Profile of reticulated platelets in the early, subacute and late phases after transient ischemic attack or ischemic stroke.

Information regarding the profile of reticulated platelets (RP) in ischemic cerebrovascular disease (CVD) patients is limited. Data from two prospective, observational, case-control studies were combined to compare the %RP using whole blood flow cytometry in patients ≤ 4 weeks of TIA/stroke onset (baseline, N = 210), and 14 ±7 days (14d, N = 182) and ≥ 90 days (90d, N = 145) after starting or changing antiplatelet therapy with healthy controls (N = 34). There were no differences in median %RP between the overall CVD patient population at baseline or 14d vs. controls (P ≥ 0.2). However, the median %RP was significantly higher in CVD patients overall at 90d (P = .036), and in the subgroup of patients with "lacunar" TIA/ischemic stroke at baseline (P = .04) and at 90d (P = .01), but not at 14d (P = .06) vs. controls. There were no significant differences in the median %RP between other TIA/stroke subgroups and controls (P ≥ 0.05). Elevated circulating reticulated platelets, as a marker of increased platelet production/turnover, may occur following an ischemic event in a well-phenotyped TIA/ischemic stroke population overall, but may precede symptom onset at least in the subgroup with small vessel occlusion. These data improve our understanding of the profile of reticulated platelets in CVD patients.

Paediatric cataract surgery in Hospital Kuala Lumpur - A 5-year review of visual outcomes.

INTRODUCTION: Paediatric cataract surgery is challenging with reported post-operative visual acuity (VA) of 0.3LogMar or better varying between 33% to 68% of patients. OBJECTIVE: The aim is to document the post-operative refraction, VA and complications of non-traumatic pediatric cataract surgery performed in a tertiary referral center in Malaysia. METHODOLOGY: This retrospective study reviewed case notes of all consecutive patients aged 12 years and below who underwent cataract surgery from January 2010 to December 2015. Patients were recruited if they had a minimum of six months post-operative follow-up. Exclusion criteria included traumatic cataract, central nervous system abnormalities, incomplete medical records or pre-existing ocular pathology. Subjects were divided into two groups based on refraction at one month. Subjects with refraction within 1- dioptre of the targeted spherical equivalent were in the success group and the rest were in the failure group. RESULTS: A total of 111 subjects were recruited (65 subjects in success group and 46 subjects in the failure group). Mean age at surgery was 33.14 (SD: 33.47) months. The success group had significantly longer axial length (p:0.0045, CI: 0.566-0.994, OR: 0.750). At final review, 44.1%(49/111) subjects had visual acuity of 0.3LogMar or better. The success group had better final mean VA in comparison to the failure group (p:0.034, CI:1.079-7.224, OR: 2.791). CONCLUSION: The outcome of non-traumatic paediatric cataract surgery was acceptable with 58.6% achieved targeted refractive correction at 1-month post-operative period. Longer axial length was associated with better refractive outcome. Capsule related complications was the most common intra-operative complication.

Sequential chemotherapy/radiotherapy was comparable with concurrent chemoradiotherapy for stage I/II NK/T-cell lymphoma.

Background: In stage I/II natural killer (NK)/T-cell lymphoma, concurrent chemoradiotherapy (CCRT) had previously been shown to result in superior outcome compared with anthracycline-containing regimens, which have since been considered ineffective. The role of CCRT in comparison with approaches employing nonanthracycline-containing chemotherapy (CT) and sequential radiotherapy (RT) in such patients remains to be defined. Patients and methods: Three hundred and three untreated patients (207 men, 96 women; median age: 51, 18-86 years) with stage I/II NK/T-cell lymphoma who had received nonanthracycline-containing regimens were collected from an international consortium and retrospectively analyzed. Treatment included single modality (CT and RT), sequential modalities (CT + RT; RT + CT) and concurrent modalities (CCRT; CCRT + CT). The impact of clinicopathologic parameters and types of treatment on complete response (CR) rate, progression-free-survival (PFS) and overall-survival (OS) was evaluated. Results: For CR, stage (P = 0.027), prognostic index for NK/T-cell lymphoma (PINK) (P = 0.026) and types of initial treatment (P = 0.011) were significant prognostic factors on multivariate analysis. On Cox regression analysis, ECOG performance score (P = 0.021) and PINK-EBV DNA (PINK-E) (P = 0.002) significantly impacted on PFS; whereas ECOG performance score (P = 0.008) and stage (P < 0.001) significantly impacted on OS. For comparing CCRT ± CT and sequential CT + RT, CCRT ± CT patients (n = 190) were similar to sequential CT + RT patients (n = 54) in all evaluated clinicopathologic parameters except two significantly superior features (higher proportion of undetectable circulating EBV DNA on diagnosis and lower PINK-E scores). Despite more favorable pre-treatment characteristics, CCRT ± CT patients had CR rate, PFS and OS comparable with sequential CT + RT patients on multivariate and Cox regression analyses. Conclusions: In stage I/II NK/T-cell lymphomas, when effective chemotherapeutic regimens were used, CCRT and sequential CT + RT gave similar outcome.

Beyond first-line non-anthracycline-based chemotherapy for extranodal NK/T-cell lymphoma: clinical outcome and current perspectives on salvage therapy for patients after first relapse and progression of disease.

BACKGROUND: Current standard treatment, including non-anthracycline-based chemotherapy and optimal combining of radiotherapy, has dramatically improved outcomes of patients with extranodal natural killer/T-cell lymphoma (ENKTL) during the last decade. This study was conducted to investigate the clinical outcome of ENKTL patients with relapsed or progressive disease after initial current standard therapy. PATIENTS AND METHODS: We retrospectively reviewed patients diagnosed with ENKTL at six centers in four countries (China, France, Singapore, and South Korea) from 1997 to 2015 and analyzed 179 patients who had relapsed or progressed after initial current standard therapy. RESULTS: After a median follow-up of 58.6 months (range 27.9-89.2), the median second progression-free survival (PFS) was 4.1 months [95% confidence interval (CI) 3.04-5.16] and overall survival (OS) was 6.4 months (95% CI 4.36-8.51). Multivariate Cox-regression analysis revealed that elevated lactate dehydrogenase, multiple extranodal sites (≥2), and presence of B symptoms were associated with inferior OS (P < 0.05). OS and PFS were significantly different according to both prognostic index of natural killer lymphoma (PINK) and PINK-E (Epstein-Barr virus) models. Salvage chemotherapy with l-asparaginase (l-Asp)-based regimens showed a significantly better clinical benefit to response rate and PFS, although it did not lead to OS improvement. First use of l-Asp in the salvage setting and l-Asp rechallenge at least 6 months after initial treatment were the best candidates for salvage l-Asp containing chemotherapy. CONCLUSIONS: Most patients with relapsed or refractory ENKTL had poor prognosis with short survival. Further studies are warranted to determine the optimal treatment of patients with relapsed or refractory ENKTL.

Flavonoids from fruit and vegetables: a focus on cardiovascular risk factors.

Epidemiological studies suggest that high intakes of dietary flavonoids are associated with decreased cardiovascular disease mortality and risk factors. Less is known about the cardioprotective effects of flavonoids from fruit and vegetables. This review summarizes data from studies which examine the effects of commonly consumed fruit and vegetables on cardiovascular disease risk biomarkers in healthy volunteers or at-risk individuals. Although flavonoids from apples, berries, and onions appear to impact positively on blood pressure, vascular function, and serum lipid levels, further research is required to find out the optimal quantity and food matrix for conferring substantial clinical benefit. The benefits from citrus flavonoids are still inconclusive. Further robust, longer-term dietary intervention studies, with the inclusion of placebo or control arms, are required to improve the credibility of the findings and confirm current observations. An improved understanding of the impact of flavonoids from fruit and vegetables can help one make discerning food choices for optimal cardiovascular health.

Assessment of on-treatment platelet reactivity at high and low shear stress and platelet activation status after the addition of dipyridamole to aspirin in the early and late phases after TIA and ischaemic stroke.

BACKGROUND: Data are limited on the ability of dipyridamole to additionally inhibit platelet function/reactivity in ischaemic cerebrovascular disease (CVD) patients on aspirin. AIMS: To assess inhibition of platelet function/reactivity and platelet activation with dipyridamole in CVD. METHODS: This prospective, observational study assessed TIA/ischaemic stroke patients before (baseline; N = 60), at 14 ±7 days (14d, N = 39) and ≥ 90 days (90d, N = 31) after adding dipyridamole to aspirin. Platelet function/reactivity at high shear stress (PFA-100® C-ADP) and low shear stress (VerifyNow® P2Y12 and Multiplate® ADP assays), and platelet activation status (% expression of CD62P, CD63 and leucocyte-platelet complexes on whole blood flow cytometry) were quantified. 'Dipyridamole-high on-treatment platelet reactivity (HTPR)' was defined as failure to inhibit ADP-induced platelet aggregation +/- adhesion compared with the patient's baseline on aspirin monotherapy by more than twice the coefficient-of-variation of the assay after adding dipyridamole to aspirin. RESULTS: Dipyridamole-HTPR was identified in 71.4-75% of patients on PFA-100 C-ADP, 83.9-86.8% of patients on VerifyNow P2Y12, and 81.5-83.3% of patients on Multiplate ADP assays. There were no changes in CD62P/CD63 expression (P ≥ 0.18), or consistent changes in leucocyte-platelet complexes in CVD patients overall at 14d or 90d vs. baseline after commencing dipyridamole. Monocyte-platelet complexes increased in the patient subgroup with dipyridamole-HTPR at 14d and 90d on PFA-100, and at 14d on VerifyNow (P ≤ 0.04), but not in those without dipyridamole-HTPR. DISCUSSION: Additional antiplatelet effects of dipyridamole are detectable under high and low shear stress conditions with user-friendly platelet function/reactivity tests ex vivo. Increasing circulating monocyte-platelet complexes over time are associated with dipyridamole-HTPR.

Central nervous system (CNS) relapse in diffuse large B cell lymphoma (DLBCL): pre- and post-rituximab.

Central nervous system (CNS)-directed prophylactic intrathecal (IT) therapy is indicated in patients with Burkitt and acute lymphoblastic lymphoma. Its role in diffuse large B cell lymphoma (DLBCL), a heterogeneous subtype, is less well defined. While addition of rituximab to standard cyclophosphamide-hydroxydaunorubicin-oncovin-prednisone (CHOP) chemotherapy (R-CHOP) has improved the outcomes of DLBCL patients, its role in reducing CNS relapse is unclear. We aim to (1) evaluate the clinical risk factors predictive of CNS relapse, (2) the role of rituximab in influencing CNS relapse, and (3) role of intrathecal prophylaxis. Four hundred ninety-nine patients with DLBCL from 2000 to 2008 were included (CHOP 179 vs. R-CHOP 320). IT prophylaxis was administered to 82 patients based on our institution's guidelines. Baseline characteristics between CHOP- and R-CHOP-treated patients were similar. Although R-CHOP significantly increased the complete remission rate from 71% to 81% (P < 0.01), CNS relapse rates remained unchanged (R-CHOP 6% vs. CHOP 5.1%). On multivariate analysis, poor performance status (Eastern Cooperative Oncology Group >1; hazard ratio (HR) = 2.01, 95% confidence interval (CI) 1.29-3.14), failure to attain remission (non-complete response (CR) vs. CR: HR = 2.39, 95% CI = 1.03 to 5.51), testicular (HR = 6.67, 95% CI = 1.62 to 27.53), kidney (HR = 20.14, 95% CI = 5.23 to 77.46), and breast involvement (HR = 6.14, 95% CI = 1.61 to 23.37) were each independently predictive of CNS relapse. Use of IT prophylaxis did not appear to decrease CNS relapse. Median survival after CNS relapse was 3.2 months. CNS relapse, a fatal event, remains a challenge in R-CHOP-treated patients. IT prophylaxis may not be sufficient to reduce CNS relapse, and strategies including systemic agents with high CNS penetration should be evaluated in high-risk patients identified in this study.

Relationship between 'on-treatment platelet reactivity', shear stress, and micro-embolic signals in asymptomatic and symptomatic carotid stenosis.

BACKGROUND: Assessment of 'high on-treatment platelet reactivity (HTPR)' could enhance understanding of the pathophysiology of first or recurrent vascular events in carotid stenosis patients on antiplatelet therapy. METHODS: This prospective, multi-centre study assessed antiplatelet-HTPR status and its relationship with micro-emboli signals (MES) in asymptomatic vs. symptomatic ≥ 50-99% carotid stenosis. Platelet function/reactivity was assessed under 'moderately high shear stress' with the PFA-100® and 'low shear stress' with VerifyNow® and Multiplate® analysers. Bilateral 1-h transcranial Doppler ultrasound of the middle cerebral arteries classified patients as MES + ve or MES - ve. RESULTS: Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Median daily aspirin doses were higher in early symptomatic (225 mg; P < 0.001), but not late symptomatic (75 mg; P = 0.62) vs. asymptomatic patients (75 mg). There was a lower prevalence of aspirin-HTPR in early (28.6%; P = 0.028), but not late symptomatic (38.9%; P = 0.22) compared with asymptomatic patients (56.7%) on the PFA-100®, but not on the VerifyNow® or Multiplate® (P ≤ 0.53). Early symptomatic patients had a higher prevalence of aspirin-HTPR on the PFA-100® (28.6%) vs. VerifyNow® (9.5%; P = 0.049), but not Multiplate® assays (11.9%, P = 0.10). There was no difference in aspirin-HTPR prevalence between any symptomatic vs. asymptomatic MES + ve or MES - ve subgroup. DISCUSSION: Recently symptomatic moderate-severe carotid stenosis patients had a lower prevalence of aspirin-HTPR than their asymptomatic counterparts on the PFA-100®, likely related to higher aspirin doses. The prevalence of antiplatelet-HTPR was positively influenced by higher shear stress levels, but not MES status.

High SUV uptake on FDG-PET/CT predicts for an aggressive B-cell lymphoma in a prospective study of primary FDG-PET/CT staging in lymphoma.

BACKGROUND: Data assessing the role of positron emission tomography (PET)/computed tomography (CT) imaging in lymphoma staging is still being accumulated and current staging is based primarily on CT. This study aims to compare the value of PET/CT over conventional CT and bone marrow biopsy (BMB) in the initial evaluation of patients with lymphoma. METHODS: Data on 122 patients with PET/CT scans as part of their initial staging were prospectively collected and reviewed. All patients had complete staging, including BMB. RESULTS: Among the 122 patients, 101 had non-Hodgkin's lymphoma (NHL) and 21 had Hodgkin's lymphoma (HL). Compared with conventional CT, PET/CT upstaged 21 (17%) cases [B-cell non-Hodgkin's lymphoma (B-NHL), 12; T-cell non-Hodgkin's lymphoma (T-NHL), 3; HL, 6]. Of significance, in 13 patients with 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG)-avid splenic lesions, four had normal CT findings. A maximum FDG uptake of >10 standardized uptake value (SUV) seems to significantly correlate with an aggressive B-cell lineage (odds ratio 2.47, 95% confidence interval 2.23-2.70). Overall, PET scan was concordant with BMB results in 108 (89%) and discordant in 14 (11%) cases. In HL, our data show that PET scan and marrow results agreed in 19 of the cases (90%), being concordantly negative in 18 cases and concordantly positive in one, giving a negative predictive value (NPV) of 100%, sensitivity of 100% and specificity of 90%. Of note, all 13 with early-stage HL had negative PET/CT scan and BMB. In NHL, all 17 cases of T-NHL had concordant PET and BMB results. In patients with aggressive B-NHL, BMB and PET/CT agreed in 58 patients (92%) and disagreed in five (8%), while the corresponding rates in indolent B-cell lymphoma were 14 (67%) and seven patients (33%), respectively. All seven were falsely negative. CONCLUSIONS: PET/CT upstages 17% of cases and detects occult splenic involvement. This may have potential therapeutic and prognostic implications. SUV >10 may predict for an aggressive histology. Except for indolent B-NHL, our data show that PET scans have a good overall NPV in excluding lymphomatous bone marrow involvement. This is particularly true of early-stage HL, suggesting that BMB may be safely omitted in this group.

Efficacy of ezetimibe/simvastatin 10/40 mg compared to doubling the dose of low-, medium- and high-potency statin monotherapy in patients with a recent coronary event.

OBJECTIVE: The aim of the study was to compare the efficacy/safety of doubling the dose of low-, medium- and high-potency statins on lipids/lipoproteins versus ezetimibe/simvastatin (EZE/SIMVA) 10/40 mg in patients with a recent coronary event. METHODS: In this open-label study, patients were stratified by baseline statin therapy (low, medium and high potency) and randomized equally to statin dose doubling or EZE/SIMVA 10/40 mg for 12 weeks. Primary analysis concerned change in low-density lipoprotein cholesterol for the whole population. Treatment-by-stratum interaction evaluated the consistency of treatment effect across statin potency strata. Post hoc analysis of between-group efficacy within strata was performed using ANCOVA. RESULTS: Within each stratum, EZE/SIMVA produced significantly greater reductions in low-density lipoprotein cholesterol, total cholesterol, apolipoprotein B and non-high-density lipoprotein cholesterol (HDL-C) compared to statin doubling. Numerical trends toward smaller between-group reductions were observed with higher-potency statins and reached statistical significance for apolipoprotein B and non-HDL-C. No significant between-group differences in HDL-C and C-reactive protein were observed within each stratum. EZE/SIMVA produced larger reductions in triglycerides versus low-potency statin, whereas it was similarly effective compared with intermediate-/high-potency statins. The safety/tolerability profiles of the treatments were similar across the strata. CONCLUSIONS: EZE/SIMVA 10/40 mg produced greater improvements in lipids with a similar safety profile compared to doubling the dose of low-, medium- and high-potency statins.

A novel targeting signal for proximal clustering of the Kv2.1 K+ channel in hippocampal neurons.

The discrete localization of ion channels is a critical determinant of neuronal excitability. We show here that the dendritic K+ channels Kv2.1 and Kv2.2 were differentially targeted in cultured hippocampal neurons. Kv2.1 was found in high-density clusters on the soma and proximal dendrites, while Kv2.2 was uniformly distributed throughout the soma and dendrites. Chimeras revealed a proximal restriction and clustering domain on the cytoplasmic tail of Kv2.1. Truncations and internal deletions revealed a 26-amino acid targeting signal within which four residues were critical for localization. This signal is not related to other known sequences for neuronal and epithelial membrane protein targeting and represents a novel cytoplasmic signal responsible for proximal restriction and clustering.

Life-threatening coagulopathy associated with use of Campath (alemtuzumab) in maintenance steroid-free renal transplant given before surgery.

We report a case in which an alarming coagulopathy occurred during the operation in a patient receiving a kidney from his spouse. Campath was used for induction of immunosuppression immediately before surgery. There was catastrophic intra-abdominal bleeding associated with severe hypotension, respiratory failure, prolonged partial thrombin time (PTT), normal prothrombin time (PT) and absence of signs of disseminated intravascular coagulation. Multiple tranfusions of blood and blood products were given. Repeated explorations were carried out to secure hemostasis and removal of intra-abdominal blood clots. The coagulopathy improved after 24 h, but recurred within 3 h after the second dose of Campath, given exactly 24 h after the first dose. The coagulopathy also resulted in graft dysfunction, bilateral basal pneumonia, pleural effusions and prolonged abdominal ileus. In spite of the above, the patient went into diuresis and was discharged well after 3 weeks. He was on Prograf (tacrolimus), the sole maintenance immunosuppressor. The pathogenesis of the Campath-related coagulopathy is unclear. We wish to alert the transplant community to this unusual, but catastrophic, complication. We also advocate administering intravenous Campath following the operation, when surgical wounds are more secure and the patient is in a more stable environment.

Lipid-altering efficacy of ezetimibe/simvastatin 10/40 mg compared with doubling the statin dose in patients admitted to the hospital for a recent coronary event: the INFORCE study.

BACKGROUND: The aim of this study was to investigate the efficacy and safety profile of switching to ezetimibe/simvastatin (Eze/Simva) 10/40 mg compared with doubling the statin dose upon discharge in patients taking a statin and admitted to the hospital for the investigation of a coronary event. DESIGN: This phase IV, multi-centre, randomised, open-label, active-controlled, parallel group study enrolled 424 patients (aged >/= 18 years) hospitalised for an acute coronary event and taking a stable dose of a statin (>/= 6 weeks) that could be doubled per the product label. Upon discharge from the hospital, patients were stratified by their statin dose/potency (high, medium and low) and randomised 1 : 1 to doubling of the statin dose (n = 211) or Eze/Simva 10/40 mg (n = 213) for 12 weeks. The primary efficacy variable was the absolute low-density lipoprotein cholesterol (LDL-C) value (mmol/l) at study end-point. RESULTS: Mean baseline LDL-C for the two treatment groups were 2.48 and 2.31 mmol/l for the Eze/Simva and statin groups respectively. At study end-point, least squares mean LDL-C values were 1.74 mmol/l in the Eze/Simva group and 2.22 mmol/l in the statin group resulting in a significant between-group difference of -0.49 mmol/l (p /= 0.160). Significantly more patients achieved LDL-C levels < 2.5 (< 100 mg/dl; 86% vs. 72%), < 2.0 (< 77 mg/dl; 70% vs. 42%) and < 1.8 mmol/l (< 70 mg/dl; 60% vs. 31%) with Eze/Simva than statin (all p /= 3 x upper limit of normal (ULN) or creatine kinase >/= 10 x ULN between the groups. CONCLUSIONS: In patients taking a statin and admitted to the hospital for investigation of a coronary event, treatment with Eze/Simva 10/40 mg for 12 weeks produced greater improvements in lipids with a similar safety profile compared with doubling of the statin dose.

Increased platelet count and reticulated platelets in recently symptomatic versus asymptomatic carotid artery stenosis and in cerebral microembolic signal-negative patient subgroups: results from the HaEmostasis In carotid STenosis (HEIST) study.

BACKGROUND: The pathophysiological mechanisms responsible for the disparity in stroke risk between asymptomatic and symptomatic carotid stenosis patients are not fully understood. The functionally important reticulated platelet fraction and reticulocytes could play a role. OBJECTIVES: We performed a prospective, multi-centre, observational analytical study comparing full blood count parameters and platelet production/turnover/activation markers in patients with asymptomatic versus recently symptomatic moderate (≥ 50-69%) or severe (≥ 70-99%) carotid stenosis. PATIENTS/METHODS: Data from 34 asymptomatic patients were compared with 43 symptomatic patients in the 'early phase' (≤ 4 weeks) and 37 of these patients in the 'late phase' (≥ 3 months) after TIA/ischaemic stroke. Reticulated platelets were quantified by whole blood flow cytometry and reticulated platelets and red cell reticulocytes by 'automated assays' (Sysmex XE-2100™). Bilateral simultaneous transcranial Doppler ultrasound monitoring classified patients as micro-embolic signal (MES)+ve or MES-ve. RESULTS: Mean platelet count was higher in early (216 × 109/L; P = 0.04) and late symptomatic (219 × 109/L; P = 0.044) than asymptomatic patients (194 × 109/L). Mean platelet volume was higher in early symptomatic than asymptomatic patients (10.8 vs. 10.45 fl; P = 0.045). Automated assays revealed higher % reticulated platelet fractions in early (5.78%; P < 0.001) and late symptomatic (5.11%; P = 0.01) than asymptomatic patients (3.48%). Red cell reticulocyte counts were lower in early (0.92%; P = 0.035) and late symptomatic (0.93%; P = 0.036) than asymptomatic patients (1.07%). The automated % reticulated platelet fraction was also higher in early symptomatic than asymptomatic MES-ve patients (5.7 vs. 3.55%; P = 0.001). DISCUSSION: The combination of increased platelet counts and a shift towards production of an increased population of larger, young, reticulated platelets could contribute to a higher risk of first or recurrent cerebrovascular events in recently symptomatic versus asymptomatic carotid stenosis, including those who are MES-ve.

Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma.

Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.

Intrinsic focal adhesion kinase activity controls orthotopic breast carcinoma metastasis via the regulation of urokinase plasminogen activator expression in a syngeneic tumor model.

Expression of focal adhesion kinase (FAK) is elevated in malignant breast cancer, yet the role of intrinsic FAK activity in promoting tumor progression remains undefined. Here, we have inhibited FAK activity or expression in murine 4T1 breast carcinoma cells via dominant-negative focal adhesion kinase-related non-kinase (FRNK) or anti-FAK short hairpin RNA (shRNA) expression, respectively. Neither FRNK nor FAK shRNA ( approximately 80% reduced FAK levels) affected 4T1 proliferation in culture, whereas reduced FAK activity or expression blocked 4T1 cell invasion through Matrigel and resulted in 2-3-fold lower urokinase plasminogen activator (uPA) expression. Control 4T1 cells implanted into mammary fat pads of BALB/c mice exhibited spontaneous metastasis to the lungs, to the peritoneal cavity, and resulted in 90% lethality within 21 days. Whereas FAK shRNA-expressing 4T1 cells formed tumors in mice with low levels of apoptosis, when mammary-injected, these cells did not exhibit lung metastasis after 21 days and caused only 40% lethality up to 60 days. Transient re-expression of wild-type but not kinase-dead FAK in 4T1 FAK shRNA cells promoted uPA production and mammary to lung metastasis within 7 days. In fact, stable human uPA overexpression in 4T1 FAK shRNA cells promoted Matrigel invasion and lung metastasis equal to 4T1 controls. Conversely, treatment with plasminogen activator inhibitor-1 or neutralizing antibody to uPA blocked Matrigel invasion of 4T1 control cells. These studies provide the first direct proof that FAK catalytic activity can facilitate metastatic breast cancer progression by regulating uPA expression.

Intrinsic FAK activity and Y925 phosphorylation facilitate an angiogenic switch in tumors.

Elevated focal adhesion kinase (FAK) expression occurs in advanced cancers, yet a signaling role for FAK in tumor progression remains undefined. Here, we suppressed FAK activity in 4T1 breast carcinoma cells resulting in reduced FAK Y925 phosphorylation, Grb2 adaptor protein binding to FAK, and signaling to mitogen-activated protein (MAP) kinase (MAPK). Loss of a FAK-Grb2-MAPK linkage did not affect 4T1 cell proliferation or survival in culture, yet FAK inhibition reduced vascular endothelial growth factor (VEGF) expression and resulted in small avascular tumors in mice. This FAK-Grb2-MAPK linkage was essential in promoting angiogenesis as reconstitution experiments using Src-transformed FAK-null fibroblasts revealed that point mutations affecting FAK catalytic activity (R454) or Y925 phosphorylation (F925) disrupted the ability of FAK to promote MAPK- and VEGF-associated tumor growth. Notably, in both FAK-inhibited 4T1 and Src-transformed FAK-null cells, constitutively activated (CA) mitogen-activated protein kinase kinase 1 (MEK1) restored VEGF production and CA-MEK1 or added VEGF rescued tumor growth and angiogenesis. These studies provide the first biological support for Y925 FAK phosphorylation and define a novel role for FAK activity in promoting a MAPK-associated angiogenic switch during tumor progression.

Atrial fibrillation in the intact unanesthetized dog: hemodynamic effects during rest, exercise, and beta-adrenergic blockade.

The effects of atrial fibrillation were studied in 12 healthy unanesthetized dogs, 9 to 49 days after surgical implantation of transducers for measurement of aortic flow and left ventricular diameter. Atrial fibrillation and pacing at comparable ventricular rates were induced by electrical stimulation of the right atrial appendage, and their effects were compared with observations made during sinus rhythm in each dog. At rest, cardiac output and mean arterial pressure were not significantly different during sinus rhythm, atrial fibrillation, and atrial pacing. After beta-adrenergic blockade with propranolol, cardiac output during fibrillation was significantly less than that during pacing at comparable ventricular rates. Arterial pressure was not detectably altered. During moderately severe treadmill exercise by six dogs, cardiac output fell significantly upon induction of fibrillation. After pentobarbital anesthesia fibrillation caused decrements in cardiac output and arterial pressure that were accentuated after thoracotomy.These observations suggest the existence of compensatory mechanisms that maintain an essentially constant cardiac output when atrial fibrillation is induced in healthy unanesthetized dogs at rest. These mechanisms appear to fail during moderately severe exercise, beta-adrenergic blockade, and pentobarbital anesthesia.

Effect of left ventricular shape alteration on contractility and function.

We have investigated the effect of left ventricular (LV) shape on contractility and ejection function. In this study, a new contractility index is developed in terms of the wall stress (sigma*, normalized with respect to LV pressure) by means of an LV ellipsoidal model. Using cine-ventriculography data, the LV ellipsoidal model (LVEM) major (B) and minor axes (A) are derived for the entire cardiac cycle. Thereafter, a new contractility index (CONT1) is derived as dsigma*/dt, incorporating the LV ellipsoidal shape factor. Also, another contractility index (CONT2) was developed in terms of the generated sigma* at the start of ejection phase, and maximized with respect to B/Ashape parameter, to obtain the optimal value of B/Aover the physiological ranges of the ratio of myocardial volume and LV volume. The in vivovalue of B/Aat the start of ejection is compared with this optimal value, and the LV contractility is evaluated in terms of the proximity of the in vivo B/Ato the optimal B/A. The results indicate that a non-optimal less-ellipsoidal shape (or more spherical) is associated with decreased contractility (and poor systolic function) of the LV, associated with a failing heart.