Contribution of microbial necromass to soil organic carbon formation during litter decomposition under incubation conditions.

We conducted a 512-day incubation experiment to study the dynamics of microbial necromass and soil carbon fraction in the 'litter-soil' transformation interface soil layer (TIS) during litter decomposition, using a perennial C3 herb, Stipa bungeana, in the loess hills. The results showed that soil microbial necromass was dominated by fungi in the early and middle stages, and by bacteria in the late stage. The contribution of fungal necromass C to mineral-associated organic C (MAOC) was significantly higher (38.7%-75.8%) than that of bacteria (9.2%-22.5%) and 2-3 times more than the contribution rate of bacterial necromass. Soil organic C (SOC) content was decreasing during litter decomposition. The input of plant C resources stimulated microbial utilization of soil C fractions. The continuous decrease in particulate organic C during the early and late stages of decomposition was directly responsible for the decrease in SOC content. In contrast, the fluctuating changes in microbial necromass C and MAOC played an indirect role in the reduction of SOC. The increase in soil microbial necromass C caused by a single exogenous addition of litter did not directly contribute to SOC accumulation.

Environmental Monitoring of Parvovirus B19 in the Kidney Transplantation Ward of a Chinese Teaching Hospital.

Purpose: Parvovirus B19 (B19V) infection is a viral threat after kidney transplantation. It is mainly transmitted by close-contact inhalation of aerosolized viral particles. The risk of nosocomial spread of B19V in the transplantation ward is quite high. This study aimed to evaluate the quality of routine disinfection and the effectiveness of isolation measures in the wards of B19V-infected kidney transplant recipients. Patients and Methods: Throat swab samples of 19 kidney transplant recipients admitted to the isolation ward and three healthcare workers (HCWs) were collected for viral DNA detection. Routine disinfection procedures were performed twice a day in general and B19V isolation wards. Environmental surface and air samples were collected for viral DNA detection before and after disinfection. Results: A total of four patients were diagnosed with B19V infection and transferred to the B19V isolation ward, of which only two had positive throat swab samples. The other 15 patients and all HCWs tested negative for B19V. A total of 88 environmental surface and air samples were collected. Eight of the environmental samples collected in the B19V isolation ward before disinfection tested positive for B19V, while one sample tested positive after disinfection. In the general wards, all environmental samples collected before disinfection tested negative for B19V. All 24 samples collected from ambient air, whether in B19V isolation or general wards, before or after disinfection, tested negative for B19V. Conclusion: Existing methods of routine or terminal disinfection for air and object surfaces were effective in eliminating B19V from object surfaces and ambient air in the isolation and general wards. Material surfaces that are exposed to high frequency and easily contaminated by blood, body fluids, and indoor air were the focus of cleaning and disinfection. Nosocomial cross-infection of other immunocompromised patients and HCWs can be avoided if appropriate prevention and control measures are taken.

Successful Treatment of Severe Post-craniotomy Meningitis Caused by an Escherichia coli Sequence Type 410 Strain Coharboring bla NDM - 5 and bla CTX - M - 65.

Intracranial infections caused by multidrug-resistant Gram-negative bacterium have led to considerable mortality due to extremely limited treatment options. Herein, we firstly reported a clinical carbapenem-resistant Escherichia coli isolate coharboring bla NDM - 5 and bla CTX - M - 65 from a patient with post-craniotomy meningitis. The carbapenem-resistant Escherichia coli strain CNEC001 belonging to Sequence Type 410 was only susceptible to amikacin and tigecycline, both of which have poor penetration through the blood-brain barrier (BBB). The bla CTX - M - 65 gene was expressed on a 135,794 bp IncY plasmid. The bla NDM - 5 gene was located on a genomic island region of an IncX3-type plasmid pNDM5-CNEC001. Based on the characteristics of the strain, we presented the successful treatment protocol of intravenous (IV) tigecycline and amikacin combined with intrathecal (ITH) amikacin in this study. Intracranial infection caused by Escherichia coli coharboring bla NDM - 5 and bla CTX - M - 65 is rare and fatal. Continuous surveillance and infection control measures for such strain need critical attention in clinical settings.

A fatal case of Exophiala dermatitidis meningoencephalitis in an immunocompetent host: A case report and literature review.

BACKGROUND: Central nervous system (CNS) infection due to Exophiala dermatitidis is rare and fatal, and primarily reported in immunocompromised patients or those with caspase recruitment domain-containing protein 9 deficiency. Herein, we describe a case of an otherwise healthy person (without underlying disease or gene deficiency) diagnosed with Exophiala dermatitidis meningoencephalitis. The patient achieved clinical remission under high-dose antifungal therapy in the first 14 months but died after 2 years of the therapy. CASE PRESENTATION: A 15-year-old student with headache and fever was admitted to our department. Lumbar puncture showed increased cerebrospinal fluid (CSF) pressure, moderately high CSF protein levels and cell counts, and a remarkable decrease in CSF glucose and chloride. Magnetic resonance imaging of the brain revealed multiple lesions and cerebral pia mater enhancement. CSF culture confirmed E. dermatitidis infection. We administered 4-week antifungal therapy of amphotericin B, but his CSF culture remained positive. After receiving the 12-week standard dose of voriconazole (200 mg q12h), the patient's CSF culture became negative, but his condition deteriorated with intracranial lesion enlargement. We administered a high-dose voriconazole therapy (600-800 mg per day) for 12 months, which led to clinical remission. The voriconazole dose was reduced due to adverse effects including hepatic dysfunction and hypokalemia, and the disease progressed with high intracranial pressure and epileptic seizures. CONCLUSIONS: CNS infection caused by E. dermatitidis is fatal and the most serious form of fungal infection. Initially, high-dose and long-term antifungal therapy could be effective. Gene defect and related antifungal immunodeficiency may be the most important pathogenic and lethal factor.

Differentiating total from subtotal arterial occlusion in lower extremities by using reverse attenuation gradient sign in CT angiography.

OBJECTIVES: To investigate the use of reverse attenuation gradient sign (RAGS) in CT angiography (CTA) to differentiate total from subtotal occlusion in lower extremities which poses different challenges for the procedure and carries different prognoses. METHODS: Eighty patients with 91 lesions in the lower extremities were divided into total occlusion (TO) group and subtotal occlusion (SO) group confirmed by digital subtraction angiography. The CT numbers of vascular lumen at the end of lesion (proximal, P) and at the first entrance (distal, D) of the lateral branch were measured and their difference (CT(PD) = CT(P) - CT(D)) of each lesion was calculated. The CT number gradient (G(DP) = 2 * CT(PD)/[CT(P) + CT(D)]) was calculated by dividing the CT number difference by the average CT number of the two points. The existence of RAGS where the CT number at the distal point is higher than that at the proximal point (CT(PD) and G(PD) < 0) was determined and the diagnostic efficacy of using RAGS in CTA for differentiating total from subtotal occlusive lesions in lower extremities was calculated. RESULTS: The SO group had higher CT numbers than the TO group (p < 0.001). More importantly, the SO group had positive CT number gradient (G(PD) > 0), while the gradient was negative (G(PD) < 0) in the TO group. The specificity and sensitivity of using RAGS (G(PD) < 0) in images for diagnosing TO of lower extremity were 97.6% and 92.0%, respectively, and 87.8% and 88.0% using the standard CTA images. CONCLUSION: The use of RAGS in CTA images has high diagnostic accuracy to differentiate TO from SO in lower extremities. KEY POINTS: • Total occlusions often exhibit higher CT number at distal point than at proximal point to the occlusion. • The reverse attenuation gradient sign (RAGS) may be determined using the CT number measurements between the proximal and distal points after occlusion. • RAGS can be used to improve the diagnostic efficiency in CTA to differentiate between total and subtotal occlusions of lower extremity arteries.

Clinical and microbiological characteristics of cryptococcosis at an university hospital in China from 2013 to 2017

ABSTRACT Background: This study aims to explore the epidemiology, clinical profile and strain characteristics of cryptococcosis from 2013 to 2017 in a major teaching hospital in China. Methods: Trends in antifungal drug susceptibility of 217 consecutive non-repetitive cryptococcal isolates collected from patients of an university hospital in China were analyzed between 2013 and 2017. Of those, 98 isolates were conserved for identification by internal transcribed spacer (ITS) sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system. Multilocus sequence typing (MLST) was used to designate molecular types. Clinical characteristics of the 98 patients with cryptococcosis during the period of 2013-2017 were retrospectively evaluated. Results: There was a trend for gradual increase in the MIC range of fluconazole was from 2013 to 2017. The conserved 98 clinical cryptococcal isolates included 97 C. neoformans and one C. gattii, and 90 (91.8%) isolates belonged to ST5 genotype VNI. Out of the 98 patients with cryptococcosis, 28 (28.6%) were HIV-infected and 32 (32.7%) had no underlying diseases. HIV-infected patients had higher mortality than HIV-uninfected patients (28.6% vs 14.3%, p = 0.147). Conclusions: Most of the patients with cryptococcosis were not HIV-infected in this study, while patients with HIV had a higher mortality. Reduced susceptibility to fluconazole was observed among C. neoformans isolates, most of them belonged to ST5 genotype VNI having an impact on the effective dose of fluconazole.

Clinical and microbiological characteristics of cryptococcosis at an university hospital in China from 2013 to 2017.

BACKGROUND: This study aims to explore the epidemiology, clinical profile and strain characteristics of cryptococcosis from 2013 to 2017 in a major teaching hospital in China. METHODS: Trends in antifungal drug susceptibility of 217 consecutive non-repetitive cryptococcal isolates collected from patients of an university hospital in China were analyzed between 2013 and 2017. Of those, 98 isolates were conserved for identification by internal transcribed spacer (ITS) sequencing and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) system. Multilocus sequence typing (MLST) was used to designate molecular types. Clinical characteristics of the 98 patients with cryptococcosis during the period of 2013-2017 were retrospectively evaluated. RESULTS: There was a trend for gradual increase in the MIC range of fluconazole was from 2013 to 2017. The conserved 98 clinical cryptococcal isolates included 97 C. neoformans and one C. gattii, and 90 (91.8%) isolates belonged to ST5 genotype VNI. Out of the 98 patients with cryptococcosis, 28 (28.6%) were HIV-infected and 32 (32.7%) had no underlying diseases. HIV-infected patients had higher mortality than HIV-uninfected patients (28.6% vs 14.3%, p=0.147). CONCLUSIONS: Most of the patients with cryptococcosis were not HIV-infected in this study, while patients with HIV had a higher mortality. Reduced susceptibility to fluconazole was observed among C. neoformans isolates, most of them belonged to ST5 genotype VNI having an impact on the effective dose of fluconazole.

Coronary CT Angiography Using Low Iodine Delivery Rate and Tube Voltage Determined by Body Mass Index: Superiority in Clinical Practice.

To explore the feasibility and superiority of iodine delivery rate (IDR) and tube voltage determined by patients' body mass index (BMI) in coronary CT angiography (CCTA), a total of 1567 patients undertaking CCTA during Feb. and Dec. 2016 were enrolled and divided into two groups. In the control group, the IDR and tube voltage were fixed, while in the experimental group, the IDR and tube voltage were determined by patients' BMI. The volume of iodinated contrast media (ICM), extravasation rate, extravasation volume, extravasation recovery interval, incidence rate of adverse reactions, effective dose (ED) and image quality of the two groups were compared. The experiments demonstrated that the ICM volume, extravasation rate, extravasation volume, extravasation recovery interval, incidence of adverse reactions and ED were lower or shorter in the experimental group than in the control group, and the differences were statistically significant (all P<0.05). However, there were no significant differences in the mean CT value, image noise, signal to noise ratio and contrast to noise ratio between the two groups (all P<0.05), which were consistent with the diagnosticians' subjective evaluation outcomes. Our findings suggested that in CCTA, it is feasible to determine the IDR and tube voltage based on patients' BMI; low tube voltage and IDR are superior to the fixed tube voltage and IDR and are worthy of clinical promotion.

Cryptococcal pleuritis with pleural effusion as the only clinical presentation in a patient with hepatic cirrhosis: A case report and literature review.

RATIONALE: Cryptococcosis is a significant life-threatening fungal infection in worldwide, mainly reported in immunocompromised patients. Pleural effusion presentation of cryptococcal infection as the only clinical presentation is rarely seen in pulmonary cryptococcosis, which may lead to be misdiagnosed, and the study on this subject will provide further insights. PATIENT CONCERNS: A 64-year-old man was hospitalized in our department and diagnosed as hepatic B cirrhosis. A computed tomography (CT) of the thorax showed a massive right pleural effusion without pulmonary parenchymal abnormalities. He was started on empirical treatment for pleural tuberculosis (TB). However, during his hospitalization, a right pleural effusion developed and fever was not controlled. DIAGNOSES: On day 14 admission, pleural fluid cultured positive for Cryptococcus neoformans. The C neoformans isolate belonged to ST5 and molecular type VNI (var. grubii). INTERVENTIONS: The patient was diagnosed with cryptococcal pleuritis, then amphotericin B and fluconazole were administrated. OUTCOMES: Finally, the patient was improved and discharged from our hospital. LESSONS: Similar cases in cryptococcal pleuritis patients with pleural effusion as the only clinical presentation in the literature are also reviewed. Through literature review, we recommend that pleural effusion cryptococcal antigen test should be used to diagnose cryptococcal pleuritis to reduce misdiagnosis. The early administration of antifungal drug with activity to Cryptococcus seemed beneficial in preventing dissemination of cryptococcosis.

Contrast dose reduction with shortened injection durations in coronary CT angiography on 16-cm Wide-detector CT scanner.

OBJECTIVES:: To investigate the use of shortened contrast injection with late triggering in coronary CT angiography (CCTA) for decreasing contrast dose and maintaining image quality. METHODS:: 106 patients for CCTA on a 16-cm wide-detector CT were prospectively enrolled into groups A (n = 50) and B (n = 56) randomly. Patient weight-dependent contrast medium (Iopamiro, 370 mgI ml-1) at dose rate of 25 mgI/kg/s was used with 8 s and the standard 10 s injection time in groups A and B, respectively. CT values of the aortic sinus (AS), right coronary artery, left anterior descending and left circumflex at the proximal, middle and distal segments were measured and compared. Subjective image quality was evaluated and analyzed with Fisher exact test. Contrast dose, injection rate and enhancement duration (between the start of enhancement in AS and scan finish) were also compared. RESULTS:: There was no difference in the injection rate and enhancement duration between the two groups (p > 0.05), while the total contrast dose in group A (36.2 ± 5.7 ml) was significantly lower than in group B (46.4 ± 6.3 ml) (p < 0.001). There was no difference for CT values in all major coronary vessels between the two groups and no difference in subjective image quality scores (all p > 0.05). CONCLUSION:: It is feasible to shorten contrast injection to 8 s in CCTA on wide-detector CT systems to significantly reduce contrast dosage, maintain adequate enhancement and reduce contrast-related artifacts. ADVANCES IN KNOWLEDGE:: (1) Coronary CT angiography (CCTA) scans with shortened contrast medium injection duration and late triggering are feasible with a 16-cm wide-detector CT system (2) Compared with the conventional CCTA with 10 s contrast injection duration, the new contrast injection protocol of using shortened injection duration (to 8 s) and late triggering reduces contrast dose to 36.2 ml, while maintaining adequate enhancement in vessels and reducing contrast-related artifacts.

Retraction: Into the eyes of bone marrow-derived mesenchymal stem cells therapy for myocardial infarction and other diseases.

[This retracts the article DOI: 10.21037/sci.2017.08.01.].

PCAF-mediated acetylation of Lin28B increases let-7 biogenesis in lung adenocarcinoma H1299 cells.

BACKGROUND: Lin28B and its paralog Lin28A are small RNA binding proteins that have similar inhibitory effects, although they target separate steps in the maturation of let-7 miRNAs in mammalian cells. Because Lin28B participates in the promotion and development of tumors mostly by blocking the let-7 tumor suppressor family members, we sought to explore the associated mechanisms to gain insights into how Lin28B might be decreased in human cancer cells to increase let-7 levels and reverse malignancy. RESULTS: We demonstrated that the histone acetyltransferase PCAF, via its cold shock domain, directly interacts with and subsequently acetylates Lin28B in lung adenocarcinoma-derived H1299 cells. RT-qPCR assays showed that both let-7a-1 and let-7g were increased in PCAF-transfected H1299 cells. Lin28B is acetylated by ectopic PCAF and translocates from the nucleus to the cytoplasm in H1299 cells. CONCLUSIONS: The effects of acetylated Lin28B on let-7a-1 and let-7g are similar to that of stable knockdown of Lin28B in H1299 cells. The new role of PCAF in mediating Lin28B acetylation and the specific release of its target microRNAs in H1299 cells may shed light on the potential application of let-7 in the clinical treatment of lung cancer patients.

Into the eyes of bone marrow-derived mesenchymal stem cells therapy for myocardial infarction and other diseases.

Applications of bone marrow-derived mesenchymal stem cells (BM-MSCs) have been documented for diseases occur in the sports system, the central nervous system, the cardiovascular system etc. However, poor viability of donor stem cells after transplantation limits their therapeutic efficiency. Although the autophagy theory has been reported, the underlying mechanisms are still poorly understood. Isolation and culture methods of mesenchymal stem cells are currently concentrate on four ways. Overall, BM-MSCs have both important research significance and clinical application value in cell replacement therapy, gene therapy and reconstruction of tissues as well as organs especially for myocardial infarction (MI). In this article, we review the biological characteristics of BM-MSCs and its research progress especially in MI.

Stress injuries and autophagy in mouse hippocampus after chronic cold exposure.

Cold exposure is an external stress factor that causes skin frostbite as well as a variety of diseases. Estrogen might participate in neuroprotection after cold exposure, but its precise mechanism remains unclear. In this study, mice were exposed to 10°C for 7 days and 0-4°C for 30 days to induce a model of chronic cold exposure. Results showed that oxidative stress-related c-fos and cyclooxygenase 2 expressions, MAP1LC3-labeled autophagic cells, Iba1-labeled activated microglia, and interleukin-1ß-positive pyramidal cells were increased in the hippocampal CA1 area. Chronic cold exposure markedly elevated the levels of estrogen in the blood and the estrogen receptor, G protein-coupled receptor 30. These results indicate that neuroimmunoreactivity is involved in chronic cold exposure-induced pathological alterations, including oxidative stress, neuronal autophagy, and neuroimmunoreactivity. Moreover, estrogen exerts a neuroprotective effect on cold exposure.

Successful treatment of an acute infective endocarditis secondary to fish bone penetrating into left atrium caused by Granulicatella adiacens and Candida albicans: A case report.

RATIONAL: Infective endocarditis caused by a foreign body of the upper digestive tract is rare. We report a rare case of Granulicatella adiacens and Candida albicans coinfection acute endocarditis combined with systematic embolization caused by a fish bone from the esophagus penetrating into the left atrium. PATIENT CONCERN: A 42-year-old woman was admitted to our hospital because of fever, abdominal pain, headache, and right limb weakness. DIAGNOSES: Clinical examination indicated endocarditis and systemic embolisms secondary to a fish bone from the esophagus penetrating into the left atrium. The emergency surgery confirmed the diagnosis. Cultures of blood and vegetation show G adiacens and C albicans. INTERVENTIONS: Antimicrobial therapy lasted 6 weeks after surgery. OUTCOMES: The patient was discharged with excellent condition7 weeks after hospitalization and was well when followed 6 months later. LESSONS: The successful treatment of this patient combines quick diagnosis, timely surgery, and effective antimicrobial regimen. This rare possibility should be kept up in mind in acute infective endocarditis cases.

A Fatal Strongyloides Stercoralis Hyperinfection Syndrome in a Patient With Chronic kidney Disease: A Case Report and Literature Review.

Strongyloides stercoralis hyperinfection syndrome is a rare but fatal disease, which occurs commonly in immunocompromised patients. Strongyloidiasis among patients with chronic kidney disease is rarely reported.A 55-year-old Chinese male presented to hospital with diarrhea and abdominal pain. He developed acute respiratory failure and progressed to diffuse alveolar hemorrhage owing to disseminated strongyloidiasis immediately. The bronchoalveolar lavage revealed filariform larvae of Strongyloides stercoralis.This patient was diagnosed with Strongyloides hyperinfection syndrome. Although albendazole, mechanical ventilator support, fluid resuscitation, vasopressor support, extracorporeal membrane oxygenation, hydrocortisone, and broadspectrum antimicrobials were actively used, the patient eventually died.Similar cases in patients with chronic kidney disease in the literature are also reviewed. Through literature review, we recommend that strongyloidiasis should be routinely investigated in patients with chronic kidney disease who will undergo immunosuppressive therapy.

Clinical and microbiological characteristics of Klebsiella pneumoniae liver abscess in East China.

BACKGROUND: Klebsiella pneumoniae has been the dominant pathogen for liver abscesses in several Asian countries. Although the prevalence of K. pneumoniae liver abscess (KLA) in mainland China is increasing recently, the clinical and microbiological characteristics of KLA in China have not been elucidated. METHODS: Clinical and microbiology characteristics of 45 consecutive patients with KLA from a tertiary teaching hospital in China between June 2008 and June 2012 were retrospectively evaluated. RESULTS: Vast majority of the strains were susceptible to main antimicrobial agents. Most of K. pneumoniae strains from pyogenic liver abscess patients belonged to K1/K2 serotype (68.9% for K1 serotype and 20% for K2 serotype). All K. pneumoniae strains were rmpA positive, and 68.9% of these strains were magA positive. Overall, 57.8% (26/45) of K. pneumoniae strains belonged to ST23. Twenty-five of 26 ST23 K. pneumoniae isolates (96.2%) from KLA patients were magA-positive and K1 serotype. Only 28.9% (13/45) of KLA isolates exhibited hypermucoviscous phenotype, which is clinically used as the characteristic of hypervirulent K. pneumoniae (hvKP). Liver abscess sizes in patients infected with hvKP were tend to be larger than those in patients infected with cKP. There was no significant association between the microbiological and clinical characteristics including serotypes, magA and rmpA genotypes, and STs with the metastatic infection and prognosis of KLA. CONCLUSIONS: Neither the serotypes, magA and rmpA genotypes, nor the STs of K. pneumoniae were associated with the metastatic infection and prognosis of KLA. However, further studies with larger sample are needed in the future.

Reversible acetylation of Lin28 mediated by PCAF and SIRT1.

Lin28 is a small RNA-binding protein that plays an important role in regulating developmental timing, stem cell reprogramming, and oncogenesis. However, the significance of the effect of post-translational modifications on Lin28 activity is not fully understood. In this study, we demonstrated that PCAF directly interacted with and acetylated Lin28. We also showed that the acetylation of Lin28 can be specifically reversed by the deacetylase SIRT1. These findings suggest that the PCAF/SIRT1 balance plays an important role in regulating Lin28 activity. Furthermore, we found that the cold shock domain of Lin28 is the major target of PCAF-mediated acetylation, which leads to a severe reduction in the Lin28 protein levels and an increase in the level of mature let-7a. This study provides the first demonstration that post-translational modification regulates Lin28 activity during let-7a biogenesis and sheds light on the regulation of Lin28 in ES cells and carcinogenesis.

Fosfomycin resistance among vancomycin-resistant enterococci owing to transfer of a plasmid harbouring the fosB gene.

The presence and characterisation of plasmid-mediated fosfomycin resistance determinants were investigated among 45 clinical vancomycin-resistant enterococci (VRE) isolated in Zhejiang Province, China. In total, 19 VRE were resistant to fosfomycin, of which 18 isolates had conjugative fosfomycin resistance and were positive for fosB. No reported fos genes were detected in the remaining isolate. Among the 18 fosB-carrying isolates, the fosB gene was always flanked by tnpA, suggesting the same novel fosB transposon. In 10 of the 18 fosB-carrying isolates, the fosB and tnpA genes were found reversely inserted in the vanA transposon Tn1546. In the remaining eight isolates the fosB and vanA genes were located on different plasmids. These findings indicate that acquisition of the conjugative plasmid harbouring the novel fosB transposon (ISL3-like transposon) and the Tn1546-like transposon (containing vanA and fosB) may explain, at least in part, the recent increase in fosfomycin-resistant Enterococcus faecium in China.