Angiotensin-(1–7) stimulates water transport in rat inner medullary collecting duct: evidence for involvement of vasopressin V2 receptors

The peptide angiotensin-(1–7) [Ang-(1–7)] is known to enhance water transport in rat inner medullary collecting duct (IMCD). The aim of this study was to determine the mechanism of the Ang-(1–7) effect on osmotic water permeability (P _f). P _f was measured in the normal rat IMCD perfused in vitro in presence of agonists [Ang-(1–7), arginine vasopressin (AVP) and Ang-(3–8)], and antagonists of the angiotensin and the vasopressin cascade. Ang-(1–7), but not Ang-(3–8), increased P _f significantly. The effect of Ang-(1–7) on P _f was abolished by its selective antagonist, A-779, added before or after Ang-(1–7). Prostaglandin E₂ and the protein kinase A inhibitor H8 also blocked the Ang-(1–7) effect. Blockade of vasopressin V₁ receptors by antagonists did not change the Ang-(1–7) effect, but pre-treatment with a V₂ antagonist abolished the effect of Ang-(1–7) on P _f. Similarly, pre-treatment with A-779 inhibited AVPs effect on P _f. Forskolin-stimulated P _f was blocked both by A-779 and by the V₂ antagonist. Finally, Ang-(1–7) increased cAMP levels in fresh IMCD cell suspensions whilst the forskolin-stimulated cAMP synthesis was decreased by A-779 and the V₂ antagonist. These data provide evidence that Ang-(1–7) interacts via its receptor with the AVP V₂ system through a mechanism involving adenylate-cyclase activation.     

The role of angiotensin-(1–7) receptor Mas in spermatogenesis in mice and rats

Evidence regarding the components of the renin–angiotensin (Ang) system suggests that this system plays an important role in male reproduction. However, there are few data available in the literature on the effects of Ang-(1–7) on the male reproductive system. The present study investigated the effects of the genetic deletion and chronic blockage of Ang-(1–7) receptor Mas on spermatogenesis and male fertility. The localization of Mas in mouse and rat testes was determined by binding assays and immunofluorescence, whereas the testis structure and spermatogenic process were morphologically and stereologically analysed by light microscopy. Ang-(1–7) binding and immunofluorescence revealed the presence of Mas in the testes of mice and rats. Although the total numbers of Sertoli and Leydig cells per testis and Leydig cell size were similar in both wild-type and Mas -deficient mice, Mas ^−/– animals exhibited a significant reduction in testis weight and a greater volume of apoptotic cells, giant cells and vacuoles in the seminiferous epithelium. In both mice and rats, an increased number of apoptotic cells were found during meiosis. Due to disturbed spermatogenesis, daily sperm production was markedly reduced in Mas ^−/– mice. Moreover, chronic infusion of A-779 [an Ang-(1–7) antagonist] in rats significantly increased the total number of apoptotic cells and primary spermatocytes in particular stages of spermatogenesis. Taken together, these findings strongly suggest that Ang-(1–7) receptor Mas plays an important role in the regulation of spermatogenesis.     

eIF5A-2在非小细胞肺癌上皮间质化过程中的作用机制

目的 探讨真核细胞翻译起始因子5A-2(eIF5A-2)的表达在非小细胞肺癌(NSCLC)上皮间质化(EMT)过程中的作用及其机制.方法 通过Westrn-blotting和免疫荧光检测细胞表型变化,利用siRNA转染下调eIF5A-2表达后再以Western-blotting和免疫荧光检测细胞表型的改变.用TGF-β1刺激诱导NSCLC细胞系NCI-H358和HCC827发生EMT后并利用Western-blotting检测eIF5A-2的表达.结果 NCI-H358和HCC827细胞系低表达eIF5A-2,为上皮表型,而NCI-H1299细胞高表达eIF5A-2,为间质表型.eIF5A-2 siRNA干扰后可以改变NCI-H1299细胞的间质表型.NCI-H358和HCC827细胞经TGF-β1诱导后可发生EMT变化,而eIF5A-2 siRNA干扰后则可防止这种变化的发生.结论 在不同的NSCLC细胞系中,间质表型细胞较上皮表型者高表达eIF5A-2.TGF-β1可诱导上皮表型细胞发生EMT,而干扰eIF5A-2则可阻止EMT的发生.     

Conversion of one-anastomosis gastric bypass to Roux-en-Y gastric bypass: short-term results from a tertiary referral center

BackgroundOne-anastomosis gastric bypass (OAGB), also known as minigastric bypass, is an increasingly popular bariatric surgery option worldwide. While OAGB offers advantage in terms of procedure time and technical ease, revisional operations to correct complications may be necessary.ObjectivesWe aimed to describe the indications and perioperative outcomes for OAGB conversions to Roux-en-Y gastric bypass (RYGB) at a single-referral center.SettingAcademic hospital, Abu Dhabi, United Arab Emirates.MethodsAll patients undergoing conversion from OAGB to RYGB from February 2016 through September 2018 were retrospectively identified from a prospectively maintained database of revisional bariatric surgeries.ResultsSixteen patients underwent conversion from previous OAGB to RYGB during the study period. The cohort was 62.5% female (n = 10) with a mean age of 40.2 years and median body mass index of 30.7 kg/m². Indications for conversion included intractable nausea/vomiting (n = 8, 50.0%), biliary reflux (n = 3, 18.8%), weight recidivism (n = 3, 18.8%), and protein-calorie malnutrition (n = 2, 12.5%). Twelve cases (75.0%) were successfully completed with a laparoscopic approach, with 4 cases (25.0%) converted to open. The median length of stay was 5.5 days. Six patients (37.5%) experienced minor and major complications within 30 days of discharge. Fourteen patients (87.5%) were available for follow-up at 6 months, with 100% of these patients reporting resolution of their preoperative symptoms. There were no mortalities.ConclusionsData from this largest reported single-center experience demonstrates that conversion of OAGB to RYGB is safe and technically feasible. Further studies and longer-term follow-up are needed to definitively describe outcomes after this revisional bariatric surgery.     

Dynorphin A-(1–13) attenuates basal forebrain-lesion-induced amnesia in rats

The effects of dynorphin A-(1–13), an endogenous κ opioid agonist, on basal forebrain (BF)-lesion-induced amnesia in rats were investigated using step-through-type passive avoidance task. The BF was lesioned by injecting the cholinergic neurotoxin ibotenic acid (6 μg/side). The number of rats achieving the cut-off time (600 s) of step-through latency (STL) in BF-lesioned group significantly decreased as compared with that in sham-operated group. Dynorphin A-(1–13) (0.3 μg) significantly increased the number of rats achieving the cut-off time of STL in BF-lesioned rats. These results suggest that dynorphins play an improving role in the impairment of memory processes in BF-lesioned rats.     

Spatiotemporal distribution of glia in and around the developing mouse optic tract

In the developing mouse optic tract, retinal ganglion cell (RGC) axon position is organized by topography and laterality (i.e., eye-specific or ipsi- and contralateral segregation). Our lab previously showed that ipsilaterally projecting RGCs are segregated to the lateral aspect of the developing optic tract and found that ipsilateral axons self-fasciculate to a greater extent than contralaterally projecting RGC axons in vitro. However, the full complement of axon-intrinsic and -extrinsic factors mediating eye-specific segregation in the tract remain poorly understood. Glia, which are known to express several guidance cues in the visual system and regulate the navigation of ipsilateral and contralateral RGC axons at the optic chiasm, are natural candidates for contributing to eye-specific pre-target axon organization. Here, we investigate the spatiotemporal expression patterns of both putative astrocytes (Aldh1l1+ cells) and microglia (Iba1+ cells) in the embryonic and neonatal optic tract. We quantified the localization of ipsilateral RGC axons to the lateral two-thirds of the optic tract and analyzed glia position and distribution relative to eye-specific axon organization. While our results indicate that glial segregation patterns do not strictly align with eye-specific RGC axon segregation in the tract, we identify distinct spatiotemporal organization of both Aldh1l1+ cells and microglia in and around the developing optic tract. These findings inform future research into molecular mechanisms of glial involvement in RGC axon growth and organization in the developing retinogeniculate pathway.     

UPLC同时测定清热止咳颗粒中7种黄酮类成分含量

目的 建立同时测定清热止咳颗粒中芸香柚皮苷、柚皮苷、橙皮苷、新橙皮苷、黄芩苷、木蝴蝶素A-7-葡萄糖醛酸苷、汉黄芩苷含量的方法。方法 采用超高效液相色谱法。采用ACQUITY UPLC BEH C₁₈色谱柱（2.1 mm×100 mm,1.7 μm）,流动相乙腈-0.1%甲酸水溶液(梯度洗脱) ,流速0.3 mL·min^-1,检测波长280 nm,柱温30 ℃。结果 芸香柚皮苷、柚皮苷、橙皮苷、新橙皮苷、黄芩苷、木蝴蝶素A-7-葡萄糖醛酸苷、汉黄芩苷分别在0.324～6.480（r=0.999 9）,1.337～26.75（r=0.999 7）,0.687～13.80（r=0.999 6）,1.347～26.95（r=0.999 8）,2.770～55.40（r=0.999 2）,0.330～6.600（r=0.999 8）,0.242～4.840（r=0.999 6）μg·mL^-1范围内与峰面积呈良好的线性关系;并且芸香柚皮苷、柚皮苷、橙皮苷、新橙皮苷、黄芩苷、木蝴蝶素A-7-葡萄糖醛酸苷、汉黄芩苷平均加样回收率分别为99.41%、101.80%、99.42%、98.47%、101.71%,102.27%和97.64%,RSD范围分别是2.32%、1.69%、2.38%、2.45%、1.24%、1.77%和1.91%。结论 建立的超高效液相色谱(UPLC)方法操作简便、稳定、准确且可行,可用于清热止咳颗粒的质量控制。     

房室结折返性心动过速慢径消融的两种有效消融指标疗效比较

目的：评价以出现交界性心律与心房起搏显示慢径前传导阻滞作为有效消融指标在房室结折返性心动速（AVNRT）慢径消融中应用,比较这两种有效消融指标判断方法在慢径消融达到消融终点时的放电时间与消融靶点数的差异性。方法：153例AVNRT病人接受慢径射频消融术,根据X影像部位和局部电图特点确定消融靶点,放电功率10～40 W。按不同的有效消融判断指标分为传统方法消融（出现交界性心律）组（I组）和以心房起搏显示慢径前传导阻滞作为有效消融指标消融组（II组）。I组86例在放电后15 s内以出现交界心律或早搏后继续放电60～90 s;II组67例放电15 s内出现交界心律或早搏后延迟放电至20 s停止放电,以术前AV1：1最短间期心房刺激（S1S1）显示慢径前传阻滞后停止起搏继续放电至60 s。未达到消融终点者再继续选点消融,直至达到消融终点。结果：两组病人均达到消融终点,消融终点及终点类型两组间无差异性。I组86例,共有效消融靶点306个。人均消融（3.59±1.21）个靶点,放电时间（208.94±89.76）s;II组67例,共有效消融靶点150个,人均消融靶点（2.24±0.94）个,放电时间（114.83±38.97）s。人均各项参数Ⅰ组高于Ⅱ组,两组间比较存在显著差异（P（0.05）。15 s内无效消融不计靶点数。结论：显示慢径前传导阻滞作为有效消融指标可客观判放电消融的有效性,减少无效消融的心肌损伤。     

Effect of calcium therapy in the sick premature infant with early neonatal hypocalcemia

Twenty-seven sick premature infants with serum calcium concentrations less than 6.0 mg/dl during the first day of age were enrolled in a prospective controlled study involving two treatment regimens--calcium given as a bolus or a drip--or no treatment. Mean total calcium concentration was 5.5 +/- 0.8 mg/dl, and ionized calcium was 3.1 +/- .3 mg/dl, with no significant difference between treatment groups. By 24 hours, in all groups total calcium had increased to greater than 6.0 mg/dl (bolus 6.5 +/- 1.1, drip 7.0 +/- 0.4, control 6.6 +/- 0.4) and ionized calcium to greater than 3.5 mg/dl (bolus 3.9 +/- 0.3, drip 3.6 +/- 0.6, control 3.6 +/- 0.3). Ionized and total calcium concentrations were significantly correlated (r = 0.562; P less than 0.001), but total calcium did not predict ionized calcium in any group. These data support the concept that, even in sick infants, early neonatal hypocalcemia is a physiologic phenomenon that may not require treatment.