Histidine decarboxylase (HDC) from Lactobacillus 30a converts histidine to histamine, a process that enables the bacteria to maintain the optimum pH range for cell growth. HDC is regulated by pH; it is active at low pH and inactive at neutral to alkaline pH. The X-ray structure of HDC at pH 8 revealed that a helix was disordered, resulting in the disruption of the substrate-binding site. The HD...

Tourette syndrome (TS) is a polygenic neuropsychiatric disease. Previous studies have indicated that dysregulation in the histaminergic system may play a crucial role in disease onset. In this study, we investigated the role of the histidine decarboxylase gene (HDC) in TS susceptibility in the Chinese Han population. After genotyping 241 TS nuclear families trios, we analyzed three tag HDC sing...

Histamine is an important stimulator of gastric acid secretion. In experimental animals, inhibition of acid secretion by long term histamine2 receptor blockade causes hypergastrinemia, proliferation of enterochromaffin-like (ECL) cells, and formation of histamine-producing gastric carcinoids. The aim of this study was to examine the role of gastrin in histamine synthesis and metabolism of the o...

Gastric enterochromaffin-like (ECL) cells release histamine in response to food because of elevation of gastrin and neural release of pituitary adenylate cyclase-activating peptide (PACAP). Acid secretion is at a basal level in the absence of food but is rapidly stimulated with feeding. Rats fasted for 24 h showed a significant decrease of mucosal histamine despite steady-state expression of th...

Military sonars must detect, localize, classify, and track submarine threats from distances safely outside their circle of attack. However, conventional pulsed active sonars (PAS) have duty cycles on the order of one percent which means that 99% of the time, the track is out of date. In contrast, high duty cycle sonars (HDC) have duty cycles approaching 100% which enable near-continuous updates...

The purpose of this study is to determine if there is any benefit in disease-free survival (DFS) at 5 years of Stage III breast cancer patients who are treated with 2 sequential regimens of high-dose chemotherapy and peripheral blood stem cell (PBSC) transplant when compared with patients receiving conventional dose chemotherapy. Breast cancer affects 1in 8 women in the United States. 10-25% of...

In Brazil, Hansen's disease (HD) is still a public health problem. Although much progress has been made in Hansen's disease control (HDC) at all levels of government over the past 20 years, efforts have been hampered by information gaps related to specific areas of the disease, exacerbated by an absence of appropriate evaluation instruments and routine systematic analysis. Health Systems Resear...

We have investigated the expression and localization of histidine decarboxylase (HDC, a key enzyme for histamine biosynthesis) in human skin by immunohistochemical analysis. HDC-immunoreactive cytokeratin 14-non immunoreactive cells were observed around basal layer epidermis healthy subjects patients with atopic dermatitis (AD). These did not express mast cell-tryptase but expressed tyrosinase ...

Senescent human diploid cells (HDC) were fused to replicative transformed cells of different types, and DNA synthesis was monitored in the resulting heterodikaryons. Human cells transformed by simian virus 40 or adenovirus serotype 5 were able to induce DNA synthesis in senescent HDC nuclei in heterodikaryons. In contrast, carcinogen-transformed cells were not able to induce DNA synthesis in se...

To evaluate the role of high-dose chemotherapy (HDC) followed by autologous bone marrow transplantation (ABMT) in children with poor-prognosis Burkitt's lymphoma, the European Lymphoma BMT registry was critically reviewed. Between February 1979 and July 1991, a selected group of 89 children (78 boys and 11 girls) were considered as ABMT candidates in 12 European cancer centers for the following...