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Biomedical subjects

K Sugimoto

Publications and source records attributed to K Sugimoto.

At least 145 records · Page 8Linked to original sources

Precise anatomic configuration changes in the first ray of the hallux valgus foot.

To detect precise anatomical configuration of the first ray in feet with hallux valgus, a two-dimensional coordinate system was devised for evaluation of a weight-bearing dorsoplantar radiograph. The radiographs, taken from 229 feet of 114 patients with symptomatic hallux valgus and 94 normal feet, were investigated. A comparative study showed the first metatarsal head of a foot with hallux valgus was located on the medial side of that of the normal foot and the base of the proximal phalanx of the hallux valgus foot was located on the same point of that of the normal foot. Lateral translation of the base of the proximal phalanx occurred only in cases with overlap toes. Our study shows that subluxation of the metatarsophalangeal joint in hallux valgus is primarily caused by metatarsus primus varus. This study indicated that first metatarsal osteotomies should be given the first priority in consideration for bunion surgery, because these procedures could move the first metatarsal heads laterally in a more normal position.

Adolescent↗

Time-dependent nephrotoxicity associated with daily administration of cisplatin in mice.

The chronopharmacokinetics and chronopharmacodynamics of cisplatin were studied in a mouse model to reveal the mechanisms of dosing time-dependent nephrotoxicity induced by daily administration. Chronotoxicity was tested by daily intraperitoneal injections of cisplatin (6mg kg(-1)) for 5 days at four time points (04:00, 10:00, 16:00 and 22:00h) in BALB/c mice (n = 6 in each group). After following the changes in body weight, serum concentrations of blood urea nitrogen (BUN) and creatinine obtained on day 6 were compared. The results showed diurnal variations in cisplatin toxicity, with the 04:00 and 16:00h time points the best and the worst, respectively. We then measured platinum concentrations in blood, liver and kidney and compared the results of the 04:00 and 16:00 h groups (n = 4 in each group). Kidney sensitivity to cisplatin alone, lipopolysaccharide (LPS) alone, cisplatin with LPS and saline (control) were also measured using a tissue culture system (a measurement system of interleukin-6 (IL-6) production) between the 04:00 and the 16:00 h groups (n = 4 in each group). These results showed no significant difference in platinum accumulation between the two groups. IL-6 production was higher in the 16:00 h group than in the 04:00 h group after saline injection alone (P < 0.05). Cisplatin treatment alone did not increase IL-6 production. However, IL-6 levels were markedly augmented by cisplatin with LPS. In conclusion, chrononephrotoxicity induced by daily cisplatin administration does not only depend on cisplatin accumulation, but might also depend on kidney sensitivity to diurnal variations in inflammatory reaction without direct cisplatin toxicity.

Animals↗

Centromere/kinetochore localization of human centromere protein A (CENP-A) exogenously expressed as a fusion to green fluorescent protein.

Three human centromere proteins, CENP-A, CENP-B and CENP-C, are a set of autoantigens specifically recognized by anticentromere antibodies often produced by patients with scleroderma. Microscopic observation has indicated that CENP-A and CENP-C localize to the inner plate of metaphase kinetochore, while CENP-B localizes to the centromere heterochromatin beneath the kinetochore. The antigenic structure, called "prekinetochore", is also present in interphase nuclei, but little is known about its molecular organization and the relative position of these antigens. Here, to visualize prekinetochore in living cells, we first obtained a stable human cell line, MDA-AF8-A2, in which human CENP-A is exogenously expressed as a fusion to a green fluorescent protein of Aequorea victoria. Simultaneous staining with anti-CENP-B and anti-CENP-C antibodies showed that the recombinant CENP-A colocalized with the endogenous CENP-C and constituted small discrete dots attaching to larger amorphous mass of CENP-B heterochromatin. When the cell growth was arrested in G1/ S phase with hydroxyurea, CENP-B heterochromatin was sometimes highly extended, while the relative location between GFP-fused CENP-A and the endogenous CENP-C was not affected. These results indicated that the fluorescent CENP-A faithfully localizes to the centromere/kinetochore throughout the cell cycle. We then obtained several mammalian cell lines where the same GFP-fused human CENP-A construct was stably expressed and their centromere/kinetochore is fluorescent throughout the cell cycle. These cell lines will further be used for visualizing the prekinetochore locus in interphase nuclei as well as analyzing kinetochore dynamics in the living cells.

Animals↗

cDNA cloning of the Cry1Aa receptor variants from Bombyx mori and their expression in mammalian cells.

We cloned cDNA of three variants of BtR175, a putative Bombyx mori receptor for Bacillus thuringiensis Cry1Aa delta-endotoxin by PCR. These variants were likely to be allelic to BtR175. cDNA of BtR175b, the most distant variant from BtR175, was introduced into mammalian cells. BtR175b protein was expressed in the plasma membrane of the cells and showed binding activity to Cry1Aa.

Alternative Splicing↗

Failure of probucol to prolong survival in salt-loaded stroke-prone spontaneously hypertensive rats.

We examined the effect of probucol, a lipid-lowering agent with strong antioxidant properties, on neurological events and survival in stroke-prone spontaneously hypertensive rats (SHRSP). Rapid onset of stroke was induced by maintaining the animals on 1% NaCl solution in place of drinking water. Probucol (10 or 30 mg/kg/day), both of which doses are therapeutic in humans was given by gastric gavage once daily to salt-loaded SHRSP. Animals receiving vehicle were used as controls. Probucol did not influence the elevation of blood pressure. Although probucol did not improve the survival rate of salt-loaded SHRSP, 30 mg/ kg/day of probucol slightly but significantly delayed the development of neurological events (p=0.0235 by generalized Wilcoxon test). However, a high dose of probucol (100 mg/kg/day) did not change the survival or neurological events of salt-loaded SHRSP. These results suggest that probucol may be protective against the development of neurological events, but is not preventive for the progression of stroke in SHRSP.

Animals↗

Complete occulusion of left renal artery in pediatric-onset Takayasu's arteritis.

A-16-year-old male adolescent with a 4-year history of protean clinical manifestations such as fever, abdominal pain, back pain, erythema nodosum and uveitis developed complete occlusion of left renal artery. Although he had been suspicious of having an autoimmune disease and treated with prednisolone, a definite diagnosis was not made. Finally, an angiography disclosed stenosis of abdominal aorta just beneath the origin of the renal arteries as well as complete occlusion of left renal artery. It has been reported that pediatric-onset Takayasu's arteritis sometimes shows protean clinical manifestations as in ours. Takayasu's arteritis should be considered as one of the underlaying disease, when a child develops protean manifestations suggesting an autoimmune disease.

Adolescent↗

Purification, identification and phosphorylation of annexin I from rat liver mitochondria.

Annexin was purified from rat liver mitochondria to an apparent homogeneity with a molecular weight of 35 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified mitochondrial annexin (AXmito) was identified as annexin I by an immunoblot analysis using anti-annexin I antibody. The inhibitory effect of AXmito I on porcine pancreatic phospholipase A2 activity was as potent as that of bovine lung annexin I. The presence of annexin I in mitochondria was confirmed by an electron-microscopic study. AXmito I was shown to be phosphorylated by intrinsic protein tyrosine kinases on its tyrosine residues. This annexin was also phosphorylated by protein kinase C.

Animals↗

Effect of segmental transcatheter arterial chemoembolization on branched chain amino acids and tyrosine ratio in patients with hepatocellular carcinoma.

The effect of segmental transcatheter arterial chemoembolization (TAE) on serum amino acid levels and liver function were studied in 23 patients with HCC associated with hepatitis virus C (22 patients) or alcoholism (1 patient), with compensated liver cirrhosis (Child A 18 patients, Child B 5 patients). Serum levels of branched-chain amino acids (BCAA), tyrosine, branched-chain amino acids to tyrosine ratio (BTR), ammonia, total bilirubin and albumin, and prothrombin times were measured before and after TAE (24 h, 7 and 14 days). The BTR was increased significantly 24 h after TAE (p<0.001) and gradually decreased to pre-TAE levels. Serum tyrosine levels decreased at 24 h after TAE (p<0.005) and later increased. Serum BCAA levels increased slightly at 7days after TAE and were decreased at 14 days after TAE. This results indicated that the increased BTR was due primarily to the decreased tyrosine level at 24 h after TAE. Serum ammonia levels gradually decreased after TAE and the prothrombin time and serum levels of total bilirubin and albumin were not significantly changed. In this study, segmental TAE had little influence on liver function, and the BTR unexpectedly increased at 24 h after TAE. These results suggest that segmental TAE has minimal side effects and may have a beneficial effect on amino acid metabolism.

Adult↗

Acute effect of cadmium-metallothionein on glucose and amino acid transport across the apical membrane of the rabbit proximal tubule perfused in vitro.

Acute as well as chronic exposure of cadmium (Cd) leads to proximal tubule injury. The exact cellular mechanism of this disorder and whether there is a contribution of cadmium-metallothionein (Cd-MT), a binding protein of Cd, remain unclear. We perfused isolated S2 segments of rabbit nephron, and the deflections of transmural voltage (DeltaV(t)) and apical membrane voltage (DeltaV(a)) on elimination of glucose or alanine from the perfusate were measured for the parameters of activity of Na(+)-glucose and Na(+)-amino acid cotransporters. The effects of Cd-MT or CdCl(2) to either bath or lumen for 10 min on these parameters were examined. We also measured the lumen-to-bath [(14)C]glucose flux. Addition of Cd-MT to lumen suppressed glucose- or alanine-dependent DeltaV(t) and DeltaV(a), as well as baseline V(t) and basolateral membrane voltage (V(b)), at approximately 10 min. [(14)C]glucose flux was inhibited by Cd-MT to lumen. The effects of Cd-MT to bath and CdCl(2) to either lumen or bath were 100-fold less potent than that of Cd-MT to lumen. Luminal Cd-MT immediately suppressed the glucose-dependent DeltaV(a), whereas the baseline V(a) and V(t) were unchanged. The early effect of luminal Cd-MT was simulated by addition of 10(-4) M phloretin. Addition of 10(-4) M ouabain to the bath simulated the later effect of Cd-MT. The protection of SH group by dithiothreitol prevented the early effect of Cd-MT, but not the later effect. We concluded that Cd-MT initially acts directly on Na(+)-glucose and Na(+)-amino acid cotransporters from the lumen by attacking SH group, followed by the later inhibition of Na(+)-K(+)-ATPase after entering the cell from the apical membrane.

Alanine↗

Efficacy of cholesterol-lowering treatment in Japanese elderly patients with coronary artery disease and normal cholesterol level using 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor.

The clinical benefit of cholesterol-lowering treatment is unknown in the Japanese elderly in whom the prevalence of morbidity and mortality related to coronary artery disease are known to be low. To evaluate the efficacy of cholesterol-lowering treatment with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor in Japanese elderly patients with documented coronary artery disease, 121 patients with serum cholesterol > or = 150 mg/dl prospectively received HMG-CoA reductase inhibitor, and 271 patients undergoing cholesterol-lowering treatment based on dietary therapy alone served as historical controls. The 143 elderly patients age > or = 65 years in the 2 groups had similar baseline serum total cholesterol level (201 +/- 30 vs 202 +/- 31 mg/dl), age (71 +/- 4 vs 70 +/- 4 years), proportion of men (37/53 vs 64/90), number of diseased vessels (1.7 +/- 0.9 vs 1.5 +/- 1.0), and incidences of other classical coronary risk factors, including hypertension, diabetes mellitus, smoking, obesity and family history of coronary artery disease. In all 392 patients, similar trends were observed, including serum total cholesterol level (208 +/- 33 vs 201 +/- 34 mg/dl). With HMG-CoA reductase inhibitors, serum total cholesterol level was reduced by 14% in the elderly subjects and by 13% in all patients. During the follow-up of approximately 3 years, cardiac events occurred in 5 patients (one elderly) in the treatment group and 38 patients (12 elderly) in the control group. Kaplan-Meier survival estimates revealed a higher event-free survival rate with HMG-CoA reductase inhibitors in the elderly subjects (98% vs 85%, p < 0.05) and in all patients (94% vs 86%, p < 0.05). Cox proportional hazard modeling also demonstrated a significant reduction in risk for cardiac events with drug therapy (relative risk 0.32, p < 0.05), in addition to the number of diseased vessels (relative risk 1.8, p < 0.01). In contrast, no additional risk was observed with advancing age. Cholesterol-lowering treatment with HMG-CoA reductase inhibitors is effective to improve the prognosis of Japanese elderly patients, including those with normal serum cholesterol level.

Anticholesteremic Agents↗

[Clinical usefulness of diffusion-weighted magnetic resonance imaging in patients with ischemic cerebrovascular disease].

Diffusion-weighted magnetic resonance imaging was performed to determine the detectability of ischemic changes in patients with ischemic cerebrovascular disease. We retrospectively reviewed 103 patients with symptoms suggestive of ischemic cerebrovascular disease. All patients underwent computed tomography, routine magnetic resonance imaging, and diffusion-weighted imaging. Of 103 patients, 18 were imaged within 3 hours after onset, 57 were imaged between 3 and 24 hours, and 29 were imaged between 24 and 144 hours. Eighty-eight patients were diagnosed as ischemic cerebrovascular disease. Magnetic resonance imaging was performed at a 1.0 Tesla clinical machine using single-shot spin-echo/echo-planar imaging sequence. In each case, three sets of DWI with motion-probing gradient pulses in the x, y, and z directions were taken. The detectability of ischemic changes of each imaging modality was compared. DWI detected ischemic changes in 83 of 88 cases with clinical diagnoses of cerebral ischemia(sensitivity; 94.3%). In contrast, DWI showed negative findings in 15 of the 15 patients with diagnoses other than cerebral ischemia(selectivity; 100.0%). DWI detected ischemic changes in 16 out of 18 patients(88.6%) within 3 hours after the onset. In contrast, T 2-weighted image did not detect any ischemic changes in the same period. These results suggest that DWI is considered to be highly useful for the early diagnosis of cerebral ischemia.

Adolescent↗

[A case of cardiogenic cerebral embolism with successful recanalization: apparent diffusion coefficient analysis for prediction of reversible cerebral ischemia].

A 54-year-old woman complaining of left hemiplegia was transferred to our hospital. Computed tomography on admission demonstrated normal. Electrocardiogram showed atrial fibrillation. Cerebral blood flow (CBF) was decreased in both the cortex and the perforator territory of the right middle cerebral artery (MCA), whereas the apparent diffusion coefficient (ADC) in the cortex was normal. Digital subtraction angiography (DSA) revealed an occlusion of the right MCA (M 1 proximal) with collateral flow from the right anterior cerebral artery (ACA) to the territory of the right MCA. After intra-arterial injection of tissue-plasminogen activator (t-PA), DSA showed partial recanalization, and the symptoms of the patient improved considerably. Five days after that, the patient deteriorated again and showed disturbance of consciousness and left hemiplegia. In this episode, both CBF and ADC in the cortex of the right MCA were decreased. DSA revealed an occlusion of the right internal carotid artery (ICA) and collateral flow from the right ACA to the territory of the right MCA disappeared. After intra-arterial injection of t-PA, DSA showed partial recanalization with collateral flow from the right ACA, and the symptoms of the patient improved. DSA 5 weeks after onset showed complete recanalization of both the right MCA and the ICA. The patient was diagnosed as both mitral and aortic stenosis and regurgitation (MSR + ASR) and underwent an operation for both mitral and aortic value replacement. She was discharged with no neurological deficit 4 months after onset. ADC analysis is especially useful for the prediction of reversible ischemic damage and the prevention of hemorrhagic transformation and fatal edema in acute ischemic stroke.

Angiography, Digital Subtraction↗

[The radiographic report of soft tissue tumor on the legs in a case of cutaneous polyarteritis nodosa].

A 55-year-old male was admitted to our hospital because of arthralgia, rash, and painful tumor in the legs. On admission, skin lesions involving dark erythematous macules and a tender mass of 3 by 5 cm were present. Laboratory findings included hemoglobin of 11.2 g/dl, white blood cell count of 6200/microliter, erythrocyte sedimentation rate (ESR) of 88 mm/hour, and normal results of renal function tests. Hepatitis B surface antigen, anti-nuclear antibody (ANA), and perinuclear pattern antineutrophil cytoplasmic autoantibody (ANCA) were negative. A T 1-weighted magnetic resonance image (MRI) showed iso-intensity areas that increased in intensity on T 2-weighted images of the M. gastrocnemius. The angiographic appearance of tumor staining with some degree of luminal irregularity in the posterior tibial artery suggested a diagnosis of soft tissue neoplasm. Biopsy specimens of the right leg lesion were consistent with necrotizing arteritis of both small and medium-sized vessels. Treatment with prednisolone and cyclophosphamide resulted in the disappearance of the skin lesions and the improvement of laboratory data. At first, classical polyarteritis nodosa was considered histologically. However, lesions were limited to skin, muscles, and joints, and there has been no evidence of systemic disease for 1.5 years; consequently, cutaneous form of polyarteritis nodosa was diagnosed. Reports of soft tissue tumors on the legs of patients with polyarteritis nodosa are quite rare. The interesting radiographic findings of cutaneous polyarteritis nodosa were reported.

Cyclophosphamide↗

[A case of acute pancreatitis that occurred after an operation of the lumbar spine].

A 56-year-old female, who had been suffering from heart failure and diabetes mellitus, underwent posterior instrumentation in the prone position and anterior interbody fusion in the right lateral decubitus position for pyogenic spondylitis between the fourth and fifth lumbar spine under general and epidural anesthesia. We induced hypotensive anesthesia by using continuous infusion of dopamine, prostaglandin E1 and nitroglycerin in order to prevent heart failure and reduce the blood loss. After the operation, the patient complained of upper abdominal pain, nausea and vomiting. We found high levels of serum amylase and other pancreatic enzymes. The massive gas of small intestine was pooled in abdominal X-P, and the pancreatic head was slightly swollen in abdominal CT and US. Therefore we came to the diagnosis of postoperative acute pancreatitis. We administered a single bolus intravenous infusion of ulinastatine and continuous venous infusion of gabexate mesilate. As the serum amylase level gradually decreased, the patient improved. We suspect that postoperative pancreatitis was due to invasive anesthetic and surgical stress on the patient who had had pancreatitis in the preoperative period.

Anesthesia, Epidural↗