By E. Renwik. Fisk University.
International Collaborative Study Group for Bartter-like Syndrom es buy 100 mg viagra professional otc. M adias N E discount viagra professional 50mg with visa, Adrogué H J, Cohen JJ: M aladaptive renal response to M utations in the gene encoding the inwardly-rectifying renal potassi- secondary hypercapnia in chronic m etabolic alkalosis. Am J Physiol um channel, RO M K, cause the antenatal variant of Bartter syndrom e: 1980, 238:F283–289. H arrington JT, H ulter H N , Cohen JJ, M adias N E: M ineralocorticoid- 31. Beall DP, Scofield RH : M ilk-alkali syndrom e associated with calcium 12:24–30. This syndrome is characterized by a sudden decrease in kidney function, with a conse- quence of loss of the hemostatic equilibrium of the internal medium. The primary marker is an increase in the concentration of the nitroge- nous components of blood. A second marker, oliguria, is seen in 50% to 70% of cases. In general, the causes of ARF have a dynamic behavior as they change as a function of the economical and medical development of the community. Economic differences justify the different spectrum in the causes of ARF in developed and developing countries. The setting where ARF appears (community versus hospital), or the place where ARF is treated (intensive care units [ICU] versus other hospital areas) also show differences in the causes of ARF. W hile functional outcome after ARF is usually good among the sur- viving patients, mortality rate is high: around 45% in general series and close to 70% in ICU series. These age and severity factors, together with the more aggressive therapeutical possibilities presently available, could account for this apparent paradox. As is true for any severe clinical condition, a prognostic estimation C H A P T ER of ARF is of great utility for both the patients and their families, the medical specialists (for analysis of therapeutical maneuvers and options), and for society in general (demonstrating the monetary costs of treatment). This chapter also contains a brief review of the prog- nostic tools available for application to ARF. Acute renal failure is a monoxide, mercurial chloride, stings; drugs such as fibrates, statins, opioids and amphetamines; hereditary diseases such as muscular dystrophy, syndrom e characterized by a sudden decrease of the glom erular metabolopathies, McArdle disease and carnitine deficit filtration rate (GFR) and consequently an increase in blood Hemoglobinuria: malaria; mechanical destruction of erythrocytes with extracorporeal nitrogen products (blood urea nitrogen and creatinine). It is circulation or metallic prosthesis, transfusion reactions, or other hemolysis; associated with oliguria in about two thirds of cases. Depending heat stroke; burns; glucose-6-phosphate dehydrogenase; nocturnal paroxystic on the localization or the nature of the renal insult, ARF is classi- hemoglobinuria; chemicals such as aniline, quinine, glycerol, benzene, phenol, fied as prerenal, parenchym atous, or obstructive (postrenal). Prerenal ARF, also known as prerenal urem ia, supervenes when glom erular filtration rate falls as a consequence of decreased effective renal blood supply. The condition is reversible if the underlying disease is resolved. FIGURE 8-3 Causes of parenchym al acute renal failure (ARF). W hen the sud- den decrease in glom erular filtration rate that characterizes ARF is secondary to intrinsic renal dam age m ainly affecting tubules, interstitium , glom eruli and/or vessels, we are facing a parenchy- m atous ARF. M ultiple causes have been described, som e of them constituting the m ost frequent ones are m arked with an asterisk. During the last years, acute tubulointerstitial nephritis is increasing in importance as FIGURE 8-5 a cause of acute renal failure. For decades infections were the most Causes of obstructive acute renal failure. At present, antimicrobials and other drugs are the the urinary tract frequently leads to acute renal failure. FIGURE 8-6 Arterial disease Other parenchymal This figure shows a comparison of the percent- 2. This low rate of prerenal ARF has been observed by other workers in an intensive care setting. FIGURE 8-7 FINDINGS OF THE M ADRID STUDY Incidences of different form s of acute renal failure (ARF) in the M adrid ARF Study. Figures express cases per m illion persons per year with 95% confidence intervals (CI). Condition Incidence (per million persons per year) 95% CI Acute tubular necrosis 88 79–97 Prerenal acute renal failure 46 40–52 Acute on chronic renal failure 29 24–34 Obstructive acute renal failure 23 19–27 Glomerulonephritis (primary or secondary) 6. This algorithm could help Normal or big kidneys to determ ine the cause of the increase in Small kidneys (excluding amiloidosis and blood urea nitrogen (BUN ) or serum polycystic kidney disease creatinine (SCr) in a given patient.
More recently buy viagra professional 50mg with visa, the National Comorbidity Survey (NCS) found that 24 discount viagra professional 100 mg mastercard. The two studies used somewhat different A specific phobia is diagnosed if a child consistently displays sampling methods, and different diagnostic interviews, significant and excessive fear in response to a specific object probably therein explaining at least some of the variance in or situation (18). The most common fears among children rates between studies (47). The prevalence of this disorder is in the range of 0. Comorbidity among the anxiety, mood, and substance use Unlike the other anxiety disorders reviewed here, chil- disorders is extensive (47). For example, two-thirds of per- dren with specific phobias remain a fairly distinct group. In a clinical sample of 85 patients were least likely to show onset of a different disorder within with major depression, 29% met criteria for a current anxi- the follow-up period. What is particularly noteworthy about this relationship Chapter 60: Anxiety and Stress Disorders: Course over the Lifetime 863 is the temporal sequencing of disorders. Certain anxiety dis- also provide persuasive evidence of the seriousness of anxiety orders, social phobia in particular (which has a median onset disorders (52,63,64). The annual cost of anxiety disorders of between 13 and 15 years of age), almost inevitably begin in the United States was estimated at $42. In one study of depressed patients, social phobia anxiety disorders analyzed were associated with impairment was the most common lifetime anxiety disorder (occurring in workplace performance. These observations, gleaned in 15% of cases) followed closely by panic disorder with from a variety of clinical and nonclinical perspectives, por- agoraphobia (in 12%) (49). Social phobia occurred on aver- tray anxiety disorders in adults as serious mental disorders age 2 years prior to the onset of major depressive disorder worthy (and in need) of greater societal willingness to de- in these patients. Similar findings have emerged from com- velop and apply better interventions to prevent or mitigate munity studies (52), suggesting that particular anxiety disor- their impact on the lives of individuals. It re- mains to be established what the mechanisms might be for ANXIETY AND STRESS DISORDERS IN this observed relationship. Does being socially anxious lead OLDER ADULTS to increased isolation or decreased self-worth, thereby lead- ing to an increase in subsequent major depression? Is social Although anxiety is among the most prevalent of psychiatric phobia merely the earliest manifestation of an anxiety-mood disorders in the elderly, research in this area has lagged far disorder diathesis? These questions will only be answered behind that of depression and dementia (66). But in the with future research that focuses broadly on psychosocial past fewyears, several important studies have been con- and biological vulnerabilities for anxiety and mood disor- ducted that provide novel information about the prevalence, ders. Another interesting aspect of the anxiety-depression link lies in the relationship between major depressive disorder Epidemiology (MDD) and PTSD. Extensive comorbidity between PTSD and MDD is the norm in studies of various traumatized Whereas it had previously been believed that anxiety disor- groups, including persons exposed to combat (53,54), disas- ders decline in prevalence with age, several possible explana- ters (55), and intimate partner violence (56). Community tions for this finding have been put forward. It has been studies also demonstrate strong ties between these two disor- suggested that this might be an artifact of measurement ders, with approximately 35% to 50% of cases of PTSD in error, owing to differences in the way older individuals re- the general population being comorbid with MDD (57). Previous epidemiologic studies may also Studies that have examined the temporal association be- have underestimated the prevalence of anxiety disorders in tween major depression and PTSD have posited several the elderly by limiting participation to community-dwelling causal pathways. The con- Fortunately, data have recently become available from a verse has also been observed, namely that preexisting PTSD newcommunity survey that provides a more accurate and is a risk factor for the later development of MDD (58,60). The Longitudinal Aging Study Amsterdam (LASA) is to be explained, but might involve a general vulnerability based on a random sample of 3,107 older adults (ages 55 to stress that can result in major depression (61) or PTSD to 85), stratified for age and sex. The overall prevalence of in susceptible individuals. For comparison purposes, it is noteworthy that the Society 6-month prevalence of major depression in the same study Data have been collected in the past several years that high- was 2. Thus, anxiety disorders were far more common light the disability and reduced quality of life associated than depressive disorders in the elderly, underscoring the with anxiety disorders in young and middle-aged adults. Many of the vulnerability logic studies, where the range of severity is expected to be factors for anxiety disorders in younger adults are common wider and where many milder cases are expected to be seen, to older adults (e. These investigators were also able to show that current Anxiety disorders span the full range of human existence stresses commonly experienced by older people (e.
It has recently become possible to cation of Ca2 -permeable AMPA and KA receptors by in- overcome these limitations on both spatial and biochemical ducing a voltage-dependent channel blockade (19) cheap viagra professional 50 mg without prescription. This capacity is a direct result of molecular neuro- acid was used as a non–NMDA receptor agonist; however generic viagra professional 100mg amex, biological analyses that have fostered a detailed understand- its specificity for AMPA receptors is poor as it also activates ing of the subunit protein constituents of the three classes mGluR 1 and 5 metabotropic receptors and inhibits gluta- of inotropic GluRs, and thus allowed for in situ hybridiza- mate carboxypeptidase II (GCPII) (20,21). The conforma- tion to be used to localize specific mRNAs (28) and with tional rigidity of AMPA provides good specificity for AMPA the use of class and subunit-specific antibodies for immuno- receptors, whereas the more flexible kainic acid interacts cytochemistry, it is now feasible to analyze GluR distribu- with KA receptors as well as other types of iGluRs. The tion at the highest levels of cellular and synaptic resolution orientation, length, and saturation of the side chain of kainic (29,30). Although early studies demonstrated a wide distri- kainate (22). The first potent selective antagonists at bution of AMPA subunits GluRs 2/3 in the brain and spinal AMPA/KA receptors with negligible effects at NMDA re- cord (31–34), it became clear early on that the relationship Chapter 6: L-Glutamic Acid in Brain Signal Transduction 73 between GluRs and specific circuits needed to be analyzed the localization patterns at the synaptic level. This was rein- at a high level of resolution; colocalization studies directed forced in studies of GluR2/NR1 colocalization in hippo- at subsets of neurons (29,35–38) and ultrastructural dissec- campus and neocortex, designed to delineate the degree of tion of the synapse (39–44). A key theme that emerges synaptic colocalization of NMDA and AMPA receptors in from these studies is that regional distribution and cellular asymmetrical synapses (39–43). Although NR1 and GluR2 colocalization patterns should not be extended to a synaptic are broadly colocalized on a cellular level, extensive synaptic interpretation: Such interpretations must be founded on heterogeneity exists in their representation. NR1 and GluR2 ultrastructural data as seen in the following examples. For example, electrophysiological analyses have spines. In addition, early play a dominant role in mediating EPSCs. A physiologic reports using polyclonal antisera that did not differentiate role for KA receptors has been elucidated only recently with among GluR2, 3, and 4c, obtained results implying that the development of more selective agonists and antagonists. GABAergic interneurons might not contain GluR2, 3, and In the hippocampal slice in which the AMPA, NMDA, 4C (49–51). This current is absent in mice homo- followed by a rabbit polyclonal (53) were developed. The zygous for null mutation of the GluR6 subunit and less GluR2 antibodies showed that virtually all pyramidal cells vulnerable to the epileptogenic effects of systemic KA (59). A similar pattern was found CA 1 region of the hippocampus is mediated by the GluR5 in hippocampus, suggesting that the majority of the GA- subunit (60). BAergic interneurons in hippocampus are GluR2-positive, Although KA subunits have not been localized as exten- although a subset of GABAergic neurons lacks any detecta- sively at the ultrastructural level as have AMPA or NMDA ble GluR2 (52,53), as in neocortex. These results are in receptors, immunocytochemical studies have demonstrated excellent accord with the GluR2 mRNA results obtained their broad distribution in the hippocampus and neocortex by single cell RT-PCR studies (45,46), and suggest that a and broad colocalization with AMPA and NMDA receptor minority of the GABAergic interneurons lack GluR2 subunits (38,61) in both pyramidal and GABAergic in- mRNA/protein. Thus, the differences in calcium permeabil- terneurons (35,36). A double label GABA/GluR2 analysis that was extended The NMDA receptor, as its name indicates, was identified to the ultrastructural level further clarified the issue of by the selective excitatory effects of the synthetic analogue GluR2 representation in GABAergic interneurons (54). A number of was hypothesized that if the difference in calcium perme- properties distinguishes the NMDA receptor from the ability between pyramidal and GABAergic neurons was re- non–NMDA iGluRs. Sec- Ultrastructural analysis revealed that there is a consistently ond, the receptor requires occupancy of another ligand lower number of immunogold particles at the labeled asym- binding site, the so-called glycine modulatory site, in order metric synapses on GABAergic dendrites than those on py- for glutamate to gate channel opening. Recent evidence in- ramidal cell dendrites or spines, suggesting that a cell class- dicates that not only glycine but also D-serine, which is specific difference in synaptic abundance of GluR2 is the synthesized in astrocytes by serine racemase, is a potent en- substrate for the observed differences in calcium permeabil- dogenous agonist at the glycine site (62). Third, the NMDA ity across these two cell classes revealed electrophysiologi- receptor possesses a number of modulatory sites of physio- cally (45,46). Zn2 is a potent inhibitor of NMDA As demonstrated in the GluR2 studies discussed in the receptor conductance, especially those containing the 2 preceding, cellular colocalization may not adequately reflect NR2A subunit (24). Zn is concentrated in some gluta- 74 Neuropsychopharmacology: The Fifth Generation of Progress matergic terminals (e. These studies have been followed with glutamate (63). A binding site for polyamines, when occu- very extensive immunocytochemical analyses, particularly pied, enhances conductance in part through increasing the of the obligatory subunit NR1.
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