200 research outputs found
Comparison of coronary hemodynamics in patients with internal mammary artery and saphenous vein coronary artery bypass grafts: A noninvasive approach using combined two-dimensional and Doppler echocardiography
AbstractBlood flow in bypass grafts and recipient left anterior descending coronary arteries was evaluated with combined two-dimensional and Doppler echocardiography in 15 patients with an internal mammary artery graft and in 24 patients with a saphenous vein graft. Comparative studies of coronary hemodynamics were also performed regarding these two different grafting techniques.The graft vessel was detected in 11 (79%) of 14 patients with an internal mammary artery graft and in 20 (87%) of 23 with a saphenous vein graft. The recipient left anterior descending coronary artery was detected in 10 (67%) of the former group and 17 (71%) of the latter. The blood flow patterns obtained were generally biphasic, consisting of systolic and diastolic phases with higher velocity during diastole. The maximal diastolic flow velocity in internal mammary artery grafts was much higher than that in saphenous vein grafts. In patients with an internal mammary artery graft, the flow pattern characteristics within the recipient coronary artery were quite similar to those within the arterial graft, and flow velocities within the recipient coronary artery and the arterial graft were quantitatively almost identical. This outcome may contribute to the long-term patency seen in internal mammary artery grafts.On the other hand, the flow velocity in saphenous vein grafts was fairly low throughout the cardiac cycle. Flow velocity in the recipient coronary artery in patients with a saphenous vein graft was accelerated only in early diastole. As a result, the recipient coronary artery flow pattern and velocity differed substantially from those in the saphenous vein graft. Internal mammary artery and saphenous vein grafts showed average diastolic peak flow velocity of 57.7 ± 9.9 and 28.0 ± 8.9 cm/s, respectively, compared with 55.1 ± 7.2 and 93.5 ± 14.7 cm/s, respectively, in the recipient coronary arteries with artery grafts and vein grafts.Thus, the Doppler method allowed us to evaluate not only the direct effects of bypass grafting on the coronary circulation, but also the differences in effects between these two different grafting techniques
Distribution of Lenticular Astigmatism in a Pre-Cataract Surgery Population
Recently custom ablation of LASIK (laserin situ keratomileusis) has rapidly evolved. It could achieve supervision temporarily, but we suspect that the vision could deteriorate due to against-the rule astigmatism decades after the operation.
To clarify this concern, we evaluated distribution of the total and corneal astigmatism of 101 eyes of 65 pre-cataract surgery patients (meanage:73 years). Then we calculated the lenticular astigrlatism by vector analysis. The mean amounts of total and corneal astigmatism were 1.22±1.50D and 0.97±0.84D each. The percentages of no astigmatism: oblique: with-the-rule: against-the-rule were
32: 4: 15: 50 and 7: 28: 26: 40, respectively. The mean amount of lenticular astigrlatism measured by vector analysis was 1.6± 1.4D. The percentage of no astigmatism: oblique: with-the-rule: against-the-rule was 2: 0: 39: 59. This biased distribution of astigmatism might have contributed to the biased distribution (no and against-the-rule) of total astigmatism. These data indicate that in a pre-cataract surgery population against-the-rule astigmatism is predominant in both corneal and lenticular astigmatism. We suspect that custom correction of adolescent eyes, in which with-the-rule astigmatism is predominant, might elicit more against-the-rule astigmatism when they reach pre-cataract surgery age population, leading to a decline in quality of vision
Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance
We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively,
were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using
SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas
(ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs
Mohawk promotes the maintenance and regeneration of the outer annulus fibrosus of intervertebral discs.
The main pathogenesis of intervertebral disc (IVD) herniation involves disruption of the annulus fibrosus (AF) caused by ageing or excessive mechanical stress and the resulting prolapse of the nucleus pulposus. Owing to the avascular nature of the IVD and lack of understanding the mechanisms that maintain the IVD, current therapies do not lead to tissue regeneration. Here we show that homeobox protein Mohawk (Mkx) is a key transcription factor that regulates AF development, maintenance and regeneration. Mkx is mainly expressed in the outer AF (OAF) of humans and mice. In Mkx(-/-) mice, the OAF displays a deficiency of multiple tendon/ligament-related genes, a smaller OAF collagen fibril diameter and a more rapid progression of IVD degeneration compared with the wild type. Mesenchymal stem cells overexpressing Mkx promote functional AF regeneration in a mouse AF defect model, with abundant collagen fibril formation. Our results indicate a therapeutic strategy for AF regeneration
Differing deregulation of HER2 in primary gastric cancer and synchronous related metastatic lymph nodes
Sorbtional properties of carbonic sorbents on the base of pine sawdust in the processes of purification of water mediums and complicated technological solution from petroleum products and phosphorus compounds are investigated. The possibility of carbonic sorbents modification by halogen organic compounds to increase the degree of purification of water ecosystems is analyzed. Исследованы сорбционные свойства углеродных сорбентов на основе опилок сосны в процессе очистки водных сред и сложных технологических растворов от нефтепродуктов и соединений фосфора. Рассмотрена возможность модифицирования углеродных сорбентов галогенсодержащих органическими соединениями с целью повыше-ния степени очистки водных экосистем. Досліджено сорбційні властивості вуглецевих сорбентів на основі обпилювань сосни у процесі очищення водних середовищ і складних технологічних розчинів від нафтопродуктів і з’єднань фосфору. Розглянуто можливість модифікування вуглецевих сорбентів галогеновмісними органічними з’єднаннями з метою підвищення ступеня очищення водних екосистем
Dynamic Trend of Myocardial Edema in Takotsubo Syndrome: A Serial Cardiac Magnetic Resonance Study
BACKGROUND
The wall motion abnormalities of the left ventricle (LV) in takotsubo syndrome (TTS) are known to be transient and completely recover within a few weeks. However, there is little information about the relationship between functional recovery and tissue characteristics. The aim of this study was to investigate the recovery process of TTS using cardiovascular magnetic resonance (CMR).
METHODS
Consecutive patients with TTS were prospectively enrolled. We performed serial CMR in the acute phase (<72 h after admission), the subacute phase (7-10 days after admission) and the chronic phase (3 months later). To assess the degree of myocardial edema quantitatively, we evaluated the signal intensity of myocardium on T2-weighted images and calculated the signal intensity ratio compared with the skeletal muscle.
RESULTS
Fifteen patients with TTS were enrolled. CMR demonstrated reduced LV ejection fraction in the acute phase, and it recovered almost completely by the subacute phase. On the other hand, severe myocardial edema was still observed in the subacute phase, associated with increased LV mass. The highest signal intensity ratio in the subacute phase was correlated with the maximum voltage of negative T wave on electrocardiogram (r = 0.57, p = 0.03).
CONCLUSIONS
In patients with TTS, myocardial edema associated with increased LV mass still remained in the subacute phase despite functional recovery of the LV. Electrocardiogram may be useful to assess the degree of myocardial edema in the subacute phase. Our study suggests that myocardial ischemia might have a central role in developing TTS
Lactisole: an inhibitor of the glucose-sensing receptor T1R3 expressed in pancreatic B-cells
Glucose activates the glucose-sensing receptor T1R3 and facilitates its own metabolism in pancreatic beta-cells. An inhibitor of this receptor would be helpful in elucidating the physiological function of the glucose-sensing receptor. The present study was conducted to examine whether or not lactisole can be used as an inhibitor of the glucose-sensing receptor. In MIN6 cells, in a dose-dependent manner, lactisole inhibited insulin secretion induced by sweeteners, acesulfame-K, sucralose and glycyrrhizin. The IC50 was similar to 4 mmol/l. Lactisole attenuated the elevation of cytoplasmic Ca2+ concentration ([Ca2+](c)) evoked by sucralose and acesulfame-K but did not affect the elevation of intracellular cAMP concentration ([cAMP](c)) induced by these sweeteners. Lactisole also inhibited the action of glucose in MIN6 cells. Thus, lactisole significantly reduced elevations of intracellular [NADH] and intracellular [ATP] induced by glucose, and also inhibited glucose-induced insulin secretion. To further examine the effect of lactisole on T1R3, we prepared HEK293 cells stably expressing mouse T1R3. In these cells, sucralose elevated both [Ca2+](c) and [cAMP](c). Lactisole attenuated the sucralose-induced increase in [Ca2+](c) but did not affect the elevation of [cAMP](c). Finally, lactisole inhibited insulin secretion induced by a high concentration of glucose in mouse islets. These results indicate that the mouse glucose-sensing receptor was inhibited by lactisole. Lactisole may be useful in assessing the role of the glucose-sensing receptor in mouse pancreatic beta-cells
A cancer stem cell model as the point of origin of cancer-associated fibroblasts in tumor microenvironment
Cancer-associated fibroblasts (CAFs) are one of the most prominent cell types in the stromal compartment of the tumor microenvironment. CAFs support multiple aspects of cancer progression, including tumor initiation, invasion, and metastasis. The heterogeneous nature of the stromal microenvironment is attributed to the multiple sources from which the cells in this compartment originate. The present study provides the first evidence that cancer stem cells (CSCs) are one of the key sources of CAFs in the tumor niche. We generated CSC-like cells by treating mouse induced pluripotent stem cells with conditioned medium from breast cancer cell lines. The resulting cell population expressed both CSC and pluripotency markers, and the sphere-forming CSC-like cells formed subcutaneous tumors in nude mice. Intriguingly, these CSC-like cells always formed heterogeneous populations surrounded by myofibroblast-like cells. Based on this observation, we hypothesized that CSCs could be the source of the CAFs that support tumor maintenance and survival. To address this hypothesis, we induced the differentiation of spheres and purified the myofibroblast-like cells. The resulting cells exhibited a CAF-like phenotype, suggesting that they had differentiated into the subpopulations of cells that support CSC self-renewal. These findings provide novel insights into the dynamic interplay between various microenvironmental factors and CAFs in the CSC niche
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