Palliative Education and Care for the Homeless (PEACH): A Model of Outreach Palliative Care for Structurally Vulnerable Populations

The Palliative Education and Care for the Homeless (PEACH) program comprises a community palliative care team serving some of the most complex clients in the healthcare system. Formal partnerships bring together physician, nursing, psychosocial and homecare, health and housing navigation supports. PEACH has served over 1,000 clients, leading field-defining research, medical education and public advocacy. The PEACH program demonstrates that innovation through deep interorganizational and intersectoral integration can drive value-based impact for the most complex clients, providing instructive lessons for public health system reform well beyond the margins faced by people who are unhoused. This paper describes how PEACH's unique model, critical community partnerships and research have been necessary for it to become a leader in community-based palliative care for structurally vulnerable people.

Exploring the Barriers and Facilitators Experienced by Palliative Health Care Providers Working with Patients Experiencing Homelessness during the COVID-19 Pandemic

Background

Patients experiencing homelessness not only have higher rates of medical complexity, comorbidity, and mortality, but also face barriers to accessing palliative care services. In structurally vulnerable populations with palliative care needs, these barriers are compounded, creating significant challenges for both patients and providers that have important health equity implications.

Objective

The aim is to explore the experiences of palliative care providers working with patients experiencing homelessness during the COVID-19 pandemic and understand the barriers they faced in providing care, as well as facilitators that aided in the success of their teams.

Methods

Seven health care providers from two Canadian palliative outreach teams involved in delivering palliative care services to patients experiencing homelessness during the COVID-19 pandemic participated in audio-recorded and transcribed videoconferencing interviews. Analysis was completed using generic descriptive thematic analysis.

Results

Five key themes were identified: (1) factors negatively impacting patient health, (2) use of technology, (3) care provider emotions, (4) care provider education and advocacy, and (5) outreach team factors.

Conclusion

Identified barriers during the pandemic included worsening of existing patient vulnerabilities, as well as challenges incorporating technology into care. Providers faced increased emotional burden, with a rise in workload, stress, fear, and grief. However, several facilitators allowed teams to provide high-quality care to this vulnerable population, including team support, interprofessional collaboration, and advocacy and education initiatives. The outreach model also proved to be a highly flexible, resilient, and adaptable model for providing care during the COVID-19 pandemic.

Assessing the impact of a health navigator on improving access to care and addressing the social needs of palliative care patients experiencing homelessness: A service evaluation

BACKGROUND

Health navigators are healthcare professionals who specialize in care coordination, case management, navigating transitions, and reducing barriers to care. There is limited literature on the impact of health navigators on community-based palliative care for people experiencing homelessness.

AIM

We devised key performance indicators in nine categories with the aim to quantify the impact of a health navigator on the delivery of palliative care to patients experiencing homelessness.

DESIGN

Data were collected prospectively for all patient encounters involving a health navigator from July 2020 to 2021 and reviewed to determine the distribution of the health navigator's role and the ways in which patient care was impacted.

SETTING AND PARTICIPANTS

This study was conducted in Toronto, Ontario with the Palliative Education and Care for the Homeless (PEACH) Program. At any one time, the PEACH health navigator served a total of 50 patients.

RESULTS

We identified five key areas of the health navigator role including (1) facilitating access (2) coordinating care (3) addressing social determinants of health (4) advocating for patients, and (5) counselling patients and loved ones. The health navigator role was split evenly between activities pertaining to palliative care for structurally vulnerable populations and community-based palliative care for the general population. To achieve high impact outcomes, a considerable investment of time and energy was required of the health navigator, speaking to the importance of adequate and sustainable funding.

CONCLUSIONS

These findings underscore the potential for health navigators to add value to community-based palliative care teams, especially those caring for structurally vulnerable populations.

Factors That Determine the Experience of Transition to an Inpatient Palliative Care Unit for Patients and Caregivers: A Qualitative Study

Objective: Transitions in care settings near the end of life can present challenges to patients and families, especially when there are also adjustments in level of care and illness trajectory. In this study, we explored what factors influenced how patients and family caregivers experienced a transition to an inpatient Palliative Care Unit (PCU). Methods: This qualitative study was conducted at a PCU in Toronto, Canada. Semi-structured interviews were held with 29 participants (14 patients and 15 family caregivers) during their time on the PCU. Data was analyzed through an iterative process of constant comparison to generate themes. The recruitment process continued to the point of thematic saturation. Results: Five themes were identified that represented the participants’ experiences in transitioning to the PCU: Being prepared, Feeling supported, Coming to terms with end of life issues, Dealing with uncertainty, and Continuity of care. Conclusions: Our findings highlight the need for clear and iterative communication with patients and family caregivers during the transition to a PCU. Identification and consideration of the common themes involved in the experience of transfer to PCU can help guide future practice and improve the experience of patients and families during transitions at the end of life.

PPARγ inhibits breast cancer progression by upregulating PTPRF expression

OBJECTIVE

Peroxisome proliferator-activated receptor γ (PPARγ) regulates fatty acid storage and glucose metabolism. Recently, PPARγ has been reported to be involved in cancer. The present study reported a PPARγ consensus binding site (AGGTCA) in the ptprf promoter and identified a strong association between PPARγ and PTPRF expression, as well as their tumor suppressor roles in a v-Ha-Ras-induced model of breast cancer.

MATERIALS AND METHODS

The prognostic potential of PPARγ was assessed with a KM analysis of raw data from 3,951 breast cancer patients. The expression of PPARγ and PTPRF in the rat breast cancer cell lines was detected by Western blot and qPCR. The impact of PPARγ on cancer cell migration, invasion, and growth was confirmed using cell migration assay, transwell cell invasion assay, tri-dimensional soft agar culture, respectively. The binding of PPARγ with the ptprf promoter was then examined using electrophoretic mobility shift assay. The inhibitory effect of PPARγ on tumor growth was then examined in mouse tumor model in vivo.

RESULTS

It was identified that PPARγ expression is lost in the aggressive v-Ha-Ras-induced breast cancer cell line FE1.2 but highly expressed in less malignant FE1.3 cells. Exogenous expression of PPARγ in FE1.2 cells (FE1.2-PPARγhi) resulted in a marked inhibition of proliferation compared with that in FE1.2-Vector control group. FE1.2-PPARγhi cells also exhibited reduced migration, invasion, and colony formation abilities compared with those of the controls. The PPARγ agonist rosiglitazone also suppressed the malignant properties of FE1.2 cells. Protein tyrosine phosphatase receptor F (PTPRF), a downstream target of PPARγ, was markedly induced in FE1.2-PPARγhi cells. A PPARγ consensus binding site (AGGTCA) was identified in the ptprf promoter, and an electrophoretic mobility shift assay confirmed that PPARγ bind to this promoter. Similar to the effect of vector-mediated overexpression of PPARγ, ectopic overexpression of PTPRF in FE1.2 cells led to reduced proliferation. Furthermore, a PPARγ antagonist (GW9662) and PTP inhibitor (NSC87877) abrogated the suppressive function of PPARγ and PTPRF in FE1.2 cells, respectively. PPARγ overexpression or activation suppressed the progression and distant organ metastasis of breast cancer cells in a NOD/SCID mouse model.

CONCLUSIONS

These results suggest that PPARγ inhibits tumor cell proliferation, at least in part, through direct regulation of the ptprf gene and that PPARγ is a potential target for breast cancer treatment.

Management of Traumatic Hip Fracture in the Palliative Care Unit

We report on the case of an elderly patient in a palliative care unit who fell and sustained a hip fracture. Hip fractures are potentially terminal events for elderly patients with other life-limiting conditions. The case highlights the need for more evidence to determine the best approach to care for hip fractures in patients who are in the final weeks or months of life.

Use of Standardized Assessment Tools to Improve the Effectiveness of Palliative Care Rounds: A Quality Improvement Initiative

BACKGROUND

Optimal care for patients in the palliative care setting requires effective clinical teamwork. Communication may be challenging for health-care workers from different disciplines. Daily rounds are one way for clinical teams to share information and develop care plans for patients.

OBJECTIVE

The objective of this initiative was to improve the structure and process of daily palliative care rounds by incorporating the use of standardized tools and improved documentation into the meeting. We chose a quality improvement (QI) approach to address this initiative. Our aims were to increase the use of assessment tools when discussing patient care in rounds and to improve the documentation and accessibility of important information in the health record, including goals of care.

METHODS

This QI initiative used a preintervention and postintervention comparison of the outcome measures of interest. The initiative was tested in a palliative care unit (PCU) over a 22-month period from April 2014 to January 2016. Participants were clinical staff in the PCU.

RESULTS

Data collected after the completion of several plan-do-study-act cycles showed increased use and incorporation of the Edmonton Symptom Assessment System and Palliative Performance Scale into patient care discussions as well as improvement in inclusion of goals of care into the patient plan of care.

CONCLUSION

Our findings demonstrate that the effectiveness of daily palliative care rounds can be improved by incorporating the use of standard assessment tools and changes into the meeting structure to better focus and direct patient care discussions.

Earliness per se QTLs and their interaction with the photoperiod insensitive allele Ppd-D1a in the Cutler × AC Barrie spring wheat population

Earliness per se regulates flowering time independent of environmental signals and helps to fine tune the time of flowering and maturity. In this study, we aimed to map earliness per se quantitative trait loci (QTLs) affecting days to flowering and maturity in a population developed by crossing two spring wheat cultivars, Cutler and AC Barrie. The population of 177 recombinant inbred lines (RILs) was genotyped for a total of 488 SSR and DArT polymorphic markers on all 21 chromosomes. Three QTLs of earliness per se affecting days to flowering and maturity were mapped on chromosomes 1B (QEps.dms-1B1 and QEps.dms-1B2) and 5B (QEps.dms-5B1), in individual environments and when all the environments were combined. A QTL affecting flowering time (QFlt.dms-4A1) was identified on chromosome 4A. Two grain yield QTLs were mapped on chromosome 5B, while one QTL was mapped on chromosome 1D. The population segregated for the photoperiod insensitive gene, Ppd-D1a, and it induced earlier flowering by 0.69 days and maturity by 1.28 days. The photoperiod insensitive allele Ppd-D1a interacted in an additive fashion with QTLs for flowering and maturity times. The earliness per se QTL QFlt.dms-5B.1 inducing earlier flowering could help to elongate grain filling duration for higher grain yield. Hence, chromosome 5B possesses promising genomic regions that may be introgressed for higher grain yield with earlier maturity through marker-assisted selection in bread wheat.

Lenalidomide (L) induces high response rates with molecular remission in patients (pts) with relapsed (rel) or refractory (ref) chronic lymphocytic leukemia (CLL)

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Background: Tumor microenvironment (ME) is critical in CLL pathogenesis. Targeting the ME is a novel approach in CLL therapeutics. Lenalidomide (Revlimid, L) is an immunomodulating agent (IMiD), approved for pts with transfusion-dependent low or intermediate-1 risk myelodysplastic syndrome with deletion 5q cytogenetic abnormality. Its antitumor activity is possibly mediated through (a) downregulation of cytokine(s) - TNF-α, VEGF, PDGF and IL-6 and/or (b) activation of immune effector cells (T & NK cells). We investigated its antitumor activity in rel/ref CLL pts. Here we present the final results of the first cohort of pts treated with 25mg daily dose of L. Methods: Oral L was given at 25mg/day for 21 out of a 28 day cycle. Anti-leukemic effects were recorded after each cycle using NCI-WG 1996 criteria. Treatment was continued until molecular complete response (mCR) or progressive disease (PD). Those with PD were then treated with L in combination with rituximab (reported separately). Polymerase chain reaction (PCR) for immunoglobulin heavy chain gene was used to determine molecular remission (mCR). Results: Twenty-nine pts (median age 64 years; range: 47–75) have been enrolled. Toxicity is reported on all, while response on 19 evaluable pts. Nine pts are inevaluable (2 withdrew consent and 5 received < 2 months of therapy due to toxicity). Major response was noted in 13 of 19 evaluable pts (68%) with 3 CR (2 mCR) and 10 PR. Toxicity: Most common grade 3/4 adverse effects (AE) were neutropenia (60%) and thrombocytopenia (55%). Another common AE was tumor flare (79%); characterized by tender swelling of lymph nodes and/or rash, noted in almost all pts. Conclusions: L at 25mg/day dose given on days 1–21 in a 28 day cycle yields high ORR including mCR in rel/ref CLL. Hematologic toxicity was the most common AE requiring dose reduction. Overall safety profile was predictable and manageable. A slow dose escalation schema, starting at 15mg is being investigated.

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Residual metabolizable energy intake and its association with diet and test duration

The objective was to determine if end-of-test residual metabolizable energy intake (RMEI) is correlated with RMEI values calculated earlier in the test on steers fed two forage (silage) or four forage-grain diets. As the days on test increased the variation in RMEI decreased in all diets. In all but the 85% alfalfa + 15% barley grain diet, test duration for RMEI may be reduced from 105 to 84 d. In the 100% alfalfa silage diet, it may be further reduced from 105 to 63 d (Spearman r = 0.90; Pearson r = 0.94; P < 0.01). The duration of testing required to obtain reliable estimates of RMEI may therefore also depend on the type of diet being fed. Key words: Residual metabolizable energy intake, crossbred steers, correlations, forage-grain diets, test duration

Bone marrow aspirates as part of routine donor assessment for allogeneic blood and marrow transplantation can reveal presence of occult hematological malignancies in otherwise asymptomatic individuals

Pre transplant screening work-up of donors for allogeneic blood and marrow transplantation is essential in an effort to minimize risks to the recipient and protect the donor. At Princess Margaret Hospital, every potential donor is screened with a bone marrow aspirate. The case histories of three asymptomatic potential donors who presented within 1 year with normal complete blood counts, history and physical examination are presented. A 65-year-old male patient was diagnosed with smouldering multiple myeloma, a 72-year-old male patient with chronic lymphocytic leukemia and a 42-year-old male patient with myelodysplastic syndrome. Bone marrow examination led to the diagnosis in each one of these cases. Of note is that each of the potential donors was discovered to have the same disease as the transplant recipient. In vitro clonogenic hemopoietic progenitor assays were compared to those of 20 normal volunteers. Inferior growth of hemopoietic progenitor colonies in all three was noted. In conclusion, particularly in older donors and donors with potential for familial malignancies, more screening investigations including bone marrow aspiration may be reasonable to investigate for occult hematological malignancies prior to stem cell donation. Clonogenic assays can contribute to detect hemopoietic abnormalities pre transplant.

Intensive chemotherapy and autologous stem-cell transplantation plus rituximab is superior to conventional chemotherapy for newly diagnosed advanced stage mantle-cell lymphoma: a matched pair analysis

BACKGROUND

The outcome of 20 patients with newly diagnosed mantle-cell lymphoma (MCL) treated on a prospective trial of autologous stem-cell transplantation (ASCT) and rituximab immunotherapy was compared with the outcome of 40 matched historical control patients treated with standard combination chemotherapy.

PATIENTS AND METHODS

Control patients with MCL were identified from a lymphoma database, and pairs were matched with patients receiving ASCT-rituximab for stage of disease, gender and age (+/-5 years). Only patients treated with an anthracycline- or cyclophosphamide-fludarabine-based regimen were included.

RESULTS

Seventeen of 20 patients who received ASCT-rituximab remain alive in remission at a median of 30 months from diagnosis; one patient relapsed 2 years post-ASCT, and two died at 7 and 11 months post-ASCT without evidence of lymphoma. Of 40 patients treated with conventional chemotherapy, with a median follow-up of 80 months, 33 have relapsed or progressed and 29 have died. Overall (OS) and progression-free (PFS) survival were superior in patients treated with ASCT-rituximab compared with those treated with conventional chemotherapy (PFS at 3 years, 89% versus 29%, P <0.00001; OS at 3 years, 88% versus 65%, P = 0.052).

CONCLUSIONS

This matched-pair analysis suggests that patients with advanced-stage MCL treated with ASCT-rituximab had statistically significantly better PFS and a trend toward better OS than patients treated with conventional chemotherapy. Longer follow-up will determine response duration and the true impact of this treatment strategy on PFS and OS.

Pharmacokinetic study of patients with follicular or mantle cell lymphoma treated with rituximab as 'in vivo purge' and consolidative immunotherapy following autologous stem cell transplantation

BACKGROUND

Little is known about the pharmacokinetics of rituximab in an autologous stem cell transplant (ASCT) setting.

PATIENTS AND METHODS

We evaluated serum rituximab levels in 26 patients with follicular or mantle cell lymphoma treated with a combination of ASCT and immunotherapy. Patients received nine infusions of rituximab (375 mg/m(2)): one dose as an 'in vivo purge' prior to stem cell collection, and two 4-week cycles at 8 and 24 weeks following ASCT. Pre- and post-infusion serum rituximab levels were measured during the purging dose, with doses 1 and 4 of both sets of maintenance rituximab cycles, and 12 weeks and 24 weeks following treatment.

RESULTS

Rituximab levels were detectable after the first infusion, and peaked at a mean concentration of 463.8 micro g/ml after the final dose. Levels remained detectable 24 weeks after completion of treatment. There was a trend toward higher rituximab levels in patients with follicular lymphoma. Serum concentrations achieved during the maintenance cycles were similar to levels observed in patients with measurable lymphoma treated during 'the pivotal trial'. No correlation was observed between serum rituximab levels achieved in the minimal disease state and the risk of later clinical relapse, nor with the ability to achieve a molecular remission following ASCT.

CONCLUSIONS

The finding that patients treated in minimal disease states and at the time of active disease both achieve similar final serum rituximab concentrations after four infusions suggests that the pharmacokinetics are complex, and may not necessarily correlate with disease burden. The precise factors influencing rituximab clearance in patients with lymphoma are unresolved, and this remains an area of active research.

Bcl-2 clearance: optimising outcomes in follicular non-Hodgkin's lymphoma

The long median survival time of patients with follicular non-Hodgkin's lymphoma (NHL), means that the efficacy of new treatments are difficult to assess in the short term. Bcl-2 is an inhibitor of apoptosis and overexpression of the bcl-2 gene in the blood or bone marrow is a feature in up to 85% of patients with follicular NHL. Levels of bcl-2(+) cells in the peripheral blood or bone marrow therefore are a useful measure of disease status in such patients and can be detected by polymerase chain reaction (PCR). Complete bcl-2 clearance from the bone marrow (molecular remission) following autologous stem cell transplant (ASCT) for follicular NHL is considered to be an important prognostic factor for disease-free survival. Tumour cell contamination of the stem cell grafts used in ASCT is commonly associated with relapse. This can be addressed by purging the stem cell harvest prior to transplantation. Various methods of in vitro purging after stem cell collection have been shown to reduce the level of contamination but yield is invariably reduced and grafts remain bcl-2 positive. However, in vivo purging with rituximab during the process of collection has been used to obtain bcl-2-negative stem cell harvests without compromising the yield. Rituximab is a monoclonal antibody licensed for treatment of relapsed and refractory low-grade or follicular NHL. Rituximab targets the CD20 antigen, which is found on cells of the B cell lineage. When used for in vivo purging it depletes the peripheral blood of CD20-positive cells and prevents contamination by lymphoma cells. Molecular remission, as measured by bone-marrow bcl-2 clearance, has been achieved in 7/7 patients with follicular NHL at 1 year after treatment with ASCT using rituximab as an 'in vivopurse', followed by rituximab maintenance. Early clinical outcomes are also encouraging.

A central role for IL-2 in fate determination of mature T cells--I: role in determining the Th1/Th2 profile in primary T cell cultures

IL-2 signaling appears to play a significant role in enabling the synthesis of T(h)2 cytokines in an in vitro system for studying primary T cell responses. When T cells from C57BL/6J or BALB/c strains of mice were activated in vitro and re-stimulated through their TCR complex 48 h later, CD4(+) T cells producing the T(h)2 cytokines IL-4 and IL-10 were found only when IL-2 was present. IL-2 also enhanced IFN-gamma synthesis in C57BL/6J cells but not in BALB/c cells. By up-regulating production of anti-inflammatory T(h)2 cytokines during a primary response, IL-2 may play a critical role in limiting T(h)1-mediated responses.

ALVAC-mediated gene transfer is efficient in lymphoid malignancies of T-and early B-cell origin, but not in tumors arising from mature B-cells

Natural attenuation of ALVAC virus in mammals makes it an attractive vector for cancer vaccine therapy of immunocompromised hosts, such as patients with lymphoid malignancies. However, the transduction efficiency of ALVAC constructs in lymphoid tumors has not yet been characterized. We studied a wide spectrum of human T- and B-cell leukemia and lymphomas and found significant heterogeneity of the ALVAC-mediated gene product expression in these tumors. While ALVAC-B7.1, ALVAC-B7.2, or ALVAC-luciferase vectors effectively expressed recombinant genes in malignancies arising from T- or early B-cell precursors, negative or low expression of ALVAC recombinant genes occurred in tumors arising from mature B-cells. We showed that ALVAC-encoded B7.1 or B7.2 was continuously expressed on the infected, and subsequently irradiated, leukemia cells, and only cells with ALVAC-mediated expression of costimulatory molecules (but not unmodified leukemia cells or those infected with the ALVAC-parental vector) induced significant proliferation and IFN-gamma production by alloreactive T-cells. These data provide the rationale for clinical studies using the ALVAC vector system for gene transfer into lymphoid tumors of T- and early B-cell origin to render them more immunogenic, while alternative strategies should be considered for immunotherapy of mature B-cell malignancies.

Prolonged molecular and clinical remission after treatment of a patient with follicular lymphoma with rituximab

Rituximab is a chimeric anti-CD20 monoclonal antibody that has approval for single agent therapy in the treatment of relapsed/refractory low grade or follicular non-Hodgkin's Lymphoma. In published phase II trials, molecular remissions of PCR detectable t(14;18) disease in the peripheral blood have been reported in up to 62% of patients by three months. We report a case of a patient who achieved prolonged clinical and molecular remission following a single four week course of Rituximab that has exceeded any previous remission achieved with chemo-radiotherapy. The implications of molecular remission as a surrogate of clinical remission and molecular relapse as a harbinger of clinical relapse are reviewed and discussed.

Characterization of graft-versus-host disease in SCID mice and prevention by physicochemical stressors

BACKGROUND

Graft versus host disease (GVHD) prevents potentially curative allogeneic stem cell transplantation from being offered to cancer patients who lack a suitably matched donor. New methods to prevent GVHD are required to allow successful transplants across major histocompatibility complex barriers.

METHODS

A model of GVHD in C.B-17 SCID mice was developed to allow the study of allo-activated donor T cells without confounding effects of host lymphocytes. The abilities of cyclosporin-A, anticytokine antibodies, and oxidative stress to prevent GVHD in this model was studied.

RESULTS

T cells from major histocompatibility-mismatched donor mice caused severe GVHD in sublethally irradiated SCID hosts that could be ameliorated by coadministration of donor bone marrow but not by cyclosporine-A or anticytokine antibodies. In contrast, three-log more T cells could be injected without clinical consequences if they had been pretreated with a combination of heat, ultraviolet light, and oxygenation. The effect was not the trivial result of donor T cell destruction because T cell reconstitution, although delayed, recovered to normal levels within 2 weeks. Protection from GVHD required oxygenation and was associated with normalization of the CD4/CD8 donor T cell ratio, recovery of host hematopoiesis, and decreased inflammatory cytokine production.

CONCLUSION

Pretreatment of donor T cells with a combination of physicochemical stressors effectively prevents GVHD caused by major major histocompatibility disparities and may facilitate the safe transplantation of patients without HLA-identical donors.

Epidermal growth factor induces cell cycle arrest and apoptosis of squamous carcinoma cells through reduction of cell adhesion

Most squamous epithelial cells are strictly anchorage-dependent cell types. We observed that epidermal growth factor (EGF) promoted the growth of A431 squamous carcinoma cells in suspension cultures but suppressed cell growth and induced apoptosis in monolayer cultures, suggesting that loss of adhesion is responsible for the effects observed in monolayer culture, before cell death. Consistent with this finding, we demonstrated that EGF reduced cell attachment, cell-cell interaction, and cell spreading. Treatment with EGF increased cell adhesion-regulated expression of p21 but suppressed expressions of cyclin A, D1, cdk2, and retinoblastoma protein (pRb), leading to cell cycle arrest and adhesion-regulated programmed cell death. To test directly whether promoting cell adhesion could reduce the effects of EGF, we grew cultures on plates coated with type II collagen. On these plates, cell adhesion was enhanced and EGF treatment had little effect on cell adhesion and apoptosis when cells were attached to the collagen. The collagen effects were dose dependent, and cell cycle and cell cycle-associated proteins were altered accordingly. Finally, when cultures were plated on bacterial Petri dishes, which completely disrupted cell attachment to substratum, the level of apoptosis was greatly higher and cell cycle was arrested as compared with monolayer cultures. Taken together, our results strongly suggest that the EGF-induced cell cycle arrest and apoptosis in monolayer cultures was the result of a decline in cell adhesion.

Immunogenicity of whole-cell tumor preparations infected with the ALVAC viral vector

The immunogenicity of recombinant canarypox (ALVAC) viral vectors within murine whole-cell tumor vaccines was evaluated using the T cell thymic lymphoma STF10 and the B16 melanoma. Tumor cells were modified with the recombinant ALVAC vectors and injected into syngeneic mice. Control mice receiving cells alone all developed tumors, while mice injected with tumor variants bearing parental and recombinant vectors either completely rejected their tumors, or exhibited a significant delay in tumor formation. Rechallenge of mice receiving STF10-variant vaccines yielded a protective effect against parental tumor cells only when a modified regimen incorporating two vaccinations was utilized. Notably, the parental ALVAC virus was equivalent to all other recombinant ALVAC viruses in conferring antitumor immunity when using a prime-and-boost protocol. Tumorigenicity experiments in nude mice revealed that the effector mechanism mediating rejection of tumor cells bearing ALVAC vectors is multifactorial, in that the immunogenicity of STF10/ALVAC vaccines is reduced, but not completely abolished in these mice. Finally, in vitro experiments revealed that cytotoxic T cells specific for parental STF10 cells could be generated as a result of in vivo immunization with STF10/ALVAC vaccines.

Stem cell function and engraftment is not affected by "in vivo purging" with rituximab for autologous stem cell treatment for patients with low-grade non-Hodgkin's lymphoma

The chimeric anti-CD20 monoclonal antibody rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA, and Genentech, Inc, San Francisco, CA) has recently been approved by the US Food and Drug Administration as single-agent treatment of relapsed/refractory low-grade or follicular non-Hodgkin's lymphoma. Initial results from the pivotal clinical trial revealed that response rates to rituximab were higher in patients who previously had high-dose therapy and autologous stem cell transplantation. We have initiated a clinical trial that combines the use of rituximab with high-dose chemotherapy followed by autologous stem cell transplantation for patients with chemosensitive relapsed follicular small cleaved or mantle cell lymphoma. A unique feature of this study is that in addition to eight maintenance infusions of rituximab after autologous stem cell transplantation, patients also received rituximab 375 mg/m2 2 days before a granulocyte colony-stimulating factor-mobilized stem cell collection as "in vivo purge." We report on preliminary results demonstrating the safety and efficacy of the in vivo purge on 10 patients undergoing stem cell mobilization, nine of whom have already undergone transplantation. The peripheral blood CD34+ counts were 14.92 and 20 x 10(6)/L on day 4 and day 5, respectively, of the stem cell mobilization with granulocyte colony-stimulating factor. This compares with 11.7 and 11.8 x 10(6)/L, respectively, for the control population. The median CD34 stem cell yield in the graft collection was 3.7 x 10(6)/kg in patients receiving rituximab in vivo purge compared with 3.1 x 10(6)/kg in the control population. The target stem cell collection was successfully collected in six of 10 patients in a 1-day single large-volume leukapheresis collection, while two patients required 2 days and the last two patients required 3 days. Functional assays revealed the stem cell colony-forming unit-granulocyte monocyte and burst-forming unit-erythrocyte to be 55 and 44 colonies per plate, respectively, for the patients receiving the in vivo rituximab purge. This compares favorably with 37 and 38.5 colonies per plate, respectively, for the control population. Neutrophil engraftment took a median of 11 days for both cohorts; platelet independence was achieved in 8 days compared with 10 days for the control population. The median number of platelet transfusions was two for patients receiving rituximab and 2.5 for the control group. Assessment of serum cytokines immediately before the rituximab infusion during the stem cell mobilization and immediately after revealed a twofold to sevenfold increase in interleukin-1beta, tumor necrosis factor-alpha, and interleukin-6. The polymerase chain reaction analysis for minimal residual disease in stem cell collections and in peripheral blood and bone marrow samples of these patients will help to determine the efficacy of rituximab in vivo purge on disease progression.

Long-term persistence of IL-2-unresponsive allogeneic T cells in sublethally irradiated SCID mice

Donor T cells that are activated by host alloantigens initiate graft versus host disease (GVHD) but their long-term fate is poorly understood. The behavior of alloreactive donor T cells was studied in sublethally irradiated SCID mice. Intravenous injection of 10(6) allogeneic lymphocytes caused a severe form of GVHD, characterized by host hematopoietic atrophy. Fifty-fold fewer donor cells did not induce disease and were not simply rejected by radioresistant host mechanisms. Instead, low numbers of allogeneic T cells expanded 20- to 50-fold and remained for >1 year without causing evidence of GVHD. Persistent non-cycling donor cells with an activated phenotype were mainly found in the spleen. Tolerance was inferred by the recovery of host hematopoiesis, despite the presence of donor allogeneic T cells, and the inability of long-term persisting donor T cells to mediate cellular cytotoxicity or proliferate in response to exogenous IL-2 or antigenic stimulation in vitro. The TCR density of long-term persisting donor T cells was down-regulated. These findings suggest that the development of GVHD depends on the magnitude of the initial anti-host response. Subsequently donor cells differentiate, over several months, into a senescent-like state. This behavior questions the rationale for current treatment approaches to GVHD and is of relevance to any clinical situation where chronic T cell activation takes place in the absence of thymic development.

Phosphorylation of p53 protein in response to ionizing radiation occurs at multiple sites in both normal and DNA-PK deficient cells

The tumour suppressor gene product, p53, is involved in mediating cellular responses to DNA damage including growth arrest and/or apoptosis. The mechanism by which p53 protein senses the presence of damaged DNA is not understood. The possibility that p53 may be post-translationally modified by enzymes that are activated in response to DNA damage including DNA-dependent protein kinase (DNA-PK), poly(ADP-ribose) polymerase and stress activated protein kinase has received considerable attention. Recent studies have indicated that DNA-PK is not required for the transactivation or apoptosis-promoting activities of p53 protein. However, the possibility that other functions of p53 may be dependent on phosphorylation by DNA-PK has not been explored. Here we describe a series of experiments that compares the expression, function and phosphorylation status of p53 protein in normal and DNA-PK-deficient scid cells. While several novel p53 phosphoforms are generated in response to DNA damage in normal cells, the same phosphoforms are observed in scid cells.

A role for perforin in activation-induced T cell death in vivo: increased expansion of allogeneic perforin-deficient T cells in SCID mice

Despite defective granule exocytosis, T cells from mice whose perforin gene was ablated by homologous recombination (pko mice) caused a similar degree of graft-vs-host disease as normal T cells after injection into sublethally irradiated C.B-17 SCID mice. Moreover host spleens contained significantly greater numbers of T cells from pko mice than from wild-type mice following their i.v. injection. This increase could not be explained by persistence of host APCs that were not cleared by defective donor cytotoxic effector cells. The absence of functional perforin-dependent suppressor cells or an altered cytokine profile of donor T cells could also not account for the behavior of pko cells. Spontaneous and Fas-mediated apoptosis of in vivo activated donor T cells were independent of donor origin. However, pko T blasts exhibited less growth inhibition and cell death after reactivation in vitro. The results are compatible with a model of a defective activation-induced cell death (AICD) pathway, controlled by perforin, accounting for the increased expansion of alloreactive pko T cells.

Exploring the barriers to cervical screening in an urban Canadian setting

Cervical cancer is potentially one of the most preventable cancers. The benefits of cervical screening come to those who are actually screened. Despite the known value of cervical screening, a significant number of women do not avail themselves of the procedure. This study examined the barriers to cervical screening in an urban Canadian setting. Focus group methodology was used to explore the perspectives of socioeconomically disadvantaged women regarding their access to health care. The sessions were tape-recorded, and subsequent content analysis revealed four broad themes: being able to talk with doctors is important; being treated as a person is important; finding answers to many questions about cancer is important; and having a Pap test is uncomfortable. Implications for practice and program design were highlighted.

Clinical and economic analysis of allogeneic peripheral blood progenitor cell transplants: a Canadian perspective

Allogeneic peripheral blood progenitor cell (PBPC) transplants are an alternative to BMT, although G-CSF mobilization dose, timing of pheresis and risk of GVHD are not well defined. We compared harvest characteristics, donor and recipient outcomes and costs of two PBPC transplant strategies with historical controls who received BMT. Twenty donors mobilized with four daily s.c. G-CSF doses (5 microg/kg/day) (group 1) and 20 mobilized with 10 microg/kg/day G-CSF (group 2) were compared with 20 BM controls (group 3). G-CSF and phereses were well tolerated. Four of 40 PBPC donors required femoral catheter placement. At least 2.5 x 10(6) CD34+/kg recipient weight were collected with two phereses in 19/20 donors (group 1) and 18/20 donors (group 2). Time to neutrophil (18 vs 20 vs 22 days, P = 0.02) and platelet (21 vs 24 vs 27 days, P = 0.005) engraftment was shorter in the PBPC groups (group 2 vs group 1 vs group 3) but secondary engraftment outcomes were not different. The incidence of grade 2-4 aGVHD was higher in the low-dose G-CSF group (group 1) but there was no difference in cGVHD, 100-day or 1-year survival. The mean PBPC transplant cost (group 1) at first hospital discharge was less than BM (group 3) ($34,643 vs $37,354) but the mean overall cost for both groups was similar at 100 days ($46,334 vs $46,083). Allogeneic PBPC transplant with short course, low-dose G-CSF mobilization is safe, feasible and cost equivalent to allogeneic BMT.

Acute intestinal graft-versus-host disease in a syngeneic bone marrow transplant recipient

BACKGROUND

We report a case of intestinal graft-versus-host disease (GVHD) in a syngeneic bone marrow transplant patient.

METHODS

Several days after receiving a bone marrow transplant from his identical twin for treatment of non-Hodgkin's lymphoma, a 47-year-old man developed a skin rash and diarrhea.

RESULTS

A colonic biopsy on day +15 revealed characteristic changes of acute intestinal GVHD. Molecular studies (microsatellite DNA and HLA sequence-specific primer polymerase chain reaction analyses) confirmed the genotypic identity of donor and host and the improbability of transfusion-associated GVHD.

CONCLUSION

This case illustrates that pathological evidence of GVHD does not absolutely require the presence of genetic differences between host and donor and questions existing concepts about the nature of cyclosporine-induced GVHD.

Geographical considerations regarding donor leukocyte infusions for the treatment of relapsed hematological malignancies

Infusion of donor leukocytes, to provoke graft-versus-host disease and a graft versus leukemia effect, is remarkably effective in the treatment of some forms of relapsed hematological malignancies after transplantation of allogeneic stem cells. In this commentary I argue that the variable susceptibility of tumor cells to donor leukocyte infusions can be predicted on the basis of their localization to the T cell areas of secondary lymphoid organs and the amount of donor chimerism in the patient. This conclusion leads to the hypothesis that it may be possible to modulate graft-versus-leukemia reactions in a controlled and predictable fashion.

A role for perforin in activation-induced cell death

The granule exocytosis pathway of T cell cytotoxicity is absent in mice whose perforin gene has been ablated by targeted mutagenesis. The ability of activated naive T cells to undergo apoptosis in vitro following reaggregation of the TCR complex with anti-TCR mAbs via a Fas-independent pathway was found to be defective in the absence of perforin. Protection from death was most marked in CD8+ T cells. In wild-type cells, perforin was expressed at the same time that apoptosis occurred, and blockade of perforin expression by either incubation with perforin antisense oligonucleotides or with anti-IL-2 Abs resulted in increased viability of activated T cells. The role of perforin was not via perforin-dependent fratricidal killing. The results suggest a model in which perforin acts internally to cause a form of activation-induced T cell death distinct from that caused by members of the TNFR superfamily.

Interleukin-2 reverses the defect in activation-induced apoptosis in T cells from autoimmune lpr mice

Activated T cells from MRLlpr/lpr (lpr) mice have been shown to be resistant to TCR-induced apoptosis (activation-induced cell death) in vitro. We have found that this resistance is related to a defect in IL-2R alpha (CD25) expression and IL-2 signaling. Following primary activation, splenic T cells from 8-week old lpr mice failed to undergo apoptosis after the TCR was religated upon reculture with plate-bound anti-CD3 mAb. These cells had markedly reduced levels of IL-2 secretion and CD25 expression during primary activation in vitro; however, the cells still progressed through the cell cycle and were capable of cell division following TCR religation. Addition of exogenous IL-2 during the primary activation of 8-week-old lpr T cells overcame the defect in CD25 expression. Strikingly, these cells also became sensitive to apoptosis induction and died when the TCR was religated with anti-CD3 mAb. Viable cell recovery of both the lpr CD4+ and CD8+ subsets, as well as the CD4-CD8- subsets, was dramatically reduced under these conditions. Further investigation also revealed that the defect in activation-induced apoptosis in T cells from lpr mice was age-related. Activated T cells from young lpr mice (5 weeks old) underwent apoptosis in response to TCR ligation; these cells also expressed normal levels of CD25 following primary activation. However, as the mice aged from 5 to 8 weeks, susceptibility to TCR-mediated apoptosis in vitro was progressively lost together with the ability to express CD25. Our results suggest that before the onset of severe lymphoaccumulation, activated T cells from young lpr mice possess the capability to undergo TCR-induced apoptosis despite defective fas expression; IL-2 participates in sensitizing the cells to this death pathway. In older mice, this pathway breaks down and, together with the lack of fas-induced apoptosis, may account for the onset of severe lymphoaccumulation and autoimmunity.

Abnormal thyroid stimulating hormone (TSH) levels in adults following allogeneic bone marrow transplants

Thyroid function abnormalities in 270 adult patients post-BMT are described. Various conditioning regimens were used and the effects of three TBI and one chemotherapy only based regimens are compared. The overall incidence of elevated TSH is 8.9; 3.8, 7.2 and 16.7% in those patients who received 300, 500 and 1200 cGy respectively and 11.7% in those who received BuCy conditioning. Three cases (1.1%) of clinial hypothyroidism were observed. Compensated hypothyroidism defined as an elevated TSH in the presence of normal T3, T4 levels and transient in some cases, was the most common finding. All but four cases occurred in the first 2 years after BMT. In the remaining four, three occurred in patients with chronic GVHD. The results reported here show a lower prevalence than observed in most other reviews, particularly for children. A trend was observed with increasing radiation doses. The results are not significantly different from those we observed in the BuCy regimen.

Towards an inclusive cervical cancer screening strategy: approaches for reaching socioeconomically disadvantaged women

Barriers to prevention and early detection of cancer among the socioeconomically disadvantaged are important areas for public health focus. A community coalition was established in North York, Ontario, to identify a suitable primary prevention initiative, cervical screening among young women of lower economic status. Two pilot communities were selected for the project. Community members, key informants and service providers participated in a series of individual and focus group meetings to identify barriers that impede cervical screening. The benefits and challenges of such a project will be importance to practitioners eager to work collaboratively on primary prevention initiatives. This article will be of interest to nurses wanting to foster a community coalition approach to program design, planning, implementation and evaluation. It will also assist nurses with utilizing needs-based assessment in their work. Although the findings relate to a population of women in a large urban centre, the results will be useful for nurses and other health professionals planning to engage in work related to cervical screening.

Antigen-presenting cells for naive transgenic gamma delta T cells. Potent activation by activated alpha beta T cells

The function of gamma delta T cells, particularly the minor population of circulating gamma delta T cells, remains unclear. To study these lymphoid gamma delta T cells, a transgenic SCID mouse containing the KN6 gamma delta TCR whose ligand is the TL gene product, T22b, was created. KN6-SCID mice contain a monoclonal population of naive KN6+ gamma delta T cells. Using these mice, we have studied the APC required for activation of KN6+ gamma delta T cells in vitro and in vivo. Analysis of an in vitro mixed lymphocyte response identified a hierarchy of potency for stimulation: dendritic cells = T cell blasts > B cell blasts > B cells > resting T cells. In contrast, in vivo, only alpha beta T cells fully activated KN6+ gamma delta T cells as measured by an increase in the number of splenic KN6+ cells, the development of blast morphology, and the development of proliferative anergy in the responding KN6+ cells. The strong stimulatory properties of C57BL/6J T cells appeared to depend on their having been activated by KN6-SCID alloantigens. T cells from (C57BL/6J x BALB/c)F1 mice, which are tolerant of KN6-SCID alloantigens, could not fully activate KN6+ cells. However, the F1 T cells could activate KN6+ cells if they were activated in vivo by the mitogen, staphylococcal enterotoxin B. A mixture of third party activated T cells plus T22b+ non-T cells only partially activated KN6+ cells, implying that activated T22b+ T cells are acting directly as stimulatory cells. Although the Ags recognized by gamma delta T cells are generally unknown, Ag presentation by activated alpha beta T cells may be an important method of activation.

Antigen-presenting cells for naive transgenic gamma delta T cells. Potent activation by activated alpha beta T cells

The function of gamma delta T cells, particularly the minor population of circulating gamma delta T cells, remains unclear. To study these lymphoid gamma delta T cells, a transgenic SCID mouse containing the KN6 gamma delta TCR whose ligand is the TL gene product, T22b, was created. KN6-SCID mice contain a monoclonal population of naive KN6+ gamma delta T cells. Using these mice, we have studied the APC required for activation of KN6+ gamma delta T cells in vitro and in vivo. Analysis of an in vitro mixed lymphocyte response identified a hierarchy of potency for stimulation: dendritic cells = T cell blasts &gt; B cell blasts &gt; B cells &gt; resting T cells. In contrast, in vivo, only alpha beta T cells fully activated KN6+ gamma delta T cells as measured by an increase in the number of splenic KN6+ cells, the development of blast morphology, and the development of proliferative anergy in the responding KN6+ cells. The strong stimulatory properties of C57BL/6J T cells appeared to depend on their having been activated by KN6-SCID alloantigens. T cells from (C57BL/6J x BALB/c)F1 mice, which are tolerant of KN6-SCID alloantigens, could not fully activate KN6+ cells. However, the F1 T cells could activate KN6+ cells if they were activated in vivo by the mitogen, staphylococcal enterotoxin B. A mixture of third party activated T cells plus T22b+ non-T cells only partially activated KN6+ cells, implying that activated T22b+ T cells are acting directly as stimulatory cells. Although the Ags recognized by gamma delta T cells are generally unknown, Ag presentation by activated alpha beta T cells may be an important method of activation.

Gamma delta T cells differentiate into a functional but nonproliferative state during a normal immune response

To obtain a homogeneous population of gamma delta T cells to investigate their role in an immune response, we have made a scid mouse doubly transgenic for rearranged gamma and delta genes. The receptor (KN6) encoded by these genes is specific for the major histocompatibility complex class I protein encoded by the T22b gene. This mouse contains high levels of transgenic gamma delta T cells in the spleen and thymus and no other T lymphocytes. Immunization of these KN6-scid (H-2d, TLd) mice with 10(7) C57BL/6J (abbreviated B6) (H-2b, TLb) spleen cells resulted in proliferation and activation of the gamma delta T cells in spleen and clearing of the allogeneic B6 lymphocytes. Subsequently, the majority of activated cells died by apoptosis and the remaining cells were anergic with regard to proliferation. The anergic cells did not respond to restimulation by B6 spleen cells in vitro or in vivo, and addition of exogenous interleukin 2 failed to restore the response to B6 cells. Cytotoxicity, a property of KN6+ cells during a primary stimulation, was no longer detectable in the proliferatively anergic cells. However, B6 spleen cells injected into mice primed 12 days previously were cleared with a much greater efficiency than on primary challenge and in an antigen-specific manner. We conclude that after exposure to antigen, gamma delta T cells rapidly proliferate into blasts; the majority of the blasts rapidly die, with the nonproliferating cells remaining in a highly active state for several weeks and able to initiate elimination of lymphoid cells bearing the TLb epitope.

Hypersensitivity to natural latex

Rubber hypersensitivity is well described but usually as a contact dermatitis caused by chemicals added during the process of making natural latex or synthetic rubber. IgE-mediated reactions, mainly contact urticaria, have rarely been reported in Europe. We report a case of immediate hypersensitivity to latex. A 34-year-old female operating room nurse developed hand eczema to natural latex. On two occasions, while she was gloving for surgery, she had the following reactions: flushing, tachycardia, urticaria, angioedema, wheezing, and light-headedness. Prick and patch testing to thiuram mix, mercaptobenzothiazole, phenylenediamine mix, and carbamate mix (common rubber additives) were negative. Prick tests to natural latex elicited a 4+ reaction associated with immediate flushing, tachycardia, urticaria, and light-headedness. Five control subjects did not react. IgE antibodies to latex by RAST demonstrated 17.7% binding (control, 4%). This case demonstrates that natural latex can cause IgE-mediated symptoms. The route of exposure was cutaneous absorption of relevant latex allergens. As the use of latex rubber products continues to escalate, more cases are likely to occur.