Biomedical subjects

T Hara

Publications and source records attributed to T Hara.

At least 181 records · Page 10Linked to original sources

PubMed2001

Unrelated cord blood transplantation for an infant with chemotherapy-resistant progressive Langerhans cell histiocytosis.

The authors describe a patient successfully treated with unrelated cord blood transplantation (CBT) for chemotherapy-resistant progressive Langerhans cell histiocytosis (LCH). An 8-month-old boy had LCH diagnosed based on the histologic examination of skin lesions. Despite intensive chemotherapy and immunotherapy, the disease was progressive, with organ dysfunction. He received unrelated CBT after a conditioning regimen consisting of total body irradiation, etoposide, and melphalan. He was in complete remission 12 months after the transplantation. The authors suggest that CBT could be considered in the treatment of patients with chemotherapy-resistant progressive LCH, especially if there are no available human leukocyte antigen-matched family donors.

Combined Modality Therapy↗

PubMed2001

Inflammatory bowel disease-like colitis in glycogen storage disease type 1b.

Chronic inflammatory bowel disease (IBD)-like colitis is occasionally associated with glycogen storage disease-type 1b (GSD-1b). We describe a 17-year old boy with GSD-1b who developed an IBD-like colitis. Roentgenography and colonoscopy showed the lead-pipe appearance of the colon and circumferential ulcers. Histopathologic examination revealed nonspecific inflammation without granulomatous lesions. High-dose granulocyte-colony stimulating factor (G-CSF) and sulfasalazine led to the resolution of the colitis, although neutropenia continued. Besides this case, 10 published cases of GSD-1b and IBD-like colitis were reviewed. All cases had severe neutropenia and/or neutrophil dysfunction. The mean onset of bowel disease was 12.3 years of age. Seven cases required surgical treatment. All five patients with G-CSF/GM-CSF therapy showed clinical remission. These findings suggest that IBD-like colitis is a grave complication of GSD-1b and that recurrent enteric infections due to neutrophil deficiency may contribute to the development of this bowel disease.

Adolescent↗

PubMed2001

Long-term follow-up of initial 5-fluorouracil trabeculectomy in primary open-angle glaucoma in Japanese patients.

PURPOSE: To evaluate the long-term efficacy and safety of initial trabeculectomy with subconjunctival 5-fluorouracil in Japanese patients with primary open-angle glaucoma. SUBJECTS AND METHODS: Clinical records of 117 eyes from 117 patients with records of up to 14 years were retrospectively analyzed using the appropriate statistical methods. RESULTS: The mean follow-up period was 6.2 +/- 3.6 years. Criteria for successful intraocular pressure control and success probability by Kaplan-Meier method at 12 years were intraocular pressure < 21 mm Hg without medication plus a 30% or more reduction in intraocular pressure, 50.4 +/- 5.2% (SE) 38.2 +/- 5.3%; and intraocular pressure < 16 mm Hg without medication plus a 30% or more reduction in intraocular pressure, 45.9 +/- 5.1% (36.5 +/- 5.2%). Cox multiple regression analysis showed that a younger age was associated with a higher success probability (P <0.01). Eyes with lower postoperative intraocular pressure tended to show more positive value of the MD slope (P = 0.0669), whereas 7% of successfully treated eyes showed a negative postoperative MD slope (P < 0.1). The probabilities for developing bleb leaks and bleb-related infections in eyes with a functioning bleb were 28.9 +/- 12.5% and 13.0 +/- 10.4% at 12 years. CONCLUSION: Trabeculectomy with 5-fluorouracil as an initial surgery in Japanese patients with primary open-angle glaucoma was effective for long-term control of glaucoma. However, the probability of late-onset bleb-related complications was not low in eyes with a functioning bleb, stressing the importance of constant care regarding bleb status.

Adult↗

PubMed2001

Automated detection of pulmonary nodules in helical CT images based on an improved template-matching technique.

The purpose of this study is to develop a technique for computer-aided diagnosis (CAD) systems to detect lung nodules in helical X-ray pulmonary computed tomography CT) images. We propose a novel template-matching technique based on a genetic algorithm (GA) template matching (GATM) for detecting nodules existing within the lung area; the GA was used to determine the target position in the observed image efficiently and to select an adequate template image from several reference patterns for quick template matching. In addition, a conventional template matching was employed to detect nodules existing on the lung wall area, lung wall template matching (LWTM), where semicircular models were used as reference patterns; the semicircular models were rotated according to the angle of the target point on the contour of the lung wall. After initial detecting candidates using the two template-matching methods, we extracted a total of 13 feature values and used them to eliminate false-positive findings. Twenty clinical cases involving a total of 557 sectional images were used in this study. 71 nodules out of 98 were correctly detected by our scheme (i.e., a detection rate of about 72%), with the number of false positives at approximately 1.1/sectional image. Our present results show that our scheme can be regarded as a technique for CAD systems to detect nodules in helical CT pulmonary images.

Algorithms↗

PubMed2001

Development of an automated method for detecting mammographic masses with a partial loss of region.

Recently, we have been developing several automated algorithms for detecting masses on mammograms. For our algorithm, we devised an adaptive thresholding technique for detecting masses, but our system failed to detect masses with a partial loss of region that were located on the edge of the film. This is a common issue in all of the algorithms developed so far by other groups. In order to deal with this problem, we propose a new method in the present study. The partial loss masses are identified by their similarity to a sector-form model in the template matching process. To calculate the similarity, four features are applied: 1) average pixel value; 2) standard deviation of pixel values; 3) standard correlation coefficient defined by the sector-form model; and 4) concentration feature determined from the density gradient. After employing the new method to 335 digitized mammograms, the detection sensitivity for the partial loss masses jumped from 70% to 90% when the number of false positives was kept constant (0.2/image). Moreover, a combination of the existing method and the new method improved the true-positive rate up to 97%. Such results indicate that the new technique may improve the performance of our computer-aided diagnosis system for mammographic masses effectively.

Algorithms↗

PubMed2001

Delayed onset of systemic bacterial dissemination and subsequent death in mice injected intramuscularly with Streptococcus pyogenes strains.

Streptococcus pyogenes causes severe invasive diseases in humans, including necrotizing fasciitis, sepsis, and streptococcal toxic shock syndrome (STSS). We found that mice infected intramuscularly (i.m.) with S. pyogenes strains developed bacteremia and subsequent sudden death after at least 10 days of a convalescent period. Mostly, it occurred more than 21 days after muscle infection. We provisionally designate this phenomenon as "delayed death." Just after muscle infection, all the mice lost weight and activity, but recovered completely within 3 days. They had kept good activity and a fine coat of fur till one or two days before their death. Some of the dead mice were found to have soft-tissue necrosis. There was no correlation between the virulence leading to the delayed death and the severity of diseases from which strains were isolated. It was also found that the production of neither streptococcal pyrogenic exotoxin (SPE) A nor B correlated to the virulence leading to delayed death. The bacteria obtained from the organs of the mice with delayed death expressed capsule. We suggest that the mice with delayed onset of systemic bacterial dissemination and subsequent death after muscle infection with S. pyogenes are the animal models of STSS, because the pathophysiology is extremely similar to that of human STSS.

Animals↗

PubMed2001

Gene expressions after thrombolytic treatment of middle cerebral artery clot embolism in mice.

BACKGROUND AND PURPOSE: Thrombolytic treatment of stroke may result in reperfusion injury. To investigate the role of selective gene expressions, C57Bl/6J mice were subjected to middle cerebral artery (MCA) clot embolism, followed after 1 hour by intracarotid infusion of 10 mg/kg recombinant tissue plasminogen activator (rtPA) or vehicle. METHODS: Before the onset of treatment and at 1, 3, 6, and 24 hours of recirculation, animals were frozen in situ and hsp70, c-fos, junB, and NSE mRNAs were imaged on cryostat sections using in situ hybridization autoradiography. Cerebral protein synthesis (CPS) and ATP content were measured on adjacent brain sections. RESULTS: hsp70 mRNA was upregulated in the penumbral cortex of untreated animals and in the MCA core region of animals receiving rtPA (ie, regions characterized by a mismatch between high ATP levels and suppressed CPS). c-fos and junB mRNAs were transiently expressed mainly in the peri-infarct intact cortex for up to 3 to 6 hours in the treated and up to 24 hours in the untreated animals. In both groups, NSE mRNA declined in the central parts of the MCA territory together with a loss of silver impregnation, but this decline was more pronounced in the untreated animals. CONCLUSIONS: The genomic expression pattern after thrombolytic recanalization of clot embolism resembles that of other types of transient ischemia such as reversible thread occlusion, although the outcome is markedly different. The investigated gene expressions, notably hsp70 mRNA, reflect the kind and severity of the ischemic stress, but they do not predict reversibility of the ischemic injury.

Adenosine Triphosphate↗

PubMed2001

Interleukin-18 in human milk.

We analyzed IL-18 levels of human milk. Colostrum contained significantly higher levels of IL-18 compared with early milk and mature milk. By stepwise multiple linear regression analysis, preterm delivery and pregnancy complications of mothers significantly correlated with high levels of IL-18 in human milk (p = 0.0007 and 0.0018, respectively). There was a significant correlation between the levels of IL-18 and soluble Fas ligand in colostrum (p = 0.0003). IL-18 was detected in actively secreting epithelial cells in lactating mammary gland by immunohistochemical staining. These results suggest that IL-18 in colostrum plays an important role in host defense of high-risk neonates.

Base Sequence↗

PubMed2001

Physical growth and retinopathy in preterm infants: involvement of IGF-I and GH.

GH and IGF-I are important for physical growth. We measured serum levels of these factors in preterm infants. The study population (n = 81) was divided into three groups according to the gestational age. We evaluated differences in serum GH and IGF-I levels among groups with regard to physical growth and development of retinopathy of prematurity. Serum GH levels in extremely preterm infants born at <28 wk of gestational age were significantly higher than levels in those born between 28 and 34 wk at 1 and 2 mo of age. In contrast, serum IGF-I levels in extremely preterm infants remained low, whereas those in the other two groups gradually increased. Evaluation of the effects of GH and IGF-I on physical growth in very low birth weight infants (<1500 g) showed that IGF-I concentrations were positively related to physical growth for several months after birth, whereas no relationship was observed between GH and physical growth. Multivariate analysis demonstrated that high GH concentration at 1 mo of age was significantly associated with development of severe retinopathy of prematurity. In conclusion, persistent low serum IGF-I levels may explain the slow physical growth during neonatal life, and exposure of high GH may cause, at least in part, severe retinopathy of prematurity in preterm infants.

Disease Progression↗

PubMed2001

Exercise improved accumulation of visceral fat and simultaneously impaired endothelium-dependent relaxation in old rats.

Exercise decreases plasma total cholesterol and triglycerides, and simultaneously, increases high density lipoprotein (HDL) cholesterol. Furthermore, it has been reported that exercise improves insulin resistance. As a result, exercise is believed to aid in preventing atherosclerosis. However, we do not know whether exercise protects against the development of atherosclerosis in the elderly. The aim of this study was to ascertain whether exercise prevented atherosclerosis in aorta of old rats. Exercise for three months did not affect plasma lipid levels but decreased accumulation of visceral fat and body weight without the reduction of food intake in two year old rats. Exercise also decreased triglycerides in liver and gastrocnemius white muscle. Exercise resulted in an elevation of plasma lipid peroxide (LPO) levels without affecting superoxide dismutase (SOD). Exercise impaired the endothelium-dependent relaxation of the thoracic aorta caused by acetylcholine in old rats. In summary, the results of our study indicate that exercise induces the reduction of visceral fat, body weight and triglyceride contents in tissues in old rats. These results seems to show that exercise improves insulin resistance. However, exercise simultaneously may cause impaired endothelium-dependent relaxation by elevation of LPO in old rats.

Adipose Tissue↗

PubMed2001

Induction and secretion of RNA-degrading enzymes by phosphate deficiency in Pholiota nameko.

Changes in activity of RNA-degrading enzyme and amounts of phosphorus in mycelia and culture filtrate during Pi-sufficient and -deficient cultures of Pholiota nameko were investigated. The results showed that the intracellular and extracellular activities are controlled by the Pi concentration in the medium. Moreover, the induction and secretion of RNA-degrading enzymes under the Pi-deficient condition were analyzed by activity staining.

Acid Phosphatase↗

PubMed2001

Somatic-cell mutation induced by UVA and monochromatic UV radiation in repair-proficient and -deficient Drosophila melanogaster.

Near-ultraviolet light (UVA: 320-400 nm) constitutes a major part of sunlight UV. It is important to know the effect of UVA on the biological activities of organisms on the earth. We have previously reported that black light induces somatic-cell mutation in Drosophila larvae. To investigate which wavelength of the UVA is responsible for the mutation we have now carried out a series of monochromatic irradiations (310, 320, 330, 340, 360, 380 and 400 nm) on Drosophila larvae, using the large spectrograph of the National Institute for Basic Biology (Okazaki National Research Institutes, Okazaki, Japan). Mutagenic activity was examined by the Drosophila wing-spot test in which we observe mutant wing hair colonies (spots) on the wings of adult flies obtained from the treated larvae. The induction of mutation was highest by irradiation at 310 nm and decreased as the wavelength became longer. Neither the 380 nor the 400 nm light was mutagenic. Excision repair is known to protect cells from UV damage. In the excision-repair-deficient Drosophila, the mutagenic response induced by 310 nm irradiation was 24-fold higher than that of the wild-type (7.2 +/- 1.5 spots/wing/kJ vs 0.3 +/- 0.08 spots/wing/kJ), and at 320 nm the difference of the response was 14-fold (0.21 vs 0.015 +/- 0.005). In the case of irradiation at 330 and 340 nm the difference of the response was only two-fold (at 330 nm, 6.9 +/- 2.9 x 10(-3) vs 3.1 +/- 1.1 x 10(-3) spots/wing/kJ; at 340 nm, 3.5 +/- 0.9 x 10(-3) vs 2.0 +/- 0.7 x 10(-3). These results suggest that the lesion caused in the larvae by 320 nm irradiation may be similar to the damage induced by 310 nm and that the lights of 330 and 340 nm may induce damage different from the lesions induced by shorter-wavelength lights.

Animals↗

PubMed2001

A possible relationship between abortions and placental embolism in pregnant rabbits given human granulocyte colony-stimulating factor.

Developmental toxicity studies were conducted in rats and rabbits with a human G-CSF derivative (NTG). As reported for G-CSF, increases in abortions and fetal mortality were observed in rabbits, but not in rats given NTG. Histopathological examination of the rabbit placenta revealed accumulation of neutrophils in vessels and necrosis of the tissues surrounding these vessels. To assess the mechanism of abortion and fetal death in rabbits given G-CSF, 125I-labeled NTG was given intravenously on Day 18 of pregnancy after repeated administration of cold NTG on Days 6 through 17 of pregnancy, and the feto-maternal distribution of radioactivity was examined. In a rabbit given 20 micrograms/kg, high radioactivity was observed in the endometrium, placenta, and some parts of the decidua at 6 hr when the concentration of radioactivity in maternal blood had already decreased. At 24 hr after administration of 200 micrograms/kg NTG, high radioactivity was still detected in parts of the maternal placenta. These patterns of distribution suggest that embolism occurred in parts of the uterus and placenta which might have caused congestion. Radioactivity in the TCA precipitates in the fetus was low, suggesting that NTG does not readily transfer to the fetus. These results strongly suggest that neutrophils accumulated in the vessels of placenta and induced embolism leading to abortions and fetal mortality in the rabbits given G-CSF.

Absorption↗

PubMed2001

Anticipatory fall in core temperature in rats acclimated to heat given for various hours at a fixed daily time.

Rats were subjected to daily heat exposure limited to a fixed time for 10 consecutive days. An ambient temperature (T(a)) inside an animal room initially set at 24.0 degrees C was raised to 32.0 degrees C, starting at the middle of the dark phase. The high T(a) was maintained for a subsequent 1.5, 3, or 5 h and was then returned to 24.0 degrees C. After the heat exposure schedule, their core temperature significantly fell for about 30 min before and during the period when they had previously been exposed to heat without thermal stimuli. In rats, a time memory for heat exposure could be formed even when the duration of daily heat exposure was short.

Acclimatization↗

PubMed2001

Interleukin-18 in hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is characterized by dysregulated hyperactivation of macrophages and T helper 1 (Th1) cells accompanied by excessive secretion of inflammatory cytokines. Although TNF-alpha and IFN-gamma are known to be important factors for the development of the disease, the mechanism of their overproduction has not been clarified, yet. We measured serum IL-18 levels of patients with HLH to investigate the possible significance of IL-18 in its pathophysiology, especially in IFN-gamma production. IL-18 levels were significantly increased in all patients with HLH compared with healthy controls. A significant correlation was observed between IL-18 and IFN-gamma levels. In addition to IFN-gamma and soluble Fas ligand (sFasL), IL-18 levels significantly correlated with disease activity. IL-18 may play important roles in the pathogenesis of HLH, particularly through induction of Th1 cells. In addition, IL-18 measurement may not only be useful for the diagnosis, but also for the evaluation of disease activity.

Cytokines↗

PubMed2001

Brief exposure to low-pH stress causes irreversible damage to the growing root in Arabidopsis thaliana: pectin-Ca interaction may play an important role in proton rhizotoxicity.

The viability of Arabidopsis thaliana (strain Landsberg) roots exposed to a low pH (4.5 or 4.7) solution that contained 100 microM CaCl(2) was examined by staining with fluorescein diacetate-propidium iodide. The elongation zone of growing roots lost viability within 1-2 h following exposure to low pH, but non-growing roots showed no damage under the same treatment. Low-pH damage in growing roots was irreversible after 1 h incubation at pH 4.5 as judged by regrowth in growing medium at pH 5.6. Growing lateral roots also lost viability in the same treatment, whereas non-growing lateral roots remained viable during and after the treatment. The low-pH damage was ameliorated by the simultaneous application of calcium, indicating the involvement of a calcium-requiring process in overcoming proton toxicity. At pH 5.0, growing roots required 25 microM of calcium to maintain elongation, and at pH 4.8 and pH 4.5 more than 250 microM and 750 microM, respectively. The low-pH damage was ameliorated by divalent cations in the order of Ba2+, approximately Sr2+>/=Ca2+>Mg2+. The monovalent cation K+ showed no ameliorative effect, but borate showed a strong ameliorative effect with Ca2+. These results indicate that the primary target of proton toxicity may be linked to a disturbance of the stability in the pectic polysaccharide network, where calcium plays a key role in plant roots.

Arabidopsis↗

PubMed2001

[Combination effect of arbekacin and cefepime on mixed culture of MRSA and P. aeruginosa].

We investigated the in vitro combination effects of arbekacin (ABK), vancomycin (VCM) or teicoplanin (TEIC) and cefepime (CFPM) on methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa isolated from various clinical specimens. Using checkerboard titration technique by agar dilution, combinations of ABK, VCM or TEIC and CFPM exhibited synergistic effects on 25 MRSA strains. The similar effects were also observed on ABK-resistant MRSA. Combination of ABK and CFPM exhibited a good effect on P. aeruginosa, but combinations of VCM or TEIC and CFPM exhibited no synergistic effect on P. aeruginosa. In vitro bactericidal activities of ABK, VCM or TEIC and CFPM against mixed cultures of MRSA with P. aeruginosa were examined at concentration of each drug that corresponds to the serum concentration at 3 hours after the usual therapeutic dosage. VCM or TEIC alone showed bacteriostatic effects against MRSA, and no enhancements were observed when combined with CFPM. ABK alone showed good bactericidal activity against MRSA and combination with CFPM enhanced the bactericidal activity. Against P. aeruginosa, ABK or CFPM alone showed the bactericidal activity, and strong bactericidal activity was induced by the combination of ABK and CFPM. VCM and TEIC showed no bactericidal activities against P. aeruginosa. When CFPM combined with VCM or TEIC, the bactericidal activity of CFPM was not enhanced against P. aeruginosa.

Aminoglycosides↗

PubMed2001

[Multiple myeloma complicated by bilateral abducens nerve palsy due to a tumor in the clivus].

A 62-year-old woman was admitted to our hospital because of double vision. Bone marrow aspiration revealed normal cellularity with 21.6% atypical plasma cells. Immunoelectrophoresis revealed a monoclonal component of IgG kappa in the patient's serum. Coronal and sagittal cranial MRI images showed a tumor in the clivus behind the sella turcica. The patient was diagnosed as having multiple myeloma complicated by double vision due to compression of the bilateral abducens nerve by a plasmacytoma. VAD therapy consisting of vincristine, doxorubicin and dexamethasone, followed by irradiation of the clivus tumor achieved only a transient therapeutic effect, and the double vision and bone disease worsened. Cranial nerve palsy may be a significant complication of multiple myeloma.

Abducens Nerve Diseases↗