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Biomedical subjects

J H Moon

Publications and source records attributed to J H Moon.

At least 19 recordsLinked to original sources

Surgical resection of solitary adrenal metastasis from esophageal carcinoma following esophagectomy.

The prognosis of esophageal carcinoma following esophagectomy is poor due to a high frequency of metastasis to periesophageal lymph nodes and distant organs. However, we experienced a case with good prognosis following resection of a solitary adrenal metastatic tumor. The patient was a 70-year-old man diagnosed with type 2 esophageal cancer (Lt-Ae, T2N1M0, Stage IIB) who was treated with esophagectomy. Eight months following surgery, solitary adrenal metastasis was detected by CT, and was resected. At 42 months follow-up he has had a good quality of life in the community without evidence of recurrence. To the best of our knowledge, only five cases with resected solitary adrenal metastases including our case, have been reported, and show a greater than 1-year survival. Consequently, we suggest that resection of solitary organ metastases is a good alternative, even following esophagectomy.

Adrenal Gland Neoplasms↗

Relationship between inspiratory muscle strength and cough capacity in cervical spinal cord injured patients.

STUDY DESIGN: Prospective single centre study. OBJECTIVES: Pulmonary rehabilitation focuses on improving the expiratory muscle function in order to increase the reduced cough capacity in patients with cervical spinal cord injuries (SCI). However, an improvement in the inspiratory function is also important for coughing effectively. Therefore, this study was to examine the significance of the inspiratory muscle strength on the cough capacity in the patients with a cervical SCI. SETTING: SCI unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: The vital capacity (VC), maximum inspiratory pressure (MIP), and maximum expiratory pressure (MEP) were measured. Moreover, the unassisted peak cough flow (PCF) and assisted PCF under three conditions were evaluated. RESULTS: All three assisted cough methods showed a significantly higher value than the unassisted method (P < 0.001). The VC correlated with the voluntary cough capacity and the MIP (R = 0.749) correlated more significantly with the VC than the MEP (R = 0.438) (P < 0.01). The MIP showed a higher correlation with both the unassisted PCF and all three assisted PCFs than the MEP (P < 0.001). CONCLUSIONS: The management of the inspiratory muscle strength should be considered in the pulmonary rehabilitation at cervical SCI patients.

Adult↗

Endoscopic submucosal resection with double ligation technique for treatment of small rectal carcinoid tumors.

BACKGROUND AND STUDY AIMS: It is difficult to achieve complete endoscopic resection of rectal carcinoid tumors without any procedure-related complications. In this study, we evaluated the efficacy and safety of endoscopic submucosal resection with double ligation (ESMR-DL) for the treatment of small rectal carcinoid tumors. PATIENTS AND METHODS: Eleven rectal carcinoid tumors (in 11 patients) were resected by ESMR-DL between November 2001 and April 2004, using a conventional single-channel endoscope with an attached band-ligator device. The lesion was aspirated into the ligator device and an elastic band was placed around the base; a detachable snare was then used to ligate the stalk below the elastic band; and snare resection was performed above the elastic band. The resected specimens were examined with respect to size, histological atypia, depth of invasion, and the histological appearance of the resection margins. RESULTS: All the lesions were excised completely without any complications. There was no tumor invasion beyond the submucosal layer and there was no evidence of atypia in any of the specimens. Tumor diameter varied from 2.0 mm to 10.0 mm (average 6.2 mm). None of the 11 specimens showed histopathological evidence of tumor involvement at the resection margins. There were no immediate or late complications (bleeding or perforation) after ESMR-DL. There was no local recurrence and there were no distant metastases in any patients during the mean follow-up period of 18 months. CONCLUSION: Endoscopic submucosal resection with double ligation is a useful and safe method for the treatment of small rectal carcinoid tumors.

Carcinoid Tumor↗

Benign breast diseases associated with cyclosporine therapy in renal transplant recipients.

PURPOSE: Our aim was to correlate the radiologic characteristics of cyclosporine-induced benign breast diseases with clinical and pathologic findings. MATERIALS AND METHODS: The clinical, mammographic, and ultrasonographic records of 33 female renal transplant recipients who received cyclosporine were retrospectively reviewed. Eleven patients had 46 breast masses on ultrasonography. We performed core needle biopsies on 20 masses and reviewed the pathologic findings. RESULTS: Among 33 female renal transplant recipients, 11 (33%) had 46 benign breast lesions detected on ultrasonography. We performed core needle biopsies on 20 of the 46 masses. On pathologic examination, 12 were fibroadenomas, 6 showed fibrocystic changes, and 2 revealed dense fibrosis. Regardless of the final pathologic diagnosis, more than half of the lesions revealed severe lymphatic and venular swellings. Among 11 patients with breast lesions on ultrasonography, 10/11 (91%) showed multiplicity, and 7/11 (64%) bilaterality. Mammographically, patients with breast lesions revealed heterogeneous or extremely dense breast patterns, and 8 of 11 patients, circumscribed masses. Twenty-two patients without breast lesions showed scattered fibroglandular densities (n = 7), or heterogeneously dense (n = 11) or extremely dense (n = 4) breast patterns, and 3 of 22 patients showed vague or asymmetric densities that needed further evaluation. CONCLUSION: The development of new breast lesions in patients after renal transplantation should suggest a diagnosis of cyclosporine-induced benign breast disease including fibroadenoma, fibrocystic changes, and dense fibrosis.

Adult↗

Prospective study of the effectiveness of percutaneous transhepatic photodynamic therapy for advanced bile duct cancer and the role of intraductal ultrasonography in response assessment.

BACKGROUND AND STUDY AIMS: We evaluated the therapeutic effects of percutaneous transhepatic photodynamic therapy (PDT) in patients with advanced bile duct cancer. The utility of intraductal ultrasonography (IDUS) for the assessment of responses and for regular follow up after PDT was also examined. METHODS: Percutaneous transhepatic biliary drainage (PTBD) was initiated before PDT. Following dilation and maturation of the PTBD tract, percutaneous PDT was performed. Intraluminal photoactivation was carried out using percutaneous cholangioscopy 2 days after intravenous application of a hematoporphyrin derivative. All patients were additionally provided with percutaneous bile duct drainage catheters after PDT. IDUS was conducted monthly to measure the thickness of the tumor mass before and after PDT. RESULTS: 24 patients with advanced cholangiocarcinomas (Bismuth IIIa, n = 4; IIIb, n = 10; IV, n = 10) were treated with PDT. At 3 months after PDT, the mean thickness of the tumor mass had decreased from 8.7 +/- 3.7 mm to 5.8 +/- 2.0 mm (P < 0.01). At 4 months after PDT, the thickness of the mass had increased to 7.0 +/- 3.7 mm. Quality of life indices improved dramatically and remained stable 1 month after PDT; the Karnofsky index increased from 39.1 +/- 11.36 to 58.2 +/- 22.72 points (P = 0.003). The 30-day mortality rate was 0 %, and the median survival time was 558 +/- 178.8 days (current range 62 - 810 days). CONCLUSIONS: PDT using percutaneous cholangioscopy is safe and effective for advanced hilar cholangiocarcinoma, and seems to prolong survival. IDUS is useful for evaluating changes in the thickness of the tumor mass after PDT.

Adult↗

Invasive intraductal papillary mucinous tumor of the pancreas with simultaneous invasion of the stomach and duodenum.

An 81-year-old woman was admitted with epigastric pain and weight loss. She had been diagnosed with an intraductal papillary mucosal tumor (IPMT) 7 years previously, but had refused surgery for religious reasons. Esophagogastroduodenoscopy revealed a nodular, elevated lesion that was discharging mucin into the duodenal bulb and posterior wall of the upper body of the stomach. Endoscopic ultrasonography, abdominal computed tomography, and endoscopic retrograde cholangiography were carried out, and a highly invasive IPMT with simultaneous invasion of the stomach and duodenum was diagnosed.

Aged↗

Identification of quercetin 3-O-beta-D-glucuronide as an antioxidative metabolite in rat plasma after oral administration of quercetin.

The potential beneficial effect of dietary quercetin (3,3',4',5,7-pentahydroxyflavone) has attracted much attention in relation to the prevention of cardiovascular disease. It is generally recognized that dietary quercetin is subject to metabolic conversion resulting in conjugated forms during absorption and circulation. However, no quercetin conjugates have yet been identified from biological fluids or tissues. In the present study, we isolated and characterized two quercetin conjugates from the plasma of quercetin-administered rats. The blood plasma was collected from 26 rats 30 min after oral administration of quercetin (250 mg/kg body weight), concentrated, dissolved in 2% acetic acid aqueous solution (pH 2.65), and extracted with ethyl acetate. Two compounds (P2, P3) were obtained from the extract by repeated reversed-phase HPLC. On the other hand, two quercetin glucuronides were synthesized chemically and identified as quercetin 3-O-beta-D-glucuronide (Q3GA) and quercetin 4'-O-beta-D-glucuronide (Q4'GA), as determined from FABMS, 1H- and 13C-NMR, and HMBC data. The retention times of P2 and P3 in the HPLC chromatogram corresponded to those of Q3GA and Q4'GA, respectively. FABMS data demonstrated that P2 and P3 are quercetin monoglucuronides. 1H-NMR data for P2 were completely in agreement with those for Q3GA. P2 was therefore identified as Q3GA. This is, to our knowledge, the first evidence that Q3GA accumulates in vivo after oral administration of quercetin. Q3GA is likely to act as an effective antioxidant in blood plasma low-density lipoprotein, because this conjugated metabolite was found to possess a substantial antioxidant effect on copper ion-induced oxidation of human plasma low-density lipoprotein as well as 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity.

Administration, Oral↗

Inhibitory effect of a quercetin metabolite, quercetin 3-O-beta-D-glucuronide, on lipid peroxidation in liposomal membranes.

To study the antioxidant activity of quercetin 3-O-beta-D-glucuronide (Q3GA), which is one of the quercetin metabolites in the blood after intake of quercetin-rich food, the inhibitory effect of Q3GA on lipid peroxidation was estimated using phosphatidylcholine large unilamellar vesicles (PC LUV) as a biomembrane model. Iron ion, an aqueous peroxyl radical generator, a peroxynitrite generator, or lipoxygenase was used as the inducer of lipid peroxidation. In all cases, Q3GA inhibited lipid peroxidation significantly, although its inhibitory effect was lower than that of quercetin aglycon. The ultrafiltration of PC LUV containing Q3GA revealed that Q3GA has low but significant affinity with the membranes of phospholipid bilayers. It is therefore likely that Q3GA acts as an efficient antioxidant in membranous lipid peroxidation through its localization in the phospholipid bilayer. This conjugated quercetin metabolite seems to retain the ability to protect cellular and subcellular membranes from peroxidative attack by reactive oxygen species and peroxidative enzymes.

Arachidonate 15-Lipoxygenase↗

Fixation of a modified covered esophageal stent: its clinical usefulness for preventing stent migration.

BACKGROUND AND STUDY AIMS: Membrane-covered self-expandable metal stents are effective in preventing tumor ingrowth and stent obstruction in patients with inoperable esophageal cancer, but migration of stents continues to be a major problem. We therefore constructed a modified covered self-expandable esophageal metal stent capable of being fixed using a silk thread. The stent was studied prospectively to define its palliative characteristics and whether it is effective in preventing migration. PATIENTS AND METHODS: Modified covered self-expandable metal stents were placed in 17 patients with malignant gastric cardiac cancer involving the esophagogastric junction, 41 patients with esophageal cancer, and three patients with tracheoesophageal fistulas. Clinical and radiographic follow-up examinations were carried out at regular intervals. RESULTS: Placement of the stent was successful in all patients, with good symptomatic relief and no serious stent-related complications such as esophageal perforation or hemorrhage. Acute stent placement problems, such as incomplete expansion or acute angulation of the stent, were noted in four patients. However, during a mean follow-up period of 7.5 months (range 1 to 17 months), there was no stent migration. CONCLUSIONS: Modified covered self-expandable esophageal metal stents of this type would be very effective in preventing stent migration, especially in patients with malignant gastric cardiac cancer extending to the lower esophagus, those with short-segment esophageal cancer, and those with tracheoesophageal fistulas.

Adult↗

The role of percutaneous transhepatic papillary balloon dilation in percutaneous choledochoscopic lithotomy.

BACKGROUND: When choledochoscopic lithotomy with basket and electrohydraulic lithotripsy is used to remove intrahepatic duct stones, fragments or small stones usually remain in the bile duct that are too small to be captured with a basket. METHODS: An attempt was made to remove stone fragments in 16 patients with intrahepatic duct stones by antegrade balloon dilation of the sphincter of Oddi with a conventional balloon catheter. After balloon dilation, remnant stones and sludge were pushed through the papilla with the choledochoscope. RESULTS: Bile duct stones were completely removed in 12 of 16 patients (75%); stones were removed in 1 session. There was no clinical evidence of procedure-related pancreatitis or fatal complications. CONCLUSIONS: Percutaneous transhepatic papillary balloon dilation of the sphincter of Oddi and clearance of remnant bile duct stones and stone fragments with the tip of choledochoscope is simple and effective in patients undergoing percutaneous transhepatic choledochoscopic lithotomy.

Catheterization↗

Protection by quercetin and quercetin 3-O-beta-D-glucuronide of peroxynitrite-induced antioxidant consumption in human plasma low-density lipoprotein.

Effect of quercetin and its conjugated metabolite quercetin 3-O-beta-D-glucuronide (Q3GA), on peroxynitrite-induced consumption of lipophilic antioxidants in human plasma low-density lipoprotein (LDL) was measured to estimate the role of dietary flavonoids in the defense system against oxidative modification of LDL based on the reaction of nitric oxide and superoxide anion. Synthesized peroxynitrite-induced consumption of endogenous lycopene beta-carotene and alpha-tocopherol was effectively suppressed by adding quercetin aglycone into LDL solution. Q3GA also inhibited the consumption of these antioxidants effectively. These results indicate that dietary quercetin is capable of inhibiting peroxynitrite-induced oxidative modification of LDL in association with lipophilic antioxidants present within this lipoprotein particle.

Antioxidants↗

The application of non-parametric statistical techniques to an ALARA programme.

For the cost-effective reduction of occupational radiation dose (ORD) at nuclear power plants, it is necessary to identify what are the processes of repetitive high ORD during maintenance and repair operations. To identify the processes, the point values such as mean and median are generally used, but they sometimes lead to misjudgment since they cannot show other important characteristics such as dose distributions and frequencies of radiation jobs. As an alternative, the non-parametric analysis method is proposed, which effectively identifies the processes of repetitive high ORD. As a case study, the method is applied to ORD data of maintenance and repair processes at Kori Units 3 and 4 that are pressurised water reactors with 950 MWe capacity and have been operating since 1986 and 1987 respectively, in Korea and the method is demonstrated to be an efficient way of analysing the data.

Algorithms↗

Crystallization and preliminary X-ray crystallographic analysis of RNase HIII from Bacillus subtilis.

The genome of Bacillus subtilis contains three different genes encoding RNase H homologs: RNases HI, HII and HIII. RNase HIII from B. subtilis degrades RNA in RNA-DNA hybrids in an Mg(2+)-dependent manner like Escherichia coli RNase HI. However, they belong to different classes; the former belongs to the 'class II' or 'large' RNase H family, while the latter belongs to the 'class I' or 'small' RNase H family. RNase HIII of B. subtilis has been overexpressed in E. coli and crystallized at 296 K using sodium formate as a precipitant. The native X-ray diffraction data have been collected to 2.8 A resolution using synchrotron radiation. The crystals are hexagonal, belonging to the space group P6(1), with unit-cell parameters a = b = 86.89, c = 214.49 A, alpha = beta = 90.0, gamma = 120.0 degrees. A self-rotation function calculation indicated the presence of two monomers of the recombinant RNase HIII in the crystallographic asymmetric unit, giving a V(M) of 3.43 A(3) Da(-1) and a solvent content of 64.2%.

Bacillus subtilis↗

Efficiency of absorption and metabolic conversion of quercetin and its glucosides in human intestinal cell line Caco-2.

The efficiency of intestinal absorption and metabolic conversion of quercetin aglycone and its glucosides, quercetin-4'-O-beta-D-glucoside (Q4'G), quercetin-3-O-beta-D-glucoside (Q3G), and quercetin-3,4'-di-O-beta-D-glucoside (Q3,4'G), was estimated by using Caco-2 cell monolayers as an intestinal epithelial cell model. Aglycone was significantly lost from the apical side, resulting in the appearance of free and conjugated forms of quercetin and those of isorhamnetin in the cellular extracts. In the basolateral solution, the conjugated form of quercetin was predominant and increased with the elapse of incubation. As compared with quercetin aglycone, none of the quercetin glucosides were absorbed efficiently from apical side. However, Q4'G yielded conjugated quercetin and isorhamnetin in basolateral solution at higher amounts than Q3G or Q3,4'G. Lipophilicity of Q4'G was found to be higher than that of Q3G or Q3,4'G. This suggests that lipophilicity contributes to the relatively efficient absorption of Q4'G. It is likely that the occurrence of hydrolysis enhances the efficiency of intestinal absorption and metabolic conversion of dietary quercetin glucosides.

Caco-2 Cells↗

NMR analytical approach to clarify the molecular mechanisms of the antioxidative and radical-scavenging activities of antioxidants in tea using 1,1-diphenyl-2-picrylhydrazyl.

(+)-catechin, ethyl gallate, ascorbic acid, and alpha-tocopherol were reacted with 1,1-diphenyl-2-picrylhydrazyl (DPPH), and the reaction mixtures were subjected to 13C-nuclear magnetic resonance (NMR) analyses to clarify the molecular mechanisms of the antioxidative and radical-scavenging activities of each antioxidant. When ascorbic acid was reacted with DPPH, it was oxidized to dehydroascorbic acid by DPPH. When a mixture of ascorbic acid and (+)-catechin was reacted with DPPH, ascorbic acid scavenged DPPH radical faster than (+)-catechin. Ascorbic acid also scavenged DPPH radical faster than ethyl gallate and alpha-tocopherol. When (+)-catechin was reacted with DPPH, the B-ring of (+)-catechin changed to an o-quinone structure. However, it was reduced to (+)-catechin by ethyl gallate or alpha-tocopherol. alpha-Tocopherol and ethyl gallate had almost identical antioxidative activities. Therefore, the order of radical-scavenging ability (speed) suggested by our 13C NMR study was as follows: ascorbic acid > alpha-tocopherol = ethyl gallate > (+)-catechin.

Antioxidants↗

Accumulation of quercetin conjugates in blood plasma after the short-term ingestion of onion by women.

Quercetin is a typical flavonoid present mostly as glycosides in plant foods; it has attracted much attention for its potential beneficial effects in disease prevention. In this study, we examined human volunteers after the short-term ingestion of onion, a vegetable rich in quercetin glucosides. The subjects were served diets containing onion slices (quercetin equivalent: 67.6-93.6 mg/day) with meals for 1 wk. Quercetin was only found in glucuronidase-sulfatase-treated plasma, and its concentration after 10 h of fasting increased from 0.04 +/- 0.04 microM before the trial to 0.63 +/- 0.72 microM after the 1-wk trial. The quercetin content in low-density lipoprotein (LDL) after glucuronidase-sulfatase treatment corresponded to <1% of the alpha-tocopherol content. Human LDL isolated from the plasma after the trial showed little improvement of its resistance to copper ion-induced oxidation. It is therefore concluded that conjugated metabolites of quercetin accumulate exclusively in human blood plasma in the concentration range of 10(-7) approximately 10(-6) M after the short-term ingestion of vegetables rich in quercetin glucosides, although these metabolites are hardly incorporated into plasma LDL.

Adult↗