Determination of the Cancer Genome Atlas (TCGA) Endometrial Cancer Molecular Subtypes Using the Variant Interpretation and Clinical Decision Support Software MH Guide

BACKGROUND

The Cancer Genome Atlas (TCGA) network (United States National Cancer Institute) identified four molecular endometrial cancer (EC) subtypes using an extensive multi-method approach. The aim of this study was to determine the four TCGA EC molecular subtypes using a single-method whole-exome sequencing (WES)-based approach provided by MH Guide (Molecular Health, Heidelberg, Germany).

METHODS

WES and clinical data of n = 232 EC patients were obtained from TCGA. The four TCGA EC molecular subtypes designated as (i) Mutated Polymerase ε (POLE), (ii) Microsatellite Instability (MSI), (iii) Copy Number (CN) low and, (iv) CN-high were determined using the MH Guide software. The prognostic value of the subtypes determined by MH Guide were compared with the TCGA classification.

RESULTS

Analysis of WES data using the MH Guide software led to the precise identification of the four EC molecular subtypes analogous to the TCGA classification. Both approaches displayed high concordance in terms of prognostic significance.

CONCLUSIONS

The multi-method-based TCGA EC molecular subtypes can reliably be reproduced by the single-method-based MH Guide approach. The easy-to-implement single-method MH Guide approach represents a promising diagnostic tool.

Abstract A1-33: Knowledge prioritization of cancer genomes using oncoscores and functional impact scores to support biomarker discovery and clinical decision making

Introduction: To accelerate the translation of genome information in important biological and clinical insights requires systematic integration and analysis of functional genomic and proteomic information. In this way molecular landscapes of cancer patients can be characterized efficiently to impact their care. To fully rationalize the potential treatment options for patients based on mechanistic considerations, we must understand two key parameters: (a) how important is each protein/gene to the known mechanisms underlying specific cancer types and (b) what are the functional implications of variants at the level of protein and system function. Of the many modules in our pipeline, here we present two of the components we have developed to address these questions.

Methods: Based on expert-curated data, combined with bioinformatics and text-data mining methods we have modeled (a) the relative biological importance of each gene/protein to specific cancer types, with a measure we call ‘oncoscore’ (b) the functional effects of a variant with a process we call ‘functional impact score’. First, the oncoscore method relies on multidimensional data types that summarize real-time evidence regarding clinical and molecular importance with respect to specific cancer indications. Such features include, among others, gene/protein pathway inclusion facts, drug-targetness, disease association, interaction neighborhood, as well as indication-specific protein and druggability attributes. Applying these parameters across individual cancer indications provides us with a prioritization of the functionally most important genes associated with each cancer type. Secondly, to understand the impact of aberrations we contextualized structural, functional, drug response and safety information to provide a novel approach for the prediction of functionally important aberrations. Combining the two scores permits prioritization of the functionally most important genes and aberrations in any patient tumor. Interestingly, the strategy can also be applied in absence of DNA sequence information, where the oncoscore method alone can be used to prioritize potential drug targets, again based on levels of real-time evidence.

Results: We present a subset of our results in the context of 25 different cancer conditions and demonstrate how the two scores can help prioritize the most important clinico-molecular players of a disease, decipher the most important aberrations found in patients' molecular profiles, and respectively combine this information to prioritize treatments for each indication/patient.

Conclusion: While our database contains curated information about the relationship between a gene/protein mutation and drug response within specific cancer types, we have devised two additional mechanisms to expand the clinical actionability of this information. The oncoscore and functional-impact scores provide an additional modus to decipher clinically actionable information from a patient tumor, especially when no known biomarkers are detected in the patient's profile. These methods are also particularly applicable to the identification of novel treatment biomarkers. Another advantage is that they can be used to prioritize patient treatments in the absence of sequence information, a feature that can be helpful when it comes to non-resectable disease in rare cancers. In summary, our cancer-specific integration of biological and clinical knowledge allows us to predict potentially actionable mutations in patient tumors. This is an important extension to the identification of previously known predictive biomarkers and lends itself to translational level clinical applications including biomarker discovery, drug repositioning and clinical trial prioritization for ex-guideline patients.

Citation Format: Theodoros G. Soldatos, Sasha Badbanchi, Sonia Vivas, Alexander Zien, Francesca Diella, Markus Hartenfeller, Alexander Picker, Martin A. Stein, David B. Jackson. Knowledge prioritization of cancer genomes using oncoscores and functional impact scores to support biomarker discovery and clinical decision making. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A1-33.

Erythropoietin Stimulates Tumor Growth via EphB4

While recombinant human erythropoietin (rhEpo) has been widely used to treat anemia in cancer patients, concerns about its adverse effects on patient survival have emerged. A lack of correlation between expression of the canonical EpoR and rhEpo's effects on cancer cells prompted us to consider the existence of an alternative Epo receptor. Here, we identified EphB4 as an Epo receptor that triggers downstream signaling via STAT3 and promotes rhEpo-induced tumor growth and progression. In human ovarian and breast cancer samples, expression of EphB4 rather than the canonical EpoR correlated with decreased disease-specific survival in rhEpo-treated patients. These results identify EphB4 as a critical mediator of erythropoietin-induced tumor progression and further provide clinically significant dimension to the biology of erythropoietin.

Abstract 56: MASE: A system for the molecular analysis of side effect information and its application to marketed cancer therapeutics

Adverse events (AE's) are a common and unavoidable consequence of therapeutic intervention. Nevertheless, available tomes of such data now provide us with an invaluable opportunity to study the relationship between human phenotype and drug-induced protein perturbations within a patient system. Deciphering the molecular basis of such adverse responses is not only paramount to the development of safer drugs, but it also presents a unique opportunity to dissect disease systems in search of novel response biomarkers, drug targets and efficacious combination therapies. Inspired by the potential application of this approach in clinical oncology, we have developed an in silico platform dedicated to the Molecular Analysis of Side Effect information (MASE). Combining data from the FDA's Adverse Event Reporting System (AERS) with highly curated knowledge about drug, target and pathway associations, MASE provides a biosystem level view on adverse event reports. In terms of data integration process, the free-text drug names provided by the AERS system are first mapped to standard drug synonyms. By then associating these small-molecule/biological drugs with known and predicted protein partners, we transform adverse events information from a purely drug-centric resource, to one that emphasizes the functional mediators of drug activity within the patient system.

Employing this strategy, AE cases associated with a total of 97 marketed cancer drugs were curated and contextualized. A total of 208,364 adverse event cases (i.e. 14% of all) were reported as either involving a cancer drug or cancer indication, with 1243 other drugs (79%) reported as co-medicated throughout these cases. Using this cancer-focused subset, case-specific molecular views were generated highlighting all elements of the proteome perturbed through multi-component therapies – totaling 1663 direct targets, 49 metabolizing enzymes and 407 pathways. The system may be queried to analyze side effects and outcomes associated with specific combinations of drugs, targets, metabolizing enzymes, pathways or cancer indications. Importantly, we have developed a set of analytical approaches that mine MASE for evidence of 1) efficacious target combinations 2) target combinations with increased side effects, 3) target combinations that appear to attenuate certain drug side effects. In addition, we also report a strategy to predict novel targets of established drugs, based on side effect dissimilarities between otherwise structurally comparable agents.

In summary, by permitting direct assessment relationships between the human proteome and drug-induced phenotypes, MASE provides a novel approach to the analysis and molecular dissection of AE information in oncology. Current developments are focused on the integration of patient specific clinico-molecular data and the combined application to treatment decision support.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 56. doi:10.1158/1538-7445.AM2011-56

Abstract 1618: Erythropoietin meets a new receptor

Introduction: Recent clinical trials suggest that use of erythropoietin to treat chemotherapy-induced anemia results in enhanced tumor progression and impaired survival in certain cancer patients. Rationalizing these observations with Epo's pleiotropic functionality and the lack of compelling evidence for Epo receptor (EpoR) involvement, we hypothesized the existence of a novel Epo receptor. Capturing this premise in terms of a holistic in silico strategy, we analyzed the secreted human proteome for receptors possessing structural, regulatory and functional features consistent with Epo binding and subsequent tumorigenic signaling. Our results provided EphB4 as the most likely candidate molecule.

Methods: To determine the possible association between EphB4 and Epo-mediated tumor growth, we examined several ovarian (A2780, HeyA8-MDR, SKOV3ip1) and breast (MDA-231) cancer cell lines. In addition, we selected A2780 ovarian cancer cells to develop stable clones in which either EpoR or EphB4 was silenced using shRNA (A2780 shEpoR, A2780 shEphB4). Competitive and kinetic binding studies were performed using 125I- Epo. Proliferation, migration, and invasion assays were performed as described previously. To assess the role of EpoR and EphB4 in Epo-induced tumor growth, we silenced EpoR and/or EphB4 with specific siRNAs loaded into DOPC nanoliposomes. Statistical significance was established at p< 0.05.

Results: Binding studies with 125I- Epo revealed Epo binding to EphB4 in a low-affinity fashion. Exposure of shEpoR cells to soluble EpoR showed non-competitive inhibition; however, exposure to soluble EphB4 competitively inhibited 125I- Epo binding. These results demonstrate the specificity of Epo binding to the EphB4 receptor. At pharmacologically relevant doses, Epo treatment of shEpoR cells led to activation of the Stat-3 pathway. In addition, in vitro functional assays revealed significant effects of Epo on proliferation (p=0.003), migration (p=0.006), and invasion (p=0.02) of shEpoR cells, but not shEphB4 cells. In orthotopic ovarian (Hey-A8 MDR, SKOV3ip1, A2780) and breast (MDA-231) cancer models, treatment with Epo resulted in increased tumor growth compared to untreated animals (1.1 vs. 1.6 g, p=0.05; 0.7 vs. 1.75 g, p=0.03; 0.6 vs. 1.5 g, p=0.02; .012 vs 0.4 g, p=0.006), respectively. In vivo, (A2780 and MDA-231 models), EpoR siRNA did not affect Epo-stimulated tumor growth. In contrast, EphB4 siRNA-DOPC completely blocked Epo-stimulated tumor growth.

Conclusions: Collectively, these results point to EphB4 as an alternative Epo receptor that mediates Epo-induced tumor growth by activating Stat-3. These findings offer exciting theranostic avenues for management of anemic cancer patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1618. doi:10.1158/1538-7445.AM2011-1618

Abstract A34: Conquering resistance to targeted therapies through system-based analysis of clinico-molecular information

While the advent of targeted therapies has promised to revolutionize the success of cancer treatment, a critical review of clinical response rates provides a sobering perspective on the challenge at hand. New levels of discovery innovation are urgently required to redress this enormous medical need. Focusing on primary imatinib resistance in chronic myeloid leukemia, we demonstrate that the systems-based modeling and analysis of clinico-molecular information from responder and non-responder patients can provide unique molecular insights into the sources of therapy resistance. By then utilizing these models to prioritize therapeutic drug space, the strategy elaborates rational multi-component therapies to potentially redress the issue. Moreover, by hypothesizing that co-medications may perturb the activity of resistance model components, we utilize prescription information to “probe” the functional network in search of key resistance associated targets. Not only does this method provide a novel approach to the analysis of patient information, it also permits the repositioning of drugs from independent therapeutic areas within predicted combinatorial regimens. Taken together, our results provide an exciting new approach to the computational analysis of clinico-molecular data, and suggest a future where rationally designed theranostic-linked combination therapies could significantly address the non-responder problem.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):A34.

Microarrays meet the Voltaire challenge: Drug discovery on a chip?

The co-emergence of microarray technologies with systems oriented approaches to discovery is testament to the technological and conceptual advancements of recent years. By providing a platform for massively parallelized reductionism, microarrays are enabling us to examine the functional features of diverse classes of bio-system components in a contextually meaningful manner. Yet, to provide economic impact, future development of these technologies demands intimate alignment with the goal of producing safer and more efficacious drugs.:

Structure of zinc-independent sorbitol dehydrogenase from Rhodobacter sphaeroides at 2.4 A resolution

Recombinant sorbitol dehydrogenase (SDH) from Rhodobacter sphaeroides has been crystallized in the absence of the cofactor NAD(H) and its structure determined to 2.4 A resolution using molecular replacement (refined R and R free factors of 18.8 and 23.8%, respectively). As expected from the sequence and shown by the conserved fold, SDH can be assigned to the short-chain dehydrogenase/reductase protein family. The cofactor NAD and the substrate sorbitol have been modelled into the structure and the active-site architecture, which displays the highly conserved catalytic tetrad of Asn-Ser-Tyr-Lys residues, is discussed in relation to the enzyme mechanism. This is the first structure of a bacterial SDH belonging to the SDR family.

A physical and functional map of the human TNF-alpha/NF-kappa B signal transduction pathway

Signal transduction pathways are modular composites of functionally interdependent sets of proteins that act in a coordinated fashion to transform environmental information into a phenotypic response. The pro-inflammatory cytokine tumour necrosis factor (TNF)-alpha triggers a signalling cascade, converging on the activation of the transcription factor NF-kappa B, which forms the basis for numerous physiological and pathological processes. Here we report the mapping of a protein interaction network around 32 known and candidate TNF-alpha/NF-kappa B pathway components by using an integrated approach comprising tandem affinity purification, liquid-chromatography tandem mass spectrometry, network analysis and directed functional perturbation studies using RNA interference. We identified 221 molecular associations and 80 previously unknown interactors, including 10 new functional modulators of the pathway. This systems approach provides significant insight into the logic of the TNF-alpha/NF-kappa B pathway and is generally applicable to other pathways relevant to human disease.

Children, sleep, and behavior: a complex association

Pediatric sleep physiology begins with development of the sleep/wake cycle, and the origins of active versus quiet sleep. The 24-hour circadian cycle becomes established at 3-6 months. Sleep disorders during infancy commonly include mild, usually self-limited conditions such as sleep-onset association disorder, excessive nighttime feedings, and poor limit-setting. These require behavioral management to avoid long-term deleterious sleep habits. In contrast, other sleep disorders are more ominous, including SIDS, central congenital hypoventilation syndrome, and sleep apnea. Childhood is generally considered the golden age of sleep, with brief latency to sleep onset, high efficiency, and easy awakening. Yet parasomnias, psychological factors, and sleep disturbances associated with common disorders such as ADHD disrupt the idealistic notion of childhood being a period of unfettered sleep. Adolescents have sleep requirements similar to adults, posing a challenge for them to adapt to school schedules and increasingly demanding lifestyles. Narcolepsy, usually diagnosed in adolescence or early adulthood, is a lifelong sleep disorder and has led to the identification of the hypocretin/orexin neurotransmitter system. Research advances in the complex interrelationships between developmental neurobiology, sleep disorders and behavior will lead to an enhanced understanding of the pathophysiology of sleep problems and lead to novel therapeutic strategies for sleep disturbances in children.

Indoor environmental quality in six commercial office buildings in the midwest United States

The aims of this study were to characterize physical, mechanical, and environmental factors influencing indoor environmental quality (IEQ) in commercial office buildings; document occupant perceptions and psychosocial attributes; and evaluate relationships among these parameters. Six large office buildings in metropolitan areas were selected in Iowa, Minnesota, and Nebraska. Comprehensive sampling was conducted over one week in each building, during all four seasons. This paper presents the study methods and selected results from the first round of sampling (November 1996 to April 1997). Air flow and recirculation rates were quite variable, with the proportion of outdoor air provided to occupants ranging from 10 to 79 CFM/person. Carbon dioxide, carbon monoxide, and temperature were within ranges anticipated for nonproblem buildings. Relative humidity was low, ranging from 11.7 to 24.0 percent. Indoor geometric mean concentrations of total volatile organic compounds (TVOCs) ranged from 73 to 235 microg/m3. The most prevalent compounds included xylene, toluene, 2-propanol, limonene, and heptane. Geometric mean formaldehyde concentrations ranged from 1.7 to 13.3 microg/m3, and mean acetaldehyde levels ranged from <3.0 to 7.5 microg/m3. Airborne concentrations of culturable bacteria and fungi were low, with no samples exceeding 150 CFU/m3. Total (direct count) bioaerosols were more variable, ranging from 5010 to 10,700 organisms/m3. Geometric mean endotoxin concentrations ranged from 0.5 to 3.0 EU/m3. Respirable particulates (PM10) were low (14 to 36 microg/m3). Noise levels ranged from 48 to 56 dBA, with mean light values ranging from 200 to 420 lux. Environmental parameters were significantly correlated with each other. The prevalence of upper respiratory symptoms (dry eyes, runny nose), central nervous system symptoms (headache, irritability), and musculoskeletal symptoms (pain/stiffness in shoulders/neck) were elevated compared to other studies using similar questionnaires. Importantly, psychosocial factors were significantly related to increased symptoms in females, while environmental factors were more closely correlated with symptoms in males. Endotoxin concentrations were associated with symptoms in both males and females. These data will help to identify and quantify the relative role of factors that contribute to sick building syndrome. The data collected in this study may also be used to evaluate the effectiveness of current building operation practices, and can be used to prioritize allocations of resources for reduction of risk associated with IEQ complaints.

Medical mimics. Medical and neurological conditions simulating ADHD

The medical and neurological conditions that simulate ADHD are reviewed, as well as those disorders frequently presenting as comorbidities with ADHD. The localization of ADHD has invoked multiple areas, including frontal lobes, nondominant parietal lobe, and basal ganglia, and the neural network theory of cortical-subcortical-cortical loops has been implicated in the pathogenesis of ADHD. The medical evaluation of patients presenting with ADHD should be comprehensive, with an emphasis on demonstrating chronic and permeating symptoms since early childhood without a better medical explanation. Associated thyroid disorders are reviewed, including the syndrome of resistance to thyroid hormone. Suggested laboratory studies are provided, depending on the clinical circumstances.

Sleep and behavior problems in school-aged children

OBJECTIVES

The primary purposes of the present study were to survey the prevalence of sleep problems in school-aged children and to examine these associations with parental perception of sleep problems, medical history, and childhood psychopathology.

METHODS

Sleep and medical history questionnaires and the Child Behavior Checklist were administered to the parents of 472 children between ages 4 and 12 years receiving routine pediatric care from urban, rural, and suburban pediatric practices.

RESULTS

Although sleep problems were reported for 10.8% of the sample during the past 6 months, less than one half of the parents who identified sleep problems reported that they had discussed sleep with their child's pediatrician. The best predictor of current sleep problems was a history of sleep problems before age 2 years. Sleep problems such as snoring, tiredness during the day, and taking excessive time to fall asleep were very common, occurring at least 1 night per week in over 20% of the total sample. Factor analysis of the sleep problems questionnaire resulted in 5 sleep problem factors that accounted for 58.7% of the variance. Specific sleep problem factors include: parasomnias, enuresis/gags, tiredness, noisy sleep, and insomnia. Sleep problem factor scores were differentially associated with medical history variables and measures of childhood psychopathology. Children rated highly on parasomnias were more likely to have frequent falls and to display pica. Parasomnias and noisy sleep were inversely associated with socioeconomic status (SES). Children from lower SES families were rated higher on these factors than children from higher SES families. Enuresis/gags was the only sleep problem factor associated with age. Younger children scored higher on this factor. Duration of naps was highly correlated with age and with bed times during the week and weekends. As expected, younger children were more likely to nap for longer periods and to have earlier bed times. In addition, higher tiredness factor scores were associated with napping and with later bed times during the week and weekend. Boys were much more likely than were girls to have higher scores on enuresis/gags, and higher enuresis/gags scores were associated with an increased prevalence of trauma and falls. Bed times were not associated with any other sleep problem factor score. Children rated highly on tiredness were more likely to have a history of hospitalizations. Tiredness factor scores were strongly associated with the sleep practice of sharing a bed but not with sharing a room. Sharing a room was not associated with any sleep problem factor score. High scores on noisy sleep were associated with allergies, falls frequently, and with sharing a bed. Children with high scores on the insomnias were also more likely to display an increased prevalence of allergies.

CONCLUSIONS

Parental perception of global sleep problems was surprisingly common in school-aged children receiving routine pediatric care. Parental reports of their children's sleep problems may be a red flag for specific sleep problems and psychiatric, social, or medical problems. Sleep problems should be queried about during pediatric visits for school-aged children.

A fluorescence microscopy based genetic screen to identify mutants altered for interactions with host cells

The study of microbial intracellular pathogenesis has benefited from the application of immunofluorescence microscopy to characterize interactions of the pathogen with host cells. Unfortunately, immunofluorescence microscopy is impractical for screening the large number of bacterial mutants necessary to represent the entire genome of the pathogen. Screening has been limited due to the lack of materials suitable for high-throughput processing (e.g. 96-well plates) that also possess the optical features needed for high resolution fluorescence microscopy. Recently marketed 96-well Special Optics (SO) plates provide both the 96-well template ideal for high-throughput analysis and optical features suitable for fluorescence microscopy. Until this work, mutants needed for the study of a fluorescence-based virulence phenotype could not be obtained by direct screening approaches. In this study, SO plates were used to examine 11520 individual Salmonella typhimurium MudJ mutants for the loss of the ability to disrupt host cell endocytic compartments. The direct application of the fluorescence phenotype for screening allowed us to obtain a set of mutants to characterize the formation of lysosomal membrane glycoprotein (lgp) containing tubules upon Salmonella infection of HeLa epithelial cells. This approach will facilitate the characterization of a wide range of microbial phenotypes detectable by fluorescence microscopy.

Aggregation of host endosomes by Salmonella requires SPI2 translocation of SseFG and involves SpvR and the fms-aroE intragenic region

Salmonella-induced aggregation of host endosomal compartments into tubules, termed lgp-tubules, requires sifA and ompR. Lgp-tubules result from Salmonella-directed alteration of the endocytic system and typify the unique intracellular locale where Salmonella replicate. A high-throughput method devised to screen 11 520 MudJ mutants for loss of lgp-tubule formation identified one auxotrophic and nine prototrophic mutants. Molecular characterization identified four new loci required to alter epithelial endocytic structure. Salmonella pathogenicity island 2 (SPI2) is the locus central to the phenotype. A subset of SPI2 effectors is essential: SpiC and SseFG are required, but not SseE. A subset of apparatus proteins is also implicated: SsaJ, L, M, V and P are required. SPI2 was implicated further, as SifA shows similarity with known SPI2 translocation targets, and OmpR regulates SPI2. Another locus lies within the smf-aroE intragenic region. Lgp-tubule formation also involves a locus on the virulence plasmid pSLT. The pSLT-encoded SpvR negatively regulates an unknown repressor of the phenotype located on pSLT. Finally, disruption of carB leads to multiple auxotrophy that prevents lgp-tubule formation. This study demonstrates that lgp-tubule formation is a virulence mechanism that underlies the selective disruption of host endocytic trafficking and is associated with the formation of a replication-permissive locale.

Unravelling sleep problems in treated and untreated children with ADHD

This study investigated parental perception of sleep problems in stimulant treated and untreated children with Attention Deficit Hyperactivity Disorder (ADHD). Parents of 135 psychiatric clinic referred children and 83 pediatric outpatients completed a sleep questionnaire and the Child Behavior Checklist. Moderate to severe "sleep problems" reportedly occurred at least once a week in 19.3% of children with ADHD, 13.3% of the psychiatric controls, and 6.2% of the pediatric controls. Children with ADHD treated with stimulants were reported to display a higher prevalence of nightly "severe" sleep problems than did untreated children with ADHD. Almost a third (29%) of stimulant treated ADHD children were reported to display increased sleep latency or insomnia every night versus 10% of untreated children with ADHD. Despite the high prevalence of sleep related problems in ADHD, the significance of the association between delayed sleep onset and ADHD with regard to etiology and management of ADHD is still poorly understood.

The third factor of the WISC-III: it's (probably) not freedom from distractibility

OBJECTIVE

This study examined the ecological validity, construct validity, and diagnostic utility of the third factor of the WISC-III, heuristically labeled "Freedom From Distractibility" (FFD).

METHOD

A sample of 200 children, aged 6 to 11 years, with attention-deficit hyperactivity disorder (ADHD) completed the WISC-III, the Wide Range Achievement Test-Revised, and the Test of Variables of Attention. Objective parent and teacher report measures of attention and hyperactivity were completed.

RESULTS

Mean FFD scores were significantly lower than other WISC-III factor scores. The diagnostic utility of FFD is limited, however, as the majority of these children did not show a significant relative weakness on this index. Correlational analyses failed to support the concurrent, ecological, or construct validity of the FFD. FFD scores were not correlated with a measure of sustained visual attention. Findings suggest that among children with ADHD, a low FFD score may be associated with the presence of a learning disability or poor academic performance. This finding was maintained after level of general intelligence was statistically controlled.

CONCLUSIONS

Clinicians and researchers should not view FFD as a reliable or valid index of attention or as a diagnostic screening measure for identifying children with ADHD.

Validity of DSM-IV attention-deficit/hyperactivity disorder for younger children

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.

Trafficking of porin-deficient Salmonella typhimurium mutants inside HeLa cells: ompR and envZ mutants are defective for the formation of Salmonella-induced filaments

Outer membrane porin genes of Salmonella typhimurium, including ompC, ompF, and tppB, are regulated by the products of ompB, a two-component regulatory locus encoding OmpR and EnvZ. S. typhimurium ompR mutants are attenuated in mice, but to date no one has studied the intracellular trafficking of S. typhimurium porin-deficient mutants. In this study, isogenic transposon mutants of S. typhimurium with insertions in ompR, envZ, ompF, ompC, ompD, osmZ, and tppB were compared with wild-type SL1344 for trafficking in the human epithelial cell line HeLa. We found that ompR and envZ mutants were reduced or completely inhibited for the formation of Salmonella-induced filaments (Sifs). This result was confirmed with an ompB deletion mutant. Sifs are tubular structures containing lysosomal glycoprotein which are induced specifically by intracellular Salmonella. Genetic analysis showed that the ompR mutation could be complemented in trans by cloned ompR to restore its ability to induce Sifs. In contrast, mutations in the known ompR-regulated genes ompF, ompC, and tppB (as well as the ompR-independent porin gene, ompD) had no effect on Sif formation relative to that of wild-type SL1344, thus indicating that OmpR does not exert its role on these genes to induce Sif formation. The omp mutants studied were able to invade and replicate in HeLa cells at levels comparable to those in wild-type SL1344. We conclude that OmpR and EnvZ appear to regulate Sif formation triggered by intracellular S. typhimurium.

Cloning, nucleotide sequence, and overexpression of smoS, a component of a novel operon encoding an ABC transporter and polyol dehydrogenases of Rhodobacter sphaeroides Si4

The gene coding for sorbitol dehydrogenase (SDH) of Rhodobacter sphaeroides Si4 was located 55 nucleotides upstream of the mannitol dehydrogenase gene (mtlK) within a previously unrecognized polyol operon. This operon probably consists of all the proteins necessary for transport and metabolization of various polyols. The gene encoding SDH (smoS) was cloned and sequenced. Analysis of the deduced amino acid sequence revealed homology to enzymes of the short-chain dehydrogenase/reductase protein family. For structure analysis of this unique bacterial enzyme, smoS was subcloned into the overexpression vector pET-24a(+) and then overproduced in Escherichia coli BL21(DE3), which yielded a specific activity of 24.8 U/mg of protein and a volumetric yield of 38,000 U/liter. Compared to values derived with the native host, R. sphaeroides, these values reflected a 270-fold increase in expression of SDH and a 971-fold increase in the volumetric yield. SDH was purified to homogeneity, with a recovery of 49%, on the basis of a three-step procedure. Upstream from smoS, another gene (smoK), which encoded a putative ATP-binding protein of an ABC transporter, was identified.

Mannitol dehydrogenase from Rhodobacter sphaeroides Si4: subcloning, overexpression in Escherichia coli and characterization of the recombinant enzyme

By polymerase chain reaction mutagenesis techniques, an NdeI restriction site was introduced at the initiation codon of the mannitol dehydrogenase (MDH) gene (mtlK) of Rhodobacter sphaeroides Si4. The mtlK gene was then subcloned from plasmid pAK74 into the NdeI site of the overexpression vector pET24a+ to give plasmid pASFG1. Plasmid pASFG1 was introduced into Escherichia coli BL21(DE3), which was grown in a 1.5-1 bioreactor at 37 degrees C and pH 7.0. Overexpression of MDH in Escherichia coli BL21(DE3) [pASFG1] was determined by enzymatic analysis and sodium dodecyl sulfate (SDS)/polyacrylamide gel electrophoresis. Under standard growth conditions, E. coli produced considerable amounts of a polypeptide that correlated with MDH in SDS gels, but the activity yield was low. Decreasing the growth temperature to 27 degrees C and omitting pH regulation resulted in a significant increase in the formation of soluble and enzymatically active MDH up to a specific activity of 12.4 U/mg protein and a yield of 26,000 U/l, which corresponds to 0.38 g/l MDH. This was an 87-fold overexpression of MDH compared to that of the natural host R. sphaeroides Si4, and a 236-fold improvement of the volumetric yield. MDH was purified from E. coli BL21(DE3) [pASFG1] with 67% recovery, using ammonium sulfate precipitation, hydrophobic interaction chromatography, and gel filtration. Partial characterization of the recombinant MDH revealed no significant differences to the wild-type enzyme.

Behavioral effects of liothyronine (L-T3) in children with attention deficit hyperactivity disorder in the presence and absence of resistance to thyroid hormone

Evidence that the thyroid may play a role in the pathogenesis of attention deficit hyperactivity disorder (ADHD) comes from observations that 48% to 73% of children with the syndrome of resistance to thyroid hormone (RTH) have ADHD. Casual observations in subjects with RTH have suggested that treatment with thyroid hormone may improve the symptoms of ADHD. The aim of this study was to determine whether thyroid hormone has a beneficial effect on the behavior of children with RTH. A prospective, randomized, double-blinded, placebo-controlled, cross-over study was conducted to evaluate the effect of the rapid acting thyroid hormone, liothyronine (L-T3), on the behavior of 8 children with ADHD + RTH, and 9 children with ADHD and normal thyroid function (ADHD Only). Parent and teacher ratings of hyperactivity (Conners scale) and a computerized continuous performance test (CPT) were used as objective measures of hyperactivity, attention and impulsivity. L-T3 had no effect on Conners Hyperactivity Index in 7 of 9 children with ADHD Only; it caused improvement and deterioration in 1 subject each. In contrast, the rating in 5 of 8 subjects with ADHD + RTH showed improvement, whereas 3 of 8 subjects remained unchanged. L-T3 was associated with increased commission errors in 5 of 8 children with ADHD Only and decreased commission errors in 4 of 7 with ADHD + RTH. In children with RTH and ADHD, particularly those that exhibit hyperactivity, L-T3 in supraphysiological doses may be beneficial in reducing hyperactivity and impulsivity. In the majority of children with ADHD who do not have RTH, L-T3 treatment has no effect or may be detrimental.

Release of lipopolysaccharide from intracellular compartments containing Salmonella typhimurium to vesicles of the host epithelial cell

The biological effects of bacterial lipopolysaccharide (LPS) on eucaryotic cells have traditionally been characterized following extracellular challenge of LPS on susceptible cells. In this study, we report the capacity of Salmonella typhimurium to release LPS once it is located in the intracellular environment of cultured epithelial cells. LPS is liberated from vacuolar compartments, where intracellular bacteria reside, to vesicles present in the host cell cytosol. The vesicle-associated LPS is detected in infected cells from the time when invading bacteria enter the host cell. Release of LPS is restricted to S. typhimurium-infected cells, with no LPS observed in neighboring uninfected cells, suggesting that dissemination of LPS occurs entirely within the intracellular environment of the infected cell. The amount of LPS present in host vesicles reaches a maximum when intracellular S. typhimurium cells start to proliferate, a time at which the entire host cell cytosol is filled with numerous vesicles containing LPS. All these data support the concept that intracellular bacterial pathogens might signal the host cell from intracellular locations by releasing bioactive bacterial components such as LPS.

Characterization of EspC, a 110-kilodalton protein secreted by enteropathogenic Escherichia coli which is homologous to members of the immunoglobulin A protease-like family of secreted proteins

Enteropathogenic Escherichia coli (EPEC) secretes at least five proteins. Two of these proteins, EspA and EspB (previously called EaeB), activate signal transduction pathways in host epithelial cells. While the role of the other three proteins (39, 40, and 110 kDa) remains undetermined, secretion of all five proteins is under the control of perA, a known positive regulator of several EPEC virulence factors. On the basis of amino-terminal protein sequence data, we cloned and sequenced the gene which encodes the 110-kDa secreted protein and examined its possible role in EPEC signaling and interaction with epithelial cells. In accordance with the terminology used for espA and espB, we called this gene espC, for EPEC-secreted protein C. We found significant homology between the predicted EspC protein sequence and a family of immunoglobulin A (IgA) protease-like proteins which are widespread among pathogenic bacteria. Members of this protein family are found in avian pathogenic Escherichia coli (Tsh), Haemophilus influenzae (Hap), and Shigella flexneri (SepA). Although these proteins and EspC do not encode IgA protease activity, they have considerable homology with IgA protease from Neisseria gonorrhoeae and H. influenzae and appear to use a export system for secretion. We found that genes homologous to espC also exist in other pathogenic bacteria which cause attaching and effacing lesions, including Hafnia alvei biotype 19982, Citrobacter freundii biotype 4280, and rabbit diarrheagenic E. coli (RDEC-1). Although these strains secrete various proteins similar in molecular size to the proteins secreted by EPEC, we did not detect secretion of a 110-kDa protein by these strains. To examine the possible role of EspC in EPEC interactions with epithelial cells, we constructed a deletion mutant in espC by allelic exchange and characterized the mutant by standard tissue culture assays. We found that EspC is not necessary for mediating EPEC-induced signal transduction in HeLa epithelial cells and does not play a role in adherence or invasion of tissue culture cells.

Enteropathogenic Escherichia coli markedly decreases the resting membrane potential of Caco-2 and HeLa human epithelial cells

It is presumed, but not proven, that enteropathogenic Escherichia coli (EPEC) causes secretory diarrhea by altering ion transport in enterocytes. In this study we used the whole-cell, current clamp variant of the patch clamp technique to demonstrate that EPEC infection of HeLa and Caco-2 human epithelial cells reduces cell resting membrane potential. The observed reduction of resting membrane potential in HeLa cells results from EPEC-mediated signal transduction to the host cell but is not dependent upon EPEC-mediated elevation of levels of intracellular free calcium. These findings indicate that EPEC can directly alter the relative distribution of ions across epithelial host cell membranes. This may be relevant to the etiology of diarrhea caused by EPEC infection.

Enteropathogenic E. coli exploitation of host epithelial cells

Enteropathogenic E. coli (EPEC) is a leading cause of neonatal diarrhea worldwide. These organisms adhere to the intestinal cell surface, causing rearrangement in the epithelial cell surface and underlying cytoskeleton, resulting in a structure termed an attaching/effacing (A/E) lesion. A/E lesion formation is thought necessary for EPEC-mediated disease. EPEC secretes several proteins that trigger signal transduction, intimate adherence, and cytoskeletal rearrangements in epithelial cells. Additionally, it produces intimin, an outer membrane product that mediates intimate adherence. Together these various bacterial molecules contribute to the intimate relationship that is formed by EPEC with host epithelial cells which results in A/E lesion formation and diarrhea.

Methylphenidate dosing: twice daily versus three times daily

OBJECTIVE

To evaluate the short-term efficacy and side effects associated with two methylphenidate hydrochloride (MPH) dosing patterns.

METHODS

Twenty-five boys with attention deficit hyperactivity disorder (ADHD) participated in a 5-week, triple-blind, placebo-controlled, crossover evaluation of MPH administered twice (b.i.d.) versus thrice (t.i.d.) per day (mean dose = 8.8 +/- 5 mg, .30 +/- .1 mg/kg/dose). Four dosing conditions (placebo, titration [gradual increase to target dose], b.i.d., and t.i.d.) were used. Dependent measures obtained on a weekly basis included: parent and teacher ratings of child behavior, parent-child conflicts, parent report of stimulant side effects, child self-report of mood symptoms, a sleep log, laboratory measures of attention, and actigraphic recording of sleep activity.

RESULTS

All dosing conditions resulted in significant effects on ADHD symptoms when compared with baseline. Relative to placebo, t.i.d. dosing was characterized by improvement on the greatest number of behavioral measures, and both b.i.d. and t.i.d. were generally more effective than titration. Direct comparisons of b.i.d. and t.i.d. dosing revealed that t.i.d. was associated with greater improvement on the Conners Parent Rating Scale Impulsivity/Hyperactivity factor, with a similar marginally significant effect for the ADD-H Teacher Rating Scale Hyperactivity factor. The analysis of clinically significant change favored a three-times-a-day dosing schedule over placebo on both parent and teacher ratings of impulsivity/hyperactivity and attention. Compared with placebo, appetite suppression was rated, on average, as more severe in the t.i.d. and titration conditions, but not in the b.i.d. condition. However, the number of subjects who exhibited any or severe appetite suppression did not differ significantly between the b.i.d. and t.i.d. schedules. Although there was no difference in sleep duration for children on b.i.d. and t.i.d. schedules, total sleep time appeared to decrease slightly on t.i.d. relative to placebo according to both parent ratings and actigraphic assessment. There were no significant differences between b.i.d. and t.i.d. on any other side effects or sleep variables.

CONCLUSIONS

For many children with ADHD, t.i.d. dosing may be optimal. There are few differences in acute side effects between b.i.d. and t.i.d. MPH dosing. The dosing schedule should be selected according to the severity and time course of ADHD symptoms rather than in anticipation of dosing schedule-related side effects.

Resolution of intracranial calcifications in infants with treated congenital toxoplasmosis

PURPOSE

To determine the natural history of intracranial calcifications in infants with treated congenital toxoplasmosis.

MATERIALS AND METHODS

Between January 1982 and March 1994, cranial computed tomography was performed in 56 infants with treated congenital toxoplasmosis when they were newborns and approximately 1 year old. Locations and sizes of intracranial calcifications were noted.

RESULTS

Forty newborns had intracranial calcifications. By 1 year of age, calcifications diminished or resolved in 30 (75%) and remained stable in 10 (25%) of these treated infants. Ten (33%) of the 30 infants whose calcifications diminished versus seven (70%) of the 10 infants with stable calcifications received less intensive antimicrobial treatment than the other treated infants. In contrast, a small number of infants who were untreated or treated 1 month or less had intracranial calcifications that increased or remained stable during their 1st year of life.

CONCLUSION

Diminution or resolution of intracranial calcifications was an unexpected and remarkable finding in infants with treated, congenital toxoplasmosis, consonant with their improved neurologic functioning.

Identification of a Salmonella virulence gene required for formation of filamentous structures containing lysosomal membrane glycoproteins within epithelial cells

Salmonella species are facultative intracellular pathogens that invade epithelial cells and reside within lysosomal membrane glycoprotein (lgp)-containing vacuoles. Coincident with the onset of bacterial replication inside these vacuoles, Salmonella induce the formation of stable lgp-containing filamentous structures that connect with the Salmonella-containing vacuoles. Salmonella typhimurium SL1344::Tn l0dCm mutant strains unable to induce these structures were isolated. All contained insertions within a novel Salmonella induced filament gene A (sifA). sifA is present only in Salmonella species and encodes a protein with a predicted molecular mass of 38 kDa and an apparent molecular mass of 35 kDa. sifA is flanked by 300 base pairs, and sifA and its flanking DNA show no homology to sequences in DNA databases. sifA is located within the potABCD operon, a housekeeping locus involved in periplasmic transport of polyamines. Fourteen-base-pair direct repeats mark the probable site of integration of sifA and its flanking DNA have a significantly reduced G+C content (41%) when compared with the potABCD operon (51%) and the Salmonella genome (52-54%). Deletion mutant strains in sifA or in the downstream potC were constructed. Delta sifA does not produce Salmonella-induced filaments in epithelial cells, and is attenuated in mice. Delta potC produces Salmonella-induced filaments in epithelial cells, and was fully virulent. Collectively, these results suggest that sifA arose by horizontal gene transfer into Salmonella and its product is involved in a virulence-associated intracellular phenotype related to Salmonella-induced filament formation.

Behavioral and cognitive effects of methylxanthines. A meta-analysis of theophylline and caffeine

BACKGROUND

Theophylline has been extensively studied as a treatment of asthma. However, some studies have suggested that theophylline may precipitate adverse behavioral and cognitive effects on children. Other reports have evaluated the effects of caffeine, another commonly used methylxanthine, as a treatment of attention-deficit hyperactivity disorder.

OBJECTIVE

To present a meta-analysis of research on the behavioral and cognitive effects of methylxanthines in children.

METHODS

The meta-analyses were conducted on 12 studies of theophylline and nine studies of caffeine that met inclusion criteria.

RESULTS

In contrast to popular beliefs and earlier scientific reports, meta-analyses of controlled studies did not indicate that either theophylline or caffeine resulted in significant deleterious effects on cognition or behavior. In fact, there was a small, positive effect on parental report of externalizing behavior for both methylxanthines.

CONCLUSIONS

There is little evidence to suggest that methylxanthines have adverse cognitive or behavioral effects on children. Questions remain with regard to the identification and determinants of either responsive or sensitive subgroups, dose-response relationships, and the effects of parent-teacher expectancies on behavioral ratings.

Psychiatric and developmental disorders in families of children with attention-deficit hyperactivity disorder

OBJECTIVE

To evaluate whether a pediatric family history obtained via a brief parent interview would reveal a high prevalence of psychiatric and developmental disorders in the family members of children with attention-deficit hyperactivity disorder (ADHD) compared with a group of children with another chronic developmental disability, Down syndrome (DS).

DESIGN

A controlled cross-sectional group comparison study.

SETTING

An interdisciplinary hyperactivity and learning problem clinic and a DS clinic located in a large, urban tertiary care teaching hospital in Chicago, Ill.

PARTICIPANTS

A total of 140 children with ADHD and 163 children with DS of comparable socioeconomic status.

MEASURES

Using a screening questionnaire and parent interview, the development pediatricians obtained a family history.

RESULTS

By parent report, children with ADHD were significantly more likely than the control children with DS to have a parent affected by alcoholism (P = .007), other drug abuse (P < .001), depression (P < .001), delinquency (P < .001), learning disabilities (P < .001), and ADHD (P < .001). Similar patterns were evidenced in other first- and second-degree relatives.

CONCLUSIONS

The high reported frequency of psychiatric and developmental disorders in the families of children with ADHD requires that the treating clinician explore the area of family psychiatric and developmental history and use the findings to formulate a comprehensive treatment plan that includes anticipatory guidance and psychosocial intervention.

Neurocognitive characteristics of individuals with resistance to thyroid hormone: comparisons with individuals with attention-deficit hyperactivity disorder

Previous studies have demonstrated an association between resistance to thyroid hormone (RTH) and attention-deficit hyperactivity disorder (ADHD). To determine if the neurocognitive characteristics in individuals with RTH are similar to those observed in ADHD, 12 children with RTH from 7 families were matched to 12 children with ADHD without RTH. Subjects were administered standardized intellectual, developmental, and school achievement tests. Parent and teacher ratings of children's hyperactivity and attention were similar for both groups, as were measures of attention, impulsivity, and verbal IQ. Children with RTH displayed lower nonverbal intelligence (performance IQ = 85) and academic achievement (> 1-2 SD below the mean) when compared with those with ADHD only (performance IQ = 99; achievement within 2 SD). Although children with RTH have behavioral characteristics similar to those with ADHD, their significantly weaker abilities of perceptual-organization and lower school achievement suggest a more severe neurobehavioral impairment than ADHD.

Lowering hospital charges in the trauma intensive care unit while maintaining quality of care by increasing resident and attending physician awareness

OBJECTIVE

The goal of this study was to determine if trauma intensive care unit (TICU) charges could be reduced through informal daily bedside resident-attending physician discussions regarding relative patient costs of diagnostic and therapeutic alternatives.

DESIGN

This was a prospective pre- and postinterventional study.

SETTING

The study took place in a TICU in a level I, community-based, university-affiliated teaching hospital.

PATIENTS

Ninety-one consecutive patients were admitted to the TICU during a 6-month period.

MATERIALS AND METHODS

The TICU charges were tracked over two consecutive 3-month periods. The first 3 months served as control. No attempt was made to alter cost of care, and residents were unaware that a study was in progress. During the ensuing 3-month period, attendings explicitly discussed with residents relative costs of diagnostic and therapeutic interventions in an attempt to lower charges. Composition of the surgical trauma team remained constant throughout the study.

MEASUREMENT AND MAIN RESULTS

The median and mean age, Injury Severity Score, intensive care unit length of stay, and sex ratio were not statistically different between the two study groups. Total median daily charges of the postintervention group were reduced over the control group by $818/intensive care unit day (p = 0.0002). The major categories in which charges were reduced included medications ($151/day, p = 0.003), laboratory tests ($120/day, p = 0.072), chest x-ray films ($61/day, p = 0.001), respiratory therapy ($185/day, p = 0.21), and miscellaneous charges ($141/day, p = 0.055). Mortality rates and number of major complications were not statistically different between groups.

CONCLUSIONS

Increased awareness of cost factors and specific attempts to achieve patient cost reduction resulted in a demonstrable decrease in daily TICU charges, without compromising the quality of care.

Attention deficit hyperactivity disorder and whole-blood serotonin levels: effects of comorbidity

Whole-blood serotonin (5-hydroxytryptamine, 5-HT) levels were measured in children with attention deficit hyperactivity disorder (ADHD) with and without comorbid conduct disorder (CD) or oppositional-defiant disorder (ODD). It was hypothesized that the whole-blood 5-HT levels of ADHD probands would be significantly correlated with the whole-blood 5-HT levels of their mothers. Fifty-two children who met DSM-III-R criteria for ADHD were selected consecutively from an ADHD clinic (47 males--35 Caucasians, 10 African-Americans, and 2 Hispanics; 10 females--all Caucasians). Whole-blood 5-HT was assayed by high performance liquid chromatography and compared between ADHD children with and without comorbid CD or ODD. The familiality of whole-blood 5-HT levels was studied by Spearman's rank-order correlation. There were no significant age, race, or sex effects. There was no significant difference in whole-blood 5-HT levels between children with ADHD only (n = 22; 190 +/- 45 ng/ml) and ADHD with CD or ODD (n = 30; 212 +/- 67). However, 7 out of 30 (23%) children with ADHD+CD/ODD had whole-blood 5-HT levels > 270 ng/ml, while none of the ADHD-only children had whole-blood 5-HT levels > 270 ng/ml, a statistically significant difference. Whole-blood 5-HT levels showed significant positive correlations between 36 children with disruptive behavior disorders and their biological mothers (rs = 0.47). There was no difference in mean levels of whole-blood 5-HT between subgroups of children with ADHD with or without comorbid CD or ODD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptive skills dysfunction in ADD and ADHD children

Adaptive functioning was examined in children with Attention Deficit Hyperactivity Disorder (ADHD) or Attention Deficit Disorder (ADD), and a psychiatric comparison group of children with pervasive developmental disorders or mild mental retardation (PDD/MR). As assessed with the Vineland Adaptive Behavior Scales, adaptive functioning was well below average for all three clinic groups. (The PDD/MR group had the lowest adaptive functioning scores, although not statistically different from the other groups). However, the level of adaptive functioning relative to IQ in the areas of Socialization, Communication and Daily Living was significantly lower for the ADD and ADHD groups. These deficits in adaptive functioning that characterize children with ADHD and ADD may help explain the poor long-term prognosis of ADHD, suggesting that increased attention should be paid to the assessment and treatment of adaptive functioning in individuals with ADHD and ADD.

Association of attention-deficit disorder and the dopamine transporter gene

Attention-deficit hyperactivity disorder (ADHD) has been shown to be familial and heritable, in previous studies. As with most psychiatric disorders, examination of pedigrees has not revealed a consistent Mendelian mode of transmission. The response of ADHD patients to medications that inhibit the dopamine transporter, including methylphenidate, amphetamine, pemoline, and bupropion, led us to consider the dopamine transporter as a primary candidate gene for ADHD. To avoid effects of population stratification and to avoid the problem of classification of relatives with other psychiatric disorders as affected or unaffected, we used the haplotype-based haplotype relative risk (HHRR) method to test for association between a VNTR polymorphism at the dopamine transporter locus (DAT1) and DSM-III-R-diagnosed ADHD (N = 49) and undifferentiated attention-deficit disorder (UADD) (N = 8) in trios composed of father, mother, and affected offspring. HHRR analysis revealed significant association between ADHD/UADD and the 480-bp DAT1 allele (chi 2 7.51, 1 df, P = .006). When cases of UADD were dropped from the analysis, similar results were found (Chi 2 7.29, 1 df, P = .007). If these findings are replicated, molecular analysis of the dopamine transporter gene may identify mutations that increase susceptibility to ADHD/UADD. Biochemical analysis of such mutations may lead to development of more effective therapeutic interventions.

Psychometric characteristics of the Wender Utah Rating Scale (WURS): reliability and factor structure for men and women

The goals of this study were to examine the factor structure of the Wender Utah Rating Scale (WURS), to evaluate potential gender differences in factor composition, and to assess the reliability of the scale. The WURS was completed by 310 fathers and 305 mothers of children referred for evaluation of Attention-Deficit Hyperactivity Disorder (ADHD). For males, a five-factor solution (Conduct Problems, Learning Problems, Stress Intolerance, Attention Problems, Poor Social Skills/Awkward) accounted for 72 percent of the variance. There was also a five-factor solution for females (Dysphoria, Impulsive/Conduct, Learning Problems, Attention and Organizational Problems, Unpopular) which accounted for 71 percent of the variance. Symptoms of inattention and impulsivity loaded on separate factors for both men and for women. Test-retest reliability was examined with a different sample of 57 adults who completed the WURS on two separate occasions, 1 month apart. The WURS demonstrated satisfactory internal consistency and temporal stability, and it may be a useful tool for the study of ADHD in adults.

Neurologic and developmental outcome in treated congenital toxoplasmosis

BACKGROUND

Earlier studies have shown that infants with untreated congenital toxoplasmosis and generalized or neurologic abnormalities at presentation almost uniformly develop mental retardation, seizures, and spasticity. Children with untreated subclinical disease at birth have developed seizures, significant cognitive and motor deficits, and diminution in cognitive function over time.

OBJECTIVE

To determine neurologic, cognitive, and motor outcomes for children with congenital toxoplasmosis who were treated for approximately 1 year with pyrimethamine and sulfadiazine.

DESIGN AND METHODS

Systematic, prospective, and longitudinal neurologic, cognitive, and motor evaluations were performed for 36 individuals with congenital toxoplasmosis. These infants were born between December 1981 and January 1991 and were treated with pyrimethamine and sulfadiazine for approximately 1 year beginning in the first months of life. Compliance with medications was documented. These individuals were evaluated in a standardized manner in a single center in the first months of life and at approximately 1, 3.5, 5, 7.5, and 10 years of age. Their cognitive function was compared with the cognitive function of a nearest-age, same-sex sibling when such siblings older than 3.5 years were available for study.

RESULTS

Signs of active central nervous system infection (eg, cerebrospinal fluid [CSF] pleiocytosis, hypoglycorrhachia, elevated CSF protein, and, in some instances, seizures and motor abnormalities) resolved during therapy. Six of the 36 children had perinatal seizures. Four had their anticonvulsant therapy discontinued successfully within the first months of life, and two additional children developed new seizures at 3 and 5 years of age. Tone and motor abnormalities resolved by 1 year of age in 12 of 20 infants who exhibited abnormalities of tone and motor function at their initial neonatal evaluation. By February 1992, 29 of the 36 children had been evaluated when they were 1 year old, and 23 (79%) had a mean +/- standard deviation Mental Developmental Index (MDI) of 102 +/- 22 (range, 59 to 140). Six (21%) had a measure of their cognitive function that was less than 50. Results of sequential IQ tests, performed at 1.5 year intervals or greater, did not differ significantly over time (P > .05). Seven children with MDIs greater than 50 were compared with sibling controls; they had scores of 87 +/- 11 (range, 68 to 97) and their siblings had scores of 112 +/- 15 (range, 85 to 132) (P = .008). Seventeen of 18 children without hydrocephalus and six of eight children with obstructive hydrocephalus responsive to shunting had normal or near-normal neurologic and developmental outcomes. Children with hydrocephalus ex vacuo present at birth, with high CSF protein, and with lack of response to shunting have done less well.

CONCLUSIONS

Neurologic and developmental outcomes were significantly better for most of these treated children than outcomes reported for untreated children or those treated for only 1 month (P < .001). Although the level of cognitive function for treated children was less than for their uninfected siblings (P < .008), there was no significant deterioration in neurologic and cognitive function of the treated children tested sequentially. These favorable treatment outcomes justify systematic identification and treatment of pregnant women with acute gestational Toxoplasma infection and young infants with congenital toxoplasmosis.

Salmonella: now you see it, now you don't

Diseases caused by Salmonella species are characterized by bacterial invasion of host cells. Salmonella invasion requires a genetic locus (inv) with homology to bacterial systems involved in specific protein export and organelle assembly. Until recently, the actual Salmonella invasion factors exported or assembled by the inv system remained unidentified. It now appears that Salmonella produces novel appendages upon contact with host cells. These appendages are transient, appearing and disappearing rapidly from the bacterial surface. Appendages are altered in strains unable to invade due to mutations within the inv/spa locus. Therefore, a role for the invasion locus has been identified, providing another example of bacterial pathogens responding to signals provided by the host cell surface.

Low intelligence but not attention deficit hyperactivity disorder is associated with resistance to thyroid hormone caused by mutation R316H in the thyroid hormone receptor beta gene

Resistance to thyroid hormone (RTH) is a syndrome of reduced responsiveness of tissues to thyroid hormone. The clinical manifestations are variable and 46-50% of children with RTH have attention deficit hyperactivity disorder (ADD). We present a new family with RTH (F120) found to have a mutation R316H in the thyroid hormone receptor beta (TR beta) gene identical for that reported in an unrelated family. Assignment of the mutant allele and haplotyping based on CA repeat polymorphism were done on 16 family members. Semistructured diagnostic interviews and psychometric testing were used to determine the psychiatric diagnosis of 12 family members by examiners blinded to the genotype. Three subjects were identified to have the R316H allele as well as mildly elevated free T4 index (168 +/- 12; normal range 77-135) and nonsuppressed TSH (4.1 +/- 1.7 mU/L). Only 2 of the subjects with RTH were found to have ADD, while one family member homozygous for the wild type TR beta and normal thyroid function tests also had ADD. Unaffected family members had higher full scale intelligence quotients (IQ) (93 +/- 7) than any of the 3 family members with RTH (77 +/- 5, p = 0.006). These data do not support the genetic linkage of ADD and RTH, but do suggest that RTH is associated with lower IQ scores that may confer a high likelihood of exhibiting ADD symptoms.