Clinical and vital sign changes associated with late-onset sepsis in very low birth weight infants at 3 NICUs.

BACKGROUND: In premature infants, clinical changes frequently occur due to sepsis or non-infectious conditions, and distinguishing between these is challenging. Baseline risk factors, vital signs, and clinical signs guide decisions to culture and start antibiotics. We sought to compare heart rate (HR) and oxygenation (SpO2) patterns as well as baseline variables and clinical signs prompting sepsis work-ups ultimately determined to be late-onset sepsis (LOS) and sepsis ruled out (SRO). METHODS: At three NICUs, we reviewed records of very low birth weight (VLBW) infants around their first sepsis work-up diagnosed as LOS or SRO. Clinical signs prompting the evaluation were determined from clinician documentation. HR-SpO2 data, when available, were analyzed for mean, standard deviation, skewness, kurtosis, and cross-correlation. We used LASSO and logistic regression to assess variable importance and associations with LOS compared to SRO. RESULTS: We analyzed sepsis work-ups in 408 infants (173 LOS, 235 SRO). Compared to infants with SRO, those with LOS were of lower GA and BW, and more likely to have a central catheter and mechanical ventilation. Clinical signs cited more often in LOS included hypotension, acidosis, abdominal distension, lethargy, oliguria, and abnormal CBC or CRP(p < 0.05). HR-SpO2 data were available in 266 events. Cross-correlation HR-SpO2 before the event was associated with LOS after adjusting for GA, BW, and postnatal age. A model combining baseline, clinical and HR-SpO2 variables had AUC 0.821. CONCLUSION: In VLBW infants at 3-NICUs, we describe the baseline, clinical, and HR-SpO2 variables associated with LOS versus SRO.

A multicentre, open-label, follow-on study to assess the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain.

Peripheral neuropathic pain (PNP) poses a significant clinical challenge. The long-term efficacy of delta-9-tetrahydrocannabinol (THC)/cannabidiol (CBD) oromucosal spray was investigated in this 38-week open-label extension study. In total, 380 patients with PNP associated with diabetes or allodynia entered this study from two parent randomised, controlled trials. Patients received THC/CBD spray for a further 38 weeks in addition to their current analgesic therapy. Neuropathic pain severity was the primary efficacy measure using a pain 0-10 numerical rating scale (NRS). Additional efficacy, safety and tolerability outcomes were also investigated. In total, 234 patients completed the study (62 %). The pain NRS showed a decrease in score over time in patients from a mean of 6.9 points (baseline in the parent studies) to a mean of 4.2 points (end of open-label follow-up). The proportion of patients who reported at least a clinically relevant 30 % improvement in pain continued to increase with time (up to 9 months); at least half of all patients reported a 30 % improvement at all time points. Improvements were observed for all secondary efficacy outcomes, including sleep quality 0-10 NRS scores, neuropathic pain scale scores, subject global impression of change and EQ-5D questionnaire scores. THC/CBD spray was well tolerated for the study duration and patients did not seek to increase their dose with time, with no new safety concerns arising from long-term use. In this previously difficult to manage patient population, THC/CBD spray was beneficial for the majority of patients with PNP associated with diabetes or allodynia.

A double-blind, randomized, placebo-controlled, parallel group study of THC/CBD spray in peripheral neuropathic pain treatment.

BACKGROUND: Peripheral neuropathic pain (PNP) associated with allodynia poses a significant clinical challenge. The efficacy of Δ(9) -tetrahydrocannabinol/cannabidiol (THC/CBD) oromucosal spray, a novel cannabinoid formulation, was investigated in this 15-week randomized, double-blind, placebo-controlled parallel group study. METHODS: In total, 303 patients with PNP associated with allodynia were screened; 128 were randomized to THC/CBD spray and 118 to placebo, in addition to their current analgesic therapy. The co-primary efficacy endpoints were the 30% responder rate in PNP 0-10 numerical rating scale (NRS) score and the mean change from baseline to the end of treatment in this score. Various key secondary measures of pain and functioning were also investigated. RESULTS: At the 30% responder level, there were statistically significant treatment differences in favour of THC/CBD spray in the full analysis (intention-to-treat) dataset [p = 0.034; 95% confidence interval (CI): 1.05-3.70]. There was also a reduction in mean PNP 0-10 NRS scores in both treatment groups that was numerically higher in the THC/CBD spray group, but which failed to reach statistical significance. Secondary measures of sleep quality 0-10 NRS score (p = 0.0072) and Subject Global Impression of Change (SGIC) (p = 0.023) also demonstrated statistically significant treatment differences in favour of THC/CBD spray treatment. CONCLUSIONS: These findings demonstrate that, in a meaningful proportion of otherwise treatment-resistant patients, clinically important improvements in pain, sleep quality and SGIC of the severity of their condition are obtained with THC/CBD spray. THC/CBD spray was well tolerated and no new safety concerns were identified.

A double-blind, randomized, placebo-controlled, parallel-group study of THC/CBD oromucosal spray in combination with the existing treatment regimen, in the relief of central neuropathic pain in patients with multiple sclerosis.

Central neuropathic pain (CNP) occurs in many multiple sclerosis (MS) patients. The provision of adequate pain relief to these patients can very difficult. Here we report the first phase III placebo-controlled study of the efficacy of the endocannabinoid system modulator delta-9-tetrahydrocannabinol (THC)/cannabidiol (CBD) oromucosal spray (USAN name, nabiximols; Sativex, GW Pharmaceuticals, Salisbury, Wiltshire, UK), to alleviate CNP. Patients who had failed to gain adequate analgesia from existing medication were treated with THC/CBD spray or placebo as an add-on treatment, in a double-blind manner, for 14 weeks to investigate the efficacy of the medication in MS-induced neuropathic pain. This parallel-group phase of the study was then followed by an 18-week randomized-withdrawal study (14-week open-label treatment period plus a double-blind 4-week randomized-withdrawal phase) to investigate time to treatment failure and show maintenance of efficacy. A total of 339 patients were randomized to phase A (167 received THC/CBD spray and 172 received placebo). Of those who completed phase A, 58 entered the randomized-withdrawal phase. The primary endpoint of responder analysis at the 30 % level at week 14 of phase A of the study was not met, with 50 % of patients on THC/CBD spray classed as responders at the 30 % level compared to 45 % of patients on placebo (p = 0.234). However, an interim analysis at week 10 showed a statistically significant treatment difference in favor of THC/CBD spray at this time point (p = 0.046). During the randomized-withdrawal phase, the primary endpoint of time to treatment failure was statistically significant in favor of THC/CBD spray, with 57 % of patients receiving placebo failing treatment versus 24 % of patients from the THC/CBD spray group (p = 0.04). The mean change from baseline in Pain Numerical Rating Scale (NRS) (p = 0.028) and sleep quality NRS (p = 0.015) scores, both secondary endpoints in phase B, were also statistically significant compared to placebo, with estimated treatment differences of -0.79 and 0.99 points, respectively, in favor of THC/CBD spray treatment. The results of the current investigation were equivocal, with conflicting findings in the two phases of the study. While there were a large proportion of responders to THC/CBD spray treatment during the phase A double-blind period, the primary endpoint was not met due to a similarly large number of placebo responders. In contrast, there was a marked effect in phase B of the study, with an increased time to treatment failure in the THC/CBD spray group compared to placebo. These findings suggest that further studies are required to explore the full potential of THC/CBD spray in these patients.

Association between socioeconomic status indicators and obesity in adolescent students in Botswana, an African country in rapid nutrition transition.

OBJECTIVE: The purpose of this study was to examine two separate socioeconomic status (SES) indicators of obesity in Botswana, an African country that has experienced rapid economic development and where the prevalence of human immunodeficiency virus/acquired immune deficiency syndrome is high. METHODS: We conducted a nationally representative, cross-sectional study of 707 adolescent secondary school students in Botswana. Measured height and weight were used to compute World Health Organization age- and sex-specific body mass index z-scores. SES was described by private vs. public school attendance and a survey of assets/facilities within the home. RESULTS: Overall, private school students and those with more assets had a higher prevalence of overweight and obesity than public school students (private: 27.1%, 95% confidence interval [CI]: 20.4-34.5; public: 13.1%, 95% CI: 9.8-16.8) and those with fewer assets (more assets: 20.0%, 95% CI: 16.0-24.4; fewer assets: 11.2%, 95% CI: 6.6-16.9). CONCLUSIONS: Public health interventions in developing countries may need to be targeted differently to low or high SES individuals in order to treat already high obesity rates in higher SES groups and to prevent the development of obesity in lower SES communities undergoing economic transition.

A placebo-controlled, parallel-group, randomized withdrawal study of subjects with symptoms of spasticity due to multiple sclerosis who are receiving long-term Sativex® (nabiximols).

BACKGROUND: Open-label studies are not ideal for providing robust evidence for long-term maintenance of efficacy of medicines, especially where medicines provide symptom relief and where long-term use of a placebo may be problematic and not ethical. OBJECTIVE: To evaluate the maintenance of efficacy of Sativex in subjects who have gained long-term symptomatic relief of spasticity in multiple sclerosis (MS), and to assess the impact of sudden medicine withdrawal. METHODS: An enriched enrolment randomized withdrawal study design was used. Eligible subjects with ongoing benefit from Sativex for at least 12 weeks entered this 5-week placebo-controlled, parallel-group, randomized withdrawal study. Each subjects' previous effective and tolerated dose was continued. RESULTS: A total of 18 subjects per group were enrolled. Demographics showed a mean duration of MS of 16.4 years, spasticity 12.7 years, mean duration of Sativex use of 3.6 years (median 3.4 years) and a mean daily dose of 8.25 sprays. Primary outcome of time to treatment failure was significantly in favour of Sativex (p = 0.013). Secondary endpoints showed significant changes in the Carer and Subject's Global Impression of Change scales in favour of Sativex. CONCLUSIONS: Maintenance of Sativex efficacy in long-term symptomatic improvement of spasticity to a group of subjects with MS has been confirmed using this study design.

A randomized, double-blind, placebo-controlled, parallel-group, enriched-design study of nabiximols* (Sativex(®) ), as add-on therapy, in subjects with refractory spasticity caused by multiple sclerosis.

BACKGROUND: Spasticity is a disabling complication of multiple sclerosis, affecting many patients with the condition. We report the first Phase 3 placebo-controlled study of an oral antispasticity agent to use an enriched study design. METHODS: A 19-week follow-up, multicentre, double-blind, randomized, placebo-controlled, parallel-group study in subjects with multiple sclerosis spasticity not fully relieved with current antispasticity therapy. Subjects were treated with nabiximols, as add-on therapy, in a single-blind manner for 4weeks, after which those achieving an improvement in spasticity of ≥20% progressed to a 12-week randomized, placebo-controlled phase. RESULTS: Of the 572 subjects enrolled, 272 achieved a ≥20% improvement after 4weeks of single-blind treatment, and 241 were randomized. The primary end-point was the difference between treatments in the mean spasticity Numeric Rating Scale (NRS) in the randomized, controlled phase of the study. Intention-to-treat (ITT) analysis showed a highly significant difference in favour of nabiximols (P=0.0002). Secondary end-points of responder analysis, Spasm Frequency Score, Sleep Disturbance NRS Patient, Carer and Clinician Global Impression of Change were all significant in favour of nabiximols. CONCLUSIONS: The enriched study design provides a method of determining the efficacy and safety of nabiximols in a way that more closely reflects proposed clinical practice, by limiting exposure to those patients who are likely to benefit from it. Hence, the difference between active and placebo should be a reflection of efficacy and safety in the population intended for treatment.

A double-blind, randomized, placebo-controlled, parallel-group study of Sativex, in subjects with symptoms of spasticity due to multiple sclerosis.

BACKGROUND: Muscle spasticity is common in multiple sclerosis (MS), occurring in more than 60% of patients. OBJECTIVE: To compare Sativex with placebo in relieving symptoms of spasticity due to MS. METHODS: A 15-week, multicenter, double-blind, randomized, placebo-controlled, parallel-group study in 337 subjects with MS spasticity not fully relieved with current anti-spasticity therapy. RESULTS: The primary endpoint was a spasticity 0-10 numeric rating scale (NRS). Intention-to-treat (ITT) analysis showed a non-significant improvement in NRS score, in favor of Sativex. The per protocol (PP) population (79% of subjects) change in NRS score and responder analyses (> or =30% improvement from baseline) were both significantly superior for Sativex, compared with placebo: -1.3 versus -0.8 points (change from baseline, p=0.035); and 36% versus 24% (responders, p=0.040). These were supported by the time to response (ITT: p=0.068; PP: p=0.025) analyses, carer global impression of change assessment (p=0.013) and timed 10-meter walk (p=0.042). Among the subjects who achieved a > or =30% response in spasticity with Sativex, 98, 94 and 73% reported improvements of 10, 20 and 30%, respectively, at least once during the first 4 weeks of treatment. Sativex was generally well tolerated, with most adverse events reported being mild-to-moderate in severity. DISCUSSION AND CONCLUSIONS: The 0-10 NRS and responder PP analyses demonstrated that Sativex treatment resulted in a significant reduction in treatment-resistant spasticity, in subjects with advanced MS and severe spasticity. The response observed within the first 4 weeks of treatment appears to be a useful aid to prediction of responder/non-responder status.

Antidepressants that inhibit neuronal norepinephrine reuptake are not associated with increased spontaneous reporting of cardiomyopathy.

A recent literature review linked norepinephrinergic stimulation to alterations in cyclic adenosine monophosphate (cAMP)-mediated signaling in cardiac myocytes and suggested that this might contribute to the pathological mechanisms that lead to chamber enlargement and hypocontractility, which are seen in dilated cardiomyopathy. This accompanies a large body of literature linking cardiac sympathetic outflow activation in early heart failure with progressive myocyte deterioration. As the mode of action of a number of antidepressants involves the inhibition of neuronal norepinephrine reuptake to varying degrees, this study was conducted to assess whether such agents might be associated with disproportionate reporting of cardiomyopathy. Limited data exist specifically examining the association between the antidepressant use and the cardiomyopathy. Using a data mining algorithm (DMA), we quantitatively investigated the association between antidepressant agents that predominantly exert their effects through inhibiting neuronal norepinephrine reuptake (rather than serotonin) and cardiomyopathy. We retrospectively applied a Bayesian DMA, the Bayesian Confidence Propagation Neural Network, to the cumulative reports in the Food and Drug Administration Adverse Event Reporting System (through the fourth quarter of 2006) and World Health Organization Vigibase (through the second quarter of 2007) databases. A threshold of the posterior interval 95% lower limit > 0 was used to define a signal of disproportionate reporting with individual or groups of antidepressants and cardiomyopathy-related terms. The analysis suggested that there is no direct relationship between antidepressants with greater norepinephrine reuptake inhibitor activity (affinity for norepinephrine reuptake transporter or selectivity for norepinephrine versus serotonin) and reporting of cardiomyopathy. In contrast, an inverse correlation might exist with a higher number of cases identified with tricyclic antidepressants showing lower norepinephrine reuptake inhibition and the serotonin/norepinephrine reuptake inhibitors as well as with serotonin/ norepinephrine/slight dopamine reuptake inhibitor.

The quest for Factor VIIa exosite inhibitors.

Coagulation proteases are involved in a highly orchestrated proteolytic cascade which is essential for haemostasis and blood clotting. In particular, the initiator of the coagulation cascade, Factor VIIa, binds to its cofactor, tissue factor, and its substrate, Factor X, via exosite interactions to form a ternary catalytic complex named extrinsic Xase. These exosite interactions have also been shown to allosterically induce the active conformation of the catalytic site of Factor VIIa. We have developed a direct continuous fluorescence polarization-based extrinsic Xase assay, which has been used to screen in excess of 1 million structurally diverse low-molecular-mass compounds as a potential starting point for the development of anticoagulants. The primary screen hits were categorized with deconvolution assays into either active-site or exosite inhibitors. The latter category of hits displayed both competitive and uncompetitive modalities of inhibition with respect to Factor X activation. An uncompetitive mechanism of action is of particular interest as it offers a hypothetical inhibitory advantage in the context of inhibiting a proteolytic cascade such as the blood coagulation pathway.

Randomized controlled trial of cannabis-based medicine in spasticity caused by multiple sclerosis.

Symptoms relating to spasticity are common in multiple sclerosis (MS) and can be difficult to treat. We have investigated the efficacy, safety and tolerability of a standardized oromucosal whole plant cannabis-based medicine (CBM) containing delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD), upon spasticity in MS. A total of 189 subjects with definite MS and spasticity were randomized to receive daily doses of active preparation (n = 124) or placebo (n = 65) in a double blind study over 6 weeks. The primary endpoint was the change in a daily subject-recorded Numerical Rating Scale of spasticity. Secondary endpoints included a measure of spasticity (Ashworth Score) and a subjective measure of spasm. The primary efficacy analysis on the intention to treat (ITT) population (n = 184) showed the active preparation to be significantly superior (P = 0.048). Secondary efficacy measures were all in favour of active preparation but did not achieve statistical significance. The responder analysis favoured active preparation, 40% of subjects achieved >30% benefit (P = 0.014). Eight withdrawals were attributed to adverse events (AEs); six were on active preparation and two on placebo. We conclude that this CBM may represent a useful new agent for treatment of the symptomatic relief of spasticity in MS.

Absence of genetic divergence between western corn rootworms (Coleoptera: Chrysomelidae) resistant and susceptible to control by crop rotation.

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of corn, Zea mays L., in North America that has recently invaded Europe. A loss of ovipositional fidelity to cornfields has allowed the species to circumvent crop rotation as a means of control in part of its range in the United States. Analyses of variation at eight microsatellite loci provided no evidence for general genetic differentiation between samples of western corn rootworm collected in soybean, Glycine max (L.) Merr., fields and those collected in cornfields both inside and outside the rotation-resistance problem area. This result suggests that few or no barriers to gene flow exist between rotation-resistant and -susceptible rootworm populations. The implications of this result for the management of western corn rootworm in North America and Europe are discussed.

Analysis of the dynamics of adaptation to transgenic corn and crop rotation by western corn rootworm (Coleoptera: Chrysomelidae) using a daily time-step model.

Western corn rootworm, Diabrotica virgifera virgifera LeConte, has overcome crop rotation in several areas of the north central United States. The effectiveness of crop rotation for management of corn rootworm has begun to fail in many areas of the midwestern United States, thus new management strategies need to be developed to control rotation-resistant populations. Transgenic corn, Zea mays L., effective against western corn rootworm, may be the most effective new technology for control of this pest in areas with or without populations adapted to crop rotation. We expanded a simulation model of the population dynamics and genetics of the western corn rootworm for a landscape of corn; soybean, Glycine max (L.); and other crops to study the simultaneous development of resistance to both crop rotation and transgenic corn. Results indicate that planting transgenic corn to first-year cornfields is a robust strategy to prevent resistance to both crop rotation and transgenic corn in areas where rotation-resistant populations are currently a problem or may be a problem in the future. In these areas, planting transgenic corn only in continuous cornfields is not an effective strategy to prevent resistance to either trait. In areas without rotation-resistant populations, gene expression of the allele for resistance to transgenic corn, R, is the most important factor affecting the evolution of resistance. If R is recessive, resistance can be delayed longer than 15 yr. If R is dominant, resistance may be difficult to prevent. In a sensitivity analysis, results indicate that density dependence, rotational level in the landscape, and initial allele frequency are the three most important factors affecting the results.

Evaluation of a commercial ELISA for detecting Norwalk-like virus antigen in faeces.

A commercially available enzyme immunoassay, the IDEIA Norwalk-like virus (NLV) enzyme linked immunosorbent assay (ELISA; Dako Cytomation, Ely, UK) for detecting NLV antigen in faecal samples and determining the NLV genogroup was evaluated. The performance of the ELISA was compared with that of electron microscopy and the reverse transcription polymerase chain reaction by testing a panel of faecal samples collected from patients involved in outbreaks of gastroenteritis. When compared with reverse transcription-polymerase chain reaction (RT-PCR), the ELISA had a sensitivity and specificity of 55.5 and 98.3%, respectively. This compares with a sensitivity and specificity for EM of 23.9 and 99.2%, respectively. The sensitivity and specificity of the ELISA for determining the aetiology of a Norwalk virus-like outbreak, based on two or more positive samples within an outbreak, were 52.2 and 100% when two samples were collected from an outbreak and 71.4 and 100% when six or more samples were collected. The ELISA correctly identified the NLV genogroups of viruses previously characterised by partial DNA sequencing. The ELISA is a suitable alternative to the preliminary screening by EM for investigating outbreaks of gastroenteritis. Outbreaks, negative by ELISA should be examined by RT-PCR in order to detect strains non-reactive in the assay and virus strains from representative ELISA positive outbreaks should be characterised fully to allow the genetic diversity of NLVs co-circulating in the population to be described.

Assessing non-linear estimation procedures for human growth models.

BACKGROUND: In the last 20 years several non-linear models with a relatively small number of parameters have provided useful descriptions of the complete human growth curve. However, some aspects of the estimation procedures used have not been properly studied, e.g. estimation of biases, measures of non-linearity, and the possibility of autocorrelated errors and heteroscedasticity. OBJECTIVES: To present a detailed analysis of these aspects for five well-known non-linear models (Preece-Baines, Shohoji-Sasaki and three models proposed by Jolicoeur et al.) and a large data set (the MRC Edinburgh Longitudinal Study). SUBJECTS: A cohort of 74 females and 103 males collected for the Edinburgh Longitudinal Study for the MRC Human Genetics Unit, Edinburgh, UK, comprising approximately quarterly height measurements for small ages and semestral height measurements for the remaining ages up to the early twenties. RESULTS: We found little evidence of extreme curvature and relatively small, cyclical patterns in the residuals. The estimates obtained with ordinary non-linear least squares were very close to those obtained with more complicated estimation procedures. CONCLUSIONS: The five models studied are reasonably robust against most of the problems encountered when fitting non-linear models to human growth data; this confirms some conjectures which have been taken for granted by a large number of authors. The presence of cyclical patterns is a consequence of the global description of growth attempted by these five models.

Characterization of the glycosylation profiles of Alzheimer's beta -secretase protein Asp-2 expressed in a variety of cell lines.

Amyloid 39-42 beta -peptides are the main components of amyloid plaques found in the brain of Alzheimer's disease patients. Amyloid 39-42 beta-peptide is formed from amyloid precursor protein by the sequential action of beta- and gamma-secretases. Asp-2 is a transmembrane aspartic protease expressed in the brain, shown to have beta-secretase activity. Mature Asp-2 has four N-glycosylation sites. In this report we have characterized the carbohydrate structures in this glycoprotein expressed in three different cell lines, namely Chinese hamster ovary, CV-1 origin of SV40, and baculovirus-infected SF9 cells. Biantennary and triantennary oligosaccharides of the "complex" type were released from glycoprotein expressed in the mammalian cells, whereas mannose-rich glycans were identified from glycoprotein synthesized in the baculovirus-infected cells. Site-directed mutagenesis of the asparagine residues at amino acid positions 153, 172, 223, and 354 demonstrate that the protease activity of Asp-2 is dependent on its glycosylation.

Predicting western corn rootworm (Coleoptera: Chrysomelidae) larval injury to rotated corn with Pherocon AM traps in soybeans.

Crop rotation for portions of east central Illinois and northern Indiana no longer adequately protects corn (Zea mays L.) roots from western corn rootworm, Diabrotica virgifera virgifera LeConte. Seventeen growers in east central Illinois monitored western corn rootworm adults in soybean (Glycine max L.) fields with unbaited Pherocon AM traps during 1996 and 1997. In the following years (1997 and 1998), growers left untreated strips (no insecticide applied) when these fields were planted with corn. Damage to rotated corn by rootworms was more severe in untreated than in treated strips of rotated corn, ranging from minor root scarring to a full node of roots pruned. Densities of western corn rootworms in soybean fields from 1996 were significantly correlated with root injury to rotated corn the following season. Adult densities from 1997 were not significantly correlated with root injury in 1998, due to heavy precipitation throughout the spring of 1998 and extensive larval mortality. Twenty-eight additional growers volunteered in 1998 to monitor rootworm adults in soybean fields with Pherocon AM traps based on recommendations that resulted from our research efforts in 1996 and 1997. In 1999, these 28 fields were rotated to corn, and rootworm larval injury was measured in untreated strips. Based on 1996-1997 and 1998-1999 data, a regression analysis revealed that 27% of the variation in root injury to rotated corn could be explained by adult density in soybeans the previous season. We propose a sampling plan for soybean fields and a threshold for predicting western corn rootworm larval injury to rotated corn.

ASP1 (BACE2) cleaves the amyloid precursor protein at the beta-secretase site.

Sequential proteolytic processing of the Amyloid Precursor Protein (APP) by beta- and gamma-secretases generates the 4-kDa amyloid (A beta) peptide, a key component of the amyloid plaques seen in Alzheimer's disease (AD). We and others have recently reported the identification and characterisation of an aspartic proteinase, Asp2 (BACE), as beta-secretase. Here we describe the characterization of a second highly related aspartic proteinase, Asp1 as a second beta-secretase candidate. Asp1 is expressed in brain as detected at the mRNA level and at the protein level. Transient expression of Asp1 in APP-expressing cells results in an increase in the level of beta-secretase-derived soluble APP and the corresponding carboxy-terminal fragment. Paradoxically there is a decrease in the level of soluble A beta secreted from the cells. Asp1 colocalizes with APP in the Golgi/endoplasmic reticulum compartments of cultured cells. Asp1, when expressed as an Fc fusion protein (Asp1-Fc), has the N-terminal sequence ALEP..., indicating that it has lost the prodomain. Asp1-Fc exhibits beta-secretase activity by cleaving both wild-type and Swedish variant (KM/NL) APP peptides at the beta-secretase site.

Characterization of the binding of [(125)I]-human prolactin releasing peptide (PrRP) to GPR10, a novel G protein coupled receptor.

GPR10 is a novel G-protein coupled receptor that is the human orthologue of rat Unknown Hypothalamic Receptor-1 (UHR-1). Human prolactin-releasing peptide (PrRP) has been identified as an endogenous ligand for GPR10, and occurs as 31 and 20 amino acid forms. The present study characterizes the binding of [(125)I]-PrRP-20 to HEK293 cells stably expressing GPR10 receptors. Specific binding of [(125)I]-PrRP-20 was saturable, and analysis suggested evidence of both high and low affinity sites, with K:(D:) values of 0.026+/-0.006 and 0.57+/-0.14 nM respectively, and B(max) values of 3010+/-400 and 8570+/-2240 fmol mg protein(-1) respectively. Kinetic studies were unable to distinguish two sites, but single site analysis of association and dissociation data produced a K:(D:) of 0.012 nM. Competition studies revealed that human and rat PrRP-20 and PrRP-31 all display high affinity for GPR10. A range of other drugs which are known ligands at receptors which share limited homology with GPR10 were also tested. None of the drugs tested, including the RF-amide neuropeptide FF, demonstrated any affinity for GPR10. Human PrRP-20 failed to alter basal or forskolin-stimulated levels of intracellular cyclic AMP in HEK293-GPR10 cells, suggesting that GPR10 does not couple via either G(s) or G(i). Functional studies using measurements of intracellular calcium confirmed that human and rat PrRP-20 and PrRP-31 are all potent, full agonists at the GPR10 receptor. The response was blocked both by thapsigargin, indicating mobilization of intracellular Ca(2+) stores. These studies indicate that [(125)I]-PrRP-20 is a specific, high affinity radioligand for GPR10. The availability of this radioligand binding assay will be a valuable tool for the investigation of the key features involved in PrRP binding and studies on the localization and function of GPR10.

Criminality and antisocial behaviour in unselected men with sex chromosome abnormalities.

BACKGROUND: Previous studies on male patients with sex chromosome abnormalities (SCA), namely XYY and XXY, suggest that such patients commit criminal acts more frequently than expected. Most of these studies are affected by ascertainment bias. METHODS: Using a population-based sample of men with SCA, identified by screening 34380 infants at birth between 1967 and 1979, comparison between 16 XYY men, 13 XXY men and 45 controls were made in terms of frequency of antisocial personality disorder (APD) using the Schedule for Affective Disorders and Schizophrenia lifetime version. Rates of criminal convictions were examined in 17 XYY men, 17 XXY men and 60 controls. RESULTS: XYY males showed a significantly higher frequency of antisocial behaviour in adolescence and adulthood and of criminal convictions than the controls, but multiple regression analysis showed this to be mediated mainly through lowered intelligence. Property offences constituted the majority of offences in all groups. The XXY men did not show an increased rate of criminal convictions. It is possible that this apparently negative result relates to the relatively small numbers of cases and hence low power of this study. CONCLUSIONS: The findings of this study carry the advantage of not being affected by ascertainment bias and the disadvantage of having low power. It provides evidence for a slightly increased liability to antisocial behaviour in XYY men.