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Biomedical subjects

M Higuchi

Publications and source records attributed to M Higuchi.

At least 271 records · Page 15Linked to original sources
PubMed1990

Effects of recombinant human erythropoietin on haemolytic anaemia in mice.

The effects of repeated administration of recombinant human erythropoietin (rHuEPO) were investigated in mice with haemolytic anaemia. Mice with haemolytic anaemia induced by phenylhydrazine (PHZ mice) were examined as an acute model and New Zealand black mice (NZB mice) at 13 months of age were examined as a chronic model. The plasma erythropoietin (EPO) level in PHZ mice was high and showed a strong inverse correlation with the Hb in the anaemia development period. However, it was relatively low in the recovery period from anaemia. On the other hand, the plasma EPO level in NZB mice showed a simple inverse correlation with the Hb. The rHuEPO was injected every day for a week into these mice. While a high plasma EPO level was maintained in PHZ mice, no significant effect was observed by injection with rHuEPO at dose of 600 IU/kg. However, in the recovery period from anaemia, RBC and haemoglobin in PHZ mice were increased by the rHuEPO treatment and recovered more quickly to their normal levels. In NZB mice, RBC and haemoglobin were also increased by treatment with rHuEPO at dose of 600 IU/kg. Anti-RBC autoantibodies and anti-EPO antibodies did not increase, while RBC and plasma EPO levels were increased by the rHuEPO treatment. These results suggest that some types of haemolytic anaemia are not always combined with high endogenous EPO levels and that exogenous rHuEPO may be effective for use in the treatment of haemolytic anaemia.

Acute Disease↗
PubMed1990

Effect of recombinant human erythropoietin on anticancer drug-induced anaemia.

Anaemia was induced in rats with fluorouracil (5-FU) or cisplatin (CDDP) and the mechanisms of anaemia induction were analysed. Furthermore, the therapeutic effects of recombinant human erythropoietin (rHu Epo) on these anticancer drug-induced anaemias were investigated. In 5-FU-induced anaemia, marked serum erythropoietin (Epo) elevation was observed in inverse correlation to blood Hb concentration and Hb concentration rapidly recovered to normal levels. On the other hand, in CDDP-induced anaemia, serum Epo elevation was modest and the lowered Hb concentration persisted longer. Treatment with rHu Epo significantly improved both anticancer drug-induced anaemias but rHu Epo was more effective on CDDP-induced anaemia. These results suggest that rHu Epo might be useful for the therapy of anaemia associated with anticancer chemotherapy.

Anemia↗
PubMed1990

Plasma lipid and lipoprotein profiles in pre- and post-menopausal middle-aged runners.

Plasma lipid and lipoprotein profiles were compared in middle-aged trained and untrained women before and after menopause. Subjects were assigned to one of four groups: (1) pre-menopausal trained (Pre-T: n = 17, aged 42 +/- 5 years, body fat 19 +/- 5%, training distance 53 +/- 20 km week-1, VO2max 49 +/- 4 ml kg-1 min-1, mean +/- SD); (2) pre-menopausal untrained (Pre-UT: n = 26, 42 +/- 5 years, 24 +/- 7%, 34 +/- 6 ml kg-1 min-1); (3) post-menopausal trained (Post-T: n = 16, 54 +/- 3 years, 20 +/- 4%, 43 +/- 19 km week-1, 41 +/- 5 ml kg-1 min-1); and (4) post-menopausal untrained (Post-UT: n = 15, 55 +/- 3 years, 25 +/- 6%, 31 +/- 3 ml kg-1 min-1). There were no significant differences in total cholesterol (range 173-194 mg dl-1), triglyceride (56-72 mg dl-1), and HDL-cholesterol (HDLC: 76-85 mg dl-1) among the four groups. LDL-cholesterol (LDLC) in the post-menopausal women (Post-T: 96 +/- 32 mg dl-1; Post-UT: 104 +/- 23 mg dl-1) tended to be higher than in the premenopausal women (Pre-T: 86 +/- 25 mg dl-1, Pre-UT: 81 +/- 23 mg dl-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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

[Studies on the preparation and evaluation of Kijitsu, the immature citrus fruits. III. Relation between diameter of Kijitsu and synephrine content].

For the purpose of evaluating Kijitsu, the content of synephrine in dried unripe citrus fruits was analyzed by high performance liquid chromatography after cleaning up the MeOH extract with an ion exchange cellulose column. Among them, Citrus unshiu had the highest amount of synephrine. No difference was found between C. hassaku and C. aurantium. The synephrine content decreased corresponding with an increase in diameter of Kijitsu.

Chromatography, High Pressure Liquid↗
PubMed1990

Improvement of hypoperfusion with norepinephrine injury by ex vivo insulin in isolated diabetic rat hearts.

Effects of insulin on contractile and energy metabolic dysfunctions during hypoperfusion (2 ml/min/g heart wt., 60 min) with 10(-6) M norepinephrine were studied in paced hearts isolated from streptozotocin-diabetic rats. Insulin (2 mU/min/g heart wt.) was infused 20 min before and during hypoperfusion (pre-treated group) or 30 min after the onset of hypoperfusion (post-treated group). Hearts in the non-treated group were hypoperfused without insulin and other hearts in the control group were not hypoperfused. In the non-treated group, resting contractile force (CF) and resting left ventricular pressure (LVP) were significantly elevated to maximum levels within 30 min after hypoperfusion and these elevations were restored in the pre-treated group but not in the post-treated group. Developed CF was depressed in the non-treated group and improved significantly in the pretreated group but not in the post-treated group. Developed LVP was depressed in the non-treated group, and depression was slightly larger in the pre-treated group. In the non-treated group, ATP and creatine phosphate contents in the left ventricle significantly decreased. Decreases in ATP and creatine phosphate contents in the inner layer were partially restored in the pre-treated group but not in the post-treated group. Lactate significantly increased in the non-treated group and increased even further in the insulin treated groups. These results indicate that contractile dysfunction during hypoperfusion with norepinephrine is improved by pre-treated insulin, as is partial recovery of energy metabolism.

Adenosine Triphosphate↗
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

[Management with antithrombin III concentrate in a pregnant woman with hereditary antithrombin III deficiency].

Pregnant women with hereditary antithrombin III (AT-III) deficiency are frequently associated with thromboembolic disorders. We have treated a pregnant woman with hereditary AT-III deficiency, who had suffered from thromboembolic disorders at her past three gestations, with AT-III concentrate. Dosage of AT-III concentrate to maintain plasma AT-III activity over 80% was 3,500 units per week during second and third trimesters, but more frequent administration was necessary around delivery. In recent reports, pregnant women with hereditary AT-III deficiency had been treated with heparin or warfarin except for during abortion and delivery, in which time AT-III concentrate was widely utilized. But the use of heparin or warfarin during gestation is occasionally harmful, AT-III concentrate should be chosen for management in pregnancy in women with hereditary AT-III deficiency.

Adult↗
PubMed1990

[MR imaging of splenic masses].

It has been reported that MR imaging of the spleen is unsuccessful in detecting focal lesions because there is not a significant difference in relaxation times between most tumors and surrounding normal spleen. We reviewed the MR imaging of 15 patients (5 cysts, 2 abscesses, 1 hemangioma, 5 malignant lymphomas, 2 metastatic tumors). In all cases, the difference in signal intensities between splenic tissue and mass lesions permitted detection of splenic lesions on MR images. But, malignant lesions were less visible than benign lesions.

Adult↗
PubMed1990

[CT findings of the benign tracheobronchial lesions with calcification].

In the benign tracheobronchial lesions with calcification, tracheobronchopathia osteochondroplastica, relapsing polychondritis and tracheobronchial amyloidosis were considered. CT demonstrated small nodules with calcifications at the trachea with or without deformity of tracheal wall in the case of tracheobronchopathia osteochondroplastica, swelling of tracheal cartilage with diffuse and multiple calcifications in the case of relapsing polychondritis and calcifications in the deep parts of tracheobronchial amyloid nodules. CT findings were able to differentiate those benign lesions. High-resolution CT is more useful in the distribution of abnormal calcification of these diseases.

Aged↗
PubMed1989

A new index for collagen induced platelet aggregation.

In this paper, we propose a new index of platelet aggregation for optical aggregometry, the "R" value. This represents the rate of change in the half time for platelet aggregation (T1/2) induced by collagen with changes in the platelet concentration and expresses the degree of platelet sensitivity to collagen. The "R" value has been shown to reflect the aggregability of platelets due to activation of the contact factors. The "R" values were significantly different in the acute and chronic phases of occlusive arterial disease, while ordinary platelet aggregation parameters did not change. A decrease in the "R" value appears to indicate a platelet hyperfunction and hypercoagulable state, in other words a prethrombotic state.

Adenosine Diphosphate↗
PubMed1989

Molecular defects in hemophilia A: identification and characterization of mutations in the factor VIII gene and family analysis.

Hemophilia A is an X-linked bleeding disorder caused by a deficiency or abnormality of factor VIII, affecting approximately 1 male in 10,000. A subgroup of the patients develops inhibitors against factor VIII during substitution therapy. Because a considerable percentage of all cases is thought to result from de novo mutations, it is likely that many different molecular lesions lead to hemophilia A. In order to understand the molecular basis of this disorder, we examined 160 patients with different clinical features using factor VIII gene probes. We could identify six different deletions and seven nonsense mutations within the factor VIII gene. Family analysis revealed that five of these mutations occurred de novo within two generations; two of them arose in the maternal grandfather and three in the mother. In one of these mothers we could identify a mitotic origin. Mapping of the deletions showed no deletion-prone region within the gene. Furthermore, we could not find any correlation between the particular gene defects and "inhibitor" phenotypes.

Base Sequence↗
PubMed1989

Fibrinogenolysis in thrombotic thrombocytopenic purpura.

Coagulo-fibrinolytic factors were studied in five patients suffering from thrombotic thrombocytopenic purpura (TTP). The change in coagulation factors in the acute stage was mild compared with that found in disseminated intravascular coagulation (DIC). We observed a slight increase of fibrin-fibrinogen degradation products (FDP) in the plasma of four patients during the acute stage of TTP, but the level of the D-dimer remained within normal variation and was extremely low compared with that in 27 samples from patients with DIC showing the same level of FDP. At the same time, both antigen levels of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type 1 (PAI-1) were elevated in three of the four patients tested. Although a similar change was recognized in DIC patients' plasma, the elevation of PAI-1 in the acute stage of TTP was far higher than in overt DIC. The antigen levels of t-PA and PAI-1 were normal in remission, and a mild elevation of PAI-1 was detected in one of the three patients during the early stage of TTP relapse. Enzymography revealed the appearance of free t-PA and an increase of a substance with a 110 kD molecule, assumed to be a t-PA and PAI-1 complex, in TTP plasma in the acute stage, but the findings were normal for plasma from cases in remission and the early stage of relapse. Enzymography also showed a decrease of urokinase-type plasminogen activator (u-PA) only in the acute stage of TTP. These changes in the coagulo-fibrinolytic factors in the acute stage of TTP suggest that fibrinogenolysis might be induced by t-PA, released through vascular reaction at an uninvolved area of vascular lesions caused by platelet agglutinates, which would then release large amounts of PAI-1 inhibiting t-PA and u-PA activities at the occlusive lesion.

Adolescent↗
PubMed1989

Cardiovascular changes associated with decreased aerobic capacity and aging in long-distance runners.

Fifty-five male runners aged between 30 to 80 years were examined to determine the relative roles of various cardiovascular parameters which may account for the decrease in maximal oxygen uptake (VO2max) with aging. All subjects had similar body fat composition and trained for a similar mileage each week. The parameters tested were VO2max, maximal heart rate (HRmax), cardiac output (Q), and arteriovenous difference in oxygen concentration (Ca-Cv)O2 during graded, maximal treadmill running. Average body fat and training mileage were roughly 12% and 50 km.week-1, respectively. The average 10-km run-time slowed significantly by 6.0%.decade-1 [( 10-km run-time (min) = 0.323 x age (years) + 24.4] (n = 49, r = 0.692, p less than 0.001]. A strong correlation was found between age and VO2max [( VO2max (ml.kg-1.min-1) = -0.439 x age + 76.5] (n = 55, r = -0.768, p less than 0.001]. Thus, VO2max decreased by 6.9%.decade-1 along with reductions of HRmax (3.2%.decade-1, p less than 0.001) and Q (5.8%.decade-1, p less than 0.001), while no significant change with age was observed in estimated (Ca-Cv)O2. It was concluded that the decline of VO2max with aging in runners was mainly explained by the central factors (represented by the decline of HR and Q in this study), rather than by the peripheral factor (represented by (Ca-Cv)O2).

Adult↗
PubMed1989

Cytofluorometric study on lectin binding of isolated guinea pig keratinocytes.

Lectin binding was cytofluorometrically measured on fractionated keratinocytes of guinea pig. Free keratinocytes were obtained by treatment of EDTA and trypsin. After the treatment, they were separated into 3 fractions by centrifugation on a continuous colloidal silica (Percoll) density gradient. Cells in each fraction were stained by biotinyl lectins and avidin-FITC, and fluorescence intensity was measured by cytofluorometry. Results obtained indicate that little cell surface glycoconjugate is lost during the preparation of free keratinocytes.

Animals↗
PubMed1989

Direct characterization of factor VIII in plasma: detection of a mutation altering a thrombin cleavage site (arginine-372----histidine).

An immunoadsorbent method has been developed for the direct analysis of normal and variant plasma factor VIII. Using this method, the molecular defect responsible for mild hemophilia A has been identified for a patient whose plasma factor VIII activity is 0.05 unit/ml, even though the factor VIII antigen content is 3.25 units/ml. Although the variant factor VIII has an apparently normal molecular mass and chain composition, the 92-kDa heavy chain accumulates when the variant protein is incubated with thrombin and the 44-kDa heavy chain fragment cannot be detected. In contrast, thrombin cleavage of the 80-kDa light chain to the 72-kDa fragment is normal. As these data indicate a loss of factor VIII cleavage by thrombin at arginine-372, the genetic defect was determined by polymerase-chain-reaction amplification of exon 8 of the factor VIII gene and direct sequencing of the amplified product. A single-base substitution (guanine----adenine) was identified that produces an arginine to histidine substitution at amino acid residue 372. These data identify the molecular basis of an abnormal factor VIII, "factor VIII-Kumamoto," that lacks procoagulant function because of impaired thrombin activation.

Arginine↗