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Biomedical subjects

A Mizuno

Publications and source records attributed to A Mizuno.

At least 145 records · Page 8Linked to original sources
PubMed1994

Analysis of a new fluoroquinolone derivative (Q-35) in human scalp hair as an index of drug exposure and as a time marker in hair.

Scalp hair samples were obtained every month for three months after administration from healthy male volunteers who participated in the phase I study of a new antimicrobial fluoroquinolone derivative (Q-35). Hairs were cut into 1 cm long pieces successively from the scalp end. Corresponding pieces of 5 hair strands were dissolved in 1 M NaOH and assessed for Q-35 by HPLC. The drug was detectable in the hairs of all subjects taking either a single (400 mg, n = 6) or repeated oral doses of Q-35 (400 mg/day for 6.5 days, total 2600 mg, n = 6). The hair portions containing the drug were shown in most subjects to move outwards along the hair shafts month by month in proportion to the hair growth rate of about 1 cm/month. Q-35 (600 mg/day) was also given to 6 healthy male volunteers for 6.5 days (total 3900 mg) and hair samples were obtained 1 and 3 months after administration. When Q-35 was analyzed along a single hair shaft, the drug was detectable only in 1-2 consecutive 1 cm long pieces, which were also shown to move outwards along the hair shaft with time. A detailed analysis revealed that the drug was contained only in 2-4 consecutive 2.5 mm long pieces of a single hair collected after 3 months, showing that there was no significant axial diffusion of the drug along the hair shaft with time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Sexual difference in the incidence of diabetes mellitus in Otsuka-Long-Evans-Tokushima-Fatty rats: effects of castration and sex hormone replacement on its incidence.

The incidence of non-insulin-dependent diabetes mellitus in a model rat (Otsuka-Long-Evans-Tokushima Fatty [OLETF]) has been shown to be much higher in males than in females. To evaluate the role of sex hormones in the development of diabetes in this model, we performed biochemical and morphological studies on the effects of castration and sex hormones on the development of non-insulin-dependent diabetes mellitus in these rats. The rats were randomly assigned to six groups of 10 rats each, three groups of males and three of females. Two of the male groups and two of the female groups were castrated at 5 weeks of age, and the third male and female groups received sham operations. From 9 to 30 weeks of age, one group of castrated males received testosterone enanthate (1 mg-wk-1) and one group of castrated females received estradiol valerate (1 mg.wk-1). The other castrated groups received an equal volume of vehicle only. At 30 weeks of age, the cumulative incidences of diabetes mellitus in the sham-operated male and female rats were 100% and 0%, respectively. Orchiectomy reduced the incidence of diabetes to 20%, whereas ovariectomy increased it to 30%. Administration of sex hormones restored the incidence to 89% in males and 0% in females. In vivo insulin-stimulated glucose uptake as measured with a euglycemic clamp was reduced in sham-operated males, castrated males with hormone replacement (HR), and castrated females without HR as compared with sham-operated females and castrated females with HR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Effects of difference in amount of exercise training on prevention of diabetes mellitus in the Otsuka-Long-Evans-Tokushima fatty rats, a model of spontaneous non-insulin-dependent diabetes mellitus.

Exercise training every day has been shown to be effective in preventing the development of non-insulin-dependent diabetes mellitus (NIDDM) in a model rat (Otsuka Long Evans Tokushima Fatty (OLETF)). For determination of whether less vigorous exercise training also has a protective effect against the development of NIDDM in this model, seven male OLETF rats each were assigned to training every other day, every 3 days and every 7 days from 6 to 30 weeks of age. At 30 weeks of age, rats trained every other day, 3 days, 7 days and sedentary rats weighed averages of 547, 548, 603 and 695 g and had abdominal fat deposits of 28, 24, 32 and 72 g, respectively. The mean meterages of running of rats trained every other day, 3 days and 7 days over the whole experimental period were 9630, 5166 and 1685 m/week, respectively. At 30 weeks of age, the cumulative incidence of NIDDM in sedentary rats was 85.7% (6/7), while none of the trained rats became diabetic except for one of rats trained every 7 days. The glucose infusion rate (GIR), an index of insulin sensitivity, in the group trained every 7 days, 60.6 +/- 5.0 mumol.kg-1.min-1, was significantly greater than that in the sedentary group, 21.7 +/- 1.7 mumol.kg-1.min-1. Morphological studies on the pancreas of rats trained every other day and every 3 days showed minimal changes of islets, whereas sections of islets from rats trained every 7 days appeared enlarged and fibrotic, though significantly less so than the islets of sedentary rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Variation of the jaw-opening reflex during spontaneous mastication in rabbits.

To understand the modulation of periodontal mechanoreceptor activity on mastication, the jaw-opening reflex (JOR) evoked by electrical stimulation of the inferior alveolar nerve (IAN) was studied during chewing in freely behaving rabbits. Spontaneous chewing movements were intact from the IAN stimulation below two times the threshold (T) which was measured at rest. As the stimulus intensity was increased to more than 2.5 T, the amplitude of the masseter activity decreased or it was abolished; however, the chewing rhythm was still maintained up to 3.0 T. When the low-threshold primary afferents were tested while the rabbit chewed pellets rhythmically, the amplitude in the JOR was inhibited below the prior control level. The inhibitory effect on the JOR was larger in the opening phase than that in the closing phase. In conclusion, the JOR was tonically depressed during the masticatory cycle and the inhibition of the JOR was rhythmically modulated in a phase-linked manner that was larger in the opening phase than in the closing phase.

Animals↗
PubMed1994

Subperiosteal tissue expansion for mandibular augmentation with hydroxylapatite particles: an experimental study.

PURPOSE: The utility of subperiosteal tissue expansion (STE) for mandibular augmentation with hydroxylapatite (HA) particles was evaluated experimentally in two groups of dogs. MATERIALS AND METHODS: Eight grams of solid HA particles were implanted in previously formed bilateral subperiosteal expanded beds on the mandible. In one group, the HA particles were implanted in the intact subperiosteal expanded bed and in the other the newly formed capsule overlying the bone was removed before implantation of HA. RESULTS: Despite marked augmentation with a large number of HA particles, there was neither deformity nor infection of the implants, which maintained the original desired contour. The firm fibrous capsule formed by STE allowed consolidation of the HA particles and prevented their migration. In the first group, although histologic evidence of bony union of the implanted particles was not seen even after 2 months, clinical immobilization of the grafts was achieved in 1 to 2 months. After 1 year, substantial bone growth into the implants was observed. In the second group, clinical immobilization was observed even after 2 weeks. Histologic evidence of bony union of the particles located along the surface of the mandible was observed after 1 or 2 months. In these specimens, however, marked bone resorption of the mandibular cortex, was also noted. No evidence of bone or osteoid formation on the expanded periosteal side was noted in either group. CONCLUSION: These results provide fundamental data regarding mandibular augmentation using STE, and indicate that the subperiosteal expanded bed is an excellent recipient site for onlayed implants.

Alveolar Ridge Augmentation↗
PubMed1994

Structures of new coumarins and antitumor-promoting activity of coumarins from Angelica edulis.

From the fruits of Angelica edulis Miyabe (Umbelliferae), three new angular furanocoumarins, edulisin III (1), edulisin IV (2), and edulisin V (3), were isolated along with three known coumarins, 2'(S), 3'(R)-3'-isobutyryloxy-4'-acetoxy-2',3'-dihydrooroselol (4), edultin (5), and 2'(S),3'(R)-3'-senecioyloxy-4'-acetoxy-2',3'-dihydrooroselol (6), respectively. The structures of 1 and 2 were established to be 2'(S),3'(R)-3'-(2-methylbutyryloxy)-4'-acetoxy-2',3'-dihydrooro selol and 2'-(S),3'(R)-3'-propyryloxy-4'-acetoxy-2',3'-dihydrooroselol by chemical studies and spectral analyses. Coumarin 3 was proved to be 3'-(2-methylbutyryl-oxy)-4'-angeloyloxy-2',3'-dihydrooroselol++ + by chemical and spectral analyses and H-C COLOC. Coumarins 1-6 were examined for the effects on tumor-promotor induced phenomena in vitro. Among these coumarins, 3 showed the most potent inhibitory activity on 12-O-tetradecanoylphorbol 13-acetate (TPA)-stimulated 32Pi incorporation into phospholipids of cultured cells.

Antineoplastic Agents, Phytogenic↗
PubMed1994

Cloning, sequencing and expression in Escherichia coli of the gene for alpha antigen from Mycobacterium scrofulaceum.

The gene for the extracellular alpha antigen of Mycobacterium scrofulaceum (S-alpha) was cloned by using the alpha antigen gene fragments of Mycobacterium bovis BCG as probes. The complete nucleotide sequence was determined. The gene was expressed in Escherichia coli. The gene encodes 330 amino acids, including 40 amino acids for the signal peptide, followed by 290 amino acids for the mature protein. The deduced amino acid sequences were highly homologous to the alpha antigen of the species of other mycobacteria. Interestingly, the alpha antigens of MAIS complex (Mycobacterium avium-Mycobacterium intracellulare-M. scrofulaceum) were closely homologous even at the C-terminal regions which were variable among those of M. bovis BCG, Mycobacterium leprae and Mycobacterium kansasii.

Amino Acid Sequence↗
PubMed1994

ATBF1, a multiple-homeodomain zinc finger protein, selectively down-regulates AT-rich elements of the human alpha-fetoprotein gene.

ATBF1 is a 306-kDa protein containing four homeodomains, 17 zinc finger motifs, and several segments potentially involved in transcriptional regulation (T. Morinaga, H. Yasuda, T. Hashimoto, K. Higashio, and T. Tamaoki, Mol. Cell. Biol. 11:6041-6049, 1991). At least one of the homeodomains of ATBF1 binds to an AT-rich element in the human alpha-fetoprotein (AFP) enhancer (enhancer AT motif). In the present work, we analyzed the transcriptional regulatory activity of ATBF1 with respect to the enhancer AT motif and similar AT-rich elements in the human AFP promoter and the human albumin promoter and enhancer. Gel retardation assays showed that ATBF1 binds to the AFP enhancer AT motif efficiently; however, it binds weakly or not at all to other AT-rich elements in the AFP and albumin regulatory regions studied. Alterations of the enhancer AT motif by site-specific mutagenesis resulted in the loss of binding of ATBF1. Cotransfection experiments with an ATBF1 expression plasmid and the chloramphenicol acetyltransferase (CAT) gene fused to AFP promoter or enhancer fragments showed that ATBF1 suppressed the activity of AFP enhancer and promoter regions containing AT-rich elements. This suppression was reduced when the mutated AT motifs with low affinity to ATBF1 were linked to the CAT gene. The ATBF1 suppression of AFP promoter and enhancer activities appeared to be due, at least in part, to competition between ATBF1 and HNF1 for the same binding site. In contrast to the AFP promoter and enhancer, the albumin promoter and enhancer were not affected by ATBF1, although they contain homologous AT-rich elements. These results show that ATBF1 is able to distinguish AFP and albumin AT-rich elements, leading to selective suppression of the AFP promoter and enhancer activities.

Animals↗
PubMed1994

Analysis of the transport of valproic acid into saliva from serum.

A study was conducted to explore whether a positive correlation between serum and salivary concentrations of the well-known antiepileptic drug, valproic acid (VPA), in epileptic patients could be explained by facilitated diffusion. The total concentration in saliva (Cs) would be related to the apparent ratio (R(app)++ = 100.Cs/Ct) of Cs to the total concentration in serum (Ct) as follows: Cs = A.R(app)B. This equation can be illustrated with microcomputer-simulated figures by assuming a process of facilitated diffusion for the transport of VPA into saliva from blood by the mechanism of monocarboxylic acid absorption through the intestinal brush-border membrane vesicles. The above equation has been proved to be valid when applied to the data reported separately by Gugler and coworkers and by Nitsche and Mascher, who evaluated the pharmacokinetics of VPA. Moreover, we can estimate the serum concentration with the salivary concentration using the above equation.

Adolescent↗
PubMed1994

Right atrial myxoma with right to left shunt and coronary artery disease.

Surgical treatment of a right atrial myxoma with a right-to-left shunt and coronary artery disease was successfully performed in a 61-year-old man. The interatrial shunt occurred through a patent foramen ovale and was the result of a high central venous pressure due to tricuspid stenosis and regurgitation. Instead of right heart catheterization and cardioangiography, we chose an intraoperative blood-gas study to diagnose the intracardiac shunt. Preoperative polycythemia and hypoxemia were improved after removal of the tumor and closure of the patent foramen ovale.

Central Venous Pressure↗
PubMed1994

[Bacteria isolated from intraabdominal infection and their susceptibilities to antimicrobial agents].

Bacteria isolated from intraabdominal infections during the period from July 1982 to June 1993 were investigated with regard to their classifications according to a joint research by 9 university hospitals in Japan. The following results were obtained. 1. A total of 971 strains were isolated from 684 out of 597 patients with peritonitis, and 287 strains out of 971 were isolated from postoperative peritonitis. 2. The most predominant organism isolated from patients with acute peritonitis was Escherichia coli (28%), followed by Bacteroides fragilis group (17%), Gram-positive anaerobic cocci (16%), Enterococcus spp. (9%) and Klebsiella spp. (8%). 3. Against E. coli, cefmenoxime, cefuzonam, cefozopran, aztreonam and carumonam showed MIC50 less than 0.05 micrograms/ml. Against B. fragilis group, erthromycin, clindamycin, imipenem, lincomycin and latamoxef showed MIC50 less than 0.78 micrograms/ml. 4. The most predominant organism isolated from patients with postoperative peritonitis was Enterococcus spp. (20%) and followed by Pseudomonas spp. (14%), and Staphylococcus spp. (13%), E. coli (9%), Enterobacter spp. (8%) and Klebsiella spp. (8%). We suggest that cefazolin, cefmetazole, flomoxef, cefmenoxime, cefuzonam, and latamoxef are the first choice agents in empiric therapy for the treatment of acute peritonitis.

Aged↗
PubMed1994

Near-infrared Fourier transform Raman spectroscopic study of cornea and sclera.

Near-infrared excited Fourier transform Raman spectroscopy was applied in situ on intact rabbit cornea and sclera. High quality Raman spectra were obtained noninvasively from these tissues. The characteristic bands assigned to proline and hydroxyproline appeared in the region of 800-1000 cm-1. Raman spectra of purified type I collagen and other components of the cornea and sclera were also determined. The main elements of the spectra of the cornea and sclera originated from the collagen proteins, and other components such as proteoglycan contributed little. Near-infrared excited Fourier transform Raman spectroscopy can be used for biophysical study of the cornea and sclera in situ or in vivo.

Animals↗
PubMed1994

[Correlation between reperfusion ventricular fibrillation and postoperative enzyme release in coronary artery bypass grafting].

Twenty patients who had undergone elective coronary artery bypass grafting were divided into two groups according to the cardiac rhythms after aortic declamping. Eight patients had ventricular fibrillation (Vf group) and 12 patients had spontaneous resumption of heart beating in regular sinus rhythm (SPB group). In Vf group, percent CK-MB and absolute value of CK-MB on the first postoperative day showed significant increase compared with those of the SPB group (p < 0.01). Furthermore, duration of ventricular fibrillation after aortic declamping tended to be positively correlated (r = 0.7018) with absolute value of CK-MB on the first postoperative day, although this did not reach statistic significance (p = 0.0523). To the contrary, between the two groups no significant difference was found in percent LDH1, absolute value of LDH1, and ratio of LDH1 to LDH2 on the first and third postoperative day. It is suggested that ventricular fibrillation after aortic declamping plays a crucial role in increasing postoperative CK-MB level, and its duration is presumably correlated with the absolute value of CK-MB on the first postoperative day.

Adult↗
PubMed1994

[A case of left main coronary artery stenosis: additional insertion of saphenous vein graft to discontinue cardiopulmonary bypass].

A 62-year-old man with the lesions of the left main coronary artery and all the three vessels underwent a complete revascularization, in which the left internal mammary artery (IMA) was anastomosed to the large LAD. Although the operation proceeded uneventfully, the patient could not be weaned from the cardiopulmonary bypass (CPB). Another saphenous vein graft insertion into the LAD just distal to the IMA made it possible to discontinue the CPB. Postoperative angiogram revealed the patency of all grafts. But the IMA graft showed flow competition and string sign. We assume that failure to wean the patient from the CPB might be caused by hypoperfusion of the IMA graft, and in such a case, insertion of a saphenous vein graft is effective.

Anastomosis, Surgical↗
PubMed1994

The effect of probucol on the development of non-insulin dependent diabetes mellitus in Otsuka Long Evans Tokushima Fatty (OLETF) rats.

The effect of probucol which acts as a scavenger of free radicals, on preventing the development of non-insulin dependent diabetes mellitus (NIDDM) in a model rat (Otsuka Long Evans Tokushima Fatty [OLETF]) was examined. Sixteen male OLETF rats aged 5 weeks were divided into two groups. One group were fed standard laboratory chow and the other group were fed the chow containing 1% probucol. At 12, 16, 24 weeks of age, an oral glucose tolerance test (OGTT) was performed. At 24 weeks of age, the cumulative incidences of diabetes mellitus in both groups were 100%. After two weeks, insulin-mediated glucose uptake was measured using a euglycemic clamp technique. There was no significant difference in glucose infusion rates between both groups. At the end of the experiment, plasma lipid concentrations were measured. The serum total cholesterol levels were significantly lower in rats fed probucol containing chow (66.3 +/- 3.7 mg/dl) than those of rats fed standard laboratory chow (78 +/- 6.4 mg/dl). On the other hand, the serum triglyceride level were not significantly different between them. Histological studies on the pancreas of both groups showed enlarged fibrotic islets and mononuclear cell infiltration in the periinsular area, though to a modest extent. These results demonstrated that probucol was not effective in preventing the development of NIDDM in this model animal. Considering these data, inflammatory destruction of pancreatic beta cells by free radical may not be involved in the development of NIDDM.

Animals↗
PubMed1994

[Surgical intervention to tuberculous pericarditis: a case report].

A 32-year-old man was hospitalized because of cardiac tamponade with the thickened visceral and parietal pericardial layers. Marked high level of adenosine deaminase activity (ADA) in pericardial fluid strongly suggested the diagnosis of tuberculous pericarditis, which was later assured by positive smear and culture of the pericardial fluid for Mycobacterium tuberculosis. Before rigid adhesion of the pericardial space was established, pericardiectomy was easily performed with satisfactory improvement of the hemodynamic status and physical symptoms of the patient. The present case suggests the efficacy of early surgical intervention to tuberculous pericarditis when it shows a sign of rapid progression to constrictive pericarditis. Furthermore, high ADA in pericardial fluid might be an useful diagnostic modality for tuberculous pericarditis.

Adenosine Deaminase↗
PubMed1994

[A technique of successfully performing an annuloplasty for narrowed aortic valvular annulus in aortic valve replacement].

We previously reported that a significant reduction in both myocardial weight and left ventricular end-diastolic volume weight and left ventricular end-diastolic volume was achieved with the use of an artificial valve of 21 mm size in aortic valve replacement (AVR) performed on aortic stenosis patients with a body surface area of less than 1.4 m2. In those patients with a narrower valvular annulus on a unit body surface area basis, however, we have aggressively performed an operation of enlarging the valvular annulus in conjunction with AVR with a similar satisfactory hemodynamic improvement invariably in all cases, including 3 without autologous blood transfusion. In this paper mention is made, based on our experiences gained so far, of some points of critical technical importance for the successful performance of AVR involving annuloplasty, specification by the Manouguian's and Konno's procedure.

Adolescent↗