Purification of Giardia muris trophozoites by using nylon fiber columns.

A method is described for purification of large quantities of Giardia muris trophozoites from the small intestine of the mouse by using density layer centrifugation and nylon fiber columns. Centrifugation of trophozoites obtained from the small intestine on Metrizamide, specific gravity 1.10, followed by incubation on a nylon fiber column at 37 degrees C for 120 min, yielded up to 15 X 10(6) viable purified trophozoites per infected mouse.

Continuous quality improvement and the education of the generalist physician.

The new health care environment--centered on patients, focused on health, and managed by generalists--requires new competencies for the generalist physician. Among these are knowledge and skills for the continuous improvement of health care. In many areas, generalist physicians already use quality improvement methods and principles to improve the health and health care of their communities. Efforts to teach medical students and residents to improve quality continuously in health care are beginning. Early lessons are: (1) quality improvement is most effectively learned in the context of real work; (2) initial emphasis must be on the basics; (3) the focus is on the needs of those we serve; (4) interdisciplinary skills are essential and best learned during clinical training; and (5) the best learning environment for future generalist physicians, one which results in optimism about the future and the ability to make things better, is an environment that is continuously improving.

A strategy for coping with change: an affiliation between a medical school and a managed care health system.

Case Western Reserve University School of Medicine (CWRU), a private research-focused medical school, and Henry Ford Health System (HFHS), an integrated health system with a preponderance of managed care, have established a formal, broad affiliation that includes substantial commitments that bind the two organizations. Among them are formal full-time faculty appointments at CWRU for qualified professional staff of HFHS, designation of an associate dean for CWRU at HFHS, election of HFHS faculty to key medical school committees such as admission, curriculum, and promotions and tenure, and the commitment of funds to the affiliation by both organizations: a grant from HFHS to CWRU for curriculum development, and investment from CWRU to HFHS. The alliance of two such organizations is made complex by a number of issues. They include differences of institutional cultures as well as traditional issues in academic health centers such as departmental authority over curriculum and faculty appointments, competition for academic preeminence, and competition among hospitals for patients. The affiliation was facilitated by shared commitments to education, agreement on the need to adapt student education to the emerging managed care environment, a shared commitment to health services research, investment in the concept that learners add value to a health care delivery setting, and the desire to develop graduates with knowledge of practice in managed care. The authors conclude that medical schools and integrated managed care health systems gain sufficiently from such an affiliation that the investment of time, effort, and resources is readily justified.

Immunological signals which control T cell responses.

A number of identifiable immunological parameters can influence the elicitation and regulation of antigen-specific inflammatory responses to immunogenic epitopes. Injection of antigen in vivo can lead to the activation of type IV hypersensitivity responses, or to the induction of immunological tolerance to that antigen. We have used the hapten trinitrophenol as a model system for studying the factors which influence the generation and regulation of hypersensitivity responses to immunogenic epitopes in vivo. The generation of hypersensitivity or tolerance to trinitrophenyl depends on a number of immunological factors, including the form of the antigen, the route of immunization, and the presence of immune complexes of antibody and antigen on the surface of the antigen-presenting cell. Immunization with trinitrophenyl resulting in unresponsiveness can be the result of either the inability to prime inflammatory cells in vivo or the induction of suppressor T cells.

A strategy for improvement in care at the end of life: the VA Faculty Leaders Project.

Given the commitment of the Veterans Health Administration (VA) to excellent, compassionate end-of-life and palliative care and the VA's extensive system of academic affiliations with the nation's medical schools, there may exist an opportunity to accelerate acceptance of state-of-the-art training for improved care for dying patients. Accordingly, the VA has initiated a project to develop strategies for implementation of benchmark curricula for end-of-life and palliative care. With the support of the Robert Wood Johnson Foundation, this initiative has been implemented in 30 internal medicine residency training programs affiliated with the VA nationally.

Cypermethrin pour-on for the control of ticks (Ixodes ricinus) on sheep.

Trials were carried out on 11 farms to assess the effectiveness of 2.5 per cent w/v cypermethrin pour-on for the control of ticks on sheep. Treatment at the rate of 5 ml/10 kg bodyweight gave 92 per cent control of ticks on ewes for up to nine weeks and 88 per cent control on lambs for up to eight weeks.

Safety and efficacy of a novel tartar control dentifrice containing 3.3% pyrophosphate: a controlled six-month clinical trial.

This study was undertaken to establish the tartar control efficacy and long-term safety of a new tartar control dentifrice that was formulated to enhance aesthetics and consumer acceptability. In a partially randomized, examiner-blind clinical trial, the experimental dentifrice, Crest MultiCare with 3.3% pyrophosphate, was compared to two currently marketed control dentifrices, Crest Regular Paste or Crest Tartar Protection Paste with 5.0% pyrophosphate. The eight-month trial model included a two-month pretest period to establish calculus formation after prophylaxis, followed by a six-month test period to evaluate efficacy and safety. Following the pretest period, 456 subjects were allocated to one of the three treatment groups and then monitored for calculus accumulation. After three and six months' test product use, the Crest MultiCare group experienced reductions in calculus accumulation of 28.9% and 32.3%, respectively compared to the regular control dentifrice. Over the six-month observation period, the experimental tartar control and the marketed tartar control dentifrices were comparable on adverse event frequency, type or severity, and no subject discontinued treatment due to an oral soft tissue adverse event. In this partially randomized and controlled six-month clinical trial, this new dentifrice exhibited tartar control efficacy, with a comparable overall safety profile to a marketed tartar control dentifrice.

Breath effects of three marketed dentifrices: a comparative study evaluating single and cumulative use.

This randomized and controlled, examiner blind, parallel group study was undertaken to evaluate the efficacy of three commercial dentifrices on breath malodor. A total of 384 healthy adult subjects with oral malodor were randomized to one of four brushing groups, using either an antimicrobial dentifrice containing 0.45% stannous fluoride, an antitartar dentifrice containing 0.243% sodium fluoride and 5% pyrophosphate, an antimicrobial dentifrice containing 0.24% sodium fluoride and 0.30% triclosan/copolymer, or bottled distilled water which served as the negative experimental control. Breath quality was evaluated over a five-day period by second-person organoleptic grading and measurement of volatile sulfur levels. Following treatment, adjusted mean organoleptic scores and volatile sulfur levels were lowest for the stannous fluoride dentifrice group, with this group exhibiting superior breath quality compared to the negative control at three hours after a single brushing, and again at all cumulative use time points. While all test dentifrices showed some activity, only stannous fluoride had a second-person breath benefit. Breath effects for the other two dentifrices were limited to reductions in volatile sulfur levels at hours 99 and 104 for the antitartar sodium fluoride pyrophosphate dentifrice, and at hour 99 only for the antimicrobial sodium fluoride triclosan/copolymer dentifrice. This research establishes the comparative breath efficacy of three commercial dentifrices in a study model that may prove relevant for other dentifrice clinical trials.

VA aligns health professions education with healthcare priorities.

In 1997, the Veterans Health Administration constituted the Associated Health Professions Education Review Committee to provide recommendations for its associated health training programs. The Committee recommended that support for the 54,000 trainees in over 45 non-physician disciplines that train every year in VA facilities be allocated based on patient-focused criteria that emphasize the VA's healthcare priorities. Such priorities include accessible primary care, geriatrics, treatment of substance abuse, chronic care, and rehabilitation. The Committee also placed a high priority on disciplines that demonstrate inter-professional strategies for healthcare delivery and training. Educational institutions and disciplines that address these needs in innovative ways will find opportunities for clinical training in VA settings.

Effect of water treatment residuals on soil phosphorus, copper and aluminium availability and toxicity.

Water treatment residuals (WTRs) are produced by the treatment of potable water with coagulating agents. Beneficial recycling in agriculture is hampered by the fact that WTRs contain potentially toxic contaminants (e.g. copper and aluminium) and they bind phosphorus strongly. These issues were investigated using a plant bioassay (Lactuca sativa), chemical extractions and an isotopic dilution technique. Two WTRs were applied to an acidic and a neutral pH soil at six rates. Reductions in plant growth in amended soils were due to WTR-induced P deficiency, rather than Al or Cu toxicity. The release of potentially toxic Al from WTRs was found to be mitigated by their alkaline nature and pH buffering capacity. However, acidification of WTRs was shown to release more soluble Al than soil naturally high in Al. Copper availability was relatively low in all treatments. However, the lability of WTR-Cu increased when the WTR was applied to the soil.