Differential activation of CREB by Ca2+/calmodulin-dependent protein kinases type II and type IV involves phosphorylation of a site that negatively regulates activity

The cAMP response element-binding protein (CREB) has been shown to mediate transcriptional activation of genes in response to both cAMP and calcium influx signal transduction pathways. The roles of two multifunctional calcium/calmodulin-dependent protein kinases, CaMKIV and CaMKII, were examined in transient transfection studies that utilized either the full-length or the constitutively active forms of these kinases. The results indicate that CaMKIV is much more potent than CaMKII in activating CREB in three different cell lines. It was also found in these studies that Ser133 of CREB is essential for its activation by CaMKIV. Because both CaMKII and CaMKIV can phosphorylate CREB, we pursued further the mechanism by which CaMKII and CaMKIV differentially regulate CREB activity. Mutagenesis studies and phosphopeptide mapping analysis demonstrated that in vitro, CaMKIV phosphorylates CREB at Ser133 only, whereas CaMKII phosphorylates CREB at Ser133 and a second site, Ser142. Transient transfection studies revealed that phosphorylation of Ser142 by CaMKII blocks the activation of CREB that would otherwise occur when Ser133 is phosphorylated. When Ser142 was mutated to alanine, CREB was activated by CaMKII, as well as by CaMKIV. Furthermore, mutation of Ser142 to alanine enhanced the ability of Ca2+ influx to activate CREB, suggesting a physiological role for the phosphorylation of Ser142 in modulation of CREB activity. These data provide evidence for a new mechanism for regulation of CREB activity involving phosphorylation of a negative regulatory site in the transcriptional activation domain. The studies also provide new insights into possible interactions between the cAMP and Ca2+ signaling pathways in the regulation of transcription. In particular, changes in intracellular Ca2+ have the potential to either inhibit or augment the ability of cAMP to stimulate transcription, depending on the presence of specific forms of Ca2+/calmodulin-dependent protein kinases.

Oxygenated carotenoid lutein and progression of early atherosclerosis: the Los Angeles atherosclerosis study

BACKGROUND

Carotenoids are hypothesized to explain some of the protective effects of fruit and vegetable intake on risk of cardiovascular disease. The present study assessed the protective effects of the oxygenated carotenoid lutein against early atherosclerosis.

METHODS AND RESULTS

EPIDEMIOLOGY

Progression of intima-media thickness (IMT) of the common carotid arteries over 18 months was determined ultrasonographically and was related to plasma lutein among a randomly sampled cohort of utility employees age 40 to 60 years (n=480). Coculture: The impact of lutein on monocyte response to artery wall cell modification of LDL was assessed in vitro by quantification of monocyte migration in a coculture model of human intima. Mouse models: The impact of lutein supplementation on atherosclerotic lesion formation was assessed in vivo by assigning apoE-null mice to chow or chow plus lutein (0.2% by weight) and LDL receptor-null mice to Western diet or Western diet plus lutein. IMT progression declined with increasing quintile of plasma lutein (P for trend=0.007, age-adjusted; P=0.0007, multivariate). Covariate-adjusted IMT progression (mean+/-SEM) was 0.021+/-0.005 mm in the lowest quintile of plasma lutein, whereas progression was blocked in the highest quintile (0.004+/-0.005 mm; P=0.01). In the coculture, pretreatment of cells with lutein inhibited LDL-induced migration in a dose-dependent manner (P<0.05). Finally, in the mouse models, lutein supplementation reduced lesion size 44% in apoE-null mice (P=0.009) and 43% in LDL receptor-null mice (P=0.02).

CONCLUSIONS

These epidemiological, in vitro, and mouse model findings support the hypothesis that increased dietary intake of lutein is protective against the development of early atherosclerosis.

Dexmedetomidine provides cortical neuroprotection: impact on anaesthetic-induced neuroapoptosis in the rat developing brain

BACKGROUND

Recent evidence has demonstrated the anti-apoptotic of dexmedetomidine in different brain injury models. Herein, we investigated whether dexmedetomidine could directly protect against cortical injury in vitro and in vivo.

METHODS

Apoptosis was induced by staurosporine or wortmannin treatment in cortical neuronal cultures in vitro or by 6 h of isoflurane (0.75%) administration to post-natal day 7 rat pups in vivo. Dexmedetomidine was then applied in escalating doses to assess the neuroprotective potential of this agent. Cell survival was quantified using an MTT assay in vitro and in vivo apoptosis was assessed using cleaved caspase-3 immunohistochemistry. Cortical Western blots were conducted for the cellular survival proteins Bcl-2 and phosphorylated extracellular signal-regulated protein kinase (pERK)1 and 2.

RESULTS

In vitro dexmedetomidine dose-dependently prevented both staurosporine- and wortmannin-induced injury in cortical neuronal cultures, indicating that dexmedetomidine can prevent apoptosis when applied directly. In vivo isoflurane induced cortical neuroapoptosis compared with air (327+/-80 vs. 34+/-9 caspase-3-positive neurons; P<0.05). Dexmedetomidine inhibited isoflurane-induced caspase-3 expression (P<0.05), although the protection achieved did not completely attenuate the isoflurane injury (P<0.05 vs. air). Isoflurane treatment decreased Bcl-2 and pERK protein expression relative to air, an effect reversed by dexmedetomidine treatment.

CONCLUSIONS

Dexmedetomidine prevents cortical apoptosis in vitro and in vivo. However, using higher doses of dexmedetomidine does not further increase protection against isoflurane injury in the cortex than previously observed.

Long-term efficacy and immune responses following immunization with the RTS,S malaria vaccine

The malaria sporozoite vaccine candidate RTS,S, formulated with an oil-in-water emulsion plus the immunostimulants monophosphoryl lipid A and the saponin derivative QS21 (vaccine 3), recently showed superior efficacy over two other experimental formulations. Immunized volunteers were followed to determine the duration of protective immune responses. Antibody levels decreased to between one-third and one-half of peak values 6 months after the last dose of vaccine. T cell proliferation and interferon-gamma production in vitro were observed in response to RTS,S or hepatitis B surface antigen. Seven previously protected volunteers received sporozoite challenge, and 2 remained protected (1/1 for vaccine 1, 0/1 for vaccine 2, and 1/5 for vaccine 3). The prepatent period was 10.8 days for the control group and 13.2 days for the vaccinees (P < .01). Immune responses did not correlate with protection. Further optimization in vaccine composition and/or immunization schedule will be required to induce longer-lasting protective immunity.

p53-independent role of MDM2 in TGF-beta1 resistance

Transforming growth factor-beta (TGF-beta) inhibits cell proliferation, and acquisition of TGF-beta resistance has been linked to tumorigenesis. A genetic screen was performed to identify complementary DNAs that abrogated TGF-beta sensitivity in mink lung epithelial cells. Ectopic expression of murine double minute 2 rescued TGF-beta-induced growth arrest in a p53-independent manner by interference with retinoblastoma susceptibility gene product (Rb)/E2F function. In human breast tumor cells, increased MDM2 expression levels correlated with TGF-beta resistance. Thus, MDM2 may confer TGF-beta resistance in a subset of tumors and may promote tumorigenesis by interference with two independent tumor suppressors, p53 and Rb.

Regulation of activating transcription factor-1 and the cAMP response element-binding protein by Ca2+/calmodulin-dependent protein kinases type I, II, and IV

The ability of activating transcription factor-1 (ATF1) or the cAMP response element-binding protein (CREB) to enhance transcription can be stimulated by increases in intracellular Ca2+ concentrations. To identify protein kinases which may mediate the ability of Ca2+ to activate these transcription factors, we compared the ability of constitutively active forms of several Ca2+/calmodulin-dependent protein kinases (CaM kinases) to activate ATF1 or CREB. We find that constitutively active CaM kinase I and IV can activate both ATF1 and CREB. In addition, expression vectors for full-length CaM kinase I and IV were able to augment the ability of Ca2+ influx to activate ATF1 or CREB consistent with a role for these kinases in mediating transcriptional responses to Ca2+ signaling. In contrast, CaM kinase II was unable to activate either ATF1 or CREB. These findings provide a potential mechanism that may permit variation in the ability of ATF1 and CREB to respond to changes in intracellular Ca2+ concentrations depending on differences in the relative concentrations of specific CaM kinases.

Breast-feeding and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

BACKGROUND

Several studies have reported that the risk of breast cancer decreases with increasing duration of breast-feeding. Whether breast-feeding is associated with a reduced risk of hereditary breast cancer in women who carry deleterious BRCA1 and BRCA2 mutations is currently unknown.

METHODS

We conducted a case-control study of women with deleterious mutations in either the BRCA1 or the BRCA2 gene. Study participants, drawn from an international cohort, were matched on the basis of BRCA mutation (BRCA1 [n = 685] or BRCA2 [n = 280]), year of birth (+/-2 years), and country of residence. The study involved 965 case subjects diagnosed with breast cancer and 965 control subjects who had no history of breast or ovarian cancer. Information on pregnancies and breast-feeding practices was derived from a questionnaire administered to the women during the course of genetic counseling. Conditional logistic regression analyses were used to estimate odds ratios (ORs) for the risk of breast cancer. All statistical tests were two-sided.

RESULTS

Among women with BRCA1 mutations, the mean total duration of breast-feeding was statistically significantly shorter for case subjects than for control subjects (6.0 versus 8.7 months, respectively; mean difference = 2.7 months, 95% confidence interval [CI] = 1.4 to 4.0; P<.001). The total duration of breast-feeding was associated with a reduced risk of breast cancer (for each month of breast-feeding, OR = 0.98, 95% CI = 0.97 to 0.99; P(trend)<.001). Women with BRCA1 mutations who breast-fed for more than 1 year were less likely to have breast cancer than those who never breast-fed (OR = 0.55, 95% CI = 0.38 to 0.80; P =.001), although no such association was seen for BRCA2 (OR = 0.95, 95% CI = 0.56 to 1.59; P =.83).

CONCLUSIONS

Women with deleterious BRCA1 mutations who breast-fed for a cumulative total of more than 1 year had a statistically significantly reduced risk of breast cancer.

Tubal ligation and risk of ovarian cancer in carriers of BRCA1 or BRCA2 mutations: a case-control study

BACKGROUND

In several case-control and prospective studies, tubal ligation has been associated with a decreased risk of invasive epithelial ovarian cancer. We aimed to assess the potential of tubal ligation in reducing the risk of ovarian cancer in women who carry predisposing mutations in the BRCA1 or BRCA2 genes.

METHODS

We did a matched case-control study among women from Canada, the USA, and the UK who had undergone genetic testing and who carried a pathogenic mutation in BRCA1 or BRCA2. Cases were 232 women with a history of invasive ovarian cancer, and controls were 232 women without ovarian cancer, and who had both ovaries intact. Cases and controls were matched for year of birth, country of residence, and mutation (BRCA1 or BRCA2). The odds ratio for developing ovarian cancer was estimated for tubal ligation, adjusting for oral contraceptive use, parity, history of breast cancer, and ethnic group.

FINDINGS

In an unadjusted analysis among BRCA1 carriers, significantly fewer cases than controls had ever had tubal ligation (30 of 173 [18%] vs 60 of 173 [35%], odds ratio 0.37 [95% CI 0.21-0.63]; p=0.0003). After adjustment for oral contraceptive use, parity, history of breast cancer and ethnic group, the odds ratio was 0.39 (p=0.002). Combination of tubal ligation and past use of an oral contraceptive was associated with an odds ratio of 0.28 (0.15-0.52). No protective effect of tubal ligation was seen among carriers of the BRCA2 mutation.

INTERPRETATION

Tubal ligation is a feasible option to reduce the risk of ovarian cancer in women with BRCA1 mutations who have completed childbearing.

Caspase inhibitors reduce neuronal injury after focal but not global cerebral ischemia in rats

BACKGROUND AND PURPOSE

Studies show that blocking the activation of caspases by the caspase inhibitors z-VAD.FMK and z-DEVD.FMK can reduce ischemic neuronal injury after cerebral ischemia. Because the severity of ischemia was mild in some studies, we tested the efficacy of these caspase inhibitors on moderately severe but transient forebrain and focal ischemic insults in the rat.

METHODS

Various regimens of z-VAD, z-DEVD, and control DMSO were given to rats subjected to either 4-vessel occlusion ischemia (4-VO, 10-minute occlusion, 7-day survival) or distal middle cerebral artery occlusion (MCAo, 90-minute occlusion, 22.5-hour survival). In global ischemia, treatments were given immediately after ischemia (experiment 1) or as preischemic and postischemic treatments (experiment 2). Three focal ischemia experiments were done. Injection times were 60 minutes into ischemia (experiment 1) and 60 minutes into ischemia plus 30 and 120 minutes after ischemia (experiment 2). Experiment 3 was identical to experiment 2 except that a 30-minute preischemia treatment was instituted. Core normothermia was maintained in all experiments during ischemia. However, in the last focal and global experiments, core and brain temperatures, respectively, were also measured after ischemia with telemetry probes. Because hyperthermia accompanied z-DEVD treatment, an extra z-DEVD-treated group (MCAo) was included with temperature clamped at normothermia.

RESULTS

Neither z-VAD nor z-DEVD significantly reduced CA1 injury after global ischemia. In focal ischemia, both drugs significantly reduced infarction, but only in the third experiment, and the prevention of hyperthermia that accompanied z-DEVD treatment did not alter this.

CONCLUSIONS

These results suggest a detrimental role of caspases in moderately severe focal but not global cerebral ischemia.

Effects of Bacillus subtilis natto on performance and immune function of preweaning calves

The effects of Bacillus subtilis natto on performance and immune function of dairy calves during the preweaning phase were investigated in this study. Twelve Holstein male calves 7 ± 1 d of age were randomly allotted to 2 treatments of 6 calves. The Bacillus subtilis natto was mixed with milk and fed directly to the calves. The calves were weaned when their starter intake reached 2% of their weight. Blood was collected and IgA, IgE, IgG, IgM, and cytokine levels in the serum of all the calves were determined. The results showed that Bacillus subtilis natto increased general performance by improving the average daily gain and feed efficiency and advanced the weaning age of the calves. No difference was observed in serum IgE, IgA, and IgM, whereas serum IgG was higher in the Bacillus subtilis natto-supplemented calves than in the control calves. Furthermore, calves fed with Bacillus subtilis natto were found to secrete more IFN-γ, but tended to produce less IL-4 than did the control calves, although serum IL-6 and IL-10 were not affected. This study demonstrated that Bacillus subtilis natto did not stimulate IgE-mediated allergic reactions, but increased serum IgG and IFN-γ levels in the probiotic-fed calves. We propose that the viable probiotic characteristics of Bacillus subtilis natto benefit calf immune function.

Rapid progression of prostate cancer in men with a BRCA2 mutation

Men with BRCA2 mutations have been found to be at increased risk of developing prostate cancer. There is a recent report that BRCA2 carriers with prostate cancer have poorer survival than noncarrier prostate cancer patients. In this study, we compared survival of men with a BRCA2 mutation and prostate cancer with that of men with a BRCA1 mutation and prostate cancer. We obtained the age at diagnosis, age at death or current age from 182 men with prostate cancer from families with a BRCA2 mutation and from 119 men with prostate cancer from families with a BRCA1 mutation. The median survival from diagnosis was 4.0 years for men with a BRCA2 mutation vs 8.0 years for men with a BRCA1 mutation, and the difference was highly significant (P<0.01). It may be important to develop targeted chemotherapies to treat prostate cancer in men with a BRCA2 mutation.

Breaking bonds in male prairie vole: long-term effects on emotional and social behavior, physiology, and neurochemistry

Social relationships are essential for many fundamental aspects of life while bond disruption can be detrimental to mental and physical health. Male prairie voles form enduring social bonds with their female partners, allowing the evaluation of partner loss on behavior, physiology, and neurochemistry. Males were evaluated for partner preference formation induced by 24h of mating, and half were separated from their partner for 4 wk. In Experiment 1, partner loss significantly increased anxiety-like behaviors in the elevated plus maze and light-dark box tests and marginally increased depressive-like behaviors in the forced swim test. In addition, while intruder-directed aggression is common in pair bonded prairie voles, separated males were affiliative and lacked aggression toward an unfamiliar female and an intruding male conspecific. Partner loss increased the density of oxytocin-immunoreactivity (-ir), vasopressin-ir, and corticotrophin-releasing hormone-ir cells in the paraventricular nucleus of the hypothalamus and oxytocin-ir cells in the supraoptic nucleus. Tyrosine hydroxylase-ir was not affected. In Experiment 2, partner preference was observed after 2 wk of partner loss but eliminated after 4 wk partner loss. Body weight gain and plasma corticosterone concentrations were elevated throughout the 4 wk. No effects were observed for plasma oxytocin or vasopressin. Together, partner loss elicits anxiety-like and depression-like behaviors, disrupts bond-related behaviors, and alters neuropeptide systems that regulate such behaviors. Thus, partner loss in male prairie voles may provide a model to better understand the behavior, pathology, and neurobiology underlying partner loss and grief.

Identification of benzo[a]pyrene metabolites in cervical mucus and DNA adducts in cervical tissues in humans by gas chromatography-mass spectrometry

Epidemiological studies indicate that cigarette smoking increases the risk of cervical cancer. To address questions regarding possible mechanisms of tobacco-related cervical carcinogenesis, in a pilot study, using supercritical fluid extraction and a gas chromatographic-mass spectrometric (GC-MS) technique, we detected and characterized benzo[a]pyrene and its metabolites, namely B[a]P-dihydrodiols, phenols and tetraols in cervical mucus samples from eight smokers and non-smokers. Twenty-eight epithelial and stromal cervical tissue samples from seventeen patients undergoing surgery for non-malignant disease were quantitatively analyzed for BPDE-DNA adducts by a GC-MS technique. BPDE-DNA adducts were found in 25 samples. The mean level of BPDE-DNA adducts in epithelial cervical tissues of smokers was nearly two-fold greater than that in self-reported non-smokers; P = 0.02. The mean number of BPDE-adducts (+/- SD) in epithelial cervical tissues of smokers was 3.5 +/- 1.06 adducts/10(8) nucleotides while that in non-smokers was 1.8 +/- 0.96 adducts/10(8) nucleotides. The mean number of BPDE-DNA adducts in stromal cervical tissues of the same subjects was 1.8 +/- 0.96 adducts/10(8) nucleotides in smokers and that in the stromal tissues of non-smokers was 1.4 +/- 1.1 adducts/10(8). These results suggest that polynuclear aromatic hydrocarbons (PAHs) from tobacco smoke and other environmental sources can be transported to the cervix where they are metabolized in the cervical epithelium to ultimate carcinogenic agents, although transport of ultimate carcinogenic metabolites from other organs to the cervix cannot be ruled out. Exposure of cervical epithelia to PAHs and their carcinogenic metabolites suggests a potential role of such carcinogens in the pathogenesis of cervical cancer in humans.

Meta-analysis of adjuvant chemotherapy after radical surgery for advanced gastric cancer

BACKGROUND

There is no consensus of opinion about postoperative adjuvant chemotherapy after radical surgery for advanced gastric cancer. This is a meta-analysis of the published results of relevant randomized clinical trials (RCTs).

METHODS

Electronic databases from January 1998 to December 2007 were searched and 12 RCTs were selected. These included a total of 3809 patients. The hazard ratio (HR) for overall survival was calculated.

RESULTS

The pooled HR for overall survival was 0.78 (95 per cent confidence interval 0.71 to 0.85) in favour of chemotherapy. Subgroup analysis showed that the advantage of chemotherapy was not influenced by depth of tumour infiltration, status of lymph node metastasis, type of lymphadenectomy, geographical distribution of patients or route of drug administration.

CONCLUSIONS

Postoperative chemotherapy can improve overall survival after radical surgery for gastric cancer; there is no standardized chemotherapy regimen. Japanese-style D2 radical surgery plus oral 5-fluorouracil appears an effective treatment at present.

A proteomic analysis reveals the loss of expression of the cell death regulatory gene GRIM-19 in human renal cell carcinomas

Gene associated with retinoid interferon-induced mortality (GRIM)-19, an inhibitor of transcription factor STAT3, was originally identified as a critical regulatory protein in a genetic screen that was designed to identify the gene products necessary for Interferon (IFN)-beta- and retinoic acid-induced cell death. Over expression of GRIM-19 activates cell death. Conversely, inactivation of its expression promotes cell growth. STAT3 is a transcription factor that regulates gene expression in response to multiple extra cellular growth factors. In contrast to its normal feedback inhibition, a constitutive activation of STAT3 has been documented in several tumors. Although many STAT3-inhibitors are described, their relevance to human cancer is unclear. In an attempt to define the molecular alterations associated with human renal cell carcinoma (RCC) using mass spectrometry, we have discovered that expression of GRIM-19 is lost or severely depressed in a number of primary RCC and in some urinogenital tumors. Using an RCC cell line, we show that down regulation of GRIM-19 promotes tumor growth via an augmentation of STAT3-dependent gene expression. These studies for the first time show a tumor-suppressor like activity of GRIM-19.

Breast cancer risks in women with a family history of breast or ovarian cancer who have tested negative for a BRCA1 or BRCA2 mutation

Genetic testing for mutations in BRCA1 and BRCA2 is available in Canada for women with a significant family history of breast cancer. For the majority of tested women, a BRCA1 or BRCA2 mutation is not found, and counselling regarding breast cancer risk is based on the review of the pedigree. In this prospective study, we estimate breast cancer risks in women with a family history of breast cancer and for whom the proband tested negative for a mutation in BRCA1 or BRCA2. Families with two or more breast cancers under the age of 50 years, or with three cases of breast cancer at any age, and who tested negative for a BRCA1 or BRCA2 mutation were identified. Follow-up information on cancer status was collected on all first-degree relatives of breast cancer cases. The standardised incidence ratios (SIRs) for breast cancer were calculated by dividing the observed numbers of breast cancer by the expected numbers of breast cancers, based on the rates in the provincial cancer registries. A total of 1492 women from 365 families were included in the analyses. The 1492 first-degree relatives of breast cancer cases contributed 9109 person-years of follow-up. Sixty-five women developed breast cancer, compared to 15.2 expected number (SIR=4.3). The SIR was highest for women under the age of 40 (SIR=14.9) years and decreased with increasing age. However, the absolute risk was higher for women between the age of 50 and 70 (1% per year) years than for women between 30 and 50 (0.4% per year) years of age. There was no elevated risk for ovarian, colon or any other form of cancer. Women with a significant family history of breast cancer (ie, two or more breast cancers under the age of 50 years, or three or more breast cancers at any age), but who test negative for BRCA mutations have approximately a four-fold risk of breast cancer. Women in these families may be candidates for tamoxifen chemoprevention and/or intensified breast screening with an MRI.

Project towards no tobacco use: 1-year behavior outcomes

OBJECTIVES

We present 1-year follow-up data from a school-based tobacco use prevention project designed to test the effectiveness of three main components of social influence programs. The components teach refusal skills, awareness of social misperceptions about tobacco use, and misconceptions about physical consequences.

METHODS

Four different curricula were developed and tested in a randomized experiment involving 48 junior high schools. The outcome variables examined were changes in initial and weekly cigarette and smokeless tobacco use 1 year after the intervention.

RESULTS

Analyses indicated that each of the component programs were effective in decreasing both the initial and the weekly use of cigarettes except for the curriculum in which refusal skills were taught. Also, each curriculum was effective in decreasing the initial use of smokeless tobacco except for the one aimed at correcting social misperceptions. Only the combined curriculum showed an effect on the weekly use of smokeless tobacco.

CONCLUSIONS

The combined intervention was the most effective overall in reducing the initial and weekly use of cigarettes and smokeless tobacco. This suggests that different reasons for use exist and need to be counteracted simultaneously. However, since single programs were also effective in reducing all but weekly smokeless tobacco use, any of these components may be worthwhile prevention tools.

NF-κB mediated miR-21 regulation in cardiomyocytes apoptosis under oxidative stress

Oxidative stress, defined as an excess production of reactive oxygen species (ROS), is shown to play an important role in the pathophysiology of cardiac remodeling including cell death and contractile dysfunction. Therefore, the balance between ROS production and removal of excess ROS is essential in maintaining the redox state and homeostasis balance in the cell. The increased ROS further activates nuclear factor-κB (NF-κB), a redox-sensitive transcription factor and promotes cell death. Recently, microRNAs (miRNAs) have been identified as critical regulators of various pathophysiological processes of cardiac remodeling; however, NF-κB-mediated miRNA's role in cardiomyocytes under oxidative stress remains undetermined. The miR-21 has been implicated in diverse cardiac remodeling; but, NF-κB-mediated miR-21 modulation in oxidative stress is currently unknown. Neonatal cardiomyocytes were transfected with IκBα mutant, miR-21 mimetic, and inhibitors separately, and were challenged with H2O2. The target gene, programmed cell death 4 (PDCD4), ROS activity, and NF-κB translocation were analyzed. Our results indicated that NF-κB positively regulated miR-21 expression under oxidative stress, and PDCD4 was a direct target for miR-21. NF-κB further regulated the expression of PDCD4 in H2O2-induced oxidative stress. Moreover, H2O2-induced ROS activity and cardiomyocytes apoptosis were partly protected by overexpression of miR-21 and displayed an important role in ROS-mediated cardiomyocytes injury. We evaluated a critical role of NF-κB-mediated miR-21 modulation in H2O2-induced oxidative stress in cardiomyocytes by targeting PDCD4. Our data may provide a new insight of miR-21's role in cardiac diseases primarily mediated by ROS.

CHOP Infant Coma Scale ("Infant Face Scale"): a novel coma scale for children less than two years of age

The Glasgow Coma Scale (GCS) is the most frequently used tool worldwide for assessing the severity of neurologic injury after brain trauma, although applying this scale to infants and younger children can be problematic. The CHOP Infant Coma Scale, or Infant Face Scale (IFS), is a novel scale for children under 2 years of age which differs from other pediatric coma scales in the following ways: (1) it relies on objective behavioral observations; (2) it assesses cortical as well as brainstem function; (3) it parallels the GCS in scoring but is based on infant-appropriate behaviors; and (4) it can be applied to intubated patients. We report the results of a prospective study designed to compare interrater reliability between the IFS and GCS in children less than 2 years of age. Seventy-five hospitalized children less than 2 years of age were assessed simultaneously by a pair of observers, representing a spectrum of health care professionals, who scored the children using both the IFS and GCS. Interrater reliability for each pair of observers for each scale was assessed using the kappa statistic. A second series of 10 infants in the intensive care unit with specific diagnoses of acute traumatic or hypoxic/ischemic brain injury were similarly assessed. In the 75 hospitalized infants with a variety of diagnoses, interrater reliability for the GCS was in the "almost perfect," "slight," and "fair" range for the eye-opening, motor, and verbal subtests, respectively. In contrast, the IFS showed interrater reliability in the "almost perfect," "substantial," and "almost perfect" ranges for the three subtests. When applied to infants in an intensive care unit with acute traumatic brain injury or hypoxia/ischemia, the GCS interrater reliability scores were in the "fair" range, while the IFS scores were in the "almost perfect" range. The IFS demonstrates improved interrater reliability in direct comparison to the GCS, particularly in the "verbal/face" component where most pediatric coma scales are deficient. The IFS may prove to be a simple and practical bedside index of brain injury severity in children less than two years of age.

Characteristics of pyrexia in BRAFV600E/K metastatic melanoma patients treated with combined dabrafenib and trametinib in a phase I/II clinical trial

BACKGROUND

Pyrexia is a frequent adverse event with combined dabrafenib and trametinib therapy (CombiDT), but little is known of its clinical associations, etiology, or appropriate management.

PATIENTS AND METHODS

All patients on the BRF133220 phase I/II trial of CombiDT treated at the standard dose (150/2) were included for assessment of pyrexia (n = 201). BRAF and MEK inhibitor-naïve patients (n = 117) were included for efficacy analyses. Pyrexia was defined as temperature ≥38°C (≥100.4(°)F) or related symptoms.

RESULTS

Fifty-nine percent of patients developed pyrexia during treatment, 24% of which had pyrexia symptoms without a recorded elevation in body temperature. Pyrexia was grade 2+ in 60% of pyrexia patients. Median time to onset of first pyrexia was 19 days, with a median duration of 9 days. Pyrexia patients had a median of two pyrexia events, but 21% had three or more events. Various pyrexia management approaches were conducted in this study. A trend was observed between dabrafenib and hydroxy-dabrafenib exposure and pyrexia. No baseline clinical characteristics predicted pyrexia, and pyrexia was not statistically significantly associated with treatment outcome.

CONCLUSIONS

Pyrexia is a frequent and recurrent toxicity with CombiDT treatment. No baseline features predict pyrexia, and it is not associated with clinical outcome. Dabrafenib and metabolite exposure may contribute to the etiology of pyrexia. The optimal secondary prophylaxis for pyrexia is best studied in a prospective trial.

Epidermal growth factor receptor glycosylation is required for ganglioside GM3 binding and GM3-mediated suppression [correction of suppresion] of activation

Gangliosides are able to bind to the epidermal growth factor receptor and inhibit its activation, but the mechanism of this inhibition is unknown. To address the role of receptor carbohydrates in facilitating interaction with gangliosides, we examined the ability of GM3 to bind the deglycosylated receptor and inhibit its autophosphorylation. Flow cytometry studies demonstrated that deglycosylation of the receptor did not affect its ability to be transported to the cell membrane. In contrast with the native (fully glycosylated) receptor, GM3 did not coimmunoprecipitate with the deglycosylated receptor. Using a novel colorimetric bead binding assay, GM3 was shown to bind well to the immunoprecipitated native receptor but not at all to the deglycosylated receptor. Finally, the addition of GM3 to cells with deglycosylated epidermal growth factor receptors did not result in significant further inhibition of autophosphorylation of the receptor, despite a 10-fold decrease in phosphorylation of the native epidermal growth factor receptor by 200 microM GM3. These studies suggest that ganglioside affects epidermal growth factor receptor activity through a direct interaction that requires receptor glycosylation, and contribute to our understanding of the role of gangliosides in cell membrane function.

Fabrication of nanometer-sized electrodes and tips for scanning electrochemical microscopy

A novel method for fabrication of nanometer-sized electrodes and tips suitable for scanning electrochemical microscopy (SECM) is reported. A fine etched Pt wire is coated with polyimide, which was produced by polymerization on the Pt surface initiated by heat. This method can prepare electrodes with effective radii varying from a few to hundreds of nanometers. Scanning electron microscopy, cyclic voltammetry, and SECM were used to characterize these electrodes. Well-defined steady-state voltammograms could be obtained in aqueous or in 1,2-dichloroethane solutions. This method produced the nanoelectrodes with exposed Pt on the apex, and they can also be employed as the nanotips for SECM investigations. Different sizes of Pt nanotips made by this method were employed to evaluate the kinetics of the redox reaction of Ru(NH3)6(3+) on the surface of a large Pt electrode by SECM, and the standard rate constant kappa0 of this system was calculated from the best fit of the SECM approach curve. This result is similar to the values obtained by analysis of the obtained voltammetric data.