Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 307 records · Page 17Linked to original sources

PubMed1990

[Elective prosthetic valve reoperation to relieve unacceptably high gradient].

Pressure gradients of Lillehei-Kaster valve (13 patients), Omniscience valve (26 patients) and Omnicarbon valve (7 patients) in the aortic position were evaluated by Doppler echocardiography. Twenty-three out of 46 patients revealed unacceptably high gradients. Seven prostheses were removed because the valve design that they had high gradients across them. Clinical findings including left ventricular function and symptoms improved after the reoperation. Patients who underwent aortic valve replacement with this series of valve prostheses should be followed up cautiously.

Aortic Valve↗

PubMed1990

[A case of quadricuspid aortic valve with aortic regurgitation].

A 67-year-old man with grade 3 aortic valve regurgitation was found to have a quadricuspid aortic valve. The aortic valve consisted of 1 large, 2 intermediate and 1 small sized cusp. An accessory cusp located between the right and noncoronary cusps, and shaped like a hammock which sling by the fibrous strings originating from the both commissures to the aortic wall. Aortic valve replacement was successfully performed with a 23 mm St. Jude Medical prosthetic valve, and the patient is asymptomatic five months post-operatively. Histological examination of the resected cusps showed fibrous thickening and no rheumatic valvulitis or infective endocarditis.

Aged↗

PubMed1989

An ice nucleation active gene of Erwinia ananas. Sequence similarity to those of Pseudomonas species and regions required for ice nucleation activity.

The ice nucleation active gene, inaA, of Erwinia ananas IN-10 has been sequenced. This gene encodes a protein composed of 1322 amino acid residues. The inaA protein contains a 1120-residue segment consisting of 70 repeats of closely related 16 amino acid motifs (R-domain), which is flanked by N- and C-terminal sequences (N- and C-domains, respectively). Its primary structure is similar to, but not identical with, those of Pseudomonas inaW and inaZ gene products. By truncating the inaA gene to various extents, it was found that deletion of the C-domain resulted in complete loss of the ice nucleation activity, whereas removal of the N-domain led to a moderate decrease in the activity. Complete loss of the activity was also observed when the N-domain plus a large part of the P-domain were deleted. It is suggested that the C-domain is required for the assembly of inaA protein to form a functional ice nucleus.

Amino Acid Sequence↗

PubMed1989

Cloning and sequence analysis of the genomic DNA fragment encoding oryzacystatin.

A genomic DNA clone encoding oryzacystatin (Oc), a cysteine proteinase inhibitor (cystatin) of rice, was isolated from a lambda EMBL3 phage library constructed with Sau3AI partial digests of rice chromosomal DNA, by screening with an oc cDNA as a probe. The restriction map of the isolated DNA fragment was consistent with the pattern of the genomic Southern-blot analysis using a cDNA probe, and consequently, the gene is considered to be a single-copy gene. The oc gene is about 1.4 kb long and composed of three exons and two introns. The first intron (336 bp) intervenes between Ala-38 and Asp-39. The second intron (372 bp) exists in the 3'-noncoding region at the G residue next to the stop codon. S1 nuclease mapping showed the major transcription start point (tsp) at A, 104 bp upstream from the start codon (ATG). Typical CAT and TATA box sequences were found in the 5'-upstream region of the tsp. The nucleotide sequences around the TATA box, the tsp, the start codon, and the stop codon essentially matched the consensus sequences of other higher plant genes. The intron boundaries of the oc gene were quite different from those of the human kininogen-encoding gene and the human salivary cystatin (cystatin S)-encoding gene.

Amino Acid Sequence↗

PubMed1989

An immunohistochemical study on the innervation of SP-IR nerves in the cerebral arteries of the bent-winged bat.

The overall distribution of substance P (SP) immunoreactive (IR) nerves surrounding the cerebral arteries of the bent-winged bat were investigated immunohistochemically. In this microchiropteran species, the walls from the vertebral artery to the caudal part of the basilar artery have considerably well-developed plexuses of SP-IR nerves, whereas no demonstrable SP-IR fibers were found in the rostral part of the basilar artery, and in more rostrally located arteries the nerve supply was very sparse or occasionally lacking. This innervation pattern has not yet been established for the cerebral arterial systems of other mammals that have been studied under normal conditions, but it is very similar to the pattern of SP-IR innervation observed in the guinea pig and cat of which the trigeminal ganglia have been destroyed. From the combination of this and other immunohistochemical findings, it is suggested that SP-IR nerves innervating the vertebral and basilar arteries of the bent-winged bat originate from the upper cervical dorsal root ganglia (DRG) and enter the cranial cavity along the vertebral artery and through the meninges.

Animals↗

PubMed1989

Suppressive effect of interferon-beta-activated natural killer cells on lipopolysaccharide-induced B cell differentiation of MRL/Mp-lpr/lpr mice.

The suppressive effects of mouse recombinant interferon-beta (IFN-beta) on B cell differentiation of MRL/Mp-lpr/lpr (MRL/1) mouse, a model of autoimmune diseases, and C3H/H2 mice, a normal situation, were investigated. Spleen mononuclear cells were cultured in the presence of lipopolysaccharide (LPS), and the suppressive effect of IFN-beta was examined on differentiation of B cells to plaque-forming cells (PFCs) by highly sensitive reversed hemolytic plaque assay. IFN-beta (5,000-10,000 units/ml) suppressed more than 50% of PFCs of both MRL/1 and C3H/H2 mice. This suppressive activity as well as the cytotoxicity of natural killer (NK) cells enhanced by IFN-beta was abrogated by treatment of the spleen cells with anti-asialo GM1 antibody in the presence of complement. This suppressive activity was also abrogated by intravenous administration of 20 microliter/mouse of anti-asialo GM1 12 hr before cultivation of spleen cells. These results suggest that NK cells activated by IFN might be responsible for the immunoregulation in autoimmune diseases.

Animals↗

PubMed1989

In vitro effects of beta-lactams combined with beta-lactamase inhibitors against methicillin-resistant Staphylococcus aureus.

The effects of combinations of beta-lactams with two beta-lactamase inhibitors, sulbactam and clavulanic acid, were determined in vitro against 22 clinical isolates of methicillin-resistant Staphylococcus aureus. Combinations of cefpirome, cefotaxime, and cefazolin with sulbactam (10 micrograms/ml) showed synergistic effects against more than 70% of the strains. Combinations of methicillin and penicillin G with sulbactam also showed synergistic effects against 50 and 68% of the strains, respectively, while cefotiam, moxalactam, flomoxef, and cefmetazole in combination with sulbactam showed such effects against only 40% or fewer. Clavulanic acid was synergistic only when combined with penicillin G, the effect probably being due to the beta-lactamase inhibition by the inhibitor. Sulbactam did not improve the antimicrobial activities of the beta-lactams against methicillin-susceptible S. aureus strains. At 42 degrees C the MICs of cefotaxime, methicillin, and flomoxef alone were markedly decreased from the values at 35 degrees C, and no synergy between these beta-lactams and sulbactam appeared. The resistance to penicillin G was not inhibited by incubation at 42 degrees C, and combinations of penicillin G with sulbactam and clavulanic acid showed synergy. The amounts of beta-lactamase produced were not related to the decreases in the MICs of the beta-lactams, except for penicillin G combined with sulbactam. Clavulanic acid showed slightly stronger beta-lactamase-inhibiting activity than sulbactam did. These results suggest that the synergy between sulbactam and the beta-lactams, except for penicillin G, may not be due to beta-lactamase inhibition but to suppression of the methicillin-resistant S. aureus-specific resistance based on other factors.

Anti-Bacterial Agents↗

PubMed1989

Ocular pharmacokinetics of latamoxef and cefaclor in humans. Penetration into aqueous humor.

Penetrations of latamoxef (LMOX) and cefaclor (CCL) into the aqueous humor after intravenous or oral administration were investigated in patients admitted with cataract. Concentrations of antibiotics in plasma and aqueous humor were determined periodically by microbiological assay. LMOX disappeared from plasma in a monoexponential manner with a half-life of 2.7 h after intravenous administration at a dose of 1000 mg. The maximum concentration of LMOX in aqueous humor (4.7 micrograms/ml) was observed 2 h after administration. When CCL was administered orally at a dose of 500 mg, the maximum concentration of CCL in aqueous humor was 0.53 microgram/ml 2 h after administration, whereas the maximum plasma concentration of 8.4 micrograms/ml was observed at 1 h. Pharmacokinetic analysis (simultaneous simulation) of plasma and aqueous humor concentration-time courses was done by using the best-fitting compartment model examined (modified two-compartment model). Prediction of the concentration of antibiotics in aqueous humor from the plasma concentration profile was also examined using the same compartment model in a separate experiment. The predicted concentration in aqueous humor was proved to fit reasonably with the measured concentration.

Aged↗

PubMed1989

[Clinical effects of chewing gum containing egg-white lysozyme and mace extract].

The purpose of this study was to evaluate the clinical effect of mace extract and egg-white lysozyme in two brands of chewing gum on gingival condition. Ever since mace extract containing dihydroguaiaretic acid was reported to inhibit the growth of Streptococcus mutans, plans were devised to include it in commercially available chewing gum. Before starting this study, two different types of experimental chewing gum containing mace extract or egg-white lysozyme were made up. A control was also prepared containing neither agent. The periodontal condition of 68 patients with gingivitis was determined based on PMA index (PMA), gingival index (GI), gingival bleeding index (GBI) and plaque scoring system (PSS) and randomly classified into three groups. Each group was instructed to use one or the other of the above type chewing gums after every meal. The results were as follows: 1. No clinical changes were observed in the control group during this study. 2. Gingival inflammation (PMA, GI, GBI) significantly improved as a result of using the experimental gums. 3. Plaque reduction was found only in the mece-extract gum group. 4. No clinical side effects were detected during this study.

Chewing Gum↗

PubMed1989

Scanning electron microscopic study on the lingual papillae of the Japanese insectivora.

The tongue and lingual papillae of the Japanese Insectivora, the Shinto shrew (Sorex caecuiens saevus), the long-clawed shrew (S. unguiculatus), the dsinezumi shrew (Crocidura dsinezumi dsinezumi) and the Japanese water shrew (Chimarrogale himalyica platycephala), were observed by scanning electron microscope. The tongue of these animals had two vallate papillae. In two species of the Sorex a papilla in the vallate papilla was surrounded by two separated trenches, but in the other species it was surrounded by only a continuous trench and a clear vallum. The fungiform papillae in the Sorex were less developed than those of the other species. In the Sorex and Crocidura, there was no filiform papilla on the lingual apex. These genera, however, have papillary projections in the margin of the lingual apex. The results of this investigation suggest that the Sorex and Crocidura indicate an ancient form of the mammalian tongue. These characters, furthermore, were compared among seven species in six genera added three species observed by Kobayashi et al. (1983) to this study.

Animals↗

PubMed1989

The distinct subgroup of patients with rheumatoid arthritis shown by Ig G3-reactive rheumatoid factor.

The reactivity of rheumatoid factor (RF) with immunoglobulins of the IgG3 subclass was examined in 49 patients with rheumatoid arthritis (RA) using two types of IgG3 myeloma (routine and IgG3m-15 allotype). Among 49 patients, serum from eight cases showed positive reactivity with both types of IgG3 myeloma by radio-immunoassay (RIA). The isotype of IgG3-reactive RF was not specific; it belonged to the IgM class as well as the IgG subclasses IgG1, IgG2 and IgG4. The patients with IgG3-reactive RF belonged to the clinically-severe classification of RA, having a high erythrocyte sedimentation rate (ESR), high titre in the RA hemagglutination (RAHA) test, and above all they had low levels of complement. Generally, it is concluded that patients with IgG3-reactive RF have serious arthritis and that IgG3-reactive RF might play an important role in the inflammatory process. Furthermore, it was also shown that the RF-reactive site was not associated with the protein-A binding site of IgG3, since RF reacting with IgG3m-15 reacted similarly with routine IgG3, regardless of the difference of the protein-A binding activity. This was confirmed by adding protein-A to the reaction of RF and IgG3m-15 which binds with protein-A. This suggests that the actual reactive site of RF is different to the site that binds protein-A.

Adult↗

PubMed1989

[Induction by mycoplasmas of tumor necrosis factor-alpha from macrophages].

Several species of mycoplasmas including M. pneumoniae, the causative agent of human respiratory infection, were investigated for tumor necrosis factor-alpha (TNF-alpha) induction. The cytotoxic activity to Meth A cells of peritoneal macrophages purified from BALB/c mice was enhanced markedly when cultured with either viable or nonviable mycoplasmas. The supernatant of macrophage culture mixed with mycoplasmas, M. pneumoniae or A. laidlawii, showed a potent cytotoxic activity to TNF-alpha-sensitive but not to TNA-alpha-insensitive L cells. Addition of anti-TNA-alpha antiserum inhibited completely the cytotoxic activity of the supernatant, indicating that the cytotoxic activity is due mostly to TNF-alpha. These results strongly suggest that mycoplasmas possess an activity to induce TNF-alpha, which enhances the cytotoxic activity of macrophages and prevent infection with mycoplasmas in vivo.

Animals↗

PubMed1989

[Oral health condition of the population in special elderly nursing home].

With the objective of making clear the oral health condition of chronic disable elderlies and thereby obtaining information for oral hygiene education and dental treatment, 77 elderlies in a special elderly nursing home attached to a private general hospital in Niigata Prefecture were studied by an interview/questionnaire method and dental examination. The following results were obtained. (1) Their mean age was 82.0 years. The major causes of chronic disability were diseases of the cerebral blood vessel and these diseases accounted for 54.5% of all diseases. The mean period of their chronic disability was 9 years. (2) 49.4% (38 persons) of them was edentulous, and 47.9% (18 persons) of them was using complete denture. (3) The average number of present teeth was 4.6 in all persons, while it was 9.0 in dentulous persons, and 3.3 of which were residual roots. (4) Salivary occult blood reaction test was positive in 87.2% in the dentulous persons and 34.2% in edentulous persons. (5) Simplified culture test using STOMASTAT was negative in 48.4% and positive in 51.6% of persons using a denture. (6) The above results indicated that dental diseases of chronic disable elderlies are not treated appropriately. This study revealed importance of dental examination, oral hygiene education and initial treatment in middle-aged and older persons.

Aged↗

PubMed1989

[Experience of fluconazole in pediatric patients].

Fluconazole is a triazole agent and possesses a potent antifungal activity against fungi such as Candida, Cryptococcus and Aspergillus. Fluconazole is well absorbed following oral administration and shows bioavailability almost comparable to that attained in intravenous administration. The serum half-life is as long as about 30 hours and distributed widely into organs and tissues. Because of these it is expected to exhibit good clinical efficacy in the deep-seated mycosis. We evaluated the efficacy of fluconazole given orally to 3 pediatric patients with deep mycosis and also with aim of evaluating its prophylactic effect, gave fluconazole to 4 patients who had high risks of mycotic infections. Pathogenic fungi isolated from the 3 patients with mycosis were all Candida albicans and diagnoses made were Candida pneumonia, oral candidiasis and gastrointestinal candidiasis. Clinical efficacies were judged to be good in all of the 3 patients and C. albicans were found eradicated following the treatment. In the 4 patients to whom fluconazole was given prophylactically, no mycosis developed. Fluconazole was well tolerated and no incidence of side effects or clinical laboratory parameter abnormalities were seen any of the patients involved in the study.

Administration, Oral↗

PubMed1989

Effect of paraquat on serum and lung angiotensin I converting enzyme (AICE) activity in beagle dogs.

The purpose of this study was to examine the relationship between lung or serum angiotensin I converting enzyme (AICE) activity and lung damage due to the administration of paraquat (PQ) which develops into PQ toxicity. Our experimental animals consisted of 19 beagle dogs (1-1.5 years old) that were allocated, randomly, into 2 treatment group, consisting of 11 PQ-treated animals and a control group of 8 saline-treated animals. These canines were administered PQ dichloride sc at a dose of 1.0 mg/kg body weight (PQ group) or sc saline at a dose of 0.5 ml/kg body weight (control group) for 7 to 11 consecutive days; these are doses which had been shown to be toxic to lungs. If a decrease in the animal's body weight was detected, the administration of PQ to that dog was discontinued. Body weight loss was observed in 10 of the 11 dogs treated with PQ. Representative dogs were sacrificed on days 11, 25 and 180 for the determination of both serum and lung AICE activity. The PQ group experienced a reduction in lung AICE activity and an elevation in the serum AICE activity. These results suggest that PQ damaged the endothelial cells of the lung and releasing lung AICE into the circulating blood, which led to an elevated total AICE activity in the serum. This pattern suggested damage to endothelial cells, indicating that PQ produced either continuing or repeated reinjury to lungs. Only the lungs were injured; therefore AICE from the rest of the body would not be expected to contribute to our AICE measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1989

[Experimental study of materials used for intra-atrial baffle for the Mustard operation].

An experimental model was developed to study the fate of prosthetic materials used for the construction of an intra-atrial baffle for the Mustard operation. Total atrial septa were replaced in sixteen puppies with autologous pericardium (n = 3), glutaraldehyde-preserved canine pericardium (n = 4), glutaraldehyde-preserved porcine pericardium (n = 3), EPTFE reinforced sheet (Gore-Tex sheet, n = 3) and EPTFE reinforced cardiovascular patch (Gore-Tex patch, n = 3). Septal replacement was performed under total circulatory arrest and surface induced deep hypothermia. All animals were sacrificed six months after the septal replacement. Pathological examination revealed that all septal grafts were well healed, completely covered by neoendothelium and had contracted to approximately 60% of their original size. There were no significant difference between groups. Histologic examination showed the good tissue adaptation of autologous pericardium and Gore-Tex patch materials. The thinnest layers of neoendothelium covered autologous pericardial baffle. Glutaraldehyde-preserved pericardium and Gore-Tex sheet did not adapt well to host atrial tissue. These materials were easily detached from their neoendothelial substrates. It was concluded that the autologous pericardium as well as a Gore-Tex patch may be superior to other prosthetic materials used for the construction of an intra-atrial baffle for the correction of transposition of the great arteries.

Animals↗

PubMed1989

Experimental autoimmune uveoretinitis (EAU) in rats: isolation of S-antigen, EAU susceptibility of rat strains, genetic control of EAU induction, and effects of cyclophosphamide and irradiation on EAU.

Highly purified S-antigen was isolated from bovine retinas by high performance liquid chromatography (HPLC), and was used to induce experimental autoimmune uveoretinitis (EAU) in various rat strains. Studies were then made of the genetic control of EAU, the effects of cyclophosphamide or irradiation on EAU, and the correlation between the EAU incidence and the serum levels of antibody to S-antigen. Lewis rats were the most susceptible to EAU followed by Wistar rats. F344 rats and BN rats were resistant to EAU. (Lewis X BN)F1 rats and (LBNF1 X Lewis) rats were susceptible to EAU, while (LBNF1 X BN) rats were resistant. These results indicate that susceptibility to EAU was inherited as an autosomal dominant trait. Treatment of rats with cyclophosphamide or irradiation (200 rad/rat) on the day before immunization markedly suppressed EAU development. On the other hand, the same dose of irradiation 7 days after the immunization did not affect the disease induction, yet the antibody levels to S-antigen were very high in the rats. In addition, BN rats resistant to EAU exhibited very high levels of antibody to S-antigen. Therefore, the antibody to S-antigen seems to play a minor role, if any, in the immunopathogenic mechanisms of EAU.

Animals↗

PubMed1989

[Variant angina due to deficiency of intracellular magnesium by anorexia nervosa].

A 51-year-old man who had a past history of gastric resection for medically uncontrollable gastric ulcer has loss of appetite that recurs periodically. And he has frequently presented spontaneous angina early in the morning since 1984. He was diagnosed as having variant angina by the documentation of typical ST elevation during anginal attack and also by showing coronary artery spasm (#2 and #12) during hyperventilation on coronary arteriography. A large quantity of calcium blocking agents and nitrates could not improve his symptoms. Lack of intracellular magnesium by loss of appetite was suspected from a daily excretion of urine magnesium (5.3 mEq) and magnesium tolerance test (56.7%). To confirm the effect of magnesium administration, the second coronary arteriography was performed. After magnesium sulphate (80 mEq, hourly) was injected, coronary artery spasm could not be induced by ergonovine. And orally magnesium oxide, calcium blocking agents and nitrates were started. Anginal attack disappeared with increasing urine magnesium.

Angina Pectoris, Variant↗