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Biomedical subjects

Y Kanegae

Publications and source records attributed to Y Kanegae.

64 records · Page 4Linked to original sources
PubMed1994

A simple and efficient method for purification of infectious recombinant adenovirus.

Recently, the adenovirus expression vector attracts much attention for the application to gene therapy and the method to purify and concentrate adenovirus without loss of infectivity has become very important, especially for animal experiments and gene therapy of humans. In this report, we show a simple and efficient method for purifying infectious adenovirus. The method consists of sequential centrifugation in CsCl step gradients without loss of infectivity and can be completed in one day. The method maintained the viral infectivity after 10-fold concentration and seemed to remove more than 99.9% of carried-over proteins. We showed also that the buffers for dialyzing the purified virions influenced the stability of infectivity. The buffers of 10 mM HEPES-1 mM EDTA-10% glycerol and PBS(-)-10% glycerol resulted in higher stability than did 10 mM HEPES-1 mM MgCl2-10% glycerol. The method is may be useful in many applications of recombinant adenovirus.

Adenoviridae↗
PubMed1993

Trans-ventricular septal defect approach for resection of accessory mitral valve tissue.

Accessory mitral valve tissue is a rare cause of left ventricular outflow tract obstruction, which can be difficult to recognize. Surgical resection by the conventional transaortic approach with or without left atriotomy is extremely difficult in infants with a small aorta. When a ventricular septal defect is present, it may be the best way to approach the accessory mitral valve tissue, because the ventricular septal defect is located just in front of it. Five infants underwent resection of accessory mitral valve tissue together with repair of other intracardiac malformations. In 3 infants, resection of accessory mitral valve tissue was easily performed through the ventricular septal defect, which required enlargement in 2 patients.

Female↗
PubMed1992

Analysis of determinants of ventricular fibrillation induced by reperfusion: dissociation between electrical instability and myocardial damage.

To assess the underlying mechanisms of ventricular fibrillation induced by myocardial reperfusion after cardioplegic arrest, 62 patients undergoing an open heart operation were divided into two groups based on the absence (group 1, n = 37) or the development (group 2, n = 25) of reperfusion-induced ventricular fibrillation. There was no close relationship between the incidence of reperfusion-induced ventricular fibrillation and aortic clamp time. On reperfusion, the time to onset of cardiac activity was similar in groups 1 (2.4 +/- 1.8 minutes) and 2 (1.9 +/- 1.1 minutes). At that time, there was no significant difference in values of arterial oxygen and bicarbonate contents, pH, or base excess between the two groups, but myocardial temperature was significantly higher in group 2 (25.6 degrees +/- 3.4 degrees versus 27.6 degrees +/- 2.4 degrees C; p less than 0.05). In addition, serum levels of sodium (123.9 +/- 4.2 versus 126.1 +/- 3.7 mmol/L; p less than 0.05) and calcium (0.80 +/- 0.07 versus 0.84 +/- 0.05 mmol/L; p less than 0.05) were significantly higher and serum potassium levels (3.98 +/- 0.58 versus 3.55 +/- 0.61 mmol/L; p less than 0.02) and the serum potassium to calcium ratio (4.94 +/- 0.90 versus 4.29 +/- 0.72; p less than 0.01) significantly lower in group 2. Postoperative serum levels of the myocardial-specific isoenzyme of creatine kinase and myoglobin were similar in both groups. By multivariate analysis, shorter ischemic time, higher myocardial temperature, higher serum sodium concentration, and lower serum potassium to calcium ratio were found to influence induction of reperfusion-induced ventricular fibrillation.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Temperature↗
PubMed1992

Origin and evolutionary characteristics of antigenic reassortant influenza A (H1N2) viruses isolated from man in China.

During the 1988/1989 influenza season, five antigenic reassortant influenza A (H1N2) viruses not previously isolated from man were isolated in Hebei province, People's Republic of China. All isolates contained haemagglutinins (HAs) and neuraminidases (NAs) which were antigenically similar to those of the recent Russian (H1N1) and Hong Kong influenza A (H3N2) viruses, respectively. The results of antigenic and nucleotide sequence analyses revealed that the genes encoding the polymerase, nucleoprotein, NA, matrix and non-structural proteins of the reassortant A/Hebei/24/89 (H1N2) virus were derived from the H3N2 parent virus, whereas its HA gene was from the H1N1 parent virus. The nucleotide sequences of the HA (encoding the HA1 subunit) and NA genes of the reassortant viruses were also determined. Phylogenetic trees constructed from these data by the neighbour-joining method revealed that the HA gene of the reassortant virus was closely related to those of recent human H1N1 viruses, whereas the NA gene was related to a recent human Hong Kong (H3N2) virus lineage.

Antigens, Viral↗
PubMed1991

Molecular evolution of hemagglutinin genes of H1N1 swine and human influenza A viruses.

The hemagglutinin (HA) genes of influenza type A (H1N1) viruses isolated from swine were cloned into plasmid vectors and their nucleotide sequences were determined. A phylogenetic tree for the HA genes of swine and human influenza viruses was constructed by the neighbor-joining method. It showed that the divergence between swine and human HA genes might have occurred around 1905. The estimated rates of synonymous (silent) substitutions for swine and human influenza viruses were almost the same. For both viruses, the rate of synonymous substitution was much higher than that of nonsynonymous (amino acid altering) substitution. It is the case even for only the antigenic sites of the HA. This feature is consistent with the neutral theory of molecular evolution. The rate of nonsynonymous substitution for human influenza viruses was three times the rate for swine influenza viruses. In particular, nonsynonymous substitutions at antigenic sites occurred less frequently in swine than in humans. The difference in the rate of nonsynonymous substitution between swine and human influenza viruses can be explained by the different degrees of functional constraint operating on the amino acid sequence of the HA in both hosts.

Amino Acid Sequence↗
PubMed1991

Evolutionary pathways of N2 neuraminidases of swine and human influenza A viruses: origin of the neuraminidase genes of two reassortants (H1N2) isolated from pigs.

The complete nucleotide sequences of the neuraminidase (NA) genes of two reassortant (H1N2) and two H3N2 influenza A viruses isolated from pigs were determined and phylogenetic relationships between these and previously reported N2 NA genes were investigated. On the basis of pairwise nucleotide sequence identity, the NA genes of two reassortants, A/sw/Kanagawa/2/78 and A/sw/Ehime/1/80, were most closely related to those of human influenza A virus strains isolated in 1972 and the earliest available swine H3N2 influenza A viruses, respectively. Phylogenetic trees showed that the NA genes can be segregated into three groups, including lineages for (i) swine strains, (ii) the earliest human strain and (iii) recent human strains. The evolutionary tree for the 11 nucleotide and amino acid sequences suggested that the NAs of A/sw/HK/4/76 and A/sw/Kanagawa/2/78 belong to the lineage for recent human viruses. In contrast, the NA genes of the A/sw/HK/3/76 and H1N2 reassortant A/sw/Ehime/1/80 viruses were found to be of a swine lineage. The swine virus NA genes were further characterized by the cocirculation of two distinct lineages. Although the rates of synonymous (silent) substitutions for the swine and human viruses were nearly identical (0.00946 to 0.00884 per site per year), the rate of non-synonymous (amino acid changing) substitutions for swine virus NA genes was about 60% of that for the human virus.

Amino Acid Sequence↗
PubMed1990

Evolutionary pattern of the hemagglutinin gene of influenza B viruses isolated in Japan: cocirculating lineages in the same epidemic season.

The unexpectedly low efficacy of influenza vaccine during school outbreaks of influenza B virus in the spring of 1987 in Japan was probably attributable to a poor antibody response of vaccinees to the epidemic viruses. An antigenic analysis of the causative B viruses isolated in 1987 and 1988 showed much variation in hemagglutination inhibition patterns. The nucleotide sequences that code for the HA1 domain of B/Fukuoka/c-27/81, B/Ibaraki/2/85, B/Nagasaki/1/87, and B/Yamagata/16/88 viruses were determined and compared with those of the previously reported hemagglutinin genes. The nucleotide sequences of the hemagglutinin gene of a new variant, B/Yamagata/16/88, had only 93.4% homology with those of two other viruses from the same epidemic. An analysis of nucleotide and amino acid substitutions of the hemagglutinin genes of influenza B viruses revealed that new and some old variants could cocirculate in the same epidemic. A phylogenetic tree constructed by the neighbor-joining method allowed estimation of an evolutionary rate of 2.3 x 10(-3) synonymous (silent) substitutions per nucleotide site per year in the hemagglutinin gene.

Adolescent↗
PubMedDate not supplied

Preservation of the pulmonary valve during intracardiac repair of tetralogy of Fallot.

From January 1981 to December 1990, intracardiac repair of tetralogy of Fallot in 148 pediatric patients, with one surgical death, was directed toward preservation of the native pulmonary valve. Using the accepted preoperative angiographic criterion for the pulmonary valve annulus area (PVA) of 1.8 cm2/m2, 85 patients were candidates for transannular right ventricular outflow patch (TAP). However, in 54 patients with a mean PVA of 1.5 cm2/m2 (range 1.06-1.76), the valve was preserved without using TAP because the morphological changes (cusp thickening and annular distensibility) seemed acceptable for preservation in view of its probable hemodynamic efficiency and growth potential. A morphological classification of pulmonary valve changes has evolved. Retrospectively, 24 (77%) of the 31 patients with TAP had moderate to severe cusp thickening and ring rigidity; this incidence was significantly higher (p < 0.001) than that in preserved patients (18 of 54 or 33%). The incidence of morphological changes increased with operative age; that is, 2 of 13 (15%) patients younger than 1 year versus 23 of 40 (58%) patients older than 4 years (p < 0.01). All 54 patients with preserved pulmonary valves were catheterized one month postoperatively. The intraoperative right to left ventricular systolic pressure ratio (RVP/LVP) decreased significantly (p < 0.005) in one month, from a mean of 0.79 (range 0.44-1.36) to 0.57 (range 0.36-0.97). The PVA increased from a mean of 1.5 to 1.9 cm2/m2 (range 1.20-2.65), and the rate of its increase was significantly larger (p < 0.005) as operative age decreased. Pulmonary valve regurgitation of greater than mild degree occurred in 8 of 54 (15%) patients with the valve preserved.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMedDate not supplied

Tranexamic acid reduces blood loss after cardiopulmonary bypass.

To evaluate the effect of tranexamic acid (TA) on blood loss after cardiopulmonary bypass (CPB), 157 patients who underwent elective valve replacement operations were studied, with one group of 90 patients receiving tranexamic acid (Group TA) and 67 patients serving as the control group (Group N). In group TA, 50 mg/kg of tranexamic acid was administered just before and after CPB, and every 90 minutes during CPB. The activated coagulation time was maintained at more than 450 seconds during CPB in both groups. There was no significant difference in the CPB time between the groups (163 +/- 32 min in group N and 152 +/- 38 min in group TA:NS). The time required for hemostasis was shortened in group TA, which resulted in a shorter operation time (6.7 +/- 1.5 hrs vs 6.0 +/- 1.5 hrs in group N and group TA, respectively: p = 0.006). The amount of chest tube drainage within 12 hours after surgery was significantly reduced (225 +/- 129 ml vs. 180 +/- 118 ml in group N and group TA, respectively: p = 0.026). The chest tube was able to be removed earlier in group TA, and the total blood loss was significantly smaller in group TA (402 +/- 292 ml) than in group N (631 +/- 609 ml; p = 0.004). The authors thus conclude that antifibrinolytic therapy during CPB with tranexamic acid reduces postoperative blood loss, and shortens the operation time due to an improvement in hemostasis.

Adult↗