[Visualization of the coronary arteries with helical scan in fast CT].
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Aged↗
Biomedical subjects
S Koga
Publications and source records attributed to S Koga.
Effect of bevantolol and propranolol on serum lipids in patients with essential hypertension.
In patients with essential hypertension, the beta-blockers bevantolol or propranolol were administered once or twice a day for twelve weeks to evaluate the effects on blood pressure, and lipid metabolism. Both systolic and diastolic blood pressure decreased significantly in response to both bevantolol and propranolol. The pulse-rate also decreased significantly in both groups. Total cholesterol did not change significantly in both groups. Triglycerides increased significantly in the bevantolol group. HDL cholesterol decreased significantly in the propranolol group. The LDL cholesterol/HDL cholesterol ratio increased significantly in the propranolol group, while no significant increase was observed in the bevantolol group. The apolipoprotein B/A ratio was elevated in the propranolol group. No serious side-effects were noted during the study in both groups. These results indicate that bevantolol is an effective antihypertensive drug with fewer unfavorable effects on lipid metabolism than propranolol.
Adrenergic beta-Antagonists↗
[In vivo characteristics of IBZM in rat brains: an agent for quantitative SPECT imaging of D2 dopamine receptors--a basis for semiquantitative measurement of the receptor density using equilibrium analysis].
To establish a basis for semiquantitative SPECT measurements of the D2 dopamine receptor density using equilibrium analysis, we evaluated in vivo kinetic properties of 125I-IBZM in rat brains. We measured percent uptakes (% dose/g) of 125I-IBZM in the striatum, frontal cortex, and cerebellum. We made these regional measurements at 15, 30, 45, 60, 90, and 120 minutes after injection, respectively. The specific striatal uptake, which is the uptake difference between striatum and frontal cortex or cerebellum, showed a transient equilibrium phase at 60 min. Theoretically, with these 'reversible' D2 receptor binding ligands, the tracer-uptake ratio of the striatum-to-frontal cortex or cerebellum during the equilibrium phase provides an estimate of binding potential (Bound/Free = Bmax/Kd). Our experiment showed that these ratio increased with time after bolus injection of the tracer. Striatum to frontal cortex or cerebellum ratios which were calculated with pooled data (n = 12) at 60 minutes in equilibrium phase showed nearly constant values (C.V. = 12.3% and 13.5%, respectively). Although measuring the striatum to frontal cortex or cerebellum ratios near equilibrium phase by bolus injection of the tracer which are widely used in human SPECT study could not exactly signify the binding potential, those ratios at fixed time after injection would be reliable for semiquantitative index.
Animals↗
A point mutation in the bile acid biosynthetic enzyme sterol 27-hydroxylase in a family with cerebrotendinous xanthomatosis.
Cerebrotendinous xanthomatosis (CTX) is a rare familial disorder characterized by progressive neurological dysfunction, atherosclerosis, and xanthomas with sterol storage in the nervous system, vessels, and tendons. Increased serum cholestanol, derived from intermediates of cholesterol catabolism, may possibly be a major cause of the disease. An examination was made of the cDNA encoding cytochrome P450 sterol 27-hydroxylase (CYP27) in hepatic mitochondria, considered a defective enzyme inducing CTX, in a Japanese housewife afflicted with CTX and her family. The proposita and one of her brothers, who also had CTX symptoms and hypercholestanolemia, were found to be homozygotic, carrying a point mutation in the CYP27 gene at Arg104 (CGG) to Trp104 (TGG). The mutant position has a 100% conserved positive charge in all known vertebrate cytochrome P450s and even in bacterial cytochrome P450cam. The mother of the proposita and another brother were both free of CTX symptoms and were heterozygotic for the mutation, although their plasma cholesterol increased moderately. An increase in plasma cholestanol alone would, thus, not appear to be a direct cause of sterol storage in CTX, while CTX is strongly suggested to be caused by defects in both alleles of the CYP27 gene.
Aged↗
[In vivo characteristics of IBZM in rat brains: an agent for quantitative SPECT imaging of dopamine D2 receptors. Preparation of 125I-IBZM and its biodistribution and kinetic properties].
123I-(S)-(-)-3-iodo-2-hydroxy-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl) methyl]-benzamide (IBZM) is a CNS dopamine D2 receptor imaging agent for SPECT and has already been used clinically in the United States, Canada and Europe. However, methods of quantitative SPECT measurement of the D2 receptor density have not been well established. We performed in vivo biodistribution studies of 125I-IBZM in rat brains as the first step toward establishment of a basis for quantitative SPECT imaging of D2 receptors in humans. 125I-IBZM was prepared by the chloramine-T method. Radiochemical yields were 80 to 90% and radiochemical purity was 94.7% on day 81 after labeling. At 10, 30, 60 and 120 min after injection of the radiopharmaceutical, the percent uptakes (% dose/g) in the rat striatum were 2.9, 1.9, 1.7 and 1.0, respectively. These kinetic data were considered suitable for SPECT imagings. Pretreatment with haloperidol (1 mg/kg) blocked specific striatal uptake and there was a significant reduction in the uptake to 40.9% of the unblocked uptake at 60 min after injection (p = 0.006). The regional IBZM uptake ratio of striatum-to-cerebellum increased steadily from 1.7 at 10 min to 5.7 at 120 min. This suggests that SPECT imaging must be done during fixed time after tracer injection for the semiquantitative ratio to be meaningful.
Animals↗
[A case of anaphylactic shock following the administration of Gd-DTPA].
We experienced a case of serious adverse reaction following the administration of Gd-DTPA (gadolinium with diethylenetriamine pentaacetic acid). The patient showed sneezing and hoarseness when Gd-DTPA was administered for the first time. At the second injection, when hydrocortisone was used in advance to prevent allergic reaction, she lapsed into a pre-shock state and anaphylactic reaction was strongly suggested by the laboratory data. The possibility that Gd-DTPA may cause the severe side effects must be noted.
Adult↗
[An application of dynamic CT for diagnosis of abnormal external ocular muscle movement].
To evaluate the movements of retrobulbar structures radiologically, we have developed a new technique called "external ocular muscle movement CT" (EOM CT), in which dynamic CT scanning is performed while the patient performs controlled eye movements. This new technique was applied in one volunteer and 72 patients with external ophthalmoplegia due to orbital mass lesion, hyperthyroid ophthalmopathy, blowout fracture, and other retrobulbar lesions. EOM CT permits the assessment of extraocular muscle contraction in cases of blowout fracture, the evaluation of muscular contraction in hypertrophy of the extraocular muscles, and the diagnosis of adhesions between the extraocular muscles and intraorbital masses. Radiation dose to the lens from EOM CT was measured using a phantom and TLD, and was compared with that of conventional CT scanning with a 5 mm slice thickness. The dose to the lens from EOM CT was three times higher than that for conventional CT in axial scanning, but in the coronal section of the retrobulbar region, the dose to the lens from EOM CT decreases to one twelfth that of conventional CT. EOM CT promises to be a powerful modality for functional evaluation of the extraocular muscles and other retrobulbar structures.
Adolescent↗
[Visualization of coronary arteries with helical scanning CT: diastolic reconstruction].
The purpose of this study was the visualization of coronary arteries by the diastolic reconstruction method with helical scanning (HES) CT. We chose diastolic phase images from the image data acquired with the HES technique using a continuous nutate-rotate fast CT scanner, because few motion artifacts are induced by cardiac pulsation during the slow filling diastolic phase. We assessed coronary diseases using this method based on HES-CT, and evaluated its clinical effectiveness. We also studied the clinical value of multiplanar reconstruction and three-dimensional surface reconstruction. The subjects consisted of 31 patients with coronary disease, aged 41-77 years. When a diastolic reconstruction HES-CT was employed, the average rate of visualization of the coronary arteries was 72%. An examination can be completed during a 30-second single breath-hold, permitting the acquisition of coronary artery images with excellent continuity. Calcified coronary arteries can be identified.
Adult↗
[Clinical usefulness of helical scanning CT (HES-CT) for orbital lesion].
Helical scanning CT (HES-CT) was applied to multiplanar reconstruction (MPR) and 3-D imaging for the diagnosis of 65 patients with orbital lesions. We employed the the Toshiba TCT-900S, a fourth-generation high-speed CT scanner equipped with a slip-ring system. In HES-CT, scanning was performed with continuous rotation of the X-ray tube for 30 s, while the couch top was simultaneously moved at a constant speed of 1 to 2 mm/s. Images were reconstructed from continuous raw data to obtain a slice pitch of 1 mm in the longitudinal direction. HES-CT was found to have some advantages over conventional thin slice CT: 1) a wide area could be scanned in a short time (30 s) without motion artifact, 2) small lesions could be easily detected because slice images could be generated with a fine pitch at arbitrary positions from continuous raw data, 3) MPR images had good continuity in the longitudinal direction, and 4) high contrast of structures was obtained in the orbital region. HES-CT was considered to be useful for the detection of orbital lesions.
Child↗
Acute hemorrhagic cystitis caused by adenovirus following renal transplantation: review of the literature.
We report on 4 male patients with acute hemorrhagic cystitis caused by adenovirus following renal transplantation. These patients showed symptoms of gross hematuria, urinary frequency, burning urination and fever. Adenovirus was isolated in all patients and 3 were positive for serotype 11. Complement-fixing antibody was positive for adenovirus in all cases. Acute hemorrhagic cystitis caused by adenovirus was self-limiting and reduction of immunosuppression was not required for its resolution. Clinical presentation of these patients is described and the literature is reviewed.
Acute Disease↗
Sonography in fracture of the penis.
Sonography was performed in 7 patients with fracture of the penis and in 6 cases it demonstrated the exact site of a tear in the tunica albuginea. It was useful in the diagnosis and management of these patients.
Adolescent↗
Sonography of urethral calculi.
We performed sonography in 7 males with membranous and posterior urethral calculi. Sonography demonstrated the urethral calculi in all 7 patients. These findings suggest that sonography is useful as a noninvasive screening technique for urethral calculi.
Adult↗
Novel preservation solution permits 24-hour preservation in rat and baboon cardiac transplant models.
BACKGROUND: Cardiac preservation for transplantation disrupts normal vascular homeostatic mechanisms. Hypoxia and reoxygenation increase endothelial cell permeability, induce procoagulant activity, and alter endothelial cell/leukocyte interactions, with a parallel reduction in endothelial cAMP and nitric oxide levels. Because hypoxia/reoxygenation simulates a significant component of the global ischemia/reperfusion of cardiac transplantation, we hypothesized that preservation failure may be related to these perturbations. This work focuses on repleting the intercellular/intracellular second messengers nitric oxide/cGMP and cAMP in the donor heart to enhance cardiac preservation for transplantation. METHODS AND RESULTS: A heterotopic rat heart transplant model was used to compare lactated Ringer's (LR) and University of Wisconsin (UW) solutions to a novel storage solution (Columbia University solution, CU), which contains a cAMP analogue (dibutyryl cAMP) and nitroglycerin (to enhance nitric oxide-related mechanisms). By 24 to 28 hours of preservation, no LR hearts survived (n = 9), 35% of UW hearts survived (n = 20), and 88% of CU-preserved hearts survived (n = 8; P < .05) versus LR or UW). The viability of preserved hearts was explored by determining whether CU preservation enabled myocytes to maintain resting membrane potentials and preserve their ability to generate an action potential in response to a field stimulus. Of 24 sites explored with a microelectrode in UW-preserved hearts, only 4% were able to generate an action potential, compared with 75% of 36 sites in CU-preserved hearts (P < .001), with corresponding preservation of resting membrane potential in the CU-preserved hearts (-13 mV for UW versus -54 mV for CU, P < .001). Orthotopic baboon cardiac transplantation performed after 24-hour simple hypothermic preservation demonstrated that no UW-preserved heart (n = 4) survived the perioperative period; in contrast, four of five hearts stored for 24 hours in CU solution sustained the recipient with minimal inotropic support, and two animals survived long-term. CONCLUSIONS: Sustaining higher levels of intercellular/intracellular second messengers cAMP and nitric oxide/cGMP provides a new approach to enhancing cardiac preservation.
Adenosine↗
Hypotensive effects and influence on serum lipids of SQ29,852, a new angiotensin converting enzyme inhibitor, in patients with essential hypertension: a comparison with atenolol.
The effects of SQ29,852 (n = 24), a new angiotensin converting enzyme inhibitor, and atenolol (n = 22), monotherapies were compared in 46 patients with mild to moderate essential hypertension. Both SQ29,852 (mean dose 15.0 +/- 5.1 mg/day) and atenolol (mean dose 37.5 +/- 18.5 mg/day) significantly decreased both systolic and diastolic blood pressures. There were no significant changes in serum lipids, apolipoproteins, lipoproteins or atherosclerotic indices after both SQ29,852 and atenolol. There were also no significant inter-group differences. There were no serious side effects or abnormal laboratory tests in both treatment groups. It is concluded that SQ29,852 is an effective antihypertensive drug without adverse effect on lipid metabolism.
Adult↗
[The administered activity of radionuclides in nuclear medicine--rational reduction of medical radiation exposure].
A survey of 104 hospitals was conducted to determine the administered activity of radionuclides. Eighty-five hospitals responded, and reported a total of 119,614 examinations in one year. The examinations included: bone scintigraphy, 26.4%; Thallium-201 (201Tl) myocardial scintigraphy, 15.5%; Gallium-67 (67Ga) scintigraphy, 13.3%; N-isopropyl-p-[123I]iodoamphetamine (IMP) brain perfusion scintigraphy, 7.0%. The administered activity was corrected by body weight only for children at more than 80% of the responding hospitals. The number of hospitals that reported over-administration of radionuclide varied according to the type of scintigraphy performed: bone, 76%; inflammatory (67Ga), 93%; myocardial (201Tl), 89.2%; brain (IMP), 8.5%. The administered activity of IMP was closer to the upper limits specified in the Recommendations on Standardization of Radionuclide Imaging by the Japan Radioisotope Association (1987), because IMP is very expensive and is supplied as single vials. The highest average effective dose was for myocardial scintigraphy, the second-highest for inflammatory scintigraphy, and the third-highest for bone scintigraphy. In 201Tl and 67Ga scintigraphy, the entire contents of the vial may be administered two days before the expiration date, because the ratio of (true patient administered activity) to (declared patient administered activity) is similar to the ratio of (radioactivity on the day of supply) to (radioactivity on the day of expiration). The factors that influence administered activity are throughput, price of the radionuclide, and whether the radionuclide is sold as a single vial. In order to decrease the effective dose, it is necessary to establish a close cooperation between medical personnel, the makers of radiopharmaceuticals, and manufacturers of gammacameras.
Humans↗
[Fundamental study of helical scanning CT--evaluation of spatial resolution in the longitudinal axis].
We evaluated spatial resolution in the longitudinal axis with helical scanning CT using a fourth-generation fast CT scanner. We made a phantom by stringing acrylic balls (65 mm phi x 8 and 9 mm phi x 6). The acquired images were processed by MPR and assessed visually to evaluate axis resolution. With the conventional scanning method, the partial volume effect varied with the starting position, but helical scanning was able to reconstruct high-resolution images using continuous raw data. During helical scanning, axis resolution varied depending on the slice width and sliding speed of the couch top. Even if the sliding speed was kept constant at 4 mm/sec, axis resolution was superior with a slice width of 2 mm than with one of 5 mm.
Microcomputers↗
A high involvement of O2- possibly generated in inner membranes for iron-induced microsomal lipid peroxidation.
The lipid peroxidation of and the O2- generation by rat liver microsomes in the presence of NADPH or both NADPH and Fe3+ were determined by thiobarbituric acid-reacting substance formation and by chemiluminescence intensities with a cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3, 7-dihydroimidazo[1,2-a]pyrazin-3-one(MCLA), as a chemiluminescence probe. Judging from the experiments with various inhibitors on the O2- generation and the lipid peroxidation, O2- generated, at intramembranous site, by cytochrome P-450 system is considered to be highly involved in the iron-induced lipid peroxidation.
Animals↗
Hepatitis B virus, cigarette smoking and alcohol consumption in the development of hepatocellular carcinoma: a case-control study in Fukuoka, Japan.
The roles of the hepatitis B virus (HBV), cigarette smoking and alcohol consumption in the etiology of hepatocellular carcinoma (HCC) were examined in a case-control study involving 204 patients with HCC and 410 control subjects in Fukuoka prefecture, where HCC risk is among the highest in Japan. Information on smoking and drinking habits was obtained by a detailed interview survey, and the results were analyzed in conjunction with serum hepatitis B surface antigen (HBsAg) status after adjustment for sex, age and other possible confounding factors. Individuals positive for serum HBsAg showed a relative risk (RR) for HCC of 13.8 (95% confidence interval, Cl 5.9 to 32.5), whereas heavy drinkers experienced about a 2-fold risk increase compared with non-drinkers. Light or moderate drinkers, however, demonstrated RRs near the unity. Some risk excess was observed among ex-smokers (RR = 1.5, 95% CI 0.8 to 2.8) and current smokers (RR = 1.5, 0.8 to 2.7) compared with non-smokers, but without evidence for a dose-response relationship in terms of pack-years. Analysis among HBsAg-negative subjects revealed similar non-significant association with smoking, and there was no clear interaction between alcohol and cigarette consumption on HCC risk. Other significant risk factors included positive histories of blood transfusion (RR = 3.7, 2.2 to 6.3) and familiar liver disease (RR = 2.6, 1.6 to 4.2). Attributable risk calculations suggest that chronic HBV infection and heavy drinking may account for 17% and 13% of HCC occurrence, respectively, in this high risk area. The association of cigarette smoking with HCC was not evident in our study.
Adult↗