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The recommendations about the use of renal ultrasound scanning are based on knowledge of the information that an ultrasound scan provides silvitra 120 mg discount. Renal ultrasound can be used to confirm that people have two kidneys buy 120mg silvitra overnight delivery, to measure the size of the kidneys and to show structural abnormalities in the kidney such as polycystic kidneys buy discount silvitra 120mg on-line. Ultrasound scans can also be used to identify the presence of renal tract obstruction. Ultrasound may identify renal size discrepancy but where diagnosis or exclusion of renovascular disease is indicated additional imaging such as CT angiography or magnetic resonance renal angiography will be required (newer generation MR scanners may afford imaging of vessels without exposure to gadolinium and the attendant risks of nephrogenic systemic fibrosis). A renal ultrasound scan is always necessary before undertaking a renal biopsy. Ultrasound scanning cannot exclude the diagnosis of autosomal dominant polycystic kidney disease in people under the age of 20 and is therefore of limited use in people under this age with a family history of this condition. The GDG agreed that before undertaking a renal ultrasound scan in people at risk of kidney disease on the basis of a family history of inherited kidney disease, it was important that people were fully informed of the implications of an abnormal scan result. This should encompass counselling about the benefits of early identification of kidney disease but should also outline the social consequences of a diagnosis, including its effect on life insurance. Where indicated help to cope with the psychological consequences of a diagnosis should be offered. R19 Advise people with a family history of inherited kidney disease about the implications of an abnormal result before a renal ultrasound scan is arranged for them. To do this we need to know: q what the adverse outcomes are q at what level of GFR we should be alert to adverse outcomes and q the impact of associated factors such as age, gender and presence or absence of proteinuria at any given level of GFR. Large population studies have clearly suggested that the risk of death, hospitalisation and cardiovascular events rises exponentially at levels of GFR below 60 ml/min/1. The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) stratified chronic kidney disease into five stages according to glomerular filtration rate and the presence of kidney damage: q Stage 1: GFR >90 ml/min/1. CKD is common and its prevalence increases markedly with age, with a female predominance. However, the CKD classification is neither staged according to age and gender, nor according to level of proteinuria. All patients, regardless of age, gender and proteinuria or albuminuria are considered to have at least moderately severe CKD when their GFR is <60 ml/min/1. However, we have some evidence that GFR reduces as a consequence of ageing,112 although the exact level of reduction is still a subject of debate, and reduced GFR is very common in certain older populations. Long term, the ABLE study aims to identify the reasons for this faster deterioration. The degree of proteinuria is a significant risk factor both for progression of CKD and for cardiovascular disease. The recently published SIGN (Scottish Intercollegiate Guidelines Network) guideline also makes the same recommendation, as did the UK consensus conference on early CKD which also recommended sub-classifying CKD stage 3 into 2 groups: 3A which defines a lower risk group with GFR 45–59 ml/min/1. Baseline characteristics were significantly different between groups with lower eGFR compared with higher eGFR. People with low eGFR were almost always older, more likely to be female, and had higher prevalence of diabetes and cardiovascular diseases. While statistical analyses in these studies have been adjusted for confounding variables such as age, gender, race, and several comorbidities, it is difficult to identify all variables which could potentially affect the size of the risk. These unknown variables make it impossible to assign cause and effect, and the confidence intervals were sometimes so wide that the associations with eGFR could be spurious. Eight cohort studies examined the association between different eGFR levels and several outcomes of interest in populations with concomitant cardiovascular disease; specifically high-risk hypertension,118 acute myocardial infarction,119,120 heart failure,121 acute coronary syndrome,122 coronary disease,123 coronary artery disease124 and peripheral arterial disease. The mean age of people with higher eGFR (typically >60 ml/min/1. A very large US cohort study (N=1,120,295, follow-up 2. This study was rejected as there was little statistical analysis of the results; only mortality rates were presented. Quality of life outcomes such as cognitive impairment, frailty, and disability were assessed in postmenopausal women124 or in older populations with varying levels of serum creatinine132 or eGFR. The effects of age and gender on mortality and kidney disease progression were examined in people with stage 3 CKD in a Norwegian population study (N=3027, median observation time 3. The prevalence of frailty increased with decreasing GFR (p for trend <0. Black ethnicity and female gender were associated with increased likelihood of frailty. Black race and female gender were associated with increased likelihood of disability. There was NS risk of cognitive impairment at eGFR 45–49 or 30–44 ml/min/1. The risk of mortality was highest in those <60 years old. Again the risk was highest in those <60 years of age. Female gender was associated with an increased change in eGFR compared to men (+0. In an age- and sex- matched cohort, the matched risk ratio was 2. For people with proteinuria and eGFR 30–59 ml/min/1. For people with proteinuria and eGFR 15–29 ml/min/1. For people with proteinuria and creatinine clearance (CrCl) 64. ALL-HAT = Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial; ARIC = Atherosclerosis Risk in Communities; LVEF = left ventricular ejection; MI = myocardial infarction. Not all studies stratified patients according to whether or not they had diabetes and this may affect estimates of the risk of death. The evidence suggested that if the GFR is less than 60 ml/min/1. There was limited evidence about outcomes in older people. However, given that they are at increased absolute risk of mortality and cardiovascular events it was agreed that even small increases in relative risk in older people are of significance. The GDG considered that the evidence suggested that the risk of mortality and cardiovascular events increased considerably when the GFR was less than 45 ml/min/1. This led to the proposal to adopt the sub-division of stage 3 CKD into stages 3A and 3B, defined by an eGFR 45–59 ml/min/1. It was noted that the presence of proteinuria was associated with a doubling of CVD risk and mortality at all levels of GFR. Evidence from longitudinal population studies and from meta-analysis of progression risk and level of proteinuria suggested that an ACR ≥30 mg/mmol should be used as a marker of the increased risk (roughly equivalent to a PCR ≥50 mg/mmol or proteinuria values ≥0. The GDG agreed not to recommend age-related decision points for eGFR. However, it seemed clear that in people aged >70 years, an eGFR in the range 45–59 ml/min/1. R21 For the purposes of this classification define proteinuria as urinary albumin:creatinine ratio (ACR) ≥30 mg/mmol or PCR ≥50 mg/mmol (approximately equivalent to urinary protein excretion ≥0. Identification of high-risk groups can help clinicians monitor renal function and identify people with CKD at an earlier disease stage. Although general population screening may not be cost-effective, targeted screening directed at subgroups of the population who might derive the most benefit from CKD detection was shown to be an effective strategy. This work suggested that a vascular check programme would prevent 4000 people a year from developing diabetes and could also detect at least 25,000 cases of diabetes or kidney disease earlier. In those conditions where the prevalence of CKD is high and the risks of preventable complications are increased, testing for CKD is clearly warranted. The KEEP programme identified people with diabetes and hypertension, or people with a first-line relative (parent, grandparent, brother or sister) with diabetes, high blood pressure or kidney disease as being at high risk of CKD. Are there additional high-risk people who should be tested for CKD? The UK CKD guidelines also included those with a high risk of obstructive uropathy, all forms of CVD, multisystem diseases with the potential to involve the kidney such as SLE, and conditions requiring long-term treatment with potentially nephrotoxic drugs. A cohort study evaluated the risk of developing CKD in people with metabolic syndrome compared to those without metabolic syndrome (N=10,096, follow-up 9 years, Atherosclerosis Risk in Communities (ARIC) study cohort). A family history of ESRD was considered present if an incident ESRD patient reported having either a first-degree (parent, child, sibling) or second-degree (grandparent, aunt, uncle, grandchild, or half-sibling) relative with ESRD. This cohort study was excluded as 27% of the cohort did not have albumin excretion rate measurements and there were significant differences between those whose data were included and those whose data were not. The study mainly assessed the relationship between microalbuminuria and coronary heart disease, rather than ethnicity and the development of CKD. This study should be interpreted with caution as the multivariate analysis was restricted to N=2167, a loss of half of the study participants. In the NHANES III study, prevalence of severe or moderate CKD was compared between non- Hispanic black people (N=4163) and non-Hispanic white people (N=6635). Two US longitudinal studies examined the association between smoking and death due to CKD or development of ESRD. Each was based on a model and each measured health gain in terms of quality-adjusted life-years (QALYs). All three studies attributed the health gain to prescribing of ACE inhibitors or ARBs after diagnosis of proteinuria.
VII: Urinary cortisol activity (1 order 120mg silvitra mastercard,142) and appear to normalize with treat- free cortisol and urinary MHPG in depressions order silvitra 120 mg on-line. Low CSF somatostatin has also been observed in 1983;140:314–318 purchase 120mg silvitra otc. Plasma cortisol, catechol- amine and cyclic AMP levels, response to dexamethasone suppression test and platelet MAO activity in manic-depressive patients. Lithium carbonate Proliferation of research into the biology of depression has treatment of mania. Catecholamine metab- focused on single biological systems such that there is a olism, depressive illness and drug response. Arch Gen Psychiatry dearth of studies that simultaneously explore multiple sys- 1972;26:252–262. Chapter 72: Molecular and Cellular Mechanisms in Depression 1047 15. Subtypes of depression with response to treatment with trazodone or amitriptyline. J based on excretion of MHPG and response to nortriptyline. Relationships and beta-adrenergic receptor binding in the frontal cortices of between catecholamine and cortisol measures in depressed pa- suicide victims. Presented at the American College of Neuropsychophar- 38. Lack of behavioral ceruleus neurons in suicide victims: preliminary results. Biol effects of monoamine depletion in healthy subjects. Effects of alpha- of norepinephrine transporters in the locus ceruleus in major methyl-para tyrosine (AMPT) in drug-free depressed patients. Clinical and bio- of [3H]-adrenaline to platelets of depressed patients with melan- chemical effects of catecholamine depletion on antidepressant- cholia: effect of long-term clomipramine treatment. Arch Gen Psychiatry 1996; Psychiat Scand 1987;75(2):150–157. Arch Gen Psychiatry 1999; alpha-2 adrenoceptor density in major depression: effects of 56(5):395–403. Monoamine metabo- amine output and heterologous desensitization of platelet ade- lites in CSF and suicidal behavior. Platelet alpha adrener- nal fluid 5-hydroxyindoleacetic acid concentration differentiates gic binding and biochemical responsiveness in depressed pa- impulsive from nonimpulsive violent behavior. Aggression, suicidality and seroto- receptor-mediated inhibition of platelet adenylate cyclase and nin. Is platelet imipramine binding reduced in term antidepressant drug treatment. Differential inhibitory mine binding in the brains of patients with depressive illness. The growth hormone [123I]-2-beta-carbomethoxy-3-beta-(4-iodophenyl)tropane and response to clonidine in acute and remitted depressed male pa- single photon emission computed tomography. Increased serotonin1 (5-HT2) receptor rine systems in mood disorders. New York: in the blood platelets of depressed patients. Serotonin 5-HT2 receptor in the brain of suicide victims: increased receptor density associ- binding on blood platelets as a state dependant marker in major ated with major depression. Brain alpha- receptor binding sites in depression and suicide. Biol Psychiatry adrenoceptors in depressed suicides. Effects of selective 1048 Neuropsychopharmacology: The Fifth Generation of Progress serotonin reuptake inhibitors on platelet serotonin parameters 73. Serotonin transporter gene in major depressive disorders. Biol Psychiatry 1997;41(2): polymorphism and antidepressant response. Serotonin and the demonstration of increase serotonin 5-HT2 and beta-adrenergic neurobiology of depression. Effects of tryptophan depletion in receptor binding sites in the brain of suicide victims. Arch Gen Psychiatry 1994;51(11): Psychiatry 1990;47:1038–1047. Serotonin 5-HT2 receptor tomography measurement of cerebral metabolic correlates of imaging in major depression: Focal changes in orbito-insular tryptophan depletion-induced depressive relapse. Rapid serotonin deple- receptors in depression: An [18F] setoperone PET imaging tion as a provocative challenge test for patients with major study. Lack of relapse with receptors studied in depressive patients during chronic treat- tryptophan depletion following successful treatment with ACT. Decrease in brain seroto- cal consequences of rapid tryptophan depletion. Neuropsycho- nin 2 receptor binding in patients with major depression follow- pharmacology 2000;23:601–622. Protein kinase C in Proc Natl Acad Sci USA 1997;94:5308–5313. Hormonal responses to fenfluramine in pholipase C 1 protein in the prefrontal cortex of teenage sui- depressed and control subjects. Growth-associated protein fenfluramine in major depression: evidence of diminished re- (GAP43), its mRNA, and protein Kinase C (PKc) izoenzymes sponsivity of central serotonergic function. Am J Psychiatry in brain regions of depressed suicides. Altered brain protein depression is not associated with normalization of serotonergic kinase C in depression: a post-mortem study. Serotonergic measures in dopamine transmission among patients with depression who suicide brain: 5-HT1A binding sites in frontal cortex of suicide attempted suicide. Serotonin recep- creased in depression: CSF dopamine, noradrenaline and their tors in suicide victims with major depression. Neuropsychophar- metabolites in depressed patients and controls. Urinary monoamines and porter gene promoter polymorphism (5-HT TLPR) and pre- monoamine metabolites in subtypes of unipolar depressive dis- frontal cortical binding in major depression and suicide. Polymorphism within roid/dopamine hypothesis for psychotic depression and related the promoter of the serotonin transporter gene and antidepres- states. Psychotic and the promoter of the serotonin transporter gene. I: Comparison of plasma catechola- pharmacol 2000;20(1):105–107. Glucocorti- the serotonin transporter promoter affects onset of paroxetine coid effects on mesotelencephalic dopamine neurotransmission. Stress-level cortisol treat- Chapter 72: Molecular and Cellular Mechanisms in Depression 1049 ment impairs inhibitory control of behavior in monkeys. J Neu- major depression: increase during the depressive episode and rosci 2000;20:7816–7821. Benzodiazepine and GABA relationship to dexamethasone suppresion test results in patients receptors in rat brain following chronic antidepressant drug ad- with affective disorder. GABA levels in CSF hour monitoring of cortisol and corticotropin secretion in psy- of patients with psychiatric disorders. Am J Psychiatry 1980; chotic and nonpsychotic major depression. Plasma GABA in affective illness, a pre- ventricular nucleus of the hypothalamus in depression. Plasma levels aminobutyric acid levels in male patients with depression. Biol of arginine vasopressin elevated in patients with major depres- Psychiatry 1992;32:354–363. Effects of the high- plasma and CSF gamma-aminobutyric acid in affective illness: affinity corticotrophin-releasing hormone receptor 1 antagonist effect of lithium carbonate. R121919 in major depression: the first 20 patients treated. Amino acid levels in nomic responses to stress in women after sexual and physical depression: a preliminary investigation. Cortisol production tive CSF TRH in depressed patients. TRH in cerebrospinal fluid from patients with endogenous 105. Differences in CSF Gen Psychiatry 1985;42:1193–1204. The dexametha- patients and normal subjects: negative findings. Am J Psychiatry sone suppression test: Identification of subtypes of depression. DST studies in psychotic depression: a disorders: overview and future prospects. Exaggerated TSH of outcome in depression: a meta-analysis. Am J Psychiatry 1993; responses to TRH in depressed patients with 'normal' baseline.
Protein synthesis and degradation rates in acutely urem ic and sham -operated rats generic 120mg silvitra with visa. The hallm ark of m etabol- ic alterations in ARF is activation of protein catabolism with excessive release of am ino acids from skeletal m uscle and sus- tained negative nitrogen balance [7 120mg silvitra visa, 8] generic 120 mg silvitra with mastercard. N ot only is protein break- down accelerated, but there also is defective m uscle utilization of am ino acids for protein synthesis. In m uscle, the m axim al rate of insulin-stim ulated protein synthesis is depressed by ARF and pro- tein degradation is increased, even in the presence of insulin. A, Am ino acid transport into skele- This abnorm ality can be linked both to insulin resistance and to tal m uscle is im paired in ARF. Transm em branous uptake of a generalized defect in ion transport in urem ia; both the activity the am ino acid analogue m ethyl-am ino-isobutyrate (M AIB) is and receptor density of the sodium pum p are abnorm al in adi- reduced in urem ic tissue in response to insulin (m uscle tissue pose cells and m uscle tissue. B, The im pairm ent of rubidium from urem ic anim als, black circles, and from sham -operated ani- uptake (Rb) as a m easure of N a-K-ATPase activity is tightly cor- m als, open circles, respectively). Thus, insulin responsiveness is related to the reduction in am ino acid transport. Am ino acids are erated hepatic gluconeogenesis, which cannot be suppressed by redistributed from m uscle tissue to the liver. H epatic extraction of exogenous substrate infusions (see Fig. In the liver, protein am ino acids from the circulation— hepatic gluconeogenesis, A, and synthesis and secretion of acute phase proteins are also stim ulated. Circles— livers from acutely urem ic rats; squares— livers from sham The dom inant m ediator of protein catabolism in ARF is this accel- operated rats. Nutrition and M etabolism in Acute Renal Failure 18. In m uscle, the m axim al rate of insulin-stim ulated CATABOLISM IN ACUTE RENAL FAILURE protein synthesis is depressed by ARF and protein degradation is increased even in the presence of insulin. Acidosis was identified as an im portant factor in m uscle protein breakdown. M etabolic acidosis activates the catabolism of protein Impairment of metabolic functions by uremia toxins and oxidation of am ino acids independently of azotem ia, and Endocrine factors nitrogen balance can be im proved by correcting the m etabolic Insulin resistance acidosis. These findings were not uniform ly confirm ed for Increased secretion of catabolic hormones (catecholamines, ARF in anim al experim ents. The Hyperparathyroidism secretion of catabolic horm ones (catecholam ines, glucagon, Suppression of release or resistance to growth factors glucocorticoids), hyperparathyroidism which is also present in ARF Acidosis (see Fig. M oreover, the release of inflam m ato- Inadequate supply of nutritional substrates ry m ediators such as tum or necrosis factor and interleukins have Loss of nutritional substrates (renal replacement therapy) been shown to m ediate hypercatabolism in acute disease [1, 2]. The type and frequency of renal replacem ent therapy can also affect protein balance. Aggravation of protein catabolism , certainly, is m ediated in part by the loss of nutritional substrates, but som e FIGURE 18-8 findings suggest that, in addition, both activation of protein Protein catabolism in acute renal failure (ARF): contributing factors. In experim ental anim als, starvation potentiates and, finally, the type and intensity of renal replacement therapy. FIGURE 18-9 Am ino acid pools and am ino acid utilization in acute renal failure extraction of am ino acids observed in anim al experim ents, (ARF). As a consequence of these m etabolic alterations, im bal- overall am ino acid clearance and clearance of m ost glucoplastic ances in am ino acid pools in plasm a and in the intracellular com - am ino acids is enhanced. In contrast, clearances of PH E, proline partm ent occur in ARF. A typical plasm a am ino acid pattern is (PRO ), and, rem arkably, VAL are decreased [16, 17]. Plasm a concentrations of cysteine (CYS), taurine (TAU), alanine; ARG— arginine; ASN — asparagine; ASP— aspartate; m ethionine (M ET), and phenylalanine (PH E) are elevated, where- CIT— citrulline; GLN — glutam ine; GLU— glutam ate; GLY— as plasm a levels of valine (VAL) and leucine (LEU) are decreased. As expected from the stim ulation of hepatic (From Drum l et al. Thus, loss of renal function can contribute to the altered am ino acid pools in ARF and to the fact that several am ino acids, such as arginine or tyrosine, which conventionally are term ed nonessential, m ight becom e conditionally indispensable in ARF (see Fig. In addition, the kidney is an im portant organ of protein degrada- tion. M ultiple peptides are filtered and catabolized at the tubular brush border, with the constituent am ino acids being reabsorbed and recycled into the m etabolic pool. In renal failure, catabolism of peptides such as peptide horm ones is retarded. This is also true for acute urem ia: insulin requirem ents decrease in diabetic patients who develop of ARF. W ith the increased use of dipeptides in artificial nutrition as a source of am ino acids (such as tyrosine and glutam ine) which are not soluble or stable in aqueous solutions, this m etabolic function of the kidney m ay also gain im portance for utilization of these novel nutritional substrates. In the case of glycyl-tyrosine, m etabol- ic clearance progressively decreases with falling creatinine clearance FIGURE 18-10 (open circles, 7 healthy subjects and a patient with unilateral M etabolic functions of the kidney and protein and am ino acid nephrectom y*) but extrarenal clearance in the absence of renal m etabolism in acute renal failure (ARF). Protein and am ino acid function (black circles) is sufficient for rapid utilization of the m etabolism in ARF are also affected by im pairm ent of the m eta- dipeptide and release of tyrosine. Infusion of arginine-free am ino acid solutions can cause life-threatening com - plications such as hyperam m onem ia, com a, and acidosis. H ealthy subjects readily form tyrosine from phenylalanine in the liver: During infusion of am ino acid solutions containing phenylalanine, plasm a tyrosine concentration rises (circles). In contrast, in patients with ARF (triangles) and chronic renal failure (CRF, squares) phenylalanine infusion does not increase plasm a tyrosine, indicating inadequate interconversion. Recently, it was suggested that glutam ine, an am ino acid that traditionally was designated non-essential exerts im portant m eta- bolic functions in regulating nitrogen m etabolism , supporting im m une functions, and preserving the gastrointestinal barrier. Thus, it can becom e conditionally indispensable in catabolic ill- ness. Because free glutam ine is not stable in aqueous solu- tions, dipeptides containing glutam ine are used as a glutam ine source in parenteral nutrition. The utilization of dipeptides in FIGURE 18-11 part depends on intact renal function, and renal failure can im pair Am ino acids in nutrition of acute renal failure (ARF): Conditionally hydrolysis (see Fig. N o system atic studies have been essential am ino acids. Because of the altered m etabolic environm ent published on the use of glutam ine in patients with ARF, and it of urem ic patients certain am ino acids designated as nonessential m ust be noted that glutam ine supplem entation increases nitrogen for healthy subjects m ay becom e conditionally indispensable to ARF intake considerably. Nutrition and M etabolism in Acute Renal Failure 18. The extent of protein catabolism can be assessed by calculating the urea nitro- gen appearance rate (UN A), because virtually all nitrogen arising Urea nitrogen appearance (UNA) (g/d) from am ino acids liberated during protein degradation is converted Urinary urea nitrogen (UUN) excretion to urea. Besides urea in urine (UUN ), nitrogen losses in other body fluids (eg, gastrointestinal, choledochal) m ust be added to any Change in urea nitrogen pool change in the urea pool. W ith known nitrogen (BW 2 BW1) BUN2/100 intake from the parenteral or enteral nutrition, nitrogen balance If there are substantial gastrointestinal losses, add urea nitrogen in secretions: can be estim ated from the UN A calculation. In the polyuric recovery phase in patients with sepsis-induced ARF, a nitrogen intake of 15 g/day (averaging an amino acid intake of 1. Several recent studies have tried to evaluate protein and am ino acid requirem ents of critically ill patients with ARF. Kierdorf and associates found that, in these hypercatabolic patients receiving continuous hem ofiltration therapy, the provision of am ino acids 1. Am ino acid and protein requirem ents of patients with acute renal Chim a and coworkers m easured a m ean PCR of 1. The optim al intake of protein or am ino acids is weight per day in 19 critically ill ARF patients and concluded that affected m ore by the nature of the underlying cause of ARF and protein needs in these patients range between 1. Sim ilarly, M arcias and coworkers have obtained a protein than by kidney dysfunction per se. Unfortunately, only a few stud- catabolic rate (PCR) of 1. In nonhypercatabolic patients, during the polyuric phase of ARF Sim ilar conclusions were drawn by Ikitzler in evaluating ARF protein intake of 0. The factors contributing to insulin resistance are m ore m ajor cause of elevated blood glucose concentrations is insulin or less identical to those involved in the stim ulation of protein resistance. Results from experim ental anim als sug- insulin-stim ulated glucose uptake by skeletal m uscle is decreased by gest a com m on defect in protein and glucose m etabolism : tyrosine 50 % , A, and m uscular glycogen synthesis is im paired, B. H owever, release from m uscle (as a m easure of protein catabolism ) is closely insulin concentrations that cause half-m axim al stim ulation of glu- correlated with the ratio of lactate release to glucose uptake. A second feature of glucose metabolism (and at the same time the dominating mechanism of accelerated pro- tein breakdown) in ARF is accelerated hepatic gluconeogenesis, main- ly from conversion of amino acids released during protein catabolism. Hepatic extraction of amino acids, their conversion to glucose, and urea production are all increased in ARF (see Fig. In healthy subjects, but also in patients with chronic renal failure, hepatic gluconeogenesis from amino acids is readily and completely suppressed by exogenous glucose infusion. In contrast, in ARF hepat- ic glucose formation can only be decreased, but not halted, by sub- strate supply. As can be seen from this experimental study, even dur- ing glucose infusion there is persistent gluconeogenesis from amino acids in acutely uremic dogs (•) as compared with controls dogs (o) whose livers switch from glucose release to glucose uptake. These findings have important implications for nutrition support for patients with ARF: 1) It is impossible to achieve positive nitrogen balance; 2) Protein catabolism cannot be suppressed by providing conventional nutritional substrates alone. Thus, for future advances alternative means must be found to effectively suppress protein catab- olism and preserve lean body mass. Profound alterations of lipid metabolism occur in patients with ARF. The triglyceride con- tent of plasma lipoproteins, especially very low-density (VLDL) and low-density ones (LDL) is increased, while total cholesterol and in particular high-density lipoprotein (HDL) cholesterol are decreased [33,34]. The major cause of lipid abnormalities in ARF is impair- ment of lipolysis. The activities of both lipolytic systems, peripheral lipoprotein lipase and hepatic triglyceride lipase are decreased in patients with ARF to less than 50% of normal.
Certain kinds of stereotypies silvitra 120mg overnight delivery, such as be detected in the paternally derived chromosome 15 thumb sucking and head banging discount silvitra 120mg on line, appear more common (15q11q13) purchase 120 mg silvitra visa, whereas in about 20% of patients both copies in children, although on occasion these behaviors may also of chromosome 15 are inherited from the mother (maternal be seen in intellectually normal adults (2). Genotype-phenotype correlations in population, the total number of stereotypic behaviors was 167 patients with PWS found no significant difference in significantly associated with increased scores of obsessive- skin picking between patients with or without a chromo- compulsive symptoms, of perfectionism, and of impulsive- somal deletion (50). Nevertheless, the abnormal gene prod- aggressive traits (54). Importantly, stereotypic behaviors uct in PWS may ultimately provide crucial information on may be associated with significant medical complications, the neurochemistry of the SIB characteristic of these pa- and they may also lead to distressing feelings of shame and tients. Neuroanatomy Neurochemistry Most recently, volumetric magnetic resonance imaging (MRI) and positron-emission tomography (PET) tech- Case reports suggested that the SSRIs may have a role in niques have documented reduced caudate volume and re- the treatment of skin picking. Indeed, in a series of 30 1748 Neuropsychopharmacology: The Fifth Generation of Progress patients with skin picking, an open trial of sertraline demon- tism were found to have a different range of repetitive symp- strated efficacy (55). They were more likely to demonstrate repetitive or- view of body dysmorphic disorder patients with skin picking dering, hoarding, touching, tapping, or rubbing, and self- indicated that SSRIs were often effective, whereas other injurious behaviors (59). Nevertheless, it may be postulated agents were not (56). Finally, in their controlled study Si- that there are at least some similarities in the underlying meon and colleagues (53) found that fluoxetine was signifi- neurobiological mediation of autism and OCD. Neurochemistry In nail biting, clomipramine appeared more effective There does seem to be evidence of serotoninergic dysfunc- than desipramine, although results were not perhaps as ro- tion in autism (60). Several studies have found elevated bust as those seen in classic OCD (33). The authors empha- platelet serotonin levels in autism. Neuroendocrine chal- sized that there was a high dropout rate at every stage of lenge studies with serotoninergic agents have indicated re- the study, which appeared in sharp contrast to that seen in duced serotoninergic responsivity in autism. They did, however, suggest in a tryptophan depletion study, autism resulted in in- that their data were consistent with the hypothesis that simi- creased SIB, motor stereotypies, and anxiety. However, both open and placebo-controlled and desipramine in a crossover trial of SMD patients. Al- (61) trials with SSRIs have demonstrated efficacy in reduc- though clomipramine appeared promising in a number of ing symptoms such as SIB in autism. Furthermore, the SSRI cases, too few patients completed the trial to demonstrate clomipramine was more effective than the noradren- a clear benefit of clomipramine over desipramine. Neverthe- ergic reuptake inhibitor desipramine in autism (62). Never- less, several case reports suggest that SSRIs may be useful theless, not all studies of these agents have been positive in patients with skin picking, head banging, and other self- (63). Given that dopamine Other neurochemical systems may also play a role in the agonists may result in SIB (57), a possible role for dopamine mediation of self-injurious behaviors in autism. APET blockers, and the new atypical neuroleptics in particular, study demonstrated reduced dopaminergic activity in the also warrants further consideration. Ultimately, controlled anterior medial prefrontal cortex (64). Controlled trials have and long-term studies are needed to formulate rational ap- demonstrated that dopamine blockers (like SSRIs) are effec- proaches to the pharmacotherapy of SMD. Clinical experience indicates Neuroanatomy that where a medication is ineffective in autism, an agent To our knowledge, there have been no studies on the neu- from a different class of medication may be useful (60). The roanatomy of stereotypic movement disorder in normal atypical neuroleptics, with their combined dopaminergic controls. Given the ubiquity of these behaviors, and the and serotoninergic effects, also warrant further study. However, studies of opioid levels in tigating in more detail. Furthermore, despite prom- ising open trials, in controlled studies the effect of opioid blockers on target symptoms including SIB in autism has AUTISM been disappointing. Phenomenology There is promise for delineating the specific albeit multi- ple genetic factors underlying autism (60). Most recently, a possible link to the seroto- actions, communication deficits, and restrictive and stereo- nin-transporter gene has been suggested. Stereotyped SIBs are common in patients ultimately lead to a clearer understanding of the neurochem- with this disorder and may also be seen in other pervasive istry of autism and self-injury and to specific therapeutic developmental disorders that do not meet the narrower cri- interventions. Common forms of SIB in autism include hand/wrist biting, head banging, self- Neuroanatomy scratching, self-hitting, self-pinching, and hair pulling. It has been argued that repetitive behaviors in autism The neuroanatomy of autism has also received increasing cannot simply be subsumed under the banner of OCD. Preliminary postmortem Indeed, compared to patients with OCD, adults with au- studies have found abnormalities in the cerebellum and lim- Chapter 121: Compulsive and Impulsive Aspects of Self-Injurious Behavior 1749 bic system, including the hippocampus and amygdala. Neu- TRICHOTILLOMANIA rophysiologic research has demonstrated various abnormali- Phenomenology ties including aberrant processing in frontal association cortex. Early work with pneumoencephalography suggested The term trichotillomania was coined over a century ago left temporal horn dilatation, and an early MRI study found to describe patients with hair pulling. Hair pulling most hypoplasia of the posterior cerebellar vermis, but later stud- frequently occurs from the scalp, although it can occur from ies have been inconsistent. Functional brain imaging studies a wide range of body areas, including the eyebrows, eye- are also so far inconsistent, although perhaps suggestive of lashes, beard, axillae, and pubis (70). Plucking may be con- dysfunction in association cortex. Clearly, much remains to fined to a single patch, may involve different areas, or may be done to understand the neuroanatomy of SIB, and in- cover the entire scalp. Some patients also report pulling hair deed to integrate behavioral and biological findings in this from a child, significant other, or pet. Patients with hair pulling may demonstrate a range of other stereotypic and self-injurious behaviors (70,71). Indeed, both the personal and the economic costs of this disorder may Compulsive self-injurious behavior is only rarely seen in be significant. Awide range of behaviors may be seen, particularly head banging and self-punching or slapping, but also including lip biting and tongue biting, Neurochemistry eye poking, skin picking, and self-punching or -slapping. Research on the neurobiology of hair pulling was boosted Medical complications have included subdural hematoma by a seminal trial comparing clomipramine and desipramine and vision impairment. As in OCD, trichotillomania re- In a large study, SIB in TS was not correlated with intel- sponded selectively to the SSRI. Nevertheless, although the lectual function, but was significantly associated with sever- SSRIs have seemed effective for trichotillomania in a num- ity of motor tics and with scores of hostility and obsession- ber of open trials, these agents have proved disappointing ality (68). Furthermore, SIB has been described as one of in placebo-controlled trials (72). Thus, although the neurobiology of SIB trichotillomania response to clomipramine may be sustained per se in TS has not been well studied, it is possible that over time, there are also reports that initial response to SSRIs this overlaps with that underlying tics and compulsions. Taken together, this work indicates that it may be premature to overly emphasize the specific role of Neurochemistry serotonin in trichotillomania. Several neurochemical systems have been implicated in TS, Indeed, few studies of trichotillomania patients have di- most notably the dopamine system, but including also the rectly assessed monoamine concentrations. Ninan and col- serotoninergic, noradrenergic, opiatergic, hormonal, and leagues (73) obtained CSF from a small group of patients immunologic systems (see Chapter 117). However, to our with trichotillomania and found that CSF 5-HIAA levels knowledge little of this work has focused specifically on the did not differ from normal controls. This finding is redolent of some work on OCD and suggests that in both disorders response to SSRIs may Neuroanatomy be accompanied by a fall in CSF 5-HIAA levels. From a neuroanatomic perspective, there is strong evidence There are also few studies of serotoninergic pharmaco- that prefrontal–basal ganglia–thalamic circuits are involved logic challenges in trichotillomania. There is also increasing evidence that these circuits (74) found that the 5-HT agonist m-chlorophenylpipera- are among those that mediate TS (see Chapter 117). Of zine (mCPP), which has exacerbated OCD symptoms in note, increased metabolism in the orbitofrontal cortex and some studies, did not lead to an increase in hair pulling in putamen correlated with complex behavioral and cognitive women with trichotillomania (74). The interpretation of features such as self-injurious behavior (69). As in OCD, these data is not straightforward; for example, whereas further work is needed to determine whether this reflects a OCD symptoms may be present throughout the day, hair primary deficit or functional compensation. Of in- 1750 Neuropsychopharmacology: The Fifth Generation of Progress terest, however, trichotillomania subjects described an in- also been partly consistent with involvement of the CSTC crease in feeling 'high,' a phenomenon previously docu- system in trichotillomania (74). Furthermore, a few studies mented in patients with borderline personality disorder. It of brain imaging in trichotillomania have now been under- might be speculated that hair pulling in trichotillomania taken. There is some prelimi- umes in trichotillomania and controls on MRI, but did nary data that dopamine also plays a role in hair pulling. This finding is of particular interest given phenidate in a series of children (75). Asimilar phenome- work demonstrating reduced left putamen volumes in non can be seen in adults with trichotillomania. The atypical neuroleptics, illomania patients compared with normal controls. This which have dopamine and serotonin antagonist effects, may finding does not seem to support the hypothesis that orbito- also be effective augmenting agents in OCD and trichotillo- frontal–basal ganglia circuits are key to this disorder, and mania (78). Christenson and colleagues found no significant differ- However, patients were scanned at rest, rather than during ences in either pain detection or pain tolerance thresholds hair pulling or during the performance of a neuropsycho- between trichotillomania patients and controls. On the logical test that might have activated these structures. Swedo other hand, this group have suggested that the opioid and colleagues also found that anterior cingulate and or- blocker naltrexone may be effective in the treatment of tri- bital-frontal metabolism correlated negatively with clomi- chotillomania, indicating that further research on the opioid pramine response, a result they had previously found in system in hair pulling may be useful (74). They concluded that increased orbital-frontal metab- Trichotillomania is predominantly a disorder of women olism may comprise a compensatory response to basal gan- in the clinical setting. It frequently begins around the time glia pathology in both these disorders.