A parasitological study on the possible toilet ruins of the Japanese colonial period in Korea.

In the past decade, experts have conducted parasitological research on archaeological specimens in Korea to collect historical parasite infection data. In these studies, parasitologists successfully described the infection pattern of each parasite species in history. However, in the first half of the 20th century, archaeoparasitological reports have been scant. In 2021, we conducted a parasitological examination of a toilet-like structure that emerged in the early 20th century. This structure was built by stacking 2 wooden barrels; and in the study samples, we found ancient Trichuris trichiura, Ascaris lumbricoides (unfertilized), and Taenia spp. eggs and therefore proposed a higher possibility that the barrels could have been used as a toilet at the time. To understand how the antihelminthic campaign since the 1960s helped reduce parasite infection rates in Korea, more research should focus on early-20th-century toilet ruins.

Neuroanatomical assessment of the impact of negative emotion on explicit memory in patients with obsessive-compulsive disorder.

The aim of this study was to identify the brain activation patterns associated with emotionally neutral or unpleasant words during explicit memory tasks in patients with obsessive-compulsive disorder (OCD) using a functional MRI. Sixteen patients with OCD (mean age=31.4±10.1 years) and 16 healthy controls (mean age=32.6±5.8 years) who had no history of neurological or psychiatric illness underwent functional MRI examinations on a 3-T Siemens MR Scanner. The stimulation paradigm consisted of five times rest-condition, two times encoding of two-syllable words, and two times explicit retrieval of the previously learned words. Six different words were presented for 3 s each in the encoding and retrieval tasks. In the retrieval task, the same words as those used at the encoding task were presented randomly. Brain activation maps were quantified and analyzed using SPM8 and MRIcron software. During the explicit retrieval tasks with emotionally neutral words, the predominant activation areas observed in patients with OCD included the angular gyrus and the supramarginal gyrus, whereas healthy controls showed significantly higher activity in the postcentral gyrus (P<0.005). During the explicit retrieval tasks with unpleasant words, patients with OCD showed significantly higher activity, compared with healthy controls, in the cerebellum, posterior cingulate gyrus, middle occipital gyrus, middle temporal gyrus, and inferior frontal gyrus (P<0.005); however, no predominant activation areas in healthy controls over patients with OCD were observed. This study showed differential brain activation patterns in response to emotionally neutral and unpleasant words in patients with OCD. This finding will be useful in assessing the neural mechanisms associated with emotional effect on the impairment of memory retrieval in OCD.