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Biomedical subjects

B Brown

Publications and source records attributed to B Brown.

At least 37 records · Page 2Linked to original sources
PubMed2002

'Like a friend going round': reducing the stigma attached to mental healthcare in rural communities.

Traditionally, stigma is seen as something that is the fault of the mental health system, and that involves an individual suffering social disapprobation and reduced life chances as a result of having been given a diagnostic label and an identity as a patient as a result of their contact with psychiatric institutions. The present study, based on focus group discussions conducted with users and mental healthcare workers in a rural setting, suggests that this classic conception of stigma does not readily apply to care in the community. First, workers described themselves as actively trying to challenge stigma at an institutional level, as well as being apt to change their own practice to reduce the stigmatizing effect of mental healthcare on their clients and make their presence less conspicuous. The ideal was to be 'like a friend going round'. However, this view included a somewhat passive notion of clients. By contrast, the present investigation showed that clients described themselves in much more active terms as being aware of possible sources of stigma and being inclined to challenge negative attitudes themselves. Future mental healthcare practice could draw upon professionals' stock of knowledge as to how their practice could lead to less stigma and could build upon clients' own strengths to achieve stigma reduction.

Attitude of Health Personnel↗
PubMed2002

The effect of light scattering on multifocal electroretinography.

PURPOSE: Unclear ocular media is a very common condition of older eyes characterized by significant light scattering and image degradation. The multifocal electroretinography (MERG) is a useful objective technique to measure retinal activity but its validity in the presence of cloudy ocular media remains unclear. We tested the MERG under controlled light scattering conditions using a liquid crystal diffuser (LCD) that simulated different degrees of image degradation. METHODS: The MERG were taken from 13 normal young subjects seated behind a LCD set under two conditions: scatter (visual acuity approximately 6/18) and non-scatter (visual acuity approximately6/6). The pupils had been dilated and the eyes were optically corrected for the working distance. The first-order kernel MERG response was analysed. Three subjects underwent MERG measurement with two additional intermediate light scattering levels (i.e. visual acuity approximately 6/9 and 6/12). RESULTS: The macular MERG response density was reduced (p < 0.001), but the peripheral MERG response densities were increased (p < 0.001) under the scattering condition. A similar trend was also observed with intermediate degrees of light scattering. Comparing the MERG waveforms without light scattering, a new retinal response was identified with a characteristic latency of about 60 ms (P60), but it was diminished in size under the scattering conditions. CONCLUSIONS: The veiling luminance might have caused the reduction in the macular MERG response and an elevation in the peripheral retina with light scatter. The functional suppression of P60 observed under the influence of light scatter may be related to retinal adaptation. Unclear optical media will affect the interpretation of MERG results.

Adolescent↗
PubMed2002

Effect of using prismatic eye lenses on the posture of patients with adolescent idiopathic scoliosis measured by 3-d motion analysis.

This is a preliminary investigation to detect the body sway and postural changes of patients with AIS under different spatial images. Two pairs of low-power prismatic eye lenses (Fresnel prisms) with 5 dioptre and 10 dioptre were used. In the experiment, the apices of the prisms were orientated randomly at every 22.5 degrees from 0 degrees to 360 degrees to test changes. Four patients with mean age of 11 and Cobb's angle of 30 degrees were recruited and the results showed that the low-power prisms at specific orientations (157.5 degrees and 180 degrees) could cause positive postural changes (2.1 degrees-2.7 degrees reduction of angle of trunk mis-alignment) measured by 3-D motion analysis. This might be used for controlling their scoliotic curves by induced visual bio-feedback. Apart from this laboratory test, a longitudinal study is necessary to investigate the long-term effect of the prisms at different powers and orientations (under both static and dynamic situations) on the patient's posture, spinal muscular activities, vision, eye-hand coordination, psychological state and other daily activities before it becomes an alternative management of AIS.

Adolescent↗
PubMed2002

A profile of an HIV-and child-specific programme in New Orleans, Louisiana, USA.

Since the beginning of the AIDS epidemic, 4.3 million children under 15 years of age have been infected with HIV worldwide; in the year 2000 alone, the World Health Organization estimates that 600,000 children became HIV-infected. Ancillary services offer the potential to improve access to and retention in primary care through removal of barriers to care. Globally, ancillary services may actually represent a significant proportion of all care delivered to HIV-infected children, particularly in the absence of expensive antiretroviral treatments. The purpose of this non-concurrent cohort study was to describe a population of HIV-infected children receiving ancillary services from an HIV- and family-specific ancillary service programme in New Orleans, Louisiana, USA. Forty-two HIV-infected children ages newborn to 13 years were included in the study. The majority were between one and five years of age (50.0%), male (54.8%), African-American (88.1%), and perinatally infected (97.6%). Services were well utilized; delivery decreased with age and increased with severity of clinical disease. Improved retention, prescription of antiretroviral treatment and HIV-related emergency room utilization were associated with ancillary service receipt. Ancillary services delivered by an HIV- and family-specific programme assist HIV-infected children to receive improved medical care. Ancillary services are a valuable adjunct to primary care, particularly in the complex care of the HIV-infected children from historically underserved populations.

Case Management↗
PubMed2001

The effect of tobacco smoke, nicotine, and cotinine on the mutagenicity of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL).

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a rodent carcinogen that is metabolically derived from carbonyl reduction of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). NNAL can be pyridine N-oxidized to form NNAL-N-oxide, or conjugated to form NNAL-glucuronide - non-genotoxic metabolites that can be excreted in urine. Alternatively, NNAL can be alpha-hydroxylated at the methyl and methylene carbons adjacent to the nitroso group to generate electrophiles that can react with biological macromolecules, such as DNA and proteins. Our laboratory has previously demonstrated that the mutagenicity of NNK was significantly inhibited by the aqueous extract of tobacco smoke, as well as pyridine alkaloids in cigarette smoke, such as nicotine, cotinine and nornicotine. Given the structural similarity between NNK and NNAL, and the metabolic activation of both by cytochromes P450, we hypothesized that there may be a similar inhibition of NNAL metabolism, and consequently, inhibition of the mutagenic activity of NNAL by tobacco smoke and its pyridine alkaloid constituents. In the present study, we evaluated the ability of two pyridine alkaloids (nicotine and cotinine) and aqueous cigarette smoke condensate extract (ACTE) to inhibit the mutagenicity of NNAL in Salmonella typhimurium strain TA1535 in the presence of a metabolic activation system (S9). Both pyridine alkaloids tested, as well as ACTE, inhibited the mutagenicity of NNAL in a concentration-dependent manner. The observed reductions in mutagenicity were not the result of cell killing due to cytotoxicity. These results demonstrate that tobacco smoke contains pyridine alkaloids, as well as other unidentified constituents that inhibit the mutagenicity of NNAL, a major metabolite of NNK.

Carcinogens↗
PubMed2001

New hominids from the Lake Turkana Basin, Kenya.

New hominid fossils from the Lake Turkana Basin range in age from ca. 3.35 to ca. 1.0 Ma. Those recovered from sediments stratigraphically just above the Tulu Bor Tuff in the Lomekwi Member of the Nachukui Formation are best attributed to Australopithecus afarensis. This species is rare in Kenya, probably because of the scarcity of sediments deposited during its time span. Younger specimens are referable either to the megadont A. boisei or early Homo. Collectively the new fossils promote further understanding of morphological variation in East African Plio-Pleistocene hominids.

Animals↗
PubMed2001

Promoting patient safety through preoperative patient verification.

At Spectrum Health, Grand Rapids, Mich, a process to verify patient identification, procedure, and procedure side and site was developed and implemented to improve the current process. Focusing on risk-reduction strategies, an interdisciplinary task force revised the facility's surgical site identification policy and improved the surgical scheduling form to highlight information for sided procedures. Task force members also designed a verification checklist to require the comparison of any procedure data to the physician's order. This article describes these improvements and other methods that were established to ensure patient safety and reduce risk. Ongoing data collection verifies that the process remains in place and that team members are compliant. The improved process maximizes patient safety because it allows for early intervention when any discrepancies are identified.

Forms and Records Control↗
PubMed2001

Contour interaction in amblyopia: scale selection.

It has been known for some time that visual acuity in amblyopia is higher for single letters than for letters in a row (termed crowding). Early work showed that this could not be accounted for on the basis of the destructive interaction of adjacent contours (termed contour interaction), which was shown to be, in resolution units, normal in amblyopia. We have re-examined this issue using a letter stimulus that is modulated about a mean light level. This allows an examination of the effects of contrast polarity and spatial filtering within the contour interaction paradigm. We show that the majority of strabismic amblyopes that we investigated exhibit an anomalous contour interaction that, in some cases, was dependent on the contrast polarity of the flanking stimuli. Furthermore, we show that while amblyopes do select the optimum scale of analysis for unflanked stimuli, they do not select the optimum scale of analysis for flanked stimuli. For reasons that may have to do with their poorer shape discrimination, they select a non-optimal scale to process flanked stimuli.

Adolescent↗
PubMed2001

Effectiveness of audio-biofeedback in postural training for adolescent idiopathic scoliosis patients.

The possibility of using learned physiological responses in control of progressive adolescent idiopathic scoliosis (AIS) was investigated. Sixteen (16) AIS patients with progressing or high-risk curves (Cobb's angle between 25 degrees and 35 degrees at start and reducible by lateral bending) were fitted with a device with tone alarm for poor posture. In the first 18 months of application, 3 patients defaulted and 4 showed curve progression > 10 degrees (2 changed to rigid spinal orthoses and 2 underwent surgery). The curves for the other 9 patients were kept under control (within +/- 5 degrees of Cobb's angle) and 5 of them have reached skeletal maturity and terminated the application. The remaining 4 patients were still using the devices until skeletal maturity or curve progression. The curve control rate was 69%. A long-lasting active spinal control could be achieved through the patient's own spinal muscles. Nevertheless, before the postural training device could become a treatment modality, a long-term study for more AIS patients was necessary. This project is ongoing in the Duchess of Kent Children's Hospital, Sandy Bay, Hong Kong.

Adolescent↗
PubMed2001

Whole blood microvolume laser scanning cytometry for monitoring resting and activated platelets.

Enumerating and phenotyping of platelets, resting and activated, from whole blood is important for both the identification and verification of many disease states. Microvolume laser scanning cytometry (MLSC) has been shown to be a simple method for enumerating and phenotyping peripheral blood cells. Here, the utility of MLSC, in conjunction with an anticoagulant containing platelet activation inhibitors, for simultaneously measuring platelet count, phenotype and responsiveness directly from non-fixed whole blood was examined. CTAD or EDTA anticoagulated blood was collected from five to 20 healthy volunteers, stained with fluorescence-labeled antibodies specific for platelet antigens, and run on an in-house modified MSLC device. MLSC was able to measure antigens CD9, CD29, CD36, CD41, CD42a, CD42b, and CD61 on platelets and determine an average of 2.3 x 10(5) +/- 7 x 10(4) platelets per microliter. Counts correlated well with those obtained from the Cell-Dyn 3500 (r(2)=0.84). Agreeing with previous data, less than 2% of platelets from peripheral blood of normal individuals expressed the activation markers CD62P or CD63. After in vitro thrombin activation, >93% of the platelets expressed activation markers. Data presented here shows the benefits of using MLSC in combination with platelet inhibitors to quantitate and phenotype platelets while maintaining a viable responsive state.

Anticoagulants↗
PubMed2001

Association between ancillary services and clinical and behavioral outcomes among HIV-infected women.

The purpose of this study was to evaluate the association between ancillary services, including case management, and clinical and behavioral outcomes for human immunodeficiency virus (HIV)-infected women. Data were obtained from databases systematically maintained by Family Advocacy, Care and Education Services (FACES) and the HIV Outpatient Program (HOP) in New Orleans. HIV-infected women receiving primary care from HOP and ancillary services from FACES between January 1, 1997 and December 31, 1998 were eligible. Data were analyzed using generalized estimating equations (GEE) with STATA software. The majority of women included in the study were African American (86.7%), infected heterosexually (78.8%), and had absolute CD4 counts greater than 200 (58.6%). After adjusting for age, time, entry time into HOP, pregnancy, CD4 count, substance abuse status, and social and clinical stressors, receipt of more than four combined case manager contacts or ancillary services per month was significantly associated with being prescribed a protease inhibitor, improved adherence and retention in primary care, and enrolling on a research protocol. Receiving more than one transportation service per month was significantly associated with improved adherence, improved retention, one or more emergency room visits per month, and one or more hospitalizations per month. Receiving more than one contact with case managers per month was associated with improved retention in primary care. Findings suggest that receipt of case management and ancillary services is associated with improvements in multiple outcomes for HIV-infected women. A client-centered approach to providing ancillary services appears to be effective in improving behavioral and utilization characteristics in this population of low-income, high-risk women.

Adolescent↗
PubMed2001

The mere exposure effect in patients with schizophrenia.

The mere exposure effect refers to the development of an emotional preference for previously unfamiliar material because of frequent exposure to that material. This study compared schizophrenia subjects (n = 20) to normal controls (n = 21) to determine whether implicit memory, as demonstrated by the mere exposure effect, was intact. Patients with schizophrenia demonstrated a normal preference for both verbal and visual materials seen earlier relative to novel materials, despite impaired performance on a recognition task for explicit memory using similar materials. Previous studies of schizophrenia subjects have shown a dissociation between implicit and explicit memory on verbal tasks. We found a similar dissociation demonstrated by normal functioning on an implicit memory task and impaired functioning on an explicit memory task. Potential implications of these findings are discussed with regard to treatment and rehabilitation.

Adult↗
PubMed2001

Does mobility performance of visually impaired adults improve immediately after orientation and mobility training?

BACKGROUND: Previous studies that have attempted to determine the effect of orientation and mobility training on mobility performance of visually impaired adults have had a number of limitations. With the inclusion of a control group of subjects, this study investigated the effect of orientation and mobility training on mobility performance of a group of visually impaired adults. METHODS: Vision was measured binocularly as high- and low-contrast visual acuity, letter and edge contrast sensitivity, and Humphrey kinetic visual fields. The subjects' mobility performance was assessed as percentage preferred walking speed (PPWS) and error score before and after mobility training. RESULTS: Orientation and mobility training did not enhance mobility performance compared with the control group, who did not receive training, when performance was measured immediately after training. PPWS improved for both groups with short-term practice only, but there was no improvement in error score due to either practice or training. CONCLUSIONS: There was no immediate improvement in mobility performance of visually impaired adults after orientation and mobility training. Familiarity with the route may play an important role in measured improvement of mobility performance after orientation and mobility training.

Adaptation, Ocular↗
PubMed2001

Variation in vernier evoked cortical potential with age.

PURPOSE: To investigate the effects of age on transient vernier visual evoked potential (VEP) and vernier acuity estimated by extrapolation. METHODS: Transient vernier VEPs were examined in normal subjects aged 20 to 75 years. Vernier offsets were presented for the first 350 msec of the stimulus period, and the segments were then realigned in the following 400 msec. The six vernier offsets used were 20, 40, 60, 80, 100, and 140 seconds of arc. Averaging for each offset setting produced vernier VEP waveforms, for which amplitude and latency of visual evoked response and background electroencephalographic (EEG) noise level were determined. Extrapolation of the function relating signal-to-noise ratio and log vernier offset to a ratio of 1.0 resulted in an estimate of vernier acuity. RESULTS: Amplitude of vernier VEP waveforms was significantly reduced in subjects more than 60 years of age, and the latency to the first negative peak was progressively prolonged with increasing age. There was no statistically significant change in electroencephalographic (EEG) noise with advancing age. VEP vernier acuity was significantly degraded in the 61- to 75-year age group. These results are parallel to recent psychophysical findings that alignment performance is worse in older persons than in younger ones. CONCLUSIONS: The present findings provide the first electrophysiological evidence of age-related cortical degeneration associated with vernier processing. Reduced neural activity probably contributes to the loss of vernier acuity with advancing age. Also provided are the first normative data for subjects of different ages for vernier VEP and VEP vernier acuity. Moreover, the present study has demonstrated that vernier VEP is sensitive to neural changes and therefore may be applied in clinical situations to evaluate the integrity of the visual system.

Adult↗
PubMed2001

The effects of socioeconomic status and increased body mass index on cardiovascular disease in African-American women.

Today within the United States, CVD is the leading cause of death in women with the highest mortality being seen in African-American women. A review of literature revealed that over the last decade, within the United States, there has been an overall reduction in the death rate due to CVD. However, the rate of decline has been less for women than for men and less for African-American women than for White women. Findings from some studies indicate that African-American women have increased risk factors as compared to other ethnic groups for CVD based upon conditions and behaviors affecting lifestyle. Fortunately, most of the CVD risk factors are modifiable and their occurrence can be widely prevented. Therefore, it is imperative that health care providers approach the issue of risk factors for CVD in African-American women as a heart disease epidemic. This approach is necessary if the United States is going to improve the health of all Americans, eliminate disparities, and improve the quality of life.

Black or African American↗