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Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 811 records · Page 45Linked to original sources

Plasma levels of proteins of the alternative complement pathway in inbred mice that differ in resistance to Trypanosoma congolense infections.

Inbred BALB/c, A/J, and C57B1/6J mice were infected with Trypanosoma congolense (Trans Mara strain), clone TC13, and monitored for parasitemia, survival times, and plasma levels of complement components C3, C5, factor B, and factor H. Parasitemia was highest in BALB/c, intermediate in A/J, and lowest in C57Bl/6J mice. The mean survival times were 11.5 +/- 0.9, 23.8 +/- 2.3, and 119 +/- 26 days for BALB/c, A/J, and C57Bl/6J mice, respectively. Preinfection levels of factor H were significantly correlated with survival times (r = 0.7722, P less than 0.001). Marked differences were observed between the plasma levels of C3, factor B, and factor H in the 3 mouse strains following infection. Complement C5 levels showed the fewest changes. In the initial postinfection period, BALB/c mice had highest increases in the levels of the 4 complement proteins but also had the greatest declines toward the end of the infection. Factor H levels showed a biphasic increase in BALB/c and C57Bl/6J, but not in A/J mice, with peaks at days 3 and 9. Complement C3 levels declined in all mice toward the terminal stage of the disease. In the late stages of infection, factor B levels markedly decreased in BALB/c but significantly increased in C57Bl/6J mice. Factor B levels measured at the terminal stages in BALB/c, A/J, and C57Bl/6J were correlated positively with their respective survival times (r = 0.714, P less than 0.01). The results suggest that genetic differences in the alternative complement pathway might affect the resistance to T. congolense infections.

Animals↗

Evolution of in vitro transformation and tumorigenesis of HPV16 and HPV18 immortalized primary cervical epithelial cells.

Cervical carcinoma develops through a progressive spectrum of premalignant intraepithelial lesions (CIN I-III), the majority of which are associated with human papillomavirus (HPV) types 16 and 18. We established HPV16 and HPV18 immortalized human cervical epithelial cell lines and used them as a model to investigate the genesis and progression of cervical malignancy. The cell lines when cultured in vitro in a system mimicking their in vivo environment exhibit cytologic atypia and a variety of defects in morphologic differentiation at early passage compared to their normal counterparts. With increased passage, these alterations progress to more severe grades, histologically similar to CIN III; however only a limited number of the cell lines are tumorigenic, mimicking the epidemiologic evidence on the rate of conversion from premalignant to invasive carcinoma. The observed changes are not associated with alterations of viral DNA integration or expression and may reflect specific cellular events or changes in virus-host interactions associated with malignant progression.

Cell Transformation, Neoplastic↗

[Resection of mediastinal teratoma in a patient with cardiac tamponade due to pericardial perforation].

Benign teratoma of the mediastinum causes a variety of complications if left untreated, but reports of pericardial perforation have been rare. We report a case of mediastinal teratoma that perforated the pericardium and induced clinical cardiac tamponade. The patient was a 46-year-old male, who was admitted due to sudden chest pain. Since chest CT and echocardiography suggested perforation of the pericardium by a mediastinal teratoma, pericardial drainage was carried out. However, heart failure could not be resolved, and the tumor was resected on the 5th hospital day. From the intraoperative and pathologic findings, mature type mediastinal teratoma was found to have perforated the pericardium, causing massive influx of yellowish fluid from the cyst of the tumor. There have been only 10 cases reported to date in Japan and abroad in which mediastinal teratoma was complicated by cardiac tamponade.

Cardiac Tamponade↗

Resting metabolic rate and energy balance in amenorrheic and eumenorrheic runners.

This study investigated metabolic and nutritional factors in association with athletic menstrual dysfunction (AMD). Three groups of women were studied: amenorrheic runners (amenorrheic), eumenorrheic runners (eumenorrheic), and eumenorrheic sedentary controls (sedentary). Amenorrheic and eumenorrheic were similar in age, weight, percent body fat by hydrodensitometry, training pace and mileage, best 10 km race time, years running, and maximal oxygen consumption. When adjusted for body weight or for fat-free mass by analysis of covariance, RMR was significantly lower in amenorrheic than in eumenorrheic and sedentary. The daily caloric intakes of the groups did not differ significantly, but the amenorrheic scored significantly higher than the eumenorrheic and sedentary on a scale of aberrant eating patterns. Amenorrheic high mileage runners seem to have a less adequate diet than eumenorrheic runners but appear to maintain energy balance and stable weight through a reduction in RMR.

Adaptation, Physiological↗

Diet, physical activity, and colorectal cancer among Chinese in North America and China.

In a population-based case-control study of colorectal cancer among Chinese men and women in western North America and the People's Republic of China, a common protocol was used to assess past life-style characteristics of 905 cases diagnosed during 1981-1986 and 2,488 controls. Risks for cancers of both the colon and rectum increased with increased food energy from fat, protein, carbohydrate, and all energy sources combined, for both sexes and on both continents. Yet, in multivariate analysis, colorectal cancer risk was significantly associated only with saturated fat; no relationships were seen with other dietary sources of energy. Colon cancer risk was elevated among men employed in sedentary occupations. On both continents and in both sexes, risks for cancers of both the colon and rectum increased with increasing time spent sitting. Further, the association between colorectal cancer risk and saturated fat was stronger among the sedentary than among the active. Risk among sedentary Chinese Americans of either sex increased more than fourfold from the lowest to the highest category of saturated fat intake. Among migrants to North America, risk increased with increasing years lived in North America. These observations suggest (a) that colorectal cancer risk increases with duration of exposure to a sedentary life-style and a diet rich in saturated fat; (b) that higher incidence among Chinese-American men relative to women is due to longer duration of these habits among men, who have lived longer in North America; and (c) that higher risk among Chinese Americans of both sexes relative to risk among the general population in China is due to differences in such habits. Attributable risk calculations suggest that, if these associations are causal, saturated fat intakes exceeding 10 g/day, particularly in combination with physical inactivity, could account for 60% of colorectal cancer incidence among Chinese-American men and 40% among Chinese-American women.

Adult↗

Lung carcinoid cell lines have bombesin-like peptides and EGF receptors.

The biochemical properties of lung cancer cell lines were investigated. Bombesin-like peptides were present in three small cell lung cancer (SCLC) cell lines examined and three of four lung carcinoids but not in five non-small cell lung cancer (NSCLC) cell lines. Therefore SCLC and some lung carcinoids, but not NSCLC, are enriched in neuroendocrine properties. In contrast, 125I-EGF bound with high affinity to all five NSCLC cell lines and three of four lung carcinoids but not to the three SCLC cell lines examined. For lung carcinoid cell line NCI-H727, 125I-EGF bound with high affinity (Kd = 6 nM) to a single class of sites (Bmax = 110,000/cell). The 125I-EGF bound was rapidly internalized at 37 degrees C but not 4 degrees C. Using Western blot techniques and antiphosphotyrosine antibodies, EGF induced phosphorylation of a major 170 Kd protein. Using immunoprecipitation techniques and anti-EGF receptor antibodies a major 170 Kd protein was labeled. These data indicate that biologically active EGF receptors are present on NSCLC and lung carcinoid cell lines.

Adenocarcinoma↗

Cytochemical demonstration of NPPase activity for detecting proton-translocating ATPase of Golgi complex in rat pancreatic acinar cells.

An attempt at cytochemical demonstration of acidification proton-translocating ATPase (H(+)-ATPase) of Golgi complex in rat pancreatic acinar cells has been made by using p-nitrophenylphosphatase (NPPase) cytochemistry which is used for detecting of Na(+)-K(+)-ATPase (Mayahara et al. 1980) and gastric H(+)-K(+)-ATPase (Fujimoto et al. 1986). K(+)-independent NPPase activity was observed on the membrane of the trans cisternae of Golgi complex, but not inside of cisternae. The localization of NPPase activity is different from that of acid phosphatase activity where reaction products were seen on the inside of the trans Golgi cisternae. Since this activity was insensitive to vanadate, ouabain and independent of potassium ions, it was distinct from plasma membranous ATPases such as Na(+)-K(+)-ATPase and Ca2(+)-ATPase. The K(+)-independent NPPase activity was diminished by the inhibitors of H(+)-ATPase such as N-ethylmaleimide (NEM) and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The NPPase reaction products were also seen on the membranes of other acidic organelles, i.e., lysosomes, endosomes, autophagosomes and coated vesicles. These results suggest that NPPase activity on the membrane of the Golgi complex and other acidic organelles corresponds with H(+)-ATPase which plays a role in acidification.

Animals↗

Cerumen phenotype and proliferative epithelium in breast fluids of U.S.-born vs. immigrant Asian women: a possible genetic-environmental interaction.

To determine whether a genetic-environmental interaction exists between the breast, a modified apocrine gland, its secretions, and the genetic polymorphic phenotypes of wet and dry cerumen, we examined nipple aspirate fluid (NAF) for proliferative disease in 172 U.S.-born and immigrant Chinese and Japanese women. Cytologic evidence of proliferative epithelial cells (benign hyperplasia and/or atypical hyperplasia) was found in the NAF of 36 women (20.9%). A significantly higher incidence of proliferative epithelial cells was present in the NAF of U.S.-born than in immigrant Asian women (28.6% vs. 16.5%) (p = 0.05). A higher proportion of U.S.-born Asian women with wet cerumen than women with dry cerumen had proliferative epithelial cells in NAF: 39.3% vs. 20.0% (p = 0.08). No significant difference in NAF proliferative cells was found between immigrant women with wet and dry cerumen: 15.8% vs. 17.3%; p = 0.50. A strong association of proliferative epithelial cells and cerumen phenotype was found in parous U.S.-born women (wet = 47.6% vs. dry = 16.0%; p = 0.002). No significant association with wet and dry cerumen phenotype was found in parous immigrant women (wet = 12.2% vs. dry = 20%). These findings support the hypothesis that an apocrine genetic polymorphic trait differentially influences susceptibility of the breast to proliferative disease in Asian women born in environments presumed to be of high risk for breast cancer compared to women from low risk environments.

Body Fluids↗

Rare HRAS alleles and susceptibility to human breast cancer.

The suggestion that inherited rare alleles at the HRAS oncogene locus might be associated with susceptibility to breast cancer led us to test linkage of HRAS and the neighboring region of 11p15 to breast cancer susceptibility in 12 high-risk families. Linkage could be excluded within 17 cM of HRAS; the lod score for close linkage to HRAS was -19.9. In addition, rare HRAS alleles segregated independently of breast cancer in 8 families in which both occurred. Among unrelated breast cancer patients not selected for family history, rare HRAS alleles were slightly, but not significantly, more frequent than among controls (0.11 vs 0.04, P = 0.11). The HRAS region of 11p is not the site of a primary alteration leading to breast cancer.

Alleles↗

Treatment of Kawasaki syndrome: a comparison of two dosage regimens of intravenously administered immune globulin.

Because intravenously administered immune globulin (IVIG) is effective in reducing the incidence of coronary artery aneurysms in Kawasaki syndrome when given at a dose of 400 mg/kg daily for 4 days, we undertook a multicenter clinical trial comparing two dosage regimens of IVIG. Patients were randomly assigned to receive IVIG at either 400 mg/kg daily for 4 days (22 patients) or 1 gm/kg as a single dose (22 patients). All patients received aspirin therapy, and all were enrolled within 7 days of onset of fever. The presence of coronary artery aneurysms was evaluated by means of two-dimensional echocardiography before infusion; at days 4 to 6, 14 to 21, and 42 to 49 after infusion; and at 1 year. Coronary artery aneurysms were detected in 3 of the 44 patients, including one patient receiving 400 mg/kg and two patients receiving 1 gm/kg (p value not significant). No giant aneurysms were detected. No major side effects occurred with either dosage regimen. Patients receiving the 1 gm/kg dose had a faster resolution of fever and were discharged from the hospital approximately 1 day sooner than the 400 mg/kg group (p = 0.01). Although the relatively small sample size in this trial does not allow for a more definitive statement regarding the occurrence of coronary artery aneurysms, it appears that the 1 gm/kg dose is associated with a more rapid clinical improvement and a shorter hospital stay.

Aspirin↗

Measurement of stiffness during simulated spinal physiotherapy.

A new device was designed to simulate a physiotherapist's assessment of spinal stiffness. The device applies an oscillating postero-anterior force over a spinous process and the force-displacement relation is measured. From these data the stiffness of the movement can be computed. The accuracy and repeatability of stiffness values were found to be high when an elastic beam was tested. Test-retest reliability in 11 human subjects was investigated and found to be good.

Adult↗

Effect of feedback on learning a vertebral joint mobilization skill.

This study was designed to investigate whether concurrent quantitative feedback of performance could improve the learning of a joint mobilization technique. A group of 110 physical therapy students had been randomly divided into two groups for teaching purposes. All students had previously learned mobilization of peripheral joints and were currently learning spinal mobilization. From one of the groups, 22 students volunteered to comprise a control group, which was taught a spinal mobilization technique in the traditional way. Additional concurrent quantitative feedback of the level of force applied to the patient was given to 31 volunteers from the other group. These students formed the experimental group. A force plate was used for force measurement, and the feedback was given via an oscilloscope. The average force applied by the students' instructors was taken as an "ideal" force. The oscilloscope showed both the applied force and the "ideal" force. Consistency was measured by the variance of the group's performance. Accuracy was assessed by calculating the difference between the applied force and the "ideal" force. Results indicated that this feedback was associated with a significant improvement in accuracy and consistency in the application of the mobilizing force. This improvement was still present at a follow-up test conducted one week later. This result supports a greater use of such feedback in the teaching and practice of joint mobilization techniques, although the need for further research is emphasized.

Adult↗

'Acute on chronic' effect of depot leuprolide in patients with stage D2 cancer of prostate.

During a phase III open study of depot leuprolide for stage D2 cancer of the prostate, we studied the effect of depot leuprolide on chronic leuprolide users. To determine whether there was a transient elevation of testosterone or luteinizing hormone (LH) 4-24 h and 3-5 days following the monthly injections, we monitored the changes of testosterone and LH before injection and 24 h post-injection in 10 patients who have been under depot leuprolide Rx for 24-36 weeks, and in 35 patients before injection and 3-5 days post-injection who have received depot leuprolide for 8-24 weeks prior to monitoring. Comparison of the data between pre-injection within 24 h and 3-5 days post-injection showed no significant changes of testosterone and LH values between these levels for either testosterone (P = 0.31) or LH (P = 0.45). We therefore conclude that there was no 'acute on chronic' effect of depot formulation in chronic users of depot leuprolide.

Clinical Trials as Topic↗

Isolation, characterization, and localization of heparin-binding growth factors in the heart.

Acidic and basic fibroblast growth factors (aFGF and bFGF) are angiogenic polypeptide mitogens for cells of mesodermal and neuroectodermal origin. In this report we describe the purification from several normal human hearts (including a very fresh, nonischemic sample) of heparin-binding, acid-, heat- and trypsin-sensitive 14-18-kD peptides that crossreact with antisera against aFGF and bFGF. Further evidence includes (a) prevention of mitogenicity by protamine and by anti-bFGF, (b) displacement of 125I-bFGF from cell membranes, and (c) stimulation of capillary endothelial cell migration. Specific immunohistochemistry localized bFGF to endothelial cells and, surprisingly, to cardiac myocytes, with almost no immunoreactivity in smooth muscle cells. These peptides may function in cardiac embryogenesis, hypertrophy, atherogenesis, angiogenesis, and wound healing, and may also have endocrine, neurotropic, or vasomotor functions.

Aged↗