Zenaide M. N. Quezado

A Randomized Add-on Trial of an N-methyl-d-aspartate Antagonist in Treatment-Resistant Bipolar Depression

CONTEXT Existing therapies for bipolar depression have a considerable lag of onset of action. Pharmacological strategies that produce rapid antidepressant effects-for instance, within a few hours or days-would have an enormous impact on patient care and public health. OBJECTIVE To determine whether an N-methyl-D-aspartate-receptor antagonist produces rapid antidepressant effects in subjects with bipolar depression. DESIGN A randomized, placebo-controlled, double-blind, crossover, add-on study conducted from October 2006 to June 2009. SETTING Mood Disorders Research Unit at the National Institute of Mental Health, Bethesda, Maryland. Patients Eighteen subjects with DSM-IV bipolar depression (treatment-resistant). INTERVENTIONS Subjects maintained at therapeutic levels of lithium or valproate received an intravenous infusion of either ketamine hydrochloride (0.5 mg/kg) or placebo on 2 test days 2 weeks apart. The Montgomery-Asberg Depression Rating Scale was used to rate subjects at baseline and at 40, 80, 110, and 230 minutes and on days 1, 2, 3, 7, 10, and 14 postinfusion. MAIN OUTCOME MEASURES Change in Montgomery-Asberg Depression Rating Scale primary efficacy measure scores. RESULTS Within 40 minutes, depressive symptoms significantly improved in subjects receiving ketamine compared with placebo (d = 0.52, 95% confidence interval [CI], 0.28-0.76); this improvement remained significant through day 3. The drug difference effect size was largest at day 2 (d = 0.80, 95% CI, 0.55-1.04). Seventy-one percent of subjects responded to ketamine and 6% responded to placebo at some point during the trial. One subject receiving ketamine and 1 receiving placebo developed manic symptoms. Ketamine was generally well tolerated; the most common adverse effect was dissociative symptoms, only at the 40-minute point. CONCLUSION In patients with treatment-resistant bipolar depression, robust and rapid antidepressant effects resulted from a single intravenous dose of an N-methyl-D-aspartate antagonist.

Real-time image-guided direct convective perfusion of intrinsic brainstem lesions: Technical note

Recent preclinical studies have demonstrated that convection-enhanced delivery (CED) can be used to perfuse the brain and brainstem with therapeutic agents while simultaneously tracking their distribution using coinfusion of a surrogate magnetic resonance (MR) imaging tracer. The authors describe a technique for the successful clinical application of this drug delivery and monitoring paradigm to the brainstem. Two patients with progressive intrinsic brainstem lesions (one with Type 2 Gaucher disease and one with a diffuse pontine glioma) were treated with CED of putative therapeutic agents mixed with Gd-diethylenetriamene pentaacetic acid (DTPA). Both patients underwent frameless stereotactic placement of MR imaging-compatible outer guide-inner infusion cannulae. Using intraoperative MR imaging, accurate cannula placement was confirmed and real-time imaging during infusion clearly demonstrated progressive filling of the targeted region with the drug and Gd-DTPA infusate. Neither patient had clinical or imaging evidence of short- or long-term infusate-related toxicity. Using this technique, CED can be used to safely perfuse targeted regions of diseased brainstem with therapeutic agents. Coinfused imaging surrogate tracers can be used to monitor and control the distribution of therapeutic agents in vivo. Patients with a variety of intrinsic brainstem and other central nervous system disorders may benefit from a similar treatment paradigm.

Correlation of Kidney Function, Volume and Imaging Findings, and PKHD1 Mutations in 73 Patients with Autosomal Recessive Polycystic Kidney Disease

BACKGROUND AND OBJECTIVES Renal function and imaging findings have not been comprehensively and prospectively characterized in a broad age range of patients with molecularly confirmed autosomal recessive polycystic kidney disease (ARPKD). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Ninety potential ARPKD patients were examined at the National Institutes of Health Clinical Center. Seventy-three fulfilled clinical diagnostic criteria, had at least one PKHD1 mutation, and were prospectively evaluated using magnetic resonance imaging (MRI), high-resolution ultrasonography (HR-USG), and measures of glomerular and tubular function. RESULTS Among 31 perinatally symptomatic patients, 25% required renal replacement therapy by age 11 years; among 42 patients who became symptomatic beyond 1 month (nonperinatal), 25% required kidney transplantation by age 32 years. Creatinine clearance (CrCl) for nonperinatal patients (103 +/- 54 ml/min/1.73 m(2)) was greater than for perinatal patients (62 +/- 33) (P = 0.002). Corticomedullary involvement on HR-USG was associated with a significantly worse mean CrCl (61 +/- 32) in comparison with medullary involvement only (131 +/- 46) (P < 0.0001). Among children with enlarged kidneys, volume correlated inversely with function, although with wide variability. Severity of PKHD1 mutations did not determine kidney size or function. In 35% of patients with medullary-only abnormalities, standard ultrasound was normal and the pathology was detectable with HR-USG. CONCLUSIONS In ARPKD, perinatal presentation and corticomedullary involvement are associated with faster progression of kidney disease. Mild ARPKD is best detected by HR-USG. Considerable variability occurs that is not explained by the type of PKHD1 mutation.

New strategies for combatting sepsis: the magic bullets missed the mark…but the search continues

Despite the high expectations of scientists and industry, multiple clinical trials of anti-endotoxin- and anti-cytokine-based therapies for sepsis have failed to demonstrate benefit. Indeed, in some cases, the agents used were actually harmful to patients. In retrospect, perhaps the therapeutic premises on which these therapies were based were flawed. In the future, a better understanding of sepsis should lead to the development of accurate laboratory and clinical predictors that will identify when, and which, patients can benefit from a given therapy. Much has been learned from the efforts of industry and academia and, hopefully, the search for new therapies for this lethal syndrome will continue.

Potential Outcome Factors in Subacute Combined Degeneration: Review of Observational Studies

BACKGROUND: Subacute combined degeneration is an acquired myelopathy caused by vitamin B12 deficiency. Therapy with B12 leads to improvement in most but to complete recovery in only a few patients. Prognostic indicators in subacute combined degeneration are unknown; therefore, predicting complete recovery of neurologic deficits is challenging.PURPOSE: To identify potential correlates of outcome and to generate hypotheses concerning predictors of complete resolution of neurologic deficits in subacute combined degeneration.DATA SOURCE: We searched EMBASE (1974 to October 2005), MEDLINE (1968 to October 2005), and references from identified reports.REPORTS SELECTION: Reports of patients with subacute combined degeneration containing results of magnetic resonance imaging (MRI) and description of outcome and 1 patient treated by the authors.DATA EXTRACTION, SYNTHESIS: We extracted data from 45 reports and 57 patients (36 males, 21 females: age range: 10 to 81) with a diagnosis of subacute combined degeneration, and estimated the strength of association between clinical, laboratory, and radiological factors and complete resolution of signs and symptoms.RESULTS: Eight patients (14%) achieved clinical resolution and 49 (86%) improved with B12 therapy. The absence of sensory dermatomal deficit, Romberg, and Babinski signs were associated with a higher complete resolution rate. Patients with MRI lesions in ≤7 segments and age less than 50 also appear to have higher rates of complete resolution.CONCLUSIONS: B12 therapy is reported to stop progression and improve neurologic deficits in most patients with subacute combined degeneration. However, complete resolution only occurs in a small percentage of patients and appears to be associated with factors suggestive of less severe disease at the time of diagnosis.

Systemic hemodynamic abnormalities and vasopressor therapy in sepsis and septic shock.

Septic shock, a distributive form of shock, is a common and lethal disease characterized by tachycardia, hypotension, normal or elevated cardiac index, and decreased systemic vascular resistance (SVR). For 2 to 4 days after onset of shock, the left ventricular ejection fraction (LVEF) is depressed; with adequate volume replacement, the left ventricle dilates and cardiac output (CO) is maintained or increased. In survivors, these abnormalities reverse to normal within 7 to 10 days. The myocardial depression found in patients with septic shock is not associated with global myocardial ischemia. In our animal model of sepsis, myocardial depression is not associated with impaired myocardial high-energy stores, or abnormal myocardial oxygen utilization. However, septic animals have histopathologic evidence of coronary nonocclusive microvascular damage and myocyte injury. The majority of human deaths caused by septic shock are related to the peripheral vascular dysfunction and multiorgan system failure that occurs over time. The pathophysiology of this disease is complex. Clinical and experimental evidence support the notion that myocardial depression, peripheral vascular abnormalities, and multiorgan dysfunction result from the combined effect of exogenous and endogenous mediators (eg, endotoxin, cytokines, and nitric oxide) released during septic shock. Although conventional therapy with fluids, vasopressors, and antibiotics is effective, the disease still has a high mortality rate. Studies investigating the effects of bacterial toxins and potentially harmful host mediators offer the greatest hope in finding new ways to eradicate this highly lethal disease.

Disruption of adaptive energy metabolism and elevated ribosomal p-S6K1 levels contribute to INCL pathogenesis: partial rescue by resveratrol

The infantile neuronal ceroid lipofuscinosis (INCL) is a devastating neurodegenerative lysosomal storage disease. Despite our knowledge that palmitoyl-protein thioesterase-1 (PPT1)-deficiency causes INCL, the molecular mechanism(s) of neurodegeneration and the drastically reduced lifespan of these patients remain poorly understood. Consequently, an effective treatment for this disease is currently unavailable. We previously reported that oxidative stress-mediated abnormality in mitochondria activates caspases-9 pathway of apoptosis in INCL fibroblasts and in neurons of Ppt1-knockout (Ppt1-KO) mice, which mimic INCL. Since mitochondria play critical roles in maintaining cellular energy homeostasis, we hypothesized that oxidative stress-mediated disruption of energy metabolism and homeostasis may contribute to INCL pathogenesis. We report here that, in cultured INCL fibroblasts and in the brain tissues of Ppt1-KO mice, the NAD(+)/NADH ratio, the levels of phosphorylated-AMPK (p-AMPK), peroxisome proliferator-activated receptor-γ (PPARγ) coactivator-1α (PGC-1α) and Silent Information Regulator T1 (SIRT1) are markedly down-regulated. This suggested an abnormality in AMPK/SIRT1/PGC-1α signaling pathway of energy metabolism. Moreover, we found that, in INCL fibroblasts and in the Ppt1-KO mice, phosphorylated-S6K-1 (p-S6K1) levels, which inversely correlate with lifespan, are markedly elevated. Most importantly, resveratrol (RSV), an antioxidant polyphenol, elevated the NAD(+)/NADH ratio, levels of ATP, p-AMPK, PGC-1α and SIRT1 while decreasing the level of p-S6K1 in both INCL fibroblasts and in Ppt1-KO mice, which showed a modest increase in lifespan. Our results show that disruption of adaptive energy metabolism and increased levels of p-S6K1 are contributing factors in INCL pathogenesis and provide the proof of principle that small molecules such as RSV, which alleviate these abnormalities, may have therapeutic potential.

Risks of Propofol Sedation/Anesthesia for Imaging Studies in Pediatric Research: Eight Years of Experience in a Clinical Research Center

OBJECTIVES To quantify the incidence of adverse events associated with anesthesia given for research-driven imaging studies and to identify risk factors for those events in pediatric research subjects. DESIGN Retrospective cohort study. SETTING National Institutes of Health Clinical Center. PARTICIPANTS Children and adolescents enrolled in clinical research protocols who required anesthesia for research-related imaging studies from January 2000 to September 2008. INTERVENTION Propofol sedation/anesthesia. MAIN OUTCOME MEASURE The occurrence of respiratory, cardiovascular, and all anesthesia-related adverse events that required intervention while receiving anesthetics for research-driven imaging studies and other noninvasive procedures. RESULTS We identified 607 children who received 1480 propofol anesthetic procedures for imaging studies. Seventy percent of anesthetics were given to subjects with severe diseases and significant disabilities (American Society of Anesthesiologists Physical Status [ASA] III). Anesthesia had a mean (SD) duration of 115 (55) minutes, and in 12.5% of procedures, an airway device was necessary. There were 98 notable respiratory, cardiovascular, and other events in 79 anesthetic procedures, a rate of 534 per 10 000 anesthetic procedures with 1 or more adverse events. There was no long-lasting morbidity or mortality. The ASA classification (odds ratio [OR], 2.92; 95% confidence interval [CI], 1.24-6.88), anesthetic effect duration (OR, 1.46; 95% CI, 1.25-1.70), and presence of airway abnormalities (OR, 4.41; 95% CI, 1.60-12.12) were independently associated with adverse events during anesthetic use. CONCLUSION In our clinical research sample of high-risk children who received sedation/anesthesia by an anesthesiologist, we observed a low incidence of adverse events and no long-term complications. Risk factors for adverse events included higher ASA classification, increasing anesthetic duration, and presence of airway abnormalities.

Altered Cerebral Protein Synthesis in Fragile X Syndrome: Studies in Human Subjects and Knockout Mice

Dysregulated protein synthesis is thought to be a core phenotype of fragile X syndrome (FXS). In a mouse model (Fmr1 knockout (KO)) of FXS, rates of cerebral protein synthesis (rCPS) are increased in selective brain regions. We hypothesized that rCPS are also increased in FXS subjects. We measured rCPS with the L-[1-11C]leucine positron emission tomography (PET) method in whole brain and 10 regions in 15 FXS subjects who, because of their impairments, were studied under deep sedation with propofol. We compared results with those of 12 age-matched controls studied both awake and sedated. In controls, we found no differences in rCPS between awake and propofol sedation. Contrary to our hypothesis, FXS subjects under propofol sedation had reduced rCPS in whole brain, cerebellum, and cortex compared with sedated controls. To investigate whether propofol could have a disparate effect in FXS subjects masking usually elevated rCPS, we measured rCPS in C57Bl/6 wild-type (WT) and KO mice awake or under propofol sedation. Propofol decreased rCPS substantially in most regions examined in KO mice, but in WT mice caused few discrete changes. Propofol acts by decreasing neuronal activity either directly or by increasing inhibitory synaptic activity. Our results suggest that changes in synaptic signaling can correct increased rCPS in FXS.

Neuronal nitric oxide synthase deficiency decreases survival in bacterial peritonitis and sepsis

ObjectiveTo investigate the role of neuronal nitric oxide synthase (NOS1) in murine polymicrobial peritonitis and sepsis.DesignRandomized experimental trial.SettingAnimal research facility.SubjectsB6129S NOS1+/+ and B6;129S4 NOS−/− mice.InterventionsNOS1+/+ and NOS1−/− animals underwent cecal ligation and puncture (CLP) or sham surgery and received the NOS1 inhibitor 7-nitroindazole (7-NI) or vehicle.Measurements and main resultsAfter CLP, genetic deficiency and pharmacologic inhibition of NOS1 significantly increased risk of mortality [8.69 (3.27, 23.1), p < 0.0001 and 1.71 (1.00, 2.92) p = 0.05, hazard ratio of death (95% confidence interval) for NOS1−/− and 7-NI-treated NOS1+/+ respectively] compared with NOS1+/+ animals. In 7-NI-treated NOS1+/+ animals, there were increases (6 h) and then decreases (24 h), whereas in NOS−/− animals persistent increases in blood bacteria counts ( p = 0.04 for differing effects of 7-NI and NOS1−/−) were seen compared with NOS1+/+ animals. After CLP, NOS1−/− had upregulation of inducible NOS and proinflammatory cytokines and greater increases in serum tumor necrosis factor-α and interleukin-6 levels compared with NOS1+/+ mice (all p < 0.05). Following CLP, there were similar significant decreases in circulating leukocytes and lung lavage cells ( p ≤ 0.0008) and significant increases in peritoneal lavage cells ( p = 0.0045) in all groups. Over 6 h and 24 h following CLP, compared with NOS1+/+, NOS−/− mice had significantly higher peritoneal cell concentrations {respectively 0.40 ± 0.09 vs 0.79 ± 0.15 [log(× 104cells/ml)] averaged over both times p = 0.038}.ConclusionsDeficiency and inhibition of NOS1 increases mortality, possibly by increasing proinflammatory cytokine response and impairing bacterial clearance after CLP. These data suggest that NOS1 is important for survival, bacterial clearance, and regulation of cytokine response during infection and sepsis.