MACROSCOPIC OBSERVATIONS OF THE FACIAL MUSCLES IN THE BAIKAL SEAL (PHOCA SIBIRICA)

This study was performed to determine if, as expected, the enlarged eye of the Baikal seal ( Phoca sibirica ) has an influence on the form and function of the skull and facial muscles. Macroscopic observation of these muscles demonstrated that the M. orbicularis oculi expands around the palpebral fissure and that some facial muscles attach and insert in the M. orbicularis oculi , possibly supporting M. orbicularis oculi function. We suggest that these muscles move the eye and palpebral area and constitute a morphological and synergistic facial muscle complex system. Further, the development of the M. rectus lateralis around the sclera of the eye indicates that this muscle is also involved in eye movement.     

Types,rates, origin and expressivity of chromosome mutations involving 13q14 in retinoblastoma patients

Summary A cytogenetic survey of 200 retinoblastoma (Rb) patients revealed that approximately 8.5% of the fresh germinal mutations were microscopically detectable chromosome mutations, either interstitial deletions or rearrangements, involving 13q14. They showed a strong bias toward paternal origin, indicating a significant contribution of errors in paternal meiotic processes. The incidence of patients with Rb due to such chromosome mutations was estimated to be 1.9 x 10^-6 of live births. Age-specific incidence of Rb tumors suggested that the Rb mutations by such chromosomal mechanisms had a lower carcinogenic potential, as indicated by the later onset of disease, than other Rb mutations of germinal origin.     

Evidence that C4b-binding protein (proline-rich protein) is synthesized by hepatocytes

C4b-binding protein (C4bp), a glycoprotein involved in regulating the classical pathway of the complement system, binds the activated form of C4b and accelerates the decay rate of the C4b, C2a complex. Recently, sequence analysis of the cDNA for proline-rich protein (PRP) demonstrated that PRP is identical with C4bp. We measured the concentration of C4bp in serum by single radial immunodiffusion in patients with various liver diseases. Concentration of C4bp was significantly lower in hepatic cirrhosis (P = 0.001) and higher in fatty liver (P = 0.0002) than the control values, after adjusting for age, sex, and concentration of total cholesterol, triglyceride, and C-reactive protein. Significant positive correlations were observed between the concentration of C4bp in serum and total protein, albumin, cholinesterase level, and lecithin-cholesterol acyltransferase activity. Immunohistochemical analysis of human liver with specific antiserum to human C4bp demonstrated reaction endproducts in the hepatocytes around the central veins. These observations provide evidence that C4bp is synthesized by hepatocytes.     

Transformation of 25- and 1 alpha-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3 by using Streptomyces sp. strains.

To enzymatically synthesize vitamin D derivatives, we screened about 300 Streptomyces sp. strains. Streptomyces sclerotialus FERM BP-1370 and Streptomyces roseoporus FERM BP-1574 were found to have the ability to convert 25-hydroxyvitamin D3 and 1 alpha-hydroxyvitamin D3, respectively, to 1 alpha, 25-dihydroxyvitamin D3. The average rates of 1 alpha hydroxylation of 25-hydroxyvitamin D3 were 6.9 micrograms liter-1 min-1 with FERM BP-1370 and 7.0 micrograms liter-1 min-1 with FERM BP-1574. The specific cytochrome P-450 inhibitors carbon monoxide, SKF-525-A, and metyrapone inhibited the hydroxylation of 1 alpha- and 25-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3 by FERM BP-1370 and FERM BP-1574. The cytochromes P-450 of these strains were detected by reduced CO difference spectra in the whole-cell suspensions. The appearance of cytochrome P-450 suggests that the cytochromes P-450 of FERM BP-1370 and FERM BP-1574 carry out the hydroxylation of 25- and 1 alpha-hydroxyvitamin D3 to 1 alpha, 25-dihydroxyvitamin D3.     

Assembly and maintenance of nodes of ranvier rely on distinct sources of proteins and targeting mechanisms

We have investigated the source(s) and targeting of components to PNS nodes of Ranvier. We show adhesion molecules are freely diffusible within the axon membrane and accumulate at forming nodes from local sources, whereas ion channels and cytoskeletal components are largely immobile and require transport to the node. We further characterize targeting of NF186, an adhesion molecule that pioneers node formation. NF186 redistributes to nascent nodes from a mobile, surface pool. Its initial accumulation and clearance from the internode require extracellular interactions, whereas targeting to mature nodes, i.e., those flanked by paranodal junctions, requires intracellular interactions. After incorporation into the node, NF186 is immobile, stable, and promotes node integrity. Thus, nodes assemble from two sources: adhesion molecules, which initiate assembly, accumulate by diffusion trapping via interactions with Schwann cells, whereas ion channels and cytoskeletal components accumulate via subsequent transport. In mature nodes, components turnover slowly and are replenished via transport. VIDEO ABSTRACT:     

Potentiation of brain acetylcholine neurons by Kami-Untan-To (KUT) in aged mice: implications for a possible antidementia drug.

The effects of a traditional Japanese herbal medicine, Kami-Untan-To (KUT), on brain choline (Ch) and Acetylcholine (ACh) levels in aged mice were examined. Further, the expression of choline acetyltransferase (ChAT) in the medial septum (MS), the vertical limbs of the diagonal band of Broca (VDB), and the nucleus basalis Meynert (NBM) was examined by immunohistochemistry. Following an oral administration of KUT to the aged mice for 3 months, ACh levels in the cortex, striatum and hippocampus were increased significantly. The density of ChAT-immunoreactive cells located in MS, VDB, and NBM in the KUT-treated group was increased significantly as compared to the non-treatment group. The survival rate of aged mice was significantly higher in the KUT-treated group as compared to that in the nontreated group. Our results suggest that KUT potentiates the brain acetylcholinergic system, and may become a possible anti-dementia drug.