver invasion of the carcinoma clearly. We could exactly diagnose adenomyomatosis in dynamic MRI by small low intensity spots within the wall of the gallbladder. In the patients with gall stones, the wall of the gallbladder were more clearly observed in dynamic MRI compared with US and EUS.     

Common foot deformities in infancy and childhood

An enzymatic-fluorimetric method using a highly purified 3alpha-hydroxysteroid dehydrogenase (Sterognost-3alpha, Nyco) was used to determine fasting serum bile acid concentrations on 49 occasions in 43 patients with various liver diseases. A two-hour postprandial bile acid determination was carried out on 29 occasions in 27 of the patients. Fasting bile acid concentration correlated significantly both in cholestatic hepatobiliary and in parenchymatous liver disease to serum bilirubin and aspartate aminotransferase (ASAT) but not to alanine aminotransferase (ALAT), alkaline phosphatase, or albumin. The two-hour postprandial bile acid concentration was above normal in all patients with biochemical and/or histological signs of hepatobiliary disease, also when fasting concentration was within normal limits. In parenchymatous liver disease correlations existed between the two-hour postprandial bile acid concentration and bilirubin, ASAT, and ALAT. The sensitivity of serum bile acid estimation was compared to other liver function tests. Both the fasting and the postprandial serum bile acid concentrations tended to be more sensitive tests of hepatobiliary disease than bilirubin, ASAT and ALAT.     

Mastoiditis: a case-based review

The ultrasound (US) scans of eleven patients with histologically proven xanthogranulomatous cholecystitis have been reviewed. The thickness of the gallbladder (GB) wall, echogenicity of the thickened GB wall, the presence of intramural nodules, gallstones, pericholecystic fluid, loss of wall definition with the liver, and intrahepatic ductal dilatation were specifically assessed by two radiologists. The range of thickness of the GB wall was 3-20mm (mean, 11.2 mm). Thickening was diffuse in nine cases and focal in two. The thickened GB wall, excluding intramural nodules, was echogenic in seven, isoechoic in three and hypoechoic in one, compared with hepatic echogenicity. Intramural nodules were found in eight cases. These were discrete, oval or flat, and of low echogenicity. These ranged in size from 6 to 12 mm (mean, 10.5 mm). Gallstones were present in six cases and there was intrahepatic duct dilatation in two of these. Definition between the liver and the GB was obliterated in seven cases. One case of GB perforation, confirmed at operation, demonstrated pre-operatively a GB wall defect and connection with the surrounding pericholecystic fluid. Pericholecystic fluid was absent in the other 10 cases. Xanthogranulomatous cholecystitis presents ultrasonically as GB wall thickening, and the majority of cases in this series also demonstrated intramural hypoechoic nodules. These findings can be helpful in the diagnosis of xanthogranulomatous cholecystitis.     

Total serum sialic acid is a general disease marker rather than a specific tumour marker in dogs

The aim of the present study was to examine the levels of total sialic acid (TSA) in serum of clinically healthy dogs and dogs with various diseases to evaluate the usefulness of TSA as a tumour marker. TSA levels in clinically healthy dogs were not different between sexes, but pregnant and lactating dogs had higher mean (+/- standard deviation (SD)) TSA levels than clinically healthy female dogs (642 +/- 78 vs. 495 +/- 73 mg/l, P < 0.001). Eighty-eight dogs with different tumours (54 malignant and 34 benign tumours of different tissues) had higher mean TSA levels than 148 clinically healthy dogs (675 +/- 143 vs. 498 +/- 75 mg/l, P < 0.01). Fifty dogs with other diseases excluding tumours (skin, urinary system, and gastrointestinal diseases, pyometra, other inflammatory diseases, and Cushing's syndrome) had slightly higher TSA levels than the tumour-bearing dogs (730 +/- 159 mg/l, P = 0.02). TSA levels in dogs with malignant tumours did not differ from dogs with benign tumours (682 +/- 144 vs. 664 +/- 142 mg/l, P = 0.73). A receiver-operating characteristic (ROC) plot revealed a maximum sensitivity and specificity combination of 69% and 91% (TSA cut-off concentration 595 mg/l) in distinguishing between healthy dogs and dogs with tumours. When evaluating TSA measurements to distinguish dogs with other diseases from dogs with tumours, a maximum sensitivity and specificity combination of 50% and 75% was found (cut-off concentration 761 mg/l). WHO staging of mammary tumours revealed an increase in TSA levels with increasing stage (P < 0.0001, rs, = 0.62). In conclusion, the nonspecificity of increases makes TSA determinations unsuitable as a tumour marker. TSA levels seem instead to be a general disease marker. Whether serial TSA measurements could be used in the follow-up of dogs operated for malignant tumours should be further investigated.     

Biliary sludge formation during enteral nutrition: prevalence and natural history

BACKGROUND: Total parenteral nutrition is an etiologic factor in the formation of biliary sludge. We studied whether enteral nutrition is also a risk factor for sludge. METHODS: Fifty patients with a needle catheter jejunostomy (NCJ) placed during a major abdominal operation underwent preoperative and weekly postoperative ultrasonography until NCJ feedings were discontinued (1 to 6 weeks). RESULTS: All patients were men. The mean age was 63.2 +/- 1.6 years. Fourteen asymptomatic patients (28.0%) had biliary sludge within 2 weeks of beginning enteral feedings through a NCJ. Complete ultrasonographic resolution of sludge was observed in 13 of the 14 positive patients within 1 to 2 weeks of resuming an oral diet. One patient was lost to follow-up after 14 week; a positive sonogram had persisted but the patient remained asymptomatic. During the period of observation, no other patient had signs of biliary tract disease. CONCLUSIONS: (1) Biliary sludge may form in some patients during enteral feeding with NCJ. (2) Sludge is cleared by the gallbladder once an oral diet is resumed. (3) There appears to be little risk of complications during postoperative enteral feeding.     

Monitoring trends in prenatal diagnosis of Down''s syndrome in England and Wales, 1989-92

A prospective and multicenter study was performed to determine the efficacy and tolerance of ursodeoxycholic acid (UDCA) in the treatment of gallstones and biliary sludge. Criteria for entry into the trial were radiolucent gallbladder stones; until 20 mm of size and visualization of the gallbladder by oral cholecystography. Too were treatment the patients with persistent biliary sludge (PBS) defined by the persistence of the biliary sludge in two consecutive echography along three months. Without severe gallbladder disease. Then daily UDCA doses of 600 mg were suminstred divided in two postprandial times for a six months period. The control to the treatment were: basal ultrasonography (US) of the gallbladder and by follow-up gallbladder US for six months; clinical examination every month and cholecystography before and after the treatment. Of 110 admitted patients, 19 (17%) stopped the treatment for no-medical reasons and 91 (83%) arrived to the and point. After six months of treatment, complete dissolution was observed in 50% of the patients (46/91), partial in the 43% (39/91) and failed the treatment in 6.5% (6/91) who presented high density stones for computed tomography, CT (greater than 60 UH). According to pattern of lithiasis dissolution was complete in 100% (22/22) of the patients with PBS; 71.4% (10/14) in microlithiasis and 25% (14/55) in macrolithiasis. Minor adverse effects were acidism in the 7.7% (7/91) and diarrhea in the 1.1% (1/91). In the other hand, one patient presented acute pancreatitis (1/91; 1.1%), it must be discussed if was a complication of the lithiasis or an therapeutic effect. The UDCA was a safe and effective treatment without lethality in PBS and in microlithiasis while in case of macrolithiasis must be standardized response criterion, for example density stones for CT.     

Cholesteatosis of gallbladder (author's transl)

741 cholecystektomies were examined for cholesterosis. In 92% gallstones were present and in 8% there were no stones. Cholesterosis of the gallbladder was found in 0,9% of 4417 autopsies. It was combined with gallstones in 25% and in 75% it was not. There was no difference concerning the clinical symptoms between cholesterosis with and without stones in the surgical patients. Cholesterosis without stone presented the same picture as gallstones. In the autopsy material however no typical symptoms could be found indicating either cholesterosis with gallstones or without. In the histological examination 80,5% of the cases with gallstones in the surgical and autopsy group had inflammatory changes of the gallbladder wall whereas only 22% of the cases with stoneless cholesterosis showed these alterations. Fibrosis of the gallbladder wall however was found in 86,1% in cases with cholesterosis without stones and in 88% in cases with stones. From these findings the conclusion is made that cholesterosis is no well defined disease. Clinical symptoms seem to appear only when other factors, such as stones, inflammation or functional disturbances probably because of fibrosis of the wall, become manifest in addition.     

Increase in the chronically monitored cerebrospinal fluid pressure after experimental brain injury in rats

An enzyme-linked immunosorbent assay to detect thyroglobulin autoantibodies (TGAB) in canine serum was developed and validated. The test result for each sample was derived from the optical density readings (OD) and expressed as an Ab-score(%) calculated from three in-house calibrators. The assay specifically detected TGAB as judged from lack of response in the assay after samples had been incubated with specific antigen. Intra- and interassay coefficients of variation ranged from 2.0-4.9% and 4.6-9.9%, respectively. The detection limit, an Ab-score of 5.6%, was close to the median Ab-score of 10% observed in healthy dogs (n = 132). The median Ab-score of dogs with primary hypothyroidism and lymphocytic thyroiditis (n = 11), skin diseases (n = 35), and non-thyroidal diseases (n = 63) was 340%, 12%, and 8%, respectively. The prevalence of TGAB in hypothyroid dogs with lymphocytic thyroiditis (sensitivity) was 91% (95% confidence limits: 59%-99%). In dogs with dermatological diseases without lymphocytic thyroiditis the prevalence of TGAB was 3% corresponding to a specificity of 97% (95% confidence limit: 85%-100%). In dogs with non-thyroidal diseases and healthy dogs the prevalence of TGAB was 5% and 6%, respectively. The diagnostic accuracy of serum TGAB was evaluated by subjecting the data from 11 dogs with lymphocytic thyroiditis and 35 control dogs without lymphocytic thyroiditis to receiver-operating characteristic curve analysis. The area under the receiver-operating characteristic curve (W = 0.966; 95% confidence limit 87%-100%) was significantly higher than that of a worthless test (0.5) (P < 0.0001), thereby indicating that serum TGAB measurements distinguished between dogs with and without lymphocytic thyroiditis.     

Gallbladder wall thickening in dengue hemorrhagic fever: an ultrasonographic study

This study attempts to investigate whether gallbladder wall thickening (GBWT) measured by ultrasonography can be used in children as a reliable criterion to predict the onset of severe dengue hemorrhage fever (DHF). In this prospective study, we performed ultrasound examinations focusing on the gallbladder wall and the presence of intraperitoneal free fluid in 48 mild DHF cases (grades I-II) and 48 severe cases (grades III-IV). GBWT varied between 1 mm and 8 mm with a mean of 3.77 mm +/- 2.04 mm. The mean value of DHF grades I and II (2.39 mm +/- 1.48 mm) is significantly lower than that of grades III and IV (5.14 mm +/- 1.54 mm), p < 0.001. GBWT exceeded 3 mm in only 16 of 48 (33.3%) grade I-II patients and in 45 of 48 (93.8%) grade III-IV patients. A significant positive correlation was apparent between GBWT and the severity of illness, p < 0.001. Patients with ascites have significantly thicker gallbladder walls than those without, p < 0.01. In clinically confirmed DHF cases, the sonographic finding of GBWT > 3 mm to 5 mm, with 93.8% sensitivity, can be used as a criterion indicating the need for admission and monitoring. A GBWT of > or = 5 mm, with 91.7% specificity, is useful as a criterion for identifying DHF patients at high risk of developing hypovolemic shock.     

Use of DNA end joining activity of a Xenopus laevis egg extract for construction of deletions and expression vectors for HIV-1 Tat and Rev proteins

Blood gases were analyzed in dogs with pulmonary heartworm (HW) disease. The arterial oxygen tension (PaO2) in dogs with mild signs of dirofilariasis (mildly affected group, n = 48, 85.7 +/- 8.2 mmHg) and in dogs with signs of right heart failure (severely affected group, n = 13, 76.4 +/- 11.6 mmHg) was lower (p < 0.01) than in dogs without HW infection (HW-free group, n = 19, 91.5 +/- 7.3 mmHg). Only 2 dogs in the severely affected group had a PaO2 less than 60 mmHg. The arterial carbon dioxide tension (PaCO2, p < 0.01) and mixed venous O2 (p < 0.01) and CO2 (p < 0.01) tensions were lower, and alveolar-arterial oxygen difference (AaDO2, p < 0.01) was greater in the severely affected group than in the HW-free and mildly affected groups. Arterial pH and bicarbonate (HCO3-) concentrations were lower (p < 0.01) in both affected groups than in the HW-free groups. The anion gap level was not different among the 3 groups. Serum lactic acid level in the severely affected group was higher (p < 0.01) than in the HW-free and mildly affected groups. However, a slightly higher serum lactic acid concentration was found only in 2 dogs of the severely affected group (3.84 mmol/l and 3.82 mmol/l). The PaO2 (r = -0.62) and AaDO2 (r = 0.66) correlated significantly (p < 0.01) with mean pulmonary arterial pressure. One week after HW removal, blood gases, pH and HCO3- concentration remained unchanged in the mildly affected group. In the severely affected group, blood gas values were the same, but pH and HCO3- concentration improved slightly.     

Left ventricular repercussion of obesity-induced arterial hypertension in the dog

Obesity and hypertension are frequently associated. The aim of our study was to assess the effects of high fat diet on weight, blood pressure and left ventricule in dogs. We studied 6 male Beagle dogs before and after 7 weeks of hypercaloric hyperlipidic diet. Echocardiography was used to measure left ventricular wall thickness, volumes, ejection fraction and mass. Results are expressed as % of variation of initial values. After 20 weeks, dogs presented abdominal obesity with increased body weight (11.9 +/- 2.3 to 15.2 +/- 2 kg; p < 0.03) associated with an increasing of systolic (196.5 +/- 14.6 to 260.1 +/- 17.5 mmHg; p < 0.03), diastolic (76.6 +/- 9 to 110.6 +/- 10.2; p < 0.004) and mean blood pressure (128.8 +/- 7 to 152.7 +/- 7.6 mmHg; p < 0.004). There were non significant changes concerning diastolic thickness of septum and posterior wall. Left ventricular volumes increased in diastole (41.1 +/- 4.5 to 48.9 +/- 10.3 cm3; p < 0.03) and systole (12.2 +/- 1.7 to 14.9 +/- 3.2 cm3; p < 0.03). So, despite any changes in wall thickness, we observed an increased of ventricular mass (67 +/- 15 to 80 +/- 24.3 g; p < 0.03). Ejection fraction remained unchanged. CONCLUSION: it appears that hight fat diet induces obesity and hypertension in dogs; changes in left ventricule suggest a volodependent hypertension.     

Comparison of laparoscopic and minilap cholecystectomy for acute cholecystitis

The charts of all patients with acute cholecystitis undergoing either laparoscopic or minilap cholecystectomy at the Chinle Comprehensive Health Care Facility between October 1, 1991, and August 15, 1993, were retrospectively reviewed. During that period, 54 patients underwent laparoscopic cholecystectomy and 45 patients had minilap procedures. The two groups had similar mean age, sex distribution, temperature, leukocyte count, gallbladder wall thickness, and duration of preoperative symptoms. While laparoscopic cholecystectomy took an average of 16 min longer to perform than minilap cholecystectomy, patients who had laparoscopic cholecystectomy had less blood loss, reduced postoperative narcotic needs, and shorter hospital stays.     

The potential site of disordered gallbladder contractility during the early stage of cholesterol gallstone formation

BACKGROUND/AIMS: Feeding a high cholesterol diet to dogs causes a reduction in gallbladder smooth muscle contractility with a consequent stasis. Gallbladder stasis is an important link between the hepatic secretion of cholesterol saturated bile and the formation of cholesterol gallstones. METHODOLOGY: In this study we tried to localize the probable site of gallbladder smooth muscle dysfunction in a well established animal model of cholesterol gallstone disease. Adult male dogs were fed either a high or low cholesterol diet (control group). Strips of gallbladder smooth muscle for tension development were stimulated with two groups of agonists and dose response curves were plotted for all agonists used. RESULTS: The forces developed in response to the first group of agonists, the cell membrane-active agonists, e.g. acetylcholine, cholecystokinin, and potassium chloride were decreased in high cholesterol fed dogs with an increased cholesterol saturation of bile when compared to the control group. On the other hand, the contractile response showed non-significant differences between the test and the control group on using the second group of agonists that bypass the intact sarcolemmal membrane and stimulate directly either the contractile mechanism, e.g. barium, or the intracellular signal transduction pathways e.g. aluminum fluoride. CONCLUSION: We conclude that the smooth muscle defect responsible for disordered gallbladder contractility in high cholesterol fed dogs most probably involves the sarcolemmal membrane.