Influence of Alveolar Fluid on Aquaporins and Na+/K+-ATPase and Its Possible Theoretical or Clinical Significance.

OBJECTIVE: Pulmonary edema is the most common pathophysiological change in pulmonary disease. Aquaporins (AQPs) and Na+/K+-ATPase play pivotal roles in alveolar fluid clearance. This study aimed to explore the influence of increased alveolar fluid on the absorption of lung fluid. STUDY DESIGN: Eighty New Zealand rabbits were randomly divided into eight groups (n = 10 in each group), and models of different alveolar fluid contents were established by the infusion of different volumes of normal saline (NS) via the endotracheal tube. Five animals in each group were sacrificed immediately after infusion to determine the wet/dry ratio, while the remaining animals in each group were killed 4 hours later to determine the wet/dry ratio at 4 hours. Additionally, lung specimens were collected from each group, and quantitative real-time PCR (qRT-PCR), western blot, and immunohistochemical (IHC) analyses of AQPs and Na+/K+-ATPase were performed. RESULTS: The qRT-PCR analysis and western blot studies showed markedly decreased mRNA and protein levels of AQP1 and Na+/K+-ATPase when the alveolar fluid volume was ≥6 mL/kg, and the mRNA level of AQP5 was significantly reduced when the alveolar fluid volume was ≥4 mL/kg. In addition, IHC analysis showed the same results. At 4 hours, the lung wet/dry ratio was significantly increased when the alveolar fluid volume was ≥6 mL/kg; however, compared with 0 hours after NS infusion, there was still a significant absorption of alveolar fluid for a period of 4 hours. CONCLUSION: The results of this study suggest that increased alveolar fluid may induce the downregulation of the mRNA and protein expression of AQPs and Na+/K+-ATPase, which appear to affect alveolar fluid clearance in rabbit lungs. Early intervention is required to avoid excessive alveolar fluid accumulation. KEY POINTS: · The expression levels of AQPs and Na+/K+--ATPase were significantly decreased as alveolar fluid increased.. · At 4 hours, wet/dry ratio was significantly increased when infusion volume was ≥ 6 mL/kg.. · Early intervention is required to avoid excessive alveolar fluid accumulation..

Anti-Influenza Virus (H5N1) Activity Screening on the Phloroglucinols from Rhizomes of Dryopteris crassirhizoma.

For screening the active phloroglucinols on influenza virus (H5N1) from Dryopteris crassirhizoma NaKai, a database was established including twenty-three phloroglucinols that had been isolated from Dryopteris crassirhizoma. Their inhibitory effect on the neuraminidase (NA) of influenza virus H5N1 was screened by molecular docking. As a result, three candidates were selected. The rhizomes of D. crassirhizoma were subjected to isolation and purification processes to obtain the inhibitor candidates. Thirteen phloroglucinols were obtained, including three selected candidates and two new phloroglucinols. The five phloroglucinols were investigated for their inhibitory activity on NA in vitro. The results showed that dryocrassin ABBA and filixic acid ABA exhibited inhibitory effects on NA with IC50 as 18.59 ± 4.53 and 29.57 ± 2.48 µM, respectively, and the other three phloroglucinols showed moderate inhibitory activity. Moreover, the anti-influenza virus (H5N1) activity and cytotoxicity of dryocrassin ABBA and filixic acid ABA were tested on Madin-Darby canine kidney (MDCK) cells with the cell counting kit-8 (CCK8) method. The results confirmed that dryocrassin ABBA exhibited an inhibitory activity with low cytotoxicity (TC50 > 400 µM) against influenza virus (H5N1) which will have to be investigated in further detail. In conclusion, phloroglucinols from D. crassirhizoma were shown to have anti-influenza virus activity, and especially dryocrassin ABBA, one of the phloroglucinols, may have the potential to control influenza virus (H5N1) infection.

Emergence of an ancient and pathogenic mammarenavirus.

Emerging zoonoses of wildlife origin caused by previously unknown agents are one of the most important challenges for human health. The Qinghai-Tibet Plateau represents a unique ecological niche with diverse wildlife that harbours several human pathogens and numerous previously uncharacterized pathogens. In this study, we identified and characterized a novel arenavirus (namely, plateau pika virus, PPV) from plateau pikas (Ochotona curzoniae) on the Qinghai-Tibet Plateau by virome analysis. Isolated PPV strains could replicate in several mammalian cells. We further investigated PPV pathogenesis using animal models. PPV administered via an intraventricular route caused trembling and sudden death in IFNαßR-/- mice, and pathological inflammatory lesions in brain tissue were observed. According to a retrospective serological survey in the geographical region where PPV was isolated, PPV-specific IgG antibodies were detected in 8 (2.4%) of 335 outpatients with available sera. Phylogenetic analyses revealed that this virus was clearly separated from previously reported New and Old World mammarenaviruses. Under the co-speciation framework, the estimated divergence time of PPV was 77-88 million years ago (MYA), earlier than that of OW and NW mammarenaviruses (26-34 MYA).

[Effectiveness of Ganoderma lucidum preparation in treating simian acquired immune deficiency syndrome].

OBJECTIVE: To explore the effectiveness of the traditional Chinese herbal medicine Lingzhi (Ganoderma lucidum) preparation in treating simian acquired immune deficiency syndrome (SAIDS). METHODS: Five female adult Chinese rhesus monkeys were inoculated rectally with SIVmac239, and were all diagnosed as SAIDS by laboratory and clinical examinations 17 months later. Of these 5 monkeys, 3 (#393, #374, and #381; treatment group) were orally administered with Ganoderma lucidum (2 spores powder capsules plus 2 spores oil capsules on a daily basis), and the remaining other two monkeys (#348 and #361) served as control and did not receive treatment. RESULTS: Animal #393 (treatment group), #361 (control group) and #348 (control group) died of SAIDS (opportunity infection) 3.5 months, 6 months, and 11 months later, respectively. Two animals (#374 and #381) survived. The necropsy revealed depletion and/or exhaustion of their lymphoid tissue. In the monkey #374, the peripheral CD4(+) T lymphocyte increased by 30% in the 6(th) month compared with the baseline level and then fluctuated. The plasma viral load gradually fell and reached about 1 log(10) in the treatment group, but remained stable in the control group. As shown by pathological examinations, the lymph node and spleen of monkeys #374 (treatment group) and #381 (treatment group) showed rehabilitation and reconstruction in the lymphatic tissue, thymus, nerve tissue of gyrus hippocampi, pituitary gland, pineal body, thyroid gland, adrenal gland, and ovary. In the control group, however, animals experienced depletion of lymph nodes, atrophy of spleen, disappearance of thymus, and other disorders in endocrine organs. CONCLUSION: Ganoderma lucidum preparation may have certain protective effect on the immune system, nervous system, and endocrine system of monkeys with SAIDS.

Wet lung leading to RDS: the lung ultrasound findings and possible mechanisms - a pilot study from an animal mode.

BACKGROUND: Clinically, the lung ultrasound (LUS) showed wet lung could cause respiratory distress syndrome (RDS) in newborns. This work aimed to investigate LUS changes over time and its potential mechanism as alveolar fluid increase in a rabbit model. METHODS: A total of 35 New Zealand Rabbits were randomly assigned to seven groups. Models of various alveolar fluid levels were induced by infusion of different volumes of normal saline (NS) via the endotracheal tube. LUS was performed before NS infusion, immediately after NS infusion and 4 h after NS infusion. To appraise LUS changes and its potential mechanism as alveolar fluid increase, histopathological examination, the mRNA and protein expression of surfactant protein (SP), and immunohistochemistry (IHC) were performed. The expression levels of SP-B and SP-C proteins were detected using western blotting, and the relative expression levels of SP-B and SP-C mRNA were detected using qRT-PCR. RESULTS: The results showed that LUS changed from B-line to lung consolidations accompanied by air-bronchograms in some locations of lungs at 4 h when the injection volume ≥ 6 ml/kg. Histopathological examination showed alveoli collapse, inflammatory cell infiltration and alveolar wall thickened. SP-B and SP-C mRNA and protein expression were statistically significantly reduced when the injection volume ≥6 ml/kg (p < .05). IHC staining displayed the same findings. CONCLUSIONS: As alveolar fluid increase, LUS changed from wet lung to RDS after 4 h. The possible mechanism was that the SP protein expression was significantly reduced. LUS can be used to guide the administration of exogenous surfactant in this situation.

Using lung ultrasound to quantitatively evaluate pulmonary water content.

BACKGROUND: Increases in extravascular lung water (EVLW) can lead to respiratory failure. This study aimed to investigate whether the B-line score (BLS) was correlated with the EVLW content determined by the lung wet/dry ratio in a rabbit model. METHODS: A total of 45 New Zealand rabbits were randomly assigned to nine groups. Among the animals, models of various lung water content levels were induced by the infusion of different volumes of warm sterile normal saline (NS) via the endotracheal tube. The arterial blood gas, spontaneous respiratory rate, and PaO2 /FiO2 ratio were detected before and after infusion. In addition, the B-lines were determined before and immediately after infusion in each group. Finally, both lungs were resected to determine the wet/dry ratio. In addition, all lung specimens were analyzed histologically, and EVLW was quantified using the BLS based on the number and confluence of B-lines in the intercostal space. RESULTS: The BLS increased with increasing infusion volume. The BLS was statistically correlated with the wet/dry ratio (r2 = .946) and with the PaO2 /FiO2 ratio (r2 = .916). Furthermore, a repeatability study was performed for the lung ultrasound (LUS) technology (Bland-Altman plots), and the results suggest that LUS had favorable intraobserver and interobserver reproducibility. CONCLUSIONS: This study is the first to suggest that the BLS can serve as a sensitive, quantitative, noninvasive, and real-time indicator of EVLW in a rabbit model of lung water accumulation. Notably, the BLS displayed an obvious correlation with the experimental gravimetry results and could also be used to predict the pulmonary oxygenation status.

Influence of organic loading rate on purified terephthalic acid wastewater treatment in a temperature staged anaerobic treatment (TSAT) system: Performance and metagenomic characteristics.

In this study, a temperature staged anaerobic treatment (TSAT) system featured by thermophilic reactor (R1)-mesophilic reactor (R2) co-digestion was introduced to treat PTA wastewater. The process was successively conducted at three organic loading rates (OLRs): 3.34, 4.45, 6.68 kg COD/(m³·d), respectively (OLRs were R1 basis). The results indicated that TSAT system was highly efficient in PTA wastewater treatment at OLR lower than 4.45 kg COD/(m³·d). Miseq sequencing analysis demonstrated that R1 and R2 were predominated by hydrogenotrophic Methanolinea and acetotrophic Methanosaeta, separately. In addition, TA06, Caldisericia and Acetothermia associated groups were highly abundant in R1, whereas Chlorobiaceae and Syntrophobacteraceae were largely observed in R2. Tax4Fun analysis suggested that the important functional capabilities were significantly different between R1 and R2 (P < 0.05). The pathways related to aromatic compounds degradation mainly occurred in mesophilic stage, while the biosynthesis and metabolism pathways were more favored in thermophilic stage.

The battle against SARS and MERS coronaviruses: Reservoirs and Animal Models.

In humans, infection with the coronavirus, especially the severe acute respiratory syndrome coronavirus (SARS-CoV) and the emerging Middle East respiratory syndrome coronavirus (MERS-CoV), induces acute respiratory failure, resulting in high mortality. Irregular coronavirus related epidemics indicate that the evolutionary origins of these two pathogens need to be identified urgently and there are still questions related to suitable laboratory animal models. Thus, in this review we aim to highlight key discoveries concerning the animal origin of the virus and summarize and compare current animal models.

Phosphorus accumulation by bacteria isolated from a continuous-flow two-sludge system.

In this article, polyphosphate-accumulating organisms (PAOs) from a lab-scale continuous-flow two-sludge system was isolated and identified, the different phosphorus accumulation characteristics of the isolates under anoxic and aerobic conditions were investigated. Two kinds of PAOs were both found in the anoxic zones of the two-sludge system, one of them utilized only oxygen as electron acceptor, and the other one utilized either nitrate or oxygen as electron acceptor. Of the total eight isolates, five isolates were capable of utilizing both nitrate and oxygen as electron acceptors to uptake phosphorus to some extent. And three of the five isolates showed good phosphorus accumulative capacities both under anoxic or aerobic conditions, two identified as Alcaligenes and one identified as Pseudomonas. Streptococcus was observed weak anoxic phosphorus accumulation because of its weak denitrification capacity, but it showed good phosphorus accumulation capacity under aerobic conditions. One isolates identified as Enterobacteriaceae was proved to be a special species of PAOs, which could only uptake small amounts of phosphorus under anoxic conditions, although its denitrification capacity and aerobic phosphorus accumulation capacity were excellent.

Simultaneous phosphorus and nitrogen removal in a continuous-flow two-sludge system.

The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs (phosphorus accumulating organisms) in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio (C/N). Furthermore the SRT (sludge retention time) of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%,75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR (bypass sludge flow rate) should be controlled at 0.35 around.

[Nitrogen Removal Performance of Novel HABR Reactor over CANON Process].

The startup of novel hybrid anaerobic baffled reactor (HABR) and the feasibility of completely autotrophic nitrogen removal over nitrite (CANON) process were studied. The reactor was operated by gradually decreasing HRT to improve total nitrogen load. After startup, the change of nitrogen concentrations, conductivity, pH and MLSS was measured along the reactor, and then the microbial morphology and spatial structure of bacteria were defined. The test results indicated several points:under the experimental condition of an average NH4+-N of 40 mg·L-1 in influent, the quick start-up process was successfully achieved by continuous operation within 89 days, and stabilized over 187 days. The average NH4+-N and TN concentrations of effluent were below 2 mg·L-1 and 10 mg·L-1 respectively, the average removal efficiencies of NH4+-N and TN reached above 96% and 83% respectively, and a NRR of 0.15 kg·(m3·d)-1 was obtained. During the stable phase, the concentrations of NH4+-N and TN gradually declined along the reactor, while the concentrations of NO2--N and NO3--N remained constant at relatively lower values. The highest nitrogen removal efficiency of ammonia occurred in compartment 1, and the reason was confirmed by SEM and FISH microbiological analysis that enriched functional bacteria of AOB and AnAOB coexisted in compartment 1.

Triple combinations of neuraminidase inhibitors, statins and fibrates benefit the survival of patients with lethal avian influenza pandemic.

The high mortality of highly pathogenic avian influenza A (H5N1) viruses infection in humans gives rise to considerable concern that it might someday cause another lethal pandemic. At present there is no other effective alternative besides the early and enough administration of neuraminidase inhibitors, which may be crucial for the patient management. However, its efficacy is sometimes limited because of the late administration in some patients especially the seriously ill ones and the continual occurrence of oseltamivir resistant A (H5N1) strains. The specific candidate vaccine are still under development and the practical value of passive immunization is hard to be widely applied because of the scarcity of convalescent human plasma, especially in the early stage of a serious and rapidly progressing pandemic. Statins and fibrates, both of which are used in clinical practice, have anti-inflammatory and immunomodulatory effects and other multiple biologic activities. So we hypothesized that the two immunomodulatory agents may exhibit synergistic effects when they were combined to neuraminidase inhibitors to treat the A (H5N1) viruses infections via inhibiting the production of either the early inflammatory mediators (e.g., many cytokine/chemokine) or the late mediator (e.g., High Mobility Group Box Protein 1), even showing the anti-viral activities with the prevention of the development of antiviral resistance. Therefore, the novel triple combinations may be an optimal management to confront the next lethal influenza pandemic on its very beginning.

[Preventive and therapeutic effects of recombinant IFN-alpha2b nasal spray on SARS-CoV infection in Macaca mulata].

OBJECTIVE: To study the preventive and therapeutic effects of recombinant IFN-alpha2b for nasal spray on SARS-CoV infection in Macaca mulata (rhesus monkey). METHODS: Ten rhesus monkeys were divided into two groups, 5 in interferon group, and 5 in control group. Before and after SARS-CoV attack, the virus was detected in samples such as pharyngeal swab in all the two groups by Real-time PCR (RT-PCR) and virus isolation was performed. RESULTS: After virus attack, the level of SARS-CoV-specific IgG and neutralizing antibody were induced by SARS-CoV in the interferon group was weaker than in control group. Hematology items showed no apparent changes after virus attack in treated group. Through pathological examination, the morphology of the lung tissues of two Macaques in the treated group was normal, while the other three displayed the interstitial pneumonia with the thickened septum and infiltration with mononuclear cells. Among which, one monkey showed part of thickened septum fused with each other. These lesions in the interferon treated animals were similar to those seen in the animals in control group, but with smaller scope of pathological changes. No significant abnormity was detected in other organs. CONCLUSION: Recombinant IFN-alpha2b could effectively interdict or weaken SARS-CoV injury in monkeys.