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Biomedical subjects

H Ohkubo

Publications and source records attributed to H Ohkubo.

At least 55 records · Page 3Linked to original sources
PubMed1994

Dermatomyositis with multiple skin ulcers showing vasculitis and membrano-cystic lesion.

A 63-year-old woman with dermatomyositis (DM) developed multiple punched-out ulcers of the skin. She had not only a past history of gastric cancer 10 years prior to the onset of DM, but also a familial history of cancer. A skin biopsy from one of the ulcers revealed both vasculitis and membrano-cystic lesion in the same specimen. She died of interstitial pneumonitis one year after the onset of DM. Vasculitis and membrano-cystic lesion may be an important marker of a poor prognosis in DM.

Dermatomyositis↗
PubMed1994

Comparative clinicopathologic features of early gastric cancer in young and older patients.

BACKGROUND: The clinicopathologic features of advanced gastric cancer have been analyzed in young or older patients; however, with regard to early gastric cancer, it remains unknown whether the features differ between young and older patients. Reported here is an analysis of clinicopathologic characteristics in young and in older patients. METHODS: This study is based on a retrospective review of 25 patients less than 40 years of age with early gastric cancer and of 64 patients more than 70 years of age with early gastric cancer. These patients were treated from 1977 through 1991. RESULTS: Because in the older group there were early double cancers in three patients and quadruple cancers in one, 70 early cancers were present in these 64 patients. Although the young group included a larger percentage of women, the ratio of mucosal cancer to submucosal and the incidence of nodal metastasis did not differ between the groups. Poorly differentiated adenocarcinoma was detected in 13 (52%) of the 25 younger patients, whereas in the older group it was present in 6 cancers (8.6%) alone. The number of metastatic nodes and extent of nodal metastasis were more severe in the young group, but survival rates did not differ between the groups. The depressed type of lesion was present in all patients in the young group, whereas it was only 41 of 70 cancers in the older group. CONCLUSIONS: These findings suggest that early gastric cancer in young adults has aggressive features as based on the histologic pattern, in particular with cancer invasion into the submucosal layer. For these patients nodal extirpation and postoperative adjuvant chemotherapy should be performed in an attempt to prevent lymphatic or hematogenic metastases.

Adult↗
PubMed1993

Combined treatment of pelvic exenterative surgery and intra-operative pelvic hyperthermochemotherapy for locally advanced rectosigmoid cancer: report of a case.

A huge rectosigmoidal cancer which extended into the urinary bladder in a 64-year-old man is herein described. The tumor occupied the pelvic and lower abdominal cavities, while the rectosigmoid was totally obstructed. No hepatic or pulmonary metastasis was evident. The ventral and flank sides of the peritoneum in the right lower abdomen, right common iliac vessels, bilateral ureters, terminal ileum, cecum, ascending colon, and urinary bladder were all directly invaded by the tumor, but the aorta, sacrum, and lower rectum were free of cancer. Consequently, an anterior pelvic exenteration was carried out along with an ileal conduit and a right hemicolectomy. Immediately after the exenteration, intra-pelvic hyperthermochemotherapy was performed using a 46-47 degrees C perfusate containing 40 micrograms/ml of mitomycin C (MMC) and 200 micrograms/ml of cisplatin (CDDP), for 90 min, in an attempt to prevent any further local recurrence. A right hemicolectomy and a permanent colostomy were done simultaneously with the hyperthermia treatment. After an uneventful postoperative course, the patient was prescribed adjuvant chemotherapy, i.e., two administrations of 17 mg/m2 and 21 mg/m2 of MMC, and ten doses of 710 mg/m2 of 5-fluorouracil (5-FU) followed by five doses of 535 mg/m2 of 5-FU. At the time of this writing, the patient is still alive without recurrence at 21 months after surgery.

Adenocarcinoma↗
PubMed1993

Folliculosebaceous cystic hamartoma associated with rosacea.

A case of folliculosebaceous cystic hamartoma associated with rosacea is presented. Clinically, a solid, 5-mm-sized nodule was observed on the nose which showed telangiectasia and a waxy appearance. Histologically, a large horn cyst was located in the dermis, and was continuous with the surface epidermis. It was associated with mature sebaceous glands and immature hair follicles. Folliculosebaceous cystic hamartoma and similar cases have recently been reported, but this is the first report accompanied by rosacea.

Cysts↗
PubMed1993

A new antimicrobial quinolone (AM-1155) analysed in hair as an index of drug exposure and as a time-marker.

Scalp hair samples were obtained at one-month intervals for up to four months after the administration from each of twelve healthy male volunteers participating in a phase I study of a new antimicrobial quinolone, AM-1155, (+/-)-1-cyclopropyl-6-fluoro-1, 4-dihydro-8-methoxy-7-(cis-3,5-dimethyl-1-piperazinyl)-4-oxo-3-quinoline carboxylic acid. After hair was sectioned into 1 cm lengths from the scalp end, corresponding portions from five pieces of hair were dissolved in 1 M NaOH and assessed for AM-1155 by HPLC. In all subjects who had taken a single dose (600 mg, n = 6) or repeated doses (300 mg twice daily for 6.5 days, n = 6), the drug was detected in hair. The hair portions containing the drug were shown in most subjects to move outwards month by month at the rate of about 1 cm month-1. A single hair, which was obtained from each subject of the repeated-dose study 3 months after the completion of administration, was cut into 2.5-mm lengths from the scalp side and analysed for AM-1155. The drug was shown to be contained in 4 to 6 consecutive 2.5-mm lengths, showing that there was no large axial diffusion of the drug along the hair shaft even after 3 months. These findings indicate the utility of measuring this quinolone derivative in hair as an index of drug exposure and, furthermore, as a time marker for analysing other drugs in hair.

Adult↗
PubMed1992

Cytohistologic assessment of antitumor effects of intraperitoneal hyperthermic perfusion with mitomycin C for patients with gastric cancer with peritoneal metastasis.

For 15 patients with refractory gastric cancer and peritoneal metastasis, intraperitoneal hyperthermic perfusion (IPHP) using mitomycin C combined with extensive surgery was prescribed. The antitumor effects were assessed cytohistologically in pre-IPHP and post-IPHP specimens of the abdominal effusion and peritoneal tissue. Gastric cancer cells in the abdominal effusion and/or lavage vanished from post-IPHP peritoneal exudate obtained from the pouch of Douglas. Peritoneal tissues from nine patients were harvested just after the IPHP treatment. All the nuclei of cancer cells were pyknotic in three of nine patients, and two of these three patients are alive with no local recurrence; one patient died of hepatic metastasis. In the remaining six patients, four with preoperative ascitic effusion and positive post-IPHP histologic findings died of peritoneal, intraabdominal, and pericardial metastases. The other two had some residual microscopic foci in the subperitoneal deep layer; one patient died of pleural recurrence, and the other is alive with no evidence of recurrence 42 months after the IPHP. Among the other six patients, whose post-IPHP peritoneal tissues were not available because of disappearance of disseminating foci as a result of the IPHP, two are living with no recurrence and, of the remaining four patients, three died of hepatic and intraabdominal metastases and the other one died of other causes. The histologic findings are suggestive of the following: (1) uniform heat and drug distribution in the abdominal cavity with IPHP treatment, except for an area adjacent to the inflow point of the perfusate; and (2) limited penetration of heat and drug through the subperitoneal layer. Thus, IPHP treatment results in complete destruction of cancer cells in the abdominal effusion and on and just beneath the peritoneum.

Adult↗
PubMed1992

Delineation of structural domains involved in the subtype specificity of tachykinin receptors through chimeric formation of substance P/substance K receptors.

The mammalian tachykinin receptors belong to the family of G protein-coupled receptors and consist of the substance P, substance K and neuromedin K receptors (SPR, SKR and NKR). We constructed 14 chimeric receptors in which seven transmembrane segments were sequentially exchanged between the rat SPR and SKR and examined the subtype specificity of the chimeric receptors by radioligand binding and inositol phosphate measurements after transfection into COS cells. All chimeric receptors showed maximum responses in agonist-induced inositol phosphate stimulation. Detailed analysis of five receptors with agonist selectivity similar to SPR indicated that the selectivity is mainly determined by the region extending from transmembrane segment II to the second extracellular loop together with a minor contribution of the extracellular N-terminal portion. This conclusion was more directly confirmed by an additional chimeric formation in which the introduction of the above middle portion of SPR into the corresponding region of SKR conferred a high affinity binding to substance P. The tachykinin receptors can thus be divided into two functional domains: the region covering transmembrane segments V-VII and responsible for fundamental recognition of the common tachykinin sequence; and its preceding portion involved in evoking subtype specificity by interacting with the divergent sequences of the peptides.

Animals↗
PubMed1992

[Clinical evaluation of cefprozil in children].

Cefprozil (CFPZ, BMY-28100), a new oral cephalosporin, was evaluated for its efficacy and safety in 42 children with bacterial infections (Table 1), and the following results were obtained. 1. CFPZ was administered in 3 or 4 divided doses at daily dosages ranging from 15.3 to 60.0 mg/kg to 42 patients (19 cases of acute tonsillitis and/or laryngitis, pharyngitis, 13 cases of pneumonia, 2 cases each of suppurative cervical lymphadenitis and UTI, and 1 case each of scarlet fever, acute otitis media, suppurative parotitis, impetigo contagiosa, furuncle and acute enteritis) and the following clinical results were obtained: excellent; 24 cases, good; 14 cases, fair; 4 cases. The overall efficacy rate was 90.5% (Table 3). 2. MICs of CFPZ against 50 strains of isolated organisms are shown in Table 4. In 19 cases out of 28 cases examined, causative organisms were successfully eradicated and strain of Staphylococcus aureus was decreased in 1 case. 3. Diarrhea was observed in 2 cases (cases 8, 11). In case 8, the symptom disappeared spontaneously. Case 11 improved immediately after the administration of the drug was stopped. Among 39 children who went through laboratory tests, eosinophilia which seemed to be related to the administration of this drug was observed in 2 cases (cases 29, 38). Slight elevations of S-GOT and S-GPT were found in 1 case (case 22) (Table 7). 4. These data suggest that CFPZ is a safe and useful new antibiotic in the treatment of children with susceptible bacterial infections.

Administration, Oral↗
PubMed1992

Effects of the new antiplatelet agent 2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine on platelet aggregation and thrombosis in experimental animals.

Antiplatelet and antithrombotic effects of KC-764 (2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine, CAS 94457-09-7) were studied. KC-764 inhibited arachidonic acid (AA)- and collagen-induced platelet aggregation with IC50s of 1.0 x 10(-8)-2.8 x 10(-7) mol/l for humans, rabbits, guinea pigs and dogs, and IC50s of 3.9 x 10(-6)-3.7 x 10(-5) mol/l for mice and rats in vitro. KC-764 inhibited AA- and collagen-induced aggregation with ID50s of 0.04-0.09 mg/kg p.o. in rabbits and dogs, and ID50 of 13.0 mg/kg p.o. in rats. These antiaggregatory activities of KC-764 were stronger than those of acetyl-salicylic acid (ASA), indometacin, cilostazol and ticlopidine. KC-764 inhibited the production of thromboxane B2 (TXB2) in rabbit platelet microsomes, washed platelets and reconstituted platelet rich plasma (RPRP) with IC50s of 2.9 x 10(-6) mol/l, 2.8 x 10(-7) mol/l and 4.3 x 10(-8) mol/l, respectively. The in vitro inhibitory activity of KC-764 on AA-induced platelet aggregation was more potent when RPRP was used rather than washed platelet suspension containing 30% rabbit plasma. ASA did not show such an augmentation. KC-764 prevented collagen- and AA-induced thrombosis at more than 1 mg/kg p.o. and more than 0.1 mg/kg i.v. in mice and rabbits. KC-764 showed the wider margin of dose between antiplatelet action and prolongation of bleeding time in rabbits than ASA and indometacin. These results indicated that KC-764 was a potent antithrombotic drug to prevent TXB2 production and less possible to induce untoward actions as compared with ASA or indometacin.

Adenosine Diphosphate↗
PubMed1992

Protective effect of the new antiplatelet agent 2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine on myocardial damage due to coronary occlusion and reperfusion in rabbit.

The effects of KC-764 (2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine, CAS 94457-09-7) on infarct size, myeloperoxidase (MPO) activity and plasma prostanoid levels were studied using coronary artery occlusion (1 h)-reperfusion (3 h) model in rabbits, comparing with acetylsalicylic acid (ASA). Myocardial infarct size, MPO activity in the infarcted region and plasma glutamate oxalo-acetate transaminase, lactate dehydrogenase and creatine kinase were significantly suppressed by treatment with KC-764 (2 mg/kg i.v.), but not by ASA (10 mg/kg i.v.). KC-764 completely depressed the increase in plasma TXB2 level during occlusion-reperfusion with a little influence on plasma 6-keto-PGF1 alpha. Thus, the ratio of 6-keto-PGF1 alpha to TXB2 levels was increased by KC-764. On the other hand, ASA treatment depressed both plasma TXB2 and 6-keto-PGF1 alpha levels to the same extent. The in vitro study with guinea-pig neutrophils showed that KC-764 reduced the chemotaxis induced by formyl-methionyl-leucyl- phenylalanine at 3 x 10(7)-3 x 10(-6) mol/l, while ASA did not influence the neutrophil chemotaxis. These results suggest that KC-764 may salvage the damaged ischemic myocardium by the selective inhibition of TXA2 synthesis and the suppression of leukocyte migration.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Antiplatelet effects of 2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine in relation to its disposition in rats, rabbits and dogs.

KC-764 (2-methyl-3-(1,4,5,6-tetrahydronicotinoyl)pyrazolo[1,5-a]pyridine, CAS 94457-09-7) was evaluated for the inhibition of platelet aggregation and prostanoid production in rats, rabbits and dogs, comparing with acetylsalicylic acid (ASA). Correlations between the inhibitory action and plasma concentration of KC-764 were examined in rabbits. KC-764 was 200 times more potent than ASA in inhibiting collagen-induced rabbit platelet aggregation and TXA2 production in vitro. KC-764 exhibited more selective inhibition of TXA2 production over PGI2 production than ASA. The ratio of IC50's of PGI2 production to TXA2 production of KC-764 was 175 in rats, 72 in rabbits and 65 in dogs, respectively. Such a selectivity was also confirmed ex vivo. The depression of plasma TXB2 levels was well correlated with the ex vivo antiaggregatory activity in rabbits at oral doses of KC-764 ranging from 0.02-1.5 mg/kg. The concentrations/in vitro inhibitory activity relationship was expressed by a sigmoid Imax model equation. The ex vivo antiplatelet activity and prostanoid production were reconstructed with Imax model equation using the simulated plasma drug concentrations and in vitro Imax model parameters in all animals. The relationship could be applied for the prediction of the inhibitory activity of KC-764 in humans. These results indicate that KC-764 is a potent, selective and reversible antiplatelet drug, being different from ASA.

Animals↗
PubMed1991

Expression of bovine lung prostaglandin F synthase in Escherichia coli.

The full-length bovine lung prostaglandin(PG) F synthase cDNA was constructed from partial cDNA clones and ligated into bacterial expression vector pUC8 to develop expression plasmid pUCPF1. This plasmid permitted the synthesis of bovine lung PGF synthase in Escherichia coli. The recombinant bacteria overproduced a 36-KDa protein that was recognized by anti-PGF synthase antibody, and the expressed protein was purified to apparent homogeneity. The expressed protein reduced not only carbonyl compounds including PGD2 and phenanthrenequinone but also PGH2; and the Km values for phenanthrenequinone, PGD2, and PGH2 of the expressed protein were 0.1, 100, and 8 microM, respectively, which are the same as those of the bovine lung PGF synthase. The protein produced PGF2 alpha from PGH2, and 9 alpha, 11 beta-PGF2 from PGD2 at different active sites. Moreover, the structure of the purified protein from Escherichia coli was essentially identical to that of the native enzyme in terms of C-terminal sequence, sulfhydryl groups, and CD spectra except that the nine amino acids provided by the lac Z' gene of the vector were fused to the N-terminus. These results indicate that the expressed protein is essentially identical to bovine lung PGF synthase. We confirmed that PGF synthase is a dual function enzyme catalyzing the reduction of PGH2 and PGD2 on a single enzyme and that it has one binding site for NADPH.

Amino Acid Sequence↗
PubMed1991

Alteration of channel activities and gating by mutations of slow ISK potassium channel.

ISK is a small membrane protein consisting of 129-130 amino acid residues with a single putative transmembrane domain and induces a very slow voltage-dependent K+ channel activity in the Xenopus oocyte expression system. We investigated the nature and structure-function relation of ISK by examining the effects of various mutations of ISK on the K+ channel activities measured in Xenopus oocytes. Deletion and truncation of the ISK protein indicated that the 63-amino acid sequence covering a transmembrane domain is sufficient for eliciting a K+ channel activity characteristic of ISK. Amino acid substitutions at a total of 31 positions within and surrounding the transmembrane domain caused different effects on the channel activity. A channel activity was enhanced by substitution of leucine with isoleucine at position 52 within the transmembrane domain, and the kinetic analysis of this mutation indicated that the enhancement of the channel activity is due to an alteration of a gating property of the ISK protein and thus supported the view that ISK forms an integral part of the K+ channel itself. The substitutions at many positions of the membrane-following region produced drastic reduction of the channel activity, and this is in marked contrast to the lack of effects of amino acid substitutions at the membrane-preceding region. Thus, the cytoplasmic portion immediately following the transmembrane domain plays a crucial role in inducing the channel activity of ISK.

Amino Acid Sequence↗