Biomedical subjects

M E Maitland

Publications and source records attributed to M E Maitland.

5 recordsLinked to original sources

PubMed1994

A client-computer interface for questionnaire data.

Our purpose was to assess efficiency and patient acceptance of a simple, inexpensive method of direct client-computer interface. A computerized version of the Sickness Impact Profile (SIP) was developed with the standard keyboard replaced by a numeric keypad. Forty-eight volunteer clients of an occupational rehabilitation center completed both the paper format and the computer format in randomized order, then were asked to compare the two methods in four areas. The majority of subjects rated the computer as easier to use and as the preferred method. Most subjects rated the computer and paper formats as equivalent in comfort and understanding. A summary score established that significantly more individuals preferred the computer format over the paper format (p = .02). Efficiency was determined by the mean time to score the test and produce a report (computer 39s, paper 309s). The correlation coefficients for the physical, psychosocial, and overall scores were very acceptable being greater than 0.90. These data indicate that a simple client-computer interface for the SIP is preferred by clients and is more efficient compared to the paper and pencil format.

Adult↗

PubMed1991

A correlation between the distribution of biological apatite and amino acid sequence of type I collagen.

We have determined the localization of apatite within type I collagen fibrils of calcifying turkey leg tendons by both bright field and selected-area dark field (SADF) electron microscopy and have compared this to computer-modeled, chick type I collagen amino acid sequence data. Apatite crystals occur in both the gap and overlap zones at early stages of mineralization in an asymmetric pattern that corresponds to the polarity, N- to C- orientation, of the collagen molecule. Based on comparisons with computer-generated models of known amino acid sequence of collagen, it was determined for early stages of mineral deposition that apatite is restricted by areas of high hydrophobicity. The gap zone is less hydrophobic than the overlap zone on average but each of these zones had areas of high hydrophobicity that correlated with sites of low localization of mineral. Possible interactions between hydrophobic regions and the process of mineral deposition are discussed.

Amino Acid Sequence↗

PubMed1990

Histochemical classification based upon reaction types and its application to carbohydrate histochemistry.

A method of classification is presented, which divides histochemical visualization reactions into categories based on general reaction types. This scheme is dependent upon the reaction between two elements, the substrate and the probe. The substrate represents a tissue component(s) with one or more reactive groups that can combine directly with the probe. Alternatively, the substrate reactive groups are chemically modified (activation) with a suitable reagent before reaction with the probe. Probes are of three types: those that yield a coloured product, those that result in a colourless product, and those that produce a coloured product only after a further reaction. Methods used in carbohydrate histochemistry are divided into one, two and three probe reactions. Two probe reactions are further subdivided into sequences involving one or two coloured products (one and two dye sequences); three probe reactions into sequences involving one, two or three coloured products (one, two and three dye sequences). This classification permits the rationalization and organization of methods, and provides a framework for the examination of existing methods and the development of new ones.

Carbohydrates↗

PubMed1989

Freeze-substitution staining of rat growth plate cartilage with alcian blue for electron microscopic study of proteoglycans.

To selectively stain polyanionic macromolecules of growth plate cartilage and to prevent artifacts induced by aqueous fixation, proximal tibial growth plates were excised from rats, slam-frozen, and freeze-substituted in 100% methanol containing the cationic dye Alcian blue. Electron microscopic examination showed the tissue stained with Alcian blue to be comparable in ultrastructural preservation to tissues slam-frozen and freeze-substituted in the absence of Alcian blue. The extracellular matrix exhibited a characteristic staining pattern when stained by this method. The pericellular rim was identified as a band of varying width encircling the chondrocyte and its cell processes. Peripheral to the pericellular rim the heterogeneity of staining within the extracellular matrix increased, taking the form of polymorphic densities. X-ray microanalysis showed that the visual interpretation of electron density was related to the concentration of copper present, and that the concentration of sulfur was variable in the pericellular rim and in the interterritorial matrix. The difficulties associated with aqueous fixation and staining procedures are discussed in contrast to the improved preservation achieved by cryogenic methods.

Alcian Blue↗

PubMedDate not supplied

Does Cybex testing increase knee laxity after anterior cruciate ligament reconstructions?

Long-term stability of the knee after anterior cruciate ligament reconstruction is imperative. Testing protocols that use isokinetic systems are commonly performed despite controversies as to their safety. The purpose of this study was to test whether one episode of isokinetic testing would cause an increase in anterior tibial translation. Twenty-four subjects who had anterior cruciate ligament reconstructions 153 to 300 days earlier volunteered for the study. Initially, subjects walked on a treadmill at 5 km/hr for 10 minutes to test the effect of exercise on displacement measurements. One week later, subjects performed a maximal knee flexion-extension test on the Cybex dynamometer at 60, 150, and 240 deg/sec. Anterior tibial displacement at 133.5 N was obtained from force-displacement curves produced by KT-2000 arthrometer testing at nine intervals: before exercise on the treadmill, at four intervals after treadmill exercise, and at four intervals after Cybex testing. Repeated measures analysis of variance did not show a significant exercise effect, interaction between type of exercise and time interval, or change after Cybex testing for the reconstructed knee displacement, the contralateral knee displacement, or side-to-side difference. The average difference before and after Cybex testing was 0.1 mm for the reconstructed knee. In conclusion, a single Cybex test, performed at least 6 months after surgery, did not affect anterior tibial displacement in this study sample.

Adolescent↗