Deep Learning-Enabled Multiplexed Point-of-Care Sensor using a Paper-Based Fluorescence Vertical Flow Assay.

Multiplexed computational sensing with a point-of-care serodiagnosis assay to simultaneously quantify three biomarkers of acute cardiac injury is demonstrated. This point-of-care sensor includes a paper-based fluorescence vertical flow assay (fxVFA) processed by a low-cost mobile reader, which quantifies the target biomarkers through trained neural networks, all within <15 min of test time using 50 µL of serum sample per patient. This fxVFA platform is validated using human serum samples to quantify three cardiac biomarkers, i.e., myoglobin, creatine kinase-MB, and heart-type fatty acid binding protein, achieving less than 0.52 ng mL-1 limit-of-detection for all three biomarkers with minimal cross-reactivity. Biomarker concentration quantification using the fxVFA that is coupled to neural network-based inference is blindly tested using 46 individually activated cartridges, which shows a high correlation with the ground truth concentrations for all three biomarkers achieving >0.9 linearity and <15% coefficient of variation. The competitive performance of this multiplexed computational fxVFA along with its inexpensive paper-based design and handheld footprint makes it a promising point-of-care sensor platform that can expand access to diagnostics in resource-limited settings.

Poly(dehydroalanine): Synthesis, Properties, and Functional Diversification of a Fluorescent Polypeptide.

Via the design of a new, soluble poly(S-alkyl-l-cysteine) precursor, a route was developed for the successful preparation of long-chain poly(dehydroalanine), ADH, as well as the incorporation of dehydroalanine residues and ADH segments into copolypeptides. Based on experimental and computational data, ADH was found to adopt a previously unobserved "hybrid coil" structure, which combines the elements of 25-helical and 310-helical conformations. Analysis of the spectroscopic properties of ADH revealed that it possesses a strong inherent blue fluorescence, which may be amenable for use in imaging applications. ADH also contains reactive electrophilic groups that allowed its efficient modification to functionalized polypeptides after reactions under mild conditions with thiol and amine nucleophiles. The combined structural, spectroscopic, and reactivity properties of ADH make it a unique reactive and fluorescent polypeptide component for utilization in self-assembled biomaterials.

Rigid versus flexible endoscopy for managing ingested foreign bodies-can we improve pathways?

PURPOSE: This study aims to evaluate management pathways, outcomes and safety of rigid endoscopy (RE) and flexible endoscopy (FE) for the treatment of impacted foreign bodies of the upper gastrointestinal tract (UGIT) in adults. METHODS: Retrospective study, included all patients undergoing RE or FE for impacted UGIT foreign body over an 11-year-period. RESULTS: A total of 144 patients were included (95 FE and 49 RE). FE were performed under local anaesthetic or sedation, and RE under GA. Success rate of FE and RE were 95.8% and 95.9% respectively. During FE an intra-procedural biopsy was performed in 45/95 (47.3%); with 26/95(27.4%) identifying mucosal pathology. Complications was significantly higher in patients having RE (40.8% versus 6.3%, p = .001). CONCLUSION: FE and RE are effective for the therapeutic management of impacted UGIT foreign bodies. However, FE can be performed under LA and was associated with fewer complications, favouring FE where possible as a first line option.

"The Ripple Effect": The influence of social support on participation in a small workplace health promotion program.

ISSUE ADDRESSED: Workplaces are key settings for health promotion. There is limited evidence pertaining to workplace health promotion [WHP] in Australian small and medium enterprises [SMEs], particularly in regional areas. This qualitative study explored employee perceptions of a pilot workplace health promotion program, LifeMAP, conducted in a small health service enterprise in regional Victoria 2014-2017, including facilitators of participation and perceived benefits of participation. METHOD: Ten LifeMAP participants were recruited using convenience sampling. Individual semi-structured interviews (n = 7) and one focus group (n = 3) were conducted between August and September 2017. Data were analysed inductively and thematically to elicit emergent themes. RESULTS: Social support emerged as the overarching theme influencing participation in LifeMAP, and a perceived benefit of participation. Using FitBits® and setting exercise challenges enabled social support to be fostered through role modelling, staff collegiality and community. There may be gendered differences in the experiences of role modelling in WHP. CONCLUSIONS: This SME, and others like it, often feature high levels of employee social connectedness, with a strong workplace and community networks. Social support is a critical influence in social connectedness which needs to be considered and incorporated into the design, implementation and evaluation of WHP programs as a means of overcoming WHP recruitment and participation challenges in regional SMEs. SO WHAT?: The identification of social support as a key factor for WHP participation and employee satisfaction is a valuable finding providing insight into how similar programs may be better designed and implemented to enhance WHP program recruitment and retention.

Active Controlled and Tunable Coacervation Using Side-Chain Functional α-Helical Homopolypeptides.

We report the development of new side-chain amino acid-functionalized α-helical homopolypeptides that reversibly form coacervate phases in aqueous media. The designed multifunctional nature of the side-chains was found to provide a means to actively control coacervation via mild, biomimetic redox chemistry as well as allow response to physiologically relevant environmental changes in pH, temperature, and counterions. These homopolypeptides were found to possess properties that mimic many of those observed in natural coacervate forming intrinsically disordered proteins. Despite ordered α-helical conformations that are thought to disfavor coacervation, molecular dynamics simulations of a polypeptide model revealed a high degree of side-chain conformational disorder and hydration around the ordered backbone, which may explain the ability of these polypeptides to form coacervates. Overall, the modular design, uniform nature, and ordered chain conformations of these polypeptides were found to provide a well-defined platform for deconvolution of molecular elements that influence biopolymer coacervation and tuning of coacervate properties for downstream applications.

Computerized Electronic Order Set: Use and Outcomes for Heart Failure Following Hospitalization.

BACKGROUND: Quality improvement initiatives improve health care delivery but may be resource intensive and disrupt clinical care. An embedded heart failure order set (HFOS) within a computerized physician order-entry system may mitigate these concerns. METHODS: An HFOS, based on proven interventions, was implemented within an existing computerized physician order-entry system in all adult acute-care hospitals in a single Canadian metropolitan city and interrogated between January 1, 2013 and December 31, 2015. The composite of repeat hospitalization or death within 30 days of hospital discharge and hospital length of stay were reported. RESULTS: In total, 8969 patients were included with mean age 75.6 ± 13.5 years; 4673 (52.1%) were male. The HFOS was used in 731 (8.2%) patients. After analysis of 724 pairs of propensity-score matched cohorts, patients with HFOS use experienced a lower median length of stay (8.6 vs 9.4 days, P = 0.016) and a trend toward lower composite repeat hospitalization or death (14.5% vs 17.7%, P = 0.115, hazard ratio 0.79 (0.60-1.05). Patients with HFOS use were more likely to undergo a test for left ventricular ejection fraction (88.6% vs 76.7%, P < 0.001, and to be referred to a heart failure clinic (48.5% vs 6.3%), with similar rates of discharge prescription of beta-blockers (88.7% vs 86.3) and angiotensin-converting enzyme inhibitors (87.4% vs 89.0%). CONCLUSIONS: Use of a designated HFOS within a computerized physician order-entry system is associated with shorter hospital length of stay without increase in deaths or readmissions. These findings should be confirmed in a prospective controlled trial.

CONTEXTE: Les initiatives visant à l'amélioration de la qualité favorisent la prestation des soins de santé, mais elles peuvent nécessiter beaucoup de ressources et perturber les soins cliniques. Un ensemble d'ordonnances relatives à l'insuffisance cardiaque (HFOS pour heart failure order set) intégré dans un système informatisé de saisie des ordonnances des médecins pourrait atténuer ces préoccupations. MÉTHODES: Un HFOS, basé sur des interventions éprouvées, a été mis en place au sein d'un système informatisé de saisie d'ordonnances médicales existant dans tous les hôpitaux de soins actifs pour adultes d'une même métropole canadienne et a été interrogé entre le 1er janvier 2013 et le 31 décembre 2015. Les données combinées de réadmission ou de décès pour les 30 jours suivant la sortie de l'hôpital et la durée du séjour à l'hôpital ont été répertoriées. RÉSULTATS: Au total, 8 969 patients ont été inclus avec un âge moyen de 75,6 ± 13,5 ans ; 4 673 (52,1 %) étaient des hommes. Le HFOS a été utilisé pour 731 (8,2 %) patients. Après analyse de 724 paires de cohortes appariées par score de propension, les patients associés à l'usage du HFOS ont connu une durée médiane de séjour hospitalier plus faible (8,6 contre 9,4 jours, p = 0.016) et une tendance combinée de réadmission ou de décès plus faible (14,5 % contre 17,7 %, p = 0,115, rapport de risque 0,79 (0,60-1,05). Les patients associés à l'usage du HFOS étaient plus susceptibles de subir un examen pour mesurer leur fraction d'éjection ventriculaire gauche (88,6 % contre 76,7 %, p < 0,001, et d'être orientés vers une clinique d'insuffisance cardiaque (48,5 % contre 6,3 %), avec des taux similaires de prescription à la sortie de bêta-bloquants (88,7 % contre 86,3 %) et d'inhibiteurs de l'enzyme de conversion de l'angiotensine (87,4 % contre 89,0 %). CONCLUSIONS: L'utilisation d'un HFOS particulier dans un système informatisé de saisie d'ordonnances médicales est associée à une réduction de la durée du séjour hospitalier sans augmentation des décès ou des réadmissions. Ces résultats devraient être confirmés dans le cadre d'un essai comparatif prospectif.

Mental models of adherence: parallels in perceptions, values, and expectations in adherence to prescribed home exercise programs and other personal regimens.

Purpose: A mental model is the collection of an individual's perceptions, values, and expectations about a particular aspect of their life, which strongly influences behaviors. This study explored orthopedic outpatients mental models of adherence to prescribed home exercise programs and how they related to mental models of adherence to other types of personal regimens. Methods: The study followed an interpretive description qualitative design. Data were collected via two semi-structured interviews. Interview One focused on participants prior experiences adhering to personal regimens. Interview Two focused on experiences adhering to their current prescribed home exercise program. Data analysis followed a constant comparative method. Results: Findings revealed similarity in perceptions, values, and expectations that informed individuals mental models of adherence to personal regimens and prescribed home exercise programs. Perceived realized results, expected results, perceived social supports, and value of convenience characterized mental models of adherence. Conclusion: Parallels between mental models of adherence for prescribed home exercise and other personal regimens suggest that patients adherence behavior to prescribed routines may be influenced by adherence experiences in other aspects of their lives. By gaining insight into patients adherence experiences, values, and expectations across life domains, clinicians may tailor supports that enhance home exercise adherence. Implications for Rehabilitation A mental model is the collection of an individual's perceptions, values, and expectations about a particular aspect of their life, which is based on prior experiences and strongly influences behaviors. This study demonstrated similarity in orthopedic outpatients mental models of adherence to prescribed home exercise programs and adherence to personal regimens in other aspects of their lives. Physical therapists should inquire about patients non-medical adherence experiences, as strategies patients customarily use to adhere to other activities may inform strategies to promote prescribed home exercise adherence.

Ten-year assessment of the 100 priority questions for global biodiversity conservation.

In 2008, a group of conservation scientists compiled a list of 100 priority questions for the conservation of the world's biodiversity. However, now almost a decade later, no one has yet published a study gauging how much progress has been made in addressing these 100 high-priority questions in the peer-reviewed literature. We took a first step toward reexamining the 100 questions to identify key knowledge gaps that remain. Through a combination of a questionnaire and a literature review, we evaluated each question on the basis of 2 criteria: relevance and effort. We defined highly relevant questions as those that - if answered - would have the greatest impact on global biodiversity conservation and quantified effort based on the number of review publications addressing a particular question, which we used as a proxy for research effort. Using this approach, we identified a set of questions that, despite being perceived as highly relevant, have been the focus of relatively few review publications over the past 10 years. These questions covered a broad range of topics but predominantly tackled 3 major themes: conservation and management of freshwater ecosystems, role of societal structures in shaping interactions between people and the environment, and impacts of conservation interventions. We believe these questions represent important knowledge gaps that have received insufficient attention and may need to be prioritized in future research.

Impact of a Pediatric Cardiology Clinical Program on Congenital Heart Disease Outcomes in Guyana.

Background: Children with congenital heart disease (CHD) in Guyana have not historically been managed with timely intervention, increasing the likelihood of serious, irreversible complications. In 2014, a pediatric cardiology clinical program (Guyana Paediatric Cardiology Steering Committee [GPCSC]) and partnership with International Children's Heart Foundation (BabyHeart) was developed to improve CHD care. Objectives: To describe the characteristics of CHD in Guyanese children and to determine the impact of GPCSC on CHD outcomes. Methods: Qualitative comparison between CHD patients sent for surgery prior to GPCSC (pre-GPCSC cohort) and those managed through GPCSC (post-GPCSC cohort). Findings: Eighty-eight pre-GPHC patients were identified from 2005 to 2014. A total of 319 CHD patients were referred post-GPCSC. In all, 114 patients required surgical or catheterization procedures, with 74 patients prioritized for interventions within 29 months post-GPCSC. Mean age at surgery was 77 months in both cohorts, with younger children represented in the post-GPCSC cohort. Postoperative follow-up was more frequent post-GPCSC (100% vs 35%). Vital status of 48% of pre-GPCSC patients is unknown, with more pre-GPCSC patients known to be deceased compared with post-GPCSC (9% vs 5%). Pre-GPCSC patients had more incorrect diagnosis and inoperable disease when sent for surgery. Interpretation: Patients undergoing surgery post-GPCSC had more appropriate and timely interventions, better follow-up, and increased survival. The feasibility and positive impact of this collaborative pediatric cardiology clinical program in Guyana is demonstrated, with potential applicability for other low- and middle-income countries. Obstacles to referral of children with CHD in Guyana can begin to be addressed, with the goal of more complete access to timely intervention, and improved outcomes for these children.

Bio-methane from an-aerobic digestion using activated carbon adsorption.

There is an increasing global demand for carbon-neutral bio-methane from an-aerobic digestion (AD) to be injected into national gas grids. Bio-gas, a methane -rich energy gas, is produced by microbial decomposition of organic matter through an-aerobic conditions where the presence of carbon dioxide and hydrogen sulphide affects its performance. Although the microbiological process in the AD can be tailored to enhance the bio-gas composition, physical treatment is needed to convert the bio-gas into bio-methane. Water washing is the most common method for upgrading bio-gas for bio-methane production, but its large use of water is challenging towards industrial scale-up. Hence, the present study focuses on scale-up comparison of water washing with activated-carbon adsorption using HYSYS and Aspen Process Economic Analyzer. The models show that for plants processing less than 500 m3/h water scrubbing was cost effective compared with activated carbon. However, against current fossil natural-gas cost of about 1 p/kWh in the UK both relied heavily on governmental subsidies to become economically feasible. For plants operating at 1000 m3/hr, the treatment costs were reduced to below 1.5 p/kWh for water scrubbing and 0.9 p/kWh for activated carbon where the main benefits of activated carbon were lower capital and operating costs and virtually no water losses. It is envisioned that this method can significantly aid the production of sustainable bio-methane.

The role of analogy-guided learning experiences in enhancing students' clinical decision-making skills.

The purpose of this study was to address the need for effective educational interventions to promote students' clinical decision making (CDM) within clinical practice environments. Researchers used a quasi-experimental, non-equivalent groups, posttest-only design to assess differences in CDM ability between intervention group students who participated in analogy-guided learning activities and control group students who participated in traditional activities. For the intervention, analogy-guided learning activities were incorporated into weekly group discussions, reflective journal writing, and questioning with clinical faculty. The researcher-designed Assessment of Clinical Decision Making Rubric was used to assess indicators of CDM ability in all students' reflective journal entries. Results indicated that the intervention group demonstrated significantly higher levels of CDM ability in their journals compared with the control group (ES(sm) = 0.52). Recommendations provide nurse educators with strategies to maximize students' development of CDM ability, better preparing students for the demands they face when they enter the profession.

Eicosanoid formation by a cytochrome P450 isoform expressed in the pharynx of Caenorhabditis elegans.

Caenorhabditis elegans harbours several CYP (cytochrome P450) genes that are homologous with mammalian CYP isoforms important to the production of physiologically active AA (arachidonic acid) metabolites. We tested the hypothesis that mammals and C. elegans may share similar basic mechanisms of CYP-dependent eicosanoid formation and action. We focused on CYP33E2, an isoform related to the human AA-epoxygenases CYP2C8 and CYP2J2. Co-expression of CYP33E2 with the human NADPH-CYP reductase in insect cells resulted in the reconstitution of an active microsomal mono-oxygenase system that metabolized EPA (eicosapentaenoic acid) and, with lower activity, also AA to specific sets of regioisomeric epoxy- and hydroxy-derivatives. The main products included 17,18-epoxyeicosatetraenoic acid from EPA and 19-hydroxyeicosatetraenoic acid from AA. Using nematode worms carrying a pCYP33E2::GFP reporter construct, we found that CYP33E2 is exclusively expressed in the pharynx, where it is predominantly localized in the marginal cells. RNAi (RNA interference)-mediated CYP33E2 expression silencing as well as treatments with inhibitors of mammalian AA-metabolizing CYP enzymes, significantly reduced the pharyngeal pumping frequency of adult C. elegans. These results demonstrate that EPA and AA are efficient CYP33E2 substrates and suggest that CYP-eicosanoids, influencing in mammals the contractility of cardiomyocytes and vascular smooth muscle cells, may function in C. elegans as regulators of the pharyngeal pumping activity.

Loss of reelin expression in breast cancer is epigenetically controlled and associated with poor prognosis.

Reelin is a secreted, signaling protein associated with neuronal cell positioning and migration. Recently, reelin was found to be epigenetically silenced in gastric and pancreatic cancers in which down-regulation was associated with increased migratory ability and reduced survival. Here we analyzed reelin expression by immunohistochemistry in 17 normal breast tissue samples from reduction mammoplasties and in two independent tissue microarrays of 136 and more than 2000 breast cancer biopsy samples, respectively. Results were analyzed with regard to clinical parameters, including BRE (Bloom, Richardson, Elston) grade, nodal status, estrogen receptor and HER2 status, and overall survival. Reelin was expressed in the luminal epithelium and myoepithelium of the normal human breast but not in cancerous breasts. Loss of reelin protein expression correlated significantly with decreased survival (P=0.01) and positive lymph node status (P<0.001). By measuring reelin expression and promoter methylation status in 39 primary breast tumors, as well as in breast cancer-derived cell lines before and after decitabine treatment, we established that reelin expression levels correlated inversely with promoter methylation status, whereas demethylation increased reelin mRNA expression in vitro. Reelin overexpression in MDA-MB231 cells, as well as incubation with recombinant reelin, suppressed cell migration, invadopodia formation, and invasiveness in vitro. We conclude that reelin may play an important role in controlling invasiveness and metastatic potential of breast cancer cells and that its expression is controlled by promoter methylation.

Effect of oxalate test dose size on absolute and percent oxalate absorption.

The purpose of this pilot study was to establish the dependence or independence of oxalate absorption on the quantity of the test dose of sodium oxalate over a range of test doses corresponding to physiological dietary oxalate intake values. Gastrointestinal oxalate absorption was measured with the [13C2]oxalate absorption test. Six healthy volunteers were always tested under standardized dietary conditions with 63 mg dietary oxalate and 800 mg dietary calcium per day. The volunteers were tested thrice each with sodium oxalate test doses of 25, 50, 200, and 600 mg. Additionally, 1000 mg sodium oxalate was applied once to three of these volunteers. The oxalate absorption of the six volunteers tested under the standardized conditions with 50 mg sodium [13C2]oxalate was 7.2 +/- 2.62 % (mean +/- SD), similar to the 120 volunteers tested previously: 8.0 +/- 4.4 % (mean +/- SD). The tests with sodium [13C2]oxalate doses in the range 25-1000 mg revealed similar percent oxalate absorption values. In conclusion, in healthy volunteers, the amount of oxalate absorbed in the gastrointestinal tract increased proportionally with the higher test doses of oxalate. However, percent oxalate absorption remained unchanged with test doses in the dose range of physiological dietary oxalate intakes.

Involvement of axonal guidance proteins and their signaling partners in the developing mouse mammary gland.

Mammary morphogenesis in the mouse is driven by specialized structures at the ends of the developing ducts, the terminal end buds (TEB). The mechanisms controlling the precise branching and spacing of the ducts are, as yet, unknown. To identify genes that are associated with migration of TEB and differentiation of the subtending ducts, we developed a novel method of isolating TEB and ducts free of stroma, and compared the gene expression profiles of these two isolates using oligonucleotide microarrays. Ninety one genes were upregulated in TEB compared to ducts. Three of these genes, Sprr1A, Sema3B, and BASP1, are associated with axonal growth and guidance. Two additional members of the Sprr family, Sprr2A and 2B, not previously associated with axonal growth, were also highly expressed in TEB. Expression of these genes was confirmed by RT-PCR and Western blotting, and the cellular distribution of Sprr1A and BASP1 was demonstrated by immunohistochemistry. Other semaphorins, including Sema3C, 4A, 4F and the cancer invasion associated Sema 4D were also expressed in the mouse mammary gland along with the semaphorin receptors, Plexins A2, A3, B2, and D1, and Neuropilins 1 and 2. These results are discussed in the context of other proteins expressed in the developing gland that are known to be downstream effectors of these signaling molecules. We suggest that these genes may influence ductal growth and morphogenesis in the developing mammary gland.

Annexin A8 is up-regulated during mouse mammary gland involution and predicts poor survival in breast cancer.

PURPOSE: Microarray studies have linked Annexin A8 RNA expression to a "basal cell-like" subset of breast cancers, including BRCA1-related cancers, that are characterized by cytokeratin 5 (CK5) and CK17 expression and show poor prognosis. We assessed Annexin A8's contribution to the overall prognosis and its expression in normal, benign, and cancerous tissue and addressed Annexin A8's physiologic role in the mammary gland. EXPERIMENTAL DESIGN: Using microarrays and reverse transcription-PCR, the Annexin A8 expression was studied during mouse mammary gland development and in isolated mammary structures. Reverse transcription-PCR on cultured human luminal and basal cells, along with immunocytochemistry on normal and benign breast tissues, was used for cellular localization. Annexin A8's prognostic relevance and its coexpression with CK5 were assessed on tissue arrays of 1,631 cases of invasive breast cancer. Coexpression was further evaluated on a small cohort of 14 BRCA1-related breast cancers. RESULTS: Annexin A8 was up-regulated during mouse mammary gland involution and in pubertal ductal epithelium. Annexin A8 showed preferred expression in cultured basal cells but predominant luminal expression in normal human breast tissue in vivo. Hyperplasias and in situ carcinomas showed a strong staining of basal cells. Annexin A8 expression was significantly associated with grade (P < 0.0001), CK5 (P < 0.0001), and estrogen receptor status (P < 0.0001); 85.7% BRCA1-related breast tumors coexpressed Annexin A8 and CK5. CONCLUSION: Annexin A8 is involved in mouse mammary gland involution. In humans, it is a luminally expressed protein with basal expression in cell culture and in hyperplasia/ductal carcinoma in situ. Expression in invasive breast carcinomas has a significant effect on survival (P = 0.03) but is not independent of grade or CK5.

Markers of adenocarcinoma characteristic of the site of origin: development of a diagnostic algorithm.

PURPOSE: Patients with metastatic adenocarcinoma of unknown origin are a common clinical problem. Knowledge of the primary site is important for their management, but histologically, such tumors appear similar. Better diagnostic markers are needed to enable the assignment of metastases to likely sites of origin on pathologic samples. EXPERIMENTAL DESIGN: Expression profiling of 27 candidate markers was done using tissue microarrays and immunohistochemistry. In the first (training) round, we studied 352 primary adenocarcinomas, from seven main sites (breast, colon, lung, ovary, pancreas, prostate and stomach) and their differential diagnoses. Data were analyzed in Microsoft Access and the Rosetta system, and used to develop a classification scheme. In the second (validation) round, we studied 100 primary adenocarcinomas and 30 paired metastases. RESULTS: In the first round, we generated expression profiles for all 27 candidate markers in each of the seven main primary sites. Data analysis led to a simplified diagnostic panel and decision tree containing 10 markers only: CA125, CDX2, cytokeratins 7 and 20, estrogen receptor, gross cystic disease fluid protein 15, lysozyme, mesothelin, prostate-specific antigen, and thyroid transcription factor 1. Applying the panel and tree to the original data provided correct classification in 88%. The 10 markers and diagnostic algorithm were then tested in a second, independent, set of primary and metastatic tumors and again 88% were correctly classified. CONCLUSIONS: This classification scheme should enable better prediction on biopsy material of the primary site in patients with metastatic adenocarcinoma of unknown origin, leading to improved management and therapy.

Involution of the mouse mammary gland is associated with an immune cascade and an acute-phase response, involving LBP, CD14 and STAT3.

INTRODUCTION: Involution of the mammary gland is a complex process of controlled apoptosis and tissue remodelling. The aim of the project was to identify genes that are specifically involved in this process. METHODS: We used Affymetrix oligonucleotide microarrays to perform a detailed transcript analysis on the mechanism of controlled involution after withdrawal of the pups at day seven of lactation. Some of the results were confirmed by semi-quantitative reverse transcriptase polymerase chain reaction, Western blotting or immunohistochemistry. RESULTS: We identified 145 genes that were specifically upregulated during the first 4 days of involution; of these, 49 encoded immunoglobulin genes. A further 12 genes, including those encoding the signal transducer and activator of transcription 3 (STAT3), the lipopolysaccharide receptor (CD14) and lipopolysaccharide-binding protein (LBP), were involved in the acute-phase response, demonstrating that the expression of acute-phase response genes can occur in the mammary gland itself and not only in the liver. Expression of LBP and CD14 was upregulated, at both the RNA and protein level, immediately after pup withdrawal; CD14 was strongly expressed in the luminal epithelial cells. Other genes identified suggested neutrophil activation early in involution, followed by macrophage activation late in the process. Immunohistochemistry and histological staining confirmed the infiltration of the involuting mammary tissue with neutrophils, plasma cells, macrophages and eosinophils. CONCLUSION: Oligonucleotide microarrays are a useful tool for identifying genes that are involved in the complex developmental process of mammary gland involution. The genes identified are consistent with an immune cascade, with an early acute-phase response that occurs in the mammary gland itself and resembles a wound healing process.

p53 polymorphism influences response in cancer chemotherapy via modulation of p73-dependent apoptosis.

Intact p73 function is shown to be an important determinant of cellular sensitivity to anticancer agents. Inhibition of p73 function by dominant-negative proteins or by mutant p53 abrogates apoptosis and cytotoxicity induced by these agents. A polymorphism encoding either arginine (72R) or proline (72P) at codon 72 of p53 influences inhibition of p73 by a range of p53 mutants identified in squamous cancers. Clinical response following cisplatin-based chemo-radiotherapy for advanced head and neck cancer is influenced by this polymorphism, cancers expressing 72R mutants having lower response rates than those expressing 72P mutants. Polymorphism in p53 may influence individual responsiveness to cancer therapy.