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Biomedical subjects

Y Mishiro

Publications and source records attributed to Y Mishiro.

At least 37 records · Page 2Linked to original sources
PubMed1999

Influence of aging on systolic left ventricular wall motion velocities along the long and short axes in clinically normal patients determined by pulsed tissue doppler imaging.

Our objective was to evaluate the influence of aging on left ventricular (LV) regional systolic function along the long and short axes in clinically normal patients. We recorded LV wall motion velocity patterns at the mid-wall portion of the middle of the LV posterior wall in the parasternal long-axis view (short-axis direction) and at the endocardial portion of the middle of the LV posterior wall in the apical long-axis view (long-axis direction) with pulsed tissue Doppler imaging in 80 normal patients (age range 15 to 78 years). In all patients the LV pressure curve and its first derivative (dP/dt) were recorded. The systolic wave of the LV posterior wall motion velocity pattern exhibited 2 peaks, the first (Sw(1)) and second (Sw(2)) systolic waves. No significant changes were seen with aging in the percent LV fractional shortening determined by M-mode echocardiography, LV ejection fraction determined by left ventriculography, the peak Sw(1) and Sw(2) along the short axis, the peak Sw(2) along the long axis, and the peak dP/dt. The peak Sw(1) along the long axis correlated inversely with age (P <.0001) but did not correlate significantly with the peak dP/dt. These results suggest that shortening of the longitudinal fibers in early systole is impaired with increased age in healthy individuals. This impairment results in insufficient spherical change in the LV cavity, although global LV pump function and myocardial contractility are maintained.

Adolescent↗
PubMed1999

Regional left ventricular myocardial contraction abnormalities and asynchrony in patients with hypertrophic cardiomyopathy evaluated by magnetic resonance spatial modulation of magnetization myocardial tagging.

Global left ventricular (LV) pump function is generally preserved in patients with hypertrophic cardiomyopathy (HCM). However, it is unknown whether regional myocardial contractility is impaired, especially in nonhypertrophied regions. The purpose of this study was to evaluate regional LV myocardial contraction in patients with HCM using magnetic resonance (MR) spatial modulation of magnetization (SPAMM) myocardial tagging. The study group comprised 20 patients with asymmetric septal hypertrophy (HCM group) and 16 age-matched normal patients (control group), and data were collected using transthoracic M-mode and 2-dimensional echocardiography, and MR SPAMM myocardial tagging. The systolic strain ratio, maximum systolic strain velocity, and time from end-diastole to maximum systolic strain (deltaT) in the anterior, ventricular septal, inferior and lateral regions for 2 LV short-axis sections at the levels of the chordae tendineae and papillary muscles were measured at 50-ms intervals by MR myocardial tagging. The end-diastolic anterior and ventricular septal wall thicknesses and LV mass index were significantly different between the HCM and control groups. The systolic strain ratio for all 4 walls, particularly the anterior and ventricular septal regions, was significantly lower in the HCM group. In the HCM group, the maximum systolic strain velocity was significantly lower and deltaT was significantly shorter for all 4 walls, particularly the anterior and ventricular septal regions. The standard deviation for the deltaT, calculated from the deltaT for the 8 regions of the 2 LV short-axis sections, was significantly greater in the HCM group. In conclusion, regional LV myocardial contraction is impaired in both hypertrophied and nonhypertrophied regions, and systolic LV wall asynchrony occurs in patients with HCM.

Adult↗
PubMed1999

Evaluation of the hemodynamic relationship between the left atrium and left ventricle during atrial systole by pulsed tissue Doppler imaging in patients with left heart failure.

The objective of the present study was to evaluate the hemodynamic relationship between the left atrium (LA) and left ventricle (LV) during atrial systole in the presence of an elevated left ventricular end-diastolic pressure (LVEDP) and LV failure using pulsed tissue Doppler imaging (TDI). Fifty-three patients with LV systolic dysfunction and no regional LV asynergy were divided into 3 groups: relaxation failure group (RF, n=20) with a ratio of peak early diastolic to atrial systolic velocity of the transmitral flow (E/A) < or = 1; pseudonormalization group (PN, n=19) with 1 or =2. In addition, 20 normal patients (E/A > or = 1) were studied as a control group. The transmitral and pulmonary venous flow velocities were recorded by transesophageal pulsed Doppler echocardiography. The wall motion velocity patterns were recorded at the middle portion of the LV posterior wall (LVPW) and at the mitral annulus (MA) of the LVPW site in the apical LV long-axis view by transthoracic pulsed TDI. The LVEDP was significantly greater in the PN and RS groups than in the RF and control groups. The moan pulmonary capillary wedge pressure was greatest in the RS group. The percent fractional change of the LA area during atrial systole determined by 2-dimensional echocardiography was significantly lower in the RS group than in the PN group. The peak atrial systolic pulmonary venous flow velocity was significantly greater in the PN group than in the RS group. The peak atrial systolic motion velocity (Aw) at the LVPW was significantly lower in the PN and RS groups than in the RF and control groups. The Aw at the MA was significantly lower in the RS group than in the other groups. There was no significant difference in Aw between the LVPW and MA in the RS group, whereas Aw at the MA was significantly greater than that at the LVPW in the PN group. In conclusion, the measurements of Aw at the LVPW and MA can be used to noninvasively evaluate the hemodynamic relationship between the LA and LV during atrial systole in patients with LV failure.

Adult↗
PubMed1998

Left ventricular diastolic properties of hypertensive patients measured by pulsed tissue Doppler imaging.

Examination of left ventricular (LV) diastolic dysfunction in hypertensive patients has been based on parameters obtained from the transmitral flow velocity during pulsed Doppler echocardiography. However, these parameters are affected by loading conditions. We evaluated LV diastolic function along the longitudinal and transverse axes by pulsed tissue Doppler imaging (TDI) in 50 hypertensive (HT) patients and 36 age-matched healthy volunteers (N). Transmitral flow velocity was recorded by pulsed Doppler echocardiography. LV posterior wall motion velocity along the longitudinal and transverse axes also was recorded by pulsed TDI. In both groups, peak early diastolic velocity of the LV posterior wall (Ew) along the transverse axis (N: 15.8+/-5.2 cm/s, HT: 12.2+/-4.4 cm/s) was higher than that along the longitudinal axis (N: 12.7+/-3.1 cm/s, HT: 9.5+/-3.3 cm/s). Peak atrial systolic velocity of the LV posterior wall (Aw) along the longitudinal axis (N: 9.1+/-1.8 cm/s, HT: 9.7 +/-2.6 cm/s) significantly exceeded that along the transverse axis (N: 8.0+/-2.2 cm/s, HT: 8.4+/-2.4 cm/s) in both groups. The Ews were lower and the Aws were higher along both axes in the patient group than in the control group. The time intervals from the aortic component of the second heart sound to the peak of the early diastolic wave (IIA-Ews) along both the transverse (N: 142+/-18 ms, HT: 154+/-19 ms) and longitudinal (N: 151 16 ms, HT: 162+/-20 ms) axes were longer in the patient group. In 29 patients, Ews along both axes correlated negatively (transverse: r = -0.80, P < .0001; longitudinal: r = -0.71, P < .0001) and IIA-Ews correlated positively (transverse: r = 0.81, P < .0001; longitudinal: r = 0.74, P < .001) with the time constant of the LV pressure decay during isovolumic diastole. The Aws along both axes in the 24 patients without pseudonormalization in transmitral flow velocity correlated positively (transverse: r = 0.60, P < .001; longitudinal: r = 0.74, P < .0001) with the LV end-diastolic pressure. In conclusion, LV relaxation and filling along the longitudinal and transverse axes were impaired in many patients with hypertension. Pulsed TDI was useful for evaluating LV diastolic dynamics in this disease.

Aged↗
PubMed1997

Echocardiographic characteristics and causal mechanism of physiologic mitral regurgitation in young normal subjects.

BACKGROUND: It has become evident that mitral regurgitation (MR) is not uncommon in healthy subjects, and Doppler color flow mapping is a technique that imparts important information relevant to its detection. HYPOTHESIS: Using transthoracic echocardiography, this study evaluated the mechanism of physiologic MR in young normal subjects using transthoracic echocardiography. METHODS: The study population consisted of 48 young normal subjects (mean 21 +/- 5 years) with MR (physiologic MR group), 40 age-matched young normal subjects (mean 20 +/- 5 years) without MR (control group), 45 patients (mean 41 +/- 15 years) with mitral valve prolapse with MR (MVP group), and 27 patients (mean 59 +/- 13 years) with ruptured chordae tendineae (rupture group). RESULTS: Men were predominant in the rupture group, whereas there were no significant gender differences in the other three groups. Left ventricular end-diastolic dimension and left atrial systolic dimension were slightly smaller in the physiologic MR group than in the control group, but were significantly smaller than those in the MVP and rupture groups. The ratio of the maximum anteroposterior diameter to the maximum transverse diameter on chest radiography and the ratio of the short- to long-axis diameter of the left ventricular cavity at end diastole, determined from two-dimensional short-axis echocardiogram, were significantly lower in the physiologic MR group than in the other three groups. Mitral regurgitation occurred more frequently at the posteromedial commissural site in the physiologic MR and MVP groups, whereas there was no preference for location in the rupture group. Early systolic MR was often observed in the physiologic MR group, whereas pansystolic MR was common in the MVP and rupture groups. CONCLUSION: As a causal mechanism for physiologic MR detected in young normal subjects, "flattening" of the thorax during growth may cause morphologic abnormalities of the left atrial and ventricular cavities, resulting in spatial imbalance of the mitral complex and resulting in malcoaptation of the valve.

Adult↗
PubMed1997

Expression of highly polysialylated NCAM (NCAM-H) in developing and adult chicken auditory organ.

Neural cell adhesion molecule (NCAM) is highly polysialylated (NCAM-H) in developing tissues, and recent findings suggest that NCAM-H is more essential for neural development than poorly sialylated NCAM (NCAM-L). In order to understand the precise role of NCAM-H in developing and adult inner ears, the immunohistochemical localization of NCAM-H in developing and adult chicken inner ears was examined using a monoclonal antibody which is only specific for NCAM-H. Immunoreactivity of NCAM-H was initially observed on acoustic ganglion at stage 24, when peripheral (afferent) fibers begin to emerge from the ganglion cells. At stage 38, when peripheral fibers form synapses with hair cells, NCAM-H was observed on peripheral fibers and the base of hair cells in the auditory epithelium. At stage 42, NCAM-H on nerve fibers disappeared, and only some acoustic ganglion cells were still positive for NCAM-H. This immunostain on ganglion cells was retained after birth. These data are consistent with the hypothesis that NCAM-H specifically regulates the afferent nerve fibers' growth and synaptogenesis with hair cells during inner ear development and may be associated with processing of auditory information and neuronal plasticity.

Animals↗
PubMed1997

Expression of neurite outgrowth factor and gicerin during inner ear development and hair cell regeneration in the chick.

Several cell adhesion molecules are expressed in the developing inner ear. The present study focused on gicerin, a novel member of the immunoglobulin superfamily, in an attempt to improve our understanding of the development and regeneration of chick inner ear. Gicerin is known to homophilically interact with itself and to bind to neurite outgrowth factor (NOF). The data collected herein show that gicerin is highly expressed in auditory epithelium and acoustic ganglion during early embryogenesis. The immunoreactivity of gicerin in the auditory epithelium decreases more rapidly than that in the acoustic ganglion as the mature hair cells become distinguishable. At the post-hatch stage, the expression of gicerin is not observed. In contrast, NOF was expressed on the basement membranes around the auditory epithelium, and in the acoustic ganglion during development and after birth, but not in the auditory epithelium. Following noise damage, gicerin is transiently re-expressed on the damage receptor epithelium when active cell proliferation is observed in the epithelium. This positive reaction immediately disappears as immature short hair cells appear. These results suggest that gicerin may be associated with cell proliferation in the auditory epithelium, and play a role in neurite extension of the acoustic ganglion cells in conjunction with NOF.

Acoustic Stimulation↗
PubMed1997

Unusual left ventricular wall motion and a loud added sound during the isovolumic relaxation period in a patient with hypertensive heart disease.

A 69 year old woman with hypertensive heart disease had a loud added sound which coincided with a sudden interruption of the early diastolic motion of the left ventricular posterior wall, as visualised by M mode echocardiography, and came just before early diastolic transmitral flow, as measured by a pulsed Doppler echocardiogram. Early diastolic motion velocity from the base to the middle of the posterior wall, assessed by pulsed Doppler tissue imaging, was markedly high and sharp, and its peak coincided with the sound. A notch, similar to that in the posterior wall motion, occurred in the left ventricular pressure curve during early diastole. No intraventricular flow signal was detected during the isovolumic relaxation period, as measured by pulsed and colour Doppler imaging. The added sound was probably produced by impact between the dilated heart, with a relaxation abnormality, and the extracardiac structures during the isovolumic relaxation period.

Aged↗
PubMed1997

[A case report of bilateral perilymph fistula in an adult, with literature review].

Adult bilateral perilymph fistula (PLF) is rare. We report a case of a 55-year-old man who suffered from sudden bilateral hearing loss after blowing his nose. On the first day, he also had bilateral tinnitus but no vertigo. However, he gradually developed vertigo, and nystagmus to the left side began to appear in the following days. Exploratory bilateral tympanotomies were performed and perilymph fistulas were observed at the round window niche in both ears. The round windows were obliterated with fascia of the temporal muscles. After the operation no changes were found in both sides on a pure tone audiogram even at a one-year follow-up. The literature was reviewed and several features were statistically analyzed. In the adult bilateral PLF group, the proportion of the cases in which the cause of PLF was clear was significantly higher than that in the adult unilateral PLF group, but the other clinical features were almost the same. The results suggest that in adults the occurrence of bilateral and unilateral PLF could depend on the level of pressure applied to the middle or inner ear. On the other hand, in the child PLF group, the ratio of bilateral involvement was considerably higher than that in the adult PLF group, and in most cases the PLF was associated with middle and/or inner ear malformations. Healing in the child bilateral PLF group was poor than that in the adult PLF group. Those results suggest that the etiology of bilateral PLF in children may be considerably different from that of adult PLF.

Age Factors↗
PubMed1997

[Sensorineural hearing loss caused by middle ear surgery].

It is well known that sensorineural hearing loss rarely occurs after middle ear surgery. Five cases of postoperative sensorineural hearing loss were reviewed. These operations amounted to 0.9% of all middle ear operations in which the first author was involved. The causes of hearing loss were believed to be labyrinthitis through the fistula in cholesteatoma case 1, and acoustic trauma from the bone-cutting burr in cases 2 and 3. In cases 4 and 5 postoperative sensorineural hearing loss occurred several months after stapes surgery and the causes of hearing loss were unknown. On the basis of the available literature discussion focused on management of labyrinthine fistula, the acoustic effect of the bone-cutting burr and the possibility of sensorineural hearing loss caused by stapes surgery.

Aged↗
PubMed1997

Non-Hodgkin's lymphoma of Waldeyer's ring as a manifestation of lymphoproliferative diseases associated with human T-cell leukemia virus type 1 in southwestern Japan.

Adult T-cell leukemia/lymphoma (ATL) usually presents with node- and/or cutaneous-based diseases, with a leukemic picture. It is not clear whether ATL initially manifests with lesions in Waldeyer's ring (WR) in an ATL-endemic area. In the present study, we examined distributions of immunophenotypes and the presence of human T-cell leukemia virus type 1 (HTLV-1) and Epstein-Barr virus (EBV) genomes in 62 cases of non-Hodgkin's lymphoma (NHL) of WR (NHL-WR) from two areas of Japan: Osaka, an ATL-nonendemic area (25 cases), and Okinawa, an ATL-endemic area (37 cases). In both areas, age ranged from 10 to 94 years (median, 64 yr), with a male-to-female ratio of 1.81:1. Twelve patients were in Stage I, 34 in Stage II, and 6 in Stage III; stage was unknown in 10. The 25 Osaka cases were B-cell type (16 diffuse immunoblastic type (DIB), 8 diffuse large cell predominantly noncleaved cell (DLNC), 1 cleaved cell (DLC)). Of the 37 Okinawa cases, 20 were B-cell type (3 DIB, 10 DLNC, 2 DLC, 5 other). The remaining 17 cases showed T-cell phenotype (4 DIB, 3 DLC, 3 diffuse large cell not otherwise specified, 7 other). There was a significant difference in the distribution of immunophenotypes between these two areas (P < .001). Combined studies of polymerase chain reaction (PCR) and in situ hybridization revealed the presence of EBV genome in 1 (4%) of 24 Osaka cases, 2 (13%) of 16 B-cell NHLs from Okinawa, and 3 (23%) of 13 T-cell NHLs from Okinawa. HTLV-1 proviral genome was found in 11 (85%) of 13 T-cell lymphomas from Okinawa but could not be detected in B-cell lymphomas from Osaka and Okinawa. Combined clinical, histologic, serologic, and PCR findings suggest that NHL-WR in an ATL-endemic area could be an initial manifestation of ATL.

Adolescent↗
PubMed1996

[Statistical analysis of recovery from sudden deafness among treatment groups].

This study examined 131 patients with idiopathic sudden deafness in whom the averaged of five frequency hearing levels was greater than 60dB. Since combined pharmacotherapy has been used in the treatment of idiopathic sudden deafness, it is hard to make a quantitative analysis of single-drug efficacy. We used a single-drug treatment in turn to assess the drug efficacy within 30 days after the onset. There was no significant difference among patients treated within 6 days and not less than 7 days after the onset with steroid therapy, PGE1 therapy, and defibrinogenation therapy. Similarly, there was no significant difference among patients treated within 6 days and not less than 7 days after the onset with steroid and defibrinogenation combined therapy, steroid and PGE1 combined therapy, and steroid, defibrinogenation and Lasix-Vitamin combined therapy. In case of no steroid effect, treatment with defibrinogenation, PGE1 and Lasix-Vitamin therapy could achieve hearing improvement.

Adolescent↗
PubMed1996

[Tympanoplasty on only hearing ears].

Tympanoplasty on only hearing ears was performed on 11 patients in Osaka University Hospital and Osaka Rosai Hospital during 1986 1994; this was 0.68% of all cases of middle ear surgery. The patients consisted of 5 with cholesteatoma, 5 with chronic otitis media and 1 with cholesterin granuloma. The mean age was 47.6 years (13-68 years) and the mean follow-up period was 2 years and 7 months (6 months-4 years). Postoperative hearing results was obtained in 9 patients (81.8%) according to the criteria of Otology Japan (1987), and all ears were dry at the final examination. Compared with the preoperative hearing level, postoperative hearing level showed improvement in 3 cases, not in 7 cases (within difference of 5 dB) and deterioration by 10-15 dB in 1 case. Although indications for surgery on only hearing ears are still controversial, we suggest the following: 1) patients with cholesteatoma should be operated on in the ordinary way; 2) patients with chronic otitis media should be operated on only by myringoplasty; 3) all patients must be operated on very carefully by skillful surgeons.

Adolescent↗
PubMed1995

The presence and subtype of Epstein-Barr virus in B and T cell lymphomas of the sino-nasal region from the Osaka and Okinawa districts of Japan.

BACKGROUND: Association between Epstein-Barr virus (EBV) and human malignancies, including sino-nasal lymphoma (SNL), has been suggested. EBV-associated malignancies have been reported to show distinct geographic distribution. EXPERIMENTAL DESIGN: In the present study, the presence of an EBV genome and its subtypes (type A and B) were examined in 52 cases of sino-nasal lymphomas of B and T cell type collected from two areas of Japan: Osaka, situated on the mainland, and Okinawa, islands situated in a southwest part of Japan with a subtropical climate. Our previous epidemiologic study showed that the frequency of nasal T cell lymphoma was 3.5 times higher in Okinawa than in Osaka. RESULTS: There were no prominent differences in age distribution or sex ratio between these two areas: age ranged 8 to 85 (median 54) years, with a male to female ratio of 1.26:1. Immunophenotypically, 27 cases were B cell type (20 Osaka, 7 Okinawa), 20 were T cell type (9 Osaka, 11 Okinawa), and 5 were undefined. By PCR, EBV positivity in throat washings of normal individuals in Osaka and Okinawa was 52 and 53%, respectively, with marked preponderance of subtype A in both areas. EBV genome was found in 6 of 15 cases (40%) and 4 of 5 cases (80%) of nasal B and T cell lymphomas in Osaka and in 3 of 7 cases (43%) and 7 of 7 cases (100%) in Okinawa, showing the different frequencies of positivity by immunophenotype but not by district. All but one patient had type A EBV. The in situ hybridization confirmed the results of PCR as positive signals in the nucleus of proliferating cells. Latent membrane protein-1 was expressed in 13 of 22 cases (59%). CONCLUSIONS: These findings suggest that EBV, exclusively type A, might be a causative factor in sino-nasal lymphoma of not only T cell but also B cell type in Japan.

Adolescent↗
PubMed1994

[Tympanoplasty in cholesteatoma otitis media with normal hearing].

Thirteen cholesteatomas, with hearing within 20dB, were operated on from 1985 to 1992. Their mean age was 22.1 years, and the mean follow-up period 1.8 years. Eleven cases were pars flaccid type, and 2 cases pars tensa type. Tympanoplasties were performed by the canal down method (4 cases), the canal up method (3 cases), both transmeatal atticotomy and scutumplasty (4 cases) and both the canal down method and mastoid obliteration (2 cases). Postoperative hearing results of three averaged speech frequencies were within 20dB in 11 cases and between 20 and 30dB in 2 cases. No recurrent cholesteatoma or extrusion of columella occurred during the follow-up period. One of the cases operated on by the canal down method showed postoperative mastoid cavity problems, and one of the cases operated on by the canal up method showed retraction of the pars flaccida. These findings prompted us to operate on cholesteatoma cases with normal hearing and to recommend tympanoplasty with transmeatal atticotomy and scutumplasty.

Adolescent↗
PubMed1989

[Indole production in human whole saliva].

It is known that between saliva and oral microorganisms there are close relations. To investigate the salivary factors that influence the metabolism of oral microorganisms, the production and degradation of indole were studied in several salivary supernatants or salivary ultrafiltrates. Washed salivary sediments were mixed with the supernatants or the ultrafiltrates containing tryptophan or indole. After incubation at 37 degrees C for 48 hours, the indole was extracted by petroleum ether and determined spectrophotometrically. The results obtained were as follows: 1) The amount of indole produced in the raw supernatants was generally greater than that produced in the heated supernatants. 2) The production and the degradation of indole in the ultrafiltrates varied according to the saliva samples. 3) Only a small amount of indole was produced when tryptophan was not added to the ultrafiltrates. 4) When the ultrafiltrate was preheated at 98 degrees C, the indole production slightly decreased for only ten minutes. 5) The optimum pH for indole production in the ultrafiltrate was within the range from 7.0 to 8.5 in the presence of 20mM of Good's buffer (MES, MOPS, TAPS). 6) The highest indole production was observed when MOPS (pH7.7) was added at the concentration of 20mM to the ultrafiltrate. 7) The amount of indole production was mainly influenced by salivary sediment, and it was also affected by the ultrafiltrate.

Humans↗
PubMed1989

[Effects of salivary ultrafiltrates on the production of phenol from tyrosine by oral microorganisms].

The metabolism of oral microorganisms is known to correlate with oral diseases. Protein degradation by oral microorganisms is usually followed by the production of phenol from tyrosine. The purpose of this study is to clarify the effect of salivary ultrafiltrates [MW: less than 10,000, 1,000-10,000 (intermediate fraction), less than 1,000, less than 500] on the production or the decomposition of phenol by oral microorganisms. Salivary sediment and salivary ultrafiltrate, the molecular weight of which is less than 10,000 unless otherwise stated, were incubated at 37 degrees C for 24 hours with tyrosine or phenol at a final concentration of 2.5 mg/100 ml. After incubation, the phenol produced (or remained) was extracted with ether and determined spectrophotometrically. Phenol production by oral microorganisms was not seen in the non-dialyzable fraction of saliva even when tyrosine was added. It was confirmed that the presence of the salivary ultrafiltrates was essential for the production of phenol by oral microorganisms. Phenol production in the salivary ultrafiltrate was further increased with the addition of tyrosine or non-dialyzable fraction of saliva. Phenol disappeared within 48 or 72 hours after the salivary sediment was incubated with phenol. The decomposition of phenol was inhibited with the salivary ultrafiltrate. Phenol production was enhanced with the addition of Good's buffer. Optimum pH of phenol production by oral microorganisms in the ultrafiltrate of saliva was within the range from 6.5 to 7.0 in the presence of Good's buffer (MOPS). Phenol production decreased with the reduction of the molecular weight of the salivary ultrafiltrates. The phenol production was increased when the intermediate fraction was added to the ultrafiltrate (MW: less than 1,000). The increase of the phenol production was considered to be due to the peptides in the intermediate fraction.

Bacteria↗