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PubMed2004

Population health management as a strategy for creation of optimal healing environments in worksite and corporate settings.

This paper provides an (OHE) overview of a population health management (PHM) approach to the creation of optimal healing environments (OHEs) in worksite and corporate settings. It presents a framework for consideration as the context for potential research projects to examine the health, well-being, and economic effects of a set of newer "virtual" prevention interventions operating in an integrated manner in worksite settings. The main topics discussed are the fundamentals of PHM with basic terminology and core principles, a description of PHM core technology and implications of a PHM approach to creating OHEs.

Health Education↗
PubMed2001

Presence revisited: imagination, competence, and activity in text-based virtual worlds.

Presence is the sense of being caught up in the representations of virtual worlds. Drawing on social and literary theories and on ethnographic fieldwork, this paper examines the ways in which imagination, competence, and activity promote or undermine a sense of presence in online text-based environments known as MOOs. These factors vary for newbies, socials, and techies, categories that reflect differences in length of experience in participating in these worlds, in comfort and/or competence in the use of commands for navigation and communication, and in the interests and/or degree of participation in socializing or programming.

Cognition↗
PubMed1979

Periodontal therapy by local delivery of tetracycline.

The present investigation assessed the feasibility of treating periodontal disease by controlled delivery of antibacterial agents from within periodontal pockets. Tetracycline-filled hollow fibers placed in the gingival sulcus were shown to have a dramatic effect both on the periodontal microflora and clinical manifestations of disease. Furthermore, it was found that drug-filled cellulose acetate hollow fibers are biologically compatible with the environment and can be manipulated by dental personnel to provide drug therapy with less than 1/1000 the amount of tetracycline that would have been used for systemic therapy. Of theoretical importance is the observation that virtual elimination of spirochetes from the gingival sulcus is possible by a single placement of tetracycline-filled hollow fibers, and spirochetes, once eliminated from a site, do not rapidly recolonize despite the persistence of viable organisms elsewhere in the mouth.

Delayed-Action Preparations↗
PubMed2003

Make no mistake-errors can be controlled.

Traditional quality control methods identify "variation" as the enemy. However, the control of variation by itself can never achieve the remarkably low non-conformance rates of world class quality leaders. Because the control of variation does not achieve the highest levels of quality, an inordinate focus on these techniques obscures key quality improvement opportunities and results in unnecessary pain and suffering for patients, and embarrassment, litigation, and loss of revenue for healthcare providers. Recent experience has shown that mistakes are the most common cause of problems in health care as well as in other industrial environments. Excessive product and process complexity contributes to both excessive variation and unnecessary mistakes. The best methods for controlling variation, mistakes, and complexity are each a form of mistake proofing. Using these mistake proofing techniques, virtually every mistake and non-conformance can be controlled at a fraction of the cost of traditional quality control methods.

Humans↗
PubMed2002

Integration of text, image, and graphic data from different sources in laboratory reports: example of kidney stone reporting system.

Laboratory analyses may generate multiple data types that may reside in disparate systems, and combining data into a report often requires laborious, error-prone methods. Kidney stone analysis, which includes biochemical composition analysis and gross feature documentation, is an example of such a situation. We developed the kidney stone reporting system (KISS) that integrates patient and specimen information from the laboratory information system, digital images of stones, and analytic instrument data into a concise report for the ordering clinicians. The database management environment facilitates archival and retrieval capabilities. Implementation of the system has reduced the number of manual steps necessary to produce a report and has saved approximately 30 technologist hours per week. Transcription errors have been virtually eliminated. The KISS represents an innovative use of standard tools to integrate text, image, and graphic data from disparate systems into an integrated laboratory report, without the need for expensive interfaces.

Clinical Laboratory Information Systems↗
PubMed2007

The endocrine system in chronic nitric oxide deficiency.

The experimental model of chronic inhibition of nitric oxide (NO) production has proven to be a useful tool to study cardiovascular and renal lesions produced by this type of hypertension, which are similar to those found in human hypertension. It also offers a unique opportunity to study the interaction of NO with the humoral systems, known to have a role in the normal physiology of vascular tone and renal function. This review provides a thorough and updated analysis of the interactions of NO with the endocrine system. There is special focus on the main vasoactive factors, including the renin-angiotensin-aldosterone system, catecholamines, vasopressin, and endothelin among others. Recent discoveries of crosstalk between the endocrine system and NO are also reported. Study of these humoral interactions indicates that NO is a molecule with ubiquitous function and that its inhibition alters virtually to all other known regulatory systems. Thus, hypothyroidism attenuates the pressor effect of NO inhibitor N-nitro-L-arginine methyl ester, whereas hyperthyroidism aggravates the effects of NO synthesis inhibition; the sex hormone environment determines the blood pressure response to NO blockade; NO may play a homeostatic role against the prohypertensive effects of mineralocorticoids, thyroid hormones and insulin; and finally, NO deficiency affects not only blood pressure but also glucose and lipid homeostasis, mimicking the human metabolic syndrome X, suggesting that NO deficiency may be a link between metabolic and cardiovascular disease.

Animals↗
PubMed2006

Highly-realistic, immersive training environment for hysteroscopy.

The primary driving application of our current research is the development of a generic surgical training simulator for hysteroscopy. A key target is to go beyond rehearsal of basic manipulative skills, and enable training of procedural skills like decision making and problem solving. In this respect, the sense of presence plays an important role in the achievable training effect. To enable user immersion into the training environment, the surrounding and interaction metaphors should be the same as during the real intervention. To this end, we replicated an OR in our lab, provided standard hysteroscopic tools for interaction, and generate a new virtual scene for every session. In this setting, the training starts, as soon as the trainees enter the OR, and ends when they leave the room.

Competency-Based Education↗
PubMed2006

Adverse reactions to latex products: preventive and therapeutic strategies.

Evidence-based infection control/exposure control practices are evolutionary in nature. Elements of historical note were first recorded with the suggestions of Lister for guidelines on aseptic procedures. Others, like Semmelweis, promoted the practice of hand washing by medical students and physicians prior to leaving autopsy suites and before entering the labor and delivery areas of hospitals. Halstead is credited with being the first to use surgical gloves in a clinical setting. While the use of latex surgical gloves became routine by the end of World War I, it wasn't until the adoption of universal precautions by the Centers for Disease Control in 1987 that the use of gloves was officially expanded to cover virtually all aspects of patient care. The ubiquitous use of latex gloves and other latex products in healthcare has resulted in a parallel increase in latex-associated adverse reactions. To provide for a safe environment for both oral healthcare providers and patients alike, clinicians must understand the basis for latex-related adverse reactions, recognize associated signs and symptoms, and initiate appropriate preventive and therapeutic strategies. The recommendations for preventing/minimizing latex allergy in the oral healthcare setting are based on current knowledge and a common sense approach to the problem. Evolving manufacturing technology and improvements in measurement methods (for latex proteins) may lead to changes in these recommendations in the future.

Anaphylaxis↗
PubMed1991

Circadian locomotor activity rhythms in Alzheimer's disease.

Circadian motor activity rhythms in 19 severely demented, institutionalized patients with Alzheimer's disease (AD) were evaluated with small, waist-worn electronic monitors which recorded 5-minute epochs for 48 to 72 hours. Controls were eight normal subjects of the same age (71 to 73 years) in a similar environment. As expected, computer-assisted analysis indicated more than twofold average increases in nocturnal activity and in the proportion of nocturnal to total daily activity in the AD patients. In patients (n = 8) with virtually constant pacing, daytime activity was markedly increased over that of normal controls; these "pacers" also had a significantly decreased amplitude of the circadian activity rhythm compared with controls. Moreover, AD patients showed a marked phase-delay, with individual afternoon maxima (acrophases) averaging 2.1 hours later than in controls (p less than 0.005). These findings quantitatively document clinical observations that AD patients, and especially a subgroup with pacing behavior, have markedly disturbed levels and modulation of daily locomotor activity. They accord with reports of altered circadian rhythms of endocrine and other physiologic parameters in such patients. Activity monitoring may represent a relatively simple, objective measure with which to characterize demented patients and to assess responses to treatment.

Aged↗
PubMed1987

Elevation of infiltrating mononuclear phagocytes in human colorectal tumors.

The distribution of infiltrating monocytes-macrophages and T-lymphocytes in 45 primary colorectal tumors and 8 metastatic lymph nodes has been investigated by immunoperoxidase labeling with monoclonal antibodies (MoAbs). The number of lymphoreticular cells observed in tumor tissue, staged according to Dukes classification, was compared with paired normal tissue and between staged groups by statistical analysis. T-lymphocytes were not significantly elevated above the normal in either Dukes B or C stage tumors, although the IL-2 receptor (MoAb Tac) was expressed by varying numbers of T-cells in both groups. Mononuclear phagocytes increased numerically in both Dukes B (1.5-fold, P-value less than .01) and Dukes C tumors (2.5-fold, P-value less than .001) as compared to those in the uninvolved gut. In addition, the number of both total (MoAbs 3.9, 24) and stimulated mononuclear phagocytes expressing the C3b receptor (MoAb E11) was greater in metastasizing than in nonmetastasizing tumors (P-value less than .01). Thus the T-cell-to-monocyte ratio was altered from 2:1 in normal tissue to 1:1 in advanced tumors. The stromal environment around tumor cells in lymph nodes was similar to that of the primary tumor, but there was a reduction in the proportion of cells expressing the C3b receptor; unlike the primary tumor, there was virtually no infiltration of the tumor epithelium. Although there is a significant alteration in the mononuclear phagocyte population within colorectal tumors, there is no histologic evidence for a cytotoxic role for these cells.

Antibodies, Monoclonal↗
PubMed1984

Helper T lymphocytes from xid and normal mice support anti-phosphocholine antibody responses with equivalent T15, 511, and 603 idiotypic composition.

We have examined the idiotypic composition of secondary adoptive transfer antibody responses to phosphocholine (PC) supported by KLH-primed helper T cells derived from normal mice or xid mice. CBA/N x BALB/c F1 male xid mice have diminished anti-PC responses and virtually undetectable levels of the T15 idiotype; xid mice do express the 511 and 603 idiotypes. Nonetheless, we find helper T cells derived from such mice are indistinguishable from T cells primed in a normal environment in their ability to cooperate with B cells producing anti-PC antibody bearing the T15, 511, or 603 idiotype markers. This result is in contrast to a previously published report from this laboratory. T cells from xid mice did support more IgG PFC than normal T cells, but serum IgG anti-PC antibody levels were similar in both groups. The IgM anti-PC response was predominantly of the T15 idiotype, whereas the 511 idiotype was associated with a minor fraction of IgG1 antibodies. The majority of the secondary IgG "anti-PC" antibody response bore none of the idiotypic markers associated with PC-binding myeloma or hybridoma antibodies, and was directed against phenyl-PC rather than PC. The phenomenon of T15 clonal dominance in the anti-PC response therefore is largely confined to the IgM response. We would conclude that the idiotype levels in the T cell priming environment do not influence the subsequent ability of such primed T cells to support anti-PC antibody responses.

Animals↗
PubMed1976

[Drug therapy of early-childhood minimal brain damage].

Drug therapy in a child with juvenile psychoorganic syndrome is only one part of a comprehensive therapeutic program in which the main emphasis is on training and education, which are sometimes accompanied by psychotherapy. In many cases drug therapy is totally unnecessary. It may however provide essential support for the efforts of educators and therapists and is sometimes the factor which renders these possible at all. Not all symptoms respond equally well: the best results are obtained in disorders of drive and often in psychogenic disorders which have developed on the basis of the psychoorganic syndrome. Promotion of personality development, which is virtually always retarded in the child with psychoorganic syndrome, remains the exclusive preserve of training. Drug administration has psychogenic as well as chemical effects. It depends to a large extent on the reaction of the environment to the fact that drugs are being given at all, and to the behavioral changes exhibited by the treated child. Drug effects are thus modified, and, with time, determined by the environment, and thus in many cases treatment is possible only on a short-term or (sometimes) periodic basis. Where treatment is on a long-term basis the danger of drug dependency must be borne in mind, since patients with psychoorganic syndrome are particularly exposed to the risk of addiction. For this reason care is necessary in administering amphetamine-type substances. These drug should not be prescribed from puberty onwards; previously initiated treatment with them should be terminated before purberty. It should however be pointed out that the results registered with amphetamines and drugs with similar effect can usually be obtained equally with drugs involving fewer risks in this respect.

Age Factors↗
PubMed1992

Identification of genetic factors contributing to heterosis in a hybrid from two elite maize inbred lines using molecular markers.

The use of molecular markers to identify quantitative trait loci (QTLs) affecting agriculturally important traits has become a key approach in plant genetics-both for understanding the genetic basis of these traits and to help design novel plant improvement programs. In the study reported here, we mapped QTLs (and evaluated their phenotypic effects) associated with seven major traits (including grain yield) in a cross between two widely used elite maize inbred lines, B73 and Mo17, in order to explore two important phenomena in maize genetics-heterosis (hybrid vigor) and genotype-by-environment (G x E) interaction. We also compared two analytical approaches for identifying QTLs, the traditional single-marker method and the more recently described interval-mapping method. Phenotypic evaluations were made on 3168 plots (nearly 100,000 plants) grown in three states. Using 76 markers that represented 90-95% of the maize genome, both analytical methods showed virtually the same results in detecting QTLs affecting grain yield throughout the genome, except on chromosome 6. Fewer QTLs were detected for other quantitative traits measured. Whenever a QTL for grain yield was detected, the heterozygote had a higher phenotype than the respective homozygote (with only one exception) suggesting not only overdominance (or pseudooverdominance) but also that these detected QTLs play a significant role in heterosis. This conclusion was reinforced by a high correlation between grain yield and proportion of heterozygous markers. Although plant materials were grown and measured in six diverse environments (North Carolina, Iowa and Illinois) there was little evidence for G x E interaction for most QTLs.

Crosses, Genetic↗
PubMed2005

Pliocene large-mammal assemblages from Northern Chad: sampling and ecological structure.

Numerous Pliocene large-mammal assemblages have been discovered in Chad over the last decade. They offer a unique opportunity to understand the settings in which important chapters of Hominid evolution took place in Central Africa. However, it is crucial to first investigate both sampling and taxonomic homogeneity for these Chadian assemblages because they occur over large sectors in a sandy desert that offers virtually no stratigraphic section. Using cluster analysis and ordination techniques, we show that the three Pliocene sectors from Chad are homogeneous and adequate sampling units. Previous stable isotope analyses on these assemblages have indicated that the environment became richer in C(4) plants between approximately 5.3 and 3.5-3 Ma. To test whether this environmental change has affected the structure of palaeo-communities, we assigned body mass, trophic and locomotor eco-variables to mammal species from the three sectors. Statistical analysis shows that the overall ecological structure of the assemblages is not linked with the opening of the plant cover, and eco-variables show no temporal trend from the oldest sector to the youngest. For example, there is no significant change in the relative diversity of grazing and browsing taxa, although mixed feeders are less diversified in the youngest sector than in the preceding one. This pattern apparently does not result from potential biases such as methodological artefacts or taphonomic imprint. Instead, it seems that local heterogeneous environmental factors have played a major role in shaping the ecological spectrum of Chadian mammal palaeo-communities during the Pliocene.

Animals↗
PubMed2001

Primary adult human bone cells do not respond to tissue (continuum) level strains.

Bone adapts to its mechanical environment, and, since the late 1800s, investigators have presumed that this adaptation relates to strain magnitude. Indeed, overwhelming evidence supports the view that either strain or some strain-related quantity stimulates bone adaptation or remodeling. Virtually all investigators, implicitly or explicitly, assume that the level of strain magnitude responsible for bone adaptation is that measured by strain gauges in vivo (i.e., 100-2500 microstrain) and that bone cells are directly deformed by strained matrix. We present evidence that bone cell deformation in this range does not cause bone adaptation. First, bone cells in vitro typically do not respond to average (continuum) levels of strain magnitude. Second, bone cells in vitro do respond to fluid flow-induced shear stresses in these ostensible physiological ranges. Third, in vivo strain magnitudes presumed to stimulate remodeling reflect only averages, and not local peaks, which are 2-15 times higher. Thus, we hypothesize that sensing cells do not respond to levels of strain presumed to be physiological.

Adaptation, Physiological↗
PubMed2003

[Virtual organization in the digital age of radiology - principle and solution for radiologic research?].

The research project "VICORA - Virtual Institute for Computer-Assisted Radiology", funded by the German Federal Ministry of Education and Research, was initiated in the year 2000. Its virtual organization brings together physical science, engineering, information technology, clinical radiology and the medical technology industry. In the German radiology research domain VICORA serves as a model for interdisciplinary collaboration for the changing radiology paradigm illustrated by a "radiologycube". The project does not only aim at scientific goals but also considers the infrastructure, components and human resource management within a virtual organization. The common rapid prototyping platform ILAB 4 ensures user-friendly and time-efficient software that assists with the routine radiology work-flow including full DICOM functionality. By offering a new work environment and collaborative culture based on telematics and knowledge exchange in radiology research, VICORA overcomes limitations of traditional research organization.

Diagnosis, Computer-Assisted↗
PubMedDate not supplied

The principle of a threshold dose in chemical carcinogenesis.

The nature of at least three stages in carcinogenesis by chemical agents justifies the existence of a threshold dose: (1) a cytoplasmic stage during which most carcinogenic molecules are eliminated, (2) a nuclear stage during which certain DNA lesions are repaired and therefore cannot help to bring about mutations, and (3) an extracellular stage during which mutations are controlled for a long time by positive or negative epigenetic factors. All these findings are very difficult to collate. Since threshold doses cannot be detected by direct experimentation, the knowledge that a threshold exists is of little practical use and does not much alter the data permitting extrapolation of the results obtained with high doses of carcinogens. At the theoretical level only, this conclusion renders obsolete the opinion that all carcinogenic agents should be completely eliminated from our environment, and also the view that DNA needs only one hit from such an agent for a carcinogenic effect to be produced. The above conclusion also provides a more rational basis for the concept of a 'virtually safe dose' (VSD) or 'allowable daily intake' (ADI).

Alkylating Agents↗
PubMed1991

Spectroscopic limits to an extragalactic far-ultraviolet background.

We use a spectrum of the lowest intensity diffuse far-ultraviolet background obtained from a series of observations in a number of celestial view directions to constrain the properties of the extragalactic FUV background. The mean continuum level, IEG = 280 +/- 35 photons cm-2 s-1 angstrom-1 sr-1, was obtained in a direction with very low H I column density, and this represents a firm upper limit to any extragalactic background in the 1400-1900 angstroms band. Previous work has demonstrated that the far-ultraviolet background includes (depending on a view direction) contributions from dust-scattered Galactic light, high-ionization emission lines, two-photon emission from H II, H2 fluorescence, and the integrated light of spiral galaxies. We find no evidence in the spectrum of line or continuum features that would signify additional extragalactic components. Motivated by the observation of steep BJ and U number count distributions, we have made a detailed comparison of galaxy evolution models to optical and UV data. We find that the observations are difficult to reconcile with a dominant contribution from unclustered, starburst galaxies at low redshifts. Our measurement rules out large ionizing fluxes at z = 0, but cannot strongly constrain the QSO background light, which is expected to be 0.5%-4% of IEG. We present improved limits on radiative lifetimes of massive neutrinos. We demonstrated with a simple model that IGM radiation is unlikely to make a significant contribution to IEG. Since dust scattering could produce a significant part of the continuum in this lowest intensity spectrum, we carried out a series of tests to evaluate this possibility. We find that the spectrum of a nearby target with higher NH I, when corrected for H2 fluorescence, is very similar to the spectrum obtained in the low H I view direction. This is evidence that the majority of the continuum observed at low NH I is also dust reflection, indicating either the existence of a hitherto unidentified dust component, or of a large enhancement in dust scattering efficiency in low-density gas. We also review the effects of an additional dust component on the far-infrared background and on extragalactic FUV observations. We conclude that dust reflection, combined with modest contributions from H II two-photon emission and from the integrated light of late-type galaxies, may account for virtually all of the FUV background in low H I column density directions.

Astronomical Phenomena↗