Molecular diversity of soil and marine 16S rRNA gene sequences related to beta-subgroup ammonia-oxidizing bacteria

We have conducted a preliminary phylogenetic survey of ammonia-oxidizing beta-proteobacteria, using 16S rRNA gene libraries prepared by selective PCR and DNA from acid and neutral soils and polluted and nonpolluted marine sediments. Enrichment cultures were established from samples and analyzed by PCR. Analysis of 111 partial sequences of c. 300 bases revealed that the environmental sequences formed seven clusters, four of which are novel, within the phylogenetic radiation defined by cultured autotrophic ammonia oxidizers. Longer sequences from 13 cluster representatives support their phylogenetic positions relative to cultured taxa. These data suggest that known taxa may not be representative of the ammonia-oxidizing beta-proteobacteria in our samples. Our data provide further evidence that molecular and culture-based enrichment methods can select for different community members. Most enrichments contained novel Nitrosomonas-like sequences whereas novel Nitrosospira-like sequences were more common from gene libraries of soils and marine sediments. This is the first evidence for the occurrence of Nitrosospira-like strains in marine samples. Clear differences between the sequences of soil and marine sediment libraries were detected. Comparison of 16S rRNA sequences from polluted and nonpolluted sediments provided no strong evidence that the community composition was determined by the degree of pollution. Soil clone sequences fell into four clusters, each containing sequences from acid and neutral soils in varying proportions. Our data suggest that some related strains may be present in both samples, but further work is needed to resolve whether there is selection due to pH for particular sequence types.

Phylogenetic differences between particle-associated and planktonic ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria in the Northwestern Mediterranean Sea

The aim of this study was to determine if there were differences between the types of ammonia-oxidizing bacteria of the beta subdivision of the class Proteobacteria associated with particulate material and planktonic samples obtained from the northwestern Mediterranean Sea. A nested PCR procedure performed with ammonia oxidizer-selective primers was used to amplify 16S rRNA genes from extracted DNA. The results of partial and full-length sequence analyses of 16S rRNA genes suggested that different groups of ammonia-oxidizing bacteria were associated with the two sample types. The particle-associated sequences were predominantly related to Nitrosomonas eutropha, while the sequences obtained from the planktonic samples were related to a novel marine Nitrosospira group (cluster 1) for which there is no cultured representative yet. A number of oligonucleotide probes specific for different groups of ammonia oxidizers were used to estimate the relative abundance of sequence types in samples of clone libraries. The planktonic libraries contained lower proportions of ammonia oxidizer clones (0 to 26%) than the particulate material libraries (9 to 83%). Samples of the planktonic and particle-associated libraries showed that there were depth-related differences in the ammonia oxidizer populations, with the highest number of positive clones in the particle-associated sample occurring at a depth of 700 m. The greatest difference between planktonic and particle-associated populations occurred at a depth of 400 m, where only 4% of the clones in the planktonic library were identified as Nitrosomonas clones, while 96% of these clones were identified as clones that were related to the marine Nitrosospira species. Conversely, all ammonia oxidizer-positive clones obtained from the particle-associated library were members of the Nitrosomonas group. This is the first indication that Nitrosomonas species and Nitrosospira species may occupy at least two distinct environmental niches in marine environments. The occurrence of these groups in different niches may result from differences in physiological properties and, coupled with the different environmental conditions associated with these niches, may lead to significant differences in the nature and rates of nitrogen cycling in these environments.

Insulin resistance, diabetes, and risk markers for ischaemic heart disease in Asian men and non-Asian in Bradford

OBJECTIVE

To examine the hypothesis, in a community not studied before, that insulin resistance associated with centralised adiposity is the mechanism underlying the predisposition of Asian immigrant communities to both ischaemic heart disease and diabetes mellitus.

DESIGN

Cross sectional study within one socioeconomic stratum.

SETTING

Two factories in the textile sector in Bradford, West Yorkshire.

SUBJECTS

Male manual workers of Asian (110) and non-Asian origin (156) aged 20-65 years.

RESULTS

Diabetes was almost three times more prevalent in the Asian group. Two hours after an oral glucose load Asian men had double the serum insulin concentrations of non-Asian men (p < 0.0001). Asian men also had significantly lower concentrations of plasma total cholesterol (p < 0.03), high density lipoprotein cholesterol (HDL) (HDL2, p < 0.0001; HDL3, p < 0.0001), and apolipoprotein AI (p < 0.0001). Fasting plasma triglyceride concentrations were slightly higher (p = 0.072) in the Asian men; thus the ratio of triglyceride cholesterol was higher (p = 0.006). The inter-relation between serum insulin and plasma lipid concentrations indicated metabolic differences between the ethnic groups. Insulin concentrations were associated with cholesterol concentrations in the Asian men only and there was a lack of association between triglyceride, low density lipoprotein cholesterol, and HDL cholesterol in this group. The risk marker profile in the Asian men was therefore quite different to that of their non-Asian counterparts and was associated with a greater tendency to centralised adiposity.

CONCLUSION

These data support the insulin resistance hypothesis and thus have important implications for strategies for the prevention of heart disease in Asian communities in the United Kingdom.

Structure, expression, and molecular mapping of a divergent member of the class I HLA gene family

A class I gene distinct from HLA-A, -B, or -C was identified in a cosmid clone and transfected into mouse L cells. The gene, placed adjacent to the polyoma enhancer, produced a full-length class I mRNA and high levels of a 43-kDa protein in the cytoplasm. The surface expression of the gene product required its association with human beta 2-microglobulin. The protein was recognized by a xenoantiserum raised against a mixture of human B- and T-cell lines. The product was also serologically reactive with the HLA framework monoclonal antibodies. The complete nucleotide sequence of the gene was determined and a specific oligonucleotide probe was synthesized. This probe was used to identify a full-length mRNA transcript in a B-lymphoblastoid cell line (JY). The gene was mapped within a 190-kilobase Not I restriction fragment located in the telomeric portion of the human major histocompatibility complex. Distinct features of the gene include the structure of the promoter, the position of the translation initiation site, a frameshift mutation at the carboxyl terminus, the insertion of an Alu repeat element in the eighth exon, divergence in the derived amino acid sequence, and the lack of expression of the gene in some cells.

Developmental and experimental changes in dendritic symmetry in n. laminaris of the chick

Early acoustic experience affects the structure of neurons in the brainstem of young chickens. In the binaurally innervated cells of the nucleus laminaris the symmetry of the dorsal and ventral dendritic trees normally increases during the embryonic and early postnatal period. Unilateral ear plugs disrupt that development. This study shows that balanced stimulation plays an important role in the development of symmetrical neuronal structures in the central auditory pathway.

Synthesis and antineoplastic properties of ether-linked thioglycolipids

Ether-linked glycero-alpha- and beta-D-glucopyranosides and glycero-1-thio-alpha- and beta-D-glucopyranosides have been synthesized by modifications of the Königs-Knorr procedure, and their antitumor activities have been evaluated. The bioactivities of these compounds have been evaluated in five different cell lines (WEHI 3B, C653, X63/OMIL3, R6X-B15, and HL-60) and compared with the activities of 1-O-hexadecyl-2-O-methyl-sn-3-glycerophosphocholine (GPC) and its enantiomer, 3-O-hexadecyl-2-O-methyl-sn-1-GPC. The results indicate that a alpha-D-thioglucopyranoside [1-O-hexadecyl-2-O-methyl-3-S-(alpha-D-1'- thioglucopyranosyl-sn-glycerol)] is selective with respect to its action on target cells, with high activity for killing of WEHI 3B and C653 cells as determined by inhibition of [3H]thymidine incorporation into DNA and HL-60 cell cytotoxicity, but unable to induce aggregation of rabbit platelets at 10(-5) M. The corresponding beta-linked thioglycolipid was ineffective with respect to cytotoxicity against each cell line tested, indicating the importance of configuration at the anomeric position; the beta-thioglycoside was also ineffective with respect to inducing platelet aggregation. 1-O-Hexadecyl-2-O-methyl-sn-3-GPC and 3-O-hexadecyl-2-O-methyl-sn-1-GPC were potent inhibitors of growth of each cell line tested but also caused rabbit platelet aggregation at concentrations greater than or equal to 10(-7) M. Thus, 3-S-(alpha-thioglycopyranosyl)-sn- glycerols bearing a long-chain O-alkyl group at the sn-1 position and a methoxy group at the sn-2 position of glycerol appear to be a promising class of antineoplastic agents with lower risk of inducing thrombosis than the widely studied platelet activating factor analogue, 1-O-octadecyl-2-O-methyl-rac-3-GPC.

Body composition at high altitude: a randomized placebo-controlled trial of dietary carbohydrate supplementation

BACKGROUND

Body mass loss is inevitable with chronic hypoxic exposure. However, the exact body-composition changes, their causes, and possible treatments remain unknown.

OBJECTIVE

The objective was to investigate body composition during a high-altitude expedition by using non-empirically derived methods, experimentally manipulating energy intake, and investigating the influence of initial body composition.

DESIGN

Forty-one participants completed a 21-d expedition in the Himalayas. Energy intake was manipulated with a double-blind, placebo-controlled, randomized trial of carbohydrate energy supplementation. Body composition was assessed before and after the expedition by using a 4-component model including fat mass, total body water, bone mineral mass, and residual mass (principally protein and glycogen). Data were analyzed by repeated-measures analysis of variance.

RESULTS

Participants allocated to receive carbohydrate were given an additional 15,058 +/- 6211 kcal over the 21-d expedition (>6 kcal x kg(-1) x d(-1)). Nevertheless, the functionally important residual mass decreased in both groups by 6% (main effect of time: P = 0.021), with no effect of allocation (interaction effect: P = 0.116). Similar decreases were observed for fat mass (11%) and total body water (3%), which were also unabated by allocation. Furthermore, high initial fat mass (by median split) did not preserve residual mass (high-fat compared with low-fat participants: residual loss = 5% compared with 8%; P = 0.990).

CONCLUSIONS

High-altitude exposure decreased body mass, including the functionally important residual component. These losses were not abated by increasing energy intake or an initially high fat mass. Factors other than negative energy balance must contribute to body-composition changes with chronic hypoxia. This trial was registered at clinicaltrials.gov as NCT00731510.

Functional characterization of four metallothionein genes in Daphnia pulex exposed to environmental stressors

We characterized the metallothionein genes (Mt1, Mt2, Mt3, and Mt4) in Daphnia pulex on both molecular and ecotoxicological level. We therefore conducted a bioinformatical analysis of the gene location and predicted protein sequence, and screened the upstream flanking region for regulatory elements. The number of these elements and their positions relative to the start codon varied strongly among the four genes and even among two gene duplicates (Mt1A and Mt1B), suggesting different roles of the four proteins in the organisms' response to stress. We subsequently conducted a chronic 16-day exposure of D. pulex to different environmental stressors (at sublethal levels causing approximately 50% reduction in reproduction). Based on prior knowledge, we exposed them to the metals Cd, Cu, and Ni, the moulting hormone hydroxyecdysone (20E), and the oxidative stressors cyanobacteria (Microcystis aeruginosa), and paraquat (Pq). We then compared mRNA expression levels of the four Mt genes under these stress conditions with control conditions in "The Chosen One" clone (TCO), for which the full genome was sequenced and annotated. All together, the mRNA expression results under the different stress regimes indicate that different Mt genes may play different and various roles in the response of D. pulex to stress and that some (but not all) of the differences among the four genes could be related to the pattern of regulatory elements in their upstream flanking region.

Protein-carbohydrate interaction. A turbidimetric study of the interaction of concanavalin A with amylopectin and glycogen and some of their enzymic and chemical degradation products

The interaction of the plant protein concanavalin A with glycogen and amylopectin was studied. The protein concentration-dependency of the interaction and the effect on the interaction of various enzymic and chemical degradations of the polysaccharides were investigated by using a turbidimetric technique. The results indicate that, in addition to certain structural requirements, the molecular weight of the polysaccharides and the concentration of protein are important factors controlling the extent of interaction. The observed similarity of the interaction of polysaccharides with concanavalin A to the more specific polysaccharide-protein interactions indicates that it should provide a useful model system for the study of these interactions in general.

Ethnic differences in risk markers for heart disease in Bradford and implications for preventive strategies

OBJECTIVES

To assess and compare the prevalence of established risk markers for ischaemic heart disease in a sample of Asian and non-Asian men and to relate these observations to preventive strategies.

SETTING

Two factories in the textile industry in Bradford, West Yorkshire, UK. Subjects--288 male manual workers aged 20 to 65 years.

DESIGN

Cross sectional study within one occupational/social class stratum.

MEASUREMENTS AND MAIN RESULTS

Age, body mass index, plasma lipids, fibrinogen and serum insulin values, blood pressure, smoking habits, alcohol consumption, and exercise routines were recorded. Plasma total cholesterol concentrations were significantly lower in Asian than non-Asian men (5.3 mmol/l v 5.8 mmol/l respectively, p < 0.0001), as were low density lipoprotein cholesterol concentrations (3.4 mmol/l v 3.7 mmol/l, p = 0.0150), and high density lipoprotein (HDL) cholesterol (1.1 mmol/l v 1.3 mmol/l, p < 0.0001). Hypercholesterolaemia (concentration > 6.5mM) was present in nearly one quarter of non-Asians but less than one eighth of Asian men. Triglyceride values were not significantly higher in Asians. Smoking rates were high in non-Asians (43.8%) and only slightly lower in Asians (39.1%). Asian smokers smoked fewer cigarettes per day on average (9.3 v 16.1, p = 0.0001). Almost a quarter of non-Asian men (23.1%) and 26.6% of Asian men had raised blood pressure. Systolic pressures were higher in non-Asian men (138.3 mmHg v 133.0 mmHg, p = 0.0070), but diastolic pressures showed no ethnic differences. Diabetes was more prevalent in Asian men (10.9% v 4.4% p < 0.05), who also showed higher serum insulin concentrations after glucose loading (22.3 mU/l v 10.2 mU/l, p < 0.0001). Plasma fibrinogen values were higher in non-Asian men (2.9 g/l v 2.6 g/l, p < 0.0001) and these were associated with smoking. Nearly all non-Asians (92.5%) consumed alcohol at some time whereas 62.5% of Asians habitually abstained from alcohol consumption. Among the drinkers, non-Asian men consumed on average, 23.9 units per week and Asian men 18.4 units per week (p = 0.083). The mean body mass index for Asian men was 24.5 kg/m2 which was not significantly different to the mean in non-Asian men (25.2 kg/m2). The frequency of exercise in leisure time was low in both groups with 44.4% of non-Asian and 21.1% of Asian men taking moderate exercise weekly, and even fewer, regular strenuous exercise (16.3% and 8.6% respectively).

CONCLUSIONS

The plasma cholesterol and fibrinogen concentrations, prevalence of hypertension, smoking habits, alcohol intakes, and infrequency of exercise in leisure time in these non-Asian men in Bradford were consistent with an increased risk of heart disease. The pattern of risk markers was clearly different in Asian men. Only their lower HDL cholesterol concentrations, marginally higher triglyceride values, higher prevalence of diabetes, and very low frequency of exercise in leisure time would be consistent with a higher risk of heart disease compared with non-Asians. The implications of these observations for heart disease preventive strategies are discussed.

Longitudinal evaluation of the importance of homework assignment completion for the academic performance of middle school students with ADHD

The primary goal of this study was to longitudinally evaluate the homework assignment completion patterns of middle school age adolescents with ADHD, their associations with academic performance, and malleable predictors of homework assignment completion. Analyses were conducted on a sample of 104 middle school students comprehensively diagnosed with ADHD and followed for 18 months. Multiple teachers for each student provided information about the percentage of homework assignments turned in at five separate time points and school grades were collected quarterly. Results showed that agreement between teachers with respect to students assignment completion was high, with an intraclass correlation of .879 at baseline. Students with ADHD were turning in an average of 12% fewer assignments each academic quarter in comparison to teacher-reported classroom averages. Regression analyses revealed a robust association between the percentage of assignments turned in at baseline and school grades 18 months later, even after controlling for baseline grades, achievement (reading and math), intelligence, family income, and race. Cross-lag analyses demonstrated that the association between assignment completion and grades was reciprocal, with assignment completion negatively impacting grades and low grades in turn being associated with decreased future homework completion. Parent ratings of homework materials management abilities at baseline significantly predicted the percentage of assignments turned in as reported by teachers 18 months later. These findings demonstrate that homework assignment completion problems are persistent across time and an important intervention target for adolescents with ADHD.

Impact of experimentally manipulated sleep on adolescent simulated driving

OBJECTIVE/BACKGROUND

Sleep restriction (SR) impairs adolescents' attention, which could contribute to high rates of driving crashes. Here, we examine the impact of experimental SR on adolescent drivers, considering whether that impact is moderated by the nature of the drive (urban/suburban vs. rural) or how vulnerable each adolescent is to attentional decline after SR.

PARTICIPANTS/METHODS

A total of 17 healthy 16-18-year-old licensed drivers completed two five-night sleep conditions: SR (6.5 h in bed) versus extended sleep (ES; 10 h in bed) in counterbalanced order. After each, participants completed rural and urban/suburban courses in a driving simulator, and parents rated participants' attention in day-to-day settings. Vulnerability to SR was computed as cross-condition change in parent ratings. Dependent variables included standard deviation (SD) of lateral lane position (SDLP), mean speed, SD of speed, and crashes. Multivariate models examined the main and interaction effects of sleep condition, driving environment, and vulnerability to SR, covarying for years licensed.

RESULTS

Although the effects for the other outcomes were nonsignificant, there were three-way interactions (sleep × drive × vulnerability) for mean speed and SDLP (p <0.02). During the rural drive, adolescents had less consistent lateral vehicle control in SR than ES, despite slower driving among those reported to be vulnerable to SR. During the urban/suburban drive, SR worsened SDLP only among adolescents reported to be vulnerable to SR.

CONCLUSIONS

These preliminary findings suggest that even a moderate degree of SR may be a modifiable contributor to adolescent driving problems for some. This impact is widely present during monotonous rural drives and in a subgroup during interesting urban/suburban drives.

Longitudinal Evaluation of the Cognitive-Behavioral Model of ADHD in a Sample of College Students With ADHD

OBJECTIVE

The primary aim of this study was to evaluate longitudinal pathways to impairment as outlined in the cognitive-behavioral model of ADHD in a sample of 59 college students diagnosed with ADHD.

METHOD

Serial mediation models were used to test whether underachievement, defined as prior year GPA, would longitudinally predict self-reported impairment at the end of the next school year, through negative self-concept and associated changes in symptoms of anxiety and depression, while controlling for baseline impairment and changes in ADHD symptoms.

RESULTS

Findings supported the cognitive-behavioral model of ADHD. The association between prior year GPA and overall impairment at the end of the year was fully mediated through self-concept and symptoms of depression.

CONCLUSION

These results help explain why impairment often persists even when ADHD symptoms remit and suggests that internalizing symptoms may be an important target for intervention in college students with ADHD.

The medico-legal investigation of abandoned fetuses and newborns--a review of cases admitted to the Pretoria Medico-Legal Laboratory, South Africa

There is a dearth of literature on the extent of fetal or newborn abandonment or "dumping" and the medico-legal investigation procedures these cases require. This is despite the fact that these occurrences are a worldwide phenomenon and by definition involve criminal law concerns such as illegal abortion, concealment of birth, murder, or neonaticide, depending on the country concerned. This article contributes to current literature in both respects and provides a retrospective case audit for the period 2004-2008 pertaining to all abandoned newborns and fetuses admitted to the Pretoria Medico-Legal Laboratory (PMLL) in South Africa. Demographic details, scope, and nature of the medico-legal investigation as well as formulation of cause of death were recorded. A total of 289 cases were identified for inclusion in this study, 57% of which were considered to have been non-viable fetuses, while 45 of the viable fetuses were deemed to have been stillborn. These instances involve the crimes of concealment of birth and at times illegal abortion, yet prosecution of these cases are relatively unheard of. Signs of live birth were identified in 38 of the cases in the study. Of these infants, 9 were deemed to have died from injuries they have sustained, and in a further 9 cases, no anatomical cause of death could be identified. Homicidal cases should be brought in cases where death ensued as a result of abandonment; however, it is not known how many cases were prosecuted. A comparatively large number of cases were found to have been admitted to the Pretoria Medico-Legal Laboratory. This is alarming because South African abortion laws are liberal and services are free at point of access in the public health care sector. A substantial percentage of cases of abandoned infants were found to have shown signs of life after birth implying a homicidal manner of death or death by abandonment, but it seems these cases are merely shelved.

Enhancing the Measure of Participation Burden in Protocol Design to Incorporate Logistics, Lifestyle, and Demographic Characteristics

BACKGROUND

Growing interest in improving patient participation convenience and the feasible execution of clinical trials has increased demand for new approaches to leverage patient input in the protocol design process.

METHODS

This study builds on prior work conducted by the Tufts Center for the Study of Drug Development in collaboration with ZS. A comprehensive participant burden algorithm based on protocol procedures, participation requirements and lifestyle preferences was developed and tested. Clinical trial preferences and perceptions from 3002 global patients were analyzed to inform and derive the algorithm. It was next tested against a convenience sample of 266 completed protocols. Descriptive statistics, significance tests, and regression analyses were performed.

RESULTS

Mean participant burden scores were highly associated with, and predictive (p < 0.01) of, screen failure rates, overall clinical trial duration and the number of substantial protocol amendments; and predictive (p < 0.05) of protocol treatment duration. Of 11 subgroups assessed, those that most influenced the algorithm and drove higher overall burden scores included disease condition, caregiver reliance, race, prior experience as a clinical trial participant and participant age. Geographic area and participant sex showed only minimal influence.

CONCLUSION

This study presents advancement and refinement in measuring participation burden that will assist drug development teams and protocol authors in retrospectively understanding clinical trial performance outcomes and in prospectively informing protocol design decisions.

The regulated synthesis of a Bacillus anthracis spore coat protein that affects spore surface properties

AIMS

Examine the regulation of a spore coat protein and the effects on spore properties.

METHODS AND RESULTS

A c. 23 kDa band in coat/exosporial extracts of Bacillus anthracis Sterne spores varied in amount depending upon the conditions of sporulation. It was identified by MALDI as a likely orthologue of ExsB of Bacillus cereus. Little if any was present in an exosporial preparation with a location to the inner coat/cortex region established by spore fractionation and immunogold labelling of electron micrograph sections. Because of its predominant location in the inner coat, it has been renamed Cotγ. It was relatively deficient in spores produced at 37°C and when acidic fermentation products were produced a difference attributable to transcriptional regulation. The deficiency or absence of Cotγ resulted in a less robust exosporium positioned more closely to the coat. These spores were less hydrophobic and germinated somewhat more rapidly. Hydrophobicity and appearance were rescued in the deletion strain by introduction of the cotγ gene.

CONCLUSIONS

The deficiency or lack of a protein largely found in the inner coat altered spore hydrophobicity and surface appearance.

SIGNIFICANCE AND IMPACT OF THE STUDY

The regulated synthesis of Cotγ may be a paradigm for other spore coat proteins with unknown functions that modulate spore properties in response to environmental conditions.

ARTIA-Bladder: Daily Online Adaptive Short-Course Radiation Therapy (RT) and Concurrent Chemotherapy for Muscle-Invasive Bladder Cancer (MIBC): A Prospective Trial of an Individualized Approach for Reducing Bowel and Bladder Toxicity

PURPOSE/OBJECTIVE(S)

Concurrent chemo-radiotherapy is commonly prescribed for muscle-invasive bladder cancer (MIBC). Post hoc analysis of two large, randomized trials found that hypofractionation improves loco-regional control (LRC) vs. standard fractionation in this population. A challenge in traditional image-guided radiotherapy of the bladder is that daily changes in bladder position and size requires large margins to ensure target coverage. This makes it difficult to spare uninvolved bladder from high-dose treatment, increases the risk of bowel toxicity, and results in historical rates of acute G3+ toxicity exceeding 20-30%. Daily online adaptive RT (ART) may enable reduced, personalized margins that maintain target coverage while reducing dose to OARs. This prospective clinical trial will test whether: 1) participants undergoing ART for MIBC have a lower rate of acute G3+ GI/GU toxicity compared with the 31% historical control rate (Stage III BC2001 trial), and 2) 2-year LRC with ART will be non-inferior to historical controls (75%).

MATERIALS/METHODS

This multi-national trial will enroll 165 adult subjects with stage cT2-T4aN0M0 urothelial MIBC. Subjects will have undergone an attempt at maximal transurethral resection of bladder tumor. Patients with clinically involved nodes or G2+ GI or G3+ GU symptoms/conditions at baseline are ineligible. Concurrent with chemotherapy, participants will receive (at the discretion of the investigator) either 55 Gy in 20 fx to whole-bladder or 46 Gy in 20 fx to whole-bladder plus simultaneous in-field boost of 55 Gy in 20 fx to tumor bed. A personalized ITV will be derived for each subject based on bladder expansion, as assessed on two CT simulations separated by 30 min. Daily ART will be attempted for all subjects. The primary endpoint is acute G3+ GI/GU toxicity. Secondary endpoints are LRC; quality of life (EORTC QLQ-BLM30, EPIC 26 bowel and urinary); global function (EQ-5D-5L ); 2-year disease-free, bladder intact event-free, and overall survival; 2-year bladder cancer-specific mortality; NTCP model of acute GI toxicity for hypofractionated bladder RT; workflow feasibility of ART; improved target coverage ± reduced dose to critical OARs vs. non-ART dosimetry; acute G3+ GI/GU toxicity rate in subjects with ≥75% of their treatments as ART; and acute G3+ GI/GU toxicity in the cohort treated with partial bladder boost. Exploratory translational and correlative endpoints will also be examined.

RESULTS

This trial opened to enrollment on Feb 2, 2023; the study duration is expected to be 4-5 years.

CONCLUSION

This prospective clinical trial will provide robust clinical data to inform healthcare providers' decisions on the use of daily online ART and hypofractionation as a bladder preservation strategy for this population.

Deletion of voltage-gated calcium channels in astrocytes decreases neuroinflammation and demyelination in a murine model of multiple sclerosis

The experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis was used in combination with a Cav1.2 conditional knock-out mouse (Cav1.2KO) to study the role of astrocytic voltage-gated Ca++ channels in autoimmune CNS inflammation and demyelination. Cav1.2 channels were specifically ablated in Glast-1-positive astrocytes by means of the Cre-lox system before EAE induction. After immunization, motor activity was assessed daily, and a clinical score was given based on the severity of EAE symptoms. Cav1.2 deletion in astrocytes significantly reduced the severity of the disease. While no changes were found in the day of onset and peak disease severity, EAE mean clinical score was lower in Cav1.2KO animals during the chronic phase of the disease. This corresponded to better performance on the rotarod and increased motor activity in Cav1.2KO mice. Furthermore, decreased numbers of reactive astrocytes, activated microglia, and infiltrating lymphocytes were found in the lumbar section of the spinal cord of Cav1.2KO mice 40 days after immunization. The degree of myelin protein loss and size of demyelinated lesions were also attenuated in Cav1.2KO spinal cords. Similar results were found in EAE animals treated with nimodipine, a Cav1.2 Ca++ channel inhibitor with high affinity to the CNS. Mice injected with nimodipine during the acute and chronic phases of the disease exhibited lower numbers of reactive astrocytes, activated microglial, and infiltrating immune cells, as well as fewer demyelinated lesions in the spinal cord. These changes were correlated with improved clinical scores and motor performance. In summary, these data suggest that antagonizing Cav1.2 channels in astrocytes during EAE alleviates neuroinflammation and protects the spinal cord from autoimmune demyelination.

Distribution of vesicle pools in cerebellar parallel fibre terminals after depression of ectopic transmission

At parallel fibre terminals in the cerebellar cortex, glutamate released outside of the active zone can activate AMPA receptors on juxtaposed Bergmann glial cell processes. This process is termed “ectopic” release, and allows for directed transmission to astroglial cells that is functionally independent of synaptic transmission to postsynaptic Purkinje neurons. The location of ectopic sites in presynaptic terminals is uncertain. Functional evidence suggests that stimulation of parallel fibres at 1 Hz exhausts ectopic transmission due to a failure to rapidly recycle vesicles to the ectopic pool, and so would predict a loss of vesicles in the near vicinity of extrasynaptic glial processes. In this study we used this stimulation protocol to investigate whether the distribution of vesicles within the presynaptic terminal is altered after suppression of ectopic release. Stimulation at 1 Hz had only a minor impact on the distribution of vesicles in presynaptic terminals when analysed with electron microscopy. Vesicle number and terminal size were unaffected by 1 Hz stimulation, but the relative abundance of vesicles in close proximity to the active zone was marginally reduced. In contrast, the fraction of vesicles facing glial membranes was unchanged after suppression of ectopic transmission. 1 Hz stimulation also resulted in a small but statistically-significant increase in the distance between glial membrane and presynaptic terminal, suggesting withdrawal of glial membranes from synapses is detectable in ultrastructural anatomy within minutes. These results raise doubts about the location of ectopic release sites, but indicate that neuron-glial association varies on a dynamic time scale.

Postcontraction [acetylcarnitine] reflects interindividual variation in skeletal muscle ATP production patterns in vivo

In addition to its role in substrate selection (carbohydrate vs. fat) for oxidative metabolism in muscle, acetylcarnitine production may be an important modulator of the energetic pathway by which ATP is produced. A combination of noninvasive magnetic resonance spectroscopy measures of cytosolic acetylcarnitine and ATP production pathways was used to investigate the link between [acetylcarnitine] and energy production in vivo. Intracellular metabolites were measured in the vastus lateralis muscle of eight males (mean: 28.4 yr, range: 25-35) during 8 min of incremental, dynamic contractions (0.5 Hz, 2-min stages at 6%, 9%, 12%, and 15% maximal torque) that increased [acetylcarnitine] approximately fivefold from resting levels. ATP production via oxidative phosphorylation, glycolysis, and the creatine kinase reaction was calculated based on phosphorus metabolites and pH. Spearman rank correlations indicated that postcontraction [acetylcarnitine] was positively associated with both absolute (mM) and relative (% total ATP) glycolytic ATP production (rs = 0.95, P = 0.001; rs = 0.93, P = 0.002), and negatively associated with relative (rs = -0.81, P = 0.02) but not absolute (rs = -0.14, P = 0.75) oxidative ATP production. Thus, acetylcarnitine accumulated more when there was a greater reliance on "nonoxidative" glycolysis and a relatively lower contribution from oxidative phosphorylation, reflecting the fate of pyruvate in working skeletal muscle. Furthermore, these data indicate striking interindividual variation in responses to the energy demand of submaximal contractions. Overall, the results of this preliminary study provide novel evidence of the coupling in vivo between ATP production pathways and the carnitine system.NEW & NOTEWORTHY Production of acetylcarnitine from acetyl-CoA and free carnitine may be important for energy pathway regulation in contracting skeletal muscle. Noninvasive magnetic resonance spectroscopy was used to investigate the link between acetylcarnitine and energy production in the vastus lateralis muscle during dynamic contractions (n = 8 individuals). A positive correlation between acetylcarnitine accumulation and "nonoxidative" glycolysis and an inverse relationship with oxidative phosphorylation, provides novel evidence of the coupling between ATP production and the carnitine system in vivo.

Suicide by poisoning in Pakistan: review of regional trends, toxicity and management of commonly used agents in the past three decades

BACKGROUND

Suicide is one of the leading mental health crises and takes one life every 40 seconds. Four out of every five suicides occur in low- and middle-income countries. Despite religion being a protective factor against suicide, the estimated number of suicides is rapidly increasing in Pakistan.

AIMS

Our review focuses on the trends of suicide and means of self-poisoning in the past three decades, and the management of commonly used poisons.

METHOD

We searched two electronic databases (PubMed and PakMediNet) for published English-language studies describing agents used for suicide in different regions of Pakistan. A total of 46 out of 85 papers (N = 54 747 cases) met our inclusion criteria.

RESULTS

Suicidal behaviour was more common among individuals younger than 30 years. Females comprised 60% of those who attempted suicide in our study sample, although the ratio of completed suicides favoured males. There were regional trends in the choice of agent for overdose. Organophosphate poisoning was reported across the nation, with a predominance of cases from the agricultural belt of South Punjab and interior Sindh. Aluminium phosphide ('wheat pills') was a preferred agent in North Punjab, whereas paraphenylenediamine ('kala pathar') was implicated in deaths by suicide from South Punjab. Urban areas had other means for suicide, including household chemicals, benzodiazepines, kerosene oil and rat poison.

CONCLUSIONS

Urgent steps are needed, including psychoeducational campaigns on mental health and suicide, staff training, medical resources for prompt treatment of self-poisoning and updated governmental policy to regulate pesticide sales.