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Biomedical subjects

K Ohmori

Publications and source records attributed to K Ohmori.

At least 343 records · Page 19Linked to original sources
PubMed1991

Purification and characterization of a new heat-stable enterotoxin produced by Vibrio cholerae non-O1 serogroup Hakata.

The possible production of a heat-stable enterotoxin (Vc-H-ST) by Vibrio cholerae non-O1 serogroup Hakata was investigated, and the purified Vc-H-ST was characterized. It has a unique amino acid sequence, LIDCCEICCNPACFGCLN. This sequence is quite similar to that of the heat-stable enterotoxin (NAG-ST) produced by V. cholerae non-O1 except for one amino acid (leucine) residue excess at the N terminus. Other characteristics, including biological activity, are compatible with those of NAG-ST.

Amino Acid Sequence↗
PubMed1991

A new series of antiallergic agents. I. Synthesis and activity of 11-(2-aminoethyl)thio-6,11-dihydrodibenz[b,e]oxepin derivatives.

A new series of 11-substituted 6,11-dihydrodibenz[b,e]oxepin derivatives was synthesized and evaluated for antiallergic activity. Convenient methods for the preparation of sulfides from alcohols were developed. Structure-activity relationships are described. Compound 7, 11-[2-(dimethylamin)ethyl]thio-6,11-dihydrodibenz[b,e] oxepin-2-carboxylic acid hydrochloride, was the most potent in the rat passive cutaneous anaphylaxis test (ED50 = 0.92 mg/kg p.o.). It had a potent inhibitory effect on anaphylactic bronchoconstriction in guinea pigs (ED50 = 0.029 mg/kg p.o.) and H1 receptor antagonistic effect (Ki = 14 nM) with few central nervous system side effects. Additionally, an antagonistic effect against prostaglandin D2-induced contraction of isolated guinea pig trachea (pA2 = 5.73) was an attractive mechanism of action of the new antiallergic agent. Compound 7 was selected for further evaluation as KW-4994.

Animals↗
PubMed1991

A new series of antiallergic agents. II. Synthesis and activity of new 6,11-dihydrodibenz[b,e]oxepin-carboxylic acid derivatives.

New methods for the preparation of multi-functionalized-6,11-dihydrodibenz[b,e]oxepins were developed. The structural requirements of KW-4994 (1), a promising orally active antiallergic agent, were defined. A carboxyl group at C-2 was critical for enhanced antiallergic activity of 1. The introduction of bromine atom at C-9 of 1 could elongate the duration of the action of the parent. Antiplatelet activity, a new pharmacological property of this series of compounds, was observed in one of the derivatives of 1.

Animals↗
PubMed1991

[Cefepime in the treatment of patients with surgical infections].

Between March 1988 and June 1990, we gave cefepime to 5 subjects after surgery and studied the pharmacokinetics of the drug. In the same period, we treated 23 patients with surgical infections with the same drug and evaluated its clinical efficacy. In the pharmacokinetic study, 1 g was given intravenously to each individual over a 30 minutes period. The peak levels in the plasma, 59.9-118 micrograms/ml, were obtained at around the end of this time. The peak levels in the bile, 7.1-28.2 micrograms/ml, were reached at 1-5 hours after administration, depending on the patient. At hours 5 and 6, the range of plasma concentration was 3.7-12.3 micrograms/ml. In the 22 patients with surgical infections, clinical efficacy of the drug was excellent in 12, good in 5, fair in 1, and poor in 4, with an overall efficacy rate of 77%. The bacteriological response was evaluated in the 16 patients for whom the species of the probable causative organisms were identified. Those bacteria were eradicated in 10 patients, decreased in 3, and were persisted in 3, with an eradication rate of 63%. Against 5 strains of Escherichia coli isolated, the highest MIC was 0.05 micrograms/ml, and against 2 strains of Pseudomonas aeruginosa isolated, the MIC was 1.56 micrograms/ml, so this drug should be highly effective toward these species. Three strains of Staphylococcus aureus were isolated, one of which was resistant to methicillin. It was not eradicated.

Adolescent↗
PubMed1991

[Imaging of coronary arteries and measurement of coronary flow using transesophageal Doppler echocardiography: a comparison with transthoracic Doppler echocardiography].

Recent advances in Doppler echocardiographic techniques, especially using transesophageal approach, enable us to observe coronary arteries and their blood flow. However, the advantages of transesophageal approach in the evaluation of coronary artery are indistinct. The aim of this study was to examine the ability of transesophageal Doppler echocardiography (TED) and transthoracic Doppler echocardiography (TTD) to visualize coronary artery and measure its flow. The study population consisted of 17 healthy subjects and 41 patients with heart diseases (arrhythmia in 2, valvular disease in 10, ischemic heart disease without complete or subtotal obstruction of coronary artery in 22, congenital heart disease in two, cardiomyopathy in four, and infective endocarditis in one). Thirty subjects were examined by TED, and 44 subjects were examined by TTD. Two patients with complete obstruction of the proximal right coronary artery (RCA), who were not included in the above-mentioned subjects, were examined by TED. The results were as follows: 1) The detection rate of coronary arteries by TED and TTD were: left main trunk (LMT); 96.7/86.4%, left anterior descending artery (LAD) and left circumflex artery (LCx); 83.3/56.8%, and RCA; 63.3/38.6%, respectively. 2) Visible length from the orifice: LMT to LAD; 22.2/30.8 mm, RCA; 20.4/22.3 mm. 3) The detection rate of coronary flow by pulsed Doppler of the two methods: LMT; 66.8/0%, LAD; 70.0/31.8%, LCx; 6.6/0%. RCA; 26.7/0%. 4) Coronary flow was detected by transesophageal two-dimensional Doppler in 73.3% of LMT, 76.6% of LAD, 6.6% LCx and 43.3% of RCA. 5) RCA flow was not detected by transesophageal two-dimensional Doppler in two patients who had complete obstruction of the proximal RCA although RCA near the orifice was obviously imaged by two-dimensional echocardiography. In conclusion, TED had an advantage over TTD in detecting coronary arteries and their blood flow, but TTD had an advantage over TED as to the visible length of coronary artery. When RCA near the orifice was clearly visualized, the absence of RCA flow by TED implied complete obstruction of the proximal RCA.

Arteries↗
PubMed1991

[An evaluation of surgical treatment for giant bullae].

We have experienced 67 operative cases of giant emphysematous bullae of the lung. For the bilateral lesions, two stage operation was performed in five cases and one stage operation under median-sternotomy in 12 cases. Twenty six cases were subjected to Naclerio-Langer's method, 25 cases to partial resection or plication and 15 cases to lobectomy. At the earlier period lobectomy was the treatment of choice, but, recently lobectomy was avoided for the conservation of pulmonary function. In terms of the improvement of pulmonary function, there was no difference between Naclerio-Langer's method and partial resection by Autosuture. In conclusion, for the treatment of giant bullae, partial resection by Autosuture is preferable because of improvement of pulmonary function and one stage median-sternotomy for bilateral lesions also are effective.

Adult↗
PubMed1991

Segmental osteotomy of the upper and lower jaw.

A condition of bimaxillary protrusion can be located among a kind of inferiority complex of Japanese. This article describes a choice of methods for correction of this condition. Segmental osteotomy can correct bimaxillary protrusion that can not be camouflaged by augmentation of the nose or menton.

Asian People↗
PubMed1991

[A case of cystic hygroma of the chest wall].

Hygroma is generally regarded as a benign tumor occurring favoritely in the cervical region of a child. Recently we have experienced a case of hygroma which was initially detected as a right chest wall tumor in a 16-year-old man, then was surgically diagnosed as cystic hygroma; chest roentgenography on a check up examination in his senior high school pointed out some anomaly, leading to his hospitalization. On admission, he had no subjective symptom, but chest roentgenography and CT confirmed an abnormal shadow in the right pulmonary area and a tumor with calcification on the right chest wall, respectively, so he was operated on for excisional biopsy. The tumor was extirpated together with the 7th intercostal muscle adhered to the tumor, and postoperative pathohistological examination led to diagnosis as cystic hygroma. Cystic hygroma of the chest wall is so rare that we would like to report this case, together with some addition consideration of related literature.

Adolescent↗
PubMed1990

High idiotypic connectivity of the VH7183-encoded antibodies directed to a murine embryonic carbohydrate antigen, Lewis Y, as ascertained by syngenic anti-idiotype monoclonal antibodies.

The Lewis Y Ag is a carbohydrate Ag which is closely related to a well-known murine embryonic Ag, the stage-specific embryonic Ag-1 (SSEA-1), in its biochemical structure. It is expressed at the surface of murine embryonic cells as well as many murine cancer cells. For the analysis of idiotopes carried by the anti-Lewis Y antibodies, we generated two syngenic anti-idiotypic mAb, Id-A1 and Id-B4 (both BALB/c IgG1), which are directed to the idiotypic determinants carried by the anti-Lewis Y mAb, AH-6 (BALB/c IgM). Both Id-A1 and Id-B4 (Ab2) recognized paratope-related idiotopes carried by the AH-6 antibody (Ab1); they specifically inhibited the binding of AH-6 to the Lewis Y Ag. The high idiotypic connectivity of anti-Lewis Y antibodies was noted; the polyclonal anti-idiotype antibody, produced in the sera of BALB/c mice by immunizing AH-6 antibody, cross-reacted with several anti-Lewis Y mAb which has been established in different laboratories. Id-B4 and Id-A1 seem to represent such cross-reactive anti-idiotypic antibodies. Id-A1 recognized an idiotope carried by two out of six panel Ab1 mAb directed to the Lewis Y Ag. Id-B4 reacted with four out of the six panel antibodies, and was considered to recognize a recurrent idiotope of anti-Lewis Y antibodies which occurs more commonly than the idiotope recognized by Id-A1. All of the anti-Lewis Y antibodies which carry idiotopes that react with Id-A1 or Id-B4 were encoded by the VH genes of the VH7183 family; the most D-J proximal VH gene family in BALB/c mice, which is known to be preferentially expressed in embryonic B cells. Immunization of BALB/c mice with keyhole limpet hemocyanin-conjugated Id-B4 and/or Id-A1 induced a significant titer of anti-Lewis Y antibodies (Ab1-like Ab3) in the sera.

Animals↗
PubMed1990

Quantitative analysis of antiatherosclerotic effect of nifedipine in cholesterol-fed rabbits.

Reports concerning the effect of slow calcium-channel blockers on experimental atherosclerosis are controversial. We examined the antiatherosclerotic effect of nifedipine (40 mg/day for 16 weeks) on aorta of rabbits on diets containing 0.3%, 0.5%, and 1.0% cholesterol. There were no significant differences in levels of serum lipids with or without nifedipine in the same cholesterol-fed rabbits. The results obtained show that nifedipine suppressed the extent of lipid deposition and surface involvement (S.I.) in aorta in 0.3% cholesterol-fed rabbits, whereas nifedipine only tended to suppress S.I. in 0.5% cholesterol-fed rabbits and had no effect in 1.0% cholesterol-fed rabbits. The log dose-response relationship of S.I. was obtained by plotting the concentration of cholesterol in the feed or the "integrated value" of the total serum cholesterol (TC), i.e., the cumulative sum of the serum TC values obtained at each week. The log dose-response curve was shifted in parallel with the right in nifedipine groups. The Lineweaver-Burk plot constructed from the dose-response curve had the same points crossing the ordinate with or without nifedipine. These results suggested that nifedipine suppressed S.I. in a competitive manner with cholesterol on the specific binding site of lipid deposition. Electron-microscopic findings also demonstrated that fat droplets in smooth muscle cells, extracellular matrix containing collagen, and elastic fibers decreased in nifedipine-treated rabbits.

Animals↗
PubMed1990

Ultrastructural localization of fibronectin and laminin in human granulation tissue in relation to capillary development.

The distribution of fibronectin (FN) and laminin (LM) at developing capillaries during various developmental stages, from capillary sprouts to relatively developed capillaries, was studied by light- and electron-microscopy immunocytochemistry. By light-microscope, FN immunoreactivity was diffusely distributed throughout the stroma of the granulation tissues, while for LM it was preferentially distributed at the perivascular region with the various developmental stages of the immature capillaries. Ultrastructural study revealed that capillary sprouts were closely surrounded by plentiful deposits of immunoreaction with the FN, but only faintly for LM. Relatively developed capillaries with large and tall endothelium were surrounded by plentiful immunoreactive products with both FN and LM, and immunoreactivities in the cisternae of rER of the endothelium and/or the pericytes were also shown. Cytoplasmic interdigitations between the endothelium and the pericyte of developing capillaries were recognized without an immunoreaction for FN and LM. These results mean that the capillary sprouts are associated with a prepatterned FN-rich and LM-poor perivascular matrix, whereas relatively developed capillaries are associated with a FN- and LM-rich perivascular matrix which would have been produced by the capillary endothelium and/or pericytes.

Capillaries↗
PubMed1990

[Intracardiac flow vector measurement by simultaneous dual-frequency two-beam pulsed Doppler echocardiography].

Conventional single-beam pulsed Doppler echocardiography has certain limitations in quantitatively measuring the intracardiac blood flow, because the Doppler incident-angle to the flow stream is uncertain. In the present study, the absolute velocity and direction of the intracardiac blood flow, i.e., flow vector, were measured using our newly-developed dual-frequency two-beam pulsed Doppler echocardiography. This instrument has two transducers with center frequencies of 3.5 MHz (main-beam) and 2.2 MHz (sub-beam) which are linked by two arms. Three potentiometers are set up by the three joints to sense the relative angles. Two velocity components at the intersection of the main- and sub-Doppler beams were measured simultaneously with different directional approaches. The flow vector was calculated manually from the two velocity components. The study population consisted of 18 healthy subjects ranging in age from 23 to 39 years. The left ventricular (LV) inflow vector was measured at the center of the mitral annulus, and the ejection flow vector was measured at the levels of the tip (E1) and the mid-portion (E2) of the anterior mitral leaflet in the LV outflow tract. The results were as follows: 1. The LV rapid inflow (R) was directed slight posteriorly towards the cardiac apex, and its average maximal velocity was 78 +/- 15 cm/sec (mean +/- SD). The LV inflow due to the atrial contraction was directed even more posteriorly than was the R, and its average maximum velocity was 43 +/- 10 cm/sec. 2. The LV ejection flows at E1 and E2 were directed slightly posteriorly rather than parallel to the interventricular septum, and the maximum velocity at E1 and E2 was 53 +/- 20 m/sec and 85 +/- 23 cm/sec, respectively. In conclusion, the dual-frequency two-beam pulsed Doppler technique allows quantitative measurement of the intracardiac blood flow dynamics regardless of the Doppler incident-angle to the flow stream.

Adult↗
PubMed1989

Physical, enzymatic, and contractile properties of brain myosin with anti-brain myosin Fab fragment bound on its tail.

An antibody obtained by immunizing a rabbit with purified bovine brain myosin was found to react with the tail portion of the myosin heavy chain. An Fab fragment obtained by limited papain digestion of the antibody was allowed to bind to brain myosin, and the complex of the Fab fragment and brain myosin (Fab-myosin) was isolated. On examination of the rotary-shadowed Fab-myosin by electron microscopy, most of the Fab fragment was located on the middle to C-terminal regions of the tails of the myosin molecules. The solubility of Fab-myosin in low salt solutions was higher than that of control brain myosin. Fab-myosin was found to form small irregular aggregates in low salt solutions instead of regular bipolar filaments, and the relative population of the monomeric form of myosin molecules observed for the Fab-myosin was much larger than that observed for the control myosin. The actin-activated Mg2+-ATPase activity of Fab-myosin was stimulated two- to threefold by phosphorylation of the light chains with myosin light chain kinase, as observed for the control brain myosin. Furthermore, the levels of the ATPase activity of the phosphorylated and dephosphorylated Fab-myosins were similar to those of the phosphorylated and dephosphorylated control myosins, respectively. The superprecipitation activity of Fab-myosin was also highly dependent on phosphorylation of the light chains. Although control brain myosin formed a large superprecipitate network which contracted to a dense particle, Fab-myosin generated only numerous tiny superprecipitates under the same conditions. From these results it was deduced that a regular filamentous state of brain myosin was not prerequisite for its actin-activated Mg2+-ATPase and superprecipitation activities but was indispensable for the formation of a large and well contractible superprecipitate.

Animals↗
PubMed1989

Critical analysis of extensive cervical laminectomy.

Conventional extensive laminectomy has been widely performed to reduce spinal cord compression, and is greatly facilitated by the use of an air drill. Laminectomy is recognized, however, as the occasional cause of problems after surgery, such as spinal instability or deformity, acceleration of spondylotic change, constriction of the dura mater caused by extradural scar formation, and lack of posterior bony protection for the spinal cord. In an effort to eliminate these negative aspects of conventional laminectomy, a surgical technique called suspension laminotomy has been used. Fifty-five patients treated with conventional extensive laminectomy and 55 others treated with suspension laminotomy were followed up clinically and compared. Flexibility and alignment of the cervical spine were assessed by plane radiographs, and dural configuration by computed tomographic scans. Neurologic improvement was also evaluated. Decrease of spinal movement after laminectomy was observed, notably during extension, probably as a result of functional insufficiency of paraspinal muscles. The incidence of postoperative spinal deformity was lower and the relief of dural constriction better in the patients treated with suspension laminotomy than in those treated with conventional laminectomy. Neurological recovery was significantly better in fully decompressed cases than in insufficiently decompressed cases.

Adult↗
PubMed1989

Redundant nerve roots of the cauda equina: clinical aspects and consideration of pathogenesis.

In order to investigate the clinical significance of redundant nerve roots of the cauda equina (RNR) and their pathogenesis, the following studies were performed: 1) examination of 1,256 myelograms of patients with lumbar disease; 2) clinical analysis of 55 patients with RNR and 75 without RNR; 3) electrophysiological examination of 9 patients with RNR; and 4) anatomical and histopathological examination of 6 autopsy cases. RNR were found in 42% of patients with severely constricted spinal canals. In comparing patients with RNR and those without RNR, RNR were found in older patients, these patients exhibited a longer period from the onset of the symptoms to the time of myelographic manifestation, and they caused more severe signs and symptoms. The spatial distribution of redundant nerve roots and the extent of degeneration of nerve fibers in redundant nerve roots indicated the close causal relationship between RNR and constriction of the spinal canal. As the pathogenesis of RNR, the authors suggest a squeezing force from the constricted spinal canal acting on the nerve roots.

Adolescent↗
PubMed1989

Sialyl SSEA-1 antigen as a carbohydrate marker of human natural killer cells and immature lymphoid cells.

The distribution of a carbohydrate antigen, the sialyl SSEA-1 (sialyl Lex-i), in human lymphoid cells was investigated by flow cytometry with a specific monoclonal antibody, MoAb FH-6. We concluded that the lymphocytes positive for the sialyl SSEA-1 antigen present in normal peripheral blood (PB) are natural killer (NK) cells since the positive cells had an NK activity toward K562 cells, and most of the sialyl SSEA-1+ cells were simultaneously positive for Leu-11 (CD-16) and Leu-19. Essentially, no T and B cells, defined by Leu-4 (CD3) and Leu-16 (CD20), were positive for the sialyl SSEA-1 antigen in PB samples taken from healthy donors and patients with disorders unrelated to lymphoid malignancies. Among the malignant lymphoid cells, many sialylated SSEA-1+ cells were observed in large granular lymphocyte (LGL) leukemia cells and some acute lymphoblastic leukemia (ALL) blasts, but not in CLL cells or malignant lymphoma cells. Sialyl SSEA-1 was also positive in some cultured human lymphoid cell lines. We conclude that expression of the sialyl SSEA-1 antigen is strictly limited to a distinct population of NK cells among the mature lymphocytes in normal PB, but the antigen is present in a wide range of immature lymphoblasts of T- and B-cell lineages as well as the NK-cell lineage. The sialyl SSEA-1 antigen disappears from the surface of immature lymphocytes of T- and B-cell lineages during the course of maturation.

Antibodies, Monoclonal↗