bluuebunny/crossref_metadata_2025_split huggingface dataset:
Androgens and Bone
Authors: Vanderschueren Dirk , Vandenput Liesbeth , Boonen Steven , Lindberg Marie K. , Bouillon Roger , Ohlsson Claes 
Published: June 2004

Loss of estrogens or androgens increases the rate of bone remodeling by removing restraining effects on osteoblastogenesis and osteoclastogenesis, and also causes a focal imbalance between resorption and formation by prolonging the lifespan of osteoclasts and shortening the lifespan of osteoblasts. Conversely, androgens, as well as estrogens, maintain cancellous bone mass and integrity, regardless of age or sex. Although androgens, via the androgen receptor (AR), and estrogens, via the estrogen receptors (ERs), can exert these effects, their relative contribution remains uncertain. Recent studies suggest that androgen action on cancellous bone depends on (local) aromatization of androgens into estrogens. However, at least in rodents, androgen action on cancellous bone can be directly mediated via AR activation, even in the absence of ERs.Androgens also increase cortical bone size via stimulation of both longitudinal and radial growth. First, androgens, like estrogens, have a biphasic effect on endochondral bone formation: at the start of puberty, sex steroids stimulate endochondral bone formation, whereas they induce epiphyseal closure at the end of puberty. Androgen action on the growth plate is, however, clearly mediated via aromatization in estrogens and interaction with ERα. Androgens increase radial growth, whereas estrogens decrease periosteal bone formation. This effect of androgens may be important because bone strength in males seems to be determined by relatively higher periosteal bone formation and, therefore, greater bone dimensions, relative to muscle mass at older age. Experiments in mice again suggest that both the AR and ERα pathways are involved in androgen action on radial bone growth. ERβ may mediate growth-limiting effects of estrogens in the female but does not seem to be involved in the regulation of bone size in males.In conclusion, androgens may protect men against osteoporosis via maintenance of cancellous bone mass and expansion of cortical bone. Such androgen action on bone is mediated by the AR and ERα.
Central Fat Mass Versus Peripheral Fat and Lean Mass: Opposite (Adverse Versus Favorable) Associations with Arterial Stiffness? The Amsterdam Growth and Health Longitudinal Study
Authors: Ferreira Isabel , Snijder Marieke B. , Twisk Jos W. R. , van Mechelen Willem , Kemper Han C. G. , Seidell Jacob C. , Stehouwer Coen D. A. 
Published: June 2004

Abstract
Central and peripheral fatness seem to confer opposite (i.e. adverse vs. protective) effects on cardiovascular risk, but how this occurs is not clear. In addition, the role of peripheral lean mass needs to be elucidated. We therefore investigated, in 336 (175 women) 36-yr-old and apparently healthy adults, the relationship between trunk fat, peripheral fat, and peripheral lean mass on the one hand, and estimates of stiffness of three large arteries on the other. Body composition was assessed by dual-energy x-ray absorptiometry. Arterial properties were assessed by ultrasound imaging. We found that 1) trunk fat was positively (i.e. adversely) associated with stiffness of the carotid and femoral arteries, whereas peripheral fat was inversely (i.e. favorably) associated with stiffness of the brachial and the carotido-femoral segment; 2) peripheral lean mass was positively associated with arterial diameter and carotid compliance and inversely associated with stiffness of the carotido-femoral segment; and 3) after adjustment for the other body composition variables, the above-mentioned associations remained, but peripheral fat in addition became, if anything, favorably associated with stiffness of the femoral artery. We conclude that trunk fat is adversely associated with large artery stiffness, whereas some degree of protection is conferred by peripheral fat and lean mass.
Neonatal Diabetes Mellitus and Neonatal Polycystic, Dysplastic Kidneys: Phenotypically Discordant Recurrence of a Mutation in the Hepatocyte Nuclear Factor-1β Gene Due to Germline Mosaicism
Authors: Yorifuji Tohru , Kurokawa Keiji , Mamada Mitsukazu , Imai Tsuyoshi , Kawai Masahiko , Nishi Yoshikazu , Shishido Seiichiro , Hasegawa Yukihiro , Nakahata Tatsutoshi 
Published: June 2004

AbstractMutations in the gene coding for hepatocyte nuclear factor-1β (HNF-1β) have been known to cause a form of maturity-onset diabetes of the young (MODY5), which is usually characterized by dominantly inherited adolescence-onset diabetes mellitus associated with renal cysts. This report, however, describes recurrence of a novel missense mutation in the HNF-1β gene, S148W (C443G), in two sibs, one with neonatal diabetes mellitus and the other with neonatal polycystic, dysplastic kidneys leading to early renal failure. The former patient had only a few small renal cysts with normal renal functions, and the latter had only a transient episode of hyperglycemia, which resolved spontaneously. Interestingly, both parents were clinically unaffected, and PCR restriction fragment length polymorphism analysis showed that the mother was a low-level mosaic of normal and mutant HNF-1β, which suggested that the recurrence was caused by germline mosaicism. This is the first report of permanent neonatal diabetes mellitus caused by a mutation of the HNF-1β gene as well as the first report of germline mosaicism of this gene. In addition, the two cases described here show that additional factors, genetic or environmental, can have a significant influence on the phenotypic expression of HNF-1β mutations.
Serum Haptoglobin: A Novel Marker of Adiposity in Humans
Authors: Chiellini C. , Santini F. , Marsili A. , Berti P. , Bertacca A. , Pelosini C. , Scartabelli G. , Pardini E. , López-Soriano J. , Centoni R. , Ciccarone A. M. , Benzi L. , Vitti P. , Del Prato S. , Pinchera A. , Maffei M. 
Published: June 2004

AbstractHaptoglobin (Hp) is a glycoprotein involved in the acute phase response to inflammation. Our previous findings indicate that Hp mRNA and protein are present in the adipose tissue of rodents and that Hp gene expression is up-regulated in obese models. The aim of the present study was to establish whether Hp could be considered a marker of obesity in humans. In 312 subjects, serum Hp was correlated directly with body mass index (BMI), leptin, C-reactive protein (CRP), and age. In a multivariate stepwise regression analysis, BMI and CRP were independent determinants of serum Hp in females, with BMI having the strongest effect. CRP and age were independent determinants of serum Hp in males, although explaining only a modest percentage of the total variability. Serum Hp was positively associated with body fat, as assessed by dual-energy x-ray absorptiometry, both in female and in male groups. The level of significance improved when serum Hp was analyzed against fat mass adjusted for lean mass. Finally, Northern and Western blot analyses performed in biopsies of sc abdominal fat from 20 obese individuals showed the presence of Hp mRNA and protein in the human adipose tissue.In conclusion, serum Hp constitutes a novel marker of adiposity in humans, and the adipose tissue likely contributes to determine its levels.
Race/Ethnic Issues in Obesity and Obesity-Related Comorbidities
Authors: Cossrow Nicole , Falkner Bonita 
Published: June 2004

AbstractThe prevalence of obesity is increasing among all age and racial groups in the United States. There is, however, a disproportionate rise in the prevalence of obesity among African-Americans and Hispanic/Mexican Americans. Obesity is a major contributor to the insulin resistant syndrome (IRS), a condition of multiple metabolic abnormalities that is a precursor to type 2 diabetes, and confers a high risk for cardiovascular events. The estimated prevalence of IRS is also greater in Mexican Americans and African-Americans than in Caucasians. The IRS is identifiable in children, and as with adults, there are racial differences in its expression even at a young age. The obesity-associated diseases, including diabetes and hypertension, are found at higher rates within the minority races compared with Caucasians. However, there are differences, in that obesity-related hypertension occurs at higher rates among African-Americans, and obesity-related diabetes occurs at higher rates among Mexican Americans. Race/ethnic differences in lifestyle behaviors and economic disadvantage may account for some of the race disparity in obesity-related diseases and disease outcomes. Environmental factors, however, do not explain all of the race disparity in disease expression, indicating that there are genetic/molecular factors that are operational as well.
Proopiomelanocortin and Energy Balance: Insights from Human and Murine Genetics
Authors: Coll Anthony P. , Farooqi I. Sadaf , Challis Benjamin G. , Yeo Giles S. H. , O’Rahilly Stephen 
Published: June 2004

Abstract
Proopiomelanocortin (POMC) undergoes extensive and tissuespecific posttranslational processing to yield a range of biologically active peptides. Historically, the most clearly defined roles of these peptides are in the control of adrenal steroidogenesis by corticotroph-derived ACTH and skin pigmentation by αMSH. However, a rapidly expanding body of work has established that POMC-derived peptides synthesized in neurons of the hypothalamus play a central role in the control of energy homeostasis. We review how inherited abnormalities in POMC synthesis and processing and defects in the action of POMC-derived peptides in both humans and mice have helped shape our current understanding of the importance of the melanocortin system in human energy balance.
Abdominal Obesity and Dyslipidemia in the Metabolic Syndrome: Importance of Type 2 Diabetes and Familial Combined Hyperlipidemia in Coronary Artery Disease Risk
Authors: Carr Molly C. , Brunzell John D. 
Published: June 2004

AbstractRegional body fat distribution has an important influence on metabolic and cardiovascular risk factors. Increased abdominal (visceral) fat accumulation is a risk factor for coronary artery disease (CAD), dyslipidemia, hypertension, stroke, and type 2 diabetes. The recent emphasis on treatment of the dyslipidemia of the metabolic syndrome (hypertriglyceridemia, reduced high-density lipoprotein, and increased small, dense low-density lipoprotein particle number) has compelled practitioners to consider lipid-lowering therapy in a greater number of their patients, as one in two individuals over age 50 has the metabolic syndrome. Individuals with the metabolic syndrome typically have normal low-density lipoprotein cholesterol levels, and current lipid-lowering guidelines may underestimate their cardiovascular risk. Two subgroups of patients with the metabolic syndrome are at particularly high risk for premature CAD. One, individuals with type 2 diabetes, accounts for 20–30% of early cardiovascular disease. The second, familial combined hyperlipidemia, accounts for an additional 10–20% of premature CAD. Familial combined hyperlipidemia is characterized by the metabolic syndrome in addition to a disproportionate elevation of apolipoprotein B levels. The measurement of fasting glucose and apolipoprotein B, in addition to the fasting lipid profile, can help to estimate CAD risk in patients with the metabolic syndrome.
Pineal organs of deep-sea fish: photopigments and structure
Authors: Bowmaker James K. , Wagner Hans-Joachim 
Published: June 2004

SUMMARYWe have examined the morphology and photopigments of the pineal organs from a number of mesopelagic fish, including representatives of the hatchet fish(Sternoptychidae), scaly dragon-fish (Chauliodontidae) and bristlemouths(Gonostomidae). Although these fish were caught at depths of between 500 and 1000 m, the morphological organisation of their pineal organs is remarkably similar to that of surface-dwelling fish. Photoreceptor inner and outer segments protrude into the lumen of the pineal vesicle, and the outer segment is composed of a stack of up to 20 curved disks that form a cap-like cover over the inner segment. In all species, the pineal photopigment was spectrally distinct from the retinal rod pigment, with λmax displaced to longer wavelengths, between ∼485 and 503 nm. We also investigated the pineal organ of the deep demersal eel, Synaphobranchus kaupi, caught at depths below 2000 m, which possesses a rod visual pigment withλ max at 478 nm, but the pineal pigment hasλ max at ∼515 nm. In one species of hatchet fish, Argyropelecus affinis, two spectral classes of pinealocyte were identified, both spectrally distinct from the retinal rod photopigment.
Colour vision in the glow-worm Lampyris noctiluca (L.)(Coleoptera: Lampyridae): evidence for a green-blue chromatic mechanism
Authors: Booth David , Stewart Alan J. A. , Osorio Daniel 
Published: June 2004

SUMMARY
Male glow-worms Lampyris noctiluca find their bioluminescent mates at night by phototaxis. There is good evidence that location of mates by lampyrid beetles is achieved by a single spectral class of photoreceptor,whose spectral sensitivity is tuned to the bioluminescent spectrum emitted by conspecifics, and is achromatic. We ask whether glow-worm phototaxis involves interactions between two spectral classes of photoreceptor. Binary choice experiments were conducted in which males were presented with artificial light stimuli that differ in spectral composition. The normal preference for a green stimulus (λmax=555 nm), corresponding to the bioluminescence wavelength produced by signalling females, was significantly reduced by adding a blue (λmax=485 nm) component to the signal. This implies an antagonistic interaction between long- and short-wavelength sensitive photoreceptors, suggesting colour vision based on chromatic opponency. Cryosections showed a band of yellow filter pigment in the fronto-dorsal region of the male compound eye, which could severely constrain colour vision in the dim conditions in which the insects signal. This apparent paradox is discussed in the context of the distribution of the pigment within the eye and the photic niche of the species.
Dopamine stimulates snail albumen gland glycoprotein secretion through the activation of a D1-like receptor
Authors: Mukai S. T. , Kiehn L. , Saleuddin A. S. M. 
Published: June 2004

SUMMARYThe catecholamine dopamine is present in both the central nervous system and in the peripheral tissues of molluscs, where it is involved in regulating reproduction. Application of exogenous dopamine to the isolated albumen gland of the freshwater pulmonate snail Helisoma duryi (Wetherby) induces the secretion (release) of perivitelline fluid. The major protein component of the perivitelline fluid of Helisoma duryi is a native 288 kDa glycoprotein that is secreted around individual eggs and serves as an important source of nutrients for the developing embryos. The secretion of glycoprotein by the albumen gland is a highly regulated event that must be coordinated with the arrival of the fertilized ovum at the carrefour (the region where the eggs receive albumen gland secretory products). In order to elucidate the intracellular signalling pathway(s) mediating dopamine-induced glycoprotein secretion, albumen gland cAMP production and glycoprotein secretion were measured in the presence/absence of selected dopamine receptor agonists and antagonists. Dopamine D1-selective agonists dihydrexidine,6,7-ADTN and SKF81297 stimulated cAMP production and glycoprotein secretion from isolated albumen glands whereas D1-selective antagonists SCH23390 and SKF83566 suppressed dopamine-stimulated cAMP production. Dopamine D2-selective agonists and antagonists generally had no effect on cAMP production or protein secretion. Based on the effects of these compounds, a pharmacological profile was obtained that strongly suggests the presence of a dopamine D1-like receptor in the albumen gland of Helisoma duryi. In addition,secretion of albumen gland glycoprotein was not inhibited by protein kinase A inhibitors, suggesting that dopamine-stimulated protein secretion might occur through a protein kinase A-independent pathway.
Total Synthesis of Bistratamide G, a Metabolite of the Philippines Ascidian Lissoclinum bistratum, from Dehydrotripeptides
Authors: Shin Chung-gi , Abe Chieko , Yonezawa Yasuchika 
Published: June 2004

Abstract
Total synthesis of triheterocyclic cyclopeptide bistratamide G, a metabolite from the Philippines ascidian Lissoclinum bistratum, was first achieved from two kinds of dehydrotripeptides.
Preparation and Characterization of Tungsten-substituted Molybdenum Disulfide Nanorods
Authors: Xia Junbao , Xu Zhude , Chen Weixiang , Nie Qiulin , Li Guohua 
Published: June 2004

Abstract
The tungsten-substituted molybdenum disulfide nanorods were synthesized through a pyrolysis process. The rod-shaped trisulfide precursor was prepared using a reversed micelle based method. The tungsten-substituted molybdenum disulfide nanorods were obtained by thermal decomposition of the as-prepared precursor. Energy dispersive spectroscopy identified that the chemical composition of the final product was Mo0.95W0.05S2. The produced nanorods were further characterized with X-ray power diffraction and transmission electron microscopy.
Spontaneous Assembly Formation of Cyclic Dimer of β-Amino Acid in Water
Authors: Fujimura Futoshi , Fukuda Makoto , Sugiyama Junji , Morita Tomoyuki , Kimura Shunsaku 
Published: June 2004

Abstract
A novel cyclic dimer composed of chiral l-β-homoalanine was synthesized, and the formation of molecular assembly in water was investigated. The cyclic dimer was found to spontaneously form a spherical assembly with diameter of 40–100 nm in water. The cyclic dimer takes a boat conformation with cis-amide configuration, and forms intermolecular hydrogen bondings in the assembly. The assembling property of the cyclic dimer of β-amino acid is distinct from that of α-amino acid.
Useful Synthesis of Fragment A–C–D of a Thiostrepton-type Macrocyclic Antibiotic, Thiocilline I
Authors: Suzuki Shuusuke , Yonezawa Yasuchika , Shin Chung-gi 
Published: June 2004

Abstract
Useful synthesis of the main Fragment A–C–D segment constructing a thiostrepton-type macrocyclic antibiotic, thiocilline I, was first achieved by coupling of the 2,3,6-polythiazolesubstituted pyridine skeleton (Fragment A–C) with Fragment D.
A New Route to Control Product Selectivity in the Oxidative Dehydrogenation of Cyclohexane and Cyclohexene
Authors: Zhu Yujun , Li Jing , Yang Xiangguang , Wu Yue 
Published: June 2004

Abstract
The product selectivity can be controlled by adding acetic acid in feed over vanadium phosphate (VPO) in gas phase oxidative dehydrogenation (ODH), in which cyclohexane and cyclohexene are oxidized to cyclohexene and 1,3-cyclohexadiene (1,3-CHD), respectively, at almost 100% selectivity. This approach is also an efficient method to capture the very unstable intermediates in the mechanism study.
Cobalt Ferrite Nanoparticles Prepared by Coprecipitation/Mechanochemical Treatment
Authors: Yang Huaming , Zhang Xiangchao , Tang Aidong , Qiu Guanzhou 
Published: June 2004

Abstract
Cobalt ferrite (CoFe2O4) nanoparticles have been prepared by chemical coprecipitation, mechanical milling and subsequent thermal treatment. Sodium chloride was added as a diluent during mechanical milling to avoid agglomeration of the particles. Thermal treatment of the as-milled powder at 600 °C produces well-crystallized CoFe2O4 nanoparticles with an average crystal size of 22.5 nm. The mechanism of nanoparticle growth was discussed.
Periodic Pulse Electrodeposition to Synthesize Ultra-high Density CdS Nanowire Arrays Templated by SBA-15 Mesoporous Films
Authors: Gu Jinlou , Shi Jianlin , Chen Hangrong , Xiong Liangming , Shen Weihua , Ruan Meilin 
Published: June 2004

Abstract
The high-density CdS nanowire arrays, which are the negative replica of the parent mesoporous thin films with a stoichiometric composition, have been synthesized through a newly developed periodic pulse electrodeposition route.
Cobalt-Catalyzed Allylic Substitution Reaction of Allylic Ethers with Phenyl and Trimethylsilylmethyl Grignard Reagents
Authors: Mizutani Keiya , Yorimitsu Hideki , Oshima Koichiro 
Published: June 2004

Abstract
Treatment of cinnamyl methyl ether with phenylmagnesium bromide in ether in the presence of CoCl2[1,5-bis(diphenylphosphino)pentane] affords 1,3-diphenylpropene in good yield. Similar allylic substitution reaction with trimethylsilylmethylmagnesium chloride proceeded smoothly to yield homoallylsilanes. α,β-Unsaturated aldehyde acetal also underwent allylic substitution.
Facile Oxidation of Aldehydes to Esters Using S·SnO2/SBA-1–H2O2
Authors: Qian Guang , Zhao Rui , Ji Dong , Lu Gaomeng , Qi Yanxing , Suo Jishuan 
Published: June 2004

Abstract
A highly efficient, mild, and simple procedure has been described for the oxidation of aldehydes to corresponding esters in alcohols with S·SnO2/SBA-1 as catalyst and H2O2 as the oxidant, and the catalytic systems can be used in the preparation of a broad range of esters. Oxidation of aldehydes to corresponding esters utilizing H2O2 as the oxidant without any metal catalyst is also reported.
Synthesis of Artificial Opals with Uniform Mesoporous Silica Spheres
Authors: Chen Chau-Nan , Lin Hong-Ping , Tsai Chih-Pin , Tang Chin-Yuan 
Published: June 2004

Abstract
The mesoporous silica submicron-spheres (80–200 nm) with a small dispersion in diameter (&lt; 10%) as the building blocks of the artificial mesoporous silica opals have been synthesized using quaternary ammonium surfactant as template in an aqueous solution of suitable polarity at near neutral condition of pH = 7.0–9.0.
Preparation of Water-soluble PEGylated Semiconductor Nanocrystals
Authors: Kang Eui-Chul , Ogura Atsuhiko , Kataoka Kazunori , Nagasaki Yukio 
Published: June 2004

Abstract
We describe the synthesis of water-soluble PEGylated semiconductor nanocrystals and the characterization of their optical properties and colloidal stability by fluorescence and UV spectrometers. The fluorescence intensity of PEGylated CdSe/ZnS in PBS buffer was observed to be 75% of the initial values of conventional CdSe/ZnS in chloroform. The PEGylated CdSe/ZnS exhibited higher fluorescence intensity than PEGylated CdSe and CdSe/CdS in PBS buffer. The colloidal stability of PEGylated QDs in PBS buffer was estimated by transmittance as a function of time at 37 °C. The PEGylated CdSe/ZnS showed a colloidal stable dispersion in PBS buffer during 24 h.
Reversible Optical Rotation Change According to the Enantiospecific Photochromic Reaction of [2.2]Metacyclophan-1-ene
Authors: Takeshita Michinori , Yamato Takehiko 
Published: June 2004

Abstract
Chiral [2.2]metacyclophan-1-ene undergoes an enantiospecific photochromic reaction along with a photoreversible optical rotation change at the wavelength where both photoisomers never absorb. This enables us to carry out a non-destructive read-out of the photomemory made by the photochromic [2.2]metacyclophan-1-ene.
Novel Photochromic Behavior of Benzoylhemithioindigo Based on Photodimerization
Authors: Tanaka Kiyoshi , Taguchi Kazuto , Iwata Satoru , Irie Takayuki 
Published: June 2004

Abstract
Benzoyl-substituted hemithioindigo 1 has a novel type of photochromic behavior based on the formation of the photoinduced [2+4] cycloadduct; that is, irradiation of 1 produces the cycloadduct 2 with all trans-configurations between the adjacent carbonyl moieties; this is completely dissociated back to 1 on heating.