Diagnostics for the tropical countries.
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Amebiasis↗
Biomedical subjects
G P Talwar
Publications and source records attributed to G P Talwar.
Necrosis and inhibition of growth of human lung tumor by anti-alpha-human chorionic gonadotropin antibody.
Human lung tumor cells (ChaGo) established in culture from a bronchogenic squamous cell carcinoma synthesize and secrete large amounts of human chorionic gonadotropin (HCG), predominantly the alpha subunit of the glycoprotein hormone. ChaGo cells lose their transformation phenotypes following treatment with anti-alpha-HCG antibody or following inhibition of intracellular synthesis of alpha-HCG by the anti-sense RNA technique. We report that tumors induced by ChaGo cells in female athymic mice undergo necrotic degeneration following local or intraperitoneal administration of alpha-HCG-specific-antibody. The alpha-HCG antibody did not affect the growth of tumor induced by alpha-HCG nonproducing human tumor cells. Histopathological examinations of the anti-alpha-HCG antibody-treated tumor tissues showed active necrosis. When the antibody treatment was discontinued, the tumorigenesis process resumed. When anti-alpha-HCG antibody was administered simultaneously with ChaGo cells, a concentration-dependent inhibition of tumor growth in athymic mice was completely prevented at higher concentrations of the specific antibody.
Animals↗
Association of HLA antigens with differential responsiveness to Mycobacterium w vaccine in multibacillary leprosy patients.
Leprosy patients undergoing phase II trials in two hospitals of New Delhi, India, were HLA typed to see the association of HLA with differential responsiveness to Mycobacterium w vaccine. The vaccine comprises an atypical, nonpathogenic mycobacterium, Mycobacterium w, which has cross-reactive antigens with M. leprae. Multibacillary patients who are lepromin negative are vaccinated at an interval of 3 months. Considerable improvement is evident in the patients in terms of a decline in bacterial indices and histopathological and immunological upgrading. But all the patients do not respond to the vaccine in the same manner; some are slow responders, while others are good responders. HLA-A28 and DQw3 (DQw8 + 9) were found to be associated with slow responsiveness, while DQw1 and DQw7 were found to be associated with a more rapid responsiveness to the M. w vaccine. However, these associations were not significant after P correction for the number of antigens tested for each locus except for HLA-DQw3 (DQw8 and DQw9) and DQw7. DQw7, a new defined split of HLA-DQw3, seems to be associated with the responsiveness to M. w vaccine.
Cross Reactions↗
Effect of active immunization to luteinizing-hormone-releasing hormone on the fertility and histoarchitecture of the reproductive organs of male rat.
The feasibility of using a vaccine against luteinizing-hormone-releasing factor for suppression of pituitary and gonadal functions has been indicated for some time. Antibody production against this low-molecular-weight, naturally occurring decapeptide, however, requires to be coupled to a carrier protein to enhance its immunogenicity. LHRH was coupled to diphtheria toxoid (DT). Adult male Sprague-Dawley rats with a mean basal body weight of 200 g were immunized with anti-LHRH-DT (20 micrograms/injection/rat) at four-week intervals. An equal number of unexposed animals served as controls. Six animals were killed every two weeks up the end of the week 43. The vaccination schedule did not have any effect on the gain in body weight, nor was any adverse effect of vaccination observed in the course of the investigations. The pituitary, prostate, epididymis, testes, seminal vesicles, adrenal and thyroid were excised for determination of organ weight and histological examination. The adrenal, pituitary and thyroid showed no remarkable weight changes during the observation period, whereas the weights of the reproductive organs demonstrated significant reductions compared to those of the control group. The histopathology revealed marked to significant changes in the gonads and the accessory sex organs including the prostate. A progressive phase of regeneration of spermatogenesis was evident 98 days after vaccination. Total recovery of spermatogenesis was observed 300 days after vaccination. The mating studies showed the return of fertility 300 days after vaccination. The litters borne were normal. Prostate showed recovery after 154 days of vaccination. Our observations lend strong support to the hypothesis that anti-LHRH vaccine can be effectively used on the management of prostate carcinoma. If the vaccination is given together with a suitable dose of long-acting androgen, contained in an adequate delivery system, the regimen may be used for the regulation of male fertility.
Animals↗
An epidemic of non-A, non-B hepatitis in south Delhi: epidemiological studies and transmission of the disease to rhesus monkeys.
In November 1987 an epidemic of NANB-hepatitis broke out in a residential colony of South Delhi which lasted for nearly two months. The epidemic was caused due to the sewage contamination of the drinking water supply. Analysis of the epidemiological data showed that the disease was more common in the younger age group of 11-20 years and that both sexes were equally prone to the disease. The disease could be transmitted to rhesus monkeys by intravenous inoculation of the stool extracts from the patients. Experimentally infected monkeys showed elevated levels of serum aminotransferases and excreted the infectious agent in the stools. Hepatic lesions characteristic of enteric non-A, non-B hepatitis were observed in an infected monkey.
Adolescent↗
Biological actions of monoclonal antibodies to bovine lutropin receptor.
Monoclonal antibodies (Mabs) were produced against bovine Lutropin receptor (LH-R). Antibodies were detected by an enzyme linked immunosorbant assay (ELISA). Hybridomas were subcloned to achieve monoclonality. Ascites were developed in Balb/c mice. Hybridoma supernatants were purified by ammonium sulfate precipitation and chromatography on hydroxylapatite columns. LH-R antibodies showed upto 50% inhibition of 125I-labeled hCG binding to bovine luteal cell membranes and up to 80% inhibition of testosterone production by hCG stimulated mouse Leydig cells. LH-R antibodies were predominantly IgM isotype. Purified antibodies showed a 78-kDa band, in SDS-PAGE, as the heavy chain of the immunoglobulin. LH-R antibodies were localized specifically in the thecal and luteal cells of the rat ovaries as well as in the Leydig cell of mouse testes. Injections of the LH-R antibody caused a constant estrus in normal rats. One month after the cessation of the injections the animals returned to normal estrus cycle and fertility. Pregnant mice injected with LH-R antibodies produced only 3 viable pregnancies and 10 pups, as compared to 8 pregnancies and 45 pups born to normal controls. LH-R antibodies also caused, approximately, a 50% reduction in testosterone production in normal male rats. These observations indicate a high degree of specificity of the Mab to LH-R and their potential in studies on gonadal function.
Animals↗
Active immunization of baboons (Papio anubis) with the bovine LH receptor.
Four baboons (Papio anubis) were actively immunized with bovine LH receptor for periods of 6-22 months. Serum antibody levels were measured by an enzyme immunoabsorbant assay (ELISA). Antibodies against the receptor were detected 2 weeks after the first injection. Antisera caused an inhibition in the binding of human chorionic gonadotropin (hCG) to its receptor as well as inhibited the production of hCG induced testosterone by rat Leydig cells in culture. Serum estradiol and progesterone levels were determined by radioimmunoassay (RIA). Progesterone levels were suppressed during the post immunization period. Two baboons experienced periods of anovulation. Serum estradiol levels were cyclic and appeared elevated. Baboons were mated with males of proven fertility; none of the immunized females conceived over eight cycles of observation. Fertility parameters returned to normal, when antibodies against LH-receptor were undetectable in the serum.
Animals↗
Immunomodulatory effects of neem (Azadirachta indica) oil.
Immunomodulatory effects of neem oil were studied in mice. The animals were treated intraperitoneally (i.p.) with neem oil; control animals received the emulsifying agent with or without peanut oil. Peritoneal lavage, collected on subsequent days, showed a maximum number of leukocytic cells on day 3 following treatment with neem oil; peritoneal macrophages exhibited enhanced phagocytic activity and expression of MHC class-II antigens. Neem oil treatment also induced the production of gamma interferon. Spleen cells of neem oil-treated animals showed a significantly higher lymphocyte proliferative response to in vitro challenge with Con A or tetanus toxoid (TT) than that of the controls. Pre-treatment with neem oil, however, did not augment the anti-TT antibody response. The results of this study indicate that neem oil acts as a non-specific immunostimulant and that it selectively activates the cell-mediated immune (CMI) mechanisms to elicit an enhanced response to subsequent mitogenic or antigenic challenge.
Adjuvants, Immunologic↗
Vaccines for control of fertility and hormone dependent cancers.
Two vaccines, namely one inducing antibodies against hCG and the other against GnRH, are now in clinical trials. The hCG vaccine has entered Phase II clinical trials in three centres in India after successfully completing Phase I clinical studies in several centres in India and in four countries abroad. The vaccine was found to be devoid of side-effects; its effect was reversible. The available data on 179 cycles indicate that the vaccine prevents pregnancy at antibody titres above 50 ng/ml. A genetically engineered version of the vaccine has also been approved for trials in human lung cancer patients of the type which make hCG. hCG is observed to be a growth factor for such tumours. The GnRH vaccine is usable in both males and females as the deca-peptide is common to both sexes. Following suitable experimental and toxicology studies, the vaccine is currently in Phase I/Phase II clinical trials in patients of prostate carcinoma. Where antibody GnRH antibodies were induced, the LH, FSH and testosterone levels declined. This was accompanied by a reduction in prostate specific antigen. Clinical improvement was observed in many cases. The vaccine has also entered Phase I clinical studies in postpartum women, with the objective to extend the lactational amenorrhoea and extend inter-child interval.
Chorionic Gonadotropin↗
Vaccines against fertility.
The first evidence for the efficacy of a birth control vaccine in humans is now available from the Phase II trials on the human chorionic gonadotrophin vaccine in India. Several sperm antigens have been identified as potential contraceptive immunogens and zona pellucida antigens have been reported that reversibly control fertility.
Chorionic Gonadotropin↗
Rapid antibody capture assay for detection of group-A streptococci using monoclonal antibody and colloidal gold-monospecific polyvalent antibody conjugate.
A rapid one step, sensitive and specific antibody capture assay for detection of group-A streptococci from the throat swabs of children is described. Monoclonal antibody either MA-106 or MA-107 specific for group-A streptococci polysaccharide (APS) was used as the capture antibody on nitrocellulose paper and rabbit monospecific polyvalent antibody conjugated with colloidal gold to detect the presence of antigen. The lower detection limit of this assay is 15.6ng APS/ml. The assay is specific for APS and failed to recognize polysaccharides obtained from group-B,-C,-G streptococci as well as Staphylococcus aureus. Antigen extracted from throat swabs of children who were positive for beta-hemolytic plaques (other than group-A streptococci) as seen on blood agar culture gave negative readings, thereby confirming the specificity of the assay for APS.
Adolescent↗
A single human monoclonal antibody that confers total protection from tetanus.
Protective human monoclonal antibodies (HuMAbs) are superior to hyperimmune sera and murine monoclonal antibodies as far as human immunotherapy is concerned. In this report, we describe the successful generation of triomas secreting HuMAbs to tetanus toxin (tt). Lymphoblastoid cell lines secreting anti-tt antibodies were stabilized by back-fusion with a mouse x human heterohybrid myeloma partner, SBC-H20. One of the antibodies so produced, confers total protection of mice from tetanus, unlike a few recent reports where only partial protection (delay in the onset of tetanus) was achieved with single HuMAbs. Experiments to localize the neutralizing epitope(s) of the toxin using the protective monoclonal antibodies revealed that the antibody recognizes a conformational determinant that is destroyed on SDS-treatment. Preliminary studies show that Fab preparations of the protective antibody are capable of neutralizing tetanus toxin, suggesting that it might be possible to clone and express the Fab in a stable vector for large scale production.
Animals↗
Anti-hCG vaccines are in clinical trials.
Two vaccines inducing antibodies against human chorionic gonadotropin (hCG) have completed Phase I clinical trials, indicating the reversibility and safety of these vaccines. One is currently in Phase II efficacy trials in women in three major centres in India. The available data suggest that the vaccine prevents pregnancy above antibody titres of 50 ng/ml hCG bioneutralization capacity.
Antibodies↗
In vitro characterization of T cells from Mycobacterium w-vaccinated mice.
Tuberculosis caused by the intracellular bacterial pathogen Mycobacterium tuberculosis still represents a major health problem, and its effective control would best be accomplished by active vaccination. Although vaccination with M. bovis BCG has proven highly effective in certain parts of the world, in several developing countries it has been found to confer only marginal protection. Hence, novel vaccination strategies are warranted. Mycobacterium w is a saprophytic cultivable mycobacterium which shares several antigens with M. tuberculosis. In the murine system, vaccination with killed M. w was found to protect against subsequent tuberculosis. In order to characterize the responsible immune mechanisms more precisely, mice were vaccinated with killed M. w and T cells restimulated in vitro with mycobacterial antigens. These T cells produced interleukin 2 and gamma interferon but no detectable interleukin 4 and interleukin 5. Killed M. w induced significantly stronger T-cell responses than killed M. tuberculosis, and both vaccination regimes were markedly improved by administration in a mild adjuvant, i.e., the Ribi adjuvant containing trehalose dimycolate, monophosphoryl lipid A, and mycobacterial cell wall skeleton. Our data suggest that M. w-induced immunity against M. tuberculosis rests primarily on TH1 cells, which are thought to be of major relevance for acquired antituberculosis resistance. Our study therefore provides a further step toward the identification of a novel tuberculosis vaccine.
Animals↗
In vitro maturation, fertilization and development of follicular oocytes from buffalo (Bubalus bubalis).
Cumulus-oocyte complexes, 5596, were cultured for 24 h in either TCM-199 or Ham's F-10 with or without gonadotrophins and supplemented with either 20% buffalo oestrous serum (BES) or fetal calf serum (FCS). The maturation rates of oocytes cultured in TCM-199 or Ham's F-10 medium supplemented with 20% BES were 47.4 +/- 17.8 and 44.8 +/- 25.6, respectively. Addition of luteinizing hormone (LH) (5 micrograms ml-1) significantly improved the maturation rate in the Ham's F-10 medium supplemented with 20% BES (76.8 +/- 18.3), but follicle-stimulating hormone (FSH) (0.5 micrograms ml-1) and oestradiol (1 microgram ml-1) failed to synergize with LH (71.7 +/- 19.5). In the TCM-199 system, LH failed to enhance the maturation rate but the addition of FSH and oestradiol significantly enhanced the proportion of mature oocytes (42.7 +/- 1.4 and 81.7 +/- 14.5, respectively; P less than 0.05). Frozen-thawed spermatozoa prepared in Bracket and Oliphant (BO) medium and treated with 5 mmol caffeine 1(-1) + 10 micrograms heparin showed a higher fertilization rate (29.8%) than those treated in Hepes-Talp and treated with 10 micrograms heparin ml-1 (19.6%). Fertilization rate was significantly improved when fresh ejaculated spermatozoa treated with 5 mmol caffeine 1-1 and 10 micrograms heparin in BO medium (50%) was used. Rate of cleavage and development were also higher when in vitro fertilization was carried out with fresh ejaculated spermatozoa treated with caffeine and heparin (34.1 and 36.8%, respectively) than with frozen-thawed spermatozoa (27.0 and 22.0%, respectively). Development rate was enhanced when fertilized ova were cultured in ligated rabbit oviduct (28.0%) than when co-cultured on oviductal cell monolayers (8.2%). The results indicate that oocytes cultured in medium supplemented with BES and gonadotrophins reveal high rates of maturation and development to the blastocyst stage after fertilization with fresh ejaculated spermatozoa.
Animals↗
Characteristics of monoclonal antibodies against porcine zona pellucida-3 and their functional relevance.
Seven monoclonal antibodies (MAs) against 55 kDa glycoprotein family of porcine zona pellucida (ZP3) reacting with either ZP3 alpha (MA-7, MA-27, MA-28) or ZP3 beta (MA-1, MA-2, MA-11, MA-30) have been described. MA-1, -2, -27, -28 and -30 do not recognize carbohydrate determinants as shown by their reactivity to the deglycosylated (DG) ZP3 alpha and ZP3 beta. Indirect immunoperoxidase studies showed that all MAs reacted with zona pellucida from porcine and monkey ovaries. Only MA-1 and -27 reacted with ZP from rabbit ovary as well, while none of the MAs recognised mouse ZP, MA-7, -11, -27, -28 and -30 inhibited in vitro, the zona lysis by trypsin as well as the binding of ZP3 to sperm membrane vesicle as investigated by ELISA.
Animals↗
Amphiphilic and hydrophilic domains of human sperm membrane antigens recognized by immunoinfertile sera.
Selected sera from married couples with immunological infertility were used to identify antigens on hydrophilic and amphiphilic domains of human sperm membrane. Out of eight sera, six recognized proteins from the hydrophilic as well as amphiphilic regions of the sperm membrane. Sera were either reactive to acrosome or to equator and tail of human sperms in indirect immunofluorescence assay.
Acrosome↗
Vaccines for control of fertility.
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Antibody Formation↗