Deletion of Tbc1d4/As160 abrogates cardiac glucose uptake and increases myocardial damage after ischemia/reperfusion.

BACKGROUND: Type 2 Diabetes mellitus (T2DM) is a major risk factor for cardiovascular disease and associated with poor outcome after myocardial infarction (MI). In T2DM, cardiac metabolic flexibility, i.e. the switch between carbohydrates and lipids as energy source, is disturbed. The RabGTPase-activating protein TBC1D4 represents a crucial regulator of insulin-stimulated glucose uptake in skeletal muscle by controlling glucose transporter GLUT4 translocation. A human loss-of-function mutation in TBC1D4 is associated with impaired glycemic control and elevated T2DM risk. The study's aim was to investigate TBC1D4 function in cardiac substrate metabolism and adaptation to MI. METHODS: Cardiac glucose metabolism of male Tbc1d4-deficient (D4KO) and wild type (WT) mice was characterized using in vivo [18F]-FDG PET imaging after glucose injection and ex vivo basal/insulin-stimulated [3H]-2-deoxyglucose uptake in left ventricular (LV) papillary muscle. Mice were subjected to cardiac ischemia/reperfusion (I/R). Heart structure and function were analyzed until 3 weeks post-MI using echocardiography, morphometric and ultrastructural analysis of heart sections, complemented by whole heart transcriptome and protein measurements. RESULTS: Tbc1d4-knockout abolished insulin-stimulated glucose uptake in ex vivo LV papillary muscle and in vivo cardiac glucose uptake after glucose injection, accompanied by a marked reduction of GLUT4. Basal cardiac glucose uptake and GLUT1 abundance were not changed compared to WT controls. D4KO mice showed mild impairments in glycemia but normal cardiac function. However, after I/R D4KO mice showed progressively increased LV endsystolic volume and substantially increased infarction area compared to WT controls. Cardiac transcriptome analysis revealed upregulation of the unfolded protein response via ATF4/eIF2α in D4KO mice at baseline. Transmission electron microscopy revealed largely increased extracellular matrix (ECM) area, in line with decreased cardiac expression of matrix metalloproteinases of D4KO mice. CONCLUSIONS: TBC1D4 is essential for insulin-stimulated cardiac glucose uptake and metabolic flexibility. Tbc1d4-deficiency results in elevated cardiac endoplasmic reticulum (ER)-stress response, increased deposition of ECM and aggravated cardiac damage following MI. Hence, impaired TBC1D4 signaling contributes to poor outcome after MI.

Psychiatric diagnostic dilemmas among people with intellectual and developmental disabilities.

BACKGROUND: Research regarding the accuracy of co-morbid psychiatric diagnoses in individuals with intellectual and developmental disabilities (IDD) is sparse. Yet correct diagnostic assignment is vital so that effective and appropriate treatment can be implemented, especially for the large numbers of individuals requiring expensive and restrictive behavioural health crisis services. METHOD: A retrospective review of de-identified data from multidisciplinary specialty team assessments completed for 50 individuals with ID (IntellectualDisability) with and without ASD and unresolved behavioural health challenges was conducted. The accuracy and reliability of the psychiatric diagnoses upon referral were compared with the diagnoses after the comprehensive team evaluation, and within-individual diagnostic agreement was calculated. The agreement between the Mood and Anxiety Semi-Structured interview tool (MASS) and the full team evaluation was also calculated. The influence of demographic and clinical characteristics on diagnostic agreement was explored. RESULTS: The most common chief complaints upon referral were aggression to others and self-injurious behaviour. Individuals were taking a median of six medications (interquartile range: 5 to 7); 80% were taking an antipsychotic medication. The most common medical conditions were constipation (70%) and gastroesophageal reflux disease (52%). Measures of interrater reliability of the referral diagnoses with the team assessment were below 0.5 (kappa range: -0.04 to 0.39), with the exception of ruling out dementia (kappa = 0.85). The interrater reliability estimates for the MASS evaluations for depression and anxiety were higher (kappa = 0.69 and 0.64) and reflected higher sensitivity and PPV. The odds of any referral diagnosis being confirmed by team evaluation were low: 0.25 (range: 0 to 0.67). The level of diagnostic agreement for each patient was not significantly attributable to demographic or clinical characteristics, although effect sizes indicate a possible positive relationship to age and the number of prescribed psychotropic medications at referral. CONCLUSION: Individuals in the current study had serious psychiatric and behavioural problems despite psychiatric care in their communities. The majority of psychiatric diagnoses provided upon referral were not supported by the multidisciplinary specialty team's assessment. In addition to possible diagnostic inaccuracy, the group in the study suffered from multiple medical co-morbidities and were exposed to polypharmacy. Results emphasise the importance of multidisciplinary evaluation by clinicians with expertise in neurodevelopmental disabilities when people with ID with and without ASD have complex behavioural health needs that are unresponsive to usual care. In addition, based on agreement with the full team evaluation, the MASS shows promise as an assessment tool, especially with regards to identifying anxiety and depression.

Microstructural and tensile properties of elastin-based polypeptides crosslinked with genipin and pyrroloquinoline quinone.

Elastin is an elastomeric, self-assembling extracellular matrix protein with potential for use in biomaterials applications. Here, we compare the microstructural and tensile properties of the elastin-based recombinant polypeptide (EP) EP20-244 crosslinked with either genipin (GP) or pyrroloquinoline quinone (PQQ). Recombinant EP-based sheets were produced via coacervation and subsequent crosslinking. The micron-scale topography of the GP-crosslinked sheets examined with atomic force microscopy revealed the presence of extensive mottling compared with that of the PQQ-crosslinked sheets, which were comparatively smoother. Confocal microscopy showed that the subsurface porosity in the GP-crosslinked sheets was much more open. GP-crosslinked EP-based sheets exhibited significantly greater tensile strength (P < or = 0.05). Mechanistically, GP appears to yield a higher crosslink density than PQQ, likely due to its capacity to form short-range and long-range crosslinks. In conclusion, GP is able to strongly modulate the microstructural and mechanical properties of elastin-based polypeptide biomaterials forming membranes with mechanical properties similar to native insoluble elastin.

Some physical and microstructural properties of genipin-crosslinked gelatin-maltodextrin hydrogels.

The physical properties and microstructure of gelatin-maltodextrin hydrogels fixed with genipin (GP) were investigated as a function of pH (3-7), maltodextrin (MD) (0-9%, w/w) and GP (0-10 mM levels), at a constant gelatin (G) concentration (10%, w/w). Network strength (elastic modulus, E) and swelling behavior were characterized by large deformation testing and by swelling index (SI). In general, network strength increased and swelling decreased at higher pH, MD and GP levels, except at pH 3, where E was independent of the GP concentration until approximately 7.5 mM, above which it declined. Confocal scanning laser microscopy (CLSM) images showed phase separation to be suppressed at pH 3, whereas at pH 7, separation into a self-similar dispersed phase was apparent. Overall, the judicious use of GP to crosslink G was an appropriate means of kinetically trapping MD within the gelatin network.

Lesion site patterns in severe, nonverbal aphasia to predict outcome with a computer-assisted treatment program.

OBJECTIVE: To test whether lesion site patterns in patients with chronic, severe aphasia who have no meaningful spontaneous speech are predictive of outcome following treatment with a nonverbal, icon-based computer-assisted visual communication (C-ViC) program. DESIGN: Retrospective study in which computed tomographic scans performed 3 months after onset of stroke and aphasia test scores obtained before C-ViC therapy were reviewed for patients after receiving C-ViC treatment. SETTING: A neurology department and speech pathology service of a Department of Veterans Affairs medical center and a university aphasia research center. PATIENTS: Seventeen patients with stroke and severe aphasia who began treatment with C-ViC from 3 months to 10 years after onset of stroke. MAIN OUTCOME MEASURE: Level of ability to use C-ViC on a personal computer to communicate. RESULTS: All patients with bilateral lesions failed to learn C-ViC. For patients with unilateral left hemisphere lesion sites, statistical analyses accurately discriminated between those who could initiate communication with C-ViC from those who were only able to answer directed questions. The critical lesion areas involved temporal lobe structures (Wernicke cortical area and the subcortical temporal isthmus), supraventricular frontal lobe structures (supplementary motor area or cingulate gyrus 24), and the subcortical medial subcallosal fasciculus, deep to the Broca area. Specific lesion sites were also identified for appropriate candidacy for C-ViC. CONCLUSIONS: Lesion site patterns on computed tomographic scans are helpful to define candidacy for C-ViC training, and to predict outcome level. A practical method is presented for clinical application of these lesion site results in combination with aphasia test scores.