[A phase I study of subcutaneous envafolimab (KN035) monotherapy in Chinese patients with advanced solid tumors].

Objective: To evaluate the safety and antitumor activity of envafolimab monotherapy in Chinese patients with advanced solid tumors. Methods: This open-label, multicenter phase I trial included dose escalation and dose expansion phases. In the dose escalation phase, patients received subcutaneous 0.1, 0.3, 1.0, 2.5, 5.0 or 10.0 mg/kg envafolimab once weekly (QW) following a modified "3+ 3" design. The dose expansion phase was performed in the 2.5 mg/kg and 5.0 mg/kg (QW) dose cohorts. Results: At November 25, 2019, a total of 287 patients received envafolimab treatment. During the dose escalation phase, no dose-limiting toxicities (DLT) was observed. In all dose cohorts, drug-related treatment-emergent adverse events (TEAEs) for all grades occurred in 75.3% of patients, and grade 3 or 4 occurred in 20.6% of patients. The incidence of immune-related adverse reactions (irAE) was 24.0% for all grades, the most common irAEs (≥2%) included hypothyroidism, hyperthyroidism, immune-associated hepatitis and rash. The incidence of injection site reactions was low (3.8%), all of which were grades 1-2. Among the 216 efficacy evaluable patients, the objective response rate (ORR) and disease control rate (DCR) were 11.6% and 43.1%, respectively. Median duration of response was 49.1 weeks (95% CI: 24.0, 49.3). Pharmacokinetic (PK) exposure to envafolimab is proportional to dose and median time to maximum plasma concentration is 72-120 hours based on the PK results from the dose escalation phase of the study. Conclusion: Subcutaneous envafolimab has a favorable safety and promising preliminary anti-tumor activity in Chinese patients with advanced solid tumors.

[Atezolizumab therapy in Chinese patients with locally advanced or metastatic solid tumors: An open-label, phase â study].

OBJECTIVE: To evaluate pharmacokinetics (PK), efficacy, and safety of atezolizumab (anti-PD-L1) in high interest cancers in China, including esophageal cancer (EC), gastric cancer (GC), hepatocellular carcinoma (HCC), nasopharyngeal cancer (NPC), and non-small cell lung can-cer (NSCLC). METHODS: This phase I, open-label study was conducted at 6 Chinese sites from August 4, 2016 to April 15, 2019. The patients were ≥18 years old with a histologically documented incurable or metastatic solid tumor that was advanced or recurrent and had progressed since the last anti-tumor the-rapy. The PK phase characterized PK and safety of atezolizumab following multiple-dose administration when atezolizumab was administered as a single agent. The extension phase studied safety and efficacy of atezolizumab, as monotherapy (EC, GC, HCC, NPC) and with chemotherapy (NSCLC). RESULTS: This study enrolled 120 patients (PK phase: n=20; extension phase: n=20/cohort). Fourty-two patients (42.0%) were PD-L1 positive in atezolizumab monotherapy group (100 patients), of the 9 patients (9.0%) with microsatellite instability-high (MSI-H) tumors. Atezolizumab clearance was 0.219 L/d, and steady state was reached after 6 to 9 weeks (2-3 cycles) of repeated dosing. Objective response rates (ORRs) in EC, GC, HCC, NPC, and NSCLC were 10.0%, 15.0%, 10.0%, 5.0%, and 40.0%, respectively. In the patients with PD-L1 positive tumors, ORR was 11.9% with atezolizumab and 46.2% with atezolizumab plus gemcitabine and cisplatin. Two GC patients achieved durable response after pseudo-progression. The most common treatment-related adverse events in the atezolizumab monotherapy group were fatigue, anemia, fever, and decreased white blood cell count. The most common treatment-related adverse events in the combination group were anemia, decreased white blood cell count, and decreased appetite. No new safety signals were identified. CONCLUSION: Atezolizumab's PK, efficacy, and safety were similar in Chinese patients vs. global patients in previous studies.

Integrating tumor mutational burden and transcriptome expression into prediction of immune checkpoint inhibitor response and prognosis of patients with colon cancer.

Whether tumor mutational burden (TMB), which refers to the total number of somatic or acquired mutations per million bases in a particular region of the tumor genome, can serve as a predictive biomarker of immune checkpoint inhibitor (ICI) therapy for colon cancer remains unclear. Hereby, we retrospectively investigated the differentially expressed genes (DEGs) based on the level of TMB and tried to established a risk score model as a novel biomarker. The DNA mutation data were retrieved from the Masked Somatic Mutation in Genomic Data Commons data portal of the Cancer Genome Atlas, where the RNA sequencing data, clinical information, and survival outcomes of patients were downloaded. Patients with incomplete clinical information were excluded. The immune score and stromal score were calculated to investigate immune infiltration. The patients were grouped into TMB-high group and the TMB-low group based on the median value of TMB. An immune relevant gene set was obtained from the Immunology Database and Analysis Portal to identify immune-related DEGs. The Cox proportional hazard model and nomogram were applied to establish the risk model. In results: the TMB value was associated with age (p≤0.001), clinical stage (p≤0.001), N stage (p≤0.001), M stage (p=0.003), and immune score (p≤0.001). Twenty-nine immune-related DEGs were identified as enriched in immune response-related function or pathway and tumorigenesis signaling. Nine of 29 were determined to establish a riskScore model. The riskScore suggested a positive relationship with the TMB value (p=0.033), immune score (p≤0.001), and tumor immune dysfunction and exclusion (TIDE) (p=0.002) and presented an independent prognostic factor (p≤0.001, HR=1.04), which predicted the overall survival with good specificity. We concluded that the combination of TMB with transcriptome expression has a predictive and prognostic value for patients treated with ICIs.

[Death-related risk factors analysis of surgical treatment of myocardial infarction combined with ventricular septal rupture].

Objective: To in vestigate the death-related risk factors of surgical treatment of myocardial infarction (MI) combined with ventricular septal rupture (VSR). Methods: The clinical data of patients (68 cases) with ventricular septal rupture after myocardial infarction (PI-VSR) from January 2008 to December 2020 in Beijing Anzhen Hospital were retrospectively selected and analyzed. We followed up the surviving patients and divided them into the survival group and the death group according to the perioperative and follow-up results. The univariate analysis was performed on various indicators, and the Cox regression analysis was used to analyze the risk factors related to postoperative death. Results: A total of 68 patients (42 were male and 26 were female, with age 44-82 (64.3±8.2) years after surgical treatment of myocardial infarction combined with ventricular septal rupture were enrolled, 9 patients died during the perioperative period, 59 surviving patients were followed up for 0.1-10.5 years(mean, 4 years), and 7 deaths during follow-up. Based on this, 52 patients were selected as the survival group while 16 patients as the death group. The results of univariate analysis showed that age, VSR to operation time less than 7 days, killip grade ≥ grade 3, cardiogenic shock, preoperative use of IABP, emergent surgery were related to postoperative death. The factors with P<0.2 factors in univariate analysis were selected into the multivariate Cox regression analysis. Age ([OR=1.110(1.012-1.217), P=0.026], platelet count [OR=0.990(0.981-0.999), P=0.031], D dimer (OR=1.002[1.001-1.003], P=0.003), cardiogenic shock (OR=6.084[1.729-21.405], P=0.005) were independent risk factors for postoperative death. All patients were followed up, the survival rate of 2-year, 4-year, 6-year, 8-year, and 10-year was 77.5%, 77.5%, 71.0%, 71.0%, and 71.0%, respectively. Conclusions: Age, platelet count, D-dimer, and cardiogenic shock are risk factors for death after surgical treatment of myocardial infarction combined with ventricular septal rupture. Surgery is an effective method for the treatment of myocardial infarction combined with ventricular septal rupture. Long-term prognosis of the surviving patients during perioperative are relatively better.

[Clinicopathological features and survival analysis of gastric cancer patients with neuroendocrine differentiation after radical resection].

Objective: To compare the clinicopathological characteristics and the prognosis of gastric adenocarcinoma patients with and without neuroendocrine differentiation (NED) after radical gastrectomy plus D2 lymph node dissection. Methods: A retrospective cohort study was performed. The inclusion criteria were as follows: (1) patients who underwent radical resection of gastric cancer plus D2 lymph node dissection and were confirmed as gastric adenocarcinoma by postoperative pathology and received immunohistochemical examination of neuroendocrine markers Syn and/or CgA; (2) patients aged 20 to 75 years with normal organ function; (3) patients who did not receive neoadjuvant chemotherapy or radiotherapy before operation; (4) patients with postoperative pathological stage I to III according to the 8th edition of tumor staging system of American Joint Committee on Cancer (AJCC); and (5) patients who completed adjuvant chemotherapy according to the postoperative pathological stage. Those who had other malignant tumors in the past 5 years and who could not be followed up according to the required rules were excluded. According to the above criteria, the clinicopathological characteristics of gastric cancer patients who underwent radical resection plus D2 lymph node dissection in Zhongshan Hospital of Fudan University from January 2010 to June 2017 were collected and compared. All patients were followed up till June 2020. The disease-free survival (DFS) and overall survival (OS) between the patients with and without NED were compared, and the effect of NED on the prognosis was corrected by Cox proportional hazards model. The propensity score matching method was used for sensitivity analysis. Results: A total of 539 patients were enrolled in this study, including 35 with NED and 504 without NED. Compared with the patients without NED, the patients with NED were older [(65.0±7.5) years vs. (54.5±11.3) years, t=-7.681, P<0.001], had higher proportion of undergoing proximal gastrectomy [22.9% (8/35) vs. 7.6% (36/504), χ(2)=10.335, P=0.006], higher proportion of intestinal-type based on Lauren classification [77.1% (27/35) vs. 42.5% (214/504), χ(2)=14.553, P<0.001], and higher proportion of pathologic stage III [65.7% (23/35) vs. 27.6% (139/504), χ(2)=25.653, P<0.001]. The 3-year DFS of patients with NED and those without NED was 48.9% (95% CI: 33.8%-70.8%) and 37.4% (95% CI: 32.9%-42.5%) respectively, and no significant difference was found (P=0.44). The 3-year OS was 56.1% (95% CI: 39.9%-79.1%) and 64.3% (95% CI: 59.3%-69.7%) respectively, and no significant difference was found as well (P=0.32). Univariate and multivariate analyses showed that NED was not an independent risk factor for DFS and OS (all P>0.05). Sensitivity analysis showed that there was no significant difference in DFS and OS between the two groups after propensity score matching. Conclusion: Compared with patients without NED, patients with NED were older at onset, had a higher proportion of proximal gastrectomy, intestinal-type, and later diagnostic stage, but the survival prognosis had no significant difference with that of patients without NED.

[Clinical analysis of intravenous-cardiac leiomyomatosis].

Objective: To summarize the clinical characteristics, treatment and prognosis of patients with right intravenous-cardiac leiomyomatosis, and provide references for clinical diagnosis and management. Methods: The clinical data of 22 patients who were admitted to Department of Cardiac Surgery in Beijing Anzhen Hospital from November 2009 to July 2019 were retrospectively reviewed. The long-term prognosis of the patients was also evaluated. Results: All patients were women, with an age of (48.1±6.3) years. The clinical manifestations of patients lacked specificity. Among them, 14 patients had a history of uterine leiomyoma, 12 had hysterectomy, and 5 had abortions. Twenty patients underwent tumor resection. One-stage operation was performed in 15 cases, while staging surgery was performed in 5 cases. Ten cases underwent tumor resection under cardiopulmonary bypass. One case underwent a tricuspid valve annuloplasty at the same time. There was no death early in postoperative period. Early complications included deep venous thrombosis (2 cases), type Ⅱ atrioventricular block (1 case), pleural effusion (1 case) and incision infection (1 case). In the long-term follow-up (3 years), one case died of tumor recurrence-associated circulatory failure. Among the rest of the patients, the quality of life was satisfying, and cardiac function was between grade Ⅰ and Ⅱ, with no recurrence or metastasis. Conclusions: Patients with intravenous-cardiac leiomyomatosis are lack of specific manifestations. Early diagnosis is crucial for the treatment of this disease. Tumor resection is an effective treatment, which can improve the quality of life and long-term survival of patients.

[Short-term clinical safety and efficacy of No-touch great saphenous vein harvesting technique for off-pump coronary artery bypass grafting].

Objective: To evaluated early clinical outcomes of saphenous vein grafts harvested with a No-touch technique in off-pump coronary artery bypass graft (OPCABG) surgery. Methods: A total of 124 patients with three-vessel disease undergoing OPCABG by No-touch technique between June and November 2017 in Beijing An Zhen Hospital were respectively reviewed. Results: The average age of patients was (60.7±10.3) years, and 80 cases (64.5%) were male, with the average body mass index (BMI)of (25.4±2.5) kg/m(2,) the mean preoperative left ventricular ejection fraction (LVEF) of (58.0±7.0%). The operative time was (4.0±0.4) hours, and 16 cases (12.9%) were harvested for whole vein grafts. The number of vein grafts and venous anastomoses was 144 and 284, respectively. There were 16 cases of single bridge NTSVG-LAD, 4 cases of single bridge NTSVG-D, 99 cases of sequential bridge NTSVG-OM-PDA, 5 cases of sequential bridge NTSVG-OM-PLV, 4 cases of sequential bridge NTSVG-OM-RCA, 16 cases of sequential bridge NTSVG-D-OM-PDA. The mean flow volume of No-touch vein grafts was (51.9±2.4) ml/min. There was no death case in hospital. Postoperative re-exploration for hemorrhage of anastomosis happened in 1 case (0.8%), which was caused by pericardial tamponade due to insufficiency of hemostasis in internal mammary bed. There were 1 case of bad wound healing of lower extremity incision (0.8%). A total of 124 cases were followed up after operation, and the follow-up rate was 100%. There was one all-cause death (0.8%) 27 days after the operation. Conclusion: The short-term clinical observation of the application of No-touch great saphenous vein harvesting technique for OPCABG is safe and effective.

[Safety and efficacy of off-pump coronary artery bypass grafting in octogenarians].

Objective: To discuss the clinical safety and efficacy about off-pump coronary artery bypass grafting (OPCABG) in octogenarians. Methods: From June 2005 to July 2014, 252 patients (male 208, female 44, with a mean age of 81.7 years old) underwent OPCABG in Beijing Anzhen Hospital who were aged 80 years or older were enrolled. Results: Eight (3.2%) patients were diagnosed as single vessel coronary artery disease (CAD), 29 cases (11.5%) were diagnosed as bifurcation vessel CAD, and 215 cases (85.3%) were multivessel CAD. One hundred and one cases (40.1%) were diagnosed as left main artery disease, among which 51 cases (20.2%) had old myocardial infarction. Two hundred and forty-eight patients belonged to Canadian Cardiovascular Society (CCS) classⅠ-Ⅲ and 4 cases to CCS class Ⅳ. One hundred and forty-five cases belonged to New York Heart Association (NYHA) classⅠ-Ⅱ and 107 cases to NYHA class Ⅲ-Ⅳ. Mean graft number was 3. Two hundred and six patients (81.7%) received total vein graft operation. Intra-aortic balloon pump (IABP) was used in 43 patients (17.1%). In-hospital death occurred in 15 cases (6.0%). Major in-hospital complications included reoperation (16 cases), re-intubation (16 cases), dialysis (11 cases), sternum infection (2 cases), atrial fibrillation (63 cases). The follow-up time was from 1 to 11 years (with a mean time of 6 years). All-cause mortality was 18.1% (43 cases). The major out-of-hospital complications included recurrent myocardial infarction (3 cases), stroke (3 cases), re-admission (27 cases) and recurrent angina pectoris (20 cases). Conclusion: OPCABG is safe and effective for myocardial revascularization in patients aged 80 years and over.

Study on bending behaviour of nickel-titanium rotary endodontic instruments by analytical and numerical analyses.

AIM: To develop analytical models and analyse the stress distribution and flexibility of nickel-titanium (NiTi) instruments subject to bending forces. METHODOLOGY: The analytical method was used to analyse the behaviours of NiTi instruments under bending forces. Two NiTi instruments (RaCe and Mani NRT) with different cross-sections and geometries were considered. Analytical results were derived using Euler-Bernoulli nonlinear differential equations that took into account the screw pitch variation of these NiTi instruments. In addition, the nonlinear deformation analysis based on the analytical model and the finite element nonlinear analysis was carried out. Numerical results are obtained by carrying out a finite element method. RESULTS: According to analytical results, the maximum curvature of the instrument occurs near the instrument tip. Results of the finite element analysis revealed that the position of maximum von Mises stress was near the instrument tip. Therefore, the proposed analytical model can be used to predict the position of maximum curvature in the instrument where fracture may occur. Finally, results of analytical and numerical models were compatible. CONCLUSION: The proposed analytical model was validated by numerical results in analysing bending deformation of NiTi instruments. The analytical model is useful in the design and analysis of instruments. The proposed theoretical model is effective in studying the flexibility of NiTi instruments. Compared with the finite element method, the analytical model can deal conveniently and effectively with the subject of bending behaviour of rotary NiTi endodontic instruments.

Prediction of Cadmium uptake by brown rice and derivation of soil-plant transfer models to improve soil protection guidelines.

Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To ensure the production of rice that meets food quality standards, predictive models or suitable soil tests are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range from less than 0.1 mg kg(-1) to 30 mg kg(-1). Measured Cd levels in brown rice were predicted very well (R(2) > 0.8) based on Cd and Zinc in a 0.01 M CaCl(2) extract or a soil-plant transfer model using the reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality standards.

An updated meta-analysis of adjuvant chemotherapy after curative resection for gastric cancer.

OBJECTIVES: To investigate whether and how much gastric cancer patients after curative resection could benefit from chemotherapy. PATIENTS AND METHODS: Meta-analysis was conducted with all the qualified clinical randomized trials which compared adjuvant chemotherapy with surgery alone. The database includes MEDLINE, EMBase and CBM disc, and the censor data were up to November 2007. Primary outcomes were relative risk (RR) on death and disease-free survival (DFS); secondary outcomes include RR of adverse reactions of the two arms. Sub-group analysis and sensitivity analysis were also performed. All the calculations and statistical tests were done with the RevMan 4.2.8 software. RESULTS: Finally, 23 trials which included 4919 patients (2441 in the adjuvant chemotherapy arm, 2478 in the observation arm) achieved all the criteria. Among them, 19 studies reported the survival rate at the end of follow-up, 60.6% alive among 2286 patients in the adjuvant chemotherapy arm, 53.4% alive among 2313 patients in the observation arm, with the RR on death of 0.85 (95%CI: 0.80-0.90). Eight studies reported the DFS, and the observation arm had a shorter DFS (RR: 0.88, 95%CI: 0.77-0.99). Grade 3/4 of myelosuppression and GI toxicity occurred more frequently in the treatment arm. Nine studies reported the recurrence rate and suggested that the treatment arm had a lower recurrence rate (RR: 0.78, 95%CI: 0.71 approximately 0.86). CONCLUSIONS: Statistically, adjuvant chemotherapy could improve the survival rate and disease-free survival rate in gastric cancer after curative resection and reduce the relapse rate. However, the clinical benefits of adjuvant chemotherapy still need to be improved. Additionally, post-operative chemotherapy could be tolerated.

Altered mucin gene expression in stone-containing intrahepatic bile ducts and cholangiocarcinomas.

Neoplastic transformation of epithelial cells is commonly associated with alterations in the synthesis and structures of mucin. Mucin protein epitopes and mRNA levels were frequently altered in adenocarcinomas compared to corresponding normal tissues. Clinically, hepatolithiasis has been regarded as a risk factor for cholangiocarcinoma. The aims of this study were to determine the possible alteration of mucin gene expression in stone-containing intrahepatic bile ducts and cholangiocarcinomas and to try to predict whether or not hepatolithiasis has a predisposition to development of cholangiocarcinoma. In situ hybridization with DIG-tailed oligonucleotides was performed on sections of paraffin-embedded tissues of stone-containing intrahepatic bile ducts, cholangiocarcinomas, and normal controls to identify the expression of MUC2, MUC3, MUC4, MUC5B, and MUC5AC in nonneoplastic and neoplastic biliary epithelium. The findings showed that (1) while multiple diverse mucin genes were expressed in the biliary epithelium, MUC3 and MUC5B mRNA were the main mucin genes expressed in the biliary epithelium of stone-containing intrahepatic bile ducts and normal controls; (2) absent or decreased expression of MUC2, MUC3, and MUC5B of mRNA was found in cholangiocarcinomas in contrast to nonneoplastic biliary epithelium; and (3) increased expression of MUC4 and MU5AC of mRNA was found in cholangiocarcinomas and the biliary epithelium, especially for dysplastic cells of stone-containing intrahepatic bile ducts compared with normal controls. In this study, using in situ hybridization we demonstrated that neoplastic transformation of the biliary epithelium is accompained by alterations in mucin gene expression, the altered mucin gene expression in dysplastic cells of stone-containing intrahepatic bile ducts may reflect a higher potential for malignant transformation in these cells, and it could be a precursor of cholangiocarcinoma in the presence of hepatolithiasis.

Roles of TNF-related apoptosis-inducing ligand in experimental autoimmune encephalomyelitis.

TRAIL, the TNF-related apoptosis-inducing ligand, induces apoptosis of tumor cells, but not normal cells; the roles of TRAIL in nontransformed tissues are unknown. Using a soluble TRAIL receptor, we examined the consequences of TRAIL blockade in an animal model of multiple sclerosis. We found that chronic TRAIL blockade in mice exacerbated experimental autoimmune encephalomyelitis induced by myelin oligodendrocyte glycoprotein. The exacerbation was evidenced primarily by increases in disease score and degree of inflammation in the CNS. Interestingly, the degree of apoptosis of inflammatory cells in the CNS was not affected by TRAIL blockade, suggesting that TRAIL may not regulate apoptosis of inflammatory cells in experimental autoimmune encephalomyelitis. By contrast, myelin oligodendrocyte glycoprotein-specific Th1 and Th2 cell responses were significantly enhanced in animals treated with the soluble TRAIL receptor. Based on these observations, we conclude that unlike TNF, which promotes autoimmune inflammation, TRAIL inhibits autoimmune encephalomyelitis and prevents activation of autoreactive T cells.

Mucin gene expression in gallbladder epithelium with black pigment stone ascertained by in situ hybridization.

Black pigment stones are usually found in patients with liver cirrhosis or hemolytic disease. Mucoglycoproteins are present in a significant amount in black pigment stones and contribute to the matrix of gallstones. Epithelium of stone-containing gallbladders contains much more mucin than those without stones. In this study, we try to determine by in situ hybridization the mucin gene expression in black stone-containing gallbladders and try to find the diversity of mucin gene expression in gallbladders containing black pigment stones and those without stones. In situ hybridization with DIG-tailed oligonucleotides was performed on sections of paraffin-embedded tissues of gallbladders with black pigment stones (n = 10) and those without stones (n = 6) to identify the expression of MUC1, MUC2, MUC3, MUC4, MUC5B and MUC6 in gallbladder epithelium. The findings showed that (1) mRNA expression of MUC1, MUC3, MUC5B and MUC6 were found in all gallbladders with black pigment stones, while they were expressed in 33.3%, 83.3%, 83.3% and 66.7% respectively in those without stones. They were expressed more strongly and extensively in gallbladders with stones when compared to those without stones. (2) MUC2 and MUC4 labeling were absent in gallbladders without stones, while they were present in 20% and 60% of gallbladders with black pigment stones, respectively. We conclude that MUC3, MUC5B and MUC6 were the main mucin gene expression in either gallbladder with or without stones. Altered mucin gene expression occurred in gallbladders with black pigment stones, such as the presence of MUC2 and MUC4 and increased expression of MUC1, MUC3, MUC5B and MUC6 in black stone-containing gallbladders. The higher incidence and stronger labeling intensity of mucin gene expression of MUC2, MUC3, MUC5B and MUC6 in black stone-containing gallbladder may reflect abundant mucin content in these gallbladders. Increased expression of MUC2 and MUC4 in black stone-containing gallbladder epithelium indicated that intestinal metaplasia and altered mucin genes could occur in diseased gallbladders.

Differential roles of Fas ligand in spontaneous and actively induced autoimmune encephalomyelitis.

To determine the roles of Fas/Fas ligand (FasL) in autoimmunity, we studied spontaneous and actively induced autoimmune encephalomyelitis in 541 myelin basic protein-specific T cell receptor transgenic mice. We found that spontaneous autoimmune encephalomyelitis, which was initiated by unidentified microbial factors, was dramatically exacerbated in mice carrying Fas or FasL gene mutation. The exacerbation of autoimmune encephalomyelitis was reflected primarily by an increase in disease incidence and a decrease in spontaneous disease recovery. By contrast, actively induced encephalomyelitis, which was initiated by pertussis toxin, was significantly inhibited by Fas or FasL gene mutation. These results suggest that environmental factors that trigger autoimmune disease may determine not only whether disease will occur but also whether an immune molecule such as FasL will promote or inhibit the autoimmune process.

IL-6-deficient mice are resistant to experimental autoimmune encephalomyelitis: roles of IL-6 in the activation and differentiation of autoreactive T cells.

Although autoreactive T cells recognizing self myelin Ags are present in most individuals, autoimmune disease of the central nervous system is a relatively rare medical condition. Development of autoimmune disease may require not only the presence of autoreactive T cells but also that autoreactive T cells become activated. Activation of T cells may require a minimum of two signals: an Ag-specific signal delivered by MHC-peptide complex and a second signal delivered by costimulatory molecules or cytokines. Although in vitro studies have suggested that cytokines, especially proinflammatory cytokines such as IL-1, IL-6, and TNF are involved in T cell activation, their precise roles in vivo are not clear. To determine the roles of proinflammatory cytokines in T cell activation in vivo and in the development of autoimmune disease, we have studied experimental autoimmune encephalomyelitis (EAE) in mice deficient in IL-6. We found that IL-6-deficient mice were completely resistant to EAE induced by myelin oligodendrocyte glycoprotein (MOG), whereas IL-6-competent control mice developed EAE characterized by focal inflammation and demyelination in the central nervous system and deficiency in neurologic functions. Furthermore, we established that the resistance to EAE in IL-6-deficient mice was associated with a deficiency of MOG-specific T cells to differentiate into either Th1 or Th2 type effector cells in vivo. These results strongly suggest that IL-6 plays a crucial role in the activation and differentiation of autoreactive T cells in vivo and that blocking IL-6 function can be an effective means to prevent EAE.

Fos-like immunoreactivity in central auditory neurons of the mouse.

Fos-like immunoreactivity was used to study sound-induced activation of neurons in the auditory brainstem. Immunoreactivity was assayed with a polyclonal antibody to Fos. In response to 6-kHz tone bursts, the pattern of staining was a band of immunoreactive neurons positioned at the tonotopically appropriate position within the cochlear nucleus and the inferior colliculus. The band was narrow at low sound pressure levels but wider along the tonotopic axis at higher sound levels. In response to noise bursts, the pattern was broader and often extended throughout the auditory nuclei. Often within this broad pattern were "sub-bands" of immunostained neurons, interspersed with bands of unstained neurons. With increasing sound pressure levels above 35-55 dB, the number of Fos-like immunoreactive neurons increased for the cochlear nucleus, superior olivary complex, and inferior colliculus. In the cochlear nucleus and inferior colliculus, the stained cells were small, and hence their activity would be difficult to sample in electrophysiological studies. In the medial nucleus of the trapezoid body, the stained neurons had larger somata and other characteristics of principal cells. Anesthesia with Nembutal or Avertin, but not with ketamine or urethane, decreased the number of Fos-like immunoreactive neurons in the cochlear nucleus. The different anesthetics produced more variable results in the inferior colliculus. In anesthetized, monaurally stimulated animals, the presence of staining in the contralateral cochlear nucleus indicates that some Fos-like immunoreactivity may be mediated by descending or commissural systems. These observations indicate that Fos assays are useful for studying the pattern of neuronal activation in the auditory system and may also be useful in studying the descending auditory pathways.