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Biomedical subjects

K Kawano

Publications and source records attributed to K Kawano.

At least 343 records · Page 19Linked to original sources
PubMed1990

Human liver manganese superoxide dismutase. Purification and crystallization, subunit association and sulfhydryl reactivity.

Manganese superoxide dismutase (Mn-SOD) has been purified with a high yield (320 mg) from human liver (2 kg) and crystallized. Low-angle laser light scattering of the enzyme has shown that native enzyme is a tetrametic form. Four of the eight cysteine residues in the tetramer reacted with 5,5'-dithiobis(2-nitrobenzoic acid) or with iodoacetamide. The others were only reactive in protein heated with SDS or urea after reduction with dithiothreitol or 2-mercaptoethanol. The reactive sulfhydryl group was found to be located at Cys196 by amino acid sequence analysis of Nbs2-reactive peptides isolated by activated thiol-Sepharose covalent chromatography. Incubation of Mn-SOD in 1% SDS for 2 or 3 days at 25 degrees C or 5 min at 100 degrees C gave material showing two prominent components on polyacrylamide gel electrophoresis in the presence of 0.1% SDS. The major component had a molecular mass of 23 kDa; the other, 25 kDa. Reduction of the protein by dithiothreitol or 2-mercaptoethanol heated in SDS produced only the 25-kDa monomer species. Essentially, no thiol groups were detected in the 23-kDa form, in which two cysteine residues appear to have been oxidized to form an intrasubunit disulfide. This indicates that Cys196 has a reactive sulfhydryl and appears to be a likely candidate for a mixed disulfide formation in vivo.

Chromatography, Gel↗
PubMed1990

Antimicrobial peptide, tachyplesin I, isolated from hemocytes of the horseshoe crab (Tachypleus tridentatus). NMR determination of the beta-sheet structure.

The conformation of tachyplesin I, an antimicrobial cationic peptide of 17 residues found in the hemocyte debris of horseshoe crab, was investigated using two-dimensional NMR spectroscopy. The 1H NMR spectrum of tachyplesin I in aqueous solution could be completely assigned, and the secondary structure was substantiated by interpretation of the nuclear Overhauser effect, coupling constant, amide exchange rate, and temperature dependence of the amide chemical shift. Tachyplesin I takes on a fairly rigid conformation constrained by two disulfide bridges and adopts a conformation consisting of an anti-parallel beta-sheet (residues 3-8 and 11-16) connected by a beta-turn (residues 8-11). In this planar conformation, five bulky hydrophobic side groups are localized in one side of the plane and six cationic side groups are distributed at the "tail" part of the molecule (residues 1-5 and 14-17). This amphipathic structure of the molecule is presumed to be closely associated with the bactericidal activity.

Amino Acid Sequence↗
PubMed1990

Alpha 2-adrenoceptor mechanisms in guinea-pig trachea.

In the presence of propranolol tracheal strips from guinea-pigs were markedly contracted by norepinephrine and clonidine but only slightly by phenylephrine. The contractile responses to clonidine and norepinephrine were inhibited by yohimbine but not by prazosin. The specific binding of [3H]p-aminoclonidine to the microsomal fractions from guinea-pig tracheal muscle was much greater than that of [125I]BE2254. These results indicate that alpha 2-adrenoceptors are the predominant subtype of alpha-adrenoceptor in the guinea-pig trachea. The response to norepinephrine was abolished by cyclooxygenase inhibitors, suggesting the release of excitatory prostaglandins by norepinephrine. These results raise the possibility that norepinephrine interacts with alpha 2-adrenoceptors and releases prostaglandins to contract tracheal muscle.

Adrenergic alpha-Antagonists↗
PubMed1990

Expression of human epidermal growth factor and its receptor in esophageal cancer.

The expression of human epidermal growth factor (hEGF) was examined immunohistochemically in 86 esophageal cancer lesions, comprising 67 primary tumors and 19 metastatic lymph nodes. In the normal esophagus, the parabasal and intermediate cell layers showed a weak expression of hEGF, however, hEGF-positive tumor cells were detected in 62 (92.5 per cent) of the 67 primary esophageal carcinomas and in 18 (94.7 per cent) of the 19 metastatic lymph nodes. In this study, the immunoreactivity of hEGF was classified into 4 grades according to the number of stained tumor cells. A significant correlation was observed between the histologic type and the grade of hEGF immunoreactivity (Chi-square test, p less than 0.01). hEGF immunoreactivity in well differentiated squamous cell carcinomas was significantly higher than in other squamous cell carcinomas, although there were no correlations between other pathological findings and hEGF immunoreactivity. Patients with hEGF immunoreactivities of grades II or III had much worse prognoses than those with grades 0 or I (p less than 0.05). In 22 esophageal carcinomas and 10 normal esophageal mucosae, EGF receptor (EGFR) contents were measured by the competitive binding assay. The average EGFR content (101.3 +/- 35.7 fmol/mg protein, mean +/- SE) of the esophageal carcinomas was significantly higher than that (5.3 +/- 1.2) of the normal esophageal mucosae (p less than 0.05). Moreover, in hEGF negative tumors, EGFR contents were lower than in hEGF positive tumors. These results suggest that hEGF and EGFR show increased production in squamous cell carcinomas and could to be useful prognostic factors in patients with esophageal cancer.

Carcinoma, Squamous Cell↗
PubMed1990

Cerebral sparganosis mansoni. Report of two cases.

Among diseases due to cerebral parasitism, that caused by Sparganum mansoni, the larva of Spirometra mansoni, is very rare. We have encountered two such cases. A computed tomography scan in both revealed a nodular high density contrast enhanced area against an extensive low density background area. Neither calcification nor cyst formation was recognized. These computed tomography scan findings were thought to be characteristic for cerebral sparganosis mansoni and were difficult to differentiate from those of a cerebral tumor. In both cases, definitive diagnosis was achieved by identification of the worm after excision of the lesion. The best treatment for cerebral sparganosis mansoni is surgical excision of the lesion, and in the two cases presented the postoperative outcome was good.

Animals↗
PubMed1990

Chemo-radioresistance of small cell lung cancer cell lines derived from untreated primary tumors obtained by diagnostic bronchofiberscopy.

New cell lines of small cell lung cancer (SCLC) were established from specimens of untreated primary tumors biopsied by diagnostic bronchofiberscopy. The advantage of this method was ease of obtaining specimens from lung tumors. Establishment of cell lines was successful with 4 of 13 specimens (30%). Clinical responses of the tumors showed considerable variation, but were well correlated with the in vitro sensitivity of the respective cell lines to chemotherapeutic drugs and irradiation. One of the cell lines was resistant to all drugs tested and irradiation, while another was sensitive to all of them. Although the acquired resistance of SCLC is the biggest problem in treatment, the natural resistance to therapy is another significant problem. Either acquired or natural, resistance mechanisms of SCLC may be elucidated by the use of such cell lines derived from untreated tumors. This method and these SCLC cell lines are expected to be useful for the serial study of biologic and genetic changes of untreated and pre-treated tumors, or primary and secondary tumors.

Animals↗
PubMed1990

Expression of histocompatibility antigen HLA-DR on the epithelial cells of the pancreatic duct and thyroid follicle. An autopsy case.

An autopsy case of chronic pancreatitis associated with unusual chronic thyroiditis in a 54-year-old woman is presented. Microscopically, the pancreas was densely infiltrated by lymphocytes and its exocrine parenchyma was completely replaced by sclerotic tissue. The thyroid gland was also infiltrated by lymphocytes, but no lymphoid follicles were observed. These morphological changes are rare findings with respect to the severity of inflammation and the association of the affected organs. Further findings suggested involvement of an autoimmune mechanism in the pathogenesis of these lesions. Using the avidin-biotin-conjugate technique and antibodies (Abs) against T lymphocyte and HLA-DR antigens (Ags), immunological aspects of the lesions were studied. Most of these infiltrating lymphocytes were revealed to be T lymphocytes, and HLA-DR Ags were observed on the epithelial cells of the pancreatic ducts and thyroid follicles. As a control, 45 surgical specimens of pancreas and thyroid gland were studied for detection of HLA-DR expression on the epithelial cells. One case of chronic pancreatitis was revealed to express HLA-DR Ag on the epithelium. The patient was a 44-year-old woman who had silently developed pancreatic cyst due to chronic inflammation. This finding also suggests a role of autoimmunity in the pathogenesis of chronic idiopathic pancreatitis.

Autopsy↗
PubMed1990

Immunohistochemical localization of c-myc oncogene product and EGF receptor in oral squamous cell carcinoma.

Subcellular distribution of c-myc oncogene product and EGF receptor in oral squamous cell carcinomas was examined by using immunohistochemical method. Immunohistochemy for c-myc oncogene showed three staining patterns. Reactive products were demonstrable in the nucleus, in the perinuclear cytoplasm with granular appearance and in the entire cytoplasm. Concomitant stainings of each reactive pattern were observed. Occasionally, the reactive product was strongly deposited on the chromatin under mitotic phase. EGF receptor positive cases were found in only 4 of 28 cases. Though reactive products were usually found in the cytoplasm, the cell surface staining was detected in the only one case. In this case, cells under mitotic phase were strongly stained. The fact that the strong staining both of c-myc and EGF receptor in cells under mitotic phase suggested the close relation between the expression of these genes and the proliferation of carcinoma cells.

Antibodies, Monoclonal↗
PubMed1990

[Human respiratory tract infection by Pasteurella multocida subsp. multocida presumably derived from the cat].

Pasteurella multocida is a Gram-negative short rod-shaped bacteria that has been recognized as a pathogen of hemorrhagic septicemia and fowl cholera in the veterinary medicine. Infections by this microorganism as seen in the foreign literature vary widely from local infections due to bites and scratches by animals to general infections such as infections of the respiratory tract, sepsis, and meningitis. In Japan, reported cases of P. multocida infections are predominantly local infections, followed by respiratory infection. Recently, death of diabetic patients due to septicemia by this pathogen has also been reported. In this study, we experienced a case of respiratory tract infection in which the pathogen P. multocida subsp. multocida was suggested to have been transmitted from a pet cat by the agreement of the serotype of the bacterial isolates between the patient and the cat. This case was evaluated from the zoonotic viewpoint. The patient was a 68-year-old male who had been followed up since 1982 with a diagnosis of bronchiectasis. After his referral to our hospital, P. multocida subsp. multocida was isolated from his bloody sputum and, then, from the cat kept by the patient. The tow isolates were identical in terms of the biochemical properties, drug susceptibility profile, and serotype (-:1), and the derivation of P. multocida subsp. multocida infection from cat was established for the first time in this report. The incidence of P. multocida infections is increasing in Japan, and particular attention is considered to be needed about these conditions as zoonoses as indicated in "Preventive Measures against Zoonoses Derived from Pet Animals (Dog, Cat)", an official communication from the Ministry of Health and Welfare to related institutions in 1989. Also, to check whether the patient keeps any pet at the clinical inquiry is a practice of bacteriological importance in all fields of medicine.

Aged↗
PubMed1990

[Studies on the giardiasis as the zoonosis].

To obtain basic data on the route of Giardia infection as zoonosis, we examined feces from 80 dogs and 16 cats for Giardia cysts and evaluated the detection rates. In addition, familial infection was studied in 3 family members of the patient with giardiasis. Giardia cysts were detected in 10 of the 80 dogs (12.5%) but none of the cats. Of the 10 dogs from which Giardia cysts were isolated, 6 had been maintained by the breeders. Tow other dogs were for examination in the research institutions. None of the family members of the patient with giardiasis had this infection. Since the detection rates of Giardia cysts in the dogs and cats were low, the possibility that human infection is acquired from dogs or cats seemed to be low. However, some of patients with giardiasis we encountered had never been abroad. This fact together with the presence of Giardia cysts in the dogs despite the low detection rates suggest that attention should be paid to the possible association between human giardiasis and pets since the number of people keeping pets is increasing.

Animals↗
PubMed1990

Evidence that ciclosporin is hepatotoxic and hepatotrophic in 70% hepatectomized rats and mice.

The influence of ciclosporin (Cs) on liver regeneration was studied in rats and mice with or without thymus after two-third hepatectomy. Rats were treated at -24, 0, and +24 h posthepatectomy with oral Cs, 5, 10, or 20 mg/kg. Before hepatectomy, mice were given a 4-day course of Cs 10 mg/kg. The peak mitosis (30 h posthepatectomy) of remnant hepatocytes in rats was doubled by the two lower dosages of Cs but was suppressed by the highest dosage compared with control. In addition, the rise in serum transaminase and total bilirubin concentrations was proportionate to the increase in Cs dosage given. Cs increased hepatocyte division in thymic mice but was hepatotoxic in athymic nude mice. These data present evidence that Cs is both hepatotrophic and hepatotoxic in regenerating liver.

Alanine Transaminase↗
PubMed1990

Effect of aging on the response of guinea pig trachea to isoprenaline.

To study the effect of aging on the beta-adrenergic receptor potency of isoprenaline, tracheas from 3-, 6-, 10-, 40- and 100-week-old guinea pigs were used as test tissues. The pD2 values (potency) of isoprenaline increased with age in tracheas treated with corticosterone, but decreased in untreated tracheas. The pA2 value of propranolol against isoprenaline estimated in the treated tracheas did not change with age. Specific binding of [3H]-dihydroalprenolol to the microsomal fractions from the tracheal muscles from 6-, 10- and 40-week-old guinea pigs was analyzed with Scatchard plots. The capacity of maximum binding sites of [3H]-dihydroalprenolol increased with increasing age, while its dissociation constant did not change. Age-related increase in the potency of isoprenaline in the tracheas treated with corticosterone is considered to be due to the increase in the total amount (density) of beta-adrenoceptors. However, the potency of the drug in untreated tracheas decreased with age. These results suggest that extraneuronal uptake plays an important role in the beta-adrenergic action of isoprenaline in older (40 and 100 weeks) guinea pigs.

Aging↗
PubMed1990

Evidence for release of prostaglandin F2 alpha in contractile response of guinea pig trachea to norepinephrine.

The concentration (10(-8)-10(-5) M)-dependent contractile response of norepinephrine was completely inhibited by cyclooxygenase inhibitors but not by a thromboxane synthetase inhibitor. The amount of prostaglandin F2 alpha was significantly increased in the presence of norepinephrine (10(-5) M). Norepinephrine increased the amount of prostaglandin D2, although not significantly. The norepinephrine-evoked prostaglandin release was inhibited by tolazoline (3 x 10(-5) M). These results suggest that norepinephrine evoked the release of prostaglandins, mainly prostaglandin F2 alpha to induce the contraction of the guinea pig trachea.

Animals↗
PubMed1990

Enhancing effect by heparin on shear-induced platelet aggregation.

We have recently developed a new device for continuously measuring SIPA. Using the device, we have investigated the effects of heparin on SIPA. Heparin itself enhanced SIPA in the absence of agonists in a dose-dependent manner, whereas heparinoids had minimal effects on SIPA. LMW heparin had less enhancing effect on SIPA than unfractionated heparin. Effects of heparin were also investigated using PRP from patients with congenital bleeding disorders, including Bernard-Soulier syndrome, type III von Willebrand's disease, afibrinogenemia and Glanzmann's thrombasthenia. Heparin's effects were observed only when PRP from patients with Bernard-Soulier syndrome and type III von Willebrand's disease was exposed to low shear stress and when PRP from a patient with afibrinogenemia was exposed to high shear stress. These results gave us insights into heparin's effects on platelet aggregation.

Afibrinogenemia↗
PubMed1990

[Genesis and clinical significance of an apical diastolic rumble in patients with mitral Björk-Shiley valve: a Doppler echocardiographic study].

The genesis and clinical significance of an apical diastolic rumble after replacement with mitral Björk-Shiley prosthesis were studied in 20 patients by left ventricular (LV) inflow dynamics using Doppler echocardiography. 1. The rumble was audible in 17 of the 20 patients (85%). In all but one patient, its intensity was less than Levine 2/6. Duration of the rumble ranged from 248 to 544 (mean 377) msec. There was no case of prosthetic valve dysfunction. Duration of the slow filling wave (SF interval) of the apexcardiogram in 19 cases ranged from 150 to 541 (mean 317) msec, and it correlated significantly with the duration of the rumble (r = 0.95) in 15 cases. 2. In 20 patients, peak velocity of the LV inflow obtained from continuous wave Doppler echocardiograms ranged from 1.17 to 1.89 (mean 1.56) m/sec, and pressure half time (PHT) ranged from 82 to 233 (mean 134) msec. In 19 patients, the SF interval correlated significantly with PHT (r = 0.87), but not with peak inflow velocity. 3. Peak inflow velocity was significantly slower in cases without a rumble than in cases with a rumble. PHT and the SF interval tended to be shorter in the former than in the latter. 4. There was no significant difference in the SF interval, peak inflow velocity and PHT between eight patients with smaller valve sizes (less than or equal to 25 mm) and 12 with larger valve sizes (greater than or equal to 27 mm). 5. There was no obvious relation between the direction of the main LV inflow jet as assessed by Doppler color flow mapping and the presence of the rumble in 19 patients. 6. In 19 patients, the SF interval correlated significantly with left atrial dimension (r = 0.47), but it did not correlate with LV end-diastolic dimension, fractional shortening of the LV, and the peak lengthening rate of LV internal dimension. 7. Three patients with both the rumble and SF lasting 500 msec had prolonged PHT longer than 190 msec. One of these three had congestive heart failure and suspected prosthetic mitral valve stenosis. From these results, we concluded that an apical diastolic rumble after replacement with mitral Björk-Shiley valve is mainly due to the increase in resistance and velocity of the LV inflow, and that both durations of the rumble and the SF intervals as well as PHT of the Doppler echocardiogram are useful in detecting stenosis of prosthetic mitral valves.

Adult↗
PubMed1990

[Basic and clinical studies on a new method for detecting anti-Mycoplasma pneumoniae antibody, using high density particles].

We developed a new method for detecting anti-Mycoplasma pneumoniae antibody, using high density particles (HDP). We characterized the HDP, and also studied the clinical applicability of the HDP agglutination method (HDPA). HDP were uniform, spherical particles, having a specific gravity of 2.0 and a mean particle volume of 18 fl. Adsorption of IgG by HDP was approximately 2 times that by polystyrene latex. The sensitized antigen to the HDP, extracted from the Mycoplasma pneumoniae (Mac strain) bound specifically to the anti-Mycoplasma pneumoniae antibody. With HDPA, the antibody was determined within 30 minutes, which was more rapid than with other routine methods such as complement fixation test, passive hemagglutination test and particle agglutination test (PA). HDPA showed excellent correlation with PA. However, the titers with HDPA were generally 2 to 5 tubes higher than that with PA. A follow-up study on 7 cases of mycoplasma pneumonia revealed remarkably high titers of anti-Mycoplasma pneumoniae antibodies in the acute phase of mycoplasma pneumonia by HDPA, compared to that by PA. HDPA is highly sensitive and specific test for detection of anti-Mycoplasma pneumoniae antibody, and useful for rapid diagnosis of mycoplasma pneumonia.

Agglutination Tests↗