Usefulness of HeLa cells to evaluate inverse agonistic activity of antihistamines.

Antihistamines are thought to antagonize histamine and prevent it from binding to the histamine H1 receptor (H1R). However, recent studies indicate that antihistamines are classified into two groups, i.e., inverse agonists and neutral antagonists on the basis of their ability to down-regulate the constitutive activity of H1R. As H1R is an allergy-sensitive gene whose expression influences the severity of allergic symptoms, inverse agonists should more potently alleviate allergic symptoms than neutral antagonists by inhibiting H1R constitutive activity. Therefore, it is important to assess inverse agonistic activity of antihistamines. Here we report a novel assay method using HeLa cells expressing H1R endogenously for evaluation of inverse agonistic activity of antihistamines. Pretreatment with inverse agonists down-regulated H1R gene expression below to its basal level. On the other hand, basal H1R mRNA expression was unchanged by neutral antagonist pretreatment. Both inverse agonists and neutral antagonists suppressed histamine-induced H1R mRNA elevation. Classification of antihistamines on the basis of their suppressive activity of basal H1R gene expression was consistent with that of inositol phosphate accumulation in H1R-overexpressed cells. Our data suggest that the assay method using HeLa cells is more convenient and useful than the existing methods and may contribute to develop new antihistamines with inverse agonistic activity.

Preseasonal prophylactic treatment with antihistamines suppresses IL-5 but not IL-33 mRNA expression in the nasal mucosa of patients with seasonal allergic rhinitis caused by Japanese cedar pollen.

CONCLUSIONS: These findings suggest that the down-regulation of interleukin (IL)-5 gene expression in collaboration with the suppression of histamine H(1) receptor (H1R) gene expression in the nasal mucosa provides the basis for better therapeutic effects of preseasonal prophylactic treatment with antihistamines in patients with seasonal allergic rhinitis caused by Japanese cedar pollen. OBJECTIVES: The effects of prophylactic administration of antihistamines on the expression of IL-5 and IL-33 mRNA in the nasal mucosa of the patients with pollinosis were investigated. METHODS: Eight patients had already visited the hospital before the peak pollen period and started preseasonal prophylactic treatment with antihistamines. Seventeen patients who first visited the hospital during the peak pollen period were designated as the no treatment group. After local anesthesia, nasal mucosa was obtained by scraping the inferior concha with a small spatula during the peak pollen period. RESULTS: During the peak pollen period, the expression of IL-5 mRNA, but not that of IL-33 mRNA, in the nasal mucosa of patients receiving preseasonal prophylactic treatment with antihistamines was significantly lower in comparison with that of patients without treatment. Moreover, there was a significant correlation between the expression of IL-5 mRNA and the nasal symptoms or the expression of H1R mRNA.

[Cetuximab-associated skin ulceration in patient with metastatic colorectal cancer: a case report].

An 82-year-old female was diagnosed with rectal cancer. Hartmann's procedure was performed and a curative resection was successfully achieved. Postoperative staging according to the classification of the Japanese Society for Cancer of the Colon and Rectum(The 7th Edition)was stage III. She received adjuvant chemotherapy after surgery with tegafur(UFT 300 mg/body/day)orally for 6 months. One year after the surgery, paraaortic lymph node metastasis and a local recurrence were diagnosed. She was treated with modified FOLFOX6 chemotherapy combined with bevacizumab. After 13 courses of treatment with FOLFOX6 and bevacizumab, multiple lung metastases were found. Therefore, we changed the chemotherapy regimens to FOLFIRI plus cetuximab. After 18 weeks of this new treatment she had two skin ulcerations around her stoma, a known side effect associated with cetuximab. We stopped cetuximab and continued chemotherapy with FOLFIRI alone. Seven weeks after cetuximab withdrawal, her skin ulcer healed with the support of a dermatologist and a wound ostomy continence nurse. We reintroduced cetuximab in a chemotherapy regimen with a reduced dose. After two infusions of cetuximab, skin ulceration recurred. We stopped cetuximab again and continued chemotherapy with FOLFIRI. Nine weeks later we resumed cetuximab, but this time the skin ulcer did not occur, and we were able to continue the chemotherapy regimen with FOLFIRI and cetuximab.

Albizia lebbeck suppresses histamine signaling by the inhibition of histamine H1 receptor and histidine decarboxylase gene transcriptions.

Histamine plays major roles in allergic diseases and its action is mediated mainly by histamine H(1) receptor (H1R). We have demonstrated that histamine signaling-related H1R and histidine decarboxylase (HDC) genes are allergic diseases sensitive genes and their expression level affects severity of the allergic symptoms. Therefore, compounds that suppress histamine signaling should be promising candidates as anti-allergic drugs. Here, we investigated the effect of the extract from the bark of Albizia lebbeck (AL), one of the ingredients of Ayruvedic medicines, on H1R and HDC gene expression using toluene-2,4-diisocyanate (TDI) sensitized allergy model rats and HeLa cells expressing endogenous H1R. Administration of the AL extract significantly decreased the numbers of sneezing and nasal rubbing. Pretreatment with the AL extract suppressed TDI-induced H1R and HDC mRNA elevations as well as [(3)H]mepyramine binding, HDC activity, and histamine content in the nasal mucosa. AL extract also suppressed TDI-induced up-regulation of IL-4, IL-5, and IL-13 mRNA. In HeLa cells, AL extract suppressed phorbol-12-myristate-13-acetate- or histamine-induced up-regulation of H1R mRNA. Our data suggest that AL alleviated nasal symptoms by inhibiting histamine signaling in TDI-sensitized rats through suppression of H1R and HDC gene transcriptions. Suppression of Th2-cytokine signaling by AL also suggests that it could affect the histamine-cytokine network.

[Elderly patient with recurrent rectal cancer successfully responded to modified FOLFOX6 chemotherapy with bevacizumab--a case report].

An 80-year-old female visited our hospital with the chief complaint of lower abdominal pain and diarrhea. She was diagnosed to have rectal cancer. Hartmann operation was performed and curative resection was successfully achieved. Postoperative stage was III according to the classification of the Japanese Society for Cancer of the Colon and Rectum(The 7th Edition). She was treated with oral tegafur(UFT 300mg/body/day)as adjuvant chemotherapy for 6 months. Paraaortic lymph node metastasis and local recurrence were diagnosed by abdominal CT 1 year after the surgery. Her performance status score was 0. She was treated with modified FOLFOX6 chemotherapy combined with bevacizumab. Abdominal CT revealed a partial response after 5 courses. She experienced grade 2 leukocyopenia, grade 3 neutropenia, grade 2 proteinuria and grade 2 hypertension.