Miniature fluorescence sensor for quantitative detection of brain tumour

Fluorescence-guided surgery has emerged as a vital tool for tumour resection procedures. As well as intraoperative tumour visualisation, 5-ALA-induced PpIX provides an avenue for quantitative tumour identification based on ratiometric fluorescence measurement. To this end, fluorescence imaging and fibre-based probes have enabled more precise demarcation between the cancerous and healthy tissues. These sensing approaches, which rely on collecting the fluorescence light from the tumour resection site and its "remote" spectral sensing, introduce challenges associated with optical losses. In this work, we demonstrate the viability of tumour detection at the resection site using a miniature fluorescence measurement system. Unlike the current bulky systems, which necessitate remote measurement, we have adopted a millimetre-sized spectral sensor chip for quantitative fluorescence measurements. A reliable measurement at the resection site requires a stable optical window between the tissue and the optoelectronic system. This is achieved using an antifouling diamond window, which provides stable optical transparency. The system achieved a sensitivity of 92.3% and specificity of 98.3% in detecting a surrogate tumour at a resolution of 1 × 1 mm2. As well as addressing losses associated with collecting and coupling fluorescence light in the current 'remote' sensing approaches, the small size of the system introduced in this work paves the way for its direct integration with the tumour resection tools with the aim of more accurate interoperative tumour identification.

Parental Lead Exposure Promotes Neurobehavioral Disorders and Hepatic Dysfunction in Mouse Offspring

Lead (Pb) induces neurotoxicity in both children and adults. Children are more vulnerable to Pb toxicity than adults. Little is known about the effects of Pb on the mental health of the children who are prenatally exposed. Therefore, we designed an animal experiment to compare the adverse effects of Pb on neurobehavioral and hepatic functions between Pb-exposed (Pb mice) and parental Pb-exposed (P-Pb mice) group mice. Mice were treated with Pb-acetate (10 mg/kg bodyweight/day) via drinking water. Male mice from unexposed parents treated with Pb for 90 days were defined as Pb mice, whereas male mice from Pb-exposed parents treated with Pb for further 90 days were defined as P-Pb mice. Anxiety-like behavior and spatial memory and learning were assessed by elevated plus maze and Morris water maze. Serum hepatic enzyme activities and butyrylcholinesterase activity were measured by an analyzer. P-Pb mice displayed increased anxiety-like behavior and memory and learning impairments compared to Pb mice. BChE activity was significantly decreased in P-Pb mice compared to Pb mice. Pb levels in the brains of P-Pb mice were significantly higher than those of Pb mice. The activities of serum hepatic enzymes of P-Pb mice were also higher than those of Pb mice. Additionally, histopathology data revealed that hepatic tissue injury was more pronounced in P-Pb mice than in Pb mice. Thus, the results suggest that persistent exposure to Pb from fetus to adult causes more severe neurobehavioral changes and hepatic toxicities than adult exposure only.

Arsenic exposure-related hyperglycemia is linked to insulin resistance with concomitant reduction of skeletal muscle mass

BACKGROUND

Alargebodyof evidence has shown a link between arsenic exposure and diabetes, but the underlying mechanisms have not yet been clarified.

OBJECTIVE

We explored the association between arsenic exposure and the reduction of skeletal muscle mass as a potential mechanism of insulin resistance for developing arsenic-related hyperglycemia.

METHODS

A total of 581 subjects were recruited from arsenic-endemic and non-endemic areas in Bangladesh and their fasting blood glucose (FBG), serum insulin, and serum creatinine levels were determined. Subjects' arsenic exposure levels were assessed by arsenic concentrations in water, hair, and nails. HOMA-IR and HOMA-β were used to calculate insulin resistance and β-cell dysfunction, respectively. Serum creatinine levels and lean body mass (LBM) were used as muscle mass indicators.

RESULTS

Water, hair and nail arsenic concentrations showed significant positive associations with FBG, serum insulin and HOMA-IR and inverse associations with serum creatinine and LBM in a dose-dependent manner both in males and females. Water, hair and nail arsenic showed significant inverse associations with HOMA-β in females but not in males. FBG and HOMA-IR were increased with the decreasing levels of serum creatinine and LBM. Odds ratios (ORs)of hyperglycemia were significantly increased with the increasing concentrations of arsenic in water, hair and nails and with the decreasing levels of serum creatinine and LBM. Females' HOMA-IR showed greater susceptibility to the reduction of serum creatinine and LBM, possibly causing the greater risk of hyperglycemia in females than males. Path analysis revealed the mediating effect of serum creatinine level on the relationship of arsenic exposure with HOMA-IR and hyperglycemia.

CONCLUSION

Arsenic exposure elevates FBG levels and the risk of hyperglycemia through increasing insulin resistance with greater susceptibility in females than males. Additionally, arsenic exposure-related reduction of skeletal muscle mass may be a mechanism underlying the development of insulin resistance and hyperglycemia.

Association between chronic arsenic exposure and the characteristic features of asthma

Widespread contamination of arsenic (As) has become a global public health concern. Exposure to As causes respiratory complications. Asthma, a major respiratory complication, is increasing worldwide. However, the effect of chronic As exposure on the risk of asthma remains to be clarified. This study aims to examine the associations between As exposure (water, hair and nail As) and the risk of asthma among 842 individuals exposed to a wide range of As concentrations through drinking water in Bangladesh. Subjects' As exposure levels were measured with ICP-MS. Lung function was examined by a handheld spirometer. Characteristic features of asthma were evaluated by bronchodilator-mediated reversibility in airway obstruction and asthma-like symptoms through a structured questionnaire. Total serum immunoglobulin E (sIgE) levels were measured by immunoassay. As exposure metrics showed inverse associations with lung function measures (FEV1, FEV6, and FEV1/FEV6 ratio) and positive associations with the risks of airway obstruction (AO), reversible airway obstruction (RAO), and asthma-like symptoms. The majority of AO patients (70 of 97) were RAO with one or more characteristic symptoms of asthma. Intriguingly, subjects' As exposure levels showed positive associations with total sIgE levels. Total sIgE in RAO patients was significantly (p < 0.001) higher than that in the control group. Thus the results revealed that chronic As exposure was associated with the risk of the characteristic features of asthma. Additionally the association between As exposure and subjects' total sIgE levels and an elevated level of total sIgE in RAO group suggested that As exposure-related asthma might be allergic in nature.

Dose-dependent relationships between chronic arsenic exposure and cognitive impairment and serum brain-derived neurotrophic factor

BACKGROUND

Arsenic poisoning is a public health problem worldwide. A few studies have reported the effects of arsenic exposure on adult cognitive function, but with limitations in the subject selection and exposure markers. Moreover, information regarding the association between arsenic exposure and biomarker of cognitive impairment is scarce.

OBJECTIVES

We examined the associations between arsenic exposure and adult cognitive impairment using the Mini-Mental State Examination (MMSE) and the serum levels of brain-derived neurotrophic factor (BDNF), a potential biomarker of cognitive health status.

METHODS

We designed a cross-sectional study that recruited 693 adult (18-60 years old) subjects from the areas of low- and high‑arsenic exposure in rural Bangladesh. The subjects' arsenic exposure levels (drinking water, hair, and nail arsenic concentrations) were measured by inductively coupled plasma-mass spectroscopy. The Bangla version of the MMSE was used as a cognitive assessment tool. Serum BDNF (sBDNF) levels were assessed by immunoassay.

RESULTS

In this study, we found that average MMSE score and sBDNF level of the subjects in arsenic-endemic areas were significantly (p < 0.001 for both) lower than those of the subjects in non-endemic area. Our analyses revealed that both MMSE scores and sBDNF levels were decreased with the increasing concentrations of arsenic in drinking water, hair, and nails in a dose-dependent fashion. In regression analyses, significant associations of arsenic exposure metrics with MMSE scores and sBDNF levels were observed even after adjustment for several variables. Intriguingly, MMSE scores showed a significantly positive correlation with sBDNF levels.

CONCLUSION

Our findings demonstrate that chronic exposure to arsenic dose-dependently decreases cognitive function in adults, with a concomitant reduction of sBDNF levels. A decreased BDNF level may be part of the biochemical basis of chronic arsenic exposure-related cognitive impairment.