PubMed Health⌕ Search

Biomedical subjects

N Kuji

Publications and source records attributed to N Kuji.

At least 19 recordsLinked to original sources
PubMed2003

Expression of the exocytotic protein syntaxin in mouse oocytes.

Syntaxin is an integral membrane protein that is involved in membrane fusion. The exocytosis of the contents of cortical granules, secretory vesicles located in the cortex of an egg, modify the extracellular environment to block additional spermatozoa from penetrating the newly fertilized egg. The aim of this study was to characterize syntaxin expression in mouse oocytes, and to determine the specific isoform that is expressed. Syntaxin was demonstrated in the mouse ovary and in mouse oocytes by both western blot and reverse transcription-polymerase chain reaction analyses. Syntaxin 4 was specifically expressed in metaphase II oocytes. Syntaxin was also immunolocalized within metaphase II oocytes and one-cell embryos with pronuclei using laser scanning confocal microscopy. In metaphase II oocytes, syntaxin was located on the plasma membrane and in the cortex, where cortical granules are present, but was not seen at sites free of cortical granules. In one-cell embryos, no cytoplasmic region was free of syntaxin immunoreactivity. Immunoelectron microscopy detected syntaxin on both the plasma membrane and the vesicle membranes in mouse metaphase II oocytes. In conclusion the results indicate that syntaxin 4 co-localizes with cortical granules and participates in membrane fusion and exocytosis during the cortical reaction.

Animals↗
PubMed2002

Clinical implications of cardiac (123)I-meta-iodobenzylguanidine scintigraphy and cardiac natriuretic peptides in patients with heart disease.

The purpose of this study was to evaluate whether or not cardiac sympathetic nerve activity, using (123)I-meta-iodobenzylguanidine ((123)I-MIBG) imaging, and cardiac natriuretic peptides (atrial and brain, ANP and BNP) were independent predictors of cardiac events, and, if so, which was the stronger predictor. Planar (123)I-MIBG images were obtained from 62 patients with heart disease. Plasma ANP and BNP levels, left ventricular ejection fraction (LVEF) by echocardiography, serum total cholesterol and triglyceride were measured. (123)I-MIBG was assessed as the heart-to-mediastinum (H/M) ratio of the delayed image and the washout rate (WoR) from the early to the delayed image. Patients were followed up for an average of 16.2 months, and 12 of 62 patients had cardiac events. Patients with events had significantly lower LVEF and H/M ratio compared with those without events. They had significantly higher WoR, ANP and BNP. By multivariate Cox proportional hazard analysis, (123)I-MIBG (H/M or WoR), ANP and BNP were independent predictors for cardiac events. Event-free survival using a Kaplan-Meier model, with a threshold value of 2.0 for H/M and 45% for WoR, showed that patients with H/M<2.0 and/or WoR>45% had a significantly poorer prognosis. These results suggest that (123)I-MIBG imaging and cardiac natriuretic peptides are useful tools for the evaluation of patients with heart disease, and that cardiac sympathetic nerve activity is a stronger predictor of cardiac events.

3-Iodobenzylguanidine↗
PubMed2000

An evaluation of semen processing methods for eliminating HIV-1.

OBJECTIVE: Whether artificial insemination can provide adequate protection for discordant couples where the man is HIV-1 positive and the woman is HIV-1 negative is uncertain because of the paucity of HIV-1 elimination data assessing current sperm-washing techniques. We evaluated how effectively these techniques eliminate HIV-1 RNA and proviral DNA from semen. METHODS: Spermatozoa were separated from semen samples from HIV-1-positive patients with haemophilia by discontinuous Percoll gradient centrifugation and the 'swim-up' method. The HIV-1 RNA and proviral DNA were measured by a highly sensitive PCR. In another test 5 x 10(6) copies of HIV-1 RNA (LAI strain) were added to semen from healthy donors and then assessed after single and combined procedures. RESULTS: Swim-up processing after Percoll gradient centrifugation reduced HIV-1 RNA and HIV-1 proviral DNA in semen to undetectable levels in the original specimen. Although discontinuous and continuous Percoll gradient centrifugation respectively reduced HIV-1 RNA added to seminal plasma specimens from healthy donors to less than < 1 copy from 10(5) and about 1 copy per 10(3) pre-separation copies, the discontinuous method left detectable HIV-1 RNA and proviral DNA in one out of 12 samples from patients with HIV-1 infection (8%). HIV-1 RNA and proviral DNA were decreased to undetectable levels after adding the swim-up procedure. CONCLUSIONS: Swim-up separation following Percoll gradient centrifugation should offer adequate protection for HIV-1-discordant couples.

Adult↗
PubMed2000

Accurate multiplex polymerase chain reaction assay for gender determination from a single cell.

For gender determination of preimplantation embryos or circulating fetal cells in maternal blood, we developed a multiplex polymerase chain reaction assay from a single cell. This assay which co-amplifies X (DXZ1)- and Y (DYZ1)-specific repeat sequences, yields a 308-bp band in females and two bands of 154 and 308 bp in males. In a randomized, blinded assay of 100 isolated single amniocytes, 99 (99%) were amplified successfully. All 50 of the XY cells were correctly diagnosed as male (100%), whereas 49 of the 50 XX cells were diagnosed as female (98%). This accurate and efficient assay may be applicable in these clinical settings.

Amniotic Fluid↗
PubMed2000

Incidence of atrial flutter and atrial fibrillation in patients with implanted physiological pacemakers.

Atrial flutter (AF) is a troublesome arrhythmia for patients with an implanted pacemaker. Although it has recently become possible to eliminate AF by radiofrequency catheter ablation (RF-CA), the incidence of AF before and after pacemaker implantation has not been clarified. The present study was conducted with 123 consecutive patients (69.3+/-11.6 (SD) years old) implanted with pacemakers, excluding patients who had chronic atrial fibrillation (AFib) when the pacemaker was implanted; 69 patients with atrioventricular (AV) block and 54 patients with sick sinus syndrome (including 29 patients with bradycardia-tachycardia syndrome). All patients were implanted with physiological pacemakers. The follow-up period was 4.7+/-1.9 years. In 11 of the 123 patients (8.9%), AF was observed before pacemaker implantation and the incidence was significantly higher in patients with sick sinus syndrome than in those with AV block (16.7 vs 2.9%, p<0.01). Nine of the 29 patients with bradycardia-tachycardia syndrome (31%) had AF. After physiological pacemaker implantation, AF recurred in 9 of the 11 patients, and AF was newly observed in 1 patient. Thus, 10 of the 123 patients (8.1%) had AF after physiological pacemaker implantation. Recurrence of AF was not suppressed by physiological pacing. Thirty of the 123 patients had AFib before implantation of a pacemaker and its occurrence was reduced by physiological pacing (from 24.4% to 12.2%, p<0.05). The incidence of AFib in patients with AF was significantly higher than in those without AF (90.0 vs 5.3%, p<0.001). In conclusion, the recurrence of AF is not prevented by physiological pacing and is closely related to the occurrence of AFib. RF-CA should be considered in patients who have AF before pacemaker implantation.

Aged↗
PubMed1999

Value of ST-segment elevation pattern in predicting infarct size and left ventricular function at discharge in patients with reperfused acute anterior myocardial infarction.

BACKGROUND: The implication of the shape of ST elevation in the acute phase of myocardial infarction (MI) remains unclear. METHODS AND RESULTS: We examined the relation between the shape of ST elevation and infarct size in 77 patients who had a first acute anterior MI with successful reperfusion within 6 hours from symptom onset. A 12-lead electrocardiogram was recorded immediately before reperfusion confirmed by coronary angiography. The shape of ST elevation in lead V3 was classified into 3 types: concave type (n = 24), straight type (n = 41), and convex type (n = 12). For concave type, straight type, and convex type, a median value of peak creatine kinase was 2287, 4371, and 5322 mU/mL, and left ventricular ejection fraction measured by left ventriculography at discharge (14 days after MI) was 58%, 48%, and 41% (P <.05; concave type versus the other 2 types), respectively. A multivariate logistic regression model demonstrated that the concave type of ST elevation was a strong predicting factor for preserved left ventricular function (left ventricular ejection fraction >/=50% at discharge; odds ratio 6.2, 95% confidence interval 1.6 to 20.8, P =.019). CONCLUSIONS: In patients with reperfused acute anterior MI, left ventricular function was excellent in patients with concave type, intermediate in those with straight type, and relatively poor in those with convex type ST elevation at discharge. This simple classification is useful for predicting left ventricular function at discharge.

Adult↗
PubMed1999

An accurate and rapid gender determination assay in single cells by the capillary polymerase chain reaction method.

PURPOSE: In preimplantation genetic diagnosis (PGD), a rapid and accurate assay has been required. We have therefore developed a capillary polymerase chain reaction (PCR) method using rapid thermal cycling programs to determine the gender of single amniocytes. METHODS: Single amniocytes from each amniotic fluid sample were isolated by micromanipulation and their gender was determined by a multiplex PCR assay in a capillary tube, using primers that amplify a 308-bp DXZ1 and a 154-bp DYZ1 repeat sequence on the X and Y chromosomes, respectively. RESULTS: All four thermal cycling programs, which took 180, 150, 120, and 90 min, were 100% accurate in diagnosing the gender of single amniocytes. No DNA contamination was observed in any samples. CONCLUSIONS: The multiplex PCR assay was rapid and accurate in diagnosing gender in single cells and may be clinically applicable in PGD.

Amnion↗
PubMed1999

Assessment of the dominant abnormal form is useful for predicting the outcome of intracytoplasmic sperm injection in the case of severe teratozoospermia.

PURPOSE: Our purpose was to investigate the relation between the dominant sperm anomaly and sperm morphology and the outcome of intracytoplasmic sperm injection (ICSI). METHODS: Two hundred ninety-five patients who underwent a total of 181 cycles of in vitro fertilization (n = 168) and/or 217 cycles of ICSI (n = 177) between July 1995 and May 1997 at Keio University Hospital were investigated. RESULTS: The rates of fertilization and pregnancy were 63.3 and 27.8%, respectively, in ICSI cycles with < or = 4% normal forms. When the percentage of strictly normal morphology was < or = 4, the fertilization rate was lower in the case of severely tapered head (13.0%; n = 4) than in the cases of other deformities in ICSI. The acrosomal defect made no difference in the fertilization rate with ICSI. CONCLUSIONS: The predominant abnormal form affects the ICSI outcome in the case of < or = 4% normal forms.

Adult↗
PubMed1999

Prediction of optimal atrioventricular delay in patients with implanted DDD pacemakers.

In patients with an implanted DDD pacemaker (PM), the atrial contribution may be interrupted by too short an atrioventricular (AV) delay, and filling time may be shortened by too long an AV delay. The AV delay at which the end of the A wave on transmitral flow coincides with complete closure of the mitral valve may be optimal. The subjects were 15 patients [70.3+/-12.3 (SD) years old] with an implanted DDD PM. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. Transmitral flow was recorded by pulsed Doppler echocardiography. AV delay was prolonged stepwise by 25 msc. When the AV delay was set at 155+/-26 ms, the end of the A wave coincided with complete closure of the mitral valve. When the AV delay was prolonged 25, 50, 75, and 100 ms from this AV delay, the interval between the end of the A wave and complete closure of mitral the valve was prolonged 16+/-5, 39+/-6, 65+/-4 and 88+/-5 ms, respectively (r = 0.97, P<0.0001) and diastolic mitral regurgitation was observed during this period. Thus, the optimal AV delay may be predicted as follows: the slightly prolonged AV delay minus the interval between the end of the A wave and complete closure of the mitral valve. When the AV delay was set at 215 ms, there was a significant positive correlation between the predicted optimal AV delay (166+/-23 ms) and the optimal AV delay (CO: 161+/-26 msec, r = 0.93, P<0.0001, PCWP: 161+/-28 msec, r = 0.95, P<0.0001). In conclusion, optimal AV delay can be predicted by this simple formula: slightly prolonged AV delay minus the interval between end of A wave and complete closure of mitral valve at the AV delay setting.

Aged↗
PubMed1999

Successful pregnancy in a woman with a human seminal plasma allergy. A case report.

BACKGROUND: Human seminal plasma allergy is an anaphylaxis caused by immediate hypersensitivity to human seminal plasma. The utilization of a condom is usually recommended as the primary means of preventing an allergic reaction. Infertility resulting from condom use, however, is an undesirable complication in many cases. Here we report on a successfully established pregnancy in a woman with seminal plasma allergy. CASE: A 29-year-old, married nulligravida with a human seminal plasma allergy consulted us to conceive. She showed a positive reaction to a skin-prick test with whole semen. In order to remove the seminal plasma, the sperm were washed three times using a continuous-step density gradient centrifugation method. Artificial insemination with the washed sperm was performed without anaphylactic symptoms. After six inseminations, pregnancy was achieved, and a healthy infant was delivered. CONCLUSION: Artificial insemination with sperm devoid of seminal plasma was very useful for establishing pregnancy in a woman with a human seminal plasma allergy.

Adult↗
PubMed1998

Role of beta 1 integrins in human endometrium and decidua during implantation.

The present study was undertaken to investigate the expression and function of beta 1 integrins in human endometrium and decidua. Fluorescence-activated flow cytometry demonstrated the greater expression of the beta 1, alpha 1, alpha 2, and alpha 5 subunits of the beta 1 integrin family in cultured stromal cells from the midsecretory phase than in those of the early proliferative phase. The addition of estradiol (E2) and progesterone (P) to cultured stromal cells in the early proliferative phase increased the expression of beta 1 integrins in vitro. The immunohistochemical distribution of beta 1 integrins demonstrated predominantly glandular epithelial staining in the proliferative phase, and stromal and glandular staining in the midsecretory phase. Flow cytometry also demonstrated the expression of beta 1, alpha 1, alpha 2, alpha 3, alpha 5, and alpha 6 subunits of beta 1 integrin family in cultured decidual cells. Immunohistochemistry confirmed the beta 1 integrin cell surface phenotypes in cultured decidual cells observed by flow cytometry. In the subsequent experiment, the effects of antibodies against specific beta 1 integrin heterodimers on mouse embryo attachment and spreading were tested to identify the role of beta 1 integrins in early implantation. We developed assays for the attachment of mouse embryos and for trophoblastic spreading on cultured human decidual cells. The addition of antibodies directed against beta 1 and alpha integrin subunits to cultured decidual cells did not affect the rates of hatching or attachment of the blastocysts, whereas the outgrowth of embryos on the decidual cells was inhibited by their antibodies in a dose-dependent manner. Thus, beta 1 integrin in human endometrium and decidua may be important in mediating the organization of extracelllar matrix proteins derived from embryos during the early stage of implantation.

Adult↗
PubMed1998

[Optimal reperfusion therapy in acute myocardial infarction: time to reperfusion and recanalization rate].

Rapid and complete reperfusion is important for the reduction of infarct size and mortality in acute myocardial infarction. The optimum reperfusion therapy with regard to the recanalization rate and the time elapsing between onset and complete reperfusion was evaluated. One hundred fifty-four patients with total occlusion of the infarct-related artery within 6 hours of the onset were classified into four therapy groups: PTCA group (n = 58) undergoing primary percutaneous transluminal coronary angioplasty (PTCA), t-PA-IC group (n = 44) receiving tissue plasminogen activator (t-PA) intracoronary infusion, t-PA-IV group (n = 14) receiving intravenous t-PA infusion, and mt-PA-IV group (n = 38) receiving intravenous mutant t-PA infusion. Although the recanalization rate was high in the PTCA group, there were no differences between the four groups as a supplement to immediate or rescue PTCA. The time elapsing between initiation of thrombolysis and complete reperfusion was shorter in the mt-PA-IV group than in the t-PA-IV group. Assuming the time from hospital arrival to initiation of intravenous thrombolysis was 20 min, the recanalization rate at 60 min after arrival in hospital was higher in the mt-PA-IV group than the PTCA and t-PA-IC groups. Although additional coronary angiography and PTCA may be required to improve the low recanalization rate compared with primary PTCA, intravenous infusion of mutant t-PA was the most promising therapy to achieve early reperfusion.

Aged↗
PubMed1998

Effect of danazol on the pregnancy rate in patients with unsuccessful in vitro fertilization-embryo transfer.

OBJECTIVE: To determine the effect of danazol on in vitro fertilization-embryo transfer (IVF-ET) patients who failed to conceive in previous attempts despite having embryos with optimal morphology, whether endometriosis is present or not. STUDY DESIGN: In this prospective, randomized, controlled study, of 81 patients who experienced unexplained failures of IVF-ET despite having good-morphology embryos, 40 received danazol (400 mg/d orally for 12 weeks) following the unsuccessful IVF-ET cycle. The next IVF-ET was performed within three months of the first spontaneous ovulation after danazol administration. The remaining 41 patients constituted the control group, and in them the next IVF-ET was performed within six months after the previous failed cycle. RESULTS: Conception occurred in 16 of 40 (40%) danazol-treated patients at the subsequent cycle and showed a significant increase when compared with 8 of 41 (19.5%) control subjects (P < .05), though the number of embryos with optimal morphology decreased after danazol treatment. CONCLUSION: Danazol may be used for patients who have had repeated failures of IVF-ET despite having morphologically optimal embryos and may be useful for increasing receptivity of the endometrium in these patients.

Autoantibodies↗
PubMed1998

[A patient with disopyramide intoxication rescued by percutaneous cardiopulmonary support].

A 28-year-old man was admitted to our hospital in a hypotensive state 2 hours after taking 8,400 mg disopyramide. Infusion of catecholamine and gastric lavage restored normal blood pressure. However, 8 hours after taking the disopyramide he became hypotensive again and electrocardiographic findings revealed bizarre ventricular complexes resulting in ventricular flutter. Although standard cardiopulmonary resuscitation was not effective, his circulatory status was maintained by percutaneous cardiopulmonary support (PCPS). After 36 hours electrocardiography showed sinus rhythm, and his cardiac function became normal. Patients with severe cardiac dysfunction or cardiac arrest caused by disopyramide intoxication can be supported by PCPS until cardiac function is restored.

Adult↗
PubMed1997

Relation of absence of ST reelevation immediately after reperfusion and success of reperfusion with myocardial salvage.

To examine whether resolution in ST elevation without ST reelevation immediately after reperfusion indicates successful reperfusion with myocardial salvage, we studied 40 patients who had an extensive acute myocardial infarction with early reperfusion: 24 patients had ST reelevation and 16 patients had no ST reelevation. Results indicate that (1) in the group with ST reelevation, rapid progression of myocardial damage occurs by reperfusion itself (i.e., reperfusion injury) and (2) in the group without ST reelevation, myocardial damage had already been extensive and irreversible at the time of reperfusion; thus, the absence of ST reelevation is not always a sign of reperfusion with myocardial salvage.

Adult↗
PubMed1997

Integrins and reproductive physiology: expression and modulation in fertilization, embryogenesis, and implantation.

OBJECTIVE: To review the available information regarding the role of integrins in reproductive physiology and to discuss their potential clinical implications. DESIGN: Studies that specifically relate to the expression and modulation of integrins in fertilization, embryogenesis, and implantation were identified through the literature and Medline searches. RESULT(S): Integrins are a class of adhesion molecules that participate in cell-to-cell and cell-to-substratum interactions and are present on essentially all human cells. All mammalian eggs express integrins at their surface, and the integrin alpha 6 beta 1 serves as a sperm receptor that mediates sperm-egg binding. In addition, certain integrin moieties appear to be regulated within the cycling endometrium. Specifically, the expression of beta 1 integrins in the early proliferative phase is restricted to the glandular epithelium, whereas stromal cells also express beta 1 integrins in the midsecretory phase. The expression of beta 1 integrins increases at the time of implantation and remains elevated in the decidua during early pregnancy. A disruption of integrin expression is associated with certain types of infertility in women. The apical surface of the mural trophectoderm does indeed possess functional integrins, and trophoblast interactions with extracellular matrix proteins largely depend on the integrin family of adhesion receptors. CONCLUSION(S): Integrins play particularly important roles in both fertilization and embryogenesis, including the process of implantation.

Animals↗
PubMed1997

Effect of KN-62, a selective inhibitor of calmodulin-dependent kinase II, on mouse oocyte activation.

PURPOSE: Our purpose was to determine the association of calmodulin-dependent protein kinase II (CaMKII) with oocyte activation and to explore the network of protein kinases during mammalian fertilization. METHODS: Mouse M-II oocytes were collected after superovulation induced by PMSG-hCG injection. The oocytes were inseminated or artificially activated by Ca ionophore (A23187) or 12-O-tetradecanoyl phorbol 13-acetate (TPA). The effects of KN-62, a specific and selective inhibitor of calmodulin-dependent protein kinase II, on second polar body emission (2PBE), pronuclear formation (PF), and cortical granule exocytosis (CGE) during fertilization or after artificial oocyte activation were investigated. RESULTS: KN-62 inhibited 2PBE and PF after sperm or Ca ionophore inducing activation. Additionally, PF was inhibited by KN-62 after TPA activation, whereas KN-62 did not inhibit CGE in any case. KN-04, an inactive form of KN-62, did not inhibit significantly 2PBE, CGE, or PF. When oocytes were exposed to KN-62 after Ca ionophore or TPA activation, no inhibitory effects on 2PBE or PF were observed. CONCLUSIONS: The CaMKII activation that occurs after fertilization or artificial activation of mouse oocytes is presumably secondary to increases in the intracellular free calcium concentration. As determined by the use of inhibitor, CaMKII activity is associated with 2PBE and PF but not with CGE.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗