ABSTRACT
INTRODUCTION: Gallbladder carcinoma (GBC) and cholangiocarcinoma are aggressive forms of cancer developed in the gallbladder and biliary tracts which are related to the liver. This systematic review aimed to highlight the significant association between gallbladder, biliary cancers, and arsenic exposure. METHODS: An extensive search was conducted in Embase, Cochrane, Scopus, PubMed, and Web of Science. We included studies that assessed arsenic levels in gallbladder cancer patients, without restrictions on age, sex, or language. Biological samples, such blood, bile, gallbladder tissue, gallstones, and hair were obtained, and arsenic levels were measured. Also, arsenic water and soil concentrations were collected. RESULTS: A total of 13 studies were included in our review. These studies included 2234 non-gallbladder carcinoma patients and 22 585 gallbladder carcinoma cases. The participant demographics showed a gender distribution of 862 males and 1845 females, with an age range of 20-75 years. The average body mass index (BMI) was 19.8 kg/m2 for nongallbladder carcinoma patients and 20.1 kg/m2 for gallbladder carcinoma cases. The selected studies examined arsenic concentrations across various biological samples, including blood, hair, gallstones, and bile. Blood arsenic levels ranged from 0.0002 to 0.3893 µg/g and were significantly associated with increased gallbladder carcinoma risk in several studies. Hair also demonstrated a significant correlation, with arsenic concentrations ranging from 0.0002 to 6.9801 µg/g. CONCLUSION: There is a strong link between arsenic exposure and gallbladder cancer or cholangiocarcinoma. Even chronic exposure to low-moderate amounts could lead to gallbladder carcinoma. These findings stress the need for more comprehensive and dedicated studies, to control arsenic water/soil levels and seek other preventive measures for this high mortality disease.
ABSTRACT
An observer's pupil dilates and constricts in response to variables such as ambient and focal luminance, cognitive effort, the emotional stimulus content, and working memory load. The pupil's memory load response is of particular interest, as it might be used for estimating observers' memory load while they are performing a complex task, without adding an interruptive and confounding memory test to the protocol. One important task in which working memory's involvement is still being debated is visual search, and indeed a previous experiment by Porter, Troscianko, and Gilchrist (Quarterly Journal of Experimental Psychology, 60, 211-229, 2007) analyzed observers' pupil sizes during search to study this issue. These authors found that pupil size increased over the course of the search, and they attributed this finding to accumulating working memory load. However, since the pupil response is slow and does not depend on memory load alone, this conclusion is rather speculative. In the present study, we estimated working memory load in visual search during the presentation of intermittent fixation screens, thought to induce a low, stable level of arousal and cognitive effort. Using standard visual search and control tasks, we showed that this paradigm reduces the influence of non-memory-related factors on pupil size. Furthermore, we found an early increase in working memory load to be associated with more efficient search, indicating a significant role of working memory in the search process.
