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81.
Camus Kar Man Choy Pauline Cho Wai-Yuen Chung Iris F F Benzie 《Optometry and vision science》2003,80(9):632-636
BACKGROUND: Tear ascorbate is important for corneal health. A rapid and simple method for measurement of ascorbate in tears is needed, and adequate knowledge of physiological variation of tear ascorbate is important to facilitate comparative studies of the effect of, for example, contact lens wear and environmental conditions and stresses. However, there are currently no data on physiological variation of tear ascorbate. This study validated a simple and speedy method for tear ascorbate and investigated between-eye and between-day variation in tear ascorbate in healthy young adults. METHODS: Yawn-induced reflex tears were collected from 32 healthy Hong Kong Chinese subjects and measured by both high-performance liquid chromatography (HPLC) and by an enzyme-linked colorimetric method known as FRASC (total ferric reducing (antioxidant) activity and ascorbate concentration measurement). For between-eye variation, yawn reflex tears were collected from each eye of the same 32 healthy subjects, and ascorbate was measured using HPLC; in a separate experiment for between-day variation, tears were collected on two separate days from 14 subjects, and ascorbate was measured by FRASC. RESULTS: Both HPLC and FRASC showed high precision, and results obtained using FRASC were not statistically different from those using HPLC; mean +/- SD were, respectively, 18.5 +/- 4.4 microM and 18.5 +/- 4.8 microM for HPLC and FRASC methods (p = 0.943). No significant between-eye difference in tear ascorbate was found (p = 0.386), and no significant between-day variation was found overall: mean +/- SD ascorbate was 20.0 +/- 6.2 microM on day 1 and 19.3 +/- 6.8 microM on day 2 (p = 0.772). However, between-day variation was large in seven of 14 subjects. CONCLUSION: FRASC is an acceptable alternative to HPLC for measurement of tear ascorbate. Tears for ascorbate investigation can be collected from either eye or, if necessary, from both eyes and pooled. However, tear ascorbate may vary widely from day to day in the same individual. The reasons for this variation require further study but may relate to differences in ascorbate supply or demand within the precorneal tear layer. 相似文献
82.
R S Chung 《Annals of surgery》1987,206(3):335-339
Sutureline blood flow was measured with laser Doppler velocimetry in colonic anastomoses created with the stapler, manual suturing, or a combination. Blood flow was always reduced in the sutureline compared with normal mucosa. Of all the anastomoses studied, tight stapling reduced sutureline blood flow the most, whereas the two-layered manual anastomosis or stapling reinforced with sutures were somewhat less ischemic. Stapling adjusted to bowel wall thickness impaired flow only moderately. It was possible with practice to outperform the stapler by single-layered manual anastomosis using fine sutures. In humans, stapled ileocolostomy had a higher sutureline blood flow than the two-layered manual anastomosis. In view of the existing clinical experience of safe stapling without adjustment for bowel wall thickness, a low sutureline blood flow is probably tolerated to a considerable degree in humans. However, this study clearly shows that tight stapling can reduce sutureline blood flow unduly, whereas superior blood supply can be attained by attention to staple closure height relative to bowel wall thickness. 相似文献
83.
84.
The glomerular filtration rate (GFR), renal plasma flow (RPF) and renal blood flow (RBF) were all markedly decreased in rats given an adenine diet as the period of adenine administration lengthened. Concurrently, the urinary excretions of prostaglandin E2 (PGE2) and 6-keto-prostaglandin F1 alpha(6-keto-PGF1 alpha) decreased gradually in parallel with the renal function parameters, whereas the urinary excretion of thromboxane B2 (TXB2) increased markedly. These findings suggest the involvement of prostaglandin in the renal circulation. 相似文献
85.
86.
Dissection and transection of the cystic duct close to the gallbladder has been advocated as a means of avoiding common bile injury during laparoscopic cholecystectomy (LC). We present three cases in which inadequate identification of the gallbladder—cystic duct junction resulted in incomplete cholecystectomy. In two patients an unsecured gallbladder infundibulum presented as cystic duct leaks and one patient developed recurrent symptomatic cholelithiasis. These cases emphasize the need for complete dissection and visualization of the cystic duct at the gallbladder prior its division and secure ligation during LC. 相似文献
87.
Travis L. Boaz Jonathan S. Lewin Yiu-Cho Chung Jeffrey L. Duerk Mark E. Clampitt John R. Haaga 《Journal of magnetic resonance imaging : JMRI》1998,8(1):64-69
The purpose of this study was to determine the suitability of MRI to accurately detect radiofrequency (RF) thermoablative lesions created under MR guidance. In vivo RF lesions were created in the livers of six New Zealand White rabbits using a 2-mm-diameter titanium alloy RF electrode with a 20-mm exposed tip and a 50-W RF generator. This was performed using a 0.2T clinical C-arm MR imager for guidance and monitoring. Each animal was sacrificed and gross evaluation was performed. Histologic correlation was performed on the first two animals. The MR-compatible RF electrode was easily identified on rapid gradient-echo images used to guide electrode placement. A single lesion was created in each rabbit liver. Lesions ranged from approximately 10 to 17 mm in diameter (mean, 13.5 mm). T2-weighted and short T1 inversion recovery (STIR) images demonstrated lesions ranging in diameter from 12 to 18 mm (mean, 14.6 mm). Lesion dimensions determined from images closely correlated with those determined at gross examination with the discrepancy never exceeding 2 mm, for an r2 value of .87. MRI performed at the time of MR-guided RF ablation accurately demonstrated created lesions. This modality may provide a new option for the treatment of local and regional neoplastic disease. 相似文献
88.
D. G. Kim C.-Y. Kim S. H. Paek D. S. Lee J.-K. Chung H.-W. Jung B.-K. Cho 《Acta neurochirurgica》1998,140(7):665-674
Summary
Background To determine its roles in the diagnosis and the systemic evaluation of metastatic brain tumours, whole-body positron emission
tomography (PET) using [18F]FDG was performed in 20 consecutive patients.
Methods
All patients were thought to be suffering or needing to be differentiated from metastatic brain tumours. Nine patients had
multiple brain lesions; six were older and showed a rim-enhancing lesion with surrounding oedema; seven had homogeneously
enhancing periventricular lesion(s) on computed tomography (CT) and/or magnetic resonance (MR) imaging, thought to be central
nervous system lymphomas. Two patients had skull mass(es) and two patients had a solid mass suspected to be, respectively,
a haemorrhagic metastasis and a metastatic malignant melanoma. All of them received whole-body [18F]FDG PET and conventional systemic work-up for metastasis in order to compare the results of the two methods.
Results
Metastatic brain tumours were diagnosed on whole-body [18F]FDG PET in eleven patients who had extracranial and intracranial hypermetabolic lesions. In nine of these, a conventional
work-up also detected primary lesions which on whole-body [18F]FDG PET were seen to be hypermetabolic foci. Systemic lymph node metastases were detected by whole-body [18F]FDG PET only in two patients and histological diagnosis was possible by biopsy of lymph nodes rather than of brain lesions.
In the remaining nine patients who had only intracranial hypermetabolic foci, histological diagnosis was made by craniotomy
or stereotactic biopsy. It was confirmed that seven of nine patients were suffering from a primary brain tumour and two from
metastatic carcinoma. None of the nine showed evidence of systemic cancer on conventional work-up. Histological diagnoses
of the primary brain tumours were four cases of primary central nervous system lymphoma and one each of multifocal glioblastoma,
Ewing's sarcoma, and cavernous angioma.
Patients felt no discomfort during the whole-body [18F]FDG PET procedure and there were no complications. The false negative rate in [18F]FDG PET and in conventional work-up was 15.4% and 30.7% respectively. There were no false positives on either [18F]FDG PET or conventional work-up.
Conclusion
It is suggested that whole-body [18F]FDG PET is a safe, reliable, and convenient method for the diagnosis and systemic evaluation of patients thought to be suffering
or needing to be differentiated from a metastatic brain tumour. 相似文献
89.
Ngai Suk Wai; Tang Oi Shan; Lao Terence; Ho Pak Chung; Ma Ho Kei 《Human reproduction (Oxford, England)》1995,10(5):1220-1222
Intravaginal misoprostol has been shown to be effective forcervical priming before a surgically induced abortion. The objectivewas to investigate the effectiveness of oral misoprostol incervical dilatation prior to vacuum aspiration between the 6thand 12th weeks of pregnancy. The results showed that in nulliparouspatients, the median cervical dilatation in the treatment group(7.8 mm) was significantly greater than that in the placebogroup (3.7 mm). In multiparous patients, the difference wasalso statistically significant (9.8 versus 6.0 mm). The easeof dilatation, assessed subjectively by the operating surgeons,was significantly improved in the treatment group. There wasalso a significant reduction in the duration of the operationand in the mean blood loss in the treatment group. The side-effectsencountered in the treatment group were mild and well acceptedby the women. Oral misoprostol is an effective and safe methodfor cervical dilatation prior to vacuum aspiration in firsttrimester pregnancy. 相似文献
90.
Chung H. Kim MD Alan R. Zinsmeister PhD Juan-R. Malagelada MD 《Digestive diseases and sciences》1988,33(2):193-199
The effect of electrical dysrhythmias on the mechanical activity of the fed stomach was investigated in 5 conscious dogs implanted with Ag-AgCl electrodes and strain gauge force transducers. Each dog was fed 1 can of ALPO® and electromechanical activities of the stomach were recorded for the next 120 min. The results show that intraarterial boluses of met-enkephalin (75 g/kg), PGE2 (36 g/kg), and epinephrine (36 g/kg) induced episodes of antral dysrhythmias whereas saline (1 cc) did not. The postcibal antrat motility index for the test period was not altered following saline injection, but it was reduced by 61%, 70%, and 81% following the administration of met-enkephalin, epinephrine, and PGE2, respectively (p<0.01 vs. baseline period). During periods of normal electrical rhythm, PGE2 and epinephrine significantly reduced the antral motility index (2.07±0.93 and 3.24±0.79, respectively) vs. saline (7.92±0.44) (p<0.05 for both drugs) whereas met-enkephalin (4.98±0.56) did not. In contrast, during episodes of dysrhythmia, met-enkephalin significantly depressed antral motility (1.70±0.74) (p<0.05 vs. periods with normal electrical rhythm) whereas neither epinephrine nor PGE2 caused a further reduction in antral motility from what was seen during periods of normal electrical rhythm (1.84±0.72 and 1.34±0.37, respectively). We thus conclude that intraarterial administration of met-enkephalin, PGE2, or epinephrine induce gastric dysrhythmias postcibally and depress antral contractile activity. The relaxatory effect of met-enkephalin on antral contractions is primarily due to its dysrhythmic effect whereas PGE2 and epinephrine inhibit antral motility even when the electrical rhythm is undisturbed.This work was supported in part by the USPHS, NIH grants AM26428, AM07198, and AM34988 and the Mayo Foundation. 相似文献