Impact of concurrent antibody-drug conjugates and radiotherapy on symptomatic radiation necrosis in breast cancer patients with brain metastases: a multicenter retrospective study.

AIM: We aimed to investigate the impact of concurrent antibody-drug conjugates (ADC) and radiotherapy on symptomatic radiation necrosis (SRN) in breast cancer patients with brain metastases (BM). METHODS: This multicenter retrospective study uses four institutional data. Eligibility criteria were histologically proven breast cancer, diagnosed BM with gadolinium-enhanced MRI, a Karnofsky performance status of 60 or higher, and radiotherapy for all BM lesions between 2017 and 2022. Patients with leptomeningeal dissemination were excluded. Concurrent ADC was defined as using ADC within four weeks before or after radiotherapy. The cumulative incidence of SRN until December 2023 with death as a competing event was compared between the groups with and without concurrent ADC. Multivariable analysis was performed using the Fine-Gray model. RESULTS: Among the 168 patients enrolled, 48 (29%) received ADC, and 19 (11%) had concurrent ADC. Of all, 36% were HER2-positive, 62% had symptomatic BM, and 33% had previous BM radiation histories. In a median follow-up of 31 months, 18 SRNs (11%) were registered (11 in grade 2 and 7 in grade 3). The groups with and without concurrent ADC had 5 SRNs in 19 patients and 13 SRNs in 149, and the two-year cumulative incidence of SRN was 27% vs. 7% (P = 0.014). Concurrent ADC was associated with a higher risk of SRN on multivariable analysis (subdistribution hazard ratio, 3.0 [95% confidence interval: 1.1-8.3], P = 0.030). CONCLUSIONS: This study suggests that concurrent ADC and radiotherapy are associated with a higher risk of SRN in HER2-positive breast cancer patients.

[Analysis of Pemetrexed Monotherapy in Advanced Non-Small Cell Lung Cancer Patients with Impaired Renal Function].

Toxicity and efficacy of pemetrexed monotherapy in advanced non-small-cell lung cancer patients with impaired renal function treated between May 2009 and May 2012 at Gifu University Hospital were retrospectively analyzed. A total of 10 and 17 patients had a creatinine clearance rate (Ccr) of <45 mL/min and ≥45 mL/min, respectively. The median age was higher in the Ccr<45 mL/min group (78.9 years) than in the ≥45 mL/min group (65.2 years). The rate of neutropenia above Grade 3 was 30% in the Ccr<45 mL/min group and 6% in the ≥45 mL/min group. Therefore, reducing the dose of pemetrexed should be considered in patients with impaired renal function. Non-hematologic toxicities were not correlated with the renal function. There was no treatment-related death, and most of the toxicities were mild and tolerable. Stable disease was observed in 6 patients (60%) in the Ccr<45 mL/min group, and in 12 patients (70%) in the Ccr≥45 mL/min group, although some patients in both groups showed neither complete nor partial responses. The disease control rate and median progression-free survival time were 60% and 2.8 months in the Ccr<45 mL/min group, and 70% and 2.9 months in the Ccr≥45 mL/min group, respectively. Thus, in this analysis, treatment with pemetrexed resulted in clinically equivalent efficacy in advanced non-small-cell lung cancer patients regardless of the state of renal function.

Liver function and image evaluation after radiotherapy for liver metastases after resection of sigmoid colon cancer a case report.

INTRODUCTION: Radiotherapy is a treatment option in the management of patients with metastatic liver disease. The aim in this case was to evaluate radiation-induced dysfunctional liver lesions using 99mTc-GSA-SPECT, Gd-EOB-DTPA-enhanced MRI, and radiation dose distribution in a patient after radiation therapy. PRESENTATION OF CASE: After sigmoid colon resection, three liver metastases were treated with radiotherapy at the same time. Liver function after radiotherapy was determined to be A according to the Child-Turcott-Pugh classification. 99mTc-GSA-SPECT showed a wider reduction in uptake than Gd-EOB-DTPA MRI at all three sites. HH15 showed decreased liver function. DISCUSSION: In the 99mTc-GSA-SPECT and Gd-EOB-DTPA MRI hepatocyte phases, residual signals of normal hepatocytes were observed despite irradiation at three sites. Additional treatment could be considered for the two recurrent lesions because there was no deterioration of liver function in post-irradiation imaging findings and blood sampling. CONCLUSION: 99mTc-GSA-SPECT and EOB-MRI showed characteristic findings for evaluation of liver function after radiotherapy for multiple liver metastases, suggesting the need for both imaging evaluations. It is now possible to choose whether to perform local additional treatment (additional radiation, RFA) or other chemotherapy for liver metastases after recurrence.

Future Perspective for ALK-Positive Anaplastic Large Cell Lymphoma with Initial Central Nervous System (CNS) Involvement: Could Next-Generation ALK Inhibitors Replace Brain Radiotherapy for the Prevention of Further CNS Relapse?

Central nervous system (CNS) involvement in anaplastic large cell lymphoma (ALCL) at diagnosis is rare and leads to poor prognosis with the use of the standard ALCL99 protocol alone. CNS-directed intensive chemotherapy, such as an increased dose of intravenous MTX, increased dose of dexamethasone, intensified intrathecal therapy, and high-dose cytarabine, followed by cranial irradiation, has been shown to improve survival in this population. In this paper, the authors describe a 14-year-old male with an intracranial ALCL mass at onset who received CNS-directed chemotherapy followed by 23.4 Gy of whole-brain irradiation. After the first systemic relapse, the CNS-penetrating ALK inhibitor, alectinib, was applied; it has successfully maintained remission for 18 months without any adverse events. CNS-penetrating ALK inhibitor therapy might prevent CNS relapse in pediatric ALK-positive ALCL. Next-generation ALK inhibitors could be introduced as a promising treatment option, even for primary ALCL with CNS involvement, which could lead to the omission of cranial irradiation and avoid radiation-induced sequalae. Further evidence of CNS-penetrating ALK inhibitor combined therapy for primary ALK-positive ALCL is warranted to reduce radiation-induced sequalae in future treatments.

Tetomilast attenuates elastase-induced pulmonary emphysema through inhibition of oxidative stress in rabbits.

Tetomilast was originally identified as a potent inhibitor of superoxide production in human neutrophils, and is of interest because it may relieve oxidative stress related to chronic obstructive pulmonary disease (COPD). Our objective was to determine whether tetomilast effectively protects against the development of porcine pancreatic elastase (PPE)-induced emphysema in rabbits. Rabbits were divided into three groups (sham n=19, PPE n=19, PPE/Tetomilast n=18). The rabbits were once daily orally administered vehicle solution or tetomilast 5 d/week for 4 weeks before the PPE instillation. We compared pulmonary function, inflammatory cell infiltration, oxidative stress, and the incidences of apoptosis among the three groups. Tetomilast suppressed PPE-induced increases in the incidence of apoptosis and the production of 8-hydroxy-deoxyguanosine (8-OHdG) in lung tissues. PPE-instilled rabbits treated with tetomilast showed significantly less mean linear intercept and significantly better pulmonary function than rabbits administered PPE alone. Tetomilast may inhibit the development of emphysema by attenuating pulmonary inflammation and apoptosis caused by PPE-induced oxidative stress.

Correlations between intraplan and postplan parameters in I-125 permanent prostate brachytherapy using loose seeds or linked seeds.

The purpose of this study was to determine the most appropriate seed arrangement by comparing two different methods (linked seeds and loose seeds). A total of sixty-one patients (28 linked seed brachytherapy cases and 33 loose seed brachytherapy cases) with clinically localized prostate cancer were treated with I-125 permanent prostate brachytherapy. Modified peripheral loading was the method used for seed placement. The parameters evaluated were as follows: prostate D90, V100, and V150; urethral D90, D10, and D5; and rectal V100 (RV100) and D2 (RD2). Coefficient parameters (r and r2) were assessed by regression analysis. Prostate V150, urethral D90, urethral D10, urethral D5, and RD2 showed significant correlations between both methods in all patients. Urethral D90, urethral D10, urethral D5, and RD2 showed significant correlations in patients who received linked seed brachytherapy. Prostate V150, urethral D90, urethral D10, urethral D5, RV100, and RD2 showed significant correlations in patients who received loose seed brachytherapy. Urethral D90, urethral D10, urethral D5, and RD2 showed significant correlations in the linked seed and loose seed brachytherapy analyses. In contrast, prostate D90 and prostate V100 showed no correlation. Parameters of normal organ damage showed good correlations between intraplan and postplan parameters. These parameters may be useful to determine normal organ damage during guided brachytherapy with two different methods (linked seeds and loose seeds).

Efficacy of cisplatin plus vinorelbine adjuvant chemotherapy with split-dose administration of cisplatin after complete resection of stage II-IIIA non-small cell lung cancer.

Although co-administration of cisplatin (CDDP) and vinorelbine (VNR) has been established as a standard of care adjuvant chemotherapy for non-small cell lung cancer (NSCLC), there is a lack of clinical data on its safety and efficacy in Japanese patients receiving split-dose administration of CDDP. The present study analyzed patients who received CDDP + VNR with split-dose administration of CDDP after undergoing complete resection of NSCLC. Patients received four courses of CDDP (40 mg/m2) and VNR (25 mg/m2) on days 1 and 8, every 3 weeks. There were 27 male and 13 female patients; the mean age was 65 years (range 38-78 years), the postoperative disease staging distribution was IIA/IIB/IIIA: 14/8/18 patients, and histological distribution was adenocarcinoma/squamous cell carcinoma/others: 24/12/4 patients, respectively. Of the 40 patients, 28 (70%) completed the four courses of treatment. The mean total dose administered was 279 mg/m2 CDDP (87.2%) and 172 mg/m2 VNR (86%). The major adverse events included Grade (G) 3 or higher neutropenia (80%), G3 phlebitis (5%) and vomiting (2.5%). There was no G2 or higher serum creatinine level elevation, G3 or higher anorexia and nausea, or any treatment-related deaths. The overall completion rate of four courses was 70 and 62.5% for patients aged 70 years and older, whereas the overall percentage of patients that could complete three or more courses was 85 and 87.5% for patients aged 70 years and older. The relapse-free survival rate was 60% at 3 years and 57.5% at 5 years. Overall survival rate was 80% at 3 years and 60% at 5 years. The present study demonstrated the sufficient tolerability, safety and efficacy of combined CDDP + VNR adjuvant chemotherapy with split-dose administration of CDDP, with a low risk of gastrointestinal toxicities or nephrotoxicity.

[A trial of 89Sr bremsstrahlung SPECT].

OBJECTIVE: 89Sr bremsstrahlung SPECT imaging has been evaluated for detecting the more detailed whole body 89Sr distribution. METHODS: 89Sr bremsstrahlung whole body planar and merged SPECT images were acquired by using two detectors type SPECT system. Energy window A (100 keV +/- 50%) for planar imaging, and energy window A plus adjacent energy window B (300 keV +/- 50%) for SPECT imaging were set on the continuous spectrum. Those images were compared with 99mTc-H-MDP whole body planar and merged SPECT images. To verify the accumulation obtained by bremsstrahlung whole body planar and merged SPECT image, we made original phantom based on the counts of clinical study imaging. RESULTS: On 89Sr bremsstrahlung merged SPECT image, focal accumulations were recognized in the parts of 99mTc-H-MDP merged SPECT accumulation. Focal accumulations were much clearer on 89Sr bremsstrahlung merged SPECT imaging than those of whole body planar image of 89Sr bremsstrahlung. In phantom study, counts of each concentration linearly increase as acquisition time and number of rotation increase on planar and SPECT images. CONCLUSIONS: 89Sr bremsstrahlung merged SPECT imaging would be useful for detecting the more detailed whole body 89Sr distribution.

Evaluation of clinical pharmacist interventions for adverse events in hospitalized patients with thoracic cancer receiving cancer chemotherapy.

Due to the increasing complexity of cancer chemotherapy and its associated supportive care, the role of clinical pharmacists in cancer chemotherapy is becoming increasingly more important. The present study evaluated the clinical interventions of a single pharmacist on the adverse events in hospitalized patients with thoracic cancer receiving cancer chemotherapy. A single-center, retrospective study was conducted at the 614-bed, tertiary care Gifu University Hospital. Hospitalized patients with thoracic cancer who received cancer chemotherapy in the respiratory medicine ward between April 2013 and May 2014 were enrolled. One of the two clinical pharmacists in charge was based in the respiratory medicine ward and implemented pharmaceutical care for the patients, including management of adverse events. Patient data were recorded in the electronic medical chart and retrospectively analyzed. A total of 445 patients with thoracic cancer received cancer chemotherapy in the respiratory medicine ward. A total of 152 interventions (101 patients) were performed by the clinical pharmacist prior to the administration of cancer chemotherapy, half of which comprised the addition of drugs to prevent adverse events. A total of 190 patients (39.4%) experienced grade ≥2 non-hematological or grade ≥3 hematological adverse events associated with cancer chemotherapy, and 223 medical interventions for relief of adverse events lowered the incidence of grade ≥2 non-hematological or grade ≥3 hematological adverse events to 17.8%. Of these, 45.3 and 7.5% of medical interventions for non-hematological and hematological adverse events, respectively, were implemented based on the pharmacist's recommendations. These findings revealed the marked contribution of a single clinical pharmacist in the respiratory medicine ward to the prevention and relief of adverse events in hospitalized patients with thoracic cancer receiving cancer chemotherapy.

Predictors of Secondary Bladder Cancer in Patients with Prostate Cancer Treated with Brachytherapy: A Single-institution Study of a Japanese Cohort.

PURPOSE: The incidence of secondary bladder cancer after treatment for localized prostate cancer (PCa) remains unclear. In this study, PCa cases treated with brachytherapy (BT) were evaluated to assess the incidence of a second malignancy of bladder cancer in a Japanese cohort. MATERIALS AND METHODS: Overall, 969 patients treated with BT at our hospital between July 2006 and January 2019 were included in the study cohort. The incidence and predictors of secondary bladder cancer were also assessed. RESULTS: The incidence of secondary bladder cancer was 1.5% (n = 14). Of the seven factors (age, pretreatment PSA, Gleason score, cTNM stage, prostate volume, total activity, and combined external beam), prostate volume and total activity showed significant differences between the cohorts with and without secondary bladder cancer (P = .03 and P = .001, respectively). Upon comparison of the seven parameters for the 969 patients treated with BT, we found that only the total activity factor was affected by the incidence of secondary bladder cancer in the multivariate analysis (P = .007). CONCLUSION: The incidence of secondary bladder cancer was evaluated after BT for PCa. Total activity was associated with the incidence of secondary bladder cancer in Japanese patients who received BT.

Massive hematuria from the bilateral upper urinary tract in a patient treated for advanced lung cancer with gefitinib.

We report a case of gefitinib-induced bilateral upper urinary tract bleeding in an 82-year-old woman administered the drug daily for advanced non-small cell adenocarcinoma of the lung (T4N3M0). Hematuria is an uncommon adverse effect of gefitinib, and in most cases, the bleeding site is unknown. On the 44th day of oral gefitinib administration, the patient noted asymptomatic macroscopic bloody urine. Cystoscopy revealed bleeding from the bilateral ureteric orifices without hemorrhagic inflammation of the bladder. One week later, she was admitted complaining of severe abdominal pain, and her condition was found to be complicated by liver damage and renal dysfunction. We stopped gefitinib administration and started hydration and diuresis. Renal function and urine output soon recovered, and at the request of the patient, we restarted gefitinib, administering it every other day, which was sufficient to maintain antitumor activity and stabilize the disease. On the 41st day after restarting gefitinib, hematuria and proteinuria reappeared. We therefore stopped the gefitinib, and the patient was followed with supportive care. The patient's autopsy findings denied organic urologic diseases. Instead, the reproducibility of the hematuria from the upper urinary system strongly suggests an unexpected gefitinib-related adverse effect.

Polymerase chain reaction positivity of Pneumocystis jirovecii during primary lung cancer treatment.

OBJECTIVE: When treating lung cancer, pneumocystic pneumonia is a life-threatening complication seen during chemotherapy. Polymerase chain reaction is used to detect its cause, Pneumocystis jirovecii, but polymerase chain reaction positives without pneumocystic pneumonia are sometimes seen. The purpose of this study was to assess the frequency of pneumocystic pneumonia during cancer treatment. METHODS: Fifty induced sputum specimens and 4 bronchoalveolar lavage specimens collected from 50 patients with acute respiratory symptoms during anticancer therapy were retrospectively studied after classifying the patients into lung cancer (n = 29) and solid tumor (n = 21) groups. All of the patients in both groups had an interstitial shadow suspected of being pneumocystic pneumonia, and all had polymerase chain reaction tests. RESULTS: Eleven of the 54 specimens were polymerase chain reaction positive, and 1 patient was clinically diagnosed with pneumocystic pneumonia. The incidence of polymerase chain reaction positivity in the lung cancer group was significantly higher than in the solid tumor group (31 vs. 5%; P = 0.03), and the incidence of subclinical pneumocystic pneumonia (29 vs. 5%; P = 0.059) also tended to be higher in that group. There were no significant biochemical differences between the two groups, irrespective of the polymerase chain reaction results. Among polymerase chain reaction-positive patients in the lung cancer group, the cumulative dose of corticosteroid administration tended to be higher than among the polymerase chain reaction-negative patients (P = 0.09). Following the polymerase chain reaction tests, nearly all polymerase chain reaction-positive patients without pneumocystic pneumonia received antipneumocystic agents, and none developed pneumocystic pneumonia. CONCLUSIONS: Our findings suggest polymerase chain reaction positivity for P. jirovecii will be detected in a fraction of lung cancer patients. Although it is difficult to predict the need for administration of pneumocystic pneumonia treatment to subclinical pneumocystic pneumonia based on polymerase chain reaction and biochemical results, polymerase chain reaction-positive patients should be followed-up with antipneumocystic agents to ensure they are not at an early stage of pneumocystic pneumonia.

Use of multidetector row CT to evaluate the need for bronchial arterial embolization in hemoptysis patients.

BACKGROUND: Bronchial artery (BA) embolization (BAE) is recommended as a minimally invasive therapy for hemoptysis, though some patients recover after only conservative treatment. OBJECTIVES: The purpose of our study was to assess the characteristics of BAs using multidetector row computed tomography (MDCT) and identify BAs requiring BAE without BA angiography (BAG). METHODS: We retrospectively studied 41 patients and classified the visualized BAs into groups based on their BAE and bleeding statuses. Patients presenting with massive hemoptysis requiring emergency BAE were excluded. Patients presenting with persistent hemoptysis that was resistant to conservative treatment received BAE. Radiologists measured BA diameters at the ostium, bronchial bifurcation and pulmonary hilum, and also evaluated the degree of vascularization. RESULTS: MDCT enabled visualization of 102 ostia and 96 traceable BAs. Among the participating patients, 13 had at least one ectopic origin. We obtained a good correlation between BAG and MDCT diameters (r = 0.709, p < 0.001). The diameters of BAs responsible for bleeding and receiving BAE were apparently larger in each measured segment than those that were not (p < 0.05). Moreover, the diameters of arteries receiving BAE remained largely unchanged from the origin to the hilum and through the mediastinum. BAs with low MDCT scores were significantly less likely to required BAE than those with high scores (p = 0.004), and in multiple logistic regression analysis, ostium diameter and bleeding status were independent predictive factors for BAE. CONCLUSIONS: Evaluation of BAs on MDCT could be useful for identifying the anatomical characteristics of bleeding-related BAs and determining whether BAE is indicated or whether conservative treatment is sufficient.

Effect of intermittent systemic corticosteroid on bone metabolism in bronchial asthma patients.

The purpose of this study was to assess the effect on bone mineral density (BMD) of systemic corticosteroid (SCS) intermittently administered for rescue from asthmatic exacerbation. Through digital image processing and calculation of four other indices, BMD was compared in groups of asthmatic patients receiving inhaled corticosteroid (ICS) alone or ICS plus intermittent SCS. We defined SCS as intermittent administration of the equivalent of 1 mg/day prednisolone in the management of asthma exacerbations during the previous 1 year. Serum NTX, a bone resorption marker, was significantly higher (p = 0.02) in the SCS group than the ICS group. SCS had no effect on BMD, although the frequency of patients at "high-risk" for osteoporosis according to the Female Osteoporosis Self-assessment Tool for Asia (FOSTA) tended to be higher in the SCS group (35%) than in the ICS (28%) or control (10%) group. Because patients in the ICS group already had impaired respiratory function due to repeated asthma exacerbations, it was difficult to determine whether it was asthma itself or SCS that is the risk factor for osteoporosis. In addition, the response of biochemical markers of bone turnover to intermittent SCS remains unclear and likely differs from that elicited by high-dose, short-term, or continuous SCS. That said, relatively low-dose intermittent administration of SCS raised levels of bone resorption markers, which likely reflects altered bone metabolism. Taken together, these findings suggest that, without consideration of its effects on bone, SCS administration should be avoided.

[Sarcoidosis-lymphoma syndrome with vertebral bone destruction].

We report a rare case of sarcoidosis-lymphoma syndrome with vertebral bone destruction. A 63-year-old woman was previously diagnosed as sarcoidosis by supraclavicular lymph node biopsy, and came to our hospital complaining of back pain. Both serum angiotensin-converting enzyme and lysozyme level had been continuously elevated. Magnetic resonance imaging revealed lumbar vertebral bone destruction. Histopathologic examination of lumbar vertebral tumor obtained by CT-guided biopsy revealed non-caseating epithelioid granuloma with CD 68 (+), AE1/AE3 (-), and no malignant cells. She was admitted to our hospital again for dyspnea and pancytopenia. We diagnosed active sarcoidosis and administered oral 30mg prednisolone daily. One month later, prednisolone became ineffective. Flow cytometry of tumor cells obtained from the gastric ulcer floor showed CD 5 (+), CD 20 (+), K chain monoclonality and we diagnosed B-cell non Hodgkin's lymphoma. She was treated by eight cycles of CHOP plus rituximab chemotherapy and achieved complete response. FDG uptake of the entire body decreased, whereas MRI revealed residual mass in the vertebrae. Sarcoidosis had been diagnosed for two and half years before lymphoma developed. Bone destruction is very rare and sarcoidosis is rarely the cause. This is quite an unusual case presenting histologically proved epithelioid granuloma and vertebral destruction in sarcoidosis-lymphoma syndrome.

Immune thrombocytopenia induced by nivolumab in a patient with non-small cell lung cancer.

Antibodies targeting the receptor programmed death 1 on T cells have been approved for the treatment of lung cancer. Immune checkpoint inhibitors (ICIs) induce various immune-related adverse events. Life-threatening hematotoxicity can be provoked by ICI therapy. Although ICI-related endocrinopathy and interstitial lung disease have been well documented, hematotoxicity requiring intensive treatment is relatively rare. We describe a case of nivolumab induced thrombocytopenia after transient mild fever. A 77-year-old man with non-small cell lung cancer was administered nivolumab (240 mg/body, every 2 weeks) as second line therapy. On the day 2 after the first nivolumab infusion, he had a fever and his C-reactive protein level was elevated. Thoracic computed tomography revealed no interstitial lung disease or pneumonia. The fever resolved on day 9 and was not seen thereafter. On day 15 after the first nivolumab infusion, severe thrombocytopenia suddenly emerged. A bone marrow examination revealed no dysplasia or invasion. Based on the presence of high platelet-associated IgG titer, normal bone marrow plasticity and a lack of effectiveness of platelet infusion, we diagnosed nivolumab-induced immune thrombocytopenia. Daily administration of 60 mg of prednisolone restored the patient's platelet count and platelet-associated IgG. We also found that there was significant shrinkage of the primary lesion and that stable disease was achieved. One must be aware of this relatively rare side effect and the unusual clinical findings that could be associated with immunoreaction.

The SAR studies of novel CB2 selective agonists, benzimidazolone derivatives.

Benzimidazolone derivatives were discovered as novel CB2 selective agonists. Structure Activity Relationship (SAR) studies around them were examined to improve metabolic stability. Compound 39 exhibited excellent metabolic stability in human liver microsomes (HLM) and significant attenuation of the chronic colonic allodynia in the TNBS-treated rats by po administration.

Synthesis of benzamide derivatives as TRPV1 antagonists.

From hit compounds identified by high throughput screening (HTS), we have found compound 1 as a lead TRPV1 antagonist and confirmed its potential as a treatment for pain. Compound 1 has led to potent TRPV1 antagonistic benzamide derivatives ((+/-)-2: human IC(50)=23 nM, (+/-)-3: human IC(50)=14 nM in the capsaicin-induced calcium influx assay) containing indole and naphthyl moieties, obtained by elaboration of the tryptamine scaffold or via bioisosteric replacements.

In vivo imaging of microglial activation using a peripheral benzodiazepine receptor ligand: [11C]PK-11195 and animal PET following ethanol injury in rat striatum.

OBJECTIVE: To investigate whether [(11)C]PK-11195, a specific peripheral benzodiazepine receptors (PBRs) ligand for positron emission tomography (PET), can show activated microglia in a rat brain injury model. METHODS: On day 1, ethanol was injected into the rat's right striatum (ST) using a stereotaxic operative procedure. On day 3, head magnetic resonance imaging (MRI) scans for surgically treated rats were performed to evaluate ethanol injury morphologically. On day 4, dynamic PET scans (17 injured rats and 7 non-injured controls) were performed for 60 min with an animal PET scanner under chloral hydrate anesthesia following a bolus injection of [(11)C]PK-11195 through tail vein. Because PBRs are present throughout the brain, there is no suitable receptor-free reference region. The reference tissue model may not be applicable because of low target to background ratio for low affinity of [(11)C]PK-11195 to PBRs. We evaluated the PBRs binding with regions of interest (ROIs)-based approach to estimate total distribution volume (V). We used an integral from 0 min to 60 min (V (60)) as an estimate of V. On the coronal PET image, ROIs were placed on bilateral ST. Differences in right/left ST V (60) ratios between lesioned and unlesioned control rats were compared using unpaired t tests. Immunohistochemical staining was performed for confirming the presence of activated microglia following decapitation on the PET experiment day. RESULTS: The right/left ST V (60) ratios in lesioned rats (1.07 +/- 0.08) were significantly higher than those in unlesioned control rats (1.00 +/- 0.06, P < 0.05). On immunohistochemical staining, activated microglia were exclusively observed in the injured right ST but not in the noninjured left ST of the injury rats and the bilateral ST of the non-injured control rats. CONCLUSIONS: These results suggest that [(11)C]PK-11195 PET imaging would be a useful tool for evaluating microglial activation in a rat brain injury model.

Stereoselective synthesis of a novel 2-aza-7-oxabicyclo[3.3.0]octane as neurokinin-1 receptor antagonist.

A novel neurokinin-1 receptor antagonist, (+/-)-(1R( *),3S( *),4S( *),5S( *))-4-[(N-(2-methoxy-5-trifluoromethoxybenzyl)amino]-3-phenyl-2-aza-7-oxabicyclo[3.3.0]octane (1), was synthesized stereoselectively using Padwa's intramolecular 1,3-dipolar cycloaddition methodology as the key step. Compound (+/-)-1 showed high affinity for the NK-1 receptors in human IM-9 cells with an IC(50) value of 0.22 nM. This new structural scaffold demonstrated significant in vivo antagonistic activity in the guinea pig ureter capsaicin-induced plasma extravasation model with an ED(50) value of 1-10mg/kg, po.