PKC inhibition results in a Kv1.5 + Kvβ1.3 pharmacology closer to Kv1.5 channels

Background and Purpose

The K_vβ1.3 subunit modifies the gating and pharmacology of K_v1.5 channels in a PKC-dependent manner, decreasing channel sensitivity to bupivacaine- and quinidine-mediated blockade. Cardiac K_v1.5 channels associate with receptor for activated C kinase 1 (RACK1), the K_vβ1.3 subunit and different PKC isoforms, resulting in the formation of a functional channelosome. The aim of the present study was to investigate the effects of PKC inhibition on bupivacaine and quinidine block of K_v1.5 + K_vβ1.3 channels.

Experimental Approach

HEK293 cells were transfected with K_v1.5 + K_vβ1.3 channels, and currents were recorded using the whole-cell configuration of the patch-clamp technique. PKC inhibition was achieved by incubating the cells with either calphostin C or bisindolylmaleimide II and the effects of bupivacaine and quinidine were analysed.

Key Results

The voltage-dependent inactivation of K_v1.5 + K_vβ1.3 channels and their pharmacological behaviour after PKC inhibition with calphostin C were similar to those displayed by K_v1.5 channels alone. Indeed, the IC₅₀ values for bupivacaine were similar in cells whose PKC was inhibited with calphostin C or bisindolylmaleimide II. Similar results were also observed in the presence of quinidine.

Conclusions and Implications

The finding that the voltage-dependence of inactivation and the pharmacology of K_v1.5 + K_vβ1.3 channels after PKC inhibition resembled that observed in K_v1.5 channels suggests that both processes are dependent on PKC-mediated phosphorylation. These results may have clinical relevance in diseases that are characterized by alterations in kinase activity.     

The expression patterns and prognostic significance of pleckstrin homology-like domain family A (PHLDA) in lung cancer and malignant mesothelioma

BackgroundPleckstrin homology domain family A (PHLDA) genes play important roles in cancer cellular processes, including inhibiting Akt activation, repressing growth factor signaling, inhibiting the negative feedback of EGFR/ErbB2 signaling cells, and inducing apoptosis. However, the prognostic significance of PHLDA in non-small cell lung cancer (NSCLC) and malignant pleural mesothelioma (MM) remains unclear. The present study investigates the associations between PHLDA expression patterns and their prognostic value in lung adenocarcinoma (LUAD) and MM.MethodsWe analyzed PHLDA family members at the genomic level in silico to explore their mRNA expression pattern and predictive significance in LUAD and MM. We then created a PHLDA–drug interaction network and a protein-protein interaction (PPI) network using different databases. Finally, we immunohistochemically assessed the protein expression of each PHLDA family member on tissue microarrays (TMAs) in both LUAD and MM cohorts with long-term follow-up.ResultsWhile PHLDA1 mRNA expression in both LUAD and MM was lower than that of normal tissue, PHLDA2 mRNA was significantly overexpressed in LUAD, and PHLDA3 mRNA was overexpressed in MM. In NSCLC, both low PHLDA1 mRNA expression and high PHLDA3 mRNA expression correlated with worse overall survival (OS) (P<0.01), whereas high PHLDA2 mRNA expression was associated with better OS (P<0.01). In MM, patients presenting high PHLDA1 and PHLDA2 mRNA expression had poor OS (P=0.01 and P<0.01, respectively). In addition, the PHLDA-drug interaction network indicated that several common drugs could potentially modulate PHLDA expression, and the PPI network suggested that PHLDA1 interacts with Notch family members, whereas PHLDA3 interacts with TP53. Our results also showed that the expression of PHLDA2 and PHLDA3 was significantly higher in LUAD and MM than that of PHLDA1 (P<0.05) and was associated with the risk of death. While patients with PHLDA2 >85.09 cells/mm² had a low risk of death (P=0.01) and a median survival time of 48 months, those with PHLDA3 <70.38 cells/mm² had a high risk of death (P=0.03) and a median survival time of 34 months.ConclusionsWe shed light on the role of the PHLDA family as promising predictive biomarkers and potential therapeutic targets in LUAD and MM.     

Epidemiological and clinical characteristics of community‐acquired and nosocomial influenza cases and risk factors associated with complications: A four season analysis of all adult patients admitted in a tertiary hospital

BackgroundInformation on the characteristics of patients with nosocomial influenza and associated complications is scarce. This study compared epidemiological and clinical characteristics of patients admitted with hospital‐acquired influenza (HAI) to those with community‐acquired influenza (CAI) and analyzed risk factors associated with complications.MethodsThis retrospective, observational study included all adult patients with confirmed influenza virus infection admitted to Son Espases University Hospital during the influenza season in Spain (October to May) from 2012‐2013 to 2015‐2016. Symptom onset before admission was included as CAI, and 2 days after admission or within 48 hours after previous discharge were considered as HAI.ResultsOverall, 666 patients with laboratory‐confirmed influenza were included; 590 (88.6%) and 76 (11.4%) had CAI and HAI, respectively. Baseline characteristics and vaccination rates were similar in both groups. Patients with HAI had significantly fewer symptoms, less radiological alterations, and earlier microbiological diagnosis than those with CAI. Eighty‐five (14.4%) and 20 (27.6%) CAI and HAI patients, respectively, experienced at least one complication, including septic shock, admission to the intensive care unit, mechanical ventilation or evolution to death (any one, P = .003). Univariate and multivariate binary logistic regression was performed to assess independent risk factors associated with the occurrence of complications: nosocomial infection, diabetes, oseltamivir treatment, having received no vaccination, microbiological delay, dyspnea, and the state of confusion were the most important significant factors.ConclusionsOur study shows the need to implement microbiological diagnostic measures in the first 48 hours to reduce HAI frequency and associated complications.     

Association of Trichomonas vaginalis with sociodemographic factors and other STDs among female inmates in Lisbon

A study on STDs was conducted among 211 female inmates in a prison in Lisbon, Portugal, in order to establish possible associations between Trichomonas vaginalis infection, sociodemographic factors and other STDs. T. vaginalis was found in 31.2% of the women, from whom only 65.1% presented symptoms. It was more frequently isolated in the 20-40 year age group. On univariate analysis there was an association, although not statistically significant, between the existence of T. vaginalis, multiple sexual partners, drug addiction and no condom use. A statistically significant association was found between trichomoniasis, prostitution and other STDs. These were found in 87% of all women. T. vaginalis was detected alone in 23.8% (15/63) of all women with trichomoniasis, while 76.2% (48/63) of them had multiple infections with trichomonas and other STDs. A statistically significant association was present between trichomoniasis and Mycoplasma hominis and infection with Treponema pallidum. This study showed that the prevalence of T. vaginalis is as high as that of multiple infections with other STDs. Therefore, our findings seem to confirm that trichomoniasis serves as a marker for other STDs. Screening for STDs should then be offered to Portuguese inmates, or, at least, these women should be screened for T. vaginalis, as a marker for the other STDs.     

Liver changes in patients with hyperthyroidism

We studied liver changes in the hepatic biopsies of five patients with hyperthyroidism. A characteristic histopathologic picture consisting of mild to moderate intrahepatocytic cholestasis, lobular inflammatory infiltrate with some eosinophils, and Kupffer cell hyperplasia was found in all cases. We discuss the specificity, clinicopathological correlations and the possible pathophysiology of these lesions.     

Obscure gastrointestinal bleeding: a complication of radiation enteritis diagnosed by wireless capsule endoscopy.

Obscure gastrointestinal bleeding is a common disorder and may account for as many as 5% of all gastrointestinal hemorrhages. It is often caused by lesions in the small intestine, which were very complicated to examine prior to the advent of wireless capsule endoscopy. Here we present the case of a 31-year-old woman with obscure gastrointestinal bleeding as a complication of radiation enteritis, which was diagnosed only after she underwent an examination with wireless capsule endoscopy. This technique has proven to be far superior to other radiographic and endoscopic methods in diagnosing obscure gastrointestinal bleeding and pathologies of the small intestine in general.     

Pathological and virological findings in patients with persistent hypertransaminasaemia of unknown aetiology

BACKGROUND: The histopathological spectrum and role of hepatitis viruses in cases of hypertransaminasaemia of unknown aetiology have not been correctly analysed in a sufficiently large number of patients. METHODS: We studied 1075 consecutive patients referred for liver biopsy because of elevation of alanine aminotransferase (ALT) levels for more than six months. From this population we selected those cases in whom the aetiology could not be defined from clinical, biochemical, and serological data obtained before biopsy. In these patients liver biopsies were reviewed, and hepatitis B virus (HBV)-DNA and hepatitis C virus (HCV)-RNA were assayed in serum by polymerase chain reaction (PCR). Serum hepatitis G virus (HGV)-RNA was determined by PCR in 74 patients. RESULTS: Of 1075 patients studied, the cause of the increased serum ALT levels remained elusive after appropriate testing in 109 patients (10.1%). Liver biopsies from these patients showed non-specific changes in 32.7% of cases, non-alcoholic steatohepatitis (NASH) in 15.8%, and chronic hepatitis or cirrhosis in 51.5%. HBV-DNA and/or HCV-RNA was detected more frequently in cryptogenic liver disease than in healthy blood donors (26.7% v 3.4%; p<0.001). HGV-RNA was found in only one patient. The proportion of cases with detectable HBV-DNA or HCV-RNA was 14.3% in patients with non-specific changes or NASH, 30.7% in patients with chronic hepatitis, and 61.5% in patients with cirrhosis. Cirrhosis was found more frequently in patients with positive HBV-DNA and/or HCV-RNA in serum than in those who tested negatively (p=0.005). CONCLUSIONS: In our series, patients in whom biochemical and serological data did not determine the aetiology of the disease represented 10% of all cases referred for liver biopsy for persistent elevation of serum transaminases. Approximately 50% of patients had chronic hepatitis or cirrhosis and the remainder had NASH or non-specific changes. Occult viral infections were found in a high proportion of cases in the first group and in a low percentage of patients in the second.     

Measuring functional status of chronic coronary patients: Reliability, validity and responsiveness to clinical change of the reduced version of the Duke Activity Status Index (DASI)

AIMS: Health-related quality of life assessment may be useful forunderstanding the variability in functioning of patients witha similar level of clinical impairment. We assessed the reliability,validity and responsiveness to clinical change of a reducedversion of the Duke Activity Status Index (DASI) in chroniccoronary patients. METHODS AND RESULTS: The reduced version of the DASI, a measure of self-reportedfunctional capacity, was administered twice to two groups ofpatients: 46 stable coronary heart disease outpatients weretested and re-tested 2 weeks after their initial visit; and44 patients undergoing elective angioplasty for angina pectoriswere evaluated the day before and one month after the procedure.The Canadian Cardiovascular Society (CCS) functional grade wasassessed in all patients, and a treadmill exercise test wasperformed sequentially (before and after the procedure) in angioplastypatients. Cronbach's alpha reliability coefficients for reducedDASI scores were high (between 0·81 and 0·89).Correlations of the reduced DASI scores with CCS grade and exercisetest duration were moderately high (r= – 0·51 andr=0·45, respectively). Improvement after angioplastyas assessed by the reduced DASI scores was important (effectsize=0·75, P<0·001). CONCLUSION: The reduced DASI is reliable, valid and responsive to clinicalchanges. Health-related quality of life measures may be usefulin monitoring coronary patients.     

Increased interleukin-13 mRNA expression in bronchoalveolar lavage cells of atopic patients with mild asthma after repeated low-dose allergen provocations

Immune and inflammatory responses mediated by cytokines are essential in the pathophysiology of asthma. The aim of this study was to analyse the cytokine mRNA profiles in bronchoalveolar lavage (BAL) cells of patients with mild atopic asthma, before and after induction of a subclinical allergic airway inflammation. For this purpose, eight patients with mild atopic asthma received low-dose allergen inhalations equivalent to 10% of a provocational dose causing a 20% fall in forced expiratory flow in 1 sec (PD20) for 7 weekdays. BAL was performed before and after low-dose provocations in patients, and without provocation in five healthy controls. Alveolar macrophages (AM) were enriched by negative selection, using magnetic beads, to enable separate studies of the BAL cells. Using a semiquantitative RT-PCR technique, the mRNA expression of macrophage-derived cytokines interleukin (IL)-1, IL-6, IL-8, IL-10, IL-12, IL-13, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta was analysed. After low-dose provocations, we observed a significant increase in the expression of IL-13 mRNA (P = 0.01) in BAL cells enriched for AM of the asthmatic patients. The increased IL-13 mRNA positively correlated with the proportion of BAL fluid eosinophils (r = 0.7, P = 0.05). Moreover, a tendency was found towards an increased IL-1 and a reduced IL-6, IL-8, IFN-gamma and TNF-alpha expression by the BAL cells. Comparing asthmatic patients before low-dose provocations and healthy controls, a significantly higher expression of IL-6 (P<0.003), IL-10 (P<0.005) and TGF-beta (P<0.003) and a significantly lower expression of IL-8 (P<0.005) and TNF-alpha (P<0.01) was detected in the patients. In summary, repeated low-dose allergen provocations of asthmatic patients results in a modified BAL cell cytokine mRNA profile with increased production of IL-13, that may be of importance for the development of a Th2-like immune response. A possible source of the increased IL-13 mRNA is AM, which may have a more active function in the allergic inflammation than previously thought.