[Scanning electron microscopy of adult Trichuris trichiura].

The paper reports the result of the observation on the ultrastructure of the body surface of adult T. trichiura by scanning electron microscopy. Unique features of T. trichiura are described including the presence of labial-shape structures at the periphery of mouth, eight cephalic pores and a pair of amphids around the mouth pore and vesicle-shaped cuticular protuberances on the abdomen of T. trichiura. Cuticular pores were found scattering on the surface of T. trichiura. Detailed descriptions of male copulatory sheath and spicule were presented.

[Scanning electron microscopic observations on the copulatory spicules of the male Necator americanus and Ancylostoma duodenale].

Scanning electron microscopic observations were made on the morphological structures of the two copulatory spicules of the male Necator americanus and Ancylostoma duodenale. In both species, one of the two copulatory spicules was in the shape of a concave groove and the other, in the shape of an oblate tube. Owing to the difference in the concavity of the groove shaped copulatory spicule between the two species as shown by the cross sections, Necator americanus usually appear to have only one copulatory spicule whereas Ancylostoma duodenale usually show two separate copulatory spicules in appearance (Figs 1-10).

[Scanning electron microscopic observations on larvae and young adults of Angiostrongylus cantonensis].

Scanning electron microscopic observations on the structure of the body surface of various larval stages and young adults of Angiostrongylus cantonensis were made. The mouth opening of the first and second stage larvae closes in "Y" form until well developed young adult stage. There are two rows of 6 sensory papillae each around the mouth. With development of the worm, the papillae of the outer row gradually degenerated and could hardly be seen in adult worms. A pair of amphidial pores was present on the external side of lateral papillae of the inner row, being conspicuous in the fourth-stage larvae. There was one excretory pore on the ventral side of the anterior end. The copulatory bursa of the male worms began to develop in the third stage larvae and became well developed in the 25-day young adults. The processes of the development of copulatory bursa were described. The gonopore could be seen in the female worm as early as in the first-stage larvae but the anal pore appeared only in the fourth-stage larvae, both of them did not develop completely until the young adult stage of 11 day old (Figs. 1-18).

Study of lead absorption and its effect on children's development.

Blood lead levels of 180 pupils from two elementary schools were determined and the intellectual development of the children was followed. The children in these two groups were similar in most nonlead variables. Results showed that pupils at the school near a battery plant had higher blood lead levels than those at a school in a residential neighborhood. An evident dose-effect relationship between blood lead level and children's performance on psychological testing existed: the higher the blood level, the lower the intelligence quotient. This relationship remained after confounding factors were controlled by stepwise regression analysis. Partial regression coefficients for PbB and verbal IQ, performance IQ, and full-scale IQ were -0.85, -0.71, and -0.91, respectively.

Serum dehydroepiandrosterone sulphate and pubertal development in Chinese girls.

Serum dehydroepiandrosterone sulphate (DHEAS), estradiol (E2), luteinizing hormone (LH) and follicle stimulating hormone (FSH) were measured by radioimmunoassay in 170 healthy school girls from 7-16 years old. Blood samples from postmenarcheal girls were taken on days 6-10 of the menstrual cycle. Bone age, height, weight, breast and pubic hair development were also investigated. Of the four hormones measured, serum DHEAS displayed the earliest elevation, at 7 years and upwards. A significant DHEAS increment at chronological age 13 years was observed. Girls with earlier menarche had higher DHEAS level than girls having later menarche. Serum DHEAS levels also correlated with bone age, height, weight, subcutaneous fat and pubertal stages. The results suggest that adrenal androgen might be involved in the initiation of puberty and female maturation.