Search

Chapter 8 of the book "Why Icebergs Float: Exploring Science in Everyday Life," by Andrew Morris is presented. Topics discussed include the basic mode of action and related processes of hormones, the personal and immediate effects of hormones in the daily life of individuals, and the hormone levels and control mechanisms.

An introduction to the book is presented which discusses scientific topics including tidal flow, structure of molecules, and hormones.

Drug-induced diarrhea (DID) is common, but our understanding of the underlying mechanisms may vary from solid understanding to reasonable hypothesis to considerable conjecture. Drug-induced diarrhea is rarely an allergy, i.e., with an underlying immune mechanism, but may well be an inherent component of the pharmacologic effect of the drug, may be due to variable pharmacogenomics or be an appropriate physiologic response to the drug. Frequently, discussions of DID become lists. However, by classifying chronic diarrhea as watery, fatty, or inflammatory, one can create a framework to better understand the mechanisms of the diarrhea. In this chapter, we examine diet, laxatives, neuromodulators, diabetes medications, chemotherapy, antibiotics, HIV medications, non-steroidals, and GI medications with an emphasis on clinical relevance and underlying mechanisms in causing diarrhea. [ABSTRACT FROM AUTHOR]

Eating disorders and disordered eating symptoms are clearly heritable, but recent research has suggested that genetic and environmental influences on disordered eating symptoms vary as a function of gender and development. Data are limited, but evidence suggests that gender may moderate the type of genetic risk, rather than the magnitude of genetic effects, on disordered eating symptoms. Only a moderate proportion of the genetic influences on disordered eating symptoms are shared between males and females. In females, at least some of the unique genetic risk may be related to puberty and ovarian hormone regulation. The heritability of disordered eating symptoms in females increases with both pubertal development and increasing levels of estradiol. Although much more research is needed to elucidate specific mechanisms, gonadal hormones may be promising candidates for understanding sex and developmental effects and the ways in which genes exert their influence on disordered eating. [ABSTRACT FROM AUTHOR]

Some of the most serious consequences of ageing are its effects on skeletal muscle. `Sarcopenia΄ involves a progressive age-related loss of muscle mass and associated muscle weakness that renders frail elders susceptible to serious injury from sudden falls and fractures and losing their functional independence. Not surprisingly, sarcopenia is a significant global public health problem, especially in the developed world. There is an urgent need to better understand the mechanisms underlying age-related muscle wasting and to develop therapeutic strategies that can attenuate, prevent, or ultimately reverse skeletal muscle wasting and weakness. Research and development in academic and research institutions and in large and small pharma is being directed to sarcopenia and related issues to develop and evaluate novel therapies. This book provides the latest information on sarcopenia from leading international researchers studying the cellular and molecular mechanisms underlying age-related changes in skeletal muscle and identifying strategies to combat sarcopenia and related muscle wasting conditions and neuromuscular disorders. The range of interventions for sarcopenia is extensive and not all can be covered in this first volume. While not covering every possible theme, the selected topics provide important insights into the some of the mechanisms underlying sarcopenia and serve as the basis for subsequent complementary volumes that will eventually provide a definitive resource for understanding age-related muscle wasting and weakness and therapeutic approaches to combat sarcopenia. [ABSTRACT FROM AUTHOR]

Caffeine, theophylline, theobromine, and paraxanthine administered to animals and humans distribute in all body fluids and cross all biological membranes. They do not accumulate in organs or tissues and are extensively metabolized by the liver, with less than 2% of caffeine administered excreted unchanged in human urine. Dose-independent and dose-dependent pharmacokinetics of caffeine and other dimethylxanthines may be observed and explained by saturation of metabolic pathways and impaired elimination due to the immaturity of hepatic enzyme and liver diseases. While gender and menstrual cycle have little effect on their elimination, decreased clearance is seen in women using oral contraceptives and during pregnancy. Obesity, physical exercise, diseases, and particularly smoking and the interactions of drugs affect their elimination owing to either stimulation or inhibition of CYP1A2. Their metabolic pathways exhibit important quantitative and qualitative differences in animal species and man. Chronic ingestion or restriction of caffeine intake in man has a small effect on their disposition, but dietary constituents, including broccoli and herbal tea, as well as alcohol were shown to modify their plasma pharmacokinetics. Using molar ratios of metabolites in plasma and/or urine, phenotyping of various enzyme activities, such as cytochrome monooxygenases, N-acetylation, 8-hydroxylation, and xanthine oxidase, has become a valuable tool to identify polymorphisms and to understand individual variations and potential associations with health risks in epidemiological surveys. [ABSTRACT FROM AUTHOR]

Although endocrine causes of erectile dysfunction (ED) have been well recognized for decades, historically there has been little emphasis on endocrine evaluation or treatment for men with ED. Endocrine abnormalities as a cause or contributing factor for ED are important to recognize since these may be associated with significant additional medical problems, and also because correction of the endocrinopathy often leads to improvement or resolution of ED. This chapter reviews the endocrine causes of ED, and provides a practical approach to the endocrine evaluation and treatment of men with ED. A major emphasis of this chapter is related to testosterone deficiency, which may contribute to ED at various levels, including the brain, peripheral nerves, vasculature, and penis. Testosterone deficiency is becoming increasingly recognized as an important health issue for aging men, with a high prevalence among the age groups at risk for development of ED. Testosterone therapy in these men may resolve ED completely, or may allow for greater responsiveness to more traditional therapies, such as the oral phosphodiesterase 5 inhibitors. A basic hormonal evaluation should be considered for all men presenting with sexual dysfunction. [ABSTRACT FROM AUTHOR]

Anabolic-androgenic steroids include the male hormone, testosterone and its synthetic derivatives. They are Schedule III Controlled Substances with legitimate therapeutic indications, but they are also used non-medically to enhance physical appearance and athletic performance. Patterns of illicit, non-medical use include combining several anabolic-androgenic steroids, including both injection and oral preparations (˵stacking″) as well as both human and veterinary preparations; using 10–100 times therapeutic doses; increasing doses of anabolic-androgenic steroids to a peak and then tapering over time (˵stacking the pyramid″); and alternating periods of use with non-use (˵cycling″). Although used non-medically for their physical effects, anabolic-androgenic steroids have adverse psychiatric effects including hypomania or mania (especially during periods of use), depression and suicidality (especially between periods of use), psychosis, and marked aggression. Adverse medical consequences of illicit use are manifested predominantly in the endocrine, hepatic, and cardiovascular systems, with some deaths reported. In addition to their abuse potential, anabolic-androgenic steroids can lead to withdrawal symptoms and addiction with both similarities to and differences from so-called classical addictive drugs such as opioids. Addiction appears limited to illicit, non-medical users, and has not been documented among those treated therapeutically for legitimate medical purposes. Approximately one-third of 426 non-medical anabolic-androgenic steroid users that were recruited from convenience samples across five different studies met Diagnostic and Statistical Manual of Mental Disorders, 4th edition criteria for anabolic steroid dependence, although the true prevalence is unknown. Both abuse and addiction generally occur in the context of intensive training with weights, combined with strict dietary regimens, in order to optimize bodybuilding effects. Screening questions for anabolic-androgenic steroid use are suggested; and knowledge of the psychiatric, physical, and laboratory findings aids detection. The level of evidence for treating anabolic-androgenic steroid dependence is currently based on case reports and series as well as expert opinion. [ABSTRACT FROM AUTHOR]

The etiologic risk factors and associations contributing to pelvic floor disorders include vaginal parity, ageing, hormonal status, pelvic surgery, collagen diseases, and depression. Many of these relationships, including hormonal status, are poorly understood. In addition, not all pelvic floor disorders are explained by the same risk factors or mechanisms. For example, vaginal parity appears to be the greatest risk factor for developing pelvic organ prolapse, while urinary incontinence has many other risks factors with equal or greater influence, including obesity and ageing. The basic mechanisms of disease and structural failure, both gross and microscopic, which lead to pelvic floor disorders need further investigation. A better understanding of the muscular, collagen, and neuronal components of the pelvic organs and their supports would provide targeted areas for prevention and treatment. [ABSTRACT FROM AUTHOR]

The investigation of new sensing principles and technologies for the detection of molecular binding events has created great expectations on numerous major industrial sectors, such as healthcare, food, water and agriculture. Combining many of these advances with the potential of the immunochemical systems has allowed developing novel biosensors that provide interesting advantages against the traditional strategies for analysis, such as the possibility of multianalysis, development of field analytical methods and fabrication of easy end-user devices. Specifically, many efforts have been lately invested to control residues of pharmaceuticals in food and environmental samples, as an indication of the impact of the human activity in the media. Human and veterinary drugs, such as antibiotics, hormones, analgesics, cytostatics or β-blockers, show a high potential risk of negative effects in the environment and public health. Thus, there is a great need for low-cost and highly efficient tools for quick, reliable, and accurate detection of these contaminating bioactive agents. In particular, the scope of the present chapter is addressed to provide an overview of the potential of novel micro(nano)technology approaches to develop biosensors useful for the analysis of emerging pollutants. [ABSTRACT FROM AUTHOR]

Scarcity of water is a severe environmental constraint to plant productivity. Drought-induced loss in crop yield probably exceeds losses from all other causes, since both the severity and duration of the stress are critical. Here, we have reviewed the effects of drought stress on the growth, phenology, water and nutrient relations, photosynthesis, assimilate partitioning, and respiration in plants. This article also describes the mechanism of drought resistance in plants on a morphological, physiological and molecular basis. Various management strategies have been proposed to cope with drought stress. Drought stress reduces leaf size, stem extension and root proliferation, disturbs plant water relations and reduces water-use efficiency. Plants display a variety of physiological and biochemical responses at cellular and whole-organism levels towards prevailing drought stress, thus making it a complex phenomenon. CO2 assimilation by leaves is reduced mainly by stomatal closure, membrane damage and disturbed activity of various enzymes, especially those of CO2 fixation and adenosine triphosphate synthesis. Enhanced metabolite flux through the photorespiratory pathway increases the oxidative load on the tissues as both processes generate reactive oxygen species. Injury caused by reactive oxygen species to biological macromolecules under drought stress is among the major deterrents to growth. Plants display a range of mechanisms to withstand drought stress. The major mechanisms include curtailed water loss by increased diffusive resistance, enhanced water uptake with prolific and deep root systems and its efficient use, and smaller and succulent leaves to reduce the transpirational loss. Among the nutrients, potassium ions help in osmotic adjustment; silicon increases root endodermal silicification and improves the cell water balance. Low-molecular-weight osmolytes, including glycinebetaine, proline and other amino acids, organic acids, and polyols, are crucial to sustain cellular functions under drought. Plant growth substances such as salicylic acid, auxins, gibberrellins, cytokinin and abscisic acid modulate the plant responses towards drought. Polyamines, citrulline and several enzymes act as antioxidants and reduce the adverse effects of water deficit. At molecular levels several drought-responsive genes and transcription factors have been identified, such as the dehydration-responsive element-binding gene, aquaporin, late embryogenesis abundant proteins and dehydrins. Plant drought tolerance can be managed by adopting strategies such as mass screening and breeding, marker-assisted selection and exogenous application of hormones and osmoprotectants to seed or growing plants, as well as engineering for drought resistance. [ABSTRACT FROM AUTHOR]

The germination and seedling growth of Daucus carota cv. nantes and Capsicum annuum cv. sivri were investigated under stress conditions. D. carrota seeds germinated well in the dark at 20°C (92%) but in the light germination was only 54%. The germination in dark at 20%C was 92%, 84% and 80% at 0.1%, 0.5% and 1% salt (NaCl) solutions, as the concentration increased germination decreased and length of radicle and plumule also got reduced. Germination was 90% at 0.1% NaCl + 10 ppm GA3 and 43% at 2% NaCl +10 ppm GA3. The seeds of C. annuumcv. sivri germinated well at constant temperatures of 15°C (83%), 20°C (100%), and 30°C (88%). The germination was 100% in the seeds placed in distilled water and left at 20°C, but it was delayed or inhibited when salt solutions were applied to these seeds. An application of growth regulators showed that GA3 was stimulatory under saline conditions, However plant survival was low at 2% and 3% salt conditions as compared to 0.5% and 1% salt solutions. C. annuumcv. sivri did not show salt tolerance. When 4 weeks old seedlings of C. annuumwere subjected to fl ooding using tap water, the performance of seedlings was better on unfl ooded soils. The plants survived under short periods of fl ooding but growth was poor, however, under longer periods of fl ooding the mortality increased and plants became sensitive. [ABSTRACT FROM AUTHOR]

Plant hormones can be defi ned as organic substances that are produced in one part of plant and translocated to another parts, where at very low concentration, They stimulate physiological response. Plant hormones are natural products and when they are synthesized chemically they are called plant growth regulators. Plants are usually subjected to environmental factors such as drought or high soil and water salinity. The reduction in plant growth exposed to saline environments could be due to either the effects of specifi c ions on metabolism, or adverse water relations. Different strategies are being employed to maximize plant growth under saline conditions. One of them is to produce salt tolerant genotypes of different crops. Attempts to improve tolerance to salinity through conventional plant breeding methods are time consuming and laborious, and rely on existing genetic variability. In addition, many other attempts have been made to overcome this disorder, including proper management and exogenous application of plant growth regulators. In this context, the levels of gibberellic acid (GA), abscisic acid (ABA), indoleacetic acid (IAA), cytokinins (CK), jasmonates (JA) and triazoles under salt stress are being discussed in this review. [ABSTRACT FROM AUTHOR]

The article presents information on hormone disorders and definitions of words related to the disorders as used in the book "Nolo's Guide to Social Security Disability." According to the U.S. Social Security Administration (SSA), if the hormone disorder affects the function of other organ systems, evaluation should be done under the appropriate listing. It is stated that for listings, hormone abnormalities must have persisted or be expected to persist, despite therapy, for at least one year.

The incorporation of glycosides into peptide neurotransmitters imparts drug-like character to the neurotransmitter ˵message″ via ˵membrane hopping″. The importance of the glycopeptide–membrane interaction is emphasized, and the biousian theory is briefly explained. Application of this approach to enkephalins, the endogenous opioid peptides, leads to potent analgesic compounds capable of systemic delivery. The clinical applications of these compounds are advocated by the author. [ABSTRACT FROM AUTHOR]

‘Unting is all that's worth living for – all time is lost wot is not spent in ‘unting – it is like the hair we breathe – if we have it not we die – it's the sport of kings. The most vital possessions of the plant are the chloroplasts in the cells of its leaves. Through these, the organism can convert, for its own purposes, a fraction of the solar energy that falls upon it. Sunlight is remarkably uniform in its intensity, and a plant has little to gain by moving about. It can thus afford a relatively stationary existence, the only motion being that required to reach regions beyond the shade of its immediate environment and its competitors. Because they have no chloroplast-bearing cells, animals have paid the penalty of having to develop several specialized functions in order to satisfy their energy requirements. They must have a means of locomotion and feeding, and some form of coordination of these faculties, however primitive, is needed. And as insurance against the unsuccessful forage, they should be able to store digested energy. Moreover, unless an animal is so small that the normal process of diffusion is adequate, it must have a circulatory system to distribute dissolved gases and chemical compounds to its various parts. [ABSTRACT FROM AUTHOR]

The evolution of the horse was certainly a most tortuous process. None of your seven day nonsense! Seven days' labour wouldn't evolve one primitive earthworm. There are interesting parallels between the structuring of multicellular organisms and societies. We see the same elements of aggregation, communication, commitment and differentiation, and although some regret the decline of the protean ideal, specialization was a minor penalty to pay for the development of modern society. After all, more people have flown in aeroplanes than ever held a pilot's licence, and more have enjoyed the benefits of surgery than ever wielded a scalpel. And how many of us would be meat eaters if we had to do our own butchering? There are even similarities in the way societies and multicellular organisms subordinate the individual to the point of dispensability. A nation survives the death of any citizen, however prominent, and a mature organism hardly seems to notice replacement of its individual cells. Moreover, it now appears that the collective structure has a vested interest in the mortality of its members; the multicellular organism follows a policy of programmed death, and a steady turnover increases the chance of a favourable mutation. This too might have its social counterpart; what happens to individual members after they have procreated is of minor importance, and old worn-out citizens are replaced by fresh young individuals. [ABSTRACT FROM AUTHOR]

There is no excellent beauty that hath not some strangeness in the proportion. Most substances can exist in three different states: solid, liquid and gas. The temperature, pressure and density collectively determine which form is adopted, and changes in the imposed conditions can produce the melting and boiling phase transitions. The solid state is usually crystalline, but some solids have the meta-stable glass structure. Differences between the three fundamental states are often depicted by simple diagrams in which atoms are represented by circles. For a gas, the circles are drawn randomly, with the distance between neighbouring circles somewhat larger than the circle diameter. The condensed states, crystal and liquid, are illustrated by arrangements in which the distances between the centres of neighbouring circles are comparable to the diameters, the difference between these forms lying mainly in the regular arrangement of the former and the relative randomness of the latter. We can go a long way with such models because real atoms are indeed roughly spherical. This is particularly true for noble gases such as argon and neon, because of their closed electron shells, but it is a reasonable approximation for all atoms. The question arises as to what happens if the atoms are replaced by molecules elongated in one direction. The answer is to be found in that peculiar intermediate state of matter: the liquid crystal. A description of arrangements in terms of positions of centres of gravity is inadequate for elongated molecules. [ABSTRACT FROM AUTHOR]

Claims abound regarding the presumed motivations, temperaments, and cognitive patterns of terrorists and of those who support terrorism. Very few of these claims have been tested empirically. We attempted to test several previously proposed hypotheses using more rigorous methods. First, is sympathy for terrorism associated with emotional distress, and especially with conflict-trauma-related distress? Second, is sympathy for terrorism associated with perceived oppression? Third, does sympathy for terrorism correlate with the general trait of aggressivity? Fourth, recognizing the robust evidence that both aggression and chronic stress are associated with neuroendocrine changes, do individuals with different neuroendocrine status exhibit different degrees of sympathy for terrorism? Preliminary results will be discussed. [ABSTRACT FROM AUTHOR]

A monograph for the pharmaceutical substance "PREDNISOLONI ET NATRII SUCCINATIS PULVIS AD INJECTIONEM/PREDNISOLONE SODIUM SUCCINATE POWDER FOR INJECTIONS" from the fourth edition of "The International Pharmacopoeia" is presented. Prednisolone sodium succinate powder is categorized as an adrenal hormone and described as an odourless, white powder or friable lumps. The container of this substance should state the nature of the buffering agent. Procedures for performing an identity test and assay of the substance are described.

The measurement of the expression of hormonally regulated genes in breast cancer may provide an indication of its hormone responsiveness. In addition, these genes may provide novel therapeutic targets. This chapter reviews the hormonally responsive genes that have been identified in breast cancer cell lines and tumors, using differential hybridization, differential display, serial analysis of gene expression, and array technology. The biological relevance of the genes identified is discussed. [ABSTRACT FROM AUTHOR]

An encyclopedia entry for the term "steroid hormones" is presented. Steroid hormones are lipophilic compounds derived from cholesterol metabolism, which typically mediate their biological activity by binding to a specific intracellular cytosolic receptor. The types of streroid hormones and their characteristics are discussed, including glucocorticoids, androgens, and estrogens.

An encyclopedia entry for the term transmembrane signalling is presented. Cellular functions are controlled by extracellular signals such as hormones, neurotransmitters and odorants but only a few of these signal molecules permeate the plasma membrane to interact with their intracellular receptors. Transmembrane signalling processes involve the recognition and reversible binding of an extracellular signal.

The article presents an encyclopedia entry for JAK-STAT pathway. JAK-STAT stands for Janus kinase-signal transducer and activator of transcription signaling pathway. It is activated in response to a large number of cytokines, hormones and growth factors. The basic characteristics as well as the physiological functions of JAK-STAT are also presented.

An encyclopedia entry for "insulin receptor" is presented. The insulin receptor is a transmembrane receptor tyrosine kinase situated in the plasma membrane of insulin-sensitive cells. The insulin receptor is a heterotetrameric protein consisting of two extracellular subunits and two membrane-spanning subunits.

Introduction The majority of studies on antisocial behaviour have focused on causes and risk factors. Thanks particularly to prospective longitudinal studies, we now have a pretty good understanding of the characteristics of youngsters who are at risk of becoming serious offenders (e.g., Loeber and Farrington, 1998). Developmental models such as Moffitt's (1993a) taxonomy of adolescence-limited and life course-persistent antisociality, the distinction between early and late starters (Patterson et al., 1991), or the three pathways model of overt, covert, and authority conflict from Loeber and Hay (1994) offer explanations for the onset, persistence, and aggravation of various forms of antisocial behaviour. Although researchers do not agree about the number and structure of different pathways to serious delinquency (Loeber and Stouthamer-Loeber, 1998; Nagin and Tremblay, 1999), children who show both overt and covert antisocial behaviour and early official delinquency seem to be particularly at risk for chronic offending (Farrington and Loeber, 2001; Patterson et al., 1998). However, most research on persistent antisociality focuses on risks, deficits, and negative behavioural trends. Much less attention is paid to processes of abstaining or desistance (Farrington, 1994; Loeber and Stouthamer-Loeber, 1998; Nagin and Tremblay, 1999). Such processes are no rarity: for example, in the Kauai Study (Werner and Smith, 1992; see below), one out of three high-risk children grew into a competent, confident, and caring young adult. Robins (1978) and Moffitt et al. (1996) have shown that about one half of children with conduct disorders or extreme antisociality did not go on to serious criminal outcomes. [ABSTRACT FROM AUTHOR]

The article presents Chapter VIII of the book "Compassion: A New Philosophy of the Other," by Werner J. Krieglstein. It explores the perspective difference between men and women, in which it cites a story on the stages of married life from a man's perspective. It says that the 1960s psychological experiment proved most gender results from nurture. It mentions that behavioral endocrinologist Marc Breedlove studied how hormones can help to build sexually different nervous systems.

A definition of the term "MAP kinase" is presented. It refers to mitogen activated protein (MAP) kinase. MAP kinases are a subfamily of protein kinases, enzymes which carry out the chemical transfer of phosphate from ATP to protein acceptors. They are components of signal transduction pathways that allow extracellular signals such as hormones and growth factors to modulate cellular responses as varied as growth, differentiation, motility and apoptosis.

Cardiovascular disease is the leading cause of mortality both in type 1 (insulin-dependent) and type 2 (non-insulin-dependent) patients. Reduction of this excessive cardiovascular mortality rate represents the main aim of diabetes care. However, some aspects of cardiovascular disease may differ between diabetic and non-diabetic patients. In this article we provide an overview of treatment strategies in patients with diabetic nephropathy and coronary heart disease. It has been estimated that coronary artery disease is present in every second of unselected diabetic patients. Several studies from all over the world show that patients with insulin-dependent-diabetes (type 1) exhibit a dramatic excess in mortality compared to non-diabetic subjects. While acute, metabolic complications dominate the causes of death in patients with short diabetes duration, long term excess mortality is restricted almost exclusively to those 30 to 40% of type 1 diabetic patients who develop diabetic nephropathy during the course of the disease. Nephropathy is, however, not the direct cause for increased mortality rates in these patients. Although the risk of progression to renal failure is high in type 1 diabetes with macroalbuminuria, in Europe only few type 1 and type 2 diabetic patients will die a renal death, because renal replacement therapy is, in general, available to all patients with end-stage renal failure. Rather, cardiovascular events represent the main cause of death in patients with diabetic nephropathy. Interestingly, the distribution of the causes of death is very similar in type 1 diabetic patients with nephropathy and in type 2 diabetes. The cumulative incidence of cardiovascular disease by the age of 40 years is about 43% in type 1 diabetic patients with nephropathy and 7% in those without. When compared to patients with normal renal function the presence of nephropathy increased the risk of coronary heart disease and stroke 10-fold. A reduction of this severely increased mortality risk is possible and urgently needed in nephropathic diabetic patients. [ABSTRACT FROM PUBLISHER]

The article presents a study which identifies the contribution of cortisol as the principal glucocorticoid hormone, to homeostatic regulation of basal metabolism and salt and water balance, and modulating the response to stress. It was demonstrated that altered peripheral metabolism of cortisol in obesity which may have important effects on tissue response to glucocorticoids.