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Background: Studies of planned home births attended by registered midwives have been limited by incomplete data, nonrepresentative sampling, inadequate statistical power and the inability to exclude unplanned home births. We compared the outcomes of planned home births attended by midwives with those of planned hospital births attended by midwives or physicians.Methods: We included all planned home births attended by registered midwives from Jan. 1, 2000, to Dec. 31, 2004, in British Columbia, Canada (n = 2889), and all planned hospital births meeting the eligibility requirements for home birth that were attended by the same cohort of midwives (n = 4752). We also included a matched sample of physician-attended planned hospital births (n = 5331). The primary outcome measure was perinatal mortality; secondary outcomes were obstetric interventions and adverse maternal and neonatal outcomes.Results: The rate of perinatal death per 1000 births was 0.35 (95% confidence interval [CI] 0.00-1.03) in the group of planned home births; the rate in the group of planned hospital births was 0.57 (95% CI 0.00-1.43) among women attended by a midwife and 0.64 (95% CI 0.00-1.56) among those attended by a physician. Women in the planned home-birth group were significantly less likely than those who planned a midwife-attended hospital birth to have obstetric interventions (e.g., electronic fetal monitoring, relative risk [RR] 0.32, 95% CI 0.29-0.36; assisted vaginal delivery, RR 0.41, 95% 0.33-0.52) or adverse maternal outcomes (e.g., third- or fourth-degree perineal tear, RR 0.41, 95% CI 0.28-0.59; postpartum hemorrhage, RR 0.62, 95% CI 0.49-0.77). The findings were similar in the comparison with physician-assisted hospital births. Newborns in the home-birth group were less likely than those in the midwife-attended hospital-birth group to require resuscitation at birth (RR 0.23, 95% CI 0.14-0.37) or oxygen therapy beyond 24 hours (RR 0.37, 95% CI 0.24-0.59). The findings were similar in the comparison with newborns in the physician-assisted hospital births; in addition, newborns in the home-birth group were less likely to have meconium aspiration (RR 0.45, 95% CI 0.21-0.93) and more likely to be admitted to hospital or readmitted if born in hospital (RR 1.39, 95% CI 1.09-1.85).Interpretation: Planned home birth attended by a registered midwife was associated with very low and comparable rates of perinatal death and reduced rates of obstetric interventions and other adverse perinatal outcomes compared with planned hospital birth attended by a midwife or physician. [ABSTRACT FROM AUTHOR]

Background: Current practice guidelines recommend active management of the third stage of labor. We compared practices of three maternity care provider disciplines in management of third-stage labor and the justifications for their approach. Methods: This study is a cross-sectional survey of maternity practitioners in usual practice settings in British Columbia. All 199 obstetricians, all 82 midwives, and a random sample of family physicians practicing intrapartum maternity care (one-third, or 346) were surveyed The three main outcome measures by discipline were the method preferred in managing third-stage labor, the reasons given for the chosen method, and views on the appropriateness of the current third-stage labor guideline. Results: The overall response rate was 57.8 percent. Response rates indicating that the participants were 'aware of guideline' were the following: obstetricians, 85.3 percent; family physicians, 53.7 percent; and midwives, 97.8 percent. Response rates indicating that the participants 'agreed with guideline' were the following: obstetricians, 95.2 percent; family physicians, 97.6 percent; and midwives, 51.2 percent. Response rates indicating that 'oxytocin should be given with anterior shoulder' were the following: obstetricians, 71.1 percent; family physicians, 68.3 percent; and midwives, 26.7 percent. Response rates indicating that 'routine active management of third stage of labor should be the norm' were the following: obstetricians, 79.2 percent; family physicians, 60.2 percent; and midwives, 17 percent. All results were statistically significant (p < 0.01). Conclusions: A major difference was found between physicians and midwives in the management of third-stage labor. Physicians routinely implemented active management of the third stage of labor; midwives preferred expectant approaches, principally based on women's preference. Provincial data did not show differences in postpartum hemorrhage or transfusion rates by practitioner type. (BIRTH 35:3 September 2008) [ABSTRACT FROM AUTHOR]

Background: The impact of midwifery versus physician care on perinatal outcomes in a population of women planning birth in hospital has not yet been explored. We compared maternal and newborn outcomes between women planning hospital birth attended by a midwife versus a physician in British Columbia, Canada. Methods: All women planning a hospital birth attended by a midwife during the 2-year study period who were of sufficiently low-risk status to meet eligibility requirements for home birth as defined by the British Columbia College of Midwives were included in the study group (n = 488). The comparison group included women meeting the same eligibility requirements but planning a physician-attended birth in hospitals where midwives also practiced (n = 572). Outcomes were ascertained from the British Columbia Reproductive Care Program Perinatal Registry to which all hospitals in the province submit data. Results: Adjusted odds ratios for women planning hospital birth attended by a midwife versus a physician were significantly reduced for exposure to cesarean section (OR 0.58, 95% CI 0.39-0.86), narcotic analgesia (OR 0.26, 95% CI 0.18-0.37), electronic fetal monitoring (OR 0.22, 95% CI 0.16-0.30), amniotomy (OR 0.74, 95% CI 0.56-0.98), and episiotomy (OR 0.62, 95% CI 0.42-0.93). The odds of adverse neonatal outcomes were not different between groups, with the exception of reduced use of drugs for resuscitation at birth (OR 0.19, 95% CI 0.04-0.83) in the midwifery group. Conclusions: A shift toward greater proportions of midwife-attended births in hospitals could result in reduced rates of obstetric interventions, with similar rates of neonatal morbidity. (BIRTH 34:2 June 2007) [ABSTRACT FROM AUTHOR]

OBJECTIVE: To describe perinatal outcomes (mortality, weight, condition at birth) at an isolated, rural hospital. DESIGN: A retrospective cohort study. Study population: Neonates born to women beyond 20 weeks' gestation who delivered in the Bella Coola General Hospital (BCGH) between Mar. 7, 1940, and June 9, 2001, inclusive. MAIN OUTCOME MEASURES: Information collected from the labour and delivery case room record book includes Aboriginal status, date of delivery, birth weight, newborn mortality, and newborn condition at birth. RESULTS: There were 2373 deliveries, including 12 sets of twins. Total newborn mortality rates declined from approximately 4.7% in the 1940-1954 time period to 0.7% in the 1970-1984 time period and have remained near that level ever since. From 1940-1960 BCGH's perinatal mortality rate was higher than Canada's; it was lower than Canada's in the 1970s, higher in the 1980s and about the same for the 1990s. The condition of the vast majority (approximately 90%) of newborns was described as being 'good' at birth. Approximately 5% of newborns had birth weights < 2500 g, and this has not changed much over the years. In the 1951-1962 time period Aboriginal women had a higher percentage (8%) of infants with birth weight < 2500 g compared with non-Aboriginal women (5%), but this percentage has declined over time to the point where the rate for both groups is now around 5%. CONCLUSIONS: Women giving birth in the low technology environment of the BCGH experienced acceptable neonatal outcomes. Trends in perinatal mortality, morbidity and low-birth-weight rates mirror those recorded for Canada. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To describe obstetric procedures (episiotomy, forceps, vacuum extraction, caesarean section) and maternal outcomes for patients who gave birth in an isolated, rural hospital. DESIGN: A retrospective cohort study. Study population: Women beyond 20 weeks' gestation who gave birth between Mar. 7, 1940, and June 9, 2001, inclusive, at the Bella Coola General Hospital (BCGH). MAIN OUTCOME MEASURES: Data collected included maternal age, date of delivery, mode of delivery (vaginal delivery v. cesarean section), whether an episiotomy was performed or not, if forceps or vacuum extraction were used, whether analgesia, sedation or anesthesia was used, and maternal mortality. RESULTS: There were 2373 deliveries, including 12 sets of twins. There were no maternal mortalities. Cesarean sections were not routinely performed until the 1970s. Since then, there has been an increase in cesarean section rates to 11% of all deliveries in the 1990s. In the 1940s 28% of deliveries involved an episiotomy. This increased to 47% in the 1970s and was followed by a sharp decline to 4% in the 1990s. There was an increase, followed by a more gradual decrease in the use of forceps, and there was a recent increase in the use of vacuum extraction. The changes in procedure rates appear to reflect best practice guidelines of the times. In the case of episiotomies, the data suggest rural physicians are capable of rapid incorporation of recent recommendations. Rates for all procedures tended to be lower than those reported elsewhere in Canada and the United States. Narcotics, sedatives, inhalation agents and regional anesthetics were used to relieve the pain of labour and delivery throughout the study period. CONCLUSIONS: Women giving birth in the low technology environment of the BCGH experienced relatively low obstetric procedural rates with excellent maternal outcomes. [ABSTRACT FROM AUTHOR]

AIMS AND OBJECTIVES: To evaluate the success of a competency-based nursing orientation programme for a single-room maternity care unit by measuring improvement in self-reported competency after six months. BACKGROUND: Single-room maternity care has challenged obstetrical nurses to provide comprehensive nursing care during all phases of the in-hospital birth experience. In this model, nurses provide intrapartum, postpartum and newborn care in one room. To date, an evaluation of nursing education for single-room maternity care has not been published. DESIGN: A prospective cohort design comparing self-reported competencies prior to starting work in the single-room maternity care and six months after. METHODS: Nurses completed a competency-based education programme in which they could select from a menu of learning methods and content areas according to their individual needs. Learning methods included classroom lectures, self-paced learning packages, and preceptorships in the clinical area. Competencies were measured by a standardized perinatal self-efficacy tool and a tool developed by the authors for this study, the Single-Room Maternity Care Competency Tool. A paired analysis was undertaken to take into account the paired (before and after) nature of the design. RESULTS: Scores on the perinatal self-efficacy scale and the single-room maternity care competency tool were improved. These differences were statistically significant. CONCLUSIONS: Improvements in perinatal and single-room maternity care-specific competencies suggest that our education programme was successful in preparing nurses for their new role in the single-room maternity care setting. This conclusion is supported by reported increases in nursing and patient satisfaction in the single-room maternity care compared with the traditional labour/delivery and postpartum settings. RELEVANCE TO CLINICAL PRACTICE: An education programme tailored to the learning needs of experienced clinical nurses contributes to improvements in nursing competencies and patient care. [ABSTRACT FROM AUTHOR]

A group of family physicians, obstetricians, midwives, obstetric anesthesiologists, and childbirth educators attended an evidence-based symposium in 2001 on the nature and management of labor pain and discussed a series of systematic reviews that focused on methods of labor pain management. Parenteral opioids provide modest pain relief in labor, and little evidence supports the use of one agent over another. Epidural analgesia is used during labor in most large U.S. hospitals, and its use is rapidly increasing in small hospitals. Although epidural analgesia is the most effective form of pain relief, its use is associated with a longer labor, an increased incidence of maternal fever, and increased rates of operative vaginal delivery. The effect of epidural analgesia on rates of cesarean delivery is controversial. Nitrous oxide provides a modest analgesic effect, but it is used less often in the United States than in other developed nations. Paracervical block provides effective analgesia in the first stage of labor, but its use is limited by postblock bradycardia. Research is needed regarding which pain-relief options women would choose if they were offered a range of choices beyond epidural analgesia or parenteral opioids. [ABSTRACT FROM AUTHOR]

Pain in labor is a nearly universal experience for childbearing women. A recent evidence-based symposium on the nature and management of labor pain brought together family physicians, obstetricians, midwives, obstetric anesthesiologists, and childbirth educators to discuss a series of commissioned systematic reviews. Although management of labor pain plays a relatively minor role in a woman's satisfaction with childbirth compared with the quality of the relationship with her maternity caregiver and the degree of participation she has in decision making, it is an important topic for women and their caregivers. Nonpharmacologic methods of pain relief such as labor support, intradermal water blocks, and warm water baths are effective techniques for management of labor pain. An increased availability of these methods can provide effective alternatives for women in labor. [ABSTRACT FROM AUTHOR]

Background: Understanding the association between caregiver belief systems and practice patterns is an emerging area of research. We hypothesized an association between a maternity caregiver's belief system and his or her behavior. The study objective was to determine if a family physician's overall approach to maternity care, as measured by average use of epidural analgesia, was associated with maternal and fetal outcomes. Methods: Retrospective analysis was conducted of the births of three cohorts of 1992 nulliparous, low-riskwomen attended by 96 family physicians within an 18-month period in the department of family practice at the largest maternity hospital in Canada. Cohorts were based on the physicians' mean use of epidural analgesia for the women. Family physicians attending fewer than 5 births were excluded. The main outcome measures, by physician epidural utilization cohort, were maternal/newborn morbidity, procedure rates, consultation rates, and length of stay. Results: Family physicians were separated into cohorts based on their mean use of epidural analgesia at rates of: low, 0-30 percent (15 physicians, 263 births); medium, 31-50 percent (55 physicians,1323 births); and high, 51-100 percent (26 physicians, 406 births). After adjustment for maternal age and race, patients of low versus high epidural users were admitted at a later state of cervical dilation (mean 4.0 vs 3.1 cm), received less electronic fetal monitoring (76.4 vs 87.2) and oxytocin augmentation (12.2 vs 29.8), sustained fewer malpositions (occiput posterior or transverse)(23.2 vs 34.2), had fewer cesarean sections (14.0 vs 24.4), less obstetric consultation (47.9 vs 63.8), and fewer newborn special care admissions (7.2 vs 12.8). Conclusions: In our setting, high use of epidural analgesia is a marker for a style of practice characterized by malpositions leading to dysfunctional labors and higher intervention rates leading, in turn, to excess maternal/newborn morbidity. [ABSTRACT FROM AUTHOR]

BACKGROUND: The introduction of single room maternity care in the 1990s necessitated a new approach to nursing education and practice. A focus on perinatal nursing requires competence across the spectrum of labor, delivery, postpartum and newborn care. We sought to evaluate the nursing response to this change by comparing satisfaction with the workplace environment among single room maternity care nurses before and after they worked in the setting and among nurses working in traditional birth settings. METHODS: Six months before the opening of a pilot seven-bed single room maternity care unit, nurses who planned to work in the new unit completed a survey about their satisfaction with aspects of their work environment. Three months after the new unit opened the survey was repeated with this study group and also by a sample of nurses working in the delivery and postpartum areas. RESULTS: Responses indicated that single room maternity care nurses before and after working in the unit were significantly more satisfied with the physical setting, their ability to respond to patients' needs, their opportunity for teaching families, the nursing practice environment, peer support, and their perceived level of competency. They rated their satisfaction significantly higher than that of their colleagues in the traditional delivery and postpartum settings. CONCLUSIONS: The positive transition to single room maternity care by obstetrical nurses was demonstrated by their improved overall satisfaction with the work environment. Evaluation of the nurses' responses to changes in health care delivery has important implications for justifying new clinical approaches and planning for future changes. [ABSTRACT FROM AUTHOR]

Background: Preference for formula versus breast feeding among women of Chinese descent remains a concern in North America. The goal of this study was to develop an intervention targeting Chinese immigrant mothers to increase their rates of exclusive breastfeeding.Methods: We convened a focus group of immigrant women of Chinese descent in Vancouver, British Columbia to explore preferences for method of infant feeding. We subsequently surveyed 250 women of Chinese descent to validate focus group findings. Using a participatory approach, our focus group participants reviewed survey findings and developed a priority list for attributes of a community-based intervention to support exclusive breastfeeding in the Chinese community. The authors and focus group participants worked as a team to plan, implement and evaluate a Chinese language newborn feeding information telephone service staffed by registered nurses fluent in Chinese languages.Results: Participants in the focus group reported a strong preference for formula feeding. Telephone survey results revealed that while pregnant Chinese women understood the benefits of breastfeeding, only 20.8% planned to breastfeed exclusively. Only 15.6% were breastfeeding exclusively at two months postpartum. After implementation of the feeding hotline, 20% of new Chinese mothers in Vancouver indicated that they had used the hotline. Among these women, the rate of exclusive breastfeeding was 44.1%; OR 3.02, (95% CI 1.78-5.09) compared to women in our survey.Conclusion: Initiation of a language-specific newborn feeding telephone hotline reached a previously underserved population and may have contributed to improved rates of exclusive breastfeeding. [ABSTRACT FROM AUTHOR]

Combination of nanoagents with radiations has opened up new perspectives in cancer treatment, improving both tumor diagnosis and therapeutic index. This work presents the first investigation of an innovative strategy that combines porous metal-organic frameworks (nanoMOFs) loaded with the anti-cancer drug Gemcitabine monophosphate (GemMP) and particle therapy-a globally emerging technique that offers more precise radiation targeting and enhanced biological efficacy compared to conventional radiotherapy. This radiochemotherapy has been confronted with two major obstacles limiting the efficacy of therapeutics when tested in vivo: (i) the presence of hypoxia, one of the most important causes for radiotherapy failure and (ii) the presence of a microenvironment, main biological barrier to the direct penetration of nanoparticles into cancer cells. On the one hand, this study explore the effects of hypoxia on drug delivery systems in combination with radiation, demonstrating that GemMP-loaded nanoMOFs significantly enhance the anticancer efficacy of particle therapy under both normoxic (pO 2  = 20 %) and hypoxic (pO 2  = 0.5 %) conditions. Notably, the presence of GemMP-loaded nanoMOFs allows the irradiation dose to be reduced by 1.4-fold in normoxia and at least 1.6-fold in hypoxia, achieving the same cytotoxic effect (SF=10 %) as carbon or helium ions alone. Synergistic effects between GemMP-loaded nanoMOFs and radiations have been observed and quantified. On the other hand, we also highlighted the ability of the nanoMOFs to diffuse through an extracellular matrix and accumulate in cells. An higher effect of the encapsulated GemMP than the free drug was observed, confirming the key role of the nanoMOFs in transporting the active substance to the cancer cells as a Trojan horse. This paves the way to the design of "all-in-one" nanodrugs where each component plays a role in the optimization of cancer therapy to maximize cytotoxic effects on hypoxic tumor cells while minimizing toxicity on healthy tissue., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Controlling the assembly of high-order structures is central to soft-matter and biomaterial engineering. Angle-resolved linear dichroism can probe the ordering of chiral collagen molecules in the dense state. Collagen triple helices were aligned by solvent evaporation. Their ordering gives a strong linear dichroism (LD) that changes sign and intensity with varying sample orientations with respect to the beam linear polarization. Being complementary to circular dichroism, which probes the structure of chiral (bio)molecules, LD can shift from the molecular to the supramolecular scale and from the investigation of the conformation to interactions. Supported by multiphoton microscopy and X-ray scattering, we show that LD provides a straightforward route to probe collagen alignment, determine the packing density, and monitor denaturation. This approach could be adapted to any assembly of chiral (bio)macromolecules, with key advantages in detecting large-scale assemblies with high specificity to aligned and chiral molecules and improved sensitivity compared to conventional techniques.

Ovarian cancer is the most lethal gynecologic cancer in developed countries. In the tumor microenvironment, the extracellular matrix (ECM) and flow shear stress are key players in directing ovarian cancer cells invasion. Artificial ECM models based only on ECM proteins are used to build an ovarian tumor-on-chip to decipher the crosstalk between ECM and shear stress on the migratory behavior and cellular heterogeneity of ovarian tumor cells. This work shows that in the shear stress regime of the peritoneal cavity, the ECM plays a major role in driving individual or collective ovarian tumor cells migration. In the presence of basement membrane proteins, migration is more collective than on type I collagen regardless of shear stress. With increasing shear stress, individual cell migration is enhanced; while, no significant impact on collective migration is measured. This highlights the central position that ECM and flow shear stress should hold in in vitro ovarian cancer models to deepen understanding of cellular responses and improve development of ovarian cancer therapeutic platforms. In this frame, adding flow provides significant improvement in biological relevance over the authors' previous work. Further steps for enhanced clinical relevance require not only multiple cell lines but also patient-derived cells and sera., (© 2024 Wiley‐VCH GmbH.)

Uterine cervical remodeling is a fundamental feature of pregnancy, facilitating the delivery of the fetus through the cervical canal. Yet, we still know very little about this process due to the lack of methodologies that can quantitatively and unequivocally pinpoint the changes the cervix undergoes during pregnancy. We utilize polarization-resolved second harmonic generation to visualize the alterations the cervix extracellular matrix, specifically collagen, undergoes during pregnancy with exquisite resolution. This technique provides images of the collagen orientation at the pixel level (0.4 μm) over the entire murine cervical section. They show tight and ordered packing of collagen fibers around the os at the early stage of pregnancy and their disruption at the later stages. Furthermore, we utilize a straightforward statistical analysis to demonstrate the loss of order in the tissue, consistent with the loss of mechanical properties associated with this process. This work provides a deeper understanding of the parturition process and could support research into the cause of pathological or premature birth., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Introduction/aims: Diagnosis of small-fiber neuropathy (SFN) is hampered by its subjective symptoms and signs. Confirmatory testing is insufficiently available and expensive, so predictive examinations have value. However, few support the 2020 SFN consensus-case-definition requirements or were validated for non-diabetes neuropathies. Thus we developed the Massachusetts General Hospital Neuropathy Exam Tool (MAGNET) and measured diagnostic performance in 160 symptomatic patients evaluated for length-dependent SFN from any cause and 37 healthy volunteers., Methods: We compared prevalences of abnormalities (vital signs, pupil responses, lower-limb appearance, pin, light touch, vibration and position sensitivity, great-toe strength, muscle stretch reflexes), and validated diagnostic performance against objective SFN tests: lower-leg skin-biopsy epidermal neurite densities and autonomic function testing (AFT). Sensitivity/specificity, feasibility, test-retest and inter-rater reliability, and convergence with the Utah Early Neuropathy Scale were calculated., Results: Patients' ages averaged 48.5 ± 14.7 years and 70.6% were female. Causes of neuropathy varied, remaining unknown in 59.5%. Among the 46 with abnormal skin biopsies, the most prevalent abnormality was reduced pin sharpness at the toes (71.7%). Inter-rater reliability, test-retest reliability, and convergent validity excelled (range = 91.3-95.6%). Receiver operating characteristics comparing all symptomatic patients versus healthy controls indicated that a MAGNET threshold score of 14 maximized predictive accuracy for skin biopsies (0.74) and a 30 cut-off maximized accuracy for predicting AFT (0.60). Analyzing patients with any abnormal neuropathy-test results identified areas-under-the-curves of 0.87-0.89 for predicting a diagnostic result, accuracy = 0.80-0.89, and Youden's index = 0.62. Overall, MAGNET was 80%-85% accurate for stratifying patients with abnormal versus normal neuropathy test results., Discussion: MAGNET quickly generates research-quality metrics during clinical examinations., (© 2023 Wiley Periodicals LLC.)

Chlorophyll fluorescence measured at the leaf scale through pulse amplitude modulation (PAM) has provided valuable insight into photosynthesis. At the canopy- and satellite-scale, solar-induced fluorescence (SIF) provides a method to estimate the photosynthetic activity of plants across spatiotemporal scales. However, retrieving SIF signal remotely requires instruments with high spectral resolution, making it difficult and often expensive to measure canopy-level steady-state chlorophyll fluorescence under natural sunlight. Considering this, we built a novel low-cost photodiode system that retrieves far-red chlorophyll fluorescence emission induced by a blue light emitting diode (LED) light source, for 2 h at night, above the canopy. Our objective was to determine if an active remote sensing-based night-time photodiode method could track changes in canopy-scale LED-induced chlorophyll fluorescence (LEDIF) during an imposed drought on a broadleaf evergreen shrub, Polygala myrtifolia . Far-red LEDIF (720-740 nm) was retrieved using low-cost photodiodes (LEDIF photodiode ) and validated against measurements from a hyperspectral spectroradiometer (LEDIF hyperspectral ). To link the LEDIF signal with physiological drought response, we tracked stomatal conductance ( g sw ) using a porometer, two leaf-level vegetation indices-photochemical reflectance index and normalized difference vegetation index-to represent xanthophyll and chlorophyll pigment dynamics, respectively, and a PAM fluorimeter to measure photochemical and non-photochemical dynamics. Our results demonstrate a similar performance between the photodiode and hyperspectral retrievals of LEDIF ( R 2  = 0.77). Furthermore, LEDIF photodiode closely tracked drought responses associated with a decrease in photochemical quenching ( R 2  = 0.69), F v / F m ( R 2  = 0.59) and leaf-level photochemical reflectance index ( R 2  = 0.59). Therefore, the low-cost LEDIF photodiode approach has the potential to be a meaningful indicator of photosynthetic activity at spatial scales greater than an individual leaf and over time., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Annals of Botany Company.)

Significance: Imaging Mueller polarimetry is capable to trace in-plane orientation of brain fiber tracts by detecting the optical anisotropy of white matter of healthy brain. Brain tumor cells grow chaotically and destroy this anisotropy. Hence, the drop in scalar retardance values and randomization of the azimuth of the optical axis could serve as the optical marker for brain tumor zone delineation., Aim: The presence of underlying crossing fibers can also affect the values of scalar retardance and the azimuth of the optical axis. We studied and analyzed the impact of fiber crossing on the polarimetric images of thin histological sections of brain corpus callosum., Approach: We used the transmission Mueller microscope for imaging of two-layered stacks of thin sections of corpus callosum tissue to mimic the overlapping brain fiber tracts with different fiber orientations. The decomposition of the measured Mueller matrices was performed with differential and Lu-Chipman algorithms and completed by the statistical analysis of the maps of scalar retardance, azimuth of the optical axis, and depolarization., Results: Our results indicate the sensitivity of Mueller polarimetry to different spatial arrangement of brain fiber tracts as seen in the maps of scalar retardance and azimuth of optical axis of two-layered stacks of corpus callosum sections The depolarization varies slightly ( < 15 % ) with the orientation of the optical axes in both corpus callosum stripes, but its value increases by 2.5 to 3 times with the stack thickness., Conclusions: The crossing brain fiber tracts measured in transmission induce the drop in values of scalar retardance and randomization of the azimuth of the optical axis at optical path length of 15    μ m . It suggests that the presence of nerve fibers crossing within the depth of few microns will be also detected in polarimetric maps of brain white matter measured in reflection configuration., (© 2023 The Authors.)

Calcific uremic arteriolopathy (CUA) is a severely morbid disease, affecting mostly dialyzed end-stage renal disease (ESRD) patients, associated with calcium deposits in the skin. Calcifications have been identified in ESRD patients without CUA, indicating that their presence is not specific to the disease. The objective of this retrospective multicenter study was to compare elastic fiber structure and skin calcifications in ESRD patients with CUA to those without CUA using innovative structural techniques. Fourteen ESRD patients with CUA were compared to 12 ESRD patients without CUA. Analyses of elastic fiber structure and skin calcifications using multiphoton microscopy followed by machine-learning analysis and field-emission scanning electron microscopy coupled with energy dispersive X-ray were performed. Elastic fibers specifically appeared fragmented in CUA. Quantitative analyses of multiphoton images showed that they were significantly straighter in ESRD patients with CUA than without CUA. Interstitial and vascular calcifications were observed in both groups of ESRD patients, but vascular calcifications specifically appeared massive and circumferential in CUA. Unlike interstitial calcifications, massive circumferential vascular calcifications and elastic fibers straightening appeared specific to CUA. The origins of such specific elastic fiber's alteration are still to be explored and may involve relationships with ischemic vascular or inflammatory processes., (© 2023. Springer Nature Limited.)

A key property of the human cornea is to maintain its curvature and consequently its refraction capability despite daily changes in intraocular pressure. This is closely related to the multiscale structure of the corneal stroma, which consists of 1-3 µm-thick stacked lamellae made of thin collagen fibrils. Nevertheless, the distribution, size, and orientation of these lamellae along the depth of the cornea are poorly characterized up to now. In this study, we use second harmonic generation (SHG) microscopy to visualize the collagen distribution over the full depth of 10 intact and unstained human corneas (500-600 µm thick). We take advantage of the small coherence length in epi-detection to axially resolve the lamellae while maintaining the corneal physiological curvature. Moreover, as raw epi-detected SHG images are spatially homogenous because of the sub-wavelength size of stromal collagen fibrils, we use a polarimetric approach to measure the collagen orientation in every voxel. After a careful validation of this approach, we show that the collagen lamellae (i) are mostly oriented along the inferior-superior axis in the anterior stroma and along the nasal-temporal axis in the posterior stroma, with a gradual shift in between and (ii) exhibit more disorder in the anterior stroma. These results represent the first quantitative characterization of the lamellar structure of the human cornea continuously along its entire thickness with micrometric resolution. It also shows the unique potential of P-SHG microscopy for imaging of collagen distribution in thick dense tissues., (© 2023. The Author(s).)

Cellular heterogeneity is associated with many physiological processes, including pathological ones, such as morphogenesis and tumorigenesis. The extracellular matrix (ECM) is a key player in the generation of cellular heterogeneity. Advances in our understanding rely on our ability to provide relevant in vitro models. This requires obtainment of the characteristics of the tissues that are essential for controlling cell fate. To do this, we must consider the diversity of tissues, the diversity of physiological contexts, and the constant remodeling of the ECM along these processes. To this aim, we have fabricated a library of ECM models for reproducing the scaffold of connective tissues and the basement membrane by using different biofabrication routes based on the electrospinning and drop casting of biopolymers from the ECM. Using a combination of electron microscopy, multiphoton imaging, and AFM nanoindentation, we show that we can vary independently protein composition, topology, and stiffness of ECM models. This in turns allows one to generate the in vivo complexity of the phenotypic landscape of ovarian cancer cells. We show that, while this phenotypic shift cannot be directly correlated with a unique ECM feature, the three-dimensional collagen fibril topology patterns cell shape, beyond protein composition and stiffness of the ECM. On this line, this work is a further step toward the development of ECM models recapitulating the constantly remodeled environment that cells face and thus provides new insights for cancer model engineering and drug testing.

Nondestructive and noninvasive investigation techniques are highly sought-after to establish the degradation state of historical parchments, which is up to now assessed by thermal techniques that are invasive and destructive. We show that advanced nonlinear optical (NLO) microscopy enables quantitative in situ mapping of parchment degradation at the micrometer scale. We introduce two parameters that are sensitive to different degradation stages: the ratio of two-photon excited fluorescence to second harmonic generation (SHG) signals probes severe degradation, while the anisotropy parameter extracted from polarization-resolved SHG measurements is sensitive to early degradation. This approach is first validated by comparing NLO quantitative parameters to thermal measurements on artificially altered contemporary parchments. We then analyze invaluable parchments from the Middle Ages and show that we can map their conservation state and assess the impact of a restoration process. NLO quantitative microscopy should therefore help to identify parchments most at risk and optimize restoration methods., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY).)

The human cornea is mainly composed of collagen fibrils aligned together within stacked lamellae. This lamellar structure can be affected in pathologies such as keratoconus, which is characterized by progressive corneal thinning and local steepening. In this study, we use polarization-resolved second harmonic generation (P-SHG) microscopy to characterize 8 control and 6 keratoconic human corneas. Automated processing of P-SHG images of transverse sections provides the collagen orientation in every pixel with sub-micrometer resolution. Series of P-SHG images recorded in the most anterior region of the stroma evidence sutural lamellae inclined at 22° ± 5° to the corneal surface, but show no significant difference between control and keratoconic corneas. In contrast, series of P-SHG images acquired along the full thickness of the stroma show a loss of order in the lamellar structure of keratoconic corneas, in agreement with their defective mechanical properties. This structural difference is analyzed quantitatively by computing the entropy and the orientation index of the collagen orientation distribution and significant differences are obtained along the full thickness of the stroma. This study shows that P-SHG is an effective tool for automatic quantitative analysis of structural defects of human corneas and should be applied to other collagen-rich tissues., Competing Interests: The authors declare no conflicts of interest., (© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.)

Smooth muscle cells (SMCs) are critical players in cardiovascular disease development and undergo complex phenotype switching during disease progression. However, SMC phenotype is difficult to assess and track in co-culture studies. To determine the contractility of SMCs embedded within collagen hydrogels, we performed polarized light imaging and subsequent analysis based on Mueller matrices. Measurements were made both in the absence and presence of endothelial cells (ECs) in order to establish the impact of EC-SMC communication on SMC contractility. The results demonstrated that Mueller polarimetric imaging is indeed an appropriate tool for assessing SMC activity which significantly modifies the hydrogel retardance in the presence of ECs. These findings are consistent with the idea that EC-SMC communication promotes a more contractile SMC phenotype. More broadly, our findings suggest that Mueller polarimetry can be a useful tool for studies of spatial heterogeneities in hydrogel remodeling by SMCs.

2D cell cultures are commonly used to rapidly evaluate the therapeutic potential of various treatments on living cells. However, the effects of the extracellular matrix (ECM) including the 3D arrangement of cells and the complex physiology of native environment are missing, which makes these models far from in vivo conditions. 3D cell models have emerged in preclinical studies to simulate the impact of the ECM and partially bridge the gap between monolayer cultures and in vivo tissues. To date, the difficulty to handle the existing 3D models, the cost of their production and their poor reproducibility have hindered their use. Here, we present a reproducible and commercially available "3D cell collagen-based model" (3D-CCM) that allows to study the influence of the matrix on nanoagent uptake and radiation effects. The cell density in these samples is homogeneous. The oxygen concentration in the 3D-CCM is tunable, which opens the opportunity to investigate hypoxic effects. In addition, thanks to the intrinsic properties of the collagen, the second harmonic imaging microscopy may be used to probe the whole volume and visualize living cells in real-time. Thus, the architecture and composition of 3D-CCMs as well as the impact of various therapeutic strategies on cells embedded in the ECM is observed directly. Moreover, the disaggregation of the collagen matrix allows recovering of cells without damaging them. It is a major advantage that makes possible single cell analysis and quantification of treatment effects using clonogenic assay. In this work, 3D-CCMs were used to evaluate the correlative efficacies of nanodrug exposure and medical radiation on cells contained in a tumor like sample. A comparison with monolayer cell cultures was performed showing the advantageous outcome and the higher potential of 3D-CCMs. This cheap and easy to handle approach is more ethical than in vivo experiments, thus, giving a fast evaluation of cellular responses to various treatments., Competing Interests: FL and OT must disclose the patent WO2011/135101. This patent protects the AGuIX® nanoparticles described in this publication and their administration via the airways. FL and OT are employees of NH TherAGuIX® which is developing the AGuIX® nanoparticles. FL and OT possess shares of this company. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Maury, Porcel, Mau, Lux, Tillement, Mahou, Schanne-Klein and Lacombe.)

The elaboration of scaffolds able to efficiently promote cell differentiation toward a given cell type remains challenging. Here, we engineered dense type I collagen threads with the aim of providing scaffolds with specific morphological and mechanical properties for C3H10T1/2 mesenchymal stem cells. Extrusion of pure collagen solutions at different concentrations (15, 30, and 60 mg/mL) in a PBS 5× buffer generated dense fibrillated collagen threads. For the two highest concentrations, threads displayed a core-shell structure with a marked fibril orientation of the outer layer along the longitudinal axis of the threads. Young's modulus and ultimate tensile stress as high as 1 and 0.3 MPa, respectively, were obtained for the most concentrated collagen threads without addition of any cross-linkers. C3H10T1/2 cells oriented themselves with a mean angle of 15-24° with respect to the longitudinal axis of the threads. Cells penetrated the 30 mg/mL scaffolds but remained on the surface of the 60 mg/mL ones. After three weeks of culture, cells displayed strong expression of the tendon differentiation marker Tnmd, especially for the 30 mg/mL threads. These results suggest that both the morphological and mechanical characteristics of collagen threads are key factors in promoting C3H10T1/2 differentiation into tenocytes, offering promising levers to optimize tissue engineering scaffolds for tendon regeneration.

In mammalian cells, one-third of all polypeptides is transported into or through the ER-membrane via the Sec61-channel. While the Sec61-complex facilitates the transport of all polypeptides with amino-terminal signal peptides (SP) or SP-equivalent transmembrane helices (TMH), the translocating chain-associated membrane protein (now termed TRAM1) was proposed to support transport of a subset of precursors. To identify possible determinants of TRAM1 substrate specificity, we systematically identified TRAM1-dependent precursors by analyzing cellular protein abundance changes upon TRAM1 depletion in HeLa cells using quantitative label-free proteomics. In contrast to previous analysis after TRAP depletion, SP and TMH analysis of TRAM1 clients did not reveal any distinguishing features that could explain its putative substrate specificity. To further address the TRAM1 mechanism, live-cell calcium imaging was carried out after TRAM1 depletion in HeLa cells. In additional contrast to previous analysis after TRAP depletion, TRAM1 depletion did not affect calcium leakage from the ER. Thus, TRAM1 does not appear to act as SP- or TMH-receptor on the ER-membrane's cytosolic face and does not appear to affect the open probability of the Sec61-channel. It may rather play a supportive role in protein transport, such as making the phospholipid bilayer conducive for accepting SP and TMH in the vicinity of the lateral gate of the Sec61-channel. Abbreviations: ER, endoplasmic reticulum; OST, oligosaccharyltransferase; RAMP, ribosome-associated membrane protein; SP, signal peptide; SR, SRP-receptor; SRP, signal recognition particle; TMH, signal peptide-equivalent transmembrane helix; TRAM, translocating chain-associated membrane protein; TRAP, translocon-associated protein.

Bio-engineering technologies are currently used to produce biomimetic artificial corneas that should present structural, chemical, optical, and biomechanical properties close to the native tissue. These properties are mainly supported by the corneal stroma which accounts for 90% of corneal thickness and is mainly made of collagen type I. The stromal collagen fibrils are arranged in lamellae that have a plywood-like organization. The fibril diameter is between 25 and 35 nm and the interfibrillar space about 57 nm. The number of lamellae in the central stroma is estimated to be 300. In the anterior part, their size is 10-40 μm. They appear to be larger in the posterior part of the stroma with a size of 60-120 μm. Their thicknesses also vary from 0.2 to 2.5 μm. During development, the acellular corneal stroma, which features a complex pattern of organization, serves as a scaffold for mesenchymal cells that invade and further produce the cellular stroma. Several pathways including Bmp4, Wnt/β-catenin, Notch, retinoic acid, and TGF-β, in addition to EFTFs including the mastering gene Pax-6, are involved in corneal development. Besides, retinoic acid and TGF- β seem to have a crucial role in the neural crest cell migration in the stroma. Several technologies can be used to produce artificial stroma. Taking advantage of the liquid-crystal properties of acid-soluble collagen, it is possible to produce transparent stroma-like matrices with native-like collagen I fibrils and plywood-like organization, where epithelial cells can adhere and proliferate. Other approaches include the use of recombinant collagen, cross-linkers, vitrification, plastically compressed collagen or magnetically aligned collagen, providing interesting optical and mechanical properties. These technologies can be classified according to collagen type and origin, presence of telopeptides and native-like fibrils, structure, and transparency. Collagen matrices feature transparency >80% for the appropriate 500-μm thickness. Non-collagenous matrices made of biopolymers including gelatin, silk, or fish scale have been developed which feature interesting properties but are less biomimetic. These bioengineered matrices still need to be colonized by stromal cells to fully reproduce the native stroma., (Copyright © 2020. Published by Elsevier Ltd.)

Rebuilding biological environments is crucial when facing the challenges of fundamental and biomedical research. Thus, preserving the native state of biomolecules is essential. We use electrospinning (ES), which is an extremely promising method for the preparation of fibrillar membranes to mimic the ECM of native tissues. Here, we report for the first time (1) the ES of pure and native collagen into a self-supported membrane in absence of cross-linker and polymer support, (2) the preservation of the membrane integrity in hydrated media in absence of cross-linker, and (3) the preservation of the native molecular structure and recovery of the hierarchical assembly of collagen. We use a multiscale approach to characterize collagen native structure at the molecular level using circular dichroism, and to investigate collagen hierarchical organization within the self-supported membrane using a combination of multiphoton and electron microscopies. Finally, we show that the membranes are perfectly suited for cell adhesion and spreading, making them very promising candidates for the development of biomaterials and finding applications in biomedical research.

Background: Bereaved parents experience higher rates of depressive and post-traumatic stress symptoms after the stillbirth of a baby than after live-birth. Yet, these effects remain underreported in the literature and, consequently, insufficiently addressed in health provider education and practice. We conducted a participatory based study to explore the experiences of grieving parents during their interaction with health care providers during and after the stillbirth of a baby., Methods: This community-based participatory study utilized four focus groups comprised of twenty-seven bereaved parents (44% fathers). Bereaved parents conceptualized the study, participating at all stages of research, analyses, and drafting. Data were reduced into a main theme and subthemes, then broad-based member checked to ensure fidelity and nuances within themes., Results: The major theme that emerged centered on provider acknowledgement of the baby as an irreplaceable individual. Subthemes reflected 1) acknowledgement of parenthood and grief, 2) recognition of the traumatic nature of stillbirth, and 3) acknowledgement of enduring grief coupled with access to support. It was important that providers realized how grief was experienced within health care and social support systems, concretized by their desire for long-term, specialized support., Conclusions: Both mothers and fathers feel that acknowledgement of their baby as an individual, their parenthood, and their enduring traumatic grief by healthcare providers are key elements required in the process of initiating immediate and ongoing care after the stillbirth of a baby.