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Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 289 records · Page 16Linked to original sources
PubMed1991

[A case report of advanced gastric cancer responsive to radiotherapy and CDDP arterial injection].

A 48-year-old-male patient with advanced gastric cancer, which extended from corpus to antrum of the stomach and metastasized to the left lobe of the liver, was treated with radiotherapy combined with CDDP arterial injection. Total irradiation and CDDP dosage was 50 Gy/25 f and 150 mg (75 mg/mal/body), respectively. The regression of the tumor was remarkable. For inoperable advanced gastric cancer, radiotherapy combined with anticancer drugs proved a worthwhile therapy, and it was necessary to use the pharmacological characteristics of the drugs.

Adenocarcinoma↗
PubMed1991

[Experimental study on avoidance of surgical heart block in septation for single ventricle].

A new method was developed to prevent surgical injury of the atrioventricular conduction system in septation for single ventricle. The new method includes the use of small Teflon pledgets to cover the conduction system at the crossing sites of suture line, and so that stitches can be placed on the pledgets to skip the conduction system. This paper describes the results of an experimental study to delineate the effects of covering pledgets on the morphology and function of the underlying conduction tissues. Deep hypothermia was employed for this experiment in 15 mongrel dogs. The small Teflon pledgets were sutured to bridge the endocardial surface of the atrioventricular node through the right atriotomy. They were subjected to sacrifice at 1 week to 12 months postoperatively. Electrophysiological study including electrocardiography. His bundle electrography and responsiveness of the atrioventricular conduction to rapid stimulation was done before the sacrifice. The resected heart was embedded in Ceroidin-Paraffin and serially sectioned for pathological study. No noticeable injuries were noted in the underlying conduction system. The electrophysiological study showed normal sinus rhythm at the time of sacrifice. No significant changes were noted in PQ intervals comparing to preoperative state. There were no significant differences in AH intervals, HV intervals and responsiveness to rapid atrial stimulation between experimental and normal control groups. In conclusion, the Teflon felt pledgets were demonstrated to have no detrimental effects on the atrioventricular conduction system in the chronic stage.

Animals↗
PubMed1991

[Real time microscopic image transmission system by using Hi-vision technique].

Using a high definition television (HDTV) technique, we have designed and developed the real time microscopic image transmission system. The department of laboratory and pathology, 500 m apart, are connected by this system on a light fiber line. It consists of an electrically controlled microscope, a HDTV camera, a HDTV color monitor, and a video transmitter on the laboratory side, while on the pathology a remote microscope controller, a video receiver, and a HDTV color monitor of 22.5 (H)-39.5(W) cm in CRT size. By monitoring real time noiseless picture, pathologists can select the objective lenses, move the stage, and adjust the focus of microscope at their own office. Three-month trial revealed that this prototype system was quite useful for prompt histo-pathological diagnosis during surgical operations. So far as we know, this microscopic image transmission system with Hi-vision TV is the first one in practical use in this field.

Microscopy↗
PubMed1990

Two distinct cystatin species in rice seeds with different specificities against cysteine proteinases. Molecular cloning, expression, and biochemical studies on oryzacystatin-II.

Oryzacystatin (oryzacystatin-I) is a proteinaceous cysteine proteinase inhibitor (cystatin) in rice seeds and is the first well defined cystatin of plant origin. In this study we isolated cDNA clones for a new type of cystatin (oryzacystatin-II) in rice seeds by screening with the oryzacystatin-I cDNA probe. The newly isolated cDNA clone encodes 107 amino acid residues whose sequence is similar to that of oryzacystatin-I (approximately 55% of identity). These oryzacystatins have no disulfide bonds, and so could be classified as family-I cystatins; however, the amino acid sequences resemble those of family-II members more than family-I members. Oryzacystatin-I and -II are remarkably distinct in two respects: 1) their specificities against cysteine proteinases; and 2) the expression patterns of their mRNAs in the ripening stage of rice seeds. Oryzacystatin-I inhibits papain more effectively (Ki 3.0 x 10(-8) M) than cathepsin H (Ki 0.79 x 10(-6) M), while oryzacystatin-II inhibits cathepsin H (Ki 1.0 x 10(-8) M) better than papain (Ki 0.83 x 10(-6) M). The mRNA for oryzacystatin-I is expressed maximally at 2 weeks after flowering and is not detected in mature seeds, whereas the mRNA for oryzacystatin-II is constantly expressed throughout the maturation stages and is clearly detected in mature seeds. Western blotting analysis using antibody to oryzacystatin-II showed that, as is the case with oryzacystatin-I, oryzacystatin-II occurs in mature rice seeds. Thus, these two oryzacystatin species are believed to be involved in the regulation of proteolysis caused by different proteinases.

Amino Acid Sequence↗
PubMed1990

Mycoplasma can enhance HIV replication in vitro: a possible cofactor responsible for the progression of AIDS.

Mycoplasma membrane protein (MMP) augmented HIV production from MOLT-4 cells chronically infected by HIV. A nearly 3-fold increase of HIV p24 antigen was detected in MMP-treated culture as compared to control culture at 100 micrograms/ml. MMP also augmented HIV production in different T cells chronically infected by HIV-1 and ARV-1. Kinetic experiment showed that HIV production was maximally elevated 24 hr after exposure to MMP. Similarly, MMP also augmented HIV-induced cell fusion and virus production in coculture. Hybridization experiment revealed that this augmentation was due to enhancement of HIV transcription.

Antibodies, Monoclonal↗
PubMed1990

Mycoplasma and AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Comparative study on the innervation of nerves with calcitonin gene-related peptide, substance P and neurokinin A immunoreactivity in the walls of the cerebral arteries of small bats (Mammalia: Microchiroptera).

The distribution and origin of nerves with calcitonin gene-related peptide, substance P or neurokinin A immunoreactivity in the walls of the cerebral arteries were investigated in three microchiropteran species. The supply of nerves immunoreactive for substance P and neurokinin A to the bat cerebral arteries is confined mostly to the vertebral and basilar arteries. The density of innervation of calcitonin gene-related peptide-immunoreactive nerves and that of nerves with substance P or neurokinin A immunoreactivity in the vertebrobasilar system differ among species: the Japanese large footed bat is innervated with nerves with calcitonin gene-related peptide, substance P and neurokinin A immunoreactivity with about the same density, whereas in the greater horseshoe bat, there are many substance P-immunoreactive nerves with very weak or no calcitonin gene-related peptide immunoreactivity, and in the bent-winged bat, calcitonin gene-related peptide immunoreactivity is not found in all nerves with substance P immunoreactivity in the pial arteries of all parts of the brain. Nearly all cells immunoreactive for substance P, calcitonin gene-related peptide or both in the trigeminal and cervical dorsal root ganglia were small. In the greater horseshoe bat and the bent-winged bat, there is a correlation between the level of expression of substance P and calcitonin gene-related peptide immunoreactivity in the cervical dorsal root and trigeminal ganglia and the cerebral perivascular nerves supplying the vertebrobasilar system. The cerebrovascular innervation of nerves with substance P immunoreactivity in small bats is similar to that of cats and guinea-pigs in which the trigeminal ganglia have been destroyed. These observations, in addition to absence of nerve cells showing substance P or calcitonin gene-related peptide immunoreactivity in the pial artery and in the nerve bundles accompanying the extracranial internal carotid and vertebral arteries, suggest that substance P-immunoreactive nerves with or without immunoreactivity to calcitonin gene-related peptide in the vertebrobasilar system of small bats originate exclusively from the cervical dorsal root ganglia. The remaining fibres probably originate in the trigeminal ganglia.

Acetylcholinesterase↗
PubMed1990

Enhancement of cytotoxicity of active macrophages by mycoplasma: role of mycoplasma-associated induction of tumor necrosis factor-alpha (TNF-alpha) in macrophages.

Tumor necrosis factor-alpha (TNF-alpha)-inducing activity of several mycoplasmas including Mycoplasma pneumoniae, a causative agent in human respiratory infectious diseases, was investigated. Purified peritoneal macrophages from BALB/c mice markedly enhanced their cytotoxic activity to Meth A cells, when cultured with either viable or non-viable mycoplasmas. The supernatants of the macrophage culture with mycoplasmas, M. pneumoniae and Acholeplasma laidlawii, showed the potent cytotoxic activity to TNF-alpha-sensitive L cells but not to TNF-alpha-insensitive L cells. Addition of anti-TNF-alpha antiserum inhibited completely the cytotoxic activity of these supernatants, indicating that a major part of the cytotoxic activity might be due to TNF-alpha. Various other mycoplasmas, either glucose- or arginine-utilizing species, as far as tested showed also the potent activity to produce TNF-alpha. These results strongly suggest the possibility that mycoplasmas possess the activity of TNF-alpha induction which might be responsible for a part of enhancement of cytotoxic activity of macrophages and resistance to infection with mycoplasmas in vivo.

Animals↗
PubMed1990

Mycoplasmas induce transcription and production of tumor necrosis factor in a monocytic cell line, THP-1, by a protein kinase C-independent pathway.

We demonstrated that mycoplasmas (MP), previously shown to augment the antitumor activity of murine peritoneal macrophages, also induce cytotoxic activity in a human monocytic cell line, THP-1. THP-1 cells were induced to produce cytotoxic activity by MP in a time- and dose-dependent manner. By using neutralization by antibody against tumor necrosis factor (TNF), the cytotoxic activity was shown to be due to TNF released from the MP-stimulated cells. Studies with inhibitors of second-messenger pathways and Northern RNA blot analysis indicated that a Ca2(+)-dependent, but not protein kinase C-dependent, biochemical pathway is involved in MP-induced TNF production by THP-1 cells and that MP induce TNF production in the cells at the level of transcription. MP, unlike other bacteria, lack cell walls and lipopolysaccharide. The possible involvement of a TNF production mechanism distinct from that triggered by lipopolysaccharide is discussed.

Animals↗
PubMed1990

Characterization of two polysaccharides having activity on the reticuloendothelial system from the root of Glycyrrhiza uralensis.

Two polysaccharides, called glycyrrhizans UA and UB, were isolated from the root of Glycyrrhiza uralensis Fischer. They were homogeneous on electrophoresis and gel chromatography, and showed reticuloendothelial system-potentiating activity in a carbon clearance test. Glycyrrhizan UA is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid in the molar ratio of 20:14:1:3, and glycyrrhizan UB is composed of L-arabinose: D-galactose: D-glucose: L-rhamnose: D-galacturonic acid in the molar ratio of 12:10:1:10:20, in addition to small amounts of O-acetyl groups and peptide moiety, respectively. About 10% (glycyrrhizan UA) and 35% (glycyrrhizan UB) of the D-galacturonic acid residues exist as the methyl esters. Methylation analysis, carbon-13 nuclear magnetic resonance and periodate oxidation studies indicated their structural features.

Electrophoresis, Polyacrylamide Gel↗
PubMed1990

[Induction by Staphylococcus aureus L-form of tumor necrosis factor-alpha from macrophages].

Induction of tumor necrosis factor-alpha (TNF-alpha) by Staphylococcus aureus L-form was investigated. The supernatant of a macrophage culture mixed with S. aureus L-form showed a potent cytotoxic activity to L cells. Addition of anti TNF-alpha antibody inhibited completely the cytotoxic activity of the supernatant, indicating that the activity might be due mostly to TNF-alpha. To investigate localization of TNF-alpha production, the membranes of hypotonicity treated L-form were layered on a step-gradient composed of an upper and lower layers of 35% and 50% sucrose, respectively. The membranes were banded at the interface of 35% and 50% of sucrose. The activity of TNF-alpha production of the membrane fraction was 10-times higher than that of the soluble fraction.

Animals↗
PubMed1990

Therapeutic effects of cefpirome, a new cephalosporin, on various models of infections in mice and rats.

Cefpirome (HR 810) is a new cephalosporin with a 2,3-cyclopentenopyridine group in the 3-position side chain. It was compared with other cephem antibiotics in protective and therapeutic effects on various experimental infections, systemic and local, in mice and rats. HR 810 had more potent protective effect than ceftazidime (CAZ), cefoperazone (CPZ), and cefotaxime (CTX) on systemic infections induced by Escherichia coli Ec-31, Staphylococcus aureus SMITH, and Serratia marcescens Sm-6 in mice. Against systemic infection with Pseudomonas aeruginosa HR 810 was as effective as CAZ. Mice with leukopenia induced by cyclophosphamide were systemically infected with methicillin-resistant S. aureus (MRSA), methicillin-susceptible S. aureus (MSSA), Enterobacter cloacae, Acinetobacter calcoaceticus, and Enterococcus faecalis. HR 810 was superior to cefuzonam (CZON) and cefmetazole against MRSA and MSSA and was much more active than any other antibiotics tested against E. cloacae and A. calcoaceticus. In the activity against E. faecalis, HR 810 was inferior to ampicillin but superior to CZON. In mice with pyelonephritis caused by E. coli Ec-7, the rank order of activities was HR 810 greater than CAZ greater than CTX greater than CPZ. HR 810 was more effective than latamoxef, CAZ, CTX, and CPZ in improving lung infections induced by Streptococcus pneumoniae HL 438 and Klebsiella pneumoniae Kp-51 in mice. HR 810 was superior to CTX and CPZ and comparable to cefazolin in therapeutic effects on intrauterine infections with E. coli Ec-89 and S. aureus SMITH in rats.

Animals↗
PubMed1990

[Left ventricular aneurysmectomy after myocardial infarction--comparative study between true aneurysms and functional aneurysms].

Postinfarction left ventricular aneurysms are pathophysiologically divided into true, functional and false aneurysm. On 14 patients treated by aneurysmectomy, we studied the difference of pre- and post-operative cardiac function between true aneurysms (9 patients) and functional aneurysms (5 patients). The aneurysm area, which is expressed as the end-diastolic perimeter (akinetic or dyskinetic area/left ventricular silhouette), was 51.6 +/- 7.7% in the true aneurysms versus 35.7 +/- 6.0% in the functional aneurysms. Preoperatively, patients with a true aneurysm had a more severe clinical status than those with a functional aneurysm (Six of nine patients with a true aneurysm were in New York Heart Association functional class III or IV). Postoperatively, all patients except one with a true aneurysm and one with a functional aneurysm improved in clinical status. Nonaneurysmal EF, that is the function of the nonaneurysmal left ventricle, has a significant correlation to postoperative LVEF (r = 0.57, p less than 0.05). Nonaneurysmal EF was 54 +/- 4% in the true aneurysm group versus 51 +/- 16% in the functional aneurysm group. LVEF improved significantly (p less than 0.05) from 31 +/- 11% preoperatively to 55 +/- 10% postoperatively in the group of true aneurysm, but did not improved significantly from 43 +/- 12% to 50 +/- 9% in the functional aneurysm group. The postoperative akinetic area was 8.1 +/- 9.1% in the true aneurysm group versus 17.8 +/- 11.5% in the functional group. We conclude that larger and more adequate resection of aneurysms improves the cardiac function in the true aneurysm group more than in the functional aneurysm group.

Adult↗
PubMed1990

[The effects of pulsatile pumping on tissue perfusion and renal function during deep hypothermic low flow perfusion].

The effects of pulsatile pumping on tissue perfusion and renal function during deep hypothermic low flow perfusion were compared with non-pulsatile pumping. Twelve dogs were classified into 2 groups by the perfusion technique used. Animals were core cooled to 20 degrees C esophageal temperature with 80 ml/kg/min perfusion rate and maintained at the level for 2 hours with low flow perfusion (LFP) (30 ml/kg/min), then rewarmed to 35 degrees C with 80 ml/kg/min flow rate. As compared with the non-pulsatile group, pulsatile group demonstrated greater urine output during rewarming (p less than 0.05) and greater lymph flow during core cooling (p less than 0.05). The non-pulsatile group showed higher lymph/plasma protein concentration ratio (Lc/Pc) during LFP and rewarming (p less than 0.05), and greater plasma protein clearance during rewarming (p less than 0.05), and much higher increase of interstitial fluid pressure. The lesser water retention during bypass was also noted in the pulsatile group (28.6 +/- 27.6 ml/kg vs 85.4 +/- 52.1 ml/kg, p less than 0.05). These findings have suggested that the pulsatile perfusion may be useful for the infant cardiopulmonary bypass reducing tissue edema and preserving better renal function.

Animals↗
PubMed1990

[A case of aortitis syndrome with left coronary ostial stenosis and aortic regurgitation treated by transaortic coronary endarterectomy and aortic valve replacement].

A case, 23-year-old female of aortitis syndrome with left coronary ostial stenosis and aortic regurgitation was reported. The coronary angiography showed critical stenosis of the left coronary ostium with intact main stem and its branches. The aortogram revealed aortic regurgitation of grade III, and multiple obstructive or stenotic lesions on the left common carotid artery, the origin of the left renal artery, the inferior mesenteric artery and the abdominal aorta. After improvement of inflammatory findings by steroid therapy during 2 months, transaortic coronary endarterectomy and aortic valve replacement with 21 mm Björk-Shiley valve were performed successfully. Postoperative course was uneventful. Coronary angiography performed at the 57th day after the operation showed complete removal of the left coronary ostial stenosis, and aortography showed no evidence of perivalvular leakage of the aortic valve prosthesis. The indication of transaortic coronary endarterectomy and the technique used to avoid aortic valve detachment which may be caused by recurrence of aortitis were discussed in this paper.

Adult↗
PubMed1990

[Pharmacokinetics and clinical studies on aztreonam in neonates].

Pharmacokinetic and clinical studies on aztreonam (AZT) were performed in neonates. Serum concentrations and urinary excretion of AZT were determined in 12 neonates with ages between 0 and 7 days (birth weights were between 1,260 and 3,500 g) upon intravenous injection or 1 hour drip intravenous infusion of AZT at 20 mg/kg. Serum concentrations of AZT at 1 hour after i.v. administration were 54.0 +/- 12.5 micrograms/ml, and half-lives were 6.01 +/- 0.70 hours. Serum concentrations of AZT reached their peaks at the end of drip infusion with levels of 42.1 +/- 17.6 micrograms/ml in the d.i.v. group and half-lives were 6.40 +/- 1.88 hours. Urinary recovery rates in the first 12 hours after administration were 28.5 +/- 6.4% for the i.v. group and 32.3 +/- 13.9% for the d.i.v. group. AZT was administered to 12 neonatal patients (2 cases of sepsis, 2 cases of suspected sepsis, 3 cases of pneumonia, 2 cases of urinary tract infection and 3 cases for prophylaxis), and clinical effectiveness, bacteriological efficacy and adverse reactions were evaluated. Clinical efficacies in 9 cases except 3 cases with prophylactic use were excellent in 1 case, good in 5 cases, fair in 1 case, poor in 1 case and unknown in 1 case, thus the efficacy rate was 75%. Bacteriological effects in 3 strains with Gram-negative bacilli were eradicated in 2 strains and unchanged in 1 strain, hence the bacteriological eradication rate was 66.7%. Increased GOT and GPT were observed in 1 cases as abnormal laboratory test results, but the abnormality was not serious.(ABSTRACT TRUNCATED AT 250 WORDS)

Aztreonam↗