Analysis of specific serum markers of colon carcinoma using a Bhattacharyya-based support vector machine.

We aimed to evaluate the specificity of 12 tumor markers related to colon carcinoma and identify the most sensitive index. Bhattacharyya distance was used to evaluate the index. Then, different index combinations were used to establish a support vector machine (SVM) diagnosis model of malignant colon carcinoma. The accuracy of the model was checked. High accuracy was assumed to indicate the high specificity of the index. The Bhattacharyya distances of carcinoembryonic antigen, neuron-specific enolase, alpha-feto protein, and CA724 were the largest, and those of CYFRA21-І, CA125, and UGT1A83 were the second largest. The specificity of the combination of the above seven indexes was higher than that of other combinations, and the accuracy of the established SVM identification model was high. Using Bhattacharyya distance detection and establishing an SVM model based on different serum marker combinations can increase diagnostic accuracy, providing a theoretical basis for application of mathematical models in cancer diagnosis.

Genetic variability determinants of Helicobacter pylori: influence of clinical background and geographic origin of isolates.

Helicobacter pylori has an unusual pattern of genetic variation, which complicates research on this organism. To gain a better understanding of the forces behind this phenomenon, the extent to which recombination and single point mutations affect genetic variability in H. pylori was quantified and the influence of both geographical distance and clinical background were assessed. Site-directed restriction-endonuclease digestion of 2 gene fragments was performed on 168 isolates from Montreal and Berlin. Allelic diversity was found to be much higher for H. pylori than for other bacterial species. This finding is consistent with those of previous studies on H. pylori that were conducted using other techniques. However, nucleotide diversity was within the range reported for other bacterial species. Phylogenetic analysis found no grouping of strains with clinical background or geographical origin. Recombination at a rate that resulted in linkage equilibrium within genes can explain these observations.

[Inhibitory activity of Dianthus superbus L. and 11 kinds of diuretic Traditional Chinese medicines for urogenital Chlamydia trachomatis in vitro].

OBJECTIVE: To detect the susceptibility of urogenital chlamydia trachomatis(CT) to 12 kinds of diuretic traditional Chinese medicines. METHODS: The inhibitory activity of these medicines for CT was detected by microculture technique of McCoy cell in vitro. RESULTS: All the 12 kinds of diuretic traditional Chinese medicines had inhibitory activities for urogenital CT, with minimal inhibitory concentrations (MICs) from 0.122 mg.ml-1 to 62.5 mg.ml-1. The activities of Dianthus superbus L., Poria cocos(Shcw.) Woft, Polyporus umbellatus and Artemissia capillaris were stronger. The number and volume of CT inclusions reduced gradually and disappeared finally with the rise of concentration. CONCLUSION: All the 12 kinds of diuretic traditional Chinese medicines possess some inhibitory activity for urogenital CT.

Rapid detection of glycoprotein G gene for the diagnosis and typing of herpes simplex virus infection in genital herpes.

OBJECTIVE: To develop a new, rapid, and convenient technique for the diagnosis and typing of herpes simplex virus (HSV) in genital herpes (GH). METHODS: Using samples from skin vesicle fluid and urogenital mucosal swabs of subjects with GH, conventional polymerase chain reaction (PCR) (directed to polymerase gene: PCRpG) were compared with a newly developed PCR (directed to HSV glycoprotein gene: PCRgG). Both PCR methods were compared with virus isolation culture (VI) with indirect immunofluorescent staining (IIF). RESULTS: 80 samples from 40 GH patients (25 males) were tested. Positive results were seen in 52.5% (42/80) using PCRgG compared with 40% (32/80) by VI. Most of PCRgG positive samples (95.1%) were caused by HSV-2 infection. In samples from healing lesions, HSV was detected more often by PCRgG, than by VI. The results of typing by PCRgG and IIF were highly consistent. CONCLUSION: PCRgG is more sensitive than VI and PCRgG in detecting HSV in urogenital samples from subjects with GH. PCRgG is a convenient technique for the rapid detection and typing of GH.

Application of spheroid culture to human hepatocytes and maintenance of their differentiation.

Human hepatocytes cultured with a hormonally defined medium on non-adherent poly-(2-hydroxyethyl methacrylate)-coated surface were able to form spheroids. The maintenance of liver-specific functions was assessed by following secretion of albumin, transferrin and alpha 1-antitrypsin that were still detectable after 4 months of spheroidal culture. Moreover, cytochrome P-450 IA was induced by methylcholanthrene for up to 2 weeks. This cell system is very promising for long-term in vitro studies of human hepatocyte functions.

Long-term culture of adult rat hepatocyte spheroids.

Hepatocytes from adult rats were cultured on poly-HEMA-coated surface to form spheroids in hormonally defined media as previously shown with newborn rat hepatocytes. Spheroidal aggregates of adult rat hepatocytes were morphologically similar to those of newborn rat hepatocytes and could also form a monolayer of uniform liver parenchyma-like cells when transferred on collagen-coated surfaces even after 2 months of culture. Under these culture conditions, albumin and transferrin secreted in vitro by adult rat hepatocyte spheroids were detectable by immunoprecipitation method at least until 2 months of culture. The production of proteins by hepatocyte spheroids could be regulated in vitro by IL-6: the secretion of alpha 2-macroglobulin was increased and the secretion of albumin was decreased in the presence of this cytokine. In addition, cytochrome P450 IA1 was strongly induced by methylcholanthrene in adult rat hepatocyte spheroids, and the induction remained relatively constant up to 22 days of culture. These cells were also able to metabolize lidocaine to monoethylglycinexylidine when measured up to 14 days of culture, showing the presence of a relatively high level of P450 IIIA2. The UDP-glucuronyltransferase activity, specific for bilirubin conjugation, decreased to 18% of the initial value after 2 weeks of culture. This work showed that adult rat hepatocytes in long-term spheroid culture kept differentiated functions, providing a new model for the in vitro study of hepatocyte functions and complementing that of newborn rat hepatocytes using the same system.

Long-term culture of rat liver cell spheroids in hormonally defined media.

Liver cells of new-born rats, which were found to be able to form spheroidal aggregates when cultured on a nonadherent plastic substratum, were studied under various conditions of culture, mainly by adding different nutrients and growth factors to the culture medium. Analysis of hepatocyte-specific functions was carried out by immunoprecipitation to detect specific proteins newly secreted by liver cell spheroids on different days of culture. When no supplement was added to culture medium, the secretion of albumin and transferrin by liver cell spheroids was no longer detectable after 2 weeks of culture. When dexamethasone, glucagon, insulin, and EGF were added to culture medium, the secretion of albumin and transferrin remained detectable at least until 60 days of culture. This was even more striking when trace elements were added in addition to the three hormones and EGF. The effects of addition of these various factors to culture medium were also detectable with respect to alpha-FP secretion. Even after 54 days of culture in total supplemented medium, these liver cell spheroids could be transferred on a collagen-coated plastic substratum to form a monolayer of uniform liver parenchyma-like cells. The presence of extracellular matrix-like material was observed on the surface of cell spheroids. This could be responsible for attachment and fusion between cell spheroids. Thus, liver cell spheroids cultured in total supplemented medium ensured cell attachment to a biological matrix and cell-cell contact, which is thought to help maintain cell differentiation. Liver cell spheroids offer the possibility of toxicological and pharmacological studies as well as cultures in biomatrix and coculture systems. In addition these liver cells can be used for experiments in liver cell transplantation.

[Pancreatic fistula after left pancreatectomy. Frequency and severity]. / Fistules pancréatiques après pancréatectomie gauche. Fréquence et gravité.

In order to study the frequency and complications related to pancreatic fistula following distal pancreatectomy we have reviewed 19 patients operated on between January 1st 1981 and February 28 1986. There was no mortality but the incidence of pancreatic fistula was 52%. 40% of these cases developed a subphrenic abscess (21% of the total number of cases). These fistulas closed after an average post-operative period of 42 days. Reoperation for an infected collection was required in 4 cases. The incidence of pancreatic fistula was not related to the initial pancreatic pathology. Splenectomy did not influence the incidence of subphrenic abscess. Different techniques of closure of the distal pancreas after resection have not changed the incidence of this complication. The use of somatostatin appears to favourably influence the course of the fistula. These conclusions tend to confirm the results of other reported series.