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Biomedical subjects

M Maki

Publications and source records attributed to M Maki.

At least 145 records · Page 8Linked to original sources
PubMed1990

Increased expression of genes for basic fibroblast growth factor and transforming growth factor type beta 2 in human benign prostatic hyperplasia.

It is now widely accepted that factors other than androgen are crucial in the normal and abnormal growth of the prostate, including human benign prostatic hyperplasia (BPH). Using a Northern blot analysis, we examined human normal and benign hyperplastic prostates for expressions of basic fibroblast growth factor (FGF), acidic FGF, transforming growth factor type beta 2 (TGF-beta 2), TGF-beta 1, and epidermal growth factor (EGF). Basic FGF mRNAs were detectable in all the prostates examined. In addition, levels of basic FGF expression were significantly higher in BPH than in normal prostate. Acidic FGF transcripts were undetectable except in one case of BPH. Although both TGFs were expressed in all the samples, TGF-beta 2 showed significantly increased levels of expression in BPH as compared to those in normal prostate, while TGF-beta 1 did not. No EGF was expressed in any of the prostates examined. These findings suggest that specific growth factors (basic FGF and TGF-beta 2) produced locally in the prostate may be involved in BPH development.

Aged↗
PubMed1990

Enteral hyperalimentation as a source of nosocomial infection.

Microbial growth in enteral nutrition solutions (ENS) has frequently been documented. To determine the relation of this contamination to nosocomial infection, we prospectively studied 24 intensive care unit patients who received enteral feeding. Cultures of solutions were obtained while refrigerated and during administration as well as pharyngeal and rectal cultures from patients at the start of enteral nutrition and serially during administration. Most patients (10/16, 62.5%) receiving solutions mixed on the ward and 3/14 (21.4%) receiving solutions prepared elsewhere appeared to become colonized (0.05 less than P less than 0.10) by organisms initially isolated from feeds. By antibiotic susceptibility and plasmid analysis, eight patients were found to be colonized by 11 organisms identical to those which were first isolated from ENS. Two of these patients had ENS-associated pneumonias caused by Acinetobacter baumannii. Solutions often contained multiple Gram-negative bacilli similar to those recovered from nurses' hands and blenders, in numbers up to 1 x 10(8) ml-1. We conclude that ENS may be an important source of nosocomial infection. Uniform microbial criteria for ENS should be developed and methods to limit contamination should be utilized.

Adult↗
PubMed1990

Oncogenic transformation by the tax gene of human T-cell leukemia virus type I in vitro.

Human T-cell leukemia virus type I (HTLV-I) is a causative agent of adult T-cell leukemia (ATL). To elucidate the role of HTLV-I in leukemogenesis, we examined the biological activity of a defective HTLV-I provirus with the env-pX 3' long terminal repeat region cloned from leukemic cells of an ATL patient. Transfection experiments showed growth stimulation of NIH 3T3 cells--growing beyond the saturation density and growing in soft agar. Since the pX sequence is known to encode three proteins, Tax, Rex, and p21x, the biological activity of each pX gene was examined separately. The growth-stimulating activity was induced only by the tax gene in NIH 3T3 cells and Rat-1 cells. Furthermore, the tax gene induced tumorigenicity in nude mice when introduced into Rat-1 cells. Thus, a transcriptional transactivator gene of HTLV-I, tax, is clearly identified as a viral oncogene without a cellular homolog. The transforming activity of tax, possibly via a transcriptional deregulation of cell growth control, may play an important role in leukemogenesis of ATL in addition to its aberrant stimulation of the interleukin 2 system.

Animals↗
PubMed1990

2,3 Dimercapto-1-propanol inhibits HIV-1 tat activity, viral production, and infectivity in vitro.

We have examined the effect of 2,3 dimercapto-1-propanol (DMP), which is known as an anti-heavy metal-poisoning drug, against human immunodeficiency virus type 1 (HIV-1). We demonstrate that DMP inhibited transactivation directed by tat protein, which is a metal containing transcriptional transactivating factor and also interfered with viral production. Furthermore, treatment and pretreatment of cells with DMP strongly reduced their sensitivity for HIV-1 infection through unknown mechanisms. These results indicate that DMP reveals pleuripotent effects on HIV-1 infection and production in vitro and thus may provide an exploitable hypothesis for designing new drugs against AIDS.

Amino Acid Sequence↗
PubMed1990

Structure and properties of calphobindin II, an anticoagulant protein from human placenta.

The structure of human placental calphobindin-II (CPB-II) was investigated by amino acid composition and amino acid sequence analyses of peptides generated by protease digestion of the protein. The 45 peptides obtained from the lysyl endopeptidase digest of CPB-II, and the amino-terminal peptide prepared from its tryptic digest, were analyzed, and they accounted for over 98% of total amino acids of CPB-II. The structure of CPB-II determined by protein sequencing was identical to that previously predicted from its cDNA sequence (Iwasaki, A. et al. (1989) J. Biochem. 106, 43-49), except for the amino terminus. Since the amino terminus of CPB-II was blocked to Edman degradation, fast-atom-bombardment mass spectrometric analysis was used to demonstrate that the amino-terminal residue was acetyl-alanine. The carboxyl-terminal residue of CPB-II was identified as aspartic acid by the hydrazinolytic procedure. Calcium-binding studies indicated that 1 mol of CPB II binds 1 mol of calcium in the absence of phospholipid and 8 mol of calcium in the presence of phospholipid.

Amino Acid Sequence↗
PubMed1990

The third nationwide survey in Japan of vitamin K deficiency in infancy.

The occurrence of hemorrhagic disease due to vitamin K (VK) deficiency beyond the neonatal period has come under investigation in Japan. In 1980 the 1st nationwide survey was conducted in Japan by Nakayama and others, and was followed by the 2nd nationwide survey in 1985 by Hanawa. The present survey was designed to further monitor the incidence of this disease in Japan during the 3-year period from July 1985 to June 1988. Questionnaires were sent to 1,315 hospitals having more than 200 beds, located throughout Japan. Responses were received from 775 hospitals, for an answer rate of 58.9%. The total number of reported cases was 175, including 129 idiopathic type, 28 secondary type and 18 near-miss type. In this survey it was revealed that the incidence rate of the idiopathic type of vitamin K deficiency in infancy (VKDI) has decreased remarkably, to about one-fourth that reported in the first survey. The declining incidence rate of VK deficiency in Japan is considered to be the result of ever more widespread prophylactic administration of VK during the neonatal period, as most occurrences of VK deficiency in infancy are preventable by prophylactic administration of VK from the neonatal period. However, in 16 cases of the idiopathic type of VK deficiency found in the present survey, VK had been administered at least once during or after the neonatal period. This shows the heterogeneity of this condition.

Female↗
PubMed1990

Effects of a highly basic region of human immunodeficiency virus Tat protein on nucleolar localization.

Human immunodeficiency virus type 1 encodes a positive trans-activator protein, Tat, which is located predominantly in the cell nucleolus. To study the role of the basic region of Tat in nucleolar localization, we constructed fusion genes encoding serially deleted segments of Tat joined to the amino-terminal end of the Escherichia coli beta-galactosidase molecule. We show that the basic region of Tat was sufficient for nuclear localization but not for nucleolar localization. Addition of three amino acids (59, 60, and 61) of the Tat sequence at the C-terminal end of the basic region was necessary for the chimeric beta-galactosidase to localize in the nucleus as well as in the nucleolus. We demonstrate that a short amino acid sequence (G-48 RKKRRQRRRA HQ N-61), when fused to the amino terminus of beta-galactosidase, can act as a nucleolar localization signal.

Amino Acid Sequence↗
PubMed1990

Comparison of amniotic fluid disaturated phosphatidylcholine, phosphatidylglycerol and lecithin/sphingomyelin ratio in predicting the risk of developing neonatal respiratory distress syndrome.

One hundred forty-one amniotic fluid samples were analyzed for disaturated phosphatidylcholine (DSPC), phosphatidylglycerol (PG) and the lecithin/sphingomyelin (L/S) ratio. The L/S ratio was measured by two-dimensional thin layer chromatography. Mature levels (positive) were defined as an L/S ratio of 2:1 or more, a DSPC level of 100 micrograms/ml or more and a detectable level of PG. The DSPC value agreed with the L/S ratio in 114 samples (80.9%). Fourteen of 17 infants with respiratory distress syndrome (RDS) (82.4%) had immature L/S ratios and immature DSPC levels. RDS developed in 16 of 40 (40%) children with immature L/S ratios, and in 15 of 33 (45.5%) children with immature DSPC levels. The true-positive rates of the L/S ratio and DSPC levels were 99.0 and 98.1%, respectively. PG had a low true-negative rate, as only 17 of 67 (25.4%) samples without detectable levels of PG were associated with RDS. However, when PG was present, it had a 100% predictive value of no-RDS. In conclusion, DSPC is nearly equal to the L/S ratio measured by two-dimensional as concerns diagnostic accuracy. PG is useful as an additional index for predicting lung maturation.

Amniotic Fluid↗
PubMed1990

Iodomethylnorcholesterol uptake in an aldosteronoma shown by dexamethasone-suppression scintigraphy: relationship to adenoma size and functional activity.

Dexamethasone-suppression (DS) adrenal scintigraphy localizes an aldosteronoma, but with false-negative results, i.e. 2 of 19 cases in our study. Our aim was to clarify the clinical meaningfulness of this test. Adrenal iodomethyl-norcholesterol (NP-59) uptake on the adenoma side correlated with the estimated adenoma volume (n = 15, r = 0.843, P less than 0.001). Accordingly, the uptake ratio on the adenoma side to that on the opposite side depended on the adenoma volume (r = 0.683, P less than 0.01). This explains the false-negative results (uptake ratio less than 2) in two cases with small adenomas. The NP-59 uptake correlated weakly with the plasma aldosterone level (r = 0.516, P less than 0.05). This result indicates the low correlation between NP-59 uptake and the ability to secrete aldosterone. NP-59 accumulation in the surgically removed gland was analyzed by autoradiography in six cases where DS scintigraphy was done just before surgery. The density was higher in the adenoma cells than in the adjacent cortical cells in five cases, but the difference was rather small, i.e., within a 2-fold difference in four cases. In one case, almost the same density was observed in both types of cells. Thus, the laterality of NP-59 uptake primarily depends on the adenoma volume although NP-59 uptake somewhat reflects the adenoma's ability to secrete aldosterone or the adenoma cell's activity in accumulating NP-59. Care must be taken in interpreting the findings from DS scintigraphy where the adenoma is small or adrenal uptake is low.

Adenoma↗
PubMed1990

An enzyme-linked immunosorbent assay system for quantitative determination of calphobindin I, a new placental anticoagulant protein, and its application to various specimens.

We developed a sandwich enzyme-linked immunosorbent assay (ELISA) system for calphobindin I (CPB-I), a new placental coagulation inhibitor, using two monoclonal antibodies. This ELISA system can detect CPB-I at concentrations of between 0.4 and 25 ng/ml in buffer and allow almost quantitative determination of it in human plasma. Using this ELISA system, CPB-I levels in many kinds of specimens were measured. Levels in the plasma and urine of women were as low as 10 ng/ml, and no significant differences were observed throughout the trimesters of pregnancy and during different stages of the menstrual cycle. Toxemic patients were slightly higher in CPB-I levels than normal pregnant women, and levels in body fluids such as the amniotic fluid, saliva, milk, ascites, and semen were higher than those in the plasma. The high levels of CPB-I were found, being in the order of micrograms/ml, in the ascites of carcinomatous peritonitis as well as seminal plasma. Measurements of the levels in ovarian follicular fluid samples at different stages of the menstrual cycle showed that those in the immature and atretic stages were higher than those in mature stages. CPB-I levels in many types of cultured human cells ranged from 0.023 to 10.30 micrograms/mg protein, and levels in cultured human lymphocytes were less than those in other types of cells measured. Little of this inhibitor was secreted into media from cultured human lymphocytes, and it was found in all measured tissues of Macacus irus at levels ranging from 0.232 to 1.557 micrograms/mg protein. From these results, it was suggested that CPB-I might be a ubiquitous protein in the body that has an important physiological role.

Animals↗
PubMed1990

Treatment of disseminated intravascular coagulation with low molecular weight heparin. Research Group of FR-860 on DIC in Japan.

A multicenter cooperative study was carried out involving 47 nationwide institutions in Japan to assess the efficacy and safety of LMWH (FR-860) in DIC. Fifty-six cases were challenged by FR-860 injection principally for 5 days at doses of 75 U/kg/day in group I (n = 27) and 150 U/kg/day in group II, (n = 29). Scoring points were defined based on the severity of bleeding symptoms, organ failures, and abnormal coagulation-fibrinolytic tests. Therapeutic effects of FR-860 were evaluated objectively according to degrees of improvement of these scores. Six patients (10.7%) died of their underlying diseases or complications other than DIC. Hemorrhagic side effects occurred in 1 and 3 cases of groups I and II, respectively. Bleeding symptoms improved excellently or moderately in 45.5 and 31.6% of the cases in groups I and II, respectively. Concerning organ failures and coagulation-fibrinolytic tests, remarkable improvement was observed in 31.6 and 66.7% of the cases of the group I, whereas they remained 14.3% and 51.7% in group II. The overall usefulness of FR-860 was 66.7% in group I and 58.6% in group II. These results demonstrate that FR-860 is effective in DIC at a dose of 75 U/kg/day.

Aged↗
PubMed1990

Possible involvement of calpain in down-regulation of protein kinase C.

Calpain is known to play a variety of cellular functions in various cells by Ca2(+)-dependent limited proteolysis. Protein kinase C (PK-C) is a key enzyme in signal transduction. It is known that treatment of a cell with 12-0-tetradecanoylphorbol 13-acetate (TPA) causes down-regulation of PK-C, and that calpain can cleave PK-C into catalytic and regulatory fragments in vitro. In vivo involvement of calpain in down-regulation of PK-C was studied with neuroblastoma cells using various drugs, a synthetic peptide fragment of calpastatin and inhibitors against calpain. TPA-dependent down-regulation of PK-C was partially inhibited by pre-treatment with calpastatin peptide and inhibitors, suggesting in vivo involvement of calpain in down-regulation of PK-C during signal transduction.

Amino Acid Sequence↗
PubMed1990

[Anticoagulant therapy in obstetrical disorders].

Three kinds of anticoagulant therapy for obstetrical DIC were studied. 1. Antithrombin-III (AT) or gabexate mesilate for acute DIC, mainly for abruptio placentae. 2. Heparin or heparin-AT combination therapy for toxemia pregnancy. 3. Low molecular weight heparin (LMWH) for fetus of intrauterine growth retardation (IUGR). The results obtained were as follows, 1. a) Platelet count, and fibrinogen were significantly increased in AT therapy group compared with gabexate mesilate group. b) In clinical manifestation, renal failure and hemorrhagic diathesis were improved especially in AT group. 2. In heparin-AT group, high systolic blood pressure was improved during administration of AT, the high level of thrombin antithrombin complex was also found in these period. 3. a) The improvement of the gain of estimated fetal body weight was found after administration of LMWH. b) Redistribution of blood flow in one case of severe IUGR was observed during administration of LMWH.

Antithrombin III↗
PubMed1990

Factors influencing the binding of calpain I to human erythrocyte inside-out vesicles.

The mechanism for binding of human erythrocyte calpain I to human erythrocyte inside-out vesicles was studied by immunoelectrophoretic blot analysis. Binding of calpain I to inside-out vesicles was observed both in the absence and presence of Ca2+. Moreover, in the absence of Ca2+, acidic proteins like casein, ovalbumin and calpastatin suppressed while basic proteins like arginase and lysozyme did not affect the binding of calpain I to inside-out vesicles. Here, we propose a model for the binding of calpain to the membrane.

Arginase↗
PubMed1990

[Long-term follow-up study of I-131 therapy for Graves' disease--index associated with late-onset hypothyroidism].

We have studied the follow-up of thyroid function in the patients with late-onset hypothyroidism and euthyroidism after I-131 therapy of hyperthyroidism. Thirty three patients who did not need the thyroid treatment until ten years after I-131 therapy were classified as euthyroid group. And eleven patients who needed the thyroid supplement of thyroid hormone for late-onset hypothyroidism were classified as hypothyroid group. Patients in both groups who required only a single dose of I-131 for successful treatment of hyperthyroidism had similar age, gland size, 24 hour I-131 uptake, pretreatment serum T3 uptake level and T4 concentration, and I-131 treatment dose. Subclinical hypothyroidism occurred in 28.6% of euthyroid group and 66.7% of hypothyroid group four months after I-131 therapy. The levels of T3 were recovered to higher than normal range at 6 months in euthyroid group, while the levels of T3 were kept within the normal range in the seventy percent of hypothyroid group. Patients who were still lower in the level of T3 uptake than normal range at 6 months had a higher incidence of late-onset hypothyroidism. Our observation showed no significant difference in the course of follow-up studies after I-131 therapy between the patients with late-onset hypothyroidism and euthyroidism.

Adult↗
PubMed1989

Inhibition of calpain by a synthetic oligopeptide corresponding to an exon of the human calpastatin gene.

Calpastatin is a widely distributed endogenous inhibitor protein specifically acting on calpain (Ca2+-dependent cysteine endopeptidase). The inhibitor consists of four inhibitory domains (Domains 1-4) with mutually homologous sequences. NH2-terminal Domain L is non-homologous, and all domains have 120-140 residues each. A human calpastatin genomic DNA clone was isolated using a previously obtained human calpastatin cDNA probe. Sequence analysis has revealed that the clone contains Domain 1 and segments of neighboring domains (Domains L and 2). Each of three highly conserved, restricted regions within Domain 1 was located on separate exons, 1A, 1B, and 1C. Exon 2A, corresponding to the first exon of Domain 2, is homologous to Exon 1A and follows Exon 1D of Domain 1. A 27-residue peptide encoded by Exon 1B, including a 12-residue middle conserved sequence, was chemically synthesized and tested for protease inhibitory activities. The synthetic peptide showed strong inhibition against calpain I (low Ca2+-requiring form), and calpain II (high Ca2+-requiring form), but no inhibition against papain or trypsin. These results indicated that Exon 1B forms a self-sufficient functional subdomain of the calpastatin inhibitory domain.

Amino Acid Sequence↗
PubMed1989

Functional similarity of HIV-I rev and HTLV-I rex proteins: identification of a new nucleolar-targeting signal in rev protein.

We have tested the functional compatibility between rev protein of human immunodeficiency virus type I (HIV-I) and rex protein of human T-cell lymphotropic virus type I (HTLV-I). Each protein recognized the other's cis-acting sequence, albeit at reduced levels. Both proteins localize predominantly in the nucleolus. We have identified a new nucleolar-targeting signal in rev protein, which was homologous to that of rex protein. The sequence [35-RQARRNRRRRWRERQR-50] in rev protein, when fused to the amino-terminus of beta-galactosidase, directed the hybrid protein to the cell nucleolus. A deletion mutant which lacks several amino acid residues within the signal failed to function in the CAT assay system. These results demonstrate that the nucleolar targeting signals are essential for the functions of Rev and Rex.

Amino Acid Sequence↗