Advocating for Policy Change: Examples Emerging From a Medical-Legal Partnership in Primary Care

Medical-legal partnerships bring legal services directly into clinical settings. Policy advocacy is often opportunistic and varies across partnerships. Our objective was to study policy advocacy that emerged from a medical-legal partnership in Toronto over a four-year period. This study consisted of a document review and thematic analysis, triangulated with data from interviews with legal team members and health providers. We defined policy advocacy as actions associated with attempts to change policy or legislation. The medical-legal partnership engaged in seven distinct cases of policy advocacy: disability support form requirements, changing workplace review, challenging barriers to citizenship, housing, publicly funded medication program (pharma care), safe injection sites, and the need for increased social assistance. Actions taken included presentations at conferences and submissions of briefs to government. We found that a medical-legal partnership resulted in policy advocacy with issues arising from both the health and the legal team with impacts likely greater than if each group had acted alone.

A rapid realist review of clinical neuropsychology rehabilitation programmes to improve psychological wellbeing and quality of life for people with acquired brain injuries

Approximately 20% of acquired brain injury (ABI) survivors experience reduced psychological wellbeing (PWB). Neuropsychological rehabilitation (NPR) is one approach supporting people with ABI to participate meaningfully in activities despite challenges. Although literature supports NPR effectiveness, little is known about change mechanisms. This systematic realist review identifies what NPR programmes have been designed, delivered, and evaluated for people with ABI to improve PWB and/or quality of life (QOL), as well as providing a context-relevant understanding of what NPR includes and how NPR might lead to positive outcomes. A rapid realist review was conducted in three phases: (1) structured retrieval and evidence extraction; (2) stakeholder consultation; (3) analysis and synthesis. Searches were completed, and findings from 35 publications and one stakeholder consultation were synthesized into a refined logic model. Six context-mechanism-outcome chains (CMOCs) were identified. Participants' relationships to internal experiences, and feelings of self-worth, mastery, and connection appeared to be mechanisms that led to improved PWB and QOL. Adaptation and individualized programmes were also key mechanisms to explain successful NPR. Embedding CMOCs into NPR could improve PWB and/or QOL for people with ABI. The logic model will inform ongoing development of a new online, group-based, NPR programme.

Sucrase Breath Testing in Children Presenting With Chronic Abdominal Pain

Sucrase deficiency has been implicated in chronic abdominal pain. Testing for sucrase deficiency generally involves invasive procedures or lengthy clinical visits, but now noninvasive kits that allow home testing are available to test for sucrase deficiency. In order to assess feasibility and utility of at-home testing, we reviewed our experience in 75 consecutive patients. All patients seen in the abdominal pain clinic had histories obtained in a standardized fashion and all had sucrase breath tests completed at home utilizing a commercially available kit. Testing was completed by 46 patients (61.3%). Tests were abnormal indicating sucrase deficiency in 34.8% of those completing testing. No symptoms were predictive of a positive test although there were trends of an association of an abnormal test with diarrhea and bloating. Our findings suggest that sucrase deficiency occurs frequently enough that more widespread testing and/or an empiric trial of sucrose and starch restriction should be considered.

Intergenerational care: an exploration of consumer preferences and willingness to pay for care

OBJECTIVES

To identify feasible models of intergenerational care programmes, that is, care of children and older people in a shared setting, to determine consumer preferences and willingness to pay.

METHOD

Feasible models were constructed in extensive consultations with a panel of experts using a Delphi technique (n = 23) and were considered based on their practical implementation within an Australian setting. This informed a survey tool that captured the preferences and willingness to pay for these models by potential consumers, when compared to the status quo. Information collected from the surveys (n = 816) was analysed using regression analysis to identify fundamental drivers of preferences and the prices consumers were willing to pay for intergenerational care programmes.

RESULTS

The shared campus and visiting models were identified as feasible intergenerational care models. Key attributes of these models included respite day care; a common educational pedagogy across generations; screening; monitoring; and evaluation of participant outcomes. Although parents were more likely to take up intergenerational care compared to the status quo, adult carers reported a higher willingness to pay for these services. Educational attainment also influenced the likely uptake of intergenerational care.

CONCLUSIONS

The results of this study show that there is demand for the shared campus and the visiting campus models among the Australian community. The findings support moves towards consumer-centric models of care, in line with national and international best practice. This consumer-centric approach is encapsulated in the intergenerational care model and enables greater choice of care to match different consumer demands.

The application of triple aim framework in the context of primary healthcare: A systematic literature review

The Triple Aim framework is an increasingly popular tool for designing and assessing quality improvements in the health care sector. We systematically reviewed the empirical evidence on the application of the Triple Aim framework within primary healthcare settings since its inception almost a decade ago. Results show that primary healthcare providers varied in their interpretation of the Triple Aim framework and generally struggled with a lack of guidance and an absence of composite sets of measures for performance assessment. Greater clarity around application of the Triple Aim framework in primary healthcare is needed, especially around the selection and implementation of purposeful measures from locally available data. This review highlights areas for improvement and makes recommendations intended to guide future applications of the Triple Aim in the context of primary healthcare.

Role of local eosinophilopoietic processes in the development of airway eosinophilia in prednisone-dependent severe asthma

BACKGROUND

In severe asthmatics with persistent airway eosinophilia, blockade of interleukin-5 has significant steroid-sparing effects and attenuates blood and sputum eosinophilia. The contribution of local maturational processes of progenitors within the airways relative to the recruitment of mature cells from the peripheral circulation to the development of airway eosinophilia is not known. We hypothesize that local eosinophilopoiesis may be the predominant process that drives persistent airway eosinophilia and corticosteroid requirement in severe asthmatics.

OBJECTIVES

In a cross-sectional study, the number and growth potential of eosinophil-lineage-committed progenitors (EoP) were assayed in 21 severe eosinophilic asthmatics, 19 mild asthmatics, eight COPD patients and eight normal subjects. The effect of anti-IL-5 treatment on mature eosinophils and EoP numbers was made in severe eosinophilic asthmatics who participated in a randomized clinical trial of mepolizumab (substudy of a larger GSK sponsored global phase III trial, MEA115575) where subjects received mepolizumab (100 mg, n = 9) or placebo (n = 8), as six monthly subcutaneous injections.

RESULTS

Mature eosinophil and EoP numbers were significantly greater in the sputum of severe asthmatics compared with all other subject groups. In colony-forming assays, EoP from blood of severe asthmatics demonstrated a greater response to IL-5 than mild asthmatics. Treatment of severe asthmatics with mepolizumab significantly attenuated blood eosinophils and increased EoP numbers consistent with blockade of systemic eosinophilopoiesis. There was however no significant treatment effect on mature eosinophils, sputum EoP numbers or the prednisone maintenance dose.

CONCLUSIONS AND CLINICAL RELEVANCE

Patients with severe eosinophilic asthma have an exaggerated eosinophilopoeitic process in their airways. Treatment with 100 mg subcutaneous mepolizumab significantly attenuated systemic differentiation of eosinophils, but did not suppress local airway eosinophil differentiation to mature cells. Targeting IL-5-driven eosinophil differentiation locally within the lung maybe of relevance for optimal control of airway eosinophilia and asthma.

Histone deacetylase activity and recurrent bacterial bronchitis in severe eosinophilic asthma

An increase in P13 Kinase activity and an associated reduction in histone deacetylase activity may contribute to both relative steroid insensitivity in patients with severe eosinophilic asthma and impaired macrophage scavenger function and susceptibility to recurrent infective bronchitis that may, in turn, contribute to further steroid insensitivity.

The effects of an epithelial barrier protective cationic aerosol on allergen-induced airway inflammation in asthma: a randomized, placebo-controlled clinical trial

Inhaled cationic airway lining modulator (iCALM) is a cationic aerosol therapy comprised of 1.29% calcium chloride dissolved in 0.9% isotonic saline that enhances the biophysical barrier function of the airway lining fluid and primes the host defense response. It's ability to attenuate bronchitis caused by inhaled particles was investigated using an allergen-inhalation model in a proof-of-concept study. In a randomized, double-blind, placebo-controlled cross-over trial of 6 mild atopic steroid-naïve asthmatic subjects, 3 doses of iCALM were well tolerated and they attenuated allergen-induced increase in sputum eosinophils, and levels of IL-5, MCP-1 and eotaxin. This study provides an opportunity to investigate the role of enhancing epithelial barrier to decrease airway inflammation provoked by inhaled particles in a variety of airway diseases.

Eosinophil peroxidase in sputum represents a unique biomarker of airway eosinophilia

BACKGROUND

Sputum eosinophilia has been shown to be a predictor of response to anti-eosinophil therapies in patients with airway diseases. However, quantitative cell counts and differentials of sputum are labor intensive. The objective of this study was to validate a novel ELISA-based assay of eosinophil peroxidase (EPX) in sputum as a rapid and reliable marker of airway eosinophils.

METHODS

The utility of EPX-based ELISA as an eosinophil-specific assay was achieved through comparisons with sputum eosinophil differential counts in freshly prepared and archived patient samples from a variety of clinical settings.

RESULTS

EPX levels in sputum correlated with eosinophil percentage (r(s) = 0.84) in asthma patients with varying degrees of airway eosinophilia. Significantly, unlike assays of other eosinophil granule proteins (e.g., ECP and EDN), which often detect the presence of these proteins even in asthma patients with neutrophilic bronchitis, EPX-based ELISA levels are not increased in this subset of asthma patients or in COPD patients lacking evidence of an airway eosinophilia. Moreover, sputum EPX was a surrogate marker of airway eosinophilia in other patient studies (e.g., allergen inhalation and treatment trials the anti-(IL-5) therapeutic Mepolizumab™). Finally, EPX levels in cytocentrifuged prepared sputum supernatants correlated with those from rapidly prepared noncentrifuged filtrates of sputum (r(s) = 0.94).

CONCLUSION AND CLINICAL IMPLICATION

EPX-based ELISA is a valid, reliable, repeatable, and specific surrogate marker of eosinophils and/or eosinophil degranulation in the sputum of respiratory patients. The novel EPX assay is a valid and reproducible eosinophil-specific assay that can potentially be developed into a point-of-care assessment of eosinophil activity in airway secretions.

The impact of maternal depression during pregnancy on perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

Depression often remains undertreated during pregnancy and there is growing evidence that untoward perinatal outcomes can result. Our systematic review and meta-analysis was conducted to determine whether maternal depression during pregnancy is associated with adverse perinatal and infant outcomes.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, and PsycINFO were searched from their start dates to June 2010. Keywords utilized included depressive/mood disorder, postpartum/postnatal, pregnancy/pregnancy trimesters, prenatal or antenatal, infant/neonatal outcomes, premature delivery, gestational age, birth weight, NICU, preeclampsia, breastfeeding, and Apgar.

STUDY SELECTION

English language studies reporting on perinatal or child outcomes associated with maternal depression were included, 3,074 abstracts were reviewed, 735 articles retrieved, and 30 studies included.

DATA EXTRACTION

Two independent reviewers extracted data and assessed article quality. All studies were included in the primary analyses, and between-group differences for subanalyses are also reported.

RESULTS

Thirty studies were eligible for inclusion. Premature delivery and decrease in breastfeeding initiation were significantly associated with maternal depression (odds ratio [OR] = 1.37; 95% CI, 1.04 to 1.81; P = .024; and OR = 0.68; 95% CI, 0.61 to 0.76; P < .0001, respectively). While birth weight (mean difference = -19.53 g; 95% CI, -64.27 to 25.20; P = .392), low birth weight (OR = 1.21; 95% CI, 0.91 to 1.60; P = .195), neonatal intensive care unit admissions (OR = 1.43; 95% CI, 0.83 to 2.47; P = .195), and preeclampsia (OR = 1.35; 95% CI, 0.95 to 1.92; P = .089) did not show significant associations in the main analyses, some subanalyses were significant. Gestational age (mean difference = -0.19 weeks; 95% CI, -0.53 to 0.14; P = .262) and Apgar scores at 1 (mean difference = -0.05; 95% CI, -0.28 to 0.17; P = .638) and 5 minutes (mean difference = 0.01; 95% CI, -0.08 to 0.11; P = .782) did not demonstrate any significant associations with depression. For premature delivery, a convenience sample study design was associated with higher ORs (OR = 2.43; 95% CI, 1.47 to 4.01; P = .001).

CONCLUSIONS

Maternal depression during pregnancy is associated with increased odds for premature delivery and decreased breastfeeding initiation; however, the effects are modest. More research of higher methodological quality is needed.

Mast cell activation and clinical outcome in pediatric cholelithiasis and biliary dyskinesia

Background

The current study was undertaken to determine the degree of activation of gallbladder mucosal mast cells, whether mast cell (MC) density or activation differ between patients with and without a positive clinical response to cholecystectomy, and whether either density or activation correlate with gallbladder emptying.

Results

Fifteen biliary dyskinesia (BD) and 13 symptomatic cholelithiasis (CL) patients undergoing cholecystectomy were prospectively enrolled. Gallbladder wall MC density (by immunohistochemistry) and activation (by electron microscopy) were determined. Clinical response was evaluated 30 days post-cholecystectomy on a 5-point Likert-type scale. A complete or nearly complete clinical response was seen in 100% of CL and in 87% of BD patients. The overall degranulation indices were 49.4 ± 18.7% for CL patients and 44.2 ± 16.8% for BD patients. Neither MC density nor activation correlated with the gallbladder ejection fraction. A complete clinical response was associated with lower epithelial MC density.

Conclusion

Cholecystectomy is efficacious in relieving pain in both CL and BD patients. BD and CL are associated not only with increased MC density but a moderate to high degree of MC activation. A possible relationship between MC density and outcome for BD warrants further investigation.

Human airway smooth muscle promotes eosinophil differentiation

INTRODUCTION

Human airway smooth muscle (HASM) cells in culture synthesize cytokines and chemokines that may orchestrate the tissue homing and in situ differentiation of haemopoietic progenitor cells from the peripheral circulation.

OBJECTIVE

To study the effect of a supernatant from cultured HASM cells on the differentiative and transmigrational responses of haemopoietic progenitor cells.

METHODS

HASM cells were grown to confluence and stimulated with a cytomix of TNF-alpha, IL-1beta and IFN-gamma. Peripheral blood-derived progenitors from atopic asthmatics (n=12) and non-atopic controls (n=11) were grown in a methylcellulose culture with a supernatant from stimulated HASM cells to assess clonogenic potential. The ability of HASM cells to stimulate directional migration and adhesion to fibronectin of blood progenitors was also investigated.

RESULTS

HASM cells stimulated significant growth of eosinophil/basophil colony forming units (Eo/B CFUs) from blood progenitor cells from both groups of subjects. This activity was significantly attenuated in the presence of anti-IL-5 and anti-granulocyte macrophage-colony forming factor blocking antibodies and by pre-treatment with SB202190 [p38 mitogen-activated protein kinase (MAPK) inhibitor]. An src kinase (srcK) inhibitor (Pyrazolopyrimidine 1) was less effective at attenuating IL-5- and HASM-stimulated Eo/B CFU growth from both groups of subjects. Examination of the phosphorylation of these kinases in CD34(+) cells following co-incubation with the major constituents of HASM showed activation of p38 MAPK but not that of the srcK pathway. The HASM supernatant had no significant effect on the migrational and adhesive responses of haemopoietic progenitor cells in vitro.

CONCLUSION

We have shown that HASM cell-derived cytokines promote eosinophil differentiation that is dependent on p38 MAPK but not on the srcK pathway. This study shows that a major structural cell of the lungs, airway smooth muscle, has the capability to direct eosinophil differentiation and maturation from progenitor cells, which in turn may perpetuate an eosinophilic inflammation and consequently tissue remodelling in patients with chronic asthma.

Lung transplantation for cystic fibrosis: Current concepts and one center's experience

BACKGROUND

Although new approaches to the treatment of patients with cystic fibrosis (CF) are significantly prolonging their lives, most patients will eventually develop respiratory failure due to progressive bronchiectasis caused by chronic lung infection and inflammation and die from to respiratory failure. We examined our center's (University of Wisconsin Hospital and Clinics) experience with lung transplantation for patients with CF and reviewed the literature to examine current and evolving approaches to transplantation for this indication.

METHODS

We reviewed all published literature pertaining to lung transplantation for CF through 2006, and we reviewed all aspects of transplantation for patients with CF at our institution from 1994 to 2005.

RESULTS

Major complications following lung transplantation include acute rejection, bacterial infection, and bronchiolitis obliterans. Five-year survival at UWHC (Kaplan-Meier) is 67%, and survival was not adversely affected by transplanting patients receiving mechanical ventilation. The major cause of death for transplant recipients was bronchiolitis obliterans syndrome (BOS).

CONCLUSIONS

Lung transplantation for CF is associated with acceptable survival rates and can improve quality of life. Lung transplant should be offered to all patients with advanced CF lung disease if they meet currently accepted inclusion and exclusion criteria.

Person-centred dementia services are feasible, but can they be sustained?

BACKGROUND

we evaluated a specialist community-based dementia service to establish whether high quality care was being delivered and the conditions for doing so. The service was in an urban part of Rushcliffe Primary Care Trust, Nottinghamshire, United Kingdom. The service comprised an assessment team of an occupational therapist, a community psychiatric nurse and a community care officer, supported by 235 h per week of care delivered by a team of specially trained community care workers.

METHODS

a qualitative study was performed using non-participant observation, semi-structured interviews and focus groups, and analysed using a thematic framework approach. There were 2 focus groups involving staff, 11 interviews of staff and stakeholders, and interviews of 15 carers of people with dementia.

RESULTS

the care provided was appreciated by carers, and the service was approved by staff and stakeholders. Care was delivered using a rehabilitative style that aimed to maintain personhood, rather than to promote independence. Clients were usually referred with the object of preventing unwanted admission to institutional care but, over time, moving into an institution ceased to be a uniformly undesirable outcome. The service's resources were reduced during the evaluation period, in part to meet mental health needs in intermediate care services.

CONCLUSIONS

an appropriately resourced and constructed specialist service using an adaptive rehabilitation approach aimed at maintaining personhood can deliver good individualised care to people with dementia, but specific and appropriate commissioning for these services is needed to nurture them.

Extracellular matrix regulates human airway smooth muscle cell migration

Extracellular matrix proteins regulate the survival and proliferation of smooth muscle cells. Their effect on airway smooth muscle cell migration is not known. Their role in leukotriene-primed (0.1 microM leukotriene E4) chemotaxis of cultured human airway smooth muscle cells towards platelet-derived growth factor BB (1 ng.mL(-1)) was investigated. Migration of cells was greater on membranes coated with collagens III and V and fibronectin compared to collagen I, elastin and laminin (all 10 microg.mL(-1)). Concentration-dependent promotion of migration was observed on collagen I (1,000>10 microg.mL(-1)), which was associated with increased phosphorylation of Src kinase. This was not observed on laminin or elastin. The role of Src kinase was further confirmed by demonstrating that its inhibitor, PP1 analogue (1 microM), inhibited chemotaxis. Collagen I itself was not a chemoattractant; however, haptokinesis was observed when cells were primed with leukotriene E4, and haptotaxis when cells were primed with platelet-derived growth factor. The priming effect of leukotrienes on chemotaxis was not elicited by promoting adhesion, increasing surface expression of beta1, alphav and alpha5 integrin, or Src kinase phosphorylation. These experiments demonstrate that the extracellular matrix, along with growth factors and cysteinyl leukotrienes, can regulate human airway smooth muscle cell migration. This may be relevant in the remodelling process in chronic airway diseases, such as asthma.

A UK multi-centre pilot study of speech and swallowing outcomes following head and neck cancer

Speech and swallowing are important components of health-related quality of life following head and neck cancer treatment. The aim of this study was to demonstrate the value of prospective multi-centre evaluation by Speech and Language Therapists and to compare health-related quality of life with speech and swallowing impairments. The University of Washington Head and Neck questionnaire version 4 (UW-QOL) and Therapy Outcome Measures (TOM) were rated before and 6 months after cancer treatment in 95 patients from 12 centres. There was deterioration in TOM scores at 6 months. Pretreatment UW-QOL swallowing was ranked equal first, with speech fourth. At 6 months speech was first and swallowing second. There were positive correlations between UW-QOL swallowing and TOM dysphagia and between UW-QOL speech and TOM laryngectomy, voice, phonology and dysarthria disorders. Both outcome measures are suitable for routine practice. Adaptation of TOM scales for use with head and neck cancer patients may improve sensitivity, validity and therapist compliance.

Surgical voice restoration following ablative surgery for laryngeal and hypopharyngeal carcinoma

Surgical voice restoration is an important part of functional rehabilitation of patients following ablative surgery for laryngeal and hypopharyngeal carcinoma. The aim of this retrospective study was to assess the functional status with regard to speech of a cohort of 100 patients (age ranged 34-84 years), who underwent laryngectomy and laryngopharyngectomy over a 10-year period (1989-1999). Ninety-two patients consented to surgical voice restoration. Primary tracheoesophageal punctures were performed in 70 and secondary punctures in 22 (mainly after jejunal flap reconstruction). Nine patients were excluded from this analysis (seven patients died prior to assessment, one had the prosthesis removed at her request and one patient had insufficient follow-up). Tracheoesophageal speech was assessed in the remaining 83 patients using a rating scale measuring the number of syllables per breath, use of voice and intelligibility by non-professional listeners. Currently, Provox 2 valves are being used in the majority of patients. Overall tracheoesophageal speech results were good in 45/83 (54.2 per cent), average in 22/83 (26.5 per cent) and poor in 15/83 (18 per cent). One patient could not develop tracheoesophageal speech. The majority of laryngectomy patients had good speech but in patients who had complex reconstructions tracheoesophageal speech was mostly rated as average. Average to good speech in more than two-thirds of the cohort of patients show that surgical voice restoration is a highly successful and valuable technique to restore speech functions after ablative surgery for laryngeal and hypopharyngeal carcinoma.

Immunogenicity of CD63 in a patient with melanoma

CD63 is a member of the tetraspan family of molecules that is expressed in melanoma and which appears to be involved in regulation of motility and adhesion of melanoma cells. In the present study we have screened a cDNA library from a melanoma cell with antisera from a patient with melanoma and have shown that one of the antigens identified was CD63. The clone isolated contained a mutation in the transmembrane region, but this did not appear to be involved in immunogenicity of the molecule. Antisera from the patient showed weak reactivity with CD63 from melanoma and recombinant CD63 in Western blots. The latter studies showed marked variation in the fractions of CD63 identified with monoclonal antibodies to CD63 consistent with variable glycosylation of CD63. We suggest that glycosylation may account for its recognition by the human immune system. Further studies are required to assess the role of CD63 as an immunogen in melanoma.

Low-level visual processing of biological motion

Biological motion displays depict a moving human figure by means of just a few isolated points of light attached to the major joints of the body. Naive observers readily interpret the moving pattern of dots as representing a human figure, despite the complete absence of form cues. This paper reports a series of experiments which investigated the visual processes underlying the phenomenon. Results suggest that (i) the effect relies upon responses in low-level motion-detecting processes, which operate over short temporal and spatial intervals and respond to local modulations in image intensity; and (ii) the effect does not involve hierarchical visual analysis of motion components, nor does it require the presence of dots which move in rigid relation to each other. Instead, movements of the extremities are crucial. Data are inconsistent with current theoretical treatments.

Dysphonia as an atypical presentation of gastro-oesophageal reflux

We present three cases of dysphonia in which gastro-oesophageal reflux (GOR) appeared to be a precipitating factor. In all cases reflux was clinically occult. We discuss the theory and implications of GOR presenting atypically with laryngeal symptoms, and outline our current approach to laryngeal symptoms of clinically evident or occult GOR.

'The holiday plug': a temporary solution to the problem of the leaking voice prosthesis

Tracheo-oesophageal prostheses are commonly inserted in patients following total laryngectomy to improve the quality of the voice. Unfortunately the device eventually fails and requires replacement. A valve change, although well tolerated by patients, necessitates an out-patient visit and delay in its replacement can lead to problems of pneumonia or dehydration. In this short paper we describe a simple temporary solution for a leaking valve and recommend its use in patients who are delayed in returning to the unit for example when on holiday.

Weaning of three hybridoma cell lines to serum free low protein medium

A general weaning procedure is described which allowed a range of hybridomas to be weaned readily off serum without loss of antibody production. Initial work was carried out with one cell line only (SPO1 cells) and one serum substitute containing a final protein concentration of 40 mg l-1. The SPO1 cells were first adapted to a range of readily available basal media and then weaned off serum by a range of protocols. From this work an optimal weaning protocol and basal medium for weaning were determined. These were then used to wean the SPO1 cells and two other cell lines off serum with a second, protein free, serum substitute with varying concentrations of defined proteins added. All three cell lines investigated were readily weaned off serum by this protocol at protein concentrations as low as 1 mg l-1. No loss of antibody production was observed with any of the cell lines. The weaning procedure outlined in both simple and rapid and has been successfully adopted in our laboratory by relatively inexperienced cell culture technicians.