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Biomedical subjects

C Peacock

Publications and source records attributed to C Peacock.

At least 19 recordsLinked to original sources

Mammographic casting-type calcification associated with small screen-detected invasive breast cancers: is this a reliable prognostic indicator?

AIM: The aim of the present study was to establish whether mammographic casting-type calcification associated with small screen-detected invasive breast cancers is a reliable prognostic indicator. METHODS AND MATERIALS: We retrospectively identified 50 consecutive women diagnosed with an invasive cancer less than 15 mm who showed associated casting calcification on their screening mammograms. Controls were identified that showed no microcalcification and were matched for tumour size, histological type and lymph node status. A minimum of 5 years follow-up was obtained, noting recurrence and outcome. Conditional and unconditional logistic regression, depending on the outcome variable, were used to analyse the data, taking the matched design into account in both cases. Where small numbers prohibited the use of logistic regression, Fisher's exact test was used. RESULTS: Five deaths from breast cancer occurred out of the 50 cases, of which three were lymph node positive, two were lymph node negative and none were grade 3. None of the 78 control cases died from breast cancer. The difference in breast cancer death rates was significant by Fisher's exact test (p=0.02). Risk of recurrence was also significantly increased in the casting cases (OR=3.55, 95% CI 1.02-12.33, p=0.046). CONCLUSION: Although the overall outcome for small screen-detected breast cancers is good, our study suggests that casting calcification is a poorer prognostic factor. The advantage of a mammographic feature as an independent prognostic indicator lies in early identification of high-risk patients, allowing optimization of management.

Breast Neoplasms↗

Asbestos-related benign pleural disease.

Benign pleural disease is the commonest manifestation of asbestos exposure encountered by radiologists. Benign pleural thickening can appear as circumscribed parietal pleural plaques or as more diffuse thickening of the visceral pleura. Benign-asbestos induced pleural effusions are a significant and under-recognized manifestation of asbestos exposure with important sequelae, such as diffuse pleural thickening which may be associated with functional impairment and for which compensation may be sought. This review concentrates on the strengths and weaknesses of chest radiography and computed tomography for the detection and characterization of benign asbestos-related pleural disease and the relevance of imaging abnormalities to compensation and functional impairment.Peacock, C. (2000). Clinical Radiology55, 422-432.

Asbestos↗

Leukemia inhibitory factor is synthesized and released by human eosinophils and modulates activation state and chemotaxis.

BACKGROUND: The cytokine leukemia inhibitory factor (LIF) is known to be produced by both inflamed peripheral autonomic nerves and several cell types involved in the regulation of the immune response. We have recently demonstrated that several structural cell types in human airways produce LIF in response to inflammatory stimuli and that LIF augments contractile responses to tachykinins in airway explants. Because the eosinophil is a major effector cell in asthma and often found adjacent to the nerves, we hypothesized that eosinophils produce LIF and that LIF primes and upregulates eosinophil recruitment and function, allowing bidirectional neuroimmune interactions and augmentation of eosinophil-mediated injury. OBJECTIVE: The purpose of this study was to demonstrate that human eosinophils synthesize and release LIF, to determine the effects of LIF on eosinophil functions (ie, chemotaxis, granule protein release, expression of the activation marker CD69, and apoptosis), and to compare serum LIF levels between atopic and nonatopic individuals. METHODS: Reverse-transcription PCR, ELISA, immunocytochemistry, chemotaxis assay, and flow cytometry were used. RESULTS: Peripheral blood eosinophils express LIF and messenger RNA for LIF and LIF receptor. Serum LIF levels were higher in atopic patients with mild asthma than in nonatopic normal donors. Eosinophils from nonatopic donors were stimulated by calcium ionophore to release small amounts of LIF (from almost none to 5.3 +/- 1.8 pg/10(6) cells). Eosinophils from atopic donors showed a 10-fold increase (from 45.1 +/- 38.7 pg/106 cells to 414.5 +/- 189.9 pg/10(6) cells). Preincubation of eosinophils with LIF increased eosinophil peroxidase release 4-fold. LIF was not chemotactic for eosinophils but augmented chemotaxis mediated by substance P by 82% and by platelet-activating factor by 31%. LIF did not effect eosinophil apoptosis but increased CD69 expression. CONCLUSION: LIF has proinflammatory roles in eosinophil-dependent airway disorders.

Antigens, CD↗

Cervical spine movements during laryngoscopy. Comparison of the Macintosh and McCoy laryngoscope blades.

We studied cervical spine movement in 10 patients scheduled for elective surgery under general anaesthesia. Each patient was fitted with a rigid cervical collar before undergoing direct laryngoscopy for orotracheal intubation. Laryngoscopy was performed using the McCoy laryngoscope in the activated position and the standard Macintosh blade. Displacement of the cervical spine at laryngeal exposure was measured using lateral cervical spine X-rays. Flexion and extension movements of the cervical spine during the use of the two laryngoscope blades were compared. For each blade, the greatest degree of extension occurred at the joint between the first and second cervical vertebrae. There was no significant difference in cervical spine movement when the two blades were compared.

Adult↗

Preliminary clinical experience of a contracture correction device.

Joint contractures which do not respond to conventional physiotherapy can be difficult to treat. Serial plastering has been used effectively but is expensive, inconvenient to the patient and does not permit daily hygiene or clinical inspection. A mechanical device has been developed consisting a hinged orthosis which spans the affected joint to which is attached a gas strut to provide a corrective moment about the anatomical joint. Such an arrangement enables prescribed corrective moments to be applied accurately following clinical assessment using routine physiotherapy techniques. The inherently low spring rate of a gas strut ensures that the specified corrective torque is maintained as correction occurs. Initial treatment experience under the control of the developers had generated wider interest in the system. A geographically distant independent orthotic supply centre was trained in the techniques of application. They treated nine elbow and three knee joints in patients who had not responded to physiotherapy treatment. All of the patients experienced improvement. The average for elbow joints was a reduction in the contracture of 25.6 degrees with a corrective moment of 6.8 Nm over a period of 3.9 weeks. For the knee joints the averages were a reduction in contracture of 10.7 degrees with a corrective moment of 12.7 Nm over a period of 4 weeks. The results confirmed the practicality of transferring the system to independent clinical centres and provide evidence to support funding for a formal prospective clinical trial of the treatment approach.

Adult↗

Use of tracheobronchography as a diagnostic tool in ventilator-dependent infants.

OBJECTIVE: Comparison of investigations of the airway in ventilator-dependent infants. DESIGN: Consecutive infants with suspected upper airway abnormalities were investigated using rigid bronchoscopy and tracheobronchography. SETTING: Tertiary pediatric and neonatal intensive care units. PATIENTS: Eight infants with suspected airway abnormalities. INTERVENTIONS: Rigid bronchoscopy and tracheobronchography. MEASUREMENTS AND MAIN RESULTS: Structural abnormalities, segmental narrowing of the airways and the effect of various levels of positive-end expiratory pressures on the narrowings were documented. In six of the eight cases, additional airway abnormalities were diagnosed with tracheobronchography compared with rigid bronchoscopy. CONCLUSIONS: In cases of suspected abnormalities of the upper airway in small infants unable to be weaned from ventilatory support, tracheobronchography may be a more reliable investigation method than rigid bronchoscopy. The ability to assess the structural and dynamic components of the airway accurately and safely allows a correct and long-term treatment plan to be established in this group of patients.

Airway Obstruction↗

A newly described possible complication of lymphangioma circumscriptum.

Lymphangioma circumscriptum is a rare disorder of lymphatic channels, the cause of which is poorly understood. It is an unpleasant, but benign, condition conventionally managed by wide local excision, which provides symptom control and often prevents recurrence. No long term complications and no association with squamous cell carcinoma have been previously documented. We present a 20-year-old patient with lymphangioma circumscriptum involving the vulval and perianal areas, which recurred after surgery and seems to have predisposed to squamous cell carcinoma 11 years after presentation.

Adult↗

Contribution of tuberculosis to slim disease in Africa.

OBJECTIVES: To assess the contribution of tuberculosis to the aetiology of the HIV wasting syndrome (slim) in Africa, a condition usually considered an enteropathy. METHODS: Clinical examination and representative necropsy study of adult patients positive for HIV. SETTING: Hospital medical wards in Abidjan, Ivory Coast. SUBJECTS: Adults positive for HIV. MAIN OUTCOME MEASURES: CD4 T lymphocyte counts before death, clinical and anthropometric data, and gross and microscopic pathology. RESULTS: Necropsy was done on 212 HIV positive adults. Tuberculosis was found in 41 of 93 with the clinical HIV wasting syndrome and in 32 of 119 without (odds ratio 2.1, 95% confidence interval 1.2 to 4.0). A significant association existed between the prevalence of tuberculosis at necropsy and the degree of cadaveric wasting (no wasting 25% (15/59); moderate wasting 40% (23/58); skeletal wasting 44% (42/95); P = 0.02). Wasting was also associated with a history of chronic diarrhoea, but no association existed between diarrhoea and tuberculosis. Median CD4 T lymphocyte counts were lowest in wasted patients irrespective of findings at necropsy and in those with chronic diarrhoea (< 60 x 10(6)/l). CONCLUSION: Wasting and chronic diarrhoea are late stage manifestations of HIV disease in Africa. The importance of tuberculosis as a contributing factor in the pathogenesis of the slim syndrome has been underestimated. In nearly half of patients dying with severe wasting, tuberculosis was the dominant pathological finding.

Adolescent↗

Nocardiosis in HIV-positive patients: an autopsy study in West Africa.

BACKGROUND: There are many reports of nocardiosis associated with HIV infection in industrialized and developing countries, but its true prevalence is unknown. MATERIALS AND METHODS: An autopsy study was performed of HIV-positive and HIV-negative patients dying on the general medical wards of a large hospital in Abidjan, Ivory Coast, in 1991. RESULTS: 247 HIV-positive adult cadavers were examined. 10 (4%) had nocardiosis of the lung, of whom 6 showed disseminated disease. 8 patients had one or more AIDS-defining pathologies, and 5 had nocardiosis as the main cause of death. Pulmonary tuberculosis was found in 87 cadavers (35%), giving a ratio of pulmonary nocardial to tuberculous disease of 1:9. No nocardiosis was seen in 42 HIV-negative cadavers. CONCLUSIONS: This is the highest recorded prevalence of HIV-associated nocardiosis in a representative sample. The prevalence of nocardiosis varies geographically, and in zones where HIV-associated tuberculosis is common, it is possible that some patients diagnosed as smear-negative pulmonary tuberculosis actually have nocardiosis. A revised strategy of sputum examination with gram stain is suggested to detect nocardia.

AIDS-Related Opportunistic Infections↗

The mortality and pathology of HIV infection in a west African city.

BACKGROUND: HIV disease is epidemic in Africa, but associated mortality, underlying pathology and CD4+ T-lymphocyte counts have not previously been evaluated in a representative study. Such data help to determine the management of HIV-positive people. Both HIV-1 and HIV-2 infections are prevalent in Côte d'Ivoire, and the pathology of HIV-2 infection in Africa is unclear. METHODS: Consecutive adult medical admissions to a large city hospital in Côte d'Ivoire were studied in 1991, and a sample of HIV-positive deaths autopsied. RESULTS: Of 5401 patients evaluated, 50% were HIV-positive; 38% of these died, with a median survival of 1 week. At autopsy (n = 294, including 24% of HIV-positive deaths in hospital), tuberculosis (TB), bacteraemia (predominantly Gram-negative rods) and cerebral toxoplasmosis caused 53% of deaths. TB was seen in 54% of cadavers with AIDS-defining pathology and Pneumocystis pneumonia in 4%. The median CD4+ T-lymphocyte counts in those who died was < 90 x 10(6)/l. Compared with HIV-1-positives, patients with HIV-2-positivity had a greater frequency of severe cytomegalovirus infection, HIV encephalitis and cholangitis. CONCLUSIONS: In this population, HIV-positive adults present to hospital with advanced disease associated with high mortality. The three major underlying pathologies (TB, toxoplasmosis and bacteraemia) are either preventable or treatable. TB is an underestimated cause of the 'slim' syndrome in Africa. The patterns of pathology in HIV-2-positive patients suggest a more prolonged terminal course compared with HIV-1. There is an urgent need for attention towards the issues of therapy and care for HIV disease in developing countries.

AIDS-Related Opportunistic Infections↗

International policies on alcohol-impaired driving: a review.

A review is presented of policies to curb alcohol-impaired driving. The principal measure applied against drinking and driving in most industrial countries is the implementation of laws limiting the amount of alcohol which can be legally consumed by a person who subsequently takes charge of a motor vehicle on a public road. This strategy seems to have been the most effective to date, although national variations in legislation, rigor of application, and the extent of public knowledge are reflected in the range of outcomes reported. The effectiveness of "random breath testing" appears to be related to the degree to which drivers believe that the law is enforced. Other strategies aimed at the reduction of drinking and driving are education, publicity, and exhortation; the rehabilitation of convicted offenders; and restrictions on the availability of alcohol. However, due to factors such as the lack of evaluation, or limited scope, or nonspecificity to drinking and driving, these measures appear to have been less successful in curbing alcohol-impaired driving than the application of legal powers.

Alcohol Drinking↗

Expression of LPG and GP63 by different developmental stages of Leishmania major in the sandfly Phlebotomus papatasi.

Development and forward migration of Leishmania parasites in the sandfly gut is accompanied by morphological transformation to highly motile, non-dividing 'metacyclic' forms. Previous studies in vitro have demonstrated that this metacyclogenesis is associated with developmentally regulated changes in expression of two major surface glycoconjugates of Leishmania, the lipophosphoglycan (LPG) and the glycoprotein protease GP63. Studies presented here are the first to examine in situ the changes in expression of these two important surface molecules which occur during amastigote-initiated development of L. major in its natural vector Phlebotomus papatasi. Immunocytochemical analysis using a GP63-specific monoclonal (3.8), and others recognizing metacyclic-specific (3F12) and common (WIC79.3) epitopes of LPG on logarithmic and metacyclic promastigotes, demonstrates: (1) clear expression of LPG and GP63 from 2 and 7 days post-bloodfeeding, respectively; (2) developmental modification of the LPG molecule as parasites undergo forward migration and morphological changes associated with metacyclogenesis; and (3) striking deposition of large amounts of parasite-free excreted LPG on/in the epithelial cells of the gut wall.

Animals↗

Livestock production on Masai group ranches. 2. Growth and liveweight in goats and sheep at Elangata Wuas and the factors influencing them.

In 1101 goats and 547 sheep kept under ranch conditions the liveweight development was measured and compared between their 10th and 550th day of life. Consideration was given to factors such as sex, parity, birth type, season of birth, and flock. Post-partum weights of the dams are given and analysed for the same variables. Management of the flocks is the proximate factor in growth rates and liveweight, but almost all other variables also have significant effects on the weight-for-age. Management is also responsible for the biggest differences in weights in post-partum females, while season had a greater effect on this factor in sheep than in goats.

Age Factors↗

Metabolism of mannitol by Coccidioides immitis.

Lones, George W. (National Institute of Allergy and Infectious Diseases, U.S. Public Health Service, Bethesda, Md.), and Carl Peacock. Metabolism of mannitol by Coccidioides immitis. J. Bacteriol. 87:1114-1117. 1964.-Strain M-11 of Coccidioides immitis was found to utilize mannitol for growth in the mycelial form but not in the spherule form. Cell-free extracts of both forms, grown on glucose, were capable of reducing nicotinamide adenine dinucleotide with mannitol-1-PO(4) but not with mannitol. The extracts accomplished a rapid oxidation of reduced nicotinamide adenine dinucleotide by fructose-6-PO(4), the expected product of mannitol-1-PO(4) oxidation. Fructose was inactive. Paper electrophoresis and chromatography with several solvent systems demonstrated a substance in extracts of both mycelium and spherules having a migration consistent with that of mannitol.

Coccidioides↗

Automatic forensic face recognition from digital images.

Digital image evidence is now widely available from criminal investigations and surveillance operations, often captured by security and surveillance CCTV. This has resulted in a growing demand from law enforcement agencies for automatic person-recognition based on image data. In forensic science, a fundamental requirement for such automatic face recognition is to evaluate the weight that can justifiably be attached to this recognition evidence in a scientific framework. This paper describes a pilot study carried out by the Forensic Science Service (UK) which explores the use of digital facial images in forensic investigation. For the purpose of the experiment a specific software package was chosen (Image Metrics Optasia). The paper does not describe the techniques used by the software to reach its decision of probabilistic matches to facial images, but accepts the output of the software as though it were a 'black box'. In this way, the paper lays a foundation for how face recognition systems can be compared in a forensic framework. The aim of the paper is to explore how reliably and under what conditions digital facial images can be presented in evidence.

Electronic Data Processing↗