By Y. Gembak. Westwood College Georgia.
Therefore hytrin 1 mg mastercard pulse pressure pda, Pergonal) are isolated from urine of postmenopausal use of ACTH (Acthar) is restricted to diagnosis; a women and contain both FSH and LH purchase 1mg hytrin visa arteria coronaria. Puriï¬ed prepa- shorter 24âamino acid analogue (Cosyntropin) is also rations of FSH from the same source are also available used. During early sult in peak plasma levels of glucocorticoids within 30 pregnancy, trophoblasts of the placenta produce hCG to 60 minutes if the adrenal gland is functional. LH and hCG bind to the same go- Prolonged administration of ACTH in a repository nadal receptors, but hCG is more stable and can be iso- form, however, may be necessary to stimulate steroid lated from urine of pregnant women, so hGH prepara- production, because ACTH has long-term trophic ef- tions (Pregnyl, Profasi) are used to mimic the burst of fects on adrenal cells in addition to the rapid stimula- LH secretion before ovulation. If the cause of steroid deï¬- tions of FSH are also available (follitropin, Gonal F, ciency is at the level of the pituitary gland, ACTH Follistim). In addition, Thyrotropin-Releasing Hormone dopamine released from the hypothalamus inhibits pro- lactin production. TRH (Relefact TRH) is used for Somatostatin tests to distinguish primary from secondary hypothy- roidism (see Chapter 65). Somatostatin (or somatotropin releaseâinhibiting fac- tor [SRIF]) occurs primarily as a 14âamino acid pep- Gonadotropin-Releasing Hormone tide, although a 28âamino acid form also exists. As with the other hypothalamic peptides, it is formed by prote- GnRH (gonadorelin, luteinizing hormoneâreleasing olytic cleavage of a larger precursor. Somatostatin, orig- hormone) is a decapeptide that stimulates production inally isolated from the hypothalamus, is also in many of LH and FSH. It is released in bursts from the hypo- other locations, including the cerebral cortex, brain- thalamus at regular intervals, about every 2 hours, al- stem, spinal cord, gut, urinary system, and skin. The Somatostatin has a very brief half-life in serum and pattern of LH and FSH in cycling women, including the is not useful clinically. An 8âamino acid analogue with 2 large burst of LH release before ovulation, can be stim- D-amino acids substituted for the naturally occurring ulated by regular administration of GnRH pulses. The L-amino acids is more stable, and monthly injections of large burst of LH from the pituitary gland appears to be a depot form of this analogue (octreotide, Sandostatin induced by feedback through estradiol and other prod- LAR) have several uses. Long-acting octreotide is used ucts of the gonads that change the response of the pitu- to treat acromegaly, as described earlier. It is also used itary gland to the GnRH pulses rather than by large to counteract unpleasant effects caused by overproduc- changes in the amounts of GnRH secreted. The stimu- tion of secreted bioactive substances produced by neu- latory response to GnRH depends on pulsatile adminis- roendocrine tumors, including hyperinsulinemia from tration and the timing of the pulses. Continual adminis- insulinomas and secretions from carcinoid tumors that tration of GnRH does not have the same effects as cause severe diarrhea. Octreotide may also control se- pulsatile administration; although production of LH vere diarrhea associated with AIDS that has not re- and FSH is stimulated initially, it is suppressed within a sponded to other treatments. Part of this desensitization to GnRH is caused Transient side effects, gastrointestinal discomfort by a decrease in the number of pituitary receptors for and decreased glucose tolerance, usually last only a few GnRH; additional postreceptor mechanisms are also weeks after initiation of therapy. Inhibition of secretion of Growth hormone Thyroid-stimulating hormone Gonadotropin Stimulation Prolactin ACTH When stimulation of gonadotropin production is Insulin needed, the pituitary gland is usually capable of re- Glucagon sponding to appropriately administered GnRH, even in Pancreatic polypeptide cases of hypogonadotropic hypogonadism, when LH Gastrin and FSH levels are always low. Therefore, GnRH ther- Cholecystokinin Secretin apy can be substituted for gonadotropin therapy by ad- Vasoactive intestinal peptide ministering GnRH (Lutrepulse) pulses intravenously Exocrine pancreas secretion via an indwelling pump. GnRH itself is used, since the Inhibition of bile ï¬ow short half-life is important to prevent accumulation be- Inhibition of mesenteric blood ï¬ow tween pulses. The advantage of this procedure com- Decreased gastrointestinal motility pared with intramuscular injections of gonadotropins 682 VII DRUGS AFFECTING THE ENDOCRINE SYSTEM for treating infertility is that normal levels of LH and and include hot ï¬ashes (sudden intense surface temper- FSH should be maintained because of feedback from ature elevation and sweating), dry skin and vagina; the gonads. The addition perstimulation and multiple births, since the procedure of estrogen and progesterone can reduce the adverse ef- should not result in inappropriately high levels of go- fects while maintaining gonadotropin suppression. However, there is a continuing need to address the re- cent cancer risk cautions issued for short-term versus Gonadotropin Suppression long-term use of estrogenâprogesterone combinations as hormonal replacement therapy. Because these ago- nists are long acting, they suppress gonadotropin pro- Corticotropin-Releasing Hormone duction after an initial stimulation. In some uses, the ini- Corticotropin-releasing hormone consists of 41 amino tial stimulation of gonadotropin is undesirable; a newer acids; it stimulates ACTH release. These com- pounds are formulated so they can be injected monthly HORMONES OF THE POSTERIOR or even less frequently. PITUITARY GLAND In men, androgens stimulate growth of prostatic cancer; therefore, a reduction in androgen actions is Antidiuretic hormone (ADH) and oxytocin are synthe- used for palliative treatment (see Chapter 63). Estrogen sized in the supraoptic and paraventricular nuclei in the use increases mortality in men primarily as a result of brain and are transported in secretory granules through cardiovascular complications, and castration is not pop- axons to the posterior lobe. When long- larger precursor, which is processed into the hormone acting agonists are given, signs and symptoms of prosta- plus a protein that binds the hormone, called neuro- tic cancer may increase shortly after initiation of ther- physin.
Usually benign generic 5mg hytrin with amex heart attack, warts have been associated with cancer 1mg hytrin with visa heart attack 70 blockage, especially in the case of genital warts and cancer Acne (AK-ne) is a disease of the sebaceous (oil) glands of the cervix (neck of the uterus). The common type, called acne vulgaris (vul-GA-ris), is found most often in Fungal Infections Fungi are non-green, plantlike mi- people between the ages of 14 and 25 years. Acne is usually most severe at known as tinea or ringworm, may appear on the face, body, adolescence, when certain endocrine glands that control scalp, hands, or feet (Fig. Fungal Impetigo Impetigo (im-peh-TI-go) is an acute conta- infections of the nails commonly result from wearing false gious disease of staphylococcal or streptococcal origin nails or acrylic nails, as fungal growth is promoted by the that may be serious enough to cause death in newborn in- moisture that accumulates under the artificial nails. Viral Infections One virus that involves the skin is herpes (HER-peze) simplex virus, which causes the for- mation of watery vesicles (cold sores, fever blisters) on the skin and mucous membranes. SLE is more plications of the drug minoxidil (used as an oral medica- prevalent in women than in men and has a higher inci- tion to control blood pressure) have produced growth of dence among Asians and blacks than in other popula- hair in this type of baldness. Internal organs become involved in a diffuse form of scleroderma called progressive systemic sclerosis Allergy, also known as hypersensitivity, is an unfavorable (PSS). Often the skin is in- Pressure ulcers are skin lesions that appear where the volved in such responses, showing inflammation, rashes, body rests on skin that covers bony projections, such as vesicles, or other forms of eruptions, usually accompa- the spine, heel, elbow, or hip. Poor Urticaria (ur-tih-KA-re-ah), or hives, is an allergic re- general health, malnutrition, age, obesity, and infection action characterized by the temporary appearance of ele- contribute to the development of pressure ulcers. If ignored, they may penetrate the skin and underlying muscle, ex- Autoimmune Disorders An autoimmune disease re- tending even to bone and requiring months to heal. The Pads or mattresses to relieve pressure, regular cleans- following diseases that involve the skin are believed to be ing and drying of the skin, frequent change in position, caused, at least in part, by autoimmune reactions. Pre- Pemphigus (PEM-fi-gus) is characterized by the for- vention of pressure ulcer by these methods is far easier mation of blisters, or bullae (BUL-e) in the skin and mu- than treatment of an established ulcer. Both of these terms refer to lying down, al- leaves deeper areas of the skin unprotected from infection though pressure ulcers may appear in anyone with lim- and fluid loss, much as in cases of burns. Much like the frame of a build- produce movement ing, the skeleton must be strong enough to support and â To serve as a storehouse for calcium salts, which may protect all the body structures. The in- Bones have a number of functions, several of which are dividual bones in these two divisions will be described in not evident in looking at the skeleton: detail later in this chapter. They may be flat (ribs, cra- â To protect such delicate structures as the brain and the nium), short (carpals of wrist, tarsals of ankle), or irregu- spinal cord lar (vertebrae, facial bones). Humerus Cartilage Sternum Epiphyseal line Costal Ribs (growth line) cartilage Proximal Radius epiphysis Spongy (cancellous) Vertebral column bone (containing Carpals red marrow) Ilium (of pelvis) Ulna Endosteum Pelvis Compact bone Meta- Sacrum carpals Medullary (marrow) cavity Phalanges Artery and vein Femur Diaphysis Yellow marrow Patella Periosteum Calcaneus Fibula Tibia Tarsals Distal epiphysis Metatarsals Phalanges Figure 7-1 The skeleton. Even though the across the bone, from one side of the shaft to the other, spaces between the cells of bone tissue are permeated are many perforating (Volkmann) canals, which also with stony deposits of calcium salts, the bone cells them- house blood vessels and nerves. Bones are organs, with their The second type of bone tissue, called spongy, or can- own system of blood vessels, lymphatic vessels, and cellous, bone, has more spaces than compact bone. The cells in this type of bone are located in rings of bone tissue around a central haversian (ha-VER-shan) Checkpoint 7-1 A long bone has a long, narrow shaft and two canal containing nerves and blood vessels. Each ringlike unit with its cen- Checkpoint 7-2 What are the two types of osseous (bone) tis- tral canal makes up a haversian system, also known as an sue and where is each type found? Forming a channel Medullary cavity Osteon (haversian Rings of system) bone tissue Haversian canal Spaces Osteon (lacunae) for bone cells B Haversian (central) canal Osteocytes (in lacunae) Periosteum Blood vessels Perforating (Volkmann) canals A Figure 7-3 Compact bone tissue. These cells, now known as osteocytes (OS-te- o-sites), are still living and continue to maintain the ex- isting bone matrix, but they do not produce new bone tis- sue. The inner Formation of a Long Bone In a long bone, the layer of this membrane contains cells (osteoblasts) that transformation of cartilage into bone begins at the center are essential in bone formation, not only during growth of the shaft during fetal development. Blood vessels and lym- birth, secondary bone-forming centers, or epiphyseal phatic vessels in the periosteum play an important role in (ep-ih-FIZ-e-al) plates, develop across the ends of the the nourishment of bone tissue. The long bones continue to grow in length at these riosteum make their presence known when one suffers a centers by calcification of new cartilage through child- fracture, or when one receives a blow, such as on the hood and into the late teens. Each epiphy- DOS-te-um), lines the marrow cavity of a bone; it too seal plate hardens and can be seen in x-ray films as a thin contains cells that aid in the growth and repair of bone line, the epiphyseal line, across the end of the bone. Bone Growth and Repair As a bone grows in length, the shaft is remodeled so During early development, the embryonic skeleton is at that it grows wider as the central marrow cavity increases first composed almost entirely of cartilage.
The growth discount 2 mg hytrin mastercard arteria y vena poplitea, availability hytrin 1 mg heart attack yahoo answers, and acces- sibility of the Internet opened the door for development of a new model for sharing medical knowledge and decision support systems across networks. Internet-based decision support systems with focus on a particular medical domain will be prevalent in the future. For example, several medical guideline modeling languages are using a common interface for knowledge acquisition purposes. ProtÃ©gÃ© is the most commonly used tool to acquire the knowledge and then formulate the output in various modeling languages. This converg- ing trend will begin to happen at the knowledge representation and knowledge execution modules as well. This will give raise to a true acceptance of a common knowledge sharing technique. The next key area of medical decision support systems is the unique characteristics of its users. Most users get intimidated by the complexities and challenges posed by the user interface. While medical decision making is not a simple process, the decision support systems should help reducing the complexity and not increasing them. Past studies indicate that the complexity of customizing the knowledge or a simple rule forces the physicians to refrain form using the system. Training clinicians in usage of complex decision support process is a worthy investment. The benefits of the usage of medical decision support systems outweigh the costs incurred in development, implementation, and maintenance of such products. Chapter Summary Medical decision support systems, when used along with the clinical information systems at the point of care can improve the quality of care provided. Despite evidence of the benefits of decision support, and despite endorsement by a national patient safety panel (Kohn, Corrigan & Donaldson, 2000), computerized clinical decision support has not achieved wide diffusion. A recent survey found that such systems were used in less than five percent of all healthcare facilities (Wong, Legnini, Whitmore, & Taylor, 2000). When the user interface, availability, and accessibility issues of the medical decision support systems are properly addressed, the usage of the systems will grow multi fold! When such medical decision support systems are blended into the day-to-day practice workflow, then these systems are destined to succeed! Copying or distributing in print or electronic forms without written permission of Idea Group Inc. Medical Decision Support Systems and Knowledge Sharing Standards 215 References Beatty, P. User attitudes to computer-based decision support in anesthesia and critical care: A preliminary survey. Rule-based expert systems: The MYCIN experiments of the Stanford heuristic programming project. Management science: Modeling, analysis and interpretation, Cincinnati, OH: South-Western. NeoGanesh: A working system for the automated control of assisted ventilation in ICUs. Effect of clinical guidelines on a medical practice: A systematic review of rigourous evaluations. Effects of computer-based clinical decision support systems on physician performance and patient outcomes: a systematic review. Effects of computer based clinical decision support systems on clinician performance and patient outcome. Computerized decision support based on a clinical practice guideline improves compliance with care standards. Copying or distributing in print or electronic forms without written permission of Idea Group Inc. Open clinical knowledge management for medical care - Guideline modelling methods and technologies.