Molecular and morphological identification of two new African species of Dugesia (Platyhelminthes,Tricladida, Dugesiidae) from Cameroon

The paper describes two new Dugesia species collected from the rivers Messassi and Ntsetsensooh in Cameroon, representing the first planarian flatworms documented from this country. Based on morphological data, the new species Dugesia bijuga Harrath & Sluys, sp. nov. is characterized mainly by the presence of two diaphragms, a barrel-shaped penis that is traversed by numerous ducts of penis glands and is provided with a short nozzle, and the presence of two atrial folds. The other new species, Dugesia pustulata Harrath & Sluys, sp. nov., is characterized mainly by absence of a penis bulb, presence of a large, elongated and weakly muscular seminal vesicle, and by the ventroposterior section of the bursal canal being thrown into distinct folds. The phylogenetic position of the two new species was determined through a molecular phylogenetic tree, based on a mitochondrial and a nuclear gene, including species from the major geographical range of distribution of the genus Dugesia. The phylogenetic tree revealed that the Cameroon lineage does not constitute a monophyletic group with the other Afrotropical species; it also showed that the African continent may house a great diversity of Dugesia species that still remains to be discovered.

urn:lsid:zoobank.org:pub:007441A5-F037-4950-9F5B-AD6ED12A40ED     

结构型E-V线性模型中参数估计的若干结果

由于E-V线性模型的复杂性,通常的最小二乘估计等在这种模型中一般不是相合的。本文在结构型简单线性模型中,利用矩方法与秩方法建立了若干估计量,并且论证了这些估计量的相合性与渐近正态性,报告了主要结果。     

Increase in neuronal nitric oxide synthase content of the gastroduodenal tract of diabetic rats

This study examined the changes occurring in the pattern of distribution and expression of neuronal nitric oxide synthase (nNOS)-positive nerves in the gastroduodenal tract of streptozotocin-induced diabetic rats. The ganglion cells of the myenteric plexus of the gastric antrum of normal rats contain nNOS. We also observed nNOS-positive neurons and fibres in the myenteric plexus of the duodenum of normal rats. After the onset of diabetes, the number and intensity of staining of nNOS-positive nerve profiles in the gastric antrum and duodenum did not change significantly. However, Western blotting showed a significant increase in the expression of nNOS after the onset of diabetes. In conclusion, diabetes of 4 and 32 weeks duration induced an increase in the tissue content of nNOS in the gastroduodenum of rat. The increase in the level of nNOS in the gastroduodenum of diabetic rats may explain why impaired gastric emptying is common in patients with diabetes.     

Differential modulation of endotoxin responsiveness by human caspase-12 polymorphisms

Caspases mediate essential key proteolytic events in inflammatory cascades and the apoptotic cell death pathway. Human caspases functionally segregate into two distinct subfamilies: those involved in cytokine maturation (caspase-1, -4 and -5) and those involved in cellular apoptosis (caspase-2, -3, -6, -7, -8, -9 and -10). Although caspase-12 is phylogenetically related to the cytokine maturation caspases, in mice it has been proposed as a mediator of apoptosis induced by endoplasmic reticulum stress including amyloid-beta cytotoxicity, suggesting that it might contribute to the pathogenesis of Alzheimer's disease. Here we show that a single nucleotide polymorphism in caspase-12 in humans results in the synthesis of either a truncated protein (Csp12-S) or a full-length caspase proenzyme (Csp12-L). The read-through single nucleotide polymorphism encoding Csp12-L is confined to populations of African descent and confers hypo-responsiveness to lipopolysaccharide-stimulated cytokine production in ex vivo whole blood, but has no significant effect on apoptotic sensitivity. In a preliminary study, we find that the frequency of the Csp12-L allele is increased in African American individuals with severe sepsis. Thus, Csp12-L attenuates the inflammatory and innate immune response to endotoxins and in doing so may constitute a risk factor for developing sepsis.     

线性统计模型中回归分位点的强相合性及渐近正态性(英文)

论证了线性模型中回归分位点估计量的强相合性及渐近正态性等大样本性质 ,这些结果推广了陈希孺等 ( 1 990 ,1 992 )的有关定理 ,改进了Koenker与Basstee( 1 978) ,Gutenburnner与Jurec∨kova( 1 992 ) ,以及Jurec∨kovo与Prochazka( 1 994)等人的有关成果。     

Effect of consumption of green and black tea on the level of various enzymes in rats

Drinking of both green and black tea as the only liquid ingested resulted in significant decreases in the activity of transketolase in whole blood of rats both before and after the in vitro addition of thiamin diphosphate. Liver transketolase activity was decreased only by green tea. Mucosal transketolase activity was not affected by either type of tea. The activity of lactate dehydrogenase (LDH) was not affected by either type of tea, while whole blood LDH was decreased by both green and black tea. Neither tea had any affect on mucosal alkaline phosphatase, but thiamin diphosphatase activity was decreased by both teas. An increase in liver total thiamin resulted from the drinking of both types of tea.     

Neuronal ensemble control of prosthetic devices by a human with tetraplegia

Neuromotor prostheses (NMPs) aim to replace or restore lost motor functions in paralysed humans by routeing movement-related signals from the brain, around damaged parts of the nervous system, to external effectors. To translate preclinical results from intact animals to a clinically useful NMP, movement signals must persist in cortex after spinal cord injury and be engaged by movement intent when sensory inputs and limb movement are long absent. Furthermore, NMPs would require that intention-driven neuronal activity be converted into a control signal that enables useful tasks. Here we show initial results for a tetraplegic human (MN) using a pilot NMP. Neuronal ensemble activity recorded through a 96-microelectrode array implanted in primary motor cortex demonstrated that intended hand motion modulates cortical spiking patterns three years after spinal cord injury. Decoders were created, providing a 'neural cursor' with which MN opened simulated e-mail and operated devices such as a television, even while conversing. Furthermore, MN used neural control to open and close a prosthetic hand, and perform rudimentary actions with a multi-jointed robotic arm. These early results suggest that NMPs based upon intracortical neuronal ensemble spiking activity could provide a valuable new neurotechnology to restore independence for humans with paralysis.     

Specific immune responses induced by a multi-epitope antigen of hepatitis C virus in mice and rabbits

Five highly conserved and immunogenic epitopes of hepatitis C virus (HCV) have been chosen to form a multi-epitope antigen gene and fused with β-galactosidase gene to express a hybrid GZ-PCX antigen, which could be specifically recognized by human HCV sera. High level of anti-GZ-PCX IgG has been induced when mice or rabbits were immunized with GZ-PCX antigen emulsificated with complete Freund’s adjuvant or mixed with killed attenuatedSalmonella typhimurium SL3261. The specific anti-GZ-PCX IgG reached a high titer of 10^-6, which remained for several months. Specific cytotoxic T lymphocyte (CTL) effects, delayed type hypersensitivity reaction (DTH) and proliferation of peripheral lymphocytes have been induced by GZ-PCX antigen or synthetic peptides. High level of anti-GZ-PCX slgG has been detected in mice’s intestinal washing fluids, which indicates that the antigen induced mucosal immunity as well as systematic immunity. The studies show that the HCV multi-epitope antigen induces high level of specific immune responses without obvious toxicity, which might be able to provide protectivity to any HCV genotypes and isolates.