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Y Kitoh

Publications and source records attributed to Y Kitoh.

At least 55 records · Page 3Linked to original sources
PubMed1993

Insertion of a 5' truncated L1 element into the 3' end of exon 44 of the dystrophin gene resulted in skipping of the exon during splicing in a case of Duchenne muscular dystrophy.

We report here the second evidence of retrotransposition of L1, which was found inserted into the dystrophin gene of a patient, causing Duchenne muscular dystrophy (DMD). When the PCR was used to amplify a region of the dystrophin gene encompassing exon 44 from genomic DNA of two Japanese brothers with DMD, it was found to be approximately 600 bp larger than expected. Both the normal and the abnormally large products were amplified from the DNA of their mother. However, the maternal grandparents did not have the abnormal allele, and the mutation must therefore have occurred in the mother. Analysis of nucleotide sequence of the amplified product from a patient disclosed that the insertion was present zero to two bases upstream from the 3' end of exon 44 and that two to four bases of the exon sequence were deleted from the insertion site. The insertion sequence was found to be composed of 606-608 bp and to be almost identical to the inverse complement of 3' portion of the L1 retrotransposon consensus sequence. The dystrophin gene transcript from peripheral lymphocytes of one of the patients was analyzed by using reverse transcription/semi-nested PCR. The size of the amplified product encompassing exon 42 to 46 was smaller than expected. Sequencing of the amplified product disclosed that the sequence of exon 43 was directly joined to that of exon 45. Exon 44 of the transcript was thus shown to be skipped during splicing. This novel mutation of the dystrophin gene has important implications regarding retrotransposition of an active L1 element and provides a new insight into the origins of mutations in the dystrophin gene.

Adult↗
PubMed1993

[A case of primary cardiac hemangiosarcoma].

A case of primary hemangiosarcoma of right atrium was reported. The patient was 43 years old female. She had the symptoms of tamponade due to massive bloody pericardial effusion. Echocardiography, computed tomography, NMR imaging and angiography revealed the precise delineation and extension of tumor, and also allowed diagnosis of hemangiosarcoma. Extirpation of tumor was performed under the cardiopulmonary bypass. The patient was died 3 months later after the operation for liver metastasis. The bloody pericardial effusion seems to be an important symptom of the primary malignant cardiac tumor, and early and precise diagnosis may allow successful operation and long survival of the patients.

Adult↗
PubMed1992

Amplification of ten deletion-rich exons of the dystrophin gene by polymerase chain reaction shows deletions in 36 of 90 Japanese families with Duchenne muscular dystrophy.

We analyzed DNA samples taken from 95 Duchenne muscular dystrophy (DMD) patients belonging to 90 different families in Japan using the polymerase chain reaction. Ten different regions at the 5' end or in the central region of the dystrophin cDNA gene that were previously shown to be prone to deletion were selected for amplification and analysis. Patients in 36 of the 90 families (40%) had deletions in at least one of these segments of the gene. Identical deletions were detected in the dystrophin gene of patients from the same family. The deletions were heterogeneous in size and location. One patient had deletions in 7 of the 10 amplified regions, while 19 patients from 18 families had a deletion in only one of the regions studied. Deletions at the 5' end were generally larger and more heterogeneous than those in the central region of the gene. One third of deletions had their proximal end breakpoints between exons 44 and 45. This region seems to be particularly vulnerable to gene breakage in DMD patients.

Asian People↗
PubMed1992

Partial deletion of a dystrophin gene leads to exon skipping and to loss of an intra-exon hairpin structure from the predicted mRNA precursor.

In dystrophin Kobe exon 19 of the dystrophin gene is skipped during the process of mRNA precursor splicing even though the splice sites are unchanged (Matsuo et al. J. Clin. Invest. 87:2127-2131,1991). In the predicted secondary structure of the mRNA precursor, exon 19 of dystrophin Kobe is paired with intron sequences, whereas a large part of exon sequence from wild type is paired with itself and folded into a large hairpin structure. As all of 22 additional dystrophin exons analyzed also form intra-exon hairpin structures, these structures may be considered essential components of exons. We suggest that the abolishment of a hairpin structure in the truncated exon of dystrophin Kobe might prevent the splicing machinery from recognizing the splice sites and induce exon skipping.

Base Composition↗
PubMed1992

Clinical experience of mitral valve reconstruction with artificial chordae implantation.

To expand the application of mitral valve reconstruction for pure mitral regurgitation due to diffuse leaflet prolapse, we have employed artificial chordae implantation using GPEP strips in 9 patients and 4-0 PTFE sutures in 20 patients since November 1986. The total number of GPEP strips implanted was 20 with a range from 1 to 4 (average 2.2 per patient) and 45 pairs of PTFE sutures with a range from 1 to 6 (average 2.3 per patient). There was one hospital death (3.4%). All other patients survived operation without valve-related complications except 1 patient who required reoperation for failure of mitral valve reconstruction. In 27 survivors free from reoperation, the amount of mitral regurgitation assessed postoperatively was none or trivial in 19 patients, mild in 7 and moderate in 1. All 27 patients improved to NYHA functional class I or II. So far, our results were no less acceptable than those with conventional procedures for mitral valve prolapse.

Adolescent↗
PubMed1992

Treatment of acute profound heart failure by ventricular assist device.

Sixteen patients with acute profound heart failure (HF) have been treated with the left ventricular assist device (LVAD), nine of them were successfully weaned from LVAD, and three of them were discharged and survived longer. Decompression of the left ventricle (LV) at the beginning will prevent overextension of impaired myocardium and accelerate scar formation. Gradual increase of LV work will promote the compensation ability of the residual myocardium. We found that continuous LVAD assistance can give time for the impaired heart to recover while maintaining normal circulation. For patients with profound HF which is beyond the limit of intra-aortic balloon pumping's (IABP) capability, LVAD is a more powerful and effective means. Although the heart recovered, many patients later died of multiple organ failure (MOF) which was probably caused by prolonged ischemia before LVAD application. For completely successful recovery from profound HF, diagnosis and deciding to use LVAD should not be delayed. It should be applied before major organs including the heart itself suffer irreversible damage. We have established a systematic therapeutic concept of treating acute HF patients using assisted circulation including LVAD.

Acute Disease↗
PubMed1992

[Effect of SL-1010 (sodium hyaluronate with high molecular weight) on experimental osteoarthritis induced by intra-articularly applied papain in rabbits].

Sodium hyaluronate (HA) with a molecular weight of approximately 600,000-1,200,000 is reportedly effective against osteoarthritis (OA). However, since HA with higher molecular weight is expected to be more effective against OA, we investigated the effects of HA (SL-1010) newly produced by fermentation with a molecular weight of 1,800,000-2,100,000 on the experimental OA induced by intraarticular injection of papain, into the knee joint of the rabbit, in comparison with those of HA with a molecular weight of about 950,000 (HA-95). When 0.4, 0.8, and 1.6% papain (0.5ml) was injected into the knee joint of the animal twice with a 3-day interval, there were dose-dependent degenerative changes and a decrease in sulfated glycosaminoglycan (S-GAG) in the articular cartilage with slight synovial inflammatory changes 6 weeks after the final injection of papain. In this OA model, intraarticular application of SL-1010 slightly reduced the degeneration of articular cartilage, compared with the injections of HA-95 or saline (control). SL-1010 also caused a significant recovery in the S-GAG level which was decreased in the cartilage of the OA model, compared with the control. In addition, SL-1010 inhibited the release of 35S-GAG from the cartilage obtained from normal and OA model joints. These results suggest that SL-1010 is effective in inhibiting the degeneration of cartilage in the OA model, probably due to the recovery of the S-GAG level by reducing the release of S-GAG from the cartilage.

Animals↗
PubMed1992

[Effects of SL-1010 (sodium hyaluronate with high molecular weight) on experimental osteoarthritis induced by intra-articularly applied papain in guinea pigs].

Effects of SL-1010 on the experimental osteoarthritis (OA) produced by intra-articular injection of papain, proteolytic enzyme, in the knee joint of the guinea pigs were histologically and biochemically investigated. In addition, experimental conditions to produce OA in guinea pig knee joint were also examined, since papain-induced OA has been mainly studied in rabbits. Six weeks after intra-articular injection of papain (1%, 0.1 ml), there were inflammatory reactions of the synovial membrane, degenerative changes in chondrocytes and the matrix of the articular cartilage, a decrease in the Safranin-O staining intensity and lowering of sulfated glycosaminoglycan. Electronmicroscopic observations revealed that the amorphous layer had disappeared and large bundles of unit collagen fibers and larger collagen fibers had appeared in the cartilage matrix. In the OA model, SL-1010 reduced the inflammatory reactions of the synovial membrane, inhibited development of degenerative changes in chondrocytes and the matrix of the articular cartilage and recovered the Safranin-O staining intensity. The sulfated glycosaminoglycan contents in the cartilage was significantly increased in the SL-1010-treated group, compared with the control group. The electromicroscopically observed charges in the papain-injected knee joint of the control group were rarely detected in the SL-1010-treated group. These results suggest that SL-1010 inhibits degenerative changes in the chondrocytes and the matrix probably by reducing synovial inflammation and protection of the cartilage in the OA model of guinea pigs.

Animals↗
PubMed1992

[One-staged repair for coarctation of the aorta and annuloaortic ectasia with severe aortic regurgitation in a patient with Turner syndrome].

A 27-year-old woman with Turner syndrome was admitted to NCVC for congestive heart failure. 2-D echocardiography and magnetic resonance imaging (MRI) disclosed annuloaortic ectasia with severe aortic regurgitation and coarctation of the aorta. One staged operation by a modified Bentall procedure and extra-anatomical bypass grafting from the ascending aorta to the infrarenal abdominal aorta was successfully performed. The postoperative course was uneventful. The pressure gradient between upper and lower extremities decreased as to be 30 mmHg compared with preoperative 60 mmHg.

Adult↗
PubMed1991

Screening of gene deletions by polymerase chain reaction in Japanese patients with Duchenne muscular dystrophy.

Gene deletions were screened in 49 Japanese Duchenne muscular dystrophy patients from 43 families, using the polymerase chain reaction. Enzymatic amplification was carried out on six regions prone to deletion. Fifteen of 43 families (33%) had gene deletions in at least one of the six regions. This frequency was almost the same as that previously reported in Caucasians. The mid-part of the dystrophin gene was the location most frequently deleted. The frequency of deletion of the region encompassing exon 45 was higher in Japanese families (18.4%) than in Caucasians.

Blotting, Southern↗
PubMed1991

Exon skipping during splicing of dystrophin mRNA precursor due to an intraexon deletion in the dystrophin gene of Duchenne muscular dystrophy kobe.

Recent molecular studies have shown that in a patient with Duchenne muscular dystrophy (DMD) Kobe, the size of exon 19 of the dystrophin gene was reduced to 36 bp due to the deletion of 52 bp out of 88 bp of the exon. The consensus sequences at the 5' and 3' splice sites of exon 19 were unaltered (Matsuo, M., et al. 1990. Biochem. Biophys. Res. Commun. 170:963-967). To further elucidate the molecular nature of the defect, we examined the primary structure of cytoplasmic dystrophin mRNA of the DMD Kobe patient across the junctions of exons 18, 19, and 20 by gel electrophoresis and sequencing of polymerase chain reaction-amplified cDNA. The mRNA coding for dystrophin was reverse transcribed using random primers, and the cDNA was then enzymatically amplified in vitro. The targeted fragment was smaller than expected from the genomic DNA analysis. By sequencing of the amplified product, we found that exon 18 was joined directly to exon 20, so that exon 19 was completely absent, suggesting that this exon was skipped during processing of the dystrophin mRNA precursor. All other bases in the amplified product were unaltered. Therefore, the data strongly suggest that the internal exon deletion generates an abnormally spliced mRNA in which the sequence of exon 18 is joined to the sequence of exon 20. We propose that the deletion is responsible for abnormal processing of the DMD Kobe allele. This finding has important implications regarding the determinants of a functional splice site.

Base Sequence↗
PubMed1990

A very small frame-shifting deletion within exon 19 of the Duchenne muscular dystrophy gene.

We report the molecular characterization of a Japanese Duchenne muscular dystrophy (DMD) patient. The analysis of genomic gene by polymerase chain reaction indicates that the individuals have a limited deletion within an amplified region, which encompasses exon 19 of DMD gene. The amplified region was sequenced. Comparison of the deletion joint sequence with the normal amplified region sequence indicates that both 5' and 3' deletion end points are present within exon 19 and the deletion removes total 52 bp out of 88 bp of exon 19. Both his mother and sister are carriers of the deletion-containing allele. The mutation introduces a termination codon at residue 791 in exon 20, and is predicted to result in the production of a severely truncated protein. This sort of deletion (designated as DMD-Kobe) might be classified as a new type of DMD gene abnormality.

Adolescent↗
PubMed1990

[Clinical results of open heart surgery within 2 weeks after cardiogenic embolic stroke].

Fourteen patients, 5 with infective valvular disease (IVD), 7 with non-infective valvular disease (NVD) and 3 with LA myxoma, underwent open heart surgery within 2 weeks after cardiogenic embolic stroke because of uncontrolled heart failure or recurrent embolism. Fifty percent of patients experienced a second embolism within 2 weeks of the initial stroke. Preoperative brain CT revealed no hemorrhagic infarction in all patients. However, in 3 of 5 patients with IVD, who had large brain infarction, one patient died from massive brain edema and two patients from severe brain hemorrhage. The other 2 patients with IVD, who had small infarction, and the remaining 7 patients with NVD and LA myxoma, even having large or small infarction, recovered without any complications. From these results, we concluded that 1) Open heart surgery within 2 weeks after initial stroke was safe in patients with no brain infarction and small non-hemorrhagic infarction, 2) Patients with IVD should be treated surgically before embolic stroke, because mortality rate was so high even in patients with non-hemorrhagic infarction.

Adult↗
PubMed1987

Continuous measurement of coronary sinus oxygen saturation after cardiac surgery.

To estimate the balance of myocardial oxygen supply and demand after cardiac surgery, we used fiberoptic reflection oximetry to measure continuously the coronary sinus oxygen saturation (ScsO2) in six patients. ScsO2 decreased with massive bleeding, atrial fibrillation, after DC countershock, and continuous iv infusion of hydralazine, phentolamine, and dibutyryl cyclic-AMP. ScsO2 increased with iv infusion of nicardipine or nitroglycerin, suggesting an improved oxygen metabolism in the myocardium. Continuous ScsO2 measurement provides such on-line information on myocardial oxygenation in postoperative patients.

Adult↗