Analysis of the factors influencing living kidney donation: the experience in National Taiwan University Hospital

INTRODUCTION

Kidney transplantation provides a choice of active treatment for patients with chronic renal failure. However, the sources of organs are limited; therefore, living kidney donation is an alternative source. The regulation of organ donation in Taiwan stipulates that living organ donation is restricted to living related recipients. We sought to investigate factors that influenced or prevented individuals from living kidney donation in our center.

MATERIALS AND METHODS

From January 2005 to December 2008, there were 266 potential candidates who underwent evaluation for living kidney donation in our center.

RESULTS

Among the potential candidates, most were spouses (n=85, 31.9%), followed by parents (n=67, 25.1%), siblings (n=62, 23.3%), and children (n=40, 15%). Eventually, 124 candidates (47%) completed organ donation, most of whom were siblings (n=39, 31.5%), then parents (n=38, 30.6%), spouses (n=26), and children (n=18). Most donors were females, including mothers and sisters. The most frequent reason to not donate was unwillingness, due to potential influences on their health, economic stress due to suspension of their job, and objection of family members. In 34 candidates (23.9%), adverse health factors of potential candidates prohibited them from donating, including age, chronic medical illness, hepatitis carrier status, severe depression, or mental retardation. Among 59 potential donor-recipient pairs with incompatible ABO blood types or highly sensitized to potential donors, 22 candidates completed living kidney donation.

CONCLUSION

Although laparoscopic nephrectomy for living kidney donation decreases the discomfort and hospital stay after donation, we can only promote living kidney donation if we can deal with the possible factors that prohibit candidates from living kidney donation, such as morbidity after organ donation, anxiety, or other factors. After analyzing those factors, we must also develop a protocol to closely follow the living kidney donors to ensure their health status and relieve their anxiety.

Global target analysis of picosecond chlorophyll fluorescence kinetics from pea chloroplasts: A new approach to the characterization of the primary processes in photosystem II alpha- and beta-units

In this study, we have used the method of target analysis to analyze the ps fluorescence kinetics of pea chloroplasts with open (F(0)) and closed (F(max)) photosystem II (PS II) centers. Extending the exciton/radical pair equilibrium model (Schatz, G. H., H. Brock, and A. R. Holzwarth. 1988. Biophys. J. 54:397-405) to allow for PS II heterogeneity, we show that two types of PS II (labeled alpha and beta) must be accounted for, each pool being characterized by its own set of molecular rate constants within the model. Simultaneous global target analysis of the data at F(0) and F(max) results in a detailed description of the molecular kinetics and energetics of the primary processes in both types of PS II units. This characterization revealed that the PS IIalpha pool accounts for twice as many Chl molecules as PS IIbeta, which suggests a PSIIalpha/PSIIbeta reaction center stoichiometry of close to unity. By extrapolation it is shown that the primary charge separation in hypothetical "isolated" beta reaction centers is slower than in isolated alpha reaction centers: in open centers by a factor of 4 (1/k(1) (int) = 11 vs 2.9 ps), in closed centers by a factor of 2 (1/k(1) (int) = 34 vs 19 ps). Despite this slower charge separation process in PS IIbeta, the quantum efficiency of the charge separation process is hardly affected: a charge stabilization yield at F(0), (i.e., P(+)IQ(A) (-)) of 86% (as compared to 90% in PS IIalpha). Reduction of Q(A) (closing PS II) has distinctly different effects on the primary kinetics of PS IIbeta, as compared to PS IIalpha. In PS IIalpha the charge separation rate drops by a factor of 6, whereas the charge recombination process is hardly affected. In PS IIbeta the charge separation is slowed down by a factor of 3, whereas the charge recombination rate increases by a factor of 5. In terms of changes in standard free energy, the reduction to Q(A) (-) lifts the free energy of the radical pair P(+)I(-), relative to the excited state (Chl(n)/P)(*), by 47 meV in PS IIalpha and by 67 meV in PS IIbeta. The concomitant increase in fluorescence quantum yield is the same for both types of PS II. These results show that PS IIalpha and PS IIbeta exhibit a different molecular functioning with respect to the primary processes, which might have its origin in a different molecular structure of the reaction centers and/or a different local environment of these centers. Location in different parts of the thylakoid membrane might be involved. We also applied different error analysis procedures to determine the error ranges of the values found for the molecular rate constants. It is shown that the commonly used standard error has very little meaning, as it assumes independence of the fit parameters. Instead, an exhaustive search procedure, accounting for all possible correlations between the fit parameters, gives a more realistic view on the accuracy of the fit parameters.

Anatomically shaped tooth and periodontal regeneration by cell homing

Tooth regeneration by cell delivery encounters translational hurdles. We hypothesized that anatomically correct teeth can regenerate in scaffolds without cell transplantation. Novel, anatomically shaped human molar scaffolds and rat incisor scaffolds were fabricated by 3D bioprinting from a hybrid of poly-epsilon-caprolactone and hydroxyapatite with 200-microm-diameter interconnecting microchannels. In each of 22 rats, an incisor scaffold was implanted orthotopically following mandibular incisor extraction, whereas a human molar scaffold was implanted ectopically into the dorsum. Stromal-derived factor-1 (SDF1) and bone morphogenetic protein-7 (BMP7) were delivered in scaffold microchannels. After 9 weeks, a putative periodontal ligament and new bone regenerated at the interface of rat incisor scaffold with native alveolar bone. SDF1 and BMP7 delivery not only recruited significantly more endogenous cells, but also elaborated greater angiogenesis than growth-factor-free control scaffolds. Regeneration of tooth-like structures and periodontal integration by cell homing provide an alternative to cell delivery, and may accelerate clinical applications.

Intra-articular magnesium sulfate (MgSO4) reduces experimental osteoarthritis and nociception: association with attenuation of N-methyl-D-aspartate (NMDA) receptor subunit 1 phosphorylation and apoptosis in rat chondrocytes

OBJECTIVE

To study the effects of intra-articular injection of magnesium sulfate (MgSO(4)) on the development of osteoarthritis (OA) and to examine concomitant changes in the nociceptive behavior of rats.

METHODS

OA was induced in Wistar rats with intra-articular injection of collagenase (500 U) in the right knee; the left knee was left untreated. In the OA+MgSO(4) group (n=7), the treated knee was injected with 500-microg (0.1-ml) MgSO(4) twice a week for 5 consecutive weeks starting at 1 week after collagenase injection; in the OA group (n=7), the same knee was injected with the same amount of physiological normal saline. In the MgSO(4) group (n=6), naïve rats received only MgSO(4) injections; in the control group (n=6), naïve rats received only physiological normal saline injections. Nociceptive behavior (mechanical allodynia and thermal hyperalgesia) on OA development was measured before and at 1, 2, 4, 6, and 8 weeks after collagenase injection, following which the animals were sacrificed. Gross morphology and histopathology were examined in the femoral condyles, tibial plateau, and synovia. Immunohistochemical analysis was performed to examine the effect of MgSO(4) on N-methyl-D-aspartate (NMDA) receptor subunit 1 phosphorylation (p-NR1) and apoptosis in the articular cartilage chondrocytes.

RESULTS

OA rats receiving intra-articular MgSO(4) injections showed a significantly lower degree of cartilage degeneration than the rats receiving saline injections. MgSO(4) treatment also suppressed synovitis. Mechanical allodynia and thermal hyperalgesia showed significant improvement in the OA+MgSO(4) group as compared to the OA group. Moreover, MgSO(4) attenuated p-NR1 and chondrocyte apoptosis in OA-affected cartilage.

CONCLUSIONS

Our results indicate that local intra-articular administration of MgSO(4) following collagenase injection in an experimental rat OA model (1) modulates chondrocyte metabolism through inhibition of cell NMDA receptor phosphorylation and apoptosis, (2) attenuates the development of OA, and (3) concomitantly reduces nociception.

Food protective effect of geraniol and its congeners against stored food mites

The acaricidal activities of compounds derived from the oil of Pelargonium graveolens leaves against the storage food mite, Tyrophagus putrescentiae, were compared with the activity of a commercial acaricide, benzyl benzoate, in an impregnated fabric disk bioassay. Purification of the active constituent from P. graveolens was accomplished by silica gel chromatography and high-performance liquid chromatography. Structural analysis of the active constituent by 1H nuclear magnetic resonance (NMR), 13C-NMR, 1H-13C shift correlated spectroscopy NMR, and distortionless enhancement by polarization transfer NMR identified trans-3,7-dimethyl-2,6-octadien-1-ol (geraniol). Based on the 50% lethal dose values, the most toxic compounds against T. putrescentiae were geraniol (1.95 microg/cm3), which was followed by nerol (2.21 microg/cm3), citral (9.65 microg/cm3), benzyl benzoate (11.27 microg/cm3), and beta-citronellol (15.86 microg/cm3). Our results suggest that geraniol is more effective in controlling T. putrescentiae than benzyl benzoate is. Furthermore, geraniol, which is used as a flavoring for beverages, candies, ice creams, and baked goods and congeners (citral and nerol), may be useful for managing populations of T. putrescentiae.

The utilization of thin film transistor liquid crystal display waste glass as a pozzolanic material

This investigation elucidates the pozzolanic behavior of waste glass blended cement (WGBC) paste used in thin film transistor liquid crystal displays (TFT-LCD). X-ray diffraction (XRD) results demonstrate that the TFT-LCD waste glass was entirely non-crystalline. The leaching concentrations of the clay and TFT-LCD waste glass all met the current regulatory thresholds of the Taiwan EPA. The pozzolanic strength activity indices of TFT-LCD waste glass at 28 days and 56 days were 89% and 92%, respectively. Accordingly, this material can be regarded as a good pozzolanic material. The amount of TFT-LCD waste glass that is mixed into WGBC pastes affects the strength of the pastes. The strength of the paste clearly declined as the amount of TFT-LCD waste glass increased. XRD patterns indicated that the major difference was the presence of hydrates of calcium silicate (CSH, 2 theta=32.1 degrees), aluminate and aluminosilicate, which was present in WGBC pastes. Portland cement may have increased the alkalinity of the solution and induced the decomposition of the glass phase network. WGBC pastes that contained 40% TFT-LCD waste glass have markedly lower gel/space ratios and exhibit less degree of hydration than ordinary Portland cement (OPC) pastes. The most satisfactory characteristics of the strength were observed when the mixing ratio of the TFT-LCD waste glass was 10%.

The gep oncogenes, Galpha(12) and Galpha(13), upregulate the transforming growth factor-beta1 gene

Transforming growth factor-beta1 (TGFbeta1) plays a role in neoplastic transformation and transdifferentiation. Galpha(12) and Galpha(13), referred to as the gep oncogenes, stimulate mitogenic pathways. Nonetheless, no information is available regarding their roles in the regulation of the TGFbeta1 gene and the molecules linking them to gene transcription. Knockdown or knockout experiments using murine embryonic fibroblasts and hepatic stellate cells indicated that a Galpha(12) and Galpha(13) deficiency reduced constitutive, auto-stimulatory or thrombin-inducible TGFbeta1 gene expression. In contrast, transfection of activated mutants of Galpha(12) and Galpha(13) enabled the knockout cells to promote TGFbeta1 induction. A promoter deletion analysis suggested that activating protein 1 (AP-1) plays a role in TGFbeta1 gene transactivation, which was corroborated by the observation that a deficiency of the G-proteins decreased the AP-1 activity, whereas their activation enhanced it. Moreover, mutation of the AP-1-binding site abrogated the ability of Galpha(12) and Galpha(13) to induce the TGFbeta1 gene. Transfection of a dominant-negative mutant of Rho or Rac, but not Cdc42, prevented gene transactivation and decreased AP-1 activity downstream of Galpha(12) and Galpha(13). In summary, Galpha(12) and Galpha(13) regulate the expression of the TGFbeta1 gene through an increase in Rho/Rac-dependent AP-1 activity, implying that the G-protein-coupled receptor (GPCR)-Galpha(12) pathway is involved in the TGFbeta1-mediated transdifferentiation process.

Cell-culture-based immunochromatography for rapid detection of group A human rotaviruses in aquatic environments

In an effort to detect rapidly and conveniently the infectious waterborne group A human rotaviruses that cause diarrhea in infants and children, the authors developed the first-ever cell-culture-based immunochromatography method. An immunochromatography kit interacted only with the human rotaviruses VP6 antigen, and the cell-culture-based immunochromatography detected group A human rotaviruses with a sensitivity as low as 1.99 TCID50 ml(-1). This detection sensitivity was similar to that of the cytopathic effect-based method. There were no actual differences between the sensitivity of this method and that of the real-time reverse transcription polymerase chain reaction method, which is known as a method with a relatively high sensitivity. Furthermore, while cell culture detection methods, that is total culturable virus assay, can determine only the presence of infectious waterborne viruses, the cell-culture-based immunochromatography is advantageous for the accurate detection of group A human rotaviruses. Compared with the real-time reverse transcription polymerase chain reaction method, the cell-culture-based immunochromatography is advantageous because it requires a relatively simple process that enables easy quality controls and low test costs. Thus, this study proposed a new method for the identification of group A human rotaviruses, and it is suggested that this cell-culture-based immunochromatography may be applied to detect group A human rotaviruses in aquatic environments.

Predictors of bronchial hyperresponsiveness in chronic rhinosinusitis with nasal polyp

BACKGROUND

Chronic rhinosinusitis with nasal polyposis (CRSNP) and asthma are inflammatory lesions of the respiratory epithelium. This study was conducted to evaluate predictive factors of bronchial hyperresponsiveness (BHR) in patients with CRSNP.

METHODS

BHR was evaluated using a methacholine bronchoprovocation test (MBPT) in 122 consecutive patients newly diagnosed with CRSNP at Seoul National University Hospital from January 2004 to June 2006. The following parameters were analyzed and compared between the BHR and non-BHR groups: symptoms, atopic status, current smoking, disease severity of CRSNP based on the Lund-Mackay scoring system of sinus CT, and counts of eosinophils in the serum and nasal tissues.

RESULTS

Thirty-five percent of the patients were found to have BHR, and BHR was found to occur more frequently in patients that were currently suffering from sneezing (P = 0.007). In addition, the mean eosinophil counts of the serum and nasal tissues were higher in the BHR group than in the non-BHR group (P = 0.001 for the serum, P = 0.045 for the nasal tissues), and the eosinophil counts of the serum correlated to those of the nasal tissues (r = 0.334, P = 0.013). The disease severity, as determined by the Lund-Mackay scoring system, was not different between the two groups (P > 0.05). The best cutoff serum eosinophil count for predicting BHR in CRSNP patients was determined to be 300 cells/microl (sensitivity 70%, specificity 70%).

CONCLUSION

Taken together, these results indicate that moderate to severe sneezing and a serum eosinophil count > or = 300 cells/microl may be predictive factors for BHR in patients with CRSNP.

A lipid extract of Perna canaliculus affects the expression of pro-inflammatory cytokines in a rat adjuvant-induced arthritis model

As published initially in this same journal in 2000, the lipid extract of Perna canaliculus (New Zealand green-lipped mussel; Lyprinol) is known for its anti-inflammatory effects in animal models and in human controlled studies (arthritis; asthma). As a follow-up of its effects on pain in a rat model of adjuvant-induced arthritis (ALA), we studied its effects on the production of cytokines known to be associated with inflammation (IL-6, IL-1alpha TNF-alpha, IFN-gamma). Feeding with Lyprinol was associated with significantly decreased expression levels of TNF-alpha and IFN-gamma when compared to Naproxen (positive control) and, even more when compared with sham and extra-virgin olive oil (negative control). When compared to Naproxen, sham and extra-virgin olive oil, the levels of IL-6 and IL-1alpha were also marginally decreased in rats fed with Lyprinol. This study demonstrates that AIA rats fed with Lyprinol had decreased production ofcytokines associated with inflammation.

The effect of bupivacaine.HCl on the physical properties of neuronal membranes

Fluorescent probe techniques were used to evaluate the effect of bupivacaine.HCl on the physical properties (transbilayer asymmetric lateral and rotational mobilities, annular lipid fluidity and protein distribution) of synaptosomal plasma membrane vesicles (SPMVs) isolated from bovine cerebral cortex. An experimental procedure was used based on selective quenching of both 1,3-di(1-pyrenyl)propane (Py-3-Py) and 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups, and radiationless energy transfer (RET) from the tryptophans of membrane proteins to Py-3-Py. Bupivacaine.HCl increased the bulk lateral and rotational mobilities, and annular lipid fluidity in SPMVs lipid bilayers, and had a greater fluidizing effect on the inner monolayer than that of the outer monolayer. The magnitude of increasing effect on annular lipid fluidity in SPMVs lipid bilayer induced by bupivacaine.HCl was significantly far greater than magnitude of increasing effect of the drug on the lateral and rotational mobilities of bulk SPMVs lipid bilayer. It also caused membrane proteins to cluster. These effects of bupivacaine.HCl on neuronal membranes may be responsible for some, though not all, of the local anesthetic actions of bupivacaine.HCl.

Usefulness of concurrent reading using thin-section and thick-section CT images in subcentimetre solitary pulmonary nodules

AIM

To evaluate the differences in the characterization and recommendation for follow-up of subcentimetre solitary pulmonary nodules (SSPNs) between 5 and 1mm section CT, and to compare the assessments generated by four radiologists

MATERIALS AND METHODS

Five hundred and twenty-nine patients who had SSPNs on chest CT reconstructed using both 5 and 1mm sections were enrolled. Two image subsets of 5 and 1mm CT images of each nodule were interpreted independently by four radiologists. Nodule size, consistency (solid, partly solid, non-solid), the presence of calcification, and recommendations for follow-up were evaluated. If a non-calcified solid nodule was confirmed using CT, recommendation for follow-up was based on Fleischner Society guidelines. Data assessed by each radiologist were compared, and interobserver agreements were determined using the intraclass correlation coefficients and kappa value.

RESULTS

Using 1mm CT images, the nodule sizes were significantly larger than on 5mm CT images (paired t-test, p<0.01). The presence of calcification and nodule consistency were significantly different between 5 and 1mm CT images (McNemar test for the presence of calcification, p<0.01; Wilcoxon signed test for nodule consistency, p<0.01). On 1mm CT images there was significantly higher agreement regarding nodule consistency than on 5mm CT (kappa=0.78 and 0.67, respectively).

CONCLUSIONS

Concurrent use of thin-section and thick-section CT can provide more accurate nodule assessment and higher interobserver agreement in SSPN.

Biosorption of a reactive dye (Rhodamine-B) from an aqueous solution using dried biomass of activated sludge

Low cost, locally available biomaterial was tested for its ability to remove reactive dyes from aqueous solution. Granules prepared from dried activated sludge (DAS) were utilized as a sorbent for the uptake of Rhodamine-B (Rh-B) dye. The effects of various experimental parameters (dye concentration, sludge concentrations, swelling, pretreatment and other factors) were investigated and optimal experimental conditions were ascertained. Nearly 15min was required for the equilibrium adsorption, and Rh-B dyes could be removed effectively. Dye removal performance of Rh-B and DAS increased with increasing concentrations. The acid pretreated biomass exhibited a slightly better biosorption capacity than alkali pretreated or non-pretreated biomass. The optimum swelling time for dye adsorption of the DAS within the swelling time range studied was 12h. Both the Freundlich and Langmuir isotherm models could describe the adsorption equilibrium of the reactive dye onto the activated sludge with the Langmuir isotherm showing the better agreement of the two. Second-order kinetic models confirmed the agreement.

An improved enzyme assay for molybdenum-reducing activity in bacteria

Molybdenum-reducing activity in the heterotrophic bacteria is a phenomenon that has been reported for more than 100 years. In the presence of molybdenum in the growth media, bacterial colonies turn to blue. The enzyme(s) responsible for the reduction of molybdenum to molybdenum blue in these bacteria has never been purified. In our quest to purify the molybdenum-reducing enzyme, we have devised a better substrate for the enzyme activity using laboratory-prepared phosphomolybdate instead of the commercial 12-phosphomolybdate we developed previously. Using laboratory-prepared phosphomolybdate, the highest activity is given by 10:4-phosphomolybdate. The apparent Michaelis constant, Km for the laboratory-prepared 10:4-phosphomolybdate is 2.56 +/- 0.25 mM (arbitrary concentration), whereas the apparent V(max) is 99.4 +/- 2.85 nmol Mo-blue min(-1) mg(-1) protein. The apparent Michaelis constant or Km for NADH as the electron donor is 1.38 +/- 0.09 mM, whereas the apparent V(max) is 102.6 +/- 1.73 nmol Mo-blue min(-1) mg(-l) protein. The apparent Km and V(max) for another electron donor, NADPH, is 1.43 +/- 0.10 mM and 57.16 +/- 1.01 nmol Mo-blue min(-1) mg(-1) protein, respectively, using the same batch of molybdenum-reducing enzyme. The apparent V(max) obtained for NADH and 10:4-phosphomolybdate is approximately 13 times better than 12-phoshomolybdate using the same batch of enzyme, and hence, the laboratory-prepared phosphomolybdate is a much better substrate than 12-phoshomolybdate. In addition, 10:4-phosphomolybdate can be routinely prepared from phosphate and molybdate, two common chemicals in the laboratory.

Percutaneous radiofrequency ablation of liver dome hepatocellular carcinoma invisible on ultrasonography: a new targeting strategy

Targeting of index tumours is prerequisite to their radiofrequency ablation. However, small hepatocellular carcinomas (HCCs) in the liver dome are often invisible on ultrasonography, thus causing difficulty in their targeting. In cases with multinodular HCCs, adjacent HCC lesions with compact iodized oil retention can be used as anatomic landmarks to guide radiofrequency (RF) ablation of such nodules under fluoroscopy. We present two cases in which nodules that were difficult to target with conventional methods were successfully treated by RF ablation using this targeting strategy.

Involvement of the BLT2 receptor in the itch-associated scratching induced by 12-(S)-lipoxygenase products in ICR mice

BACKGROUND AND PURPOSE

Recently, we reported that 12(S)-HPETE (12(S)-hydroperoxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid) induces scratching in ICR mice. We hypothesized that 12(S)-HPETE might act as an agonist of the low-affinity leukotriene B4 receptor BLT2. To confirm the involvement of the BLT2 receptor in 12(S)-HPETE-induced scratching, we studied the scratch response using the BLT2 receptor agonists compound A (4'-[[pentanoyl (phenyl) amino]methyl]-1,1'-biphenyl-2-carboxylic acid) and 12(S)-HETE (12(S)-hydroxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid).

EXPERIMENTAL APPROACH

A video recording was used to determine whether the BLT2 receptor agonists caused itch-associated scratching in ICR mice. Selective antagonists and several chemicals were used.

KEY RESULTS

Both 12(S)-HETE and compound A dose dependently induced scratching in the ICR mice. The dose-response curve for compound A showed peaks at around 0.005-0.015 nmol per site. Compound A- and 12(S)-HETE-induced scratching was suppressed by capsaicin and naltrexon. We examined the suppressive effects of U75302 (6-[6-(3-hydroxy-1E,5Z-undecadienyl)-2-pyridinyl]-1,5-hexanediol, the BLT1 receptor antagonist) and LY255283 (1-[5-ethyl-2-hydroxy-4-[[6-methyl-6-(1H-tetrazol-5-yl)heptyl]oxy]phenyl]-ethanone, the BLT2 receptor antagonist) on the BLT2 agonist-induced scratching. LY255283 suppressed compound A- and 12(S)-HETE-induced scratching, but U75302 did not. LY255283 required a higher dose to suppress the compound A-induced scratching than it did to suppress the 12(S)-HETE-induced scratching. One of the BLT(2) receptor agonists, 12(R)-HETE (12(R)-hydroxyeicosa-5Z,8Z,10E,14Z-tetraenoic acid), also induced scratching in the ICR mice.

CONCLUSIONS AND IMPLICATIONS

Our present results corroborate the hypothesis that the BLT2 receptor is involved in 12(S)-lipoxygenase-product-induced scratching in ICR mice. We also confirmed that this animal model could be a valuable means of evaluating the effects of BLT2 receptor antagonists.

Conformation studies of 13 trinucleoside diphosphates by 360 MHz PMR spectroscopy. A bulged base conformation. I. Base protons and H1' protons

The 360 MHz NMR spectra of the base protons and the H1 protons of thirteen trinucleoside diphosphates have been analyzed. The sequences chosen represent all purine-pyrimidine sequences. The chemical shifts of the base protons give evidence for strong next nearest-neighbor effects in some oligonucleotides. Although increasing chain length usually increases nearest-neighbor base-base stacking, it is not always so. Comparing ApCpG, ApUpG and GpUpG to their component dimers, one finds a decrease in stacking of the center pyrimidine with the purine on either side. The coupling constants J 1'2' also show that these three trimers show less stacking for their terminal residues than expected from their component dimers. We conclude that the sequence Pu-Py-Pu favors a conformation in which the pyrimidine is bulged out and the two purines stack on each other.

Registration of sheep brain MR images for cell tracking using ferrite-composite micro-beads as markers

In the recent molecular imaging studies of the magnetic resonance imaging field, in-vivo cell tracking is becoming an issue for the observation of cell therapy and disease behavior. In order to perform cell tracking, high resolution images and long-term studies are required, because those images make better performance than low resolution images in the recognition of cells and cells are traced at least two weeks. Image registration is an essential image processing technique for long-term imaging. In this study, we proposed the image registration technique using ferrite-composite micro- beads which could be used as substitutes for the cells labeling MR contrast agent such as superparamagnetic iron oxide (SPIO) nanoparticles. Registration of sheep brain images tagging micro-beads was performed with the sufficient accuracy for cell tracking.

Transcatheter embolization of a pseudoaneurysm of the inferior epigastric artery with N-butyl cyanoacrylate

A 41-year-old man presented with alcoholic liver cirrhosis with ascites and clotting abnormality. After therapeutic paracentesis, haemoperitoneum ensued without colour Doppler ultrasound or CT evidence of pseudoaneurysm or haematoma at the site of paracentesis. However, an angiogram of the inferior epigastric artery revealed an obvious small pseudoaneurysm arising from its small muscular branch, and this pseudoaneurysm was successfully treated by transcatheter embolization with N-butyl cyanoacrylate. Transcatheter embolization with N-butyl cyanoacrylate is useful treatment for pseudoaneurysms arising from the small muscular branch of the inferior epigastric artery, which cannot be catheterized superselectively close to the pseudoaneurysm.

Document retrieval using fuzzy-valued concept networks

This paper presents a new method for document retrieval using fuzzy-valued concept networks, where the relevant degrees between the concepts in a fuzzy-valued concept network are represented by arbitrary shapes of fuzzy numbers. There are two kinds of relevant relationships between any two concepts in a fuzzy-valued concept network, i.e., fuzzy positive association and fuzzy negative association. The relevant matrices and the relationship matrices are used to model the fuzzy-valued concept network. The elements in a relevant matrix represent the relevant degrees between concepts. The elements in a relationship matrix represent the relevant relationships between concepts. Furthermore, ne also allow users' queries to be represented by arbitrary shapes of fuzzy numbers and to use fuzzy positive association relationship and fuzzy negative association relationship for formulating their queries for increasing the flexibility of fuzzy information retrieval systems. We also present an information retrieval method in the Internet environment based on the network-type fuzzy-valued concept network architecture.

Suppression and recovery of the hypothalamic function after high-dose corticosteroid treatment in preterm infants

BACKGROUND

High-dose systemic dexamethasone is effective in facilitating extubation of ventilated infants with bronchopulmonary dysplasia. Although the suppression and recovery of pituitary-adrenal response had been assessed after corticosteroid treatment in very low birth weight infants, its effect on hypothalamic function has not been longitudinally monitored.

AIMS

This study was designed to assess the longitudinal hypothalamic response before, during and 4 weeks after a 3-week dose-tapering course of systemic dexamethasone treatment.

PATIENTS AND METHODS

Twenty very low birth weight infants had blood collected for corticotropin-releasing hormone, ACTH and cortisol measurements immediately before starting dexamethasone (week 0), after receiving the maximum dose of treatment (week 1), at the end of the 3-week course (week 3) and 4 weeks after stopping corticosteroids (week 7).

RESULTS

All circulating hormone concentrations were significantly suppressed during the treatment period at week 1 and week 3 compared with pretreatment concentrations at week 0 (p < 0.001). The recovery of pituitary function started early soon after week 1, whereas that of hypothalamus and adrenal functions started after the end of the dexamethasone course. Plasma ACTH concentration at week 7 had returned to the pretreatment level, but plasma corticotropin-releasing hormone (p < 0.05) and serum cortisol (p < 0.001) concentrations remained significantly suppressed. Partial recovery of hypothalamic and adrenal function was observed at week 7 (62 vs. 36% of their pretreatment levels, respectively).

CONCLUSION

Our findings suggest that the hypothalamic function is suppressed during systemic corticosteroid treatment but partial recovery occurs 4 weeks after stopping therapy. Even in preterm infants, the hypothalamic-pituitary-adrenal axis behaves in a similar manner as in adult subjects and the pituitary function recovers earlier than that of hypothalamus and adrenals.

MicroRNA expression signature of human sarcomas

MicroRNAs (miRNAs) are approximately 22 nucleotide-long noncoding RNAs involved in several biological processes including development, differentiation and proliferation. Recent studies suggest that knowledge of miRNA expression patterns in cancer may have substantial value for diagnostic and prognostic determinations as well as for eventual therapeutic intervention. We performed comprehensive analysis of miRNA expression profiles of 27 sarcomas, 5 normal smooth muscle and 2 normal skeletal muscle tissues using microarray technology and/or small RNA cloning approaches. The miRNA expression profiles are distinct among the tumor types as demonstrated by an unsupervised hierarchical clustering, and unique miRNA expression signatures were identified in each tumor class. Remarkably, the miRNA expression patterns suggested that two of the sarcomas had been misdiagnosed and this was confirmed by reevaluation of the tumors using histopathologic and molecular analyses. Using the cloning approach, we also identified 31 novel miRNAs or other small RNA effectors in the sarcomas and normal skeletal muscle tissues examined. Our data show that different histological types of sarcoma have distinct miRNA expression patterns, reflecting the apparent lineage and differentiation status of the tumors. The identification of unique miRNA signatures in each tumor type may indicate their role in tumorigenesis and may aid in diagnosis of soft tissue sarcomas.

Data acquisition system for an advanced x-ray imaging crystal spectrometer using a segmented position-sensitive detector

A versatile time-to-digital converter based data acquisition system for a segmented position-sensitive detector has been developed. This data acquisition system was successfully demonstrated to a two-segment position-sensitive detector. The data acquisition system will be developed further to support multisegmented position-sensitive detector to improve the photon count rate capability of the advanced x-ray imaging crystal spectrometer system.

Biosynthesis of antibiotic prodiginines in the marine bacterium Hahella chejuensis KCTC 2396

AIMS

Hahella chejuensis KCTC 2396 produces red pigments, showing antibacterial and algicidal activities. The main red-coloured metabolite of the pigments was identified as antibiotic prodigiosin. With the expectation that the red pigments are a mixture of a series of close relatives, the aim of the present study is to detect new antibiotic prodigiosin analogues and to analyse the biosynthetic pattern for prodiginines in KCTC 2396.

METHODS AND RESULTS

Except prodigiosin, the other constituents in the red pigments were confirmed as well-known dipyrrolyldipyrromethene prodigiosin, norprodigiosin, and undecylprodiginine. Additionally, four new prodigiosin analogues, each of which was distinguished from prodigiosin (C(5)), according to differences in alkyl chain length (C(3)-C(7)), were detected in small quantities by liquid chromatography mass spectrometry/mass spectrometry spectroscopy. Owing to the presence of a cytotoxic methoxy group, it is expected that all the new prodigiosin analogues are bioactive.

CONCLUSIONS

Four characterized prodiginines, including prodigiosin and four new prodigiosin analogues are produced in different ratio in KCTC 2396. All of the prodiginines possess a common linear tripyrrolyl structure and a cytotoxic methoxy group.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study shows for the first time that KCTC 2396 is able to produce antibiotic prodigiosin, undecylprodiginine and new prodigiosin analogues in a mixture of pigments. It is also shown that KCTC 2396 possesses a novel system for the simultaneous production of multiple prodiginines in a single micro-organism.

Effects of the surface pH on interfacial interactions of collagen-elastin matrix

This study is aimed to elucidate the effects of surface pH of bioprosthetic heart valve (BHV) on their binding property to calcium and protein. It is hypothesized that the binding affinities of the BHV for calcium and protein are surface pH dependent. To test this hypothesis, collagen-elastin matrix (CEM) made of varying ratios of collagen and elastin were used as calcifiable matrices to simulate the calcium binding process of BHV. The calcium binding profiles of CEM, whose surface pHs were adjusted at 3.4, 5.0 or 7.4, were examined by either incubating CEM in the buffer solutions containing various calcium concentrations or implanting CEM in the rat subcutaneous model. The amounts of calcium and protein bound to CEM decreased as the surface pH of CEM decreased. The calcium level in the CEM (pH 7.4) was 2.32+/-0.8 as compared with 1.23+/-0.35 (microg/mg) in CEM (pH 3.4). The equilibrium dissociation constant (Kd) was in a reciprocal relationship with the surface pH. This study demonstrated that the affinity of CEM for calcium is surface pH dependent and provided basic information about the role of surface properties in BHV calcification.

Portable microscopic cell counter for the determination of residual leucocytes in blood components

BACKGROUND AND OBJECTIVES

The accurate determination of residual white blood cell (WBC) in blood components is of considerable clinical importance, and a variety of methods have been devised for the counting of low levels of residual WBC. In this study, we evaluated the performance of microscopic cell counter with microchannel plastic chip (C-reader) with regard to its ability to quantify WBC in WBC-reduced red cell concentrates.

MATERIALS AND METHODS

In order to quantify residual WBC with the microscopic cell counter, WBC-reduced red cell concentrate was stained using propidium iodide. Three studies were performed: linearity, precision and correlation compared to those of manual Nageotte chamber counting and automatic flow cytometric methods.

RESULTS

Dilution experiments, conducted over a range of 0.7-712 WBC/microl, showed a linearity of r(2) > 0.999, with coefficient of variation values of < or = 15.6% and accuracy of 93.8% over all tested ranges. In comparison with the Nageotte chamber counting and flow cytometric methods, the correlation coefficients were r(2) > 0.995. The detection limit of this method was 0.24 WBC/microl. Total analysis time per sample was approximately 5 min.

CONCLUSION

The microscopic cell counter for residual WBC counting was determined to be efficient at the level of currently defined standards, with acceptable precision and accuracy. This method may prove useful for the quality assurance and control of WBC-depleted blood products.

Effects of temperature on the mechanical properties of single stranded DNA

We present the first measurements of the temperature dependent extension of single stranded DNA. At forces between 2 and 10 pN the extension increases with temperature. This increase in extension is consistent with the disruption of hairpins, and a simple theory that includes hairpin formation shows good agreement with the data at these low forces. In contrast, at forces above 10 pN and temperatures higher than 40 degrees C, the extension decreases rapidly with temperature in a manner not consistent with predictions.

Electronic and optical properties of finite carbon nanotubes in an electric field

The effects, caused by the geometric structure and an electric field (E), on the electronic and optical properties of quasi-zero-dimensional finite carbon nanotubes are explored by employing the tight-binding model coupled with curvature effects. Electronic properties (state energies, symmetry of electronic states, energy spacing and state degeneracy) are significantly affected by the magnitude and the direction of the electric field and the geometric structure (radius, length and chirality). The electric field, by lowering the symmetry of finite carbon nanotubes, modifies the electronic properties. Thus, the optical excitation spectra, excited by electric polarization parallel to the nanotube axis, exhibit rich delta-function-like peaks, which reveal the characteristics of the electronic properties. Therefore it follows that geometric structure and E influence the low-energy absorption spectra, i.e. the change of frequency of the first peak, the alternation of the peak height and the production of the new peaks. There are more absorption peaks when E is oriented closer to the cross-section plane. Moreover, the very complicated optical absorption spectra are characteristic for the individual chiral carbon nanotube due to its specific geometric structure. Above all, the predicted absorption spectra and the associated electronic properties could be verified by optical measurements.

Determination of optimal timing window for pulmonary artery MDCT angiography

OBJECTIVE

The purpose of our study was to determine the optimal timing window for pulmonary artery MDCT angiography.

SUBJECTS AND METHODS

We prospectively studied 150 patients. Routine chest CT scans were acquired using 1.3 mL/kg of contrast medium (370 mg I/mL) that was injected at a fixed injection duration of 30 seconds, followed by a 10-second saline chase. To measure early contrast enhancement, sequential monitoring scans were obtained every 2 seconds over a fixed level of the main pulmonary artery 5 seconds after the start of the injection. Then helical diagnostic scans were obtained at three different predetermined scanning delays (group A, 25 seconds; group B, 35 seconds; and group C, 45 seconds after the start of the injection). Time-enhancement curves; time to reach 100 H, 200 H, and peak enhancement; and enhancement duration greater than 200 H of the pulmonary artery were measured from the monitoring scan. Contrast enhancements of the pulmonary artery and descending aorta and vascular artifacts were assessed from the diagnostic scan.

RESULTS

Times to reach 100 H and 200 H at the pulmonary artery were mean 11 +/- 2.5 (SD) seconds and 16 +/- 3.0 seconds, respectively. Pulmonary artery enhancement duration of greater than 200 H was 25 +/- 2.7 seconds (only obtained in group C). Mean time to peak enhancement (335 +/- 62 H) at the pulmonary artery was 37 seconds. Mean enhancement measured on the diagnostic scan was 294 +/- 43 H, group A; 208 +/- 48 H, group B; and 157 +/- 15 H, group C for the pulmonary artery, and 240 +/- 42 H, group A; 277 +/- 49 H, group B; and 172 +/- 29 H, group C for the aorta (p < 0.01). Artifacts were noted in the superior vena cava (group A, 96.7%; group B, 18.3%; and group C, 0%) and in the subclavian vein (group A, 93.5%; group B, 38.7%; and group C, 0%), (p < 0.05).

CONCLUSION

With our study protocol of a 30-second injection and 10-second saline flush, the optimal temporal window to achieve pulmonary artery enhancement greater than 200 H was from 16 seconds to 41 seconds after the start of the injection.

Role of the C-reactive protein for the diagnosis of TB among military personnel in South Korea

Clinicians are frequently faced with the task of differentiating between pulmonary tuberculosis (PTB) and pneumonia. We evaluated the role of the C-reactive protein test (CRP) for differentiating between TB and pneumonia among military personnel in South Korea. Only immunocompetent males were eligible. Forty-six patients with PTB and 67 with pneumonia were enrolled prospectively. Median CRP concentration was lower in patients with TB than in patients with non-tuberculous pneumonia (3.2 mg/dl [range 0.1-15.7 mg/dl] vs. 8.3 mg/dl [range 0.2-33.7 mg/dl], P < 0.001). The sensitivity and specificity for TB of a low CRP concentration (< 11.2 mg/dl) in serum was 93.3% and 40.9%, respectively. CRP concentration measurement might be useful for eliminating the diagnosis of TB.

An intelligent data mining model approach for adverse effects of hormone replacement therapy

OBJECTIVES

A number of controversial studies have been reported on the potential risk of breast cancer caused by hormone replacement therapy (HRT). Some studies showed a positive relationship between HRT and breast cancer onset, but other studies have not confirmed these results. To clarify the contradictory outcomes in the relationships between HRT and the onset of breast cancer, we have designed an intelligent data mining model (IDM), which is able to find proper prognostic factors for cancer onset and provides alternate measures in interpretation of outcome of clinical data through hierarchies of attributes.

METHODS

Based on the selection criteria, we selected 22 sets of random and case-control studies of the last 15 years, which identified any involvements of HRT with breast cancer. We analyzed the relationship between HRT and breast cancer using an IDM model consisting of data mining algorithms and public domain data mining tools. Prognostic factors which underline the major etiological dispositions of breast cancer were identified.

RESULTS

The variables which are closely associated with cancer onset to some degree are age 60-69, age at menopause 40-49, parity 0, age 40-49, and types of menopause oophorectomy. An implementation of IDM model on overall pooled data indicated that there is no significant relationship between breast cancer onset and HRT. It is suggested that HRT patients with specific physiological and pathological conditions related with the higher ranks of prognostic factors may have a greater chance to get breast cancer.

CONCLUSION

The results of this study may guide biomedical research directed at establishing the causal relationships between various medications and their complications, allowing an accurate assessment of efficacy and side effects of new therapeutic treatment in clinical trials without reliance on a large control population.

The role of TST in the diagnosis of latent tuberculosis infection among military personnel in South Korea

BACKGROUND

The rapid and accurate diagnosis of latent tuberculosis infection (LTBI) is crucial in military settings because military personnel live in crowded circumstances and are of an age group with a high incidence of tuberculosis (TB). We tried to elucidate whether the tuberculin skin test (TST) accurately reflects the risk of TB infection among military personnel, in a setting of intermediate TB prevalence and where bacille Calmette-Guérin (BCG) vaccination is mandatory.

METHODS

A multi-stage cluster survey was conducted among military personnel in South Korea. Participants were grouped according to their risk of TB infection: Group 1, no identifiable risk of TB; Groups 2 and 3, recent casual (Group 2) or close (Group 3) contact with smear-positive TB patients.

RESULTS

Of 1045 participants, 857 (82.0%) had been BCG-vaccinated. The odds ratio (OR) of a positive TST (10 mm cut-off) for Group 2 (n = 184) and Group 3 (n = 83) compared with Group 1 (n = 778) were 0.95 (95%CI 0.67-1.38) and 1.7 (95%CI 1.06-2.70), respectively (P value for trend 0.16).

CONCLUSIONS

The TST does not accurately reflect the risk of LTBI among young military personnel in a setting where there is intermediate TB prevalence and extensive BCG coverage.

Endothelin-1 regulates parathyroid hormone expression of human parathyroid cells

OBJECTIVE

Parathyroid cells synthesize and release endothelin-1 (ET-1). ET-1 displays an in vitro inhibitory effect on basal parathyroid hormone (PTH) secretion and also counteracts PTH hypersecretion stimulated by low calcium. Such effects are further demonstrated in vivo, independent of the changes in calcitonin. We propose that ET-1 may regulate the pathogenesis of uremic hyperparathyroidism. However, this was not directly demonstrated in human parathyroid glands.

DESIGN

Hyperplastic parathyroid glands are obtained from the surgical operation for uremic hyperparathyroidism. Cells are isolated by enzyme digestion and treated with ET-1, and are assessed for PTH mRNA expression. PTH in the plasma and the medium is measured by a newly developed method to detect the whole PTH (1-84).

PATIENTS

Uremic patients with severe secondary hyperparathyroidism and ultrasonography-proved hypertrophy of parathyroid glands received elective surgical approaches under general anesthesia. The resected glands were immediately taken to the laboratory for fresh isolation.

MEASUREMENTS

Following ET-1 treatment, PTH mRNA expression is evaluated by RT-PCR method. ET-1 is detected with radioimmunoassay kit and PTH is measured by a new commercially available Duo PTH kit.

RESULTS

ET-1 exhibited a dose-dependent inhibitory effect (from 10(-12) - 10(-7) M) on PTH mRNA expression of parathyroid cells, either in the basal or in the low-calcium-stimulated states. Release of PTH into the medium is also gradually inhibited by the increase in ET-1 concentrations.

CONCLUSIONS

Our results demonstrate that ET-1 attenuates PTH mRNA expression in freshly isolated human parathyroid cells, and PTH release is also decreased. This result is consistent with our previously reported in vitro and in vivo experiments.

Resistance to adefovir dipivoxil in lamivudine resistant chronic hepatitis B patients treated with adefovir dipivoxil

BACKGROUND

Adefovir dipivoxil (ADV) is a potent nucleotide analogue against both the wild-type and lamivudine (LMV) resistant hepatitis B virus (HBV). The cumulative incidence of ADV resistant mutations in the nucleoside/-tide treatment naive chronic hepatitis B patient (CHB) at weeks 48, 96, and 144 was 0, 0.8-3%, and approximately 5.9%, respectively.

AIMS

The aim of this study was to characterise the genotypic and phenotypic mutation profiles to ADV in 67 LMV resistant CHB patients who were treated with ADV.

METHODS

Serum HBV DNA was quantified by real time polymerase chain reaction. The ADV mutant was detected using matrix assisted laser desorption/ionisation time of flight mass spectrometry based genotyping assays, termed restriction fragment mass polymorphism (RFMP).

RESULTS

RFMP analysis revealed that a total of 11 amino acid substitutions developed in the rt domain of the HBV polymerase in nine patients. The cumulative incidence of genotypic ADV resistance at months 12 and 24 was 6.4% and 25.4%, respectively. The rtA181V, rtN236T, and rtA181T mutations were detected in five, four, and two of the 67 patients at treatment months 12-17, 3-19, and 7-20, respectively. Serial quantification of serum HBV DNA revealed that two patients with the rtA181V mutation, with or without the rtN236T mutation, and one patient with the rtA181T mutation displayed HBV DNA rebound.

CONCLUSION

Emergence of the ADV mutation in LMV resistant patients who are treated with ADV appeared to present earlier and more frequently than was reported in previous studies on nucleoside/-tide treatment naive patients.

Successful outpatient treatment of renal vein thrombosis by low-molecular weight heparins in 3 patients with nephrotic syndrome

Renal vein thrombosis (RV Thromb) is a serious complication ofnephrotic syndrome. Anticoagulation is usually recommended as the treatment of choice. This study reports 3 nephrotic patients diagnosed to have RVThromb combined with thromboembolic events. Low-molecular weight heparin (LMWHep) was given subcutaneously every 12 hours following the diagnosis of RVTromb, which continued at the outpatient clinic after an average of 11 in-hospital days. The patients visited the nephrology outpatient clinic every other week and underwent magnetic resonance image (MRI) studies at 6-week intervals for follow-up of patency of the involved renal vein. LMWHep was discontinued when MRI showed this patency. The average outpatient treatment period was 74 days. There was no recurrent RVThromb in the follow-up course of 6 months after discontinuation of LMWHep. Kidney function was preserved, as indicated by image studies and serial renal function tests. LMWHep produced a more predictable anti-coagulant effect, a superior bioavailability, a longer half-life and a dose-independent effect than unfractionated heparin and coumadin. These benefits made the outpatient treatment of RVThromb possible. Our report recommends outpatient treatment of RVThromb by LMWHep because it is feasible, effective and safe.

An orally active cathepsin K inhibitor, furan-2-carboxylic acid, 1-{1-[4-fluoro-2-(2-oxo-pyrrolidin-1-yl)-phenyl]-3-oxo-piperidin-4-ylcarbamoyl}-cyclohexyl)-amide (OST-4077), inhibits osteoclast activity in vitro and bone loss in ovariectomized rats

Human cathepsin K, a cysteine proteinase of the papain family, has been recognized as a potential drug target for the treatment of osteoporosis. The predominant expression of cathepsin K in osteoclasts has rendered the enzyme into a major target for the development of novel antiresorptive drugs. Now, we report the pharmacological properties of OST-4077 [furan-2-carboxylic acid (1-{1-[4-fluoro-2-(2-oxo-pyrrolidin-1-yl)-phenyl]-3-oxo-piperidin-4-ylcarbamoyl}-cyclohexyl)-amide] as a novel selective cathepsin K inhibitor. Human and rat cathepsin K were inhibited in vitro by OST-4077 with the IC50 values of 11 and 427 nM, respectively. OST-4077 suppressed bone resorption induced by rabbit osteoclasts (IC50, 37 nM) but did not affect bone mineralization or cellular alkaline phosphatase activity in MC3T3-E1 cells. Parathyroid hormone-induced bone resorption was inhibited in a dose-dependent manner in thyroparathyroidectomized rats gavaged with a single dose of OST-4077 (ED50, 69 mg/kg). When given orally twice daily for 4 weeks to 3-month-old ovariectomized (OVX) rats, OST-4077 dose-dependently prevented bone loss, as monitored by bone densitometry, ash content, and urinary excretion of deoxypyridinoline. No change in serum osteocalcin in the OVX rats by OST-4077 suggested that bone formation might not be affected by the agent. In summary, OST-4077 selectively inhibited bone resorbing activities of osteoclasts and prevented bone loss induced by estrogen deficiency but did not affect bone formation. OST-4077, an orally active selective human cathepsin K inhibitor, may have the therapeutic potential for the treatment of diseases characterized by excessive bone loss including osteoporosis.

Recognising tuberculosis in the lower lung field: an age- and sex-matched controlled study

OBJECTIVE

Tuberculosis (TB) can sometimes present with consolidation in the lower lung field. This study was conducted to compare the manifestations of lower-lung-field TB (LLFTB) and other pulmonary TB.

DESIGN

All new culture-proven TB patients with lower-lung-field consolidation from July 2001 through December 2002 were included. Age- and sex-matched TB patients with upper lung involvement were selected as controls.

RESULTS

A total of 79 patients with LLFTB were included. Their mean age was 58.8 years; 46 were male. The clinical, radiographic and laboratory findings were similar in the LLFTB and the control groups, except that the LLFTB patients had less cavitation (P = 0.005). Patients with LLFTB were diagnosed (P = 0.051) and treated (P = 0.001) later than the control patients. The calibres of the trachea and both main bronchi were significantly smaller in the LLFTB group (P < 0.001). More patients with LLFTB developed segmental or lobar atelectasis during follow-up (P = 0.028).

CONCLUSIONS

The manifestations of LLFTB are non-specific. The lower-lung involvement, the lower incidence of cavitation and the higher probability of segmental or lobar atelectasis implied that LLFTB was primary TB. A small bronchial calibre probably contributed to its development.

Comparison of the measured phase diagrams in the force-temperature plane for the unzipping of two different natural DNA sequences

In this work, we consider the critical force required to unzip two different naturally occurring sequences of double-stranded DNA (dsDNA) at temperatures ranging from 20 degrees C to 50 degrees C, where one of the sequences has a 53% average guanine-cytosine (GC) content and the other has a 40% GC content. We demonstrate that the force required to separate the dsDNA of the 53% GC sequence into single-stranded DNA (ssDNA) is approximately 0.5 pN, or approximately 5% greater than the critical force required to unzip the 40% GC sequence at the same temperature. In the temperature range between 20 and 40 degrees C the measured critical forces correspond reasonably well to predictions based on a simple theoretical homopolymeric model, but at temperatures above 40 degrees C the measured critical forces are much smaller than the predicted forces. The correspondence between theory and experiment is not improved by using Monte Carlo simulations that consider the heteropolymeric nature of the sequences.

Growth and photosynthetic responses of two pine species (Pinus koraiensis and Pinus rigida) in a polluted industrial region in Korea

We investigated the effects of pollutants on two pine species (Pinus koraiensis and Pinus rigida) in an industrial region in Korea, using a physiological approach. The concentrations of fluorine (F) and chlorine (Cl) in the atmosphere, in precipitation and soil water at the damaged site were all significantly higher than at a control site. Moreover, the concentrations of F, Cl and Mn in pine needles were significantly higher, and essential elements and chlorophyll in needles were significantly lower at the damaged site than at the control site. The photosynthetic capacities, shoot length and survival statistics of needles of the two pines were all significantly reduced at the damaged site compared to the control site, especially P. rigida. Based on our comparison of photosynthetic responses and the concentrations of F, Cl and Mn in needles of the two pine species, P. koraiensis is more resistant to excess Mn in its needles than P. rigida.

Unusual renal cell carcinomas: a pictorial essay

Renal cell carcinoma (RCC) is the most common solid renal neoplasm. Clear cell (conventional) carcinoma is the most common pathologic subtype of RCC. Usually RCC is a hypervascular, solid, solitary mass with contour bulging. However, RCC can manifest different features according to the pathologic tumor subtypes. Preoperative diagnosis of cyst-associated RCC is very difficult, especially in cases of RCC originating in a cyst. Multiple or bilateral presentation of RCC occurs in fewer than 5% of cases. In addition, RCCs may demonstrate unusual findings such as infiltrative growth mimicking transitional cell carcinoma, fatty component mimicking angiomyolipoma, severe perinephric infiltration, and extensive calcifications mimicking inflammation or other tumor. RCCs can be associated with hereditary diseases such as von Hippel-Lindau disease. Familiarity with these radiologic features of unusual RCCs can help ensure correct diagnosis and proper management.