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Biomedical subjects

C Barry

Publications and source records attributed to C Barry.

At least 19 recordsLinked to original sources
PubMed2001

Neurobehavioral symptoms in childhood closed-head injuries: changes in prevalence and correlates during the first year postinjury.

OBJECTIVE: To examine changes in the prevalence and correlates of neurobehavioral symptoms during the first year following childhood closed-head injuries (CHIs). METHODS: Participants included 31 children with severe CHIs, 38 with moderate CHIs, and 53 with orthopedic injuries (OIs). Children and their families were assessed shortly after injury and at 6- and 12-month follow-ups. Parents rated 15 symptoms classified as either cognitive/somatic (C/S) or emotional/behavioral (E/B). RESULTS: Both kinds of symptoms were more common in the CHI groups than in the OI group. C/S symptoms declined in the CHI groups over time, whereas E/B symptoms became relatively more common. Measures of injury severity, children's premorbid behavioral adjustment, and concurrent cognitive functioning predicted C/S symptoms. E/B symptoms were predicted by injury severity, concurrent cognitive functioning soon after the injury, and concurrent parent and family functioning later in time. Both types of symptoms contributed to the prediction of perceived family burden, with the relationships strengthening over time. CONCLUSIONS: The findings indicate that the prevalence and correlates of neurobehavioral symptoms in childhood CHIs vary as a function of symptom type and time since injury.

Child↗
PubMed2001

Modulation of cellular and viral gene expression by the latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus.

Kaposi's sarcoma-associated herpesvirus (KSHV), also called human herpesvirus 8 (HHV-8), is the likely etiological agent of Kaposi's sarcoma and primary effusion lymphoma. Common to these malignancies is that tumor cells are latently infected with KSHV. Viral gene expression is limited to a few genes, one of which is the latency-associated nuclear antigen (LANA), the product of ORF73. Examination of the primary sequence of LANA reveals some structural features reminiscent of transcription factors, leading us to hypothesize that LANA may regulate viral and cellular transcription during latency. In reporter gene-based transient transfection assays, we found that LANA can have either positive or negative effects on gene expression. While expression of a reporter gene from several synthetic promoters was increased in the presence of LANA, expression from the human immunodeficiency virus (HIV) long terminal repeat (LTR)-and from NF-kappaB-dependent reporter genes-was reduced by LANA expression. In addition, the promoter of KSHV ORF73 itself is activated up to 5.5-fold by LANA. This autoregulation may be important in tumorigenesis, because two other genes (v-cyclin and v-FLIP) with likely roles in cell growth and survival are also controlled by this element. To identify cellular genes influenced by LANA, we employed cDNA array-based expression profiling. Six known genes (and nine expressed sequence tags) were found to be upregulated in LANA-expressing cell lines. One of these, Staf-50, is known to inhibit expression from the HIV LTR; most of the other known genes are interferon inducible, although the interferon genes themselves were not induced by LANA. These data demonstrate that LANA expression has effects on cellular and viral gene expression. We suggest that, whether direct or indirect in origin, these effects may play important roles in the pathobiology of KSHV infection.

Animals↗
PubMed2000

When does a deep dyslexic make a semantic error? The roles of age-of-acquisition, concreteness, and frequency.

Semantic reading errors are the central and defining feature of deep dyslexia. This study compared the words the deep dyslexic patient LW read correctly with those she omitted and those to which she produced semantic errors in terms of their concreteness, age-of-acquisition, frequency, and length. Semantic errors were made to less concrete, later-acquired, and shorter words than were read correctly; there was no reliable effect of word frequency. More importantly, the actual semantic errors produced were later-acquired than the stimulus words, but they were not more concrete or reliably more frequent. These results implicate age-of-acquisition in the process that produces semantic errors. It is proposed that concreteness determines the specificity of the semantic system to activate a set of candidate responses and that age-of-acquisition biases the ease with which certain words can be selected from this set to be produced as reading responses.

Age Factors↗
PubMed2000

Dialect and authography: some differences between American and British spellers.

Two experiments examined whether American and British university students make different kinds of spelling errors as a function of the differences between their dialects. The American students spoke a rhotic dialect, pronouncing an /r/ in such words as leper, hermit, horde, and gnarl. The British students, with their nonrhotic dialect, did not include an /r/ in such words. The dialect differences led to different spelling errors in the 2 groups. For example, the British students sometimes misspelled horde as "haud" because its vowel has the alternative spelling au in their dialect. They sometimes spelled polka as "polker" because its final vowel is often spelled as er in other words. The U.S. students were much less likely to make such errors, although they did make other errors that reflected aspects of their dialect. Phonology, far from being superseded by other strategies in the development of spelling, continues to be important for adults.

Adult↗
PubMed2000

Fred Hollows lecture: digital screening for eye disease.

The purpose of this study was to explore progress, in the adaptation to community screening for blinding eye disease, of digital imaging devices and technology for storage and transmission. Available imaging systems were compared to gold standard clinical photography in terms of sensitivity and specificity for diagnosis of common blinding eye conditions. Since the use of expensive non-portable imaging devices is likely to be limited for widespread community screening purposes, a portable fundus camera (Nidek, Chiyoda-ku, Japan) and a prototype monocular digital indirect ophthalmoscope constructed at the Lions Eye Institute (LEI) were selected for comparative trials for the screening of optic disc cupping, glaucoma and clinical signs of diabetic retinopathy. Fifty-one eyes of 27 consecutive patients being assessed at the LEI clinic for glaucoma were dilated and photographed with a Zeiss retinal camera, and digital images were taken with the portable Nidek NM100 fundus camera (Carl Zeiss, Oberkochen, Germany) or with a prototype digital monocular indirect ophthalmoscope. Vertical cup: disc ratios (VCDR) were measured on the disc photographs by one ophthalmologist while three other clinicians were presented with compressed digital images in random order to estimate VCDR. Field trials were also carried out to demonstrate the practicality of compression, local storage and then transmission by mobile telephone ISDN lines and satellite, of optic discs and fundus images of patients with diabetes in either rural Western Australia or Surabaya, Indonesia. Kappa values of correlations of measurement of agreement between measured and estimated VCDR were 0.87, 0.45 and 0.84, respectively, for the three observers, corresponding to a specificity of 79-97% and a sensitivity of 70-95%. The portable Nidek fundus camera was also assessed for specificity and sensitivity in the diagnosis of diabetic retinopathy in comparison to standard Zeiss fundus camera photographs. Of 49 eyes in 25 consecutive patients attending the LEI clinic for assessment of diabetic retinopathy, three ophthalmologists assessed photographs and images in random order. When used for screening diabetic retinopathy, the digital images of the Nidek camera were graded as adequate quality in only 56% of eyes compared to 93% of the photographs. The kappa value of agreement in analysis of diabetic retinopathy was only 0.30. The prototype digital monocular indirect ophthalmoscope compared favourably with the Nidek camera. At 1:5 compression, images of size 36 kB transmitted from Surabaya to Perth took 29 s on the mobile telephone, while uncompressed images took 170 s. Images compressed 1:5 were transmitted in 60 s using the satellite telephone, while the uncompressed images took 240 s. Satellite transmission was more expensive but the lines were more stable than telephone connections from Indonesia. Digital imaging is becoming a powerful tool for ophthalmology in clinical records, teaching and research, and interoffice diagnostic opinions. It also has enormous potential for community screening for blinding eye diseases, such as glaucoma and diabetic retinopathy. Inexpensive portable imaging devices that are easy to use, and on which local health workers might be trained, must be developed and validated in terms of sensitivity and specificity of performance. The technology of image capture, image compression, transmission, data base storage and analysis is rapidly evolving and becoming less expensive.

Diabetic Retinopathy↗
PubMed1999

Age-of-acquisition and frequency effects in speeded word naming.

An experiment was conducted to assess the importance of age-of-acquisition and frequency in a speeded word naming task, where participants were instructed to read aloud words before they disappeared from the computer screen. Under such speeded naming instructions, reading latencies were over 100ms (or 20%) faster than in "standard" (or immediate) word naming. There were clear effects of word frequency and age-of-acquisition under speeded naming. Compared to standard immediate naming, the age-of-acquisition effect was larger, with early-acquired words being speeded up more than late-acquired words, which is interpreted in terms of speeded naming reducing the contribution of sublexical processing to word naming times.

Adult↗
PubMed1999

Progression of myelinated retinal nerve fibers.

PURPOSE: To present a case demonstrating progression of retinal nerve fiber myelin and to suggest that myelinated retinal nerve fibers be considered among the peripapillary choristomas. METHOD: Case report. A 46-year-old woman demonstrated progression of myelinated retinal nerve fibers and associated retinal vascular anomalies. RESULTS: Myelinated retinal nerve fibers can be progressive. We confirm earlier reports of vascular anomalies associated with retinal nerve fiber myelin and show that they can also be progressive. CONCLUSIONS: The rarely progressive nature of myelinated retinal nerve fibers and the histopathologic studies published to date suggest that myelinated retinal nerve fibers represent a striking ophthalmoscopic feature resulting from ectopic oligodendrocytes; thus, the entity may be described as an oligodendrocytic choristoma.

Choristoma↗
PubMed1999

Postoperative deposits on the Acrysof intraocular lens.

PURPOSE: To report a commonly occurring change on the anterior surface of the Acrysof intraocular lens which is presumed to be due to the proliferation of lens epithelial cells from the capsulo-rhexis margin. METHOD: Forty-one consecutive cases (31 patients) of Acrysof intraocular lens implantation were followed prospectively. Clinical charts were reviewed for changes on or within the lens and visual acuity and refractive changes recorded. All cases were dilated at 3-5 weeks postoperatively to facilitate observation of changes. Representative slit lamp photos were taken. RESULTS: Deposits on the intraocular lens surface were noted on 18 of 41 lenses at 3-5 weeks post surgery. Deposits were not found on examinations conducted during the first postoperative week. All changes had fully resolved by 3 months. CONCLUSIONS: The changes recorded had no impact on visual acuity. The deposits noted do not represent clinically important pathology. They may be an unusual marker of biocompatibility with this lens. Surgeons using this lens should be aware of these changes.

Biofilms↗
PubMed1999

Age of acquisition, word frequency, and the role of phonology in the lexical decision task.

In five experiments, we examined the respective roles of word age of acquisition (AoA) and frequency in the lexical decision task. The two variables were manipulated orthogonally (while controlling for concreteness and length) in fully factorial designs. Experiment 1 was a conventional lexical decision task, and Experiments 2-5 involved various attempts to interfere with reliance upon phonology. In Experiment 2, only orthographically illegal nonwords were used; in Experiment 3, pseudohomophone nonwords; in Experiment 4, articulatory suppression by the recitation of a nursery rhyme; and in Experiment 5, articulatory suppression by the repetition of a single word. The same basic pattern of results was observed in all experiments: There were main effects of both AoA and frequency, which interacted in such a way that the AoA effect was larger for low- than for high-frequency words. Although the AoA effect was reduced by manipulations intended to interfere with phonological processing, the manipulations did not eliminate the effect. The results are discussed in terms of current models of reading in which it is proposed that AoA has its primary effect on the retrieval of lexical phonology, which appears to be consulted automatically in the lexical decision task.

Adult↗
PubMed1998

Determination of thyreostat residues from bovine matrices using high-performance liquid chromatography.

High-performance liquid chromatography (HPLC) methodologies were evaluated for the detection and quantification of thyreostatic drug residues in cattle serum and thyroid tissue. The paper details a protocol, using a simple ethyl acetate extraction for the determination of thiouracil, tapazole, methyl thiouracil, propyl thiouracil and phenyl thiouracil in thyroid tissue. Using two sequential HPLC injections, and quantitative analysis, in two steps, all five thyreostats were detectable at concentrations greater than 2.45-4.52 ng/g. Modifications to a published method for detection of thyreostatic residues in serum involving the addition of mercaptoethanol and a freezing step are described. The modifications improved sensitivity and allowed detection of the five thyreostats at levels greater than 16.98-35.25 ng/ml. Young bulls were treated with thyreostats to demonstrate the validity of the methodologies described. Administered thyreostats were not absorbed equally by the test animals and the compounds were not all detected in the serum samples removed at 7 days following drug withdrawal. These experiments indicate the necessity to be able to detect thyreostat residues in a variety of matrices.

Animals↗
PubMed1998

Non-mydriatic fundus photography: a viable alternative to fundoscopy for identification of diabetic retinopathy in an Aboriginal population in rural Western Australia?

PURPOSE: To evaluate the Canon CR5-45NM non-mydriatic fundus camera (Canon, Kanagawa, Japan) for identifying retinopathy and the need for laser treatment in a population of Aboriginal patients with diabetes mellitus in rural Western Australia. METHODS: Diabetic Aboriginal patients were photographed through undilated pupils using a Canon CR5-45NM non-mydriatic fundus camera, after which ophthalmoscopy was performed using indirect ophthalmoscopy through dilated pupils. The examining ophthalmologist recorded the presence of retinopathy and the need for laser treatment. A proportion of patients were rephotographed through dilated pupils. Photographs were reviewed by a second ophthalmologist who evaluated the quality of the image, the presence of retinopathy and the need for laser treatment. Results of fundus photographs and ophthalmoscopy were compared. RESULTS: Three hundred and twenty-eight eyes in 164 Aboriginal patients were examined. The mean patient age was 48.2 years (range 16-81 years) and the mean duration of diabetes was 7.5 years (range 1-35 years). Seventy-four eyes (22.6%) were diagnosed with retinopathy using combined examination techniques, 44 (59.5%) of which were identified by ophthalmoscopy and 55 (74.3%) by photography. Thirty-five eyes were deemed to need treatment, 18 (51.4%) of which were identified by ophthalmoscopy and 30 (85.7%) by photography. Kappa coefficient measurement for agreement for presence of retinopathy and need for referral was 0.41 and 0.53, respectively. Photograph quality was significantly improved following pupil dilation. CONCLUSIONS: The Canon CR5-45NM non-mydriatic fundus camera was relatively good at identifying diabetic retinopathy and could usefully be applied within a screening programme for treatable disease within this population.

Adolescent↗
PubMed1997

Transport and localization elements in myelin basic protein mRNA.

Myelin basic protein (MBP) mRNA is localized to myelin produced by oligodendrocytes of the central nervous system. MBP mRNA microinjected into oligodendrocytes in primary culture is assembled into granules in the perikaryon, transported along the processes, and localized to the myelin compartment. In this work, microinjection of various deleted and chimeric RNAs was used to delineate regions in MBP mRNA that are required for transport and localization in oligodendrocytes. The results indicate that transport requires a 21-nucleotide sequence, termed the RNA transport signal (RTS), in the 3' UTR of MBP mRNA. Homologous sequences are present in several other localized mRNAs, suggesting that the RTS represents a general transport signal in a variety of different cell types. Insertion of the RTS from MBP mRNA into nontransported mRNAs, causes the RNA to be transported to the oligodendrocyte processes. Localization of mRNA to the myelin compartment requires an additional element, termed the RNA localization region (RLR), contained between nucleotide 1,130 and 1, 473 in the 3' UTR of MBP mRNA. Computer analysis predicts that this region contains a stable secondary structure. If the coding region of the mRNA is deleted, the RLR is no longer required for localization, and the region between nucleotide 667 and 953, containing the RTS, is sufficient for both RNA transport and localization. Thus, localization of coding RNA is RLR dependent, and localization of noncoding RNA is RLR independent, suggesting that they are localized by different pathways.

Actins↗
PubMed1997

Reliability of physical performance measures in nursing home residents with Alzheimer's disease.

BACKGROUND: Investigation of the effects of exercise on frail, institutionalized individuals with dementia has been impeded by concerns about the reliability of physical performance measures when used in this population. METHODS: The physical performance of 33 institutionalized subjects with Alzheimer's disease was measured during both the morning and afternoon of day 1 by rater 1 and during both the morning and afternoon of day 2, one week later, by rater 1 and rater 2. Intraclass correlation coefficients (ICCs) were calculated to examine the inter- and intrarater reliability of "sit to stand," "25-foot walk," and "the distance walked in 6 minutes" and walking speed over 25 feet and for 6 minutes. An analysis of variance was performed to determine the components of variance for each test. RESULTS: ICCs for "distance walked in 6 minutes" ranged from .80 to .99 with 77% of the variance explained by inter-subject difference. The ICCs for "time to walk 25 feet" ranged from .57 to .97 with 25% of the variance explained by inter-subject differences. In contrast, the "sit to stand" measure produced ICCs ranging from -.07 to .85 with only 7% of the variance explained by inter-subject differences in this impaired population. CONCLUSION: Our results support the contention that some physical performance measures can be used to test individuals in the later stages of Alzheimer's disease given appropriate modification. Although subjects with Alzheimer's disease may have difficulty following commands and/or require physical assistance, this does not prohibit the reliable assessment of physical performance if measurements are made over longer (6-minute walk) rather than shorter periods (25-foot walk).

Aged↗
PubMed1996

A computer filtering method to drive out tiny genes from the yeast genome.

The authors of the first yeast chromosome sequence defined a minimum threshold requirement of 100 codons, above which an open reading frame (ORF) is retained as a putative coding sequence. However, at least 58 yeast genes shorter than 100 codons have an assigned protein function. Therefore, the yeast genome may contain other tiny but functionally important genes that are discarded from analyses by this simple filtering rule. We have established discriminant functions from the in-phase hexamer frequencies of functional genes and of simulated ORFs derived from a stationary Markov chain model. Fifty-two out of the 58 genes were recognized as coding ORFs by our discriminating method. The test was also applied to all the small ORFs (36 to 100 codons) found in the intergenic regions of published chromosomes. It retained 140 new potential tiny coding sequences, among which we identified seven new genes by similarity searches. Our method, used conjointly with similarity searches, can also highlight sequencing errors resulting from the disruption of the coding frame of longer ORFs. This method, by its ability to detect potential coding ORFs, can be a very useful tool for functional analysis.

Base Sequence↗