Factors associated with occupational exposure and compliance with universal precautions in an urban school district

Factors associated with occupational exposure and universal precautions (UP) compliance were assessed among employees in one urban school district. Half of the employees surveyed reported responding to bleeding injuries and cleaning blood or other body fluids (e.g., vomit, urine) during the previous school year. Also, 1 in 4 custodians and 1 in 10 teachers/teacher's aides had direct contact with blood or body fluids without protection. In multivariate logistic regression analyses, direct contact was most likely among secondary school employees in unpredictable situations who did not have protective equipment or comply with UP. UP compliance was greater among those who had protective equipment available and felt self-confident. Self-confidence was associated with having received training or protective equipment. Routine communications between administrators and employees, staff training, provision of protective equipment, and exposure incident monitoring are essential to effective implementation of UP policies in schools and work settings where occupational exposure could occur.

Bacterial vaginosis, ethnicity, and the use of genital cleaning agents: a case control study

BACKGROUND AND OBJECTIVES

Bacterial vaginosis and vaginal douching are both reported to be more common in African-American and Caribbean than white women. It is also thought that douching alters the vaginal milieu. This study was conducted to examine associations between genital cleaning practices, bacterial vaginosis, and ethnic group.

STUDY DESIGN

Case-control study of 100 women with bacterial vaginosis, diagnosed by Nugent's criteria, and 100 women without bacterial vaginosis attending a sexually transmitted diseases clinic in an ethnically heterogeneous inner-city area in London, England.

RESULTS

Bacterial vaginosis was more common among black Caribbean than white women (OR, 2.1; 95% CI, 1.1-4.1). Vulval use of bubble bath or antiseptic solutions and douching with proprietary or homemade solutions were significantly more common in women with bacterial vaginosis than without. After controlling for use of vulval and vaginal antiseptics and bubble bath, douching, and a history of bacterial vaginosis, there was no ethnic difference in the occurrence of the condition (adjusted OR, 1.1; 95% CI, 0.5-2.5).

CONCLUSIONS

Ethnic differences in genital hygiene behaviors can explain a twofold increase in the risk of bacterial vaginosis in black Caribbean compared with white women. The role of vulval and vaginal cleaning practices in the development of bacterial vaginosis should be examined further in longitudinal or randomized controlled studies.

Virtual reality and telemedicine: exploring advanced concepts

Virtual reality (VR) has provided a new methodology for interacting with information. Since telemedicine is principally involved with transmitting medical information, VR has the potential to enhance the telemedicine experience. The two principle ways in which VR can be applied are as an interface, which enables a more intuitive manner of interacting with information, and as an environment that enhances the feeling of presence during the interaction. Since there are no current clinical applications of VR in the telemedicine experience, this report reviews concepts and experiences with the potential to enhance the delivery of telemedicine.

Microgravity effects on water flow and distribution in unsaturated porous media: analyses of flight experiments

Plants grown in porous media are part of a bioregenerative life support system designed for long-duration space missions. Reduced gravity conditions of orbiting spacecraft (microgravity) alter several aspects of liquid flow and distribution within partially saturated porous media. The objectives of this study were to evaluate the suitability of conventional capillary flow theory in simulating water distribution in porous media measured in a microgravity environment. Data from experiments aboard the Russian space station Mir and a U.S. space shuttle were simulated by elimination of the gravitational term from the Richards equation. Qualitative comparisons with media hydraulic parameters measured on Earth suggest narrower pore size distributions and inactive or nonparticipating large pores in microgravity. Evidence of accentuated hysteresis, altered soil-water characteristic, and reduced unsaturated hydraulic conductivity from microgravity simulations may be attributable to a number of proposed secondary mechanisms. These are likely spawned by enhanced and modified paths of interfacial flows and an altered force ratio of capillary to body forces in microgravity.

Extending the limits: minimally invasive surgery

Minimally invasive technology is being applied to an increasing number of surgical procedures. It remains to be seen which techniques will eventually become a 'gold standard' as has the laparoscopic cholecystectomy, and which will fall by the wayside. In the meantime, anesthesiologists must be aware of the unique requirements and complications of laparoscopic surgery.

Effects of carbaryl, permethrin, 4-nonylphenol, and copper on muscarinic cholinergic receptors in brain of surrogate and listed fish species

We investigated the regulation of the muscarinic cholinergic receptor (MChR) in brain from seven species of fish, two surrogates and five threatened or endangered species exposed to a series of chemicals as a measure of compensatory response among species. Fish were classified as either cold water (rainbow trout-surrogate, apache trout, lahanton trout) or warm water (fathead minnow-surrogate, razorback sucker, bonytail chub, colorado squawfish) and were exposed to chemicals shown to affect cholinergic pathways (carbaryl and permethrin) and two chemicals whose relationships to the cholinergic system is less clear (4-nonylphenol and copper). Downregulation of MChR occurred in all warm water species, except colorado squawfish, and at carbaryl concentrations similar to those causing downregulation observed in rainbow trout. Permethrin exposure resulted in downregulation in fathead minnow and razorback sucker, but the concentrations required for observation of this phenomenon were much greater than observed in cold water species. Copper exposure caused a decrease in brain MChR in rainbow trout and apache trout, whereas 4-nonylphenol exposure resulted in a decrease in brain MChR in all three cold water species. Our results indicate that surrogates are useful in assessing sublethal physiological responses to chemicals with a known mechanism of action such as carbaryl and support use of surrogates for assessing physiological responses to chemicals with diverse, less clear mechanisms of action.

Human immune cells mediate catecholamine secretion from adrenal chromaffin cells

OBJECTIVES

To determine the ability of human mononuclear cells to produce factors that cause catecholamine secretion from adrenomedullary chromaffin cells; to determine conditions that stimulate mononuclear cells to produce such factors; and to compare these results with catecholamine secretion in response to the cytokines interleukin (IL)-1 and IL-2.

DESIGN

Randomized, controlled, prospective study using in vitro conditions.

SETTING

University research laboratory.

SUBJECTS

Human mononuclear cells and porcine chromaffin cells.

INTERVENTIONS

Circulating human mononuclear cells were isolated and cultured overnight in RPMI media. Cell-free media from these cultures (conditioned media) were then tested for the ability to cause epinephrine secretion from porcine chromaffin cells. Mononuclear cells were stimulated with phytohemagglutinin or by mixing cells from two different individuals while suppression was tested with dexamethasone. Catecholamine secretion in response to IL-1 and IL-2 (50 and 500 units/well, respectively), or nicotinic agonist dimethylphenylpiperazinium (10 microM, which mimics the action of acetylcholine), was tested for comparison.

MEASUREMENTS AND MAIN RESULTS

Isolated porcine chromaffin cells had stable catecholamine content at the time of secretion measurements, and catecholamine release from cells into the media was measured using electrochemical detection after high-performance liquid chromatography separation. Catecholamine secretion was expressed as a percentage of the total cellular content. Epinephrine secretion due to human conditioned media was 6.9 +/- 1.0% compared with 1.4 +/- 0.6% for control media (p < .05) and 14.6 +/- 3.3% for dimethylphenylpiperazinium (p < .05). Epinephrine secretion with conditioned media from mixed cells (mixed leukocyte reaction) was 16.6 +/- 1.2%, which was higher than the epinephrine secretion caused by media from a single donor (6.9% +/- 1.0, p < .001). Pretreatment with dexamethasone inhibited the formation of bioactive products from mixed mononuclear cell preparations. Cytokines IL-1 and IL-2 did not stimulate chromaffin cell epinephrine secretion above background release with control media incubation. In all cases, norepinephrine secretion was similar to that of epinephrine, and results are included in all figures.

CONCLUSIONS

Factors released from human immune cells can mediate epinephrine and norepinephrine release from adrenomedullary cells through a nonneural mechanism. Such immune cell factor release can be modulated by immunostimulation and steroid suppression. Release of such factors in vivo may contribute to increased circulating epinephrine in response to infectious challenge and may be an important factor in the critically ill patient.

Why not the best for the chronically ill?

Premium adjustors to neutralize risk selection among health plans are the weakest component in the technology for assuring competitive markets. It will be many years before we have adjustors adequate to free health plans to invest in and market improved managed care to predictably high-cost chronically ill persons. For want of a fair premium, health plans are driven by risk selection to underinvest in and otherwise "demarket" care to these very employees and beneficiaries whose costs and care most need to be managed. To achieve best value for the chronically ill, large employer coalitions, Medicare, and Medicaid should consider radical new approaches, such as establishing separate prices for care to people with specific chronic conditions and purchasing such care both from health plans and directly from provider systems.

Otolaryngology in the information age: enabling technologies for the future of surgery. Enabling technologies for the future of surgery

Enabling technologies for the future, whether exemplified by endoscopic, minimally invasive, or microdexterity systems or surgical and nonsurgical image-guided procedures, continue with an evolution so rapid that before one change has been accepted and perfected, another even more dramatic change promises to replace it. These information-based surgical and procedural interventions are just now becoming accepted standards of surgical, radiologic, and medical practice, and yet the promise of more advanced technologies blurs even these new boundaries, constantly redefining the concept of "surgery." It is essential that otolaryngologists, as part of the broader spectrum of physicians, understand these changes and prepare to adapt and improve each and every one of their technical and cognitive skills.

Capitated risk-bearing managed care systems could improve end-of-life care

Capitated or salaried managed care systems offer an important opportunity to provide high quality, cost-effective end-of-life care. However, capitated healthcare delivery systems have strong incentives to avoid patient populations in need of such care. Care currently provided at the end of life in fee-for-service practice is commonly deficient, with high rates of avoidable pain and other burdens. Only hospice offers a better track record, yet access to hospice is limited, and length of stay is short. Traditional staff- or group-model managed care plans, with their emphasis on prevention, patient education, cost efficiency, service coordination, and integrated provider networks, present a dynamic set of conditions and organizational structures that would support real change. Advantages derived from managed care systems providing quality end-of-life care include coordinated care across delivery sites, interdisciplinary teams, integrated services, and opportunities to develop innovative care programs, service arrays, utilization controls, and accountability for care standards. We propose a special comprehensive system of managed care, which we call MediCaring, for seriously ill persons nearing the end of life. MediCaring would encompass the best elements of palliative care within a managed care structure: comprehensive, supportive, community-based services that meet personal and medical needs, a focus on patient preferences, symptom management, family counseling, and support. Other programs, such as hospice, have shown that continuity and coordinated care, financed through a capitated payment and directed at a special population, are both feasible and effective. There are obstacles to improving care at the end of life. Managed care systems, like most of medical care, have largely ignored the terminally ill patient. Current financing arrangements make it financially undesirable for insurers to recruit or retain the very sick; very ill patients can be costly over a prolonged time. In addition, inertia and habit inhibit change, and there are few criteria by which to judge whether care at the end-of-life is "good." Nevertheless, capitated or salaried managed care systems committed to enhanced end-of-life care seem well positioned to achieve it if payment reimbursements were revised to encourage this end.

Laparoscopic surgery. Transition to the future

The twenty-first century will usher in a fundamentally new approach to the practice of medicine. It will be based heavily on information technologies, broadly defined as the devices that acquire information; those that process, transmit, and distribute information; and those that use information to provide therapy. Although conventional surgery will continue to have a presence, there will be radically different surgical approaches and technologies that may become the predominant form of surgery. The medical record may become a three-dimensional visual representation of the individual patient (like the Visible Human Project), which can be the vehicle that integrates the entire spectrum of health care. Examples of the technologies and infrastructures that support this new approach to medicine are discussed and illustrated, with emphasis on how technologies improve individual patient care.

Affordable health benefits for workers without employer coverage

With 42 million individuals lacking health insurance in 1996, an increase of 1.1 million uninsured from the previous year, new initiatives to deal with health insurance problems merit a high priority among domestic policy initiatives. This paper examines the opportunities for assisting full-time workers (and their families) who do not receive employer-paid health insurance-a group that now includes 49 million individuals-by using three policy tools that Congress and President Clinton have already agreed to use in recent healthcare legislation: (a) equitable tax assistance; (b) market reforms; and (c) competition among health plans that offer economical benefits. Estimates for a model plan illustrate that such strategies could make decent private health insurance more affordable and more accessible for workers and their families who want to purchase it; family insurance protection, with guaranteed issue of insurance and large-group-rated premiums, could be offered at potential savings of 42% (or more). Premiums for worker's coverage, after tax assistance, would be below $1,200 per year, i.e., less than 60 cents per hour. These market-oriented reforms can be accomplished with a limited government role, and, after start-up costs, ongoing federal expenses would be modest, predictable, and controllable. When combined with the new $24 billion child health initiative to assist low-income families, the proposed plan would provide considerable progress toward universal access to affordable insurance coverage.

A strategy and demonstration for integrated biotechnology information

Bioinformatics has developed as a key discipline to support science. Integrated access to the various new and established information resources is a key requirement for their future utility. A strategy for this integration has been developed and is being demonstrated to a core group of European users.

A capillary-driven root module for plant growth in microgravity

A new capillary-driven root module design for growing plants in microgravity was developed which requires minimal external control. Unlike existing systems, the water supply to the capillary-driven system is passive and relies on root uptake and media properties to develop driving gradients which operate a suction-induced flow control valve. A collapsible reservoir supplies water to the porous membrane which functions to maintain hydraulic continuity. Sheet and tubular membranes consisting of nylon, polyester and sintered porous stainless steel were tested. While finer pore sized membranes allow greater range of operation, they also reduce liquid flux thereby constraining system efficiency. Membrane selection should consider both the maximum anticipated liquid uptake rate and maximum operating matric head (suction) of the system. Matching growth media water retention characteristics to the porous membrane characteristics is essential for supplying adequate liquid flux and gas exchange. A minimum of 10% air-filled porosity (AFP) was necessary for adequate aeration. The capillary-driven module maintained hydraulic continuity and proper gas exchange rates for more than 80 days in a plant growth experiment.

Particulated growth media for optimal liquid and gaseous fluxes to plant roots in microgravity

An important and yet relatively under researched area of plant growth in microgravity, deals with the rooting environment of plants. A comprehensive approach for selecting the physical characteristics of root growth media which optimizes the dynamic availability of water and dissolved nutrients, and gases to plant roots was developed and tested. Physically-based and parametric models describing the relationship between content and fluxes of liquids and gases were used to cast a multi-objective optimization problem. This methodology reveals that a medium's ability to supply liquid and gas fluxes optimally is dependent upon physiological target values, system operation limits and root module design which dictate the medium's range of soil water characteristic and particle size distribution. Optimized media parameters designate a particle size distribution from which a particulated growth media was constructed and matched to the optimized media parameters. This methodology should improve the selection of optimal media properties for plant growth in microgravity as well as other porous media applications.

Resolution of abnormal MR signal intensity in patients with stress fractures of the femoral neck

OBJECTIVE

The purpose of this study was to describe the natural evolution of abnormal MR signal intensity after the diagnosis of a stress fracture of the femoral neck and to ascertain the time to resolution of that abnormal signal intensity.

SUBJECTS AND METHODS

Ten patients who had been previously diagnosed with stress fractures of the femoral neck after positive MR scans of the hip were examined with MR imaging at regular intervals. In each patient T1-weighted and short inversion time inversion recovery (STIR) sequences were obtained until the abnormally bright, diffuse MR signal intensity (representing edema) disappeared from the STIR images. Time to resolution was correlated with each patient's age and presence or absence of a fatigue line on MR imaging. Statistical analysis was done using Fisher's exact test.

RESULTS

Edema resolved in seven patients within 3 months of initial diagnosis, in two patients within 6 months, and in the remaining patient within 12 months. We found no statistically significant correlation between time to resolution and patient age or the presence of a fatigue line on MR imaging. Residual sclerosis occurred in five patients, all of whom had a fatigue line. Two of these patients developed bright T1 signal (fatty marrow conversion) around the area of sclerosis. In the remaining three patients, STIR images revealed a brightened fatigue line, which we presumed was caused by granulation tissue.

CONCLUSION

In this study, 90% of patients showed resolution of abnormal MR signal intensity on STIR imaging within 6 months of the initial diagnosis of stress fracture of the femoral neck. Such data may prove helpful in examining patients with recurrent symptoms who undergo repeated MR scanning. When an abnormally bright, diffuse MR signal intensity on STIR imaging is seen more than 6 months after an original injury, such abnormal signal intensity is likely to represent new injury.

Consumers, gag rules, and health plans: strategies for a patient-focused market

The "gag rule" controversy has become a symbol of new tensions and changing relationships among patients, physicians, and health plans. This paper offers a consumer-focused analysis of these fundamental issues from the point of view of a patient with a chronic illness. It starts with a case study of a specific individual and then considers the systemic incentives and other factors that lead to conflicts among patients, physicians, and health plans. This consumer focus invites the reader to consider managed care with the following question in mind: "What would you want for yourself it you were the patient?" The paper suggests that many private-sector initiatives, as well as government actions, could contribute to a better health care market. Among the reform strategies discussed are (a) professional responsibility and private-sector standards, (b) consumer assistance, and (c) government regulation. All of us, including persons with chronic illness, need a consumer-focused health system. So, too, do physicians and health plans that want to provide excellent care for all of their patients.

Chromaffin cell epinephrine secretion mediated by a macrophage peptide: the role of endotoxin

Recent studies show that mononuclear cells release a small peptide (molecular weight < 3,000) that stimulates chromaffin cell epinephrine secretion (1). The present study demonstrates that endotoxin (ETX) enhances this mononuclear cell-mediated epinephrine secretion and examines the potential mechanism for regulation of this peptide. Mononuclear cells from bovine spleen were cultured 24 h in serum-free media after which the supernatant (conditioned media, CM) was harvested and filtered to remove molecules with a molecular weight greater than 3,000. In vitro epinephrine secretion from bovine chromaffin cells was used as a test system and CM-secretion expressed as a percentage of total cell content. ETX challenge (1 microgram/mL) of mononuclear cell cultures significantly enhanced bioactivity of CM (control-CM = 11.8 +/- .7, ETX-CM = 17.7 +/- 2.8). Separation of cell populations by adherence to plastic revealed that T cell and/or B cell populations were the main source of the bioactive peptide(s) in unstimulated cell cultures (T/B cell = 12.9 +/- .7, M phi = 6.2 +/- .8). In contrast, ETX induced significant bioactive peptide release from the macrophage population (M phi = 6.2 +/- .8, ETX-M phi = 15.9 +/- 2.8). Polyacrylamide gel analysis revealed a small peptide in nonadherent cell CM that was present only in ETX-challenged macrophage cultures. Additionally, data are presented that demonstrate a correlation between CM bioactivity and protease activity in CM. Proteases secreted from mononuclear cells in response to ETX is hypothesized to cleave the bioactive peptide from a larger "parent" protein. This peptide may play a role in the elevation of plasma catecholamines observed in the setting of critical injury and illness and contribute to development of the systemic inflammatory response syndrome (SIRS) and subsequent shock states.

Virtual reality surgical simulation and otolaryngology

Large-scale flight simulation was pioneered in the 1940s to help meet the training requirements and demand for pilots in World War II. Flight simulators have been effective for training, evaluating, and certifying military and commercial pilots. Accurate scenarios have been developed that allow pilots in training to gain experience without the risk and expense of learning while in flight. The research in aviation simulation suggests a transfer effectiveness ratio of 0.48. This means that 1 hour in the simulator saves a half hour in the air. Because of the successful use of flight simulation as a training technique, computer-based simulators are now used in a variety of domains.