Prognostic impact of concomitant pH-regulating drugs in patients with non-small cell lung cancer receiving epidermal growth factor receptor tyrosine kinase inhibitors: the Tokushukai REAl-world Data project 01-S1

PURPOSE

This study aimed to examine the prognostic impact of concomitant pH-regulating drug use in patients with epidermal growth factor receptor (EGFR)-mutation-positive non-small-cell lung cancer (NSCLC) receiving EGFR-tyrosine kinase inhibitors (TKIs).

METHODS

We conducted a nationwide retrospective cohort study and reviewed clinical data of consecutive patients with NSCLC treated with the first-line EGFR-TKIs in 46 hospitals between April 2010 and March 2020. Cox regression analyses were conducted to examine the differences in overall survival (OS) between patients treated with and without concomitant pH-regulating drugs, including potassium-competitive acid blockers (P-CABs), proton pump inhibitors (PPIs), and H2-receptor antagonists (H2RAs).

RESULTS

A total of 758 patients were included in the final dataset, of which 307 (40%) were administered concomitant pH-regulating drugs while receiving frontline EGFR-TKIs. After adjusting for basic patient characteristics, patients administered gefitinib, erlotinib, afatinib, and osimertinib with concomitant pH-regulating drugs had lower OS than those without concomitant pH-regulating drugs, with hazard ratios of 1.74 (with a 95% confidence interval of 1.34-2.27), 1.33 (0.80-2.22), 1.73 (0.89-3.36), and 5.04 (1.38-18.44), respectively. The 2-year OS rates of patients receiving gefitinib with or without concomitant pH-regulating drugs were 65.4 and 77.5%, those for erlotinib were 55.8 and 66.6%, and those for afatinib were 63.2 and 76.9%, respectively. The 1-year OS rates of patients receiving osimertinib with or without concomitant pH-regulating drugs were 88.1% and 96.9%, respectively.

CONCLUSION

In addition to the first-generation EGFR-TKIs, the second- and third-generation EGFR-TKIs also resulted in OS deterioration in patients with EGFR mutation-positive NSCLC when used concurrently with pH-regulating drugs.

Stepwise prolongation of overall survival from first to third generation EGFR-TKIs for EGFR mutation-positive non-small-cell lung cancer: the Tokushukai REAl-world Data project (TREAD 01)

OBJECTIVE

The introduction of new-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has afforded promising overall survival outcomes in clinical trials for non-small-cell lung cancer. We aim to investigate the current adoption rate of these agents and the real-world impact on overall survival among institutions.

METHODS

In a nationwide retrospective cohort study of 46 Tokushukai Medical Group hospitals in Japan, we analyzed clinical data of consecutive patients with non-small-cell lung cancer receiving EGFR-TKIs between April 2010 and March 2020. Univariate and multivariate Cox regression analyses examined the associations between overall survival and patient/tumor-related factors and first-line EGFR-TKIs.

RESULTS

A total of 758 patients (58.5% females; median age, 73 years) were included. Of 40 patients diagnosed in 2010, 72.5% received gefitinib, whereas 81.3% of 107 patients diagnosed in 2019 received osimertinib as the first-line EGFR-TKI. With a median follow-up of 15.8 months, the median overall survival was 28.4 months (95% confidence interval, 15.3-31.0). In a multivariate Cox regression analysis, age, body mass index, disease status, EGFR mutational status and first-line epidermal growth factor receptor tyrosine kinase inhibitor were identified as significant prognostic factors after adjusting for background factors including study period, hospital volume and hospital type. The estimated 2-year overall survival rates for gefitinib, erlotinib, afatinib and osimertinib were 70.1% (95% confidence interval 59.7-82.4), 67.8% (95% confidence interval 55.3-83.2), 75.5% (95% confidence interval 64.7-88.0) and 90.8% (95% confidence interval 84.8-97.3), respectively. The median time to treatment failure of gefitinib, erlotinib, afatinib and osimertinib were 12.8, 8.8, 12.0 and 16.9 months or more, respectively.

CONCLUSIONS

Our real-world data revealed that the swift and widespread utilization of newer-generation EGFR-TKIs in patients with EGFR mutation-positive non-small-cell lung cancer, and that these newer-generation EGFR-TKIs can prolong overall survival regardless of hospital volume or type. Therefore, osimertinib could be a reasonable first choice treatment for these patients across various clinical practice settings.

Inflammation‑based prognostic markers of metastatic pancreatic cancer using real‑world data in Japan: The Tokushukai REAl‑world Data (TREAD) project

Inflammation-based prognostic markers based on a combination of blood-based parameters, including the modified Glasgow prognostic score (mGPS), have been associated with clinical outcomes in patients with various types of cancer. The present study aimed to evaluate and compare the accuracy of these previously reported markers in patients with metastatic pancreatic cancer receiving first-line chemotherapy. A total of 846 patients were identified between April 2010 and March 2020 as part of a nationwide real-world study from 46 Tokushukai medical group hospitals in Japan. Blood laboratory data collected within 14 days of starting first-line chemotherapy assessed 17 inflammation-based prognostic markers. Information from patients with no missing data was used to compare the accuracy and performance of the inflammation-based prognostic markers. A total of 487 patients were eligible for this supplemental analysis. The 17 inflammation-based markers demonstrated significant prognostic value. Among them, the concordance rate with overall survival (OS) was highest for mGPS. The median OS time of patients with mGPS 0, 1 and 2 was 8.2, 6.0 and 2.9 months, respectively. Compared with mGPS 0, mGPS 1 and 2 showed hazard ratios of 1.39 (95% confidence interval, 1.07-1.81) and 2.63 (2.00-3.45), respectively. The present real-world data analysis showed that various previously reported inflammation-based markers had significant prognostic value in patients with metastatic pancreatic cancer. Among these markers, the mGPS demonstrated the highest level of accuracy. This trial has been registered in the University Hospital Medical Information Network Clinical Trials Registry as UMIN000050590 on April 1, 2023.

Real-world treatment outcomes of metastatic biliary tract cancer patients in Japan: the Tokushukai REAl-world data project 04 (TREAD 04)

OBJECTIVES

To investigate temporal trends in treatment patterns and prognostic factors for overall survival in patients with metastatic biliary tract cancer.

METHODS

From the Tokushukai REAl-world Data project, we identified 945 patients with metastatic biliary tract cancer treated with gemcitabine, tegafur/gimeracil/oteracil, gemcitabine plus cisplatin, gemcitabine plus tegafur/gimeracil/oteracil or gemcitabine plus cisplatin and tegafur/gimeracil/oteracil between April 2010 and March 2022. Stratified/conventional Cox regression analyses were conducted to examine the association between overall survival and patient- and tumour-related factors, study period, hospital volume, hospital type and first-line chemotherapy regimen. Using inverse probability of treatment weighting with propensity scores, overall survival was also compared between monotherapy and combination therapy groups.

RESULTS

We enrolled 366 patients (199 men; median age, 72 years). Over a median follow-up of 5.2 months, the median overall survival was 7.0 months (95% confidence interval 6.2-9.0), and the median time to treatment failure was 3.5 months (95% confidence interval 3.1-4.5). Median overall survival and time to treatment failure for gemcitabine/tegafur-gimeracil-oteracil/gemcitabine plus cisplatin/gemcitabine plus tegafur-gimeracil-oteracil/gemcitabine plus cisplatin and tegafur-gimeracil-oteracil regimen were 6.2/6.6/7.9/16.2/15.1 and 2.8/3.4/4.1/15.3/7.4 months, respectively. Primary disease site, previous surgery, previous endoscopic procedures and hospital type were identified as significant prognostic factors. Inverse probability of treatment weighting analysis demonstrated that combination therapy had a significantly better prognosis than monotherapy (hazard ratio 0.61, 95% confidence interval 0.43-0.88, P = 0.006).

CONCLUSIONS

Our real-world data analysis showed that standard care for metastatic biliary tract cancer is widely used in hospitals throughout Japan and verified the survival benefits of combination therapy over monotherapy observed in prior clinical trials.

CLINICAL TRIAL NUMBER

UMIN000050590 (http://www.umin.ac.jp/ctr/index.htm).

Malignant involvement of the iliopsoas muscle associated with non-small cell lung cancer: Two case reports

Under the current progression of molecular targeting or immune therapy, early detection and radiation therapy of iliopsoas metastasis will not only improve performance status but also enable the continuation of effective systemic cancer treatment.

Real‑world treatment outcomes among patients with metastatic pancreatic cancer in Japan: The Tokushukai real‑world data project

The present study aimed to investigate temporal trends in treatment patterns and prognostic factors for overall survival (OS) among patients with metastatic pancreatic cancer. From the Tokushukai REAl-world Data project, 1,093 patients with metastatic pancreatic cancer treated with gemcitabine, tegafur/gimeracil/oteracil (S-1), gemcitabine plus S-1, gemcitabine plus nab-paclitaxel, or fluorouracil, folic acid, oxaliplatin and irinotecan (FOLFIRINOX) between April 2010 and March 2020 were identified. Stratified/conventional Cox regression analyses were conducted to examine associations between patient- and tumor-related factors, study period, hospital volume, hospital type and first-line chemotherapy regimens. Overall, 846 patients were selected (503 male patients; median age, 70 years) after excluding ineligible patients. Over a median follow-up of 5.4 months, the median OS was 6.8 months (95% confidence interval, 6.3-7.4). The median OS for gemcitabine, S-1, gemcitabine plus S-1, gemcitabine plus nab-paclitaxel and FOLFIRINOX regimens was 5.9, 5.3, 7.7, 9.0 and 9.5 months, respectively. The median OS for 2010-2013, 2014-2017 and 2017-2020 was 6.2, 7.1 and 7.8 months, respectively. Performance status, body mass index and first-line chemotherapy regimens were identified to be significant prognostic factors. In summary, the real-world data indicated that standard care, including chemotherapy, for metastatic pancreatic cancer was widely used in hospitals throughout Japan and verified the survival benefits of gemcitabine plus nab-paclitaxel and FOLFIRINOX observed in prior clinical trials. This trial has been registered in the University Hospital Medical Information Network Clinical Trials Registry as UMIN000050590 on April 1, 2023.

Efficacy and Safety of Synbiotics in Patients Undergoing Autologous Hematopoietic Stem Cell Transplantation: A Randomized, Double-blinded, Placebo-controlled Pilot Study

Objective High-dose chemotherapy with autologous hematopoietic stem cell transplantation (auto-HSCT) is an effective treatment option for relapsed and refractory aggressive malignant lymphoma. However, patients frequently experience treatment-induced gastrointestinal symptoms. Synbiotics, including live microorganisms and nondigestible food ingredients, reportedly ameliorate chemotherapy-induced mucosal damage. In this study, we assessed the efficacy and safety of synbiotics in patients undergoing auto-HSCT. Methods This randomized, double-blinded study included patients with malignant lymphoma eligible for auto-HSCT. The patients were randomly assigned to either a synbiotic group receiving Bifidobacterium longum (BB536) and guar gum or a placebo group receiving a placebo containing dextrin. The supplements were administered twice daily from the start of conditioning chemotherapy up to 28 days after auto-HSCT. The primary endpoint was the duration of total parenteral nutrition (TPN). Results In total, 12 patients were included and randomized. The median duration of TPN was 15 (range, 12-33) days in the synbiotic group and 17.5 (range, 0-32) days in the placebo group. The median duration of grade ≥3 diarrhea was shorter in the synbiotic group than in then placebo group (2.5 vs. 6.5 days), as was the duration of hospital stay (31.5 vs. 43 days). The oral intake and quality of life regarding diarrhea and anorexia improved in the synbiotic group after engraftment. Synbiotic infections, including bacteremia, were not observed. Conclusion Synbiotics may reduce gastrointestinal toxicity, thereby reducing nutritional problems and improving the quality of life of patients undergoing auto-HSCT, without severe adverse events.

First-Line Chemoimmunotherapy versus Sequential Platinum-Based Chemotherapy Followed by Immunotherapy in Patients with Non-Small Cell Lung Cancer with ≤49% Programmed Death-Ligand 1 Expression: A Real-World Multicenter Retrospective Study

BACKGROUND

The long overall survival (OS) observed among patients with non-small cell lung cancer (NSCLC) with high programmed death-ligand 1 (PD-L1) expression in chemoimmunotherapy (CIT) groups in previous phase III trials suggests the limited efficacy of CIT among the subgroup with ≤49% PD-L1 expression on tumor cells. Hence, sequential treatment with first-line platinum-based chemotherapy followed by second-line immune checkpoint inhibitor treatment (SEQ) is an option. This study examined whether first-line CIT would provide better outcomes than SEQ in patients with advanced NSCLC with ≤49% PD-L1 expression.

METHODS

This retrospective study evaluated patients with untreated NSCLC who received first-line CIT or SEQ at nine hospitals in Japan. OS, progression-free survival (PFS), PFS-2 (the time from first-line treatment to progression to second-line treatment or death), and other related outcomes were evaluated between the CIT and SEQ groups.

RESULTS

Among the 305 enrolled patients, 234 eligible patients were analyzed: 165 in the CIT group and 69 in the SEQ group. The COX proportional hazards model suggested a significant interaction between PD-L1 expression and OS (p = 0.006). OS in the CIT group was significantly longer than that in the SEQ group in the 1-49% PD-L1 expression subgroup but not in the <1% PD-L1 expression subgroup. Among the subgroup with 1-49% PD-L1 expression, the CIT group exhibited longer median PFS than the SEQ group (CIT: 9.3 months (95% CI: 6.7-14.8) vs. SEQ:5.5 months (95% CI: 4.5-6.1); p < 0.001), while the median PFS in the CIT group was not statistically longer than the median PFS-2 in the SEQ group (p = 0.586). There was no significant difference between the median PFS in the CIT and SEQ groups among the <1% PD-L1 expression subgroup (p = 0.883); the median PFS-2 in the SEQ group was significantly longer than the median PFS in the CIT group (10.5 months (95% CI: 5.9-15.3) vs. 6.4 months (95% CI: 4.9-7.5); p = 0.024).

CONCLUSIONS

CIT is recommended for patients with NSCLC with 1-49% PD-L1 expression because it significantly improved OS and PFS compared to SEQ. CIT had limited benefits in patients with <1% PD-L1 expression, and the median PFS-2 in the SEQ group was significantly longer than the median PFS in the CIT group. These findings will help physicians select the most suitable treatment option for patients with NSCLC, considering PD-L1 expressions.

Predictive Value of Modified Glasgow Prognostic Score and Persistent Inflammation among Patients with Non-Small Cell Lung Cancer Treated with Durvalumab Consolidation after Chemoradiotherapy: A Multicenter Retrospective Study

BACKGROUND

Durvalumab consolidation after chemoradiotherapy (CRT) is a standard treatment for locally advanced non-small cell lung cancer (NSCLC). However, studies on immunological and nutritional markers to predict progression-free survival (PFS) and overall survival (OS) are inadequate. Systemic inflammation causes cancer cachexia and negatively affects immunotherapy efficacy, which also reflects survival outcomes.

PATIENTS AND METHODS

We retrospectively investigated 126 patients from seven institutes in Japan.

RESULTS

The modified Glasgow Prognostic Score (mGPS) values, before and after CRT, were the essential predictors among the evaluated indices. A systemic inflammation-based prognostic risk classification was created by combining mGPS values before CRT, and C-reactive protein (CRP) levels after CRT, to distinguish tumor-derived inflammation from CRT-induced inflammation. Patients were classified into high-risk (n = 31) and low-risk (n = 95) groups, and the high-risk group had a significantly shorter median PFS of 7.2 months and an OS of 19.6 months compared with the low-risk group. The hazard ratios for PFS and OS were 2.47 (95% confidence interval [CI]: 1.46-4.19, p < 0.001) and 3.62 (95% CI: 1.79-7.33, p < 0.001), respectively. This association was also observed in the subgroup with programmed cell death ligand 1 expression of ≥50%, but not in the <50% subgroup. Furthermore, durvalumab discontinuation was observed more frequently in the high-risk group than in the low-risk group.

CONCLUSION

Combining pre-CRT mGPS values with post-CRT CRP levels in patients with locally advanced NSCLC helps to predict the PFS and OS of durvalumab consolidation after CRT.

Age-Stratified Analysis of First-Line Chemoimmunotherapy for Extensive-Stage Small Cell Lung Cancer: Real-World Evidence from a Multicenter Retrospective Study

Chemoimmunotherapy improved overall survival (OS) and progression-free survival (PFS) in patients with extensive-stage small cell lung cancer (ES-SCLC) in two phase III trials. They set the age-stratified subgroup analyses at 65 years; however, over half of the patients with lung cancer were newly diagnosed at ≥75 years in Japan. Therefore, treatment efficacy and safety in elderly patients ≥ 75 years with ES-SCLC should be evaluated through real-world Japanese evidence. Consecutive Japanese patients with untreated ES-SCLC or limited-stage SCLC unfit for chemoradiotherapy between 5 August 2019 and 28 February 2022 were evaluated. Patients treated with chemoimmunotherapy were divided into the non-elderly (<75 years) and elderly (≥75 years) groups, and efficacy, including PFS, OS, and post-progression survival (PPS) were evaluated. In total, 225 patients were treated with first-line therapy, and 155 received chemoimmunotherapy (98 non-elderly and 57 elderly patients). The median PFS and OS in non-elderly and elderly were 5.1 and 14.1 months and 5.5 and 12.0 months, respectively, without significant differences. Multivariate analyses revealed that age and dose reduction at the initiation of the first chemoimmunotherapy cycle were not correlated with PFS or OS. In addition, patients with an Eastern Cooperative Oncology Group performance status (ECOG-PS) = 0 who underwent second-line therapy had significantly longer PPS than those with ECOG-PS = 1 at second-line therapy initiation (p < 0.001). First-line chemoimmunotherapy had similar efficacy in elderly and non-elderly patients. Individual ECOG-PS maintenance during first-line chemoimmunotherapy is crucial for improving the PPS of patients proceeding to second-line therapy.

Real-World Outcomes of Systemic Therapy in Japanese Patients with Cancer (Tokushukai REAl-World Data Project: TREAD): Study Protocol for a Nationwide Cohort Study

Cohort studies using large-scale databases have become increasingly important in recent years. The Tokushukai Medical Group is a leading medical group in Japan that includes 71 general hospitals nationwide from Hokkaido to Okinawa, with a total of 18,000 beds, and a unified electronic medical record system. This retrospective cohort study aims to evaluate the real-world outcomes of systemic therapy for Japanese patients with cancer using this merit of scale. All adult patients with cancer who received systemic therapy using a centrally registered chemotherapy protocol system at 46 hospitals from April 2010 to March 2020 will be identified (~48,850 patients). Key exclusion criteria include active double cancer and inadequate data extraction. Data will be obtained through electronic medical records, diagnosis procedure combination data, medical prescription data, and the national cancer registration system that includes sociodemographic variables, diagnostic and laboratory tests, concomitant drug prescriptions, cost, and overall survival. Kaplan–Meier estimates will be calculated for time-to-event analyses. Stratified/conventional Cox proportional hazards regression analyses will be conducted to examine the relationships between overall survival and related factors. Our findings provide important insights for future research directions, policy initiatives, medical guidelines, and clinical decision-making.

Safety and Immunogenicity of mRNA Vaccines Against Severe Acute Respiratory Syndrome Coronavirus 2 in Patients With Lung Cancer Receiving Immune Checkpoint Inhibitors: A Multicenter Observational Study in Japan

INTRODUCTION

Patients with cancer have been prioritized for vaccination against severe acute respiratory syndrome coronavirus 2. Nevertheless, there are limited data regarding the safety, efficacy, and risk of developing immune-related adverse events (irAEs) associated with mRNA vaccines in patients with lung cancer, especially those being actively treated with immune checkpoint inhibitors.

METHODS

This multicenter observational study was conducted at nine hospitals in Japan. Patients with lung cancer (≥20 y) actively treated with immune checkpoint inhibitors between 4 weeks prefirst vaccination and 4 weeks postsecond vaccination were enrolled. The primary end point was the incidence of irAEs of any grade on the basis of an assumed incidence without vaccination rate of 35%. Immunogenicity was assessed by measuring anti-spike (S)-IgG antibody levels against severe acute respiratory syndrome coronavirus 2.

RESULTS

A total of 126 patients with lung cancer (median age, 71 y; interquartile range, 65-74) were enrolled from May to November 2021 and followed up until December 2021. There were 26 patients (20.6%, 95% confidence interval: 13.9%-28.8%) and seven patients (5.6%, 95% confidence interval: 2.3%-11.1%) who developed irAEs of any grade pre- and postvaccination, respectively, which was lower than the predicted incidence without vaccination. None of the patients experienced exacerbation of preexisting irAE postvaccination. S-IgG antibodies were seroconverted in 96.7% and 100% of the patients with lung cancer and controls, respectively, but antibody levels were significantly lower in patients with lung cancer (p < 0.001).

CONCLUSIONS

Patients with lung cancer who were actively treated with ICIs were safely vaccinated without an increased incidence of irAEs; however, their vaccine immunogenicity was lower. This requires further evaluation.

Decreased plasma acetaminophen glucuronide/acetaminophen concentration ratio warns the onset of acetaminophen-induced liver injury

Acetaminophen (APAP)-induced liver injury (AILI) is the most common cause of acute liver failure. Although the mechanisms that trigger AILI are well known, it is less understood how to halt AILI progression and facilitate liver recovery. Therefore, it is necessary to understand the pathophysiology of APAP hepatotoxicity in patients and to examine predictive/preventive markers. In a clinical study, we had a case in which aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels increased in a patient with a low ratio of APAP glucuronide concentration (AP-G)/APAP plasma concentration. Then a reverse translational study was conducted for clarifying this clinical question. The relationship between plasma AP-G/APAP concentration ratio and the levels of AST and ALT was examined by in vivo and in vitro experiments. In in vivo experiments, 10-week-old rats showed lower UGT activity, lower AP-G/APAP concentration ratios, and higher AST and ALT levels than 5-week-old rats. This suggests an inverse correlation between the AP-G/APAP concentration ratio and the AST, ALT levels in APAP-treated rats. Furthermore, as a result of the in vitro experiment, it was confirmed that the cell viability decreased when the AP-G/APAP concentration ratio in the culture medium decreased. Since the decrease in the plasma AP-G/APAP concentration ratio appears earlier than the increase of AST and ALT levels, the ratio might be a presymptomatic marker of AILI. When APAP is used for a long time, it is recommended to perform therapeutic drug monitoring of the AP-G/APAP concentration ratio, which is a predictive/preventive marker of AILI.

Antibody responses to SARS-CoV-2 nucleocapsid and spike proteins in hospitalized patients with COVID-19: A multicenter, retrospective, cross-sectional study in Japan

BACKGROUND

There are many commercially available automated assays for assessing coronavirus disease 2019 (COVID-19) immune responses; however, owing to insufficient data, their validities remain unknown. Here, we examined antibody responses during acute-phase COVID-19 using four assays that detect anti-spike protein IgM (S-IgM), anti-nucleocapsid protein IgG (N-IgG), anti-spike protein total Ig (S-total Ig), and anti-spike protein IgG (S-IgG).

METHODS

We measured antibody levels in 1154 serum samples collected from 286 hospitalized patients with confirmed COVID-19 by a gene amplification method between February and December 2020 in Japan. Sera from 860 healthcare workers were used as negative controls.

RESULTS

The antibody positivity rates increased on week 2, peaked, and then started to plateau by the beginning of week 3 after symptom onset. On week 1, there were some significant differences in seropositivity rates between assays (p = 0.032): 14.9% (11.0%-19.4%) for S-IgM and 8.9% (6.0%-12.7%) for N-IgG. The seropositivity for the S-total Ig (10.6% [7.3%-14.6%]) assay was considerably better than that for the S-IgG (6.9% [4.3%-10.4%]) assay, although the difference was not statistically significant (p = 0.150). The levels of S-IgM antibodies and the three others peaked on weeks 3 and 5, respectively. All four assays showed high specificities (>99%).

CONCLUSIONS

All four assays had good specificities and were suitable for seropositivity detection after week 3 of symptom onset. Assays of IgM alone or total Ig (containing IgM) were better than those of IgG alone as an adjunct serological test for early-stage COVID-19 diagnosis, albeit the use of a serological assay alone is insufficient.

A Case of Anti-CRMP5 Paraneoplastic Neurological Syndrome Induced by Atezolizumab for Small Cell Lung Cancer

We herein report a 76-year-old man who developed irritability and forgetfulness 5 months after the introduction of atezolizumab for the treatment of small cell lung cancer (SCLC). Brain magnetic resonance imaging showed lesions of the striatum, and an investigation of the serum revealed a high titer of anti-CRMP5 antibody. After stopping atezolizumab and starting steroid pulse therapy, these clinical features improved. Given these findings, it is considered that CRMP5-assciated striatal encephalitis was induced by atezolizumab in this case with SCLC.

Multidisciplinary Lung Cancer Tumor Board Connecting Eight General Hospitals in Japan via a High-Security Communication Line

PURPOSE

The complexity of lung cancer treatment is rapidly increasing, necessitating the use of multidisciplinary approaches for improving outcomes. Although it is common for institutions to have their own tumor boards, tumor boards connecting several general hospitals, and therefore allowing for more diverse opinions, are not prevalent.

MATERIALS AND METHODS

A tumor board connecting eight hospitals was formed to discuss patients for whom formulating a treatment strategy was difficult. Physicians and hospital staff accessed a high-security communication line via LiveOn ( Japan Media Systems Corporation, Tokyo, Japan), which is completely isolated from the Internet and password protected, that enables each hospital to share the electronic medical records and images of relevant patients at other hospitals on desktop computers in real time. The lung cancer tumor board began in April 2017 and has since been held every Tuesday evening for 1 hour. Preparatory records containing the age, sex, histology, TNM classification, background, and discussion points for each patient are created before each tumor board meeting. After the tumor board discussion, all conclusions and related articles used in the board are added to the minutes, which are finalized as Microsoft Word files, consolidated, and archived. These files can be retrieved later using key words.

RESULTS

From April 2017 to June 2018, 202 patients were discussed. Although TNM classification was not changed for any patient, diverse opinions led to a change in the proposed strategy for 49 of 202 patients.

CONCLUSION

The multidisciplinary tumor board was useful in obtaining various opinions from the perspectives of different experts. This should be evaluated in a prospective study.

Final Results from a Phase II Trial of Osimertinib for Elderly Patients with Epidermal Growth Factor Receptor t790m-Positive Non-Small Cell Lung Cancer That Progressed during Previous Treatment

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are used for treating EGFR-mutated lung cancer, and osimertinib is effective in cases that acquired T790M mutations after treatment with the first- and second-generation EGFR-TKIs. However, no study has evaluated its safety and efficacy in older patients. This phase II trial (jRCTs071180002) evaluated osimertinib in T790M mutation-positive Japanese patients who were ≥75 years old and had experienced relapse or progression after previous EGFR-TKI treatment. Our previous report that enrolled 36 patients showed the overall response rate (58.3%) and disease control rate (97.2%), while this report describes the results for the progression-free survival (PFS), overall survival (OS), and safety analyses. The median PFS was 11.9 months (95% confidence interval (CI): 7.9-17.5), and the median OS was 22.0 months (95% CI: 16.0 months-not reached). The most frequent adverse events were anemia/hypoalbuminemia (27 patients, 75.0%), thrombocytopenia (21 patients, 58.3%), and paronychia/anorexia/diarrhea/neutropenia (15 patients, 41.7%). Pneumonitis was observed in four patients (11.1%), including two patients (5.6%) with Grade 3-4 pneumonitis. These results suggest that osimertinib was relatively safe and effective for non-small cell lung cancer that acquired T790M mutations after previous EGFR-TKI treatment, even among patients who were ≥75 years old.

Osimertinib in Elderly Patients with Epidermal Growth Factor Receptor T790M-Positive Non-Small-Cell Lung Cancer Who Progressed During Prior Treatment: A Phase II Trial

LESSONS LEARNED

Non-small-cell lung cancer (NSCLC) represents 85% of lung cancer in elderly patients.In the present study performed in the 36 elderly subjects with epidermal growth factor receptor (EGFR) T790M mutation-positive NSCLC, osimertinib 80 mg demonstrated statistically significant improvement in the objective response rate, which was comparable to those in the nonelderly population.Osimertinib appears to be an effective and safe treatment option in elderly patients with advanced NSCLC with EGFR mutation; further research in larger scale is warranted.

BACKGROUND

Previous findings suggest the possibility of relatively safe use of osimertinib for patients with T790M-positive non-small-cell lung cancer (NSCLC), with few serious adverse events for the elderly in comparison with conventional endothelial growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), and with an antitumor effect.

METHODS

This phase II study was performed to prospectively investigate the efficacy and safety of osimertinib for elderly patients aged ≥75 years with ineffective prior EGFR TKI treatment or with recurrence in T790M EGFR TKI resistance mutation-positive NSCLC.

RESULTS

A total of 36 patients were included in the analyses. Among the 36 subjects, 63.9% were female, with mean age of 79.9 years. The objective response rate (ORR) was 58.3% (95% confidence interval [CI], 42.2%-72.9%), demonstrating statistically significant efficacy of osimertinib (p = .0017). The median duration of response (DOR) was 27.9 weeks (95% CI, 21.1-82.0). Complete response (CR) and partial response (PR) were 2.8% and 55.6%, respectively. Disease control rate (DCR) was 97.2%. A waterfall plot revealed that 33 (91.6%) subjects exhibited tumor shrinkage during treatment, including 12 of 14 subjects who had stable disease (SD). All adverse events were not reason for discontinuation of the study drug.

CONCLUSION

Osimertinib may be an effective and safe treatment option in elderly patients with advanced NSCLC with EGFR mutation.

Human herpesvirus 6 encephalitis in patients administered mycophenolate mofetil as prophylaxis for graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Human herpesvirus 6 (HHV-6) encephalitis is a known life-threatening complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, few studies have focused on the occurrence of HHV-6 encephalitis in patients receiving mycophenolate mofetil (MMF) combined with a calcineurin inhibitor as prophylaxis for graft-versus-host disease (GVHD). This study aimed to investigate the impact of MMF administered for GVHD prophylaxis in the occurrence of HHV-6 encephalitis after allo-HSCT and the characteristics of this condition.

METHODS AND RESULTS

We retrospectively analyzed 73 patients who underwent allo-HSCT (83 transplants) at our hospital between April 2010 and December 2015. MMF (2-3 g/d) was administered along with a calcineurin inhibitor. Seven patients (8.0%) developed encephalitis due to HHV-6. The median period from allo-HSCT to the onset of HHV-6 encephalitis was 23 days (range, 17-98 days). The cumulative incidence of HHV-6 encephalitis on day 100 after treatment was 12% and 6% in patients who underwent cord blood transplantation (CBT) and non-CBT (ie, bone marrow transplantation and peripheral blood stem cell transplantation), respectively (P = 0.344). Neurological symptoms of encephalitis were more severe in non-CBT cases than those in CBT cases. All patients diagnosed with HHV-6 encephalitis were treated with ganciclovir or foscarnet. None of the enrolled patients died from HHV-6 encephalitis.

CONCLUSIONS

Mycophenolate mofetil may have the potential to increase the frequency of severe HHV-6 encephalitis in patients undergoing CBT and non-CBT. Thus, MMF should be administered with caution, and patients should be monitored closely for HHV-6 encephalitis even those who did not undergo CBT.

Loss of CD45 expression at relapse of acute myeloid leukemia

A 49-year-old female was initially diagnosed with acute myeloid leukemia (AML) M4 with a CD45＋CD13＋CD33＋CD34-HLA-DR＋ immunophenotype. She underwent allogeneic bone marrow transplantation, but the disease recurred. The bone marrow was infiltrated with 87.0% blasts negative for myeloperoxidase (MPO) staining. Immunophenotyping by flow cytometry identified the presence of a CD45-negative blast population. These blasts exhibited a CD13＋CD33＋CD19-CD10-CD34-HLA-DR- immunophenotype. The lack of CD45 expression is often observed in B-cell acute lymphoblastic leukemia, whereas CD45-negative AML is extremely rare; only one older male with AML-M0 has been reported. In the present case, the CD45-negative blasts had an MPO-CD13＋CD33＋ phenotype, which is similar to AML-M0.

Central nervous system relapse of Whipple's disease

A 50-year-old man presented with a 12 kg weight loss in 8 months. Upper gastrointestinal endoscopy findings showed strong erosion and diffuse bleeding in the duodenum. Histopathological findings showed PAS staining-positive macrophages consistent with Whipple's disease. He was treated with trimethoprim-sulfamethoxazole. His condition initially improved. However, during his 6-year course of treatment he developed a central nervous system relapse. Tropheryma whipplei DNA was detected by a polymerase chain reaction in his cerebrospinal fluid. This relapse was successfully treated with ceftriaxone sodium (CTRX). We considered that as initial therapy for Whipple's disease, it would be important to administer CTRX for at least a few months, due to its high translatability to CSF.

[Hyponatremia caused by pituitary metastasis of lung cancer]

A 57-year-old man was admitted with headache, vomiting, and bloody sputum. We diagnosed large cell lung cancer T4N2M1 (pituitary metastasis), Stage IV. When hospitalized, low values of cortisol and hyponatremia were found. A hormone stimulation test was performed, because we suspected hypopituitarism. The reaction of adrenocorticotropic hormone (ACTH) to the corticotropin-releasing hormone (CRH) loading test was good, but the reaction of serum cortisol was minimal. After corticosteroid administration, his serum sodium normalized. Limited ACTH reserve according to insufficient pituitary function was suggested as a cause of the hyponatremia. He received gamma-knife therapy, however his pituitary gland tumor did not decrease in size. Clinical symptoms such as visual field disturbance, oculomotor paresis, and visual impairment progressed, and he died about 5 months later. We report a case of hyponatremia in a patient with pituitary metastasis of lung cancer, as it is comparatively rare.

[Pneumatosis cystoides intestinalis in a patient with lung cancer]

We report a case of pneumatosis cystoides intestinalis (PCI) in a patient with lung cancer. A 60-year-old woman was admitted with multiple lung tumors and multiple brain tumors. She was given steroid hormones to reduce her brain edema. Total resection of a brain tumor yielded a pathological diagnosis of metastatic squamous cell carcinoma. During treatment, X-ray and CT images revealed intestinal pneumatosis and free air in the abdominal cavity, but a physical examination revealed no abnormal findings. She was given a diagnosis of PCI, and received conservative treatment. Her intestinal gas cysts and intra-abdominal free air disappeared spontaneously. PCI is an uncommon but important condition in which gas is found in a linear or cystic form in the submucosa or subserosa of the bowel wall. It is important to consider PCI as a possible complication in lung cancer patients who are given steroid hormones and systemic chemotherapy in the long-term.

Clinical and neuropathologic variation in neuronal intermediate filament inclusion disease

BACKGROUND

Recently described neuronal intermediate filament inclusion disease (NIFID) shows considerable clinical heterogeneity.

OBJECTIVE

To assess the spectrum of the clinical and neuropathological features in 10 NIFID cases.

METHODS

Retrospective chart and comprehensive neuropathological review of these NIFID cases was conducted.

RESULTS

The mean age at onset was 40.8 (range 23 to 56) years, mean disease duration was 4.5 (range 2.7 to 13) years, and mean age at death was 45.3 (range 28 to 61) years. The most common presenting symptoms were behavioral and personality changes in 7 of 10 cases and, less often, memory loss, cognitive impairment, language deficits, and motor weakness. Extrapyramidal features were present in 8 of 10 patients. Language impairment, perseveration, executive dysfunction, hyperreflexia, and primitive reflexes were frequent signs, whereas a minority had buccofacial apraxia, supranuclear ophthalmoplegia, upper motor neuron disease (MND), and limb dystonia. Frontotemporal and caudate atrophy were common. Histologic changes were extensive in many cortical areas, deep gray matter, cerebellum, and spinal cord. The hallmark lesions of NIFID were unique neuronal IF inclusions detected most robustly by antibodies to neurofilament triplet proteins and alpha-internexin.

CONCLUSION

NIFID is a neuropathologically distinct, clinically heterogeneous variant of frontotemporal dementia (FTD) that may include parkinsonism or MND. Neuronal IF inclusions are the neuropathological signatures of NIFID that distinguish it from all other FTD variants including FTD with MND and FTD tauopathies.

[The salvage regimen for patients with advanced non-small cell lung cancer who failed prior chemotherapy: once-daily single oral agent Iressa]

BACKGROUND

To summarize the effect of Iressa for refractory patients with advanced non small cell lung cancer (NSCLC) failed to prior chemotherapy.

METHODS

Thirty-one patients, with unresectable stage IIIB or IV NSCLC who had disease progression or relapse after prior chemotherapy using platinum-based regimen for at least 2 cycles, were admitted to the Osaka Prefectural Hobikino Hospital. Iressa 250 mg was administered once a day until disease progression was noted. Weekly chest x-ray and monthly CT scan were performed for response assessment each month.

RESULTS

Among the 31 patients, one complete response (CR) and 7 partial responses (PR) were observed. CR rate was 3.2% (95% confidence interval: 0-17%), PR rate 22.6% (95% confidence interval: 10%-41%), disease control rate including both tumor responses and stable disease was 80.6% (95% confidence interval: 52%-92%). The rate of symptoms relieves was 51.6% (95% confidence interval: 33%-70%), the most effective symptoms being cough and pain. The median time to improved symptoms was 14 days. The most common adverse events were grade I or II skin rash and diarrhea which were readily manageable and reversible. No patients were withdrawn due to the adverse events

CONCLUSIONS

Monotherapy using Iressa is effective and tolerable for the patients with advanced NSCLC who failed prior chemotherapy.

Age-dependent synuclein pathology following traumatic brain injury in mice

Synucleins (Syn), a family of synaptic proteins, includes alpha-Syn, which plays a pivotal role in Parkinson's disease and related neurodegenerative diseases (synucleinopathies) by forming distinct brain pathologies (Lewy bodies and neurites). Since traumatic brain injury (TBI) is a poorly understood risk factor for Parkinson's disease, we examined the effects of TBI in the young and aged mouse brain on alpha-, beta-, and gamma-Syn. Immunohistochemical analysis showed that brains from sham-injured young and aged mice had normal alpha- and beta-Syn immunoreactivity (IR) in neuropil of cortex, striatum, and hippocampus with little or no gamma-Syn IR. At 1 week post TBI, the aged mouse brain showed a transient increase of alpha- and beta-Syn IR in the neuropil as well as an induction of gamma-Syn IR in subcortical axons. This was associated with strong labeling of striatal axon bundles by antibodies to altered or nitrated epitopes in alpha-Syn as well as by antibodies to inducible nitric oxide synthase. However, these TBI-induced changes disappeared by 16 weeks post TBI, and altered Syn IR was not seen in young mice subjected to TBI nor in alpha-Syn knockout mice while Western blots confirmed that TBI induced transient alterations of alpha-Syn in the mouse brains. This model of age-dependent TBI-induced transient alterations in alpha-Syn provides an opportunity to examine possible links between TBI and mechanisms of disease in synucleinopathies.

Ultrastructural evidence for differential axonal sprouting in the striatum after thermocoagulatory and aspiration lesions of the cerebral cortex in adult rats

Thermocoagulation of pial blood vessels overlying the cerebral cortex induces an ischemic degeneration of the cortex. We have previously shown with anatomical tracing techniques that thermocoagulatory lesions of the sensorimotor cortex trigger a robust axonal sprouting of contralateral cortical neurons into the denervated striatum. Similar sprouting was not observed after acute aspiration lesions of the same cortical region. We have now examined immunostaining for the growth-associated protein (GAP)-43 at the ultrastructural level after both types of lesions. A modest increase in growth cone-like structures was observed just below the corpus callosum after both lesions. However, GAP-43-positive growth cone-like structures were markedly increased in the denervated dorsolateral striatum only after thermocoagulatory lesions. In contrast, no significant increase in growth cone immunostaining was found in the dorsolateral striatum after aspiration lesions, confirming the absence of axonal sprouting in the dorsolateral striatum in this condition. Corticostriatal inputs make asymmetric synapses with dendritic spines of striatal neurons. As expected, the density of asymmetric synapses was markedly decreased in the dorsolateral striatum after aspiration lesions. However, it was not different from control after thermocoagulatory lesions that removed the same cortical area. The density of symmetric synapses was decreased after both types of lesions at 16 but not 42 days post-surgery. These data reveal that robust axonal and synaptic remodeling can occur in the dorsolateral striatum of adult rats after ischemic lesions of the cerebral cortex and further demonstrate marked differences in the degree of anatomical plasticity induced by two different types of cortical lesions.

Increased lipid peroxidation precedes amyloid plaque formation in an animal model of Alzheimer amyloidosis

Oxidative stress is a key feature in the Alzheimer's disease (AD) brain and manifests as lipid peroxidation (LPO). Isoprostanes (iPs) are specific and sensitive markers of in vivo LPO. To determine whether amyloid beta (Abeta) deposition in vivo is associated with increased LPO, we examined iP levels in a transgenic mouse model (Tg2576) of AD amyloidosis. Urine, plasma, and brain tissues were collected from Tg2576 and littermate wild-type (WT) animals at different time points starting at 4 months of age and continuing until 18 months of age. Levels of urinary 8,12-iso-iPF(2alpha)-VI were higher in Tg2576 than in WT animals as early as 8 months of age and remained this high for the rest of the study. A similar pattern was observed for plasma levels of 8,12-iso-iPF(2alpha)-VI. Homogenates from the cerebral cortex and hippocampus of Tg2576 mice had higher levels of 8,12-iso-iPF(2alpha)-VI than those from WT mice starting at 8 months of age. In contrast, a surge of Abeta 1-40 and 1-42 levels as well as Abeta deposits in Tg2576 mouse brains occurred later, at 12 months of age. A direct correlation was observed between brain 8,12-iso-iPF(2alpha)-VI and Abeta 1-40 and 1-42. Because LPO precedes amyloid plaque formation in Tg2576 mice, this suggests that brain oxidative damage contributes to AD pathogenesis before Abeta accumulation in the AD brain.

Frontotemporal dementia with novel tau pathology and a Glu342Val tau mutation

It is unclear how tau gene mutations cause frontotemporal dementia (FTD) with parkinsonism linked to chromosome 17 (FTDP-17), but those in exon 10 (E10) or the following intron may be pathogenic by altering E10 splicing, perturbing the normal 1:1 ratio of four versus three microtubule-binding repeat tau (4R:3R tau ratio) and forming tau inclusions. We report on a 55-year old woman with frontotemporal dementia and a family history of FTDP-17 in whom we found a novel E12 (Glu342Val) tau gene mutation, prominent frontotemporal neuron loss, intracytoplasmic tau aggregates, paired helical tau filaments, increased 4R tau messenger RNA, increased 4R tau without E2 or E3 inserts, decreased 4R tau with these inserts, and a 4R:3R tau ratio greater than 1 in gray and white matter. Thus, this novel Glu342Val mutation may cause FTDP-17 by unprecedented mechanisms that alter splicing of E2, E3, and E10 to preferentially increase 4R tau without amino terminal inserts and promote aggregation of tau filaments into cytopathic inclusions.

Inhibition by neuromuscular blocking drugs of norepinephrine transporter in cultured bovine adrenal medullary cells

Pancuronium stimulates the cardiovascular system, whereas vecuronium, a derivative of pancuronium, has far fewer effects. The inhibition of norepinephrine transporter (NET) in the sympathetic nervous system may partly account for the stimulatory actions of pancuronium. To investigate the mechanism of action of pancuronium on NET, we examined the effects of pancuronium on NET activity by using cultured bovine adrenal medullary cells and compared pancuronium with other neuromuscular blocking drugs. Pancuronium (1-300 microM) inhibited desipramine-sensitive [(3)H]norepinephrine (NE) uptake in a concentration-dependent manner. Vecuronium (100-300 microM) and d-tubocurarine (300 microM) also decreased [(3)H]NE uptake but were less potent than pancuronium at clinical concentrations. Succinylcholine had little effect on [(3)H]NE uptake. Saturation analysis showed that pancuronium and vecuronium reduced an apparent maximum velocity (V(max)) of [(3)H]NE uptake without altering Michaelis-Menten constant, indicating noncompetitive inhibition. Pancuronium did not inhibit the specific binding of [(3)H]desipramine to plasma membranes isolated from bovine adrenal medulla. A protein kinase C inhibitor, GF109203X, did not affect the inhibition of [(3)H]NE uptake by pancuronium. Pancuronium enhanced the inhibition of NET induced by ketamine. These results suggest that pancuronium, with clinically relevant concentrations, inhibits NET activity by interacting with a site distinct from the recognition site for NE and the desipramine binding site on the transporter.

IMPLICATIONS

In this study, pancuronium inhibited norepinephrine uptake and was the most potent of the neuromuscular blocking drugs we tested, including pancuronium, vecuronium, d-tubocurarine, and succinylcholine. Pancuronium may affect the sympathetic nervous system by inhibiting the activity of the presynaptic norepinephrine transporter at clinically relevant concentrations.

A role for N-methyl-D-aspartate receptors in the regulation of synaptogenesis and expression of the polysialylated form of the neural cell adhesion molecule in the developing striatum

Striatal development proceeds during a protracted postnatal period in rats. In the dorsolateral striatum, the number of asymmetric synapses, formed mostly by glutamatergic afferents innervating the dendritic spines of medium-sized striatal neurons, increases during the 3rd postnatal week and then rapidly declines before reaching adult levels. The polysialylated form of the neural cell adhesion molecule (PSA-NCAM), which is widely expressed along neuronal membranes early in development, becomes progressively localized to synapses, and is no longer detectable in remaining synapses after synaptic pruning has occurred. Administration of MK-801, an antagonist of N-methyl-D-aspartate receptors, on day 20, either peripherally or locally into the striatum, decreases asymmetric synapse number by 30% and totally abolishes immunolabelling for PSA-NCAM in the dorsolateral striatum.

Activation of extracellular signal-regulated protein kinases is associated with a sensitized locomotor response to D(2) dopamine receptor stimulation in unilateral 6-hydroxydopamine-lesioned rats

Evidence indicates that mitogen-activated protein kinase (MAPK) pathways play a crucial role in the neurobiology of the nervous system. In the present study, dopamine receptor-mediated regulation of extracellular signal-regulated kinases (ERKs) was examined in rats in which the nigrostriatal dopaminergic pathway was unilaterally lesioned by 6-hydroxydopamine (6-OHDA). Subcutaneous injections of the D(2) receptor agonist quinpirole significantly increased tyrosine-phosphorylated ERK1/2 in lesioned striatum, whereas the D(1) receptor agonist SKF38393 failed to activate ERKs. Quinpirole-induced phosphorylation of ERK1/2 was seen as early as 3 min and peaked at 15 min after the challenge. In parallel, striatal ERK kinase activity, measured by the in vitro kinase assay, was increased 2.5-fold on the lesioned side after the administration of quinpirole. Immunohistochemical examination of brain sections after quinpirole administration revealed significant increases in ERK1/2 immunostaining in perinuclear and intranuclear areas of striatal neurons. This increase was much more pronounced on the lesioned than the intact side. Furthermore, quinpirole-induced contralateral rotation was decreased by 48.7 and 50.7%, respectively, when the striatal ERK pathway was selectively inhibited by a single intrastriatal injection of the MAPK/ERK kinase inhibitor PD098059 or after a continuous 7 d intrastriatal infusion of ERK1/2 antisense oligodeoxynucleotide. The results demonstrate, for the first time, that the ERK signaling pathway is activated in denervated striatum in response to stimulation of D(2) dopamine receptors and that the resulting imbalance in striatal ERK activity contributes, at least in part, to neuronal plasticity that underlies D(2) dopamine receptor-mediated contralateral rotation in unilateral 6-OHDA denervated rats.

Age-associated impairment in brain MAPK signal pathways and the effect of caloric restriction in Fischer 344 rats

Mitogen-activated protein kinases (MAPKs) play important roles in cell proliferation, differentiation, and apoptosis. Important functional roles for MAPKs in postmitotic cells have recently been suggested. In the present study, we investigated the effect of aging on the brain ERK (extracellular signal-regulated kinase) and p38 MAPK signaling pathways of Fischer 344 rats. The results show that basal tyrosine-phosphorylated ERK1/ERK2 in cortex of 24-month-old rats was reduced by 36%-59%, compared to 6- and 12-month-old rats (p<.05, 24- vs. 12- or 6-month-old rats). Similarly, the phosphotransferase activities of ERK and p38 MAPK, measured by in vitro immunocomplex kinase assays using myelin basic protein (MBP) as substrate, were shown to be reduced approximately 50% and 59% respectively, in the cerebrocortex of 24-month-old rats (p<.01, 24- vs. 12- or 6-month-old rats). The reductions in basal ERK and p38 MAPK activities are not due to altered protein levels of these kinases as assessed by Western analysis. Immunohistochemically, no age-related differences in ERK expression and cellular distribution were observed However, cytosolic ERK tended to aggregate in brain neurons of aged rats. In contrast brain tyrosine-phosphorylated PLCgamma1 did not change with age. Activation of ERK in response to EGF or PMA was also reduced in cortical brain slices of 24-month-old rats. These results demonstrate an age-associated selective impairment in the MAPK signaling pathways. Moreover, lifelong caloric restriction completely prevented the age-related decrease in basal brain ERK activity and diminished the age-related reduction of p38 MAPK activity. Taken together, these data indicate that ERK and p38 MAPK signaling pathways are impaired in the aged brain and that lifelong caloric restriction modulates these defects in brain intracellular signaling pathways.

Axon pathology in Parkinson's disease and Lewy body dementia hippocampus contains alpha-, beta-, and gamma-synuclein

Pathogenic alpha-synuclein (alphaS) gene mutations occur in rare familial Parkinson's disease (PD) kindreds, and wild-type alphaS is a major component of Lewy bodies (LBs) in sporadic PD, dementia with LBs (DLB), and the LB variant of Alzheimer's disease, but beta-synuclein (betaS) and gamma-synuclein (gammaS) have not yet been implicated in neurological disorders. Here we show that in PD and DLB, but not normal brains, antibodies to alphaS and betaS reveal novel presynaptic axon terminal pathology in the hippocampal dentate, hilar, and CA2/3 regions, whereas antibodies to gammaS detect previously unrecognized axonal spheroid-like lesions in the hippocampal dentate molecular layer. The aggregation of other synaptic proteins and synaptic vesicle-like structures in the alphaS- and betaS-labeled hilar dystrophic neurites suggests that synaptic dysfunction may result from these lesions. Our findings broaden the concept of neurodegenerative "synucleinopathies" by implicating betaS and gammaS, in addition to alphaS, in the onset/progression of PD and DLB.

N-methyl-D-aspartate receptor blockade affects polysialylated neural cell adhesion molecule expression and synaptic density during striatal development

Glutamatergic neurons innervate the striatum and form asymmetric synapses with the dendritic spines of striatal efferent neurons. The role of glutamate in striatal development, however, remains largely unknown. Previous studies have shown a dramatic increase in the density of asymmetric synapses in the rat striatum during the third postnatal week, followed by a decrease to adult levels by postnatal day 25. At the same time, the highly polysialylated form of the neural cell adhesion molecule becomes progressively restricted to synaptic regions and then disappears. We have now examined the effects of antagonists of the N-methyl-D-aspartate subtype of glutamatergic receptors on the expression of the polysialylated form of the neural cell adhesion molecule and on synaptic density during this late period of striatal development. Peripheral administration of the N-methyl-D-aspartate receptor antagonist dizocilpine maleate markedly decreased immunoreactivity for the highly polysialylated form of the neural cell adhesion molecule in the dorsolateral striatum and cerebral cortex when drug treatment included postnatal day 20, but not earlier in development. This effect was regionally specific and loss of the polysialylated neural cell adhesion molecule in the striatum was reproduced by the local administration of dizocilpine maleate, DL-2-amino-5-phosphonovalerate or ketamine on postnatal day 20. Quantitative ultrastructural studies of synaptic density with the physical disector method performed after one of the regimens inducing loss of the polysialylated neural cell adhesion molecule (postnatal days 18-20) revealed a 30% decrease in asymmetric synapses in the dorsolateral striatum of treated rats. Symmetric synapses, which presumably do not use glutamate, were not affected. The data indicate that N-methyl-D-aspartate receptors play a role in the late stages of synaptogenesis in the striatum and suggest that a subset of synapses expressing immunoreactivity for the highly polysialylated form of the neural cell adhesion molecule may be dependent on N-methyl-D-aspartate receptor stimulation during a critical period of striatal development.

Mutant and wild type human alpha-synucleins assemble into elongated filaments with distinct morphologies in vitro

alpha-Synuclein is a soluble presynaptic protein which is pathologically redistributed within intracellular lesions characteristic of several neurodegenerative diseases. Here we demonstrate that wild type and two mutant forms of alpha-synuclein linked to familial Parkinson's disease (Ala30 --> Pro and Ala53 --> Thr) self-aggregate and assemble into 10-19-nm-wide filaments with distinct morphologies under defined in vitro conditions. Immunogold labeling demonstrates that the central region of all these filaments are more robustly labeled than the N-terminal or C-terminal regions, suggesting that the latter regions are buried within the filaments. Since in vitro generated alpha-synuclein filaments resemble the major ultrastructural elements of authentic Lewy bodies that are hallmark lesions of Parkinson's disease, we propose that self-aggregating alpha-synuclein is the major subunit protein of these filamentous lesions.

Synaptogenesis and ultrastructural localization of the polysialylated neural cell adhesion molecule in the developing striatum

The polysialylated neural cell adhesion molecule (PSA-NCAM) plays a role in axonal development and synaptic plasticity. Its pattern of expression is regulated temporally and topographically in the brain during development. However, it is unclear whether or not its subcellular location also changes. We have examined PSA-NCAM expression in relation to synapse formation in the developing rat striatum with immunohistochemistry and electron microscopy. Early in development, PSA-NCAM was present along the cytoplasmic membranes of neurons and in growth cones. PSA-NCAM expression became progressively confined to pre- and postsynaptic elements as neurons matured morphologically. Confirming previous results, a marked increase in the density of asymmetric synapses determined by using the physical dissector method was observed in the dorsolateral striatum between postnatal day 14 (P14) and P18. It was followed by a reduction between P18 and P25, when asymmetric synapse density reached adult levels. In contrast, the density of symmetric synapses had surpassed adult levels by P14. In the dorsomedial striatum, the density of asymmetric and symmetric synapses was similar at P18, at P25, and in adults. PSA-NCAM was associated with most asymmetric and symmetric synapses at P14 and P18 and was expressed in both pre- and postsynaptic elements of a majority (P14) or approximately half (P18) of the synapses. Most synapses lost PSA-NCAM expression between P18 and P25 in the dorsolateral striatum and between P25 and adult in the dorsomedial striatum. The data indicate that PSA-NCAM expression becomes restricted topographically during neuronal maturation but remains strategically associated with developing synapses during late postnatal development in the striatum.

D1 dopamine receptor agonists mediate activation of p38 mitogen-activated protein kinase and c-Jun amino-terminal kinase by a protein kinase A-dependent mechanism in SK-N-MC human neuroblastoma cells

We investigated the effects of D1 dopamine receptor stimulation on the activation of mitogen-activated protein kinases (MAPKs) in SK-N-MC human neuroblastoma cells. We found that the D1 dopamine receptor agonist SKF38393 induced similar time- and dose-related activation of p38 MAPK and c-Jun amino-terminal kinase (JNK), whereas extracellular signal-regulated kinase activity was not affected by D1 dopamine receptor stimulation. Maximal stimulation of p38 MAPK and JNK was observed after a 15-min incubation with 100 microM SKF38393. In contrast, 10 microM quinpirole, a D2 dopamine receptor agonist, did not activate p38 MAPK or JNK. Treatment of cells with 10 muM SCH23390, a D1 dopamine receptor antagonist, significantly inhibited the activation of both kinases by SKF38393. These results indicate that activation of the p38 MAPK and JNK signaling pathways is mediated by dopamine D1 receptors in SK-N-MC neuroblastoma cells. Furthermore, dibutyryl-cAMP mimicked SKF38393-mediated stimulation of p38 MAPK and JNK. Inhibition of protein kinase A by 1 microM H-89 or 10 microM adenosine 3', 5'-cyclic monophosphothioate (Rp-isomer, triethylammonium salt) markedly attenuated the activation of p38 MAPK and JNK. Conversely, the selective protein kinase C inhibitor calphostin C did not block D1 dopamine receptor-stimulated activation of p38 MAPK and JNK. These results demonstrate, for the first time, that the Gs-coupled D1 dopamine receptor activates the p38 MAPK and JNK signaling pathways by a protein kinase A-dependent mechanism.

Regulation of the polysialylated form of the neural cell adhesion molecule in the developing striatum: effects of cortical lesions

Early in development, the polysialylated form of the neural cell adhesion molecule (PSA-NCAM) is expressed by growth cones, neuronal processes, and neuronal cell bodies. In rat striatum, PSA-NCAM expression becomes progressively restricted to pre- and postsynaptic membranes and is undetectable by postnatal day 25 (P25), i.e., after corticostriatal synaptogenesis. This study examined the effects of cortical lesions performed on P14, when the corticostriatal projection is already primarily unilateral and cortical inputs have not yet formed asymmetric synapses on striatal neurons. Rats were killed on P25, and PSA-NCAM expression was examined by immunoblotting and immunohistochemistry with light and electron microscopy. In contrast to the case in controls, PSA-NCAM expression was maintained in the striatum of lesioned pups. Ultrastructural studies showed that PSA-NCAM was present 1) in growth cone-like structures and neuronal processes and 2) in striatal neurons. Together with the presence of growth cones, the observation that the number of asymmetric synapses was unchanged in the denervated striatum suggests that axonal sprouting occurred in response to the lesion. This was confirmed by axonal labeling in the denervated striatum after injection of Fluoro-Ruby in the contralateral cortex. The data indicate that P14 cortical lesions affect PSA-NCAM expression in the developing striatum 1) by inducing a robust axonal plasticity resulting in the presence of immature presynaptic elements that contain PSA-NCAM and 2) by delaying the loss of PSA-NCAM expression in striatal neurons, suggesting that the lesion affects the time course of striatal maturation.

Pattern of expression of the serotonin2C receptor messenger RNA in the basal ganglia of adult rats

The distribution of the serotonin (5-HT) receptor 5-HT2C mRNA was examined at the single-cell level with in situ hybridization histochemistry and emulsion autoradiography in the basal ganglia and mesolimbic system of adult rats, with focus on the pallidum and the substantia nigra, which receive striatal inputs and play a critical role in basal ganglia function. 5-HT2C receptor mRNA expression was always restricted to a subpopulation of neurons in the regions examined. In the neostriatum, labeled neurons were more numerous in the rostral nucleus accumbens than in the caudal nucleus accumbens and were more numerous in the ventral and ventrolateral caudate-putamen than in the dorsal caudate-putamen, where labeled neurons were restricted to isolated clusters. In striatal target areas, dense labeling in the entopeduncular nucleus (internal pallidum, direct striatal output pathway) contrasted with an absence of labeling in the globus pallidus (external pallidum, indirect striatal output pathway). Double-label in situ hybridization in the substantia nigra revealed coexpression of 5-HT2C receptor mRNA with glutamic acid decarboxylase but not with tyrosine hydroxylase mRNA, indicating that it was restricted to gamma-aminobutyric acid (GABA)ergic neurons. In this region, dense labeling for 5-HT2C mRNA was found in half of the neurons at middle and caudal levels of both the pars compacta and the pars reticulata, with little labeling rostrally. The data suggest that drugs acting on the 5-HT2C receptor could selectively affect discrete neuronal populations in the basal ganglia and mesolimbic systems and indicate a new level of neurochemical heterogeneity among GABAergic neurons of the substantia nigra.