The new biology of ageing

Human life expectancy in developed countries has increased steadily for over 150 years, through improvements in public health and lifestyle. More people are hence living long enough to suffer age-related loss of function and disease, and there is a need to improve the health of older people. Ageing is a complex process of damage accumulation, and has been viewed as experimentally and medically intractable. This view has been reinforced by the realization that ageing is a disadvantageous trait that evolves as a side effect of mutation accumulation or a benefit to the young, because of the decline in the force of natural selection at later ages. However, important recent discoveries are that mutations in single genes can extend lifespan of laboratory model organisms and that the mechanisms involved are conserved across large evolutionary distances, including to mammals. These mutations keep the animals functional and pathology-free to later ages, and they can protect against specific ageing-related diseases, including neurodegenerative disease and cancer. Preliminary indications suggest that these new findings from the laboratory may well also apply to humans. Translating these discoveries into medical treatments poses new challenges, including changing clinical thinking towards broad-spectrum, preventative medicine and finding novel routes to drug development.     

Identification of Tumor Antigens in the HLA Peptidome of Patient-derived Xenograft Tumors in Mouse

1. Download : Download high-res image (147KB)
2. Download : Download full-size image

Highlights

• •Sufficient tumor tissues are often unavailable large HLA peptidome discovery.
• •Using patient derived xenograft (PDX) tumors can overcome this limitation.
• •The large PDX HLA peptidomes expand significantly those of the original biopsies.
• •The HLA peptidomes of the PDX tumors included many tumor antigens.

     

Tungsten-based material as promising new lead-free gamma radiation shielding material in nuclear medicine

PurposeThe main objective of this study was to evaluate the efficacy of tungsten carbide as new lead-free radiation shielding material in nuclear medicine by evaluating the attenuation properties.Materials and methodsThe elemental composition of tungsten carbide was analysed using Field-Emission Scanning Electron Microscopy (FESEM) with energy dispersive X-ray (EDX). The purity of tungsten carbide was 99.9%, APS: 40–50 µm. Three discs of tungsten carbide was fabricated with thickness of 0.1 cm, 0.5 cm and 1.0 cm. Three lead discs with similar thickness were used to compare the attenuation properties with tungsten carbide discs. Energy calibration of gamma spectroscopy was performed by using ¹²³I, ¹³³Ba, ¹⁵²Eu, and ¹³⁷Cs. Gamma radiation from these sources were irradiated on both materials at energies ranging from 0.160 MeV to 0.779 MeV. The experimental attenuation coefficients of lead and tungsten carbide were compared with theoretical attenuation coefficients of both materials from NIST database. The half value layer and mean free path of both materials were also evaluated in this study.ResultsThis study found that the peaks obtained from gamma spectroscopy have linear relationship with all energies used in this study. The relative differences between the measured and theoretical mass attenuation coefficients are within 0.19–5.11% for both materials. Tungsten carbide has low half value layer and mean free path compared to lead for all thickness at different energies.ConclusionThis study shows that tungsten carbide has high potential to replace lead as new lead-free radiation shielding material in nuclear medicine.     

Gut Microbiome Fermentation Determines the Efficacy of Exercise for Diabetes Prevention

1. Download : Download high-res image (179KB)
2. Download : Download full-size image

     

Enthesopathies (lesions of muscular insertions) as indicators of the activities of neolithic Saharan populations

Enthesopathies are bony lesions involving the sites of insertion of muscles or ligaments. Those caused by hyperactivity of the relevant muscles may be distinguished clearly from those of metabolic or inflammatory origin. Observations from sporting and occupational medicine indicate that specific enthesopathies are correlated with different activities. Examination of the enthesopathies present on two groups of well-preserved neolithic skeletons from separate regions of the Sahara with different paleoenvironments show that overall 20% of the skeletons presented lesions. Three different forms of enthesopathy involved the arm, principally the elbow, and may be tentatively correlated with javelin throwing, wood cutting, and archery. Two types of lesion involving the foot were observed in skeletons from a hunter-gatherer population and may be correlated with much walking or running over hard ground. I suggest that the analysis of such lesions on ancient skeletons may, in concert with other archaeological data, throw light on the activities of ancient people.     

藏马鸡(Crossoptilon crossoptilon)的繁殖生态研究

藏马鸡是典型高山地牺雉类,见于海拔3,500—3,900米的针叶林带。自4月中至7月底为繁殖期。一“夫”配一“妻”。营巢于海拔3,544—3,790米的岩洞、灌丛中或倒木下。共发现4巢,3巢已被破坏,成功率25％。近年来,由于过渡砍伐森林,天敌的伤害,自身弱点(繁殖率低,成熟期长(3年左右)以及其他因素,藏马鸡的数量日趋减少,正面临绝种的厄运。必须及时地采取有效保护措施。     

青海藏族青少年骨龄与生长发育关系研究

本文报告了青海省境内,世居在海拔3000-4000米地区的728名7-18岁健康藏族青少年学生的手、腕部骨骼发育情况,对骨化中心出现和骨骺愈合求出了50%出现年龄,并对骨龄与青春期身高突增的关系及与月经初衬潮的关系进行了分析。     

关于几种避孕植物药的药理初筛及成份预试

本文对云南滇西地区民间用于避孕和绝育秘方中的槌果藤,野花椒寄生、花椒寄生、螃蟹树寄生、鸡矢藤及野花椒的醇提取物进行了小鼠最大耐受量测定及小鼠抗生育实验,结果表明,花椒寄生、螃蟹树寄生的醇提取物具有明显抗生育活性,槌果藤也具有一定的抗生育作用。此外,还对槌果藤、野花椒寄生进行了化学成份预试。