Biomedical subjects

H Abe

Publications and source records attributed to H Abe.

At least 631 records · Page 35Linked to original sources

PubMed1995

Plasma catecholamines and cyclic AMP response during head-up tilt test in patients with neurocardiogenic (vasodepressor) syncope.

To examine hemodynamic, plasma catecholamines, and cyclic AMP changes during tilt in patients with neurocardiogenic (vasodepressor) syncope, six patients underwent 80 degrees head-up tilt test for 10 minutes with isoproterenol infusion (1-3 micrograms/min). Venous blood was sampled in the supine position, at 3 minutes of tilt, and at the onset of vasodepressor reaction during tilt. All patients had previous tilt studies in which vasodepressor syncope had been induced reproducibly (mean 3.3 episodes in each patient). Syncope was induced at 6.1 +/- 0.4 minutes of tilt with an infusion of isoproterenol (mean 1.7 +/- 0.3 micrograms/min). Although arterial pressure and heart rate did not change significantly between in the supine position and at 3 minutes of tilt, plasma norepinephrine increased significantly at 3 minutes of tilt (0.44 +/- 0.10 ng/mL; P < 0.05) and at the onset of vasodepressor reaction (0.49 +/- 0.12 ng/mL; P < 0.01) compared to the supine position with isoproterenol (0.34 +/- 0.10 ng/mL). Also, cyclic AMP (cAMP) increased significantly at 3 minutes of tilt (25.3 +/- 2.0 pmol/mL; P < 0.005) and at the onset of vasodepressor reaction (29.6 +/- 1.7 pmol/mL; P < 0.005) compared to the supine position with isoproterenol (20.4 +/- 1.9 pmol/mL). After administration of selective beta 1-blocker, metoprolol (40 mg/day), plasma norepinephrine, and cAMP during tilt did not change significantly compared to baseline tilt. However, metoprolol prevented the syncope in 3 of 6 patients. After administration of beta 1-, beta 2-blocker, propranolol (30 mg/day), cAMP at 3 minutes of tilt decreased significantly compared to the baseline tilt (16.9 +/- 1.4 pmol/mL vs 25.3 +/- 2.0 pmol/mL; P < 0.05) and propranolol prevented the syncope in all six patients. We concluded that the increase of cAMP may play an important role for the induction of vasodepressor reaction in patients with neurocardiogenic (vasodepressor) syncope. The concentration of cAMP showed more sensitive response to vasodepressor reaction than that of norepinephrine.

Adrenergic beta-Agonists↗

PubMed1995

A histopathological study of alcoholics with chronic HCV infection: comparison with chronic hepatitis C and alcoholic liver disease.

To clarify the relationship between hepatitis C virus infection and excessive alcohol intake, we carried out histological examination of the liver in 46 alcoholics with chronic hepatitis C virus infection and compared the findings in 55 patients with chronic hepatitis C, 38 with alcoholic liver disease, and 27 with chronic hepatitis B. The majority of alcoholics with chronic hepatitis C virus infection displayed virus-related histological changes very similar to those in chronic hepatitis C, including frequent lymphoid follicles (34.7%) or aggregates (93.3%) in the portal tracts, mild necroinflammatory change (76.1%) in the parenchyma, and lymphocytosis in sinusoids (83.7%). Liver cell dysplasia and irregular regenerative activity of hepatocytes were rarely observed. The effects of alcohol on the liver were found to be minimal in the majority. These findings could suggest that the hepatic injury in the majority of alcoholics with chronic hepatitis C virus infection in Japan is due to persistent hepatitis C virus infection rather than to alcoholic injury. In addition, our study disclosed that the perivenular fibrosis which is designated as a histological characteristic of alcoholic liver disease is frequently observed in chronic hepatitis C. These similarities suggest that a similar fibrogenesis is present in chronic hepatitis C and alcoholic liver disease.

Adult↗

PubMed1995

Analysis of viral DNA, protein and envelope damage after methylene blue, phthalocyanine derivative or merocyanine 540 photosensitization.

Although numerous photosensitizers have been used experimentally to decontaminate viruses in cellular blood components, little is known about their mechanisms of photoinactivation. Using M13 bacteriophage and vesicular stomatitis virus (VSV) as model viruses, we have investigated alteration of the viral genome, protein and envelope after phototreatment. Methylene blue (MB) and aluminum phthalocyanine tetrasulfonate (AlPcS4) phototreatment inactivated bacteriophage M13 and decreased the fraction of single-stranded circular genomic DNA (sc-DNA) by converting it to linear form. This conversion was enhanced by treating the extracted DNA with piperidine at 55 degrees C. Piperidine-labile breaks were well correlated to phage survival (5.1% sc-DNA at 1.7% phage survival for MB) under conditions where only minor differences were seen in the relative abundance of M13 coat protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Neither aluminum phthalocyanine (AlPc) nor merocyanine 540 (MC540) inactivated M13 nor were there significant changes observed in DNA and coat protein. Methylene blue, AlPcS4 and AlPc inactivated VSV and inhibited fusion of the virus envelope to Vero cells at pH 5.7 (i.e. with plasma membrane). However, the degree of this inhibition was small compared to the extent of virus inactivation (43% inhibition vs. 4.7 log10 or 99.998% inactivation, for MB). In contrast, an antibody to VSV G-spike protein inhibited fusion at pH 5.7 by 52% with a concomitant decline in VSV infectivity of 0.15 log10 (30%). Few changes were observed in the relative abundance of G protein for MB and AlPcS4 phototreated samples and no additional protein bands were observed on SDS-PAGE.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Cerebral haemodynamics and long-term prognosis after extracranial-intracranial bypass surgery.

The effectiveness of extracranial-intracranial arterial (EC-IC) bypass surgery for haemodynamic stroke remains controversial. In this study correlation of presurgical and postsurgical cerebral haemodynamics with long term prognosis was evaluated. Twenty eight patients (25 men, three women: mean age 61.4 (SD 8.2) years) with reduced cerebrovascular reserve due to steno-occlusive cerebral vascular disease formed the study group. Measurement of mean hemispheric cerebral blood flow (mCBF) and the cerebral vasodilatory capacity (% mCVR) with an intravenous acetazolamide injection were performed by a xenon-133 inhalation method and SPECT. Patients were treated with EC-IC bypass surgery and measurements of mCBF and % mCVR were made again about one month after surgery. The patients were then observed for a long period (range 27-115 months). During the observation period, four patients experienced subsequent ischaemic strokes. The presurgical and the postsurgical resting mCBF for the affected hemisphere were significantly reduced in the patients with strokes during follow up compared with the values in patients without strokes during follow up (P < 0.03 and 0.01 respectively). The % mCVR of the affected hemisphere was significantly raised after surgery in all patients except one (P < 0.01). The postsurgical change in resting mCBF was not unidirectional. In conclusion, resting mCBF was unchanged and % mCVR was improved after EC-IC bypass surgery in patients with reduced cerebrovascular reserve. The group of patients with a reduced presurgical and postsurgical resting mCBF continue to be a high risk group for subsequent ischaemic stroke seen after EC-IC bypass surgery.

Aged↗

PubMed1995

Localization of platelet-derived growth factor and insulin-like growth factor I in the fibrotic lung.

To better understand the mechanisms responsible for the increase in numbers of fibroblasts and increased collagen synthesis in fibrotic intestitial lung diseases, platelet-derived growth factor (PDGF)-A and PDGF-B, PDGF receptor-alpha and -beta, insulin-like growth factor I (IGF-I), and IGF-I receptor were evaluated immunohistochemically. Additionally, the messenger ribonucleic acids (mRNAs) for PDGF-A and PDGF-B, PDGF receptor-alpha and -beta, and IGF-I were investigated by in situ hybridization in alveolar macrophages and lung tissues from patients with interstitial lung disease. In specimens of bronchoalveolar lavage fluid (BALF), PDGF-A, PDGF-B, and IGF-I were local in alveolar macrophages in patients with idiopathic pulmonary fibrosis (IPF), patients with sarcoidosis (Sar), and normal individuals. Although there were no differences between IPF and Sar in terms of the staining intensity or number of positive cells, the number of such cells was smaller in the normal controls. In lung tissues with early-stage IPF, PDGF and IGF-I proteins were localized exclusively in alveolar macrophages, mononuclear phagocytes, fibroblasts, alveolar Type II cells, vascular endothelial cells, and vascular smooth-muscle cells. In lung tissues with late-stage IPF and those from normal controls, only alveolar macrophages contained PDGF and IGF-I proteins. Interestingly, the cellular localizations of PDGF receptor-alpha and -beta, and of IGF-I receptor were the same as those of the PDGF and IGF-I proteins in early-stage IPF, whereas these cells were not positive for any of these substances in late-stage IPF or normal controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Transesophageal echocardiography combined with magnetic resonance imaging for detecting venous anomalies in dextrocardia. A case report.

A fifty-six-year-old woman was admitted to Osaka Rosai hospital because of dyspnea, chills, and fatigue. The patient was diagnosed by transthoracic echocardiography as having congestive heart failure due to severe biatrioventricular valve regurgitation, and cardiac surgery was proposed. Preoperative transesophageal echocardiography (TEE) revealed a dilatation of the coronary sinus (CS), a right-sided hemiazygos vein (R-AZ), and another great vessel lying between the CS and the R-AZ. Magnetic resonance imaging (MRI) was also performed, and this showed a persistent right superior vena cava (PRSVC) entering the left atrium via the dilatated CS. However, the site of connection between the R-AZ and the PRSVC could not be detected by MRI because of inadequate slice acquisition. Each method has its limitations, particularly with regard to visualizing the extracardiac vascular system. Therefore, the authors demonstrated that the combination of TEE and MRI might be more useful than each alone, and the combination is as a valuable method as digital subtraction angiography for the diagnosis of extracardiac venous anomalies.

Angiography, Digital Subtraction↗

PubMed1995

Two distinct retinal projections to the hamster suprachiasmatic nucleus.

Electrical stimulation of the intergeniculate leaflet (IGL) region in hamsters can induce expression of Fos-like immunoreactivity (lir) in a restricted portion of the dorsolateral suprachiasmatic nucleus (SCN). The authors investigated whether the mechanisms by which stimulation affects SCN cells involves orthodromic activation of IGL cells projecting to the SCN or antidromic activation of retinal ganglion cells that send bifurcating axonal projections to both the IGL and the SCN. Bilateral optic enucleation strongly reduced induction of Fos-lir in SCN cells in response to electrical stimulation of the IGL region, implicating antidromic activation of retinal ganglion cells as the mechanism. This result implies that a class of retinal ganglion cells that project to the IGL also project selectively to the dorsolateral SCN. Earlier pharmacological studies suggest that this anatomically distinct retinal projection to the SCN is also neurochemically different from that innervating the rest of the nucleus.

Animals↗

PubMed1995

Regional distribution of growth hormone-releasing hormone (GHRH) receptor mRNA in the rat brain.

We examined the tissue distribution of growth hormone-releasing hormone (GHRH) receptor mRNA in the rat brain because several lines of evidence have suggested that GHRH plays a functional role in the brain. GHRH receptor mRNA was detected in the hypothalamus as well as pituitary, but not in olfactory bulb, caudate putamen, cerebral cortex, hippocampus, cerebellum, or brainstem by RNase protection assay. To clarify the precise localization of GHRH receptor mRNA in the hypothalamus, reverse transcription-polymerase chain reaction (RT-PCR) was used. A PCR product of the predicted size (564 bp) was detected in the periventricular, arcuate, and ventromedial nuclei, and the anterior hypothalamic area, but not in the paraventricular nucleus in the hypothalamus. These areas where GHRH receptor mRNA was detected are possible sites of GHRH action. Another band, smaller in size than that of the predicted PCR amplification product, was detected in the anterior hypothalamic area and arcuate nucleus, respectively. Hybridization analysis with a cDNA probe for GHRH receptor demonstrated that the smaller bands as well as that of the predicted size corresponded to GHRH receptor cDNA. The role of the short form of the GHRH receptor remains unknown.

Animals↗

PubMed1995

Ruptured dissecting vertebral artery aneurysm detected by repeated angiography: case report.

A case of a ruptured dissecting aneurysm of the vertebral artery, which was detected by repeated angiography (third time), is reported. A 59-year-old woman, whose preoperative angiogram showed no abnormality, underwent a bifrontal craniotomy and the total removal of the right frontal glioma. However, a subarachnoid hemorrhage was detected by computed tomography the day after the surgery. Conventional angiography performed on the same day revealed no definite abnormality. Nevertheless, 9 days after surgery, a second subarachnoid hemorrhage occurred. The dissecting aneurysm of the vertebral artery was revealed by angiography. It is important to suspect this type of aneurysm as a differential diagnosis when the cause of the subarachnoid hemorrhage is not clarified in the first angiogram.

Aortic Dissection↗

PubMed1995

Magnetic resonance images reveal a high incidence of asymptomatic pineal cysts in young women.

MACROSCOPIC BENIGN PINEAL cysts, according to previous reports, may preferentially occur in the young population at the fourth decade; symptomatic pineal cysts have been found mainly in females. To confirm the relationship of age and sex to the incidence of pineal cysts, we reviewed 8623 consecutive magnetic resonance images in 6023 patients. Tiny and obscure cysts in the pineal gland were ignored; only the pineal cysts > 5 mm were examined. The cysts were encountered in 79 (1.3%) of 6023 patients evaluated. The cysts predominantly occurred in females; we found 29 cysts in 3008 males and 50 cysts in 3015 females (P < 0.05). Young adults had higher incidence of these cysts, with a peak incidence occurring between the ages of 21 and 30 years, then the incidence gradually decreased with age. We found no significant age distribution in males. However, among all groups, young women between the ages of 21 and 30 years had the highest frequency (5.82%). The incidence of pineal cysts among women between the ages of 21 and 30 years was significantly higher than in any other group (P < 0.001; 21-30 versus 51-60, 61-70, and 71-80). In females, when the incidence below the age of 41 was compared with that above or equal to 41, the z score was 4.98 (P < 0.001). The cystic expansion of the pineal gland in females appeared to begin at adolescence, and presumably the pineal gland decreases in size with aging. In this article, we will also speculate about the relationship of these changes to the secretory activity of the pineal glands.

Adolescent↗

PubMed1995

Surgical indication and results of foramen magnum decompression versus syringosubarachnoid shunting for syringomyelia associated with Chiari I malformation.

Several surgical procedures have been used for the treatment of syringomyelia associated with Chiari I malformation at our institute. The purpose of this article is to evaluate the results of two major surgical procedures, foramen magnum decompression (FMD) and syringosubarachnoid (SS) shunting. The series consisted of 70 patients with syringomyelia associated with Chiari I malformation who were surgically treated. Their ages ranged from 3 to 59 years (median, 29.4 yr). FMD was performed on 33 patients, and SS shunting was performed on 37 patients. The follow-up period ranged from 6 months to 12.5 years, with a mean of 60 months. The clinical and radiological outcomes were analyzed comparing the two groups. We principally performed FMD in patients with symptoms of Chiari I malformation and/or a small syrinx. We prefer to use SS shunting in patients with large syringes. Postoperative magnetic resonance imaging demonstrated that the syrinx had collapsed or decreased in size in 94% of the patients who underwent FMD and in 100% of the patients who underwent SS shunting. Neurological improvements were observed in 82% and in 97% of the patients who underwent FMD and SS shunting, respectively. In particular, the relief of pain was more fully achieved after SS shunting than after FMD. The average time for the syrinx to collapse was 6.3 weeks after surgery in the FMD group and 1.8 weeks in the SS shunting group. These results indicate that clinical symptoms and radiological findings improved much more quickly in the SS shunting group than in the FMD group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1995

Blood pressure monitoring in feeding arteries of cerebral arteriovenous malformations during embolization: a preventive role in hemodynamic complications.

To study the hemodynamics of arteriovenous malformations and to avoid hemodynamic complications during and after artificial embolization, we measured arterial blood pressures in 21 feeders in 14 patients through a microcatheter system. Before embolization, the pressures were significantly low in feeders with branches terminating in the malformation (terminal divided branches) and comparatively low in arteriovenous malformations with rapid blood flow through the malformation. The pressures in feeders with brain-nutrifying branches distal to the nidus (transient branches) were significantly high. Therefore, transient branches might be distinguishable from terminal divided branches with the use of feeder pressure monitoring. A hemorrhagic complication occurred in one patient. The feeder pressure in this patient was low before embolization and showed the maximum change among the patients after embolization. It seems that the lower the feeder pressure, the more likely complications are to occur, owing to remarkable hemodynamic alterations. Feeder pressure monitoring may be useful for preventing hemodynamic complications, especially when angiographic findings show feeding arteries giving off terminal divided or transient branches or rapid blood flow through the malformation.

Adolescent↗

PubMed1995

Effects of cofilin on actin filamentous structures in cultured muscle cells. Intracellular regulation of cofilin action.

The previous investigation (Abe et al. (1989) J. Biochem. 106, 696-702) suggested that cofilin is deeply involved in the regulation of actin assembly in developing skeletal muscle. In this study, to examine further the function of cofilin in living myogenic cells in culture, recombinant cofilin having extra Cys residues at the N terminus was produced in Escherichia coli and was labeled with tetramethylrhodamine-iodoacetamide (IATMR). When the cofilin labeled with IATMR (IATMR-cofilin) was introduced into myogenic cells, actin filaments in the cytoplasm or nascent myofibrils were promptly disrupted, and many cytoplasmic rods which contained both IATMR-cofilin and actin were generated. Sarcomeric myofibrillar structures were not disrupted but tropomyosin was dissociated from the structures by the exogenous cofilin, and the IATMR-cofilin became localized in I-band regions. 24 hours after the injection, however, the actin-cofilin rods disappeared completely and the IATMR-cofilin became diffused in the cytoplasm as endogenous cofilin. Concomitantly, actin filaments were recovered and tropomyosin was re-associated with sarcomeric I-bands. At this point, the IATMR-cofilin in the cells still retained the functional activity to form intranuclear actin-cofilin rods in response to stimulation by DMSO just as endogenous cofilin. FITC-labeled actin introduced into myogenic cells at first failed to assemble into filamentous structures in the presence of the exogenous cofilin, but was gradually incorporated into myofibrils with time. The drastic effects of the exogenous cofilin on actin assembly were suppressed by phosphatidylinositol 4,5-bisphosphate (PIP2). These results indicate that the exogenous cofilin is active and alters actin dynamics remarkably in muscle cells, but its activity in the cytoplasm gradually becomes regulated by the action of some factors including PIP2-binding.

Actin Depolymerizing Factors↗

PubMed1995

Relationship between apparent total body clearance of cyclosporin A and its erythrocyte-to-plasma distribution ratio in renal transplant patients.

To establish an optimal method for determining a cyclosporin A (CyA) regimen based on physiological changes that occur during immunosuppressive therapy, the relationship between apparent CyA body clearance (CL/f) and the CyA erythrocyte-to-plasma distribution ratio (CyA-EP) was examined using clinical time courses obtained during routine monitoring. The CyA-EP, which was calculated by a multiple regression formula using routine data, was increased during renal dysfunction involving the normal recovery phase after transplantation, during nephrotoxicity, during acute tubular necrosis, and during acute renal rejection. CyA total body clearance (CLt), calculated by multiplying CL/f and converted bioavailability, fc (which is equal to 0.009 x LD, where LD represents the CyA level in blood per dose ratio), showed hyperbolic decay with increasing CyA-EP (the mean CLt was defined as follows: CLt = 0.937/CyA-EP), whereas fc showed exponential decay with increasing CyA-EP (the mean fc was defined as follows: fc = 0.593 x exp(-0.155 x CyA-EP)). These findings suggest that total CyA body clearance and its bioavailability were suppressed during the renal dysfunction phase. Hence, the mean CL/f as a function of the CyA-EP was given by the following equation: CL/f = 1.390 x exp(0.204 x CyA-EP)/CyA-EP. Since the CyA-EP reflects a patient's disease state and alterations in the CyA pharmacokinetic profile, these model formulae should provide an adequate method for determining a CyA dosage regimen for several disease states after renal transplantation.

Adult↗

PubMed1995

Detection of Hepatozoon canis oocyst from ticks collected from the infected dogs.

We collected 220 ticks from 58 dogs infected with Hepatozoon canis from 1990 to 1992 in Yamaguchi and Fukuoka prefectures, the western provinces of Japan. These ticks were identified as Haemaphysalis campanulata, H. longicornis, H. flava, Ixodes ovata, and I. nipponensis. By histopathological examination of these ticks, two oocysts which seemed to be those of H. canis were observed in the haemocoele of an adult female H. longicornis and a nymph H. flava tick. The oocyst, about 300 x 150 microns in size, was composed of 50 to 70 sporocysts with 10 to 16 banana-shaped sporozoites each.

Animals↗

PubMed1995

Sustained-release procainamide-induced reversible granulocytopenia after myocardial infarction.

A 71-year-old man with paroxysmal atrial fibrillation who had a previous anterior myocardial infarction exhibited granulocytopenia 8 days following the administration of oral sustained-release procainamide (750 mg/day). The plasma concentrations of procainamide and N-acetyl procainamide were at subtherapeutic levels. Discontinuation of procainamide led to complete recovery. A bone marrow aspiration showed slight hypoplasia with normocellular marrow. Lupus erythematosus (LE) and antinuclear antibody (ANA) tests were negative. The frequency and relationship of granulocytopenia caused by sustained-release procainamide in patients with tachyarrhythmias are briefly discussed, and prior reported cases are reviewed. Precautionary measures for the early recognition of this grave hazard in exposed patients are advocated. The physician should be aware of this complication before in initiating treatment with this drug.

Aged↗

PubMed1995

Serial changes in metabolism and histology in the cold-injury trauma rat brain model--proton magnetic resonance imaging and spectroscopy study.

The serial changes in metabolism and histology during the first 24 hours in the cold-injury trauma rat brain model were investigated by proton magnetic resonance (MR) imaging and high-resolution proton MR spectroscopy. Edema developed extensively via the corpus callosum in the ipsi- and contralateral hemispheres during observation as shown by gradually increased signal intensity on proton MR images. Proton MR spectroscopy showed increased levels of acetate (Ace), lactate (Lac), and glutamine (Glmi) 1 hour after lesion formation. The elevated Glmi level slightly decreased, the level of alanine (Ala) increased substantially, and that of N-acetyl-aspartate (NAA) decreased markedly after 24 hours. Increased Lac, Ace, and Ala might reflect anaerobic glycolysis associated with mitochondrial dysfunction, while decreased Glmi and NAA reveal brain tissue breakdown. The relationship between brain edema and tissue viability can be analyzed in detail using this simple traumatic model and MR techniques which will be useful in the development of therapeutic agents for brain injury.

Acetates↗

PubMed1995

Intraoperative spinal sonography in the cervical anterior approach.

Intraoperative spinal sonography was used during cervical anterior approach procedures for cervical discectomy and osteophytectomy to demonstrate spinal pulsation, the protruded disc or osteophyte, the anterior subarachnoid space, and the spinal cord. Spinal pulsation was recognized in some cases before removal of the disc but the anterior subarachnoid space and spinal cord could not be observed. However, the latter were more clearly observed during removal of the disc and could be seen after total removal of the disc and osteophyte. This method allows confirmation of decompression and pulsation of the spinal cord without cutting and removal of the posterior longitudinal ligament.

Adult↗