益气活血中药复方对CVB3大鼠心肌细胞感染模型ATP6基因表达的影响

目的：研究益气活血中药复方对CVB3大鼠心肌细胞感染模型ATP6（ATP synthase F0 subunit 6）基因表达的作用机制。方法：本实验用新生2-3dWistar大鼠心肌细胞,建立CVB,病毒感染模型,通过改良的抑制性消减杂交技术（SSH）,克隆了受CVB,攻击的心肌细胞中被中药（益气活血中药复方）调控的基因。结果：ATP6基因,在中药组中高表达,而病毒组中表达减弱或抑制。结论：益气活血中药复方能影响受CVB,病毒攻击的宿主细胞ATP6基因的表达,有效保护心肌、阻断病程进度,从而实现治疗病毒性心肌炎的目的。     

循环血中microRNAs作为疾病标志物的研究进展

新近研究发现成熟的microRNA能够游离于细胞之外,稳定存在于循环血中,具备疾病分子生物标志物的某些优点,已在多种肿瘤和非肿瘤疾病的早期诊断和预后中显示了独特的价值,同时循环血中microRNA的功能研究也已开始。该文针对近两年循环血中microRNA标志物及功能研究的成果,对microRNA研究中的这一热点问题进行综述。     

Projecting the distribution of forests in New England in response to climate change

Aim To project the distribution of three major forest types in the northeastern USA in response to expected climate change. Location The New England region of the United States. Methods We modelled the potential distribution of boreal conifer, northern deciduous hardwood and mixed oak–hickory forests using the process‐based BIOME4 vegetation model parameterized for regional forests under historic and projected future climate conditions. Projections of future climate were derived from three general circulation models forced by three global warming scenarios that span the range of likely anthropogenic greenhouse gas emissions. Results Annual temperature in New England is projected to increase by 2.2–3.3 °C by 2041–70 and by 3.0–5.2 °C by 2071–99 with corresponding increases in precipitation of 4.7–9.5% and 6.4–11.4%, respectively. We project that regional warming will result in the loss of 71–100% of boreal conifer forest in New England by the late 21st century. The range of mixed oak–hickory forests will shift northward by 1.0–2.1 latitudinal degrees (c. 100–200 km) and will increase in area by 149–431% by the end of the 21st century. Northern deciduous hardwoods are expected to decrease in area by 26% and move upslope by 76 m on average. The upslope movement of the northern deciduous hardwoods and the increase in oak–hickory forests coincide with an approximate 556 m upslope retreat of the boreal conifer forest by 2071–99. In our simulations, rising atmospheric CO₂ concentrations reduce the losses of boreal conifer forest in New England from expected losses based on climatic change alone. Main conclusion Projected climate warming in the 21st century is likely to cause the extensive loss of boreal conifer forests, reduce the extent of northern hardwood deciduous forests, and result in large increases of mixed oak–hickory forest in New England.     

Cranial circulation of the pen-tailed tree shrewPtilocercus lowii and relationships of Scandentia

The major cranial arteries and veins are described for a 30-mm crown-rump length fetus of the pen-tailed tree shrewPtilocercus lowii, and comparisons are made with cranial vessels reported in the tree shrewTupaia and with the vascular pattern reconstructed for primitive eutherians.Ptilocercus shares a number of derived features of the cranial circulation withTupaia, which, therefore, represent synapomorphies of tree shrews (Tupaiidae, Scandentia). Included are (1) the enclosure of the intratympanic portion of the internal carotid artery in a bony canal that is floored proximally and distally by the entotympanic and by the petrosal in between, (2) the enclosure of the intratympanic portion of the stapedial artery by the petrosal in a canal on the promontorium and within the epitympanic crest beneath the tympanic roof, (3) the absence of an exit for the arteria diploëtica magna, (4) an alisphenoid canal, (5) a maxillary artery that passes medial to the mandibular nerve beneath foramen ovale, and (6) a laryngeopharyngeal artery. Some of these derived features, however, are also found in certain other eutherians (e.g., numbers 2, 3, and 6 in Euprimates) and, therefore, may be used in future studies to assess the higher-level affinities of Scandentia.     

Treatment with the mitochondrial‐targeted antioxidant peptide SS‐31 rescues neurovascular coupling responses and cerebrovascular endothelial function and improves cognition in aged mice

Moment‐to‐moment adjustment of cerebral blood flow (CBF) via neurovascular coupling has an essential role in maintenance of healthy cognitive function. In advanced age, increased oxidative stress and cerebromicrovascular endothelial dysfunction impair neurovascular coupling, likely contributing to age‐related decline of higher cortical functions. There is increasing evidence showing that mitochondrial oxidative stress plays a critical role in a range of age‐related cellular impairments, but its role in neurovascular uncoupling remains unexplored. This study was designed to test the hypothesis that attenuation of mitochondrial oxidative stress may exert beneficial effects on neurovascular coupling responses in aging. To test this hypothesis, 24‐month‐old C57BL/6 mice were treated with a cell‐permeable, mitochondria‐targeted antioxidant peptide (SS‐31; 10 mg kg^?1 day^?1, i.p.) or vehicle for 2 weeks. Neurovascular coupling was assessed by measuring CBF responses (laser speckle contrast imaging) evoked by contralateral whisker stimulation. We found that neurovascular coupling responses were significantly impaired in aged mice. Treatment with SS–31 significantly improved neurovascular coupling responses by increasing NO‐mediated cerebromicrovascular dilation, which was associated with significantly improved spatial working memory, motor skill learning, and gait coordination. These findings are paralleled by the protective effects of SS–31 on mitochondrial production of reactive oxygen species and mitochondrial respiration in cultured cerebromicrovascular endothelial cells derived from aged animals. Thus, mitochondrial oxidative stress contributes to age‐related cerebromicrovascular dysfunction, exacerbating cognitive decline. We propose that mitochondria‐targeted antioxidants may be considered for pharmacological microvascular protection for the prevention/treatment of age‐related vascular cognitive impairment (VCI).     

Role of blood flow on RF exposure induced skin temperature elevations in rabbit ears

In this in vivo study, we measured local temperature changes in rabbit pinnae, which were evoked by radiofrequency (RF) exposure for 20 min at localized SAR levels of 0 (sham exposure), 2.3, 10.0, and 34.3 W/kg over 1.0 g rabbit ear tissue. The effects of RF exposures on skin temperature were measured under normal blood flow and without blood flow in the ear. The results showed: (1) physiological blood flow clearly modified RF induced thermal elevation in the pinna as blood flow significantly suppressed temperature increases even at 34.3 W/kg; (2) under normal blood flow conditions, exposures at 2.3 and 10.0 W/kg, approximating existing safety limits for the general public (2 W/kg) and occupational exposure (10 W/kg), did not induce significant temperature rises in the rabbit ear. However, 2.3 W/kg induced local skin temperature elevation under no blood flow conditions. Our results demonstrate that the physiological effects of blood flow should be considered when extrapolating modeling data to living animals, and particular caution is needed when interpreting the results of modeling studies that do not include blood flow.     

Reappraisal of patterns of nonmarine cryptodiran turtle carotid circulation: evidence from osteological correlates and soft tissues

The turtle cranial circulation has been employed as an important source of phylogenetic information, but recent conflicting hypotheses of relationship within Testudinata suggest reevaluation of the utility of characters drawn from this complex. As a component of a comprehensive character analysis, the osteological correlates of the nonmarine cryptodiran turtle carotid circulation are herein subjected to high-resolution X-ray computed tomography, reassessed, and statistically investigated. Three different patterns of osteological correlates, indicating three disparate cranial circulatory patterns, are described, and this finding is corroborated by evidence from circulatory soft tissues. Members of the Trionychia and Kinosternoidea exhibit patterns that differ from the more widespread condition found in testudinoid taxa. This result differs from previous work, which has indicated the presence of only two major cranial circulatory patterns, and suggests that while cranial circulatory features may be phylogenetically informative, the information contained within them indicates patterns of relationship different from those previously hypothesized.     

Placement Of A Coronary Sinus Pacing Lead From A Sub-occluded Left Subclavian Vein Using A Collateral Vein To The Right Subclavian Vein

Upgrading of a pacing system in the presence of a subclavian occlusion is technically challenging. We describe the case of a patient who underwent a successful upgrading procedure of an implantable cardioverter-defibrillator (ICD) to a biventricular defibrillator (ICD-CRT) in the presence of a suboccluded left subclavian vein, using a collateral vein that drained into the contralateral subclavian vein.     

Occurrence of Rotifera in the field user natural and intentionally-changed conditions. II. Lake Numasawa

Seasonal and vertical occurrences of representative rotifer species were recorded together with such taxa as Cyanophycea, Phytomastigophorea, Bacillariophycea, Protozoa, Rotifera and Crustacea, from 1982 to 1986 at two sites S1 (natural) and S2 (nearby water circulated since 1952). 1) The following species were observed from S1: K. hiemalis, C. ovalis, N. labis, L. patella and Anuraeopsis sp., from S2: B. urceolaris and A. ecaudis, 2) P. hudsoni appeared in 1984 as a successor to P. truncatum, 3) K. longispina was negatively associated with P. t. vulgaris, 4) Synchaeta spp suddenly appeared at both sites in 1985, 5) K. cochlearis, B. calyciflorus, Proalides sp., Diurella sp., N. labis, B. urceolaris and bdelloids did not appear until 1986, 6) The following species decreased or disappeared: A. p. herricki and Collotheca sp. since 1982, C. coenobasis, C. hippocrepis and K. hiemalis since 1984, 7) A complicated relation was observed between rotifer population density and other plankton. 8) Occurrence of Rotifera seemed to be affected by circulation of an electric power plant.