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Biomedical subjects

N Mitsukawa

Publications and source records attributed to N Mitsukawa.

17 recordsLinked to original sources

A case of improved obstructive sleep apnea by distraction osteogenesis for midface hypoplasia of an infantile Crouzon's syndrome.

We performed Le Fort III midfacial advancement with gradual distraction using internal devices on a 2-year 5-month-old boy with Crouzon's syndrome with associated severe obstructive sleep apnea. The device was not activated until 7 days after surgery, after which the distraction was initiated, 1 mm per day, and the midface was advanced 4 mm intraoperatively and distracted 12 mm postoperatively. A total advancement of 16 mm was obtained. The obstructive sleep apnea improved remarkably after the distraction. In infants and younger children with associated severe obstructive sleep apnea, advancement by distraction osteogenesis of the midface in Le Fort III maxillary osteotomy will be initially indicated to obviate tracheostomy improving the upper airway obstruction.

Craniofacial Dysostosis↗

Surgical program for craniosynostosis using three-dimensional solid model, combined with autologous blood transfusion in a Japanese craniofacial unit.

Since April 1997 at St. Mary's Craniofacial Unit, simulated surgery using a three-dimensional solid model made preoperatively was carried out, which enable sufficient autologous blood banking before the surgery. This study was conducted in eight patients presenting with plagiocephaly, brachycephaly, and oxycephaly consisting of simple craniosynostosis and syndromic craniosynostosis. Four cases (numbers 1-4) conducted with simulated surgery using three-dimensional solid models and fronto-orbital advancement with reshaping, as well as autologous blood transfusion were selected for the later-term group. For the first-term group, four cases (numbers 5-8) that were performed before the introduction of the abovementioned treatment were selected. The later-term group compared with the first-term group showed a decrease in operating time by an average of 1 hour, blood loss during surgery by 90 ml, and one fifth the amount of homologous blood transfusion. Also, 2 cases in the later-term group (cases 3 and 4) were able to avoid homologous blood transfusion, and they had autologous blood transfusion of 30 to 33 ml/kg. The surgical techniques will be improved with repeated cases of simulated surgery, aiming for the minimum invasive surgery. Also, the use of autologous blood transfusion is expected to increase as a less invasive surgery.

Blood Loss, Surgical↗

C-shape extended transconjunctival approach for the exposure and osteotomy of traumatic orbitozygomaticomaxillary deformities.

In the treatment of post-traumatic deformities of the orbitozygomaticomaxillary complex resulting from trauma, the most appropriate exposure must be used. The choice of exposures includes the bicoronal approach and the periorbital incisions. When the whole orbitozygomatic complex is malpositioned, the bicoronal approach is desirable; this can be combined with buccal and eyelid incisions. However, the bicoronal approach is complicated by a longer duration of operation time, post-surgical scars that tend to show, and potential damage to the temporal branch of the facial nerve. A new approach using a C-shape extended transconjunctival approach is possible to have one field of vision to osteotomize the frontozygomatic suture, the lateral orbital wall, inferior orbital rim, lateral maxillary buttress, and zygomatic arch. It takes less operating time and the post-surgical scars are shorter than the bicoronal approach.

Accidents, Traffic↗

Molecular cloning and characterization of a cysteine-rich 16.6-kDa prolamin in rice seeds.

An alcohol-soluble storage protein, a 16.6-kDa prolamin found in rice seeds, was purified from both the total protein body and purified type I protein body fractions. The partial amino acid sequences of three tryptic peptides generated from the purified polypeptide were analyzed. A part of the 16.6-kDa prolamin cDNA was amplified from developing seed mRNA by the reverse transcribed polymerase chain reaction using an oligo (dT) primer and a primer which was synthesized based on the partial amino acid sequence. The amplified product was used to isolate the full-length cDNA clone (lambda RP16) from a developing seed cDNA library. The cDNA has an open reading frame encoding a hydrophobic polypeptide of 149 amino acids. The polypeptide was rich in glutamine (20.0%), cysteine (10.0%), and methionine (6.9%). The cysteine content was higher than those of most other rice storage proteins. Messenger RNA of the 16.6-kDa prolamin was detected in seeds, but not in other aerial tissues.

Amino Acid Sequence↗

Establishment of framework P1 clones for map-based cloning and genome sequencing: direct RFLP mapping of large clones.

Large insert capacity, clone stability and convenient propagation in Escherichia coli have made bacterial artificial chromosome and phage P1 vector-based libraries the first choice for large-scale sequencing projects, and these libraries have also proven useful for chromosome walking. The application of these libraries for either purpose is greatly facilitated by the establishment of a set of framework clones distributed across the genome. Using a P1-based library of Arabidopsis thaliana with genomic inserts of 70-90kb (Liu, Y.-G., Mitsukawa, N., Vazquez-Tello, A., Whittier, R.F., 1995. Generation of a high-quality P1 library of Arabidopsis suitable for chromosome walking. Plant J. 7, 351-358), we have now established such a set of framework clones. To date, such clones have usually been identified by hybridization to smaller, previously mapped clones that detect restriction fragment length polymorphisms (RFLPs). In order to establish framework clones more efficiently, we refined protocols for P1 clone DNA isolation and RFLP detection in order to employ whole P1 clones directly as probes. This strategy enabled a very high rate of RFLP detection, and obviated the need to screen the P1 library with smaller RFLP probes. Altogether 95 clones were mapped providing a framework into which further clones can be integrated by physical overlap.

Arabidopsis↗

Phosphate transporter gene family of Arabidopsis thaliana.

Using a high-affinity phosphate transporter gene of Arabidopsis thaliana, PHT1, as a probe, three Arabidopsis homologs were isolated, named PHT4, PHT5 and PHT6, in addition to the previously isolated PHT2 and PHT3. The amino acid sequences deduced from the three nucleotides were 32-42% homologous with microbial phosphate transporters of Saccharomyces cerevisiae (PHO84), Neurospora crassa (PHO-5) and Glomus versiforme (GvPT). PHT1, PHT2, PHT3 and PHT6 were clustered in a 25-kbp region of chromosome V. PHT1 and PHT4 transcripts were detected in roots. Interestingly, suspension-cultured cells expressed only PHT4. PHT4 and PHT5 located within a genetic distance of 6.4 cM on chromosome II, and were close to a phosphate accumulation mutant pho2. Genomic sequencing revealed no difference in the sequences of the two genes in both pho2 and wild-type. The PHT4 transcript was expressed at similar levels in the mutant and wild-type. These results demonstrate that neither PHT4 nor PHT5 is allelic to PHO2.

Amino Acid Sequence↗

Overexpression of an Arabidopsis thaliana high-affinity phosphate transporter gene in tobacco cultured cells enhances cell growth under phosphate-limited conditions.

A higher plant homologue to the high-affinity phosphate transporter gene of yeast (Saccharomyces cerevisiae) PHO84 was isolated from Arabidopsis thaliana. Expression of the Arabidopsis gene PHT1 at high levels in tobacco-cultured cells increased the rate of phosphate uptake. The uptake activity attributable to the transgene was inhibited by protonophores, suggesting an H+ cotransport mechanism of phosphate uptake, and had a Km of 3.1 microM which is within limits characteristic of high-affinity transport mechanisms. These results indicate that PHT1 encodes a high-affinity phosphate transporter. The transgenic cells exhibited increased biomass production when the supply of phosphate was limited, establishing gene engineering of phosphate transport as one approach toward enhancing plant cell growth.

Arabidopsis↗

AtPLC2, a gene encoding phosphoinositide-specific phospholipase C, is constitutively expressed in vegetative and floral tissues in Arabidopsis thaliana.

A cDNA encoding a phosphoinositide-specific phospholipase C (PI-PLC) from the higher plant Arabidopsis thaliana was cloned and characterized. The gene corresponding to this cDNA is designated AtPLC2. The overall structure of the predicted AtPLC2 protein is similar to those of plant PI-PLCs and mammalian delta-type PI-PLCs. Northern blot analysis revealed that AtPLC2 is expressed constitutively whereas AtPLC1S, another gene for PI-PLC of Arabidopsis, is induced by environmental stresses such as dehydration and salinity, indicating that the function of AtPLC2 is distinct from that of AtPLC1S. The AtPLC2 mRNA was detected in vegetative and floral tissues. We determined the positions of these two PI-PLCs genes on Arabidopsis chromosomes by RFLP mapping using P1 genomic clones.

Amino Acid Sequence↗

Molecular cloning and characterization of a gene that encodes a MYC-related protein in Arabidopsis.

In plants, MYC-related proteins function as transcription factors involved in anthocyanin production and trichome development. We cloned a gene, Atmyc1, and its corresponding cDNA, that encodes for a MYC-related protein from Arabidopsis thaliana. The putative protein has a basic/helix-loop-helix motif at the C-terminus and a highly homologous region with that of the maize B/R family at the N-terminus. The promoter region of Atmyc1 contains a Sph box (CATGCATG) that is known as a cis-regulatory element conferring seed-specific expression. In fact, Atmyc1 transcripts were more abundant in developing seeds than in stems and leaves where trichomes are normally expressed. Restriction fragment length polymorphism mapping demonstrated that Atmyc1 is located on the upper region of chromosome 4, which clearly indicates that Atmyc1 is distinct from the ttg (transparent testa glabrous) locus that affects both trichome development and anthocyanin biosynthesis.

Amino Acid Sequence↗

Isolation and mapping of a new set of 129 RFLP markers in Arabidopsis thaliana using recombinant inbred lines.

A new collection of 129 Arabidopsis thaliana RFLP markers has been established based upon DNA fragments cloned in the pUC119 plasmid vector and insert end sequences of P1 clones. Dominant/null alleles affecting low-copy number sequences account for nine of the mapped polymorphisms, suggesting that deletions are not rare in A. thaliana. Recombinant inbred (RI) lines were used for mapping these marker loci. RI line-based mapping allows integration of this set of markers with markers previously reported as well as with any markers mapped in the future using this replenishable mapping resource. These markers are useful for map-based gene isolation and genome physical mapping in A. thaliana as well as studies of chromosome colinearity (synteny) with related species.

Arabidopsis↗

The Arabidopsis ERECTA gene encodes a putative receptor protein kinase with extracellular leucine-rich repeats.

Arabidopsis Landsberg erecta is one of the most popular ecotypes and is used widely for both molecular and genetic studies. It harbors the erecta (er) mutation, which confers a compact inflorescence, blunt fruits, and short petioles. We have identified five er mutant alleles from ecotypes Columbia and Wassilewskija. Phenotypic characterization of the mutant alleles suggests a role for the ER gene in regulating the shape of organs originating from the shoot apical meristem. We cloned the ER gene, and here, we report that it encodes a putative receptor protein kinases. The deduced ER protein contains a cytoplasmic protein kinase catalytic domain, a transmembrane region, and an extracellular domain consisting of leucine-rich repeats, which are thought to interact with other macromolecules. Our results suggest that cell-cell communication mediated by a receptor kinase has an important role in plant morphogenesis.

Alleles↗

Cloning and sequencing of a rice gene encoding the 13-kDa prolamin polypeptide.

A gene encoding the 13-kDa prolamin polypeptide was isolated from a rice genomic library (lambdaEMBL3) and the nucleotide sequence of an about 3-kbp EcoRI fragment was analyzed. The cloned gene (NRP33) codes for a protein composed of 156 amino acids, including a signal peptide of 19 amino acid residues and no intron is present in the genomic clone. The nucleotide sequence contains consensus TATA and CAAT boxes, and two polyadenylation signals. In addition, there are two conserved sequences named the -- 300 element and 10 consecutive repeats of the trinucleotide ATT in the 5' noncoding sequence.

Amino Acid Sequence↗

Efficient isolation and mapping of Arabidopsis thaliana T-DNA insert junctions by thermal asymmetric interlaced PCR.

Thermal asymmetric interlaced (TAIL-) PCR is an efficient technique for amplifying insert ends from yeast artificial chromosome (YAC) and P1 clones. Highly specific amplification is achieved without resort to complex manipulations before or after PCR. The adaptation of this method for recovery and mapping of genomic sequences flanking T-DNA insertions in Arabidopsis thaliana is described. Insertion-specific products were amplified from 183 of 190 tested T-DNA insertion lines. Reconstruction experiments indicate that the technique can recover single-copy sequences from genomes as complex as common wheat (1.5 x 10(10) bp). RFLPs were screened using 122 unique flanking sequence probes, and the insertion sites of 26 T-DNA transgenic lines were determined on an RFLP map. These lines, whose mapped T-DNA insertions confer hygromycin resistance, can be used for fine-scale mapping of linked phenotypic loci.

Arabidopsis↗

Cloning and characterization of a cDNA encoding a rice 13 kDa prolamin.

A cDNA library constructed from mRNAs obtained from developing rice endosperm was screened with a cDNA clone (lambda RM7) of highest frequency of occurrence (1.8%). The translation product directed by the mRNA which was hybrid-released from lambda RM7 cDNA in a wheat germ cell-free system showed a molecular size of 13 kDa when coexisting with the protein body fraction of developing maize endosperm. A polypeptide sequence composed of 156 amino acids was deduced from the nucleotide sequence. By comparison with the 19 N-terminal amino acids obtained from Edman degradation of the isolated rice 13 kDa prolamin fraction, the signal sequence was determined as consisting of 19 amino acids. The deduced polypeptide is rich in hydrophobic amino acids such as Leu and Val, and also in Gln, but lacks Lys. Hence, the amino acid composition is consistent with that of rice 13 kDa prolamin. By homology with previously reported cereal prolamins, only a single octapeptide sequence, Gln-Gln-Gln-Cys-Cys-Gln-Gln-Leu, which was observed in 15 kDa and 27 kDa zein, B- and gamma-hordein, alpha/beta- and gamma-gliadin, and gamma-secalin was conserved in the rice 10 kDa and 13 kDa prolamin. No repetitive sequences and/or sequences homologous to other cereal prolamins, except the above octapeptide, were observed for the mature 13 kDa prolamin polypeptide. The signal sequence region of the 13 kDa prolamin, however, shows homology of more than 65% in both the nucleotide sequence and the amino acid sequence with rice 10 kDa prolamin and maize zein.

Amino Acid Sequence↗