Determination of abamectin residues in fruits and vegetables by high-performance liquid chromatography.

A rapid and sensitive HPLC method has been developed and validated for the determination of abamectin residues (avermectin B1a and B1b, as well as the metabolite 8,9-Z-avermectin B1) in apples, pears and tomatoes. Residues are extracted with acetonitrile. The diluted extract is cleaned up on a C18 solid-phase extraction cartridge. Abamectin residues are derivatised with trifluoroacetic acid and 1-methylimidazole and determined by reversed-phase liquid chromatography with fluorescence detection (excitation: 365 nm and emission: 470 nm). High and consistent recoveries, ranging from 88 to 106%, were obtained, at spiking levels of 10, 20 and 50 micrograms/kg, when analysing apples, pears and tomatoes.

Endoscopic noninvasive manometry of esophageal varices: prognostic significance.

Our study attempts to establish a relation between the pressure in the esophageal varices and the clinical outcome in 18 patients in whom sclerotherapy for bleeding esophageal varices was performed. The measured pressure was compared to the endoscopic findings. Before sclerotherapy, a noninvasive manometric measurement was performed on the varices using a spheric membrane manometer fixed at the tip of an endoscope. Twelve of our 18 patients suffered repeated hemorrhage which led to death in five. We discovered a relation between the measured pressure and the outcome. Beside this, we measured the highest pressures in the largest varices. The relation that seems to exist between the pressure in the esophageal varices, the endoscopic findings, and the severity of the portal hypertension may provide new opportunities for research in this field.

Crystals occurring in pulmonary cytology specimens. Association with Aspergillus infection.

Birefringent needlelike crystals in rosette or wheat-sheaf-like arrangements were found in pulmonary cytology specimens from 11 of 65 patients who had either sputum cultures positive for Aspergillus or histologically confirmed pulmonary aspergilloma. No crystals were found in specimens from 60 control patients with and without known fungal disease. The crystals were most often associated with A. niger infection (45.4%), followed by A. flavus (16%). Crystals were also observed in one case of A. fumigatus infection and in one case in which the species was not determined. In two cases, crystals were found more than one year before sputum cultures became positive; in one of these patients, a fungus ball was not identified by X ray until five years after the first appearance of the crystals in the sputum. Sixty-four percent of the patients with crystals also showed moderate to severe cytologic atypia. The crystals are thought to be calcium oxalate. We conclude that the presence of birefringent needlelike crystals with rosette or wheat-sheaf-like arrangements in pulmonary cytology specimens is a reliable marker for the presence of Aspergillus infection, which may be detected before cultures are positive or a fungus ball is evident on X ray.

Superinfected actinomycotic abscess of the liver.

Isolated actinomycotic liver abscess is rare. We report a case with fulminant evolution, which was treated successfully with surgery and penicillin. In human actinomycosis, Actinomyces israeli is the main infective agent. An abdominal localisation is uncommon, occurring in less than 25% of cases. Isolated liver lesions are extremely rare; their presence might be interpreted as the result of the hematogenous spread of a no longer present intestinal lesion. The evolution of actinomycosis is usually torpid. In the present case, mixed infection with Fusobacterium nucleatum might explain the acute evolution.

Chronic pancreatic pleural effusions and ascites.

The occurrence of pleural effusion or ascites, secondary to internal pancreatic fistula, is a rare clinical syndrome and diagnosis is, therefore, often missed. The fluid accumulation has been attributed to disruption of the pancreatic duct or to rupture of a pseudocyst. In a 20 year period, 106 patients were hospitalized in the department of surgery, CHUV, with a diagnosis of chronic or chronic relapsing pancreatitis, and 77 with that of pancreatic pseudocyst. During this time, five patients with chronic pancreatic and pleural or peritoneal effusions have been observed. These five cases present a good pattern of the possible causes and evolution of the disease. Wirsungography is of great value for the surgical management of these patients, allowing the right technique to be chosen for each particular case. Surgery caused disappearance of the effusions in our five patients.

The gastric mucosa in experimental duodenogastric reflux. A scanning electron microscope study.

In the course of a long-lasting experiment on entero-gastric reflux in the dog, we examined with the SEM the gastric mucosal surface epithelium in 22 animals chronically exposed to any type of enteral diversion to the stomach, associated in one group to a highly selective vagotomy. Tissue samples were collected at the time of corrective surgery and at sacrifice in the survivors. The control group was composed of 4 dogs with Roux-en-Y loops. At remedial surgery, about half the dogs failed to display any cellular alteration, regardless of the group they belonged to. The isolated biliary reflux group alone showed fundic erosions in 100% of the dogs. In the antral area, the isolated pancreatic reflux appeared to be the most damaging. Similar erosions were found in the antrum and the fundus of the majority of control dogs. Six to twelve months after suppression of the reflux, the erosions showed a tendency to incomplete regression, and more often to progression. We advocate the protective role of the chronic alkaline reflux on the gastric mucosa to explain our results.

A long-term study of experimental duodenogastric reflux on the vagotomized stomach in dogs.

The possibility has been explored in dogs that the effects of chronic enteral reflux on the gastric mucosa may be modified by highly selective vagotomy (HSV). In both the innervated and the vagotomized stomachs, Roux-en-Y duodenogastrostomy induced mucosal hyperaemia and foveolar hyperplasia; the mucosa regained normal morphology after the elimination of reflux. Duodenogastrostomy without HSV did not influence basal serum gastrin but resulted in a significant increase in mucosal histamine. After duodenogastrostomy with HSV basal serum gastrin decreased significantly and mucosal histamine was not affected. It is concluded that foveolar hyperplasia is a reversible reaction of the mucosa to potentially damaging agents like enteral contents. It is also suggested that the combination of chronic enterogastric reflux, abnormal gastrointestinal motility and HSV might have an inhibitory effect on gastrin release.

Modifications of the gastric mucosal barrier induced by experimental duodenogastric reflux: an electron microscopy study.

The present study was undertaken to examine the ultrastructure of antral foveolar epithelium of dogs submitted to long term duodenogastric reflux. Minimal ultrastructural alterations (swelling of the cellular organelles, shortening of the microvilli, irregularity of the secretory granules) were observed. Total necrosis of isolated cells was rare. The lesions appeared in all dogs including the controls, and were not always reversed by the elimination of reflux. The significance of these findings is not clear and is probably not dependent on continuous exposure to duodenogastric reflux.

A long-term study of different types of experimental alkaline reflux and the effects of its suppression in dogs.

The gastric mucosa of 19 mongrel dogs was submitted to a bilio-pancreatic, isolated biliary or isolated pancreatic reflux. With an isolated biliary reflux, there is a more rapid and more severe hyperaemia and foveolar hyperplasia of the mucosa of the fundus than with an isolated pancreatic reflux. There was no significant change in the basal serum level of gastrin with any of these different types of alkaline reflux, but we observed a statistically significant increase in the level of histamine in the gastric mucosa. Hyperaemia and foveolar hyperplasia of the fundic mucosa both disappeared when the alkaline reflux was suppressed, and there was a statistically significant decrease in the basal serum level of gastrin and in the level of histamine in the gastric mucosa.

Simplified extraction and cleanup for multiresidue determination of pesticides in lanolin.

In the proposed method, a light petroleum solution of lanolin (wool fat) is adsorbed on diatomaceous earth in an Extrelut column, and the pesticides are eluted with acetonitrile saturated with light petroleum. After evaporation to a small volume, the extract is subjected to solid-phase extraction (SPE) on a C-18 column. The acetonitrile eluate is evaporated to dryness and the residue is taken up in light petroleum. Organophosphorus pesticides are determined by temperature-programmed gas chromatography (GC) on a wide-bore column using a flame photometric detector in the phosphorus mode. Organochlorine pesticides are determined after miniaturized Florisil cleanup by classic GC on an OV-17/QF-1 packed column, using an electron capture detector. This procedure is more rapid and straightforward than the time-consuming AOAC extraction method, 29.014. Cleanup was better and the results obtained were comparable. Recoveries for 13 organochlorine and organophosphorus pesticides, frequently found in lanolin, ranged from 80 to 90%.

[Gallbladder duplication and accessory gallbladders]. / Duplication vésiculaire et vésicules accessoires.

Double gallbladders represent a large spectrum of malformations; on an embryological base these anomalies are divided into true duplications and accessory gallbladders according to whether both cystic ducts are fused or separated to join the common bile duct. The authors have observed four cases one of which is discussed for diagnostic and therapeutic considerations.

[4 cases of potassium enteropathy]. / A propos de quatre cas d'entéropathie potassique.

The oral use of enteric-coated potassium chloride (and apparently of its slow-release form too) to compensate potassium loss during thiazide diuretic treatment may engender ischemic enteropathy. This iatrogenic condition is linked to the vaso-active properties of KCl, which act on blood vessels often damaged by hypertension or chronic heart failure. Four observations are presented involving stenosing ulceration or perforation of the small bowel following oral KCl treatment. The main clinical, pathological and therapeutic aspects are discussed.