Valparin

By J. Karmok. Concordia College, Saint Paul Minnesota.

New muta- functions; they code for the production of proteins purchase valparin 250mg visa, and tions are less common in other forms of muscular dys- they are the material of inheritance. DMD, BMD, CMD, and most forms of LGMD, are due Because both parents contribute genetic material to to alterations in the genes for a complex of muscle pro- their offspring, each child carries two copies of almost teins. For some conditions to thin sheath that surrounds each muscle cell) to unite a occur, both copies must be altered. Such conditions are fibrous network on the interior of the cell with a fibrous called autosomal recessive conditions. Theory holds that by linking LGMD and DD exhibit this pattern of inheritance, as these two networks, the complex acts as a “shock does CMD. A person with only one altered copy, called a absorber,” redistributing and evening out the forces gen- carrier, will not have the condition, but may pass the erated by contraction of the muscle, thereby preventing altered gene on to his children. Alterations in the pro- children, the chances of having a child with the condition teins of the complex lead to deterioration of the muscle is one in four for each pregnancy. Other conditions occur when only one altered gene Symptoms of these conditions set in as the muscle grad- copy is present. Either the fluid itself or cells from affects young boys and causes progressive muscle the fluid can be used for a variety of tests to obtain weakness, usually beginning in the legs. Both Duchenne muscular dystrophy Autosomal dominant—A pattern of genetic inheri- and Becker muscular dystrophy are caused by flaws tance where only one abnormal gene is needed to in the gene that instructs the body how to make this display the trait or disease. Autosomal recessive—A pattern of genetic inheri- Facioscapulohumeral muscular dystrophy (FSH)— tance where two abnormal genes are needed to dis- This form of muscular dystrophy, also known as play the trait or disease. Landouzy-Dejerine condition, begins in late child- Becker muscular dystrophy (BMD)—A type of mus- hood to early adulthood and affects both men and cular dystrophy that affects older boys and men, women, causing weakness in the muscles of the and usually follows a milder course than Duchenne face, shoulders, and upper arms.

The practice of marrying or having children examination of the family history a counselor may be with relatives is infrequent in the United States generic valparin 250mg with visa, but is able to discuss the probability of future occurrence of more common in some countries. In recessive inheritance, each parent of a child affected with a disease carries a single gene In taking a family history, a genetic counselor asks for the disease. People who have a com- ethnic groups that have a higher chance of being carriers mon ancestor are more likely than unrelated people to of some genetic diseases. For instance, the chance that an be carriers of genes for the same recessively inherited African American is a carrier of a gene for sickle cell dis- genes. People of Jewish ancestry are more likely to ground, blood tests can be offered to couples to get be carriers of several conditions including more information about the chance for these conditions, and. Genetic coun- selors discuss inheritance patterns of these diseases, car- rier risks, and genetic screening or testing options. During prenatal genetic counseling, the counselor will ask about pregnancy history. If the patient has taken a medication or has had a harmful exposure (like radia- tion), the genetic counselor can discuss the possibility of Another question a genetic counselor asks in taking harmful affects. Ultrasound is often a useful tool to look a family history is if the couple is related to one another for some affects of exposures. Abnormal formation of body systems and parts, for instance the giantisim of feet, often assists with diagnosis of specific inherited disorders. Alzheimer dis- ease CANCER SUSCEPTIBILITY TESTING oncogene Tay-Sachs disease multiple endocrine neo- Huntington disease plasia ovarian cancer 478 GALE ENCYCLOPEDIA OF GENETIC DISORDERS Archives of Neurology American Family Physician Laboratory Medicine Laboratory Medicine Laboratory Medicine Science Blazing a Genetic Trail. Disorder Alternative names Inheritance Abnormal protein Abnormal gene Gene location GM1-gangliosidosis Type II coloboma Prognosis Resources BOOKS scoliosis PERIODICALS ORGANIZATIONS Diagnosis Treatment and management WEBSITES GALE ENCYCLOPEDIA OF GENETIC DISORDERS 493 (Custom Medical Stock Photo, Inc. Careful monitoring for etretinate-related side University of Washington Dermatology Department, Box effects in children, such as bone toxicity, is recom- 356524, 1959 N. Knutel, MS, CGC because of prematurity or constriction by the thick scale, dehydration, malnutrition, or severe skin infection. Longer-term survivors have been reported but these chil- dren have required intensive, on-going medical care. Etretinate has been an effective form of treatment for some infants but its use has only been for short periods of time since the affected infants have still died.

Sebaceous—Related to the glands of the skin that hMLH1 and hMSH2—Genes known to control mis- produce an oily substance buy valparin 250mg without a prescription. Splenic flexure—The area of the large intestine at Keratoacanthoma—A firm nodule on the skin typi- which the transverse colon meets the descending cally found in areas of sun exposure. When these genes are not func- conditions are the same including increased risk of col- tioning properly, there is a higher chance of cancer due to orectal cancer (cancer of the colon and rectum) and can- the alterations that accumulate in the genetic material. Both conditions are hereditary cancer Heritable mutations in at least five mismatch repair genes predisposition syndromes meaning that the risk of cancer have been linked to HNPCC although the majority, over has been linked to an inherited tendency for the disease. Mutations in A unique feature of Muir-Torre syndrome is the skin hMLH1 and hMSH2 also have been reported in Muir- tumors. The most common skin tumors associated with Torre syndrome, although most have been hMSH2 muta- Muir-Torre syndrome are benign (non-cancerous) or tions. The location of the hMLH1 gene is on malignant (cancerous) tumors of the oil-secreting (seba- chromosome 3 at 3p21. Genetic testing for hMLH1 skin finding is the presence of growths called keratoa- and hMSH2 is available but the detection rate for mis- canthomas. Therefore, diagnosis of Muir-Torre syndrome is not based on genetic testing alone but also on the presence of Genetic profile the typical features of the disease. HNPCC and Muir-Torre syndrome are allelic mean- Muir-Torre syndrome is inherited in an autosomal ing that these disorders are due to changes in the same dominant fashion. Genes, the units of instruction for the body, can Muir-Torre syndrome and only one gene of the paired have changes or mutations that develop over time. Children 758 GALE ENCYCLOPEDIA OF GENETIC DISORDERS TABLE 1 TABLE 2 Screening recommendations for patients with Additional screening recommendations for females Muir-Torrie syndrome with Muir-Torrie syndrome Test/Procedure Age Frequency Test/Procedure Age Frequency Physical exam 20 Every 3 years Breast exam 20–40 Every 3 years 40 Annually 40 Annually Digital rectal exam Any Annually Pelvic exam 18 or sexually active Annually Gualac of stool for occult blood Any Annually Pap smear 18 or sexually active Annually Lab work-up Any Mammogram 40–49 Every 1–2 years Carcinoembryonic antigen 50 Annually Complete blood cell count with Endometrial biopsy Menopause Every 3–5 years after onset differential and platelet count Erythrocyte sedimentation rate Serum chemistries (SMA-20) Urinalysis Any Annually Chest roentgenogram Any Every 3–5 years drome with multiple types of internal cancers have been Colonoscopy Any Every 5 years reported. The most common internal organ cancer is col- If positive for polyps Every 3 years orectal cancer. Unlike colon cancers in the general popu- lation, the tumors due to Muir-Torre syndrome are more frequently seen around or closer to the right side of an of individuals with Muir-Torre syndrome have a one in area of the colon known as the splenic flexure. At least 250 cases of Muir-Torre syndrome, specifi- Symptoms of colorectal cancer or polyps may cally, have been reported.

This gas is produced by the the lung by diseases cheap 250 mg valparin with amex, such as silicosis and berylliosis, breakdown of uranium, and does not present any prob- which are caused by inhalation of certain minerals, tu- lem outdoors. In the basements of some houses that are berculosis, and certain types of pneumonia. This scar- built over soil containing natural uranium deposits, how- ring may increase the risk of developing lung cancer. Other forms cancer is not known, people with a family history of lung of environmental pollution (e. In 2003, researchers were continuing work GALE ENCYCLOPEDIA OF ALTERNATIVE MEDICINE 2 1239 aimed at learning why some smokers were more suscepti- If the doctor has reason to suspect lung cancer— ble to lung cancer than others. They discovered a type of particularly if the patient has a history of heavy smoking DNA repair characteristic apparent in smokers who were or occupational exposure to substances that are known to less likely to get lung cancer. Continued work along these irritate the lungs—he or she may order a chest x ray to lines could lead to possible screening for DNA that see if there are any masses in the lungs. Symptoms A technology called spiral CT, which rotates allowing Lung cancers tend to spread very early, and only for images of the chest from all angles, can detect lung 15% are detected in their early stages. A report in early detection, however, can be improved by seeking 2002 said spiral CT technology could help doctors screen medical care at once if any of the following symptoms the population for lung cancer, but the idea of screening appear: remains controversial. However, re- searchers were recommending further trials to determine • swelling of the neck and face the effectiveness of the screening tool for future use. By combining positron emission to- • fatigue and loss of appetite mography (PET) with CT, or PET-CT, physicians could • bloody or brown-colored spit or phlegm (sputum) more accurately see the details of the tumorís progres- sion (or regression after treatment) and to diagnose a • unexplained fever lung tumor better. It is vital, however, to con- of the cells that are either coughed up from the lungs, or sult a doctor to rule out the possibility that they are the are collected through a special instrument called a bron- first symptoms of lung cancer. Sputum analyses can diagnose at least 30% of If the lung cancer has spread to other organs, the pa- lung cancers, some of which do not show up even on tient may have other symptoms, such as headaches, bone chest x rays.

We provide evidence from peripheral and SI recordings that the high frequencies discount 750 mg valparin, in the hundreds of Hertz (Hz), transmitted by vibrissae at their funda- mental resonance frequency can drive high fidelity neural activity. These findings suggest that a volley principle may exist in the transmission of high resolution temporal signals from the periphery. Specifically, the sensitivity of this system to high velocity vibrissa motion, and the high degree of direction tuning observed in many trigeminal neurons, suggest that an inherent frequency doubling may occur through the convergence of signals from direction-tuned peripheral neurons. In the final section of this chapter, we summarize the main findings and give a brief discussion of how the principles described here may relate to human tactile perception. THE BEHAVIORAL RELEVANCE OF HIGH FREQUENCY SOMATOSENSORY PERCEPTION Frequency information approximately tens of Hz to over a kHz is essential to accurate sensory processing in the auditory, somatosensory, and visual domains. The soma- tosensory system employs frequency-specific information in a variety of perceptual contexts. Vibratory stimuli transmitted through solid media provide an important sensory input to a variety of mammalian species. For example, blind moles are known to seek out conspecifics and termite colonies using primarily vibratory cues transmitted through the ground. High frequency, temporally varying information also directly benefits human tactile perception. Surface perception in humans may employ temporally varying signals related to vibration perception. While spatially intensive cues dominate the judgment of roughness for surfaces with a periodicity in the range of ~1–3 mm,4,5 temporal frequency information likely contributes to the judgment of spatial © 2005 by Taylor & Francis Group. For example, robust tactile apparent motion illusions can be evoked when specific frequencies of stimulation, typically ≥50 Hz, are applied either sequentially across a series of three or more contact points or in bursts applied to >2 contact points.