S U M M A R Y Adenocarcinomas are malignant tumors with glandular growth and/or supposed intracellular mucin as identified by periodic acid-Schiff (PAS) positivity. Gastric signet ring cell carcinomas are classified as diffuse type. A proportion of diffuse-type adenocarcinomas have previously been suggested to be of neuroendocrine origin. In the present study we examined gastric signet ring cell carcinomas for neuroendocrine differentiation. Of 11 gastric signet ring cell carcinomas, 8 contained areas with PAS-positive signet ring cells that also were immunoreactive for one or several neuroendocrine markers: synaptophysin, chromogranin A, and histidine decarboxylase, the latter an enterochromaffin-like (ECL) cell marker. Whereas PAS positivity was located in the central cytoplasm, neuroendocrine immunoreactivity was often located as a rim surrounding an otherwise nonimmunoreactive cytoplasm, presumed to represent the area with PAS-positive material. These findings indicate that signet ring cell carcinomas could be of neuroendocrine origin. We propose that signet ring cell carcinomas develop by gradual dedifferentiation from ECL cells via signet ring cells with neuroendocrine immunoreactivity toward signet ring cells where the cytoplasm mainly consists of PAS-positive material. This finding could have implications for the classification and understanding of gastric carcinogenesis. (J Histochem Cytochem 54:615-621, 2006)

Microdialysis of glycerol provides information about the extent and severity of intestinal damage after ischemia and about the ensuing recovery. The gut lumen is to be preferred as a site for placement of microdialysis catheters.

Spontaneously hypergastrinemic cotton rats (Sigmodon hispidus) develop tumors that have the phenotype of an adenocarcinoma but most likely originate from the enterochromaffin-like (ECL) cells. Among inbred animals ϳ50% of the females, but <1% of males develop spontaneous gastric carcinomas. Gastrin is the principle carcinogen in this model, as >4 months of hypergastrinemia results in carcinoma, but a gastrin receptor antagonist prevents carcinomas. Carcinomas can also be induced by partial corpectomy. In the present study, the insurmountable H2-receptor antagonist loxtidine (200 mg/kg/day) was given to male cotton rats for 6 months. The loxtidine-dosed animals developed hypergastrinemia, whereas control animals remained normogastrinemic. At termination, 4 of 5 cotton rats had cancer located to the oxyntic mucosa, whereas 1 animal had dysplasia. The gastric mucosa of all of the control animals was normal. In the dysplastic mucosa of loxtidine-dosed animals there was a marked increase in chromogranin A-positive cells, where numerous groups of cells also stained positive with the Sevier-Munger technique. In areas of high proliferation and cancer there were also histidine decarboxylase, chromogranin A, and Sevier-Munger-positive cells, altogether indicating an ECL cell origin of the tumors. This represents an interesting animal model where ECL cell-derived gastric cancer can be induced by pharmacological acid inhibition in 6 months.

Background Posttraumatic stress disorder (PTSD) has been shown to be elevated among first responders (Emergency Medical Services, fire service, police force) compared to the general population. Examining the prevalence of mental health issues in a work force with an elevated occupational risk is fundamental towards ensuring their wellbeing and implementing safeguard measures. The goal of this study is therefore to report the prevalence of depression, anxiety, posttraumatic development, and PTSD in Norwegian ambulance personnel. Methods This study is a cross-sectional, anonymous, web-based survey (Questback®), performed among operative personnel employed in the Emergency Medical Services in the Regional Health Trust of Central Norway between 18. February and 9. April 2021. The study was sent to 1052 eligible participants. Questions reported demographic data, a traumatic events exposure index, Patient Health Questionnaire-9 (Depression), Generalized Anxiety Disorder-7 scale, Posttraumatic symptom scale (PTSD) and Posttraumatic change scale. Results The response rate in this study was 45.5% (n = 479/1052). The mean age of respondents was 37.1 years (std. 11.1) and 52.8% (n = 253) were male. Of the respondents, 80.6% (n = 386) were married or had a partner, and 91.6% (n = 439) reported having access to a peer support programme, with 34.9% (n = 167) reporting that they had utilized peer support. In this study, 5% (n = 24) showed a prevalence of manifest posttraumatic stress disorder symptoms, while 8.6% (n = 41) reported moderate to severe depression and 2.9% (n = 14) presented moderate to severe symptoms of general anxiety. Of the respondents, 77.2% (n = 370) reported personal growth because of their work experiences. Conclusions This study indicates that Norwegian ambulance personnel report a prevalence of posttraumatic stress symptoms and depression, which is slightly higher for men, and lower for the female proportion in this study, when compared to an adult Norwegian population. The vast majority of respondents reported personal growth because of their work experience, and both the degree of peer support and having a partner seem to influence levels of posttraumatic stress and -development.