Diabetes screening of children in a remote First Nations community on the west coast of Canada: challenges and solutions.

Type 2 diabetes (T2D) and its precursor, impaired glucose tolerance (IGT), are now reaching epidemic proportions among Aboriginal Canadians. Of particular concern is the appearance and increasing prevalence of T2D and IGT among Aboriginal youth. At the request of three communities in the Tsimshian nation on the northern coast of British Columbia (with which the Department of Pediatrics, University of British Columbia, had a pre-existing partnership) a screening program was undertaken to determine the prevalence of T2D and IGT among the children. The long-term goal was the collaborative development of intervention programs for each community. The challenges of meeting this request included the sociological and ethical issues associated with research in First Nations communities, as well as the pragmatic issues of conducting complex research in remote communities. Three separate visits were undertaken to respect the cultural dynamics and capacity of the community to accommodate a project of this magnitude. The process began with dialogue, listening and presentations to the community. Only then began the planning of logistics and application for funding. Next, the team visited the communities to ensure understanding of exactly what was involved for the community, each child and family, and to be certain that consent was fully informed. For the diabetes screening visit, special arrangements including chartering a Beaver float plane were needed for the transport of the five-member team with all the necessary equipment, including a -20(o)C freezer to safeguard the integrity of blood samples. The 100% consent rate, successful conduct of study, and retention of community support achieved by the process, indicate that population-based clinical research is possible in remote First Nations communities. This is best achieved with appropriate dialogue, care, respect and planning to overcome the sociological, ethical and practical challenges.

Correlation of transcutaneous hepatic near-infrared spectroscopy readings with liver surface readings and perfusion parameters in a piglet endotoxemic shock model.

PURPOSE: To determine whether transcutaneous liver near-infrared spectrophotometry (NIRS) measurements correlate with NIRS measurements taken directly from the liver surface, and invasive blood flow measurements. PROCEDURE: Laparotomy was performed in 12 Yorkshire piglets, and ultrasound blood flow probes were placed on the hepatic artery and portal vein. Intravascular catheters were inserted into the hepatic and portal veins for intermittent blood sampling, and a pulmonary artery catheter was inserted via the jugular vein for cardiac output measurements. NIRS optodes were placed on skin overlying the liver and directly across the right hepatic lobe. Endotoxemic shock was induced by continuous infusion of Escherichia coli lipopolysaccharide O55:B5. Pearson's correlations were calculated between the NIRS readings and the perfusion parameters. FINDINGS: After endotoxemic shock induction, liver blood flow, and oxygen delivery decreased significantly. There were statistically significant correlations between the transcutaneous and liver-surface NIRS readings for oxyhemoglobin, deoxyhemoglobin, and cytochrome c oxidase concentrations. There were similar significant correlations of the transcutaneous oxyhemoglobin with both the mixed venous and hepatic vein saturation, and mixed venous and hepatic vein lactate. CONCLUSIONS: Transcutaneous NIRS readings of the liver, in an endotoxemic shock model, correlate with NIRS readings taking directly from the liver surface, as well as with global and specific organ-perfusion parameters.

An inventory of Canadian anesthesiology. Human research from 1995 through 1999.

PURPOSE: The year 2000 provides a symbolic opportunity to assess the past initiatives in anesthesia research. As in many other fields, medical research has benefited from utilizing computerized data bases to facilitate enumerating areas of interest. We have created a baseline survey of past research in the fields of anesthesia, anesthetics, analgesia, and analgesics to highlight Canadian studies. METHODS: The survey was undertaken using the Medical Literature Analysis and Retrieval System (MEDLARS) medical literature archive for the years 1995 through 1999. The principal categories and sub-categories of MEDLARS' anesthesia classifications were counted for 70 countries contributing to the archive. RESULTS: Canadian contributions ranged from 141 (1992) to 185 (1999) and represented annually 3% of the world total in the anesthesia categories. The greatest number of studies (30-38%) were about adults aged 19 to 44 yr, and there were between 4% and 14% more studies of females than males. "Pharmacology" and "therapeutic use" were the most frequent topics, lidocaine, fentanyl, and propofol were the most studied anesthetics, and non-steroidal anti-inflammatories, opium, morphine, and fentanyl were the most studied analgesics. Among the types of studies, those classified as "quality of health care" occurred most frequently (16%). Canadian trends closely follow world trends. CONCLUSION: The collected counts provide a comprehensive overview of research trends for the past five years.

A quantitative ranking of Canada's research output of original human studies for the decade 1989 to 1998.

BACKGROUND: Since 1987 research articles have been catalogued with the author's affiliation address in the 40 databases of the Medical Literature Analysis and Retrieval System (MEDLARS) of the National Library of Medicine, Bethesda, Md. The present study was conducted to examine the Canadian entries in MEDLARS to interpret past and future trends and to combine the MEDLARS demographic data with data from other sources to rank Canadian research output of human studies both nationally and internationally. METHODS: The PubMed Web site of the National Library of Medicine was used to count medical articles archived in MEDLARS and published from Jan. 1, 1989, through Dec. 31, 1998. The articles attributed to Canadian authors were compared by country, province, city, medical school, hospital, article type, journal and medical specialty. RESULTS: During the study period Canadian authors contributed on average 3% (standard deviation [SD] 0.2%) of the worldwide MEDLARS content each year, which translated to a mean of 11,067 (SD 1037) articles per year; 49% were human studies, of which 13% were clinical or controlled trials, and 55% involved people aged 18 years or less. In total, 68% of the articles were by authors affiliated with Canadian medical schools; those affiliated with the University of Toronto accounted for the greatest number (8604), whereas authors affiliated with McGill University had the greatest rate of annual increase in the quantity published (8%). Over one-third (38%) of the articles appeared in Canadian journals. When counted by specialty, 17% of the articles were by authors with clinical specialties, 5% by those with surgical specialties and 3% by those with laboratory specialties. INTERPRETATION: The annual rate of increase in research output for Canada was more than 3 times higher than that seen world wide. Canada is now ranked seventh among countries contributing human studies to MEDLARS. The increase indicates that Canada's medical schools are productive, competitive in making contributions to medical science and are supporting Canadian journals.

Variations in regional cerebral blood volume in neonates associated with nursery care events.

This pilot study investigated the frequency of events that cause cerebral oxygenation disturbances in ventilator-dependant neonates in the neonatal intensive care unit. Continuous, noninvasive, near infrared spectrophotometry measurements (changes in oxy and deoxy hemoglobin concentration, and cytochrome C oxidase redox status) were made at half-second intervals on 10 ventilator-dependent neonates (30.5 weeks average corrected gestation age, 1051 g average weight) and annotated to nursery events at the bedside. Examples of disturbances affecting cerebral oxygenation were opening incubator doors, handling, heel stabs, conversation, blanket tucking, and steno-paging. These events produced 7-40% changes in blood volume for durations of 5-60 sec, and occurred at a rate of up to 45 events within a 2 hr period. Spectrometry detected 63% more events than were observed and documented clinically. Noninvasive monitoring of cerebral oxygenation status could give new insight into managing the high-risk infant environment.

Unresolved instrumentation problems following clinical trials using near infrared spectroscopy.

Near infrared spectroscopy (NIRS) clinical trials conducted over a seven year period have identified instrument engineering problems related to fiber optic failure, electromagnetic interference, chromophore algorithms, and computational software. These problems have caused confusion amongst clinicians at the bedside, rejection of large volumes of data, repeated reanalysis of data, and a significant diversion of project resources away from clinical studies and into engineering solutions. This article summarizes previously published studies and presents new data which, together, emphasize the need for improvements in NIRS technology. Instrument designers need to be aware of the need for these improvements if NIRS is to serve clinicians better during research designed to rationally define clinical management protocols. © 1998 Society of Photo-Optical Instrumentation Engineers.

Comparison of 13 published cytochrome c oxidase near-infrared spectroscopy algorithms.

Conflicting patterns of change in cytochrome c oxidase (Cyt a,a3) redox status have been obtained between different near-infrared spectrophotometers when making measurements during tissue ischaemia. This study identifies possible sources of error that could be the cause of the discrepancy. A single set of optical density data was repeatedly analysed using each of the absorption spectra from 13 publications. In addition, changes in Cyt a,a3 redox status were calculated from the data set using three numerical methods, five computer software routines, eight displacements in wavelength, and ten incremental changes in the value of absorption or concentration coefficients. All Cyt a,a3 absorption spectra resulted in algorithms yielding similar patterns of change, regardless of the numerical method or computer process employed (0.9996 average r2, coefficient of correlation). However, a significantly different pattern of change in Cyt a,a3 redox status, resembling that reported by Piantadosi [Piantadosi CA (1993) Methods Toxicol. 2:107-126], was obtained when either the wavelengths, and/or the absorption values were altered to simulate erroneous values. This implies that all of the present algorithms are valid (including those of Piantadosi), but that microchip encoding errors may exist in the instrument used by Piantadosi.

Determination of the refractive index of liquid carbon monoxide.

The refractive index of liquid carbon monoxide at 78.3 +/- 0.5 K was measured by means of a relatively simple interferometric technique. The values obtained were n = 1.2122 for lambda = 632.8 nm and n = 1.2213 for lambda = 514.5 nm with 0.2% uncertainty.