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Biomedical subjects

J Prince

Publications and source records attributed to J Prince.

At least 19 recordsLinked to original sources
PubMed1990

Bioregulatory mechanisms at the level of cell organelle interactions: microspectrofluorometric in situ studies.

The spatiotemporal analysis of bioregulatory mechanisms at the level of intracellular multienzyme complexes and organelle interactions is made possible by the availability of endogenous and exogenous fluorescence probes, the development of microspectrofluorometers allowing one- and two-dimensional scans of intracellular fluorescence reactions, and the use of micromanipulatory techniques enabling the rapid alteration of metabolic states. Absorbed photons are not only a tool for quantitative evaluation of metabolic processes, they can also trigger alterations of cell membranes and functions as mediated by photosensitizer drugs. In the hierarchy of intracellular organization different levels of complexity are accessible to study, such as the regulation of multienzyme complexes and the interaction of organelle complexes. Typical applications of these methods are the investigation of drug effects (e.g., on melanoma cells), metabolic and structural alterations (e.g., in cystic fibrosis and Gaucher fibroblasts), organelle interactions in cells treated with toxic agents. The implications are relevant to biotechnology for better control of metabolite production and processing, design and testing of new drugs, understanding of drug resistance and better targeting of drugs or probes to selected intracellular sites. In addition, such in vitro methods can contribute to the provision of an alternative to "whole animal experiments" as already achieved in human and mouse fibroblasts, hepatocytes, hepatoma, Swiss 3T3 cells and other cells in culture, especially with regards to an analysis of the action of xenobiotics and drugs in cell physiology and pathology, fluorescence recovery after photobleaching, study of cytoskeleton dynamics and multiparameter probing of organelle activity during in vitro wound repair.

Animals↗
PubMed1989

Mental health in Dutch adolescents: self-reported competencies and problems for ages 11-18.

Beside parents and teachers, adolescents themselvess may be valuable informants about their own psychological functioning. The present study, which provides prevalence data on behavioral/emotional problems and competencies reported by adolescents aged 11-18 from the general population, was preceded by two studies providing such data for parent and teacher reported problems. The instrument used in the present study is the Youth Self Report (YSR) developed by Achenbach and Edelbrock to obtain adolescents' self-reports on their problems and competencies in a standardized way. YSRs completed by 52 adolescents on two occasions with a time-interval of 3-4 weeks revealed test-retest reliability expressed as intraclass correlation coefficients of 0.87 for total problem scores and 0.69 for total competence scores. The YSR was completed by 941 adolescents aged 11-18 from the general population. For each of the 103 problem items and 17 competence items, the prevalence rates were presented graphically for both genders in two-year age-groups. To identify differences related to sex, age and socio-economic status (SES), ANCOVAs were performed on the scores for each problem and competence item as well as on total problem and total competence scores. Whereas the level of problem scores was the same across the 11-18 years age-span, girls obtained higher total problem scores with increasing age. Younger girls scored lower and older girls scored somewhat higher than boys. Implications of these findings with respect to sex differences in referral rates for children and adults are discussed. The increase with increasing age in self-reports of problems concerning inner feelings and thoughts may reflect the adolescent's change in cognitive, socio-emotional and physical functioning. We could not demonstrate significant SES differences in problem scores. Comparisons of problem scores obtained for referred and nonreferred adolescents revealed a correct classification rate of 73.6%, which seems satisfactory given the fact that parents rather than the adolescent usually initiate referrals. Comparisons of problem item scores in ANCOVAs of referred and nonreferred samples revealed significant referral status effects for 68 of the 103 problem items, with referred adolescents scoring higher than nonreferred adolescents. The largest effect of referral status was found for the item "Nervous". The third largest effect was obtained for the item "Unhappy, sad, depressed", which also showed strong discrimination between parent scores for referred and nonreferred samples. Competence scores showed much weaker discrimination between referred and nonreferred groups.

Adolescent↗
PubMed1989

Molecular pathobiology of human collagens.

The fibril-forming collagens (types I-III, V and XI) represent a homogeneous and evolutionary related group of proteins and genes. In addition to serving as supportive elements, these macromolecules influence the spatial and ontogenic diversity of extracellular matrices, for they regulate a number of developmental programs and cellular activities, such as adhesion, proliferation and migration. Deranged expression of fibrillar collagen genes results in a number of inherited and acquired disorders which greatly affect the structural integrity of the organism. An understanding of collagen biosynthesis and regulation in normal and diseased states provides an opportunity to dissect biological problems which relate to a wide variety of subjects, including morphogenesis, relationships between structure and function of proteins, gene expression and human mutations.

Animals↗
PubMed1985

An analysis of margin configurations for metal-ceramic crowns.

Major types of margin configurations for ceramometal crowns are reviewed. This is one of the most commonly misunderstood and poorly practiced aspects of fixed prosthodontics. The resultant underprepared teeth produce discolored gingiva and chalky crowns.

Crowns↗
PubMed1975

A membrane filter technique for testing disinfectants.

A membrane filter was used for assessing the surface disinfecting activity of phenolic disinfectants and a chloroxylenol disinfectant. The influence of the type of organism, inoculum size, and hardness of water was investigated. Pseudomonas aeruginosa was chosen for the standardized test. Disinfectant solutions were prepared in water of 300 ppm hardness and applied for two and a half minutes and eight minutes to the bacteria deposited from filtration of 1 ml of a suspension containing 10-6 bacteria. The membrane filter test has certain advantages over many tests, eg, all organisms surviving after treatment can be counted and residual disinfectant is easily removed.

Cell Count↗
PubMed1972

In-use testing of disinfectants in hospitals.

One hundred and five samples of clear, soluble phenolic disinfectants were obtained from varying sites in the wards of six hospitals. The concentration of disinfectant in each sample was measured by a colorimetric method and bacterial contamination was measured by an ;in-use' test and a membrane filter technique. The concentrations of disinfectant in 24/105 (23%) samples were at the recommended level and 53 (50.5%) were below. Bacterial contamination with Gram-negative bacilli was found in 26/49 (53%) samples containing less than 0.8% of disinfectant and 5/86 (8.9%) samples containing more than 0.8%. The concentrations in two of the heavily contaminated samples were 1.5% and 1.6% respectively.

Bacteria↗
PubMed1971

Mental health aspects of shoplifting.

A ten-year follow-up of 886 shoplifters showed clear differences between women and men. Men tended to have previous convictions and to steal books (unknown in women). Of the 532 women nearly one third were foreign-born, and this group comprised 46% of offenders aged 17-30. The peak age among British women was 51-60.First offenders accounted for 80% of the women, and their reconviction rate was 11%; among those with any kind of previous conviction the rate was 50%. The rate of admission to hospital for women shoplifters is three times higher than average.

Adolescent↗