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Biomedical subjects

M Lee

Publications and source records attributed to M Lee.

At least 1,207 records · Page 67Linked to original sources
PubMedDate not supplied

The isomorphic mapping hypothesis: evidence from Korean.

This paper evaluates the relative merits of the trace deletion hypothesis, which attributes agrammatic comprehension difficulties to the loss of traces, and the isomorphic mapping hypothesis, which proposes that agrammatics have difficulty understanding sentences in which there is a nonisomorphic mapping between the syntactic representation and the corresponding event in the real world. (The two are isomorphic if the order of NPs reflects the place of entities in the event's 'action chain.' Since agents act on themes and transmit them to goals, the agent-theme-goal order is isomorphic with the corresponding event but the agent-goal-theme order is not.) The two hypotheses contrast in the predictions they make concerning goal-theme and theme-goal patterns in Korean: the TDH predicts degraded performance on the theme-goal structure (which is derived from the goal-theme structure); the IMH predicts difficulties on the goal theme structure, since it is nonisomorphic. Results of a comprehension study involving four Korean Broca's aphasics provide strong support for the IMH over the TDH.

Adolescent↗
PubMedDate not supplied

Constituents of Paramichelia baillonii: a new antitumor germacranolide alkaloid.

Paramichelia baillonii has been used by the natives of Northern Thailand for medicinal purposes. Four components have been isolated from the bark of this plant and their structures determined by spectroscopic means. Three of the components had been reported previously: the germacranolide epoxides (--)-dihydroparthenolide [1] and (--)-parthenolide [2] and the oxoaporphinoid alkaloid liriodenine [4]. The fourth component is an unusual new germacranolide alkaloid which has been named (--)-bisparthenolidine [3] because it was presumably formed in the plant from ammonia and two molecules of parthenolide. Parthenolide was reported previously to possess anti-tumor activity, and in the present study we report on the significant activity of the new alkaloid 3 in the KB cell culture assay.

Alkaloids↗
PubMedDate not supplied

Cytochrome P450 enzymes involved in acetaminophen activation by rat and human liver microsomes and their kinetics.

Acetaminophen (APAP), a commonly used analgesic, is catalyzed by cytochrome P450 (P450) enzymes to a toxic intermediate which can be trapped by glutathione. Using this approach, involvement of enzymes in the activation of APAP and their kinetics were studied. With human liver microsomes, there were three apparent Km values (approximately 10,474, and 13,000 microM) for the oxidation of APAP to its glutathione conjugate. With rat liver microsomes (control and ethanol induced) the kinetic data were best fit to a two-Km model (approximately 30 and 1100 microM). Liver microsomes from dexamethasone (DEX)-treated female rats showed a single Km of 56 microM and a Vmax of 7500 pmol of product formed/(min.mg of protein). Antibodies specific for rat P450s 2E1 and 1A2 each inhibited approximately 40% of the APAP metabolism in control male rat microsomes. Only slight inhibition was observed with the P450 3A1/2 antibodies in control male or female rat liver microsomes. Antibodies against rat P450s 3A1/2 inhibited the activity in DEX microsomes by 80%. Antibodies inhibitory to human P450 3A4 inhibited 38% of the activity in human liver microsome sample HL107 and 76% in human microsome sample HL110. Human P450s (2A6, 2E1, 1A2, 3A4, 3A5, 3A3, 2D6, 2F1, 2C8, 2B6, and 2C9) expressed in Hep G2 cells using a vaccinia virus expression system were each tested for APAP metabolism. Of these, P450 2E1, 1A2, and 3A4 showed substantial activity, with respective Km and Vmax values of 680 microM and 330 pmol/(min.mg) for P450 2E1 (with added cytochrome b5), 3430 microM and 74 pmol/(min.mg) for P450 1A2, and 280 microM and 130 pmol/(min.mg) for P450 3A4.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaminophen↗
PubMedDate not supplied

Water-soluble lipopolymer as a gene carrier to corpus cavernosum.

Adenovirus or naked plasmid DNA (pDNA) has been used to deliver the therapeutic gene into corpus cavernosum. However, the potential risks of viral vector and inefficiency of naked pDNA have limited their clinical application. In this study, water-soluble lipopolymer (WSLP) was evaluated as a gene carrier to corpus cavernosum. The WSLP/pDNA complex was transfected to smooth muscle cells in vitro. WSLP had high transfection efficiency, which was comparable to poly(ethylenimine) (PEI). In addition, WSLP had much less cytotoxicity than PEI, suggesting that WSLP is a safer carrier than PEI. To evaluate the transfection efficiency to corpus cavernosum, the WSLP/pDNA complex was injected into the rat corpus cavernosum. As a result, the WSLP/pDNA complex showed higher transfection efficiency than naked pDNA. In addition, the gene expression was dependent upon the dose of the complex. The results suggest that WSLP may be useful for gene therapy of erectile dysfunction.

Adult↗
PubMedDate not supplied

Use of fibrin sealant in thermal injury.

Fibrin glue is hemostatic in skin grafting and other therapeutic situations. This prospective, open-labeled comparative study involved thermally injured patients: 34 patients received fibrin sealant (FS) and 61 did not, at Loyola University Medical Center, Maywood, Illinois, and Shriners Burn Institute, Cincinnati, Ohio. FS-treated patients were 23.6 +/- 16.8 years old, versus 20.8 +/- 16.8 years for controls. The percentage of total body surface areas burn was 10.0% +/- 4.5% in the study patients versus 10.9% +/- 7.9% in the controls. The FS group did not receive packed red blood cell transfusions, albumin infusion, or topical bovine thrombin (TBT). The control group received 1.56 +/- 2.1 units of packed red blood cells, 186 +/- 194 ml 5% albumin, and TBT (20,000 units) 2.6 +/- 0.8 kits during excision and grafting procedures. The estimated blood loss/graft ration was 0.50 +/- 0.30 ml/cm2 (median = 0.46) for the study group versus 0.98 +/- 2.4 ml/cm2 (median = 0.56) for the control group (p = 0.14); for patients more than 16 years of age, this difference was significant (p = 0.03). FS may be a viable alternative to standard hemostatic techniques, because it reduced the need for blood transfusion, alloantigen exposure, and blood-borne viral infection risk. FS also eliminated the need for TBT and epinephrine, did not have an adverse impact on the surgical outcome, and tended to improve the cost differential.

Adolescent↗
PubMedDate not supplied

A multicenter clinical trial to evaluate the topical hemostatic efficacy of fibrin sealant in burn patients.

Current surgical management of deep partial-thickness and full-thickness burn wounds involves early excision and grafting. Blood loss during these procedures can be profound, thus prompting the use of topical hemostatic agents to control and minimize hemorrhage during grafting. The primary endpoint of this multicenter trial was to evaluate the efficacy of fibrin sealant as a topical hemostatic agent during skin grafting. The secondary endpoint was to obtain data to support the existing safety profile of a human fibrin sealant (FS) in participating patients as indicated by the type, severity, and frequency of any adverse events within the 24-hour postoperative period. A multicenter prospective, open label, Phase III multicenter, randomized, comparative clinical trial evaluated the use of fibrin sealant in burn patients undergoing skin graft procedures. Each patient served as his or her own control in this randomized, unblinded study of the effect on time to hemostasis in donor sites treated with the investigational FS product. At operation, 1 contiguous donor skin harvest site was bisected into 2 equal halves, 1 of which was then randomly selected and treated with fibrin sealant. At the end of the fibrin sealant application, the time to hemostasis in each of the donor site halves was identified by the operating surgeon and recorded by the research coordinator. The use of any other topical hemostatic agents was prohibited. A significant difference (P < .001) was demonstrated in the mean time to hemostasis between the fibrin sealant treated donor sites when compared painwise to the control sites. The significant difference was consistent across the 6 participating study centers. There were no adverse events associated with the use of fibrin sealant. The investigational FS product was shown to be efficacious, because it significantly decreases the time to hemostasis at the donor skin harvest site in patients undergoing skin grafting and was noted not to cause any adverse reactions.

Administration, Topical↗
PubMedDate not supplied

High dose cyclophosphamide with carboplatin: a tolerable regimen suitable for dose intensification in children with solid tumors.

PURPOSE: To determine the hematopoietic and nonhematopoietic toxicity of a novel dose-intensive chemotherapy regimen for the treatment of children with relapsed solid tumors. PATIENTS AND METHODS: The time to hematopoietic recovery and toxicity experienced during 46 courses of high-dose cyclophosphamide (4.0 g/m2), MESNA, and carboplatin (400 mg/m2) with granulocyte colony stimulating factor (G-CSF) support in 14 children with recurrent solid tumors was reviewed. RESULTS: All patients developed grade 4 neutropenia and thrombocytopenia. Recovery to an absolute neutrophil count (ANC) of 500/microliter and platelet count of 50,000/microliter occurred at a median of 15 days and 23 days respectively. Median time to ANC > 1,000/microliter and platelets > 100,000/microliter was 27 days. Hospitalization for fever and neutropenia occurred during 35 of 46 courses, with documented bacteremia in six courses. There was no grade II or greater nonhematopoietic organ toxicity. Responses (CR + PR) were observed in 6 of 11 evaluable patients. CONCLUSIONS: These data suggest that this regimen is tolerable in heavily pretreated children with solid tumors with myelosuppression as the primary toxicity. Due to the lack of significant nonhematopoietic toxicity, this is a good candidate regimen for dose escalation using peripheral blood progenitor cell infusions and deserves further evaluation for efficacy in children with both recurrent and newly diagnosed high-risk solid tumors.

Adolescent↗
PubMedDate not supplied

Hormonal changes in rats consuming alcohol prior to and during gestation.

Although the fetuses of rats given alcohol prior to and during gestation are small, the placentas are large compared to those of untreated rats. It has been suggested that placental enlargement may be a consequence of a reduction in progesterone production. To investigate this, rats were given 20% ethanol in water prior to pregnancy and 30% ethanol in water throughout gestation, with rat chow ad libitum (alcohol group) or water with an equicaloric diet in which corn starch was substituted for alcohol (pair-fed group), or rat chow and water ad libitum (as libitum control group). Serum progesterone and testosterone were measured on day 17 of gestation and plasma and pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) on day 21 of gestation. Progesterone was significantly reduced in the alcohol but not the pair-fed group. Testosterone levels were not different among the three groups. Plasma LH was significantly reduced in both the alcohol and the pair-fed groups, but plasma FSH and pituitary LH and FSH did not differ among the three groups. These data are consistent with a possible role for progesterone in the placental enlargement seen in alcohol-fed rats.

Alcoholism↗
PubMedDate not supplied

Hybrid reconstruction algorithm for x-ray computed tomography.

A hybrid reconstruction algorithm (HRA) is derived for fan beam geometry for use with systems utilizing a linear array of detectors. The algorithm uses fan beam geometry with a modified parallel beam reconstruction formula. The parallel beam algorithm is used with fan beam geometry by a simple geometric conversion and a different back projection formula. Correction for center of rotation shift is done during the back projection. Computer simulations are shown, both with the center of rotation shift uncorrected and corrected.

Algorithms↗
PubMedDate not supplied

Are prior head injuries or diagnostic X-rays associated with glioma in adults? The effects of control selection bias.

The causes of glioma, the most common type of primary malignant brain tumors, are poorly understood. This study compares personal histories of head injury and diagnostic radiation procedures of the head and neck among 476 adults newly diagnosed with glioma in the San Francisco Bay Area between August of 1991 and April of 1994 (82% of all those diagnosed during that time period) with 462 age-, gender-, and ethnicity-frequency-matched controls (63% of those eligible from random digit dialing). In addition, limited information was obtained from 101 controls during a brief telephone interview conducted with controls who declined participation in the lengthy in-person interview. Controls who participated in the full interview were much more likely than controls who only completed the telephone interview to report head injury [odds ratios (OR) and 95% confidence intervals (CI) were 2.3 (1.0-4.9) and 3.0 (1.6-5.8) for women and men, respectively]. The OR for any head injury in cases versus controls who completed the full interview was 0.9. However, OR for any head injury in cases versus both control groups was 1.3, 95% CI (1.0-1.7), and the OR for head injury for which the subject sought medical attention was 1.1, 95% CI (0.8-1.4). Among subjects completing the full interview, cases who responded by self-report were less likely than controls to report prior non-dental head and neck X-rays (OR = 0.7; 95% CI: 0.5-1.0). However, stratification by respondents' history of head injury indicated no difference in history of head and neck X-ray among those without prior head injury; OR 0.9; 95% CI (0.6-1.2). Cases and controls shared a very similar history of dental procedures and frequency of dental visits. These results suggest that head injury requiring medical attention, dental visits, or non-dental diagnostic X-rays to the head and neck are not important contributors to the risk of adult glioma and reveal some of the methodological obstacles encountered in forming convincing conclusions about these risk factors for brain tumors.

Adult↗
PubMedDate not supplied

Plasma lipoproteins in familial hepatic lipase deficiency.

We have studied the lipoproteins, apolipoproteins, and postheparin lipase activities in an extended pedigree with familial hepatic lipase deficiency. A deficiency of hepatic lipase was found in three of five brothers and in one of their children. Triglyceride enrichment of low density and high density lipoproteins was identified as the constitutive phenotype. beta-very low density lipoprotein was observed in hepatic lipase-deficient subjects, but it was absent when the plasma triglyceride concentration was less than 1 mM/l. The hepatic lipase-deficient subjects had normal or elevated low density lipoprotein cholesterol and high density lipoprotein cholesterol concentrations. Hyperprebetalipoproteinemia, hyperbetalipoproteinemia, and hyperalphalipoproteinemia were observed in both affected and unaffected family members. Compared with the unaffected family members, the hepatic lipase-deficient subjects had no significant differences in very low density lipoprotein cholesterol, very low density lipoprotein triglyceride, or low density lipoprotein cholesterol. These observations are consistent with the presence of additional genes causing hyperlipidemia in this family, independent of the deficiency of hepatic lipase.

Apolipoproteins↗
PubMedDate not supplied

Regression of metastatic breast cancer in a patient treated with the anti-angiogenic drug TNP-470.

BACKGROUND: Solid tumors in general, and breast cancer in particular, depend on angiogenesis to grow and metastasize. Multiple agents have been developed in order to inhibit this phenomenon of tumor-induced angiogenesis. TNP-470 is one of the most potent of these drugs. We report here a case of regression of metastatic lesions from breast cancer due to the administration of the anti-angiogenic drug TNP-470. METHODS: A 44-year-old woman with a history of stage 2 breast cancer developed metastases at four sites: eye, lung, liver, and bone. She had been treated with radiation, megace, adriamycin, cytoxan, and 5-fluorouracil with disease stabilization. After she completed her radiation and chemotherapy, she was started on TNP-470. RESULTS: In response to TNP-470, her disease showed a partial response at the three-month follow-up and stabilization at the five-month follow-up. There were no side effects, and her quality of life was good. CONCLUSIONS: To our knowledge, this patient is the first reported case of regression of breast cancer metastases as a result of treatment with TNP-470. Anti-angiogenic drugs hold promise for the future therapy of breast cancer, and possibly of many other solid tumors as well.

Adult↗
PubMedDate not supplied

Transcultural nurses reflect on discoveries in China using Leininger's Sunrise model.

This paper is a descriptive report of transcultural nursing discoveries in China. The authors embarked on this study tour led by an experienced transcultural nurse educator which presented a challenging opportunity to discover Chinese culture, lifeways, and health care systems. The authors were challenged to learn about cultural differences and the importance for nurses to use transcultural nursing principles and the Culture Care Theory with research findings about diverse cultures. Leininger's (1991) Theory of Culture Care and Sunrise Model were the conceptual and theoretical guides used to discover the worldview, lifeways, and cultural values of the Chinese people. The Sunrise Model depicts the components of a culture which include worldview, cultural and environmental context, and seven social structure factors. Analysis of these dimensions of the Sunrise Model enabled the authors to discover the important values, beliefs, and lifeways of the Chinese people. Religious and philosophical, kinship and social, political and legal, and economic factors were most important for this culture. In addition culture care expressions, patterns, and practices for health and well being were highly valued by this culture. The Sunrise Model includes diverse health systems which offer generic, folk, and/or professional care. The Chinese culture includes a strong reliance on folk health care systems which persists today. This paper discusses the simultaneous use of folk and professional health care by the Chinese people and implications for transcultural nurses.

China↗
PubMedDate not supplied

Patterns of nasal eosinophilia in allergy clinic patients as determined by swab and curette sampling.

The presence of eosinophils in nasal secretions often characterizes inflammatory disease in the nose and paranasal sinuses. This study analyzed differential associations between various clinical parameters and the presence of nasal eosinophilia in mucosal specimens obtained by two sampling methods (swab and curette-probe). Nasal mucosal secretions were obtained in patients attending an adult allergy clinic using both sampling methods for each patient. The presence of eosinophilia as determined by both methods had significant associations with 1) nasal mucosal pallor, 2) younger age, and 3) the presence of basophilic cells. To examine diagnostic characteristics of the two sampling methods of determining eosinophilia as a characteristic of allergic rhinitis, receiver operating characteristic (ROC) curves were evaluated for patients categorized as having allergic rhinitis on the basis of elevated aero-allergen specific IgE, and rhinitis based on either a) significant nasal mucosal appearance abnormalities, or b) a referring physician's diagnosis of rhinitis. The curette-probe determined nasal eosinophil quantitations had greater areas under the ROC curves when rhinitis was defined on the basis of mucosal appearance. On the other hand, the swab determined eosinophil quantitations had greater ROC curve areas when rhinitis was defined on the basis of referring diagnosis. In summary, nasal eosinophilia determined by curette or swab sampling has differences in strengths of their clinical associations.

Adult↗