Distribution and characteristics of placental ANP receptors in normal and hypertensive pregnancy.

The ANP (atrial natriuretic peptide) receptor binding site was studied in human placentas of normal and hypertensive pregnancy. The results showed there were specific high affinity ANP receptors in the nonbrush border (fetal side), and their affinity to ANP was higher than that in the microvillous membrane (meternal side). The ANP receptor affinity in the nonbrush border and microvillous membrane of normal pregnancy was higher than that of hypertensive pregnancy. Though the weight of placentas of hypertensive pregnancy was lower than that of normal pregnancy, high ANP concentrations in the placental tissues, umbilical and maternal blood were found in hypertensive pregnancy. It is believed that the distribution of ANP receptors in the placentas is related to hemodynamics, maternal exchange and fluid and electrolyte balance. The decrease of ANP receptors and lowering of affinity in hypertensive pregnancy may influence the the target cell effect of ANP, especially in the fetal side. This may be related to the pathogenesis of hypertensive pregnancy.

Significance of changes in serum superoxide dismutase level in hypertensive syndrome of pregnancy.

The concentration of human serum superoxide dismutase-1 (hSOD-1) containing copper and zinc ions were measured by radioimmunoassay healthy nonpregnant women, 15 normal pregnant women, 15 patients with mild to moderate hypertension (MMHSP) and 15 with severe hypertensive syndrome of pregnancy (SHSP). The mean serum hSOD-1 concentration in nonpregnant women was 148.84 +/- 60.53 (x +/- s) micrograms/L; while in the other 3 groups it was 394.19 +/- 122.21 micrograms/L, 377.12 +/- 173.45 micrograms/L and 581.15 +/- 118.50 micrograms/L. The results suggest that harmful free radicals increase gradually and a strong body defence system against oxidation damage of tissue cells is produced in the course of normal pregnancy and MMHSP. With cardionatrin treatment serum hSOD-1 concentrations of patients ameliorated returned to the level of normal pregnancy. The results indicate that there is a positive correlation between cardionatrin and hSOD-1 levels (r = 0.569, P less than 0.05), and a physiological regulation of the defence system exists, which may be related to the white blood cells. Hence, hSOD-1 probably plays a significant role in defence during normal pregnancy and hypertensive syndrome of pregnancy (HSP).

Assessment of intradermal test in longitudinal surveillance of bancroftian filariasis.

Longitudinal surveillance was carried out consecutively during 1982-1987 in two pilot villages where bancroftian filariasis was prevalent in different severity before 1982. Intradermal test (IT) with filaria polypeptide (FPT) antigen prepared from Dirofilaria immitis was made. It was shown that the level of immediate hypersensitivity reaction to the antigen in population as shown by IT appeared to be directly proportional to both the prevalence of the disease and the infection rate of mosquitoes harbouring larval filariae before mass and selective treatment with diethylcarbamazine. Time for negative conversion of IT after chemotherapy was significantly longer in previous microfilaraemic patients than that in amicrofilaraemic cases. The selected three criteria of IT used in filariasis surveillance, namely, the positive rate, frequency of strong reaction and positive conversion rate, were diminished gradually after chemotherapy year by year, so that the three criteria were demonstrated to be useful for longitudinal surveillance of lymphatic filariasis.

[Assessment of intracutaneous test in longitudinal surveillance for lymphatic filariasis].

In order to evaluate the usefulness of intracutaneous test (IT) in longitudinal surveillance of filariasis, two administrative villages selected from Queshan County, Henan Province of China, endemic for Wuchereria bancrofti, were surveyed in 1982, 1983 and 1987 respectively, by IT with antigen FPT derived from Dirofilaria immitis. The result showed that the original level of IT to antigen FPT in the population was consistent with the data of either etiological or entomological investigation before chemotherapy. When the microfilaraemia rate and natural filarial infection rate of mosquitoes in a village were high, the positive rate and frequency of strong positivity (skin wheel diameter greater than or equal to 1.3 mm) for immediate hypersensitivity reaction would be high too; and the reverse was true. It is suggested that both criteria of IT mentioned above may be useful in assessing endemicity of lymphatic filariasis before mass chemotherapy. The speed of negative conversion of IT in both groups, the previously microfilaraemic patients and the microfilaraemic inhabitants positive to immediate hypersensitivity reaction before chemotherapy, were different, the former being significantly slower than that of the latter after mass and selective chemotherapy with diethylcarbamazine. All of the three criteria for immediate hypersensitivity, positive rate, frequency of strong positivity and positive conversion rate, decreased gradually after a mass and selective DEC treatment. Until 1987, the 5th year after the chemotherapy, the average positive rate in the two villages dropped to 20.0% from 55.4% in 1982, the frequency of strong positivity to 2.8% from 23.8% in 1982, and the positive conversion rate to 9.7% (1984-1987) form 19.2% (1982-1983).(ABSTRACT TRUNCATED AT 250 WORDS)