Occurrence of filamentous fungi in drinking water: their role on fungal-bacterial biofilm formation

Water is indispensable to life and safe and accessible supply must be available to all. The presence of microorganisms is a threat to this commitment. Biofilms are the main reservoir of microorganisms inside water distribution systems and they are extremely ecologically diverse. Filamentous fungi and bacteria can coexist inside these systems forming inter-kingdom biofilms. This review has the goal of summarizing the most relevant and recent reports on the occurrence of filamentous fungi in water distribution systems along with the current knowledge and gaps about filamentous fungal biofilm formation. Special focus is given on fungal-bacterial interactions in water biofilms.     

Systems biological approaches to measure and understand vaccine immunity in humans

Recent studies have demonstrated the utility of using systems approaches to identify molecular signatures that can be used to predict vaccine immunity in humans. Such approaches are now being used extensively in vaccinology, and are beginning to yield novel insights about the molecular networks driving vaccine immunity. In this review, we present a broad review of the methodologies involved in these studies, and discuss the promise and challenges involved in this emerging field of “systems vaccinology.”     

Polyphosphate accumulation and cell-surface properties by autochthonous bacteria from Argentinian Patagonia

Bacteria persisting in environments contaminated with polycyclic aromatic hydrocarbons (PAHs) have developed physiological mechanisms to counteract environmental stress. Inorganic polyphosphate accumulation represents one of these possible mechanisms. Likewise, properties such as cell-surface hydrophobicity, auto-aggregation, biofilm formation and bioemulsifying activity could facilitate interaction of microorganisms with hydrophobic organic compounds. In this work, these physiological properties were compared in indigenous bacteria from polluted sediments from Argentinian Patagonia, which were cultivated in two culture media (LBm and JPP) as a way to improve in the next future the PAHs removal. The highest hydrophobicity values were obtained in Rhodococcus strains, while Bacillus sp. B18 showed the highest auto-aggregation percentage and emulsion index. The highest numerical values of biofilm formation were determined in Rhodococcus sp. F27, Pseudomonas sp. P26, and Gordonia sp. H19 either on hydrophilic or on hydrophobic support. The qualitative and quantitative polyP determinations confirmed the presence of this biopolymer in the strains evaluated. The highest intracellular phosphate mean values were obtained in Bacillus sp. B18 in LBm and Rhodococcus erythropolis 20 in JPP. The bacteria evaluated belonging to different genera showed significant differences in their cell-surface characteristics, bioemulsifying activity and polyP accumulation. The low-cost JPP culture medium was selected for future contaminant removal studies.     

Water intake, pleasure and water temperature in humans

The influence of water temperature on intake and affective ratings was explored in human subjects. Dehydration whether by profuse sweating (body weight loss: 289 +/- 11 g, N = 20) or mountain climbing (body weight loss: 1660 +/- 58 g, N = 20) resulted in the same intake. Maximal intake was observed for water at 15 degrees C with respectively 199.0 +/- 17.0 ml and 222.7 +/- 17.4 ml. Colder and warmer water was ingested to a lesser extent. When 20 subjects were allowed to mix water to their preferred temperature, they chose 14.9 +/- 1 degree C and drunk 211.0 +/- 19.5 ml. Votes on a pleasure/displeasure scale increased from 50 degrees C to 0 degree C. Cold water was therefore both more pleasureable and less drunk. Dehydration resulted in a negative alliesthesia for warm water. Positive alliesthesia for cold water was probably the result of hyperthermia rather than dehydration.     

Understanding diseases by mouse click: the promise and potential of computational approaches in Systems Biology

Computational modelling approaches can nowadays build large-scale simulations of cellular behaviour based on data describing detailed molecular level interactions, thus performing the space- and time-scale integrations that would be impossible just by intuition. Recent progress in the development of both experimental methods and computational tools has provided the means to generate the necessary quantitative data and has made computational methods accessible even to non-theorists, thereby removing a major hurdle that has in the past made many experimentalists hesitate to invest serious effort in formulating quantitative models. We describe how computational biology differs from classical bioinformatics, how it emerged from mathematical biology and elucidate the role it plays for the integration of traditionally separated areas of biomedical research within the larger framework of Systems Biology.     

An evaluation framework for Health Information Systems: human, organization and technology-fit factors (HOT-fit)

BACKGROUND AND PURPOSE: The realization of Health Information Systems (HIS) requires rigorous evaluation that addresses technology, human and organization issues. Our review indicates that current evaluation methods evaluate different aspects of HIS and they can be improved upon. A new evaluation framework, human, organization and technology-fit (HOT-fit) was developed after having conducted a critical appraisal of the findings of existing HIS evaluation studies. HOT-fit builds on previous models of IS evaluation--in particular, the IS Success Model and the IT-Organization Fit Model. This paper introduces the new framework for HIS evaluation that incorporates comprehensive dimensions and measures of HIS and provides a technological, human and organizational fit. METHODS: Literature review on HIS and IS evaluation studies and pilot testing of developed framework. The framework was used to evaluate a Fundus Imaging System (FIS) of a primary care organization in the UK. The case study was conducted through observation, interview and document analysis. RESULTS: The main findings show that having the right user attitude and skills base together with good leadership, IT-friendly environment and good communication can have positive influence on the system adoption. CONCLUSIONS: Comprehensive, specific evaluation factors, dimensions and measures in the new framework (HOT-fit) are applicable in HIS evaluation. The use of such a framework is argued to be useful not only for comprehensive evaluation of the particular FIS system under investigation, but potentially also for any Health Information System in general.     

Water transport in renal tubules is mediated by aquaporins

Water reabsorption in mammalian renal tubules is mediated by channel-forming membrane glycoproteins termed aquaporins (AQP). So far three different kinds of AQP have been described in renal tubules. AQP CHIP is localized to the luminal and contraluminal membranes of the proximal tubule and descending thin limb cells, i.e., in tubule segments that exhibit a constitutive high permeability to water that is insensitive to vasopressin. AQP-CD is present in subapical vesicles and the luminal membrane of collecting duct principal cells. Its intracellular distribution depends on vasopressin or hydration status of the animal and, thus, may represent the vasopressin-sensitive water channel. The basolateral integral protein (BLIP) may represent the vasopressin-insensitive water channel in basolateral membrane of collecting duct principal cells. The exact localization of a recently cloned homologue, WCH3, which may be either related to BLIP or represent yet another kind of AQP, is not known. Heterogeneity of aquaporins in the renal tubule may provide a molecular basis for the treatment of certain diseases with disturbances in water homeostasis.Abbreviations AQP aquaporin - CHIP28 28 kDa channelforming integral protein - WCH-CD water channel-collecting duct - BLIP basolateral integral protein - PT proximal tubule - DTL descending thin limbs Correspondence to: I. Saboli     

Staphylococcus aureus surface protein G (sasG) allelic variants: correlation between biofilm formation and their prevalence in methicillin-resistant S. aureus (MRSA) clones

Methicillin-resistant Staphylococcus aureus (MRSA) may persist for long periods due to biofilm formation. The objective of this study was to describe biofilm formation in association with the presence of S. aureus surface protein G (sasG) and its allelic variants in MRSA bacteraemia isolates from endemic (CC5, CC8, CC22) and sporadic clones in Spain (2008–2015). Crystal violet staining was used to assess biofilm formation; DNA microarray, RT-qPCR, and long-read whole genome sequencing were applied to determine the presence, expression and structure of sasG, respectively. The endemic CC5 and CC8 clones produced more biofilm than the sporadic clones; these endemic clones carried sasG allelic variant 1. Otherwise, sporadic clones, with less biofilm formation, showed either an absence of sasG (65%) or the presence of allelic variant 2 (35%). Variants 1 and 2 differed in the expression of sasG (1.56 ± 1.20 and 0.37 ± 0.32, respectively). The analysis of a large cohort of closed S. aureus genomes available on the NCBI database confirmed the distribution of the two allelic variants with low amino acid identity (68.1%) among endemic and sporadic clones. SasG variant 1 present in the major CC5 and CC8 clones was correlated with increased biofilm formation and may represent an important virulence determinant.     

Systems Biology and the Discovery of Diagnostic Biomarkers

Systems biology is an approach to the science that views biology as an information science, studies biological systems as a whole and their interactions with the environment. This approach, for the reasons described here, has particular power in the search for informative diagnostic biomarkers of diseases because it focuses on the fundamental causes and keys on the identification and understanding of disease- perturbed molecular networks. In this review, we describe some recent developments that have used systems biology to address complex diseases – prion disease and drug induced liver injury- and use these as examples to illustrate the importance of understanding network structure and dynamics. The knowledge of network dynamics through in vitro experimental perturbation and modeling allows us to determine the state of the networks, to identify molecular correlates, and to derive new disease treatment approaches to reverse the pathology or prevent its progress into a more severe state through the manipulation of network states. This general approach, including diagnostics and therapeutics, is becoming known as systems medicine.     

Water as entrainer of circadian running activity in rat

The present work is designed to study the competing influence of periodic presentation of water on the running activity of the rat having free access to the cues fulfilling his instinctual drives, namely, food, water, male rat and primed female. Seven male, adult albino rats were used for the study. The 24 hour activity shift patterns of the incentive drives for food, water, male rat and primed female were recorded with the help of a maze-cum-activity cage with an automatic recording system fabricated in the laboratory, and under different schedules of periodic presentation of water. It was observed that the activity pattern shifted towards the drinking period with burst of running preceding water presentation. The findings of this study show that periodic water presentation is as significant as periodic food presentation in entraining the circadian running activity of the rat.     

Systems biology: integrating technology,biology, and computation

The Human Genome Project has changed the worlds of biology and medicine-helping to catalyze two major paradigm changes: systems biology and predictive, preventive and personalized medicine. These two themes will dominate 21st century biology and medicine. I will discuss these changes and indicate how they may interface with with the process of aging.     

An update on recent developments in the prevention and treatment of Staphylococcus aureus biofilms

Staphylococcus aureus (S. aureus) readily forms biofilms on prosthetic devices such as the pacemakers, heart valves, orthopaedic implants, and indwelling catheters. Its biofilms are recalcitrant to antibiotic therapy and pose a serious burden in the healthcare setting as they drastically increase the treatment cost and morbidity of the patient. Prevention and treatment of staphylococcal biofilms has therefore been an area of active research for the past two decades. While catheters coated with different antiseptics and antibiotics capable of preventing S. aureus biofilm formation have been developed, an effective therapy for the dispersal and treatment of established staphylococcal biofilms is not yet available. Hence, many studies have focused on developing novel therapeutic strategies that can tackle established S. aureus biofilm associated infections. This has led to the identification of different phytochemicals (e.g., tannic acid, ellagic acid, xanthohumol etc), enzymes (e.g., Dnases, lysostaphin, α-amylase, hyaluronidase and proteases etc.), sulfahydrl compounds (e.g., dithiothreitol, 2-mercaptoethanol), nanoparticles (e.g., gold, silver, iron, copper and selenium), phage cocktails, antibodies and metal chelators. Apart from the conventional techniques, the therapeutic effects of ultra sound, shock waves and photodynamic therapy for treating S. aureus biofilms are also being investigated. Clinical validation of these studies will equip the medical field with alternate preventive and treatment methods against staphylococcal biofilm infections. This review provides recent updates on the preventive and therapeutic strategies explored to eradicate staphylococcal biofilm formation and related infections.     

注水式结肠镜与传统注气式结肠镜在肠镜检查中的对比分析

目的 探究注气式与注水式结肠镜在结肠镜检查中的差异。方法 选取2016年6月~2017年8月我院消化科进行的非麻醉下结肠镜检查者300例,使用随机数表法分为注水组及注气组,各150例,两组分别采用注气式及注水式结肠镜检查方法。观察两组患者结肠镜检查的总时间,进镜时间、退镜时间及腹痛程度,并记录两组患者在检查过程中改变体位、腹部按压及硬度调节使用辅助操作的情况。结果 对照组操作成功率93.33%与观察组92.00%对比,差异无统计学意义(P＞0.05),注水组的检查总时间（17.2±4.1）min,进镜时间（23.1±6.3）min、退镜时间（10.5±4.7）min,高于注气组（14.2±5.4）min、（6.2±2.1）min 、（8.6±9）min;注水组VAS评分（3.87±1.59）分优于注气组（5.56±1.03）分,差异有统计学意义(P＜0.05);在使用辅助操作频率方面,注气组总使用率58.67%及腹部按压率10.00%与注水组34.67%、8.00%对比,差异无统计学意义（P＞0.05）。注气组体位改变40.00%及硬度调节8.67%,高于注水组23.33%、3.33%,差异有统计学意义（P＜0.05）。结论 注水式结肠镜检查在不影响检查准确性的前提下,可减少受检者痛苦程度及操作复杂程度,值得临床推广。     

Glycosaminoglycans and PDGF Signaling in Mesenchymal Cells

Platelet derived growth factor (PDGF) is involved in the autocrine growth stimulation of normal and malignant cells, the stimulation of angiogenesis, and the recruitment and regulation of tumor fibroblasts. PDGF has been shown to physically interact with glycosaminoglycans which are abundant in the extracellular microenvironment. The present review discusses the effects of glycosaminoglycans on the functions mediated by the PDGF on cells of mesenchymal origin. Recent studies have demonstrated that both soluble and surface bound glycosaminoglycan chains can modulate PDGF-BB isoform signaling depending on the cell type. These data demonstrated that the microenvironment rich in GAGs/PGs is able to significantly modify the cellular response to PDGF-BB signaling in a critical way for cell growth and differentiation.     

Water intake regulation in rats after intestinal bypass surgery

Jejunoileal bypass surgery in normal-weight female rats produced a temporary reduction in food intake, and small but more long lasting reductions in water intake and the water to food intake ratio. The bypass rats, however, did not differ from controls in their drinking response in a variety of thirst tests. That is, the bypass rats displayed normal increases in water intake following 24 hr water deprivation, hypertonic saline injection, or injection of polyethylene glycol; and normal decreases in water intake when food deprived or when given quinine-adulterated water. On the other hand, the bypass rats did not drink as much as did the controls when offered isotonic saline, or a saccharin solution for 24 hr/day, or when tested for schedule-induced-polydipsia 3 hr/day. The results indicate that bypassing a large segment of the jejunum and ileum does not disrupt regulatory drinking in the rat, but it does limit their ability to consume large volumes of fluid.     

水溶性止血纺织材料对血小板和血栓形成的影响

水溶性止血纺织材料是脱脂纤维素经化学处理而成，具有生物止血活性。作者研究了该类止血材料对血小板粘附及体外血栓形成的影响。止血纺织材料在液体中形成胶体颗粒并吸附激活血小板，参与止血过程，血小板粘附率约５０％。体外血栓形成试验表明，在凝血机制发生障碍的情况下，Ｓ－９９和Ｓ－１００止血纺织材料仍能形成血栓，明显比海藻类止血材料要好。     

Water permeability in human airway epithelium

Osmotic water permeability (P_f) was studied in spheroid-shaped human airway epithelia explants derived from nasal polyps by the use of a new improved tissue collection and isolation procedure. The fluid-filled spheroids were lined with a single cell layer with the ciliated apical cell membrane facing the outside. They were capable of surviving hours of experiment involving continuous superfusion of the bathing medium and changes of osmolarity. A new image analysis technique was developed for measuring the spheroid diameters, giving high time and measurement resolutions. The transepithelial P_f, determined by the changes of the apical solution osmolarity, was not influenced by the presence of glucose, Na⁺, or Na⁺/glucose-cotransport inhibitors in the bath, but was sensitive to the aquaporin (AQP) inhibitor HgCl₂. The measured P_f levels and the values of activation energy were in the range of those seen in AQP-associated water transport. Together, these results indicate the presence of an AQP in the apical membrane of the spheroids. Notably, identical values for P_f were found in CF and non-CF airway preparations, as was the case also for the calculated spontaneous fluid absorption rates.     

壳聚糖及其水溶性衍生物的细胞毒性研究

目的：研究壳聚糖及其水溶性衍生物的细胞毒性。方法：在碱性条件下，分别用溴代异丁烷和氯乙酸对壳聚糖进行化学修饰；采用细胞生长抑制法测定壳聚糖与水溶性的异丁基壳聚糖、羧甲基壳聚糖的细胞毒性。结果：壳聚糖及其水溶性衍生物对细胞的毒性为零级。结论：壳聚糖及其水溶性衍生物无细胞毒性。     

水溶性O-羟乙基壳聚糖接枝聚乳酸的制备与表征

目的制备用于组织工程的水溶性O-羟乙基壳聚糖／聚乳酸共聚物纤维复合支架。方法首先采用壳聚糖与环氧乙烷反应制备水溶性O-羟乙基壳聚糖,然后以辛酸亚锡为催化剂,水溶性O-羟乙基壳聚糖为引发剂,采用本体封管聚合法,激发D,L-丙交酯开环聚合制备水溶性O-羟乙基壳聚糖-g-聚乳酸共聚物。分别用X射线衍射、红外光谱、扫描电镜和溶解实验对产物的结构与性能进行分析表征。结果改性后的水溶性O-羟乙基壳聚糖能明显提高溶解性能,降低结晶性能和氢键间的相互作用。结论通过改性,为得到水溶性O-羟乙基壳聚糖／聚乳酸共聚物奠定了有利条件,并且此共聚物具有较好的孔隙率和网状结构,这对作为药物支架是一个很好的应用。此外,改性后的共聚物易溶于一些常用的有机溶剂中,有利于以后在组织工程中进一步应用。