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Biomedical subjects

A Cook

Publications and source records attributed to A Cook.

At least 55 records · Page 3Linked to original sources

Immuno-localisation of tumour necrosis factor and its receptors in temporal arteritis.

Temporal arteritis (TA) is an acute vasculitis characterised by destruction of arterial architecture following infiltration of the arterial wall by macrophages, giant cells and lymphocytes. Using immunohistochemical techniques, tumour necrosis factor (TNF) was demonstrated in up to 60% of the cells in all areas of inflamed arteries. More cells staining for TNF were detected in the intima and media of inflamed vessels than control uninflamed arteries (P < 0.003 and P < 0.001, respectively). In TA, TNF was localised to giant cells and macrophages, suggesting that its predominant source is from the monocyte lineage, but, occasionally, TNF staining was found in areas infiltrated by T cells. Many endothelial cells also contained TNF, but there were no differences between the number of endothelial cells staining in inflamed and normal blood vessels. Of the two TNF receptors, the p75 receptor was sparsely represented in the inflamed vessels in TA. By comparison, the p55 receptor was widely detected on endothelial cells and infiltrating mononuclear cells close to the internal elastic lamina (IEL). Endothelial cells from normal vessels also stained for both TNF receptors, but normal smooth muscle cells in the vessel media expressed the p55 receptor, indicating that they are capable of responding to locally secreted TNF. Localisation of TNF receptors and TNF in close proximity to the IEL suggests that TNF could be involved in the leucocyte infiltration and arterial wall destruction characteristic of TA.

Biopsy, Needle↗

Clinical responses to ingested fungal alpha-amylase and hemicellulase in persons sensitized to Aspergillus fumigatus?

alpha-Amylase and hemicellulase, derived from culture of Aspergillus species, are commonly added to flour as improvers during baking. Two cases of women occupationally sensitized to alpha-amylase who developed allergic symptoms after eating baked bread have been reported. With a randomized, controlled study design, we have investigated whether similar responses occur in those sensitized to Aspergillus species. Seventeen subjects with positive skin prick tests to Aspergillus fumigatus were studied. Symptomatic and physiologic responses after ingestion of bread baked with alpha-amylase and hemicellulase were compared, in a crossover fashion, with those after ingestion of bread baked without enzymes. No increase in respiratory or other symptoms, lung function, or nonspecific bronchial hyperreactivity was reported after ingestion of the enzyme-containing bread. We conclude that important clinical reactions to alpha-amylase and hemicellulase in baked bread do not frequently occur in those sensitized to Aspergillus species.

Adult↗

Prader-Willi syndrome.

People with Prader-Willi syndrome (PWS) and their families provide a unique challenge to the general practitioner. This article provides an outline of the key information and management issues for general practitioners who care for people with PWS and their families.

Family Practice↗

Reduction of exposure to laboratory animal allergens in the workplace.

OBJECTIVES: Evidence is now accumulating that the prevalence of allergy to laboratory animals is related to the intensity of exposure to animal allergens. Whilst airborne animal allergen concentrations may be influenced by the litter type, cage design and stock density, the effectiveness of methods to reduce personal exposure has not been objectively assessed. METHODS: Air samples were collected at 2 L/min and 180 L/min onto polytetrafluoroethylene (PTFE) filters and the rat urinary aeroallergen (RUA) and mouse urinary aeroallergen (MUA) concentrations were measured by radioallergosorbent test (RAST) inhibition. RESULTS: When 545 mice (11.l mice/m3) were housed in ventilated cages (Thoren Maximiser cage system) operated at positive pressure to the environment, the static MUA concentration (n = 24, median = 0.10 microg/m3) was reduced sevenfold when compared with conventional cage systems (n = 12, median =0.67 microg/m3, P< 0.001). MUA could be further reduced if the ventilated cage system was operated at lower pressure; static samples (n = 1) collected at 180 L/min at negative, ambient and positive pressure registered < 0.003, 0.02 and 0.28 microg/m3, respectively. During cleaning out, the intensity of personal exposure to RUA was apparently reduced twofold when soiled litter was removed by vacuum (n = 17, median = 22.87 microg/m3) when compared with tipping (n = 18, median = 38.15 microg/m3), P = 0.002) although the task took twice as long to perform. The RUA exposure associated with handling rats was'reduced 25-fold when performed in a ventilated cabinet (n = 21, median = 2.67 microg/m3) compared with handling of rats on an open bench (n = 17, median = 54.39 microg/m3, P = 0.0001). CONCLUSIONS: Effective reduction of exposure to animal allergens can now be achieved by the use of ventilated systems both for housing and handling rats and mice providing safety equipment is used correctly. The vacuum removal of soiled litter during the task of cleaning out was less efficient and additional respiratory protection is therefore recommended for this procedure.

Air Pollutants, Occupational↗

The CBP co-activator stimulates E2F1/DP1 activity.

The cell cycle-regulating transcription factors E2F1/DP1 activate genes whose products are required for S phase progression. During most of the G1 phase, E2F1/DP1 activity is repressed by the retinoblastoma gene product RB, which directly contacts the E2F1 activation domain and silences it. The E2F1 activation domain has sequence similarity to the N-terminal activation domain of E1A(12S), which contains binding sites for CBP as well as RB. Here, we present evidence that the CBP protein directly contacts E2F1/DP1 and stimulates its activation capacity. We show that CBP interacts with the activation domain of E2F1 both in vitro and in vivo. Deletion of four residues from the E2F1 activation domain reduces CBP binding as well as transcriptional activation, but still allows the binding of RB and MDM2. This deletion removes residues which are conserved in the N-terminal activation domain of E1A and which are required for the binding of CBP to E1A. When the E1A N-terminus is used as a competitor in squelshing experiments it abolishes CBP-induced activation of E2F1/DP1, whereas an E1A mutant lacking CBP binding ability fails to do so. These results indicate that CBP can act as a coactivator for E2F1 and suggest that CBP recognises a similar motif within the E1A and E2F1 activation domains. The convergence of the RB and CBP pathways on the regulation of E2F1 activity may explain the cooperativity displayed by these proteins in mediating the biological functions of E1A. We propose a model in which E1A activates E2F not only by removing the RB repression but also by providing the CBP co-activator.

Amino Acid Sequence↗

Fruit and vegetable intakes of children and adolescents in the United States.

OBJECTIVES: To identify the ways in which fruits and vegetables are consumed by children, to provide estimates of their intakes compared with recommendations, and to estimate the percentage of children meeting those recommendations. DESIGN: We examined 3 days of dietary data from respondents in the US Department of Agriculture's 1989-1991 Continuing Survey of Food Intakes by Individuals. All foods reported in the survey were disaggregated into their component ingredients; all fruit and vegetable ingredients were assigned specific weights to correspond with a serving as defined by current dietary guidance materials; and the number of servings of each fruit and vegetable was tallied. PARTICIPANTS: A total of 3148 children and adolescents aged 2 to 18 years in the 48 conterminous United States. MAIN OUTCOME MEASURES: Percentages of fruit and vegetable servings consumed in various forms, mean number of servings consumed per day, and percentage of persons meeting various recommendations by sex/age, race/ethnicity, and household income. RESULTS: Nearly one quarter of all vegetables consumed by children and adolescents were french fries. Their intakes of all fruits and of dark green and/or deep yellow vegetables were very low compared with recommendations. Only one in five children consumed five or more servings of fruits and vegetables per day. CONCLUSION: Pediatricians should encourage the consumption of fruits and vegetables, especially dark green and deep yellow vegetables, by children.

Adolescent↗

Clinical and histologic evaluation of psoriatic plaques treated with a flashlamp pulsed dye laser.

BACKGROUND: Psoriatic plaques can be cleared by destruction of the dermal papillae. Dilated vessels, the major component of psoriatic dermal papillae, can be selectively destroyed with yellow light lasers. Previous investigators have demonstrated partial clearing of psoriatic plaques after treatment with a pulsed dye laser (PDL) (585 nm). OBJECTIVE: This study was designed to examine the clinical and histologic events of psoriasis treated with the PDL. METHODS: Psoriatic plaques were treated with a short (450 microseconds) and long (1500 microseconds) pulse-width PDL. Photographs of the plaques were used for clinical assessment. Biopsy specimens were examined microscopically. RESULTS: Significant clinical improvement was seen, and no significant difference between the long and short pulse-width lasers was found. Patients responding to treatment with the PDL remained in remission for up to 13 months. Histologic normalization occurred after treatment. Two pretreatment vascular patterns were seen: vertically oriented vessels with few horizontal vessels and numerous tortuous vessels. Tortuous vessels were associated with poor clinical results. CONCLUSION: The PDL can induce prolonged remission in chronic plaque psoriasis. The vascular pattern may help to distinguish those patients likely to respond to this treatment.

Adult↗

The significance of echogenic foci in the fetal heart: a prospective study of 228 cases.

The purpose of this study was to determine the pathological significance of echogenic foci in the heart of fetuses with no other sonographic abnormalities and in the absence of other risk factors for chromosomal abnormality. A total of 228 fetuses were identified with single or multiple echogenic foci. This represents 6.9% of the total number of fetuses scanned. The most frequent finding was a single echogenic focus in the left ventricle (n = 136; 60%) but multiple foci were observed in 33%. An echogenic focus in the right ventricle occurred in 16 cases (7%). Karyotypic abnormalities were diagnosed postnatally in two fetuses. One of these fetuses, with an echogenic focus in each ventricle, had trisomy 21, and the other, with two echogenic foci in the left ventricle, had an unbalanced translocation. The vast majority of fetuses which had echogenic foci were normal, but there was a risk of karyotypic abnormality of 1%.

Adult↗

Evaluation of three-dimensional ultrasonography and magnetic resonance imaging in assessment of congenital heart anomalies in fetal cardiac specimens.

In this observational study, multiplanar three-dimensional ultrasound images were reconstructed from tomographic views obtained by scanning seven cadavaric fetal hearts with various congenital heart defects. Comparisons were made with multiplanar three-dimensional magnetic resonance imaging (MRI) of the hearts. Good-quality echocardiographic images were obtained in all but one of the fetal hearts. Multiplanar as well as three-dimensional reconstructions were possible and allowed accurate assessment of complex cardiac defects. Overall, the MRI projections had better image quality and revealed more structural details than the sonographic views, although both imaging modes showed the same cardiac anatomical abnormalities. Our initial results demonstrate that simultaneous multiplanar display of cross-sectional echocardiographic views can be performed to provide three-dimensional images of the fetal heart, demonstrating structural cardiac malformation. However, the clinical application of three-dimensional fetal echocardiography is at present limited by the time required for image data acquisition and the need for accurate temporal and positional gating in the living fetus.

Autopsy↗

Isomerism of the atrial appendages associated with 22q11 deletion in a fetus.

There is a strong association between prenatally diagnosed structural heart disease and fetal chromosomal abnormalities. Isomerism of the atrial appendages is an exception to this because the fetal karyotype is usually normal in this condition. A case of atrial isomerism diagnosed antenatally with a normal female karyotype but with a microdeletion of chromosome 22q11 is reported.

Adult↗

Ontogeny of feeding morphology and kinematics in juvenile fishes: a case study of the cottid fish Clinocottus analis

The development of feeding morphology, kinematics and behavior was examined in the juveniles of the cottid fish Clinocottus analis. The attacks of 18 juvenile C. analis, between 17.59 mm and 42.15 mm in standard length (SL), feeding on brown worms were filmed using high-speed video. Feeding mode, ram- or suction-dominated, kinematic variables and morphology were quantified and compared over the juvenile period. The analysis of these three factors was based on the following questions: (1) do they change over ontogeny; (2) how do their values compare with those of larvae, juveniles and adults of other species; and (3) what is the level of stereotypy, as measured by the variance in these factors, at this stage in ontogeny and does it change? Small C. analis juveniles have the small gape and large buccal cavity of a suction feeder, and this morphology becomes more pronounced as they become larger. The kinematic variables of C. analis juveniles are similar to those of adult suction-feeding cottids and least-squares regression analysis showed significant changes in only two variables (time to prey capture and absolute attack predator&shy;prey distance) over the juvenile period. Feeding mode, as measured by the ram-suction index, shows an increase in the suction component of the strike with increasing size. This study demonstrates that, in C. analis, suction feeding behavior develops during the juvenile period. Within the juvenile stage, morphology, prey-capture kinematics and feeding mode are not tightly linked ontogenetically such that suction-feeder kinematics (short predator&shy;prey distance and low attack velocity) and basic morphology (small gape, large buccal volume) develop much earlier than the employment of a large suction component during the strike.

Journal Article↗

Reflective intuition: defining A&E nursing.

A&E nurses may develop intuitive feelings about the condition of their patients. A&E nurses are practising reflective intuition, based on experience. Recognition of this skill could raise the professional status of nursing.

Clinical Competence↗

Lack of autoantibody expression in children born to mothers with silicone breast implants.

OBJECTIVE: We determined systematically the prevalence of autoantibodies in children born to mothers with silicone breast implants and the relationships with clinical symptoms and methods of exposure. METHODS: Autoantibody expression was determined in 80 children born to mothers with silicone implants and in 42 controls. A clinical assessment score was assigned to each patient. Antinuclear antibodies as well as antibodies to mitochondrial, smooth muscle, striational, myocardial, parietal cell, reticulin tissues, or subcellular compartments were measured by indirect fluorescent assay. Antibodies to nRNP (U1-RNP/snRNP); Sm; SS-A; SS-B; Scl-70; thyroid microsome; immunoglobulin (Ig)G, IgM, and IgA antibodies to cardiolipin; and antibodies to native and denatured human types I and II collagen were measured by enzyme-linked immunosorbent assay. Serum complement components C3 and C4 and IgM rheumatoid factor were measured by nephelometry. RESULTS: Autoantibody prevalence was not significantly different between children born to mothers with silicone implants and controls. The presence of autoantibodies was not related to the children's clinical symptoms or to the method of exposure. CONCLUSIONS: Determination of autoantibody production is of limited clinical utility in the evaluation of children born to mothers with silicone breast implants.

Adolescent↗