Duplex-forming oligocarbamates with tunable nonbonding sites.

In biopolymers such as proteins and nucleic acids, monomer sequence encodes for highly specific intra- and intermolecular interactions that direct self-assembly into complex architectures with high fidelity. This remarkable structural control translates into precise control over the properties of the biopolymer. Polymer scientists have sought to achieve similarly precise control over the structure and function of synthetic assemblies. A common strategy for achieving this goal has been to exploit existing biopolymers, known to associate with specific geometries and stoichiometries, for the assembly of synthetic building blocks. However, such systems are neither scalable nor amenable to the relatively harsh conditions required by various materials science applications, particularly those involving non-aqueous environments. To overcome these limitations, we have synthesized sequence-defined oligocarbamates (SeDOCs) that assemble into duplexes through complementary hydrogen bonds between thymine (T) and diaminotriazine (D) pendant groups. The SeDOC platform makes it simple to incorporate non-hydrogen-bonding sites into an oligomer's array of recognition motifs, thereby enabling an investigation into this unexplored handle for controlling the hybridization of complementary ligands. We successfully synthesized monovalent, divalent, and trivalent SeDOCs and characterized their self-assembly via diffusion ordered spectroscopy, 1H-NMR titration, and isothermal titration calorimetry. Our findings reveal that the binding strength of monovalent oligomers with complementary pendant groups is entropically driven and independent of monomer sequence. The results further show that the hybridization of multivalent oligomers is cooperative, that their binding enthalpy (ΔH) and entropy (TΔS) depend on monomer sequence, and that sequence-dependent changes in ΔH and TΔS occur in tandem to minimize the overall change in binding free energy.

Synthetically encoded complementary oligomers.

Creating the next generation of advanced materials will require controlling molecular architecture to a degree typically achieved only in biopolymers. Sequence-defined polymers take inspiration from biology by using chain length and monomer sequence as handles for tuning structure and function. These sequence-defined polymers can assemble into discrete structures, such as molecular duplexes, via reversible interactions between functional groups. Selectivity can be attained by tuning the monomer sequence, thereby creating the need for chemical platforms that can produce sequence-defined polymers at scale. Developing sequence-defined polymers that are specific for their complementary sequence and achieve their desired binding strengths is critical for producing increasingly complex structures for new functional materials. In this Review Article, we discuss synthetic platforms that produce sequence-defined, duplex-forming oligomers of varying length, strength and association mode, and highlight several analytical techniques used to characterize their hybridization.

A mixed-methods study on evaluating an updated, francophone version of ETAT+ training in Madagascar.

Background: Madagascar needs major efforts to achieve the UN Sustainable Development Goals, despite the considerable reduction of child mortality during past years. In this context, implementation of emergency triage assessment and treatment (ETAT) plays an important role. In recent years, ETAT training activities rarely took place in Madagascar. To strengthen ETAT in Madagascar, a pilot training course was conducted in December 2019 at the University Hospital Mahajanga. Objectives: This study aims to evaluate if the ETAT+ pilot training content matches clinical needs in Madagascar and whether participants achieved their learning objectives. Methods: In this cross-sectional mixed-methods study, a 41-item questionnaire was used at the end of the ETAT+ training to evaluate their learning experience from the 12 participants (paediatricians, physicians, nurses and midwives). Six weeks after the training, guided interviews were conducted among five participants to describe how training content could be transferred into clinical practice in five health facilities. Results: Results suggest that this pilot project designed to contribute to the re-establishment of ETAT in Madagascar meets participants' needs and is adapted to clinical realities in terms of transmitted knowledge, skills and competencies. However, results also show that considerable multi-disciplinary efforts are needed to advance ETAT+ implementation in Madagascar. Conclusion: Implementation processes of ETAT training programmes need re-evaluation to assure their validity to contribute to quality of care improvements efficiently. Further operational research is required to evaluate sustainable, innovative implementation strategies adapted to contexts in Madagascar. Contributions of the study: This study aims to evaluate an updated Malagasy version of the Emergency Triage Assessment and Treatment Plus (ETAT+). The training met the participants' needs and was adapted to the clinical realities in Madagascar relating to transmitted knowledge, skills and competencies.

A novel HER2 gene body enhancer contributes to HER2 expression.

The transcriptional regulation of the human epidermal growth factor receptor-2 (HER2) contributes to an enhanced HER2 expression in HER2-positive breast cancers with HER2 gene amplification and HER2-low or HER2-negative breast cancers following radiotherapy or endocrine therapy, and this drives tumorigenesis and the resistance to therapy. Epigenetic mechanisms are critical for transcription regulation, however, such mechanisms in the transcription regulation of HER2 are limited to the involvement of tri-methylated histone 3 lysine 4 (H3K4me3) and acetylated histone 3 lysine 9 (H3K9ac) at the HER2 promoter region. Here, we report the identification of a novel enhancer in the HER2 3' gene body, which we have termed HER2 gene body enhancer (HGE). The HGE starts from the 3' end of intron 19 and extends into intron 22, possesses enhancer histone modification marks in specific cells and enhances the transcriptional activity of the HER2 promoters. We also found that TFAP2C, a known regulator of HER2, binds to HGE and is required for its enhancer function and that DNA methylation in the HGE region inhibits the histone modifications characterizing enhancer and is inversely correlated with HER2 expression in breast cancer samples. The identification of this novel enhancer sheds a light on the roles of epigenetic mechanisms in HER2 transcription, in both HER2-positive breast cancer samples and individuals with HER2-low or HER2-negative breast cancers undergoing radiotherapy or endocrine therapy.

Extracellular matrix 1 (ECM1) regulates the actin cytoskeletal architecture of aggressive breast cancer cells in part via S100A4 and Rho-family GTPases.

ECM1 overexpression is an independent predictor of poor prognosis in primary breast carcinomas, however the mechanisms by which ECM1 affects tumor progression have not been completely elucidated. ECM1 was silenced in the triple-negative breast cancer cell lines Hs578T and MDAMB231 using siRNA and the cells were evaluated for changes in morphology, migration, invasion and adhesion. Actin cytoskeleton alterations were evaluated by fluorescent staining and levels of activated Rho GTPases by pull down assays. ECM1 downregulation led to significantly diminished cell migration (p = 0.0005 for Hs578T and p = 0.02 for MDAMB231) and cell adhesion (p < 0.001 for Hs578T and p = 0.01 for MDAMB231). Cell invasion (matrigel) was reduced only in the Hs578T cells (p < 0.01). Silencing decreased the expression of the prometastatic molecules S100A4 and TGFßR2 in both cell lines and CD44 in Hs578T cells. ECM1-silenced cells also exhibited alterations in cell shape and showed bundles of F-actin across the cell (stress fibers) whereas NT-siRNA treated cells showed peripheral membrane ruffling. Downregulation of ECM1 was also associated with an increased F/G actin ratio, when compared to the cells transfected with NT siRNA (p < 0.001 for Hs578T and p < 0.00035 for MDAMB231) and a concomitant decline of activated Rho A in the Hs578T cells. Re-expression of S100A4 in ECM1-silenced cells rescued the phenotype in the Hs578T cells but not the MDAMB231 cells. We conclude that ECM1 is a key player in the metastatic process and regulates the actin cytoskeletal architecture of aggressive breast cancer cells at least in part via alterations in S100A4 and Rho A.

Entry characteristics and performance in a Masters module in Tropical Medicine: a 5-year analysis.

OBJECTIVES: Postgraduate courses can contribute to better-qualified personnel in resource-limited settings. We aimed to identify how entry characteristics of applicants predict performance in order to provide support measures early. METHODS: We describe demographic data and end-of-module examination marks of medical doctors who enrolled in a first semester module of two one-year MSc programmes between 2010 and 2014. We used t-tests and one-way anova to compare, and post hoc tests to locate differences of mean marks between categories of entry characteristics in univariate analysis. After exclusion of collinear variables, multiple regression examined the effect of several characteristics in multivariable analysis. RESULTS: Eighty-nine students (47% male) with a mean age of 32 (SD 6.4) years who received their medical degree in the UK (19%), other European (22%), African (35%) or other countries (24%) attended the 3-months module. Their mean mark was 69.1% (SD 10.9). Medical graduates from UK universities achieved significantly higher mean marks than graduates from other countries. Students' age was significantly negatively correlated with the module mark. In multiple linear regression, place of medical degree (ß = -0.44, P < 0.001) and time since graduation (ß = -0.28, P = 0.007) were strongest predictors of performance, explaining 32% of the variation of mean marks. CONCLUSION: Students' performance substantially differs based on their entry criteria in this 1st semester module. Non-UK graduates and mature students might benefit from early support.

The role of Tcfap2c in tumorigenesis and cancer growth in an activated Neu model of mammary carcinogenesis.

TFAP2C/AP-2γ influences development of the mammary gland and regulates patterns of gene expression in luminal and HER2-amplified breast cancer. The roles of TFAP2C in mammary gland tumorigenesis and in pathways critical to cancer progression remain poorly understood. To gain greater insight into oncogenic mechanisms regulated by TFAP2C, we examined mammary tumorigenesis in MMTV-Neu transgenic female mice with or without conditional knockout (KO) of Tcfap2c, the mouse homolog of TFAP2C. Loss of Tcfap2c increased the latency of tumorigenesis and tumors that formed demonstrated reduced proliferative index and increased apoptosis. In addition, tumors formed in Tcfap2c KO animals had a significant reduction in Egfr levels without a change in the expression of the Neu oncogene. The MMneu-flAP2C cell line was established from tumor tissue derived from MMTV-Neu/Tcfap2c(L/L) control animals and parallel cell lines with and without expression of Tcfap2c were created by transduction with adenovirus-empty and adenovirus-Cre, respectively. KO of Tcfap2c in vitro reduced activated phosphorylated-Erk, decreased cell viability, repressed tumor growth and was associated with attenuation of Egfr expression. Chromatin immunoprecipitation and direct sequencing and expression analysis confirmed that Egfr was a Tcfap2c target gene in murine, as well as human, mammary carcinoma cells. Furthermore, decreased viability of mammary cancer cells was directly related to Egfr functional blockade. We conclude that TFAP2C regulates tumorigenesis, cell growth and survival in HER2-amplified breast cancer through transcriptional regulation of EGFR. The findings have important implications for targeting the EGFR pathway in breast cancer.

TFAP2C governs the luminal epithelial phenotype in mammary development and carcinogenesis.

Molecular subtypes of breast cancer are characterized by distinct patterns of gene expression that are predictive of outcome and response to therapy. The luminal breast cancer subtypes are defined by the expression of estrogen receptor-alpha (ERα)-associated genes, many of which are directly responsive to the transcription factor activator protein 2C (TFAP2C). TFAP2C participates in a gene regulatory network controlling cell growth and differentiation during ectodermal development and regulating ESR1/ERα and other luminal cell-associated genes in breast cancer. TFAP2C has been established as a prognostic factor in human breast cancer, however, its role in the establishment and maintenance of the luminal cell phenotype during carcinogenesis and mammary gland development have remained elusive. Herein, we demonstrate a critical role for TFAP2C in maintaining the luminal phenotype in human breast cancer and in influencing the luminal cell phenotype during normal mammary development. Knockdown of TFAP2C in luminal breast carcinoma cells induced epithelial-mesenchymal transition with morphological and phenotypic changes characterized by a loss of luminal-associated gene expression and a concomitant gain of basal-associated gene expression. Conditional knockout of the mouse homolog of TFAP2C, Tcfap2c, in mouse mammary epithelium driven by MMTV-Cre promoted aberrant growth of the mammary tree leading to a reduction in the CD24(hi)/CD49f(mid) luminal cell population and concomitant gain of the CD24(mid)/CD49f(hi) basal cell population at maturity. Our results establish TFAP2C as a key transcriptional regulator for maintaining the luminal phenotype in human breast carcinoma. Furthermore, Tcfap2c influences development of the luminal cell type during mammary development. The data suggest that TFAP2C has an important role in regulated luminal-specific genes and may be a viable therapeutic target in breast cancer.

Oxidative profiles of endurance horses racing different distances / Perfil oxidativo em cavalos de enduro competindo em diferentes distâncias

Increased oxidative stress during prolonged endurance exercises may result in muscle damage, fatigue and decreased performance. An adequate stress response during training is critical to obtain improved results and high animal welfare standards. The aim of this study was to evaluate the red blood cell haemolysate concentrations of superoxide dismutase (SOD), glutathione peroxidase (GPx), reduced glutathione (GSH) and catalase (CAT) and the plasma concentrations of malondialdehyde (MDA) from endurance horses in different distances at high speed in a tropical climate. Fifteen horses were tested; five at 160km (18.54 - 17.16km/h race speed), five at 120km (21.53 - 17km/h race speed) and five at 80km (20.06 - 18.01km/h race speed). Blood samples were collected at rest, immediately after and three hours after the horses left the final vet check and three, seven and fourteen days after the race. No significant increases (P > 0.05) in the levels of SOD, GPx, GSH, CAT or MDA were observed for any of the times or distances examined. Based on these observations, we conclude that reactive oxygen species (ROS) formation during exercise evokes specific adaptations, such as increased antioxidant/oxidative damage-repairing enzyme activity, increased resistance to oxidative stress and lower levels of oxidative damage...

Aumento do estresse oxidativo durante o exercício prolongado pode resultar em fadiga muscular, lesões e diminuição do desempenho. Uma adequada resposta a esse estresse durante o treinamento é fundamental para a obtenção de melhores resultados e bem-estar dos animais. O objetivo deste estudo foi avaliar a concentração de superóxido dismutase (SOD), glutationa peroxidase (GPx), glutationa reduzida (GSH) e catalase (CAT) no hemolisado sanguíneo e malondialdeído (MDA) plasmático em cavalos de enduro correndo em diferentes distâncias, com alta média de velocidade, em clima tropical. Quinze cavalos foram testados, cinco em 160km (18.54-17.16km/h), cinco em 120km (21.53-17km/h) e cinco em 80km (20.06-18.01km/h). Amostras de sangue foram coletadas em repouso, imediatamente e três horas depois que os cavalos passaram pela inspeção veterinária final e três, sete e 14 dias após a corrida. Não houve aumentos significativos (P>0,05) dos níveis de SOD, GPx, GSH, CAT ou MDA em nenhum tempo nem distâncias analisadas. Com base nessas observações, pode-se concluir que as espécies reativas de oxigênio (ROS) formadas durante o exercício provocam adaptações específicas, tais como atividade antioxidante aumentada da enzima, maior resistência ao estresse oxidativo e menores níveis de danos oxidativos...

A wideband scalar network analyzer for biomedical dehydration measurements.

This paper presents a wideband microwave approach towards biomedical dehydration monitoring. The introduced concept is verified via invasive measurements on several blood samples. A microwave measurement circuit, based of a two-port scalar vector network analyzer is presented. The circuit operates between 5GHz and 20GHz using a planar permittivity sensor. Measurements of all subcomponents are shown together with measurements of a Water-NaCl-Glycerol solution.

Transcriptional regulation of the GPX1 gene by TFAP2C and aberrant CpG methylation in human breast cancer.

The complexity of gene regulation has created obstacles to defining mechanisms that establish the patterns of gene expression characteristic of the different clinical phenotypes of breast cancer. TFAP2C is a transcription factor that has a critical role in the regulation of both estrogen receptor-alpha (ERα) and c-ErbB2/HER2 (Her2). Herein, we performed chromatin immunoprecipitation and direct sequencing (ChIP-seq) for TFAP2C in four breast cancer cell lines. Comparing the genomic binding sites for TFAP2C, we identified that glutathione peroxidase (GPX1) is regulated by TFAP2C through an AP-2 regulatory region in the promoter of the GPX1 gene. Knockdown of TFAP2C, but not the related factor TFAP2A, resulted in an abrogation of GPX1 expression. Selenium-dependent GPX activity correlated with endogenous GPX1 expression and overexpression of exogenous GPX1 induced GPX activity and significantly increased resistance to tert-butyl hydroperoxide. Methylation of the CpG island encompassing the AP-2 regulatory region was identified in cell lines where TFAP2C failed to bind the GPX1 promoter and GPX1 expression was unresponsive to TFAP2C. Furthermore, in cell lines where GPX1 promoter methylation was associated with gene silencing, treatment with 5'-aza-2-deoxycytidine (5'-aza-dC) (an inhibitor of DNA methylation) allowed TFAP2C to bind to the GPX1 promoter resulting in the activation of GPX1 RNA and protein expression. Methylation of the GPX1 promoter was identified in ∼20% of primary breast cancers and a highly significant correlation between the TFAP2C and GPX1 expression was confirmed when considering only those tumors with an unmethylated promoter, whereas the related factor, TFAP2A, failed to demonstrate a correlation. The results demonstrate that TFAP2C regulates the expression of GPX1, which influences the redox state and sensitivity to oxidative stress induced by peroxides. Given the established role of GPX1 in breast cancer, the results provide an important mechanism for TFAP2C to further influence oncogenesis and progression of breast carcinoma cells.

Characteristics of adults and children diagnosed with tuberculosis in Lilongwe, Malawi: findings from an integrated HIV/TB clinic.

OBJECTIVES: To describe initial registration characteristics of adult and paediatric TB patients at a large, public, integrated TB and HIV clinic in Lilongwe, Malawi, between January 2008 and December 2010. METHODS: Routine data on patient with TB category and TB type, stratified by HIV and ART status, were used to explore differences in proportions among TB only, TB/HIV co-infected patients not on ART and TB/HIV co-infected patients on ART using chi-square tests. Trends over time illustrate strengths and weaknesses of integrated service provision. RESULTS: Among 10 143 adults, HIV ascertainment and ART uptake were high and increased over time. The proportion of relapse was highest among those on ART (5%). The proportion of smear-positive pulmonary TB (PTB) was highest among HIV-negative patients with TB (34.9%); extra-pulmonary TB (EPTB) was lowest among TB only (16.2%). Among 338 children <15 years, EPTB and smear-positive PTB were more common among TB-only patients. Time trends showed significant increases in the proportion of adults with smear-positive PTB and the proportion of adults already on ART before starting TB treatment. However, some co-infected patients still delay ART initiation. CONCLUSIONS: HIV ascertainment and ART uptake among co-infected patients are successful and improving over time. However, delays in ART initiation indicate some weakness linking TB/HIV patients into ART during TB follow-up care. Improved TB diagnostics and screening efforts, especially for paediatric patients, may help improve quality care for co-infected patients. These results may aid efforts to prioritise TB and HIV prevention, education and treatment campaigns for specific populations.

Selective thoracic ganglionectomy for the treatment of segmental neuropathic pain.

Segmental thoracic neuropathic pain (NeuP) remains particularly difficult to treat. Sensory ganglionectomy was reported to alleviate NeuP. The experience with thoracic ganglionectomy, however, is very limited. Here, we report the results of a prospective pilot study in patients with incapacitating segmental thoracic NeuP treated by selective ganglionectomy. Seven patients were included suffering from refractory NeuP scoring 8 or more on a visual analogue scale (VAS). Every patient had test anaesthesia prior to surgery yielding more than 50% pain relief. The spinal ganglion was excised completely via an extraforaminal approach. Mean preoperative VAS scores were 9.1 (maximum pain); 5.4 (minimum pain); 7.9 (pain on average); 6.9 (pain at the time of presentation); and 7.4 (allodynia). Early post-operatively, there was a marked improvement of mean scores: 1.7; 0.7; 1.2; 1.0; and 0.7, respectively. One patient developed a mild transient hemihypaesthesia. In three patients, substantial pain occurred in a formerly unaffected dermatome within 1 year. Two of these patients had significant pain relief by a second operation. At the time of last follow-up at a mean of 24 months after the first procedure, mean VAS scores were 6.3; 2.1; 4.3; 4.0; and 1.3. Overall, medication was reduced. The patients rated their outcome as excellent (1), good (2), fair (2) and nil (2) with best improvement for allodynia. Selective thoracic ganglionectomy is a safe and partially effective procedure in selected patients albeit there may be partial recurrence of pain. Recurrent pain may affect dermatomes that were not involved initially.

'Task shifting' in an antiretroviral clinic in Malawi: can health surveillance assistants manage patients safely?

Malawi has a critical shortage of clinicians and nurses. This study evaluated whether health surveillance assistants (HSAs) could provide antiretroviral therapy (ART) efficiently and safely for stable patients. HSAs could identify patients with previously established criteria requiring clinical management, including ART initiates, children and patients on second-line treatment. HSAs were not capable of correctly identifying current complications, including potentially severe side effects and toxicities, and inappropriately referred stable patients to clinicians, reducing efficiency. While task shifting to HSAs appears promising, to be safe and efficient, additional clinical training is needed before potentially task shifting stable ART patient care to less skilled health care cadres.

Le Malawi connait un manque critique de cliniciens et d'infirmières. Cette étude a évalué dans quelle mesure les assistants de surveillance de santé (HSA) pourraient distribuer un traitement antirétroviral (ART) de manière efficiente et sûre à des patients en état stable. Les HSA pourraient identifier les patients répondant à des critères préalablement établis, exigeant une prise en charge clinique, notamment les débuts d'ART, les enfants et les patients sous traitement de deuxième ligne. Les HSA n'ont pas été capables d'identifier correctement les complications courantes, notamment les effets collatéraux potentiellement graves et les toxicités ; ils n'ont pas référé de manière appropriée les patients stables aux cliniciens, ce qui a réduit leur efficience. Alors que le transfert de tâches vers les HSA paraît prometteur, pour qu'il soit sûr et efficient, une formation clinique complémentaire s'impose avant de transférer la tâche des soins aux patients ART stables à des cadres de la santé de moindre compétence.

Malaui afronta una grave escasez de personal médico y de enfermería. En el presente estudio se investigó si los auxiliares de vigilancia de la salud (HSA) podrían realizar un suministro eficaz y seguro del tratamiento antirretrovírico (ART) a los pacientes estables. Los ayudantes de vigilancia sanitaria podrían detectar a los pacientes que precisan manejo médico con base en criterios establecidos antes, como los pacientes que comenzaron recientemente el ART, los niños y los pacientes que reciben medicamentos de segunda línea. Los HSA no pudieron reconocer las complicaciones frecuentes, ni las reacciones adversas y las toxicidades que podrían ser graves y remitieron a los médicos, sin razón válida, pacientes estables con lo cual se redujo su eficacia. Si bien la delegación de tareas a los HSA podría parecer prometedora, a fin de velar por la seguridad y la eficiencia de la iniciativa, es preciso impartir una mayor capacitación clínica antes de confiar al personal sanitario menos calificado la atención de pacientes estables que reciben el ART.

Integrated tuberculosis and HIV care in a resource-limited setting: experience from the Martin Preuss centre, Malawi.

OBJECTIVES: To describe the development and operation of integrated tuberculosis (TB) and HIV care at the Martin Preuss Centre, a multipartner organization bringing together governmental and non-governmental providers of HIV and TB services in Lilongwe, Malawi. METHODS: We used a case study approach to describe the integrated TB/HIV service and to illustrate successes and challenges faced by service providers. We quantified effective TB and HIV integration using indicators defined by the World Health Organization. RESULTS: The custom-designed building facilitates patient flow and infection control, and other important elements include coordinated leadership; joint staff training and meetings; and data systems prompting coordinated care. Some integrated services have worked well from the outset, such as promoting HIV testing among patients with TB (96% of patients with TB had documented HIV status in 2009). Other aspects of integrated care have been more challenging, for example achieving high uptake of antiretroviral therapy among HIV-positive TB patients and combining data from paper and electronic systems. Good TB treatment outcomes (>85% cure or completion) have been achieved among both HIV-positive and HIV-negative individuals. CONCLUSIONS: High-quality integrated services for TB and HIV care can be provided in a resource-limited setting. Lessons learned may be valuable for service providers in other settings of high HIV and TB prevalence.