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Biomedical subjects

M Arai

Publications and source records attributed to M Arai.

At least 451 records · Page 25Linked to original sources
PubMed1992

[Platelet aggregations and glycoproteins].

Platelet membrane glycoproteins play important roles in platelet functions. In this symposium, we reported three types of deficiency of platelet membrane glycoproteins; Glanzmann's thrombasthenia, Bernard-Soulier syndrome, GPIV-deficiency and discussed the roles of GPIIb/IIIa, GPIb and GPIV, respectively, in the aggregation of these abnormal platelets. In a patient with Bernard-Soulier syndrome, the abnormality in the patient's GPIb was caused by the double heterozygote from her parents who were unrelated. Roles of GPIV were negligible in platelet aggregation since the GPIV-deficient platelets (Naka-) found in healthy donors showed normal platelet aggregations. We developed two monoclonal antibodies, TM83 and TM60 against GPIIIa and GPIb, respectively, and showed that these antibodies inhibited the function of GPIb and GPIIb/IIIa complex, respectively. We demonstrated that TM83 inhibited an epitope of GPIIIa and/or GPIIb/IIIa complex which changes its conformation due to Ca2+ deprivation and is essential for exposure of the fibrinogen-binding site.

Adult↗
PubMed1992

The efficacy of additive use of etizolam in patients with essential hypertension and unspecified complaints.

The relationship between hypertension and emotional depression or anxiety has been long-argued. We assessed the efficacy of etizolam (an antianxiety drug) in 18 patients with essential hypertension accompanied with unspecified complaints. In the assessment of overall improvement, 4 patients (22.2%) were rated as markedly improved, 4 patients (22.2%) as moderately improved, 7 patients (38.9%) as slightly improved, 3 patients (16.7%) as unchanged, and none as worsened. Systolic and diastolic pressure decreased significantly in 13 patients (72.2%) and 10 patients (55.5%), respectively. Many subjective symptoms such as anxiety, fatigue and depression improved. No significant adverse reaction from drug was observed. These results allow us to conclude that etizolam is effective and safe for the treatment of essential hypertension accompanied with unspecified complaints.

Administration, Oral↗
PubMed1992

[Phase II study of 254-S (cis-diammine glycolato platinum) for gynecological cancer].

A phase II study of 254-S was conducted in 134 patients with gynecological malignancies by the gynecology section of the 254-S cooperative study group. The drug was administered at least twice at a dose of 100 mg/m2 by intravenous infusion at 4 week intervals. Forty-two of the 102 evaluable patients responded, including 8 CRs and 34 PRs, with a response rate of 41.2%. The response rate was 37.7% for ovarian cancer and 46.3% for cervical cancer. The response rate of 46.3% for cervical cancer was the highest reported for any single anticancer agent available in Japan. The major side effect was hematotoxicity, in particular thrombocytopenia and leukopenia, while nephrotoxicity was rarely observed. These results suggest that 254-S is an active cisplatin analogue with reduced nephrotoxicity and is a very promising anticancer agent for the treatment of ovarian and cervical cancer.

Adult↗
PubMed1992

[A case of chronic progressive external ophthalmoplegia associated with familial hypercholesterolemia].

A 52-year-old woman with chronic progressive external ophthalmoplegia (CPEO) with familial hypercholesterolemia (FH) was reported. Her mother died from heart disease, and her elder sister has hypercholesterolemia with swelling of Achilles tendons. She had slowly progressive external ophthalmoplegia, bilateral ptosis, swelling of Achilles tendons since twenties. At 40 years of age, she was pointed out hypercholesterolemia. Physical examination was within normal limits except for bilateral swelling of Achilles tendons. Neurological findings showed bilateral ptosis, disturbance of eye movements, mild proximal muscle weakness and dysesthesia in bilateral hands. Routine laboratory findings were within normal limits except for high serum cholesterol level (512 mg/dl). In the biopsied muscle, there was mild variation in fiber size with several ragged-red fibers and focal cytochrome c oxidase defective fibers. Biochemical analysis of the biopsied muscle revealed normal values in the mitochondrial fraction. Southern blot analysis of the mitochondrial DNA (mtDNA) of the muscle disclosed mixed population of mtDNA, consisting of the normal one and partially deleted (4.9-kilobase). Southern blot analysis of the leukocytes from the patient against the cDNA of LDL receptor was normal at least using the restriction enzyme of BglII, XbaI, EcoRI, PvuII and BamHI. This case has CPEO with deleted mtDNA associated with familial hypercholesterolemia, which is caused to nuclear DNA abnormalities, and is thought to be an important case for us to study the relationship between deleted mtDNA and abnormal nuclear DNA in CPEO.

Chromosome Deletion↗
PubMed1992

[Multicenter clinical evaluation of red cell concentrates stored up to 6 weeks in MAP, a new additive solution].

The clinical safety and efficacy of transfusion of red cell concentrates stored in MAP solution (MAP-CRC) containing mannitol, adenine, glucose, phosphate and citrate, into 39 anemic patients were evaluated. In 23 patients, infusion of MAP-CRC was alternated with infusion of ordinary CRC as a control. The MAP-CRC and CRC used in this study were stored at 4 degrees C for an average of 38.2 +/- 2.6 days (n = 52) and 18.1 +/- 2.2 days (n = 26), respectively. Red cell recovery was 77.5% for MAP-CRC and 82.5% for CRC, based on calculation of the increase in hemoglobin level one day after transfusion. There were no differences between patients transfused with MAP-CRC and those transfused with CRC in clinical findings or biochemical data. No major side-effects other than pyrexia associated with the underlying infections were seen in patients transfused with MAP-CRC. MAP-CRC stored up to 42 days is apparently as safe and effective as stored CRC. This new additive solution may therefore be useful for the future expansion of the indications for autologous blood transfusion by facilitating the collection and storage of more blood in the liquid state for a longer period, and may also be useful in obtaining more plasma from whole blood as source plasma.

Adenine↗
PubMed1991

Synthesis of a 3-ether analogue of lipid A.

Lipid A 3-ether analogues were synthesized from allyl 2-deoxy-4,6-O-isopropylidene-2-trifluoroacetamido-alpha-D-glucopyr anoside and 3,4,6-tri-O-acetyl-2-trifluoroacetamido-alpha-D-glucopyranosyl bromide. The compound lost completely the endotoxic activity.

Animals↗
PubMed1991

Cloning and characterization of the gene encoding rabbit cardiac calsequestrin.

A cDNA encoding rabbit cardiac calsequestrin was isolated and characterized. The deduced nascent cardiac calsequestrin contains 409 amino acids of which 26% are acidic residues, and had 93% and 67% aa identity with canine cardiac calsequestrin and rabbit fast-twitch skeletal muscle calsequestrin, respectively. RNA blot analyses indicate that this mRNA is expressed in atrium, ventricle and to a lesser amount in slow-twitch skeletal muscle. This mRNA transcript is not expressed in adult fast-twitch skeletal muscle, smooth muscle, or nonmuscle tissues. Analysis of in vitro skeletal muscle myogenesis using a mouse myoblast cell line C2C12, demonstrates that both cardiac and skeletal calsequestrin isoforms are coproduced during muscle differentiation.

Actins↗
PubMed1991

Molecular characterization of mild-to-moderate hemophilia A: detection of the mutation in 25 of 29 patients by denaturing gradient gel electrophoresis.

To date it has been difficult to characterize completely a genetic disorder, such as hemophilia A, in which the involved gene is large and unrelated affected individuals have different mutations, most of which are point mutations. Toward this end, we analyzed the DNA of 29 patients with mild-to-moderate hemophilia A in which the causative mutation is likely to be a missense mutation. Using computer analysis, we determined the melting properties of factor VIII gene sequences to design primer sets for PCR amplification and subsequent denaturing gradient gel electrophoresis (DGGE). A total of 45 primer sets was chosen to amplify 99% of the coding region of the gene and 41 of 50 splice junctions. To facilitate detection of point mutations, we mixed DNA from two male patients, and both homoduplexes and heteroduplexes were analyzed. With these 45 primer sets, 26 DNAs containing previously identified point mutations in the factor VIII gene were studied, and all 26 mutations were easily distinguishable from normal. After analyzing the 29 patients with unknown mutations, we identified the disease-producing mutation in 25 (86%). Two polymorphisms and two rare normal variants were also found. Therefore, DGGE after computer analysis is a powerful method for nearly complete characterization of disease-producing mutations and polymorphisms in large genes such as that for factor VIII.

Base Sequence↗
PubMed1991

Immunohistochemical localization of calretinin in the rat hindbrain.

The localization of calretinin in the rat hindbrain was examined immunohistochemically with antiserum against calretinin purified from the guinea pig brain. Calretinin immunoreactivity was found within neuronal elements. The distribution of calretinin-immunoreactive cell bodies and fibers is presented in schematic drawings and summarized in a table. Major calretinin-immunoreactive neurons were found in the lateral and medial geniculate nuclei, substantia nigra, ventral tegmental area, interpeduncular nucleus, periaqueductal gray, mesencephalic trigeminal nucleus, superior and inferior colliculi, pontine nuclei, parabrachial nucleus, dorsal and laterodorsal tegmental nuclei, cochlear nuclei, vestibular nuclei, medullary reticular nuclei, nucleus of the solitary tract, area postrema, substantia gelatinosa of the spinal trigeminal nucleus, and cerebellum. These results show that distinct calretinin-immunoreactive neurons are widely distributed in the rat hindbrain.

Animals↗
PubMed1991

The complete amino acid sequence of ribonuclease from the seeds of bitter gourd (Momordica charantia).

The complete amino acid sequence of ribonuclease (RNase MC) from the seeds of bitter gourd (Momordica charantia) has been determined. This has been achieved by the sequence analysis of peptides derived by enzymatic digestion with trypsin, lysylendopeptidase, and chymotrypsin, as well as by chemical cleavage with cyanogen bromide. The protein contains 191 amino acid residues and has a calculated molecular mass of 21,259 Da. Comparison of this sequence with sequences of the fungal RNases, RNase T2, and RNase Rh, revealed that there are highly conserved residues at positions 32-38 (TXHGLWP) and 81-92 (FWXHEWXKHGTC). Furthermore, the sequence of RNase MC was found to be homologous to those of Nicotiana alata S-glycoproteins involved in self-incompatibility sharing 41% identical residues.

Amino Acid Sequence↗
PubMed1991

Administration of thyroxine in treated Graves' disease. Effects on the level of antibodies to thyroid-stimulating hormone receptors and on the risk of recurrence of hyperthyroidism.

BACKGROUND: Antibodies to thyroid-stimulating hormone (TSH) receptors that stimulate the thyroid gland cause hyperthyroidism in patients with Graves' disease, and their production during antithyroid drug treatment is an important determinant of the course of the disease. One factor that might contribute to the persistent production of antibodies to TSH receptors is stimulation of the release of thyroid antigens by TSH during antithyroid drug therapy. We therefore studied the effect of the suppression of TSH secretion by thyroxine on the levels of antibodies to TSH receptors after thyroid hormone secretion had been normalized by methimazole. METHODS AND RESULTS: The levels of antibodies to TSH receptors were measured during treatment with methimazole, either alone or in combination with thyroxine, in 109 patients with hyperthyroidism due to Graves' disease. The patients first received 30 mg of methimazole daily for six months. All were euthyroid after six months, and their mean (+/- SD) level of antibodies to TSH receptors decreased from 64 +/- 9 percent to 25 +/- 15 percent (P less than 0.01; normal, 2.9 +/- 1.4 percent). Sixty patients then received 100 micrograms of thyroxine and 10 mg of methimazole and 49 received placebo and 10 mg of methimazole daily for one year. In the thyroxine-treated group, the mean serum thyroxine concentration increased from 108 +/- 16 nmol per liter to 145 +/- 11 nmol per liter (P less than 0.01), and the level of antibodies to TSH receptors decreased from 28 +/- 10 percent to 10 +/- 3 percent after one month of combination therapy. In the patients who received placebo and methimazole, the mean serum thyroxine concentration decreased and the level of antibodies to TSH receptors did not change. Methimazole, but not thyroxine or placebo, was discontinued in each group 1 1/2 years after the beginning of treatment. The level of antibodies to TSH receptors further decreased (from 6.6 +/- 3.2 percent at the time methimazole was discontinued to 2.1 +/- 1.2 percent one year later) in the patients who continued to receive thyroxine, but it increased (from 9.1 +/- 4.8 percent to 17.3 +/- 5.8 percent during the same period) in the patients who received placebo. One patient in the thyroxine-treated group (1.7 percent) and 17 patients in the placebo group (34.7 percent) had recurrences of hyperthyroidism within three years after the discontinuation of methimazole. CONCLUSIONS: The administration of thyroxine during antithyroid drug treatment decreases both the production of antibodies to TSH receptors and the frequency of recurrence of hyperthyroidism.

Adolescent↗
PubMed1991

[Determination of the activity of urinary enzymes derived from renal tubulus].

There are several problems in measuring the activities of urinary enzymes, such as alkaline phosphatase (ALP), leucine aminopeptidase (LAP), and gamma-glutamyl transpeptidase (gamma-GTP) which are derived from renal tubulus. The purpose of the present study is to clarify the basic methodological problems in measuring these enzyme activities. Our results indicate that it is not necessary to dialyze urine when determining these three enzymes, except for alkaline phosphatase activity measured by the Kind-King method. Because of contamination of urine by bacteria and cell elements, the enzyme activity is influenced by centrifugal conditions that depend on time and speed. Our results propose that it is necessary, at least, to centrifuge at 3000 rpm for 10 minutes to obtain satisfactory data. Generally, a 24 hour urine sample instead of spot urine sample should be used for measuring the enzyme activity. However if correcting gamma-GTP activity by creatinine, even a spot urine sample may be used for clinical use.

Alkaline Phosphatase↗
PubMed1991

Modulation of the immune response to tumors by a novel synthetic compound, (4R)-3-benzoyl-N-[(1R)-1-phenylethyl]-4-thiazolidinecarboxamide (RS-0481).

RS-0481, (4R)-3-benzoyl-N-[(1R)-phenylethyl]-4-thiazolidinecarboxamide, is a compound that can re-establish the function of certain lymphoid cell populations impaired by the presence of a growing tumor in an animal. The compound markedly augmented the tumor-specific cytotoxic T lymphocytes, TDTH (delayed-type hypersensitivity T cells), and the nonspecific lymphokine-activated-killer-cell-like cell responses. It also enhanced the tumor-inhibitory effect of macrophages in tumor-bearing mice, but not in normal mice, indicating that it enhances the antitumor immune responses. Lymphocytes from RS-0481-treated tumor-bearing mice released significantly higher amounts of macrophage-activating factor(s) (MAF) and interleukin-2(IL-2)-like factors in culture compared with lymphocytes from untreated animals. Also, sera from treated tumor bearers showed elevated colony-stimulating factor (CSF) activity. Although the compound did not influence the factor-producing activity in mice without tumor, it enhanced the responsiveness of their bone marrow cells, T cells, and macrophages to CSF, IL-2, and MAF. It seems therefore possible that the compound enhances the responsiveness of immunocompetent cells to cytokines, resulting in a marked augmentation of antitumor T cell responses in tumor-bearing mice. Consistently it inhibited the development of lymph node metastasis of transplanted X5563 plasmacytoma, and we showed that T cells play a decisive role in this inhibition. The compound also counteracted the development of suppressor T cell activity in the spleen of tumor-bearing mice.

Adjuvants, Immunologic↗
PubMed1991

Effects of retinoic acid on bone formation and resorption in cultured mouse calvaria.

1. The effects of retinoids on bone metabolism were examined in newborn mouse calvaria. 2. Incubation of calvaria with 0.01-1 microM retinoic acid for 4 days decreased their alkaline phosphatase (ALP) activity, mineral content and collagen content in a concentration-dependent fashion. 3. With treatment for 2 days, retinoic acid (1 microM) decreased the ALP activity and collagen content, but not the mineral content. 4. All these inhibitory effects were observed in calvaria from 0-day-old mice, but no inhibition of ALP activity was observed in calvaria from 14-day-old mice. 5. 1-Hydroxyethylidene-1,1-bisphosphonate (HEBP, 1 mM), which inhibits bone resorption, prevented the effect of retinoic acid (1 microM) on the bone mineral content, but not the effects on ALP and collagen (synthesized by osteoblasts). HEBP (1 mM) alone had no effect on the calvarial mineral and collagen contents. 6. These findings indicate that retinoic acid both stimulates bone resorption and inhibits osteoblastic activity by different mechanisms, and that stimulation of bone resorption by retinoic acid is inhibited by HEBP.

Alkaline Phosphatase↗
PubMed1991

Synthesis of 2-deoxy-2-[(2,2-difluoro-3-hydroxytetradecanoyl)amino]-3-O- [(R)-3-(tetradecanoyloxy)tetradecanoyl]-D-glucopyranose 4-phosphate.

2-Deoxy-2-[(2,2-difluoro-3-hydroxytetradecanoyl)amino]-3-O-[(R)-3- (tetradecanoyloxy)tetradecanoyl]-D-glucopyranose 4-phosphates (9H,L) were synthesized from allyl 2-amino-2-deoxy-4,6-O- isopropylidene-beta-D-glucopyranoside (1), (+/-)-3-[(benzyloxycarbonyl)oxy]-2,2-difluorotetradecanoic acid, and (R)-3- (tetradecanoyloxy)tetradecanoic acid. Both compounds 9H and 9L were more active than GLA-60 for the prostaglandin D2 releasing test on macrophages.

Animals↗