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Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 271 records · Page 15Linked to original sources
PubMed1992

[Coronary revascularization with bilateral internal thoracic artery grafts].

Thirty-two patients underwent coronary revascularization with bilateral internal thoracic artery (ITA) grafts. Each patient received 2.7 grafts in average including double ITA grafts. Seventeen patients had the right ITAs as free grafts. The other sixteen were treated with 13 autologous veins and 9 right gastroepiploic arteries in addition. Fifty-five grafts out of 56 (98.2%) were proved to be patent at the time of hospital discharge. The postoperative morbidity included three reoperations for bleeding and one perioperative inferior myocardial infarction. One patient died of colon perforation after surgery and another died of cerebral infarction late after surgery. These results exhibited that coronary artery bypass grafting with bilateral ITA grafts had relatively low risks and could contribute to complete revascularization in patients with diseased coronary arteries.

Aged↗
PubMed1992

[Pharmacokinetic, bacteriological and clinical studies on cefprozil in pediatric patients].

Cefprozil (CFPZ, BMY-28100), a new oral cephem antibiotic, was studied for its antibacterial activities, absorption and excretion upon administration. Its clinical efficacies were also studied in pediatric patients with infections. A study on antibacterial activities of CFPZ against 11 clinical isolates including 6 species found that its activities against Staphylococcus aureus, alpha-hemolytic Streptococcus, Escherichia coli and Haemophilus influenzae were equal or superior to those of CCL. When CFPZ was given to patients orally at 15 mg/kg, maximum serum concentration was obtained between 1 to 2 hours after administration and urinary excretion rate in the first 6 hours was 33.8 +/- 17.6%. Clinical evaluation was done in a total of 25 patients with various infections. Responses were excellent in 15 cases and good in 10 cases, hence the efficacy rate was 100%. As side effect, soft stool was found in 1 case, and eosinophilia in 2 cases and elevation of GOT and GPT in 1 case were found as abnormal laboratory test results, but none of them was serious. It appears that CFPZ is an effective and safe antibiotic in the field of pediatrics.

Bacteria↗
PubMed1991

Complete sequence of human cardiac alpha-myosin heavy chain gene and amino acid comparison to other myosins based on structural and functional differences.

We have obtained the 5820 nucleotide sequence encoding all 1939 amino acids of the human cardiac alpha-myosin heavy chain (alpha-MHC), as established by dideoxy sequencing of cloned cDNA, genomic DNA and polymerase chain reaction (PCR) amplification products. This sequence represents overlapping fragments of the entire coding sequence. Amino acid sequence comparison of the human cardiac alpha-MHC with the published human cardiac beta-MHC have demonstrated that there are, at least, 7 isoform-specific divergent regions, including functionally important binding protein-related sites such as ATP, actin and myosin light chain. It has been reported that in the rat, there are 8 isoform-specific divergent regions. The 7th divergent area (residue area 1633-1657, which is thought to mediate thick filament formation) in the light meromyosin region in the rat is not apparent in the human. The amino acid compositions of cardiac alpha- and beta-MHCs in the human and the rat, and human embryonic skeletal muscle and chicken gizzard smooth muscles were compared. Amino acid sequences in cardiac alpha- and beta-MHCs in the human and the rat are well conserved. In the head portion, the amino acid composition divergence of human cardiac alpha-MHC is ranked between rat cardiac alpha-MHC and human cardiac beta- or rat cardiac beta-MHC; human skeletal muscle MHC is the most divergent of the myosin isoform examined. These data predict that human cardiac alpha-MHC may have undergone evolutionary changes toward obtaining the biochemical and physiological properties of cardiac beta-MHC.

Amino Acid Sequence↗
PubMed1991

Effect of lard, palm and rapeseed oils life conservation in aged mice.

Effects of lard, palm and rapeseed oil diets on the survival and fatty acid composition of liver and brain lipids were studied in male and female mice for 15 months. Over 80% of mice fed on lard and rapeseed oil (n-3 PUFA sufficient) diets survived to the end of feeding trial, however, 60% of male mice fed on palm oil (n-3 PUFA deficient) diet died before the end. Although a survival curve in female mice fed on palm oil diet was similar to that in male, it was not as dramatic as that of the male. The fatty acid analyses revealed that severe n-3 PUFA deficiency occurred in the mice fed on a palm oil diet. Moreover, the fatty acid was more deficient in the male than in the female. These results suggest that short life in mice may be caused by n-3 PUFA deficiency and, therefore, the fatty acid may be essential in enjoying a long life.

Aging↗
PubMed1991

Effector phenotypes and mechanisms of antitumor immune reactivity of tumor-immunized and tumor-bearing mice in two syngeneic tumors.

By using two different syngeneic tumors, Meth A sarcoma and RL male 1 lymphoma of BALB/c origin, the present study was designed to investigate the subset(s) of T cells mediating in vivo antitumor immune responses and some of the effector mechanisms of in vivo protective immunity in BALB/c mice immunized against tumor or bearing tumor. Spleen cells from the mice immunized against Meth A tumor or bearing Meth A tumor inhibited the growth of Meth A tumor in the Winn assay. In the Meth A-immunized mice, L3T4+ (CD4+) cells played a major role in mediating the inhibitory activity against Meth A tumor growth, whereas in the Meth A-bearing mice, the antitumor protective immunity was mediated by both L3T4+ and Lyt-2+ (CD8+) cells. Spleen cells from the Meth A-immunized or Meth A-bearing mice were not able to generate cytotoxic T lymphocytes (CTL) directed against Meth A tumor after the in vitro restimulation of spleen cells with mitomycin C (MMC)-treated Meth A cells, while fresh spleen cells from the Meth A-immunized or Meth A-bearing mice were able to induce the strong delayed-type hypersensitivity (DTH) responses to Meth A tumor. The DTH response to Meth A tumor was mediated by L3T4+ cells in the Meth A-immunized mice and by both L3T4+ and Lyt-2+ cells in the Meth A-bearing mice. In the similar experiments performed in the RL male 1 lymphoma, the antitumor activity in spleen cells from the RL male 1-immunized or RL male 1-bearing mice depended on Lyt-2+ but not L3T4+ cells in the Winn assay. When spleen cells from the RL male 1-immunized or RL male 1-bearing mice were cultured with MMC-treated RL male 1 cells for 5 days, an appreciable CTL response to RL male 1 tumor was induced. These results suggest that the nature of tumor and/or tumor antigens determines which T cell subset is required to exhibit the protective immunity against tumor and thus the different effector mechanisms could be induced in the different tumor models. Furthermore, these data support the conclusion that antitumor T cell responses are affected by the immune state of host to tumor.

Animals↗
PubMed1991

Molecular cloning and gibberellin-induced expression of multiple cysteine proteinases of rice seeds (oryzains).

We screened a cDNA library of germinating rice seeds with a cDNA for aleurain (cysteine proteinase from barley) and obtained three distinct types of cDNA clones encoding three species of cysteine proteinases (oryzains alpha, beta, and gamma). The deduced amino acid sequences are distinct in part, but, on the whole, are similar to one another. The three sequences all contain the catalytic triad Cys25-His159-Asn175 (papain numbering). The three oryzains are similar to one another and also to other known cysteine proteinases such as papain and cathepsin H with respect to the sequences around the active site residues and the COOH-terminal Trp-rich region. Amino acid sequence comparison revealed that oryzains alpha and beta are similar not only to each other (70% similarity) but also to actinidin and papain (about 50%), whereas oryzain gamma was rather similar to aleurain (85%) and cathepsin H (60%). Northern blot analysis revealed that the mRNAs for the three oryzains are expressed only in seeds, not in shoots or roots, and show different expression profiles during germination and when the seeds are treated with gibberellic acid. Oryzains alpha and gamma are expressed continuously during germination with a maximum expression 5 days from the start of germination, but are present in neither ripening nor ripened seeds. On the other hand, oryzain beta is expressed not only during germination, but also in ripened seeds before germination. It was noted that the expression of the three oryzain mRNAs is enhanced in different manners by gibberellic acid but is not enhanced by other plant hormones such as auxin. The induction of oryzain beta mRNA is transient, reaching a maximum in 4 h from the addition of giberellic acid and diminishing rapidly thereafter, while the induction of oryzain alpha and gamma mRNAs continues over 5 days. Thus, multiple systems involving cysteine proteinases must be differentially involved in the germination process, probably under hormonal control.

Amino Acid Sequence↗
PubMed1991

Gene organization of oryzacystatin-II, a new cystatin superfamily member of plant origin, is closely related to that of oryzacystatin-I but different from those of animal cystatins.

The gene structure of oryzacystatin-II, a new cystatin superfamily member of rice seed origin, was determined. It spans approximately 2.5 kbp and comprises 3 exons. The number of exons and the intron-breakpoints coincide with those of oryzacystatin-I, the first well-defined plant cystatin. However, no similar sequences were observed between the two oryzacystatin genes in 5'-upstream regulatory regions, even though both are expressed specifically during the ripening stage of rice seeds. The gene organization of these two plant cystatins is generally different from that of animal cystatins.

Amino Acid Sequence↗
PubMed1991

Calcitonin gene-related peptide immunoreactivity in spinal spheroids in motor neuron disease.

The spinal cords from seven autopsy cases of sporadic motor neuron disease (MND) and two controls were immunohistochemically examined using antibodies directed to calcitonin gene-related peptide (CGRP) and to neurofilament proteins (Nf). CGRP immunoreactivity was observed in the posterior horns, especially in the laminae I and II, of all the spinal cords examined. In MND cases, in addition, a considerable number of spheroids in the anterior horns were labelled with the antibody. In some spheroids, their entire area was homogeneously immunostained, whereas in others the immunoreactivity was confined to a focal area(s) within the profile of the spheroids and between these two forms of staining several variations of the staining patterns were seen. The anti-Nf intensely and homogeneously labelled all spheroids and there was no appreciable difference in the Nf-immunoreactive pattern between CGRP-positive and -negative spheroids. It is possible that the accumulation of CGRP in spheroids may result from entrapment of CGRP during the anterograde axonal transport, causing loss of CGRP at the neuromuscular junction and producing weakness and atrophy of the muscles.

Aged↗
PubMed1991

Cutaneous tumour-like lesions due to poxvirus infection in Chilean flamingos.

Cutaneous tumour-like growths were observed on the face and other areas of the body surface of young Chilean flamingos. In the cells of these lesions, avian pox-specific cytoplasmic inclusion bodies were observed by light microscopy and virus particles were detected under an electron-microscope. It was diagnosed as avian pox.

Animals↗
PubMed1991

[Role of transiently accumulated neutrophils in the lung of hamster in development of pneumonia due to Mycoplasma pneumoniae].

The importance of Mycoplasma pneumoniae as a pathogen of human infectious diseases, particularly of respiratory infections, has been well recognized. However, the details of the mechanism through which lung tissue damages are produced in mycoplasmal infection has not been fully understood. It has been pointed out that beside the direct invasive process certain immunological responses to the deposited microbes are crucial in development of mycoplasmal pneumonia. In the present study, we aimed at elucidating the role of neutrophils in producing pneumonia due to Mycoplasma pneumoniae in hamsters. For this purpose, hamsters were divided into two groups; the one not pretreated and infected with Mycoplasma pneumoniae and the other immunosuppressed by 60Co irradiation and infected. A serial determination of the numbers of mycoplasmal cells recovered from the treacheal tissue and bronchoalveolar lavage fluid (BALF) and analysis of cellular components in BALFs were carried out. The severity and the nature of pathological changes produced in the lungs were evaluated and scored on the basis of microscopic findings. As a result, it was found that the numbers of mycoplasmal cells recovered from both tracheal tissues and BALFs reached maximum on the seventh day of infection in both groups and decreased rapidly. There no apparent difference was found between the two groups in number of cells recovered. In the not-irradiated control groups, the percentage of polymorphonuclear leukocytes (PMNs) in BALF was very high on the seventh day and then they were replaced by lymphocytes by the 21st day of infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Use of ventricular assist devices in patients with postcardiotomy shock.

Over the last three years, we have used ventricular assist devices (VAD) in 7 patients. Of these 7, four patients with combined aortic and mitral valvular disease underwent double valve replacement; one patient with annuloaortic ectasia underwent a Cabrol's operation; another had aortic valve replacement; the last patient had triple coronary artery bypass grafts. The only patient who could be weaned from CPB developed cardiogenic shock after the operation. LVADs supported 6 patients for 4 to 8 days and a BVAD supported one patient for 9 days. All patients survived the weaning procedure. Three were discharged from the hospital and survived 7 to 21 months. The 4 other patients died of multiple organ failure. Three of these four suffered from both renal failure and infection, while one patient had arrhythmia and died of ileus. These data suggest that renal failure and major infection can be serious detrimental complications to VAD support.

Adult↗
PubMed1991

[Cross reactive antigens of Acholeplasma laidlawii and L-form of Staphylococcus aureus].

We demonstrated that the membrane of Acholeplasma laidlawii PG8 and L-form of Staphylococcus aureus, both of which induce cellular immunity in BALB/c mice, were antigenically related each other. Foodpad responses of the mice immunized with a mixture of either antigen and Freund's complete adjuvant showed clearly a cross reaction when challenged with the other antigen. Cross responses to incorporate 3H-thymidine to the spleen lymphocytes of the mice immunized with either antigen occurred in the presence of the other antigen. Furthermore, the purified T cells, but not B cells, of the spleen were activated in the presence of antigen-presenting cells. These antigens existing in the membrane fractions of both microorganisms were purified by Razin's method. Finally, these membrane components of A. laidlawii and L-form of S. aureus were subjected to gel electrophoresis and transferring to nitrocellulose membrane and used to stimulate the spleen lymphocytes of the mice immunized with A. laidlawii or of non-immunized mice. The fractions representing molecular weights of approximately 45 kD, 25 kD, and 13 kD of both microorganisms consistently stimulated the lymphocytes of the immunized mice but not those of non-immunized mice.

Acholeplasma laidlawii↗
PubMed1991

Oryzacystatins as the first well-defined cystatins of plant origin and their target proteinases in rice seeds.

Two cystatins occur in mature seeds of the rice, Oryza sativa L. japonica, which are named oryzacystatin I (OC-I) and oryzacystatin II (OC-II). These are highly homologous to each other and are significantly homologous to cystatin superfamily members of animal origin, especially to family-2 cystatins. However, both lack disulfide bonds as in the case of family-1 cystatins (stefins). Each of OC-I and OC-II thus seems to be chimerical of family-1 and family-2 cystatins, and we propose that a new category such as "phytocystatin" be opened for these cystatins of plant origin. For specificity it was observed that OC-I inhibits papain 100 times more efficiently than cathepsin H, whereas, OC-II inhibits cathepsin H 100 times more efficiently than papain. A cysteine proteinase, named oryzain alpha, exists in germinating rice seeds. cDNA cloning studies have disclosed that two other related species, named oryzain beta and gamma, are also present. In respect to the amino acid sequence, oryzain alpha and beta are homologous to papain and oryzain gamma is homologous to cathepsin H. These observations suggest the possibility that either or both of oryzain alpha and beta are target enzymes of OC-I and oryzain gamma is a target enzyme of OC-II.

Amino Acid Sequence↗
PubMed1991

Papain-inhibitory activity of oryzacystatin, a rice seed cysteine proteinase inhibitor, depends on the central Gln-Val-Val-Ala-Gly region conserved among cystatin superfamily members.

Oryzacystatin, a cysteine proteinase inhibitor occurring in rice seeds, contains a particular glycine residue (Gly5) near the NH2-terminal position, and the sequence Gln53-Val54-Val55-Ala56-Gly57 in a central part of the molecule. Both are conserved among most members of the cystatin superfamily. We have found from Escherichia coli expression studies that the NH2-terminal 21 residues of oryzacystatin are not essential for its papain-inhibitory activity, and that the conserved pentapeptide region may be indispensable [Abe, K., Emori, Y., Kondo, H., Arai, S., & Suzuki, K. (1988) J. Biol. Chem. 263, 7655-7659]. Here we present more detailed data based on quantitative analyses of the inhibitory activities of NH2- and COOH-terminally truncated oryzacystatin and site-directed mutants at the Gln-Val-Val-Ala-Gly region. The data indicate the following results. (1) The truncated mutants lacking the NH2-terminal 21 residues or the COOH-terminal 11 residues exhibit potent papain-inhibitory activity equivalent to the activity of wild oryzacystatin. (2) However, neither the mutant lacking the NH2-terminal 38 residues nor that lacking the COOH-terminal 35 residues is completely able to inhibit papain. (3) Site-directed mutants at the Gln residue of the Gln-Val-Val-Ala-Gly region have drastically reduced papain-inhibitory activities: the Gln----Pro mutant is completely inactive and the Gln----Leu mutant has an approximately 150 times higher Ki value than wild-type oryzacystatin.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

[Comparison of noninvasive techniques in evaluation of the Björk-Shiley and the St. Jude Medical valve prostheses in mitral position].

Pressure gradients and left ventricular function were assessed by Doppler echocardiography in 50 patients with Björk-Shiley mitral valve and 50 patients with St. Jude Medical valve prosthesis. There was correlation between pressure gradient and valve size, and between effective valve orifice area and valve size for St. Jude Medical valve. These correlations were not found in Björk-Shiley valve. Clinical improvement and cardiac function were quite satisfactory in 20 patients with Björk-Shiley valve and in 32 patients with St. Jude Medical valve whose pressure gradients were less than 10 mmHg. Twenty eight of 50 patients with Björk-Shiley valve and 42 of 50 patients with St. Jude Medical valve showed good response to the exercise test. Eight patients underwent reoperation because of unacceptably high gradient caused by thrombus and pannus formation. The patients who show high pressure gradient across the valve prosthesis should be followed up cautiously.

Cardiac Volume↗