正常人肾动脉内径和血流参数的超声测量

本文报告用二维超声和多普勒超声测量３０６只正常肾的肾动脉内径和肾动脉、弓形动脉的血流参数。结果表明；正常成人肾动脉、弓形动脉的收缩期峰速、舒张末期流速、脉动指数和阻力指数与性别、年龄、左右侧肾无相关，而随体表面积的增大，肾动脉内径增大；随年龄的增长，肾动脉内径有所增宽，但后者变化无统计学意义。     

Direct and Indirect Effects of Cannabinoids on in vitro GABA Release in the Rat Arcuate Nucleus

Within the hypothalamic arcuate nucleus, two neuronal subpopulations play particularly important roles in energy balance; neurones expressing neuropeptide Y (NPY), agouti‐related peptide (AgRP) and GABA are orexigenic, whereas neurones expressing pro‐opiomelanocortin and CART are anorexigenic. The pivotal role of these neuropeptides in energy homeostasis is well‐known, although GABA may also be an important signal because targeted knockout of the GABA transporter in NPY/AgRP/GABA neurones results in a lean, obesity‐resistant phenotype. In the present study, we describe an in vitro model of K⁺‐evoked GABA release from the hypothalamus and determine the effects of cannabinoid receptor activation. K⁺‐evoked GABA release was sensitive to leptin, insulin and PYY(3‐36), indicating that GABA was released by arcuate NPY/AgRP/GABA neurones. In the presence of tetrodotoxin (TTX), the cannabinoid CB1 receptor agonist WIN 55,212‐2 inhibited K⁺‐evoked GABA release. This was prevented by the CB1 receptor inverse agonist rimonabant. Rimonabant had no effect when applied alone. In the absence of TTX, however, the opposite effects were observed: WIN 55,212‐2 had no effect while rimonabant inhibited GABA release. This indicates that GABA release can involve an indirect, TTX‐sensitive mechanism. The most parsimonious explanation for the inhibition of GABA release by a CB receptor inverse agonist is via the disinhibition of an cannabinoid‐sensitive inhibitory input onto GABAergic neurones. One local source of an inhibitory neurotransmitter is the opioidergic arcuate neurones. In our in vitro model, K⁺‐evoked GABA release was inhibited by the endogenous opioid peptide β‐endorphin in a naloxone‐sensitive manner. The inhibitory effect of rimonabant was also prevented by naloxone and a κ‐opioid receptor selective antagonist, suggesting that GABA release from arcuate NPY/AgRP/GABA neurones can be inhibited by endogenous opioid peptides, and that the release of opioid peptides is sensitive to cannabinoids.     

The different time courses of reading different levels of Chinese characters: an ERP study

AMP-activated protein kinase (AMPK) is an energy sensor that is activated by the increase of intracellular AMP:ATP ratio. AMPK in the hypothalamic arcuate nucleus (ARC) is activated during fasting and the activation of AMPK stimulates food intake. To clarify the pathway underlying AMPK-induced feeding, we monitored the activity of single ARC neurons by measuring cytosolic Ca(2+) concentration ([Ca(2+)](i)) with fura-2 fluorescence imaging. An AMPK activator, AICA-riboside (AICAR), at 200 μM increased [Ca(2+)](i) in 24% of ARC neurons. AMPK and acetyl CoA carboxylase were phosphorylated in the neurons with [Ca(2+)](i) responses to AICAR. AICAR-induced [Ca(2+)](i) increases were inhibited by Ca(2+)-free condition but not by thapsigargin, suggesting that AICAR increases [Ca(2+)](i) through Ca(2+) influx from extracellular space. Among AICAR-responding ARC neurons, 38% were neuropeptide Y (NPY)-immunoreactive neurons while no proopiomelanocortin (POMC)-immunoreactive neuron was observed. Intracerebroventricular administration of AICAR increased food intake, and the AICAR-induced food intake was abolished by the co-administration of NPY Y1 receptor antagonist, 1229U91. These results indicate that the activation of AMPK leads to the activation of ARC NPY neurons through Ca(2+) influx, thereby causing NPY-dependent food intake. These mechanisms could be implicated in the stimulation of food intake by physiological orexigenic substances.     

A sensitive period for environmental regulation of eating behavior and leptin sensitivity

Western lifestyle contributes to body weight dysregulation. Leptin down-regulates food intake by modulating the activity of neural circuits in the hypothalamic arcuate nucleus (ARC), and resistance to this hormone constitutes a permissive condition for obesity. Physical exercise modulates leptin sensitivity in diet-induced obese rats. The role of other lifestyle components in modulating leptin sensitivity remains elusive. Environmentally enriched mice were used to explore the effects of lifestyle change on leptin production/action and other metabolic parameters. We analyzed adult mice exposed to environmental enrichment (EE), which showed decreased leptin, reduced adipose mass, and increased food intake. We also analyzed 50-d-old mice exposed to either EE (YEE) or physical exercise (YW) since birth, both of which showed decreased leptin. YEE mice showed no change in food intake, increased response to leptin administration, increased activation of STAT3 in the ARC. The YW leptin-induced food intake response was intermediate between young mice kept in standard conditions and YEE. YEE exhibited increased and decreased ratios of excitatory/inhibitory synapses onto α-melanocyte-stimulating hormone and agouti-related peptide neurons of the ARC, respectively. We also analyzed animals as described for YEE and then placed in standard cages for 1 mo. They showed no altered leptin production/action but demonstrated changes in excitatory/inhibitory synaptic contacts in the ARC similar to YEE. EE and physical activity resulted in improved insulin sensitivity. In conclusion, EE and physical activity had an impact on feeding behavior, leptin production/action, and insulin sensitivity, and EE affected ARC circuitry. The leptin-hypothalamic axis is maximally enhanced if environmental stimulation is applied during development.     

C75 is converted to C75-CoA in the hypothalamus, where it inhibits carnitine palmitoyltransferase 1 and decreases food intake and body weight

Central nervous system administration of C75 produces hypophagia and weight loss in rodents identifying C75 as a potential drug against obesity and type 2 diabetes. However, the mechanism underlying this effect is unknown. Here we show that C75-CoA is generated chemically, in vitro and in vivo from C75 and that it is a potent inhibitor of carnitine palmitoyltranferase 1 (CPT1), the rate-limiting step of fatty-acid oxidation. Three-D docking and kinetic analysis support the inhibitory effect of C75-CoA on CPT1. Central nervous system administration of C75 in rats led to C75-CoA production, inhibition of CPT1 and lower body weight and food intake. Our results suggest that inhibition of CPT1, and thus increased availability of fatty acids in the hypothalamus, contribute to the pharmacological mechanism of C75 to decrease food intake.     

Seconds from disaster: lessons learned from laparoscopic release of the median arcuate ligament

Median arcuate ligament syndrome (MALS) is a rare entity that manifests as abdominal pain, nausea, vomiting, and diarrhea. The median arcuate ligament is a fibrous band that connects the crura of the diaphragm. In some people, the ligament is positioned in a way that compresses the celiac axis, which in a subset of individuals causes the symptoms associated with MALS. Surgical release of the ligament can relieve these symptoms. After viewing a video that described the laparoscopic median arcuate ligament release technique at the 2006 SAGES meeting and reviewing the online video, we report our experience with two cases and discuss the lessons learned in performing the procedure within a training program. We also discuss the extent to which surgical resident participation contributes to intraoperative complications during a new and complex surgery. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Morphologic evidence for intranuclear circuits in the hypothalamic arcuate nucleus

Three weeks after complete deafferentation of the medial basal hypothalamus (MBH) of adult female rats, the hypothalamic arcuate nucleus (ARCN) was examined ultrastructurally. Axodendritic and axosomatic synapses were counted in a field of 18,000 μm² in the middle part of the ARCN in each brain. Intraventricular infusion of 5-hydroxydopamine before autopsy resulted in the differentiation of two types of axon terminals. One axon terminal contained small spherical vesicles (SSVs, about 50 nm in diameter) and the other contained 5-hydroxydopamine-labeled small granular vesicles (SGVs) which were regarded as monoaminergic terminals. In the completely deafferented MBH, mean numbers of SSV and SGV synapses of the ARCN decreased to about one-half and one-fourth, respectively, compared to those of the unoperated rats. However, considerable numbers of intact SSV and SGV synapses were still encountered in the ARCN following deafferentation. There was no significant difference in the number of synapses between the large MBH island (including ARCN and ventromedial nucleus) and the small MBH island (mostly localized in ARCN). These results suggested that numerous converging nonmonoaminergic and monoaminergic fibers terminated in the ARCN and also suggested that nonmonoaminergic and monoaminergic arcuate neurons connected directly with other arcuate neurons.     

Pictorial essay of ultrasound‐reconstructed coronal plane images of the uterus in different uterine pathologies

Imaging in the major planes (horizontal, coronal, and sagittal) of the uterus is important for determining anatomy and allowing the findings to be standardized, and for evaluating and diagnosing different pathological conditions in clinical practice. Examination of the coronal plane is an important step in identifying uterine pathologies and their relationships to the endometrial canal. Three‐dimensional (3D) ultrasound reveals the normal anatomy better and improves the depiction of abnormal anatomy, as the coronal plane of the uterus can easily be obtained using 3D reconstruction techniques. Our pictorial essay demonstrates that adding 3D ultrasound to a routine gynecological workup can be beneficial for clinicians, enabling a precise diagnosis to be made. In addition, the volumes obtained and stored by 3D ultrasound can allow students or residents to become more familiar with normal and abnormal pelvic structures. Clin. Anat. 31:373–379, 2018. © 2017 Wiley Periodicals, Inc.     

Neural connections of hypothalamic neuroendocrine nuclei in the rat

The secretion of many hormones, including oxytocin, vasopressin and growth hormone, is not constant but shows a day-night rhythm. The suprachiasmatic nucleus (SCN) is thought to generate most mammalian biological rhythms and previous studies have reported suprachiasmatic efferents to the paraventricular nucleus (PVN) and the supraoptic nucleus (SON). We used in vivo extracellular electrophysiological techniques to show that the SCN also sends direct and indirect neural projections to the arcuate nucleus (ARC). This projection consisted of both excitatory and inhibitory components and may contribute to the entrainment of the rhythm in growth hormone secretion to the day-night cycle. Some SCN neurones appear to project to both the SON and the ARC. The SCN in turn receives excitatory and inhibitory inputs from the ARC and the peri-nuclear zone of the SON (peri-SON), which may provide feedback information, as well as allowing nonphotic entrainment of the SCN, for example, in response to feeding. Our data thus suggest extensive two-way connections between the SCN and its target nuclei which may contribute to the generation of day-night neuroendocrine rhythms. They also suggest the existence of indirect retinal projections to the ARC and PVN. We further investigated the retinal projection to the SCN. We were unable to demonstrate a significant difference in retinal input to those suprachiasmatic cells which had efferent projections to particular hypothalamic targets (SON and/or ARC), and those which did not.