河南舞阳大岗细石器地点发掘报告

本文记述的是河南省舞阳县大岗细石器地点第４层出土的石制品,它属于以楔状石核为特征的细石器技术传统,上覆的第３层属于新石器时代裴李岗文化晚期,它的发现对研究细石器技术传统的分布和发展,探讨中原细石器遗存与新石器时代早期文化的关系等都具有一定的意义。     

Greater capillary-fiber interface per fiber mitochondrial volume in skeletal muscles of old rats.

The objective was to examine whether muscle structural capacity for O2 flux (i.e., capillary-to-fiber surface ratio) relative to fiber mitochondrial volume deteriorates with the muscle atrophy of aging in predominantly slow- (soleus, S) and fast-twitch (extensor digitorum longus, EDL) muscles of old (24 mo) and very old (35 mo) F344BN rats compared with adult (12 mo old). Wet muscle mass decreased 29% (196 +/- 4 to 139 +/- 5 mg) in S and 22% (192 +/- 3 to 150 +/- 3 mg) in EDL between 12 and 35 mo of age, without decline in body mass. Capillary density increased 65% (1,387 +/- 54 to 2,291 +/- 238 mm(-2)) in S and 130% (964 +/- 95 to 2,216 +/- 311 mm(-2)) in EDL, because of the muscle fiber atrophy, whereas capillary per fiber number remained unchanged. Altered capillary geometry, i.e., lesser contribution of tortuosity and branching to capillary length, was found in S at 35 compared with 12 and 24 mo, and not in EDL. Accounting for capillary geometry revealed 55% (1,776 +/- 78 to 2,750 +/- 271 mm(-2)) and 113% (1,194 +/- 112 to 2,540 +/- 343 mm(-2)) increases in capillary length-to-fiber volume ratio between 12 and 35 mo of age in S and EDL, respectively. Fiber mitochondrial volume density was unchanged over the same period, causing mitochondrial volume per micrometer fiber length to decrease in proportion to the fiber atrophy in both muscles. As a result of the smaller fiber mitochondrial volume in the face of the unchanged capillary-to-fiber number ratio, capillary-to-fiber surface ratio relative to fiber mitochondrial volume not only did not deteriorate, but in fact increased twofold in both muscles between 12 and 35 mo of age, independent of their different fiber type.     

Validation of portable muscle tone measurement device for quantifying velocity-dependent properties in elbow spasticity.

The objective of this study is to develop a portable device for quantifying the velocity-dependent properties of spastic elbow muscles. Based on a motor-driven system, validation tests of the portable system such as accuracy and response of sensors were first examined. Furthermore, simulated modules (inertia, damper and spring) as well as elbow joints (15 control and 15 hemiplegic subjects) were manually stretched under four different frequencies (1/3, 1/2, 1 and 3/2 Hz) through 60 degrees range of motion. Joint resistance and displacement during sinusoidal stretch were collected for further analysis. Two quantitative parameters (i.e., viscous components under each frequency and averaged viscosity across four frequencies) were derived to estimate the velocity-dependent properties of elbow joint. Tests of simulated modules confirm the manual stretch protocol and data analysis are valid in estimating the velocity-dependent component during a sinusoidal stretch. Compared to normal control, viscous component in each stretch frequency and averaged viscosity were significantly higher in subjects with spasticity (P < 0.001). The viscous component and averaged viscosity were found highly correlated with the modified Ashworth scale. These findings suggest that measurements of viscous component and averaged viscosity during manual sinusoidal stretching using the portable device could be clinically useful in evaluating spasticity.     

Evaluation of flavonoids from <Emphasis Type="Italic">Zostera asiatica</Emphasis> as antioxidants and nitric oxide inhibitors

Zostera asiatica is one of the five members of the genus Zostera that can be found in Korea. Studies have reported the phytochemical properties and bioactivities of Zostera species. Current study focused on the antioxidant effects of Z. asiatica as a part of ongoing research for bioactive substances from marine resources. Results indicated that a crude extract of Z. asiatica not only scavenged on peroxynitrite in vitro and on intracellular reactive oxygen species (ROS) but also inhibited production of nitric oxide (NO). The crude extract was subjected to solvent fractionation for bioactivity-based separation using aforementioned three bioassay systems. From the active n-butanol fraction, two flavonoids were isolated and characterized as luteolin (1) and luteolin-3’-sulfate (2). Both flavonoids showed significant antioxidant effects. In conclusion, Z. asiatica was demonstrated to possess antioxidant effect partly attributed to isolated flavonoids, the first such effect reported from Z. asiatica, to the best of our knowledge.     

Streptomyces-derived actinomycin D inhibits biofilm formation by Staphylococcus aureus and its hemolytic activity

Staphylococcus aureus is a versatile human pathogen that produces diverse virulence factors, and its biofilm cells are difficult to eradicate due to their inherent ability to tolerate antibiotics. The anti-biofilm activities of the spent media of 252 diverse endophytic microorganisms were investigated using three S. aureus strains. An attempt was made to identify anti-biofilm compounds in active spent media and to assess their anti-hemolytic activities and hydrophobicities in order to investigate action mechanisms. Unlike other antibiotics, actinomycin D (0.5 μg ml^?1) from Streptomyces parvulus significantly inhibited biofilm formation by all three S. aureus strains. Actinomycin D inhibited slime production in S. aureus and it inhibited hemolysis by S. aureus and caused S. aureus cells to become less hydrophobic, thus supporting its anti-biofilm effect. In addition, surface coatings containing actinomycin D prevented S. aureus biofilm formation on glass surfaces. Given these results, FDA-approved actinomycin D warrants further attention as a potential antivirulence agent against S. aureus infections.     

Cytosolic PINK1 promotes the targeting of ubiquitinated proteins to the aggresome-autophagy pathway during proteasomal stress

During proteasomal stress, cells can alleviate the accumulation of polyubiquitinated proteins by targeting them to perinuclear aggresomes for autophagic degradation, but the mechanism underlying the activation of this compensatory pathway remains unclear. Here we report that PINK1-s, a short form of Parkinson disease (PD)-related protein kinase PINK1 (PTEN induced putative kinase 1), is a major regulator of aggresome formation. PINK1-s is extremely unstable due to its recognition by the N-end rule pathway, and tends to accumulate in the cytosol during proteasomal stress. Overexpression of PINK1-s induces aggresome formation in cells with normal proteasomal activities, while loss of PINK1-s function leads to a significant decrease in the efficiency of aggresome formation induced by proteasomal inhibition. PINK1-s exerts its effect through phosphorylation of the ubiquitin-binding protein SQSTM1 (sequestosome 1) and increasing its ability to sequester polyubiquitinated proteins into aggresomes. These findings pinpoint PINK1-s as a sensor of proteasomal activities that transduces the proteasomal impairment signal to the aggresome formation machinery.