Biomedical subjects

S Uehara

Publications and source records attributed to S Uehara.

At least 37 records · Page 2Linked to original sources

PubMed2001

Observed versus expected rates of unbalanced fetal karyotype at second trimester amniocentesis when one parent carries a balanced translocation.

Our purpose is to evaluate a model proposed by Stene et al. for estimating the risk of unbalanced progeny at the time of second trimester amniocentesis for 114 pregnancies of 71 couples, who are carriers of a reciprocal translocation. The overall estimated risk was 18%, 1.26 times higher than the observed risk (14%). There were no unbalanced fetuses in the 19 pregnancies of the no-risk group. In the low-risk group, the observed risk was highly correlated with the estimated risk. However, the estimated risks in the medium- and high-risk groups were much higher than the observed risks (2- and 1.5-fold). In the group ascertained through spontaneous abortions, the average estimated risk was 1.9 times higher than the observed risk. Although the model is useful in estimating individual empirical risks, it may be necessary to consider the type of ascertainments and add some modifications to calculate the risks in the second trimester.

Adult↗

PubMed2001

Enhancement of plasminogen activator activity stimulated by LPS in gingival fibroblasts of individuals with Down syndrome.

Individuals with Down syndrome (DS) have a high prevalence of periodontal disease, which develops early and progressed rapidly and extensively, in comparison with healthy controls. The severe periodontal disease in individuals with DS has been considered to result from abnormal factors in their host responses. The mechanisms involved in the periodontal inflammatory processes in individuals with DS are not fully understood. Plasminogen activators (PA) are serine proteases that are well known for their part in the initiation of the fibrinolytic cascade leading to the generation of plasmin in periodontal homeostasis, including fibrinolysis and connective tissue remodeling. The PA-plasmin system affects the progression of periodontal disease. In the present study, we examined the effects of the levels of PA activity stimulated with lipopolysaccharide (LPS) in the gingival fibroblasts from donors with DS (DGF). The levels of PA activity without LPS were low in the DGFs, the same as that in the gingival fibroblasts from donors of healthy controls (NDGF). In contrast, the levels of PA activity with LPS in DGFs were significantly higher than that in the NDGFs. These results suggested that PA plays an important role in inducing extensive and rapid inflammation in the periodontal disease in individuals with DS.

Adolescent↗

PubMed2001

[A case of gliomatosis cerebri: remarkable improvement after radiation therapy].

A 30-year-old female case of gliomatosis cerebri, which showed remarkable improvement after radiation therapy is reported. The lesion had spread widely in the frontal and parietal lobes of both sides, causing diffuse swelling of the cerebral hemispheres. A specimen obtained by open biopsy revealed diffuse proliferation of astrocytic (GFAP positive) tumor cells, associated with little tissue destruction. After whole-brain radiation of 60 Gy, the lesion shrunk gradually but markedly. Hemiparesis and mild dementia, which the patient had experienced before treatment, subsided completely within 6 months, until she was able to restart her job as a dentist. Although gliomatosis cerebri is thought to have a poor prognosis, this case demonstrates the potential of radiotherapy for this disease. Factors which may lead to a better outcome are discussed.

Adult↗

PubMed2001

Pathophysiological roles of endogenous endothelin-1 in dogs with chronic heart failure produced by rapid right ventricular pacing.

This study was designed to analyze the pathophysiological role of the endogenous endothelin (ET) system and the therapeutic approach to congestive heart failure (CHF) with ET(A)/ET(B) receptor antagonists in a canine CHF model. After 3 weeks of rapid right ventricular pacing (240 beats/min), concentrations of immunoreactive ET-1 in dogs increased approximately 2-fold in plasma and in the left and right ventricles but not in the lung. There were no meaningful changes in the density and affinity of total ET receptors, or in the ratio of ET(A) to ET(B) receptors. To clarify the functional role of endogenous ET, we examined the effects of acute injection of J-104132 (1 and 3 mg/kg i.v.), an ET(A)/ET(B) receptor antagonist, on cardiovascular and renal function in dogs with CHF. Compared with vehicle, J-104132 at both doses significantly decreased pulmonary artery pressure (PAP), pulmonary capillary wedge pressure (PCWP), and mean arterial pressure (MAP), and increased cardiac output (CO) and renal blood flow. J-104132 had no effects on heart rate and cardiac contractility. In addition, we examined whether J-104132 has an additive effect in the presence of enalaprilat. J-104132 (1 mg/kg i.v.) administered after enalaprilat (0.05 mg/kg i.v.) induced further decreases in MAP, PCWP and PAP, and further increases in CO, resulting in further decreases in total peripheral resistance. These results indicate that the endogenous ET system is exaggerated in CHF and has a detrimental effect on cardiac function. Therefore, J-104132 given alone or as combination therapy may play a beneficial role in the treatment of CHF in humans.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2001

[Neoadjuvant chemotherapy for advanced gastric cancer with para-aortic lymph node metastasis].

Neoadjuvant chemotherapy was applied to patients with advanced gastric cancer and confirmed para-aortic lymph node metastasis. Subjects were 7 patients. The response to the neoadjuvant chemotherapy was a PR in 5 cases, MR in 2 cases for the primary lesion and CR in 2 cases PR in 5 cases for the para-aortic lymph node metastasis. The grades of histological response assessed on the resected specimen were Grade 0 in three cases, Grade 1a in one, Grade 1b in one and Grade 2 in two. While there was no significant difference in survival rate between patient groups with and without neoadjuvant chemotherapy, the 2-year survival rate in patients with neoadjuvant chemotherapy was a good 42.9%, compared with 10% in patients groups without neoadjuvant chemotherapy. It is concluded that a better prognosis can be expected for advanced gastric cancer patients with neoadjuvant chemotherapy.

Aged↗

PubMed2001

[Developmental consultation conducted by Yokohama Rehabilitation Center at health welfare offices--combination of early impairment detection and support nursing].

We report here the results of developmental consultation carried out at Yokohama City health welfare offices. From October 1992 to March 1998, we consulted 666 cases aged 1 to 56 months old. We made full use of the reflex rolling I of Vojta for therapeutic diagnosis, and conducted physical training for babies. The reflex rolling I was very useful in diminishing the mother's anxiety about nursing problems such as weak suckling, sleep disturbance and constipation. Since it is important to combine the early detection of impairments with the support for nursing, advices to achieve better development were given to the parents and children. In our developmental consultation we could select babies at risk early and thereby start therapy for them smoothly.

Child Development↗

PubMed2001

Monte Carlo track structure for radiation biology and space applications.

Over the past two decades event by event Monte Carlo track structure codes have increasingly been used for biophysical modelling and radiotherapy. Advent of these codes has helped to shed light on many aspects of microdosimetry and mechanism of damage by ionising radiation in the cell. These codes have continuously been modified to include new improved cross sections and computational techniques. This paper provides a summary of input data for ionizations, excitations and elastic scattering cross sections for event by event Monte Carlo track structure simulations for electrons and ions in the form of parametric equations, which makes it easy to reproduce the data. Stopping power and radial distribution of dose are presented for ions and compared with experimental data. A model is described for simulation of full slowing down of proton tracks in water in the range 1 keV to 1 MeV. Modelling and calculations are presented for the response of a TEPC proportional counter irradiated with 5 MeV alpha-particles. Distributions are presented for the wall and wall-less counters. Data shows contribution of indirect effects to the lineal energy distribution for the wall counters responses even at such a low ion energy.

Algorithms↗

PubMed2000

Adenovirus-mediated in utero gene transfer in mice and guinea pigs: tissue distribution of recombinant adenovirus determined by quantitative TaqMan-polymerase chain reaction assay.

Fetal somatic cell gene therapy could become an attractive solution for some congenital genetic diseases or the disorders which manifest themselves during the fetal period. We performed adenovirus-mediated gene transfer to mice and guinea pig fetuses in utero and evaluated the efficiency of gene transfer by histochemical analysis and a quantitative TaqMan-polymerase chain reaction (TaqMan-PCR) assay. We first injected a replication-deficient recombinant adenovirus containing the Escherichia coli LacZ gene driven by a CAG promoter (AxCALacZ) into pregnant mice through the amniotic space, placenta, or intraperitoneal space of the fetus. Histochemical analysis showed limited transgene expression in fetal tissues. We then administered AxCALacZ to guinea pig fetuses in the late stage of pregnancy through the umbilical vein. The highest beta-galactosidase expression was observed in liver followed by moderate expression in heart, spleen, and adrenal gland. The transgene expression was also present in kidney, intestine, and placenta to a lesser degree. No positively stained cells were observed in lung, muscle, or pancreas except in the vascular endothelium of these organs. Quantitative measurement of recombinant adenoviral DNA by the TaqMan-PCR assay showed that the vast majority of the injected viruses was present in liver. The current study indicated that adenovirus-mediated gene transfer into guinea pig fetus through the umbilical vein is feasible and results in efficient transgene expression in fetal tissues. The experimental procedures using pregnant guinea pigs might serve as a good experimental model for in utero gene transfer. Since our TaqMan-PCR assay detects the LacZ gene, one of the most widely used reporter genes, it may be generally applicable to adenovirus quantification in various gene transfer experiments.

Adenoviridae↗

PubMed2000

X-chromosome inactivation in the human trophoblast of early pregnancy.

To investigate X-chromosome inactivation (XCI) in human trophoblasts during early pregnancy, trophoblast genomic DNA was extracted and analyzed for a Bst XI restriction endonuclease site polymorphism in the X-linked phosphoglycerate kinase gene, after digestion with methylation-sensitive Hpa II (control samples were digested instead with Afa I). Six villous trophoblast DNA samples were informative for the polymorphism (ie, heterozygous) and were derived from women homozygous for the polymorphism. These samples were then evaluated for XCI. In five of the six samples with Hpa II predigestion, the sizes of the two heterozygous band peaks differed; maternal X-chromosome (X(M))-derived alleles showed smaller peak sizes than paternal X-chromosome (X(P))-derived alleles, but the differences varied in degree. In samples obtained by microdissection from formalin-fixed, paraffin-embedded tissues (30 samples from different anchoring villi, and 38 samples from different branch villi), monoclonal band patterns of X(P)-derived alleles were observed more frequently than those of X(M)-derived alleles, but almost half of the samples showed polyclonal patterns. Our results suggest that a skewing of XCI exists in the human trophoblast; however, the degree of nonrandomness due to predominant X(P) inactivation appears to be restricted. It is probable that transcription of the X inactivation center (XIC) begins earlier in mice than in humans.

Clone Cells↗

PubMed2000

Induction of endometrial cycles and ovulation in a woman with combined 17alpha-hydroxylase/17,20-lyase deficiency due to compound heterozygous mutations on the p45017alpha gene.

OBJECTIVE: To describe the case of a Japanese woman with combined 17alpha-hydroxylase/17,20-lyase deficiency (congenital adrenal hyperplasia type V) and to discuss possible therapeutic procedures in such patients. DESIGN: Case report. SETTING: University hospital. PATIENT(S): A 26-year-old woman with secondary amenorrhea and primary sterility. INTERVENTION(S): Nucleotide sequencing of the P45017alpha gene (CYP17), induction of endometrial maturation with steroid hormone replacement, and ovulation induction with gonadotropin. MAIN OUTCOME MEASURE(S): Nucleotide sequence of CYP17, endometrial thickness and follicle diameter measured by transvaginal ultrasonography, and histologic evaluation of the endometrium. RESULT(S): Two different mutations were detected on CYP17: One was a deletion of the phenylalanine codon (TTC) at either amino acid 53 or 54 in exon 1, and the other was a missense mutation with the substitution of histidine (CAC) by leucine (CTC) at position 373 in exon 6. Repeated histologic evaluations performed during treatment with P consistently revealed an unripe endometrium with glands of the early secretory phase and markedly scanty stroma. Ultrasound examination revealed follicular growth and ovulation after gonadotropin administration, but insufficient thickness of the endometrium. CONCLUSION(S): Ovulation induction was possible in this patient with 17alpha-hydroxylase/17,20-lyase deficiency, but the endometrial response to steroid hormone replacement was extremely poor.

Adrenal Hyperplasia, Congenital↗

PubMed2000

Characterization of messenger RNA expression of estrogen receptor-alpha and -beta in patients with ovarian endometriosis.

OBJECTIVE: To evaluate the expression of estrogen receptor (ER)-alpha and ER-beta messenger RNA (mRNA) in ovarian endometriosis. DESIGN: Prospective study. SETTING: University hospital. PATIENT(S): Patients with endometriosis and patients with uterine leiomyoma or carcinoma in situ. INTERVENTION(S): A sample of ovarian endometriotic cyst tissue was obtained from each of the 32 patients during laparoscopic cystectomy. Samples of ovarian tissue and endometrium were obtained from 15 patients during or just after surgery. MAIN OUTCOME MEASURE(S): Expression of mRNA for ER-alpha and ER-beta with use of the reverse transcription-polymerase chain reaction (RT-PCR) and nonradioactive in situ hybridization (ISH) techniques. RESULT(S): Expression of mRNA for ER-alpha and ER-beta was observed in all of the control tissues from the normal endometrium and normal ovaries in the RT-PCR and ISH analyses, although the distribution of positive signals changed in the ISH analysis during different phases of the menstrual cycle. Messenger RNA for ER-alpha was detected in all of the ovarian endometriotic cysts analyzed (19 of 19), but mRNA for the ER-beta was limited (12 of 19) in the RT-PCR analysis. The ISH analysis confirmed the RT-PCR results and revealed that the two estrogen receptors were localized in both epithelial and stromal cells of endometriotic tissues. CONCLUSION(S): The results suggest that predominant expression of ER-alpha in both glandular epithelial and stromal cells may be essential to the development and growth of ovarian endometriosis.

Adult↗

PubMed2000

Quantitative analysis of estrogen receptor alpha and beta messenger ribonucleic acid levels in normal endometrium and ovarian endometriotic cysts using a real-time reverse transcription-polymerase chain reaction assay.

OBJECTIVE: To quantify messenger RNA (mRNA) levels of the two estrogen receptor isoforms, estrogen receptor-alpha (ER-alpha) and estrogen receptor-beta (ER-beta) in the eutopic endometrium and ovarian endometriotic cysts. DESIGN: Prospective study. SETTING: University hospital. PATIENT(S): Patients with endometriosis and patients with uterine leiomyoma or carcinoma in situ. INTERVENTION(S): Gonadotropin-releasing hormone agonist (GnRH-a)-treated (n = 12) or untreated (n = 24) endometriotic cysts were obtained from 36 patients during laparoscopic cystectomy. Eutopic endometrium tissues were obtained from 24 patients during or immediately after surgery. MAIN OUTCOME MEASURE(S): ER-alpha and ER-beta mRNA levels, using a real-time reverse transcription (RT)-polymerase chain reaction (PCR) assay, TaqMan RT-PCR. RESULT(S): Eutopic endometrium and ovarian endometriotic cysts showed predominantly higher levels of ER-alpha mRNA than ER-beta mRNA. Although ER-alpha and ER-beta mRNA levels in the eutopic endometrium were affected by a cyclic change in ovarian hormones, ovarian endometriotic cysts were less affected. Moreover, a long-term hypoestrogenic state induced by GnRH-a especially decreased ER-alpha mRNA levels in endometriotic cysts. Consequently, the relative ratios of ER-alpha to ER-beta mRNA levels in both GnRH-a-treated and untreated endometriotic cysts were significantly lower than those in the eutopic endometrium. CONCLUSION(S): The results suggest that the principal and regulatory effects of estrogens may be mediated mainly via ER-alpha rather than ER-beta in both the eutopic endometrium and endometriotic cysts.

Adult↗

PubMed2000

Growth pattern of twins of different chorionicity evaluated by sonographic biometry.

OBJECTIVE: To determine differences between growth patterns of monochorionic and dichorionic twins, and of concordant and discordant twins of both chorionicities. METHODS: We studied 70 cases of concordant twins (24 monochorionic, 46 dichorionic) and 45 cases of discordant twins (25 monochorionic, 20 dichorionic). In each case, growth was measured longitudinally by ultrasound biometry and the growth pattern was depicted. RESULTS: There were no differences in incremental growth between concordant monochorionic and dichorionic twins. The growth curve of concordant twins of both chorionicities was almost the same as that of a singleton until 34 weeks' gestation. However, in the discordant twins, the growth of the larger twin matched the growth curve of a singleton or concordant twin, but the growth of the smaller twin gradually decreased to the range of growth restriction. The growth curves for monochorionic discordant twins appeared to be representative of two groups, one of which had onset of discordancy before 24 weeks. CONCLUSION: It is clinically important to determine chorionicity early in twin pregnancies, to calculate the percentage of discordancy between the fetuses, and to examine longitudinal fetal growth curves in each chorionicity.

Biometry↗

PubMed2000

A new, simple method of making a spacer in interstitial brachytherapy for mobile tongue cancer.

OBJECTIVES: This article demonstrates a new method of making a spacer that increases the distance between the mandible and implanted radioactive sources in interstitial brachytherapy for patients with mobile tongue cancer. STUDY DESIGN: Fifty-three patients with mobile tongue cancer underwent interstitial brachytherapy with spacers made by this new technique. RESULTS: Our spacer is not difficult to create or to use. The spacer was made from a plastic splint by using thermoforming techniques and quick self-curing resin, which did not need waxing, wiring, or casting. The surface of the spacer, which comes in contact with the tongue, is smooth because it is covered with tissue-conditioning material. There were no complaints of pain from the patients. Osteoradionecrosis of the mandible developed in only 1 (1.9%) of these patients. CONCLUSIONS: This spacer is simple to make and prevented osteoradionecrosis.

Brachytherapy↗

PubMed2000

Power spectral analysis of R-R interval variability before and during the sinusoidal heart rate pattern in fetal lambs.

OBJECTIVE: The appearance of the sinusoidal heart rate pattern found on fetal cardiotocograms has not been fully explained, either physiologically or clinically. In this study we performed power spectral analysis on the sinusoidal heart rate pattern obtained by administration of arginine vasopressin and atropine sulfate to investigate its frequency components in fetal lambs with long-term instrument implantation. STUDY DESIGN: Eleven tests were performed in 4 fetal lambs at 120 to 130 days' gestation. An artificial sinusoidal heart rate pattern was obtained by administration of atropine sulfate and arginine vasopressin in 9 tests. An autoregression model was used to compare the spectral patterns before and during the sinusoidal heart rate pattern. RESULTS: Marked decreases in low-frequency (0.025-0.125 cycles/beat) and high-frequency (0.2-0.5 cycles/beat) areas were observed in the presence of the sinusoidal heart rate pattern. However, there were no significant changes in the very-low-frequency area (0.01-0.025 cycles/beat), which corresponds to the frequency of the sinusoidal heart rate pattern. CONCLUSION: The sinusoidal heart rate pattern may represent a very low-frequency component inherent in fetal heart rate variability that appears when low- and high-frequency components are reduced as a result of strongly suppressed autonomic nervous activity.

Animals↗

PubMed2000

Marked reduction of mortality in salt-loaded Dahl salt-sensitive rats by the new, selective endothelin ETA receptor antagonist, J-105859.

OBJECTIVE: To examine the chronic effects of a newly synthesized, potent and selective endothelin (ET) ETA receptor antagonist, J-1 05859, on mortality in salt-loaded Dahl salt-sensitive (DS) rats and to confirm the potential of this compound as an ETA antagonist METHODS: Vehicle and J-105859 were administered to salt-loaded DS rats for 12 weeks. Throughout the experimental period, blood pressure was measured continuously using a telemetry system and the survival rate was determined. The surviving animals were subsequently sacrificed and autopsy was performed. Binding and functional assays were also carried out to characterize J-1 05859. RESULTS: The Ki values of J-1 05859 for cloned human ETA and ETB were 0.025 and 48 nmol/l, respectively. J-105859 inhibited ET-1-induced contractions in rabbit iliac artery (pA2 = 10.08) and BQ-3020 (ETB agonist)-induced contractions in pulmonary artery (pA2 = 7.63). The pressor response to intravenous (i.v.) ET-1 (0.5 nmol/kg) was significantly inhibited by J-1 05859 at a dose of 0.03 mg/kg i.v. Chronic treatment with J-1 05859 [0.1 and 1 mg/kg per day orally (p.o.)] from the prehypertensive stage decreased the mortality of salt-loaded DS rats and markedly inhibited the development of brain lesions. The survival rates in the control and J-1 05859 (0.1 and 1 mg/kg per day) groups were 34, 80 and 100%, respectively. Development of hypertension was markedly inhibited at a dose of 1 mg/kg per day. CONCLUSION: J-105859 is a selective, potent, orally active ETA-selective antagonist ETA antagonists may reduce morbidity as well as mortality in salt-sensitive hypertension.

Alkanes↗

PubMed2000

Association of intrauterine growth retardation with monosomy of the terminal segment of the short arm of the X chromosome in patients with Turner's syndrome.

Short stature, which may be a result of intrauterine growth retardation (IUGR), is a characteristic of Turner's syndrome. However, the loci responsible for IUGR have not been well studied. We reviewed the birth records of 74 patients with Turner's syndrome: 20 with pure X monosomy, 44 with X-mosaicisms, and 10 with X-structural abnormalities. The overall incidence of IUGR was 39.2% (29 of 74 patients). The SHOX gene is encoded in a terminal segment of the short arm of the X chromosome. In 39 patients where two copies of the SHOX gene were absent, the incidence of IUGR was 46.2% (18 of 39 patients). In 14 patients with two copies of the SHOX gene, the incidence of IUGR was significantly lower at 7.1% (1 of 14 patients). Our results suggest that SHOX influences in utero growth in Turner's syndrome.

Comorbidity↗

PubMed2000

Compound heterozygous mutations (PHE53/54DEL and HIS373LEU) of the P450c17 gene result in a 17alpha-hydroxylase/17,20-lyase deficient male pseudohermaphrodite with unambiguous external genitalia.

The autosomal recessive disease 17alpha-hydroxylase/17,20-lyase deficiency is characterized by mutation of the P450c17 enzyme, which catalyzes 17alpha-hydroxylation and 17,20-lysis in the steroidogenic pathways. Although 17 mutations of this enzyme have been reported, only a few of them resulted in a completely unambiguous phenotype of female external genitalia in 46, XY individuals. We report here a Japanese patient with a 46,XY karyotype, who showed such a unambiguous female external genitalia. Nucleotide sequencing of the P450c17 gene revealed the patient to be a compound heterozygote carrying two different mutations (PHE53/54DEL in exon 1 and HIS373LEU in exon 6). As these mutations have been previously detected in unrelated Japanese patients, it is confirmed that these mutations accumulate regionally. Since these mutations could be screened by a multiple genotyping method, the method is applicable when 17alpha-hydroxylase/17, 20-lyase deficiency is suspected in Japanese patients.

Adrenal Hyperplasia, Congenital↗