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Biomedical subjects

S Lee

Publications and source records attributed to S Lee.

At least 91 records · Page 5Linked to original sources
PubMed2004

Post-prandial plasma ghrelin levels in people with different breakfast hours.

OBJECTIVES: To investigate the changes in post-meal plasma ghrelin levels in people with different breakfast hours. DESIGN AND INTERVENTIONS: The subjects adhered to strict breakfast times starting 2 weeks before the study. Blood was drawn hourly from 0530 or 0630 until 1130. Plasma ghrelin, leptin, and insulin levels were measured by radioimmunoassay. SETTING: Medical Research Institute, Pusan National University Hospital, Korea. SUBJECTS: A total of 16 healthy volunteers. RESULTS: The mean plasma ghrelin level in subjects consuming breakfast was 548.7 +/- 239.6 fmol/ml before breakfast and 384.8 +/- 168.7 fmol/ml 1 h after breakfast, with leptin levels of 6.8 +/- 2.6 and 6.5 +/- 2.5 ng/ml, respectively. Plasma ghrelin levels were lowest 1 h after the meal, although the breakfast times differed. The plasma ghrelin level was lowest at 0730 in subjects not eating breakfast. CONCLUSIONS: These findings suggest that the plasma ghrelin levels are lowest 1 h after breakfast despite the variance in breakfast times. This timing might best reflect an individual's plasma ghrelin level and enable reasonable comparisons.

Adult↗
PubMed2004

[A new therapy concept for the treatment of dry eye--the usefulness of phospholipid liposomes].

BACKGROUND: Most of the eye drops currently used replace only the aqueous phase of the tear film. But, due to the fact that, with approximately 80 % of the patients with a dry eye, a disturbance of the lipid phase is present, an approach for new treatment methods needed to be found. We examined a new therapy concept with an eye spray containing liposomes for the therapy of the "dry eye" in a long-term study. GOAL: An examination of the effectiveness of a liposome eye spray (TEARS AGAIN, Optima Pharmaceutical GmbH, Germany) in patients with "dry eye" compared with a spray containing a balanced salt solution was carried out. METHODS: Between August 2003 and May 2004 a double-blind study with 382 patients was accomplished. The treatment group (V; n = 191) was compared with the control group (K; n = 191) for a period of 6 months regarding the following examination criteria: eyelid edge parallel conjunctival folds (LIPCOF), BREAK UP time (BUT), Schirmer I test, best corrected visual acuity, as well as slit lamp findings of the cornea and conjunctiva. Follow-up was after 4 weeks and 6 months. The statistical analysis was performed with the statistical program SPSS v.11.5. RESULTS: The examined parameters such as LIPCOF, BUT and Schirmer were significantly better in the treatment group than in the control group. We found likewise significant improvements of the inflammations of the edge of eyelid with a remarkable decrease of around 89.5 %. Questioning of the patients resulted in, among other things, the belief that the liposome eye spray led altogether to a clear subjective improvement of the symptoms in 72 % of the cases, although an initial burning sensation was mentioned after the application. All patients were of the opinion that application with a spray is more favourably and more pleasant than teardrops. CONCLUSION: The liposome tear substitute shows statistically significant advantages against a balanced salt solution. This new liposome eye spray represents a new, revolutionary and effective procedure in the therapy of the "dry eye". Considering the disturbance of the lipid phase in 80 % of the patients, TEARS AGAIN ought to be a first choice treatment.

Adolescent↗
PubMed2004

Persistent HIV-1 replication does not explain low levels of T-cell interferon-gamma mRNA and elevated serum NO(2) (-)/NO(3) (-) in patients with stable CD4 T-cell responses to HAART.

HIV-1 infected patients adherent to HAART and displaying stable increases in CD4 T-cell counts differ in their control of HIV replication and one might expect this to reflect depressed immune function. The importance of virological control in functional immune reconstitution was investigated in HIV-1 infected patients who maintained high or undetectable plasma HIV RNA levels over 2-4 years on HAART (discordant and complete responders, respectively). Immunocompetence and immune activation were assessed directly ex vivo and after a short period of culture, as HIV replication in cultures from viraemic patients may artificially depress responses. Expression of cytokine (interferon-gamma, interleukin-5) and chemokine receptor (CCR5, CRTH2) mRNA were determined and soluble CD30 and NO(2) (-)/NO(3) (-) were measured in sera. Unstimulated cells from all patients had low levels of IFNgamma mRNA relative to uninfected controls. Discordant responders had more IFNgamma, IL-5 and CCR5 mRNA in mitogen-stimulated PBMC than complete responders, where the difference could be attributed to CD8-T-cells. Serum NO(2) (-)/NO(3) (-) levels were significantly higher in all patients than controls, with no difference between complete and discordant responders. Serum CD30 levels were significantly higher in discordant responders. These data indicate a persistent immune deficit in immune reconstituted patients irrespective of HIV viral load and associate persistent viral replication with lymphocyte activation, probably involving CD8 T-cells.

Adult↗
PubMed2004

Parastomal hernia repair.

OBJECTIVE: The aim of this study was to audit the results of parastomal hernia repair. METHODS: A retrospective review was made of all patients having parastomal hernia repair at 2 teaching hospitals over a 12-year period. RESULTS: Forty-three patients had 51 parastomal hernia repairs. Three types of hernia repair were used: 14 (28%) local suture, 19 (37%) local mesh repair and 18 (35%) stoma relocation. Three patients died and significant complications occurred in 65% of repairs. Parastomal hernia recurred in 18 (38%) of repairs. This was greatest with a sutured repair (59%) and least in patients having stoma relocation (24%). Repair with mesh was associated with a 39% recurrence rate. No significant statistical difference was found for the results of these repairs. CONCLUSION: Parastomal hernia repair is associated with high rates of morbidity, mortality and recurrence. Repair should not be undertaken without a good indication.

Adult↗
PubMed2004

Restoration of CD4 T-cell responses to cytomegalovirus is short-lived in severely immunodeficient HIV-infected patients responding to highly active antiretroviral therapy.

OBJECTIVES: To define the level of pathogen-specific immune reconstitution persisting over 3 to 5 years of highly active antiretroviral therapy (HAART) in HIV-infected patients who began therapy with CD4 T-cell counts below 50 cells/microL. METHODS: Cytomegalovirus (CMV)-specific T-cell responses were analysed in adult HIV-1-infected patients with nadir CD4 T-cell counts below 50 cells/microL before HAART. CMV-specific CD4 T-cell responses were measured by interferon-gamma enzyme-linked immunospot assay (ELISpot assay), lymphoproliferation and interferon-gamma levels in cell culture supernatants. RESULTS: CD4 T-cell responses to CMV were low in untreated patients and remained low during the first year on HAART, but increased progressively to levels similar to those found in HIV-seronegative CMV-seropositive controls at 3 years. Responses then declined markedly and at 5 years were lower than controls. This could not be explained by changes in CD4 or CD8 T-cell counts or plasma HIV RNA levels. Interferon-gamma and interleukin-5 responses to a mitogen were maintained or elevated. CONCLUSIONS: CMV-specific CD4 T-cell responses were found to decline after 3-5 years on HAART and may provide inadequate long-term protection against CMV disease in patients who are severely immunodeficient prior to treatment.

AIDS-Related Opportunistic Infections↗
PubMed2004

Aperture maneuver with compelled breath (AMC) for moving tumors: a feasibility study with a moving phantom.

Respiration causes target motion, which is known to be one of the technical bottlenecks in radiotherapy, especially for stereotactic radio-surgery and intensity modulated radiotherapy (IMRT). To overcome this problem, aperture maneuver with compelled breath (AMC) has been developed. In order to simulate compelled respiratory motion, a moving phantom using a ventilator was designed. As the air flow was forced to the bellows, which simulates the lungs, by a ventilator, a film connected to the ventilator moved like the respiratory target motion. A software was developed to transfer multileaf collimator motion from breathless to actual periodic breathing conditions. Static fields as well as step-and-shoot IMRT fields were modified in accordance with moving shapes to follow the target position, using the software with the controlled breathing information. Film dosimetry for a small field and for IMRT fields with a moving phantom was performed. To evaluate clinical implementation, five healthy volunteers were tested to breathe through a ventilator, and all of them could adapt the compelled breath without any difficulties. Additive margins for a moving target with AMC were not larger than 3 mm for respiratory organ motions up to 18 mm, while those with the static beam were 9 mm. For IMRT fields, large discrepancies were present between a static target and a moving target with the static beam, while they coincided well with AMC. Clinical acceptable differences between the dose distributions from a static target with the static beam and from a moving target with AMC revealed that this technique could be applied clinically.

Algorithms↗
PubMed2004

A feasibility study on the prediction of tumour location in the lung from skin motion.

The system for predicting tumour location from skin motion induced by respiration was designed to reduce the effects of target movement. Fluoroscopic studies on 34 sites in the lungs and 14 sites in the diaphragm were performed so that the motions of skin markers and organs could be observed simultaneously. While patients were lying down in the simulator with radio-opaque markers on their skin, fluoroscopic images both in the anterior-posterior (AP) view and in the lateral view were sent to an analysing computer and recorded. The results that showed a strong correlation (0.77+/-0.12) between the patients' skin and tumour movement, especially for the sites located in the lower lung fields or in the diaphragm. With the prediction from skin motion, the uncertainties of the position of tumours due to respiratory movement could be reduced by up to 1.47 cm in the lower lung fields in the superior-inferior (SI) direction. This study revealed that it is possible to trace the exact location of tumours in the lungs by observing skin motion in most cases (up to 88%).

Feasibility Studies↗
PubMed2004

Brown tumors developing in renal transplant recipients with persistent hyperparathyroidism: two case reports and review of literature.

BACKGROUND: Brown tumors, evidence for severe hyperparathyroidism, are rare in end-stage renal disease, and are distinctly uncommon in patients with a functioning renal transplant. CASE REPORTS: We report two cases of brown tumors developing after renal transplantation, and discuss their presentation and treatment. We review the literature. CONCLUSIONS: We suggest that persistent hyperparathyroidism post-renal transplant requires aggressive intervention to avoid significant consequences.

Bone Neoplasms↗
PubMed2004

Monitoring of COD as an organic indicator in waste water and treated effluent by fluorescence excitation-emission (FEEM) matrix characterization.

The fluorescence excitation-emission matrices (FEEM) of domestic waste water, treated effluent of a waste water treatment plant and receiving river water were analyzed to select wavelengths for the monitoring of organic contents as COD. Excitation/emission wavelengths of 220/350 nm and 270/350 nm for protein-like fluorescence and 240/450 nm and 340/450 nm for humic-like fluorescence were suggested as fluorescence peak emitting wavelength pairs, respectively. Without any pre-treatment, the protein-like fluorescence peaks showed better correlation between COD values and fluorescence intensities than the humic-like fluorescence peaks. No enhanced correlation was observed by removing the suspended solids from the samples using filtration. However, statistical multiple regression methods, using the fluorescence intensities from each peak and the light scattering intensity at 633 nm as variables, resulted in an enhanced correlation, with r2 > 0.9 for the measured and predicted COD values.

Environmental Monitoring↗
PubMed2004

Effect of residual ozone on membrane fouling reduction in ozone resisting microfiltration (MF) membrane system.

The effect of residual ozone on reducing the membrane fouling was investigated using ozone resisting microfiltration membrane. It was found out that the fouling was reduced effectively by maintaining residual ozone in the membrane module. To clarify the reason why the residual ozone reduces the membrane fouling, research was focused on the molecular degradation reaction and particle destabilization reaction induced by residual ozone. The major reason of membrane fouling reduction was attributed to the reduction of reversible resistance induced by the cake layer. The reversible resistance was reduced due to degradation of organic substances in the cake layer. In addition to degradation reaction, the increase of fouling particle size due to residual ozone in the cake layer is another important process for fouling reduction. This effect has been referred to as ozone-induced destabilization reaction. The calcium present in the raw water influenced this reaction. The increase of fouling particles size improves the filterability through the cake layer and backwashing efficiency.

Biodegradation, Environmental↗
PubMed2003

Evaluation of Kd underestimation using solid phase microextraction.

Many important environmental pollutants are strongly adsorbing hydrophobic compounds. Because of their potential to adsorb to dissolved organic matter (DOM), their partition coefficient Kd may be underestimated by the conventional approach due to incomplete phase separation. In this study, solid-phase microextraction (SPME) was compared with liquid-liquid partition (LLP) for measuring Kd of bifenthrin and permethrin isomers on sediments. Due to its selective detection of the freely dissolved concentration, SPME gave Kd values 0.6-4.4-fold greater than those obtained by LLP in creek and field sediments and 3.6-21.7-fold greater in nursery runoff sediments. Underestimation by the conventional method was attributed to adsorption to DOM that was not excluded from the aqueous phase by centrifugation. The degree of underestimation was dependent on the source and amount of DOM and may be generally significant for compounds that have DOM adsorption coefficient (KDOM) > 10(4). This study provides evidence that the existing Kd values for many hydrophobic pollutants may be underestimated, and SPME may be a viable, efficacious tool for evaluating the underestimation.

Adsorption↗
PubMed2003

An EST survey of the sugarcane transcriptome.

Its large genome and high polyploidy makes sugarcane (Saccharum spp.) a singularly challenging crop to study and improve using genetic approaches. To provide large numbers of functionally characterized candidate genes that might be tested for direct association (rather than distant linkage) with economically important traits, we sequenced the 5' ends of 9,216 clones from three cDNA libraries (apex, leaf and mature internode), representing 3,401 non-redundant sequences. About 57% of these sequences could be assigned a tentative function based on statistically significant similarity to previously characterized proteins or DNA sequences. Another 28% corresponded to previously identified, but uncharacterized, sequences. Some of the remaining unidentified sequences were predicted to be genes which could potentially be new to plants or unique to sugarcane. Comparisons of the sugarcane ESTs to a large sorghum EST database revealed similar compositions of expressed genes between some different tissues. Comparison to a detailed Arabidopsis protein database showed some highly conserved sequences, which might be useful DNA markers for pan-angiosperm comparative mapping. These EST sequences provide a foundation for many new studies to accelerate isolation of agronomically important genes from the cumbersome sugarcane genome.

Base Sequence↗