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Biomedical subjects

S Matsubara

Publications and source records attributed to S Matsubara.

At least 433 records · Page 24Linked to original sources
PubMedDate not supplied

Dynamic MRI of transcorneal dispersion of oxygen into the anterior chamber of human eye.

To measure the transcorneal dispersion of oxygen into the anterior chamber, dynamic T1-weighted fast-spin-echo MRI (TR=2 seconds, TE=15 msec, 5-mm slice) of the human eye was performed both before and during oxygen supply to a full goggle placed on the face. During the course of the imaging, a significant increase in the signals in the anterior chamber occurred. This indicated that transcorneal dispersion of oxygen into the anterior chamber can be evaluated by this procedure, suggesting that this method may be useful for diagnosing dysfunction of the cornea or aqueous flow.

Analysis of Variance↗
PubMedDate not supplied

High dose rate intracavitary brachytherapy for recurrent or residual lesions in the vaginal cuff: results in post-hysterectomy patients with carcinoma of the cervix.

The purpose of this study was to assess the long-term survival, disease control, and complication rates of high dose rate intracavitary brachytherapy (HDR-ICR) alone or combined with external beam irradiation (HDR-ICR + EBRT) in patients with pathologically involved or close surgical margin in the vagina (Group 1) and recurrent lesions in the vaginal cuff (Group 2) following hysterectomy for cervical carcinoma. In Group 1, 10 patients received HDR-ICR only, and 11 patients received HDR-ICR + EBRT with or without paravaginal shielding. In Group 2, 8 patients received HDR-ICR only, and 11 patients received HDR-ICR + EBRT with or without paravaginal shielding. The HDR-ICR dose per fraction planned at the Apical Vaginal Point was 5-6 Gy per week. In Group 1, the 5-year absolute survival rates (AS), disease-free survival rates (DFS), and vaginal control rates (VC) were 81.0%, 76.2%, and 100%, respectively. The 5-year AS was lower in patients with parametrial infiltration or adenocarcinoma. In Group 2, the 5-year AS, DFS, and VC were 73.3%, 77.4% and 88.8%, respectively. The 5-year AS was lower when tumors were larger than 3 cm or infiltrated. Late complications occurred in 10 patients. In all but one patient, the complications were acceptable. All patients with cystitis, ileus, or leg edema received EBRT + HDR-ICR. We recommend a treatment regimen of 25-30 Gy of HDR-ICR alone for Group 1 patients without pathologically high risk of recurrence or Group 2 patients with superficial recurrent lesions, and a treatment regime of 50 Gy whole pelvis EBRT combined with 10-15 Gy HDR-ICR for Group 1 patients with pathologically high risk of recurrence or Group 2 patients with infiltrated recurrent lesions.

Adult↗
PubMedDate not supplied

Polymorphonuclear leukocytes in the fetal membranes are activated in patients with preterm delivery: ultrastructural and enzyme-histochemical evidence.

The purpose of this study was to examine evidence for the presence of activated leukocytes in the fetal membranes from patients with preterm delivery. Polymorphonuclear leukocytes in fetal membranes from seven patients with preterm delivery (26-32 weeks of gestation) were analysed using transmission electron microscopy and ultrastructural enzyme-histochemistry for peroxidase and alkaline phosphatase. A large number of leukocytes accumulated in the fetal membranes from preterm deliveries. Phagosome, phagocytosis of cell debris, attachment of primary granules to the phagosomal membrane and cell surface projections were observed in fetal membrane leukocytes from preterm delivery but not in peripheral blood leukocytes. Peroxidase and alkaline phosphatase activity was demonstrated on the plasma membrane of the phagosomes. Morphological and enzyme-histochemical observation indicated that polymorphonuclear leukocytes in the fetal membrane in patients with preterm delivery were stimulated or activated. Such activated leukocytes may play a role in the pathophysiology or pathogenesis of preterm delivery.

Alkaline Phosphatase↗
PubMedDate not supplied

Phagocytosis of chorion laeve trophoblasts in patients with chorioamnionitis-associated preterm delivery: ultrastructural and enzyme-histochemical observations.

The purpose of the present study was to examine morphological evidence for the presence of phagocytosing chorion laeve trophoblasts in fetal membranes from patients who had undergone chorioamnionitis-related preterm delivery. Chorion laeve trophoblasts from six patients, who underwent preterm delivery (28-34 weeks of gestation) complicated with chorioamnionitis, were analysed using transmission electron microscopy and ultrastructural enzyme-histochemistry for acid phosphatase, and compared with those from gestational age-matched chorioamnionitis-negative controls. Cytosomal cell projections, phagosomes, phagocytosis of degenerated cells and cell debris, attachment or fusion of lysosomes to the phagosomal membranes and phagosomal membranes positive for acid phosphatase staining were characteristically observed much more frequently in trophoblasts with chorioamnionitis than those without. The results indicated that chorion laeve trophoblasts in fetal membranes from patients having undergone chorioamnionitis-related preterm delivery underwent phagocytosis. Such phagocytosing trophoblasts may play a role in the pathophysiology or pathogenesis of infection-related preterm delivery.

Acid Phosphatase↗
PubMedDate not supplied

Placenta of idiopathic fetal growth restriction: cytochemically detectable enzyme activities do not change at a subcellular level.

The present study was designed to localize some important enzymes, such as adenosine diphospate-degrading enzyme (ADP-degrading enzyme) (plasma membrane enzyme), cytochrome c oxidase (mitochondrial enzyme) and glucose-6-phosphatase (endoplasmic reticulum enzyme), in placentae from patients with idiopathic fetal growth restriction (FGR) associated with absent end-diastolic flow velocity in the fetal umbilical artery. We compared these enzyme activities and their localization patterns to those in placentae both from pre-eclampsia with FGR and normal pregnancy with appropriate for their gestational age infants. In idiopathic FGR placentae, the intensity and localization patterns of these three enzymes did not differ from those seen in the placentae from normal pregnancy. Decreased ADP-degrading enzyme activity and cytochrome c oxidase negative mitochondria, which were characteristic features of pre-eclamptic trophoblasts, were absent from trophoblasts of the idiopathic FGR placentae. These observations indicated that enzyme-cytochemically detectable trophoblastic cell dysfunction may be absent in idiopathic FGR, or if present, there is less functional impairment of each trophoblast in this disease than in pre-eclampsia. Though both idiopathic FGR and pre-eclampsia lead to placental insufficiency, and finally to restricted fetal growth, a different mechanism and pathophysiology may work at the cellular and subcellular levels in these two diseases.

Adenosine Diphosphate↗
PubMedDate not supplied

Immuno-electron microscopic localization of endothelial nitric oxide synthase in human placental terminal villous trophoblasts-normal and pre-eclamptic pregnancy.

We demonstrated the subcellular localization of endothelial nitric oxide synthase (eNOS) in human placental terminal villous trophoblasts at near term period, and compared the distribution pattern with that in pre-eclamptic trophoblasts, using immunogold electron microscopy. Immunolabelling for eNOS was visible markedly in the syncytial microvilli and syncytial cytoplasm. Semiquantitative analysis showed that the concentration and the distribution pattern of gold particles for eNOS did not significantly differ between normal and pre-eclamptic placental trophoblasts. These results indicated that syncytiotrophoblastic microvilli and cytoplasm were the subcellular localization sites of syncytium-derived eNOS in terminal villi, and that there were no significant differences in this eNOS subcellular distribution pattern between normal and pre-eclamptic syncytiotrophoblasts in regard to immunohistochemically detectable eNOS.

Cytoplasm↗
PubMedDate not supplied

MR angiography of renal vascular malformations.

OBJECTIVE: We wanted to determine whether three-dimensional phase contrast (3DPC) MR angiography is clinically useful in the diagnosis of renal vascular malformations. MATERIALS AND METHODS: Three-dimensional PC MR angiography was performed in 22 patients with gross hematuria and in 8 healthy volunteers. Small flip angles and 60 cm/s velocity encoding best demonstrated the normal intrarenal arteries with arteriovenous differentiation in the eight healthy volunteers. In the 22 patients with gross hematuria, intraarterial digital subtraction angiography demonstrated cirsoid-type malformations in 6 patients, aneurysmal-type malformations in 3 patients, and normal vascular anatomy in 13 patients. RESULTS: Magnetic resonance angiography detected all three aneurysmal-type malformations and four of the cirsoid-type malformations. Small cirsoid-type malformations were not detected in two patients. The moderate or large malformations were demonstrated as dilated and tortuous feeding arteries and high intensity renal veins with high flow velocity. We found no correlation between signal intensity in the suprarenal inferior vena cava and the presence of arteriovenous shunts. There were no false-positive cases. CONCLUSION: Sensitivity, specificity, and accuracy in this series were 78, 100, and 91%, respectively.

Adolescent↗
PubMedDate not supplied

MRI of the TMJ disc with intravenous administration of gadopentetate dimeglumine.

PURPOSE: The purpose of this study was to ascertain whether MR imaging with intravenous administration of gadopenetate dimeglumine (Gd-DTPA) is useful in the demonstration of the temporomandibular joint (TMJ) disc. METHOD: Sagittal T1-weighted MR images of 50 TMJs (25 patients) were obtained using a 0.5-T system both before and after intravenous injection of Gd-DTPA. The authors depicted the TMJ in which intravenous injection of Gd-DTPA improved visulization of the disc. RESULTS: Intravenous injection of Gd-DTPA increased intensity in the retrodiscal space, the pterygoid venous plexus, as well as joint effusion by diffused Gd-DTPA. The technique improved visualization of 10 (50%) of 20 normal discs and 20 (67%) of 30 anterior disc displacements in closed-mouth position, and also 23 (74%) of 31 normal discs and 12 (63%) of 19 anterior disc displacements in open-mouth position. There were 12 TMJs (24% of the 50 TMJs) in which equivocal findings became highly diagnostic. The incidence in marked contrast effect was higher in TMJs with severe internal derangement than in those with normal or mild internal derangement (p < 0.005). CONCLUSION: Using a 0.5-T MR imager, T1-weighted imaging with intravenous injection of Gd-DTPA showed more anatomic details than imaging without the contrast agent.

Adolescent↗
PubMedDate not supplied

MR appearance of adenomatoid tumor of the uterus.

Reports on the radiological findings of adenomatoid tumor of the uterus are rare, and preoperative diagnosis is very difficult. To our knowledge, there have been no reports concerning the MR findings of adenomatoid tumor of the uterus. We report two cases of uterine adenomatoid tumor that showed the characteristic features of leiomyoma on MR images.

Adenomatoid Tumor↗
PubMedDate not supplied

Cellular signaling mechanisms for stimulation of growth hormone secretion and growth hormone primary transcripts by immunosuppressant agents, FK506 and cyclosporin A, in cultured rat pituitary cells.

Although an immunosuppressant, FK506, has been known to stimulate growth hormone (GH) release from rat somatotropes, the cellular signaling mechanism is unknown. In the present study, intracellular signaling pathways were investigated for FK506- and cyclosporin A (CsA)-induced GH release in cultured rat anterior pituitary cells. Northern and Western blot analysis revealed that the FK506-binding protein (FKBP12) and the CsA-binding protein (cyclophilin A) exist at the mRNA and protein level in the rat anterior pituitary tissue. FK506 and CsA increased GH release in a dose-dependent manner and inhibited calcineurin (CaN) activity in the cultured pituitary cells. The third immunosuppressant, rapamycin (RP), inhibited the FK506-induced GH release, although RP alone had no effect. Protein kinase A (PKA) inhibitors, H-89 and HA-1004 and EGTA blocked FK506- and CsA-induced GH release. TGF-beta did not alter basal GH release, but inhibited FK506-induced GH release. GH primary transcripts were increased by FK506, and the effects were blocked by H-89 and HA-1004. These results suggest that the immunosuppressants, FK506 and CsA, stimulate GH release by inhibiting CaN activity which results in the activation of the PKA system in the rat somatotropes. TGF-beta receptors might be involved in FK506-induced GH release as a separate pathway. FK506 also stimulates GH primary transcripts via a PKA-dependent mechanism in a manner similar to its effects on GH release.

Animals↗
PubMedDate not supplied

Umbilical cord pseudocyst in a fetus with trisomy 18.

An umbilical cord pseudocyst was detected in the 28th week of gestation in a fetus complicated with growth restriction and polyhydramnios. The combination of cord pseudocysts, growth restriction, and polyhydramnios prompted us to perform a detailed ultrasonographic examination (gray scale and three-dimensional), which revealed the presence of micrognathia, overlapping fingers, and congenital heart defects, features characteristic of trisomy 18. Karyotyping confirmed a diagnosis of trisomy 18. After spontaneous labor onset, the infant was delivered at 31 weeks of gestation, and died soon after delivery. An umbilical cord pseudocyst is a good marker for the prenatal detection of trisomy 18.

Adult↗
PubMedDate not supplied

Combined effects of ultrasound and ionizing radiation on lymphocyte chromosomes.

The effects of ionizing radiation and ultrasound upon the induction of chromosomal-type aberrations and sister chromatid exchanges were investigated. No statistically significant increase in the frequencies of dicentric and ring chromosomes or sister chromatid exchanges was discovered after ultrasound exposure alone at the diagnostic level. Nor could elevated frequencies of these phenomena be found following exposure to ultrasound before or after ionizing radiation, compared with those resulting from an equivalent dose of ionizing radiation alone. However, simultaneous exposure to ultrasound and ionizing radiation seemed to induce a slight enhancement of sister chromatid exchanges, although no significant change was noted in the yields of dicentric and ring chromosomes.

Abnormalities, Radiation-Induced↗
PubMedDate not supplied

Polyadenylation signal facilitates the expression of foreign gene that is driven by an internal promoter located in the reverse orientation to long terminal repeat of retrovirus.

We examined whether the presence of a polyadenylation [poly(A)] signal in a retrovirus vector could affect the expression level of exogenous gene(s) that was controlled by an internal promoter. Three suicide genes were placed under a promoter of the human midkine gene, whose expression is elevated in lung cancer cells. Orientation of the internal transcriptional unit was designed to be opposite to the viral long terminal repeat. Expression of each suicide gene was greater in ecotropic packaging cells transfected with a retrovirus vector without a poly(A) signal than in those with a poly(A)-containing vector. Sensitivity to ganciclovir, a prodrug that becomes an active drug by herpes simplex virus-thymidine kinase, was significantly improved in retrovirally transduced lung cancer cells compared with wild-type cells. However, the sensitivity was much greater in the cells transduced with poly(A)-containing vector than in those with poly(A)-deleted construct. The presence of a poly(A) signal downstream of exogenous gene(s) therefore favors the expression of foreign gene(s) driven by an internal promoter.

Biotransformation↗
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The expression of cadherins in human neuroblastoma cell lines and clinical tumors.

Cadherins are Ca(2+)-dependent cell-cell adhesion molecules which play crucial roles in the cell-cell interactions during development, tumorigenesis and metastasis. The absence of N (neural)-cadherin is correlated with the onset of neural crest migration and its reappearance is correlated with the cessation of migration and precedes gangliogenesis. We investigated the expression of cadherins including N-cadherin in five cell lines and eleven clinical specimens of human neuroblastomas, which originated from neural crest cells. We found that three of the neuroblastoma cell lines and all the clinical specimens were positive for the expression of the N-cadherin protein. The other two neuroblastoma cell lines were negative for the expression suggesting they originated from migrating neural crest cells. All these cell lines and clinical samples expressed either cadherin-6, cadherin-11 or both, i.e. cadherins expressed on neural crest cells, supporting their neural crest origin.

Adolescent↗
PubMedDate not supplied

Angiographic and clinical characteristics of patients with cerebral arteriovenous malformations associated with hereditary hemorrhagic telangiectasia.

BACKGROUND AND PURPOSE: Cerebral arteriovenous malformations (AVMs) are occasionally associated with hereditary hemorrhagic telangiectasia (HHT), which is characterized by the presence of multiple mucocutaneous telangiectasia, epistaxis, and familial inheritance. We analyzed the angiographic and clinical characteristics of patients with cerebral AVMs related to HHT. METHODS: Among 638 patients with cerebral AVMs, we identified 14 patients with HHT. The AVMs were classified as those with nidi of 1 cm or less (micro AVMs), those with nidi between 1 and 3 cm (small AVMs), and those of the fistulous type (arteriovenous fistulas [AVFs]). RESULTS: A total of 28 AVMs were found; seven of 14 patients had multiple AVMs. The 28 AVMs were categorized as 12 micro AVMs, eight small AVMs, and eight AVFs. All except one micro AVM were asymptomatic, whereas all small AVMs were symptomatic. Three of eight AVFs were asymptomatic. All 28 AVMs were located on the cortex. All micro AVMs and AVFs had single feeders and single draining veins, whereas the small AVMs had multiple feeders in all lesions and single draining veins in six of eight lesions. CONCLUSION: Multiple, cortical, micro AVMs or AVFs harboring single feeding arteries and single draining veins should raise clinical suspicion of HHT-related AVMs.

Adolescent↗
PubMedDate not supplied

Morphometric study of nucleus ambiguus in multiple system atrophy presenting with vocal cord abductor paralysis.

AIM: To identify lesions responsible for vocal cord abductor paralysis (VCAP) in multiple system atrophy (MSA), we performed a morphometric study of the nucleus ambiguus which innervates the intrinsic laryngeal muscles. METHODS: Two autopsied cases of MSA presenting with VCAP and one control were examined. Both cases of MSA showed selective neurogenic atrophy of the posterior cricoarytenoid muscles among the intrinsic laryngeal muscles, while no abnormalities were seen in the control. From a block of the medulla oblongata, sections 10 microm thickness were cut serially without spacing and stained with cresyl violet. The ambiguus neurons were counted in all the sections to make a histogram. RESULTS: In the control case, ambiguus neurons showed densely populated areas and sparsely populated areas alternately with significant difference in the mean neuronal density between two areas. In MSA, ambiguus neurons were significantly decreased in number at all levels. It indicates that the neurogenic atrophy of the posterior cricoarytenoid muscle is derived from the neuronal loss of the nucleus ambiguus. CONCLUSION: Though it has still been controversial whether or not the ambiguus neurons are decreased in number in MSA with VCAP, we speculated possible reasons for the disagreement on the involvement of the nucleus ambiguus as follows: different mechanism of VCAP are playing role, and histometric data have been disturbed by factors such as split-cell counting error and marked variation in the distribution of the ambiguus neurons.

Adult↗
PubMedDate not supplied

Effects of supplementary parenteral nutrition on thyroid hormone patterns in surgical patients with liver cirrhosis.

The relationship between nutritional intervention and circulating thyroid hormones and rapid-turnover proteins was investigated in surgical patients with liver cirrhosis. Fourteen patients with well-compensated liver cirrhosis who were subjected to operations for esophageal varices or hepatoma were divided into two groups. The oral group was offered an oral diet containing 2200 kcal/day before surgery and conventional intravenous infusions of 5% glucose after the operation (500-600 kcal/day). The supplementary parenteral nutrition (SPN) group was offered the same oral diet as the oral group, combined with intravenous 50% glucose, fat emulsion, and branched-chain enriched amino acid solution, 600-1000 kcal and 7.32 g nitrogen/day during the 10 days before surgery and 800-1800 kcal and 7.32-9.76 g nitrogen/day during the first 2 wk postoperative. Plasma triiodothyronine (T3) was higher in the SPN group (1.26 +/- 0.09 ng/ml) than in the oral group (0.91 +/- 0.08 ng/ml) (P less than 0.001), and reverse T3 (rT3) was lower in the SPN group (297 +/- 33 pg/ml) than in the oral group (351 +/- 29 pg/ml (P less than 0.01) on the day of surgery. In addition, SPN significantly attenuated the low T3 and high rT3 levels found in the oral group throughout the 2 postoperative wk. In addition, attenuation of decreases in rapid-turnover proteins was achieved in the SPN group. It is likely that the SPN contributed to the partial correction of liver dysfunction and metabolic imbalance in traumatized cirrhotic patients.

Adult↗