Excessive alcohol consumption is associated with spontaneous burning pain, hyperalgesia and allodynia. Although acetaldehyde has been implicated in the painful alcoholic neuropathy, the mechanism by which the ethanol metabolite causes pain symptoms is unknown. Acute ethanol ingestion caused delayed mechanical allodynia in mice. Inhibition of alcohol dehydrogenase (ADH) or deletion of transient receptor potential ankyrin 1 (TRPA1), a sensor for oxidative and carbonyl stress, prevented allodynia. Acetaldehyde generated by ADH in both liver and Schwann cells surrounding nociceptors was required for TRPA1-induced mechanical allodynia. Plp1-Cre;Trpa1^fl/fl mice with a tamoxifen-inducible specific deletion of TRPA1 in Schwann cells revealed that channel activation by acetaldehyde in these cells initiates a NADPH oxidase-1 (NOX-1)-dependent production of hydrogen peroxide (H2O2) and 4-hydroxynonenal (4-HNE), which sustains allodynia by paracrine targeting of nociceptor TRPA1. Chronic ethanol ingestion caused prolonged mechanical allodynia and loss of intraepidermal small nerve fibers in WT mice. While Trpa1^-/- or Plp1-Cre;Trpa1^fl/fl mice did not develop mechanical allodynia, they did not show any protection from the small fiber neuropathy. Human Schwann cells express ADH/TRPA1/NOX1 and recapitulate the proalgesic functions of mouse Schwann cells. TRPA1 antagonists might attenuate some symptoms of alcohol-related pain.

Primary Neuroendocrine Tumours (NETs) of the gallbladder are rare. Among all NETs of the gallbladder, large cell neuroendocrine carcinoma (LCNEC) is exceedingly rare. In most of the cases LCNECs are combined with other histological components. We reviewed clinical presentation and management of all patients with "pure" LCNEC from published literature since the first case was published in 2000, as well as one patient from our experience. Only 7 cases of "pure" LCNEC has been described in the last 15 years, our case is the eighth. The diagnosis of gallbladder NETs is rarely made preoperatively since the presentation generally consists of non-specific symptoms including upper abdominal pain, discomfort, jaundice, weight loss. The majority of patients are identified incidentally at the time of cholecystectomy for cholelithiasis. It is not possible to differentiate preoperatively between gallbladder adenocarcinoma and gallbladder neuroendocrine carcinoma (NEC) with imaging techniques. The only curative therapeutic modality for LCNECs is a complete en bloc surgical resection, including regional lymph node clearances and hepatic lobectomy, but only in patients without multiple metastasis. LCNECs benefit from an aggressive surgical resection in combination with chemotherapy, if resectability is possible. If the tumour is non-resectable, the primary management is therefore medical and not surgical. All patients with LCNEC presented a poor prognosis with a median survival of 10 months after the initial diagnosis. Only in five patients (62.5%) a wide surgical excision was performed, while in the other cases the tumour was non-resectable or multiple liver metastases were present at diagnosis.

Macrophages (MΦs) and reactive oxygen species (ROS) are implicated in carcinogenesis. The oxidative stress sensor, transient receptor potential ankyrin 1 (TRPA1), activated by ROS, appears to contribute to lung and breast cancer progression. Although TRPA1 expression has been reported in melanoma cell lines, and oxidative stress has been associated with melanocytic transformation, their role in melanoma remains poorly known. Here, we localized MΦs, the final end-product of oxidative stress, 4-hydroxynonenal (4-HNE), and TRPA1 in tissue samples of human common dermal melanocytic nevi, dysplastic nevi, and thin (pT1) and thick (pT4) cutaneous melanomas. The number (amount) of intratumoral and peritumoral M2 MΦs and 4-HNE staining progressively increased with tumor severity, while TRPA1 expression was similar in all samples. Hydrogen peroxide (H₂O₂) evoked a TRPA1-dependent calcium response in two distinct melanoma cell lines (SK-MEL-28 and WM266-4). Furthermore, H₂O₂ induced a TRPA1-dependent H₂O₂ release that was prevented by the TRPA1 antagonist, A967079, or Trpa1 gene silencing (siRNA). ROS release from infiltrating M2 MΦs may target TRPA1-expressing melanoma cells to amplify the oxidative stress signal that affects tumor cell survival and proliferation.