Brugia pahangi: circulating antibodies to adult worm antigens in uninfected progeny of homologously infected female jirds

Serum IgG antibody levels to adult Brugia pahangi antigens were measured in uninfected offspring from uninfected and B. pahangi-infected female jirds. Antibody titers to B. pahangi antigens in sera of offspring from infected females mimicked the maternal titer during the suckling period. Neonate titers peaked at 2 weeks of age at levels as high as 1:4100, then decreased to levels well below maternal titers by 8-12 weeks of age. Concurrent maternal and 2-week-old neonate sera recognized identical B. pahangi antigens in Western blots. Spleen cells from 2-week-old filariae-exposed and unexposed offspring failed to produce measurable antibody to B. pahangi in vitro. Progeny of uninfected mothers nursed by B. pahangi-infected females showed circulating IgG antibody titers to adult worm antigens similar to those of homologously reared offspring. Conversely, offspring born to B. pahangi-infected females and nursed by an uninfected female had no serum antibodies to B. pahangi antigens. Blastogenic responses of spleen cells to the mitogens phytohemagglutinin and pokeweed mitogen, and adult B. pahangi antigens, were not different between offspring groups. Mean areas of pulmonary granulomas induced by the intravenous inoculation of B. pahangi antigen-coated beads also did not differ between 4- and 8-week-old progeny of uninfected or infected females. These results suggest that the circulating IgG antibodies to adult B. pahangi antigens demonstrated in offspring of infected female jirds are maternally derived via the milk and do not alter the cellular responses of uninfected offspring to B. pahangi antigens as measured by antigen-stimulated blastogenesis or pulmonary granulomatous inflammatory response.     

Seroprevalence of Toxoplasmosis in the Residents of Cheorwon-gun, Gangwon-do, Korea

The seroepidemiological status of toxoplasmosis was surveyed among the residents of Cheorwon-gun, Gangwon-do by means of ELISA using a crude extract antigen of Toxoplasma gondii. The sera of 1,661 adult residents (866 males and 795 females) were collected and checked for IgG antibody titers, which showed 17.0% positive rate (282 sera). The positive rate was significantly different between the sex; 20.6% for males and 13.1% for females (P<0.05). The positive rates were higher in fifties of males (28.7%) and forties of females (20.0%). This positive rate of toxoplasmosis in Cheorwon-gun residents is regarded as the highest among the surveys of different geographical regions of Korea. This high positive rate may due in part to peculiar geographical locality of the surveyed area near the naturally well preserved demilitarized zone (DMZ) or presumably consumption of the pork imported from high endemic nations. Therefore, it is necessary to study further the epidemiology of toxoplasmosis in Cheorwon-gun.     

Toxoplasma gondii antibody titers in sera of children admitted to the Seoul National University Children's Hospital

A total of 542 children under 10 years of age, admitted to the Seoul National University Children's Hospital, was examined for antibody titers of Toxoplasma gondii using indirect latex agglutination (ILA) test. Among them, 7.7% showed positive titers higher than 1:32, without significant difference between males (7.3%) and females (8.5%). The seropositive rate increased with age although the statistical significance was negligible (0.05 < P < 0.1). By residential areas, the prevalence appeared higher among children from southern provinces (Kyongsang-do and Cholla do) than those from other areas, but the statistical significance was also very low (0.05 < P < 0.1). When the seropositive cases were analyzed by coincidental diseases, the prevalence was significantly higher in patients with congenital diseases than in patients with non-congenital diseases (P < 0.05). The results showed that the seropositive rate of toxoplasmosis in children examined was not high compared with other endemic countries. Some correlations are suggested between toxoplasmosis and congenital anomalies in Korea.     

Acute visceral toxoplasmosis in captive dik-dik (Madoqua guentheri smithi)

Acute toxoplasmosis was diagnosed in 2 captive dik-dik (Madoqua guentheri smithi) in the Houston Zoo. Both animals became ill suddenly and died in spite of supportive therapy. Toxoplasma gondii was identified in tissues of both animals immunohistochemically, and antibodies to T. gondii were found in titers of 1:800 or more in both animals upon examination by the modified agglutination rest. The cause of death was considered to be toxoplasmic pneumonia. This is the first report of toxoplasmosis in M. g. smithi.     

Detection of juvenile hormone I,II and III in adult monarch butterflies (Danaus plexippus)

Hemolymph of Danaus plexippus (monarch butterfly) was analyzed for juvenile hormone titer by gas liquid chromatography-mass spectrometry (GC-MS) in the selected ion monitoring mode. Laboratory reared, reproductively active, adult males and females contained JH I, II and III. JH II predominated with titers ranging from 2.3 to 11 ng/ml hemolymph. Titers of JH I and JH III were approx. 1 order of magnitude lower than those of JH II. JH I, II and III acids were also detected, but at levels generally lower than the corresponding JHs. JH titers in field collected reproductively inactive, gregarious adult monarchs, were 1–2 orders of magnitude lower than those of laboratory reared reproductively active monarchs. JH II was again the predominant JH in these animals.     

Antigenemia and Specific IgM and IgG Antibody Responses in Rabbits Infected with Toxoplasma gondii

In this experiment, the correlation between antigenemia and specific antibody responses in Toxoplasma gondii-infected rabbits was assessed. We injected 1,000 T. gondii tachyzoites (RH) subcutaneously into 5 rabbits. Parasitemia, circulating antigens, and IgM and IgG antibody titers in blood were tested by ELISA and immunoblot. For detection of parasitemia, mice were injected with blood from rabbits infected with T. gondii and mice died between days 2 and 10 post-infection (PI). Circulating antigens were detected early on day 2 PI, and the titers increased from day 4 PI and peaked on day 12 PI. Anti-Toxoplasma IgM antibody titers increased on day 6 PI and peaked on days 14-16 PI. IgG was detected from day 10 PI, and the titers increased continuously during the experiment. The antigenic protein patterns differed during the infection period, and the number of bands increased with ongoing infection by the immunoblot analysis. These result indicated that Toxoplasma circulating antigens during acute toxoplasmosis are closely related to the presence of parasites in blood. Also, the circulating antigen levels were closely correlated with IgM titers, but not with IgG titers. Therefore, co-detection of circulating antigens with IgM antibodies may improve the reliability of the diagnosis of acute toxoplasmosis.     

Toxoplasma gondii infections in captive black-footed ferrets (Mustela nigripes), 1992-1998: clinical signs, serology, pathology, and prevention

An epizootic of toxoplasmosis occurred among 22 adult and 30 kit black-footed ferrets (Mustela nigripes) maintained under quarantine conditions at the Louisville Zoological Garden (Louisville, Kentucky, USA) in June, 1992. Black-footed ferrets appear to be highly susceptible to acute and chronic toxoplasmosis. Clinical signs were observed in 19 adults and six kits and included anorexia, lethargy, corneal edema, and ataxia. Two adults and six kits died with acute disease. High antibody titers to Toxoplasma gondii were detected by latex agglutination and modified agglutination assay in 10 black-footed ferrets. One adult and six kits that died with acute clinical signs were necropsied and T. gondii-like organisms were found microscopically in multiple organs. Diagnosis of toxoplasmosis was confirmed by immunohistochemical staining with anti-T. gondii antibodies and by ultrastructural examination. Although the source of T. gondii for black-footed ferrets was not identified, frozen uncooked rabbit was the most likely source. Chronic toxoplasmosis resulted in the death of at additional 13 black-footed ferrets that were adults during the epizootic. Affected animals developed chronic progressive posterior weakness and posterior ataxia 6-69 mo after the epizootic began. Meningoencephalitis or meningoencephalomyelitis associated with chronic toxoplasmosis were identified at necropsy in all 13 ferrets. Precautions to prevent introduction of pathogens into the colony were insufficient to exclude T. gondii. Although toxoplasmosis may cause significant mortality in mustelids, the high mortality of black-footed ferrets in this epizootic was of concern due to their endangered status. This is the first detailed report of toxoplasmosis in black-footed ferrets.     

Seroprevalence of <Emphasis Type="Italic">Coxiella burnetii</Emphasis> antibodies among students of the <Emphasis Type="Italic">Faculty of Medicine</Emphasis> in Košice (Slovakia)

Titers of immunoglobulin IgG against phases I and II of Coxiella burnetii were determined in 241 students of the Faculty of Medicine by ELISA method and the respective risk factors were evaluated, e.g., rural and urban life, consumption of milk, contact with animals and gender, which may be associated with exposure to C. burnetii. Phase I antibodies (Abs) were detected in 59 serum samples (24.4 %) at antibody level of 1: 100–1: 400. Phase II Abs were found in 179 persons (74.2 %). The titers were in the range of 1: 100–1: 1600. The titer ≥1: 800 of IgG was used as a cut-off level, and was detected only in 20 students (8.2 %). No significant difference in the prevalence of Abs was detected either between the students living in rural and urban environment (78.8 and 73.2 %, respectively) or between males and females (74.0 and 74.7 %, respectively). Abs were detected more frequently in raw milk consumers (68.1 %) and in students who kept some animals (73.7 %).     

The role of breast milk in protecting urban Peruvian children against cryptosporidiosis.

To test the hypothesis that breast milk of nursing mothers may afford children protection against cryptosporidiosis, a prospective cohort study was carried out in the young peoples' community of San Juan de Miraflores near Lima, Peru. Mothers and newborn children were sorted into cohort groups based on the mothers' breast milk antibody response to Cryptosporidium sporozoites using an antibody-capture enzyme-linked immunosorbent assay to detect parasite-specific immunoglobulin A. Children were monitored for Cryptosporidium infection using an indirect immunofluorescence assay. Of 211 mothers enrolled in the study, 39 (18.5%) had high breast milk antibody titers, 107 (50.7%) had medium titers, and 65 (30.8%) had low titers. Sixty-one episodes of Cryptosporidium infection were detected in 50 children of these mothers. Eleven (22%) had mothers in the high antibody titer group, 20 (40%) had mothers in the medium titer group, and 19 (38%) had mothers in the low titer group. The prevalence of infection within children of each group was 0.17, 0.19 and 0.38 respectively. There was no significant difference in the prevalence or duration of infection among children of the different groups. The data does not support the notion that there is protection from Cryptosporidium infection afforded children whose mothers have demonstrable breast milk antibodies against the parasite.     

Epidemiology of toxoplasmosis in Chile. VI. Prevalence of human infection, investigated by means of an indirect hemagglutination test, in regions VII, VIII and IX

In presecuting the investigations on the epidemiology of toxoplasmosis in Chile, a new series of serological surveys has been performed during 1982-1989 in 10 urban and 25 periurban-rural localities from the regions VII, VIII and IX of the country (34 degrees 41'-39 degrees 38' South lat.). In 9,758, randomly selected apparently healthy persons, and indirect hemagglutination test (IHAT) for toxoplasmosis was carried out. The age of these individuals (4,203 males and 5,555 females) varied between 4 and 84 years. The examined persons represent a 0.33% of the total population of the three studied regions. IHAT titers of 1: > or = 16 were regarded as positive. The global prevalence for positive IHAT was 45.5% (50.5% in men and 41.7% in women). A higher proportion of positive tests was observed in urban areas (47.0%) than in periurban-rural sections (33.3%). An increasing prevalence with age was also observed. Only 5 (0.05%) persons had IHAT titers higher than 1:1000.     

Biological and biochemical differences between in vitro- and in vivo-reared Exorista larvarum

Quantitative and qualitative parameters of Exorista larvarum (L.) (Diptera: Tachinidae) reared on two insect-material-free artificial media and in the factitious host Galleria mellonella L. (Lepidoptera: Pyralidae) were compared. Significantly higher puparial yields and weights were obtained in both a milk-based and a veal homogenate-based medium than in the factitious host. Longevity and parasitization rates were not different between the in vitro- and in vivo-reared flies. Despite the greater puparial weight of the veal medium-reared E. larvarum females, the number of eggs laid by these females on host larvae was not higher than that of females reared under the other two rearing conditions. Moreover, in a complementary experiment, with homogeneous puparial weights of milk medium- and host-reared females, the former oviposited fewer eggs. Hence, puparial weight alone is not a reliable quality parameter for E. larvarum reared on artificial media. Lower amino acid content, with a deficiency in aromatic amino acids and an excess in proline, was found for in vitro third instar parasitoid larvae reared on both media compared to the in vivo-reared ones. These results suggest a correlation between the amino acid deficiency and imbalance of medium-reared larvae and the lower number of eggs laid by the females obtained.     

The development of white adipose tissue. Effect of litter size on the lipoprotein lipase activity of four adipose-tissue depots, serum immunoreactive insulin and tissue cellularity during the first year of life in male and female rats.

(1.) Male and female rats reared in litters of four gained body weight more rapidly than animals reared in litters of 16. The differences were more marked in males than females and became less marked in both sexes with advancing age. (2.) The relative weights of the perigenital, perirenal, subcutaneous and intramuscular white-adipose-tissue sites in the animals from small litters indicated their relative obesity compared with animals from large litters. A sex-related difference in the distribution of adipose tissue between the four sites was seen in animals reared in litters of both four and 16. (3.) Although at 30 days of age all the animals had more numerous and larger fat-cells in their white-adipose-tissue depots than animals reared in large litters, the pattern of change thereafter was both site- and sex-specific. During the post-weaning period (30-300 days), although detailed differences were apparent between sites, a general pattern of increased cell size in males and increased cell numbers in females emerged as being the important determinants responsible for the differences in depot sizes seen when animals from litters of four and 16 were compared. (4.) Lipoprotein lipase activities, expressed as units/g fresh wt. of tissue, in the depots of animals reared in groups of four were unaltered compared with those reared in groups of sixteen during the post-weaning period (47-300 days of age), and enzyme activities expressed per depot merely reflected differences in tissue weights. (5.) Lipoprotein lipase activities per 10(6) cells were higher in males reared in fours compared with those reared in sixteens of equivalent age, but were unaltered for females. (6.) The persistent hyperinsulinaemia of animals reared in litters of four is discussed in relation to the observed differences in enzyme activity and white-adipose-tissue cellularity.     

Experimental autoimmune myasthenia gravis: can pretreatment with 125I-labeled receptor prevent functional damage at the neuromuscular junction?

Rats were immunized with purified receptor from electric fish to induce experimental autoimmune myasthenia gravis (EAMG). It is implied by the clonal selection theory that antigens react only with receptors on specific immunocompetent cell subpopulations. In an attempt to damage these specific cells with the aid of highly radioactive antigen, one group of rats was pretreated with an additional injection of radiolabeled receptor of high specific activity 3 days before the basic immunization. The success of the immunization was monitored by measuring changes in the following three parameters: antibody titers against nicotinic acetylcholine receptor; number of alpha-bungarotoxin-binding sites at endplates; and number of acetylcholine-operated ionic endplate channels, using quantitative electrophysiologic methods. Conventionally immunized animals showed the classical signs of EAMG: elevated antibody titers against nicotinic acetylcholine receptor and a reduction of the number of alpha-bungarotoxin-binding sites, as well as reduction of the number of acetylcholine-operated ionic channels. The same symptoms were found in animals pretreated with unlabeled receptor and in animals pretreated with radioactive albumin. Animals pretreated with radioactively labeled receptor showed far less reduction of functional nicotinic acetylcholine receptor and only slightly raised antibody titers. This study suggests that preimmunization with radioactive antigen selectively eliminates immunocompetent cells, thus precluding the production of antibodies by a subsequent immunization procedure. The same protective effect cannot be obtained by either preimmunization with unlabeled antigen or by radioactively labeled unspecific antigen.     

Indirect Hemagglutinating Antibody Response to Herpesvirus hominis Types 1 and 2 in Immunized Laboratory Animals and in Natural Infections of Man

Indirect hemagglutinating (IHA) antibody responses to Herpesvirus hominis types 1 and 2 (HVH-1 and HVH-2) were compared to complement-fixing and neutralizing antibody responses in immunized laboratory animals (rabbits, guinea pigs, and hamsters) and in natural infections of man. With the immunized animals, type specificity was seen only in the IHA test and only with antisera produced in hamsters and in the rabbits immunized with HVH-2. In human nongenital infections (considered to be caused predominately by HVH-1), IHA and neutralizing antibodies developed at about the same rate and reached approximately the same levels for HVH-1 and HVH-2. IHA titers tended to be higher than neutralizing antibody titers for both virus types. In genital infections (considered to be caused predominately by HVH-2), there was a rapid IHA antibody response to HVH-2, and the early HVH-2 antibody demonstrable by IHA, but not by neutralization tests, was found to be immunoglobulin M in nature. In genital infections, IHA titers for HVH-2 were markedly higher than neutralization titers, but there was no pronounced difference in neutralizing the IHA antibody titers for HVH-1. Several patients with genital infections fialed to develop IHA antibody for HVH-1. The IHA test possessed no greater sensitivity than did complement fixation or neutralization tests for serodiagnosis of HVH infections. Despite the fact that a number of patients with genital infections produced IHA antibody only for HVH-2, the test was no more effective than the neutralization test in providing a type-specific serodiagnosis of infection, due largely to the fact that the rapid IHA antibody response to HVH-2 prevented demonstration of a further, significant antibody titer increase in a number of cases.     

Effects of delivery method on serological responses of bighorn sheep to a multivalent Pasteurella haemolytica supernatant vaccine

The safety and efficacy of a remotely delivered multivalent Pasteurella haemolytica supernatant vaccine (serotypes A2 and T10) were examined in captive Rocky, Mountain bighorn sheep (Ovis canadensis canadensis). Twenty bighorn sheep were grouped according to baseline leukotoxin neutralizing antibody titers (< or =2 or >2 log2(-1)) and vaccination history (previously vaccinated or unvaccinated). Within these groups, animals were randomly assigned to one of two delivery treatments: hand injection (control) or biobullet implantation. All bighorns received a single dose from the same lot of vaccine (n = 10/treatment); four additional animals were injected intramuscularly with 0.9% saline as unvaccinated sentinels. Mild, transient lameness one day after hand injection or biobullet implantation was the only adverse effect. Serum neutralizing antibody titers to P. haemolytica leukotoxin differed between delivery treatments (P = 0.009) and among baseline titer/vaccination history groups (P = 0.013). Neutralizing titers were higher among hand-injected bighorns. Although neutralizing titers were lower among implanted bighorns than hand-injected controls at 1 wk (P = 0.002) and 2 wk (P = 0.021) after vaccination, seroconversion rates in response to implantation (6/10) and hand injection (9/10) did not differ (P = 0.303). Agglutinating antibody titers to T10 were high and did not vary over time or between delivery treatments. Agglutinating antibody titers to A2 in the hand-injected controls were not different (P > or = 0.07) than those in bighorns vaccinated with biobullet implantation. These data demonstrate that although hand injection elicits higher absolute titers, biobullet implantation may also stimulate effective antibody responses to P. haemolytica supernatant vaccine. Further evaluation of biobullet vaccination against pneumonic pasteurellosis in free-ranging populations of wild bighorn sheep is warranted.     

Transgenic Mice Secreting Coronavirus Neutralizing Antibodies into the Milk

Ten lines of transgenic mice secreting transmissible gastroenteritis coronavirus (TGEV) neutralizing recombinant monoclonal antibodies (rMAbs) into the milk were generated. The rMAb light- and heavy-chain genes were assembled by fusing the genes encoding the variable modules of the murine MAb 6A.C3, which binds an interspecies conserved coronavirus epitope essential for virus infectivity, and a constant module from a porcine myeloma with the immunoglobulin A (IgA) isotype. The chimeric antibody led to dimer formation in the presence of J chain. The neutralization specific activity of the recombinant antibody produced in transiently or stably transformed cells was 50-fold higher than that of a monomeric rMAb with the IgG1 isotype and an identical binding site. This rMAb had titers of up to 10⁴ by radioimmunoassay (RIA) and neutralized virus infectivity up to 10⁴-fold. Of 23 transgenic mice, 17 integrated both light and heavy chains, and at least 10 of them transmitted both genes to the progeny, leading to 100% of animals secreting functional TGEV neutralizing antibody during lactation. Selected mice produced milk with TGEV-specific antibody titers higher than 10⁶ as determined by RIA, neutralized virus infectivity by 10⁶-fold, and produced up to 6 mg of antibody per ml. Antibody expression levels were transgene copy number independent and integration site dependent. Comicroinjection of the genomic β-lactoglobulin gene with rMAb light- and heavy-chain genes led to the generation of transgenic mice carrying the three transgenes. The highest antibody titers were produced by transgenic mice that had integrated the antibody and β-lactoglobulin genes, although the number of transgenic animals generated does not allow a definitive conclusion on the enhancing effect of β-lactoglobulin cointegration. This approach may lead to the generation of transgenic animals providing lactogenic immunity to their progeny against enteric pathogens.     

Ovine Toxoplasmosis in Sweden

Sera from 155 ewes representing 21 different sheep flocks from the central parts of Sweden were examined for the presence of antibodies to Toxoplasma gondii by the indirect fluorescent-antibody test. Seropositive animals were found in 14 flocks, which corresponded to 55 % of the tested sera. Animals from the same flock were with few exceptions either all positive or all negative. Some ewes with a history of abortion a few months before blood sampling showed high titers indicating causative correlation with toxoplasmosis. These are the first verified cases of ovine toxoplasmal abortions in Sweden.     

The detection of anti-<Emphasis Type="Italic">Candida</Emphasis> antibodies on experimental animal models

The levels of anti-Candida antibodies were determined in experimental animals immunized with 4 different yeast doses (0.3, 0.6, 1.2, 2.4 x 10(8) CFU) at weekly intervals. After immunization (sampling intervals 1, 2, and 3 months), the intravenous blood was examined for the presence of serum anti-Candida antibodies. After one month, the titers of anti-Candida antibodies reached 1:40-1: 1280 and remained at the same level after two months in the majority of animals; only in a few of them the titers increased or were detected de novo. After three months, when the animals were no longer immunized, a decreasing trend in antibody titers was detected in the majority of animals.     

Abnormal anti-Epstein Barr virus antibodies in carriers of the X-linked lymphoproliferative syndrome and in females at risk

The asymptomatic hemizygous female carriers of the X-linked lymphoproliferative syndrome (XLP) have abnormal antibody responses to EBV. This suggests partial expression of the defect that leads to EBV-provoked life-threatening diseases in their affected sons. EBV specific antibodies were measured in 65 serum samples of 12 obligate carrier females and seven of their daughters (females at risk) during periods ranging from 1 to 5 yr. Abnormal qualitative antiviral capsid antigen (VCA) IgG titers were nearly fourfold higher than normal controls, two carriers had persistent IgM anti-VCA antibody, two-thirds had persistent IgA anti-VCA antibody, and half of the women had titers to early antigen (EA). Five of seven females exhibited a similar persistent pattern. In contrast, none of the unaffected family members nor 23 normal controls expressed IgA or IgM titers to VCA even with high exposure to the virus, and anti-EA was detected in only one control. Therefore, these findings may prove useful for detecting carriers of the syndrome. Abnormal anti-EBV titers similar to the carrier pattern have been reported in patients and other immunosuppressed individuals, and are indicative of active viral infection.     

Toxoplasma gondii: Congenital transmission in a hamster model

The objective of the research was to test the hamster for a model of transmission of congenital toxoplasmosis. A non-invasive method for the diagnosis of pregnancy in hamsters was designed, with a specificity and a sensitivity of 70.2 and 94.7%, respectively (n = 168). Of 32 females with a chronic toxoplasma infection, 3 transmitted Toxoplasma congenitally during their first pregnancy, but not during the subsequent pregnancy. Congenital transmission rates of infections initiated during pregnancy with 2 stages of 2 strains of Toxoplasma were in the range of 33 to 100% of the 76 females inoculated. Only 1 of 17 females transmitted the parasite exclusively via milk. It was concluded that the hamster is a promising species for a model of transmission of congenital toxoplasmosis.