Sleep spindles in adolescents with major depressive disorder

Sleep spindle differences in adolescents with major depressive disorder (MDD) compared to healthy adolescents is an ongoing debate. Results mostly indicate decreased sleep spindle activity in adolescents with MDD. Given that sleep spindles predominate NREM and that acutely delaying the sleep period via a "sleep delay challenge" (SDC) increases non-rapid eye movement (NREM) sleep duration, it may be possible to increase spindle density in adolescents with MDD, which may provide a therapeutic benefit to depression symptoms. Here, we examined the impact of a SDC on spindle density and depression symptomology in adolescents with MDD (n = 66) and healthy controls (n = 62) tested across three nights: adaptation, normal sleep, and a SDC night which delayed bedtime by three hours. The results showed that; (1) there was no difference in spindle density between groups on the normal sleep night, (2) following the SDC, both males and females with MDD had a decrease in the frequency of slow spindles, while only females with MDD had an increase in the frequency of fast spindles, (3) acute SDC reduced depression symptoms in both groups, and (4) light sleep on the normal sleep night and slow spindle frequency at SDC predicted an 8 % improvement in depression symptoms, regardless of sex or MDD diagnosis. Taken together, these results suggest that; (a) spindles may be a useful biological marker of depression symptomatology regardless of clinical MDD diagnosis, and (b) that acute SDC may help alleviate depression symptoms in adolescents with MDD.

Neoantigen-specific CD4+ T cells in human melanoma have diverse differentiation states and correlate with CD8+ T cell, macrophage, and B cell function

CD4⁺ T cells that recognize tumor antigens are required for immune checkpoint inhibitor efficacy in murine models, but their contributions in human cancer are unclear. We used single-cell RNA sequencing and T cell receptor sequences to identify signatures and functional correlates of tumor-specific CD4⁺ T cells infiltrating human melanoma. Conventional CD4⁺ T cells that recognize tumor neoantigens express CXCL13 and are subdivided into clusters expressing memory and T follicular helper markers, and those expressing cytolytic markers, inhibitory receptors, and IFN-γ. The frequency of CXCL13⁺ CD4⁺ T cells in the tumor correlated with the transcriptional states of CD8⁺ T cells and macrophages, maturation of B cells, and patient survival. Similar correlations were observed in a breast cancer cohort. These results identify phenotypes and functional correlates of tumor-specific CD4⁺ T cells in melanoma and suggest the possibility of using such cells to modify the tumor microenvironment.

The immune impact of PI3K-AKT pathway inhibition in colorectal cancer

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Background: Our prior work has shown that PI3K-altered colorectal cancer (CRC), with PIK3CA mutation or PTEN loss, has increased expression of key immune checkpoints (including PD-L1) resulting in immune evasion, despite increased immune engagement. Here, we investigated the impact of PI3K-AKT inhibition on the immune repertoire of CRC. Methods: Multiplex immunofluorescence was performed using two Vectra panels [1: AE1/AE3, CD3, CD8, PD-1, PD-L1, CD68; and 2: AE1/AE3, CD3, CD8, Granzyme B (GzB), CD45RO, FoxP3] on paired biopsies (baseline and cycle 1 day 15) from 6 patients with PI3K-altered metastatic CRC (mCRC) treated with AKT inhibitor, MK2206 (200 mg oral weekly), on a phase 2 clinical trial. Separately, one million CT26 CRC cells were implanted in BALB/C-e mice. After 48 hours, 10 mice/group were randomized for treatment with pan-PI3K inhibitor copanlisib (C, 10 mg/Kg IV 2x/week), anti-PD-1 (P, 200 µg IP 2x/week), copanlisib + anti-PD-1 (C+P), or control (Ct), for 21 days. Mouse tumors were stained with 6-plex immunohistochemistry (CD3, CD8, PD-L1, Ki67, GzB, AE1/AE3). Data were analyzed using related-samples Wilcoxon Signed-Rank test, Mann-Whitney U test, Kruskal-Wallis test, and Student’s t-test, as appropriate. Results: In PI3K-altered mCRC patients, AKT inhibition resulted in a trend towards increased median densities of intratumoral CD8+ T cells (0.8 vs 4.8 density/mm2, P = 0.14) and memory T cells (0 vs 10.3, P = 0.07), and decreased density of macrophages (12.4 vs 0, P = 0.07). No antigen experienced T cells were seen and activated CD8+ T cells were present in 1 patient only. In CT26 mice, PI3K and PD-1 co-inhibition resulted in the smallest mean tumor volumes (C+P 12% of Ct vs C 40% and P 42% of Ct, P < 0.05 for both), and the highest median % of intratumoral CD8+Ki67+ T cells as compared to all other treatment arms (C+P 1.6% vs C 0.5%, P 0.4%, Ct 0.6%, P < 0.05 for each pairwise comparison). C+P also increased the % of total CD3+ and CD8+ cells as compared to Ct and C (P < 0.05 for all). C alone did not increase immune infiltration in this non-PI3K activated model. Conclusions: PI3K-AKT pathway inhibition has the potential to improve effector T cell infiltration in PI3K-altered CRC. PI3K inhibitor synergizes with anti-PD-1 to improve treatment efficacy and CD8+ T cell proliferation. The mechanisms behind this immune repertoire shift are yet to be elucidated, such as via cytokine modulation. Therapeutic approaches to activate the proliferating CD8+ cells would be useful, and may require PI3Kα/β specific inhibitors to allow early T cell activation through PI3Kδ/γ isoforms.

Structural defects of monolayer wet particles during melting under vertical vibration

The evolution of structural defects during phase transition is of great significance to the understanding of the mechanism of solid-liquid transition. However, the current research on topological defects still uses the pair-correlation function and the orientational order correlation function, so it is difficult to quantify the detailed changes of structural defects locally. In this paper, the local volume fraction is proposed as a key parameter to accurately quantify the variation of structural defects. The experimental results indicate that the evolution of structural defects in the particle system is caused by the decrease of local volume fraction, so the critical value of phase transition could be determined by the minimum local volume fraction ϕ_{min}. Furthermore, according to the evolution law of structural defects, it can be deduced that the phase transition is continuous, which is consistent with the Kosterlitz-Thouless-Halperin-Nelson-Young theory. Therefore, the quantitative analysis of structural defects by using local volume fraction can help make the mechanism of solid-liquid phase transformation clearer.

Efficacy of Motivational Interviewing in Treating Co-occurring Psychosis and Substance Use Disorder: A Systematic Review and Meta-Analysis

Objective: A wealth of evidence has supported the efficacy of motivational interviewing (MI) in reducing substance use as well as other addictive behaviors. In view of the common co-occurrence of substance use disorder among individuals with schizophrenia spectrum disorders, there has been increased attention to applying MI in psychological interventions for individuals with co-occurring psychosis and substance use disorder. This review aims to synthesize the evidence on the efficacy of MI interventions (either as a stand-alone intervention or in combination with other psychological interventions) in reducing substance use and psychotic symptoms. Data Sources: MEDLINE, PsycINFO, EMBASE, CENTRAL, and CINAHL were searched using keywords related to "psychosis," "substance addiction," and "motivational interviewing" to identify studies published in English from 1984 to May 2021. Study Selection: Of 1,134 articles identified in the literature, we selected 17 studies for review: 5 studies examined stand-alone MI ("MI-pure"), and 13 studies assessed MI as a major treatment component ("MI-mixed"). Data Extraction: Demographics of participants, intervention characteristics, and outcome data were extracted by the first author and checked by the second author. Random-effects models were used for substance use and psychotic symptom outcomes. Results: MI-pure interventions did not significantly reduce severity of substance use (g = 0.06, P = .81) or psychotic symptoms (g's for 2 individual studies = 0.16, P = .54; and 0.01, P = .96). The effect of MI-mixed interventions on substance use decrease was statistically significant but small in size (g = 0.15, P = .048), whereas the effect on psychotic symptom improvement was not significant (g = 0.11, P = .22). Conclusions: With the caveat that only a small number of comparisons were available for the review on MI-pure interventions, the efficacy of MI in treating co-occurring psychosis and substance use disorder was heterogeneous and modest.

HIF-1α repairs degenerative chondrocyte glycolytic metabolism by the transcriptional regulation of Runx2

OBJECTIVE

HIF-1α and Runx2 expression usually increase in chondrocytes (CHs) during osteoarthritis (OA), which involves the changes in glycolytic metabolism. However, the molecular regulation of HIF-1α related to the CHs glycolytic metabolism is still unclear. In this study, we aimed to reveal the mediation of HIF-1α by Runx2 and its effect on the glycolytic metabolism of degenerative CHs.

PATIENTS AND METHODS

The expression of HIF-1α, Runx2, and the degenerative markers of CHs in both natural conditions from the OA patients and IL-1β treated in vitro model was analyzed by a Western blot or real-time polymerase chain reaction (RT-PCR). The glycolytic metabolism was determined by the intracellular glucose uptake and adenosine triphosphate (ATP) generation. Transfection of siRNA coding HIF-1α or Runx2 was used to clear the function between HIF-1α and Runx2 in the glycolytic metabolism of degenerated CHs caused by IL-1β. Chromatin immunoprecipitation (ChIP) and Luciferase reporter gene assay were used to verify the Runx2 protein binds to the promoter of HIF-1α and promote its expression.

RESULTS

HIF-1α and Runx2 were increased, and glucose uptake and ATP generation were decreased in the degenerative CHs from both OA and IL-1β conditions. Under the stimulation of IL-1β, Runx2 silencing rejected the upregulation of HIF-1α and further aggravated the glycolytic metabolism. When HIF-1α was silenced, the glycolytic metabolism of CHs was also suppressed. Besides, Runx2 protein could regulate HIF-1α expression in the transcriptional level by binding to its promoter.

CONCLUSIONS

OHIF-1α plays a role in the self-repair of the glycolytic metabolism of degenerative CHs via the transcriptional regulation of Runx2.

Abstract 1660: Preliminary safety tolerability & efficacy results of KN046 (an anti-PD-L1/CTLA-4 bispecific antibody) in combination with Nab-paclitaxel in patients with metastatic triple-negative breast cancer (mTNBC)

Background: Triple-negative breast cancer (TNBC) has the poorest outcome when compared to other subtypes of invasive breast cancer. IMpassion130 and Keynote-355 studies demonstrated improved clinical outcome when anti-PD-(L)-1 agents were combined with first line chemotherapies in PD-L1 positive TNBC. KN046 is a novel bispecific antibody that blocks PD-L1 and CTLA-4 pathways. Here we reported the interim results from an ongoing phase II study for KN046 in combination with nab-paclitaxel in pts with mTNBC.

Methods: This study enrolled pts with treatment-naïve locally advanced inoperable or metastatic TNBC. Eligible pts received nab-paclitaxel plus KN046 at two dose levels (DL1: KN046 3 mg/kg Q2W or DL2: KN046 5 mg/kg Q2W). Tumor response was evaluated Q8W per RECIST 1.1. PD-L1 expression was measured using SP142 assay.

Results: As of Oct. 29, 2020, 27 pts were enrolled into DL1 (n=16) and DL2 (n=11). 12 pts remained on the study and 15 pts discontinued treatment due to disease progression (n=8), death (n=1), adverse events (n=3) and other reasons (n=3). Patients tolerated well to KN046 plus nab-paclitaxel. No KN046 treatment related adverse event (TRAE) leading to death. TRAEs occurred in 27 (100%) pts, 13 (48.1%) were grade 3 or above. 11 (40.7%) pts experienced immune related adverse events (irAEs), including 2 patients experienced one grade 3 immune-mediated hepatic disorder and one grade 3 rash. The most common (≥ 20%) TRAE were AST increased (48%), ALT increased (48%), pyrexia (33%), neutrophil count decreased (30%), anaemia (26%), rash (26%) and white blood cell count decreased (26%). The most common (≥ 15%) grade 3 or above TRAEs were neutrophil count decreased (26%), white blood cell count decreased (22%) and AST increased (15%). Median PFS was 7.33 (4.04, NE) months and 12-month PFS rate was 38.3% (95% CI 19.7~74.6%). Median OS was not reached and 12-months OS rate was 80% (95% CI 61.4~100%). Among pts with PD-L1 positive (IC PD-L1≥1%) or PD-L1 status unknown tumors (exclude PD-L1 &lt; 1%), Median PFS was 7.36 (95% CI 7.36, NE) months and 12-month PFS rate was 49.4% (95% CI 20.6~100%). 12-month OS rate was 90.9% (95% CI 75.1~100%).

Conclusions: KN046 combined with nab-paclitaxel is well tolerated and has shown favorable clinical efficacy in PD-L1 positive TNBC. Preliminary overall survival data is encouraging. Clinical trial information: NCT03872791

Citation Format: Binghe Xu, Qiao Li, Qingyuan Zhang, Yue Zhang, Quchang Ouyang, Yang Zhang, Qiang Liu, Tao Sun, June Xu, Jing Yang, Yue Yang, Xin Luo, Paul Kong, Ting Xu. Preliminary safety tolerability & efficacy results of KN046 (an anti-PD-L1/CTLA-4 bispecific antibody) in combination with Nab-paclitaxel in patients with metastatic triple-negative breast cancer (mTNBC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1660.

A phase 2, open-label, multicenter study to evaluate the efficacy, safety, and tolerability of KN046 in combination with chemotherapy in subjects with advanced non-small cell lung cancer

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Background: Dual blockade of PD-1 and CTLA-4 has shown improved overall survival (OS) in combination with a short course of chemotherapy. KN046 is a novel bispecific antibody that blocks both PD-L1 interaction with PD-1/CD80 and CTLA-4 interaction with CD80/CD86. We hypothesized that KN046 could be combined with a full course of chemotherapy and build more durable clinical benefit. Methods: This study enrolled systemic treatment naive, stage IV NSCLC patients (pts). Eligible pts received KN046 plus platinum doublet chemotherapy until progressive disease, unacceptable toxicity, withdrawal of informed consent or death. Efficacy evaluation was performed by investigators per RECIST 1.1. Safety and tolerability were assessed per NCI-CTCAE v5.0. Results: As of the Jan. 19, 2021, 87 pts [Cohort 1 (n = 51), Cohort 2 (n = 36)] have been enrolled with 83 pts having tumor PD-L1 expression data (PD-L1 ≥1%: 55.4%; PD-L1 < 1%: 44.6%). 33.3% pts remained on the study treatment and 66.7% pts discontinued treatment due to disease progression (27.6%), TEAE (13.8%), death (9.2%) and other reasons (16%). The median treatment duration of KN046 was 21 weeks (range: 1.6̃68.7 weeks). Treatment related TEAE (TRAE) occurred in 92% pts. 25.3% pts experienced Grade≥3 TRAE [diarrhoea (5.7%), alanine aminotransferase increased (4.6%), infusion related reaction (3.4%), rash (3.4%), aspartate aminotransferase increased, dermatitis allergic and immune-mediated pneumonitis (2.3%, respectively), anaphylactoid reaction, autoimmune hepatitis, back pain, bilirubin conjugated increased, hypertension, neutrophil count decreased, platelet count decreased, pneumonitis, rash maculo-papular, septic shock and white blood cell count decreased (1.1%, respectively). In 81 efficacy evaluable pts, the overall objective response rate (ORR) was 50.6% (95% CI: 39.3%,61.9%) and disease control rate (DCR) was 87.7% (95% CI: 78.5%-93.9%). The ORR and DCR in pts with non-squamous NSCLC (n = 48) were 45.8% (95% CI: 31.4%, 60.8%) and 89.6% (95% CI: 77.3%, 96.5%). The ORR and DCR in pts with squamous NSCLC (n = 33) were 57.6% (95% CI: 39.2%, 74.5%) and 84.8% (95% CI: 68.1%, 94.9). Progression free survival (PFS) and OS events have occurred in 53% and 18% patients. Median PFS was 5.9 (95%CI: 5.3, 8.7) months. Median OS was not reached. OS rate at 12 and 15 months were both 74.9%. Similar OS curves have been observed in PD-L1 ≥1% and PD-L1 < 1% pts. In PD-L1 ≥1% patients, median PFS was 6.7 months (10.8 months for PD-L1 ≥1% squamous NSCLC pts). Conclusions: KN046 combined with platinum doublet chemotherapy is tolerated and has shown promising clinical benefit as IL treatment for stage IV NSCLC particularly in PD-L1≥1% tumors and squamous histology. Pivotal Phase III trial in advanced unresectable or metastatic squamous NSCLC is currently ongoing. Clinical trial information: NCT04054531.

Anti-PD-L1 antibody direct activation of macrophages contributes to a radiation-induced abscopal response in glioblastoma

BACKGROUND

Most glioblastomas recur near prior radiation treatment sites. Future clinical success will require achieving and optimizing an "abscopal effect," whereby unirradiated neoplastic cells outside treatment sites are recognized and attacked by the immune system. Radiation combined with anti-programmed cell death ligand 1 (PD-L1) demonstrated modest efficacy in phase II human glioblastoma clinical trials, but the mechanism and relevance of the abscopal effect during this response remain unknown.

METHODS

We modified an immune-competent, genetically driven mouse glioma model (forced platelet derived growth factor [PDGF] expression + phosphatase and tensin homolog loss) where a portion of the tumor burden is irradiated (PDGF) and another unirradiated luciferase-expressing tumor (PDGF + luciferase) is used as a readout of the abscopal effect following systemic anti-PD-L1 immunotherapy. We assessed relevance of tumor neoepitope during the abscopal response by inducing expression of epidermal growth factor receptor variant III (EGFRvIII) (PDGF + EGFRvIII). Statistical tests were two-sided.

RESULTS

Following radiation of one lesion, anti-PD-L1 immunotherapy enhanced the abscopal response to the unirradiated lesion. In PDGF-driven gliomas without tumor neoepitope (PDGF + luciferase, n = 8), the abscopal response occurred via anti-PD-L1 driven, extracellular signal-regulated kinase-mediated, bone marrow-derived macrophage phagocytosis of adjacent unirradiated tumor cells, with modest survival implications (median survival 41 days vs radiation alone 37.5 days, P = 0.03). In PDGF-driven gliomas with tumor neoepitope (PDGF + EGFRvIII, n = 8), anti-PD-L1 enhanced abscopal response was associated with macrophage and T-cell infiltration and increased survival benefit (median survival 36 days vs radiation alone 28 days, P = 0.001).

CONCLUSION

Our results indicate that anti-PD-L1 immunotherapy enhances a radiation- induced abscopal response via canonical T-cell activation and direct macrophage activation in glioblastoma.

The preliminary efficacy and safety data of KN046 in patients failed on prior immune checkpoint inhibitors therapy

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Background: KN046 is a bispecific antibody that blocks PD-L1 and CTLA-4 by interaction with PD1 and CD80/CD86. KN046-CHN-001 (NCT03529526) is a, dose escalation and expansion phase Ia/Ib clinical trial in China. Here we reported safety, tolerability and preliminary efficacy in patients failed on prior immune checkpoint inhibiters (ICIs) treatment. Methods: Patients progressed on ICIs (including but not limited to antibodies targeting PD-1, PD-L1, OX40, et al) with pathologically confirmed solid tumor, ECOG 0-1, measurable lesion per RECIST v1.1, no immune-related adverse events (IRAEs) led to ICIs discontinuation, were enrolled and received intravenous KN046 treatment across four dose levels including 3.0 mg/kg (n = 3) and 5.0 mg/kg (n = 20) Q2W; and 5.0 mg/kg (n = 4), 300.0 mg flat dose (n = 2) Q3W. Safety and tolerability were assessed per NCI-CTCAE v5.0. Treatment-emergent AEs (TEAEs) and IRAEs were decided by investigators. Efficacy was evaluated by investigators per RECIST 1.1 every 6 weeks. Results: Twenty-nine who progressed on prior ICIs therapy were enrolled (25anti-PD-1 antibody; 3 anti-OX40 antibody; and 1 anti-CD137 antibody) and were included in the current analysis. Among 29 patients, 19 were nasopharyngeal cancer (NPC) and 9 were non-small cell lung cancer (NSCLC). The median duration of the exposure of KN046 was 12 weeks (range 2 to 40). Eleven patients remained on the treatment and 18 discontinued due to disease progression (n = 13), AE (n = 1), death (n = 1) and others (n = 3). Twenty-six (89.7%) patients experienced TRAEs of all grades and 2 (6.9%) experienced grade≥3 TRAEs (1 grade 3 anemia and 1 grade 3 infusion-related reaction). The most common (≥10%) TRAEs were pruritus (8, 27.6%), rash (8, 27.6%), asthenia (6, 20.7%), fatigue (6, 20.7%), pyrexia (5, 17.2%), infusion related reaction (4, 13.8%), alanine aminotransferase elevation (3, 10.3%) and white blood cell count elevation (3, 10.3%). Eleven (37.9%) patients experienced irAEs (with no grade≥3). Objective responses were occurred in 3 (12.0%, 25 evaluable) patients, disease control rate was 52.0% (10 stable disease). Median progression free survival was 2.69 (95%CI 1.31,5.52) months. Median overall survival was not reached. PFS rates for 3 and 6 Months were 41.0% (95%CI 18.5, 62.5) and 21.9% (95%CI 4.6, 47.3). OS rates for 6 and 9 months were88% (95%CI 57.2, 97.1) and 58.7% (95%CI 8.3, 89.2), respectively. Conclusions: Overall, KN046 showed a favorable safety profile and promising clinical benefit in advanced solid tumor patients who failed on prior ICIs therapy. Clinical trial information: NCT03529526 .

Preliminary safety, efficacy and pharmacokinetics (PK) results of KN026, a HER2 bispecific antibody in patients (pts) with HER2-positive metastatic breast cancer

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Background: KN026 is a novel bispecific antibody that simultaneously binds to two distinct HER2 epitopes, the same domains as trastuzumab (ECD4) and pertuzumab (ECD2). It blocks ligand-dependent and independent tumor growth and enhances HER2 receptor internalization. In preclinical studies, KN026 showed activity in trastuzumab plus pertuzumab resistant tumor cell lines. This first-in-human study evaluated the safety/tolerability, pharmacokinetics (PK), and preliminary efficacy of KN026 monotherapy. Methods: This dose-escalation and expansion study enrolled Chinese patients (pts) with metastatic breast cancer who have failed prior anti-HER2 therapy. All pts intravenously received KN026 monotherapy at ascending dose of 5 mg/kg (QW), 10 mg/kg (QW), 20 mg/kg (Q2W) or 30 mg/kg (Q3W). Dose limiting toxicity (DLT) evaluation period was 28 days for QW and Q2W, and 21 days for Q3W. Efficacy evaluation was performed by RECIST 1.1 every 6 weeks and safety assessment according to CTCAE v 4.03. Results: As of the Jan, 22, 2020, 63 pts [median age: 54 years (31~69)] enrolled and 62 pts were included in the efficacy analysis. 41 pts remained on treatment and 22 pts discontinued treatment due to disease progression (n = 21) and adverse events (n = 1). The median treatment duration was 12 weeks (range: 4~62 weeks). Median prior lines of therapies are 3 (range: 1~15), and median prior lines of HER2 target therapies are 2 (range: 1~12). No DLTs were observed. Treatment-related AEs (TRAEs) occurred in 49 pts and 4 pts experienced 4 grade 3 TRAE (hypertension, infusion related reaction, transaminases increased and ventricular arrhythmia). The common (≥ 10%) TRAE were pyrexia (23.8%), diarrhea (19.0%), aspartate aminotransferase increased (15.9%), neutrophil count decreased (11.1%) and white blood cell count decreased (11.1%). The objective response rate at recommended Phase 2 dose levels (n = 56) was 32.1% (95% CI 20.3, 46.0) and disease control rate 76.8% (95% CI 63.6, 87.0). Pharmacokinetic analysis showed exposure (Cmax and AUC0-t) of KN026 increased by dose. The recommended Phase 2 dose (RP2D) were 20 mg/kg Q2W and 30 mg/kg Q3W. Conclusions: KN026 is well tolerated and has demonstrated encouraging anti-tumor activity in HER2-positive breast cancer patients who have failed standard anti-HER2 therapies. The recommended Phase 2 dose (RP2D) of KN026 were 20 mg/kg Q2W and 30 mg/kg Q3W. Phase II trials in various HER2-positive and HER2-low/intermediate solid tumors are currently ongoing. Clinical trial information: NCT03619681 .

Increased expression of miR-330-3p: a novel independent indicator of poor prognosis in human breast cancer

OBJECTIVE

Previous study has reported that miR-330-3p was highly expressed in breast cancer (BC) patients. However, the effect of miR-330-3p in BC progression remains largely unclear. The purpose of this study was to investigate the clinical significance of miR-330-3p expression in BC.

PATIENTS AND METHODS

The expression of miR-330-3p was detected by quantitative Real-time PCR in BC tissues and matched normal breast tissues. The association of miR-330-3p expression with clinicopathological factors of BC patients was also analyzed by x2-test. Prognosis value of patients with BC was assessed by Kaplan-Meier method and Cox proportional hazards model, respectively.

RESULTS

Quantitative real-time PCR analysis showed that the expression level of miR-330-3p was significantly higher in BC specimens than that in corresponding noncancerous tissues (p < 0.01). The levels of miR-330-3p were positively correlated with the status of TNM stage (p = 0.011) and lymph node metastasis (p = 0.006). Kaplan-Meier analysis revealed that 5-year overall survival of BC patients with high miR-330-3p expression was shorter compared to those patients with low miR-330-3p expression (p < 0.0001). Moreover, univariate and multivariate regression analysis demonstrated that miR-330-3p was an independent prognostic factor in BC.

CONCLUSIONS

Our data suggest that miR-330-3p upregulation maybe concurrently associated with prognosis in patients with BC, suggesting that miR-330-3p may be a potential prognostic biomarker and therapeutic target for patients with BC.

Preliminary safety, efficacy, and pharmacokinetics (PK) results of KN046 (bispecific anti-PD-L1/CTLA4) from a first-in-human study in subjects with advanced solid tumors

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Background: KN046 is a novel bispecific antibody that blocks both PD-L1 interaction with PD1 and CTLA-4 interaction with CD80/CD86. KN046 has a wild type IgG1 Fc portion that preserves intact effector functions, such as depletion of Tregs in tumor microenvironments. This first-in-human study evaluated the safety, tolerability, PK and preliminary efficacy of KN046 in subjects with advanced solid tumors. Methods: This traditional “3+3” dose-escalation design study enrolled patients (pts) with advanced unresectable or metastatic solid tumors refractory or intolerant to standard therapies. Previous treatment from PD1 or PD-L1 immune checkpoint inhibitors was allowed. KN046 was administered intravenously Q2W. Dose limit toxicity (DLT) evaluation period is 28 days. The planned dose levels (DL) were 0.3, 1, 3, 5 and 10 mg/kg. Efficacy evaluation was performed by RECIST 1.1 every 8 weeks. Results: As of Dec 13, 2018, 10 pts had been enrolled (0.3 mg/kg, n = 1; 1 mg/kg, n = 3; 3 mg/kg, n = 3; and 5 mg/kg, n = 3). Median duration of treatment was 8 (range: 2-24) weeks. 1 DLT was observed at 5 mg/kg dose (a grade 3 immune-related hepatitis without elevation in total bilirubin; reversible in two weeks). The most common (≥30%) treatment-emergent AEs (TEAE) were Fatigue, Diarrhea, Nausea, Vomiting. Six immune-related TEAEs (Abdominal pain lower, Arthralgia, Hepatic function abnormal, Hyperthyroidism, Nausea and Transaminitis) were observed in 3 pts. One pt with NSCLC from 3 mg/kg cohort had confirmed completed response. Two pts (TNBC and nivolumab refractory RCC) from 1 mg/kg cohort had shown long-term stable disease ( > 12 weeks). Faster clearance of KN046 was observed at lower dose might be due to target-mediated clearance. T1/2 is approximately 7~9 days at doses of 3 mg/kg and above when saturation occurs. Conclusions: Single agent KN046 has an acceptable safety profile and is in line with previously reported safety data from other immune checkpoint inhibitors. Preliminary efficacy results are promising. PK data from initial 4 cohorts support Q2W schedule. The study is currently ongoing at dose level of 5 mg/kg Q2W. Clinical trial information: NCT03529526.

Preventing Soil Inoculum of Calonectria pseudonaviculata from Splashing onto Healthy Boxwood Foliage by Mulching

Boxwood blight, caused by Calonectria pseudonaviculata, is an emerging disease of great concern to horticulturists in the United States and other affected countries. The objective of this study was to evaluate the efficacy of mulching as a physical barrier to prevent soil inoculum from splashing onto healthy boxwood foliage. A field trial consisting of two treatments, mulched and nonmulched, was conducted under field conditions in Lowgap, North Carolina, and in a residential landscape setting near Richmond, Virginia, for 2 years at each site. Mulching efficacy was assessed by monitoring and comparing boxwood blight development on detector plants: containerized 'Justin Brouwers' boxwood, which were rotated through mulched and nonmulched plots at 1- and 2-week intervals in the Lowgap and Richmond sites, respectively. Boxwood blight was observed on detector plants in a combined 55 of the 88 monitoring periods during this study at the two sites. Mulching provided complete protection of Justin Brouwers boxwood from infection by C. pseudonaviculata soil inoculum during 33 of the 55 positive monitoring periods (60%) and good to excellent protection during 13 monitoring periods (24%). The potential applications of mulching for boxwood blight mitigation are discussed.

Microwave ablation combined with doxorubicin enhances cell death via promoting reactive oxygen species generation in breast cancer cells

PURPOSE

To evaluate the mechanism for enhancing cell death induced by microwave ablation (MWA) combined with doxorubicin treatment in breast cancer cells.

MATERIALS AND METHODS

Different temperatures of heat treatment were used to mimic the tumor affected by sublethal heat during MWA in vitro. Breast cancer cells were treated at 43°C and 45°C, with or without doxorubicin. Cell viability, apoptosis, and intracellular reactive oxygen species (ROS) were evaluated in MDA-MB-231 and SUM-1315 cells. Nude mice breast cancer models were randomly divided into control, MWA, doxorubicin, and combined treatment groups. Tumor apoptosis and DNA damage were evaluated in these groups.

RESULTS

The combined group had lower cell viability than the heat or doxorubicin group (all P<0.05), and enhanced apoptosis rate was observed in the combined group compared to others (all P<0.01) in MDA-MB-231 and SUM-1315. Increased capase3 (all P<0.01) and decreased Bcl-Xl (all P<0.01) were detected after combined therapy compared to single treated group in vitro. The raisedCaspase3 and DNA damage marker histone H2A.X induced by combined treatment were also approved in the nude mice models. Combined treatment promoted ROS generation compared to doxorubicin or MWA treatment (all P < 0.01). NF-κB expression in the combined group was higher than that of the single treatment group (all P<0.05). N-acetylcysteine (NAC), a ROS scavenger, partly restrained the combined treatment induced cell proliferation inhibition, Caspase3 and NF-κB compared to doxorubicin treatment (all P<0.05).

CONCLUSION

MWA combined with doxorubicin promote cell death via ROS induced cell apoptosis and DNA damage. Increasing ROS has potential for improving the efficiency of combined treatment.

Enhanced antitumor efficacy through microwave ablation in combination with immune checkpoints blockade in breast cancer: A pre-clinical study in a murine model

PURPOSE

The purpose of this study was to investigate the therapeutic efficacy of the combination of microwave ablation (MWA) in combination with immune checkpoints blockade in the treatment of breast cancer using the 4T1 tumor-bearing mice model.

MATERIALS AND METHODS

We treated tumor-bearing mice with MWA, programmed cell death protein1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) blockade (P+C), MWA plus PD-1 and CTLA-4 blockade (combination therapy), or no-treatment. Survival time was evaluated with the Kaplan-Meyer method comparing survival curves by log-rank test. On day 15 after MWA, five mice from the combination therapy group received tumor rechallenge with 4T1 or CT26 cells and the volumes of rechallenge tumor were calculated every 5 days. Immune cells were identified by immunohistochemistry and flow cytometry, and the concentrations of plasma interferon-γ (IFN-γ) were identified by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The combination therapy significantly prolonged tumor-bearing mice survival compared to no-treatment group, P+C group or MWA group (P<0.001, P<0.001 and P=0.01, respectively) and protected most surviving mice from 4T1 tumor rechallenge (P=0.002) but not CT26 tumor rechallenge (P=0.905). Both local and systemic CD8+ T-cell responses were induced by MWA (all P<0.05) and further augmented by subsequent administration of PD-1 and CTLA-4 blockade (all P<0.05). Plasma IFN-γ concentrations were significantly elevated in the combination therapy group compared to no-treatment group, P+C group or MWA group (P<0.001, P<0.001 and P=0.01, respectively).

CONCLUSION

MWA combined with immune checkpoints blockade could synergistically enhance antitumor efficacy with augmented specific immune responses, and the combination therapy is a promising approach to treat breast cancer.

Avalanche dynamics of granular materials under the slumping regime in a rotating drum as revealed by speckle visibility spectroscopy

We used speckle visibility spectroscopy to measure the time-resolved dynamcis of avalanching down the inclined surface of a granular material in a half-full rotating drum operating in the slumping regime. The distribution of the avalanche period, t(d), rest time between them, t(r), and peak particle velocity fluctuation, δv(p)(2), are all normally distributed. While the distributions of the two times at the top and bottom of the free surface are very similar, the particle velocity fluctuation is greater at the bottom of the free surface than at the top. The rest time is observed to be inversely related to the drum speed. Combining this with the relation of t(r) and the difference of the upper and lower angle of repose for the granular material, Δθ, we find that the latter decreases linearly with increasing rotational speed. We also observe that t(d) increases in a linear fashion with the drum speed. Using the relation of t(r) and the distance that particles have to move during an avalanche, we further find that a new scaling relation of the mean number of avalanches required to traverse the free surface with drum speed. We find that the slumping frequency increases with the rotating speed before becoming constant in the slumping-to-rolling transition region. Finally, we find that the average peak of the fluctuation speed of the avalanche, δv(p)(2), increases linearly with the drum speed.

Long-term outcome of HLA-haploidentical hematopoietic SCT without in vitro T-cell depletion for adult severe aplastic anemia after modified conditioning and supportive therapy

HLA-haploidentical hematopoietic SCT (HSCT) is an option for severe aplastic anemia (SAA) patients. Here, we evaluated the outcomes of 26 adult-SAA patients who received HLA-haploidentical HSCT in five transplant centers in southwestern China. Most of the patients in this study failed prior therapy and were transfused heavily before the transplantation. The patients received fludarabine+cyclophosphamide+antithymocyte globulin as conditioning regimens and then unmanipulated peripheral blood plus marrow transplantation. Micafungin, i.v. Ig and recombinant human TPO were used for post-grafting infection prevention and supportive care. Of 26 patients, 25 achieved engraftment at a median of 13 days (range, 11-19 days) after HSCT. One of 25 patients experienced graft rejection and did not achieve sustained engraftment after second HSCT. Therefore, the final engraftment rate was 92.3%. Three of 25 (12%) patients developed acute GVHD, 10 of 25 (40%) patients developed chronic GVHD (9 with limited whereas the other with extensive). The OS rate was 84.6% and the average follow-up time was 1313.2 (738-2005) days for surviving patients. This encouraging result suggests that HLA-haploidentical HSCT is an effective therapeutic option for adults with acquired SAA if an HLA-identical donor is not available.

Phytophthora hedraiandra Detected from Irrigation Water at a Perennial Ornamental Plant Nursery in Virginia

Water survey for Phytophthora spp. by baiting with rhododendron leaves in April 2006 at a perennial ornamental plant nursery in Virginia detected five isolates showing a unique, previously unknown single-strand conformation polymorphism (SSCP) fingerprint (1). These cultures were isolated from two reservoirs at different depths of water column from surface to 2 m. They were homothallic and produced smooth-surfaced spherical oogonia with an average diameter of 27 μm on 10% V8 agar. Oospores were aplerotic. The paragynous antheridia were averaging 12 μm in diameter. Sporangia were papillate, spherical to ovoid, averaging 39 by 28 μm (length by width). They were caducous with short (<4 μm) pedicels. Chlamydospores and hyphal swellings were not observed. Two isolates were sequenced for rDNA internal transcribed spacer (ITS) 1 and 2 regions and cytochrome oxidase subunit 1 (Cox 1) gene. ITS sequences of both isolates (GenBank Accession Nos. JN376065 and JN376066) were identical to that of Phytophthora hedraiandra type culture (GenBank Accession No. AY707987). Also, the Cox 1 sequence of an isolate (Accession No. JN376067) had 99% homology with that of the type culture (GenBank Accession No. AY69115). Pathogenicity of both isolates was tested on Rhododendron catawbiense and Viburnum tinus, two known hosts of P. hedraiandra (2). For each isolate and host, five leaves and stems on potted plants were wounded by needles and then inoculated by placing over each wound a 5-mm² mycelial plug from a 7-day-old culture and securing with Parafilm. V8 agar was used instead of mycelial plugs on control plants. After inoculation, each plant was enclosed in a plastic bag for 1 day and then incubated at 22°C with a 12-h photoperiod. Distilled water was sprayed daily for 5 days postinoculation (dpi) until disease symptoms were observed. At 15 dpi, 3 of the 10 inoculated rhododendron leaves and 6 of the 10 stems showed leaf lesions, wilting, dieback, and cankers, eventually leading to rhododendron death. Two of the 10 viburnum leaves and 4 of the 10 stems showed similar symptoms. Leaf lesions were approximately 3 to 5 cm in diameter. P. hedraiandra was recovered from diseased tissues and all resulting cultures showed an identical SSCP fingerprint to tested isolates as well as a P. hedraiandra isolate from Minnesota (3). No symptom developed on control plants. To our knowledge, this is the first report of P. hedraiandra in Virginia. Considering neither host plant has been grown or bought for resale by this nursery, this study indicates that P. hedraiandra may have a wider host range than is currently known. This possibility and the importance of water dispersal for P. hedraiandra in disease epidemiology warrant further investigation. References: (1) P. Kong et al. Fungal Genet. Biol. 39:238, 2003. (2) W. A. Man in't Veld et al. Eur. J. Plant Pathol. 117:25, 2007. (3) B. W. Schwingle et al. Plant Dis. 90:109, 2006.

Effects of bone marrow stromal cells and umbilical cord blood-derived stromal cells on daunorubicin-resistant residual Jurkat cells

OBJECTIVE

To observe the effects of the hematopoietic inductive microenvironment (HIM) simulated by stromal cells of different origins on daunorubicin-resistant residual Jurkat cells (Jurkat/DNR cells).

METHODS

Jurkat/DNR cells were cultured and identified. Human umbilical cord blood-derived stromal cells (UCBDSCs) and normal human bone marrow stromal cells (BMSCs) were isolated and cocultured with Jurkat/DNR cells. Jurkat/DNR cells were collected after 14 days of coculture and analyzed with regard to cell proliferation and differentiation abilities, apoptosis, drug sensitivity, and MRD1 multidrug resistance gene mRNA expression.

RESULTS

UCBDSC-simulated HIM suppressed proliferation and promoted apoptosis, differentiation, and drug sensitivity of Jurkat/DNR cells more significantly than BMSC-simulated HIM.

CONCLUSIONS

Both BMSCs and UCBDSCs reconstruct the leukemic HIM and reverse drug resistance in Jurkat/DNR cells. UCBDSCs reconstruct the leukemic HIM and reverse drug resistance more significantly than BMSCs.

Evidence for a DC-specific inhibitory mechanism that depends on MyD88 and SIGIRR

Dendritic cells (DC) are an essential link between the innate and adaptive immune response. To become effective antigen-presenting cells DC need to undergo maturation, during which they up-regulate co-stimulatory molecules and produce cytokines. There is great interest in utilizing DC in vaccination regimes. Over recent years, Toll-like receptor (TLR) signalling has been recognized to be one of the major inducers of DC maturation. This study describes a mutant version of the TLR adaptor molecule MyD88 (termed MyD88lpr) as a novel adjuvant for vaccination regimes. MyD88lpr specifically activates DC by disrupting a DC intrinsic inhibitory mechanism, which is dependent on single immunoglobulin IL-1R-related. Moreover, MyD88lpr was able to induce an IgG2a-dominated response to a co-expressed antigen, suggesting Th1 immunity. However, when used as a vaccine adjuvant for Influenza nucleoprotein there was no significant difference in the lung viral titres during the infection. This study describes MyD88lpr as a potential adjuvant for vaccinations, which would be able to target DC specifically.

The avocado subgroup of Phytophthora citricola constitutes a distinct species, Phytophthora mengei sp. nov

Isolates from avocado tree cankers have been recognized as a distinct subgroup within the P. citricola complex since 1974, both morphologically and molecularly (isozyme and amplified fragment length polymorphism [AFLP] analyses). This subgroup is formally separated from P. citricola after comparative DNA fingerprinting and sequence analyses of the ITS region, as well as by morphological examinations. This new taxon is homothallic, produces plerotic oospores with paragynous antheridia and noncaducous semipapillate sporangia. Morphologically it differs from other species of Waterhouse group III by producing many large bizarre-shaped sporangia and smaller oogonia with asymmetric capitate antheridia. It belongs to clade 2 and is phylogenetically closer to P. siskiyouensis, P. capsici and P. tropicalis than to P. citricola. P. mengei can be easily differentiated from its relatives in the same clade and other species of this morpho-group by DNA fingerprints and sequence analysis. This new taxon is named Phytophthora mengei sp. nov.

Phytophthora tropicalis Isolated from Diseased Leaves of Pieris japonica and Rhododendron catawbiense and Found in Irrigation Water and Soil in Virginia

An unidentified species of Phytophthora was isolated from irrigation water at a production nursery in Suffolk, VA in 2000 and 2001. Water samples were assayed using a filtration method (3). A similar species was recovered from soil samples collected in two mixed-hardwood forests in Fairfax County in 2002. Soil samples were air dried, remoistened, flooded, and then baited with rhododendron and camellia leaf pieces at room temperature (22 to 24°C) (2). A Phytophthora sp. was recovered from bait pieces cultured on PARPH-V8 selective medium (2). This same species also was isolated from symptomatic leaves of Pieris japonica cv. Temple Bells and Rhododendron catawbiense cv. Maximum Roseum at a garden center in Virginia Beach in 2004. On P. japonica, symptoms appeared as water-soaked, necrotic lesions and marginal necrosis on leaves and necrosis of shoot tips; on R. catawbiense, symptoms were wilting, dieback, and death of shoots. Representative isolates produced semipapillate to papillate sporangia with tapered bases that were caducous and had long pedicels (16 to 120 μm). Sporangia on four isolates were measured: mean lengths were 40.6 to 48.4 μm, mean widths were 26.9 to 31.4 μm, and length/width ratios consistently were 1.5. Sporangia occasionally were distorted and had dual apices, and they often contained a large globule after zoospore release. Chlamydospores ranged from 25 to 32 μm in diameter. All isolates were heterothallic; four isolates paired with known isolates of P. nicotianae were found to be mating type A1. Optimum temperature for mycelium growth on cornmeal agar was 25°C with slight growth at 35°C by some isolates and no growth at 4°C. These morphological characteristics were mostly consistent with those of P. tropicalis (1). P. tropicalis is reported to have sporangia that are papillate, have lengths of 40 to 55 μm, widths of 19 to 27 μm, and length/width ratios of 1.8 to 2.4 (1). The identity of these isolates as P. tropicalis was confirmed using single-strand conformational polymorphism analysis with comparison to a reference isolate (4). These isolates have been retained in permanent collections in the Hong and Jeffers labs. One isolate from each host plant and one isolate from irrigation water were tested for pathogenicity; agar blocks of mycelium (4 × 4 mm) were placed on wounded and nonwounded leaves of P. japonica cv. Mountain Fire and R. catawbiense cv. Olga plants and wrapped with Parafilm to prevent desiccation. Lesions formed on wounded and nonwounded leaves after 4 days at 20 to 30°C, and P. tropicalis was reisolated; no lesions formed on noninoculated control leaves. To our knowledge, this is the first report of P. tropicalis in the continental United States, in irrigation water systems, and as a cause of Phytophthora foliage blight on P. japonica and R. catawbiense (1). This study suggests that the host range of this pathogen is not limited to tropical plants. Although this pathogen did not cause significant economic loss in the garden center surveyed, it was isolated in irrigation water at the production nursery from late spring through fall. An investigation of its impact on nursery crops is warranted. References: (1) M. Aragaki and J. Y. Uchida. Mycologia 93:137, 2001. (2) A. J. Ferguson and S. N. Jeffers. Plant Dis. 83:1129, 1999. (3) C. X. Hong et al. Phytopathology 92:610, 2002. (4) P. Kong et al. Fungal Genet. Biol. 39:238, 2003.

Role for macrophage migration inhibitory factor in asthma

Macrophage migration inhibitory factor (MIF) is an immunologic regulator that is expressed in inflammatory and autoimmune disorders. We investigated MIF's role in asthma using genetic approaches in a mouse model and in a cohort of asthma patients. Mice genetically deficient in MIF that were primed and aerosol-challenged with ovalbumin showed less pulmonary inflammation and lower airway hyperresponsiveness than genetically matched, wild-type controls. MIF deficiency also resulted in lower titers of specific IgE, IgG(1), and IgG(2a), and decreased pulmonary, T(H)2 cytokine levels. IL-5 concentrations were lower and corresponded to decreased eosinophil numbers in bronchoalveolar lavage fluid. T cell studies also showed a lower level of antigen-specific responses in MIF-KO versus wild-type mice. In an analysis of 151 white patients with mild, moderate, or severe asthma (Global Initiative for Asthma criteria), a significant association was found between mild asthma and the low-expression, 5-CATT MIF allele. Pharmacologic inhibition of MIF may be beneficial and could be guided by the MIF genotype of affected individuals.

Shoot Blight of Forsythia × intermedia in Virginia Nurseries Caused by Phytophthora nicotianae

A severe blighting of shoots on Forsythia × intermedia cv. Lynwood Gold plants was observed at several commercial nurseries in Virginia from 2001 to 2004. Crop losses ranged from 10 to 35%. Symptoms first occurred at the tips of shoots, including those that were trimmed and not trimmed, and then progressed downward. Diseased shoots wilted quickly and usually turned black, and foliage on these shoots withered and became necrotic. With PARP-V8 selective medium (2), a species of Phytophthora was isolated consistently from symptomatic shoots (including tissues from shoot tips, leaves, and stems) as well as from apparently healthy roots. These isolates produced arachnoid mycelia and numerous noncaducous, papillate sporangia but did not produce sexual structures on isolation plates; these morphological characters are consistent with those of Phytophthora nicotianae. All isolates produced a single-strand conformation polymorphism pattern typical of P. nicotianae (3). To test pathogenicity, 1-year-old, healthy-appearing cv. Lynwood Gold forsythia plants (canopy size = 100 cm × 60 cm) in four 12-liter containers were sheared. Two plants were inoculated by spraying each plant with 200 ml of a zoospore suspension (1.6 × 10⁴ spores per ml, prepared from one isolate), and the other two plants were not treated and served as controls. Plants were covered with plastic bags overnight to encourage infection and then were grown in a field (temperature range = 20 to 33°C). Severe blight developed on trimmed shoots and new shoot tips of inoculated plants within 1 week after inoculation. The same pathogen was isolated from all blighted leaf and stem pieces assayed. Blight symptoms were not observed on control plants during a 1-month observation period. Phytophthora nicotianae has been reported to attack F. viridissima in Italy (1) causing root and collar rot but not shoot blight. To our knowledge, this is the first report of shoot blight on Forsythia spp. caused by P. nicotianae and the first report of P. nicotianae on Forsythia spp. in the United States. References: (1) S. O. Cacciola et al. Plant Dis. 78:525, 1994. (2) A. J. Ferguson and S. N. Jeffers. Plant Dis. 83:1129, 1999. (3) P. Kong et al. Fun. Gen. Biol. 39:238, 2003.

Cognitive-behavioral group program for Chinese heterosexual HIV-infected men in Hong Kong

This study explored the effects of cognitive-behavioral program (CBP) using a wait-list control group in 16 Chinese heterosexual HIV-infected men. Participants in the treatment condition underwent a 7-week group based CBP, which addressed various HIV-related issues. Relevant cognitive and behavioral strategies were taught as well. The aim of treatment was to improve the quality of life and to reduce psychological distress in a sample of heterosexual symptomatic HIV-infected men. Prior to intervention, baseline measures showed that our sample had a lower quality of life in comparison with the local general population. They also experienced a significant level of psychological distress. Following intervention, men in the CBP group demonstrated significant improvement in the mental health dimension of quality of life and a significant reduction in depressed mood. These preliminary findings suggested that short-term cognitive-behavioral therapy can be effective in improving the quality of life and mood of Chinese heterosexual HIV-infected men.

Rapid identification of Phytophthora ramorum using PCR-SSCP analysis of ribosomal DNA ITS-1

AIMS

The primary objectives of this study were to determine if a single-strand conformation polymorphism (SSCP) analysis can be used for rapid identification of Phytophthora ramorum, an important quarantine plant pathogen worldwide, and to further assess the potential of the SSCP technique as a taxonomic tool for the genus Phytophthora.

METHODS AND RESULTS

SSCP of ribosomal DNA internal transcribed spacer 1 was characterized for 12 isolates of P. ramorum, using a recently reported protocol. The SSCP patterns of this species then were compared with those of 18 closely related Phytophthora species. Phytophthora ramorum had a unique pattern and was easily distinguished from genetically, morphologically and ecologically close relatives.

CONCLUSION

An immediate benefit of this study is provision of a highly effective and efficient identification tool for P. ramorum in the quarantine process.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study also provides additional evidence demonstrating that the SSCP is an ideal DNA marker for species differentiation within the genus Phytophthora.

Efficacy of Chlorine on Multiple Species of Phytophthora in Recycled Nursery Irrigation Water

Recycled irrigation water is a primary source of inoculum for Phytophthora spp. and is capable of spreading propagules throughout nursery production. Chlorination commonly is used by the industry to disinfest recycled irrigation water; however, chlorine has not been fully researched as a disinfestant for this purpose. In this study, zoospores of seven species and eight isolates of Phytophthora were exposed for 2 min to free available chlorine at 0.25, 0.5, 1.0, 2.0, and 4.0 mg/liter. Zoospores, mycelial fragments, and culture plugs of P. nicotianae also were exposed to chlorine concentrations ranging from 0.25 to 8.0 mg/liter for periods ranging from 15 s to 8 min. In addition, chlorinated water was assayed monthly in 2000 and 2001 at two commercial nurseries, and quarterly in the first year at four other nurseries in Virginia, for chlorine and survival of pythiaceous species using a selective medium. No zoospores of any species tested survived endpoint free chlorine at 2 mg/liter, while limited mycelial fragments of P. nicotianae survived at 8 mg/liter, and mycelial plugs treated at the same level of chlorine were able to produce few sporangia. Phytophthora spp. were recovered only from nursery irrigation water with levels of free chlorine at 0.77 mg/liter or lower. The results of this study are essential for improving current chlorination protocols.

Priming of memory but not effector CD8 T cells by a killed bacterial vaccine

Killed or inactivated vaccines targeting intracellular bacterial and protozoal pathogens are notoriously ineffective at generating protective immunity. For example, vaccination with heat-killed Listeria monocytogenes (HKLM) is not protective, although infection with live L. monocytogenes induces long-lived, CD8 T cell-mediated immunity. We demonstrate that HKLM immunization primes memory CD8 T lymphocyte populations that, although substantial in size, are ineffective at providing protection from subsequent L. monocytogenes infection. In contrast to live infection, which elicits large numbers of effector CD8 T cells, HKLM immunization primes T lymphocytes that do not acquire effector functions. Our studies show that it is possible to dissociate T cell-dependent protective immunity from memory T cell expansion, and that generation of effector T cells may be necessary for long-term protective immunity.

Genetic variation of Citrus tristeza virus isolates from California and Spain: evidence for mixed infections and recombination

We examined the population structure and genetic variation of four genomic regions within and between 30 Citrus tristeza virus (CTV) isolates from Spain and California. Our analyses showed that most isolates contained a population of sequence variants, with one being predominant. Four isolates showed two major sequence variants in some genomic regions. The two major variants of three of these isolates showed very low nucleotide identity to each other but were very similar to those of other isolates, suggesting the possibility of mixed infections with two divergent isolates. Incongruencies of phylogenetic relationships in the different genomic regions and statistical analyses suggested that the genomes of some CTV sequence variants originated by recombination events between diverged sequence variants. No correlation was observed between geographic origin and nucleotide distance, and thus from a genetic view, the Spanish and Californian isolates analyzed here could be considered members of the same population.

Population structure and genetic diversity within California Citrus tristeza virus (CTV) isolates

The Closterovirus, Citrus tristeza virus (CTV) is an aphid-borne RNA virus that is the causal agent of important worldwide economic losses in citrus. Biological and molecular variation has been observed for many CTV isolates. In this work we detected and analyzed sequence variants (haplotypes) within individual CTV isolates. We studied the population structure of five California CTV isolates by single strand conformation polymorphism (SSCP) analysis of four CTV genomic regions. Also, we estimated the genetic diversity within and between isolates by analysis of haplotype nucleotide sequences. Most CTV isolates were composed of a population of genetically related variants (haplotypes), one being predominant. However in one case, we found a high nucleotide divergence between haplotypes of the same isolate. Comparison of these haplotypes with those from other isolates suggests that some CTV isolates could have arisen as result of a mixed infection of two divergent isolates.

Superantigens - powerful modifiers of the immune system

Superantigens are powerful microbial toxins that activate the immune system by binding to class II major histocompatibility complex and T-cell receptor molecules. They cause a number of diseases characterized by fever and shock and are important virulence factors for two human commensal organisms, Staphylococcus aureus and Streptococcus pyogenes, as well as for some viruses. Their mode of action and variation around the common theme of over-stimulating T cells, provides a rich insight into the constant battle between microbes and the immune system.

Complete nucleotide sequence and analysis of the putative polyprotein of maize dwarf mosaic virus genomic RNA (Bulgarian isolate)

The complete nucleotide sequence of maize dwarf mosaic virus Bulgarian isolate (MDMV-Bg) was determined. The viral genome was 9515 nt and contained an open reading frame encoding 3042 amino acids, flanked by 3'- and 5'-UTRs of 139 and 250 nucleotides, respectively. MDMV-Bg was more conserved in the coding region (52.9%) than in the UTRs (45.8%) when compared to the 15 other potyviruses. Of ten putative gene products of MDMV-Bg, the P1 was the most variable protein (24.9%) while the NIb was the most conserved protein (67.3%). Several sequence variations were observed between MDMV-Bg and Johnson grass mosaic virus (JGMV), and more between MDMV-Bg and the dicot potyviruses. Phylogenetic analysis suggested that MDMV-Bg was the most closely related to JGMV.

[Influence of arsenic on proliferation and differentiation of rat bud cells in vitro]

The objective of this study was designed to evaluate the developmental toxicity of arsenic and its effect on embryonic chondrogenesis of Sprague-Dawley rat by using Flint's rat limb bud cell micromass cultrure system in vitro. The results revealed that arsenic inhibited markedly both proliferation and differentiation of rat limb bud cells in vitro and there was an obvious dose-response relationship. The concentrations of arsenic for IP50(dose of inhibiting proliferation by 50% of the control value) and ID50(dose of inhibiting differentiation by 50% of the control value) were 0.70 mg/L and 0.21 mg/L respectively. The ratio between IP50 and ID50 was 3.3. These parameters indicated that the influence of arsenic on differentiation of rat limb bud cells was stronger than on proliferation, and arsenic belonged to a strong teratogenic agent and a specific inhibitor. This study suggested that the specific inhibitory action of arsenic on limb bud cell differentiation did not result from the cytotoxicity, but would result from the teratogenic effects of arsenic.

[Localization of ferritin in placental villous tissue and its role in the maternal-fetal iron transport]

OBJECTIVE

To investigate the localization and quantity of ferritin in placental villous tissue and its implications.

METHODS

The localization of ferritin in placental villous tissue at different gestation period was assayed by immunocytochemistry. The quantity of ferritin in placental villous tissue was determined with radioimmunoassay.

RESULTS

Ferritin was localized in all layers of the trophoblast, especially in the surface of the syncytiotrophoblast and basal membrane. The quantity of ferritin in placental villous tissue was increased with gestation progress and decreased in pregnant women with IDA.

CONCLUSIONS

Ferritin may be the important carrier of transplacental iron transport, and its receptor plays a crucial role in the course. The placental iron transport varied with gestation progress and iron nutritional status of the mother.

[Expression of ferritin receptor on placental microvillous membrane and its role in maternal-fetal iron transport]

OBJECTIVE

In order to investigate the expression of ferritin receptor (FnR) on human placental microvillous membrane in mid-pregnancy and its implication.

METHODS

Radioligand binding assay was used, with horse spleen 125I-apo-ferritin as radioligand.

RESULTS

The FnR expression in normal placental microvillous membrane in mid-pregnancy was (9.63 +/- 4.72) x 10(12) sites/mg pro, similar to that in normal placental of term delivery,and the dissociation constants (Kd) between them had also no significant difference: Competitive binding assay indicated that the receptor bound basic ferritin with higher affinity than acidic one.

CONCLUSIONS

The expression of FnR in mid-pregnancy almost come to mature level; The FnR on placenta might be involved in maternal-fetal iron transport, transfering iron from mother to fetal.

Metabolism of acetaminophen and phenacetin by isolated rat hepatocytes. A system in which the spatial organization inherent in the liver is disrupted

The kinetics of sulfation of 3H-acetaminophen (preformed metabolite) and 14C-acetaminophen (generated metabolite) during the parallel incubations of tracer concentrations of 3H-acetaminophen and 14C-phenacetin in (a) isolated rat hepatocytes and (b) rat 9000g supernatant fractions from liver and from isolated hepatocytes were compared to results obtained from rat liver perfusion studies (Pang and Gillette, J. Pharmacol. Exp. Ther. 207, 178-194, 1978; Pang and Terrell, J. Pharmacol. Exp. Ther. 216, 339-346, 1981). The isolated rat hepatocytes and the subcellular fractions represent in vitro systems whose metabolic activities are apparently homogeneous and contrast the in situ rat liver perfusion system where differential distribution of drug metabolizing activities exists within the rigid architecture of the intact organ. The ratio of sulfation (intrinsic clearance = 23.8 ml/min/liver) to O-deethylation (intrinsic clearance = 11.7 ml/min/liver) activities within these isolated hepatocytes (2.2-2.7) and subcellular fractions (3.72) were similar, but were reversed in the perfused liver preparation (0.2-0.5) depending on the model of hepatic drug clearance used for the calculation. Moreover, the sulfation to O-deethylation activity in the isolated rat hepatocyte system was independent of cell concentration (3.8 to 11 X 10(8) cells/ml) or the method of isolation of hepatocytes (by normal digestion or retrograde digestion). The reason for the reversal of lower O-deethylation activity in the subcellular and cellular systems remains unknown.(ABSTRACT TRUNCATED AT 250 WORDS)

Kinetics of procainamide N-acetylation in the rat in vivo and in the perfused rat liver preparation

The kinetics of procainamide N-acetylation were studied in the rat in vivo and in vitro. For the in vivo studies, first order kinetics for procainamide and N-acetylprocainamide were found among their respective iv doses of 20, 50, and 70 mg/kg, and 10, 20, and 30 mg/kg. The fraction of total body clearance of procainamide that forms N-acetylprocainamide was found to be 0.22, and very insignificant sequential elimination of N-acetylprocainamide occurred during its formation. By contrast, results from once-through liver perfusion indicated that the steady state hepatic extraction ratio of procainamide was highly dependent on the steady state input concentration delivered under constant hepatic blood flow (10 ml/min). The rate of N-acetylation, however, was a constant percentage of the rate of presentation of procainamide at less than or equal to 80 micrograms/min among the preparations and became apparently saturated at higher rates of input of procainamide. Interestingly, the rate of N-acetylation accounted for an increasing proportion of the rate of loss of procainamide at greater than 80 micrograms/min, and suggested that alternate metabolic routes of procainamide are more easily saturable than N-acetylation. The comparative in vivo and in vitro data suggested that a region of nonlinearity existed during the early periods immediately following iv injection of procainamide into the rat in vivo. Because of rapid distribution, the region of nonlinearity was transient, and was not reflected by area under the curve measurements, which is a time-averaged parameter. Total body clearance, which bears a reciprocal relationship with the area under the curve, hence remained constant and was dose-invariant. The trend of nonlinearity may be more evident on chronic dosing of the drug when accumulation sets in.