Embracing the continuity of care experience: A new Australian graduate entry master of midwifery course with a student caseload of 15 women per year

BACKGROUND

Women receiving continuity of midwifery care have increased satisfaction and improved outcomes. Preparation of midwifery students to work in continuity models from the point of graduation may provide an ongoing midwifery workforce that meets rising demand from women for access to such care.

AIM OF THE PAPER

The aim of this paper is to describe an innovative midwifery course based on a continuity model, where students acquire more than 50 % of clinical hours through continuity of care experiences. Additional educational strategies incorporated in the course to enhance the CCE experience within the philosophy of midwifery care, include a virtual maternity centre, case-based learning and the Resources Activities Support Evaluation (RASE) pedagogical model of learning.

DISCUSSION

Australian accredited midwifery courses vary in structure, format and philosophy; this new course provides students with an alternative option of study for those who have a particular interest in continuity of midwifery care.

CONCLUSION

A midwifery course which provides the majority of clinical hours through continuity of care may prepare graduates for employment within midwifery group practice models by demonstrating the benefits of relationship building, improved outcomes and the reality of an on-call lifestyle.

Feeding forage or concentrates early in life influences rumen fermentation, metabolic response, immune function and growth of Wagyu × Friesian calves

Context Early life nutrition of calves influences their performance later in life. There is limited literature demonstrating the effects of rearing dairy calves in early life on milk with either exclusively forage or concentrate starter diets on metabolic and immune function and post-weaning growth and body composition on a pasture only diet. Aim This study evaluated the effects of feeding Wagyu × Holstein Friesian calves a forage starter (FS) or a concentrate starter (CS) for the first 14 weeks of rearing on rumen fermentation, blood metabolites, immune function, growth and body composition to Week 41. Methods Group-housed calves (Wagyu × Friesian, 10 calves per group, three groups per treatment) were fed milk (2 L per calf twice daily) until Week 7, then transitioned to once a day milk feeding until weaning by Week 9, with ad libitum access to either FS or CS. All calves were transferred to graze ryegrass pastures a week after transitioning to once daily milk feeding, with starter feeds removed gradually by Week 14. Thereafter, calves were reared together on pasture until Week 41. Results Solid feed intake was lower in FS than CS calves during the first 7 weeks. Total short chain fatty acids were lower, but acetate to propionate ratio and rumen pH were higher in FS than CS calves at Week 7, with no differences observed at Week 12 or 30. Plasma β-hydroxybutyrate an indicator of ketogenic ability of the rumen in developing calves was higher in FS vs CS calves at weaning. Further, FS calves had lower concentrations of circulating non-esterified fatty acids compared with CS calves at weaning. Compared with CS calves, FS calves grew slower for the first 14 weeks which was associated with lower plasma IGF-1 levels. However, FS calves had greater average daily gain after 14 weeks when on pasture and had similar plasma IGF-1 at 30 weeks and similar body weight and body composition (muscle and subcutaneous fat deposition) by Week 41 compared to CS calves. Conclusions These results indicate that offering a FS starter has better prepared calves for weaning onto pasture and potentially improved utilisation of forage post-weaning to achieve similar muscle and fat deposition and overall liveweight in both groups by 41 weeks. Implications Dairy beef calves can be successfully reared using forage as the only solid feed source without affecting their growth performance on pasture until 10 months of age. Rearing calves using forage will contribute to reducing the usage of concentrate feeds in pastoral dairy-beef production systems and provide an opportunity to fulfil the market requirements and standards for grain-free beef production.

Circulating tumor DNA as a potential marker of adjuvant chemotherapy benefit following surgery for localized pancreatic cancer

BACKGROUND

In early-stage pancreatic cancer, there are currently no biomarkers to guide selection of therapeutic options. This prospective biomarker trial evaluated the feasibility and potential clinical utility of circulating tumor DNA (ctDNA) analysis to inform adjuvant therapy decision making.

MATERIALS AND METHODS

Patients considered by the multidisciplinary team to have resectable pancreatic adenocarcinoma were enrolled. Pre- and post-operative samples for ctDNA analysis were collected. PCR-based-SafeSeqS assays were used to identify mutations at codon 12, 13 and 61 of KRAS in the primary pancreatic tumor and to detect ctDNA. Results of ctDNA analysis were correlated with CA19-9, recurrence-free and overall survival (OS). Patient management was per standard of care, blinded to ctDNA data.

RESULTS

Of 112 patients consented pre-operatively, 81 (72%) underwent resection. KRAS mutations were identified in 91% (38/42) of available tumor samples. Of available plasma samples (N = 42), KRAS mutated ctDNA was detected in 62% (23/37) pre-operative and 37% (13/35) post-operative cases. At a median follow-up of 38.4 months, ctDNA detection in the pre-operative setting was associated with inferior recurrence-free survival (RFS) [hazard ratio (HR) 4.1; P = 0.002)] and OS (HR 4.1; P = 0.015). Detectable ctDNA following curative intent resection was associated with inferior RFS (HR 5.4; P < 0.0001) and OS (HR 4.0; P = 0.003). Recurrence occurred in 13/13 (100%) patients with detectable ctDNA post-operatively, including in seven that received gemcitabine-based adjuvant chemotherapy.

CONCLUSION

ctDNA studies in localized pancreatic cancer are challenging, with a substantial number of patients not able to undergo resection, not having sufficient tumor tissue for analysis or not completing per protocol sample collection. ctDNA analysis, pre- and/or post-surgery, is a promising prognostic marker. Studies of ctDNA guided therapy are justified, including of treatment intensification strategies for patients with detectable ctDNA post-operatively who appear at very high risk of recurrence despite gemcitabine-based adjuvant therapy.

Midwives' experience of their education, knowledge and practice around immersion in water for labour or birth

BACKGROUND

There is limited research examining midwives' education, knowledge and practice around immersion in water for labour or birth. Our aim was to address this gap in evidence and build knowledge around this important topic.

METHODS

This mixed method study was performed in two phases, between August and December 2016, in the birth centre of a tertiary public maternity hospital in Western Australia. Phase one utilised a cross sectional design to examine perceptions of education, knowledge and practice around immersion in water for labour or birth through a questionnaire. Phase two employed a qualitative descriptive design and focus groups to explore what midwives enjoyed about caring for women who labour or birth in water and the challenges midwives experienced with waterbirth. Frequency distributions were employed for quantitative data. Thematic analysis was undertaken to extract common themes from focus group transcripts.

RESULTS

The majority (85%; 29 of 34) of midwives surveyed returned a questionnaire. Results from phase one confirmed that following training, 93% (27 of 29) of midwives felt equipped to facilitate waterbirth and the mean waterbirths required to facilitate confidence was seven. Midwives were confident caring for women in water during the first, second and third stage of labour and enjoyed facilitating water immersion for labour and birth. Finally, responses to labour and birth scenarios indicated midwives were practicing according to state-wide clinical guidance. Phase two included two focus groups of seven and five midwives. Exploration of what midwives enjoyed about caring for women who used water immersion revealed three themes: instinctive birthing; woman-centred atmosphere; and undisturbed space. Exploration of the challenges experienced with waterbirth revealed two themes: learning through reflection and facilities required to support waterbirth.

CONCLUSIONS

This research contributes to the growing knowledge base examining midwives' education, knowledge and practice around immersion in water for labour or birth. It also highlights the importance of exploring what immersion in water for labour and birth offers midwives, as this research suggests they are integral to sustaining waterbirth as an option for low risk women.

The perceptions and experiences of women who achieved and did not achieve a waterbirth

BACKGROUND

There is a gap in knowledge and understanding relating to the experiences of women exposed to the opportunity of waterbirth. Our aim was to explore the perceptions and experiences of women who achieved or did not achieve their planned waterbirth.

METHODS

An exploratory design using critical incident techniques was conducted between December 2015 and July 2016, in the birth centre of the tertiary public maternity hospital in Western Australia. Women were telephoned 6 weeks post birth. Demographic data included: age; education; parity; and previous birth mode. Women were also asked the following: what made you choose to plan a waterbirth?; what do you think contributed to you having (or not having) a waterbirth?; and which three words would you use to describe your birth experience? Frequency distributions and univariate comparisons were employed for quantitative data. Thematic analysis was undertaken to extract common themes from the interviews.

RESULTS

A total of 31% (93 of 296) of women achieved a waterbirth and 69% (203 of 296) did not. Multiparous women were more likely to achieve a waterbirth (57% vs 32%; p < 0.001). Women who achieved a waterbirth were less likely to have planned a waterbirth for pain relief (38% vs 52%; p = 0.24). The primary reasons women gave for planning a waterbirth were: pain relief; they liked the idea; it was associated with a natural birth; it provided a relaxing environment; and it was recommended. Two fifths (40%) of women who achieved a waterbirth suggested support was the primary reason they achieved their waterbirth, with the midwife named as the primary support person by 34 of 37 women. Most (66%) women who did not achieve a waterbirth perceived this was because they experienced an obstetric complication. The words women used to describe their birth were coded as: affirming; distressing; enduring; natural; quick; empowering; and long.

CONCLUSIONS

Immersion in water for birth facilitates a shift of focus from high risk obstetric-led care to low risk midwifery-led care. It also facilitates evidence based, respectful midwifery care which in turn optimises the potential for women to view their birthing experience through a positive lens.

Australian, Irish and Swedish women's perceptions of what assisted them to breastfeed for six months: exploratory design using critical incident technique

Background

Breastfeeding initiation rates in some developed countries are high (98 % in Sweden and 96 % in Australia) whereas in others, they are not as favourable (46 % to 55 % in Ireland). Although the World Health Organization recommends exclusively breastfeeding for six months, 15 % of Australian women, 11 % of Swedish women and less than 7 % of Irish women achieve this goal. Awareness of what women in different countries perceive as essential breastfeeding support is a gap in our knowledge.

Methods

Our aim was to explore Australian, Irish and Swedish women’s perceptions of what assisted them to continue breastfeeding for six months. An exploratory design using critical incident techniques was used. Recruitment occurred through advertisements in local newspapers and on social networking platforms. Initial sampling was purposive, followed by snowball sampling. Telephone interviews were conducted with 64 Irish, 139 Swedish and 153 Australian women who responded to one question “what has assisted you to continue breastfeeding for at least six months?” Content analysis was conducted and common categories determined to allow comparison of frequencies and priority ranking.

Results

Categories reflected the individual mother, her inner social network, her outer social network (informal support either face to face or online), and societal support (health professionals, work environment and breastfeeding being regarded as the cultural norm). Categories ranked in the top five across the three countries were ‘informal face to face support’ and ‘maternal determination’. Swedish and Australian women ranked “health professional support” higher (first and third respectively) than Irish women who ranked ‘informal online support’ as second compared to ninth and tenth for Swedish and Australian women.

Conclusions

The support required to assist breastfeeding women is complex and multi-faceted. Although common international categories were revealed, the ranking of these supportive categories varied. We must recognize how the cultural context of breastfeeding support can vary for women in differing countries and acknowledge the resourcefulness of women who embrace innovations such as social media where face to face formal and informal support are not as accessible.

A 4-arm randomized controlled pilot trial of innovative solutions for jugular central venous access device securement in 221 cardiac surgical patients

PURPOSE

To improve jugular central venous access device (CVAD) securement, prevent CVAD failure (composite: dislodgement, occlusion, breakage, local or bloodstream infection), and assess subsequent trial feasibility.

MATERIALS AND METHODS

Study design was a 4-arm, parallel, randomized, controlled, nonblinded, pilot trial. Patients received CVAD securement with (i) suture+bordered polyurethane (suture + BPU; control), (ii) suture+absorbent dressing (suture + AD), (iii) sutureless securement device+simple polyurethane (SSD+SPU), or (iv) tissue adhesive+simple polyurethane (TA+SPU). Midtrial, due to safety, the TA+SPU intervention was replaced with a suture + TA+SPU group.

RESULTS

A total of 221 patients were randomized with 2 postrandomization exclusions. Central venous access device failure was as follows: suture + BPU controls, 2 (4%) of 55 (0.52/1000 hours); suture + AD, 1 (2%) of 56 (0.26/1000 hours, P=.560); SSD+SPU, 4 (7%) of 55 (1.04/1000 hours, P=.417); TA+SPU, 4 (17%) of 23 (2.53/1000 hours, P=.049); and suture + TA+SPU, 0 (0%) of 30 (P=.263; intention-to-treat, log-rank tests). Central venous access device failure was predicted (P<.05) by baseline poor/fair skin integrity (hazard ratio, 9.8; 95% confidence interval, 1.2-79.9) or impaired mental state at CVAD removal (hazard ratio, 14.2; 95% confidence interval, 3.0-68.4).

CONCLUSIONS

Jugular CVAD securement is challenging in postcardiac surgical patients who are coagulopathic and mobilized early. TA+SPU was ineffective for CVAD securement and is not recommended. Suture + TA+SPU appeared promising, with zero CVAD failure observed. Future trials should resolve uncertainty about the comparative effect of suture + TA+SPU, suture + AD, and SSD+SPU vs suture + BPU.

Hydrodynamic evaluation of aortic cardiopulmonary bypass cannulae using particle image velocimetry

The high velocity jet from aortic arterial cannulae used during cardiopulmonary bypass potentially causes a "sandblasting" injury to the aorta, increasing the possibility of embolisation of atheromatous plaque. We investigated a range of commonly available dispersion and non-dispersion cannulae, using particle image velocimetry. The maximum velocity of the exit jet was assessed 20 and 40 mm from the cannula tip at flow rates of 3 and 5 L/min. The dispersion cannulae had lower maximum velocities compared to the non-dispersion cannulae. Dispersion cannulae had fan-shaped exit profiles and maximum velocities ranged from 0.63 to 1.52 m/s when measured at 20 mm and 5 L/min. Non-dispersion cannulae had maximum velocities ranging from 1.52 to 3.06 m/s at 20 mm and 5 L/min, with corresponding narrow velocity profiles. This study highlights the importance of understanding the hydrodynamic performance of these cannulae as it may help in selecting the most appropriate cannula to minimize the risk of thromboembolic events or aortic injury.

Abstract P4-19-02: Early experience of patient donation and researcher use of tissues donated to a national breast cancer tissue bank

The need for a specialist breast cancer biobank was recognised through a Gap Analysis conducted by the UK charity, Breast Cancer Campaign (Thompson AM et al., Breast Cancer Res 2008: 10(2); R26). As a result The Breast Cancer Campaign Tissue Bank (www.breastcancertissuebank.org) was launched in 2010 as a coalition of 4 centres of excellence for breast cancer research in the UK. Breast cancer patients presenting to these centres are offered the opportunity to donate surplus tissue and bloods to The Breast Cancer Campaign Tissue Bank. Researchers can apply for these samples by completing a simple on line application form. Here we describe our early experience of patient donation to The Breast Cancer Campaign Tissue Bank and outline the sample requests received from researchers to date. Most of the first year of operation (2010) was spent developing SOPs and ensuring collection protocols were robust, with some limited prospective collection. The collection was pump-primed from existing resources. By 2011 all sites were operational and working to the same standards. Over a 2 year period (Jan 2011 - Dec 2012), over 90% of suitable patients (1803) consented to tissue donation. From these we derived 3951 frozen tissue aliquots, 1517 formalin-fixed paraffin-embedded cases and 2012 blood derivatives (serum, plasma and whole blood). Asian patients were less likely to consent while younger patients tended not to donate blood, but were happy to donate tissue. All male patients consented to tissue and blood donation. At Dec 2012, the total numbers of sample aliquots derived from these donated tissue and blood samples was 22, 127. This includes frozen and formalin-fixed paraffin-embedded tissues, serum, plasma and whole blood. At present, application for tissue samples is restricted to the UK and Ireland but we aim to open to international applications in the near future. All applications are reviewed by an international Tissue Access Committee which includes appropriate clinical and scientific expertise plus representation by patient advocates. At 1st June 2013, seventeen applications had been received, of which 14 were approved. Three applications were rejected, made on the basis that the applicants were not making the best use of the donated material. Thus far, tissues have been dispatched to 9 researchers with 5 in preparation. These include 465 formalin-fixed paraffin-embedded cases and 158 frozen samples, all provided with a basic minimum dataset. Early experience of patient consent was encouraging with patients overall very enthusiastic and willing to donate to our biobanking programme. More research is needed to help understand the barriers in preventing ethnic minorities to donate and the reluctance in some young people to donate blood samples. Interest by the breast cancer research community in accessing samples is steadily rising as the resource becomes more widely known and increased website traffic is translating into applications for tissues. This has been an ambitious multidisciplinary endeavour but we are building a valuable resource to service the needs of the breast cancer research community with the goal of helping translate laboratory results into clinical benefit.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-19-02.

Prolactin acts on the hypothalamic-pituitary axis to modulate follicle-stimulating hormone gene expression in the female brushtail possum (Trichosurus vulpecula)

Brushtail possums exhibit a distinct preovulatory pattern of prolactin (Prl) secretion suggesting that Prl is involved in normal reproductive function. In some mammals, Prl is essential for corpus luteum (CL) function and/or modulation of steroidal effects on hypothalamic-pituitary activity. The aim of this study was to test the effects of biologically active recombinant possum Prl (recPosPrl) on both pituitary gland and CL function in possums. To confirm biological activity, administration of recPosPrl-N2C1 (10 μg) resulted in an 18-fold stimulation (P<0.05) of progesterone (P(4)) production by possum granulosa cells in vitro. Based on these findings, minipumps containing either recPosPrl-N2C1 (n=10) or saline (n=8) were inserted into lactating female possums. The expression levels of pituitary-derived PRL, LHB, FSHB and GNRHR and CL-derived LHR mRNA were quantified. Following a resumption of reproductive activity, no differences in ovulation incidence or plasma Prl concentrations were observed. Plasma Prl levels were less variable (P<0.001) in Prl-treated possums, confirming a self-regulatory role for Prl in this species. There was a marked down-regulation (P<0.001) of FSHB mRNA at the mid-luteal stage in Prl-treated possums, whereas mean PRL, LHB, GNRHR and LHR mRNA expression levels were not different between experimental groups. Plasma P(4) concentrations were not different (P=0.05) in Prl-treated possums, although tended to be higher in the peri-ovulatory and early-luteal phase. We conclude in the brushtail possum that Prl is self-regulated via a short-feedback loop common to all mammals studied and is able to modulate FSHB expression probably at the level of the hypothalamus and/or pituitary gland.

Type 2 diabetes does not worsen prognosis in hepatocellular carcinoma

INTRODUCTION

Type 2 diabetes (T2DM) is associated with liver inflammation and carcinogenesis. The prevalence of T2DM among patients with liver cirrhosis and hepatocellular carcinoma is increasing. However, the effect of T2DM on the natural history of hepatocellular carcinoma is not known.

AIM

To examine the effect of T2DM on hepatocellular carcinoma (HCC) survival in treated and untreated disease.

METHODS

Retrospective analysis was performed on HCC cases diagnosed during 2000-2005, and prospectively during 2006-August 2007. Demographics, HCC staging, response to treatment, and survival were collected. A comparison was made between patients with T2DM and without T2DM.

RESULTS

One hundred and thirty-five patients were recruited in total; 58 (43%) had T2DM. Seventy (37 diabetic) patients were treated with percutaneous radiological therapies, with 168 treatments given. Treatment was determined by AASLD guidelines and patient tolerance, there was no randomisation. There was no significant difference in survival between diabetic and nondiabetic patients. There was a nonsignificant trend towards greater survival in diabetic patients (overall median survival diabetics 21 mths vs nondiabetics 5 mths, P=0.355).

CONCLUSIONS

T2DM does not negatively impact on the natural history of treated or untreated HCC.

Diagnosis of solid pancreatic masses by endoscopic ultrasound-guided fine-needle aspiration

BACKGROUND

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is increasingly being used in the staging algorithm for pancreatic carcinoma. This allows for a tissue diagnosis, which was previously difficult to obtain. The aim of this study is to assess the utility of EUS-FNA in establishing the diagnosis of solid pancreatic mass lesions in an Australian population.

METHODS

A retrospective review of the EUS databases of St Vincent's Hospital Melbourne and Western Hospital, Melbourne from November 2002 to May 2006 was undertaken. The focus was on patients with a solid pancreatic mass who underwent EUS-FNA. Surgical pathology or long-term follow up was used to identify false-positive or false-negative results.

RESULTS

EUS was undertaken to investigate a solid pancreatic or distal common bile duct mass lesion in 155 patients. Seventy-two of these underwent EUS-guided FNA. Mean age was 68 years. A positive tissue diagnosis of malignancy could be made in 55 (76%). Nine (13%) had benign histology, with 8 (11%) having inadequate tissue obtained from FNA. A later tissue diagnosis of carcinoma was made in eight of those with either benign or inadequate histology, although in all cases there were EUS features diagnostic of malignancy, with FNA limited by technical difficulties. The overall utility of EUS-FNA showed a sensitivity of 87%, specificity 100%, positive predictive value 100%, negative predictive value 52% and overall accuracy 89%.

CONCLUSION

EUS-FNA gives a high return for histological diagnosis of solid pancreatic mass lesions and should be part of the standard management algorithm for pancreatic carcinoma.

Diagnosis of solid pancreatic masses by endoscopic ultrasound-guided fine-needle aspiration

BACKGROUND

Endoscopic ultrasound (EUS) with fine-needle aspiration (FNA) is increasingly being used in the staging algorithm for pancreatic carcinoma. This allows for a tissue diagnosis, which was previously difficult to obtain. The aim of this study is to assess the utility of EUS-FNA in establishing the diagnosis of solid pancreatic mass lesions in an Australian population.

METHODS

A retrospective review of the EUS databases of St Vincent's Hospital Melbourne and Western Hospital, Melbourne from November 2002 to May 2006 was undertaken. The focus was on patients with a solid pancreatic mass who underwent EUS-FNA. Surgical pathology or long-term follow up was used to identify false-positive or false-negative results.

RESULTS

EUS was undertaken to investigate a solid pancreatic or distal common bile duct mass lesion in 155 patients. Seventy-two of these underwent EUS-guided FNA. Mean age was 68 years. A positive tissue diagnosis of malignancy could be made in 55 (76%). Nine (13%) had benign histology, with 8 (11%) having inadequate tissue obtained from FNA. A later tissue diagnosis of carcinoma was made in eight of those with either benign or inadequate histology, although in all cases there were EUS features diagnostic of malignancy, with FNA limited by technical difficulties. The overall utility of EUS-FNA showed a sensitivity of 87%, specificity 100%, positive predictive value 100%, negative predictive value 52% and overall accuracy 89%.

CONCLUSION

EUS-FNA gives a high return for histological diagnosis of solid pancreatic mass lesions and should be part of the standard management algorithm for pancreatic carcinoma.

Hepatic stellate cells on poly(DL-lactic acid) surfaces control the formation of 3D hepatocyte co-culture aggregates in vitro

Evidence for the functional superiority of cells cultured as 3D aggregates or on 3D scaffolds over conventional 2D monolayer cultures has created interest in material and cell based methods that influence the formation and structure of multicellular aggregates in vitro. We have created a co-culture of primary rat hepatocytes and hepatic stellate cells on a poly(DL-lactic acid) surface, a poor substrate for rat hepatocyte adhesion, to study the dynamics of multicellular spheroid formation and the resultant cell arrangement. The poly(DL-lactic acid) surface allows dynamic and rapid interaction of hepatocytes and stellate cells to form co-culture spheroids in a complex multistage process (shown by time lapse microscopy). This spheroid morphology supports enhanced cell viability relative to a mono-culture mono-layer system (measured by lactate dehydrogenase leakage). The distribution of the aggregating cell type in the final structure is related to the mechanics of formation i.e. mainly central and peripheral. This study provides a unique and generically applicable insight into the dynamics of multicellular spheroid formation where aggregation is induced by one cell type and imposed on another. This has implications for 3D cell culture models and a wide number of currently used stromal co-culture systems.

Comparison of multidimensional flow cytometry with standard morphology for evaluation of early marrow response in pediatric acute lymphoblastic leukemia

PURPOSE

We compared multidimensional flow cytometry (MDF) with morphology in evaluating early marrow response to induction chemotherapy in pediatric ALL.

METHODS

Chemotherapy response was determined by standard morphology or by MDF assessed by residual leukemic cell percentage remaining in the marrow on days 7, 14, and 28 of induction. Bone marrow response was classified as M3 (>25% leukemic blasts) or M1/M2 (< or = 25% leukemic blasts). Multidimensional flow cytometry evaluation was compared with that of standard morphology. Available day-7 and day-14 marrow slides were also reevaluated by a single pathologist without patients' clinical information.

RESULTS

Of 46 day-7 specimens, eight (17%) had discordant MDF and morphologic results (P < 0.001), including six classified as M3 by morphology but were M1/M2 by MDF, and two were classified as M3 by MDF but were M1/M2 by morphology. Of 24 day-14 bone marrow specimens, five (20.5%) were discordant (P < 0.001), including two classified as M3 by morphology but were M1/M2 by MDF, and three were classified as M3 by MDF but were M1/M2 by morphology. Reevaluation of the blinded day-7 and day-14 marrow slides yielded discordance between repeated pathology readings of 11% (P < 0.001) and 6% (P = 0.04), respectively.

CONCLUSION

Our data show significant discordance between the morphologic and MDF evaluation of early marrow response. Early response to therapy is a significant prognostic indicator in pediatric acute lymphoblastic leukemia and is used to alter subsequent treatment; thus, precise assessment of response is important. A larger comparison of MDF with morphology for the evaluation of early response, including correlation with clinical outcome, is warranted.

Differences in repair responses between immature and mature cartilage

Cartilage has a poor reparative capacity although it is unclear as to what extent this may be dependent on age or maturation. In the current study, the cellular responses of chondrocytes to experimental wounding in vitro using embryonic, immature, and mature cartilage have been compared. In all cases, the response was consistent (a combination of cell death that included apoptosis and proliferation). The speed of response varied in terms of cell death with embryonic cartilage showing the most rapid response and mature cartilage showing the slowest response. Intrinsic repair as assessed by the ability to heal the lesion was not detected in any of the culture systems used. It was concluded that the poor repair potential of cartilage is not maturation dependent in the systems studied.

NK cells recover early and mediate cytotoxicity via perforin/granzyme and Fas/FasL pathways in umbilical cord blood recipients

Umbilical cord blood (UCB) is now widely accepted as a source of stem cells in patients with malignant hematologic and genetic disorders. We have recently reported that in a series of 30 pediatric UCB transplant recipients comparable outcome to that anticipated with other unrelated stem cell sources. In our series, however, the probability of GVHD for grade III-IV was 9% and no UCB recipient developed chronic GVHD. The reason for the low incidence of GVHD after UCB transplantation is not fully understood. Because functional NK cells are among the first population of lymphocytes to be detected in UCB transplant recipients, 2 months post-transplant on average, we wanted to establish whether NK cells could be implicated in reducing the risk of GVHD. Here, we confirm that early NK cells detected in UCB transplant recipients activate the granzyme/perforin lytic pathway and, in addition, they can mediate Fas/Fas ligand (FasL) activity, a finding not previously reported. Both pathways develop simultaneously and are detectable months before the other lymphocytes, notably CD8 are fully functional. Our contention, therefore, is that the low GVHD observed in UCB recipients may be partially due to early NK cells.

Histology-specific expression of a DNA repair protein in pediatric rhabdomyosarcomas

PURPOSE

DNA repair enzymes have a critical role in cellular maintenance and survival. The enzyme apurinic/apyrimidinic endonuclease/redox factor 1 (APE/ref1), a key protein in the base excision repair pathway, displays both repair and redox control. We examined the role of APE/ref1 in pediatric embryonal and alveolar rhabdomyosarcomas (ARMS).

MATERIALS AND METHODS

Using an immunohistochemical method, fixed tissue from 31 newly diagnosed pediatric rhabdomyosarcomas were evaluated for expression of APE/ref1. Tissue was obtained from Indiana University and the Cooperative Human Tissue Network.

RESULTS

We demonstrated high levels of expression within the localized and metastatic embryonal rhabdomyosarcomas. This contrasted with both localized and metastatic ARMS, which had low levels of APE/ref1 expression. This histology-specific difference proved to be significant (P = 0.003). Furthermore, the expression within all tumors examined was localized to the nucleus and did not differ between localized and metastatic tumors.

CONCLUSIONS

We propose several hypotheses to explain this histology-specific expression of APE/ref1 in pediatric rhabdomyosarcomas. Because the majority of ARMS expressed either the PAX3/FKHR or PAX7/FKHR fusion transcript, the low level of expression may be related to the redox activity of APE/ref1. The low levels may also be related to the bioreductive activity of APE/ref 1.

T-cell recovery following marrow transplant: experience with delayed lymphocyte infusions to accelerate immune recovery or treat infectious problems

All forms of hematopoietic stem-cell transplantation are complicated by delayed immune reconstitution, which results in an increased risk of infectious complications and relapse of disease. Donor lymphocyte infusions have been used in an attempt to enhance immune recovery and for the prevention and treatment of specific infections following transplantation. While there is little data to support the use of donor lymphocytes for the enhancement of general immune function post-transplant, unselected and virus-specific donor T cells may have efficacy for the prophylaxis and treatment of infections and disease caused by Epstein-Barr virus (EBV) and cytomegalovirus (CMV). While donor lymphocyte infusions may cause significant morbidity and mortality, they are a novel and potentially powerful approach for the treatment of frequently fatal post-transplant infectious complications.

A polymorphism in the regulatory region of the CC-chemokine receptor 5 gene influences perinatal transmission of human immunodeficiency virus type 1 to African-American infants

There are natural mutations in the coding and noncoding regions of the human immunodeficiency virus type 1 (HIV-1) CC-chemokine coreceptor 5 (CCR5) and in the related CCR2 protein (the CCR2-64I mutation). Individuals homozygous for the CCR5-Delta32 allele, which prevents CCR5 expression, strongly resist HIV-1 infection. Several genetic polymorphisms have been identified within the CCR5 5' regulatory region, some of which influence the rate of disease progression in adult AIDS study cohorts. We genotyped 1,442 infants (1,235 uninfected and 207 HIV-1 infected) for five CCR5 and CCR2 polymorphisms: CCR5-59353-T/C, CCR5-59356-C/T CCR5-59402-A/G, CCR5-Delta32, and CCR2-64I. The clinical significance of each genotype was assessed by measuring whether it influenced the rate of perinatal HIV-1 transmission among 667 AZT-untreated mother-infant pairs (554 uninfected and 113 HIV-1 infected). We found that the mutant CCR5-59356-T allele is relatively common in African-Americans (20.6% allele frequency among 552 infants) and rare in Caucasians and Hispanics (3.4 and 5.6% of 174 and 458 infants, respectively; P < 0.001). There were 38 infants homozygous for CCR5-59356-T, of whom 35 were African-Americans. Among the African-American infants in the AZT-untreated group, there was a highly significant increase in HIV-1 transmission to infants with two mutant CCR5-59356-T alleles (47.6% of 21), compared to those with no or one mutant allele (13.4 to 14.1% of 187 and 71, respectively; P < 0.001). The increased relative risk was 5.9 (95% confidence interval, 2.3 to 15.3; P < 0.001). The frequency of the CCR5-59356-T mutation varies between population groups in the United States, a low frequency occurring in Caucasians and a higher frequency occurring in African-Americans. Homozygosity for CCR5-59356-T is strongly associated with an increased rate of perinatal HIV-1 transmission.

RT-PCR evaluation of peripheral blood, bone marrow and peripheral blood stem cells in children and adolescents undergoing VACIME chemotherapy for Ewing's sarcoma and alveolar rhabdomyosarcoma

Peripheral blood stem cell support allows dose intensification of multiple cycle chemotherapy for metastatic tumors, including pediatric sarcomas. The VACIME protocol (vincristine, adriamycin, cyclophosphamide, ifosfamide, mesna and etoposide) utilizes peripheral blood stem cells (PBSC) collected following the treatment cycle as support for subsequent dose- and time-intensive chemotherapy. A critical assumption is that PBSC collected in this manner will be purged of residual tumor cells in vivo. We tested this assumption using sensitive reverse-transcriptase polymerase chain reaction (RT-PCR) to assess the presence of the characteristic translocations of the Ewing's sarcoma family of tumors (ESFT) and alveolar rhabdomyosarcoma (ARMS), t(11;22), and t(2;13), respectively. We used RT-PCR to evaluate 122 samples of peripheral blood (PB), bone marrow (BM) and PBSC collected from 12 pediatric patients with metastatic ESFT and ARMS. The samples included pre-therapy BM and PB, as well as BM, PB, and PBSC collections at various times in the VACIME treatment course. Molecular evidence of tumor contamination was detected in 1/40 PBSC collections from 12 patients. In all patients, we documented clearance of disease by RT-PCR in peripheral blood and bone marrow by week 9 of the VACIME protocol. In vivo purging in combination with the intensive VACIME regime appears to be effective in removing tumor cells from PBSC, bone marrow, and peripheral blood as detected by RT-PCR.

Heterocyclic amine levels in cooked meat and the implication for New Zealanders

This paper was presented to an expert workshop on meat intake and colorectal cancer risk, held in Adelaide, Australia on 4 December 1998, as a contribution to discussion of the possible role of heterocyclic amines (HCAs) in colorectal cancer. HCAs, which are genotoxic and carcinogenic to experimental animals, are formed in fish, meat and meat residues under certain cooking conditions which are relevant to human lifestyle practices. The most important variables contributing to the formation of HCAs are: cooking temperature (>150 degrees C), cooking time (>2 min), cooking method (frying, oven grilling/broiling, barbecuing), and meat type (e.g. sausage < whole meat). Humans will be exposed to HCAs from the consumption of meat or fish cooked by these methods and from the consumption of gravy prepared from pan residues. Approximately one-third of the meat consumed on a daily basis in New Zealand is cooked by methods likely to result in the formation of HCAs. When intake estimates are combined with animal cancer potency data, the greatest contributor to cancer risk is from the consumption of chicken. Red meat is no more implicated than any other meat type. Although the role of HCA in human cancer is yet to be clearly established, exposure can be minimized by lifestyle choices.

Enhanced levels and enhanced clonogenic capacity of blood progenitor cells following administration of stem cell factor plus granulocyte colony-stimulating factor to humans

Administration of hematopoietic growth factors is being used increasingly to obtain populations of blood progenitor/stem cells (PBPC) for clinical transplantation. Here we examined the effect of combining stem cell factor (SCF ) and granulocyte colony-stimulating factor (G-CSF ) versus G-CSF alone in a randomized clinical study involving 62 women with early-stage breast cancer. In the first patient cohorts, escalating doses of SCF were administered for 7 days with concurrent G-CSF administration. At baseline, levels of progenitor cells in the bone marrow or blood were comparable in the different patient groups. As with administration of G-CSF alone, the combination of SCF plus G-CSF did not alter the wide variation in levels of PBPC observed between individuals and did not alter the selective nature of PBPC release, with preferential release of day-14 granulocyte-macrophage colony-stimulating factor (GM-CFC) versus day-7 GM-CFC. However, SCF acted to sustain the levels of PBPC after cessation of growth factor treatment; levels of PBPC were elevated 100-fold at later timepoints compared with G-CSF alone. In addition, the maximum levels of PBPC observed were increased approximately fivefold at day 5 of growth-factor administration. The increased levels of PBPC resulted in significantly increased levels of PBPC obtained by leukapheresis. In a subsequent patient cohort, 3-days pretreatment with SCF was introduced and followed by 7 days concurrent SCF plus G-CSF. The 3-days pretreatment with SCF resulted in an earlier wave of PBPC release in response to commencement of G-CSF. In addition, maximum PBPC levels in blood and PBPC yield in leukapheresis products were further increased. Unexpectedly however, SCF pretreatment resulted in progenitor cells with enhanced self-generation potential. Recloning assays documented the ability of approximately 30% of primary granulocyte-macrophage (GM) colonies from control cell populations to generate secondary GM colonies (n = 1,106 primary colonies examined). In contrast approximately 90% of GM colonies from PBPC after SCF pretreatment generated secondary clones and 65% generated secondary colonies. The action of SCF was not explicable in terms of altered SCF, GM-CSF, or G-CSF responsiveness, but SCF pretreatment was associated with maximum serum SCF levels at the time G-CSF was commenced. These results show that PBPC populations mobilized by different growth factor regimens can differ in their functional properties and caution against solely considering number of harvested progenitor cells without regard to their function.