[Studies on hypoglycemic compounds. I. Screening of hypoglycemic compounds].
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Biomedical subjects
Publications and source records attributed to Y Abe.
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This study was undertaken to determine whether phased array breath-hold T1- and T2-weighted sequences can replace non-breath-hold spin echo (SE) sequences in the imaging of focal liver lesions by comparing overall image quality, liver-lesion contrast, and artifact. Both breath-hold and non-breath-hold T1-weighted and T2-weighted imagings of focal liver lesions were prospectively compared in 120 patients with suspected focal liver lesions imaged at 1.5 T with use of a body phased array multicoil. Breath-hold images were acquired with T1-weighted fast low-angle shot (FLASH) and T2-weighted turbo spin echo (TSE) sequences, and non-breath-hold images were made with conventional T1- and T2-weighted SE sequences. Qualitative image analysis was done by three blinded readers, and quantitative analysis was done. The highest signal-to-noise ratios were obtained with breath-hold T1-weighted FLASH sequence. The signal-to-noise ratios of breath-hold T2-weighted TSE sequence were slightly inferior to those of non-breath-hold SE sequence. Both T1-weighted and T2-weighted breath-hold sequences had less image artifact. Overall image quality of breath-hold sequences was better than that of non-breath-hold sequences for both T1- and T2-weighted sequences (P < .01). The tissue contrast of T1-weighted FLASH sequence was superior to that of SE sequence (P < .01). On T2-weighted imaging, tissue contrast of solid lesions was better on conventional SE sequence than that on breath-hold TSE sequence (P < .01). Respiratory ghost artifact was less prominent on T1-weighted FLASH sequence, although this artifact was occasionally seen on breath-hold T2-weighted TSE sequence. In a state-of-art MR unit with use of a phased array multicoil, conventional T1-weighted can be replaced by breath-hold sequences. On T2-weighted imaging, because solid tumor-liver contrast on breath-hold TSE imaging is inferior to that on non-breath-hold SE image, breath-hold imaging may not replace conventional non-breath-hold T2-weighted SE sequence.
So that we might evaluate the ultrafast half-Fourier single-shot turbo spin-echo (HASTE) sequence in T2-weighted MRI of the female pelvis and compare it with the turbo spin-echo (TSE) sequence, we prospectively studied 60 consecutive females with suspected abnormalities of the pelvis. For all MR examinations, we used a 1.5-T superconductive magnet with a phased array coil. The HASTE sequence was applied with TR/effective TE/echo train = infinity/90/64 and a 128 x 256 matrix (acquisition time: .3 sec/slice), conventional TSE imaging with 3,400 to 5,000/132/15 and a 128 x 256 matrix (mean acquisition time: 2 min 4 sec), and high-resolution TSE imaging with 3,400 to 5,000/132/15 and a 300 x 512 matrix (6 min 4 sec). Although the lesion conspicuity for the HASTE sequence was less than that for the high-resolution TSE sequences, artifacts (including ghosting, bowel motion, susceptibility difference, and chemical shift) were negligible on HASTE images of all patients. The lesion conspicuity for the HASTE sequence was significantly better than for the conventional TSE sequence. In spite of the very short acquisition time, the subjective scoring of the overall image quality for the HASTE sequence was significantly higher than for the conventional TSE sequence (P < .01) and were slightly lower than for the high-resolution TSE sequence. Compared with high-resolution TSE, HASTE provided clearer visualization of large leiomyomas and ovarian tumors but slightly poorer visualization of uterine cancer. In occlusion, HASTE sequence generates higher contrast and is free from motion and chemical shift artifact with much higher time efficacy. Because of limited image resolution, the HASTE sequence should be used when the high-resolution TSE imaging is suboptimal.
Hemopoietic progenitor cells are present in minute numbers in the peripheral blood of healthy adults. By in vitro colony-assays evaluating BFU-E- and CFU-GM-growth, their numbers have been estimated to be about 1,000 per 1.0 ml of whole blood. Employing a CD34-moAb, detecting an antigen present on virtually all hemopoietic progenitor cells, and by using multiparameter flow-cytometry, we have designed a flow-cytometric method for the quantitation of CD34(+)-cells in blood. Comparative studies on bone marrow and blood have shown that CD34(+)-cells from both sources display almost identical light-scatter characteristics. They differ, however, with regard to the coexpression of the CD33- and the CD19-antigens. In vitro colony-assays for BFU-E and CFU-GM in single cultures have shown that about 25% of the CD34(+)-cells from blood were clonogenic in vitro. Our data indicate that the CD34(+)-cells from peripheral blood differ substantially from bone marrow CD34(+)-cells.
The amplitudes of transient and steady-state visual evoked potentials (VEPs) were measured during hemifield stimulation of the left eye in 10 healthy adults. Pattern reversal of a checkerboard was produced at 4 stimulation frequencies: 1, 5, 10 and 15 Hz. The amplitudes of pattern VEPs were evaluated using the paired t test to determine significant differences between right and left hemifields. The transient VEP amplitudes from midoccipital, midparietal, ipsilateral occipital and contralateral occipital electrodes were significantly greater with right hemifield stimulation. The steady-state VEP amplitudes from the midoccipital electrode during 15 Hz stimulation were significantly greater with right hemifield stimulation. Our neurophysiological data may be compatible with neuroanatomical asymmetries of the occipital lobes in humans.
We report a case of intraabdominal panniculitis. Computed tomography (CT) showed diffuse increased attenuation in the omentum, mesentery, and retroperitoneal region. As the disease progressed, the entire mesentery and retroperitoneal regions were involved. On magnetic resonance imaging (MRI), the lesion demonstrated an intermediate signal intensity on T1-weighted images and a slightly high signal intensity on T2-weighted images. Though the radiologic findings are not specific, this condition should be considered in the appropriate clinical context.
The role of two genes, mlcR and ariB, was investigated by gene disruption experiments. The mlcR gene in the ML-236B biosynthetic gene cluster of Penicillium citrinum encodes a putative 50.2-kDa protein with a Zn (II) 2Cys6 DNA-binding domain, and has similarity to most of the GAL4-type regulatory proteins. The mlcR disruptant did not produce ML-236B or its intermediates, suggesting that mlcR is involved in ML-236B biosynthesis. Transcriptional analysis of the mlcR disruptant by Northern hybridization and RT-PCR indicated that MlcR activates the transcription of mlcA, B, C,D, F, G and H in a pathway-specific manner. On the other hand, MlcR did not affect the transcription of mlcE and the genes outside the ML-236B cluster. The ariB gene, next to mlcR, encodes another GAL4-type protein. Transcriptional analysis of the ariB disruptant indicated that it is a transcriptional activator of the genes outside the ML-236B cluster, and is not related to ML-236B biosynthesis.
Insulin, glucagon and somatostatin (SLI) in the pancreas and the gastrointestinal tissue of rats were measured following a high (300 mg/kg) or low (150 mg/kg) dose of cysteamine, given intermittently for 14 days. In addition, the effect of prolonged cysteamine-induced depletion of pancreatic SLI upon the cell distribution within the Langerhans islets was compared with that of chronic insulin-deficient rats produced by streptozotocin. The high or low dose of cysteamine reduced pancreatic SLI to 8.3% and gastrointestinal SLI to 5.6% of control levels without duodenal ulcer. The high dose of cysteamine also reduced pancreatic insulin to 37% of controls without hyperglycemia. No change in the glucagon concentration was observed. In SLI-deficient rats, distribution of A and B cells was similar to that of controls, even though D cells were rarely seen. In insulin-deficient rats, however, the number of A and D cells per islet area increased with a concomitant decrease in B cells. Intermittent administration of a low dose of cysteamine, thus, appears to be useful to produce a chronic SLI-deficient rat. However, a high dose of cysteamine is not a specific depletor of pancreatic SLI. Although insulin may be important to maintain normal cell distribution within the islets, pancreatic SLI may not have such a role.
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The clinical significance of magnetic resonance cholangiopancreatography (MRCP) using half-Fourier acquisition single-shot turbo spin-echo (HASTE) in the evaluation of congenital anomalies of pancreaticobiliary tract was demonstrated in 56 patients (man: 31, women: 25; age: 0-60 years old, mean 15 years old) with suspected congenital anomalies of pancreaticobiliary tract. The image quality and characteristics were assessed. MRCP using HASTE with a phased array coil can be used as a non-invasive method for the evaluation of congenital anomalies of the pancreaticobiliary tracts.
A rare case of transitional cell carcinoma (TCC) with extension into the renal vein and inferior vena cava (IVC) is presented. Computed tomography, magnetic resonance imaging, and angiography successfully delineated tumor thrombus in the right renal vein and IVC. TCC should be included in the differential diagnosis of renal tumors that can cause IVC thrombosis.
We prospectively compared standard resolution and high resolution breath-hold T1- and T2-weighted images of the upper abdomen with use of a body phased-array multicoil in 30 patients. The image quality of high resolution T1-weighted FLASH sequence was equal to that of standard resolution sequence, while the quality of high resolution T2-weighted turbo spin-echo sequence was slightly inferior to that of standard resolution sequence. The merit of high resolution image is appreciated especially on a T1-weighted FLASH sequence.
This study investigates the impacts of effective TE (TEeff), echo spacing and echo train lengths (ETLs) on the imaging quality of HASTE sequences for liver imaging through a slit and a liver phantom. The HASTE sequence with a short echo spacing demonstrated higher CNR for a phantom simulating hepatocellular carcinoma (HCC) than that with long echo spacing. With a long echo spacing, the HASTE sequence showed higher spatial resolution for hemangiomas and metastasis. The improvement of spatial resolution along with the increase in ETLs (imaging matrix) was more prominent for hemangioma than for HCC.
The aim of this work was to evaluate the value of echo-planar imaging (EPI) in the detection of hepatocellular carcinomas arising in a chronic liver damage to respiratory triggered turbo spin-echo (TSE) imaging. With spin-echo EPI sequences, better lesion-liver contrast was obtained than TSE imaging. Although severe artifact is seen, this imaging produce good contrast, and may be useful as an adjunct to TSE imaging in evaluating patients with chronic liver damage.
We reported a case of first reported pulmonary infection due to Mycobacterium fortuitum (M. fortuitum) with massive hemoptysis, successfully treated by bronchial artery embolization (BAE). A 78-year-old male was admitted to our hospital complaining of massive hemoptysis. A biochemical examination and DNA/DNA hybridization revealed M. fortuitum in the culture of his sputum. He was treated by BAE, and antituberculous agents and levofloxacin. The patient remains well without recurrence more than one and a half years after the admission.
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A practical model (Model-1) of a jellyfish valve was developed, which was composed of a valve seat and a flexible membrane. The valve seat has 12 spokes to hold the membrane, and is made of solution-cast polyurethane coated with segmented polyurethane or Cardiothane. The flexible membrane is 200 microns thick, and made of segmented polyurethane or Cardiothane by a casting method. The valves were built into a sac type blood pump. In mock circulation tests, this jellyfish valve revealed performance superior to Bjork-Shiley (B-S) valves. No stagnation point was observed in the flow visualization study, and durability testing is ongoing beyond 7.5 months. The valves were used in animal artificial heart experiments for up to 112 days with good performance. No thrombi were formed on the valve membrane or around the spokes. Although a ring thrombus was observed behind the valve, it would be prevented by perfect adhesion of the valve seat to the blood pump. The plasma free hemoglobin level was less than 2 mg/dl during these experiments. These results suggest that a jellyfish valve (Model-1) is useful in ventricular assist devices, and in short-term bridge use of a total artificial heart.
By fixing the function of one ventricle, a total right heart bypass model can clarify the function and regulatory mechanism of the natural heart, and the etiology of abnormal hemodynamics in TAH animals such as increased CVP blood pressure and hepatic congestion. The pulmonary artery of a right heart bypass in a goat was clamped proximally; the pulmonary circulation was thus supplied entirely by the artificial heart and the systemic circulation by the natural heart. This model enabled studies of long-term effects of an artificial right heart on systemic circulation at a right heart output of 80-100 ml/kg/min; the response of the natural left heart to changes in output of the right heart; and the response of the natural left heart and artificial right heart to treadmill exercise. It was found that only slight increase in CVP or no increase in blood pressure was observed during the experiment (112 days); a rapid increase in output of the RAH resulted in an increase in left atrial pressure, stroke volume and output of the left ventricle, and a decrease in its heart rate at rest; and significant increase in both artificial right heart and natural left heart output and heart rates were observed during treadmill exercise, despite the marked decrease in left atrial pressure. The above results suggest that the increase in CVP and blood pressure in total artificial heart animals are not due to factors involving the artificial right heart, and that although left ventricular function acts in accordance with Starling's law at rest, this is no longer true during treadmill exercise.