Glycogen synthase kinase 3 inhibition slows mitochondrial adenine nucleotide transport and regulates voltage-dependent anion channel phosphorylation

Inhibition of glycogen synthase kinase (GSK)-3 reduces ischemia/reperfusion injury by mechanisms that involve the mitochondria. The goal of this study was to explore possible molecular targets and mechanistic basis of this cardioprotective effect. In perfused rat hearts, treatment with GSK inhibitors before ischemia significantly improved recovery of function. To assess the effect of GSK inhibitors on mitochondrial function under ischemic conditions, mitochondria were isolated from rat hearts perfused with GSK inhibitors and were treated with uncoupler or cyanide or were made anoxic. GSK inhibition slowed ATP consumption under these conditions, which could be attributable to inhibition of ATP entry into the mitochondria through the voltage-dependent anion channel (VDAC) and/or adenine nucleotide transporter (ANT) or to inhibition of the F(1)F(0)-ATPase. To determine the site of the inhibitory effect on ATP consumption, we measured the conversion of ADP to AMP by adenylate kinase located in the intermembrane space. This assay requires adenine nucleotide transport across the outer but not the inner mitochondrial membrane, and we found that GSK inhibitors slow AMP production similar to their effect on ATP consumption. This suggests that GSK inhibitors are acting on outer mitochondrial membrane transport. In sonicated mitochondria, GSK inhibition had no effect on ATP consumption or AMP production. In intact mitochondria, cyclosporin A had no effect, indicating that ATP consumption is not caused by opening of the mitochondrial permeability transition pore. Because GSK is a kinase, we assessed whether protein phosphorylation might be involved. Therefore, we performed Western blot and 1D/2D gel phosphorylation site analysis using phos-tag staining to indicate proteins that had decreased phosphorylation in hearts treated with GSK inhibitors. Liquid chromatographic-mass spectrometric analysis revealed 1 of these proteins to be VDAC2. Taken together, we found that GSK-mediated signaling modulates transport through the outer membrane of the mitochondria. Both proteomics and adenine nucleotide transport data suggest that GSK regulates VDAC and that VDAC may be an important regulatory site in ischemia/reperfusion injury.     

Living donor intestinal transplant using a standardized technique: first report from India

Aim

We describe the first living donor intestinal transplant (LDIT) in India and discuss the indications and problems of this complex procedure.

Methods

A 43-year-old male patient required massive bowel resection for gangrene due to thrombosis of the superior mesenteric artery. He was maintained on parenteral nutrition but developed cholestasis and well as repeated catheter related infections with progressive loss of venous access due to thrombosis of central veins. A LDIT was performed using 200?cm of small intestine from the patient's son. The graft was based on the continuation of the superior mesenteric vessels beyond the ileocolic branch. The artery was anastomosed directly to the aorta and the vein to the venacava.

Results

The graft functioned well and he was weaned off parenteral nutrition. However, he later developed complications (wound dehiscence and enterocutaneous fistula) and developed sepsis. He succumbed to sepsis with a functioning graft 6?weeks after the transplant. The donor recovered uneventfully and was discharged on the 4th postoperative day.

Conclusions

LDIT can be life saving in patients with intestinal failure and failure of parenteral nutrition. There is a need to introduce this modality in India. In a setting of scarcity of deceased donor organs the living donor option has advantages.     

Behavioral training for pill-swallowing difficulties in young children with autistic disorder

INTRODUCTION: Difficulty with swallowing pills is a common problem, leading to noncompliance with treatment recommendations. Many young children with autistic disorder (AD) who also show comorbid symptoms associated with attention deficit hyperactivity disorder (ADHD) have difficulty swallowing pills. This pilot study describes our experience in teaching pill-swallowing skills to 4 children with AD who also had comorbid symptoms associated with ADHD. METHODS: Four children, aged 5-;6.5 years, were enrolled for pill-swallowing training, 3 of the children were Caucasian boys and 1 child was a Hispanic girl. All children met the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnostic criteria for AD and ADHD-like symptoms. The children's verbal IQ ranged from 54-96, their nonverbal IQ ranged from 85-107, and the Preschool Language Scale-3 total language score ranged from 50-98. RESULTS: At the end of the pilot study, 2 children (50%) successfully learned to swallow the study capsules, 1 child (25%) was able to swallow the study capsules with the behavior therapist but had difficulty with the caregiver, and 1 child (25%) made slow progress and was withdrawn by the caregiver in favor of proceeding with a crushable medication for clinical care. CONCLUSION: Caregivers were appreciative of the opportunity for this short intervention. Behavioral training for pill swallowing may be indicated in some circumstances in young children with AD and/or other developmental disorders.     

Methylphenidate effects on functional outcomes in the Preschoolers with Attention-Deficit/Hyperactivity Disorder Treatment Study (PATS)

OBJECTIVE: The purpose of this study was to examine the effects of methylphenidate (MPH) on functional outcomes, including children's social skills, classroom behavior, emotional status, and parenting stress, during the 4-week, double-blind placebo controlled phase of the Preschoolers with Attention Deficit/Hyperactivity Disorder (ADHD) Treatment Study (PATS). METHODS: A total of 114 preschoolers who had improved with acute MPH treatment, were randomized to their best MPH dose (M = 14.22 mg/day; n = 63) or placebo (PL; n = 51). Assessments included the Clinical Global Impression-Severity (CGI-S), parent and teacher versions of the Strengths and Weaknesses of ADHD-Symptoms and Normal Behaviors (SWAN), Social Competence Scale (SCS), Social Skills Rating System (SSRS), and Early Childhood Inventory (ECI), and Parenting Stress Index (PSI). RESULTS: Medication effects varied by informant and outcome measure. Parent measures and teacher SWAN scores did not differentially improve with MPH. Parent-rated depression (p < 0.02) and dysthymia (p < 0.001) on the ECI worsened with MPH, but scores were not in the clinical range. Significant medication effects were found on clinician CGI-S (p < 0.0001) and teacher social competence ratings (SCS, p < 0.03). CONCLUSIONS: Preschoolers with ADHD treated with MPH for 4 weeks improve in some aspects of functioning. Additional improvements might require longer treatment, higher doses, and/or intensive behavioral treatment in combination with medication.     

Parent versus teacher ratings of attention-deficit/hyperactivity disorder symptoms in the Preschoolers with Attention-Deficit/Hyperactivity Disorder Treatment Study (PATS)

OBJECTIVE: To assess parent-teacher concordance on ratings of DSM-IV symptoms of attention-deficit/hyperactivity disorder (ADHD) in a sample of preschool children referred for an ADHD treatment study. METHODS: Parent and teacher symptom ratings were compared for 452 children aged 3-5 years. Agreement was calculated using Pearson correlations, Cohen's kappa, and conditional probabilities. RESULTS: The correlations between parent and teacher ratings were low for both Inattentive (r = .24) and Hyperactive-Impulsive (r = .26) symptom domains, with individual symptoms ranging from .01-.28. Kappa values for specific symptoms were even lower. Conditional probabilities suggest that teachers are only moderately likely to agree with parents on the presence or absence of symptoms. Parents were quite likely to agree with teachers' endorsement of symptoms, but much less likely to agree when teachers indicated that a symptom was not present. CONCLUSIONS: Results provide important data regarding base rates and concordance rates in this age group and support the hypothesis that preschool-aged children at risk for ADHD exhibit significant differences in behavior patterns across settings. Obtaining ratings from multiple informants is therefore considered critical for obtaining a full picture of young children's functioning.     

Adverse Childhood Experiences and Complex Post-traumatic Stress in Pregnant Teens: A Pilot Study

Maternal and Child Health Journal - Pregnant teens are seen as a group at risk, yet one area that remains understudied is the impact of trauma on their mental health, maternal fetal attachment and...     

N-methyl-d-aspartate receptor- and metabotropic glutamate receptor-dependent long-term depression are differentially regulated by the ubiquitin-proteasome system

Long-term depression (LTD) in CA1 pyramidal neurons can be induced by activation of either N -methyl- d -aspartate receptors (NMDARs) or metabotropic glutamate receptors (mGluRs), both of which elicit changes in synaptic efficacy through α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor (AMPAR) endocytosis. To address the role of the ubiquitin-proteasome system in regulating AMPAR endocytosis during these forms of LTD, we examined the effects of pharmacological inhibitors of proteasomal degradation and protein ubiquitination on endocytosis of glutamate receptor 1 (GluR1) -containing AMPARs in dissociated rat hippocampal cultures as well as LTD of excitatory synaptic responses in acute rat hippocampal slices. Our findings suggest that the contribution of the ubiquitin-proteasome system to NMDAR-induced vs. mGluR-induced AMPAR endocytosis and the consequent LTD differs significantly. NMDAR-induced AMPAR endocytosis and LTD occur independently of proteasome function but appear to depend, at least in part, on ubiquitination. In contrast, mGluR-induced AMPAR endocytosis and LTD are enhanced by inhibition of proteasomal degradation, as well as by the inhibitor of protein ubiquitination. Furthermore, the decay of mGluR-induced membrane depolarization and Erk activation is delayed following inhibition of either ubiquitination or proteasomal degradation. These results suggest that, although NMDAR-dependent LTD may utilize ubiquitin as a signal for AMPAR endocytosis, mGluR-induced signaling and LTD are limited by a feedback mechanism that involves the ubiquitin-proteasome system.