12,712 research outputs found

    Cardiopulmonary Inflammatory Response to Meteorite Dust Exposures - Implications for Human Health on Earth and Beyond

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    This year marks the 50th anniversary of Apollo 11, the first time humans set foot on the Moon. The Apollo missions not only help answer questions related to our solar system, they also highlight many hazards associated with human space travel. One major concern is the effect of extraterrestrial dust on astronaut health. In an effort to expand upon previous work indicating lunar dust is respirable and reactive, the authors initiated an extensive study evaluating the role of a particulates innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. To allow for a broader planetary and geochemical assessment, seven samples were evaluated: six meteorites from either the Moon, Mars, or Asteroid 4 Vesta and a terrestrial basalt analogue. Even with the relatively small geochemical differences (all samples basaltic in nature), significant difference in cardiopulmonary inflammatory markers developed in both single exposure and multiple exposure studies. More specifically: 1) the single exposure studies reveal relationships between toxicity and a meteorite samples origin, its pre-ejected state (weathered versus un-weathered), and geochemical features (e.g. bulk iron content) and 2) multiple exposure studies reveal a correlation with particle derived reactive oxygen species (ROS) formation and neutrophil infiltration. Extended human exploration will further increase the probability of inadvertent and repeated exposures to extraterrestrial dusts. This comprehensive dataset allows for not only the toxicological evaluation of extraterrestrial materials but also clarifies important correlations between geochemistry and health. The utilization of an array of extraterrestrial samples from Moon, Mars, and asteroid 4Vesta will enable the development of a geochemical based toxicological hazard model that can be used for: 1) mission planning, 2) rapid risk assessment in cases of unexpected exposures, and 3) evaluation of the efficacy of various in situ techniques in gauging surface dust toxicity. Furthermore, by better understanding the importance of geochemical features on exposure related health outcomes in space, it is possible to better understand of the deleterious nature of dust exposure on Earth

    Selective deletion of cochlear hair cells causes rapid age-dependent changes in spiral ganglion and cochlear nucleus neurons

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    During nervous system development, critical periods are usually defined as early periods during which manipulations dramatically change neuronal structure or function, whereas the same manipulations in mature animals have little or no effect on the same property. Neurons in the ventral cochlear nucleus (CN) are dependent on excitatory afferent input for survival during a critical period of development. Cochlear removal in young mammals and birds results in rapid death of target neurons in the CN. Cochlear removal in older animals results in little or no neuron death. However, the extent to which hair-cell-specific afferent activity prevents neuronal death in the neonatal brain is unknown. We further explore this phenomenon using a new mouse model that allows temporal control of cochlear hair cell deletion. Hair cells express the human diphtheria toxin (DT) receptor behind the Pou4f3 promoter. Injections of DT resulted in nearly complete loss of organ of Corti hair cells within 1 week of injection regardless of the age of injection. Injection of DT did not influence surrounding supporting cells directly in the sensory epithelium or spiral ganglion neurons (SGNs). Loss of hair cells in neonates resulted in rapid and profound neuronal loss in the ventral CN, but not when hair cells were eliminated at a more mature age. In addition, normal survival of SGNs was dependent on hair cell integrity early in development and less so in mature animals. This defines a previously undocumented critical period for SGN survival

    Coexistence of Ferromagnetism and Superconductivity in Noncentrosymmetric Materials with Cubic Symmetry

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    This is a model study for the emergence of superconductivity in ferromagnetically ordered phases of cubic materials whose crystal structure lacks inversion symmetry. A Ginzburg-Landau-type theory is used to find the ferromagnetic state and to determine the coupling of magnetic order to superconductivity. It is found that noncentrosymmetricity evokes a helical magnetic phase. If the wavelength of the magnetic order is long enough, it gives rise to modulations of the order parameter of superconductivity, both in modulus and complex phase. At magnetic domain walls the nucleation of superconductivity is found to be suppressed as compared to the interior of ferromagnetic domains.Comment: 5 pages, 2 figure

    AN EVALUATION OF THE WOUND HEALING AND ANTI-MICROBIAL PROPERTY OF THE TINCTURE OF LANTANA CAMARA

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    Objective: Lantana camaraL (L. c) has been known for its anti-bacterial activity since quite some time in its various extracts and pharmacological preparations. In view of this, we plan to study and compare the wound healing property of tincture of L. cin surgically induced wound in animal models with tincture of iodine (I2).Methods: An herbal tincture was developed from stems of L. cin concentrations of 20%, 40%, alcohol in tincture was followed as mentioned in IP, tested against tincture I2 in same aged different groups of rats under incision and excision models, also with commonly wound infecting bacteria like S. aureus, E. coli, E. fecalis, P. aeruginosa[a1] . Wounds were induced surgically under anaesthesia. Excised rats were observed for wound contraction and epithelialisation. On 7th day, incised rats were subjected to wound dehiscence test. Tissue biopsy took on day 5, 14 and21 for histopathological studies.Results: Both test groups were found statistically significant against standard with P<0.05 and with mean epithelialisation day value 11±1.02 in the excision model and P<0.05 between the groups in incision model depicting 20% tincture as better with a mean value of 366.67±47.2. Histologically 40% tincture was found non-inferior against standard. Tincture was active against mentioned microbes in various dilutions.Conclusion: Tincture L. c was non-inferior to iodine. Further studies with concentrated extracts of L. cmay reveal its accelerated healing and better anti-microbial competency so that it can be developed for clinical practice.Â

    Factors influencing patients’ decision-making about preimplantation genetic testing for monogenic disorders

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    STUDY QUESTION: What are the roles of individual and interpersonal factors in couples’ decision-making regarding preimplantation genetic testing for monogenic disorders (PGT-M)? SUMMARY ANSWER: Couples’ decision-making regarding PGT-M was associated with individual and interpersonal factors, that is the perceived consistency of information received, satisfaction with information, self-efficacy (individuals’ beliefs in their ability to make decisions), actual knowledge about PGT-M and social support from the partner. WHAT IS KNOWN ALREADY: Various factors have been shown to be associated with decision-making regarding PGT-M. However, PGT-M is experienced at an individual level, and to date, no studies have investigated the roles of the above-mentioned individual and interpersonal factors. STUDY DESIGN, SIZE, DURATION: This is a cross-sectional study with 279 participants. Participants were recruited through IVFAustralia, Sydney Children’s Hospital and support groups from May 2020 to November 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were women who had undergone or were considering PGT-M and their partners. Participants were recruited through IVFAustralia, Sydney Children’s Hospital and support groups to complete online questionnaires. Decisional regret, decisional satisfaction and decisional conflict were measured as outcome variables. Multiple linear regressions were performed to examine the association between factors and outcome variables. Mann–Whitney U tests were performed to test the differences between participants who had undergone PGT-M and those who were considering PGT-M. MAIN RESULTS AND THE ROLE OF CHANCE: For couples who had undergone PGT-M, decisional regret was significantly negatively associated with perceived consistency of information received (b = -0.26, P < 0.01), self-efficacy (b = -0.25, P < 0.01) and actual knowledge about PGT-M (b = -0.30, P < 0.001), while decisional satisfaction had positive association with satisfaction with information received (b = 0.37, P < 0.001) and self-efficacy (b = 0.24, P < 0.05). For couples who were considering PGT-M, decisional conflict was negatively associated with satisfaction with information received (b = -0.56, P < 0.001). For females who had undergone PGT-M, decisional regret was negatively associated with social support from the partner (b = -0.35, P < 0.05) in addition to perceived consistency of information received (b = -0.24, P < 0.05). In this group, decisional satisfaction was positively associated with women’s satisfaction with the information received (b = 0.34, P < 0.01), social support from the partner (b = 0.26, P < 0.05) and self-efficacy (b = 0.25, P < 0.05). For females who were considering PGT-M, decisional conflict was negatively associated with satisfaction with the information received (b = -0.43, P < 0.01) and social support from the partner (b = -0.30, P < 0.05). This study also identified those aspects of PGT-M that couples felt most concerned about in relation to their decision-making, in particular safety issues such as short- or long-term health problems for the baby and potential harms to the embryos and the mother’s health. The likelihood of getting pregnant and having a baby with a genetic condition being tested for were also important in couples’ decision-making. LIMITATIONS, REASONS FOR CAUTION: This study assessed the concerns of couples about having a baby with a variety of genetic conditions. However, condition-specific issues might not be covered. Furthermore, social support from the partner was assessed among females only. Male participants’ perceived social support from their partner and the association between mutual support and decision-making were not assessed due to the absence of dyadic data. WIDER IMPLICATIONS OF THE FINDINGS: Results highlight the importance of effective patient education on PGT-M and the need to provide high-quality and consistent information in the context of patient-centred care. Patients are likely to benefit from information that addresses their specific concerns in relation to PGT-M. From females’ perspective, support from partners is essential, and partners should, therefore, be encouraged to participate in all stages of the decision-making process. Suggestions for future studies were made

    Exploration of decision-making regarding the transfer of mosaic embryos following preimplantation genetic testing: A qualitative study

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    STUDY QUESTION: What are patients' reasoning and decisional needs in relation to the transfer of mosaic embryos following preimplantation genetic testing (PGT)? SUMMARY ANSWER: This study identified four themes, which were patients' reasoning behind decision-making, their decisional needs, the influence of the mosaic embryos on the decision-making and the role of health professionals. WHAT IS KNOWN ALREADY: To date, no study has investigated the reasoning of patients behind their decision-making and the influence of mosaic embryos. STUDY DESIGN, SIZE, DURATION: This is a cross-sectional study using a qualitative approach. Twenty participants were interviewed, and recruitment was ceased when no new information was identified in the data analysis. It ensured a sufficient sample size for a qualitative study. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants were females with mosaic embryos. Semi-structured in-depth interviews were conducted via telephone. MAIN RESULTS AND THE ROLE OF CHANCE: Four themes were identified: Reasoning behind decision-making, decisional needs, influence of mosaic embryos on decision-making and the role of health professionals. Potential risks of transferring mosaic embryos and prioritization of euploid embryos were the main reasons for not transferring mosaic embryos. A lack of alternatives, perceived benefits and risk tolerance were main reasons for transferring mosaic embryos. Patients reported that information on mosaic embryos, amniocentesis and termination was important to support their decision-making. Unmet needs relating to healthcare services and social support were reported. In addition, having mosaic embryos affected the patients' emotional and behavioural responses, discussions about prenatal testing, attitudes to termination and further IVF cycles and attitudes towards PGT. Health professionals were found to influence the patients' decision-making. LIMITATIONS, REASONS FOR CAUTION: Participants were recruited through one clinic, which may limit the transferability of results. Also, patients' experiences in relation to financial aspects of PGT may not be relevant to other jurisdictions due to different healthcare policies. WIDER IMPLICATIONS OF THE FINDINGS: The results may inform how clinicians provide healthcare services based on factors influencing patients' decision-making. Health professionals should be aware of the influence their attitudes can have on patients' decision-making and should present information accordingly. Also, providing all relevant information may help to facilitate informed decision-making. Provision of psychological support from professionals and support groups is also critical during the process of testing and transfer. Patients have educational needs regarding mosaic embryos, and educational resources including decision aids in plain language are needed. STUDY FUNDING/COMPETING INTEREST(S): B.M. was funded through a Senior Research Fellowship Level B (ID 1078523) from the National Health and Medical Research Council of Australia. L.C. was supported by a University International Postgraduate Award under the Australian Government Research Training Program (RTP) scholarship. No other funding was received for this study. The authors report no competing interests. TRIAL REGISTRATION NUMBER: N/A

    Decisional needs of patients considering preimplantation genetic testing: a systematic review

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    This systematic review reports on the needs and sources of support in patients’ decision-making regarding the uptake of preimplantation genetic testing (PGT). Five databases were searched systematically to capture qualitative and quantitative studies. A total of 2336 studies were screened by title and abstract. Twelve studies met the eligibility criteria and reported on 4047 participants. This systematic review shows that patients need information directly relevant to PGT treatment, and information on health care relating to treatment and alternative reproductive options. Information that is too detailed, excessive and contains a large volume of medical terminology can be a barrier to decision-making. Published research suggests that health professionals provide general information on PGT and discuss it in detail only when patients require more information about it. Additionally, studies have shown that patients receive decisional support through mass media, significant persons in their lives and health professionals, whereas referring obstetricians and gynaecologists provided relatively less help compared with other health professionals. This systematic review highlights the importance of developing decision aids that meet patients’ decisional needs as indicated in previous studies and that use innovative formats to deliver information. Additionally, given rapid technical developments, a dearth of continuing professional education is available on PGT for clinicians to keep updated

    Comparison of two cadaveric acellular dermal matrices for immediate breast reconstruction: A prospective randomized trial.

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    AlloDerm RTU® and AlloMaxTM are two acellular dermal matrices (ADMs) used in implant-based breast reconstruction. In this study, we examined whether different processing methods for the ADMs lead to a disparity in histologic, clinical, and financial outcomes after breast reconstruction. Thirty patients undergoing implant-based breast reconstruction were randomized into AlloMax or AlloDerm arms (n&nbsp;=&nbsp;15, each). ADM was placed at the time of immediate reconstruction. Patients were evaluated for complications on postoperative days 7, 14, and 30. During implant exchange, ADM biopsies were taken and compared histologically for vascular and cellular infiltration. Patient satisfaction was evaluated using the BRECON-31 questionnaire 1 year after implant exchange. A cost analysis was performed comparing the two ADMs. Patient demographics and complication rates were similar between the two groups (p&nbsp;&gt;&nbsp;0.05). Histologically, vessel density and fibroblast/inflammatory cell infiltrate were greater on the dermal side than on the implant side (p&nbsp;&lt;&nbsp;0.01) in both ADMs, suggesting greater vascular and cellular in-growth from the dermal side. Vessel density in the middle portion of the Allomax biopsies was significantly higher than the same site in the Alloderm biopsies (p&nbsp;&lt;&nbsp;0.05). The extent of fibroblast/inflammatory cell infiltration was similar in both arms (p&nbsp;&gt;&nbsp;0.05). The BRECON-31 satisfaction questionnaire yielded similar responses across all metrics between the two study arms. The negotiated price was slightly different when comparing the two ADMs, with no significant difference in ADM reimbursement. In this study, AlloDerm RTU and AlloMax were successfully used for implant-based breast reconstruction with comparable outcomes

    Fractalkine signaling regulates macrophage recruitment into the cochlea and promotes the survival of spiral ganglion neurons after selective hair cell lesion

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    Macrophages are recruited into the cochlea in response to injury caused by acoustic trauma or ototoxicity, but the nature of the interaction between macrophages and the sensory structures of the inner ear remains unclear. The present study examined the role of fractalkine signaling in regulating the injury-evoked behavior of macrophages following the selective ablation of cochlear hair cells. We used a novel transgenic mouse model in which the human diphtheria toxin receptor (huDTR) is selectively expressed under the control of Pou4f3, a hair cell-specific transcription factor. Administration of diphtheria toxin (DT) to these mice resulted in nearly complete ablation of cochlear hair cells, with no evident pathology among supporting cells, spiral ganglion neurons, or cells of the cochlear lateral wall. Hair cell death led to an increase in macrophages associated with the sensory epithelium of the cochlea. Their numbers peaked at 14 days after DT and then declined at later survival times. Increased macrophages were also observed within the spiral ganglion, but their numbers remained elevated for (at least) 56 d after DT. To investigate the role of fractalkine signaling in macrophage recruitment, we crossed huDTR mice to a mouse line that lacks expression of the fractalkine receptor (CX(3)CR1). Disruption of fractalkine signaling reduced macrophage recruitment into both the sensory epithelium and spiral ganglion and also resulted in diminished survival of spiral ganglion neurons after hair cell death. Our results suggest a fractalkine-mediated interaction between macrophages and the neurons of the cochlea. SIGNIFICANCE STATEMENT It is known that damage to the inner ear leads to recruitment of inflammatory cells (macrophages), but the chemical signals that initiate this recruitment and the functions of macrophages in the damaged ear are unclear. Here we show that fractalkine signaling regulates macrophage recruitment into the cochlea and also promotes the survival of cochlear afferents after selective hair cell lesion. Because these afferent neurons carry sound information from the cochlea to the auditory brainstem, their survival is a key determinant of the success of cochlear prosthetics. Our data suggest that fractalkine signaling in the cochlea is neuroprotective, and reveal a previously uncharacterized interaction between cells of the cochlea and the innate immune system
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