Multivariate Markov chain analysis of the probability of pregnancy in infertile couples undergoing assisted reproduction.

BACKGROUND: Estimating the probability of pregnancy leading to delivery and the influence of clinical factors on that probability is of fundamental importance in the treatment counselling of infertile couples. A variety of statistical techniques have been used to analyse fertility data, many borrowed from survival analysis. METHODS AND RESULTS: We propose an alternative method of analysis which is based on a discrete time Markov chain approach, with states 'pregnancy (leading to a delivery)', 'not pregnant', and 'censored' and in which the transition probabilities are dependent both on the clinical characteristics of the patient and the treatment given. CONCLUSIONS: We believe that the method of analysis presented here may be preferable to standard analyses in that it better reflects the clinical situation, it is a truly discrete time analysis applied to a discrete time situation, it explicitly models the censoring process (a process which in itself provides information of interest to the physician) and can be readily extended to a variety of clinical situations.     

Methicillin-resistant Staphylococcus aureus: laboratory detection methods in use in the Republic of Ireland and Northern Ireland

There is no universally agreed laboratory protocol for the detection of methicillin-resistant Staphylococcus aureus (MRSA) and hence a variety of approaches are used. As part of an all-island survey of MRSA in the Republic of Ireland (the South) and Northern Ireland (the North), a questionnaire was circulated to 14 participating laboratories in the North and 49 in the South, to determine the methods used to isolate MRSA from clinical specimens, identify S. aureus and test for susceptibility to methicillin. Almost two-thirds (64%) of laboratories in the North but only 16% of laboratories in the South use enrichment culture. There is heavy reliance on commercial kits to confirm the identification of S. aureus in the South but all laboratories in the North use the staphylocoagulase test. More than 90% of all laboratories use a disc method for susceptibility testing and 71% of laboratories in the North supplement this with the E-test; however, a range of methicillin disk concentrations are in use. There is a need to review current laboratory methods used to detect MRSA, with follow-up audit on their implementation. Additional resources may be needed in some laboratories to comply with revised guidelines, and reference facilities are required to assess new commercially available techniques and to confirm the identification of unusual or difficult strains.     

Apoptotic rate in peripheral T-cell lymphomas. A study using a tissue microarray with validation on full tissue sections

Peripheral T-cell lymphomas (PTCLs) are a heterogeneous group of non-Hodgkin lymphomas with a wide spectrum of clinicopathologic features, and apoptosis mechanisms may have a role in lymphomagenesis. We assessed apoptotic rate (AR) in 112 PTCLs using a tissue microarray developed in our laboratory and a modified terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. The mean AR was 1.47% +/- 1.38% for the entire group of PTCLs (range, 0.06%-5.15%), and AR varied significantly among different tumor types. In mycosis fungoides, the mean AR was 0.74%; angioimmunoblastic T-cell lymphoma, 1.02%; PTCL, not otherwise specified, 1.38%; cutaneous anaplastic large cell lymphoma (ALCL), 1.41%; anaplastic lymphoma kinase protein (ALK)-negative ALCL, 1.43%; extranodal natural killer/T-cell lymphoma of nasal type, 2.04%; ALK-positive ALCL, 2.95%; and enteropathy-type T-cell lymphoma, 3.06%. Mean AR was higher in PTCL with large cell vs small/medium cell morphologic features (1.66% +/- 1.1% vs 0.99% +/- 1.0%). In a subset of 33 PTCLs, the tissue microarray results comparedfavorably with those obtained in full tissue sections. We conclude that the highest ARs in PTCLs are found in enteropathy-type T-cell lymphoma and ALK-positive ALCL, and that AR can be assessed reliably by using a tissue microarray.     

Pyridinyl imidazoles inhibit IL-1 and TNF production at the protein level

The mechanism by which SK&F 86002 and other pyridinyl imidazoles inhibit the production of IL-1 and TNF from LPS-stimulated human monocytes was examined. Inhibition of IL-1 and TNF production was found to depend on the time of addition of SK&F 86002, with diminishing effect when added more than 2 h after LPS stimulation. Analysis of Western blots confirmed that both intracellular IL-1β and extracellular TNF were significantly reduced in response to SK&F 86002, but these reductions were not paralleled by changes in IL-1 and TNF mRNA.³⁵S methionine pulse and pulse-chase studies on IL-1 biosynthesis suggest that significant inhibition by SK&F 86002 and related compounds occurs at the translational level.

     

Acute and custodial care among impaired aged

The authors surveyed a community-based population of 628 persons who were 65 and over and who lived either in a rural Maryland county or in Baltimore. For each subject, the number of different medical problems, the subject's capacity to perform physical tasks, and the ability to function were assessed. The number and type of medical problems tended to be the best predictors of whether or not hospital or physician's office care were used, and of the volume of physician's office visits for subjects who sought outpatient care. The subject's ability to function was the best predictor of whether or not the subject used a paid home aide and the volume of family caregiving. Implications for research on association between need and use of long-term care are discussed.     

Assessing and planning home-based care for persons with AIDS

The HIV/AIDS pandemic continues to gather momentum in many developing countries, increasing the already heavy burden on health care facilities. As a result, donors, implementing partners and communities are beginning to create home-based care programmes to provide care for persons with HIV/AIDS. This paper recommends reorienting this home care provision as a service founded in, and coming from, the community rather than the health system. A methodology, in the form of an assessment matrix, is provided to facilitate the assessment of a community's capacity to provide care for people with AIDS. The focus is on rapid assessment methods using, where possible, readily available information to clearly and systematically define current circumstances. The matrix created for a specific community is then used in the development of an action plan with interventions prioritized and tailored to local needs. A case study from a hypothetical developing country, where HIV/AIDS is a significant problem, is used to illustrate the process.     

Mechanical methods in refractive corneal surgery

Over the past decade, keratorefractive surgery has moved into the mainstream of ophthalmology as improved instrumentation and newer techniques have evolved. These new aspects increase the safety and effectiveness of the various keratorefractive procedures. The introduction of new techniques and knife designs has led to improved results with radial keratotomy. The newly developed arcuate keratome purportedly offers the possibility of improving the predictability of arcuate keratotomy. Keratomileusis and epikeratoplasty have been successful for some difficult refractive states, such as aphakia and high myopia. Intracorneal lenses are showing promise in correcting high refractive errors and may offer an alternative to the more technically challenging lamellar procedures performed for correcting these conditions. Intrastromal ring implants are early in their clinical testing, but may provide an alternative to radial keratotomy for correcting myopia. The predictability, effectiveness, safety, and stability are far from perfect for current procedures, but recent results are encouraging.