Recognition of chemical compounds in contaminated water using time-dependent multiple dose cellular responses.

An early determination of toxicant compounds of water contaminations can gain critical time to protect citizens' health and save substantial amounts of medical costs. To determine toxins in real time, a multi-dose classification algorithm using cellular state variable identification (CSVID) is developed in this paper. First, the dynamic cytotoxicity response profiles of living cells are measured using a real-time cell electronic sensing (RT-CES) system. Changes in cell number expressed as cell index (CI) are recorded on-line as time series. Then CSVID, which reflects the cell killing, cell lysis and certain cellular pathological changes, is extracted from those dynamic cellular responses. Finally, a support vector machine (SVM) algorithm based on CSVID is employed to classify chemical compounds and determine their analogous cellular response pathway. In order to increase the classification accuracy, a majority vote of the class labels is also proposed. Several validation studies demonstrate that CSVID-based classification algorithm has great potential in distinguishing the cytotoxicity response of the cells in the presence of toxins.

Microelectronic-sensing assay to detect presence of Verotoxins in human faecal samples.

AIMS: To develop a novel Vero cell assay that implements a real-time cell electronic sensing (RT-CES) system for the determination of the presence of verotoxin-producing Escherichia coli (VTEC). The assay overcomes the major drawbacks in conventional Vero cell assay, for example, labour-intensive and time-consuming. METHODS AND RESULTS: Cells were grown onto the surfaces of microelectronic sensors that are integrated into the bottom surfaces of the microtiter plate. Cellular viability was monitored in real-time and quantified based on changes in the sensor's electrical impedance. For cell viability measurement, the data generated on the RT-CES system correlated well with those obtained by the Vero cell assay for Verotoxins. To assess cytotoxicity, test cells growing on microelectronic sensors were treated with either supernatant from pure cultures, or stool samples. The specific neutralizing antibodies of VT1 and VT2 were used to identify specific toxins in the samples. CONCLUSIONS: The RT-CES assay provides a sensitive measurement comparable to conventional crystal violet assay. The assay has been successfully and specifically used to identify VTEC in human faecal samples. SIGNIFICANCE AND IMPACT OF THE STUDY: The RT-CES assay significantly shortens the testing time from 48 to 72 h required by the crystal violet assay to only 15 h with automated operation.

Early determination of toxicant concentration in water supply using MHE.

In this paper, a novel application of state estimation in environmental engineering is presented. The objective is to use on-line estimation techniques including moving horizon estimator (MHE) and extended Kalman filer (EKF) for an early concentration estimation of toxic agent presented in water supply. These estimation techniques (MHE and EKF) can be integrated in an early warning system of several features including the ability of early detection and quantification of the presence of toxicants in the water supply system. The estimation is based on dynamic measurements generated by a real-time cell electronic sensor (RT-CES) and on existing cytotoxicity mathematical dynamic models.

Completeness and accuracy of the birth registry data on congenital anomalies in Alberta, Canada.

Vital statistics and other administrative data are becoming an increasingly important source for epidemiologic research and surveillance. This study, the first in Canada, evaluated the usefulness of birth registry data on congenital anomalies in Alberta. We compared the number of birth defects recorded in the birth registry with the number collected through the Alberta Congenital Anomalies Surveillance System (ACASS) between 1985 and 1996. In addition, records of 3,881 (99.9 %) babies with (a) birth defect(s) from the ACASS during 1994--1996 were matched to the birth registry by deterministic linkage. Of these, 2,969 babies had single anomalies that were used for validity analysis. The anomalies were grouped by those within International Classification of Disease (ICD) ICD-9 Section XIV (ICD-9=740.0-759.9) and those outside the Section XIV. For those within Section XIV, 24 summary diagnostic categories were examined. As shown, the total case count from the birth registry was on average about 3 % lower than that from the ACASS between 1985 and 1996. The validity of diagnostic categories is high for the 24 categories examined, with an overall agreement of between 80 % and 100 %. The sensitivity, positive predictive value, and kappa are also high for all these anomalies combined during 1994 and 1996, showing 95.7 %, 99.8, and 0.81 respectively.

Characteristics of PAHs, PCDD/Fs and PCBs in sediment following forest fires in northern Alberta.

Extensive forest fires occurred in northern Alberta, Canada, in 1998. Polynuclear aromatic hydrocarbons (PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) were studied following these forest fires in order to explore natural and anthropogenic influences on the affected forest fire area. Specifically, concentrations and profiles of these compounds were determined in sediment samples. A predominance of alkylated PAH derivatives over parent PAHs were observed at the burned and reference sites. Naturally dervied PAHs were abundant at all sites. A high proportion and concentration of retene was observed at the totally burned site and indicates some inputs from forest fires. Very low concentrations of PCDD/Fs and PCBs were observed at all sites, and the profiles were very similar. This likely reflects common atmospheric contributing sources to the study area.

Small bowel cancer in western Canada.

Based on incident cases of small intestinal cancers in the four western Canadian provinces reported in the population-based cancer registries of British Columbia, Alberta, Saskatchewan and Manitoba we evaluated the descriptive epidemiological characteristics such as age, sex and subsite distribution of adenocarcinomas, carcinoids, lymphomas and sarcomas for the period 1975-1989. The distribution of adenocarcinomas, carcinoids and lymphomas presented a clear trend along the length of the small bowel. Most of the adenocarcinomas (54.7%) occurred in the duodenum and their relative frequency decreased in aboral direction: 29.9% in the jejunum and 16.0% in the ileum. The carcinoids showed an opposite trend, an increasing relative frequency in aboral direction: 3.9% in the duodenum, 9.2% in the jejunum and 86.7% in the ileum. Lymphomas were more frequent in the ileum (49.5%) compared to jejunum (29.4%) and duodenum (21.0%). Most sarcomas occurred along the jejunum (46.7%). The mean and median ages of lymphoma and sarcoma patients were significantly lower compared to adenocarcinoma and carcinoid cases. There was no difference in mean and median age by gender in the adenocarcinoma and carcinoid categories, but in the lymphoma and sarcoma groups males were significantly younger than females.

Meta-analysis of progestin and estrogen receptors in human meningiomas.

Among 301 human meningiomas published in the literature, 69% were progestin receptor (PgR)-positive. Estrogen receptors (ER) were detected in only 13% of the samples. The PgR levels were also elevated (p < 0.001) compared to the ER concentration. No association with sex, age, menstrual status or tumor location was found. Meningiomas with typical histology (75/171), were PgR-positive in significantly greater proportion than the atypical (12/171) or transitional (27/171) tumors. The PgR levels in the typical meningiomas were also increased (p = 0.005) compared to the atypical or transitional meningiomas. The ER levels did not differ by histology. The association of PgR levels with different histologic types is not well documented in the literature. Such an association is important for the understanding of the natural history of this disease as well as in the design and evaluation of therapeutic trials.

Nonisotopic human papillomavirus DNA typing of cervical smears obtained at the initial colposcopic examination.

To determine the prevalence of human papillomavirus (HPV) infection in 401 patients attending colposcopy for the first time, scraped cervical cells were investigated using dot blot hybridization and biotinylated DNA probes to HPV 6 and 11 (low-risk types) and 16, 18, and 33 (high-risk types). The HPV DNA was isolated from 52% of patients (low-risk types = 4%, high-risk types = 48%). Seventy-five percent had a cervical intraepithelial neoplasia (CIN)-condyloma. Low-risk types were infrequent (7%) and high-risk types (41%) predominant in condyloma/CIN I lesions when converse rates were expected. As CIN I lesions harboring high-risk types are at some risk of progressing to a higher grade dysplasia, colposcopic examination and treatment of this subgroup would seem justified. As expected, high-risk types were statistically associated with increasing grades of dysplasia. This hybridization method identified typeable HPV DNA in 60% of patients with a CIN-condyloma, and highlighted a unique HPV profile for this patient cohort.

The pathogenesis of inflammatory polyps.

Eighty-six consecutive colonic resection specimens for inflammatory bowel disease were studied to determine the modes of inflammatory polyp formation. The two major groups of inflammatory polyps were polypoid mucosal tags due to undermining ulceration and mature inflammatory polyps composed of mucosa, muscularis mucosae, and a submucosal core. Mature inflammatory polyps were derived from polypoid mucosal tags after regeneration and the adjacent mucosa showed regenerative changes and submucosal scarring. The study confirms that ulceration which undermines the muscularis mucosae is the major precursor of inflammatory polyps.

Physical growth parameters of chinese children in calgary.

Though ethnic variation in growth is well recognized, little is known about the physical growth of Chinese Canadian children. The objectives of this study were to establish the growth parameters for Chinese Canadian children and to compare them with those of Caucasian Canadians. The authors measured height, weight and head circumference during periodic physical examinations of children who attended their clinic between 1980 and 1984. These children were residents of Calgary, Alberta. Children with congenital anomalies or acquired chronic diseases were excluded. A total of 2,149 children (946 ethnic Chinese and 1,203 Caucasians) were studied. Differences in growth characteristics of Chinese Canadian and Caucasian Canadian children were established. The data suggest that the use of normal growth charts derived from growth data on the North American population may not be appropriate for Chinese Canadians.