Biomedical subjects
Publications and source records attributed to R Gonda.
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PURPOSE: To determine the relative value of three MRI pulse sequences in defining the prostate volume after permanent implantation. METHODS AND MATERIALS: A total of 45 patients who received a permanent 125I implant were studied. Two weeks after implantation, an axial CT scan (2 mm thickness) and T1-weighted, T1-weighted fat saturation, and T2-weighted axial MRI (3-mm) studies were obtained. The prostate volumes were compared with the initial ultrasound planning volumes, and subsequently the CT, T1-weighted, and T1-weighted fat saturation MRI volumes were compared with the T2-weighted volumes. Discrepancies in volume were evaluated by visual inspection of the registered axial images and the registration of axial volumes on the sagittal T2-weighted volumes. In a limited set of patients, pre- and postimplant CT and T2-weighted MRI studies were available for comparison to determine whether prostate volume changes after implant were dependent on the imaging modality. RESULTS: T1-weighted and T1-weighted fat saturation MRI and CT prostate volumes were consistently larger than the T2-weighted MRI prostate volumes, with a volume on average 1.33 (SD 0.24) times the T2-weighted volume. This discrepancy was due to the superiority of T2-weighted MRI for prostate definition at the following critical interfaces: membranous urethra, apex, and anterior base-bladder and posterior base-seminal vesicle interfaces. The differences in prostate definition in the anterior base region suggest that the commonly reported underdose may be due to overestimation of the prostate in this region by CT. The consistent difference in volumes suggests that the degree of swelling observed after implantation is in part a function of the imaging modality. In patients with pre- and postimplant CT and T2-weighted MRI images, swelling on the T2-weighted images was 1.1 times baseline and on CT was 1.3 times baseline, confirming the imaging modality dependence of prostate swelling. CONCLUSION: Postimplant T2-weighted MRI images provided superior prostate definition in all critical regions of the prostate compared with CT and the other MRI sequences tested. In addition to defining an optimal technique, these findings call two prior observations into question. Under dosing at the anterior base region may be overestimated because of poor definition of the prostate-bladder muscle interface. The swelling observed after implantation was lower on T2-weighted images as well, suggesting that a fraction of postimplant swelling is a function of the imaging modality. These findings have implications for preimplant planning and postimplant evaluation. As implant planning techniques become more conformal, and registration methods become more efficient, T2-weighted MRI after implantation will improve the accuracy of postimplant dosimetry.
Five new xanthones, 1,3,6-trihydroxy-5-methoxy-4-prenylxanthone (1), 1,3,5-trihydroxy-6-methoxy-2-prenylxanthone (2), 1,3,5-trihydroxy-4-(3-hydroxy-3-methylbutyl) xanthone (3), 1,3,6-trihydroxy-4-prenylxanthone (4), 3,6-dihydroxy-1,5-dimethoxyxanthone (5) and one new flavonoid, 3,5,7,4'-tetrahydroxy-2'-methoxyflavone (6) along with seven known xanthones and seven known flavonoids were isolated from the bark of Anaxagorea luzonensis A. GRAY and their chemical structures were determined by means of chemical and spectral studies. Almost all flavonoids and one xanthone (13) showed antioxidant activity.
Three new biphenyl ether lignans, 1, 2 and 3, were isolated from the rhizomes of Curcuma chuanyujin along with curcuminoid compounds 4, 5 and 6 and their chemical structures were determined to be 1-feruloyloxy-2-methoxycinnamic acid, 1-feruloyloxy cinnamic acid and (1-p-hydroxycinnamoyl) cinnamic acid by means of spectral evidence. The latter three known substances showed antioxidant activity.
This report characterizes risk factors in patients who suffer pulmonary embolus (PE) after insertion of vena caval filter (VCF) and formulates an organized diagnostic and therapeutic plan of management. Three hundred eighteen patients were included in a review of patients undergoing insertion of VCF from 1989 to 1995. Ten patients (six men and four women, ages 25-72 years) from this group (3.1%) experienced PE after VCF insertion. Risk factors for deep venous thrombosis were documented in these ten patients. Venacavography was performed after diagnosis of PE. Thrombus length measured from the apex of the filter was used to determine further therapy. Thrombus 5 cm or greater in length was treated with a second VCF (VCF-2). Smaller clots were treated with anticoagulation (AC). All patients treated with AC underwent repeat vena caval study (CT scan or venacavagram) 10 days to 18 months after treatment. PE occurred from 8 days to 5.5 years after original VCF insertion. Five patients suffered PE longer than 6 months (range, 21-66 months; mean, 39 months) after VCF insertion. Venacavagrams demonstrated thrombus in all ten patients with PE. Six patients were treated with VCF-2 and four patients with AC. Dissolution of thrombus was seen on follow-up in all patients given AC. All 10 patients harbored at least two risk factors for deep venous thrombosis. Malignancy was found in only two patients. Five patients were found to have procoagulant states characterized by decreased levels of anti-thrombin III or protein C or S. No postoperative deaths or early recurrent PE occurred. One patient experienced another PE 5 years after treatment with AC when she discontinued warfarin. Contraindications to AC appeared to be self-limited, and all patients were discharged on warfarin. No significant bleeding occurred during early follow-up. Our findings confirm the reliability and low complication rate for VCF. Patients experiencing PE after insertion of VCF mandate an aggressive diagnostic approach that should include venacavography and a search for identifiable risk factors including procoagulant state. Treatment with AC and insertion of a second VCF both give favorable results. All patients appear to benefit from short- or long-term warfarin therapy, and contraindications to AC frequently are self-limited. Therapy based on clot size warrants further study.
An acidic polysaccharide, called peonan PA, was isolated from the root of Paeonia lactiflora PALLAS. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 6.0 x 10(4). Peonan PA is composed of L-arabinose: D-galactose: D-galacturonic acid in the molar ratio of 2:1:10, in addition to small amounts of O-acetyl groups and peptide moieties. About forty percent of the hexuronic acid residues in peonan PA exist as methyl esters. Reduction of carboxyl groups, methylation analysis, lithium degradation and nuclear magnetic resonance studies indicated that its main structural features involve both alpha-1,5-linked L-arabino-beta-3,6-branched D-galactan type and alpha-1,4-linked D-galacturonan type structural units. The polysaccharide exhibited remarkable reticuloendothelial system-potentiating activity in a carbon clearance test and considerable anti-complementary activity.
Controlled Smith degradation and limited hydrolysis of ginsenan PA, the main phagocytosis-activating polysaccharide isolated from the root of Panax ginseng C. A. Meyer, were performed. The reticuloendothelial system-potentiating and anti-complementary activities of the degradation products were investigated. Methylation analysis of the primary and secondary Smith degradation products indicated that the core structural features of ginsenan PA include a backbone chain mainly composed of beta-1,3-linked D-galactose. Almost half of the galactose units in the backbone carry side-chains composed of beta-1,6-linked D-galactosyl residues at position 6. Further 3,6-branching of D-galactose units was observed in a part of the side-chains. alpha-L-Arabinose units are connected mainly to the core galactose moieties via position 6. Removal of most of the arabinose units had a considerable effect on immunological activity.
Two acidic polysaccharides, called rehmannan FS-I and rehmannan FS-II, were isolated from the raw root of Rehmannia glutinosa LIBOSCHITZ. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 5.8 x 10(4) and 6.6 x 10(4), respectively. Rehamannan FS-I is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 68:40:4:84:3; rehmannan FS-II is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid in the molar ratio of 18:15:4:33, in addition to small amounts of O-acetyl groups. About two-thirds (rehmannan FS-I) and about one half (rehamannan FS-II) of the hexuronic acid residues exist as methyl esters. Methylation analysis of the carboxyl-reduced derivatives and nuclear magnetic resonance studies indicated that their structural features include mainly both arabino-3,6-galactan and rhamno-galacturonan type structural units. Both polysaccharides showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test.
An acidic polysaccharide, called pinellian PA, was isolated from the tuber of Pinellia ternata Breit. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 11.8 x 10(4). Pinellian PA is composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratio of 5:15:1:3:3, in addition to small amounts of O-acetyl groups and peptide moieties. Reduction of carboxyl groups, methylation analysis and nuclear magnetic resonance studies show that the core structural features include a backbone chain composed of beta-1,3-linked D-galactose units. Some of the galactose units in the backbone carry beta-1,6-linked D-galactosyl side-chains at position 6. Pinellian PA produces significant potentiation of the reticuloendothelial system, as shown by a carbon clearance test, and also exhibits potent anti-complementary activity.
A glucan, called alisman SI, was isolated from the tuber of Alisma orientale Juzepcz. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was 1.1 x 10(4). It is composed solely of D-glucose. Methylation analysis, nuclear magnetic resonance and enzymic degradation studies indicated that it has a high-branched glucan type structure mainly composed of alpha-1,4-linked D-glucopyranosyl residues with partially alpha-1,6-linked units and both 3,4- and 4,6-branching points. The polysaccharide exhibited significant reticuloendothelial system-potentiating activity in a carbon clearance test, as well as a pronounced anti-complementary activity.
An acidic polysaccharide, called alisman PII, was isolated from the tuber of Alisma orientale Juzepcz. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 5.25 x 10(4). It is composed of L-arabinose:D-galactose:D-glucuronic acid in the molar ratio of 4:9:2, in addition to some of O-acetyl groups. Reduction of carboxyl groups, methylation analysis, nuclear magnetic resonance and controlled Smith degradation indicated that the core structural features include a backbone chain composed of beta-1,3-linked D-galactose units. Some of the galactose units in the backbone carry beta-D-galactosyl side chains at position 6. Both alpha-1,5-linked L-arabinosyl side chains and terminal beta-D-glucuronic acid residues are linked to the core galactan units. Alisman PII showed significant potentiation of the reticuloendothelial system using a carbon clearance test and also potent anti-complementary activity.
A glucan, called pinellian G, was isolated from the tuber of Pinellia ternata BREIT. It was homogenous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 1.5 x 10(4). It is composed solely of D-glucose, in addition to a few O-acetyl groups. Methylation analysis, nuclear magnetic resonance and enzymic degradation studies indicated that it is a branched glucan mainly composed of alpha-1,4-linked D-glucopyranose residues with partially alpha-1,3-linked units and 4,6-branching points. The glucan showed significant reticuloendothelial system-potentiating activity in a carbon clearance test, as well as pronounced anti-complementary activity.
A novel beta-heteroglucan, called cnidirhan SIIA, was isolated from the rhizome of Cnidium officinale MAKINO. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was more than 1 x 10(7). It was composed of D-glucose, D-galactose and L-arabinose in the molar ratio of 85:5:8, in addition to small numbers of O-acetyl groups. Methylation analysis and nuclear magnetic resonance studies indicated its main structural features composed of beta-1,6-linked D-glucopyranosyl residues with both 3,6- and 4,6-branching points. In addition, it has both beta-1,4-linked L-arabinopyranosyl and beta-1,6-linked D-galactopyranosyl residues. The polysaccharide showed very pronounced reticuloendothelial system-potentiating activity in a carbon clearance test, as well as a marked anti-complementary activity.
Two acidic polysaccharides, called rehmannan SA and rehmannan SB, were isolated from the dried root of Rehmannia glutinosa Liboschitz. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 6.4 x 10(4) and 7.9 x 10(4), respectively. They were commonly composed of L-arabinose:D-galactose:L-rhamnose:D-galacturonic acid in the molar ratios of 10:10:1:1 (rehmannan SA) and 14:7:3:8 (rehmannan SB), in addition to small amounts of peptide moieties. About eighty percent (rehmannan SA) and about thirty percent (rehmannan SB) of the hexuronic acid residues exist as methyl esters. Reduction of carboxyl groups, methylation analysis, nuclear magnetic resonance and the controlled Smith degradation studies indicated the structural features of rehmannan SB, the major one in terms of the yield. It has a core structural unit of a characteristic rhamnose-rich arabino-3,6-galactan type. Both polysaccharides showed remarkable reticulo-endothelial system-potentiating activity in a carbon clearance test.
A novel glucan, called cnidirhan SI, was isolated from the rhizome of Cnidium officinale Makino. It was homogeneous on electrophoresis and gel chromatography, and its molecular mass was estimated to be 1.3 x 10(4). It is composed of D-glucose alone, in addition to small numbers of O-acetyl groups. Methylation analysis, nuclear magnetic resonance and enzymic degradation studies indicated it has a high-branched glucan type structure composed of alpha-1,4-linked D-glucopyranose residues with both 3,4- and 4,6-branching points. The glucan showed significant reticuloendothelial system-potentiating activity in a carbon clearance test, as well as pronounced anti-complementary activity. This substance is the first example of a branched alpha-glucan with phagocytosis-stimulating and anti-complementary activities.
Two acidic polysaccharides, called ginsenan S-IA and ginsenan S-IIA, were isolated from the root of Panax ginseng C. A. Meyer. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 5.6 x 10(4) and 1.0 x 10(5), respectively. Ginsenan S-IA is composed of L-arabinose: D-galactose: D-galacturonic acid in the molar ratio of 8:8:1, and ginsenan S-IIA is composed of L-arabinose: D-galactose: D-glucose: D-galacturonic acid in the molar ratio of 15:10:2:5, in addition to small amounts of O-acetyl groups. About a half (ginsenan S-IA) and about a quarter (ginsenan S-IIA) of the hexuronic acid residues exist as methyl esters. Reduction of carboxyl groups, methylation analysis, nuclear magnetic resonance and periodate oxidation studies indicated that their structural features include mainly alpha-1,5-linked L-arabino-beta-3,6-branched D-galactan type structural units. Both polysaccharides showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test and pronounced anti-complementary activity. These substances are the first examples having a relatively high content of both alpha-3,5-branched L-arabinose and beta-1,4-linked D-galactose units among the acidic arabinogalactans with activities on phagocytosis and anti-complement.
A neutral and an acidic polysaccharide, called peonan SA and peonan SB, were isolated from the root of Paeonia lactiflora Pallas. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 11.2 x 10(4) and 25.0 x 10(4), respectively. Peonan SA is composed of L-arabinose: D-galactose: D-glucose in the molar ratio of 1:1:28, and peonan SB is composed of L-arabinose: D-galactose: D-galacturonic acid in the molar ratio of 4:3:2, in addition to small amounts of peptide moieties. About forty percent of the hexuronic acid residues in peonan SB exist as methyl esters. Reduction of carboxyl groups, methylation analysis, nuclear magnetic resonance and periodate oxidation studies indicated that their structural features include mainly 3,4- and 4,6-branched alpha-D-glucan type units (peonan SA) and principally alpha-1,5-linked L-arabino-beta-3,6-branched D-galactan type structural units (peonan SB). Both polysaccharides, especially in peonan SB, showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test and considerable anti-complementary activity.
Two acidic polysaccharides, named ginsenan PA and ginsenan PB, were isolated from the root of Panax ginseng C. A. Meyer. They were homogeneous on electrophoresis and gel chromatography, and their molecular masses were estimated to be 1.6 x 10(5) and 5.5 x 10(4), respectively. They are composed of L-arabinose: D-galactose: L-rhamnose: D-galacturonic acid: D-glucuronic acid in the molar ratios of 11:22:1:6:1 (ginsenan PA) and 3:7:2:8:1 (ginsenan PB), in addition to small amounts of O-acetyl groups. Almost all (ginsenan PA) and part (ginsenan PB) of the hexuronic acid residues exist as methyl esters. Reduction of carboxyl groups, methylation analysis, nuclear magnetic resonance and periodate oxidation studies indicated that their structural features include mainly both alpha-arabino-beta-3,6-galactan type and rhamnogalacturonan type structural units. Both polysaccharides showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test, pronounced anti-complementary activity and alkaline phosphatase-inducing activity in a dose dependent manner.