[Residues of tetracycline and quinolones in wild fish living around a salmon aquaculture center in Chile]. / Residuos de tetraciclina y quinolonas en peces silvestres en una zona costera donde se desarrolla la acuicultura del salmón en Chile.

The presence of residues of tetracycline, quinolones and antiparasitic drugs was investigated in wild fish captured around salmon aquaculture pens in Cochamó, Region X, Chile. Residues of both antibiotics were found in the meta [corrected] of two species of wild fish that are consumed by humans, robalo (Elginops maclovinus) and cabrilla (Sebastes capensis) [corrected] These findings suggest that the antibiotic usage in salmon aquaculture in Chile has nvironmental implications that may affect human and animal health. More studies are needed in Chile to determine the relevance of these findings for human and animal health and the environment to regulate this use of antibiotics.

Residuos de tetraciclina y quinolonas en peces silvestres en una zona costera donde se desarrolla la acuicultura del salmón en Chile / Residues of tetracycline and quinolones in wild fish living around a salmon aquaculture center in Chile

La presencia de antibacterianos y antiparasitarios residuales fue investigada en muestras de carne de peces silvestres de consumo humano pescados alrededor de un recinto de acuicultura en Cochamó (41° 29' S; 72° 19'W), X Región, Chile. Esta investigación demostró que peces silvestres, incluyendo róbalo (Elginops maclovinus), cabrilla (Sebastes capensis) y truchas de vida libre (Oncorhynchus mykiss), ingieren alimento artificial para salmón y que la carne de algunos ejemplares de estos peces contienen tetracicilina y quinolona en cantidades detectables. Estos resultados sugieren que el uso de antibacterianos en la acuicultura del salmón, como ha sido demostrado en otros países, tiene efectos ambientales que se proyectan más allá de los recintos de acuicultura. Se indica que dada la relevancia de estos hallazgos para la salud humana y animal, el ambiente requerirá de estudios más amplios y detallados para implementar futuras regulaciones del uso de antibacterianos en acuicultura.

The presence of residues of tetracycline, quinolones and antiparasitic drugs was investigated in wild fish captured around salmon aquaculture pens in Cochamó, Region X, Chile. Residues of both antibiotics were found in the meta of two species of wild fish that are consumed by humans, robalo (Elginops maclovinus) and cabrilla (Sebastes capensis) . These findings suggest that the antibiotic usage in salmon aquaculture in Chile has environmental implications that may affect human and animal health. More studies are needed in Chile to determine the relevance of these findings for human and animal health and the environment to regulate this use of antibiotics.

Prognostic histomorphometry in colorectal adenocarcinoma.

In order to examine the use of morphometry in the prognosis of colorectal adenocarcinoma, histologic material from 30 patients was analyzed. The volume-weighted nuclear volume (Vvnuclei), mean nucleolar diameters (dnucleoli) and their standard deviation (snucleoli) were determined in each case. These variables were compared between patients who died of the disease and those who did not. Patients with disease-free survival had larger Vvnuclei than did those who died of their disease (P < .02). These data suggest that a neoplastic specimen from colorectal adenocarcinoma may contain quantifiable nuclear characteristics that may be prognostically useful.

Identification of Charcot-Leyden crystals by electron microscopy.

Observations of the ultrastructure of Charcot-Leyden crystals are sporadic in the literature. These crystals appear occasionally in clinical materials, however, and may pose diagnostic dilemmas if not correctly identified. Two cases in which unusual crystallike structures were seen on electron micrographs of specimens were evaluated for diagnostic purposes. These structures were tentatively identified as Charcot-Leyden crystals and subsequently were confirmed as such by immunoperoxidase labeling. The cases are reported together with a review of the ultrastructure, histology, immunology, and natural history of Charcot-Leyden crystals.

Nucleolar prominence as a diagnostic variable in prostatic carcinoma.

The diagnosis of well-differentiated adenocarcinoma of the prostate can be difficult on needle biopsy specimens. Nucleolar prominence has proven to be a useful diagnostic variable, but its objective evaluation has had limited study. To find nucleolar criteria that might differentiate benign from malignant conditions, we examined 41 open prostatectomy specimens, 25 of which were removed for well-differentiated adenocarcinoma and 16 of which were removed for benign prostatic hypertrophy (BPH). Four acini of carcinoma, prostatic intraepithelial neoplasia (PIN), atypical adenomatous hyperplasia (AAH), nodular hyperplasia, and normal tissue were examined. The total number of nuclei with nucleoli 3 microns or greater (N'), the fraction of nuclei with nucleoli 3 microns or greater (N'/N), and the average diameters of nucleoli 3 microns or greater (AVG) were recorded. Hyperplastic and normal areas, when compared with carcinoma, had significantly smaller N',N'/N, and AVG values (P less than 0.005). The N' and N'/N values were significantly higher in hyperplasia when compared with normal acini (P less than 0.005). In addition, N' and N'/N values in PIN were significantly greater than those in AAH (P less than 0.0001). In comparing prostates with and without carcinoma, N' and N'/N were significantly different for hyperplastic areas. In only two cancer areas and one PIN area was the N'/N ratio less than 0.31, which was the highest value for either hyperplastic or normal areas. Although AVG also were significantly different, they did not improve discrimination between the groups. We conclude that N'/N ratios are useful in diagnosing well-differentiated prostatic adenocarcinoma on small tissue samples.

Effects of hypercalcemia-producing tumor extract and parathyroid hormone on osteoclast ultrastructure.

Hypercalcemia is a frequent complication of cancer. Recently, parathyroid hormone-related protein has been isolated from tumors associated with this syndrome. In the present study, the effects of tumor-derived hypercalcemic factor and bovine parathyroid hormone (PTH) on bone were compared in an organ culture system using calvarial bones from newborn mice. Mouse calvaria were incubated for 72 h with control medium or media containing 0.15 mg/m tumor extract (TE) or 2 x 10(-9) M PTH. Bone resorption, as assessed by the amount of calcium released into the medium and the number of osteoclasts counted on light microscopy, was increased by both PTH and TE. On electron microscopy, areas for cytoplasm, ruffled border and clear zone were statistically increased in PTH- and TE-treated calvaria as compared to control. These values were not significantly different between PTH- and TE-treated calvaria. The study therefore demonstrates that the ultrastructural changes in osteoclasts induced by the hypercalcemia-producing TE are similar to those induced by PTH.

Comparison of intralobar non-parenchyma, subcapsular non-parenchyma, and liver capsule thickness.

The intralobar and subcapsular areas of human liver were compared in terms of morphometry and morphology, and a correlation was made between the thickness of liver capsules and the amount of intralobar non-parenchyma in normal and diseased livers. Tissue was systematically sampled from 16 normal and 26 fibrotic livers taken at necropsy. The volume fraction of subcapsular and intralobar non-parenchyma and the capsule thickness were determined by morphometry on histological sections. The volume fraction of intralobar non-parenchyma not only correlated well (tau = 0.7, p less than 0.001) with but was also equivalent in each case to the actual volume fraction of subcapsular non-parenchyma. Morphologically, the intralobar and subcapsular areas were remarkably similar. The volume fraction of intralobar non-parenchyma also correlated well (tau = 0.5, p less than 0.001) with capsule thickness. These results show that pathological changes in liver architecture were essentially similar in the intralobar and subcapsular areas and that capsule thickness reflected intralobar non-parenchymal changes.

Morphometry of liver parenchyma in needle biopsy specimens from patients with alcoholic liver disease: preliminary variables for the diagnosis and prognosis of cirrhosis.

The diagnosis of liver cirrhosis depends on assessing fibrosis and architectural alterations of the liver. In a needle biopsy specimen the connective tissue is often inadequately sampled, which leads to an uncertain diagnosis. Parenchymal features alone are currently insufficient. We, therefore, carried out a comprehensive morphometric study to detect parenchymal structures that may be useful in the diagnosis and prognosis of cirrhosis. Five human liver biopsy specimens were selected from each of four alcoholic disease groups: fatty liver, alcoholic hepatitis, cirrhosis with greater-than-5-yr survival, and cirrhosis with less-than-2-yr survival. Volume fractions (Vv) and surface densities (Sv) were determined stereologically for parenchymal and hepatocellular compartments in electron micrographs. The differences between noncirrhosis and cirrhosis were (a) a doubling of the Vv of parenchymal interstitial space, (b) a nearly 25% increase in the Sv of hepatocyte plasma membrane, (c) a nearly 50% increase in the Sv of hepatocyte RER, and (d) a decrease in the Sv of the outer mitochondrial membrane. The significant difference between the greater than 5-yr and the less than 2-yr survivors of cirrhosis was the marked decrease in hepatocyte nuclear Vv in the latter group. Statistical analysis of our data showed that optimal sampling is achieved with as few as three micrographs from one block of tissue per biopsy specimen.

Hepatic structural correlates of liver fibrosis: a morphometric analysis.

Liver fibrosis is an important feature of many liver diseases, and the assessment of fibrosis is essential for diagnosis and prognosis. Liver needle biopsy, however, tends to sample preferentially the soft parenchyma, which poorly reflects the true extent of fibrosis. Therefore, we have searched for capsule and parenchymal features that are correlated with the fibrosis. To test for these correlations, we used a morphometric analysis of a rat model of liver fibrosis. We demonstrated that, of the variables examined, capsule thickness was the best correlate of liver fibrosis. Our results also showed that there were parenchymal structures that underwent changes that were well-correlated with the development of fibrosis in the liver. These changes were identified as increases in hepatocyte nucleus, cytoplasm, and mitochondria. These facts suggest that, at least in a rat model of fibrosis, capsule thickness is a useful parameter by which to assess liver fibrosis and that specific and apparently adaptive parenchymal changes are well-correlated to fibrosis.

Transluminal expandable nitinol coil stent grafting: preliminary report.

A method is described for the percutaneous catheter placement of expandable nitinol coil stents for the nonoperative restoration and maintenance of patency in internal flow pathways, especially the lumina of blood vessels and biliary ducts.

A morphometric analysis of the hypertrophy of experimental liver cirrhosis.

The objective of this study was to better elucidate the composition of the hypertrophic cirrhotic liver. We induced cirrhosis with hypertrophy in rats by simultaneous treatment with CCl4 and phenobarbital (PB) and devised a hierarchy of structure applicable to the sampling and morphometric analysis of untreated and PB-treated control livers and of cirrhotic livers. Our analysis demonstrated that the hepatomegaly attributable to cirrhosis is virtually the total result of an increase in the specific volume (ml/100 g body weight) of the non-parenchyma, most of which is connective tissue and vascular lumen volume. Inconsequential to the hepatomegaly but statistically significant were the volumetric increases found in the following parenchymal compartments: hepatocyte nucleus, Kupffer/endothelial cell nucleus, Ito cell nucleus and cytoplasm, and bile canaliculus. The change in the hepatocyte nucleus is the result of an increase in size rather than in number. Sinusoidal space is the only compartment that showed a significant decrease. This study shows the practicality and usefulness of applying morphometric methods to cirrhotic liver.

Morphometry of the small intestinal enterocytes of the fasted rat and the effects of colchicine.

The function of the microtubules that are present in the villus enterocytes of the mammalian small intestine is virtually unknown. In order to advance our knowledge about enterocyte microtubules, a quantitative ultrastructural comparison was carried out on enterocytes from rats injected intraperitoneally with colchicine (0.5 mg/100 g body weight) in saline and from rats injected with saline alone. Our morphometric and stereologic study demonstrates that colchicine treatment results in 1) an absolute decrease in microtubules, 2) a reduction in microvilli, essentially in length, 3) an increased thickness of the terminal web, 4) an increase in total lysosomal volume, apparently by an increased number of smaller lysosomes, and 5) a decrease in the number of Golgi lamellae. These results along with those from other studies suggest to us that enterocyte microtubules are involved in the biogenesis of microvillus plasma membrane. Our morphometric data from the saline-treated rats essentially agree with comparable data from other studies. However, comparison with comparable data from hamster enterocytes demonstrates species differences.

Electron microscopic identity of talc in the liver of a narcotic addict.

In this report we identify the ultrastructural correlate of birefringent crystals that we found in biopsy specimens from an intravenous drug addict and that were presumed to be talc. By electron microscopy the crystals were electron dense and elongated with sharp edges and had an apparent lamination. The crystals were found within portal or granuloma macrophages and were often displaced or associated with section tears and knife marks. Weak electron diffraction patterns were obtained that were consistent with talc.

Cholangiocarcinomas induced by feeding 3'-methyl-4-dimethylaminoazobenzene to rats. Histopathology and ultrastructure.

Thirty-three male Sprague-Dawley rats were fed a carcinogenic (0.064% 3'-methyl-4-dimethylaminoazobenzene, 3'-Me-DAB) ground meal normal diet. After 12 weeks the ground meal diet was replaced with a normal pellet diet, and the 30 surviving animals were divided into three equal groups. One group was sacrificed at the twelfth week and the other groups 4 and 8 weeks later. Control animals were also run. Based on previous studies which used "tumor-promoting" diets and 3'-Me-DAB, we expected a less than 100% incidence of predominantly hepatocellular carcinomas. However, we found mucin-producing cholangiocarcinomas in all 30 animals and, in addition, a small hepatocellular component in 3 of the animals. By electron microscopy the intestinal mucosal features of microvillous border cells, goblet cells, and endocrine-like cells were found. We suggest that the tumors produced as described here provide a good animal model of mucin-producing cholangiocarcinomas.