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T Yuasa

Publications and source records attributed to T Yuasa.

287 records · Page 16Linked to original sources

Genetics of congenital nemaline myopathy.

Family patterns for 50 reported probands with congenital nemaline myopathy were compared with expected patterns derived from various possible genetic hypotheses. The disease had a high mortality in childhood but remained clinically stationary after this period. Some normal relatives showed nemaline rods on muscle biopsy. Chromosomes were normal in the two cases in which they were examined. Prenatal exposures appeared irrelevant to this disease. Autosomal recessive and X-linked recessive or dominant modes of inheritance were not compatible with the observed patterns, which could be explained by an autosomal dominant mode with a reduced penetrance. Normal relatives who carried rods were presumably unaffected heterozygotes of the same gene. The genetic ratio (the proportion of affected siblings) was 0.3, being short of the expected value, 0.5, probably because of the presence of these asymptomatic rod-bearing heterozygotes. While the pressure of natural selection was great in the patients who died or were severely disabled, the gene could be passed to the next generation by mildly affected patients or heterozygotes who remained unaffected.

Age Factors↗

Basic properties of calcium phosphate cement containing atelocollagen in its liquid or powder phases.

The basic properties of calcium phosphate cement (CPC) containing atelocollagen, the main component of the organic substrate in bone, were studied in an initial evaluation for the fabrication of modified CPC. The setting time of conventional CPC (c-CPC) was prolonged to over 100 min when c-CPC contained 1% or more atelocollagen. The diametral tensile strength (DTS) of c-CPC decreased linearly with the collagen content, descending to below the detection limit when the c-CPC contained 3% or more atelocollagen. Therefore, use of c-CPC as the base cement seems inappropriate for the fabrication of atelocollagen-containing CPC. In contrast, the cement set at 9-34 min when fast-setting CPC (FSCPC) was used as the base cement and contained 1-5% atelocollagen, respectively. Although addition of atelocollagen resulted in the decrease of DTS of the set mass, the DTS was approximately the same, 6-8 MPa, at contents of atelocollagen between 1% and 5%. When atelocollagen was added to FSCPC, the handling property was improved significantly. The paste also became more adhesive with increase in atelocollagen content. These properties are desirable for its use in surgical procedures since, for example, bony defects can be filled easily and without a space interposed between the bone and cement paste. Although there are some disadvantages for the addition of atelocollagen to CPC, it can be accepted as long as FSCPC was used as the base cement. We conclude that further evaluations of the effects of atelocollagen, such as biocompatibility, bone synthesis, and bone replacement behaviour should be done, using FSCPC as the base cement.

Biocompatible Materials↗

Histological remodeling in an ovine heart failure model resembles human ischemic cardiomyopathy.

Staged coronary embolization, causing myocardial microinfarctions, has been shown in dogs and sheep to cause chronic ischemic heart failure (HF) that resembles the hemodynamics of the human condition. However, its histopathological basis remains unclear. We examined the hypothesis that the ventricular remodeling seen in such sheep resembles the histopathology of human ischemic cardiomyopathy (ICM). Understanding the pathophysiology of this model will determine its place in the development of treatment strategies for HF. Global left ventricular (LV) damage resulting in HF was induced by staged coronary embolization in 11 sheep. Six others served as controls (normal control, NC). In HF sheep, the heart was harvested 6 months after LV ejection fraction (EF) had stabilized at <35%. Histopathological profiles were compared in biventricular transverse sections at midpapillary level using computed image analysis. LV end-diastolic volume increased in the HF group from 84.9+/-29 to 122.4+/-30.3 ml (n=11, P<.05), but myocytes across the LV wall in noninfarcted zones decreased (435.7+/-38.2 NC; 297.8+/-48.4/unit area HF; n=11, P<.0001) as did myocyte nuclear density (990.5+/-51.5 NC; 677.5+/-121.1/mm(2) HF, n=11, P<.0001). In contrast, LV replacement and interstitial fibrosis increased as did myocyte diameter in noninfarcted zones: 0.1+/-0.1 to 6.2+/-4.5% (P=.0049); 2.0+/-1.0 to 7.6+/-4.9% (P=.0149); and 10.0+/-0.5 to 15.9+/-2.2 microm (P<.0001), respectively. Although LV myocyte nuclear length increased (10.2+/-1.0 NC; 12.2+/-0.9 microm HF, n=11, P=.0006), right ventricular (RV) myocyte nuclear density and length did not alter. In this ovine chronic HF model, LV dilation and interstitial and myocyte remodeling resemble human ICM.

Animals↗

Physical performance tests after stroke: reliability and validity.

OBJECTIVE: To evaluate the reliability and validity of the modified physical performance tests for stroke survivors who live in a community. DESIGN: The subjects included 40 stroke survivors and 40 apparently healthy independent elderly persons. The physical performance tests for the stroke survivors comprised two physical capacity evaluation tasks that represented physical abilities necessary to perform the main activities of daily living, e.g., standing-up ability (time needed to stand up from bed rest) and walking ability (time needed to walk 10 m). RESULTS: Regarding the reliability of tests, significant correlations were confirmed between test and retest of physical performance tests with both short and long intervals in individuals after stroke. Regarding the validity of tests, the authors studied the significant correlations between the maximum isometric strength of the quardriceps muscle and the time needed to walk 10 m, centimeters reached while sitting and reaching, and the time needed to stand up from bed rest. CONCLUSIONS: The authors confirmed that there were significant correlations between the instrumental activity of daily living and the time needed to stand up from bed rest, along with the time needed to walk 10 m for the stroke survivors. These physical performance tests are useful guides for evaluating a level of activity of daily living and physical frailty of stroke survivors living in a community.

Activities of Daily Living↗

Computed tomographic findings of progressive supranuclear palsy compared with Parkinson's disease.

We investigated computed tomographic (CT) films of 4 pathologically documented cases of progressive supranuclear palsy (PSP) in which the clinical presentations were atypical and compared the findings with those of 15 patients with Parkinson's disease (PD). Dilatation of the third ventricle, atrophy of the midbrain tegmentum, and enlargement of the interpeduncular cistern toward the aqueduct were found to be the characteristic findings in PSP. Thus, radiological findings can be useful when the differential diagnosis between PSP and PD is clinically difficult.

Aged↗

Detection of alpha-fetoprotein mRNA in seminoma.

The classic testicular tumor marker alpha-fetoprotein (AFP) is associated with nonseminomatous germ cell tumors, including embryonal carcinoma, yolk sac tumor, and teratoma. AFP is not considered to be produced by pure seminoma. However, postmortem studies have demonstrated that 30 to 45% of patients who died of seminoma initially diagnosed harbored nonseminomatous metastases and had an elevated serum AFP. We analyzed AFP expression by immunohistochemistry and by nested reverse transcription-polymerase chain reaction (RT-PCR) in 10 seminomas, 3 embryonal carcinomas, and 1 immature teratoma, diagnosed by traditional clinical methods. Positive immunohistochemical staining was observed in all embryonal carcinomas and in the teratoma but not in the seminomas. AFP mRNA, however, was found in 6 of 10 seminomas, in all embryonal carcinomas, and in the teratoma. The nucleotide sequence of PCR products was identical with that of the AFP gene. We conclude that the analysis of AFP gene expression by nested RT-PCR would be useful for detecting minute quantities of nonseminomatous germ cell elements in classic seminoma. Moreover, the existence of AFP mRNA suggests the possibility that seminoma cells can differentiate into nonseminomatous germ cells.

Adult↗

Patterns of communication about AIDS among Hispanic and Anglo adolescents.

This study examined exposure to AIDS information from mass media and interpersonal communication among a nonprobability sample of Hispanic and Anglo lower middle-class adolescents. Subjects were drawn predominantly from community health clinics, word of mouth recruiting, public service announcements, churches, schools, and health fairs in San Diego County. Both Hispanic (n = 220) and Anglo (n = 159) youths reported substantial exposure to information about AIDS from both mass media and interpersonal communication. Hispanics watched more general television than Anglos, but had less exposure to newspapers and interpersonal communication with friends. Communication among friends was most consistently related to sociodemographic variables, with older, higher status persons and girls communicating to the greatest extent. Boys reported the greatest communication with family. Anglo youths had greater exposure to information about AIDS and condoms regardless of the medium of communication, while Hispanic adolescents had greater exposure to information on risks of IV drug use. Of the three main types of mass media, print and radio provided the most exposure to AIDS information. It is important for preventive medicine practitioners to exploit these differences in communication patterns when planning preventive intervention strategies that target specific adolescent populations.

Adolescent↗

A stable ovine congestive heart failure model. A suitable substrate for left ventricular assist device assessment.

Similarities in coronary circulation and heart size of sheep to that of humans are specific advantages of a sheep model of congestive heart failure (CHF). CHF was created in 11 sheep (51 +/- 4 kg) by selective sequential intracoronary injection of 90 microns microspheres under 1.5% isoflurane anesthesia. Hemodynamic characteristics were assessed at baseline, 4 weeks after establishment of CHF (ejection fraction [EF] < 35%, n = 11), and 26 weeks (n = 7) later. Baseline echocardiographic EF was 59 +/- 5% and fell to 26 +/- 5% after 5 +/- 2 embolizations. The left ventricular (LV) pressure-volume relationship showed stable decreases in LV end-systolic elastance (Ees) and preload recruitable stroke work. Intravenous infusion of dobutamine increased Ees from 2.8 +/- 1.7 to 4.3 +/- 2.2 and 4.5 +/- 1.4 mmHg/ml at heart rates of 140 and 160/min, respectively, at baseline. Increases of Ees (from 1.3 +/- 0.5 to 2.3 +/- 0.7 and 1.9 +/- 0.5 mmHg/ml at heart rates of 140 and 160/min, respectively) with dobutamine under CHF conditions did not exceed Ees values at baseline without dobutamine. This response to dobutamine infusion did not change 26 weeks after establishment of CHF. This stable ovine CHF model is proposed for studies on the long-term effects of cardiac assist devices.

Animals↗