Construction and characterization of pyocin-colicin chimeric proteins

Chimeric proteins were constructed from pyocin S1 or S2 and colicin E3 or E2, and their characteristics were investigated with special reference to the domain structure. The nuclease domains were interchangeable between two bacteriocins so that a new kind of pyocin, with RNase activity, was created. A bacteriocin which can kill both Pseudomonas aeruginosa and Escherichia coli was also constructed. Investigations with various chimeric proteins indicate that the translocation domain as well as the receptor-binding domain is species specific. Inhibition of lipid synthesis, which is characteristic of pyocins, was also observed with chimeric pyocins carrying the DNase domain of colicin E2 but not with those carrying the RNase domain of E3. Thus, the DNase domain is responsible for the inhibition of lipid synthesis.

Cloning of a gene encoding a putative carbon catabolite repressor from Trichoderma reesei

We report the cloning and sequencing of a Trichoderma reesei genomic DNA clone that encodes a protein similar to the Aspergillus CREA, a carbon catabolite repressor. The deduced amino acid sequence predicts a zinc finger protein of 402 amino acids in length. The overall amino acid sequence of the T. reesei CREA shows about 52% similarity with Aspergillus CREAs.

Iodine-123 metaiodobenzylguanidine images reflect intense myocardial adrenergic nervous activity in congestive heart failure independent of underlying cause

OBJECTIVES

This study was undertaken to assess myocardial adrenergic activity using iodine-123 metaiodobenzylguanidine (MIBG) imaging in patients with heart failure.

BACKGROUND

In patients with congestive heart failure, adrenergic nerve activity is accelerated. However, whether myocardial adrenergic nerve activity reflects the severity of heart failure and its relation to the underlying cause have not yet been elucidated.

METHODS

Planar MIBG images were obtained from 96 patients with heart failure and compared with images from 9 age-matched healthy subjects. Groups 1 and 2 included 65 patients with heart failure related to impaired myocardial function and whose left ventricular ejection fraction was < 40% (group 1 = 40 patients with dilated cardiomyopathy; group 2 = 25 patients with ischemic cardiomyopathy). Group 3 included 31 patients with heart failure related to a mechanical abnormality and whose left ventricular ejection fraction was > 40% (mitral regurgitation in 16, aortic regurgitation in 9, aortic and mitral regurgitation in 4, ruptured aneurysm of Valsalva in 2). Myocardial uptake of MIBG was calculated as the heart/mediastinal activity ratio. Storage and release of MIBG were calculated as percent myocardial MIBG washout from 15 min to 4 h after isotope injection.

RESULTS

The heart/mediastinal activity ratio in the immediate images (15 min) showed a significant decrease only in patients with severe heart failure (groups 1 and 2). The myocardial washout was accelerated in all three heart failure groups. The level of myocardial washout was related to severity of heart failure and correlated well with New York Heart Association functional classification.

CONCLUSIONS

In severe heart failure associated with cardiomyopathy, norepinephrine uptake is reduced. In addition, myocardial adrenergic nerve activity is accelerated in proportion to severity of heart failure, independent of the underlying cause.

Central GABAergic mechanisms are defective in salt-induced hypertension in borderline hypertensive rats

We examined the role of central GABAergic mechanisms in salt-induced hypertension and exaggerated responses to stress in borderline hypertensive rats (BHR), the first offspring of spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The studies were done in conscious BHR and WKY on high (H) (8% NaCl) or normal (N) (0.3% NaCl) salt diets for 5 weeks. A high-salt diet elevated arterial pressure (AP) (p < 0.01) and augmented pressor responses to shaker stress (p < 0.05) in BHR but not in WKY. Intravenous hexamethonium caused a greater decrease in AP in BHR-H than in BHR-N at rest. Muscimol (a GABA agonist) injected into the central ventricle (i.c.v.) caused a greater decrease in resting AP (p < 0.01) and heart rate (HR) (p < 0.05) and BHR-H than in BHR-N. Renal sympathetic nerve activity (RSNA) did not change in BHR-H, but increased (p < 0.05) in BHR-N during muscimol-induced hypotension, although the magnitudes of muscimol-induced hypotension were greater in BHR-N than in BHR-N. The increases in RSNA in response to intravenous nitroglycerin were similar in BHR-N and BHR-N. Muscimol attenuated pressor and tachycardic responses to stress more in BHR-N than in BHR-N (p < 0.01). Muscimol did not alter AP and HR at rest or their responses to stress in the two groups of WKY. The magnitudes of pressor response to bicuculline (a GABA antagonist) did not differ between the two groups of BHR. These results suggest that a high salt diet may alter the central GABAergic system in BHR, which contributes to salt-induced hypertension and augmented pressor and tachycardic responses to stress.

Isolation of Campylobacter spp. from slaughtered cattle and swine on blood-free selective medium

The charcoal-cefazolin-sodium deoxycholate agar (CCDA) was compared with Butzler agar for selectivity of campylobacters from fecal samples. A total of 279 samples of cecal contents from 176 cattle and 103 pigs slaughtered in Saitama were examined. Fifty-five (31.3%) cattle were found to contain campylobacters by the direct plating culture on CCDA plates, compared with 29 (16.5%) on Butzler agar plates. The positive rates of pig samples on CCDA and Butzler agar were very high, being 96 (93.2%) and 86 (83.5%), respectively. After enrichment culture of 107 cattle specimens in Preston, CEM or Bu 10 broth, the isolation rate on CCDA was also higher (p < 0.01) than that on Butzler agar after enrichment in any medium. These results indicate that CCDA medium is easy to handle without blood and, as to this study shows, is superior to Butzler agar for isolation of Campylobacter species from fecal samples.

[A clinical study of gastrointestinal flora in patients with, or without MRSA colonization in the upper-respiratory tract after introduction of preventive measures of hospital infection]

In early 1980's methicillin-resistant Staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan. At the same time in the A geriatric hospital MRSA infection was prevalent. To decrease nosocomial infections some active preventive measures against hospital infection were taken since Oct. 1991. After introduction of preventive measures of hospital infection in geriatric ward (190 beds) nosocomial bacteremia and pneumonia were markedly decreased in comparison to the episode number before introduction of prevention. However several patients with MRSA colonization were observed every month. The aim of this clinical study was to clear how frequent MRSA was isolated from the gastric juice and stool. Any MRSA was not observed in 63 cultured stool, but just one MRSA was isolated in patients with MRSA colonization. On the other hand gram-negative organisms, which were E. coli, P. aeruginosa, P. mirabilis etc., were frequently observed in cultured stool. In conclusion, we considered frequency of MRSA colonization in gastrointestinal space was not so high but rather very low.

Effect of Guglielmi detachable coils on experimental carotid artery aneurysms in primates

BACKGROUND AND PURPOSE

Clinical experience has established that intravascularly placed metal coils can be a useful treatment for cerebral vascular aneurysms. However, the mechanism by which the coils induce occlusion of the aneurysm is unclear. Appropriate use of this promising treatment modality requires basic understanding of the occlusive process. We used an animal model system of experimentally induced carotid aneurysms to investigate the initial events induced by Guglielmi detachable coils (GDCs), as well as the subsequent vascular changes induced by the coils over time.

METHODS

We induced 23 aneurysms in the carotid arteries of 16 Japanese monkeys. Nineteen aneurysms were then occluded with GDCs placed via endovascular surgery; 4 aneurysms served as controls. We then used gross and microscopic pathological examination, angiography, and scanning electron microscopy to assess the effects of the GDC.

RESULTS

In the first few hours after placement of the GDC in the experimental aneurysms, we observed leukocyte attachment and deposition of fibrinlike materials and other proteins. By 4 days after coil placement, leukocytes and fibroblasts were observed in the thrombus. By 2 weeks after coil placement, there was evidence of an endothelial-like covering of the coils. At 3 months after coil placement, we observed development of an arterial media in the occluded aneurysms.

CONCLUSIONS

The GDCs initiated a cellular response within several hours of aneurysm occlusion. By 2 weeks after coil placement, endothelialization was proceeding, and by 3 months after occlusion, remodeling of the aneurysm had progressed to produce a media-like structure in the former aneurysm.

[A case of thymic squamous cell carcinoma successfully treated with curative resection]

A case of rare thymic squamous cell carcinoma was reported. A 46-year-old female was admitted to our hospital because of an abnormal shadow on chest X-ray. Chest CT showed anterior mediastinal tumor and histological diagnosis of squamous cell carcinoma was made by needle biopsy under CT guide. Esophagus and lung were no abnormal findings, we thought the primary region was thymus. On mid-sternotomy, anterior mediastinal tumor was resected with thymus, right phrenic nerve and pericardium, however it was not direct invasion to heart, great vessels, lung and chest wall. Resection of peripheral fatty tissue and dissection of mediastinal lymph nodes as much as possible, it was not capsular invasion and mediastinal lymph nodes metastasis and complete curative resection was able to perform. Additional radiation therapy was done, post-operative course was uneventful.

An electron microscopic study of the processes of nerve regeneration after lyophilized nerve homografting

The objective of the present study was to investigate the role of the Schwann cell basal lamina in nerve regeneration. To achieve this goal, we observed the process of axonal regeneration within a lyophilized nerve graft, in which only the basal lamina of the Schwann cell persisted. Sciatic nerves were removed from rats and lyophilized to kill the Schwann cells and other components. These grafts were transplanted to rat sciatic nerve defects. The rats were then killed after lapses of time. We observed the processes of axonal regeneration using a transmission electron microscope. Regeneration of axons along the inner surface of the Schwann cell basal lamina was clearly seen. These results suggest that, if tubular basal laminae persist, Schwann cells are not always necessary, and axonal regeneration can be induced in the direction toward the basal lamina.

Protective activity of hamamelitannin on cell damage of murine skin fibroblasts induced by UVB irradiation

The protective activities of hamamelitannin (2',5-di-O-galloyl-hamamelose) in Hamamelis virginiana L. and its related compound, gallic acid, on damaged murine skin fibroblasts induced by UVB irradiation were investigated. In order to exclude the UV absorbing effect of the compounds, the protection study was performed such that the fibroblasts were pretreated with hamamelitannin or gallic acid for 24 h before UVB irradiation. At 200 microM concentration, hamamelitannin gave the higher survival of 72.6 +/- 0.4% in comparison with that of gallic acid (35.5 +/- 1.0%), while UVB absorbers such as 2-ethylhexyl p-methoxycinnamate and hexylbenzoate did not show such protection. The scavenging activities of hamamelitannin and gallic acid against active oxygens such as superoxide anion radicals, hydroxyl radicals and singlet oxygens were evaluated using electron spin resonance (ESR-spin trapping method). Hamamelitannin and gallic acid showed potent scavenging activities against all active oxygens tested. Furthermore, the association of hamamelitannin to fibroblasts was examined by comparing it with that of gallic acid, and the following results were obtained: (1) hamamelitannin reduces the reaction rate of liposome entrapped-nitroblue tetrazolium (NBT) with external superoxide anions, and (2) several glycosides associate with fibroblasts. From these results, it was concluded that hamamelitannin protects murine fibroblasts against external active oxygens by associating with the cell surface through its sugar moiety.

Peroxyl radical scavenging activities of hamamelitannin in chemical and biological systems

The antioxidative activities of hamamelitannin (2',5-di-O-galloyl-hamamelose), gallic acid and dl-alpha-tocopherol against lipid peroxyl radicals were evaluated in chemical and biological systems. The peroxyl radical scavenging activity was evaluated by electron spin resonance (ESR) method in which both spin-trapping and direct reaction methods were used. In the spin-trapping method, as evaluated by 50% inhibition concentration (IC50) of peroxyl radicals generated in a t-butylhydroperoxide-methemoglobin system, hamamelitannin (IC50 = 95.3 +/- 2.7 microM) showed the highest activity, followed by gallic acid (IC50 = 152.8 +/- 14.6 microM) and dl-alpha-tocopherol (IC50 = 221.5 +/- 4.6 microM) as a positive control. When estimating by the direct method, IC50 values of hamamelitannin, gallic acid and dl-alpha-tocopherol were 93.5 +/- 2.1 microM, 141.6 +/- 2.0 microM and 1590.0 +/- 330.0 microM, respectively. On peroxidation of lipid bilayers induced by 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH) in terms of inhibition period (tinh), hamamelitannin showed the longest tinh time (1107.0 +/- 38.18 sec), followed by those of dl-alpha-tocopherol (877.5 +/- 31.8 sec) and gallic acid (771.0 +/- 4.2 sec). The kinetic chain length, defined as the propagation numbers of a lipid peroxyl radical, and calculated from the ratio (Rp/Ri) of the rate of lipid peroxidation to that of inhibition by dl-alpha-tocopherol, hamamelitannin and gallic acid were 27.23, 7.86 and 7.09, respectively. The effects of hamamelitannin, gallic acid and dl-alpha-tocopherol were evaluated on murine fibroblasts exposed to t-butylhydroperoxide (BHP) in terms of the cell survivals. In the protection, hamamelitannin induced the highest survival of 27.6 +/- 0.6% at 50 microM, while both gallic acid and dl-alpha-tocopherol were less active at the same concentrations. On the basis of the results, hamamelitannin was concluded to have a high protective activity on cell damage induced by peroxides.

[Clinical study of radiation pneumonitis over 10 years]

We studied clinical aspects of radiation pneumonitis from 1983 to 1992. Fifty seven patients admitted to our hospital because of lung cancer were treated with radiotherapy, and radiation pneumonitis developed in 20 (35.1%). The incidence of radiation pneumonitis was closely related to male sex, chronic obstructive lung disease, and chemotherapy. Pneumonitis was not related to age, or to the area or amount of radiation. Eighteen cases (90%) of pneumonitis occurred during or within one month after radiotherapy. In all but five cases (25%), pneumonitis was limited to the area of radiation. Treatment was mainly with steroids. In 4 cases (20%), pneumonitis recurred when steroid therapy was reduced, and five patients (10%) died.

[Decrease of nosocomial bacteremia and nosocomial pneumonia after introduction of preventive measures of hospital infection]

In the early 1980's methicillin-resistant staphylococcus aureus (MRSA) was reported as a major pathogenic organism of geriatric hospital infection in Japan. At the same time in the A geriatric hospital MRSA infection was prevalent. To decrease nosocomial infections some active preventive measures against hospital infection were taken since Oct. 1991. About a year before introduction of prevention of hospital infection in the geriatric ward (190 beds) of A hospital 193 episodes of nosocomial bacteremia were observed. However a year after introduction of preventive measures episodes of nosocomial bacteremia were decreased to less than a half (45.6%) in comparison to the number before introduction of prevention. As a causative organism gram-positive bacteria including MRSA were markedly decreased. Major portals of entry of bacteremia (74.9%) were urinary-tract system, intravenous hyperalimentation (IVH) catheter, and pressure sores. MRSA-positive pressure sores were decreased to 20.4% of those before prevention. On the other hand 87 episodes of nosocomial pneumonia were observed before prevention. However a year after introduction of preventive measures episodes of nosocomial pneumonia were decreased to less than a half (44.8%) in comparison to the number before introduction of prevention. After prevention MRSA and mixed infection of P. aeruginosa and MRSA were markedly decreased. The decrease of bacteremia and nosocomial pneumonia were caused by cleaning hands, the preventive measures for decrease and improvement of pressure sores, cleaning the upper respiratory tract for prevention of lower respiratory-tract infection cleaning floors and education of the staff, etc.

Role of cysteine 337 and cysteine 340 in flavoprotein that functions as NADH oxidase from Amphibacillus xylanus studied by site-directed mutagenesis

A flavoprotein from Amphibacillus xylanus catalyzes the reduction of oxygen to hydrogen peroxide. Each polypeptide chain in the tetrameric enzyme contains 5 cysteine residues. The complete reduction of enzyme by dithionite requires 6 electrons. Such behavior indicates the presence of redox centers in addition to the FAD, and these could be disulfides. In order to assess the catalytic role of disulfide in the enzyme, 2 of the cysteines (Cys-337 and Cys-340), which show a high degree of homology with alkyl hydroperoxide reductase F52a protein and thioredoxin reductase, have been changed to serines by site-directed mutagenesis of the cloned flavoprotein gene (individually and in a double mutant). Titration of the three mutant enzymes, lacking Cys-337, Cys-340, or both cysteines, requires only 2 electron eq to reach the reduced flavin state. These results indicate the absence of a redox-active disulfide and demonstrate the involvement of Cys-337 and Cys-340 in the redox-active disulfide. The catalytic activity of the three enzymes was examined by steady-state analysis. The Km for NADH and oxygen and the kcat value of these mutant enzymes were essentially the same as those of wild type. The NADH oxidase activities were also accelerated markedly in the presence of free FAD, which is the case for wild-type enzyme. The NADH:5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) oxidoreductase activities of all mutant enzymes were less than 3% of the activity of wild-type enzyme. The weak DTNB reductase activities in the mutant enzymes lacking Cys-337 or Cys-340 may occur through direct reduction of the mixed disulfide Cys-337-thiol or Cys-340-thiol and nitrothiobenzoate by FADH2. However, the weak DTNB reductase activity in the mutant enzyme lacking both cysteines indicates that FADH2 can reduce either DTNB or another disulfide directly, albeit inefficiently. These results suggest intramolecular dithiol-disulfide interchange reactions in the flavoprotein.

Temperature acclimation induces light meromyosin isoforms with different primary structures in carp fast skeletal muscle

Carp acclimated to 10 degrees C gave 69k, 66k, and 62kDa light meromyosin (LMM) fragments in SDS-PAGE, while fish acclimated to 30 degrees C gave 74k, 69k, 66k, and 62kDa fragments. The microsequence analysis revealed that the 69k and 66kDa components from the 10 degrees C-acclimated carp contained an N-terminal amino acid sequence different from that of 62kDa. The four fragments from the 30 degrees C-acclimated carp showed the same sequence as that of the 69k and 66kDa components from the 10 degrees C-acclimated carp, except that the 2nd amino acid, Ala, of the 10 degrees C-acclimated LMM was replaced by Thr. DNA fragments encoding an N-terminal region of LMM were amplified by PCR or reverse transcriptase-PCR, demonstrating that the two acclimated groups further contained several amino acids substituted.

[A case of primary mediastinal germ cell tumor, successfully treated with chemotherapy and curative resection]

A 20-year-old man was admitted to our hospital because of an abnormal shadow on chest X-ray Laboratory data revealed a high serum alpha-fetoprotein (AFP) and LDH level. Percutaneous needle biopsy of the tumor suggested primary mediastinal germ cell tumor. Curative resection was performed after three courses of combination chemotherapy (cis-platinum, VP-16, bleomycin and adriamycin). A post-operative histological examination of the mass revealed total necrosis. Post-operative course was uneventful, and he has been free of recurrence for the last six months.

Detection of hydrogen peroxide and hydroxyl radicals in murine skin fibroblasts under UVB irradiation

The purpose of this study was to identify the active oxygen species generated in murine skin fibroblasts under UVB irradiation. When fibroblasts were exposed to UV light (UVA + UVB), hydroxyl radicals were detectable by ESR-spin trapping using DMPO as a spin trapping agent. Cell damage induced by UVB irradiation was prevented by addition of DMSO, a typical hydroxyl radical scavenger. Fibroblasts treated with a catalase inhibitor 3-amino-1H-1,2,4-triazole were more sensitive to UVB irradiation than untreated-cells, but the sensitivity was improved by addition of DMSO. To find the origin of the hydroxyl radicals in fibroblasts during UVB irradiation, H2O2 was determined by dihydrorhodamine 123 and it was found that the formation of H2O2 increased under UVB irradiation. These results suggest that UVB-irradiated skin fibroblasts produce H2O2 and were followed by the formation of hydroxyl radicals, probably derived from the Fenton-like reaction (H2O2 + Fe2+ --> .OH + OH- + Fe3+), which in turn damages the cells.

Beta 2-adrenergic receptor regulation of the cardiac L-type Ca2+ channel coexpressed in a fibroblast cell line

To characterize the functional coupling of the beta 2-AR to the cardiac Ca2+ channel in a system with a single receptor subtype, we stably cotransfected a Chinese hamster fibroblast (CHW) cell line, which lacks beta 2-ARs and Ca2+ channels, with the rabbit cardiac Ca2+ channel alpha 1 and beta 2 subunits and the human beta 2-AR cDNAs. The effects of beta 2-AR stimulation on the expressed Ca2+ channel current were examined using the whole-cell patch-clamp technique. CHW cells transfected with the Ca2+ channel subunits displayed a voltage-dependent inward current having properties typical of native cardiac L-type Ca2+ channels. The expressed current was increased by a phosphorylation-dependent mechanism. CHW cells cotransfected with the Ca2+ channel subunits and the beta 2-AR were responsive to isoproterenol (Iso) in a dose-dependent manner. Iso (10 microM) increased peak Ca2+ channel current to 172 +/- 5% (n = 17) of control amplitude, indicating that the expressed Ca2+ channels are functionally coupled to the beta 2-AR. The results demonstrate unequivocally that beta 2-ARs can modulate the activity of cardiac Ca2+ channels, independent of beta 1-ARs. The results also demonstrate the usefulness of the CHW heterologous expression system, the first to reconstitute physiological modulation of an L-type Ca2+ channel by the beta 2-AR, for studying receptor subtype-specific regulation of the Ca2+ channel.

Active-oxygen scavenging activity of plant extracts

To find antioxidative compounds present in plants, 65 types of plant extract were tested using the neotetrazolium method for evidence of superoxide anion-scavenging effects and 7 plant extracts were selected for further investigation. The activity of active-oxygen scavengers such as superoxide anion radicals, hydroxyl radicals, singlet oxygens and lipid peroxides in the 7 plant extracts (Aeseclus hippocastanum L., Hamamelis virginiana L. Polygonum cuspidatum Sieb., Quercus robur L., Rosemarinous officinalis L., Salvia officinalis L. and Sanguisorba officinalis L.) was examined in detail by both ESR spin-trapping and malondialdehyde generation. Furthermore, the active-oxygen scavenging activity of these plant extracts was evaluated using a murine dermal fibroblast culture system. Both Aeseclus hippocastanum L. and Hamamelis virginia L. were found to have strong active-oxygen scavenging activity of and protective activity against cell damage induced by active oxygen. Both Aeseclus hippocastanum L. and Hamamelis virginiana L. are proposed as potent plant extracts with potential application as anti-aging or anti-wrinkle material for the skin.

[Alexia-agraphia of kanji (Japanese morphogram) after left posterior-inferior temporal lesion]

Several cases of selective alexia with agraphia of kanji have been reported in Japan in this decade. It is well known that the lesion in the posterior inferior temporal lobe of the dominant hemisphere is responsible for this cognitive syndrome. Neuropsychological data in our patient suggest that the postero-inferior region of the temporal lobe of the dominant hemisphere may be the visuo-verbal association area for the analysis of the complex visuo-verbal information. The symptoms caused by the same lesion in western patients might be subangular alexia (alexia without agraphia). Alexia with agraphia of kanji and subangular alexia would appear to be distinct entities, but a dual processing hypothesis of visuo-verbal information and the concept of the visuo-verbal association area might well explain both syndromes.

Protective activity of hamamelitannin on cell damage induced by superoxide anion radicals in murine dermal fibroblasts

Previously we demonstrated that hamamelitannin (2',5-di-O-galloyl hamamelose) in Hamamelis virginiana L. exhibits potent superoxide-anion scavenging activity. We then examined the physiological and pharmacological activities of hamamelitannin as well as its functional homologues, gallic acid and syringic acid. The following results were obtained: (1) Hamamelitannin has a higher protective activity against cell damages induced by superoxide anions than gallic acid which is the functional moiety of hamamelitannin. The protective activity of hamamelitannin on murine fibroblast-damage induced by superoxide anions was found at a minimum concentration of 50 microM, while the corresponding figure for gallic acid was 100 microM. (2) Pre-treatment of fibroblasts with hamamelitannin enhances cell survival. (3) The superoxide-anion scavenging activity of the compound in terms of its IC50 value (50% inhibition concentration of superoxide anion radicals generated) was evaluated by ESR spin-trapping. Both hamamelitannin (IC50 = 1.31 +/- 0.06 microM) and gallic acid (IC50 = 1.01 +/- 0.03 microM) exhibited high superoxide-anion scavenging activity followed by syringic acid (IC50 = 13.90 +/- 2.38 microM). (4) When hamamelitannin was treated with superoxide anions generated by a KO2-crown ether system, HPLC analysis showed the disappearance of hamamelitannin and the concomitant formation of hamamelitannin-derived radicals (g = 2.005, delta H1 = 2.16 G, delta H2 = 4.69 G) was detected by ESR spectrometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Purification and analysis of a flavoprotein functional as NADH oxidase from Amphibacillus xylanus overexpressed in Escherichia coli

The gene encoding the Amphibacillus xylanus flavoprotein has been cloned into pTTQ18 and overexpressed in Escherichia coli. The recombinant enzyme has been purified to homogeneity yielding 15 mg of pure enzyme/liter of cell culture. Recombinant flavoprotein is fully active and has an absorption spectrum identical to that of the enzyme purified from A. xylanus. The N-terminal sequence analysis and analytical gel filtration data confirm the structural identity of recombinant and A. xylanus enzymes. The Km value for oxygen and the Km value for NADH are 1.7 mM and 33.3 microM, respectively. In the presence of free additional FAD, however, the Km value for oxygen decrease dramatically. The NADH oxidase activity is accelerated markedly in the presence of additional FAD. The intracellular free FAD concentration of A. xylanus is calculated about 13 microM. This FAD concentration would be enough to accelerate the NADH oxidase activity of flavoprotein in cells of A. xylanus. Two-electron reduction of the enzyme FAD by the strong reductant dithionite occurs during the total uptake of 6 electrons. Such behavior usually indicates the presence of non-flavin redox centers. The high degree of homology between this enzyme and alkyl hydroperoxide reductase F52a protein and thioredoxin reductase suggests that these centers are the redox-active disulfide adjacent to the FAD and another disulfide, which is able to slowly interchange with the redox-active disulfide. The presence of two disulfides has been demonstrated.

cAMP responsive element-mediated regulation of the gene transcription of the alpha 1B adrenergic receptor by thyrotropin

To elucidate the molecular mechanism of the stimulatory effect of thyrotropin on the gene regulation of alpha 1B adrenergic receptor in functioning rat thyroid (FRTL-5) cells, we established a competitive reverse-transcriptase (RT) polymerase chain reaction (PCR) and nuclear run-off assay to quantify changes in mRNA levels and transcription rates. A binding assay showed that FRTL-5 cells predominantly expressed alpha 1B adrenergic receptor and that thyrotropin increased its expression sevenfold. By means of RT-PCR, we found that thyrotropin induced an 11-fold increase in alpha 1B receptor mRNA abundance. The nuclear run-off assay demonstrated that thyrotropin caused a ninefold increase at the gene transcriptional level, which occurred in the presence of the protein synthesis inhibitor cycloheximide. The half-life of the alpha 1B receptor mRNA in cells incubated with thyrotropin for 1 h increased 1.5-fold but returned to the original value after 12 h. Dibutyryl cAMP and forskolin mimicked the stimulatory effects of thyrotropin on the gene transcriptional level. The 5'-flanking region of the rat alpha 1B receptor gene contained a putative cAMP responsive element (CRE) at nucleotide -438 relative to the translation start site. The promoter analysis using the reporter gene indicated that the CRE motif confers the cAMP sensitivity to the transcription of the rat alpha 1B receptor gene. These results demonstrated that a CRE-mediated mechanism is involved in the transcriptional regulation of the alpha 1B receptor gene by thyrotropin without requiring new protein synthesis.

Construction of squalene-accumulating Saccharomyces cerevisiae mutants by gene disruption through homologous recombination

Saccharomyces cerevisiae synthesizes ergosterol via squalene, but squalene is hardly detected in aerobically grown cells. To obtain a stable squalene-accumulating yeast strain, we attempted to disrupt a gene required in the conversion of squalene to ergosterol, by homologous recombination with a short piece of the gene fragment conjugated with an integration plasmid vector carrying the LEU2 gene. Two mutants that required ergosterol at least for fast growth were isolated. In an aerobic cultivation and with ergosterol supplementation, the two mutants accumulated squalene up to 5 mg/g dry cells. Southern hybridization analysis indicated that both mutants had acquired the vector DNA integrated in the same gene, or nearby genes, on chromosome 12.

Expression of fimbriae and host response in Branhamella catarrhalis respiratory infections

Sputum during the acute exacerbation of chronic respiratory diseases were observed under the electron microscope, to determine the in vivo expression of surface structures of Branhamella catarrhalis (B. catarrhalis), the polymorphonuclear neutrophil (PMN) response to B. catarrhalis infections, and the composition of sputum. It was found that during infection fimbriae are expressed in B. catarrhalis. However, there were sparsely to densely fimbriated bacteria in each sputum sample. The length of the fimbriae were from 50 to 76 nm. In the sparsely fimbriated B. catarrhalis, external to the cell wall, a thin, granular, electron-dense layer was observed. Due to the presence of fimbriae, this layer was not seen in densely fimbriated B. catarrhalis. Blebs were also found in B. catarrhalis. PMNs were found to phagocytose both B. catarrhalis and debris. Evidence was found that debris were formed mainly by the destruction of PMNs. Bacteria as well as debris were phagocytosed by PMNs.

A model system for the continuous production of a heterologous protein using a novel secretion promoting factor which operates in Escherichia coli

The 'PAS factor' whose gene has been cloned from a species of Vibrio, is a novel protein secretion factor which is functional in Escherichia coli cells. To demonstrate that practical use of the PAS factor gene is possible, we have constructed a model secretion vector 'pAS23'. Using this system, beta-lactamase was produced and secreted into the medium of a continuous culture system, after optimization of culture conditions.

Detection of minimal residual disease using clonospecific primers for CDRIII in patients with acute B lymphocytic leukemia with or without Philadelphia chromosome: possibility of clinical application as a tool for improving prognosis

We attempted to identify the minimal residual leukemic clone as related to the clinical course in patients with acute B lymphocytic leukemia (B-ALL). DNA was extracted from stored bone marrow slides, and the third complementarity determining region (CDRIII) was amplified by polymerase chain reaction (PCR) using primers with consensus sequences for VH and JH. After amplification of the CDRIII band, the DNA fragment of CDRIII was inserted into the cloning vector PUC118. After cloning, the DNA sequences for CDRIII were determined. Clonospecific DNA sequences in CDRIII were selected, and clonospecific primers for each patient were synthesized. Using the clonospecific primers, we carried out second-round PCR to detect minimal residual disease (MRD) during several stages of the clinical course. Basically, the sensitivity of detection for MRD was between 10(-4) and 10(-5) cells. Even when leukemic cells were not detected in the morphologic study, with this detection system, the MRD was identified as an amplified CDRIII band stained with ethidium bromide on agarose gel. After bone marrow transplantation (BMT), MRD was detected for at least 4 months. In this article, we discuss the difference in sensitivity of detection for MRD between the BCR-ABL fusion gene and CDRIII in Philadelphia chromosome-positive (Ph+) B-ALL, as well as the possible clinical application of this method to predict relapse and prognosis.

[Reoperation after open mitral commissurotomy for mitral stenosis]

Between 1975 and 1993, 16 of 95 patients who received open mitral commissurotomy for mitral stenosis required reoperation for recurrent mitral lesions with a mean duration of 11 years after the initial operation at Kawasaki Medical School Hospital. The mitral lesions necessitating reoperation involved restenosis in eight, stenoinsufficiency in six and regurgitation in two. In 13 patients, mitral commissure was well separated, and the mitral restenosis and regurgitation were caused by progressions of valvular and subvalvular lesions. Significant tricuspid valve regurgitation was also seen in nine patients, and in seven out of eight patients who were in NYHA functional class III or IV, tricuspid regurgitation of grade 3 was observed. The combined tricuspid regurgitation aggravated the patient's symptoms and became a major risk factor of the reoperation after open mitral commissurotomy.

Dynamic arterial baroreflex in rabbits with heart failure induced by rapid pacing

Excessive sympathetic nerve activity in heart failure could be attributable to impaired arterial baroreflex function. Employing transfer function analysis, we evaluated the arterial baroreflex in control rabbits (n = 8) and in rabbits with rapid pacing-induced heart failure (n = 10) in a dynamic manner. Rabbits in the heart-failure group showed elevated filling pressures, depressed first derivative of left ventricular pressure, pulmonary congestion, and an increased level of plasma norepinephrine. Varying aortic pressure pseudorandomly and recording responses in renal nerve activity, we calculated the transfer function from aortic pressure to renal nerve activity. The gain of the transfer function was similar between control and heart-failure rabbits over 0.04-0.4 Hz as well as the phase and the coherence, indicating that the dynamic arterial baroreflex was preserved in our rabbit heart-failure model. Vagotomy increased the gain of the arterial baroreflex over 0.04-0.4 Hz in control (P < 0.05) but not in heart-failure rabbits, indicating that vagal afferents, which normally inhibit the dynamic arterial baroreflex, no more did so in heart failure. We conclude that excessive sympathetic nerve activity in heart failure may not be due to impaired dynamic arterial baroreflex, but that this apparently preserved arterial baroreflex in heart failure may be due to impaired cardiopulmonary baroreflex.

A novel protein secretion factor from a Vibrio species which operates in Escherichia coli

A DNA fragment specific to a Vibrio species was found to promote extracellular secretion of proteins, when cloned into Escherichia coli. Cells harboring a plasmid carrying this fragment secreted significant amounts of periplasmic beta-lactamase and alkaline phosphatase into the medium, however most cytoplasmic beta-galactosidase was retained within the cell. The DNA sequence essential for this property was found to be a gene encoding 76 amino acids, which was designated as the 'PAS factor'. Highly expressed PAS factor is harmful to the cell, this may be due to a disruption of the membrane structure and/or function.

[A case of hypertrophic obstructive cardiomyopathy (HOCM) complicated by infective endocarditis (IE) and mitral regurgitation (MR)]

The case of a 56-year-old man who underwent mitral valve replacement due to HOCM complicated by IE and MR is reported. Preoperative 2D echocardiographic assessment of the mitral valve revealed systole anterior motion (SAM) and vegetation, and color flow Doppler echocardiographic examination revealed severe mitral regurgitation. The left ventricular out-flow tract gradient decreased from 140 mmHg preoperatively to 60 mmHg postoperatively. Mitral valve replacement should be considered in patients with associated IE and severe MR.

Cloning of a new cryIA(a) gene from Bacillus thuringiensis strain FU-2-7 and analysis of chimaeric CryIA(a) proteins for toxicity

We cloned the cryIA(a) gene from Bacillus thuringiensis strain FU-2-7, one of the toxin genes encoding lepidopteran-specific protoxins. Sequence analysis of the gene showed two amino acid differences (Pro77 to Leu and Phe965 to Ser) from the CryIA(a) of B. thuringiensis strain HD-1. We constructed chimaeric cryIA(a) genes using FU-2-7 and HD-1 cryIA(a) genes and isolated the chimaeric protoxins, as well as the parental ones, from Escherichia coli cells harboring the recombinant plasmids to examine the effects of the two amino acid variations on the toxicity. FU-2-7 CryIA(a) protein was about half as toxic against the smaller tea tortrix, Adoxophyes sp., and one-third as toxic against the silkworm, Bombyx mori, as that of HD-1. On the other hand, a chimaeric CryIA(a) protein with a single replacement of Phe965 to Ser had nearly the same toxicity as the HD-1 CryIA(a) against the smaller tea tortrix and one-third the toxicity against silkworm as that of HD-1. This improved property of the chimaeric CryIA(a) protoxin may be useful for widening its application to crop protection in sericultural countries.

Influence of arotinolol hydrochloride on heart rate spectrum in hypertensive subjects

Influence of arotinolol hydrochloride and atenolol on the balance between the sympathetic and parasympathetic nervous systems was evaluated in 8 hypertensive subjects by spectral analysis of heart rate (HR) and systemic blood pressure (BP). Before and after administration of either arotinolol (n = 7) or atenolol (n = 7) for 2 weeks, BP was continuously and non-invasively monitored by a finger-cuff manometry (Finapres). A time series of instantaneous HR was constructed from the BP signal. A time series of mean BP was also constructed. Spectral analysis was performed by the use of an autoregressive algorithm on these time series (approximately 180 sec). Each spectrum was subdivided into low-(0.05-0.15 Hz, LF) and high-frequency (0.15-0.4 Hz, HF) components, and each component was divided by the sum of the two for normalization. As a measure of the balance between the sympathetic and parasympathetic nervous systems, the ratio of LF to HF (LF/HF) was evaluated. Arotinolol increased fractional HF in the HR spectrum from 0.45 +/- 0.12 to 0.73 +/- 0.08 (p < 0.01) and decreased fractional LF from 0.55 +/- 0.12 to 0.27 +/- 0.08 (p < 0.01); consequently, it decreased LF/HF from 1.4 +/- 0.5 to 0.4 +/- 0.2 (p < 0.01). Atenolol had similar effects on these parameters. Neither of these beta-adrenergic blockades produced a discernible decrease in LF/HF in the BP spectrum. In conclusion, these beta-adrenergic blockades decreased LF/HF in the HR spectrum in hypertensive subjects, which suggests that they improved the balance between the sympathetic and parasympathetic nervous systems.

[Clinical significance of positive blood cultures in the Nagasaki Rosai Hospital during the past 6 years]

In this clinical study we tried to find out the clinical significance of positive blood cultures between Jan. 1984 and Dec. 1989 in the Nagasaki Rosai Hospital. In this period the association between the isolated bacteria from blood cultures (398 specimens: 17.9%) and clinical background were evaluated. Each year the positive cultures were seen in about 18-20%. The distribution of bacteria showed increase percentage of the gram-positive organisms such as coagulase-negative Staphylococcus. Gram-negative organisms in included P. aeruginosa, A. calcoaceticus and E. coli. A. calcoaceticus was frequently found from the dept. of neurosurgery. Fungus, mostly Candida, was isolated in about 10-20%. The specimens were provided from department of internal medicine (62.9%) and neurosurgery (22.8%). An analysis of 213 episodes of 188 bacteremic cases was made. The onset of bacteremia had two peaks, 24 h or 1 month, after admission. The primary infected sites were the urinary tract (26.7%), respiratory system (14.5%) and central nervous system (6.1%). The central venous catheter was an important infected site. The major underlying diseases included acute cerebrovascular diseases, cardiac failure due to valvular heart diseases or acute myocardial infarction and/or iatrogenic immunocompromised state. The major complications were disseminated intravascular coagulation (DIC) (24.4%) and multiple organ failure (MOF) (8.9%). Half of the DIC episodes was caused by gram-positive cocci such as CNS, E. faecalis and MRSA. 68.4% of MOF episodes was associated with gram-negative bacteria. While the remainder was caused by gram-positive cocci including CNS and MRSA.(ABSTRACT TRUNCATED AT 250 WORDS)

Replacement of an amino acid residue of cyclodextrin glucanotransferase of Bacillus ohbensis doubles the production of gamma-cyclodextrin

Cyclodextrin glucanotransferase (CGTase; EC 2.4.1.19) produces cyclodextrin (CD) from starch through an intramolecular transglucosylation reaction. To obtain a better understanding of the amylolytic and cyclization mechanisms of CGTase, and furthermore to improve the production of gamma-CD, mutant CGTases were constructed by site-directed mutagenesis of the CGTase gene of Bacillus ohbensis replacing Tyr at position 188 by 19 other amino acids. All mutant enzymes retained both starch-degrading and CD synthesizing activities to various extents. Among them, a mutant enzyme having Trp instead of Tyr-188 produced 15% of gamma-CD from soluble starch, which is about twice as much as the amount produced by the wild-type enzyme.

Cloning, sequencing, and expression of thermophilic Bacillus sp. strain TB-90 urease gene complex in Escherichia coli

The urease of thermophilic Bacillus sp. strain TB-90 is composed of three subunits with molecular masses of 61, 12, and 11 kDa. By using synthetic oligonucleotide probes based on N-terminal amino acid sequences of each subunit, we cloned a 3.2-kb EcoRI fragment of TB-90 genomic DNA. Moreover, we cloned two other DNA fragments by gene walking starting from this fragment. Finally, we reconstructed in vitro a 6.2-kb DNA fragment which expressed catalytically active urease in Escherichia coli by combining these three DNA fragments. Nucleotide sequencing analysis revealed that the urease gene complex consists of nine genes, which were designed ureA, ureB, ureC, ureE, ureF, ureG, ureD, ureH, and ureI in order of arrangement. The structural genes ureA, ureB, and ureC encode the 11-, 12-, and 61-kDa subunits, respectively. The deduced amino acid sequences of UreD, UreE, UreF, and UreG, the gene products of four accessory genes, are homologous to those of the corresponding Ure proteins of Klebsiella aerogenes. UreD, UreF, and UreG were essential for expression of urease activity in E. coli and are suggested to play important roles in the maturation step of the urease in a co- and/or posttranslational manner. On the other hand, UreH and UreI exhibited no significant similarity to the known accessory proteins of other bacteria. However, UreH showed 23% amino acid identity to the Alcaligenes eutrophus HoxN protein, a high-affinity nickel transporter.

A flavoprotein functional as NADH oxidase from Amphibacillus xylanus Ep01: purification and characterization of the enzyme and structural analysis of its gene

Amphibacillus xylanus Ep01, a facultative anaerobe we recently isolated, shows rapid aerobic growth even though it lacks a respiratory pathway. Thus, the oxidative consumption of NADH, produced during glycolysis and pyruvate oxidation, should be especially important for maintenance of intracellular redox balance in this bacterium. We purified a flavoprotein functional as NADH oxidase from aerobically growing A. xylanus Ep01. The A. xylanus enzyme is a homotetramer composed of a subunit (M(r) 56,000) containing 1 mol of flavin adenine dinucleotide. This enzyme catalyzes the reduction of oxygen to hydrogen peroxide with beta-NADH as the preferred electron donor and exhibits no activity with NADPH. The flavoprotein gene of A. xylanus Ep01 was cloned by using a specific antibody. The amino acid sequence of 509 residues, deduced from the nucleotide sequence, showed 51.2 and 72.5% identities to the amino acid sequences of alkyl hydroperoxide reductase from Salmonella typhimurium and NADH dehydrogenase from alkalophilic Bacillus sp. strain YN-1, respectively. Bacillus spp. have a respiratory chain and grow well under aerobic conditions. In contrast, Amphibacillus spp., having no respiratory chain, grow equally well under both aerobic and anaerobic conditions, which distinguishes these two genera. Salmonella spp., which are gram-negative bacteria, are taxonomically distant from gram-positive bacteria such as Bacillus spp. and Amphibacillus spp. The above findings, however, suggest that the flavoprotein functional as NADH oxidase, the alkyl hydroperoxide reductase, and the NADH dehydrogenase diverged recently, with only small changes leading to their functional differences.

The three-dimensional structure of the colicin E3 immunity protein by distance geometry calculation

The three-dimensional solution structure of the colicin E3 immunity protein (84 residues) was determined by distance geometry calculations. The hydrophilic side of a four-stranded antiparallel beta-sheet constitutes a part of the surface of the protein, and two loops lie on the hydrophobic side of the sheet. All the three specificity-determining residues, which are included in the center of the beta-sheet, display their side groups on the protein surface.

Developmental process: family caregivers of demented Japanese

1. Developmental process of caring for demented elders: the case of family caregivers consists of the beginning process (stage 1 through 4) and the awakening process (stage 5 through 7). 2. In the beginning process, the caregiver is unaware of the interaction between him/her and the demented family member, relies on conventional, general-purpose methods of care and on verbal communication, and consider care in terms of training and discipline of the person cared for. 3. The caregiver in the awakening process has realized that there is interaction between him/her and the demented family member, reflects on the nonverbal signs shown by the elder in order to improve their care, and provide warm and considerate care by making the most of nonverbal communication.

Correlation of orbital muscle changes evaluated by magnetic resonance imaging and thyroid-stimulating antibody in patients with Graves' ophthalmopathy

To evaluate the relationship between eye changes and autoantibody to the thyrotropin receptor in patients with Graves' disease, we evaluated the eye changes using magnetic resonance imaging and the results were correlated with thyroid-stimulating antibody, thyrotropin binding inhibitor immunoglobulin and thyroid growth activity. Subjects were 15 patients with Graves' disease who had Graves' ophthalmopathy, including exophthalmos and other signs and symptoms, and nine patients without ophthalmopathy; all were maintained in a euthyroid state by antithyroid drugs. The thyrotropin-binding inhibitor immunoglobulin was measured by a kit, and thyroid-stimulating antibody and thyroid growth activity were evaluated by cyclic adenosine 3',5'-monophosphate production and [3H]thymidine incorporation, respectively, by cultured functional rat thyroid lined cells. The sum of the swelling ratios (muscle thickness to the diameter of the optic nerve) of the four extraocular muscles correlated well with the degree of exophthalmos. The thyrotropin-binding inhibitor immunoglobulin was positive in nine out of 15 patients with ophthalmopathy; however, no correlation was observed between the activity and exophthalmos or muscle swelling. No significant correlation was observed between muscle changes and thyroid growth activity either. On the other hand, thyroid-stimulating antibody (642 +/- 91%) in Graves' patients with ophthalmopathy was significantly (p < 0.02) higher than that (315 +/- 84%) in patients without ophthalmopathy. Moreover, the level of stimulating activity in Graves' patients with ophthalmopathy showed a significant (p < 0.02) positive correlation with the sum of the swelling ratios of the individual eight eye muscles. These results suggest that thyroid-stimulating antibody has a close relation to Graves' ophthalmopathy.

Mutational analysis of the amino acid residues essential for the cis and trans cleavage activity of the potato virus Y 50-kDa protease

To examine the proteolytic activities of various truncated derivatives of the potato virus Y (PVY) 50-kDa protease, the derivatives were expressed in Escherichia coli in polyprotein forms fused with coat protein (CP). For the intermolecular cleavage reaction, the truncated proteases were expressed together with the substrate protein containing the polymerase-CP junction. The activity was evaluated by the amount of the mature CP released from the precursor by the intra- and intermolecular cleavage occurring in E. coli. By this experiment, we identified the moiety responsible for the proteolytic activity of the 50-kDa protease to be a 26-kDa polypeptide mapped to the C-terminal half of the protease. Introduction of His234-->Tyr, Asp269-->Asn, or Cys339-->Gly substitution in the putative catalytic triad of the protease abolished its activity. However, the mutated protease with Cys339-->Ser replacement retained a reduced proteolytic activity.

Neutrophil response to Pseudomonas aeruginosa in respiratory infection

Sputum from patients with acute exacerbation of respiratory infection by Pseudomonas aeruginosa was observed under the electron microscope. External to the cell wall of P. aeruginosa a granular, electron-dense material was observed which is suggestive of capsule. It is supposed that stabilization of capsule occurred by the host antibody, which was produced due to chronic infection by P. aeruginosa. Mucoid type of microcolonies were observed with a fibrous matrix of exopolysaccharide. Other types of microcolonies were surrounded by granular substances or fine fibers. Neutrophil was found to be partially surrounding the microcolony in an attempt to defense. Debris was formed mainly by the destruction of the neutrophil. Most neutrophils were found full of phagocytosed debris; in contrast only a few neutrophils were found to have phagocytosed P. aeruginosa. This study concludes that instead of phagocytosing bacteria, neutrophil phagocytosed debris and bacteria were not completely eradicated. Therefore, this might be one of the factors in the pathogenesis of respiratory infection and persistent colonization by P. aeruginosa.

Intra-arterial infusion of insulin attenuates vasoreactivity in human forearm

Hyperinsulinemia may contribute to the development of hypertension. The aim of the present study was to determine whether hyperinsulinemia modulates vascular reactivity to phenylephrine or angiotensin II. In 10 young, healthy volunteers, the left brachial artery was cannulated for drug infusion and direct measurements of arterial pressure. We measured forearm blood flow by a strain-gauge plethysmograph while infusing phenylephrine (0.2, 0.8, and 2.4 micrograms/min) and angiotensin II (5, 10, and 20 ng/min) locally into the brachial artery before and during simultaneous intra-arterial infusion of insulin (0.15 mU/kg per minute). Forearm vascular resistance was calculated from directly measured arterial pressure and forearm blood flow. Intra-arterial infusion of insulin raised the local plasma insulin level from 10.3 +/- 1.4 to 133.3 +/- 21.1 microU/mL (P < .01) and did not change blood glucose level in the venous effluents of the forearm. Insulin infusion slightly but not significantly increased basal forearm blood flow (4.6 +/- 1.5 to 5.5 +/- 0.9 mL/min per 100 milliliters, NS) and decreased forearm vascular resistance (22.1 +/- 2.1 to 20.3 +/- 2.8 U, NS). Phenylephrine and angiotensin II increased forearm vascular resistance dose dependently before and during simultaneous insulin infusion (P < .01 for both). Intra-arterial infusion of insulin attenuated vascular reactivity to phenylephrine (P < .01) and angiotensin II (P < .01). None of these drugs changed blood pressure or heart rate. Our results suggest that hyperinsulinemia attenuates vascular reactivity in the forearm resistance vessels in healthy humans.

[Support techniques in the surgical treatment of aneurysms of the aortic arch]

During the last 15 years, we operated 25 patients of aneurysm of the aortic arch. From 1977 to 1990, various support techniques combined with extracorporeal circulation and carotid bypass were used but from 1990 extracorporeal circulation with selective cerebral perfusion was employed, and so postoperative brain damage was decreased from 47% to 10% (p = 0.05) and operative mortality from 53% to 10% (p = 0.03). We now consider that extracorporeal circulation with selective cerebral perfusion is the best method for cerebral protection in the operation of aneurysms of the aortic arch.