Clinical ethics and HIV-related illnesses: issues in treatment and health services research.
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AIDS Serodiagnosis↗
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Antibiotic resistance in pathogenic Streptococcus pneumoniae isolates in Turkey.
Streptococcus pneumoniae causes various human infections such as meningitis, septicemia, otitis media, sinusitis, and pneumonia. Antibiotic resistance has already been reported with increasing frequency worldwide and is spreading. The earliest studies on pneumococcal antibiotic resistance go back to the late 1980s in Turkey. The resistance patterns have elevated with stepwise increments since then. By the beginning of 2005, approximately 40% of pneumococci were resistant to penicillin and nearly one-fifth of resistant isolates present high-level penicillin resistance. This proves that penicillin is still a good alternative for nonmeningeal infections. In addition, no ceftriaxone resistance have been reported in local Turkish studies, but cefuroxime, a second-generation cephalosporin, was recorded to have (10.8-20%) resistance rates. The most frequently assessed antibiotics other than penicillin in Turkish studies include erythromycin (4-19.4%), chloramphenicol (2-10%), clindamycin (2.5-13%) and tetracycline (13-28.6%) and all have various resistance profiles. On the other hand, nearly all or almost all of the isolates evaluated in Turkish studies are susceptible to rifampicin, quinolones, linezolid, quinupristin-dalfopristin and telithromycin. All these non-beta-lactam antibiotics except the tetracyclines are within acceptable limits of empirical approaches. Tetracycline must be used cautiously. In addition, trimethoprim sulfamethoxazole cannot be prescribed in probable pneumococcal infections since more than half of the isolates are nonsusceptible.
Anti-Bacterial Agents↗
Smoothing of the bivariate LOD score for non-normal quantitative traits.
Variance component analysis provides an efficient method for performing linkage analysis for quantitative traits. However, type I error of variance components-based likelihood ratio testing may be affected when phenotypic data are non-normally distributed (especially with high values of kurtosis). This results in inflated LOD scores when the normality assumption does not hold. Even though different solutions have been proposed to deal with this problem with univariate phenotypes, little work has been done in the multivariate case. We present an empirical approach to adjust the inflated LOD scores obtained from a bivariate phenotype that violates the assumption of normality. Using the Collaborative Study on the Genetics of Alcoholism data available for the Genetic Analysis Workshop 14, we show how bivariate linkage analysis with leptokurtotic traits gives an inflated type I error. We perform a novel correction that achieves acceptable levels of type I error.
Alcoholism↗
Cell biology as the basis of a better understanding of cancer.
Clinicians will argue that cancer can only really receive the treatment that is needed through thorough understanding of medicine. However, even empirical approaches to therapy result in experimental analysis of the agencies involved on test cells, usually in culture. From the obverse perspective, cell biologists will argue that until we fully understand cell cycle regulation, tumour management will be too imprecise to make the best advances. A forum is needed whereby the fundamental studies on cells prior to, during and after transformation in vitro can be freely reported (open access) and discussed. The action of anticancer agents and cancer preventative substances can more easily be studied in vitro before the often excessive complexity of making similar studies in experimental and human cancers is tackled. Cancer Cell International is committed to providing such a forum. Ironically within a few months of launching this open access journal, Elsevier had much the same idea, and there one has to pay for the privilege of downloading vital papers in this biomedical field.
Editorial↗
Impact of ivermectin on onchocerciasis transmission: assessing the empirical evidence that repeated ivermectin mass treatments may lead to elimination/eradication in West-Africa.
BACKGROUND: The Onchocerciasis Control Program (OCP) in West Africa has been closed down at the end of 2002. All subsequent control will be transferred to the participating countries and will almost entirely be based on periodic mass treatment with ivermectin. This makes the question whether elimination of infection or eradication of onchocerciasis can be achieved using this strategy of critical importance. This study was undertaken to explore this issue. METHODS: An empirical approach was adopted in which a comprehensive analysis was undertaken of available data on the impact of more than a decade of ivermectin treatment on onchocerciasis infection and transmission. Relevant entomological and epidemiological data from 14 river basins in the OCP and one basin in Cameroon were reviewed. Areas were distinguished by frequency of treatment (6-monthly or annually), endemicity level and additional control measures such as vector control. Assessment of results were in terms of epidemiological and entomological parameters, and as a measure of inputs, therapeutic and geographical coverage rates were used. RESULTS: In all of the river basins studied, ivermectin treatment sharply reduced prevalence and intensity of infection. Significant transmission, however, is still ongoing in some basins after 10-12 years of ivermectin treatment. In other basins, transmission may have been interrupted, but this needs to be confirmed by in-depth evaluations. In one mesoendemic basin, where 20 rounds of four-monthly treatment reduced prevalence of infection to levels as low as 2-3%, there was significant recrudescence of infection within a few years after interruption of treatment. CONCLUSIONS: Ivermectin treatment has been very successful in eliminating onchocerciasis as a public health problem. However, the results presented in this paper make it almost certain that repeated ivermectin mass treatment will not lead to the elimination of transmission of onchocerciasis from West Africa. Data on 6-monthly treatments are not sufficient to draw definitive conclusions.
Journal Article↗
Coping strategies in relatives of people with schizophrenia before and after psychiatric admission.
BACKGROUND: Most research on expressed emotion (EE) has used an empirical approach to describe relatives' ways of coping with people with schizophrenia. AIMS: To use the stress and coping model proposed by Lazarus and Folkman to examine how relatives coped with patients. METHOD: Patients with DSM-III-R schizophrenia and their relatives were assessed just after hospitalisation of the patients and nine months after discharge. Both assessments included the symptoms of the patients and the coping strategies, burden, distress and levels of EE of the relatives. RESULTS: Fifty patients and 50 relatives were assessed at inclusion, and 31 patients and 36 relatives at follow-up. Coping strategies were used more frequently at inclusion than at follow-up. Problem-focused coping was the strategy used more often at both assessments. Avoidance coping was strongly associated with burden, distress and high EE at both assessments. CONCLUSIONS: Ways of coping are influenced by relatives' perceptions of the situation with patients. Avoidance strategies seem to be less effective in regulating the distress of care-givers than problem-focused strategies.
Adaptation, Psychological↗
Disclosure of information to adult cancer patients: issues and update.
Clinicians are regularly faced with decisions regarding disclosure of information to cancer patients. Many of these decisions constitute a dilemma between the physician's paternalistic concern for the patient and the patient's right to know as much as possible. This paper reviews changes in the attitudes of physicians over the last several decades, elaborates on the problems that confront the clinician in the process of disclosure, and reviews the available data concerning the documented impact on the patient from receiving or not receiving information. The arguments both supporting and challenging the paternalistic view are discussed, and the necessity for viewing the disclosure of clinical information as a clinical process is offered.
Attitude of Health Personnel↗
The problems of R in clinical settings and in research: suggestions for the future.
It has been suggested that we control for R in the interpretation of individual Rorschach records. A related, but distinctly different issue concerns controlling for or equating R in research. I suggest we should not control for R in interpreting individual records. There are also some research paradigms in which controlling for R does not seem advisable. In other types of research, I argued that some method of controlling for or equating R appears appropriate. The distributions of many Rorschach factors are markedly non-normal, and in some cases the shapes of the distribution for a particular factor may be different among different populations. In these instances, when attempting to control statistically for R, improper model specification may lead to erroneous findings. Finally, I argue for a theory-based, empirical approach to all future Rorschach research.
Journal Article↗
Modeling eligibility under national systems of compensation for treatment injury.
How can different schemes of compensation for treatment injury be evaluated? This article offers an empirical approach to assessment based on the simulation of alternative models of eligibility using real-world data. It draws on information about adverse events generated from a representative survey of public hospital admissions in New Zealand and classifies these under a range of eligibility criteria for different possible compensation systems. These are then evaluated according to a number of policy design considerations, using variables available from the New Zealand study.
Adolescent↗
An intriguing fragment of pre-hippocratic medicine in Aeschylus.
Information scattered in several passages of Greek tragedies of the 5th century BC contributes to our knowledge of pre-Hippocratic medicine and throws light on the cultural background of the Hippocratic writers. In this regard, the work of Aeschylus is noteworthy, because it contains fragments of an ideal-conjectural conception preceding the empirical approach based on observation and experience. The idealized meaning attributed to the term muupsilonepsilonlambdaóç (marrow), compared with both Homeric epics and Hippocratic writings, represents a reliable index of the evolution of the ancient medical thought.
Animals↗
The cost of hovering and forward flight in a nectar-feeding bat, Glossophaga soricina, estimated from aerodynamic theory.
Energy expenditure during flight in animals can best be understood and quantified when both theoretical and empirical approaches are used concurrently. This paper examines one of four methods that we have used to estimate the cost of flight in a neotropical nectar-feeding bat Glossophaga soricina (Phyllostomidae), namely the use of kinematic and morphological data and aerodynamic theory to estimate the mechanical power requirements (power output) for hovering and horizontal forward flight. A hot-wire anemometer was used to measure induced velocity (the velocity of air accelerated by the wings) during hovering in order to estimate induced power. Our estimate of aerodynamic power (the sum of induced, profile and parasite powers) required for a 0.0105 kg G. soricina to hover is 0.15 W and our estimate of the inertial power (the power required to oscillate the wings) is 0.19 W. Thus, the total mechanical power for hovering is 0.34 W or 32.4 W kg-1. The mechanical power required for horizontal forward flight, near the minimum power flight speed (4.2 ms-1) for a 0.0117 kg bat is 0.14 W (12.3 W kg-1), of which 0.10 W is aerodynamic power and 0.042 W is inertial power. Comparison with our results on metabolic power requirements estimated from nectar intake gives a mechanical efficiency of 0.15 for hovering flight and 0.11 for forward flight near the minimum power speed.
Animals↗
Individual differences in neural sensitization and the role of context in illness from low-level environmental chemical exposures.
This paper summarizes the clinical phenomenology of multiple chemical sensitivity (MCS), outlines the concepts and evidence for the olfactory-limbic, neural sensitization model for MCS, and discusses experimental design implications of the model for exposure-related research. Neural sensitization is the progressive amplification of responsivity by the passage of time between repeated, intermittent exposures. Initiation of sensitization may require single toxic or multiple subtoxic exposures, but subsequent elicitation of sensitized responses can involve low or nontoxic levels. Thus, neural sensitization could account for the ability of low levels of environmental chemicals to elicit clinically severe, adverse reactions in MCS. Different forms of sensitization include limbic kindling of seizures (compare temporal lobe epilepsy and simple partial seizures) and time-dependent sensitization of behavioral, neurochemical, immunological, and endocrinological variables. Sensitized dysfunction of the limbic and mesolimbic systems could account in part for many of the cognitive, affective, and somatic symptoms in MCS. Derealization (an alteration in perception making familiar objects or people seem unfamiliar or unreal) is a common MCS symptom and has been linked with limbic dysfunction in clinical neuroscience research. Sensitization is distinct from, but interactive with, other neurobiological learning and memory processes such as conditioning and habituation (compare adaptation or tolerance). In previous studies, hypotheses for MCS involving sensitization, conditioning, and habituation (adaptation) have often been considered in isolation from one another. To design more appropriate chemical exposure studies, it may be important to integrate the various theoretical models and empirical approaches to MCS with the larger scientific literature on individual differences in these potentially interactive phenomena.
Adaptation, Physiological↗
Generation of hybrid cell lines with endothelial potential from spontaneous fusion of adult bone marrow cells with embryonic fibroblast feeder.
We have previously isolated mouse embryonic cell lines with endothelial potential using a simple empirical approach. In an attempt to isolate similar cell lines from adult mouse bone marrow (BM), BM cells were cultured on mitotically inactive mouse embryonic fibroblast (MEF) feeder cells. Several cell lines with putative endothelial potential were generated. They expressed endothelial-specific genes and formed vascular-like structures when plated on matrigel. When transplanted into appropriate mouse models, they incorporated into the endothelium of the vasculature. Similar cell lines were also obtained using human or porcine BM. None of these lines induced tumor formation when transplanted into immunodeficient Rag1-/- mice. However, all the lines were aneuploid with genetic markers from BM samples and the MEF feeder, suggesting that they resulted from a non-species-specific fusion of a BM cell and mitotically inactive MEF. Together, these lines demonstrated for the first time that BM cells can also undergo fusion with commonly used mitotically inactive feeder cells. Although these fusion cell lines were culture artifacts, their derivation would be useful in understanding fusion of BM cells with other cell types, and their endothelial potential will also be useful in characterizing endothelial differentiation.
Aneuploidy↗
State strategies to support community based long term care for the elderly.
States play a principal role in designing and implementing publicly funded long term care programs. They are in a key position to determine what setting, from whom, and under what philosophy of care individuals can access long term care. State long term care systems have evolved over the past 25 years to support increased availability of community based care for older individuals. States have pursued three broad strategies to increase availability. One set of strategies aims to increase capacity through expanding the supply, public funding and eligibility for a wide array of home and community based services (HCBS). A second set of strategies seeks to constrain institutional growth in order to increase the dollars available for HCBS. Managed/capitated long term care is a third strategy that is a hybrid of the other two approaches. Empirically, increased capacity through use of Medicaid and Medicare resources and growth in the supply of community based care providers, combined with moderation of institutional bed supply, are associated with enhanced access and expenditures for community based long term care. The effectiveness of capitated or managed systems of care varies by model and in some cases is still under study. State fiscal resources are key to the ability to support community based care for the elderly. Targeted federal support may be critical to the continued expansion of community based care, given heterogeneity in state resources, coupled with an increasing demand for long term care.
Aged↗
The cost of ethics legislation: a look at the Patient Self-Determination Act.
The Patient Self-Determination Act (PSDA) requires hospitals to ask patients upon admission whether they have an advance directive. Although the PSDA has received extensive criticism, little attention has been paid to the cost of the law, either during its legislative course or following its implementation. Nonetheless, several tangible and intangible costs are associated with the PSDA. Such costs may be incurred by different parties. This paper examines the costs and benefits of the PSDA and illustrates the extent of some of its tangible costs. The incremental start-up cost for one institution's response to the PSDA is estimated to be $49,304 ($1.31 per admission) and the total implementation cost of the program to be $114,528. In addition, the national incremental start-up cost for hospitals to implement the PSDA is estimated to be between $43,625,114 and $101,569,922. Finally, the potential implications of the PSDA for future governmental health care ethics regulation are discussed.
Advance Directives↗
Comparison of Cartesian grid configurations for application of the finite-difference time-domain method to electromagnetic scattering by dielectric particles.
Two grid configurations can be employed to implement the finite-difference time-domain (FDTD) technique in a Cartesian system. One configuration defines the electric and magnetic field components at the cell edges and cell-face centers, respectively, whereas the other reverses these definitions. These two grid configurations differ in terms of implication on the electromagnetic boundary conditions if the scatterer in the FDTD computation is a dielectric particle. The permittivity has an abrupt transition at the cell interface if the dielectric properties of two adjacent cells are not identical. Similarly, the discontinuity of permittivity is also observed at the edges of neighboring cells that are different in terms of their dielectric constants. We present two FDTD schemes for light scattering by dielectric particles to overcome the above-mentioned discontinuity on the basis of the electromagnetic boundary conditions for the two Cartesian grid configurations. We also present an empirical approach to accelerate the convergence of the discrete Fourier transform to obtain the field values in the frequency domain. As a new application of the FDTD method, we investigate the scattering properties of multibranched bullet-rosette ice crystals at both visible and thermal infrared wavelengths.
Journal Article↗
CD4 T lymphocyte count and the radiographic presentation of pulmonary tuberculosis. A study of the relationship between these factors in patients with human immunodeficiency virus infection.
BACKGROUND: Pulmonary infection and tumor in the AIDS population has a variable clinical and radiographic presentation. The association between the radiographic presentation of pulmonary tuberculosis and CD4 T lymphocyte count in the HIV-infected patient is investigated in order to provide an empirical approach for early diagnosis, treatment, and isolation of infected subjects. METHODS: A retrospective analysis of chest radiographs, CD4 T lymphocyte counts, and clinical history of 35 subjects from 3 urban hospitals was performed. All subjects were HIV-seropositive and had culture-proven pulmonary tuberculosis. Radiographs were evaluated for the presence of either a pattern characteristic of post-primary tuberculosis (typical pattern) or a pattern uncharacteristic of post-primary infection (atypical pattern). RESULTS: Twenty-one of 26 subjects with a CD4 T lymphocyte count less than 0.20 x 10(9) cells/L, whereas only 1 of 9 subjects with a CD4 T lymphocyte count of 0.20 x 10(9) cells/L or more presented with an atypical pattern of pulmonary tuberculosis (p < 0.001). The mean CD4 T lymphocyte counts of those subjects presenting with atypical versus typical radiographic pattern of post-primary pulmonary tuberculosis were 0.069 x 10(9) cells/L (n = 22) and 0.323 x 10(9) cells/L (n = 13), respectively (p < 0.01). Twenty-one of the 22 subjects with an atypical radiographic pattern of pulmonary tuberculosis were significantly immunosuppressed (CD4 < 0.20 x 10(9) cells/L). Atypical radiographic pattern included diffuse and lower lobar opacities, pleural effusion, mediastinal adenopathy, interstitial nodules, and a normal chest radiograph. CONCLUSION: AIDS patients presenting with CD4 count less than 0.20 x 10(9) cells/L and an atypical radiographic pattern for pulmonary tuberculosis are at risk for tuberculous infection requiring appropriate treatment and isolation until the diagnosis of pulmonary tuberculosis has been excluded.
AIDS-Related Opportunistic Infections↗
Effect of lactobacilli administration in the vaginal tract of mice: evaluation of side effects and local immune response by local administration of selected strains.
Lactobacilli are the predominant microorganisms in the vaginal tract of human and some homeothermic animals. They can maintain the ecological equilibrium of the tract by protecting against pathogenic microorganisms. In the last few years, there has been an increased tendency to use probiotic microorganisms to restore the ecological equilibrium and to protect against infections. This principle has been widely applied to the gastrointestinal tract. More recently, some other studies have reported the application of probiotics in different tracts, for example, the urogenital or respiratory tract. One of the objectives of our group is to design probiotic products for the urogenital tract. With this purpose, lactobacilli were isolated from the human vagina, and later some of them were selected for their probiotic characteristics (production of antagonistic substances or adhesion capability). The application of probiotic products in the vaginal tract has been approached empirically; some pharmaceuticals containing these microorganisms are available in the United States or Europe or are protected under the patent process or intellectual property rights. There are not enough studies in humans or animals to determine whether their administration can produce some type of collateral or adverse effect. Using Balb/c mice as the experimental model, the object of the present work was to study (1) whether intravaginal administration of human lactobacilli can produce colonization of the tract; (2) whether such administration produces some type of adverse or collateral effect; and (3) whether probiotics are able to stimulate the local immune system. Keeping in mind that hormones can affect the colonization or persistence ability of microorganisms, and with the purpose of having all animals at the same point in the sexual cycle, animals were cycled with estradiol 48 h before inoculation with lactobacilli. They were then inoculated im with hormones 48 h before beginning microorganism inoculations. Later they were intravaginally inoculated with the appropriate dose of each Lactobacillus strains. The animals were sacrificed on different days after inoculation to perform the following studies: 1. Microbiological assays: To determine the number of lactobacilli in the tract (in vaginal washes or in organ homogenates), by plating the samples in selective media containing antibiotic (to differentiate the resident flora from those administered experimentally).
Animals↗