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Biomedical subjects

N Nagano

Publications and source records attributed to N Nagano.

At least 37 records · Page 2Linked to original sources
PubMed2000

Coronary artery bypass grafting in patient with malignant neoplasm. Efficacy of coronary artery bypass grafting on beating heart.

OBJECTIVE: Coronary artery bypass grafting (CABG) prior to noncardiac major surgery has effectively decreases short- and long-term mortality related to coronary ischemia. Coronary artery bypass on the beating heart is conducted to avoid the risk of cardiopulmonary bypass and it has contribute to shorten recovery time. METHODS: Subjects were 19 patients with malignant neoplasm for whom a retrospective chart review was made between Jan. 1, 1992 and July 31, 1998. In the early phase of this study, between Jan. 1, 1992, and Dec. 31, 1997, CABG was performed using cardiopulmonary bypass, and late phase, between Jan. 1, 1998, and July 1, 1998, CABG was done on the beating heart without cardiopulmonary bypass. RESULTS: Conventional CABG was performed in 12 patients with neoplasms (10 male and 2 female, age 64.7 +/- 6.1 years), and CABG on the beating heart was performed in 7 patients (6 male and 1 female, age 68.0 +/- 7.5 years). Fewer number of bypass grafts were made in the beating-heart CABG group (1.3 +/- 0.5 in beating-heart CABG versus 3.9 +/- 1.1 in conventional CABG). No cardiac events occurred in either group during the surgery for malignant tumors. The operative interval between CABG and cancer surgery was significantly shorter in the beating-heart CABG group (21.8 +/- 17.9 days in beating-heart CABG versus 53.5 +/- 42.9 days in conventional CABG, p < 0.05). CONCLUSION: Patients with severe coronary artery disease and malignant neoplasms should undergo coronary artery revascularization before the neoplasm is treated. CABG on the beating-heart was safe and effective procedure in those with malignant neoplasms.

Aged↗
PubMed2000

Surgical management of unstable patients in the evolving phase of acute myocardial infarction.

BACKGROUND: Acute myocardial infarction (AMI) can be treated with thrombolysis or coronary catheter intervention; surgical treatment--coronary artery bypass grafting (CABG)--is reserved for the patients in whom other procedures have failed. We performed CABG in 47 patients during the evolving phase of AMI, and analyzed their short-term and long-term results. METHODS: Preoperative, intraoperative, and postoperative data were analyzed in patients who underwent emergency CABGs for AMI between January 1, 1992, and July 31, 1998. CABGs performed more than 7 days after AMI were excluded from this study. RESULTS: The subjects were 47 patients (33 males and 14 females) with AMI who were treated by emergency CABG. Intraaortic balloon pumping was used in 44 cases and percutaneous circulatory pulmonary support was used in 3 cases. The mean interval between the onset of AMI and surgery was 27.4 +/- 27.9 hours. The mean number of bypass grafts was 3.0 +/- 1.1, and at least 1 arterial conduit was used in 45 cases (95.7%). Aortic clamp time, pump time, and operative time were 64.7 +/- 31.7, 117.3 +/- 55.2, and 313.2 +/- 84.8 minutes, respectively. IABP or percutaneous cardiopulmonary support were removed in the intensive care unit (ICU) 30.0 +/- 28.9 hours after CABG. The patients were extubated 41.4 +/- 40.5 hours after surgery, remained in ICU for 4.7 +/- 2.7 days, and were discharged from the hospital after 27.0 +/- 22.5 days. Three patients died from multiorgan failure related to postoperative sepsis, and 8 cases of major complications were observed. The actuarial 5-year survival rate of the patients treated with CABG was 83.0%. CONCLUSIONS: Surgical treatment in the unstable patients after AMI can be performed with acceptable risk. Arterial revascularization may contribute to improvement in long-term results.

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PubMed2000

Daily intermittent decreases in serum levels of parathyroid hormone have an anabolic-like action on the bones of uremic rats with low-turnover bone and osteomalacia.

The calcium receptor agonist (calcimimetic) compound NPS R-568 causes rapid decreases in circulating levels of parathyroid hormone (PTH) in rats and humans. We hypothesized that daily intermittent decreases in serum PTH levels may have different effects on bone than do chronically sustained decreases. To test this hypothesis, we compared two NPS R-568 dosing regimens in rats with chronic renal insufficiency induced by two intravenous injections of adriamycin. Fourteen weeks after the second adriamycin injection, creatinine clearance was reduced by 52%, PTH levels were elevated approximately 2.5-fold, and serum 25(OH)D3 and 1,25(OH)2D3 levels were reduced substantially. Treatment by daily per os gavage, which decreased PTH levels intermittently, or continuous subcutaneous infusion, which resulted in a sustained suppression of serum PTH levels, then began for 8 weeks. Despite the hyperparathyroidism, the adriamycin-injected rats developed a low-turnover bone lesion with osteomalacia (fourfold increase in osteoid volume in the proximal tibial metaphysis) and osteopenia (67% decrease in cancellous bone volume and an 18% reduction in bone mineral density at the distal femur). Daily administered (but not infused) NPS R-568 significantly increased cancellous bone volume solely by normalizing trabecular thickness, and increased femoral bone mineral density by 14%. These results indicate that daily intermittent, but not sustained, decreases in PTH levels have an "anabolic-like" effect on bones with a low-turnover lesion in this animal model of chronic renal insufficiency.

Aniline Compounds↗
PubMed2000

Calcimimetic NPS R-568 prevents parathyroid hyperplasia in rats with severe secondary hyperparathyroidism.

UNLABELLED: Calcimimetic NPS R-568 prevents parathyroid hyperplasia in rats with severe secondary hyperparathyroidism. BACKGROUND: Secondary hyperparathyroidism (secondary HPT) in chronic renal insufficiency (CRI) is characterized by multiglandular hyperplasia. METHODS: In this study, we investigated the effects of the calcimimetic NPS R-568 on the parathyroid gland in rats with CRI induced by ligation of the renal arteries and severe secondary HPT induced by dietary phosphorus loading. Six days after surgery, high-phosphorus diet feeding was started, and NPS R-568 was administered to the rats for 56 days either by daily gavage (30 or 100 micromol/kg) or by continuous subcutaneous infusion (20 micromol/kg. day). RESULTS: After 54 days, serum PTH levels in vehicle-treated CRI rats were 1019 vs. 104 pg/mL in sham-operated controls. Infusion of NPS R-568 maintained serum PTH at levels comparable with those of sham-operated controls, whereas daily gavage also prevented much of the increase in CRI controls and decreased PTH levels intermittently in a dose-dependent fashion. Parathyroid gland enlargement was caused predominantly by hyperplasia. Total cell number per kg body wt was 3.5-fold higher in vehicle-treated CRI rats than in sham-operated controls. Both infusion and high-dose gavage of NPS R-568 completely prevented the increase in parathyroid cell number. CONCLUSION: These results demonstrate that the calcimimetic compound NPS R-568 can prevent both the increase in serum PTH levels and parathyroid hyperplasia in rats with CRI and severe secondary HPT. Moreover, these changes occurred despite decreases in serum 1, 25(OH)2D3 and increases in serum phosphate, suggesting a dominant role for the calcium receptor in regulating parathyroid cell proliferation.

Aniline Compounds↗
PubMed2000

Characteristic changes in carbohydrate profile in the kidneys of hereditary nephrotic mice (ICGN strain).

The ICR-derived glomerulonephritis (ICGN) mice consist of heterozygous and homozygous groups and are considered to be a good model for human idiopathic nephrotic syndrome. To reveal changes in cell-surface carbohydrate construction, 24 lectins were applied to kidney sections of 10-, 30- and 50-week-old male heterozygous and homozygous ICGN mice and age-matched male ICR mice. Bandeiraea simplicifolia lectin-I (BSL-I), which specifically binds to alpha-D-galactopyranosyl groups, showed positive staining in the glomeruli of ICGN mice, but not in those of ICR mice. Positive BSL-I staining was observed only in distal tubules of homozygous ICGN mice. Lectin blotting for BSL-I demonstrated characteristic glycoproteins (45, 58 and 64 kD) in ICGN but not in ICR mice, and the levels of these molecules augmented in homozygous ICGN mice with the progression of renal failure. Moreover, succinylated wheat germ agglutinin, Dolichos biflorus agglutinin, Aleuria aurantia lectin and Ulex europaeus agglutinin-I showed positive staining only in the glomeruli of homozygous ICGN mice, but not in those of heterozygous ICGN or ICR mice. The staining intensities of Ricinus communis agglutinin-I, Phaseolus vulgaris agglutinin-E and -L, Lens culinaris agglutinin and Erythrina cristagalli agglutinin (ECL) in the glomeruli of homozygous ICGN mice were stronger than those of heterozygous ICGN and ICR mice. In conclusion, lectin histochemistry provided useful information for the diagnosis and prognosis of nephrotic lesions. Characteristic BSL-I binding glycoproteins may be pathogenic factors which cause renal disease in ICGN mice and are good tools to investigate the molecular mechanism of renal disorders in ICGN mice.

Animals↗
PubMed2000

Coronary artery bypass grafting in the elderly.

BACKGROUND AND METHODS: The incidence of coronary artery bypass grafting (CABG) in elderly patients has been increasing. We retrospectively analyzed the results of CABG performed at Shin-Tokyo Hospital between January 1, 1991, and December 31, 1998. Preoperative, perioperative, and follow-up data of patients > or = 75 years old (group E, n = 190) were collected, and compared with those of patients < 75 years old (group Y, n = 1,380). RESULTS: Female gender, emergent CABG, preoperative balloon pumping use, cardiogenic shock, hypertension, and preoperative cerebral vascular accident were significantly more frequent in group E (p < 0.05). CABG was completed without any significant differences, except for less frequent use of the bilateral internal mammary artery (p < 0.01), more frequent use of the saphenous vein (p < 0.005), and a greater incidence of blood transfusion in group E (p < 0.0001). The postoperative course required longer intubation, ICU stay, and postoperative hospital stay in group E (p < 0.001), and was more frequently associated with major complication (p < 0.0001) and in-hospital death (p < 0.05). During the mean follow-up of 2.7 years (maximum 6.9 years), the actuarial 5-year survival of groups E and Y were 84.3% and 92.5% (p < 0.01), respectively, excluding in-hospital mortality. The actuarial 5-year cardiac event-free rates were 79.9% in group E and 79.7% in group Y, showing no significant difference. CONCLUSIONS: CABG in the elderly carries certain surgical risks. However, the long-term cardiac event-free rate after CABG in the elderly was almost the same as that of younger patients. Inferior long-term survival in the elderly was most likely due to the biological nature of aging.

Aged↗
PubMed2000

Off-pump coronary artery bypass: early results.

BACKGROUND: Coronary artery bypass grafting (CABG) on a beating-heart has gained the attention of cardiac surgeons and shown favorable initial results. However, only a few follow-up results have been reported. We report herein our one-year experiences of off-pump CABG performed at Shin-Tokyo Hospital. METHODS: Retrospective chart review was performed for patients who underwent off-pump CABG and conventional isolated CABG between 01/01/98 and 12/31/98. Preoperative, perioperative, and follow-up data were collected. RESULTS: Among 315 cases of isolated CABG, 94 cases were off-pump CABG (male/female 69/25, mean age 67.7). Mean number of distal anastomoses performed by off-pump CABG was 1.7 +/- 0.7 (42 cases of single-vessel revascularization and 52 cases of more than double- vessel revascularization). In off-pump CABG, there were no hospital deaths and 6 major complications including 2 incidences of perioperative myocardial infarction. Postoperative angiography before hospital discharge was performed in 56 patients (59.6%, 98 anastomosis) and revealed 5 occlusions, giving a graft patency rate of 94.9%. During the follow-up (11.4 +/- 4.1 months), there was 1 late non-cardiac death and 11 cardiac events. The event-free rate at 18 months was 94.0% in off-pump CABG, showing no significant difference from the event-free rate after conventional CABG (94.0% at 18 months, p = 0.135). Follow-up angiography was performed in 21 patients (33 anastomoses) at a mean interval of 3.6 months and showed 4 graft occlusions, giving a patency rate of 92.7%. CONCLUSION: Both hospital and early results of off-pump CABG were acceptable. Off-pump CABG can be safely performed in selected patients.

Adult↗
PubMed2000

Ruptured aortic dissecting aneurysm in Turner's syndrome: a case report and review of literature.

Cardiovascular malformations are frequently observed in Turner's syndrome. Bicuspid aortic valve and coarctation of the aorta are commonly associated with Turner's syndrome whereas aortic dissection is rare but its rupture results in death. We experienced a case of ruptured dissecting aneurysm (Stanford type A) in a 30-year-old female with Turner's syndrome. Emergent total arch replacement was performed successfully. A literature review revealed 32 cases of aortic dissection in patients with Turner's syndrome, including 15 cases of rupture. However, survival after rupture was reported only two cases. To our knowledge, this report descries the third known case of successful surgical management of ruptured aortic dissection in Turner's syndrome.

Adult↗
PubMed2000

Off-pump total arterial bypass grafting using bilateral mammary, gastroepiploic, and radial artery.

The indication for off-pump coronary artery bypass grafting (CABG) have been expanded as development of the off-pump device has progressed. We present a case of four-vessel revascularization with total arterial graft under a beating heart. All conduits were in situ or composite, and bypass was performed with aorta non-touch technique. Off-pump bypass using in situ quadruple arterial conduits may contribute to a reduction of incidence of perioperative strokes and reduction of the postoperative cardiac events.

Aged↗
PubMed1999

Strong hydrophobic nature of cysteine residues in proteins.

The differences between disulfide-bonding cystine (Cys_SS) and free cysteine (Cys_SH) residues were examined by analyzing the statistical distribution of both types of residue in proteins of known structure. Surprisingly, Cys_SH residues display stronger hydrophobicity than Cys_SS residues. A detailed survey of atoms which come into contact with the sulfhydryl group (sulfur atom) of Cys_SH revealed those atoms are essentially the same in number and variety as those of the methyl group of isoleucine, but are quite different to those of the hydroxyl group of serine. Moreover, the relationships among amino acids were also determined using the 3D-profile table of known protein structures. Cys_SH was located in the hydrophobic cluster, along with residues such as Met, Trp and Tyr, and was clearly separated from Ser and Thr in the polar cluster. These results imply that free cysteines behave as strongly hydrophobic, and not hydrophilic, residues in proteins.

Algorithms↗
PubMed1999

Motif-based searching in TOPS protein topology databases.

MOTIVATION: TOPS cartoons are a schematic ion of protein three-dimensional structures in two dimensions, and are used for understanding and manual comparison of protein folds. Recently, an algorithm that produces the cartoons automatically from protein structures has been devised and cartoons have been generated to represent all the structures in the structural databank. There is now a need to be able to define target topological patterns and to search the database for matching domains. RESULTS: We have devised a formal language for describing TOPS diagrams and patterns, and have designed an efficient algorithm to match a pattern to a set of diagrams. A pattern-matching system has been implemented, and tested on a database derived from all the current entries in the Protein Data Bank (15,000 domains). Users can search on patterns selected from a library of motifs or, alternatively, they can define their own search patterns. AVAILABILITY: The system is accessible over the Web at http://tops.ebi.ac.uk/tops

Algorithms↗
PubMed1999

The calcium receptor and calcimimetics.

Parathyroid cells can sense small changes in plasma Ca2+ levels by virtue of a cell surface Ca2+ receptor. Calcimimetics are newly synthesized compounds that act as agonists or positive allosteric modulators at the Ca2+ receptor and can suppress parathyroid hormone secretion. The first-generation calcimimetic, NPS R-568, has undergone clinical trials in primary hyperparathyroidism and in hyperparathyroidism secondary to chronic renal insufficiency. The data accumulated so far demonstrate that calcimimetics have potential as therapeutic agents for hyperparathyroidism and related bone diseases such as osteitis fibrosa.

Aniline Compounds↗
PubMed1999

Barrel structures in proteins: automatic identification and classification including a sequence analysis of TIM barrels.

Automated methods for identifying and characterizing regular beta-barrels from coordinate data have been developed to analyze and classify various kinds of barrel structures based on geometric parameters such as the barrel strand number (n) and shear number (S). In total, we find 1,316 barrels in the January 1998 release of Protein Data Bank. Of 1,316 barrels, 1,277 barrels had an even shear number, corresponding to 50 nonhomologous families. The (beta alpha)8 triose phosphate isomerase (TIM) barrel (n = 8, S = 8) fold has the largest number of apparently nonhomologous entries, 16, although the trypsin like antiparallel (n = 6, S = 8) barrels (representing only three families) are the most common with 527 barrels. Of all the protein families that exhibit barrel structures, 68% are found to be various kinds of enzymes, the remainder being binding proteins and transport membrane proteins. In addition, the layers of side chains, which form the cores of barrels with S = n and S = 2n, are also analyzed. More sophisticated methods were developed for detecting TIM barrels specifically, including consideration of the amino acid propensities for the side chains that form the layers. We found that the residues on the outside of the eight stranded parallel beta-barrel, buried by the alpha-helices, are much more hydrophobic than the residues inside the barrel.

Hydrogen Bonding↗
PubMed1999

Activation of Ca(2+)-dependent K(+) current by nordihydroguaiaretic acid in porcine coronary arterial smooth muscle cells.

The effects of nordihydroguaiaretic acid (NDGA), a lipoxygenase inhibitor and an antioxidant, on membrane currents were examined in single smooth muscle cells isolated from porcine coronary artery. Spontaneous transient outward currents (STOCs) recorded at -30 mV were markedly enhanced by NDGA (>/=10 microM). Pretreatment with caffeine and ryanodine abolished STOCs and reduced NDGA-induced increase in outward current at -30 mV by approximately 60%. NDGA showed dual action on an outward current elicited by step depolarization from -60 to 0 mV: inhibition and enhancement at concentrations of 3 and >/=10 microM, respectively. In the presence of Cd(2+), the inhibition of outward current by NDGA disappeared and the enhancement remained. NDGA inhibited both the voltage-dependent Ca(2+) channel current (IC(50) = 2.5 microM) and the delayed rectifier K(+) current (IC(50) = 9.8 microM). The NDGA-induced enhancement of STOCs and outward currents on depolarization was abolished by 100 nM iberiotoxin but was not affected by glibenclamide or apamin. Under current clamp mode, 30 microM NDGA significantly hyperpolarized myocytes. The application of lipoxygenase inhibitors (caffeic acid and esculetin), a cyclooxygenase inhibitor (indomethacin), antioxidants (ascorbic acid and erythorbic acid), and structural-related compounds of NDGA (catechol and dopamine) did not enhance K(+) currents. These results indicate that the opening of the large conductance Ca(2+)-dependent K(+) channel by NDGA, which is independent of its lipoxygenase inhibition or antioxidant effect, results in membrane hyperpolarization.

Animals↗
PubMed1999

Coronary artery aneurysm associated with fistula in adults: collective review and a case report.

Coronary artery fistulae (CAF) are infrequent congenital anomalies. The combination of coronary artery aneurysms and coronary artery fistulae (coronary artery aneurysm associated with fistula, CAAAF) is extremely rare, and only 50 cases, including the current case, have been reported. Coronary artery fistulae may result in coronary ischemia, congestive heart failure, and endocarditis. Complications of coronary artery aneurysms include thrombosis, distal emboli, and aneurysm rupture. Aneurysm repair, fistulous closure and/or coronary artery bypass grafts are definite treatments for CAAAF. We present here a 72-year-old female with CAAAF. Furthermore, all reported CAAAF cases are reviewed.

Aged↗
PubMed1999

Emergency off-pump coronary artery bypass grafting under a beating-heart.

BACKGROUND: Coronary artery bypass grafting (CABG) on a beating heart has been successfully performed for high risk patients, and is known to be less invasive than conventional CABG using cardiopulmonary bypass (CPB). We expanded the indication of beating-heart CABG in patients requiring emergency coronary revascularization. METHODS: A retrospective chart review was performed for patients who had undergone emergency CABG on a beating heart (EM-BH group), elective CABG on a beating heart (Elective-BH group) and emergency CABG under CPB (EM-CPB group), between January 1, 1997 and June 30, 1998. RESULTS: Four cases (1 male and 3 females with a mean age of 67.8 +/- 5.4) in the EM-BH group, 67 cases (48 males and 19 females with mean age of 67.3 +/- 7.8) in the Elective-BH group, and 41 cases (29 males and 12 females with mean age of 63.3 +/- 10.4) in the EM-CPB group were analyzed. The number of the grafts was 1.75 +/- 0.50 in EM-BH group, 1.37 +/- 0.55 in the Elective-BH group, and 2.95 +/- 1.07 in the EM-CPB group. The intubation period, ICU stay, and the postoperative hospital stay were significantly shorter in the EM-BH group (6.0 hours intubation, 1.5 days ICU stay, and 11.5 days postoperative hospital stay) and Elective-BH group (6.8 +/- 11.0 hours intubation, 1.6 +/- 1.5 days ICU stay, and 12.7 +/- 5.2 days postoperative hospital stay) than in the EM-CPB group (20.1 +/- 22.5 hours intubation, 3.6 +/- 2.4 days ICU stay, and 21.8 +/- 14.9 days postoperative hospital stay). CONCLUSION: The postoperative recovery period for EM-BH patients was almost the same as that for elective cases of beating-heart CABG, and was significantly shorter than that of conventional emergency CABG under CPB. Selected patients with coronary ischemia can be safely treated by beating-heart surgery.

Aged↗