ABSTRACT
A simple and novel genotyping method was developed to detect alleles at the swine leukocyte antigen (SLA)-DRB1 and -DQB1 class II loci by using polymerase chain reaction (PCR)-fluorescently labeled sequence-specific oligonucleotide probes (SSOPs) and Luminex 100 xMAP detection. The PCR-SSOP-Luminex method exhibited accuracy of 95% for both SLA-DRB1 and -DQB1 in 6 homozygous and 16 heterozygous pig samples as confirmed by sequencing the PCR products of the same samples. In addition, 12 low-resolution SLA class II haplotypes consisting of 7 and 9 DRB1 and DQB1 alleles were identified, respectively, in one population of 283 Landrace pigs. This genotyping method facilitates the rapid and accurate identification of two- or four-digit alleles at the SLA-DRB1 and -DQB1 loci.
Subject(s)
Histocompatibility Antigens Class II/genetics , Polymerase Chain Reaction/methods , Swine/genetics , Animals , Gene Frequency , Genetic Loci , Genotype , Histocompatibility Antigens Class I , Histocompatibility Antigens Class II/immunology , Histocompatibility Testing/methods , Histocompatibility Testing/veterinary , Oligonucleotide Probes/genetics , Polymerase Chain Reaction/instrumentation , Substrate Specificity/genetics , Swine/immunologyABSTRACT
To date, there have been no reports showing the efficacy of nonsecosteroidal vitamin D receptor (VDR) agonists in a benign prostatic hyperplasia (BPH) animal model. To examine the efficacy of CH5036249, a novel nonsecosteroidal VDR agonist, we orally administered the compound at 0.03 microg/kg to a beagle model with spontaneous BPH. Prostate volume was checked by rectal ultrasonic probe periodically during 11 months of administration and the prostate tissues histologically examined. CH5036249 inhibited prostate growth in two out of three dogs compared with vehicle-treated dogs. In the prostate specimens, substantial atrophy of the epithelium was observed in all dogs administered CH5036249. At the dose given, serum calcium levels slightly increased in the CH5036249-treated dogs but stayed within a normal range. We next examined the cell growth inhibition of CH5036249 using human prostate stromal cells and found the cell growth inhibitory activity of CH5036249 to be comparable to that of 1alpha,25(OH)2D3. The bioavailability from oral administration in rats was 95.1% with a t1/2 of 17.6 h. Both micro-AMES and micronucleus tests were negative. Although the results are still preliminary, we consider the novel nonsecosteroidal VDR agonist CH5036249 to be a possible new drug candidate for the treatment of BPH in humans.
Subject(s)
Benzhydryl Compounds/pharmacology , Prostatic Hyperplasia/pathology , Pyridines/pharmacology , Receptors, Calcitriol/agonists , Animals , Benzhydryl Compounds/chemistry , Calcium/blood , Cell Proliferation , Disease Models, Animal , Dogs , Dose-Response Relationship, Drug , Humans , Male , Micronucleus Tests , Models, Biological , Prostate/drug effects , Prostate/metabolism , Pyridines/chemistry , Rats , Receptors, Calcitriol/metabolism , Stromal Cells/cytologyABSTRACT
We report high resolution Compton scattering measurements on an Al(97)Li(3) disordered alloy single crystal for momentum transfer along the [100], [110], and [111] symmetry directions. The results are interpreted via corresponding Korringa-Kohn-Rostoker coherent potential approximation first-principles computations. By comparing spectra for Al(97)Li(3) and Al, we show that the momentum density in the alloy differs significantly from the predictions of the conventional Fermi-liquid picture and that the ground state of Al is modified anomalously by the addition of Li.
ABSTRACT
It is demonstrated that long-term stability in the polarization of incident photons delivered from an insertion device makes it possible to measure magnetic Compton profiles with a momentum resolution of 0.15 atomic units or better, without employing a solid-state detector and the traditional method of reversing the external magnetic field or the handedness of the polarization of incident photons in an asynchronous cycle with a short period of tens to hundreds of seconds.
ABSTRACT
BACKGROUND: To date, there has not been an in-depth investigation to identify differences in the effects of bleeding prevention among different routes of administration of H2 receptor antagonists to treat gastric ulcers following endoscopic mucosal resection (EMR). AIM: To prospectively compare the frequency of bleeding following EMR between patients treated with intravenous (IV) famotidine and those with oral famotidine. METHODS: Fifty-three patients with neoplastic gastric lesions (33 carcinoma and 20 adenoma) treated by EMR were included. Subjects underwent EMR with circumferential mucosal incision assisted by submucosal injection of sodium hyaluronate (EMRSH), followed by IV or oral (PO) administration of famotidine at a dosage of 40 mg/day for 2 days. Patients with odd ID numbers were assigned to IV therapy (30 cases) while even numbers were given PO therapy (23 cases). Frequencies and endoscopic findings of bleeding during the first 2 days after EMR were examined. RESULTS: Frequency of bleeding within 2 days after EMR was 3 and 4% in IV and PO patients, respectively, showing no significant difference. No significant difference was seen in the endoscopic findings of bleeding and therapy, either, with respective IV and PO findings at 23 and 26%. CONCLUSIONS: No significant difference was observed in frequency of bleeding within 2 days after gastric EMR between IV and oral administrations of famotidine.
Subject(s)
Adenocarcinoma/drug therapy , Famotidine/administration & dosage , Gastrointestinal Hemorrhage/prevention & control , Histamine H2 Antagonists/administration & dosage , Postoperative Hemorrhage/prevention & control , Stomach Neoplasms/drug therapy , Adenocarcinoma/surgery , Adjuvants, Immunologic/administration & dosage , Administration, Oral , Aged , Endoscopy, Gastrointestinal/adverse effects , Female , Gastrointestinal Hemorrhage/etiology , Hemostasis, Endoscopic/adverse effects , Humans , Hyaluronic Acid/administration & dosage , Infusions, Intravenous , Intestinal Mucosa/surgery , Male , Middle Aged , Postoperative Hemorrhage/etiology , Prospective Studies , Recurrence , Stomach Neoplasms/surgeryABSTRACT
The extreme polymorphism in different loci of the human leukocyte antigen (HLA) system has been used as an invaluable tool for anthropological studies. Determination of HLA allele and haplotype frequencies in different ethnic groups is useful for population genetic analyses and the study of genetic relationships among them. In the present study, molecular analysis of HLA-A, -B, -C, -DQA1, -DQB1, and -DRB1 genes has been used to assign HLA allele and haplotype frequencies in 100 unrelated healthy individuals from the Baloch ethnic group of Iran. The results were compared with Baloch and other ethnic groups in the neighboring Pakistan. The results of this study showed that the most frequent HLA class I alleles were A*02011 (20.2%), B*4006 (11.1%), and C*04011 (28.6%). The most common HLA class II alleles were DQA1*0101/2 (42.5%), DQB1*0201 (32%), and DRB1*0301 (29%). Three-locus haplotype analysis revealed that A*11011-B*4006-C*15021 (5.8%) and DQA1*0501-DQB1*0201-DRB1*0301 (22.1%) were the most common HLA class I and II haplotypes, respectively, in this population. Neighbor-joining tree based on DA genetic distances and correspondence analysis according to HLA-A, -B, -DQB1, and -DRB1 allele frequencies showed that Baloch of Iran are genetically very close to Baloch and Brahui of Pakistan. This may reflect an admixture of Brahui and Baloch ethnic groups of Pakistan in the Balochistan province of Iran.
Subject(s)
Gene Frequency , HLA Antigens/genetics , Haplotypes , Sequence Analysis, DNA , Alleles , Genetic Markers , Genetics, Population , Humans , Iran , Pakistan , Phylogeny , Polymorphism, GeneticABSTRACT
We investigated the effect of insulin on the expression of the enhancer of split- and hairy-related protein-2 gene in 3T3-L1 adipocytes and L6 myotubes. The level of enhancer of split- and hairy-related protein-2 mRNA was increased by insulin in both cells. While both wortmannin and LY294002 blocked the increase in 3T3-L1 adipocytes, and only PD98059 was effective in L6 myotubes. Although the increase by insulin in these cells was inhibited by treatment with actinomycin D, this was enhanced by treatment with cycloheximide. Furthermore, cyclic AMP increased the level of enhancer of split- and hairy-related protein-2 mRNA in both cells in an additive manner. Thus, we conclude that insulin and cyclic AMP induce the expression of the enhancer of split- and hairy-related protein-2 gene in both 3T3-L1 adipocytes and L6 myotubes, and that the gene expression enhanced by insulin is regulated by the cell type-specific pathway. The former requires a phosphoinositide 3-kinase pathway and the latter a mitogen-activated protein kinase pathway.
Subject(s)
Adipocytes/metabolism , Enhancer Elements, Genetic/genetics , Gene Expression/drug effects , Insulin/pharmacology , Muscle Fibers, Skeletal/metabolism , Repressor Proteins/metabolism , 3T3 Cells , Adipocytes/drug effects , Animals , Basic Helix-Loop-Helix Transcription Factors , Cyclic AMP/pharmacology , Drug Synergism , Insulin/metabolism , Mice , Muscle Fibers, Skeletal/drug effects , RNA, Messenger/metabolism , Repressor Proteins/genetics , Signal TransductionABSTRACT
In order to determine whether matching/mismatching for microsatellite polymorphism provides useful information on acute graft-vs-host disease (GVHD), survival, and leukemia relapse in hematopoietic stem cell (HSC) transplantation, we genotyped for polymorphisms at 13 microsatellite loci within the major histocompatibility complex (MHC) of 100 unrelated HSC transplant donor-recipient pairs who were matched at five classical human leukocyte antigen (HLA) loci. A high percentage of allele matching was obtained for five microsatellite loci, DQCARII (96%), MICA (93%), MIB (89%), C1-3-1 (93%), and D6S510 (97%), that are localized within 100 kb of the HLA-DR, HLA-DQ, HLA-B, HLA-C, or HLA-A locus. In contrast, the other eight microsatellites are located farther away from the HLA classical loci and have much lower percentages of allele matching [e.g. tumor necrosis factor a (TNFa) (73%), TNFd (74%), D6S273 (64%), C3-2-11 (46%), C5-3-1 (50%), C5-4-5 (63%), C5-2-7 (68%), and D6S265 (81%)]. Therefore, there were at least eight microsatellite markers with relatively high percentages of mismatches in the donor/recipient pairs with acute or chronic GVHD, poor graft survival, and leukemia relapse. However, there were no statistically significant associations between mismatched donor-recipient pairs at the 13 microsatellite loci and acute or chronic GVHD, graft survival, and leukemia relapse. Nevertheless, allele matching at the microsatellite TNFd locus near the TNFa gene was found by the Fisher's exact double-sided test to be significantly associated with decreased survival in the grade III/IV acute GVHD group. Overall, these results suggest that the matching of microsatellite polymorphisms within the HLA region, especially the ones farthest from the classical HLA loci, was not useful indicator for the outcome of HSC transplantation from unrelated donors. In this regard, the future determination of the genome-wide microsatellite genotypes in HLA-matched donor-recipient pairs, outside the MHC, may be a better possibility for identifying minor histocompatibility genes in linkage disequilibria with microsatellites as potential predictive markers for the occurrence of acute GVHD and survival rate in HSC transplantation.
Subject(s)
Graft vs Host Disease/genetics , HLA-DQ Antigens/genetics , HLA-DR Antigens/genetics , Hematopoietic Stem Cell Transplantation , Histocompatibility Antigens Class I/genetics , Leukemia/therapy , Microsatellite Repeats/genetics , Adolescent , Adult , Child , Child, Preschool , Female , Genetic Markers , Graft vs Host Disease/immunology , Graft vs Host Disease/mortality , Histocompatibility Testing , Humans , Infant , Leukemia/genetics , Leukemia/immunology , Leukemia/pathology , Male , Middle Aged , Prognosis , RecurrenceABSTRACT
En-bloc resection is desirable for accurate histopathological assessment of tissue specimens obtained using endoscopic mucosal resection (EMR). A new EMR method using sodium hyaluronate and a small-caliber-tip transparent hood has been developed. This is a peeling-off method using a needle-knife for mucosal and submucosal incisions. Long-lasting submucosal thickening resulting from an injection of sodium hyaluronate, and good visualization of the submucosal tissue with the aid of a small-caliber-tip transparent hood, make the cutting procedures easy and safe. A large superficial gastric cancer and a large villous tumor of the sigmoid colon were endoscopically resected using this method. En-bloc endoscopic resection was successful in both patients. The gastric lesion was an well-differentiated intramucosal adenocarcinoma, completely resected in a specimen measuring 97 x 50 mm. The colonic lesion was an intramucosal well-differentiated adenocarcinoma in adenoma, completely resected in a specimen measuring 70 x 55 mm in diameter. No significant complications were noted in either patient. The new method of EMR using sodium hyaluronate and the small-caliber-tip transparent hood is a promising method for endoscopic en-bloc resection of large superficial neoplastic lesions, both in the stomach and the colon.
Subject(s)
Adenocarcinoma/surgery , Adjuvants, Immunologic/therapeutic use , Endoscopy, Gastrointestinal/methods , Gastric Mucosa/surgery , Hyaluronic Acid/therapeutic use , Sigmoid Neoplasms/surgery , Stomach Neoplasms/surgery , Adenocarcinoma/pathology , Aged , Female , Gastric Mucosa/pathology , Humans , Middle Aged , Sigmoid Neoplasms/pathology , Stomach Neoplasms/pathologyABSTRACT
BACKGROUND: Change in apoptosis in gastric glands after eradication of Helicobacter pylori has never been reported. AIMS: The purpose of this paper is to investigate the change in apoptosis in gastric glands after eradication of Heliobacter pylori. PATIENTS AND METHODS: We studied 23 Heliobacter pylori-positive patients with duodenal and gastric ulcers, who were monitored for 6-12 months after eradication, and eight controls. Biopsies were taken from the antrum and body. Apoptosis was evaluated immunohistochemically using anti-single stranded DNA antibody. Apoptotic index was calculated by counting immunostained cells in surface epithelial and glandular cells. RESULTS: In the surface epithelium, Apoptotic indexes were significantly higher in patients than in controls. In the upper portion of fundic glands, apoptotic indexes were significantly higher in patients with gastric ulcers (14.2% (9.3, 17.8)) (median (1st quartile, 3rd quartile)) than in controls (8.0% (2.0, 9.0), p < 0.01) and decreased significantly after eradication (3.4% (2.0, 5.3)), p < 0.01). In pyloric glands, apoptotic indexes were no different between patients and controls. In the lower portion of fundic glands, apoptotic indexes were very low, both in patients and in controls. CONCLUSIONS: Our results showed that apoptosis, not only of surface epithelial cells but also of glandular cells in the upper portion of fundic glands, increased in Heliobacter pylori-positive patients with gastric ulcers and decreased to normal levels after eradication of Heliobacter pylori.
Subject(s)
Apoptosis , Gastric Mucosa/pathology , Helicobacter Infections/drug therapy , Helicobacter pylori , Stomach Ulcer/drug therapy , Adult , Aged , DNA, Single-Stranded/analysis , Epithelium/pathology , Female , Gastritis/microbiology , Gastritis/pathology , Helicobacter Infections/pathology , Humans , Immunohistochemistry , Male , Middle Aged , Stomach Ulcer/microbiology , Stomach Ulcer/pathologySubject(s)
Brain Death/physiopathology , Epinephrine/pharmacology , Hemodynamics/physiology , Receptors, Adrenergic, beta/metabolism , Catecholamines/blood , Catecholamines/metabolism , Humans , Japan , Kinetics , Receptors, Adrenergic, beta/drug effects , Transplantation/legislation & jurisprudenceABSTRACT
The HLA-DO molecule is a non-classical class II heterodimer composed of alpha and beta chains. We have previously recognized that all eight of the allelic variations of the HLA-DOA gene represent non-synonymous amino acid substitution. In the present study, to analyze genetic polymorphism and allelic variation of the HLA-DOB gene which may affect the efficiency of class II restricted antigen presentation thereby being involved in the susceptibility of HLA associated diseases, we conducted direct DNA sequencing of HLA-DOB in 36 HLA class II homozygous typing cells and identified six new allelic variations (DOB*0101101, *0101102, *01012, *01022, *0104101 and *0104102) including five single nucleotide polymorphisms with only one amino acid substitution. Furthermore, strong linkage disequilibrium was detected between DOB*01022 and DRB1*1502 only, with no linkage disequilibrium between the DOA and the DOB genes. The HLA-DOB gene has been identified in other mammals, and their nucleotide sequences are well conserved. These facts suggest that limited polymorphism in the DOB gene is profitable to execute their unique function as a co chaperone and so strong selective pressure is operating to prevent generic variation against the DOB molecule interacting with the DM molecule and thus maintaining the specified immunological function of regulating antigen presentation.
Subject(s)
Amino Acid Substitution , HLA-D Antigens/genetics , Polymorphism, Single Nucleotide , Alleles , Amino Acid Sequence , Base Sequence , Humans , Molecular Sequence DataABSTRACT
The orbitally ordered phase of DyB2C2 has been studied by nonresonant x-ray diffraction with high-brilliance synchrotron radiation. From the condition of diffraction, the symmetry property of the charge distribution around dysprosium has been concluded at the quadrupolar level. The quantitative inspection, furthermore, indicates that the observed signals cannot be interpreted as arising only from the 4f electrons of dysprosium responsible for the ordering; instead, the experiment can be described rather well by considering a distortion of the metaloid network concomitant with the ordering.
ABSTRACT
OBJECTIVE: Open heart surgery without transfusion has been performed even in children. However, the critical limit of the hemoglobin level has not yet been ascertained. Here, we have assessed experimentally the effect of the hemoglobin level on brain metabolism under hypothermic cardiopulmonary bypass. METHODS: Brain tissue pH was measured in 14 rabbits that were put on bypass with a different degree of hemodilution. Cardiopulmonary bypass was started at 37 degrees C and cooled down to 25 degrees C. After maintaining the bypass at 25 degrees C for 60 minutes, the animal was rewarmed to 37 degrees C for 30 minutes and then kept on-bypass for another 30 minutes. The perfusion flow was maintained as 10 ml/kg/min. RESULTS: The lowest hemoglobin level in each rabbit was from 2.5 through 8.5 g/dl. During hypothermic bypass, brain tissue pH increased from 7.21 +/- 0.16 (mean +/- SD, at the normothermic baseline) to 7.55 +/- 0.27 except 2 cases (6.91 +/- 0.16) whose hemoglobin level was lower than 3.0 g/dl. The brain tissue pH after 60 minutes on hypothermic bypass had a good correlation with the hemoglobin level (r = 0.831). After rewarming for 60 minutes, the brain tissue pH was decreased to 7.18 +/- 0.31. In 4 rabbits with less than 4.0 g/dl of hemoglobin, the brain tissue pH (6.67 +/- 0.24) was lower than the baseline level. In the other 10 rabbits, the brain tissue pH (7.22 +/- 0.16) was almost the same as the baseline level. The correlation coefficient between the brain tissue pH and the hemoglobin level after rewarming for 60 minutes was 0.778. CONCLUSIONS: These results indicated that severe hemodilution in cardiopulmonary bypass promoted acidosis in brain even during hypothermia.
Subject(s)
Cardiopulmonary Bypass , Hemodilution , Hypothermia, Induced , Perfusion , Animals , Brain/metabolism , Cerebrovascular Circulation , Hydrogen-Ion Concentration , RabbitsABSTRACT
MICA or PERB11.1 is a polymorphic major histocompatibility complex (MHC) class I-related gene located 46 kb centromeric of the HLA-B gene in the HLA class I region. It is expressed mainly in gut epithelial cells, keratinocytes, endothelial cells, fibroblasts and monocytes, and is upregulated by heat stress. MICA has been found to interact with gamma delta T cells, alpha beta CD8(+) and natural killer (NK) cells bearing the NKG2D/DAP10 receptor. The MICA gene displays a high degree of polymorphism with at least 54 alleles. In the present study, polymorphic exons 2, 3 and 4 of the MICA gene were analyzed using sequencing based typing (SBT) in 255 unrelated healthy northeastern Thais. Thirteen previously reported MICA alleles were detected. MICA*008, *010, *002 and *019 were highly predominant with the allele frequencies of 21.4%, 18.2%, 17.6% and 15.3%, respectively. Five of these 13 MICA alleles show significantly different frequencies from those of the Japanese and Caucasian populations. Interestingly, MICA052, which is a very rare allele in other populations, was prevalent with the allele frequency of 8.2%, mainly on the HLA haplotype carrying HLA-B*13 in this population. Strong linkage disequilibria were observed between MICA and HLA-B, as similarly observed in other populations, namely MICA*010-B*4601, MICA052-B*13, MICA*002-B*5801, and MICA*019-B*15 (1502, 1508, 1511, 1515, 1528, 1530). A large variety of three-locus (MICA - HLA-B - HLA-Cw) and six-locus (HLA-DQB1 - HLA-DRB1 - MICA - HLA-B - HLA-Cw - HLA-A) haplotypes were recognized in the northeastern Thai population. This is the first report on MICA allelic distribution in Southeast Asian populations. These data will provide the important basis for future analyses on the potential role of the MICA gene in disease susceptibility and transplantation matching in Southeast Asian populations.
Subject(s)
Genetic Variation , HLA Antigens/genetics , Proteins/genetics , Asian People/genetics , Gene Frequency , HLA-A Antigens/genetics , HLA-B Antigens/genetics , HLA-DQ Antigens/genetics , HLA-DQ beta-Chains , HLA-DR Antigens/genetics , HLA-DRB1 Chains , Haplotypes , Histocompatibility Antigens Class I , Humans , Japan , Linkage Disequilibrium , Molecular Sequence Data , Polymorphism, Genetic , Thailand , White People/geneticsABSTRACT
We studied vascular endothelial growth factor (VEGF) mRNA synthesis by peripheral blood mononuclear cells (PBMCs) in 30 patients with acute myocardial infarction (AMI) and 20 healthy individuals. PBMCs were isolated from all patients on days 3 and 14 after the onset of aMI, and from all of control individuals. To prepare samples containing identical amounts of GAPDH cDNA, competitive PCR was performed by co-amplifying serial dilutions of GAPDH mutant templates. Next, to measure VEGF cDNA quantitatively in the samples containing identical amounts of GAPDH, we also used competitive PCR by co-amplifying mutant templates of VEGF. The serum VEGF concentrations on day 14 in patients with aMI were measured by an ELISA method. Higher levels of VEGF mRNA in PBMCs were present on day 14 than either on day 3 or in the control group. Serum VEGF concentrations correlated with the VEGF mRNA levels of PBMCs on day 14. Peak serum CK levels correlated well with VEGF mRNA levels of PBMCs on day 14. The present findings suggest that PBMCs may be one of the candidates responsible for elevated circulatory VEGF protein following aMI. In addition, VEGF mRNA may be overexpressed in PBMCs in response to cardiac muscle damage.
Subject(s)
Endothelial Growth Factors/biosynthesis , Endothelial Growth Factors/genetics , Leukocytes, Mononuclear/metabolism , Lymphokines/biosynthesis , Lymphokines/genetics , Myocardial Infarction/genetics , Myocardial Infarction/metabolism , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Aged , Creatine Kinase/blood , Electrocardiography , Endothelial Growth Factors/blood , Enzyme-Linked Immunosorbent Assay , Female , Humans , Lymphokines/blood , Male , Middle Aged , Myocardial Infarction/therapy , Polymerase Chain Reaction , RNA, Messenger/blood , Regression Analysis , Time Factors , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth FactorsABSTRACT
We report a patient with a severe inclusion body myositis (IBM). His illness was unusual in terms of a rapid progression, high creatine kinase levels, and complication with interstitial pneumonia. He responded well to immunosuppressive agents such as corticosteroids, cyclosporin A, cyclophosphamide, and immunoglobulin. The present patient indicates the wide range of the disease, and that immunosuppressive agents may be useful for treatment of IBM.
Subject(s)
Lung Diseases, Interstitial/complications , Lung Diseases, Interstitial/diagnosis , Myositis, Inclusion Body/complications , Myositis, Inclusion Body/diagnosis , Aged , Cyclosporine/therapeutic use , Humans , Immunosuppressive Agents/therapeutic use , Lung Diseases, Interstitial/drug therapy , Male , Methylprednisolone/therapeutic use , Myositis, Inclusion Body/drug therapy , Severity of Illness Index , Tomography, X-Ray ComputedABSTRACT
PURPOSE: To clarify differences in the dynamics of convergence eye movements in response to symmetrical stimuli between the dominant eye and the nondominant eye under natural viewing conditions. METHODS: This study was conducted in 11 normal volunteers (age range, 22-30 years). The subject was seated on a chair, and the head was fixed using a bite-block. The dominant eye was determined with the "hole-in-the-card" test. Horizontal positions of the eyes were recorded using an infrared reflection device. Recordings of right eye movements were subtracted from left eye movements to obtain the vergence response. The fixation target was moved toward the center of both eyes from 50 to 20 cm in front of the face at a constant velocity in five steps (20, 30, 40, 50, and 60 cm/s). The target was moved by a pulse motor controlled by a microcomputer. The dynamic properties of each eye movement and the vergence components were analyzed. RESULTS: At velocities < or =40 cm/s, convergence responses consisted of two components: the fusion-initiating component and the fusion-sustaining component. The fusion-initiating component drove the initial faster dynamic portion of the response, and the fusion-sustaining component maintained the latter slower dynamic portion of the response. The mean peak velocity of the fusion-initiating component was significantly greater in the dominant eye than in the nondominant eye. The mean peak latency of the catch-up component was significantly shorter in the dominant eye than in the nondominant eye. CONCLUSIONS: The present study indicated that the trajectory of convergence eye movement under natural viewing conditions consists of two components, the fusion-initiating component and the fusion-sustaining component, and that the convergence response to symmetric stimuli was asymmetric between the dominant eye and the nondominant eye during the fusion-initiating phase. The neural control system of convergence eye movements preferentially drives the dominant eye during the fusion-initiating phase of the response.