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Biomedical subjects

M Adrian

Publications and source records attributed to M Adrian.

At least 37 records · Page 2Linked to original sources
PubMed1996

Does allowing the sale of wine in Quebec grocery stores increase consumption?

OBJECTIVE: To determine if allowing wine sales in corner grocery stores, beginning in 1978 for domestic Quebec wines and then in 1983 for imported wines, in addition to sales in government monopoly stores, led to an increase in alcohol consumption. METHOD: Aggregate retail sales data for the period 1953 to 1990 were analyzed using econometric regression techniques. Time series (unit root) analysis and structural modeling were used to take into account the effect of price, income and other social, economic and demographic factors in order to determine the effect of factors underlying consumption behavior in both the long and short term. RESULTS: In the post-intervention period, wine consumption continued along the rising trend established in the pre-intervention period, with an apparent shift in favor of domestic wine consumption. The increase in wine consumption was highest in the period immediately following privatization, but the increase eventually dampened down within a few years. There was no fundamental change in the responsiveness of wine consumption to price. CONCLUSION: Our findings suggest that the level of wine consumption can be controlled through price changes when alcohol availability increases through increased sales outlets.

Adolescent↗
PubMed1995

Temporal coupling between external auditory information and the phases of walking.

The purpose of this study was to investigate the effects of an imposed external auditory constraint upon the temporal organization of walking. Ten subjects were videotaped walking normally (N) and with instructions to couple naturally, at mid-swing, or at toe-off to a metronome beat. Based upon an analysis of variance and post hoc Scheffé tests most temporal variables were not significantly different among conditions. The duration of swing phase was significantly different between natural coupling and toe-off. The deviation from the metronome beat was significantly different between the natural coupling and both mid-swing and toe-off. Subjects generally were not successful in achieving coupling during the latter conditions. Thigh and shank phase portraits were used to describe the system's organization to the external constraint.

Acoustic Stimulation↗
PubMed1995

Substance use as a measure of social integration for women of different ethnocultural groups into mainstream culture in a pluralist society: the example of Canada.

Analysis of Canadian data from the 1989 National Alcohol and Drugs Survey was used to identify profiles of alcohol and other drug-using behaviors among Canadian women of different ethnic or cultural groups. The profile considered 110 different substance use variables including alcohol or drug type used, quantity, frequency, drinking or drug-taking circumstances, beverage preference, reasons for drinking or not drinking, and opinions regarding appropriate drinking or drug-taking behavior of Canadian women who described themselves as belonging to the "Canadian," French, English, German/Dutch, Irish, Scottish, Ukrainian/Polish, Italian/Portuguese, and "Other" (Chinese, Jewish, and "Other") ethnic or cultural groups. Alcohol, tobacco, and drug use behavior was found to differ by ethnocultural group. Further, each ethnocultural group was found to differ from the national average. The amount of difference between the national average and each ethnocultural group was related to the period of arrival and the length of time that an ethnocultural group has been present in Canada. The degree of similarity or difference between each ethnocultural group and the mainstream national average for alcohol, tobacco, and drug use and drug-use behavior may be used to measure the degree of social integration of each ethnocultural group and the degree of acculturation of women of specific ethnocultural groups into mainstream Canadian society.

Acculturation↗
PubMed1994

Structure of intracellular mature vaccinia virus observed by cryoelectron microscopy.

Intracellular mature vaccinia virus, also called intracellular naked virus, and its core envelope have been observed in their native, unfixed, unstained, hydrated states by cryoelectron microscopy of vitrified samples. The virion appears as a smooth rounded rectangle of ca. 350 by 270 nm. The core seems homogeneous and is surrounded by a 30-nm-thick surface domain delimited by membranes. We show that surface tubules and most likely also the characteristic dumbbell-shaped core with the lateral bodies which are generally observed in negatively stained or conventionally embedded samples are preparation artifacts.

Cryoultramicrotomy↗
PubMed1994

Community-based facilities may be replacing hospitals for the treatment of alcoholism: the evidence from Ontario.

We examined hospital utilization and use of community facilities for the treatment of alcohol problems in Ontario using Statistics Canada, Hospital Medical Records Institute records, and other administrative records. Between 1974 and 1986 there was a large drop in utilization of hospital services for treatment of alcohol problems. Rates of alcohol inpatient cases in general hospitals dropped by 47% and in mental hospitals by 33%. At the same time, there was an increase in overall availability of hospital beds and bed-days of care for all medical conditions, and no change in the total number of hospital discharges (1.3 million) and occupancy rates (80-85%). Also at the same time, the number of community-based programs for the treatment of alcohol problems increased, as did the number of persons or cases treated by them. This was associated with a drop of inpatient cases treated for alcohol problems in 38 out of 48 counties in Ontario (P < .0005). Multiple regression techniques were used to take into account the effect of the slight decline in overall alcohol consumption in this period. We found that after controlling for changes in alcohol consumption, the addition of one community-based alcohol treatment program was associated with a reduction in the number of cases treated on a hospital inpatient basis for alcohol-related problems, with a short-run drop of 27.1 hospital cases within 1 year of a community facility's availability and a long-run reduction of 52.2 cases. (P < .005).

Adult↗
PubMed1993

Atomic force microscopy of DNA in aqueous solutions.

DNA on mica can be imaged in the atomic force microscope (AFM) in water or in some buffers if the sample has first been dehydrated thoroughly with propanol or by baking in vacuum and if the sample is imaged with a tip that has been deposited in the scanning electron microscope (SEM). Without adequate dehydration or with an unmodified tip, the DNA is scraped off the substrate by AFM-imaging in aqueous solutions. The measured heights and widths of DNA are larger in aqueous solutions than in propanol. The measured lengths of DNA molecules are the same in propanol and in aqueous solutions and correspond to the base spacing for B-DNA, the hydrated form of DNA; when the DNA is again imaged in propanol after buffer, however, it shortens to the length expected for dehydrated A-DNA. Other results include the imaging of E. coli RNA polymerase bound to DNA in a propanol-water mixture and the observation that washing samples in the AFM is an effective way of disaggregating salt-DNA complexes. The ability to image DNA in aqueous solutions has potential applications for observing processes involving DNA in the AFM.

1-Propanol↗
PubMed1993

Organization of turnip yellow mosaic virus investigated by neutron small angle scattering at 80 K: an intermediate state preceding decapsidation of the virion?

The organization of turnip yellow mosaic virus has been investigated by neutron small angle scattering at 300 K and 80 K in buffers containing various amounts of D2O. We confirm that in native virions, no substantial part of the RNA is located at a radius larger than ca. 100-110 A, i.e., that there is very little interpretation of the RNA into the capsid. At 80 K, scattering curves do not depend much upon contrast, from 40% D2O to 100% D2O buffers, but are strongly affected by interparticle interference. We could, however, show that it is not the case for the subsidiary intensity maximum at q approximately 0.06 A-1. From the position of this maximum, we conclude that upon freezing, the radius of the capsid expands by c.a. 3.5% and the RNA penetrates deeply into the protein shell. Biological implications of this conformational change immediately preceding decapsidation are discussed.

Capsid↗
PubMed1993

Effect of ethidium on the morphology, antiviral activity and subcellular distribution of poly r(A-U).

When ethidium bromide (EB) is combined with poly r(A-U) at an EB/ribonucleotide ratio of 1/4, the antiviral activity of the EB increases 22-fold. The increased antiviral activity is not due to increased interferon induction, direct viral inactivation or host cell cytotoxicity. Phase contrast, confocal and fluorescence microscopic observations reveal an increase in the nucleolar accumulation of the EB and/or the poly r(A-U) in the EB/poly r(A-U)-treated fibroblasts. Ultrastructure of negatively stained and replica preparations demonstrated that EB-induced condensation of poly r(A-U). These results suggest the elevated antiviral activity may be related to the altered uptake and subcellular distribution of the EB/poly r(A-U) complex.

Antiviral Agents↗
PubMed1993

Proposal for a composite index of alcohol problems.

This study proposes constructing a composite index to measure the severity of alcohol problems in Canada. Composite summary indicators are used in many areas, particularly in economics where the Consumer Price Index is well known. The composite indexes developed for this analysis were constructed using the index number method. The indexes were based on the statistical series for alcohol consumption, alcohol morbidity, alcohol mortality and alcohol-related traffic offences in the ten provinces and cover the years 1975, 1980, 1985 and 1990. The selected statistical series were compared using both Spearman and the Pearson correlations. In addition, Kendall's coefficient of concordance was used to determine the degree of association among all the statistical series together. The initial results indicated that there were different provincial rankings for each of the four statistical series, demonstrating that in comparing provinces the ranking of the "alcohol problem" depends on the statistical series selected. The construction of a composite index can be an effective strategy for resolving these differences in the rankings. Provincial rankings for the composite indexes on the severity of alcohol problems were fairly consistent for each time period. In terms of general trends among the provinces, Prince Edward Island, Alberta, British Columbia and Saskatchewan had the highest composite indexes; Manitoba, Nova Scotia and Ontario the mid-range; and New Brunswick, Newfoundland and Quebec the lowest.

Accidents, Traffic↗
PubMed1993

Solution structure and direct imaging of fibronectin adsorption to solid surfaces by scanning force microscopy and cryo-electron microscopy.

In this study, we present the scanning force and electron microscopic visualization of single molecules of fibronectin either frozen hydrated or adsorbed onto metallic and polymeric surfaces with different solid surface tensions. The surfaces were characterized by dynamic contact angle measurements, X-ray photo emission spectroscopy (XPS or ESCA) and scanning force microscopy. The proteins were prepared by fast protein liquid chromatography (FPLC) and characterized by gel electrophoresis. Protein films on surfaces were investigated by surface plasmon resonance spectroscopy and directly imaged by scanning force microscopy. The spreading of the adsorbed fibronectin revealed dependence on the chemical composition and the solid surface tension. Structure of fibronectin in solution as well as on solid interface appeared as an extended straight strand as obtained by imaging with electron and scanning probe microscopies. Imaging of DNA was performed by scanning force microscopy to test the accuracy and reproducibility of our measurements. The measured contour lengths were accurate and the larger widths were caused by convolution of the tip shape and sample. Frictional forces during the scan have been of significant contribution in the imaging mechanism. Moreover, this work demonstrated that scanning force microscopy can be used for mapping the orientation and organization of protein film adsorbed onto various surfaces at the nanoscale.

Adsorption↗
PubMed1992

The apical localization of transcribing RNA polymerases on supercoiled DNA prevents their rotation around the template.

The interaction of Escherichia coli RNA polymerase with supercoiled DNA was visualized by cryo-electron microscopy of vitrified samples and by classical electron microscopy methods. We observed that when E. coli RNA polymerase binds to a promoter on supercoiled DNA, this promoter becomes located at an apical loop of the interwound DNA molecule. During transcription RNA polymerase shifts the apical loop along the DNA, always remaining at the top of the moving loop. This relationship between RNA polymerase and the supercoiled template precludes circling of the RNA polymerase around the DNA and prevents the growing RNA transcript from becoming entangled with the template DNA.

Binding Sites↗
PubMed1992

Scanning force microscopy and cryo-electron microscopy of tobacco mosaic virus as a test specimen.

In this study, tobacco mosaic virus (TMV) provides a resolution criterion for specimen preparation methods as well as for imaging parameters of the scanning force microscope (SFM). We present scanning force microscopic images of the virus embedded in 0.5% buffered phosphotungstic acid solution adsorbed on a freshly cleaved mica surface, and imaged under atmospheric conditions. Individual TMV particles were clearly identified with a characteristic shape of long rods of about 300 nm long and 60-70 nm in apparent width due to the geometric parameters of the tip. The structure of the virus was compared with cryo-electron microscopic data of vitrified suspensions observed to a resolution of 1.15 nm. Uncoated TMV particles were also deposited on evaporated titanium thin films and imaged by SFM.

Cryopreservation↗
PubMed1992

In vitro decapsidation of turnip yellow mosaic virus investigated by cryo-electron microscopy: a model for the decapsidation of a small isometric virus.

The in vitro decapsidation of a small isometric plant virus, turnip yellow mosaic virus (TYMV), was investigated by cryo-electron microscopy. Cryo-electron micrographs of TYMV and empty shells show that rapidly frozen virions still contain their RNA. Images of vitrified virions resemble closely those previously obtained by negative staining. Rapidly frozen virions decapsidate upon thawing although they remain well dispersed on the grid. The escape of the RNA through a hole at the periphery of the capsid could be visualized. The results suggest a model for the in situ decapsidation of small icosahedral viruses.

Capsid↗
PubMed1991

Secreted acid phosphatase of Leishmania mexicana: a filamentous phosphoglycoprotein polymer.

In the promastigote, or insect stage, most species of the parasitic protozoan Leishmania secrete an acid phosphatase. The enzyme purified from the culture medium of Leishmania mexicana is shown to be a complex [13.3% (wt/wt) protein, 74.4% (wt/wt) carbohydrate, and 12.3% (wt/wt) phosphate] composed of a predominant phosphorylated glycoprotein with a relative molecular mass of 100 kDa and noncovalently associated high molecular mass (proteo)phosphoglycans. Electron microscopy discloses long filaments composed of a central chain of protein subunits surrounded by a diffuse glycocalix that can be decorated by monoclonal antibodies or concanavalin A. In contrast to the polymeric structure of the L. mexicana enzyme, the acid phosphatase secreted by Leishmania donovani is mono- or oligomeric but not filamentous.

Acid Phosphatase↗
PubMed1991

The three-dimensional structure of reovirus obtained by cryo-electron microscopy.

The structures of reovirus serotypes T2J (Jones), T3D (Dearing) and the T3D core particle have been determined by cryo-electron microscopy and image processing. At a resolution of 30 A the two serotypes have similar features. The core is visible within the virus structure. The outer surface of the virus particles contains 120 holes at T = 13.1 local 6-fold axes. The holes penetrate into the virus as far as the surface of the internal core shell. Protrusions extending 4 nm from the virus surface surround each hole on the outside of the virus. At the 5-fold axes on the surface of the virus flat 'penton craters' form covers over the underlying core spikes. The detailed structure of the reovirus shell is very different to that of rotavirus although both have holes at T = 13.1 axes. Little evidence was seen of reovirus fibres extending from the virus surface.

Image Processing, Computer-Assisted↗
PubMed1991

Long-term trends in male drunkenness arrests in metropolitan Toronto: effects of social-setting detoxication centers.

Drunkenness arrest rates for adult males in Toronto decreased substantially during the period 1966 to 1987. In 1971 there was a change in legislation permitting police to take public inebriates to detoxication centers. Drunkenness rates continued to decline at a rate similar to that for the previous 3 years. The next year drunkenness arrests increased but subsequently declined at a rate which was 50% greater than that which preceded the change in legislation. Since 1973 year by year changes in the rate of male drunkenness arrests have not been consistently related to rates of police admission to detoxication centers or to total admissions to detoxication centers. The results suggest that recent trends in drunkenness arrests have been influenced by the 1971 change in legislation and the increased use of detoxication centers. However, the influence of other factors must also be considered.

Alcoholism↗
PubMed1990

Structure of adenovirus fibre. I. Analysis of crystals of fibre from adenovirus serotypes 2 and 5 by electron microscopy and X-ray crystallography.

An analysis by electron microscopy in amorphous ice and X-ray diffraction of four types of three-dimensional crystals of adenovirus fibre is presented. Fibre from adenovirus type 2 (Ad2) crystallizes in two forms depending on whether it is native or cleaved near the N terminus at Tyr17. Fibre from Ad5 also crystallizes in two forms, both of which contained fibre cleaved at Tyr17. Analysis of the packing of the fibres in each of these crystals suggests that the overall length of the fibre may be considerably longer (about 350 to 370 A) than previously reported. Crystals of cleaved Ad2 fibre are of sufficient quality to be characterized by X-ray diffraction. They are of space group C2 and cell dimensions a = 134.4 A, b = 77.6 A, c = 539.4 A, beta = 92.7 degrees. These crystals are remarkable in that, despite being monoclinic, the ab plane forms a perfect hexagonal lattice. This is explained by a trigonal packing of the trimeric fibre heads in the crystal. A similar feature is found for one type of Ad5 crystal, although the hexagonal lattice is 12% smaller. The crystals of cleaved Ad2 show very strong meridional intensity at a Bragg spacing of 4.4 A and weaker diffuse intensity corresponding to layer-lines of spacing 26.4 A. This must reflect the quasiperiodicity of the structure of the fibre shaft, which is apparent in the primary sequence. The occurrence of these features combined with the new determination of the length of the fibre (see also the accompanying paper) require a reappraisal of the cross-beta model of the fibre shaft proposed by Green et al.

Adenoviridae↗