Helminth log reduction values for recycling water from sewage for the protection of human and stock health

The LRVs required to decrease HE concentrations in raw sewage to an acceptable level to manage the risk to human and livestock health were determined. An LRV of 3.0 was required to meet the HBT of 1 μDALY pppy in SE Australia where human helminth infections are not endemic. In comparison, a similar exposure volume and LRV in endemic regions would result in a HBT of 100 μDALY pppy. The risks posed by cattle- and pig-related helminths were also managed acceptably with the treatment of sewage providing an LRV of 3.0. New design equations were derived to determine LRVs based on hydraulic residence times (HRTs) in an activated sludge plant (ASP) and lagoons. The new equation for lagoons indicated that an LRV of 3.0 could be achieved with a HRT of 18 days or less.

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.

Habitat inventory at a regional scale: a comparison of estimates of terrestrial Broad Habitat cover from stratified sample field survey and full census field survey for Wales, UK

Estimates of terrestrial Broad Habitat cover for Wales from the Countryside Survey 2000 stratified sample field mapping programme in Britain are compared with the findings of a full census field mapping project, the Habitat Survey of Wales. The Countryside Survey sampling regime comprised a stratified random sample of 1 km squares [corrected] covering <0.5% of the land surface. Comparative assessment indicates that although few of the sample-derived estimates for individual Broad Habitats are within 30% of the full census survey results, relative extents accord with data from the complete census survey for all Broad Habitats apart from Arable & Horticultural. The accuracy of this estimate is improved when the national boundary of Wales is taken into account in the sample stratification scheme. It is suggested that cultural land-use differences between countries render cropland habitat extent less predictable from physical environmental parameters than semi-natural habitat extent. It is also shown that the precision of sample-derived cover estimates is influenced by habitat pattern: the error term associated with habitats of broadly equal extent is greater for those with the most clumped distributions.

Repeatability of Phase 1 habitat survey

As the major part of a Habitat Survey of Wales, over 80% of the land surface was surveyed in the field between 1987 and 1997 using the Phase 1 method. A resurvey of 294 randomly selected points was carried out during the early stages to audit the quality of the data being collected, leading to the development of a set of recommendations for the surveyors to improve the consistency and accuracy of habitat mapping. Recent studies have indicated a high level of discrepancy between organisations in field habitat mapping using the Phase 1 method. The findings of the Phase 1 audit in Wales are presented here to show the level of repeatability that was achieved within an organisation. There was 76% correspondence in habitat mapping between 'surveyor' and 'assessor' at the level of individual Phase 1 habitat classes. The degree of repeatability varied according to habitat strata: it was highest for modified land cover types (88%), lowest for semi-improved types (56%) and intermediate for semi-natural types (75%). An overall estimate of the repeatability of Phase 1 survey in the study area of 83% was obtained by weighting the figures for the three strata by the proportion of land area occupied by each stratum. This figure increased to 85% when habitats were amalgamated into Broad Habitat groups. These results are considerably better than those reported by studies of consistency between organisations. Most of the discrepancies between surveyor and assessor were caused by differences in habitat identification. However, at almost two thirds of the points where such a difference occurred, the assessor noted that the vegetation was transitional or borderline with that mapped by the surveyor.

Adaptation of soil biological nitrification to heavy metals

The adaptive response of soil biological nitrification to Zn and Pb was assessed using an in situ method we have developed. The method is based on reinoculating a sterilized metal contaminated soil with the same soil that is either uncontaminated or has been incubated with metal. This approach excludes the potentially confounding effects of metal aging reactions in soils. We found added Zn concentrations which gave rise to a decrease in nitrification to 50% that of the uncontaminated soil (i.e. EC50) of 210 mg/kg for communities not previously exposed to Zn and 850 mg/kg for communities exposed to Zn for 17 months, indicating that significant adaptation of the community to Zn had occurred. Similarly, this protocol was able to demonstrate adaptation of soil biological nitrification to Pb, with EC50 values of 1960 and 3150 mg/kg for the unexposed and exposed treatments, respectively. Exposure of unadapted and adapted microbial communities to a combination of Zn and Cd showed that the presence of Cd did not lead to greater toxicity in either community. Adapted communities were not more sensitive to decreases in soil pH than unadapted communities. Prior exposure to Zn was found to confer significantly greater tolerance of the community to Pb. Prior exposure to Pb similarly conferred significantly greater tolerance of the community to Zn. Implications of the adaptive capacity of soil microbes to the development of critical threshold values for heavy metals in soil based on ecotoxicity assessments are discussed.

Determining toxicity of lead and zinc runoff in soils: salinity effects on metal partitioning and on phytotoxicity

When assessing cationic metal toxicity in soils, metals are often added to soil as the chloride, nitrate, or sulfate salts. In many studies, the effects of these anions are ignored or discounted; rarely are appropriate controls included. This study used five soils varying in pH, clay content, and organic matter to determine whether salinity from counter-ions contributed to or confounded metal phytotoxicity. Varying rates of Pb and Zn were applied to soils with or without a leaching treatment to remove the metal counter-ion (NO3-). Lactuca sativa (lettuce) plants were grown in metal-treated soils, and plant dry weights were used to determine median effective concentrations where there was a 50% reduction in yield (EC50s) on the basis of total metals measured in the soil after harvest. In two of the five soils, leaching increased the EC50s significantly for Zn by 1.4- to 3.7-fold. In three of the five soils, leaching increased the EC50s significantly for Pb by 1.6- to 3.0-fold. The shift in EC50s was not a direct result of toxicity of the nitrate ion but was an indirect effect of the salinity increasing metal concentrations in soil solution and increasing its bioavailability for a given total metal concentration. In addition, calculation of potential salinity changes in toxicological studies from the addition of metals exhibiting strong sorption to soil suggested that if the anion associated with the metal is not leached from the soil, direct salinity responses could also lead to significant overestimation of the EC50 for those metals. These findings question the relevance of the application of single-metal salts to soils as a method of assessing metal phytotoxicity when, in many cases in our environment, Zn and Pb accumulate in soil over a period of time and the associated counter-ions are commonly removed from the soil during the accumulation process (e.g.. roof and galvanized tower runoff).

Results of a nationwide Veterans Affairs initiative to align graduate medical education and patient care

CONTEXT

Planning for the US physician workforce is imprecise. Prevailing policy generally advocates more training in primary care specialties.

OBJECTIVE

To describe a program to increase primary care graduate medical education (GME) in a large academic health system-the Veterans Health Administration of the Department of Veterans Affairs (VA).

DESIGN

In 1995, a VA advisory panel recommended a 3-year plan to eliminate 1000 specialist training positions and add 750 primary care positions. After assessing the impact of the first year of these changes on patient care, the VA implemented modifications aimed at introducing primary care curricula for training of internal medicine subspecialists, neurologists, and psychiatrists. The change in strategy was in response to the call for better alignment of GME with local patient care and training needs to provide coordinated, continuous care for seriously and chronically ill patients.

SETTING

The VA health system, including 172 hospitals, 773 ambulatory and community-based clinics, 206 counseling centers, and 132 nursing homes.

PARTICIPANTS

A total of 8900 VA residency training positions affiliated with 107 medical schools.

MAIN OUTCOME MEASURE

Proportion of residents in primary care training during the 3-year alignment.

RESULTS

Over 3 years, primary care training in the VA increased from 38% to 48% of funded positions. Of this total, 39% of the increase was in internal medicine subspecialties, neurology, and psychiatry.

CONCLUSION

In this case study of GME realignment, national policy was driven more by local patient care issues than by a perceived national need for primary care or specialty positions.

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.

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.

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.

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.

Medical student education in managed care settings: beyond HMOs

OBJECTIVE

To describe the educational experiences of students in managed care settings and to compare these with recommendations for preparing physicians to practice in managed care.

DESIGN

We searched MEDLINE using the keywords "medical education," "managed care," "health maintenance organization," and others; we manually checked the reference lists of identified articles and reports from 1969 to 1996. Survey information was obtained from all US medical schools in 1995 and 1996. Site visits were made to 6 managed care organizations selected according to size, geographic region, and involvement in education.

MAIN OUTCOME MEASURES

The extent to which schools use managed care settings for clinical education, the types of settings used, and the kinds of educational programs experienced.

RESULTS

In 1995 and 1996, an average of 16% of schools required all students to have clerkships or other clinical experiences in a group/staff model HMO, and some students from another 46% of schools spent time in an HMO for clerkships or physical diagnosis/introduction to clinical medicine courses. About 85% of schools potentially exposed students to other types of managed care during 1 or more required clinical experiences in ambulatory, community-based settings. The learning objectives of these experiences did not explicitly address features unique to managed care such as cost containment and disease prevention.

CONCLUSION

The selection of managed care settings for undergraduate education is based on general clinical objectives rather than explicit goals tied to managed care. Whether these experiences in managed care settings help students to develop competencies for future practice in a managed care environment has not been demonstrated. While the feasibility of medical education in nonprofit group/staff model HMOs is well documented, it is not certain whether these models can be adapted to for-profit managed care settings.

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.

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.

Generation and purification of recombinant fimbrillin from Porphyromonas (Bacteroides) gingivalis 381

Fimbrillin is the major subunit protein of fimbriae from the human periodontal pathogen Porphyromonas (Bacteroides) gingivalis. We describe here the generation and initial characterization of recombinant fimbrillin (r-fimbrillin) isolated from P. gingivalis 381. A fragment of DNA encoding the gene for fimbrillin was generated by polymerase chain reaction and cloned into the expression vector pET11b. Plasmids containing the recombinant gene were transfected into Escherichia coli. Clones were selected on plates for ampicillin resistance and individually screened by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) for protein production after activation with IPTG (isopropyl-beta-D- thiogalactopyranoside). One clone, OW0.2, produced significant amounts of a 42-kDa protein after induction with IPTG. This clone contained the pET11b plasmid with a 1-kb insert that had sequence homology to the gene encoding fimbrillin. The majority of recombinant protein from clone OW0.2 was found in the cytoplasm within inclusion bodies. Protein aggregates were solubilized in 8 M urea, and SDS-PAGE analysis showed two major protein bands, one at 42 kDa and the other at 17 kDa. These two proteins coeluted from a DEAE-Sepharose column at 0.15 M NaCl and were reactive to rabbit antiserum to fimbrillin in a Western blot (immunoblot). A preparation giving a single protein band at 42 kDa in SDS-PAGE was obtained by size fractionation by using continuous-elution electrophoresis. Lymph node cells from animals immunized with either fimbrillin from P. gingivalis or r-fimbrillin showed antigen-specific proliferation to both P. gingivalis fimbrillin and r-fimbrillin in an in vitro recall assay. Therefore, it appears that r-fimbrillin is chemically, antigenically, and serologically identical to fimbrillin isolated from P. gingivalis 381.

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.

Elastase is a constituent product of T cells

Proteases produced by immune cells have been found to be important components of the immune response to antigen. A protease previously unrecognized as a specific T cell product has been identified which has the gene sequence, serologic crossreactivity, and enzymatic specificity of elastase. T cell elastase, found in combination with the natural elastase inhibitor alpha 1-antitrypsin (alpha 1-protease inhibitor, alpha 1-PI), is produced by both CD4+ and CD8+ T lymphocytes, and is found both in a membrane-bound and in a soluble form in murine T cell lines.

Regulation of oxygen concentration delivered to infants via nasal cannulas

The administration of oxygen to infants via nasal cannulas is now a common practice in neonatal units although the inspired oxygen concentration reaching the patient's airway is unknown. We measured the hypopharyngeal oxygen concentration in 10 infants who were receiving oxygen via nasal cannulas and assessed the impact of changes in the flow rate and inspired oxygen concentration. Weaning these infants by reducing the flow rate, even if changes are slight, produces clinically important changes in the oxygen concentration reaching the airway. Such changes are poorly tolerated by infants with chronic lung disease. Changing the flow rate and inspired oxygen concentration, rather than the flow rate alone, provides greater precision and is likely to avoid excessive and abrupt changes in the oxygen concentration reaching the airway.

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.

Selective primary health care: strategies for control of disease in the developing world. XIX. Giardiasis

Giardia lamblia infects millions of individuals throughout the world. In developed countries it appears primarily in waterborne epidemics of diarrhea. In developing countries, it is endemic, but only a small proportion of those infected appear ill. This flagellate parasite infects the small intestine of its host and may cause malabsorption and malnutrition, particularly among infants and young children. Little is known about the extent of illness caused by this parasite because few epidemiologic studies have been done; diagnosis is difficult and Giardia carriers frequently are simultaneously infected with other pathogens. Control measures include intermittent treatment of those infected and improved water supply and sanitation. Efforts to control individual infection can only be successful on a temporary basis. The greatest progress in control should derive from efforts to develop an effective vaccine.

Giardiasis: host-pathogen biology

Giardiasis is the most common waterborne diarrheal disease in the United States and is highly prevalent throughout the world. The clinical spectrum of disease ranges from asymptomatic infection to persistent severe malabsorption. The precise interaction between Giardia and its human host remains conjectural because of the paucity of published studies that address the details of its pathogenesis. The immune system of the host responds to this protozoan parasite, and the intestinal epithelium is a site of interaction between parasite and host. Possible mechanisms whereby Giardia may alter the host's absorption of nutrients at the epithelial level include direct physical interference, toxin secretion, direct physical alteration of the epithelium, competition for nutrients, induction of an inflammatory response, and coincidental infection of the host with a second organism. The host's immune system may play both a protective and a pathogenic role.

Phagocytosis of Giardia muris by macrophages in Peyer's patch epithelium in mice

No mechanism for the initiation of immunological clearance of Giardia from the mammalian intestinal tract has been identified. In normal and nude mice experimentally infected with G. muris, we examined antigen-sampling epithelium over Peyer's patch follicles by electron microscopy for evidence of interaction between G. muris and lymphoid cells. Invading G. muris were found in the epithelium near dying or desquamating columnar cells. Macrophages beneath the basal lamina extended pseudopods into the epithelium, trapping invading G. muris and enclosing them in phagolysosomes. In normal mice, which clear G. muris in 4 to 6 weeks, macrophages containing digested G. muris were surrounded by rosettes of lymphoblasts in the epithelium. In nude mice deficient in lymphocytes, there was apparent hyperplasia of macrophages, which filled the follicle domes, resulting in more frequent entrapment of G. muris but no contact between macrophages and lymphoblasts in the epithelium. In nude mice, which require 6 months to control G. muris infection, lymphoblast contact with macrophages containing distinctive microtubular remnants of G. muris was only identified in the follicle dome. This close physical association of lymphoblasts and macrophages containing G. muris remnants suggests that this macrophage activity represents intraepithelial antigen processing as well as a defense against the effects of the uncontrolled entrance of microorganisms and other antigenic particles into Peyer's patch lymphoid follicles.

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.

Ultrastructural observations on giardiasis in a mouse model. II. Endosymbiosis and organelle distribution in Giardia muris and Giardia lamblia

Ultrastructural observations of Giardia muris in a mouse model revealed endosymbiotic microbes not previously reported in Giardia. Endosymbionts 240--360 nm wide, 600--1,400 nm long, and with an internal structure similar to that of bacilli were not seen entering Giardia but were found and appeared to divide within Giardia. No evidence was found of digestion of the endosymbionts by the giardia host in either the trophozoite or the cyst form. Endosymbionts were concentrated centrally around the nuclear area and were uncommon in peripheral feeding regions. The same cellular organelles seen in G. muris were found in Giardia lamblia from human jejunal biopsy material, but no endosymbionts were identified in G. lamblia trophozoites from the seven patients examined. Endosymbionts within Giardia may be found to alter trophozoite pathogenicity, metabolism, range of infectivity, antigenic surface characteristics, and host specificity, as they do in other protozoa.

Ultrastructural observations on giardiasis in a murine model. I. Intestinal distribution, attachment, and relationship to the immune system of Giardia muris

Infected immunocompetent mice were studied prospectively in a well-described murine model system with the use of ultrastructural techniques to establish normal distribution of Giardia muris trophozoites, their relationships to intestinal mucosa, particularly Peyer's patches, and structural indications of the normal reaction of intestine and intestinal immune organs. Trophozoites colonized the proximal 25% of the intestine, adhered to microvilli of columnar cells near the bases of villi, wedged into furrows in the epithelial surface, or lodged in mucus within the unstirred layer. Density of trophozoite colonization of the jejunal epithelium correlated with stool cyst excretion. Over Peyer's patches, Giardia adhered to columnar cells and not to M-cells, which transport soluble antigens and particulate material from the lumen into the lymphoid system. Giardia entered intestinal lymphoid structures by incursions through defects in the lymphoid follicle epithelial barrier. During clearance of parasites, lymphocytes crossed the epithelium and attached to Giardia in the lumen. Giardia produced no apparent ultrastructural damage in normal mice but elicited a previously undescribed intraluminal cellular immune response during clearance by the host.

Animal model of human disease: giardiasis

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Factors influencing small bowel changes in dermatitis herpetiformis

Factors influencing small bowel morphology in dermatitis herpetiformis (DH) were investigated by comparing patients with DH and normal small bowel biopsies to patients with DH and abnormal small bowel biopsies. The mean age of 18 patients with morphological changes in small bowel (38 years) was significantly lower (P less than 0-001) than the mean age of nine patients with normal bowel mucosa (60 years). HLA typing confirmed the high frequency of HLA-B8 in DH (64%) but HLA-B8 was unrelated to the presence or severity of small bowel lesions. Four patients had diarrhoea with progressive weight loss or abdominal cramps subsequently responsive to gluten withdrawal. In this subgroup serum levels of IgG and IgM were significantly lower than in patients with normal small bowel mucosa. Small bowel involvement appeared to be independent of the duration and severity of skin disease, and the deposition of immunoglobulin and complement (C3) in the dermal papillae of skin adjacent to skin lesions.

What happens when hospitalized patients see their own records

The effect of giving hospitalized medical patients access to their problem-oriented hospital records was investigated. Twenty-five subjects were given free access to their records while 25 other subjects served as controls. Few of the open record group actively sought and studied their records; most elected to see them only as part of routine ward rounds; and one objected to seeing the record at all. Taking the experimental group as a whole, there was no measurable effect of seeing the record on the subjects' ability to list their diagnoses or medications, their self-assessment of depression, anxiety or contentment, or their attitudes toward selected components of the health care system. On the other hand, in individual instances access to the hospital record seemed to facilitate communication and provide an opportunity for hospital inpatients to monitor objectively their hospital course.

Suppression of giardiasis during the intestinal phase of trichinosis in the mouse

The interaction of the intestinal phases of Giardia muris and Trichinella spiralis was investigated in Swiss albino mice. Intraoesophageal inoculation of G. muris cysts seven days before, or seven days after, similar inoculation of T. spiralis larvae resulted in significant reduction in the numbers of Giardia trophozoites in small bowel and Giardia cysts in stools. This effect was not observed when G. muris cysts were administered after resolution of the intestinal phase of trichinosis. Giardiasis had no effect on trichinosis as assessed by numbers of adult worms in small bowel and larvae in skeletal muscles. Studies of small bowel morphology showed that the intestinal phase of trichinosis was associated with increased numbers of inflammatory cells in the lamina propria, a significant increase in Paneth cells in crypts, and a marked reduction in the villus:crypt ratio of jejunum. These observations suggest that the intestinal phase of trichinosis induced environmental changes in small bowel, perhaps related to inflammation, which resulted in suppression of proliferation of Giardia trophozoites.