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Biomedical subjects

M Kitano

Publications and source records attributed to M Kitano.

At least 127 records · Page 7Linked to original sources
PubMed1995

Molecular analysis of extracellular-superoxide dismutase gene associated with high level in serum.

Extracellular-superoxide dismutase (EC-SOD) is one of the SOD isozymes mainly distributed in the extracellular fluid. In the vascular system, it is located on the endothelial cell surface according to studies on the heparin binding capacity. By measurement of serum EC-SOD levels of Japanese in healthy persons (n = 103) and hemodialysis patients (n = 150), 7 healthy subjects and 24 hemodialysis patients were classified into group II associated with high EC-SOD levels. By molecular analysis of the EC-SOD coding region from the group II individuals in Sweden, a single nucleotide substitution of G to C generating an amino acid change of arginine to glycine has been identified in the region associated with the heparin affinity of the enzyme. The same mutation was detected in the Japanese as a homozygote in both alleles of 2 hemodialysis patients and as a heterozygote in one allele of all the healthy group II individuals and 17 hemodialysis patients. The amino acid substitution may result in the decrease of the heparin affinity which is favorable for the existence of EC-SOD in the serum.

Amino Acid Sequence↗
PubMed1995

Systemic artery-to-pulmonary artery shunt after using an omental pedicle flap.

A 66-year-old man was hospitalized because of hemoptysis. Four years earlier, he had undergone an operation involving the use of an omental pedicle flap that was supplied by the right gastroepiploic artery for the treatment of empyema. Arteriography revealed that the right gastroepiploic artery communicated with the periphery of the right pulmonary artery. The right gastroepiploic artery was divided surgically.

Abdominal Muscles↗
PubMed1995

Right ventricular function evaluated by volumetric analysis during left heart bypass in a canine model of postischemic cardiac dysfunction.

Right ventricular function during left heart bypass was evaluated by volumetric analysis with a conductance catheter in 12 dogs with postischemic cardiac dysfunction. The conductance catheter was used to assess the volumetric status of the right ventricle and thereby allowed a right ventricular pressure-volume curve to be obtained, in which transient volume loading on the right ventricle was applied. The following right ventricular properties during left heart bypass were assessed and compared with properties measured without left heart bypass, by means of load-independent parameters: maximum elastance, stroke work/end-diastolic volume relation, end-diastolic pressure/volume relation, and stroke work/end-diastolic pressure relation. The stroke volume derived from the conductance catheter and the electromagnetic flow probe showed good linear correlation (r2 = 0.733 to 0.975). After initiation of left heart bypass, maximum elastance did not change significantly, although volume intercept significantly increased, from 1.2 +/- 7.3 to 3.6 +/- 7.9 ml (p < 0.05). End-diastolic pressure/volume relation was well fitted to the exponential curve (EDP = e(k1.EDV+k2)) and was shifted to the right and downward during left heart bypass; the slope k1 significantly decreased, from 0.12 +/- 0.06 to 0.10 +/- 0.07 (p < 0.01). Stroke work/end-diastolic volume relation and stroke work/end-diastolic pressure relation were closely fitted to the linear regression, and their slopes were significantly increased during left heart bypass, from 0.14 +/- 0.08 to 0.18 +/- 0.08 (p < 0.05) and from 0.22 +/- 0.15 to 0.34 +/- 0.19 (p < 0.01), respectively. These results suggest that the decompression of the left ventricle and septal shifting by left heart bypass provide good diastolic compliance and good systolic performance because of afterload unloading of the right ventricle. Thus the left heart bypass improved the overall right ventricular performance, particularly at higher end-diastolic pressures, in dogs with postischemic cardiac dysfunction.

Animals↗
PubMed1995

Bacterial invasion into dentinal tubules of human vital and nonvital teeth.

The difference in resistance to bacterial invasion into the dentinal tubules between vital and nonvital teeth has not been determined. This study was conducted to clarify the effect of vital pulp on bacterial invasion into the dentinal tubules. The specimens were 19 intact pairs of bilateral upper third molars of 19 healthy, young adult male volunteers. In each case, 30 or 150 days before extraction, pulpectomies and root canal fillings were carried out unilaterally and a class V cavity involving the dentin was made on the palatal surface of both the pulpectomized tooth and the nonpulpectomized opposite tooth. The cavities were left unprotected to expose them to oral flora until the extractions were done, and the extracted teeth were examined histologically. When extraction followed 150-day exposure to the oral flora, there was a statistically significant difference in the bacterial invasion rate between the vital and nonvital teeth. It was postulated that vital teeth were much more resistant to bacterial invasion into the dentinal tubules than were nonvital teeth, thereby suggesting that the vital pulp plays some important role in this process.

Adult↗
PubMed1995

Inhibition of intestinal tumor development in rat multi-organ carcinogenesis and aberrant crypt foci in rat colon carcinogenesis by 22-oxa-calcitriol, a synthetic analogue of 1 alpha, 25-dihydroxyvitamin D3.

The modifying effects of 22-oxa-calcitriol (OCT), a synthetic analog of 1 alpha,25-dihydroxyvitamin D3, were assessed in a multi-organ carcinogenesis model using male F344 rats initially treated with five kinds of carcinogens. In experiment 1 the rats were given OCT intraperitoneally at doses of 30 micrograms/kg (25 rats) or 3 micrograms/kg (25 rats), three times a week for 24 weeks after initial carcinogen exposure over 4 weeks and a 2 week non-treatment period. Twenty-two rats received the five carcinogens and were given the vehicle intraperitoneally as a control. A further group of 10 rats was given the 30 micrograms/kg dose of OCT without prior carcinogen application. At the end of the total observation period of 30 weeks the carcinoma incidence in the small intestine of rats given 30 micrograms/kg OCT after carcinogen treatment was 0%. This incidence was significantly smaller when compared with the control group. The incidence of large intestine carcinomas in the 30 micrograms/kg OCT group showed a tendency to decrease. The numbers of small and large intestinal carcinomas per rat were also significantly lower in the group given 30 micrograms/kg OCT than after 3 micrograms/kg OCT or carcinogens alone. Attention was, therefore, focused on colon carcinogenesis and in experiment 2 30 micrograms/kg OCT administered six times a week to rats for 8 weeks after the last injection of N,N'-dimethylhydrazine (DMH) exposure. OCT significantly reduced the formation of DMH-induced aberrant crypt foci, considered to be putative preneoplastic lesions. In experiment 3 30 micrograms/kg OCT was administered six times a week to rats for 4 weeks without prior carcinogen treatment. The proliferating cell nuclear antigen labeling index for the colonic epithelium of rats given 30 micrograms/kg OCT was decreased. Ornithine decarboxylase and spermidine/spermine N1-acetyltransferase activities in colonic epithelium, assayed as indicators of cell proliferation, were not significantly decreased as compared with control group values. Furthermore, vitamin D receptors in colonic epithelium were not significantly increased. Thus the present study indicates that OCT can exert inhibitory effects on tumor development in the small and large intestines, although the mechanism is unclear.

Acetyltransferases↗
PubMed1995

Lack of promoting effects of alpha-linolenic, linoleic or palmitic acid on urinary bladder carcinogenesis in rats.

Potential promoting effects of alpha-linolenic, linoleic and palmitic acids were investigated in a two-stage urinary bladder carcinogenesis model. In experiment 1, male F344 rats were given 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) in their drinking water for 4 weeks and then basal diet containing 10% alpha-linolenic, 10% linoleic or 10% palmitic acid along with 0.2% butylated hydroxyanisole (BHA) as an antioxidant for 24 weeks. The development of tumors in the urinary bladder was not increased by treatment with any of the fatty acids. In experiment 2, male F344 rats were given 10% alpha-linolenic, 10% linoleic or 10% palmitic acid along with 0.2% BHA in their diet for 8 weeks without prior BBN treatment. The administration of fatty acids was not associated with any increase in the 5-bromo-2'-deoxyuridine labeling index of the urinary bladder epithelium. Serum and/or urine fatty acid levels increased in the cases of alpha-linolenic and linoleic acid treatments, but not with palmitic acid. Under the present experimental conditions neither the two polyunsaturated nor the one saturated fatty acid exerted any promoting effect on urinary bladder carcinogenesis.

Animals↗
PubMed1995

Modification of delayed-type hypersensitivity reactions by muramyldipeptide in guinea pigs.

N-Acetylmuramyl-L-alanyl-D-isoglutamine (muramyldipeptide, MDP) modulated delayed-type hypersensitivity (DTH) reactions and induced severe inflammatory lesions in guinea pigs. The animals immunized with heat-killed Mycobacterium tuberculosis were challenged with the purified protein derivative (PPD) at the flanks and the corneas to prepare DTH reactions at 2 weeks after the immunization, thereafter 24 h the animals received subcutaneous injections of MDP at the flanks of the opposite side. At the skin with the DTH reaction, increase of swelling and redness accompanied with hemorrhage and necrosis were observed. As corneal reactions in the animals that had received MDP, increase of cornea thickness, opaque and grayish-white and the projection of eyes accompanied with severe iritis were observed. Modification of the skin reaction occurred from 2 h after the MDP injection, rapidly increased to the maximum level around 10 h, maintained the level until 24 h, then slowly decreased. The polymorphonuclear leukocyte infiltration was observed from 15 min after the MDP injection, and tumour necrosis factor alpha, interleukin (IL)-1, and IL-6 levels in the serum and skin lesions increased after the MDP injection. Synthetic muramyltripeptide (N-acetylmuramyl-L-alanyl-D-isoglutaminyl-L-lysine) also provoked definite skin reactions, while the larger peptidoglycan fragments and various inflammatory agents including cytokines so far examined were inactive in this respect. Cortisone and heparin inhibited definitely and slightly the reaction, respectively. A comparison was made with the modified DTH reaction and the necrotic reactions which we reported previously.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1995

Studies on pyridonecarboxylic acids. IV. Synthesis and antibacterial activity evaluation of S-(-)- and R-(+)-6-fluoro-1-methyl-4-oxo-7- (1-piperazinyl)-4H-[1,3] thiazeto[3,2-a]quinoline-3-carboxylic acids.

Optically active isomers of 6-fluoro-1-methyl-4-oxo-7-(1-piperazinyl)-4H- [1,3] thiazeto [3,2-alpha] quinoline-3- carboxylic acid (NM394, 3) were prepared through optical resolution of their racemic intermediate ( +/- )-1 by high-performance liquid chromatography (HPLC). The absolute configuration at the C-1 position in the thiazeto-quinolone ring of ( - )-3 was confirmed by X-ray analysis ( - )-4 to be S. The in vitro antibacterial activity of ( - )-3 was 2--8 times that of (+)-3.

Anti-Infective Agents↗
PubMed1995

Studies on pyridonecarboxylic acids. III. Synthesis and antibacterial activity evaluation of 1,8-disubstituted 6-fluoro-4-oxo-7-piperazinyl-4H-[1,3]thiazeto[3,2- a]quinoline-3-carboxylic acid derivatives.

A series of 1,8-disubstituted 6-fluoro-4-oxo-7-piperazinyl-4H-[1,3]thiazeto[3,2-a]quinoline-3- carboxylic acid derivatives was prepared and evaluated for antibacterial activity. In the 7-piperazinyl series, addition of a fluorine at C-8, which increased the in vitro activity for the 1-hydrogen and 1-methyl analogues and decreased it for the 1-phenyl analogue, improved the in vivo activity of all the analogues. Introduction of a methoxy group at C-8 of the 1-methyl-7-piperazinyl analogue also improved its in vivo antibacterial activity. The effect of 8-substituents on the in vitro and in vivo antibacterial activity of the 1-methyl-7-(4-methyl-1-piperazinyl) series is also discussed.

Animals↗
PubMed1995

Serum insulin-like growth factor-I (IGF-I) in normal Japanese adults.

To evaluate surgical and medical treatment of GH-producing pituitary tumors and GH supplement to GH-deficient patients, we determined the reference values for serum IGF-I in Japanese adults. The serum IGF-I concentration in 454 apparently healthy subjects (246 men aged 21-70 years and 208 women aged 21-72 years) was measured with a commercial RIA kit after acid-ethanol extraction. The concentration of serum IGF-I decreased with age in both sexes. The IGF-I in females was significantly higher than that in males in the group aged 21-30 years and lower in the group aged 61-72 years. We conclude that an age- or sex-related standard is necessary for comparing IGF-I values in patients.

Adult↗
PubMed1995

Plasma exchange in chronic inflammatory demyelinating polyradiculoneuropathy; different beneficial effects and their correlation to the clinical features.

We report 7 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) who showed significant clinical improvement by plasma exchange (PE). Their clinical features were extensively varied but fulfilled the diagnostic criteria for CIDP. The patients could be divided into 2 subgroups based on the mode of effectiveness of PE; one group consisted of those who once achieved complete remission, but required highly frequent PEs for long-term maintenance of remission and the others were those who showed persistent and complete remission with several sessions of PE alone. These findings raise issues about the long-term therapeutic goals to be achieved by PE for CIDP patients, particularly on supportive therapy other than PE, as well as the optimization of frequency and duration of PE.

Adult↗
PubMed1995

[Female lung cancer].

One hundred and ninety one women were diagnosed with lung cancer at our hospital. This comprised 23.7% of all lung cancer cases. Smoking habits were significantly lower in female lung cancer. Adenocarcinoma is the most common histological type of female lung cancer (64.2%). The prognoses of asymptomatic cases detected by regular examination were significantly better than those of symptomatic cases. Among resectable cases of either adenocarcinoma or squamous cell carcinoma, there were no significant differences between the prognosis for women and that for men. However, the prognosis for nonresectable cases of adenocarcinoma in women was significantly better in the 2-year survival rate (30.8%) than the prognosis for such cases in men. Since the periphery type is the most common site of adenocarcinoma in women, educating women, especially those in the high-risk group, and persuading them to undergo regular examinations are important step to increasing early-stage detection and cure.

Adenocarcinoma↗
PubMed1995

[Characteristics of early carcinomas and precancerous lesions in the urinary bladder].

Early transitional cell carcinomas of the urinary bladder are morphologically classified into papillary and non-papillary types, carcinoma in situ (CIS). Severe dysplasia is considered as a precancerous lesion for CIS which can be distinguished from the morphological appearance of its AgNORs. The conversion from severe dysplasia to CIS appears to require a longer time than that needed for invasive lesion to develop from CIS. It is postulated that mild or moderate dysplasia results in G1 and 2 grade papillary transitional cell carcinomas. Molecular analysis of different types of dysplasia is therefore clearly warranted to assist in diagnostic classification.

Animals↗
PubMed1995

Observation of ZnO particles grown by electrochemical reaction of Zn.

The electrochemical reaction of Zn is investigated by scanning electron microscopy and transmission electron microscopy. Zn films are used as anodes, loaded at DC voltages of 10-200 V in distilled water at 20 degrees C. Zn ions diffuse from the anode and are coupled with OH ions to form spindle-like ZnO particles of 1-2 microns on the cathode or on a permeable paper barrier placed between the anode and cathode. Formless layers, which are composed of fine ZnO crystallites of several nanometers or less in size, form on the cathode in the water at lower OH ion density before the growth of the spindles. They become spindle-shaped after only a few minutes of water bath treatment at 60 degrees C.

Electrochemistry↗
PubMed1995

Cross-sectional transmission electron microscopy of ZnO tetrapod-like particles.

ZnO tetrapod-like particles having legs as long as several tens of micrometers have been observed by cross-sectional electron microscopy. The specimen is prepared by a new method where a photo-resist suspension of the particles fills up holes of an electron microscopy grid and is solidified for the subsequent ion-milling. Electron diffraction and high-resolution electron microscopy of a section of a ZnO tetrapod reveal the orientation relationship among its four legs, which enables us to discuss on the growth mechanism of these particles.

Microscopy, Electron↗
PubMed1994

Clinical significance of plasma endothelin-1 in patients with chronic liver disease.

To determine the clinical significance of plasma endothelin-1 in chronic liver disease, these levels were measured by radioimmunoassay. The plasma endothelin-1 levels in patients with cirrhosis (N = 16) (2.04 +/- 0.25 pg/ml) and patients with hepatocellular carcinoma (N = 22) (2.23 +/- 0.17 pg/ml) increased significantly compared with controls (N = 16) (1.17 +/- 0.17 pg/ml) and patients with chronic hepatitis (N = 11) (1.09 +/- 0.19 pg/ml) (P < 0.01). The presence of ascites rather than tumor volume was associated with a significant elevation of endothelin-1. Endothelin-1 showed significant negative correlations with parameters of hepatic function, including indocyanine green clearance, serum albumin, and prothrombin time. Although endothelin-1 was not correlated with plasma renin activity and plasma endotoxin, it demonstrated a significant positive correlation with the plasma level of atrial natriuretic peptide (r = 0.42, P < 0.01). These findings demonstrate that plasma endothelin-1 increased in proportion to the severity of liver damage and may be causally related with the derangement of systemic/renal hemodynamics and fluid and electrolyte homeostasis seen in advanced liver disease.

Atrial Natriuretic Factor↗
PubMed1994

Pigmented ameloblastic fibro-odontoma with melanophages.

A case of pigmented ameloblastic fibro-odontoma in the mandible of a 9-year-old Japanese girl is reported. In this tumor, melanin was widely distributed in the nests of the odontogenic epithelial component, and an aggregation of large round melanophages with a large amount of melanin similar to nevus cells was observed in the areas of the connective tissue component. A considerable number of dendritic cells that were considered to be melanocytes were scattered in the epithelial nests. This is the first case of pigmented odontogenic tumor that showed such extensive pigmentation with an aggregation of melanophages.

Child↗