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Biomedical subjects

R E Williams

Publications and source records attributed to R E Williams.

At least 145 records · Page 8Linked to original sources
PubMed1982

Biofeedback-induced relaxation training as an alternative for the elementary school learning-disabled child.

This study examined the effects of biofeedback-induced relaxation training on attention to task, impulsivity, and locus of control among 32 learning-disabled children between the ages of 8 and 11 years. Attention to task and impulsivity were measured by the Matching Familiar Figures Test and locus of control was measured by the Nowicki-Strickland Scale. Participants were randomly assigned to experimental (N = 16) and control (N = 16) groups. The study spanned a total of 8 weeks, with the experimental treatment consisting of three sessions spaced approximately 2 weeks apart. The treatment included EMG biofeedback training used with relaxation tapes. Univariate F values and discriminant analysis procedures revealed that the attention to task and impulsivity measures proved to be valid discriminators, respectively beyond the .01 and .05 levels of significance. Experimental group subjects had significantly fewer number of errors on the attention to task measure and significantly lower impulsivity scores. It was concluded that the biofeedback-induced relaxation training affords promise in assisting learning-disabled children in reaching their education potentials. It was recommended that future research examine the long-term efficacy and the transfer to school-related tasks of this intervention.

Attention↗
PubMed1982

Secondary structural properties of the oligomeric forms of mouse IgA and the unusual effect of guanidine hydrochloride.

The circular dichroism spectra of the monomer, dimer and tetramer forms of MOPC 167 mouse IgA are reported. The spectra were very similar in the aromatic region (250-310 nm) but the intensity of the negative band at 217 nm, arising from the peptide backbone, was higher in the dimer and tetramer (-4600 degree cm2 dmol-1) than in the monomer (-3400 degree cm2 dmol-1). When monomer and dimer IgA were exposed to concentrations of guanidine hydrochloride around 1.3 m, the 217 nm band increased in intensity, twofold in the case of the monomer, and solutions of the dimer became turbid, indicating aggregation of the proteins and formation of a cross-beta-structure. At concentrations of guanidine hydrochloride of above 2.3 M both proteins were similarly denatured, indicating that dimerization through J chain does not alter the stability of IgA. The aggregating effect of guanidine hydrochloride did not occur with samples of human IgA1 and IgA2 and may be related to the unusual CH1 domain of mouse IgA.

Animals↗
PubMed1982

Histological appearances of the nerves of the bladder in patients with denervation of the bladder after excision of the rectum.

Two groups of patients who developed denervation of the bladder after excision of the rectum for carcinoma have been studied by histological examination of bladder biopsies. The groups were compared with a group of control patients of a similar age. One group with denervation of the bladder was studied soon after (7 weeks) and the other group in the long term (10 months) after operation. Bladder biopsies were stained for acetylcholinesterase, catecholamines and connective tissue. Tissue was also processed for electron microscopy. In control patients, the ratio of cholinesterase positive nerves to the number of smooth muscle nuclei (24:100) was significantly greater than in patients with denervation of the bladder studied soon after operation (2.5: 100; P less than 0.01). Appearances consistent with degenerate nerve terminals were observed on electron microscopy in these patients. No increase in the density of adrenergic nerves was observed in either group of patients with denervation of the bladder. In the long term, a greater density of cholinergic innervation was noted compared with patients studied soon after operation (P less than 0.05). In addition, nerve terminals, similar in appearance to those of control patients, were observed on electron microscopy. The findings in patients with denervation of the bladder studied in the long term after operation are consistent with partial regeneration of autonomic nerves. They suggest that, whilst histological examination of bladder biopsies may be useful soon after excision of the rectum, they may be less sensitive in the long term.

Adrenergic Fibers↗
PubMed1982

Structural comparison of the lectin from sainfoin (Onobrychis viciifolia) with concanavalin A and other D-mannose specific lectins.

The D-mannose specific lectin from sainfoin was prepared by affinity chromatography on Sephadex G-75, and its circular dichroism (CD), metal content, antigenic character, and N-terminal amino acid sequence were compared with those of four lectins from Vicieae plants and concanavalin A. The sainfoin lectin was only slightly more closely related to these other D-mannose specific lectins, than to lectins of leguminous plants in general. The CD and antigenic experiments also confirmed the close relationship of the four Vicieae lectins. The N-terminal sequence showed sainfoin has two isolectins, differing in sequence at residue four. The sequence was homologous to N-terminal sequences of several other lectins; hence, despite some structural and specificity similarities, the sainfoin lectin does not show the circular permutation of sequence unique to concanavalin A. This region also contained the sole cysteine residue, at position 33. The carbohydrate-binding properties of the sainfoin lectin were studied by gradient affinity chromatography. Its apparent Ka for methyl alpha-D-glucoside was approximately 10(3) M-1, close to the Ka of the pea lectin. However, in the relative binding behaviour of methyl alpha-D-mannoside, maltose, and methyl alpha-D-glucoside, it resembled concanavalin A more than the pea lectin.

Amino Acid Sequence↗
PubMed1981

The Baylor Video Acuity Tester.

A device has been developed that offers many advantages not available with traditional visual acuity testing methods. The Baylor Video Acuity Tester (BVAT) produces randomized targets, size selectable at electronic speeds for testing even in normal ambient room light. Comparisons of the BVAT with the Project-O-Chart (American Optical Corp, Southbridge, Mass) on 60 subjects yield correlations of .93 and .95. A test-retest correlation of the BVAT of .88 was found.

Adolescent↗
PubMed1981

Use of insecticide-impregnated ear tags for the control of face flies and horn-flies on pastured cattle.

Three studies were conducted to evaluate the effectiveness of insecticide-impregnated ear tags in controlling face flies, Musca autumnalis DeGeer, and horn flies, Haematobia irritans (Linn.), on pastured beef cattle. In one 16-week trial, polyvinyl chloride (PVC) ear tags treated with stirofos (Rabon) insecticide reduced horn fly numbers by 79% (P less than .05) and face fly numbers by 30% (P less than .05). Coumaphos (Co-Ral) insecticide dust bags used in a separate herd produced an 86% (P less than .05) reduction in horn flies and an 18% (P less than .05) reduction in face flies. In the second study, 5 and 10% permethrin (Atroban), PVC-treated ear tags in a one-piece design were tested. In this 11 week trial, horn fly control averaged 95% (P less than .05) with the 10% tag and 77% (P less than .05) with the 5% tag. Face fly control averaged 49% (P less than .05) for 8 weeks with the 10% permethrin tag. No significant face fly control was achieved with the 5% permethrin tag. In a herd treated with coumaphos dust bags, horn fly control averaged 93% (P less than .05) and face fly control averaged 34% (P less than .05). The third study tested 5 and 10% permethrin, PVC-treated ear tags in a two-piece design and two-piece 5% permethrin-treated ear tags in a polyurethane matrix. Fourteen-week horn fly control averaged 88% (P less than .05) with the 10% PVC-treated tag, 83% (P less than .05) with the 5% PVC-treated tag, 71% (P less than .05) with the 5% polyurethane-treated tag and 74% (P less than .05) with coumaphos dust bags. Face fly control averaged less than 50% (P greater than .05) throughout the trial with all treatments.

Animals↗
PubMed1981

Self-instruction in dental education: 1960-1980.

An extensive, critical review of the dental education literature of the last two decades, related to self-instruction, reveals that this method is capable of significantly increasing cognitive knowledge in a shorter period of time and with increased student satisfaction, compared to conventional instructional methods. Suggestions for more detailed investigation of self-instructional techniques, and the need to develop a more integrated curriculum using self-instructional materials, small group interaction, and formal lectures are presented.

Attitude↗
PubMed1980

Dermacentor variabilis: uncomplicated eyelid involvement.

Ocular eyelid infestation of Dermacentor variabilis, the American dog tick, occurred in a 34-year-old man who had been sleeping in an open-floored tent in an Indiana field. The tick was mechanically removed with steady and firm pressure with cilia forceps, with care taken to remove all mouth structures. The involved eyelid area healed rapidly without ocular or systemic complications.

Adult↗
PubMed1980

Control of northern fowl mite with permethrin and fenvalerate, two synthetic pyrethroid compounds.

Trials were conducted to evaluate the efficacy of permethrin and fenvalerate, two synthetic pyrethroid compounds, for the control of the northern fowl mite, Ornithonyssus sylviarum (Canestrini and Fanzago), on White Leghorn hens. Fenvalerate at .0125%, .025%, and .05% active ingredient (ai) were as effective as carbaryl at .5% ai for 56 days posttreatment. Permethrin at .01%, .025%, and .05% ai were as effective, or better than, malathion at .27% ai for 56 days posttreatment. All treatments were applied to the birds as high pressure sprays.

Animals↗