Involvement of mast cells in inflammation induced by Trichomonas vaginalis via crosstalk with vaginal epithelial cells

Vaginal epithelial cells (VECs) are thought to function as immune-responsive cells in trichomoniasis, and mast cells have been detected in vaginal smears and the vaginal wall in trichomoniasis. It therefore seemed possible that the VEC-trichomonad reaction might affect the activity of mast cells present in the lamina propria of the vaginal mucosa. In this study, we tested whether culture supernatants of VEC incubated with Trichomonas vaginalis (TCM) could stimulate mast cells. When VECs (MS74) were incubated with live trichomonads, IL-8, IL-6 and MCP-1 expressions increased in the TCM, and mast cells (HMC-1) and human neutrophils migrated more actively towards the TCM. Also, when the TCM was added to mast cells, β-hexosaminidase and cytokines (IL-8 and TNF-α) expressions were increased. Moreover, the culture supernatant of mast cells incubated with TCM (M-TCM) had more increased chemotactic activity for neutrophils than that of TCM. We conclude that inflammatory mediators made by VECs in response to activation by T. vaginalis activate and attract mast cells and then stimulate them to induce neutrophil migration. Our results indicate, for the first time, that VECs play a role in the infiltration of mast cells and neutrophils early in T. vaginalis infection.

Trichomonas vaginalis-induced neutrophil apoptosis causes anti-inflammatory cytokine production by human monocyte-derived macrophages

Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with a Trichomonas vaginalis infection. Neutrophils have a shorter life span than other leucocytes. Our previous study indicated that live T. vaginalis alters Mcl-1 expression and caspase-3 activation, thereby inducing apoptosis of human neutrophils. However, it was previously unknown that the apoptotic neutrophils brought about by T. vaginalis can influence vaginal inflammation. Thus, human monocyte-derived macrophages (HMDM) were incubated with T. vaginalis-induced apoptotic neutrophils. Cytokine production and phagocytosis by HMDM were evaluated by ELISA and myeloperoxidase stain, respectively. HMDM showed increased anti-inflammatory cytokine production (IL-10) and decreased levels of pro-inflammatory cytokines, such as TNF-α and IL-6, compared with macrophages alone.

Trichomonas vaginalis promotes apoptosis of human neutrophils by activating caspase-3 and reducing Mcl-1 expression

Neutrophils are the predominant inflammatory cells found in the vaginal discharge of patients with Trichomonas vaginalis infection. However, it is not known whether neutrophil apoptosis is induced by live T. vaginalis. Therefore, we examined whether T. vaginalis can influence neutrophil apoptosis, and also whether caspase-3 and the Bcl-2 family members are involved in the apoptosis. Thus, human neutrophils were incubated with live T. vaginalis and neutrophil apoptosis was evaluated by Giemsa, annexin V-PI, and DiOC6 stainings. The neutrophil apoptosis was significantly higher in those incubated with T. vaginalis than in the control group. When trichomonads were pre-treated with mAb to AP65 (adhesin protein), or when trophozoites were separated from neutrophils using a Transwell chamber, neutrophil apoptosis was significantly reduced. The activation of caspase-3 was evident in neutrophils undergoing spontaneous apoptosis but was markedly enhanced during T. vaginalis-induced apoptosis. Moreover, the inhibition of caspase-3 effectively reduced T. vaginalis-induced apoptosis. Trichomonad-induced apoptosis was also associated with reduced expression of the neutrophil anti-apoptotic protein, Mcl-1. These results indicate that T. vaginalis alters Mcl-1 expression and caspase-3 activation, thereby inducing apoptosis of human neutrophils.

Observation of the narrow state X(3872)-->J/psipi+pi- in pp collisions at sqaure root of s=1.96 TeV

We report the observation of a narrow state decaying into J/psipi+pi- and produced in 220 pb(-1) of p p-bar collisions at =1.96 Tesqaure root of sV in the CDF II experiment. We observe 730+/-90 decays. The mass is measured to be 3871.3+/-0.7(stat)+/-0.4(syst) MeV/c2, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson.

Search for electron neutrino appearance in a 250 km long-baseline experiment

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Caspase-3-mediated apoptosis of human eosinophils by the tissue-invading helminth Paragonimus westermani

BACKGROUND

Eosinophils are important cells in host immunity to infections by parasitic worms. Tissue-invasive helminthic parasites have been known to induce apoptosis of immune cells for their successful establishment in vivo. We have previously found that high doses of excretory-secreted products (ESP) secreted by lung fluke Paragonimus westermani newly excysted metacercariae (PwNEM), which cause pulmonary or extrapulmonary paragonimiasis in human beings, accelerate eosinophil cell death. However, little is known about the mechanism of eosinophil apoptosis induced by the Paragonimus-derived products.

OBJECTIVE

We examined involvement of caspase 3 activation in eosinophil cell death induced by ESP produced by PwNEM.

METHODS

Eosinophils were isolated from the peripheral blood of healthy donors by CD16-negative immunomagnetic selection. We examined the inhibitory effect of pan-caspase inhibitor on ESP-triggered phosphatidylserine (PS) externalization on the outer surface of eosinophils and intracellular activation of caspase 3 in cell lysates treated with the ESP.

RESULTS

When ESP secreted by PwNEM were incubated for up to 3 h with eosinophils, they increased surface exposure of PS on eosinophils in a time- and dose-dependent manner. This proapoptotic effect of the ESP on eosinophils was significantly inhibited by pretreatment of cells with pan-caspase inhibitor z-VAD-fmk, and was completely abolished by heat inactivation of ESP at 56 degrees C. The activated forms of caspase 3 were also clearly detected in eosinophils incubated with ESP. Moreover, ESP potently inhibited prolonged survival of eosinophils induced by cytokines such as IL-5, IL-3, and GM-CSF.

CONCLUSION

These results suggest that ESP secreted by PwNEM contain biological active factors causing caspase-3-mediated apoptosis of human eosinophils, thereby enabling the larvae to evade and to subvert the tackle by eosinophils during the early phase of the infection.

Measurement of prompt charm meson production cross sections in pp collisions at square root s = 1.96 TeV

We report on measurements of differential cross sections dsigma/dp(T) for prompt charm meson production in ppmacr; collisions at sqrt[s]=1.96 TeV using 5.8+/-0.3 pb(-1) of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region |y|</=1 in four fully reconstructed decay modes: D0-->K-pi(+), D(*+)-->D0pi(+), D+-->K-pi(+)pi(+), D(+)(s)-->phipi(+), and their charge conjugates. The measured cross sections are compared to theoretical calculations.

Indications of neutrino oscillation in a 250 km long-baseline experiment

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Phylogenetic relationships between the six superoxide dismutase proteins (FeSOD) of Trichomonas vaginalis and FeSOD6 genetic diversity

The parasitic protozoan Trichomonas vaginalis is known to contain several types of Fe-containing superoxide dismutase proteins (FeSOD). Using three different methods of phylogenetic analysis, maximum parsimony (MP), neighbor joining (NJ), and maximum likelihood (ML) methods, we examined the phylogenetic relationships among the six FeSOD (FeSOD1-FeSOD6) based on their amino acid sequences. All the analyses consistently suggested that the six proteins formed a monophyletic group implying that they probably be originated from an ancestral protein form through repeated duplication events. Although MP tree was totally unresolved, the NJ and ML trees revealed that FeSOD6 placed the most basal position and thus emerged earlier than the other five gene types during the evolution of T. vaginalis. Phylogenetic relationships among the five remaining proteins were (FeSOD2, FeSOD3), (FeSOD4, (FeSOD1, FeSOD5)) although weakly supported in terms of bootstrapping values. In addition to this, we newly designed two PCR primer specifically amplifying full-length FeSOD6 gene and examined its genetic diversity among 12 T. vaginalis isolates from five countries and three continents. They had the same nucleotide sequences except those of three Korean isolates which showed one to three different nucleotides.

Nuclear factor-kappa B plays a major role in the regulation of chemokine expression of HeLa cells in response to Toxoplasma gondii infection

Toxoplasma gondii infection results in an infiltration of immune cells. The mechanisms responsible for triggering inflammatory cell infiltration in T. gondii infection are not fully understood. We report that T. gondii-infected HeLa cells induced nuclear factor-kappa B (NF-kappaB) activation and increased the expression of interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) mRNA. An inhibitor of NF-kappaB activation, calpain-1 inhibitor, blocked the chemokine secretion induced by live T. gondii. Activation of the IL-8 and NF-kappaB transcriptional reporters was suppressed in cells co-transfected with IkappaB kinase beta and the IkappaBalpha super-repressor plasmids. Moreover, the addition of IL-1alpha increased NF-kappaB activation and IL-8 mRNA expression in T. gondii-infected HeLa cells. These results suggest that NF-kappaB is a central regulator of the chemokine response in T. gondii-infected human epithelial cells and that chemokine IL-8 and MCP-1 secretion might be involved in the pathogenesis of T. gondii, via the recruitment of neutrophils, monocytes, and lymphocytes.

Effect of iron on the virulence of Trichomonas vaginalis

The role of iron was evaluated with respect to the virulence of Trichomonas vaginalis in mice. Iron-supplemented and iron-depleted Diamond's trypticase-yeast extract-maltose (TYM) media were prepared by adding 360 microM of ferrous sulfate and 100 microM of 2,2'-dipyridyl. Trophozoites cultivated from normal TYM and iron-supplemented TYM media produced subcutaneous abscesses; however, trichomonads grown in an iron-deficient TYM medium failed to produce any pathology. In addition to the increased virulence of trophozoites in mice, iron affects the level of adherence and the cytotoxicity of trichomonads to HeLa cells, which are significantly reduced in trophozoites grown in iron-deficient medium. In conclusion, it is suggested that under iron-depleted conditions such as that induced by 2,2'-dipyridyl the virulence of T. vaginalis is reduced.

Two imported cases of cutaneous larva migrans

Cutaneous larva migrans (CLM) is a rare serpiginous cutaneous eruption caused by accidental penetration and migration in the skin with infective larvae of nematode that normally do not have the human as their host. Although CLM has a worldwide distribution, the infection is most frequent in warmer climates. More recently, they have been increasingly imported from the tropics or subtropics by travelers. We experienced two patients who had pruritic serpiginous linear eruption in their skin for a few weeks after traveling to the endemic areas (Brazil and Thailand, respectively). After the treatment with albendazole, the skin lesions resolved with post-inflammatory hyperpigmentation. We report herein two cases of cutaneous larva migrans successfully treated with albendazole.

Toxoplasma gondii: ultrastructural localization of specific antigens and inhibition of intracellular multiplication by monoclonal antibodies

This experiment was focused on the characterization of anti-Toxoplasma monoclonal antibodies (mAbs) and the effect of mAbs on the parasite invasion of mouse peritoneal macrophages. Twenty eight mAbs including M110, M556, R7A6 and M621 were characterized by Ab titer, immunoglobulin isotyping and western blot pattern. Antibody titer (optical density) of 4 mAbs, M110, M556, R7A6 and M621, were 0.53, 0.67, 0.45 and 0.39 (normal mouse serum; 0.19) with the same IgG1 isotypes shown by Enzyme-linked immunosorbent assay (ELISA). Western blot analysis showed that M110, M556, R7A6 and M621 reacted with the 33 kDa (p30), 31 kDa (p28), 43 kDa and 36 kDa protein. Immunogold labelling of mAbs M110, M556, R7A6 and M621 reacted with the surface membrane, dense granules and parasitophorous vacuolar membrane (PVM), rhoptries and cytoplasm of tachyzoite, respectively. For in vitro assay, preincubation of tachyzoites with four mAbs, M110, M556, R7A6 and M621 resulted in the decrease of the number of infected macrophages (p < 0.05) and the suppression of parasite multiplication at 18 h post-infection. Four monoclonal antibodies including M110 (SAG1) were found to have an important role in the inhibition of macrophage invasion and T. gondii multiplication in vitro, and these mAbs may be suitable for vaccine candidates, diagnostic kit and for chemotherapy.

Degradations of human immunoglobulins and hemoglobin by a 60 kDa cysteine proteinase of Trichomonas vaginalis

The present study was undertaken to investigate the role of cysteine proteinase of Trichomonas vaginalis in escaping from host defense mechanism. A cysteine proteinase of T. vaginalis was purified by affinity chromatography and gel filtration. Optimum pH for the purified proteinase activity was 6.0. The proteinase was inhibited by cysteine and serine proteinase inhibitors such as E-64, NEM, IAA, leupeptin, TPCK and TLCK, and also by Hg2+, but not affected by serine-, metallo-, and aspartic proteinase inhibitors such as PMSF, EDTA and pepstatin A. However, it was activated by the cysteine proteinase activator, DTT. The molecular weight of a purified proteinase was 62 kDa on gel filtration and 60 kDa on SDS-PAGE. Interestingly, the purified proteinase was able to degrade serum IgA, secretory IgA, and serum IgG in time- and dose-dependent manners. In addition, the enzyme also degraded hemoglobin in a dose-dependent manner. These results suggest that the acidic cysteine proteinase of T. vaginalis may play a dual role for parasite survival in conferring escape from host humoral defense by degradation of immunoglobulins, and in supplying nutrients to parasites by degradation of hemoglobin.

Human syngamosis: the first case in Korea

Parasites of the genus Mammomonogamus affect the respiratory tract of domestic mammals but have only rarely been reported in humans. In this case report the diagnosis of human syngamosis is described following bronchoscopic examination of a patient whose initial symptoms were simply of community acquired pneumonia. The patient had a persistent and productive cough with intermittent fever during 10 days of observation. After bronchoscopic extraction of the parasites and treatment with albendazole he recovered fully. This is one of the first recognised cases of human syngamosis in Korea.

A human case of tick bite by Ixodes nipponensis

A human case of the tick bite on the back of 36-year-old man was found in September 1995. On admission he complained of itching sensation and pain at the site. The removed tick was identified morphologically as Ixodes nipponensis.

Partially purified Toxoplasma gondii antigens by immunoaffinity chromatography

Tachyzoite antigens of Toxoplasma gondii (RH) were partially purified by immunoaffinity chromatography. The cultivated Toxoplasma in vivo (mouse) and in vitro (Hep-2 cell) and peritoneal fluid of T. gondii infected mice were collected for antigen analysis. Tachyzoite antigens collected from infected mouse showed positive bands of 76 kDa, 70 kDa, 64 kDa, 53 kDa, 46 kDa, 44 kDa, 41 kDa, 35 kDa, 25 kDa, 18 kDa, and 13 kDa on immunoblot with anti-Toxoplasma rabbit sera, and those from infected Hep-2 cells revealed reactive bands of 70 kDa, 64 kDa, 53 kDa, 35 kDa 28 kDa, and 13-10 kDa. After applying to an IgG-Sepharose column, two elution peaks, E-1 and E-2 fractions, were obtained from both soluble antigen of T. gondii and the peritoneal fluid of infected mice, respectively. Immunoblots of soluble antigen with immunized rabbit sera revealed positive bands of 97 kDa, 63 kDa, 53 kDa, and 35 kDa from E-1 fraction and 53 kDa and 35 kDa from E-2. In the case of the eluted peaks from mice peritoneal fluid, E-1 showed protein bands of 84 kDa, 76 kDa, 53 kDa, and 29 kDa bands and 53 kDa and 45 kDa from E-2 on immunoblots. Serum IgG antibody titer of mice immunized with T. gondii tachyzoites was increased on 1 week after booster immunization when analysed by ELISA using crude antigen, while it was elevated on 3 weeks after booster immunization by ELISA using purified antigen.

Toxoplasma antibody titers by ELISA and indirect latex agglutination test in pregnant women

The seroepidemiologic studies on anti-Toxoplasma antibody titers were carried out using ELISA and indirect latex agglutination test. Among 899 sera prepared from pregnant women, 39 cases (4.3%) revealed positive reaction and 218 sera from middle school students showed 4 positive reaction (1.8%) by ELISA. By LAT (newly established by National Veterinary Research Institute. Korea), the sera of 7 pregnant women (0.8%) showed positive reaction. When 80 sera showing > or = 1:8 by LAT were used for comparing the results obtained from LAT and Toxotest-MT (Eiken Chemical Co., Japan), 7 cases and 8 sera were positive, respectively. All of 11 sera of proven toxoplasmosis patients showed positive reaction in both tests. Overall proportion of agreement between LAT kit and Toxotest-MT was 0.94 (kappa-index = 0.632, p < 0.011, and LAT was considered to be useful for the screening of toxoplasmosis.

Identification of surface antigen of Trichomonas vaginalis

Plasma membrane proteins of a Korean isolate of Trichomonas vaginalis HY-1 were fractionated for antigen analysis. Homogenates of T. vaginalis were fractionated by the differential centrifugation using sucrose step-gradient method. The interface layer from the 25%/45% sucrose was collected as a plasma membrane fraction and its purity was examined by transmission electron microscopy. The antigenicity of plasma membrane fraction was analysed by enzyme-linked immunoelectrotransfer blot technique with immune rabbit serum and compared with surface antigen labelled with N-hydroxysuccinimide-biotin. The fluffy fraction of 25%/45% sucrose interface was homogeneous and membrane particles were present as extended sheet and concentric vesicles showing typical trilamellar appearance under transmission electron microscope. Seven fractions at 40, 50, 60, 110, 130, 140 and 150 kDa were identified as the antigenic membrane proteins in EITB with anti HY-1 rabbit serum. The common band at 60 kDa was detected both in antigenic fractions of plasma membrane and surface protein labelled with NHS-biotin. This result indicates that this protein is considered as a major surface antigen of T. vaginalis. The role of this surface antigen at 60 kDa should be studied further.

[Antigen analysis of Toxoplasma gondii lysate and excretory-secretory materials by enzyme-linked immunoelectrotransfer blot (EITB)]

Recently, the importance of toxoplasmosis is raised as a complication in immunosuppressed or AIDS patients. Our study focused on the identification of a variety of Toxoplasma antigens by immunoblotting. Rabbits and BALB/c mice were immunized with Toxoplasma lysate (RH strain), frozen tachyzoites (RH strain) or cysts (Beverly and Fukaya strain). Blood were collected from ear vein, heart or orbital plexus for detecting the serum antibody levels. For excretory-secretory (E.S) antigens, T. gondii (RH) tachyzoite were cultured in CHL (Chinese hamster lung) cells with MEM containing of 5% FCS. After 72 hrs, culture supernatant was collected. BALB/c mice were inoculated with RH tachyzoite intraperitoneally and peritoneal fluids were extracted three days later. E.S antigens were detected in culture supernatant and infected mouse peritoneal fluid by EITB. Serum IgG levels in rabbit were 1:512 of 10 days after primary immunization, 1:2,048 of 10 days after secondary immunization, 1:1,024 of 20 days after secondary immunization by IFAT, respectively. Serum IgG levels of immunized mice were 1:128 after 7 weeks. Tachyzoite antigens of the RH strain were detected 25 protein bands ranging 10 kDa-220 kDa of molecular weights with Coomassie blue stain. Toxoplasma major antigens corresponding to MW of 24 kDa, 27 kDa, 30 kDa, 35 kDa, 38 kDa were recognized by IgG and IgM antibodies. Excretory-secretory antigens present in culture supernatant with M. W. of 20, 30 kDa and in infected mouse peritoneal fluid with M.W. of 33 (P30), 45 kDa. When RH tachyzoite antigen was probed with different mice sera immunized with 2 strains of T. gondii, the IgG antibody band of Fukaya and Beverly strain (8 week-serum) is identical to those of RH strain. It is considered that the 30 kDa polypeptide detected in excretory-secretory materials and lysate was important major antigen of T. gondii (RH).

Three dimensional shape reconstruction and finite element analysis of femur before and after the cementless type of total hip replacement

Computerized tomography was used to reconstruct a shape, and stresses in three-dimensional objects were analysed. The human femur, which has a very irregular shape, was chosen as an object. CT image data of a cadaver femur were transferred to a computer, and an edge extraction program generated the cross-section of bone by specifying a range of CT values for each slice. Pixel data from the CT scan are converted into a vector of points (x, y, z) which can specify the boundaries of bone. Lateral surfaces are defined by stacking up the slices and making use of the vectorized data. Intermediate and oblique cross-sections can be obtained by an interpolation technique. The constructed model was used as input data for the finite element analysis. To understand the stress distributions before and after the cementless type of total hip replacement, a three-dimensional finite element stress analysis of the bone-implant system was carried out, assuming micromotions between the stem and the femur. The analysis was done for both frictionless and friction cases, modelling the contact point with a gap element having isotropic friction. The analysis shows that the stress is not concentrated on the femoral calcar when the friction coefficient is large.

A TATA-like sequence located downstream of the transcription initiation site is required for expression of an RNA polymerase II transcribed gene

TFIID, the TATA-binding protein, was found to stimulate transcription from the adenovirus IVa2 promoter, a promoter considered to lack the TATA motif. Remarkably, a TATA-like sequence element located downstream of the transcription start site binds TFIID and is required for TFIID-dependent transcription from the IVa2 promoter. Transcription from the IVa2 and the adjacent adenovirus major late promoter (Ad-MLP) is divergent, and the cap sites are separated by 212 nucleotides. Nevertheless, the TATA motifs of the IVa2 promoter and Ad-MLP were found to be oriented in the same direction. An initiator motif around the transcription start site is located in the IVa2 promoter, and in contrast to the TATA motifs, the IVa2-initiator is in the opposite orientation with respect to the initiator of the Ad-MLP. A model is presented in which the polar nature of the initiator governs the direction of transcription. We propose that RNA polymerase II and accessory factors recognize the initiator in an orientation-dependent fashion. The recognition of the IVa2 initiator by RNA polymerase is enhanced by the binding of TFIID to the downstream TATA motif.

[The effects of antibodies and complement in macrophage-mediated cytotoxicity on metacercariae of the lung fluke, Paragonimus westermani]

Paragonimus westermani is a tissue migrating parasite in the early stage until arriving at lung, and most of the parasites spend their life spans there. Considerable immune responses including activation of macrophages are taken place during the residence of parasites in the host. However, concerning the immunologic defense mechanisms of the host against this parasite, only a few document is available so far. In this study, the cytotoxic effect of peritoneal macrophages under the presence of antibody and/or complement against metacercariae of P. westermani was investigated in vitro. Metacercariae were collected from the crayfish, Cambaroides similis and hatched out in Tyrode solution (pH 7.4). Plastic adherent cells from normal or infected rat (Wistar) peritoneal exudates were used as experimental macrophages. Polyclonal antibodies were obtained from infected rats and a cat. Cat IgG was fractioned with ion exchange chromatography. Fresh rabbit complement was used according to experimental scheme. Various combinations of peritoneal macrophages, normal or infected rat serum, complement and cat IgG were incubated at 36 degrees C in 5% CO2 incubator for 6, 14, 24 and 48 hours. The results obtained were as follows: 1. P. westermani infection activated peritoneal macrophages non-specifically and this activation induced increases of cell adherence and cytotoxicity on metacercariae. 2. In the presence of infected rat serum the antibody-dependent cell-mediated cytotoxicity of peritoneal macrophages on metacercariae was significantly increased and showed a peak at 6-hour incubation. But the cytotoxic effect was markedly reduced after inactivation of complement and heat-labile IgE antibody by the heating of infected serum at 56 degrees C for 30 minutes. 3. The highest cytotoxic effect (100%) of concomitant incubation with IgG and complement showed 24 hours after incubation, although cell adherence was relatively low at 6-hour incubation and 0% at 24-hour incubation. 4. Coordinative functions of complement with serum and IgG were effective in cell adherence and in cytotoxicity, but it is not clear the independent role of complement on the macrophage-mediated cytotoxicity in this study. With these results it is assumed that P. westermani infection can induce the non-specific activation of peritoneal macrophages, and serum antibodies including IgE antibody might enhance the cytotoxicity by macrophages.

[Cytotoxicity of resident and lymphokine-activated mouse peritoneal macrophage against Trichomonas vaginalis]

This study was aimed to observe the direct and lymphokine-activated cell mediated cytotoxic effects against Trichomonas vaginalis by mouse peritoneal macrophages. Cytotoxicity was measured as release of 3H-thymidine from prelabeled protozoa, and tested in U-bottom microtiter plates. A 0.1 ml suspension of labeled protozoa (2 x 10(5)/ml) was placed in each well, followed by 0.1 ml of a suspension containing increasing numbers of peritoneal cells. After a 24 hr incubation at 37 degrees C, 0.1 ml of the supernatant was collected and counted in liquid scintillation counter. Mouse peritoneal macrophages had appreciable level of spontaneous cytotoxicity against T. vaginalis at the effector to target cell ratios from 5:1 to 50:1. Treatment of macrophages with lymphokine, produced by PHA-stimulated spleen cells, increased the cytotoxicity in comparison with resident macrophages against T. vaginalis. The degree of macrophage activation for the killing was not dependent upon the lymphokine concentration. Peritoneal cells adherent to plastic displayed significant levels of cytotoxicity against T. vaginalis. This study indicates that mouse peritoneal macrophages are spontaneously cytotoxic for T. vaginalis and lymphokine increases the cytotoxicity by activating macrophages to kill T. vaginalis.

[Detection of IgG and IgM antibodies with ELISA technique in human trichomoniasis]

The direct wet mount examination of vaginal secretion, widely applied for the diagnosis of Trichomonas vaginalis infection in woman patients, is rapid and economical, however, the sensitivity of this technique is not so high. In this study enzyme-linked immunosorbent assay (ELISA) was employed for the detection of serum anti-T. vaginalis IgG and IgM antibodies from 30 vaginal trichomoniasis patients and 30 non-infected healthy persons. The results were as follows: 1. Serum ELISA-IgG value was 0.37 +/- 0.134 (Mean +/- S.D.) in vaginal trichomoniasis patients and 0.21 +/- 0.054 in healthy controls (p less than 0.005), and the sensitivity and specificity of ELISA for serum IgG antibody were 70.0% and 96.7%, respectively. 2. Serum ELISA-IgM value was 0.33 +/- 0.177 (Mean +/- S.D.) in vaginal trichomoniasis patients and 0.11 +/- 0.051 in healthy controls (p less than 0.005), and the sensitivity and specificity of ELISA for serum IgM antibody were 70.0% and 96.7%, respectively. 3. The ELISA-IgG values showed a significant correlation with ELISA-IgM values (r = 0.77, p less than 0.005). With above results, it is assumed that ELISA is a reliable method for the diagnosis of T. vaginalis infection and simultaneous measurement of serum IgG and IgM with this technique is recommended.

[Resistance to Naegleria fowleri infection passively acquired from immunized splenocyte, serum or milk]

A pathogenic free-living amoeba, Naegleria fowleri, causes primary amoebic meningoencephalitis to human and experimental animals. This infection is rare, but the mortality is very high. Nowadays, drug treatment or active immunization of human or mice are being tried with partial effectiveness. This study shows passive immunization effect by transfer of immunized spleen cells, serum, or milk from immunized mother in mouse experimental model. Young BALB/c mice were immunized intraperitoneally with 2-3 X 10(6) trophozoites of N. fowleri, and spleen cells and sera were collected for injection to recipient mice. There were seven transfer groups, i.e., immunized mouse serum, spleen cells, serum and spleen cells, normal mouse serum, spleen cells, serum and spleen cells, and control group. Three days later, BALB/c mice were inoculated with 1 x 10(4) trophozoites of N. fowleri intranasally. After infection, decreased mortality and prolonged survival time of mice were noted in immunized groups compared with non-immunized control group. The groups injected with immunized spleen cells or normal serum showed lower mortality than that of controls but showed no changes of serum IgG level. The groups injected with immunized serum or normal spleen cells showed increased serum IgG level after immunization but hundred percent mortality was observed. Mother mice were immunized intraperitoneally with 2-3 X 10(6) trophozoites of N. fowleri at the end of pregnancy and weaning period. Soon after the delivery, litters born of non-immunized mother were matched with immunized mother for feeding immune milk. After three weeks, the litters were infected with 1 X 10(4) trophozoites of N. fowleri or sacrificed for serum collection to measure the IgG levels.(ABSTRACT TRUNCATED AT 250 WORDS)