Biomedical subjects

J L Lee

Publications and source records attributed to J L Lee.

At least 19 recordsLinked to original sources

PubMed2002

Monitoring the denitrification of wastewater containing high concentrations of nitrate with methanol in a sulfur-packed reactor.

Biological denitrification of high nitrate-containing wastewater was examined in a sulfur-packed column using a smaller amount of methanol than required stoichiometrically for heterotrophic denitrification. In the absence of methanol, the observed nitrate removal efficiency was only about 40%, and remained at 400 mg NO(3)(-)-N/l, which was due to an alkalinity deficiency of the pH buffer and of CO(2) as a carbon source. Complete denitrification was achieved by adding approximately 1.4 g methanol/g nitrate-nitrogen (NO(3)(-)-N) to a sulfur-packed reactor. As the methanol concentration increased, the overall nitrate removal efficiency increased. As influent methanol concentrations increased from 285 to 570, 855, and 1,140 mg/l, the value of Delta mg alkalinity as CaCO(3) consumed/Delta mg NO(3)(-)-N removed increased from -1.94 to -0.84, 0.24, and 0.96, and Delta mg SO(4)(2-) produced/Delta mg NO(3)(-)-N removed decreased from 4.42 to 3.57, 2.58, and 1.26, respectively. These results imply the co-occurrence of simultaneous autotrophic and heterotrophic denitrification. Sulfur-utilizing autotrophic denitrification in the presence of a small amount of methanol is very effective at decreasing both sulfate production and alkalinity consumption. Most of methanol added was removed completely in the effluent. A small amount of nitrite accumulated in the mixotrophic column, which was less than 20 mg NO(2)(-) -N/l, while under heterotrophic denitrification conditions, nitrite accumulated steadily and increased to 60 mg NO(2)(-) -N/l with increasing column height.

Bioreactors↗

PubMed2002

Comparative experiments for in vivo fibroplasia and biological stability of four porous polymers intended for use in the Seoul-type keratoprosthesis.

AIMS: To evaluate in vivo fibroplasia and biological stability of porous polymers intended for use in the Seoul-type keratoprosthesis (S-KPro). METHODS: Four porous polymers (polypropylene, two kinds of polyethylene terephthalate (PE70 and PE50), and polyurethane) were investigated. Discs of polymers were inserted into the corneal stroma of rabbits for a 2 and 5 month period. Corneal oedema and neovascularisation were evaluated. The fibroplasia and collagen deposition were examined under light and transmission electron microscopy. S-KPros, whose skirt was made of four types of polymer, were implanted into the rabbits' eyes. The retention time and complications were evaluated. RESULTS: Neovascularisation and corneal oedema were found in all of the disc inserted eyes, but the corneal oedema subsided within 2 months in most of the eyes. The mean number of fibroblasts increased significantly in polypropylene and PE50 disc inserted eyes compared with polyurethane disc inserted eyes. Plentiful collagen deposition was also found in both polypropylene and PE50 disc inserted eyes. Mean retention time in the polypropylene SK-Pro implanted eyes was longer than that of the other eyes (20.7 weeks). The PE70 skirt induced corneal melting around the prosthesis. CONCLUSION: Polypropylene encourages fibroblast ingrowth and shows good biological stability when used as a skirt material in S-KPro.

Animals↗

PubMed2000

Different generators in human temporal-parasylvian cortex account for subdural laser-evoked potentials, auditory-evoked potentials, and event-related potentials.

In order to localize cortical areas mediating pain we now report subdural cortical potentials evoked by auditory stimulation (auditory-evoked potentials - AEPs) and by cutaneous stimulation with a laser (laser-evoked potentials - LEPs). Stimulation with the laser evokes a pure pain sensation by selective activation of nociceptors. LEPs were maximal over the inferior aspect of the central sulcus and had the same polarity on either side of the sylvian fissure. AEPs were maximal posterior to the LEP maximum and had opposite polarity on opposite sides of the sylvian fissure, consistent with the location of a known generator in the temporal operculum. Auditory P3 (event-related) potentials were maximal over the temporal base. These findings demonstrate that the LEP generator is not in secondary somatosensory cortex on the parietal operculum and is different from the P3 generator.

Adult↗

PubMed2000

Structured implicit review: a new method for monitoring nursing care quality.

BACKGROUND: Nurses' independent decisions about assessment, treatment, and nursing interventions for hospitalized patients are important determinants of quality of care. Physician peer implicit review of medical records has been central to Medicare quality management and is considered the gold standard for reviewing physician care, but peer implicit review of nursing processes of care has not received similar attention. OBJECTIVE: The objective of this study was to develop and evaluate nurse structured implicit review (SIR) methods. RESEARCH DESIGN: We developed SIR instruments for rating the quality of inpatient nursing care for congestive heart failure (CHF) and cerebrovascular accident (CVA). Nurse reviewers used the SIR form to rate a nationally representative sample of randomly selected medical records for each disease from 297 acute care hospitals in 5 states (collected by the RAND-HCFA Prospective Payment System study). SUBJECTS: The study subjects were elderly Medicare inpatients with CHF (n = 291) or CVA (n = 283). MEASURES: We developed and tested scales reflecting domains of nursing process, evaluated interrater and interitem reliability, and assessed the extent to which items and scales predicted overall ratings of the quality of nursing care. RESULTS: Interrater reliability for 14 of 16 scales (CHF) or 10 of 16 scales (CVA) was > or = 0.40. Interitem reliability was > 0.80 for all but 1 scale (both diseases). Functional Assessment, Physical Assessment, and Medication Tracking ratings were the strongest predictors of overall nursing quality ratings (P < 0.001 for each). CONCLUSIONS: Nurse peer review with SIR has adequate interrater and excellent scale reliabilities and can be a valuable tool for assessing nurse performance.

Aged↗

PubMed1999

Veno-occlusive disease of the liver after busulfan, melphalan, and thiotepa conditioning therapy: incidence, risk factors, and outcome.

The purpose of this study was to determine the incidence of veno-occlusive disease (VOD) after a high-dose regimen of busulfan, melphalan, and thiotepa and the risk factors for a more severe outcome. We followed 253 consecutive patients with malignant disorders who received autologous transplants after stem cell harvest followed by 12 mg/kg busulfan, 100 mg/m2 melphalan, and 500 mg/m2 thiotepa. Diagnosis of VOD was based on weight gain, hepatomegaly, and jaundice. Risk factors for moderate or severe VOD were identified using logistic regression models. VOD occurred in 70 of 253 patients (28%), of whom 31 (12%) had moderate and 11 (4%) severe VOD. The median day of onset of hyperbilirubinemia was day 9, significantly later than the onset of jaundice after our cyclophosphamide-based regimens (p < 0.001). Resolution of weight gain and jaundice, followed by their reappearance several weeks later, occurred in 23 of 70 patients with VOD and was an adverse prognostic sign. Risk factors for moderate or severe VOD were a diagnosis of lymphoma or myeloma (odds ratio [OR] 2.65 compared with breast cancer), tumor involvement in the liver (OR 3.95), fever in the month before transplant (OR 3.32), and prior radiation therapy (OR 2.70). We conclude that VOD after busulfan, melphalan, and thiotepa was less frequent and less severe and developed later than VOD after our historical cyclophosphamide-based regimens. Significant risk factors included a diagnosis other than breast cancer, hepatic metastases, persistent fever, and prior radiation therapy. This study suggests that alkylating agents of comparable overall toxicity differ in their liver toxicity.

Adolescent↗

PubMed1999

Molecular analysis of HLA-DR gene expression induced by IFN-gamma in malignant melanoma cell lines.

Human leukocyte antigen (HLA) class II molecules are polymorphic cell surface glycoproteins that are crucial for the cellular interaction in immune response. The expression of class II molecules is regulated in a tissue-specific and cytokine-inducible manner, and is mainly restricted to the antigen presenting cells. However, some tumor cells also express class II molecules, and in some class-II-negative tumor cells, class II expression is inducible by interferon (IFN)-gamma. However, their expression varies, even though the tumor cells originate from the same histological origin; some tumor cells show strong expression, others show weak or no expression. To determine whether this differential expression of class II molecules on tumor cells is transcriptionally regulated, FACS analysis and Northern hybridization were performed using a panel of melanoma cell lines, IGR3, Malme-3M, SK-Mel-24, and SK-Mel-28 to analyze the cell surface expression and mRNA transcription rate of HLA-DR before and after treatment with IFN-gamma. FACS analysis showed that before IFN-gamma treatment, IGR3 and Malme-3M cells barely expressed HLA-DR. On the contrary, almost all of the SK-Mel-24 cells (> 90%) and a relatively high rate (> 50%) of SK-Mel-28 cells expressed HLA-DR. After IFN-gamma treatment, HLA-DR expression was induced in Malme-3M cells and SK-Mel-28 cells which displayed elevated levels of HLA-DR expression in a time-dependent manner. However, IGR3 cells never responded to IFN-gamma. Northern analysis showed that treatment with IFN-gamma led to the steady-state mRNA augmentation of the HLA-DR gene in Malme-3M and SK-Mel-28, whereas in IGR3, IFN-gamma did not augment the transcriptional rate of the HLA-DR gene. To further clarify this differential modulation, sequencing analysis of PCR product of the HLA-DR proximal promoter region was done, since the transcription rate of the class II gene is controlled by the well-conserved proximal promoter region. Six independent clones from PCR products of the HLA-DRA proximal promoter region and 16 clones from PCR products of the HLA-DRB proximal promoter region were isolated from the above cell lines and sequenced. Comparison of the nucleotide sequences of all 6 clones of DRA promoter showed that the sequences are extremely similar in both regulatory sequences and their intervening sequences. Sixteen clones of HLA-DRB promoter showed sequence variations such as substitution and insertion/deletion, and these 16 clones could be further grouped into 6 homologues with sequence homology. These data established that the melanoma cell lines studied here showed a differential susceptibility to IFN-gamma on the modulation of HLA-DR molecules, that this modulation is transcriptionally regulated, and that the difference in promoter activity by sequence variation might contribute to such a differential transcriptional regulation at the promoter level.

Base Sequence↗

PubMed1999

Does what nurses do affect clinical outcomes for hospitalized patients? A review of the literature.

OBJECTIVE: Through a review of the literature, to identify and describe (1) empirical studies of inpatient nursing care quality that evaluate links between nursing care processes and health-related patient outcomes, (2) nursing care processes for which process-outcome links have been established, and (3) important nursing care processes that have not yet been evaluated. DATA SOURCES/STUDY SETTING: Published empirical studies of inpatient nursing care quality that evaluated links between processes of nursing care and health-related patient outcomes. STUDY DESIGN/DATA COLLECTION/EXTRACTION METHODS: This literature review used a five-step article search and review method. PRINCIPAL FINDINGS: Of 257 data-based studies of nursing care quality identified, 135 investigated a process-outcome link but only 17 met study inclusion criteria. The literature provides evidence that the quality of nursing care processes affects health-related patient outcomes during and after hospitalization. Gaps in the literature that evaluates nursing quality are identified. CONCLUSIONS: Although some nursing care processes affect health-related patient outcomes, the full extent of nursing process-outcome links is relatively understudied. Further evaluation of the interrelationships between nursing care processes and outcomes is critical.

Humans↗

PubMed1998

Purification and characterization of the tyrosinase isozymes of pine needles.

Three tyrosinase isozymes were purified to electrophoretic homogeneity from pine needles. The molecular weight of the three isozymes (P1, P2 and P3) were approximately 65,000, 50,000 and 45,000, and the pI values were 6.2, 5.9 and 5.3, respectively. The three isozymes have a number of common properties. These include amino acid composition, substrate specificity, response to inhibition. The amino acid compositions of the three isozymes showed the characteristic high contents of glycine, serine and glutamic acid residues. The three isozymes exhibited high substrate specificity towards pyrogallol. The K(m) values of the three isozymes for L-DOPA ranged from 8.7 to 10 mM. L-ascorbic acid and beta -mercaptoethanol, glutathione and sodium diethyldithiocarbamate notably inhibited the enzymatic activities.

Amino Acids↗

PubMed1997

The pentanucleotide ATTGG, the "inverted CCAAT," is an essential element for HLA class I gene transcription.

The HLA class I genes, HLA-A, -B, and -C, contain an inverted CCAAT sequence (ATTGG) located 20 bp upstream of the canonical CCAAT and approximately 70 bp upstream of the transcription initiation site. We have investigated the transcriptional function of the class I inverted CCAAT sequence using the HLA-normal cell line, HeLa. Deletion, mutation, or inversion of the inverted CCAAT sequence abrogated or reduced the activity of the class I promoter, as assessed by luciferase reporter gene assays in transient gene expression experiments. This activity coincided with occupancy of the inverted CCAAT motif, as tested by electrophoretic mobility shift assays using the wild-type sequence and mutated variants of the sequence. The ATTGG-binding protein was not CP2, NF-1, or other known CCAAT-binding proteins, but the complex may contain a CP1/NF-Y-like protein. Our results indicate that this inverted CCAAT sequence is an essential element for the expression of HLA class I genes and that its transcriptional activity depends upon the sequence, position, and orientation of the pentanucleotide.

Base Sequence↗

PubMed1997

Treatment of hepatic venocclusive disease with recombinant human tissue plasminogen activator and heparin in 42 marrow transplant patients.

The purpose of this report is to review the Fred Hutchinson Cancer Research Center experience of treating patients with venocclusive disease of the liver (VOD) after marrow transplantation using recombinant human tissue plasminogen activator (rh-tPA) and heparin. The charts of 42 patients who had received rh-tPA and heparin for the treatment of VOD between February 1991 and December 1995 were reviewed. Response to rh-tPA and heparin was defined as a reduction in total serum bilirubin by 50% within 10 days of starting treatment. Total serum bilirubin, percent weight gain, and serum creatinine before, after, and at the start of rh-tPA and heparin were examined to determine whether these laboratory values distinguished patients who responded to treatment from those who did not. We also evaluated whether evidence of multiorgan failure (requirement for supplemental oxygen, requirement for hemodialysis, requirement for mechanical ventilation) or whether the calculated probability of a fatal outcome from VOD could discriminate responders from nonresponders. In addition, the incidence and outcome of bleeding as a major complication of thrombolytic therapy was examined. Twelve patients responded to rh-tPA and heparin and 30 patients did not. There were no statistically significant differences between responders and nonresponders in the day treatment was started, dose of rh-tPA, total serum billirubin, and percent weight gain before, after, or at the start of treatment, or the calculated probability of dying from VOD on the day treatment with rh-tPA and heparin was begun. More nonresponding patients required dialysis or mechanical ventilation (11 of 30) before or at the start of rh-tPA and heparin than responding patients (0 of 12), P = .0183. Serum creatinine was greater at the start of treatment in nonresponding patients (1.9 +/- 1.3 mg/dL) than in responding patients (1.1 +/- 0.4 mg/dL), P = .0794. Ten patients had severe bleeding episodes, which resulted in death in three patients and may have contributed to death in an additional three patients. Treatment for VOD using rh-tPA and heparin was successful in 29% of patients but was associated with a significant risk of life-threatening hemorrhage. Requirement for supplemental oxygen, dialysis, or mechanical ventilation before the start of treatment were prognostic indicators of no response to thrombolytic therapy. We do not recommend treatment using tPA and heparin in patients with severe VOD who have already developed multiorgan dysfunction.

Adolescent↗

PubMed1997

Induction of ICAM-1, HLA-DR molecules by IFN-gamma and oncogene expression in human bladder cancer cell lines.

It is well known that the expression level of the ICAM-1 and MHC is frequently altered in accordance with tumor progression, and the expression of oncogenes is significantly related to tumorigenesis, tumor progression, and/or metastatic potential. In this study, to investigate the relationship between the alteration in ICAM-1 and MHC expression with the tumor grade and/or cell differentiation, we examined the expression of ICAM-1 and HLA-DR before and after treatment with IFN-gamma in 4 human bladder cancer cell lines. We also analyzed the expression of c-Ha-ras and c-myc. Using flow cytometry, highly constitutive expression of ICAM-1 was detected in all cell lines tested except RT4 (grade I, well-differentiated, superficial). IFN-gamma was found to somewhat induce the expression of ICAM-1 in all cell lines except RT4. The constitutive expression of HLA-DR was not detected in any of the cell lines tested by flow cytometry and Northern blot. HLA-DR expression was induced by IFN-gamma in RT4 and J82 (grade III, anaplastic, invasive). Codon 12 point mutation of c-Ha-ras (GGC-->GTC; Gly-->Val) was detected in T24 (grade III, epidermoid, superficial) through single-strand conformation polymorphism, and sequencing analysis. Another point mutation at codon 27 was detected in TCCSUP (grade IV, distant metastatic), but this mutation was found to be silent (CAT-->CAC; His). Expression of c-myc was detected in J82 and TCCSUP by Northern blot. These findings, along with the clinical and pathological characteristics of the patients from whom the cell lines were established, might suggest that the expression of ICAM-1 seems to be associated with cell differentiation, and the inducibility of HLA-DR by IFN-gamma seems to be associated with the degree of malignancy. Expression of c-myc seems to be associated with invasiveness. However, a significant correlation between c-Ha-ras activation and tumor grade could not be observed.

Animals↗

PubMed1997

Utilization of Chinese medicine in Taiwan.

This article examines the use of Chinese medicine in Taiwan. Based on a national sample survey, the authors investigated how Chinese medicine is being used and factors that are associated with its use among the Taiwanese. Results of the study suggest that Chinese medicine use among this population depends on health conditions, and that having a regular source of care for Chinese medicine as well as a preference for Chinese medicine are two predictors for its use. Policies on the integration of Chinese medicine or other traditional medicine into the modern healthcare system are recommended.

Adolescent↗

PubMed1996

The practice of Chinese medicine in Taiwan.

This paper examines the practice of Chinese medicine in Taiwan. Using a national sample survey of Chinese medicine physicians, supplemented by another national survey of Chinese medicine hospitals and government records, the authors study the education and training background of Chinese medicine physicians, their mode of practice, their productivity measured by patient visits, and the practice characteristics of Chinese medicine hospitals. Moreover, the authors investigate the relationship between the resource input, the public health insurance contract, and the number of patient visits Chinese medicine physicians provided. Results of this study are used to make several recommendations on the appropriate way of integrating the practice of Chinese medicine into the modern health care system. Many of these recommendations may also be applicable to other countries that are contemplating integrating traditional or alternative medicine into their health care systems.

Adult↗

PubMed1995

Hydration, not silicone, modulates the effects of keratinocytes on fibroblasts.

Topical silicone gel or silicone cream with occlusive dressing has proved to be an efficacious method for the treatment and prevention of hypertrophic scars and keloids, but how this action is triggered remains unknown. Hydration of the epidermis and/or the cellular effects of the released low-molecular-weight silicone oil have been suggested as possible mechanisms. In order to further elucidate the mechanism, we used an in vitro keratinocyte-fibroblast coculture model to investigate the cellular effects of silicone and hydration. In this model, the condition of clinical usage of topical silicone gel or cream or the condition of hydration exerted by occlusive dressing could be mimicked. The model consisted of two chambers separated by a semipermeable membrane, in which a fully differentiated stratified epithelium is present in the upper chamber and medium and monolayer fibroblasts are located in the lower chamber. The keratinocytes were nourished from the basal side only, while the apical surface was submerged in silicone oil, paraffin, Hanks' balanced salt solution, or medium (hydration); or it was exposed to air (control). In the hydration-treated group, the proliferation of fibroblasts measured as [3H]thymidine incorporation and their collagen, glycosaminoglycan production was significantly inhibited when compared with the controls, but exposure of the keratinocyters to silicone oil or paraffin did not influence fibroblast behavior. The results suggest that hydration, not silicone, modulates the in vitro keratinocyte-fibroblast interaction. This may be one possible mechanism by which topical silicone or occlusive dressing treatment may affect the development of hypertrophic scars and keloids.

Cell Division↗

PubMed1995

The role of lipid peroxidation in menadione-mediated toxicity in cardiomyocytes.

The role of lipid peroxidation in menadione-mediated toxicity was studied in neonatal rat cardiomyocytes. Incubation of cardiomyocytes with menadione resulted in depleted cellular glutathione levels, increased intracellular Ca2+ and increased lipid peroxidation which all occurred prior to cell degeneration. Pre-treatment of cells with cysteine suppressed the menadione-induced cell degeneration and prevented changes in glutathione levels, intracellular Ca2+, and lipid peroxidation. Pre-treatment of cells with fura-2 acetoxymethyl ester, a Ca2+ chelator, reduced menadione-induced cell degeneration and lipid peroxidation but it did not block cellular glutathione depletion. Pre-treatment of cells with deferoxamine mesylate, an iron chelator, also reduced both menadione-induced cell degeneration and lipid peroxidation; however, it did not prevent the menadione-induced increase in intracellular Ca2+, nor the depletion of glutathione. Thus, the inhibition of menadione-induced lipid peroxidation by deferoxamine mesylate prevented cell degeneration even though intracellular Ca2+ remained elevated and glutathione remained depleted. The protective effects of deferoxamine mesylate and fura-2 AM on menadione's toxicity were inhibited by addition of FeCl3 to cells. Ferric ions did not inhibit the protective effect of cysteine. These data suggest that menadione-induced cardiomyocyte degeneration is directly linked to iron-dependent lipid peroxidation and less tightly coupled to elevation in intracellular Ca2+ or depletion of glutathione.

Animals↗

PubMed1995

Collaboration: a concept analysis.

Collaboration is a complex phenomenon, yet one that is of significance to nursing. This concept analysis presents definitions and defining characteristics of collaboration so that the concept may be used in the creation of operational definitions, or to develop and evaluate tools for measuring collaboration. Antecedents, consequences and empirical referents of collaboration are explored. Model, contrary and related cases are presented to clarify this concept further.

Communication↗

PubMed1995

Induction of ICAM-1 and HLA-DR expression by IFN-gamma in malignant melanoma cell lines.

Two human malignant melanoma cell lines, Malme-3M and SK-Mel-28, were analyzed for their ability to induce the expression of intercellular adhesion molecule 1 (ICAM-1) and human leukocyte antigen (HLA)-DR molecules on their cell surfaces as well as at the transcriptional level before and after treatment with interferon (IFN)-gamma. Both cell lines demonstrated a high percentage (> 99%) of ICAM-1 expression regardless of IFN-gamma treatment. Before IFN-gamma treatment, Malme-3M cells barely expressed HLA-DR molecules (< 2%) and SK-Mel-28 cells demonstrated a relatively high percentage (> 50%) of HLA-DR expression. Both cell lines displayed elevated levels of HLA-DR expression in a time dependent manner after IFN-gamma treatment. However, these two cell lines have been shown to respond differentially to IFN-gamma. The molecular mechanism underlying such a differential behavior was investigated, and HLA-DR gene regulation was studied at the transcriptional level. Treatment with IFN-gamma led to the steady-state mRNA augmentation of the HLR-DR gene. The HLA-DRA mRNA augmentation was similar in both cell lines, whereas in Malme-3M, IFN-gamma did not augment the rate of transcription of the HLA-DRB gene as much as in SK-Mel-28. Data from this study established the fact that the melanoma cell lines displayed a differential susceptibility to IFN-gamma on the modulation of HLA-DR molecules, and this modulation was transcriptionally regulated.

Genes, MHC Class II↗

PubMed1995

Does compression of the base of the penis improve the efficacy of intracavernosal injection of prostaglandin E1 for impotence? A randomized controlled study.

The objective of this study was to evaluate the effect on erections of impeding venous blood flow following intracavernosal injections of prostaglandin E1. Dispersion of injected X-ray contrast medium indicated that application of the RMRI penile clamp to the base of the penis retarded venous outflow. The clamp was then tested in impotent men to determine whether their erectile response was enhanced. Erectile response was assessed using a Rigiscan monitor, palpation of the penis by a staff nurse and the patient's subjective impression. The results demonstrate that there is no significant improvement in erectile response following venous compression.

Adult↗