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Biomedical subjects

S Horio

Publications and source records attributed to S Horio.

At least 37 records · Page 2Linked to original sources

Seven cases of pelvic exenteration combined with sacral resection for locally recurrent rectal cancer.

Local recurrence of rectal cancer following abdominoperineal resection is rarely amenable to limited resection. Carcinoembryonic antigen assay is valuable for diagnosing most recurrent rectal cancers, but it is inadequate for early detection. Pelvic computed tomography examination is very valuable for the early detection and localization of recurrence in relation to pelvic structures and can also serve as a guide in percutaneous needle biopsy of the tumor. Seven patients with deeply invading recurrent lesions underwent pelvic exenteration combined with sacral resection. The ileal segment conduit was used for ureteral urinary diversion. The mean operation time and blood loss were 8.8 hours and 6,200 ml, respectively. No operative deaths were encountered. One patient is alive 22 months postoperatively with no evidence of disease, and another patient is alive 32 months postoperatively with pelvic wall recurrence. This procedure seems a reasonable treatment for palliation and full recovery in certain patients.

Adult↗

Changes in bronchial reactivity to acetylcholine with type C influenza virus infection in dogs.

To investigate the mechanisms involved in increasing bronchial reactivity, we made a model of airway reactivity increase in dogs after Type C influenza virus infection. Five beagle dogs were inoculated intranasally with the virus, and the time courses of changes in the hemagglutination inhibition (HI) antibody titer and the bronchial reactivity were determined. To assess bronchial reactivity the dogs were anesthetized, and dose-response curves of pulmonary resistance were obtained against increasing concentrations of acetylcholine aerosol. The dogs infected with the virus showed mild symptoms of rhinorrhea and cough. The HI antibody titer was significantly increased in all dogs, with peak values at 1 to 3 wk after infection. The bronchial reactivity to acetylcholine began to increase towards Day 3, reached a peak at 1 to 2 wk, and returned to a normal level at 4 wk. The airway reactivity to acetylcholine at 2 wk after infection was increased by 2.3 to 6.5 times the normal value in terms of the acetylcholine provocative concentration. The mean increase was significant at 1 wk (p less than 0.05), 2 wk (p less than 0.01), and 3 wk (p less than 0.05). Although both the HI antibody titer and the airway responsiveness increased together towards 1 to 2 wk, no close relationship between these factors was observed thereafter. The present dog model of airway hyperreactivity may be useful for further investigation of the mechanism governing increase in bronchial reactivity with respiratory viral infection in normal subjects as well as in patients with asthma.

Acetylcholine↗

Can oligomeric myosin participate in smooth muscle contraction?

An experimental model was constructed to examine the possible fact that myosin oligomers take a part in smooth muscle contraction. Single fibres prepared from glycerinated rabbit skeletal muscle were emptied of myosin and then irrigated with purified chicken gizzard myosin. This was a good preparation in which to see the structural change of gizzard myosin and its interaction with actin filaments under the electron microscope. The structure of gizzard myosin was thoroughly changed by varying the concentration of free Mg2+ in the bathing solution. Myosin thick filaments were formed at the position of the A-band longitudinally bridging adjacent I-segments at high concentration of free Mg2+, while most of them disappeared from the A-band and some localized in the I-segment at low concentration of free Mg2+. When this preparation was induced to contract isometrically, it showed quite different sarcomere patterns at high and low concentrations of free Mg2+. Tensions developed by this preparation were of the same magnitude at high and low concentrations of free Mg2+, which were approximately 5% of that developed by glycerinated skeletal muscle fibres. The shortening of the prepared fibre in a contracting medium was almost the same at varying concentrations of free Mg2+. The relation between the structural organization and the contracting nature of the prepared fibre as the concentration of free Mg2+ was varied is discussed in this paper with respect to the significance of oligomeric myosin in smooth muscle contraction.

Animals↗

Nifedipine inhibits human bronchial smooth muscle contractions induced by leukotrienes C4 and D4, prostaglandin F2 alpha, and potassium.

The effects of nifedipine, a calcium channel blocker, on human bronchial smooth muscle contractions induced by leukotrienes C4 and D4 (LTC4, LTD4), prostaglandin F2 alpha (PGF2 alpha), and potassium were studied in vitro. The LTC4, LTD4, PGF2 alpha, and potassium caused bronchial smooth muscle contractions. After incubation with nifedipine at 2.9 X 10(-6)M, the contractions caused by LTC4, LTD4, PGF2 alpha, and potassium were significantly decreased. Nifedipine also significantly reversed human bronchial smooth muscle contractions previously initiated by these agonists. The effect of nifedipine on potassium contraction was significantly greater than that on LTC4, LTD4, and PGF2 alpha-induced contractions. The pharmacologic feature of nifedipine is that it inhibits the calcium influx associated with membrane depolarization. Therefore, these results suggest that there are two mechanisms of calcium movements in human bronchial smooth muscle contractions induced by LTC4, LTD4, and PGF2 alpha: membrane-depolarization-dependent and -independent mechanisms.

Aged↗

Surface morphology and function of human pulmonary alveolar macrophages from smokers and non-smokers.

Pulmonary alveolar macrophages were obtained by saline lavage from 23 healthy male volunteers--10 non-smokers and 13 cigarette smokers. Lavage produced three times as many alveolar macrophages in smokers than in non-smokers. When macrophages from smokers and from non-smokers were incubated in vitro, more cells from smokers adhered to glass, spread out, and showed enhanced nitroblue tetrazolium (NBT) reduction. The surface morphology of alveolar macrophages from smokers showed more with a plate like appearance and ridge like membrane surface, while the macrophages from non-smokers were predominantly spherical with ruffles. The proportions of cells which stained highly for beta galactosidase were 55% in smokers and 11% in non-smokers. Thus, in a resting state in vitro, alveolar macrophages from smokers were more active than those from non-smokers. When, however, macrophages from smokers and non-smokers were incubated with immunobeads and with opsonised or non-opsonised BCG, the phagocytic activity and stimulated NBT reduction of alveolar macrophages from smokers were similar to or somewhat less than those of non-smokers.

Adult↗

Naturally occurring T lymphocytotoxic antibody in viral and related skin diseases.

The naturally occurring T lymphocytotoxic antibodies in patients with viral and related skin diseases were investigated and compared with those of systemic lupus erythematosus (SLE). The incidences of T lymphocytotoxic antibodies in exanthema suspected of viral infection, infectious mononucleosis, rubella and pityriasis rosea were 28%, 44%, 8% and 28% respectively. Sera from patients with herpes zoster and erythema infectiosum did not show positivity. Incidence in SLE sera as positive control was 82%. The T lymphocytotoxic antibodies detected in skin diseases were similar in nature to those of SLE patients, but were transient and lower in titer than those of SLE.

Antibodies, Viral↗

Preventive and reverse effects of nifedipine on human bronchoconstriction "in vitro".

The effects of nifedipine, a calcium channel blocking agent, on human bronchoconstriction induced by acetylcholine and histamine were studied in vitro. Bronchial preparations were obtained from 13 patients undergoing surgery for bronchial carcinoma. Bronchial strips were mounted for continuous isometric tension recording. Acetylcholine and histamine caused bronchoconstrictions, but the constrictive effects were inhibited by 2.9 X 10(-6) M nifedipine. At a concentration of 2.9 X 10(-6) M nifedipine increased by 22-fold the concentration of acetylcholine required to produce a 50% of maximal contraction of bronchial strips, and by 160-fold the concentration of histamine required. Nifedipine also reversed already established bronchoconstrictions by acetylcholine and histamine. The percentage of contraction at 20 min after 2.9 X 10(-6) M nifedipine was 7 +/- 11.1% (mean +/- SEM) and - 21 +/- 20.0% of the control maximal response by 10(-3) M acetylcholine and 10(-3) M histamine, respectively. Thus, nifedipine clearly prevented and reversed pharmacologically-induced bronchoconstriction in humans. These results suggest that it is valuable to administer nifedipine to prevent and treat asthma attack.

Acetylcholine↗

Anatomically corrected malposition of the great arteries--case reports and a review.

Anatomically corrected malposition of the great arteries (ACM) is an extremely uncommon cardiac disease in which the great arteries arise from their appropriate ventricles despite abnormal spatial interrelations. Two patients with this malformation underwent successful surgical intervention for their associated anomalies. One was of situs solitus, d-loop and l-malposition and the other of situs inversus, l-loop and d-malposition of the great arteries. Fifty-three cases with accurate anatomical description were collected from the literature, and anatomical characteristics and associated anomalies were investigated. From the standpoint of anatomy and hemodynamics, we considered that ACM should be classified into atrioventricular concordant ACM, atrioventricular discordant ACM and ACM with situs ambiguus. Heart position and conus were variable. Dextrocardia and mesocardia were frequent. Bilateral conus was characteristic in concordant ACM, and subpulmonary conus was prominent in discordant ACM. The hypoplasia of the right heart and juxtaposition of the atrial appendages were in high incidence in cases of ACM. Surgical intervention was also discussed.

Angiocardiography↗

The effect of cytochalasin B on the superoxide production by alveolar macrophages obtained from normal rabbit lungs.

Resident alveolar macrophages and lung lavage fluids were obtained from normal rabbit lungs. Superoxide production by alveolar macrophages exposed to lung lavage fluids and cytochalasin B was measured by superoxide dismutase-inhibitable nitroblue tetrazolium (NBT) reduction. Glycogen-elicited peritoneal macrophages were used as a control. Cytochalasin B, as well as lung lavage fluids, enhanced superoxide production by resting alveolar macrophages. The cytochalasin B-induced superoxide production was associated with enhanced attachment to glass and with remarkable alterations of the cell surface morphology, probably relating to interference with the microfilament functions of cells. On the other hand, glycogen-elicited peritoneal macrophages showed only a slight production of superoxide when exposed to the same stimulants.

Animals↗