Outcomes of the transformation of follicular lymphoma to diffuse large B-cell lymphoma in the rituximab era: A population-based study.

BACKGROUND: Histological transformation (HT) to diffuse large B-cell lymphoma (DLBCL) is a common complication of follicular lymphoma (FL) and is usually associated with a dismal outcome. However, the survival rate of these patients has improved over the last 20 years with the introduction of rituximab. This study aimed to access the outcome of transformation to DLBCL (t-DLBCL) from FL in a retrospective series that began after the widespread use of rituximab use. In addition, we also compared survival between t-DLBCL and primary DLBCL (p-DLBCL) in the same timeframe. METHODS: We utilized the Surveillance, Epidemiology, and End Results (SEER) database to identify patients with primary FL and patients with p-DLBCL between 2000 and 2020. Patients who had a subsequent diagnosis of DLBCL at least 2 months after FL diagnosis were identified as t-DLBCL. RESULTS: Finally, we identified 50,332 FL and 95,933 p-DLBCL. With a median follow-up of 119 months, 1631 patients developed t-DLBCL. The median time from FL diagnosis to t-DLBCL was approximately 4 years. The post-transformation survival (PTS) rate at 5 years was 49.6%, with a median PTS of 56 months. Older age, advanced stage, and early transformation were associated with worse PTS. Furthermore, t-DLBCL receiving chemotherapy or combined modality as initial therapy before HT was also associated with worse PTS, while the result was inverse when taking the impact of initial management strategy at HT into account. Taking t-DLBCL and p-DLBCL as a whole, comparable survival was observed between p-DLBCL and t-DLBCL receiving radiation or watch-and-wait as initial therapy prior to HT. CONCLUSION: The outcome of t-DLBCL in the rituximab era was better than historical series before the rituximab era. Due to the good prognosis, we did not recommend autologous stem cell transplantation for t-DLBCL receiving watch-and-wait or radiation as initial therapy before HT.

Incidence and risk factors for febrile neutropenia of patients with diffuse large B-cell lymphoma receiving R-CHOP-21 in China.

OBJECTIVE: Febrile neutropenia (FN) is a serious complication of patients with diffuse large B-cell lymphoma (DLBCL) receiving R-CHOP-21. The prophylactic use of granulocyte colony-stimulating factors (G-CSFs) can significantly reduce the risk of FN. International guidelines recommend G-CSFs for patients receiving chemotherapy with FN risk of 20% or 10 to 20% with defined risk factors. However, there are few studies on the incidence and risk factors of FN in patients with DLBCL receiving R-CHOP-21, especially in patients without primary G-CSF prophylaxis. METHODS: We conducted a retrospective analysis for the clinical data of 103 patients with DLBCL who underwent first R-CHOP-21 without primary G-CSF prophylaxis. The objective of the assessment was the incidence and risk factors of FN after the first chemotherapy cycle. RESULTS: After the first chemotherapy cycle, the incidence of FN was 20.4%. Multivariate analysis showed that age ≥ 65 years, bone marrow involvement, albumin < 35 g/L, and average relative dose intensity ≥ 80% were independent risk factors for FN. According to risk factors, we created a risk score system. The incidence of FN in the low-, intermediate- and high-risk groups was 5.6%, 17.2%, and 61.9%, respectively. CONCLUSION: Our data indicated that R-CHOP-21 itself is associated with a high-risk regiment for FN. We recommend that intermediate/high-risk patients should actively consider primary G-CSF prophylaxis to reduce the incidence of FN after chemotherapy.

Case report: First report of haploidentical allogeneic hematopoietic stem cell transplantation from donors with mild alpha-thalassemia for acute leukemia.

For acute leukemia (AL) with adverse prognostic factors, allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the standard care option after the first complete remission. Meanwhile, as the success of haploidentical HSCT (haplo-HSCT), haploidentical donors (HIDs) become a reliable choice. However, there have been no reports on haplo-HSCT from HIDs with mild alpha(α)-thalassemia for AL yet. In the present report, we first describe two cases of successful haplo-HSCT from HIDs with mild α-thalassemia for AL.

[Clinical Characteristics and Risk Factors of Invasive Fungal Infections in Acute Leukemia Patients in Tropical Regions].

OBJECTIVE: To analyze the clinical characteristics and risk factors of invasive fungal infection (IFI) occurenced in patients with acute leukemia (AL) during treatment in tropical regions. METHODS: The clinical data of 68 AL patients admitted to the Hainan Hospital of PLA General Hospital from April 2012 to April 2019 was retrospectively analyzed. Logistic regression analysis was used to analyze the factors affecting the occurrence of IFI in AL patients. RESULTS: Among the 68 patients, 44 were acute myeloid leukemia, 24 were acute lymphoblastic leukemia, 39 were male, 29 were female and the median age was 41(13-75) years old. The 68 patients received 242 times of chemotherapy or hematopoietic stem cell transplantation(HSCT), including 73 times of initial chemotherapy or inducting chemotherapy after recurrence, 14 times of HSCT, 155 times of consolidating chemotherapy. Patients received 152 times of anti-fungal prophylaxis, including 77 times of primary anti-fungal prophylaxis and 75 times of secondary anti-fungal prophylaxis. Finally, the incidence of IFI was 31 times, including 24 times of probable diagnosis, 7 times of proven diagnosis, and the total incidence of IFI was 12.8%(31/242), the incidence of IFI in inducting chemotherapy was 24.66%(18/73), the incidence of IFI in HSCT patients was 28.57% (4/14), the incidence of IFI in consolidating chemotherapy was 5.80% (9/155). Multivariate analysis showed that inducting chemotherapy or HSCT, the time of agranulocytosis ≥7 days, risk stratification of high risk were the independent risk factors for IFI in AL patients during treatment in tropical regions. CONCLUSION: The incidence of IFI in patients with AL in the tropics regions is significantly higher than that in other regions at homeland and abroad. Anti-fungal prophylaxis should be given to the patients with AL who have the high risk factors of inducting chemotherapy or HSCT, time of agranulocytosis ≥7 days and risk stratification of high risk.

The effect of the detection of minimal residual disease for the prognosis and the choice of post-remission therapy of intermediate-risk acute myeloid leukemia without FLT3-ITD, NPM1 and biallelic CEBPA mutations.

BACKGROUND: Intermediate-risk acute myeloid leukemia (IR-AML) without FLT3-ITD, NPM1 and biallelic CEBPA mutations (here referred to as NPM1mut-negCEBPAdm-negFLT3-ITDneg AML) is a clinically heterogeneous disease. The optimal post-remission therapy (PRT) is unclear for patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML who achieved first complete response (CR1). This study aims to explore clinical and molecular factors that can help determine the prognosis of those patients and their choice of PRT. METHODS: We retrospectively analyzed 28 patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML who received induction chemotherapy and achieved CR1. For PRT, 17 patients received post-remission chemotherapy (PR-CT) and 11 patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT). RESULTS: For patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML, multivariate analysis indicated that allo-HSCT and negative minimal residual disease (MRDneg) before PRT were favorable prognostic factors of overall survival (OS) (allo-HSCT, P = 0.002; MRDneg, P = 0.018); whereas relapse was an adverse prognostic factor of OS (P = 0.003). Log-rank analysis showed that allo-HSCT significantly improved their OS and RFS compared with PR-CT (OS, P < 0.001; RFS, P = 001). Otherwise, allo-HSCT improved the OS and RFS of patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML, whether they obtained MRDpos or MRDneg before PRT (OS: MRDneg, P = 0.036; MRDpos, P = 0.012; RFS: MRDneg, P = 0.047; MRDpos, P = 0.030). CONCLUSION: For patients with NPM1mut-negCEBPAdm-negFLT3-ITDneg AML, MRDneg before PRT and allo-HSCT were favorable prognostic factors of OS. Whether they obtain MRDneg or not, allo-HSCT is the preferred PRT.

[Single Center Analysis of Bloodstream Infection Clinical Characteristics and Prognosis in Patients with Hematological Malignancies in the Tropics].

OBJECTIVE: To analyze the characteristics, prognosis and risk factors of bloodstream infection in patients with hematological malignancies in the tropics, so as to provide evidence for the prevention and treatment of bloodstream infection. METHODS: The clinical features, blood culture results and prognosis of patients with bloodstream infection in patients with hematological malignancies admitted to Hainan Hospital of PLA General Hospital were retrospectively studied. RESULTS: The most common primary infection site of the 81 patients with hematological malignancies was lung (46.91%), followed by PICC (11.11%). The detection rate of Gram-positive bacteria and Gram-negative bacteria in the blood culture was 60.98% and 30.02%, respectively. Coagulase-negative staphylococci was the most common Gram-positive bacteria resulting in bloodstream infection in our study. Of the Gram-negatives, Klebsiella pneumoniae (34.38%) was predominant, followed by Escherichia coli (18.75%) and Pseudomonas aeruginosa (18.75%). Gram-positive bacteria was highly sensitive (100%) to vancomycin, linezolid and tigecycline. Study showed that Gram-negative bacteria had low sensitive to quinolones, in particular, the resistance rate of Escherichia coli to quinolones was as high as 83.33%. In terms of overall survival (OS), the 30-days OS of patients with Gram-negative and Gram-positive septicemia was 77.42% and 92.00%, respectively. There was no statistically significant difference between the two groups. Multivariate analysis revealed that septic shock (P=0.001, RR=269.27) was an independent risk factor for 30-day mortality, and remission status (P=0.027, RR=0.114) was an independent predictor of a favourable outcome of bloodstream infection in patients with hematological malignancies. CONCLUSION: Gram-positive bacteria are the main pathogens causing bloodstream infections in patients with hematological malignancies in the tropics. Improving the care of PICC is an important measure to reduce the incidence of bloodstream infection in patients with hematological malignancies in the tropics. A correct treatment relieving disease and effective prevention and treatment of septic shock can reduce mortality of patients with bloodstream infection in patients with hematological malignancies in the tropics.

Potential effect of epigenetic drugs in the treatment of multiple-site extramedullary plasmacytoma involving the respiratory system: a case report and review of the literature.

We report the case of a 23-year-old man with a medical history of idiopathic thrombocytopenic purpura (ITP) and newly diagnosed with the Epstein-Barr virus (EBV)-positive multiple-site extramedullary plasmacytoma (EMP), which involves the respiratory system. The patient was referred to our hospital because of progressive nasal congestion and nasal mass. Nasopharyngoscopy and bronchoscopy were performed. The biopsy pathological hematoxylin and eosin (HE) staining indicated plasma cell myeloma, and further immunohistochemistry CD99(+), CD79a(+), CD38(+), MUM-1(+), and Lambda(+) confirmed the diagnosis. The patient's bone marrow was normal, and hypercalcemia, renal insufficiency, anemia, evident bone lesions were not observed. Serum immunoglobulin quantification, serum protein electrophoresis, and blood and urine light chain quantification were all within the normal range. The serum immunofixation electrophoresis was negative, and the serum-free light chain was normal. These results could rule out multiple myeloma (MM) and prove to be EMP involving the nasal cavity, main bronchus, lung, and left hip. No desired effect was achieved after receiving PAD (bortezomib, adriamycin, and dexamethasone) and VRD (bortezomib, lenalidomide, and dexamethasone) treatments. Even if the tumor was remarkably relieved after receiving the 2-course CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) regimen, secondary resistance to CHOP unfortunately occurred in this case. We attempted to apply epigenetic therapy in the treatment of refractory multiple EMP. Although no complete remission (CR) was achieved, the maximum standard uptake value (SUVmax) in tumor lesions was significantly lower than before, and the patient's symptoms significantly improved. The patient tolerated decitabine and chidamide. We speculated that epigenetic drugs have potential effect in the treatment of multiple-site EMP.

[Clinical Characteristics and Prognosis of Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma].

OBJECTIVE: To investigate the clinical characteristics of relapsed or refractory (R/R) diffuse large B-cell lymphoma (DLBCL) and the factors affecting overall survival (OS) time. METHODS: The clinical data of 14 R/R DLBCL patients admitted to the Hainan Hospital of Chinese PLA General Hospital from April 2012 to March 2019 were analyzed retrospectively and the overall response rate (ORR) after the end of different treatments was estimated. Kaplan-Meier method was used to describe the survival curve, and Log-rank test was used to compare whether different survival curves showed statistically different. RESULTS: There were 8 males and 6 females with a median age of 51 (26-75) years old and the median course of treatment before R/R was 7 (4-13). Finally, 11 patients achieved remission, 6 patients of which showed complete remission, and 5 patients showed partial remission, with the median ORR duration at 2.5 (0-51) months. All patients in the group of ibrutinib combined with second-line chemotherapy achieved remission (4/4), it was equivalent to the high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (HDC-AHSCT) group (4/4), which was significantly higher than that of the other second-line group (3/6). The median OS time of patients was 17 (6-76) months. The survival of patients receiving ibrutinib combined with second-line chemotherapy and HDC-AHSCT was significantly better than that of patients not receiving ibrutinib combined with second-line chemotherapy and HDC-AHSCT. Normal lactate dehydrogenase, IPI score＜3 at diagnosis, and CR/PR after treatment could improve the survival time of patients. CONCLUSION: The duration of remission for R/R DLBCL patients is short and the prognosis is very poor. The survival time of patients with high level of lactate dehydrogenase, IPI score≥3 at diagnosis and SD/PD after treatment is significantly shortened. Ibrutinib combined second-line chemotherapy and HDC-AHSCT can improve the efficacy and survival of R/R DLBCL patients.

[Clinical Analysis of Allogeneic Hematopoietic Stem Cell Transplantation for Treatment of 12 Patients with Acute Leukemia in Tropical Area].

OBJECTIVE: To analyze the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for treatment of acute leukemia in the tropical area. METHODS: Twelve acute leukemia patients who were underwent allo-HSCT from April 2013 to November 2018 in Hainan Hospital of Chinese PLA General Hospital were selected, including 5 cases of acute lymphoblastic leukemia (ALL) and 7 case of acute myeloid leukemia (AML). Three cases received HLA matched sibling hematopoietic stem cell transplantation, 8 cases received haploidentical hematopoietic stem cell transplantation, 1 cases received partially mismatched unrelated hematopoietic stem cell transplantation. Pretreatment regimen: 9 cases received modified BU/CY+ATG pretreatment regimen, 3 cases received BU/CY pretreatment regimen. Graft-versus-host disease (GVHD) prevention regimen: all patients received cyclosporine A, mycophenolate mofetil combined with short-term methotrexate regimen. The clinical efficacy of allo-HSCT in treatment of acute leukemia in the tropical area was analyzed by detecting hematopoietic reconstitution, GVHD, infection, relapse and survival after transplantation. RESULTS: All the 12 patients achieved granulocyte reconstruction and megakaryocyte reconstruction. The median time of granulocyte reconstruction was 11.5 (6-14) days, and the median time of megakaryocytic reconstruction was 12.5 (10-22) days. Within 100 days after transplantation, the acute GVHD occurved in 8 cases, including 6 cases of Ⅱ-Ⅳ degree acute GVHD and 2 cases of Ⅲ-Ⅳ degree acute GVHD, 11 cases survived more than 100 days after transplantation, and the chronic GVHD occurred in 1 case, which was mildly limited. Pulmonary infection occurred in 7 cases, cytomegaloviremia occurred in 6 cases, EB viremia occurred in 6 cases, and hemorrhagic cystitis occurred in 5 cases. 2 cases relapsed and eventually died, and the remaining 10 patients survived without disease until the date of follow-up. The median follow-up time was 4 (1-68) months, 83.3% (10/12) survived without disease, and 16.7% (2/12) relapsed. CONCLUSION: Allo-HSCT is an effective method for the treatment of acute leukemia in adults. Leukemia patients should be transplanted as soon as possible after remission. The incidence of pulmonary fungal infection in transplanted patients in tropics is high, therefore the prevention and treatment of fungal infection should be strengthened.

[Clinical Characteristics and Prognosis of U2AF1 Mutation in Patients with Acute Myeloid Leukemia].

OBJECTIVE: To investigate the incidence, clinical features of U2AF1 gene mutation in patients with acute myeloid leukemia(AML) and its effect of prognosis. METHODS: A total of 161 patients with AML were enrolled. The second-generation sequencing method was used to detect U2AF1 gene mutation, and the relationship between U2AF1 mutation and clinical features, prognosis was analyzed. RESULTS: The mutation rate of U2AF1 gene in 161 AML patients was 3.73%. The counts of peripheral blood leukocytes and platelets in the U2AF1 gene mutation group were lower than those in the wild type group. The complete response rate of U2AF1 gene mutation group was 66.67%, while that in wild type group was 55.48%, which shows no significant difference between the two groups (P=0.70). The median EFS of wild type group and the mutant group was not reached and reached to 133 days, respectively (P=0.03), while the medium OS in two groups was not reached and reached to 210 days (P=0.01). CONCLUSION: The AML patients with U2AF1 mutation positive have a poor prognosis as compared with the wild type group, which may be a poor prognostic factor for acute myeloid leukemia.

Arrestin-biased AT1R agonism induces acute catecholamine secretion through TRPC3 coupling.

Acute hormone secretion triggered by G protein-coupled receptor (GPCR) activation underlies many fundamental physiological processes. GPCR signalling is negatively regulated by ß-arrestins, adaptor molecules that also activate different intracellular signalling pathways. Here we reveal that TRV120027, a ß-arrestin-1-biased agonist of the angiotensin II receptor type 1 (AT1R), stimulates acute catecholamine secretion through coupling with the transient receptor potential cation channel subfamily C 3 (TRPC3). We show that TRV120027 promotes the recruitment of TRPC3 or phosphoinositide-specific phospholipase C (PLCγ) to the AT1R-ß-arrestin-1 signalling complex. Replacing the C-terminal region of ß-arrestin-1 with its counterpart on ß-arrestin-2 or using a specific TAT-P1 peptide to block the interaction between ß-arrestin-1 and PLCγ abolishes TRV120027-induced TRPC3 activation. Taken together, our results show that the GPCR-arrestin complex initiates non-desensitized signalling at the plasma membrane by coupling with ion channels. This fast communication pathway might be a common mechanism of several cellular processes.

Adaptive Activation of a Stress Response Pathway Improves Learning and Memory Through Gs and ß-Arrestin-1-Regulated Lactate Metabolism.

BACKGROUND: Stress is a conserved physiological response in mammals. Whereas moderate stress strengthens memory to improve reactions to previously experienced difficult situations, too much stress is harmful. METHODS: We used specific ß-adrenergic agonists, as well as ß2-adrenergic receptor (ß2AR) and arrestin knockout models, to study the effects of adaptive ß2AR activation on cognitive function using Morris water maze and object recognition experiments. We used molecular and cell biological approaches to elucidate the signaling subnetworks. RESULTS: We observed that the duration of the adaptive ß2AR activation determines its consequences on learning and memory. Short-term formoterol treatment, for 3 to 5 days, improved cognitive function; however, prolonged ß2AR activation, for more than 6 days, produced harmful effects. We identified the activation of several signaling networks downstream of ß2AR, as well as an essential role for arrestin and lactate metabolism in promoting cognitive ability. Whereas Gs-protein kinase A-cyclic adenosine monophosphate response element binding protein signaling modulated monocarboxylate transporter 1 expression, ß-arrestin-1 controlled expression levels of monocarboxylate transporter 4 and lactate dehydrogenase A through the formation of a ß-arrestin-1/phospho-mitogen-activated protein kinase/hypoxia-inducible factor-1α ternary complex to upregulate lactate metabolism in astrocyte-derived U251 cells. Conversely, long-term treatment with formoterol led to the desensitization of ß2ARs, which was responsible for its decreased beneficial effects. CONCLUSIONS: Our results not only revealed that ß-arrestin-1 regulated lactate metabolism to contribute to ß2AR functions in improved memory formation, but also indicated that the appropriate management of one specific stress pathway, such as through the clinical drug formoterol, may exert beneficial effects on cognitive abilities.

Non-proton ligand-sensing domain of acid-sensing ion channel 3 is required for itch sensation.

Itch, the unpleasant sensation that evokes a desire to scratch, accompanies numerous skin and nervous system disorders. However, the molecular mechanisms of itch are unclear. Acid-sensing ion channel 3 (ASIC3) is a sensor of acidic and primary inflammatory pain. The whole-cell patch clamp technique was used to determine the effect of chloroquine (CQ) on ASICs currents in primary sensory neurons or the Chinese hamster ovary cells transfected with rat ASIC1a or ASIC3. Site-directed mutagenesis of plasmid was performed. Scratching behavior was evaluated by measuring the number of bouts during 30 min after injection. CQ, an anti-malarial drug defined as a histamine-independent pruritogen, selectively enhanced the sustained phase of ASIC3 current in a concentration-dependent manner either in ASIC3-transfected Chinese hamster ovary cells or in primary cultured rat dorsal root ganglion neurons. Further studies revealed that the effect of CQ on ASIC3 channels depends on the newly identified non-proton ligand-sensing domain. Importantly, CQ-evoked scratching behavior was largely alleviated by APETx2, a selective ASIC3 channel blocker. Like CQ, other compounds such as amiloride, 2-guanidine-4-methylquinazoline and neuropeptide FF, which have been previously reported to be non-proton ligands that activate ASIC3, undoubtedly evoked the scratching response. In conclusion, ASIC3, a proton-gated ion channel critical for pain sensation, also functions as an essential component of itch transduction.

Crystal Structure and Substrate Specificity of PTPN12.

PTPN12 is an important tumor suppressor that plays critical roles in various physiological processes. However, the molecular basis underlying the substrate specificity of PTPN12 remains uncertain. Here, enzymological and crystallographic studies have enabled us to identify two distinct structural features that are crucial determinants of PTPN12 substrate specificity: the pY+1 site binding pocket and specific basic charged residues along its surface loops. Key structurally plastic regions and specific residues in PTPN12 enabled recognition of different HER2 phosphorylation sites and regulated specific PTPN12 functions. In addition, the structure of PTPN12 revealed a CDK2 phosphorylation site in a specific PTPN12 loop. Taken together, our results not only provide the working mechanisms of PTPN12 for desphosphorylation of its substrates but will also help in designing specific inhibitors of PTPN12.

Different downstream signalling of CCK1 receptors regulates distinct functions of CCK in pancreatic beta cells.

BACKGROUND AND PURPOSE: Cholecystokinin (CCK) is secreted by intestinal I cells and regulates important metabolic functions. In pancreatic islets, CCK controls beta cell functions primarily through CCK1 receptors, but the signalling pathways downstream of these receptors in pancreatic beta cells are not well defined. EXPERIMENTAL APPROACH: Apoptosis in pancreatic beta cell apoptosis was evaluated using Hoechst-33342 staining, TUNEL assays and Annexin-V-FITC/PI staining. Insulin secretion and second messenger production were monitored using ELISAs. Protein and phospho-protein levels were determined by Western blotting. A glucose tolerance test was carried out to examine the functions of CCK-8s in streptozotocin-induced diabetic mice. KEY RESULTS: The sulfated carboxy-terminal octapeptide CCK26-33 amide (CCK-8s) activated CCK1 receptors and induced accumulation of both IP3 and cAMP. Whereas Gq -PLC-IP3 signalling was required for the CCK-8s-induced insulin secretion under low-glucose conditions, Gs -PKA/Epac signalling contributed more strongly to the CCK-8s-mediated insulin secretion in high-glucose conditions. CCK-8s also promoted formation of the CCK1 receptor/ß-arrestin-1 complex in pancreatic beta cells. Using ß-arrestin-1 knockout mice, we demonstrated that ß-arrestin-1 is a key mediator of both CCK-8s-mediated insulin secretion and of its the protective effect against apoptosis in pancreatic beta cells. The anti-apoptotic effects of ß-arrestin-1 occurred through cytoplasmic late-phase ERK activation, which activates the 90-kDa ribosomal S6 kinase-phospho-Bcl-2-family protein pathway. CONCLUSIONS AND IMPLICATIONS: Knowledge of different CCK1 receptor-activated downstream signalling pathways in the regulation of distinct functions of pancreatic beta cells could be used to identify biased CCK1 receptor ligands for the development of new anti-diabetic drugs.

A stress response pathway in mice upregulates somatostatin level and transcription in pancreatic delta cells through Gs and ß-arrestin 1.

AIMS/HYPOTHESIS: Somatostatin secretion from islet delta cells plays an important role in regulating islet function and is tightly controlled by environmental changes. Activation of the adrenergic system promoted somatostatin secretion from islet delta cells; however, the role of the adrenergic system in regulating somatostatin content and transcription has not been defined. An imbalance between the somatostatin content and its secretion may cause dysfunctions in the islet delta cells. We have investigated the role of the adrenergic system in the modulation of somatostatin content and transcription in pancreatic delta cells and the detailed underlying mechanisms of this regulation. METHODS: The stress hormone adrenaline (epinephrine), specific adrenergic agonists or specific adrenergic antagonists were applied to islets from either wild-type or specific adrenergic receptor knockout mice and pancreatic delta cell lines to investigate their effects on somatostatin content and transcription. The GloSensor assay, quantitative real-time PCR, western blots and the dual luciferase assay were used to monitor the cAMP level, somatostatin expression, activations of kinases and transcriptional factors. Arrb1 knockout mice, specific Creb or Pax6 mutations and specific kinase inhibitors were used to dissect the signalling pathway. RESULTS: Adrenaline and isoprenaline increased somatostatin content and transcription through the activation of ß1-/ß2-adrenergic receptors (ß1-/ß2ARs). The somatostatin content in ß1AR(-/-) /ß2AR(-/-) (Adrb1/Adrb2 knockout) mice was 50% lower than in ß1AR(+/+)/ß2AR (+/+) mice. Two parallel signalling pathways, Gs-cAMP-protein kinase A (PKA)-cAMP response element binding protein (CREB) and ß-arrestin 1-extracellular signal-related kinase (ERK)-paired box protein 6 (PAX6), cooperatively regulated isoprenaline-induced somatostatin transcription. CONCLUSIONS/INTERPRETATION: A stress pathway increased somatostatin content and transcription through ß-adrenergic agonism. ß-Arrestin1, ERK and PAX6 are important pancreatic delta cell regulators in addition to cAMP, PKA and CREB. Dysfunction of ß-adrenergic agonism may impair pancreatic delta cell function.

In vitro interactions between aspirin and amphotericin B against planktonic cells and biofilm cells of Candida albicans and C. parapsilosis.

The increase in drug resistance and invasion caused by biofilm formation brings enormous challenges to the management of Candida infection. Aspirin's antibiofilm activity in vitro was discovered recently. The spectrophotometric method and the XTT {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide} reduction assay used for data generation make it possible to evaluate fungal biofilm growth accurately. The combined use of the most commonly used methods, the fractional inhibitory concentration index (FICI) and a newly developed method, the ΔE model, which uses the concentration-effect relationship over the whole concentration range instead of using the MIC index alone, makes the interpretation of results more reliable. As an attractive tool for studying the pharmacodynamics of antimicrobial agents, time-kill curves can provide detailed information about antimicrobial efficacy as a function of both time and concentration. In the present study, in vitro interactions between aspirin (acetylsalicylic acid [ASA]) and amphotericin B (AMB) against planktonic cells and biofilm cells of Candida albicans and C. parapsilosis were evaluated by the checkerboard microdilution method and the time-kill test. Synergistic and indifferent effects were found for the combination of ASA and AMB against planktonic cells, while strong synergy was found against biofilm cells analyzed by FICI. The ΔE model gave more consistent results with FICI. The positive interactions in concentration were also confirmed by the time-kill test. Moreover, this approach also revealed the pharmacodynamics changes of ASA and synergistic action on time. Our findings suggest a potential clinical use for combination therapy with ASA and AMB to augment activity against biofilm-associated infections.