Epidemiological analysis of poliomyelitis cases in 1994, China

In 1994, the number of reported polio cases was 307 in China. This number was 53% lower than that in 1993, and was the lowest record ever in China. In 1994, the distribution of polio cases was highly dispersed and the number of outbreak was reduced obviously. Of 225 counties which reported polio cases in 1994, polio outbreak occured in 2 counties. Cases due to polio outbreak accounted for 4.2% of the total cases. The distribution of polio wild virus was narrow but the regional difference still existed. In the southeast, high risk region for polio consisting Guangdong, Hainan, Fujian three provinces, the number of polio cases decreased remarkably in 1994. On the contrary, in the southwest region which, consisting Guangxi, Yunnan, Guizhou, Sichuan four provinces, the number of polio cases increased obviously, accounted for approximately a half of the total number in 1994. During the coming 1 to 2 years, we should emphasis on these regions and provinces where high incidence was noticed in our polio eradication program. Those provinces should include Xinjiang, Fujian. Hubei three provinces that polio wild virus was identified in 1994, and Guangxi, Sichuan, Guizhou, Yunnan in the south west region as well. We should further increase Polio vaccination coverage of children especially floating and unplanned ones through strengthening routine immunization and carring out new national immunization day activity.     

Comparison of the kinetics of injectable testosterone in eugonadal and hypogonadal men

Serum reproductive hormone levels were measured serially after eugonadal and hypogonadal men had received either a 200-mg or a 100-mg intramuscular injection of testosterone enanthate. The calculated mean integrated testosterone and estradiol levels indicated that the 200-mg testosterone enanthate injection in the hypogonadal subjects maintained eugonadal levels of these hormones through day 11. The 100-mg dose maintained eugonadal levels of these hormones through day 11. The 100-mg dose maintained eugonadal testosterone levels through day 7. The testosterone:estradiol ratios in both groups following the 200-mg injection remained above or at the eugonadal baseline trough day 21. The authors recommend that replacement therapy for hypogonadal men should be 200 mg of testosterone enanthate every 10 to 14 days. A similar dosage would be recommended if testosterone enanthate were to be used as an experimental inhibitor of spermatogenesis (contraceptive agent).     

Structure and tribological behavior of polydiene urethanes based on oligomeric compositions modified by polyfluorine alkyl organophilic montmorillonite

The paper presents the results of physical-mechanical, dynamical, tribological, and structural studies of composites based on polydiene urethane and montmorillonite modified by polyfluorinated alcohols. Data on the structural examination of the friction surface and the effect of the nature of organophilic montmorillonite on the properties of the filled polydiene urethane elastomers are discussed.     

Conductivity and Permittivity of Nickel-Nanoparticle-Containing Ceramic Materials in the Vicinity of Percolation Threshold

Conductivity and static permittivity of ceramic materials containing nanoparticles of Ni were measured in the vicinity of percolation threshold. It is found that, below this threshold, the experimentally obtained dependences of conductivity and static permittivity on the fractional Ni content in these materials are different from those calculated in the frame of the percolation theory. The origin of this discrepancy is discussed in terms of the network hierarchy model proposed recently by Balberg et al . for composite materials.     

DNA hypomethylation leads to elevated mutation rates

Genome-wide demethylation has been suggested to be a step in carcinogenesis. Evidence for this notion comes from the frequently observed global DNA hypomethylation in tumour cells, and from a recent study suggesting that defects in DNA methylation might contribute to the genomic instability of some colorectal tumour cell lines. DNA hypomethylation has also been associated with abnormal chromosomal structures, as observed in cells from patients with ICF (Immunodeficiency, Centromeric instability and Facial abnormalities) syndrome and in cells treated with the demethylating agent 5-azadeoxycytidine. Here we report that murine embryonic stem cells nullizygous for the major DNA methyltransferase (Dnmt1) gene exhibited significantly elevated mutation rates at both the endogenous hypoxanthine phosphoribosyltransferase (Hprt) gene and an integrated viral thymidine kinase (tk) transgene. Gene deletions were the predominant mutations at both loci. The major cause of the observed tk deletions was either mitotic recombination or chromosomal loss accompanied by duplication of the remaining chromosome. Our results imply an important role for mammalian DNA methylation in maintaining genome stability.     

Equirate magnetron sputtering of mosaic copper-graphite targets

Based on experimental data on sputtering of copper-graphite cathodes, we propose a mechanism of equirate sputtering of elements of mosaic targets prepared from materials the sputtering yields of which differ by almost an order of magnitude. The mechanism takes into account the occurrence of a height discontinuity between the mosaic elements at the initial stage of sputtering, the redistribution of ion fluxes between the elements, and the effects related to the mass transfer in plasma and the implantation of sputtered atoms into the mosaic elements of the different variety.     

Insulin and insulin-like growth factor I stimulate the proliferation of human ovarian theca-interstitial cells

PURPOSE: We analyzed familial renal oncocytoma to provide a foundation for studies aimed at defining genes involved in the pathogenesis of renal oncocytoma. MATERIALS AND METHODS: We describe 5 families with multiple members affected with renal oncocytoma. Tumors were analyzed pathologically, and affected and nonaffected members were screened clinically and genetically. RESULTS: We identified 12 affected male and 3 affected female (ratio 4:1) individuals in the 5 families. In affected family members renal oncocytomas were often multiple and bilateral. No metastatic disease was observed. Most renal oncocytomas were detected incidentally in asymptomatic individuals or during screening of asymptomatic members of renal oncocytoma families. One identical twin pair was affected with bilateral multiple renal oncocytomas. CONCLUSIONS: Renal oncocytoma may be inherited in some families.     

Distribution of natural radionuclides throughout intermediate products from chlorination of loparite concentrate

Distribution of radionuclides throughout intermediate products and wastes from high-temperature chlorination of loparite concentrate is studied by γ-ray spectrometry. The major fraction (about 80%) of natural radionuclides remains in the REE chloride melt, the residual activity being distributed between the salt trickling filter (STF) melt and crude niobium and tantalum chlorides. Thorium and uranium chlorides sublime and are concentrated in spent STF melt, whereas the radium chlorides remain essentially in the REE melt. However, a remarkable amount of radium (²²⁸Ra and ²²⁶Ra) is found in spent STF melt, which should be taken into account in developing and introducing an advanced process for treatment and deactivation of the salt solutions formed in hydrowashing of STF melt.     

The epigenetic impact of weaning on craniofacial morphology during growth

Miniature pigs (Sus scrofa) were used as a model to investigate whether the time of weaning (a nongenetic factor) affects skeletal growth rates for both pre- and postweaning time periods. Control litters were weaned at the normal time of 32 days. Two litters were weaned early (at 20 days) and two late (at 46 days). We digitized cranial landmarks from radiographs taken three times a week for a total of 70 days. We used analysis of covariance to test for differences in growth rates between pre- and post-weaning periods, as well as differences in growth rates among treatments. In both the late weaned pigs and the controls, facial length, facial width, basicranial length, and basicranial width growth rates slowed significantly at the time of weaning. However, in the early weaned pigs, there were no significant changes in growth rates for any of the facial or basicranial measurements at weaning. Furthermore, the postweaning rates of growth were different among treatments. One possible implication is that early growth rates could be under tight genetic control while later growth rates can be epigenetically regulated through nutritional changes.