bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of parathyroid hormone (hPTH[1-34]) infusion on serum 1,25-dihydroxyvitamin D and parathyroid hormone in normal women
Authors: Kinyamu H. Karimi , Gallagher J. Christopher , Petranick Kimberly M. , Ryschon Kay L.
Published: February 2010

Calcium absorption declines with age. Because 1,25-dihydroxyvitamin D (1,25(OH)2D) is the major hormone controlling calcium absorption, changes in vitamin D metabolism may account for the malabsorption of aging. Serum levels of 1,25(OH)2D have been reported to either decrease or remain unchanged with age. To assess the effect of aging on renal production of 1,25(OH)2D, we evaluated the response of renal 25OHD 1α hydroxylase to human parathyroid hormone (hPTH(1-34) stimulation in 119 women ages 25-83 years. In this population, baseline serum 25OHD and 1,25(OH)2D values did not significantly change with age, but serum iPTH (r = 0.44; p < 0.001) and serum creatinine (r = 0.31; p < 0.01) increased with age. However, the stimulatory activity of hPTH(1-34) on the renal production of 1,25(OH)2D declined with age (r3 = -0.36; p < 0.001) and was most apparent after age 75, being 50% less than that of younger women. Besides age, the production of 1,25(OH)2D was found to be dependent on baseline serum iPTH (r = -0.31; p < 0.0001). Administration of hPTH(1-34) led to suppression of endogenous PTH, and suppressibility of endogenous PTH declined with age (r = 0.53; p < 0.0001). The increase in serum PTH and decreased suppressibility of PTH with age could be due to mild secondary hyperparathyroidism. The increase in PTH with age is probably responsible for maintaining normal serum 1,25(OH)2D levels in elderly subjects; however, decreased metabolism of 1,25(OH)2D in the elderly could also maintain normal serum 1,25(OH)2D levels.
Evaluation of signal transduction mechanisms for the mitogenic effects of prostaglandin E2 in normal human bone cells in vitro
Authors: Baylink Timothy M. , Mohan Subburaman , Fitzsimmons Robert J. , Baylink David J.
Published: February 2010

Prostaglandin E2 (PGE2) is one of the most potent stimulators of bone formation in vivo. In these studies, we investigated the mechanism(s) underlying PGE2 effects on human bone formation by evaluating the effects of PGE2 on normal human bone cell (HBC) proliferation in vitro. Cell proliferation of normal HBCs was increased by PGE2 as measured by increased [3H]thymidine incorporation after 18 h and increased cell number after 48 h of treatment. The effect of PGE2 to stimulate cell proliferation was biphasic, with a maximum stimulation between 0.01 and 1.0 nM PGE2 in different experiments. At higher concentrations of PGE2 (0.1 μM), HBC proliferation was inhibited. Signal transduction for PGE2 has been reported to include both protein kinase A (PKA) and protein kinase C (PKC) pathways. In these studies, concentrations of PGE2 which stimulated cell proliferation did not increase cyclic adenosine monophosphate (cAMP) production. However, higher concentrations of PGE2 increased cAMP production (7- to 12-fold at 1-10 μM) and inhibited cell proliferation. Because stimulators of PKC, such as phorbol esters, have been reported to stimulate cell proliferation, the action of PKC inhibitors were tested. Both staurosporine and sangivamysin (PKC inhibitors) totally abrogated the effect of PGE2 to stimulate cell proliferation. Additional studies revealed that PGE2 increased 45Ca uptake in a dose-dependent manner with a peak response occuring between 1 and 10 nM PGE2 concentrations in different experiments. Furthermore, when the calcium channel blocker, verapamil, was added to HBC cultures treated with PGE2, the stimulation of 45Ca uptake and cell proliferation by PGE2 was completely blocked. These data suggest that PGE2 increases cell proliferation through activation of a verapamil-sensitive calcium channel. In conclusion, these data are consistent with a model in which stimulation of HBC proliferation by low doses of PGE2 is mediated by an enhancement of phospholipase C, which results in both an increase in PKC activity and an increase in intracellular calcium influx.
Possible involvement of RGD (arg-gly-asp)-containing extracellular matrix proteins in rat growth plate chondrocyte differentiation in culture
Authors: Yasuda Tadashi , Shimizu Katsuji , Nakagawa Yasuaki , Ishikawa Hiroshi , Nishihara Hideki , Nakamura Takashi
Published: February 2010

RGD (arg-gly-asp)-containing proteins have been shown to be components of cartilage matrix. In the present study, the role of interactions of cells with RGD-containing cartilage matrix proteins in rat costal epiphyseal chondrocyte differentiation was examined using a pelleted culture system as an in vitro model of endochondral ossification. Cell attachment assays showed the presence of integrins which mediated the binding of chondrocytes to fibronectin, a member of RGD-containing cartilage matrix proteins, in an RGD-dependent manner. In the early culture period, when chondrocytes had nonhypertrophic morphology with low levels of alkaline phosphatase, the exogenous addition of synthetic peptide GRGDSP (gly-arg-gly-asp-ser-pro) caused an increase in alkaline phosphatase levels and enlargement of chondrocytes in pelleted cultures. Treatment with GRGDSP from the early to late culture periods in association with the transition of chondrocytes from prehypertrophic to hypertrophic phenotypes followed by matrix mineralization resulted in suppression of mineral growth without significant effects on alkaline phosphatase levels or cellular morphology in the cultures. Similarly, addition of the synthetic peptide during the late culture period with the advance of cartilage mineralization suppressed mineral growth in pelleted cultures. These data indicate an important role of interactions of chondrocytes with RGD-containing cartilage matrix proteins through integrins in the regulation of epiphyseal chondrocyte differentiation in pelleted cultures.
Tartrate-resistant acid phosphatase from human bone: Purification and development of an immunoassay
Authors: Halleen Jussi , Hentunen Teuvo A. , Hellman Jukka , Väänlänen H. Kalervo
Published: February 2010

Tartrate-resistant acid phosphatase (TRAP) was purified 20,000-fold to apparent homogeneity from human bone. The purified enzyme consisted of one 32 kd subunit, which was cleaved by β-mercaptoethanol into two subunits of 15 kd and 20 kd, as shown by sodium dodecyl sulfide-polyacrylamide gel electrophoresis (SDS-PAGE) and silver staining. The purified enzyme was identified by N-terminal amino acid sequencing, and it was shown to be homologous with previously purified TRAPs from other sources. We developed a polyclonal antiserum against the purified enzyme in mice. In immunohistochemistry, the antiserum recognized osteoclasts from human bone and alveolar macrophages from human lung tissue, but no cells from human spleen tissue. It also stained osteoclasts from rat bone cells cultured on bovine bone slices. Purified TRAP could be inhibited by vanadate and molybdate, but not by tartrate, and it was activated 2-fold by β-mercaptoethanol. The glycoprotein structure of human bone TRAP was analyzed, and it was shown to contain only high-mannose type carbohydrates. We used the polyclonal antibody to develop a competitive fluorescence immunoassay for measuring serum TRAP concentrations. According to the assay, children have higher serum TRAP concentrations than adults, and postmenopausal women have higher concentrations than premenopausal women. Postmenopausal women also have higher serum TRAP concentrations than postmenopausal women on estrogen replacement therapy.
Evidence for an interaction between calcium intake and physical activity on changes in bone mineral density
Authors: Specker Bonny L.
Published: February 2010

Results of trials on the effects of physical activity on bone mineral density (BMD) are conflicting. The current hypothesis was that calcium intake modifies the bone response to physical activity. Published trials on physical activity and bone density were reviewed, and the results of 17 trials are summarized. Physical activity has beneficial effects on BMD at high calcium intakes, with no effect at mean calcium intakes less than a mean of 1000 mg/day. The modifying effect of calcium intake on BMD among exercise groups is more pronounced in the lumbar spine than in the radius. This analysis may explain conflicting results of trials on physical activity and calcium effects on bone. Controlled trials designed to test adequately this hypothesis are needed.
Purification and characterization of fully functional human osteoclast precursors
Authors: James Ian E. , Dodds Robert A. , Lee-Rykaczewski Elizabeth , Eichman Christopher F. , Connor Janice R. , Hart Timothy K. , Maleeff Beverly E. , Lackman Richard D. , Gowen Maxine
Published: February 2010

The identification and purification of human osteoclast precursors is essential to further our understanding of the mechanisms that control human osteoclast differentiation. Osteoclastoma tissue potentially provides a rich source of human osteoclast precursors, and in previous studies we have demonstrated the existence of a population of mononuclear cells within this tissue that is reactive with osteoclast-selective vitronectin receptor monoclonal antibodies. In this study, mononuclear cells expressing the vitronectin receptor, as defined by their ability to react with a murine monoclonal antibody to the β3 chain of the vitronectin receptor (87MEM1), were isolated from collagenase digests of osteoclastoma tissue using a fluorescence activated cell sorter. Based on their fluorescence signal and size, approximately 2–3% of the viable cells (typically 2 × 105) were obtained and prepared for further phenotyping. The isolated cells demonstrated a number of phenotypic characteristics of osteoclasts: positive tartrate-resistant acid phosphatase (TRAP) activity, reactivity with human osteoclast-selective antibodies, expression of calcitonin receptors, cathepsin K (a novel osteoclast-selective cysteine proteinase) mRNA, and osteopontin mRNA and protein. These phenotypic characteristics were also detected in mononuclear cells within cryostat sections of the native osteoclastoma tissue as well as in resorption lacunae of sections of human bone. In contrast, isolated peripheral blood monocytes were negative for TRAP activity and osteopontin expression and, unlike the osteoclastoma-derived cells, demonstrated strong nonspecific esterase activity. Significantly, when the osteoclastoma-derived 87MEM1 positive cells were cocultured on whale dentine for 1–3 weeks with stromal cells, extensive resorption of the dentine surface was observed. This is the first demonstration of the purification of human osteoclast precursors. These cells provide an homogeneous cell population for studying cellular events that occur during human osteoclast differentiation. (J Bone Miner Res 1996;11:1608-1618)
Leukotriene B4 stimulates osteoclastic bone resorption both in vitro and in vivo
Authors: Garcia Carlos , Boyce Brendan F. , Gilles James , Dallas Mark , Qiao Mei , Mundy Gregory R. , Bonewald Lynda F.
Published: February 2010

Upon activation, the enzyme 5‐lipoxygenase converts arachidonic acid into principally three products, the peptido‐leukotrienes, 5‐hydroperoxyeicosatetraenoic acid (5‐HETE) or the leukotriene B4. We have shown that the peptido‐leukotrienes (known as LTC4, LTD4, or LTE4) and 5‐HETE induce osteoclastic bone resorption and that receptors for LTD4 are present on isolated avian osteoclast‐like cells. Here, we show the effects of the third metabolic product of the 5‐lipoxygenase (5‐LO) pathway of arachidonic acid metabolism, the leukotriene LTB4, on osteoclastic bone resorption both in vivo and in vitro. Because LTB4 production is increased in a number of inflammatory conditions, it may be an important contributor to the bone loss which occurs in these disorders. LTB4 increased osteoclastic bone resorption in vivo following local administration over the calvariae of normal mice and in vitro in organ cultures of neonatal mouse calvariae. When LTB4 was injected over the calvaria of mice, there was a significant increase in bone resorption, osteoclast numbers, and eroded surfaces. LTB4 also increased the formation of resorption lacunae by isolated neonatal rat osteoclasts. Greater potency was observed with LTB4 compared with the peptido‐leukotriene LTD4. This is in contrast to prostaglandins of the E series, which are reported to inhibit isolated osteoclasts. Experiments using marrow cultures suggest that LTB4 stimulates bone resorption in part by enhancing the formation of osteoclasts. (J Bone Miner Res 1996;11:1619‐1627)
Duodenal active calcium transport in female rats increases with serum calcitriol concentrations, but reaches a plateau far below maximal calcitriol levels
Authors: Boass Agna , Dr. Toverud Svein U.
Published: February 2010

To determine the relationship between serum calcitriol concentration and duodenal active calcium (Ca) transport, a wide range of circulating calcitriol concentrations (18-950 pg/ml) was obtained by feeding nonmated, lactating, and weaned rats vitamin D-sufficient diets containing 0.04, 0.06, 0.1, or 0.4% Ca. Ca transport was measured in vitro with the everted gut sac technique using both the proximal (D-1) and distal (D-2) duodenal halves. The ratio of serosal [Ca]/mucosal [Ca] (S/M) as well as the amount of Ca transported was calculated. The S/M ratio correlated with the serum calcitriol concentration over the range 18–90 pg/ml with slopes for the regression lines of 0.066 ± 0.010 (R2 = 0.64, n = 27) for D-1 and of 0.036 ± 0.005 (R2 = 0.73, n = 24) for D-2. The regression lines are significantly different from zero (p < 0.001) and from each other (p < 0.01). For D-1, a plateau of the S/M ratio of 7–9 appeared to be reached at a calcitriol concentration of approximately 90 pg/ml, and the plateau was maintained over the range 90–900 pg/ml calcitriol. For D-2, a plateau of the S/M ratio of 4–6 appeared to be reached at 200–300 pg/ml calcitriol. Calculating the amount of Ca transported per 10 cm per hour revealed a pattern similar to that of the S/M ratio. When net Ca absorption was determined from balance studies over 4 days for rats on a 0.04% Ca diet, maximal absorption (mg/day) was already observed at a serum calcitriol concentration of 60–70 pg/ml (n = 14). We conclude that active Ca transport correlates with serum calcitriol concentrations, but that the transport capacity quickly reaches a maximal value, which is maintained over a 10-fold higher range of serum calcitriol concentrations. (J Bone Miner Res 1996;11:1640–1645)
Establishment of a novel chondrocyte-like cell line derived from transgenic mice harboring the temperature-sensitive simian virus 40 large T-antigen gene
Authors: Mataga Nobuko , Tamura Masato , Yanai Nobuyuki , Shinomura Tamayuki , Kimata Koji , Obinata Masuo , Noda Masaki
Published: February 2010

We established a clonal chondrocyte-like cell line (TC6, TC stands for large T immortalized chondrocyte-like cell line) derived from articular cartilage of transgenic mice harboring a temperature-sensitive simian virus 40 large T-antigen gene. TC6 cells exhibited spindle-like or polygonal morphology and grew well at 33°C in alpha-minimal essential medium supplemented with 0.5% fetal bovine serum. After confluence, these cells formed nodules that were positive for staining with alcian blue. Northern blot analysis demonstrated that these cells expressed messenger RNAs (mRNA) of the genes encoding cartilage-specific proteins such as type II procollagen, link protein, and aggrecan. Furthermore, the expression of type II procollagen and link protein genes in TC6 cells was regulated by parathyroid hormone and basic fibroblast growth factor, suggesting the presence of the receptors for the hormone and cytokine. The expression of link protein mRNA in TC6 cells was regulated in a time-dependent manner and was enhanced in culture within a week and increased continuously up to 10-fold by the end of 4 weeks. Expression of mRNAs encoding type II procollagen and versican/PG-M also increased moderately during the culture period. TC6 cells expressed type I procollagen mRNA, however, its level declined along with time in culture in contrast to the enhancement of the genes encoding cartilage-specific molecules in these cells. Interestingly, alkaline phosphatase mRNA expression was barely detectable in the TC6 cells in their growing phase while it was enhanced dramatically more than 7-fold by day 14 in culture. These results indicate that the TC6 cells could serve as an excellent model for the studies on chondrocyte physiology. (J Bone Miner Res 1996;11:1646–1654)
Role of protein kinase Cα, arf, and cytoplasmic calcium transients in phospholipase D activation by sodium fluoride in osteoblast-like cells
Authors: Bourgoin Sylvain G. , Harbour Danielle , Poubelle Patrice E.
Published: February 2010

The effect of fluoride on phospholipase D (PLD) activation was studied using in vitro culture of Saos-2, MG-63 osteosarcoma cells, and normal osteoblast-like cells derived from human bone explants. Millimolar concentrations of NaF induced a significant accumulation of phosphatidylethanol (PEt) in Saos-2 cells but not in MG-63 and normal osteoblast-like cells. PLD activation was evident at 15 mM and concentration-dependent up to 50 mM. This stimulation was inhibited by deferoxamine, a chelator of Al3+, suggesting that PLD activation involves fluoride-sensitive G proteins. A good correlation was found between the levels of intracellular free Ca2+ and the activation of PLD. The time courses of the two responses were nearly identical. The ability of NaF to induce both responses was largely dependent on the presence of extracellular calcium. The calcium ionophore A23187 reproduced the effect of NaF, and this effect was antagonized by EGTA, suggesting that PLD activation was, at least in part, a calcium-regulated event. Phorbol 12-myristate 13-acetate (PMA) also stimulated PLD activity in human bone cells. Protein kinase C alpha (PKCα) and ε were expressed in Saos-2 cells. Acute pretreatment of cells with PMA reduced concomitantly the amounts of PKCα, but not of PKCε, and the subsequent activation of PLD elicited by PKC activators. The PLD response to NaF was not attenuated but rather enhanced by down-regulation of PKCα. Therefore, PKCα-induced PLD activation is unlikely to mediate the effect of NaF. Moreover, PMA and NaF showed a supraadditive effect on PLD activation in Saos-2 cells. This stimulation, in contrast to NaF alone, was not reduced by EGTA. Hence, mobilization of calcium by NaF cannot account for the enhanced PLD activation in response to PMA stimulation. Membrane Arf and RhoA contents were assessed by Western immunoblot analyses. Membranes derived from NaF-stimulated Saos-2 cells contained more Arf and RhoA when compared with membranes derived from control or PMA-stimulated cells. Translocation of the small GTPases was calcium-independent. We conclude that PLD activation by NaF in Saos-2 cells includes a fluoride-sensitive G protein, increases in the levels of intracellular calcium, and Arf/RhoA redistribution to membranes. The results also indicate that the NaF-induced Arf/RhoA translocation exerts in concert with PMA-activated PKCα a synergistic effect on the activation of PLD in Saos-2 cells. (J Bone Miner Res 1996;11:1655-1665)
Bone structure and turnover in the distal radius and iliac crest: A histomorphometric study
Authors: Schnitzler Christine M. , Biddulph Sydney L. , Mesquita Julia M. , Gear K. Ann
Published: February 2010

In bone grafting procedures of the wrist, the distal radius would be a more convenient graft donor site than the conventionally used iliac crest. We compared tetracycline-labeled bone biopsies from these two sites in 18 white patients (12 males, 6 females, aged 26–66 years) undergoing bone grafting procedures of the wrist. Fourteen had had previous trauma, 1 osteonecrosis of the lunate, 2 mild rheumatoid arthritis, and 1 a brachial plexus palsy. The specimens were processed undecalcified and examined by routine histomorphometry for bone structure, static and dynamic bone turnover variables, and marrow cellularity. We found that bone from the distal radius had thinner cortices (p = 0.0001), lower bone volume (p = 0.01), thinner trabeculae (p = 0.029), greater trabecular separation (p = 0.015), and lower wall thickness (p = 0.0001), marrow cellularity (p = 0.0001), osteoid volume (p = 0.01), osteoid surface (p = 0.02), osteoid thickness (p = 0.0002), osteoblast surface (p = 0.001), eroded surface (p = 0.01), osteoclast surface (p = 0.012), mineral apposition rate (p = 0.0002), double-labeled surface (p = 0.0005), single-labeled surface (p = 0.006), bone formation rate (p = 0.0005), adjusted apposition rate (p = 0.0001), longer mineralization lag time (p = 0.012), and greater activation frequency (p = 0.003). Prolonged mineralization lag time in the radius was associated with thin osteoid seams and low adjusted apposition rates and was therefore attributable to a low level of osteoblast activity rather than to osteomalacia. We conclude that bone from the distal radius was structurally inferior to and had lower turnover than the iliac crest bone. We suggest that where a graft has to provide immediate structural integrity, the iliac crest is the preferred donor site. However, where bone graft is to be compacted into a small cavitary defect, distal radial bone may be an adequate alternative. A clinical study is needed to confirm this assumption. (J Bone Miner Res 1996;11:1761–1768)
A hollow fiber membrane photo‐bioreactor for CO2 sequestration from combustion gas coupled with wastewater treatment: a process engineering approach
Authors: Kumar Amit , Yuan Xin , Sahu Ashish K , Dewulf Jo , Ergas Sarina J , Van Langenhove Herman
Published: February 2010

BACKGROUND: In the presence of light, micro‐algae convert CO2 and nutrients to biomass that can be used as a biofuel. In closed photo‐bioreactors, however, light and CO2 availability often limit algae production and can be difficult to control using traditional diffuser systems. In this research, a hollow fiber membrane photo‐bioreactor (HFMPB) was investigated to: (1) increase the interfacial contact area available for gas transfer, (2) treat high nutrient strength (412 mg NO3−‐N L−1) wastewater, and (3) produce algal biomass that can be used as a biofuel.

RESULTS: A bench scale HFMPB was inoculated with Spirulina platensis and operated with a 2‐15% CO2 supply. A mass transfer model was developed and found to be a good tool to estimate CO2 mass transfer coefficients at varying liquid velocities. Overall mass transfer coefficients were 1.8 × 10−6, 2.8 × 10−6, 5.6 × 10−6m s−1 at Reynolds numbers of 38, 63, and 138, respectively. A maximum CO2 removal efficiency of 85% was observed at an inlet CO2 concentration of 2% and a gas residence time (membrane‐lumen) of 8.6 s. The corresponding algal biomass concentrations and NO3 removal efficiencies were 2131 mg L−1 and 68%, respectively.

CONCLUSION: The results show that the combination of CO2 sequestration, wastewater treatment and biofuel production in an HFMPB is a promising alternative for greenhouse gas mitigation. Copyright © 2010 Society of Chemical Industry
The characteristics of the sensible heat and momentum transfer coefficients over the Gobi in Northwest China
Authors: Zhang Qiang , Wang Sheng , Barlage Michael , Tian Wenshou , Huang Ronghui
Published: February 2010

Utilizing the data of the intensive observation period (May–June 2000) of the Dunhuang land‐surface process field experiment supported by the ‘Atmosphere‐land Interactive Field Experiment over Arid Regions of Northwest China(NWC‐ALIEX)’, the bulk momentum transfer coefficient (Cd) and the bulk sensible heat transfer coefficient (Ch) between the surface and the atmosphere over the arid Gobi Desert region are determined using three different methods. The results indicate that these coefficients, especially the means, are the same order of magnitude. The influence of the building near the observational station on the results is significant. When the building effect exists, the diurnal variation of the atmospheric bulk transfer coefficients and the bulk Richardson number are irregular. After the building effect is eliminated through analysing the wind direction, the bulk Richardson number and the range of the typical values of the bulk transfer coefficients over the Gobi are obtained. The diurnal variations of the bulk transfer coefficients are smoother than that without the building affect. The bulk transfer coefficients are larger in the daytime than in the nighttime. It is also worth noting that the variations of the bulk transfer coefficients and the bulk Richardson number are just opposite in phase, and that the bulk transfer coefficient for sensible heat flux is more related to the bulk Richardson number than that for momentum flux. The results are more reasonable than that after removing the building effect. The relation between the bulk transfer coefficients is also discussed. Copyright © 2010 Royal Meteorological Society
Raman spectroscopy of n‐pentyl methyl ether and deuterium labelled analogues
Authors: Bowen Richard D. , Edwards Howell G. M. , Farwell Dennis W. , Morgan Sara E
Published: February 2010

The Raman spectra of n‐pentyl methyl ether, C5H11OCH3, and six selectively deuteriated analogues are reported and discussed. Correlations between the observed ν(sp3CH) stretching and bending bands and the position of the deuterium atoms in the alkyl chain are developed and refined. Similar progress is possible in associating specific skeletal vibrations with bands in the Raman spectra. The relevance of this study to improving the assignment of bands in the Raman spectra of larger systems of biological interest is highlighted. Copyright © 2010 John Wiley & Sons, Ltd.
Experimental and theoretical evidence for the chemical mechanism in SERRS of rhodamine 6G adsorbed on colloidal silver excited at 1064 nm
Authors: Dong Bin , Liu Liwei , Xu Hongxing , Sun Mengtao
Published: February 2010

The evidence for the existence of a chemical mechanism in surface‐enhanced resonance Raman scattering (SERRS) of rhodamine 6G (R6G) adsorbed on colloidal silver excited at 1064 nm is reported on the basis of experimental and theoretical analyses. A weak absorption peak at around 1060 nm for R6G‐functionalized silver nanoparticles was observed, which is not present in the individual spectra of R6G or silver nanoparticles. Theoretically, the charge difference density reveals that this weak absorption is a metal‐to‐molecule charge transfer excited state. Copyright © 2010 John Wiley & Sons, Ltd.
Multifunctional human serum albumin in the surface‐enhanced Raman spectroscopy of porphyrin: demetalation promoter, molecular spacer and stabilizer
Authors: Jia Guoqing , Feng Zhaochi , Wei Chunying , Li Can
Published: February 2010

Human serum albumin (HSA), a model protein, was introduced to the surface‐enhanced Raman spectroscopy (SERS) of cationic porphyrin 5,10,15,20‐tetrakis(1‐methyl‐4‐pyridyl)‐21H,23H‐porphine (H2TMPyP4). HSA was found to have a great influence not only on Ag nanoparticle aggregation state but also on the interaction between Ag nanoparticle and H2TMPyP4 molecules. In the (H2TMPyP4‐Ag colloid)/HSA system, addition of H2TMPyP4 to Ag colloid led to a quick Ag colloid aggregation, and subsequent HSA addition could stabilize this system. The SERS spectrum was dominated by a combination of Ag(II)TMPyP4 and free base H2TMPyP4. More interestingly, a photoinduced demetalation of Ag(II)TMPyP4 to free base H2TMPyP4 was observed in the (H2TMPyP4‐Ag colloid)/HSA system. This demetalation process was partially reversible when the laser was turned off or the laser power was reduced. In this case, HSA acts as both a stabilizer and a demetalation promoter. In the (HSA‐H2TMPyP4)/Ag colloid system, when H2TMPyP4 was premixed with HSA prior to the Ag colloid addition, no obvious Ag colloid aggregation appeared, and the SERS spectrum was just characteristic of free base H2TMPyP4. In this case, HSA is proposed to function as both a stabilizer and a molecular spacer. Copyright © 2010 John Wiley & Sons, Ltd.
Modelling the biological variance of the yellow aspect of Granny Smith apple colour
Authors: Tijskens LMM , Schouten Rob E , Konopacki Pawel J , Hribar Janez , Simčič Marjan
Published: February 2010

BACKGROUND: The yellow aspect of colour is usually not considered for produce with a green‐to‐red or a green‐to‐yellow transition upon ripening. The magnitude of change is simply too small and, additionally, masked by a large variation. The colour of ‘Granny Smith’ apples, harvested from three orchards at two stages of maturity, was measured individually using the CIE L*a*b* system during storage in a regular atmosphere at three temperatures: 1, 4 and 10 °C. A model was developed based on a simplified mechanism, consisting of two consecutive reactions, to describe the development of the apple colour expressed as b* and L* values during storage.

RESULTS: Monitoring individual apples made it possible to include and describe the biological variance of colour in batches of apples and to extract information on chilling injury, as a process active at 1 °C. All variations could be attributed to a single source related to the amount of yellowing compounds at the moment of harvest, indicating differences in state of maturity between individual apples. The obtained explained part (R2adj), using nonlinear mixed effects regression analysis was well over 90% for all data combined over more than 3000 observations.

CONCLUSION: Orchard location had a slight effect on the mean initial colour value, indicating differences in development stage, most probably due to differences in assessing the harvest date. The magnitude of the variation in these colour values was, however, the same for all three orchards. The behaviour of the green colour aspect (a* value) has been reported separately, as this represents the major change in perceived colour. The changes in b* and L* values are rather small, while the biological variation between the individual fruit is at least of the same magnitude. The model presented here is, as far as known, the first model on b* and L* values for green‐coloured products. Analysing b* and L* data using this model provides additional information with respect to the stage of maturity at harvest in a batch or for an orchard of Granny Smith apples. All the variation in the yellow colour aspects could be attributed exclusively to the initial level of yellow compounds. Copyright © 2010 Society of Chemical Industry
The effect of AlloDerm on the initiation and growth of human neovessels
Authors: Weiss Sean R. , Tenney Justin M. , Thomson Jessica L. , Anthony Catherine T. , Chiu Ernest S. , Friedlander Paul L. , Woltering Eugene A.
Published: February 2010

Objectives/Hypothesis:

AlloDerm (LifeCell Corp., Branchburg, NJ) is commonly employed for reconstruction of ablative soft tissue and mucosal defects following surgical resections. Although devoid of growth factors, AlloDerm may serve as an adhesive matrix for binding of growth factors, increasing local angiogenesis, and wound healing. We hypothesized that AlloDerm would enhance angiogenesis and might be altered with autologous blood products to enhance initiation of the angiogenic response.

Methods:

We used a human placental vein in a fibrin‐thrombin clot‐based angiogenesis model. Four groups, human placental vein (HPVM), HPVM with AlloDerm, HPVM with AlloDerm plus platelet‐poor plasma, and HPVM with AlloDerm plus platelet‐rich plasma were evaluated. Endothelial cell growth was evaluated visually (40×). Hematoxylin and eosin staining and immunofluorescent staining for growth within the AlloDerm matrix were also performed. To assess human umbilical vein endothelial cell (HUVEC) sites of attachment to AlloDerm, we incubated HUVEC cells with AlloDerm for a period of 2 weeks and evaluated attachment with anti‐factor VIII immunofluorescence.

Results:

Angiogenic initiation decreased in the combined placental vein with AlloDerm group (P < .0001 at day 7, 14, 21). Additionally, initiation in the AlloDerm plus platelet‐poor plasma group was significantly better than the AlloDerm alone group when placentas 2 and 3 were compared (P < .0001). On hematoxylin and eosin staining and immunofluorescent factor VIII staining, no endothelial growth into the AlloDerm was noted in the samples analyzed.

Conclusions:

AlloDerm may be enriched with platelet‐poor plasma to stimulate greater initiation and wound healing; however, AlloDerm inhibits angiogenic initiation in this model. Laryngoscope, 2010
Tissue regeneration of the vocal fold using bone marrow mesenchymal stem cells and synthetic extracellular matrix injections in rats
Authors: Quinchia Johnson Beatriz , Fox Ryan , Chen Xia , Thibeault Susan
Published: February 2010

Objectives/Hypothesis.

To determine the effectiveness of bone marrow mesenchymal stem cell (BM‐MSC) transplantation in isolation or within a synthetic extracellular matrix (sECM) for tissue regeneration of the scarred vocal fold lamina propria.

Methods.

In vitro stability and compatibility of mouse BM‐MSC embedded in sECM was assessed by flow cytometry detection of BM‐MSC marker expression and proliferation. Eighteen rats were subjected to vocal fold injury bilaterally, followed by 1 month post‐treatment with unilateral injections of saline or sECM hydrogel (Extracel; Glycosan BioSystems, Inc., Salt Lake City, UT), green fluorescence protein (GFP)‐mouse BM‐MSC, or BM‐MSC suspended in sECM. Outcomes measured 1 month after treatment included procollagen‐III, fibronectin, hyaluronan synthase‐III (HAS3), hyaluronidase (HYAL3), smooth muscle actin (SMA), and transforming growth factor‐beta 1(TGF‐β1) mRNA expression. The persistence of GFP BM‐MSC, proliferation, apoptosis, and myofibroblast differentiation was assessed by immunofluorescence.

Results.

BM‐MSC grown in vitro within sECM express Sca‐1, are positive for hyaluronan receptor CD44, and continue to proliferate. In the in vivo study, groups injected with BM‐MSC had detectable GFP‐labeled BM‐MSC remaining and showed proliferation and low apoptotic or myofibroblast markers compared to the contralateral side. Embedded BM‐MSC in the sECM group exhibited increased levels of procollagen III, fibronectin, and TGF‐β1. BM‐MSC within sECM downregulated the expression of SMA compared to BM‐MSC alone and exhibited upregulation of HYAL3 and no change in HAS3 compared to saline.

Conclusions.

Treatment of vocal fold scarring with BM‐MSC injected in a sECM displayed the most favorable outcomes in ECM production, hyaluronan metabolism, myofibroblast differentiation, and production of TGF‐β1. Furthermore, the combined treatment had no detectable cytotoxicity and preserved local cell proliferation. Laryngoscope, 2010
Analysis of hearing preservation after endolymphatic mastoid sac surgery for Meniere's disease
Authors: Sun Gordon H. , Leung Randal , Samy Ravi N. , McAfee Jacob S. , Hearst Matthew J. , Savage Christopher R. , Choo Daniel I. , Pensak Myles L.
Published: February 2010

Objectives/Hypothesis:

Comparison of audiometric outcomes between patients with definite Meniere's disease who underwent endolymphatic mastoid sac surgery (EMSS) following failed medical therapy and patients who underwent medical therapy only.

Study Design:

Retrospective chart review of 456 consecutive patients between 1997 and 2006.

Methods:

Outcome measures were changes in pure‐tone average (PTA), word recognition score (WRS), and speech reception threshold (SRT).

Results:

Of 58 qualified patients, 29 who underwent EMSS after failing medical therapy showed a 4 dB decrease in PTA, a 2% increase in WRS, and a 2 dB decrease in SRT. Twenty‐nine patients treated with medical therapy only demonstrated a 1 dB PTA increase, 2% WRS improvement, and 2 dB SRT improvement. No significant difference was noted between the medically and surgically managed patients in terms of changes in PTA (P = .34) or WRS (P = .95) after treatment. Of all patients in the study, 60% had no clinically significant change in hearing, whereas 24% improved and 16% worsened. The distribution of post‐treatment hearing changes between the medical and surgical groups was statistically insignificant (P = .17).

Conclusions:

The changes in PTA and WRS among patients with Meniere's disease managed with medical therapy or EMSS were not statistically significant. Although performing EMSS to treat the vertigo of Meniere's disease does not appear to be associated with an increased risk of deteriorating auditory function after treatment, surgery also does not confer an increased likelihood of stabilizing or improving hearing. Laryngoscope, 2010
Outcomes of static and dynamic facial nerve repair in head and neck cancer
Authors: Iseli Tim A. , Harris Gregory , Dean Nichole R. , Iseli Claire E. , Rosenthal Eben L.
Published: February 2010

Objectives/Hypothesis:

Determine outcomes associated with nerve grafting versus static repair following facial nerve resection.

Study Design:

Retrospective chart review.

Methods:

Charts from 105 patients who underwent facial nerve reconstruction between January 1999 and January 2009 were reviewed. The majority had parotid malignancy (78.1%), most commonly squamous cell carcinoma (50.5%). Patients underwent static (n = 72) or dynamic (n = 33) reconstruction with nerve grafting. Facial nerve function was measured using the House‐Brackmann (H‐B) scale.

Results:

Patients receiving static reconstruction were on average 10.3 years older (P = .002). Mean overall survival for tumor cases was 61.9 months; parotid squamous cell carcinoma was associated with worse prognosis (P = .10). Median follow‐up was 16.1 months (range, 4–96.1 months). Most (97%) patients receiving a nerve graft had some return of function at a median of 6.2 months postoperatively (range, 4–9 months) and the majority (63.6%) had good function (H‐B score ≤4). Patients having static reconstruction (29.2%) were more likely to have symptomatic facial palsy than those having a nerve graft (15.2%, P = .12).

Conclusions:

Where possible, nerve grafting is the preferred method of facial nerve reconstruction. Although elderly patients with parotid malignancy have traditionally been considered poor candidates for nerve grafting, we demonstrate good results within 9 months of facial nerve repair even with radiotherapy, the use of long grafts (>6 cm), and prolonged preoperative dysfunction. Laryngoscope, 2010
Characterization of mesenchymal stem cells from human vocal fold fibroblasts
Authors: Hanson Summer E. , Kim Jaehyup , Johnson Beatriz H. Quinchia , Bradley Bridget , Breunig Melissa J. , Hematti Peiman , Thibeault Susan L.
Published: February 2010

Objectives/Hypothesis:

Mesenchymal stem cells (MSCs) originally isolated from bone marrow (BM), are fibroblast‐looking cells that are now assumed to be present in the stromal component of many tissues. MSCs are characterized by a certain set of criteria, including their growth culture characteristics, a combination of cell surface markers, and the ability to differentiate along multiple mesenchymal tissue lineages. We hypothesized that human vocal fold fibroblasts (hVFF) isolated from the lamina propria meet the criteria established to define MSCs and are functionally similar to MSCs derived from BM and adipose tissue.

Study Design:

In vitro study.

Methods:

hVFF were previously derived from human vocal fold tissues. MSCs were derived from adipose tissue (AT), and BM of healthy donors based on their attachment to culture dishes and their morphology and expanded in culture. Cells were analyzed for standard cell surface markers identified on BM‐derived MSCs and the ability to differentiate into cells of mesenchymal lineage (i.e., fat, bone, and cartilage). We investigated the immunophenotype of these cells before and after interferon‐γ (INF‐γ) stimulation.

Results:

hVFF displayed cell surface markers and multipotent differentiation capacity characteristic of MSCs. Furthermore, these cells exhibited similar patterns of expression of human leukocyte antigen and costimulatory molecules, after stimulation with INF‐γ compared to MSCs derived from BM and AT.

Conclusions:

Based on our findings, hVFF derived from lamina propria have the same cell surface markers, immunophenotypic characteristics, and differentiation potential as BM‐ and AT‐derived MSCs. We propose that vocal fold fibroblasts are MSCs resident in the vocal fold lamina propria. Laryngoscope, 2010
Tonsillectomy in post‐transplant lymphoproliferative disease in children
Authors: Sturm‐O'Brien Angela K. , Hicks M. John , Giannoni Carla M. , Sulek Marcelle , Friedman Ellen M.
Published: February 2010

Objectives/Hypothesis:

To review the role of tonsillectomy in diagnosis and management of post‐transplant lymphoproliferative disorder (PTLD).

Study Design:

Case series using a retrospective chart review.

Methods:

A retrospective review of post‐transplant lymphoproliferative disease at a tertiary academic medical center from January 2004 to April 2008. Data extracted includes patients' gender, age at transplantation, year of transplantation and tonsillectomy, type of transplant, presenting symptoms, type of immunosuppression, and outcome.

Results:

Six out of 25 (24%) patients who underwent tonsillectomy were found to have PTLD. The patient's characteristics, gender, age at transplantation, year of transplantation and tonsillectomy, type of transplant, presenting symptoms, type of immunosuppression, and outcomes are discussed.

Conclusions:

In our series, tonsillar hypertrophy, male gender, young age at transplantation, and liver transplantation were associated with higher rates of PTLD. Given the devastating nature of PTLD, early detection with tonsillectomy and institution of treatment is critical. Laryngoscope, 2010
Bone‐anchored hearing aid subjective benefit for unilateral deafness
Authors: House John W. , Kutz Joe Walter , Chung Janice , Fisher Laurel M.
Published: February 2010

Objectives/Hypothesis:

Determine the benefit of the bone‐anchored hearing aid (BAHA) in patients with unilateral deafness.

Study Design:

Retrospective case series and prospective questionnaire study at a tertiary referral center.

Methods:

Patients with unilateral deafness of various etiologies who were implanted with a BAHA (n = 126) or not implanted with a BAHA after a translabyrinthine craniotomy (n = 126) were mailed questionnaires. A total of 139 patients (55%) responded to the questionnaires. Patients who were implanted with a BAHA received a general questionnaire concerning BAHA usage, the Abbreviated Profile of Hearing Aid Benefit (APHAB), and the Speech, Spatial, and Qualities of Hearing Questionnaire (SSQ). Patients not implanted with a BAHA received only the SSQ hearing questionnaire.

Results:

Patients with unilateral deafness demonstrated a benefit with BAHA use on the APHAB. Most improvement with the BAHA was seen in the Background Noise subscale, with a 17.4% improvement. Ease of Communication and Reverberation subscales also demonstrated an 11.6% and 13.2% benefit, respectively. Patients with a BAHA demonstrated better scores in the SSQ Speech subscale when compared to unilaterally deaf patients who did not have a BAHA, although this difference was not significant.

Conclusions:

The APHAB demonstrated significant benefit with the use of a BAHA in patients with unilateral deafness. Although the SSQ speech subscale showed overall improvement in auditory disability with the use of a BAHA, this difference was not significant. However, the SSQ hearing questionnaire demonstrated specific situations were the BAHA is most useful. Laryngoscope, 2010
Molecular Structure Modulated Organization and Properties of Azobenzene‐Substituted Polydiacetylene Assemblies Films: Photopolymerization, Morphology, and Thermal Stability
Authors: Wang Yali , Chen Xin , Zou Gang , Zhang Qijin
Published: February 2010

Three accessible azobenzene mesogen‐substituted diacetylene monomers (DA1, DA2, and DA3) were synthesized and the effect of the molecular structure on the photopolymerization behavior and self‐assembled structures of the resulting azobenzene‐substituted polydiacetylene (PDA) films had been investigated in detail. The films derived from DA1 were substantially polymerized into blue phase. However, the films derived from DA2 and DA3 were polymerized into red phase directly. The morphology, packing structure, and thermal stability of the resulting azobenzene‐substituted PDA films were characterized in detail by SEM, XRD as well as POM measurements. PDA1 formed micrometer‐sized lamellar crystal structures, while PDA2 and PDA3 both formed spherulitic crystal structures. The strong π–π stacking interaction among side chains was essential for maintaining high stability upon thermal stimulus.

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Substituent Effects on RAFT Polymerization with Benzyl Aryl Trithiocarbonates
Authors: Bicciocchi Erika , Chong Yen K. , Giorgini Loris , Moad Graeme , Rizzardo Ezio , Thang San H.
Published: February 2010

The RAFT polymerization of styrene in the presence of benzyl aryl trithiocarbonate RAFT agents (Z′SC(=S)SR) has been studied. The values of the apparent transfer constants of the benzyl aryl trithiocarbonates (0.029 M) in bulk styrene polymerization at 110 °C fall within the range 10–25 depending on substituents on the aryl ring (Z′) and are higher than that of benzyl dodecyl trithiocarbonate 1 for which was determined to be 9.4. There is a trend for higher transfer constant, lower dispersity product and better control over polymerization with more electron‐withdrawing substituents with the most active in the series studied being the 3,5‐bis(trifluoromethyl)phenyl derivative.

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Hydroxyl‐Functionalized Norbornene Based Co‐ and Terpolymers by Scandium Half‐Sandwich Catalyst
Authors: Tritto Incoronata , Ravasio Andrea , Boggioni Laura , Bertini Fabio , Hitzbleck Julia , Okuda Jun
Published: February 2010

Copolymerization of ethylene with 5‐norbornene‐2‐methanol and terpolymerization of ethylene with norbornene and 5‐norbornene‐2‐methanol by a rare‐earth metal based catalyst, specifically the half‐sandwich bis(alkyl) scandium precursor [Sc(η5‐C5Me4SiMe3)(η1‐CH2SiMe3)2(THF)] activated by [Ph3C][B(C6F5)4] were successfully achieved for the first time. A protocol for masking of OH functionality by AliBu3 to avoid catalyst poisoning was exploited. Copolymers with high molar masses and noticeable incorporation of functionalized norbornene derivative were obtained. Terpolymers with very high molar masses and with a broad range of composition were prepared with excellent yields.

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The Development and Characterization of Starch Microspheres Prepared by a Sonochemical Method for the Potential Drug Delivery of Insulin
Authors: Grinberg Olga , Gedanken Aharon
Published: February 2010

This study deals with the production of starch microspheres containing insulin using the sonochemical technique. The structure and properties of the final product were studied using SEM, FTIR and XRD. A microsphere size of 600 nm and the size distribution of the starch microspheres with encapsulated insulin were determined. A spectrophotometric analytical procedure was selected to evaluate the amount of loaded insulin in the starch microspheres and to perform the release studies. The product is organized in a double‐layer structure (insulin layer covered by starch layer), and this composite may provide a new system for the administration of protein drugs. The microspherilization process involves the degradation of the starch to the smaller fragments due to the application of high‐intensity ultrasound, and the organization of these fragments in a microsphere structure using the same type of bonds as in regular starch.

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