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Biomedical subjects

H Yoshioka

Publications and source records attributed to H Yoshioka.

At least 127 records · Page 7Linked to original sources
PubMed1998

National survey of periventricular leukomalacia in Japan.

BACKGROUND: Clarification of the present status of periventricular leukomalacia (PVL) in Japan. METHODS: Questionnaires were mailed to the leading neonatal intensive care units (NICU) and rehabilitation centers for children. RESULTS: The incidence of PVL in the group of surviving preterm infants of gestational ages less than 33 weeks was 4.8-4.9% on ultrasound and 7.7-7.9% on magnetic resonance imaging and/or computed tomography. The incidence of PVL did not decrease between 1990 and 1994. The incidence of PVL in the NICU varied from 0 to 47.1%. Infants from multiple pregnancies had a higher incidence (9.1%) of PVL than those from single pregnancies (6.2%). The proportion of PVL in all patients in rehabilitation centers with cerebral palsy (CP) has increased recently. CONCLUSIONS: It was roughly calculated that about 750 cases of CP with PVL occurred annually in Japan, thus accounting for about one-third of the total number of cases of CP.

Cerebral Palsy↗
PubMed1998

Role of ABC transporters in aureobasidin A resistance.

Aureobasidin A (AbA) has strong antifungal effects arising from an unusual mechanism. We show that AbA interacts with ATP-binding cassette (ABC) transporters in yeast and mammalian cells. We isolated a gene of Saccharomyces cerevisiae that conferred resistance to AbA when the gene was present in multiple copies. The gene was identical to YOR1/YRS1, which confers resistance to oligomycin, reveromycin, and organic anions, none of which have structures similar to that of AbA. We also isolated an aur3R recessive mutant of S. cerevisiae with increased resistance to AbA. Northern hybridization showed that the aur3R mutant expressed not only YOR1 but also the ABC transporter-encoding gene PDR5 at high levels. Genetic studies showed that the aur3R mutant had a mutation in the PDR1 gene, which encodes a transcriptional regulator of PDR5 and YOR1. Analysis of a yor1 disruptant of the aur3/pdr1 mutant showed that both the functional YOR1 gene and the mutation in PDR1 were necessary for AbA resistance. These results suggest that YOR1 is more important than PDR5 for AbA resistance. We found in Candida albicans a novel gene whose sequence was similar to the sequence of YOR1 in S. cerevisiae. The amino acid sequence of the C. albicans YOR1 homolog showed no significant similarity to the sequences of CDR1 and CDR2, which are ABC transporters of C. albicans. Furthermore, AbA inhibited the efflux of the anticancer agent vincristine through P glycoproteins in cancer cells with multidrug resistance.

ATP-Binding Cassette Transporters↗
PubMed1998

Correlation of wing-leg identity in ectopic FGF-induced chimeric limbs with the differential expression of chick Tbx5 and Tbx4.

It has been reported that members of the fibroblast growth factor (FGF) family can induce additional limb formation in the flank of chick embryos. The phenotype of the ectopic limb depends on the somite level at which it forms: limbs in the anterior flank resemble wings, whereas those in the posterior flank resemble legs. Ectopic limbs located in the mid-flank appear chimeric, possessing characteristics of both wings and legs; feather buds are present in the anterior halves with scales and claws in the posterior halves. To study the mechanisms underlying the chimerism of these additional limbs, we cloned chick Tbx5 and Tbx4 to use as forelimb and hindlimb markers and examined their expression patterns in FGF-induced limb buds. We found that Tbx5 and Tbx4 were differentially expressed in the anterior and posterior halves of additional limb buds in the mid-flank, respectively, consistent with the chimeric patterns of the integument. A boundary of Tbx5/Tbx4 exists in all ectopic limbs, indicating that the additional limbs are essentially chimeric, although the degree of chimerism is dependent on the position. The boundary of Tbx5/Tbx4 expression is not fixed at a specific position within the interlimb region, but dependent upon where FGF was applied. Since the ectopic expression patterns of Tbx5/Tbx4 in the additional limbs are closely correlated with the patterns of their chimeric phenotypes, it is likely that Tbx5 and Tbx4 expression in the limb bud is involved in determination of the forelimb and hindlimb identities, respectively, in vertebrates.

Amino Acid Sequence↗
PubMed1998

Release of nitric oxide from a spin trap, N-tert-butyl-alpha-phenylnitrone, under various oxidative conditions.

Nitric oxide (NO) generation from a spin trap, N-tert-butyl-alpha-phenylnitrone (PBN) under various oxidative conditions was examined. The absorbance of PBN at 295 nm decreased with time of UV-irradiation, showing that PBN was decomposed by UV irradiation. The hydroxyl radical formed from a Fenton reagent also decomposed PBN, but there was little effect by a peroxyl radical and a superoxide. Nitrite, an oxidative product of NO, in PBN solution was determined using a NOx analyzer based on Griess reaction. UV-irradiation and the hydroxyl radical also formed nitrite. Direct detection of NO from the sample on reaction with hydroxyl radical was successful using a GC/MS/SIM on the UV-irradiated sample. NO generated in PBN solutions activated guanylate cyclase. From these results, PBN is viewed as a new kind of medicine which acts as an antioxidant and as an NO donor in vivo.

Animals↗
PubMed1998

A spin trap, N-tert-butyl-alpha-phenylnitrone extends the life span of mice.

To characterize the pharmacological effects of N-tert-butyl-alpha-phenylnitrone (PBN) on life span, we administered PBN in drinking water to 24.5-month-old mice, and the survivors were counted. Their water consumption and body weights were measured as biological markers. PBN-treated animals as compared with control animals had prolonged mean and maximum life spans. Their water consumption decreased but no significant change was found in their body weights, indicating that the metabolism was improved. Results showed that PBN indeed affects physiological functions and extends life span. We propose that nitric oxide release from PBN may be involved in altering the aging process.

Animals↗
PubMed1998

Expression of type XVII collagen alpha 1 chain mRNA in the mouse heart.

The type XVII collagen alpha 1 chain has been identified as a component of the type I hemidesmosome, and is thus thought to play a role in extracellular matrix (ECM) maintenance and signal transduction between the cell and the ECM. We examined the expression of type XVII collagen alpha 1 chain mRNA in the mouse heart by Northern blot analysis and determined the sequential changes of its expression in different developmental stages of the heart using the reverse transcriptase-polymerase chain reaction (RT-PCR) method. Northern blotting: Total RNA was extracted from 10 adult mouse hearts by the guanidine/cesium method. Hybridization was performed with mouse cDNA for alpha 1 (XVII) collagen. RT-PCR: Total RNA was extracted from 7 embryos, 4 neonates and 8 adult mice. Reverse transcription was performed using oligo-dT primer and MMLV. Amplification was carried out in alpha 1 (XVII) collagen and glyceraldehyde 3-phosphate dehydrogenase (GAPDH). GAPDH served as an internal control. Northern blotting revealed a 5.6 kb signal that was identical to that of the alpha 1 (XVII) of skin and transformed keratinocyte reported previously. The sequences of the PCR products were also identical to those reported. The normalized expression ratios of alpha 1 (XVII) were 0.91 +/- 0.20 in the embryonic heart, 0.36 +/- 0.20 in the neonatal heart and 0.96 +/- 0.21 in the adult heart. In conclusion, we identified the expression of type XVII collagen alpha 1 chain mRNA in the mouse heart, suggesting that the type I hemidesmosome is located in the heart. The results of the RT-PCR at different developmental stages of the heart suggest that type XVII collagen contributes not only to cardiogenesis in the embryonic stage but also to maintenance of architecture and function in the adult heart.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Transcatheter embolization of celiac artery pseudoaneurysm following pancreatico-duodenectomy for pancreatic cancer. A case report.

A case of transcatheter embolization of a celiac artery pseudoaneurysm in a 70-year-old man is reported. The pseudoaneurysm was considered to be the result of pancreatic anastomotic leakage and an intra-abdominal abscess following pancreaticoduodenectomy with irradiation of 66 Gy for pancreatic carcinoma. To avoid recanalization of the pseudoaneurysm due to retrograde blood flow, first all branches of the celiac artery were embolized with metallic coils, and then the celiac trunk was also occluded. Hepatic arterial flow was preserved by the right hepatic artery arising from the superior mesenteric artery. After the procedure, the patient had no noticeable complications associated with the embolization nor any recurrence of the pancreatic cancer, and he achieved a 2-year survival.

Aged↗
PubMed1998

Total body bone development during early childhood in very low birth weight infants without cerebral palsy and mental retardation.

Total body bone mineral density was measured by dual energy X-ray absorptiometry in 52 children who were very low birth weight (VLBW) infants without cerebral palsy and mental retardation (postconceptional age, from 10 mo to 6 y and 6 mo). VLBW infants in this study seemed to show compensatory acceleration of total body bone development, catching up with the control group during early childhood. However, in VLBW infants with at least one of the three factors such as total parenteral nutrition for 1 week or more, assisted ventilation for 1 week or more, or oxygen therapy for 28 d or more in their early stage after birth, adequate mineral supplementation might be especially important for long-term bone development.

Aging↗
PubMed1998

[A case of intrathoracic chronic expanding hematoma].

A chronic expanding hematoma in the thoracic cavity is very rare and is clinically included in a category of chronic hemorrhagic empyemas as a special type of chronic empyemas in Japan. In this paper, we report a case of this disease. The patient was a 69-year-old female, who was underwent bilateral artificial pneumothorax for pulmonary tuberculosis 35 years ago. On 25. Nov. 1996, she admitted into Nagoya University Hospital for a diagnosis of intrathoracic tumor. On 2. Dec. 1996, we removed the tumor with combined resection of left lower lobe. The tumor was diagnosed pathologically as an intrathoracic chronic expanding hematoma. This disease is benign, but progressive clinically. In progressive case it is dangerous to remove the tumor for a risk of excessive bleeding and hard adhesion to the chest wall. So we think the earlier is a surgical treatment, the better is a management for this disease.

Aged↗
PubMed1998

[Usefulness of a new technique to assess drug perfusion pattern on balloon occluded arterial infusion therapy (BOAI) for intrapelvic malignant neoplasms: subtraction CT with low-flow-rate arterial injection (S-CTLA)].

The hemodynamics in balloon occluded arterial infusion therapy (BOAI) for intrapelvic malignant neoplasms is not totally understood. A new technique to evaluate the perfusion pattern of anticancer drugs under BOAI, which is named Subtraction CT with Low-flow-rate Arterial injection (S-CTLA), has been developed by us. In this technique, spiral CT data were acquired twice, before and after low-flow-rate (0.2 ml/sec) injection of contrast agent. Then, subtraction images were reconstructed. S-CTLA was performed in 3 patients with urinary bladder cancer. Our results provided demonstrable images as well as useful information in predicting the effectiveness of BOAI.

Aged↗
PubMed1998

[A case of neurofibromatosis type I associated with basal meningocele and abnormal vessels].

A 21-year-old man with neurofibromatosis type 1 (NF 1) had many widespread cutaneous neurofibroma on his right face. Magnetic resonance imaging (MRI) revealed basal meningocele due to dysplasia of the skull base. Carotid and vertebral angiograms revealed occlusion of the right internal carotid artery, persistent primitive trigeminal artery. We have reviewed the clinical and radiographic features of this case of neurofibromatosis, meningocele and cerebral arterial abnormalities. NF associated with both intracranial vascular malformation and meningocele is very rare, and in our case both were thought to arise congenitally as a manifestation of mesodermal dysplasia. Careful follow up using MRI and MR angiography should be performed for such patients.

Adult↗
PubMed1998

[Neoadjuvant intraarterial chemotherapy for ten cases of inflammatory breast cancer by Seldinger's methods].

The conventional methods (CM) of intraarterial (IA) chemotherapy for inflammatory breast cancer were catheterizations from superior epigastric and brachial artery under general anesthesia. Since 1997, we selected the Seldinger's methods (SM) for ten cases of the disease to control local effects and simplify the technique. Complications of the SM were slight, and side effects were equal to those with CM. The postoperative pathological findings of the SM showed the direct effects of chemotherapy to tumor cells (degenerative and necrotic changes) as compared with the embolism-like effects of CM. But the overall histological effects of chemotherapy by SM were almost equal to those for CM. The strong points of the SM were as follows: 1) More selective IA chemotherapy is available, 2) one can find the passage of the aim vessels and no trouble related to catheter, 3) general anesthesia is not necessary, and the techniques are simple, 4) the wounds are not remarkable. The disadvantages are as follows: 1) Patients must rest the day of IA chemotherapy, 2) in 20% of the procedures, one can not search the vessels, and 3) in 4 cases complications of stiffness of Mj or Mn pectral muscles were found. In future, we expect more effective results by dose escalation or combination chemotherapy.

Adenocarcinoma↗
PubMed1998

[Desmoid tumor of the chest wall: a case report].

A 45-year-old man was referred to our hospital for recurrent desmoid tumor of the chest wall. He underwent chest wall resection with reconstruction of Marlex mesh. But we could not resect it enough widely, because the tumor invaded beside left subclavian artery and subclavian vein, brachioflexus. So he had additional radiation therapy (50 gry). The patient is now doing well without recurrence 1 year after the operation.

Fibromatosis, Abdominal↗
PubMed1997

A transcription activator with restricted tissue distribution regulates cell-specific expression of alpha1(XI) collagen.

Different regulatory programs are likely to control expression of the alpha1(XI) collagen (COL11A1) gene in cartilaginous and non-cartilaginous tissues and in coordination with different collagen genes. Here, we report the identification of a cis-acting element that is required for constitutive and tissue-specific activity of the proximal COL11A1 promoter. The element binds an apparently novel activator whose expression is restricted mostly, but not exclusively, to cells of mesenchymal origin. Transient transfection experiments using wild-type and mutant constructs demonstrated the critical contribution of a 45-base pair upstream element (FP9) to promoter activity. The same functional tests and DNA binding assays narrowed down the critical portion of FP9 to a 20-base pair sequence, which consists of an imperfect palindrome with strong homology to the GATA consensus motif. Despite being able to bind GATA proteins in vitro, FP9 is actually recognized by a distinct approximately 100-kDa polypeptide (FP9C) probably belonging to the zinc-finger family of transcription factors. FP9C binding was mostly identified in nuclei from cells of mesenchymal origin, including those actively engaged in COL11A1 transcription. A positive correlation was also established between the level of FP9C binding and the degree of cell differentiation in vitro. Thus, FP9C represents an unusual example of tissue-specific and differentiation-related transcription factor with overlapping expression in hard and soft connective tissues.

3T3 Cells↗