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Biomedical subjects

M J Lee

Publications and source records attributed to M J Lee.

At least 73 records · Page 4Linked to original sources
PubMed2001

Assessment of Crohn's disease activity by Doppler sonography of the superior mesenteric artery, clinical evaluation and the Crohn's disease activity index: a prospective study.

AIM: Recent data have shown that superior mesenteric artery (SMA) flow rates are significantly increased in active Crohn's disease, suggesting that SMA flow may be a useful, non-invasive index of disease activity. The aim of this prospective study was to evaluate the use of SMA Doppler sonography as an indicator of Crohn's disease activity and to compare with clinical evaluation and the Crohn's disease activity index (CDAI). MATERIALS AND METHODS: Patients with active Crohn's (n = 19), inactive Crohn's (n = 17) and control subjects (n = 17) were evaluated. Categorization of disease activity was based on a reference standard. CDAI scores were also calculated independently. The SMA flow parameters evaluated were resistive index, pulsatility index, end diastolic velocity, peak systolic velocity, time averaged maximum velocity, cross-sectional area and maximum flow volume. RESULTS: Using a three-group ANOVA for each of peak systolic velocity (PSV) (P = 0.01), end-diastolic velocity (EDV) (P = 0.04), pulsatility index (PI) (P = 0.003), time-averaged maximum velocity (TAMV) (P = 0.05), and maximum flow volume (TAMV.CSA) (P = 0.01), there was a significant effect of group. Using post-hoc tests, only EDV (P = 0.01), TAMV (P = 0.02) and TAMV.CSA (P = 0.003) were significantly different between active and inactive Crohn's disease, though with considerable overlap of values for EDV and TAMV. The mean CDAI scores were significantly different between patients with active Crohn's (287) and inactive Crohn's (71) (P = 0.0001) and correlated well with the reference standard. CONCLUSION: Only three of several parameters previously described as allowing Crohn's disease activity assessment actually did so in our study. However, for two of these parameters (EDV, TAMV), there was overlap between the measurements in the active and inactive groups, thus limiting the ability to discriminate disease activity in practice. The degree of overlap for maximum flow volume (TAMV.CSA) between active and inactive disease was considerably less and this parameter may be more discriminatory of disease activity. On the other hand, we found CDAI scores to be accurate in disease categorization. We agree that there appear to be hyperdynamic changes in active Crohn's disease but suggest that Doppler ultrasound assessment does not reliably assess disease activity in routine clinical practice.

Adult↗
PubMed2001

A critical birth weight and other determinants of survival for infants with severe intrauterine growth restriction.

Our objective was to assess the perinatal management and neonatal outcomes of premature, severely intrauterine growth-restricted (IUGR) neonates. A cohort of neonates <1000 grams, < or = first percentile for weight, and <37 weeks' gestation was identified and matched 2:1 to two control sets of premature, appropriate-for-gestational age (AGA) infants-one with similar gestational age (AGA-GA group) and the other with similar birth weight (AGA-BW group) to determine the effect of IUGR on the outcome of the premature infant. The IUGR group was then examined in detail for descriptive statistics. Data were analyzed by t-tests and Chi-square analyses where appropriate. The IUGR infants had worse outcomes than AGA-GA controls but had somewhat better results than the AGA-BW controls. In the IUGR group, a birth weight less than 550 grams was significantly associated with neonatal death (p < 0.001). However, increasing gestational age was not associated with neonatal survival (p = 0.661) if birthweight remained below 550 grams. Classical cesarean delivery was associated with neonatal death (p = 0.003). Neonatal variables associated with poor outcome included patent ductus arteriosus (p = 0.034), feeding intolerance (p = 0.046), and failure to thrive (p = 0.05). Overall, neonatal survival was 73%. Of the surviving neonates, 69% had evidence of neurodevelopmental delay when tested at 6 and 12 months. Premature, growth-restricted neonates with birth weights of <550 grams versus those of >550 grams have dismal outcomes despite a gestational age that is compatible with survival.

Adult↗
PubMed2001

Helical CT evaluation of the perirenal space and its boundaries: a cadaveric study.

PURPOSE: To determine whether the perirenal spaces communicate across the midline and with the pelvic extraperitoneal spaces. MATERIALS AND METHODS: Helical CT was used to guide the sequential injection of 100-mL intravenous boluses of dilute contrast medium, up to 300 mL, into the perirenal space of eight embalmed cadavers (three male, five female; mean age at death, 82 years; range, 72-93 years), with four left-sided and four right-sided injections. All images were acquired after the final injection (300 mL total) to facilitate coronal and sagittal reconstruction of relevant images. All images were reviewed to assess the flow pathways of contrast medium from the perirenal space to other retroperitoneal spaces. RESULTS: In three cadavers that received left perirenal space injections and in two cadavers that received right perirenal space injections, communication was seen with the contralateral perirenal space through an area anterior to the aorta and inferior vena cava. In three cadavers that received right perirenal space injections, contrast material flowed from the right perirenal space to outline the bare area of the liver. Communication between the perirenal and pelvic extraperitoneal spaces was seen in all eight cadavers; contrast material extended into the pelvic extraperitoneal and presacral spaces. CONCLUSION: These findings show that the perirenal spaces communicate with each other across the midline and with the pelvic extraperitoneal spaces. Clinical implications are that perinephric collections can potentially flow into the pelvis or across the midline.

Aged↗
PubMed2001

Distribution of study designs in four major US journals of obstetrics and gynecology.

OBJECTIVE: To classify and compare articles, based on the study design, in four leading US obstetrics and gynecology journals. METHODS: One year of each journal, American Journal of Obstetrics and Gynecology (AJOG), Obstetrics and Gynecology (O&G), Gynecologic Oncology (GO), and Fertility and Sterility (F&S), beginning May 1997, was reviewed. Supplementary issues were excluded from review. The percentage of articles devoted to observational versus experimental study design was determined, and the quality of evidence was assessed including how heavily randomized controlled trials were represented versus other study designs. RESULTS: 1,517 articles were reviewed. The average percentage of clinical research articles was 90.4. The percentage of animal studies were 10.7 (AJOG), 1.1 (O&G), 1.1 (GO) and 4.2 (F&S) (chi(2) p < 0.001). There were 5.3, 1.9, 6.5, and 7.5% basic science articles, respectively (chi(2) p = 0.007). The average percentage of observational articles was 68.2 and that of experimental articles was 14.1. The percentages of total articles classified as controlled experimental were 10.9 (AJOG), 14.6 (O&G), 5.1 (GO), and 15.2 (F&S) (chi(2) p = 0.01). There were 8.7, 11.1, 3.3 and 9.5% randomized controlled trials, respectively (chi(2) p = 0.008). CONCLUSIONS: The majority of research reviewed was clinical, and more than half of the articles were observational. Under the US Preventative Services Task Force rating system, the randomized control trial is given the highest rating - class I evidence. The drive toward evidence-based clinical practice may not be fully supported by researchers in obstetrics and gynecology, as reflected by submissions to and publications in the major obstetrics and gynecology journals.

Animals↗
PubMed2001

Tumor removal enhances immunity induced by B7.1.

Costimulation of tumor T cells by B7.1 has been shown to be important for eliciting cell-mediated anti-tumor immunity. We constructed a stable B7.1 gene transfectant of a poorly immunogenic murine sarcoma, Moloney murine sarcoma virus-induced tumor cell line (MMSV). This transfectant, MMSV-B7.1, failed to produce any tumor development in syngeneic mouse models. When MMSV-B7.1 was simultaneously injected with wild-type MMSV, about half of the coinjected mice remained tumor free and displayed an increase in T cell population, upregulation of the mRNA level of various cytokines such as IL-4, IL-5, IL-10, IL-13, IL-15 and IFN-gamma, and complete rejection of reinjected MMSV. To investigate whether MMSV-B7.1 demonstrates any vaccinal effect, the transfectant was injected following the surgical removal of the primary tumor mass. Following a re-challenge with wild-type MMSV, all vaccinated mice maintained their tumor free status and displayed a rapid recovery of down-regulated cytokine levels. The results suggest that B7.1 vaccination after tumor removal might be useful for the prevention of tumor recurrence.

Animals↗
PubMed2001

Apoptosis of skeletal muscle on steroid-induced myopathy in rats.

Recently apoptotic cell death has been reported in differentiated skeletal muscle, where apoptosis was generally assumed not to occur. To investigate whether apoptosis may contribute to the steroid-induced myopathy, rats treated with triamcinolone acetonide (TA) for 9 days were sacrificed for detecting apoptosis by in situ end labeling (ISEL) and electron microscopy in the soleus muscles. Immunohistochemical stainings of Fas antigen and p53 protein were performed to examine whether apoptosis-related proteins were present in the myopathy. Muscle fiber necrosis and apoptotic myonuclei appeared in the soleus muscles following administration of TA, while control muscles showed no evidences for apoptosis. Fas antigen was not detected in control muscles, but expressed in the soleus muscles of steroid-induced myopathy. Some of the Fas antigen-expressing muscle fibers were positive for ISEL. p53 protein was not detected in any muscle fibers. These findings indicate that TA can induce apoptosis in differentiated skeletal muscles, and Fas antigen might be partly related to apoptotic muscle death in steroid-induced myopathy.

Animals↗
PubMed2001

Foodborne illness outbreaks in Korea and Japan studied retrospectively.

The average prevalence of reported foodborne illness from 1981 to 1995 was 2.44 per 100,000 population in Korea, and 28.01 in Japan. The mean case fatality rate in Korea was 0.74% and in Japan, 0.03%. When both prevalence and case fatality rates in Korea and Japan were compared during the same period, the prevalence in Japan was much higher than that in Korea. However, the case fatality rate of patients in Korea was much higher than that in Japan. The distribution of monthly and seasonal patterns of foodborne illness outbreaks strongly indicate the outbreaks may be associated with climatic conditions, frequencies of national holidays, and vacation seasons. Comparison study indicates that the foodborne illness outbreaks in Korea most frequently involved homemade foods (47% of the total cases); in Japan, restaurants accounted for 31.3%. Foodborne illness cases of bacterial origin in Korea were 59.3% of the total and included Salmonella spp. (20.7%). Vibrio (17.4%), Staphylococcus (9.7%), pathogenic Escherichia coli (2.4%), and other species (9.1%); in Japan, 72.8% of the total cases and the majority of the bacterial foodborne illness was caused by Vibrio (32.3%), Staphylococcus (15.9%), Salmonella (14.2%), pathogenic E. coli (3.0%), and other species (7.2%). In conclusion, the outbreaks of foodborne illness in Korea and Japan may be mainly caused by improper food handling, and their occurrences may be differentiated according to food sources.

Disease Outbreaks↗
PubMed2001

Formation and identification of 4'-O-methyl-(-)-epigallocatechin in humans.

The possible beneficial effects of tea consumption have attracted a great deal of attention. Many of the biological effects have been attributed to tea catechins, but the metabolic fate of these compounds is not clear. In the present study, a major metabolite observed in human blood and urine samples after green tea administration was identified as a O-methylated derivative of (-)-epigallocatechin (EGC) by comparison with products from chemical and enzymatic O-methylation of EGC. The structure of this metabolite was elucidated as 4'-O-methyl-(-)-epigallocatechin (4'-O-MeEGC) by (1)H and (13)C NMR and heteronuclear multiple bond connectivity experiment. The human plasma level of 4'-O-MeEGC reached its peak value within the first 2 h following tea ingestion. Its maximum concentration was 4 to 6 times higher than that of EGC. The half-lives of EGC and 4'-O-MeEGC in the blood were 1.02 +/- 0.07 and 4.39 +/- 1.14 h, respectively. The amount of 4'-O-MeEGC excreted in urine was about 3 times higher than that of EGC, and 88% of 4'-O-MeEGC was excreted in urine within 8 h. The present structural information and concentration-time profile of this metabolite provide the basis for understanding the biotransformation of EGC and for future elucidation of its biological activities.

Catechin↗
PubMed2000

Suppressive effect of penta-acetyl geniposide on the development of gamma-glutamyl transpeptidase foci-induced by aflatoxin B(1) in rats.

The suppressive effects of penta-acetyl geniposide, (Ac)(5)-GP, on the hepatotoxic lesions-induced by aflatoxin B(1) (AFB(1)) were investigated in male Wistar rats. Rats were divided into six groups: groups I and II served as normal and solvent control, respectively; group III was given AFB(1) (2 mg/kg body weight) alone; group IV was given (Ac)(5)-GP (2 mg/kg) alone; and groups V and VI received both AFB(1) (2 mg/kg body weight) and (Ac)(5)-GP (1 mg and 2 mg/kg body weight, respectively). Rats received treatments for 8 weeks, then were maintained on basal diet for 32 weeks. At the end of the experiment (week 40), the liver lesions (e.g. fatty change, eosinophilic and bile duct dilation) and preneoplastic changes in rats of groups V and VI were reduced when they were compared with group III. There were no liver lesions and preneoplastic changes in rats treated with (Ac)(5)-GP alone. Although no differences in the total number of gamma-glutamyl transpeptidase (GGT)-positive foci was observed between the groups treated with AFB(1) along with or without (Ac)(5)-GP, the treatment of (Ac)(5)-GP significantly reduced the number of AFB(1)-induced GGT positive foci (with diameter larger than 0.3 mm). These results indicated that the protective effect of (Ac)(5)-GP on early hepatocarcinogenesis-induced by AFB(1) was associated with the inhibition of GGT foci development.

Aflatoxin B1↗
PubMed2000

Dexamethasone enhances phospholipase D activity in M-1 cells.

Phospholipase D (PLD) is an enzyme involved in signal transduction and widely distributed in mammalian cells. The signal transduction pathways and role for phospholipid metabolism during hormonal response in cortical collecting duct remain partly undefined. It has been reported that dexamethasone increases transepithelial transport in M-1 cells that are derived from the mouse cortical collecting duct. We investigated the expression and activity of PLD in M-1 cells. Basal PLD activity of M-1 cells cultured in the presence of dexamethasone (5 microM) was higher than in the absence of dexamethasone. Dexamethasone and ATP activated PLD in M-1 cells but phorbol ester did not stimulate PLD activity. Vasopressin, bradykinin, dibutyryl cyclic AMP, and ionomycin were ineffective in activating PLD of the cells. The PLD2 isotype was detected by immunoprecipitation but PLD1 was not detected in M-1 cells. Addition of GTPgammaS and ADP-ribosylation factor or phosphatidylinositiol 4,5-bisphosphate to digitonin-permeabilized cells did not augment PLD activity. In intact cells PLD activity was increased by sodium oleate but there was no significant change between dexamethasone treated- and untreated cells by oleate. These results suggest that at least two types of PLD are present in M-1 cells and PLD plays a role in the corticosteroid-mediated response of cortical collecting duct cells.

Animals↗
PubMed2000

An improved method for the determination of green and black tea polyphenols in biomatrices by high-performance liquid chromatography with coulometric array detection.

Tea polyphenols are strong antioxidants and are believed to have beneficial health effects. However, the blood and tissue levels of these compounds are not well characterized because of a lack of suitable analytical methods for the biological resolution of these compounds. Previously, we developed methods for the analysis of three green tea catechins. Now we report an improved method for the measurement of the levels of the different catechins and theaflavins in biological fluids and tissues. The method includes digestion of the plasma, urine, or tissue samples with beta-d-glucuronidase and sulfatase, followed by extraction with ethyl acetate and subsequent separation by reversed-phase high-performance liquid chromatography (HPLC). The polyphenols are identified on the basis of their retention times, spectral analysis, and electrochemical behavior across an array of electrodes. In a single HPLC run, it is possible to determine the major catechins and theaflavins as well as some of the catechin metabolites. The detection limits for catechins and theaflavins are from 5 to 10 ng/ml of saliva, plasma, or urine.

Adult↗