bluuebunny/crossref_metadata_2025 huggingface dataset:
Diabetic retinopathy in the SEARCH for Diabetes in Youth Cohort: a pilot study
Authors: Mayer‐Davis E. J. , Davis C. , Saadine J. , D’Agostino R. B. , Dabelea D. , Dolan L. , Garg S. , Lawrence J. M. , Pihoker C. , Rodriguez B. L. , Klein B. E. , Klein R. ,   for the SEARCH for Diabetes in Youth Study Group
Published: January 2012

Diabet. Med. 29, 1148–1152 (2012)

Aims  The aim of this pilot study was to generate an initial estimate of the prevalence and correlates of diabetic retinopathy in a racially and ethnically diverse sample of youth with Type 1 and Type 2 diabetes mellitus.

Methods  A pilot study was conducted among 222 individuals with Type 1 diabetes (79% non‐Hispanic white, 21% other) and 43 with Type 2 diabetes (28% non‐Hispanic white, 72% other), all of > 5 years duration (mean duration 6.8 years) who participated in the SEARCH for Diabetes in Youth study. Diabetic retinopathy was assessed using non‐mydriatic retinal photography of both eyes.

Results  The prevalence of diabetic retinopathy was 17% for Type 1 diabetes and 42% for Type 2 diabetes (odds ratio 1.50, 95% CI 0.58–3.88; P = 0.40 adjusted for age, duration, gender, race/ethnicity, parental education and HbA1c. HbA1c was significantly higher among those with any diabetic retinopathy (adjusted mean 79 mmol/mol, 9.4%) vs. no diabetic retinopathy (adjusted mean 70 mmol/mol, 8.6%) (P = 0.015). LDL cholesterol was also significantly higher among those with any diabetic retinopathy (adjusted mean 107.2 mg/dl) compared with those without diabetic retinopathy (adjusted mean 97.9 mg/dl) (P = 0.04).

Conclusions  The prevalence of diabetic retinopathy in contemporary young individuals was substantial, particularly among minority youth and those with Type 2 diabetes. Further long‐term study of diabetic retinopathy in youth is needed.
CYBA C242T polymorphism is associated with obesity and diabetes mellitus in Brazilian hypertensive patients
Authors: Schreiber R. , Ferreira‐Sae M. C. , Tucunduva A. C. , Mill J. G. , Costa Felipe O. , Krieger J. E. , Franchini K. G. , Pereira A. C. , Nadruz W.
Published: January 2012

Diabet. Med. 29, e55–e61 (2012)

Aims  The CYBA C242T polymorphism has been associated with cardiovascular phenotypes such as hypertension and atherosclerosis, but available data are conflicting. This report investigated the impact of this variant on hypertension and metabolic determinants of cardiovascular risk in a large Brazilian sample.

Methods  We cross‐sectionally evaluated 1856 subjects (826 normotensive subjects and 1030 hypertensive patients) by clinical history, anthropometry, laboratory analysis and genotyping of the CYBA C242T polymorphism.

Results  Genotype frequencies in the whole population were consistent with the Hardy–Weinberg equilibrium and genotype distributions were not different between hypertensive and normotensive subjects. Hypertensive patients with the CC genotype presented lower fasting plasma glucose levels (5.9 ± 0.1 vs. 6.2 ± 0.1 mmol/l, P = 0.020) and waist circumference (94.5 ± 0.6 vs. 96.3 ± 0.6 cm, P = 0.028) than CT + TT ones. Similarly, the prevalence of diabetes mellitus and obesity was also lower in hypertensive patients carrying the CC genotype (16% vs. 21%, P = 0.041; 36% vs. 43%, P = 0.029, respectively). In addition, multiple and logistic regression analysis demonstrated that the CYBA C242T polymorphism was associated with glucose levels, waist circumference, obesity and diabetes mellitus in hypertensive patients independently of potential confounders. Conversely, in normotensive subjects, no significant difference in studied variables was detected between the genotype groups.

Conclusions  These data suggest that the T allele of the CYBA C242T polymorphism may be used as a marker for adverse metabolic features in Brazilian subjects with systemic hypertension.
Invasive woody plants affect the composition of native lizard and small mammal communities in riparian woodlands
Authors: Bateman H. L. , Ostoja S. M.
Published: January 2012

Nonnative Tamarix spp. (saltcedar) is among the most invasive and common trees along riparian habitats in the western U S, impacting native plant communities and habitat quality. Tamarix dominance causes a reduction in habitat physiognomic heterogeneity in riparian habitats. Animal abundance, diversity and habitat associations in monotypic stands of saltcedar remain largely unexplored for non‐avian communities. We sampled small vertebrate and ground arthropod communities in monotypic Tamarix stands and in mixed stands of Tamarix and native (Populus, Salix, and Prosopis spp.) trees in riparian habitats along the Virgin River in the Mojave Desert. Our survey of faunal communities suggests that many species of arthropods, reptiles and small mammals utilize both Tamarix‐dominated and mixed habitats along the Virgin River. Small mammal and lizard communities were dominated by generalist species. Mixed stands had greater arthropod abundance, lizard abundance and small mammal diversity; whereas, monotypic and mixed stands had similar lizard diversity. The habitat of mixed sites was characterized by ‘nativeness’ (areas with native riparian trees) and less ‘shady exotic thickets’ (areas with Tamarix and high overstory cover) compared to Tamarix‐dominated stands. There were species‐specific responses to habitat physiognomy. Peromyscus maniculatus (deer mouse) was associated with shady exotic thickets. Sceloporus magister (desert spiny lizard) and Neotoma lepida (desert woodrat) were associated with native trees and woody debris. Seven rodent and lizard species’ abundances were explained by habitat physiognomy variables. Rare and specialist species were more impacted by nonnative vegetation. These results contribute to the body of research on animal utilization of nonnative habitats and relation to habitat physiognomy. Management of nonnative plants should consider how control activities could impact habitat physiognomy and native animal communities in riparian habitat.
Seasonal and altitudinal influences on the home range and movements of common wombats in the Australian Snowy Mountains
Authors: Matthews A , Green K
Published: January 2012

Many animals throughout the world are excluded from areas because of seasonal snow cover. The aim of this study was to determine how snow influences the home range use and movements of the common wombat, a large burrowing mammal that remains active in the subalpine zone of the Australian Snowy Mountains throughout winter but is not resident in the alpine zone (above treeline). Global positioning system collars were deployed on wombats to monitor nightly movements continuously over both the winter and non‐winter periods. Home ranges of wombats (six male, five female) were far larger than previously reported (mean = 172 ha; 95% kernel method), and increased significantly with altitude. Wombats typically remained in their non‐winter home range during winter, but they contracted their range (by 7–43%) and shifted their centre of activity. Some wombats also moved more slowly and did not travel as far each night during winter. This study has shown that wombats at their upper range limit in marginal habitat exhibit a high degree of behavioural flexibility and have a surprising capacity for long‐distance movements over large home ranges, despite their need to burrow. This suggests that the alpine zone is easily within their dispersal range, but they are currently constrained by snow depth. If the snow cover continues to decline, then wombats will be limited only by the suitability of the habitat in the alpine zone, such as for burrowing.
The Impact of Scale, Recycling Boundary, and Type of Waste on Symbiosis and Recycling
Authors: Chen Xudong , Fujita Tsuyoshi , Ohnishi Satoshi , Fujii Minoru , Geng Yong
Published: January 2012

Innovative waste recycling through industrial processes such as industrial and urban symbiosis has long been practiced and recently received much attention in the field of industrial ecology, with researchers making efforts to identify key contributing factors to successful industrial symbiosis. By analyzing 88 sample recycling projects in 23 eco‐towns in Japan, this article focuses on the factors of project scale, recycling boundary, and types of waste in relationship to environmental benefits and operational performance. The results showed that larger eco‐towns achieved more savings of virgin materials and higher stability in operation. Large‐scale projects tended to locate closer to the users of recycled products than did small‐scale projects. For treating similar types of waste, projects producing recycled products for special users (e.g., feedstock to a blast furnace for iron production) tended to locate closer to the users than those not producing for special users. The type of waste had a strong effect on the savings of virgin materials and recycling boundaries, while local factors had significant impacts on operational performance. The results also showed that agglomeration did not significantly contribute to the environmental benefits or operational performance of eco‐town projects. Another finding was that national agencies were helpful for facilitating cross‐prefecture transportation and long‐distance transaction of wastes. Implications of the findings are also discussed.
Diffusion Tensor Imaging of Basal Ganglia and Thalamus in Amyotrophic Lateral Sclerosis
Authors: Sharma Khema R. , Sheriff Sulaiman , Maudsley Andrew , Govind Varan
Published: January 2012

PURPOSE

To assess the involvement of basal ganglia and thalamus in patients with amyotrophic lateral sclerosis (ALS) using diffusion tensor imaging (DTI) method.

METHODS

Fourteen definite‐ALS patients and 12 age‐matched controls underwent whole brain DTI on a 3T scanner. Mean‐diffusivity (MD) and fractional anisotropy (FA) were obtained bilaterally from the basal ganglia and thalamus in the regions‐of‐interest (ROIs).

RESULTS

The MD was significantly higher (P < .02) in basal ganglia and thalamus in patients with ALS compared with controls. Correspondingly, the FA was significantly lower (P < .02) in these structures, except in caudate (P = .04) and putamen (P = .06) in patients compared with controls. There were mild to strong correlations (r = .3−.7) between the DTI measures of basal ganglia and finger‐tap, foot‐tap, and lip‐and‐tongue movement rate.

CONCLUSIONS

The increased MD in basal ganglia and thalamus and decreased FA in globus pallidus and thalamus are indicative of neuronal loss or dysfunction in these structures.
Diffusion Tensor Imaging Analysis of Tumefactive Giant Brain Lesions in Multiple Sclerosis
Authors: Miron Shmuel , Tal Sigal , Achiron Anat
Published: January 2012

BACKGROUND AND PURPOSE

Diffusion tensor imaging (DTI) quantifies the motion of water within brain tissue. Inflammation leads to tissue disruption, resulting in increased diffusivity and decreased directionality. We aimed to quantify the damage within tumefactive giant brain lesions (TGL) in multiple sclerosis (MS) using MRI and DTI methodology.

METHODS

Region of interest were determined on TGL and acute MS lesions to obtain metrics such as volume, apparent diffusion coefficient (ADC), fractional anisotropy (FA), axial diffusivity (λ||), and radial diffusivity (λ⊥).

RESULTS

We identified 10 TGL in 10 patients with MS. The incidence of TGL was 2.8%. Comparing TGL to acute 16 MS lesions, DTI metrics demonstrated significantly higher ADC, λ|| and λ⊥ diffusivities and lower FA values in TGL (P <.001). Five TGL were reevaluated after 120 days by MRI and DTI metrics. Significant group changes were detected at 120 days: TGL volume decreased, ADC, λ|| and λ⊥ values were lower and FA was higher (P < .01).

CONCLUSIONS

Within the spectrum of acute MS lesions, TGL present DTI metrics of an intense acute inflammatory process. Analysis of TGL progression proposes that DTI metrics sensitively detects micro‐structural changes in TGL from acute inflammation towards lesion recovery and reorganization.
The response of aphids to plant water stress – the case of Myzus persicae and Brassica oleracea var. capitata
Authors: Simpson K. L. S. , Jackson G. E. , Grace J.
Published: January 2012

The possible repercussions of decreasing water availability in plant–insect interactions largely remain unclear. To study this, we designed two factorial studies applying two levels of water stress to Brassica oleraceae var. capitata L. (Brassicaceae) plants inoculated with the aphid Myzus persicae Sulzer (Hemiptera: Aphididae: Macrosiphini). One study investigated the effect of aphids and water stress on leaf water potential components, aphid population size, aphid intrinsic rate of increase (rm), and fecundity. The other investigated the effect of aphids and water stress on gas exchange, leaf fluorescence yield, estimation of leaf chlorophyll, and above‐ground dry weight. Drought treatment reduced the size of the M. persicae population. Aphid numbers were strongly and positively correlated with soil moisture and negatively correlated with leaf temperature. Aphids on droughted plants had lower rm and lower fecundity per aphid. Under aphid stress, plants showed reduced maximum photosynthetic rate (Amax), lower leaf chlorophyll as estimated by soil plant analysis development (SPAD) values, higher osmotic potential, and reduced final above‐ground dry weight compared with control plants. Aphid infestation also led to significantly higher leaf water potentials and reduced light‐adapted fluorescence yield. Compared with control plants, water‐stressed plants showed reduced Amax, lower SPAD values, reduced leaf water potential, lower turgor, and reduced final above‐ground dry weight. Osmotic potential was lower in droughted plants when aphids were not present. Plants under combined aphid and water stress showed significantly reduced SPAD and final above‐ground dry weight, with comparatively higher leaf water potentials. These results show that aphid infestation limits solute accumulation in the vacuole of drought stressed cabbage. Aphid infestation reduced the host’s ability to photosynthesise optimally and led to reduced growth. Plant stress hypotheses propose that a senescence feeder such as M. persicae would show higher rates of growth in response to the increasing ‘quality’ of the phloem sap under water shortage. In the case of M. persicae, our results do not support the hypothesis that drought leads to improved aphid population growth and survival.
Feeding disruption of potato psyllid, Bactericera cockerelli, by imidacloprid as measured by electrical penetration graphs
Authors: Butler Casey D. , Walker Gregory P. , Trumble John T.
Published: January 2012

The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a serious pest of potatoes that can cause yield loss by direct feeding and by transmitting a bacterial pathogen, Candidatus Liberibacter psyllaurous (also known as Candidatus L. solanacearum), which is associated with zebra chip disease of this crop. Current pest management practices rely on the use of insecticides for control of potato psyllid to lower disease incidences and increase yields. Imidacloprid is typically applied at potato planting, and it remains unknown if imidacloprid has any effect on potato psyllid feeding behavior. Thus, our specific objectives of this study were to determine and characterize the effects of imidacloprid treatment (0.11 ml l−1) to potato plants on adult potato psyllid feeding behavior 1, 2, and 4 weeks post‐application. Electrical penetration graph (EPG) recordings of potato psyllid feeding revealed six EPG waveforms, which include non‐probing (NP), intercellular stylet penetration (C), initial contact with phloem tissue (D), salivation into phloem sieve elements (E1), phloem sap ingestion (E2), and ingestion of xylem sap (G). The number of NP events and the duration of individual NP events significantly increased on plants treated with imidacloprid compared with untreated controls. Potato psyllids exhibited significant decreases in the number of phloem salivation events on plants treated with imidacloprid. Waveform durations and waveform durations per event for E2 and G were significantly decreased for psyllids on plants treated with imidacloprid compared with untreated controls. These data suggest that the effective use of imidacloprid to reduce transmission of Ca. Liberibacter psyllaurous is related to the negative effects of imidacloprid on psyllid feeding.
Does pelvic venous congestion syndrome exist and can it be treated?
Authors: BALL ELIZABETH , KHAN KHALID S. , MEADS CATHERINE
Published: January 2012

Chronic pelvic pain (CPP) is a common and costly health problem in gynecology. Operative pathological findings are often absent. In some women with CPP, pelvic venous congestion has been reported; however, this observation has also been made in asymptomatic women. Thus, it is not clear whether pelvic venous congestion causes CPP and, if it does, whether it is a direct or indirect cause. Venography and non‐invasive imaging methods are used for the diagnosis, but scoring systems have not been validated. The current mainstay of treatment is venography‐controlled embolization, which is less invasive than surgical interventions. However, the only evidence on effectiveness comes from uncontrolled case series. A systematic review of causation evidence is needed to prove whether pelvic venous congestion causes CPP and whether embolization treatment is effective. In addition, if causation is established, good‐quality primary randomized controlled trials on embolization may be required.
Effects of combined treatment with clorgyline and selegiline on extracellular noradrenaline and serotonin levels
Authors: Kitaichi Yuji , Inoue Takeshi , Nakagawa Shin , Boku Shuken , Koyama Tsukasa
Published: January 2012

Kitaichi Y, Inoue T, Nakagawa S, Boku S, Koyama T. Effects of combined treatment with clorgyline and selegiline on extracellular noradrenaline and serotonin levels.

Objective Combined treatment with clorgyline, an irreversible monoamine oxidase (MAO)-A inhibitor, and selegiline, an irreversible MAO-B inhibitor, reportedly increases extracellular serotonin levels in the raphe nuclei more than clorgyline does alone. However, the effects of combination of these MAO inhibitors on extracellular noradrenaline have not been reported.

Methods Using in vivo microdialysis, we measured extracellular noradrenaline and serotonin levels after administration of clorgyline and/or selegiline in the medial prefrontal cortex of rats.

Results Administration of clorgyline (10 mg/kg) significantly increased both extracellular serotonin and noradrenaline levels. Combined treatment using clorgyline (10 mg/kg) and selegiline (3 mg/kg) increased extracellular serotonin and noradrenaline levels more than each drug alone did.

Conclusions These findings of this study suggest the augmented antidepressant action of the combination of MAO-A inhibition and MAO-B inhibition. The addition of a MAO-A inhibitor to selegiline or increasing dose of selegiline to achieve full MAO-A inhibition might be the promising strategy for the antidepressant treatment in partial responders or non-responders to selegiline.
Applicability of a combination of hemoglobin A1c and fasting plasma glucose in population‐based prediabetes screening
Authors: Okosun Ike S. , Davis‐Smith Monique , Paul Seale J. , Ngulefac John
Published: January 2012

Background:  The purpose of this study is to determine: (i) the concordance between a combination of hemoglobin A1c (HbA1c) and fasting plasma glucose (FPG) (HbA1c + FPG) and a combination of FPG and 2‐h plasma glucose (2hPG) (FPG + 2hPG); and (ii) whether substituting FPG + 2hPG with HbA1c + FPG can enhance the detection of prediabetes in diabetes‐free non‐Hispanic Whites, non‐Hispanic Blacks, and Mexican–Americans adults.

Methods:  Data (n = 1376) from the 2007 to 2008 U.S. National Health and Nutrition Examination Surveys were used for this investigation. Prediabetes cut points were determined using 5.7–6.4%, 100–125, and 140–199 mg/dL for HbA1c, FPG, and 2hPG, respectively. Concordances between HbA1c and FPG, HbA1c and 2hPG, HbA1c + FPG and FPG + 2hPG in screening for undiagnosed prediabetes were determined using sensitivity, specificity, and positive and negative likelihood ratios.

Results:  The overall concordance between HbA1c + FPG and FPG + 2hPG in screening for prediabetes was high, as indicated by a sensitivity of 92.4% (95% CI = 90.5–94.5) and specificity of 84.1% (81.2–87.0). The application of HbA1c + FPG was associated with a higher prevalence of prediabetes compared to FPG + 2hPG. Compared with FPG + 2hPG, screening with HbA1c + FPG was associated with 3.2%, 24.3%, and 4.2% relative increases in the identification of prediabetes in nondiabetic non‐Hispanic Whites, non‐Hispanic Blacks and Mexican–Americans, respectively.

Conclusions:  The enhanced prevalence of prediabetes using HbA1c + FPG compared with FPG + 2hPG calls for the need to redefine at a more basic and practical level how to apply HbA1c in screening for prediabetes. A redefined HbA1c that incorporates FPG, age, race/ethnicity, and body mass index may be a better way to use HbA1c in population‐based and clinical settings.
Durability of the effect of online diabetes training for medical residents on knowledge, confidence, and inpatient glycemia
Authors: TAMLER Ronald , GREEN Dina E. , SKAMAGAS Maria , BREEN Tracy L. , LU Kevin , LOOKER Helen C. , BABYATSKY Mark , LEROITH Derek
Published: January 2012

Background:  Inpatient dysglycemia is associated with increased morbidity, mortality and cost. Medical education must not only address knowledge gaps, but also improve clinical care.

Methods:  All 129 medicine residents at a large academic medical center were offered a case‐based online curriculum on the management of inpatient dysglycemia in the fall of 2009. First‐year residents took a 3‐h course with 10 modules. Second and third‐year residents, who had been educated the prior year, underwent abbreviated training. All residents were offered a 20‐min refresher course in the spring of 2009. We assessed resident knowledge, resident confidence, and patient glycemia on two teaching wards before and after the initial intervention, as well as after the refresher course.

Results:  A total of 117 residents (91%) completed the initial training; 299 analyzed admissions generated 11 089 blood glucose values and 4799 event blood glucose values. Admissions with target glycemia increased from 19.4% to 33.0% (P = 0.035) by the end of the curriculum. There was a strong downward trend in hyperglycemia from 22.4% to 11.3% (P = 0.055) without increased hypoglycemia. Confidence and knowledge increased significantly among first‐time and repeat participants. Residents rated the intervention as highly relevant to their practice and technologically well implemented.

Conclusion:  Optimization of an online curriculum covering the management of inpatient glycemia over the course of 2 years led to significantly more admissions in the target glycemia range. Given its scalability, modularity and applicability, this web‐based educational intervention may become the standard curriculum for the management of inpatient glycemia.
Glutamatergic signaling in cellular transformation
Authors: Teh Jessica L. F. , Chen Suzie
Published: January 2012

The role of the glutamatergic system in cancer cell homeostasis has expanded exponentially over the last decade. Once thought to participate only in synaptic transmission and neuronal excitability, the presence of functional glutamate receptors has since been demonstrated in peripheral tissues. Most notable is the implication of glutamate receptors in the pathophysiology of various human malignancies. We previously described the oncogenic properties of metabotropic glutamate receptor 1 (Grm1), a G‐protein‐coupled receptor in melanoma development in vivo. TG‐3, a transgenic mouse line, developed spontaneous melanoma with 100% penetrance in the absence of any known stimuli. Stable Grm1‐mouse melanocytic clones display transformed phenotypes in vitro and were aggressively tumorigenic in vivo. Recent reports from other groups implicate two additional members of the metabotropic glutamate receptor family in melanomagenesis, overexpression of mGluR5 and activating mutations in GRM3. These findings highlight a previously underappreciated link between the glutamate signaling pathway and oncogenesis in melanoma biology, raising exciting possibilities in elucidating mechanisms in melanocyte transformation and exploring glutamate receptors as novel therapeutic targets. Here we further consider the potential mechanisms by which glutamate receptors can function as an oncogene leading to malignant transformation.
Clinicopathological Variables Predicting Progression of Azotemia in Cats with Chronic Kidney Disease
Authors: Chakrabarti S. , Syme H.M. , Elliott J.
Published: January 2012

Background

Chronic kidney disease (CKD) is common in geriatric cats, but often appears to be stable for long periods of time.

Objectives

To describeCKDprogression and identify risk factors for progression in newly diagnosed azotemic cats.

Animals

A total of 213 cats withCKD(plasma creatinine concentration > 2 mg/dL, urine specific gravity < 1.035) were followed up until progression occurred or for at least 1 year; 132, 73, and 8 cats were in International Renal Interest Society (IRIS) stages 2, 3, and 4, respectively.

Methods

Progression was defined as a 25% increase in plasma creatinine concentration. Logistic regression was used to assess variables at diagnosis that were associated with progression within 1 year. Changes inIRISstage during follow‐up also were described. Cases that remained in stages 2 or 3, but did not have renal function assessed in the last 60 days of life, were excluded from analysis of the proportion reaching stage 4.

Results

Of the cats, 47% (101) progressed within 1 year of diagnosis. High plasma phosphate concentration and high urine protein‐to‐creatinine ratio (UPC) predicted progression in all cats. LowPCVand highUPCindependently predicted progression in stage 2 cats, whereas higher plasma phosphate concentration predicted progression in stage 3 cats; 19% (18/94) of cats diagnosed in stage 2; and 63% (34/54) of cats diagnosed in stage 3 reached stage 4 before they died.

Conclusions

Proteinuria, anemia, and hyperphosphatemia may reflect more progressive kidney disease. Alternatively, they may be markers for mechanisms of progression such as tubular protein overload, hypoxia, and nephrocalcinosis.
Isorhythmic Atrioventricular Dissociation in Labrador Retrievers
Authors: Perego M. , Ramera L. , Santilli R.A.
Published: January 2012

Background

Isorhythmic atrioventricular dissociation (IAVD) is a rhythm disturbance in which atria and ventricles are driven by independent pacemakers at equal or nearly equal rates.

Objectives

To describe electrocardiographic and electrophysiologic features of IAVD in a group of 11 Labrador Retrievers and its possible correlation with focal junctional tachycardia (FJT).

Animals

Between December 2004 and October 2010, medical records of 11 Labrador Retrievers with surface electrocardiographic findings compatible with IAVD were retrospectively analyzed.

Methods

Twelve‐lead surface electrocardiograms, thoracic radiographs, and echocardiographic findings of each dog and electrophysiologic mapping results of 3 dogs were retrospectively analyzed.

Results

In 10 of 11 dogs, the ECG pattern revealed the presence of IAVD with type I synchronization. In 5 of 10 dogs, IAVD with type I synchronization was interrupted by periods of junctional tachycardia with 1 : 1 ventriculo‐atrial conduction. One of 11 dogs presented IAVD with type II synchronization. The ECG diagnosis of IAVD with type I and type II synchronization, and junctional rhythm with 1 : 1 ventriculo‐atrial conduction was confirmed in 3 of 11 dogs with endocardial mapping in which the diagnosis of focal junctional tachycardia was made.

Conclusion and Clinical Importance

IAVD with type I synchronization is more common than IAVD with type II synchronization in Labrador Retrievers, and a correlation between IAVD and FJT can be hypothesized.
Exploring liars’ strategies for creating deceptive reports
Authors: Leins Drew A. , Fisher Ronald P. , Ross Stephen J.
Published: January 2012

Purpose. Most past research on detecting deception has relied on the assumption that liars often fabricate a story to account for their whereabouts, whereas truth tellers simply recall an autobiographical memory. However, little research has examined whether liars, when free to choose the topic of their own reports, will actually choose to fabricate information rather than use a different strategy for constructing their lies. We describe two studies that evaluated liars’ strategies for selecting the content of their lies when given the freedom to choose whatever content they desired.

Method. In Studies 1 (N= 35) and 2 (N= 22) participants (a) described a truthful story in order to identify a salient event, then (b) lied about the event, and finally (c) described their strategies for choosing the content of the reported lies.

Results. Liars overwhelmingly chose to report a previously experienced event for the time period they were to be deceptive about (67% and 86% in Studies 1 and 2, respectively). The majority of discrete details reported were experienced, occurred relatively frequently, occurred relatively recently, and were typical or routine.

Conclusions. These findings have significant implications for the development of cognitive‐based interventions for detecting deception. In particular, some methods of deception that rely on content analysis may be ineffective if liars choose to report previous experiences rather than outright fabrications.
Recruitment of resting vesicles into recycling pools supports NMDA receptor‐dependent synaptic potentiation in cultured hippocampal neurons
Authors: Ratnayaka Arjuna , Marra Vincenzo , Bush Daniel , Burden Jemima J , Branco Tiago , Staras Kevin
Published: January 2012

Key points 

Presynaptic terminals in hippocampal neurons are characterized by two functionally defined vesicle populations: a recycling pool, which supports activity‐evoked neurotransmission, and a resting pool.

Between individual synapses, the relative proportions of these two pools are highly variable, suggesting that this parameter might be specifically regulated to support changes in synaptic efficacy.

Using fluorescence imaging and correlative ultrastructural approaches we show here that a form of synaptic potentiation dependent on N‐methyl‐d‐aspartic acid (NMDA) receptor activity can lead to a rapid and sustained expansion of the recycling fraction at the expense of the resting pool.

This recruitment of vesicles depends on nitric oxide signalling and calcineurin activity, and is accompanied by an increase in synaptic release probability.

We suggest that vesicle exchange between these pools provides a rapid mechanism to support adjustments in synaptic strength associated with a form of Hebbian plasticity.
Viscoelastic Material Properties of the Myocardium and Cardiac Jelly in the Looping Chick Heart
Authors: Yao Jiang , Varner Victor D. , Brilli Lauren L. , Young Jonathan M. , Taber Larry A. , Perucchio Renato
Published: January 2012

Accurate material properties of developing embryonic tissues are a crucial factor in studies of the mechanics of morphogenesis. In the present work, we characterize the viscoelastic material properties of the looping heart tube in the chick embryo through nonlinear finite element modeling and microindentation experiments. Both hysteresis and ramp-hold experiments were performed on the intact heart and isolated cardiac jelly (extracellular matrix). An inverse computational method was used to determine the constitutive relations for the myocardium and cardiac jelly. With both layers assumed to be quasilinear viscoelastic, material coefficients for an Ogden type strain-energy density function combined with Prony series of two terms or less were determined by fitting numerical results from a simplified model of a heart segment to experimental data. The experimental and modeling techniques can be applied generally for determining viscoelastic material properties of embryonic tissues.
The Regional Contribution of Glycosaminoglycans to Temporomandibular Joint Disc Compressive Properties
Authors: Willard Vincent P. , Kalpakci Kerem N. , Reimer Andrew J. , Athanasiou Kyriacos A.
Published: January 2012

Understanding structure-function relationships in the temporomandibular joint (TMJ) disc is a critical first step toward creating functional tissue replacements for the large population of patients suffering from TMJ disc disorders. While many of these relationships have been identified for the collagenous fraction of the disc, this same understanding is lacking for the next most abundant extracellular matrix component, sulfated glycosaminoglycans (GAGs). Though GAGs are known to play a major role in maintaining compressive integrity in GAG-rich tissues such as articular cartilage, their role in fibrocartilaginous tissues in which GAGs are much less abundant is not clearly defined. Therefore, this study investigates the contribution of GAGs to the regional viscoelastic compressive properties of the temporomandibular joint (TMJ) disc. Chondroitinase ABC (C-ABC) was used to deplete GAGs in five different disc regions, and the time course for >95% GAG removal was defined. The compressive properties of GAG depleted regional specimens were then compared to non-treated controls using an unconfined compression stress-relaxation test. Additionally, treated and non-treated specimens were assayed biochemically and histologically to confirm GAG removal. Compared to untreated controls, the only regions affected by GAG removal in terms of biomechanical properties were in the intermediate zone, the most GAG-rich portion of the disc. Without GAGs, all intermediate zone regions showed decreased tissue viscosity, and the intermediate zone lateral region also showed a 12.5% decrease in modulus of relaxation. However, in the anterior and posterior band regions, no change in compressive properties was observed following GAG depletion, though these regions showed the highest compressive properties overall. Although GAGs are not the major extracellular matrix molecule of the TMJ disc, they are responsible for some of the viscoelastic compressive properties of the tissue. Furthermore, the mechanical role of sulfated GAGs in the disc varies regionally in the tissue, and GAG abundance does not always correlate with higher compressive properties. Overall, this study found that sulfated GAGs are important to TMJ disc mechanics in the intermediate zone, an important finding for establishing design characteristics for future tissue engineering efforts.
Coordinating Synapses
Authors: Stern Peter R.
Published: January 2012

The computational power of individual neurons is determined by a surprisingly precise wiring of neuronal networks.
In Vitro
Potency and
In Vivo
Efficacy of a Novel Bis-Indole Antimicrobial Compound in Reducing Catheter Colonization
Authors: Mansouri Mohammad D. , Opperman Timothy J. , Williams John D. , Stager Charles , Darouiche Rabih O.
Published: January 2012

Vascular catheters coated with a novel antimicrobial agent (MBX1631) were studied for their ability to protect against bacterial colonization
in vitro
and in a rabbit model. MBX1631-coated catheters were significantly less likely to become colonized than control catheters both
in vitro
and
in vivo
(
P
< 0.001). Furthermore, device-associated infection was significantly lower in MBX1631-coated catheters than in uncoated ones (
P
< 0.005).
Diverse Mobilized Class 1 Integrons Are Common in the Chromosomes of Pathogenic Pseudomonas aeruginosa Clinical Isolates
Authors: Martinez Elena , Marquez Carolina , Ingold Ana , Merlino John , Djordjevic Steven P. , Stokes H. W. , Roy Chowdhury Piklu
Published: January 2012

Eleven clinical class 1 integron-containing
Pseudomonas aeruginosa
isolates from Australia and Uruguay were investigated for the genomic locations of these elements. Several novel class 1 integrons/transposons were found in at least four distinct locations in the chromosome, including genomic islands. These elements seem to be undergoing successful dispersal by lateral gene transfer since integrons were identified across several lineages and more than one clonal line.
Identification and characterization of Drosophila relatives of the yeast transcriptional activator SNF2/SWI2.
Authors: Elfring L K , Deuring R , McCallum C M , Peterson C L , Tamkun J W
Published: January 2012

The Drosophila brahma (brm) gene encodes an activator of homeotic genes that is highly related to the yeast transcriptional activator SWI2 (SNF2), a potential helicase. To determine whether brm is a functional homolog of SWI2 or merely a member of a family of SWI2-related genes, we searched for additional Drosophila genes related to SWI2 and examined their function in yeast cells. In addition to brm, we identified one other Drosophila relative of SWI2: the closely related ISWI gene. The 1,027-residue ISWI protein contains the DNA-dependent ATPase domain characteristic of the SWI2 protein family but lacks the three other domains common to brm and SWI2. In contrast, the ISWI protein is highly related (70% identical) to the human hSNF2L protein over its entire length, suggesting that they may be functional homologs. The DNA-dependent ATPase domains of brm and SWI2, but not ISWI, are functionally interchangeable; a chimeric SWI2-brm protein partially rescued the slow growth of swi2- cells and supported transcriptional activation mediated by the glucocorticoid receptor in vivo in yeast cells. These findings indicate that brm is the closest Drosophila relative of SWI2 and suggest that brm and SWI2 play similar roles in transcriptional activation.
The 58,000-dalton cellular inhibitor of the interferon-induced double-stranded RNA-activated protein kinase (PKR) is a member of the tetratricopeptide repeat family of proteins.
Authors: Lee T G , Tang N , Thompson S , Miller J , Katze M G
Published: January 2012

PKR is a serine/threonine protein kinase induced by interferon treatment and activated by double-stranded RNAs. As a result of activation, PKR becomes autophosphorylated and catalyzes phosphorylation of the alpha subunit of protein synthesis eukaryotic initiation factor 2 (eIF-2). While studying the regulation of PKR in virus-infected cells, we found that a cellular 58-kDa protein (P58) was recruited by influenza virus to downregulate PKR and thus avoid the kinase's deleterious effects on viral protein synthesis and replication. We now report on the cloning, sequencing, expression, and structural analysis of the P58 PKR inhibitor, a 504-amino-acid hydrophilic protein. P58, expressed as a histidine fusion protein in Escherichia coli, blocked both the autophosphorylation of PKR and phosphorylation of the alpha subunit of eIF-2. Western blot (immunoblot) analysis showed that P58 is present not only in bovine cells but also in human, monkey, and mouse cells, suggesting the protein is highly conserved. Computer analysis revealed that P58 contains regions of homology to the DnaJ family of proteins and a much lesser degree of similarity to the PKR natural substrate, eIF-2 alpha. Finally, P58 contains nine tandemly arranged 34-amino-acid repeats, demonstrating that the PKR inhibitor is a member of the tetratricopeptide repeat family of proteins, the only member identified thus far with a known biochemical function.
Acetylcholine muscarinic m1 receptor regulation of cyclic AMP synthesis controls growth factor stimulation of Raf activity.
Authors: Russell M , Winitz S , Johnson G L
Published: January 2012

Acetylcholine muscarinic m2 receptors (m2R) couple to heterotrimeric Gi proteins and activate the Ras/Raf/mitogen-activated protein kinase pathway and phosphatidylinositol 3-kinase in Rat 1a cells. In contrast to the m2R, stimulation of the acetylcholine muscarinic m1 receptor (m1R) does not activate the Ras/Raf/mitogen-activated protein kinase regulatory pathway in Rat 1a cells but rather causes a pronounced inhibition of epidermal growth factor and platelet-derived growth factor receptor activation of Raf. In Rat 1a cells, m1R stimulation of phospholipase C beta and the marked rise in intracellular calcium stimulated cyclic AMP (cAMP) synthesis, resulting in the activation of protein kinase A. Stimulation of protein kinase A inhibited Raf activation in response to growth factors. Platelet-derived growth factor receptor stimulation of phosphatidylinositol 3-kinase activity was not affected by either m1R stimulation or protein kinase A activation in response to forskolin-stimulated cAMP synthesis. GTP loading of Ras in response to growth factors was unaffected by protein kinase A activation but was partially inhibited by carbachol stimulation of the m1R. Therefore, protein kinase A action at the Ras/Raf activation interface selectively inhibited only one branch of the signal transduction network initiated by tyrosine kinases. Specific adenylyl cyclases responding to different signals, including calcium, with enhanced cAMP synthesis will regulate Raf activation in response to Ras.GTP. Taken together, the data indicate that G protein-coupled receptors can positively and negatively regulate the responsiveness of tyrosine kinase-stimulated mitogenic response pathways.
The novel primary response gene MyD118 and the proto-oncogenes myb, myc, and bcl-2 modulate transforming growth factor beta 1-induced apoptosis of myeloid leukemia cells.
Authors: Selvakumaran M , Lin H K , Sjin R T , Reed J C , Liebermann D A , Hoffman B
Published: January 2012

Cell numbers are regulated by a balance among proliferation, growth arrest, and programmed cell death. A profound example of cell homeostasis, controlled throughout life, is the complex process of blood cell development, yet little is understood about the intracellular mechanisms that regulate blood cell growth arrest and programmed cell death. In this work, using transforming growth factor beta 1 (TGF beta 1)-treated M1 myeloid leukemia cells and genetically engineered M1 cell variants, the regulation of growth arrest and apoptosis was dissected. Blocking of early expression of MyD118, a novel differentiation primary response gene also shown to be a primary response gene induced by TGF beta 1, delayed TGF beta 1-induced apoptosis, demonstrating that MyD118 is a positive modulator of TGF beta 1-mediated cell death. Elevated expression of bcl-2 blocked the TGF beta 1-induced apoptotic pathway but not growth arrest induced by TGF beta 1. Deregulated expression of either c-myc or c-myb inhibited growth arrest and accelerated apoptosis, demonstrating for the first time that c-myb plays a role in regulating apoptosis. In all cases, the apoptotic response was correlated with the level of MyD118 expression. Taken together, these findings demonstrate that the primary response gene MyD118 and the c-myc, c-myb, and bcl-2 proto-oncogenes interact to modulate growth arrest and apoptosis of myeloid cells.
NHP6A and NHP6B, which encode HMG1-like proteins, are candidates for downstream components of the yeast SLT2 mitogen-activated protein kinase pathway.
Authors: Costigan C , Kolodrubetz D , Snyder M
Published: January 2012

The yeast SLK1 (BCK1) gene encodes a mitogen-activated protein kinase (MAPK) activator protein which functions upstream in a protein kinase cascade that converges on the MAPK Slt2p (Mpk1p). Dominant alleles of SLK1 have been shown to bypass the conditional lethality of a protein kinase C mutation, pkc1-delta, suggesting that Pkc1p may regulate Slk1p function. Slk1p has an important role in morphogenesis and growth control, and deletions of the SLK1 gene are lethal in a spa2-delta mutant background. To search for genes that interact with the SLK1-SLT2 pathway, a synthetic lethal suppression screen was carried out. Genes which in multiple copies suppress the synthetic lethality of slk1-1 spa2-delta were identified, and one, the NHP6A gene, has been extensively characterized. The NHP6A gene and the closely related NHP6B gene were shown previously to encode HMG1-like chromatin-associated proteins. We demonstrate here that these genes are functionally redundant and that multiple copies of either NHP6A or NHP6B suppress slk1-delta and slt2-delta. Strains from which both NHP6 genes were deleted (nhp6-delta mutants) share many phenotypes with pkc1-delta, slk1-delta, and slt2-delta mutants. nhp6-delta cells display a temperature-sensitive growth defect that is rescued by the addition of 1 M sorbitol to the medium, and they are sensitive to starvation. nhp6-delta strains also exhibit a variety of morphological and cytoskeletal defects. At the restrictive temperature for growth, nhp6-delta mutant cells contain elongated buds and enlarged necks. Many cells have patches of chitin staining on their cell surfaces, and chitin deposition is enhanced at the necks of budded cells. nhp6-delta cells display a defect in actin polarity and often accumulate large actin chunks. Genetic and phenotypic analysis indicates that NHP6A and NHP6B function downstream of SLT2. Our results indicate that the Slt2p MAPK pathway in Saccharomyces cerevisiae may mediate its function in cell growth and morphogenesis, at least in part, through high-mobility group proteins.
Oncogenic activation of the Lck protein accompanies translocation of the LCK gene in the human HSB2 T-cell leukemia.
Authors: Wright D D , Sefton B M , Kamps M P
Published: January 2012

The tyrosine protein kinase p56lck transduces signals important for antigen-induced T-cell activation. In transgenic mice, p56lck is oncogenic when overexpressed or expressed as a mutant, catalytically activated enzyme. In humans, the LCK gene is located at the breakpoint of the t(1;7)(p34;q34) chromosomal translocation. This translocation positions the beta T-cell receptor constant region enhancer upstream of the LCK gene without interrupting the LCK coding sequences, and a translocation of this sort occurs in both the HSB2 and the SUP-T-12 T-cell lines. We have found that, although the level of the p56lck protein in HSB2 cells is elevated approximately 2-fold in comparison with that in normal T-cell lines, total cellular tyrosine protein phosphorylation is elevated approximately 10-fold. Increased levels of phosphotyrosine in HSB2 cells resulted from mutations in the LCK gene that activated its function as a phosphotransferase and converted it into a dominant transforming oncogene. The oncogenic p56lck in HSB2 cells contained one amino acid substitution within the CD4/CD8-binding domain, two substitutions in the kinase domain, and an insertion of Gln-Lys-Pro (QKP) between the SH2 and kinase domains. In NIH 3T3 fibroblasts, three of these mutations cooperated to produce the fully oncogenic form of this p56lck variant. These results suggest that mutation of LCK may contribute to some human T-cell leukemias.