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M Arai

Publications and source records attributed to M Arai.

At least 55 records · Page 3Linked to original sources
PubMed2001

Clinical trial to investigate the pharmacokinetics, pharmacodynamics, safety, and efficacy of recombinant factor VIIa in Japanese patients with hemophilia with inhibitors.

A multicenter and open-labeled clinical trial of human recombinant factor VIIa (rFVIIa) was conducted in Japanese patients with severe hemophilia A or B with inhibitors. The trial consisted of 2 parts. In study 1, the pharmacokinetics, pharmacodynamics, and safety of a single dose of 120 microg/kg of rFVIIa were investigated in 8 patients. In the subsequent study 2, the hemostatic effect and safety of rFVIIa were evaluated during a 24-week period in 10 patients. In study 1, the mean maximum FVII-coagulant activity (FVII:C) was found to occur after 10 minutes; activity then decreased rapidly and returned to the baseline within 24 hours after a single intravenous infusion of rFVIIa. The mean half-life of FVII:C was 3.5 hours. The activated partial thromboplastin time and prothrombin time in the patients were immediately shortened but returned to the baseline within 24 hours after dosing. In study 2, 86 microg/kg to 120 microg/kg of rFVIIa (mean, 97 microg/kg) was administered 1 to 85 times to 10 patients. A total of 58.0% (91/157) of bleeding episodes were treated excellently or effectively, with 5 (3.2%) ineffective episodes. There was no apparent trend in the relationship of the hemostatic effect with bleeding sites, mean dose, or number of injections. The efficacy rate, however, was significantly higher (90.0%) in bleeding episodes treated within 3 hours than in those treated at longer intervals (31.0%). No treatment-related adverse events were observed, and there was no evidence of antibody formation to rFVIIa. In conclusion. rFVIIa is an effective and well-tolerated option for treatment of bleeding episodes in hemophilia patients with inhibitors.

Adolescent↗
PubMed2001

Serum acid phosphatase as a tumour marker in giant cell tumour of bone.

The serum acid phosphatase value was examined in nine patients with giant cell tumour of bone. Five showed a high level of acid phosphatase, which fell to within normal limits after surgery. Although the remaining four patients showed a normal acid phosphatase level before surgery, the postoperative acid phosphatase level was lower than the preoperative level in each case. Therefore, it is strongly suggested that serum acid phosphatase is a useful tumour marker in diagnosing giant cell tumour of bone as well as in evaluating the efficacy of treatment.

Acid Phosphatase↗
PubMed2001

Penile agenesis complicated by Potter sequence.

We present a case of penile agenesis complicated by multicystic dysplastic kidneys and urethral agenesis, which resulted in oligohydramnios, pulmonary hypoplasia and neonatal death. In this case, no external urethral opening was found, and the gastrointestinal tract showed no anomaly. Cases of penile agenesis complicated by Potter sequence with urethral agenesis should be differentiated from those with ectopic urethral openning.

Fatal Outcome↗
PubMed2001

Adenocarcinoma of the nonpigmented ciliary epithelium: report of two cases with immunohistochemical findings.

BACKGROUND: Acquired neoplasms arising from the nonpigmented ciliary epithelium (NPCE) are much less common than uveal melanocytic proliferations. We report two cases of acquired neoplasms arising from the NPCE with immunohistochemical findings. METHODS: Case reports. RESULTS AND CONCLUSIONS: Patient 1 was a 39-year-old man who presented with a pigmented mass behind the iris and secondary exudative retinal detachment. The eye also developed neovascular glaucoma. Patient 2 was a 44-year-old woman with a ciliary body mass but without symptoms. Both of these tumors were classified histologically as low-grade adenocarcinomas of the NPCE from specimens successfully removed by iridocyclectomy. Immunohistochemical findings confirmed the origin of the tumor cells; however, some changes in the immunoreactivity to cytokeratin AE1 and epithelial membrane antigen were found.

Adenocarcinoma↗
PubMed2001

Combined effect of retinoic acid and basic FGF on PAI-1 gene expression in vascular smooth muscle cells.

OBJECTIVE: Aberrant regulation of the synthesis and degradation of the extracellular matrix (ECM) is associated with the pathophysiology of vascular disease. Plasminogen activator inhibitor-1 (PAI-1) plays a crucial role in regulating the quantity and composition of ECM. However, regulatory mechanisms underlying the expression of the PAI-1 gene remain unclear. We examined the effects of all-trans-retinoic acid (atRA), either alone or in combination with mitogenic growth factor, basic fibroblast growth factor (bFGF), on the PAI-1 expression in cultured vascular smooth muscle cells (SMCs). METHODS: Cultures of the rabbit vascular smooth muscle cell line C2/2 were used to study the effects of atRA and bFGF separately or together. RESULTS: Treatment of vascular SMCs with atRA in combination with bFGF resulted in an additional increase in PAI-1 expression both at the mRNA and protein levels. In contrast, tissue-type plasminogen activator, urokinase-type plasminogen activator and tissue factor mRNA levels were only minimally affected. The all-trans-RA- and bFGF-mediated increases in PAI-1 mRNA levels were markedly attenuated by the tyrosine kinase inhibitor genistein, but not by MEK1 or p38MAP kinase inhibitors. The rate of decrease in PAI-1 mRNA levels after actinomycin D treatment was not affected by atRA and bFGF. Transient transfection of the PAI-1 promoter-luciferase reporter gene, which contains 967 bp of the 5'-flanking region of the human PAI-1 gene, revealed that atRA and bFGF additionally increased transcription from this promoter. Progressive 5'-deletion revealed that the promoter region required for such an effect lies between -967 and -260, which contains no canonical sequence for the RA-response element. In agreement with the role of PAI-1 in the inhibition of fibrinolytic activity which stimulates ECM degradation, cell migration was inhibited by treatment with atRA and bFGF. CONCLUSIONS: These results indicate that atRA and bFGF can function in a combined fashion and induce PAI-1 synthesis in vascular SMCs, and suggest a role for these two compounds in regulating SMC migration.

Analysis of Variance↗
PubMed2001

Analysis of photochemical pollution in summer and winter using a photochemical box model in the center of Tokyo, Japan.

In order to give an effective and rapid analysis of the photochemical pollution and information for emission control strategies, a photochemical box model (PBM) was applied to one moderate summer episode, 11 July 1996, and one typical winter episode, 3 December 1996, in the center of Tokyo, Japan. The box model gave a good prediction of the photochemical pollution with minimal investment. As expected, the peak ozone in summer is higher than in winter. The NOx concentrations in winter are higher than those in summer. In summer, NO and NO2 have one peak in the morning. In winter, NO and NO2 show two peaks during the day. Three model runs including no reactions, a zero ozone boundary condition and dark reactions were conducted to understand the photochemical processes. The effects of emission reduction on the formation of the photochemical pollution in the center of Tokyo have been studied. The results show that the reduction of NMHC emission can decrease the ozone, however, the reduction of NOx emission can increase the ozone. It can be concluded that if the NOx emission are reduced, the reduction of NMHC should be more emphasized in order to decrease the ozone concentration in the center of Tokyo, Japan, especially the reduction of the NMHC from stationary source emission.

Air Pollution↗
PubMed2001

Both mosquito-derived xanthurenic acid and a host blood-derived factor regulate gametogenesis of Plasmodium in the midgut of the mosquito.

Gametogenesis of Plasmodium in vitro can be induced by the combined stimulus of a 5 degrees C fall in temperature and the presence of xanthurenic acid (XA). In-vitro experiments showed that P. gallinaceum (EC(50)=80 nM) is much more sensitive to XA than P. berghei (9 microM), P. yoelii (8 microM), and P. falciparum (2 microM). However, in the mosquito vector, we do not know whether the temperature shift and XA are the only gametocyte-activating factors (GAF), nor do we know with certainty the true source(s) of XA in the mosquito blood meal. Previous studies indicate that XA is the only source of GAF in the mosquito. By defining, and then contrasting, the ability of an XA-deficient mutant of Aedes aegypti, with the wild-type mosquito to support exflagellation and ookinete formation in vivo, we determined the roles of parasite-, mosquito- and host blood-derived GAF in the regulation of gametogenesis of P. gallinaceum. Removal of both host and vector sources of GAF totally inhibited both exflagellation and ookinete production, whilst the lack of either single source resulted in only a partial reduction of exflagellation and ookinete formation in the mosquito gut. Both sources can be effectively replaced/substituted by synthetic XA. This suggests (1) both mosquito- and vertebrate-derived factors act as GAF in the mosquito gut in vivo; (2) the parasite itself is unable to produce any significant GAF activity. Studies are underway to determine whether vertebrate-derived GAF is XA. These data may form the basis of further studies of the development of new methods of interrupting malarial transmission.

Aedes↗
PubMed2001

Dynamic change of cells expressing MMP-2 mRNA and MT1-MMP mRNA in the recovery from liver fibrosis in the rat.

BACKGROUND/AIMS: The aim of this study was to investigate whether both matrix metalloproteinase-2 (MMP-2) and membrane type 1 MMP (MT1-MMP) participate in the spontaneous resolution of liver fibrosis. METHODS: Transcription of both genes was examined by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization (ISH). Gelatinase activity was investigated by zymography. RESULTS: Gene expression by RT-PCR showed that both genes increased in the process of liver fibrosis, then decreased gradually in the recovery phase. ISH revealed that distribution of positive cells changed quickly in the recovery phase. Positive cells were widely seen in the liver, mainly around fibrous septa, in the aggressive phase, but were exclusively observed at the interface between the resolving fibrous band and the parenchyma, then were diffusely located in the lobules in the recovery phase. Main cells expressing both mRNAs seemed to be stellate cells for their morphology, though they did not express characteristic cell markers. Some hepatocytes and Kupffer cells expressed both mRNAs in the recovery phase. Gelatinase activity of MMP-2 increased in the recovery phase of 8-week-treated rat liver by gelatin zymography. CONCLUSIONS: The results of present study suggest that both enzymes participate in the destruction of extracellular matrix in coordination with MMP-13.

Animals↗
PubMed2001

Noninvasive quantitative tissue characterization and two-dimensional color-coded map of human atherosclerotic lesions using ultrasound integrated backscatter: comparison between histology and integrated backscatter images.

OBJECTIVES: The purpose of the present study was to define clinicopathologically whether integrated backscatter (IB) combined with conventional two-dimensional echo (2DE) can differentiate the tissue characteristics of calcification (CL), fibrosis (FI), lipid pool (LP) with fibrous cap, intimal hyperplasia (IH) and thrombus (TH) and can construct two-dimensional tissue plaque structure in vivo. BACKGROUND: It is difficult to characterize the components of plaque using conventional 2DE techniques. METHODS: Integrated backscatter values of plaques were measured in the right common carotid and femoral arteries (total 24 segments) both during life and after autopsy in 12 patients (age 68 to 84 years, 10 men and two women). Integrated backscatter values were determined using a 5-12 MHz multifrequency transducer, setting the region of interests (ROIs) (11 x 11 pixels) on the echo tomography of the entire arterial wall (55 +/- 10 ROI/segment) and comparing it with histologic features in the autopsied arterial specimens. RESULTS: Corrected IB values obtained before death and at autopsy were significantly correlated (r = 0.93, p < 0.01). Corresponding to the histologic features, corrected IB values on the rectangle ROIs obtained during life were divided into five categories: category 1 (TH) 4 < IB < or = 6; category 2 (media and IH or LP in the intima) 7 < IB < or = 13; category 3 (FI) 13 < IB < or = 18, category 4 (mixed lesion) 18 < IB < or = 27 and category 5 (CL) 28 < IB < or = 33. In category 2, media and intima were differentiated using conventional 2DE. Under the above procedures, color-coded maps constructed with IB-2DE obtained during life precisely reflected the histologic features of media and intima. CONCLUSIONS: Integrated backscatter with 2DE represents a useful noninvasive tool for evaluating the tissue structure of human plaque.

Aged↗
PubMed2001

Interleukin-2-dependent but not independent T-cell lines infected with human T-cell leukemia virus type 1 selectively express CD45RO, a marker for persistent infection in vivo.

Human T-cell leukemia virus type 1 (HTLV-1) is an etiologic agent of adult T-cell leukemia. HTLV-1 is exclusively detected in CD45RO+ T-cells in infected individuals, but CD45RO is weakly expressed in HTLV-1-transformed T-cell lines in vitro. The aim of this study was to investigate the role of CD45RO in the persistent HTLV-1 infection in vivo. Flow cytometry showed that only two out of eight interleukin(IL)-2-independent HTLV-1-transformed T-cell lines expressed CD45RO, whereas all five IL-2-dependent ones expressed CD45RO, and the level of expression was higher in IL-2-dependent than in IL-2-independent cells. The high CD45RO expression in IL-2-dependent cell lines was not due to IL-2, since IL-2 had little effect on the expression of CD45RO in T-cell lines. Using western blotting, we showed that IL-2-dependent HTLV-1-transformed T-cell lines expressed a lower level of expression of the viral transcriptional regulatory protein Tax than IL-2-independent ones, and that the level of expression correlated inversely with that of CD45RO. However, the expression of Tax in one HTLV-1-negative T-cell line little affected the expression of CD45RO, suggesting that Tax at least alone does not suppress the expression of CD45RO in HTLV-1-infected T-cell lines, and that other viral or cellular factor(s) are probably involved in such suppression. Our results suggest that CD45RO+ Tax-low IL-2-dependent T-cell lines in vitro correspond to the persistent HTLV-1-infected cells in vivo, and HTLV-1-infected cells in vivo are immortalized in IL-2-dependent manner.

Cell Line↗
PubMed2001

Electroretinogram contact lens electrode with tri-color light-emitting diode.

PURPOSE: This study was performed to evaluate a new electroretinogram (ERG) contact lens electrode containing four light-emitting diodes (LEDs) that are used for both stimulus and background light. METHODS: The luminance of each LED could be changed independently and used as stimulus light. Red, blue, bright white, and flickering ERGs were recorded in 12 normal subjects and two patients with progressive cone dystrophy. The long-duration light stimuli separated the on- and off-responses of the ERG. This equipment is not according to the ISCEV standard. RESULTS: The tri-color LED electrode contact lens can efficiently produce and record ERG responses. Off-responses were recordable separately from on-responses by lengthening the stimulus duration. CONCLUSION: This combined stimulus-electrode system is compact and portable. Combined with the portable amplifier and the recorder, the ERGs can be recorded easily in an operating room, at patients' bedside, and in remote locations away from clinics and hospitals.

Adult↗
PubMed2001

Role of protein kinase C in the reduction of infarct size by N-methyl-1-deoxynojirimycin, an alpha-1,6-glucosidase inhibitor.

Preischaemic treatment with N-methyl-1-deoxynojirimycin (MOR-14), an alpha-1,6-glucosidase inhibitor, attenuates glycogenolysis and lactate accumulation during ischaemia and markedly reduces infarct size in rabbit hearts. In the present study, we have investigated whether protein kinase C (PKC), a principal mediator of ischaemic preconditioning, is also involved in the cardioprotective effect of MOR-14. To assess the effect of PKC inhibition on infarct size in MOR-14-treated hearts, 38 rabbits were subjected to 30 min of ischaemia followed by 48 h of reperfusion. Infarct size, as a per cent of area at risk, was significantly smaller in rabbits administered 100 mg kg(-1) of MOR-14 10 min before ischaemia (17+/-2%, n=10), than in a control group (46+/-5%, n=10). This beneficial effect of MOR-14 was abolished when 5 mg kg(-1) of chelerythrine, a PKC inhibitor, was given 10 min prior to MOR-14 injection (39+/-4%, n=10), although chelerythrine alone did not alter infarct size (43+/-4%, n=8). Further, chelerythrine had no effect on MOR-14-induced attenuation of glycogen breakdown and lactate accumulation in hearts excised at 30 min of ischaemia. Immunoblot analysis of PKC in homogenates of Langendorff-perfused rabbit hearts revealed that MOR-14 significantly increased levels of PKC-epsilon in the particulate fraction at 20 and 30 min of ischaemia and in the cytosolic fraction at 30 min of ischaemia. Taken as a whole, our data suggest that PKC acts downstream of the inhibition of glycogenolysis by MOR-14 to reduce infarct size. Thus, activation of PKC is a more direct mediator of the cardioprotection afforded by MOR-14 than is inhibition of glycogenolysis.

1-Deoxynojirimycin↗
PubMed2001

Combination of miglitol, an anti-diabetic drug, and nicorandil markedly reduces myocardial infarct size through opening the mitochondrial K(ATP) channels in rabbits.

The anti-diabetic drug miglitol, an alpha-glucosidase inhibitor, which is currently used clinically, reduces myocardial infarct size by reducing the glycogenolytic rate through inhibition of the alpha-1,6-glucosidase of glycogen-debranching enzyme in the heart. Nicorandil, a K(ATP) channel opener with a nitrate-like effect, which is also currently used clinically, also reduces the infarct size. Therefore, we hypothesized that combination of nicorandil and submaximal dose of miglitol could markedly reduce myocardial infarct size more than miglitol or nicorandil alone, and investigated the mechanism for the infarct size-reducing effect. Japanese white rabbits without collateral circulation were subjected to 30 min coronary occlusion followed by 48 h reperfusion. Pre-ischaemic treatment with submaximal dose of miglitol (5 mg kg(-1), i.v.) and nicorandil alone (100 microg kg(-1) min(-1) 5 min) moderately reduced the infarct size as a percentage of area at risk (24+/-4 and 25+/-4%, respectively), and 10 mg kg(-1) of miglitol markedly reduced the infarct size (15+/-2%) compared with the controls (42+/-2%). Combination of 5 mg kg(-1) of miglitol and nicorandil (100 microg kg(-1) min(-1) 5 min), and 10 mg kg(-1) of miglitol and nicorandil (100 microg kg(-1) min(-1) 5 min) significantly reduced the infarct size (13+/-4 and 12+/-3%, respectively) more than miglitol or nicorandil alone. Pretreatment with 5HD completely abolished the infarct size-reducing effect of 10 mg kg(-1) of miglitol alone (36+/-7%) and that of combination of 5 mg kg(-1) of miglitol and nicorandil (46+/-2%). Combination of nicorandil and submaximal dose of miglitol markedly reduced the myocardial infarct size more than miglitol or nicorandil alone. This effect was suggested to be related to the opening of mitochondrial K(ATP) channels.

1-Deoxynojirimycin↗
PubMed2001

Role of protein kinase C, K(ATP) channels and DNA fragmentation in the infarct size-reducing effects of the free radical scavenger T-0970.

1. In the present study, we investigated the effect of 1-(3-tert-butyl-2-hydroxy-5-methoxyphenyl)-3-(3-pyridylmethyl) urea hydrocloride (T-0970), a novel water-soluble low-molecular weight free radical scavenger, on the generation of hydroxyl radicals in vivo and on myocardial infarct size in an in vivo model of myocardial infarction in rabbits. 2. T-0970 scavenged hydroxyl radicals generated in the myocardium during reperfusion, as assessed by using a microdialysis technique and HPLC in an in vivo model with 30 min coronary occlusion and 30 min reperfusion in rabbits. 3. Another group of rabbits was subjected to 30 min coronary occlusion and 48 h reperfusion. The control group (n = 10) was infused with saline for 190 min from 10 min before occlusion to 180 min after reperfusion. The treatment group (T-0970 group; n = 10) was injected with a bolus 2.5 mg/kg T-0970 and then infused with T-0970 for 190 min from 10 min before reperfusion to 180 min after reperfusion at a rate of 100 microg/kg per min. The T-0970 + CHE group (n = 5) was given chelerythrine (CHE; a selective inhibitor of protein kinase C (PKC); 5 mg/kg, i.v.) 10 min before the administration of T-0970. The T-0970 + 5-HD group (n = 5) was given 5-hydroxydecanoate (5-HD; an inhibitor of mitochondrial K(ATP) channels; 5 mg/kg, i.v.) 10 min before the administration of T-0970. The CHE and 5-HD groups were given CHE (5 mg/kg, i.v.) and 5-HD (5 mg/kg, i.v.) 20 min before reperfusion, respectively. After 48 h reperfusion, infarct size was measured histologically and expressed as a percentage of the area at risk (AAR). In another series of experiments, the control (n = 5) and T-0970 (n = 5) groups were killed 4 h after reperfusion following 30 min coronary occlusion and DNA fragmentation in myocytes was assessed using in situ dUTP nick end-labelling (TUNEL) at the light microscopic level. 4. Infarct size, as a percentage of AAR, in the T-0970 group was significantly reduced compared with the control group (21+/-4 vs 41+/-4%, respectively; P<0.05). This reduction of infarct size by T-0970 was abolished by pretreatment with CHE and 5-HD. Neither CHE nor 5-HD alone had any effect on infarct size. The percentage of infarcted myocytes with DNA fragmentation by TUNEL in the T-0970 group was significantly reduced compared with the number in the control group (4.0+/-1.5 vs 10.7+/-1.9%, respectively; P<0.05). 5. T-0970, a free radical scavenger, improved reperfusion injury. This effect seemed to be mediated by activation of PKC, the opening of mitochondrial K(ATP) channels and inhibition of DNA fragmentation.

ATP-Binding Cassette Transporters↗
PubMed2001

Ischemic preconditioning of rat livers against cold storage-reperfusion injury: role of nonparenchymal cells and the phenomenon of heterologous preconditioning.

Brief periods of ischemia followed by reperfusion render tissues resistant against subsequent prolonged ischemia, a phenomenon called ischemic preconditioning. The effect of ischemic preconditioning on liver transplantation was investigated in relation to sinusoidal endothelial cell injury and Kupffer-cell activation, which are prominent features of storage and reperfusion injury leading to liver graft failure. Rat livers were preconditioned by 5 or 10 minutes of ischemia and 5 minutes of reperfusion and stored in University of Wisconsin (UW) solution for 30 hours. Livers were then reperfused for 15 minutes with physiological buffer containing trypan blue. Under these conditions, injury occurs predominantly to sinusoidal endothelial cells, reflected by trypan blue staining of nonparenchymal cells in histological sections. Ischemic preconditioning decreased nonparenchymal cell killing by more than 50%. When half the liver was preconditioned, sinusoidal endothelial cells were also protected in the contralateral half. Other stored livers were reperfused with nitroblue tetrazolium, which is converted to insoluble formazan by superoxide radicals. Ischemic preconditioning decreased the intensity of formazan deposition over Kupffer cells. Finally, stored livers were transplanted into nontreated rats. Ischemic preconditioning improved recipient long-term survival after 30 hours of cold ischemic storage in UW solution from 30% to 80% and decreased serum tumor necrosis factor-alpha levels in posthepatic blood 4 hours postoperatively from 98 to 54 pg/mL. In conclusion, ischemic preconditioning protects sinusoidal endothelial cells and suppresses Kupffer-cell activation after storage and reperfusion. As a result, graft survival improves after liver transplantation. Moreover, ischemia to half the liver confers protection to the other half. Such heterologous preconditioning provides a new means to protect liver tissue against ischemia-reperfusion injury without imposing ischemia on the target tissue.

Animals↗
PubMed2001

Maturation of mass-screened localized adrenal neuroblastoma.

BACKGROUND/PURPOSE: In infants, neuroblastoma has been known to spontaneously differentiate into a benign ganglioneuroma. Although several investigators have compared mass-screened with unscreened, disseminated with localized, and adrenal with retroperitoneal neuroblastoma, there are very few cross-comparisons of the above parameters. Herein, the authors report the maturation of mass-screened, localized adrenal neuroblastoma. METHODS: Fifty-one mass-screened adrenal neuroblastomas were divided into 2 groups. In infants less than 1 year of age (Group A), 45 neuroblastomas were resected, whereas 6 neuroblastomas were resected after observation in 1- to 4-year-old children (group B). Histopathology of the tumors in the 2 groups was compared. Data were analyzed by X(2) test, and P <.05 was considered significant. RESULTS: According to the International Neuroblastoma Pathological Classification, 41 of 45 tumors of group A were "differentiating neuroblastoma" and 4 of 6 tumors of group B were "maturing ganglioneuroma." Maturation toward ganglioneuroblastoma was observed in 16 neuroblastomas of group A (36%) and 6 neuroblastomas of group B (100%). In group A, 58% had low mitosis karyorrhexis index (MKI); all patients in group B had low MKI. CONCLUSIONS: If left untreated, maturation of mass-screened, localized adrenal neuroblastomas is a common phenomenon. These children do not need to undergo early operation.

Adrenal Gland Neoplasms↗
PubMed2001

Common cell-surface antigens functioning in self-recognition reactions by both somatic cells and gametes in the solitary ascidian Halocynthia roretzi.

The "contact reaction" is an extremely rapid allogeneic cytotoxic reaction (ACR) mediated by hemocytes in the solitary ascidian Halocynthia roretzi. It has been proposed that regulation of the alloreactivity of hemocytes may be involved in preference for fertilization or self-sterility in this species. To identify the receptors and target ligands involved both in self-recognition by somatic cells and self-discrimination by gametes, we produced monoclonal antibodies (mAbs) that inhibit the ACR mediated by hemocytes and tested their effects on fertilization. Six different mAbs that inhibit the ACR were prepared and categorized into three groups. Although all three mAbs seemed to have the same ability to inhibit the ACR, almost constant and statistically significant inhibition (CRB1.1) and infrequent but significant inhibition (CRB2.1, and CRB3.1) of the ACR were observed in the same pairs of animals. Pretreatment of the unfertilized eggs with CRB1.1, CRB2.1, and CRB3.1, resulted in the constant and statistically significant inhibition, infrequent but significant inhibition, and no inhibition, respectively, of fertilization. Antigens recognized by CRB1.1 (CRB1.1 antigens) were detected on the cell surface of all types of hemocytes and on the vitelline coat and follicle cells of unfertilized eggs. CRB2.1 and CRB3.1 antigens were detected on the surface of certain types of hemocytes and follicle cells, but not on the vitelline coat. CRB mAbs were directed against different epitopes in the N-linked glycan on glycoproteins. These common carbohydrate antigens on somatic cells and gametes may function in some recognition processes in ACR and fertilization in H. roretzi.

Animals↗