bluuebunny/crossref_metadata_2025 huggingface dataset:
V-Shaped Polyoxotungstoarsenates Incorporating a Prism-Like Hexa Transition-Metals Center: [M6(H2O)2(AsW9O34)2(AsW6O26)]17− (M2+ = Mn2+, Co2+, Zn2+)
Authors: Fukaya Keisuke , Yamase Toshihiro
Published: January 2007

Hexa transition-metals incorporated polyoxotungstoarsenates, [M6(H2O)2(AsW9O34)2(AsW6O26)]17− (M2+ = Mn2+, Co2+I, Zn2+), have been prepared at pH 7–8 and characterized by elemental analysis, electrochemistry, and X-ray crystallography: Na17[Mn6(H2O)2(AsW9O34)2(AsW6O26)]·41H2O (1), P21/c, a = 17.73(1) Å, b = 22.34(1) Å, c = 35.41(3) Å, β = 95.37(3)°, V = 13963(14) Å3, and Z = 4; Na17[Co6(H2O)2(AsW9O34)2(AsW6O26)]·41H2O (2), P21/c, a = 17.65(1) Å, b = 22.24(1) Å, c = 34.78(2) Å, β = 95.84(2)°, V = 13584(13) Å3, and Z = 4; Na17[Zn6(H2O)2(AsW9O34)2(AsW6O26)]·38H2O (3), P21/c, a = 17.6295(6) Å, b = 22.2992(7) Å, c = 34.927(1) Å, β = 95.695(2)°, V = 13662.8(7) Å3, and Z = 4. The anion of 1–3 consists of two B-α [{M(H2O)}M2(AsW9O34)]3− units joined by a B-type hexa-vacant [AsW6O26]11− fragment, corresponding to a removal of the edge-sharing W3O8 moiety from B-α [AsW9O34]9−, to form a C2v-symmetric V-shaped geometry. Two edge-sharing MO6-octahedral triads (with M···M distances 3.2–3.4 Å) are well-separated with M···M distances of 5.5–8.9 Å. Three successive electrochemically quasi-reversible two-electron MnII/MnIII waves were observed in the cyclic voltammogram of 1. M2+ ion with larger radius causes an elongation of the As···As distances. A single Na+ cation coordinated by three oxygen atoms (two belonging to B-α [AsW9O34]9− and one belonging to B-[AsW6O26]11−) in the crevice of the anion stabilizes the V-shaped structure.
Ion-Association Extraction of Nitrobenzoate Ions with Tetrabutylammonium Ion into Nonionic Surfactant Micelles as Studied by Capillary Zone Electrophoresis
Authors: Takayanagi Toshio , Motomizu Shoji
Published: January 2007

Ion-associates formed between tetrabutylammonium ion (TBA+) and substituted nitrobenzoate ions have been extracted into nonionic surfactant micelles in an aqueous solution. The micelle extraction property of the ion-associates was investigated through the changes in electrophoretic mobility in capillary zone electrophoresis, in which a nonionic surfactant, Brij 35 or Brij 58, was used as a micelle substrate. Prior to the extraction analysis, ion-association constants (Kass) between TBA+ and the benzoate ions as well as binding constants of the anions to the nonionic surfactant micelle (KB) were determined through the mobility change. Binding of the ion-associates from aqueous to the micelle phases was observed, when both TBA+ and the nonionic surfactant were present in the migrating solution. Micelle extraction constants for the ion-associates (Kex,m), were also determined by using the mobility change, and the values were compared with the ion-association solvent extraction constants between water and chloroform.
Synthesis and Characterization of a Novel Chiral Molecular-Based Ferrimagnet Prepared from a Chiral Nitronyl Nitroxide Radical and Manganese(II) Ion
Authors: Akita-Tanaka Motoko , Kumagai Hitoshi , Markosyan Ashot , Inoue Katsuya
Published: January 2007

A new chiral organic radical, 4,4,5,5-tetramethyl-2-{4-[(S)-2-methylbutoxy]phenyl}-3-oxido-4,5-dihydroimidazol-1-oxyl (1) and its MnII complex ([1·MnII(hfac)2]n (hfac = hexafluoroacetylacetonato)) were synthesized and characterized. From single crystal X-ray structure analysis, 1 and [1·MnII(hfac)2]n have a chiral space group (P212121), and [1·MnII(hfac)2]n has a one-dimensional helical structure. Magnetic susceptibility measurements of [1·MnII(hfac)2]n indicate that this heterospin system behaves as a ferrimagnet with very weak interchain ferromagnetic exchange interaction.
Preparation and Characterization of Nanomaterials of Tellurium, Bismuth, and Bismuth Telluride
Authors: Watanabe Norihisa , Toshima Naoki
Published: January 2007

In order to improve the processing and performance of tellurium (Te), bismuth (Bi), and bismuth telluride (dibismuth tritelluride, Bi2Te3), which are valuable thermoelectric materials that operate near room temperature in the bulk state, a nanometer scale synthetic method, in which the starting materials are reduced with NaBH4 in the presence of protecting agents in solution under mild conditions, was used. Te nanorods having an average diameter of 10 ± 3 nm (aspect ratio = 3.0) were prepared by reducing tellurium(IV) ethoxide in ethanol in the presence of poly(N-vinyl-2-pyrrolidone) (PVP) under nitrogen. Although Bi nanoparticles prepared from bismuth(III) chloride by this method have an average diameter of 29 ± 8 nm, PVP-protected Bi2Te3 nanoparticles have a really small average diameter (7 ± 5 nm) and they are probably the smallest Bi2Te3 particles ever reported. Heat treatment of PVP-protected Bi2Te3 nanoparticles in refluxing solvents was found to improve the stability.
Shape-Selective Alkylation of Biphenyl over H-[Al]-SSZ-24 Zeolites with AFI Topology
Authors: Ito Akira , Maekawa Hiroyoshi , Kawagoe Hiroaki , Komura Kenichi , Kubota Yoshihiro , Sugi Yoshihiro
Published: January 2007

H-[Al]-SSZ-24 zeolites with AFI topology were synthesized through the alumination of [B]-SSZ-24 zeolites, and applied for the alkylation of biphenyl (BP). H-[Al]-SSZ-24 zeolites have high activity for the isopropylation. The shape-selective formation of 4,4′-diisopropylbiphenyl (4,4′-DIPB) occurred at moderate temperature; however, the selectivity for 4,4′-DIPB decreased with an increase in the reaction temperature. Isomerization of 4,4′-DIPB occurred at higher temperatures over internal and external acid sites when there are enough acid sites inside the channels. The channels can discriminate 4,4′-DIPB from the other DIPB isomers in their transition states; however, they can not prevent the isomerization of 4,4′-DIPB at higher temperatures. The selectivity for the least bulky 4,4′-dialkylbiphenyl increased with the bulkiness of alkylating agents in the order: isopropylation < s-butylation < t-butylation. These results strongly support the shape-selective formation of the least bulky products inside the channels of H-[Al]-SSZ-24 zeolites.
Preparation of Monodispersed Cu Nanoparticles by Microwave-Assisted Alcohol Reduction
Authors: Nakamura Takashi , Tsukahara Yasunori , Sakata Takao , Mori Hirotaro , Kanbe Yumi , Bessho Hisami , Wada Yuji
Published: January 2007

Copper (Cu) nanoparticles were prepared via a microwave-assisted alcohol reduction process. We have succeeded in selectively preparing monodispersed Cu nanoparticles with or without surface plasmon absorption. Monodispersed Cu nanoparticles with average sizes of 5–6 nm (with the surface plasmon absorption) and 2–3 nm (without the surface plasmon absorption) were prepared using copper(II) octanoate and copper(II) myristate, respectively, as the copper precursors by reduction with alcohols under microwave-heating at 443 K for 20 min. Noteworthy, Cu2O and CuO were not observed in the electron diffraction patterns of the prepared Cu nanoparticles, demonstrating chemical stability of the nanoparticles against oxidation in air. When using a long-chain carboxylate as an organic moiety bearing a short alkyl chain (copper(II) octanoate), the rate of the reduction was faster than long one (copper(II) myristate). The activation energies for the reduction of Cu2+ using copper(II) octanoate and copper(II) myristate were estimated to be 115 and 124 kJ mol−1, respectively. We have shown that the length of the alkyl chain contained in the copper precursors, heating temperature, and microwave-irradiation time are important for rapidly preparing monodispersed Cu nanoparticles.
An IGF-I gene polymorphism modifies the risk of developing persistent microalbuminuria in type 1 diabetes
Authors: Hovind Peter , Lamberts Steven , Hop Wim , Deinum Jaap , Tarnow Lise , Parving Hans-Henrik , Janssen Joop A M J L
Published: January 2007

Objective: Derangements of the GH–IGF-I axis have been associated with microalbuminuria (MA) in type 1 diabetes. The aim of this study was to investigate whether anIGF-Igene promoter polymorphism influenced the development of persistent MA in type 1 diabetes.

Design: A prospective follow-up study of a cohort of 277 patients with newly diagnosed type 1 diabetes consecutively enrolled between September 1979 and August 1984.

Methods: Urinary albumin excretion rate over 24 h was measured in each patient at least once a year. Persistent MA was defined as a urinary albumin excretion rate between 30 and 300 mg/24 h.

Results: During a median follow-up of 18.0 years (range 1.0–21.5), 79 of 277 patients developed persistent MA.IGF-Igene genotype was available for 216 subjects; in 73% of the subjects, the wild-type genotype of this IGF-I gene polymorphism was present, while 27% had the variant type. At baseline, there were no differences in IGF-I levels and HbA1cvalues between subjects with the wild type and subjects with variant type. By Kaplan–Meier analysis, subjects with the variant type of this polymorphism had during follow-up a higher risk of development of MA compared subjects with the wild type (P= 0.03).

Conclusions: Subjects with the variant type of anIGF-Igene polymorphism had a significantly increased risk of developing MA. This risk was not mediated through changes in circulating IGF-I levels. Our study suggests that in type 1 diabetes, thisIGF-Igene polymorphism is a risk factor of MA.
Bone mineral density and hip structural analysis in type 1 diabetic men
Authors: Miazgowski Tomasz , Pynka Slawomir , Noworyta-Ziętara Marzena , Krzyzanowska-Świniarska Barbara , Pikul Robert
Published: January 2007

Objective: The risk of non-vertebral fractures is increased in men with type 1 diabetes (DM1) but studies have shown only moderately decreased or normal bone mineral density (BMD) in these patients. No previous studies have evaluated hip strength and geometry indices in DM1 patients. This study was therefore designed to characterize associations between BMD, dual X-ray absorptiometry (DXA)-based hip strength indices, metabolic control, and DM1chronic complications.

Design and methods: The study was performed on 36 males aged 43.6 ± 5.1 years with long-lasting DM1 and 36 healthy males matched for age, weight, and height. BMD in lumbar spine, total hip, upper and lower part of the femoral neck, hip axis length, cross-sectional area and moment of inertia (CSMI), and glycated hemoglobin (HbA1c) were measured.

Results: DM1 men had decreased spine BMD (P< 0.05) and normal total hip BMD in comparison with controls. Hip geometry and strength indices were comparable in both groups. However, M1 men had decreased CSMI and upper femur BMD but these differences did not reach statistical significance (P= 0.06). BMD changes and hip strength parameters did not correlate with HbA1c.

Conclusions: Middle-aged DM1 men have decreased lumbar spine BMD, normal hip BMD and normal hip strength indices. These changes are not influenced by metabolic control and presence of chronic microvascular complications.
The endocrine system in chronic nitric oxide deficiency
Authors: Vargas Félix , Moreno Juan Manuel , Wangensteen Rosemary , Rodríguez-Gómez Isabel , García-Estañ Joaquín
Published: January 2007

The experimental model of chronic inhibition of nitric oxide (NO) production has proven to be a useful tool to study cardiovascular and renal lesions produced by this type of hypertension, which are similar to those found in human hypertension. It also offers a unique opportunity to study the interaction of NO with the humoral systems, known to have a role in the normal physiology of vascular tone and renal function. This review provides a thorough and updated analysis of the interactions of NO with the endocrine system. There is special focus on the main vasoactive factors, including the renin-angiotensin-aldosterone system, catecholamines, vasopressin, and endothelin among others. Recent discoveries of crosstalk between the endocrine system and NO are also reported. Study of these humoral interactions indicates that NO is a molecule with ubiquitous function and that its inhibition alters virtually to all other known regulatory systems. Thus, hypothyroidism attenuates the pressor effect of NO inhibitor N-nitro-L-arginine methyl ester, whereas hyperthyroidism aggravates the effects of NO synthesis inhibition; the sex hormone environment determines the blood pressure response to NO blockade; NO may play a homeostatic role against the prohypertensive effects of mineralocorticoids, thyroid hormones and insulin; and finally, NO deficiency affects not only blood pressure but also glucose and lipid homeostasis, mimicking the human metabolic syndrome X, suggesting that NO deficiency may be a link between metabolic and cardiovascular disease.
Ten-year GH replacement increases bone mineral density in hypopituitary patients with adult onset GH deficiency
Authors: Götherström G , Bengtsson B-Å , Bosæus I , Johannsson G , Svensson J
Published: January 2007

There are few studies that have determined the effects of long-term GH replacement on bone mineral density (BMD) in GH-deficient (GHD) adults. In this study, the effects of 10 years of GH replacement on BMD were assessed in 87 GHD adults using dual energy X-ray absorptiometry (DEXA). The results show that GH replacement induced a sustained increase in BMD at all the skeletal sites measured.

Introduction: Little is known of the effect of more than 5 years of GH replacement therapy on bone metabolism in GHD adults.

Patients and methods: In this prospective, open-label, single-center study, which included 87 consecutive adults (52 men and 35 women; mean age of 44.1 (range 22–74) years) with adulthood onset GHD, the effect of 10 years of GH replacement on BMD was determined.

Results: The mean initial dose of GH was 0.98 mg/day. The dose was gradually lowered and after 10 years the mean dose was 0.47 mg/day. The mean insulin-like growth factor-I (IGF-I) SDS increased from 1.81 at baseline to 1.29 at study end. The GH replacement induced a sustained increase in total, lumbar (L2–L4) and femur neck BMD, and bone mineral content (BMC) as measured by DEXA. The treatment response in IGF-I SDS was more marked in men, whereas women had a more marked increase in the total body BMC and the total body z-score. There was a tendency for women on estrogen treatment to have a larger increase in bone mass and density compared with women without estrogen replacement.

Conclusions: Ten years of GH replacement in hypopituitary adults induced a sustained, and in some variables even a progressive, increase in bone mass and bone density. The study results also suggest that adequate estrogen replacement is needed in order to have an optimal response in BMD in GHD women.
Biochemical severity of thyroid ectopia in congenital hypothyroidism demonstrates sexual dimorphism
Authors: Ng S M , Wong S C , Isherwood D M , Didi M
Published: January 2007

Background: A recent study suggested that sexual dimorphism affects initial thyroid function in congenital hypothyroidism (CH) but differs according to aetiology of CH.

Aims: To determine if sexual dimorphism was associated with biochemical severity of CH and its aetiology in our large British population.

Methods: We examined retrospectively the initial thyroid function tests of 140 infants diagnosed with CH from screening. All infants underwent Tc-pertechnetate radionuclide scans at diagnosis to establish the aetiology of CH prior to commencement of treatment. Patients were classified into athyreosis, ectopia and presumed dyshormonogenesis on the basis of thyroid scans. A comparison of males and females were made within the three aetiological groups for gestational age, birth weight, initial dose of levothyroxine (LT4), screening TSH, confirmatory plasma thyroxine (T4), confirmatory plasma TSH and age of TSH suppression.

Results: There was no significant difference between sexes for gestation, birth weight and initial treatment dose in all aetiological subgroups. In thyroid ectopia, screening TSH and confirmatory plasma TSH were significantly higher in females compared with males (P < 0.01), while confirmatory plasma T4 were significantly lower in females (P < 0.05). No difference was detected between males and females in athyreosis and dyshormonogenesis subgroups for screening TSH, confirmatory plasma TSH and total T4.

Conclusion: Sexual dimorphism influenced the biochemical severity of thyroid ectopia in congenital hypothyroidism in our British population. However, this effect was not apparent in patients with athyreosis or dyshormonogenesis. Further advances in the molecular genetics of CH are essential to evaluate this phenomenon further.
Increased preoperative glucose levels are associated with perioperative mortality in patients undergoing noncardiac, nonvascular surgery
Authors: Noordzij Peter G , Boersma Eric , Schreiner Frodo , Kertai Miklos D , Feringa Harm H H , Dunkelgrun Martin , Bax Jeroen J , Klein Jan , Poldermans Don
Published: January 2007

Objective: To determine the relationship between preoperative glucose levels and perioperative mortality in noncardiac, nonvascular surgery.

Research design and methods: We performed a case–control study in a cohort of 108 593 patients who underwent noncardiac surgery at the Erasmus MC during 1991–2001. Cases were 989 patients who underwent elective noncardiac, nonvascular surgery and died within 30 days during hospital stay. From the remaining patients, 1879 matched controls (age, sex, calendar year, and type of surgery) were selected. Information was obtained regarding the presence of cardiac risk factors, medication, and preoperative laboratory results. Preoperative random glucose levels <5.6 mmol/l (110 mg/dl) were normal. Impaired glucose levels in the range of 5.6–11.1 mmol/l were prediabetes. Glucose levels ≥11.1 mmol/l (200 mg/dl) were diabetes.

Results: Preoperative glucose levels were available in 904 cases and 1247 controls. A cardiovascular complication was the primary cause of death in 207 (23%) cases. Prediabetes glucose levels were associated with a 1.7-fold increased mortality risk compared with normoglycemic levels (adjusted odds ratio (OR) 1.7 and 95% confidence interval (CI) 1.4–2.1; P<0.001). Diabetes glucose levels were associated with a 2.1-fold increased risk (adjusted OR 2.1 and 95% CI 1.3–3.5; P<0.001). In cases with cardiovascular death, prediabetes glucose levels had a threefold increased cardiovascular mortality risk (adjusted OR 3.0 and 95% CI 1.7–5.1) and diabetes glucose levels had a fourfold increased cardiovascular mortality risk (OR 4.0 and 95% CI 1.3–12).

Conclusions: Preoperative hyperglycemia is associated with increased (cardiovascular) mortality in patients undergoing noncardiac, nonvascular surgery.
Gamma knife radiosurgery is a successful adjunctive treatment in Cushing’s disease
Authors: Castinetti F , Nagai M , Dufour H , Kuhn J-M , Morange I , Jaquet P , Conte-Devolx B , Regis J , Brue T
Published: January 2007

Objective: Though transsphenoidal surgery remains the first-line treatment of Cushing’s disease, recurrence occurs frequently. Conventional radiotherapy and anticortisolic drugs both have adverse effects. Stereotactic radiosurgery needs to be evaluated more precisely. The aim of this study was to determine long-term hormonal effects and tolerance of gamma knife (GK) radiosurgery in Cushing’s disease.

Design: Forty patients with Cushing’s disease treated by GK were prospectively studied over a decade, with a mean follow-up of 54.7 months. Eleven of them were treated with GK as a primary treatment.

Methods: Radiosurgery was performed at the Department of Functional Neurosurgery of Marseille, France, using the Leksell Gamma Unit B and C models. Median margin dose was 29.5 Gy. Patients were considered in remission if they had normalized 24-h free urinary cortisol and suppression of plasma cortisol after low-dose dexamethasone suppression test.

Results: Seventeen patients (42.5%) were in remission after a mean of 22 months (range 12–48 months). The two groups did not differ in terms of initial hormonal levels. Target volume was significantly higher in uncured than in remission group (909.8 vs 443 mm3, P = 0.038). We found a significant difference between patients who were on or off anticortisolic drugs at the time of GK (20 vs 48% patients in remission respectively, P = 0.02).

Conclusion: With 42% of patients in remission after a median follow-up of 54 months, GK stereotactic radiosurgery, especially as an adjunctive treatment to surgery, may represent an alternative to other therapeutic options in view of their adverse effects.
Treatment of Graves’ disease and associated ophthalmopathy with the anti-CD20 monoclonal antibody rituximab: an open study
Authors: Salvi Mario , Vannucchi Guia , Campi Irene , Currò Nicola , Dazzi Davide , Simonetta Simona , Bonara Paola , Rossi Stefania , Sina Clara , Guastella Claudio , Ratiglia Roberto , Beck-Peccoz Paolo
Published: January 2007

Introduction: Hyperthyroid Graves’ disease (GD) is a B-cell-mediated condition caused by TSH receptor antibodies (TRAb), which decline when GD remits. Anti-CD20 monoclonal antibody rituximab (RTX) induces transient B-cell depletion that may potentially modify the active inflammatory phase of thyroid-associated ophthalmopathy (TAO).

Methods: Nine patients with GD, (seven with active TAO, two with mild lid signs) were studied. The trial was only approved as an open pilot study; thus we compared the effect of RTX therapy to that of i.v. glucocorticoids (IVGC) in 20 consecutive patients. Patients were treated with RTX (1000 mg i.v. twice at 2-week interval) or with IVGC (500 mg i.v. for 16 weeks). TAO was assessed by the clinical activity score (CAS) and severity was classified using NOSPECS (No signs or symptoms; Only signs (lid); Soft tissue involvement; Proptosis, Extraocular muscle involvement; Corneal involvement; Sight loss). Thyroid function and lymphocyte count were measured by standardized methods.

Results: All patients attained peripheral B-cell depletion with the first RTX infusion. Minor side effects were reported in three patients. Thyroid function was not affected by RTX therapy and hyperthyroid patients required therapy with methimazole. After RTX, the changes in the levels of thyroglobulin antibodies, thyroperoxidase antibodies and TRAb were neither significant nor correlated with CD20+ depletion (P = NS). CAS values before RTX were 4.7 ± 0.5 and decreased to 1.8 ± 0.8 at the end of follow-up (P < 0.0001) and more significantly compared with IVGC (P < 0.05). Proptosis decreased significantly after RTX both in patients with active TAO (ANOVA; P < 0.0001) and those with lid signs (ANOVA; P < 0.003). The degree of inflammation (class 2) decreased significantly in response to RTX (ANOVA; P < 0.001). Relapse of active TAO was not observed in patients treated with RTX, but occurred in 10% of those treated with IVGC, who also experienced adverse effects more frequently (45 vs 33% of patients).

Conclusions: RTX positively affects the clinical course of TAO, independently of either thyroid function or circulating antithyroid antibodies, including TRAb. If our findings are confirmed in large controlled studies, RTX may represent a useful therapeutic tool in patients with active TAO.
Two Distinct Stem Cell Lineages in Murine Bone Marrow
Authors: Koide Yoko , Morikawa Satoru , Mabuchi Yo , Muguruma Yukari , Hiratsu Emi , Hasegawa Kohji , Kobayashi Makoto , Ando Kiyoshi , Kinjo Kentaro , Okano Hideyuki , Matsuzaki Yumi
Published: January 2007

Mesenchymal stem cells (MSC), a distinct type of adult stem cell, are easy to isolate, culture, and manipulate in ex vivo culture. These cells have great plasticity and potential for therapeutic application, but their properties are poorly understood because of their low frequency and the lack of knowledge on cell surface markers and their location of origin. The present study was designed to address the undefined lineage relationship of hematopoietic and mesenchymal stem cells. Genetically marked, highly purified hematopoietic stem cells (HSCs) were transplanted into wild-type animals and, after bone marrow repopulation, the progeny were rigorously investigated for differentiation potential into mesenchymal tissues by analyzing in vitro differentiation into mesenchymal tissues. None/very little of the hematopoietic cells contributed to colony-forming units fibroblast activity and mesenchymal cell differentiation; however, unfractionated bone marrow cells resulted in extensive replacement of not only hematopoietic cells but also mesenchymal cells, including MSCs. As a result, we concluded that purified HSCs have no significant potency to differentiate into mesenchymal lineage. The data strongly suggest that hematopoietic cells and mesenchymal lineage cells are derived from individual lineage-specific stem cells. In addition, we succeeded in visualizing mesenchymal lineage cells using in vivo microimaging and immunohistochemistry. Flow cytometric analysis revealed CD140b (PDGFRβ) could be a specific marker for mesenchymal lineage cells. The results may reinforce the urgent need for a more comprehensive view of the mesenchymal stem cell identity and characteristics.

Disclosure of potential conflicts of interest is found at the end of this article.
Effects of Culture Conditions and Bone Morphogenetic Protein 2 on Extent of Chondrogenesis from Human Embryonic Stem Cells
Authors: Toh Wei Seong , Yang Zheng , Liu Hua , Heng Boon Chin , Lee Eng Hin , Cao Tong
Published: January 2007

The study of human embryonic stem cells (hESCs) can provide invaluable insights into the development of numerous human cell and tissue types in vitro. In this study, we addressed the potential of hESCs to undergo chondrogenesis and demonstrated the potential of hESC-derived embryoid bodies (EBs) to undergo a well-defined full-span chondrogenesis from chondrogenic induction to hypertrophic maturation. We compared chondrogenic differentiation of hESCs through EB direct-plating outgrowth system and EB-derived high-density micromass systems under defined serumfree chondrogenic conditions and demonstrated that cell-tocell contact and bone morphogenetic protein 2 (BMP2) treatment enhanced chondrocyte differentiation, resulting in the formation of cartilaginous matrix rich in collagens and proteoglycans. Provision of a high-density three-dimensional (3D) microenvironment at the beginning of differentiation is critical in driving chondrogenesis because increasing EB seeding numbers in the EB-outgrowth system was unable to enhance chondrogenesis. Temporal order of chondrogenic differentiation and hypertrophic maturation indicated by the gene expression profiles of Col 1, Col 2, and Col 10, and the deposition of extracellular matrix (ECM) proteins, proteoglycans, and collagen II and X demonstrated that the in vivo progression of chondrocyte maturation is recapitulated in the hESC-derived EB model system established in this study. Furthermore, we also showed that BMP2 can influence EB differentiation to multiple cell fates, including that of extraembryonic endodermal and mesenchymal lineages in the EB-outgrowth system, but was more committed to driving the chondrogenic cell fate in the EB micromass system. Overall, our findings provide a potential 3D model system using hESCs to delineate gene function in lineage commitment and restriction of chondrogenesis during embryonic cartilage development.

Disclosure of potential conflicts of interest is found at the end of this article.
A Population of Myogenic Stem Cells That Survives Skeletal Muscle Aging
Authors: Collins Charlotte A. , Zammit Peter S. , Ruiz Ana Pérez , Morgan Jennifer E. , Partridge Terence A.
Published: January 2007

Age-related decline in integrity and function of differentiated adult tissues is widely attributed to reduction in number or regenerative potential of resident stem cells. The satellite cell, resident beneath the basal lamina of skeletal muscle myofibers, is the principal myogenic stem cell. Here we have explored the capacity of satellite cells within aged mouse muscle to regenerate skeletal muscle and to self-renew using isolated myofibers in tissue culture and in vivo. Satellite cells expressing Pax7 were depleted from aged muscles, and when aged myofibers were placed in culture, satellite cell myogenic progression resulted in apoptosis and fewer total differentiated progeny. However, a minority of cultured aged satellite cells generated large clusters of progeny containing both differentiated cells and new cells of a quiescent satellite-cell-like phenotype characteristic of self-renewal. Parallel in vivo engraftment assays showed that, despite the reduction in Pax7+ cells, the satellite cell population associated with individual aged myofibers could regenerate muscle and self-renew as effectively as the larger population of satellite cells associated with young myofibers. We conclude that a minority of satellite cells is responsible for adult muscle regeneration, and that these stem cells survive the effects of aging to retain their intrinsic potential throughout life. Thus, the effectiveness of stem-cell-mediated muscle regeneration is determined by both extrinsic environmental influences and diversity in intrinsic potential of the stem cells themselves.

Disclosure of potential conflicts of interest is found at the end of this article.
Long-Term Culture of Postnatal Mouse Hepatic Stem/Progenitor Cells and Their Relative Developmental Hierarchy
Authors: Tsuchiya Atsunori , Heike Toshio , Baba Shiro , Fujino Hisanori , Umeda Katsutsugu , Matsuda Yasunobu , Nomoto Minoru , Ichida Takafumi , Aoyagi Yutaka , Nakahata Tatsutoshi
Published: January 2007

Few studies on the long-term culture of postnatal mouse hepatic stem/progenitor cells have been reported. We successfully adapted a serum-free culture system that we employed previously to expand fetal mouse hepatic stem/progenitor cells and maintained them in culture over long periods. The expanded postnatal cells contained immature α-fetoprotein-positive cells along with hepatocytic and cholangiocytic lineage-committed cells. These cells expressed CD49f but not CD45, CD34, Thy-1, c-kit, CD31, or flk-1, and oncostatin M induced their differentiation. This heterogeneous population contained side population (SP) cells, which express the ATP-binding cassette transporter ABCG2, and sca-1+ cells. As mice aged, the frequency of SP and sca-1+ cells decreased along with the ability of cultured cells to expand. Approximately 20%–40% of the SP cells expressed sca-1, but only a few sca-1+ cells were also SP cells. Analysis of colonies derived from single SP or sca-1+ cells revealed that, although both cells had dual differentiation potential and self-renewal ability, SP cells formed colonies more efficiently and gave rise to SP and sca-1+ cells, whereas sca-1+ cells generated only sca-1+ progeny. Thus, SP cells are more characteristic of stem cells than are sca-1+ cells. In regenerating livers, ABCG2+ cells and sca-1+ cells were detected around or in the portal area (the putative hepatic stem cell niche). The expanded cells share many features of fetal hepatic stem/progenitor cells or oval cells and may be useful in determining the mechanisms whereby hepatic stem cells self-renew and differentiate.

Disclosure of potential conflicts of interest is found at the end of this article.
Concise Review: Regulation of Embryonic Stem Cell Lineage Commitment by Mitogen-Activated Protein Kinases
Authors: Binétruy Bernard , Heasley Lynn , Bost Frédéric , Caron Leslie , Aouadi Myriam
Published: January 2007

Embryonic stem (ES) cells can give rise, in vivo, to the ectodermal, endodermal, and mesodermal germ layers and, in vitro, can differentiate into multiple cell lineages, offering broad perspectives in regenerative medicine. Understanding the molecular mechanisms governing ES cell commitment is an essential challenge in this field. The mitogen-activated protein kinase (MAPK) pathways extracellular signal-regulated kinase (ERK), c-Jun amino-terminal kinase (JNK), and p38MAPK are able to regulate ES commitment from early steps of the process to mature differentiated cells. Whereas the ERK pathway inhibits the self-renewal of ES cells, upon commitment this pathway is involved in the development of extraembryonic tissues, in early mesoderm differentiation, and in the formation of mature adipocytes; p38MAPK displays a large spectrum of action from neurons to adipocytes, and JNK is involved in both ectoderm and primitive endoderm differentiations. Furthermore, for a given pathway, several of these effects are isoform-dependent, revealing the complexity of the cellular response to activation of MAPK pathways. Regarding tissue regeneration, the potential outcome of systematic analysis of the function of different MAPKs in different ES cell differentiation programs is discussed.

Disclosure of potential conflicts of interest is found at the end of this article.
Association of a serotonin receptor 2A gene polymorphism with cognitive functions in patients with schizophrenia
Authors: Üçok Alp , Alpsan Hale , Çakır Sibel , Saruhan‐Direskeneli Güher
Published: January 2007

The aim of this study was to investigate the association between the T102C polymorphism on the 5HT2A gene and cognitive function as well as clinical manifestations in patients with schizophrenia. Eighty‐two outpatients with schizophrenia participated in this study. The Brief Psychiatric Rating Scale (BPRS) was used to assess the severity of each patient's symptoms. In order to evaluate their short‐term attention capacity, a Digit Span Test was used. The Continuous Performance Test (CPT) was used to test the sustained attention span of each of the subjects. Cognitive flexibility was measured with the Wisconsin Card Sorting Test (WCST). The polymorphism of the 5‐HT2A gene at codon 102 (T/C) was genotyped by sequence specific polymerase chain reaction. The T allele at codon 102 correlated with a lower hit rate and more commission errors in the CPT and patients with the heterogeneous genotype (TC) had more commission errors than those who were of homogeneous type (CC or TT). Patients with the TC genotype also had significantly fewer correct responses in the WCST compared to those who were type CC or TT. No relationship was found to exist between the C allele and cognitive variables. There was also no relationship established between the codon 102 polymorphism and clinical parameters. These findings suggest that the TC genotype might be related to certain cognitive impairments in patients with schizophrenia. © 2007 Wiley‐Liss, Inc.
The influence of four serotonin‐related genes on decision‐making in suicide attempters
Authors: Jollant Fabrice , Buresi Catherine , Guillaume Sébastien , Jaussent Isabelle , Bellivier Frank , Leboyer Marion , Castelnau Didier , Malafosse Alain , Courtet Philippe
Published: January 2007

Genetic factors have been associated with the vulnerability to suicidal behavior. We previously reported decision‐making impairment in suicide attempters and hypothesized that these cognitive alterations may represent an endophenotype of suicidal behavior. In this study, we aimed to investigate the influence of four serotonin‐related genes relevant to suicidal behavior on decision‐making, in a large population of suicide attempters. The Iowa Gambling Task was used to assess decision‐making in 168 patients with a personal history of attempted suicide. Patients were genotyped for four serotonergic polymorphisms: 5HTTLPR, TPH1 A218C, MAOA u‐VNTR, and TPH2 rs1118997. Patients carrying the 5HTTLPR‐ll and ‐sl, TPH1‐CC and ‐AC, MAOA‐HH (in women) and TPH2‐AA genotypes significantly improved their performance during the task, suggesting a genetic modulation of the learning process required for advantageous decision‐making. In contrast, genotypes previously associated with a higher risk of suicidal behavior, a greater sensitivity to the environment and a higher propensity to negative feelings are those conferring poorer learning abilities. We hypothesize that the influence of genetic factors on the vulnerability to suicidal behavior may partly be achieved through their modulation of decision‐making and particularly its learning component. © 2007 Wiley‐Liss, Inc.
Titelbild: Acid Initiation of Ammonia–Borane Dehydrogenation for Hydrogen Storage (Angew. Chem. 5/2007)
Authors: Stephens Frances H. , Baker R. Tom , Matus Myrna H. , Grant Daniel J. , Dixon David A.
Published: January 2007

Wasserstoff bewegt die Welt als Fahrzeugtreibstoff, der kohlenstoffneutrale und partikelfreie Abgase erzeugt. Doch wegen seiner geringen Dichte kann er nur in begrenzter Menge mitgeführt werden. In der Zuschrift auf S. 760 ff. nutzen R. T. Baker, D. A. Dixon und Mitarbeiter daher den Ammoniak‐Boran‐Komplex (H3NBH3) als Wasserstoffspeicher, dessen Wasserstoffanteil (19.6 Gew.‐%) denjenigen von Benzin übertrifft. Sie beschreiben den Mechanismus der säureinitiierten Dehydropolymerisation von H3NBH3, der mit experimentellen Methoden und Rechnungen ermittelt wurde.
Study and improvement of the conditions for production of a novel alkali stable catalase
Authors: Hua Zhaozhe , Yan Guoliang , Du Guocheng , Chen Jian
Published: January 2007

Catalase (CAT) is an enzyme capable of catalyzing the conversion of H2O2 to O2 and H2O. It has recently acquired interest due to its attractive potential application in the textile industries. In a previous study, a bacterium with slight halophilic and alkaliphilic characteristics, Bacillus sp. F26, was isolated and found to produce high‐level alkaline CAT. In the present study, the effects of culture conditions on the CAT production were investigated. The results showed that the highest activity of CAT (13.9 U/mg protein) was obtained when glucose (15 g/L) was used as carbon source. The utilization of the mixture of corn steep liquid and beef extract stimulated both bacterial growth and CAT synthesis. The highest biomass (4.5 g/L) and activity of CAT (16.5 U/mg protein) were found synchronously when 10 g/L corn steep liquid and 10 g/L beef extract were used as nitrogen source. The addition of H2O2 as an oxidative stress was used to enhance CAT production in the flasks. It was found that the activity of CAT was increased by 51.3–22.8 U/mg protein compared with the control when 2 mmol/L H2O2 was added at later exponential phases (16 h), although the cell growth was significantly inhibited. Based on the above, an exponential H2O2 feed strategy was developed, in which the feed rate of H2O2 was controlled according to specific cell growth rate (μ). In this way, the maximum CAT production (29.9 U/mL) was obtained, which was 92.8 and 20.7% higher than that in batch and constant rate fed‐batch fermentation, respectively.
Wax removal for accelerated cotton scouring with alkaline pectinase
Authors: Agrawal Pramod B. , Nierstrasz Vincent A. , Klug‐Santner Barbara G. , Gübitz Georg M. , Lenting Herman B. M. , Warmoeskerken Marijn M. C. G.
Published: January 2007

A rational approach has been applied to design a new environmentally acceptable and industrially viable enzymatic scouring process. Owing to the substrate specificity, the selection of enzymes depends on the structure and composition of the substrate, i.e. cotton fibre. The structure and composition of the outer layers of cotton fibre has been established on the basis of thorough literature study, which identifies wax and pectin removal to be the key steps for successful scouring process. Three main issues are discussed here, i.e. benchmarking of the existing alkaline scouring process, an evaluation of several selected acidic and alkaline pectinases for scouring, and the effect of wax removal treatment on pectinase performance. It has been found that the pectinolytic capability of alkaline pectinases on cotton pectin is nearly 75% higher than that of acidic pectinases. It is concluded that an efficient wax removal prior to pectinase treatment indeed results in improved performance in terms of hydrophilicity and pectin removal. To evaluate the hydrophilicity, the structural contact angle (θ) was measured using an auto‐porosimeter.
Faecal incontinence
Authors: Chatoor D R , Taylor S J , Cohen C R G , Emmanuel A V
Published: January 2007

Background

Faecal incontinence is a life style-limiting condition with multiple aetiologies. Surgical cure is not often possible.

Methods and results

A review of the literature was undertaken using Medline, Cochrane database and standard textbooks. Advanced imaging techniques now inform the treatment algorithm and objectively assess success. The long-term outcome of anal surgery is uncertain. Modern approaches favour conservative measures, such as biofeedback, and less invasive surgical procedures. Stoma formation is a definitive option for some patients.

Conclusion

Current treatment of faecal incontinence is evolving from a sphincter-focused view to a more holistic one, recognizing the influence of the pelvic floor and psyche in maintaining continence. Modern imaging modalities direct treatment strategies.
Renal protection by delayed ischaemic preconditioning is associated with inhibition of the inflammatory response and NF‐κB activation
Authors: Jiang Su Hua , Liu Chun Feng , Zhang Xiao Li , Xu Xun Hui , Zou Jian Zhou , Fang Yi , Ding Xiao Qiang
Published: January 2007

Brief and sublethal ischaemia renders an organ tolerant to subsequent prolonged ischaemia, which is called ischaemic preconditioning (IPC). In regard to the beneficial effects and endogenous mechanisms of renal delayed IPC, few data are available. In this study, we aim at determining reno‐protective effects of delayed IPC against ischaemia‐reperfusion (I/R) injury, and illustrating whether these effects are associated with suppressing inflammation and nuclear factor‐κB (NF‐κB) activation. I/R injury was induced by clamping both renal pedicles for 40 min, followed by 24 h of reperfusion. The rats were subjected to ischaemia for 20 min (preconditioning) or sham surgery (non‐ preconditioning) at day 4 before I/R. Functional and morphological parameters were evaluated at 24 h after reperfusion. At the same time, macrophage (ED‐1+) infiltration, and the expression of intercellular adhesion molecule‐1 (ICAM‐1) and tumor necrosis factor‐α (TNF‐α) were assessed by immunohistochemistry. Moreover, IκB‐α degradation and NF‐κB/DNA binding activity were analyzed. Compared with rats exposed to I/R injury, preconditioned rats had a significant decrease in levels of serum creatinine (Scr, 384.3 ± 21.8 µmol/L vs. 52.5 ± 21.7 µmol/L; p < 0.001), blood urea nitrogen (BUN, 40.4 ± 2.7 mmol/L vs. 15.9 ± 4.2 mmol/L; p < 0.001) and serum aspartate aminotransferase (AST, 486.7 ± 58.6 IU/L vs. 267.3 ± 43.9 IU/L; p < 0.001). Parallel to the above changes, preconditioned rats preserved structural integrity and decreased tubulointerstitial damage scores (3.4 ± 0.3 vs. 0.2 ± 0.05; p < 0.001) and ED‐1+ cell infiltration (25.3 ± 3.5 vs. 6.2 ± 1.2 cells/HPF, p < 0.01). Furthermore, our results showed that the expression of ICAM‐1 and TNF‐α, the degree of IκB‐α degradation, and NF‐κB/DNA binding activity were reduced by IPC. Taken together, our results demonstrated that delayed IPC offered both functional and histological protection, which may be related to suppression of inflammation in preconditioned kidneys. Copyright © 2007 John Wiley & Sons, Ltd.
Hydrogen‐Atom Transfer in Open‐Shell Organometallic Chemistry: The Reactivity of RhII(cod) and IrII(cod) Radicals
Authors: Hetterscheid Dennis G. H. , Klop Martijn , Kicken Reinout J. N. A. M. , Smits Jan M. M. , Reijerse Eduard J. , de Bruin Bas
Published: January 2007

A series of new metalloradical rhodium and iridium complexes [MII(cod)(N‐ligand)]2+ in the uncommon oxidation state +II were synthesized by one‐electron oxidation of their [MI(cod)(N‐ligand)]+ precursors (M=Rh, Ir; cod=(Z,Z)‐1,5‐cyclooctadiene; and N‐ligand is a podal bis(pyridyl)amine ligand: N,N‐bis(2‐pyridylmethyl)amine (dpa), N‐(2‐pyridylmethyl)‐N‐(6‐methyl‐2‐pyridylmethyl)amine (pla), or N‐benzyl‐N,N‐bis(6‐methyl‐2‐pyridylmethyl)amine (Bn‐dla). EPR spectroscopy, X‐ray diffraction, and DFT calculations reveal that each of these [MII(cod)(N‐ligand)]2+ species adopts a square‐pyramidal geometry with the two cod double bonds and the two pyridine fragments in the basal plane and the Namine donor at the apical position. The unpaired electron of these species mainly resides at the metal center, but the apical Namine donor also carries a considerable fraction of the total spin density (15–18 %). Density functional calculations proved a valuable tool for the analysis and simulation of the experimental EPR spectra. Whereas the MII(olefin) complexes are quite stable as solids, in solution they spontaneously transform into a 1:1 mixture of MIII(allyl) species and protonated MI(olefin) complexes (in the forms [MI(olefin)(protonated N‐ligand)]2+ for M=Rh and [MIII(H)(olefin)(N‐ligand)]2+ for M=Ir). Similar reactions were observed for the related propene complex [MII(propene)(Me2tpa)]2+ (Me2tpa=N,N,N‐tris(6‐methyl‐2‐pyridylmethyl)amine). The decomposition rate of the [MII(cod)(N‐ligand)]2+ species decreases with increasing N‐ligand bulk in the following order: dpa>pla>Bn‐dla. Decomposition of the most hindered [MII(cod)(Bn‐dla)]2+ complexes proceeds by a second‐order process. The kinetic rate expression v=kobs[MII]2 in acetone with kobs=k′[H+][S], where [S] is the concentration of additional coordinating reagents (MeCN), is in agreement with ligand‐assisted dissociation of one of the pyridine donors. Solvent coordination results in formation of more open, reactive species. Protonation of the noncoordinating pyridyl group increases the concentration of this species, and thus [H+] appears in the kinetic rate expression. The kinetic data are in agreement with bimolecular hydrogen‐atom transfer from MII(cod) to another MII species (ΔH≠=11.5±2 kcal mol−1, ΔS≠=−27±10 cal K−1 mol−1, and Δ${G{{{\ne}\hfill \atop 298\>{\rm K}\hfill}}}$=19.5±5 kcal mol−1).
New Branched DNA Constructs
Authors: Chandra Madhavaiah , Keller Sascha , Gloeckner Christian , Bornemann Benjamin , Marx Andreas
Published: January 2007

The Watson–Crick base pairing of DNA is an advantageous phenomenon that can be exploited when using DNA as a scaffold for directed self‐organization of nanometer‐sized objects. Several reports have appeared in the literature that describe the generation of branched DNA (bDNA) with variable numbers of arms that self‐assembles into predesigned architectures. These bDNA units are generated by using cleverly designed rigid crossover DNA molecules. Alternatively, bDNA can be generated by using synthetic branch points derived from either nucleoside or non‐nucleoside building blocks. Branched DNA has scarcely been explored for use in nanotechnology or from self‐assembling perspectives. Herein, we wish to report our results for the synthesis, characterization, and assembling properties of asymmetrical bDNA molecules that are able to generate linear and circular bDNA constructs. Our strategy for the generation of bDNA is based on a branching point that makes use of a novel protecting‐group strategy. The bDNA units were generated by means of automated DNA synthesis methods and were used to generate novel objects by employing chemical and biological techniques. The entities generated might be useful building blocks for DNA‐based nanobiotechnology.