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Cryopreservation Of Testicular Tissue
Cryopreservation of testicular tissue is an experimental method being used to preserve fertility in pre-pubescent males, or males who cannot produce sperm, to allow them the option of having biological children. Current first line treatment for fertility maintenance in men undergoing treatment which damages testicular tissue is cryopreservation of sperm. In boys yet to start producing sperm this is not possible, so cryopreservation of testicular tissue has been proposed as alternative therapy. This method is still experimental and not widely clinically available, and how to restore fertility with cryopreserved tissue is unknown and experimental. Indications One cause of infertility in males is the medical treatment used to treat cancer (chemotherapy or radiotherapy), as it can have a toxic effect on the sperm producing tissue in the testes. For prepubertal boys undergoing cancer treatment who haven’t yet begun producing sperm, preservation of sperm itself is not an option. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fertility
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertility is addressed when there is a difficulty or an inability to reproduce naturally, which is referred to as infertility. Infertility is widespread, with fertility specialists available all over the world to assist mothers and couples who experience difficulties having a baby. Human fertility depends on factors of nutrition, sexual behaviour, consanguinity, culture, instinct, endocrinology, timing, economics, personality, way of life, and emotions. Fertility differs from fecundity, which is defined as the ''potential'' for reproduction (influenced by gamete production, fertilization and carrying a pregnancy to term). Where a woman or the lack of fertility is infertility while a lack of fecundity would be called sterility. Demography I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vitrification
Vitrification (from Latin ''vitreum'', "glass" via French ''vitrifier'') is the full or partial transformation of a substance into a glass, that is to say, a non-crystalline amorphous solid. Glasses differ from liquids structurally and glasses possess a higher degree of connectivity with the same Hausdorff dimensionality of bonds as crystals: dimH = 3. In the production of ceramics, vitrification is responsible for its impermeability to water. Vitrification is usually achieved by heating materials until they liquidize, then cooling the liquid, often rapidly, so that it passes through the glass transition to form a glassy solid. Certain chemical reactions also result in glasses. In terms of chemistry, vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles (atoms, molecules, forming blocks) becomes higher than a certain threshold value. Thermal fluctuations break the bonds; therefore, the low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematologic Disease
Hematologic diseases are disorders which primarily affect the blood & Blood formation, blood-forming organs. Hematologic diseases include rare genetic disorders, anemia, HIV, sickle cell disease & complications from chemotherapy or transfusions. Myeloid * Hemoglobinopathy, Hemoglobinopathies (congenital abnormality of the hemoglobin molecule or of the rate of hemoglobin synthesis) ** Sickle cell disease ** Thalassemia ** Methemoglobinemia * Anemias (lack of red blood cells or hemoglobin) ** Iron-deficiency anemia ** Megaloblastic anemia *** Vitamin B12, Vitamin B12 deficiency **** Pernicious anemia *** Folate deficiency ** Hemolytic anemias (destruction of red blood cells) *** Genetic disorders of RBC membrane **** Hereditary spherocytosis **** Hereditary elliptocytosis **** Congenital dyserythropoietic anemia *** Genetic disorders of RBC metabolism **** Glucose-6-phosphate dehydrogenase deficiency (G6PD) **** Pyruvate kinase deficiency *** Immune mediated hemolytic anemia (Coombs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grafting
Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The success of this joining requires that the vascular tissues grow together and such joining is called inosculation. The technique is most commonly used in asexual propagation of commercially grown plants for the horticultural and agricultural trades. In most cases, one plant is selected for its roots and this is called the stock or rootstock. The other plant is selected for its stems, leaves, flowers, or fruits and is called the scion or cion. The scion contains the desired genes to be duplicated in future production by the stock/scion plant. In stem grafting, a common grafting method, a shoot of a selected, desired plant cultivar is grafted onto the stock of another type. In another common form called bud grafting, a dormant side bud is gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro Spermatogenesis
In vitro spermatogenesis is the process of creating male gametes (spermatozoa) outside of the body in a culture system. The process could be useful for fertility preservation, infertility treatment and may further develop the understanding of spermatogenesis at the cellular and molecular level. Spermatogenesis is a highly complex process and artificially rebuilding it ''in vitro'' is challenging. These include creating a similar microenvironment to that of the testis as well as supporting endocrine and paracrine signalling, and ensuring survival of the somatic and germ cells from spermatogonial stem cells (SSCs) to mature spermatozoa. Different methods of culturing can be used in the process such as isolated cell cultures, fragment cultures and 3D cultures Culture techniques Isolated cell cultures Cell cultures can include either monocultures, where one cell population is cultured, or co-culturing systems, where several cell lines (must be at least two) can be cultured t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Ethics
Medical ethics is an applied branch of ethics which analyzes the practice of clinical medicine and related scientific research. Medical ethics is based on a set of values that professionals can refer to in the case of any confusion or conflict. These values include the respect for autonomy, non-maleficence, beneficence, and justice. Such tenets may allow doctors, care providers, and families to create a treatment plan and work towards the same common goal. It is important to note that these four values are not ranked in order of importance or relevance and that they all encompass values pertaining to medical ethics. However, a conflict may arise leading to the need for hierarchy in an ethical system, such that some moral elements overrule others with the purpose of applying the best moral judgement to a difficult medical situation. Medical ethics is particularly relevant in decisions regarding involuntary treatment and involuntary commitment. There are several codes of conduct. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methylation
In the chemical sciences, methylation denotes the addition of a methyl group on a substrate, or the substitution of an atom (or group) by a methyl group. Methylation is a form of alkylation, with a methyl group replacing a hydrogen atom. These terms are commonly used in chemistry, biochemistry, soil science, and the biological sciences. In biological systems, methylation is catalyzed by enzymes; such methylation can be involved in modification of heavy metals, regulation of gene expression, regulation of protein function, and RNA processing. In vitro methylation of tissue samples is also one method for reducing certain histological staining artifacts. The reverse of methylation is demethylation. In biology In biological systems, methylation is accomplished by enzymes. Methylation can modify heavy metals, regulate gene expression, RNA processing and protein function. It has been recognized as a key process underlying epigenetics. Methanogenesis Methanogenesis, the process th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetics
In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance. Epigenetics most often involves changes that affect the regulation of gene expression, but the term can also be used to describe any heritable phenotypic change. Such effects on cellular and physiological phenotypic traits may result from external or environmental factors, or be part of normal development. The term also refers to the mechanism of changes: functionally relevant alterations to the genome that do not involve mutation of the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene expression c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ Transplantation
Organ transplantation is a medical procedure in which an organ (anatomy), organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organs may be transported from a Organ donation, donor site to another location. Organ (anatomy), Organs and/or Tissue (biology), tissues that are transplanted within the same person's body are called autografts. Transplants that are recently performed between two subjects of the same species are called allografts. Allografts can either be from a living or cadaveric source. Organs that have been successfully transplanted include the Heart transplantation, heart, Kidney transplantation, kidneys, Liver transplantation, liver, Lung transplantation, lungs, Pancreas transplantation, pancreas, Intestinal transplant, intestine, Thymus transplantation, thymus and uterus transplantation, uterus. Tissues include Bone grafting, bones, tendons (both referr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malignant Cells
Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not self-limited in its growth, is capable of invading into adjacent tissues, and may be capable of spreading to distant tissues. A benign tumor has none of those properties. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis. Malignant tumors are also characterized by genome instability, so that cancers, as assessed by whole genome sequencing, frequently have between 10,000 and 100,000 mutations in their entire genomes. Cancers usually show tumour heterogeneity, containing multiple subclones. They also frequently have reduced expression of DNA repair enzymes due to epigenetic methylation of DNA repair genes or altered microRNAs that control DNA repair gene expression. Tumours can be detected through the vis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biopsy
A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a disease. The tissue is then fixed, dehydrated, embedded, sectioned, stained and mounted before it is generally examined under a microscope by a pathologist; it may also be analyzed chemically. When an entire lump or suspicious area is removed, the procedure is called an excisional biopsy. An incisional biopsy or core biopsy samples a portion of the abnormal tissue without attempting to remove the entire lesion or tumor. When a sample of tissue or fluid is removed with a needle in such a way that cells are removed without preserving the histological architecture of the tissue cells, the procedure is called a needle aspiration biopsy. Biopsies are most commonly performed for insight into possible cancerous or inflammatory conditions. History T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slow Programmable Freezing
Cryo-preservation or cryo-conservation is a process where organisms, organelles, cells, tissues, extracellular matrix, organs, or any other biological constructs susceptible to damage caused by unregulated chemical kinetics are preserved by cooling to very low temperatures (typically using solid carbon dioxide or using liquid nitrogen). At low enough temperatures, any enzymatic or chemical activity which might cause damage to the biological material in question is effectively stopped. Cryopreservation methods seek to reach low temperatures without causing additional damage caused by the formation of ice crystals during freezing. Traditional cryopreservation has relied on coating the material to be frozen with a class of molecules termed cryoprotectants. New methods are being investigated due to the inherent toxicity of many cryoprotectants. Cryoconservation of animal genetic resources is done with the intention of conservation of the breed. Natural cryopreservation Tardi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
