Lactate infusions: The ogy procyclidine 5mg for sale medications medicaid covers, parenting styles and the risk of social phobia in offspring: a role of baseline anxiety cheap procyclidine 5 mg fast delivery medicine 2 times a day. Philos Trans R Soc on brain systems involved in the pathophysiology of anxiety Lond [B] 1997;352:1755–1759 quality procyclidine 5 mg symptoms 4 days before period. Fear and the brain: where have we been, and where 169. The emotional Stroop section with anxiety disorders. Biol Psychiatry 1999;1999: task and psychopathology. The adolescent brain and age-related behavioral mani- and its amelioration by effective treatment with SSRis. KALIN ANIMAL MODELS OF PSYCHIATRIC fore, it is difficult to come up with an animal model for an ILLNESS illness that meets the aforementioned criteria and also models the pathologic syndrome in its entirety. An alterna- Animal Models: Types Of Validity tive approach that has been used involves the modeling of An important criterion for developing animal models to discrete symptom clusters and physiologic alterations rather study psychopathology involves establishing the validity of than the whole syndrome, with the assumption that what the model as a true representation of the process being stud- causes the symptoms contributes mechanistically to the ill- ied. Generally, three types of validity are applied to animal ness. This general approach has involved the use of endo- models: face validity, construct validity, and predictive va- phenotypes that may be related to a particular psychiatric lidity (1–3). Face validity refers to the outward similarity disorder. The term endophenotype refers to a set of behavioral in appearance between the model and the illness. Construct and/or physiologic characteristics that accompany a basic validity, on the other hand, does not exclusively involve process that is altered in relation to the illness that is being outward tangible signs of the modeled illness. It is important to note that this more narrowly refers to the internal mechanism or state that underlies the defined endophenotype approach does not necessarily have illness. Finally, predictive validity refers to the ability of to capture specific symptoms that are a part of the clinical the animal model to identify therapeutic treatments for the diagnosis, but rather may focus on a core process or function illness. It should be noted that the different types of validity that is abnormal in the clinical population under study and can be independent of each other; an animal model can that is thought to be related to the manifestation of the possess predictive and construct validity without possessing illness. For example, in the case of anxiety-related disorders, face validity. Ideally, an animal model should possess both investigators have focused on studying the genetic, physio- construct and predictive validity so that it may be used to logic, and neurochemical correlates of fearful or anxious understand the mechanisms and etiology of the disorder endophenotypes because a core aspect of anxiety-related dis- and also to identify promising treatments for the disorder. Thus, by identify- Endophenotype Approach ing animals that display fearful endophenotypes, it is possi- ble to study the neural substrates that contribute to this Species differences in the manifestation of a particular inter- basic process that may underlie the development and expres- nal state can cloud the usefulness of face validity in animal sion of anxiety-related psychopathology. In addition, when considering a complex psychiat- Using endophenotypes that are based on core and basic ric illness, it is likely that several different symptom clusters processes rather than the entire illness offers certain advan- contribute to the final pathologic condition; these different tages. Because the whole illness is not being modeled, the sets of symptoms may have different underlying substrates endophenotype approach affords greater possibility for con- and thus may be ameliorated by different treatments. There- struct and predictive validity in the model, and can incorpo- rate species-specific manifestations of the core process being modeled. This approach may also make screening for ge- VaishaliP. Kalin: DepartmentofPsychiatry,Univer- sity of Wisconsin at Madison, Wisconsin Psychiatric Institute and Clinics, netic abnormalities associated with the disorder more fruit- Madison, Wisconsin. Moreover, heterogeneity among other variables, the nature of the perceived threat within a diagnostic category could potentially dilute the (14,15). Studies of defensive behaviors in rhesus monkeys strength of a sample population (i. Ideally, one might be able to generate occur in dispositionally fearful humans who have an in- several different endophenotypes for a particular disorder, creased risk to develop psychopathology (16). In other words, pathologic anxiety could be concep- definition and use of endophenotypes in animal models of tualized as the inappropriate expression of defensive or fear- psychiatric illness is a developing area. This chapter presents related behaviors, consisting of either an exaggerated or some promising candidates of animal models of fearful and overly fearful response to an appropriate context, or a fearful anxious endophenotypes, and outlines some of the prelimi- response to an inappropriate or neutral context. Although nary genetic factors that have been identified to contribute appropriate levels of defensive behaviors in response to envi- to the manifestation of these endophenotypes. Thus, in- FEARFUL TEMPERAMENT appropriate or exaggerated expression of defensive behaviors may represent an important animal endophenotype of anxi- Defensive Behaviors ety. An understanding of the specific neural substrates un- In an attempt to understand the basic neural mechanisms derlying the expression and regulation of defensive behav- underlying psychiatric conditions involving fear and anxi- iors may therefore ultimately shed insight into the processes ety, several groups have focused on identifying the neural that become dysregulated in stress-related psychopathology.
These characteristics suggest 65% to 90% of D2R2 is correlated with a therapeutic dose that olanzapine differs from clozapine procyclidine 5mg discount medicine identification. Additionally discount 5mg procyclidine visa medications beginning with z, quetia- of typical neuroleptics as well as other clinical manifestations pine is characterized by abatement of psychotic symptoms of pharmacologic efficacy procyclidine 5mg with amex medications images. For example, patients with acute in association with a transient increase in D R occupancy 2 extrapyramidal side effects were found to have higher DA (62). Wolkin and colleagues (1989) found a comparable occupancy of haloperidol in responders versus nonrespond- Receptor Occupancy as a Surrogate ers indicating that treatment nonresponse is not a function Marker of Clinical Efficacy? Kapur and colleagues recently confirmed that the D2 One of the most important questions about D2R and occupancy is an important mediator of beneficial and ad- 5HT2A receptor occupancy is the prediction of doses yield- verse effects (101) in a study of first episode schizophrenia ing clinical efficacy. D2R occupancy predicted the clinical and haloperidol. Although the patients showed a wide range improvement of 22 first episode schizophrenic patients ran- of D2R occupancy (38% to 87%), the degree of D2R occu- domly assigned to 1 or 2. Thus, D2R occupancy is related to the clinical and extrapyramidal side effects. Also, Daskalakis and associ- response to antipsychotics (99,109,110). D R occupancy occur at very low haloperidol doses (111). Kapur Receptor Occupancy by Atypical and colleagues (1997) also showed D2 occupancies between Neuroleptics of 53% to 88% for haloperidol doses of 1 to 5 mg. Thus, the conventional therapeutic practice of haloperidol doses of D2R occupancy has been determined for humans treated greater than 10 mg/day is too high for many schizophrenic with atypical neuroleptics. For example, receptors of people patients because there is no increase in beneficial effect, treated with clozapine exhibit low (20% to 65%) D2R occu- pancy and high serotonin type 2A (5HT ) receptor occu- whereas the riskof adverse effects increases in proportion to 2A pancy (94,99,103). In studies directly comparing clozapine the dose (112). Nevertheless, Volavka and colleagues (113) (450 mg/day) and haloperidol (5 mg/day), there was a rever- (1995) showed that antipsychotic efficacy of haloperidol sal of receptor occupancy producing high D blockade with increases with plasma levels up to 12 ng/mL, plasma levels 2 haloperidol and high 5HT blockade with clozapine. In- that would predict almost completely saturated D2 receptors 2A deed PET imaging has been an important approach for according to the Kapur and associates (1997) data (112). Risperidone has been shown to block40% to 60% with haloperidol plasma levels up to 15 ng/mL and almost of D receptors at only 1 mg (104) with even higher 5HT complete D2R occupancy saturation with haloperidol 2 2A receptor occupancy. Indeed, in patients with schizophrenia, plasma levels above 15 to 20 ng/mL (100). These differences oral dose of 6 mg risperidone, 75% to 80% of D2Rs and could be explained partly by the differences in radioligands 78% to 88% of 5HT2Areceptors are occupied (106). Further research by other investi- levels of risperidone correlate with D2R occupancy (107). The probability of acute dyskinesias is directly pro- of olanzapine (10 to 20 mg/kg) produce 71% to 80% D2R portional to the proportion of D2Rs occupied by the drug occupancy. These doses usually do not result in the adverse (99,110,115). Furthermore, receptor imaging demonstrates Chapter 34: Proof of Concept 465 a lower degree of D2 receptor occupancy during treatment most well developed area is in helping target rational drug with atypical neuroleptics. For example, PET has been used dosing as in the neuroleptic studies described in the preced- to obtain the minimal effective dose of risperidone. The second is the elucidation of the biodistribution of high D2R occupancy associated with 6 mg or more risperi- the drug by radiolabeling the drug or a derivative of the done daily suggests a high riskof acute dyskinesias. Examples of this application include the characteriza- other hand, 4 mg risperidone daily results in 70% to 80% tion of MDL, which is the first selective 5HT2A antagonist D2R occupancy and a lesser riskof acute dyskinesias (116). MDL has been ra- An additional role for occupancy studies in drug develop- diolabeled with [11C] in an isotopic form such that a stable ment takes the form of the interpretation of the time course carbon atom (atomic number 12C) is substituted with a of receptor occupancy following a single drug dose. Such radioactive atom (11C) without a change in the pharmacol- studies help determine the appropriate dosing regimen for ogy or chemistry. This procedure facilitates characterization future trials, such as once or twice a day dosing. For exam- of the biodistribution and washout characteristics of the ple, 70% to 90% of 5HT2A receptors are occupied during agent (117). One example of this is in the development results suggest that a 20-mg dose may be administered once of drugs for cocaine abuse. Unlike neuroleptics and antide- daily, whereas a 10-mg dose requires administration twice pressants, drugs developed to inhibit the action of cocaine a day. Thus, occupancy studies constitute surrogate markers have failed clinical trials. Although cocaine has been shown for the outcome variable and frequency of drug administra- to affect multiple neurotransmitter systems, current research tion.
Although usually not sensitive enough to detect the in STD clinic settings should be ofered hepatitis A vaccine: low level of protective antibody after vaccination buy generic procyclidine 5mg online symptoms rotator cuff tear, anti-HAV 1) all MSM; 2) illegal drug users (of both injection and non- tests also might be positive after hepatitis A vaccination purchase procyclidine 5 mg without a prescription permatex rust treatment. Patients with acute hepatitis A usually require only support- Prevaccination Serologic Testing for Susceptibility ive care generic procyclidine 5mg online medicine measurements, with no restrictions in diet or activity. Hospitalization might be necessary for patients who become dehydrated Approximately one third of the U. Recommended regimens: dose and schedule for hepatitis manifestations of hepatitis A in this age group; vaccine can be A vaccines used if IG cannot be obtained. Te magnitude of the risk for Two-dose schedule HAV transmission from the exposure should be considered in Vaccine Age (yrs) Dose Volume (mL) (months)* decisions to use IG or vaccine. IG should be used for children HAVRIX† 1–18 720 (EL. Prevention of hepatitis A through active or passive immunization: If IG is administered to persons for whom hepatitis A vac- recommendations of the Advisory Committee on Immunization Practices (ACIP). U = Enzyme-linked immunosorbent assay (ELISA) units; simultaneously with IG. Te efcacy of IG or vaccine when administered >2 † Hepatitis A vaccine, inactivated, GlaxoSmithKline Biologicals; this vaccine is weeks after exposure has not been established (438). Special Considerations § Hepatitis A vaccine, inactivated, Merck & Co. Limited data indicate that vaccination of persons with CLD and of persons with advanced HIV infection results in lower seroprotection rates and antibody concentrations (4). In HIV-infected persons, antibody response might be directly Screening for HAV infection might be cost-efective in popu- related to CD4+ levels. Te potential cost-savings of testing should Hepatitis B be weighed against the cost and the likelihood that testing will Hepatitis B is caused by infection with the hepatitis B virus interfere with initiating vaccination. Te incubation period from the time of exposure to who is already immune is not harmful. Te highest con- centrations of HBV are found in blood, with lower concentra- Postvaccination Serologic Testing tions found in other body fuids including wound exudates, Postvaccination serologic testing is not indicated because semen, vaginal secretions, and saliva (439,440). In addition, the com- infectious and relatively more stable in the environment than mercially available serologic test is not sensitive enough to other bloodborne pathogens like HCV and HIV. Risk for chronic infec- Persons who recently have been exposed to HAV and tion is inversely related to age at acquisition; approximately who previously have not received hepatitis A vaccine should 90% of infected infants and 30% of infected children aged <5 be administered a single dose of single-antigen vaccine or years become chronically infected, compared with 2%–6% of IG (0. Information about the persons who become infected as adults. Among persons with relative efcacy of vaccine compared with IG postexposure is chronic HBV infection, the risk for premature death from cir- limited, and no data are available for persons aged >40 years rhosis or hepatocellular carcinoma (HCC) is 15%–25%. Terefore, deci- HBV is efciently transmitted by percutaneous or mucous sions to use vaccine or IG should take into account patient membrane exposure to blood or body fuids that contain blood. In addition, several preferred over IG because of vaccine advantages, including studies have demonstrated the horizontal transmission of HBV, long-term protection and ease of administration. For persons including through premastication, as a less common source of aged >40 years, IG is preferred because of the absence of infor- transmission (441,442). Recommended doses of currently licensed formulations of adolescent and adult hepatitis B vaccines Single-antigen vaccine Combination vaccine Recombivax HB Engerix-B Twinrix* Group Dose (µg)† Volume (mL) Dose (µg)† Volume (mL) Dose (µg)† Volume (mL) Adolescents aged 11–19 years§ 5 0. A comprehensive immunization strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP) Part 1: immunization of infants, children, and adolescents. A comprehensive immuni- zation strategy to eliminate transmission of hepatitis B virus infection in the United States: recommendations of the Advisory Committee on Immunization Practices (ACIP) Part II: immunization of adults. This vaccine is recommended for persons aged ≥18 years who are at increased risk for both hepatitis B and hepatitis A virus infections. Persons with chronic and adolescents through age 18 years, and 4) vaccination of pre- HBV infection should be referred for evaluation to a physi- viously unvaccinated adults at increased risk for infection (3,4). Terapeutic High vaccination coverage rates, with subsequent declines in agents cleared by FDA for treatment of chronic hepatitis B acute hepatitis B incidence, have been achieved among infants can achieve sustained suppression of HBV replication and and adolescents (4,437,443). In contrast, vaccination coverage remission of liver disease in some persons. In addition, patients among most high-risk adult groups (e. IDUs) has remained low, and most new infections occur in Prevention these high-risk groups (3,108,444–446). STD clinics and other Two products have been approved for hepatitis B preven- settings that provide services to high-risk adults are ideal sites tion: hepatitis B immune globulin (HBIG) and hepatitis B in which to provide hepatitis B vaccination to adults at risk vaccine (3,4). All unvaccinated adults seeking services in protection from HBV infection and is typically used as PEP these settings should be assumed to be at risk for hepatitis B either as an adjunct to hepatitis B vaccination in previously and should be ofered hepatitis B vaccination. HBIG is prepared from plasma Diagnosis of acute or chronic HBV infection requires known to contain high concentrations of anti-HBs. Because HBsAg is present in both ommended dose of HBIG is 0. Antibody to HBsAg (anti- HBV infection when used for both pre-exposure vaccination HBs) is produced after a resolved infection and is the only and PEP. Te two available monovalent hepatitis B vaccines HBV antibody marker present after vaccination.