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Biomedical subjects

M Kawamura

Publications and source records attributed to M Kawamura.

At least 199 records · Page 11Linked to original sources
PubMed1998

[Coronary artery bypass grafting under the excellent heart exposure provided by the use of the coronary artery exposing tape].

We have used the coronary artery exposing tape devised by Akio Matsuura in 93 patients undergoing coronary artery bypass grafting. We could perform graft anastomosis more easily and safely by the use of this tape than by the conventional simple compression method of the heart with the gauzes. The heart was lifted anteriorly with the rotation by the tape pulled to the left side or to the caudal side. The right coronary artery branches were exposed excellently by the simple traction of the tape to the caudal side. The circumflex coronary artery branches were well exposed by one tape pulled to the left side and another tape to the right side over the heart with the counterclockwise rotation of the heart. In these procedures no complication was encountered in association with the traction of this tape.

Adult↗
PubMed1998

[A case of pulmonary infection with mycobacterium xenopi].

A 42-year-old man with pulmonary disease caused by Mcobacterium xenopi is described. He had a history of alcohol use of over 20 years. He was admitted to another hospital for evaluation of an abnormal chest shadow. A chest X-ray showed a cavitary shadow with infiltration in the right upper lung field. Acid-fast organisms were recognized in sputum and M. xenopi was identified by DNA-DNA hybridization. Although he had been treated with isoniazid, rifampicin, and ethanbutol for 5 years, sputum remained positive on culture and chest X-ray findings did not improve. He was later admitted to our hospital for surgery, and right upper lobectomy was performed. He has remained well for 18 months since the operation. In Japan, cases of the pulmonary infection with M. xenopi are rare. Surgical resection is required when chemotherapy is unsuccessful.

Adult↗
PubMed1998

Inhibition of human immunodeficiency virus type 1 replication and cytokine production by fluoroquinoline derivatives.

We have recently identified 8-difluoromethoxy-1-ethyl-6-fluoro-1, 4-dihydro-7-[4-(2-methoxyphenyl)-1-piperazinyl]-4-oxoquinoline-3-carb oxylic acid (K-12) as a potent and selective inhibitor of human immunodeficiency virus type 1 (HIV-1) transcription. In the search for more effective derivatives and their mode of action, we have found 7-(3,4-dehydro-4-phenyl-1-piperidinyl)-1, 4-dihydro-6-fluoro-1-methyl-8-trifluoromethyl-4-oxoquinoline-3- carboxylic acid (K-37) and 8-difluoromethoxy-1,4-dihydro-6-fluoro-7-(3, 4-dehydro-4-phenyl-1-piperidinyl)1-[4,(1,2, 4-triazol-1-yl)methylphenyl]-4-oxoquinoline-3-carboxylic acid (K-38) to be more potent inhibitors of HIV-1 replication than K-12. The EC50 values of K-37 and K-38 for HIV-1IIIB were 27 and 3.8 nM in peripheral blood mononuclear cells, respectively. These values were approximately 3- and 24-fold lower than the EC50 of K-12. K-38 was also a more potent inhibitor of HIV-1 replication in chronically infected cells, such as tumor necrosis factor alpha-stimulated OM-10. 1 cells. K-37 and K-38 proved to be more cytotoxic than K-12 for a variety of cell lines as well as peripheral blood mononuclear cells. These compounds were more inhibitory of Tat-induced HIV-1 long terminal repeat-driven gene expression than K-12, which suggests that their mechanism of action is attributable in part to the inhibition of Tat function. Interestingly, K-37 and K-38 could suppress the production of tumor necrosis factor alpha and interleukin 6 in phytohemagglutinin-stimulated peripheral blood mononuclear cells and the expression of intercellular adhesion molecule 1 in tumor necrosis factor alpha-stimulated human umbilical vein endothelial cells at their nontoxic concentrations. In contrast, another K-12 derivative, 1, 4-dihydro-8-dimethylaminomethyl-6-fluoro-7-[4-(2-methoxyphenyl)-1-pip eradinyl]-1-methyl-4-oxoquinoline-3-carboxylic acid (K-42), had anti-HIV-1 activity and cytotoxicity profiles similar to those of K-12, but K-42 scarcely inhibited the cytokine production and intercellular adhesion molecule 1 expression.

Anti-HIV Agents↗
PubMed1998

[The long-term anterior chest wound pain after the cardiac surgery].

We discussed on the long-term anterior chest wound pain after the cardiac surgery by using a questionnaire. The risk of the left anterior chest wound pain was high significantly in the cases using the left internal thoracic artery compared with other cases. Participation of the division of the left upper pericardium and the adjacent soft tissue was highly suggested as the cause of this pain.

Adolescent↗
PubMed1998

[Coronary artery bypass grafting performed by the simple and convenient graft supporter].

We have experienced a simple, safe and convenient technique for supporting the arterial or saphenous vein graft in the coronary artery bypass grafting. This graft supporter is made of cotton cloth with a 50 percent polyester mix. The supporter is twenty centimeters long and two centimeters wide. This supporter provides the complete fixation of the graft without the holding by the co-operater. Therefore the supporter allows very easy, safe and accurate graft anastomosis with the native coronary artery or the ascendinbg aorta. No complication was encountered in association with this procedure in 127 operations.

Coronary Artery Bypass↗
PubMed1998

[Clinical analysis in patients undergoing extended resection of pT3 non-small cell lung cancer].

Among pT3 cases there contain various subgroups in terms of the organ which is involved in. We analyzed medical records of 85 consecutive patients who underwent extended surgery with diagnosis of pT3 excluding interlober invasion. As regards to the site of invasion, there are not significant differences in survival between pleural invasion, chest wall involvement, pericardial invasion, and diaphragmatic invasion. However, survival of patients who showed involvement of main bronchus seemed better than other groups. Survival of pT3 cases are in part determined by lymph node involvement, N0 group showed 36.0% 5 year survival rate whereas N1 group 20.0%, and there are no patient with N2 disease who survived 5 years. Among pleural and chest wall involvement group, N0 group showed 34.2% 5 year survival and there are no survival in N1 and N2 group. As regards to histologic subgroups, there are not significant differences between each group. Thus we conclude that in pT3 cases, N0 cases are the best candidate for surgical resection, and that adjuvant therapy is necessary for those with N1 or N2 involvement. Cases with bronchial extension should not be argued in the same field of locally invasive lung cancer because of better survival.

Adult↗
PubMed1998

[Difficulty in reaching objects due to posterior cerebral artery occlusion].

We reported two patients who developed an impairment of reaching movement with their right hand due to left posterior cerebral artery occlusion. Both patients showed abnormalities in reaching their own body parts with eyes closed, and in reaching objects presented before them with eyes fixed on the objects. No motor paralysis or ataxia was noted in either patient; nor was there any disturbance of the superficial or deep sensation except for a slight disturbance of articular localization of the right upper limb in one patient. The failure for these patients to reach their own body parts with eyes closed was thought to be caused by an impairment of kinesthesia of the right upper limb. The failure to reach objects with eyes fixed on them was also likely to be explained by the disturbance of kinesthesia besides the same mechanism as ataxie optique. CT scan revealed low density areas in the medial side of the left temporal and occipital lobes and left lateral pulvinar in both patients. These findings, together with anatomical and physiological findings in recent years, suggest that nerve fibers related to kinesthesia may be projected on the parietal association area via the lateral pulvinar.

Aged↗
PubMed1998

[The long-term anterior chest median wound keloid after the cardiac surgery].

We discussed on the long-term anterior chest median wound keloid after the cardiac surgery by using a questionnaire. The risk of the anterior chest median wound keloid was high significantly in the cases using the bilateral internal thoracic artery compared with the cases using no internal thoracic artery. Participation of the decreased blood supply was highly suggested as the cause of this keloid formation.

Adolescent↗
PubMed1998

Left ventricular free wall rupture following mitral valve replacement.

During a 10-year period, 110 patients underwent mitral valve replacement (MVR). We experienced three left ventricular ruptures among these patients. Two had a type I immediate rupture, and one had a type III delayed rupture. Two patients (type I, III) survived after repair of the rupture. It was possible to control bleeding by manual compression with oxidized cellulose, collagen mat and fibrin glue with or without external mattress sutures. Following the repair, an intra-aortic balloon pump and sedative agents were used in both patients. In the other patient with a type I early rupture, control of bleeding was attempted by external direct suture using Teflon felt. The bleeding was controlled by this repair and the use of a left ventricular assist device, but the patient died of a brain infarction 5 days after the operation. The manual compression technique using oxidized cellulose, collagen mat and fibrin glue may be useful for minor lacerations, and for reinforcing repairs. The intra-aortic balloon pump and continuous sedation are useful for unloading the ventricle and reducing the tension on repairs.

Aged↗
PubMed1997

Functional domain mapping of HIV-1 Gag proteins.

A series of human immunodeficiency virus type 1 (HIV-1) proviral gag gene mutants carrying bacterial CAT gene were constructed and monitored for the expression of reverse transcriptase and CAT in a highly sensitive single-round replication assay system to determine the defective replication phase in lymphocytic cells. All the mutants displayed no abnormality in the process of transcription and translation at late replication stage. In contrast, some matrix, capsid, and p6 mutants were defective at final phase, that is, assembly and virion release. Most of the mutants including nucleocapsid mutants, which showed normal phenotype at late stage, were defective at early replication phase. From the functional domain map thus obtained, it is evident that HIV-1 Gag proteins are required for both early and late replication phases.

CD4-Positive T-Lymphocytes↗
PubMed1997

Assembly of the chimeric Na+/K+-ATPase and H+/K+-ATPase beta-subunit with the Na+/K+-ATPase alpha-subunit.

Two sets of chimeric beta-subunits were constructed from subunits of Torpedo californica Na+/K+-ATPase and pig gastric H+/K+-ATPase. Five unique restriction sites (SnaBI, EcoRV, MunI, SphI and EcoT22I) were created at equivalent positions of the respective cDNAs and were used as joining points for the construction. One set of chimeras (HxN series) was made by exchanging the 5' portion of the Na+/K+-ATPase beta-subunit cDNA with the corresponding portion of the H+/K+-ATPase beta-subunit cDNA at the respective joining point. Complementary constructs were also prepared (NxH series). In the HxN series, the chimera joined at the SnaBI site formed a stable trypsin resistant complex with the Na+/K+-ATPase alpha-subunit, which was functional with respect to ATP hydrolysis and pump current generation, although the activities were less than those of the complex with the Na+/K+-ATPase beta-subunit. Trypsin resistance decreased for the complex of the chimera joined at the EcoRV site. In the NxH series, the chimeras joined at the SnaBI site and the EcoRV site formed rather trypsin-resistant complexes, but the expressions of the alpha-subunits were below 50% of the control. The chimeras joined at the MunI, SphI and EcoT22I site formed complexes susceptible to tryptic digestion. None of the chimeras in the NxH series were functional. These results suggest that at least two regions of the Na+/K+-ATPase beta-subunit [SnaBI site(Tyr40) to EcoRV site(Ile89) and EcoT22I site(Cys176) to C-terminus)] are involved in stable assembly with the Na+/K+-ATPase alpha-subunit and that the cytoplasmic domain [N-terminus to SnaBI site(Tyr40)] is functionally replaceable with the corresponding domain of the H+/K+-ATPase beta-subunit.

Amino Acid Sequence↗
PubMed1997

Interaction of mutagenic tryptophan pyrolysate with d(CGATCG)2: intercalation model based on NMR experiments.

The solution structure of the complex of 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1), a potent mutacarcinogen isolated from tryptophan pyrolysate, with the hexamer duplex d(CGATCG)2, was analysed by 1H-NMR spectroscopy and molecular dynamic calculation. Trp-P-1 was intercalated between the CpG base pairings in a suitable manner to form the guanosine-Trp-P-1 adduct which corresponds to the major reactant of Trp-P-1 with DNA.

Base Composition↗
PubMed1997

Effects of aldehyde/aldose reductase inhibition on neuronal metabolism of norepinephrine.

After norepinephrine (NE) is deaminated by monoamine oxidase (MAO), the aldehyde formed is either metabolized to 3,4-dihydroxy-mandelic acid (DHMA) by aldehyde dehydrogenase or is converted to 3,4-dihydroxyphenylglycol (DHPG) by aldehyde or aldose reductase. The present study examined the effects of inhibition of aldehyde and aldose reductase on production of DHPG and DHMA in rats. Mean (+/- S.E.) baseline plasma concentrations of DHPG (4.73 +/- 0.21 pmol/ml) were 60-fold higher than those of DHMA (0.08 +/- 0.01 pmol/ml). Inhibition of aldose and aldehyde reductase reduced plasma DHPG concentrations to 1.88 +/- 0.14 pmol/ml and increased plasma DHMA to 4.43 +/- 0.29 pmol/ml; additional inhibition of MAO reduced plasma DHPG to 0.16 +/- 0.06 pmol/ml and DHMA to 0.19 +/- 0.02 pmol/ml. Inhibition of aldehyde and aldose reductase also increased brain tissue levels of DHMA from 8 +/- 2 to 384 +/- 47 pmol/g and decreased levels of DHPG from 70 +/- 9 to 44 +/- 5 pmol/g. The results show that DHMA is normally a minor metabolite of NE, but becomes a major metabolite after aldehyde/aldose reductase inhibition.

Aldehyde Reductase↗
PubMed1997

Cleavage of Gag precursor is required for early replication phase of HIV-1.

A mutant of human immunodeficiency virus type 1 (HIV-1), which is deficient for Gag precursor cleavage and noninfectious, was characterized with respect to its defective step in the viral replication phase. Upon transfection, the mutant produced a normal level of progeny virions as monitored by electron microscopy and RNA hybridization. Single-round replication assay demonstrated, in contrast, that the mutant was defective at the early phase of the replication cycle. Furthermore, no viral DNA was detected in the cells infected with the mutant. Taken together, it is concluded that maturation of Gag precursor protein of HIV-1 is required for an early event(s) before or during a coupled process of uncoating/reverse transcription.

Blotting, Southern↗
PubMed1997

HIV-1 capsid mutants inhibit the replication of wild-type virus at both early and late infection phases.

In-frame mutations were introduced into various portions of the human immunodeficiency virus type 1 (HIV-1) gag gene, and potentials of the mutants to suppress the replication of wild-type HIV-1 were monitored. In contrast to results obtained with matrix and nucleocapsid mutants, almost all capsid mutants blocked HIV-1 replication completely in single-round replication assays. A capsid mutant designated C6b was demonstrated to be one of the most efficient inhibitors for HIV-1 reported to date, and to be effective at both early and late viral replication phases. T-cells, which are engineered to express the C6b Gag in response to HIV-1 infection, were perfectly resistant to HIV-1.

Blotting, Western↗