Evidence of sex variations in microfilaraemia and fluorescent antibody titre level at puberty in a bancroftian filariasis endemic area.

1101 children and young adults between 2 and 17 years age, residing in Bancroftian filariasis endemic area of the Jharia Coalfields in Bihar, were examined by Indirect Immunofluorescent Test (IIFT) against Dipetalonema Vitae. The results, along with those of two night blood surveys conducted in the same area, covering 2148 and 2246 persons respectively, are reported. In the prepubertal age groups there was no statistically significant variation in the percentage of children showing positive antibody titre in either sex, but a sudden fall of more than 50 per cent in the antibody level was observed in females at the onset of puberty. This did not occur in males. Analysis of the night blood results also indicated a remarkable fall in microfilaria rate and density in females at the onset of puberty and a low level was then maintained over the whole of the child bearing age. No such change was observable in males. Sex differences in the susceptibility of the host to helminthic infections is well-known and in animal experiments the effect of sex hormones in modifying such susceptibility has been established. In human filariasis the probable part played by the male and female sex hormones in bringing about abrupt changes in immunoresponse and infection rate at the onset of puberty is discussed.

Lymphatic filariasis in man: demonstration of circulating antigens in Wuchereria bancrofti infection.

Five hundred and twenty-nine sera obtained from people dwelling in an area endemic for bancroftian filariasis were analysed for the presence of soluble circulating antigens (SCA) of filarial origin by counter immunoelectrophoresis and 303 were found positive. It, therefore, appears that 57.3% subjects could be diagnosed by the detection of SCA irrespective of their clinical status. Of the three groups investigated, microfilaraemic, amicrofilaraemic and clinical, SCA could be demonstrated in maximum number of sera obtained from clinical cases. The parasite specificity of the SCA was determined by enzyme linked immunosorbent assay (ELISA), immunofluorescent antibody test (IFAT), counter immunoelectrophoresis (CIEP) and gel diffusion (GD) using antisera raised against Litomosoides carinii in rabbits and antigens derived from Wuchereria bancrofti microfilariae or antigens present in sera of patients with bancroftian filariasis. This anti-carinii hyperimmune serum under study did not show positive reactions with parasites other than filaria, or with the sera obtained from pre-immunized rabbits and non-endemic controls. A demonstration of a distinct precipitin band in CIEP and GD indicates that either monospecific hyperimmune sera or monoclonal antibodies could be raised for the development of a simple method for immunodiagnosis of bancroftian filariasis.

Effects of lithium chloride, desmethylimipramine and cocaine on the cardiovascular actions of ouabain in dogs with or without carotid and aortic baro-receptor reflexes.

The cardiovascular effects of ouabain as modified by LiCl, DMI and cocaine in anesthetized dogs with or without buffer nerves (carotid sinus and vagus nerves) were compared. Ouabain significantly increased the LV dp/dt in saline and cocaine but not in LiCl or DMI treated buffered animals. Significant ouabain-induced increase in MAP and decrease in HR were also observed in animals receiving DMI and cocaine. Neither the AD nor the LD of ouabain was modified by Licl or cocaine. DMI, while reducing the AD could not modify the LD of ouabain. In animals without the baro-reflex mechanism (debuffered), significant increase in both LVP and LV dp/dt were observed with ouabain following LiCl and DMI administration. Debuffering itself reduced the LD ouabain in saline treated animals. It was concluded that depending on the presence or absence of baro-reflex mechanism, lithium and DMI could either inhibit or facilitate the inotropic effect of ouabain. Cocaine did not interfere with the actions of ouabain. Ouabain-induced cardiotoxicites were not greatly modified by any of the drugs used.

[Displacentar transfer of fluorescent antibodies from mothers to their newborns in a Wuchereria bancrofti endemic area in India (author's transl)]. / Der immunfluoreszenz-serologische Nachweis diaplazentar von Mutter auf Kind übertragener Serum-Antikörper gegen D. viteae als antigen in einem Wuchereria bancrofti-Endemiegebiet in Indien

The immunofluorescent antibody test against D. viteae applied to mothers blood and the umbilical cord blood of their newborns showed a very close association of the two endpoint titers in 50 pairs of examinations. In 37 cases the titer of the child was corresponding with the titer of its mother, in 10 cases the newborn's titer was one dilution below, in 2 cases two dilutions below the mother's titer. The titers of newborns of 15 mothers with titers greater than or equal to 1:80 were in 11 cases positive; 11 children of 15 mothers with a titer of less than or equal to 1:40 had a corresponding endpoint titer, in 4 it was below 1:40. There was a formal dependence between age of mothers and titer of mothers and their children. In 20 children reexamination after 6 months showed in no case an endpoint titer of 1:40 or above, regardless, whether previously mother or child had a high titer or not. These results indicate that in a W. bancrofti endemic area material antibodies against filariae, demonstrable in IFT against D. viteae are transferred diaplacentarly to the newborn, which are no more demonstrable after the sixth month of life.

Effects of sound stimulus on gastric secretion and plasma corticosterone level in rats.

The effects of sound stimulus were studied on the gastric secretion in rats with chronically implanted cannulas. Attempts were made to correlate the changes in the secretion with those of the plasma corticosterone level. Exposure of the animals to sound stimulus (1 hr or 2 hr) produced a marked decrease in gastric secretion and a concomitant increase in plasma corticosterone. It appears that in producing these effects sound stimulus acted as a stressor. Furthermore, a paradoxical increase in secretion was noted in the first hour collection prior to the sound stimulus. This initial increase in secretion may be due to an adaptive compensatory mechanism in anticipation of its marked inhibition.

Cardiovascular effects of central microinjections of apomorphin in cats.

Microinjections of apomorphine (25-300 mug) were made into the lateral ventricle, dorsal nucleus of the vagus and ventromedial nucleus of the hypothalamus of cats through a stereotaxically implanted cannula-electrode. Apomorphine caused depressor and bradycardic effects without any dose-response relationship. At the above doses of apomorphine the efferent vagal discharges werr markedly increased concurrent with cardiovascular changes. Respiration was not affected except at higher doses causing depression in some experiments. Pretreatment with atropine, scopolamine or haloperidol abolished those responses. Similar results were observed with bivagotomy and midcollicular transection. Dopamine (125-100 mug), acetylcholine (10-100 mug) and norepinephrine (25-100 mug) caused similar cardiovascular changes, as in the case of apomorphine, and such effects were blocked by both specific and non-specific autonomic blackers. Thus the hypothalamus and the dorsal nucleus of the vagus appear to be inbolved in the central cardiovascular effects of apomorphine and such effects may be mediated through more than one neurotransmitter mechanisms.