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Biomedical subjects

J R Griffin

Publications and source records attributed to J R Griffin.

At least 19 recordsLinked to original sources
PubMed2001

Failure of blue-tinted lenses to change reading scores of dyslexic individuals.

BACKGROUND: This study was designed to address a perceived major flaw in past studies investigating tinted lenses and dyslexia; i.e., the lack of a direct, scientifically validated means of diagnosing the type and severity of dyslexia. METHODS: Sixteen 5th and 8th grade students, found to be dyslexic based on testing via the Dyslexia Determination Test (DDT), were randomly divided into two groups of eight. One group was tested first with blue filters (then, 2 to 5 weeks later, no filters) using the Gates MacGinitie Reading Test for reading comprehension. The other group of eight was tested in the same way, first with no filters, then 2 to 5 weeks later with blue filters. The grade level of the test used for each subject was in accord with the DDT decoding level. RESULTS: There was no significant difference in reading comprehension level or reading speed when the blue filter condition was compared to the no filter condition. CONCLUSIONS: Using DDT classification, subjects were found to have mostly dysphoneidetic (mixed pattern) dyslexia. Among this population of dyslexic students, tinted lenses appeared to provide no beneficial effect. We offer an explanation based on neuro-anatomical relationships between the visual system and reading centers in the brain. The hypothesis states that the transient system defect may be an epiphenomenon, which can coincidentally occur in cases of reading disability.

Adolescent↗
PubMed1999

Factors predictive of quality of life after silicone-implant explanation.

'Medical records of 180 patients who underwent silicone gel-filled breast implant explanation were retrospectively reviewed. The goal of this study was to determine if any patient variable(s) had predictive value for positive quality of life after explanation. The medical complaints, symptoms, and established diagnoses were considered equally and were referred to as self-reported medical problems. The study revealed that no single problem or pairing of problems was associated with or predictive of outcome. The results show, however, that the number of medical problems was significantly predictive of patient perception of quality of life. A total of 50 explanation patients completed quality-of-life surveys. Specifically, those patients who reported five or fewer medical problems that predated explantation were significantly more likely to perceive an increased quality of life after surgery than those who reported nine or more medical problems (p < 0.04). In conclusion, it is difficult to correlate subjective patient symptoms with postoperative improvements in quality of life after explantation.

Attitude to Health↗
PubMed1998

The myoadipose flap: a new composite.

A prefabricated composite fat flap consisting of muscle woven into an anatomically distinct fat pad was studied in a rabbit model. In 17 rabbits, a 2-cm strip of latissimus dorsi was woven into the parascapular fat pad on one side, with the contralateral fat pad serving as a control. At 3 weeks, the endogenous blood supply of both the control and the experimental fat pads was isolated and ligated, and the composite fat/muscle flap was transferred to the chest wall. At 6 weeks, animals were killed, and flaps were analyzed for length, width, and weight; perfused with fluorescein or lead oxide; and examined histologically. Significant differences were found between the control and experimental fat pads with regard to weight and length. Experimental flaps were found to be perfused fully with fluorescein and lead oxide; control fat pads were found not to be perfused. The lead oxide group revealed extensive growth of blood vessels from the latissimus graft into the experimental fat pad. No vessels were visualized in the controls. Finally, sections of the control and experimental flaps were analyzed histologically. A preponderance of viable fat, with evidence of neovascularization, was found in experimental flaps, compared with the necrotic fat that characterized the controls. We conclude that prefabrication of a fat flap is possible and may have extensive application in various areas of plastic surgery.

Adipose Tissue↗
PubMed1995

Referrals by optometrists to ophtholmologists and other providers.

BACKGROUND: This study reviews 33 years of research into referrals made by optometrists, estimates mean referral rates and seeks to interpret what they mean. METHODS: A search of the medical and optometric literature, 1961-1993, disclosed all reports on referrals by optometrists. Techniques of meta-analysis were employed to rationalize results from various research designs. Principal variable: percent of patients referred by optometrists to 1) ophthalmologists and 2) all providers. Mean referral rates were estimated by log-scale weighting and computed separately by type of practice. Also reviewed: referral rates by eye condition and anatomic site. RESULTS: We found 15 research studies in which referral rates were indicated or could be inferred. On average, optometrists referred 3.83 percent of their patients to ophthalmologists; 5.50 percent to all providers. Cataract and glaucoma were the most common conditions referred; anterior eye and retina the most common anatomic sites. CONCLUSIONS: No time trend was apparent. Referral rates varied by type of practice, with VA clinics high, HMOs and teaching clinics low, and private practices intermediate. Optometrists in private practice appear to be referring patients at rates consistent with referrals by optometrists who practice in more managed environments.

Eye Diseases↗
PubMed1994

Genetics review: relation to ocular disease.

This study is a review of modes of transmission of genetic traits, how they relate to ocular diseases, and abnormalities frequently seen by primary eye care practitioners. Traits showing autosomal dominant (AD), autosomal recessive (AR), X-linked (XR) recessive, chromosomal aberrations, and multifactorial (M) inheritance are listed. General guidelines for genetic counseling are given.

Chromosome Aberrations↗
PubMed1994

Effect of hypercapnia on laryngeal airway resistance in normal adult humans.

Laryngeal airway resistance (Rlar) was measured in eight normal adult humans during progressive hyperoxic hypercapnia. In most subjects, the translaryngeal pressure-flow relationship appeared linear under normocapnic conditions. During hypercapnia, the pressure-flow relationship on inspiration and expiration was curvilinear with increasing translaryngeal pressure associated with progressively smaller increments in flow. Translaryngeal pressure-flow relationships at different CO2 levels were compared over their common flow ranges by performing a least-squares linear regression on data throughout inspiration and expiration. During normocapnia, the mean slope, i.e., mean Rlar, was 0.50 +/- 0.21 (SD) cmH2O.l-1.s. A moderately significant decrease in Rlar was present at 9% end-tidal CO2 (P = 0.08). In a separate series of experiments, subjects breathed oxygen- and helium-based gas mixtures through a face mask attached to a pneumotachograph. Data analysis over the flow range present during normocapnia revealed no difference in Rlar between nose and mouth breathing and similar decreases in Rlar under hypercapnic conditions with the oxygen- and helium-based gas mixtures. The decrease in Rlar from normocapnic to hypercapnic conditions found over common, but relatively low, ranges of flow predicts that even greater increases in Rlar would occur at high flow rates in the absence of increasing glottic aperture.

Adult↗
PubMed1993

Effect of ibuprofen on monocyte activation by liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (CGP 19835A): can ibuprofen reduce fever and chills without compromising immune stimulation?

The purpose of this study was to determine the effects of ibuprofen on the ability of liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) to activate human blood monocytes in vitro. We undertook these experiments because the major toxic side-effects following L-MTP-PE infusion, fever and chills, could be prevented when ibuprofen was given orally immediately before L-MTP-PE infusion. It was therefore important to determine whether ibuprofen interfered with the macrophage-activation properties of L-MTP-PE. Peripheral blood monocytes were isolated from normal donors, then incubated with L-MTP-PE in the presence or absence of ibuprofen. The cytotoxic properties of the monocytes were assessed by a radioisotope-release assay against A375 cells. Ibuprofen at dose levels of 40 micrograms/ml suppressed the generation of the cytotoxic phenotype but did not interfere with the killing process once the cells were activated. Interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) production, as well as the mRNA expression of these cytokines, was suppressed by 40 micrograms/ml ibuprofen. Since IL-1 and TNF play a crucial role in the cytotoxic function of monocytes, these findings may explain the mechanism by which ibuprofen inhibited the generation of the cytotoxic phenotype by L-MTP-PE. By contrast, ibuprofen dose levels up to 10 micrograms/ml had no effect on the generation of monocyte-mediated cytotoxicity by L-MTP-PE and no effect on the production, secretion, or mRNA expression of TNF and IL-1. Therefore, we concluded that if ibuprofen is to be used to control the side-effects of L-MTP-PE, blood levels of up to 10 micrograms/ml are desirable. In two of three patients, we determined that an oral dose of 200 mg given immediately before L-MTP-PE infusion could achieve these desired blood levels.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1993

Dyslexic subtypes and severity levels: are there gender differences?

The prevalence of dyslexia among 100 children participating in a longitudinal study was examined. At age 10 years, The Dyslexia Screener (TDS) test, a direct assessment of coding skills used in reading and spelling, was administered. The incidence of suspected dyslexia of borderline or worse severity among boys and girls was not significantly different, nor did males and females differ significantly in terms of TDS-suspected dyslexic types of severity levels. Results challenge the widely held belief of an increased incidence of reading disability among males and, in conjunction with findings from other recent studies, underscore the need for establishing objective and reliable screening procedures in addition to teacher referral in identifying children in need of special services. Possible factors mediating previous estimates of incidence and the implications of these findings are discussed.

Child↗
PubMed1993

Dyslexia and visual perception: is there a relation?

Opinions differ concerning the relation between dyslexia and visual perception. In this pilot study we addressed this question by analyzing the results of visual perceptual testing on 19 elementary grade subjects diagnosed as having dyseidesia, one type of dyslexia that manifests as problems with sight-word recognition. The subjects, who have different degrees of severity of dyseidesia, were compared with 11 subjects tested as nondyslexic, but with reading problems. The Dyslexia Determination Test (DDT) and the Test of Visual Perceptual Skills (TVPS) were given to all subjects. Both multivariate analysis of variance (MANOVA) and univariate one-way analysis of variance (ANOVA) to test for differences in performance among four test groups (ranging from nondyslexic to increasing levels of severity of dyseidesia) showed no trends of either statistical or clinical importance. An individual with reading problems may be nondyslexic but have poor visual perceptual skills, or may be dyslexic with good visual perceptual skills. These results are consistent with the contention that reading problems caused by dyseidesia (as defined by the DDT) and those caused by visual perceptual deficiencies (as defined by the TVPS) are different. Although dyseidetic dyslexia results in characteristic coding patterns producing specific reading problems, it is probable that visual perceptual deficiencies contribute to learning problems that include general reading problems. Each condition would, therefore, require different forms of therapy. Limitations of this study and recommendations for future research are discussed.

Adolescent↗
PubMed1992

Genetics of dyseidetic dyslexia.

The nine pedigrees presented here suggest an autosomal dominant mode of transmission for the dyseidetic type of dyslexia. Sex-influence probably accounts for the high male to female ratio. Other modes of transmission are highly unlikely for dyseidesia but possible for other types of dyslexia, with the multifactorial mode being most likely. Genetic counseling is particularly feasible in cases of dyseidetic dyslexia.

Adolescent↗
PubMed1991

Validity of the dyslexia screener.

Optometrists see many patients who complain of reading difficulty. The Dyslexia Screener (TDS) is an instrument which has been developed to determine, within 5 min, whether or not a patient shows evidence of having one of the three basic types of dyslexia (a coding problem in reading and spelling). Results using TDS were compared with the Dyslexia Determination Test (DDT). TDS rating scores were shown to contain much of the same clinical information as the DDT rating scores.

Adolescent↗
PubMed1990

Optometry's role in reading disabilities: resolving the controversy.

Optometry's involvement in the management of reading disabilities is often misunderstood. This paper clarifies the confusion surrounding specific reading disabilities and optometric vision therapy in the management of them. Topics include a historical review of dyslexia, theories of brain function, and a neuroanatomical model, as well as operational definitions and behavioral characteristics of the types of dyslexia. Methods for direct diagnosis of coding deficits in specific reading disability (dyslexia) are discussed. This approach explains the beneficial role of optometric vision therapy in the management of patients with reading problems.

Dyslexia↗
PubMed1989

Acute iritis. How to preserve good vision.

Acute iritis, which is often seen in young adults, may cause red eye, photophobia, and aching discomfort. Many times, the condition can be ameliorated or completely reversed by cautious use of cycloplegic agents and corticosteroids. However, undiagnosed or improperly treated iritis can lead to glaucoma and loss of vision.

Adrenal Cortex Hormones↗
PubMed1989

Photographic method for Brückner and Hirschberg testing.

An apparatus for strabismus detection was designed to allow photographing fundus and corneal reflexes for Brückner and Hirschberg testing, respectively. Photographs of adult subjects with simulated strabismic deviations were viewed by two groups of observers, optometry students and optometry faculty. In general there was no significant difference in testing results between the two groups. Subject error produced unreliable Brückner results. However, Hirschberg testing was effective approximately 80% of the time in detecting a deviating eye in strabismus of magnitudes of about 5 delta. Anisometropia in Brückner testing was also investigated. Magnitudes of 2.00 D or greater significantly affected results. Clinical application of the photographic Hirschberg test may have potential value as a screening method. The photographic Brückner test is not recommended for adults; its reliability in children requires investigation.

Equipment Design↗