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T Kameya

Publications and source records attributed to T Kameya.

At least 73 records · Page 4Linked to original sources
PubMed1997

Maintenance of chloroplast-derived sequences in the mitochondrial DNA of Gramineae.

Evidence for the transfer of DNA from the chloroplast to the mitochondrion has been reported in many higher plants and, in most cases, the transferred chloroplast genes do not have the ability to encode functional products as a consequence of base substitutions and/or multiple rearrangements. We reported previously that the sequence of one end of a chloroplast-derived (ct-derived) fragment of DNA that contained the rps19 and trnH genes has been maintained in most gramineous plants and that its presence seems to be correlated with gene expression in this region. In the present study, we have investigated whether or not the ct-derived sequences in mitochondrial DNA (mtDNA) from some gramineous plants and species of Oryza are conserved, and whether or not such conservation is related to gene expression in these regions. We identified two junctions between ct-derived and mitochondrial sequences that were conserved among some gramineous plants. Around these regions, we found a ct-derived gene for tRNA and the promoter of a mitochondrial gene on the ct-derived sequences, respectively, and these regions were transcribed through the junctions. This result indicates that the junctions and/or regions that are transcribed and functional in mitochondria have been strongly conserved and maintained during their evolution. In Oryza, some junctions between ct-derived and mitochondrial sequences were conserved and other junctions were not. These variations seem to have been caused by deletions and/or rearrangements, and appear to be specific to the type of genome. In the case of Oryza, the timing of deletions and/or rearrangements of ct-derived sequences is likely to have coincided with the divergence of the various genome types.

Base Sequence↗
PubMed1997

Expression of nm23 protein in pulmonary adenocarcinomas: inverse 1orrelation to tumor progression.

Immunohistochemical assessment was made of nm23 protein expression in pulmonary adenocarcinoma. Of the 147 adenocarcinomas 67% (99/147) were weakly and 33% (48/147) strongly positive for nm23 protein. nm23 protein expression in primary tumors was shown to correlate inversely with advancing pathologic stage and the degree of metastasis in regional lymph nodes (P < 0.05). The staining of tumors without nodal metastasis was more intense than with nodal metastasis (P < 0.02). Nodal metastasis was seen in 37% (55/147) cases examined. The immunoreactivity to nm23 protein in tumor cells of nodal metastasis was essentially the same as in those of primary tumors (P < 0.01). Significant correlation between patient prognosis and immunoreactivity for nm23 in primary tumors (P < 0.05) was demonstrated. But none could be found between immunoreactivity and other parameters such as histologic grading, distant metastasis, tumor size or disease-free survival. Neither was there any significant correlation between pathologic parameters examined and the expression of nm23 in any histologic subtype. Multivariate analysis using Cox's proportional hazards regression model with five variables indicated nm23 and lymph node metastasis to contribute to overall patient survival. Based on risk ratio disadvantageous state/advantageous states, the gravity of prognostic factors was assessed for lymph node metastasis as 9.25, nm23 expression as 2.06, distant metastasis as 1.23, pathologic stage as 0.78 and tumor size as 0.77. The results suggested that in pulmonary adenocarcinoma a reduced expression of nm23 protein was associated with lymph node metastasis and poor patient survival.

Adenocarcinoma↗
PubMed1997

A chloroplast derived trnH gene is expressed in the mitochondrial genome of gramineous plants.

We reported previously that the mitochondrial sequence that contains the chloroplast-derived trnH gene has been highly conserved in the region around one terminus of the junction between chloroplast-derived and mitochondrion-specific sequences in most of the gramineous plants analyzed [15]. The results of RT-PCR, northern hybridization, in vitro capping and ribonuclease protection experiments show that the chloroplast-derived trnH gene is transcribed from a putative promoter that is located in the mitochondrion-specific sequence. Gene expression in this region seems to be correlated with the conservation of the sequence at the junction between the chloroplast-derived fragment and the mitochondrion-specific sequence.

Base Sequence↗
PubMed1997

Germline mutations of the MEN1 gene in Japanese kindred with multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant familial cancer syndrome. The responsible gene MEN1 has recently been isolated, and its germline mutations have been identified in affected individuals in the United States, Canada and Europe. We screened for MEN1 mutations by direct nucleotide sequencing of all protein-coding regions, and identified five distinct germline mutations in five among six Japanese kindreds with familial MEN1 or familial hyperparathyroidism. The mutations were dispersed across the gene. These findings suggest that, because of the absence of an obvious founder effect, the entire MEN1 gene region should be examined for germline mutations in the probands of MEN1 and related syndromes in Japanese families.

DNA, Neoplasm↗
PubMed1997

Analysis of apoptosis morphology in Epstein-Barr virus positive and negative Burkitt's lymphoma cells.

UNLABELLED: In recent studies of cycloheximide (CHX)-induced apoptosis in sublines of established Burkitt's lymphoma cell lines (BJA-B) both with and without Epstein-Barr virus (EBV) infection, we noticed two distinct types of apoptosis morphology. In the present paper, we have classified these, and further carried out a statistical analysis of their incidence in untreated and CHX-treated EBV-free (EBV(-)) and EBV-infected (EBV(+)) BJA-B cells. CLASSIFICATION: Both types of apoptosis morphology demonstrated typical nuclear and cytoplasmic condensation. However, "Type 1 apoptotic cells" (AP1) maintained a spherical or ovoid shape, but "Type 2 apoptotic cells" (AP2) were typified by the lobulation of their nuclear and cytoplasmic structures to form "clover leaf" shapes. Statistical analysis of incidence: The numbers of AP1 and AP2 cells were analysed using a chi 2 test, with results as follows: EBV(-) cells underwent AP1 in preference to AP2 (90.5% versus 9.5%) (p < 0.001), whilst EBV(+) cells had comparably more AP2, making AP1 and AP2 approximately equal (49.3% versus 50.7%) (p > 0.1). In EBV(-) cells, treatment with CHX had little effect on the ratios of differing apoptotic morphology. In contrast, in the EBV(+) cells, cell death was altered from AP2 (50.7%-->25.2%) towards AP1(49.3%-->74.8%) (p < 0.001). We propose that cellular proteins known to be associated with EBV infection not only protect the cells from apoptosis, but also affect the phenotype of apoptosis. This knowledge may be useful for defining possible mechanisms of apoptosis induction and/or inhibition in specific models.

Apoptosis↗
PubMed1996

Pituitary choristoma composed of corticotrophs and adrenocortical cells in the sella turcica.

A pituitary tumour composed of well-differentiated corticotrophs and adrenocortical cells is reported. Sections of the tumour revealed a mixture of small round cells with amphophilic or basophilic periodic acid-Schiff (PAS)-positive cytoplasm and large spherical and oval cells with abundant, granular, partly vacuolated PAS-negative cytoplasm. The small cells contained type 1 cytokeratin-positive microfilaments, numerous 250-500 nm endocrine-type secretory granules immunoreactive for adenocorticotropic hormone (ACTH) and beta-lipotropin. The large cells possessed ample cytoplasm filled with abundant vesicular smooth endoplasmic reticulum, numerous mitochondria possessing tubulovesicular cristae and frequent dense bodies. They lacked the features of pituitary endocrine cells or folliculostellate cells and were found to contain a panel of steroidogenic dehydrogenases and hydroxylases. The tumour was classified as a choristoma, in which two distinct cells types, corticotrophs and adrenocortical cells, were mixed. We suggest that, under continued ACTH stimulation, umcommitted stem cells may differentiate into adrenocortical cells. Alternatively, the presence of adrenocortical cells may be the result of heterotopia.

Adolescent↗
PubMed1996

Analysis of CAG trinucleotide expansion associated with Machado-Joseph disease.

There are currently some types of autosomal dominant cerebellar ataxias such as Machado-Joseph disease (MJD), spinocerebellar ataxia types 1-5 (SCA1-5), or hereditary dentatorubropallidoluysian atrophy. It is very important for these ataxias to be clinically differentiated, but that is sometimes difficult. In particular, the differential diagnosis between MJD and SCA1 is thought to be the most difficult. Recently, both MJD and SCA1 have been proven to be related to expansions of CAG trinucleotide in their causative genes. In this study, 20 cases of MJD in 13 unrelated Japanese families were genetically and clinically examined in comparison with 20 cases of age at onset- and duration-matched Japanese SCA1. The CAG repeat number of expanded MJD and SCA1 alleles was 72.2 +/- 3.1 (mean +/- SD, n = 20) and 47.3 +/- 4.4 (n = 20), respectively, and each repeat size was inversely correlated with age at onset in both MJD and SCA1. The repeat number in leukocytes increased from parents to children with acceleration of age at onset (anticipation) in MJD. In MJD, the number of CAG repeats in the expanded allele was lower in sperm than that of leukocytes, but was more in SCA1. However, the number of peaks in the expanded allele was greater in sperm than in leukocytes in both MJD and SCA1 (increased mosaicism level). MJD was clinically characterized by a relatively higher frequency of ocular signs such as eyelid retraction, bulging eyes, ophthalmoparesis, and nystagmus, spasticity in lower limbs, and sensory and urinary disturbances in contrast to the SCA1 patients except for slow eye movement. These results indicate that the expanded CAG repeat and clinical features are correlated in both MJD and SCA1, and MJD can be differentiated from SCA1 by clinical characteristics mentioned above as well as DNA analysis.

Adolescent↗
PubMed1996

Expression of BCL-2 gene product in embryonal tumors of the central nervous system.

BACKGROUND: The expression of bcl-2 is associated with suppression of programmed cell death and prolonged cell survival. Recently, immunoreactivity to the bcl-2 gene product has been reported not only in a variety of embryonal and adult nonhematopoietic tissues, but also in neuroblastoma. However, the study of bcl-2 expression has not been performed in brain tumors. METHODS: In this study, we examined the incidence and significance of bcl-2 expression in 25 cases of embryonal tumors of the central nervous system, including medulloblastoma, neuroblastoma, ependymoblastoma, and PNET (primitive neuroectodermal tumor), which has the possibility of neuronal differentiation. RESULTS: The results demonstrated that 13 tumors (52%) positive for bcl-2 belonged to early differentiated and neuronal types, and 7 negative tumors (28.0%) mostly belonged to undifferentiated type. CONCLUSIONS: These results have led us to speculate on the possibility that tumor cells begin expressing bcl-2 along with their neuronal differentiation from primitive cells.

Adolescent↗
PubMed1996

A reproducible assay of polymerase chain reaction to detect trinucleotide repeat expansion of Huntington's disease and senile chorea.

A simple and reproducible method of polymerase chain reaction (PCR) assay was established to detect trinucleotide repeat expansion for Huntington's disease (HD) using a new DNA polymerase and buffer system. The system consists of an extremely heat stable DNA polymerase (Pfu), and a buffer supplemented with ammonium sulfate and dimethyl sulfoxide. Previous methods to amplify expanded alleles for HD have been very complex in PCR conditions, but the reproducibility was sometimes very low because of repetitive sequences around the primer sequences. With the present method, strong bands for the disease alleles were reproducibly visible in a conventional agarose gel stained with ethidium bromide without using isotopes. Three cases with sporadic HD and a case with senile chorea showed expanded alleles for HD with smaller sizes of the expansion than cases with typical HD. These results showed that the present method provides a simple and reproducible way to detect HD allele, and some cases with sporadic HD and senile chorea had expanded HD alleles.

Adult↗
PubMed1996

Cool-temperature-induced chlorosis in rice plants.

We have established an experimental system for mimicking the phenomenon of cool-temperature-induced chlorosis (CTIC) in rice plants (Oryza sativa L.). Rice seedlings were initially grown in darkness under cool-temperature conditions and then exposed to light and warm conditions to follow the expression of CTIC. Induction of CTIC in the sensitive cultivar (cv Surjamukhi) was bimodally dependent on the temperatures experienced during the initial growth in darkness. CTIC was maximally induced between 15 and 17 degrees C. A positive correlation was demonstrated between induction of CTIC and the growth activity of shoots during growth in darkness. Electrophoretic and immunoblot analysis revealed that accumulation of NADPH-protochlorophyllide oxidoreductase in plastids was also bimodally dependent on the temperatures during the growth in darkness with minimum accumulation between 15 and 17 degrees C, suggesting that the reduction of NADPH-protochlorophyllide oxidoreductase accumulation in plastids might be closely linked to a disturbance in transformations of plastids to etioplasts during the dark growth under the critical temperatures and thereby to the CTIC phenomenon. This was corroborated by electron microscopic observations. These results suggest that growth is one of the determining factors for the expression of CTIC phenotype in rice under cool temperature.

Amino Acid Sequence↗
PubMed1996

Reduction of CAG expansions in cerebellar cortex and spinal cord of DRPLA.

Recent studies have identified an unstable expansion of a CAG repeat in a gene located on chromosome 12 as a cause of dentatorubropallidoluysian atrophy (DRPLA). To investigate whether the somatic heterogeneity may relate to the selective neuronal damage caused by the disease, genomic DNA from various tissues of an autopsied patient with DRPLA was examined to compare possible variations of expanded CAG repeats for the disease. Although the size of the expanded CAG repeat from many organs was almost the same as that from peripheral lymphocytes, those from cerebellar cortex and spinal cord were unexpectedly reduced and numbers of peaks within an expanded allele were relatively strict. These results suggest that the CAG repeat is not simply expanded in the genome of the tissues that are most involved in DRPLA, but that another mechanism might be responsible for the specific neuronal death.

Adult↗
PubMed1996

[A case of solitary metastasis from renal cell carcinoma to the thyroid gland].

A case of solitary metastasis with renal cell carcinoma to the thyroid gland is presented. The patient was a 54-year-old man found to have an abnormal mass in the neck. He had a past history of radical nephrectomy orignating from the right renal cell carcinoma 5 years earlier (pT2N0M0, G2 > 3, alveolar type, clear cell subtype). Ultrasonography revealed a tumor mass in the right hemithyroid gland. Right hemithyroidectomy was performed on April 19, 1995. Histopathologically, the removed thyroid tumor showed clear cell carcinoma. The possibility of a primary thyroid tumor was ruled out by immunohistochemical thyroglobulin staining, and the present case was thus diagnosed as of metastatic thyroid tumor of renal cell carcinoma. The present case is the 12th case of thyroid solitary metastasis of renal cell carcinoma reported in Japan to date.

Carcinoma, Renal Cell↗
PubMed1996

Bcl-2 protein expression in lung cancer and close correlation with neuroendocrine differentiation.

For determination of the cellular distribution of bcl-2 expression in lung cancer and clarification of its correlation with cell neuroendocrine differentiation, Bcl-2 immunostaining was carried out on a large series of formalin-fixed, paraffin-embedded lung cancer samples, and four general neuroendocrine marker and seven peptide hormone stainings were carried out on all Bcl-2-positive squamous cell carcinomas and adenocarcinomas of the lung as well as on 8 pulmonary neuroendocrine carcinomas histologically diagnosed. In addition, 3 small cell lung cancer cell lines were studied by Western blotting. Neuroendocrine differentiation in Bcl-2-negative squamous cell carcinomas and adenocarcinomas was examined with chromogranin A and alpha-subunit of Go protein stainings. Bcl-2 protein was detected in 104/111 small cell carcinomas, 8/8 neuroendocrine carcinomas, 0/6 typical (well differentiated) carcinoids, 23/64 squamous cell carcinomas, 4/65 adenocarcinomas, and all 3 small cell lung cancer cell lines. All 8 neuroendocrine carcinomas, 11 of the Bcl-2-positive squamous cell carcinomas, and all 4 Bcl-2 positive adenocarcinomas expressed multiple neuroendocrine markers. The distributions of Bcl-2 and neuroendocrine marker immunoreactivity closely paralleled each other on consecutive sections. In squamous cell carcinomas, Bcl-2-positive cells could be roughly subdivided into those with neuroendocrine differentiation features, usually demonstrating intense Bcl-2 staining, with basaloid tumor cells usually expressing weak to moderate Bcl-2 staining. The present study clearly shows Bcl-2 protein expression to be remarkably differentially regulated according to histological types of lung cancers and to appear to quite likely be closely associated with neuroendocrine differentiation of tumor cells, indicating that bcl-2 is importantly involved in cell development and differentiation, in addition to protecting cells from apoptosis. Bcl-2 might be usable as a neuroendocrine marker in lung cancers and possibly also in neural-crest-derived tumors.

Adenocarcinoma↗
PubMed1996

Palisades in cerebral astrocytoma simulating the so-called polar spongioblastoma: a histological, immunohistochemical, and electron microscopical study of an adult case.

This report concerns a case of fibrous astrocytoma with palisade features that mimics a polar spongioblastoma. The patient was a 54-year-old female who presented with a tumor of the frontal lobe. The presence of neurites, with or without synaptic devices were considered to represent the entrapment by the tumors of the pre-existing neurons and their processes.

Astrocytoma↗
PubMed1995

Biodegradation ranks of priority organic compounds under anaerobic conditions.

The biodegradations of 52 priority organic compounds were evaluated under anaerobic conditions by two tests developed in a preceding paper (Urano et al., 1995). Namely, the biodegradabilities of the compounds were classified into 13 ranks by the method proposed by Urano et al. (1995). Most of the aliphatic alcohols and carboxylic acids were not inhibitory and were biodegraded, but the compounds having ether bonds or branched hydrocarbon groups were biodegraded slowly. Aliphatic aldehyde and amines were not so much inhibitory but were hardly biodegraded. The benzene substitutes having groups of -CH2OH, -CHO, -CH2CH(NH2)COOH, -COOH and -OH were easily biodegraded, but the compounds having groups of -NO2, -NH2 and -SO3H were hardly biodegraded. Most of the nitro compounds were inhibitory in the higher concentration test though they were reduced into amino compounds. Since the biodegradation characteristics of many organic compounds could be classified and discussed appropriately, the suitability of the proposed method is substantiated.

Anaerobiosis↗
PubMed1995

Testing and classification methods for the biodegradabilities of organic compounds under anaerobic conditions.

Biodegradability is one of the most important characteristics of an organic compound for predicting its fate and life in the environment and its application in biological wastewater treatment. But there is no general testing method for biodegradability under anaerobic conditions. The biodegradabilities of thirteen principal organic compounds was investigated in a batch test using vials under various conditions, such as the concentration of an organic compound, the cultivation method and the concentration of anaerobic bacteria for seeding. Two test methods in the standard concentration and the low concentration were developed. A new method to classify the biodegradabilities of organic compounds into thirteen ranks was proposed by considering inhibition, complete biodegradation and first step biodegradation.

Bacteria, Anaerobic↗