Search PubMed⌕ Search

Biomedical subjects

Y Hirano

Publications and source records attributed to Y Hirano.

At least 199 records · Page 11Linked to original sources
PubMed1992

Relationship between pulmonary arterial pressure and pulmonary thromboembolism associated with dead worms in canine heartworm disease.

To examine effects of thromboemboli due to dead worms on pulmonary arterial pressure (PAP), 20 to 50 dead heartworms were inserted into the pulmonary arteries of 4 heartworm uninfected dogs (uninfected group) and 11 dogs infected with heartworms (infected group). In the uninfected group, the mean PAP rose 1 week after worm insertion (10.9 to 166. mmHg), but it recovered by the 4th week. Clinical signs, hemodynamics and blood gas findings also deteriorated at the 1st week, but recovered at the 4th week. Angiographic and pathological findings indicated that blood flow recovered through the spaces between thromboemboli and vessel walls at the 4th week. The infected dogs were divided into three groups. In the infected-I group (5 dogs), the intimal lesions of the pulmonary arteries were slight, and clinical and laboratory findings showed changes similar to those of the uninfected group. In the infected-II group (4 dogs), the pulmonary arterial lesions were severe and the mean PAP was higher (25.7 mmHg) than in the uninfected group before worm insertion. An increase in PAP (34.1 mmHg) and worsening of clinical and laboratory findings were noticed till the 4th week. Thromboemboli adhered extensively to the vessel walls. Two dogs in the infected-III group died of severe dyspnea on the 9th and 10th day, and the mean PAP rose remarkably at the 1st week (from 19.4 to 28.2 mmHg). Severe pulmonary parenchymal lesions with edema or perforation were observed. From the above results, it was clarified that effects of dead worms on PAP and clinical signs depended on the severity of pulmonary arterial lesions before worm insertion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

[Usefulness of intraperitoneal carboplatin administration-- pharmacokinetic analysis].

A bolus of carboplatin (CBDCA) 200-450mg/body (148-292mg/m2) with 500ml saline was administrated into the abdominal cavity (ip) of 4 patients with ovarian cancer and 2 patients with uterine endometrial cancer, and concentrations of free and total platinum (Pt) in the blood and ascites were measured with the passage of time. Moreover, the results were analyzed with a 2-compartment model and moment analyses in order to study in vivo kinetics of CBDCA at the time of the ip administration. 1) The shift of Pt to blood through ip administration depended on the peritoneal clearance. Cmax in blood was seen one hour after ip in patients with a normal peritoneum, and was seen between 4 and 6 hours after ip in patients with peritonitis carcinomatosa. The level was lower in the latter group. 2) The non-binding rate of Pt with protein in the ascites at the time of the ip administration was correlated with the CBDCA concentration in the ascites. 3) The non-binding rate was 80% or more both in the ascites and in the blood within 4 hours after ip. The high level of the nonbinding rate appeared to cause prolongation of the presence of the free-Pt in the ascites and blood, especially in patients with peritonitis carcinomatosa. 4) AUC level in blood was equal to or higher than that observed when the same dose was administered iv. The levels of free-Pt and AUC in the abdominal cavity were 2 to 5 times higher than those in blood in patients with a normal peritoneum, and 7 to 14 times higher in patients with peritonitis carcinomatosa.(ABSTRACT TRUNCATED AT 250 WORDS)

Carboplatin↗
PubMed1992

[Renal cell carcinoma in a renal cyst--observation of changes during the year: report of a case].

We report a case of renal cell carcinoma within a renal cyst. A 45-year-old man visited our hospital with the chief complaint of left back pain. Ultrasonography was examined by a physician, and it revealed a right renal cyst by chance. Computed tomography demonstrated a thick wall in the cyst which showed enhancement of density with contrast medium. The physician followed the cystic lesion periodically, by ultrasonography and computed tomography. The cyst on volume did not change, but the thick wall had a tendency to develop to inner space. The patient was referred to our department. Angiography was performed, and it showed neovascularity and tumor staining. We diagnosed the renal tumor in a renal cyst. Transabdominal right radical nephrectomy was performed on 18 June, 1991. The resected specimen involved a mall tumor (2.5 x 2.0 cm) in the cyst. Histological examination of the tumor was renal cell carcinoma which was well capsulated by connective tissue without invasion to normal parenchyma and perirenal fat. We speculated that the renal cell carcinoma originated from the cyst wall and it developed to inner cystic space. The natural history of the renal cell carcinoma in a renal cyst is not clear. Our case shows a type of its history. We reviewed and discussed the types and diagnosis of the renal cell carcinoma in a renal cyst.

Carcinoma, Renal Cell↗
PubMed1991

Change of intracellular calcium of neural cells induced by extracellular ATP.

Exposure of various neural cells to ATP increased intracellular Ca2+ and the production of inositol trisphosphate. The Ca2+ responses were also observed in the absence of extracellular Ca2+, suggesting that a part of Ca2+ mobilization took place from cytosolic storage. Since adenosine had no effect on intracellular Ca2+ increment, ATP appears to act through a P2-purinergic receptor. Islet-activating protein or pertussis toxin pretreatment hardly influenced the increase in intracellular Ca2+ and inositol trisphosphate production induced by ATP, suggesting that IAP-sensitive GTP-binding proteins do not play a practical role in this reaction.

Adenosine↗
PubMed1991

Synthesis and cell attachment activity of bioactive oligopeptides: RGD, RGDS, RGDV, and RGDT.

Tetrapeptides, Arg-Gly-Asp-Ser (RGDS), Arg-Gly-Asp-Val (RGDV), and Arg-Gly-Asp-Thr (RGDT), present in the cell-attachment domain of fibronectin, vitronectin, and collagen, respectively, were synthesized by using an improved liquid-phase procedure. Bioactivities of RGD and RGDX (X = S, V, and T) as cell recognition determinants were investigated by two methods to evaluate interactions of these oligopeptides with L-929 fibroblast cells originating in mouse epithelia. In the first method, these oligopeptides were immobilized to ethylene-acrylic acid copolymer (EAA) film, and the cell-attachment activity of the immobilized film was measured. In the second method, interaction of oligopeptides with the cells was evaluated by measuring the cell inhibition caused by oligopeptides. It was found that RGD and RGDX exhibit remarkable cell-attachment activity, and the activity of oligopeptides depends on X.

Amino Acid Sequence↗
PubMed1991

Two-dimensional polyacrylamide gel electrophoresis of proteins synthesized during early germination of Bacillus subtilis 168 in the presence of actinomycin D.

Two-dimensional gel electrophoresis was used to demonstrate the synthesis of approximately 65 [35S]-methionine-labelled soluble proteins between 0 and 10 min after the start of germination, of approximately 210 proteins at 10-20 min, and of approximately 260 proteins during vegetative growth of Bacillus subtilis. When actinomycin D and [35S]-methionine were administered at the onset of germination and the proteins synthesized during the subsequent 15 min were analyzed, two proteins were detected, and were designated protein I and protein II. Immunoblot analysis with an antiserum raised against RNA polymerase from Escherichia coli demonstrated that protein II corresponded to the sigma A factor of Bacillus subtilis. Thus, the sigma A factor is synthesized during early germination of Bacillus subtilis in the presence of actinomycin D.

Bacillus subtilis↗
PubMed1991

Hydrophobic core of molten-globule state of bovine carbonic anhydrase B.

The interaction which stabilizes the intermediate state of the protein folding and/or unfolding is important for understanding the structure formation mechanism of proteins. The partitioning of a hydrophobic fluorescence probe, pyrene, into the core of a 'molten globule' structure of bovine carbonic anhydrase B was measured, revealing a partition coefficient of about 10(4). The result leads to the conclusion that the compact structure of the molten-globule state is formed by the hydrophobic interaction, as detergent micelles are formed by the same interaction.

Animals↗
PubMed1991

External ATP-induced changes in [Ca2+]i and membrane currents in mammalian atrial myocytes.

Fura-2 fluorescent digital-imaging microscopy and whole cell patch-clamp recordings were used to study the effects of externally applied ATP on atrial myocytes isolated from rabbit and guinea pig hearts. Application of 100 microM ATP elicited a transient increase in intracellular calcium concentration ([Ca2+]i), which was not suppressed by theophylline, whereas adenosine and ADP failed to evoke the response. The Ca2+ transients were suppressed by the application of Co2+, Ni2+, or verapamil and by the removal of extracellular Ca2+, indicating that the inflow of external Ca2+ is necessary to evoke the response. The Ca2+ transient was suppressed also by ryanodine, suggesting that the mobilization of intracellular Ca2+ is another important factor. In the whole cell recordings, ATP induced a transient depolarization of the membrane potential due to the activation of a rapidly desensitizing inward current which persisted in the presence of Co2+, Ni2+, verapamil, or ryanodine. These results indicate that in mammalian atrial myocytes, ATP evoked transient increase in [Ca2+]i via P2-receptor, through the release of internally stored Ca2+ associated with the inflow of external Ca2+. This response seemed to be triggered mainly by the influx of Ca2+ through L-type Ca2+ channel activated by membrane depolarization, which was caused by the ATP-induced inward current.

Adenosine↗
PubMed1991

Serum creatine kinase activities in dogs with dirofilariasis.

Total serum creatine kinase (CK) and its isozyme activities were determined in dogs with dirofilariasis. Before heartworm removal, total CK and isozyme activities in dogs of the mild group were not different from those in dogs of the heartworm-free group. BB activity was higher in dogs of the hemoptysis group. Dogs of the ascites group displayed a mild increase in MM activity. In dogs of the caval syndrome (CS) group, total CK and MM activities were highest among the heartworm-free and heartworm-infected dogs, and MM isozyme accounted for most (75%) of total CK activity. MB and BB activities were also higher. However, there were no significant differences in CK activities between the surviving and non-surviving cases. In dogs with pulmonary heartworm disease (mild and ascites groups), MM activity correlated significantly with the number of heartworms (r = 0.45), hematocrit value (Ht, r = -0.40), serum alanine aminotransferase (ALT, r = 0.42) and lactate dehydrogenase (LDH, r = 0.46) activities, mean pulmonary arterial pressure (r = 0.64) and total pulmonary resistance (r = 0.50). In dogs with CS, MM activity did not correlate with any parameter, but BB activity correlated with the number of heartworms at the right atrium (r = 0.61), Ht (r = -0.53), ALT (r = 0.80), LDH (r = 0.73) and serum urea nitrogen (r = 0.47). At 1 week after heartworm removal, BB and MM activity decreased in dogs of the hemoptysis and ascites groups, respectively. In dogs of the CS group, total CK and MM isozyme activities decreased markedly (P less than 0.01) regardless of their prognosis.

Airway Resistance↗
PubMed1991

Arachidonic acid induced increase in intracellular free calcium in guinea-pig hepatocytes.

Arachidonic acid (AA) caused elevations of intracellular free Ca2+ concentration ([Ca2+]i) measured by fura-2 fluorescence digital imaging microscopy in isolated guinea-pig hepatocytes. AA-induced increase in [Ca2+]i could still be observed when extracellular Ca2+ was chelated by EGTA, and was not influenced by either cyclooxygenase or lipoxygenase inhibitors. These results suggest that AA itself rather than its metabolites has direct effects on intracellular Ca2+ mobilization, causing the elevation of [Ca2+]i.

Adenosine Triphosphate↗
PubMed1990

Inhibition by dexamethasone of histamine production in allergic inflammation in rats.

In an allergic inflammation model of air pouch type in rats, histamine level in the pouch fluid and histidine decarboxylase activity of pouch wall tissues in the postanaphylaxis phase were increased. Although treatment with dexamethasone failed to inhibit histamine release from mast cells in the anaphylaxis phase, histamine production in the postanaphylaxis phase was inhibited dose dependently. Histamine production-increasing activity in the pouch fluid collected 8 h after the Ag challenge, which was estimated by an activity to stimulate histamine production by bone marrow cells, was decreased by the administration of dexamethasone at the time of the Ag challenge. The addition of steroidal antiinflammatory drugs, dexamethasone, prednisolone, or hydrocortisone, into the incubation medium inhibited the pouch fluid-induced histamine production by bone marrow cells. Hydrocortisone mesylate antagonized the inhibitory effect of dexamethasone on histamine production by bone marrow cells. However, hydrocortisone mesylate failed to recover the decrease in histamine production-increasing activity of the pouch fluid collected from dexamethasone-treated rats. In addition, the dialyzed sample of pouch fluid obtained from dexamethasone-treated nonsensitized rats did not reduce the stimulated histamine production by the pouch fluid sample obtained from the sensitized rats. However, increase in histamine production of bone marrow cells stimulated by the pouch fluid was not inhibited by cyclosporin A that inhibited histamine production induced by Con A. This observation indicates that the pouch fluid has no effect to induce production of the histamine production-increasing factor by bone marrow cells. Consequently, it is suggested that dexamethasone inhibits not only the production of histamine production-increasing factor but also the response of histamine-producing cells to this factor.

Animals↗
PubMed1990

Effect of interleukin 1 (IL-1) on the levels of cytochrome P-450 involving IL-1 receptor on the isolated hepatocytes of rat.

In the present study, the expression of IL-1 receptor (IL-1 R) on the primary cultured hepatocytes was determined and the effect of IL-1 on the intracellular amount of cytochrome P-450 was investigated. The kinetics of IL-1R on the hepatocytes was studied by [125I]-IL-1 alpha and revealed that 5,000 molecules of IL-1 bound to a hepatocyte with a Kd of 4.0 x 10(-9) M. Incubation of the hepatocytes with IL-1 for 18 hrs decreased the contents of cytochrome P-450 in a dose-dependent manner. These findings suggest that IL-1 potentially depresses the drug metabolism involving IL-1R which is expressed on hepatocytes.

Animals↗
PubMed1990

Enzyme-catalyzed synthesis of a bioactive oligopeptide in nearly anhydrous solvents with polyethylene glycol-modified proteases.

An oligopeptide, L-arginyl-glycyl-L-aspartyl-L-serine, having cell attachment activity was synthesized from the respective aminoacids carrying suitable protecting residues, by using carboxymethyl polyethylene glycol (PEG)-modified proteases in organic solvents. Papain, trypsin, and alpha-chymotrypsin were modified with PEG. Organic solvents used were 1,1,1-trichloroethane, chloroform and chloroform/ethyl cellosolve (1:1) mixture. Identification of the products was done by gel permeation chromatography (GPC) and thin layer chromatography (TLC).

Amino Acid Sequence↗
PubMed1990

Possible involvement of lymphocyte activating factor (LAF) as an endogenous pyrogen in fever induced by the cell wall skeleton of Nocardia rubra (N-CWS).

We investigated whether interleukin-1 (IL-1) acts as an endogenous pyrogen (EP) on the fever caused by the cell wall skeleton of Nocardia rubra (N-CWS) in guinea pigs. IL-1 activity was expressed as potency of lymphocyte activating factor (LAF). When guinea pig peritoneal macrophages were pulse-stimulated with N-CWS (1-100 micrograms/ml), dose-dependent LAF activity was detected in the supernatants after culture for 4 h. Gel filtration of the culture supernatants on Sephadex G-200 showed that the fractions with LAF activity were not the same as those with cytotoxic activity for L-929 cells, which was measured as an index of tumor necrosis factor (TNF) in parallel with LAF activity. Pyretic activity was detected both in the fractions with LAF activity and in those with cytotoxic activity for L-929 cells. Furthermore, when these macrophages were pulse-stimulated again, this time with the supernatant obtained from macrophages previously pulse-stimulated with N-CWS, LAF and cytotoxic activity for L-929 cells continued to be released from the macrophages. We suggest that IL-1 might be a possible EP in the process of fever elicited by N-CWS, and that such an EP stimulates the macrophages to release further IL-1 or TNF. The resultant long-lasting fever would thus be caused by the continuous release of an EP.

Animals↗
PubMed1990

Contribution of live heartworms harboring in pulmonary arteries to pulmonary hypertension in dogs with dirofilariasis.

To investigate whether adult heartworms harboring in the pulmonary arteries contribute to pulmonary hypertension, we determined the cardio-pulmonary values immediately before and after removal of heartworms from the pulmonary arteries and before and after insertion of live worms in their place. In 10 heartworm-infected dogs, 8 to 46 worms were removed. The mean pulmonary arterial pressure fell significantly from 24.5 +/- 7.9 mmHg to 16.3 +/- 4.9 mmHg (p less than 0.01) immediately after removal. The right cardiac output decreased in 7 of the 10 cases. The total pulmonary resistance and right ventricular stroke work index also decreased. At 24 hours after removal, live heartworms were put back into the pulmonary arteries of their host dog. The mean pulmonary arterial pressure elevated significantly (p less than 0.01) immediately after insertion. The right cardiac output further decreased in 7 of the 10 dogs, and the total pulmonary resistance and right ventricular stroke work index increased. Separate from this, 12 to 42 heartworms were transplanted into the pulmonary arteries of 5 heartworm-free dogs. Immediately after transplantation, the pulmonary arterial pressure did not show any significant change. However, the stroke volume decreased, and the total pulmonary resistance increased. These facts suggest a contribution of live heartworms to the pulmonary hypertension, although there is a complicated interaction among the presence of heartworms, the pulmonary lesions and the pulmonary hypertension.

Animals↗
PubMed1990

[Effect of maxillary protracting bow appliance on reversed occlusion in deciduous dentition].

Previously we investigated the frequency of malocclusion in children who visited the Pedodontic Clinic of Kyushu University and the types of appliances to treat the reversed occlusion in deciduous dentition. The purpose of this study was to evaluate the effects of the maxillary protracting bow appliance to the reversed occlusion in deciduous dentition. Patients at the Hellman's dental age IIA and without molar cross-bite were selected. Eleven patients (6 males and 5 females) were treated with the maxillary protracting bow appliance, and 9 patients (5 males and 4 females) were treated with the chin cap. The controls were 15 patients (5 males and 10 females) without, distal step type of terminal plane, caries and malocclusion. For the sake of evaluation, the study models and lateral cephalograms were analyzed, which were taken before and after the correction of reversed occlusion. The results were as follows: 1. The effects of maxillary protracting bow appliance were the maxillary forward movement associated with counter-clockwise rotation of the nasal floor and the mandibular backward movement associated with clockwise rotation. 2. The maxillary protracting caused the labial inclination of the primary incisors in the maxilla, but the dental arch length was reduced by the mesial movement of the primary second molars in the maxilla. 3. From the results of multiple regression analysis in the maxillary protracting group, it was indicated that the increase of the overjet was attributable to the change of angles of SN-GN, SNB, SNA and GZN.

Cephalometry↗
PubMed1990

[Clinical significance of thrombin-antithrombin III complex and plasmin-alpha 2 plasmin inhibitor complex in chronic liver diseases].

Thrombin-antithrombin III complex (TAT) and Plasmin-alpha 2 plasmin inhibitor complex (PIC) were examined in fifty two cases of various chronic liver diseases. TAT was significantly elevated in cases of hepatocellular carcinoma (HCC), but PIC did not show significant changes in any chronic liver diseases. Elevations of TAT and PIC were seen in cases of HCC accompanied by tumor enlargement and extensive tumor thrombosis. In cases of HCC undergoing transcatheter arterial embolization (TAE), TAT and PIC increased on the next day after TAE, and tended to recover with time, returning to almost normal at fourth week. Prolongation of prothrombin time, elevation of FDP and positive FM test were noted more often in liver cirrhosis with disseminated intravascular coagulation (DIC) than in severe liver dysfunction without DIC. Of five cases confirmed as DIC, only three cases were diagnosed as DIC by DIC score. On the other hand, TAT and PIC were significantly elevated in DIC cases. Especially, TAT exceeded 30 ng/ml in all DIC cases. TAT was regarded to be useful for the diagnosis of DIC in severe liver dysfunction.

Antifibrinolytic Agents↗