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Biomedical subjects

J Ball

Publications and source records attributed to J Ball.

At least 19 recordsLinked to original sources
PubMed2006

Comparative cohort study of the outcomes of deep lamellar keratoplasty and penetrating keratoplasty for keratoconus.

AIM: To compare the outcomes and complications of deep lamellar keratoplasty (DLK) and penetrating keratoplasty (PK) for keratoconus. METHODS: A cohort of 20 consecutive PKs, for keratoconus, was compared with 20 consecutive DLKs, for keratoconus. The PKs were performed between June 2000 and July 2001, the DLKs between October 2001 and October 2002. Surgery was performed by one surgeon. Best-corrected visual acuities (BCVA), refraction and complications were recorded at the time of surgery, 6 and 12 months postoperatively. chi(2)-tests were used to compare visual acuity outcomes and independent t-tests in the analysis of astigmatism. RESULTS: Groups were comparable for age, sex, and ethnicity. All PKs were uncomplicated. Two of the DLK group had microperforations of Descemet's membrane. There was no significant difference in the proportion of patients achieving 6/9 or better between the PK and DLK groups (85 vs 78%, P=0.54). PK patients were, however, more likely than the DLKs to achieve 6/6 at 1 year; 70% (14/20) of PKs compared to 22% of (4/18) DLKs (P=0.04). Astigmatism was significantly higher in the PKs compared to the DLKs (P=0.022). There were two cases of graft rejection in the PK group, while none in the DLKs. CONCLUSIONS: This study confirms good visual results from both PK and DLK in keratoconus with similarly high percentages reaching 6/9 BCVA. DLK appears to cause less astigmatism and also has the advantage of no endothelial graft rejection. The apparent cost, however, is a reduction in the likelihood of achieving 6/6 BCVA.

Adult↗
PubMed2005

First measurement of the transverse spin asymmetries of the deuteron in semi-inclusive deep inelastic scattering.

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins asymmetry turns out to be compatible with zero, as does the measured Sivers asymmetry within the present statistical errors.

Journal Article↗
PubMed2004

An audit of screening for familial breast cancer before 50 years in the South Thames Region - have we got it right?

We have carried out an audit of breast screening by mammography under 50 years of age in a cohort of 192 women attending family cancer clinics run by the South Thames genetic services. Of these women, six came from families in which a BRCA mutation had been identified, 61 had > 50%, 35 a 20-50% and 90 had < 20% chance of carrying a high risk mutation. In the 192 women in the screened cohort, 9 breast cancers were diagnosed (4.7%), all in high-risk women. Three were diagnosed at the prevalence screen. Three were detected mammographically at subsequent screening rounds; three were detected by breast self-examination (BSE) between screening episodes. One interval cancer was visible on mammogram at presentation but not at screening five months previously. A second cancer was also visible on mammogram at presentation but the normal screening mammogram had been 17 months earlier, outside the recommended interval. The remaining interval cancer was not visible on the mammogram. A total of 363 two-view screening mammograms were performed in the 280 person-years of follow-up; 109 additional investigations were generated: 23 recall mammograms, 18 symptomatic mammograms, 45 ultrasounds, 12 aspiration cytologies and 11 biopsies. Cytology diagnosed malignancy in 1 of 12 cases; breast biopsy in 9 of 11 cases. Twenty-three additional women had ultrasound screening only. This audit suggests that screening below the age 50 years may be unnecessary in families with a low chance of having a BRCA1 or -2 mutation, but it is important to screen high-risk women at least annually and possibly under 35 years.

Adult↗
PubMed2004

Do Toxoplasma gondii RH strain tachyzoites evolve during continuous passage?

AIM: To examine three lineages of Toxoplasma gondii RH strain in terms of performance in the dye test, culture, and gene expression. METHODS: Historical data (culture growth and performance in the dye test) from three lineages of RH strain tachyzoites (B, J, and Q) that had been continuously cultured in HeLa cells was assessed. Tachyzoite harvests obtained during continuous cell culture were retrieved from liquid nitrogen and cultured in HeLa cells, providing mRNA that was extracted and used to study gene expression using random amplified polymorphic DNA analysis at different stages of lineage adaptation to continuous culture. RESULTS: The B and Q lineages consistently produced tachyzoites that were successfully used in the dye test and their gene expression was stable after multiple passages. The J lineage had unpredictable growth, tachyzoites unsuitable for use in the dye test, and changing gene expression with multiple passage. CONCLUSION: This study has explained some anomalies in the performance of different stocks of T gondii, and suggests that lineages that are still evolving in cell culture should be avoided.

Animals↗
PubMed2002

Eta photoproduction on the proton for photon energies from 0.75 to 1.95 GeV.

Differential cross sections for gammap-->etap have been measured with tagged real photons for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified by missing mass reconstruction using kinematical information for protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W=1.75 GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass approximately 1.8 GeV couples to the etaN channel.

Journal Article↗
PubMed2002

How useful is the bispectral index in the management of ICU patients?

If you want to objectively quantify the level of sedation the intuitive solution must be to monitor the brain directly. However, due to the complexity of this organ, and our limited understanding of consciousness, this remains a daunting challenge. For many years, researchers have investigated the electrical activity of the brain and its relationship with conscious level. Over the last few years, a derived variable from the EEG, the Bispectral Index (BIS), has been developed, which appears to correlate quite well with the level of pharmacological sedation.

Critical Care↗
PubMed2002

A critique of age estimation using attrition as the sole indicator.

The age determination of skeletal remains has been carried out using anthropological examination of the remaining bones and dentition. The aging of the dentition is based on attrition which, if physiological will correlate with age. Occasionally the only material available is a single tooth or a few teeth, or in the case of a living person, teeth in situ. In certain cases microscopic examination of the teeth may not be possible and the age estimation is then often determined by the degree of attrition associated with the tooth. In more recent times the causes of attrition have involved other factors such as bruxism, diet, environment and medication. The weaknesses and limitations of age estimation by examination of dental attrition as the sole indicator of age are highlighted.

Adolescent↗
PubMed2002

The current status of lip prints and their use for identification.

The use of lip prints for human identification was first suggested in 1950 and research was carried out on lip prints in the 1960s and early 1970s, resuming in the last few years. Although lip print identification has been utilized in court in isolated cases more research needs to be conducted in this field with regard to confirmation of uniqueness, and the collection and interpretation of evidence. Lip print identification needs to be acceptable in court as scientifically evidence based.

Cosmetics↗
PubMed2001

The 21st International Symposium on Intensive Care and Emergency Medicine, Brussels, Belgium, 20-23 March 2001.

The 21st International Symposium on Intensive Care and Emergency Medicine was dominated by the results of recent clinical trials in sepsis and acute respiratory distress syndrome (ARDS). The promise of extracorporeal liver replacement therapy and noninvasive ventilation were other areas of interest. Ethical issues also received attention. Overall, the 'state of the art' lectures, pro/con debates, seminars and tutorials were of a high standard. The meeting was marked by a sense of renewed enthusiasm that positive progress is occurring in intensive care medicine.

Critical Care↗
PubMed2001

Tracking the response of Xid B cells in vivo: TI-2 antigen induces migration and proliferation but Btk is essential for terminal differentiation.

X-linked immunodeficient (Xid) mice carry a Bruton's tyrosine kinase (Btk) mutation and exhibit a selective failure to produce antibodies against bacterial capsular polysaccharides. Studies in vitro point to a fundamental survival defect of Xid B cells after receptor cross-linking by thymus-independent type-2 (TI-2) antigen because B cells undergo apoptosis without proliferating. We describe results from a novel model, which we have used to investigate the impact of the Xid mutation on migration, proliferation and differentiation of B cells after polysaccharide immunization in vivo. Immunoglobulin knock-in mice, in which a large proportion of B cells express transgene-encoded receptors specific for (4-hydroxy-3-nitrophenyl)-acetyl (NP), were crossed with CBA/N mice. The male progeny contain NP-specific Xid B cells, while the female progeny contain NP-specific B cells with normal Btk. After immunization with the TI-2 antigen NP-Ficoll, NP-specific Xid B cells migrate to the T zones and proliferate. Despite transient up-regulation of blimp-1 and survival beyond the time when terminal differentiation is normally underway, Btk-defective B cells fail to differentiate to plasmablasts or germinal center cells. CD40 ligation partially restores their ability to form plasma cells in response to TI-2 antigen.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed2001

Ability of hospitals to care for pediatric emergency patients.

CONTEXT: The needs of children in emergency situations differ from those of adults and require special attention, yet there has been no study of the ability of U.S. hospitals to care for emergently or critically ill children. OBJECTIVE: To estimate the distribution of pediatric services available at U.S. hospitals with emergency departments (EDs). DESIGN: Self-report survey of 101 hospital EDs. PARTICIPANTS: Stratified probability sample of all U.S. hospitals operating EDs. RESULTS: The majority of hospitals that usually admit pediatric patients do not have separate pediatric facilities. Hospitals without a pediatric department, ward, or trauma service usually transfer critically injured pediatric trauma patients; however, nearly 10% of hospitals without pediatric intensive care facilities admit critically injured children to their own facilities. Likewise, 7% of hospitals routinely admit pediatric patients known to require intensive care to their adult intensive care units rather than transferring the patient to a facility with pediatric intensive care facilities. Few hospitals have protocols for obtaining pediatric consultation on pediatric emergencies. Appropriately sized equipment for successful care of infants and children in an emergency situation was more likely to be missing than adult-sized equipment, and significant numbers of hospitals did not have adequate equipment to care for newborn emergencies. CONCLUSION: Emergent and critical care of infants and children may not be well integrated and regionalized within our health care system, suggesting that there is room for improvement in the quality of care for children encountering emergent illness and trauma.

Adult↗
PubMed2001

Are teamwork and professional autonomy compatible, and do they result in improved hospital care?

A postal questionnaire survey of 10 022 staff nurses in 32 hospitals in England was undertaken to explore the relationship between interdisciplinary teamwork and nurse autonomy on patient and nurse outcomes and nurse assessed quality of care. The key variables of nursing autonomy, control over resources, relationship with doctors, emotional exhaustion, and decision making were found to correlate with one another as well as having a relationship with nurse assessed quality of care and nurse satisfaction. Nursing autonomy was positively correlated with better perceptions of the quality of care delivered and higher levels of job satisfaction. Analysis of team working by job characteristics showed a small but significant difference in the level of teamwork between full time and part time nurses. No significant differences were found by type of contract (permanent v short term), speciality of ward/unit, shift length, or job title. Nurses with higher teamwork scores were significantly more likely to be satisfied with their jobs, planned to stay in them, and had lower burnout scores. Higher teamwork scores were associated with higher levels of nurse assessed quality of care, perceived quality improvement over the last year, and confidence that patients could manage their care when discharged. Nurses with higher teamwork scores also exhibited higher levels of autonomy and were more involved in decision making. A strong association was found between teamwork and autonomy; this interaction suggests synergy rather than conflict. Organisations should therefore be encouraged to promote nurse autonomy without fearing that it might undermine teamwork.

Cooperative Behavior↗
PubMed2001

If changing skill mix is the answer, what is the question?

Changing skill mix is often identified as a potential solution to health services staffing and resourcing problems, or is related to health sector reform. This paper discusses what is meant by skill mix, provides a typology of the different approaches to assessing skill mix and examines, by means of case studies, the contextual, political, social and economic factors that play a part in determining skill mix. These factors are examined in relation to three factors: the reasons (or drivers) for examining skill mix; the impact of contextual constraints; and the effect of varying spans of managerial control. Case studies conducted in Costa Rica, Finland, Mexico, the UK and the USA are used to explore the reality of assessing skill in different contexts and health care settings. We argue that, although skill mix may be a universal challenge, it is not a challenge that all managers or health professionals can meet in the same way, or with the same resources. Context can have a significant effect on the ability of health service managers to assess and change skill mix. The key determinant is the extent to which these factors are in the locus of control of management nationally, regionally, or locally, within different countries. We emphasise the need to evaluate the problem and examine the context, before deciding if a change in skill mix is the answer. The local managerial span of control and degree of organisational flexibility will be major factors in determining the likely impact of any attempts to change skill mix. Before embarking on a skill mix review, any organisation should ask itself the question: 'If changing skill mix is the answer, what is the question?'

Cost Control↗
PubMed2001

An audit of oral care practice and staff knowledge in hospital palliative care.

Mouth care is considered one of the most basic of nursing activities, and palliative care patients are especially vulnerable to oral problems (Macmillan Practice Development Unit, 1995). This article describes a project on developing oral care practice and staff knowledge, by nursing staff and Macmillan nurses at a hospital in central England. A baseline audit (audit I) was carried out to examine all aspects of current oral care practice and nursing knowledge, including assessment, implementation, prescribing and evaluation of care. Oral care guidelines and a programme of ward-based teaching were then introduced. Several months later a follow-up audit (audit II) was conducted. Results showed an improvement in all aspects of oral care and staff knowledge. Additional benefits of this process included improved professional relationships and the promotion of further audits in hospital palliative care. Recommendations include the need for further nursing research into oral care to build the evidence base further. Additionally, it is suggested that nurses must recognize their important and central role in improving this aspect of palliative care. Education and training is pivotal to this process.

Humans↗
PubMed2000

Measurement of tensor polarization in elastic electron-deuteron scattering at large momentum transfer

Tensor polarization observables ( t(20), t(21), and t(22)) have been measured in elastic electron-deuteron scattering for six values of momentum transfer between 0.66 and 1.7 (GeV/c)(2). The experiment was performed at the Jefferson Laboratory in Hall C using the electron High Momentum Spectrometer, a specially designed deuteron magnetic channel and the recoil deuteron polarimeter POLDER. The new data determine to much larger Q2 the deuteron charge form factors G(C) and G(Q). They are in good agreement with relativistic calculations and disagree with perturbative QCD predictions.

Journal Article↗