[Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]

BACKGROUND

Autopsies are a valuable tool for understanding disease, including COVID-19.

MATERIALS AND METHODS

The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs.

RESULTS

The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy.

CONCLUSIONS

Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.

Residual carcinoma cells after chemoradiotherapy for esophageal squamous cell carcinoma patients: striving toward appropriate judgment of biopsy

In esophageal squamous cell carcinoma (ESCC) patients who are treated with chemoradiotherapy (CRT), identification of the presence or absence of residual or recurrent carcinoma is usually pivotal in their clinical management. In addition, the extent of carcinoma invasion into the esophageal wall could determine the clinical outcome of these patients following CRT. Therefore, in this study, we evaluated the response to CRT both macroscopically and histologically in a consecutive series of 42 ESCC patients receiving neoadjuvant chemoradiotherapy following curative esophageal resection at Tohoku University Hospital between August 2011 and December 2012. The histological grading of tumor regression was as follows: grade 3, markedly effective (no viable residual tumor cells); grade 2, moderately effective (residual tumor cells in less than one-third of the tumor); grade 1, slightly effective (1b, residual tumor cells in one-third to two-thirds of the tumor; 1a, residual tumor cells in more than two-thirds of the tumor); and grade 0, ineffective. In this study, we selected grade 2 and 1b cases because they might show a complete response with definitive CRT. We evaluated the presence of any residual in situ lesions and tumor depth in detail. The grading of tumor regression in primary sites was as follows: grade 3 (7 cases), grade 2 (16 cases), grade 1b (13 cases), and grade 1a (6 cases). The concordance rate between macroscopic and histopathological evaluation on the depth of the tumor was 40% (17/42). Among 29 cases (grade 2 and grade 1b), intraepithelial lesions were not detected in 17 cases, and tumor nests were not detected in the lamina propria mucosae in 9 cases. The results of this study highlight the difficulties of detecting residual carcinoma cells using conventional endoscopic biopsy in patients who have received CRT. Therefore, when residual cancer is clinically suspected in patients who have received CRT, the biopsy specimen should be obtained from the deep layer of the esophagus whenever possible. Additionally, close follow-up is required using positron emission tomography/computed tomography, endoscopy, and other radiological evaluations.

The expression and function of histamine H₃ receptors in pancreatic beta cells

BACKGROUND AND PURPOSE

Histamine and its receptors in the CNS play important roles in energy homeostasis. Here, we have investigated the expression and role of histamine receptors in pancreatic beta cells, which secrete insulin.

EXPERIMENTAL APPROACH

The expression of histamine receptors in pancreatic beta cells was examined by RT-PCR, Western blotting and immunostaining. Insulin secretion assay, ATP measurement and calcium imaging studies were performed to determine the function and signalling pathway of histamine H₃ receptors in glucose-induced insulin secretion (GIIS) from MIN6 cells, a mouse pancreatic beta cell line. The function and signalling pathway of H₃ receptors in MIN6 cell proliferation were examined using pharmacological assay and Western blotting.

KEY RESULTS

Histamine H₃ receptors were expressed in pancreatic beta cells. A selective H₃ receptor agonist, imetit, and a selective inverse H₃ receptor agonist, JNJ-5207852, had inhibitory and facilitatory effects, respectively, on GIIS in MIN6 cells. Neither imetit nor JNJ-5207852 altered intracellular ATP concentration, or intracellular calcium concentration stimulated by glucose and KCl, indicating that GIIS signalling was affected by H3 receptor signalling downstream of the increase in intracellular calcium concentration. Moreover, imetit attenuated bromodeoxyuridine incorporation in MIN6 cells. The phosphorylation of cAMP response element-binding protein (CREB), which facilitated beta cell proliferation, was inhibited, though not significantly, by imetit, indicating that activated H₃ receptors inhibited MIN6 cell proliferation, possibly by decreasing CREB phosphorylation.

CONCLUSIONS AND IMPLICATIONS

Histamine H₃ receptors were expressed in mouse beta cells and could play a role in insulin secretion and, possibly, beta cell proliferation.

[Immunohistochemical evaluation of somatostatin receptor subtypes in surgical pathology specimens of neuroendocrine tumors]

The clinical development of specific/selective or more potent analogues of somatostatin has made the evaluation of somatostatin receptor subtypes in archival specimens or 10% formalin-fixed and paraffin-embedded specimens of neuroendocrine tumor (NET) critical to conferring the maximum clinical benefits on NET patients. Immunohistochemistry of somatostatin receptor subtypes could contribute to profiling their expression patterns in these patients. Therefore, surgical pathologists are expected to be asked to immunostain and evaluate somatostatin receptor subtypes in NET specimens in the near future by clinicians. However, there are problems associated with immunohistochemistry of somatostatin receptor subtypes, in particular with their evaluation and interpretation. Therefore, both pathologists and clinicians involved in the care or management of NET patients should be aware of the advantages and limitations of immunohistochemical evaluation of somatostatin receptor subtypes in order to achieve the most efficient treatment outcome for patients.