Association between glucose dips and the feeling of hunger in a dietary intervention study among students with early and late chronotype-secondary analysis of a randomized cross-over nutrition trial.

Consumption of foods with high glycaemic index (GI) can cause hyperglycemia, thus increasing postprandial hunger. Since circadian rhythm differs inter-individually, we describe glucose dips after breakfast/dinner with high/medium estimated meal GI among students with early (n = 22) and late chronotype (n = 23) and examine their relation to the feeling of hunger in a secondary analysis of a randomized cross-over nutrition trial. Glucose dips reflect the difference between the lowest glucose value recorded 2-3 h postprandially and baseline, presented as percentage of average baseline level. Associations between glucose dips and the feeling of hunger were analyzed using multilevel linear models. Glucose dips were lower after medium GI meals than after high GI meals among both chronotype groups (p = 0.03). Among early chronotypes, but not among late chronotypes, glucose dip values were lower after breakfast than after dinner (-4.9 % vs. 5.5 %, p = 0.001). Hunger increased throughout the day among both chronotypes but glucose dips were not related to the feeling of hunger at the meal following breakfast. Interestingly, lower glucose dip values 2-3 h postprandially occurred particularly after medium GI meals and were seen after breakfast among early chronotypes. These glucose dips did not predict hunger at meals after breakfast.

Associations of chronotype and social jetlag with eating jetlag and their changes among German students during the first COVID-19 lockdown. The Chronotype and Nutrition study.

Due to their biologically later chronotype, young students are vulnerable to a discrepant sleeping pattern between work- and free days, coined social jetlag (SJL). This study examined whether a later chronotype and/or a larger SJL are related to an analogous discrepancy in meal timing defined as eating jetlag (EJL) and whether chronotype and/or changes in SJL during the first COVID-19 related lockdown in Germany associated with changes in EJL. Baseline data were collected from September 2019-January 2020 among 317 students (58% females) aged 18-25 years of which a total of 156 students (67% females) completed an online follow-up survey in June-July 2020 (1st lockdown). Data were collected on daily routines, timing of meals/snacks, and physical activity. Chronotype was determined using the Munich ChronoType Questionnaire; SJL and EJL correspond to the difference in the daily midpoint of sleep/eating duration between work- and free days. Multivariable linear regression revealed that students with a later chronotype or a larger SJL experienced a larger EJL (padjusted = 0.0124 and padjusted<0.0001). A later chronotype at baseline and reductions in SJL during lockdown associated with concurrent reductions in EJL (padjusted = 0.027 and padjusted<0.0001). In conclusion, students with a later chronotype exhibit a more erratic meal pattern, which associates with SJL. During lockdown, flexible daily schedules allowed students to align the meal timing with their inner clock.

Microsurgical treatment for unruptured intracranial aneurysms: a modern single surgeon series.

With the rise of endovascular treatments for the management of unruptured intracranial aneurysms (UIAs), advances in microsurgical techniques are underrepresented in modern surgical series, which largely consist of patients with aneurysms unfit for coiling. We report a modern series of microsurgical treatment for UIAs performed by a single surgeon as the preferred treatment modality. We retrospectively reviewed the charts of all patients with UIAs treated by the senior author with microsurgical clipping over an 11-year period. Procedure-related mortality, major neurologic morbidity (modified Rankin Score 3-5), complications, and persistent neurologic deficits were recorded. Risk factors for persistent neurologic deficits and major morbidity or mortality were analyzed using multivariate logistic regression analysis. We identified 329 patients with 400 UIAs treated in 353 surgeries. The average age was 52 years, 80% of patients were women, and 13% had a previous subarachnoid hemorrhage. The average aneurysm size was 7 mm and 92% were in the anterior circulation. The mean follow-up was 15 months (range 0.5-125). There was one procedure-related death (0.3%), and two patients suffered major morbidity (0.6%). Twenty procedures (5.6%) resulted in a persistent neurologic deficit. Risk factors for death and major morbidity were increasing age and posterior circulation, while risk factors for persistent neurologic deficits were increasing aneurysm size and posterior circulation. We conclude that microsurgical clipping is safe, effective, and should be given strong consideration as the primary treatment modality for younger patients with small to medium sized UIAs in the anterior circulation.

A viral microRNA downregulates metastasis suppressor CD82 and induces cell invasion and angiogenesis by activating the c-Met signaling.

Kaposi's sarcoma (KS) as the most common AIDS-associated malignancy is etiologically caused by KS-associated herpesvirus (KSHV). KS is a highly disseminated and vascularized tumor. KSHV encodes 12 pre-microRNAs that yield 25 mature microRNAs (miRNAs), but their roles in KSHV-induced tumor metastasis and angiogenesis remain largely unclear. KSHV-encoded miR-K12-6 (miR-K6) can generate two mature miRNAs, miR-K6-5p and miR-K6-3p. Recently, we have shown that miR-K6-3p induced cell migration and angiogenesis via directly targeting SH3 domain binding glutamate-rich protein (SH3BGR). Here, by using mass spectrometry, bioinformatics analysis and luciferase reporter assay, we showed that miR-K6-5p directly targeted the coding sequence of CD82 molecule (CD82), a metastasis suppressor. Ectopic expression of miR-K6-5p specifically inhibited the expression of endogenous CD82 and strongly promoted endothelial cells invasion and angiogenesis. Overexpression of CD82 significantly inhibited cell invasion and angiogenesis induced by miR-K6-5p. Mechanistically, CD82 directly interacted with c-Met to inhibit its activation. MiR-K6-5p directly repressed CD82, relieving its inhibition on c-Met activation and inducing cell invasion and angiogenesis. Lack of miR-K6 abrogated KSHV suppression of CD82 resulting in compromised KSHV activation of c-Met pathway, and KSHV induction of cell invasion and angiogenesis. In conclusion, our data show that by reducing CD82, KSHV miR-K6-5p expedites cell invasion and angiogenesis by activating the c-Met pathway. Our findings illustrate that KSHV miRNAs may be critical for the dissemination and angiogenesis of KSHV-induced malignant tumors.

Lithium-doping inverts the nanoscale electric field at the grain boundaries in Cu2ZnSn(S,Se)4 and increases photovoltaic efficiency.

Passive grain boundaries (GBs) are essential for polycrystalline solar cells to reach high efficiency. However, the GBs in Cu2ZnSn(S,Se)4 have less favorable defect chemistry compared to CuInGaSe2. Here, using scanning probe microscopy we show that lithium doping of Cu2ZnSn(S,Se)4 changes the polarity of the electric field at the GB such that minority carrier electrons are repelled from the GB. Solar cells with lithium-doping show improved performance and yield a new efficiency record of 11.8% for hydrazine-free solution-processed Cu2ZnSn(S,Se)4. We propose that lithium competes for copper vacancies (forming benign isoelectronic LiCu defects) decreasing the concentration of ZnCu donors and competes for zinc vacancies (forming a LiZn acceptor that is likely shallower than CuZn). Both phenomena may explain the order of magnitude increase in conductivity. Further, the effects of lithium doping reported here establish that extrinsic species are able to alter the nanoscale electric fields near the GBs in Cu2ZnSn(S,Se)4. This will be essential for this low-cost Earth abundant element semiconductor to achieve efficiencies that compete with CuInGaSe2 and CdTe.

Phase transitions in calcium nitrate thin films.

Calcium carbonate is a ubiquitous mineral and its reactivity with indoor and outdoor air pollutants will contribute to the deterioration of these materials through the formation of salts that deliquesce at low relative humidity (RH). As shown here for calcium nitrate thin films, deliquescence occurs at even lower relative humidity than expected from bulk thermodynamics and lower than the recommended humidity for the preservation of artifacts and antiques.

Molecular dynamics simulations of a highly charged peptide from an SH3 domain: possible sequence-function relationship.

A seven-residue peptide that is highly conserved in SH3 domains despite being far from the active site has been shown by NMR to be stable in solution. This peptide, biologically important because it is a likely folding nucleus for SH3 domains, provides a challenging subject for molecular dynamics because it is highly charged. We present stable, 10-ns simulations of both the native-like diverging turn structure and a helical model. Free energies of these two conformations, estimated through MM-PBSA analysis using several force fields, suggest a comparable free energy (DeltaDeltaG < or =6 kcal/mol) for native and helix conformations. NOE intensities calculated from the native trajectory reproduce experimental data quite well, suggesting that the conformations sampled by the trajectory reasonably represent those observed in the NMR experiment. The molecular dynamics results, as well as sequence analysis of a diverse 690-member family of SH3 domain proteins, suggest that the presence of two elements is essential for formation of the diverging turn structure: a pair of residues with low helical propensity in the turn region and, as previously recognized, two hydrophobic residues to close the end of the diverging turn. Thus, these two sequence features may form the structural basis for the function of this peptide as a folding nucleus in this family of proteins.

Energy transfer in the peridinin chlorophyll-a protein of Amphidinium carterae studied by polarized transient absorption and target analysis.

The peridinin chlorophyll-a protein (PCP) of dinoflagellates differs from the well-studied light-harvesting complexes of purple bacteria and green plants in its large (4:1) carotenoid to chlorophyll ratio and the unusual properties of its primary pigment, the carotenoid peridinin. We utilized ultrafast polarized transient absorption spectroscopy to examine the flow of energy in PCP after initial excitation into the strongly allowed peridinin S2 state. Global and target analysis of the isotropic and anisotropic decays reveals that significant excitation (25-50%) is transferred to chlorophyll-a directly from the peridinin S2 state. Because of overlapping positive and negative features, this pathway was unseen in earlier single-wavelength experiments. In addition, the anisotropy remains constant and high in the peridinin population, indicating that energy transfer from peridinin to peridinin represents a minor or negligible pathway. The carotenoids are also coupled directly to chlorophyll-a via a low-lying singlet state S1 or the recently identified SCT. We model this energy transfer time scale as 2.3 +/- 0.2 ps, driven by a coupling of approximately 47 cm(-1). This coupling strength allows us to estimate that the peridinin S1/SCT donor state transition moment is approximately 3 D.

Role of founder cell deficit and delayed neuronogenesis in microencephaly of the trisomy 16 mouse.

Development of the neocortex of the trisomy 16 (Ts16) mouse, an animal model of Down syndrome (DS), is characterized by a transient delay in the radial expansion of the cortical wall and a persistent reduction in cortical volume. Here we show that at each cell cycle during neuronogenesis, a smaller proportion of Ts16 progenitors exit the cell cycle than do control, euploid progenitors. In addition, the cell cycle duration was found to be longer in Ts16 than in euploid progenitors, the Ts16 growth fraction was reduced, and an increase in apoptosis was observed in both proliferative and postmitotic zones of the developing Ts16 neocortical wall. Incorporation of these changes into a model of neuronogenesis indicates that they are sufficient to account for the observed delay in radial expansion. In addition, the number of neocortical founder cells, i.e., precursors present just before neuronogenesis begins, is reduced by 26% in Ts16 mice, leading to a reduction in overall cortical size at the end of Ts16 neuronogenesis. Thus, altered proliferative characteristics during Ts16 neuronogenesis result in a delay in the generation of neocortical neurons, whereas the founder cell deficit leads to a proportional reduction in the overall number of neurons. Such prenatal perturbations in either the timing of neuron generation or the final number of neurons produced may lead to significant neocortical abnormalities such as those found in DS.

Organotypic slice cultures for analysis of proliferation, cell death, and migration in the embryonic neocortex.

Dynamic cellular interactions during neocortical neurogenesis are critical for proper cortical development, providing both trophic and tropic support. Although cell proliferation and programmed cell death have been characterized in dissociated primary cell cultures, many in vivo processes during cortical neurogenesis depend on cell-cell interactions and therefore on the three-dimensional environment of the proliferating neuroblasts and their progeny. Here we describe a murine organotypic neocortical slice preparation that retains major morphological and functional in vivo characteristics of the developing neocortex and is viable (exhibits very low levels of cell death) for up to three days. Moreover, this slice preparation is amenable to direct experimental manipulation of potential diffusible regulators of neurogenesis. Using a variety of biochemical and physiological methods including time-lapse and quantitative confocal microscopy, we demonstrate that this system can be used effectively to investigate cellular mechanisms important for brain growth and maturation, including neurogenesis, apoptosis, and neuronal migration.

Neuronal apoptosis in mouse trisomy 16: mediation by caspases.

Hippocampal neurons from the trisomy 16 (Ts16) mouse, a potential animal model of Down's syndrome (trisomy 21) and neurodegenerative disorders such as Alzheimer's disease (AD), die at an accelerated rate in vitro. Here, we present evidence that the accelerated neuronal death in Ts16 occurs by apoptosis, as has been reported for neurons in AD. First, the nuclei of dying Ts16 neurons are pyknotic and undergo DNA fragmentation, as revealed by terminal transferase-mediated dUTP nick end-labeling. Second, the accelerated death of Ts16 neurons is prevented by inhibitors of the caspase family of proteases, which are thought to act at a late, obligatory step in the apoptosis pathway. In the presence of maximally effective concentrations of caspase inhibitors, Ts16 neuron survival was indistinguishable from that of control neurons. These results suggest that overexpression of one or more genes on mouse chromosome 16 leads to caspase-mediated apoptosis in Ts16 neurons.

MAP5 expression in proliferating neuroblasts.

MAP5, a microtubule-associated protein present in immature neurons, was found to be expressed in the embryonic mouse telencephalic ventricular zone (VZ). Since the VZ contains proliferating neuroblasts, the source of most of the neurons of the cerebral cortex, this observation raised the possibility that MAP5 is expressed by proliferating neuronal progenitors. MAP5-positive mitotic cells were observed at the ventricular surface, a finding consistent with progenitors expressing MAP5 prior to their last division. This possibility was investigated using dissociated, cortical cells in vitro by measuring the expression of MAP5 and the neuroepithelial marker nestin, together with the incorporation of bromodeoxyuridine (BrdU), a thymidine analogue that labels the DNA of proliferating cells in the S-phase of the cell cycle. All of the proliferating cells expressed nestin. A population of MAP5-positive cells was also found to incorporate BrdU; some cells expressed MAP5 within 30 min of BrdU labeling. The results suggest that uncommitted neuroblasts express only nestin, with expression of MAP5 occurring near the time the cell commits to become a postmitotic neuron after the next cell division. Subsequently, cells expressing both MAP5 and nestin leave the cell cycle and exit the VZ, lose nestin, and differentiate into neurons. Since some cells expressed MAP5 during or shortly after S-phase but before mitosis, MAP5 may be the earliest marker to identify neuronal progenitors that will become post-mitotic neurons following their next mitosis.

Intraurethral alprostadil for treatment of erectile dysfunction in patients with spinal cord injury.

OBJECTIVES: To assess the efficacy of intraurethral prostaglandin E1 (alprostadil, MUSE) in treating erectile dysfunction in patients with spinal cord injury (SCI). METHODS: Intraurethral alprostadil was tested in 15 patients with SCI to evaluate its effectiveness in treating SCI-associated erectile dysfunction. All patients were at least 1 year after injury, and all had previously used intracavernosal injections successfully (Schramek's grade 5 erection). The intraurethral drug was administered in the office, in the presence of a physician, with monitoring of blood pressure. If effective, the patient was then able to use MUSE at home. The first 3 patients underwent gradual dose escalation starting with 125 microg, without the use of a constriction ring. Because of hypotension, the remaining 12 patients all used a penile constriction ring prior to intraurethral drug administration using 1000 microg. The quality of the erection was compared with that achieved with intracavernosal injections using Schramek's grading. RESULTS: The dose escalation (titration) in the first 3 patients demonstrated that the 1000-microg dose was the most effective in creating an erectile response. Transient hypotension was noted in these first 3 patients in whom the constricting band was not used. The highest dose of MUSE (1000 microg) was, therefore, used in the remaining 12 patients, with the constriction band. The quality of the erection varied and appeared to be less rigid in all patients (12 patients with grade 1 to 3; 3 patients with grade 4) than that noted with intracavernosal injection therapy (1 5 patients with grade 5). There was no incidence of priapism. The 3 patients with grade 4 erections tried the MUSE at home. All 3 patients were dissatisfied with the quality of the erection and did not continue to use the MUSE at home and returned to intracavernosal injection therapy. CONCLUSIONS: MUSE appears to be somewhat effective in creating erections; however, these were less rigid erections than those obtained with intracavernosal therapy and provided less overall satisfaction. It should always be used in the patient with SCI after placement of a constriction ring to prevent hypotension. Its ultimate use depends on the patient's level of satisfaction with the quality of the erection compared with intracavernosal injections.

Impaired spatial working and reference memory in segmental trisomy (Ts65Dn) mice.

To evaluate the cognitive phenotype of the segmental trisomy 16 (Ts65Dn) mouse, a model of Down Syndrome (DS, trisomy 21), we assessed spatial working and reference memory using a 12-arm radial maze (RAM). Ts65Dn mice made a greater number of reference memory errors across trials compared to control mice. Both genotypes showed improvement across trials, although improvement was slower in Ts65Dn mice. Ts65Dn mice also made a greater number of working memory errors on the RAM, and in contrast to control mice, did not improve across trials, always performing at near-chance levels. These results provide evidence for both spatial working and reference memory deficits in Ts65Dn mice, characteristics of cognitive dysfunction.

Abnormal calcium homeostasis in astrocytes from the trisomy 16 mouse.

The regulation of intracellular Ca2+ was investigated in cultured astrocytes from the trisomy 16 (Ts16) mouse, an animal model for Down syndrome and Alzheimer's disease (AD). The cytoplasmic ionized Ca2+ concentration ([Ca2+]cyt) was determined using digital imaging of fura-2-loaded cells. The relative Ca2+ content of internal endoplasmic reticulum (ER) stores was estimated from the magnitude of the transient increase in [Ca2+]cyt induced by cyclopiazonic acid (CPA), an inhibitor of Ca2+ sequestration into ER stores. At rest, the average [Ca2+]cyt was 140 nM in euploid (normal) astrocytes, but over twice as high, 320 nM, in Ts16 cells. In the absence of extracellular Ca2+, CPA induced a transient increase in [Ca2+]cyt to over 1200 nM in Ts16 astrocytes as compared to only 500 nM in euploid cells, indicating an increased amount of Ca2+ in the Ts16 astrocyte ER. In contrast to euploid astrocytes, both resting [Ca2+]cyt and the amount of Ca2+ in the ER stores varied widely among individual Ts16 astrocytes. These results show that Ts16 produces a dysregulation of Ca2+ homeostasis leading to increased cytoplasmic and stored Ca2+. Since increases in [Ca2+]cyt have been implicated in the etiology of neurodegenerative diseases, including AD, this finding of abnormal Ca2+ homeostasis in a genetic model of human neurological disorders suggests that Ca2+ dysregulation may be a common feature underlying neurodegenerative processes.

Spatial memory deficits in segmental trisomic Ts65Dn mice.

Spatial memory was assessed in the segmental trisomic 16 mouse (Ts65Dn), a potential model for Down syndrome (DS), using the 12-arm radial maze (RAM). Ts65Dn mice have a portion of mouse chromosome 16 syntenic to the distal end of human chromosome 21 triplicated. On each of 8 daily trials of the RAM, Ts65Dn mice made fewer correct choices than control mice and performed at or near chance levels, indicating a deficit in spatial working memory. On trials 9 and 10, Ts65Dn mice performed as well as control mice on the initial 12 choices, but required a greater number of choices to complete the RAM. The improved performance of Ts65Dn mice on trials 9 and 10 was lost when the animals were retested after a 50-day retention period, suggesting that long-term memory is also defective. These results are not likely explained by differences in either response bias or perceptual discrimination. Ts65Dn and control mice displayed comparable levels of performance in spontaneous alternation in a T-maze, demonstrating that simple spatial memory was not impaired. In the elevated plus maze, Ts65Dn mice did not display higher anxiety levels which could affect their performance in the RAM. In fact, Ts65Dn mice visited open arms on the elevated plus maze more frequently and spent more time on open arms than did control mice. Taken together, these results provide evidence for short- and long-term spatial memory deficits in Ts65Dn mice.