Astaxanthin ameliorates heat stress-induced impairment of blastocyst development in vitro:--astaxanthin colocalization with and action on mitochondria--

PURPOSE

The effects of astaxanthin (Ax) on the in vitro development of bovine embryos cultured under heat stress were investigated in combination with the assessment of its cellular accumulation and action on mitochondrial membrane potential (ΔΨm).

METHODS

Bovine ≥8-cell embryos were collected on day 3 after in vitro fertilization and exposed to single (day 4) or repeated (day 4 and 5) heat stress (10 h/day at 40.5 °C). Ax was added into culture medium under the repeated heat stress and blastocyst development was evaluated. The cellular uptake of Ax in embryos was examined using bright-field and confocal laser-scanning microscopy, and high-performance liquid chromatography. The relationship between Ax and mitochondria localization was assessed using MitoTracker dye. The effects of Ax on ΔΨm were investigated using JC-1 dye.

RESULTS

Blastocyst development in the repeated heat stress treatment decreased significantly (P < 0.05) compared with those in single heat stress or normal thermal treatment. The addition of Ax into culture medium did lead to a significant recovery in blastocyst development in the repeated heat-treated group. Ax was detected in cytoplasm of embryos and observed to colocalize with mitochondria. Ax recovered ΔΨm in embryos that was decreased by the heat treatment.

CONCLUSIONS

Ax ameliorated the heat stress-induced impairment of blastocyst development. Our results suggest that the direct action of Ax on mitochondrial activity via cellular uptake is a mechanism of the ameliorating effects.

Visualization of lenticulostriate arteries by flow-sensitive black-blood MR angiography on a 1.5 T MRI system: a comparative study between subjects with and without stroke

BACKGROUND AND PURPOSE

The branches of the LSA are the main causative arteries for lacunar infarction, though the vascular changes are largely unknown. Herein, we examined the correlation of LSA imaging findings in patients with lacunar infarction compared with controls by using FSBB-MRA.

MATERIALS AND METHODS

Fifteen patients (9 men, 6 women; mean age, 73 years) with infarction at the basal ganglia and/or its vicinity were prospectively enrolled, and 12 aged-matched control subjects (6 men, 6 women; mean age, 68 years) were examined by using FSBB-MRA on a 1.5T MR imaging system. Total number and length of visualized LSA branches were compared by a 2-tailed 2-sample t test. Stepwise multiple regression analyses were performed, including hypertension, hyperlipidemia, smoking history, and diabetes mellitus after evaluation of their colinearity. P<.05 after correction for multiple comparisons was considered significant.

RESULTS

Patients with stroke had significantly fewer LSA branches (average, 6.3; 95% CI, 5.4-7.1) than controls (8.7; 95% CI, 7.8-9.5) (P=.0003). The total LSA lengths were 117 mm (95% CI, 96-138 mm) for patients with stroke and 162 mm (95% CI, 133-91 mm) for control subjects (P=.01). In stepwise multiple regression analysis, only the LSA branch numbers were significantly related to infarction (P=.0003), while only hypertension was significantly related to total LSA length (P=.0085).

CONCLUSIONS

Using FSBB-MRA to visualize LSA branches, we found a significant reduction in the numbers of LSA branches in patients with stroke, and hypertension was inversely related to total LSA length. FSBB is a promising method to investigate the LSA by using 1.5T MR imaging.

A study on how a 6-month aerobic exercise program can modify coronary risk factors depending on their severity in middle-aged sedentary women

It is well known that physical exercise can reduce coronary risk factors. But how an aerobic exercise modifies coronary risk factors in relation to severity and physical fitness is still controversial.Fifty-four middle-aged women (mean age, 55 years) completed a 6-month on-site and home-based anaerobic threshold-level exercise program. The changes in coronary risk factor profiles were observed during the pre-intervention and intervention periods. Before the intervention (during control period), most coronary risk factors showed a rather unfavorable trend. After the program, their mean body weight decreased from 56.7 to 55.7 kg (p>0.05) and the proportion of body fat from 30.9 to 27.9% (p>0.05) without any reduction in lean body mass. Systolic blood pressure (SBP) decreased from 129.0 to 125.0 mm Hg (p>0.05) and diastolic blood pressure from 79.5 to 76.6 mm Hg (p>0.05). Fasting plasma glucose (FPG) declined from 109.6 to 103.4 mg/dl (p>0.05). Changes in SBP and FPG were most remarkable in their respective worst tertile. Serum lipids improved only modestly. Maximum oxygen uptake increased from 23.6 to 26.1 ml/kg/min (p>0.01). However, no significant correlations were found between changes in coronary risk factors and those in physical fitness. We conclude that the 6-month aerobic exercise program would modify women's coronary risk factors depending on their initial values, probably independently of the changes in physical fitness.

Interpretation of ion-exchange chromatographic retention based on an electrical double-layer model

An ion-exchange chromatographic model based on the Stern-Gouy-Chapman electrical double-layer theory is presented. We assume several equilibria occurring at the surface of an ion-exchange resin, such as the ion-pair formation of counterions with an ion-exchange site, the adsorption of ions, and the ion-pair formation of an adsorbed ions with their counterions. These equilibria are affected by the potential at the planes (the surface and the Stern layer potential) where the reactions occur. In addition, the nonselective accumulation of ions in the diffuse layer is also taken into account. Based on the developed model and derived equations, the nature of log k'-log X (X is the concentration of an eluent ion) plots is investigated for various sets of parameters and is compared with that of possible experimental results. Three extreme cases can be distinguished:  (1) ion-pair-controlled, (2) adsorption-controlled, and (3) accumulation in the diffuse layer-controlled retention. Though log k'-log X plots, when they are studied over wide eluent concentration ranges (more than 2 orders), do not necessarily show precise linearity especially in the presence of eluent adsorption and extremely high eluent ion-pair formation, the linear regression analyses give negative unit slopes (within 10% deviations) for monovalent solute-eluent combinations. Since the deviation from linearity relation is mostly found in very low k' ranges (e.g., k' < 1), it is possible only in very limited cases to confirm nonlinearity experimentally. This may have mistakenly led to the idea that selectivity coefficients can be regarded as constants and thus the log k'-log X plots should be linear with the slope equal to (charge ratios) × (-1) in ion-exchange chromatographic experiments. The efficiency of the developed model is verified by its ability to predict experimental results, e.g., nonlinear log k'-log X plots, changes in separation factors with varying ion-exchange affinity of an eluent ion, adsorption isotherms at different salt concentration, etc.

Reduced-distortion diffusion MRI of the craniovertebral junction

BACKGROUND AND PURPOSE

CVJ lesion suffers from a high sensitivity to susceptibility and distortion artifacts, which sometimes makes diffusion image difficult to interpret. Our purpose was to evaluate the potential for diffusion MR imaging using RS-EPI compared with SS-EPI in the assessment of the CVJ.

MATERIALS AND METHODS

RS-EPI and SS-EPI DTI images were acquired from 10 healthy volunteers using 3T MRI with a 32-channel head coil. For both sequences, the following parameters were used: 1-mm(2) in-plane resolution; 3-mm section thickness; TR = 5200 ms; 1 acquisition at b = 0 and 12 different encoding directions at b = 1000 seconds/mm(2). The RS-EPI sequence scan time was 9.44 minutes (1 average). The SS-EPI sequence was 9.37 minutes (8 averages). Diffusion tensor calculation and image analysis were performed using DTIStudio software. Diffusion trace images and color-coded fiber orientation maps were evaluated by 2 independent readers for distortion and delineation of fine structure using a semiquantitative scale in selected landmark locations. The absolute distances between the temporal base and the cerebellar contour between the T2-weighted images and the diffusion trace images obtained with RS-EPI and SS-EPI were also compared.

RESULTS

The contours of the temporal lobe and cerebellum were better delineated and distortion artifacts were clearly reduced with the RS-EPI sequence. More fine structures were also visible in the brain stem and cerebellum with the RS-EPI sequence. The amount of distortion was significantly reduced with RS-EPI compared with SS-EPI (P < .01).

CONCLUSIONS

The RS-EPI DTI sequence was less prone to geometric distortion than the SS-EPI sequence and allowed a better delineation of CVJ internal structure. Although the acquisition time is still relatively long, the RS-EPI appears as a promising approach to perform DTI studies in CVJ lesions, such as brain stem ischemia, neurodegenerative diseases, brain and skull base tumors, or inflammation.

Evaluation of CT angiography for visualisation of the lenticulostriate artery: difference between normotensive and hypertensive patients

OBJECTIVE

High-resolution CT angiography (CTA) is currently available using multidetector row CT (MDCT); however, its use for small artery visualisation has been limited. To evaluate its capability, we investigated CTA visualisation for difference in number of the lenticulostriate artery (LSA) branches between normotensive and hypertensive patients, because hypertension is a major cause of LSA damage.

METHODS

This was a retrospective study evaluating cerebrovascular CTA at our hospital conducted from February 2008 to June 2009 under approval of the institutional review board. 117 patients (39 males and 78 females, 19-88 years old) were included. CTA was conducted using a 64 channel MDCT. Total numbers of LSA branches were examined for differences by age with regression analysis and the presence or absence of hypertension and/or aneurysm using two-sample t-tests. A p-value <0.016 was considered statistically significant after correction for multiple comparisons. A multiple variable analysis of three factors was also conducted.

RESULTS

The average number of LSA branches was 3.6 [95% confidence interval (CI) 3.0-4.1] and 4.4 (95% CI 4.1-4.7), respectively, for a patient with and without history of hypertension, and the difference was statistically significant (p=0.013). The difference was approximately one branch in the multiple variable analysis. No significant correlation was observed for age and no significant difference was observed for the presence or absence of aneurysms.

CONCLUSIONS

Contrast-enhanced CTA can visualise significant differences in the number of LSA branches among patients with and without hypertension. Advances in knowledge Current high-resolution CTA can visualise LSA well, which enables finding a difference in the LSA between normotensive subjects and hypertensive patients.

Whole-heart coronary MR angiography under a single breath-hold: a comparative study with respiratory-gated acquisition using a multi-element phased-array coil

AIM

To compare visualization using whole-heart coronary magnetic resonance angiography (CMRA) acquired during a single breath-hold (BH) with that using conventional respiratory-gated (RG) CMRA.

MATERIALS AND METHODS

The CMRAs of 14 healthy subjects under either BH or RG conditions were studied using a 1.5 T system equipped with a whole-body phased-array coil and 16-channel receivers. The BH examination was accelerated using parallel imaging (PI) by factors of 2.5 and 2 in the phase and section directions, respectively. For the RG examination, a PI factor of 2 was used only in the phase direction. The visualization quality of 15 coronary segments using each condition was evaluated with a five-point scale (0-4). Differences between two conditions were compared at segments with an average score greater than 2 in RG-CMRA.

RESULTS

The average examination time for BH and RG acquisition scans was 34 s and 11 min 31 s, respectively. Ten segments (segments 1-3, 5-9, 11, and 13) had average scores higher than 2 in RG-CMRA. Of these, BH-CMRA had significantly lower scores than RG-CMRA at six segments (segments 1, 5-8, and 11) after correction for multiple comparisons (p<0.005). However, in BH-CMRA, proximal segments (segments 1-2, 5-7, and 11) showed average scores over 2, indicating marginally acceptable image quality.

CONCLUSION

Compared with the relatively limited degree of image degradation with RG-CMRA, the present data suggest that BH-CMRA would be useful for screening and as an adjunct to RG-CMRA that is occasionally incomplete.

Local and retrograde gene transfer into primate neuronal pathways via adeno-associated virus serotype 8 and 9

Viral vector-mediated gene transfer has become increasingly valuable for primate brain research, in particular for application of genetic methods (e.g. optogenetics) to study neuronal circuit functions. Neuronal cell tropisms and infection patterns are viable options for obtaining viral vector-mediated transgene delivery that is selective for particular neuronal pathways. For example, several types of viral vectors can infect axon terminals (retrograde infections), which enables targeted transgene delivery to neurons that directly project to a particular viral injection region. Although recent studies in rodents have demonstrated that adeno-associated virus serotype 8 (AAV8) and 9 (AAV9) efficiently transduce neurons, the tropisms and infection patterns remain poorly understood in primate brains. Here, we constructed recombinant AAV8 or AAV9, which expressed an enhanced green fluorescent protein (EGFP) gene driven by a ubiquitous promoter (AAV8-EGFP and AAV9-EGFP, respectively), and stereotaxically injected it into several brain regions in marmosets and macaque monkeys. Immunohistochemical analyses revealed almost exclusive colocalization of EGFP fluorescence via AAV9-mediated gene transfer with a neuron-specific marker, indicating endogenous neuronal tropism of AAV9, which was consistent with our previous results utilizing AAV8. Injections of either AAV8-EGFP or AAV9-EGFP into the marmoset striatum resulted in EGFP expression in local striatal neurons as a result of local infection, as well as expression in dopaminergic neurons of the substantia nigra via retrograde transport along nigrostriatal axonal projections. Retrograde infections were also observed in the frontal cortex and thalamus, which are known to have direct projections to the striatum. These local and retrograde gene transfers were further demonstrated in the geniculocortical pathway of the marmoset visual system. These findings indicate promising capabilities of AAV8 and AAV9 to deliver molecular tools into a range of primate neural systems in pathway-specific manners through their neuronal tropisms and infection patterns.

Toll-like receptor 4-dependent adjuvant activity of Kakkon-to extract exists in the high molecular weight polysaccharide fraction

Kakkon-to, a traditional herbal medicine (Kampo formula), has been used historically in China and Japan for the treatment of infectious diseases such as influenza and the common cold. However, the biological mechanism of its therapeutic action has not yet been elucidated. In this study, we investigated the immunological function of Kakkon-to and found that the high molecular weight fraction of the extract activated macrophages in vitro. This fraction was found to be composed primarily of saccharides and in vitro intensively stimulated mouse peritoneal macrophages that produce Th1 inflammatory cytokines such as tumor necrosis factor α (TNFalpha), interleukin-1beta (IL-1beta), interferon-gamma (IFN-gamma), and interleukin-6 (IL-6). The fraction did not activate macrophages from C3H/HeJ lacking Toll-like receptor 4 (TLR4) or MyD88-deficient mice, indicating that macrophage activation by the fraction was mediated by TLR4. The route of administration of the fraction into mice regulated the kinetics of TNFalpha production in immune organs. Intravenous administration induced TNFalpha production in the four target organs of spleen, liver, lung, and Peyer’s patch; however, the most abundant production occurred in the liver and peaked at 30-60 min post administration. Peritoneal administration induced similar kinetics but the most abundant production occurred in the spleen. In contrast, oral administration induced TNFalpha production in the liver, lung, and Peyer’s patch, but not in the spleen. Although liver and lung are TNFalpha-abundant organs, production peaks in these organs occurred later than in Peyer’s patch. We also found that the fraction induced antibody production as an adjuvant against a specific antigen ovalbumin (OVA) when administered simultaneously and subcutaneously in a dose-dependent manner. Interestingly, the fraction induced IgG-class antibody in response to low doses of the antigen, which induced only IgM-class antibody when administered alone, suggesting that the fraction induces a class switch of immunoglobulin as an adjuvant in vivo. The high molecular weight fraction of Kakkon-to extract could be applicable as a potent immunostimulating drug and adjuvant.

In vivo delivery of interferon-α gene enhances tumor immunity and suppresses immunotolerance in reconstituted lymphopenic hosts

T cells recognize tumor-associated antigens under the condition of lymphopenia-induced homeostatic proliferation (HP); however, HP-driven antitumor responses gradually decay in association with tumor growth. Type I interferon (IFN) has important roles in regulating the innate and adaptive immune system. In this study we examined whether a tumor-specific immune response induced by IFN-α could enhance and sustain HP-induced antitumor immunity. An intratumoral IFN-α gene transfer resulted in marked tumor suppression when administered in the early period of syngeneic hematopoietic stem cell transplantation (synHSCT), and was evident even in distant tumors that were not transduced with the IFN-α vector. The intratumoral delivery of the IFN-α gene promoted the maturation of CD11c(+) cells in the tumors and effectively augmented the antigen-presentation capacity of the cells. An analysis of the cytokine profile showed that the CD11c(+) cells in the treated tumors secreted a large amount of immune-stimulatory cytokines including interleukin (IL)-6. The CD11c(+) cells rescued effector T-cell proliferation from regulatory T-cell-mediated suppression, and IL-6 may have a dominant role in this phenomenon. The intratumoral IFN-α gene transfer creates an environment strongly supporting the enhancement of antitumor immunity in reconstituted lymphopenic recipients through the induction of tumor-specific immunity and suppression of immunotolerance.