Polybacterial aetiology and outcomes in patients with community-acquired pneumonia

SETTING

Community-acquired pneumonia (CAP) is a common cause of morbidity and mortality worldwide. While interactions among bacterial pathogens in the respiratory tract have been studied, the impact of polybacterial aetiology on mortality has not been fully elucidated.

OBJECTIVE

To investigate the impact of polybacterial aetiology on mortality, prevalence, microbial patterns and clinical characteristics among CAP patients.

DESIGN

Retrospective data analysis.

RESULTS

Bacterial aetiology was established in 711 (46.0%) of 1544 enrolled hospitalised CAP patients. Of these, polybacterial aetiology was identified in 89 (12.5%): Streptococcus pneumoniae was the most frequently identified pathogen (n = 55, 61.8%). The most prevalent microbial combination was S. pneumoniae and Haemophilus influenzae (n = 19, 21.3%). Alcoholism and lack of previous antibiotic therapy were independent predictors of polybacterial aetiology. The proportion of patients with severe pneumonia was significantly higher in the polybacterial aetiology group than in the monobacterial group. Multivariate analysis showed that polybacterial aetiology was a predictor of 30-day mortality (OR 2.14, 95%CI 1.07-4.24, P = 0.030), independently of severe pneumonia status, pneumonia severity index, chronic obstructive pulmonary disease and inappropriate empirical therapy.

CONCLUSION

Polybacterial CAP tends to advance in severity, and indicates adverse outcomes.

CT Findings of Endobronchial Metastasis

One hundred and sixty-one patients with pulmonary metastases were studied with CT. Six of them proved to have endobronchial (intraluminal) metastatic lesions by bronchoscopy. Retrospective analysis of the CT studies showed obstruction and/or narrowing of the bronchi in 5 cases while no lesion was observed in one patient. Although CT can not always demonstrate intraluminal lesions, it should be performed when an endobronchial metastasis from extrathoracic malignancy is seen by bronchoscopy because it will show hilar or mediastinal lymphadenopathy, or single or multiple pulmonary metastases other than the endobronchial lesion.

Optimization of steroid injection intervals for prevention of stricture after esophageal endoscopic submucosal dissection: A randomized controlled trial

BACKGROUND

Esophageal endoscopic submucosal dissection enables en bloc resection of large superficial esophageal cancer; however, this procedure may induce severe stricture. Intralesional steroid injection is an effective treatment for prevention of stricture after endoscopic resection; however, there have been no studies assessing the duration of such treatment. The aim of this study was to reduce treatment duration and to evaluate the effectiveness of weekly and biweekly steroid injections in preventing esophageal stricture after endoscopic resection.

PATIENTS METHOD

We performed a randomized controlled trial comparing patients receiving weekly or biweekly intralesional triamcinolone injections. Patients with a mucosal defect greater than 75% (3/4) of the luminal circumference after esophageal endoscopic submucosal dissection for superficial esophageal cancers were enrolled. The primary endpoint was the duration of steroid injection treatment.

RESULTS

The median duration of treatment was 37.0 days in the weekly group and 34.2 days in the biweekly group (P = 0.059). Among patients with a mucosal defect larger than 50 mm, there was a significant difference in the median duration of treatment between the weekly and biweekly groups (42.5 days vs 29.0 days, P = 0.013).

CONCLUSION

Biweekly steroid injection of triamcinolone reduces treatment duration, particularly in those with mucosal defects larger than 50 mm. (Acta gastro-enterol. belg., 2016, 79, 315-320).

A New Inductive Applicator for Hyperthermia

We have designed a new type of applicator for inductive heating which consists of a one-turn, square, column-like coil, through which RF current flows. The material to be heated is placed alongside one of the external sides of the coil. The depth of penetration from an applicator with a height of 20 cm, width of 20 cm, depth of 60 cm was calculated to be 11.7 cm. However, in experiments using a muscle-equivalent agar phantom 60 cm X 60 cm X 60 cm, the penetration depth proved to be 9.6 cm; but in another experiment using a smaller phantom 20 cm X 40 cm X 60 cm, the penetration depth was 6.3 cm. This means that the depth of penetration depends not only on the size of the applicator but also on the shape of the material heated. Our study clearly showed that this applicator produces much less heat in the fat layer than in the muscle layer and should be an inductive applicator suitable for deep heating cancer therapy.

Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K.

Site-selective nanoscale-polymerization of pyrrole on gold nanoparticles via plasmon induced charge separation

We proposed a nanoscale oxidative polymerization method which enables site-selective deposition on the surface of gold nanoparticles (AuNPs) combined with TiO2 by using plasmon induced charge separation (PICS) under visible-to-near infrared (IR) light irradiation. The method also revealed that the anodic site of PICS was located at the surface of AuNPs.

Coordinated loss of microRNA group causes defenseless signaling in malignant lymphoma

Biological robustness is exposed to stochastic perturbations, which should be controlled by intrinsic mechanisms; the promiscuous signaling network without appropriate alleviation is the true nature of cancer cells. B cell receptor (BCR) signaling is a major source of gene expression signature important for B cell. It is still unclear the mechanism by which the expression of functionally important genes is continuously deregulated in malignant lymphomas. Using RISC-capture assay, we reveal that multiple BCR signaling factors are persistently regulated by microRNA (miRNA) in human B cells. Clinical samples from patients with diffuse large B-cell lymphoma (DLBCL, n = 83) show loss of an essential miRNA set (miR-200c, miR-203, miR-31). Conventional screening and RISC profiling identify multiple targets (CD79B, SYK, PKCβII, PLCγ1, IKKβ, NIK, MYD88, PI3K class I (α/β/δ/γ), RasGRP3); signaling network habitually faces interference composed by miRNA group in normal B cells. We demonstrate that simultaneous depletion of the key miRNAs enhances translation of the multiple targets and causes chronic activation of NF-κB, PI3K-Akt, and Ras-Erk cascades, leading to B cell transformation. This study suggests that compensatory actions by multiple miRNAs rather than by a single miRNA ensure robustness of biological processes.

Lower expression of activating transcription factors 3 and 4 correlates with shorter progression-free survival in multiple myeloma patients receiving bortezomib plus dexamethasone therapy

Bortezomib (BTZ), a proteasome inhibitor, is widely used in the treatment of multiple myeloma (MM), but a fraction of patients respond poorly to this agent. To identify factors predicting the duration of progression-free survival (PFS) of MM patients on BTZ treatment, the expression of proteasome and endoplasmic reticulum (ER) stress-related genes was quantified in primary samples from patients receiving a combination of BTZ and dexamethasone (BD). Fifty-six MM patients were stratified into a group with PFS<6 months (n=33) and a second group with PFS⩾6 months (n=23). Of the 15 genes analyzed, the expression of activating transcription factor 3 (ATF3) and ATF4 was significantly lower in patients with shorter PFS (P=0.0157 and P=0.0085, respectively). Chromatin immunoprecipitation analysis showed that these ATFs bind each other and transactivate genes encoding the pro-apoptotic transcription factors, CHOP and Noxa, which promote ER stress-associated apoptosis. When either ATF3 or ATF4 expression was silenced, MM cells partially lost sensitivity to BTZ treatment. This was accompanied by lower levels of Noxa, CHOP and DR5. Thus low basal expression of ATF3 and ATF4 may attenuate BTZ-induced apoptosis. Hence, ATF3 and ATF4 could potentially be used as biomarkers to predict efficacy of BD therapy in patients with MM.

Accumulation of a repulsive axonal guidance molecule RGMa in amyloid plaques: a possible hallmark of regenerative failure in Alzheimer's disease brains

AIMS

RGMa is a repulsive guidance molecule that induces the collapse of axonal growth cones by interacting with the receptor neogenin in the central nervous system during development. It remains unknown whether RGMa plays a role in the neurodegenerative process of Alzheimer's disease (AD). We hypothesize that RGMa, if it is concentrated on amyloid plaques, might contribute to a regenerative failure of degenerating axons in AD brains.

METHODS

By immunohistochemistry, we studied RGMa and neogenin (NEO1) expression in the frontal cortex and the hippocampus of 6 AD and 12 control cases. The levels of RGMa expression were determined by qRT-PCR and Western blot in cultured human astrocytes following exposure to cytokines and amyloid beta (Aβ) peptides.

RESULTS

In AD brains, an intense RGMa immunoreactivity was identified on amyloid plaques and in the glial scar. In the control brains, the glial scar and vascular foot processes of astrocytes expressed RGMa immunoreactivity, while oligodendrocytes and microglia were negative for RGMa. In AD brains, a small subset of amyloid plaques expressed a weak NEO1 immunoreactivity, while some reactive astrocytes in both AD and control brains showed an intense NEO1 immunoreactivity. In human astrocytes, transforming growth factor beta-1 (TGFβ1 ), Aβ 1-40 or Aβ 1-42 markedly elevated the levels of RGMa, and TGFβ1 also increased its own levels. Coimmunoprecipitation analysis validated the molecular interaction between RGMa and the C-terminal fragment β of amyloid beta precursor protein (APP). Furthermore, recombinant RGMa protein interacted with amyloid plaques in situ.

CONCLUSIONS

RGMa, produced by TGFβ-activated astrocytes and accumulated in amyloid plaques and the glial scar, could contribute to the regenerative failure of degenerating axons in AD brains.

A RANKL mutant used as an inter-species vaccine for efficient immunotherapy of osteoporosis

Anti-cytokine therapeutic antibodies have been demonstrated to be effective in the treatment of several auto-immune disorders. However, The problems in antibody manufacture and the immunogenicity caused by multiple doses of antibodies inspire people to use auto-cytokine as immunogen to induce anti-cytokine antibodies. Nevertheless, the tolerance for inducing immune response against self-antigen has hindered the wide application of the strategy. To overcome the tolerance, here we proposed a strategy using the inter-species cytokine as immunogen for active immunization (TISCAI) to induce anti-cytokine antibody. As a proof of concept, an inter-species cytokine RANKL was successfully used as immunogen to induce anti-RANKL immune response. Furthermore, to prevent undesirable side-effects, the human RANKL was mutated based on the crystal structure of the complex of human RANKL and its rodent counterpart receptor RANK. We found, the antibodies produced blocked the osteoclast development in vitro and osteoporosis in OVX rat models. The results demonstrated this strategy adopted is very useful for general anti-cytokine immunotherapy for different diseases settings.

Search for Nucleon and Dinucleon Decays with an Invisible Particle and a Charged Lepton in the Final State at the Super-Kamiokande Experiment

Search results for nucleon decays p→e^{+}X, p→μ^{+}X, n→νγ (where X is an invisible, massless particle) as well as dinucleon decays np→e^{+}ν, np→μ^{+}ν, and np→τ^{+}ν in the Super-Kamiokande experiment are presented. Using single-ring data from an exposure of  273.4  kton·yr, a search for these decays yields a result consistent with no signal. Accordingly, lower limits on the partial lifetimes of τ_{p→e^{+}X}>7.9×10^{32} yr, τ_{p→μ^{+}X}>4.1×10^{32} yr, τ_{n→νγ}>5.5×10^{32} yr, τ_{np→e^{+}ν}>2.6×10^{32}  yr, τ_{np→μ^{+}ν}>2.2×10^{32} yr, and τ_{np→τ^{+}ν}>2.9×10^{31} yr at a 90% confidence level are obtained. Some of these searches are novel.

Emergence of Lamivudine-Resistant HBV during Antiretroviral Therapy Including Lamivudine for Patients Coinfected with HIV and HBV in China

In China, HIV-1-infected patients typically receive antiretroviral therapy (ART) that includes lamivudine (3TC) as a reverse-transcriptase inhibitor (RTI) (ART-3TC). Previous studies from certain developed countries have shown that, in ART-3TC, 3TC-resistant HBV progressively emerges at an annual rate of 15–20% in patients coinfected with HIV-1 and HBV. This scenario in China warrants investigation because >10% of all HIV-infected patients in China are HBV carriers. We measured the occurrence of 3TC-resistant HBV during ART-3TC for HIV-HBV coinfection and also tested the effect of tenofovir disoproxil fumarate (TDF) used as an additional RTI (ART-3TC/TDF) in a cohort study in China. We obtained 200 plasma samples collected from 50 Chinese patients coinfected with HIV-1 and HBV (positive for hepatitis B surface antigen) and examined them for the prevalence of 3TC-resistant HBV by directly sequencing PCR products that covered the HBV reverse-transcriptase gene. We divided the patients into ART-3TC and ART-3TC/TDF groups and compared the efficacy of treatment and incidence of drug-resistance mutation between the groups. HIV RNA and HBV DNA loads drastically decreased in both ART-3TC and ART-3TC/TDF groups. In the ART-3TC group, HBV breakthrough or insufficient suppression of HBV DNA loads was observed in 20% (10/50) of the patients after 96-week treatment, and 8 of these patients harbored 3TC-resistant mutants. By contrast, neither HBV breakthrough nor treatment failure was recorded in the ART-3TC/TDF group. All of the 3TC-resistant HBV mutants emerged from the cases in which HBV DNA loads were high at baseline. Our results clearly demonstrated that ART-3TC is associated with the emergence of 3TC-resistant HBV in patients coinfected with HIV-1 and HBV and that ART-3TC/TDF reduces HBV DNA loads to an undetectable level. These findings support the use of TDF-based treatment regimens for patients coinfected with HIV-1 and HBV.

Impact of bacterial coinfection on clinical outcomes in pneumococcal pneumonia

The aim of this study was to investigate the influence of bacterial coinfection on patients with pneumococcal pneumonia. We retrospectively analyzed the incidence, clinical features, microbial distributions, and outcomes of patients with bacterial coinfection in a cohort of 433 hospitalized patients with pneumococcal pneumonia. Eighty-five patients (19.6 %) were diagnosed with bacterial coinfection; the most frequent pathogens were Haemophilus influenzae (25 patients, 33.3 %), methicillin-susceptible Staphylococcus aureus (MSSA) (15 patients, 20.0 %), and Moraxella catarrhalis (13 patients, 17.3 %). The CURB-65 score and pneumonia severity index (PSI) were significantly higher in patients with bacterial coinfection (both P < 0.001). In addition, the proportion of patients with bacterial coinfection who met the Infectious Disease Society of America (IDSA)/American Thoracic Society (ATS) severe pneumonia criteria was significantly higher (P < 0.001). Multivariate logistic regression analysis identified three risk factors for bacterial coinfection in patients with pneumococcal pneumonia: alcoholism (odds ratio [OR], 5.12; 95 % confidence interval (95 % CI), 1.60-16.4; P = 0.006), hospitalization for 2 days or more within 90 days preceding admission (OR, 2.02; 95 % CI, 1.03-3.98; P = 0.041), and residence in a nursing home or extended care facility (OR, 3.22; 95 % CI, 1.48-6.97; P = 0.003). Multivariate analysis for 30-day mortality showed that bacterial coinfection was a significant adverse prognostic factor (OR, 2.50; 95 % CI, 1.13-5.53; P = 0.023), independent of IDSA/ATS severe pneumonia, PSI, or healthcare-associated pneumonia. In conclusion, bacterial coinfection may have an adverse impact on severity and outcomes of pneumococcal pneumonia.