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Biomedical subjects

M Fukasawa

Publications and source records attributed to M Fukasawa.

At least 91 records · Page 5Linked to original sources
PubMed1993

Isolation and characterization of simian immunodeficiency virus from African white-crowned mangabey monkeys (Cercocebus torquatus lunulatus).

Forty-eight of 236 sera from seven species of African non-human primates in Kenya, including those of white-crowned mangabey monkeys (Cercocebus torquatus lunulatus) had antibodies to simian immunodeficiency viruses (SIVs). Isolates of simian lentivirus were obtained from seropositive white-crowned mangabey monkeys which are indigenous in West Africa. This virus, designated as SIVWCM, appeared morphologically similar to HIV by electron microscopy, showed Mg(2+)-dependent reverse transcriptase activity, and induced cytopathic effects in human CD4-positive cells. Western blotting analysis revealed that env products of SIVWCM cross-reacted with those of SIVAGM more strongly than with those of HIV-1 and SIVMAC, and clear hybridization bands were detected with an SIVAGM probe. For comparison of the virus sequence with those of other primate lentiviruses, part of the pol gene and the long terminal repeats (LTRs) were amplified and cloned. Sequencing showed that SIVWCM isolates were closely related to SIVAGM isolates. This study suggested that SIVAGM from the Cercopithecus genus and SIVWCM from the Cercocebus genus may be members of an SIV group that is genetically distinct from the SIV from a sooty mangabey monkey (SIVSMM) of the genus Cercocebus, to which the white-crowned mangabey monkey also belongs.

Animals↗
PubMed1993

Feline immunodeficiency virus gene expression: analysis of the RNA splicing pattern and the monocistronic rev mRNA.

The transcription pattern of the feline immunodeficiency virus (FIV) genome in a feline CD4+ cell line was examined. In addition to the genomic RNA (9.2 kb), at least five FIV-specific transcripts [5.2, 4.4 (doublet), 1.7 and 1.4 kb] were detected by using subgenomic restriction enzyme fragments of an FIV molecular clone or FIV-specific oligonucleotides as probes. Among these transcripts, the 9.2, 5.2 and 4.4 (doublet) kb mRNAs were not expressed in the cytoplasm of cells transfected with a rev- mutant. To determine the location of splice junctions in the FIV genome, we used PCR to amplify and clone cDNAs corresponding to the viral mRNAs from infected cells. The region between pol and env was found to contain at least two splice donor and three splice acceptor sites. Two splice acceptor sites were detected in the 3' region of env. By hybridization analysis and sequencing of cDNA clones, it was revealed that the medium sized mRNAs are derived from a single splice event, with different splice acceptor sites, and that the two smaller transcripts are doubly or triply spliced mRNAs. Our results demonstrate a complex pattern of alternative splicing of FIV mRNAs. Furthermore, we identified monocistronic rev mRNA species that employ a unique splice acceptor site.

Amino Acid Sequence↗
PubMed1993

Transient carbapenem resistance induced by salicylate in Pseudomonas aeruginosa associated with suppression of outer membrane protein D2 synthesis.

Pseudomonas aeruginosa PAO1 showed increased phenotypic resistance to imipenem, panipenem, and biapenem specifically in the presence of salicylate. The antipseudomonal activity of carbapenems was reduced in proportion to the concentration of salicylate. This resistance was transient and nonheritable. The synthesis of the outer membrane protein D2 (OprD or OprD2) in P. aeruginosa PAO1 was inhibited by 4 to 32 mM salicylate in the bacterial growth medium, whereas no changes in any other outer membrane proteins were observed. These results indicate that salicylate suppresses the synthesis of OprD and therefore reduces the antipseudomonal activity of carbapenems. Under these conditions, one carbapenem--meropenem--is still active against P. aeruginosa, which indicates that meropenem can pass through the outer membrane via both the D2 channel and another undefined route(s).

Anti-Arrhythmia Agents↗
PubMed1993

Modulation of cardiac myocyte beating rate and hypertrophy by cardiac fibroblasts isolated from neonatal rat ventricle.

We evaluated the in vitro modulation of cardiac myocyte beating rate and growth hypertrophy in the presence or absence of cardiac fibroblasts. Cardiac myocytes and fibroblasts were isolated from neonatal rat ventricles, and cultures of either myocytes alone or of myocytes in co-culture with fibroblasts were established and observed for 21 days. The beating rate in control myocytes increased rapidly, reached peak values on day 5 (266.2 +/- 58.2 beat/min), and then decreased by day 21. The beating rate of myocytes which were co-cultured with fibroblasts in group 2-1 (2-1 ratio of myocytes to fibroblasts, 6.0 x 10(5) total cells/well) was significantly lower than that in control myocytes, and showed a decreased peak value on day 7 (135.1 +/- 46.4). The beating rate in group 1-1 was significantly less than that of group 2-1, with a peak value on day 7 (85.9 +/- 24.9). Group 1-2 myocytes did not show a beating rate increase. Myocyte hypertrophy was measured after three days of culture. The surface area of myocytes which had been co-cultured with fibroblasts was significantly increased, as compared to that of control myocytes. In addition, myocyte surface area increased with increasing numbers of fibroblasts (mean myocyte surface areas in group 2-1, 1-1 and 1-2 were 143 +/- 21, 163 +/- 33, 206 +/- 38% of control, respectively). In conclusion, suppression of the myocyte beating rate and acceleration of myocyte hypertrophy are characteristic expressions of myocyte differentiation and growth during the neonatal period The present results suggest that fibroblasts play an important role in controlling myocyte development.

Animals↗
PubMed1993

PC-766B, a new macrolide antibiotic produced by Nocardia brasiliensis. I. Taxonomy, fermentation and biological activity.

An actinomycete strain SC-4710, a new soil isolate, was found to produce a new macrolide antibiotic, PC-766B. Chemotaxonomic analysis of the producing organism revealed that the cells of SC-4710 had type IV cell wall, type A whole cell sugar pattern, type PII phospholipids, menaquinone MK-8(H4), cellular fatty acids comprising straight-chain saturated, unsaturated and tuberculostearic acids, and mycolic acids. The strain was identified as Nocardia brasiliensis (Lindenberg) Pinoy. The antibiotic, PC-766B, was active against Gram-positive bacteria, and some fungi and yeasts, but inactive against Gram-negative bacteria. It also showed antitumor activity against murine tumor cells in vitro and in vivo, and a weak inhibitory activity against Na+, K(+)-ATPase in vitro.

Animals↗
PubMed1993

[Post operative embolism and left atrial enlargement in the old-aged ASD (atrial septal defect) patients].

As the operation risk of ASD is little today, the unexpected postoperative complication such as embolism is a miserable concern. We experienced two cases of embolism, which were cerebral infarction, in old-aged patients after ASD correction. It has been reported that low cardiac function, atrial fibrillation and foreign body in the left atrium should be risk factors of the embolism after ASD correction. However, blood stasis in the left atrium due to its enlargement may be an essential risk factor of the embolism. Accordingly we evaluated the left atrial volume in 87 ASD patients without complicated cardiac disorder. There was a significant correlation between the age (X) and left atrial volume index (Y). (Y = 16.5 + 1.1X, r = 0.668, p < 0.001). Left atrial volume index in our two cases of cerebral infarction indicated 171.7, 190.8 ml/m2 respectively. The former case had sinus rhythm and its defect was directly closed, and the latter had atrial fibrillation and its defect was closed with teflon patch. In addition pulmonary artery pressure and cardiothoracic ratio correlated with left atrial volume index significantly. Although some investigators reported that pulmonary hypertension and cardiomegaly were the risk factors of embolism, the left atrial enlargement by aging was thought to be the main risk factor. Thus, we concluded that anticoagulant therapy was necessary for the ASD patients with marked left atrial enlargement.

Aged↗
PubMed1993

[A case of intrapleural rupture of pulmonary arteriovenous fistula].

The hemothorax due to rupture of arteriovenous fistula is very rare and only 6 cases of this complication have been reported in Japanese literature. 44-year-old male complained of chest pain and dyspnea. A chest roentgenogram revealed right pleural effusion and an abnormal pulmonary shadow. By further examination including pulmonary angiography, the rupture of pulmonary arteriovenous fistula into right pleural cavity was diagnosed. Partial resection of the right lung containing arteriovenous fistula was successfully performed and postoperative course was uneventful.

Adult↗
PubMed1993

Apolipoprotein E enhances lipid exchange between lipoproteins mediated by cholesteryl ester transfer protein.

The direct effect of apolipoprotein (apo) E on cholesteryl ester transfer protein (CETP) activity was studied using lipoproteins from a subject with apoE deficiency (Atherosclerosis. 1991. 88: 15-20) as a model system. The transfer of cholesteryl ester (CE) from discoidal bilayer particles (DBP) to very low density lipoprotein (VLDL) was enhanced by incorporation of apoE into VLDL. This enhancement was induced only in the presence of CETP activity. Moreover, after incubation of CETP with VLDL, CETP activity and immunoreactivity were coeluted with apoE-incorporated VLDL (E-VLDL) on a gel filtration column (Sephadex G-150), but there was little CETP activity and immunoreactivity with apoE-free VLDL (C-VLDL), suggesting that E-VLDL had higher affinity for CETP compared to C-VLDL. The supplementation of the apoE-deficient serum with apoE enhanced the CETP-mediated changes of amount of CE and triglyceride (TG) in the high density lipoprotein (HDL) fraction, which were completely inhibited by the addition of the monoclonal antibody against CETP that blocks CETP activity. Our results suggest that 1) apoE enhances the cholesteryl ester and triglyceride transfer between VLDL and HDL via cholesteryl ester transfer protein, and 2) this effect of apoE may be mediated by enhancing the affinity of CETP for VLDL.

Antibodies, Monoclonal↗
PubMed1993

[Suppurative mediastinitis after open heart surgery: in comparison between infants-children and adults].

Among 361 consecutive patients who underwent open surgery from Jan. 1987 to Sept. 1991, risk factors and clinical courses were analyzed retrospectively in comparison between infants-children and adults. Seven mediastinitis (4.0%) occurred in 173 adult patients (20 to 75 y/o, mean: 54.4 y/o) and were not associated with age, sex, type of disease, and duration of operation or cardiopulmonary bypass. Postoperative mediastinitis significantly increased in the patients with low output syndrome (LOS) determined as use of IABP and/or assistant circulations (p < 0.001) and reexploration for bleeding or tamponase was associated with an increased risk for mediastinitis (p < 0.01). Five mediastinitis (2.7%) occurred in 188 infants and children (0 to 17 y/o, mean: 4.2 y/o). All patients involved with mediastinitis were less than 12 month old (2.6 +/- 3.3 month). None of the other factors was associated with an increased risk for this complication. Bacterial cultures of exudate were positive in 11 of 12 patients, and identified as MRSA in 10 and Staphylococcus epidermidis in one. In the seven of adult patients, two developed sepsis and four died with other organic failures or mediastinal bleeding. All five of infants healed after postoperative 33 to 145 days. The immature state of immune response might associate with postoperative mediastinitis in infants, whether LOS may be important in the immune suppression by surgical stress in adults, and the prognosis of mediastinitis might be effected by prolonged depression of postoperative cardiac function in adult patients.

Adolescent↗
PubMed1993

[Palliative management of left atrioventricular valve atresia with normal aortic valve].

We present three cases of the left atrioventricular valve atresia (LAVVA) with normal aortic valve. All cases showed [S,D,D] and had concordant AV connection. First case had two functional ventricles with multiple VSD and ventriculo-arterial connection was normal. Interatrial communication was maintained through ASD and the infant underwent pulmonary arterial banding (PAB). Four years later, the patient underwent Blalock-Hanlon (B-H) procedure for an inadequate ASD. Second case showed the univentricular heart of right ventricle with double outlet. In this case, PFO was restrictive and the infant underwent B-H procedure. Ten days after initial palliation, patient underwent PAB. Third case showed the univentricular heart of left ventricle and transposed great arteries. This patient had also the coarctation of the aorta. B-H procedure, PAB and subclavian flap aortoplasty were performed simultaneously by bilateral thoracotomy. All patients have done well, with normal growth and development at the time of their last outpatient evaluation at 10 year, 9 months and 9 months after surgery respectively.

Aortic Valve↗
PubMed1993

[A depression of respiratory function following the cardiopulmonary bypass in infants and children].

Fourty-one patients (2-44 month old) underwent the closure of ventricular septal defect using moderate-hypothermic cardiopulmonary bypass (CPB). The respiratory index (RI) were monitored after CPB, as functional parameters of oxygenation capacity. At 15 min after CPB, there was the increased level in RI (2.22 +/- 0.45; normal value: 0.1-0.37). Thereafter, RI gradually decreased by 90 min after CPB (1.22 +/- 0.19), and again increased reaching peak levels by 12 hrs after ICU-entry (2.56 +/- 0.64). The patients who exceed 1.00 at 15 min after CPB (RI-15) remained higher levels in RI compared to less than 1.00 and had the prolonged controlled ventilation. The RI-15 correlated with pulmonary-systemic flow ratio (Qp/Qs) and pulmonary-left ventricular pressure ratio (PA/LV). There was no significant correlation between RI-15 and CPB factors including CPB time, dilution rate, rectal temperature, flow and perfusion pressure. These results suggest that pulmonary dysfunction following the CPB may not be simply occurred by CPB but also involved by preoperative conditions. An increased pulmonary blood flow might be one of important and predictive factor for the depression of oxygenation following the cardiac surgery in infants and children.

Cardiopulmonary Bypass↗
PubMed1993

[A blind point of vent catheter: air aspiration].

We experienced a case of saphenous vein air embolism after coronary artery bypass graft, in which case we used vent catheter kept in the left atrium. Though it was considered that air bubbles were never aspirated through vent catheter, we speculated that the origin of air bubbles must be the vent catheter. And we made an experiment on the motion of air in the vent catheter using a model of left heart composed with soft reserver (atrium) and pulsatile pump (ventricle). When the pulsatile pump was arrest, the air bubbles were never aspirated from the vent catheter to the soft reserver even if we vented with strong negative pressure. But, when the pulsatile pump was in motion and the left atrium was vented with some negative pressure, some leaks of air bubbles were recognized. So we must pay much more attention to the degree of venting when the heart is in motion. Sometimes we use overpressure safety valve composed with vent catheter, but measured left atrial pressure showed that decreased left atrial pressure was only 2 mmHg. So its use should be restricted in the patients with good ventricular function.

Catheterization, Central Venous↗
PubMed1992

The hemostatic effect of deacetylated chitin membrane on peritoneal injury in rabbit model.

In this study, we determined the effect of 80% deacetylated chitin (DAC-80) membrane on postsurgical bleeding after visceral and parietal peritoneal abrasion. Japanese white rabbits underwent a midline laparotomy followed either by a bilateral peritoneal sidewall abrasion (4 x 4 cm) or an abrasion of liver surface (3 x 2 cm). The injured surface was then covered with a 0.2 mm thick DAC-80 membrane. On postsurgical day 2, the rabbits were sacrificed and the amounts of postsurgical bleeding was determined by quantitating the number of red blood cells recovered in 50 ml peritoneal lavage fluid. The DAC-80 membrane was found to reduce postsurgical bleeding after the abrasion of liver surface (treated with DAC-80 membrane: 2.9 +/- 0.8; control: 24.6 +/- 5.9 x 10(8) cells/peritoneal cavity, P less than 0.005). This same hemostatic activity was not observed after application in the peritoneal sidewall abrasion model. We also measured plasminogen activator activity (PA) and urokinase inhibitory (PAI) activity in the spent culture media of macrophages recovered from the postsurgical peritoneal exudate. The DAC-80 membrane reduced the PA secretion from postsurgical macrophages after liver surface abrasion (treated with DAC-80: 2.8 +/- 0.7; control: 3.9 +/- 0.9 mPU/ml). The DAC-80 membrane also showed similar effects on PA secretion after peritoneal sidewall abrasion. No significant effects were found in the secretion of PAI by postsurgical macrophages in both surgical models. These findings suggest that the DAC-80 membrane may have hemostatic activity through the modulation of fibrinolytic activity of peritoneal exudative macrophages.

Adolescent↗
PubMed1992

A clinical study of postoperative infections following open-heart surgery: occurrence and microbiological findings in 782 cases.

A total 782 consecutive patients underwent open-heart surgery with CPB between January, 1979 and December, 1988, at the Yamagata University Hospital. We assessed the incidence of postoperative infections in relation to age, the duration of surgery and antibiotic prophylaxis, and examined the causative organisms, after which the types of infecting flora were compared between the 1st period, from 1979 to 1983 and the 2nd period, from 1984 to 1988. Postoperative infection occurred in 104 of the 782 patients (13.3 per cent); in the form of a wound infection in 41 (5.2 per cent), pneumonia in 33 (4.2 per cent), urinary tract infection in 9 (1.2 per cent), prosthetic valve endocarditis in 6 (0.8 per cent), and other infections in 15 (1.9 per cent). Patients aged under 12 months or over 60 years showed a higher incidence of infection, being 17.4 per cent and 19.2 per cent, respectively. Patients who underwent an operation of over 8 hours duration also had a significantly higher incidence compared to those whose operation time was less than 4 hours, being 32.9 per cent and 6.3 per cent, respectively (p less than 0.0001). There was no significant difference in the incidence of postoperative infection between patients given or not given preoperative prophylaxis. A total 123 species of organisms were isolated from the 104 patients, 52.8 per cent being gram-negative bacteria (GNB), and 43.9 per cent gram-positive bacteria (GPB), and a remarkable increase in the incidence of GPB was seen in the 2nd period compared to the 1st period from 31.7 per cent to 50.0 per cent.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Molecular characterization and heterogeneity of feline immunodeficiency virus isolates.

We have molecularly cloned the complete genomic DNA of TM2 strain of feline immunodeficiency virus (FIV) isolated in Japan and compared its nucleotide and the deduced amino acid sequence with those of previously described U.S. isolates, FIV Petaluma and FIV PPR. The infectious molecular clone of FIV TM2 is different from FIV Petaluma in host cell range; the clone can not infect Crandell feline kidney cells which were permissive for FIV Petaluma. The amino acid sequence homologies, in gag, pol, and env genes between FIV TM2 and Petaluma were 90%, 87%, and 81%, respectively. On the other hand, comparative analysis of each gene between FIV Petaluma and PPR showed 96,95, and 85%, respectively. These results suggested that the genomic diversity was present among FIV strains isolated from geographically distant areas. Interestingly, tat- and rev-like short open reading frames contained inframe stop codons in the FIV Petaluma but not in the FIV TM2.

Amino Acid Sequence↗
PubMed1992

Biological characterization of human immunodeficiency virus type 1 and type 2 mutants in human peripheral blood mononuclear cells.

Mutants of human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2), which have been shown to be infectious in established cell lines, were tested for ability to replicate and induce syncytium formation in human peripheral blood mononuclear cells (PBMC). The vpu mutant of HIV-1 showed depressed kinetics of replication in an established T cell line, as reported previously, but in PBMC, its replication was similar to that of the wild type virus. The vpx gene of HIV-2 was required for efficient virus propagation in PBMC, but not in an established T cell line, as previously reported. However, the growth rates of the vpx mutant in PBMC preparations from two individuals were different. The results of experiments on infection of PBMC with the vif and vpr mutants of HIV-1 and HIV-2 were essentially consistent with previous results of infection of established T cell lines. No negative effect of the nef gene products of HIV-1 and HIV-2 was observed. The abilities of the wild type virus and the mutants of HIV-1 to induce syncytium formation in both PBMC and established cell lines were similar. In contrast, neither the wild type nor any of the mutants of HIV-2 induced syncytium formation in PBMC. These results suggest that the functions of some genes can be detected only in mixed populations or primary cells such as PBMC. Studies on the roles of these genes in PBMC may provide a better understanding of their functions in vivo.

Cells, Cultured↗
PubMed1992

Isolation and characterization of a highly divergent HIV-2[GH-2]: generation of an infectious molecular clone and functional analysis of its rev-responsive element in response to primate retrovirus transactivators (Rev and Rex).

A highly divergent HIV-2 designated as HIV-2[GH-2] was obtained from an AIDS-related complex (ARC) patient in Ghana. A full-length molecular clone of this isolate was obtained and a biologically active clone was constructed. Its restriction pattern differed from that of prototype HIV-2[GH-1] in 25 of 35 restriction sites, but was strikingly similar to a previously characterized HIV-2 isolate from a Ghanaian (HIV-2ALT). The conserved integrase region (288-bp fragment) previously displayed 95% identity with that of ALT but 17-20% divergence from the HIV-2 prototype member, and a new distinct subgroup (HIV-2b) of HIV-2 consisting of GH-2 and ALT was postulated (Miura et al. 1991.) These isolates, however, were biologically distinguishable from each other by its replication capacity in a monocyte line, U937, in which GH-2 could not grow but ALT grew well. In addition, the nucleotide sequence of the LTR of this new isolate displays 21% divergence from that of prototype HIV-2[GH-1], but the core enhancer, Sp1 binding sites and TATA box were conserved. Although the 3' half of the env gene sequence which is deleted in HIV-2ALT clone showed 27% diversity from the prototype, functional differences in the rev-responsive element were not observed.

Cloning, Molecular↗