Biomedical subjects

R H Xu

Publications and source records attributed to R H Xu.

43 records · Page 3Linked to original sources

PubMed1990

[A preliminary report on endemic fluorosis caused by treating food with hot spring water].

Fengliang town is situated in the hot spring area in the eastern part of Guangdong province. The concentrations of fluorine in drinking water were less than 0.4 ppm and the prevalence rate of dental fluorosis was 55.43%. A preliminary epidemiological survey showed that the fluorine concentrations of vegetables treated with hot-spring water (F- 20.33 ppm) and dried and those with control water (0.12 ppm) were 55.35 and 16.29 mg/kg respectively. The former was significantly higher than the latter. There was a positive correlation between the dental fluorosis prevalence rate and the distance from residential site to the hot spring in five residential sites and a dose response relationship between prevalence rate and frequency of using hot spring water was observed. It is suggested that the major epidemiological factor of fluorosis in this town is the food contaminated by hot spring water and this area could be designated as an endemic fluorosis area due to food contamination by hot-spring water.

Adolescent↗

PubMed1989

The effect of intrauterine devices, the stainless steel ring, the copper T220, and releasing levonorgestrel, on the bleeding profile and the morphological structure of the human endometrium--a comparative study of three IUDs. A morphometric study of 96 cases.

Thirty-four women using the stainless steel ring (SS), 43 women using the Copper T220 (TCu), and 19 women using levonorgestrel-releasing intrauterine devices (LNG) were admitted to the study. The light microscopic biopsy material was subjected to morphometric studies including 8 indices of endometrial activity before (Control) and after 24 months of exposure to the SS and TCu device and 3-10 months of exposure to the LNG device. The women were grouped into subjects with and without intermenstrual and prolonged bleeding. The results revealed that there were highly significant differences between the IUDs at the endometrial level as displayed by morphometry. However, the difference between bleeders and non-bleeders was not significant in any of the three types of IUDs. Although the mode of action of these IUDs at the endometrial level is different, the mechanism responsible for the irregular endometrial bleeding needs to be further investigated.

Adult↗

PubMed1989

The effect of intrauterine devices (stainless steel ring, copper-T220 and levonorgestrel) on the DNA content in isolated human endometrial cells.

The effect of three different intrauterine devices on the DNA content in human endometrial cells has been studied in 29 women before and after the insertion of an IUD; a stainless steel ring (9 subjects), Copper-T220 (11 subjects) and a medicated IUD releasing levonorgestrel at a rate of 2 micrograms/day (9 subjects). The material was grouped into "bleeders" (having more than 8 days of bleeding and spotting per month) and "non-bleeders" (having less than 8 days of bleeding and spotting per month). The DNA content was assessed on isolated endometrial cells smeared from thin biopsies and the amount of DNA per cell nucleus was measured by means of a Feulgen microspectrophotometric method. No significant difference was found between the "bleeders" and the "non-bleeders" as to the DNA content. Nevertheless, when the total number of subjects were pooled together, a significant increase in the DNA content was found in the post-insertion specimens in the groups of women using the SS and the T-Cu IUDs. Furthermore, a significant decrease in the DNA content was also found when the specimens obtained after the insertion of the LNG IUD were compared with those obtained after 24 months' use of the stainless steel ring and the Copper-T220 device (p less than 0.01 and p less than 0.002, respectively). It is concluded that the insertion of an inert IUD or an T-Cu IUD, induces significant alterations in the DNA content of the human endometrium adjacent to the device, whereas the use of the LNG device does not significantly modify the DNA synthesis when used for 3-10 months. No correlation was found between the DNA content per cell and the number of days of bleeding and spotting.

Adult↗

PubMed1988