bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regeneration of Vertebrate Tissues: Model Systems
Authors: Stocum David L 
Published: September 2009

Abstract

Vertebrate animals exhibit three mechanisms of tissue regeneration. The most common mechanism is the proliferation and differentiation of adult stem cells, used by epithelia, muscle, bone and blood. Urodele salamanders are able to regenerate complex structures such as limbs by the dedifferentiation of adult cells to mesenchymal stem cell‐like cells at the site of amputation. Tissue lost from the vertebrate liver regenerates by compensatory hyperplasia. The mouse pancreas also regenerates by compensatory hyperplasia. The cellular activities in all these mechanisms are regulated by a wide variety of growth factors and hormones. Regenerative medicine aims to use three strategies based on regenerative mechanisms, transplants of stem cells or their derivatives, construction of bioartificial tissues composed of natural or synthetic biomaterials seeded with cells, and the pharmaceutical induction of regeneration at the site of injury by natural or synthetic regeneration‐promoting molecules.

Key Concepts

Regeneration restores the original structure and function of damaged or missing tissues.

Tissues use three mechanisms to regenerate: adult stem cells sequestered during tissue development (epithelia, bone, muscle, blood), creation of stem cells by the dedifferentiation of differentiated cells (salamander limb regeneration) and proliferation of cells in their differentiated state (liver, pancreas).

Growth factors are important regulators of regeneration.

Regenerative medicine uses three strategies to regenerate damaged tissue: cell transplants, bioartificial tissue implants and pharmaceutical induction of regeneration directly at the site of damage by scaffolds or soluble molecules.

The source of cells for transplants and bioartificial tissues is a crucial issue for regenerative medicine. Induced pluripotent stem cells (iPSCs) may solve many of the problems presented by adult and embryonic stem cells.
Anaerobic Respiration
Authors: Oren Aharon 
Published: September 2009

Abstract

Many prokaryotes, Bacteria as well as Archaea, can obtain energy for growth in the absence of oxygen by anaerobic respiration. In this process, electrons are transferred to electron acceptors such as nitrate, sulfate, elemental sulfur, carbon dioxide, oxidized metal ions such as Fe(III) and Mn(IV) and a range of other compounds including fumarate, dimethylsulfoxide, trimethylamine
N
‐oxide, arsenate and selenate. In all these processes, respiratory electron transport is coupled to the generation of a transmembrane proton gradient and the formation of adenosine triphosphate (ATP). Anaerobic respiration processes are seldom encountered in eukaryotic organisms. Anaerobic respiration has an important impact on the cycle of matter in nature, including processes such as denitrification (dissimilatory reduction of nitrate and nitrite to gaseous nitrogen), dissimilatory sulfate reduction with the formation of sulfide, the formation of methane and acetate from carbon dioxide and different processes in the biogeochemical cycles of metals.

Key concepts

When oxygen is not available for respiration many prokaryotes can use alternative electron acceptors to obtain energy by respiration.

Anaerobic respiration is widespread in the two domains of prokaryotes: the Bacteria and the Archaea.

Some prokaryotes can perform both aerobic and anaerobic respiration; others are obligate anaerobes that cannot use oxygen as electron acceptor for respiration.

Denitrification, or dissimilatory reduction of nitrate to gaseous nitrogen, is an important process in the global nitrogen cycle.

In anaerobic environments sulfate serves as terminal electron acceptor and is reduced to sulfide, giving rise to both the formation of metal sulfides in sediments and the evolution of hydrogen sulfide gas.

Carbon dioxide is used as terminal electron acceptor by methanogenic Archaea for energy generation, yielding methane as final product and by different groups of prokaryotes to produce acetate.

Anaerobic respiration processes are involved in a wide range of reactions involving oxidized ions of metals (iron, manganese, chromium, uranium and others) and metalloids (arsenic, selenium).

Anaerobic respiration has important economic implications, both favourable (e.g. conversion of bound nitrogen to nitrogen gas in water purification plants) and unfavourable (e.g. loss of available nitrogen in agricultural soils, corrosion of steel pipes mediated by sulfate‐reducing bacteria).
Inbred Animal Strains
Authors: Kurosawa Tsutomu 
Published: September 2009

AbstractThere are four main genetic types of laboratory animal used in biomedical research animal breeding systems: inbred strains, mutant strains, closed colony and hybrid animals. An inbred strain is one created by at least 20 generations of brother–sister mating; members share a unique set of characteristics. Outbred animal strain is an antonym. The cloned animals are ultimate forms which are genetically identical. Congenic strain is produced from gene‐modified animals such as transgenic and knockout animals crossed to inbred strain for a precise analysis of modified genes. There are many disease model animals which are inbred to analyse the responsible gene of the target disease. For immunology, cancer research, transplantation technology and regenerative medicine, the usefulness of inbred animal strain is increased with the usage of embryonic stem (ES) and induced pluriopotent stem (iPS) cells. The quality control of inbred strain is made with genetic monitoring.Key ConceptInbred animal strain is part but main and key laboratory animals for fundamental biomedical research.It is produced by brother–sister mating but its ultimate form is a cloned animal in which all of the genes are identical.They are used for gene analysis and medicine as disease models.There have been many incurable diseases which are caused by gene dysfunction are now treated using the fundamental knowledge found in inbred disease model animal strains.The immunology and cancer research as fundamental medicine, and organ transplantation and regenerative medicine as modern medical technology have been advanced with its usage.The knowledge of cell therapy will be advanced with the usage of inbred animal strain.Before the application of ES and iPS cells for medical therapy, the fundamental research should be made on them.
Deafness
Authors: Terrinoni Alessandro , Melino Gerry , Serra Valeria , Alessandrini Marco , Napolitano Bianca , Bruno Ernesto 
Published: September 2009

Abstract

Recent statistical data indicate that in western countries, at least 1:1000 suffer of congenital hearing impairment. Genetic factors are responsible for more than 60% of the congenital cases. Sometimes, however, hearing loss is a multifactorial disorder caused by both genetic and environmental factors. Molecular genetics of deafness has experienced remarkable progress in the last decade. Genes responsible for hereditary hearing impairment are being mapped and cloned progressively. This article, while reporting some syndromic conditions related to deafness, focuses on nonsyndromic hearing loss. Genes involved in this type of pathologic condition have only recently begun to be identified. Owing to genetic heterogeneity, private nature of most mutations and large size of most deafness genes, the molecular diagnostic possibilities in recessive deafness are today limited only for a few genes. Facility and benefits of genetic tracking, in particular, should make it an important public health issue so that determinations of early diagnosis of hearing loss can be properly established.

Key concepts:

Deafness is the most common sensory deficit in humans, affecting 1 in 1000 new‐born, and to date more than 23 different DFNB proteins have been discovered.

DFNB proteins can be classified into two classes: (1) genes regulating potassium homeostasis and (2) genes producing proteins that are important in the formation of stereocilia.

Owing to genetic heterogeneity, the molecular diagnostic possibilities in recessive deafness are still limited. However, facility and benefits of genetic tracking should make them an important public health issue.
Terpenoids: Higher
Authors: Devarenne Timothy P 
Published: September 2009

Abstract

Terpenoids (or isoprenoids/isopentenoids) are a diverse group of compounds that are found throughout nature and are biosynthesized through the successive condensation of the five‐carbon compound isoprene. Higher terpenoids are complex structures that possess minimally between 20 and 40 carbon atoms. Although higher terpenoids are found in all organisms, plants produce the largest array of higher terpenoids in terms of number, structure and function. These plant‐derived higher terpenoids can be utilized by humans for purposes such as drugs to fight diseases or as feedstocks for biofuel production. The genes responsible for producing these plant of higher terpenoids are just now beginning to be identified and these studies are showing that higher terpenoids are essential for plant growth, development and defence against pathogens.

Key concepts:

Higher terpenoids contain at least 20 carbons and comprise many different structures and functions.

Triterpenoids originate from C
30
squalene which is directly cyclized in bacteria and oxygenated and then cyclized by eukaryotes.

Sterols are important regulators of membrane fluidity as well as the production of steroid hormones in both animals and plants.

Plants produce more higher terpenoids than any other organisms with many functions including defence against pathogens.
Macromolecular Interactions: Light Scattering
Authors: Folta‐Stogniew Ewa J 
Published: September 2009

AbstractStatic light scattering (SLS) is a spectroscopic technique for determination of molar masses (molecular weights) and radii of gyration for macromolecules in solution. Dynamic light scattering (DLS) measurement allows determination of translational diffusion coefficient and hydrodynamic radius. Measurement of molar mass from SLS experiment determines the oligomeric state and thus provides association stoichiometry for biological macromolecules such as native and modified proteins and their complexes, nucleic acids as well as phospholipid vesicles, viruses or drug delivering nanoparticles. Both static and DLS are routinely used to assess monodispersity (homogeneity with respect to molar mass or size) of protein stocks prepared for structural studies. Both homo‐ and hetero‐association of proteins can be detected and quantitatively characterized from light scattering measurements performed at various concentrations.
Berger, Hans
Authors: Borck Cornelius 
Published: September 2009

Abstract
Hans Berger (1873–1941), a German neuro‐psychiatrist, was the first to publish the human electroencephalogram, the recording of the electric activity of the human brain. The method kindled wide public interest for its alleged potential to read foreign minds. After its scientific soundness was confirmed, the method was quickly introduced in research for investigating the neuronal activity within the brain. In addition, it still is an important clinical tool, for example, for diagnosing epilepsy or other neurological conditions.
Intestinal Epithelial Cells: Immunological Aspects
Authors: Stadnyk Andrew W 
Published: September 2009

Abstract

Intestinal epithelial cells are the cell boundary between the external environment and tissues of the gastrointestinal tract. From this interface the epithelial cells have evolved processes that help guide whether inflammation or an immune response will occur in the intestines. Indeed intestinal epithelial cells are active participants in the inflammatory and immune response because they (1) secrete inflammatory mediators, including cytokines, when they detect certain microbes; (2) secrete mediators when they become detached from the basement membrane; (3) recruit and engage dendritic cells, professional antigen‐presenting cells which sample the intestinal lumen prior to presenting antigens to lymphocytes and (4) directly present antigens to T lymphocytes using a unique repertoire of molecules. Antigen presentation to lymphocytes is required for the initiation of a specific adaptive immune response, whether humoral (antibody) or cellular, and may be key to explaining many human chronic inflammatory diseases.

Key concepts

Intestinal epithelial cells form a monolayer of cells that define the boundary between tissues of the intestine and the external environment.

From this point of interface, intestinal epithelial cells receive and interpret insults/assaults from the intestinal lumen and signal to the tissues whether inflammation will ensue.

Intestinal epithelial cells communicate through the secretion of protein and glycoprotein mediators, some of which launch the inflammatory response including by recruiting leucocytes into the tissues.

Intestinal epithelial cells interact with and control lymphocyte activation using specialized molecules, some of which are used in antigen presentation.

Antigen presentation to lymphocytes is critical to launching the adaptive (humoral and cellular) immune responses.

Antigen presentation by intestinal epithelial cells most commonly results in the inhibition of activation of T lymphocytes, including CD8+ T lymphocytes.
Apoptosis: Inherited Disorders
Authors: Su Helen C , Lenardo Michael J 
Published: September 2009

AbstractApoptosis is a mechanism of programmed cell death used in organ remodelling during development and for eliminating unnecessary or dangerous cells. In the immune system, apoptosis maintains homeostasis by limiting lymphocyte responses. Genetic defects in apoptosis leads to disturbed lymphocyte homeostasis and, potentially, autoimmunity or neoplasia. An important apoptosis disorder in humans involves the death receptor Fas. However, recently, disorders in the apoptosis pathways triggered by trophic factor withdrawal ordeoxyribonucleic acid(DNA) damage have also been described. Dual roles of certain molecules for both apoptotic and normal nonapoptotic lymphocyte function can account for combined apoptosis and immunodeficiency disorders.Key conceptsLymphocytes undergo propriocidal regulation, in which the cells that are actively proliferating are most susceptible to programmed cell death. This form of negative regulation limits the maximal intensity of immune responses and establishes the basal state of homeostasis after an immune response.Apoptosis occurs when T lymphocytes become activated to express death receptors, undergo repeated antigenic stimulation through the T‐cell receptor, or cease to produce growth factors such as IL‐2. Apoptotic pathways stimulated by death receptors, and those stimulated by intracellular derangements, are both utilized.Mice and humans who have defective apoptosis display progressive accumulation of lymphocytes, systemic autoimmunity and a predisposition to lymphoid malignancy.Most genetic lesions responsible for the prototypical disease in humans, autoimmune lymphoproliferative syndrome (ALPS), involve the Fas death receptor that mediates extrinsic apoptosis. ALPS can also result from a mutation in NRAS that impairs Bim‐mediated apoptosis during cytokine deprivation.Humans with caspase‐8 or SH2D1A (SAP) deficiencies have lymphoproliferative disease and immunodeficiency, illustrating the dual roles of these molecules for lymphocyte apoptosis and nonapoptotic lymphocyte function.p53 mutations responsible for cancer susceptibility in the Li–Fraumeni syndrome impair genotoxic stress‐induced apoptosis, through effects on Puma and other Bcl‐2 family members.
‘Race’,
IQ
and Genes
Authors: Carson Michael , Beckwith Jon 
Published: September 2009

Abstract

Dominant social classes have often used scientific arguments to explain their privileged status. With the development of intelligence quotient (IQ) tests and the founding of the field of genetics, some researchers explained racial differences in behaviours such as IQ test performance as due to genetic differences. Recent discoveries in molecular genetics have provided evidence that human variation at the
deoxyribonucleic acid
(DNA) level is slight; much more variation exists within the members of any single group than between two different population groups. However, as the DNA of populations worldwide has been further characterized, some have assumed that racial differences in intelligence or other social behaviours can be ascribed to those slight interracial genetic differences. Scientists must remain vigilant and expose misrepresentations of scientific data that overemphasize the genetics of group differences and that support genetically deterministic explanations for complex behaviours, such as intelligence.

Key Concepts

Science, through measurements of brain size and IQ test scores, has been misused to support the idea of presumed racial hierarchies in intelligence.

The search for gene variants associated with complex behavioural traits, including intelligence, has been largely unsuccessful.

Environment plays a major role in the manifestation of most genetic traits.

Recent discoveries in molecular genetics have shown that most of the genetic variation that is found among human beings around the world is found in all racial and ethnic groups and only a small amount is found in specific groups.

Using large numbers of genetic variants that differ only slightly in proportion between population groups, researchers can assort individuals into major continental geographic clusters with a high degree of accuracy.

Aside from a small fraction of genes influencing apparent, visible physical features distinguishing people, the distribution of genetic variation does not support a biological basis for the concept of human races.

Preliminary and faulty scientific studies on issues relating to race and intelligence are often rapidly and unjustifiably translated into calls for changes in social policy.

Scientists have a responsibility to help ensure that studies on the genetics of group differences are not misused and misrepresented to support racist theories regarding human behaviours.
Genetic Counselling for Muslim Families of Pakistani and Bangladeshi Origin in Britain
Authors: Shaw Alison 
Published: September 2009

AbstractAn elevated risk of recessive conditions associated with the practice of consanguineous marriage may be relevant for some couples of Pakistani and Bangladeshi Muslim origin, but counsellors need to avoid stigmatizing couples who are consanguineous and should focus instead on establishing risk and strategies for risk management. Patients' prior understandings of illness causality, inheritance and risk; their religious beliefs; their language use and aspects of their family structure may also influence their access to and use of genetic information in important ways. However, these factors are not static markers of ‘ethnic’ or ‘cultural’ difference but are subject to continual negotiation within and between families and their significance varies from case to case. Genetic counsellors need to be aware of the range of ideas that patients may bring to a genetics consultation, without presuming that any particular set of ideas will apply in any given case.Key conceptsAn effective counselling service for British Pakistani and Bangladeshi Muslim families should avoid giving undue negative emphasis to cousin marriages.Genetic counsellors should be sensitive to the range of understandings of illness causality and inheritance that patients may bring to a genetics consultation.A patient's gender, status and position in their family can influence their access to and interpretation of genetic risk information.Genetic counsellors should avoid stereotyping Muslim patients and be sensitive to the range of personal and religious considerations involved in the use of medical technologies in pregnancy.Access to services would be improved by employing appropriately trained bilingual genetic professionals and interpreters.
Molecular Genetics of Predisposition to Respiratory Disorders in Newborn
Authors: Tulassay Tivadar , Treszl Andras , Vasarhelyi Barna 
Published: September 2009

Abstract

During the perinatal period, preterm neonates face severe complications. These include disorders of the lung such as respiratory distress syndrome and chronic lung disease. The risk of complications depends on maturity, but data also suggest the existence of an inherited susceptibility. This may be due to genetic polymorphisms and inherited mutations. Reported associations between lung disease and polymorphisms of genes encoding proteins that regulate inflammation, vasoregulation and lung development helped the identification of specific genetic elements in perinatal respiratory disorders. In a minority of newborns inherited mutations such as those of surfactant protein encoding gene may be responsible for the development of perinatal lung disorders. Further studies are required to assess those genetic patterns that can be used for the identification of patients at risk.

Key concepts:

Perinatal respiratory disorders affect primarily preterm infants.

These include idiopathic respiratory disorder, bronchopulmonary dysplasia.

Inherited genetic polymorphisms may be a risk factor of these complications.

Genetic polymorphisms with an impact on immune response, vasoregulation and lung development are extensively tested.

Several associations between polymorphisms and disease were reported.

Other data support the contribution of genetics to other perinatal complications that are risk factors for respiratory disorders.

Rare mutations may also cause perinatal lung disorders in some infants.

One day the results of these studies may serve as a basis for individualized therapy and risk assessment; currently we are far from this goal.
History of the Electron Microscope in Cell Biology
Authors: Masters Barry R 
Published: September 2009

AbstractIn the years following World War II there was an explosion in the biological sciences with the rapid emergence of cell biology, molecular biology and biophysics. These events were affected by the development and use of new technologies for cellular fractionation and imaging, specifically the electron microscope, which provided a resolution, that is, unobtainable with light microscopes. Electron microscopes made visible the fine structure of cells and their organelles, the structure of viruses. Now cryo‐electron microscopy is emerging as a key tool to visualize and localize the proteins in an entire cell, the organization of actin filaments in the cytoskeleton, and molecular complexes such as nuclear pores.