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Biomedical subjects

S Lloyd

Publications and source records attributed to S Lloyd.

At least 181 records · Page 10Linked to original sources
PubMed1978

The role of IgA immunoglobulins in the passive transfer of protection to Taenia taeniaeformis in the mouse.

Normal mice were protected against infection with metacestodes of Taenia taeniaeformis when administered intestinal, colostral or serum immunoglobulins obtained from adult mice previously orally infected with the parasitie. The protective capacity of these preparations was found to be associated mainly with IgA of colostrum and intestinal secretions and IgG of serum. The removal of IgA and IgG from immune colostrum and serum, respectively, abolished the protective effect. Neonatal mice were protected against infection with T. taeniaeformis when fed purified colostral IgA and serum IgG from immune donors. The intraduodenal injection of intestinal IgA from immune donors into 4-week-old mice passively protected the recipients against infection with T. taeniaeformis, but intestinal IgG from immune donors had no protective effect when given in this manner. The protective capacity of IgA and IgG was largely eliminated by prior absorption with T. taeniaeformis antigen or hatched, activated oncospheres of T. taeniaeformis.

Animals↗
PubMed1978

Survey of parasites in dairy goats.

The survey was performed to study prevalence and intensity of parasitic infection in goats. Fecal samples were examined from 336 goats in southeastern Pennsylvania and northern Maryland. On the basis of fecal egg, oocyst, and larval counts, the following results were obtained. Eimerian oocysts were found in 100% of the fecal samples and the greatest fecal oocyst counts were found in goats under 6 months of age. Strongyle eggs and Strongyloides eggs were present in 76% and 20%, respectively, of the samples. Moniezia eggs were found in 9%, Trichuris eggs in 4%, and Nematodirus eggs in 1% of the samples. Twenty of 24 flocks examined for Muellerius capillaris were infected with this parasite. In these 20 flocks, 83% of the goats examined were infected with the parasite. Skrjabinema caprae infections were found.

Animals↗
PubMed1978

Survey for infection with Onchocerca cervicalis in horses in eastern United States.

This survey was performed to study the prevalence of infection with Onchocerca cervicalis in horses in the eastern United States. In the course of the survey, 121 horses, 1 mule and 1 donkey were examined. Microfilariae were recovered from 74 (61%) of the horses examined. All infected horses showed microfilariae of O cervicalis in the umbilical sample, 62 (84%) were infected in the eyelid and, in 36 (49%), microfilariae had invaded the eye. The mule was unifected and the donkey was infected with O cervicalis.

Animals↗
PubMed1976

A search for the factors responsible for absence of recovery of the normal vascular response to oxytocin following sympathetic nerve injury.

In dogs following crush injury to the lumbar sympathetic trunk, reflex vasoconstriction reappears in 4-6 months but the normal vasodilator response to oxytocin does not return even 12 months after crush. Histochemical examination of the walls of the blood vessels shows that division or crush of the lumbar sympathetic trunk or removal of terminal ganglia leads to decentralization, not denervation of the blood vessels. True denervation follows division or crush of the sciatic and femoral nerves. Following recovery from sciatic or femoral crush the pattern of peripheral innervation appears histochemically normal. However, there is no return of the normal vasodilator response to oxytocin. It is concluded that a normal response to oxytocin does not return even after long-term recovery from sympathetic injury, nor does its effect depend on a normal pattern of peripheral adrenergic innervation, but on an unknown more central activity of the sympathetic nervous system.

Animals↗
PubMed1975

An investigation of space and space-time clustering in a large sample of infants with neural tube defects born in Cardiff.

Altogether 406 infants with neural tube defects born in Cardiff between 1956-71 were investigated for evidence of space-time clustering and 100 similarly affected infants, together with matched controls born in Cardiff between 1964-66 were investigated for evidence of spatial clustering. No evidence of excessive prevalence in either dimension was observed.

Anencephaly↗
PubMed1973

Area differences in spontaneous abortion rates in South Wales and their relation to neural tube defect incidence.

Data are presented from the South Wales Congenital Malformation Survey (92,982 births 1964-6 inclusive) showing that within areas in South Wales there exists an inverse relation between previous spontaneous abortion rate and the prevalence at birth of neural tube defect (anencephaly or spina bifida cystica or both). This relation is independent of social class, parity, and maternal age, and is not likely to be explained by area differences in accuracy of reporting previous spontaneous abortions.On the basis of these findings a hypothesis is advanced which proposes that the incidence of neural tube defects is uniform throughout South Wales and that the present substantial and relatively stable differences in area prevalence are controlled by small area differences in mortality of malformed embryos. This would seem to suggest that factors initiating the malformation are genetic and that any related environmental factors exert their effect on already abnormal fetuses by influencing, in one way or another, their capacity to survive.

Abortion, Spontaneous↗
PubMed1973

Observations on the epidemiology of simple hypospadias.

A descriptive epidemiological study of simple hypospadias-that is, hypospadias without coexisting malformation outside the genital system-in a birth population of 46,927 singleton males and 1,013 twin males showed that the condition was significantly more common (P < 0.001) in uniovular twin males than in either singleton or binovular twin males. Also the temporal distribution of dates of conception had a significant cyclic pattern for each year of the study. Both observations are thought to support the view that gonadotrophin levels at stage 3 sexual organogenesis play an important part in normal masculinization of male external genitalia.

Chorionic Gonadotropin↗