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  • Author: L.-T. Wang x
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Abstract

In order to investigate the association between polymorphisms in genes encoding metabolizing enzymes (CYP1A1-MspI, EC-SOD (extracellular superoxide dismutase), GSTT1, GSTM1, ALDH2), cigarette and alcohol consumption, and the risk of oral squamous cell carcinoma, we conducted a prospective case-control study comprised of 750 individuals with oral squamous cell carcinoma (OSCC) and 750 healthy individuals. Data about smoking and drinking habits were collected along with other demographic and clinical information. Peripheral blood samples were collected for DNA extraction, and polymerase chain reaction (PCR) and PCR-RFLP (restriction fragment length polymorphism) were used to determine genotypes of CYP1A1, EC-SOD, GSTT1, GSTM1, ALDH2. The results showed that smoking and alcohol consumption were significantly more common among patients than controls (p <0.05). There were significant differences in the genotype distribution for each locus between groups, with the CYP1A1 (m2/ m2), EC-SOD (C/G), GSTT1 [–], GSTM1 [–] and ALDH2 (non G/G) genotypes being more common among patients (p <0.05). Furthermore, the majority of patients had at least two or more variant genotypes, while controls had one or no variant genotype (p <0.05). Finally, multiple variant genotypes combined with smoking, drinking, or both smoking and drinking significantly increased the risk of OSCC, with greater increase for heavier smoking/drinking. In brief, genetic polymorphism of CYP1A1, EC-SOD, GSTT1, GSTM1, and ALDH2 and smoking and drinking history are closely associated with susceptibility to OSCC.

The migration of 99Tc in unsaturated Chinese loess under artificial rainfall condition was investigated in situ. Water suckers were buried at different depths under the bottom of an experimental pit of 2 m × 2 m × 1 m (deep). Quartz containing 3H and 99Tc was introduced into the experimental pit to an area of 40 cm × 40 cm and the pit was backfilled to a thickness of 30 cm. An artificial rainfall of 5 mm/h was applied to the experimental pit 4 h a day for 3 months. Moisture water samples were sucked with the help of a vacuum pumping system and the activity of 3H and 99Tc in the samples was determined. Breakthrough curves of 3H and 99Tc indicated that 99Tc was slightly retarded. The calculated average apparent distribution coefficient of 99Tc in the medium was (1.98±0.42)×10-2 ml/g.

Abstract

Although maternal amniotic and vaginocervical cytokines are known to play a role in triggering preterm delivery, the effects of activating fetal phagocytes and platelets are not clear. In an attempt to clarify this issue, we measured levels of myeloperoxidase (MPO), a phagocyte activation marker, and soluble p-selectin (sCD62p), a platelet activation marker, in umbilical cord blood samples from 2200 consecutive cord blood collections, 106 of which were from preterm infants. MPO and sCD62p levels were correlated to gestational age and preterm delivery. It was found that MPO levels were significantly higher in preterm infants and were not significantly correlated to gestational age. In contrast, sCD62p levels were lower in preterm infants and were negatively correlated to gestational age. In summary, we showed that fetal phagocyte activation as demonstrated by higher cord blood MPO levels is associated with preterm delivery, but platelet activation as shown by lower sCD62p levels is not. This suggests that fetal phagocyte activation may be implicated in preterm delivery, and subsequently in prematurity related inflammatory insults.

The diffusion of 99Tc in granite was investigated with small-sized diffusion cells, composed of a radioactive source solution cell and a sampling cell. Water in the two cells was kept at the same level. 1 ml aliquots were taken from the sampling cells daily during the first 50 days, then at intervals of several days, and measured via liquid scintillation counting. The experimental results indicate that the diffusion of 99Tc and 3H in granite follows the one-dimensional diffusion equation when diffusion time is long enough (>100 days). The calculated average diffusion coefficient of 99Tc (1.4×10-12 m2/s) is about one half of that of 3H (3.2×10-12 m2/s).