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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 1,117 records · Page 62Linked to original sources
PubMed1985

Effects of dopamine agonists on hypothalamic defensive attack in cats.

The effects of methamphetamine (MAT) and apomorphine (APO), dopamine agonists, were studied in 16 cats to evaluate their effects on threshold for defensive attack behavior elicited by electrical stimulation of the ventromedial hypothalamic nucleus (VMH). Directed attack and hissing were selected from elementary responses as constituting a defensive attack. Hissing threshold was measured in two situations, one with human provocation and the other without provocation. MAT administered systemically lowered the thresholds for all three types of responses in a dose-related manner (0.5, 1.0, and 3.0 mg/kg). The effects of 1.0 mg/kg of APO were almost identical to those observed with 0.5 or 1.0 mg/kg of MAT. These results suggest that MAT-induced aggressive behavior may be mediated by a dopamine-induced increase in the excitability of the VMH.

Aggression↗
PubMed1985

Anticarcinogenic action of an alcohol-insoluble fraction (LAP1) from culture medium of Lentinus edodes mycelia.

From the culture medium of Lentinus edodes mycelia, water-soluble material (LEM) was prepared and further fractionated by alcohol precipitation and gel filtration on Sepharose 6B. The resulting fraction of xylose-rich proteoglycan at the void volume was designated as LAP1. The 25% and 50% survival rates of hepatoma-bearing rats were raised by intraperitoneal (i.p.) administration of LAP1 at doses of 3-10 mg/kg (an optimum dose, 3 mg/kg). This fraction did not suppress in vitro cell proliferation of the hepatoma. Moreover, the i.p. administration of LAP1 significantly augmented the activity of macrophage-migration inhibition of the splenic cells from hepatoma-bearing rats in the early stage after transplantation. Thus, the anticarcinogenic action of LAP1 would partly be interpreted by host-dependent immunomodulation.

Animals↗
PubMed1985

A method for predicting postoperative lung function and its relation to postoperative complications in patients with lung cancer.

We predicted the postoperative forced expiratory volume in 1 second (FEV1) with a formula based on the premise that the total number of subsegments was 42: postop FEV1 = [1 - (b - n)/(42 - n)] (preop FEV1), where n and b are the number of obstructed subsegments and total subsegments, respectively, in the resected lobe. It was assumed that b was 6, 4, and 12 in the right upper, middle, and lower lobes, respectively, and 10 each in the left upper and the left lower lobes. The obstructed subsegments, n, were obtained from the findings on bronchography or bronchofiberscopy or both before operation. The linear regression line derived from the correlation between predicted (x) and measured (y) FEV1 was y = 0.850x + 0.286 +/- 0.296 (standard error) (N = 52; r = 0.821; p less than 0.001). We calculated the predicted postoperative FEV1 in 188 patients with primary lung cancer. The predicted values were corrected with the regression equation just mentioned and then normalized by the patient's height and sex (%FEV1(p,c). The correlation between %FEV1(p,c) and the surgical risk was studied. Postoperative respiratory complications were inversely related to %FEV1(p,c), and a significantly high incidence of complications (p less than 0.05) was observed in those whose %FEV1(p,c) was less than 60% of predicted normal. In aged patients (65 years old or more) without complications, %FEV1(p,c) was 67.3 +/- 18.0%; it was 52.2 +/- 12.8% in those with respiratory trouble and 53.3% +/- 9.6% in those with circulatory complications. The difference between groups with and without complications was significant (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1985

The serratial 56K protease as a major pathogenic factor in serratial keratitis. Clinical and experimental study.

A possible cause and the difference in clinical severity of serratial keratitis were investigated. Two strains of Serratia marcescens were isolated: one from a patient with severe liquefactive keratitis, who had diabetes mellitus, and one from a patient with mild superficial keratitis, but who had no underlying disease. When the same numbers of bacteria were injected separately into corneas of the same rabbits or guinea pigs, the strain from the first patient elicited severe corneal destruction, remarkable intracorneal edema; and liquefactive necrosis, but the strain from the second caused mild keratitis with erosion or intracorneal abscess. The keratitis induced by the former strain required a longer time to heal, and the prognosis was poorer than that for the other keratitis. Therefore, the difference in severity between the two cases of experimentally induced keratitis paralleled that of the clinical cases. Thus, the severity of the serratial keratitis might be attributed more to the virulence of the bacteria than the condition of the host. The virulence factor seemed to be a heat-labile metabolic product (or products) of the bacteria. To clarify this virulence factor, the major secretory protease (56K protease) produced by these two strains of bacteria was compared by using in vitro and in vivo systems. The virulent strain produced about ten times more protease during culture than the less virulent strain. When injected into the corneas of experimental animals, the 56K protease from the virulent strain induced severe lesions similar to those caused by the living virulent strain of bacteria. These results indicated that one of the major factors causing the virulence was correlated with the tissue destructive 56K protease produced by S. marcescens.

Aged↗
PubMed1985

Familial odontogenic keratocysts. Report of 3 cases and review of Japanese dental literature.

Familial odontogenic keratocysts are described in this report. The Case 1 patient, who has 3 sisters, developed odontogenic keratocysts. The 2 younger sisters (Cases 2 and 3) also had odontogenic keratocysts, although the elder sister did not have any odontogenic cysts. The father of the patients had a history of removal of a jaw cyst, and the mother was found later to have malignant ameloblastoma. Besides the odontogenic keratocysts, the Case 1 patient had basal cell nevus, prominent frontal process, and ocular hypertelorism; the Case 2 patient had prominent frontal process; the Case 3 patient had prominent frontal process, ocular hypertelorism, and squint. All 3 sisters are suspected of being patients with the basal cell nevus syndrome. The Japanese dental literature concerning the basal cell nevus syndrome is reviewed.

Adolescent↗
PubMed1985

Conjugation of poly(styrene-co-maleic acid) derivatives to the antitumor protein neocarzinostatin: pronounced improvements in pharmacological properties.

An anticancer agent of intermediate molecular weight and having both a hydrophilic and hydrophobic nature was developed by utilizing the antitumor protein neocarzinostatin (NCS; Mr = 12000) as a prototype drug. The modification was achieved by reacting the two amino groups on NCS with an anhydride group of partially half-esterified (p-E-) or partially hydrolyzed (p-H-) poly(styrene-co-maleic anhydride) (SMA) in 0.8 M NaHCO3. The SMA samples with narrow molecular weights distributions (Mw = ca. 2000) were prepared by copolymerizing styrene and maleic anhydride in cumene followed by fractionation by means of a column-elution method. The derivatives p-E- or p-H-SMA were then formed by using the appropriate monoalcohols or H2O, respectively. These SMA derivatives contain about 2 mol of anhydride residues/mol of SMA. The reaction product, SMA-conjugated NCS (designated as SMANCS), was purified by dialysis followed by gel filtration with Sephadex G-75. The complete reaction yielded essentially a single product, biantennary SMANCS. The molecular weight of the pure SMAMCS was estimated by various methods, including polyacrylamide gel electrophoresis with NaDodSO4, HPLC in the gel permeation mode, fluorescence polarization, and a decrease in both nitrogen and protein contents. These results agree with the apparent molecular weight of about 16000. Characters of SMANCS was considerably altered from that of parental NCS: solubility characteristics in both organic and aqueous solvents were changed, the biological half-life in blood was prolonged 10 times, and antitumor activity became more pronounced, but the toxicity was reduced to one-fourth of the parental NCS. Thus, the present study has provided a method of improving biologically active substances by polymer conjugation.

Animals↗
PubMed1985

Identification of a polymorphic variant associated with HLA-DQw3 and characterized by specific restriction sites within the DQ beta-chain gene.

Restriction endonuclease digestion of genomic DNA from 24 lymphoblastoid cell lines homozygous for the HLA class II specificity DQw3, followed by hybridization with a DQ beta-chain cDNA probe, identified a genomic polymorphism with variable BamHI and HindIII recognition sites. This restriction fragment pattern was found for several haplotypes associated with the DQw3 specificity, including some haplotypes positive for the HLA-DR specificities DR4, DR5, DRw8, and DRw12. The variant fragment pattern corresponds precisely with the reactivity of a monoclonal antibody, A-10-83, previously shown to define a serologic split of DQw3. Serologic detection of the specific DQw3.1 genomic polymorphism indicated that the corresponding DQ beta-chain variants are expressed. This polymorphic restriction fragment pattern, then, represents a selective marker for DQ beta-chain genes that appear to define a DQ beta-chain-associated specificity, here called DQw3.1.

Antibodies, Monoclonal↗
PubMed1985

Nutritional influences on aging of Fischer 344 rats: II. Pathology.

The aim of this study was to explore the effects of nutritional manipulations on the occurrence and progression of age-related pathologic lesions in male Fischer 344 rats. The following nutritional regimens were studied: (a) ad libitum feeding, (b) food restriction initiated at 6 weeks of age, (c) food restriction initiated at 6 months of age, (d) food restriction limited to a period of early life (6 weeks to 6 months of age), (e) protein restriction without caloric restriction. The major age-related lesions observed were chronic nephropathy, cardiomyopathy, and neoplasia. Food restriction initiated at 6 months of age was as effective as food restriction initiated at 6 weeks of age in slowing the progression of chronic nephropathy and cardiomyopathy and in delaying the occurrence of neoplasia. Food restriction limited to early life was much less effective. Protein restriction in the absence of caloric restriction did not delay the occurrence of neoplasia, but it did retard chronic nephropathy and cardiomyopathy, although much less effectively than caloric restriction involving a similar level of protein restriction.

Aging↗
PubMed1985

Interaction of factor XII, high-molecular-weight (HMW) kininogen and prekallikrein with sulfatide: analysis by fluorescence polarization.

The interaction of high-molecular-weight (HMW) kininogen, Factor XII and prekallikrein with sulfatide was studied by fluorescence polarization. Fluorescein-conjugated derivatives of HMW kininogen, Factor XII and prekallikrein were prepared by reacting the purified bovine factors with fluorescein isothiocyanate (FITC). The apparent dissociation constant (Kd) for the binding of FITC-labeled HMW kininogen (F-HMW kininogen) with sulfatide was calculated to be 3.2 (+/- 0.3) X 10(-8) M. This binding was partially inhibited by three kininogen derivatives, fragment 1 X 2, kinin-free protein and fragment 1 X 2-light chain, but not by kinin and fragment 1 X 2-free protein. In the presence of Factor XII, the binding of F-HMW kininogen with sulfatide was strongly inhibited, suggesting that the zymogen and the protein cofactor compete for the same or a closely related binding site on the sulfatide surface. In contrast, the binding of FITC-labeled Factor XII (F-Factor XII) with sulfatide was weakly inhibited by HMW kininogen but not by prekallikrein. The Kd value for binding of F-Factor XII with sulfatide was calculated to be 2.0 (+/- 0.3) X 10(-8) M. F-Prekallikrein did not interact with sulfatide. Moreover, the fluorescence polarization value of F-HMW kininogen decreased in the presence of prekallikrein, leveling off at a one-to-one molar ratio of prekallikrein to F-HMW kininogen. The Kd value for binding of F-HMW kininogen-light chain (F-light chain) with prekallikrein was calculated to be 3.8 (+/- 0.6) X 10(-8) M and the stoichiometry was estimated as 1 to 1.2 on a molar basis from the Scatchard plot.

Animals↗
PubMed1985

Effect of shear rate on clot growth at foreign surfaces.

The hydrodynamic effect on clot growth at foreign surfaces was investigated quantitatively in vitro. Shear rates from 2 to 1,000 s-1 were applied to a blood sample contained in a cone and plate viscometer. Four different artificial materials were used for cone and plate combination, namely, stainless steel, polytetrafluoroethylene, polycarbonate, and polymethylmethacrylate. Evaluation of clot growth was derived from the clotting ratio (the volumetric fraction of clot in the whole blood), which was experimentally determined from the rate of increase of frictional torque between the rotating cone and the stationary plate. The results show that the clotting ratio decreases markedly as the shear rate increases to 400 s-1, regardless of material used. This study demonstrates that at a shear rate of greater than 400 s-1, clot growth at foreign surfaces is considerably inhibited.

Biophysical Phenomena↗
PubMed1985

Granulocytic and stromal progenitors in the bone marrow of patients with primary myelofibrosis.

Quantitative and qualitative changes in granulocyte-macrophage (CFU-GM) and fibroblast colony-forming cells (CFU-F) were studied in 7 patients with primary myelofibrosis (MF). Marrow cells were collected from bone biopsy specimens after treatment with collagenase. The number of CFU-GM correlated with the amount of haemopoietic tissue noted in the bone marrow histology and ranged between 0-400/mg of bone. CFU-F were increased in 2 patients with moderate fibrosis. Circulating CFU-GM were increased in all patients studied (169-3749/ml of blood). There was no significant correlation between the number of CFU-GM in the bone marrow and that in the blood. Cytochemical studies showed a high incidence in eosinophil progenitors in the bone marrow and especially in the blood of patients with MF. These data suggest a functional abnormality of myeloid progenitors in this disease.

Aged↗
PubMed1985

Expression of the platelet-common acute lymphoblastic leukaemia associated antigen on normal eosinophils.

A murine monoclonal antibody (TP82) raised against normal platelets was found to be reactive with eosinophils and common acute lymphoblastic leukaemia (cALL) cells, and some blast cells from patients with non-lymphoid leukaemia. The antibody showed that the platelet-cALL associated antigen (p24) is also expressed on normal eosinophils, and may prove useful for studying the function as well as the differentiation of eosinophils.

Animals↗
PubMed1985

A serratial protease causes vascular permeability reaction by activation of the Hageman factor-dependent pathway in guinea pigs.

The 56-kilodalton (56K) protease isolated from a culture filtrate of Serratia marcescens caused vascular permeability enhancement followed by edema formation when injected into guinea pig peripheral corneas and subconjunctival space or skin. The character and the mechanism of permeability enhancement were analyzed in vivo. The enhancement was maximum at 5 to 10 min. The permeability reaction increased exponentially by the amount of enzyme used. The enhancement of permeability induced by the 56K protease was not affected by treatment with an antihistamine but was greatly augmented by simultaneous injection of a kinin potentiator, Glu-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro-OH (SQ 20,881). Furthermore, the permeability activity of the protease, but not the amidolytic activity, was inhibited by soybean trypsin inhibitor, a well-known inhibitor of plasma kallikrein, as well as by corn trypsin inhibitor, the best inhibitor of activated Hageman factor. Results of these in vivo studies indicate that the permeability-enhancing reaction induced by the 56K protease is caused by activation of the Hageman factor-dependent pathway in the tissue. The permeability-increasing activity of the 56K protease was parallel with the enzyme activity. Serratial lipopolysaccharide did not produce a permeability enhancement reaction within 30 min when injected into guinea pig skin. These results are consistent with the results of recent in vitro experiments in which activation of the purified Hageman factor but not of prekallikrein by the 56K protease was elucidated (Matsumoto et al., J. Biochem. (Tokyo) 96:739-749, 1984). Thus, the molecular mechanism described above appears to be operative in the pathogenesis of corneal edema and chemosis, which is induced by S. marcescens, in addition to the direct tissue destruction by the protease.

Animals↗
PubMed1985

Hepatocellular carcinoma detected by iodized oil.

This study assesses the diagnostic value of Lipiodol (iodized oil) and computed tomography (CT) in detecting hepatocellular carcinoma (HCC). Twenty-four patients who were suspected of having HCC received injections of a small amount of Lipiodol, along with an antitumor agent, in the hepatic artery following routine celiac angiography. CT scans obtained 7-10 days after Lipiodol administration demonstrated HCC in distinct contrast to the surrounding noncancerous parenchyma. In particular, the CT-Lipiodol procedure disclosed many small HCC lesions that were not shown by celiac angiography, scintigraphy, CT with and without contrast medium enhancement, and ultrasonography. Although this procedure may miss very small or highly fibrotic lesions, it is recommended for patients suspected of having HCC and for patients for whom hepatic resection is being considered.

Adult↗
PubMed1985

Functional changes in marrow stromal cells in aplastic anaemia.

To determine whether or not abnormalities exist in the bone marrow stroma in aplastic anaemia, we analysed the ability of marrow stromal cells to support haemopoiesis using a long-term culture system. Marrow stromal cell layers from 3 of 9 patients with this disorder failed to maintain granulocyte-macrophage colony-forming cells in vitro. The stromal dysfunction was reversible in 1 patient who recovered after androgen therapy. The results of the present study add to the available evidence for a functional defect of marrow microenvironments in some cases of aplastic anaemia.

Adolescent↗
PubMed1985

Effect of simultaneous infusion of a somatostatin analogue, insulin and glucose on serum triglycerides and blood glucose levels in man.

Nine non-diabetic, non-obese, normocholesterolemic normal male subjects with varied triglycerides levels were subjected to a simultaneous infusion test with a synthetic somatostatin analogue [des(Ala1, Gly2)-D-Trp8, D-Asn3, 14-somatostatin], insulin and glucose under ambulatory conditions. The levels of C-peptide reactivity, immunoreactive glucagon and growth hormone were reduced, and the level of immunoreactive insulin remained constant during the infusion. The blood glucose reached a constant value at 110-120 minutes (steady state blood glucose, SSBG) after the commencement of the infusion. The total cholesterol (TC) levels decreased slightly in the 30 minutes after the experiments were begun, and the triglycerides (TG) levels decreased gradually throughout the infusion period, due mainly to the reduction of very low density lipoprotein (VLDL). The most striking finding was the highly significant positive correlation (p less than 0.005, r = 0.868) between SSBG and the serum TG level prior to the infusion. These results indicate an important relationship between insulin sensitivity and serum TG level. High TG level may be regarded as one of the indices of insulin resistance.

Adult↗