Temporary Suppression of the Hyperglycemic Response to 2-Deoxy-d-Glucose by Blinding

Studies were made on whether there is a time-dependency in the hyperglycemic response to intracranial injection of 2-deoxy-d-glucose (2DG) in blind rats. 2DG was given to blind rats in their subjective light and dark periods to see if the response free-runs like their circadian locomotor and feeding rhythms. The following results were obtained: (1) In control period and week 3 after blinding, 2DG caused greater hyperglycemia in the subjective light period than in the subjective dark period; (2) In weeks 4 and 6, however, 2DG caused only slight hyperglycemia, while it caused considerable hyperinsulinemia in both the subjective light and dark periods with no time-dependency. (3) In week 8, the hyperglycemic response to 2DG was completely restored while the hyperinsulinemic response was lost. These findings indicate that the subjective time-dependency in the hyperglycemic response to intracranial injection of 2DG exists until week 3 and after week 8 after blinding, however, in week 4 and 6 after blinding the subjective time-dependency appeared to disappear and the hyperglycemic response is largely suppressed in association with hyperinsulinemia. Together with a previous finding that bilateral lesions of the SCN completely abolished the response to 2DG and the fact that blind rats showed circadian rhythms of feeding and locomotive activity even in weeks 4 and 6 after blinding, these findings present the possibility that the site responding to 2DG is in the vicinity of the SCN, but is indifferent neuronal cells from those of the circadian oscillator. However, it is also possible that the blinding elicits the suppression of hyperglycemia due to 2DG through disturbing neural pathway outside the SCN which control blood glucose concentration.     

彩色超声与盲探穿刺右颈内静脉并发症比较

目的比较彩色超声引导与盲探穿刺右侧颈内静脉置管术的并发症情况。方法将我院拟择期(在腹腔镜下)行结直肠肿瘤切除术的患者100例,ASA分级Ⅰ~Ⅲ级,年龄23~81岁,体重32~81kg。采用抛硬币法将患者随机分为彩色超声组(C)和盲探穿刺组(M)各50例。记录两组病人黑色细针试穿中静脉时次数、薄壁蓝空针穿刺中静脉时次数、穿刺点的数目、导管置入失败的次数,并记录病人由于穿刺引起的机械并发症及术后留置导管并发症情况。结果两组患者均未见明显机械并发症,且两组比较无统计学意义;两组无误穿动脉、血气胸及心律失常或心脏损伤的情况。结论彩色超声引导下行右颈内静脉穿刺成功率较盲探穿刺高,盲探穿刺刺破颈内静脉后壁概率较彩色多普勒超声引导下穿刺组高,其余机械并发症及留置中心静脉导管并发症比较无统计学意义。     

Promotion of Citrate Transport of the Transport-negative Mutants of Aerobacter cloacae

The “citrate transport-enhancing factor” obtained from Aerobacter cloacae did stimulate uptake of radioactive citrate by Escherichia coli, having an intrinsic barrier against citrate permeation. In order to prove function of the factor in the cells of Aerobacter, citrate transport-negative mutants of A. cloacae were isolated. These mutants were found to be lacking in the factor. Addition of the factor to these mutants resulted in stimulation of uptake of citrate. These results evidenced that the factor played an essential role in the citrate transport system of A. cloacae.     

A genetic tool kit for cellular and behavioral analyses of insect sugar receptors

Arthropods employ a large family of up to 100 putative taste or gustatory receptors (Grs) for the recognition of a wide range of non-volatile chemicals. In Drosophila melanogaster, a small subfamily of 8 Gr genes is thought to mediate the detection of sugars, the fly''s major nutritional source. However, the specific roles for most sugar Gr genes are not known. Here, we report the generation of a series of mutant sugar Gr knock-in alleles and several composite sugar Gr mutant strains, including a sugar blind strain, which will facilitate the characterization of this gene family. Using Ca²⁺ imaging experiments, we show that most gustatory receptor neurons (GRNs) of sugar blind flies (lacking all 8 sugar Gr genes) fail to respond to any sugar tested. Moreover, expression of single sugar Gr genes in most sweet GRNs of sugar-blind flies does not restore sugar responses. However, when pair-wise combinations of sugar Gr genes are introduced to sweet GRNs, responses to select sugars are restored. We also examined the cellular phenotype of flies homozygous mutant for Gr64a, a Gr gene previously reported to be a major contributor for the detection of many sugars. In contrast to these claims, we find that sweet GRNs of Gr64a homozygous mutant flies show normal responses to most sugars, and only modestly reduced responses to maltose and maltotriose. Thus, the precisely engineered genetic mutations of single Gr genes and construction of a sugar-blind strain provide powerful analytical tools for examining the roles of Drosophila and other insect sugar Gr genes in sweet taste.     

White‐headed Vulture Trigonoceps occipitalis shows visual field characteristics of hunting raptors

The visual fields of the Aegypiinae vultures have been shown to be adapted primarily to meet two key perceptual challenges of their obligate carrion‐feeding behaviour: scanning the ground and preventing the sun's image falling upon the retina. However, field observations have shown that foraging White‐headed Vultures Trigonoceps occipitalis are not exclusively carrion‐feeders; they are also facultative predators of live prey. Such feeding is likely to present perceptual challenges that are additional to those posed by carrion‐feeding. Binocularity is the key component of all visual fields and in birds it is thought to function primarily in the accurate placement and time of contact of the talons and bill, especially in the location and seizure of food items. We determined visual fields in White‐headed Vultures and compared them with those of two species of carrion‐eating Gyps vultures. The visual field of White‐headed Vultures has more similarities with those of predatory raptors (e.g. accipitrid hawks) than with the taxonomically more closely related Gyps vultures. Maximum binocular field width in White‐headed Vultures (30°) is significantly wider than that in Gyps vultures (20°). The broader binocular fields in White‐headed Vultures probably facilitate accurate placement and timing of the talons when capturing evasive live prey.     

Locomotory Responses of the Cave Cyprinid Phreatichthys Andruzzii Chemical Signals from Conspecifics and Related Species: New Findings

Previous research on chemical communication among hypogean fishes have suggested that these species are attracted, as are epigean species, by the odour of non-injured conspecifics. Considerations on the biological meaning of such responses and some doubts about the reliability of the experimental procedure previously utilised, have led us to reconsider the matter and verify the results already obtained in the cave cyprinid Phreatichthys andruzzii. Using a new methodological approach we ascertained not only the absence of positive chemotaxis to odour of known or unknown conspecifics, but also the presence of a strong negative chemotaxis towards the odour of unfamiliar conspecifics and of individuals belonging to the closely related species Barbus conchonius. The biological meaning and the adaptive value of these reactions are briefly discussed.     

降纤酶双盲对照治疗急性脑梗死109例

目的　评价降纤酶治疗急性脑梗死的临床疗效及与中药川芎嗪的比较。　方法　采用前瞻性、随机、双盲对照的方法。选择 2 4 h内的患者。降纤酶第 1天 1 0 u,第 3、 5天各 5 u静滴。　结果　降纤酶组急性期治愈率高于对照组 ,有显著差异 ;1 2周治愈率接近。神经功能缺损评分及 Barthel指数略好于对照组 ,但无显著差异。降纤酶组治疗后纤维蛋白原明显降低 ,与治疗前及对照组比较 ,有非常显著差异。结论　降纤酶有显著降低血纤维蛋白原作用 ,对 2 4 h内急性脑梗死疗效较川芎嗪略好。无明显毒副作用。     

Evaluation and recommendations for greater accessibility of colour figures in ornithology

People who are colour‐blind or have some form of colour vision deficiency form an invisible minority and scientists should strive to be as inclusive as possible. We reviewed 2873 figures published in 2019 from 1031 scientific papers in 27 ornithological journals to determine those that were colour‐blind compatible, and those that were black‐and‐white printer friendly. About 26% of the published figures were in colour, and while most were colour‐blind compatible, only ~ 60% of them were black‐and‐white printer friendly. Ensuring figures in all forms of scientific communication can be interpreted by readers who are colour‐blind, and can be printed in black‐and‐white will improve the accessibility of ornithological research.