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2.
Eur Heart J Cardiovasc Imaging ; 25(6): 774-781, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38284416

ABSTRACT

AIMS: Higher left ventricular (LV) ejection fraction (EF) is related to unfavourable prognosis in patients with heart failure (HF) with preserved ejection fraction (HFpEF). The cause of this finding needs to be haemodynamically explained. Thus, we investigated this crucial issue from the perspective of LV-arterial (A) and right ventricular (RV)-pulmonary arterial (PA) coupling. METHODS AND RESULTS: Study patients were derived from our prospective cohort study of patients hospitalized due to acute decompensated HF and LVEF > 40%. We divided the 255 patients into three groups: HF with mildly reduced EF (HFmrEF), HFpEF with 50% ≤ LVEF < 60%, and HFpEF with LVEF ≥ 60%. We compared LV end-systolic elastance (Ees), effective arterial elastance (Ea), and Ees/Ea as a representative of LV-A coupling among groups and compared the ratio of tricuspid annular plane excursion to peak pulmonary arterial systolic pressure (TAPSE/PASP) as a representative of RV-PA coupling. All-cause death and readmission due to HF-free survival was worse in the group with a higher LVEF range. Ees/Ea was greater in HFpEF patients with LVEF ≥ 60% (2.12 ± 0.57) than in those with 50% ≤ LVEF < 60% (1.20 ± 0.14) and those with HFmrEF (0.82 ± 0.09) (P < 0.001). PASP was increased in the groups with higher LVEF; however, TAPSE/PASP did not differ among groups (n = 168, P = 0.17). In a multivariate Cox proportional hazard model, TAPSE/PASP but not PASP was significantly related to event-free survival independent of LVEF. CONCLUSION: HFpEF patients with higher LVEF have unfavourable prognosis and distinctive LV-A coupling: Ees/Ea is elevated up to 2.0 or more. Impaired RV-PA coupling also worsens prognosis in such patients. CLINICAL TRIAL REGISTRATION: URL: https://www.umin.ac.jp/ctr/index.htm Unique identifier: UMIN000017725.


Subject(s)
Heart Failure , Pulmonary Artery , Stroke Volume , Humans , Heart Failure/physiopathology , Heart Failure/diagnostic imaging , Male , Female , Stroke Volume/physiology , Aged , Prospective Studies , Pulmonary Artery/physiopathology , Pulmonary Artery/diagnostic imaging , Prognosis , Cohort Studies , Middle Aged , Risk Assessment , Echocardiography
3.
J Med Ultrason (2001) ; 50(1): 51-56, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36520249

ABSTRACT

PURPOSE: Trans-venous pacemaker leads are associated with worsening of tricuspid regurgitation (TR) after pacemaker implantation (PMI) in some cases. Recently, leadless pacemakers and thin ventricular pacemaker leads without a stylet lumen have become popular. However, the differences in the effects of these leads on TR are unclear. We investigated differences in the changes in TR in the early phase after PMI in patients with conventional leads, thin leads, and leadless pacemakers. METHODS: We enrolled 65 patients who underwent PMI (32 males, 79 ± 8 years), including 48 with trans-venous PMI (29 with conventional 6.0-Fr leads and 19 with 4.1-Fr thin leads) and 17 with leadless pacemakers. Transthoracic echocardiography was performed before and 1 month after PMI for assessment of conventional echocardiographic parameters and severity of TR by quantitative assessment. RESULTS: Atrial fibrillation was the most frequent indication for PMI in patients with leadless pacemakers (p = 0.015). In the before and 1 month after PMI comparison, left ventricular ejection fraction decreased after PMI only in the conventional lead group (p = 0.022). The TR effective regurgitant orifice area (EROA) decreased post PMI in the leadless (p = 0.002) and thin lead groups (p = 0.001), but not in the conventional lead group (p = 0.596). The change in TR EROA was greater in the leadless and thin lead groups as compared with the conventional lead group (p < 0.05). CONCLUSION: The decrease in TR EROA in the early phase after PMI differed according to the type of pacemaker lead. The thin lead might be beneficial for reduction of TR after PMI.


Subject(s)
Pacemaker, Artificial , Tricuspid Valve Insufficiency , Male , Humans , Tricuspid Valve Insufficiency/diagnostic imaging , Tricuspid Valve Insufficiency/therapy , Stroke Volume , Ventricular Function, Left , Echocardiography
4.
Eur Heart J Cardiovasc Imaging ; 24(3): 293-300, 2023 02 17.
Article in English | MEDLINE | ID: mdl-36464890

ABSTRACT

AIMS: Newly introduced drugs for heart failure (HF) have been reported to improve the prognosis of HF with preserved ejection fraction (HFpEF) in the lower range of left ventricular ejection fraction (LVEF). We hypothesized that a higher LVEF is related to an unfavourable prognosis in patients with HFpEF. METHODS AND RESULTS: We tested this hypothesis by analysing the data from a prospective multicentre cohort study in 255 patients admitted to the hospital due to decompensated HF (LVEF > 40% at discharge). The primary endpoint of this study was a composite outcome of all-cause death and readmission due to HF, and the secondary endpoint was readmission due to HF. LVEF and the mitral E/e' ratio were measured using echocardiography. In multicovariate parametric survival time analysis, LVEF [hazard ratio (HR) = 1.046 per 1% increase, P = 0.001], concurrent atrial fibrillation (AF) (HR = 3.203, P < 0.001), and E/e' (HR = 1.083 per 1.0 increase, P < 0.001) were significantly correlated with the primary endpoint. In addition to these covariates, angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) use was significantly correlated with the secondary endpoint (HR = 0.451, P = 0.008). Diagnostic performance plot analysis demonstrated that the discrimination threshold value for LVEF that could identify patients prone to reaching the primary endpoint was ≥57.2%. The prevalence of AF or E/e' ratio did not differ significantly between patients with LVEF ≥ 58% and with 40% < LVEF < 58%. CONCLUSION: A higher LVEF is independently related to poor prognosis in patients with HFpEF, in addition to concurrent AF and an elevated E/e' ratio. ACEI/ARB use, in contrast, was associated with improved prognosis, especially with regard to readmission due to HF. CLINICAL TRIAL REGISTRATION: https://www.umin.ac.jp/ctr/index.htm. UNIQUE IDENTIFIER: UMIN000017725.


Subject(s)
Heart Failure , Ventricular Function, Left , Humans , Stroke Volume , Cohort Studies , Prospective Studies , Angiotensin Receptor Antagonists/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Prognosis
5.
Sci Rep ; 12(1): 13978, 2022 08 17.
Article in English | MEDLINE | ID: mdl-35978001

ABSTRACT

Anemia and iron deficiency (ID) are common in patients with heart failure (HF) and intravenous (IV) administration of iron to patients hospitalized for decompensated HF with ID improves outcome. The diagnosis of ID in routine practice is based on serum ferritin and transferrin saturation (TSAT) but both have limitations; alternatives should be considered. Reticulocyte hemoglobin equivalent (Ret-He) reflects iron content in reticulocytes but its clinical utility in patients with HF remains uncertain. We prospectively enrolled 142 patients hospitalized for decompensated HF. Sixty five percent had ID as defined in current international guidelines. Ret-He was directly correlated with serum iron and ferritin concentrations and with TSAT. There was a poor relationship between quartile of Ret-He and HF hospitalization or death but increases or decreases in Ret-He between admission and discharge were associated with a worse outcome. The clinical utility of Ret-He for identifying ID and predicting response to IV iron and prognosis for patients with HF requires further investigation.


Subject(s)
Anemia, Iron-Deficiency , Heart Failure , Iron Deficiencies , Anemia, Iron-Deficiency/diagnosis , Ferritins , Heart Failure/diagnosis , Hemoglobins/analysis , Humans , Iron , ROC Curve , Reticulocytes
6.
Circ J ; 84(8): 1339-1345, 2020 07 22.
Article in English | MEDLINE | ID: mdl-32595175

ABSTRACT

BACKGROUND: Qing-Dai (QD) treatment of patients with ulcerative colitis (UC) sometimes causes pulmonary arterial hypertension (PAH). However, the relationship of QD treatment to pulmonary arterial systolic pressure (PASP) in patients with UC has not been clarified.Methods and Results:The 27 patients with UC who were screened for PAH by transthoracic echocardiography (TTE) and underwent repeat TTE at 1 year were analyzed in this prospective observational study. Mean age was 44.0 years old, and median follow-up duration was 392. During the follow-up, 21 patients continued QD treatment (continuous group) and 6 patients discontinued the treatment (discontinuous group). In all patients, no significant difference in PASP levels between baseline and at follow-up was observed (21.4 vs. 21.3 mmHg, P=0.802). Furthermore, the mean PASP of patients in the continuous group did not differ from baseline to follow-up (21.4 mmHg to 22.6 mmHg, P=0.212); however, in the discontinuous group mean PASP was significantly decreased (21.5 mmHg to 16.8 mmHg, P=0.005). Moreover, changes in PASP from baseline to follow-up differed between the continuous and discontinuous groups (+1.1 mmHg vs. -4.7 mmHg, P=0.004). In addition, multivariable analyses revealed that only the duration of oral QD at baseline affected the increase of PASP. CONCLUSIONS: In patients with UC, QD treatment may have an undesirable association with an increase in PASP.


Subject(s)
Arterial Pressure/drug effects , Colitis, Ulcerative/drug therapy , Drugs, Chinese Herbal/adverse effects , Pulmonary Arterial Hypertension/chemically induced , Pulmonary Artery/drug effects , Administration, Oral , Adult , Drugs, Chinese Herbal/administration & dosage , Female , Humans , Male , Middle Aged , Prospective Studies , Pulmonary Arterial Hypertension/diagnosis , Pulmonary Arterial Hypertension/physiopathology , Pulmonary Artery/physiopathology , Risk Factors , Time Factors , Treatment Outcome
7.
Circ Rep ; 2(6): 330-338, 2020 Apr 14.
Article in English | MEDLINE | ID: mdl-33693248

ABSTRACT

Background: Recently, the left ventricular early inflow-outflow index (LVEIO), calculated by dividing mitral E-wave velocity by the left ventricular outflow velocity time integral, has been proposed as a simple method for evaluating mitral regurgitation (MR). This study determined the optimal LVEIO threshold to assess severe MR with different etiologies and assessed its prognostic value. Methods and Results: The records of 18,692 consecutive patients who underwent echocardiography were reviewed. MR was classified into 4 groups: Grade 0/1, no, trivial, or mild MR; Grade 2, moderate MR; Grade 3, moderate to severe MR; and Grade 4, severe MR. The mean (±SD) LVEIO of Grades 0/1, 2, 3, and 4 was 3.6±1.4, 6.0±2.5, 7.4±3.1, and 9.5±2.8, respectively. An optimal LVEIO threshold of 5.4 was determined to distinguish moderate to severe or severe MR from non-severe MR (sensitivity 84%, specificity 91%). Kaplan-Meier survival analysis revealed high mortality in the group with LVEIO ≥5.4 (P=0.009, hazard ratio 1.833). This was found only in primary MR when separate analyses were performed according to etiology. Multivariate analysis revealed that LVEIO was an independent predictor for all-cause death only in primary MR. Conclusions: Using appropriate thresholds, LVEIO is a simple and useful method to diagnose severe MR regardless of etiology. LVEIO can also be useful for predicting prognosis in primary MR.

8.
J Cardiol Cases ; 20(6): 213-217, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31762836

ABSTRACT

Mid-diastolic forward flow velocity of transmitral flow (L wave) is known as a marker of diastolic dysfunction and is occasionally observed in patients with fluid retention, low heart rate, and atrial fibrillation (AF). However, how hemodynamic condition affects L wave is still unknown. An 81-year-old woman who underwent implantation of a DDD pacemaker due to complete atrioventricular block 38 years previously suffered from congestive heart failure and was admitted to our hospital. At the time of admission, electrocardiogram showed new-onset AF resulting in mode switch to VVI, and echocardiography showed a giant L wave. At the mid-term of the treatment, AF was converted to sinus rhythm resulting in mode switch to DDD, and pacemaker check-up was performed at pre- and post-cardioversion. During the pacemaker check-ups, L wave was assessed in various pacing rates. As pacing rate was increased, L wave altered according to heart rates and disappeared at 85 bpm in VVI with AF, whereas at 75 bpm in DDD. Through the treatment, L wave got smaller as fluid retention was improved and finally disappeared at the time of discharge. This case suggests that L wave is highly variable and affected by fluid volume, heart rate, and heart rhythm. .

9.
Circ J ; 83(2): 401-409, 2019 01 25.
Article in English | MEDLINE | ID: mdl-30555126

ABSTRACT

BACKGROUND: We used dual Doppler echocardiography to measure the time interval between the mitral and tricuspid valve opening (MO-TO time), which we expected would reflect the balance between left and right ventricular hemodynamics. Methods and Results: We prospectively enrolled 60 patients with heart failure (HF) and sinus rhythm. The MO-TO time was measured in addition to routine echocardiography parameters, invasive hemodynamic parameters and plasma B-type natriuretic peptide (BNP) level in all patients. Patients were divided into 2 groups based on the MO-TO time: MOP (mitral opening preceding tricuspid opening), and TOP (tricuspid opening preceding mitral opening) groups. We followed up the predefined adverse outcomes (cardiovascular [CV] death and hospitalization due to worsening HF) for 1 year. Pulmonary artery wedge pressure (PAWP) and mean pulmonary artery pressure (mPAP) were higher in the MOP than in the TOP group (P<0.001; P<0.001, respectively). The probability of an adverse CV outcome was higher in the MOP than in the TOP group (log-rank test; P=0.002). Addition of MOP improved the predictive power of univariate predictors (mitral E/A ratio and BNP) in the bivariate Cox analysis (P=0.017, P=0.024, respectively). CONCLUSIONS: MOP reflects pulmonary hypertension caused by left heart disease and has prognostic value in predicting adverse CV events in patients with HF.


Subject(s)
Heart Failure/diagnosis , Mitral Valve/physiopathology , Tricuspid Valve/physiopathology , Aged , Aged, 80 and over , Cardiovascular Diseases/etiology , Echocardiography, Doppler/methods , Female , Heart Failure/complications , Heart Failure/physiopathology , Hemodynamics , Humans , Hypertension, Pulmonary , Male , Middle Aged , Prognosis , Prospective Studies , Pulmonary Wedge Pressure , Time Factors
10.
Circ J ; 82(9): 2311-2316, 2018 08 24.
Article in English | MEDLINE | ID: mdl-30022769

ABSTRACT

BACKGROUND: Mid-diastolic mitral forward flow (L wave) is occasionally detected in heart failure (HF), but its correlates and prognostic value are still unknown, particularly in light of the type of HF, that is, HF with preserved or with reduced ejection fraction (HFpEF, HFrEF). Methods and Results: Of 151 patients with HF, L wave was observed in 23 of 82 HFrEF patients and in 25 of 69 HFpEF patients. Mitral early diastolic velocity (E), the ratio of E to mitral annulus velocity, and left atrial volume index were greater in the patients with L wave than in those without L wave in both subsets. Left ventricular (LV) mass index and relative wall thickness were greater in the patients with L wave than in those without L wave in the HFpEF group, but there was no difference in either parameter in the HFrEF group. Prognosis was poorer in those with L wave than in those without L wave both in the HFrEF and HFpEF groups. CONCLUSIONS: Appearance of L wave is associated with the degree of LV diastolic dysfunction, but there was a difference in LV geometrical correlates of the appearance of L wave between the HFpEF and HFrEF groups. Detection of L wave is suggestive of poor prognosis independent of LVEF in HF.


Subject(s)
Heart Failure/physiopathology , Hypertrophy, Left Ventricular/complications , Stroke Volume , Ventricular Dysfunction, Left/complications , Aged , Aged, 80 and over , Blood Flow Velocity , Diastole , Echocardiography, Doppler , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prognosis , Ventricular Remodeling
11.
Heart Vessels ; 33(7): 762-769, 2018 Jul.
Article in English | MEDLINE | ID: mdl-29357094

ABSTRACT

We investigated whether the interatrial septal (IAS) motion of each heartbeat which is observed by transesophageal echocardiography reflects left atrial pressure (LAP) in patients with atrial fibrillation (AF). We studied 100 patients (70 males, age 67 ± 9 years) who underwent catheter ablation for AF. The amplitude of IAS motion was measured using M-mode and averaged for five cardiac cycles. Left and right atrial pressures, the left to right atrial pressure gradient were directly measured during the catheter ablation. In patients with sinus rhythm during measurement, elevated mean LAP, larger maximum left to right atrial pressure gradient, and greater left atrial emptying fraction were associated with IAS motion. The optimal cut-off value of the IAS motion for predicting high LAP (mean LAP > 15 mmHg) was 8.5 mm (sensitivity 100%, specificity 70.1%) in patients with sinus rhythm during pressure measurement. In addition, all patients were divided into 6 groups based on rhythm during measurement and cutoff value of IAS motion. In patients with sinus rhythm during measurement, low IAS motion group had a highest prevalence of elevated LAP compared with high IAS motion group (64 vs. 0%, P < 0.0001). The amplitude of interatrial septal motion during sinus rhythm reflects left atrial pressure in patients with atrial fibrillation. Interatrial septal motion could be a new index to predict elevated left atrial pressure.


Subject(s)
Atrial Fibrillation/physiopathology , Atrial Function, Right/physiology , Atrial Pressure/physiology , Atrial Septum/physiopathology , Echocardiography/methods , Heart Atria/physiopathology , Aged , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Atrial Septum/diagnostic imaging , Catheter Ablation , Female , Follow-Up Studies , Heart Atria/diagnostic imaging , Humans , Male , Preoperative Period , Prognosis , Retrospective Studies
12.
Heart Vessels ; 32(1): 68-75, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27115147

ABSTRACT

Left ventricular (LV) diastolic dysfunction plays a crucial role in heart failure with reduced ejection fraction (HFrEF). LV stiffness is a main component of diastolic function, but its role and prognostic value in HFrEF patients remains unclear. This study aimed to determine whether diastolic wall strain (DWS) as a noninvasive and simple marker of LV stiffness can predict the prognosis of HFrEF patients who were administrated chronic beta blockade enough. We enrolled 75 HFrEF patients who were administrated chronic beta blockade. We evaluated the echocardiographic parameters and plasma brain natriuretic peptide (BNP) before the induction of beta blockade and also obtained pulmonary artery wedge pressure (PAWP) from the right heart catheterization. DWS was obtained from standard M-mode echocardiography as follows: DWS = [(LV posterior wall thickness (LVPWT) at end-systole - LVPWT at end-diastole)/LVPWT] at end-systole. DWS did not correlate with other echocardiographic parameters and PAWP. We defined primary outcome as HF hospitalization or cardiovascular death and followed for 7 years. The incidence rate was higher in low DWS than high DWS patients (p = 0.04). Other echocardiographic parameters could not be significant predictors of HFrEF outcome under the condition of enough beta blocker therapy. In multivariate analysis, DWS was the independent contributor to the event-free time. Impaired LV stiffness evaluated with DWS was associated with worse outcome and DWS might be an independent prognostic factor in HFrEF patients with chronic beta blockade.


Subject(s)
Adrenergic beta-Antagonists/therapeutic use , Heart Failure/diagnostic imaging , Heart Failure/drug therapy , Heart Ventricles/diagnostic imaging , Ventricular Dysfunction, Left/physiopathology , Aged , Biomarkers , Diastole/drug effects , Echocardiography , Female , Humans , Japan , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Natriuretic Peptide, Brain/blood , Observer Variation , Prognosis , Proportional Hazards Models , Stroke Volume
13.
J Cardiol Cases ; 14(6): 164-167, 2016 Dec.
Article in English | MEDLINE | ID: mdl-30546685

ABSTRACT

Although spontaneous coronary artery dissection (SCAD) is usually diagnosed by coronary angiography, diagnosis may be missed because of various presentations and imperfections of coronary angiography. We report a case of a 41-year-old female with pregnancy-related SCAD who presented with cardiac arrest. Initial coronary angiography was normal without intimal flap. Unexpectedly, 4 days after admission, SCAD in left main trunk was revealed with recurrent myocardial infarction. Intimal flap was sealed at the time of first angiography and this is an interesting point that made us report this case. SCAD is a rare but not negligible cause of not only acute myocardial infarction but also sudden cardiac arrest even if first coronary angiography is normal. .

14.
Appl Microbiol Biotechnol ; 71(6): 881-91, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16708193

ABSTRACT

When grown on solid agar medium, the mycelium of a filamentous fungus, Aspergillus oryzae, forms three morphologically distinct regions: the tip (T), white (W), and basal (B) regions. In this study, we developed the square-plate culture method, a novel culture method that enabled the extraction of mRNA samples from the three regions and analyzed the differential gene expression of the A. oryzae mycelium in concert with the microarray technique. Expression of genes involved in protein synthesis was predominant in the T region; relative expression was, at most, six times higher in the T region compared to the other regions. Genes encoding hypothetical proteins were expressed at high levels in the W and B regions. In addition, genes coding transporters/permeases were predominantly transcribed in the B region. By analyzing the expression patterns of genes in the three regions, we demonstrated the dynamic changes in the regulation of gene expression that occur along the mycelium of filamentous fungi. Consequently, our study established a method to analyze and screen for region-specific genes whose function may be essential for morphogenesis and differentiation in filamentous fungi and whose traits may be beneficial to the biotechnology industry.


Subject(s)
Aspergillus oryzae/genetics , Gene Expression Regulation, Fungal/genetics , Genes, Fungal/genetics , Aspergillus oryzae/growth & development , Blotting, Western , Cloning, Molecular/methods , Gene Expression Profiling/methods , Genomics/methods , Oligonucleotide Array Sequence Analysis/methods , Reverse Transcriptase Polymerase Chain Reaction , alpha-Amylases/genetics , alpha-Amylases/metabolism
15.
Mol Cell Biol ; 25(16): 7107-19, 2005 Aug.
Article in English | MEDLINE | ID: mdl-16055721

ABSTRACT

We cloned a testis-specific cDNA from mice that encodes a histone H1-like, haploid germ cell-specific nuclear protein designated HANP1/H1T2. The HANP1/H1T2 protein was specifically localized to the nuclei of murine spermatids during differentiation steps 5 to 13 but not to the nuclei of mature sperm. HANP1/H1T2 contains an arginine-serine-rich domain and an ATP/GTP binding site, and it binds to DNA, ATP, and protamine. To investigate the physiological role of HANP1/H1T2, we generated Hanp1/H1T2-disrupted mutant mice. Homozygous Hanp1/H1T2 mutant males were infertile, but females were fertile. Although a substantial number of sperm were recovered from the epididymides, their shape and function were abnormal. During sperm morphogenesis, the formation of nuclei was disturbed and protamine-1 and -2 were only weakly detectable in the nuclei. The chromatin packaging was aberrant, as demonstrated by electron microscopy and biochemical analysis. The mutant sperm exhibited deficient motility and were not competent to fertilize eggs under in vitro fertilization conditions; however, they were capable of fertilizing eggs via intracytoplasmic sperm injection that resulted in the birth of healthy progeny. Thus, we found that HANP1/H1T2 is essential for nuclear formation in functional spermatozoa and is specifically involved in the replacement of histones with protamines during spermiogenesis. At the time of submission of the manuscript, we found an independent publication by Martianov et al. (I. Martianov, S. Brancorsini, R. Catena, A. Gansmuller, N. Kotaja, M. Parvinen, P. Sassone-Corsi, and I. Davidson, Proc. Natl. Acad. Sci. USA 102:2808-2813, 2005) that reported similar results.


Subject(s)
Cell Nucleus/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/physiology , Fertility , Histones/metabolism , Nuclear Proteins/genetics , Nuclear Proteins/physiology , Spermatozoa/metabolism , Adenosine Triphosphate/chemistry , Adenosine Triphosphate/metabolism , Amino Acid Sequence , Animals , Arginine/chemistry , Base Sequence , Binding Sites , Cell Differentiation , Chromatin/metabolism , DNA/metabolism , DNA, Complementary/metabolism , DNA-Binding Proteins/chemistry , Dose-Response Relationship, Drug , Epididymis/metabolism , Female , Fertilization , Genetic Vectors , Guanosine Triphosphate/chemistry , Haploidy , Heterozygote , Homozygote , Male , Mice , Mice, Knockout , Microscopy, Electron , Models, Genetic , Molecular Sequence Data , Mutation , Nuclear Proteins/chemistry , Phylogeny , Protamines/metabolism , Protein Binding , Protein Structure, Tertiary , Sequence Homology, Amino Acid , Spermatids/metabolism , Testis/metabolism , Time Factors , Tissue Distribution
16.
Biosci Biotechnol Biochem ; 68(7): 1569-73, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15277763

ABSTRACT

The distribution of the secreted protein ribonuclease T1 (RntA) fused with the enhanced green fluorescent protein (EGFP), RntA-EGFP, was visualized in hyphae of Aspergillus oryzae in the presence of a protein transport inhibitor, brefeldin A, cytochalasin A, or nocodazole. During treatment with the protein transport inhibitors, the distribution of RntA-EGFP changed and distinct patterns of fluorescence accumulation were observed. The addition of brefeldin A caused RntA-EGFP fluorescence to appear in reticular networks, and the disruption of the polymerization of actin filaments by cytochalasin A caused an increase in RntA-EGFP fluorescence intensity in the hyphae without accumulation in a specific cellular component. In contrast, RntA-EGFP fluorescence was distributed in different parts of a hypha during treatment with nocodazole, a compound that depolymerizes microtubules. In addition, quantitative analysis was performed using the RntA-EGFP visualization system to analyze the relative amount of RntA-EGFP secreted into the culture medium during treatment with the protein transport inhibitors.


Subject(s)
Aspergillus oryzae/physiology , Green Fluorescent Proteins/physiology , Recombinant Fusion Proteins/physiology , Ribonuclease T1/physiology , Aspergillus oryzae/drug effects , Aspergillus oryzae/enzymology , Brefeldin A/pharmacology , Cytochalasins/pharmacology , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Hyphae/physiology , Microscopy, Fluorescence , Microscopy, Interference , Microtubules/physiology , Nocodazole/pharmacology , Protein Synthesis Inhibitors/pharmacology , Protein Transport/drug effects , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Ribonuclease T1/genetics , Ribonuclease T1/metabolism
17.
Biosci Biotechnol Biochem ; 67(2): 455-9, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12729022

ABSTRACT

A fusion gene encoding ribonuclease T1-EGFP (rntA-egfp) was constructed and expressed to use it as a tool for studies on the secretory pathway in Aspergillus oryzae. The successful secretion of the intact RntA-EGFP fusion protein was detected by fluorescence measurement and Western analysis. With use of the RntA-EGFP system, we were able to see high fluorescence at hyphal tips and observe concentrated fluorescence at septa in basal cells during growth at optimal conditions. Cold or heat shock during growth caused the accumulation of EGFP fluorescence in vacuoles.


Subject(s)
Aspergillus oryzae/physiology , Luminescent Proteins/genetics , Recombinant Fusion Proteins/analysis , Recombinant Fusion Proteins/metabolism , Ribonuclease T1/genetics , Aspergillus oryzae/genetics , Aspergillus oryzae/growth & development , Aspergillus oryzae/metabolism , Blotting, Western , Cold Temperature , Coumarins/chemistry , Green Fluorescent Proteins , Hyphae/metabolism , Luminescent Proteins/biosynthesis , Luminescent Proteins/chemistry , Luminescent Proteins/metabolism , Plasmids/genetics , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/genetics , Ribonuclease T1/biosynthesis , Ribonuclease T1/metabolism , Spectrometry, Fluorescence , Vacuoles/chemistry , Vacuoles/ultrastructure
18.
EMBO Rep ; 3(4): 367-72, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11943763

ABSTRACT

We report the isolation of 153 mouse genes whose expression is dramatically up-regulated during spermiogenesis. We used a novel variation of the subtractive hybridization technique called stepwise subtraction, wherein the subtraction process is systematically repeated in a stepwise manner. We named the genes thus identified as TISP genes (transcript induced in spermiogenesis). The transcription of 80 of these TISP genes is almost completely specific to the testis. This transcription is abruptly turned on after 17 days of age, when the mice enter puberty and spermiogenesis is initiated. Considering that the most advanced cells present at these stages of spermatogenesis are the spermatids, it is likely that we could isolate most of the spermatid-specific genes. DNA sequencing revealed that about half the TISP genes are novel and uncharacterized genes, confirming the utility of the stepwise subtraction approach for gene discovery.


Subject(s)
Spermatogenesis/genetics , Up-Regulation , Animals , Blotting, Northern , DNA, Complementary , Gene Library , Male , Mice , Nucleic Acid Hybridization , Organ Specificity , Spermatogenesis/physiology , Transcription, Genetic
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