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A Sakurai

Publications and source records attributed to A Sakurai.

At least 73 records · Page 4Linked to original sources
PubMed2000

Correlation of Glut-1 glucose transporter expression with.

Positron emission tomography (PET) with [18F]2-fluoro-2-deoxy-D-glucose (FDG) may show negative results for bronchioloalveolar lung carcinoma. We investigated the correlation of Glut-1 glucose transporter expression with [18F]FDG uptake in non-small cell lung cancer. Thirty-two patients with 34 non-small cell lung cancers (7 bronchioloalveolar carcinomas, 23 non-bronchioloalveolar adenocarcinomas, 3 squamous cell carcinomas, and 1 adenosquamous cell carcinoma) were studied. Final diagnoses were established by histology (via thoracotomy) in all patients. [18F]FDG PET was performed 40 min after i.v. injection of 185 MBq [18F]FDG. For semi-quantitative analysis of [18F]FDG uptake, standardized uptake values (SUVs) were calculated. Glut-1 expression was studied in terms of the immunohistochemistry of paraffin sections using anti-Glut-1 antibody to determine the intensity (0-3) of Glut-1 immunoreactivity and percentage of the Glut-1-positive area. Of seven bronchioloalveolar carcinomas, six (85.7%) were negative for the expression of Glut-1, while only one (4.3%) of 23 non-bronchioloalveolar adenocarcinomas was negative (P < 0.0001). The percentages of Glut-1-positive area, as well as the SUVs, were significantly lower in bronchioloalveolar carcinomas (n = 7) (2.86% +/- 7.56% and 1.25 +/- 0.75, respectively) than in non-bronchioloalveolar adenocarcinomas (n = 23) (54.83% +/- 25.64%, P < 0.0001, and 3.94 +/- 1.93, P = 0.001, respectively). The degree of cell differentiation correlated with the percentage of Glut-1-positive area and SUVs in adenocarcinoma of the lung. Correlations between SUVs and the intensity of Glut-1 immunoreactivity were also significant (intensities 0 and 1, n = 11, SUV 1.47 +/- 0.63; intensities 2 and 3, n=23, SUV 4.78 +/- 2.13; P < 0.0001). The percentage of Glut-1-positive area correlated significantly with SUVs (n = 34, r = 0.658, P < 0.01). Overexpression of Glut-1 correlated with high [18F]FDG uptake. These findings suggest that Glut-1 expression is related to [18F]FDG uptake in non-small cell lung cancer. Glut-1 expression, as well as [18F]FDG uptake, correlated with the degree of cell differentiation in adenocarcinomas, and both Glut-1 expression and [18F]FDG uptake were significantly lower in bronchioloalveolar carcinomas than in non-bronchioloalveolar carcinomas.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2000

[Surgical treatments for 7 pituitary adenomas in multiple endocrine neoplasia type 1].

We analyzed 7 pituitary adenomas in patients with multiple endocrine neoplasia type 1 (MEN1). Their incidence was 1.6% among 450 patients with pituitary adenomas which had been treated surgically in our department between 1978 and 1999. The age, gender, symptoms, type of hormone secretion, pathological and operative findings in the MEN1 patients were not apparently different from those in the non-MEN1 patients. Incidence of non-functioning pituitary adenomas, however, was more frequently encountered in our series than that in previous reports among Caucasian people. One patient who had 5 previous operations for the MEN tumors died following postoperative subarachnoid hemorrhage. Four of the seven patients presented initial symptoms related to pituitary adenomas and increased serum Ca level was retrospectively recognized in three of the four at the time of treatment for the pituitary adenomas.

Adenoma↗
PubMed1999

Regulatory role of metallothionein in NF-kappaB activation.

Metallothionein (MT), a low molecular weight, cysteine-rich metal binding protein, has been associated with cytoprotection from heavy metals and cellular oxidants. As MT has the ability to scavenge hydroxyl radicals, MT may control intracellular redox status. In the present study, we examined whether MT regulates the activity of nuclear factor-kappaB (NF-kappaB), which is one of the redox-regulated transcription factors, using the MT null embryonic cell lines established from MT null mice. We first found that tumor necrosis factor (TNF)-induced activation of the binding of NF-kappaB protein to DNA in wild type MT+/+ cells was lower than that in MT-/- cells. The NF-kappaB activation in MT-expressing cells established from MT-/- cells by the transfection of mouse MT-1 gene was also significantly lower than that in MT-/- cells. In addition, transfection of the MT gene inhibited TNF-induced IkappaB degradation and suppressed NF-kappaB-dependent gene expression induced by TNF. These results demonstrate that MT may function as a negative regulator of NF-kappaB activity.

Animals↗
PubMed1999

Fragmentation of the Golgi apparatus of Betz cells in patients with amyotrophic lateral sclerosis.

The Golgi apparatus (GA) of the large pyramidal motor neurons in the cerebral cortex (Betz cells), was examined in sixteen patients with sporadic amyotrophic lateral sclerosis (ALS), in one patient with familial ALS (FALS), and in ten non-ALS age matched controls including one patient with Huntington's disease and one patient with a brain infarct. The GA was immunostained with an antibody against the MG-160 protein, a conserved sialoglycoprotein of the medial cisternae of the organelle. In ALS, 13.2% of counted Betz cells had fragmented GA in contrast to 0.6% in the ten non-ALS controls. The fragmentation of the GA of Betz cells was identical to that previously reported in spinal cord motor neurons from patients with sporadic ALS and in transgenic mice expressing the G93A mutation of the gene encoding the Cu/Zn superoxide dismutase. The striking morphological similarity between the fragmentation of the GA observed in Betz cells and in spinal cord motor neurons suggests that a similar pathogenic mechanism is responsible for both, and that the fragmentation of the GA of the spinal cord motor neurons is not a consequence of deafferentation due to the degeneration of the Betz cells.

Adult↗
PubMed1999

Premature centromere division in patients with multiple endocrine neoplasia type 1.

Frequency of mitoses with premature centromere division (PCD) was examined in lymphocytes from subjects with multiple endocrine neoplasia type 1 (MEN 1). An increase in PCD after exposure to an alkylating agent was observed in subjects with MEN 1 who carry a heterozygous MEN1 gene mutation but not in normal controls or in affected subjects without the MEN1 gene mutation. These findings support the inclusion of MEN 1 as a chromosome instability syndrome and recognition of PCD as a manifestation of chromosome instability. Furthermore, these results suggest that the MEN1 gene product may function to maintain the integrity of DNA.

Adult↗
PubMed1999

Autosomally transmitted low concentration of thyroxine-binding globulin.

The gene coding for thyroxine-binding globulin (TBG) is located on the long arm of the X chromosome; thus anomalies of TBG are transmitted in an X-linked fashion. We report a family with decreased concentration of circulating TBG and an unusual pattern of inheritance. In this family, a number of members showed decreased levels of serum TBG. The unusual finding was that the low TBG was transmitted from the male proband to his son. Thyroxine (T4) binding affinity and heat lability of serum TBG of the proband was not different from values obtained from a normal control. All exons and the critical region in the upstream of the TBG gene were sequenced and no alterations were found. The mechanism that causes decreased concentration of TBG of the proband and family members is unknown, but an abnormality in transcription factors that are important for TBG gene expression might be considered.

Adult↗
PubMed1999

Fertilization, embryonic development, and offspring from mouse eggs injected with round spermatids combined with Ca2+ oscillation-inducing sperm factor.

Round spermatids, precursor male gametes, are known to possess the potential to achieve fertilization and embryonic development when injected into eggs. However, injection of spermatids alone seldom activates eggs in the mouse, as spermatids by themselves cannot induce an increase in intracellular Ca2+, a prerequisite for egg activation. We injected a mouse round spermatid into an egg simultaneously with partially purified sperm factor from differentiated hamster spermatozoa. The combined injection produced repetitive Ca2+ increases (Ca2+ oscillations) lasting for at least 4 h as observed at fertilization, and induced activation in 92% of eggs. This method provided 75% fertilization success associated with male and female pronucleus formation and development to 2-cell embryos, while only 7% of eggs were fertilized by injection of a spermatid alone. Of the 2-cell embryos, approximately 50% developed to blastocysts during 5 days of culture in vitro, while no blastocysts were obtained following injection of sperm factor alone. Furthermore, the 2-cell embryos, that were created by spermatids and sperm factor and transplanted into foster mothers, developed into normal offspring, although the percentage was only 22%. All infants grew into healthy adults carrying normal chromosomes. The sperm factor served as a complementary factor for successful fertilization by round spermatid injection.

Animals↗
PubMed1999

Arabidopsis det2 is defective in the conversion of (24R)-24-methylcholest-4-En-3-one to (24R)-24-methyl-5alpha-cholestan-3-one in brassinosteroid biosynthesis.

Previously, we have shown that the Arabidopsis det2 (deetiolated2) mutant is defective in the biosynthesis of brassinosteroids (BR) and that DET2 (a steroid 5alpha-reductase) acts early in the proposed BR biosynthetic pathway. In this paper we present further biochemical characterization of det2. We have undertaken metabolic experiments with 2H-labeled substrates of intermediates involved in the formation of campestanol from campesterol, and quantitative analysis of intermediates in Arabidopsis wild type and det2. The results of these studies indicate the early operating steps of BR biosynthesis as: campesterol --> 4-en-3beta-ol --> 4-en-3-one --> 3-one --> campestanol in Arabidopsis, with det2 deficient in the conversion of 4-en-3-one to 3-one. We have also detected these intermediates in the formation of campestanol from campesterol and their metabolic conversions using cultured cells of Catharanthus roseus. These studies confirmed the biosynthetic sequence of events from campesterol to campestanol as was found in Arabidopsis. As such, the originally proposed biosynthetic pathway should be modified.

Arabidopsis↗
PubMed1999

Association of a cellular 21-kDa transmembrane protein (VAP21) with enveloped viruses.

We reported previously that the rabies virions contained a 21-kDa cellular transmembrane protein (referred to as VAP21) as a minor component (Sagara, J. et al, Microbiol. Immunol. 41(12): 947-955, 1997). In this study, we further examined the possible interactions of VAP21 with other enveloped viruses, including the vesicular stomatitis virus (VSV; negative-stranded RNA virus), Sindbis virus (positive-stranded RNA virus) and herpes simplex virus type 1 (HSV-1; double-stranded DNA virus). An immunoblot analysis demonstrated that all of these enveloped viruses contained VAP21 in the virion as a minor component. Immunoprecipitation studies suggested that VAP21 was associated with certain viral proteins in the cell, such as the matrix (M) protein of VSV, a capsid protein of Sindbis virus, and at least a capsid protein (VP5) of HSV-1. The association was disrupted by treatment with 0.5% sodium dodecyl sulfate, but resistant to the treatment with 1% NP-40 plus 1% deoxycholate. These results suggest that: 1) VAP21 is not primarily associated with the viral transmembrane glycoprotein but rather with the internal viral protein, and, 2) this association would cause the efficient incorporation of VAP21 into the virion.

Cells, Cultured↗
PubMed1999

Characterization of the MEN1 gene product, menin, by site-specific polyclonal antibodies.

The gene associated with multiple endocrine neoplasia type 1 (MEN 1), designated MEN1, has recently been identified. This gene shows no homology to other known genes, and its expression is not restricted to endocrine organs as estimated by northern blotting. Expression of the MEN1 gene product, menin, has been studied only in a few tissues. In this report, expression of menin in various cells and mouse tissues was studied using two polyclonal antibodies against menin. Expression of menin as a 76 kDa single protein was observed in all cell lines examined, regardless of origin. Two nuclear localization signals of the menin have been reported, but through the study of mutant menin in lymphocytes from subjects with MEN 1, impaired nuclear localization of the mutant menin was observed even though the mutant retained one of the two nuclear localization signals (NLSs). Menin was stable in vitro with a half-life of over 24 h at 37 degrees C. In the cell, the half-life of wild-type menin was about 10 h, while that of the mutant was about 2 h. The mutant rapidly disappeared from the nucleus.

Animals↗
PubMed1999

[Gonorrhea].

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Gonorrhea↗
PubMed1998

Novel V184E MEN1 germline mutation in a Japanese kindred with familial hyperparathyroidism.

We studied the MEN1 gene in a kindred where three patients (the proposita and two of her sons) were affected with hyperparathyroidism. By polymerase chain reaction (PCR)-based direct sequencing of 10 exons of MEN1, a novel germline mutation was identified in the proposita. This mutation, a T-to-A transition at codon 184 in exon 3, predicts an amino acid change from valine to glutamine (V184E). PCR-single-strand conformational polymorphism (PCR-SSCP) analysis of exon 3 followed by sequencing showed the same mutation in the two sons, and in two clinically normal granddaughters of an affected son. Since the T-to-A substitution segregated with the disorder in the kindred except for the granddaughters and it was not detected in 100 alleles from 50 normal individuals, the change observed in MEN1 is not a polymorphism, but causes familial hyperparathyroidism. Thus the two grandchildren with the mutation were diagnosed as presymptomatic carriers.

Adolescent↗
PubMed1998

Glutamatergic neuromuscular transmission in the heart of the isopod crustacean Ligia exotica.

Neuromuscular transmission between the cardiac ganglion (CG) and the myocardium was examined in the adult heart of the isopod crustacean Ligia exotica. Intracellular injection of neurobiotin into the CG neurones revealed that all six CG neurones send their axons onto the cardiac muscle, where they form axon terminals bearing varicosities. All the CG neurones and their processes exhibited glutamate-like immunoreactivity. The cardiac muscle showed depolarizing membrane potential responses to glutamate applied focally to sites close to axon terminals bearing varicosities. Both the glutamate-induced response and the excitatory junctional potential (EJP) showed desensitization in response to the repeated application of glutamate. Under voltage-clamp conditions, the cardiac muscle produced inward current responses to focally applied glutamate. The reversal potential for the glutamate-induced current estimated from extrapolation of the linear current/voltage relationship was similar to that of the excitatory junctional current evoked by ganglionic nerve stimulation. Both the glutamate-induced response and the EJP were blocked by a glutamate-specific antagonist, Joro spider toxin. These results led us to conclude that the CG neurones of Ligia exotica are glutamatergic motoneurones.

Journal Article↗
PubMed1998

Novel MEN1 gene mutations in familial multiple endocrine neoplasia type 1.

The recent isolation of the gene responsible for multiple endocrine neoplasia type 1 (MEN 1) has enabled direct genetic diagnosis for people with endocrine tumors and family members of affected patients. Although MEN 1 is rarely recognized in the Japanese population compared to its prevalence in Caucasians, we have previously reported a high prevalence of this disease in a limited area (Nagano Prefecture; population, 2.15 million). In this communication, we report mutations of the MEN1 gene in kindreds living in Nagano Prefecture. The absence of a common mutation among these kindreds indicates that the high prevalence of MEN 1 in this area is not due to a regional accumulation of patients descended from a common ancestor. This result implies that the prevalence of MEN 1 in other areas of Japan could also be higher than had been thought.

Frameshift Mutation↗
PubMed1998

Transcription of the Arabidopsis CPD gene, encoding a steroidogenic cytochrome P450, is negatively controlled by brassinosteroids.

The Arabidopsis CPD gene encodes a cytochrome P450 steroid side-chain hydroxylase (CYP90) that plays an essential role in the biosynthesis of the plant hormone brassinolide. Expression of the CPD gene is confined to cotyledons and leaf primordia in etiolated seedlings and detectable in the adaxial parenchyma of expanding leaves in light-grown plants. Transcription of the CPD gene is not affected by the plant growth factors auxin, ethylene, gibberellin, cytokinin, jasmonic acid and salicylic acid, but is specifically down-regulated by brassinolide in both dark and light. Steady-state mRNA levels of a CPD promoter-driven uidA reporter gene correlate with the expression of resident CPD gene in transgenic plants. Intermediates of the early and late C-6 oxidation pathways of brassinolide, carrying C-22 and C-23 side-chain hydroxyls, efficiently inhibit the activity of the CPD promoter. Repression of CPD transcription by brassinosteroids is sensitive to the protein synthesis inhibitor cycloheximide, indicating a requirement for de novo synthesis of a regulatory factor.

Arabidopsis↗
PubMed1998

Reconstruction of skull defects with vascularized omentum transfer and split calvarial bone graft: two case reports.

Autogenous calvarial bone grafts have been widely used in craniofacial reconstruction following trauma, congenital anomalies, and head and neck tumors. In cases of late restoration of a collapsed cranial vault, an extradural dead space is occasionally observed which might cause infection and grafted bone absorption. The combined use of a split calvarial bone graft and an omental flap has been an effective technique for treating complicated cranial defects. The omental flap eliminates the extradural dead space between the grafted calvarial bone and the scarred dura, and provides an acceptable vascular bed for grafted bone. The authors report this technique for complex cranioplasties in two cases, with good cosmetic results.

Aged↗