The influence of dietary flaxseed and other grains, fruits and vegetables on the frequency of spontaneous chromosomal damage in mice

Spontaneous genetic damage, whether mutations or chromosomal aberrations, undoubtedly arise from a variety of sources including replication errors, oxidative damage, background radiation, and chemical exposure. Given the numerous correlations between diet and cancer, it seemed possible that diet could influence the spontaneous rate of DNA damage and its genetic consequences. Since diets high in vegetables, fruits, and grains are associated with lower rates of cancer, we supplemented the diets of mice and measured the frequency of micronuclei in the peripheral blood. Micronuclei arise from broken chromosomes or chromosome loss in the erythroblast. They are first seen in the short reticulocyte stage of the red blood cell but persist for the entire 30-day lifespan of the cell in mice. C57Bl mice were placed on a defined diet (AIN-93G) supplemented to 20% final dry weight with grains or freeze-dried fruits or vegetables. The micronucleus frequency was measured in a pre-exposure blood sample and every 2 weeks thereafter for 6 weeks. This was possible in spite of the low spontaneous frequency of 1/1000-2/1000 cells by the use of a novel flow cytometric method, which permitted the analysis of both the mature red blood cells and reticulocytes. Of the foods tested, flaxseed proved to be the most protective by reducing the incidence of micronuclei in both the reticulocyte and normochromatic erythrocyte cell populations by 30 and 11%, respectively. The results show that at least one class of spontaneous genetic damage can be modified by diet and suggests that short-term experiments with small numbers of animals can be used to identify dietary anticarcinogens that may influence human cancer rates.     

Effect of captopril or verapamil on intracellular sodium in cultured vascular smooth muscle cells

INTR0DUCTIONVascularsmoothmusclecellsp0ssessanumber0fNa transportsystems,namelyNa channels,Na -Ca' ,Na -H exchange,andNa -K -2Cl-c0-transp0rt[1].Hypothesizedr0lesf0rthesesystemsincluderegulati0n0fvasculart0ne,cellvolumeandcellproliferation.Inb0thexperimentalandhumanhypertensi0naberrationsinsm00thmusclecell,univalenti0ntransportsystemplayanimp0rtantroleinthepathogenesisandmaintenanceofhypertensi0n[2].Angiotensinc0nvertingenzyme(ACE)inhibitorsandCa2 antagonistsarewidelyusedforthetreatm…     

Visualizing the microtubule-associated protein tau in the nucleus

Although tau is mainly known as an axonal microtubule-associated protein,many studies indicate that it is not restricted to this subcellular compartment.Assessing tau’s subcellular distribution,however,is not trivial as is evident from transgenic mouse studies.When human tau is over-expressed,it can be immunohistochemically localized to axons and the somatodendritic domain,modeling what is found in neurodegenerative diseases such as Alzheimer’s disease.Yet,in wild-type mice,despite its abundance,tau is difficult to visualize even in the axon.It is even more challenging to detect this protein in the nucleus,where tau has been proposed to protect DNA from damage.To establish a framework for future studies into tau’s nuclear functions,we compared several methods to visualize endogenous nuclear tau in cell lines and mouse brain.While depending on the fixation and permeabilization protocol,we were able to detect nuclear tau in SH-SY5Y human neuroblastoma cells,we failed to do so in N2a murine neuroblastoma cells.As a second method we used subcellular fractionation of mouse tissue and found that in the nucleus tau is mainly present in a hypophosphorylated form.When either full-length or truncated human tau was expressed,both accumulated in the cytoplasm,but were also found in the nuclear fraction.Because subcellular fractionation methods have their limitations,we finally isolated nuclei to probe for nuclear tau and found that the nuclei were free of cytoplasmic contamination.Together our analysis identifies several protocols for detecting tau in the nucleus where it is found in a less phosphorylated form.     

QTL mapping of economically important traits in Silkworm (Bombyx mori)

The construction of linkage map is both a funda-mental research area and an important aspect of gene analyses in genetics. It provides the guidelines for breeding. A sound linkage map is also necessary for further genetic analysis. In recent years, great and rapid progress has been made in molecular biology, which enables fingerprinting of organisms at the ge-nomic level. Many molecular marker techniques have been well established. Heartening progress has been made in many organisms in the co…     

Temporal expression of c-kit in spermatogenesis of two grasshopper species

Two species of grasshoppers, Calliptamus abbreviatus （Ikonn.） and Shirakiacris shirakii （I. Bol.）, were collected randomly in the Siping area of Jilin Province, China. By using immunohistochemical methods and statistical analysis, we observed and compared the temporal expression of c-kit protein in four representative stages of spermatogenesis of the two grasshoppers, namely： spermatogonia; primary spermatocyte; secondary spermatocyte; and mature sperm. Results showed that there was c-kit positive temporal expression at each stage of spermatogenesis, but there were different positive expression levels： （i） weak positive expression of c-kit protein appeared in spermatogonia and the positive granules were thinner; （ii） strong positive expression of c-kit protein existed in primary spermatocyte and positive granules became biggest among all developmental stages; （iii） c-kit positive expression stayed stronger in secondary spermatocyte while positive granules became thinner; （iv） there was a strong positive expression of c-kit and thinner positive granules in mature sperm, which distributed on head and tail; （v） the biggest c-kit positive granules had been found massing at the end of spermary; and （vi） significant differences of c-kit positive expression existed in spermatogenesis between two species of grasshoppers. The results indicated that c-kit protein may play a crucial role in spermatogenesis and even retain the physiological action of sperms and fertilization in grasshoppers.     

Physical characteristics of Chinese Hakka

Using standard and internationally validated methods,86 anthropologic characteristics were determined in 650 male(305 from urban areas and 345 from rural areas) and 704 female(331 from urban areas,373 from rural areas) Chinese Hakka adults living in Guangdong and Jiangxi.The data were used to calculate 24 anthropologic indices,which were analyzed statistically.The physical characteristics of Hakka subjects were analyzed and compared with reference ethnic data.There were four main findings of this study.First,a small proportion of Hakka adults had an eye fold on the upper eyelid,but a large proportion had a mongoloid fold.The eye slits were narrow in most adults,had a medium nasal root height and straight bridges,and most of the external angles were prominent.The nasal base was upturned in most men.The distributions of the three types of nasal base in women were similar.The proportions of subjects with middle and high alae nasi heights were high and similar.Males with a maximum nostril diameter were mostly classified as transverse and oblique,while many women were classified as transverse and had relatively wide alae nasi.The round lobe type was the most common.Upper lip skin height was mostly classified as medium.Lips were classified as thin.The hair was black,eyes were brown,and the skin was yellowish.Second,the head length was long in male Hakka.The minimum frontal breadth,face breadth,lip height,and interocular breadth were similar to those of North-Asian populations.Meanwhile,head breadth,morphological facial height,nose breadth,mouth breadth,and nose height were similar to those of South-Asian populations.Head length was long in female Hakka.The minimum frontal breadth,face breadth,lip height,and interocular breadth were similar to those of North-Asian populations.Head breadth,nose breadth,and mouth breadth were similar to those of South-Asian populations.Third,the stature of male and female Hakka in urban and rural areas was classified as medium.The proportions of male and female Hakka classified as mesocephaly(length-breadth index of the head),hypsicephalic type,metriocephalic type(breadth-height index of the head) mesorrhiny,long trunk,subbrachyskelic type,broad shoulder breadth,and narrow distance between iliac crests were higher than those of other types.Finally,principal component analyses showed that the physical characteristics of Hakka were between those of South-Asian and North-Asian ethnic populations,but were generally closer to those of North-Asian populations in China.