78 research outputs found

    Folded conformations of antigenic peptides from riboflavin carrier protein in aqueous hexafluoroacetone

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    Riboflavin carrier protein (RCP) plays an important role in transporting vitamin B2 across placental membranes, a process critical for maintenance of pregnancy. Association of the vitamin with the carrier protein ensures optimal bioavailability, facilitating transport. The conformations of three antigenic peptide fragments encompassing residues 4-23 (N21), 170-186 (R18), and 200-219 (Y21) from RCP, which have earlier been studied as potential leads toward a synthetic peptide-based contraceptive vaccine, have been investigated using CD and NMR spectroscopy in aqueous solution and in the presence of the structure-stabilizing cosolvent hexafluoroacetone trihydrate (HFA). In aqueous solution at pH 3.0, all three peptides are largely unstructured, with limited helical population for the peptides R18 and Y21. The percentage of helicity estimated from CD experiments is 10% for both the peptides. A dramatic structural transition from an unstructured state to a helical state is achieved with addition of HFA, as evidenced by intensification of CD bands at 222 nm and 208 nm for Y21 and R18. The structural transition is completed at 50% HFA (v/v) with 40% and 35% helicity for R18 and Y21, respectively. No structural change is evident for the peptide N21, even in the presence of HFA. NMR analysis of the three peptides in 50% HFA confirms a helical conformation of R18 and Y21, as is evident from upfield shifts of CαH resonances and the presence of many sequential NH/NH NOEs with many medium-range NOEs. The helical conformation is well established at the center of the sequence, with substantial fraying at the termini for both the peptides. An extended conformation is suggested for the N21 peptide from NMR studies. The helical region of both the peptides (R18, Y21) comprises the core epitopic sequence recognized by the respective monoclonal antibodies. These results shed some light on the issue of structure and folding of antigenic peptides

    Early prepubertal cyclophosphamide exposure in mice results in long-term loss of ovarian reserve, and impaired embryonic development and blastocyst quality.

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    BackgroundDue to improved treatment, there is an increasing focus on the reproductive potential of survivors of childhood cancer. Cytotoxic chemotherapy accelerates the decline in the number of primordial follicles within the mammalian ovary at all ages, but effects on the developmental potential of remaining oocytes following prepubertal cancer treatment are unclear.ObjectivesTo investigate whether cyclophosphamide (CY) exposure in the prepubertal period in female mice influences ovarian function and the functional competence of oocytes in adulthood.MethodsThis study used Swiss albino mice as the experimental model. Female mice were treated with 200 mg/kg CY on either postnatal day 14 (CY14), 21 (CY21) or 28 (CY28) i.e at a prepubertal and 2 young postpubertal ages. At 14 weeks of life, ovarian function, functional competence of oocytes, and embryo quality were assessed.ResultsThe number of primordial follicles decreased significantly in CY14 and CY21 groups compared to control (p ConclusionOur results indicate long-term effects on the developmental competence of oocytes exposed to CY in early but not adult life. These data provide a mechanism whereby long-term fertility can be impaired after chemotherapy exposure, despite the continuing presence of follicles within the ovary, and support the need for fertility preservation in prepubertal girls before alkylating agent exposure

    Oncofertility awareness among primary care physicians in India [version 1; peer review: 2 approved, 1 not approved]

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    Background: Primary care physicians not only coordinate referrals to oncology services but can play a crucial role in successful fertility preservation referrals in cancer-diagnosed patients. Hence, it is important to assess their knowledge and attitudes towards fertility preservation. Methods: An eighteen-item oncofertility survey was administered to primary care physicians between May 2019 to September 2020.  Results: A total of forty-six responses were received and analysed. About 60% of primary care physicians did not have adequate knowledge about available fertility preservation options and only 26-32% were aware of international guidelines recommending fertility preservation in cancer patients.  Conclusions: Imparting awareness and knowledge of fertility preservation and its options to primary care physicians could enable an integrated cancer care model while also facilitating successful oncofertility referrals in countries like India

    Oncofertility awareness among primary care physicians in India [version 2; peer review: 2 approved, 1 not approved]

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    Background: Primary care physicians not only coordinate referrals to oncology services but can play a crucial role in successful fertility preservation referrals in cancer-diagnosed patients. Hence, it is important to assess their knowledge and attitudes towards fertility preservation. Methods: An eighteen-item oncofertility survey was administered to primary care physicians between May 2019 to September 2020.  Results: A total of forty-six responses were received and analysed. About 60% of primary care physicians did not have adequate knowledge about available fertility preservation options and only 26-32% were aware of international guidelines recommending fertility preservation in cancer patients.  Conclusions: Imparting awareness and knowledge of fertility preservation and its options to primary care physicians could enable an integrated cancer care model while also facilitating successful oncofertility referrals in countries like India

    A survey of fertility preservation options available to cancer patients around the globe

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    Purpose: Oncofertility focuses on providing fertility and endocrine-sparing options to patients who undergo life-preserving but gonadotoxic cancer treatment. The resources needed to meet patient demand often are fragmented along disciplinary lines. We quantify assets and gaps in oncofertility care on a global scale. Methods: Survey-based questionnaires were provided to 191 members of the Oncofertility Consortium Global Partners Network, a National Institutes of Health–funded organization. Responses were analyzed to measure trends and regional subtleties about patient oncofertility experiences and to analyze barriers to care at sites that provide oncofertility services. Results: Sixty-three responses were received (response rate, 25%), and 40 were analyzed from oncofertility centers in 28 countries. Thirty of 40 survey results (75%) showed that formal referral processes and psychological care are provided to patients at the majority of sites. Fourteen of 23 respondents (61%) stated that some fertility preservation services are not offered because of cultural and legal barriers. The growth of oncofertility and its capacity to improve the lives of cancer survivors around the globe relies on concentrated efforts to increase awareness, promote collaboration, share best practices, and advocate for research funding. Conclusion: This survey reveals global and regional successes and challenges and provides insight into what is needed to advance the field and make the discussion of fertility preservation and endocrine health a standard component of the cancer treatment plan. As the field of oncofertility continues to develop around the globe, regular assessment of both international and regional barriers to quality care must continue to guide process improvements

    Survey of Third-Party Parenting Options Associated With Fertility Preservation Available to Patients With Cancer Around the Globe

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    Purpose: In the accompanying article, “Analysis of Fertility Preservation Options Available to Patients With Cancer Around the Globe,” we showed that specific fertility preservation services may not be offered at various sites around the world because of cultural and legal barriers. We assessed global and regional experiences as well as the legal status of third-party reproduction and adoption to serve as a comprehensive international data set and resource for groups that wish to begin oncofertility interventions. Methods: We provide data on the legalities of third-party assisted reproductive technologies and other family-building options in the 28 oncofertility-practicing countries surveyed. Results: We found regional and country differences that will be important in the development of tailored resources for physicians and for patient brochures that are sensitive to these local restrictions and cultural norms. Conclusion: Because many patients first consult Web-based materials, the formal assessment of the availability of these options provides members of the global oncofertility community with data to which they might otherwise not have ready access to better serve their patients

    Survey of third-party parenting options associated with fertility preservation available to patients with cancer around the globe

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    bstract PURPOSE In the accompanying article, “Survey of Fertility Preservation Options Available to Patients With Cancer Around the Globe,” we showed that specific fertility preservation services may not be offered at various sites around the world because of cultural and legal barriers. We assessed global and regional experiences as well as the legal status of third-party reproduction and adoption to serve as a comprehensive international data set and resource for groups that wish to begin oncofertility interventions. METHODS We provide data on the legalities of third-party assisted reproductive technologies and other familybuilding options in the 28 oncofertility-practicing countries surveyed. RESULTS We found regional and country differences that will be important in the development of tailored resources for physicians and for patient brochures that are sensitive to these local restrictions and cultural norms. CONCLUSION Because many patients first consult Web-based materials, the formal assessment of the availability of these options provides members of the global oncofertility community with data to which they might otherwise not have ready access to better serve their patients

    Advancing or postponing the day of human chorionic gonadotropin does not matter for the outcome in assisted reproductive technology

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    Context : The primary outcome is to remove the worry of getting immature oocytes with early administration of human chorionic gonadotropin (hCG). Aim : The aim was to find out the association between the day of hCG administration and follicular response in relation to the number and maturity of oocytes, and fertilization rate in assisted reproduction to avoid weekend oocyte recovery (OR). Settings and Design : Retrospective study was carried out in the university infertility clinic. Materials and Method : Controlled ovarian hyperstimulation (COH) in 94 patients undergoing assisted reproductive technology (2010-2011) with recombinant follicle stimulating hormone and timely gonadotropin-releasing hormone antagonist were analyzed regarding day of hCG from day 8-11. Oocyte maturity and fertilization was analyzed and correlated with the day of hCG administration. STATISTICAL ANALYSIS: Kruskal-Wallis test. Results : The average number of >18 mm follicles observed from day 8-11 of hCG administration was not statistically different. However, the OR rate (54.2%), number of mature oocytes (92.5%), and fertilization rate (78.5%) was maximum in the patients where hCG was administered on day 8 of COH. Conclusions : The day of hCG administration between 8 and 11 does not affect the OR rate significantly although the number of oocytes recovered on day 8 are marginally higher compared with day 9-11. Hence, it is possible to safely avoid weekend oocyte retrieval, by delaying or advancing hCG administration without compromising the outcome
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