Trifluridine/Tipiracil Plus Bevacizumab for Vulnerable Patients With Pretreated Metastatic Colorectal Cancer: A Retrospective Study (WJOG14520G)

BACKGROUND

Trifluridine/tipiracil (FTD/TPI) plus bevacizumab has shown clinical benefit for metastatic colorectal cancer (mCRC) refractory to standard therapy. However, few data have been available for patients with pretreated mCRC who are intolerant of intensive therapy (vulnerable).

METHODS

We performed a multicenter retrospective study (WJOG14520G; TWILIGHT) of FTD/TPI plus bevacizumab for vulnerable patients with pretreated mCRC. Eligibility criteria included previous chemotherapy (although patients treated with all key cytotoxic agents, a fluoropyrimidine, oxaliplatin, and irinotecan, were excluded) and intolerance of full-dose combination therapy with oxaliplatin or irinotecan at the start of FTD/TPI plus bevacizumab.

RESULTS

The median age of 93 evaluable patients was 79 years (range, 21-90). Intolerance of intensive therapy was attributable to an older age in 60 (65%) patients, serious concomitant disease in 24 (26%) patients, and a poor performance status in 19 (20%) patients. FTD/TPI plus bevacizumab was administered as second-line treatment in 74 (80%) patients and as third- or fourth-line treatment in 19 (20%) patients. The objective response rate was 4.9% (95% confidence interval [CI], 1.4%-12.2%), and the disease control rate was 67.9% (95% CI, 56.6%-77.8%). With a median follow-up time of 21.6 months, median overall survival and progression-free survival were 18.6 months (95% CI, 12.1-23.2) and 6.3 months (95% CI, 5.0-8.3), respectively. Neutropenia of grade ≥3 developed in 50 (54%) patients, whereas 2 (2%) patients experienced febrile neutropenia, and no treatment-related death was observed.

CONCLUSION

Our data show the potential efficacy and acceptable safety profile of FTD/TPI plus bevacizumab for vulnerable patients with pretreated mCRC.

C-reactive protein/albumin ratio is the most significant inflammatory marker in unresectable pancreatic cancer treated with FOLFIRINOX or gemcitabine plus nab-paclitaxel

There are limited absolute biomarkers for determining the prognosis before first- and second-line palliative chemotherapy in unresectable pancreatic cancer (urPC) patients. To find the best prognostic inflammatory marker, we investigated relationships between overall survival (OS) and six inflammatory markers; C-reactive protein/albumin ratio (CAR), neutrophil-lymphocyte ratio (NLR), prognostic nutrition index (PNI), platelet-lymphocyte ratio (PLR), Glasgow prognostic score (GPS), and prognostic index (PI). We examined 255 patients who received gemcitabine + nab-paclitaxel or FOLFIRINOX as first-line chemotherapy and 159 patients who subsequently underwent second-line chemotherapy. First-line patients with lower CAR had better OS compared to those with a higher CAR (hazard ratio 0.57; 95% confidential index 0.42-77; P < 0.01). Similarly, lower NLR (P = 0.01), higher PNI (P = 0.04), lower PLR (P = 0.03), GPS score of 0 (P < 0.01) and PI score of 0 (P < 0.01) were all associated with better OS. CAR demonstrated the best superiority for determining survival prognosis through the use of area under the curve of time-dependent receiver-operating characteristic curves. Furthermore, a lower CAR before second-line therapy exhibited better OS versus higher CAR (P < 0.01). Therefore, CAR might be a useful biomarker for predicting urPC patient prognosis in both first- and second-line chemotherapy.

Conversion Surgery for Unresectable Pancreatic Cancer Treated With FOLFIRINOX or Gemcitabine Plus Nab-paclitaxel

BACKGROUND/AIM

Recent advances in chemotherapy have made significant progress in conversion surgery (CS) for unresectable pancreatic cancer (uPC). However, the success rate and efficacy of CS have not been fully demonstrated in patients with uPC treated with FOLFIRINOX (FFX) or gemcitabine plus nab-paclitaxel (GnP).

PATIENTS AND METHODS

We retrospectively reviewed the records of 318 patients with uPC who received FFX or GnP as first-line chemotherapy. The efficacy in the CS group, defined as undergoing complete resection after chemotherapy, was analyzed, and compared with the non-CS group; then, contributing factors to achieving CS were extracted. We also analyzed differences in the efficacy of CS between locally advanced pancreatic cancer (LAPC) and metastatic pancreatic cancer (MPC).

RESULTS

Overall, CS was achieved in 4.3% of cases, eight patients (13.3%) with LAPC and five (2.1%) with MPC. Contributing factors to CS were LAPC, no liver metastasis, CA19-9 ≤37, and chemotherapy response. After adjusting for these, overall survival was significantly better in the CS group than in the non-CS group [median of 32.9 vs. 11.3 months; adjusted hazard ratio (HR)=0.32; 95% confidence interval (CI)=0.14-0.70; p<0.01]. Median relapse-free survival duration after CS was 19.1 and 18.1 months in the LAPC-CS and MPC-CS group, respectively (p=0.84). The median post-conversion survival was 27.6 months in the entire CS group, 43.8 months in the LAPC-CS group and 21.3 months in the MPC-CS group.

CONCLUSION

CS was achieved in 13.3% of LAPC and 2.1% of MPC cases. If possible, CS can markedly improve prognosis, even in MPC.

Multicenter retrospective study of trifluridine/tipiracil (FTD/TPI) plus bevacizumab (BEV) for vulnerable patients with pretreated metastatic colorectal cancer (mCRC): WJOG14520G (TWILIGHT)

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Background: In the phase III SOLSTICE study, FTD/TPI plus BEV showed similar efficacy to capecitabine plus BEV as first-line treatment for patients with mCRC ineligible for full-dose combination chemotherapy with oxaliplatin [OX] or irinotecan [IRI] (intensive therapy). We evaluated clinical outcomes of FTD/TPI plus BEV as second- or later lines treatment for vulnerable patients, who were defined to be intolerant to intensive therapy. Methods: This was a multicenter retrospective study of vulnerable patients with unresectable mCRC who received FTD/TPI plus BEV as second- or later lines treatment between May 2014 and October 2020. Main eligibility criteria were histologically proven adenocarcinoma, ECOG PS 0-2, prior chemotherapy for unresectable disease, considered intolerant to intensive therapy, and underwent FTD/TPI plus BEV without prior exposure to at least one key cytotoxic agent (fluoropyrimidines [FP], OX, or IRI). Results: Of 96 patients enrolled from 26 Japanese hospitals, 93 patients were evaluable. Patient characteristics were as follows: median age, 79 years (range 21-90); male, 53%; ECOG PS 0-1, 89%; right-sided primary tumor, 30%; primary tumor resection, 86%; RAS mutant, 63%; BRAF mutant, 1%; second-line treatment, 80%; prior exposure to FP 100%, OX 50%, and IRI 15%. Main reasons for intolerance to intensive therapy were older age (65%), poor PS (20%), and renal failure (5%). Initial dose of FTD/TPI was reduced in 30 (32%) patients. The response rate was 5% and disease control rate was 68%. With median follow-up of 21.6 months, the median progression-free survival, time to treatment failure, and overall survival were 6.3, 4.5, and 18.6 months, respectively. Major grade >3 adverse events were neutropenia (54%), anemia (20%), thrombocytopenia (9%), hypertension (7%), and febrile neutropenia (2%). No treatment-related deaths were observed. The treatment was discontinued in 89 patients due to disease progression (n = 72), patient’s refusal (n = 10), and adverse events (n = 6). After FTD/TPI plus BEV, chemotherapies such as regimens including IRI or OX (n = 20), regorafenib (n = 16), and anti-EGFR antibody monotherapy (n = 7) were performed in 42 patients. Conclusions: FTD/TPI plus BEV as second- or later lines treatment for vulnerable patients with mCRC showed promising clinical activity and acceptable safety profile. This study suggested that FTD/TPI plus BEV could be a treatment option for vulnerable patients with pretreated mCRC. Clinical trial information: UMIN000044136 .

Associations of time to return to performance following acute posterior thigh injuries with running biomechanics, hamstring function, and structure in collegiate sprinters: A prospective cohort design

BACKGROUND

The time to return to sport from acute hamstring strain injuries is associated with several functional and structural impairments. However, not all previous studies assessed the preinjury level before acute hamstring strain injuries directly. The purpose of this study was to examine the associations of the time to return to performance following acute hamstring strain injuries with deficits in running biomechanics, hamstring function and structure in collegiate sprinters by a prospective study.

METHODS

Using a prospective cohort design, 72 participants were recruited from a collegiate track and field team. At the preinjury assessment, a 60-m running-specific test, passive straight leg raise test and isometric knee flexion strength test were assessed at the beginning of the competitive season for three consecutive years (2017-2019). Afterwards, postinjury examinations were performed only in sprinters with acute hamstring strain injuries.

FINDINGS

Twelve sprinters strained their hamstring muscle (incidence rate of hamstring strain injuries: 16.7%); the majority (n = 10) were classified as grades 0-2. The running speed deficit of the running-specific test was associated with the time to return to performance as well as the passive straight leg raise test deficit. In the running-specific test, lower-limb kinetic deficits were more strongly associated with the time to return to performance compared to lower-limb kinematic deficits.

INTERPRETATION

A running-specific test may be considered one of the most convenient and valid tests for assessing rehabilitation progress after acute hamstring strain injuries.

VOYAGER (KSCC1902): A single-arm, multicenter, phase II study of early induction of nivolumab during second-line treatment with taxane ± ramucirumab for advanced gastric or gastro-esophageal junction cancer

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Background: Although nivolumab prolonged overall survival in 3rd or later line treatment for advanced gastric cancer in the ATTRACTION-2 study, only a small number of patients respond or achieve stable disease. Previous reports have shown that low tumor burden at the start of treatment was potentially associated with efficacy to immunotherapy in some types of tumors, but it has not been studied in advanced gastric cancer. We conducted a clinical trial to evaluate the early induction of nivolumab. Methods: Eligible patients were unresectable advanced or recurrent gastric or gastro-esophageal junction cancer, histologically confirmed to be adenocarcinoma regardless of PD-L1 expression. Patients who were refractory to or intolerant of fluoropyrimidines had a complete or partial response after at least three cycles of taxane ± ramucirumab, and were confirmed to be either of the following conditions; disease progression by imaging tests, an increase of tumor markers, exacerbation of symptoms, and intolerant of pretreatment. Patients received 240mg/body nivolumab every 2 weeks. The primary endpoint was the rate of progression-free survival (PFS) at 6 months (M), and the secondary endpoints included safety, overall survival (OS), response rate (RR), time to treatment failure (TTF), and duration of response (DOR). Based on assuming a threshold PFS at 6M of 16% and an expected PFS of 30% with the early induction of nivolumab, 39 patients were required for a power of 0.8 with a one-sided α of 0.1. Results: Between September 2019 and February 2021, 42 patients were enrolled in this study. The characteristics of patients were male/female: 28/14, median age: 71 years (range: 39-87), and performance status 0/1/2: 21/19/2. The PFS at 6M was 35.7% (80% confidence interval 26.4-45.1%), which means this trial met the primary endpoint. The median PFS and OS were 4.0M (95%CI:2.3–5.7) and 10.9M (95%CI:9.9–16.0), respectively. Of 34 patients with baseline target legions, RR was 17.5% (all confirmed partial response) and the rate of stable disease was 41.2%. TTF, and DOR were 3.6M (95%CI:2.2–5.1), and 14.3M (95%CI:3.9–14.3), respectively. No new safety signals were observed. Conclusions: This study demonstrated an improvement of PFS at 6M in patients with advanced gastric cancer and might justify the strategy of early induction of nivolumab. Clinical trial information: jRCTs071190025.

Multicenter retrospective study of ramucirumab-containing chemotherapy for gastrointestinal neuroendocrine carcinoma patients previously treated with platinum-based chemotherapy: RAM-NEC study (WJOG13420G)

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Background: Platinum-based systemic chemotherapy (CTx) is recommended for poorly differentiated advanced gastrointestinal neuroendocrine carcinoma (GI-NEC). As second-line CTx various regimens are adopted according to the guidelines of GI adenocarcinoma or small cell lung cancer in daily practice. Recently, some clinical and preclinical reports suggest that vascular endothelial growth factor (VEGF) inhibitors are effective against NEC. In this study, we evaluated the efficacy of ramucirumab (RAM, anti-VEGF receptor 2 antibody)-containing CTx. Methods: We retrospectively evaluated gastric (G-) or colorectal (C-) NEC patients previously treated with first-line platinum-based CTx followed by second-line CTx between March 2015 and June 2020 (G-NEC) or between May 2016 and June 2020 (C-NEC). The main inclusion criteria were ECOG performance status (PS) of 0–2, pathologically diagnosed as G or C- NEC or mixed adenoneuroendocrine carcinoma. We compared the efficacy of RAM-containing CTx as second- or later-line treatment (Group A) with that of CTx without RAM as second-line treatment (Group B). A Cox proportional hazard model and inverse probability weighting of propensity scores were used to adjust the background factors between the two groups. Results: From 25 facilities, 139 patients were included in this study. Group A and B contained 50 (G/C, 43/7 patients) and 89 (G/C, 58/31 patients) patients, respectively. Patient characteristics were as follows (Group A/Group B): median age (range), 70 (28–83)/68 (39–86); ECOG PS 1–2, 66/69%, more than two prior regimens, 46/0%; response to previous platinum-based CTx, 46/38%. The regimen in combination with RAM in Group A was paclitaxel/nab-paclitaxel/FOLFIRI (62/26/12%). Second-line CTx in Group B were commonly amrubicin (58%) and irinotecan (11%). The efficacy (Group A/Group B) after a median follow-up time of 7.5/5.5 months were as follows: median overall survival (mOS), 8.6/5.8 months (HR, 0.68; 95% CI, 0.45–1.01; p = 0.058); median progression-free survival, 4.3/1.9 months (HR, 0.57; 95% CI, 0.39–0.84; p = 0.004); objective response rate, 50/8% ( p < 0.0001); disease control rate, 70/24% ( p < 0.0001); mOS in G-NEC, 8.6/5.3 months (HR, 0.62; 95% CI, 0.39–0.99; p = 0.047); and mOS in C-NEC, 5.4/6.8 months (HR, 0.66; 95% CI, 0.26–1.66; p = 0.378). The most common grade 3 or higher treatment-related adverse event that occurred in more than 5% of patients in Group A was neutropenia (32%). Conclusions: This study suggests that RAM-containing CTx as second- or later-line treatment is effective for GI-NEC patients, especially for G-NEC. Central pathological review and biomarker analyses using pretreated tissue specimens are ongoing. We will present updated data in the congress. Clinical trial information: UMIN000043200.

Relationship between vancomycin-associated nephrotoxicity and the number of combined nephrotoxic agents

Vancomycin is associated with nephrotoxicity; however, the influence of the number of combined nephrotoxic agents on the incidence of vancomycin nephrotoxicity has not been clarified. We investigated patient backgrounds in 148 inpatients who received vancomycin treatment. The patients were divided into nephrotoxicity (n=35) and non-nephrotoxicity (n=113) groups. A comparison of the patient backgrounds in the two groups revealed significant differences in weight, changes in serum creatinine before vancomycin administration, blood urea nitrogen to serum creatinine ratio, length of vancomycin therapy, vancomycin trough concentration, and number of combined nephrotoxic agents. Multiple logistic regression analysis using these six factors as autonomous variables showed that the highest vancomycin trough concentration (odds ratio, 1.080; 95% confidence interval, 1.030-1.140; p = 0.003) and the number of combined nephrotoxic agents (odds ratio, 1.590; 95% confidence interval, 1.120-2.260; p = 0.010) were significantly related to nephrotoxicity.

The TRUSTY study: A randomized phase 2/3 study of trifluridine/tipiracil plus bevacizumab versus irinotecan and fluoropyrimidine plus bevacizumab as second-line treatment in patients with metastatic colorectal cancer

3507

Background: The efficacy of trifluridine/tipiracil (FTD/TPI) plus bevacizumab (BEV) as a later-line treatment for metastatic colorectal cancer (mCRC) has been demonstrated in clinical trials. Therefore, we conducted a randomized phase 2/3 study to determine whether FTD/TPI plus BEV is non-inferior to either FOLFIRI or S-1 and irinotecan plus BEV in terms of overall survival (OS) as second-line treatment in patients with mCRC. Methods: Patients with histologically confirmed mCRC who failed first-line doublet chemotherapy including fluoropyrimidine plus oxaliplatin with either BEV or an anti-EGFR antibody (in cases of RAS wild-type) were eligible. Patients were randomized to receive either FTD/TPI plus BEV (experimental group, BEV 5.0 mg/kg on days 1 and 15, FTD/TPI 35 mg/m2 twice daily on days 1–5 and 8–12 of each 28-day cycle) or either FOLFIRI or S-1 and irinotecan plus BEV (control group). The primary endpoint was the OS. The non-inferiority margin of a hazard ratio (HR) of 1.33 was based on the assumption of a median survival time of 19 months for the control (power 0.80, 1-sided alpha 0.025). The secondary endpoints were the progression-free survival (PFS), response rate (RR), disease control rate (DCR), time to treatment failure, time to post-study treatment failure, proportion of patients receiving post-study treatment, quality of life, and safety. Results: As a result of the interim analysis for futility, the study was terminated in July 2020, and 397 patients were finally enrolled at 65 institutions from October 2017. The baseline characteristics were similar between the groups. The median OS were 14.8 months in the FTD/TPI plus BEV group and 18.1 months in the control group [HR: 1.38; 95% confidence interval (CI): 0.99–1.93; p = 0.5920 for non-inferiority]; non-inferiority of FTD/TPI plus BEV was not demonstrated. The median PFS were 4.5 months in the FTD/TPI plus BEV group and 6.0 months in the control group (HR: 1.45; 95% CI: 1.14–1.84). The RR and DCR were 3.8% and 61.2% in the FTD/TPI plus BEV group, respectively, and 7.1% and 71.7% in the control group, respectively. The proportions of patients receiving post-study treatment in the FTD/TPI plus BEV and control groups were 59.9% and 52.3%, respectively. The main grade 3 or 4 adverse events in the FTD/TPI plus BEV and control groups were neutropenia (65.8% and 41.6%, respectively), diarrhea (1.5% and 7.1%, respectively), and grade 1 or 2 alopecia (3.6% and 24.9%, respectively). Conclusions: FTD/TPI plus BEV did not show non-inferiority to FOLFIRI or S-1 and irinotecan plus BEV as second-line treatment in patients with mCRC. Post hoc subgroup analyses are ongoing to investigate patients who likely benefit from FTD/TPI plus BEV. Clinical trial information: jRCTs031180122.

Eribulin as a first-line treatment for soft tissue sarcoma patients with contraindications for doxorubicin

Doxorubicin is a first-line therapy for patients with unresectable advanced soft tissue sarcoma (STS). However, because of cardiotoxicities, it is not used for patients with cardiac problems. Eribulin has exhibited efficacy for advanced STS in second- or later-line treatments. In the present study, we retrospectively analyzed the efficacy and safety of first-line eribulin therapy for patients with advanced STS unable to receive doxorubicin. Six of 28 patients who received eribulin as any line treatment received eribulin as a first-line treatment. The reasons for avoiding doxorubicin were as follows: cardiac problems for four patients and advanced age for two. Median progression-free survival (PFS) of the patients who received eribulin as first-line and, second or later-line therapy were 9.7 months (95% CI: 1.0-not reached) and 3.9 months (95% CI: 2.7–5.9), which were not significantly different. The reasons for discontinuation of eribulin were disease progression and adverse events (2 fatigue and 1 neuropathy) for three patients each. No treatment-related cardiotoxicity was observed. The findings of this study indicated that eribulin exhibits meaningful efficacy for the patients with contraindications for doxorubicin as a first-line treatment without cardiac adverse events. However, appropriate safety management is necessary because older patients are typically among those intolerable of doxorubicin.

Activation of memory/effector T cells and association between prognosis and OX40-positive T cells in advanced head and neck cancer patients treated with anti-programmed death-1 antibody

35

Background: Anti-programmed death-1 (PD-1) monoclonal antibody, nivolumab, enhances anti-tumor activity by inhibiting the interaction of PD-1 and programmed death-1 ligand 1 and has shown efficacy for platinum-refractory recurrent or advanced head and neck cancer (HNC). However, subsets of immune cells predominantly activated during the period of anti-PD-1 therapy for HNC and specifically associated with the prognosis have not been clarified. Methods: Peripheral blood mononuclear cells of 15 HNC patients treated with nivolumab were prospectively obtained before the initial and second administrations of nivolumab, and at the time of progressive disease (PD). We performed comprehensive analysis of the proportion of immune cell subsets by flow cytometry, including the expression of coinhibitory and costimulatory molecules such as T-cell immunoglobulin and mucin domain 3 (TIM-3), lymphocyte-activation gene 3 (LAG-3), T-cell immunoreceptor with Ig and ITIM domains (TIGIT), B and T lymphocyte attenuator (BTLA), CD28, OX40, inducible T cell costimulator (ICOS). Association between changes in the proportion of the subsets and therapeutic effect were also analyzed. Results: Median progression free survival (PFS) of the whole patients was 96 days (95% CI 70–308). After a single course of nivolumab, patients showed a significant increase in activated central memory and effector subsets of CD4+/CD8+ T cells and activated helper T1 cells (p = 0.0039, 0.0078, 0.0273, 0.0391, 0.0391). A trend of increase of activated effector memory CD4+/CD8+ T cell was observed (p = 0.4961, 0.3594). At the time of PD, effector regulatory T cells, LAG3 positive CD4+/CD8+ T cells, TIM-3 positive CD4+/CD8 T cells and BTLA positive CD4+/CD8+ T cells significantly increased. Significant positive correlations were found between PFS and the proportion of OX40 positive CD4+/CD8+ T cells before nivolumab therapy (p = 0.0239, 0.0134). Conclusions: Nivolumab therapy enhances activation of central memory and effector subsets of CD4+/CD8+ T cells. The expression level of OX40 on T cells was correlated with efficacy of nivolumab therapy in HNC patients.

Suggestion of added value by bevacizumab to chemotherapy in patients with unresectable or recurrent small bowel cancer

PURPOSE

Standard therapy for advanced small bowel adenocarcinoma (SBA) has not yet been established. The present study assessed the efficacy and safety of chemotherapy (CT) in association with molecular targeting approaches for SBA.

METHODS

The histories of 33 advanced SBA patients from six different institutions in Japan, who received CT from 2008 to 2016, were retrospectively examined for background, clinical course and outcome.

RESULTS

Median patient age was 65 years (range 39-83). Primary tumor was located in the duodenum in 21 patients (67%), the ampulla of Vater in three patients (9%), the jejunum in seven patients (21%) and the ileum in one patient (3%). Histologically, well-to-moderately and poorly differentiated adenocarcinoma were identified in 20 (61%) and nine (27%) patients, respectively. Thirteen patients received a single CT regimen, seven patients received two types of CT regimen, and 13 patients received three or more CT regimens. As first-line CT, modified FOLFOX6, capecitabine plus oxaliplatin, and S-1 plus cisplatin were employed in 13, 1, and 4 patients, respectively. The response rate (RR) and median progression-free survival (PFS) were 25% and 6.0 months, respectively. Median overall survival (OS) was 13.0 months. Nine out of the 33 patients received bevacizumab-containing CT and three received cetuximab-containing CT. Median OS of bevacizumab-containing CT patients was 21.9 months. No unexpected serious adverse events were observed.

CONCLUSIONS

The analysis indicates that combination CT for advanced SBA is associated with modest efficacy and safety, and bevacizumab-containing CT may contribute to favorable outcome in these patients.

Subcultured Odontogenic Epithelial Cells in Combination with Dental Mesenchymal Cells Produce Enamel–Dentin-Like Complex Structures

We showed in a previous study that odontogenic epithelial cells can be selectively cultured from the enamel organ in serum-free medium and expanded using feeder layers of 3T3-J2 cells. The subcultured odontogenic epithelial cells retain the capacity for ameloblast-related gene expression, as shown by semiquantitative RT-PCR. The purpose of the present study was to evaluate the potential of subcultured odontogenic epithelial cells to form tooth structures in cell–polymer constructs maintained in vivo. Enamel organs from 6-month-old porcine third molars were dissociated into single odontogenic epithelial cells and subcultured on feeder layers of 3T3-J2 cells. Amelogenin expression was detected in the subcultured odontogenic epithelial cells by immunostaining and Western blotting. The subcultured odontogenic epithelial cells were seeded onto collagen sponge scaffolds in combination with fresh dental mesenchymal cells, and transplanted into athymic rats. After 4 weeks, enamel–dentin-like complex structures were present in the implanted constructs. These results show that our culture system produced differentiating ameloblast-like cells that were able to secrete amelogenin proteins and form enamel-like tissues in vivo. This application of the subculturing technique provides a foundation for further tooth-tissue engineering and for improving our understanding of ameloblast biology.

Perfusion MR Imaging Using a 3D Pulsed Continuous Arterial Spin-Labeling Method for Acute Cerebral Infarction Classified as Branch Atheromatous Disease Involving the Lenticulostriate Artery Territory

BACKGROUND AND PURPOSE

Branch atheromatous disease is a stroke subtype considered a risk factor for early neurologic deterioration. Meanwhile, crossed cerebellar diaschisis is thought to be influenced by the degree and location of supratentorial perfusion abnormalities and is associated with the clinical outcome in the case of an ischemic stroke. In this article, our aim was to clarify the utility of using a whole-brain 3D pulsed continuous arterial spin-labeling method as an imaging biomarker for predicting neurologic severity in branch atheromatous disease.

MATERIALS AND METHODS

Twenty-three patients with branch atheromatous disease in the lenticulostriate artery territory were enrolled. All patients underwent MR imaging, including DWI, 3D-TOF-MRA, and 3D-arterial spin-labeling. We measured the asymmetry index of CBF in the affected area (branch atheromatous disease), the asymmetry index of the contralateral cerebellar hemisphere (crossed cerebellar diaschisis), and the DWI infarct volume in the lenticulostriate artery territory. We also compared each parameter with the initial NIHSS score with the Pearson correlation coefficient.

RESULTS

Among the 23 patients, we found no correlation between NIHSS score and the asymmetry index of CBF in the affected area (branch atheromatous disease) (r = -0.027, P = .724), whereas the asymmetry index of the contralateral cerebellar hemisphere (crossed cerebellar diaschisis) and DWI infarct volumes were significantly correlated with NIHSS score (r = 0.515, P = .012; r = 0.664, P = .001, respectively).

CONCLUSIONS

In patients with branch atheromatous disease, 3D-arterial spin-labeling can detect crossed cerebellar diaschisis, which is correlated with the degree of neurologic severity.

Tissue-specific expression and silencing phenotypes of mitochondrial phosphate carrier paralogues in several insect species

The mitochondrial phosphate carrier gene (PiC) encodes a membrane protein that mediates the supply of inorganic phosphate from the cytosol into the mitochondrial matrix. This substrate-specific transport system plays an important role in efficient ATP synthesis. Mammals appear to have only one PiC with two alternative splicing variants whose functional differences remain unclear. The present study is the first to characterize the multiple genes that encode PiC in insects. Bombyx mori was found to have two PiC paralogues, one ubiquitous and one testis-specific, the latter seeming to be present only in Lepidoptera. Drosophila melanogaster was found to harbour two PiC paralogues, whereas Liriomyza chinensis, another dipteran, has three PiC paralogues. Two PiCs were found to be present in Plautia stali, and silencing either of these genes affected the normal development of P. stali nymphs, although their expression patterns differed amongst tissues. Schistocerca gregaria and Locusta migratoria have two PiC each, with different expression patterns. Tribolium castaneum was found to have only one PiC, which appears to play an essential role in larval development. Thus, although the inorganic phosphate transport system appears to be conserved across eukaryotes, PiC has become specialized in the different tissues of different insect species.

Attosecond dynamical Franz-Keldysh effect in polycrystalline diamond

Short, intense laser pulses can be used to access the transition regime between classical and quantum optical responses in dielectrics. In this regime, the relative roles of inter- and intraband light-driven electronic transitions remain uncertain. We applied attosecond transient absorption spectroscopy to investigate the interaction between polycrystalline diamond and a few-femtosecond infrared pulse with intensity below the critical intensity of optical breakdown. Ab initio time-dependent density functional theory calculations, in tandem with a two-band parabolic model, accounted for the experimental results in the framework of the dynamical Franz-Keldysh effect and identified infrared induction of intraband currents as the main physical mechanism responsible for the observations.

Effective Bone Engineering with Periosteum-derived Cells

Bone augmentation via tissue engineering has generated significant interest. We hypothesized that periosteum-derived cells could be used in place of bone marrow stromal cells (which are widely used) in bone engineering, but the differences in osteogenic potential between these 2 cell types are unclear. Here, we compared the osteogenic potential of these cells, and investigated the optimal osteoinductive conditions for periosteum-derived cells. Both cell types were induced, via bFGF and BMP-2, to differentiate into osteoblasts. Periosteal cells proliferated faster than marrow stromal cells, and osteogenic markers indicated that bone marrow stromal cells were more osteogenic than periosteal cells. However, pre-treatment with bFGF made periosteal cells more sensitive to BMP-2 and more osteogenic. Transplants of periosteal cells treated with BMP-2 after pre-treatment with bFGF formed more new bone than did marrow stromal cells. Analysis of these data suggests that combined treatment with bFGF and BMP-2 can make periosteum a highly useful source of bone regeneration.

Healing of localized gingival recessions treated with a coronally advanced flap alone or combined with an enamel matrix derivative and a porcine acellular dermal matrix: a preclinical study

OBJECTIVE

This study aimed to evaluate the effects of a porcine acellular dermal matrix (PADM) with or without an enamel matrix derivative (EMD) on gingival recession defects treated with a coronally advanced flap (CAF) in dogs.

MATERIALS AND METHODS

Miller class II gingival recession defects (5 mm wide and 7 mm deep) were surgically created on the labial side of bilateral maxillary canines in 12 dogs. After 8 weeks of plaque accumulation, the 24 chronic defects were randomly assigned to one of the following 4 treatments: CAF, CAF with PADM (CAF/PADM), CAF with EMD (CAF/EMD), and CAF with EMD and PADM (CAF/EMD/PADM). The animals were sacrificed 10 weeks after surgery for histologic evaluation.

RESULTS

In all groups, root coverage was obtained to a varying degree. PADM was well incorporated in gingival connective tissue in the CAF/PADM and in the CAF/EMD/PADM groups. The height of newly formed bone was significantly greater in the CAF/EMD/PADM group than in the CAF and CAF/PADM groups. New cementum with periodontal ligament-like tissue was predominantly found in the CAF/EMD and CAF/EMD/PADM groups. The CAF/EMD/PADM group showed the greatest amount of new cementum among the groups examined, although the difference was not statistically significant.

CONCLUSION

Within the limitations of the present study, it can be concluded that CAF/EMD/PADM treatment may promote periodontal regeneration in gingival recession defects.

CLINICAL RELEVANCE

The present results suggest that the combination of EMD and PADM in conjunction with CAF may represent a promising approach for treating single Miller class II gingival recessions.

Adaptive changes of extracellular amino acid concentrations in mouse dorsal striatum by 4-AP-induced cortical seizures

The striatum is a major target of cerebral cortical output. The cortico-striatal projection has been well described, however, the neurochemical changes that occur in the striatum after prolonged cortical hyperactivation remain to be investigated. In this study, extracellular levels of glutamate, GABA, and alanine levels were measured in the dorsal striatum using microdialysis in anesthetized mice at resting condition and during 4-aminopyridine (4-AP)-induced cortical seizures. After topical application of 4-AP on the primary motor cortex that induced cortical seizures, the extracellular level of striatal GABA increased by 40% in 60 min. By contrast, the extracellular level of striatal glutamate decreased by 20%. Moreover, the surface amounts of striatal glutamate/aspartate transporter (GLAST) and glutamate transporter 1 (GLT-1), the major astrocytic high-affinity glutamate transporters, tended to increase by cortical seizures in 60 min, suggesting a recruitment of the glutamate transporters from internal stores. 4-AP also resulted in a steady increase of alanine levels which are thought to reflect glutamate and pyruvate metabolism in neurons and astrocytes. These observations possibly delineate adaptive changes of striatal metabolism by severe cortical seizures.

Effect of interleukin-1beta and dehydroepiandrosterone on the expression of lumican and fibromodulin in fibroblast-like synovial cells of the human temporomandibular joint

Several epidemiological studies have reported that temporomandibular disorders (TMDs) are more prevalent in women than in men. It has recently been proposed that sex hormones such as estrogen, testosterone and dehydroepiandrosterone (DHEA) are involved with the pathogenesis of TMDs. Although studies have investigated the relationship between estrogen and testosterone and the restoration of TMDs, the relationship between DHEA and TMDs is unknown. The synovial tissue of the temporomandibular joint (TMJ) is made up of connective tissue with an extracellular matrix (ECM) composed of collagen and proteoglycan. One proteoglycan family, comprised of small leucine-rich repeat proteoglycans (SLRPs), was found to be involved in collagen fibril formation and interaction. In recent years, the participation of SLRPs such as lumican and fibromodulin in the internal derangement of TMJ has been suggested. Although these SLRPs may contribute to the restoration of the synovium, their effect is still unclear. The purpose of this study was to investigate the effect of DHEA, a sex hormone, on the expression of lumican and fibromodulin in human temporomandibular specimens and in cultured human TMJ fibroblast-like synovial cells in the presence or absence of the pro-inflammatory cytokine interleukin-1beta (IL-1beta). In the in vivo study, both normal and osteoarthritic (OA) human temporomandibular synovial tissues were immunohistochemically examined. In the in vitro study, five fibroblast-like synoviocyte (FLS) cell lines were established from human TMJ synovial tissue of patients with osteoarthritis. The subcultured cells were then incubated for 3, 6, 12 or 24 h with/without IL-1beta (1 ng/mL) in the presence or absence of DHEA (10 μM). The gene expression of lumican and fibromodulin was examined using the real-time polymerase chain reaction (PCR) and their protein expression was examined using immunofluorescent staining. We demonstrated that the expression of lumican differs from that of fibromodulin in synovial tissue and furthermore, that IL-1beta induced a significant increase in lumican mRNA and immunofluorescent staining in FLS compared to cells without IL-1beta. DHEA plus IL-1beta induced a significant increase in fibromodulin, but not in lumican mRNA, compared to DHEA alone, IL-1beta alone and in the absence of DHEA and IL-1beta. In immunofluorescent staining, weaker fibromodulin staining of FLS cells was observed in cells cultured in the absence of both DHEA and IL-1beta compared to fibromodulin staining of cells cultured with DHEA alone, with DHEA plus IL-1beta, or with IL-1beta alone. These results indicate that DHEA may have a protective effect on synovial tissue in TMJ by enhancing fibromodulin formation after IL-1beta induced inflammation. DHEA enhancement of fibromodulin expression may also exert a protective effect against the hyperplasia of fibrous tissue that TGF-beta1 induces. In addition lumican and fibromodulin are differentially expressed under different cell stimulation conditions and lumican and fibromodulin may promote regeneration of the TMJ after degeneration and deformation induced by IL-1beta.

Inhibition of fibrous adhesion formation in the temporomandibular joint of tenascin-C knockout mice

Tenascin-C (TNC) is a large hexameric extracellular matrix glycoprotein that is expressed in developing organs and tumors. It has been reported that TNC is expressed in inflamed synovial membranes and deformed discs of temporomandibular joint (TMJ) disorder. However, the role of TNC in TMJ is not fully known. In this study, the role of TNC in fibrous adhesion formation of TMJ was examined using TNC knockout (TNCKO) mice. Hypermobility was produced by excessive mouth opening method on the TMJ of both wild-type (WT) and TNCKO mice. TMJ wound healing was compared histologically, and the expression of TNC, fibronectin (FN) and α-smooth muscle actin (α-SMA) in the wounded TMJ was examined by immunohistochemical and immunoblot analyses. Based on histologic analysis, fibrous adhesions were observed in the TMJ of both TNCKO and wild-type (WT) mice after excessive mouth opening. However, fibrous adhesion formation in TNCKO mice occurred later than in WT mice. TNC was expressed in the wounded TMJ disc and mandibular fossa. Although FN and α-SMA expression in the TMJ of TNCKO and WT mice was up-regulated after excessive mouth opening, FN and α-SMA protein levels were higher in WT mice at the same time points. In the wounded TMJ, TNC appears to enhance the expression of FN and α-SMA, and a lack of TNC may reduce fibrous adhesion formation in the TMJ. TNC plays an important role in TMJ wound healing, especially for wounds generated by mechanical stress.

Depletion of gangliosides enhances cartilage degradation in mice

OBJECTIVE

Glycosphingolipids (GSLs) are ubiquitous membrane components that play a functional role in maintaining chondrocyte homeostasis. We investigated the potential role of gangliosides, one of the major components of GSLs, in osteoarthritis (OA) pathogenesis.

DESIGN

Both age-associated and instability-induced OA models were generated using GM3 synthase knockout (GM3S(-/-)) mice. A cartilage degradation model and transiently GM3S-transfected chondrocytes were analyzed to evaluate the function of gangliosides in OA development. The amount of each series of GSLs in chondrocytes after IL-1α stimulation was profiled using mass spectrometry (MS).

RESULTS

OA changes in GM3S(-/-) mice were dramatically enhanced with aging compared to those in wild-type (WT) mice. GM3S(-/-) mice showed more severe instability-induced pathologic OA in vivo. Ganglioside deficiency also led to the induction of matrix metalloproteinase (MMP)-13 and ADAMTS-5 secretion and chondrocyte apoptosis in vitro. In contrast, transient GM3S transfection of chondrocytes suppressed MMP-13 and ADAMTS-5 expression after interleukin (IL)-1α stimulation. GSL profiling revealed the presence of abundant gangliosides in chondrocytes after IL-1α stimulation.

CONCLUSION

Gangliosides play a critical role in OA pathogenesis by regulating the expression of MMP-13 and ADAMTS-5 and chondrocyte apoptosis. Based on the obtained results, we propose that gangliosides are potential target molecules for the development of novel OA treatments.

Evaluation of Parkinson disease and Alzheimer disease with the use of neuromelanin MR imaging and (123)I-metaiodobenzylguanidine scintigraphy

BACKGROUND AND PURPOSE

Progressive changes in the substantia nigra pars compacta and locus ceruleus of patients with Parkinson disease and Alzheimer disease visualized by neuromelanin MRI and cardiac postganglionic sympathetic nerve function on (123)I-metaiodobenzylguanidine scintigraphy have not been fully evaluated. We compared the diagnostic value of these modalities among patients with early Parkinson disease, late Parkinson disease, and Alzheimer disease.

MATERIALS AND METHODS

We compared contrast ratios of signal intensity in medial and lateral regions of the substantia nigra pars compacta and locus ceruleus with those of the tegmentum of the midbrain and the pons, respectively, by use of neuromelanin MRI in patients with early Parkinson disease (n = 13), late Parkinson disease (n = 31), Alzheimer disease (n = 6), and age-matched healthy control subjects (n = 20). We calculated heart-to-mediastinum ratios on (123)I-metaiodobenzylguanidine scintigrams after setting regions of interest on the left cardiac ventricle and upper mediastinum.

RESULTS

The signal intensity of the lateral substantia nigra pars compacta on neuromelanin MRI was significantly reduced in early and late Parkinson disease, and that of the medial substantia nigra pars compacta was gradually and stage-dependently reduced in Parkinson disease. The signal intensity of the locus ceruleus was obviously reduced in late Parkinson disease. Signal reduction was not significant in the substantia nigra pars compacta and locus ceruleus of patients with Alzheimer disease. The heart-to-mediastinum ratio on (123)I-metaiodobenzylguanidine scintigrams was stage-dependently reduced in Parkinson disease and normal in Alzheimer disease. The signal intensity ratios in substantia nigra pars compacta and locus ceruleus on neuromelanin MRI positively correlated with the heart-to-mediastinum ratio on (123)I-metaiodobenzylguanidine scintigrams.

CONCLUSIONS

Both neuromelanin MRI and (123)I-metaiodobenzylguanidine scintigraphy can help to evaluate disease progression in Parkinson disease and are useful for differentiating Parkinson disease from Alzheimer disease.

Parenchymal hypointense foci associated with developmental venous anomalies: evaluation by phase-sensitive MR Imaging at 3T

BACKGROUND AND PURPOSE

The risk of hemorrhage in the context of developmental venous anomaly is considered to be very low, but it has never been evaluated by susceptibility-weighted MR imaging at 3T. The goal of the present study was to evaluate the prevalence of hypointense foci (ie, microhemorrhage or cavernous malformation) associated with DVA on phase-sensitive MR imaging, on the basis of principles similar to those of susceptibility-weighted MR imaging, and to evaluate the relationship between the hypointense foci and several factors, such as white matter hyperintense lesions adjacent to DVA on T2-weighted imaging, DVA morphology, and clinical symptoms.

MATERIALS AND METHODS

This study retrospectively evaluated 61 lesions in 59 consecutive patients with DVA who underwent MR imaging including phase-sensitive MR imaging. Two neuroradiologists independently assessed for the presence of hypointense foci and other factors such as DVA location, depth, size, direction of draining vein on phase-sensitive MR imaging, and white matter hyperintense lesion on T2-weighted imaging. Clinical symptoms were also assessed.

RESULTS

Hypointense foci were observed in 62.3% (38/61) of lesions. White matter hyperintense lesion was more frequently observed in patients with hypointense foci (26/38) than in patients without hypointense foci (7/23) (P < .01). There was no significant association between hypointense foci and other factors.

CONCLUSIONS

Our results support the hypothesis that microhemorrhage or cavernous malformation can be related to venous congestion caused by abnormal venous drainage. We conclude that phase-sensitive MR imagingis useful for the detection of microhemorrhage or cavernous malformation in patients with DVA, especially when associated with white matter hyperintense lesion.

Subarachnoid hyperattenuation on flat panel detector-based conebeam CT immediately after uneventful coil embolization of unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

Flat panel detector-based CBCT can provide CT-like images of the brain without transferring patients from the angiography suite to a conventional CT facility. Conventional brain CT after uneventful endovascular treatment sometimes shows focal subarachnoid hyperattenuation with contrast leakage, mimicking SAH. Differentiating this finding from SAH is important for immediate postprocedural medical management. We investigated CBCT for detecting subarachnoid hyperattenuation immediately after coil embolization of unruptured cerebral aneurysms.

MATERIALS AND METHODS

Thirty-six patients with unruptured cerebral aneurysms undergoing CBCT immediately after uncomplicated coil embolization were included. The relationship between the presence of subarachnoid hyperattenuation and total volume of contrast medium injected, aneurysm size and location, and balloon and stent assistance during embolization was investigated. Statistical analyses were performed with the χ(2) test (P < .05).

RESULTS

Nine of the 36 patients (25.0%) showed focal subarachnoid hyperattenuation within the relevant parent artery territory harboring the aneurysm. Subarachnoid hyperattenuation locations included the ipsilateral superior frontal sulcus (n = 5), the bilateral superior frontal sulcus (n = 1), and the ipsilateral superior frontal and precentral sulci (n = 3). Statistically significant differences were observed between the presence of a subarachnoid hyperattenuation and the total volume of contrast medium injected (P < .001) and aneurysm size (P < .05).

CONCLUSIONS

Subarachnoid hyperattenuation can be detected by CBCT immediately after coil embolization for unruptured aneurysms. The increased amounts of contrast medium to be given before CBCT and the specific location of the hyperattenuation may help differentiate benign subarachnoid contrast leakage from SAH.

Stable isotope dilution mass spectrometric assay for PRPP using enzymatic procedures

5-Phosphoribosyl-1-pyrophosphate (PRPP) is an important regulator of de novo purine synthesis. A method for the measurement of PRPP in erythrocytes was designed, which is based on the determination of [(13)C(5)]glutamate derived from [(13)C(5)]glutamine following the utilization of PRPP by the action of amidophosphoribosyltransferase. The present study describes a gas chromatographic-mass spectrometric method for determination of [(13)C(5)]glutamate using [(13)C(2)]glutamate as an internal standard. The methods involved purification by anion-exchange chromatography using a BondElut SAX and derivatization with isobutyl chlorocarbonate in water-methanol-pyridine. Quantitation was performed by selected ion monitoring of the protonated molecular ions in the chemical ionization mode. The intra-day reproducibility in the amounts of [(13)C(5)]glutamate determined was in good agreement with the actual amounts added in erythrocytes. A linear relationship was found between the amount of PRPP added and the amount of [(13)C(5)]glutamate formed from [(13)C(5)]glutamine using amidophosphoribosyltransferase.

Expression of lumican and fibromodulin following interleukin-1 beta stimulation of disc cells of the human temporomandibular joint

Small leucine-rich repeat proteoglycans (SLRP) are present in the extracellular matrix of the temporomandibular joint (TMJ) disc. Lumican and fibromodulin, classified as class 2 SLRPs, play important roles in TMJ assembly, proliferation and inflammation. Degenerative change in the TMJ disc gives rise to the process of internal derangement (ID). In this study, we immunohistochemically examined the expression of lumican and fibromodulin in nine human TMJ specimens and examined the gene expression of both proteoglycans in cultured human TMJ disc cells under interleukin-1 beta (IL-1 β)-stimulated conditions. An articular disc cell line was established by collagenase treatment of a TMJ disc. The subcultured cells were then incubated for 1, 3, 6, 12, 24 or 48 h under both normal and IL-1 β (1 ng/mL) conditions. The gene expression of lumican and fibromodulin was examined using the reverse transcription-polymerase chain reaction (RT-PCR) and real-time RT-PCR. We demonstrated that the expression of lumican significantly differs from that of fibromodulin in the deformed disc and that IL-1 β induces a significant increase in lumican mRNA, but not in fibromodulin mRNA, after 24∼48 h culture compared to cells cultured in the absence of IL-1 β (P<0.05). These results indicate that lumican and fibromodulin display different behaviors and that lumican may promote regeneration of the TMJ after degeneration and deformation induced by IL-1 β.