The potential role of melatonin on sleep deprivation-induced cognitive impairments: implication of FMRP on cognitive function

While prolonged sleep deprivation (SD) could lead to profound negative health consequences, such as impairments in vital biological functions of immunity and cognition, melatonin possesses powerful ameliorating effects against those harmful insults. Melatonin has strong antioxidant and anti-inflammatory effects that help to restore body's immune and cognitive functions. In this study, we investigated the possible role of melatonin in reversing cognitive dysfunction induced by SD in rats. Our experimental results revealed that sleep-deprived animals exhibited spatial memory impairment in the Morris water maze tasks compared with the control groups. Furthermore, there was an increased glial activation most prominent in the hippocampal region of the SD group compared to the normal control (NC) group. Additionally, markers of oxidative stress such as 4-hydroxynonenal (4-HNE) and 7,8-dihydro-8-oxo-deoxyguanine (8-oxo-dG) were significantly increased, while fragile X-mental retardation protein (FMRP) expression was decreased in the SD group. Interestingly, melatonin treatment normalized these events to control levels following SD. Our data demonstrate that SD induces oxidative stress through glial activation and decreases FMRP expression in the neurons. Furthermore, our results suggest the efficacy of melatonin for the treatment of sleep-related neuronal dysfunction, which occurs in neurological disorders such as Alzheimer's disease and autism.

Enhancement of the Color Rendering Index of White Organic Light-Emitting Devices Based on a Blue and Red Emitting Layer with a Y3Al5O12:Ce3+ Green Phosphor Color-Conversion Layer

White organic light-emitting devices (WOLEDs) were fabricated utilizing blue and red emitting organic light-emitting devices and a color conversion layer (CCL) made of yttrium aluminum garnet (YAG:Ce3+) phosphors embedded into polymethylmethacrylate. The good color balance for the color conversion of the WOLEDs was achieved utilizing 20-nm blue and 10-nm red OLEDs. The electroluminescence spectrum for the fabricated device showed a white color consisting of the blue color from the 4,4-bis(2,2-diphenylethen-1-yl)bipheny layer, the red color from the tris-(8-hydroxyquinolinato) aluminum: 4-(dicyanomethylene)-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran layer, and the green color from the YAG:Ce3+ phosphor. The Commission Internationale de l'Eclairage coordinates of the WOLEDs slightly shifted from (0.25, 0.23) of the blue and red emission OLEDs without phosphors to (0.34, 0.35) of the OLEDs with green phosphors, indicative of the pure white color. WOLEDs with a CCL exhibited three wavelength white emissions with a color rendering index of 86.

Acute postoperative pain relief with immediate-release tapentadol: randomized, double-blind, placebo-controlled study conducted in South Korea

OBJECTIVE

To broaden the ethnic groups in which tapentadol IR is evaluated for treating acute postoperative pain to include Asians.

METHODS

In this phase 3, multicenter, double-blind, randomized study, 352 Korean adults with moderate-to-severe pain following hallux valgus surgery received tapentadol IR 50 or 75 mg or placebo orally every 4-6 hours for 72 hours. Patients requesting other (rescue) analgesics during this period were discontinued for lack of efficacy. The primary endpoint, sum of pain intensity difference (SPID) over 48 hours, was evaluated based on the difference between tapentadol IR and placebo in least squares (LS) mean change from baseline using analysis of covariance (ANCOVA). Secondary endpoints included the time to first rescue medication use and the distribution of responder rates.

RESULTS

A treatment effect, favoring tapentadol IR, was observed for SPID48 (p < 0.001 for both doses vs. placebo, ANCOVA). The between-group difference (vs. placebo) in LS means of SPID48 was 76.4 (95% CI: 51.0, 101.7) for tapentadol IR 50 mg and 90.6 (95% CI: 65.1, 116.1) for tapentadol IR 75 mg. Time to first rescue medication use was delayed for tapentadol IR (p < 0.001 for both doses vs. placebo; log-rank test). The distribution of responders at 12, 24, 48, and 72 hours favored tapentadol IR (p ≤ 0.001 for both doses vs. placebo; Cochran-Mantel-Haenszel test). Dizziness, nausea, and vomiting were each reported in ≥ 10% tapentadol-treated patients and at an incidence ≥ 2-fold higher vs. placebo. The study findings may be limited by study drug dosing every 4 to 6 hours and frequent monitoring during treatment, neither of which mimic pain treatment in clinical practice. However, any potential bias based on this systematic monitoring of patients would be mitigated by the randomized, double-blind nature of the study, with all treatment groups similarly affected by such biases, if any.

CONCLUSIONS

Tapentadol IR reduced acute pain intensity, significantly more than placebo, after orthopedic surgery in Korean patients.

CLINICAL TRIAL REGISTRATION

NCT01516008.

Evaluation of dronedarone as a therapeutic option for patients with atrial fibrillation

WHAT IS KNOWN AND OBJECTIVE

Atrial fibrillation (AF) is the predominant dysrhythmia affecting approximately 2·4 million people in the United States and over 6 million Europeans. Dronedarone is a benzofuran derivative of amiodarone newly approved in 2009 for the treatment of AF. Here, we comment on the efficacy and safety of dronedarone in patients with AF.

COMMENT

Eight randomized controlled trials were analysed in this article. Several trials showed that dronedarone therapy delayed AF recurrence, controlled ventricular rate and reduced incidences of hospitalization or death. However, some of the studies were terminated early due to an excess mortality rate. Further studies on long-term safety and trials on direct comparison to rate controlling medications are suggested to obtain additional insight of dronedarone.

WHAT IS NEW AND CONCLUSION

Dronedarone reduces the incidence of AF recurrences, hospitalization and death in patients with paroxysmal or persistent AF. However, dronedarone should not be used in high-risk patients with permanent AF or patients with unstable chronic heart failure (HF) due to safety concerns.

Temporal changes in foveal contour after macular hole surgery

BACKGROUND

To investigate the changes in inner foveal contour after surgery for macular hole (MH) and its clinical implications.

METHODS

This retrospective observational case series included 66 eyes from 66 patients who underwent surgery for MH. Notching of tissue was defined as an abrupt alteration in the inner contour of the parafoveal tissue based on postoperative optical coherence tomography (OCT) image. The distance between the parafoveal edges of the outer plexiform layer (OPL) was defined as the inter-OPL distance. The inter-OPL distance was divided into nasal, temporal, superior, and inferior lengths. The difference in the lengths of each direction between the early and late postoperative period was compared between directions with and without notching.

RESULTS

The early and late postoperative examination was performed at 4.6±2.9 weeks and 6.2±0.6 months, respectively. Notching of tissue was noted in 54 eyes (81.8%). In 53 eyes with a measurable inter-OPL distance, the notching of tissue was noted in 45 eyes (84.9%) regardless of preoperative MH size. The mean amount of foveal tissue elongation that occurred during the designated period was 104.6±68.8 and 78.4±72.9 μm in the directions with and without the notching of tissue (P<0.001), respectively.

CONCLUSIONS

The changes in the inner foveal contour, including notching of tissue and elongation of foveal tissue, were noted in the majority of eyes after MH surgery. Notching of tissue on OCT image could be a clinical marker for the development of foveal tissue elongation after MH surgery.

An altered intestinal mucosal microbiome in HIV-1 infection is associated with mucosal and systemic immune activation and endotoxemia

Human immunodeficiency virus-1 (HIV-1) infection disrupts the intestinal immune system, leading to microbial translocation and systemic immune activation. We investigated the impact of HIV-1 infection on the intestinal microbiome and its association with mucosal T-cell and dendritic cell (DC) frequency and activation, as well as with levels of systemic T-cell activation, inflammation, and microbial translocation. Bacterial 16S ribosomal DNA sequencing was performed on colon biopsies and fecal samples from subjects with chronic, untreated HIV-1 infection and uninfected control subjects. Colon biopsies of HIV-1-infected subjects had increased abundances of Proteobacteria and decreased abundances of Firmicutes compared with uninfected donors. Furthermore at the genus level, a significant increase in Prevotella and decrease in Bacteroides was observed in HIV-1-infected subjects, indicating a disruption in the Bacteroidetes bacterial community structure. This HIV-1-associated increase in Prevotella abundance was associated with increased numbers of activated colonic T cells and myeloid DCs. Principal coordinates analysis demonstrated an HIV-1-related change in the microbiome that was associated with increased mucosal cellular immune activation, microbial translocation, and blood T-cell activation. These observations suggest that an important relationship exists between altered mucosal bacterial communities and intestinal inflammation during chronic HIV-1 infection.

Sugar Responsible and Tissue Specific Expression of a Gene Encoding AtCIPK14, anArabidopsisCBL-Interacting Protein Kinase

Expression of AtCIPK14 (an Arabidopsis CBL-interacting protein kinase 14) was induced by metabolic sugars. Two A/T-rich sequences similar to elements involved in sugar-inducible expression of other genes were found within the -183 bp 5' region of the AtCIPK14 promoter that was responsible for the sugar induction. Histochemical analysis using a reporter gene indicated vascular-specific expression of AtCIPK14.

Experimentally increasing titin compliance in a novel mouse model attenuates the Frank-Starling mechanism but has a beneficial effect on diastole

BACKGROUND

Experimentally upregulating compliant titins has been suggested as a therapeutic for lowering pathological diastolic stiffness levels. However, how increasing titin compliance impacts global cardiac function requires in-depth study. We investigate the effect of upregulating compliant titins in a novel mouse model with a genetically altered titin splicing factor; integrative approaches were used from intact cardiomyocyte mechanics to pressure-volume analysis and Doppler echocardiography.

METHODS AND RESULTS

Compliant titins were upregulated through deletion of the RNA Recognition Motif of the splicing factor RBM20 (Rbm20(ΔRRM)mice). A genome-wide exon expression analysis and a candidate approach revealed that the phenotype is likely to be dominated by greatly increased lengths of titin's spring elements. At both cardiomyocyte and left ventricular chamber levels, diastolic stiffness was reduced in heterozygous (+/-) Rbm20(ΔRRM)mice with a further reduction in homozygous (-/-) mice at only the intact myocyte level. Fibrosis was present in only -/- Rbm20(ΔRRM) hearts. The Frank-Starling Mechanism was reduced in a graded fashion in Rbm20(ΔRRM) mice, at both the cardiomyocyte and left ventricular chamber levels. Exercise tests revealed an increase in exercise capacity in +/- mice.

CONCLUSIONS

Titin is not only important in diastolic but also in systolic cardiac function. Upregulating compliant titins reduces diastolic chamber stiffness owing to the increased compliance of myocytes, but it depresses end-systolic elastance; under conditions of exercise, the beneficial effects on diastolic function dominate. Therapeutic manipulation of the RBM20-based splicing system might be able to minimize effects on fibrosis and systolic function while improving the diastolic function in patients with heart failure.

Anti-adhesive effect of a thermosensitive poloxamer applied after the removal of nasal packing in endoscopic sinus surgery: a randomised multicentre clinical trial

OBJECTIVE

To compare the efficacies of a thermosensitive poloxamer (TPX) and Merogel in preventing adhesion applied after the removal of nasal packing in endoscopic sinus surgery as a non-inferiority trial.

DESIGN

Randomised, multicentre, single-blind, active-controlled, matched-pair study.

SETTING

Yonsei University Gangnam Severance Hospital, Korea University Guro Hospital.

PARTICIPANTS

A total of 70 patients were enroled and underwent endoscopic sinus surgeries. Four of the patients did not complete their follow-up. Analysis of the 66 enroled patients having completed postoperative assessment was performed. The severity of rhinosinusitis was graded with a Lund-McKay CT score, and only those with bilateral disease and a CT score difference ≤2 between sinuses were included.

MAIN OUTCOME MEASURES

An independent rhinologist from a third institution through a blinded assessment with digital photoendoscopy of the middle meati bilaterally taken postoperatively.

RESULTS

In the blinded assessment, thermosensitive poloxamer (anti-adhesion rate: 92%) was similar to Merogel (anti-adhesion rate: 89%). Evaluation of the presence and grade of adhesion, oedema, and infection in the middle meatus revealed no significant differences between the thermosensitive poloxamer group and the Merogel group at all postoperative periods.

CONCLUSION

Anti-adhesive effects of thermosensitive poloxamer are similar to those of Merogel. Therefore, thermosensitive poloxamer can be considered a safe alternative to Merogel for preventing adhesion in patients undergoing endoscopic sinus surgeries, and further evaluation of thermosensitive poloxamer as an anti-adhesive and primary packing material compared with the control using no packing is needed.

Factors influencing korean international students' preferences for mental health professionals: a conjoint analysis

Asian students comprise over half of all international students in the United States, yet little is known about their help-seeking behaviors and preferences for mental health professionals. The purpose of this study was to use conjoint analysis to examine characteristics of mental health professionals influencing Korean international students' preferences when choosing a mental health professional. Korean international students from three universities in the United States were recruited on a volunteer basis to participate in this study (N = 114). Results indicated that mental health professional characteristics, including ethnicity, age, professional identity, and training institution, were significant factors in students' preference formation; however, gender of the mental health professional was not found to be a significant factor in the present study. Ethnic similarity was the most powerful predictor of preference formation. Implications for promoting help-seeking and mental health service utilization among Asian international students are discussed.

Vocational rehabilitation services and employment outcomes for adults with cerebral palsy in the United States

AIM

The aim of this study was to examine the relationship between vocational rehabilitation services provided and work outcomes among people with cerebral palsy (CP), taking in to account demographic characteristics.

METHOD

From the US Department of Education Rehabilitation Service Administration Case Service Report (RSA-911) database, data from 3162 individuals with CP (1820 males [57.6%] and 1342 females [42.4% age range 16-54 y) whose cases were closed in 2009, were used in this study. A total of 1567 cases (49.6%) were closed with clients being categorized as 'successful employment' and 1595 cases (50.4%) were closed with clients being classified as unemployed.

RESULTS

Multivariate logistic regression was used to examine the relationship between services provided and work outcomes with regard to demographic characteristics. Males aged between 26 and 54 years old with higher education attainment were more likely to be employed. Individuals receiving disability benefits were less likely to be employed. After controlling for the effect of demographic and work disincentive variables, five vocational rehabilitation services significantly predicted employment outcomes (p<0.05), including (1) on-the-job training; (2) job placement assistance; (3) on-the-job support; (4) maintenance services; and (5) rehabilitation technology.

INTERPRETATION

Medical and health professionals need to be aware of vocational rehabilitation agencies as a resource for providing medical, psychological, educational, and vocational interventions for adults with CP to help them maximize their employability, to address their much needed work adjustment skills, to establish independent living, and to eventually reach their full potential in participation in society.

Cryoprotection of fibroblasts by carboxylated poly-L-lysine upon repeated freeze/thaw cycles

The cryoprotection of carboxylated h-poly-L-lysine (COOH-PLL) was investigated on fibroblasts [L-929 cells and human dermal fibroblasts (HDFs)] during multiple freeze/thaw cycles. COOH-PLL was not toxic to two fibroblast cell types even at 25% (w/v) concentration, whereas dimethylsulphoxide (DMSO) was highly toxic over 3.13% (v/v). When L-929 cells were subjected to 5 freeze/thaw cycles, the media containing 7.5% (w/v) COOH-PLL maintained cell morphology and significantly suppressed growth inhibition as well as cell detachment (P < 0.05). The result was comparable to the media containing 10% (v/v) DMSO. For HDFs, COOH-PLL could effectively retain cell viability and proliferation against 3 freeze/thaw cycles. Cell viability of HDFs was decreased after 5 freeze/thaw cycles, but COOH-PLL exerted better cryoprotection. The cell type might account for the difference in the observations. The data demonstrated that COOH-PLL is a good cryoprotectant for mammalian cells against repeated freeze/thaw cycles, and may be used for cell preservation in fields of cell transplantation, tissue engineering and regenerative medicine.

Transcriptome analysis based on next-generation sequencing of non-model plants producing specialized metabolites of biotechnological interest

Plants produce a vast array of specialized metabolites, many of which are used as pharmaceuticals, flavors, fragrances, and other high-value fine chemicals. However, most of these compounds occur in non-model plants for which genomic sequence information is not yet available. The production of a large amount of nucleotide sequence data using next-generation technologies is now relatively fast and cost-effective, especially when using the latest Roche-454 and Illumina sequencers with enhanced base-calling accuracy. To investigate specialized metabolite biosynthesis in non-model plants we have established a data-mining framework, employing next-generation sequencing and computational algorithms, to construct and analyze the transcriptomes of 75 non-model plants that produce compounds of interest for biotechnological applications. After sequence assembly an extensive annotation approach was applied to assign functional information to over 800,000 putative transcripts. The annotation is based on direct searches against public databases, including RefSeq and InterPro. Gene Ontology (GO), Enzyme Commission (EC) annotations and associated Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway maps are also collected. As a proof-of-concept, the selection of biosynthetic gene candidates associated with six specialized metabolic pathways is described. A web-based BLAST server has been established to allow public access to assembled transcriptome databases for all 75 plant species of the PhytoMetaSyn Project (www.phytometasyn.ca).

Fast skeletal muscle troponin activation increases force of mouse fast skeletal muscle and ameliorates weakness due to nebulin-deficiency

The effect of the fast skeletal muscle troponin activator, CK-2066260, on calcium-induced force development was studied in skinned fast skeletal muscle fibers from wildtype (WT) and nebulin deficient (NEB KO) mice. Nebulin is a sarcomeric protein that when absent (NEB KO mouse) or present at low levels (nemaline myopathy (NM) patients with NEB mutations) causes muscle weakness. We studied the effect of fast skeletal troponin activation on WT muscle and tested whether it might be a therapeutic mechanism to increase muscle strength in nebulin deficient muscle. We measured tension-pCa relations with and without added CK-2066260. Maximal active tension in NEB KO tibialis cranialis fibers in the absence of CK-2066260 was ∼60% less than in WT fibers, consistent with earlier work. CK-2066260 shifted the tension-calcium relationship leftwards, with the largest relative increase (up to 8-fold) at low to intermediate calcium levels. This was a general effect that was present in both WT and NEB KO fiber bundles. At pCa levels above ∼6.0 (i.e., calcium concentrations <1 µM), CK-2066260 increased tension of NEB KO fibers to beyond that of WT fibers. Crossbridge cycling kinetics were studied by measuring k(tr) (rate constant of force redevelopment following a rapid shortening/restretch). CK-2066260 greatly increased k(tr) at submaximal activation levels in both WT and NEB KO fiber bundles. We also studied the sarcomere length (SL) dependence of the CK-2066260 effect (SL 2.1 µm and 2.6 µm) and found that in the NEB KO fibers, CK-2066260 had a larger effect on calcium sensitivity at the long SL. We conclude that fast skeletal muscle troponin activation increases force at submaximal activation in both wildtype and NEB KO fiber bundles and, importantly, that this troponin activation is a potential therapeutic mechanism for increasing force in NM and other skeletal muscle diseases with loss of muscle strength.

The Connor-Davidson Resilience Scale as a Positive Psychology Measure for People With Spinal Cord Injuries

The main objective of this study is to evaluate the measurement structure of the Connor-Davidson Resilience Scale (CD-RISC) as a positive psychology measure for people with spinal cord injuries (SCIs) using confirmatory factor analysis. The participants consisted of 274 Canadians with SCI living in the community. The result indicated that the 5-factor intercorrelated model fits the data reasonably well (χ2 = 635.20; p value < .001; χ2/df = 2.40; CFI = .90; RMSEA = 0.07). These 5 factors (personal competence, high standards, and tenacity; trust in one’s instincts, tolerance of negative affect, and strengthening effects of stress; positive acceptance of change and secure relationships; control; and spiritual influence) correlated positively with disability acceptance and happiness, and inversely related to depression. The reliability of the 5 subscales was good ranging from .65 to .92. In conclusion, the results of this study confirmed that the 5-factor structure of the CD-RISC observed in the general population can be replicated in a sample of Canadians with SCI. This resilience scale can be used as a positive psychology measure in rehabilitation counseling research and practice.

Role of the phloem in the biochemistry and ecophysiology of benzylisoquinoline alkaloid metabolism

Benzylisoquinoline alkaloids (BIAs) are a diverse group of biologically active specialized metabolites produced mainly in four plant families. BIA metabolism is likely of monophyletic origin and involves multiple enzymes yielding structurally diverse compounds. Several BIAs possess defensive properties against pathogenic microorganisms and herbivores. Opium poppy (Papaver somniferum: Papaveraceae) has emerged as a model system to investigate the cellular localization of BIA biosynthesis. Although alkaloids accumulate in the laticifer cytoplasm (latex) of opium poppy, corresponding biosynthetic enzymes and gene transcripts are localized to proximal sieve elements and companion cells, respectively. In contrast, BIA metabolism in the non-laticiferous meadow rue (Thalictrum flavum; Ranunculaceae) occurs independent of the phloem. Evidence points toward the adoption of diverse strategies for the biosynthesis and accumulation of alkaloids as defensive compounds. Recruitment of cell types involved in BIA metabolism, both within and external to the phloem, was likely driven by selection pressures unique to different taxa. The biochemistry, cell biology, ecophysiology, and evolution of BIA metabolism are considered in this context.

Abstract P6-01-05: Enhancement of18F-FDG uptake and glycolysis by epidermal growth factor via PI3K activation in T47D breast cancer cells

It is well known that the binding of epidermal growth factor (EGF) to EGF receptors (EGFR) stimulates proliferation of breast cancer cells via activation of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) signaling pathways. There was a report that glucose consumption and lactate production were increased in MDA-MB-468 breast cancer cells following EGF exposure. However, the effect of EGF in enhancing glucose uptake and signaling pathways that are involved have not been clearly revealed. We thus investigated the role of EGF in stimulation of18F-FDG uptake in T47D breast cancer cells, and further elucidated the molecular mechanisms that are involved.

Exposure of T47D cells to 100 ng/mL EGF for 24 h caused a substantial augmentation of18F-FDG uptake to even greater extents to 310.8% ± 30.1% of control cells (P &lt; 0.001), and this effect of EGF showed dose- and time-dependency. Increased glucose uptake by EGF occurred through enhanced membrane GLUT-1 expression as well as hexokinase activity. Inhibition experiments with cycloheximide showed that the metabolic effect by EGF required new protein biosynthesis. Stimulation of glucose uptake by EGF was dependent on sufficient EGFR expression because18F-FDG uptake in MCF-7 cells weakly expressing EGFR was not affected by EGF treatment. Although EGF was also a stimulator of T47D cell proliferation (137.3 ± 7.3% of basal levels at 24 h, P &lt; 0.001), the metabolic effect occurred in a manner that clearly preceded and surpassed the proliferative effect. EGF-stimulated proliferation was significantly inhibited by the EGFR inhibitor BIBX1382, the PI3K inhibitor LY294002 and the specific MAPK inhibitor PD98059. Unlike proliferation, the ability of EGF to augment18F-FDG uptake was found to be dependent on PI3K but not on MAPK activity.

These findings yield the insight into our understanding of the role of EGF and the molecular basis that are involved in glucose metabolism of breast cancer cells.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-01-05.

Calcium sensitivity and myofilament lattice structure in titin N2B KO mice

The cellular basis of the Frank-Starling "Law of the Heart" is the length-dependence of activation, but the mechanisms by which the sarcomere detects length changes and converts this information to altered calcium sensitivity has remained elusive. Here the effect of titin-based passive tension on the length-dependence of activation (LDA) was studied by measuring the tension-pCa relation in skinned mouse LV muscle at two sarcomere lengths (SLs). N2B KO myocardium, where the N2B spring element in titin is deleted and passive tension is elevated, was compared to WT myocardium. Myofilament lattice structure was studied with low-angle X-ray diffraction; the myofilament lattice spacing (d1,0) was measured as well as the ratio of the intensities of the 1,1 and 1,0 diffraction peaks (I1,1/I1,0) as an estimate of the degree of association of myosin heads with the thin filaments. Experiments were carried out in skinned muscle in which the lattice spacing was reduced with Dextran-T500. Experiments with and without lattice compression were also carried out following PKA phosphorylation of the skinned muscle. Under all conditions that were tested, LDA was significantly larger in N2B KO myocardium compared to WT myocardium, with the largest differences following PKA phosphorylation. A positive correlation between passive tension and LDA was found that persisted when the myofilament lattice was compressed with Dextran and that was enhanced following PKA phosphorylation. Low-angle X-ray diffraction revealed a shift in mass from thin filaments to thick filaments as sarcomere length was increased. Furthermore, a positive correlation was obtained between myofilament lattice spacing and passive tension and the change in I1,1/I1,0 and passive tension and these provide possible explanations for how titin-based passive tension might regulate calcium sensitivity.

Factors affecting the relative abundance of nuclear copies of mitochondrial DNA (numts) in hominoids

Although nuclear copies of mitochondrial DNA (numts) can originate from any portion of the mitochondrial genome, evidence from humans suggests that more variable parts of the mitochondrial genome, such as the mitochondrial control region (MCR), are under-represented in the nucleus. This apparent deficit might arise from the erosion of sequence identity in numts originating from rapidly evolving mitochondrial sequences. However, the extent to which mitochondrial sequence properties impacts the number of numts detected in genomic surveys has not been evaluated. In order to address this question, we: (1) conducted exhaustive BLAST searches of MCR numts in three hominoid genomes; (2) assessed numt prevalence across the four MCR sub-domains (HV1, CCD, HV2, and MCR(F)); (3) estimated their insertion rates in great apes (Hominoidea); and (4) examined the relationship between mitochondrial DNA variability and numt prevalence in sequences originating from MCR and coding regions of the mitochondrial genome. Results indicate a marked deficit of numts from HV2 and MCR(F) MCR sub-domains in all three species. These MCR sub-domains exhibited the highest proportion of variable sites and the lowest number of detected numts per mitochondrial site. Variation in MCR insertion rate between lineages was also observed with a pronounced burst in recent integrations within chimpanzees and orangutans. A deficit of numts from HV2/MCR(F) was observed regardless of age, whereas HV1 is under-represented only in older numts (>25 million years). Finally, more variable mitochondrial genes also exhibit a lower identity with nuclear copies and because of this, appear to be under-represented in human numt databases.

Pulmonary alveolar microlithiasis in an alpaca (Vicugna pacos)

Pulmonary alveolar microlithiasis (PAM) is a rare, familial disease of unknown aetiology characterised by intra-alveolar formation and accumulation of microliths. Multiple formalin-fixed tissues were submitted from a 5-month-old female alpaca that died suddenly without significant clinical signs. No gross abnormalities were observed on postmortem examination. Histological findings included PAM and severe centrilobular hepatic necrosis. Although the hepatic lesion was the likely cause of death, PAM was an incidental finding that has not been reported previously in alpacas. An overview of PAM, including pathogenesis and histopathological characteristics, are discussed in relation to the concurrent hepatic disease in the present case.