Reduction of acetylcholine in the hippocampus of hippocampal cholinergic neurostimulating peptide precursor protein knockout mice.

The cholinergic efferent network from the medial septal nucleus to the hippocampus plays an important role in learning and memory processes. This cholinergic projection can generate theta oscillations in the hippocampus to encode novel information. Hippocampal cholinergic neurostimulating peptide (HCNP), which induces acetylcholine (Ach) synthesis in the medial septal nuclei of an explant culture system, was purified from the soluble fraction of postnatal rat hippocampus. HCNP is processed from the N-terminal region of a 186-amino acid, 21-kDa HCNP precursor protein, also known as Raf kinase inhibitory protein and phosphatidylethanolamine-binding protein 1. Here, we confirmed direct reduction of Ach release in the hippocampus of freely moving HCNP-pp knockout mice under an arousal state by the microdialysis method. The levels of vesicular acetylcholine transporter were also decreased in the hippocampus of these mice in comparison with those in control mice, suggesting there was decreased incorporation of Ach into the synaptic vesicle. These results potently indicate that HCNP may be a cholinergic regulator in the septo-hippocampal network.

Transvaginal ultrasonography of the endometrium in postmenopausal Japanese women.

AIMS: To determine the cut-off level of endometrial thickness for detecting endometrial disease on a large scale of screening and to examine the usefulness of transvaginal ultrasonography (TVS) for endometrial disease screening in asymptomatic postmenopausal Japanese women. METHODS: The study involved 1,400 postmenopausal women in whom endometrial thickness was measured with TVS, and then compared with the histopathological diagnosis of endometrial specimens. RESULTS: The prevalence of endometrial disease in asymptomatic and symptomatic cases was 2.3 and 21%. In symptomatic cases, at a cut-off limit of 3 mm for endometrial thickness, the sensitivity for detecting endometrial disease was 94%, specificity 70% and positive predictive value 46%. With an endometrial thickness < or = 3 mm, the probability that endometrial disease would be overlooked was 0.025. In asymptomatic cases, the corresponding figures at a cut-off limit of 3 mm were 90, 84, 12% and 0.003. CONCLUSIONS: TVS does not appear to be an effective screening method in asymptomatic postmenopausal Japanese women because of the low prevalence of endometrial disease in this population. We recommend a normal cut-off level for endometrial thickness of 4 mm in symptomatic postmenopausal Japanese women.