Impact of Registered Dietitian Expertise in Health Guidance for Weight Loss

Background & Objectives

Expertise of registered dietitians (RDs) is important for health guidance but has been poorly evaluated. We evaluated the kind of RD expertise that would improve their skills.

Design, Setting, Participants, Measurements

This study was a post-hoc analysis of our randomized controlled trial, which compared the weight change between participants using the web-based self-disclosure health support and those using the email health support. Healthy men and women aged 35–64 years with a body mass index (BMI) of > = 24.5 kg/m² were recruited for this study. We evaluated the relationship of RD expertise indicators including the duration of working as an RD, the experience of health counseling, and membership in the Japan Dietetic Association (JDA) with the weight loss of study participants. The primary endpoint was the change in body weight. Comparison of changes in body weight by the RD expertise indicators was evaluated using analysis of covariance.

Results

A total of 175 participants were eligible for analyses. Changes in body weight were significantly greater when they were supported by the RDs in the routine counseling group than when supported by the RDs in the non-routine counseling group (-1.8 kg versus -0.4 kg, fully adjusted P = 0.0089). Duration of working as an RD and JDA membership did not significantly affect changes in body weight.

Conclusions

Among some indices of RD experience, the experience of providing routine experience of health counseling was associated with weight loss.     

Fused heterocyclic amido compounds as anti-hepatitis C virus agents

We identified a fused heteroaromatic amido structure based on the phenanthridine skeleton as a superior scaffold for candidate drugs with potent anti-HCV activity. Among the compounds synthesized, a phenanthridine analogue with a 1,3-dioxolyl group (24) possessed the most potent anti-HCV activity (EC(50) value: 50 nM), with acceptable cytotoxicity. The structural development and structure-activity relationships of these compounds are described.     

Synthesis, structure, DNA binding and photocleavage activity of a ruthenium(II) complex with 11-(9-acridinyl)dipyrido[3,2-a:2′,3′-c]phenazine ligand

In our search for new DNA intercalating ligands, a novel bifunctional intercalator 11-(9-acridinyl)dipyrido[3,2-a:2′,3′-c]phenazine, acdppz (has two potentially effective intercalators via dipyridophenazine(dppz) and acridine which are linked together via C-C bond) and its corresponding Ru(II) polypyridyl complex [Ru(phen)₂(acdppz)]²⁺ (where phen = 1,10-phenanthroline) have been synthesized and characterized. The electrochemical behaviors of the ligand and its complex have been thoroughly examined. The structure of acdppz and [Ru(phen)₂(acdppz)]²⁺ were determined by X-ray crystallography. From the crystal structure of the complex, we found that the dppz moiety is not coplanar with the acridine ring, having a dihedral angle of 64.79 in the acdppz. The selected bond lengths and angles for the crystal structure of [Ru(phen)₂(acdppz)]²⁺ were compared to the geometry-optimized molecular structure of [Ru(phen)₂(acdppz)]²⁺ derived by Gaussian. The interaction of [Ru(phen)₂(acdppz)]²⁺ with calf-thymus (CT) DNA was investigated by absorption and viscometry titration, thermal denaturation studies. The above measurements indicated that the complex binds less strongly with the CT DNA due to the intercalation by the ruthenium bound acdppz with an intrinsic binding constant of 2.6 × 10⁵ M⁻¹. Molecular-modeling studies also support an intercalative mode of binding of the complex to the model duplex d(CGCAATTGCG)₂ possibly from the major groove with a slight preference for GC rich region. Additionally, the title complex promotes the cleavage of plasmid pBR322 DNA upon irradiation under aerobic conditions.     

Cell death and selective adhesion reorganize the dorsoventral boundary for zigzag patterning of Drosophila wing margin hairs

Animal tissues and organs are comprised of several types of cells, which are often arranged in a well-ordered pattern. The posterior part of the Drosophila wing margin is covered with a double row of long hairs, which are equally and alternately derived from the dorsal and ventral sides of the wing, exhibiting a zigzag pattern in the lateral view. How this geometrically regular pattern is formed has not been fully understood. In this study, we show that this zigzag pattern is created by rearrangement of wing margin cells along the dorsoventral boundary flanked by the double row of hair cells during metamorphosis. This cell rearrangement is induced by selective apoptosis of wing margin cells that are spatially separated from hair cells. As a result of apoptosis, the remaining wing margin cells are rearranged in a well-ordered manner, which shapes corrugated lateral sides of both dorsal and ventral edges to interlock them for zigzag patterning. We further show that the corrugated topology of the wing edges is achieved by cell-type specific expression and localization of four kinds of NEPH1/nephrin family proteins through heterophilic adhesion between wing margin cells and hair cells. Homophilic E-cadherin adhesion is also required for attachment of the corrugated dorsoventral edges. Taken together, our results demonstrate that sequential coordination of apoptosis and epithelial architecture with selective adhesion creates the zigzag hair alignment. This may be a common mechanism for geometrically ordered repetitive packing of several types of cells in similarly patterned developmental fields such as the mammalian organ of Corti.     

One-Dimensional Brownian Motion of Charged Nanoparticles along Microtubules: A Model System for Weak Binding Interactions

Various proteins are known to exhibit one-dimensional Brownian motion along charged rodlike polymers, such as microtubules (MTs), actin, and DNA. The electrostatic interaction between the proteins and the rodlike polymers appears to be crucial for one-dimensional Brownian motion, although the underlying mechanism has not been fully clarified. We examined the interactions of positively-charged nanoparticles composed of polyacrylamide gels with MTs. These hydrophilic nanoparticles bound to MTs and displayed one-dimensional Brownian motion in a charge-dependent manner, which indicates that nonspecific electrostatic interaction is sufficient for one-dimensional Brownian motion. The diffusion coefficient decreased exponentially with an increasing particle charge (with the exponent being 0.10 k_BT per charge), whereas the duration of the interaction increased exponentially (exponent of 0.22 k_BT per charge). These results can be explained semiquantitatively if one assumes that a particle repeats a cycle of binding to and movement along an MT until it finally dissociates from the MT. During the movement, a particle is still electrostatically constrained in the potential valley surrounding the MT. This entire process can be described by a three-state model analogous to the Michaelis-Menten scheme, in which the two parameters of the equilibrium constant between binding and movement, and the rate of dissociation from the MT, are derived as a function of the particle charge density. This study highlights the possibility that the weak binding interactions between proteins and rodlike polymers, e.g., MTs, are mediated by a similar, nonspecific charge-dependent mechanism.     

Purification and Characterization of a Ca2+-Dependent Protein Kinase from the Halotolerant Green Alga Dunaliella tertiolecta

A Ca²⁺-dependent protein kinase (CDPK) that has been partiallypurified and characterized previously [Yuasa and Muto (1992)Arch. Biochem. Biophys. 296: 175] was further purified to about20,000-fold from the soluble fraction of Dunaliella tertiolecta.The enzyme preparation contained 60- and 52-kDa polypeptidesboth of which phosphorylated casein as a substrate. Both polypeptidesshowed a Ca²⁺-dependent increase in mobility during SDS-PAGEand ⁴⁵Ca²⁺-binding activity after SDS-PAGE and electroblottingonto a nitrocellulose membrane, suggesting that both the 60-and 52-kDa CDPKs directly bind Ca²⁺. The protein kinase inhibitors,K-252a and staurosporine, inhibited the CDPK competitively withrespect to ATP. An antibody raised against the 60-kDa CDPK crossreactedwith both the 60- and 52-kDa polypeptides. Both molecular specieswere autophosphorylated in the presence of Ca²⁺, and a highlyphosphorylated 80-kDa band appeared in addition to these phosphorylatedbands at 60 and 52 kDa in SDS-PAGE. However, the specific activityof CDPK was not changed by prior autophosphorylation when theautophosphorylated enzyme was assayed as a mixture of thesephosphorylated molecular species. Only the 60-kDa polypeptidewas immunodetected in subcellular fractions of Dunaliella cells.The 52-kDa polypeptide increased during storage of the enzyme.These results suggest that the 52-kDa polypeptide is a proteolyticartifact produced during purification. Immunoreactive bandsof 60-kDa were detected in extracts of several green algae butnot in extracts of higher plants or a brown alga. ¹This research was partly supported by Grants-in-Aid from theMinistry of Education, Science and Culture, Japan (No. 06454013and 06304023) and Research Fellowship of the Japan Society forthe Promotion of Science for Young Sciencists. ²Research Fellow (PD) of the Japan Society for the Promotionof Science.     

Formation of a metallocycle by dimerization of acrylonitrile. Crystal structure of the hexakis{(1,4-dicyanobutane-1,4-diyl)-nickel(II)} complex

A novel hexanickel(II) complex [Ni₆(NCCHCH₂CH₂CHCN)₆] (2) with 1,4-dicyanobutane-1,4-diyl (L) which was produced by the metal-induced dimerization of acrylonitrile (AN) has been isolated and the structure has been determined crystallographically. Complex 2 is triclinic, space group

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. Each nickel atom is coordinated by two carbon atoms of L and two nitrogen atoms of the cyano group of two other L, providing a square-plenar geometry. The six nickel atoms are bridged by the cyano group and carbon atom to form the slightly distorted octahedral Ni₆ core.     

Correspondence of Apoproteins of Light-Harvesting Chlorophyll a/b Complexes Associated with Photosystem I to cab Genes: Evidence for a Novel Type IV Apoprotein

Apoproteins of spinach and pea light-harvesting chlorophylla/b complexes associated with photosystem I (LHCI) were identifiedby their chlorophyll fluorescence spectra and protein sequences.Spinach LHCI holocomplex consisted of four apoproteins of 25kDa, 23 kDa, 21 kDa and 20.5 kDa. LHCI subcomplex isolated bysucrose density gradient centrifugation fluoresced at 680 nmwith a shoulder around 700–710 nm at 77 K. It containedthe 23 kDa protein of which the N-terminal sequence correspondedto Type II gene of LHCI. Another LHCI subcomplex isolated bygel electrophoresis emitted at 679 nm and contained the 25 kDaprotein, of which the N-terminus was blocked. Its internal sequenceswere determined after protease treatment and found to be homologousto Type III gene of LHCI. An oligomeric subcomplex of LHCI isolatedby gel electrophoresis emitted at 726 nm and consisted of the21 kDa and 20.5 kDa apoproteins. N-terminal sequence of the20.5 kDa component corresponded to the Type I gene of LHCI.The 21 kDa component did not have any clear homologue, but itsN-terminal sequence was weakly but significantly homologousto all LHC components particularly to Type I LHCI among others.It was, thus, concluded that the 21 kDa protein is the fourthtype of LHCI apoprotein. Similar sequence homology was foundfor pea LHCI apoproteins. (Received September 10, 1990; Accepted November 22, 1990)