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M Sakurai

Publications and source records attributed to M Sakurai.

At least 91 records · Page 5Linked to original sources
PubMed2000

Adenovirus-mediated glial cell line-derived neurotrophic factor gene delivery reduces motor neuron injury after transient spinal cord ischemia in rabbits.

OBJECTIVE: Glial cell line-derived neurotrophic factor (GDNF) has protective effects on various injuries involving the central and peripheral nervous systems in vitro and vivo. However, the possible protective effect of GDNF on spinal cord ischemia and the exact mechanism involved in the ameliorative effect of GDNF on ischemic spinal cord injuries are not fully understood. Therefore, we investigated the possible protective effect of the adenovirus-mediated GDNF gene delivery on transient spinal cord ischemia in rabbits. METHODS: The adenoviral vector (lacZ gene as a control or GDNF gene contained) was injected directly into the lumbar spinal cord via a needle inserted into the dorsal spine 2 days before the animal was subjected to 15 minutes of spinal cord ischemia induced by infrarenal aortic occlusion. In situ terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL staining) was performed, and temporal profiles of the GDNF and caspase-3 (caspase-3 is the marker of apoptotic change) immunoreactivity were investigated. RESULTS: In the control rabbit, the majority of motor neurons showed selective cell death at 7 days of reperfusion. Immunocytochemistry showed that in situ TUNEL staining was selectively detected at 2 days of reperfusion in motor neuron nuclei. GDNF and caspase-3 were selectively induced in the motor neuron cells at 8 hours of reperfusion. In the GDNF-treated group, a large population of motor neuron cells was still surviving at 7 days after having been subjected to 15 minutes of ischemia. Unlike the control group, the GDNF-treated group expressed GDNF persistently. Induction of TUNEL staining and immunoreactivity for caspase-3 were greatly reduced by the GDNF treatment. CONCLUSION: These results suggest that the reduction in motor neuron death by GDNF was greatly associated with a reduction in DNA fragmentation and apoptotic signals of the caspase-3 cascade; they further suggest a great potential for gene therapy for paraplegic patients in the future.

Adenoviridae↗
PubMed2000

Acute infectious urticaria: clinical and laboratory analysis in nineteen patients.

We treated 19 Japanese patients with acute urticaria presumably caused by infection during the five years from 1994 to 1998. The patients' ages ranged from 2 to 66 years (8 males and 11 females). Most of them had urticaria, angioedema, high fever, neutrophilia, and high serum levels of C reactive protein (CRP). The skin rash lasted more than 24 hours. In four patients, a flow cytometric analysis revealed that the percentage of circulating T cells bearing T-cell receptor V beta 3 was decreased during the active stage and that this decrease was sustained for at least 2 to 3 weeks. This suggests that certain T-cell populations were numerically altered in association with the occurrence of the disease. A retrospective review indicated that the combination therapy with corticosteroid and antibiotics was more effective than the single use of either agent.

Acute Disease↗
PubMed2000

Congenital diaphragmatic hernia in neonates: variations in umbilical catheter and enteric tube position.

PURPOSE: To evaluate anatomic variations of support apparatus position on radiographs obtained in neonates with congenital diaphragmatic hernia (CDH). MATERIALS AND METHODS: The authors evaluated radiographs obtained in 71 neonates with CDH to determine whether nasogastric tubes, umbilical venous catheters, and umbilical arterial catheters deviated from their expected anatomic course. The relationship between deviation patterns and hernia contents was evaluated. RESULTS: Sixty-eight neonates-54 with left-sided CDH and 14 with right-sided CDH-had a nasogastric tube. The tubes in 21 patients with left-sided CDH had a normal anatomic course at radiography. Nineteen of these patients did not have stomach in the hernia. In 13 patients, the tip of the nasogastric tube was lodged at the esophagogastric junction. In 17 patients, the tube was in the left hemithorax. In all 30 of these patients, the stomach was within the CDH. All nasogastric tubes in the 14 patients with right-sided CDH had leftward deviation. Thirty-seven patients-27 with left-sided CDH and 10 with right-sided CDH-had umbilical venous catheters. The catheters in 12 patients with left-sided CDH had apex leftward convexity. The umbilical venous catheter in eight patients with right-sided CDH had rightward shift; all eight patients had liver herniation. CONCLUSION: The positions of nasogastric tubes and umbilical venous catheters vary in several predictable patterns in neonates with CDH. Knowledge of these variations may be helpful for supporting the diagnosis of CDH in unclear cases and thus avoiding unnecessary apparatus adjustments, and for predicting hernia contents.

Catheterization, Peripheral↗
PubMed2000

Nephrotic syndrome due to membranous nephropathy associated with metastatic prostate cancer: rapid remission after initial endocrine therapy.

A case of severe nephrotic syndrome (urinary protein excretion 12.9 g/day) due to membranous nephropathy associated with untreated prostate cancer and multiple bone metastases is described. A combination of initial endocrine treatment and steroid therapy resulted in normalization of prostate-specific antigen levels followed by a rapid decrease of urinary protein excretion within 4 months. No proteinuria was subsequently detected. Seven months after the initiation of therapy, the patient remained well with complete clinical remission from the nephrotic syndrome. This rapid achievement of remission may have been due to tumor shrinkage by androgen ablation in addition to steroid therapy of the membranous nephropathy. The nephrotic syndrome is a rare complication of prostate cancer, and, to the best of our knowledge, no previous cases have been reported of membranous nephropathy as one of the first disease manifestations.

Adenocarcinoma↗
PubMed2000

Cyclin D1 and Cdk4 protein induction in motor neurons after transient spinal cord ischemia in rabbits.

BACKGROUND AND PURPOSE: The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. We hypothesized that spinal motor neurons might be lost by programmed cell death and investigated a possible mechanism of neuronal death by detection of double-strand breaks in genomic DNA and immunohistochemical analysis for cyclin D1 and cyclin-dependent kinases (Cdk) 4. METHODS: We used a rabbit spinal cord ischemia model with a balloon catheter. Spinal cord was removed at 8 hours and 1, 2, and 7 days after 15 minutes of transient ischemia, and histological changes were studied with hematoxylin-eosin staining. In situ terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labeling (TUNEL), DNA fragment with gel electrophoresis, Western blot analysis for cyclin D1 and Cdk4, and temporal profiles of cyclin D1 and Cdk4 immunoreactivity were investigated. RESULTS: Most motor neurons were preserved until 2 days but were selectively lost at 7 days of reperfusion. Immunocytochemistry showed positive TUNEL selectively at 2 days of reperfusion in spinal motor neuron nuclei. Typical ladders of oligonucleosomal DNA fragments were detected at 2 days of reperfusion. Immunoreactivity of cyclin D1 and Cdk4 proteins was induced selectively at 8 hours in motor neuron nuclei, which eventually died. CONCLUSIONS: These results indicate that induction of cyclin D1 and Cdk4 may be implicated in programmed cell death change after transient spinal cord ischemia in rabbits.

Animals↗
PubMed2000

Prevalence and clinical characteristics of patients with atrial fibrillation: analysis of 20,000 cases in Japan.

In Japan, data on the epidemiological and clinical features of atrial fibrillation (AF) are rather sparse; even less data are available on the risk of thromboembolism in nonvalvular AF. The present study enrolled 19,825 patients who visited the cardiovascular clinics of the 13 hospitals in Hokkaido, Japan, between March and July 1995. The prevalence of AF, the clinical characteristics of AF patients, and the occurrence of ischemic events were examined during the 2 year follow-up period. The prevalence of AF increased with age, and the overall prevalence was 14%. Antithrombotic therapy was used in 57% of AF patients and the incidence of ischemic events during the follow-up period was 4.6% in all AF patients. Warfarin reduced the risk of ischemic events in both the valvular and nonvalvular AF groups. A history of cerebrovascular accidents, advanced age, and the presence of underlying heart disease were each associated with a significantly increased risk of ischemic events in the nonvalvular AF group. These results show a lower incidence of ischemic events and more frequent use of antiplatelet drugs in the nonvalvular AF group. Further prospective studies are needed to determine the best preventive methods for thromboembolic complications in Japanese patients with nonvalvular AF.

Adult↗
PubMed2000

Scant parasitemia in BALB/c mice with congenital malaria infection.

Balb/c mice were examined to determine whether or not they transmitted rodent malaria, Plasmodium berghei, to their fetuses. On the 15th day of pregnancy, mice were inoculated with approximately 3 x 10(6) P. berghei-infected erythrocytes by peritoneal injection. The blood from 27 adult females and 196 neonates was examined using a sensitive polymerase chain reaction (PCR) method with a detection level of approximately 1 parasite/microl blood. The average parasitemia of females at delivery was 8.1%, ranging from nondetectable to 37.1%. In 12 females, nested PCR established the presence of blood parasite DNA. Malaria parasites were microscopically confirmed in 2 of the 12 neonates. Maternal parasitemia at the time of delivery was not correlated with the incidence of vertical infection (6.1%), which was higher in this study than that found in previous studies. Although the combination of balb/c mice and P. berghei has not been used to examine vertical transmission of malaria, our report showed that this model may be used for this purpose.

Animals↗
PubMed2000

[Retroperitoneal paraganglioma incidentally detected by health examination: a case report].

We report a case of non-functioning retroperitoneal paraganglioma detected incidentally by health examination in a 60-year-old female without any clinical manifestation. She was admitted to our hospital for the purpose of evaluation of a renal mass detected by ultrasound sonography. Computed tomography, magnetic resonance imaging and angiography revealed the heterogeneously-enhanced 10 x 10 cm mass in the left retroperitoneal space without any distant metastasis. It was suspected to be a renal cell carcinoma. All laboratory data, including those from endocrinological examinations, were within normal ranges. Radical nephrectomy was performed to resect en bloc the mass and the left kidney. The pathological and immunohistochemical examinations of the mass which was completely separated from the kidney and the adrenal gland, showed characteristic features of paraganglioma with vascular and capsular invasion, with a final clinical diagnosis of the pathologically-malignant non-functioning paraganglioma occurring between the left kidney and the adrenal gland.

Female↗
PubMed2000

[Collagen disease and reflux esophagitis].

The incidence of reflux esophagitis in cases of collagen disease is about 10%. However, reflux esophagitis is seen in about 50% of scleroderma cases. Moreover, in scleroderma the severity is correlated with the time since onset of the disease. Endoscopy is performed more often in the severe cases, and little therapeutic effect can be expected without use of a proton pump inhibitor.

Adult↗
PubMed1999

Quantitative analysis of cardiac 3-L-nitrotyrosine during acute allograft rejection in an experimental heart transplantation.

BACKGROUND: Recent studies have shown that nitric oxide interacts with superoxide to form peroxynitrite, a potent oxidant that modifies cellular proteins producing 3-L-nitrotyrosine (N-Tyr). This study was designed to evaluate N-Tyr quantitatively with high-performance liquid chromatography (HPLC) during cardiac allograft rejection. METHODS: Rat transplanted hearts (allogeneic or syngeneic grafts) were examined with HPLC analysis, immunohistochemistry for N-Tyr, and histological studies on 0, 1, 3, and 7 days after transplantation. RESULTS: No histological rejection was found in syngeneic grafts, or day 0 or 1 allografts. HPLC demonstrated that N-Tyr in allografts increased on day 1 and continued to increase through day 7, while N-Tyr was not detected in any syngeneic grafts. Immunostaining of the allografts did not show N-Tyr on day 1. CONCLUSION: These results demonstrate that N-Tyr shows a time-dependent accumulation in cardiac allografts during acute rejection. N-Tyr detection using HPLC may be an useful maker for early diagnosis of acute rejection before pathological rejection occurs.

Acute Disease↗
PubMed1999

Induction of glial cell line-derived neurotrophic factor and c-ret porto-oncogene-like immunoreactivity in rabbit spinal cord after transient ischemia.

The mechanism of spinal cord injury has been thought to be related with tissue ischemia, and spinal motor neuron cells are suggested to be vulnerable to ischemia. To evaluate the mechanism of such vulnerability of motor neurons, we attempted to make a reproducible model of spinal cord ischemia. Using this model, the inductions of glial cell line-derived neurotrophic factor (GDNF) and the c-ret porto-oncogene (RET) receptor tyrosine kinase were investigated with immunohistochemical analyses for up to 7 days of the reperfusion following 15 min of ischemia in rabbit spinal cord. Spinal cord sections from animals sacrificed at 8 h, 1, 2, and 7 days following the 15 min of ischemia were immunohistochemically evaluated using monoclonal antibodies for GDNF and RET. Following the 15 min of ischemia, the majority of the motor neurons showed selective cell death at 7 days of reperfusion. Immunoreactivity of GDNF and RET were induced at 8 h of reperfusion selectively in motor neuron cells. No glial cells were stained in the spinal cord sections. The induction of GDNF and RET proteins at the early stage of reperfusion may be related to the transient functional recovery of neurons after ischemia.

Animals↗
PubMed1999

Identification of a novel phosphorylation site on histone H3 coupled with mitotic chromosome condensation.

Histone H3 (H3) phosphorylation at Ser(10) occurs during mitosis in eukaryotes and was recently shown to play an important role in chromosome condensation in Tetrahymena. When producing monoclonal antibodies that recognize glial fibrillary acidic protein phosphorylation at Thr(7), we obtained some monoclonal antibodies that cross-reacted with early mitotic chromosomes. They reacted with 15-kDa phosphoprotein specifically in mitotic cell lysate. With microsequencing, this phosphoprotein was proved to be H3. Mutational analysis revealed that they recognized H3 Ser(28) phosphorylation. Then we produced a monoclonal antibody, HTA28, using a phosphopeptide corresponding to phosphorylated H3 Ser(28). This antibody specifically recognized the phosphorylation of H3 Ser(28) but not that of glial fibrillary acidic protein Thr(7). Immunocytochemical studies with HTA28 revealed that Ser(28) phosphorylation occurred in chromosomes predominantly during early mitosis and coincided with the initiation of mitotic chromosome condensation. Biochemical analyses using (32)P-labeled mitotic cells also confirmed that H3 is phosphorylated at Ser(28) during early mitosis. In addition, we found that H3 is phosphorylated at Ser(28) as well as Ser(10) when premature chromosome condensation was induced in tsBN2 cells. These observations suggest that H3 phosphorylation at Ser(28), together with Ser(10), is a conserved event and is likely to be involved in mitotic chromosome condensation.

Amino Acid Sequence↗
PubMed1999

The volume and compressibility changes of lysozyme associated with guanidinium chloride and pressure-assisted unfolding.

The apparent specific volumes and isentropic compressibilities of hen egg white lysozyme were measured in aqueous guanidinium chloride solutions at 25 degrees C by means of a vibrational densimeter and a sing-around ultrasonic velocimeter. Little transition attributable to a protein unfolding was detected in the partial specific volume, while the partial specific isentropic compressibility decreased slightly around the transition region. The pressure-assisted unfolding was also investigated in aqueous guanidinium chloride solutions by means of ultraviolet spectroscopy. Assuming a two-state transition model, it was found that the free energy change of unfolding depends almost linearly on pressure and the unfolding reaction is accompanied by a small decrease in volume. The compressibility behavior is in conflict with the notion that a protein structure is almost completely unfolded by guanidinium chloride and most of the amino acid residues in the protein interior are exposed to solvent. These results support the current view that globular proteins have some residual structures even in the unfolded state induced by a strong denaturant.

Animals↗
PubMed1999

Impact of cilostazol on restenosis after percutaneous coronary balloon angioplasty.

BACKGROUND: Restenosis after percutaneous transluminal coronary (balloon) angioplasty (PTCA) remains a major drawback of the procedure. We previously reported that cilostazol, a platelet aggregation inhibitor, inhibited intimal proliferation after directional coronary atherectomy and reduced the restenosis rate in humans. The present study aimed to determine the effect of cilostazol on restenosis after PTCA. METHODS AND RESULTS: Two hundred eleven patients with 273 lesions who underwent successful PTCA were randomly assigned to the cilostazol (200 mg/d) group or the aspirin (250 mg/d) control group. Administration of cilostazol was initiated immediately after PTCA and continued for 3 months of follow-up. Quantitative coronary angiography was performed before PTCA and after PTCA and at follow-up. Reference diameter, minimal lumen diameter, and percent diameter stenosis (DS) were measured by quantitative coronary angiography. Angiographic restenosis was defined as DS at follow-up >50%. Eligible follow-up angiography was performed in 94 patients with 123 lesions in the cilostazol group and in 99 patients with 129 lesions in the control group. The baseline characteristics and results of PTCA showed no significant difference between the 2 groups. However, minimal lumen diameter at follow-up was significantly larger (1.65+/-0.55 vs 1.37+/-0.58 mm; P<0.0001) and DS was significantly lower (34.1+/-17.8% vs 45.6+/-19. 3%; P<0.0001) in the cilostazol group. Restenosis and target lesion revascularization rates were also significantly lower in the cilostazol group (17.9% vs 39.5%; P<0.001 and 11.4% vs 28.7%; P<0. 001). CONCLUSIONS: Cilostazol significantly reduces restenosis and target lesion revascularization rates after successful PTCA.

Aged↗