Interleukin-3-induced phosphorylation of BAD through the protein kinase Akt

BAD is a distant member of the Bcl-2 family that promotes cell death. Phosphorylation of BAD prevents this. BAD phosphorylation induced by interleukin-3 (IL-3) was inhibited by specific inhibitors of phosphoinositide 3-kinase (PI 3-kinase). Akt, a survival-promoting serine-threonine protein kinase, was activated by IL-3 in a PI 3-kinase-dependent manner. Active, but not inactive, forms of Akt were found to phosphorylate BAD in vivo and in vitro at the same residues that are phosphorylated in response to IL-3. Thus, the proapoptotic function of BAD is regulated by the PI 3-kinase-Akt pathway.

The future challenges facing the development of new antimicrobial drugs

The emergence of resistance to antibacterial agents is a pressing concern for human health. New drugs to combat this problem are therefore in great demand, but as past experience indicates, the time for resistance to new drugs to develop is often short. Conventionally, antibacterial drugs have been developed on the basis of their ability to inhibit bacterial multiplication, and this remains at the core of most approaches to discover new antibacterial drugs. Here, we focus primarily on an alternative novel strategy for antibacterial drug development that could potentially alleviate the current situation of drug resistance--targeting non-multiplying latent bacteria, which prolong the duration of antimicrobial chemotherapy and so might increase the rate of development of resistance.

Anti-inflammatory effects of low-dose oral theophylline in atopic asthma

Theophylline, in addition to its bronchodilator effect, may attenuate inflammation in asthma. We did a double-blind placebo-controlled study of the effect of oral theophylline on the inflammatory response of the bronchial mucosa to inhalation of allergen in 19 atopic asthmatic subjects. Bronchoscopy and bronchial biopsy were done 24 hours after allergen inhalation before and after six weeks of treatment with oral slow-release theophylline, 200 mg 12 hourly. The mean serum concentration was 36.6 mumol/L, which is below the currently-accepted therapeutic range. After treatment with theophylline there was a significant reduction in the number of EG2-positive activated eosinophils (5.9 before and 2.1 after treatment, Wilcoxon signed rank p < 0.05) and total eosinophils (16.7 before and 7.6 after treatment, p < 0.05) beneath the epithelial basement membrane. We conclude that low-dose oral theophylline attenuates airway inflammatory response to allergen inhalation in atopic asthma.

Syndecans, cell surface heparan sulfate proteoglycans, are induced by a proline-rich antimicrobial peptide from wounds

Cell surface heparan sulfate proteoglycans, such as the syndecans, are required for cellular responses to heparin-binding growth factors and extracellular matrix components. Expression of syndecan-1 and -4 is induced in mesenchymal cells during wound repair in the mouse, consistent with a role for syndecans in regulating cell proliferation and migration in response to these effectors. Here we show that wound fluid contains inductive activity that mimics the in vivo induction in time of appearance, specificity for mesenchymal cells, and selectivity for syndecan-1 and -4. We have purified and synthesized a 4.8-kDa proline-rich protein from wound fluid that reproduces this induction of syndecan-1 and -4 in cultured cells. This peptide, identical to the antibacterial peptide PR-39, is released into the wound by the cellular infiltrate and induces syndecan expression at the same peptide concentrations that lyse bacteria. These results indicate that wounds contain a multifunctional protein that induces mammalian cells to express cell surface heparan sulfate proteoglycans as part of the wound repair process and that kills bacteria as part of a nonimmune defense mechanism.

Constitutive activation of stat 3 oncogene product in human ovarian carcinoma cells

OBJECTIVE

Stat 3 functions in transducing signals from the cell's surface to its nucleus and activation of gene transcription. Aberrations of Stat 3 in breast cancer have raised the possibility of its contribution to oncogenesis. Our goal was to examine ovarian cancer cell lines to determine whether Stat 3 plays a relevant role in ovarian carcinogenesis.

METHODS

Protein lysates were extracted from normal ovarian surface epithelial cells and malignant cells. Western blotting techniques were performed with phosphorylation-independent or phosphorylation-specific Stat 3 (tyrosine 705) antibody. Confirmation of Stat 3 activation was determined by a luciferase reporter driven by a promoter containing Stat 3-specific binding sites. Bcl-x(L) and cyclin D(1) were also analyzed by Western blotting.

RESULTS

MDAH 2774, OV-1063, Caov-3, and O.C. 22819 expressed high levels of phosphorylated Stat 3. In contrast, A2780 and normal ovarian surface epithelial cells had little Stat 3 phosphorylation recognized. Confirmation of persistent activation of Stat 3 activity was shown by transfection of cells with a Stat 3 luciferase reporter. Potential downstream mediators of Stat 3 including Bcl-x(L) and cyclin D(1) were also evaluated. In cells expressing activated Stat 3, high levels of both Bcl-x(L) and cyclin D(1) were detected, whereas in A2780 cells, which did not express activated Stat 3, only low levels of Bcl-x(L) and cyclin D(1) were expressed.

CONCLUSIONS

Constitutive activation of Stat 3 is present in ovarian cancer lines but not in normal ovarian surface epithelial cells. Activation of Stat 3 is a common event during oncogenic transformation upstream to both Bcl-x(L) and cyclin D(1). The relationship of this aberrancy of ovarian carcinoma harboring activated Stat 3 deserves further investigation.

Influence of N-acetylcysteine on chronic bronchitis or COPD exacerbations: a meta-analysis

In order to clarify the possible role of N-acetylcysteine (NAC) in the treatment of patients with chronic bronchitis and chronic obstructive pulmonary disease (COPD), we have carried out a meta-analysis testing the available evidence that NAC treatment may be effective in preventing exacerbations of chronic bronchitis or COPD and evaluating whether there is a substantial difference between the responses induced by low (≤ 600 mg per day) and high (> 600 mg per day) doses of NAC. The results of the present meta-analysis (13 studies, 4155 COPD patients, NAC n = 1933; placebo or controls n = 2222) showed that patients treated with NAC had significantly and consistently fewer exacerbations of chronic bronchitis or COPD (relative risk 0.75, 95% CI 0.66-0.84; p < 0.01), although this protective effect was more apparent in patients without evidence of airway obstruction. However, high doses of NAC were also effective in patients suffering from COPD diagnosed using spirometric criteria (relative risk 0.75, 95% CI 0.68-0.82; p = 0.04). NAC was well tolerated and the risk of adverse reactions was not dose-dependent (low doses relative risk 0.93, 95% CI 0.89-0.97; p = 0.40; high doses relative risk 1.11, 95% CI 0.89-1.39; p = 0.58). The strong signal that comes from this meta-analysis leads us to state that if a patient suffering from chronic bronchitis presents a documented airway obstruction, NAC should be administered at a dose of ≥ 1200 mg per day to prevent exacerbations, while if a patient suffers from chronic bronchitis, but is without airway obstruction, a regular treatment of 600 mg per day seems to be sufficient.

Interference with Heparin Binding and Oligomerization Creates a Novel Anti-Inflammatory Strategy Targeting the Chemokine System

A hallmark of autoimmunity and other chronic diseases is the overexpression of chemokines resulting in a detrimental local accumulation of proinflammatory immune cells. Chemokines play a pivotal role in cellular recruitment through interactions with both cell surface receptors and glycosaminoglycans (GAGs). Anti-inflammatory strategies aimed at neutralizing the chemokine system have to-date targeted inhibition of the receptor-ligand interaction with receptor antagonists. In this study, we describe a novel strategy to modulate the inflammatory process in vivo through mutation of the essential heparin-binding site of a proinflammatory chemokine, which abrogates the ability of the protein to form higher-order oligomers, but retains receptor activation. Using well-established protocols to induce inflammatory cell recruitment into the peritoneal cavity, bronchoalveolar air spaces, and CNS in mice, this non-GAG binding variant of RANTES/CCL5 designated [44AANA47]-RANTES demonstrated potent inhibitory capacity. Through a combination of techniques in vitro and in vivo, [44AANA47]-RANTES appears to act as a dominant-negative inhibitor for endogenous RANTES, thereby impairing cellular recruitment, not through a mechanism of desensitization. [44AANA47]-RANTES is unable to form higher-order oligomers (necessary for the biological activity of RANTES in vivo) and importantly forms nonfunctional heterodimers with the parent chemokine, RANTES. Therefore, although retaining receptor-binding capacity, altering the GAG-associated interactive site of a proinflammatory chemokine renders it a dominant-negative inhibitor, suggesting a powerful novel approach to generate disease-modifying anti-inflammatory reagents.

Neutrophil and platelet complexes and their relevance to neutrophil recruitment and activation

The manifestation of platelet 'satallitism' around neutrophils in whole blood is a long acknowledged phenomenon [1]. Circulating platelet-neutrophil complexes (PNC) occur in a diverse range of inflammatory disorders and infections that affect numerous organs of the body. Animal models have revealed that the formation of PNC is required for the recruitment of neutrophils to inflamed tissue, since platelets 'prime' neutrophils for efficient adhesion to vascular endothelium via the up-regulation of integrins and enhanced responsiveness to chemokines (Fig. 1). Perhaps surprisingly, the surface contact between platelets and neutrophils additionally enhances other neutrophil functions, such as chemotaxis that is required for migration into tissues, trans-cellular production of eicosanoids, phagocytosis and trapping of pathogens, increased respiratory burst leading to the production of reactive oxygen species (ROS), and modulation of neutrophil apoptosis (Fig. 1). Platelet P-selectin appears to have a particular role in enhancing the majority of these activities, and the influence of platelet P-selectin is not therefore confined to the initial rolling events in the process of neutrophil extravasation.

Comparison of Positron Emission Tomography Scanning and Sentinel Node Biopsy in the Detection of Micrometastases of Primary Cutaneous Malignant Melanoma

PURPOSE: Sentinel node biopsy (SNB) is a surgical technique for detecting micrometastatic disease in the regional draining nodes. 2-fluorine-18-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) scanning is an imaging technique that can detect clinically undetectable metastases. This prospective study was undertaken to compare the sensitivity of FDG-PET scanning with SNB in the detection of micromatastatic malignant melanoma.

PATIENTS AND METHODS: Fifty consecutive patients (23 women, 27 men; mean age, 53 years) with primary melanoma >1 mm thick or lymphatic invasion were recruited (mean, 2.41 mm). Primary lesions had been narrowly excised (<1 cm). Patients underwent PET scanning followed by SNB, using a dual technique. Preoperative lymphoscintigraphy was used to identify the draining basin. Lymph nodes were examined histologically and immunostained for S100 and HMB 45.

RESULTS: The sentinel node (SN) was identified in all patients. Fourteen patients (28%) had positive SNBs, including eight patients with melanoma <1.5 mm thick. In none of these 14 patients did PET scans identify metastatic disease in the SN or draining basin. In seven patients, the PET scans were positive in other locations, and in four cases, this was suspicious of metastatic disease. However, no patient has developed recurrent melanoma (mean follow-up, 15 months). All patients with positive SNBs underwent therapeutic lymph node dissection. Further lymph node involvement was found in two patients (primary lesions, 1.3 mm and 3.5 mm thick).

CONCLUSION: This study demonstrates the limitations of FDG-PET scanning in staging patients with primary melanoma. SNB is the only reliable method for identifying micrometastatic disease in the regional draining node.

Parathyroid risk in total thyroidectomy for bilateral, benign, multinodular goitre: report of 351 surgical cases

Aims: To evaluate the risk of hypocalcaemia (transient or permanent) after total thyroidectomy for bilateral, benign, multinodular goitre, the frequency and impact of unintentional parathyroidectomy, and the value of parathyroid gland autotransplantation during thyroid surgery.

Materials and methods: This was a retrospective study of 351 surgical patients who had undergone total thyroidectomy for bilateral, benign, multinodular goitre over a seven-year period. The primary endpoint was serum calcium concentration immediately post-operatively and during follow up. Normal serum calcium concentration was defined as 2 mmol/l. Parathyroid data were collected during surgery and histological examination.

Results: In 62 per cent of cases, no hypocalcaemia had been observed after surgery. In 35 per cent of cases, transient hypocalcaemia had been observed after surgery. In 3 per cent of cases, chronic hypocalcaemia had been present six months after surgery. Permanent hypoparathyroidism had been diagnosed two years after surgery in 1.4 per cent of cases. Unintentional parathyroidectomy had been detected in 5.2 per cent of cases. Parathyroid gland autotransplantation had been performed in 7 per cent of cases during surgery.

Conclusion: Permanent hypoparathyroidism is rare, although transient hypoparathyroidism occurs relatively frequently. Unintentional parathyroidectomy and parathyroid gland autotransplantation do not affect serum calcium levels.

Comparison of the effects of Viscoat and Healon on postoperative intraocular pressure

We compared the effects of Viscoat and Healon on postoperative increases in intraocular pressure in patients undergoing uncomplicated extracapsular cataract extraction with posterior chamber intraocular lens implantation in a prospective, randomized, single-masked study. Eleven eyes received Viscoat and 13 received Healon. The Viscoat or Healon was aspirated from the anterior chamber with the irrigation-aspiration tip of an automated irrigation-aspiration system at the end of the procedure. No prophylactic intraoperative or postoperative ocular hypotensive agents were used. Intraocular pressure was measured at three, six, 12, and 24 hours postoperatively. Compared with preoperative intraocular pressure, postoperative intraocular pressure was significantly increased in both the Viscoat group and the Healon group. Some postoperative intraocular pressures were as high as 50 to 60 mm Hg, despite removal of the viscoelastic substance at the end of surgery. There was no significant difference in the postoperative intraocular pressures of the Viscoat group and the Healon group.

Nebulised heparin as a treatment for COVID-19: scientific rationale and a call for randomised evidence

Nebulised unfractionated heparin (UFH) has a strong scientific and biological rationale and warrants urgent investigation of its therapeutic potential, for COVID-19-induced acute respiratory distress syndrome (ARDS). COVID-19 ARDS displays the typical features of diffuse alveolar damage with extensive pulmonary coagulation activation resulting in fibrin deposition in the microvasculature and formation of hyaline membranes in the air sacs. Patients infected with SARS-CoV-2 who manifest severe disease have high levels of inflammatory cytokines in plasma and bronchoalveolar lavage fluid and significant coagulopathy. There is a strong association between the extent of the coagulopathy and poor clinical outcomes.The anti-coagulant actions of nebulised UFH limit fibrin deposition and microvascular thrombosis. Trials in patients with acute lung injury and related conditions found inhaled UFH reduced pulmonary dead space, coagulation activation, microvascular thrombosis and clinical deterioration, resulting in increased time free of ventilatory support. In addition, UFH has anti-inflammatory, mucolytic and anti-viral properties and, specifically, has been shown to inactivate the SARS-CoV-2 virus and prevent its entry into mammalian cells, thereby inhibiting pulmonary infection by SARS-CoV-2. Furthermore, clinical studies have shown that inhaled UFH safely improves outcomes in other inflammatory respiratory diseases and also acts as an effective mucolytic in sputum-producing respiratory patients. UFH is widely available and inexpensive, which may make this treatment also accessible for low- and middle-income countries.These potentially important therapeutic properties of nebulised UFH underline the need for expedited large-scale clinical trials to test its potential to reduce mortality in COVID-19 patients.

Stopping Bacterial Adhesion: A Novel Approach to Treating Infections

Adhesion and colonization are prerequisites for the establishment of bacterial pathogenesis. The prevention of adhesion is an attractive target for the development of new therapies in the prevention of infection. Bacteria have developed a multiplicity of adhesion mechanisms commonly targeting surface carbohydrate structures, but our ability to rationally design effective antiadhesives is critically affected by the limitations of our knowledge of the human 'glycome' and of the bacterial function in relation to it. The potential for the future development of carbohydrate-based antiadhesives has been demonstrated by a significant number of in vitro and in vivo studies. Such therapies will be particularly relevant for infections of mucosal surfaces where topical application or delivery is possible.

3T MR imaging of postoperative recurrent middle ear cholesteatomas: value of periodically rotated overlapping parallel lines with enhanced reconstruction diffusion-weighted MR imaging

BACKGROUND AND PURPOSE

MR diagnostic of postoperative recurrent cholesteatomas is difficult. Our purpose was to compare multishot fast spin-echo periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted MR imaging (DWI) with array spatial sensitivity encoding technique (ASSET) single-shot echo-planar DWI and late postgadolinium T1-weighted MR imaging for the detection of postoperative recurrent middle ear cholesteatomas with a 3T imaging unit.

MATERIALS AND METHODS

Thirty-five patients with suggested postoperative recurrent middle ear cholesteatoma underwent 3T MR imaging with PROPELLER DWI, ASSET echo-planar DWI, and late postgadolinium T1-weighted MR imaging. Three radiologists (2 seniors, 1 fellow) analyzed unlabeled images for visualization of recurrence. Interobserver and intraobserver agreement was assessed by using the Cohen kappa statistic test. Sensitivity, specificity, and predictive value were assessed for the 3 observers.

RESULTS

Nineteen recurrent cholesteatomas were diagnosed. PROPELLER interobserver agreement was very good (1, 0.89, 0.89) among the 3 observers. Intraobserver agreement between PROPELLER and T1-weighted imaging was very good to moderate (0.88, 0.57, 0.58). PROPELLER DWI provided less interobserver variability than other sequences, and the best sensitivity, specificity, and predictive value.

CONCLUSIONS

On a 3T imaging unit, multishot fast spin-echo PROPELLER DWI allows an easier detection of postoperative recurrent middle ear cholesteatoma than T1-weighted imaging by reducing artifacts and by its better contrast. DWI with PROPELLER is diagnostically robust and accurate.

Characterization of adenosine receptors involved in adenosine-induced bronchoconstriction in allergic rabbits

1. Recent work has suggested that adenosine may be involved in asthma via the activation of A1 receptors. However, the role of the recently cloned A3 receptor in airways is largely unknown. In the present study, we have investigated the role of the A3 receptor in adenosine-induced bronchoconstriction in allergic rabbits. 2. Aerosol challenge of antigen (Ag) immunized rabbits with the adenosine precursor, adenosine 5'-monophosphate (AMP), resulted in a dose-dependent fall in dynamic compliance (Cdyn). The maximum fall in Cdyn in these rabbits was significantly greater than that in litter matched, sham immunized animals (P < 0.05). However, there was no significant difference in the maximum increase in airways resistance (Rt) between Ag and sham immunized rabbits (P > 0.05). 3. Aerosol challenge of Ag immunized rabbits with cyclopentyl-adenosine (CPA) (A1-receptor agonist) elicited a dose-dependent fall in Cdyn in Ag immunized rabbits and the maximum fall in Cdyn in these rabbits was significantly greater than that observed in sham immunized rabbits (P < 0.05). Similarly, CPA induced dose-dependent increases in R1 in Ag immunized rabbits whereas sham immunized rabbits failed to respond to CPA within the same dose range. The maximum increase in RL in Ag immunized rabbits was significantly greater than that of sham immunized rabbits (P < 0.05). 4. Aerosol challenge of either Ag or sham immunized rabbits with the A3 agonist aminophenylethyladenosine (APNEA) did not elicit dose-dependent changes in either RL or Cdyn. Moreover, there was no significant difference in the maximum response, measured by either parameter, between the two animal groups (P > 0.05). 5. These data provide further evidence for a role of the A1 receptor in the airways, but do not support a role for the A3 receptor in adenosine-induced bronchoconstriction in the allergic rabbit.

p38 and JNK have distinct regulatory functions on the development of apoptosis during simulated ischaemia and reperfusion in neonatal cardiomyocytes

Rat neonatal ventricular myocytes exposed to simulated ischaemia and reperfusion (SI/R) were used as an in vitro model to delineate the role(s) of extracellular signal-regulated kinase (ERK), p38 and c-Jun NH(2)-terminal protein kinase (JNK), as well as PKB in apoptosis. Exposure of the myocytes to SI (simulated ischaemia - energy depletion induced by KCN and 2-deoxy- D-glucose) reduced cell viability, as measured by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay, and stimulated apoptosis as evidenced by caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage. However, morphological evidence of increased apoptosis, detected by staining with Hoechst 33342, was only seen in response to reperfusion. This suggests that although ischaemic conditions are sufficient to induce cellular markers of apoptosis (PARP cleavage and caspase-3 activation), reperfusion is required to complete the apoptotic pathway in these cells. Furthermore, SI resulted in a rapid, strong, biphasic activation of p38 concomitant with a weak and transient activation of the two ERK isoenzymes, p42/p44-MAPK. Reperfusion for 5 minutes resulted in a strong phosphorylation of p42/p44-MAPK, while no additional p38 activation was seen at this stage. On the other hand, p46/p54-MAPK (JNK) was phosphorylated in response to 5 minutes of reperfusion only and not during SI alone. A peak of PKB/Akt (Ser(473)) activity was seen within 5 minutes of exposure to SI, whereas PKB/Akt (Thr(308)) phosphorylation remained at the baseline level. Both PKB/Akt phosphorylation sites (Ser(473) and Thr(308)) were phosphorylated after 5 minutes of reperfusion. Inhibition of PI-3-kinase activity, using wortmannin, decreased phosphorylation on both sites during SI. However, only SI/R-induced PKB/Akt phosphorylation on Thr(308) was reduced by wortmannin. Myocytes pre-treated with SB203580, a p38-inhibitor, displayed a significant increase in cell viability [63.67 +/- 1.85 to 84.33 +/- 4.8% (p < 0.05)] and attenuation of the apoptotic index during SI/R [22.6 +/- 2.94% to 9 +/- 0.43% (p < 0.001)], while SP600125, a specific JNK inhibitor, caused a significant increase in caspase-3 activation [1.66 +/- 0.03 fold to 2.56 +/- 0.27 fold (p < 0.001)] and apoptotic index [22.6 +/- 2.94% to 32.75 +/- 6.13% (p < 0.05)]. However, PD98059, an ERK inhibitor, failed to affect apoptosis during SI/R. Inhibition of PI-3-kinase prevented the increase in mitochondrial viability usually observed during reperfusion. Interestingly, wortmannin caused a significant increase in PARP cleavage during reperfusion, but had no effect on caspase-3 activation or the apoptotic index. Our results suggest that p38 has a pro-apoptotic role while JNK phosphorylation is protective in our cell model and that these kinases act via caspase-3 to prevent or promote cell survival in response to SI/R-induced injury.

Overexpression of Bcl-x(L) promotes chemotherapy resistance of mammary tumors in a syngeneic mouse model

Bcl-x(L), a prosurvival member of the Bcl-2 family that is expressed in many tumors, represses apoptosis induced by chemotherapeutic drugs in vitro. However, the contribution of apoptosis and prosurvival Bcl-2-related proteins to chemotherapy resistance in vivo is unknown and has been challenged by recent results with clonogenic survival assays. To test the ability of Bcl-x(L) to provide chemotherapy resistance to tumors, we transfected the mouse bcl-x(L) gene into the tumorigenic SCK mammary cell line and assessed the response of tumor cells to chemotherapeutic drugs in clonogenic assays and in a syngeneic mouse model. Bcl-x(L) conferred protection on SCK cells against methotrexate at certain drug concentrations, but not at all against 5-fluorouracil in clonogenic survival assays in vitro. Injection of SCK cells transfected with Bcl-x(L) or control plasmid in the mammary fat pads of syngeneic recipient mice resulted in tumors of similar size. However, although the volume of control tumors regressed up to 80% after 4 to 5 days of chemotherapy, SCK tumors expressing Bcl-x(L) did not regress and continued to grow in the presence of methotrexate or 5-fluorouracil. In addition, numbers of apoptotic cells were significantly higher in control tumors as compared to Bcl-x(L)-expressing tumors in animals treated with methotrexate or 5-fluorouracil. These results provide evidence that inhibition of apoptosis through Bcl-x(L) overexpression can promote resistance to chemotherapy in tumors in vivo.

Chloroform Cometabolism by Butane-Grown CF8, Pseudomonas butanovora, and Mycobacterium vaccae JOB5 and Methane-Grown Methylosinus trichosporium OB3b

Chloroform (CF) degradation by a butane-grown enrichment culture, CF8, was compared to that by butane-grown Pseudomonas butanovora and Mycobacterium vaccae JOB5 and to that by a known CF degrader, Methylosinus trichosporium OB3b. All three butane-grown bacteria were able to degrade CF at rates comparable to that of M. trichosporium. CF degradation by all four bacteria required O(inf2). Butane inhibited CF degradation by the butane-grown bacteria, suggesting that butane monooxygenase is responsible for CF degradation. P. butanovora required exogenous reductant to degrade CF, while CF8 and M. vaccae utilized endogenous reductants. Prolonged incubation with CF resulted in decreased CF degradation. CF8 and P. butanovora were more sensitive to CF than either M. trichosporium or M. vaccae. CF degradation by all three butane-grown bacteria was inactivated by acetylene, which is a mechanism-based inhibitor for several monooxygenases. Butane protected all three butane-grown bacteria from inactivation by acetylene, which indicates that the same monooxygenase is responsible for both CF and butane oxidation. CF8 and P. butanovora were able to degrade other chlorinated hydrocarbons, including trichloroethylene, 1,2-cis-dichloroethylene, and vinyl chloride. In addition, CF8 degraded 1,1,2-trichloroethane. The results indicate the potential of butane-grown bacteria for chlorinated hydrocarbon transformation.

Bcl-xL is expressed in ovarian carcinoma and modulates chemotherapy-induced apoptosis

OBJECTIVE

To investigate the role of Bcl-xL in resistance to chemotherapy-induced apoptosis in ovarian carcinoma.

METHODS

Two human ovarian carcinoma cell lines were used in this study: A2780 and SKOV3. A2780 cells were transfected with human Bcl-xL or control plasmid alone. Expression of Bcl-xL in single cell clones was analyzed by flow cytometry and protein expression was confirmed by Western blot. For in vitro chemotherapy-induced death assays, cisplatin and Taxol were used. The percentage of apoptotic cells was determined by nuclear propidium iodide staining followed by flow cytometric analysis. Human ascites samples were used to make tumor lysates which were then analyzed for expression of Bcl-xL protein by Western blot.

RESULTS

A2780 cells express low levels of endogenous Bcl-xL while SKOV3 cells express high amounts as determined by Western blot. In addition, A2780 cells are sensitive to chemotherapy-induced cell death while SKOV3 cells are resistant. To determine if chemoresistance is mediated by expression of Bcl-xL, A2780 cells were transfected with Bcl-xL or control plasmid. Cells were incubated with either cisplatin or Taxol to induce apoptosis. Bcl-xL-expressing cells were highly resistant to cisplatin and Taxol compared with controls (P < 0.05). All samples of malignant ascites analyzed expressed high levels of Bcl-xL on Western blot.

CONCLUSIONS

The results of these studies indicate that Bcl-xL is expressed in ovarian carcinoma, and in A2780 cells functions in a manner analogous to Bcl-2 by inhibiting chemotherapy-induced apoptosis. This may have prognostic significance; previous studies have demonstrated that patients with breast cancer that overexpress Bcl-2 have low-grade, hormonally responsive tumors. In ovarian carcinoma, another Bcl-2 family member, Bcl-xL may be responsible for modulating resistance to chemotherapy-induced apoptosis.

ACCORD: A Multicentre, Seamless, Phase 2 Adaptive Randomisation Platform Study to Assess the Efficacy and Safety of Multiple Candidate Agents for the Treatment of COVID-19 in Hospitalised Patients: A structured summary of a study protocol for a randomised controlled trial

OBJECTIVES

Stage 1: To evaluate the safety and efficacy of candidate agents as add-on therapies to standard of care (SoC) in patients hospitalised with COVID-19 in a screening stage. Stage 2: To confirm the efficacy of candidate agents selected on the basis of evidence from Stage 1 in patients hospitalised with COVID-19 in an expansion stage.

TRIAL DESIGN

ACCORD is a seamless, Phase 2, adaptive, randomised controlled platform study, designed to rapidly test candidate agents in the treatment of COVID-19. Designed as a master protocol with each candidate agent being included via its own sub-protocol, initially randomising equally between each candidate and a single contemporaneous SoC arm (which can adapt into 2:1). Candidate agents currently include bemcentinib, MEDI3506, acalabrutinib, zilucoplan and nebulised heparin. For each candidate a total of 60 patients will be recruited in Stage 1. If Stage 1 provides evidence of efficacy and acceptable safety the candidate will enter Stage 2 where a total of approximately 126 patients will be recruited into each study arm sub-protocol. Enrollees and outcomes will not be shared across the Stages; the endpoint, analysis and sample size for Stage 2 may be adjusted based on evidence from Stage 1. Additional arms may be added as new potential candidate agents are identified via candidate agent specific sub-protocols.

PARTICIPANTS

The study will include hospitalised adult patients (≥18 years) with confirmed SARS-CoV-2 infection, the virus that causes COVID-19, that clinically meet Grades 3 (hospitalised - mild disease, no oxygen therapy), Grades 4 (hospitalised, oxygen by mask or nasal prongs) and 5 (hospitalised, non-invasive ventilation or high flow oxygen) of the WHO Working Group on the Clinical Characteristics of COVID-19 9-point category ordinal scale. Participants will be recruited from England, Northern Ireland, Wales and Scotland.

INTERVENTION AND COMPARATOR

Comparator is current standard of care (SoC) for the treatment of COVID-19. Current candidate experimental arms include bemcentinib, MEDI3506, acalabrutinib, zilucoplan and nebulised heparin with others to be added over time. Bemcentinib could potentially reduce viral infection and blocks SARS-CoV-2 spike protein; MEDI3506 is a clinic-ready anti-IL-33 monoclonal antibody with the potential to treat respiratory failure caused by COVID; acalabrutinib is a BTK inhibitor which is anti-viral and anti-inflammatory; zilucoplan is a complement C5 inhibitor which may block the severe inflammatory response in COVID-19 and; nebulised heparin has been shown to bind with the spike protein. ACCORD is linked with the UK national COVID therapeutics task force to help prioritise candidate agents.

MAIN OUTCOMES

Time to sustained clinical improvement of at least 2 points (from randomisation) on the WHO 9-point category ordinal scale, live discharge from the hospital, or considered fit for discharge (a score of 0, 1, or 2 on the ordinal scale), whichever comes first, by Day 29 (this will also define the "responder" for the response rate analyses).

RANDOMISATION

An electronic randomization will be performed by Cenduit using Interactive Response Technology (IRT). Randomisation will be stratified by baseline severity grade. Randomisation will proceed with an equal allocation to each arm and a contemporaneous SoC arm (e.g. 1:1 if control and 1 experimental arm; 1:1:1 if two experimental candidate arms etc) but will be reviewed as the trial progresses and may be changed to 2:1 in favour of the candidate agents.

BLINDING (MASKING)

The trial is open label and no blinding is currently planned in the study.

NUMBERS TO BE RANDOMISED (SAMPLE SIZE)

This will be in the order of 60 patients per candidate agent for Stage 1, and 126 patients for Stage 2. However, sample size re-estimation may be considered after Stage 1. It is estimated that up to 1800 patients will participate in the overall study.

TRIAL STATUS

Master protocol version ACCORD-2-001 - Master Protocol (Amendment 1) 22nd April 2020, the trial has full regulatory approval and recruitment is ongoing in the bemcentinib (first patient recruited 6/5/2020), MEDI3506 (first patient recruited 19/5/2020), acalabrutinib (first patient recruited 20/5/2020) and zilucoplan (first patient recruited 19/5/2020) candidates (and SoC). The recruitment dates of each arm will vary between candidate agents as they are added or dropped from the trial, but will have recruited and reported within a year.

TRIAL REGISTRATION

EudraCT 2020-001736-95 , registered 28th April 2020.

FULL PROTOCOL

The full protocol (Master Protocol with each of the candidate sub-protocols) is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Low-dose theophylline modulates T-lymphocyte activation in allergen-challenged asthmatics

Theophylline has been shown by several investigators to attenuate the late asthmatic response (LAR) to inhaled allergen, suggesting that it has anti-inflammatory or immunomodulatory properties. We have, therefore, undertaken a double-blind, placebo-controlled study to examine the effects of low-dose theophylline on bronchoalveolar lavage (BAL) and blood T-lymphocyte profile and activation in asthmatics following antigen challenge and the development of a LAR. Peripheral blood and BAL samples were obtained from 17 subjects with mild atopic asthma before and after 6 weeks of treatment with either oral theophylline or placebo. The mean serum theophylline concentration achieved was 6.6 micrograms.mL-1, which is below the currently accepted therapeutic range. Following theophylline therapy, there was a significant decrease in the number of BAL lymphocytes compared to placebo. On flow cytometric analysis of BAL cells, a significant loss of CD3+ T-lymphocytes, comprising both CD4+ and CD8+ subsets, was demonstrated. Moreover, there was a decrease in the number of BAL CD4+ T-cells expressing the activation marker very late activation antigen-1 (VLA-1), and an apparent reduction in human leucocyte antigen-DR (HLA-DR). Correspondingly, this was accompanied in the blood by an elevation in the proportion of activated CD4+ T-lymphocytes, in particular those expressing HLA-DR. These findings provide further evidence that theophylline has an anti-inflammatory action in asthma.

Role of platelets in allergic airway inflammation

Increasing evidence suggests an important role for platelets and their products (e.g., platelet factor 4, β-thromboglobulin, RANTES, thromboxane, or serotonin) in the pathogenesis of allergic diseases. A variety of changes in platelet function have been observed in patients with asthma, such as alterations in platelet secretion, expression of surface molecules, aggregation, and adhesion. Moreover, platelets have been found to actively contribute to most of the characteristic features of asthma, including bronchial hyperresponsiveness, bronchoconstriction, airway inflammation, and airway remodeling. This review brings together the current available data from both experimental and clinical studies that have investigated the role of platelets in allergic airway inflammation and asthma. It is anticipated that a better understanding of the role of platelets in the pathogenesis of asthma might lead to novel promising therapeutic approaches in the treatment of allergic airway diseases.

Heparin and related drugs: beyond anticoagulant activity

Heparin has been widely used as an anticoagulant for more than 80 years. However, there is now considerable evidence that heparin also possesses anti-inflammatory activity, both experimentally and clinically. Importantly in many instances, the anti-inflammatory actions of heparin are independent of anticoagulant activity raising the possibility of developing novel drugs based on heparin that retain the anti-inflammatory activity. Heparin exhibits anti-inflammatory activities via a variety of mechanisms including neutralization of cationic mediators, inhibition of adhesion molecules, and the inhibition of heparanase, all involved in leukocyte recruitment into tissues. It is anticipated that furthering our understanding of the anti-inflammatory actions of heparin will lead to the development of novel anti-inflammatory drugs for a variety of clinical indications.