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Biomedical subjects

A Endo

Publications and source records attributed to A Endo.

At least 109 records · Page 6Linked to original sources

Total synthesis of glycononaosyl ceramide with a sialyl dimeric Le(x)-sequence.

The first total synthesis of glycononaosyl ceramide with a sialyl dimeric Le(x) sequence 1 is described. Regio- and stereo-selective glycosylations of sialyl donors 6,7,8 with the suitably protected Le(x) trisaccharide acceptors 9,10 beta were performed to give the expected tetrasaccharides 15 and 21, which were converted into the corresponding donors 20 and 22. Boron trifluoride etherate-promoted glycosylation of 20 with pentasaccharide acceptor 11 afforded regioselectively the expected nonasaccharide 23. After replacing benzyl groups of 23 by acetyl groups, the anomeric acetate was transformed into the alpha-trichloroacetimidate 27. The crucial coupling between 27 and (2S, 3R, 4E-3-O-benzoyl-2-N-tetracosanoylsphingenine 3 was executed to afford completely protected beta-glycoside 28. Finally, selective cleavage of the methyl ester and N,O-deprotection of 28 gave the target ganglioside 1.

Carbohydrate Sequence↗

Evolutionary characterization of recent human H3N2 influenza A isolates from Japan and China: novel changes in the receptor binding domain.

Recent human H3N2 influenza viruses isolated in Japan and China were characterised from an evolutionary point of view. They appeared to have divided into three minor branch clusters, including 1992-1993, 1993-1994 and 1994-1995 isolates. It was of particular interest to reveal that in addition to amino acid substitutions in the antigenic sites of the HA molecule, amino acid changes occurred at position 226 of the receptor binding site from lysine or glutamine to isoleucine in all strains belonging to the 1994-1995 branch cluster. This is the first evidence of human H3N2 influenza isolates, or any other influenza HA serotypes, to contain a conserved amino acid residue other than lysine or glutamine at this key position.

Amino Acid Sequence↗

Antibody responses and protection in mice immunized orally against influenza virus.

Antibody responses and protection were studied in BALB/c mice immunized orally with formalin-inactivated influenza viruses (A/PR/8/34) combined with cholera toxin B subunit as adjuvant. Influenza virus-specific IgA as well as IgG antibody responses were induced in the mice, depending on the oral dosage frequency. The oral immunization by multiple doses resulted in reduction of viral replication in the nose and prevention of development of infection in the lung after intranasal (i.n.) challenge. The protective effect in the nose was thought to be related to the nasal IgA antibody response. The oral immunization was, however, less efficient for induction of the IgA antibody response and protection in the nose, compared with an i.n. immunization. The oral immunization following subcutaneous priming led to the complete protection in the nose, accompanied-by a prompt local IgA antibody response.

Adjuvants, Immunologic↗

K-ras gene mutation in sputum samples containing atypical cells and adenocarcinoma cells in the lung.

We analyzed the presence or absence of K-ras mutations in sputum samples with atypical cells by colony hybridization. The frequency of K-ras mutations in 104 patients with adenocarcinoma of the lung was also examined using dot blotting. No mutations in K-ras codon 12 were detected in the 12 sputum samples examined, which included three specimens from patients who later developed lung adenocarcinoma. Because of the paucity of sputum samples, it was difficult to conclude whether K-ras gene mutations are useful for molecular screening for lung cancer at the present time. Secondly, we detected 12 cases [12%; 10 males (19%) and two females (4%)] with a K-ras mutation among 104 patients with lung adenocarcinoma. Although the smoking rate of patients (89%) was higher than the general Japanese male population (approximately 60%), indicating that smoking may be related to the occurrence of adenocarcinoma of the lung, it was unclear whether smoking was related to K-ras mutation from our results. Other factors may contribute to K-ras mutation.

Adenocarcinoma↗

Bacterial changes in neonatal intensive care unit.

Organisms routinely cultured from throat swabs and infectious agents of sepsis and/or meningitis were reviewed. During the last 12 years, Klebsiella pneumoniae and Escherichia coli have been replaced by Staphylococcus aureus and Pseudomonas aeruginosa as the predominant isolates from throat swabs after admission. These change in the etiologic pattern of infectious agents of sepsis and/or meningitis, i.e., K. pneumoniae, E. coli, S. aureus, P. aeruginosa and staphylococcus epidermidis, were in agreement with the organisms isolated from the throat swabs after admission. The S. aureus isolated from throat swabs after admission showed a decrease in the bacterial activity of cloxacillin, cephazolin and cefotaxime since 1978.

Bacteria↗

Cytogenetic effects of advanced maternal age and delayed fertilization on first-cleavage mouse embryos.

It has been shown that both advanced maternal age and delayed fertilization may induce chromosomal anomalies. We therefore examined the combined effects of these two factors on chromosomal anomalies in first-cleavage mouse embryos. We set up normal and (6-h) delayed subgroups in two different age groups (young, 3-4 mo; aged, 9-11 mo) and compared the incidence of chromosomal anomalies. In first-cleavage embryos, egg-derived chromosomes can be distinguished from sperm-derived chromosomes. The incidence of maternally derived aneuploidy was highest in the aged-delayed fertilization subgroup. We therefore conclude that advanced maternal age affects the production of aneuploidy more severely when combined with the effect of delayed fertilization.

Aneuploidy↗

Nitric oxide and endothelin 1 during postnatal life.

Nitric oxide (NO) is a potent vasodilator produced by endothelial cells. Endothelin 1 (ET-1), another agent made by endothelial cells, is the most potent vasoconstrictor known to date. Endogenous NO and ET-1 may play a part in the normal physiological pulmonary vascular changes during the postnatal period. However, the changes of NO and ET-1 in healthy neonates have not been defined. We determined serum NO metabolites, i.e., nitrites and nitrates, and plasma ET-1 in 19 healthy neonates at birth (cord blood) and at ages 5 and 30 days. The sums of serum nitrite and nitrate (NOx) levels were 27.5 +/- 12.8, 53.8 +/- 14.2, and 38.3 +/- 13.2 mumol/l at birth, age 5 days, and age 30 days, respectively. The plasma ET-1 concentrations were 3.9 +/- 1.6, 1.1 +/- 0.2, and 1.1 +/- 0.2 x 10(6) mumol/l at birth, age 5 days, and age 30 days, respectively. These changes in healthy neonates suggest the presence of active physiological roles for NO and ET-1 in circulatory adaptation to extra-uterine life.

Aging↗

Exercise-induced U-wave changes in patients with coronary artery disease--correlation with tomographic thallium-201 myocardial imaging.

We studied the relation between exercise-induced U-wave changes and the site of a reversible defect in tomographic 201Tl myocardial imaging. Coronary artery disease and control groups consisted of 116 and 42 patients, respectively. In the anteroapical-ischemia group (n = 37), the sensitivity of U-wave inversion in the anterior precordial leads for ischemia was 62% (23/37) and that of prominent U-waves without an increase in the height of the T-wave in the inferior limb leads was 57% (21/37). In this group, 18 patients (49%) met both criteria (18 [78%] of 23 patients with the former; 18 [86%] of 21 patients with the latter). In the posterior-ischemia group (n = 59), the sensitivity of prominent U-waves with a decrease in the height of the T-wave in the anterior precordial leads for ischemia was 63% (37/59) and that of U-wave inversion in the inferior limb leads was 20% (12/59). In this group, 12 patients (20%) met both criteria (12 [32%] of 37 patients with the former; all 12 patients with the latter). The specificity of U-wave criteria was 100%. In the anteroapical and posterior ischemia group (n = 20), the sensitivity of U-wave criteria for anteroapical and posterior ischemia was 85% (17/20) and 40% (8/20), respectively. In conclusion, U-wave criteria are not only specific but also sensitive for myocardial ischemia determined by 201Tl imaging.

Aged↗

Prolongation of duration of ovulation in ageing mice.

In female mice, fertility and fecundity decrease progressively with ageing for unknown reasons. The time of day at which ovulation occurred and the time required for all the follicles to ovulate in young (10-14 weeks), middle-aged (9-11 months) and old (13-15 months) female mice were compared under controlled lighting conditions (12 h dark to 12 h light) to determine the relationship between maternal age and reproductive loss. The number of oocytes present in the follicles and the ampullae were counted at intervals of 1 h after mating. In the groups of young and middle-aged mice, the percentage of oocytes ovulated into the ampullae increased gradually and reached almost 100% at 7 h after the midpoint of the dark period. Whereas, in the group of old mice, it took twice as long (15 h) to reach 100%. However, the mean number of total oocytes remained relatively unchanged (young, 14.8: middle-aged, 16.2; old, 13.8). The prolongation in the time required for all the follicles to ovulate in old female mice may therefore be associated with a low fertilization rate and consequently the age-related decrease in number of offspring produced.

Aging↗

Isolation of plactins A, B, C and D, novel cyclic pentapeptides that stimulate cellular fibrinolytic activity.

Four novel cyclic pentapeptides, designated plactins A, B, C and D, were isolated by solvent extraction and reverse-phase HPLC from mycelium of a fungal strain F165 that belongs to the order of Agonomycetales. By a combination of chemical and spectroscopic analyses and chemical synthesis, the structures of plactins A, B, C and D were determined to be cyclo(-D-Val-L-Leu-D-alloIle-L-Try-D-Arg-), cyclo(-D-Val-L-Leu-D-Leu-L-Tyr-D-Arg-), cyclo(-D-Val-L-Leu-D-alloIle-L-Phe-D-Arg-) and cyclo(-D-Val-L-Leu-D-Leu-L-Phe-D-Arg-), respectively. Plactins stimulated U937 cell-mediated degradation of 125I-fibrin plates by 50% at a concentration of 7.5 approximately 32 microM.

Amino Acid Sequence↗

Staplabin, a novel fungal triprenyl phenol which stimulates the binding of plasminogen to fibrin and U937 cells.

A novel triprenyl phenol, designated staplabin, has been isolated from a culture of Stachybotrys microspora IFO 30018 by solvent extraction and successive chromatographic fractionation using silica gel, Sephadex LH-20 and silica ODS columns. By a combination of spectroscopic analyses, the structure of staplabin is proposed to be 5-(2-(5,7-dihydroxy-8-methyl-8-(4,8-dimethyl-3,7-nonadienyl)-3-oxo -7, 8-dihydro-6H-pyrano[2,3-e][1,3]dihydroisoindolyl)pentanoic acid. Staplabin stimulated the binding of plasminogen, the zymogen of the fibrinolytic serine protease plasmin, to both fibrin and U937 cells. Binding was elevated 2-fold at a concentration of 0.3 approximately 0.5 mM.

Benzopyrans↗

Natural killer cell activity and cytokine production as prognostic factors in adult acute leukemia.

We studied the natural killer (NK) cell activity and in vitro production of the cytokines which can enhance NK activity (interleukin-1 beta (IL-1 beta), interferon gamma (IFN gamma), and interleukin-2 (IL-2)) after stimulation in 44 patients with acute leukemia (AL) and 14 normal controls. We also studied the influence of these parameters on relapse and the relapse-free survival (RFS) (after the date of assay) of the AL patients. The NK activity and the production of cytokines in the peripheral blood mononuclear cells (PBMNC) from 16 patients at the untreated or relapsed stage as well as from 12 patients after consolidation were significantly lower than those from controls (both P<0.01), and those from the 16 patients at maintenance or off treatment were also significantly lower than those from the controls (P<0.01 or P<0.05). RFS after the date of assay of the patients in remission with NK activity above the median value was significantly longer than that of the patients below the median (P<0.05). The production of cytokines in the PBMNC from patients who showed continuous complete remission for at least 6 months was higher than that from the patients who relapsed early. These findings suggest that impaired NK cell function and cytokine production are associated with early relapse of AL regardless of remission status.

Acute Disease↗

[Improvement of thrombocytopenia by administration of M-CSF in a patient with relapsed Philadelphia chromosome-positive acute lymphoblastic leukemia].

A 55-year old male, diagnosed as Ph1 (+) ALL in July 1992, subsequently achieved complete remission. However, he was admitted again in November 1993 because of relapse. Although blasts in bone marrow decreased following chemotherapy and G-CSF administration, thromocytopenia remained, and he needed platelet transfusions every other day. After he began receiving M-CSF, the platelet count increased and platelet transfusions became unnecessary. M-CSF may be useful for thrombocytopenia after chemotherapy in Ph1 (+) ALL.

Antineoplastic Combined Chemotherapy Protocols↗

[Clinical incidence of primary cardiac tumors].

Recently, clinical diagnostic methods for heart disease, especially echocardiography, have remarkably progressed and the incidence of cardiac tumors increased. This study investigated the characteristics of tumors in 115 patients with primary cardiac tumor, diagnosed histologically in 1993-1994, in collaboration with 126 university hospitals in Japan. Histological diagnosis, location, initial clinical manifestations and prognosis of cardiac tumors are reported. Of the 115 patients, 98 (85%) had primary benign tumor. Myxoma was the most common histological group (91 cases). Primary malignant cardiac tumors occurred in 17 patients (15%) of which rhabdomyosarcoma was the most frequent (5 cases). Sixty percent of patients with myxoma were female, a similar ratio to the proportion of female patients with other primary cardiac tumors. Most patients with myxoma had the tumor in the left side of the heart [76 cases (84%) in left side, 12 (13%) in right side, 3 (3%) in both sides]. In contrast, the primary malignant cardiac tumors occurred more in the right side of the heart rather than in the left side (eight in right side, six in left side). Embolization was the characteristic initial clinical manifestation for myxoma. There were no patients with initial manifestation of embolization in the other histological groups. Reflecting the recent progress and spread of clinical diagnostic methods, 17% of all patients were discovered asymptomatically. All patients with myxoma who were asymptomatic underwent operation, and there were no surgical deaths. In contrast, only one patient with primary malignant cardiac tumor could survive longer than a year. In conclusion, the progress and the spread of cardiovascular imaging has contributed to the early diagnosis of primary cardiac tumors. These data demonstrate new clinical and pathological characteristics of primary cardiac tumors seen in recent cardiologic practice in Japan.

Adolescent↗

Modulation of the plasma cholesteryl ester transfer by stachybotramide.

Plasma cholesteryl ester transfer protein (CETP), which mediates the transfer and exchange of neutral lipids (cholesteryl esters (CE) and triglycerides (TG) and phospholipids between plasma lipoproteins, plays an essential role in reverse cholesterol transport system. We have found that a fungal metabolite, stachybotramide, modulates the activity of CETP. Stachybotramide stimulated the [14C]CE transfer from high density lipoprotein (HDL) to very low density lipoprotein (VLDL) and low density lipoprotein (LDL) by 1.3- to 1.5-fold at 0.2-0.5 mM. This stimulation was abolished in the presence of anti-CETP antibody. On the other hand, the transfer of [14C]CE from LDL and VLDL to HDL was slightly reduced by stachybotramide at 0.5 mM. Unlike the transfer of [14C]CE, the transfer of [3H]TG from HDL was not significantly affected by stachybotramide. These results suggest that stachybotramide preferentially stimulate the CETP-mediated transfer of CE from HDL to both VLDL and LDL.

Antibodies, Monoclonal↗