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To clarify the physiological role of Na(+)-D-glucose cotransporter SGLT1 in small intestine and kidney, Sglt1(-/-) mice were generated and characterized phenotypically. After gavage of d-glucose, small intestinal glucose absorption across the brush-border membrane (BBM) via SGLT1 and GLUT2 were analyzed. Glucose-induced secretion of insulinotropic hormone (GIP) and glucagon-like peptide 1 (GLP-1) in wild-type and Sglt1(-/-) mice were compared. The impact of SGLT1 on renal glucose handling was investigated by micropuncture studies. It was observed that Sglt1(-/-) mice developed a glucose-galactose malabsorption syndrome but thrive normally when fed a glucose-galactose-free diet. In wild-type mice, passage of D-glucose across the intestinal BBM was predominantly mediated by SGLT1, independent the glucose load. High glucose concentrations increased the amounts of SGLT1 and GLUT2 in the BBM, and SGLT1 was required for upregulation of GLUT2. SGLT1 was located in luminal membranes of cells immunopositive for GIP and GLP-1, and Sglt1(-/-) mice exhibited reduced glucose-triggered GIP and GLP-1 levels. In the kidney, SGLT1 reabsorbed ∼3% of the filtered glucose under normoglycemic conditions. The data indicate that SGLT1 is 1) pivotal for intestinal mass absorption of d-glucose, 2) triggers the glucose-induced secretion of GIP and GLP-1, and 3) triggers the upregulation of GLUT2. [ABSTRACT FROM AUTHOR]

The purpose of the study was to estimate the burden to families of raising a child with attention-deficit/hyperactivity disorder (ADHD). Data were drawn from a longitudinal sample recruited in western Pennsylvania. When participants were between 14 and 17 years old, parents completed a questionnaire assessing economic burden over the course of raising their children. Domains of economic burden to families included direct costs related to child's behaviors (excluding treatment expenses) and indirect costs related to caregiver strain. On average, participants with ADHD incurred a total economic burden over the course of child development that was more than five times greater compared to youths without ADHD (ADHD = $15,036 per child, Control = $2,848 per child), and this difference remained significant after controlling for intellectual functioning, oppositional defiant symptoms, or conduct problems. Parents of participants with ADHD were more likely to have changed their job responsibilities or been fired and reported lower work efficiency. The current evaluation of economic burden to individual families extends previous estimates of annual societal cost of illness (COI) of ADHD. Our rough annual estimate of COI for ADHD in children and adolescents is $124.5 billion (2017 US Dollars). Findings underscore the need for interventions to reduce the costly dysfunctional outcomes in families of children with ADHD.

Objectives: We examined the association of parent training (PT)-related factors with therapeutic success in the Treatment of Severe Childhood Aggression (TOSCA) study. Our aims were (1) to evaluate demographic and clinical characteristics as predictors of parent attendance and engagement in PT and (2) to examine the associations of parent attendance and engagement in PT with study-targeted child behavior outcomes (i.e., attention-deficit/hyperactivity disorder [ADHD] and disruptive behavior symptoms). TOSCA was a randomized clinical trial evaluating the effect of placebo versus risperidone when added to PT and psychostimulant for childhood ADHD with severe aggression., Methods: Data for 167 parents and children 6-12 years old with ADHD, oppositional defiant disorder (ODD) or conduct disorder, and severe physical aggression were examined. Analyses used generalized linear models., Results: Most parents (72%) attended seven or more of nine sessions. The average parental engagement, that is, the percentage of PT elements fully achieved across participants and sessions, was 85%. The average therapist rating of goal completion was 92%. Parents of non-white and/or Hispanic children (p = 0.01) and children with lower intelligence quotient (p = 0.02) had lower PT attendance; parents with lower family incomes (p = 0.01) were less engaged. Attendance and engagement predicted better scores on the primary child behavior outcomes of disruptive behavior (Nisonger Child Behavior Rating Form Disruptive Behavior Total) and ADHD and ODD symptoms, adjusting for baseline severity., Conclusions: When the clinical picture is sufficiently severe to warrant prescribing an atypical antipsychotic, PT is feasible for families of children with ADHD and co-occurring severe aggression. The promotion of attendance and engagement in PT is important to enhance clinical outcomes among this challenging population. Methods for overcoming barriers to participation in PT deserve vigorous investigation, particularly for those with low family income, non-white race, Hispanic ethnicity, or when children have lower cognitive level.

Objective: Professionals have periodically expressed concern that atypical antipsychotics may cause cognitive blunting in treated patients. In this study, we report data from a double-blind, randomized, controlled study of stimulant plus placebo versus combined stimulant and risperidone to evaluate the effects of the atypical antipsychotic on attention and short-term memory., Methods: A total of 165 (n = 83 combined treatment; n = 82 stimulant plus placebo) children with attention-deficit/hyperactivity disorder and severe physical aggression, aged 6-12 years, were evaluated with Conners' Continuous Performance Test (CPT-II) and the Wechsler Intelligence Scale for Children-III (WISC) Digit Span subscale at baseline, after 3 weeks of stimulant-only treatment, and after six additional weeks of randomized treatment (stimulant+placebo vs. stimulant+risperidone)., Results: At 3 weeks, improvement on CPT-II performance (Commissions and Reaction Time Standard Error; p < 0.001) and on Digit Span memory performance (p < 0.006) was noted for the full sample. At study week 9, no difference in CPT-II or Digit Span performance was observed between the randomized groups (ps = 0.41 to 0.83)., Conclusions: Similar to other studies, we found no deleterious effects on attention and short-term memory associated with short-term use of risperidone. NCT00796302.

Objectives: Previous "Treatment of Severe Childhood Aggression" (TOSCA) reports demonstrated that many children with severe physical aggression and attention-deficit/hyperactivity disorder (ADHD) responded well to two randomized treatments (parent training [PT]+stimulant+placebo = Basic vs. PT+stimulant+risperidone = Augmented) for 9 weeks. An important clinical question is whether these favorable outcomes are maintained over longer times., Methods: Clinical responders to the 9-week trial (n = 103/168), defined as Clinical Global Impressions (CGI)-Improvement of much/very much improved plus substantial reduction in parent ratings of disruptiveness, were followed another 12 weeks (21 weeks total) while remaining on blinded treatment. Outcome measures included Clinical Global Impressions scale, Nisonger Child Behavior Rating Form (NCBRF), other parent/teacher-rated scales, laboratory tests, clinician ratings of abnormal movement, and other adverse events (AEs)., Results: Parent ratings of problem behavior showed minimal worsening of behavior from end of the 9-week acute trial (expected from regression to the mean after selecting best responders), but outcomes at Extension endpoint were meaningfully improved compared with acute study baseline. As expected, outcomes for Basic and Augmented treatment did not differ among these children selected for good clinical response. During Extension, more Augmented subjects had elevated prolactin; there were no clinically confirmed cases of tardive dyskinesia. Delayed sleep onset was the most frequent Basic AE. We also conducted a last-observation-carried-forward analysis, which included both nonresponders and responders. We found that, at the end of Extension, Augmented subjects had more improvement than Basic subjects on the NCBRF Positive Social subscale (p = 0.005; d = 0.44), the Antisocial Behavior Scale Reactive Aggression subscale (p = 0.03; d = 0.36), and marginally so on the Disruptive Behavior Total subscale (p = 0.058; d = 0.29, the primary outcome)., Conclusions: The medium-term outcomes were good for the participants in both treatment groups, perhaps because they were selected for good response. When nonresponders were included in ITT analyses, there was some indication that Augmented surpassed Basic treatment.

Cellular uptake adapts rapidly to physiologic demands by changing transporter abundance in the plasma membrane. The human gene RSC1A1 codes for a 67-kDa protein named RS1 that has been shown to induce downregulation of the sodium-D-glucose cotransporter 1 (SGLT1) and of the concentrative nucleoside transporter 1 (CNT1) in the plasma membrane by blocking exocytosis at the Golgi. Injecting RS1 fragments into Xenopus laevis oocytes expressing SGLT1 or CNT1 and measuring the expressed uptake of α-methylglucoside or uridine 1 hour later, we identified a RS1 domain (RS1-Reg) containing multiple predicted phosphorylation sites that is responsible for this post-translational downregulation of SGLT1 and CNT1. Dependent on phosphorylation, RS1-Reg blocks the release of SGLT1-containing vesicles from the Golgi in a glucose-dependent manner or glucose-independent release of CNT1-containing vesicles. We showed that upregulation of SGLT1 in the small intestine after glucose ingestion is promoted by glucose-dependent disinhibition of the RS1-Reg-blocked exocytotic pathway of SGLT1 between meals. Mimicking phosphorylation of RS1-Reg, we obtained a RS1-Reg variant that downregulates SGLT1 in the brush-border membrane at high luminal glucose concentration. Because RS1 mediates short-term regulation of various transporters, we propose that the RS1-Reg-navigated transporter release from Golgi represents a basic regulatory mechanism of general importance, which implies the existence of receptor proteins that recognize different phosphorylated forms of RS1-Reg and of complex transporter-specific sorting in the trans-Golgi. RS1-Reg-derived peptides that downregulate SGLT1 at high intracellular glucose concentrations may be used for downregulation of glucose absorption in small intestine, which has been proposed as strategy for treatment of type 2 diabetes., (Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.)

Objective: The purpose of this study was to examine the satisfaction of families who participated in the Treatment of Severe Childhood Aggression (TOSCA) study., Methods: TOSCA was a randomized clinical trial of psychostimulant plus parent training plus placebo (basic treatment) versus psychostimulant plus parent training plus risperidone (augmented treatment) for children with severe physical aggression, disruptive behavior disorder, and attention-deficit/hyperactivity disorder. Parents completed a standardized Parent Satisfaction Questionnaire (PSQ)., Results: Of the 168 families randomized, 150 (89.3%) provided consumer satisfaction data. When they were asked if they would join the study again if they had the option to repeat, 136 (91%) said "yes," 11 (7%) said "maybe," and one (<1%) said "no." When asked if they would recommend the study to other parents with children having similar problems, 147 (98%) said "yes" and 3 (2%) said "maybe." Between 71% (rating one aspect of the Parent Training) and 96% (regarding the diagnostic interview) endorsed study procedures using the most positive response option. Asked if there were certain aspects of the study that they especially liked, 64 (43%) spontaneously reported parent training. Treatment assignment (basic vs. augmented) and responder status were not associated with reported satisfaction. However, responder status was strongly associated with parent confidence in managing present (p<0.001) and future (p<0.005) problem behaviors., Conclusions: These findings indicate high levels of satisfaction with TOSCA study involvement and, taken together with previous pediatric psychopharmacology social validity studies, suggest high levels of support for the research experience. These findings may inform research bioethics and may have implications for deliberations of institutional review boards., Trial Registry: Treatment of Severe Childhood Aggression (The TOSCA Study), NCT00796302, clinicaltrials.gov .

Adolescents with attention deficit/hyperactivity disorder (ADHD) are at an increased risk for substance use but the pathways through which this risk emerges are insufficiently understood. Tobacco, alcohol, and marijuana outcomes were compared between adolescents diagnosed with ADHD in early childhood (N = 113) and demographically similar controls (N = 65). Participants were assessed from age 5 until age 18. A comprehensive history of adolescent substance use was compiled for each participant and growth in ADHD and conduct disorder (CD) were modeled as they related to substance use outcomes. Results indicated that when compared with controls, adolescents with ADHD were more likely to try cigarettes, initiate alcohol use at early ages, and smoke marijuana more frequently. Furthermore, adolescents with ADHD were 4 to 5 times more likely than controls to escalate to heavy cigarette and marijuana use after trying these substances once. Adolescents with ADHD who escalated to heavy use patterns were more likely to display early cigarette use and marked problems with family members, but displayed fewer peer problems. There was evidence of baseline effects (latent intercept, measured at age 5) for both ADHD and CD on substance use outcomes. Furthermore, growth in ADHD symptoms accounted for much of the growth in CD symptoms, and consequently, escalating CD symptoms in childhood (latent slope) were viewed as a mediator of the relationship between ADHD and cigarette and marijuana use. Maternal drinking in early childhood was the strongest predictor of early adolescent alcohol use. These findings are discussed with respect to the role of ADHD in the development of adolescent risk outcomes.

Objective: Although combination pharmacotherapy is common in child and adolescent psychiatry, there has been little research evaluating it. The value of adding risperidone to concurrent psychostimulant and parent training (PT) in behavior management for children with severe aggression was tested., Method: One hundred sixty-eight children 6 to 12 years old (mean age 8.89 ± 2.01 years) with severe physical aggression were randomized to a 9-week trial of PT, stimulant (STIM), and placebo (Basic treatment; n = 84) or PT, STIM, and risperidone (Augmented treatment; n = 84). All had diagnoses of attention-deficit/hyperactivity disorder and oppositional-defiant disorder (n = 124) or conduct disorder (n = 44). Children received psychostimulant (usually Osmotic Release Oral System methylphenidate) for 3 weeks, titrated for optimal effect, while parents received PT. If there was room for improvement at the end of week 3, placebo or risperidone was added. Assessments included parent ratings on the Nisonger Child Behavior Rating Form (Disruptive-Total subscale was the primary outcome) and Antisocial Behavior Scale; blinded clinicians rated change on the Clinical Global Impressions scale., Results: Compared with Basic treatment (PT + STIM [44.8 ± 14.6 mg/day] + placebo [1.88 mg/day ± 0.72]), Augmented treatment (PT + STIM [46.1 ± 16.8 mg/day] + risperidone [1.65 mg/day ± 0.75]) showed statistically significant improvement on the Nisonger Child Behavior Rating Form Disruptive-Total subscale (treatment-by-time interaction, p = .0016), the Nisonger Child Behavior Rating Form Social Competence subscale (p = .0049), and Antisocial Behavior Scale Reactive Aggression subscale (p = .01). Clinical Global Impressions scores were substantially improved for the 2 groups but did not discriminate between treatments (Clinical Global Impressions-Improvement score ≤2, 70% for Basic treatment versus 79% for Augmented treatment). Prolactin elevations and gastrointestinal upset occurred more with Augmented treatment; other adverse events differed modestly from Basic treatment; weight gain in the Augmented treatment group was minor., Conclusions: Risperidone provided moderate but variable improvement in aggressive and other seriously disruptive child behaviors when added to PT and optimized stimulant treatment. Clinical trial registration information-Treatment of Severe Childhood Aggression (The TOSCA Study), URL: http://clinicaltrials.gov, unique identifier: NCT00796302., (Copyright © 2014 American Academy of Child and Adolescent Psychiatry. All rights reserved.)

SLC28 genes encode three plasma membrane transporter proteins, human concentrative nucleoside transporter (CNT)1, CNT2, and CNT3, all of which are implicated in the uptake of natural nucleosides and a variety of nucleoside analogs used in the chemotherapy of cancer and viral and inflammatory diseases. Mechanisms determining their trafficking toward the plasma membrane are not well known, although this might eventually become a target for therapeutic intervention. The transporter regulator RS1, which was initially identified as a short-term, post-transcriptional regulator of the high-affinity, Na(+)-coupled, glucose transporter sodium-dependent glucose cotransporter 1, was evaluated in this study as a candidate for coordinate regulation of membrane insertion of human CNT-type proteins. With a combination of studies with mammalian cells, Xenopus laevis oocytes, and RS1-null mice, evidence that RS1 down-regulates the localization and activity at the plasma membrane of the three members of this protein family (CNT1, CNT2, and CNT3) is provided, which indicates the biochemical basis for coordinate regulation of nucleoside uptake ability in epithelia and probably in other RS1-expressing cell types.

With a novel antibody against the rat Na(+)-D-glucose cotransporter SGLT2 (rSGLT2-Ab), which does not cross-react with rSGLT1 or rSGLT3, the ∼75-kDa rSGLT2 protein was localized to the brush-border membrane (BBM) of the renal proximal tubule S1 and S2 segments (S1 > S2) with female-dominant expression in adult rats, whereas rSglt2 mRNA expression was similar in both sexes. Castration of adult males increased the abundance of rSGLT2 protein; this increase was further enhanced by estradiol and prevented by testosterone treatment. In the renal BBM vesicles, the rSGLT1-independent uptake of [(14)C]-α-methyl-D-glucopyranoside was similar in females and males, suggesting functional contribution of another Na(+)-D-glucose cotransporter to glucose reabsorption. Since immunoreactivity of rSGLT2-Ab could not be detected with certainty in rat extrarenal organs, the SGLT2 protein was immunocharacterized with the same antibody in wild-type (WT) mice, with SGLT2-deficient (Sglt2 knockout) mice as negative control. In WT mice, renal localization of mSGLT2 protein was similar to that in rats, whereas in extrarenal organs neither mSGLT2 protein nor mSglt2 mRNA expression was detected. At variance to the findings in rats, the abundance of mSGLT2 protein in the mouse kidneys was male dominant, whereas the expression of mSglt2 mRNA was female dominant. Our results indicate that in rodents the expression of SGLT2 is kidney-specific and point to distinct sex and species differences in SGLT2 protein expression that cannot be explained by differences in mRNA.

In Chinese hamster ovary cells expressing rabbit sodium-dependent glucose transporter (rbSGLT1) protein kinase A (PKA) activators (forskolin and 8-Br-cAMP) stimulated alpha-methyl D-glucopyranoside uptake. Kinetic analysis revealed an increase in both V(max) and affinity of the transport. Immunohistochemistry and biotinylation experiments showed that this stimulation was accompanied by an increased amount of SGLT1 localized into the plasma membrane, which explains the higher V(max) of the transport. Cytochalasin D only partly attenuated the effect of forskolin as did deletion of the PKA phosphorylation site of SGLT1 in transient transfection studies. Experiments using an anti-phosphopeptide antibody revealed that forskolin also increased the extent of phosphorylation of SGLT1 in the membrane fraction. These results suggested that regulation of SGLT1 mediated glucose transport involves an additional direct effect on SGLT1 by phosphorylation. To evaluate this assumption further, phosphorylation studies of recombinant human SGLT1 (hSGLT1) in vitro were performed. In the presence of the catalytic subunit PKA and [(32)P] ATP 1.05 mol of phosphate were incorporated/mol of hSGLT1. Additionally, phosphorylated hSGLT1 demonstrated a reduction in tryptophan fluorescence intensity and a higher quenching by the hydrophilic Trp quencher acrylamide, particularly in the presence of D-glucose. These results indicate that PKA-mediated phosphorylation of SGLT1 changes the conformation of the empty carrier and the glucose carrier complex, probably causing the increase in transport affinity. Thus, PKA-mediated phosphorylation of the transporter represents a further mechanism in the regulation of SGLT1-mediated glucose transport in epithelial cells, in addition to a change in surface membrane expression.

Context: There is mounting evidence of neurodevelopmental alterations implicating the prefrontal cortex (PFC) and basal ganglia in children with attention-deficit/hyperactivity disorder (ADHD). The brain undergoes substantive structural and functional changes with a differential timing between brain regions during development from childhood to adolescence. In vivo phosphorus 31 magnetic resonance spectroscopy ((31)P MRS) is a noninvasive neuroimaging approach that is sensitive in assessing developmental changes of overproducing/pruning of synapses., Objective: To provide support for a developmental mechanism targeting a bottom-up dysfunction of the basal ganglia impairing the fine-tuning of prefrontal functions in ADHD., Design: Cross-sectional study., Setting: Pittsburgh, Pennsylvania, and the surrounding areas., Participants: Thirty-one psychostimulant-naive children with ADHD (mean [SD] age, 8.1 [1.2] years; range, 6.1-10.0 years) and 36 healthy control subjects (mean [SD] age, 8.1 [1.3] years; range, 6.1-10.4 years)., Main Outcome Measure: Membrane phospholipid (MPL) precursor levels (ie, phosphomonoesters that are anabolic metabolites of MPL) were assessed in the PFC and basal ganglia as well as in 4 other brain regions using in vivo (31)P MRS., Results: Lower bilateral MPL precursor levels in the basal ganglia and higher MPL precursor levels in the inferior parietal region (primarily right side) were noted in the children with ADHD as compared with healthy control children. There was a group x age interaction in the PFC and inferior parietal region, with relatively older psychostimulant-naive children with ADHD showing significantly lower PFC and higher inferior parietal MPL precursor levels. No differences between groups were noted in the superior temporal, posterior white matter, or occipital regions., Conclusion: Though based on cross-sectional data, these results are suggestive of possible progressive, nonlinear, and sequential alterations implicating a bottom-up developmental dysfunction in parts of the cortico-striato-thalamo-cortical network in ADHD.

The predictive validity of symptom criteria for different subtypes of ADHD among children who were impaired in at least one setting in early childhood was examined. Academic achievement was assessed seven times over 8 years in 125 children who met symptom criteria for ADHD at 4-6 years of age and in 130 demographically-matched non-referred comparison children. When intelligence and other confounds were controlled, children who met modified criteria for the predominantly inattentive subtype of ADHD in wave 1 had lower reading, spelling, and mathematics scores over time than both comparison children and children who met modified criteria for the other subtypes of ADHD. In some analyses, children who met modified criteria for the combined type had somewhat lower mathematics scores than comparison children. The robust academic deficits relative to intelligence in the inattentive group in this age range suggest either that inattention results in academic underachievement or that some children in the inattentive group have learning disabilities that cause secondary symptoms of inattention. Unexpectedly, wave 1 internalizing (anxiety and depression) symptoms independently predicted deficits in academic achievement controlling ADHD, intelligence, and other predictors.

After decades of conflicting studies, the relation of coffee drinking to coronary artery disease (CAD) risk remains unresolved. Using Cox proportional-hazards models with 5 covariates, 127,212 subjects who supplied baseline data at voluntary health examinations from 1978 to 1985 were studied. Subsequently, 8,357 subjects were hospitalized for CAD. Coffee drinking was unrelated to CAD risk in 58,888 never smokers, but in ex-smokers and current baseline smokers, daily coffee intake was associated with higher CAD risk. This disparity was generally consistent in stratified subgroups. In conclusion, this relation of coffee consumption to increased CAD risk only in smokers could be explained by incomplete control for smoking, by other traits of smokers, or by an adverse biologic interaction of a coffee ingredient with smoking effect on CAD.

Children with attention-deficit/hyperactivity disorder (ADHD) are at risk for adverse outcomes such as substance abuse and criminality, particularly if they develop conduct problems. Little is known about early predictors of the developmental course of conduct problems among children with ADHD, however. Parental psychopathology and parenting were assessed in 108 children who first met Diagnostic and Statistical Manual of Mental Disorders (4th ed.) criteria for ADHD at 4-7 years old. When demographic variables and baseline ADHD and conduct problems were controlled, maternal depression predicted conduct problems 2-8 years following the initial assessment, whereas positive parenting during the structured parent- child interaction task predicted fewer future conduct problems. These findings suggest that maternal depression is a risk factor, whereas early positive parenting is a protective factor, for the developmental course of conduct problems among children with ADHD., (Copyright 2006 APA, all rights reserved.)

The product of gene RSC1A1, named RS1, is involved in transcriptional and posttranscriptional regulation of sodium-d-glucose cotransporter SGLT1, and removal of RS1 in mice led to an increase of SGLT1 expression in small intestine and to obesity (Osswald C, Baumgarten K, Stümpel F, Gorboulev V, Akimjanova M, Knobeloch K-P, Horak I, Kluge R, Joost H-G, and Koepsell H. Mol Cell Biol 25: 78-87, 2005). Previous data showed that RS1 inhibits transcription of SGLT1 in LLC-PK1 cells derived from porcine kidney. A decrease of the intracellular amount of RS1 protein was observed during cell confluence, which was paralleled by transcriptional upregulation of SGLT1. In the present study, the subcellular distributions of endogenously expressed RS1 and SGLT1 were compared in LLC-PK1 cells and human embryonic kidney (HEK)-293 cells using immunofluorescence microscopy. RS1 was located at the plasma membrane, at the entire trans-Golgi network (TGN), and within the nucleus. Treatment of LLC-PK1 cells with brefeldin A induced rapid release of RS1 from the TGN, and confluence of LLC-PK1 cells was accompanied by reduction of nuclear location of RS1; 84-90% of subconfluent cells and 5-34% of confluent cells contained RS1 in the nuclei. This suggests that confluence-dependent transcriptional inhibition by RS1 is partially regulated by nuclear migration. Furthermore, we assigned SGLT1 to microtubule-associated tubulovesicular structures and dynamin-containing parts of the TGN. The data indicate that RS1 inhibits the dynamin-dependent release of SGLT1-containing vesicles from the TGN.

This multi-voxel, phosphorus magnetic resonance spectroscopy ((31)P MRS) study examined the prefrontal cortex (PFC), basal ganglia (BG) and superior temporal (ST) region in 10 children with attention-deficit/hyperactivity disorder (ADHD) and 15 healthy controls. ADHD patients had lower PFC and BG phosphomonoester (PME) levels compared to healthy children. No differences were noted in the ST. These deficits in membrane phospholipid (MPL) precursor levels suggest reduced mass of cellular MPLs due to a possible underdevelopment of neuronal processes and synapses in ADHD.

A link exists between alcohol intake and increased blood pressure (BP), with many studies showing increased hypertension prevalence in heavy drinkers. The harmful and beneficial effects of alcohol can confound the study of the long-term risks of alcohol-related hypertension. We therefore studied cardiovascular sequelae separately in heavy drinkers, light drinkers, and abstainers among 127,212 subjects with BP and alcohol intake ascertained at 1978 to 1985 health examinations. Subsequent cardiovascular end points included mortality risk, hospitalization risk, and outpatient diagnosis of hypertension. Analyses were performed for all subjects and stratified by 5 alcohol-drinking categories (from never drinkers to >or=3 drinks/day). With <120/80 mm Hg as the referent, Cox proportional hazards models were used to estimate relative risks and 95% confidence intervals for 3 higher BP categories (120 to 129/80 to 84, 130 to 139/85 to 89, and >or=140/90 mm Hg). The covariates were age, gender, race, body mass index, education, and smoking. The risk of all outcomes was progressively higher for increasing BP categories, with a similarly increased risk for abstainers, light drinkers, and heavy drinkers. The interaction tests for alcohol and BP were not statistically significant for the mortality and hospitalization outcomes. Interpretation was limited by an inability to separate subjects with increased BP from alcohol consumption from those with other etiologies. In conclusion, the data indicate that the risks of hypertension are similar regardless of the amount of alcohol consumption.

Assessing impairment is an explicit component of current psychiatric diagnostic systems. A brief parent and teacher rating scale for assessing impairment was developed and studied using attention deficit hyperactivity disorder (ADHD) as an exemplar disorder. The psychometric properties of the Impairment Rating Scale (IRS) were measured in 4 samples. Two included ADHD and matched comparison children and the other 2 a school sample. Overall, IRS ratings exhibited very good temporal stability. They correlated with other impairment ratings and behavioral measures and displayed evidence of convergent and discriminant validity. The IRS was highly effective in discriminating between children with and without ADHD. Evidence that the parent and teacher IRS accounted for unique variance beyond ratings of ADHD symptoms is also presented. The scale is brief, practical, and in the public domain. The results of the studies and implications for the assessment of impairment are discussed.

Background: Little is known about the predictive validity of hyperkinetic disorder (HKD) as defined by the Diagnostic Criteria for Research for mental and behavioral disorders of the tenth edition of the International Classification of Diseases (ICD-10; World Health Organization, 1993), particularly when the diagnosis is given to younger children., Methods: The predictive validity of HKD was evaluated over a 6-year period and compared to the predictive validity of DSM-IV attention-deficit/hyperactivity disorder (ADHD) in 95 4-6-year-old children who met full criteria for at least ADHD and 122 demographically-matched nonreferred comparison children. Diagnoses were based on structured assessments of both parents and teachers., Results: All children who met full criteria for HKD also met full DSM-IV criteria for ADHD, but only 26% of ADHD children met criteria for HKD. Children who met criteria for HKD (N = 24), children who would have met criteria for HKD but were excluded from the diagnosis because they concurrently met criteria for an anxiety disorder or depression (N = 16), and the remaining children who met DSM-IV criteria for ADHD (N = 55) all exhibited significantly more symptoms of ADHD and greater social and academic impairment during years 2-7 than nonreferred comparison children. Unlike the two other diagnostic groups, however, children who met strict criteria for HKD were not more likely than comparison children to be injured unintentionally or to be placed in special education., Conclusions: Both ICD-10 HKD and DSM-IV ADHD exhibit predictive validity over 6 years, but ICD-10 HKD appears to under-identify children with persistent ADHD symptoms and related impairment. Children who met criteria for DSM-IV ADHD but not HKD exhibited at least as much functional impairment over time as hyperkinetic children.

Objective: Heavy alcohol drinking is associated with increased prevalence of systemic hypertension (HTN), but the relationship between moderate drinking and HTN remains unclear. We explored the possible role of underreporting among moderate drinkers., Method: In a cross-sectional analysis of 105,378 persons, we defined a subset among persons reporting three or fewer drinks per day that was likely to include a disproportionate number of underreporters. This subset included persons who, on another occasion, indicated intake of three or more drinks per day or who ever had a diagnosis of an alcohol-related condition; these persons are called "positive." Persons who never reported three or more drinks per day and who had no alcohol-related diagnosis were called "negative." Logistic regression models estimated the odds ratios (ORs) for prevalent HTN (140/90 mm Hg or greater) in the positive and negative subgroups, compared with lifelong abstainers as referent. All persons and four race-gender groups were studied, and they were controlled for age, education, smoking, and body mass index. We also studied the relationship of blood liver transaminase enzyme levels in the positive and negative subgroups at specific alcohol intake strata., Results: For persons reporting one to two drinks per day, the OR (95% confidence interval) of HTN was 1.32 (1.21-1.43) for positive persons and 1.16 (1.09-1.25) for negative persons. For those reporting less than one drink per day, the ORs were 0.97 (0.89-1.06) for positives and 0.92 (0.87-0.98) for negatives. For those reporting one to two drinks per day, positive/negative comparisons showed approximately a 75% increased prevalence of high liver transaminase enzymes. For those reporting less than one drink per day, the positive/negative difference was approximately 30%., Conclusion: In these data, increased prevalence of HTN among persons reporting one to two drinks per day appears to be partially due to underreporting of alcohol intake.

The Academic and Behavioral Competencies (ABC) Program, a schoolwide program to reduce classroom disruption and encourage rule following, academic task completion, and homework completion, is described. The program was initially developed and implemented in an elementary school with a high-risk population. Data from teachers, parents, and children indicate high levels of satisfaction with the program. In addition, unobtrusive measures of program impact, reported as reductions in referrals to the principal's office, suspensions, and increases in homework completion rates relative to the year prior to implementation of the program, suggest a preliminary positive impact of the program. A replication is reported for another school district, with teacher evaluations of satisfaction and effectiveness reported, supporting the flexibility and adaptability of the program. Although the present article does not constitute a systematic evaluation of the ABC Program, it presents preliminary data on the process of implementation and stakeholder satisfaction.

The sparseness of prospective data about hemorrhagic stroke (HS) risk among Asian American ethnic groups led to the investigation of 128,934 persons with self-classified ethnicity at health examinations in 1978-1985. Subsequently, 431 persons were hospitalized for HS; 31% for subarachnoid hemorrhage (SAH) and 69% for intracerebral hemorrhage (ICH). Ethnic predictors of HS were studied by Cox proportional hazard models with 7 covariates. With whites as reference, the adjusted relative risk (95% CI) of all Asians for HS was 1.6 (1.1-2.3, p = 0.01), due substantially to increased risks of SAH in Japanese people and ICH in Filipinos. These data mandate emphasis upon preventive measures in these groups.

Objective: Predictive validity is a fundamental consideration in evaluating the DSM-IV diagnostic criteria for attention deficit hyperactivity disorder (ADHD), particularly for younger children., Method: The authors conducted four annual assessments of ADHD and functional impairment using multiple informants in 255 probands and matched comparison children who were 4-6 years old in wave 1., Results: Nearly all children who met full criteria for ADHD in wave 1 met full criteria for ADHD over the next 3 years and continued to display marked functional impairment relative to comparison children, even when intelligence, co-occurring psychopathology, and demographic characteristics were controlled., Conclusions: These findings support the validity of the DSM-IV diagnosis of ADHD in younger children by demonstrating that the symptoms and associated impairment are likely to persist well into elementary school.

We recently reported that a considerable amount of the sodium-d-glucose cotransporter SGLT1 present in Caco-2 cells, a model for human enterocytes, is located in intracellular compartments attached to microtubules. A similar distribution pattern was also observed in enterocytes in thin sections from human jejunum, highlighting the validity of the Caco-2 cell model. Fluorescent surface labeling of live Caco-2 cells revealed that the intracellular compartments containing SGLT1 were accessible by endocytosis. To elucidate the role of endosomal SGLT1 in the regulation of sodium-dependent d-glucose uptake into enterocytes, we compared SGLT1-mediated D-glucose uptake into Caco-2 cells with the subcellular distribution of SGLT1 after challenging the cells with different stimuli. Incubation (90 min) of Caco-2 cells with mastoparan (50 microM), a drug that enhances apical endocytosis, shifted a large amount of SGLT1 from the apical membrane to intracellular sites and significantly reduced sodium-dependent alpha-[(14)C]methyl-D-glucose uptake (-60%). We also investigated the effect of altered extracellular D-glucose levels. Cells preincubated (1 h) with d-glucose-free medium exhibited significantly higher sodium-dependent alpha-[(14)C]methyl-D-glucose uptake (+45%) than did cells preincubated with high d-glucose medium (100 mM, 1 h). Interestingly, regulation of SGLT1-mediated d-glucose uptake into Caco-2 cells by extracellular D-glucose levels occurred without redistribution of cellular SGLT1. These data suggest that, pharmacologically, d-glucose uptake can be regulated by a shift of SGLT1 between the plasma membrane and the endosomal pool; however, regulation by the physiological substrate d-glucose can be explained only by an alternative mechanism.

Recently, we identified the extramembranous C-terminus loop 13 of SGLT1 as a binding site for the aromatic glucoside phlorizin, which competitively inhibits sodium D-glucose cotransport. Alkyl glucosides are also competitive inhibitors of the transport. Therefore, in this study, we searched for potential binding sites for alkyl glucosides in loop 13. To this end, we synthesized a photoaffinity label (2'-Azi-n-octyl)-beta-D-glucoside and analyzed the region of attachment using MALDI mass spectrometry, producing wild-type recombinant truncated loop 13. Furthermore, we prepared four single-Trp mutants of the loop and determined their fluorescence, its change in the presence of alkyl glucosides, and their accessibility to acrylamide. Photolabeling of truncated loop 13 with (2'-Azi-n-octyl)-beta-D-glucoside revealed an attachment of the C2 group of the alkyl chain to Gly-Phe-Phe-Arg (amino acid residues 598-601). In the presence of n-hexyl-beta-D-glucoside, all mutants (R601W, D611W, E621W, and L630W) exhibited a significant decrease in Trp fluorescence with an apparent binding affinity of 8-14 microM. Only L630W exhibited a significant blue shift, and only in R601W was a change in acrylamide quenching (protection) observed. No quenching or protection was found for D-glucose; however, 1-hexanol produced the same results as n-hexyl-beta-D-glucoside. The interaction shows stereoselectivity for n-hexyl-beta-D-glucoside binding; the beta-configuration of the sugar moiety at C1, the cis conformation of the unsaturated alkenyl side chain in the C3-C4 bond, and the alkyl chain length of six to eight carbon atoms lead to an optimum interaction. A schematic two-dimensional model was derived in which C2 interacts with the region around residue 601, C3 and C4 interact with the region between residues 614 and 619, and C6-C8 interact with the region between residues 621 and 630. The data demonstrate that loop 13 provides binding sites for alkyl glucosides as well as for phlorizin; thus, loop 13 of SGLT1 seems to be a major binding domain for the aglucone residues of competitive D-glucose transport inhibitors.

We investigated the distribution of the endogenous sodium-d-glucose cotransporter (SGLT1) in polarized Caco-2 cells, a model for enterocytes. A cellular organelle fraction was separated by free-flow electrophoresis and subjected to the analysis of endogenous and exogenous marker enzymes for various membrane vesicle components. Furthermore, the presence of SGLT1 was tested by an ELISA assay employing newly developed epitope specific antibodies. Thereby it was found that the major amount of SGLT1 resided in intracellular compartments and only a minor amount in apical plasma membranes. The distribution ratio between intracellular SGLT1 and apical membrane-associated SGLT1 was approximately 2:1. Further immunocytochemical investigation of SGLT1 distribution in fixed Caco-2 cells by epifluorescence and confocal microscopy revealed that the intracellular compartments containing SGLT1 were associated with microtubules. Elimination of SGLT1 synthesis by incubation of cells with cycloheximide did not significantly reduce the size of the intracellular SGLT1 pool. Furthermore, the half-life of SGLT1 in Caco-2 cells was determined to be 2.5 days by metabolic labeling followed by immunoprecipitation. Our data suggest that most of the intracellular SGLT1 are not transporters en route from biosynthesis to their cellular destination but represent an intracellular reserve pool. We therefore propose that intracellular compartments containing SGLT1 are involved in the regulation of SGLT1 abundance at the apical cell surface.

A substantially increased risk for heavy drinkers and a slightly reduced risk for lighter drinkers results in the J-shaped alcohol-mortality curve. Limited data suggest a more favorable mortality experience for drinkers of wine than for drinkers of liquor or beer. To examine these relations, the authors performed a cohort study of participants in a large Northern California prepaid health care program. Demographic and history data were collected from 128,934 adults undergoing health evaluations in 1978-1985, with subsequent death ascertained by an automated linkage system. Cox proportional hazards models with eight covariates were used to determine relative risk estimates according to total alcohol intake and days per week of drinking wine, wine types, beer, or liquor. The J-shaped alcohol-mortality relation was stable for 20 years. Independently, frequency of wine drinking was associated with lower mortality risk (p<0.001) largely because of lower coronary disease risk. Similar risk reductions were associated with red wine, white wine, other types of wine, and combinations of wine types. Much of the lower risk associated with light drinking was related to wine drinking. The authors conclude that drinkers of any type of wine have a lower mortality risk than do beer or liquor drinkers, but it remains unclear whether this reduced risk is due to nonalcoholic wine ingredients, drinking pattern, or associated traits.

ATP-binding cassette (ABC) transporters located in the hepatocyte canalicular membrane of mammalian liver are critical players in bile formation and detoxification. Although ABC transporters have been well characterized functionally, only recently have several canalicular ABC transporters been cloned and their molecular nature revealed. Subsequently, development of specific antibodies has permitted a detailed investigation of ABC transporter intrahepatic distribution under varying physiological conditions. It is now apparent that there is a complex array of ABC transporters in hepatocytes. ABC transporter molecules reside in intrahepatic compartments and are delivered to the canalicular domain following increased physiological demand to secrete bile. Insufficient amounts of ABC transporters in the bile canalicular membrane result in cholestasis (i.e., bile secretory failure). Therefore, elucidation of the intrahepatic pathways and regulation of ABC transporters may help to understand the cause of cholestasis at a molecular level and provide clues for novel therapies.

The authors examined academic task persistence, pretask expectancies, self-evaluations, and attributions of boys with attention-deficit/hyperactivity disorder (ADHD) as compared with control boys. Participants were 83 ADHD boys and 66 control boys, all normally achieving. Prior to the task, performance expectancies were assessed. After a success-failure manipulation with find-a-word puzzles, performance on subsequent trials, self-evaluations, and attributions were evaluated. Compared with controls, ADHD boys solved fewer test puzzles, quit working more often, and found fewer words on a generalization task. Consistent with these behavioral findings, research assistants rated ADHD boys as less effortful and less cooperative than control boys. Although ADHD boys did not differ significantly from controls in their posttask self-evaluations, they did differ significantly from controls in some aspects of their attributions. Attributional data indicated that ADHD boys endorsed luck as a reason for success more strongly and lack of effort as a reason for failure less strongly than controls.

ABC transporter trafficking in rat liver induced by cAMP or taurocholate and [(35)S]methionine metabolic labeling followed by subcellular fractionation were used to identify and characterize intrahepatic pools of ABC transporters. ABC transporter trafficking induced by cAMP or taurocholate is a physiologic response to a temporal demand for increased bile secretion. Administration of cAMP or taurocholate to rats increased amounts of SPGP, MDR1, and MDR2 in the bile canalicular membrane by 3-fold; these effects abated after 6 h and were insensitive to prior treatment of rats with cycloheximide. Half-lives of ABC transporters were 5 days, which suggests cycling of ABC transporters between canalicular membrane and intrahepatic sites before degradation. In vivo [(35)S]methionine labeling of rats followed by immunoprecipitation of (sister of P-glycoprotein) (SPGP) from subcellular liver fractions revealed a steady state distribution after 20 h of SPGP between canalicular membrane and a combined endosomal fraction. After mobilization of transporters from intrahepatic sites with cAMP or taurocholate, a significant increase in the amount of ABC transporters in canalicular membrane vesicles was observed, whereas the decrease in the combined endosomal fraction remained below detection limits in Western blots. This observation is in accordance with relatively large intracellular ABC transporter pools compared with the amount present in the bile canalicular membrane. Furthermore, trafficking of newly synthesized SPGP through intrahepatic sites was accelerated by additional administration of cAMP but not by taurocholate, indicating two distinct intrahepatic pools. Our data indicate that ABC transporters cycle between the bile canaliculus and at least two large intrahepatic ABC transporter pools, one of which is mobilized to the canalicular membrane by cAMP and the other, by taurocholate. In parallel to regulation of other membrane transporters, we propose that the "cAMP-pool" in hepatocytes corresponds to a recycling endosome, whereas recruitment from the "taurocholate-pool" involves a hepatocyte-specific mechanism.

Newly synthesized canalicular ectoenzymes and a cell adhesion molecule (cCAM105) have been shown to traffic from the Golgi to the basolateral plasma membrane, from where they transcytose to the apical bile canalicular domain. It has been proposed that all canalicular proteins are targeted via this indirect route in hepatocytes. We studied the membrane targeting of rat canalicular proteins by in vivo [(35)S]methionine metabolic labeling followed by preparation of highly purified Golgi membranes and canalicular (CMVs) and sinusoidal/basolateral (SMVs) membrane vesicles and subsequent immunoprecipitation. In particular, we compared membrane targeting of newly synthesized canalicular ABC (ATP-binding cassette) transporters MDR1, MDR2, and SPGP (sister of P-glycoprotein) with that of cCAM105. Significant differences were observed in metabolic pulse-chase labeling experiments with regard to membrane targeting of these apical proteins. After a chase time of 15 min, cCAM105 appeared exclusively in SMVs, peaked at 1 h, and progressively declined thereafter. In CMVs, cCAM105 was first detected after 1 h and subsequently increased for 3 h. This findings confirm the transcytotic targeting of cCAM105 reported in earlier studies. In contrast, at no time point investigated were MDR1, MDR2, and SPGP detected in SMVs. In CMVs, MDR1 and MDR2 appeared after 30 min, whereas SPGP appeared after 2 h of labeling. In Golgi membranes, each of the ABC transporters peaked at 30 min and was virtually absent thereafter. These data suggest rapid, direct targeting of newly synthesized MDR1 and MDR2 from the Golgi to the bile canaliculus and transient sequestering of SPGP in an intracellular pool en route from the Golgi to the apical plasma membrane. This study provides biochemical evidence for direct targeting of newly synthesized apical ABC transporters from the Golgi to the bile canaliculus in vivo.

The bile canaliculus contains at least four ATP-binding cassette (ABC) proteins responsible for ATP-dependent transport of bile acids (spgp), nonbile acid organic anions (mrp2), organic cations (mdr1), and phosphatidylcholine (mdr2). Other ABC transporters (including mrp3) have also been partially localized to the canaliculus; however, their function has not been fully delineated. The specific amount and function of spgp and mrp2 in the canalicular membrane increases in response to taurocholate and cAMP. The mechanism involves increased recruitment of spgp and mrp2 from Golgi to the canalicular membrane by a microtubular and PI3 kinase-dependent vesicular trafficking system. Because the effects of taurocholate and cAMP summate, two distinct pathways are proposed. Mdr family members traffic either directly to the apical plasma membrane or, in the case of spgp, through a separate intracellular pool(s); in either case, there is no direct evidence for transcytosis of ABC transporters from Golgi to basolateral plasma membrane and subsequently to the canalicular plasma membrane. Direct transfer from Golgi to apical membrane was demonstrated by in vivo pulse labeling, in vitro membrane localization, and on-line video microscopy in WIFB9 cells that were stably transfected with mdr1-GFP. A critical role for 3'-phosphoinositide products of PI3 kinase was demonstrated in the intracellular trafficking of canalicular ABC transporters and for optimal transporter activity within the canalicular membrane. These studies suggest that many intracellular components, including ATP, Ca2+, numerous GTPases, microtubules, cytoplasmic motors, and other unknown factors, are required for physiologic regulation of ABC transporter traffic from Golgi to the canalicular membrane. Defects in this complex system are postulated to produce an "intrahepatic traffic jam" that results in defective ABC transporter function in the canalicular membrane and, consequently, in cholestasis.

It is well accepted that organic osmolytes, including sorbitol, play a major role in the volume regulation of renal medullary cells. The signal leading to an activation of release channels during RVD is, however, poorly understood. Hypotonicity induced sorbitol efflux was investigated in freshly isolated rat inner medullary collecting duct (IMCD) cells and in rabbit medullary thick ascending limb of Henle's loop (TALH) cells biochemically or using labeled sorbitol. The time course of release was compared with changes in cell volume, measured by confocal microscopy, and alterations in cell calcium (Ca(i)) determined by Fura 2 technology. In IMCD cells sorbitol release, volume decrease and Ca(i) transients show a close temporal correlation. In addition increases in Ca(i) without volume changes stimulate sorbitol efflux. In TALH cells sorbitol release starts after a significant lag time and reaches a maximum when cell volume is already partially restored. The same discrepancy is observed with regard to changes in Ca(i) and sorbitol efflux. These studies suggest that in IMCD cells changes in Ca(i) are the main regulator for the sorbitol permeability of the plasma membrane. The sorbitol channel present in TALH cells seems to operate predominantly independently of Ca(i). Despite this diversity in signal transduction the sorbitol channels in both renal cell types appear, however, not to be stretch-activated., (Copyright 2000 S. Karger AG, Basel.)

Objective: Little is known about the validity of the diagnosis of attention-deficit/hyperactivity disorder (ADHD) in young children. Moreover, the results of the DSM-IV field trials raised concerns that inclusion of the new predominantly hyperactive-impulsive type of ADHD in DSM-IV might increase the likelihood of the diagnosis being given to active but unimpaired preschool and primary school children., Method: The validity of DSM-IV criteria for each subtype of ADHD was evaluated in 126 children, aged 4 through 6 years, and 126 matched comparison children. Probands and controls were classified by using structured diagnostic interviews of the parent and a DSM-IV checklist completed by the teacher., Results: Children who met DSM-IV criteria for each subtype of ADHD according to parent and teacher reports differed consistently from controls on a wide range of measures of social and academic impairment, even when other types of psychopathology and other potential confounds were controlled., Conclusions: When diagnosed by means of a structured diagnostic protocol, all three DSM-IV subtypes of ADHD are valid for 4- through 6-year-old children in the sense of identifying children with lower mean scores on measures of adaptive functioning that are independently associated with ADHD.

Assessment and treatment of attention-deficit/hyperactivity disorder (ADHD) are reviewed in order to highlight the importance of examining individual differences in treatment response. It is emphasized that treatment response in children often varies as a function of the domain measured, the setting evaluated, and intensity of the treatment. Three case studies are presented to illustrate this point. The first case study is an example of a child who showed a consistent response to medication across settings and domains and treatment intensities. The second case study is an example of a child who showed differential treatment response as a function of setting and/or treatment intensity, but was consistent across domain. The third case study is an example of a child who showed a differential response to treatment as a function of domain, but was consistent across settings and treatment intensities. These case studies highlight the need for systematic, comprehensive, individualized treatments for children with ADHD.

We have investigated the properties of the skate (Raja erinacea) and shark (Squalus acanthias) kidney Na(+)-D-glucose cotransporters (SGLT) in uptake studies of radiolabeled substrates into isolated renal brush-border membrane vesicles (BBMV). Scatchard plot analysis of the substrate dependence revealed that the Na(+)-D-glucose cotransporter population is homogenous within each species. Skate BBMV showed a relatively high affinity for D-glucose [Michaelis constant (K(m)) = 0.12 mM] with an apparent coupling ratio of approximately 2 Na+ to 1 D-glucose, whereas the shark transporter was much lower in affinity (K(m) = 1.90 mM) and had a lower coupling ratio, more like 1 Na+ to 1 D-glucose. These characteristics resemble the properties of SGLT1 and SGLT2, which are known to coexist in the mammalian kidney. Inhibitor studies using sugar analogs and glucosides suggested structural differences of the D-glucose binding site among these transporters, whereas the hydrophobic transporter domains in the vicinity of the D-glucose binding site appeared to be similar. In the high-affinity skate system, D-glucose was recognized by hydrogen bonds to the hydroxy groups at C-2, C-3, and C-4 and by hydrophobic interaction with the C-6 methylene group. In contrast, the low-affinity shark system seemed to lack the hydrophobic recognition motif for the C-6 methylene group of D-glucose.