Biomedical subjects
Publications and source records attributed to S Sumi.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The authors evaluated magnetic resonance (MR) angiography of the portal vein performed with a breath-hold, gadolinium-enhanced, magnetization-prepared rapid acquisition gradient-echo sequence in five volunteers and 24 patients. The main portal vein and its branches and the liver were depicted clearly in all images. The hepatic vein was clearly depicted in 21 of the 24 patients. MR angiography performed with this sequence allowed high-quality imaging of the portal and hepatic veins.
OBJECTIVE: Breath-hold MR urography using half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences was evaluated as a noninvasive alternative to excretory urography in healthy volunteers and in patients with disorders of the urinary tract. SUBJECTS AND METHODS: Twenty healthy volunteers and 45 patients with disorders of the urinary tract underwent HASTE MR urography on a 1.5-T MR imaging unit. Imaging time was 2 sec for single-thick-slice (20- to 60-mm slice thickness) technique and 10-18 sec for multislice technique. In the latter, images were postprocessed with maximum-intensity-projection technique and visualized in an arbitrary plane. Obstruction and its level were determined solely by excretory urography in eight patients, by excretory urography with other imaging techniques (CT, retrograde pyelography, or sonography) in 27 patients, and by sonography alone in the 20 normal volunteers, seven pregnant women, and three patients who were allergic to iodinated contrast media. We evaluated whether HASTE MR urograms showed obstruction, showed the level of obstruction, and showed the cause of obstruction. RESULTS: In all 20 healthy volunteers and all 45 patients, the upper, middle, and lower group of renal calices and the pelvis were clearly revealed by HASTE MR urography. In patients whose urinary tracts were seen on excretory urography (n = 31), the accuracy of HASTE MR urography in revealing urinary tract dilatation and level of obstruction completely correlated with that of excretory urography, although functional information about the obstructed collecting system was not obtained. However, MR urography revealed nonfunctioning urinary tracts that were invisible on excretory urography (n = 6). In patients with extrinsic obstruction (n = 27), MR urography also revealed the obstructing lesions. Small stones within the ureter were more clearly seen on single-shot or source images. With HASTE MR urography, hydronephrosis in pregnant women (n = 7) was clearly shown. CONCLUSION: HASTE MR urography can be used as an alternative to excretory urography to obtain high-quality images of the dilated urinary tract and adjacent abnormalities. HASTE MR urography allows rapid acquisition of images, thus overcoming the drawbacks of earlier MR urography techniques.
To study immunorecognition of free type and complex type prostate-specific antigen (PSA) by current commercial PSA assays, sera from 3 patients with stage D2 prostate cancer were separated by Sephacryl S-200 chromatography and determined by Delfia PSA, ACS-PSA and Eiken PA kits. Two antibodies used in the 3 kits are 2 monoclonal, 1 monoclonal and 1 polyclonal and 2 polyclonal antibodies, respectively. Following chromatography, two PSA peaks were obtained in all patients. One was about 100 kDa and the other about 30 kDa. The former was considered to be the complex type PSA (complex with alpha-1 antichymotrypsin) and the latter to be free type PSA. As to free type PSA, the ACS-PSA kit and Eiken PA kit quantitated PSA values approximately 5.1 and 2.5 times higher than the Delfia PSA kit. For complex type PSA, the quantity determined by ACS-PSA kit was approximately 1.3 times higher than that determined by the Delfia PSA kit, while the quantity determined by the Eiken PA kit was about one third of that determined by Delfia PSA kit. The ratio of complex type PSA to total PSA (free type PSA + complex type PSA) was 74.8 +/- 14.9% (mean +/- SD) when determined by Delfia PSA kit, 59.3 +/- 18.4% by ACS-PSA kit and 52.9 +/- 13.8% by Eiken PA kit. The range of this ratio determined by ACS-PSA kit was from 47.3% to 80.5% in the 3 patients. These findings suggest that there are qualitative differences in immunorecognition of free type PSA and complex type PSA among current commercial PSA assays and that there are quantitative differences in the ratio of the 2 forms of PSA in serum among prostatic cancer patients. The measurement and follow-up of both free type and complex type PSA might be important for diagnosis and monitoring of prostate cancer.
We studied the clinical significance of free-type prostate specific antigen (PSA) and bound-type PSA in serum of the patients with prostatic carcinoma and benign prostatic hypertrophy. The levels of PSA, gamma-seminoprotein and prostatic acid phosphatase (PAP) in 17 healthy adult males, 20 patients with benign prostatic hypertrophy and 23 patients with prostatic carcinoma were measured by ACS-PSA, Delfia and Eiken-PSA method. The levels of PSA in serum from prostatic carcinoma patients was significantly elevated as compared with that from benign prostatic hypertrophy. Linear regression analysis of the data showed that, although overall correlations were well, different assays gave different PSA concentrations. We have studied the forms of PSA in serum by gel filtration technique and measured PSA levels in each fractions using three methods. Moreover, the characteristics of ACS-PSA method was compared with that of Delfia and Eiken-PSA method. Two peaks of PSA were detected on the elution profiles from three prostatic carcinoma patients sera. Those were estimated complex-type PSA (90kDa) and free-type PSA (30kDa). The complex-type PSA fractions detected by ACS-PSA method were almost identical with that detected by Delfia-PSA method, while free-type PSA fractions detected by ACS-PSA method were greater quantity than those by Delfia and Eiken method. Many factors were contributory to the difference between the assay kits on serum complex-type PSA and free-type PSA levels. The present results suggest that there are some quantitative differences in the immunorecognition of complex-type PSA and free-type PSA between the assay kits.
An automated screening system for purine and pyrimidine metabolism disorders using high-performance liquid chromatography (HPLC) with column switching is described. The system consists of a reversed-phase column, a cation-exchange column, a column switch, four sets of ultraviolet absorbance detectors, a microcomputer and other conventional equipment. As this system permits the simultaneous determination of urinary orotic acid, uracil, dihydrouracil, pseudouridine, xanthine, 2,8-dihydroxyadenine and succinyladenosine, it offers a useful method for the detection of orotic aciduria, dihydropyrimidine dehydrogenase deficiency, dihydropyrimidinuria, xanthinuria, adenine phosphoribosyltransferase deficiency and adenylosuccinase deficiency.
Differences between human renal cortex and human renal cell carcinoma (RCC) in asparagine (Asn)-linked sugar chain structures of gamma-glutamyltransferase (GGT) were investigated by using a serial lectin affinity chromatographic technique. The relative amounts of GGT which passed through the concanavalin A (Con A) column but bound to the phytohaemagglutinin E column, were significantly decreased in RCC, but there were significant increases in the relative amounts of GGT which bound weakly to the Con A column and passed through the pea lectin (PSA) column, and bound strongly to the Con A column and bound to the wheat germ agglutinin column in RCC compared with those of the normal renal cortex. A significant correlation was observed in RCC between nuclear grade and relative amount of GGT which bound weakly to the Con A column and passed through the PSA column. The findings indicate that Asn-linked sugar chain structures are altered in RCC and suggest that studies of qualitative differences of sugar chain structures of GGT might lead to a useful diagnostic tool for human RCC.
We report a high-performance liquid chromatographic method with column switching for urinary hypoxanthine and xanthine. Analyses were carried out with both a reversed-phase column and an anion-exchange column connected by a column switch and controlled automatically by a computerized system controller. The relationships between standard concentrations and peak heights were linear in a concentration range of 1 to 1000 nmol/ml. The recovery of hypoxanthine added to urine was 101.1%, and that of xanthine was 98.1%. With our method urinary hypoxanthine and xanthine can be measured accurately without any sample preparation other than filtration.
OBJECTIVE: To use mice to examine the effects of cyclosporine and tacrolimus (FK 506) on two forms of acute pancreatitis often seen after clinical organ transplantation. METHODS AND DESIGN: In the first experiment, male CD-1 mice received cyclosporine (10 mg/kg), tacrolimus (0.32 mg/kg), or saline solution (control) subcutaneously once a day for 10 days. On the 11th day, acute edematous pancreatitis was induced by ceruletide (cerulein). In the second experiment, female ICR mice were fed with a choline-deficient, ethionine-supplemented (CDE) diet for 72 hours to induce necrotizing pancreatitis. After 30 hours on the CDE diet, the mice received cyclosporine (10 mg/kg), tacrolimus (0.32 mg/kg), or saline solution (control) subcutaneously twice daily for 3 days. RESULTS: The pancreatic dry-to-wet weight ratios after ceruletide injections significantly decreased in mice treated with cyclosporine but did not with tacrolimus. Cyclosporine also significantly increased serum amylase levels, but tacrolimus did not. Cyclosporine or tacrolimus alone did not produce pancreatitis. In the CDE diet groups there was a significant difference in survival among the cyclosporine-treated, the tacrolimus-treated, and the control groups. CONCLUSIONS: Cyclosporine or tacrolimus given alone does not induce acute pancreatitis. In contrast, cyclosporine can adversely affect the course of acute edematous pancreatitis, and both immunosuppressants may worsen the survival of mice with acute hemorrhagic necrotizing pancreatitis. This study also demonstrated that the deteriorating effect of tacrolimus is less potent than that of cyclosporine.
Endothelin-1, a 21-residue peptide isolated from vascular endothelial cells, has a broad spectrum of actions. To clarify the involvement of endothelin-1 in acute pancreatitis, we examined the effects of endothelin-1 and its receptor antagonist BQ-123 on cerulein-induced pancreatitis in rats. Rats were infused intravenously with heparin-saline (control), endothelin-1 (100 pmol/kg/hr), cerulein (5 micrograms/kg/hr), or cerulein plus endothelin-1 for 3.5 hr. In another experiment, cerulein or cerulein plus BQ-123 (3 mg/kg/hr) was infused. Infusion of cerulein caused hyperamylasemia and pancreatic edema. Endothelin-1, when infused with cerulein, decreased the extent of pancreatic edema with a significant increase in the pancreatic dry- to wet-weight ratio. Histological changes induced by cerulein were markedly attenuated when endothelin-1 was given with cerulein. In contrast, endothelin-receptor blockade with BQ-123 further augmented pancreatic edema caused by cerulein. The extent of inflammatory cell infiltration was greater than BQ-123 was given with cerulein. Endothelin-1 or BQ-123 had no influence on hyperamylasemia. This study suggests that endothelin-1 has protective effects on experimental acute pancreatitis.
Explore the source record for details and available documents.
The noncoding control region of the mitochondrial DNA of various gallinaceous birds was studied with regard to its restriction fragment length polymorphism (RFLP) and sequences of the first 400 bases. Tandem duplication of the 60-base unit was established as a trait unique to the genus Gallus, which is shared neither by pheasants nor by quails. Unlike its close ally Gallus varius (green junglefowl), the red junglefowl Gallus gallus is a genetically very diverse species; the 7.0% sequence divergence was seen between those from Thailand (G. g. gallus and G. g. spadiceus) and the other from the Indonesian island of Java (G. g. Bankiva). Furthermore, the divergence increased to 27.83% if each transversion is regarded as an equivalent of 10 transitions. On the other hand, a mere 0.5-3.0% difference (all transitions) separated various domestic breeds of the chicken from two G. g. gallus of Thailand, thus indicating a single domestication event in the area inhabited by this subspecies of the red junglefowl as the origin of all domestic breeds. Only transitions separated six diverse domesticated breeds. Nevertheless, a 2.75% difference was seen between RFLP type I breeds (White Leghorn and Nagoya) and a RFLP type VIII breed (Ayam Pelung). The above data suggested that although the mitochondrion of RFLP type V was the main contributor to domestication, hens of other RFLP types also contributed to this event.
Explore the source record for details and available documents.
Lovastatin, an inhibitor of the rate-limiting enzyme of cholesterol synthesis, inhibits growth of pancreatic cancer cells. A possible mechanism of this inhibition is that lovastatin inhibits the activity of RAS protein by depleting farnesyl (an intermediate of cholesterol synthesis). The K-ras gene is frequently mutated in pancreatic cancers and RAS protein requires farnesyl to be bound to the cell membrane and thereby activated. To investigate whether lovastatin inhibition of cell growth depends upon the presence of ras mutation, codons 12/13 and 61 of ras genes were examined by the dideoxynucleotide chain-terminating method in five pancreatic cell lines (human CAPAN2, CAV, MIA Paca2, PANCi, and hamster H2T) on which lovastatin exerted a growth-inhibitory effect. These codons play a major role in tumorigenic mutation of ras genes. Lovastatin inhibited cell growth by 99% (MIA), 97% (H2T), 78% (CAV), 41% (CAPAN2), and 23% (PANC1), respectively, when cells were treated with 2.5 micrograms/ml lovastatin for 6 days. Activating point mutations were found in codon 12 of the K-ras gene (wild type:GGT) in MIA (GTT), H2T (GAT), CAPAN2 (TGT), and PANC1 (GAT) but not in CAV. In addition, the CAV cell line did not have a mutation in either H- or N-ras genes. Lovastatin inhibited the growth of CAV cells even though this cell line did not have ras mutation, suggesting that lovastatin inhibition of pancreatic cancer cell growth is not directly dependent on the presence of ras mutation.
Cionin, a protochordate-derived octapeptide amide related to the gastrin/cholecystokinin family of peptides, contains two consecutive tyrosine sulfate residues. In order to gain insight into the role of the respective tyrosine sulfate residue in biological activity, cionin and its derivatives in which one of the two tyrosine sulfate residues was replaced by tyrosine, were prepared by two Fmoc-based solid-phase approaches. In approach (1) Fmoc-Tyr(SO3Na)-OH was employed as a building block to assemble the Tyr(SO3Na)-containing peptide-resin, and a global deprotection/cleavage was conducted with 90% aqueous TFA in the presence of m-cresol and 2-methylindole at 4 degrees C. In approach (2) the Tyr(Msib) [Msib = p-(methylsulfinyl)benzyl] derivative was used for the peptide-chain assembly to achieve sulfation on the selective Tyr residue. Partially protected peptide with the Msib/Msz protecting groups [Msz = p-(methylsulfinyl)benzyloxycarbonyl], obtained after peptide-resin cleavage, was treated with DMF-SO3 complex in the presence of ethanedithiol to achieve the sulfation of free Tyr residue and the reduction of the Msib/Msz groups to TFA-labile Mtb/Mtz groups [Mtb = p-(methylthio)benzyl, Mtz = p-(methylthio)benzyloxycarbonyl]. Final deprotection of the Mtb/Mtz groups with 90% aqueous TFA in the presence of m-cresol and 2-methylindole gave the desired cionin derivative, which contains the tyrosine sulfate residue at the selective position. Yields obtained with approach (2) were considerably higher than those obtained with approach (1). Cionin and mono-Tyr(SO3H)-containing derivatives were assayed on exocrine pancreas in dogs.
Explore the source record for details and available documents.
Explore the source record for details and available documents.