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Biomedical subjects

S Yasuda

Publications and source records attributed to S Yasuda.

At least 19 recordsLinked to original sources
PubMed2006

The wheat and barley vernalization gene VRN3 is an orthologue of FT.

Winter wheat and barley varieties require an extended exposure to low temperatures to accelerate flowering (vernalization), whereas spring varieties do not have this requirement. In this study, we show that in these species, the vernalization gene VRN3 is linked completely to a gene similar to Arabidopsis FLOWERING LOCUS T (FT). FT induction in the leaves results in a transmissible signal that promotes flowering. Transcript levels of the barley and wheat orthologues, designated as HvFT and TaFT, respectively, are significantly higher in plants homozygous for the dominant Vrn3 alleles (early flowering) than in plants homozygous for the recessive vrn3 alleles (late flowering). In wheat, the dominant Vrn3 allele is associated with the insertion of a retroelement in the TaFT promoter, whereas in barley, mutations in the HvFT first intron differentiate plants with dominant and recessive VRN3 alleles. Winter wheat plants transformed with the TaFT allele carrying the promoter retroelement insertion flowered significantly earlier than nontransgenic plants, supporting the identity between TaFT and VRN-B3. Statistical analyses of flowering times confirmed the presence of significant interactions between vernalization and FT allelic classes in both wheat and barley (P < 0.0001). These interactions were supported further by the observed up-regulation of HvFT transcript levels by vernalization in barley winter plants (P = 0.002). These results confirmed that the wheat and barley FT genes are responsible for natural allelic variation in vernalization requirement, providing additional sources of adaptive diversity to these economically important crops.

Adaptation, Physiological↗
PubMed2006

Brain abscess following intracerebral haemorrhage.

We report two cases of brain abscess, which developed at the site of an intracerebral haemorrhage (ICH) in a 75-year-old man and a 32-year-old-man. The patients recovered after surgical treatment and systemic antibiotic therapy. The route of infection could not be detected in either case. The literature contains only 13 reported cases of brain abscess as a complication of ICH. Although the interval from initial ICH to abscess formation ranged from 4 to 20 weeks, almost all patients had episodes of high fever, indicating the presence of systemic infection and bacterial seeding, 0-14 days after the onset of their ICH. Therefore, abscess formation appears to be caused by haematogenous seeding of infection in patients with ICH. Abscess formation should be considered when a patient deteriorates clinically with a febrile episode after an ICH.

Adult↗
PubMed2005

[Pulmonary hemangiopericytoma preoperatively diagnosed as mediastinal tumor; report of a case].

An asymptomatic 67-year-old female was admitted because of an abnormal shadow on chest X-ray. Computed tomography (CT) revealed that a well-marginated round mass with low density, about 4 cm in diameter, was located in the right hilum. The border was enhanced at contrast material-enhanced CT. Magnetic resonance imaging (MRI) [T2-weighted] showed the lesion as a high intensity tumor. Because of the extra-pleural sign on CT and normal results of broncho-fiberscopic (BFS) examination, mediastinal tumor was suspected. We performed thoracoscopic surgery and revealed that the tumor was in lung, not in mediastinum. Biopsy of the easy-bleeding tumor was performed. The histopathological diagnosis was hemangiopericytoma. There was no remarkable change for 1 years. Hemangiopericytomas should be considered in the differential diagnosis of well-marginated masses. Thoracoscopic surgery is the useful methods to diagnose the hemangiopericytoma.

Aged↗
PubMed2005

[Usefulness of the eradication of Helicobacter pylori for the patient with idiopathic thrombocytopenic purpura and lung cancer: report of a case].

A 61-year-old female was admitted because of an abnormal lung shadow on chest X-ray. She had suffered from idiopathic thrombocytopenic purpura (ITP) for more than 7 years. Computed tomography (CT) revealed that an irregular shadow, about 2 cm in diameter, was located in the upper lobe of the right lung. After intravenous immunogrobulin injections for 5 days, a hematology test indicated increased platelet counts and we performed thoracoscopic surgery successfully without blood transfusions. However, 4 months after surgery, a hematology test indicated decreased platelet counts again. Thirteen months after the operation, gastrointestinal fiberscopic examination showed Helicobacter pylori infection. After the urea breath test, eradication therapy let to a recovery in platelet counts.

Adenocarcinoma↗
PubMed2004

Preoperative radio/chemo-radiotherapy in combination with intraoperative radiotherapy for T3-4Nx rectal cancer.

AIMS: To analyse the results of a single institution experience of combined preoperative radio/chemo-radiotherapy and intraoperative electron-radiation therapy (IORT) for locally advanced rectal cancer and to compare the results with surgery alone retrospectively. METHODS: The study cohort comprised 99 patients with clinical T3-4NxM0 adenocarcinoma of the rectum who had received preoperative radio/chemo-radiotherapy, radical surgery, and IORT [Group I]. Until 1998, 67 patients were treated with radiation only [Group Ia], and after 1999, 32 patients were concurrently given tegafur and uracil (UFT) [Group Ib]. 68 patients with clinical T3-4NxM0 rectal cancer were treated with surgery alone [Group II]. RESULTS: The median follow-up was 67 months in Group I and 83 months in Group II. Local recurrence rate was 2% in Group I, which was significantly lower than 16% in Group II (p=0.002) Both disease-free survival and overall survival in Group I were significantly better than those in Group II (p=0.04, p=0.02, respectively). Sphincter preservation was possible in 78% in Group Ib, which was significantly more than 42% in Group Ia (p=0.002). CONCLUSIONS: The combined preoperative radio/chemo-radiotherapy and IORT for clinical T3-4Nx rectal cancer significantly reduces local recurrence and improves prognosis. Combination of preoperative radiotherapy and oral UFT improves the feasibility of sphincter-preservation.

Adenocarcinoma↗
PubMed2004

Cervical spondylosis with thoracic level Brown-Séquard syndrome.

Brown-Sequard Syndrome (BSS) caused by cervical spondylosis (CS) is rare. About 70% of patients with CS presenting with BSS show lesion-dermatome discrepancy, which may be due to spinal cord lamination. From the clinical point of view, this discrepancy should be carefully evaluated and these patients should be treated as an emergency.

Brown-Sequard Syndrome↗
PubMed2004

Normal pressure hydrocephalus after gamma knife radiosurgery for cerebellopontine angle meningioma.

There are no reports of hydrocephalus following radiosurgery for a meningioma. We report on a case where gamma knife therapy for a 4 cm diameter right cerebellopontine meningioma accelerated hydrocephalus three months post treatment. Examination of the cerebrospinal fluid (CSF) revealed a high protein level and thus, CSF malabsorption and CSF obstruction might have occurred after the radio surgery. It is important to consider this pathology, and the need for long term follow up.

Aged↗
PubMed2003

Effect of calcium antagonist on cerebral blood flow and oxygen metabolism in patients with hypertension and chronic major cerebral artery occlusion: a positron emission tomography study.

To evaluate the effect of a calcium antagonist, nilvadipine, on cerebral blood flow and oxygen metabolism, we prospectively examined five ischaemic stroke patients, with both hypertension and chronic major cerebral artery occlusion, using positron emission tomography. The blood pressure showed a significant decrease after 3 months of nilvadipine treatment, the cerebral blood flow in the affected regions showed a significant increase and the oxygen extraction fraction showed a significant decrease. We conclude that nilvadipine is a safe and effective anti-hypertensive agent for patients with both hypertension and chronic major cerebral artery occlusion.

Aged↗
PubMed2002

A 13C NMR study on the adsorption characteristics of HEMA to dentinal collagen.

To develop a more effective primer, we must understand how 2-hydroxyethylmethacrylate, the HEMA primer, enhances bonding at the resin-dentin interface. In this study, to obtain an insight into the adhesion mechanisms of adhesive resin to etched dentin through HEMA, we examined the adsorption characteristics of HEMA to dentinal collagen by using the 13C NMR technique. The addition of dentinal collagen to the HEMA solution resulted in a decrease in T(1) values of carbons attributed to the HEMA, thus reflecting an interaction between HEMA and collagen. Specifically, a reduction in the T(1) value in the ester carbonyl carbon attributed to HEMA greater than that in the other carbons suggested the formation of a hydrogen bond between the ester carbonyl group in HEMA and the dentinal collagen.

Acid Etching, Dental↗
PubMed2002

Significance of magnetic resonance imaging in the diagnosis of nodular regenerative hyperplasia of the liver complicated with systemic lupus erythematosus: a case report and review of the literature.

Nodular regenerative hyperplasia of the liver (NRH), characterized by multiple hepatic nodules in the absence of fibrosis, is a rare but important complication of systemic lupus erythematosus (SLE) associated with non-cirrhotic portal hypertension. The diagnosis of NRH is based on the pathological examination, and radiological findings of NRH are poorly documented. We report a case of a 40-year-old woman with SLE complicated with NRH. Sixteen years after diagnosis of SLE, esophageal varices were incidentally found and diagnosis of portal hypertension due to NRH was made by magnetic resonance imaging (MRI) and confirmed by needle liver biopsy. Although MRI showed the lesions as significant nodules, neither computed tomography nor ultrasonography could demonstrate the nodules. However, serial MRI showed significant enlargement of the nodules for 2 years Because NRH may lead to portal hypertension with life-threatening variceral haemorrhage in patients with SLE, MRI is a useful, non-invasive examination to screen the patients for its presence and follow-up. We reviewed the literature regarding NRH in SLE and discuss the management of the affected patients.

Adult↗
PubMed2002

Differential display of protein tyrosine kinase cDNAs from human fetal and adult brains.

Here we describe a differential display method for surveying the expression of most protein tyrosine kinases and applying it to cDNAs from human fetal and adult brains. The method involves two selective steps for processing the mRNA. At each step, degenerate oligonucleotide primers derived from highly conserved regions of the catalytic domain of the kinases are used. In the display with BstYI and BsiHKI digests of the cDNA, 65% and 59% of a total of 72 and 63 bands, respectively, represented fragments from a total of 27 different tyrosine kinases. The expression levels of the kinases in the display were comparable with those measured by RT-PCR. This method offers a relatively specific way to display differentially expressed gene families in any tissue and cell type.

Adult↗
PubMed2001

Acute rhabdomyolysis following administration of high-dose cyclophosphamide: case report.

Rhabdomyolysis is an unusual complication of hematopoietic stem cell transplantation (HSCT). Cyclophosphamide has been one of the key drugs in the most common preparative regimen for HSCT. We present here a rare case of acute rhabdomyolysis following administration of high-dose cyclophosphamide. A 47-year-old woman with adult T-cell leukemia in remission was treated with high-dose cyclophosphamide as a preparative regimen for allogeneic bone marrow transplantation. Nineteen hours later, general convulsions and acidosis suddenly occurred. Levels of serum creatine kinase (skeletal muscle type), myoglobin, and aldolase were markedly elevated to 32870 IU/l, 640 ng/ml, and 240.3 IU/l, respectively. Rhabdomyolysis caused by high-dose cyclophosphamide was diagnosed, and the preparative chemotherapy was discontinued. Subsequently, her muscular signs and symptoms improved, and the results of laboratory examinations returned to normal after 2 weeks. She had previously been treated with conventional doses of cyclophosphamide, doxorubicin, vincristine, and prednisolone without evidence of rhabdomyolysis. Acute rhabdomyolysis may be an adverse effect specific to high-dose cyclophosphamide therapy.

Acute Disease↗
PubMed2001

Human tryptase epsilon (PRSS22), a new member of the chromosome 16p13.3 family of human serine proteases expressed in airway epithelial cells.

Probing of the GenBank expressed sequence tag (EST) data base with varied human tryptase cDNAs identified two truncated ESTs that subsequently were found to encode overlapping portions of a novel human serine protease (designated tryptase epsilon or protease, serine S1 family member 22 (PRSS22)). The tryptase epsilon gene resides on chromosome 16p13.3 within a 2.5-Mb complex of serine protease genes. Although at least 7 of the 14 genes in this complex encode enzymatically active proteases, only one tryptase epsilon-like gene was identified. The trachea and esophagus were found to contain the highest steady-state levels of the tryptase epsilon transcript in adult humans. Although the tryptase epsilon transcript was scarce in adult human lung, it was present in abundance in fetal lung. Thus, the tryptase epsilon gene is expressed in the airways in a developmentally regulated manner that is different from that of other human tryptase genes. At the cellular level, tryptase epsilon is a major product of normal pulmonary epithelial cells, as well as varied transformed epithelial cell lines. Enzymatically active tryptase epsilon is also constitutively secreted from these cells. The amino acid sequence of human tryptase epsilon is 38-44% identical to those of human tryptase alpha, tryptase beta I, tryptase beta II, tryptase beta III, transmembrane tryptase/tryptase gamma, marapsin, and Esp-1/testisin. Nevertheless, comparative protein structure modeling and functional studies using recombinant material revealed that tryptase epsilon has a substrate preference distinct from that of its other family members. These data indicate that the products of the chromosome 16p13.3 complex of tryptase genes evolved to carry out varied functions in humans.

Adult↗
PubMed2001

Disparate effects of interleukin 11 and thrombopoietin on megakaryocytopoiesis in vitro.

The effects of interleukin-11 (IL-11) and thrombopoietin (TPO) on murine megakaryocytopoiesis were studied using a serum-free culture system. Acting alone, both IL-11 and TPO increased the number of acetylcholinesterase (AchE)(+)cells (megakaryocytes), the latter being more potent than the former. TPO, but not IL-11, increased the mean AchE activity per megakaryocyte (AchE activity/megakaryocyte). TPO increased both the number of megakaryocytes with high ploidy, and of those with low ploidy. In contrast, IL-11 increased only the number of megakaryocytes with high ploidy. The effect of TPO on megakaryocyte ploidy was stronger than that of IL-11. Both IL-11 and TPO increased the proportion of large megakaryocytes, but the latter was more potent than the former. While the stimulatory effects of IL-11 and TPO on the number of megakaryocytes were enhanced by IL-3 or stem cell factor (SCF), synergism of IL-11 or TPO with IL-3 or SCF in stimulating AchE activity/megakaryocyte was inconsistent. IL-11 and TPO stimulated the formation of colony-forming units of megakaryocyte in the presence of IL-3, but not alone, with similar maximum colony numbers for both cytokines. Our findings thus demonstrate that IL-11 principally stimulates megakaryocyte maturation rather than the proliferation of megakaryocytes, whereas TPO stimulates both.

Acetylcholinesterase↗
PubMed2001

A novel inhibitor of ceramide trafficking from the endoplasmic reticulum to the site of sphingomyelin synthesis.

Ceramide produced at the endoplasmic reticulum (ER) is transported to the lumen of the Golgi apparatus for conversion to sphingomyelin (SM). N-(3-Hydroxy-1-hydroxymethyl-3-phenylpropyl)dodecanamide (HPA-12) is a novel analog of ceramide. Metabolic labeling experiments showed that HPA-12 inhibits conversion of ceramide to SM, but not to glucosylceramide, in Chinese hamster ovary cells. Cultivation of cells with HPA-12 significantly reduced the content of SM. HPA-12 did not inhibit the activity of SM synthase. The inhibition of SM formation by HPA-12 was abrogated when the Golgi apparatus was made to merge with the ER by brefeldin A. Moreover, HPA-12 inhibited redistribution of a fluorescent analog of ceramide, N-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-d-erythro-sphingosine (C(5)-DMB-Cer), from intracellular membranes to the Golgi region. Among four stereoisomers of the drug, (1R,3S)-HPA-12, [corrected] which resembles natural ceramide stereochemically, was found to be the most active, although (1R,3S)-HPA-12 [corrected] did not affect ER-to-Golgi trafficking of protein. Interestingly, (1R,3S)-HPA-12 [corrected] inhibited conversion of ceramide to SM little in mutant cells defective in an ATP- and cytosol-dependent pathway of ceramide transport. These results indicated that (1R,3S)-HPA-12 [corrected] inhibits ceramide trafficking from the ER to the site of SM synthesis, possibly due to an antagonistic interaction with a ceramide-recognizing factor(s) involved in the ATP- and cytosol-dependent pathway.

Amides↗