scholarly journals Collagen-based materials in reproductive medicine and engineered reproductive tissues

2022 ◽  
Vol 4 (1) ◽  
Author(s):  
Hanxiao Chen ◽  
Luqi Xue ◽  
Guidong Gong ◽  
Jiezhou Pan ◽  
Xiaoling Wang ◽  
...  

AbstractCollagen, the main component of mammal skin, has been traditionally used in leather manufacturing for thousands of years due to its diverse physicochemical properties. Collagen is the most abundant protein in mammals and the main component of the extracellular matrix (ECM). The properties of collagen also make it an ideal building block for the engineering of materials for a range of biomedical applications. Reproductive medicine, especially human fertility preservation strategies and reproductive organ regeneration, has attracted significant attention in recent years as it is key in resolving the growing social concern over aging populations worldwide. Collagen-based biomaterials such as collagen hydrogels, decellularized ECM (dECM), and bioengineering techniques including collagen-based 3D bioprinting have facilitated the engineering of reproductive tissues. This review summarizes the recent progress in applying collagen-based biomaterials in reproductive. Furthermore, we discuss the prospects of collagen-based materials for engineering artificial reproductive tissues, hormone replacement therapy, and reproductive organ reconstruction, aiming to inspire new thoughts and advancements in engineered reproductive tissues research. Graphical abstract

2021 ◽  
Author(s):  
Ayumu Ito ◽  
Yukiko Katagiri ◽  
Yusuke Fukuda ◽  
Mineto Morita

AbstractObjectiveRecent advances in cancer treatment and reproductive medicine have made the post-treatment quality of life an important concern for cancer survivors. We aimed to evaluate the safety of sex hormone (estradiol and progesterone) replacement therapy (HRT) in women who conceived by assisted reproductive technology (ART) with hormone receptor-positive breast cancer.MethodsWe measured serum E2 and P4 levels at 4–10 weeks of gestation in women who conceived naturally or after timed intercourse or intrauterine insemination for infertility without HRT for luteal support (non-HR group; n=135). We conducted a retrospective comparison of the values from the non-HR group with those of women who conceived by ART with HRT for infertility (HR group; n=75).ResultsSerum E2 levels were significantly higher in the non-HR group than in the HR group at 5, 6, and 8 weeks of gestation. Similarly, serum P4 levels were significantly higher in the non-HR group than in the HR group at 4, 5, and 6 weeks of gestation.ConclusionsThis study suggests that in cancer reproductive medicine for hormone-dependent breast cancer survivors, HRT administered during the first trimester of a pregnancy after primary disease treatment may not increase the sex hormone levels to levels above those seen in spontaneous pregnancy.


2017 ◽  
Vol 12 (4) ◽  
pp. 184-191
Author(s):  
Mihaela Daniela BALTĂ ◽  
◽  
Mihaela Adela IANCU ◽  
Dumitru MATEI ◽  
◽  
...  

Osteoporosis is a disease that affects an increasing number of people, given the tendency of aging populations. Fragile bone and increases risk of bones breaking, their consequences, impairment of quality of life have prompted health policies to provide a greater insight into this condition. It is important to identify the risk factors and start the preventive and curative treatment as early as possible. Current guidelines recommend using the FRAX score to determine the risk of major fracture over the next 10 years, followed by DXA determination. The current guidelines highlight the importance of non-medication measures, calcium and vitamin D intake. Among the therapeutic agents used in the treatment of osteoporosis, the first line are bisphosphonates poor, in case of intolerance, bisphosphonates iv or antibodies anti RANKL (denosumab). Selective estrogen receptor modulators and hormone replacement therapy are not routinely indicated, and recombinant PTH is expensive and is intended for severe and resistant forms. The adherence to treatment is poor, so we need measures to increase prevention, screening and early treatment of osteoporosis, as well as measures to educate the population.


2017 ◽  
Author(s):  
Sigeto Tanaka

In the early 2010s, Japanese society recognized and experienced a panic about increasing infertility and people's lack of knowledge about human reproduction. This paper focuses on several graphs that misrepresented or distorted scientific findings that were used in the campaign related to this panic and explores (1) how the graphs were made, used, and authorized, and (2) how they contributed to changes in discourses and policies. Findings are the following: (1) The graphs were made in the field of obstetrics, gynecology, and reproductive medicine by questionable methods, including falsifying, trimming, and misunderstanding of data. (2) Researchers in the field of fertility study relied on secondary and tertiary sources thus ignoring and compounding errors. (3) Such inauthentic research was approved and politically mobilized by professional organizations, rather than being penalized or criticized. (4) Discourse based on such unscientific knowledge may have encouraged a pronatalist policy of promoting early marriage and education about human fertility and life planning, targeted at teenage girls.


2004 ◽  
Vol 16 (9) ◽  
pp. 158
Author(s):  
K. L. Britt ◽  
E. R. Simpson ◽  
J. K. Findlay

Phytoestrogens can induce both estrogen agonistic and antagonistic effects, depending on the tissue, estrogen receptor content and endogenous levels of estrogen. Dietary phytoestrogens are promoted as alternatives to synthetic estrogens for hormone replacement therapy, however their effects on the reproductive axis have not been exhaustively studied in vivo. Female aromatase knockout mouse (ArKO) mice are estrogen-free, and anovulatory with a block in folliculogenesis, hemorrhagic cysts and development of Sertoli cells within their ovaries. We evaluated the ArKO mouse as a model to test the effects of phytoestrogen-supplemented diets on the reproductive organ weights, ovarian morphology, gonadotropin levels and the transcript levels of ovarian somatic cell and steroidogenic markers. The extent to which phytoestrogens either as soyfree or soymeal diet or genistein added to a soyfree diet, exert estrogenic effects varied with the type of phytoestrogen and the parameter being tested. The genistein diet significantly increased uterine and ovarian weights of ArKO compared to wildtype mice, whilst both the soy, and to a larger extent the genistein diet, improved ovarian morphology compared to the soyfree diet. Transformation to morphological Sertoli cells in ArKO mice was decreased by both phytoestrogen diets, whilst the gene expression of Sertoli cell markers was not affected. The soy diet increased both LH and FSH in both genotypes compared to animals on the soyfree diet. The genistein diet reduced FSH levels in ArKO mice, correlating with increased ovarian inhibin subunit expression. In conclusion, phytoestrogens are estrogenic in ArKO mice. Specifically, they can affect serum gonadotropin levels, and offset the development of Sertoli cells and hemorrhagic cysts within the ovaries, depending on the type of dietary phytoestrogen. Further studies are required to determine the effective doses and treatment regimes for phytoestrogens as endocrine modulators. Supported by NH&MRC Reg Key#198705.


Author(s):  
Jorge Perdigao

In 1955, Buonocore introduced the etching of enamel with phosphoric acid. Bonding to enamel was created by mechanical interlocking of resin tags with enamel prisms. Enamel is an inert tissue whose main component is hydroxyapatite (98% by weight). Conversely, dentin is a wet living tissue crossed by tubules containing cellular extensions of the dental pulp. Dentin consists of 18% of organic material, primarily collagen. Several generations of dentin bonding systems (DBS) have been studied in the last 20 years. The dentin bond strengths associated with these DBS have been constantly lower than the enamel bond strengths. Recently, a new generation of DBS has been described. They are applied in three steps: an acid agent on enamel and dentin (total etch technique), two mixed primers and a bonding agent based on a methacrylate resin. They are supposed to bond composite resin to wet dentin through dentin organic component, forming a peculiar blended structure that is part tooth and part resin: the hybrid layer.


2019 ◽  
Vol 4 (4) ◽  
pp. 607-614
Author(s):  
Jean Abitbol

The purpose of this article is to update the management of the treatment of the female voice at perimenopause and menopause. Voice and hormones—these are 2 words that clash, meet, and harmonize. If we are to solve this inquiry, we shall inevitably have to understand the hormones, their impact, and the scars of time. The endocrine effects on laryngeal structures are numerous: The actions of estrogens and progesterone produce modification of glandular secretions. Low dose of androgens are secreted principally by the adrenal cortex, but they are also secreted by the ovaries. Their effect may increase the low pitch and decease the high pitch of the voice at menopause due to important diminution of estrogens and the privation of progesterone. The menopausal voice syndrome presents clinical signs, which we will describe. I consider menopausal patients to fit into 2 broad types: the “Modigliani” types, rather thin and slender with little adipose tissue, and the “Rubens” types, with a rounded figure with more fat cells. Androgen derivatives are transformed to estrogens in fat cells. Hormonal replacement therapy should be carefully considered in the context of premenopausal symptom severity as alternative medicine. Hippocrates: “Your diet is your first medicine.”


2000 ◽  
Vol 35 (3-4) ◽  
pp. 134-141 ◽  
Author(s):  
R Ivell ◽  
A-R Fuchs ◽  
R Bathgate ◽  
G Tillmann ◽  
T Kimura

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