cAMP stimulates bicarbonate secretion across normal, but not cystic fibrosis airway epithelia.

Adenosine 3',5'-cyclic monophosphate stimulates chloride (Cl-) secretion across airway epithelia. To determine whether cAMP also stimulates HCO3- secretion, we studied cultured canine and human airway epithelial cells bathed in a HCO3-/CO2-buffered, Cl(-)-free solution. Addition of forskolin stimulated an increase in short-circuit current that was likely a result of bicarbonate secretion because it was inhibited by a HCO3(-)-free solution, by addition of the carbonic anhydrase inhibitor, acetazolamide, or by mucosal addition of the anion channel blocker, diphenylamine 2-carboxylate. The current was dependent on Na+ because it was inhibited by removal of Na+ from the submucosal bathing solution, by addition of the Na+ pump inhibitor, ouabain, or by addition of amiloride (1 mM) to the submucosal solution. An increase in cytosolic Ca2+ produced by addition of a Ca2+ ionophore also stimulated short-circuit current. These data suggest that cAMP and Ca2+ stimulate HCO3- secretion across airway epithelium, and suggest that HCO3- leaves the cell across the apical membrane via conductive pathways. These results may explain previous observations that the short-circuit current across airway epithelia was not entirely accounted for by the sum of Na+ absorption and Cl- secretion. The cAMP-induced secretory response was absent in cystic fibrosis (CF) airway epithelial cells, although Ca(2+)-stimulated secretion was intact. This result suggests that HCO3- exist at the apical membrane is through the Cl- channel that is defectively regulated in CF epithelia. These results suggest the possibility that a defect in HCO3- secretion may contribute to the pathophysiology of CF pulmonary disease.     

Role of miRNAs in immune responses and immunotherapy in cancer

In the past decade, the study of mechanisms of cancer immunity has seen a prominent boom, which paralleled the increased amount of research on the clinical efficacy of immune checkpoint blockade in several lethal types of cancers. This conspicuous effort has led to the development of successful immunotherapy treatment strategies, whose medical impact has been recognized by the awarding of 2018 Nobel Prize in Physiology or Medicine to the two pioneers of check point inhibitor research, Tasuku Honjo and James Allison. Despite these promising achievements, the differences in the clinical response rate in different cancer patients and the high risk of toxicity of immune‐based therapies represent crucial challenges. More remarkably, the causes responsible for different outcome (success vs failure) in patients with tumor having same histotype and clinical characteristics remain mostly unknown. MicroRNAs (miRNAs), small regulatory noncoding RNA molecules representing the most studied component of the dark matter of the human genome, are involved in the regulation of many pathways of cancer and immune cells. Therefore, understanding the role of miRNAs in controlling cancer immunity is necessary, as it can contribute to reveal mechanisms that can be modulated to improve the success of immunetherapy in cancer patients. Here, we discuss the latest findings on immune pathways regulated by miRNAs in cancer, miRNA‐mediated regulation of immune cells in the tumor microenvironment, and miRNAs as potential target for immunotherapies.     

TNF polymorphism and bronchoalveolar lavage cell TNF-alpha levels in chronic beryllium disease and beryllium sensitization

BACKGROUND: Beryllium stimulates TNF-alpha from chronic beryllium disease (CBD) bronchoalveolar lavage (BAL) cells. OBJECTIVE: We sought to relate TNF polymorphisms to beryllium-stimulated TNF-alpha production, to the development of CBD, and to the risk of more severe CBD over time. METHODS: We recruited 147 patients with CBD, 112 beryllium-sensitized subjects, and 323 control subjects; genotyped 5 TNF promoter polymorphisms; and measured beryllium-stimulated and unstimulated BAL cell TNF-alpha production from a subset of subjects. RESULTS: Beryllium-stimulated, but not beryllium-unstimulated, BAL cell TNF-alpha production was significantly increased in patients with CBD compared with that seen in those only sensitized (P = .0002). Those subjects with the TNF -857T allele and the only haplotype (haplotype 4) containing this allele demonstrated significantly lower unstimulated BAL cell TNF-alpha production compared with that seen in noncarriers (P = .009). Patients with CBD alone and combined with sensitized subjects carrying the TNF haplotype 1 compared with those without this haplotype had significantly increased beryllium-stimulated BAL cell TNF-alpha levels (P = .02). We found no significant association between patients with CBD, sensitized subjects, and control subjects with any of the TNF promoter polymorphisms or haplotypes. A greater decrease in Pao(2) at maximum exercise was noted in patients with CBD with the -1031C allele (P = .03) and with haplotypes other than the TNF haplotype 1 (P = .01), 3 (from 5) of which contain the -1031C allele. CONCLUSIONS: The -857T allele and haplotype 1 are associated with BAL cell TNF-alpha production, indicating a potential role of TNF promoter variants in regulation of TNF production in sensitized subjects and patients with CBD. CLINICAL IMPLICATIONS: TNF promoter variants are not risk factors for CBD or sensitization.     

Social conflict exacerbates an animal model of multiple sclerosis

A growing body of evidence suggests that social conflict is associated with inflammatory disease onset and exacerbations in multiple sclerosis (MS) patients and in animal models of MS. This review illustrates how animal research can be used to elucidate the biobehavioral mechanisms underlying the adverse health effects of social conflict. The authors review studies indicating that social conflict exacerbates a virally initiated animal model of MS. This research suggests that the deleterious effects of social conflict may be partially mediated by stress-induced increases in pro-inflammatory cytokine levels in the central nervous system. In addition, they provide evidence that the adverse health effects of social conflict can be prevented by blocking the stress-induced increases in cytokine activity. This suggests that interventions designed to prevent or reverse the stress-induced increases in cytokine activity may be able to prevent or reverse some of the negative health effects of social conflict in humans.     

Cyclic pneumatic soft-tissue compression enhances recovery following fracture of the distal radius: a randomised controlled trial

QUESTIONS: Does the addition of cyclic pneumatic soft-tissue compression during the 6-week immobilisation period following fracture of the distal radius result in a faster recovery of muscle strength and joint range of motion? Does it result in a larger recovery of muscle strength and joint range of motion immediately after the immobilisation period (at 6 weeks) or four weeks after the immobilisation period (at 10 weeks)? DESIGN: Randomised controlled trial with concealed allocation and assessor blinding. PARTICIPANTS: 21 patients with fracture of the distal radius. INTERVENTION: The experimental group received cyclic pneumatic soft-tissue compression during the 6-week immobilisation period whereas the control group received usual care. Both groups were instructed to actively make a fist 100 times per day during the 6-week immobilisation period and were given an exercise program during the 4-week post-immobilisation period. OUTCOME MEASURES: Function was measured as power grip, pinch grip, key grip, and supination strength using dynamometry from Week 1 to 10 as well as wrist flexion/extension and forearm supination/pronation range of motion using goniometry from Week 6 to 10. The outcome measures are presented as a percentage of the intact side. RESULTS: The experimental group improved significantly faster than the control group in muscle strength from Week 1 to 10 (p ? 0.001) but not in joint range of motion from Week 6 to 10 (p > 0.05). By Week 6, the experimental group was 12-26% stronger and had 8-14% more range of motion than the control group. By Week 10, the experimental group was 24-29% stronger and had 10-15% more range of motion than the control group. CONCLUSION: The findings indicate that a larger clinical trial is warranted and should incorporate direct measures of fracture healing.     

Chronic hyperalgesia induced by repeated acid injections in muscle is abolished by the loss of ASIC3, but not ASIC1

Clinically, chronic pain and hyperalgesia induced by muscle injury are disabling and difficult to treat. Cellular and molecular mechanisms underlying chronic muscle-induced hyperalgesia are not well understood. For this reason, we developed an animal model where repeated injections of acidic saline into one gastrocnemius muscle produce bilateral, long-lasting mechanical hypersensitivity of the paw (i.e. hyperalgesia) without associated tissue damage. Since acid sensing ion channels (ASICs) are found on primary afferent fibers and respond to decreases in pH, we tested the hypothesis that ASICs on primary afferent fibers innervating muscle are critical to development of hyperalgesia and central sensitization in response to repeated intramuscular acid. Dorsal root ganglion neurons innervating muscle express ASIC3 and respond to acidic pH with fast, transient inward and sustained currents that resemble those of ASICs. Mechanical hyperalgesia produced by repeated intramuscular acid injections is prevented by prior treatment of the muscle with the non-selective ASIC antagonist, amiloride, suggesting ASICs might be involved. ASIC3 knockouts do not develop mechanical hyperalgesia to repeated intramuscular acid injection when compared to wildtype littermates. In contrast, ASIC1 knockouts develop hyperalgesia similar to their wildtype littermates. Extracellular recordings of spinal wide dynamic range (WDR) neurons from wildtype mice show an expansion of the receptive field to include the contralateral paw, an increased response to von Frey filaments applied to the paw both ipsilaterally and contralaterally, and increased response to noxious pinch contralaterally after the second intramuscular acid injection. These changes in WDR neurons do not occur in ASIC3 knockouts. Thus, activation of ASIC3s on muscle afferents is required for development of mechanical hyperalgesia and central sensitization that normally occurs in response to repeated intramuscular acid. Therefore, interfering with ASIC3 might be of benefit in treatment or prevention of chronic hyperalgesia.     

Lectin binding and endocytosis at the apical surface of human airway epithelia

The specificity of lectin binding to distinct saccharides makes them valuable reagents for investigation and identification of cells within complex tissues and potentially for delivery of agents into cells. Therefore we examined lectin binding to airway epithelia. We used an in vitro model of primary cultures of well-differentiated human airway epithelia and applied the lectins to the apical surface of living epithelia. This approach limited binding specifically to the extracellular surface of the apical membrane. Of 32 lectins studied, we found 15 that bound to the apical membrane. The pattern varied from diffuse binding to the surface of nearly all the cells, to binding to a small subset of the cells. Our data combined with earlier studies identify lectins that may be used to detect specific populations of epithelial cells. Because lectins may be used to deliver a variety of agents, including gene transfer vectors, to airway cells, we examined endocytosis of lectins. We found that several lectins bound to the apical surface were actively taken up into the cells. These data may be of value for studies of airway epithelial structure and may facilitate the targeting of the epithelial apical surface.     

Automated computerized intensive care unit severity of illness measure in the Department of Veterans Affairs: preliminary results. SISVistA Investigators. Scrutiny of ICU Severity Veterans Health Sysyems Technology Architecture

OBJECTIVE: To evaluate the feasibility of an automated intensive care unit (ICU) risk adjustment tool (acronym: SISVistA) developed by selecting a subset of predictor variables from the Acute Physiology and Chronic Health Evaluation (APACHE) III available in the existing computerized database of the Department of Veterans Affairs (VA) healthcare system and modifying the APACHE diagnostic and comorbidity approach. DESIGN: Retrospective cohort study. SETTING: Six ICUs in three Ohio Veterans Affairs hospitals. PATIENT SELECTION: The first ICU admission of all patients from February 1996 through July 1997. OUTCOME MEASURE: Mortality at hospital discharge. METHODS: The predictor variables, including age, comorbidity, diagnosis, admission source (direct or transfer), and laboratory results (from the +/- 24-hr period surrounding admission), were extracted from computerized VA databases, and APACHE III weights were applied using customized software. The weights of all laboratory variables were added and treated as a single variable in the model. A logistic regression model was fitted to predict the outcome and the model was validated using a boot-strapping technique (1,000 repetitions). MAIN RESULTS: The analysis included all 4,651 eligible cases (442 deaths). The cohort was predominantly male (97.5%) and elderly (63.6 +/- 12.0 yrs). In multivariate analysis, significant predictors of hospital mortality included age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.04-1.09), comorbidity (OR, 1.11; 95% CI, 1.08-1.15), total laboratory score (OR, 1.07; 95% CI, 1.06-1.08), direct ICU admission (OR, 0.39; 95% CI, 0.31-0.49), and several broad ICU diagnostic categories. The SISVistA model had excellent discrimination and calibration (C statistic = 0.86, goodness-of-fit statistics; p > .20). The area under the receiver operating characteristic curve of the validated model was 0.86. CONCLUSIONS: Using common data elements often found in hospital computer systems, SISVistA predicts hospital mortality among patients in Ohio VA ICUs. This preliminary study supports the development of an automated ICU risk prediction system on a more diverse population.     

Abnormal GABAergic Function and Negative Affect in Schizophrenia

Deficits in the γ-aminobutyric acid (GABA) system have been reported in postmortem studies of schizophrenia, and therapeutic interventions in schizophrenia often involve potentiation of GABA receptors (GABAR) to augment antipsychotic therapy and treat negative affect such as anxiety. To map GABAergic mechanisms associated with processing affect, we used a benzodiazepine challenge while subjects viewed salient visual stimuli. Fourteen stable, medicated schizophrenia/schizoaffective patients and 13 healthy comparison subjects underwent functional magnetic resonance imaging using the blood oxygenation level-dependent (BOLD) technique while they viewed salient emotional images. Subjects received intravenous lorazepam (LRZ; 0.01 mg/kg) or saline in a single-blinded, cross-over design (two sessions separated by 1–3 weeks). A predicted group by drug interaction was noted in the dorsal medial prefrontal cortex (dmPFC) as well as right superior frontal gyrus and left and right occipital regions, such that psychosis patients showed an increased BOLD signal to LRZ challenge, rather than the decreased signal exhibited by the comparison group. A main effect of reduced BOLD signal in bilateral occipital areas was noted across groups. Consistent with the role of the dmPFC in processing emotion, state negative affect positively correlated with the response to the LRZ challenge in the dmPFC for the patients and comparison subjects. The altered response to LRZ challenge is consistent with altered inhibition predicted by postmortem findings of altered GABAR in schizophrenia. These results also suggest that negative affect in schizophrenia/schizoaffective disorder is associated—directly or indirectly—with GABAergic function on a continuum with normal behavior.