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Biomedical subjects

M Ando

Publications and source records attributed to M Ando.

At least 127 records · Page 7Linked to original sources
PubMed2000

Retrograde cerebral perfusion in human brains.

Retrograde cerebral perfusion via the superior vena cava during deep hypothermic circulatory arrest has evolved as a means of cerebral protection in aortic-arch surgery. We showed, with use of fluorescein retinal angiography, that during retrograde cerebral perfusion, fluorescein injected into the superior vena cava entered the retinal venules, flowed to the capillaries, and subsequently, to the retinal arterioles. Since the retina is embryologically part of the brain, we conclude that this procedure does allow blood to perfuse in a retrograde way through the human brain.

Adult↗
PubMed2000

Mechanism of anemia associated with autonomic dysfunction in rats.

The aim of this study was to elucidate the mechanism of anemia associated with autonomic dysfunction in rats. Using 6-hydroxydopamine (6-OHDA)-treated sympathectomized rats, changes in systolic blood pressure, plasma catecholamine levels, hemograms, erythropoietin (EPO) secretion, and beta-adrenergic receptors on erythrocytes were monitored, and compared with desipramine- and 6-OHDA-treated, and control rats. In 6-OHDA-treated rats, systolic blood pressure and plasma catecholamine levels significantly decreased from 7 days after 6-OHDA administration, returning to the control values on day 28. Hemoglobin (Hb), hematocrit (Hct) and red blood cell (RBC) levels significantly decreased from day 14 to day 28, and reached normal values after day 35, but neither corpuscular constants nor white blood cell (WBC) levels changed after anemia occurred. Administration of desipramine 1 day before 6-OHDA injection prevented anemia. EPO levels did not elevate, even after bloodletting to load anemia, and the EPO circadian rhythm was irregular in 6-OHDA-treated rats. beta-adrenergic receptors measured using 125I-cyanopindolol (CYP) significantly decreased from day 7 to day 28, and reached normal values after day 35. These results suggest that irregular EPO secretion via disordered autonomic nerves may induce anemia in patients with autonomic disorders.

Adrenergic beta-Antagonists↗
PubMed2000

Determination of cytochrome P450 1A activities in mammalian liver microsomes by high-performance liquid chromatography with fluorescence detection.

A sensitive method for the determination of cytochrome P450 (P450 or CYP) 1A activities such as ethoxyresorufin O-deethylase (EROD) and methoxyresorufin O-demethylase (MROD) in liver microsomes from human, monkey, rat and mouse by high-performance liquid chromatography with fluorescence detection is reported. The newly developed method was found to be more sensitive than previous methods using a spectrofluorimeter and fluorescence plate reader. The detection limit for resorufin (signal-to-noise ratio of 3) was 0.80 pmol/assay. Intra-day and inter-day precisions (expressed as relative standard deviation) were less than 6% for both enzyme activities. With this improved sensitivity, the kinetics of EROD and MROD activities in mammalian liver microsomes could be determined more precisely. EROD activities in human and monkey liver microsomes, and MROD activities in liver microsomes from all animal species exhibited a monophasic kinetic pattern, whereas the pattern of EROD activities in rat and mouse liver microsomes was biphasic. In addition, the method could determine the non-inducible and 3-methylcholanthrene-inducible activities of EROD and MROD in rat and mouse liver microsomes under the same assay conditions. Therefore, this method is applicable to in vivo and in vitro studies on the interaction of xenobiotic chemicals with cytochrome CYP1A isoforms in mammals.

Animals↗
PubMed2000

Santonin-related compound 2 inhibits the expression of ICAM-1 in response to IL-1 stimulation by blocking the signaling pathway upstream of I kappa B degradation.

Santonin-related compounds (SRCs) were synthesized from the starting material L-alpha-santonin and tested for the biological activity on the expression of intercellular adhesion molecule-1 (ICAM-1) in response to IL-1 stimulation on human adenocarcinoma cells. One of the bromoketone derivatives termed SRC2 [11S-2 alpha-bromo-3-oxoeudesmanno-13,6 alpha-lactone] strongly inhibited the ICAM-1 expression at an IC(50) value of 5.9 microM, whereas L-alpha-santonin itself was totally inactive up to 100 microM. The blockage of ICAM-1 expression by SRC2 was not due to the direct inhibition of de novo RNA and protein synthesis. The nuclear translocation of NF-kappaB subunit p65 was markedly prevented by SRC2. Moreover, I kappa B alpha degradation upon IL-1 stimulation was strongly inhibited by SRC2. These observations suggest that SRC2 blocks the IL-1 signaling pathway upstream of I kappa B degradation.

Biological Transport↗
PubMed2000

Rapid morphological oscillation of mitochondrion-rich cell in estuarine mudskipper following salinity changes.

Morphological changes in the chloride cells or mitochondrion-rich (MR) cells in the skin under the pectoral fin of the estuarine mudskipper (Periophthalmus modestus) were examined in relation to intertidal salinity oscillation in river mouth. MR cells were distinguished between those in contact with the water (cells labeled with both mitochondrial probe DASPEI and Concanavalin-A, an apical surface marker of MR cells) and those that are not (DASPEI-positive only). After transfer of the fish from seawater to freshwater, no difference in the total MR cell density was observed, but the subpopulation of MR cells that are Concanavalin-A-positive decreased dramatically within 30 min. After 6 hr in freshwater, the fish were returned to seawater; the number of Con-A-positive MR cells increased to the initial levels rapidly. Thus, in seawater, mudskippers seem to open the apical crypts of the MR cells to secrete salt; in freshwater, they close the crypt of the MR cells tentatively, and tolerate hypotonicity until the rising tide. This unique response of chloride cells may also be seen in gills of other estuarine species.

Adaptation, Physiological↗
PubMed2000

mRNA encoding 'ClC-K1, a kidney Cl(-)- channel' is expressed in marginal cells of the stria vascularis of rat cochlea: its possible contribution to Cl(-) currents.

The cochlear stria vascularis is essential for the normal function of hair cells. mRNA encoding the ClC-K1 Cl(-) channel, previously thought to be found only in the kidney, was detected in epithelial marginal cells of the rat stria vascularis by single cell RT-PCR. When Cl(-) currents were recorded from rat marginal cells by the whole-cell patch clamp method, the steady-state currents showed weak outward rectification and an ion selectivity sequence of SCN(-)Br(-)=Cl(-)F(-)NO(3)(-)I(-)gluconate(-). The Cl(-) currents were regulated by extracellular Ca(2+) and pH. These characteristics resemble those reported for the currents recorded from Xenopus oocytes expressing ClC-K1 Cl(-) channels. These data together suggest that ClC-K1 Cl(-) channels may contribute to the whole-cell currents of marginal cells.

Animals↗
PubMed2000

Oxidative injury is present in Purkinje cells in patients with olivopontocerebellar atrophy.

To verify the presence of lipid peroxidation products in spinocerebellar degeneration (SCD), the cerebella from eight patients with olivopontocerebellar atrophy (OPCA) and six non-OPCA patients were immunohistochemically investigated with 4-hydroxy-2-nonenal (HNE) antibody. On average, 84.6% of Purkinje cells were positively or strongly positively immunostained in OPCA patients while only 15.5% were positive in non-OPCA patients. Other cells in the molecular and granular layers showed no obvious immunoreactivity. These data suggest that a lipid peroxidation product is present in Purkinje cells of OPCA patients and that oxidative stress may play an important role in the degeneration process of SCD.

Aged↗
PubMed2000

Effect of sildenafil citrate (Viagra) on erectile dysfunction in a patient with familial amyloidotic polyneuropathy ATTR Val30Met.

A 34-year-old male patient with familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin (ATTR) Valine30Methionine (Val30Met), who underwent a liver transplantation in Sweden in 1994, was treated with sildenafil citrate (Viagra) to ameliorate his erectile dysfunction (ED). Some clinical symptoms and the examination data for autonomic functions were improved after liver transplantation, but ED was never improved after the operation. Five years after liver transplantation, he requested a sildenafil citrate therapy to enhance his erectile potential. One and a half hours after the administration of 25 mg of sildenafil citrate, the skin surface temperature around the pelvic area increased and the penis became erect, though the postdose hemodynamic parameters did not significantly change from the respective baseline or predose values. He was able to have sexual intercourse, though ejaculation did not occur. This case report appears to suggest that sildenafil citrate is an effective drug to treat ED in patients with an organic impairment of the autonomic nervous system without altering systemic circulation.

Adult↗
PubMed2000

A new diagnostic procedure to detect unknown transthyretin (TTR) mutations in familial amyloidotic polyneuropathy (FAP).

Two patients with amyloidosis caused by transthyretin (TTR) were investigated by immunohistopathologic, mass spectrometric, and molecular genetic methods. After confirming the immunoreactivity of TTR in the amyloid deposits using anti-TTR polyclonal antibody, a new method: centrifugal concentration and electrospray ionization mass spectrometry (ESI-MS) was employed to detect the variant TTR in the serum. Only 50 microl of the serum and 30 microl of the anti-TTR antibody were needed for the analysis. After incubation with the antibody, the samples were passed through a 1000 kDa cut off centrifugal concentrator to retain the antibody, thereafter, the filtrate was analyzed by ESI-MS. Several forms of normal and variant TTR were detected in the serum samples: unconjugated TTR, cysteine and cysteine-glycine conjugated TTR. In the patients, a variant form of TTR was detected with a 26.0 Da higher molecular weight than that of normal TTR. Single-strand conformation polymorphism (SSCP) and direct sequence analysis confirmed the presence of a one-base substitution situated at the codon 50 from AGT (Ser) to ATT (Ile) in both patients, that corresponded to the increased molecular weight of 26.0. The present diagnostic procedure demonstrates the usefulness of both ESI-MS and SSCP to screen for TTR related amyloidosis rapidly. Moreover, the DNA samples obtained from the band showing abnormal electrophoretic migration pattern in SSCP, facilitate the direct sequence analysis to detect the unknown mutation, and the observed shift in molecular weight of the variant TTR in ESI-MS confirms the base substitution.

Amino Acid Substitution↗
PubMed2000

ASCA Observation of the Quiescent X-Ray Counterpart to SGR 1627-41.

We present a 2-10 keV ASCA observation of the field around the soft gamma repeater SGR 1627-41. A quiescent X-ray source, whose position is consistent both with that of a recently discovered BeppoSAX X-ray source and with the Interplanetary Network localization for this soft gamma repeater, was detected in this observation. In 2-10 keV X-rays, the spectrum of the X-ray source may be fit equally well by a power-law, blackbody, or bremsstrahlung function, with unabsorbed flux approximately 5x10-12 ergs cm-2 s-1. We do not confirm a continuation of a fading trend in the flux, and we find no evidence for periodicity, both of which were noted in the earlier BeppoSAX observations.

Journal Article↗
PubMed2000

Endothelium-dependent vasodilatation in patients with familial amyloidotic polyneuropathy.

We examined endothelium-dependent vasodilatation in 15 familial amyloidotic polyneuropathy (FAP) amyloidogenic transthyretin (ATTR) Valine30Methionine (Val30Met) patients and 12 healthy volunteers. Using ultrasonography, we measured the radial artery diameters under both baseline and hyperemic conditions. Endothelium-dependent vasodilatation was expressed as a percent increase in the diameters of the radial artery after induced hyperemia. Endothelium-dependent vasodilatation tended to decrease in the patients, compared with healthy volunteers. Responses were not elicited at all in patients with disease of more than 9 years' duration. Linear negative correlation was observed between endothelium-dependent vasodilatation and disease duration (P < 0.01). Correlation between endothelium-dependent vasodilatation and degree of autonomic dysfunction was significant (P = 0.0524) and for age was close to significance (P = 0.051). These results suggest that the peripheral vasomotor dysfunction in FAP patients may predominantly depend on the amount of amyloid deposition around the vessels through the course of illness.

Adult↗
PubMed2000

Bacterial superantigen staphylococcal enterotoxin B induces interstitial pneumonia in SCID mice reconstituted with peripheral blood mononuclear cells from collagen vascular disease patients.

To investigate whether superantigens induce interstitial pneumonia associated with collagen vascular disease (CVD), staphylococcal enterotoxin B (SEB) was intratracheally administered to SCID mice reconstituted with peripheral blood mononuclear cells (PBMCs) from CVD patients that suffered lung complications. Although a slight accumulation of inflammatory cells into the perivascular area was seen in the lungs of SCID mice injected with PBMCs from CVD patients or healthy donors, SEB administration significantly increased the severity of inflammation in the lungs of SCID mice that received CVD patient PBMCs. Furthermore, human leukocytes were detected by immunohistochemistry in the lungs of SCID mice that received SEB after reconstitution with PBMCs from CVD patients but not in other groups of SCID mice. CD45RO(+) memory T cells comprised the majority of infiltrating human leukocytes. These results suggest the possibility that external superantigens may induce the development of interstitial pneumonia in patients that have a genetic background predisposition to autoimmune disease.

Adoptive Transfer↗
PubMed2000

Resting 123I-BMIPP scintigraphy for detection of organic coronary stenosis and therapeutic outcome in patients with chest pain.

PURPOSE: Resting 123I-BMIPP scintigraphy can detect coronary artery disease based on persistent abnormality of myocardial fatty acid metabolism after transient ischemia. The present study aimed to determine the value of resting 123I-BMIPP scintigraphy in diagnosing coronary artery disease and predicting the therapeutic outcome in patients with chest pain symptom. METHOD: Five hospitals participated in this study, and scintigraphic and angiographic studies were performed in 104 patients without myocardial infarction. Twenty of them had non-coronary artery disease (chest pain syndrome), 26 had stable effort angina, 35 had unstable angina with organic coronary lesions, and 23 had vasospastic angina without significant organic stenosis. RESULTS: Overall sensitivity for diagnosing angina pectoris (stable, unstable and vasospastic) was 45%, and overall specificity for excluding non-coronary artery disease was 80%. The incidence of positive 123I-BMIPP was 54% among patients with organic coronary stenosis (50% in stable angina and 61% in unstable angina with organic stenosis), but it was low (22%) in vasospastic angina without organic stenosis. Patients with advanced coronary stenosis and multi-vessel disease were found to have a higher incidence of positive 123I-BMIPP. A positive 123I-BMIPP result was correlated with a higher rate of subsequent intervention therapy (catheter intervention or CABG) than a negative result (48% versus 27%, p = 0.03 at one month; and 63% versus 35%, p = 0.008 at one year). CONCLUSION: Resting 123I-BMIPP scintigraphy was valuable in detecting advanced coronary lesions in angina patients associated with a high incidence of subsequent intervention therapy.

Aged↗
PubMed2000

Autologous tissue-fragmented extracardiac conduit with rapid, stable endothelialization due to angiogenesis.

OBJECTIVES: Autologous angiogenic cytokines are known to activated by mincing stimulation, and well regulated in vivo. We applied this tissue fragmentation technique to a low-pressure pulmonary extracardiac conduit to obtain rapid endothelialization and stable neointima formation due to angiogenesis. METHODS: Subcutaneous adipose tissue was obtained, minced, suspended, and sieved through highly porous fabric vascular prosthesis by pressurized injection. The adipose tissue fragmented graft with an autologous fresh pericardial monocusp valve was implanted between the right ventricle and the pulmonary artery in 13 dogs. The same grafts without fragments were implanted in 8 dogs as controls. No anticoagulation therapy was given. RESULTS: Grafts were removed 6 to 1,128 days after implantation. In the developed grafts, angiogenesis occurred throughout the interstices of the graft wall from the adventitial side, and host cells proliferated and migrated. Endothelialization was completed throughout developed grafts at 2 weeks. The intima was still thin up to 1,128 days and free of degenerative changes. In control grafts, however, capillary infiltration was limited to perigraft tissue at 2 weeks and endothelialization was not completed by 3 months. Under the endothelial cell layer, laminal elastic fibers were formed through the developed graft wall by 4 months and still maintained at 1,128 days. CONCLUSIONS: The results demonstrated that adipose tissue fragmented extracardiac conduits induce rapid endothelialization and maintained thin intima with laminal elastic fibers. Long-term durability is expected based on results from using this technique in a low-pressure pulmonary system in dogs.

Adipose Tissue↗
PubMed2000

Surgical considerations of occlusive lesions associated with Takayasu's arteritis.

OBJECTIVE: Takayasu's arteritis is an inflammatory vascular disease of unknown etiology that affects the aorta and its main branches, requiring surgical intervention due to occlusive lesions. We studied early and late surgical results. METHODS: Between 1979 and December 1998, 46 patients--1 man and 45 women aged 15 to 72 years (mean: 46 +/- 13 years)--with occlusive lesions caused by Takayasu's arteritis underwent surgery. Preoperative steroids were administered to 22 patients having inflammation. Diagnosis indicating surgery included obstructive cervical vessel disease in 13 patients, obstructive coronary artery disease in 19, aortic coarctation in 15, and abdominal branch stenosis in 3. Surgical procedures involved bypass grafting in 31 (cervical vessel bypass in 13, ascending-abdominal aortic bypass in 4, axillary artery-abdominal aortic bypass in 10, descending-abdominal aortic bypass in 1, abdominal branch bypass in 3), coronary artery bypass grafting in 10, and coronary ostial endarterectomy in 9. RESULTS: Four (8.7%) died during hospitalization. Follow-up ranged from 1 to 240 months (mean: 117 months). Eight suffered late deaths and 6 patients died of cardiovascular problems. The total actuarial survival rate was 76.2% at 5 years and 70.5% at 10 years. CONCLUSIONS: Steroid therapy before and after surgery appears to affect the overall prognosis positively in patients with Takayasu's arteritis.

Adolescent↗
PubMed2000

Surgery in three-channeled aortic dissection. A 31-patient review.

OBJECTIVE: Three-channeled aortic dissection with 2 adjacent false lumens present is rare. METHODS: The 31 patients whose dissections we treated surgically accounted for 7.3% of the 426 patients with aortic dissection treated surgically between 1978 and May 1999. The 17 men and 14 women ranged in age from 24 to 77 years (mean: 45 +/- 12 years). Marfan syndrome was present in 18. Pain was observed at different times in 20. computed tomography scanning and magnetic resonance image proved useful in preoperative diagnosis. The morphology of the 1st and 2nd false lumens was Stanford type A + B in 13, type B + B in 15, type A + A in 2, and localized abdominal dissection in 1. RESULTS: Descending aortic replacement was done in 18 patients, thoracoabdominal aortic replacement in 7, ascending aortic replacement in 3, and others in 3. Five patients died in hospital and later during follow-up for 1-181 months (mean, 57 +/- 55 months). CONCLUSIONS: Pain recurring in patients with aortic dissection should alert the physician to the possibility of 3-channeled dissection and the necessity of surgery. The incidence of such dissection is high in patients with Marfan syndrome.

Adult↗