Biomedical subjects
Publications and source records attributed to H Fukuzawa.
A case of aqueduct stenosis in an adult with several depressive episodes and the clinical features of delusional depression is presented. The patient complained of a strange feeling in the throat. She also had had several falls with loss of consciousness. The relationship between aqueduct stenosis and diencephalic dysfunction is discussed.
cDNA clones for the periplasmic carbonic anhydrase (CA; carbonate hydro-lyase, EC 4.2.1.1) of Chlamydomonas reinhardtii cells were isolated and characterized. The fact that the cloned cDNA fragments encoded a 377-amino acid polypeptide (41,626 Da) consisting of an NH2-terminal hydrophobic signal peptide of 20 amino acids, a large (35,603 Da) subunit polypeptide, and a small (4144 Da) subunit polypeptide indicates that the two subunits are cotranslated as a precursor polypeptide. The amino acid sequence of mature subunits deduced from the nucleotide sequence showed 20-22% homology with human CA isozymes (CAI, CAII, and CAIII). Three zinc-liganded histidine residues and those forming a hydrogen-bond network to zinc-bound solvent molecules were highly conserved in the plant and animal enzymes. Three possible asparagine-linked glycosylation sites were found in the large subunit. Northern blot analysis was carried out using the cDNA fragment as a probe. The level of 2.0-kilobase CA mRNA increased within 1 hr when CO2 concentration of the bubbling gas was changed from 5% to 0.04% (air level) in the presence of light. On the other hand, CA mRNA did not accumulate when CO2 concentration was lowered in the dark. Experiments using 3-(3,4-dichlorophenyl)-1,1-dimethylurea showed that photosynthesis is absolutely required for the accumulation of CA mRNA. These results indicate that CA biosynthesis is regulated by changes in environmental CO2 concentration as well as light at the level of mRNA abundance.
Two copies of structurally related genes (CAH1 and CAH2) for carbonic anhydrase (EC 4.2.1.1) were found to be tandemly clustered on the Chlamydomonas reinhardtii genome. The previously isolated cDNA clones for carbonic anhydrase polypeptides were derived from the upstream gene, CAH1, which has 10 introns in its coding region. The downstream gene, CAH2, also has 10 introns, at positions identical to those of CAH1. Although amino acid sequences deduced from the two genes showed 91.8% identity, partial sequences of the authentic enzyme isolated from air-induced cells were identical only to those of the CAH1 product. Northern hybridization using gene-specific probes showed that the level of 2.0-kilobase CAH1 mRNA increased in response to a decrease in CO2 concentration in the presence of light. The CAH1 mRNA did not accumulate when CO2 was lowered in the dark. In contrast, the level of 2.0-kilobase CAH2 mRNA decreased in response to lowering of CO2 and increased upon transfer to the high-CO2 condition in light. The decrease of CAH2 mRNA under the low-CO2 condition was not observed in the dark. The fully induced mRNA level was much higher for CAH1 than for CAH2. These results indicate that CAH1 is a gene coding for the major periplasmic carbonic anhydrase whose level of transcript is rapidly induced under the low-CO2 condition in the presence of light, and that CAH2 may encode another periplasmic isozyme, which is made under the high-CO2 condition.
The effect of external inorganic carbon concentration and light on carbonic anhydrase (CA) protein accumulation and steady-state mRNA levels were examined in Chlamydomonas reinhardtii. When photoautotrophically grown high-CO(2) cells were transferred to low-CO(2) conditions, they exhibited a significant accumulation of the 2.0-kilobase CA transcript after 1 hour with the maximum level reached after 2 hours. An increase in the accumulation of the 37-kilodalton CA monomer was observed after 2-hour exposure to air. Cells allowed to adapt to air levels of CO(2) in the dark showed neither an increase in CA mRNA abundance nor in the accumulation of the enzyme. Similarly, addition of 10 micromole 3-(3,4-dichlorophenyl)-1, 1-dimethylurea immediately after transferring high-CO(2) cells to low-CO(2) condition did not cause an increase in CA transcript abundance and enzyme accumulation, suggesting that photosynthesis is absolutely required in the regulation of CA transcript abundance. In addition to the photosynthesis-dependent process, a blue light stimulated mechanism is also involved in CA transcript regulation. Experiments with transcription inhibitors confirmed the notion that the gene for carbonic anhydrase enzyme is encoded by the nuclear genome and that the induction of the enzyme depends heavily on the transcription of the CA gene.
Forty biological units of Kallikrein were administered intramuscularly to nine persons suffering from multi-infarct dementia. With automatic analysis equipment, the wave-form recognition method was used to analyze EEG before injection, immediately after injection, and 30, 60, 90, and 120 minutes after injection. The results of analysis done the five times after injection were then compared with the analysis results before injection. With the passage of time after injection, delta and theta waves showed a gradually decreasing tendency, while alpha and beta waves showed a gradual increase. It was inferred that these changes in the EEG were caused by an increase in the flow of cerebral blood, which in turn was the effect of the dilatation of cerebral blood vessels resulting from the action of the Kallikrein.
We have determined the complete nucleotide sequence of chloroplast DNA from a liverwort, Marchantia polymorpha, using a clone bank of chloroplast DNA fragments. The circular genome consists of 121,024 base-pairs and includes two large inverted repeats (IRA and IRB, each 10,058 base-pairs), a large single-copy region (LSC, 81,095 base-pairs), and a small single-copy region (SSC, 19,813 base-pairs). The nucleotide sequence was analysed with a computer to deduce the entire gene organization, assuming the universal genetic code and the presence of introns in the coding sequences. We detected 136 possible genes. 103 gene products of which are related to known stable RNA or protein molecules. Stable RNA genes for four species of ribosomal RNA and 32 species of tRNA were located, although one of the tRNA genes may be defective. Twenty genes encoding polypeptides involved in photosynthesis and electron transport were identified by comparison with known chloroplast genes. Twenty-five open reading frames (ORFs) show structural similarities to Escherichia coli RNA polymerase subunits, 19 ribosomal proteins and two related proteins. Seven ORFs are comparable with human mitochondrial NADH dehydrogenase genes. A computer-aided homology search predicted possible chloroplast homologues of bacterial proteins; two ORFs for bacterial 4Fe-4S-type ferredoxin, two for distinct subunits of a protein-dependent transport system, one ORF for a component of nitrogenase, and one for an antenna protein of a light-harvesting complex. The other 33 ORFs, consisting of 29 to 2136 codons, remain to be identified, but some of them seem to be conserved in evolution. Detailed information on gene identification is presented in the accompanying papers. We postulated that there were 22 introns in 20 genes (8 tRNA genes and 12 ORFs), which may be classified into the groups I and II found in fungal mitochondrial genes. The structural gene for ribosomal protein S12 is trans-split on the opposite DNA strand. The universal genetic code was confirmed by the substitution pattern of simultaneous codons, and by possible codon recognition of the chloroplast-encoded tRNA molecules, assuming no importation of tRNA molecules from the cytoplasm. The nucleotide residue A or T is preferred at the third position of the codons (G+C, 11.9%) and in intergenic spacers (G+C, 19.5%), resulting in an overall G+C content that is low (28.8%) throughout the liverwort chloroplast genome. Possible gene expression signals such as promoters and terminators for transcription, predicted locations of gene products, and DNA replicative origins are discussed.
The nucleotide sequence (56,410 base-pairs) of the large single-copy region of chloroplast DNA from the liverwort Marchantia polymorpha has been determined. The sequence starts from one end (JLA) of the large single-copy region and encompasses genes for 21 tRNAs, six ATPase subunits (atpA, atpB, atpE, atpF, atpH and atpI), two photosystem I polypeptides (psaA and psaB), four photosystem II polypeptides (psbA, psbC, psbD and psbG), five ribosomal proteins (rps2, rps4, rps7, rps'12 and rps14), and three RNA polymerase subunits (rpoB, rpoC1 and rpoC2). In addition, we detected 18 open reading frames ranging from 29 to 2136 amino acid residues long, four of which share significant amino acid sequence homology to those of an Escherichia coli malK protein (designated mbpX), human mitochondrial ND2 (ndh2) and ND3 (ndh3) of a respiratory chain NADH dehydrogenase, or a bacterial antenna protein of a light-harvesting complex (lhcA). Sequence analysis suggests that four tRNA genes and six protein genes might be split by introns; they are trnG(UCC), trnK(UUU), trnL(UAA), trnV(UAC), atpF, ndh2, rpoC1, rps'12, ORF135 and ORF167. In the large single-copy region described here, the gene organization deduced is highly conserved with respect to that of higher plants, but an inversion of some 30,000 base-pairs flanked by trnL(CAA) and trnD(GUC) was seen between the liverwort and tobacco chloroplast genomes.
The nucleotide sequence (25,320 base-pairs) of a part of the large single-copy region of chloroplast DNA from the liverwort Marchantia polymorpha was determined. This region encodes putative genes for four tRNAs, isoleucine tRNA(CAU), arginine tRNA(CCG), proline tRNA(UGG) and tryptophan tRNA(CCA); eight photosynthetic polypeptides, the large subunit of ribulose bisphosphate carboxylase/oxygenase (rbcL), 51,000 Mr photosystem II chlorophyll alpha apoprotein (psbB), apocytochrome b-559 polypeptides (psbE and psbF), 10,000 Mr phosphoprotein (psbH), cytochrome f preprotein (petA), cytochrome b6 polypeptide (petB), and cytochrome b6/f complex subunit 4 polypeptide (petD); 13 ribosomal proteins (L2, L14, L16, L20, L22, L23, L33, S3, S8, S11, S12, S18 and S19); initiation factor 1 (infA); ribosome-associating polypeptide (secX); and alpha subunit of RNA polymerase (rpoA). Functionally related genes were located in several clusters in this region of the genome. There were two ribosomal protein gene clusters: rpl23-rpl2-rps19-rpl22-rps3-rpl16-+ ++rpl14-rps8-infA-secX-rps11-rpoA, with a gene arrangement similar to that of the Escherichia coli S10-spc-alpha operons, and the rps12'-rpl20-rps18-rpl33 cluster. There were gene clusters encoding photosynthesis components such as the psbB-psbH-petB-petD and the psbE-psbF clusters. Thirteen open reading frames, ranging in length from 31 to 434 amino acid residues, remain to be identified.
We characterized the genes in the regions of large inverted repeats (IRA and IRB, 10,058 base-pairs each) and a small single copy (SSC 19,813 bp) of chloroplast DNA from Marchantia polymorpha. The inverted repeat (IR) regions contain genes for four ribosomal RNAs (16 S, 23 S, 4.5 S and 5 S rRNAs) and five transfer RNAs (valine tRNA(GAC), isoleucine tRNA(GAU), alanine tRNA(UGC), arginine tRNA(ACG) and asparagine tRNA(GUU)). The gene organization of the IR regions in the liverwort chloroplast genome is conserved, although the IR regions are smaller (10,058 base-pairs) than any reported in higher plant chloroplasts. The small single-copy region (19,813 base-pairs) encoded genes for 17 open reading frames, a leucine tRNA(UAG) and a proline tRNA(GGG)-like sequence. We identified 12 open reading frames by homology of their coding sequences to a 4Fe-4S-type ferredoxin protein, a bacterial nitrogenase reductase component (Fe-protein), five human mitochondrial components of NADH dehydrogenase (ND1, ND4, ND4L, ND5 and ND6), two Escherichia coli ribosomal proteins (S15 and L21), two putative proteins encoded in the kinetoplast maxicircle DNA of Leishmania tarentolae (LtORF 3 and LtORF 4), and a bacterial permease inner membrane component (encoded by malF in E. coli or hisQ in Salmonella typhimurium).
Explore the source record for details and available documents.
The EEGs of 1416 healthy subjects aged 6-39 years were recorded and 1 min of background activity from Fp1, C3 and O1, was analyzed by a computerized wave form recognition method. Age development and sex differences of various EEG elements, which are employed in a conventional clinical EEG assessment, were statistically analyzed. The age developments of alpha and theta showed regional differences and were the most rapid in O1 and the slowest in C3. The delta amplitude, theta amplitude, theta continuity and percentage time of theta with an amplitude of 30 microV or more, which are important in a clinical EEG assessment, reached a stable level at 18-21 years of age in the 3 leads. The percentage time, amplitude and continuity of alpha in the 3 leads reached a stable level at 22-25 years of age. Including the low voltage theta in Fp1 and C3, all of the EEG elements reached the stable adult level at 26-29 years of age. Since there was a large interindividual variability in these age developments, the regression curves of the 10th and 90th percentiles of these EEG elements can be considered as quantitative standards for clinical EEG evaluation. As for sex differences, the percentage alpha time and alpha continuity were greater in males than in females after adolescence. The percentage theta time in Fp1 and C3 was greater in females than in males during childhood. The percentage beta time was higher in females than in males at all ages. But overall, these sex differences were minor compared with the differences associated with age developments of the EEG elements.
Explore the source record for details and available documents.
The tryptophan residues of two forms of pig heart lipoamide dehydrogenase (LD(I) and LD(II] were investigated fluorometrically. The tryptophan contents of LD(I) and LD(II) determined by the fluorescence method were 3 mol and 2 mol per mol of FAD, respectively. These values were in good agreement with those found by the MCD method. The microenvironments of the tryptophan residues were investigated by fluorescence quenching titration with acrylamide. The tryptophan residues of both enzymes were in heterogeneous microenvironments, and CD spectra showed some differences between these microenvironments in the two enzymes. Energy transfer from tryptophan residues to bound FAD was equally efficient in the two enzymes. It seems probable that the three tryptophan residues in LD(I) are all in different microenvironments, but that two of them are in microenvironments almost identical to those of the corresponding residues in LD(II).
The dynamic structures of two major forms (LD(I) and LD(II) of pig heart lipoamide dehydrogenase, resolved by TEAE-cellulose column chromatography, were studied by fluorescence depolarization. FAD and ANM were used as an intrinsic and an extrinsic fluorescent probe, respectively. In the experiments with bound FAD of lipoamide dehydrogenase, no thermal dependence of the fluorescence depolarization of either enzyme was observed and the values of polarization were close to the theoretical maximum value of 0.5. Both enzymes contained two reactive thiol groups which differed in their reactivities toward ANM. When the enzymes were labeled with one mol of ANM per mol of enzyme, the rotational relaxation times of LD(I) and LD(II) were found to be 18 ns and 196 ns, respectively. These findings indicate that the sement of LD(I) labeled with ANM fluctuates in the order of nanoseconds, whereas this segment of LD(II) is fixed rigidly. On the other hand, when the enzymes were labeled with two mol of ANM per mol of enzyme, both enzymes showed the composite result of fluorescence depolarization due to the motilities of the segment of enzyme and the whole enzyme molecule. These findings indicate that both LD(I) and LD(II) have the non-equivalent motilities of segments containing one reactive thiol group between the two monomers. In other words, the segment containing the ANM binding site of the one monomer is flexible and this segment of the other monomer is fixed rigidly in both enzymes.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.