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T Mizoguchi

Publications and source records attributed to T Mizoguchi.

At least 55 records · Page 3Linked to original sources
PubMed1998

A null lesion in the rhodopin 3,4-desaturase of Rhodospirillum rubrum unmasks a cryptic branch of the carotenoid biosynthetic pathway.

The carotenoids accumulated by a mutant Rhodospirillum rubrum ST4, containing a single Tn5 lesion in the pathway for carotenoid biosynthesis, were analyzed by HPLC, 1H NMR spectroscopy, and field desorption mass spectrometry. The main carotenoid was identified as 3,4,3',4'-tetrahydrospirilloxanthin, and the four minor carotenoids were identified as rhodopin, 3,4-dihydroanhydrorhodovibrin, 3', 4'-dihydrorhodovibrin, and 1,1'-dihydroxylycopene. The C-3,4 and C-3',4' bonds of all 5 carotenoids are saturated, and they have 11 conjugated double bonds. With the exception of rhodopin, which is a normal intermediate of the wild-type pathway, all of the carotenoids are not naturally occurring. The Tn5 lesion was assigned to rhodopin 3,4-desaturase which is proposed to catalyze dehydrogenation at both ends of the symmetrical spirilloxanthin derivative. An unexpected finding was that the enzymes following rhodopin 3,4-desaturase are still able to end-modify the 3,4-, and 3',4'-saturated precursors and that the order of methylation and hydroxylation is not obligatory. It is proposed that the observed nonnatural carotenoids can be explained by the inclusion of a cryptic branch, unmasked by the absence of rhodopin 3,4-desaturase, in the established linear pathway for spirilloxanthin biosynthesis. This is the first example of latent branching of the carotenoid biosynthesis pathway exhibited by a carotenoid mutant of a phototrophic bacterium.

Carotenoids↗
PubMed1998

Broad spectrum and mode of action of an antibiotic produced by Scytonema sp. TISTR 8208 in a seaweed-type bioreactor.

A photobioreactor was constructed using anchored polyurethane foam strips (1 x 1 x 40 cm) fixed onto a stainless-steel ring to prevent flotation, as a biomass support material (BSM). This type of reactor was named a seaweed-type bioreactor. A filamentous cyanobacterium, Scytonema sp. TISTR 8208, which produces a novel cyclic dodecapeptide antibiotic, was immobilized in seaweed-type photobioreactor and cultivated with air containing 5% CO2 sparged at a gas flow rate of 250 mL/min under illumination at a light intensity of 200 mmol photon m-2 s-1. The antibiotic produced in the seaweed-type photobioreactor was purified by HPLC and examined regarding its spectrum and mode of action. The antibiotic effectively inhibited the growth of Gram-positive bacteria, pathogenic yeasts, and filamentous fungi, but it had only a weak effect on Gram-negative bacteria. Scanning electron micrograph analysis showed that the most characteristic change was swelling of the cells after exposure to the antibiotic. The antibiotic seems to alter the conformation of the microbial cell membrane, thereby changing its permeability, leading to osmotic shock.

Anti-Bacterial Agents↗
PubMed1998

Cloning and sequence analysis of the poly (3-hydroxyalkanoic acid)-synthesis genes of Pseudomonas acidophila.

Pseudomonas acidophila can grow with CO2 as a sole carbon source by the possession of a recombinant plasmid that clones genes that confer chemolithoautotrophic growth ability derived from the H2-oxidizing bacterium Alcaligenes hydrogenophilus. H2-oxidizing bacteria produce poly(3-hydroxybutyric acid) (PHB) from CO2, but recombinant P. acidophila can produce the more useful biopolymer poly(3-hydroxyalkanoic acid) (PHA). In this study, the pha genes of P. acidophila were cloned and a sequence analysis was carried out. A gene library was constructed using the cosmid vector pVK102. A recombinant cosmid carrying the pha genes was selected by the complementation of a PHB-negative mutant of Alcaligenes eutrophus H16. The resulting recombinant cosmid pIK7 contained a 14.8-kb DNA insert. Subcloning was done. and the recombinant plasmid pEH74 was selected by hybridization with the A. eutrophus H16 pha genes. Escherichia coli possessing pEH74 produced PHB, indicating that pEH74 contained the pha genes of P. acidophila. The nucleotide sequences of the PHA-synthesis genes phaA (beta-ketothiolase), phaB (acetoacetyl-CoA reductase), and phaC (PHA synthase) in pEH74 were determined. The homologies of phaA, phaB, and phaC between P. acidophila and A. eutrophus H16 were 64.7, 76.1 and 56.6%, respectively.

Acetyl-CoA C-Acyltransferase↗
PubMed1998

Quantitative electroencephalographic correlates of cerebral blood flow in patients with chronic subdural hematomas.

BACKGROUND: We have observed that the reduction in cerebral blood flow (CBF) of patients with chronic subdural hematomas is always most pronounced in the thalamus and has a linear correlation with the degree of brain deformity caused by the compression from the hematoma. When the brain is markedly displaced by a hematoma, electroencephalography (EEG) shows delta waves in the frontal region. We theorized that the flow reduction begins in the thalamus, spreading throughout the hemisphere as displacement progresses. METHODS: We measured CBF using the xenon/computed tomography (CT) method in 10 patients with chronic subdural hematomas who had hemiparesis and/or a mental disturbance and radiographic evidence of a midline shift or herniation. We correlated their flow reductions with topographic encephalograms. RESULTS: Flow reductions were more pronounced in the thalamus than in the hemisphere and cortex. Slow waves dominated over fast waves, especially in the frontopolar and frontal regions bilaterally. Flow values correlated negatively with the presence of delta and theta waves and positively with that of alpha and beta waves. On the side of the hematoma, the brain wave activity correlated significantly with thalamic flow, and the correlation was greater than with the hemispheric or cortical flow. Thalamic flow correlated more consistently with delta and alpha waves in the central, temporal, and occipital regions, and with beta waves in the frontopolar, frontal, and central regions. On the nonhematoma side, the correlation between brain wave activity and hemispheric flow was significant and greater than with cortical or thalamic flow. CONCLUSIONS: The correlation of EEGs with thalamic flow, which was maximally reduced, seems to substantiate the concept that the thalamus is primarily injured by brain distortion due to the compression from hematoma and that the remote areas are secondarily deactivated by a transneural depression ("diaschisis") originating from the dysfunctioning thalamus. Thalamic involvement seems to be the cause of the neurologic dysfunction and the abnormal EEG activity in chronic subdural hematomas.

Aged↗
PubMed1998

Phacoemulsification, intraocular lens implantation, and trabeculotomy to treat pseudoexfoliation syndrome.

PURPOSES: To determine the long-term risk/benefit ratio of phacoemulsification and intraocular lens (IOL) implantation combined with trabeculotomy to manage eyes with pseudoexfoliation syndrome and co-existing cataract. SETTING: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine; Kurihara Eye Clinic; Departments of Ophthalmology, Tenri Hospital, Kumamoto University, and Matsue Red Hospital; Nagata Eye Clinic, Japan. METHODS: This multicenter retrospective study comprised 49 eyes of 36 patients with pseudoexfoliation syndrome and co-existing cataract who had the combined procedure for uncontrolled intraocular pressure (IOP) (> 21 mm Hg) even on antiglaucoma medication. RESULTS: After a mean follow-up of 20.0 months +/- 13.2 (SD), IOP in all 49 eyes was well controlled (< or = 21 mm Hg). Mean IOP at the final examination was 14.6 +/- 2.6 mm Hg on a mean of 0.9 +/- 0.8 glaucoma medications. Complications included an IOP spike in 11 eyes and fibrin exudation in 1 eye. CONCLUSION: Phacoemulsification and IOL implantation combined with trabeculotomy was an effective treatment for patients with pseudoexfoliation syndrome and cataract.

Aged↗
PubMed1998

The glycosylation sites and structural characteristics of oligosaccharides on recombinant human thrombomodulin.

Thrombomodulin (TM) is an anticoagulant glycoprotein on the surface of endothelial cell that directly inhibits the procoagulant activities of thrombin, and the TM-thrombin complex accelerates thrombin-catalyzed activation of protein C. Soluble TM in urine has no glycosaminoglycan (GAG) chain which accelerates the anticoagulant activities. Therefore, we expressed recombinant GAG-modified urinary thrombomodulin (GAG-UTM) in C127 cells. The glycosylation sites were determined by amino acid sequence analysis of peptides digested with trypsin after S-carboxymethylation. The structures of N-linked oligosaccharides were estimated by two-dimensional sugar mapping of pyridylaminated oligosaccharides that were treated with exoglycosidase. The disaccharide composition analysis of the GAG chain was performed by HPLC using digestion with chondroitinase ABC, ACII and B. Consequently, it was revealed that the N-linked oligosaccharides were assigned to Asn29, Asn98, Asn364, Asn391; those structures were estimated biantennary, 2-6 branched triantennary and 2-4 branched triantennary complex type oligosaccharides that were linked by fucose at the ratio of 1.0:0.5:0.1, respectively. Moreover, the attachment site of the GAG chain was assigned to Ser472. It was then estimated that the GAG chain contained chondroitin-4-sulfate and dermatan sulfate, which were repeated approximately 30 times. In this paper, the GAG attachment site and structural characteristics of GAG-UTM, were confirmed. Moreover, structures of the N-linked oligosaccharides of GAG-UTM are described for the first time.

Amino Acid Sequence↗
PubMed1998

D-erythrulose reductase can also reduce diacetyl: further purification and characterization of D-erythrulose reductase from chicken liver.

We have discovered new characteristics of D-erythrulose reductase, namely, that it can catalyze reduction of not only D-erythrulose but also such diketones as diacetyl. These substrates have a common structure with two neighboring carbonyls possibly in s-cis plane structure, showing that the enzyme may rigorously distinguish between substrates and other compounds. D-Erythrulose reductase was predominantly located in the kidney and the liver of the chicken. The obtained results suggest that D-erythrulose reductase plays an important role in metabolizing alpha-dicarbonyls in animal organs, because these diketones widely occur in natural foods.

Animals↗
PubMed1998

Importance of sialic acid in recombinant thrombomodulin in terms of pharmacokinetics and separation of desialyzed glycoprotein.

Recombinant glycosaminoglycan-modified urinary thrombomodulin (GAG-UTM) expressed in mouse C-127 cells has potent antithrombotic activity available as an anticoagulant. GAG-UTM, a glycoprotein with sialic acid, was investigated regarding the influence of the terminal sialic acid on its pharmacokinetics upon rapid intravenous injection in rat. Asialo GAG-UTM desialated by neuraminidase was cleared rapidly from plasma. Sialyzed GAG-UTM, a sialyzed asialo GAG-UTM with alpha-2, 6-sialyltransferase, containing sialic acid similarly to native sialo GAG-UTM, had only a short half-life in plasma, suggesting that the binding site of sialic acid on galactose was not only sialyzed with alpha-2, 6-sialyltransferase but also with 2, 3-sialyltransferase. Asialo GAG-UTM with oxidized terminal galactose, however, had a long half-life. These results suggest that terminal sialic acid may be important to the pharmacokinetics of GAG-UTM; therefore, an analysis of asialo GAG-UTM became significant for quality control. In order to analyze sialo- and asialo-types in the early stage of purification, we investigated separation and analysis methods for both types and found a suitable sample of each: RCA-120-Agarose column for separation and ELISA using anti-thrombomodulin antibody and RCA lectin for analysis.

Animals↗
PubMed1998

Intraoperative management for removal of tumor thrombus in the inferior vena cava or the right atrium with multiplane transesophageal echocardiography.

BACKGROUND: To investigate the role and impact of multiplane transesophageal echocardiography during thrombectomy in the inferior vena cava or the right atrium. EXPERIMENTAL DESIGN: Retrospective. SETTING: A university hospital. PARTICIPANTS: Four patients who underwent removal of tumor thrombus in the inferior vena cava (IVC) or the right atrium. INTERVENTIONS: The medical records of 4 patients and videotapes of these intraoperative transesophageal echocardiography examinations were reviewed. RESULTS: Before thrombectomy, multiplane transesophageal echocardiography (MTEE) provided excellent IVC long axis view, which offered precise recognition of the cephalic extent of tumor, extent of caval occlusion, characterization of the tumor head. During surgery, MTEE could provide continuous monitoring of cardiac function, cardiac volume, and pulmonary embolism. Moreover, MTEE could provide the useful images of a cannula or the caval occlusion balloon catheter, which facilitated removal of neoplasm extending into the IVC. CONCLUSIONS: We presented four surgical cases, in which the removal of the tumor extended into the inferior vena cava or the right atrium using MTEE. MTEE could provide valuable information such as excellent images of the tumor, cardiac function, the position of a cannula or the caval occlusion balloon catheter. These findings could improve the anesthetic management of the patients, as well as the surgical approach and technical maneuvers, and facilitate removal of neoplasm into the IVC.

Adult↗
PubMed1997

Environmental stress response in plants: the role of mitogen-activated protein kinases.

Mitogen-activated protein kinase (MAPK) cascades have essential roles in diverse intracellular signaling processes in plants, animals and yeasts. In plants, transcription of genes encoding protein kinases involved in MAPK cascades is upregulated by environmental stresses and plant hormones; in addition, MAPK-like kinase activities are transiently activated in response to environmental stresses. Consequently, MAPK cascades are now thought to have important roles in stress signal transduction pathways in higher plants.

Phosphorylation↗
PubMed1997

Effectiveness of fructose-modified chitosan as a scaffold for hepatocyte attachment.

Free amino groups of chitosan, a substance which has previously been shown to be a good scaffold for hepatocyte attachment, were covalently modified with fructose. The modification significantly increased the number of cells that could be attached on the surface of chitosan gel. Rat hepatocytes cultivated on fructose-chitosan behaved similarly to those on unmodified chitosan, i.e., they retained the spherical shape they have in vivo, and released much less lactate dehydrogenase than cells attached on a collagen-coated surface. The modification with fructose did not alter the important characteristics of chitosan for hepatocyte culture: liver-specific functions such as urea synthesis and drug metabolism were stably maintained for 5 d in the hepatocytes cultured on fructose-chitosan. In sharp contrast, hepatocytes attached on a collagen-coated surface underwent a severe morphological change, from spherical to flat, and lost almost all their lidocaine-removal activity within 5d. A very thin fructose-chitosan layer was also applied onto the collagen-coated surfaces of polystyrene plates and a dextran microcarrier by crosslinking free amino groups in the chitosan and collagen with glutaraldehyde to fix the thin layer. Hepatocytes on the fructose-chitosan-coated surface retained their spherical shape, masking the cell-flattening effect of the collagen layer. Perfusion culture was then carried out using a hollow-fiber cartridge in which hepatocytes attached on fructose-chitosan-coated microcarriers were suspended in the extracapillary space: the liver-specific functions were stably maintained during 4d of the culture. A fructose-chitosan-coated surface thus appears to be a very promising scaffold for hepatocyte attachment which can be used in cellular biological studies of liver functions, especially in relation to cytochrome P450, as well as in bioartificial liver support systems.

Animals↗
PubMed1997

Application of glutaraldehyde-crosslinked chitosan as a scaffold for hepatocyte attachment.

The effectiveness of chitosan, a biocompatible polymer derived by the deacetylation of chitin, as a scaffold of hepatocyte attachment, was examined. Since chitosan gel was too fragile to use for cell culture, its free amino groups were crosslinked by glutaraldehyde to increase its strength. Rat hepatocytes seeded onto glutaraldehyde-crosslinked chitosan (GA-chitosan) gel could stably attach to the surface, retaining its spherical form, the same as in vivo, and then release a very small amount of lactate dehydrogenase during the 5 d culture period. By contrast, hepatocytes on a collagen-coated surface spread flat, and they released much more lactate dehydrogenase than those on the GA-chitosan gel. Hepatocytes on GA-chitosan also retained higher urea synthesis activity, a liver-specific function, than those on the collagen-coated surface. These results indicate that chitosan is a promising biopolymer as a scaffold of hepatocyte attachment, which can be applied to an effective bioartificial liver support system.

Animals↗
PubMed1997

[Geriatrics in the new program for initial postgraduate medical training in Japan].

Until 1993, initial postgraduate medical training in Japan was conducted only at university hospitals or other teaching hospitals. In 1994, the number of types of training sites was expanded to include health centers, nursing homes, and extended care facilities, which gave trainees chances to understand primary medical care in various settings, providing in-home as well as other non-hospital medical services. Since the new program seemed to increase training opportunities in geriatric medicine, questionnaires regarding the new program were sent by mail to all teaching hospitals in Japan (261); 213 responded. The results showed that 29 hospitals already had a program of care for the aged. The teaching sections were mainly internal medicine, psychiatry and rehabilitation medicine. Fifty hospital had plans to include care for the aged in their program in the near future. The number of programs that includes training in care for the aged is gradually increasing. It is hoped that during their initial postgraduate training many young doctors will come to recognize the importance of geriatric medicine.

Education, Medical, Graduate↗
PubMed1997

Cineradiographic evaluation of ATS open pivot bileaflet valves.

BACKGROUND AND AIMS OF THE STUDY: Echocardiography and cineradiography are both valuable for the evaluation of prosthetic valve function, especially of mechanical valves. Although Doppler echocardiography data are available for the recently developed ATS valve, cineradiographic evaluation of leaflet movement of the valve has not been performed. MATERIALS AND METHODS: Five patients received aortic and another five mitral valve replacement with the open pivot ATS bileaflet prosthetic valve. There were three men and seven women; mean patient age was 58.8 years. Cineradiographic and Doppler echocardiographic evaluations of the ATS valve were performed early after surgery in all 10 patients. RESULTS: There were no early deaths after surgery or after discharge from the hospital. No valve-related complications were seen, and no clinical symptoms or signs of prosthetic malfunction were observed during the follow up period. Doppler-derived values of the ATS valve were comparable with those previously reported; however, cineradiography of the valve demonstrated that the mean angle enclosed by the two open leaflets was 37.6 degrees (range: 34 degrees to 44 degrees) in the aortic position and 29.7 degrees (range: 20 degrees to 35 degrees) in the mitral position. Mean leaflet mobility was 93.0 degrees (range: 86 degrees to 96 degrees) in the aortic position and 100.0 degrees (range: 92 degrees to 110 degrees) in the mitral position. Thus, the opening of the normally functioning ATS valves in vivo was less than that observed in vitro and reported by the manufacturer. CONCLUSIONS: These results suggest that unevenly distributed blood flows with different velocities through the two side orifices and the central orifice may result in incomplete opening of the ATS leaflets, which respond with great sensitivity to localized blood flow. Our findings appear to be important to avoid the removal of a normally functioning ATS valve only because the leaflet opening appears to be 'restricted'.

Adult↗
PubMed1997

Trabeculotomy combined with phacoemulsification and implantation of an intraocular lens for the treatment of primary open-angle glaucoma and coexisting cataract.

BACKGROUND AND OBJECTIVE: The authors previously reported the usefulness of trabeculotomy ab externo for the treatment of primary open-angle glaucoma in adult patients. In an attempt to elucidate the long-term risk-to-benefit ratio of this surgical modality in combination with cataract surgery, the authors conducted a retrospective study of the surgical effects and complications of a triple procedure: phacoemulsification, implantation (of an intraocular lens), and trabeculotomy (PIT). PATIENTS AND METHODS: The authors conducted a retrospective study of patients treated with PIT at multiple hospitals. Intraocular pressure (IOP) and visual function data were obtained from patients after PIT as an initial surgical treatment in cases where antiglaucoma medications failed to resolve uncontrolled IOP (higher than 21 mm Hg). Included in this study were 96 eyes of 64 patients with primary open-angle glaucoma and coexisting cataract. The mean follow-up period was 22.6 +/- 14.7 months (range 3-56 months). RESULTS: In 94 (98%) of the 96 eyes, the IOP was well controlled, having achieved a level of 21 mm Hg or lower at the final examinations. The mean preoperative IOP of the 33 eyes that underwent the triple procedure using a single flap method (PIT-I) was 24.3 +/- 3.9 mm Hg, with an average of 2.1 +/- 1.1 medications. At the final examinations, the mean IOP had dropped to 16.0 +/- 1.2 mm Hg, with an average of 1.2 +/- 1.2 medications. The mean preoperative IOP of the 63 eyes that underwent the triple procedure using a double flap method (PIT-II) was 26.2 +/- 6.2 mm Hg, with an average of 1.9 +/- 1.2 medications. At the final examination, the mean IOP for this group was 15.6 +/- 2.9 mm Hg, with an average of 1.0 +/- 0.9 medications. CONCLUSION: The long-term results from this multicenter study showed that the triple procedure, PIT, can be useful and effective as an initial surgical treatment for open-angle glaucoma in glaucoma patients with coexisting cataract.

Adult↗
PubMed1997

[The long-term cystic bleb appearance and safety after trabeculectomy with mitomycin C].

The clinical appearance of cystic blebs and the incidence of bleb infection were retrospectively evaluated in 215 trabeculectomies with mitomycin C. The incidence of cystic bleb formation in trabeculectomy was 79% (169/215). The cumulative incidence of the cystic bleb survival when using the Kaplan-Meier method was 73% in the 50th month after surgery. The incidence of large cystic bleb survival was better than that of small and localized cystic blebs. There was statistically significant difference. The incidence of cystic bleb survival without Seidel phenomenon and bleb infection was 96% in the first year after surgery and 91% in the third year. Bleb infections occurred in two of 169 eyes (1.2%). Bleb infection was successfully treated and there were no cases of endophthalmitis. The large cystic blebs had a higher incidence of bleb infection than the small ones. In one of 25 eyes treated with antibiotic eye drops after surgery, the Seidel test was positive and bleb infection occurred. The Seidel test was positive in 5 of 96 eyes in which antibiotic eye drops were not used and bleb infection occurred in one of these 5 eyes.

Female↗