Long-term safety and efficacy of acotiamide in functional dyspepsia (postprandial distress syndrome)-results from the European phase 3 open-label safety trial.

BACKGROUNDS: Acotiamide is a novel acetylcholinesterase inhibitor for treatment of postprandial distress syndrome (PDS) symptoms of functional dyspepsia (FD). This European phase 3 open-label safety trial has been conducted to evaluate the long-term safety of acotiamide and explore the efficacy of acotiamide on PDS symptoms using the validated LPDS, quality of life using SF-36 and SF-NDI, and work productivity using WPAI. METHODS: FD-PDS patients (defined by ROME III criteria) aged ≥18 years with active PDS symptoms and without predominant overlapping symptoms of epigastric pain syndrome and related disorders were enrolled to receive 100 mg acotiamide three times daily for 1 year. Patients' safety profile and efficacy of acotiamide were monitored. KEY RESULTS: The majority of patients (81.6%) maintained exposure to acotiamide for >50 weeks, with a mean duration of 320.3 days. No specific clinically significant safety concerns have been shown, with no deaths, treatment-related severe/serious adverse events, or any clinically significant laboratory test results. Although being an open-label trial, acotiamide showed a change in severity larger than the minimum clinically important difference at weeks 1 and 2 for postprandial fullness and early satiation (meal-related symptoms), and showed improvement of quality of life and work productivity from the first measurement (at week 12) up to 1 year. CONCLUSIONS & INFERENCES: The long-term safety of acotiamide treatment was confirmed. A clinically important change for PDS symptoms, QoL, and work productivity was suggested; however a controlled trial is required to confirm this hypothetic efficacy of acotiamide. (NCT01973790).

Comparative studies of human recombinant 74- and 54-kDa L-histidine decarboxylases.

We have expressed and characterized human recombinant 74-kDa (rHDC74) and 54-kDa (rHDC54) L-histidine decarboxylases (HDCs) in Sf9 cells. By immunoblot analysis, rHDC74 and rHDC54 were shown to be localized predominantly in the particulate and soluble fractions, respectively. rHDC74 exhibited histamine-synthesizing activity equivalent to that of rHDC54. The existence of 74- and 54-kDa HDCs was also confirmed in the particulate and supernatant fractions of the cell lysate, respectively, from the human basophilic leukemia cell line KU-812-F. The ratio of HDC activity to immunoreactivity was similar for the two forms of the enzyme. The specific activity of purified rHDC54 (1.12 mumol/mg/min) was comparable to those of HDCs from other mammalian tissues or cells. The purified rHDC54 was eluted as a monomer form from a Superdex-200 column; the molecular mass of the enzyme was approximately 54 kDa on SDS-polyacrylamide gel electrophoresis without 2-mercaptoethanol. The HDC activity of rHDC54 significantly decreased on dialysis against buffer without pyridoxal 5'-phosphate; addition of pyridoxal 5'-phosphate to the dialysate readily increased in the enzyme activity to the original activity. Taken together, these results suggest that human HDC functions as both 74- and 54-kDa forms having equivalent HDC activity, which are localized in the particulate and soluble fractions, respectively, and that the latter form exhibits its activity as a monomer form.

Expression and characterization of human recombinant parental and mature L-histidine decarboxylases.

Human recombinant 74 kD parental (rHDC74) and 54 kD mature (rHDC54) histidine decarboxylases (HDCs) have been expressed in Sf9 cells and characterized. By immunoblot analysis, rHDC74 and rHDC54 were shown to be localized predominantly in the particulate and soluble fractions, respectively. rHDC74 exhibited histamine-synthesizing activity equivalent to that of rHDC54. An active particulate HDC was also detected in the pellets obtained from 10,000 and 100,000 g centrifugation of a cell lysate from the human basophilic leukemia cell line, KU-812-F (14 and 18% of the total activity, respectively). By four purification steps, rHDC54 was purified to homogeneity, as judged by silver staining of the SDS-polyacrylamide gel. The purified rHDC54 was eluted as a monomer form from a Superdex-200 FPLC column. The molecular mass of the enzyme was found to be approximately 54 kD on SDS-poly-acrylamide electrophoresis in the absence of 2-mercaptoethanol. Taken together, these results suggest that human HDC functions as both 74 and 54 kD forms having equivalent HDC activity, which are localized in the particulate and soluble fractions, respectively, and that the latter form exhibits its activity as a monomer form.

Structure of the L-histidine decarboxylase gene.

Two species of L-histidine decarboxylase (HDC) mRNA were found in the KU-812-F basophilic cell line, but only the 2.4-kilobase (kb) one encodes the functional HDC (Mamune-Sato, R., Yamauchi, K., Tanno, Y., Ohkawara, Y., Ohtsu, H., Katayose, D., Maeyama, K., Watanabe, T., Shibahara, S., and Takishima, T. (1992) Eur. J. Biochem. 209, 533-539). The 3.4-kb one encodes a truncated HDC protein and is also found in human leukemia-derived cell lines HEL and KCL-22. To clarify the mechanisms that regulate transcription of the HDC gene and generate the two species of mRNA, we have isolated genomic DNA clones coding for the HDC from human genomic libraries. Structural analysis of the isolated clones revealed that the human HDC gene is composed of 12 exons spanning approximately 24 kb. Genomic DNA blot analysis suggested that HDC is encoded by a single copy gene. The structural analysis also demonstrated that the heterogeneity of the HDC mRNA is caused by an insertion of the seventh intron sequence and alternative use of the splicing acceptor site at the 12th exon. The transcription start site of the HDC gene and the nucleotide sequences of the promoter and first exon regions were determined. We found a TATA-like sequence, a GC box, four CACC boxes, four GATA consensus sequences, and six leader-binding protein-1 binding motifs in the promoter region of the HDC gene.