Relationship between tumor cell infiltration and 5-aminolevulinic acid fluorescence signals after resection of MR-enhancing lesions and its prognostic significance in glioblastoma

PURPOSE

This study investigated the degree of tumor cell infiltration in the tumor cavity and ventricle wall based on fluorescent signals of 5-aminolevulinic acid (5-ALA) after removal of the magnetic resonance (MR)-enhancing area and analyzed its prognostic significance in glioblastoma.

METHODS

Twenty-five newly developed isocitrate dehydrogenase (IDH)-wildtype glioblastomas with complete resection both of MR-enhancing lesions and strong purple fluorescence on resection cavity were retrospectively analyzed. The fluorescent signals of 5-ALA were divided into strong purple, vague pink, and blue colors. The pathologic findings were classified into massively infiltrating tumor cells, infiltrating tumor cells, suspicious single-cell infiltration, and normal-appearing cells. The pathological findings were analyzed according to the fluorescent signals in the resection cavity and ventricle wall.

RESULTS

There was no correlation between fluorescent signals and infiltrating tumor cells in the resection cavity (p = 0.199) and ventricle wall (p = 0.704) after resection of the MR-enhancing lesion. The median progression-free survival (PFS) and median overall survival (OS) were 12.5 (± 2.1) and 21.1 (± 3.5) months, respectively. In univariate analysis, the presence of definitive infiltrating tumor cells in the resection cavity and ventricle wall was significantly related to the PFS (p = 0.002) and OS (p = 0.027). In multivariate analysis, the absence of definitive infiltrating tumor cells improved PFS (hazard ratio: 0.184; 95% CI: 0.049-0.690, p = 0.012) and OS (hazard ratio: 0.124; 95% CI: 0.015-0.998, p = 0.050).

CONCLUSIONS

After resection both of the MR-enhancing lesions and strong purple fluorescence on resection cavity, there was no correlation between remnant fluorescent signals and infiltrating tumor cells. The remnant definitive infiltrating tumor cells in the resection cavity and ventricle wall significantly influenced the prognosis of patients with glioblastoma. Aggressive surgical removal of infiltrating tumor cells may improve their prognosis.

Global transcriptome analysis identifies weight regain-induced activation of adaptive immune responses in white adipose tissue of mice

Objective:

Studies have indicated that weight regain following weight loss predisposes obese individuals to metabolic disorders; however, the molecular mechanism of this potential adverse effect of weight regain is not fully understood. Here we investigated global transcriptome changes and the immune response in mouse white adipose tissue caused by weight regain.

Design:

We established a diet switch protocol to compare the effects of weight regain with those of weight gain without precedent weight loss, weight loss maintenance and chow diet. We conducted a time course analysis of global transcriptome changes in gonadal white adipose tissue (gWAT) during the weight fluctuation. Co-expression network analysis was used to identify functional modules associated with the weigh regain phenotype. Immune cell populations in gWAT were characterized by flow-cytometric immunophenotyping. Metabolic phenotypes were monitored by histological analysis of adipose tissue and liver, and blood-chemistry and body weight/composition analyses.

Results:

In total, 952 genes were differentially expressed in the gWAT in the weight regain vs the weight gain group. Upregulated genes were associated with immune response and leukocyte activation. Co-expression network analysis showed that genes involved in major histocompatibility complex I and II-mediated antigen presentation and T-cell activation function were upregulated. Consistent with the transcriptome analysis results, flow cytometry demonstrated significant increases in subsets of T cells and proinflammatory M1 macrophages in the gWAT in the weight regain as compared to the weight gain group. In addition, upregulation of adaptive immune responses was associated with high incidence of adipocyte death and upregulation of high mobility group box 1, a well-known component of damage-associated molecular patterns.

Conclusions:

Our global transcriptome analysis identified weight regain-induced activation of adaptive immune responses in mouse white adipose tissue. Results suggest that activation of adipocyte death-associated adaptive immunity in adipose tissue may contribute to unfavorable metabolic effects of weight regain following weight loss.

Pathologic findings in patients who underwent robot-assisted radical prostatectomy following active surveillance: a prospective study in a single center

AIM

Active surveillance is the recommended treatment of option for men with very low-risk prostate cancer. In this study, the clinicopathological results of patients who were initially treated with active surveillance and subsequently underwent robot-assisted radical prostatectomy during follow-up are described.

METHODS

A prospective cohort of 106 men enrolled in active surveillance was reviewed. Pathologic specimens for patients who ultimately underwent robot-assisted radical prostatectomy for progression or personal preference were analyzed.

RESULTS

After exclusion of 14 patients who were lost to follow-up or with incomplete data collection, 92 men were included in the present analyses. Median follow-up was 27.6 months (range 3.3 to 193.1). Twenty-nine patients underwent robot-assisted radical prostatectomy. Progression occurred in 32 patients (34.8%), of which 23 men elected to undergo surgery. Robot-assisted radical prostatectomy was performed in 6 additional patients who chose definitive intervention due to anxiety. Pathologic analyses revealed organ-confined disease in 24 patients (82.8%), and Gleason score was ≥ 7 in nine (31%). Fourteen (48.3%) specimens were identified as having an advanced disease (Gleason score ≥ 7 and/or T3). In comparison to the patients with low-risk disease post-operatively (Gleason score <7 and T2), patients with advanced disease had significantly higher PSA density level and lower prostate volume.

CONCLUSION

In this prospective active surveillance cohort, the progression rate was 34.8% over the follow-up period of 27.6 months. In specimens of patients who underwent robot-assisted radical prostatectomy, 48.3% displayed advanced pathologic features. Therefore we recommend that patients considering active surveillance should be counseled on risk of advanced disease as a possible hazard.

Factors affecting the restaging accuracy of magnetic resonance imaging after preoperative chemoradiation in patients with rectal cancer

PURPOSES

We evaluated patient or tumor factors associated with the preoperative restaging accuracy of magnetic resonance imaging (MRI) for determining T and N stages as well as circumferential resection margin (CRM) involvement after chemoradiation (CRT) in patients with locally advanced rectal cancer.

METHODS

Seventy-seven patients with rectal cancer that were treated with preoperative CRT (50.4 Gy) followed by radical resection were included. Post-CRT MRI was performed approximately 4 weeks after preoperative CRT.

RESULTS

The median tumor distance from the anal verge was 6 cm, 48 (62%) of which were anterior and 29 (38%) posterior. The median tumor diameter was 3 cm. A stage-by-stage comparison showed that correct staging occurred in 62%, 43%, and 86% of patients for T staging, N staging, and CRM prediction, respectively. Shorter distance to the anal verge (<5 cm), smaller tumor diameter (<1 cm), and anterior tumor location were associated with incorrect T staging. There were no significant variables in terms of N staging accuracy. Shorter tumor distance and anterior tumor location were associated with incorrect CRM prediction.

CONCLUSIONS

Our findings suggest that specific tumor factors such as small, distal, or anterior rectal tumors are closely associated with the accuracy of MRI after preoperative CRT.

Waveform analysis of tremor may help to differentiate Parkinson's disease from drug-induced parkinsonism

In this study, we analyzed the waveform characteristics of resting tremor by accelerometer recordings in patients with drug-induced parkinsonism (DIP) and Parkinson's disease (PD). We prospectively recruited 12 patients with tremulous PD and 12 patients with DIP presenting with resting tremor. Tremor was recorded from the more affected side and was recorded twice for a 60 s period in each patient. Peak frequency, amplitude and all harmonic peaks were obtained, and the asymmetry of the decay of the autocorrelation function, third momentum and time-reversal invariance were also computed using a mathematical algorithm. Among the parameters used in the waveform analysis, the harmonic ratio, time-reversal invariance and asymmetric decay of the autocorrelation function were different between PD and DIP at a statistically significant level (all p < 0.01). The total harmonic peak power and third momentum in the time series were not significantly different. The clinical characteristics of DIP patients may be similar to those of PD patients in some cases, which makes the clinical differentiation between DIP and PD challenging. Our study shows that the identification of parameters reflecting waveform asymmetry might be helpful in differentiating between DIP and PD.

Diagnostic performance of multidetector CT for acute cholangitis: evaluation of a CT scoring method

OBJECTIVE

The aim of this study was to retrospectively assess the diagnostic performance of multidetector CT (MDCT) for the diagnosis of acute cholangitis using a new scoring method.

METHODS

Of 80 patients with suspected biliary disease who underwent biphasic CT and endoscopic retrograde cholangiography, 39 were diagnosed as having acute cholangitis (Group 1) and 41 patients were classified as suspected biliary disease (Group 2). 100 age-matched patients without evidence of biliary disease were selected randomly as a control group (Group 3). Each patient's axial scan was scored by two independent radiologists for the extent of transient hepatic attenuation difference, the presence of biliary dilatation and identification of a biliary obstructive lesion. The difference in the scores among the three groups was evaluated and the optimal cut-off score for the diagnosis of acute cholangitis was determined. Interobserver agreement was also evaluated.

RESULTS

The total scores (mean ± standard deviation) for Groups 1, 2 and 3 were 7.0 ± 2.0, 4.4 ± 2.4 and 0.9 ± 1.2, respectively, for Reviewer 1 and 7.2 ± 2.7 and 0.7 ± 1.1, respectively, for Reviewer 2. Significant differences were found for the subscores and the total scores among the three groups (p < 0.001). Using a cut-off score of ≥ 5, the sensitivity and specificity for diagnosing acute cholangitis were 84.6% and 83.7%, respectively, for Reviewer 1 and 89.7% and 83.7%, respectively, for Reviewer 2. Agreement for the subscores between readers was good to excellent (κ = 0.74-0.86).

CONCLUSION

Based on dynamic MDCT and the described CT scoring method, the diagnosis of acute choangitis can be made with high sensitivity and specificity.

The hOGG1 mutant genotype is associated with prostate cancer susceptibility and aggressive clinicopathological characteristics in the Korean population

BACKGROUND

The gene encoding human 8-oxoguanine glycosylase 1 (hOGG1) is involved in DNA base excision repair from oxidatively damaged DNA. A case-control study was conducted to evaluate the correlation between the susceptibility and clinicopathological outcomes of prostate cancer (CaP) and hOGG1 genotype.

PATIENTS AND METHODS

Subjects were recruited from 266 CaP patients and 266 age-matched benign prostatic hyperplasia patients. The hOGG1 codon 326 genotype was determined by peptide nucleic acid-mediated PCR clamping and compared with Gleason score and tumor stage.

RESULTS

The Cys allele at codon 326 of hOGG1 was associated with an increased risk of CaP in comparison with the Ser allele (P = 0.005). Gleason scores of 8 or higher were observed more often in patients with the mutant genotypes Ser/Cys and Cys/Cys than in those with a wild-type genotype (P = 0.045), and the Cys/Cys homozygous genotype was associated with a significantly higher risk of metastatic disease in comparison with the Ser/Ser genotype (P = 0.017).

CONCLUSIONS

These results suggest that hOGG1 is associated with the susceptibility to CaP and its aggressive clinicopathological characteristics.

Assessment of post-stroke extrapersonal neglect using a three-dimensional immersive virtual street crossing program

OBJECTIVE

To investigate the potential of our newly developed three-dimensional immersive virtual reality (VR) program modeled on a real street crossing as an assessment tool for extrapersonal neglect in stroke patients.

METHODS

Thirty-two patients with right-hemispheric stroke (neglect group, 16; non-neglect group, 16) were enrolled. The deviation angle, reaction time, left-to-right reaction time ratio, visual and auditory cue rates, and failure rate were evaluated during missions to keep a virtual avatar safe from a traffic accident in the VR program. The line bisection test and letter cancellation test were also evaluated.

RESULTS

The deviation angle, left-to-right reaction time ratio, left visual and auditory cue rates and left failure rate in the VR program showed significant differences between the two groups (P < 0.05). Depending on the direction of approach of the virtual car, the left parameters were significantly higher than the right parameters in the neglect group (P < 0.05). In the neglect group, the line bisection test correlated significantly with the deviation angle (P < 0.05). None of the other virtual reality parameters significantly correlated with the paper and pencil tests.

CONCLUSION

Post-stroke neglect in the extrapersonal space can be easily and safely detected and measured using our three-dimensional immersive virtual street crossing program.

Binding of ATP and its derivatives to selenophosphate synthetase from Escherichia coli

Mechanistically similar selenophosphate synthetases (SPS) have been isolated from different organisms. SPS from Escherichia coli is an ATP-dependent enzyme with a C-terminal glycine-rich Walker sequence that has been assumed to take part in the first step of ATP binding. Three C-terminally truncated mutants of SPS, containing the N-terminal 238 (SPS(238)), 262 (SPS(262)), and 332 (SPS(332)) amino acids of the 348-amino-acid protein, have been extracted from cell pellets, and two of these (SPS(262) and SPS(332)) have been purified to homogeneity. SPS(238) has been obtained in a highly purified form. Binding of the fluorescent ATP-derivative TNP-ATP and Mn-ATP to the proteins was examined for all truncated mutants of SPS and a catalytically inactive C17S mutant. It has been shown that TNP-ATP can be used as a structural probe for ATP-binding sites of SPS. We observed two TNP-ATP binding sites per molecule of enzyme for wild-type SPS and SPS(332) mutant and one TNP-ATP binding site for SPS(238) mutant. The stoichiometry of Mn-ATP-binding was 2 mol of ATP per mol of protein determined with [(14)C]ATP by HPLC gel-filtration column chromatography under saturating conditions. The binding stoichiometries for SPS(332), SPS(262), and SPS(238) were 2, 1.6, and 1, respectively. The C17S mutant exhibits about one third of wild type SPS TNP-ATP-binding ability and converts 12% of ATP in the ATPase reaction to ADP in the absence of selenide. The C-terminus contributes two thirds to the TNP-ATP binding; SPS(238) likely has one ATP-binding site removed by truncation.

The effect of glass synthesis route on mechanical and physical properties of resultant glass ionomer cements

Glass ionomer cements (GICs) have potential orthopaedic applications. Solgel processing is reported as having advantages over the traditional melt-quench route for synthesizing the glass phase of GICs, including far lower processing temperatures and higher levels of glass purity and homogeneity. This work investigates a novel glass formulation, BT 101 (0.48 SiO(2)-0.36 ZnO-0.12 CaO-0.04 SrO) produced by both the melt-quench and the solgel route. The glass phase was characterised by X-ray diffraction (XRD) to determine whether the material was amorphous and differential thermal analysis (DTA) to measure the glass transition temperature (T (g)). Particle size analysis (PSA) was used to determine the mean particle size and X-ray photoelectron spectroscopy (XPS) was used to investigate the structure and composition of the glass. Both glasses, the melt-quench BT 101 and the solgel BT 101, were mixed with 50 wt% polyacrylic acid (M (w), 80,800) and water to form a GIC and the working time (T (w)) and the setting time (T (s)) of the resultant cements were then determined. The cement based on the solgel glass had a longer T (w) (78 s) as compared to the cement based on the melt derived glass (19 s). T (s) was also much longer for the cement based on the solgel (1,644 s) glass than for the cement based on the melt-derived glass (25 s). The cements based on the melt derived glass produced higher strengths in both compression (sigma(c)) and biaxial flexure (sigma(f)), where the highest strength was found to be 63 MPa in compression, at both 1 and 7 days. The differences in setting and mechanical properties can be associated to structural differences within the glass as determined by XPS which revealed the absence of Ca in the solgel system and a much greater concentration of bridging oxygens (BO) as compared to the melt-derived system.

Multiple gastrointestinal stromal tumours presenting as a haemoperitoneum in a patient with Type 1 neurofibromatosis: MDCT findings

We report multidetector row CT images of multiple gastrointestinal tumours in a patient with Type 1 neurofibromatosis who presented with haemoperitoneum. The use of CT demonstrated multiple, variably sized, ovoid, relatively well-enhancing masses in the intramural or subserosal location of the jejunum. The largest mass that showed a haemorrhagic necrosis caused haemoperitoneum. These imaging features are unique and differ from previous imaging features that have been reported in the radiological literature.

Mechanics of the passive knee joint. Part 2: interaction between the ligaments and the articular surfaces in guiding the joint motion

The aim of this study was to examine how the interaction between ligament tensions and contact forces guides the knee joint through its specific pattern of passive motion. A computer model was built based on cadaver data. The passive motion and the ligament lengthening and force patterns predicted by the model were verified with data from the literature. The contribution of each ligament and contact force was measured in terms of the rotational moment that it produced about the tibial medial plateau and the anterior-posterior (AP) force that it exerted on the tibia. The high tension of the anterior cruciate ligament (ACL) and the geometric constraints of the anterior horns of the menisci were found to be key features that stabilized the knee at full extension. The mutual effect of the cruciates was found as the reason for the screw-home mechanism at early flexion. Past 300, the AP component of contact force on the convex geometry of the lateral tibial plateau and tension of the lateral collateral ligament (LCL) were identified as elements that control the joint motion. From 60 degrees to 90 degrees, reduction in the tension of the ACL was determined as a reason for continuation of the tibial anterior translation. From 90 degrees to 120 degrees, increase in the tension of the posterior cruciate ligament and the AP component of the contact force on the convex geometry of the lateral tibial plateau pushed the tibia more anteriorly. This anterior translation was limited by the constraining effects of the ACL tension and the AP component of the contact force on the medial meniscus. The important guiding role observed for the LCL suggests that it should not be overlooked in knee models.

White matter abnormalities in drug-naïve patients with obsessive-compulsive disorder: a diffusion tensor study before and after citalopram treatment

OBJECTIVE

The aim was to investigate the white matter abnormalities of drug-naïve patients with obsessive-compulsive disorder (OCD) using diffusion tensor-imaging and the white matter changes in the patients after pharmacotherapy.

METHOD

Thirteen drug-naïve OCD patients and 13 age- and sex-matched healthy comparison subjects were examined using diffusion tensor-imaging and structural magnetic resonance imaging. Measurements were made in OCD patients before and after 12 weeks of citalopram treatment.

RESULTS

Compared with controls, the drug-naïve OCD patients showed significant increases in fractional anisotropy (FA) in the corpus callosum, the internal capsule and white matter in the area superolateral to the right caudate. The increases in FA were mostly no longer observed in patients after 12 weeks of treatment compared with controls.

CONCLUSION

Our findings suggest that white matter alterations are associated with the pathophysiology of OCD, and the abnormalities may be partly reversible with pharmacotherapy.

Evaluation of semi-interpenetrating polymer networks composed of chitosan and poloxamer for wound dressing application

We have elsewhere reported the work on the preparation of semi-interpenetrating polymer networks (SIPNs) composed of chitosan (CS) and poloxamer to improve the mechanical strength of CS sponge. This study focuses on evaluation of the CS/poloxamer SIPNs to intend for wound dressing application and the efficacy of dehydroepiandrosterone (DHEA)-loaded CS/poloxamer SIPNs in the wound model studies. The properties required for ideal wound dressing, such as equilibrium water content (EWC), water absorption (A(w)), water vapor transmission rate (WVTR), and evaporative water loss, were examined. The CS/poloxamer SIPNs were found to have a water content of 90% of their weight which could prevent the wound bed from accumulation of exudates and also have excellent water adsorption. The WVTR of CS/poloxamer SIPNs was found to be 2,508.2+/-65.7gm(-2)day(-1), indicating that the SIPNs can maintain a moist environment over wound bed in moderate to heavily exuding wound which enhances epithelial cell migration during the healing process. Also, the CS/poloxamer SIPNs in vitro assessment showed proper biodegradation and low cytotoxicity for wound dressing application. The wound healing efficacy of CS/poloxamer SIPNs as a wound dressing was evaluated on experimental full thickness wounds in a mouse model. It was found that the wounds covered with CS/poloxamer SIPNs or DHEA-loaded CS/poloxamer SIPNs were completely filled with new epithelium without any significant adverse reactions after 3 weeks. The results thus indicate that CS/poloxamer SIPNs could be employed in the future as potential wound dressing materials.

Regulation of adipocyte differentiation by PEGylated all-trans retinoic acid: reduced cytotoxicity and attenuated lipid accumulation

Obesity is major risk factor for many disorders, including diabetes, hypertension and heart disease. Unfortunately, there is a dearth of therapeutic agents available to clinicians for the treatment of obesity. The principal aim of this study was to investigate whether PEGylated all-trans retinoic acid (PRA) can have favorable stability and biological activity in 3T3-L1 preadipocytes as an antiobesity drug. Here, we found that PRA inhibits the process of adipogenesis, including survival of adipocytes and differentiation to mature adipocytes. The results showed that RA nanoparticles (NPs) were prepared by PEGylation; below 200 nm, PRA-NPs were obtained. Moreover, PRA decreased glycerol-3-phosphate dehydrogenase activity in 3T3-L1 preadipocytes by acting with major adipocyte marker proteins such as PPARgamma2, C/EBPalpha and aP2 modulators. Apoptosis, in addition, increased as the level of RA increased from 10 to 20 microM, whereas PRA reduced apoptosis with increasing concentrations. Our data suggest that PRA-NP has potential as an antiobesity drug carrier due to its small particle size and PEGylated core-shell structure. In addition, our results suggest that PRA inhibits the process of adipogenesis and may be developed to treat obesity. Based on these results, PRA is suitable for adipocyte studies, and an enhanced effect of PRA with adipocyte differentiation offers a challenging approach for pharmaceutical applications.

Mechanics of the passive knee joint. Part 1: The role of the tibial articular surfaces in guiding the passive motion

The motion of the unloaded knee is associated with tibial internal rotation and femoral posterior translation. Although it is known that the passive motion is the result of the interaction between the articular surfaces and the ligaments, the mechanism through which the particular pattern of motion is guided is not completely understood. The goal of this study was to focus on the tibial geometry and to identify the roles that its geometric features have in guiding the passive knee motion. The method used in this study simplified the geometry of the tibial plateaux and the menisci into basic features that could be eliminated individually. The generated tibial geometry was implemented in a computer model to simulate the passive motion. Different parts of the geometry were eliminated individually and the comparison between the simulation results was used to identify the role that each part of the geometry had in guiding the passive motion. The medial meniscus was found as the feature that promoted the tibial internal rotation and restrained the femoral posterior translation. The lateral meniscus and the medial aspect of the tibial eminence, on the other hand, were found as the elements that confined the tibial internal rotation.

An Efficient Adaptive Feedback cancellation using by Independent component analysis for hearing aids

In this paper, we proposed a feedback cancellation algorithm based on independent component analysis (ICA) for digital hearing aids. In conventional adaptive feedback cancelling systems, the normalized least mean squares (NLMS) algorithm used to reduce acoustic feedback in which hearing aids occurs, generally at high gains. But primary input signal depend on the acoustic feedback signal in higher-order statistics, proposed algorithm was better acoustic feedback cancelling performance than the conventional NLMS algorithm when the input signal has a Laplacian distribution with high-order processing in real-time simulation of TMS320C 6711 DSK.

Down-regulation of PPARgamma2-induced adipogenesis by PEGylated conjugated linoleic acid as the pro-drug: Attenuation of lipid accumulation and reduction of apoptosis

This study is designed to evaluate whether the PEGylated conjugated linoleic acid (PCLA) as the pro-drug can have favorable stability, bioavailability, and anti-adipogenic activity in 3T3-L1 cells for anti-obesity when compared with conjugated linoleic acid (CLA) itself. The CLA was simply coupled to poly(ethylene glycol) (PEG) at the melting state without solvents or catalysts through ester linkages between the carboxylic group of CLA and the hydroxyl group of PEG. To confirm of PCLA as the pro-drug, CLA release from PCLA was investigated by using high-performance liquid chromatographic (HPLC), showing that CLA release from PCLA was almost 90% in a nearly continuous fashion over the next 75h. Apoptosis was promoted by both CLA- and PCLA-treatments with increasing concentrations. However, the level of cell apoptosis induced by PCLA was lower than that induced by CLA owing to the biocompatible and hydrophilic properties of PEG. Moreover, the PCLA decreased glycerol-3-phosphate dehydrogenase (GPDH) activity in 3T3-L1 cells by acting upon major adipocyte marker proteins such as PPARgamma2, C/EBPalpha, and aP2 modulators. Furthermore, either CLA or PCLA stimulated basal, but not isoproterenol-sensitive, lipolysis in our cell model, suggesting that both CLA and PCLA may stimulate lipolysis via hormone sensitive lipase (HSL)-independent mechanisms. These results suggest that the PCLA may prove to be a stable pro-drug to control the deposition of fat in the human body, and that the anti-adipogenic effect of the PCLA on 3T3-L1 cells will offer a challenging approach for anti-obesity.

Pancreatic carcinoid tumor with obstructive pancreatitis: multislice helical CT appearance: case report

Carcinoid tumor of the pancreas is rare. Moreover, obstructive pancreatitis secondary to a pancreatic carcinoid tumor is extremely rare. We report a case of pancreatic carcinoid tumor in a 50-year-old male who presented with pancreatitis. On multislice helical computed tomography, the main pancreatic duct was obstructed by a small round tumor, and the main pancreatic duct proximal to the tumor was dilated. The correlation between the main pancreatic duct and the tumor was well depicted on minimum intensity projection image. This is the first report of multislice helical computed tomorgraphic and minimum intensity projection image findings of a pancreatic carcinoid tumor presenting with pancreatitis.

Small cell carcinoma of the colon: barium study and CT findings

Extrapulmonary small cell carcinoma is a rare neoplasm. It is an aggressive malignant tumour characterized by rapid local progression and early metastasis. We report a case of small cell carcinoma arising in the transverse colon in a 34-year-old man who presented with epigastric pain. On CT, a poorly enhancing bulky mass encircling the transverse colon with extensive regional lymph node metastases was observed. A segmental annular narrowing with thick interhaustral folds of the transverse colon was found by barium enema examination. This is the first report of barium study and CT findings of extrapulmonary small cell carcinoma of the colon.

Neuronavigation-Guided Endoscopic Surgery for Pineal Tumors with Hydrocephalus

We have applied the neuronavigation system to endoscopic biopsy and third ventriculostomy in the management of patients with a pineal tumor with hydrocephalus. With the guidance of neuronavigation, the two optimal sites of burr hole and trajectories were planned preoperatively, and the advancing endoscopic device was monitored in real time during the procedure. In our five patients, the diameters of the tumors were 2-3 cm, and the mean systemic accuracy of registration with neuronavigation was 1.2 mm. The biopsy and third ventriculostomy were performed successfully via the respective optimal burr hole and the trajectory determined using preoperative neuronavigation. There were no procedure-related complications, and none of the patients needed another procedure for CSF diversion during the follow-up periods. We present our technique which includes the application of the neuronavigation system to the biopsy and third ventriculostomy in pineal tumor with associated hydrocephalus. This technique can be performed using a simple rigid endoscope via the determined optimal entries and trajectories. The optimal preoperative planning and the intraoperative guidance by neuronavigation are thought to be able to give more chances to minimize the brain injury related to movements or deviation of endoscopic device.

Web-based remote monitoring of infant incubators in the ICU

A web-based real-time operating, management, and monitoring system for checking temperature and humidity within infant incubators using the Intranet has been developed and installed in the infant Intensive Care Unit (ICU). We have created a pilot system which has a temperature and humidity sensor and a measuring module in each incubator, which is connected to a web-server board via an RS485 port. The system transmits signals using standard web-based TCP/IP so that users can access the system from any Internet-connected personal computer in the hospital. Using this method, the system gathers temperature and humidity data transmitted from the measuring modules via the RS485 port on the web-server board and creates a web document containing these data. The system manager can maintain centralized supervisory monitoring of the situations in all incubators while sitting within the infant ICU at a work space equipped with a personal computer. The system can be set to monitor unusual circumstances and to emit an alarm signal expressed as a sound or a light on a measuring module connected to the related incubator. If the system is configured with a large number of incubators connected to a centralized supervisory monitoring station, it will improve convenience and assure meaningful improvement in response to incidents that require intervention.

Three-dimensional reconstructed images using multidetector computed tomography in evaluation of the biliary tract

The recent development of multidetector computed tomography (MDCT) and the parallel escalation in the capabilities of the workstation allow the use of high-quality multiplanar and three-dimensional reconstruction images. As a noninvasive technique, MDCT dedicated to the biliary tract represents an alternative to magnetic resonance cholangiography. The usefulness of three-dimensional reconstructed images using MDCT in evaluating biliary tract abnormality is illustrated.

Development of a virtual speaking simulator using Image Based Rendering

The fear of speaking is often cited as the world's most common social phobia. The rapid growth of computer technology has enabled the use of virtual reality (VR) for the treatment of the fear of public speaking. There are two techniques for building virtual environments for the treatment of this fear: a model-based and a movie-based method. Both methods have the weakness that they are unrealistic and not controllable individually. To understand these disadvantages, this paper presents a virtual environment produced with Image Based Rendering (IBR) and a chroma-key simultaneously. IBR enables the creation of realistic virtual environments where the images are stitched panoramically with the photos taken from a digital camera. And the use of chroma-keys puts virtual audience members under individual control in the environment. In addition, real time capture technique is used in constructing the virtual environments enabling spoken interaction between the subject and a therapist or another subject.

Blocking of acidosis-mediated apoptosis by a reduction of lactate dehydrogenase activity through antisense mRNA expression

Lactic acid produced from the cells is a potential cause of extra- and intracellular acidification. Due to scarce technical tools, lactic acid that leads to acidification could not be reduced and direct evidence of the relationship between metabolic lactate and apoptosis has not yet been elucidated. In this study, we designed a cellular pH regulation system in CHO cells by a reduction of lactate dehydrogenase (LDH) activity through LDH antisense mRNA expression. This inhibited lactate production and, therefore, acidification of the cytosol. Under HCO3(-)-buffered growth conditions, both the parent CHO cells and the engineered CHO cells maintained their extracellular pH and intracellular pH fairly well. However, upon acidification of the cytosol, only the parent CHO cells underwent apoptosis under HCO3(-)-free conditions. In fact, we observed a number of apoptosis-related events only in control cells, including mitochondrial dysfunction, cytochrome c release, and an increase in caspase-3 enzymatic activity.

Preoperative plasma levels of transforming growth factor beta(1) strongly predict clinical outcome in patients with bladder carcinoma

BACKGROUND

Elevated local and circulating levels of transforming growth factor (TGF)-beta(1) have been associated with cancer invasion, progression, and metastasis. The authors tested the hypothesis that preoperative plasma TGF-beta(1) levels would independently predict cancer stage and prognosis in patients with transitional cell carcinoma (TCC) of the urinary bladder.

METHODS

The study group consisted of 51 patients who underwent radical cystectomy for muscle-invasive or intravesical immuno- and/or chemotherapy refractory Tis, Ta, or T1 TCC (median follow-up, 45.7 months). Preoperative plasma levels of TGF-beta(1) were measured and correlated with pathologic features and clinical outcome. Transforming growth factor-beta(1) levels also were measured in 44 healthy men without any cancer.

RESULTS

The mean preoperative plasma TGF-beta(1) level in patients who eventually developed metastases to distant (11.9 +/- 0.9 ng/mL) or regional (9.6 +/- 2.4 ng/mL) lymph nodes was significantly higher than that in patients with nonmetastatic muscle-invasive TCC (5.4 +/- 1.1 ng/mL), which, in turn, was significantly higher than that in patients with nonmetastatic Tis, Ta, or T1 TCC (4.5 +/- 1.2 ng/mL) and healthy subjects (4.5 +/- 1.2 ng/mL; P < 0.001). Preoperative plasma TGF-beta(1) level was an independent predictor of lymphovascular invasion (P = 0.002), metastases to lymph nodes (P = 0.030), disease recurrence (P = 0.009), and disease specific survival (P = 0.015). In a subgroup of patients with muscle-invasive TCC, TGF-beta(1) level was associated with disease recurrence (P = 0.005) and death from bladder carcinoma (P = 0.001).

CONCLUSIONS

The authors confirm that plasma TGF-beta(1) levels are elevated in patients with muscle-invasive TCC before cystectomy. Transforming growth factor-beta(1) levels are highest in patients with bladder carcinoma metastatic to lymph nodes and are a strong independent predictor of disease recurrence and disease specific mortality.

Grey matter abnormalities in obsessive-compulsive disorder: statistical parametric mapping of segmented magnetic resonance images

BACKGROUND

Although a number of functional imaging studies are in agreement in suggesting orbitofrontal and subcortical hyperfunction in the pathophysiology of obsessive-compulsive disorder (OCD), the structural findings have been contradictory.

AIMS

To investigate grey matter abnormalities in patients with OCD by employing a novel voxel-based analysis of magnetic resonance images.

METHOD

Statistical parametric mapping was utilised to compare segmented grey matter images from 25 patients with OCD with those from 25 matched controls.

RESULTS

Increased regional grey matter density was found in multiple cortical areas, including the left orbitofrontal cortex, and in subcortical areas, including the thalamus. On the other hand, regions of reduction were confined to posterior parts of the brain, such as the left cuneus and the left cerebellum.

CONCLUSIONS

Increased grey matter density of frontal-subcortical circuits, consonant with the hypermetabolic findings from functional imaging studies, seems to exist in patients with OCD, and cerebellar dysfunction may be involved in the pathophysiology of OCD.

Predictive value of expression of transforming growth factor-beta(1) and its receptors in transitional cell carcinoma of the urinary bladder

BACKGROUND

The purpose of this study was to describe the expression patterns of transforming growth factor (TGF)-beta(1) and its receptors in transitional cell carcinoma (TCC) of the bladder, to investigate the relation between the TGF-beta(1) and its receptors, and to determine whether altered expression of TGF-beta or its receptors is associated with disease progression and survival in patients with TCC of the bladder.

METHODS

Immunohistochemical staining for TGF-beta(1) and its receptors I and II was conducted on formalin fixed paraffin embedded archival cystectomy specimens of 80 patients with bladder TCC. Immunoreactivity was categorized as either positive or negative in a blinded fashion.

RESULTS

Expression of TGF-beta(1), TGF-beta-RI, and TGF-beta-RII was altered in 51 (64%), 34 (43%), and 38 (48%) specimens, respectively. Sixty (75%) specimens had altered expression of at least 1 of the 3 TGF-betas, and 26 (33%) had altered expression of all 3. Expression of the three TGF-betas was highly concordant (P < 0.018). Loss of expression of TGF-beta-RI or TGF-beta-RII was associated with invasive tumor stage (P < 0.001), high grade (P < 0.006), and lymphovascular invasion (P < 0.030). Overexpression of TGF-beta(1) was associated with invasive tumor stage only (P = 0.024). With a median follow-up of 101 months, TGF-beta-RI was an independent predictor of both disease progression (P = 0.007) and disease specific survival (P = 0.006) whereas TGF-beta(1) was an independent predictor of disease progression only (P = 0.050). Transforming growth factor-beta-RII was not independently associated with either disease progression or survival.

CONCLUSIONS

Altered expression of TGF-beta(1) and its receptors is common in TCC of the bladder. Overexpression of TGF-beta(1) is associated with the loss of expression of its receptors. Transforming growth factor-beta(1) and TGF-beta-RI are independently associated with clinical outcome in patients with bladder TCC treated by radical cystectomy.

Heterozygous mice for the transforming growth factor-beta type II receptor gene have increased susceptibility to hepatocellular carcinogenesis

The transforming growth factor-beta (TGF-beta) receptor complex and its downstream signaling intermediates constitute a tumor suppressor pathway. In many cancers, expression of TGF-beta type II receptor (TbetaR-II) is markedly decreased. In the present study, we show that the hepatocytes isolated from 15-day-old, but not 9-month-old, mice heterozygous for the deletion of the TbetaR-II gene are slightly less sensitive to the growth-inhibitory effect of TGF-beta when compared with wild-type littermates of same age. In addition, the proliferation index of hepatocytes as indicated by bromodeoxyuridine incorporation is mildly increased in the heterozygous mice. These subtle changes in cellular phenotype did not result in either gross or microscopic abnormality of the liver. The treatment of these mice with the chemical carcinogen, diethylnitrosamine, results in a significantly enhanced tumorigenesis in the liver when compared with the wild-type littermates. Our results demonstrate the gene-dosage effect of TbetaR-II and indicate that the reduced expression of TbetaR-II in mice increases susceptibility to tumorigenesis in the liver.

Preoperative plasma levels of transforming growth factor beta(1) (TGF-beta(1)) strongly predict progression in patients undergoing radical prostatectomy

PURPOSE

Elevated local and circulating levels of transforming growth factor beta(1) (TGF-beta(1)) have been associated with prostate cancer invasion and metastasis. We tested the hypothesis that preoperative plasma TGF-beta(1) levels would independently predict cancer stage and prognosis in patients who undergo radical prostatectomy.

PATIENTS AND METHODS

The study group consisted of 120 consecutive patients who underwent radical prostatectomy for clinically localized prostate cancer (median follow-up, 53.8 months). Preoperative plasma levels of TGF-beta(1) were measured and correlated with pathologic parameters and clinical outcomes. TGF-beta(1) levels also were measured in 44 healthy men without cancer, in 19 men with prostate cancer metastatic to regional lymph nodes, and in 10 men with prostate cancer metastatic to bone.

RESULTS

Plasma TGF-beta(1) levels in patients with lymph node metastases (14.2 +/- 2.6 ng/mL) and bone metastases (15.5 +/- 2.4 ng/mL) were higher than those in radical prostatectomy patients (5.2 +/- 1.3 ng/mL) and healthy subjects (4.5 +/- 1.2 ng/mL) (P <.001). In a preoperative analysis, preoperative plasma TGF-beta(1) level and biopsy Gleason sum both were predictors of organ-confined disease (P =.006 and P =.006, respectively) and PSA progression (P <.001 and P =.021, respectively). In a postoperative multivariate analysis, preoperative plasma TGF-beta(1) level, pathologic Gleason sum, and surgical margin status were predictors of PSA progression (P =.020,P =.020, and P =.022, respectively). In patients who progressed, preoperative plasma TGF-beta(1) levels were higher in those with presumed distant compared with local-only failure (P =.019).

CONCLUSION

Plasma TGF-beta(1) levels are markedly elevated in men with prostate cancer metastatic to regional lymph nodes and bone. In men without clinical or pathologic evidence of metastases, the preoperative plasma TGF-beta(1) level is a strong predictor of biochemical progression after surgery, presumably because of an association with occult metastatic disease present at the time of radical prostatectomy.

Laparoscopic nephrectomy for renal cell carcinoma

Since the first reported case of laparoscopic nephrectomy by Clayman et al. in 1991, laparoscopy is gaining acceptance as a viable alternative to open surgery for renal cell carcinoma. The benefits of laparoscopy include improved quality of life and lower incidence of perioperative morbidity. The perceived risks of laparoscopic nephrectomy for renal cell carcinoma include port-site metastasis, increased operative time, and the concern for inadequate surgical resection. The preliminary data concerning laparoscopy in renal cell carcinoma, however, indicate that rates of tumor recurrence are equivalent to open surgery while resulting in better cosmesis, decreased level of perioperative analgesic use, and decreased length of time to full convalescence.

Changes in dead space/tidal volume ratio and pulmonary mechanics after surfactant replacement therapy in respiratory distress syndrome of the newborn infants

This study was performed to elucidate the mechanism of improved oxygenation after surfactant replacement therapy in respiratory distress syndrome (RDS) of the newborn infants. In 26 newborns with RDS, end tidal-CO2 tension (PetCO2), arterial blood gas analysis and pulmonary function tests were measured at baseline, 30 min, 2 hr and 6 hr after surfactant administration. The changes in dead space/tidal volume ratio (VD/VT ratio=(PaCO2-PetCO2)/PaCO2), oxygenation index and arterial-alveolar partial pressure difference for oxygen ((A-a)DO2) were elucidated and correlated with pulmonary mechanics. Oxygenation index and (A-a)DO2 improved, and VD/VT ratio decreased progressively after surfactant administration, becoming significantly different from the baseline at 30 min and thereafter with administration of surfactant. Pulmonary mechanics did not change significantly during the observation period. VD/VT ratio showed close correlation with OI and (A-a)DO2, but not with pulmonary mechanics. These results suggest that decreased physiologic dead space resulting from the recruitment of atelectatic alveoli rather than improvement in pulmonary mechanics is primarily responsible for the improved oxygenation after surfactant therapy in the RDS of newborn.

Dyspareunia: an unusual presentation of leiomyoma of the bladder

Leiomyoma is a rare, benign tumor of the bladder. It frequently has an unusual presentation and its treatment options remain controversial. We describe a case of a leiomyoma of the bladder in a young female whose chief complaint was dyspareunia, and we review the management options.

Measurement of femoral neck anteversion in 3D. Part 1: 3D imaging method

Femoral neck anteversion is the torsion of the femoral head with reference to the distal femur. Conventional methods that use cross-sectional computed tomography (CT), magnetic resonance or ultrasound images to estimate femoral anteversion have met with several problems owing to the complex, three-dimensional (3D) structure of the femur. These problems include not only the difficulty of defining the direction of the femoral neck axis and condylar line but also the dependency upon patient positioning. In particular, the femoral neck axis, the direction of the femoral head, known as the major source of error, is difficult to determine from either a single or several two-dimensional (2D) cross-sectional images. A new method has been devised for the measurement of femoral anteversion using the 3D imaging technique. 3D reconstructed CT images from the femoral head and trochanter to the distal femur are used to measure the anteversion. It is necessary to remove the soft tissue from the CT images and extract just the bone part. Then, the femoral anteversion is measured from a computer-rendered femur image. The 3D imaging method is compared with both the conventional 2D method and the physical method using 20 dried femurs. For the physical method, which is used as a reference value, a special apparatus is devised. The average difference between the results of the physical method and those of the 2D CT method is 5.33 degrees. The average difference between the results of the physical method and those of the 3D imaging method is 0.45 degrees. Seventy-four patients, who suffer from toe-in-gait disease, are tested to compare the 3D imaging method with the conventional 2D CT method. The average difference between the 2D and 3D methods is 8.6 degrees, and the standard is 7.43 degrees. This method provides a very accurate and reliable measurement of femoral anteversion, as it is virtually equivalent to the direct measurement of bisected dried femur in vitro.

Measurement of femoral neck anteversion in 3D. Part 2: 3D modelling method

Femoral neck anteversion is the torsion of the femoral head with reference to the distal femur. Conventional methods that use cross-sectional computed tomography (CT), magnetic resonance or ultrasound images to estimate femoral anteversion have met with several problems owing to the complex three-dimensional (3D) structure of the femur. A 3D imaging method has been developed that virtually measures femoral anteversion on the 3D computer space with continuous CT slices; this 3D method provides more accurate and reliable results than conventional 2D CT measurements. A 3D modelling method is devised for the measurement of femoral neck anteversion. This method has advantages over the 3D imaging method, such as shorter processing time, reduced number of slices and an objective result compared with the 3D imaging method. The results of the 3D modelling method are compared with the conventional CT methods (2D CT method and 3D imaging method) using 20 dried femurs.

Ammonia removal using hepatoma cells in mammalian cell cultures

It was examined whether hepatocyte cell lines can be used for ammonia removal in mammalian cell cultures. It was found that there exists a critical ammonium concentration level for each hepatocyte cell to remove ammonia. Among the cells tested in this work, primary hepatocytes showed the strongest ammonia removal capability if ammonium concentration is higher than the critical level. However, primary hepatocytes lost the liver function gradually and finally died after 2-3 weeks. Because of this limitation, primary hepatocytes were not appropriate to be used for ammonia removal in long-term cultures. Hep G2 cells, which are immortal, also showed a strong ammonia removal activity. The ammonia removal activity of Hep G2 cells depended on the concentration of ammonium in the medium, as in the case of primary hepatocytes. However, urea could not be detected in the course of ammonia removal by Hep G2 cells. Instead of urea, Hep G2 cells secreted glutamine into the culture medium. The capacity for ammonia removal was higher in the absence than in the presence of glutamine. Thus we checked the activity of glutamine synthetase in the Hep G2 cells. The level of glutamine synthetase activity increased with the addition of ammonium chloride. This result accounts for the ammonium concentration dependency of Hep G2 cells in ammonia removal and glutamine synthesis. Furthermore Hep G2 cells could grow well in the absence of glutamine, which was necessarily required in mammalian cell cultures. These results prove that glutamine formation serves as the primary mechanism of detoxifying ammonia in hepatocyte cell lines as expected. In addition, it was demonstrated that ammonium level could be reduced 38% and that erythropoietin production increased 2-fold in the mixed culture of Hep G2 and recombinant CHO cells.

Expression of carbamoyl phosphate synthetase I and ornithine transcarbamoylase genes in Chinese hamster ovary dhfr-cells decreases accumulation of ammonium ion in culture media

Ammonium ion accumulation in mammalian cell culture media causes toxicity which inhibits cell growth and productivity. To reduce the level of the accumulated ammonium ion, carbamoyl phosphate synthetase I (CPS I) and ornithine transcarbamoylase (OTC) were used, which catalyze the first and second steps of the urea cycle in the liver. To examine the effects of overexpressed CPS I and OTC genes on the concentration of the ammonium ion in culture media, the two genes were introduced into Chinese hamster ovary (CHO) dhfr-cells. The CPS I expressing cell lines (CPS I-CHO) and both CPS I and OTC expressing cell lines (CPS I/OTC-CHO) were confirmed at the mRNA level and analyzed in terms of the cell growth and the accumulation of ammonium ion in culture media. The accumulation of ammonium ion was approximately 25-33% less in CPS I/OTC-CHO than in either CPS I-CHO or the vector-control cell lines. Interestingly however, the cell growth was approximately 15-30% faster in both CPS I-CHO and CPS I/OTC-CHO than in the control cell lines. Forced expression of urea cycle enzymes in the CHO cells revealed that both the expression of CPS I and OTC can reduce the accumulation of ammonium ion in the culture media.

Expression of bone morphogenetic protein receptors type-IA, -IB and -II correlates with tumor grade in human prostate cancer tissues

Bone morphogenetic proteins (BMPs) are potential regulators of prostate cancer cell growth and metastasis that signal through an interaction with BMP membrane receptors (BMPRs) type I and type II. In the present study, Western blot and immunohistochemical analysis of BMPRs were carried out in benign and malignant human prostate tissues to explain the loss of BMP response in human prostate cancer cells. The results demonstrated that the benign prostate specimens expressed high levels of all three BMPRs. In normal prostate, BMPRs were localized predominantly to epithelial cells. Among prostate cancer specimens, well-differentiated cancers were positive for the expression of BMPR-II, BMPR-IA, and BMPR-IB, for the most part. In contrast, only 1 of 10 poorly differentiated prostate cancer cases was positive for each of the three BMPRs (P < 0.005 for all three receptors). Taken together, these results indicate that human prostate cancer cells frequently exhibit loss of expression of BMPRs and suggest that loss of BMPRs may play an important role during the progression of prostate cancer.

Absence of proximal duct apoptosis in the ventral prostate of transgenic mice carrying the C3(1)-TGF-beta type II dominant negative receptor

BACKGROUND

Prostatic epithelial cells are sensitive to the inhibitory effects of TGF-beta. However, TGF-beta signaling in the prostate is dependent on androgenic status. Under the in vivo conditions, it is difficult to dissociate the effect of TGF-beta from that of androgen on the prostate.

METHODS

The objective of the present study was to create and verify a transgenic mouse system in which epithelial cells of the ventral prostate are insensitive to the actions of TGF-beta. By using a modified prostate-specific promoter, C3(1), the TGF-beta dominant negative receptor is only expressed in the epithelial cells of the ventral prostate, and these cells are resistant to TGF-beta. Morphology of transgenic animal prostates was compared to wild-type animal prostates by immunohistochemistry and microscopy.

RESULTS

The prostate of transgenic mice exhibited an abnormal morphology with multiple layers of epithelial cells lining the proximal ducts, in contrast to the simple cuboidal monolayer of cells seen in the normal prostate. This observation was accompanied by a loss of apoptosis in this region, as seen by TUNEL assay. There was no significant difference in serum levels of testosterone between the wild-type and transgenic animals.

CONCLUSIONS

These results demonstrated that a loss of sensitivity to TGF-beta results in the accumulation of multiple layers of epithelial cells in the proximal region of the ventral prostate. This abnormal growth illustrates that TGF-beta plays an important role in regulating prostate growth. The current transgenic system can be used as an experimental model to study the functional role of TGF-beta in prostatic growth and function.

Selenite negatively regulates caspase-3 through a redox mechanism

Selenium, an essential biological trace element, exerts its modulatory effects in a variety of cellular events including cell survival and death. In our study we observed that selenite protects HEK293 cells from cell death induced by ultraviolet B radiation (UVB). Exposure of HEK293 cells to UVB radiation resulted in the activation of caspase-3-like protease activity, and pretreatment of the cells with z-DEVD-fmk (N-benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone), a caspase-3 inhibitor, prevented UVB-induced cell death. Interestingly, enzymatic activity of caspase-3-like protease in cell lysates of UVB-exposed cells was repressed in vitro by the presence of selenite. Selenite also inhibited the in vitro activity of purified recombinant caspase-3 in cleaving Ac-DEVD-pNA (N-acetyl-Asp-Glu-Asp-p-nitroanilide) or ICAD(L) (inhibitor of a caspase-activated deoxyribonuclease) and in the induction of DNA fragmentation. The inhibitory action of selenite on a recombinant active caspase-3 could be reversed by sulfhydryl reducing agents, such as dithiothreitol and beta-mercaptoethanol. Furthermore, pretreatment of cells with selenite suppressed the stimulation of the caspase-3-like protease activity in UVB-exposed cells, whereas dithiothreitol and beta-mercaptoethanol reversed this suppression of the enzymatic activity. Taken together, our data suggest that selenite inhibits caspase-3-like protease activity through a redox mechanism and that inhibition of caspase-3-like protease activity may be the mechanism by which selenite exerts its protective effect against UVB-induced cell death.

Transfer RNA identity change in anticodon variants of E. coli tRNA(Phe) in vivo

The anticodon sequence is a major recognition element for most aminoacyl-tRNA synthetases. We investigated the in vivo effects of changing the anticodon on the aminoacylation specificity in the example of E. coli tRNA(Phe). Constructing different anticodon mutants of E. coli tRNA(Phe) by site-directed mutagenesis, we isolated 22 anticodon mutant tRNA(Phe); the anticodons corresponded to 16 amino acids and an opal stop codon. To examine whether the mutant tRNAs had changed their amino acid acceptor specificity in vivo, we tested the viability of E. coli strains containing these tRNA(Phe) genes in a medium which permitted tRNA induction. Fourteen mutant tRNA genes did not affect host viability. However, eight mutant tRNA genes were toxic to the host and prevented growth, presumably because the anticodon mutants led to translational errors. Many mutant tRNAs which did not affect host viability were not aminoacylated in vivo. Three mutant tRNAs containing anticodon sequences corresponding to lysine (UUU), methionine (CAU) and threonine (UGU) were charged with the amino acid corresponding to their anticodon, but not with phenylalanine. These three tRNAs and tRNA(Phe) are located in the same cluster in a sequence similarity dendrogram of total E. coli tRNAs. The results support the idea that such tRNAs arising from in vivo evolution are derived by anticodon change from the same ancestor tRNA.

Selenite inhibits the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) through a thiol redox mechanism

Selenium, an essential biological trace element, has been shown to modulate functions of many regulatory proteins involved in signal transduction and to affect a variety of cellular activities including cell growth, survival, and death. The molecular mechanism by which selenium exerts its action on the cellular events, however, remains unclear. In our present study, we observed that selenite suppresses both the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) and the p38 mitogen-activated protein kinase pathway in 293T cells. In contrast, selenite had little effect on the extracellular signal-regulated kinase pathway. Furthermore, selenite directly inhibited JNK/SAPK activity in vitro but not the p38 activity. The in vitro inhibition of JNK/SAPK by selenite was reversed by the addition of reducing agents such as dithiothreitol and beta-mercaptoethanol. Replacement of cysteine 116 in JNK1 by serine abolished the inhibitory effect of selenite on JNK1 activity both in vitro and in vivo. Selenite also suppressed a c-Jun-dependent luciferase reporter activity stimulated through the JNK signaling pathway. Taken together, our findings strongly suggest that selenite differentially modulates the mammalian mitogen-activated protein kinase pathways and that it can repress the JNK/SAPK signaling pathway by inhibiting JNK/SAPK through a thiol redox mechanism.

Characterization of the full-length sequences of phospholipase A2 induced during flower development

The suppression subtractive hybridization (SSH) method was used to isolate developmentally regulated genes during carnation flower maturation. Carnation flower maturation-related clones obtained by the SSH were serially assigned as CFMI (carnation flower maturation-induced) clones. Northern blot analysis showed that several CFMI clones were differentially expressed during flower development. One of the clones, CFMI-3, showed similarity to various animal secretory phospholipases A2 (PLA2). Since little is known about PLA2 gene sequence in plant species, the CFMI-3 clone was selected for further characterization by sequence analysis. Full sequence analysis reveals that the CFMI-3 contains a Ca2+ binding domain, a PLA2 active site, and 12 conserved Cys residues, which is a distinct characteristic of PLA2. Amino acid sequence alignment of CFMI-3 to various putative plant PLA2 confirmed that the CFMI-3 cDNA is the full-length putative PLA2 cDNA identified in plant species.

Characterization of the full-length sequences of phospholipase A2 induced during flower development

The suppression subtractive hybridization (SSH) method was used to isolate developmentally regulated genes during carnation flower maturation. Carnation flower maturation-related clones obtained by the SSH were serially assigned as CFMI (carnation flower maturation-induced) clones. Northern blot analysis showed that several CFMI clones were differentially expressed during flower development. One of the clones, CFMI-3, showed similarity to various animal secretory phospholipases A2 (PLA2). Since little is known about PLA2 gene sequence in plant species, the CFMI-3 clone was selected for further characterization by sequence analysis. Full sequence analysis reveals that the CFMI-3 contains a Ca2+ binding domain, a PLA2 active site, and 12 conserved Cys residues, which is a distinct characteristic of PLA2. Amino acid sequence alignment of CFMI-3 to various putative plant PLA2 confirmed that the CFMI-3 cDNA is the full-length putative PLA2 cDNA identified in plant species.

Decreased expression of transforming growth factor beta receptor type I is associated with poor prognosis in bladder transitional cell carcinoma patients

Transforming growth factor (TGF) beta, a potent growth inhibitor of proliferation in most cells, usually exerts its effects through an interaction with membrane receptors, type I (TbetaR-I) and type II (TbetaR-II). In the present study, the expression of TGF-beta receptors was correlated with tumor grade, pathological stage, and probability of progression and survival in patients with bladder transitional cell carcinoma (TCC). To this end, immunohistochemistry was carried out in specimens obtained from 59 patients who underwent either radical cystectomy or transurethral resection of bladder tumor. Among these patients, 18 (30.5 %) had loss of TbetaR-I expression, whereas 27 (44.0%) had loss of TbetaR-II expression. There was a correlation between the loss of expression of TbetaR-I and TbetaR-II and the tumor grade (P = 0.041 and P = 0.026, respectively). In addition, both pathological and lymph node status also were associated with the loss of TbetaR-I and TbetaR-II expression (P = 0.025 and P = 0.004, respectively). Interestingly though, only the loss of expression of TbetaR-I was associated with an increased probability of tumor progression and a decreased probability of survival (P = 0.0046 and P = 0.0022, respectively). These results suggest that the status of TbetaR-I expression may be a potential prognostic marker in patients with bladder TCC.

Fetal mouse selenophosphate synthetase 2 (SPS2): biological activities of mutant forms in Escherichia coli

A novel gene, sps2, detected in mouse embryo at the early stages of development has been identified as an analog of the E. coli selenophosphate synthetase gene. Unlike the E. coli enzyme, the presence of selenocysteine in the mouse enzyme is indicated by a TGA codon in the open reading frame of the cDNA. Using an N-FLAG monoclonal antibody, it was shown that the full length N-FLAG-sps2 gene product was expressed in COS-7 cells. To investigate the biological activity of the sps2 gene product in vivo, the mutated sps2 gene, which contains cysteine in the place of the TGA encoded selenocysteine in the wild type, was expressed in the E. coli selD deficient mutant, MB08. Like the E. coli wild type selD gene, the mutant sps2 gene complemented the selD mutation. However, replacement of Cys with either Ala, Ser, or Thr resulted in a loss of ability to complement the selD mutation. The SPS2-CYS protein expressed in E. coli was purified and its catalytic activity was determined. The Km value for ATP was 0.75 mM and Vmax was 9.23 nmole/min/mg protein. These results confirm that the mouse embryonic sps2 gene encodes an eukaryotic selenophosphate synthetase, and that availability of selenophosphate as a selenium donor compound is widespread.