Dorsal-ventral signaling in limb development

In both Drosophila wings and vertebrate limbs, signaling between dorsal and ventral cells establishes an organizer that promotes limb formation. Significant progress has been made recently towards characterizing the signaling interactions that occur at the dorsal—ventral limb border. Studies of chicks have indicated that, as in Drosophila, this signaling process requires the participation of Fringe. Studies of Drosophila have indicated that Fringe functions by inhibiting the ability of Notch to be activated by one ligand, Serrate, while potentiating the ability of Notch to be activated by another ligand, Delta. Recent studies of both Drosophila and vertebrates have also shed new light on the signaling activity of the dorsal—ventral boundary limb organizer, and have highlighted how this organizer is maintained by feedback mechanisms with neighboring cells.     

Supralinear and Supramodal Integration of Visual and Tactile Signals in Rats: Psychophysics and Neuronal Mechanisms

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正常小儿胫神经诱发脊髓电位特征和脑瘫小儿该电位的变化

采取刺激后胫神经(PTN)诱发叠加技术,利用体表无创伤性双极记录方法观察了16例正常小儿和43例脑瘫小儿的脊髓诱发电位(SCEP)。正常小儿的SCEP自下而上潜伏时逐渐延长、电压减小。从椎体C6到T10表现为Pa-Na-Pb三相波,T10～T12为Pa-Na1-Na2-Pb波,T12～L4为多相复合波。左右侧SCEP波形相似,潜伏时、电压相同,它们之间无统计学显著差别;但不同节段之间SCEP差异显著;脊髓传导速度为57.14m/s。脑瘫小儿SCEP正常者占14％;全髓反应低下者占20％;左右侧反应不对称者占46％;节段性反应低下者占15％;其它异常约占5％。不但节段间存在显著差异,而且全脊髓左右侧电压间以及颈、腰骶髓的潜伏时间出现显著差异。脊髓传导速度减低(患侧46.22m/s,对侧53.48m/s)。结果提示:(1)正常小儿脊髓活动左右对称,不同脊髓节段对PTN刺激反应不同。(2)脑瘫小儿脊髓活动左右不对称,一侧功能下降时对侧有一定代偿力,脊髓传导速度减慢。     

Preliminary Studies on the Optimum Shape of Dental Bridges

Several pre-existing anterior and posterior dental bridge models using Finite elements and the new ceramic material In-Ceram have been developed. The mechanical behaviour of these models has been compared with optimised profiles obtained from a newly developed evolutionary algorithm known as Evolutionary Structural Optimisation (ESO).

The results show that the mechanical behaviour of the bridges was mainly restricted by the properties of the porcelain veneer and the design of the bridges themselves. For the case of the anterior bridge, it was found that there existed a specific thickness of veneer that minimised the maximum principal stress. This was related to peak stresses that occurred at the bridge surface. Peak stresses also occurred in the material interface between the In-Ceram and the veneer. These extreme stresses were attributed to the notch size and shape. For the case of the posterior bridge, it was concluded that the shape of the bottom of the Pontic tooth is crucial in reducing the magnitude of the maximum principal tensile stress. The ESO process produced bridge designs which have uniformly stressed bridge surfaces, and which also have significantly lower maximum principal tensile stresses compared to the pre-existing designs (up to 44%).     

PmMGST3, a novel microsomal glutathione S-transferase gene in the dinoflagellate Prorocentrum minimum, is a potential biomarker of oxidative stress

In this study, we evaluated a novel microsomal glutathione S-transferase3 (MGST3) gene from the dinoflagellate Prorocentrum minimum, and examined its expression pattern in response to copper-and nickel-induced stresses. The full length of PmMGST3 was 732 bp, ranging from the dinoflagellate splice leader (DinoSL) sequence to the poly (A) tail, covering a 441-bp ORF, 97-bp 5′UTR, and 194-bp 3′UTR. The PmMGST3 was up-regulated by metals, including copper and nickel. The highest up-regulation levels of the PmMGST3 were found under 0.1 mg/L copper and 0.5 mg/L nickel treatment, respectively. In addition, the PmMGST3 was gradually up-regulated by 0.1 mg/L copper with increasing exposure time. Furthermore, ROS production and reduced GSH was measured in the copper treated cells. A significant increased ROS production and reduced GSH were found in the copper treated cells. These results suggest that PmMGST3 may be related to defense mechanisms associated with oxidative stress in dinoflagellates.     

MMP-1 promoter genotype and haplotype association with posterior tibial tendinopathy

Purpose

Posterior tibial tendon (PTT) is particularly vulnerable and its insufficiency is recognized as the main cause of adult acquired flatfoot. Some patients have a predisposition without clinically recognized cause, suggesting that individual characteristics play an important role in tendinopathy. The objective of the present study is to investigate the association of − 519 (rs1144393) matrix metalloproteinase-1 (MMP-1) polymorphism and the − 1607 (rs1799750) and − 519 MMP-1 haplotypes and risk of PTT dysfunction.

Methods

The test group included 50 females who presented PTT dysfunction Grade 2 or 3, and who were submitted to surgical treatment, with histopathological examination of the tendon and magnetic resonance image (MRI) confirming tendinopathy, while the control group was 100 asymptomatic women who present intact PTT at MRI. We analyzed functional polymorphisms MMP-1 and their haplotypes using polymerase chain reaction and restriction fragment length analysis.

Results

There was a significant difference in the presence of the different alleles and genotypes between the control group and test group for the MMP-1 gene (p ≤ 0.01). The G allele of the − 519 MMP-1 polymorphism increased susceptibility to degeneration in the PTT tendon and seems to be a genetic risk factor. Global haplotype analysis indicated a significant difference between both groups (p < 0.0001). Haplotypes G–2G and A–2G had statistically significant risk effect on PTT insufficiency. G–2G, p < 0.001; OR = 5.72 (CI, 2.84–11.52) and A–2G p = 0.002, OR = 3.95 (CI, 1.65–9.44).

Conclusion

According to our results, − 519 MMP-1 isolated and − 1607/− 519 MMP-1 haplotypes are associated to tendinopathy in posterior tibial tendon.     

A new iridescent tarantula of the genus Thrigmopoeus Pocock, 1899 from Western Ghats,India

A distinctive new species of ground burrowing tarantula from Western Ghats endemic genus Thrigmopoeus is described from Kerala State, India. Thrigmopoeus psychedelicus sp. nov. differs from putative species of the genus in the adults being black overall with a metallic blue lustre on the carapace and abdomen. Females of Thrigmopoeus psychedelicus sp. nov. exhibit polychromatism. Juveniles and sub-adults are paler with vibrant maroon colouration on its abdomen whereas adult females are much darker and lack vibrant colouration as sub-adults.