A scoping review of vasculitis as an immune-related adverse event from checkpoint inhibitor therapy of cancer: Unraveling the complexities at the intersection of immunology and vascular pathology

BACKGROUND/PURPOSE

Vasculitis as an immune-related adverse event (irAE) from checkpoint inhibitor therapy (ICI) to treat cancer is a rare clinical event, and little is known regarding its nosology, clinical manifestations, or response to treatment and outcomes.

METHODS

To address these gaps, we used the Preferred Reporting Items for Systemic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) framework to further define this complication. Two independent PUBMED searches in September and November of 2022 revealed 127 publications with 37 excluded from title by relevance, 43 excluded by article type, and 23 excluded due to lack of biopsy results, or biopsy negative for vasculitis. Twenty-nine documented cases from 24 publications were included for final analysis. Basic demographics, ICI details, timing of onset of vasculitis symptoms, irAE treatment and outcomes were collected. The vasculitides were classified using 2022 ACR/EULAR Vasculitis Classification Criteria as well as 2012 Revised Chapel-Hill Nomenclature. Adaptations from Naidoo et al. 2023 [1] consensus definitions for irAEs were used and efforts were made to classify steroid-responsive versus unresponsive irAEs.

RESULTS

Of the 29 cases reviewed, the average age of patients was 62.1 ± 11.0, composed of 58.6 % (n = 17) male and 41.3 % (n = 12) female. Prominent cancer types were lung cancer (41.4 %; n = 12), melanoma (41.4 %; n = 12), and renal cancer (10.3 %; n = 3), with majority being stage 4 (75.9 %, n = 22) and stage 3 (10.3 %, n = 3). Only 8 cases met the ACR/EULAR criteria, and by Chapel-Hill Nomenclature, approximately a third were small-vessel vasculitis (31.0 %; n = 9) with n = 4 positive for ANCA. Most biopsies were taken from the skin (37.9 %, n = 11) and kidney (24.1 %, n = 7). Patients were either treated with single (65.5 %, n = 19), dual (17.2 %; n = 5), or sequential (17.2 %; n = 5) ICI regimen which included anti-PD-1 therapy in all but one case, with mean of 8.7 ± 10.5 cycles received. Mean time to onset of symptoms from start of ICI was 7.2 ± 7.8 months, with 55.2 % occurring >3 months since the initial immunotherapy. Vasculitis treatment included glucocorticoids in 96 % of cases and immunotherapy was often discontinued (44.8 %; n = 13). Clinical improvement of irAE was documented in 86.2 % (n = 25). Data were missing in terms of fate of ICI (34.5 %; n = 10) and tumor outcomes (41.4 %; n = 12). Cancer progressed in 20.7 % (n = 6), stable in 34.5 % (n = 10) cases, and 6 patients died of all-causes.

CONCLUSION

Vasculitis as an irAE appears clinically heterogeneous and rare. Among reported cases with adequate documentation, vasculitis is of delayed onset following the initiation of immunotherapy. Outcomes of ICI-vasculitis were generally favorable, responding to glucocorticoids and immunotherapy withdrawal. There is an urgent need for more standardized reporting of rare irAEs such as vasculitis to clarify clinical risks, classification, relationship to immunotherapy and outcomes.

Age-related patterns in high-risk alcohol and cannabis use and their associations with positive and negative affect in young adulthood

OBJECTIVE

We examined age-varying associations between young adult simultaneous alcohol and marijuana/cannabis use (SAM) and heavy episodic drinking (HED) and positive and negative affect to inform harm reduction efforts.

METHODS

Young adults reporting past-year alcohol use (n = 556; ages 19-25) were recruited in a state where alcohol and nonmedical cannabis use was legal for those 21 +. Participants provided 24 repeated monthly assessments. Among those reporting past-month cannabis use on at least one survey, logistic time-varying effect models estimated (1) the age-varying prevalence of and associations between past-month SAM and HED and (2) age-varying unique associations of affect with SAM and HED.

RESULTS

There was a positive age-varying association between HED and SAM over time that was highest at age 19 (OR = 7.56), decreased until age 20.7 (OR = 3.39), increased until age 23.0 (OR = 4.85), and decreased until the association became non-significant by age 25. Negative affect was positively associated with SAM from ages 20.7 to 23.0, peaking at age 21.8 (OR = 1.36). Positive affect was positively associated with HED from ages 19.4 to 20.4 (peak OR = 1.25) and ages 22.5 to 24.5 (peak OR = 1.38). In contrast, positive affect was not uniquely associated with SAM nor negative affect with HED across ages 19-25.

CONCLUSIONS

While HED and SAM were positively associated throughout young adulthood and interventions could target them in tandem, their associations with affect suggest differential etiologic processes. Preventive intervention and harm reduction efforts should attend to psychological context in which these behaviors occur.

Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea

BACKGROUND

Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly.

AIM

To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea.

METHODS

A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs.

FINDINGS

In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024).

CONCLUSION

The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

Transposable Elements-Derived MicroRNA Expression Patterns in TCGA Dataset for 10 Species

MicroRNAs (miRNAs) are a class of non-coding RNAs that act as regulators of disease. An evolutionary approach to the disease could reveal factors such as diagnosis, treatment, and prognosis prediction. The expression patterns of transposable element (TEs)-derived miRNAs could help elucidate diseases, and their evolutionary patterns are also valuable. The 34 miRNAs were compared in terms of stage survival and tumor status in 33 carcinomas from TCGA. Expression levels were compared using a t-test and presented as differentially expressed miRNAs (DEMs). For DEMs showing statistically specific expression patterns for 3 conditions (normal and cancer, early and advanced stage, and survival), interactions with related genes in 10 species, including humans, were compared. The enrichment term was discovered for the gene-miRNA interactions. In 18 out of the 33 carcinomas, at least one miRNA was retrieved with P < .05 and |fold change| >.05. A total of 128 DEMs for the 9 miRNAs were identified. Based on the TargetScan database, interactions between miRNAs and genes in 10 species, including humans, were confirmed. The evolutionarily conserved miR-130a was observed in all 10 species, whereas miR-151a was only observed in humans. GO terms of related genes were selected for the miRNAs commonly found in each species. Evolutionary analysis of TE-derived disease-associated miRNAs was performed, and the evolutionarily conserved miR-130a-related carcinomas included renal and thyroid cancers. Human and rhesus monkey-specific miR-625 is associated with various carcinomas.

Regenerative capacity of trophoblast stem cell-derived extracellular vesicles on mesenchymal stem cells

BACKGROUND

Human mesenchymal stem cells (MSCs) are therapeutic for clinical applications because of their excellent immunomodulatory and multiple lineage differentiation abilities at tissue injury sites. However, insufficient number of cells and lack of regenerative properties during in vitro expansion still limit the clinical applicability of MSC therapies. Here, we demonstrated a preconditioning strategy with trophoblast stem cell-derived extracellular vesicles (TSC-EVs) to boost the proliferation and regenerative capacity of MSCs.

METHODS

We employed cell proliferation analyses such as CCK8 and BrdU assays to determine the proliferation-promoting role of TSC-EVs on MSCs. Osteogenic effects of TSC-EVs on MSCs were assessed by alkaline phosphatase (ALP) activity, calcium assays, and calvarial bone defect animal models. For skin regenerative effects, skin wound mice model was exploited to analyze wound-healing rate in this study, as well as immunofluorescence and histological staining evaluates. We also performed the small RNA profiling and RNA-sequencing analyzes to understand the cellular mechanism of TSC-EVs on MSCs.

RESULTS

TSC-EVs significantly promoted MSC proliferation under xeno-free conditions and facilitated the therapeutic effects of MSCs, including osteogenesis, anti-senescence, and wound healing. Transcriptomic analysis also provided evidence that specific microRNAs in TSC-EVs and differentially expressed genes (DEGs) in TSC-EV-treated MSCs showed the possibility of TSC-EVs triggering the regenerative abilities of MSCs with cytokine interaction. Hence, we found that NGF/Akt signaling mediated the regenerative effects of TSC-EVs on MSCs as a particular cellular signaling pathway.

CONCLUSION

The results of this study demonstrated the functional properties of TSC-EVs on MSCs for MSC-based therapeutic applications, suggesting that TSC-EVs may serve as a potential preconditioning source for MSC therapy in the clinical field of regenerative medicine.

Impact of discontinuing isolation in a private room for patients infected or colonized with vancomycin-resistant enterococci (VRE) on the incidence of healthcare-associated VRE bacteraemia in a hospital with a predominantly shared-room setting

BACKGROUND

Isolating patients infected or colonized with vancomycin-resistant enterococci (VRE) in a private room or cohort room to prevent hospital transmission is controversial.

AIM

To evaluate the effect of a relaxed isolation policy for VRE-infected or colonized patients on healthcare-associated (HA) VRE bacteraemia in an acute care hospital with a predominantly shared-room setting.

METHODS

The incidence of HA VRE bacteraemia was compared during a private isolation era (October 2014-September 2017), a cohort isolation era (October 2017-June 2020), and a no isolation era (July 2020-June 2022). Using Poisson regression modelling, an interrupted time-series analysis was conducted to analyse level changes and trends in incidences of HA VRE bacteraemia for each era.

FINDINGS

The proportion of VRE-infected or -colonized patients staying in shared rooms increased from 18.3% in the private isolation era to 82.6% in the no isolation era (P < 0.001). There was no significant difference in the incidences of HA VRE bacteraemia between the private isolation era and the cohort isolation era (relative risk: 1.01; 95% confidence interval: 0.52-1.98; P = 0.977) or between the cohort isolation era and the no isolation era (0.99; 0.77-1.26; P = 0.903). In addition, there was no significant slope increase in the incidence of HA VRE bacteraemia between any of the eras.

CONCLUSION

In a hospital with predominantly shared rooms, the relaxation of isolation policy did not result in increased HA VRE bacteraemia, when other infection control measures were maintained.

Osteogenic Efficacy of Human Trophoblasts-Derived Conditioned Medium on Mesenchymal Stem Cells

Trophoblasts play an important role in the regulation of the development and function of the placenta. Our recent study demonstrated the skin regeneration capacity of trophoblast-derived extracellular vesicles (EV). Here, we aimed to determine the potential of trophoblast-derived conditioned medium (TB-CM) in enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (MSCs). We found that TB-CM promoted the osteogenic differentiation of MSCs in a dose-dependent manner. Furthermore, it inhibited adipogenesis of MSCs. We also found that the primary trophoblast-derived conditioned medium (PTB-CM) significantly enhanced the proliferation and osteogenic differentiation of human MSCs. Our study demonstrated the regulatory mechanisms underlying the TB-CM-induced osteogenesis in MSCs. An upregulation of genes associated with cytokines/chemokines was observed. The treatment of MSCs with TB-CM stimulated osteogenesis by activating several biological processes, such as mitogen-activated protein kinase (MAPK) and bone morphogenetic protein 2 (BMP2) signaling. This study demonstrated the proliferative and osteogenic efficacies of the trophoblast-derived secretomes, suggesting their potential for use in clinical interventions for bone regeneration and treatment.

Different Transcutaneous Auricular Vagus Nerve Stimulation Parameters Modulate the Anti-Inflammatory Effects on Lipopolysaccharide-Induced Acute Inflammation in Mice

Vagus nerve stimulation (VNS) is considered a potential method for anti-inflammation due to the involvement of the VN in the cholinergic anti-inflammatory pathway (CAP) formation of a connection between the central nervous system and peripheral immune cells that help relieve inflammation. However, whether a non-invasive transcutaneous auricular VNS (taVNS) modulates the inflammation levels via altering the parameter of taVNS is poorly understood. This study aimed to determine the differential inhibitory effects of taVNS on lipopolysaccharide (LPS)-induced systemic inflammation using electrical stimulation parameters such as pulse frequency and time. The taVNS-promoted CAP activity significantly recovered LPS-induced tissue injuries (lung, spleen, and intestine) and decreased inflammatory cytokine levels and tissue-infiltrated immune cells. Interestingly, the anti-inflammatory capacity of taVNS with 15 Hz was much higher than that of taVNS with 25 Hz. When a cytokine array was used to investigate the changes of inflammation and immune response-related cytokines/chemokines expression in taVNS with 15 Hz or 25 Hz treatment in LPS-induced endotoxemia in mice, most of the expression of cytokines/chemokines associated with pro-inflammation was severely decreased in taVNS with 15 Hz compared to 25 Hz. This study demonstrated that the taVNS parameter could differentially modulate the inflammation levels of animals, suggesting the importance of taVNS parameter selection for use in feasible interventions for acute inflammation treatment.

Indole-3-carbinol inhibits the proliferation of colorectal carcinoma LoVo cells through activation of the apoptotic signaling pathway

Indole-3-carbinol (I3C) is a phytochemical that exhibits growth-inhibitory activity against various cancer cells. However, there are limited studies on the effects of I3C on colon cancer cells. In this study, the growth-inhibitory activity of I3C against the human colorectal carcinoma cell line (LoVo) was examined. The results of the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide, colony formation, and cell counting assays revealed that I3C suppressed the proliferation of LoVo cells. Microscopy and wound-healing analyses revealed that I3C affected the morphology and inhibited the migration of LoVo cells, respectively. I3C induced apoptosis and DNA fragmentation as evidenced by the results of fluorescein isothiocyanate-conjugated annexin V staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling assay, respectively. Additionally, I3C arrested the cell cycle at the G0/G1 phase and enhanced the reactive oxygen species levels. Western blotting analysis revealed that treatment with I3C resulted in the activation of apoptotic proteins, such as poly(ADP-ribose) polymerase, caspase-3, caspase-7, caspase-9, Bax, Bim, and p53 in LoVo cells. These results indicate that I3C induces apoptosis in LoVo cells by upregulating p53, leading to the activation of Bax and caspases. Taken together, I3C exerts cytotoxic effects on LoVo cells by activating apoptosis.

Induction of cell cycle arrest and apoptosis by tomentosin in hepatocellular carcinoma HepG2 and Huh7 cells

Tomentosin, a sesquiterpene lactone, is known to possess various biological activities. However, its anticarcinogenic activity against human hepatocellular carcinoma (HCC) cells has not been investigated in detail. Thus, this study aimed to elucidate the cytotoxic mechanism of tomentosin in human HCC cell lines HepG2 and Huh7. WST-1, cell counting, and colony formation assay results showed that treatment with tomentosin decreased the viability and suppressed the proliferation rate of HepG2 and Huh7 cells in a dose- and time-dependent manner. Cell cycle analysis revealed increased population of cells at the SubG1 and G2/M stage, and decreased population of cells at the G0/1 stage in HepG2 and Huh7 cells treated with tomentosin. Annexin V/propidium iodide double staining and TUNEL assay results showed increased apoptotic cell population and DNA fragmentation in HepG2 and Huh7 cells treated with tomentosin. Western blotting analysis results showed that tomentosin treatment significantly increased the expression level of Bax, Bim (short form), cleaved PARP1, FOXO3, p53, pSer15p53, pSer20p53, pSer46p53, p21, and p27, but decreased the expression of Bcl2, caspase3, caspase7, caspase9, cyclin-dependent kinase 2 (CDK2), CDK4, CDK6, cyclinB1, cyclinD1, cyclinD2, cyclinD3, and cyclinE in a dose-dependent manner. Taken together, this study revealed that tomentosin, which acted through cell cycle arrest and apoptosis, may be a useful therapeutic option against HCC.

Stacking Fault Energy Analyses of Additively Manufactured Stainless Steel 316L and CrCoNi Medium Entropy Alloy Using In Situ Neutron Diffraction

Stacking fault energies (SFE) were determined in additively manufactured (AM) stainless steel (SS 316 L) and equiatomic CrCoNi medium-entropy alloys. AM specimens were fabricated via directed energy deposition and tensile loaded at room temperature. In situ neutron diffraction was performed to obtain a number of faulting-embedded diffraction peaks simultaneously from a set of (hkl) grains during deformation. The peak profiles diffracted from imperfect crystal structures were analyzed to correlate stacking fault probabilities and mean-square lattice strains to the SFE. The result shows that averaged SFEs are 32.8 mJ/m2 for the AM SS 316 L and 15.1 mJ/m2 for the AM CrCoNi alloys. Meanwhile, during deformation, the SFE varies from 46 to 21 mJ/m2 (AM SS 316 L) and 24 to 11 mJ/m2 (AM CrCoNi) from initial to stabilized stages, respectively. The transient SFEs are attributed to the deformation activity changes from dislocation slip to twinning as straining. The twinning deformation substructure and atomic stacking faults were confirmed by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The significant variance of the SFE suggests the critical twinning stress as 830 ± 25 MPa for the AM SS 316 L and 790 ± 40 MPa for AM CrCoNi, respectively.

Skin-integrated wireless haptic interfaces for virtual and augmented reality

Traditional technologies for virtual reality (VR) and augmented reality (AR) create human experiences through visual and auditory stimuli that replicate sensations associated with the physical world. The most widespread VR and AR systems use head-mounted displays, accelerometers and loudspeakers as the basis for three-dimensional, computer-generated environments that can exist in isolation or as overlays on actual scenery. In comparison to the eyes and the ears, the skin is a relatively underexplored sensory interface for VR and AR technology that could, nevertheless, greatly enhance experiences at a qualitative level, with direct relevance in areas such as communications, entertainment and medicine^1,2. Here we present a wireless, battery-free platform of electronic systems and haptic (that is, touch-based) interfaces capable of softly laminating onto the curved surfaces of the skin to communicate information via spatio-temporally programmable patterns of localized mechanical vibrations. We describe the materials, device structures, power delivery strategies and communication schemes that serve as the foundations for such platforms. The resulting technology creates many opportunities for use where the skin provides an electronically programmable communication and sensory input channel to the body, as demonstrated through applications in social media and personal engagement, prosthetic control and feedback, and gaming and entertainment.

The impact of perceived stress on skin ageing

Skin ageing can be divided according to phenotypical features into intrinsic (by the passage of time) and extrinsic (with the addition of the effects of environmental factors). Photoageing is by far the most researched factor of extrinsic ageing but the additional impact of other factors such as cigarette smoking and exposure to air pollution ought to be taken into account. One of the least researched topics in relation to extrinsic skin ageing is the impact of psychological stress. A contemporary review of response of human skin to stress describes the molecular mechanisms of extrinsic skin ageing, but has fallen short of explaining resilience to stress exhibited by people. Mechanisms to regulate gene expression, define cellular identity and promote functionality are responsible for the adaptive response to stressful events. Conversely, maladaptive response of human tissues to chronic stress appears to have an impact on gene regulation. Epigenetics is the study of heritable changes in organisms due to modifications in gene activity and expression, as opposed to the genetic code (DNA genome). Chronic stress appears to be an important factor in determining an individual's vulnerability to ageing and age-related comorbidities via epigenetic modifications. Forerunners in epigenetic research recognized the necessity of a reliable biomarker in order to develop a better understanding of the role of epigenomics in ageing. Genomic DNA methylation patterns (DNAm) appear to be valuable in age prediction but variability in specificity exists across species of mammals, human races and tissues. Neuroscience research appears to be leading the way in epigenomics whilst the lack of a valid and reliable DNAm-associated age predictor compatible with human skin tissue hinders research endeavours for the epigenetics of skin ageing.

Isolation and molecular identification for autochthonous starter Saccharomyces cerevisiae with low biogenic amine synthesis for black raspberry (Rubus coreanus Miquel) wine fermentation

Biogenic amines (BAs) are widely present in nearly all fermented foods and beverages, and excess consumption can cause adverse health effects. To prepare BA-free Korean black raspberry wine (BRW), four autochthonous starter yeast strains without hazardous BA synthesis activity were selected and their physiological and biochemical properties were examined. The selected strains were identified as Saccharomyces cerevisiae based on 26S rDNA sequencing and microsatellite analysis. Molecular fingerprinting revealed that isolates were quite different from commercial wine yeast S. cerevisiae (52.4% similarity), but genetically relevant to commercial beer yeasts. The four S. cerevisiae strains produced over 10% ethanol during BRW fermentation. In addition, the fermented BRW with these strains showed higher levels of total flavonoids and similar antioxidant activity compared to the control sample. Potentially hazardous BAs that commonly occur in black raspberry extract (BRE) such as cadaverine, histamine, and spermidine were also not detected in the fermented BRW. Thus, we suggest that our strains are promising fermentation tools to ensure high quality and enhanced functionality in the production of BA-free BRW.

Cytoprotective effects of taxifolin against cadmium-induced apoptosis in human keratinocytes

Cadmium (Cd) is a heavy metal widely used in industry, and the skin is an important target of this metal. Taxifolin (Tax), a natural source of bioflavonoids found in various conifers, exerts multiple biologic effects on skin cells. However, the mechanisms by which Tax protects keratinocytes against Cd are currently unclear. We investigated the cytoprotective effects of Tax against Cd-induced apoptosis in the human HaCaT keratinocyte. The water-soluble tetrazolium salt (WST-1) assay and Annexin V/propidium iodide double-staining assay results showed that Cd-induced cell death was lower in cells treated with Tax (0–100 μM) than in cells treated with Cd alone. Additionally, a reduction of Cd-induced DNA fragmentation by Tax was shown by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling assay. The levels of reactive oxygen species were also lower in Cd/Tax-treated cells than in Cd-treated cells. We employed a two-dimensional electrophoresis-based proteomic analysis to identify treatment-related alterations in protein expression. Tax downregulated cathepsin B and D and upregulated hsp27, cyclophilin A, and peroxiredowin-1. Western blotting confirmed the downregulation of cathepsin B and D and the upregulation of hsp27. The cytoprotective effects of Tax against Cd-induced apoptosis were also characterized by the changes in the activity of caspase 3, -7, poly ADP-ribose polymerase, the cellular proliferation-related ERK1/2, and AKT. Furthermore, the levels of cell cycle-related proteins, such as SP1 and p21, decreased, whereas p53 level increased. We concluded that Tax reduced Cd cytotoxicity and Cd-induced apoptosis by inhibiting the apoptotic pathway.

Anticarcinogenic effect of indole-3-carbinol (I3C) on human hepatocellular carcinoma SNU449 cells

Many cruciferous vegetables, including cabbage, contain indole-3-carbinol (I3C), which is a known anticarcinogen. However, the anticarcinogenic effects of I3C on liver cancer have not been investigated. Therefore, this study was conducted to evaluate the anticarcinogenic effects of I3C in human hepatocellular carcinoma (HCC) SNU449 cells. The results of MTT and WST-1 assays indicated that treatment of SNU449 cells with I3C decreased viability in dose- and time-dependent manners, while colony formation assays indicated that I3C also inhibited proliferation of SNU449 cells. Moreover, fluorescence-activated cell sorter analysis showed that I3C induced apoptosis in SNU449 cells in dose- and time-dependent manners. Furthermore, terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling revealed that I3C induced DNA fragmentation in SNU449 cells in a time-dependent manner, while Western blotting showed that apoptotic proteins such as p53, cleaved PARP, caspase-3, and caspase-7 were activated in SNU449 cells following treatment with I3C. Finally, reactive oxygen species-related protein peroxiredoxin-1 and thioredoxin-1 expression decreased in I3C-treated SNU449 cells. The aim of our study is to investigate the unknown mechanisms responsible for the apoptotic effects of I3C on human HCC SNU449 cells, and the results suggest that I3C may be useful for the prevention and treatment of liver cancer.

Frequency and risk factors of drug-induced liver injury during treatment of multidrug-resistant tuberculosis

OBJECTIVES

To investigate the risk factors for drug-induced liver injury (DILI) during the treatment of multidrug-resistant tuberculosis (MDR-TB) and to compare the frequency of DILI in patients with and those without chronic liver disease (CLD).

SETTING

This was a retrospective observational cohort study including 299 consecutive patients who started MDR-TB treatment from January 2009 to December 2013.

DESIGN

Of the 299 patients, 35 had alcoholic liver disease (ALD group), 16 had hepatitis B virus infection (HBV group) and 11 had hepatitis C virus infection (HCV group). The remaining 237 patients without CLD were selected as the control group.

RESULTS

DILI occurred in 29 (9.7%) patients. The frequency of DILI was significantly higher in the ALD (17.1%, P = 0.038), HBV (31.3%, P = 0.005) and HCV groups (27.3%, P = 0.037) than in the control group (6.3%). Among all patients taken together, having HBV and HCV infection were independent risk factors for the occurrence of DILI during MDR-TB treatment.

CONCLUSION

DILI during MDR-TB treatment occurred more frequently in patients with CLD due to ALD, HBV and HCV infection than in those without CLD.

Heat-shock protein-90 prolongs septic neutrophil survival by protecting c-Src kinase and caspase-8 from proteasomal degradation

The brief lifespan of the polymorphonuclear neutrophil (PMN) is regulated through its capacity to undergo apoptosis, a constitutive process that is actively inhibited during sepsis. We sought to define the cellular mechanisms through which Heat Shock Protein 90 (Hsp90) prolongs the survival of inflammatory PMN. We evaluated Hsp90 expression and interaction with client proteins in PMNs from patients with sepsis and in healthy control PMNs treated with LPS (1 μg/mL). Hsp90 activity was inhibited pharmacologically using radicicol (Rad; 1 μM), and Hsp90 transcription was silenced in septic PMN using siRNA. PMN apoptosis was evaluated by flow cytometry and expression of cleaved caspase-8 and -3. Septic PMNs showed reduced rates of apoptosis compared with control PMNs 21 h after isolation, and Hsp90-α mRNA was significantly more abundant in septic PMN. Caspase-8 coimmunoprecipitated with Hsp90, c-Src, and the p85 inhibitory subunit of PI3K in both septic and LPS-treated PMN. Inhibition of Hsp90 activity with Rad or its translation using siRNA restored basal rates of apoptosis in both septic and LPS-treated PMN. Radicicol further reduced c-Src protein abundance, increased the ubiquitination of caspase-8 and c-Src, and enhanced the cleavage of caspase-8 and -3. We conclude that Hsp90 prolongs the survival of activated neutrophils by stabilizing a molecular complex of c-Src kinase and caspase-8, preventing their ubiquitination, and resulting in inhibition of the catalytic activity of caspase-8 and -3.

Association between Systolic Blood Pressure after Thrombolysis and Early Neurological Improvement in Ischaemic Stroke Patients

Introduction

This study aimed to evaluate the relationship between systolic blood pressures (SBPs) within 12 hours after intravenous recombinant tissue plasminogen activator (rtPA) treatment and early neurological outcomes.

Methods

This was a retrospective observational study of acute ischaemic stroke (AIS) patients who received intravenous rtPA administration. SBPs at the time of rtPA bolus and thereafter every hour were collected. The mean, standard deviation, and coefficient of variation values of SBP during the periods of 0-2 h, 2-6 h, and 6-12 h were calculated. The primary outcome was major neurologic improvement (MNI) at 24 hours after thrombolysis.

Results

Serial measures of SBPs revealed different 12-hour courses between the patients with and without MNI. The difference of SBP tendency was statistically significant (p=0.013). In univariate analysis, patients with MNI showed lower levels of mean SBPs during the periods of 2-6 h and 6-12 h (p=0.030 and p=0.005, respectively), and higher frequency of very early neurologic improvement (VENI) at the end of rtPA infusion (p<0.001). In logistic regression analysis, VENI at 1 h, mean SBP value during 6-12 h, and atrial fibrillation were independently related to MNI at 24 h.

Conclusions

SBP level during the first 12 hours after intravenous rtPA treatment may be an important clinical factor that is associated with early neurological improvement of AIS patients.

Phase I/II clinical trial to assess safety and efficacy of intratumoral and subcutaneous injection of HVJ-E in castration-resistant prostate cancer patients

Inactivated Sendai virus particles (hemagglutinating virus of Japan envelope (HVJ-E)) have a novel antitumor effect: HVJ-E fused to prostate cancer cells via cell surface receptor causes apoptosis of prostate cancer cells in vitro and in vivo. HVJ-E also induces antitumor immunity by activating natural killer (NK) cells and cytotoxic T cells and suppressing regulatory T cells in vivo. We conducted an open-label, single-arm, phase I/II clinical trial in patients with castration-resistant prostate cancer (CRPC) to determine the safety and efficacy of intratumoral and subcutaneous injection of HVJ-E. Patients with CRPC who were docetaxel-resistant or could not receive docetaxel treatment were eligible. HVJ-E was injected directly into the prostate on day 1 and subcutaneously on days 5, 8 and 12 in two 28-day treatment cycles using a 3+3 dose-escalation design. The primary end points were to evaluate safety and tolerability of HVJ-E. The secondary end points were to analyze tumor immunity and antitumor effect. The study is registered at UMIN Clinical Trials Registry, number UMIN000006142. Seven patients were enrolled, and six patients received HVJ-E. Grade 2 or 3 adverse events (Common Terminology Criteria for Adverse Events Ver. 4.0) were urinary retention and lymphopenia from which the patients recovered spontaneously. No Grade 4 adverse events were observed. Radiographically, three patients had stable disease in the low-dose group, and one patient had stable disease and two had progressive disease in the high-dose group. The prostate-specific antigen (PSA) declined from 14 to 1.9 ng ml^-1 in one patient in the low-dose group after two cycles of HVJ-E treatment, and the PSA response rate was 16.6%. NK cell activity was elevated from day 12 to day 28 after HVJ-E administration, whereas serum interleukin-6, interferon (IFN)-α, IFN-β and IFN-γ levels were not affected by HVJ-E treatment. Intratumoral and subcutaneous injections of HVJ-E are feasible and PSA response was observed in a subgroup of CRPC patients.

Epithelium-specific Ets transcription factor-1 acts as a negative regulator of cyclooxygenase-2 in human rheumatoid arthritis synovial fibroblasts

Background

Rheumatoid arthritis (RA) is characterized by excessive synovial inflammation. Cyclooxygenase-2 (COX-2) is an enzyme that catalyzes the conversion of arachidonic acid (AA) into prostaglandins. Epithelium-specific Ets transcription factor-1 (ESE-1) was previously demonstrated to upregulate COX-2 in co-operation with nuclear factor kappa B (NFκB) in macrophages and chondrocytes. However, the role of ESE-1 in RA pathology has remained unclear. In this study, we aimed to elucidate the relationship between ESE-1 and COX-2 in RA synovial fibroblasts (RASFs) using a HD-Ad-mediated knockdown approach.

Results

ESE-1 and COX-2 were induced by IL-1β in RASFs that corresponded with an increase in PGE₂. Endogenous levels of ESE-1 and COX-2 in human RASFs were analyzed by RT-qPCR and Western blot, and PGE₂ was quantified using competitive ELISA. Interestingly, knockdown of ESE-1 using helper-dependent adenovirus (HD-Ad) led to a significant upregulation of COX-2 at a later phase of IL-1β stimulation. Examination of ESE-1 intracellular localization by nuclear fractionation revealed that ESE-1 was localized in the nucleus, occupying disparate cellular compartments to NFκB when COX-2 was increased. To confirm the ESE-1-COX-2 relationship in other cellular systems, COX-2 was also measured in SW982 synovial sarcoma cell line and ESE-1 knockout (KO) murine macrophages. Similarly, knockdown of ESE-1 transcriptionally upregulated COX-2 in SW982 and ESE-1 KO murine macrophages, suggesting that ESE-1 may be involved in the resolution of inflammation.

Conclusion

ESE-1 acts as a negative regulator of COX-2 in human RASFs and its effect on COX-2 is NFκB-independent.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-016-0105-7) contains supplementary material, which is available to authorized users.

Influence of Multi-Gene Allele Combinations on Grain Size of Rice and Development of a Regression Equation Model to Predict Grain Parameters

BACKGROUND

Grain size is one of the key factors determining yield and quality in rice. A large number of genes are involved in the regulation of grain size parameters such as grain length and grain width. Different alleles of these genes have different impacts on the grain size traits under their control. However, the combined influence of multiple alleles of different genes on grain size remains to be investigated. Six key genes known to influence grain size were investigated in this study: GS3, GS5, GS6, GW2, qSW5/GW5, and GW8/OsSPL16. Allele and grain measurement data were used to develop a regression equation model that can be used for molecular breeding of rice with desired grain characteristics.

RESULTS

A total of 215 diverse rice germplasms, which originated from or were developed in 28 rice-consuming countries, were used in this study. Genotyping analysis demonstrated that a relatively small number of allele combinations were preserved in the diverse population and that these allele combinations were significantly associated with differences in grain size. Furthermore, in several cases, variation at a single gene was sufficient to influence grain size, even when the alleles of other genes remained constant. The data were used to develop a regression equation model for prediction of rice grain size, and this was tested using data from a further 34 germplasms. The model was significantly correlated with three of the four grain size-related traits examined in this study.

CONCLUSION

Rice grain size is strongly influenced by specific combinations of alleles from six different genes. A regression equation model developed from allele and grain measurement data can be used in rice breeding programs for the development of new rice varieties with desired grain size and shape.

The uncovering of ESE-1 in human neutrophils: implication of its role in neutrophil function and survival

Epithelium-specific Ets transcription factor 1 (ESE-1) is a member of the E26 transformation-specific family of transcription factors that has an epithelial-restricted constitutive expression but is induced by inflammatory stimuli in non-epithelial cells. Here we report that ESE-1 is constitutively expressed in human, but not in murine, neutrophils and that ESE-1 is modestly upregulated in septic patient neutrophils. In normal human neutrophils, ESE-1 was detected at both RNA and protein levels but was found to be an unstable nuclear protein ex vivo. ESE-1 transcription was also induced during all-trans retinoic acid-mediated HL-60 differentiation, a human promyelocytic cell line often used as an in vitro model of human neutrophils. Elf3-/- mice had normal neutrophils but a reduced number of circulating B-lymphocytes. These findings indicate a potential role of ESE-1 in regulating human neutrophil differentiation and function, and that it has different roles in the immune system of different species.

Monotherapy with tacrolimus for heart and liver transplant: a case report

BACKGROUND

Multiple-organ transplantation cases are rare, partly due to the shortage of donor organs. However, recent reports of outcomes of multiple-organ transplantations show encouraging survival rates for recipients as compared to single-organ transplant recipients.

CASE REPORT

A 33-year-old female who was a known hepatitis B carrier and who had been diagnosed with peripartum dilated cardiomyopathy was experiencing end-stage heart failure. The patient received orthotopic heart transplantation. After heart transplantation, the recipient received prednisolone, cyclosporine, and mycophenolate mofetil for immunosuppressive therapy. Seventy-one days later, the recipient began to develop progressive jaundice, ascites, and hepatoencephalopathy and was re-admitted to the hospital. Fulminant hepatitis was diagnosed. She was referred for emergency cadaveric liver transplantation 110 days after the heart transplantation because of her critical condition. After transplantation, she was improved and her condition maintained by a single immunosuppressive therapy, tacrolimus, with mean dose of 0.06 mg/kg/d.

CONCLUSION

We presented a case that was complicated by fulminant hepatitis after heart transplantation and successfully rescued by liver transplantation.

Unusual congenital pulmonary anomaly with presumed left lung hypoplasia in a young dog

A seven-month-old, entire, male miniature schnauzer dog was referred with acute vomiting, inappetence and depression primarily as a result of a gastric foreign body (pine cones). During investigations, thoracic radiographs revealed increased volume of the right lung lobes, deviated cardiomediastinal structures and elevation of the heart from the sternum. Thoracic computed tomography revealed left cranial lung lobe hypoplasia and extension of the right cranial lung parenchyma across the midline to the left hemithorax. Branches of the right pulmonary vessels and bronchi also crossed the midline and extended to the left caudal lung lobe. These findings suggested that the right and left lungs were fused. In humans this finding is consistent with horseshoe lung, which is an uncommon congenital malformation. To the authors' knowledge, this case represents the first report of such a pulmonary anomaly in a dog.

Coupling of air/metal and substrate/metal surface plasmon polaritons in Au slit arrays fabricated on quartz substrate

We report on the coupling of the air/metal mode and the substrate/metal mode surface plasmon polaritons in one-dimensional metallic slit arrays fabricated on a dielectric substrate. Anti-crossing is exhibited at an incident angle where the two independent modes can be resonantly excited at a specific wavelength. The size of the anti-crossing gap was measured while changing the metal thickness.

Secondhand smoke exposure and osteoporosis in never-smoking postmenopausal women: the Fourth Korea National Health and Nutrition Examination Survey

SUMMARY

The association between secondhand smoke (SHS) exposure and lumbar and femoral neck osteoporosis was assessed in postmenopausal never-smoking Korean women. The presence of family members who actively smoked was associated with femoral neck osteoporosis. The number of cigarettes consumed by cohabitant smokers was positively associated with lumbar and femoral neck osteoporosis.

INTRODUCTION

This study aimed to assess the association between SHS and postmenopausal osteoporosis.

METHODS

Of 2,067 postmenopausal women (age, ≥55 years) participating in the Fourth Korea National Health and Nutrition Examination Survey, 925 never-smokers identified through interviews and urinary cotinine level verification were enrolled. Cross-sectional relationships between self-reported SHS exposure and osteoporosis of the lumbar vertebrae and femoral neck (defined using the World Health Organization T-score criteria) were investigated by bone densitometry.

RESULTS

Participants having actively smoking family members showed increased adjusted odds ratio (aOR) for femoral neck osteoporosis compared with participants not exposed to SHS (aOR, 3.68; 95 % confidence interval [CI], 1.23-10.92). Participants whose cohabitant smokers consumed any number of cigarettes per day showed increased occurrences for lumbar and femoral neck osteoporosis compared with the nonexposed group. Participants whose cohabitant smokers consumed ≥20 cigarettes/day showed increased aORs for lumbar (aOR, 5.40; 95 % CI, 1.04-28.04) and femoral neck (aOR, 4.35; 95 % CI, 1.07-17.68) osteoporosis compared with participants not exposed to SHS.

CONCLUSIONS

In postmenopausal never-smoking Korean women, exposure to SHS was positively associated with osteoporosis. This finding further emphasizes a need to identify vulnerable groups exposed to SHS to increase bone health.

Magnetic resonance venography evaluating veins flow for legs by application of long stretch elastic bandage

AIM

Varicose veins are a common feature of chronic venous disease that causes pain and swelling of legs. Long stretch elastic bandages are one of the methods used to prevent and treat venous disease, but diagnostic benefit by magnetic resonance imaging (MRI) is not widely promoted. This study aims to evaluate the effects of long stretch elastic bandages using a non-contrast magnetic resonance venographic (MRV) technique by detecting influence on circumferences and flow velocities of varicose and deep veins, before and immediately after application of long stretch elastic bandages.

METHODS

Twelve patients presenting with visible varicose veins underwent MRV. The level of the superficial varicose and deep veins before and after wearing long stretch elastic bandages was recorded.

RESULTS

By comparing before and after long stretch elastic bandages, all 12 cases showed statistical significant decrease of the superficial venous flow areas; 9 out of 12 cases showed statistical significant change of the superficial (decreased) and deep (increased) venous flow rates. However, due to technical limitation, over half of the cases could not record the change of the deep venous flow areas.

CONCLUSION

The non-contrast MRV technique with Cine phase contrast, is capable to detect the short term beneficial effects of long stretch elastic bandages by measuring change of the superficial venous flow areas and superficial and deep venous flow rates.

Aspirin use and risk for lung cancer: a meta-analysis

BACKGROUND

Aspirin has received increasing attention owing to its potential as a chemopreventive agent against lung cancer. Previous observational studies have reported inconsistent findings on this issue. We investigated the association between aspirin use and risk for lung cancer by conducting a meta-analysis.

PATIENTS AND METHODS

Relevant studies were identified by searching Medline, EMBASE, and Cochrane Library to December 2009. We also reviewed relevant bibliographies from the retrieved articles. Two authors independently extracted data and assessed study quality. Disagreements were resolved by consensus.

RESULTS

Fifteen studies (six case-control studies and nine prospective cohort studies) were included in the final meta-analysis. When all studies were pooled, the odds ratio (OR) of aspirin use for lung cancer risk was 0.86 [95% confidence interval (CI) 0.76-0.98]. In subgroup meta-analyses, there was no association between aspirin use and lung cancer risk among cohort studies (relative risk, 0.97; 95% CI 0.87-1.08), while there was a significant association among case-control studies (OR, 0.74; 95% CI 0.57-0.99). In a subgroup meta-analysis by quality of study methodology, a significant protective effect of aspirin use on lung cancer was observed only among eight low-quality studies (OR, 0.82; 95% CI 0.68-0.99), but not among seven high-quality studies (OR, 0.90; 95% CI 0.76-1.07).

CONCLUSIONS

Overall, the findings of this meta-analysis support that there was no association between aspirin use and lung cancer risk. Our findings should be confirmed in future prospective cohort studies or randomized, controlled trials.

Acute appendicitis: relationships between CT-determined severities and serum white blood cell counts and C-reactive protein levels

OBJECTIVES

The aim of this study was to evaluate the relationships between the severity of appendicitis as depicted on CT and blood inflammatory markers of serum white blood cell (WBC) count and C-reactive protein (CRP).

METHODS

CT images in 128 patients (109 surgically proven and 19 with clinically excluded appendicitis) were retrospectively reviewed. Two radiologists by consensus evaluated and scored (using a 0, 1 or 2 point scale) severities based on CT-determined appendiceal diameters, appendiceal wall changes, caecal changes, periappendiceal inflammatory stranding and phlegmon or abscess formation. We investigated whether CT findings were significantly related to elevated WBC counts or CRP levels and performed the correlations of WBC counts and CRP levels with CT severity scores. Patients were also subjectively classified using four grades from normal (Grade I) to perforated appendicitis (Grade IV) on the basis of CT findings to evaluate differences in WBC counts and CRP levels between grades.

RESULTS

Only appendiceal wall changes and the phlegmon or abscess formation were related to elevated WBC counts and CRP levels, respectively (p<0.05). CT severity scores were found to be more strongly correlated with CRP levels (r = 0.669) than with WBC counts (r = 0.222). On the basis of CT grades, the WBC counts in Grade I were significantly lower than in other grades (p<0.001), whereas CRP levels in Grade IV were significantly higher than in other grades (p<0.001).

CONCLUSION

CRP levels were found to correlate with CT-determined acute appendicitis severity and could be a useful predictor for perforated appendicitis, whereas WBC counts might be useful to detect early acute appendicitis.

Energy spectra of a single-electron magnetic dot using the massless Dirac-Weyl equation

In this paper, we study the low-lying energy spectra of a two-dimensional (2D) graphene-based magnetic dot in a perpendicular and radially inhomogeneous magnetic field with the use of the massless Dirac-Weyl equation. Numerical calculations are performed using 2D harmonic basis states for direct diagonalization. Effects of both the dot size and the magnetic field on the low-lying energy spectra are discussed.

Aggregation in insect communities colonizing cattle-dung

Ruminant dung is a highly ephemeral, patchily distributed resource, which is used by a diverse community of invertebrate species. In such environments, high levels of insect aggregation may be important in facilitating stability and coexistence across patchily distributed populations. The aim of the present work was to quantify the aggregation of the insects colonising cow-dung in cattle pasture in southwest England and to test the hypothesis that the dung-pat community assemblage observed was the result of stochastic colonization. This was examined using batches of ten standardised, 1.5 kg, artificial cow pats placed out in cattle pastures in each of 24 weeks between May and October in 2001. Pats were left exposed in the field for seven days before being brought back to the laboratory, where any insect colonizers were collected and identified. Individual pats contained, on average, only half the number of insect taxa present in an entire batch put out at any one time. All larval coleopteran taxa, 20 of the 22 adult coleopteran taxa and 22 of the 23 dipteran taxa, showed significant aggregation, with the abundance of most taxa within pats approximating a negative binomial distribution. A simulation analysis was used to show that the observed relative frequency of taxa within pats did not differ from that expected by chance if colonisation is a random binomial event in which each species colonises a pat independently of all other species. Aggregated populations, of even highly abundant insects, may be more susceptible to the deleterious effects of insecticidal contaminants in dung than if they were evenly distributed, if by chance they colonize a pat containing insecticidal residues from a recently treated animal.

In vitro potential of Ascophyllum nodosum phenolic antioxidant-mediated alpha-glucosidase and alpha-amylase inhibition

Ascophyllum nodosum is a brown seaweed that grows abundantly in the Northeast coastal region. In this study, the potential of A. nodosum for type 2 diabetes management through antioxidant-mediated alpha-glucosidase and alpha-amylase inhibition was investigated. After the initial screening of 4 locally harvested seaweeds, A. nodosum was chosen for its highest phenolic content and was subjected to water extraction. Among extraction ratios of 50 g to 100 to 1000 mL at room temperature, 50 g/400 mL yielded the highest phenolic content of 4.5 mg/g wet weight. For evaluation of extraction temperature ranging from 20 to 80 degrees C, 50 g/400 mL was chosen as a minimum amount of extractant. Among temperatures studied, extraction at 80 degrees C resulted in the highest total phenolic contents (4.2 mg/g wet weight). All extracts had similar levels of antioxidant activity in the range of 60% to 70% in terms of 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The 80 degrees C extract had the highest alpha-glucosidase and alpha-amylase inhibitory activity with IC(50) of 0.24 and 1.34 microg phenolics, respectively, compared to the IC(50) of acarbose, reference inhibitor, being 0.37 and 0.68 microg. The results show that fresh A. nodosum has strong alpha-glucosidase and mild alpha-amylase inhibitory activities that correlated with phenolic contents. This study suggests a nutraceutical potential of A. nodosum based on phytochemical antioxidant and antihyperglycemia activities.

Covalently linked immunomagnetic separation/adenosine triphosphate technique (Cov-IMS/ATP) enables rapid, in-field detection and quantification of Escherichia coli and Enterococcus spp. in freshwater and marine environments

AIMS

Developing a rapid method for detection of faecal pollution is among the critical goals set forth by the Environmental Protection Agency in its revision of water quality criteria. The purpose of this study is to devise and test covalently linked antibody-bead complexes for faecal indicator bacteria (FIB), specifically Escherichia coli or Enterococcus spp., in measuring water quality in freshwater and marine systems.

METHODS AND RESULTS

Covalently linked complexes were 58-89% more robust than antibody-bead complexes used in previous studies. Freshwater and marine water samples analysed using covalently linked immunomagnetic separation/adenosine triphosphate quantification technique (Cov-IMS/ATP) and culture-based methods yielded good correlations for E. coli (R = 0·87) and Enterococcus spp. (R = 0·94), with method detection limits below EPA recreational water quality health standards for single standard exceedances (E. coli- 38 cells per 100 ml; Enterococcus spp. - 25 cells per 100 ml). Cov-IMS/ATP correctly classified 87% of E. coli and 94% of Enterococcus spp. samples based on these water quality standards. Cov-IMS/ATP was also used as a field method to rapidly distinguish differential loading of E. coli between two stream channels to their confluence.

CONCLUSIONS

Cov-IMS/ATP is a robust, in-field detection method for determining water quality of both fresh and marine water systems as well as differential loading of FIB from two converging channels.

SIGNIFICANCE AND IMPACT OF THE STUDY

To our knowledge, this is the first work to present a viable rapid, in-field assay for measuring FIB concentrations in marine water environments. Cov-IMS/ATP is a potential alternative detection method, particularly in areas with limited laboratory support and resources, because of its increased economy and portability.

Faecal indicator bacteria enumeration in beach sand: a comparison study of extraction methods in medium to coarse sands

AIMS

The absence of standardized methods for quantifying faecal indicator bacteria (FIB) in sand hinders comparison of results across studies. The purpose of the study was to compare methods for extraction of faecal bacteria from sands and recommend a standardized extraction technique.

METHODS AND RESULTS

Twenty-two methods of extracting enterococci and Escherichia coli from sand were evaluated, including multiple permutations of hand shaking, mechanical shaking, blending, sonication, number of rinses, settling time, eluant-to-sand ratio, eluant composition, prefiltration and type of decantation. Tests were performed on sands from California, Florida and Lake Michigan. Most extraction parameters did not significantly affect bacterial enumeration. anova revealed significant effects of eluant composition and blending; with both sodium metaphosphate buffer and blending producing reduced counts.

CONCLUSIONS

The simplest extraction method that produced the highest FIB recoveries consisted of 2 min of hand shaking in phosphate-buffered saline or deionized water, a 30-s settling time, one-rinse step and a 10 : 1 eluant volume to sand weight ratio. This result was consistent across the sand compositions tested in this study but could vary for other sand types.

SIGNIFICANCE AND IMPACT OF THE STUDY

Method standardization will improve the understanding of how sands affect surface water quality.