Genomic Characterization of Locally Recurrent Prostate Cancer after Radiation Therapy

PURPOSE/OBJECTIVE(S)

Radiation therapy (RT) is a backbone of treatment for patients with prostate cancer (PCa). However, locally recurrent disease after definitive RT (i.e., radiorecurrent PCa) is not uncommon and is associated with a higher risk of distant metastases and death from PCa. While the genomic landscape of primary PCa is well-characterized, little is known regarding the genomic landscape of radiorecurrent PCa or how this compares to that of primary PCa. We hypothesized that the genomic landscape of radiorecurrent PCa differs significantly from primary PCa and that these differences have clinical relevance. We examined this hypothesis by performing whole exome sequencing (WES) of radiorecurrent PCa.

MATERIALS/METHODS

We identified 25 patients with radiorecurrent PCa with available post-RT tissue obtained from biopsy or radical prostatectomy, as well as germline tissue. The tumor and germline tissue for 19 patients successfully underwent WES. We identified genomic variants including single nucleotide variants (SNVs), insertions/deletions, and copy number alterations. Furthermore, we estimated the tumor mutational burden (TMB; number of nonsynonymous mutations per megabase [Mb]) and contribution of individual mutational signatures. We compared our samples to a publicly available large cohort of primary PCa (n = 680) to define genomic alterations unique to radiorecurrent PCa.

RESULTS

In the overall cohort of 25 patients, the RT modality included external beam RT (56%), brachytherapy (36%), and combination of both (8%). 40% of patients received upfront androgen deprivation therapy with RT. The median time to local recurrence was 6.5 years. For the 19 radiorecurrent patients with WES data, the median TMB was 2.7 mutations/Mb, which was significantly higher than the median TMB of 0.7 mutation/Mb for primary PCa (P = 0.002 after multivariable adjustment). Radiorecurrent PCa demonstrated an enrichment of short deletions, with a significantly higher deletion/SNV ratio compared to primary PCa (P = 0.006). TP53 was the most frequently mutated gene in radiorecurrent PCa (n = 6), and the TP53 mutation prevalence was significantly higher compared to primary PCa (32% vs 10%, P = 0.016 by Fisher's exact test). TP53 was also determined to be recurrently mutated using MutSigCV (Q = 0.0003). Additionally, 3 samples demonstrated evidence of whole genome doubling.

CONCLUSION

Radiorecurrent PCa has a distinct genomic profile compared to primary PCa, characterized by a higher TMB with an enrichment of short deletions as part of the mutational composition, which may be a scar of nonhomologous end joining subsequent to RT-induced DNA double-stranded breaks. In addition, TP53 mutations may be of functional consequence in radiorecurrent PCa. Further efforts are underway to examine other genomic features apparent in WES data, as well as perform whole transcriptome sequencing to provide complementary insights into radiorecurrent PCa.

Indications for Adjuvant Radiation after Radical Prostatectomy as Predicted by Artificial Intelligence-Derived Dominant Intraprostatic Lesion Volume

PURPOSE/OBJECTIVE(S)

In prostate cancer, PI-RADs scores of dominant intraprostatic lesions (DILs) in multi-parametric magnetic resonance imaging (mpMRI) are prognostic; however, their inter-observer agreement is only moderate. Artificial intelligence (AI) may be a powerful tool for prognostication by analyzing a large number of scans consistently in a short amount of time. This study investigated whether the DIL volume (DILvol) provided by an AI deep-learning segmentation algorithm could predict adverse findings at radical prostatectomy (RP), some of which could warrant adjuvant radiation therapy (RT).

MATERIALS/METHODS

We conducted a retrospective study of 185 consecutive patients with localized prostate cancer who underwent an endorectal coil, high B-value (> = 1000 s/mm2), 3-Tesla mpMRI followed by RP between 2015 and 2017. Using a previously trained deep learning nnUNet algorithm for providing DIL segmentations from patients treated with definitive RT, we segmented the DIL for the RP cohort. We evaluated the association of AI DILvol with the risks of adverse pathologic factors, including positive margins, pathologic T3 (pT3) disease, and pathologic Gleason (pGS8-10) disease, using separate univariate logistic regression models. We then included AI DILvol, pT3 (vs pT2), pGS8-10 (vs pGS6-7), margin status, and pre-RP PSA for predicting post-RP PSA values utilizing multivariate linear regression analysis. Finally, we included these same factors into a multivariate logistic regression analysis for predicting the risk of meeting adjuvant RT indications (PSA persistence post-RP > = 0.1 ng/mL or positive lymph nodes).

RESULTS

The median time between RP and post-PSA value was 1.6 months. The Pearson's correlation coefficient between AI and reference DILvol (sum of manually contoured PI-RADS 3-5 lesions) was 0.86 (p < 0.001). The Pearson's correlation coefficient between AI DILvol and pathologic tumor size was 0.63 (p < 0.001). Utilizing separate univariate logistic regression models, we found that AI DILvol was significantly associated with the risks of positive margins (OR 1.31 [1.10, 1.58]; p = 0.003), pT3 (OR 1.59 [95% CI: 1.30, 1.99]; p < 0.001), and pGS8-10 (OR 1.28 [1.07, 1.56]; p = 0.01). On multivariate linear regression, AI DILvol (0.27/mL [0.25, 0.29]; p < 0.001) was significantly correlated with post-RP PSA values, after controlling for adverse factors and pre-RP PSA. On multivariate logistic regression, AI DILvol (adjusted OR 1.32 [1.05, 1.69]; p = 0.03) was the only factor significantly associated with the risk of meeting adjuvant RT indications after controlling for these same factors.

CONCLUSION

For localized prostate cancer treated with RP, AI DILvol was the only factor significantly associated with the risk of meeting adjuvant RT indications, even after controlling for pathologic factors at RP. Further studies are needed to determine if AI DILvol is prognostic for long-term oncologic outcomes after RP.

Association between Artificial Intelligence-Derived Tumor Volume and Oncologic Outcomes for Localized Prostate Cancer Treated with Radiation Therapy

PURPOSE/OBJECTIVE(S)

Although clinical features of multi-parametric magnetic resonance imaging (mpMRI) have been associated with biochemical recurrence in localized prostate cancer, such features are subject to inter-observer variability. We evaluated whether the volume of the dominant intraprostatic lesion (DIL), as provided by a deep learning segmentation algorithm, could provide prognostic information for patients treated with definitive radiation therapy (RT).

MATERIALS/METHODS

We conducted a retrospective study of 438 patients with localized prostate cancer who underwent an endorectal coil, high B-value, 3-Tesla mpMRI and were treated with definitive RT at our institution between 2010 and 2017. We utilized the publicly available nnUNet to train a segmentation model which was used to identify the DIL. We examined the association between the artificial intelligence (AI)-generated DIL volume and oncologic outcomes, including biochemical recurrence and metastasis risk, using cause-specific Cox regression and time-dependent receiver operating characteristic analysis.

RESULTS

The AI model identified DILs with an area under the receiver operating characteristic (AUROC) of 0.827 at the patient level. For the 233 patients with available PI-RADS scores, with a median follow-up of 5.6 years, there were 28 biochemical failures. AI-defined DIL volume was significantly associated with biochemical failure (adjusted hazard ratio 1.60, 95% confidence interval 1.14-2.24, p = 0.007) after adjustment for PI-RADS score. Among all 438 patients with a median follow-up of 6.9 years, there were 49 biochemical failures and 22 metastases. The AUROC for predicting 7-year biochemical failure for AI volume (0.790) was similar to that for National Comprehensive Cancer Network (NCCN) category (p = 0.17). The AUROC for predicting 7-year metastasis for AI volume trended towards being higher compared to NCCN category (0.854 vs 0.769, p = 0.06).

CONCLUSION

An AI algorithm using deep learning could identify the DIL with good performance. AI-defined DIL volume may be able to provide prognostic information independent of the NCCN risk group or other radiologic factors for patients with localized prostate cancer treated with RT.

[Study on the related factors of antiviral treatment in previously reported hepatitis C patients based on the Andersen model]

Objective: To understand the basic characteristics of previously reported patients with hepatitis C and analyze the related factors affecting their antiviral treatment. Methods: A convenient sampling method was adopted. Patients who had been previously diagnosed with hepatitis C in the Wenshan Prefecture of Yunnan Province and Xuzhou City of Jiangsu Province were contacted by telephone for an interview study. The Andersen health service utilization behavior model and related literature were used to design the research framework for antiviral treatment in previously reported hepatitis C patients. A step-by-step multivariate regression analysis was used in previously reported hepatitis C patients treated with antiviral therapy. Results: A total of 483 hepatitis C patients, aged 51.73 ± 12.06 years, were investigated. The proportion of male, agricultural occupants who were registered permanent residents, farmers and migrant workers was 65.24%, 67.49%, and 58.18%, respectively. Han ethnicity (70.81%), married (77.02%), and junior high school and below educational level (82.61%) were the main ones. Multivariate logistic regression analysis results showed that married patients with hepatitis C (OR = 3.19, 95% CI: 1.93-5.25, compared with unmarried, divorced, and widowed patients) with high school education or above (OR = 2.54, 95% CI: 1.54-4.20, compared with patients with junior high school education or below) were more likely to receive antiviral treatment in the predisposition module. Patients with severe self-perceived hepatitis C in the need factor module (compared with patients with mild self-perceived disease, OR = 3.36, 95% CI: 2.09-5.40) were more likely to receive treatment. In the competency module, the family's per capita monthly income was more than 1,000 yuan (compared with patients with per capita monthly income below 1,000 yuan, OR = 1.59, 95% CI: 1.02-2.47), and the patients had a high level of awareness of hepatitis C knowledge (compared with patients with a low level of knowledge, OR = 1.54, 95% CI: 1.01-2.35), and the family members who knew the patient's infection status (compared with patients with an unknown infection status, OR = 4.59, 95% CI: 2.24-9.39) were more likely to receive antiviral treatment. Conclusion: Different income, educational, and marital statuses are related to antiviral treatment behavior in hepatitis C patients. Family support of hepatitis C patients receiving hepatitis C-related knowledge and their families knowing the infection status is more important in promoting the antiviral treatment of patients, suggesting that in the future, we should further strengthen the hepatitis C knowledge of hepatitis C patients, especially the family support of hepatitis C patients' families in treatment.

[Safety and efficacy of high-power, short-duration superior vena cava isolation in combination with conventional radiofrequency ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial]

Objective: For patients with paroxysmal atrial fibrillation, superior vena cava isolation on the basis of pulmonary vein isolation may further improve the long-term success rate of radiofrequency ablation. We aimed to explore the efficacy and safety of superior vena cava isolation by high-power and short-duration (HPSD) ablation plus conventional radiofrequency ablation (RA) in patients with paroxysmal atrial fibrillation. Methods: It was a prospective randomized controlled study. From January 1, 2019 to June 1, 2020, 180 patients who underwent radiofrequency ablation for paroxysmal atrial fibrillation in our center were consecutively screened. Patients were eligible if there was a trigger potential and the muscle sleeve length was greater than 3 cm. A total of 60 eligible patients were finally included and randomly divided into HPSD group (HPSD plus RA) and common power and duration (CPD) group (CPD plus RA) by random number table method (n=30 in each group). Efficacy was evaluated by ablation points, isolation time and ablation time. Safety was evaluated by the incidence of POP, cardiac tamponade, phrenic nerve injury, sinoatrial node injury and all-cause. Results: Superior vena cava isolation was achieved by 14 (13, 15) points in the HPSD group, which was significantly less than that in the CPD group (20(18, 22), P<0.001). The superior vena cava isolation time was 8 (7, 9) minutes in the HPSD group, which was significantly shorter than in the CPD group (17(14, 20) minutes, P<0.001). The average ablation time significantly shorter in HPSD group than in CPD group (78.0(71.1, 80.0) s vs. 200(167.5, 212.5)s, P<0.001). The average impedance drop was more significant in the HPSD group than in the CPD group (20.00(18.75, 21.00)Ω (and the percentage of impedance drop was 15%) vs. 12.00(11.75, 13.25)Ω (the percentage of impedance decrease was 12%), P<0.001). There was 1 POP (3.3%) in the HPSD group, and 3 POPs (10.0%) in the CPD group (P>0.05). There was no cardiac tamponade, phrenic nerve injury, sinoatrial node injury and death in both groups. Conclusions: HPSD technique for the isolation of superior vena cava is safe and effective in patients with paroxysmal atrial fibrillation undergoing conventional radiofrequency ablation.

[Mechanism of human airway epithelial cell injury induced by Candida albicans infection]

Objective: To investigate the immune mechanism of human airway epithelial cell injury induced by invasion of Candida albicans with different biofilm formation abilities. Methods: Twenty-five strains of Candida albicans isolated and cultured in General Hospital of Ningxia Medical University from June to December 2019 were selected, and quality control strain SC5314 was used as the standard strain. An in vitro model of Candida albicans biofilm was established, and the biofilm formation ability of different Candida albicans was detected by crystal violet staining and enzyme plate method. The absorbance value at 570 nm (A₅₇₀) was determined by enzyme plate method. A₅₇₀≥0.5, 0.25<A₅₇₀<0.5 and A₅₇₀≤0.25 indicated strong biofilm Candida albicans form (SBF), moderate biofilm Candida albicans form (DRF) and weak biofilm Candida albicans form (WBF), respectively. The gas-liquid phase culture model of human airway epithelial cells was isolated and established in vitro and divided into five groups, including blank control group (n=20), standard strain group (n=20), strong biofilm group (n=19), weak biofilm group (n=17) and fluconazole-resistant group (n=18).The morphology of the epithelial cells was observed by scanning electron microscope (SEM), and the expression of marker protein in the model was detected by immunofluorescence in vitro. The level of lactate dehydrogenase (LDH) in cells was detected by microplate method, and the secretion of β-defensin (hBD2), granulocyte macrophage colony stimulating factor(GM-CSF) and granulocyte colony-stimulating factor (G-CSF) was detected by enzyme-linked immunosorbent assay (ELISA). Results: The strong biofilm strains grew with interlacing mycelia, and very few yeast cells could be seen wrapped in them.SEM observed that the mycelia of epithelial cells in gas-liquid phase culture could actively invade epithelial cells, and the expression of acetylated tubulin and keratin in cilia were significantly reduced, while the expression of Ki67 was down-regulated.The LDH levels in the blank control group, standard strain group, strong biofilm group, weak biofilm group, and fluconazole-resistant group were (12.21±5.68), (46.35±6.35), (18.69±4.38), (12.56±3.69), and (13.48±4.28) U/L, respectively, with statistically significant differences (P<0.001). Compared with standard strain group, LDH level in strong biofilm group, weak biofilm group and fluconazole resistant group were significantly decreased (all P<0.01). The hBD2 levels of the five groups were (26.14±0.77), (56.18±0.83), (30.66±2.59), (29.22±0.48), (28.28±1.56) ng/L, respectively, with statistically significant differences(P<0.001). Compared with the blank control group, SC5314-treated epithelial cells induced an increase of intracellular hBD2 expression (P<0.001). The differences in the expression of GM-CSF and G-CSF between different groups were not statistically significant(all P>0.05). Conclusion: Strong biofilm Candida albican can inhibit cell proliferation, disrupt the integrity of epithelial cells and induce cell damage by down-regulating the expression of cell proliferation-related protein.

[Investigation on the current situation of safety protection of medical staffs for the prevention and treatment of infectious diseases in medical institutions in Jiangsu Province]

Objective: To investigate the current situation of safety protection of medical staffs in medical institutions in Jiangsu Province, and to provide scientific basis for strengthening the safety protection of infectious diseases and protecting the occupational health of medical staffs. Methods: From September to October 2020, 1274 medical staffs in 43 medical and health institutions were randomly selected as the subjects. The self-made questionnaire for infectious disease prevention and protection was used to analyze the pre-job training and exposure to occupational harmful factors of the respondents. The influencing factors of using protective equipment and occupational injury were analyzed by binary logistic regression. Results: A total of 1216 valid questionnaires were collected with effective recovery of 95.4%. There were 312 males (25.7%) and 904 females (74.3%) , with an average age of (35.8±9.2) years and average working years of (13.6±9.9) years. Among them, 1143 (94.0%) had participated in pre-job training, 535 (44.0%) thought they were exposed to occupational harmful factors of infectious disease prevention, 1082 (89.0%) used protective equipment in daily operation, and 462 (38.0%) had occupational injury. According to binary logistic regression analysis, the utilization rates of protective equipment for medical staffs in Centers for Disease Control and Prevention (OR=2.473, 95%CI: 1.327-4.607, P=0.004) , 30-39 years old (OR=1.586, 95%CI: 1.038-2.426, P=0.033) , 40-49 years old (OR=2.257, 95%CI: 1.243-4.098, P=0.007) , 50 years old and above (OR=5.879, 95% CI: 1.755-19.692, P=0.004) and pre-job training (OR=2.580, 95%CI: 1.301-5.116, P=0.007) were higher than their respective control groups. And medical staffs with graduate degree or above (OR=0.342, 95%CI: 0.167~0.699, P=0.003) had lower utilization rate of protective equipment. Female (OR=1.902, 95%CI: 1.364-2.654, P<0.001) , 30-39 years old (OR=1.589, 95%CI: 1.157-2.181, P=0.004) , bachelor degree (OR=2.070, 95%CI: 1.419-3.021, P<0.001) , exposure to occupational harmful factors (OR=2.753, 95%CI: 2.086-3.634, P<0.001) were the risk factors for occupational injury of medical staffs. Centers for Disease Control and Prevention (OR=0.129, 95%CI: 0.086-0.194, P<0.001) and wearing protective equipment according to regulations (OR=0.597, 95%CI: 0.431-0.827, P=0.002) were the protective factors for occupational injury of medical staffs. Conclusion: At present, the occupational injury rate of medical staffs in Jiangsu Province is high due to various factors in the prevention and control of infectious diseases. It is necessary to pay attention to occupational safety protection, strengthen pre-job training and actively advocate "standard prevention", so as to reduce the exposure risk of harmful factors and promote occupational health of medical staffs.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Trends in malignant melanoma mortality in 31 countries from 1985 to 2015

BACKGROUND

Malignant melanoma (MM) causes the highest absolute number of deaths among skin cancers. An up-to-date analysis of international MM mortality trends is required for assessing the burden of disease, and may support the assessment of the effectiveness of new diagnostic, therapeutic and preventative strategies.

OBJECTIVES

To report MM mortality trends between 1985 and 2015 using the World Health Organization (WHO) Mortality Database.

MATERIALS AND METHODS

We used country-level MM mortality data from the WHO Mortality Database for all countries with high usability death registration data. Mortality trends were described using Joinpoint regression modelling.

RESULTS

Thirty-one countries met the inclusion criteria. All countries, except the Czech Republic, demonstrated increased age-standardized death rates (ASDRs) in males over the observation period. More countries exhibited decreased or stable MM mortality in females. The median mortality rate for 2013-2015 was 2·57 deaths per 100 000 for males and 1·55 per 100 000 for females. Australia and Norway had the highest ASDRs for males (5·72 per 100 000 and 4·55 per 100 000, respectively). Norway and Slovenia had the highest ASDRs for females (3·02 per 100 000 and 2·58 per 100 000, respectively). MM mortality was greater for males than females in all countries, with sex disparity increasing across the period. Disparity in mortality between older and younger cohorts in several countries was also found.

CONCLUSIONS

An overall increase in MM mortality over the past 30 years was observed. However, there was notable variation in mortality trends between countries, as well as between males and females, and between different age groups.

NiS2 nanoparticles anchored on open carbon nanohelmets as an advanced anode for lithium-ion batteries

Low intrinsic conductivity and large volume expansion seriously restrict the efficient lithium storage performance of metal sulfides. Here, we fabricate a hybrid material of NiS₂ nanoparticles/carbon nanohelmets (NiS₂/CNHs) to address the above issues. As an anode material in lithium-ion batteries, NiS₂/CNHs exhibit excellent cycling stability (490 mA h g^-1 after 3000 cycles at 5 A g^-1) and rate properties (412 mA h g^-1 at 10 A g^-1), outperforming other NiS _x -based anode materials. These remarkable performances originate from the three-dimensional helmet-like integrated architecture of NiS₂/CNHs, which reduces the electrode resistance due to the tight combination between NiS₂ and CNHs, provides efficient diffusion paths for the electrolyte and Li⁺ owing to the amorphous nanoporous carbon structure, and significantly mitigates the aggregation and buffers the large volumetric expansion of NiS₂ nanoparticles upon long-term cycling thanks to the open three-dimensional architecture and well-dispersed NiS₂ nanoparticles on it.

[Investigation of emergency capacities for occupational hazard accidents in silicon solar cell producing enterprises]

Objective: To investigate and analyze the influential factors of occupational hazard acci-dents, emergency facilities and emergency management in Silicon solar cell producing enterprises, then to pro-vide scientific strategies. Methods: The methods of occupationally healthy field investigating, inspecting of ven-tilation effectiveness, setup of emergency program and wearing chemical suit were used. Results: The mainly occupational hazard accidents factors in the process of Silicon solar cell producing included poisoning chemi-cals, high temperature, onizing radiation and some workplaces. The poisoning chemicals included nitric acid, hydrofluoric acid, sulfuric acid, hydrochloric acid, sodium hydroxide, potassium hydroxide, chlorine, phos-phorus oxychloride, phosphorus pentoxide, nitrogen dioxide, ammonia, silane, and so on; the workplaces in-cluded the area of producing battery slides and auxiliary producing area. Among the nine enterprises, gas detec-tors were installed in special gas supplying stations and sites, but the height, location and alarmvalues of gas detectors in six enterprises were not according with standard criteria; emergency shower and eyewash equip-ment were installed in workplaces with strong corrosive chemicals, but the issues of waste water were not solved; ventilation systems were set in the workplaces with ammonia and silane, but not qualified with part lo-cations and parameters in two enterprises; warehouses with materials of acid, alkali, chemical ammonia and phosphorus oxychloride were equipped with positive - pressure air respirator resuscitator and emergency cabi-nets, but with insufficient quantity in seven enterprises and expiration in part of products. The error rate of set-up emergency program and wearing chemical cloth were 30%~100% and 10%~30%, respectively. Among the nine enterprises, there were emergency rescue plans for dangerous chemical accidents, but without profession-al heatstroke and irradiation accident emergency plans, lack of archives of descripting and evaluating for pro-cessing in emergency exercises as well. There were emergency rescue agreements between enterprises and medi-cal institutions which varied in occupational poisoning rescue capacities and were lack of training and exercise regularly. Conclusion: There were a variety of occupational hazard factors in Silicon solar cell producing enter-prises including potential chemical burns, acute poisoning, occupational heatstroke, accident risk of ionizing radiation, and we must strengthen the management of emergency rescue for Silicon solar cell producing enter-prises.

Risk factors for pulmonary hypertension in patients receiving maintenance peritoneal dialysis

We investigated the risk factors for pulmonary hypertension (PH) in patients receiving maintenance peritoneal dialysis (MPD). A group of 180 end-stage renal disease patients (124 men and 56 women; mean age: 56.43±8.36) were enrolled in our study, which was conducted between January 2009 and June 2014. All of the patients received MPD treatment in the Dialysis Center of the Second Affiliated Hospital of Soochow University. Clinical data, laboratory indices, and echocardiographic data from these patients were collected, and follow-ups were scheduled bi-monthly. The incidence and relevant risk factors of PH were analyzed. The differences in measurement data were compared by t-test and enumeration data were compared with the χ2 test. Among the 180 patients receiving MPD, 60 were diagnosed with PH. The remaining 120 were regarded as the non-PH group. Significant differences were observed in the clinical data, laboratory indices, and echocardiographic data between the PH and non-PH patients (all P<0.05). Furthermore, hypertensive nephropathy patients on MPD showed a significantly higher incidence of PH compared with non-hypertensive nephropathy patients (P<0.05). Logistic regression analysis showed that the proportion of internal arteriovenous fistula, C-reactive protein levels, and ejection fraction were the highest risk factors for PH in patients receiving MPD. Our study shows that there is a high incidence of PH in patients receiving MPD and hypertensive nephropathy patients have an increased susceptibility to PH.

Effects of CD3McAb and rhIL-2 activated bone marrow on the killing and purging of leukemia cells

We investigated the roles of CD3McAb and rhIL-2 activated bone marrow in the killing and purging of leukemia cells. Cytotoxicity of activated bone marrow was detected with MTT assay. CFU-GM level in activated bone marrow and the destruction of leukemia cells were measured using the semi-solid cell culture. Immune activation markers in activated bone marrow were detected by indirect immunofluorescence assay. Bone marrow activated by CD3McAb and rhIL-2 displayed significantly upregulated the killing and purging abilities on the leukemia cell line K562 and HL-60. Such effects were superior to that of bone marrow activated by rhIL-2 or CD3McAb alone (P < 0.05, P < 0.01). Activation by rhIL-2 and (or) CD3McAb exerted no obvious influence on CFU-GM level in bone marrow. Compared with bone marrow activated by rhIL-2 or CD3McAb alone, the synergistic effect of both CD3McAb+ and hIL-2 caused significant increase of CD3(+), CD8(+), CD19(+), CD25(+), CD38(+), and CD56(+) levels. Our study indicates that CD3McAb enhanced the killing and purging effects of rhIL-2 activated bone marrow on leukemia cells.

Changes in spatial distribution of flexor digitorum superficialis muscle activity is correlated to finger's action

Multitendoned extrinsic muscles of the human hand can be divided into several neuromuscular compartments (NMCs), each of which contributes to the ability of human finger to produce independent finger movements or force. The aim of this study was to investigate the changes in the spatial activation of flexor digitorum superficialis (FDS) during the fingertip force production with non-invasive multichannel surface electromyography (sEMG) technique. 7 healthy Subjects were instructed to match the target force level for 5s using individual index finger (I), individual middle finger (M) and the combination of the index and middle finger (IM) respectively. Simultaneously, a 2 × 6 electrode array was employed to record multichannel sEMG from FDS as finger force was produced. The entropy and center of gravity of the sEMG root mean square (RMS) map were computed to assess the spatial inhomogeneity in muscle activation and the change in spatial distribution of EMG amplitude related to the force generation of specific task finger. The results showed that the area and intensity of high amplitude region increased with force production, and the entropy increased with force level under the same task finger. The findings indicate that the change of spatial distribution of multitendoned extrinsic hand muscle activation is correlated to specific biomechanical functions.

Absence of cocaine- and amphetamine-regulated transcript results in obesity in mice fed a high caloric diet

Cart (cocaine- and amphetamine-regulated transcript) was first identified to be a major brain mRNA up-regulated by cocaine and amphetamine. The CART protein has been established as a satiety factor closely associated with the action of leptin. To assess CART's role as an anorexigenic signal, we have generated CART-deficient mice by gene targeting. On a high fat diet, CART-deficient and female heterozygous mice, but not male heterozygous mice, showed statistically significant increases in weekly food consumption, body weight, and fat mass compared with their wild-type littermates. Furthermore, CART-deficient and female heterozygous mice were significantly heavier when fed a high fat diet than on a regular chow diet at 17 wk of age and at the 14th wk of the feeding studies. However, wild-type or male heterozygous mice showed no weight variations attributable to caloric contents of the diet at that age. Contrary to the obese phenotypes shown in MC4R-, proopiomelanocortin-, or leptin-deficient mice, our results showed that CART deficiency predisposed mice to become obese on a calorically dense diet. The results also show that CART may not be a major anorectic signal compared with proopiomelanocortin or leptin in the regulation of energy homeostasis.

Enhanced CD4+ T cell proliferation and Th2 cytokine production in DR6-deficient mice

We have found that DR6, a member of the TNF receptor family, is highly expressed in resting T cells and downregulated in activated T cells. DR6-targeted mutant mice were generated and showed normal development. However, DR6(-/-) CD4(+) T cells hyperproliferated in response to TCR-mediated stimulation and protein antigen challenge. Activated DR6(-/-) CD4(+) T cells exhibited upregulated CD25 expression and enhanced proliferation in response to exogenous IL-2 stimulation. In addition, increased CD28 and reduced CTLA-4 expression were observed in these cells. Enhanced Th2 cytokine production by activated DR6(-/-) CD4(+) T cells was associated with the increased transcription factor NF-ATc in nuclei. DR6, therefore, functions as a regulatory receptor for mediating CD4(+) T cell activation and maintaining proper immune responses.

Molecular basis of T-cell differentiation

In summary, a multitude of regulatory systems are employed to cause the selective activation of target cytokine genes in Th1 and Th2 effector cells. These mechanisms involve both positive and negative regulation and employ at least three kinds of mechanisms. In the first, selective expression of transcription factors such as GATA3 in Th2 cells and the homeobox gene HLX in Th1 cells occurs, and appears in both cases to play a causal role. Another example of this would be c-maf, discovered by the Glimcher laboratory. A second mechanism is by the selective accumulation of protein through posttranscriptional mechanisms. Thus, junB accumulates in Th2 cells despite the fact that the junB mRNA levels are not different between Th1 and Th2 cells. Finally, the selective use of signaling pathways, in the case studied here MAP kinase pathways, leads to the selective activation of target genes. We believe that transcriptional up-regulation of rac2 leads to the coupling of both the p38 and JNK MAP kinase pathways to the T-cell receptor and/or costimulatory receptors, thereby providing a lineage-specific signal.

JNK1 is required for T cell-mediated immunity against Leishmania major infection

c-Jun N-terminal kinase (JNK) is a mitogen-activated protein kinase that plays important regulatory roles in helper T cell differentiation. In the current study, we used Jnk1-deficient mice to examine the function of JNK during an in vivo pathogenic infection, leishmaniasis, which is strongly influenced by Th1/Th2 effector mechanisms. The data show that Jnk1-deficient mice, despite their usually genetically resistant background, were unable to resolve Leishmania infections. Jnk1-/- mice displayed reduced delayed-type hypersensitivity in response to the pathogen, which was associated with a T cell defect. We found that, although these mice can direct an apparent Th1-response, there is also simultaneous generation of Leishmania-specific Th2 responses, which possibly down-modulate protective Th1-mediated immune function. These findings demonstrate that the negative regulation of Th2 cytokine production by the JNK1 signaling pathway is essential for generating Th1-polarized immunity against intracellular pathogens, such as Leishmania major.

Requirement of JNK for stress-induced activation of the cytochrome c-mediated death pathway

The c-Jun NH2-terminal kinase (JNK) is activated when cells are exposed to ultraviolet (UV) radiation. However, the functional consequence of JNK activation in UV-irradiated cells has not been established. It is shown here that JNK is required for UV-induced apoptosis in primary murine embryonic fibroblasts. Fibroblasts with simultaneous targeted disruptions of all the functional Jnk genes were protected against UV-stimulated apoptosis. The absence of JNK caused a defect in the mitochondrial death signaling pathway, including the failure to release cytochrome c. These data indicate that mitochondria are influenced by proapoptotic signal transduction through the JNK pathway.

JNK is required for effector T-cell function but not for T-cell activation

The hallmark of T-cell activation is the production of interleukin 2 (IL-2). c-Jun amino-terminal kinase (JNK), a MAP kinase that phosphorylates c-Jun and other components of the AP-1 group of transcription factors, has been implicated in the activation of IL-2 expression. Previously, we found that T cells from mice deficient in the Jnk1 or Jnk2 gene can be activated and produce IL-2 normally, but are deficient in functional differentiation into Th1 or Th2 subsets. However, studies of mice with compound mutations indicate that JNK1 and JNK2 are redundant during mouse development. Here we use three new mouse models in which peripheral T cells completely lack JNK proteins or signalling, to test whether the JNK signalling pathway is crucial for IL-2 expression and T-cell activation. Unexpectedly, these T cells made more IL-2 and proliferated better than wild-type cells. However, production of effector T-cell cytokines did require JNK. Thus, JNK is necessary for T-cell differentiation but not for naive T-cell activation.

Effects of dihydroartemisinin on fine structure of erythrocytic stages of Plasmodium berghei ANKA strain

AIM

The fine structural changes of Plasmodium berghei ANKA strain after treatment with the dihydroartemisinin (DATM) were observed.

METHODS

DATM 180 mg.kg-1.d-1 was given ig to outbreed NIH mice infected with P. berghei ANKA strain. Blood samples were collected, embedded and examined by electron microscopy.

RESULTS

In P. berghei ANKA strain, 1 h after drug administration, the parasites food vacuole membranes were destroyed, and the pigment grains showed some changes. The nucleus membrane, cytomembrane, and food vacuole membranes were stratified 2 h after administration. At the same time, swelling and separation of the outer and inner membrane or shrinking of the mitochondria were seen. Stripped nuclear and cytoplasm membrane were developed and vacuolizations were seen 4 h later. Eight hours after administration, a large number of parasite structures were destroyed except for a few parasite autophagic vacuoles.

CONCLUSION

DATM was a fast-acting and effective antimalarial drug. Its primary target is the membrane system. No obvious resistant characteristics were found upto 24 generations after resistant induction test for 4 months.

Selective expression of JNK isoforms and stress-specific JNK activity in different neural cell lines

The function of c-Jun N-terminal kinases (JNKs) in the nervous system is poorly understood and the majority of the data has been gained in neuronal and non-neuronal cell lines. Thus, it is not clear to which extent the expression pattern and the degree of activation of the three JNK isoforms in different cell lines are representative for their activation in the adult brain. In the present study, the expression of JNK isoforms and the activity of JNK1 were determined following UV irradiation and exposure to H(2)O(2) and TNFalpha in three neural cell lines, rat PC12, murine Neuro2A and human SHSY5Y. These cell lines differ in their expression of JNK isoforms: PC12 cells express JNK1 and JNK2, whereas Neuro2A and SHSY5Y cells displays the expression of JNK1, JNK2 and JNK3. JNK3 was not inducible following stress and differentiation in PC12 cells. The stimulation paradigms evoked different degree of cell death: UV irradiation resulted in death of around 50% in all three cell lines; exposure to 200 microM H(2)O(2) for 6 h resulted in the death of 43% Neuro2A cells and 31% PC12 cells, SHSY5Y cells are less sensitive to H(2)O(2) since only 5 mM H(2)O(2) killed 59% of SHSY5Y cells after 6 h. Exposure to 50 ng/ml TNFalpha did not induce cell death in SHSY5Y, Neuro2A and naive PC12 cells. Although differentiated PC12 cells exhibit a similar activation of JNK1 compared to naive PC12 cells after exposure to TNFalpha, 42% of differentiated PC12 cells died after 24 h. H(2)O(2) that evoked only a moderate JNK1 activity in Neuro2A and PC12 cells induced only a moderate cell death. In contrast, SHSY5Y cells exhibit a much stronger JNK1 activation accompanied with a higher degree in cell death after exposure to H(2)O(2). JNK1 activity induced by UV irradiation, however, could not be correlated with the extend of cell death. These data clearly demonstrate that expression and activation of JNK depends on the neuronal cell type and the applied stress paradigms, and that JNK activity is not simply linked to cell death.

Defective IL-12 production in mitogen-activated protein (MAP) kinase kinase 3 (Mkk3)-deficient mice

The p38 mitogen-activated protein kinase (MAPK) pathway, like the c-Jun N-terminal kinase (JNK) MAPK pathway, is activated in response to cellular stress and inflammation and is involved in many fundamental biological processes. To study the role of the p38 MAPK pathway in vivo, we have used homologous recombination in mice to inactivate the Mkk3 gene, one of the two specific MAPK kinases (MAPKKs) that activate p38 MAPK. Mkk3(-/-) mice were viable and fertile; however, they were defective in interleukin-12 (IL-12) production by macrophages and dendritic cells. Interferon-gamma production following immunization with protein antigens and in vitro differentiation of naive T cells is greatly reduced, suggesting an impaired type I cytokine immune response. The effect of the p38 MAPK pathway on IL-12 expression is at least partly transcriptional, since inhibition of this pathway blocks IL-12 p40 promoter activity in macrophage cell lines and IL-12 p40 mRNA is reduced in MKK3-deficient mice. We conclude that the p38 MAP kinase, activated through MKK3, is required for the production of inflammatory cytokines by both antigen-presenting cells and CD4(+) T cells.

The Jnk1 and Jnk2 protein kinases are required for regional specific apoptosis during early brain development

The c-Jun NH2-terminal kinase (Jnk) family is implicated in apoptosis, but its function in brain development is unclear. Here, we address this issue using mutant mice lacking different members of the family (Jnk1, Jnk2, and Jnk3). Mice deficient in Jnk1, Jnk2, Jnk3, and Jnk1/Jnk3 or Jnk2/Jnk3 double mutants all survived normally. Compound mutants lacking Jnk1 and Jnk2 genes were embryonic lethal and had severe dysregulation of apoptosis in brain. Specifically, there was a reduction of cell death in the lateral edges of hindbrain prior to neural tube closure. In contrast, increased apoptosis and caspase activation were found in the mutant forebrain, leading to precocious degeneration. These results suggest that Jnk1 and Jnk2 regulate region-specific apoptosis during early brain development.

Requirement of mitogen-activated protein kinase kinase 3 (MKK3) for tumor necrosis factor-induced cytokine expression

The p38 mitogen-activated protein kinase is activated by treatment of cells with cytokines and by exposure to environmental stress. The effects of these stimuli on p38 MAP kinase are mediated by the MAP kinase kinases (MKKs) MKK3, MKK4, and MKK6. We have examined the function of the p38 MAP kinase signaling pathway by investigating the effect of targeted disruption of the Mkk3 gene. Here we report that Mkk3 gene disruption caused a selective defect in the response of fibroblasts to the proinflammatory cytokine tumor necrosis factor, including reduced p38 MAP kinase activation and cytokine expression. These data demonstrate that the MKK3 protein kinase is a critical component of a tumor necrosis factor-stimulated signaling pathway that causes increased expression of inflammatory cytokines.

Defective T cell differentiation in the absence of Jnk1

The c-Jun NH2-terminal kinase (JNK) signaling pathway has been implicated in the immune response that is mediated by the activation and differentiation of CD4 helper T (TH) cells into TH1 and TH2 effector cells. JNK activity observed in wild-type activated TH cells was severely reduced in TH cells from Jnk1-/- mice. The Jnk1-/- T cells hyperproliferated, exhibited decreased activation-induced cell death, and preferentially differentiated to TH2 cells. The enhanced production of TH2 cytokines by Jnk1-/- cells was associated with increased nuclear accumulation of the transcription factor NFATc. Thus, the JNK1 signaling pathway plays a key role in T cell receptor-initiated TH cell proliferation, apoptosis, and differentiation.

The JNK pathway regulates the In vivo deletion of immature CD4(+)CD8(+) thymocytes

The extracellular signal-regulated kinase (ERK), the c-Jun NH2-terminal kinase (JNK), and p38 MAP kinase pathways are triggered upon ligation of the antigen-specific T cell receptor (TCR). During the development of T cells in the thymus, the ERK pathway is required for differentiation of CD4(-)CD8(-) into CD4(+)CD8(+) double positive (DP) thymocytes, positive selection of DP cells, and their maturation into CD4(+) cells. However, the ERK pathway is not required for negative selection. Here, we show that JNK is activated in DP thymocytes in vivo in response to signals that initiate negative selection. The activation of JNK in these cells appears to be mediated by the MAP kinase kinase MKK7 since high levels of MKK7 and low levels of Sek-1/MKK4 gene expression were detected in thymocytes. Using dominant negative JNK transgenic mice, we show that inhibition of the JNK pathway reduces the in vivo deletion of DP thymocytes. In addition, the increased resistance of DP thymocytes to cell death in these mice produces an accelerated reconstitution of normal thymic populations upon in vivo DP elimination. Together, these data indicate that the JNK pathway contributes to the deletion of DP thymocytes by apoptosis in response to TCR-derived and other thymic environment- mediated signals.

Differentiation of CD4+ T cells to Th1 cells requires MAP kinase JNK2

Precursor CD4+ T cells develop into effector Th1 and Th2 cells that play a central role in the immune response. We show that the JNK MAP kinase pathway is induced in Th1 but not in Th2 effector cells upon antigen stimulation. Further, the differentiation of precursor CD4+ T cells into effector Th1 but not Th2 cells is impaired in JNK2-deficient mice. The inability of IL-12 to differentiate JNK2-deficient CD4+ T cells fully into effector Th1 cells is caused by a defect in IFNgamma production during the early stages of differentiation. The addition of exogenous IFNgamma during differentiation restores IL-12-mediated Th1 polarization in the JNK2-deficient mice. The JNK MAP kinase signaling pathway, therefore, plays an important role in the balance of Th1 and Th2 immune responses.

Absence of excitotoxicity-induced apoptosis in the hippocampus of mice lacking the Jnk3 gene

Excitatory amino acids induce both acute membrane depolarization and latent cellular toxicity, which often leads to apoptosis in many neurological disorders. Recent studies indicate that glutamate toxicity may involve the c-Jun amino-terminal kinase (JNK) group of mitogen-activated protein (MAP) kinases. One member of the JNK family, Jnk3, may be required for stress-induced neuronal apoptosis, as it is selectively expressed in the nervous system. Here we report that disruption of the gene encoding Jnk3 in mice caused the mice to be resistant to the excitotoxic glutamate-receptor agonist kainic acid: they showed a reduction in seizure activity and hippocampal neuron apoptosis was prevented. Although application of kainic acid imposed the same level of noxious stress, the phosphorylation of c-Jun and the transcriptional activity of the AP-1 transcription factor complex were markedly reduced in the mutant mice. These data indicate that the observed neuroprotection is due to the extinction of a Jnk3-mediated signalling pathway, which is an important component in the pathogenesis of glutamate neurotoxicity.

Familial neurofibromatosis 1 with germinoma involving the basal ganglion and thalamus

Intracranial germinoma associated with neurofibromatosis 1 (NF-1) has never been documented previously. We report a case of familial NF-1 with a germinoma involving the right basal ganglion and thalamus. A 12-year-old boy presented with multiple café-au-lait spots and a family history of neurofibromatosis in his mother, one of two siblings, and his maternal grandfather. His intracranial lesion was subtotally resected. Histologically, it was a pure germinoma. Serum alpha-feto protein and beta-human chorionic gonadotropin levels were within the normal range. Postoperative myelographic examination and cerebrospinal fluid cytology study showed no evidence of subarachnoid seeding. The patient received postoperative combination chemotherapy resulting in complete response and clearance of the residual tumor. Although this finding of an intracranial germinoma in a patient with familial NF-1 may be coincident, it is suggestive of a potential genetic predisposition. Longitudinal evaluation for the possibility of neoplasm, especially germ cell tumor, in basal ganglion lesions in NF-1 patients is necessary.

Saturation of second-harmonic generation in GaAs-AlGaAs asymmetric quantum wells

The saturation of second-harmonic generation is observed for the first time to our knowledge in GaAs-GaAlAs asymmetric quantum wells. The sample, which consists of 200 periods of a 30-nm Ga(0.6)Al(0.4)As barrier, a 4.5-nm Ga(0.4)Al(0.09)As step barrier, and a 6-nm GaAs well, is pumped by a CO(2) TEA laser. The saturation of second-harmonic conversion is found to occur near 16 MW/cm(2). The power conversion efficiency is measured to be of the order of 3.4 x 10(-4). These results are in good agreement with theoretical predictions from a density matrix treatment.

Base sequence selectivity in binding of aromatic hydrocarbons with synthetic polynucleotides

The interactions between DOBP (3) and calf thymus DNA as well as four synthetic polynucleotides, poly(dA-dT), polydA:polydT, poly(dG-dC), and polydG:polydC, were investigated by spectroscopic techniques. It was found that the binding of 3 with poly(dA-dT) is favored appreciably over other synthetic polynucleotides and DNA. The results suggest that the initial association of carcinogenic BPDE (2) with DNA may take place preferentially at certain specific base sequences in DNA.