Quantitative determination of sterols and other alcohols in overland flow from grazing land and possible source materials

Organic marker compounds (biomarkers) can be used to identify the sources of waterborne pollutants. This paper examines sterols and other alcohols in overland flow from pasture-based grazing systems, possible agricultural source materials and water extracts of these source materials as a preliminary step to developing chemical profiles that can be used for tracing pollutants. The biomarkers were quantified using gas chromatography and gas chromatography-mass spectrometry techniques. Analyses of plant material show that some pasture species contain unique compounds, enabling their identification. For example, Arctotheca calendula (capeweed) contains an as yet unidentified compound (Arctotheca m/z 163). Other pasture species that do not contain unique compounds do contain unique ratios of phytol, hexacosanol, octacosanol and 24-ethylcholesterol, enabling their identification. Analyses of faecal samples show that the ratios of sterols to stanols enable faeces to be distinguished from the pasture species, e.g. the ratio of 24-ethylcholesterol to 24-ethylcoprostanol was <1, generally <0.25 for faeces, while for most pasture species this ratio was >4. Using this ratio, qualitative apportioning of the sources of pollutants in overland flow to vegetation or faeces could be performed, but only in extreme cases (i.e. when the ratio <1 or >4). Decaying organic matter and surface soil appear to contain a composite of plant and faecal sterols. Sterols, being sparingly soluble in water and surface active, were not expected to be present in overland flow samples. Surprisingly, cholesterol and 24-ethylcoprostanol were found in both the particulate and filtrate fractions of most overland flow and water extracts of most source materials. Using the ratios of sterols to stanols, particulate organic material in water could be traced back to its broader source, i.e. vegetation or faeces.     

Evaluation of oxidative stress biomarkers in hepatocytes of grey mullet inhabiting natural and polluted estuaries

The aim of the study was to evaluate the impact of environmental contaminants on oxidative stress biomarkers in hepatocytes of Indian estuarine water grey mullet, Mugil cephalus collected from unpolluted Kovalam and polluted Ennore estuaries. Initially, a comparison was made between the general water chemistry and environmental pollutants like heavy metals to identify the ecotype of the estuaries. Biomarker responses and bioaccumulation of metals were determined along with histological studies of fish hepatocytes to assess contamination impact. Water chemistry data with higher temperature, salinity, pH, biochemical oxygen demand, chemical oxygen demand and low dissolved oxygen and environmental pollutants with higher metal concentration (p < 0.05) were observed at Ennore than Kovalam indicating its polluted environment. A significant increase (p < 0.05) in lipid and protein oxidation markers, decrease (p < 0.05) in thiol status and antioxidant enzyme activities were observed in the Ennore fish hepatocytes compared to Kovalam counterpart. Bioaccumulation of heavy metals was significantly higher (p < 0.05) in fish from Ennore. Hepatocytes from Ennore also featured extensive lipid-type vacuolation, increased size and membrane disruption. All the findings highlighted the value of oxidative stress biomarkers and membrane disruption as the sensitive parameters of environmental pollutant contamination and their importance in biomonitoring of aquatic ecosystems. This is also the first such attempt reported at the cellular level from South India stressing the importance of biomarkers in biomonitoring programmes using fish hepatocytes as the model system.     

Are biomarkers of chronic alcohol misuse useful in the assessment of DWI recidivism status?

A first driving while impaired by alcohol (DWI) conviction is a key opportunity to identify offenders who are at high risk for recidivism. Detection of alcohol use disorder (AUD) is a major target of current DWI assessments. However, offenders frequently underreport their alcohol consumption, and use of biomarkers has been proposed as a more objective indicator. Among the best established are aspartate aminotranferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), mean corpuscular red blood cell volume (MCV), carbohydrate-deficient transferrin (CDT), and thiamine. To our knowledge, no research has directly verified whether AUD biomarkers predict DWI recidivism status. Using a cross-sectional design, this study tested three hypotheses related to the utility of biomarkers in DWI assessment.

Hypotheses

(1) DWI recidivists possess biomarkers indicative of greater prevalence of AUD compared to first-time offenders; (2) multiple biomarkers better differentiate first-time offenders from recidivists compared to individual biomarkers; and (3) biomarkers add significantly to the prediction of recidivism over and above psychosocial questionnaires.

Methods

First-time offenders (n = 49) and recidivists (n = 95) participated in the study. In addition to self-reported information on sociodemographic and driving characteristics, data from several AUD questionnaires were gathered: Michigan Alcoholism Screening Test, Alcohol Use Disorders Identification Test, Composite International Diagnostic Interview, and Timeline Follow-Back. Blood samples were collected to measure AST, ALT, GGT, MCV, CDT, and thiamine.

Results

AUD biomarkers, taken individually or in combination, did not indicate that recidivists had more frequent AUD compared to first-time offenders. Also, they failed to significantly differentiate first-time offenders from recidivists or predict recidivism status. Finally, the superiority of biomarkers over psychosocial AUD questionnaires was not supported in the laboratory setting.

Conclusion

The present findings suggest that biomarkers of chronic patterns of heavy drinking may not be adequate to capture the multiple processes that appear to promote recidivism (e.g., binge drinking, other risky behavioural and personality features). Despite their objectivity, caution is warranted in the interpretation of a positive score on these biomarkers in DWI assessment. Longitudinal research is needed to more comprehensively explore the relationship between positive biomarkers in first-time offenders and their risk of becoming recidivists.     

成岩阶段微生物作用及其油气地质意义

成岩阶段微生物发育及其对有机质的改造对于生物甲烷聚集、优质烃源岩形成具有重要意义。在综合近年对沉积成岩过程相关的微生物作用研究的基础上,以柴达木盆地三湖坳陷第四系为例,论述了成岩阶段微生物在生物甲烷生成、有机质富集保存、可溶有机质生成等方面的作用。柴达木盆地三湖坳陷第四系生物标志化合物降解参数与产甲烷菌特征标志物的关系,指示原始沉积有机质降解与甲烷菌发育,是第四系沉积物中生物气聚集的关键因素;与细菌来源生物标志化合物相对丰度的关系,反映成岩阶段微生物发育改变了原始有机质性质;与氯仿沥青“A”转化率以及饱和烃相对丰度的关系,表明微生物发育是第四系沉积物中可溶有机质的重要来源。     

Nanoparticles for improving cancer diagnosis

Despite the progress in developing new therapeutic modalities, cancer remains one of the leading diseases causing human mortality. This is mainly attributed to the inability to diagnose tumors in their early stage. By the time the tumor is confirmed, the cancer may have already metastasized, thereby making therapies challenging or even impossible. It is therefore crucial to develop new or to improve existing diagnostic tools to enable diagnosis of cancer in its early or even pre-syndrome stage. The emergence of nanotechnology has provided such a possibility. Unique physical and physiochemical properties allow nanoparticles to be utilized as tags with excellent sensitivity. When coupled with the appropriate targeting molecules, nanoparticle-based probes can interact with a biological system and sense biological changes on the molecular level with unprecedented accuracy. In the past several years, much progress has been made in applying nanotechnology to clinical imaging and diagnostics, and interdisciplinary efforts have made an impact on clinical cancer management. This article aims to review the progress in this exciting area with emphases on the preparation and engineering techniques that have been developed to assemble “smart” nanoprobes.     

Onset of mucosal, dermal, and general symptoms in relation to biomarkers and exposures in the dwelling: a cohort study from 1992 to 2002

We examined the associations between biomarkers of allergy and inflammation, indoor environment in dwellings, and incidence and remission of symptoms included in the sick building syndrome (SBS) and changes in the home environment of 452 adults who were followed from 1992 to 2002 within the Uppsala part of the European Community Respiratory Health Survey (ECRHS). The 10-year incidence (onset) of general, mucosal, and dermal symptoms was 8.5%, 12.7%, and 6.8%, respectively. Dampness or indoor molds at baseline was a predictor of incidence of general (relative risk [RR] = 1.98), mucosal (RR = 2.28), and dermal symptoms (RR = 1.91). Women had higher incidence of general (RR = 1.74) and mucosal symptoms (RR = 1.71). Indoor painting increased the incidence of general symptoms (RR = 1.62). Bronchial responsiveness (BR), eosinophil counts in blood, total IgE and eosinophilic cationic protein (ECP) in serum at baseline were predictors of incidence of SBS. At follow-up, BR, total IgE, and C-reactive protein (CRP ) were associated with increased incidence of SBS. Moreover, subjects with doctor-diagnosed asthma at baseline had a higher incidence of general (RR = 1.65) and mucosal symptoms (RR = 1.97). In conclusion, female gender, dampness or indoor molds, indoor painting, and biomarkers of allergy and inflammation were associated with a higher incidence of SBS symptoms, in particular mucosal symptoms. PRACTICAL IMPLICATIONS: The focus in Sweden on indoor environment issues over the last few decades has resulted in improvements in dwellings, and reduced tobacco smoking, which could be beneficial for public health. Reducing dampness and molds in the dwelling place is another important way of reducing occurrence of SBS symptoms in the general adult population. The association between the incidence of SBS symptoms and clinical biomarkers of allergy and inflammation suggests a common etiology between inflammatory diseases, including asthma, rhinitis, and SBS. Lastly, good agreement between self-reported and clinically diagnosed atopy indicates that questionnaire data on atopy can be used in epidemiological studies.