bluuebunny/crossref_metadata_2025 huggingface dataset:
Carthamus tinctorius Enhances the Antitumor Activity of Dendritic Cell Vaccines via Polarization toward Th1 Cytokines and Increase of Cytotoxic T Lymphocytes
Authors: Chang Jia-Ming , Hung Le-Mei , Chyan Yau-Jan , Cheng Chun-Ming , Wu Rey-Yuh
Published: November 2008

Carthamus tinctorius (CT), also named safflower, is a traditional Chinese medicine widely used to improve blood circulation. CT also has been studied for its antitumor activity in certain cancers. To investigate the effects of CT on the dendritic cell (DC)‐based vaccine in cancer treatment, cytokine secretion of mouse splenic T lymphocytes and the maturation of DCs in response to CT were analyzed. To assess the antitumor activity of CT extract on mouse CD117+ (c‐kit)‐derived DCs pulsed with JC mammal tumor antigens, the JC tumor was challenged by the CT‐treated DC vaccine in vivo. CT stimulated IFN‐γ and IL‐10 secretion of splenic T lymphocytes and enhanced the maturation of DCs by enhancing immunological molecule expression. When DC vaccine was pulsed with tumor antigens along with CT extract, the levels of TNF‐α and IL‐1β were dramatically increased with a dose‐dependent response and more immunologic and co‐stimulatory molecules were expressed on the DC surface. In addition, CT‐treated tumor lysate‐pulsed DC vaccine reduced the tumor weight in tumor‐bearing mice by 15.3% more than tumor lysate‐pulsed DC vaccine without CT treatment. CT polarized cytokine secretion toward the Th1 pathway and also increased the population of cytotoxic T lymphocytes ex vivo. In conclusion, CT activates DCs might promote the recognition of antigens and facilitate antigen presentation to Th1 immune responses.
Prolonged gene knockdown in the tsetse fly Glossina by feeding double stranded RNA
Authors: Walshe D. P. , Lehane S. M. , Lehane M. J. , Haines L. R.
Published: November 2008

Reverse genetic studies based on RNA interference (RNAi) have revolutionized analysis of gene function in most insects. However the necessity of injecting double stranded RNA (dsRNA) inevitably compromises many investigations particularly those on immunity. Additionally, injection of tsetse flies often causes significant mortality. We demonstrate, at transcript and protein level, that delivering dsRNA in the bloodmeal to Glossina morsitans morsitans is as effective as injection in knockdown of the immunoresponsive midgut‐expressed gene TsetseEP. However, feeding dsRNA fails to knockdown the fat body expressed transferrin gene, 2A192, previously shown to be silenced by dsRNA injection. Mortality rates of the dsRNA fed flies were significantly reduced compared to injected flies 14 days after treatment (Fed: 10.1%± 1.8%; injected: 37.9% ± 3.6% (Mean ± SEM)). This is the first demonstration in Diptera of gene knockdown by feeding and the first example of knockdown in a blood‐sucking insect by including dsRNA in the bloodmeal.
Chinese female nurses’ perceptions of male genitalia‐related care – Part 2
Authors: Zang Yu‐Li , Chung Loretta Y F , Wong Thomas K S , Chan Moon Fai
Published: November 2008

Aims.  This study was designed to investigate Chinese female nurses’ perceptions of certain male genitalia‐related care and the influence of their demography and experiences on their perceptions.

Background.  Several physical conditions, in which male genitalia‐related care is required, have been found to have considerable negative impact on male patients, leading to decreased quality of life and psychosocial and sexual dysfunctions. Available studies suggest that Chinese female nurses’ conduct during the provision of male genitalia‐related care is negative. However, the evidence is weak with respect of the degree of Chinese nurses’ negativity and what the contributory factors may be.

Design.  Survey.

Methods.  Chinese female nurses in nine units in five hospitals were surveyed. Of 378 returned questionnaires, 312 were usable, and 138 contained textual comments. Numerical data were analysed using spss14.0, and textual data were analysed using thematic analysis.

Results.  The majority of participants had never performed genital wound care, perineal area shaving, perineal hygiene, suprapubic and urinary catheterisation. More than half preferred only bladder irrigation and washout to be performed by nurses and preferred the other male genitalia‐related care to be performed by a male. Participants tended to agree meatal cleansing, perineal area shaving, perineal hygiene and urinary catheterisation were embarrassing, awkward and intrusive, but to disagree that they were sexual, dirty, stigmatising or having an impact on the male patient’s sexual health.

Conclusion.  This study suggests that Chinese female nurses play limited roles in the practice of male genitalia‐related care, but their perceptions of such care are not negative.

Relevance to clinical practice.  Given the increasing move of Chinese female nurses to other countries, sexuality, sexual harassment, privacy and the constraints of traditional Chinese beliefs on sexuality over professional nursing conduct should be emphasised in clinical training programmes.
‘Visible‐ness’: the nature of communication for children admitted to a specialist children's hospital in the Republic of Ireland
Authors: Lambert Veronica , Glacken Michele , McCarron Mary
Published: November 2008

Aim. This article presents the core concept of ‘visible‐ness’ that emerged from an ethnographic study, which explored the nature of communication, for children (for ease of reading children refers to children and young people), admitted to a children’s hospital in the Republic of Ireland.

Background. The importance of engaging with both child and family has been espoused as fundamental in promoting ‘family’‐centred care. To date, studies have almost exclusively explored parents’ and nurses’ perspectives of the nature of parent participation and nurse–parent interactions and relationships. Although there is evidence of an emerging body of knowledge, which explores children’s perspectives of their information, and communication needs, little is known empirically about the communication process between children and members of the health care team in inpatient hospital settings.

Design. The principles of ethnography underpinned the study design.

Method. Fieldwork took place over four months in one 35‐bedded children’s ward. Forty‐nine children, ranging in ages from 6 to 16 years with a variety of medical and surgical conditions, participated. Various modes of data collection were employed, namely semi‐participant observations, unstructured interviews, draw and write technique and a child‐friendly ‘stick a star’ quiz.

Results. The core concept to emerge was that of ‘visible‐ness’. ‘Visible‐ness’ existed along a continuum consisting of two polar ends, ‘being overshadowed’ and ‘being at the forefront’. These polar ends illuminated the degree to which children were, or wanted to be, included in the communication process and the extent to which children’s agenda was addressed.

Conclusion. This study provides empirical insight into children’s experiences of communication in an inpatient hospital setting. A key recommendation calls for the development of communication assessment strategies to determine the ‘ideal’ position children would like to occupy, at any given point in time, along the ‘visible‐ness’ continuum.

Relevance to practice. This study emphasises the need for all health professionals to embrace the individualism of each child patient with regard to their specific communication needs.
Does the perceived importance of a pain management task affect the quality of children’s nurses’ post‐operative pain management practices?
Authors: Twycross Alison
Published: November 2008

Aim.  To ascertain whether there is a relationship between the perceived importance of pain management tasks and the quality of an individual nurse’s practice.

Background.  The evidence to guide nurses’ pain management practices is readily available. However, children’s nurses’ pain management practices often fall short of the ideal. The (lack of) priority attributed to pain management has been suggested as one reason for this. However, this supposition has not previously been explored.

Design.  Participant observation.

Method.  Data were collected about children’s nurses’ (n = 13) post‐operative pain management practices on one children’s surgical ward in the English Midlands. Nurses (n = 12) also completed a questionnaire to provide a measure of the importance attributed to pain management tasks.

Results.  The questionnaire responses of individual participants (n = 12) were compared to the observational data. The perceived importance of a pain management task did not affect the likelihood of it being undertaken.

Conclusion.  Several explanations for these results have been put forward. It is apparent that the hypothesis, put forward in other studies that increasing the priority attributed to pain management will improve pain management practices may be overly simplistic.

Relevance to clinical practice.  The evidence to guide nurses’ pain management practices is readily available. However, children’s nurses’ pain management practices seem to fall short of the ideal. Possible reasons for this need to be explored so that practice can be improved.
Nursing work and the use of nursing time
Authors: Duffield Christine , Gardner Glenn , Catling‐Paull Christine
Published: November 2008

Aim. To find that changes in models of service delivery together with the dynamic nature of the contemporary health care context have changed the direction and focus of nurses’ work. The aim of this paper is to explore some of the drivers for change and their impact and recommend a way forward to optimising nurses’ work in the hospital environment.

Background. The healthcare workplace has been transformed over the past 20 years in response to economic and service pressures. However, some of these reforms have had undesirable consequences for nurses’ work in hospitals and the use of their time and skills.

Results. As the pace and complexity of hospital care increases, nursing work is expanding at both ends of the complexity continuum. Nurses often undertake tasks which less qualified staff could do while at the other end of the continuum, are unable to use their high level skills and expertise. This inefficiency in the use of nursing time may also impact negatively on patient outcomes.

Conclusions. Nurses’ work that does not directly contribute to patient care, engage higher order cognitive skills or provide opportunity for role expansion may decrease retention of well‐qualified and highly skilled nurses in the health workforce.

Relevance to clinical practice. In this climate of nursing shortages, we need to use nurses in a cost‐effective but also, intellectually satisfying manner, to achieve a sustainable nursing workforce.
An international hospital outcomes research agenda focused on nursing: lessons from a decade of collaboration
Authors: Clarke Sean P , Aiken Linda H
Published: November 2008

Aims.  To describe the origins, design and outcomes of an international hospital outcomes collaboration focused on nursing issues.

Background.  Across countries with different cultures and histories, nursing and healthcare leaders face similar issues with respect to workforce supply, quality and safety of care and financial constraints. Until researchers began using common research protocols to investigate structure, and outcomes variables in hospital nursing across countries, studying the aspects of work environments most important to patients and nurses in large numbers of hospitals was very difficult, if not impossible.

Method.  Review/essay.

Conclusions.  The international collaborations discussed in this article led by the University of Pennsylvania have found remarkable similarities in the experiences of hospital nurses across countries in terms of positive and negative aspects of their work, sizeable differences across hospitals within countries in working conditions and investments in high‐quality practice environments, and consistent evidence of connections between modifiable features of nurses’ work environments and both patient well‐being and factors influencing workforce stability.

Relevance to clinical practice.  International research collaborations allow benchmarking of countries and facilities within countries on work environment factors that are important to the provision of high quality nursing care. Results of this ongoing research initiative have helped strengthen the case that optimal management of practice environments for nurses in hospitals and other settings are a key strategy for optimising patient outcomes.
Transformative impact of Magnet designation: England case study
Authors: Aiken Linda H , Buchan James , Ball Jane , Rafferty Anne Marie
Published: November 2008

Aims. To test the impact of the implementation of Magnet principles of improving nurses’ work environments.

Background. Magnet hospital designation developed in the USA in the 1980s to recognise hospitals that had created excellent patient care environments and supported the professional practice of nursing. A pilot initiative in England was the first test of the applicability of Magnet standards outside the USA.

Methods. Research methods included surveys of nurses in the demonstration hospital in a predesign and postdesign and comparisons to survey results of nurses practicing in a national sample of 30 National Health Service Trusts.

Results. Prior to beginning the Magnet journey, the demonstration hospital had a nurse work environment that was somewhat less positive than the national sample NHS hospitals. Nurses practicing in the demonstration hospital were somewhat less satisfied with their jobs than nurses in other NHS hospitals. Following a two‐year period during which the evidence‐based Magnet standards were implemented and Magnet Designation was awarded, the quality of the nurse practice environment had improved significantly, as had job satisfaction of nurses and their appraisals of the quality of patient care. The quality of the nurse practice environment after Magnet designation was better than that of a national sample of NHS trusts. Improved nurse outcomes were because of the improved practice environment rather than staffing enhancements.

Conclusions. Implementation of the Magnet hospital intervention was associated with a significantly improved nursing work environment as well as improved job‐related outcomes for nurses and markers for quality of patient care.

Relevance to clinical practice. Nurses can use Magnet principles to improve the quality of their work environments.
Work–family conflict of nurses in Japan
Authors: Fujimoto Tetsushi , Kotani Sachi , Suzuki Rie
Published: November 2008

Aims and objectives.  The purpose of this paper is to explore the determinants of work–family conflict among Japanese nurses by using microdata describing nurses’ characteristics working at health facilities in Japan. We focus in particular on the impacts of shift work and workplace child care support on the conflict between work and child care with preschool children.

Background.  With a declining fertility trend, it is not easy to recruit sufficient number of nurses from the pool of graduate nurses. Therefore, support for reemployment of inactive nurses and prevention of turnover and enhancement of retention for active nurses have become the important strategies, along with the recruitment of new graduates.

Design and method.  We focus on the impacts of (i) flexibility in shift work and (ii) child care support at work, on the conflict between work and child care through performing multivariate regression analysis. The data used in this study come from a survey conducted on members of the Japanese Nursing Association as of the end of July 2001. Concerning shift work and child care support, we limited the sample to the full‐time female employees. The sample is limited to 378 respondents who were mothers of preschool children.

Result.  The results can be summarised as follows: (i) working night shifts does not have a significant effect on the conflict in balancing work and child care. Also findings show that three‐shift duty is more likely to increase the conflict. (ii) When supportiveness about child care responsibilities with small children is absent at work, the conflict is likely to increase. (iii) For mothers working night shifts, the reduction of the duties are likely to reduce the conflict.

Conclusion.  These results highlight the importance of establishing a system in which nurses can select the work hours flexibly and to promote awareness at work regarding the importance of child care support to strike balance between the nursing work and child‐raising.

Relevance to clinical practice.  The difficulty in balancing work and child care is one of the main factors that prevent inactive nurses from returning to work. Also, enrichment of child care support is important to reemploying inactive nurses. Therefore, revealing the difficulty that nurses experience in balancing work and child care, and the effectiveness of child care support for securing nursing labour, is highly relevant to clinical practice.
Career redevelopment programmes for inactive nurses in Japan
Authors: Tanaka Sachiko , Serizawa Takako , Sakaguchi Chizuru
Published: November 2008

Aims and objectives.  The purpose of this paper is to examine the challenges and problems in using career redevelopment programmes and individual hospital programmes to prepare inactive nurses to re‐enter into the workforce in Japan.

Background.  It is critical to supply sufficient skilled health human resources for medical care. Although, Japan has a mandatory retraining programme for supporting nurses to return to the workplace after a career break, it is unclear to what extent there are benefits to nurses from these programmes.

Design.  The research of career redevelopment programme was undertaken in three administrative divisions’ nurse centres in local prefecture A, B and C. A survey of nurses participating in the programme running in T Hospital was also conducted. The issues examined were the background and motivations of participants, the length of career break, the percentages returning to work and the effectiveness of each programme.

Result.  The average age of participants was 40 years, ranging widely from the 20–60 years. Local prefecture A tended to have narrower age range than others, namely from the 30–50 years. The average period of career break was around eight years at two of three. Length of experience was quite varied from entry level to 20 or 30 years in nursing. Feedback from nurses in the case study T Hospital suggests that the most effective ways of providing support through the programme was to meet the need for continuing support, including working styles after return to work and using the resources programme in their own area of domicile.

Relevance to clinical practice.  In the potential return of the nurse, the following are important: (i) job support system by using social resources effectively in the community level; and (ii) introduction of diverse working styles that take account of varying work‐life balance, as well as childcare support, by using existing facilities or human resources.
Direct observation of hygiene in a Peruvian shantytown: not enough handwashing and too little water
Authors: Oswald William E. , Hunter Gabrielle C. , Lescano Andres G. , Cabrera Lilia , Leontsini Elli , Pan William K. , Soldan Valerie Paz , Gilman Robert H.
Published: November 2008

Objective  To document frequency of hygiene practices of mothers and children in a shantytown in Lima, Peru.

Methods  Continuous monitoring over three 12‐h sessions in households without in‐house water connections to measure: (i) water and soap use of 32 mothers; (ii) frequency of interrupting faecal‐hand contamination by washing; and (iii) the time until faecal‐hand contamination became a possible transmission event.

Results  During 1008 h of observation, 55% (65/119) of mothers’ and 69% (37/54) of children’s faecal‐hand contamination events were not followed within 15 min by handwashing or bathing. Nearly 40% (67/173) of faecal‐hand contamination events became possible faecal‐oral transmission events. There was no difference in the time‐until‐transmission between mothers and children (P = 0.43). Potential transmission of faecal material to food or mouth occurred in 64% of cases within 1 h of hand contamination. Mean water usage (6.5 l) was low compared to international disaster relief standards.

Conclusions  We observed low volumes of water usage, inadequate handwashing, and frequent opportunities for faecal contamination and possible transmission in this water‐scarce community.
Cost‐effectiveness of specific immunotherapy with Grazax in allergic rhinitis co‐existing with asthma
Authors: Nasser S. , Vestenbæk U. , Beriot‐Mathiot A. , Poulsen P. B.
Published: November 2008

Background: In the United Kingdom, approximately 10.8 million people suffer from asthma, placing an economic burden on the society of more than £2 billion per year. For allergic asthma, treatment options consist of allergen avoidance, symptomatic treatment and allergen‐specific immunotherapy (SIT). Only SIT addresses the underlying cause of the disease, reducing symptoms and offering the potential for long‐term improvement. Grazax – the first tablet‐based SIT – is indicated for the treatment of patients with grass pollen‐induced rhinoconjunctivitis, including those with co‐existing asthma.

Objective: To assess the cost‐effectiveness of Grazax in patients with rhinoconjunctivitis and co‐existing asthma.

Methods: A prospective pharmacoeconomic analysis was carried out as part of a multinational clinical trial assessing the efficacy of Grazax (n = 79) compared with placebo (n = 72). Both groups had access to symptomatic medication; thus the placebo group represented current standard care. Pooled data on health resource use, productivity loss because of absence from work and quality of life (Quality Adjusted Life Years, QALYs) were collected in the trial. Reduced productivity at work was estimated from the literature. A societal perspective was adopted with a 9‐year time horizon. The NHS price of Grazax of £2.25 per tablet was used.

Results: The QALY gain was significantly higher for patients treated with Grazax than the placebo group receiving symptomatic medication alone (0.197 discounted QALYs gained 9 years into the future – equal to an extra 72 days of perfect health over 9 years). The levels of resource use and productivity loss were higher for the placebo group. As a result, the cost per QALY gained with Grazax was £4319, which is highly cost‐effective. Price sensitivity analyses demonstrated that Grazax remained cost‐effective up to a tablet price of £5.07.

Conclusion: SIT with Grazax is a cost‐effective strategy compared with standard management of patients with rhinoconjunctivitis and co‐existing asthma.
Gene expression measurements in the context of epidemiological studies
Authors: Bieli C. , Frei R. , Schickinger V. , Steinle J. , Bommer C. , Loeliger S. , Braun‐Fahrländer C. , Von Mutius E. , Pershagen G. , Lauener R.
Published: November 2008

Background:  Gene expression measurements became an attractive tool to assess biological responses in epidemiological studies. However, collection of blood samples poses various technical problems.

We used gene expression data from two epidemiological studies to evaluate differences between sampling methods, comparability of two methods for measuring RNA levels and stability of RNA samples over time.

Methods:  For the PARSIFAL study, PBLC of 1155 children were collected using EDTA tubes in two countries. In the PASTURE study, tubes containing RNA‐stabilizing solutions (PAXgene® Blood RNA Tubes; PreAnalytiX) were used to collect cord blood leucocytes of 982 children in five countries. Real‐time PCR (conventional single tube assay and high‐throughput low density arrays) was used to quantify expression of various innate immunity genes. In 77 PARSIFAL samples, gene expression was measured repeatedly during prolonged storage.

Results:  In PARSIFAL (EDTA tubes) the median RNA yield after extraction significantly differed between the two centres (70 and 34 ng/μl). Collecting blood into an RNA‐stabilizing solution markedly reduced differences in RNA yield in PASTURE (range of medians 91–107 ng/μl). The agreement [Spearman rank correlation (r)] between repeated measurements of gene expression decreased with increasing storage time [e.g., for CD14: r (first/second measurement) = 0.35; r (first/third measurement) = 0.03]. RNA levels measured with either the conventional method or low‐density arrays were comparable (r > 0.9).

Conclusion:  Collecting blood samples into tubes containing an RNA‐stabilizing solution increases RNA yield and reduces its variability. Long‐term storage of samples may lead to RNA degradation, requiring special attention in longitudinal studies.
Budesonide/formoterol for maintenance and reliever therapy in the management of moderate to severe asthma
Authors: Humbert M. , Andersson T. L. G. , Buhl R.
Published: November 2008

The Global Initiative for Asthma (GINA) guidelines aim at improving asthma control and preventing future risk. For patients with moderate to severe asthma an inhaled corticosteroid (ICS) or an ICS/long‐acting β2‐agonist (LABA) combination with a short‐acting β2‐agonist (SABA) as reliever is recommended. Despite the availability of effective maintenance therapies, a large proportion of patients still fail to achieve guideline‐defined asthma control, and overuse of SABA reliever medication at the expense of ICS is commonly observed. New simplified treatment approaches may offer a solution and assist physicians to achieve overall asthma control. One such treatment approach, which is recommended in the GINA guidelines, is budesonide/formoterol for both maintenance and reliever therapy. This treatment strategy significantly reduces the rate of severe asthma exacerbations compared with ICS/LABA plus SABA and achieves equivalent daily symptom control compared with higher doses of ICS/LABA plus separate SABA for relief. These benefits are achieved at a lower overall steroid load, and budesonide/formoterol maintenance and reliever therapy is well tolerated in patients with moderate to severe asthma. This review discusses current asthma management in patients with moderate to severe disease and examines the evidence for alternative asthma management approaches.
Clinical xenotransplantation
Authors: Starzl Thomas E. , Murase Noriko , Tzakis Andreas , Fung John J. , Todo Satoru , Demetris Anthony J. , Manez Rafael , Marino Ignazio R. , Valdivia Luis
Published: November 2008

Abstract: Two baboon liver xenografts transplanted to patients with B virus hepatitis supported life for 70 and 26 days but did not function optimally despite minimum or no histopathologic findings of overt humoral or cellular rejection in serial biopsies. However, there was evidence of complement activation in both cases, which in retrospect was thought to explain the unsatisfactory outcome. Strategies to deal with this problem are discussed.
Kinetics and character of xenoantibody formation in diabetic patients transplanted with fetal porcine islet cell clusters
Authors: Satake Masahiro , Kumagai‐Braesch Makiko , Kawagishi Naoki , Tibell Annika , Groth Carl‐Gustav , Moller Erna
Published: November 2008

Abstract:Porcine fetal islet‐like cell clusters (ICC) were transplanted to 10 renal transplant patients suffering from long‐standing type I diabetes. Since they had renal grafts, they were given immunosuppression with cyclosporine, prednisolone and azathioprine. Eight patients had the ICC injected intraportally and two had the ICC placed under the renal graft capsule. At the time of the xenotransplantation, ATG or 15‐deoxyspergualin was given as an adjunct. Evidence of engraftment, as reflected by excretion of small amounts of porcine C‐peptide into the urine, was observed in four of the patients. In all patients, irrespective of the type of immunosuppression given and whether graft function was established or not, specific xenoantibodies were formed. Titer increases in lymphocytotoxic antibodies occurred after 10 to 14 days with peak reactivity after 30 to 50 days. High titers of ADCC activity measured against porcine lymphoblasts were found in all patients. Titers were maintained at a high level for at least 100 days. Antibody titers were monitored against pig lymphocytes, erythrocytes and against pig membrane antigens solubilized from peripheral blood mononuclear cells, platelets and erythrocytes. Both IgM and IgG antibodies were formed with identical kinetics. There was no increase in the titers of alloantibodies, as evidenced by panel‐reactive lymphocytotoxic antibodies. In all patients an increase in titers of isohemagglutinins was recorded, especially against blood group B antigens. Absorption studies showed that xenoreactivity present in healthy individuals could not be blocked by absorption with human RBC. However, in all transplanted patients, xenoreactivities against pig antigens were inhibited by absorption with human RBC, in particular with B‐type RBC. These data show that the increase in isohemagglutinins was probably due to cross‐reactivity with xenogeneic antigens. Using an ELISA assay, increased antibody titers were also recorded against purified pig MHC class I antigens. However, as is shown in the accompanying paper (next issue), these antibodies were probably not directed against protein determinants on the MHC molecules but rather against glycosylated side chains of these molecules.
Miniature swine as organ donors for man: Strategies for prevention of xenotransplant‐associated infections
Authors: Fishman Jay A.
Published: November 2008

Abstract: Xenotransplantation could potentially overcome limitations in organ transplantation resulting from a shortage of donor organs. Transplantation from miniature swine raises concerns over the potential introduction of new infectious agents into humans. These “direct zoonotic infections” or “xenoses” derived from swine fall into four categories: (1) microbial agents known to cause infection in humans (traditional zoonoses);(2) “species specific” organisms restricted to infection of the donor xenograft tissues by the absence of receptors or other factors needed for growth in human cells;(3) organisms of broad “host range” capable of infection of tissues outside the xenograft in the immunocompromised transplant recipient;and (4) organisms, such as retroviruses, of unknown quantity and with unmeasured capacity for causing disease in humans. The behavior of donor‐derived xenoses in immunocompromised xenotransplant recipients cannot be predicted. The ability of human‐derived microbial agents to infect porcine xenografts, and the capacity of the human immune system to inhibit such infections, also merit investigation. Experimental assessment of the infectious disease risks associated with xenotransplantation is important and practical.
The alginate‐poly‐L‐lysine‐alginate membrane: Evidence of a protective effect on microencapsulated islets of Langerhans following exposure to cytokines
Authors: Tai Isabella T. , Vacek Ivan , Sun Anthony M.
Published: November 2008

Abstract: In past experiments, we demonstrated that allografts and xenografts of pancreatic islets encapsulated in alginate‐polylysine‐alginate (APA) microcapsules were protected from immunorejection and that in both streptozotocin‐induced and spontaneously diabetic animals diabetes was reversed for extended periods of time. Because of growing evidence that cytokines may play an important role in graft rejection, it is important to determine whether the APA capsular membrane can also provide a protective barrier against cytotoxic actions of cytokines. In this study, free and encapsulated rat islets were exposed in vitro to interleukin 1, 2, and 6 (IL‐1, IL‐2, and IL‐6) to tumor necrosis factor (TNF) and interferon (INT), then challenged with 20 mM glucose for 24 hr to evaluate physiological response in terms of insulin secretion. Although IL‐2 and 6 were found to have no effect on the pancreatic islets (free or encapsulated), IL‐1, TNF, and INT were shown to interfere with the physiological pattern of insulin secretion from the free islets; microencapsulated islets' function was not affected. Transmission electron microscopy (TEM) of the rat islets exposed to the five types of cytokines revealed that IL‐1, TNF, and INF exerted morphological changes to the free islets while encapsulated islets were not affected. No changes were detected in free or encapsulated islets exposed to IL‐6 or IL‐2. In addition, encapsulated islets were transplanted into normal BALB‐c mice and into spontaneously diabetic NOD mice for 3 to 5 months and then recovered. The recovered islets were shown to continue to respond to glucose challenge in a physiological manner. The results of this study showed that, although exposure of some cytokines to free islets results in changes in the normal physiological response of the islets to glucose challenge as well as in ultrastructural changes within the cells, microencapsulated islets were not impaired by the exposure to the same cytokines.
Evidence for nonimmune mechanisms in the loss of hematopoietic chimerism in rat→mouse mixed xenogeneic chimeras
Authors: Lee Lorri A. , Sergio Justin J. , Sykes Megan
Published: November 2008

Abstract: We have recently described a relatively nontoxic, nonmyeloablative conditioning regimen allowing engraftment of T cell‐depleted (TCD) rat bone marrow in mice, leading to a state of mixed xenogeneic chimerism and donor‐specific skin graft tolerance, apparently by a deletional mechanism. The conditioning regimen involves depletion of host T and NK cells with mAbs, followed by administration of 7 Gy thymic irradiation (TI) and 3 Gy whole body irradiation (WBI) prior to transplantation of TCD F344 rat bone marrow cells (BMC). Although the percentage of rat cells gradually declines over time post‐BMT in these animals, they demonstrate prolonged survival of donor‐specific rat skin grafts and an absence of anti‐rat antibody responses long after this decline is underway. We therefore hypothesized that the loss of rat hematopoietic repopulation may not be due to a loss of tolerance at the T cell or B cell level. We have now evaluated the effect of a repeat, late, donor marrow infusion on chimerism and tolerance. Treatment with 3 Gy WBI followed by TCD rat marrow infusion at 22 weeks following the original BMT led to a marked increase in rat cell repopulation of both myeloid and lymphoid lineages and prolonged the period of complete central and peripheral deletion of Vp5+ and Vβ11+ host T cells, which recognize endogenous (presumably mouse) superantigens presented by rat hematopoietic cells. Furthermore, the second marrow infusion did not induce a cytotoxic antibody response to rat marrow. Since these results suggested that the decline in rat chimerism in our model was not associated with a loss of T cell or B cell tolerance to the donor, we evaluated the possibility that a failure of NK cell tolerance led to the decline by comparing chimerism in animals receiving chronically NK cell‐depleting mAb and controls. Chronic NK depletion did not markedly enhance the level of rat repopulation in any lineage. Together, our results are most consistent with the interpretation that the gradual decline in rat repopulation in our chimeras reflects a competitive advantage of host hematopoietic cells over xenogeneic cells rather than immune‐mediated rejection, possibly due to species selectivity of cytokines and adhesion molecule interactions of hematopoietic progenitors and the marrow microenvironment. This host hematopoietic advantage might be counteracted by repeat donor‐specific marrow infusions.
Detection, immunoabsorption, and inhibition of cytotoxic activity of anti‐αGal antibodies using newly developed substances with synthetic Gal α1–3Gal disaccharide epitopes
Authors: Rieben Robert , von Allmen Edith , Korchagina Elena Y. , Nydegger Urs E. , Neethling Francisca A. , Kujundzic Milan , Koren Eugen , Bovin Nicolai V. , Cooper David K.C.
Published: November 2008

Abstract:The presence of naturally occurring anti‐Galα1–3Gal (anti‐αGal) antibodies in human serum is believed to be a major factor in the hyperacute rejection of discordant organ xenografts such as the pig‐to‐human combination. Galα1–3Gal epitopes are expressed on pig tissues and the binding of anti‐αGal leads to endothelial cell activation and complement‐mediated, hyperacute graft rejection. One possible method to overcome this problem is to absorb anti‐αGal antibodies from the plasma of the xenograft recipient using a suitable immunoabsorbent or to interfere with their binding to tissues and thus prevent their cytotoxic activity by the intravenous injection of soluble antigen. We describe here the use of new synthetic antigens containing the Galα1–3Gal disaccharide (Bdi) epitope. Soluble conjugates of the Bdi with polyacrylamide (PAA‐Bdi) were used as coating antigens for an anti‐αGal ELISA as well as for in vitro inhibition of the cytotoxicity of anti‐αGal. An immunoabsorbent consisting of PAA‐Bdi coupled to macroporous glass (Sorbent Bdi) was tested for absorption of anti‐αGal from human serum.

Anti‐αGal IgM, IgG and IgA could be detected by the anti‐αGal ELISA and were specifically absorbed by Sorbent Bdi with absorption efficiencies ranging from 70 to 50% for anti‐αGal IgG and 60 to 25% for anti‐αGal IgM. A comparison of the anti‐αGal absorption by Sorbent Bdi and rabbit red blood cells revealed a qualitatively (isotype distribution) and quantitatively similar pattern. Nonspecific absorption by Sorbent Bdi was low, as detected by the reduction of anti‐A trisaccharide antibodies. The cytotoxic effect of human serum on pig kidney (PK15) cells was almost totally inhibited by the addition of synthetic B disaccharide or by adsorption of the serum through immunoaffinity columns of PAA‐Bdi. We conclude that the newly developed, synthetic αGal1–3Gal antigens are suitable for the detection and immunoabsorption or inhibition of anti‐αGal antibodies.
Evidence for an antigen‐release induced cellular immune response against alginate‐polylysine encapsulated islets
Authors: Zekorn Tobias D.C. , Endl Ulrich , Horcher Andrea , Siebers Ulrike , Bretzel Reinhard G. , Federlin Konrad
Published: November 2008

Abstract: For almost 15 years microencapsulated islets have been successfully transplanted in different animal models. Besides long‐lasting success, a certain rate of graft failures also has been reported. This study evaluated the cellular immune response toward alginate‐polylysine microencapsulated islets (mc‐islets) in vitro by means of mixed‐lymphocyte‐islet‐culture. Method: Islets were isolated from LEWIS‐rats and lymphocytes from the spleens of NMRl‐mice. After overnight culture and prior to encapsulation the islets were gamma‐irradiated with 22.5 Gy. 50 mc‐islets, 50 nonencapsulated islets, and 50 empty me were co‐cultured for 72 h with 1 × 106 in 1 ml medium in 24‐well plates. Thymidine incorporation during the last 24 hr served as a measure for lymphoid activation. Result: Non‐encapsulated islets were potent stimulators of lymphoid proliferation. This could be reduced by 55% when the islets were entrapped in microcapsules. Empty microcapsules induced a minor lymphoid activation (18% of mc‐islets) only. Conclusion: Despite encapsulation islets could be recognised by lymphocytes in vitro. This may explain at least partially graft failure rates after transplantation of encapsulated islets.
Adult pigs as a source of insulin‐producing tissue for xenotransplantation: Islet separation technology
Authors: Inverardi Luca , Ricordi Camillo
Published: November 2008

Abstract: Porcine pancreata have been extensively studied as a source of insulin‐producing tissue for human transplantation. Substantial technical problems hampered the development of reproducible techniques for islet separation from the adult pig pancreas. Since the introduction of the automated method for human islet transplantation, many steps have been implemented to optimize this method and to adapt it to the requirements of porcine islet isolation. This paper describes the protocols now widely used for adult porcine islet separation and summarizes some of the key variables that influence reproducibility and islet isolation outcome.
Purified enzymes In pig pancreas dissociation for islet Isolation: Preliminary observations
Authors: van Suylichem Paul T.R. , Johnson Paul R.V. , Vos‐Scheperkeuter Greetje H. , Vonk Maike W.A. , Roberts Darren L. , London Nick J.M. , van Schiifgaarde Reinout
Published: November 2008

Abstract: We have previously shown that high islet yields are obtained by digesting the rat pancreas with a defined mixture of purified collagenase and protease. In this study we investigate whether a similar approach may be applied to the pig pancreas. We have used a method for the in vitro evaluation of different enzymes on a single pancreas that was recently developed in our laboratories. Blocks of pig pancreas were placed in centrifuge tubes and incubated in a waterbath at 35°C in Hanks containing either i) crude collagenase, ii) purified collagenase obtained from the crude collagenase by chromatography or iii) purified collagenase and protease, at comparable collagenolytic and proteolytic activities. Samples were assessed for number of clean islets, cleavage index, islet integrity, and degree of exocrine dissociation. The experiments were performed on five pig pancreata. The results do not indicate a clearcut advantage of one of the enzyme formulas. There is considerable variation in results of different experiments with the same enzyme formula. The parameters mainly indicate that a substantial number of pig pancreatic islets may be neatly liberated from the exocrine tissue without adherent exocrine tissue. They also indicate, however, that these islets are readily subject to fragmentation with any of the three enzyme formulas tested. In conclusion, the pig pancreas can be dissociated with purified enzymes, which warrants further investigation since the variable composition of crude collagenase contributes to the poor reproducibility of islet isolation procedures.
Genetic engineering of endotheiial cells
Authors: Winkler Hans , Wrighton Christopher , Anrather Josef , Brostjan Christine , McShea Andrew , Bach Fritz H.
Published: November 2008

Abstract: Endotheiial cell activation is a major obstacle to successful xenotransplantation. The activated phenotype is largely based on the transcriptional induction of a number of genes and their products. Due to the large number of new gene products in activated endotheiial cells, it is not feasible to target each of them individually for therapeutic intervention. A common factor important for the induction of many, if not all, genes induced upon endotheiial cell activation if NF‐KB. It is thus a reasonable target for inhibition if one is to attempt to inhibit endotheiial cell activation genetically. Donor animals for xenotransplantation are amenable to genetic manipulation and we believe that transgenic animals carrying several transgenes will be the standard of future experimental and clinical xenotransplantation.
Transplantation of porcine islets in nude mice: Implications for islet replacement therapy in humans
Authors: Weir Gordon C. , Davaili Alberto M. , Ogawa Yoshiji , Scaglia Luisa , Wu Ying‐Jian , Hollister Jennifer , Bonner‐Weir Susan
Published: November 2008

Abstract: Porcine islets obtained from adult donors were transplanted under the kidney capsule of streptozotocin diabetic nude mice. Over a period of 30 days or more, blood glucose levels fell to values lower than those of normal mice but comparable to those of normal pigs; this change in the mice was probably being driven by a lower set point for glucose‐induced insulin secretion of porcine islets. Oral and intraperitoneal glucose tolerance tests had lower glucose profiles than those carried out in control mice. The mass of beta cell tissue in the porcine islet graft that cured the diabetes was about 1 mg, close to the normal beta cell mass of a mouse pancreas. When graft‐bearing kidneys were perfused in situ, there was a marked increase of insulin secretion to challenges with glucose and arginine. These results suggest that porcine islets could be a good source of tissue for human islet replacement therapy. Some of the ramifications of this possibility are discussed.
Tolerance across discordant xenogeneic barriers
Authors: Sachs David H. , Sablinski Tomasz
Published: November 2008

Abstract:In contrast to islet transplants, which appear to enjoy privileged survival when transplanted across some species barriers, organ xenografts are subject to vigorous immunologic rejection. Part of this rejection is immediate and is caused by the binding of natural antibodies to vascular endothelial cells, followed by activation of complement and coagulation factors, and hyperacute destruction of the graft. Such hyperacute rejection, in a pig‐to‐monkey kidney model that we are studying, can be avoided by removal of natural antibodies, which we have accomplished by absorption procedures. However, the cellular immune response to xenografts is also stronger than that to allografts. One might therefore expect the amount of nonspecific immunosuppression that would be required to avoid xenograft rejection to be so great that recipients would succumb to infectious complications. For this reason, we have pursued an approach to discordant xenografting involving the induction of tolerance though establishment of mixed lymphohematopoietic chimerism. We summarize here the present status of these experiments.
Inhibition of human anti‐αGal IgG by oligosaccharides derived from porcine stomach mucin
Authors: Li Shifeng , Yeh Jiunn‐chern , Cooper David K.C. , Cummings Richard D.
Published: November 2008

Abstract: We now report that neutral oligosaccharides derived from porcine stomach mucin (PSM) are potent inhibitors of human anti‐αGal antibodies, which are the major cause of hyperacute vascular rejection following discordant organ xenotransplantation. The O‐linked oligosaccharides of PSM were released through β‐elimination, and neutral oligosaccharides were obtained. In ELISA these oligosaccharides inhibited the binding of purified anti‐αGal IgG to mouse laminin, α glycoprotein known to contain α‐galactosyl determinants. Treatment of oligosaccharides with a‐galactosidase, but not β‐galactosidase, abolished their inhibitory activity. The oligosaccharides were size‐fractionated on a column of Bio‐Gel P‐6, and it was found that the larger oligosaccharides were more potent than the smaller in inhibiting the anti‐αGal IgG. Less than 1 % of the total oligosaccharides from PSM bound to a column containing immobilized anti‐αGal IgG. These bound oligosaccharides were nearly 1,000‐fold more potent than the unbound oligosaccharides in inhibiting anti‐αGal antibody. It may be possible to overcome the hyperacute vascular rejection of discordant organ xenotransplants by using these affinity‐purified oligosaccharides from PSM in immunoaffinity columns or as a continuous intravenous infusion.