A novel, high-performance, low-volume, rapid luciferase immunoprecipitation system (LIPS) assay to detect autoantibodies to zinc transporter 8

BACKGROUND

Zinc transporter 8 autoantibodies (ZnT8A) are thought to appear close to type 1 diabetes (T1D) onset and can identify high-risk multiple (≥2) autoantibody positive individuals. Radiobinding assays (RBA) are widely used for ZnT8A measurement but have limited sustainability. We sought to develop a novel, high-performance, non-radioactive luciferase immunoprecipitation system (LIPS) assay to replace RBA.

METHODS

A custom dual C-terminal ZnT8 (aa268-369; R325/W325) heterodimeric antigen, tagged with a NanoluciferaseTM (Nluc-ZnT8) reporter, and LIPS assay was developed. Assay performance was evaluated by testing sera from new onset T1D (n = 573), healthy schoolchildren (n = 521), and selected first-degree relatives (FDRs) from the Bart's Oxford family study (n = 617; 164 progressed to diabetes).

RESULTS

In new-onset T1D, ZnT8A levels by LIPS strongly correlated with RBA (Spearman's r = 0.89; P < 0.0001), and positivity was highly concordant (94.3%). At a high specificity (95%), LIPS and RBA had comparable assay performance [LIPS pROC-AUC(95) 0.032 (95% CI: 0.029-0.036); RBA pROC-AUC(95) 0.031 (95% CI: 0.028-0.034); P = 0.376]. Overall, FDRs found positive by LIPS or RBA had a comparable 20-year diabetes risk (52.6% and 59.7%, respectively), but LIPS positivity further stratified T1D risk in FDRs positive for at least one other islet autoantibody detected by RBA (P = 0.0346).

CONCLUSION

This novel, high-performance, cheaper, quicker, higher throughput, low blood volume Nluc-ZnT8 LIPS assay is a safe, non-radioactive alternative to RBA with enhanced sensitivity and ability to discriminate T1D progressors. This method offers an advanced approach to current strategies to screen the general population for T1D risk for immunotherapy trials and to reduce rates of diabetic ketoacidosis at diagnosis.

Transdermal Blood Sampling for C-Peptide Is a Minimally Invasive, Reliable Alternative to Venous Sampling in Children and Adults With Type 1 Diabetes

OBJECTIVE

C-peptide and islet autoantibodies are key type 1 diabetes biomarkers, typically requiring venous sampling, which limits their utility. We assessed transdermal capillary blood (TCB) collection as a practical alternative.

RESEARCH DESIGN AND METHODS

Ninety-one individuals (71 with type 1 diabetes, 20 control; individuals with type 1 diabetes: aged median 14.8 years [interquartile range (IQR) 9.1-17.1], diabetes duration 4.0 years [1.5-7.7]; control individuals: 42.2 years [38.0-52.1]) underwent contemporaneous venous and TCB sampling for measurement of plasma C-peptide. Participants with type 1 diabetes also provided venous serum and plasma, and TCB plasma for measurement of autoantibodies to glutamate decarboxylase, islet antigen-2, and zinc transporter 8. The ability of TCB plasma to detect significant endogenous insulin secretion (venous C-peptide ≥200 pmol/L) was compared along with agreement in levels, using Bland-Altman. Venous serum was compared with venous and TCB plasma for detection of autoantibodies, using established thresholds. Acceptability was assessed by age-appropriate questionnaire.

RESULTS

Transdermal sampling took a mean of 2.35 min (SD 1.49). Median sample volume was 50 µL (IQR 40-50) with 3 of 91 (3.3%) failures, and 13 of 88 (14.7%) <35 µL. TCB C-peptide showed good agreement with venous plasma (mean venous ln[C-peptide] - TCB ln[C-peptide] = 0.008, 95% CI [-0.23, 0.29], with 100% [36 of 36] sensitivity/100% [50 of 50] specificity to detect venous C-peptide ≥200 pmol/L). Where venous serum in multiple autoantibody positive TCB plasma agreed in 22 of 32 (sensitivity 69%), comparative specificity was 35 of 36 (97%). TCB was preferred to venous sampling (type 1 diabetes: 63% vs. 7%; 30% undecided).

CONCLUSIONS

Transdermal capillary testing for C-peptide is a sensitive, specific, and acceptable alternative to venous sampling; TCB sampling for islet autoantibodies needs further assessment.

Resolution of dysglycaemia after treatment of monoclonal gammopathy of endocrine significance

In very rare cases of monoclonal gammopathy, insulin-binding paraprotein can cause disabling hypoglycaemia. We report a 67-year-old man re-evaluated for hyperinsulinaemic hypoglycaemia that persisted despite distal pancreatectomy. He had no medical history of diabetes mellitus or autoimmune disease but was being monitored for an IgG kappa monoclonal gammopathy of undetermined significance. On glucose tolerance testing, hyperglycaemia occurred at 60 min (glucose 216 mg/dL) and hypoglycaemia at 300 min (52 mg/dL) concurrent with an apparent plasma insulin concentration of 52 850 pmol/L on immunoassay. Laboratory investigation revealed an IgG2 kappa with very high binding capacity but low affinity (Kd 1.43 × 10-6 mol/L) for insulin. The monoclonal gammopathy was restaged as smouldering myeloma not warranting plasma cell-directed therapy from a haematological standpoint. Plasma exchange reduced paraprotein levels and improved fasting capillary glucose concentrations. Lenalidomide was used to treat disabling hypoglycaemia, successfully depleting paraprotein and leading to resolution of symptoms.

The measurement of autoantibodies to insulin informs diagnosis of diabetes in a childhood population negative for other autoantibodies

AIMS

Some childhood type 1 diabetes cases are islet autoantibody negative at diagnosis. Potential explanations include misdiagnosis of genetic forms of diabetes or insufficient islet autoantibody testing. Many NHS laboratories offer combinations of three autoantibody markers. We sought to determine the benefit of testing for additional islet autoantibodies, including insulin (IAA) and tetraspanin 7 (TSPAN7A).

METHODS

Radiobinding assays (RBAs) were used to test for four islet autoantibodies in children with newly diagnosed type 1 diabetes (n = 486; 54.1% male; median age 10.4 years [range 0.7-18.0]; median duration 1 day [range -183 to 14]). Islet autoantibody negative children were tested for TSPAN7A using a luminescence-based test. Where available, islet cell antibody (ICA) and human leucocyte antigen (HLA) data were considered.

RESULTS

Using three autoantibody markers, 21/486 (4.3%) children were autoantibody negative. Testing for IAA classified a further 9/21 (42.9%) children as autoantibody positive. Of the remaining 12 (2.5%) autoantibody negative children, all were TPAN7A negative, seven were ICA negative and one was positive for the protective variant DQB1*0602. One was subsequently diagnosed with Maturity Onset of Diabetes in the Young, but follow-up was not available in all cases.

CONCLUSIONS

Using highly sensitive assays, testing for three autoantibodies fails to detect islet autoimmunity in approximately 1/20 children diagnosed with type 1 diabetes. Testing for IAA in children <5 years and GADA in those >10 years was the most effective strategy for detecting islet autoimmunity. The ability to test for all islet autoantibodies should inform clinical decisions and make screening for monogenic diabetes more cost-effective.

The longitudinal loss of islet autoantibody responses from diagnosis of type 1 diabetes occurs progressively over follow-up and is determined by low autoantibody titres, early-onset, and genetic variants

The clinical usefulness of post-diagnosis islet autoantibody levels is unclear and factors that drive autoantibody persistence are poorly defined in type 1 diabetes (T1D). Our aim was to characterise the longitudinal loss of islet autoantibody responses after diagnosis in a large, prospectively sampled UK cohort. Participants with T1D [n = 577] providing a diagnosis sample [range -1.0 to 2.0 years] and at least one post-diagnosis sample (<32.0 years) were tested for autoantibodies to glutamate decarboxylase 65 (GADA), islet antigen-2 (IA-2A), and zinc transporter 8 (ZnT8A). Select HLA and non-HLA SNPs were considered. Non-genetic and genetic factors were assessed by multivariable logistic regression models for autoantibody positivity at initial sampling and autoantibody loss at final sampling. For GADA, IA-2A, and ZnT8A, 70.8%, 76.8%, and 40.1%, respectively, remained positive at the final sampling. Non-genetic predictors of autoantibody loss were low baseline autoantibody titres (P < 0.0001), longer diabetes duration (P < 0.0001), and age-at-onset under 8 years (P < 0.01--0.05). Adjusting for non-genetic covariates, GADA loss was associated with low-risk HLA class II genotypes (P = 0.005), and SNPs associated with autoimmunity RELA/11q13 (P = 0.017), LPP/3q28 (P = 0.004), and negatively with IFIH1/2q24 (P = 0.018). IA-2A loss was not associated with genetic factors independent of other covariates, while ZnT8A loss was associated with the presence of HLA A*24 (P = 0.019) and weakly negatively with RELA/11q13 (P = 0.049). The largest longitudinal study of islet autoantibody responses from diagnosis of T1D shows that autoantibody loss is heterogeneous and influenced by low titres at onset, longer duration, earlier age-at-onset, and genetic variants. These data may inform clinical trials where post-diagnosis participants are recruited.

Persistence of islet autoantibodies after diagnosis in type 1 diabetes

The presence of islet autoantibodies remains a reliable biomarker to identify individuals at high risk of developing type 1 diabetes. As such, these autoantibodies play a pivotal role in understanding the prodrome of diabetes and selecting individuals for both prevention and intervention clinical trials. Over the last few decades, studies have sought to investigate autoantibody prevalence after diabetes onset to better understand ongoing islet autoimmunity; however, many findings are contradictory, and little is known about factors that may influence autoantibody persistence. Generally, glutamate decarboxylase autoantibodies (GADAs) are the most prevalent autoantibodies after diagnosis, particularly in adults, whilst zinc transporter 8 autoantibodies (ZnT8A) prevalence declines more rapidly. However, when studies with islet autoantibody data at diagnosis are considered, it becomes clear that overall islet antigen-2 autoantibodies (IA-2A) tend to persist for longer than GADA or ZnT8A. In this review, we assess the major studies that have contributed to our understanding of autoantibody persistence after diabetes onset and what factors affect this. Islet autoantibodies may provide biomarkers for long-term β-cell function and insights into how to prevent ongoing islet autoimmunity but larger studies collecting samples at and decades after diabetes onset are required to leverage the information they could provide.

What has zinc transporter 8 autoimmunity taught us about type 1 diabetes?

Zinc transporter 8 (ZnT8), a protein highly specific to pancreatic insulin-producing beta cells, is vital for the biosynthesis and secretion of insulin. ZnT8 autoantibodies (ZnT8A) are among the most recently discovered and least-characterised islet autoantibodies. In combination with autoantibodies to several other islet antigens, including insulin, ZnT8A help predict risk of future type 1 diabetes. Often, ZnT8A appear later in the pathogenic process leading to type 1 diabetes, suggesting that the antigen is recognised as part of the spreading, rather than the initial, autoimmune response. The development of autoantibodies to different forms of ZnT8 depends on the genotype of an individual for a polymorphic ZnT8 residue. This genetic variant is associated with susceptibility to type 2 but not type 1 diabetes. Levels of ZnT8A often fall rapidly after diagnosis while other islet autoantibodies can persist for many years. In this review, we consider the contribution made by ZnT8 to our understanding of type 1 diabetes over the past decade and what remains to be investigated in future research.

Continuous generation of volumetric images during stereotactic body radiation therapy using periodic kV imaging and an external respiratory surrogate

We present a technique for continuous generation of volumetric images during SBRT using periodic kV imaging and an external respiratory surrogate signal to drive a patient-specific PCA motion model. Using the on-board imager, kV radiographs are acquired every 3 s and used to fit the parameters of a motion model so that it matches observed changes in internal patient anatomy. A multi-dimensional correlation model is established between the motion model parameters and the external surrogate position and velocity, enabling volumetric image reconstruction between kV imaging time points. Performance of the algorithm was evaluated using 10 realistic eXtended CArdiac-Torso (XCAT) digital phantoms including 3D anatomical respiratory deformation programmed with 3D tumor positions measured with orthogonal kV imaging of implanted fiducial gold markers. The clinically measured ground truth 3D tumor positions provided a dataset with realistic breathing irregularities, and the combination of periodic on-board kV imaging with recorded external respiratory surrogate signal was used for correlation modeling to account for any changes in internal-external correlation. The three-dimensional tumor positions are reconstructed with an average root mean square error (RMSE) of 1.47 mm, and an average 95th percentile 3D positional error of 2.80 mm compared with the clinically measured ground truth 3D tumor positions. This technique enables continuous 3D anatomical image generation based on periodic kV imaging of internal anatomy without the additional dose of continuous kV imaging. The 3D anatomical images produced using this method can be used for treatment verification and delivered dose computation in the presence of irregular respiratory motion.

Cancer risk in children born after donor ART

STUDY QUESTION

Do children born after donor ART have an increased risk of developing childhood cancer in comparison to the general population?

SUMMARY ANSWER

This study showed no overall increased risk of childhood cancer in individuals born after donor ART.

WHAT IS KNOWN ALREADY

Most large population-based studies have shown no increase in overall childhood cancer incidence after non-donor ART; however, other studies have suggested small increased risks in specific cancer types, including haematological cancers. Cancer risk specifically in children born after donor ART has not been investigated to date.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study utilized record linkage to determine the outcome status of all children born in Great Britain (1992-2008) after donor ART. The cohort included 12 137 members who contributed 95 389 person-years of follow-up (average follow-up 7.86 years).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Records of all children born in Great Britain (England, Wales, Scotland) after all forms of donor ART (1992-2008) were linked to the UK National Registry of Childhood Tumours (NRCT) to determine the number who subsequently developed cancer by 15 years of age, by the end of 2008. Rates of overall and type specific cancer (selected a priori) were compared with age, sex and calendar year standardized population-based rates, stratifying for potential mediating/moderating factors including sex, age at diagnosis, birth weight, multiple births, maternal previous live births, assisted conception type and fresh/ cryopreserved cycles.

MAIN RESULTS AND THE ROLE OF CHANCE

In our cohort of 12 137 children born after donor ART (52% male, 55% singleton births), no overall increased risk of cancer was identified. There were 12 cancers detected compared to 14.4 expected (standardized incidence ratio (SIR) 0.83; 95% CI 0.43-1.45; P = 0.50). A small, significant increased risk of hepatoblastoma was found, but the numbers and absolute risks were small (<5 cases observed; SIR 10.28; 95% CI 1.25-37.14; P < 0.05). This increased hepatoblastoma risk was associated with low birthweight.

LIMITATIONS REASONS FOR CAUTION

Although this study includes a large number of children born after donor ART, the rarity of specific diagnostic subgroups of childhood cancer results in few cases and therefore wide CIs for such outcomes. As this is an observational study, it is not possible to adjust for all potential confounders; we have instead used stratification to explore potential moderating and mediating factors, where data were available.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first study to investigate cancer risk in children born after donor ART. Although based on small numbers, results are reassuring for families and clinicians. The small but significant increased risk of hepatoblastoma detected was associated with low birthweight, a known risk factor for this tumour type. It should be emphasized that the absolute risks are very small. However, on-going investigation with a longer follow-up is needed.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by Cancer Research UK (C36038/A12535) and the National Institute for Health Research (405526) and supported by the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children NHS Foundation Trust and University College London. The work of the Childhood Cancer Research Group (CCRG) was supported by the charity CHILDREN with CANCER UK, the National Cancer Intelligence Network, the Scottish Government and the Department of Health for England and Wales. There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Assessment and Management of Anti-Insulin Autoantibodies in Varying Presentations of Insulin Autoimmune Syndrome

Context

Insulin autoimmune syndrome (IAS), spontaneous hyperinsulinemic hypoglycemia due to insulin-binding autoantibodies, may be difficult to distinguish from tumoral or other forms of hyperinsulinemic hypoglycemia, including surreptitious insulin administration. No standardized treatment regimen exists.

Objectives

To evaluate an analytic approach to IAS and responses to different treatments.

Design and Setting

Observational study in the UK Severe Insulin Resistance Service.

Patients

Six patients with hyperinsulinemic hypoglycemia and detectable circulating anti-insulin antibody (IA).

Main Outcome Measures

Glycemia, plasma insulin, and C-peptide concentrations by immunoassay or mass spectrometry (MS). Immunoreactive insulin was determined in the context of polyethylene glycol (PEG) precipitation and gel filtration chromatography (GFC). IA quantification using ELISA and RIA, and IA were further characterized using radioligand binding studies.

Results

All patients were diagnosed with IAS (five IgG, one IgA) based on a high insulin/C-peptide ratio, low insulin recovery after PEG precipitation, and GFC evidence of antibody-bound insulin. Neither ELISA nor RIA result proved diagnostic for every case. MS provided a more robust quantification of insulin in the context of IA. One patient was managed conservatively, four were treated with diazoxide without sustained benefit, and four were treated with immunosuppression with highly variable responses. IA affinity did not appear to influence presentation or prognosis.

Conclusions

IAS should be considered in patients with hyperinsulinemic hypoglycemia and a high insulin/C-peptide ratio. Low insulin recovery on PEG precipitation supports the presence of insulin-binding antibodies, with GFC providing definitive confirmation. Immunomodulatory therapy should be customized according to individual needs and clinical response.

Low Altitude Solar Magnetic Reconnection, Type III Solar Radio Bursts, and X-ray Emissions

Type III solar radio bursts are the Sun's most intense and frequent nonthermal radio emissions. They involve two critical problems in astrophysics, plasma physics, and space physics: how collective processes produce nonthermal radiation and how magnetic reconnection occurs and changes magnetic energy into kinetic energy. Here magnetic reconnection events are identified definitively in Solar Dynamics Observatory UV-EUV data, with strong upward and downward pairs of jets, current sheets, and cusp-like geometries on top of time-varying magnetic loops, and strong outflows along pairs of open magnetic field lines. Type III bursts imaged by the Murchison Widefield Array and detected by the Learmonth radiospectrograph and STEREO B spacecraft are demonstrated to be in very good temporal and spatial coincidence with specific reconnection events and with bursts of X-rays detected by the RHESSI spacecraft. The reconnection sites are low, near heights of 5-10 Mm. These images and event timings provide the long-desired direct evidence that semi-relativistic electrons energized in magnetic reconnection regions produce type III radio bursts. Not all the observed reconnection events produce X-ray events or coronal or interplanetary type III bursts; thus different special conditions exist for electrons leaving reconnection regions to produce observable radio, EUV, UV, and X-ray bursts.

SmgGDS is a transient nucleolar protein that protects cells from nucleolar stress and promotes the cell cycle by regulating DREAM complex gene expression

The chaperone protein and guanine nucleotide exchange factor SmgGDS (RAP1GDS1) is a key promoter of cancer cell proliferation and tumorigenesis. SmgGDS undergoes nucleocytoplasmic shuttling, suggesting that it has both cytoplasmic and nuclear functions that promote cancer. Previous studies indicate that SmgGDS binds cytoplasmic small GTPases and promotes their trafficking to the plasma membrane. In contrast, little is known about the functions of SmgGDS in the nucleus, or how these nuclear functions might benefit cancer cells. Here we show unique nuclear localization and regulation of gene transcription pathways by SmgGDS. Strikingly, SmgGDS depletion significantly reduces expression of over 600 gene products that are targets of the DREAM complex, which is a transcription factor complex that regulates expression of proteins controlling the cell cycle. The cell cycle regulators E2F1, MYC, MYBL2 (B-Myb) and FOXM1 are among the DREAM targets that are diminished by SmgGDS depletion. E2F1 is well known to promote G1 cell cycle progression, and the loss of E2F1 in SmgGDS-depleted cells provides an explanation for previous reports that SmgGDS depletion characteristically causes a G1 cell cycle arrest. We show that SmgGDS localizes in nucleoli, and that RNAi-mediated depletion of SmgGDS in cancer cells disrupts nucleolar morphology, signifying nucleolar stress. We show that nucleolar SmgGDS interacts with the RNA polymerase I transcription factor upstream binding factor (UBF). The RNAi-mediated depletion of UBF diminishes nucleolar localization of SmgGDS and promotes proteasome-mediated degradation of SmgGDS, indicating that nucleolar sequestration of SmgGDS by UBF stabilizes SmgGDS protein. The ability of SmgGDS to interact with UBF and localize in the nucleolus is diminished by expressing DiRas1 or DiRas2, which are small GTPases that bind SmgGDS and act as tumor suppressors. Taken together, our results support a novel nuclear role for SmgGDS in protecting malignant cells from nucleolar stress, thus promoting cell cycle progression and tumorigenesis.

The Nogo-B receptor promotes Ras plasma membrane localization and activation

The localization of prenylated Ras at the plasma membrane promotes activation of Ras by receptor tyrosine kinases and stimulates oncogenic signaling by mutant Ras. The Nogo-B receptor (NgBR) is a transmembrane receptor that contains a conserved hydrophobic pocket. Here, we demonstrate that the NgBR promotes the membrane accumulation of Ras by directly binding prenylated Ras at the plasma membrane. We show that NgBR knockdown diminishes the membrane localization of Ras in multiple cell types. NgBR overexpression in NIH-3T3 fibroblasts increases membrane-associated Ras, induces the transformed phenotype in vitro, and promotes the formation of fibrosarcoma in nude mice. NgBR knockdown in human breast cancer cells reduces Ras membrane localization, inhibits EGF-stimulated Ras signaling, and diminishes tumorigenesis of xenografts in nude mice. Our data demonstrate that NgBR is a unique receptor that promotes accumulation of prenylated Ras at the plasma membrane and promotes EGF pathways.

Frictional resistance of three types of ceramic brackets

Objectives

To investigate the static frictional resistance at the bracket/archwire interface in two recently introduced bracket systems and compare them to conventional ceramic and conventional metal bracket systems. Three variables were considered including the bracket system, archwire type and archwire angulation.

Material and Methods

Four bracket systems were tested in vitro: Self ligating ceramic, ceramic with metal slot and module, conventional ceramic with module and conventional metal with module. A specially constructed jig and an Instron testing machine were used to measure the static frictional resistance for 0.014 inches round and 0.018 x 0.025 inches rectangular stainless steel wires at 0° and 7° angulations. Main outcome measures: static frictional force at the bracket/archwire interface; recorded and measured in units of force (Newtons).

Results

Self ligating ceramic and metal slot ceramic bracket systems generated significantly less static frictional resistance than conventional ceramic bracket systems with the wire at both angulations (P < 0.05). Changing the wire from 0.014 round to 0.018 x 0.025 rectangular wire significantly increased frictional forces for metal slot ceramic and conventional metal bracket systems (P < 0.01). Increasing wire angulation significantly increased frictional resistance at the bracket/archwire interface for all four types of bracket systems tested (P < 0.001).

Conclusions

Compared to conventional ceramic, self ligating ceramic and metal slot ceramic bracket systems should give improved clinical performance, matching that of conventional metal brackets.

Prevention programs for refugees: An interface for mental health and public health

Refugee movements impose tremendous psychological and physical trauma on survivors, making refugees a high risk group for psychopathology and psycho-social adjustment problems. Prevention programs based on public mental health principles are needed for refugees, but few exist, and none have been evaluated empirically to determine if they lower rates of illness or other psycho-social problems. This paper explores impediments to the development of prevention programming for refugees and describes public mental health strategies for the psycho-social problems of refugees. A necessary step towards the development of prevention programs is the recognition that a substantial body of knowledge exists about the refugee experience and its community mental health implications. Attention to prevention is important, particularly the need to evaluate empirically any prevention program's effectiveness with refugees.

Squaring the circle in peptide assembly: from fibers to discrete nanostructures by de novo design

The design of bioinspired nanostructures and materials of defined size and shape is challenging as it pushes our understanding of biomolecular assembly to its limits. In such endeavors, DNA is the current building block of choice because of its predictable and programmable self-assembly. The use of peptide- and protein-based systems, however, has potential advantages due to their more-varied chemistries, structures and functions, and the prospects for recombinant production through gene synthesis and expression. Here, we present the design and characterization of two complementary peptides programmed to form a parallel heterodimeric coiled coil, which we use as the building blocks for larger, supramolecular assemblies. To achieve the latter, the two peptides are joined via peptidic linkers of variable lengths to produce a range of assemblies, from flexible fibers of indefinite length, through large colloidal-scale assemblies, down to closed and discrete nanoscale objects of defined stoichiometry. We posit that the different modes of assembly reflect the interplay between steric constraints imposed by short linkers and the bulk of the helices, and entropic factors that favor the formation of many smaller objects as the linker length is increased. This approach, and the resulting linear and proteinogenic polypeptides, represents a new route for constructing complex peptide-based assemblies and biomaterials.

Interactions between epinephrine, ascending vagal fibers, and central noradrenergic systems in modulating memory for emotionally arousing events

It is well-established that exposure to emotionally laden events initiates secretion of the arousal-related hormone epinephrine in the periphery. These neuroendocrine changes and the subsequent increase in peripheral physiological output play an integral role in modulating brain systems involved in memory formation. The impermeability of the blood brain barrier to epinephrine represents an important obstacle in understanding how peripheral hormones initiate neurochemical changes in the brain that lead to effective memory formation. This obstacle necessitated the identity of a putative pathway capable of conveying physiological changes produced by epinephrine to limbic structures that incorporate arousal and affect related information into memory. A major theme of the proposed studies is that ascending fibers of the vagus nerve may represent such a mechanism. This hypothesis was tested by evaluating the contribution of ascending vagal fibers in modulating memory for responses learned under behavioral conditions that produce emotional arousal by manipulating appetitive stimuli. A combination of electrophysiological recording of vagal afferent fibers and in vivo microdialysis was employed in a second study to simultaneously assess how elevations in peripheral levels of epinephrine affect vagal nerve discharge and the subsequent potentiation of norepinephrine release in the basolateral amygdala. The final study used double immunohistochemistry labeling of c-fos and dopamine beta hydroxylase (DBH), the enzyme for norepinephrine synthesis to determine if epinephrine administration alone or stimulation of the vagus nerve at an intensity identical to that which improved memory in Experiment 1 produces similar patterns of neuronal activity in brain areas involved in processing memory for emotional events. Findings emerging from this collection of studies establish the importance of ascending fibers of the vagus nerve as an essential pathway for conveying the peripheral consequences of physiological arousal on brain systems that encode new information into memory storage.

Dietary shifts affect the gastrointestinal microflora of the giant panda (Ailuropoda melanoleuca)

Giant pandas exhibit seasonal changes in bamboo plant part preference. The influences on the gastrointestinal tracts (GIT) microbial populations were evaluated during a 14-month period for a pair of adult male and female giant pandas housed at the Memphis Zoo using traditional culturing methods to enumerate eight bacterial groups (total anaerobes, total aerobes (TAR), streptococci (STR), total enterics, Escherichia coli, Bacteroides spp., lactobacilli and Clostridium spp.). Both the male and female pandas altered bamboo consumption behaviours, with a sharp decrease in leaf preference in April 2010 and returning to high levels of leaf preference from June to October, corresponding to significant shifts in the densities of TAR, STR, and lactobacilli and Bacteroides spp. These findings indicate seasonal changes in food preference affect the assemblages of microbial populations within the GIT of the giant panda and contribute to a better understanding of the importance of bamboo in this species' foraging strategy.

[Dietary fiber and nutritional support in pediatrics: current understanding]

The article summarizes the materials on the use of dietary fiber (DF) in the diet of children of different ages. According to the few studies that DF used in children's diets, play an important role in the prevention and treatment of obesity and in lowering serum cholesterol, which reduces the risk of children of cardiovascular disease. Given that children and adolescents consume food insufficient number of DF should be encouraged to increase in baby food for their consumption at the expense of fruit, vegetables and products prepared from cereals. A number of recommendations on the level of consumption of DF children and adolescents of all ages.

O2 store management in diving emperor penguins

In order to further define O(2) store utilization during dives and understand the physiological basis of the aerobic dive limit (ADL, dive duration associated with the onset of post-dive blood lactate accumulation), emperor penguins (Aptenodytes forsteri) were equipped with either a blood partial pressure of oxygen (P(O(2))) recorder or a blood sampler while they were diving at an isolated dive hole in the sea ice of McMurdo Sound, Antarctica. Arterial P(O(2)) profiles (57 dives) revealed that (a) pre-dive P(O(2)) was greater than that at rest, (b) P(O(2)) transiently increased during descent and (c) post-dive P(O(2)) reached that at rest in 1.92+/-1.89 min (N=53). Venous P(O(2)) profiles (130 dives) revealed that (a) pre-dive venous P(O(2)) was greater than that at rest prior to 61% of dives, (b) in 90% of dives venous P(O(2)) transiently increased with a mean maximum P(O(2)) of 53+/-18 mmHg and a mean increase in P(O(2)) of 11+/-12 mmHg, (c) in 78% of dives, this peak venous P(O(2)) occurred within the first 3 min, and (d) post-dive venous P(O(2)) reached that at rest within 2.23+/-2.64 min (N=84). Arterial and venous P(O(2)) values in blood samples collected 1-3 min into dives were greater than or near to the respective values at rest. Blood lactate concentration was less than 2 mmol l(-1) as far as 10.5 min into dives, well beyond the known ADL of 5.6 min. Mean arterial and venous P(N(2)) of samples collected at 20-37 m depth were 2.5 times those at the surface, both being 2.1+/-0.7 atmospheres absolute (ATA; N=3 each), and were not significantly different. These findings are consistent with the maintenance of gas exchange during dives (elevated arterial and venous P(O(2)) and P(N(2)) during dives), muscle ischemia during dives (elevated venous P(O(2)), lack of lactate washout into blood during dives), and arterio-venous shunting of blood both during the surface period (venous P(O(2)) greater than that at rest) and during dives (arterialized venous P(O(2)) values during descent, equivalent arterial and venous P(N(2)) values during dives). These three physiological processes contribute to the transfer of the large respiratory O(2) store to the blood during the dive, isolation of muscle metabolism from the circulation during the dive, a decreased rate of blood O(2) depletion during dives, and optimized loading of O(2) stores both before and after dives. The lack of blood O(2) depletion and blood lactate elevation during dives beyond the ADL suggests that active locomotory muscle is the site of tissue lactate accumulation that results in post-dive blood lactate elevation in dives beyond the ADL.

SmgGDS is up-regulated in prostate carcinoma and promotes tumour phenotypes in prostate cancer cells

SmgGDS is a guanine nucleotide exchange factor with the unique ability to activate multiple small GTPases, implicating it in cancer development and progression. Here, we investigated the role of SmgGDS in prostate cancer by studying the expression of SmgGDS in benign and malignant prostatic tissues. We also probed SmgGDS function in three prostate carcinoma cell lines using small interfering RNA (siRNA). Immunohistochemical analysis revealed that SmgGDS levels were elevated in prostatic intraepithelial neoplasia (PIN), prostate carcinoma, and metastatic prostate carcinoma. In addition, expression of SmgGDS positively correlated with that of cyclooxygenase-2 (COX-2), a protein believed to promote the development of prostate carcinoma. Reduction of SmgGDS expression in prostate carcinoma cells inhibited proliferation and migration, irrespective of androgen receptor status. These effects were accompanied by a reduction in COX-2 expression and in activity of NF-kappaB, a known regulator of COX-2. Taken together, these findings suggest that SmgGDS promotes the development and progression of prostate cancer, possibly associated with NF-kappaB-dependent up-regulation of COX-2.

Returning on empty: extreme blood O2 depletion underlies dive capacity of emperor penguins

Blood gas analyses from emperor penguins (Aptenodytes forsteri) at rest, and intravascular P(O(2)) profiles from free-diving birds were obtained in order to examine hypoxemic tolerance and utilization of the blood O(2) store during dives. Analysis of blood samples from penguins at rest revealed arterial P(O(2))s and O(2) contents of 68+/-7 mmHg (1 mmHg= 133.3 Pa) and 22.5+/-1.3 ml O(2) dl(-1) (N=3) and venous values of 41+/-10 mmHg and 17.4+/-2.9 ml O(2) dl(-1) (N=9). Corresponding arterial and venous Hb saturations for a hemoglobin (Hb) concentration of 18 g dl(-1) were >91% and 70%, respectively. Analysis of P(O(2)) profiles obtained from birds equipped with intravascular P(O(2)) electrodes and backpack recorders during dives revealed that (1) the decline of the final blood P(O(2)) of a dive in relation to dive duration was variable, (2) final venous P(O(2)) values spanned a 40-mmHg range at the previously measured aerobic dive limit (ADL; dive duration associated with onset of post-dive blood lactate accumulation), (3) final arterial, venous and previously measured air sac P(O(2)) values were indistinguishable in longer dives, and (4) final venous P(O(2)) values of longer dives were as low as 1-6 mmHg during dives. Although blood O(2) is not depleted at the ADL, nearly complete depletion of the blood O(2) store occurs in longer dives. This extreme hypoxemic tolerance, which would be catastrophic in many birds and mammals, necessitates biochemical and molecular adaptations, including a shift in the O(2)-Hb dissociation curve of the emperor penguin in comparison to those of most birds. A relatively higher-affinity Hb is consistent with blood P(O(2)) values and O(2) contents of penguins at rest.

Exercise training for depressed older adults with Alzheimer's disease

The purpose of this study was to compare the effects of 16 weeks of a comprehensive exercise routine to supervised walking and social conversation on depression in nursing home residents with Alzheimer's disease (AD).

METHOD

This study was a three-group, repeated-measures design with random assignment to treatment group. Forty-five nursing home residents with moderate to severe AD were randomly assigned to a 16-week programme of comprehensive exercise, supervised walking or social conversation. Raters were blinded to treatment group assignment. Major outcome variables were depression measured by the Cornell Scale for Depression in Dementia, mood measured by the Dementia Mood Assessment Scale and the Alzheimer's Mood Scale, and affect measured by the Observed Affect Scale. Depression was reduced in all three groups with some evidence of superior benefit from exercise. Depression is a common problem with serious and costly consequences for nursing home residents with AD. Exercise as a behavioural approach to treatment of depression in nursing home residents with severe AD evidenced a clear benefit to participants in this study. More research is needed to clarify the relative benefits of different types of exercise in conjunction with or without pharmacological intervention.

Fluconazole and itraconazole susceptibilities of Candida spp. isolated from oropharyngeal specimens and blood cultures of paediatric haematology/oncology patients

This study examined the in vitro susceptibilities to fluconazole and itraconazole of isolates of Candida spp. from surveillance oropharyngeal specimens and blood cultures from paediatric patients with malignancy. The species distribution of 100 isolates from oropharyngeal specimens was C. albicans 86%, C. glabrata 7%, C. lusitaniae 4%, C. parapsilosis 2% and C. tropicalis 1%. From a total of nine isolates from blood cultures the species distribution was C. albicans 33.3%, C. parapsilosis 33.3 % and C. guilliermondii 33.3%. Only three of the oropharyngeal isolates were resistant to fluconazole (MIC > or = 64 mg l(-1)) and only two were resistant to itraconazole (MIC > or = 1 mg l(-1)). None of the blood culture isolates was resistant to either agent. At this centre, C. albicans is the predominant species from oropharyngeal specimens, but non-albicans Candida species predominate in blood cultures. Although resistance to fluconazole and itraconazole is rare at present, continued surveillance is warranted to monitor trends in species distribution and antifungal susceptibility.

Epinephrine administration increases neural impulses propagated along the vagus nerve: Role of peripheral beta-adrenergic receptors

A significant number of animal and human studies demonstrate that memories for new experiences are encoded more effectively under environmental or laboratory conditions which elevate peripheral concentrations of the hormone epinephrine and in turn, induce emotional arousal. Although this phenomenon has been replicated across several learning paradigms, understanding of how this arousal related hormone affects memory processing remains obscure because epinephrine does not freely enter into the central circulation to produce any direct effects on the brain. This study examined whether epinephrine's actions on the CNS may be mediated by the initial activation of peripheral vagal fibers that project to the brain. The vagus was selected as a candidate for this role since it is densely embedded with beta-adrenergic receptors and the peripheral endings of this nerve innervate a broad spectrum of sensory organs that are directly affected by epinephrine release. Electrophysiological recordings of cervical vagal activity was measured over 110 min in urethane-anesthetized Sprague-Dawley rats given saline, epinephrine (0.3 mg/kg), the peripherally acting beta-adrenergic antagonist sotalol (2.0 mg/kg), or a combination of sotalol followed 15 min later by an injection of epinephrine. Epinephrine produced a significant increase in vagal nerve firing 10 min post-injection (p < .05) relative to controls and neural impulses recorded from the vagus remained significantly elevated for the remaining 55 min collection period. The excitatory actions of epinephrine were not observed in groups given an identical dose of the hormone after peripheral beta-adrenergic receptor blockade with sotalol. These findings demonstrate that neural discharge in vagal afferent fibers is increased by elevations in peripheral concentrations of epinephrine and the significance of these findings in understanding how epinephrine modulates brain limbic structures to encode and store new information into memory is discussed.

Fatal adverse pulmonary reaction in calves after inadvertent intravenous vaccination

Fatal adverse reactions to vaccination are uncommon and poorly documented. To our knowledge, this is the first case report of fatal adverse reaction to an inadvertent intravenous vaccination in three calves vaccinated against respiratory (Somnustar Ph) and clostridial (Tasvax 8) diseases. All three calves had severe acute interstitial pneumonia with multifocal pulmonary hemorrhages that resulted in fatal respiratory failure. Qualitatively, the pulmonary lesions in these calves were similar to those in septicemic/endotoxemic calves; however, the severity and extensity of pulmonary hemorrhages were of a higher degree than those usually observed in clinical septicemia/endotoxemia. In addition, approximately 30% of the arterioles and small arteries were surrounded by hemorrhages, which occasionally extended around adjacent bronchioles. A unilateral peri-jugular hematoma with recent transmural perforation of jugular vein found in all three calves was believed to have been caused by the injection needle during vaccination, and the fatal pulmonary changes were believed to have been secondary to the intravenous injection of vaccine.

Copper-induced hepatotoxicosis with hepatic stellate cell activation and severe fibrosis in North Ronaldsay lambs: a model for non-Wilsonian hepatic copper toxicosis of infants

Copper-sensitive North Ronaldsay sheep represent a possible model for certain hepatic-overload syndromes of infancy and childhood that are clinically, pathologically and genetically distinct from Wilson's disease. The purpose of this study was to simulate in artificially reared lambs the syndrome produced by copper exposure in susceptible human infants. Twenty four North Ronaldsay lambs were assigned to three groups of eight animals, namely, an unsupplemented control group and two trial groups given milk replacer to which copper (CuSO4) had been added at the rate of 5 mg/litre and 10 mg/litre. Four lambs from each group were killed at 40 or 69 days. Livers were fixed in 10% formalin and analysed for copper by mass spectrometry. Paraffin wax-embedded sections were stained with rhodanine for copper and labelled immunohistochemically for alpha smooth muscle actin (ASMA). At 40 days the maximum amounts of copper in the livers of both copper-supplemented groups was 1466-1605 microg/g dry weight (control group 172-201 microg/g Cu dry weight). Histochemically, copper was demonstrated within hepatocytes, together with marked apoptosis. At 69 days there was a florid pericellular fibrosis complemented by strong ASMA immunolabelling, confirming phenotypic modulation of hepatic stellate cells. Such primary copper-induced fibrogenesis confirms the unique status of this animal model in respect of childhood copper toxicosis.

The effects of peripheral vagal nerve stimulation at a memory-modulating intensity on norepinephrine output in the basolateral amygdala

Vagal nerve stimulation (VNS) is known to improve cognitive processing, presumably by affecting activity in central nervous system structures that process recently acquired information. It has long been assumed that these effects are related to stimulation-induced increases of norepinephrine (NE) release in limbic brain structures. The present study examined this hypothesis by administering VNS at an intensity and duration that improves memory and then measuring fluctuations in NE output in the basolateral amygdala (BLA) with in vivo microdialysis. In Experiment 1, VNS caused a 98% increase in NE output relative to baseline. In Experiment 2, methyl atropine was given 10 min before VNS to assess whether stimulation-induced increases in amygdala NE are mediated by afferent or efferent vagal branches. Methyl atropine did not alter NE release in the BLA in comparison with saline. The significance of these findings in understanding how peripheral neural activity modulates limbic structures to encode and store new information into memory is discussed.

Evaluation of protocol using gene capture and PCR for detection of Helicobacter pylori DNA in feces

The route of transmission of Helicobacter pylori, which is usually acquired in childhood and is one of the most common bacterial infections in humans, remains undetermined. Mapping the distribution of H. pylori genotypes within families could help to determine the routes of transmission and risk factors. Here we describe a noninvasive method for obtaining H. pylori DNA isolates from the feces of children. Children presenting with gastrointestinal symptoms at the Royal Hospital for Sick Children were tested for gastric H. pylori colonization by using the 13C-urea breath test (UBT) and were asked to provide fecal samples, which were tested for H. pylori by using the HpSA fecal antigen test. DNA was purified from fecal samples by using a novel method of gene capture with subsequent H. pylori PCR analysis. Fifteen UBT-positive and 15 UBT-negative children participated in the study. The positive and negative predictive values for the assay were 80 and 100%, respectively. Fecal DNA purification followed by H. pylori PCR analysis is an effective tool for harvesting H. pylori DNA isolates from the feces of children. This technique may be developed to allow the diagnosis and noninvasive genotyping of H. pylori in children and their families.

Formation of the arthrodial membrane in the blue crab, Callinectes sapidus

In this study the pattern of arthrodial membrane deposition in Callinectes sapidus was determined by histological and ultrastructural examination of tissues from the carpus joint of the cheliped collected during premolt, ecdysis, postmolt, and intermolt. Apolysis in the arthrodial membrane occurs at stage D(0) and is synchronous with apolysis of the calcified cuticle. Epicuticle formation begins at early stage D(1) and is completed in late stage D(1). Procuticle deposition starts at D(2) and continues until ecdysis. Numerous cytoplasmic extensions occur throughout the lamellae. Component fibers of the arthrodial membrane are intimately associated with dense plaques on the apical membrane of the underlying hypodermal cells, suggesting a site for fiber polymerization. Deposition of the arthrodial membrane continues after ecdysis, with most of the cuticle thickening occurring during stage C. When stained with PAS and counterstained with hematoxylin, a difference can be discerned between preecdysial and postecdysial procuticle of the arthrodial membrane, a distinction not made in previous studies. The boundary between the arthrodial membrane and calcified cuticle is thicker than either of the two layers and the layers overlap rather than butting up against one another. This pattern suggests that underlying hypodermal cells have to produce multiple types of cuticle over the molt cycle. A summary of the various molting patterns in C. sapidus suggests that the control of these diverse events may prove to be complex.

Water, water everywhere nor any a sterile drop to rinse your endoscope

Traditional waterborne infections have been largely controlled in the UK by the provision of clean drinking water. However, water can still cause problems for infection control teams in particular when used in endoscope washer-disinfectors. HTM 2030 states that final rinse water used in washer-disinfectors must not present a microbiological hazard and that there should be no recovery of micro-organisms from the final rinse water. The problems that biofilms may cause in washer-disinfectors, the type of biofilms that may develop, and the nature of the bacteria within them, in particular how biofilm bacteria behave differently to those that are not part of a biofilm (planktonic bacteria), are discussed in this article. Finally, we discuss how knowledge of the growth and control of biofilms may be used to control their growth.

Smooth estimation of the reliability function

Problems with censored data arise quite frequently in reliability applications. Estimation of the reliability function is usually of concern. Reliability function estimators proposed by Kaplan and Meier (1958), Breslow (1972), are generally used when dealing with censored data. These estimators have the known properties of being asymptotically unbiased, uniformly strongly consistent, and weakly convergent to the same Gaussian process, when properly normalized. We study the properties of the smoothed Kaplan-Meier estimator with a suitable kernel function in this paper. The smooth estimator is compared with the Kaplan-Meier and Breslow estimators for large sample sizes giving an exact expression for an appropriately normalized difference of the mean square error (MSE) of the two estimators. This quantifies the deficiency of the Kaplan-Meier estimator in comparison to the smoothed version. We also obtain a non-asymptotic bound on an expected L1-type error under weak conditions. Some simulations are carried out to examine the performance of the suggested method.

Reduced expression of Wnt-1 and E-cadherin, and diminished beta-catenin stability in MCF-7 breast cancer cells that overexpress protein kinase C-alpha

MCF-7 breast cancer cells stably overexpressing protein kinase C-alpha (MCF-7-PKC-alpha cells) exhibit reduced cell-cell adhesion and increased tumorigenicity in nude mice. We investigated the possibility that alterations in E-cadherin and catenins contribute to the unique phenotype of MCF-7-PKC-alpha cells. Northern and Western blotting indicated that MCF-7-PKC-alpha cells express abnormally low amounts of plakoglobin mRNA and protein, and undetectable levels of E-cadherin mRNA and protein. In contrast, even though MCF-7-PKC-alpha cells express low levels of beta-catenin mRNA, they express undetectable levels of beta-catenin protein, suggesting that post-transcriptional events further diminish beta-catenin expression in these cells. Pulse-labeling of the cells with [35S]methionine showed that the half-life of beta-catenin is less than 15 min in MCF-7-PKC-alpha cells, compared to over 2 h in MCF-7-Vector cells [MCF-7 cells transfected with pSV2M(2)6 vector only]. Incubation with LiCl to inactivate glycogen synthase kinase-3 (GSK-3) significantly prolonged the half-life of beta-catenin in MCF-7-PKC-alpha cells, suggesting that the GSK-3-dependent degradation of beta-catenin contributes to beta-catenin instability in these cells. Northern and Western blotting indicated that Wnt-1, which also inhibits GSK-3 activity, is expressed by MCF-7-Vector cells, but not by MCF-7-PKC-alpha cells. Transfection of (S37A)beta-catenin, which is resistant to GSK-3-dependent degradation, stimulated TCF/LEF-dependent luciferase expression from the pTOPFLASH reporter plasmid by 753-fold in MCF-7-PKC-alpha cells, and by 268-fold in MCF-7-Vector cells. Inactivation of GSK-3 by LiCl stimulated luciferase expression from the pTOPFLASH reporter plasmid by 12.4-fold in MCF-7-PKC-alpha cells, and by 4.8-fold in MCF-7-Vector cells. These results suggest that degradation of beta-catenin by GSK-3 contributes to beta-catenin instability in MCF-7-PKC-alpha cells, diminishing the ability of -catenin to act as a transcriptional co-activator. Reduced Wnt-1 expression by MCF-7-PKC-alpha cells may promote beta-catenin degradation by enhancing GSK-3 activity. Loss of beta-catenin-dependent cell-cell adhesion and transcription may contribute to the aggressive phenotype of MCF-7-PKC-alpha cells.

Prevention and treatment of childhood obesity

Obesity has reached epidemic proportions among children and youth in the United States. Surveys indicate that the number of overweight children aged 6 to 17 years has doubled within three decades. In the decade between the late 1970s and the late 1980s, the prevalence of overweight increased from 7.6% to 10.9% for children aged 6 to 11 years, and from 5.7% to 10.8% for adolescents aged 12 to 19 years. Data for 1999 indicates that the epidemic is continuing to increase, so that 13% of 6- to 11-year-old children and 14% of 12- to 19-year- old children are currently overweight (body mass index > or = 95th percentile for age/gender). This article reviews newer concepts related to etiologic factors, comorbidities, and strategies for prevention and treatment.

Childhood obesity: the health issue

Overweight and obesity in children is epidemic in North America and internationally. Approximately 22 million children under 5 years of age are overweight across the world. In the United States, the number of overweight children and adolescents has doubled in the last two to three decades, and similar doubling rates are being observed worldwide, including in developing countries and regions where an increase in Westernization of behavioral and dietary lifestyles is evident. Comorbidities associated with obesity and overweight are similar in children as in the adult population. Elevated blood pressure, dyslipidemia, and a higher prevalence of factors associated with insulin resistance and type 2 diabetes appear as frequent comorbidities in the overweight and obese pediatric population. In some populations, type 2 diabetes is now the dominant form of diabetes in children and adolescents. Disturbingly, obesity in childhood, particularly in adolescence, is a key predictor for obesity in adulthood. Moreover, morbidity and mortality in the adult population is increased in individuals who were overweight in adolescence, even if they lose the extra weight during adulthood. Although the cause of obesity in children is similar to that of adults (i.e., more energy in vs. energy utilized), emerging data suggest associations between the influence of maternal and fetal factors during intrauterine growth and growth during the first year of life, on risk of later development of adult obesity and its comorbidities. In addition, recent data suggest that varying biological responses in different racial/ethnic groups differently contribute to overweight, obesity, and their comorbidities. Although differences in gene-nutrient interactions may contribute, the role of varying cultural and socioeconomic variables still needs to be determined to understand these disparities. Novel approaches in the prevention and treatment of childhood overweight and obesity are urgently required. With the strong evidence that a lifecycle perspective is important in obesity development and its consequences, consideration must be focused on prevention of obesity in women of child-bearing age, excessive weight gain during pregnancy, and the role of breast-feeding in reducing later obesity in children and adults. Consideration must be given to family behavior patterns, diet after weaning, and the use of new methods of information dissemination to help reduce the impact of childhood obesity worldwide.

Russian-American partners for prevention. Adaptation of a school-based parent-child programme for alcohol use prevention

BACKGROUND

The Russian-American Partners for Prevention was an adaptation and evaluation of the Slick Tracy Home Team Program which was developed in Minnesota in order to delay the onset of drinking. The Slick Tracy Home Team Program was the first intervention of Project Northland, a large 3 year community trial of the efficacy of a public health intervention for under age drinking.

METHODS

The programme was administered through schools, but involved parents using engaging and fun homework activities. The Russian version was implemented in fifth-grade classrooms in 20 Moscow schools with 1,212 students surveyed at baseline. Students were surveyed again after programme implementation (n = 1,182), of whom 980 were present at baseline. Parents of 1,078 students were surveyed by telephone after programme implementation.

RESULTS

The results demonstrated the successful recruitment and retention of 20 Moscow schools in a research project, acceptability of programme materials in Russia, high participation rates, changes in students' knowledge about problems associated with under age drinking and some evidence about increases in parent-child communication about alcohol use. As in the USA, no changes in students' alcohol use rates were observed at the end of the first year of the 3 year programme.

CONCLUSION

Russian youth, as compared to Americans, began drinking at earlier ages, received fewer prevention messages from their parents, and had fewer prevention programmes in school. The results suggested that carefully implemented and evaluated replications of the US Project Northland interventions might provide effective and appropriate school-based programmes for Russia.

Subject and observer-rated quality of life in schizophrenia

OBJECTIVE

We aimed to explore the relationship between objectively rated quality of life and subjective measures of social functioning and life satisfaction.

METHOD

Participants of the Schizophrenia Care and Assessment Program (SCAP) study at Dandenong in Australia were included in this analysis. Subjective ratings of several domains of social functioning and life satisfaction were taken from the SCAP instrument and comparisons made with data from the Quality of Life scale rated by research staff as well as several psychopathology measures.

RESULTS

Subjectively reported life satisfaction was not related to positive or negative symptoms of schizophrenia but did correlate with depressive symptoms. Quality of Life scale measures correlated with negative symptoms on most domains. There was very limited overlap in domain items between the life satisfaction and quality of life measures.

CONCLUSION

Life satisfaction and objectively rated quality of life are not closely related and appear to have different determinants in patients with schizophrenia.

Memory retention is modulated by acute estradiol and progesterone replacement

Ovarian hormones alter spine density of hippocampal granule and pyramidal cells in young adult and aging female rats (P. Miranda, C. L. Williams, & G. Einstein, 1999; C. S. Woolley, 1998). The present study used a delayed matching-to-place version of the water maze to investigate a behavioral correlate of these hormone-induced changes in hippocampal connectivity in 3- and 8-month-old female rats. When primed with 10-microg injections of estradiol 72 and 48 hr before testing, the memory retention of ovariectomized rats was improved compared with retention after priming with oil. A single injection of progesterone maintained this enhancement if testing occurred within 8 hr of the progesterone injection but not if testing occurred more than 24 hr after the progesterone injection. These findings indicate that estradiol and progesterone alter memory retention and suggest that these changes may be the result of hormone-induced increases in hippocampal connectivity.

The effects of noradrenergic activation of the nucleus tractus solitarius on memory and in potentiating norepinephrine release in the amygdala

Although it is known that norepinephrine (NE) modulates memory by acting on limbic areas, few studies describe how structures supplying NE to the limbic system, such as the nucleus tractus solitarius (NTS) contribute to this process. The present study examined the effects on memory of activating the NE pathway between the NTS and the amygdala (AMYG). Rats received buffer or the beta-noradrenergic agonist clenbuterol (CLN; 10, 50, or 100 ng/0.5 microl) into the NTS after footshock training in a Y-maze discrimination task. Infusion of 100 ng CLN significantly improved memory when retention was tested in the absence or presence of cues associated with the footshock. Experiment 2 used in vivo microdialysis to determine whether the mnemonic effects of CLN are mediated by influencing NE output in the AMYG. Subjects were given an intra-NTS infusion of CLN or phosphate buffered saline, footshock (0.8 mA, 1 s), and injected with epinephrine (EPI; 0.3 mg/kg ip) or saline. CLN or EPI injection produced a significant increase in NE sampled from the AMYG. These findings indicate that activation of NTS neurons that project to and release NE in the AMYG modulates memory storage processing.

How did Project Northland reduce alcohol use among young adolescents? Analysis of mediating variables

Project Northland is a randomized trial designed to create, implement and evaluate multilevel, community-wide strategies to prevent alcohol use among adolescents. This paper will focus on the mediating outcomes of the early adolescent phase of Project Northland when the students in the study cohort were in Grades 6-8. The project was conducted in 24 school districts and adjacent communities in northeastern Minnesota. The intervention consisted of social-behavioral curricula in schools, peer leadership activities, parental involvement and education, and community-wide activities. At the end of 3 years of intervention, significantly fewer students in the intervention school districts reported alcohol use than students in the reference districts. Mediation analyses were conducted to investigate if the intervention's effects on mediating variables could explain the reduction in alcohol use. Important mediators of Project Northland's effect on alcohol use were: (1) peer influence to use, including normative estimates, (2) functional meanings of alcohol use, (3) attitudes and behaviors associated with alcohol and drug problems like stimulus seeking, rule violations and bad judgement, and (4) parent-child alcohol-related communication around alcohol use. In addition, among those who did not use alcohol at baseline, self-efficacy to refuse offers of alcohol was a significant mediator.

Obtaining family consent for participation in Alzheimer's research in a Cuban-American population: strategies to overcome the barriers

Cultural values and beliefs affect family attitudes toward participation in research. Significant resistance to allowing their elders with dementia to participate in clinical research was encountered in Cuban-American families. These families expressed concern about disturbing the elder's comfort (tranquilidad) and solitude (soledad). Furthermore, most believed that intervention would be futile. Feelings of guilt associated with nursing home placement may have been exacerbated by the suggestion that active intervention could be effective. Strategies to overcome these barriers included reduced emphasis on the potential superiority of the intervention to be tested, reassurance that contact with research staff was usually appreciated by participants, arrangements to talk with the family as a group about the study, and increased use of Spanish-language consent forms.

P2Y2 purinergic and M3 muscarinic acetylcholine receptors activate different phospholipase C-beta isoforms that are uniquely susceptible to protein kinase C-dependent phosphorylation and inactivation

Activation of phospholipase C-beta (PLC-beta) by G protein-coupled receptors typically results in rapid but transient second messenger generation. Although PLC-beta deactivation may contribute to the transient nature of this response, the mechanisms governing PLC-beta deactivation are poorly characterized. We investigated the involvement of protein kinase C (PKC) in the termination of PLC-beta activation induced by endogenous P2Y(2) purinergic receptors and transfected M(3) muscarinic acetylcholine receptors (mAChR) in Chinese hamster ovary cells. Activation of P2Y(2) receptors causes Galpha(q/11) to associate with PLC-beta3, whereas M(3) mAChR activation causes Galpha(q/11) to associate with both PLC-beta1 and PLC-beta3 in these cells. Phosphorylation of PLC-beta3, but not PLC-beta1, is induced by activating either P2Y(2) receptors or M(3) mAChR. We demonstrate that PKC rather than protein kinase A mediates the G protein-coupled receptor-induced phosphorylation of PLC-beta3. The PKC-mediated phosphorylation of PLC-beta3 diminishes the interaction of Galpha(q/11) with PLC-beta3, thereby contributing to the termination PLC-beta3 activity. These findings indicate that the distinct temporal profiles of PLC activation by P2Y(2) receptors and mAChR may arise from the differential activation of PLC-beta1 and PLC-beta3 by the receptors, coupled with a selective PKC-mediated negative feedback mechanism that targets PLC-beta3 but not PLC-beta1.

The effects of noradrenergic activation of the nucleus tractus solitarius on memory and in potentiating norepinephrine release in the amygdala

Although it is known that norepinephrine (NE) modulates memory by acting on limbic areas, few studies describe how structures supplying NE to the limbic system, such as the nucleus tractus solitarius (NTS) contribute to this process. The present study examined the effects on memory of activating the NE pathway between the NTS and the amygdala (AMYG). Rats received buffer or the beta-noradrenergic agonist clenbuterol (CLN; 10, 50, or 100 ng/0.5 microl) into the NTS after footshock training in a Y-maze discrimination task. Infusion of 100 ng CLN significantly improved memory when retention was tested in the absence or presence of cues associated with the footshock. Experiment 2 used in vivo microdialysis to determine whether the mnemonic effects of CLN are mediated by influencing NE output in the AMYG. Subjects were given an intra-NTS infusion of CLN or phosphate buffered saline, footshock (0.8 mA, 1 s), and injected with epinephrine (EPI; 0.3 mg/kg ip) or saline. CLN or EPI injection produced a significant increase in NE sampled from the AMYG. These findings indicate that activation of NTS neurons that project to and release NE in the AMYG modulates memory storage processing.

Prenatal choline exposure alters hippocampal responsiveness to cholinergic stimulation in adulthood

Manipulation of dietary choline levels during gestation results in enduring neurobehavioral changes in offspring that last into adulthood. Alterations of hippocampal function and memory are among the most striking changes. Depending upon the measures assessed, prenatal choline supplementation tends to promote excitatory synaptic efficacy in hippocampal circuits while prenatal choline deficiency diminishes it. However, the mechanisms underlying these changes remain unclear. Transverse hippocampal slices were prepared from adult offspring of dams fed choline supplemented, choline deficient, or control diets. We assessed paired-pulse inhibition, and excitatory synaptic responsiveness before and after activation of cholinergic receptors with Carbachol. Prenatally choline deficient animals yielded significantly fewer electrophysiological viable hippocampal slices than did animals from either of the other two treatment groups. Among the slices tested, there were no differences in paired pulse inhibition between the treatment groups. However, transient cholinergic activation resulted in a prolonged enhancement of the amplitude of the population EPSP (pEPSP) response in slices from prenatally choline supplemented animals. These results suggest that GABA receptor-mediated inhibition remains intact after prenatal choline manipulations, and that enhancement of the excitatory responsiveness of hippocampal circuits in slices from prenatally choline supplemented rats may be related in part to an increase in cholinergic tone within the CA1 circuit.

Comparison of an enzyme immunoassay for the detection of Helicobacter pylori antigens in the faeces with the urea breath test

BACKGROUND

Current diagnostic tests for Helicobacter pylori are invasive (endoscopy) or indirect (urea breath test, serology).

AIMS

To evaluate a new enzyme immunoassay (EIA) which detects H pylori antigens in faeces, by comparing its sensitivity and specificity in children with the (13)C urea breath test (UBT).

METHODS

A total of 119 children underwent a UBT and provided a faecal sample for antigen testing within seven days. After an overnight fast each child provided a pretest breath sample, and samples at 30 and 40 minutes after ingestion of 100 mg (13)C labelled urea. (13)C enrichment of breath was measured by isotope ratio mass spectrometry. Faeces were stored at -70 degrees C until antigen testing, using the EIA. Samples were read spectrophotometrically at 450 nm and results were interpreted using recommended cut offs of optical density <0.14 as negative, >/=0.16 as positive, with >/=0.14 and <0. 16 representing equivocal results. Sensitivity and specificity were calculated using the manufacturer's cut off compared with UBT.

RESULTS

Sensitivity and specificity were 88% and 82%, respectively. Negative and positive predictive values were 97% and 58%.

CONCLUSIONS

The EIA is an alternative, non-invasive, and easy to use method for the detection of H pylori in children. Its high negative predictive value suggests a role in screening out uninfected children.