An App-Based Surveillance System for Undergraduate Students' Mental Health During the COVID-19 Pandemic: Protocol for a Prospective Cohort Study.

BACKGROUND: The COVID-19 pandemic is a public health emergency that poses challenges to the mental health of approximately 1.4 million university students in Canada. Preliminary evidence has shown that the COVID-19 pandemic had a detrimental impact on undergraduate student mental health and well-being; however, existing data are predominantly limited to cross-sectional survey-based studies. Owing to the evolving nature of the pandemic, longer-term prospective surveillance efforts are needed to better anticipate risk and protective factors during a pandemic. OBJECTIVE: The overarching aim of this study is to use a mobile (primarily smartphone-based) surveillance system to identify risk and protective factors for undergraduate students' mental health. Factors will be identified from weekly self-report data (eg, affect and living accommodation) and device sensor data (eg, physical activity and device usage) to prospectively predict self-reported mental health and service utilization. METHODS: Undergraduate students at Western University (London, Ontario, Canada), will be recruited via email to complete an internet-based baseline questionnaire with the option to participate in the study on a weekly basis, using the Student Pandemic Experience (SPE) mobile app for Android/iOS. The app collects sensor samples (eg, GPS coordinates and steps) and self-reported weekly mental health and wellness surveys. Student participants can opt in to link their mobile data with campus-based administrative data capturing health service utilization. Risk and protective factors that predict mental health outcomes are expected to be estimated from (1) cross-sectional associations among students' characteristics (eg, demographics) and key psychosocial factors (eg, affect, stress, and social connection), and behaviors (eg, physical activity and device usage) and (2) longitudinal associations between psychosocial and behavioral factors and campus-based health service utilization. RESULTS: Data collection began November 9, 2020, and will be ongoing through to at least October 31, 2021. Retention from the baseline survey (N=427) to app sign-up was 74% (315/427), with 175-215 (55%-68%) app participants actively responding to weekly surveys. From November 9, 2020, to August 8, 2021, a total of 4851 responses to the app surveys and 25,985 sensor samples (consisting of up to 68 individual data items each; eg, GPS coordinates and steps) were collected from the 315 participants who signed up for the app. CONCLUSIONS: The results of this real-world longitudinal cohort study of undergraduate students' mental health based on questionnaires and mobile sensor metrics is expected to show psychosocial and behavioral patterns associated with both positive and negative mental health-related states during pandemic conditions at a relatively large, public, and residential Canadian university campus. The results can be used to support decision-makers and students during the ongoing COVID-19 pandemic and similar future events. For comparable settings, new interventions (digital or otherwise) might be designed using these findings as an evidence base. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/30504.

Mesophilic microorganisms build terrestrial mats analogous to Precambrian microbial jungles.

Development of Archean paleosols and patterns of Precambrian rock weathering suggest colonization of continents by subaerial microbial mats long before evolution of land plants in the Phanerozoic Eon. Modern analogues for such mats, however, have not been reported, and possible biogeochemical roles of these mats in the past remain largely conceptual. We show that photosynthetic, subaerial microbial mats from Indonesia grow on mafic bedrocks at ambient temperatures and form distinct layers with features similar to Precambrian mats and paleosols. Such subaerial mats could have supported a substantial aerobic biosphere, including nitrification and methanotrophy, and promoted methane emissions and oxidative weathering under ostensibly anoxic Precambrian atmospheres. High C-turnover rates and cell abundances would have made these mats prime locations for early microbial diversification. Growth of landmass in the late Archean to early Proterozoic Eons could have reorganized biogeochemical cycles between land and sea impacting atmospheric chemistry and climate.

Evaluation of a 3D-printed total knee arthroplasty using radiostereometric analysis: assessment of highly porous biological fixation of the tibial baseplate and metal-backed patellar component.

AIMS: Our intention was to investigate if the highly porous biological fixation surfaces of a new 3D-printed total knee arthroplasty (TKA) achieved adequate fixation of the tibial and patellar components to the underlying bone. PATIENTS AND METHODS: A total of 29 patients undergoing primary TKA consented to participate in this prospective cohort study. All patients received a highly porous tibial baseplate and metal-backed patella. Patient-reported outcomes measures were recorded and implant migration was assessed using radiostereometric analysis. RESULTS: Patient function significantly improved by three months postoperatively (p < 0.001). Mean difference in maximum total point motion between 12 and 24 months was 0.021 mm (-0.265 to 0.572) for the tibial implant and 0.089 mm (-0.337 to 0.758) for the patellar implant. The rate of tibial and patellar migration was largest over the first six postoperative weeks, with no changes in mean tibia migration occurring after six months, and no changes in mean patellar migration occurring after six weeks. One patellar component showed a rapid rate of migration between 12 and 24 months. CONCLUSION: Biological fixation appears to occur reliably on the highly porous implant surface of the tibial baseplate and metal-backed patellar component. Rapid migration after 12 months was measured for one patellar component. Further investigation is required to assess the long-term stability of the 3D-printed components and to determine if the high-migrating components achieve fixation. Cite this article: Bone Joint J 2019;101-B(7 Supple C):40-47.

Using the NANA toolkit at home to predict older adults' future depression.

BACKGROUND: Depression is currently underdiagnosed among older adults. As part of the Novel Assessment of Nutrition and Aging (NANA) validation study, 40 older adults self-reported their mood using a touchscreen computer over three, one-week periods. Here, we demonstrate the potential of these data to predict future depression status. METHODS: We analysed data from the NANA validation study using a machine learning approach. We applied the least absolute shrinkage and selection operator with a logistic model to averages of six measures of mood, with depression status according to the Geriatric Depression Scale 10 weeks later as the outcome variable. We tested multiple values of the selection parameter in order to produce a model with low deviance. We used a cross-validation framework to avoid overspecialisation, and receiver operating characteristic (ROC) curve analysis to determine the quality of the fitted model. RESULTS: The model we report contained coefficients for two variables: sadness and tiredness, as well as a constant. The cross-validated area under the ROC curve for this model was 0.88 (CI: 0.69-0.97). LIMITATIONS: While results are based on a small sample, the methodology for the selection of variables appears suitable for the problem at hand, suggesting promise for a wider study and ultimate deployment with older adults at increased risk of depression. CONCLUSIONS: We have identified self-reported scales of sadness and tiredness as sensitive measures which have the potential to predict future depression status in older adults, partially addressing the problem of underdiagnosis.

Long-term health outcomes after exposure to repeated concussion in elite level: rugby union players.

BACKGROUND: There is continuing concern about effects of concussion in athletes, including risk of the neurodegenerative disease chronic traumatic encephalopathy. However, information on long-term health and wellbeing in former athletes is limited. METHOD: Outcome after exposure to repeated brain injury was investigated in 52 retired male Scottish international rugby players (RIRP) and 29 male controls who were similar in age and social deprivation. Assessment included history of playing rugby and traumatic brain injury, general and mental health, life stress, concussion symptoms, cognitive function, disability and markers of chronic stress (allostatic load). RESULTS: The estimated number of concussions in RIRP averaged 14 (median=7; IQR 5-40). Performance was poorer in RIRP than controls on a test of verbal learning (p=0.022) and of fine co-ordination of the dominant hand (p=0.038) and not significantly different on other cognitive tests (p>0.05). There were no significant associations between number of concussions and performance on cognitive tests. Other than a higher incidence of cardiovascular disease in controls, no group differences were detected in general or mental health or estimates of allostatic load. In RIRP, persisting symptoms attributed to concussion were more common if reporting more than nine concussions (p=0.028), although these symptoms were not perceived to affect social or work functioning. CONCLUSIONS: Despite a high number of concussions in RIRP, differences in mental health, social or work functioning were not found late after injury. Subtle group differences were detected on two cognitive tests, the cause of which is uncertain. Prospective group comparison studies on representative cohorts are required.

Validation of the NANA (Novel Assessment of Nutrition and Ageing) touch screen system for use at home by older adults.

Prospective measurement of nutrition, cognition, and physical activity in later life would facilitate early detection of detrimental change and early intervention but is hard to achieve in community settings. Technology can simplify the task and facilitate daily data collection. The Novel Assessment of Nutrition and Ageing (NANA) toolkit was developed to provide a holistic picture of an individual's function including diet, cognition and activity levels. This study aimed to validate the NANA toolkit for data collection in the community. Forty participants aged 65 years and over trialled the NANA toolkit in their homes for three 7-day periods at four-week intervals. Data collected using the NANA toolkit were compared with standard measures of diet (four-day food diary), cognitive ability (processing speed) and physical activity (self-report). Bland-Altman analysis of dietary intake (energy, carbohydrates, protein fat) found a good relationship with the food diary and cognitive processing speed and physical activity (hours) were significantly correlated with their standard counterparts. The NANA toolkit enables daily reporting of data that would otherwise be collected sporadically while reducing demands on participants; older adults can complete the daily reporting at home without a researcher being present; and it enables prospective investigation of several domains at once.

Imaging African trypanosomes.

Trypanosoma brucei are extracellular kinetoplastid parasites transmitted by the blood-sucking tsetse fly. They are responsible for the fatal disease human African trypanosomiasis (HAT), also known as sleeping sickness. In late-stage infection, trypanosomes cross the blood-brain barrier (BBB) and invade the central nervous system (CNS) invariably leading to coma and death if untreated. There is no available vaccine and current late-stage HAT chemotherapy consists of either melarsoprol, which is highly toxic causing up to 8% of deaths, or nifurtimox-eflornithine combination therapy (NECT), which is costly and difficult to administer. There is therefore an urgent need to identify new late-stage HAT drug candidates. Here, we review how current imaging tools, ranging from fluorescent confocal microscopy of live immobilized cells in culture to whole-animal imaging, are providing insight into T. brucei biology, parasite-host interplay, trypanosome CNS invasion and disease progression. We also consider how imaging tools can be used for candidate drug screening purposes that could lead to new chemotherapies.

Second brain death examination may negatively affect organ donation.

BACKGROUND: Little is known about the impact of the requirement for a second brain death examination on organ donation. In New York State, 2 examinations 6 hours apart have been recommended by a Department of Health panel. METHODS: We reviewed data for 1,229 adult and 82 pediatric patients pronounced brain dead in 100 New York hospitals serviced by the New York Organ Donor Network from June 1, 2007, to December 31, 2009. We reviewed the time interval between the 2 clinical brain death examinations and correlated this brain death declaration interval to day of the week, hospital size, and organ donation. RESULTS: None of the patients declared brain dead were found to regain brainstem function upon repeat examination. The mean brain death declaration interval between the 2 examinations was 19.2 hours. A 26% reduction in brain death examination frequency was seen on weekends when compared to weekdays (p = 0.0018). The mean brain death interval was 19.9 hours for 0-750 bed hospitals compared to 16.0 hours for hospitals with more than 750 beds (p = 0.0015). Consent for organ donation decreased from 57% to 45% as the brain death declaration interval increased. Conversely, refusal of organ donation increased from 23% to 36% as the brain death interval increased. A total of 166 patients (12%) sustained a cardiac arrest between the 2 examinations or after the second examination. CONCLUSION: A single brain death examination to determine brain death for patients older than 1 year should suffice. In practice, observation time to a second neurologic examination was 3 times longer than the proposed guideline and associated with substantial intensive care unit costs and loss of viable organs.

A high-resolution chemical and structural study of framboidal pyrite formed within a low-temperature bacterial biofilm.

A novel, anaerobically grown microbial biofilm, scraped from the inner surface of a borehole, 1474 m below land surface within a South African, Witwatersrand gold mine, contains framboidal pyrite. Water flowing from the borehole had a temperature of 30.9 degrees C, a pH of 7.4, and an Eh of -50 mV. Examination of the biofilm using X-ray diffraction, field emission gun scanning electron microscope equipped for energy dispersive X-ray microanalysis demonstrated that the framboids formed within a matrix of bacteria and biopolymers. Focused ion beam sectioning of framboids followed by NEXAFS measurements using both scanning transmission X-ray microscopy and X-ray photoelectron emission microscopy revealed that the pyrite crystals grew within an organic carbon matrix consisting of exopolysaccharides and possibly extracellular DNA, which is intuitively important in sulfide mineral diagenesis. Growth of individual pyrite crystals within the framboid occurred inside organic templates confirms the association between framboidal pyrite and organic materials in low-temperature diagenetic environments and the important role of microenvironments in biofilms in regulating geochemical cycles.

Structural characterization and serological specificities of lipopolysaccharides from Salmonella enterica serovar Gallinarum biovar Pullorum standard, intermediate and variant antigenic type strains.

The structure and serological specificities of the lipopolysaccharides (LPSs) from Salmonella enterica serovar Gallinarum biovar Pullorum were studied to provide an improved basis for the distinction between antigenic types and the development of improved diagnostic tests. The structure of the LPS O-polysaccharide (O-PS) from S. Pullorum standard, intermediate and variant antigenic type strains was determined by mass spectrometry, nuclear magnetic resonance spectroscopy and chemical analysis. The LPS of the three strains shared a common structural repeating oligosaccharide unit containing d-mannose, l-rhamnose, d-galactose and d-tyvelose (1:1:1:1). The O-PS of the variant type LPS contained an additional d-glucose residue linked to the O-4 position of the d-galactose residue. The O-PS of the intermediate type LPS was partially the same as that of the variant LPS, however, the molar ratio of the d-glucose component was lower with respect to the other glycose components. Serological specificities of the three antigenic type LPSs were examined with anti-S. Pullorum LPS monoclonal antibodies (Mabs). On immunoblots, Mabs to the standard type O-PS reacted with high molecular mass (HMM) and low molecular mass (LMM) LPS from the standard strain, and with LMM but not HMM LPS from the variant strain. Monoclonal antibodies to the variant type O-PS reacted with HMM but not LMM LPS from the variant strain, and did not react with HMM or LMM LPS from the standard strain. On ELISA, the standard, intermediate and variant antigenic type strains were differentiated by the relative reactivity with the anti-LPS O-PS Mabs. Several of the anti-LPS O-PS Mabs were specific for S. Pullorum and other serogroup D1 Salmonella, and are potentially useful for the development of improved diagnostic tests for these organisms.

"Bounce at the Bell": a novel program of short bouts of exercise improves proximal femur bone mass in early pubertal children.

OBJECTIVES: To examine the effects of a simple and inexpensive physical activity intervention on change in bone mass and structure in school aged children. METHODS: Fifty one children (n = 23 boys and 28 girls; mean age 10.1 years) participated in "Bounce at the Bell" which consisted of 10 counter-movement jumps 3x per day (total approximately 3 min/day). Controls were 71 matched children who followed usual school practice. We assessed dietary calcium, physical activity, physical performance, and anthropometry in September and after 8 months of intervention (June). We measured bone mineral content (BMC) and bone area at the lumbar spine, total body, and proximal femur. Proximal femur scans were also analysed for bone geometry and structural strength using the hip structural analysis program. Lean and fat mass (g) were also calculated. RESULTS: Groups were similar at baseline and did not differ in weight, height, total body, lumbar spine, proximal femur, or femoral neck BMC. Control children had a greater increase in adjusted total body BMC (1.4%). Intervention children gained significantly more BMC at the total proximal femur (2%) and the intertrochanteric region (27%). Change in bone structural parameters did not differ between groups. CONCLUSIONS: This novel, easily implemented exercise program, took only a few minutes each day and enhanced bone mass at the weight bearing proximal femur in early pubertal children. A large, randomised study of boys and girls should be undertaken powered to test the effectiveness of Bounce at the Bell in children at different stages of maturity, and in boys and girls independently.

Are ultrasound and magnetic resonance imaging of value in assessment of Achilles tendon disorders? A two year prospective study.

OBJECTIVES: To (a) compare ultrasound (US; including grey scale and colour and power Doppler) and magnetic resonance imaging (MRI; with high resolution and fat saturation sequences) with a clinical yardstick in the evaluation of chronic Achilles tendinopathy, and (b) examine whether either imaging method predicted 12 and 24 month clinical outcome. METHODS: Forty five patients with symptoms in 57 Achilles tendons were diagnosed with tendinopathy by an experienced sports medicine doctor. All patients underwent US examination (12 MHz probe) with colour and power Doppler, and 25 consecutive patients also underwent MRI with high resolution T1 weighted and STIR sequences. RESULTS: US identified abnormal morphology in 37 of the 57 symptomatic tendons (65%) and normal morphology in 19 of 28 asymptomatic tendons (68%). Baseline US findings did not predict 12 month clinical outcome. The addition of colour and power Doppler did not improve the diagnostic performance of US. MRI identified abnormal morphology in 19 of 34 symptomatic tendons (56%) and normal morphology in 15 of 16 asymptomatic tendons (94%). Lesser grades of MR signal abnormality at baseline were associated with better clinical status at 12 month follow up. CONCLUSIONS: US and MRI show only moderate correlation with clinical assessment of chronic Achilles tendinopathy. Graded MRI appearance was associated with clinical outcome but US was not.

Structural studies on the O-polysaccharide of the lipopolysaccharide produced by Citrobacter rodentium (ATCC 51459).

Citrobacter rodentium is the etiologic agent of transmissible murine colonic hyperplasia (TMCH) and is the only Citrobacter species known to possess virulence factors homologous to human enteropathogenic and enterohemorrhagic Escherichia coli. Members of this species are considered clonal and represent the only known attaching and effacing bacterial pathogen of mice and thus provides a useful animal model for studying the molecular basis of attaching and effacing pathology. The lipopolysaccharide (LPS) produced by C. rodentium has not been previously studied or its possible role as a virulence factor determined. The structure of the LPS has been undertaken as a first step in an investigation of its possible role in pathogenesis. The structure of C. rodentium (ATCC 51459, prototype TMCH isolate, original biotype 4280, previously designated DBS 100) LPS was determined from composition and methylation analyses, mass spectrometry, and two-dimensional nuclear magnetic resonance spectroscopy. The antigenic O-polysaccharide was found to be a high molecular mass branched polymer of repeating pentasaccharide units composed of 2-acetamido-2-deoxy-D-glucose (D-GlcNAc), d-glucose (D-Glc), and L-rhamnose (L-Rha) in the molar ratio 2 : 2 : 1 linked through phosphate, and has the structure: [structure: see text]

Resource absorption in a health service system.

This paper considers the use of treatment resources in a health service system. The particular aspect of system use which is identified is resource absorption - excessive use by a small subset of users and unmet need by others. A dynamic stochastic model for health status with treatment interventions is formulated and the distribution of accumulated treatment time (service) is developed. The characterization of heavy tails in the distribution, the essential feature of resource absorption, is based on the Lorenz curve and an Index of Resource Absorption is defined for any feasible Lorenz curve. The index is applied to the use of psychiatric hospital resources in a Province of Canada.

Nitric oxide and cytokine synthesis in human African trypanosomiasis.

Plasma and cerebrospinal fluid (CSF) concentrations of nitrate and the cytokines interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, interleukin (IL)-10, and IL-4 were measured in 91 African trypanosomiasis patients before and after treatment. Nitrate levels overall were not significantly elevated over those for control persons, but a marginal increase in plasma nitrate was detected in patients reporting illness of <40 days' duration. Plasma IFN-gamma and total TNF-alpha concentrations increased during infection, but free TNF-alpha levels were low in all patients. The most dramatic cytokine response was for IL-10, which was significantly elevated in both plasma and CSF during infection but returned to control levels after treatment. The results indicate that human African trypanosomiasis leads to the development of a strong anti-inflammatory cytokine response.

Structural and genetic analyses of O polysaccharide from Actinobacillus actinomycetemcomitans serotype f.

The oral bacterium Actinobacillus actinomycetemcomitans is implicated as a causative agent of localized juvenile periodontitis (LJP). A. actinomycetemcomitans is classified into five serotypes (a to e) corresponding to five structurally and antigenically distinct O polysaccharide (O-PS) components of their respective lipopolysaccharide molecules. Serotype b has been reported to be the dominant serotype isolated from LJP patients. We determined the lipopolysaccharide O-PS structure from A. actinomycetemcomitans CU1000, a strain isolated from a 13-year-old African-American female with LJP which had previously been classified as serotype b. The O-PS of strain CU1000 consisted of a trisaccharide repeating unit composed of L-rhamnose and 2-acetamido-2-deoxy-D-galactose (molar ratio, 2:1) with the structure -->2)-alpha-L-Rhap-(1-3)-2-O-(beta-D-GalpNAc)-alpha-L-Rhap-(1-->* O-PS from strain CU1000 was structurally and antigenically distinct from the O-PS molecules of the five known A. actinomycetemcomitans serotypes. Strain CU1000 was mutagenized with transposon IS903phikan, and three mutants that were deficient in O-PS synthesis were isolated. All three transposon insertions mapped to a single 1-kb region on the chromosome. The DNA sequence of a 13.1-kb region surrounding these transposon insertions contained a cluster of 14 open reading frames that was homologous to gene clusters responsible for the synthesis of A. actinomycetemcomitans serotype b, c, and e O-PS antigens. The CU1000 gene cluster contained two genes that were not present in serotype-specific O-PS antigen clusters of the other five known A. actinomycetemcomitans serotypes. These data indicate that strain CU1000 should be assigned to a new A. actinomycetemcomitans serotype, designated serotype f. A PCR assay using serotype-specific PCR primers showed that 3 out of 20 LJP patients surveyed (15%) harbored A. actinomycetemcomitans strains carrying the serotype f gene cluster. The finding of an A. actinomycetemcomitans serotype showing serological cross-reactivity with anti-serotype b-specific antiserum suggests that a reevaluation of strains previously classified as serotype b may be warranted.

Once-a-day Concerta methylphenidate versus three-times-daily methylphenidate in laboratory and natural settings.

OBJECTIVE: Methylphenidate (MPH), the most commonly prescribed drug for attention-deficit/hyperactivity disorder (ADHD), has a short half-life, which necessitates multiple daily doses. The need for multiple doses produces problems with medication administration during school and after-school hours, and therefore with compliance. Previous long-acting stimulants and preparations have shown effects equivalent to twice-daily dosing of MPH. This study tests the efficacy and duration of action, in natural and laboratory settings, of an extended-release MPH preparation designed to last 12 hours and therefore be equivalent to 3-times-daily dosing. METHODS: Sixty-eight children with ADHD, 6 to 12 years old, participated in a within-subject, double-blind comparison of placebo, immediate-release (IR) MPH 3 times a day (tid), and Concerta, a once-daily MPH formulation. Three dosing levels of medication were used: 5 mg IR MPH tid/18 mg Concerta once a day (qd); 10 mg IR MPH tid/36 mg Concerta qd; and 15 mg IR MPH tid/54 mg Concerta qd. All children were currently medicated with MPH at enrollment, and each child's dose level was based on that child's MPH dosing before the study. The doses of Concerta were selected to be comparable to the daily doses of MPH that each child received. To achieve the ascending rate of MPH delivery determined by initial investigations to provide the necessary continuous coverage, Concerta doses were 20% higher on a daily basis than a comparable tid regimen of IR MPH. Children received each medication condition for 7 days. The investigation was conducted in the context of a background clinical behavioral intervention in both the natural environment and the laboratory setting. Parents received behavioral parent training and teachers were taught to establish a school-home daily report card (DRC). A DRC is a list of individual target behaviors that represent a child's most salient areas of impairment. Teachers set daily goals for each child's impairment targets, and parents provided rewards at home for goal attainment. Each weekday, teachers completed the DRC, and it was used as a dependent measure of individualized medication response. Teachers and parents also completed weekly standardized ratings of behavior and treatment effectiveness. To evaluate the time course of medication effects, children spent 12 hours in a laboratory setting on Saturdays and medication effects were measured using procedures and methods adapted from our summer treatment program. Measures of classroom behavior and academic productivity/accuracy were taken in a laboratory classroom setting during which children completed independent math and reading worksheets. Measures of social behavior were taken in structured, small-group board game settings and unstructured recess settings. Measures included behavior frequency counts, academic problems completed and accuracy, independent observations, teacher and counselor ratings, and individualized behavioral target goals. Reports of adverse events, sleep quality, and appetite were collected. RESULTS: On virtually all measures in all settings, both drug conditions were significantly different from placebo, and the 2 drugs were not different from each other. In children's regular school settings, both medications improved behavior as measured by teacher ratings and individualized target behaviors (the DRC); these effects were seen into the evening as measured by parent ratings. In the laboratory setting, effects of Concerta were equivalent to tid MPH and lasted at least through 12 hours after dosing. Concerta was significantly superior to tid MPH on 2 parent rating scores, and when asked, more parents preferred Concerta than preferred tid IR MPH or placebo. Side effects on children's sleep and appetite were similar for the 2 preparations. In the lab setting, both medications improved productivity and accuracy on arithmetic seatwork assignments, disruptive and on-task behavior, and classroom rule following. Both medications improved children's rule following and negative behavior in small group board games, as well as in unstructured recess settings. Individual target behaviors also showed significant improvement with medication across domains in the laboratory setting. Children's behavior across settings deteriorated across the laboratory day, and the primary effect of medication was to prevent this deterioration as the day wore on. Results support the use of background behavioral treatment in clinical trials of stimulant medication, and illustrate the utility of a measure of individualized daily target goals (ie, the DRC) as an objective measure of medication response in both the laboratory and natural school settings. CONCLUSION: This investigation clearly supports the efficacy of the Concerta long-acting formulation of MPH for parents who desire to have medication benefits for their child throughout the day and early evening. (ABSTRACT TRUNCATED)

The structure of the lipopolysaccharide O-antigen produced by Flavobacterium psychrophilum (259-93).

Flavobacterium psychrophilum, a Gram-negative bacterium, is the etiological agent of rainbow trout fry syndrome and bacterial cold water disease, septicemic infections in reared salmonids. In humans Flavobacterium spp. have been associated with neonatal meningitis and septicemia, catheter-associated bacteremia, and pneumonia. Recently, several F. psychrophilum surface molecules, including lipopolysaccharide (LPS), have been implicated in its pathogenesis and identified as potential vaccine and diagnostic candidate macromolecules. Studies on the LPS produced by the bacterium are reported herein. The structure of the antigenic O-polysaccharide contained in the LPS of F. psychrophilum was deduced by the application of analytical NMR spectroscopy, mass spectrometry, glycose and methylation analysis, and partial hydrolysis degradations, and was found to be an unbranched polymer of trisaccharide repeating units composed of L-rhamnose (L-Rhap), 2-acetamido-2-deoxy-L-fucose (L-FucpNAc) and 2-acetamido-4-((3S,5S)-3,5-dihydroxyhexanamido)-2,4-dideoxy-D-quinovose (D-Quip2NAc4NR, 2-N-acetyl-4-N-((3S,5S)-3,5-dihydroxyhexanoyl)-D-bacillosamine) (1 : 1 : 1) and having the structure: -->4)-alpha-L-FucpNAc-(1-->3)-alpha-D-Quip2NAc4NR-(1-->2)- alpha-L-Rhap-(1--> where R is (3S,5S)-CH3CH(OH)CH2CH(OH)CH2CO-.

Long- or short-limb gastric bypass?

The aim of this study was to determine whether longer limb length improved results of gastric bypass in patients who were morbidly obese (body mass index <50 kg/m(2)) or superobese (body mass index >50 kg/m(2). A total of 242 patients were followed for a mean of 5.5 years. The standard operation was a Roux-en-Y gastric bypass with a 40 cm Roux limb and a 10 cm afferent limb. The long-limb operation had a 100 cm Roux limb and a 100 cm afferent limb. Morbidly obese patients did not benefit from a long-limb bypass. The final body mass index was 28.6 +/- 4.7 kg/m(2) in the short-limb group and 28.5 +/- 3.8 kg/m(2) in the long-limb group. The superobese patients did benefit from a long-limb bypass. Final body mass index was 35.8 +/- 6.7 kg/m(2) in the short-limb patients and 32.7 +/- 5.1 in the long-limb patients (P = 0.049). A subgroup of 20 patients, all of whom had a body mass index greater than 60 kg/m(2), benefited the most from long-limb bypass. No macronutritional side effects unique to the long-limb bypass were encountered.