Search PubMed⌕ Search

Biomedical subjects

Y Sakamoto

Publications and source records attributed to Y Sakamoto.

At least 415 records · Page 23Linked to original sources
PubMed1992

Full-thickness dynamic cardiomyoplasty of the left ventricle with free revascularized latissimus dorsi myografts. An experimental feasibility study.

Dynamic cardiomyoplasty, with use of a free latissimus dorsi myograft revascularized by the internal thoracic artery and vein, was performed in eight dogs subjected to electrical preconditioning for 8 to 12 weeks (group I) and in six unconditioned dogs (group II). The procedure was performed after the resection of the anterior wall of the left ventricle. Cardiac output and left ventricular stroke work were augmented by 23.7% +/- 9.4% and 44.1% +/- 15.9% after graft pacing with 50 Hz burst stimulation at a 1:1 synchronization ratio, while left atrial pressure ranged from 8 to 12 mm Hg. Analysis of the left ventricular function curve showed that graft pacing at rates of 1:1, 2:1, and 3:1 augmented global left ventricular function. Hemodynamic benefit by continuous pacing at a 3:1 ratio was seen for 1.97 +/- 1.90 hours (0.5 to 6.1 hours) in group I until complications unrelated to the graft terminated the study, while it lasted for only 0.19 +/- 0.09 hour in group II. During the stimulation, the ratio of the lactate output to the oxygen consumption of the graft in group I, a possible indicator of metabolic shift, was significantly less than in group II, (0.46 +/- 0.58 and 6.34 +/- 1.73; p < 0.01). We conclude that free grafts of transformed latissimus dorsi muscle can augment global left ventricular performance, with a physiologic preload by oxidative metabolism, and provide a viable option in full-thickness dynamic cardiomyoplasty.

Animals↗
PubMed1992

[The inhibitory effects of anti-asthmatic agents on ethanol-induced bronchoconstriction in Japanese asthmatic patients].

Asthmatic symptoms are worsened after drinking small amounts of alcoholic beverages in Japanese asthmatic patients. Our previous results showed that the ingestion of pure ethanol caused a fall in FEV1.0 in about half of the Japanese asthmatics we studied. We studied the inhibitory effects of pretreatment with three kinds of anti-asthmatic agents on ethanol-induced bronchoconstriction in six Japanese asthmatic patients. We tested oral cyproheptadine hydrochloride (8 mg), which is an anti histamine agent, inhaled disodium cromoglycate (2 mg), which has an inhibitory effect on the release of chemical mediators from mast cells, and inhaled atropine sulfate (3 mg), which is an anti-cholinergic agent. Pretreatment with cyproheptadine significantly inhibited the fall in FEV1.0 120 minutes after ethanol challenge (p less than 0.05). Inhaled DSCG had significant inhibitory effects on the fall in FEV1.0 15 and 30 minutes after ethanol challenge (p less than 0.05). Inhaled atropine had no inhibitory effect. These results suggest that histamine, released from mast cells, plays an important role in ethanol induced bronchoconstriction in Japanese asthmatic patients.

Adult↗
PubMed1992

[Prevalence and pathogenesis of iron deficiency in Japanese women (1981-1991)].

Iron deficiency anemia is the most prevalent among form of anemia in the world. In Japan, there is no overall report concerning prevalence and pathogenesis of iron deficiency. We estimated the prevalence of iron deficiency from the results of a survey of 3,015 Japanese women. The reference range for hemoglobin was derived from the average value of subjects with normal iron status (> or = 16% of transferrin saturation and > or = 12 ng/ml of serum ferritin). Using these reference standards, the prevalence of iron deficiency anemia, latent iron deficiency, storage iron deficiency, normal and others were 8.5%, 8.0%, 33.4%, 43.6% and 6.5%, respectively. The prevalence of iron deficiency anemia increased beginning in early lower teen girls, was highest in high teen-girls and, young women and decreased in elderly women. In elderly women, the cause of iron deficiency was often obvious associated with anemia of chronic disorders. The strategy for iron deficiency was discussed concerning iron fortification, mega-ingestion of vitamin C and low dose administration of iron tablets in the higher incidence group.

Adolescent↗
PubMed1992

[Chronic cold agglutinin disease terminating in primary macroglobulinemia after a 10 year history].

A 60-year-old man was admitted with general fatigue and jaundice of one year's duration in February, 1981. The hemoglobin (Hb) was 11.4 g/dl and reticulocytes were 1.7%. A diagnosis of chronic cold agglutinin disease (CCAD) was made from the presence of cold agglutinin (CA) 1:2,048, increased serum IgM 267 mg/dl and indirect bilirubin 1.4 mg/dl. His Hb was approximately 11 g/dl in summer and 9 g/dl in winter for the subsequent ten years without therapy. In July, 1990, he was readmitted because of exacerbation of anemia and hepatosplenomegaly. The Hb was 4.6 g/dl, indirect bilirubin 3. 1 mg/dl, CA titer 1:232,144 and reticulocytes were 20%. Serum IgM was 1,065 mg/dl, and immunoelectrophoresis showed IgM-kappa M-protein. Peripheral blood lymphoid cells expressed surface membrane immunoglobulin (SmIg) M and kappa. The bone marrow showed an increased number of lymphoid cells which also expressed SmIg M and kappa. These findings were compatible with those of the features of primary macroglobulinemia (PMG). The M-2 protocol resulted in decrease in serum IgM and CA, but he died of heart failure in February, 1991. The relationship between CCAD and PMG in relation to the pathogenesis was discussed.

Aged↗
PubMed1992

[Intralesional and transarterial administration of interferon for renal cell carcinoma].

Topical administration of interferon for locally recurrent renal cell carcinoma in 2 cases was reported. Case 1: a 56-year-old woman had undergone radical nephrectomy for left renal cell carcinoma. She had a locally recurrent tumor adjacent to spleen 26 months after the surgery. She received 3 million units of interferon alpha every day intralesionally for almost 3 years without any distant metastasis. Case 2: a 59-year-old man had undergone left radical nephrectomy for renal cell carcinoma. He had recurrent tumor contiguous to spleen 24 months after nephrectomy. With Seldinger method a catheter was indwelled selectively in splenic artery. Two million units of interferon gamma was administered through the catheter, twice a week for 4 weeks, and once a week in subsequent course. The tumor showed necrosis on CT film. He died of DIC 5 months after the initiation of intraarterial administration of interferon gamma. Topical use of interferon showed some favorable effects in both cases even after the failure of systemic administration. Further investigation is warranted to demonstrate the advantage of topical use of interferon over systemic administration.

Carcinoma, Renal Cell↗
PubMed1992

Long-term exposure of Wistar rats to high dietary sodium chloride level. I. Changes in aortic connective tissue components.

The effect of chronic salt loading on aortic components of connective tissue was evaluated in normotensive Wistar rats maintained on a high sodium chloride (NaCl; 8%) regime for a period of 30, 90, 180 and 360 days. The blood pressure remained unchanged until 90 days and was significantly elevated thereafter. The high NaCl diet for 180 days influenced neither the serum levels of both total cholesterol and triglyceride nor the aortic contents of collagen, elastin and glycosaminoglycans (GAG) derived from the proteoglycans. The only significant change associated with a 360-day massive NaCl ingestion was the increased aortic concentration of total GAG due to an increase in chondroitin sulfate, dermatan sulfate and heparan sulfate rather than hyaluronic acid. This study suggests that an increase in the contents of sulfated GAG occurred in the late stage of hypertensive aorta of NaCl loaded rats might be responsible, at least in part, for the pathogenesis of atherosclerotic cardiovascular disease.

Animals↗
PubMed1992

Long-term exposure of Wistar rats to high dietary sodium chloride level. II. Changes in hepatic drug-metabolizing and glutathione-related enzyme systems.

The effect of excess sodium chloride (NaCl) intake on hepatic drug-metabolizing and glutathione-related enzyme systems in rats was investigated for a period of 360 days. There was no change in any parameters studied until day 180 of the experiment. However, feeding of a 8% NaCl diet for 360 days produced a decrease in cytochrome P-450 content and an increase in glutathione peroxidase activity, and resulted in a lowered capacity of hepatic tissue to activate benzo[a]pyrene to mutagens detectable in the Ames bacterial mutagenesis assay. These observations suggest that although there may be little possibility of the involvement of high NaCl diet in the carcinogenic effects of benzo[a]pyrene, long-term excess NaCl intake could reduce the potential for detoxification of many xenobiotic compounds leading to various pathological process.

Animals↗
PubMed1992

[A case of allergic bronchopulmonary candidiasis treated with amphotericin B inhalation].

A 77-year-old man underwent emergency admission for nocturnal asthmatic attack. Although his asthmatic attack improved within a few days with treatment including systemic corticosteroid, bilateral recurrent infiltrative shadows developed in his chest roentgenogram in association with a further exacerbation of dyspnea. Various antibiotic agents were given; however, the pulmonary infiltration did not improve. He was transferred to our department with the diagnosis of intractable pneumonia. C. albicans was detected in the sputum, and both IgE antibody and precipitating antibody specific for C. albicans were positive. Immediate cutaneous reactivity to C. albicans was positive even with a million-fold dilution of antigen extract C. albicans was also detected in bronchoalveolar lavage fluid. A diagnosis of allergic bronchopulmonary candidiasis was made. Chest roentgenographic findings as well as clinical symptoms improved with inhalation of 50 mg of amphotericin B.

Administration, Inhalation↗
PubMed1992

Papillary renal cell carcinoma. Report of two cases.

Papillary renal cell carcinoma is an uncommon variant of renal cell carcinoma which has unique features including hypovascularity or avascularity, extensive stromal macrophage infiltration and better prognosis than that for nonpapillary renal cell carcinoma. Two cases of papillary renal cell carcinoma presenting hypovascular or avascular angiology are presented. Histologically, the two tumors had a purely papillary structure. Papillae were lined by a layer of epithelial cells which lacked prominent cellular atypia, and there were numerous macrophages in the stroma. In addition, in one patient, extensive calcification of the tumor capsule was present. Furthermore, our experience in the present study with imprint cytology indicates that it offers corroborative information for the intraoperative diagnosis made on the basis of frozen section examination.

Adult↗
PubMed1992

[Right aortic arch with mirror-image branching and coarctation of the aorta--a case report].

The right aortic arch with coarctation of the aorta was reported. A 56-year-old woman admitted to the hospital because of headache and hypertension. Cardiac catheterization revealed the right aortic arch with coarctation of the aorta and 80 mmHg pressure gradient across the coarctation. The bypass operation with a 14 mm Dacron graft between the ascending to descending aorta was performed. There was no peak systolic pressure gradient between the ascending and descending aorta after bypass operation. This patient is the fourth case report with both mirror-image type right aortic arch and coarctation of the aorta.

Aorta, Thoracic↗
PubMed1991

Purification and structural study of two albumin variants in an Irish population.

Two types of variant albumins were detected during routine electrophoresis on cellulose acetate on 34,000 sera from patients in a relatively stable Irish population. The fast type (IRE1) (relative mobility 1.05) had a heterozygote frequency of 1/3,780, and the slow type (IRE2) (relative mobility of 0.94) had a heterozygote frequency of 1/8,500. A method for purification of the two types of variants is described. Structural study of the fast variant established a single amino acid substitution 313 lysine----asparagine (313 Lys----Asn); this variant has been reported in several European populations and also in New Guinea indigenes. However, the slow variant has a new substitution, 479 glutamic acid----lysine (479 Glu----Lys). Because it appears to be uniquely Irish, the slow variant (formerly called IRE2) has been renamed albumin Dublin. Three other albumin variants most often reported in European populations (cumulative frequency only about 1/3,500) were not detected in this study. Because of the significance of albumin genetic variants for the study of protein evolution and as an aid in identification of drug-binding sites, clinical chemists are asked to be on the alert for cases of bisalbuminemia.

Adult↗
PubMed1991

Genetic variants of serum albumin in Americans and Japanese.

A collaborative search for albumin genetic variants (alloalbumins) was undertaken by cellulose acetate and agarose electrophoresis at pH 8.6 of the sera of patients at two major medical centers in the United States and of nearly 20,000 blood donors in Japan. Seventeen instances of alloalbuminemia were ascertained, and seven different alloalbumin types were characterized by structural study. Two previously unreported alloalbumin types were identified. In one type, which was present in a Caucasian family and designated Iowa City-1, aspartic acid at position 365 was replaced by valine (365 Asp----Val); this is the second reported mutation at this position. The other type present in a Japanese blood donor had the mutation 128 His----Arg. An unexpected finding was the presence in a single Japanese of a Naskapi-type alloalbumin (372 Lys----Glu), a variant that had previously been described only for certain Amerindian tribes in whom it occurs with a polymorphic frequency (greater than 1%) and in Eti Turks. An arginyl-albumin (-1 Arg, 1 Asp----Val) occurred in an American family. The other alloalbumin types identified were proalbumins Lille and Christchurch and albumin B that have a cumulative frequency of about 1:3500 in Caucasians probably because of the hypermutability of CpG dinucleotides at the mutated sites. All of the variants characterized in this study are point mutants, and the sites are spread throughout the albumin gene. However, about one-fourth of all known albumin mutations are clustered in the sequence segment from position 354 through 382.

Amino Acid Sequence↗
PubMed1991

Effector and regulatory cells in autoimmune oophoritis elicited by neonatal thymectomy.

(C57BL/6 x A/J)F1 (B6AF1) mice thymectomized between days 1 and 4 of age develop autoimmune oophoritis (D3TX oophoritis) 4 to 6 wk later. Oophoritis can be adoptively transferred to young recipients, and the disease in D3TX mice is prevented by reconstitution with normal adult spleen cells. The present study was further defined the nature of the effector and suppressor cells. Contrary to an earlier report, oophoritis is transferred to syngeneic and not allogeneic recipients. The spleen cells from D3TX mice when stimulated in vitro with Con A, also transfer oophoritis to adult recipients. The effector cells are CD4+: oophoritis transfer is abrogated by CD4 antibody and not by CD8 antibody and C. Spleen cells from D3TX male mice transfer disease less efficiently than female cells, thus endogenous ovarian Ag may be required for activation of effector T cells. T cells from normal adult spleen that suppress D3TX oophoritis also appear to be of CD4+ phenotype. These cells are likely to be derived from adult thymus because adult thymocytes also suppress D3TX disease. We were unable to substantiate the earlier claim that suppressor cells in normal mice are ovarian Ag specific. Thus male and female spleen cells suppress disease with comparable efficiency, and deprivation of endogenous ovarian Ag by neonatal ovariectomy of cell donors had no observable effect on disease suppression.

Animals↗
PubMed1991

A donor splice mutation and a single-base deletion produce two carboxyl-terminal variants of human serum albumin.

At least 35 allelic variants of human serum albumin have been sequenced at the protein level. All except two COOH-terminal variants, Catania and Venezia, are readily explainable as single-point substitutions. The two chain-termination variants are clustered in certain locations in Italy and are found in numerous unrelated individuals. In order to correlate the protein change in these variants with the corresponding DNA mutation, the two variant albumin genes have been cloned, sequenced, and compared to normal albumin genomic DNA. In the Catania variant, a single base deletion and subsequent frameshift leads to a shortened and altered COOH terminus. Albumin Venezia is caused by a mutation that alters the first consensus nucleotide of the 5' donor splice junction of intron 14 and the 3' end of exon 14, which is shortened from 68 to 43 base pairs. This change leads to an exon skipping event resulting in direct splicing of exon 13 to exon 15. The predicted Venezia albumin product has a truncated amino acid sequence (580 residues instead of 585), and the COOH-terminal sequence is altered after Glu-571. The variant COOH terminus ends with the dibasic sequence Arg-Lys that is apparently removed through stepwise cleavage by serum carboxypeptidase B to yield several forms of circulating albumin.

Amino Acid Sequence↗
PubMed1991

Cadmium toxicity in the thyroid gland of pregnant rats.

The toxic effects of cadmium on the thyroid gland of pregnant rats were studied with an electron microscope and an X-ray microanalyzer. Serum levels of thyroid hormones (T3 and T4) were also analyzed. Deterioration of the rough-surfaced endoplasmic reticulum occurred in the thyroid follicular epithelium on the fifth day of cadmium treatment. Large intracellular vacuoles, which arose from dilated cisternae of the rough-surfaced endoplasmic reticulum, were fused together, and marked swelling of the mitochondria was also noted. Thyroglobulin-secreting granules at the apical cytoplasm were decreased in number. By energy dispersive X-ray microanalysis, cadmium peaks were preferentially obtained from swollen mitochondria in the follicular epithelial cells. Serum levels of T3 and T4 were significantly decreased in cadmium-treated rats dams when compared to those of controls. In the present experiment, cycloheximide also caused degenerative changes in the rough-surfaced endoplasmic reticulum and the disappearance of thyroglobulin-secreting granules. Cycloheximide is a known inhibitor of protein synthesis on cytosolic ribosomes. These results indicated that accumulated cadmium in the mitochondria of thyroid follicular epithelial cells might disturb the oxidative phosphorylation of this organelle and the loss of energy supply possibly caused the inhibition of the synthesis and release of thyroid hormones.

Animals↗
PubMed1991

Sensitivity and responsiveness of glucose output to insulin in isolated perfused liver from dexamethasone-treated rats.

To elucidate insulin action on hepatic glucose output (glycogenolysis) in the state exposed to an excess glucocorticoid, the fed rat liver was isolated and cyclically perfused with a medium containing 5 mM glucose and various concentrations of insulin. The rat was subcutaneously injected with 1 mg/kg of dexamethasone (Dex) for 7 days. Dex-treated rats showed marked increases of serum insulin and plasma glucose level compared with those in control rats. Hepatic glycogen contents in Dex group were markedly increased compared with those in control (115 +/- 5 and 28 +/- 4 mg/g, respectively). Insulin extraction rate in the perfused liver was not different between control and Dex group. Perfusate glucose level after 60 min perfusion was much higher in the Dex-treated rat liver than that of the control at 0 microU/ml insulin (34.5 +/- 2.5 vs 23.0 +/- 2.0 mM, P less than 0.01), and reduced to the nadir level (19.0 +/- 3.0 and 13.0 +/- 1.5 mM, respectively) at 100 microU/ml insulin in both groups, i.e., the decreasing rate in perfusate glucose level was not different between Dex and control group (43% and 44%, respectively). These results suggest that Dex-treatment augments hepatic glucose output, but does not affect the sensitivity and responsiveness of that to insulin.

Animals↗
PubMed1991

Sleep apnea in patients with acute myocardial infarction.

OBJECTIVE: To document sleep apnea in the acute phase of myocardial infarction. If apnea occurs in patients with myocardial infarction, hypoxemia induced by apnea might exaggerate insufficiency of oxygen supplied to the damaged myocardium. DESIGN: Prospective controlled study. SETTING: Critical care unit of a teaching hospital. PATIENTS: Forty-nine patients, average age 64 yrs (range 49 to 91). MEASUREMENTS AND MAIN RESULTS: Patient measurements were recorded on a polygraph using an apnea-monitor, pulse oximeter, pulmonary artery pressure monitor, and an ECG. All of the patients observed showed frequent apneic episodes. The apnea was especially frequent when the cardiac index was low. Capillary oxygen saturation of less than 90% (suggesting systemic hypoxia) was observed in 21 patients concomitantly with apnea. Occasionally, arrhythmias followed these episodes (premature supraventricular contractions [n = 10], premature ventricular contraction [n = 4], and ventricular tachycardia [n = 2]). CONCLUSIONS: This study suggests that sleep apnea is common in the setting of acute myocardial infarction. It may be a factor predisposing to, or even causing, sudden death in patients with acute phase of myocardial infarction.

Adult↗