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Biomedical subjects

N Hata

Publications and source records attributed to N Hata.

At least 37 records · Page 2Linked to original sources
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

[Extracranial metastasis of glioblastoma to the lung and heart with a histological resemblance to small cell carcinoma of the lung: an autopsy case].

An autopsy case of small cell glioblastoma, showing multiple extracranial metastases, is reported with special reference to histopathological differentiation from metastatic small cell carcinoma. Widely spread lesions in the bilateral lungs were developed after an operation and chemo-radiotherapy for glioblastoma, and the lung lesions led to fatal respiratory failure. Postmortem examination revealed multiple tumors in the lung, lymph nodes, and the heart, as well as local invasion of the primary tumor to the dura, skull, and the scalp. The mechanism of extracranial metastasis of brain tumor is discussed.

Adult↗
PubMed2001

Reversibility of n-3 fatty acid deficiency-induced alterations of learning behavior in the rat: level of n-6 fatty acids as another critical factor.

Rats fed a semipurified diet supplemented with 3% (w/w) safflower oil [Saf, n-3 fatty acid deficient, high linoleic acid (18:2n-6)] through two generations exhibit decreased correct response ratios in a brightness-discrimination learning test compared with rats fed 3% perilla oil [Per, high alpha-linolenic acid (18:3n-3)]. This is associated with a decreased DHA (22:6n-3)-to-arachidonic acid (20:4n-6) ratio in brain lipids. In the first set of experiments, dietary oil was shifted from Saf to a mixture of 2.4% safflower oil plus 0.6% DHA after weaning (Saf-DHA), but all parameters measured in the learning test were essentially unchanged. Brain 22:6n-3 content of the Saf-DHA group reached that of the Per group but the levels of 20:4n-6 and docosatetraenoic acid (22:4n-6) did not decrease to those of the Per group at the start of the test. In the second set of experiments, dietary oil was shifted to a mixture of 0.6% safflower oil plus 1.2% oleic acid (OA) plus 1.2% DHA (Saf-OA-DHA group) with 18:2n-6 content comparable to that of the Per group. The Saf-OA-DHA group exhibited a learning performance similar to that of the Per group; brain 22:6n-3, 20:4n-6, and 22:4n-6 contents were also comparable to those of the Per group. These results indicate that the altered learning behavior associated with a long-term n-3 fatty acid deficiency is reversed by supplementing 22:6n-3 after weaning, when the levels of competing n-6 fatty acids in the diet and brain lipids are limited.

Aging↗
PubMed2001

Lack of antagonism between nicorandil and sulfonylurea in stable angina pectoris.

The aim of this study was to clarify whether or not nicorandil (a potassium channel opener) caused adverse reactions in patients with angina pectoris who also had diabetes mellitus treated with sulfonylurea (a potassium channel inhibitor). Nineteen diabetic patients with angina pectoris were enrolled, eight were treated with glibenclamide (group A) and 11 were not (group B). Treadmill exercise testing and frequency of anginal attacks were used to evaluate the severity of angina pectoris. Blood sugar and hemoglobin A1c were measured for evaluation of diabetes mellitus control. Exercise tolerance, frequency of anginal attacks and diabetes mellitus control were not perturbed by treatment in either group. In conclusion, there were no antagonistic reactions from the combination of nicorandil with sulfonylurea in angina pectoris complicated by diabetes mellitus.

Aged↗
PubMed2000

Dietary docosahexaenoic acid ameliorates, but rapeseed oil and safflower oil accelerate renal injury in stroke-prone spontaneously hypertensive rats as compared with soybean oil, which is associated with expression for renal transforming growth factor-beta, fibronectin and renin.

We have noted that n-3 fatty acid-rich oils, such as fish oil, perilla oil and flaxseed oil as well as ethyl docosahexaenoate (DHA) prolonged the survival time of stroke-prone spontaneously hypertensive rats (SHRSP) rats by approximately 10% as compared with linoleate (n-6)-rich safflower oil. Rapeseed oil with a relatively low n-6/n-3 ratio unusually shortened the survival time by approximately 40%, suggesting the presence of minor components unfavorable to SHRSP rats. This study examined the effects of dietary oils and DHA on renal injury and gene expression related to renal injury in SHRSP rats. Rats fed rapeseed oil- and safflower oil-supplemented diets developed more severe proteinuria than those fed soybean oil-supplemented diet used as a control, but there were no significant differences in blood pressure. In contrast, the DHA-supplemented diet inhibited the development of proteinuria and suppressed hypertension. The mRNA levels for renal TGF-beta, fibronectin and renin were higher in the rapeseed oil and safflower oil groups after 9 weeks of feeding of the experimental diet than in the soybean oil and DHA groups. The fatty acid composition of kidney phospholipids was markedly affected by these diets. These results indicate that the renal injury observed in the groups fed safflower oil with a high n-6/n-3 ratio and rapeseed oil with presumed minor components is accompanied by increased expression of the TGF-beta, renin and fibronectin genes, and that dietary DHA suppresses renal injury and gene expression as compared with soybean oil.

Animals↗
PubMed2000

Effect of n-3 fatty acid deficiency on fatty acid composition and metabolism of aminophospholipids in rat brain synaptosomes.

Docosahexaenoic acid (DHA, 22:6n-3) is one of the major polyunsaturated fatty acids esterified predominantly in aminophospholipids such as ethanolamine glycerophospholipid (EtnGpl) and serine glycerophospholipid (SerGpl) in the brain. Synaptosomes prepared from rats fed an n-3 fatty acid-deficient safflower oil (Saf) diet had significantly decreased 22:6n-3 content with a compensatory increased 22:5n-6 content when compared with rats fed an n-3 fatty acid-sufficient perilla oil (Per) diet. When the Saf group was shifted to a diet supplemented with safflower oil plus 22:6n-3 (Saf + DHA) after weaning, 22:6n-3 content was found to be restored to the level of the Per group. The uptake of [3H]ethanolamine and its conversion to [3H]EtnGpl did not differ significantly among the three dietary groups, whereas the formation of [3H]lysoEtnGpl from [3H]ethanolamine was significantly lower in the Saf group than in the other groups. The uptake of [3H]serine, its incorporation into [3H]SerGpl, and the conversion into [3H]EtnGpl by decarboxylation of [3H]SerGpl did not differ among the three dietary groups. The observed decrease in lysoEtnGpl formation associated with a reduction of 22:6n-3 content in rat brain synaptosomes by n-3 fatty acid deprivation may provide a clue to reveal biochemical bases for the dietary fatty acids-behavior link.

Animals↗
PubMed2000

Ultrasound biomicroscopic analysis of posterior chamber intraocular lenses with transscleral sulcus suture.

OBJECTIVE: To investigate the postoperative problems of intraocular lenses (IOLs) with transscleral sulcus suture. DESIGN: Retrospective observational case series. PARTICIPANTS: Forty-one subjects (43 eyes) were included. INTERVENTION: All eyes had undergone transscleral sulcus suture of IOLs. Surgeries were all performed by surgeons in our clinic using the same technique. MAIN OUTCOME MEASURES: Ultrasound biomicroscopy of the suture sites, their surrounding structures, and central anterior chamber depth. Other parameters studied included visual acuity, aqueous flare, and routine ophthalmic examinations. RESULTS: Thirty-two of 86 haptics were sutured at the ciliary sulcus (CS) region and 29 at the ciliary process region, which was the space between CS and pars plicata, and 25 posterior to pars plicata. We designated the cases with at least one haptic located in the CS region as the anterior group, and the other cases as the posterior group. In the anterior group, anterior chamber depth was significantly more shallow than in the fellow eye in which IOLs were fixed in the bag (P = 0.049). There was a statistically greater incidence of IOL iris contact in the anterior group than in the posterior group (P = 0.00057). Pigment dispersion was seen in seven cases, all of which were classified as anterior group. Eyes in the posterior group had more aqueous flare than their fellow eyes (P = 0.014). Two cases, in which more than two lines of postoperative best-corrected visual acuity was lost because of macular degeneration after cystoid macular edema, showed marked elevation of aqueous flare in the sutured eyes compared with their fellow eyes. Forty-one of 86 haptics had vitreous incarceration. CONCLUSIONS: This technique has many limitations: the difficulty of suturing precisely at the ciliary sulcus, IOL iris contact, pigment dispersion, high aqueous flare, and vitreous incarceration. These induce two major postoperative complications: chronic inflammation and influence on the adjacent vitreous such as vitreous incarceration. The suturing technique and instruments need to be improved to diminish such complications.

Aged↗
PubMed2000

Distinct and essential roles of transcription factors IRF-3 and IRF-7 in response to viruses for IFN-alpha/beta gene induction.

Induction of the interferon (IFN)-alpha/beta gene transcription in virus-infected cells is an event central to innate immunity. Mice lacking the transcription factor IRF-3 are more vulnerable to virus infection. In embryonic fibroblasts, virus-induced IFN-alpha/beta gene expression levels are reduced and the spectrum of the IFN-alpha mRNA subspecies altered. Furthermore, cells additionally defective in IRF-7 expression totally fail to induce these genes in response to infections by any of the virus types tested. In these cells, a normal profile of IFN-alpha/beta mRNA induction can be achieved by coexpressing both IRF-3 and IRF-7. These results demonstrate the essential and distinct roles of thetwo factors, which together ensure the transcriptional efficiency and diversity of IFN-alpha/beta genes for the antiviral response.

Animals↗
PubMed2000

Dietary docosahexaenoic acid but not eicosapentaenoic acid suppresses lipopolysaccharide-induced interleukin-1 beta mRNA induction in mouse spleen leukocytes.

Mice were fed a diet supplemented either with beef tallow (BT), BT plus ethyl eicosapentaenoate (EPA) or BT plus ethyl docosahexaenoate (DHA) for 9 weeks. EPA and DHA supplementation increased the content of the respective fatty acid in spleen leukocyte lipids, which was associated with the reduction in the arachidonate content. IL-1beta mRNA induction upon lipopolysaccharide (LPS) stimulation in spleen leukocytes in the DHA diet group was significantly lower than in the BT diet group, but the EPA diet was without any significant effect. The amount of prostaglandin E2 (PGE2) released from LPS-stimulated spleen leukocytes was significantly lower in both the EPA and DHA groups than in the BT group. Thus, dietary EPA and DHA inhibited arachidonate metabolism similarly but had different effects on IL-1beta mRNA induction in mouse spleen leukocytes.

Animals↗
PubMed2000

Transperineal magnetic resonance image guided prostate biopsy.

PURPOSE: We report the findings of a transperineal magnetic resonance image (MRI) guided biopsy of the prostate in a man with increasing prostate specific antigen who was not a candidate for a transrectal ultrasound guided biopsy. MATERIALS AND METHODS: Using an open configuration 0.5 Tesla MRI scanner and pelvic coil, a random sextant sample was obtained under real time MRI guidance from the peripheral zone of the prostate gland as well as a single core from each MRI defined lesion. The patient had previously undergone proctocolectomy for ulcerative colitis and, therefore, was not a candidate for transrectal ultrasound guided biopsy. Prior attempts to make the diagnosis of prostate cancer using a transurethral approach were unsuccessful. RESULTS: The random sextant samples contained benign prostatic hyperplasia, whereas Gleason grade 3 + 3 = 6 adenocarcinoma was confirmed in 15% and 25% of the 2 cores obtained from the MRI targeted specimens of 2 defined lesions. The procedure was well tolerated by the patient. CONCLUSIONS: Transperineal MRI guided biopsy is a new technique that may be useful in detecting prostate cancer in men with increasing prostate specific antigen who are not candidates for transrectal ultrasound guided biopsy.

Adenocarcinoma↗
PubMed2000

Acute cerebellar hemorrhage in a patient with Klinefelter syndrome: XXY karyotype obtained postmortem from cells from pericardial fluid.

A case of Klinefelter syndrome and a spontaneous cerebellar hemorrhage in a 12-year-old boy is presented. Autopsy revealed that the hemorrhage was due to the rupture of a dilated artery in an arteriovenous malformation in the right cerebellar hemisphere. The small, undescended testes exhibited partial atrophy of the seminiferous tubules. Postmortem chromosome analysis of cells from the pericardial fluid demonstrated a 47, XXY karyotype. He had previous surgical treatment for bilateral thumb polydactyly and patent ductus arteriosus. In juvenile cases of sudden death with overlapping morphological dysgenesis, postmortem karyotyping may provide important diagnostic information.

Cause of Death↗
PubMed1999

Chronic administration of docosahexaenoic acid improves reference memory-related learning ability in young rats.

Wistar rats were fed a fish oil-deficient diet through three generations. The young (five-week-old) male rats of the third generation were randomly divided into two groups. Over 10 weeks, one group was perorally administered docosahexaenoic acid dissolved in 5% gum Arabic solution at 300 mg/kg/day; the other group received a similar volume of vehicle alone. Five weeks after starting the administration, the rats were tested for learning ability related to two types of memory, reference memory and working memory, with the partially (four of eight) baited eight-arm radial maze. Reference memory is information that should be retained until the next trial. Working memory is information that disappears in a short time. Entries into unbaited arms and repeated entries into visited arms were defined as reference memory errors and working memory errors, respectively. Docosahexaenoic acid administration over 10 weeks significantly reduced the number of reference memory errors, without affecting the number of working memory errors, and significantly increased the docosahexaenoic acid content and the docosahexaenoic acid/arachidonic acid ratio in both the hippocampus and the cerebral cortex. In addition, the ratio demonstrated a significantly negative correlation with the number of reference memory errors. These results suggest that chronic administration of docosahexaenoic acid is conducive to the improvement of reference memory-related learning ability, and that the docosahexaenoic acid/arachidonic acid ratio in the hippocampus or the cerebral cortex, or both, may be an indicator of learning ability.

Animals↗
PubMed1999

DNA polymorphisms in the 5'-flanking sequence of human ABO blood group genes and their association with the alleles for the common ABO phenotypes.

Previously we found that minisatellite located on the 5'-flanking sequence far from the transcription start site of the human ABO blood group genes and containing four tandem repeats of a 43 base pair (bp) consensus sequence was an enhancer element for the transcription of the ABO genes. Concerning the number of tandem repeats in the minisatellite, there are at least three alleles: ABOU1*1, ABOU1*3, and ABOU1*4. Besides the variability of the minisatellite, another location of the 5'-flanking sequence has two alleles associated with the insertion of the 35 bp DNA segment: ABOU2*0 allele with an uneventful sequence and ABOU2*1 allele with the 35-bp insertion, respectively. Both of the DNA polymorphisms are closely associated with the common alleles of blood group ABO phenotypes. Namely, the 5'-flanking configuration consisting of the alleles ABOU1*1 and ABOU2*0 links up with the common A1 allele, whereas, the other 5'-flanking configuration consisting of the alleles ABOU1*4 and ABOU2*1 links up with common B and O alleles (abbreviated as 1-0-A1, 4-1-B and 4-1-O). In these linkages between three loci of alleles of 102 unrelated healthy individuals, two are not consistent with the rules described above. One is 3-1-O and the other is 4-1-A2. These findings suggest that the 3 or 4 times repeats of a 43 bp consensus sequence at ABOU1 locus and the 35 bp-insertion at ABOU2 locus found in 5'-flanking sequence of the B and O genes are incidental to the ABO gene evolution, subject to the ancestral A1 gene.

Journal Article↗
PubMed1999

Dietary docosahexaenoic acid enhances ferric nitrilotriacetate-induced oxidative damage in mice but not when additional alpha-tocopherol is supplemented.

Weaning mice were fed a diet supplemented with beef tallow (BT) or BT plus docosahexaenoic acid (DHA) containing 100 mg alpha-tocopherol/kg (alpha-Toc100) or 500 mg alpha-tocopherol/kg (alpha-Toc500) for 4 wk to modify membrane fatty acid unsaturation, and then were administered ferric nitrilotriacetate (Fe-NTA). The mortality caused by Fe-NTA was higher in the group fed the DHA (alpha-Toc100) diet than in the BT diet groups but the DHA (alpha-Toc500) diet suppressed this increase. Serum and kidney alpha-tocopherol contents were slightly influenced by the dietary fatty acids but not significantly. These results indicate that the increased unsaturation of tissue lipids enhances oxidative damage induced by Fe-NTA in mice fed DHA (alpha-Toc100) but not when additional alpha-tocopherol is supplemented. The apparent discrepancy between the observed enhancement by dietary DHA of oxidative damage and the beneficial effects of dietary DHA on the so-called free radical diseases is discussed in terms of strong bolus oxidative stress and moderate chronic oxidative stress.

Animals↗
PubMed1999

The hypotensive effect of docosahexaenoic acid is associated with the enhanced release of ATP from the caudal artery of aged rats.

Fish oils have been shown to lower blood pressure in hypertensive subjects. To determine the mechanism of this hypotensive effect, we examined the effects of docosahexaenoic acid (DHA), one of the (n-3) polyunsaturated fatty acids in fish oil, on blood pressure and on the release of adenyl purines, such as ATP, ADP, AMP and adenosine, from the caudal arteries of aged rats. Aged female Wistar rats (100 wk) were fed a high cholesterol diet and were administered intragastrically ethyl all-cis-4,7,10,13,16,19-docosahexaenoate [300 mg/(kg.d)] for 12 wk (DHA group) or vehicle alone (control group). Compared with the controls, rats supplemented with DHA had significantly greater (10.1%) DHA concentrations in the caudal arteries. This was associated with more total (n-3) arterial fatty acids, a greater unsaturation index of arterial fatty acids, 43.9% lower plasma noradrenaline levels and the repression of the elevation in blood pressure observed with advancing age. The amount of purines released, both spontaneously and in response to noradrenaline, from arterial segments of DHA-supplemented rats was significantly higher than that released from tissues of control rats. Regression analysis revealed significant negative relationships between the total amount of purines released from the artery and the systolic (SBP) and diastolic (DBP) blood pressures. These results suggest that in aged rats, supplementation with DHA alters the membrane fatty acid composition as well as the amount of ATP released from vascular endothelial cells and decreases plasma noradrenaline, and that these factors may ameliorate the rise in blood pressure normally associated with advancing age.

Adenosine Triphosphate↗
PubMed1998

Positive feedback regulation of type I IFN genes by the IFN-inducible transcription factor IRF-7.

The interferon regulatory factor (IRF) family of transcription factors regulate the interferon (IFN) system, among which IRF-3 is involved in the virus-induced IFN-beta gene expression. Here we show that another member IRF-7 is critical for the IFN-alpha gene induction. Unlike the IRF-3 gene, the IRF-7 gene is induced by IFNs through activation of the ISGF3 transcription factor, and IRF-7 undergoes virus-induced nuclear translocation. In cells lacking p48, an essential component of IFN stimulated gene factor 3 (ISGF3), ectopic expression of IRF-7 but not IRF-3 can rescue the deficiency to induce IFN-alpha genes. These results indicate that IRF-7 is a key factor in the positive feedback regulation of IFN-alpha/beta production.

Amino Acid Sequence↗