Lordosis induction in the rat by prostaglandin E2 systemically or intracranially in the absence of ovarian hormones

Within 20 minutes of an intraperitoneal injection, PGE₂ induced lordosis responding to manual stimulation in 6 of 9 rats that were ovariectomized-hysterectomized and hormonally untreated. Similarly, intracranial application of PGE₂, through guide cannulae that were chronically-implanted in the basal hypothalamus, induced lordosis responding to manual stimulation within 10 minutes in ovariectomized, hormonally-untreated rats.     

Changes in conformation and nucleotide binding of Ca, Mn, or MgG-actin upon removal of the bound divalent cation. Studies of ultraviolet difference spectra and optical rotation

The ultraviolet difference spectra of EDTA-induced denaturation of dithiothreitoltreated actin prepared with either Ca²⁺, Mn²⁺, or Mg²⁺ as the strongly bound cation showed no appreciable difference, nor could any difference be found in the change of optical rotation. However, at different wavelengths the changes in the spectra have different rates and these rates do differ significantly depending on the bivalent cation bound to G-actin. The nucleotide and the cation appear to be removed simultaneously and at the fastest rate; about 50–80% is released within 1 min. The spectral changes have two phases: a fast change whose detailed kinetics have not been investigated in this paper, followed by a slower rate with first-order kinetics. The changes of optical rotation follow a single-phase first-order kinetics. The rates depend on the divalent cation, the sequence being Mn²⁺ > Ca²⁺ > Mg²⁺. ATP release is partially reversible upon Ca²⁺ addition; the reversibility is diminished as the time of incubation with EDTA is increased. On rebinding of ATP and Ca²⁺, the spectral and optical rotatory changes are not reversed, but no further changes occur. Such an EDTA-treated actin is polymerizable after addition of Ca²⁺, and the G-actin obtained after polymerization and depolymerization shows the same spectral change on a second addition of EDTA as the original actin. On the basis of these observations a scheme is suggested for the denaturation of G-actin.     

Impairments in availability of insulin to liver in vivo and in binding of insulin to purified hepatic plasma membrane during aging

The concentration of insulin in portal vein blood decreases 50–60% in fed or fasted rats as they age from 12- to 24-months. The binding capacity of purified hepatic plasma membrane for insulin decreases approximately 60% as rats age from 2- to 24-months, whereas the dissociation constant for insulin is not altered. It is proposed that these factors may contribute significantly to previously documented examples of age-dependent modifications in liver enzyme regulation.     

Spatial Pattern of Pindó Palm (Syagrus romanzoffiana) Recruitment in Argentinian Atlantic Forest: The Importance of Tapir and Effects of Defaunation

Hunting pressure, fragmentation and deforestation have caused global declines in animal abundance, and the consequences for plant communities are poorly understood. Many large‐seeded plants, for instance, depend on large and endangered vertebrates for seed dispersal. In some Semi‐deciduous Atlantic Forests, endangered tapirs (Tapirus terrestris) are major dispersers of pindó palms (Syagrus romanzoffiana). Here, we compare recruitment patterns of pindó palms between protected and disturbed (defaunated) Atlantic Forest areas in Argentina and evaluate the potential consequences of the lack of the main disperser for pindó palm regeneration. We analyzed the number and spatial pattern of pindó adults, offspring, and tapir dung piles within ten plots established in an area spanning tapir latrines inside Iguazú National Park and in a fragmented forest area outside the park where tapir is locally extinct. In both areas, we evaluated recruitment levels beneath 24 adult palms in circular plots centered on adult stems. We found lower pindó palm recruitment outside the park where offspring tended to be aggregated around adult palms. In contrast, in Iguazú National Park offspring were spatially associated with tapir dung‐piles, in which most offspring were registered. Recruitment under adults was higher outside the park suggesting a lower rate of seed removal in disturbed areas. Our results show that tapir dispersal promotes higher recruitment levels of pindó offspring and shapes their spatial pattern, breaking the spatial association with adult (presumably maternal) palms. These results are useful for predicting the impact of local tapir extinction on this palm.     

Species inventory,ecology, and seasonal distribution patterns of Culicidae (Insecta: Diptera) in the National Park Donau-Auen (Lower Austria)

In order to improve the limited database on species inventories and ecology of Culicidae in Austria, we monitored hydrological and physico-chemical parameters of breeding habitats of the Culicidae species of Danubean wetlands from March to October 2011 in the National Park Donau-Auen (Lower Austria). A total of 34 eggrafts, 1022 larval, 80 pupal, and 221 adult Culicidae were collected. We detected 15 mosquito species belonging to the genera Anopheles Meigen, 1818, Culex Linnæus, 1758, Culiseta Felt, 1904, Coquillettidia Dyar, 1905, Aedes Meigen, 1818 and Ochlerotatus Lynch Arribalzaga, 1891. In the larval and pupal stage, Ochlerotatus geniculatus (Olivier, 1791) (64.1%) and Culex territans Walker, 1856 (18.7%) were most abundant. Based on abiotic and biotic parameters, sampling sites were grouped into four clusters. The results show that water level and -persistence, pH, conductivity, and phosphate concentrations had a significant influence on species distribution, and that floodplain dynamics are a key factor for the seasonal and spatial distribution of mosquito larvae in the National Park.     

Association of the SNP rs2623047 in the HSPG modification enzyme SULF1 with an Australian Caucasian Breast Cancer Cohort

Breast cancer is the second most common cancer worldwide and the most common cancer reported in women. This malignant tumour is characterised by a number of specific features including uncontrolled cell proliferation. It ranks fifth in the world as a cause of cancer death overall in developed countries and is the second most frequent cause of cancer death in women. Early diagnosis increases 5-year survival rates up to 95%. Heparan sulfate proteoglycans (HSPGs) are complex proteins composed of a core protein to which a number of highly sulfated side chains attach, ubiquitous to the cell surface and within the extracellular matrix. HSPG side chains are synthesised by a highly co-ordinated process resulting in distinct sulfation patterns, which determine specific interactions with cell-signalling partners including growth factors, their receptors, ligands and morphogens. The enzymes responsible for chain initiation, elongation and sulfation are critical for creating HS chain variability conferring biological functionality. This study investigated a single nucleotide polymorphism in SULF1, the enzyme responsible for the 6-O desulfation of heparan sulfate side chains. We investigated this SNP in an Australian Caucasian case–control breast cancer population and found a significant association between SULF1 and breast cancer at both the allelic and genotypic levels (allele, p = 0.016; genotype, p = 0.032). Our results suggest that the rs2623047 SNP in SULF1 may impact breast cancer susceptibility. Specifically, the T allele of rs2623047 in SULF1 is associated with an increased risk of developing breast cancer in our cohort. The identification of markers including SULF1 may improve detection of this disease at its earliest stages improving patient treatment and prognosis.     

RAGE与阿尔茨海默病关系的研究进展

阿尔茨海默病属于神经系统退行性疾病,该类疾病给社会和家庭带来了沉重的负担,且目前尚无一疗效突破性药物,已经成为一个严重的社会问题和经济问题。Aβ是阿尔茨海默病的重要发病机制之一,通过多种途径介导神经损伤,其中与细胞表面的结合位点结合而引发的病理损害成为当今的前沿认识。一方面,它们可以使Aβ聚集,造成细胞膜的直接损伤;另一方面,它们可以以受体的形式,参与细胞内的信号传导;另外,还可以激活细胞内吞作用,通过溶酶体途径造成细胞损伤。关于与Aβ结合的细胞表面结合位点,晚期糖基化终末产物受体备受瞩目。它是一种多功能受体,属于细胞表面免疫球蛋白家族成员,在神经元、小胶质细胞以及血管内皮细胞上都有表达,Aβ是它的配体之一。研究已证实,它与Aβ相互作用,通过激活细胞内不同的信号通路,对阿尔茨海默病的发生发展发挥重要作用。随着对它的不断深入研究,有望在防治退行性疾病方面产生新的治疗策略与措施。     

The Megophthalmidia (Diptera,Mycetophilidae) of North America including eight new species

Megophthalmidia Dziedzicki is a small leiine genus (Mycetophilidae) with seven species described from the Neotropics and ten species from the Palearctic region. Two species of Megophthalmidia have been reported for North America. Recent collecting of Mycetophilidae in California and Arizona, however, shows current North American diversity of Megophthalmidia is at least on par to other regions of the world. Eight new species of Megophthalmidia are described here, increasing the number of Nearctic Megophthalmidia species to nine. Included is a particularly atypical member of the genus, M. saskia sp. n., which expands the genus concept of Megophthalmidia. Of the two species previously recorded for North America, only one actually belongs in the genus. Megophthalmidia occidentalis Johannsen, is fully described and illustrated. The other named species, M. marceda (Sherman) is illustrated and transferred to the genus Ectrepesthoneura Enderlein. A lectotype is designated for this species. A key to the species of Megophthalmidia of North America is provided. The biology of these flies is not yet known. Three of the new Megophthalmidia species – M. lenimenta, M. misericordia, and M. radiata – are only known to occur within small protected areas within the California State Park and UC Natural Reserve systems.