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By G. Gnar. American Academy of Art. 2018.

At one point order 50mg viagra super active with mastercard, this hose Children with OTC deficiency are also given arginine 50mg viagra super active with visa, an runs through a tank made up of liquid that contains all GALE ENCYCLOPEDIA OF GENETIC DISORDERS 849 the components of blood generic viagra super active 25mg without prescription, but no ammonia (this liquid is ORGANIZATIONS like the water in the water and cola example) purchase viagra super active 25 mg amex. The future The future treatment of OTC deficiency probably will come from experiments in gene therapy order viagra super active 50mg without prescription. OTC defi- IOsler-Weber-Rendu ciency is a disorder particularly amenable to gene therapy syndrome because only one gene is affected and only one organ, the liver, would need the new gene. However, as of 2001, Definition gene therapy has not been successfully demonstrated in Osler-Weber-Rendu syndrome (OWR), or hereditary human beings. Many technical problems must still be hemorrhagic telangiectasia (HHT), is a blood vessel dis- solved in order to successfully treat OTC deficiency and order, typically involving recurrent nosebleeds and other disorders like it with gene therapy. Arteriovenous malformations (AVMs) are Only 50% of the most severely affected patients live abnormal, direct connections between the arteries and beyond the time they first attend school. The story of OWR began years ago with a sequence of events between three prominent physicians, Osler, For individuals not identified at birth or soon after, Weber, and Rendu. Osler further characterized the order are affected by the severity of the disorder and how condition in 1901, and F. Parkes Weber described many it is managed, although anyone with the disorder may cases of the vascular problems as well. OWR is caused experience life-threatening attacks of acute hyperam- by a genetic defect in the development of blood capillar- monemia. Capillaries are vessels that exist between arteries and appears to be a difficult time for those with OTC defi- veins, connecting them throughout the body. The abnor- ciency, and persons who survive until after puberty have mality causes the capillaries to end bluntly, so they can- improved outcomes. Because of vary from quite hopeful to very distressing based upon its this, AVMs and telangiectases may result in various parts severity and how well the disorder can be controlled. Telangiectases on the skin represent a small AVM that has reached the outer surface of skin. Telangiectases Resources usually have thin walls and are quite fragile, so they may PERIODICALS burst spontaneously, causing bleeding. Occasionally, larger AVMs may exist in the brain, lungs, or stomach and this may lead to more seri- KEY TERMS ous bleeding. It is very rare for an individual to have all the symptoms typically found in OWR. Alteration—Change or mutation in a gene, specif- People with OWR do not have any mental limita- ically in the DNA that codes for the gene. However, if fatigue and other symptoms of ane- direct connection between the arteries and veins mia accompany the nosebleeds, they can pose great stress (blood vessels). OWR has the potential need for continual medical with a laser or electric needle to stop bleeding or management into adulthood, which can also be quite tax- destroy damaged tissue. Echocardiogram—A non-invasive technique, using ultrasonic waves, used to look at the various Genetic profile structures and function of the heart. OWR may be divided into two groups, OWR1 and Embolization therapy—Introduction of various OWR2. OWR1 is caused by alterations in the endoglin substances into the circulation to plug up blood (ENG) gene, located on the q (long) arm of chromosome vessels in order to stop bleeding. AVMs of the lung may be more Endoscopy—A slender, tubular optical instrument common in OWR1 than OWR2. OWR2 is caused by used as a viewing system for examining an inner alterations in the activin receptor-like kinase 1 gene part of the body and, with an attached instrument, (ALK1), located on the q arm of chromosome 12 at band for biopsy or surgery. Normally, ENG and ALK1 make proteins that are important in blood vessel formation. Therefore, alter- Magnetic resonance imaging (MRI)—A technique ations within these genes would naturally cause problems that employs magnetic fields and radio waves to with blood vessels. The causes of OWR are complex; create detailed images of internal body structures various alterations in multiple genes, or various alter- and organs, including the brain. Stroke—A sudden neurological condition related to a block of blood flow in part of the brain, which OWR is inherited in an autosomal dominant manner. As of 2000, nearly all affected peo- Telangiectasis—Very small arteriovenous malfor- ple have a family history of OWR, which is typically a mations, or connections between the arteries and parent with the condition.

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Opioid tolerance develops stimulants buy viagra super active 100 mg on line, which include cocaine buy 100mg viagra super active, amphetamine quality viagra super active 25mg, metham- more quickly and to a greater extent than it does for phetamine (Desoxyn) buy cheap viagra super active 100 mg, methylphenidate (Ritalin) cheap viagra super active 50mg with amex, and most other drugs of abuse. Tolerance develops within a few days if potent opioids are given at frequent intervals, such as every 4 Extent and Pattern of Abuse to 6 hours. Development of tolerance requires several Sympathomimetic stimulant drugs have very high abuse weeks if the opioid is given only twice a day. They are typically used repeatedly for a short The continued use of opioids results in the develop- period during which time the user escalates the dose to ment of physical dependence, as demonstrated by the greater and greater levels to attain the desired degree of appearance of a characteristic abstinence syndrome euphoria. The symptoms of 24 to 72 hours is often referred to as a run and usually withdrawal include hyperactivity, anxiety, restlessness, ends in a crash (24–36 hours of sleep) once the individ- yawning, diarrhea, vomiting, chills, fever, lacrimation, ual is exhausted physically. Piloerection (gooseflesh or cold stimulants, approximately 5 billion doses of these drugs turkey), mydriasis, increased blood pressure and heart are prescribed per year, and there appears to be a sig- rate, and hyperpyrexia may be observed. Drug craving is an important feature of opioid with- methylphenidate, are taken orally, others are either drawal. In contrast to some other drugs of abuse, volatilized for inhalation or snorted as the solid (nasal withdrawal is not life threatening. It is necessary to convert cocaine and methamphetamine to their free base so that they can be Treatment of Opioid Dependence volatilized. Although the ultimate goal of treatment programs is to achieve drug-free status as quickly as possible, it is Pharmacological Aspects rarely achieved without pharmacotherapy. The most commonly used strategy is to switch the patient from a Most of the sympathomimetic stimulants exhibit similar short-acting opioid, such as heroin, to a long-acting ag- pharmacological properties, differing primarily in the 35 Contemporary Drug Abuse 411 magnitude of their effects. Intravenous injections of cocaine and amphetamine can Pharmacological Actions produce a very intense rush of sensations that resemble sexual orgasm. At small doses cognition increases and The behavioral effects of nicotine have been defined as mood is elevated. As the dose of drug escalates during a both stimulant and depressant, effects that are influ- run, the overall activity of the individual changes from enced by the present mental status and expectations of task performance to one generally characterized by the smoker. The person starts performing Nicotine produces myriad effects on the central nervous certain behaviors repeatedly. Acute toxic prominent effects is stimulated release of dopamine, paranoid psychosis can develop, but it usually requires particularly in the nucleus accumbens, which is a major a longer period of abuse than a single acute session. Nicotine also stimu- Besides stimulating the CNS, these drugs activate lates the release of endogenous opioids and glucocorti- the autonomic nervous system. It has been pro- Mechanism of Action posed that rapid tolerance or desensitization occurs to The sympathomimetic drugs are discussed in Chapter the behavioral or reinforcing effects of nicotine. In brief, the most commonly abused of these drugs, effects are of such a short duration that a smoker con- such as cocaine, work primarily as indirect agonists of tinually cycles between a sensitized and desensitized the catecholamine neurotransmitter systems via in- state. This notion is consistent with the fact that drugs hibitory actions upon the transmitter reuptake system. There is also Regardless of the mechanism of tolerance, nicotine evidence that blockade of serotonin uptake may con- is a highly addicting drug. Although most smok- Tolerance and Dependence ers wish to quit, only about one-third attempt to do so Tolerance to stimulants develops fairly rapidly, even in each year. SEDATIVE–HYPNOTICS The CNS depressants include barbiturates, nonbarbitu- Other Adverse Effects of Chronic Abuse rate sedatives, and the benzodiazepines. As the medical Chronic stimulant abuse alters the personality of the use of barbiturates decreased, primarily because of abuser. These and related changes are the result of neu- their high addiction liability and the danger of acute rotoxicity and are not characterized as either acute drug lethality, the use of the benzodiazepine anxiolytics in- effects or withdrawal signs. The most commonly abused barbiturates are of being pursued or persecuted and therefore become secobarbital, pentobarbital, and amobarbital. They become self-occupied barbital is not generally abused, because of its slow on- and hostile toward others. The most commonly abused anxiolytics duce toxic psychosis that closely resembles schizophre- include diazepam, chlordiazepoxide, midazolam, lo- nia and must be treated with neuroleptic drugs razepam, and flurazepam. Withdrawal symptoms following long-acting benzodiazepines (diazepam, clorazepate) CNS depressants, including barbiturate, benzodiazepine, peak during the second week of abstinence. These drugs to alcohol and the barbiturate sedatives, withdrawal are abused for their euphoric effects and as a means to from benzodiazepines is not life threatening.

The most common clinical features are risk for having another child with the disorder is 25% in hair loss (alopecia) order 50mg viagra super active mastercard, skin rash (dermatitis) buy viagra super active 50 mg low price, seizures (con- each subsequent pregnancy purchase viagra super active 100 mg on line. As of 1999 cheap 100 mg viagra super active otc, at least 40 differ- prone to fungal and bacterial infections buy viagra super active 100 mg low price, suggesting that 158 GALE ENCYCLOPEDIA OF GENETIC DISORDERS the immune system is also affected. Symptoms are highly Treatment and management variable among affected individuals even, within a single Treatment of the profound form of biotinidase defi- family. Biotinidase deficiency is classified as either partial Partial deficiencies are usually treated with lower doses. If there is at least 10% enzyme activity, the The biotin must be in a free form; that is, not attached to deficiency is considered partial and is usually associated other molecules as would be the case with the biotin with minimal to mild symptoms. Properly treated, biotinidase deficiency is deficiency, defined as less than 10% of normal activity, not a life-threatening condition, but biotin treatment must is characterized by many of the symptoms mentioned continue throughout life. No treatment is needed before above, and can, if left untreated, result in coma and birth because the developing fetus is provided with suffi- death. Prognosis Diagnosis Daily treatment with free biotin usually results in Children with profound biotinidase deficiency may rapid improvement of the skin condition, hair regrowth, show general signs such as vomiting, seizures, and low and a lessening or cessation of seizure activity. Many muscle tone, all of which can be associated with a num- children whose development has been affected by bio- ber of different disorders. Diagnosis can be difficult tinidase deficiency have shown some improvement after because of the many different enzyme deficiencies treatment. For example, abnormally high amounts of screening programs rarely develop symptoms if they are certain acidic products in the blood and urine can be typ- started on biotin replacement therapy immediately. Accurate diagnosis is made by Resources measuring the activity of the enzyme in blood or skin BOOKS cells. DNA tests can usually detect the particular gene mutation ORGANIZATIONS in any affected individual or carrier. If a couple has had one child with biotinidase defi- WEBSITES ciency, they can be offered prenatal testing in future preg- “Biotinidase. A Alternatively, if specific gene mutations have been iden- Booklet for Families and Professionals. Sallie Boineau Freeman, PhD GALE ENCYCLOPEDIA OF GENETIC DISORDERS 159 does not worsen the disorder or change the age of onset. IBipolar disorder It is currently thought that expression of BT II involves multiple mutated genes. Further research is ongoing to Definition determine precise mechanisms and to develop genetic Bipolar disorder is characterized by mood swings, markers (gene tags) for predicting which individuals are which are unpredictable and range from mania (elevated at higher risk. The disorder causes sig- Demographics nificant difficulties or impairment in social, occupational, and general functioning capabilities. Manic-depression is a common psychological disor- der that is difficult to diagnose (detect). It is estimated that about three million people in the United States are Description affected. Community oriented studies suggest that the Bipolar Type II (BT II) disorder is a psychological lifetime prevalence (number of cases in terms of time) is disorder characterized by fluctuation of cycles (time peri- approximately 0. Women have been observed at is commonly associated with irritability, decreased need increased risk of developing subsequent episodes in the for sleep (sleep disruption), euphoria (an exaggerated immediate period after giving birth. After treatment, most false self-perception of feeling good), social extroversion patients with BT II return to fully functional levels. The depressive episode or ing due to persistent mood changes, which continues to cycle is correlated with a broad spectrum of symptoms. Most patients in depressive cycles exhibit common symptoms, which include fatigue, impaired concentra- Signs and symptoms tion/decision making, and altered sleep and appetite pat- terns. This cycle can further progress to the level where The following signs and symptoms are indicative of patients feel excessively shameful and guilty. In totality, bipolar disorder: the symptoms for the depressive cycle can lead to 1. The disorder is also called • Feeling sad or empty Manic-Depressive Psychosis, and Major Affective Disorder. Studies have shown monozygotic • Thinking and moving in an agitated or slowed twins (identical twins) have an 80% concordance rate manner (presence of the same disorder in twins).

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The prognosis for children with MPS I H/S these disorders are also known as lysosomal storage is variable with some individuals dying during childhood 50 mg viagra super active amex, diseases generic viagra super active 50 mg overnight delivery. MPS I MPS I S (SCHEIE SYNDROME) Scheie syndrome is considered the mild form of MPS I buy viagra super active 25mg line. It is estimated that MPS I is caused by a deficiency of the enzyme approximately one baby in 500 generic viagra super active 25mg otc,000 will be born with alpha-L-iduronidase purchase viagra super active 25mg with amex. Individuals with MPS I S usually have Scheie, and Scheie syndromes, are all caused by a defi- ciency of this enzyme. Initially, these three conditions normal intelligence, but there have been some reports of were believed to be separate because each was associated individuals with MPS I S developing psychiatric prob- with different physical symptoms and prognoses. Common physical problems include corneal cloud- However, once the underlying cause of these conditions ing, heart abnormalities, and orthopedic difficulties was identified, it was realized that these three conditions involving their hands and back. The gene involved do not develop the facial features seen with MPS I H and with MPS I is located on chromosome 4p16. All individuals with Cardiomyopathy—A thickening of the heart Hunter syndrome are male, because the gene that causes muscle. Like many MPS conditions, Hunter syn- Enzyme—A protein that catalyzes a biochemical drome is divided into two groups, mild and severe. It has reaction or change without changing its own been estimated that approximately one in 110,000 males structure or function. Males with the cells, containing many hydrolytic enzymes; where mild form of Hunter syndrome develop physical differ- large molecules and cellular components are bro- ences similar to males with the severe form, but not as ken down. Men with mild Hunter syndrome can have a nor- Mucopolysaccharide—A complex molecule made mal life span and some have had children. Most males of smaller sugar molecules strung together to form with Hunter syndrome develop joint stiffness, chronic a chain. Found in mucous secretions and intercel- diarrhea, enlarged liver and spleen, heart valve problems, lular spaces. These symptoms tend to progress at a different Recessive gene—A type of gene that is not rate depending on if an individual has the mild or severe expressed as a trait unless inherited by both form of MPS II. X-linked gene—A gene carried on the X chromo- MPS III (Sanfilippo syndrome) some, one of the two sex chromosomes. MPS III, like the other MPS conditions, was initially diagnosed by the individual having certain physical char- acteristics. It was later discovered that the physical symp- MPS IIIA (SANFILIPPO SYNDROME TYPE A) MPS IIIA toms associated with Sanfilippo syndrome could be is caused by a deficiency of the enzyme heparan N-sulfa- caused by a deficiency in one of four enzymes. Type IIIA is felt to be the most severe of the four of MPS III is now subdivided into four groups, labeled A- types, in which symptoms appear and death occurs at an D, based on the specific enzyme that is deficient. A study in British Columbia estimated that of these enzymes are involved in breaking down the same one in 324,617 live births are born with MPS IIIA. Heparan sulfate is mainly found in IIIA is the most common of the four types in the central nervous system and accumulates in the brain Northwestern Europe. The gene that causes MPS IIIA is when it cannot be broken down because one of those four located on the long arm of chromosome 17 (location enzymes are deficient or missing. MPS III is a variable condition with symptoms MPS IIIB (SANFILIPPO SYNDROME TYPE B) MPS IIIB beginning to appear between ages two and six years of is due to a deficiency in N-acetyl-alpha-D-glu- age. This type of MPS III is not felt to the central nervous system, the central nervous system is be as severe as Type IIIA and the characteristics vary. In MPS III, signs that the central nerv- Type IIIB is the most common of the four in southeastern ous system is degenerating are usually evident in most Europe. Many children with located on the long arm of chromosome 17 (location MPS III will develop seizures, sleeplessness, thicker 17q21). The life ciency in the enzyme acetyl-CoA-alpha-glucosaminide expectancy in MPS III is also variable. This is considered a viduals with MPS III live until they are teenagers, with rare form of MPS III. GALE ENCYCLOPEDIA OF GENETIC DISORDERS 755 MPS IIID (SANFILIPPO SYNDROME TYPE D) MPS IIID MPS VII (Sly syndrome) is caused by a deficiency in the enzyme N-acetylglu- MPS VII is an extremely rare form of MPS and is cosamine-6-sulfatase. It is also highly variable, but symptoms are arm of chromosome 12 (location 12q14).

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