Cholesterol gallstones were produced in young male, golden Syrian hamsters, obtained from three different suppliers, by administering a nutritionally adequate, semipurified diet for periods of either 5 or 10 weeks. The major components of the lithogenic diet were casein, cornstarch, butterfat, corn oil and 0.3% cholesterol. The hamsters were obtained from Sesco, Harlan Sprague-Dawley (Engle hamster) and Charles River (Lakeview hamster). There were profound differences among the three groups with respect to gallstone formation and cholesterol metabolism: The highest incidence of gallstones occurred in Sesco hamsters, 44.4% and 63.6% after 5 and 10 weeks on the lithogenic diet, respectively. In the Engle hamster, after a 5-week feeding, cholesterol crystals and gallstones were absent. When the feeding period was extended to 10 weeks, cholesterol gallstones were present in 45.5% of the animals. In the Lakeview hamsters, neither gallstones nor cholesterol crystals were found in the gallbladder after a 5-week period. After 10 weeks, cholesterol gallstones were found in only a single hamster. In all groups, the lithogenic diet produced large increases of liver, serum and biliary cholesterol concentrations and increased liver weights. When the animals were fed for 5 weeks, only the bile of Sesco hamsters became supersaturated. Supersaturated bile was induced in all groups after a 10-week feeding of the lithogenic diet with cholesterol saturation ranging from 1.47 to 1.97. These data indicate that it is possible to induce cholesterol gallstones in hamsters by means of a nutritionally adequate, semipurified diet of moderate cholesterol content.(ABSTRACT TRUNCATED AT 250 WORDS)

Introducción El hematoma retroperitoneal espontáneo (HRE) corresponde a una colección hemática situada en cualquiera de los 3 compartimentos retroperitoneales: pararrenal anterior, perirrenal y pararrenal posterior. Se produce sin que exista traumatismo, manipulación endourológica o endovascular previa de los elementos del retroperitoneo (1). En la literatura no se han descrito diferencias entre el HRE y la hemorragia retroperitoneal espontánea, por lo que se las considerará sinónimos para fines de esta revisión. Es un cuadro clínico de difícil diagnóstico, que inicialmente puede ser oligo-sintomático (1) , sin embargo, su detección oportuna es fundamental, ya que el retraso diagnóstico determina una alta morbi-mortalidad. La etiología más frecuente de hematoma retrope-ritoneal espontáneo es la rotura de un aneurisma de la aorta abdominal. Otras causas de menor frecuencia son: hemorragias espontáneas de tumores renales o suprarrenales, otros tumores sólidos retroperitonea-les, terapia anticoagulante, discrasias sanguíneas y patología litiásica de la vía urinaria, entre otros (1,2). Además, se describe asociación con hipertensión arterial y arterioloesclerosis (3). La presentación clínica del HRE se caracteriza por masa abdominal palpable, dolor lumboabdominal, hipotensión y caída del hematocrito (1,3). Las caracterís-ticas e intensidad del dolor son variables y dependen, entre otros factores, de la localización y magnitud del hematoma. Se ha descrito irradiación del dolor hacia H e m a t o m a r e t r o p e r i t o n e a l d e c a u s a i n f r e c u e n t e : A propósito de un caso Abstract: The spontaneous retroperitoneal hematoma (SRH) is defined as a spontaneous hematic collection located in any of the retroperitoneal compartments. The most frequently encountered cause of retroperitoneal hemorrhage is a ruptured abdominal aortic aneurysm, followed by renal and adrenal tumors, along with some other less common causes. Performing accurate diagnosis of patients at admission has proven to be difficult, given that the clinical presentation is ample and variable and may mimic other pictures of abdominal or lower back pain. Imaging techniques, mainly angiography, computed tomography, and MR Imaging, represent a fundamental tool for both timely diagnosis and proper management of the condition. We report the case of a 56-year-old male patient with diagnosis of HIV, who presented with a history of abdominal pain and palpable abdominal mass. After a thorough imaging evaluation, patient was diagnosed with retroperitoneal hematoma, whose histological analysis revealed a Burkitt lymphoma.

Cholesterol gallstones were present in prairie dogs fed alfalfa plus corn with and without exogenous cholesterol (0.4%). The diets fed to the animals for eight weeks contained alfalfa plus corn in fixed proportions of 50:50, 85:15 and 15:85 (w/w). At sacrifice, all animals were healthy but had not gained weight; no deaths occurred during the experiment. Cholesterol gallstones were present in all groups. In the absence of exogenous cholesterol, the highest stone incidence was found in the animals which received the lowest fiber (highest corn) diets (alfalfa plus corn, 50:50, 67%; alfalfa plus corn, 15:85, 83%). Cholesterol gallstone incidence was 100% when exogenous cholesterol was added to the alfalfa plus corn diets (50:50 and 15:85). No pigment gallstones were detected in any animal. Liver and plasma cholesterol concentrations were highest in the animals receiving alfalfa plus corn (15:85) plus 0.4% cholesterol (4.29 mg/g, and 356 mg/dl, respectively). These values were lowest in animals receiving 85% alfalfa plus 15% corn without cholesterol (2.19 mg/g and 88 mg/dl, respectively). Lithogenic indices were below 1.00 in all groups. Biliary bile acids were mainly amidates of cholic acid and chenodeoxycholic acid, with the former predominating. Thus, gallstones can be formed in prairie dogs in the absence of exogenous cholesterol; gallstone incidence is reduced by dietary fiber.