Effects of Activin A on the phenotypic properties of human periodontal ligament cells

Periodontal ligament (PDL) tissue plays an important role in tooth preservation by structurally maintaining the connection between the tooth root and the bone. The mechanisms involved in the healing and regeneration of damaged PDL tissue, caused by bacterial infection, caries and trauma, have been explored. Accumulating evidence suggests that Activin A, a member of the transforming growth factor-β (TGF-β) superfamily and a dimer of inhibinβa, contributes to tissue healing through cell proliferation, migration, and differentiation of various target cells. In bone, Activin A has been shown to exert an inhibitory effect on osteoblast maturation and mineralization. However, there have been no reports examining the expression and function of Activin A in human PDL cells (HPDLCs). Thus, we aimed to investigate the biological effects of Activin A on HPDLCs. Activin A was observed to be localized in HPDLCs and rat PDL tissue. When PDL tissue was surgically damaged, Activin A and IL-1β expression increased and the two proteins were shown to be co-localized around the lesion. HPDLCs treated with IL-1β or TNF-α also up-regulated the expression of the gene encoding inhibinβa. Activin A promoted chemotaxis, migration and proliferation of HPDLCs, and caused an increase in fibroblastic differentiation of these cells while down-regulating their osteoblastic differentiation. These osteoblastic inhibitory effects of Activin A, however, were only noted during the early phase of HPDLC osteoblastic differentiation, with later exposures having no effect on differentiation. Collectively, our results suggest that Activin A could be used as a therapeutic agent for healing and regenerating PDL tissue in response to disease, trauma or surgical reconstruction.

Expression and effects of epidermal growth factor on human periodontal ligament cells

Repair of damaged periodontal ligament (PDL) tissue is an essential challenge in tooth preservation. Various researchers have attempted to develop efficient therapies for healing and regenerating PDL tissue based on tissue engineering methods focused on targeting signaling molecules in PDL stem cells and other mesenchymal stem cells. In this context, we investigated the expression of epidermal growth factor (EGF) in normal and surgically wounded PDL tissues and its effect on chemotaxis and expression of osteoinductive and angiogenic factors in human PDL cells (HPDLCs). EGF as well as EGF receptor (EGFR) expression was observed in HPDLCs and entire PDL tissue. In a PDL tissue-injured model of rat, EGF and IL-1β were found to be upregulated in a perilesional pattern. Interleukin-1β induced EGF expression in HPDLCs but not EGFR. It also increased transforming growth factor-α (TGF-α) and heparin-binding EGF-like growth factor (HB-EGF) expression. Transwell assays demonstrated the chemotactic activity of EGF on HPDLCs. In addition, EGF treatment significantly induced secretion of bone morphogenetic protein 2 and vascular endothelial growth factor, and gene expression of interleukin-8 (IL-8), and early growth response-1 and -2 (EGR-1/2). Human umbilical vein endothelial cells developed well-formed tube networks when cultured with the supernatant of EGF-treated HPDLCs. These results indicated that EGF upregulated under inflammatory conditions plays roles in the repair of wounded PDL tissue, suggesting its function as a prospective agent to allow the healing and regeneration of this tissue.

Biomarkers for intracellular pathogens: establishing tools as vaccine and therapeutic endpoints for visceral leishmaniasis

Visceral leishmaniasis in South Asia is a serious disease affecting children and adults. Acute visceral leishmaniasis develops in only a fraction of those infected individuals, the majority being asymptomatic with the potential to transmit infection and develop disease. We followed 56 individuals characterized as being asymptomatic by seropositivity with rk39 rapid diagnostic test in a hyperendemic district of Bangladesh to define the utility of Leishmania-specific antibodies and DNA in identifying infection. At baseline, 54 of the individuals were seropositive with one or more quantitative antibody assays and antibody levels persisted at follow up. Most seropositive individuals (47/54) tested positive by quantitative PCR at baseline, but only 16 tested positive at follow up. The discrepancies among the different tests may shed light on the dynamics of asymptomatic infections of Leishmania donovani, as well as underscore the need for standard diagnostic tools for active surveillance as well as assessing the effectiveness of prophylactic and therapeutic interventions.

The distribution of hereditary erythrocytic disorders associated with malaria, in a lowland area of Nepal: a micro-epidemiological study

Among four ethnic groups in a lowland area of Nepal, the prevalences of abnormal haemoglobin, thalassaemia, glucose-6-phosphate-dehydrogenase (G6PD) deficiency, hereditary South-east Asian ovalocytosis (SAO) and Duffy blood-group antigen Fy/Fy were determined and related to each group's habitat. The group that has lived for many decades in a malaria-endemic lowland area, the Danuwar, was found to have a high prevalence of alpha+-thalassaemia (79.4%) and low prevalences of haemoglobin E and G6PD deficiency. Much lower prevalences of alpha+-thalassaemia were observed in the Newar (20.5%), Parbate (16.5%) and Tamang (8.8%), who, until the 1950s, all spent their hot-season nights in malaria-free areas at higher altitudes. No subjects with any other identified abnormal haemoglobin, beta-thalassaemia, SAO or Fy/Fy were detected.

In vitro fertilization and development of bovine oocytes recovered from the ovaries of individual donors: A comparison between the cutting and aspiration method

Bovine oocytes were recovered from ovaries by either the cutting or the aspiration method, after which the oocytes were fertilized and cultured in vitro to investigate their developmental ability. In the cutting method, the surface and the interior of ovaries were cut with a set of 10 razors stacked at 2-mm intervals in modified TCM-199 medium supplemented with 5% fetal bovine serum; the liberated oocytes were then collected. In the aspiration method all visible follicles (2 to 5 mm in diameter) at the ovarian surface were aspirated with a syringe and an 18-gauge needle. Significantly more oocytes were recovered by the cutting than the aspiration method (mean: 63.3 vs 22.1), and the proportion of Rank A oocytes was also higher for the cutting method (84.6 vs 41.3%). Although no significant differences were observed between the 2 methods in the proportion of fertilized oocytes developing to the blastocyst stage in culture, the average number of blastocysts obtained by the cutting method was about 3.6-fold higher than by aspiration. The blastocysts were transferred nonsurgically to 37 (cutting method) and 36 (aspiration method) recipients, and 22 (59.0%) and 19 (52.8%), respectively, became pregnant.

Clinical and radiological features of rotavirus cerebellitis

BACKGROUND AND PURPOSE

Neurological manifestations, such as benign convulsions and encephalitis/encephalopathy have been reported in patients with rotavirus gastroenteritis. However, cerebellitis has not attracted much attention. The purpose of this study was to identify and report the clinical and radiologic features of rotavirus cerebellitis.

MATERIALS AND METHODS

Records of patients with rotavirus gastroenteritis exhibiting cerebellar lesions on MR imaging were collected from multiple centers in Japan. Their clinical, laboratory, and radiologic data were reviewed retrospectively.

RESULTS

A diagnosis of acute cerebellitis concurrent with encephalitis was made for 11 of 13 patients identified. Two patients who were diagnosed as having injury due to hypovolemic shock were excluded from the study. All 11 patients with acute cerebellitis had disorders of consciousness with onset on days 2 to 4, followed by mutism in 10 patients. Other cerebellar symptoms included dysarthria following the mutism, hypotonia, ataxia, tremor, nystagmus, and dysmetria. MR imaging lesions in the vermis or cerebellar cortex were seen at some point (day 5 to 1 year) in 10 patients. A reversible splenial lesion (3 isolated and 3 with concurrent cerebellar lesions) was found in 6 patients scanned between days 4 and 6. Transient lesions in the cerebellar white matter/nuclei manifesting reduced diffusion were seen in 6 patients during days 5 through 7. The final MR imaging performed after 1 month showed cerebellar atrophy in 10 patients.

CONCLUSIONS

The 11 patients with rotavirus cerebellitis exhibited nearly identical clinical and MR imaging features. Involvement of the cerebellar white matter/nuclei may be associated with the mutism. An isolated splenial lesion with homogeneously reduced diffusion is not always a benign sign indicative of complete clinical and radiologic recovery in patients with rotavirus gastroenteritis.

Novel mutations in Myoclonin1/EFHC1 in sporadic and familial juvenile myoclonic epilepsy

BACKGROUND

Juvenile myoclonic epilepsy (JME) accounts for 3 to 12% of all epilepsies. In 2004, the GENESS Consortium demonstrated four missense mutations in Myoclonin1/EFHC1 of chromosome 6p12.1 segregating in 20% of Hispanic families with JME.

OBJECTIVE

To examine what percentage of consecutive JME clinic cases have mutations in Myoclonin1/EFHC1.

METHODS

We screened 44 consecutive patients from Mexico and Honduras and 67 patients from Japan using heteroduplex analysis and direct sequencing.

RESULTS

We found five novel mutations in transcripts A and B of Myoclonin1/EFHC1. Two novel heterozygous missense mutations (c.755C>A and c.1523C>G) in transcript A occurred in both a singleton from Mexico and another singleton from Japan. A deletion/frameshift (C.789del.AV264fsx280) in transcript B was present in a mother and daughter from Mexico. A nonsense mutation (c.829C>T) in transcript B segregated in four clinically and seven epileptiform-EEG affected members of a large Honduran family. The same nonsense mutation (c.829C>T) occurred as a de novo mutation in a sporadic case. Finally, we found a three-base deletion (-364--362del.GAT) in the promoter region in a family from Japan.

CONCLUSION

Nine percent of consecutive juvenile myoclonic epilepsy cases from Mexico and Honduras clinics and 3% of clinic patients from Japan carry mutations in Myoclonin1/EFCH1. These results represent the highest number and percentage of mutations found for a juvenile myoclonic epilepsy causing gene of any population group.

Amelioration of human lupus-like phenotypes in MRL/lpr mice by overexpression of interleukin 27 receptor alpha (WSX-1)

Objective:

In the present work, we investigate the role of interleukin (IL)27/IL27 receptor α (Rα) (WSX-1) in the development of autoimmune disorders in the MRL/lpr mouse, which is considered as an experimental model of systemic lupus erythaematosus (SLE) in humans.

Methods:

We generated two strains of WSX-1 transgenic mice in the MRL/lpr background with different expression levels of WSX-1, and investigated the effect of WSX-1 overexpression on survival, glomerulonephritis and immunological properties.

Results:

In comparison with wild type (WT) MRL/lpr and transgenic (Tg) low (TgL) mice, Tg high (TgH) mice exhibited a prolonged lifespan and no apparent development of autoimmune nephritis. Production of anti-dsDNA antibody and total IgG and IgG2a were significantly lower in TgH mice than those of TgL and WT mice. The expressed amounts of interferon (IFN)γ and IL4 mRNA by CD4⁺ T cells from Tg mice decreased in a dose-dependent fashion. CD4⁺ splenic lymphocytes in TgH mice were more subject to the IL27-mediated suppression of cytokine production. In vitro stimulation of CD4⁺ T cells by IL27 resulted in over phosphorylation of STAT3 in TgH cells than in WT cells.

Conclusion:

WSX-1 overexpression in the MRL/lpr background rendered the autoimmune prone mice protected from the development of autoimmune diseases. Our results suggest that IL27 signalling may be a therapeutic target against autoimmune diseases, including human SLE.

117 EFFECT OF STEPWISE DILUTION ON THE VIABILITY OF FROZEN - THAWED BOVINE OOCYTES MATURED IN VITRO

The purpose of this study was to evaluate the effect of stepwise dilution on the viability of frozen–thawed bovine oocytes matured in vitro. Oocytes matured in vitro were denuded and equilibrated in modified TCM-199 (m199: 11 mmol L-1 HEPES, 9 mmol L-1 Na-HEPES, 5 mmol L-1 NaHCO3, 20% (v/v) calf serum) supplemented with 10% (v/v) glycerol for 15 min at room temperature (RT). Then they were exposed to m199 with 10% glycerol and 0.25 mol L-1 sucrose and loaded into 0.25-mL plastic straws. The straws were sealed and seeded at -6�C, cooled at the rate of 0.33�C min-1 to -25�C, and plunged into LN2. For thawing, the straws were first held in air at RT for 10 s, followed by immersion in 30�C water for 10 s. In the first experiment, frozen-thawed oocytes were subjected to cryoprotectants in 5 different manners of dilution. In the non-step dilution, the oocytes (n = 60) were put into m199 for 5 min. In the single-step dilution, the oocytes (n = 37) were transferred to 0.25 mol L-1 sucrose in m199 for 5 min. In the two-step dilution, the oocytes (n = 56) were transferred to 0.5 and then 0.25 mol L-1 sucrose in m199 for 5 and 5 min, respectively. In the three-step dilution, the oocytes (n = 57) were transferred to 0.75, 0.5, and 0.25 mol L-1 sucrose in m199 for 1, 5, and 5 min, respectively. In the four-step dilution, the oocytes (n = 52) were transferred to 1.0, 0.75, 0.5, and 0.25 mol L-1 sucrose in m199 for 1, 1, 5, and 5 min, respectively. After dilution, all of the oocytes were washed twice in TCM-199 supplemented with 5% fetal bovine serum for 5 min and cultured for 1 h to assess the morphology. The rate of morphological normal oocytes in the four-step dilution (94.2%) was significantly (P < 0.05) higher than that in other groups (non-, single-, two-, and three-step dilution: 61.7%, 73.0%, 78.6%, and 77.2%). In the second experiment, non-frozen (control, n = 170) and frozen–thawed oocytes (n = 145) with four-step dilution were fertilized and cultured in vitro (Kuwayama 1992 J. Reprod. Fert. 96, 187–193). To assess fertilization, some of the oocytes were fixed at 10 h after insemination. Cleavage and blastocyst rates were determined on Day 2 and Day 8 after fertilization (Day 0), respectively. There was no difference (P > 0.05) between control and frozen–thawed oocytes in the fertilization rate (88.0% vs. 93.1%). Some of the frozen–thawed oocytes cleaved and developed to blastocysts (44.0% and 11.2%), although the rates were significantly (P < 0.01) lower than those in control (71.7% and 35.0%). These results indicate that stepwise dilution of frozen–thawed oocytes improves the recovery of oocytes with normal morphology, and that the oocytes maintain the abilities to be fertilized and develop to blastocysts.

181 DIFFERENCES EXIST IN ZONA PELLUCIDA HARDNESS BETWEEN IN VIVO- AND IN VITRO-GENERATED BOVINE EMBRYOS

The zona pellucida (ZP) of mammalian ova plays an important role during maturation, fertilization, and early embryonic development. The hardness of ZP of mammalian ova has been mainly evaluated by a biochemical method, such as a difference in ova dissolution speed with an enzyme or an acid reagent treatment. However, the physical hardness of ZP in bovine embryos is largely unknown. Recently, we developed a system measuring the physical hardness of ZP of mammalian ova with a micro bio-sensor (MBS). The objective of this study was to examine the physical ZP hardness of in vivo- and in vitro-derived bovine embryos using an MBS. In the measurement system, the thin glass needle was connected at the tip of a piezo-electric ceramic tactile sensor, and the sample was pushed into a sensor at fixed speed under the computer-controlled micromanipulation system. The change in frequency at the time of displacement of the sample into the sensor was recorded using the computer program. Measurement of gelatin samples of known concentration (4 to 8%) was used to determine the basic characteristic of a sensor and to make a standard curve. In vivo-generated embryos were recovered from 6 superovulated Japanese Black cows with multiple injection of FSH. On Day 7 after insemination, morulae (M), early blastocysts (EB), and blastocysts (BL) were recovered by nonsurgical flushing of uterine horns. In vitro-generated embryos were produced as described earlier (Yoshida et al. 1998 J. Vet. Med. Sci. 60, 549–554). The M, EB, and BL at Days 5 to 7 of post-insemination in vitro were used for measurement of ZP hardness. When a sensor made contact with a harder gelatin sample, the change in frequency was large; the change in frequency has the characteristic of being small for a softer gelatin sample. By comparison with a standard curve, ZP hardness converted into gelatin concentration for each stage of bovine embryos generated in vivo was 3.95% (M: n = 9), 4.14% (EB: n = 32), and 3.92% (BL: n = 14), respectively. On the other hand, ZP hardness of bovine embryos generated in vitro was 3.42% (M: n = 56), 3.33% (EB: n = 36), and 3.25% (BL: n = 23), respectively. There was a significant difference (P < 0.01) in the hardness of ZP between in vivo- and in vitro-generated bovine embryos.

Analysis of corneal inflammation induced by cauterisation in CCR2 and MCP-1 knockout mice

AIM

To elucidate the role of CCR2/MCP-1 in corneal inflammation.

METHODS

A cauterisation induced corneal inflammation model was used. The corneas were cauterised with silver nitrate in CCR2 knockout (KO) mice, MCP-1 KO mice, and control mice. Clinical signs such as corneal oedema and opacity were examined 96 hours after cauterisation and the phenotypes of the cells infiltrating the cornea were analysed by flow cytometry. Corneal inflammation in neutrophil depleted mice was also analysed.

RESULTS

After cauterisation both CCR2 KO and MCP-1 KO mice showed the same levels of corneal oedema and opacity as control mice. Flow cytometry revealed that in control mice most of the infiltrating cells were neutrophils and macrophages, whereas in both CCR2 KO mice and MCP-1 KO mice, the number of macrophages infiltrating the cornea were markedly reduced. However, prominent infiltrates of neutrophils were still observed in the cornea in CCR2 KO mice and MCP-1 KO mice. The depletion of neutrophils significantly reduced the oedema and opacity induced in the cornea by cauterisation.

CONCLUSION

The CCR2 and MCP-1 molecules are not essential for cauterisation induced corneal inflammation. Neutrophils, rather than migrated macrophages, are the final effector cells involved in inducing inflammation in this model.

Gene expression of glucose transporter (GLUT) 1, 3 and 4 in bovine follicle and corpus luteum

Glucose is the main energy substrate in the bovine ovary, and a sufficient supply of it is necessary to sustain the ovarian activity. Glucose cannot permeate the plasma membrane, and its uptake is mediated by a number of glucose transporters (GLUT). In the present study, we investigated the gene expression of GLUT1, 3 and 4 in the bovine follicle and corpus luteum (CL). Ovaries were obtained from Holstein x Japanese Black F1 heifers. Granulosa cells and theca interna layers were harvested from follicles classified into five categories by their physiologic status: follicular size (>or= 8.5 mm: dominant; < 8.5 mm: subordinate), ratio of estradiol (E(2)) to progesterone in follicular fluid (>or= 1: E(2) active;<1: E(2) inactive), and stage of estrous cycle (luteal phase, follicular phase). CL were also classified by the stage of estrous cycle. Expression levels of GLUT1, 3 and 4 mRNA were quantified by a real-time PCR. The mRNA for GLUT1 and 3 were detected in the bovine follicle and CL at comparable levels to those in classic GLUT-expressing organs such as brain and heart. Much lower but appreciable levels of GLUT4 were also detected in these tissues. The gene expression of these GLUT showed tissue- and stage-specific patterns. Despite considerable differences in physiologic conditions, similar levels of GLUT1, 3 and 4 mRNA were expressed in subordinate follicles as well as dominant E(2)-active follicles in both luteal and follicular phases, whereas a notable increase in the gene expression of these GLUT was observed in dominant E(2)-inactive follicles undergoing the atretic process. In these follicles, highly significant negative correlations were observed between the concentrations of glucose in follicular fluid and the levels of GLUT1 and 3 mRNA in granulosa cells, implying that the local glucose environment affects glucose uptake of follicles. These results indicate that GLUT1 and 3 act as major transporters of glucose while GLUT4 may play a supporting role in the bovine follicle and CL.

137 EFFECT OF FLUNIXIN MEGLUMINE IN CO-CULTURE MEDIUM ON THE DEVELOPMENT OF IN VITRO MATURED AND FERTILIZED BOVINE EMBRYOS

PG concentration is often increased during uterine manipulation with embryo transfer. Embryo viability is affected by the increase in the PGF2α concentration accompanying manipulation of the uterus during embryo transfer. Schrick et al. (2001 Theriogenology 55, 370 abst) observed that treatment with flunixin meglumine, an inhibitor of prostaglandin, increased pregnancy rates depending on the stage and quality of embryos transferred. On the other hand, prostaglandin was secreted by a cumulus cell monolayer in an in vitro culture of bovine oocytes. The present study aimed to assess the effects of flunixin meglumine in culture medium on the development of in vitro-matured and fertilized bovine embryos. COCs were collected from ovaries of slaughtered cows by aspiration. The COCs were matured for 20 h in TCM-199 supplemented with 5% fetal bovine serum (FBS) and antibiotics at 38.5°C under an atmosphere of 2% CO2 in air. Matured COCs were inseminated with 1.0 × 107 sperm mL−1 in BO medium (Brackett and Oliphant 1975 Biol. Reprod. 12, 260–274) containing 5 mM theophillin and 5 μg mL−1 heparin for 5 h. All of the inseminated oocytes were introduced into the maturation medium that had been kept with the cumulus cells in the CO2 incubator. At 48 h after insemination, all embryos over the 4-cell stage were cultured in TCM-199 plus 5% FBS supplemented with each of five concentrations of flunixin meglumine (0, 0.0025, 0.005, 0.01, and 0.025%) with a cumulus cell monolayer. Development to the blastocyst stage and quality were examined at Days 7 to 8 (Day 0 = day of insemination) using a microscope. The experiment was replicated four times. Data were analyzed by the chi-square test. The total blastocyst rates from the over-4-cell embryos were 61.2 (52/89), 53.7 (44/89), 65.6 (59/90), 57.3 (51/89), and 33.7% (31/92) for 0, 0.0025, 0.005, 0.01, and 0.025%, flunixin meglumine, respectively. The total blastocyst rate with the flunixin meglumine concentration of 0.025% was significantly lower than those with the other concentrations (P < 0.05). The proportion of grade 1 blastocysts with the flunixin meglumine concentration of 0.005% was significantly higher than that with the 0, 0.0025, and 0.025% concentrations (27.8 vs 11.2, 14.6, and 5.4%; P < 0.05). Our present results show that the addition of 0.005% flunixin meglumine to the co-culture medium is positively associated with blastocyst quality in bovine embryos.

The relative contributions of each subset of ocular infiltrated cells in experimental choroidal neovascularisation

AIM

Choroidal neovascularisation (CNV) is a major cause of blindness in adults. The aim of this study was to investigate the role of infiltrating cells in the development of experimental CNV.

METHODS

CNV was induced in C57BL/6 (B6) mice by laser photocoagulation (PC). After PC, the numbers of each subset of infiltrated cells were analysed by flow cytometry at multiple time points. Each subset (except for macrophages) was depleted by the specific antibodies in vivo. Thereafter, the area of CNV was compared between the control B6 mice and the specific antibody treated mice 7 days after PC. The CNV formation in neutrophil depleted CC chemokine receptor-2 (CCR2) knockout mice was also examined to minimise the effects of macrophages.

RESULTS

In the early phase of CNV formation, a large number of neutrophils and macrophages infiltrated to the eyes. Natural killer (NK) cells and T lymphocytes were barely detected while no B lymphocytes were detected. The CNV areas did not significantly change compared between the control B6 mice and the specific antibody treated mice. However, the neutrophil depleted CCR2KO mice resulted in a reduction of CNV.

CONCLUSION

Although lymphocytes and NK cells had little effect on CNV formation, neutrophils partially contributed to CNV in the absence of macrophages.

IL-18 gene therapy develops Th1-type immune responses in Leishmania major-infected BALB/c mice: is the effect mediated by the CpG signaling TLR9?

IL-18 regulates either Th1 or Th2 responses depending on the cytokine microenvironment. Administration of recombinant IL-18 (rIL-18) alone does not promote Th1 response, but rather induces Th2 response and exacerbates Leishmania major infection in susceptible BALB/c mice. Here, we treated BALB/c mice with an IL-18-expressing plasmid by using a gene gun weekly after L. major infection. This gene therapy resulted in improved pathogenic process and preferential induction of Th1 responses by inducing the expression of IL-12 p40, but treatment with rIL-18 did not. Notably, simultaneous administration of rIL-18 with an empty plasmid vector rendered BALB/c mice resistant to the infection, despite the fact that treatment with either rIL-18 alone or the plasmid vector alone did not influence the susceptibility. The synergistic role of the vector with rIL-18 was found to depend on CpG motifs, which enhanced expression of proinflammatory cytokines, especially IL-12, from APCs through Toll-like receptor (TLR) 9 ligation. Treatment with methylated plasmid vector in which CpG was disrupted could no longer prevent the disease development in coadministration with rIL-18. Taken together, IL-18 gene therapy was shown to develop Th1-type protective immunity in L. major-infected BALB/c mice without the requirement of exogenous IL-12, probably via CpG-TLR9 signaling pathway.

Strongyloides ratti: the role of interleukin-5 in protection against tissue migrating larvae and intestinal adult worms

To determine the role of interleukin-5 (IL-5) and eosinophils in protection against Strongyloides ratti, mice treated with anti-IL-5 monoclonal antibody (mAb) were infected with S. ratti larvae. Strongyloides ratti egg numbers in faeces (EPG) in mAb treated mice were higher than those in control mice on days 6 and 7 after inoculation. The numbers of migrating worms in mAb treated mice 36 h after inoculation were higher than those observed in control mice. Intestinal worm numbers in mAb treated mice 5 days after inoculation were higher than those in control mice. These results show that eosinophils effectively protected the host against S. ratti infection by mainly the larval stage in primary infections. The involvement of eosinophils in protection against secondary infection was also examined. Before secondary infection, mice were treated with anti-IL-5 mAb and infected with S. ratti. Patent infections were not observed in either mAb treated or control Ab treated mice. The numbers of migrating worms in the head and lungs of mAb treated mice increased to 60% of that in primary infected mice. Intestinal worms were not found in mAb treated mice or in control mice after oral implantation of adult worms. Eosinophils were therefore mainly involved in protection against tissue migrating worms in secondary infections.

97EFFECT OF RAPID TEMPERATURE CHANGE ON VIABILITY OF FROZEN-THAWED IVM/IVF BOVINE EMBRYOS

In on-farm conditions, frozen bovine embryos are frequently thawed at various environmental temperatures. Thawing temperature is an important factor affecting the viability of frozen-thawed bovine embryos. The present study investigated the effects of rapid temperature change on the viability of frozen IVM/IVF bovine embryos after thawing. Day 7- and 8- (Day 0=day of insemination) expanded blastocysts were used in this study. Embryos were produced as previously described by Hamano &amp; Kuwayama (1993 Theriogenology 39, 703–712,). Embryos were frozen in TCM-199 supplemented with 1.4M glycerol, 20% calf serum (CS), and 0.25-M sucrose. The embryos were loaded into 0.25mL straws. After equilibration, the straws were placed directly into a precooled alcohol chamber of a freezer at −6°C, seeded 1min later, held at −6°C for 10min, cooled to −25°C at a rate of 0.33°C/min, and then plunged into liquid nitrogen. Embryos were thawed by holding the straws in room temperature air for 10s, and then immersing them in a 35°C water bath for 10s. The thawed straws were randomly assigned to one of two groups. Some thawed straws were held for 5min at −15, −5, 0, 5, or 15°C, and were then transferred directly into a water bath at 35°C for 5min (Group 1). The remaining straws were subjected to the same post-thaw cooling step procedures as Group 1 two times (Group 2). The embryos were then directly rehydrated in PBS supplemented with 5% CS at 35°C, and cultured in TCM-199 supplemented with 5% CS and 0.1mM β-mercaptoethanol. The morphology and hatching of embryos was assessed 72h later. Data were analyzed using the chi-square method and Fisher’s exact test. The results are presented in the Table. There were no significant differences in the hatching rate among 5 temperatures in Group 1. Although there were no differences in the hatching rate of embryos held at −5, 0, 5, or 15°C after thawing, the rate for embryos held at −15°C was significantly lower than those of the other treatments in Group 2 (P&lt;0.05). The straws held at −15°C twice (Group 2), showed refreezing. These results suggest that exposing thawed straws to a broad range of environmental temperatures (−5 to 15°C) had no effect on the viability of frozen-thawed IVM/IVF bovine embryos. However, embryos might be irreversibly damaged when held at −15°C. Table 1 Effect of rapid temperature change on the viability of frozen-thawed IVM/IVF bovine embryos

168FACTORS AFFECTING ON EMBRYO TRANSFER PREGNANCY RATES OF IN VITRO-PRODUCED BOVINE EMBRYOS

The objective of this study was to analyze factors affecting the pregnancy rates after transfer of IVF-derived Japanese Black embryos. Holstein cows and heifers (n=7250) were selected as recipients, and embryo transfers were performed for 3yr (between 1998 and 2000). The IVM-IVF procedure was performed according to a method previously described (Hamano S and Kuwayama M 1993 Theriogenology 39, 703–712). IVF-derived embryos that developed into expanded blastocysts (grade 1, manual of IETS) after 7 to 8 days (insemination=Day 0) were used for this study. Some of these embryos were frozen in TCM-199 supplemented with 1.4M glycerol, 20% calf serum, and 0.25M sucrose. The embryos were seeded at −6°C, held at −6°C for 10min, and then cooled to −25°C at a rate of 0.33°Cmin−1. Frozen embryos were thawed in a 30 to 35°C water bath after 10s of air thawing. Fresh (n=3952) or frozen-thawed (n=3298) embryos were nonsurgically transferred to recipients on Days 6 to 9 of the estrous cycle. Data collected at the time of embryo transfer included recipient parity (cow or heifer), whether recipient estrus was natural or synchronized with PGF2α, cloprostenol or CIDR, methods of estrous confirmation (showing standing heat, rectal palpation of ovary without standing heat, or showing only mucous vulvular discharge), number of examinations of the CL by palpation per rectum (twice on the day before embryo transfer and the day of embryo transfer, or once on the day of embryo transfer), type of embryos (fresh or frozen), and day of the estrous cycle at the time of embryo transfer. CATMOD procedures of SAS were used to determine the factors affecting the pregnancy rate. Overall pregnancy rates were 37.3% (n=2704). Whether recipient estrus was natural or synchronized and the type of embryos did not influence the pregnancy rates. Heifers had significantly higher pregnancy rates than cows (44.0% v. 33.0%, respectively, P&lt;0.05). Pregnancy rates among the subset of heifers and cows showing standing heat were significantly higher than those showing only mucous vulvular discharge (39.5% v. 33.5%, respectively, P&lt;0.05). Examining the CL twive had a significantly higher pregnancy rate than did a single examination of the CL (41.1% v. 35.6%, respectively, P&lt;0.05). Pregnancy rate on Day 8 (38.4%, 1358/3533) of the estrous cycle at the time of embryo transfer was significantly higher than on Days 6 (27.7%, 23/83) and 7 (36.2%, 1235/3408) (P&lt;0.05), and the pregnancy rate on Day 6 of the estrous cycle at the time of embryo transfer tended to be lower than on Day 9 (38.9%, 88/226) (P&lt;0.08). These results demonstrate that confirming standing heat, performing CL examination twice before embryo transfer, freezing high quality embryos, and performing embryo transfers on Day 8 resulted in an improved pregnancy rate for the transfer of IVF-derived embryos.

High expression of the novel endothelin-converting enzyme genes, Nbla03145/ECEL1alpha and beta, is associated with favorable prognosis in human neuroblastomas

The clinicobiological feature of neuroblastoma is enigmatic because spontaneous regression often occurs in early stages of tumors of the patients under 1 year of age, while rapid growth usually occurs in the tumors of the patients over 1 year of age. Such difference in the clinical behavior may be caused by the difference in the pattern of gene expression among the subsets of neuroblastoma. To understand the molecular basis of neuroblastoma biology, we decided to identify the novel genes expressed differentially between favorable and unfavorable neuroblastomas. The oligo-capping cDNA libraries were constructed from different subsets of neuroblastomas. After random selection and DNA sequencing, the differentially expressed genes between favorable and unfavorable neuroblastomas were screened by reverse transcriptase-PCR. The clinical significance of gene expression was evaluated based on the results of Northern blot analysis. We have identified a novel gene Nbla03145 (alpha), also cloned and termed by another group as ECEL1, which encodes a new member of putative zinc-binding metalloendopeptidase (endothelin-converting enzyme) with unknown substrate. We also cloned a COOH-terminally truncated Nbla03145/ECEL1beta which is expressed only in thymus. In primary NBLs, the alpha isoform is more preferentially expressed than the beta isoform. High levels of Nbla03145/ECEL1 expression were significantly correlated with a younger age (p=0.0005), lower stages (p=0.0019), high level of TrkA expression (p</=0.00005), a single copy of MYCN (p<0.00005) and the tumors found by mass screening (p<0.00005). Decreased expression of Nbla03145/ECEL1 mRNA was significantly associated with poor prognosis (log-rank test: p=0.012). The present results have shown that expression of Nbla03145/ECEL1 is a novel prognostic marker of neuroblastoma. Further analysis of the gene may also give a cue to the understanding of the role of endothelin-like signaling in neuroblastoma and to the development of diagnostic and therapeutic strategies against aggressive tumors.