Biomedical subjects

H Moon

Publications and source records attributed to H Moon.

At least 19 recordsLinked to original sources

PubMed2007

Transport of living cells with magnetically assembled nanowires.

We present a technique of transporting and positioning living cells internalized by nickel (Ni) nanowires guided by magnetic field. Nanoscale magnetic nanowires are internalized by the Rat Neuroblastoma (ATCC number CRL-2754) and the cells are transported and positioned by magnetic fields from the magnetic material-coated electrodes. This technique may enable the interfacing between neurons and electronic devices to empower investigations pertaining to non-invasive neuron probing as well as nanofabricated neural pharmacological technologies.

Animals↗

PubMed2006

Decision threshold adjustment in class prediction.

Standard classification algorithms are generally designed to maximize the number of correct predictions (concordance). The criterion of maximizing the concordance may not be appropriate in certain applications. In practice, some applications may emphasize high sensitivity (e.g., clinical diagnostic tests) and others may emphasize high specificity (e.g., epidemiology screening studies). This paper considers effects of the decision threshold on sensitivity, specificity, and concordance for four classification methods: logistic regression, classification tree, Fisher's linear discriminant analysis, and a weighted k-nearest neighbor. We investigated the use of decision threshold adjustment to improve performance of either sensitivity or specificity of a classifier under specific conditions. We conducted a Monte Carlo simulation showing that as the decision threshold increases, the sensitivity decreases and the specificity increases; but, the concordance values in an interval around the maximum concordance are similar. For specified sensitivity and specificity levels, an optimal decision threshold might be determined in an interval around the maximum concordance that meets the specified requirement. Three example data sets were analyzed for illustrations.

Algorithms↗

PubMed2003

Independent exponential feeding of glycerol and methanol for fed-batch culture of recombinant Hansenula polymorpha DL-1.

As a novel feeding strategy for optimizing human epidermal growth factor (hEGF) production with a recombinant Hansenula polymorpha DL-1 using the methanol oxidase (MOX) promoter in H. polymorpha DL-1, independent exponential feeding of two substrates was used. A simple kinetic model considering the cell growth on two substrates was established and used to calculate the respective feeding rates of glycerol and methanol. In the fedbatch culture with methanol-only feeding, the optimal set point of specific growth rate on methanol was found to be 0.10 h-1. When the fed-batch cultures were conducted by the independent feeding of glycerol and methanol, the actual specific growth rate on glycerol and methanol was slightly lower than the set point of specific growth rate. By the uncoupled feeding of glycerol and methanol the volumetric productivity of hEGF increased from 6.4 to 8.0 mg/(L.h), compared with methanol-only feeding.

Alcohol Oxidoreductases↗

PubMed2003

Granular activated carbon (GAC) adsorption in tertiary wastewater treatment: experiments and models.

Wastewater treatment has always been a major concern in the developed countries. Over the last few decades, activated carbon adsorption has gained importance as an alternative tertiary wastewater treatment and purification process. In this study, granular activated carbon (GAC) adsorption was evaluated in terms of total organic carbon (TOC) removal from low strength synthetic wastewater. This paper provides details on adsorption experiments conducted on synthetic wastewater to develop suitable adsorption isotherms. Although the inorganics used in the synthetic wastewater solution had an overall unfavourable effect on adsorption of organics, the GAC adsorption system was found to be effective in removing TOC from the wastewater. This study showed that equation of state (EOS) theory was able to fit the adsorption isotherm results more precisely than the most commonly used Freundlich isotherm. Biodegradation of the organics with time was the most crucial and important aspect of the system and it was taken into account in determining the isotherm parameters. Initial organic concentration of the wastewater was the determining factor of the model parameters, and hence the isotherm parameters were determined covering a wide range of initial organic concentrations of the wastewater. As such, the isotherm parameters derived using the EOS theory could predict the batch adsorption and fixed bed adsorption results of the multi-component system successfully. The isotherm parameters showed a significant effect on the determination of the mass transfer coefficients in batch and fixed bed systems.

Adsorption↗

PubMed2001

Ten-year survival of patients with locally advanced, stage ib-iib cervical cancer after neoadjuvant chemotherapy and radical hysterectomy.

OBJECTIVE(S): The aim of this study was to evaluate the effects of neoadjuvant chemotherapy and radical hysterectomy on long-term survival in stage IB-IIB locally advanced cervical cancer by conducting a 10-year follow-up. METHODS: Between August 1983 and May 1990, 80 locally advanced, stage IB-IIB cervical cancer patients with tumor diameter greater than or equal to 4 cm were treated with neoadjuvant VBP chemotherapy (cisplatin, vinblastine, and bleomycin) followed by radical hysterectomy with pelvic lymphadenectomy. After this therapeutic modality, patients were followed for more than 10 years. Ten-year survival rates and factors affecting recurrence after this therapy were evaluated. RESULTS: Of 80 patients, 75 (93.7%) showed a reduction in tumor size after neoadjuvant chemotherapy. At pathologic examination, stage reduction was noted in 53 (66.2%) patients and 20 patients (25%) showed no residual or microinvasive cervical tumor. Pelvic lymph node metastases were found in 17 patients (21.3%). During the 10-year follow up, 2 patients were lost and 16 patients recurred. Overall 5-year and 10-year disease-free actual survival rates were 82.0 (64/78) and 79.4% (62/78), respectively. Clinical stage, initial tumor size, clinical response, and residual tumor size were not risk factors for recurrence after this therapy. However, pelvic lymph node metastasis was a significant risk factor for recurrence. CONCLUSION(S): Neoadjuvant VBP chemotherapy followed by radical hysterectomy in locally advanced, stage IB-IIB cervical cancer patients seemed to improve the long-term survival rate for these patients compared to that of conventional therapy. However, randomized controlled trials are needed to confirm this result.

Adenocarcinoma↗

PubMed2001

Looking forward and looking back: integrating completion and sunk-cost effects within an escalation-of-commitment progress decision.

Currently, there are 2 conflicting frameworks with which to understand why decision makers might escalate their commitment to a previously chosen course of action: sunk costs and project completion. The author proposes that sunk costs and need to complete exert simultaneous pressures, both independent and interactive, on a decision maker's level of commitment. The responses of 340 participants were analyzed and supported a complementary relationship between the 2 predictors. In addition, sunk costs demonstrated a curvilinear influence on commitment and an interaction with level of completion that supported a Level of Completion x Sunk Cost moderation model. (A marginal utility model was not supported.) Results are discussed in terms of their relevance toward offering a complementary view of 2 potential antecedents to a decision maker's propensity to escalate his or her commitment to a previously chosen course of action.

Choice Behavior↗

PubMed2001

The two faces of conscientiousness: duty and achievement striving in escalation of commitment dilemmas.

The author proposes that 2 facets of conscientiousness, duty and achievement striving, affect decision makers in escalation of commitment dilemmas in opposing ways, thus masking the predictive ability of a broad measure of conscientiousness. It is proposed that duty is associated with an other-centered orientation and that achievement striving is associated with a self-centered orientation. Analyses of decisions from 360 respondents showed that duty was associated with a deescalation of commitment, achievement striving was associated with an escalation of commitment, and the broad measure of conscientiousness was unassociated with commitment. The author advocates the utility of understanding potential self-centered versus other-centered aspects of the criterion of interest when conducting personality-based research.

Adult↗

PubMed2001

Computational and performance aspects of PCA-based face-recognition algorithms.

Algorithms based on principal component analysis (PCA) form the basis of numerous studies in the psychological and algorithmic face-recognition literature. PCA is a statistical technique and its incorporation into a face-recognition algorithm requires numerous design decisions. We explicitly state the design decisions by introducing a generic modular PCA-algorithm. This allows us to investigate these decisions, including those not documented in the literature. We experimented with different implementations of each module, and evaluated the different implementations using the September 1996 FERET evaluation protocol (the de facto standard for evaluating face-recognition algorithms). We experimented with (i) changing the illumination normalization procedure; (ii) studying effects on algorithm performance of compressing images with JPEG and wavelet compression algorithms; (iii) varying the number of eigenvectors in the representation; and (iv) changing the similarity measure in the classification process. We performed two experiments. In the first experiment, we obtained performance results on the standard September 1996 FERET large-gallery image sets. In the second experiment, we examined the variability in algorithm performance on different sets of facial images. The study was performed on 100 randomly generated image sets (galleries) of the same size. Our two most significant results are (i) changing the similarity measure produced the greatest change in performance, and (ii) that difference in performance of +/- 10% is needed to distinguish between algorithms.

Algorithms↗

PubMed2001

A condensing enzyme from the seeds of Lesquerella fendleri that specifically elongates hydroxy fatty acids.

Lesquerella fendleri seed oil contains up to 60% hydroxy fatty acids, nearly all of which is the 20-carbon hydroxy fatty acid lesquerolic acid (D-14-hydroxyeicos-cis-11-enoic acid). Previous work suggested that lesquerolic acid in L. fendleri was formed by the elongation of the 18-carbon hydroxy fatty acid, ricinoleic acid. To identify a gene encoding the enzyme involved in hydroxy fatty acid elongation, an L. fendleri genomic DNA library was screened using the coding region of the Arabidopsis Fatty Acid Elongation1 gene as a probe. A gene, LfKCS3, with a high sequence similarity to known very long-chain fatty acid condensing enzymes, was isolated. LfKCS3 has a 2,062-bp open reading frame interrupted by two introns, which encodes a polypeptide of 496 amino acids. LfKCS3 transcripts accumulated only in the embryos of L. fendleri and first appeared in the early stages of development. Fusion of the LfKCS3 promoter to the uidA reporter gene and expression in transgenic Arabidopsis resulted in a high level of beta-glucuronidase activity exclusively in developing embryos. Seeds of Arabidopsis plants transformed with LfKCS3 showed no change in their very long-chain fatty acid content. However, when these Arabidopsis plants were crossed with the transgenic plants expressing the castor oleate 12-hydroxylase, significant amounts of 20-carbon hydroxy fatty acids accumulated in the seed, indicating that the LfKCS3 condensing enzyme specifically catalyzes elongation of 18-carbon hydroxy fatty acids.

Acetyltransferases↗

PubMed2000

Changes in fatty acid composition in plant tissues expressing a mammalian delta9 desaturase.

Plant tissues expressing a mammalian stearoyl-CoA delta9 desaturase were reported to accumulate delta9 hexadecenoic acid (16:1), normally very minor in most plant tissues. The transgenic plants were thoroughly analyzed for alterations of individual lipids in different subcellular sites. Western blot analysis indicated that the animal desaturase was targeted to the microsomes. The delta9 16:1 was incorporated into both the sn-1 and sn-2 positions of all the major membrane lipids tested, indicating that the endoplasmic reticulum acyltransferases do not exclude unsaturated C16 fatty acids from the sn-2 position. In addition to increases in monounsaturated and decreases in saturated fatty acids, accumulation of 16:1 was accompanied by a reduction in 18:3 in all the lipids tested except phosphatidylglycerol, and increases in 18:2 in phospholipids. Total C16 fatty acid content in the galactolipids of the transgenics was significantly higher than that in the control, but those in the phospholipids were unchanged. In transgenics, delta11 18:1 was detected in the sn-1 position of the lipids tested except phosphatidylinositol and phosphatidylserine. Introduction of the animal desaturase, controlled by a seed-specific phaseolin promoter, into soybean somatic embryo resulted in a significant reduction in saturated fatty acids. Such effects were greater in cotyledons than hypocotyl-radicles. This study demonstrated that the animal desaturase can be used to decrease the levels of saturated fatty acids in a crop plant.

Animals↗

PubMed2000

Prediction of the clinical course of Behçet's colitis according to macroscopic classification by colonoscopy.

BACKGROUND AND STUDY AIMS: The lesions in Behçet's colitis show aphthoid or punched-out ulceration, but the macroscopic types of lesion found have not been defined. To predict the clinical outcome in patients with Behçet's colitis according to the colonoscopic findings, we classified the characteristic colonic ulcers, evaluated the efficacy of medical treatment on colonoscopic lesions, and calculated the operation rates and recurrence rates relative to the macroscopic types. PATIENTS AND METHODS: The medical records and colonoscopic photographs of 50 patients with Behçet's colitis were reviewed. The colonic lesions were examined by colonoscopy in patients with Behçet's disease and gastrointestinal symptoms. The colonoscopic findings were categorized into three types of ulceration: volcano-like, geographic, and aphthous. The efficacy of medical treatment was assessed by follow-up colonoscopy or double-contrast barium enema four to eight weeks after treatment, and recurrence of the lesions was evaluated during the follow-up periods. Cumulative surgery rates were obtained using the Kaplan-Meier method. RESULTS: The macroscopic classification of colonic ulcers identified 25 of 50 patients (50%) with volcano-type lesions, 11 (22%) with the geographic type, and 14 (28%) with the aphthous type. The rates of complete remission after medical treatment and surgery, respectively, were six of 25 (24%) and 13 of 25 (52%) with volcano-type ulcerations; eight of 11 (73%) and one of 11 (9%) with the geographic type; and nine of 14 (64%) and two of 14 (14%) with the aphthous type. The endoscopic and clinical recurrence rates were nine of 19 (47%) in volcano-type ulcerations, one of nine (11%) in the geographic type, and one of 11 (9%) in the aphthous type. CONCLUSION: Volcano-type ulcerations in Behçet's colitis showed a less favorable response to medical treatment, a more frequent requirement for surgery, and more frequent recurrences than the geographic and aphthous types of ulcerations.

Adult↗

PubMed2000

Primary peritoneal pregnancy implanted on the uterosacral ligament: a case report.

Peritoneal pregnancies are classified as primary and secondary. Primary implantation on the peritoneum is extremely rare in extrauterine pregnancy and is a potentially life-threatening variation of ectopic pregnancy within the peritoneal cavity, representing a grave risk to maternal health. Secondary abdominal pregnancies are by far the most common and result from tubal abortion or rupture, or less often, after uterine rupture with subsequent implantation within abdomen. Early diagnosis and appropriate surgical management, regardless of stage of gestation, appear to be important in achieving good results. We report a case of primary peritoneal pregnancy in a 28-year-old woman, who had severe lower abdominal pain one day before laparotomy for a preoperative diagnosis of ectopic pregnancy. The conceptus was implanted on the left uterosacral ligament. A fresh embryo of approximately 8 weeks' gestation was found in the conceptus.

Adult↗

PubMed2000

Production of hydroxy fatty acids in the seeds of Arabidopsis thaliana.

Seed-specific expression in Arabidopsis thaliana of oleate hydroxylase enzymes from castor bean and Lesquerella fendleri resulted in the accumulation of hydroxy fatty acids in the seed oil. By using various Arabidopsis mutant lines it was shown that the endoplasmic reticulum (ER) n-3 desaturase (FAD3) and the FAE1 condensing enzyme are involved in the synthesis of polyunsaturated and very-long-chain hydroxy fatty acids, respectively. In Arabidopsis plants with an active ER Delta12-oleate desaturase the presence of hydroxy fatty acids corresponded to an increase in the levels of 18:1 and a decrease in 18:2 levels. Expression in yeast indicates that the castor hydroxylase also has a low level of desaturase activity.

Arabidopsis↗

PubMed1999

Effects of ethanol and its metabolite acetaldehyde on responses of the rat bladder.

OBJECTIVE: To investigate the pharmacological effects of ethanol and its metabolite acetaldehyde on isolated rat bladder muscle, and thus assess the potential influence of ethanol ingestion on the risk of urinary retention in patients with benign prostatic hyperplasia. MATERIALS AND METHODS: Isometric tension changes of isolated rat bladder muscle strips were recorded in an organ bath using a pressure transducer. The acute or prolonged effects of ethanol (1-4%) or acetaldehyde (0.01, 0.1 or 1 mmol/L) were assessed on resting tension, electrical field stimulation (EFS), and bethanechol- (0.5 mmol/L), ATP- (2 mmol/L) or KCl- (127 mmol/L) induced contraction. To determine the mechanism of acetaldehyde-induced stimulation, an antihistamine, diphenhydramine was used after bethanechol stimulation. RESULTS: At the concentrations used, ethanol and acetaldehyde did not change the pH of the bathing medium. The resting tension of the muscle was not changed by ethanol, and acetaldehyde caused only a small increase in baseline tone at 1 mmol/L. Incubation with ethanol or acetaldehyde significantly suppressed contractility induced by EFS, bethanechol, ATP or KCl at each concentration (P<0.05). Contractions induced by all drugs were not changed significantly by the acute application of ethanol and the acute application of acetaldehyde did not affect contractions induced by ATP or KCl. However, EFS- or bethanechol-induced contractions were significantly enhanced (P<0. 05). The acetaldehyde-induced effects were completely blocked by the H1 antagonist, diphenhydramine (10 micromol/L). CONCLUSIONS: Ethanol did not affect resting tension but acetaldehyde and ethanol suppressed bladder muscle contractions. However, direct acetaldehyde-stimulation may release histamine and enhance contractility. This suggests that chronic alcoholism rather than acute intoxication is more likely to provoke urinary retention.

Acetaldehyde↗

PubMed1999

Morphological and biochemical analysis of anti-nuclear matrix protein antibodies in human sera.

Autoimmune sera have been used in the diagnosis of autoimmune diseases as well as the analysis of nuclear substructures. In an attempt to study the biological characteristics of the nuclear matrix, we screened human sera using immunofluorescent staining and immunoblot. We detected antibodies against nuclear matrix (NM), a remnant nonchromatin protein compartment after the treatment of detergent, salt and nuclease, in 212 out of 284 tested sera (74.6%) by immunoblot. Peptides with molecular weights of 70 kDa, 50 kDa and 25 kDa were detected in the order of frequency. Clinical informations of 198 out of 212 cases were available and went as follows: 38 cases were autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis; 132 non-autoimmune and non-neoplastic diseases; 16 neoplastic diseases and 12 cases unclassified. The immunofluorescent staining intensity by anti-nuclear matrix protein (NMP) antibodies decreased variably, but fibrillogranular, speckled and nucleolar immunolocalization patterns were retained after in situ fractionation. Ku70 and La protein were detected by anti-NMP antibodies. Immunolocalization by anti-NMP antibodies indicates that the NMPs constitute a variety of characteristic nuclear substructures and may serve as autoantigens in diverse human diseases. In addition, the presence of Ku70 and La protein as NMPs suggests that the NM can be functionally active in association with DNA or RNA.

Antigens, Nuclear↗

PubMed1999

Behenoyl cytarabine-associated reversible encephalopathy in a patient with acute myelogenous leukemia.

We report a case of reversible encephalopathy syndrome in a 16-year-old girl with acute myelogenous leukemia (AML), who is undergoing during consolidation chemotherapy composed of BH-AC (N4-behenoyl-1-beta-D-arabinofuranosyl cytosine) and idarubicin. On the 6th day of chemotherapy, she was in a drowsy state following generalized tonic clonic seizure lasting 20 minutes. MR images revealed extensive cortical and subcortical white matter brain edema. Alertness returned over the 24 hr following by the discontinuation of BH-AC and intravenous administration of diphenylhydantoin, although she complained of intermittent headaches and visual disturbance. She gradually recovered from these symptoms during subsequent 7 days. Previously noted abnormal signal intensities have nearly disappreared on follow-up MRI obtained on the 22nd day after the first seizure. She was discharged without any neurologic sequela. This case suggests that BH-AC, a derivative of cytosine arabinoside (1-beta-D-arabinofuranosylcytosine) could be a cause of reversible encephalopathy syndrome.

Adolescent↗

PubMed1998

Characteristic immunolocalization of Ku protein as nuclear matrix.

Two hybridoma clones, NMB1 and NML90, were established using nuclear matrix proteins from normal human thymi or malignant lymphoma as immunogens. They reacted with human Ku70 and Ku80, respectively, by immunoblotting. When HeLa cell nuclear proteins were fractionated and applied to immunoblotting, both Ku70 and Ku80 were detected in the nuclear matrix as well as the soluble nuclear protein fractions. By confocal scanning microscopy, the immunoreactivity of Ku70 and Ku80 was localized to distinct nucleoplasmic fibrillar network and fine granules in the interphase cell nuclei. When HeLa cells were fractionated in situ using DNase I and buffers containing 0.25 M (NH4)2SO4 and 2 M NaCl, the nucleoplasmic reticular structure was largely preserved, but granules disappeared. The nucleoplasmic distribution of Ku in the tissue and in cultured cells was distinct from each other. In the adult tissue, it consisted mostly of either distinct curvilinear lines along the nuclear periphery or of tangled, beaded lines throughout the nuclei. When xenotransplants of HeLa cell in Scid mice were examined, the "tissue type" immunolocalization pattern was reproduced consistently. In most fetal tissues, "tissue type" and "cell type" patterns were admixed. Monoclonal antibodies described here are useful tools for studying the structure and function of the nuclear matrix.

Animals↗

PubMed1998

Quality of life (QOL) assessment of MIP (mitomycin, ifosfamide and cisplatin) chemotherapy in advanced non-small cell lung cancers (NSCLC).

BACKGROUND: Quality of life (QOL) assessment has emerged to measure and quantify the balance between treatment benefit and toxicity, and has a value in predicting response and overall survival in cancer patients. METHODS: From July 1995 to February 1997, 38 symptomatic patients with advanced non-small cell lung cancer (NSCLC) were treated with MIP chemotherapy (mitomycin 6 mg/m2, ifosfamide 3000 mg/m2 and cisplatin 50 mg/m2 on day 1 every 3 weeks). Patients were assessed for QOL including physical well-being, general symptoms and lung cancer-specific symptoms, as well as objective response. RESULTS: The overall response rate was 38.9% (14/36, all were partial response) and the median duration of response was 3.5 months [95% confidence interval (CI) 2.0-4.0]. The median duration of overall survival was 7 months (95% CI 5.9-8.5). The overall improvement of QOL was 58.3% with 21 patients feeling better on treatment. The toxicity of chemotherapy was mild, mainly nausea/vomiting and minimal alopecia. Using multiple clinical predictors of survival (age, histology, stage, performance status), only change of QOL emerged significantly (P = 0.0007). CONCLUSIONS: MIP had an endurable response and low toxicity profile, and provided good QOL. Integral QOL data in our study provided the strong prediction of survival in advanced NSCLC. Further experienced QOL study will provide greatly enhanced outcome data in clinical trials.

Adult↗