Structural analysis of cancer-relevant TCR-CD3 and peptide-MHC complexes by cryoEM

The recognition of antigenic peptide-MHC (pMHC) molecules by T-cell receptors (TCR) initiates the T-cell mediated immune response. Structural characterization is key for understanding the specificity of TCR-pMHC interactions and informing the development of therapeutics. Despite the rapid rise of single particle cryoelectron microscopy (cryoEM), x-ray crystallography has remained the preferred method for structure determination of TCR-pMHC complexes. Here, we report cryoEM structures of two distinct full-length α/β TCR-CD3 complexes bound to their pMHC ligand, the cancer-testis antigen HLA-A2/MAGEA4 (230-239). We also determined cryoEM structures of pMHCs containing MAGEA4 (230-239) peptide and the closely related MAGEA8 (232-241) peptide in the absence of TCR, which provided a structural explanation for the MAGEA4 preference displayed by the TCRs. These findings provide insights into the TCR recognition of a clinically relevant cancer antigen and demonstrate the utility of cryoEM for high-resolution structural analysis of TCR-pMHC interactions.

Immuno-PET monitoring of lymphocytes using the CD8-specific antibody REGN5054

Assessment of immune-cell subsets within the tumor immune microenvironment is a powerful approach to better understand cancer immunotherapy responses. However, the use of biopsies to assess the tumor immune microenvironment poses challenges, including the potential for sampling error, restricted sampling over time and inaccessibility of some tissues/organs, as well as the fact that single biopsy analyses do not reflect discordance across multiple intrapatient tumor lesions. Immuno-PET presents a promising translational imaging approach to address the limitations and assess changes in the tumor microenvironment. We have developed 89Zr-DFO-REGN5054, a fully human CD8A-specific antibody conjugate, to assess CD8+ tumor-infiltrating lymphocytes (TILs) pre- and post-therapy. We used multiple assays, including in vitro T-cell activation, proliferation, and cytokine production, and in vivo viral clearance and CD8 receptor occupancy, to demonstrate that REGN5054 has minimal impact on T-cell activity. Preclinical immuno-PET studies demonstrated that 89Zr-DFO-REGN5054 specifically detected CD8+ T cells in lymphoid tissues of CD8-genetically humanized immunocompetent mice (VelociT mice) and discerned therapy-induced changes in CD8+ TILs in two models of response to a CD20xCD3 T-cell activating bispecific antibody (REGN1979, odronextamab). Toxicology studies in cynomolgus monkeys showed no overt toxicity, and immuno-PET imaging in cynomolgus monkeys demonstrated dose-dependent clearance and specific targeting to lymphoid tissues. This work supports the clinical investigation of 89Zr-DFO-REGN5054 to monitor T-cell responses in patients undergoing cancer immunotherapy.

Tumor-targeted CD28 bispecific antibodies enhance the antitumor efficacy of PD-1 immunotherapy

Monoclonal antibodies that block the programmed cell death 1 (PD-1) checkpoint have revolutionized cancer immunotherapy. However, many major tumor types remain unresponsive to anti-PD-1 therapy, and even among responsive tumor types, most of the patients do not develop durable antitumor immunity. It has been shown that bispecific antibodies activate T cells by cross-linking the TCR/CD3 complex with a tumor-specific antigen (TSA). The class of TSAxCD3 bispecific antibodies have generated exciting results in early clinical trials. We have recently described another class of "costimulatory bispecifics" that cross-link a TSA to CD28 (TSAxCD28) and cooperate with TSAxCD3 bispecifics. Here, we demonstrate that these TSAxCD28 bispecifics (one specific for prostate cancer and the other for epithelial tumors) can also synergize with the broader anti-PD-1 approach and endow responsiveness-as well as long-term immune memory-against tumors that otherwise do not respond to anti-PD-1 alone. Unlike CD28 superagonists, which broadly activate T cells and induce cytokine storm, TSAxCD28 bispecifics display little or no toxicity when used alone or in combination with a PD-1 blocker in genetically humanized immunocompetent mouse models or in primates and thus may provide a well-tolerated and "off the shelf" combination approach with PD-1 immunotherapy that can markedly enhance antitumor efficacy.

A class of costimulatory CD28-bispecific antibodies that enhance the antitumor activity of CD3-bispecific antibodies

T cell activation is initiated upon binding of the T cell receptor (TCR)/CD3 complex to peptide-major histocompatibility complexes ("signal 1"); activation is enhanced by engagement of a second "costimulatory" receptor, such as the CD28 receptor on T cells binding to its cognate ligand(s) on the target cell ("signal 2"). CD3-based bispecific antibodies act by replacing conventional signal 1, linking T cells to tumor cells by binding a tumor-specific antigen (TSA) with one arm of the bispecific and bridging to TCR/CD3 with the other. Although some of these so-called TSAxCD3 bispecifics have demonstrated promising antitumor efficacy in patients with cancer, their activity remains to be optimized. Here, we introduce a class of bispecific antibodies that mimic signal 2 by bridging TSA to the costimulatory CD28 receptor on T cells. We term these TSAxCD28 bispecifics and describe two such bispecific antibodies: one specific for ovarian and the other for prostate cancer antigens. Unlike CD28 superagonists, which broadly activate T cells and resulted in profound toxicity in early clinical trials, these TSAxCD28 bispecifics show limited activity and no toxicity when used alone in genetically humanized immunocompetent mouse models or in primates. However, when combined with TSAxCD3 bispecifics, they enhance the artificial synapse between a T cell and its target cell, potentiate T cell activation, and markedly improve antitumor activity of CD3 bispecifics in a variety of xenogeneic and syngeneic tumor models. Combining this class of CD28-costimulatory bispecific antibodies with the emerging class of TSAxCD3 bispecifics may provide well-tolerated, off-the-shelf antibody therapies with robust antitumor efficacy.

Preclinical PET imaging with the novel human antibody 89Zr-DFO-REGN3504 sensitively detects PD-L1 expression in tumors and normal tissues

Background

Programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) blocking antibodies including cemiplimab have generated profound clinical activity across diverse cancer types. Tumorous PD-L1 expression, as assessed by immunohistochemistry (IHC), is an accepted predictive marker of response to therapy in some cancers. However, expression is often dynamic and heterogeneous, and therefore not reliably captured by IHC from tumor biopsies or archival samples. Thus, there is significant need for accurate whole-body quantification of PD-L1 levels.

Methods

We radiolabeled the novel human anti-PD-L1 antibody REGN3504 with zirconium-89 (⁸⁹Zr) using the chelator p-SCN-Bn-Deferoxamine to enable non-invasive immuno-positron emission tomography (immuno-PET) of PD-L1 expression. PET imaging assessed the localization of ⁸⁹Zr-REGN3504 to multiple human tumor xenografts. Mice genetically humanized for PD-1 and PD-L1 were used to assess the biodistribution of ⁸⁹Zr-REGN3504 to normal tissues and the estimated human radiation dosimetry of ⁸⁹Zr-REGN3504 was also determined. Pharmacokinetics of REGN3504 was assessed in monkeys.

Results

Clear localization of ⁸⁹Zr-REGN3504 to human tumor xenografts was observed via PET imaging and ex vivo biodistribution studies demonstrated high (fourfold to sixfold) tumor:blood ratios. ⁸⁹Zr-REGN3504 specifically localized to spleen and lymph nodes in the PD-1/PD-L1 humanized mice. ⁸⁹Zr-REGN3504 immuno-PET accurately detected a significant reduction in splenic PD-L1 positive cells following systemic treatment with clodronate liposomes. Radiation dosimetry suggested absorbed doses would be within guidelines for other ⁸⁹Zr radiolabeled, clinically used antibodies. Pharmacokinetics of REGN3504 was linear.

Conclusion

This work supports the clinical translation of ⁸⁹Zr-REGN3504 immuno-PET for the assessment of PD-L1 expression. Future clinical studies will aim to investigate the utility of ⁸⁹Zr-REGN3504 immuno-PET for predicting and monitoring response to anti-PD-1 therapy.

A Biparatopic Antibody That Modulates MET Trafficking Exhibits Enhanced Efficacy Compared with Parental Antibodies in MET-Driven Tumor Models

PURPOSE

Recent clinical data demonstrate that tumors harboring MET genetic alterations (exon 14 skip mutations and/or gene amplification) respond to small-molecule tyrosine kinase inhibitors, validating MET as a therapeutic target. Although antibody-mediated blockade of the MET pathway has not been successful in the clinic, the failures are likely the result of inadequate patient selection strategies as well as suboptimal antibody design. Thus, our goal was to generate a novel MET blocking antibody with enhanced efficacy.

EXPERIMENTAL DESIGN

Here, we describe the activity of a biparatopic MET×MET antibody that recognizes two distinct epitopes in the MET Sema domain. We use a combination of in vitro assays and tumor models to characterize the effect of our antibody on MET signaling, MET intracellular trafficking, and the growth of MET-dependent cells/tumors.

RESULTS

In MET-driven tumor models, our biparatopic antibody exhibits significantly better activity than either of the parental antibodies or the mixture of the two parental antibodies and outperforms several clinical-stage MET antibodies. Mechanistically, the biparatopic antibody inhibits MET recycling, thereby promoting lysosomal trafficking and degradation of MET. In contrast to the parental antibodies, the biparatopic antibody fails to activate MET-dependent biological responses, consistent with the observation that it recycles inefficiently and induces very transient downstream signaling.

CONCLUSIONS

Our results provide strong support for the notion that biparatopic antibodies are a promising therapeutic modality, potentially having greater efficacy than that predicted from the properties of the parental antibodies.

Development of Clinical-Stage Human Monoclonal Antibodies That Treat Advanced Ebola Virus Disease in Nonhuman Primates

Background

For most classes of drugs, rapid development of therapeutics to treat emerging infections is challenged by the timelines needed to identify compounds with the desired efficacy, safety, and pharmacokinetic profiles. Fully human monoclonal antibodies (mAbs) provide an attractive method to overcome many of these hurdles to rapidly produce therapeutics for emerging diseases.

Methods

In this study, we deployed a platform to generate, test, and develop fully human antibodies to Zaire ebolavirus. We obtained specific anti-Ebola virus (EBOV) antibodies by immunizing VelocImmune mice that use human immunoglobulin variable regions in their humoral responses.

Results

Of the antibody clones isolated, 3 were selected as best at neutralizing EBOV and triggering FcγRIIIa. Binding studies and negative-stain electron microscopy revealed that the 3 selected antibodies bind to non-overlapping epitopes, including a potentially new protective epitope not targeted by other antibody-based treatments. When combined, a single dose of a cocktail of the 3 antibodies protected nonhuman primates (NHPs) from EBOV disease even after disease symptoms were apparent.

Conclusions

This antibody cocktail provides complementary mechanisms of actions, incorporates novel specificities, and demonstrates high-level postexposure protection from lethal EBOV disease in NHPs. It is now undergoing testing in normal healthy volunteers in preparation for potential use in future Ebola epidemics.

Palliative care for cancer patients near end of life in acute-care hospitals across Canada: a look at the inpatient palliative care code

Hospitals play an important role in the care of patients with advanced cancer: nearly half of all cancer deaths occur in acute-care settings. The need for increasing access to palliative care and related support services for patients with cancer in acute-care hospitals is therefore growing. Here, we examine how often and how early in their illness patients with cancer might be receiving palliative care services in the 2 years before their death in an acute-care hospital in Canada. The palliative care code from inpatient administrative databases was used as a proxy for receiving, or being referred for, palliative care. Currently, the palliative care code is the only data element routinely collected from patient charts that allows for the tracking of palliative care activity at a pan-Canadian level. Our findings suggest that most patients with cancer who die in an acute-care hospital receive a palliative designation; however, many of those patients are identified as palliative only in their final admission before death. Of the patients who received a palliative designation before their final admission, nearly half were identified as palliative less than 2 months before death. Findings signal that delivery of services within and between jurisdictions is not consistent, that the palliative care needs of some patients are being missed by physicians, and that palliative care is still largely seen as end-of-life care and is not recognized as an integral component of cancer care. Measuring the provision of system-wide palliative care remains a challenge because comprehensive national data about palliative care are not currently reported from all sectors. To advance measurement and reporting of palliative care in Canada, attention should be focused on collecting comparable data from regional and provincial palliative care programs that individually capture data about palliative care delivery in all health care sectors.

Acute-Care Hospital Use Patterns Near End-of-Life for Cancer Patients Who Die in Hospital in Canada

Background: Acute-care hospitals have a role in managing the needs of people with cancer when they are at the end-of-life; however, overutilization of hospital care at the end-of-life results in poorer quality of life and can worsen the patient's experience. Early integration of comprehensive palliative care can greatly reduce unplanned visits to the emergency department, reduce avoidable admissions to hospital, shorten hospital stays, and increase the number of home deaths as well as improve the quality of life of patients with advanced cancer. Aim: To describe the current landscape of acute-care hospital utilization near the end-of-life across Canada and indirectly examine access to palliative care in cancer patients who die in hospital. Methods: Data were obtained from the Canadian Institute for Health Information. The analysis was restricted to adults aged 18+ who died in an acute care hospital in 2014/15 and 2015/16 for nine provinces and three territories. The Discharge Abstract Database was used to extract acute-care cancer death abstracts. Data on intensive care unit (ICU) admissions includes only facilities that report ICU data. Results: Acute care utilization at end-of-life remains commonplace. In Canada (excluding Québec), 43% (48,987) of deaths from cancer occurred in acute-care hospitals, with 70% admitted through the emergency department (ED). In the last six months of life, cancer patients dying in hospital had a median cumulative length of stay ranging from 17 to 25 days, depending on the province. Between 18.1% and 32.8% of patients experienced two or more admissions to the hospital in the last month of life. The proportion of cancer patients admitted to the ICU in the last 14 days of life ranged from 6.4% to 15.1%. Patient demographics (age, sex, place of residence) and clinical factors (cancer type) were often predictors of hospital utilization at end-of-life and likely point to inequities in access to palliative and end-of-life care. Conclusion: Despite previous patient surveys indicating that patients would prefer to receive care and spend their finals days at home or in a hospice, there appears to be overuse of and overreliance on acute care hospital services near the end-of-life in Canada. The high rates of hospital deaths and admissions through the ED at the end-of-life for cancer patients may signal a lack of planning for impeding death and inadequate availability of or access to community- and home-based palliative and end-of-life care services. Acute care hospitals may have a role in managing the health care needs of people affected by cancer; however, end-of-life care should be an option in other settings that align with patient preferences. Standards or practice guidelines to identify, assess and refer patients to palliative care services earlier in their cancer journey should be developed and implemented to ensure optimal quality of life.

Pan-Canadian Framework for Palliative and End-of-Life Care Research

Background and context: Ongoing advances have been made in the conceptualization and operationalization of palliative and end-of-life care (PEOLC) (e.g., palliative approaches to care, early identification of people who would benefit from palliative care). In addition, Canada has been a leader in PEOLC research and continues to have an internationally recognized research community. However, many Canadians continue to experience unnecessary pain and suffering at the end of life and receive care inconsistent with their goals and preferences. Within this context, the Canadian Cancer Research Alliance (CCRA) sought to develop a national research framework to guide Canada's cancer research funders in response to their strategic priority to improve the patient experience and quality of life for all cancer patients. Aim: To develop and implement a national framework and recommendations to enable funders to capitalize on existing research strengths and build capacity to address unmet needs to advance the field and broaden the scope, beyond its historical affiliation with advanced cancer, to include PEOLC for all those living and dying with life-limiting conditions. Strategy/Tactics: The framework's development was informed by multiple approaches, including: a strategic literature review; an analysis of PEOLC research funding in Canada from 2005-13; and an online survey and key informant interviews from the broader stakeholder community. Program/Policy process: A working group of CCRA member representatives and palliative care experts met regularly to provide guidance and feedback to a consultant who synthesized the data and formulated recommendations. In total, > 200 stakeholders (e.g., patients, caregivers, researchers, volunteers, practitioners, decision-makers, and policy-makers) provided input through the survey and interviews. Outcomes: The Pan-Canadian Framework for Palliative and End-of-Life Research was released March 2017. It emphasizes priorities for research funding across three broad themes: 1) Transforming models of care; 2) Patient and family centredness; and 3) Ensuring equity. The identified research priorities are underpinned by four building blocks: capacity building; knowledge, synthesis, exchange, and implementation; data access and standardization; and research network development. What was learned: Successful implementation of the framework's recommendations requires strong leadership from champions within the community. The formation of the Pan-Canadian Palliative Care Research Collaborative led by palliative care clinician-researchers, in response to the identified need for a research network, is an example of an early success resulting from release of the framework. Continued efforts are needed to ensure ongoing uptake of the framework's recommendations. CCRA members have commenced planning to identify next steps for joint action.

Acute care hospitalization near the end of life for cancer patients who die in hospital in Canada

Acute care hospitals have a role in managing the health care needs of people affected by cancer when they are at the end of life. However, there is a need to provide end-of-life care in other settings, including at home or in hospice, when such settings are more appropriate. Using data from 9 provinces, we examined indicators that describe the current landscape of acute care hospital use at the end of life for patients who died of cancer in hospital in Canada. Interprovincial variation was observed in acute care hospital deaths, length of stay in hospital, readmission to hospital, and intensive care unit use at the end of life. High rates of acute care hospital use near the end of life might suggest that community and home-based end-of-life care might not be suiting patient needs.

Effects of predation and habitat structure on the abundance and population structure of the rock shrimp Rhynchocinetes typus (Caridea) on temperate rocky reefs

Human disturbances, such as overfishing, may disrupt predator-prey interactions and modify food webs. Underwater surveys were carried out at six shallow-water reef barrens in temperate waters of northern-central Chile from October to December 2010 to describe the effects of predation, habitat complexity (low, medium and high) and refuge availability on the abundance and population structure of the rock shrimp Rhynchocinetes typus (Rhynchocinetidae), an important mesoconsumer on subtidal hard substrata. Three sites were within managed (restricted access) areas for fishermen, and three were unmanaged (open-access). Field observations and tethering experiments were conducted to examine the relationship between fish and shrimp abundances, and the relative predation rates on shrimps. Direct effects of predation on R. typus body-size distribution were examined from shrimps collected in the field and fish stomachs. The presence and the abundance of R. typus increased with habitat reef complexity and refuge availability. Shrimp abundance was negatively related to fish abundance in managed areas, but not in open-access areas, where shrimp densities were the highest. Also, predation rates and body-size distribution of shrimps were unrelated, although fish consumed more large shrimps than should be expected from their distribution in the field. R. typus occurred most often in shelters with wide openings, offering limited protection against predators, but providing potential aggregation sites for shrimps. Overall, direct effects of predation on shrimp densities and population structure were weak, but indirect effects on shrimp distribution within reefs appear to have been mediated through behavioural responses. Our study highlights the need to assess both numerical and behavioural responses of prey to determine the effects of predator loss on mesoconsumer populations.

Asian river fishes in the Anthropocene: threats and conservation challenges in an era of rapid environmental change

This review compares and contrasts the environmental changes that have influenced, or will influence, fishes and fisheries in the Yangtze and Mekong Rivers. These two rivers have been chosen because they differ markedly in the type and intensity of prevailing threats. The Mekong is relatively pristine, whereas the Three Gorges Dam on the Yangtze is the world's largest dam representing the apotheosis of environmental alteration of Asian rivers thus far. Moreover, it is situated at the foot of a planned cascade of at least 12 new dams on the upper Yangtze. Anthropogenic effects of dams and pollution of Yangtze fishes will be exacerbated by plans to divert water northwards along three transfer routes, in part to supplement the flow of the Yellow River. Adaptation to climate change will undoubtedly stimulate more dam construction and flow regulation, potentially causing perfect storm conditions for fishes in the Yangtze. China has already built dams along the upper course of the Mekong, and there are plans for as many as 11 mainstream dams in People's Democratic Republic (Laos) and Cambodia in the lower Mekong Basin. If built, they could have profound consequences for biodiversity, fisheries and human livelihoods, and such concerns have stalled dam construction. Potential effects of dams proposed for other rivers (such as Nujiang-Salween) are also cause for concern. Conservation or restoration measures to sustain some semblance of the rich fish biodiversity of Asian rivers can be identified, but their implementation may prove problematic in a context of increasing Anthropocene alteration of these ecosystems.

An inventory of riverine biodiversity in monsoonal Asia: present status and conservation challenges

There are few parts of the planet where human impacts on riverine biodiversity are more apparent than in monsoonal Asia. Flow regulation, drainage-basin degradation and conversion of riverine wetlands to agriculture have been occurring for centuries, while pollution and over-harvesting have become important in recent decades. Concomitant species loss appears both ongoing and rampant. Uncertainty over rates of loss is imposed by the fact that the extremely rich biodiversity of Asian rivers has not been inventoried adequately. It is nevertheless evident that some taxa are gravely threatened. Specialist riverine birds have declined, turtles are highly endangered, and over-harvesting has severely impacted fishes--an effect that is exacerbated by pollution and flow regulation. A particular conflict that constrains biodiversity conservation is the tendency for dam construction, which damages river ecosystems, to produce tangible benefits for humans through hydropower generation and relief from floods and droughts. Resolution of such conflicts requires changes in perception: for instance, realistic economic valuations of the ecosystem goods and services provided by rivers, and promotion of flagship species as conservation icons to increase citizen awareness. Translation of awareness and knowledge to action, however, remains the essential prerequisite for societal commitment to the conservation of freshwater ecosystems.

The Canadian Palliative Care Education Group

The Canadian Palliative Care Education Group, a committee of the Canadian Society of Palliative Care Physicians, carries out surveys from time to time on the status of palliative care education in Canadian medical schools. We describe the organization of the Canadian Palliative Care Education Group and report on a survey carried out in the 1996-97 academic year. Our data suggest that the emphasis on palliative care varies widely amongst the 16 Canadian medical schools, in concert with the availability of academic staff positions in palliative care. We conclude that the need for palliative care education is supported by rhetoric which remains to be matched by proportionate tangible investment.

Perceptions of the role of the school in providing information and support to adolescent children of women with breast cancer

Little is known about the needs of adolescents of women with breast cancer. The purpose of this study was to describe the perceptions of adolescents (ages 12-20) about the role of the school in assisting them in dealing with the cancer experience. An exploratory, qualitative study was done to elicit detailed descriptions of adolescent's needs for information and support in response to their mother's breast cancer. A convenience sample of 31 adolescents of women in five illness phases participated in semi-structured interviews. In addition, two focus group interviews were conducted. Interviews were tape-recorded, transcribed and analysed using content analysis techniques. Findings specific to the adolescents' perceptions of the role of the school were discussed according to content, type, amount, timing, provider and quality of information. Support needs were discussed as type of support, source of support, amount, timing and focus. Although school personnel attempted to be supportive and adolescents received generic information about cancer, overall the needs of the adolescents were not adequately addressed. Recommendations for schools and health services in assisting adolescents to cope with this major life experience are made.

Pediatric perineal impalement injuries

Pediatric perineal impalement injuries are relatively uncommon. There may be difficulty in recognizing or properly treating such injuries, because their severity may not be reflected accurately by the external appearance of the perineum. The authors describe 3 case reports of patients with perineal impalement injuries and their management. The authors emphasize how a thorough workup can prevent missed injuries, leading to timely surgical repair and good outcomes.

Will to live in the terminally ill

BACKGROUND

Complex biomedical and psychosocial considerations figure prominently in the debate about euthanasia and assisted suicide. No study to date, however, has examined the extent to which a dying patient's will to live fluctuates as death approaches.

METHODS

This study examined patients with cancer in palliative care. Will to live was measured twice daily throughout the hospital stay on a self-report 100 mm visual analogue scale. This scale was incorporated into the Edmonton symptom assessment system, a series of visual analogue scales measuring pain, nausea, shortness of breath, appetite, drowsiness, depression, sense of well-being, anxiety, and activity. Maximum and median fluctuations in will-to-live ratings, separated by 12 h, 24 h, 7 days, and 30 days, were calculated for each patient.

FINDINGS

Of 585 patients admitted to palliative care during the study period (November, 1993, to May, 1995), 168 (29%; aged 31-89 years) met criteria of cognitive and physical fitness and agreed to take part. The pattern of median changes in will-to-live score suggested that will to live was stable (median changes <10 mm on 100 mm scale for all time intervals). By contrast, the average maximum changes in will-to-live score were substantial (12 h 33.1 mm, 24 h 35.8 mm, 7 days 48.8 mm, 30 days 68.0 mm). In a series of stepwise regression models carried out at 12 h, 24 h, and 1-4 weeks after admission, the four main predictor variables of will to live were depression, anxiety, shortness of breath, and sense of well-being, with the prominence of these variables changing over time.

INTERPRETATION

Among dying patients, will to live shows substantial fluctuation, with the explanation for these changes shifting as death approaches.

A Canadian survey of issues in cancer pain management

We report the analysis of a cancer management survey mailed to a representative group of health professionals in 1994. The goals of the study were to gather information on cancer pain treatment practices, and to obtain health professional views on obstacles to ideal pain management. The survey, designed by a working party of pharmacists, nurses and physicians, was distributed to 14,628 physicians. A total of 2,686 physicians responded to the survey, including 39% of medical or radiation oncologists, and 18.19% of physicians who listed their primary interest as Family Medicine. Reflecting the modest emphasis placed on palliative care and cancer pain management in the current Canadian milieu, 67% of physicians rated their past teaching experience as only "fair" or "poor." Lack of exposure to pain education was reflected in the response to a series of hypothetical case scenarios exploring physician choices in managing severe cancer pain. For example, in the initial management of a cancer patient with severe pain, 50% of physicians would not use a strong opioid in the absence of other contraindications to opioid use. A wide variety of analgesics and non-pharmacologic techniques is available to Canadian physicians to assist patients with pain. Few physicians identified the unavailability of analgesics or analgesic techniques as limiting factors in pain management. We conclude that greater emphasis should be placed on pain education in our training programmes. We suggest that further surveys of this type, sponsored by our provincial colleges and medical organizations, can provide feedback which will enhance the adherence by Canadian physicians to published guidelines for pain management.

Evaluation of an interdisciplinary training program in palliative care: addressing the needs of rural and northern communities

Our study was a pilot test of an interdisciplinary training program in palliative care to improve the quality of care to terminally ill cancer and AIDS patients in rural and northern communities in Manitoba. The program involved two weeks of intense palliative care training for nurses, social workers, physicians, and volunteers. Four teams were trained during a six-month period. A repeated measures design was used to assess the effectiveness of the program. Results indicated that health professionals' knowledge about care of the dying, care of individuals with HIV/AIDS, and attitudes toward care of the dying improved upon completion of the training program and remained improved three months following the program. Improvements in use of medications, increased attention to family care, increased discussion of DNR orders, and increased consultation related to symptom management were evident following the training program. The parallel training program for volunteers was also judged to be effective.

Family members' perceptions of palliative cancer care: predictors of family functioning and family members' health

We studied family members' care experiences during the palliative care phase as predictors of family members' health and family functioning during the palliative care phase and three months following the death of the patient. Eighty family members of advanced cancer patients participated in the study at time one (T1) (palliative care phase) and 64 family members completed the data collection protocol at time two (T2) (three months bereavement). Data were also obtained from 36 of the patients within one month of their deaths. Fulfillment theory accounted for 31% of the variance in family care satisfaction and Discrepancy theory accounted for 72% of the variance in family care satisfaction. Discrepancy theory predicted family functioning in the bereavement period (r = -0.33, p < 0.05). Patients' quality of life scores were moderately correlated with family members' health during the palliative care phase (r = -0.38, p < 0.05). Family members' scores on the health index (symptom of stress scale) were significantly lower (p < 0.05) than normative scores reported in a study using a healthy population. The strongest predictor of family members' health scores in the bereavement period was their health score at T1 (r = 0.71, p < 0.01). As well, family functioning at T1 was strongly correlated with family functioning at T2.

A comparison of patient-reported side effects among three chemotherapy regimens for breast cancer

Patient's perceptions of side effects and the influence of treatment on daily activities are important considerations in choosing a chemotherapy regimen. However, there are no studies comparing patients' experiences with three commonly used chemotherapy regimens for breast cancer. The authors compared the patient-reported side effects and disruption in usual activities for cyclophosphamide and fluorouracil combined with methotrexate (CMF), doxorubicin (CAF), or mitoxantrone (CNF) in 86 women receiving treatment for breast cancer. The incidence and severity of side effects and disruption in usual activities were recorded by patients in a self-care diary (SCD) 2 and 5 days after the first and second drug cycles. Patients reported a mean of 3.2 to 4.9 side effects at each point in time. Fatigue, nausea, anorexia, taste changes, and headache were the most frequently reported side effects and did not differ in incidence among the three drug regimens. When repeated measures analysis of covariance was conducted using mean substitution for missing data and controlling for stage of disease, women receiving CAF reported more severe nausea than women receiving CMF or CNF (P < 0.05). Fatigue was significant for time; however, a distinct clinical pattern of fatigue was not apparent. Patients reported moderate levels of disruption in activities of daily living, with those receiving CAF having greater disruption. There was no difference among treatment groups in reports of overall disruption in activities. These data on patient reported experiences with side effects of chemotherapy can be used to prepare patients for specific side effects of treatment and facilitate symptom management.

The short-form McGill Pain Questionnaire in chronic cancer pain

A short form of the McGill Pain Questionnaire (SF-MPQ) was previously developed. It was found to correlate highly with and demonstrate differences due to treatment in a manner similar to the long form of the McGill Pain Questionnaire (LF-MPQ). The LF-MPQ was previously found to be a valid measurement of pain in the cancer population. The present study demonstrated that the sensory, affective, and total scores of the SF-MPQ correlated highly with the LF-MPQ on three administrations, each 3-4 wk apart in 24 patients with chronic pain due to cancer. Both the long and short total scores correlated highly with the visual analogue scale (VAS) and present pain intensity (PPI) scale. The SF-MPQ demonstrated changes over time in a manner similar to the LF-MPQ in this patient group. These observations support the value of the SF-MPQ as a tool for studying interventions in patients with chronic pain due to cancer.

The Potmidae and Parathelphusidae (Crustacea : Decapoda : Brachyura) of Hong Kong

The taxonomy of three freshwater crabs from Hong Kong is discussed. Two poorly known potamid species, Potamon anacoluthon Kemp, 1918, and Potamon hongkongensis Shen, 1940, are referred to Cryptopotamon, gen. nov., and Nanhaipotamon Bott, 1968, respectively. The taxonomic problems associated with the genus Nanhaipotamon are briefly reviewed. The identity of the parathelphusid Somanniathelphusa sinensis (H. Milne Edwards, 1853) is clarified on re-examination of the types, and two new species, S. falx (from China) and S. zanklon (from Hong Kong), are described. Notes on the general biology of the three Hong Kong species are also provided.

Differential palatability of leaf litter to four sympatric isopods in a Hong Kong forest

The feeding behaviour of four sympatric isopods from a Hong Kong forest has been investigated. The study included two armadillids (Formosillo raffaelei and Orodillo maculatus) and two philosciids (Burmoniscus ocellatus and Burmoniscus sp.). When given a choice of eight types of litter, all isopod species showed significant dietary selection, and food preferences were similar. Berchemia racemosa (Rhamnaceae) was most readily consumed, followed by Celtis sinensis (Ulmaceac), while feeding rates on Cinnamomum camphora (Lauraceae) were low. The armadillids exhibited a narrower dietary spectrum than the philosciids. All isopods showed significant differences in consumption rates when each litter type was presented separately to them. Cinnamomum camphora was eaten the slowest, while Celtis sinensis and Berchemia racemosa were the top-ranked species. Although patterns of litter ranking based on percentage eaten or feeding rates were similar, all isopods ate more food when given a mixture of leaves than when presented with a single litter type. Assimilation rates were, in general, positively related to feeding rates. On this basis, it appears that assimilation may influence food preference. There were no clear relationships between food preference or feeding rates and ash, calcium, copper, soluble tannin or energy content of the litter. This finding may indicate the benefits of isopods maintaining a mixed diet, consuming certain litter species to meet their calcium or copper requirements and then switching to others so as to meet daily energy needs and to avoid excessive injection of tannins or plant allelochemicals.

Total parenteral nutrition and intestinal development: a neonatal model

Total parenteral nutrition (TPN) is widely used in premature and/or surgical neonates, but there is little information available about its effects on intestinal growth and development. Adult TPN models have demonstrated mucosal atrophy, and a young piglet model showed similar but increased intestinal hypotrophy. We have investigated these effects in the neonatal piglet model. Five three-day old piglets received a glucose (40 g/kg/d), amino acid (8 g/kg/d), and fat (4 g/kg/d) solution intravenously for 3 weeks. Matched littermates were fed an artificial sow-milk formula enterally at an equivalent caloric rate (215 kcal/kg/d). A third littermate was sow breast fed for the same study period. No differences were seen in the TPN or formula-fed piglets in weight gain (31 to 34 g/kg/d), hematocrit (25% to 27%), BUN (12 to 13 mg/dL), total serum protein (4.1 to 4.4 g/dL), or total bilirubin (0.4 to 0.6 mg/dL); however, the TPN animals were mildly hyperglycemic (167 mg/dL). The sow-fed control group had greater weight gain (51 g/kg/d) but were without caloric restriction. There were significant decreases in weight and length of the gastrointestinal tract, particularly in the proximal small bowel of the TPN piglets. Compared with formula piglets or sow-fed controls, the TPN proximal small bowel weight was reduced by 67% and 72%, respectively. Similar but less marked differences were seen in the TPN distal small bowel. There were no significant differences in the proximal or distal small bowel measurements between the formula and sow-fed piglets, despite their differences in overall weight gain.(ABSTRACT TRUNCATED AT 250 WORDS)