Childhood accident prevention: putting audit into practice

This article describes an audit of children presenting at accident and emergency departments following an accident. The authors explain how the audit data informed a strategy for childhood accident prevention schemes in Newcastle for 1995/96.

Gene trapping in differentiating cell lines: regulation of the lysosomal protease cathepsin B in skeletal myoblast growth and fusion

To identify genes regulated during skeletal muscle differentiation, we have infected mouse C2C12 myoblasts with retroviral gene trap vectors, containing a promoterless marker gene with a 5' splice acceptor signal. Integration of the vector adjacent to an actively transcribed gene places the marker under the transcriptional control of the endogenous gene, while the adjacent vector sequences facilitate cloning. The vector insertionally mutates the trapped locus and may also form fusion proteins with the endogenous gene product. We have screened several hundred clones, each containing a trapping vector integrated into a different endogenous gene. In agreement with previous estimates based on hybridization kinetics, we find that a large proportion of all genes expressed in myoblasts are regulated during differentiation. Many of these genes undergo unique temporal patterns of activation or repression during cell growth and myotube formation, and some show specific patterns of subcellular localization. The first gene we have identified with this strategy is the lysosomal cysteine protease cathepsin B. Expression from the trapped allele is upregulated during early myoblast fusion and downregulated in myotubes. A direct role for cathepsin B in myoblast growth and fusion is suggested by the observation that the trapped cells deficient in cathepsin B activity have an unusual morphology and reduced survival in low-serum media and undergo differentiation with impaired cellular fusion. The phenotype is reproduced by antisense cathepsin B expression in parental C2C12 myoblasts. The cellular phenotype is similar to that observed in cultured myoblasts from patients with I cell disease, in which there is diminished accumulation of lysosomal enzymes. This suggests that a specific deficiency of cathepsin B could contribute to the myopathic component of this illness.

X linked agammaglobulinaemia with a 'leaky' phenotype

Typical X linked agammaglobulinaemia (XLA) is characterised by absence of immunoglobulin production and lack of mature B cells. The gene responsible for XLA has recently been identified, and codes for a B cell tyrosine kinase, BTK. A family affected by a B cell immunodeficiency, which is less severe than classical XLA, is described but they had a pedigree suggestive of X linked inheritance. Demonstration of a mutation in the BTK gene confirms that this is a mild form of XLA.

Confidence intervals in QTL mapping by bootstrapping

The determination of empirical confidence intervals for the location of quantitative trait loci (QTLs) was investigated using simulation. Empirical confidence intervals were calculated using a bootstrap resampling method for a backcross population derived from inbred lines. Sample sizes were either 200 or 500 individuals, and the QTL explained 1, 5, or 10% of the phenotypic variance. The method worked well in that the proportion of empirical confidence intervals that contained the simulated QTL was close to expectation. In general, the confidence intervals were slightly conservatively biased. Correlations between the test statistic and the width of the confidence interval were strongly negative, so that the stronger the evidence for a QTL segregating, the smaller the empirical confidence interval for its location. The size of the average confidence interval depended heavily on the population size and the effect of the QTL. Marker spacing had only a small effect on the average empirical confidence interval. The LOD drop-off method to calculate empirical support intervals gave confidence intervals that generally were too small, in particular if confidence intervals were calculated only for samples above a certain significance threshold. The bootstrap method is easy to implement and is useful in the analysis of experimental data.

Community-oriented primary care in a family practice residency program

BACKGROUND

The practice of medicine needs to include disease prevention, health promotion, community health, and clinical epidemiology. Community-oriented primary care (COPC) can be used as an educational strategy to develop competencies in these areas.

METHODOLOGY

An interdisciplinary team that included public health representatives was created to teach COPC principles to family practice residents and supervise their community projects. Allied health and nursing graduate students were also involved in the process. Projects were implemented in collaboration with community representatives.

RESULTS

Family practice residents and community representatives were positive about working together. The family practice residents appreciated the interdisciplinary experience and reported that the COPC model will be useful to them in the future. However, the program's didactic phase was insufficient to provide adequate skills for use of the COPC process. The program could benefit from more involvement of medical students and students in other health professions.

CONCLUSIONS

The program encountered several significant obstacles such as competing clinical priorities, limited health education skills, and inadequate project evaluations. Despite the challenges, the family practice residents, as well as the interdisciplinary faculty, health science graduate students, and community representatives, reported a positive experience.

The transcriptional activator Opaque-2 controls the expression of a cytosolic form of pyruvate orthophosphate dikinase-1 in maize endosperms

The maize Opaque-2 (O2) protein is a transcription factor of the basic/leucine-zipper class, involved in the regulation of endosperm proteins including the 22kDa alpha-zein storage proteins and b32 protein. In this study we have focussed our attention on the relationship between O2 and the cyPPDK1 gene, which encodes a cytoplasmic pyruvate orthophosphate dikinase (PPDK) isoform. The results of this study showed that PPDK activity is detectable in wild-type maize endosperms, while in o2 mutant endosperms, the levels of PPDK protein, mRNA and enzymatic activity are reduced, indicating that O2 is involved in the regulation of cyPPDK1 in this tissue. By employing transient expression experiments in tobacco mesophyll protoplasts, we have demonstrated that the O2 protein can activate expression of a chloramphenicol acetyl transferase reporter gene placed under the control of the cyPPDK1 promoter. An in vitro binding assay and DNaseI footprint analysis demonstrated that a specific sequence in the cyPPDK1 promoter can be recognized and protected by maize O2 protein. The regulation by the O2 locus of cyPPDK1 reported here, and control of alpha-zein synthesis by O2 suggest that the O2 protein may play a more general role in maize endosperm development than previously thought.

Pharmacokinetics in nonhuman primates of a prototype carbapenem active against methicillin-resistant Staphylococcus aureus

Pharmacokinetic parameters were determined for imipenem-cilastatin and a carbapenem antibiotic, L-695,256, active against methicillin-resistant Staphylococcus aureus in rhesus monkeys and a chimpanzee. L-695,256 had larger areas under the concentration-time curve than imipenem-cilastatin (30 +/- 5 versus 24 +/- 1 micrograms.h/ml in the rhesus monkeys and 77 versus 60 micrograms.h/ml in the chimpanzee) and a longer half-life at beta phase (1.2 +/- 0.1 versus 0.6 +/- 0.1 h in the rhesus monkeys and 1.0 versus 0.8 h in the chimpanzee). Resistance to hydrolysis by the renal dehydropeptidase-I allowed L-695,256 to be administered as a single agent.

Redesigning the RN and NA roles

To ensure optimal utilization of RNs, the nursing care delivery system in a surgical nursing division assessed the tasks that could be delegated to ancillary personnel. Nursing assistants completed competency-based training and after six months, several positive outcomes were evident: dramatic decreases in overtime, improved patient care and increased patient and staff satisfaction.

The clinical success and periodontal evaluation of patients rehabilitated with light-cured obturators

The clinical performance of a visible light-cured (VLC) resin for obturators was evaluated in 10 patients. All patients had undergone ablative surgery of the maxilla, previously worn conventional heat-cured hollow bulb acrylic obturators and were currently rehabilitated with VLC obturators. The obturators were assessed on their performance for each of the following: weight, retention, speech, eating and comfort. An evaluation of the periodontal status of those who retained teeth in the maxilla was also performed. It is concluded that patients found VLC obturators to have a more acceptable clinical performance than conventional acrylic obturators due primarily to a reduction in appliance weight.

Epidermal growth factor (EGF) promotes chemomigration of a human prostate tumor cell line, and EGF immunoreactive proteins are present at sites of metastasis in the stroma of lymph nodes and medullary bone

Prostate tumor cells preferentially metastasize to bony sites and lymph nodes at a frequency in excess of that which would be predicted by random tumor cell dissemination. In order to determine whether chemoattractants in these organs promote organ-specific metastasis, we utilized human cell lines derived from and/or related to these organs as sources of potential chemoattractants. Secretory proteins derived from the cell lines MG-63 (osteosarcoma), SK-ES-1 (Ewing's sarcoma), and KG-1 (leukemia) stimulated chemomigration of the TSU-pr1 prostate tumor cells in a dose-dependent manner in Boyden chambers. In addition, secretory proteins from a human prostatic stromal cell line (hPS) and from the TSU-Pr1 prostate tumor cell line were also able to stimulate chemomigration of the TSU-pr1 cells through Boyden chambers. Since lymph nodes and bony sites represent organs of hematopoietic/lymphoid proliferation and activation, we undertook identification of specific cytokines present at these sites which may promote the chemomigration of prostate tumor cells. In this context, the cytokines interleukin-1 alpha, interleukin-2, interleukin-6, tumor necrosis factor-beta, transforming growth factor-beta, interferon alpha 2-a, and granulocyte-macrophage colony-stimulating factor did not stimulate chemomigration of the TSU-pr1 prostate tumor cell line. In contrast, the cytokine epidermal growth factor (EGF) stimulated chemomigration of the TSU-pr1 prostate tumor cells through the Boyden chambers in a dose-dependent manner. Western blot analysis of secretory proteins from the cell lines KG-1, SK-ES-1, MG-63, hPS, and TSU-pr1 identified EGF-immunoreactive proteins in all cases. In addition, EGF immunoreactivity was localized to the stroma of the human prostate, the osteogenic stroma of pelvic medullary bone, and the stroma within the capsule and trabeculae of pelvic lymph nodes. Hence, these results demonstrate that the cytokine EGF promotes the chemomigration of the TSU-pr1 prostate tumor cell line, and that EGF within the stroma of pelvic lymph nodes and medullary bone may act as a chemoattractant for prostate tumor cells, thereby facilitating the preferential formation of metastatic foci within these organs.

Surgical repair of pressure ulcers

A team approach is required for the surgical management of the spinal cord-injured patient with a pressure ulcer, beginning preoperatively with patient selection and preparation, continuing through wound debridement and flap closure, and progressing to rehabilitation and patient education. Although possible surgical complications are numerous and the recurrence rate is relatively high, the surgical management of patients with pressure ulcers can be very rewarding. Goals for surgical closure of pressure ulcers include reduction of protein loss through the wound, reduction of rehabilitation costs, prevention of progressive osteomyelitis, and improvement of patient hygiene. The ultimate reward is the restoration of patients to the rehabilitated sitting position so that they can enjoy productive and happy lives.

The analysis of the NSW wheat variety database. II. Variance component estimation

The efficiency of various trialling systems for wheat variety evaluation in New South Wales (NSW) is considered. This involved the estimation of the variance components due to genotype, genotype-by-year, genotype-by-location and genotype-by-year-by-location. It is shown that there is a significant reduction in the magnitude of these variance components by the inclusion of the interaction of genotype maturity, winter habit and aluminium tolerance with environment.

The analysis of the NSW wheat variety database. I. Modelling trial error variance

The retrospective analysis of a large database on wheat variety testing in New South Wales (NSW) is considered. This analysis involved three key steps. Initially error variance heterogeneity is modelled, indicating significant differences in error variance due to trial location, year of trialling, sowing date and trial mean yield. The implication of this modelling for the estimaion of variance components is discussed.

The treatment of covert self-injury through contingencies on response products

Assessment and treatment of covert self-injurious behavior are complicated because it is difficult to quantify and apply differential consequences to covert responses. In this study, both tangible and social reinforcers were identified using reinforcer assessment methods. These reinforcers were then provided contingent upon the absence of tissue damage identified during physical examinations, resulting in near 100% success in physical assessment checks that was maintained over 10 months.

A study of the clinical outcome of patients with profound mental retardation gradually withdrawn from chronic neuroleptic medication

In a naturalistic study of 23 severely and profoundly mentally retarded adult male patients undergoing slow "diagnostic" neuroleptic taper, it was determined that at least 60% could eventually be managed without psychoactive medication. However, many of these demonstrated a remarkably long, but nonetheless transient, period of worsening. This suggests that behavioral deterioration during drug reduction trials does not always indicate a need for chronic neuroleptic maintenance since these behaviors may return to baseline without pharmacological intervention. On the other hand, 40% demonstrated persistent (> 2 years) behavioral worsening. Those individuals who demonstrated persistent deterioration had been generally well controlled on neuroleptics, were somewhat older, and were receiving a higher baseline dose. Most of these persistently worsened subjects currently require some type of psychoactive medication (although only two have been returned to neuroleptics).

Using marker-maps in marker-assisted selection

A method of using information on the location of markers to improve the efficiency of marker-assisted selection (MAS) in a population produced by a cross between two inbred lines is developed. The method is closer to mapping QTL than the selection index approaches to MAS described by previous authors. We use computer simulations to compare our method with phenotypic selection and two selection index approaches, simulations being performed on three genetic maps. The simulations show that whilst MAS can be considerably more efficient than phenotypic selection differences between the three MAS methods are slight. Which of the MAS methods is best depends on a number of factors: in particular the genetic map, the time scale under consideration ant the population size are of importance.

Participative decision making: multidisciplinary team involvement in unit design

This article describes the multidisciplinary team's input into the design and construction of an Epilepsy Monitoring Unit. The unit construction was a collaborative effort of a multidisciplinary team based in part on patient input as well as economic and efficiency factors. The Unit has resulted in long term rewards for both patients and staff. Patients benefit from the friendly environment created and staff benefits are due to the increased efficiency of the unit--working smarter not harder and the knowledge that staff nurses were an integral part of the planning process of this highly successful project.

Application of Gibbs sampling for inference in a mixed major gene-polygenic inheritance model in animal populations

The application of Gibbs sampling is considered for inference in a mixed inheritance model in animal populations. Implementation of the Gibbs sampler on scalar components, as used for human populations, appeared not to be efficient, and an approach with blockwise sampling of genotypes was proposed for use in animal populations. The blockwise sampling of genotypes was proposed for use in animal populations. The blockwise sampling by which genotypes of a sire and its final progeny were sampled jointly was effective in improving mixing, although further improvements could be looked for. Posterior densities of parameters were visualised from Gibbs samples; from the former highly marginalised Bayesian point and interval estimates can be obtained.