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Biomedical subjects

A Tandon

Publications and source records attributed to A Tandon.

At least 55 records · Page 3Linked to original sources
PubMed1984

Effects on pregnancy in mice of passive immunization against ovine LH and human chorionic gonadotrophin.

Mice given daily i.p. injections of immunoglobulins against ovine LH on Days 3-7 of pregnancy were devoid of implantation sites on Day 8 whereas mice treated with antibodies to hCG had embryos of normal number and appearance on Day 8. These antibody treatments reduced the mean +/- s.d. serum progesterone concentrations from 65.4 +/- 15.3 ng/ml (control globulins) to 8.6 +/- 4.9 ng/ml (anti-LH) and 9.2 +/- 3.1 ng/ml (anti-hCG) on Day 8 and had no differential effect on serum oestrogen levels on Day 4. However, the mice treated with anti-hCG did not litter; resorption of the embryos took place between Days 10 and 14 of pregnancy. Indirect immunofluorescence and quantitative immunoenzymic assays showed the presence of anti-ovine LH and anti-hCG reacting antigens in the mouse feto-placental unit. On Day 6, the values of reacting antigens (mean +/- s.d. absorbance units/10 micron section of embryo) were 0.050 +/- 0.002 with control globulins, 0.059 +/- 0.002 with anti-hCG-Ig and 0.196 +/- 0.018 with anti-LH-Ig; the corresponding values on Day 12 were 0.075 +/- 0.009, 0.402 +/- 0.02 and 0.416 +/- 0.015. The quantitative disposition of the reacting antigens to the two types of anti-gonadotrophins seems to bear a temporal relationship to their respective antifertility action. The pregnancy terminating action of immunoglobulins to ovine LH (Days 6, 7 & 8) and hCG (Days 8, 9 & 10) was counteracted by administration of 2 mg medroxyprogesterone acetate on Days 6, 9 and 12, indicating the importance of progesterone in the maintenance of pregnancy in the mouse.

Animals↗
PubMed1983

Time courses of antibody levels in Mastomys natalensis after infections with Litomosoides carinii, Dipetalonema viteae, Brugia malayi or B. pahangi, Determined by ELISA.

Using a Litomosoides carinii adult antigen, time courses of antibody levels were followed by an ELISA in L. carinii, Dipetalonema viteae, Brugia malayi and B. pahangi infected Mastomys natalensis. Using various groups of infected animals, periods up to 400 days after infection were covered. In L. carinii infected Mastomys, antibodies were first detected 11 days p.i. and levels increased rapidly until day 40. Temporarily reduced levels about the beginning of patency were followed by increasing values until about 100 days p.i. Then the antibody content of the sera remained more or less constant until about 250 days p.i. although maximum levels were found at day 170. Thereafter, the antibody concentration in the sera declined slowly but high levels were still observed 390 days p.i. The antibody content was usually higher in animals with high microfilariae densities than in those with low microfilariae counts but relations could not be proven statistically. In D. viteae infected Mastomys, maximum antibody values were reached within the beginning of patency. Levels were not altered markedly until about 110 days p.i. Thereafter they decreased slightly but then remained constant until the end of the investigation period 350 days p.i. B. malayi infected animals showed a rapid increase of the antibody content in the sera; a maximum was reached by 20 days after the infection. Thereafter, somewhat constant levels were found for 4--5 months. After 300 days p.i. the antibody levels declined progressively, accompanied with increasing parasitaemia densities; after 380 days the levels reached about 2/3 of the maximum. However, despite this, no relation was found between the levels of parasitaemia and antibody in individual animals. In B. pahangi infections the main prepatent antibody increase occurred during week 5 p.i., when maximum values were observed. The beginning of patency and the early patency were accompanied with slightly declining antibody levels. From 150 days p.i. until the end of the investigation 400 days p.i., the antibody content of the sera was fairly constant.

Animals↗
PubMed1983

Immunodiagnosis of Bancroftian filariasis by enzyme linked immunosorbent assay using Litomosoides carinii and Setaria cervi antigens.

An ELISA was developed using cross-reacting antigens of Litomosoides carinii and Setaria cervi to detect antibodies in filarial patients. The diagnostic potential of the test was investigated in 80 symptomatic cases of filariasis, 40 asymptomatic carriers and 50 normal subjects of an area around Lucknow endemic for Bancroftian filariasis. By the criteria laid down for ELISA positivity for filariasis, 86.2% of the symptomatic cases could be detected by this test. Only four of 40 asymptomatic carriers and one of 50 normal subjects gave a positive ELISA response. Purified antigenic fractions of S. cervi are also promising for detecting asymptomatic carriers.

Antibodies↗
PubMed1983

Steroid metabolism by rabbit embryos: time of onset of steroidogenic activity.

Twenty four hour incubations of the days 5 and 6 pre-implantation and the days 7 and 8 post-implantation rabbit embryos were carried out in the presence of 3H-labelled steroid substrates viz. dehydroepiandrosterone (DHEA), androstenedione (Ad) and testosterone (Te). While both the pre- as well as the post-implantation embryos were able to actively metabolize the various neutral steroid substrates into other neutral, mostly 5 alpha-reduced, steroid metabolites, the conversion of DHEA to Ad or that of DHEA, Ad and Te to estrogens was exhibited only by the days 7 and 8 post-implantation embryos. The findings suggest that pre-implantation blastocysts of rabbit lack the potentiality to synthesize steroids and acquire this ability only after implantation.

Androstenedione↗
PubMed1981

Efficacy of antibodies generated by Pr-beta-hCG-TT to terminate pregnancy in baboons: its reversibility and rescue by medroxyprogesterone acetate.

Antibodies produced by the vaccine Pr-beta-hCG-TT in monkeys were effective in terminating pregnancy in baboons on passive administration. The animals returned to cyclicity soon after the onset of vaginal bleeding. Fertility was regained. Globulins from non-immunized control monkeys in amounts, volume and injection schedule similar to those employed for passive termination did not intercept pregnancy. The abortifacient action of anti-CG antibodies could be counteracted by administration of medroxyprogesterone acetate.

Abortion, Induced↗
PubMed1981

Use of enzyme linked immunosorbent assay in intestinal and extra-intestinal amoebiasis (amoebic liver abscess).

The sera of patients with amoebic liver abscess, intestinal amoebiasis and non-specific hepatomegaly were examined for the presence of antibodies to Entamoeba histolytica antigen by enzyme linked immunosorbent assay (ELISA). All the amoebic liver abscess sera were strongly positive. The test was also positive in all the proved cases of intestinal amoebiasis but the ELISA values were relatively slightly lower. Nine of 10 cases of non-specific hepatomegaly with stools negative for E. histolytica gave positive results with ELISA. The IHA titre in all but one of the non-specific hepatomegaly cases was within normal value.

Antibodies↗