Deep learning-based electrocardiogram analysis detecting paroxysmal atrial fibrillation during sinus rhythm in patients with cryptogenic stroke: validation study using implantable cardiac monitoring

Background

Atrial fibrillation (AF) is the most cause of cardioembolic source causing cryptogenic stroke. In these, anticoagulation therapy could reduce recurrence of stroke. However, paroxysmal AF would not be detected even by 24 hours Holter monitoring. Deep learning-based electrocardiogram (ECG) analysis models were recently developed to detect AF during sinus rhythm.

Purpose

We aimed to develop a deep learning algorithm (DLA) to detect AF during sinus rhythm and validate the model in patients with cryptogenic stroke who underwent implantable cardiac monitoring (ICM) to diagnose paroxysmal AF.

Methods

This cohort study involved three hospitals (A, B, and C). We developed a DLA to detect AF using sinus rhythm 10 s 12-lead ECG. We included adult patients aged ≥18 years from hospital A and B. We used development data from AF adult patients who had at least one atrial fibrillation rhythm in the study period (Jan 2016 to Dec 2021) and non-AF patients who had no reference to AF in the ECG and electronic medical record. DLA was based on convolutional neural network (CNN) using 10 s 12-lead. For external validation, the ECGs from 217 patients (hospital C) with cryptogenic stroke who underwent ICM were analyzed by using the DLA for validating the accuracy in the real-world clinical situations.

Results

We included 10,605 AF adult patients and 50,522 non-AF patients as development data. During the internal validation, the area under the curve (AUC) of the final DLA based on CNN was 0.793 (95% Confidence interval 0.778–0.807). In external validation data from cryptogenic stroke patients, the mean ICM duration was 15.1 months, and AF >5 mins was detected in 32 patients (14.5%). The diagnostic accuracy of DLA was 0.793 to detect AF during sinus rhythm, and AUC was 0.824. The sensitivity, specificity, positive predictive value, and negative predictive value of the model were 0.844, 0.784, 0.403, and 0.967, respectively, which outperformed other conventional predictive methods based on clinical factors, such as CHARGE-AF, C2hest, and HATCH.

Conclusions

In this study, DLA accurately detected paroxysmal AF using 12-leads normal sinus rhythm ECG in patients with cryptogenic stroke and outperformed the conventional models. The DLA could be used as a screening tool to identify the cause of stroke in the future.

Funding Acknowledgement

Type of funding sources: None.

Comparison of a 1064-nm neodymium-doped yttrium aluminum garnet picosecond laser using a diffractive optical element vs. a nonablative 1550-nm erbium-glass laser for the treatment of facial acne scarring in Asian patients: a 17-week prospective, randomized, split-face, controlled trial

BACKGROUND

Novel picosecond lasers using a diffractive optical element (P-DOE) have been available for skin resurfacing with distinct mechanisms. However, there are limited data directly comparing P-DOE and conventional fractional lasers for the treatment of atrophic acne scarring.

OBJECTIVES

We sought to compare the efficacy and safety of a 1064-nm neodymium-doped yttrium aluminium garnet P-DOE and a non-ablative fractional laser (NAFL) in the treatment of acne scarring.

METHODS

A prospective, randomized, split-face, controlled trial was performed. One randomly assigned half-side of each patient's face (n = 25) was treated with four consecutive sessions of P-DOE at 3-week intervals and the other side with NAFL, with subsequent follow-up for 8 weeks after the final sessions. The efficacy and safety of the two lasers were determined by the Echelle d'Evaluation Clinique des Cicatrices d'acné (Scale of Clinical Evaluation of Acne Scars; ECCA) grading scale, Investigator's Global Assessment (IGA) score and patients' reports at the final visit. Histologic analysis was also performed.

RESULTS

The P-DOE-treated side achieved a significantly better improvement in acne appearance (ECCA per cent reduction: 55% vs. 42%) with less severe pain (4.3 vs. 5.6) (P < 0.05). The IGA score and subjective satisfaction were consistent with ECCA score results. Occurrences of treatment-related side-effects were also lower in the group treated with P-DOE (P < 0.05). Histologic analysis revealed elongation and increased density of neocollagen fibres, elastic fibres and mucin throughout the dermis from both sides.

CONCLUSIONS

Compared with NAFL, P-DOE afforded better clinical outcomes and fewer side-effects in the treatment of acne scarring in Asian patients.

P3429A novel prediction model for mortality after cardiac surgery using institutional case volume

Purpose

A number of risk prediction models have been developed to identify short term mortality after cardiovascular surgery. Most models include patient characteristics, laboratory data, and type of surgery, but no consideration for the amount of surgical experience. With numerous reports on the impact of case volume on patient outcome after high risk procedures, we attempted to develop a risk prediction models for in-hospital and 1-year mortality that takes institutional case volume into account.

Methods

We identified adult patients who underwent cardiac surgery from January 2008 to December 2017 from the National Health Insurance Service (NHIS) database by searching for patients with procedure codes of coronary artery bypass grafting, valve surgery, and surgery on thoracic aorta during the hospitalization. Study subjects were randomly assigned to either the derivation cohort or the validation cohort. In-hospital mortality and 1-year mortality data were collected using the NHIS database. Risk prediction models were developed from the derivation cohort using Cox proportional hazards regression. The prediction performances of models were evaluated in the validation cohort.

Results

The models developed in this study demonstrated fair discrimination for derivation cohort (N=22,004, c-statistics, 0.75 for in-hospital mortality; 0.73 for 1-year mortality) and acceptable calibration in the validation cohort. (N=22,003, Hosmer-Lemeshow χ2-test, P=0.08 and 0.16, respectively). Case volume was the key factor of mortality prediction models after cardiac surgery. (50≤ x <100 case per year. 100≤ x <200 case per year, ≥200 case per year are correlated with OR 3.29, 2.49, 1.85 in in-hospital mortality, 2.76, 1.99, 1.69 in 1-year mortality respectively, P value <0.001.)

Annual case volume as risk factor Variables In-hospital mortality 1-year mortality OR (95% CI) p-value OR (95% CI) p-value Annual case-volume (reference: ≥200) – – 100–200 1.69 (1.48, 1.93) <0.001 1.85 (1.58, 2.18) <0.001 50–100 1.99 (1.75, 2.25) <0.001 2.49 (2.15, 2.89) <0.001 <50 2.76 (2.44, 3.11) <0.001 3.29 (2.85, 3.79) <0.001 OR: Odds ratio; CI: confidence interval; Ref: Reference.

Discrimination and calibration

Conclusion

We developed and validated new risk prediction models for in-hospital and 1-year mortality after cardiac surgery using the NHIS database. These models may provide useful guides to predict mortality risks of patients with basic information and without laboratory findings.

Evaluation of infertility efficacy of the E. coli expressed STF2-GnRH vaccine in male cats

Gonadotropin-releasing hormone (GnRH) is secreted from the hypothalamus and anti-GnRH antibodies are not formed under normal conditions. However, administration an excess of recombinant GnRH protein results in the formation of anti-GnRH. We evaluated the efficacy of the recombinant Salmonella typhimurium flagellin fljB (STF2)-GnRH vaccine in inducing infertility in 17 intact male cats. The first vaccination and a boosting vaccine was injected for examination. Serum was obtained from blood collected at monthly intervals and anti-GnRH antibodies and testosterone concentrations were determined. Six months after the vaccination, testicular samples are obtained and used for histological examination. Compared with sham control group, the injection groups showed an increase in anti-GnRH antibody titers and testosterone concentrations tended to be reduced in the injection groups and increased in the control group. Histological evaluations and Johnsen's testicular biopsy scores revealed testicular hypoplasia in the 2 injection groups. Consequently, normal sexual maturation with sperm production was observed in the control group. In contrast, the cats that received the GnRH vaccine showed weak (2 of 7 cats) or moderate (4 out of 7 cats) dose-dependent infertility effects. On the basis of the results, the STF2-GnRH vaccine was identified to be effective in inducing infertility in male cats. The results of this study thus indicate the possibility of immunological castration targeting feral cats.

MR Imaging-Based Radiomic Signatures of Distinct Molecular Subgroups of Medulloblastoma

BACKGROUND AND PURPOSE

Distinct molecular subgroups of pediatric medulloblastoma confer important differences in prognosis and therapy. Currently, tissue sampling is the only method to obtain information for classification. Our goal was to develop and validate radiomic and machine learning approaches for predicting molecular subgroups of pediatric medulloblastoma.

MATERIALS AND METHODS

In this multi-institutional retrospective study, we evaluated MR imaging datasets of 109 pediatric patients with medulloblastoma from 3 children's hospitals from January 2001 to January 2014. A computational framework was developed to extract MR imaging-based radiomic features from tumor segmentations, and we tested 2 predictive models: a double 10-fold cross-validation using a combined dataset consisting of all 3 patient cohorts and a 3-dataset cross-validation, in which training was performed on 2 cohorts and testing was performed on the third independent cohort. We used the Wilcoxon rank sum test for feature selection with assessment of area under the receiver operating characteristic curve to evaluate model performance.

RESULTS

Of 590 MR imaging-derived radiomic features, including intensity-based histograms, tumor edge-sharpness, Gabor features, and local area integral invariant features, extracted from imaging-derived tumor segmentations, tumor edge-sharpness was most useful for predicting sonic hedgehog and group 4 tumors. Receiver operating characteristic analysis revealed superior performance of the double 10-fold cross-validation model for predicting sonic hedgehog, group 3, and group 4 tumors when using combined T1- and T2-weighted images (area under the curve = 0.79, 0.70, and 0.83, respectively). With the independent 3-dataset cross-validation strategy, select radiomic features were predictive of sonic hedgehog (area under the curve = 0.70-0.73) and group 4 (area under the curve = 0.76-0.80) medulloblastoma.

CONCLUSIONS

This study provides proof-of-concept results for the application of radiomic and machine learning approaches to a multi-institutional dataset for the prediction of medulloblastoma subgroups.

Functional status of immune cells in patients with long-lasting type 2 diabetes mellitus

Although patients with diabetes contract infectious diseases at higher frequencies, and in more severe forms, compared to non-diabetics, the underlying defects of the immune function have not been defined clearly. To address this, we designed an immune monitoring protocol and analysed the functional status of various immune cells. Peripheral blood mononuclear cells (PBMCs) were stimulated with the proper ligands and the functional reactivity of each lineage of cells was subsequently measured. Patients with type 2 diabetes mellitus (T2DM) had PBMC composition ratios comparable to healthy controls, except for a higher frequency of B cell and effector T cell fractions. The capacity of myeloid cells to secrete proinflammatory cytokines was not diminished in terms of the sensitivity and magnitude of the response. Furthermore, cytolytic activity and interferon (IFN)-γ production of natural killer (NK) cells and CD8⁺ T cells were not decreased in T2DM patients. Phenotypical maturation of dendritic cells, indicated by the up-regulation of major histocompatibility complex (MHC) proteins and co-stimulatory molecules in response to lipopolysaccharide (LPS), was slightly enhanced in T2DM patients. Finally, the functional differentiation profiles of CD4⁺ T cells did not differ between T2DM patients and the control group. These data indicate that patients with long-lasting T2DM do not have any gross functional defects in immune cells, at least in circulating monocytes, dendritic cells, NK cells and T lymphocytes.

Dielectric function, critical points, and Rydberg exciton series of WSe2 monolayer

The complex dielectric function ([Formula: see text]) of WSe₂ monolayer grown by atomic layer deposition is investigated using spectroscopic ellipsometry. Band structure parameters are obtained by standard line-shape analysis of the second-energy-derivative of [Formula: see text] spectra. The fundamental band gap is observed at 2.26 eV, corresponds to transition between valence band (VB) maximum at the K point and conduction band (CB) minimum at Q point in the Brillouin zone (BZ). Two strong so-called A and B excitonic peaks in [Formula: see text] spectra originate from vertical transitions from spin-orbit split (0.43 eV) VB to CB at K point of the BZ. Binding energies of A and B exactions are 0.71 and 0.28 eV, respectively. Well resolved five excited excitons states has been detected within the spectral region between A and B. Energy profile of the Rydberg series shows significant deviation from the hydrogenic behavior, discussed in connection with the 2D hydrogen model. Results presented here will improve our understanding about the optical response of 2D materials and will help to design better optoelectronic applications and validate theoretical considerations.

Performance of the Minto model for the target-controlled infusion of remifentanil during cardiopulmonary bypass

We studied the predictive performance of the Minto pharmacokinetic model during cardiopulmonary bypass in patients undergoing cardiac surgery. Patients received remifentanil target-controlled infusion using the Minto model during total intravenous anaesthesia with propofol. From 56 patients, 275 arterial blood samples were drawn before, during and after bypass to determine the plasma concentration of remifentanil, and the predicted concentrations were recorded at each time. For pooled data, the median prediction error and median absolute prediction error were 21.3% and 21.8%, respectively, and 22.1% and 22.3% during bypass. Both were 148.4% during hypothermic circulatory arrest and measured concentrations were more than three times greater than predicted (26.9 (17.0) vs. 7.1 (1.6) ng.ml^-1 ). The Minto model showed considerable bias but overall acceptable precision during bypass. The target concentration of remifentanil should be reduced when using the Minto model during hypothermic circulatory arrest.

Protective effect of pterostilbene on testicular ischemia/reperfusion injury in rats

PURPOSE

To evaluate protective effect of pterostilbene against testicular ischemia/reperfusion (I/R) injury, which results in increased formation of oxidative stress, leading to testicular apoptosis and impaired spermatogenesis.

METHODS

Thirty two pubertal male Sprague-Dawley rats weighing 180-220g were selected and randomly divided into the following four groups: group A (normal control group), group B (sham-operated group), group C (induced I/R injury group), group D (induced I/R injury group receiving pterostilbene treatment). Johnsen's scores and mean seminiferous tubule diameters were evaluated for histopathologic assessment; germinal cell apoptosis was evaluated by the transferase dUTP nick end labeling (TUNEL) assay and immunohistochemistry for caspases. Malondialdehyde (MDA) levels were assessed as an indicator of oxidative stress and total antioxidant capacity (TAC) was measured.

RESULTS

Germ cell apoptosis and MDA level significantly increased whereas TAC significantly decreased in group C; moreover, abnormal morphology and impaired spermatogenesis were observed in group C. In contrast, treatment with pterostilbene inhibited lipid peroxidation and apoptosis induced by ROS and restored the antioxidant capacity in group D.

CONCLUSIONS

These results show that treatment with pterostilbene may be a promising therapy for testicular I/R injury.

Effect of intravitreal dexamethasone implant on retinal and choroidal thickness in refractory diabetic macular oedema after multiple anti-VEGF injections

AimsTo investigate the effect of intravitreal dexamethasone implant (IVD) on central foveal thickness (CFT), choroidal thickness (CT) and its correlation with visual acuity in eyes with refractory diabetic macular oedema (DMO).MethodsThis was a retrospective interventional case-series. Thirty-five eyes of 35 patients were treated with a single injection of IVD because of refractory DMO with CFT over 300 μm, and persistent intraretinal and subretinal fluid despite of multiple intravitreal bevacizumab injections. Patients were followed-up for 6 months for the evaluation of CFT and subfoveal CT by spectral-domain optical coherence tomography.ResultsAll eyes (mean age: 59.4±12.35 years; 18 males, 17 females) had been previously treated with multiple bevacizumab injections and showed persistent DMO (mean number of injections 4.08±2.98) The preoperative logMAR BCVA was 0.49±0.24, which gradually improved to 0.46±0.32 at 6 months (P=0.652) and 26% gained two or more lines of Snellen visual acuity. At baseline, the mean CFT was 526.29±123.48 μm, which significantly improved to 316.15±100.09 μm at 3 months (P<0.001). However, CFT deteriorated to 457.07±136.53 μm at 6 months (P=0.051). Similarly, the mean preoperative subfoveal CT was 288.91±36.47 μm and it decreased to 266.85±30.93 μm at 3 months (P<0.01), but increased to 278.63±32.55 μm at 6 months (P=0.137). The reduction of CFT from baseline showed significant correlation with that of subfoveal CT at 3 months (P=0.041) and at 6 months (P=0.008).ConclusionsIn DMO refractory to multiple bevacizumab injections, IVD significantly reduced CFT and subfoveal CT, with BCVA improvement in one-fourth of the patients. The reduction of CFT showed significant correlation with reduction of subfoveal CT.

Comparison of short wrist transverse open and limited open techniques for carpal tunnel release: a randomized controlled trial of two incisions

The purpose of this randomized controlled trial was to compare outcomes of limited open and short wrist transverse techniques in patients with carpal tunnel syndrome. In a single centre randomized controlled trial, 84 patients with idiopathic carpal tunnel syndrome were randomized before surgery to limited open or short wrist transverse open carpal tunnel release. The patients were evaluated at 6 weeks, 3 months, 6 months, and 1 and 2 years after surgery. At every follow-up, the Brigham and Women's Carpal Tunnel Questionnaire scores, scar discomfort, and subjective patient satisfaction were evaluated. Two years after surgery, five patients were lost to follow-up. The groups had similar Brigham and Women's Carpal Tunnel Questionnaire Symptom Severity and Functional Status scores and subjective satisfaction scores. The incidence of scar discomfort was not significantly different between the two groups on serial postoperative follow-up. Short wrist transverse open release surgery showed similar early postoperative symptoms and subjective and functional outcomes to limited open release.

LEVEL OF EVIDENCE

II.

Comparison of short wrist transverse open and limited open techniques for carpal tunnel release: a randomized controlled trial of two incisions

The purpose of this randomized controlled trial was to compare outcomes of limited open and short wrist transverse techniques in patients with carpal tunnel syndrome. In a single centre randomized controlled trial, 84 patients with idiopathic carpal tunnel syndrome were randomized before surgery to limited open or short wrist transverse open carpal tunnel release. The patients were evaluated at 6 weeks, 3 months, 6 months, and 1 and 2 years after surgery. At every follow-up, the Brigham and Women's Carpal Tunnel Questionnaire scores, scar discomfort, and subjective patient satisfaction were evaluated. Two years after surgery, five patients were lost to follow-up. The groups had similar Brigham and Women's Carpal Tunnel Questionnaire Symptom Severity and Functional Status scores and subjective satisfaction scores. The incidence of scar discomfort was not significantly different between the two groups on serial postoperative follow-up. Short wrist transverse open release surgery showed similar early postoperative symptoms and subjective and functional outcomes to limited open release.

LEVEL OF EVIDENCE

II.

Transarterial embolisation of renal arteriovenous malformation: safety and efficacy in 24 patients with follow-up

AIM

To evaluate the efficacy and safety of renal artery embolisation (RAE) for renal arteriovenous malformation (AVM) as well as its outcomes.

MATERIALS AND METHODS

The technical and clinical success rates, radiological and laboratory findings, and complications of RAE for 31 renal AVMs in 24 patients (M:F=9:15, mean age 46 years) at two separate medical institutions were retrospectively evaluated. Technical success was defined as complete occlusion of feeding arteries with no residual nidus seen on post-treatment angiography. Clinical failure was defined as recurrence of haematuria, presence of AVM on follow-up ultrasound or computed tomography, repeated RAE or surgery for the control of haematuria. Overall clinical success was defined as resolution haematuria or disappearance of AVM on follow-up imaging after single or multiple sessions of RAE.

RESULTS

Types of renal AVM were AVM, arterio-venous fistula (AVF) with intranidal aneurysm, and acquired AVF in 19, 1, and 4 patients, respectively. 18 patients (75%) underwent a single session of RAE, while 6 patients (25%) had two or more sessions of RAE. The level of embolisation was feeder, segmental artery, and main renal artery in 28 (90%), 2 (6%), and 1 (4%) procedures, respectively. Coil, n-butyl 2-cyanoacrylate, and polyvinyl alcohol were the most frequently chosen embolic materials and were used in 19, 14, and 8 procedures, respectively. The clinical success rate after initial RAE was 67% (16/24). Overall clinical success rate, including multisession RAE, was 88% (21/24). The technical success rate of 31 procedures was 65% (20/31). Among 11 technical failures in 10 patients, 4 achieved clinical success without additional RAE, 3 underwent second session RAE to achieve clinical success, and 3 patients underwent nephrectomy due to recurrence.

CONCLUSION

RAE is a safe and effective treatment for renal AVM. Technical failure of RAE does not always lead to clinical failure and multiple embolisation sessions may be effective for recurrent renal AVM.

The expression of vascular endothelial growth factor and Syndecan-4 in cartilage from osteoarthritic knees

Previous studies support the important role of vascular endothelial growth factor (VEGF) and syndecan-4 in the pathogenesis of osteoarthritis (OA). Both VEGF and syndecan-4 are expressed by chondrocytes and both are involved in the regulation of matrix metalloproteinase-3, resulting in the activation of aggrecanase II (ADAMTS-5), which is essential in the pathogenesis of OA. However, the relationship between VEGF and syndecan-4 has not been established. As a pilot study, we assayed the expression of VEGF and syndecan-4 in cartilage samples and cultured chondrocytes from osteoarthritic knee joints and analysed the relationship between these two factors. Specimens were collected from 21 female patients (29 knees) who underwent total knee replacement due to severe medial OA of the knee (Kellgren-Lawrence grade 4). Articular cartilage samples, obtained from bone and cartilage excised during surgery, were analysed and used for chondrocyte culture. We found that the levels of expression of VEGF and syndecan-4 mRNA did not differ significantly between medial femoral cartilage with severe degenerative changes and lateral femoral cartilage that appeared grossly normal (p = 0.443 and 0.622, respectively). Likewise, the levels of expression of VEGF and syndecan-4 mRNA were similar in cultured chondrocytes from medial and lateral femoral cartilage. The levels of expression of VEGF and syndecan-4 mRNAs were significantly and positively correlated in cartilage explant (r = 0.601, p = 0.003) but not in cultured chondrocytes. These results suggest that there is a close relationship between VEGF and syndecan-4 in the cartilage of patients with OA. Further studies are needed to determine the exact pathway by which these two factors interact in the pathogenesis of OA.

MRI surrogates for molecular subgroups of medulloblastoma

BACKGROUND AND PURPOSE

Recently identified molecular subgroups of medulloblastoma have shown potential for improved risk stratification. We hypothesized that distinct MR imaging features can predict these subgroups.

MATERIALS AND METHODS

All patients with a diagnosis of medulloblastoma at one institution, with both pretherapy MR imaging and surgical tissue, served as the discovery cohort (n = 47). MR imaging features were assessed by 3 blinded neuroradiologists. NanoString-based assay of tumor tissues was conducted to classify the tumors into the 4 established molecular subgroups (wingless, sonic hedgehog, group 3, and group 4). A second pediatric medulloblastoma cohort (n = 52) from an independent institution was used for validation of the MR imaging features predictive of the molecular subtypes.

RESULTS

Logistic regression analysis within the discovery cohort revealed tumor location (P < .001) and enhancement pattern (P = .001) to be significant predictors of medulloblastoma subgroups. Stereospecific computational analyses confirmed that group 3 and 4 tumors predominated within the midline fourth ventricle (100%, P = .007), wingless tumors were localized to the cerebellar peduncle/cerebellopontine angle cistern with a positive predictive value of 100% (95% CI, 30%-100%), and sonic hedgehog tumors arose in the cerebellar hemispheres with a positive predictive value of 100% (95% CI, 59%-100%). Midline group 4 tumors presented with minimal/no enhancement with a positive predictive value of 91% (95% CI, 59%-98%). When we used the MR imaging feature-based regression model, 66% of medulloblastomas were correctly predicted in the discovery cohort, and 65%, in the validation cohort.

CONCLUSIONS

Tumor location and enhancement pattern were predictive of molecular subgroups of pediatric medulloblastoma and may potentially serve as a surrogate for genomic testing.

Pathogen inactivation efficacy of Mirasol PRT System and Intercept Blood System for non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma

BACKGROUND AND OBJECTIVES

This study was conducted to evaluate the efficacy of pathogen inactivation (PI) in non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma using the Mirasol PRT System and the Intercept Blood System.

METHODS

Platelets were pooled using the Acrodose PL system and separated into two aliquots for Mirasol and Intercept treatment. Four replicates of each viral strain were used for the evaluation. For bacteria, both low-titre (45-152 CFU/unit) inoculation and high-titre (7·34-10·18 log CFU/unit) inoculation with two replicates for each bacterial strain were used. Platelets with non-detectable bacterial growth and platelets inoculated with a low titre were stored for 5 days, and culture was performed with the BacT/ALERT system.

RESULTS

The inactivation efficacy expressed as log reduction for Mirasol and Intercept systems for viruses was as follows: human immunodeficiency virus 1, ≥4·19 vs. ≥4·23; bovine viral diarrhoea virus, 1·83 vs. ≥6·03; pseudorabies virus, 2·73 vs. ≥5·20; hepatitis A virus, 0·62 vs. 0·76; and porcine parvovirus, 0·28 vs. 0·38. The inactivation efficacy for bacteria was as follows: Escherichia coli, 5·45 vs. ≥9·22; Staphylococcus aureus, 4·26 vs. ≥10·11; and Bacillus subtilis, 5·09 vs. ≥7·74. Postinactivation bacterial growth in platelets inoculated with a low titre of S. aureus or B. subtilis was detected only with Mirasol.

CONCLUSION

Pathogen inactivation efficacy of Intercept for enveloped viruses was found to be satisfactory. Mirasol showed satisfactory inactivation efficacy for HIV-1 only. The two selected non-enveloped viruses were not inactivated by both systems. Inactivation efficacy of Intercept was more robust for all bacteria tested at high or low titres.

Patients' beliefs and behaviors related to treatment adherence in patients with asthma requiring maintenance treatment in Asia

Objectives

To identify patients’ beliefs or behaviors related to treatment adherence and to assess association between asthma control and adherence in Asian patients with asthma.

Methods

We conducted a cross-sectional observational study of adult patients with asthma from specialist clinics in six Asian countries. Patients who were deemed by their treating physicians to require a maintenance treatment with an inhaler for at least 1 year were recruited. Patients completed a 12-item questionnaire related to health beliefs and behaviors, the 8-item Morisky Medication Adherence Scale (MMAS-8), the Asthma Control Test (ACT™), and the Standardized Asthma Quality of Life Questionnaire (AQLQ-S).

Results

Of the 1054 patients recruited, 99% were current users of inhaled corticosteroids. The mean ACT score was 20.0 ± 4.5 and 64% had well-controlled asthma. The mean MMAS-8 score was 5.5 ± 2.0 and 53% were adherent. Adherence was significantly associated with patients’ understanding of the disease and inhaler techniques, and with patients’ acceptance of inhaler medicines in terms of benefits, safety, convenience, and cost (p < 0.01 for all). In multivariate analysis, three questions related to patients’ acceptance of inhaler medicines remained significantly associated with poor adherence, after adjusting for potential confounders: “I am not sure inhaler type medicines work well” (p = 0.001), “Taking medicines more than once a day is inconvenient” (p = 0.002), and “Sometimes I skip my inhaler to use it over a longer period” (p < 0.001).

Conclusions

Our study showed that patients’ acceptance of the benefits, convenience and cost of inhaler medications have a significant impact on treatment adherence in the participating Asian countries.

Inhaled hydrogen gas therapy for prevention of testicular ischemia/reperfusion injury in rats

PURPOSE

This study evaluated whether 2% hydrogen (H(2)) gas therapy protects against testicular ischemia/reperfusion injury which results in increased formation of reactive oxygen species and/or reactive nitrogen species, leading to testicular apoptosis and impaired spermatogenesis.

METHODS

Pubertal six-week-old Spraque-Dawley rats were assigned to 5 groups (10 animals/group) as follows: group A was a sham operated group; groups B, C, D, and E underwent 5 hours of left testicular ischemia followed by 0, 30, 60, and 120 minutes of 2% H(2) gas therapy, respectively. Histological analysis was performed to verify structure and morphology of the testes and to investigate Johnsen scores, mean seminiferous tubule diameter, and the number of germ cell layers to classify spermatogenesis. Germ cell apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling assay and Bax/Bcl-2 ratio real-time polymerase chain reaction. We also investigated malondialdehyde levels as an indicator of lipid peroxidation.

RESULTS

Compared to the sham group (A), germ cell apoptosis and lipid peroxidation in the ischemia group (B) were significantly increased with abnormal morphology and impaired spermatogenesis. In contrast, amelioration of testicular damages was evident in the H(2) therapy groups (C, D, and E).

CONCLUSIONS

Our results showed that inhalation of 2% H(2) gas may be a promising therapy with anti-apoptotic and anti-oxidant properties in cases of testicular ischemia/reperfusion injury.

Effects of various anesthetic protocols on 18F-flurodeoxyglucose uptake into the brains and hearts of normal miniature pigs (Sus scrofa domestica)

This study used positron emission tomography-computed tomography (PET-CT) to evaluate the effects of 4 anesthetic protocols on 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) accumulation in the brains and hearts of miniature pigs (Sus scrofa domestica). The 18F-FDG standard uptake value was quantified by dividing the brain into 6 regions: cerebellum, brainstem, and frontal, parietal, temporal, and occipital lobes. Five (2 female and 3 male) clinically normal miniature pigs were premedicated with medetomidine (200 μg/kg IM) after which the following 4 anesthetic protocols were administered by using a crossover design: 1) propofol (4 mg/kg IV)-isoflurane inhalation; 2) propofol (4 mg/kg IV); 3) ketamine (5 mg/kg IV); 4) tiletamine-zolazepam (4.4 mg/kg IM). Compared with levels after other protocols, brain accumulation of 18F-FDG increased during propofol anesthesia but decreased with tiletamine-zolazepam. Relative to that due to other protocols, heart accumulation of 18F-FDG increased with propofol-isoflurane anesthesia but decreased with tiletamine-zolazepam. Comparing glucose accumulation in the brain and heart of miniature pigs by using PET-CT, we found that glucose accumulation varied according to the anesthetic protocol and between the 2 organs. These results can be used to evaluate how different anesthetic agents affect glucose metabolism in brain and heart of miniature pigs. Furthermore, these data should be considered when selecting an anesthetic agent for miniature pigs that will undergo PET-CT imaging with 18F-FDG.

3D reconstructions of spinal segmental arteries using CT angiography: applications in minimally invasive spinal procedures

BACKGROUND AND PURPOSE

Injury to spinal segmental arteries may potentially occur during spinal surgery, particularly during anterior or minimally invasive approaches. Use of a noninvasive radiologic tool to evaluate these arteries before surgery may reduce this risk.

MATERIAL AND METHODS

We performed spinal CT angiography and reconstructed 3D images of segmental arteries in 41 patients. We classified the pathways and locations of the segmental arteries into 4 zones (A, B, C, and D) according to pedicle and vertebral endplates. We designated segmental arteries from T8 to L1 as "high-level segmental arteries" and those from L2 to L4, as "low-level segmental arteries." We compared the distribution of segmental arteries between these 2 groups. We also investigated anatomic variations of segmental arteries and the rate of occurrence of the artery of Adamkiewicz.

RESULTS

In all patients, 3D reconstruction images from spinal CT angiography clearly showed the pathways of segmental arteries on the vertebral bodies. Most of the segmental arteries passed the middle portion of the vertebral body (zones B and C). However, 51 of 738 segmental arteries (6.9%) had uncommon pathways (zones A and D), and segmental arteries from L2 to L4 had a higher incidence of uncommon pathways than higher level vertebrae (P < .05). We also observed 2 types of segmental artery anatomic variation, agenesis and dual supply.

CONCLUSIONS

We suggest that spinal CT angiography can help to precisely visualize the spinal segmental arteries and surrounding bony structures and can aid clinicians in deciding on optimal approaches for spinal surgery.

Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy

Radiosynoviorthesis is a safe and easy method for synovectomy in haemophilic arthropathy. Various agents have been used in radiosynoviorthesis, especially newly developed agent Holmium-166-chitosan complex has good clinical outcome. This study analysed clinical results and radiologic evaluation of radioisotope synoviorthesis using Holmium-166-chitosan complex in haemophilic arthropathy. From March 2001 to December 2003, 58 radiosynoviorthesis were performed in 53 haemophiliacs. The average age at procedure was 13.8 years. The Arnold and Hilgartner stage of the patients was from I to IV. Holmium-166-chitosan complex was injected in 31 ankle joints, 19 elbow joints and 8 knee joints. Average follow-up was 33 months since primary procedure. The range of motion of each joint, frequency of intra-articular bleeding and factor dose used were analysed for clinical assessment. There was no significant improvement of range of motion in affected joints. After procedure, the average frequency of bleeding of the elbow joint has decreased from 3.76 to 0.47 times per month, the knee joint from 5.87 to 1.12 times per month, and the ankle joint from 3.62 to 0.73 times per month respectively (P < 0.05). After treatment, the average coagulation factor dose injected was significantly decreased to 779.3 units per month from 2814.8 units per month before treatment (P < 0.001). Radioisotope synoviorthesis with Holmium-166-chitosan complex in haemophilic arthropathy is a very safe and simple procedure with the expectation of a satisfactory outcome without serious complication. It has excellent bleeding control effect on target joint and the need for substitution of coagulation factor concentrate can be reduced.

Nerve growth factor and expression of its receptors in patients with diabetic neuropathy

AIMS

Low serum nerve growth factor (NGF) levels have been reported in patients with diabetic peripheral neuropathy (DPN), but the role of NGF in the development of neuropathy is unclear. Thus, we investigated the associations of serum NGF level and NGF receptor activity with the presence and severity of DPN.

METHODS

One hundred and thirty-six patients with Type 2 diabetes were included in this cross-sectional study. Serum NGF levels were measured by ELISA. Expressions of NGF receptors (TrkA and p75(NTR)) were measured by immunohistochemical staining. The presence and severity of DPN were assessed by neuropathy disability score (NDS) and by corneal nerve fibre length (cNFL) and nerve branch density (cNBD) using in vivo confocal microscopy.

RESULTS

Patients with DPN had higher serum NGF levels (56-451 pg/ml) than patients without DPN (4-54 pg/ml). However, in DPN patients, serum NGF was negatively associated with neuropathy severity (mild 222 +/- 64 pg/ml; moderate 114 +/- 17 pg/ml; severe 89 +/- 20 pg/ml). This negative association was consistent in all severity indices (NDS, P < 0.001; cNFL, P < 0.001; cNBD P = 0.010) even after adjustment for age, sex, diabetes duration, insulin use, fasting glucose and glycated haemoglobin. Although NGF receptor activities had significantly (P < 0.05) negative associations with the presence and severity of neuropathy, these associations were not significant when adjusted for other factors.

CONCLUSIONS

Serum NGF level was positively associated with the presence of DPN but negatively associated with neuropathy severity in DPN patients. The change in serum NGF might be a consequence of, rather than a contributor to, the early development of DPN.

Prenatal multivitamins containing folic acid do not decrease prevalence of depression among pregnant women

Several studies have reported an association between depression and folic acid deficiency. We investigated whether intake of prenatal multivitamins containing folic acid (MVandFA) was associated with decreased rates of depression among pregnant women. A questionnaire was given to 1,314 low-risk pregnant women. Of them, 1,277 (97.2%) women completed the questionnaire. The overall prevalence of depression was 8.1%. Of 652 participants who did not take MVandFA, 9.4% had depression, whereas 6.9% of 624 women who had MVandFA had depression (p = 0.11). In a multivariate logistic regression analysis, family history of depression (adjusted OR 3.7; 95% CI 1.9-7.3) and premenstrual syndrome (adjusted OR 3.0, 95% CI 1.8-4.8) were identified as risk factors for depression during pregnancy. In conclusion, intake of MVandFA was not associated with lower rates of depression during pregnancy whereas family history of depression and personal history of premenstrual syndrome were significant risk factors.

Carrier-mediated antiferromagnetic interlayer exchange coupling in diluted magnetic semiconductor multilayers Ga1-xMnxAs/GaAs:Be

We report the antiferromagnetic (AFM) interlayer exchange coupling between Ga0.97Mn0.03As ferromagnetic semiconductor layers separated by Be-doped GaAs spacers. Polarized neutron reflectivity reveals a characteristic splitting at the wave vector corresponding to twice the multilayer period, indicating that the coupling between the ferromagnetic layers is AFM. When the applied field is increased to above the saturation field, this AFM coupling is suppressed. This behavior is not observed when the spacers are undoped, suggesting that the observed AFM coupling is mediated by doped charge carriers.

Conservative treatment for transient osteoporosis of the hip in middle-aged women

Transient osteoporosis of the hip is a clinical entity that is being diagnosed and reported with increasing frequency. Its aetiology remains a matter of speculation, and the same remains true for its treatment. Many researchers have proposed different surgical and non-surgical treatment strategies; but the conservative approach, which takes the form of analgesics, intermittent traction, range of motion exercises, abductor strengthening exercises and restricted weight bearing, is preferred. The authors report on two patients, both women, aged 35 years and 42 years, respectively, with transient osteoporosis of the hip that were successfully treated using a conservative approach.

The hydrodynamic filter separator for removal of urban storm runoff

The majority of storm runoff pollution is trapped in particles smaller than 100 microm in diameter. Solid particles smaller than 100 microm in diameter are not easily separated by conventional types of hydrodynamic separator, and remain in suspension in overflow. To overcome this problem, a HDFS (hydrodynamic filter separator) has been developed for treatment of the microparticles in urban storm runoff. We conducted a laboratory scale study on treatable potential of microparticles using HDFS that combined HDS with perlite filter. To determine the efficiency for various operation conditions, a series of experiments was performed with different solids concentrations and surface loading rate. The operation ranges of surface loading rates were 100 to 2,800 m3/m2/day, and influent solids concentrations were varied from 800 to 1,900 mg/L. Also, the particle size distribution was monitored to investigate the effects of surface loading rates on the particle size. Results indicated that the HDFS-inside type showed greater efficiency at solids separation than the other type.

Antibacterial and antifungal activity of pinosylvin, a constituent of pine

The antibacterial and antifungal activities of pinosylvin (3,5-dihydroxy-trans-stilbene), a constituent of pine, were studied and compared with those of resveratrol (3,5,4'-trihydroxy-trans-stilbene). Pinosylvin exhibited more potent growth inhibitory activity against Candida albicans and Saccharomyces cerevisiae.

The effect of TGF-beta on the induction CD8 and NK1.1 expression in CTLL-2 cell line

BACKGROUND

The presence of CD8+ T-cells expressing NK cell associated markers (TNK cells) has been observed in several experimental models, which suggests that NK cells may belong to the T-cell lineage. We used the CTLL-2 cell line, which is NK1.1+ CD3- TCR+ CD4- CD8- cells in the presence of IL-2, to investigate whether these cells can be switched to CD8+ or CD4+ cells, like TNK cells, by the TGF-beta.

METHODS

CTLL-2 cells were cultured with TGF-beta or other cytokines and activators in the presence of IL-2. In order to see the surface and intracytoplasmic antigen expression in a single-cell level, simultaneous surface CD4, CD8, TCR with NK1.1, and intracytoplasmic NK1.1 staining was performed and three-color flow cytometric analysis was performed.

RESULTS

During routine passage, less than 5% of cells were CD8a+, although 20-40% of cells expressed CD8a when treated with IL-2 + TGF-beta, whereas TPA + Calcium ionophore, IFN-gamma, and TNF-alpha cause no significant changes in the proportion of CD8+ cells. Twenty percent of CTLL-2 cells expressed NK1.1 with IL-2 treatment, and this expression was also increased up to 65%-70% with IL-2 + TNF-beta. Furthermore, most of the CD8 positive cells showed intracytoplasmic NK1.1.

CONCLUSION

Our results indicated that these would be useful models to investigate CD8 precursor potentials in populations of CD4-CD8- (double negative) cells and the relationship of NK1.1. These results also support a role for TGF-beta in T-cell differentiation and the hypothesis that T-cells and NK cells may have the same ontogeny.

Production of red pigment by submerged culture of Paecilomyces sinclairii

AIMS

From a survey of submerged culture of edible mushrooms, a high pigment-producing fungus Paecilomyces sinclairii was selected and its optimal culture conditions investigated.

METHODS AND RESULTS

The optimal culture conditions for pigment production were as follows: inoculum age, 3 d; temperature, 25 degrees C; initial pH, 6.0; carbon source, 1.5% (w/v) soluble starch; nitrogen source, 1.5% (w/v) meat peptone. Although addition of 10 mmol l(-1) CaCl2 to the culture medium slightly increased pigment production, most of the bio-elements examined had no notable or detrimental effect on pigment production.

CONCLUSIONS

Under the optimal conditions obtained in the flask culture tested, a ninefold increase in pigment production (4.4 g l(-1)) was achieved using a 5(-l) batch fermenter. Paecilomyces sinclairii secreted water-soluble red pigment into the culture medium. The pigment colour was strongly dependent on the pH of the solution: red at pH 3-4, violet at pH 5-9 and pink at pH 10-12.

SIGNIFICANCE AND IMPACT OF THE STUDY

The high concentration of pigment (4.4 g l(-1)) produced by P. sinclairii demonstrates the possibility of commercial production of pigment by this strain, considering its relatively high production yield and light stability.

Effect of agitation intensity on the exo-biopolymer production and mycelial morphology in Cordyceps militaris

AIMS

The influence of agitation intensity on Cordyceps militaris morphology and exo-biopolymer production was investigated in a 5 litre stirred vessel using a six-blade Rushton turbine impeller.

METHODS AND RESULTS

The mycelial morphology of C. militaris was characterized by means of image analysis, which included mean diameter, circularity, roughness and compactness of the pellets. The morphological parameters of the pellets grown under different stirring conditions were significantly different, which correspondingly altered exo-biopolymer production yields.

CONCLUSIONS

The compactness of the pellets was found to be the most critical parameter affecting exo-biopolymer biosynthesis; more compact pellets were formed at 150 rev min(-1) with maximum exo-biopolymer production (15 g l(-1)).

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study suggest that morphological change of pellets is a good indicator for identifying the cell activity for exo-biopolymer production.

Mycelial growth and exo-biopolymer production by submerged culture of various edible mushrooms under different media

AIMS

The effect of synthetic media on the submerged mycelial growth and exo-biopolymer production in various edible mushrooms was investigated in shake flask culture.

METHODS AND RESULTS

Among 19 mushrooms examined, the relatively high yield in mycelial biomass and exo-biopolymer production was achieved in potato malt peptone (PMP) medium. In particular, Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 showed favourable growth in PMP medium with exo-biopolymer concentration of 1170 and 1520 mg l(-1), respectively.

CONCLUSIONS

Enhanced exo-biopolymer production was achieved from Ganoderma lucidum NO. 1 and Phellinus linteus KCTC 6190 in a 5L batch fermentor, indicating approximately 5000 and 2410 mg l(-1), respectively.

SIGNIFICANCE AND IMPACT OF THE STUDY

The exo-biopolymer production and mycelial growth from various mushrooms were found to be strongly controlled by different complex media.

New galactolipids from the marine bacillariophycean microalga Nitzschia sp

Two new galactopyranosyldiacylglycerols have been isolated from the marine bacillariophycean microalga Nitzschia sp. and their structures were determined as (2S)-3-O-beta-D-galactopyranosyl-1,2-di-O-(9Z-hexadecenoyl)glycerol (1) and (2S)-3-O-beta-D-galactopyranosyl-1-O-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-O-(9Z-hexadecenoyl)glycerol (2) by physicochemical evidence.

Diffusion-weighted magnetic resonance imaging in Wernicke's encephalopathy

OBJECTIVE

To report diffusion-weighted imaging (DWI) findings and postulate the pathogenic mechanism of Wernicke's encephalopathy (WE).

PATIENT

A 47-year-old-woman presented with altered consciousness, ophthalmoplegia, and ataxia. DWI revealed the abnormal signal changes in periaqueductal gray matter, mamillary bodies and bilateral medial thalami. Apparent diffusion coefficient (ADC) map revealed the high signal intensity lesions in bilateral medial thalami, suggestive of vasogenic edema. The abnormal signal intensity lesions disappeared on follow-up imaging with clinical improvement.

CONCLUSIONS

Vasogenic edema plays an important role in the pathogenesis of WE and can be reversed by proper management. DWI findings in the early stage of WE may provide useful information about the prognosis.

Liquid chromatographic resolution of biphenyl dimethyl dicarboxylate (DDB) and its analogues on a chiral stationary phase

Racemic biphenyl dimethyl dicarboxylate (DDB) and its analogues have been successfully resolved on a commercial HPLC chiral column, (3R,4S)-Whelk-O 1. In general, cyclic amide analogues of DDB, which were derived from pyrrolidine or piperidine, showed greater enantioselectivity and greater retention than the corresponding N,N-dialkyl amide or N-alkyl amide or ester analogues. From these results, it was concluded that the carbonyl oxygen of the DDB analogues plays an important role as a hydrogen bond acceptor, though the steric bulkiness of the amide functionality of DDB analogues may be another factor governing chiral recognition. The conformational stability of the two enantiomers of DDB and its analogues was also found to be high enough for the two enantiomers to be resolvable on (3R,4S)-Whelk-O 1.

Synergy of Bacteroides fragilis and Escherichia coli in the induction of KC gene expression in mouse peritoneal tissues

B. fragilis induces cytokine expression, which can serve as a host signal leading to inflammatory reaction and abscess formation in the peritoneal cavity. We assessed the hypothesis that enteric bacteria may alter the B. fragilis-induced expression of KC genes in mouse peritoneal tissues (MPT). After C57BL/6 mice were inoculated with abscess-forming mixture containing B. fragilis in the presence or absence of E. coli, RNA was extracted from MPT. Expression of KC mRNA was quantified using reverse-transcription polymerase chain reaction and standard RNA. KC and TNFalpha proteins were measured by enzyme-linked immunosorbent assay. KC mRNA in MPT was upregulated following inoculation of B. fragilis and this was paralleled by increased KC protein secretion. When the mice were co-infected with E. coli and B. fragilis intraperitoneally, there was a synergistic increase in the expression of KC of MPT. Co-infection with L. acidophilus and B. fragilis downregulated KC mRNA expression, but co-infection with E. faecalis and B. fragilis synergistically increased KC expression in the infected MPT. Inhibition of TNFalpha production could downregulate KC expression in mixed infected MPT. These results suggest that enteric bacteria may significantly affect the KC signal produced by the host peritoneal cavity in response to B. fragilis infection.

A case of primary adenosquamous carcinoma of the liver presented with liver abscess

Primary adenosquamous carcinoma of the liver is a very rare type of cholangiocarcinoma and is defined as a cancer containing both squamous and adenomatous components in the same lesion. Recently, we experienced a primary adenosquamous carcinoma of the liver presented as liver abscess. A 63-year-old man was presented with a 4-day history of fever and chill. The radiologic study showed a 4 cm-sized, central hypoattenuated mass with peripheral rim enhancement in the left lobe of the liver. Ultrasonography-guided aspiration and biopsy suggested an adenocarcinoma with abscess in the liver. At laparotomy, the tumor occupied the left lobe of the liver and invaded the right diaphragm. An extended left lobectomy and a partial excision of the involved diaphragm were done. Grossly, the tumor was 6 x 5 x 5 cm in size and had an eccentric necrosis. Microscopically, the tumor was composed of adenocarcinoma and squamous cell carcinoma with a transitional area.

Nuclear factor-kappa B plays a major role in the regulation of chemokine expression of HeLa cells in response to Toxoplasma gondii infection

Toxoplasma gondii infection results in an infiltration of immune cells. The mechanisms responsible for triggering inflammatory cell infiltration in T. gondii infection are not fully understood. We report that T. gondii-infected HeLa cells induced nuclear factor-kappa B (NF-kappaB) activation and increased the expression of interleukin-8 (IL-8) and monocyte chemotactic protein-1 (MCP-1) mRNA. An inhibitor of NF-kappaB activation, calpain-1 inhibitor, blocked the chemokine secretion induced by live T. gondii. Activation of the IL-8 and NF-kappaB transcriptional reporters was suppressed in cells co-transfected with IkappaB kinase beta and the IkappaBalpha super-repressor plasmids. Moreover, the addition of IL-1alpha increased NF-kappaB activation and IL-8 mRNA expression in T. gondii-infected HeLa cells. These results suggest that NF-kappaB is a central regulator of the chemokine response in T. gondii-infected human epithelial cells and that chemokine IL-8 and MCP-1 secretion might be involved in the pathogenesis of T. gondii, via the recruitment of neutrophils, monocytes, and lymphocytes.

Association of p53 and BCL-2 expression with Epstein-Barr virus infection in the cancers of head and neck

BACKGROUND

Reports that have both evaluated the site-specific Epstein-Barr virus (EBV) infection and compared it with the expression of the EBV-related proto-oncogenes and tumor suppressor genes in the various cancers of head and neck are scarce.

METHODS

Thirty-eight nasopharyngeal carcinoma (NPC) cases, 32 oropharyngeal or hypopharyngeal carcinoma (OPC/HPC) cases, and 93 laryngeal carcinoma (LC) cases were evaluated with in situ hybridization on EBV-encoded small RNA (EBER) and immunohistochemical assessments of the p53, bcl-2, and epidermal growth factor receptor (EGFR) by use of formalin-fixed paraffin-embedded tissue array slides.

RESULTS

The expression of viral EBERs was observed in more than two thirds (71.1%) of the NPC cases. In contrast, only 1 case of OPC and none of the HPC or LC cases exhibited EBV positivity. In the nonkeratinizing NPC, the EBV positivity was significantly associated with both frequent p53 overexpression (p =.033) and bcl-2 expression (p =.001). In the EBV-positive nonkeratinizing NPC, a correlation between p53 overexpression and the tumor infiltration lymphocyte (TIL) density was noted (p =.012).

CONCLUSIONS

A site-specific expression of viral EBER was demonstrated in the head and neck cancers, which suggests an important role for both p53 and bcl-2 in the carcinogenesis of an EBV-infected NPC. The correlation between p53 overexpression and the TIL density in the EBV-infected NPC suggests that the product of a lymphoepithelial interaction, such as A20, can induce a dysfunctional p53 protein.

Requirement of de novo protein synthesis for aminopterin-induced apoptosis in a mouse myeloma cell line

Cells synthesize nucleotides through de novo and salvage pathways that require the activities of dihydrofolate reductase (DHFR) and hypoxanthine-guanine phosphoribosyltransfease (HGPRT), respectively. Aminopterin, an inhibitor of dihydrofolate reductase, has been demonstrated to allow HGPRT(-) cells to be negatively selected. However, the pathway by which aminopterin leads to cell death remains to be clarified. In this study, we characterized features of cellular responses induced by aminopterin treatment in P3-X63-Ag8.653, a mouse HGPRT(-) myeloma cell line. Upon treatment with aminopterin, the cells readily underwent an apoptotic process, as assessed by DNA fragmentation assay and electron microscopic analysis. Aminopterin-induced apoptosis was drastically reduced by addition of actinomycin D and cycloheximide, indicating that active RNA and protein synthesis is required for the apoptotic effect of aminopterin. Interestingly, the induction of c-myc gene expression preceded the activity of DNA fragmentation in aminopterin-treated cells. Taken together, these results suggest that cells deficient in the salvage pathway of purine biosynthesis are susceptible to aminopterin-induced apoptosis that requires de novo synthesis of proapoptotic factors, including Myc oncoprotein.

Differential display analysis of gene expression altered by ras oncogene

The goal of the signal transduction pathways, such as those controlled by Ras, is in large part to ensure highly stringent regulation of the target genes in the nucleus, which are collectively responsible for the signal output, or phenotypes, of the cell. Understanding of the Ras effect ultimately requires the identification of these downstream target genes. Reverse genetic approaches would trace back the pathways by which they are regulated by Ras. While newer methods such as DNA microarray are emerging, differential display has allowed the identification of a greater number of differentially expressed genes than have been cloned by all the other methods combined, based on Medline search. Much of this success has been attributed to its simplicity (RT-PCR and DNA-sequencing gel) and versatility (compare more than two RNAs for both up- and downregulated genes). It has become obvious that finding the genes by either differential display or DNA microarray is only the first step toward the understanding of biological problems under investigation. It is hoped that finding the right genes through careful experimental designs, such as outlined here, will narrow down the number of relevant genes and increase the odds for solving the puzzles of nature, such as ras.