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Biomedical subjects

H Ito

Publications and source records attributed to H Ito.

At least 523 records · Page 29Linked to original sources
PubMed1999

Rathke's cleft cyst with pituitary apoplexy: case report.

We report a Rathke's cleft cyst which presented as pituitary apoplexy, a rare presentation. A 46-year-old woman suffered sudden headache and visual loss. T1-weighted MRI 3 weeks after this apoplectic episode demonstrated a cystic lesion between the anterior and posterior lobes of the pituitary, with some high-signal material layering in it. The mass showed spontaneous regression on an image 3 weeks later. Trans-sphenoidal surgery confirmed the diagnosis of a Rathke's cleft cyst with a haematoma within it.

Blindness↗
PubMed1999

Cephaloceles and abnormal venous drainage.

Seven cases of parietal cephalocele and three cases of occipital cephalocele associated with abnormal venous drainage were evaluated, and the mechanism of the development for venous system was discussed from the embryological viewpoint. In parietal cephaloceles the abnormally draining vein, which corresponds to the straight sinus, ascended along the interhemisphere apart from the tentorium and emptied into the superior sagittal sinus below the cephalocele. The superior sagittal sinus formed the confluence, which was positioned high up. Intraoperative findings revealed that cephalocele penetrated the superior sagittal sinus at the midline. In the case of occipital cephalocele, the straight sinus followed a postero-superior course, to drain into the confluence just above the neck of cephalocele. The results of our study suggest that the causation of abnormal venous drainage in the great vein of Galen, the straight sinus and the superior sagittal sinus may be secondary, through interaction with a developmentally pre-existing cephalocele.

Brain↗
PubMed1999

T cell malignant lymphoma in the central nervous system after acute lymphoblastic leukemia in a child.

A malignant lymphoma developed in the central nervous system (CNS) of a 7-year-old boy 5 years after he had received chemotherapy and cranial irradiation for acute lymphoblastic leukemia (ALL). Bone marrow analysis of the original leukemia showed a pre-B cell phenotype, whereas the resected brain tumor showed a T cell phenotype on immunophenotypic analysis. Because of this difference in immunophenotype, and because the patient had received multiple-drug chemotherapy and 1,800 cGy of cranial irradiation for the original ALL, we consider that the malignant lymphoma was a second neoplasm. This is a very rare case in two respects: it was a malignant lymphoma arising in the CNS as a second neoplasm after ALL and a T cell lymphoma occurring in a child.

Brain Neoplasms↗
PubMed1999

Immunocytochemical demonstration of oncocytes in normal adenohypophysis.

Immunocytochemical examination for mitochondrial protein and cytochrome oxidase was performed to demonstrate oncocytes in normal adenohypophysis obtained from 28 patients of various age. A small number of solitary large epithelial cells showed intense cytoplasmic granular immunoreactivities for mitochondrial protein and cytochrome oxidase. The proportions of the cells positive for the former and the latter ranged from 0% to 5.9% (mean+/-SD; 1.5+/-1.7%) and from 0% to 4.9% (1.4+/-1.6%), respectively. These cells were either absent or extremely rare in young patients (under 10 years) but tended to increase in number with age (P < 0.0001). On the other hand, the mirror section technique showed that most of these cells were negative for adenohypophysial hormones, but a few of them were faintly positive for: alpha-subunit (8.0%), beta-subunits of follicle-stimulating hormone (4.8%), luteinizing hormone (2.5%), thyroid-stimulating hormone (1.0%), and growth hormone (0.5%), and were negative for prolactin and adrenocorticotropic hormone. We considered that these cells represent oncocytes that exist in varying numbers in normal adenohypophysis. It was suggested that oncocytes in normal adenohypophysis share various common features with tumorous oncocytes of pituitary oncocytomas.

Adolescent↗
PubMed1999

Immunohistochemical demonstration of oncocytes in nongonadotrophic pituitary adenomas.

An immunohistochemical study to demonstrate oncocytes in nongonadotrophic pituitary adenomas was performed. The adenomas were 10 prolactinomas, 2 ACTH-producing adenomas (ACTHomas), and 28 growth hormone-producing adenomas (GHomas); we also studied 5 pituitary oncocytomas. GHomas were divided into two groups: GHomas with (GHomas-1) and without (GHomas-2) fibrous bodies. A small number of solitary large cells showed intense cytoplasmic granular reactivity for mitochondrial protein and cytochrome oxidase, resembling oncocytes in oncocytomas. The proportions of the mitochondrial protein-positive cells ranged from zero to 2.1% (0. 3+/-0.4%). They were more frequent in GHomas, GHomas-1 in particular, than other types of adenomas (P<0.01), and were mostly negative in prolactinomas and ACTHomas. In multivariate analysis, the proportions showed positive correlation with age (P<0.01) and the Ki-67 (MIB-1) labeling index (P<0.01) and tended to increase in number with recurrence (P<0.05). In GHomas, these cells were more common in cases with low basal GH level (P<0.01) and large tumor volume (P<0.01). We consider that these cells represent oncocytes existing in varying numbers in adenomas. We suggest that oncocytic change in nongonadotrophic adenomas indicates poor differentiation and/or some aggressiveness, which lead to a decrease in the endocrine activity of the tumor.

Adenoma↗
PubMed1999

Synaptology and ultrastructural characteristics of laryngeal cricothyroid and posterior cricoarytenoid motoneurons in the nucleus ambiguus of the rat.

The laryngeal motoneurons innervating the cricothyroid muscle (CT) are located in the semicompact formation just ventral to the rostral part of the compact formation of the nucleus ambiguus. The motoneurons innervating the posterior cricoarytenoid muscle (PCA) are located in the loose formation. We retrogradely labeled the CT and the PCA motoneurons using cholera toxin subunit B-conjugated horseradish peroxidase, and determined the ultrastructure and synaptic organization of these neurons. The CT and the PCA motoneurons had the appearance of alpha-motoneurons, i.e., large, oval or polygonal cells containing well-developed organelles and a prominent spherical nucleus. Two kinds of neurons were recognized among the PCA motoneurons. The one (PCA-A) was significantly smaller than the other (PCA-B). The average number of axosomatic terminals in a section was significantly largest in the PCA-B (56.6), smaller in the PCA-A (36.0), and smallest in the CT (32.3) neurons. Most of the axosomatic terminals (64.7%) contained pleomorphic vesicles and made symmetric synaptic contacts (Gray's type II) with the PCA-A neurons, while more than 60% contained round vesicles with asymmetric synaptic contacts (Gray's type I) in the CT (69.5%) and the PCA-B (60.6%) neurons. A few terminals associated with subsurface cisterns were present on all laryngeal motoneurons. These results indicated that the CT motoneurons may receive mostly excitatory terminals, whereas the PCA muscle may be regulated by neurons having many inhibitory terminals, and neurons having many excitatory terminals.

Animals↗
PubMed1999

Percutaneous renal biopsy in children: survey of pediatric nephrologists in Japan.

Between 1996 and 1997, 2,045 percutaneous renal biopsies were performed on native kidneys in 2,013 patients in pediatric nephrology units in Japan. Of these, 50.8% were performed by automated needle biopsy gun under ultrasound guidance, and the standard biopsy needle, Tru-cut needle or Vim-Silverman needle, under fluoroscopic guidance was used in 12.4% and 12.3% of the biopsies, respectively. Adequate renal tissue for histological diagnosis was obtained in 98.7% of cases, and the success rates for the techniques were not significantly different. The overall complication rate was 5.8%; gross hematuria occurred in 2.7% and large perirenal hematoma in 0.9% of cases. These complication rates were higher when a standard needle under fluoroscopic guidance was used compared with an automated needle under ultrasound guidance. We conclude that pediatric nephrologists in Japan perform percutaneous renal biopsies safely, partly due to technical improvements, such as the automated needle or ultrasound guidance.

Adolescent↗
PubMed1999

Aggressive surgical resection for hepatic metastases involving the inferior vena cava.

BACKGROUND: The implications of aggressive surgical approaches for hepatic metastases involving the inferior vena cava (IVC) have not been clarified yet. The aim of this study is to assess the preliminary results of aggressive surgical resection for hepatic metastases involving the IVC. METHODS: Sixteen patients with hepatic metastases involving the IVC underwent surgical resections with the repair and reconstruction of the IVC: patch repair in 2 and ringed Goretex in 1, primary closure in 13 patients. Hepatic metastases were from colorectal cancer in 14, stomach cancer in 1, and uterine cancer in 1 patient. RESULTS: Vascular control utilized for resecting the IVC were total hepatic vascular exclusion in 8, hypothermic isolated hepatic perfusion in 3, and side clamp in 5 patients. The combined IVC resection with hepatectomy in 16 patients brought about 25% and 6% surgical morbidity and mortality rates, respectively. Survival rates following surgical resections were 64%, 33%, 33%, 22%, 22% for 14 patients of colorectal metastases involving the IVC as compared with 82%, 58%, 41%, 37%, 27% at 1, 2, 3, 4, 5 years, respectively, for 154 patients of colorectal metastases not involving the IVC. CONCLUSION: Hepatic metastases involving the IVC could be safely resected without an increase in surgical risk. Aggressive surgical approaches might bring about a favorable outcome in select patients with colorectal hepatic metastases involving the IVC.

Adult↗
PubMed1999

Changes in hepatic venous oxygen saturation related to the extent of regeneration after partial hepatectomy in rats.

BACKGROUND: Changes in hepatic oxygen metabolism in relation to the extent of liver regeneration are expected after partial hepatectomy. There are few reports, however, about hepatic oxygen metabolism during liver regeneration. In this study, we evaluated changes in hepatic oxygen metabolism related to the regeneration rate, and the relationship between hepatic venous oxygen saturation (Shvo2) and liver regeneration after partial hepatectomy. METHODS: The work was done using 50% hepatectomized rats with continuous infusion of octreotide for inhibition of liver regeneration or with saline as control. The hepatic hemodynamics, oxygen metabolism, and Shvo2 levels as well as the regenerating liver status were evaluated for 3 days after hepatectomy. RESULTS: Administration of octreotide resulted in a significant reduction of the regenerating liver weight on days 1 and 3 after hepatectomy compared with the control group. Significantly decreased DNA synthesis and proliferating cell nuclear antigen labeling index were also found on day 1. Meanwhile, hepatic oxygen consumption (HVO2) and oxygen extraction ratio were significantly decreased in the octreotide-treated group on day 1. In contrast, the Shvo2 levels in the octreotide-treated group were significantly higher than those in the control group, and were inversely correlated with the HVO2. CONCLUSION: The remnant liver demands an increased amount of oxygen in relation to the extent of regeneration, and changes in the Shvo2 are inversely correlated with the HVo2. Therefore, monitoring the Shvo2 could be useful for estimating liver regeneration after partial hepatectomy.

Animals↗
PubMed1999

Thermal preconditioning protects rat cardiac muscle cells from doxorubicin-induced apoptosis.

Doxorubicin (DOX=adriamycine), an effective chemotherapeutic agents for cancers, has severe cardiotoxicity. In the paresent study, we examined the protective effect of thermal preconditioning (TP) against apoptosis of rat cardiac muscle cells induced by DOX. Treatment with DOX (10 microM) for 24 hrs resulted in apoptosis of cardiac muscle cells, which was evaluated by examining "DNA ladder" formation and TUNEL staining. The number of TUNEL-positive cells was significantly decreased in cells subjected to TP by incubation at 42 degrees C for 30 min, 24 hrs prior to DOX-treatment. Antisense oligonucleotides of the heat shock protein (HSP) 70 blunted this effect. These results indicate that DOX-induced apoptosis in cardiac muscle cells is prevented by TP, at least in part, via a HSP70-mediated mechanism.

Animals↗
PubMed1999

Oligomeric hydrolysable tannins from Tibouchina multiflora.

Two hydrolysable tannins, nobotanin O and nobotanin P, were isolated from the leaf extract of Tibouchina multiflora (Melastomataceae) and their dimeric and tetrameric structures elucidated on the basis of spectral data and chemical correlations with nobotanin B and K, respectively. Thirteen known hydrolysable tannins including nobotanins A, B, C and J, which are oligomers characteristic of the Melastomataceae, were also isolated.

Carbohydrate Sequence↗
PubMed1999

Two processes in stereoscopic apparent motion.

This study investigated the human ability to discriminate the motion direction of sequentially presented depth patterns produced by random-dot stereograms. The stereoscopic (cyclopean) patterns used here consisted of 256 rectangle patches, each of which had an alternative depth position (near or far). Two successive frames of correlated depth patterns made impressions of lateral motion when the pattern position in the second frame shifted laterally. The density of the patches that were near was varied. The Dmax that was measured using the 2AFC method was short when the density was high. The effect of depth reversing in the second frame was also tested. Under low density conditions, the performance was still good against reversing 3-D polarity. However, when the density was high, with depth reversal, motion in the reversed direction was perceived. Reversed motion was observed more often when SOA was small and when the density of near patches was near 1/2. Two strategies seem to exist in stereoscopic motion detecting: a polarity-independent process which matches figures, ignoring their depth polarity, and a polarity-dependent process which operates locally, ignoring 2-D shapes. The latter suggests the existence of a passive process in stereoscopic motion.

Depth Perception↗
PubMed1999

Antimony in municipal waste.

Antimony content in municipal waste was studied. Sampled municipal waste was dried, crushed and analyzed. Antimony determinations were performed by Kjeldahl decomposition--batch hydride generation spectrometry and neutron activation analysis. Overall content of antimony in waste was 40-50 g/t raw waste. It was estimated than 20% of the annual production of antimony was discarded as municipal waste in Japan. Leaching of antimony from antimony-added materials may occur, because "small tips" involved considerable amounts of antimony.

Antimony↗
PubMed1999

Long-term results of a randomized trial for the treatment of Stages B2 and C prostate cancer: radical prostatectomy versus external beam radiation therapy with a common endocrine therapy in both modalities.

OBJECTIVES: To improve the treatment of locally advanced prostate cancer (Stages B2 and C), a prospective randomized trial was conducted to compare radical prostatectomy versus external beam radiotherapy with the combination of endocrine therapy in both modalities. METHODS: One hundred patients were enrolled and 95 were evaluated. Forty-six patients underwent radical prostatectomy with pelvic lymph node dissection, and 49 were treated with radiation by linear accelerator with 40 to 50 Gy to the whole pelvis and a 20-Gy boost to the prostatic area. For all patients, endocrine therapy was initiated 8 weeks before surgery or radiation, and continued thereafter. The living patients were asked to respond to a quality-of-life questionnaire. RESULTS: The follow-up period ranged from 6.0 to 94.4 months (median 58.5). The progression-free and cause-specific survival rates at 5 years were 90.5% and 96.6% in the surgery group and 81.2% and 84.6% in the radiation group, respectively. The surgery group had better progression-free and cause-specific survival rates (P = 0.044 and 0.024, respectively). More patients in the surgery group complained of urinary incontinence. The questionnaire revealed that quality of life was less disturbed in the radiation group. CONCLUSIONS: Radical prostatectomy combined with endocrine therapy may contribute to the survival benefit of patients with locally advanced prostate cancer. External beam radiotherapy in combination with endocrine therapy can be used in selected patients because of its low morbidity.

Adenocarcinoma↗
PubMed1999

Biosynthesis and characterization of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) produced by Burkholderia cepacia D1.

Copolyesters of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) were produced by Burkholderia cepacia D1 at 30 degrees C in nitrogen-free culture solutions containing n-butyric acid and/or n-valeric acid. When n-valeric acid was used as the sole carbon source, the 3HV fraction in copolyester increased from 36 to 90 mol% as the concentration of n-valeric acid in the culture solution increased from 1 to 20 g/l. The addition of n-butyric acid to the culture solution resulted in a decrease in the 3HV fraction in copolyester. The copolymers biosynthesized by this method were mixtures of random copolymers having a wide variety of composition of the 3HV component. The melting points of the fractionated copolymers show a concave curve with the minimum at the 3HV content of approximately 40 mol%. The alpha-parameter of lattice indices of the P(3HB) crystal for the fractionated copolymers largely increased as the 3HV composition increased. Biodegradability of the copolymer increased with the lower content of 3HV composition and/or the lower crystallinity.

Burkholderia cepacia↗