bluuebunny/crossref_metadata_2025 huggingface dataset:
A sensitive method for the detection and quantification of ginkgo flavonols from plasma
Authors: Zhao Yang , Wang Li , Bao Yuanwu , Li Chuan
Published: February 2007

Extracts from Ginkgo biloba leaves (family Ginkgoaceae) have antioxidant and free radical scavenging effects, largely attributed to the flavonols, which are a major class of functional components in ginkgo extracts. In order to facilitate analysis of systemic exposure to ginkgo‐derived products in animals and/or humans, we developed a liquid chromatography/tandem mass spectrometry (LC/MS/MS)‐based method that is capable of routinely monitoring plasma levels of ginkgo flavonols. We used an initial acidic hydrolysis step to convert the plasma ginkgo flavonol conjugates into their aglycone forms [quercetin (QCT), kaempferol (KMF) and isorhamnetin (ISR)] prior to EtOAc‐based extraction and subsequent LC/MS/MS‐based analysis. Comparative studies showed that the use of a mobile phase containing an extremely low concentration of HCOOH (0.01‰) dramatically improved the electrospray ionization efficiency of the analytes in the negative ion mode; the efficiencies were ∼4‐, ∼8‐ and ∼20‐fold higher for QCT, KMF and ISR, respectively, versus the results obtained using an electrolyte‐free mobile phase, or ∼2‐, ∼3‐ and ∼4‐fold higher, respectively, versus the results obtained using a mobile phase containing the more commonly utilized concentration of HCOOH (1‰). In addition, use of the low concentration of HCOOH also decreased undesired matrix effects. These favorable effects have been referred to as ‘LC‐electrolyte effects’. Due to structural differences in the B‐ring substituent, different types of precursor‐to‐product ion pairs (m/z 301 → 151 for QCT, 285 → 187 for KMF, and 315 → 300 for ISR) were used for the selected reaction monitoring of the analytes. In addition, the chromatographic conditions were optimized on the basis of an initial scouting of matrix effects on analyte ionization. Despite the absence of an internal standard, the validation results consistently demonstrated that our bioassay is valid, reproducible, and reliable. The newly developed assay provided lower limits of quantification of 1.3, 1.3 and 0.4 pg on‐column for QCT, KMF and ISR, respectively, which is more sensitive than any previously reported method for determining ginkgo flavonols. Finally, the assay suitability was demonstrated in a pilot pharmacokinetic measurement of a pharmaceutical ginkgo product in a beagle dog. This newly developed method should prove useful for wide‐scale monitoring of ginkgo flavonol plasma concentrations for both pharmaceutical investigations and clinical applications. Copyright © 2007 John Wiley & Sons, Ltd.
Pharmacokinetic study of intraperitoneally administered troglitazone in mice using ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: New Lee‐Sun , Saha Sudipta , Ong Michie M. K. , Boelsterli Urs Alex , Chan Eric C. Y.
Published: February 2007

A rapid and sensitive ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method was developed and validated for the determination of troglitazone in mouse plasma. Troglitazone and its internal standard (IS), rosiglitazone, were separated on an ACQUITY UPLC BEH C18 column (1.7 µm particle size, 50 × 2.1 mm i.d.) by gradient elution with water and methanol at a flow rate of 0.5 mL/min. The cycle time of each analysis was 2.5 min. Rosiglitazone and troglitazone eluted at 1.13 and 1.57 min, respectively, and were chromatographically resolved from the ion suppression and enhancement zones due to the biological matrix effect. Quantitation of the analytes was performed in electrospray negative ionization mode (ESI −ve) using multiple reaction monitoring (MRM) experiments. The weighted (1/x) calibration curve was quadratic over the plasma concentration range 1–2500 ng/mL with a correlation coefficient (r2) of 0.9966. The limit of quantitation (LOQ) of troglitazone in mouse plasma was lower than 1 ng/mL. The inter‐ and intra‐day variations of the assay were lower than 12.1%; the overall accuracy ranged from 86.4–110.2% and recovery from spiked plasma was more than 60%. The developed method was successfully applied to determine troglitazone in mouse plasma after intraperitoneal administration. Copyright © 2007 John Wiley & Sons, Ltd.
Changes in carbon and nitrogen stable isotopes of chironomid larvae during growth, starvation and metamorphosis
Authors: Doi Hideyuki , Kikuchi Eisuke , Takagi Shigeto , Shikano Shuichi
Published: February 2007

We conducted experiments to determine isotope changes in the deposit‐feeding chironomid larvae Chironomus acerbiphilus during feeding, starvation and metamorphosis. Isotope changes in chironomid larvae occurred mainly during growth and rarely afterward. This finding indicates that chironomid isotope turnover mainly occurs in conjunction with growth and suggests that chironomid larvae only break down newly assimilated food for energy during periods of no growth. Chironomid δ13C values significantly increased throughout the starvation experiment, indicating that chironomids preferentially break down components with lower δ13C content during starvation. We found significant changes in chironomid isotope ratios (15N enrichment) during pupation. This evidence suggests that the physiological condition of animals (such as during an active growth phase or pre‐ or post‐molting) is important to their stable isotope ratios. Copyright © 2007 John Wiley & Sons, Ltd.
Do b‐ions occur from vibrational excitation upon H‐desorption in electron capture dissociation?
Authors: Haselmann Kim F. , Schmidt Marcel
Published: February 2007

Electron capture dissociation (ECD) has recently been shown in some cases to produce abundant N‐terminal b‐ion peptide fragments. These product ions are usually only observed when activation occurs via vibrational excitation as in collision‐induced dissociation (CID). Here, we show that occurrence of b‐ions in the ECD spectra of synthetic peptides are correlated with low gas‐phase basicity and that the observed b‐ion fragments are N‐terminal products. Furthermore, all ECD spectra containing b‐ions also had abundant losses of hydrogen and ammonia from the charge‐reduced species. Copyright © 2007 John Wiley & Sons, Ltd.
Exploration of oligosaccharide‐protein interactions in glycoprotein quality control by synthetic approaches
Authors: Hagihara Shinya , Totani Kiichiro , Ito Yukishige
Published: February 2007

High‐mannose‐type oligosaccharides, which are cotranslationally introduced to nascent polypeptides, play important roles in glycoprotein quality control. This process is highly complex, involving a number of lectins, chaperones, and glycan‐processing enzymes. For example, calnexin and calreticulin (CRT) are molecular chaperones that recognize monoglucosylated forms of high‐mannose‐type glycans. UDP‐glucose : glycoprotein glucosyltransferase (UGGT) only glucosylates high‐mannose‐type glycans attached to partially folded proteins. Fbs1 is a component of ubiquitin ligase that recognizes sugar chains. Although recent studies have clarified the properties of these proteins, most of them used oligosaccharides derived from natural sources, which contain structural heterogeneity. In order to gain a more precise understanding, we started our program to comprehensively synthesize high‐mannose‐type glycans associated with a protein quality control system. Additionally, investigation of artificial glycoproteins led us to the discovery of the first nonpeptidic substrate of UGGT. These synthetic oligosaccharide probes have allowed us to conduct quantitative evaluations of the activity and specificity of CRT, Fbs1, and UGGT. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 290–302; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20088
CLV3/ESR‐related (CLE) peptides as intercellular signaling molecules in plants
Authors: Sawa Shinichiro , Kinoshita Atsuko , Nakanomyo Ikuko , Fukuda Hiroo
Published: February 2007

For many years, the plant hormones auxin, cytokinin, ethylene, gibberellin, abscisic acid, brassinosteroid, jasmonic acid, and salicylic acid have been extensively studied as key regulators of plant growth and development. However, recent biochemical and genetic analyses have revealed that secretory peptides are also responsible for intercellular signaling in plants and regulate various events including wound response, cell division control, and pollen self‐incompatibility. We discovered two natural CLAVATA3 (CLV3)/ESR‐related (CLE) peptides: tracheary elements differentiation inhibitory factor (TDIF) and CLV3, which are dodecapeptides with two hydroxyproline residues that regulate vascular development and meristem formation, respectively. This discovery enabled us to predict the chemical form of CLE gene products. In the Arabidopsis genome, there are 31 CLE genes that correspond to 26 CLE peptides. The application of all 26 chemically synthesized peptides to plants revealed the existence of distinctive functional groups. From these results, we discuss the functions of CLE peptides in plant development and plant–parasite interactions. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 303–310; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20091
Mechanism regulating cell surface expression and activation of Toll‐like receptor 4
Authors: Saitoh Shin‐Ichiroh , Miyake Kensuke
Published: February 2007

The Toll family of receptors senses microbial invasion and activates defense responses. Toll‐like receptor 4 (TLR4) is a member of the Toll family that senses lipopolysaccharide (LPS), a principal membrane component from Gram‐negative bacteria. LPS is known as an endotoxin that strongly activates immune cells such as macrophages and dendritic cells. LPS recognition by TLR4 requires an additional accessory molecule, MD‐2. MD‐2 is associated with the extracellular portion of TLR4, directly binds to LPS, and regulates subsequent LPS‐induced TLR4 clustering. LPS recognition occurs on the cell surface. The subcellular distribution of TLR was shown to influence TLR responses. An endoplasmic reticulum (ER) chaperone, glycoprotein 96, is required for the stability of TLR4 and the formation of a TLR4/MD‐2 complex in ER. MD‐2 facilitates TLR4 glycosylation and its trafficking to the cell surface. Recently, another molecule, a protein associated with Toll‐like receptor 4 (PRAT4A), was shown to play a critical role in cell surface expression of TLR4. These molecules control LPS responsiveness by regulating the subcellular distribution of TLR4. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 311–319; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20093
Interaction of amphotericin B and its selected derivatives with membranes: molecular modeling studies
Authors: Baginski Maciej , Czub Jacek , Sternal Kamil
Published: February 2007

Amphotericin B (AmB) is a well‐known antifungal antibiotic that has been used in the clinic for about five decades. Despite its chemotherapeutic importance, AmB is quite toxic and many efforts have been made to improve its pharmacological properties, e.g., by chemical modifications. The lipid membrane is a molecular target for AmB, however, due to heterogeneity of its components, the molecular mechanism of AmB action is still unclear. The lack of this knowledge hinders rational designing of new and less toxic AmB derivatives. Our review is a critical presentation of the current understanding of AmB molecular mechanism of action at the membrane level. Except the experimental approach, the extensive overview of molecular modeling studies, performed mostly in our lab, is presented. The results of interactions between AmB or some of its derivatives and lipid model membranes are discussed. In our studies, different biomembrane models and different associate states of the antibiotic were included. Presented molecular modeling approach is especially valuable with regard to a new paradigm of the structure of lipid membrane containing liquid‐ordered domains. Hopefully, all these complementary experimental/computational approaches are going to reach the point at which a new hypothesis about molecular mechanism of AmB activity and selectivity will be put forward. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 320–332; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20096
Synthesis of endotoxic principle of bacterial lipopolysaccharide and its recognition by the innate immune systems of hosts
Authors: Kusumoto Shoichi , Fukase Koichi
Published: February 2007

A new stage of endotoxin research was brought about by structure elucidation and chemical synthesis of lipid A, the lipophilic partial structure of the lipopolysaccharide (LPS) of Gram‐negative bacteria. Synthetic lipid A exhibited full endotoxic activity, which gave unequivocal evidence for the concept that lipid A is the active entity of endotoxin. Various lipid A analogues, as well as their radiolabeled derivatives and more complex partial structures of LPS, were also synthesized. By the use of these synthetic homogeneous preparations, not only simple studies on structure–activity relationships but precise and detailed analyses became possible on how this typical bacterial component is recognized by the innate immune receptor complex of mammalian cells. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 333–343; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20098
Bioorganic studies on plant movement, from natural products to its receptor
Authors: Shoji Mitsuru , Kato Eisuke , Nakamura Yoko , Fujii Tomohiko , Manabe Yoshiyuki , Ueda Minoru
Published: February 2007

The chemical aspects of the circadian leaf movement known as “nyctinasty” are discussed in this paper. Each of the nyctinastic plants of five different genera so far examined contained a pair of factors, one of which induced leaf closure and another induced leaf opening. The relative contents of the closing and opening factors changed correlating with the nyctinastic leaf movement. The use of fluorescence‐labeled and photoaffinity‐labeled factors revealed that the factors bind to specific cells, the motor cells, present in the pulvini, and that the membrane fraction of the motor cells contained two proteins of 210 and 180 kDa, which can bind to the factors. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 344–355; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20102
Effects of rubberized flooring on Asian elephant behavior in captivity
Authors: Meller Camie L. , Croney Candace C. , Shepherdson David
Published: February 2007

Six Asian elephants at the Oregon Zoo were observed to determine the effects of a poured rubber flooring substrate on captive Asian elephant behavior. Room utilization also was evaluated in seven rooms used for indoor housing, including Front and Back observation areas. Data were collected in three phases. Phase I (Baseline Phase) examined elephant behavior on old concrete floors. In Phase II (Choice Phase), elephant behavior was observed in the Back observation area where room sizes were comparable and when a choice of flooring substrates was available. Phase III (Final Phase) examined elephant behavior when all rooms in both observation areas, Front and Back, were converted to rubberized flooring. Room use in both observation areas remained stable throughout the study, suggesting that flooring substrate did not affect room use choice. However, there was a clear pattern of decreased discomfort behaviors on the new rubber flooring. Normal locomotion as well as stereotypic locomotion increased on the new rubber flooring. In addition, resting behavior changed to more closely reflect the resting behavior of wild elephants, which typically sleep standing up, and spend very little time in lateral recumbence. Overall, these findings suggest that the rubber flooring may have provided a more comfortable surface for locomotion as well as standing resting behavior. It is suggested that poured rubber flooring may be a beneficial addition to similar animal facilities. Zoo Biol 0:1–11, 2007. © 2007 Wiley‐Liss, Inc.
Packing for Control of Hemorrhage in Major Liver Trauma
Authors: Nicol A. J. , Hommes M. , Primrose R. , Navsaria P. H. , Krige J. E. J.
Published: February 2007

Background

Packing for complex liver injuries has been associated with an increased risk of abdominal sepsis and bile leaks. The aim of the present study was to determine the optimum timing of pack removal and to assess whether the total duration of packing increases the incidence of these complications.

Methods

The study was based on a retrospective review of all patients requiring liver packing over an 8‐year period in a level 1 trauma center.

Results

Ninety‐three (17%) of 534 liver injuries identified at laparotomy required perihepatic packing. Penetrating and blunt trauma occurred in 72 (77%) and 21 (23%), respectively. The mean total duration of packing was 2.4 days (range: 0.5–6.0 days). There was no association between the total duration of packing and the development of liver‐related complications (P = 0.284) or septic complications (P = 0.155). Early removal of packs at 24 h was associated with a higher rate of re‐bleeding than removal of packs at 48 h (P = 0.006).

Conclusions

The total duration of liver packing does not result in an increase in septic complications or bile leaks. The first re‐look laparotomy should only be performed after 48 h. An early re‐look at 24 h is associated with re‐bleeding and does not lead to early removal of liver packs.
Factors Predicting Postoperative Infectious Complications and Early Induction of Inflammatory Mediators in Ulcerative Colitis Patients
Authors: Miki Chikao , Ohmori Yukinari , Yoshiyama Shigeyuki , Toiyama Yuji , Araki Toshimitsu , Uchida Keiichi , Kusunoki Masato
Published: February 2007

Background

Positive outcomes after restorative proctocolectomy are compromised by a number of specific septic complications. However, there is no useful perioperative marker predicting postoperative infectious complications (PICs) in steroid overdosed patients with ulcerative colitis (UC).

Methods

To determine factors associated with PICs and their relation to circulating levels of pro‐ and anti‐inflammatory cytokines and neutrophil elastase (NE), we obtained perioperative blood samples from 60 UC patients.

Results

Postoperative infectious complications were identified in 47% of cases. Patients who developed PICs had significantly longer disease duration, had been administered a greater total preoperative dosage of prednisolone, and had a higher body mass index. Logistic regression analysis showed that the total preoperative dosage of prednisolone was independently associated with the development of PICs. These patients showed suppressed systemic inflammation and pro‐ and anti‐inflammatory cytokine induction. An early increase in the NE level was found to be predictive of PICs in the high‐dose group, whereas there was no significant difference in neutrophil counts between the high‐ and low‐dose groups.

Conclusions

Circulating NE levels in the early postoperative period might be a useful predictor of PICs in immune‐controlled UC patients who received high doses of steroids.
Recurrence after Total Thyroidectomy for Benign Multinodular Goiter
Authors: Snook Kylie L. , Stalberg Peter L. H. , Sidhu Stan B. , Sywak Mark S. , Edhouse Pamela , Delbridge Leigh
Published: February 2007

Background

Total thyroidectomy is now the preferred option for the management of benign multinodular goiter (BMNG), and it ought not be associated with recurrent disease. The aim of the present study was to examine the efficacy of total thyroidectomy for BMNG and to review reasons for recurrence.

Material and methods

The study group comprised all patients from January 1980 to December 2005 who underwent a definitive procedure to remove all thyroid tissue for BMNG, and who were subsequently identified as having developed a recurrence. Included were patients who underwent primary total thyroidectomy at our unit, or a two or more stage procedure where a definitive secondary total thyroidectomy was performed at our unit.

Results

There were 3,044 total or secondary total thyroidectomies performed for BMNG during the study period. Ten patients were identified as having developed recurrent BMNG requiring reoperation despite previous complete “total” thyroidectomy. There were 11 sites of recurrence in 10 patients. Only one was a true local recurrence in the thyroid bed. Another 9 recurrences related to the embryology of the thyroid gland, 4 in the pyramidal tract and 5 in the thyrothymic tract. There was one recurrence at another site (submandibular) in a patient with presumed metastatic thyroid cancer despite benign histology. There were no complications in any of the 10 patients.

Conclusions

Total thyroidectomy for BMNG is not only a safe procedure but is efficacious in preventing recurrent disease. Failure to remove embryological remnants such as thyrothymic residue or pyramidal remnants during total thyroidectomy is the major cause of recurrence.
Outcomes of Hepatectomy for Hepatolithiasis
Authors: Lee Tung‐Yen , Chen Yao‐Li , Chang Hung‐Chi , Chan Chien‐Pin , Kuo Shou‐Jen
Published: February 2007

Aim

Surgical and nonsurgical procedures for management of hepatolithiasis have been reported. The aim of this study was to evaluate immediate and long‐term results of hepatectomy as treatment for hepatolithiasis.

Materials and Methods

Immediate and long‐term outcomes of 123 consecutive patients who underwent hepatectomy for hepatolithiasis at our institution from 2000 to 2005 were analyzed retrospectively. Acute cholangitis was the major presenting symptom (in 106 out of 123, 86.2% of cases).

Results

The immediate stone clearance rate was 92.7% (114 out of 123) and final stone clearance rate was 96% (118 out of 123) after subsequent T‐tube route or endoscopic retrograde cholangiopancreatography (ERCP). Residual stones were identified in 5 patients (4%). The surgical morbidity and mortality rates were 33.3% (41 out of 123) and 1.6% (2 out of 123) respectively. Of the 123 patients, 3 (2.4%) had associated cholangiocarcinoma at the time of hepatectomy. With a median follow‐up of 40.3 months (range 5–58), a recurrent stone developed in 7 patients (5.7%) and cholangiocarcinoma in 2 (1.6%). Ten patients died during the follow‐up period, with 4 of them (out of 123, 3.2%) due to recurrent stone with sepsis.

Conclusion

Hepatectomy is a safe and effective treatment for hepatolithiasis, with a high stone clearance rate and fair rate of surgical complications. Recurrent stone‐induced sepsis and cholangiocarcinoma are the major factors compromising long‐term survival in these patients.
Endoscopic Thyroidectomy Using a New Bilateral Axillo‐Breast Approach
Authors: Choe Jun‐Ho , Kim Seok Won , Chung Ki‐Wook , Park Kyoung Sik , Han Wonshik , Noh Dong‐Young , Oh Seung Keun , Youn Yeo‐Kyu
Published: February 2007

Introduction

Endoscopic techniques have recently been applied in thyroid surgery using cervical, axillary, and breast approaches. We modified the axillo‐bilateral breast approach (ABBA) and developed the bilateral axillo‐breast approach (BABA) to obtain optimal visualization for total thyroidectomy.

Methods

We used two 12‐mm ports through bilateral circumareolar incisions for flexible videoscopy and Harmonic scalpel and two 5‐mm ports through both axillae for graspers and dissectors. Thyroidectomy was performed under full visualization of the superior and inferior thyroidal arteries, parathyroid glands, and recurrent laryngeal nerves.

Results

After performing 25 ABBA endoscopic thyroid surgeries, we developed BABA and performed 110 operations using this method. The BABA operations included 52 total thyroidectomies, 2 near‐total thyroidectomies, 8 subtotal thyroidectomies, 43 lobectomies, and 3 subtotal lobectomies. Pathology revealed 41 benign lesions and 69 cancers. Mean operation time was 165.3 ± 43.5 minutes. There were 2 cases of conversion to open surgery, 1 due to cancer with capsular invasion and the other due to tracheal injury. Nine postoperative complications developed: transient unilateral vocal cord palsy in 4 cases, transient hypocalcemia in 4 cases, and postoperative infection in 1 case. The 2‐month postoperative thyroglobulin level was less than 1 ng/ml in all examined cases of total thyroidectomy. Cosmetic results were excellent.

Conclusions

The BABA technique for endoscopic thyroid surgery is a feasible method of total thyroidectomy with a low rate of postoperative complications and, additionally, excellent cosmetic results. Therefore, in selected cases of thyroid cancer, the BABA endoscopic total thyroidectomy should be considered as a valid surgical option.
Role of Biomarkers in Developing New Therapies for Vascular Disease
Authors: Nambi Vijay , Ballantyne Christie M.
Published: February 2007

Background

The use of biomarkers has been among the advances that have helped in the better medical management of patients. Biomarkers such as total cholesterol, low‐density lipoprotein cholesterol, and hemoglobin A1c are used routinely. Advances in technologies, proteomics, and genomics and the resultant improved understanding of the pathophysiology of vascular diseases have led to the identification of several promising biomarkers. These biomarkers may be used to identify specific populations that may benefit from therapies, as surrogate markers of clinical efficacy, or as targets of therapy.
Surgical Options in Undifferentiated Thyroid Carcinoma
Authors: Lang Brian Hung‐Hin , Lo Chung‐Yau
Published: February 2007

Undifferentiated or anaplastic carcinoma is an uncommon histologic type of thyroid cancer. It is one of the most aggressive malignancies associated with a poor prognosis. Most patients are elderly presenting as locally advanced disease with nodal and distant metastases. Complete surgical resection is frequently not possible and there is no effective systemic therapy. Aggressive multimodal therapy including surgery, radiation, and chemotherapy is recommended for management. However, because of the rarity of the disease, its aggressiveness and the lack of prospective treatment protocols, nearly all evidence in the literature comes from retrospective case series or cohort studies for selected patients’ subgroups treated over a relatively long study period. Evidence of therapeutic benefit of one treatment option over another is lacking. Prognosis remains dismal with a median survival of 2–12 months Surgery remains an important component of the multimodal therapy and is commonly adopted as primary treatment. Although radical resection should be discouraged, resection without inducing significant morbidity can be considered for good risk patients with resectable tumors. It provides an effective form of palliation with potential cure when combined with postoperative radiotherapy and/or chemotherapy. Patients selected for surgical resection was frequently identified to have improved survival. A regime of preoperative hyperfractionated radiotherapy and doxorubicin followed by surgery when feasible has been documented to achieve local control and avoid tracheostomy for ATC patients. Because of the ineffectiveness of all conventional treatment modalities, novel molecular targeted therapies are being developed to tackling this uniformly fatal disease with promising results.
African American adolescent mothers and grandmothers: A multigenerational approach to parenting
Authors: Oberlander Sarah E. , Black Maureen M. , Starr Raymond H.
Published: February 2007

This study is an adaptation and extension of Apfel and Seitz's (Family Relations, 40(4), 421–429, 1991) models of adolescent parenting and adolescent‐grandmother relationships to a sample of 148 African American, first‐time adolescent mothers and their 6‐month‐old infants. The Parental Supplemental model, in which adolescent mothers and grandmothers shared caregiving, described 63% of Apfel and Seitz's (1991) sample and 66% of the current sample. Shared caregiving was not associated with conflict in the adolescent mother–grandmother relationship. Adolescent mothers who had caregiving responsibilities and a supportive adolescent‐grandmother relationship also reported competence in their parenting role. Findings provide support for Apfel and Seitz's Parental Apprentice model, in which young mothers gain competence through direct caregiving experience in the context of a supportive relationship.
Community‐driven learning activities, creating futures: 30,000 people can't be wrong—Can they?
Authors: Dowrick Peter W.
Published: February 2007

A major vehicle for the practice of community psychology is through the organization of community‐based activities. My colleagues and I have developed many programs for community learning centers, in‐school and after school programs, and community technology centers. In the last 10 years, 30,000 people (mostly children) have participated in activities designed for enjoyment and learning, with a view to adding protective factors and reducing negative factors in at‐risk communities. Development of these programs for literacy, education, life and work skills, has increasingly followed a community responsive model. Within each program, we created explicit images of future success. That is, people could see themselves being successful where they normally fail: self modeling with feedforward. Data reports show that individuals generalized and maintained their new skills and attitudes, but the sustainability of programs has been variable. Analysis of the variations indicates the importance of program level feedforward that brings the future into the present. The discussion includes consideration of how individual‐level and community‐level practices can inform each other.
Exploring the Complexities of Familism and Acculturation: Central Constructs for People of Mexican Origin
Authors: Rodriguez Norma , Mira Consuelo Bingham , Paez Nancy Denise , Myers Hector F.
Published: February 2007

We examined the relationships between three dimensions of familism: importance of family, family support, and family conflict with acculturation, assessed orthogonally (Mexican and American cultural contributions assessed independently), and the relative contribution these factors make to psychological adjustment among 248 (124 women, 124 men) adults of Mexican origin. After controlling for sociodemographic characteristics, positive associations were found between importance of family and the biculturalism of Mexican and American cultural identity; family support and Mexican cultural identity; but no associations between family conflict and level of acculturation. Psychological well‐being was positively associated with Mexican cultural identity and family support, whereas psychological distress was associated with greater family conflict and lower family support. The greater relative contribution of Mexican cultural identity to familism and well‐being, and the importance of assessing acculturation orthogonally are discussed.
Social support, sense of community in school, and self‐efficacy as resources during early adolescence: an integrative model
Authors: Vieno Alessio , Santinello Massimo , Pastore Massimiliano , Perkins Douglas D.
Published: February 2007

Influences of different sources of social support (from parents and friends), school sense of community, and self‐efficacy on psychosocial well being (as measured by self‐reported life satisfaction and psychological symptoms) in early adolescence were investigated in an integrative model. The model was tested using structural equation modeling. Multi‐group comparisons were used to estimate differences between sex and age groups. The survey sample was composed of 7,097 students in Northern Italy (51.4% male) divided into three age cohorts (equivalent to 6th, 8th, and 10th grades with median ages of 11, 13, and 15). Findings obtained using SEM were consistent with self‐efficacy and school sense of community mediating effects of social support on psychosocial adjustment. The multi‐group comparison indicates a need for more complex developmental models and more research on how changing forms of support interact with each other as their effects also change during this important stage of the life. Implications for primary prevention and cross‐cultural comparisons are discussed.
Community types and mental health: a multilevel study of local environmental stress and coping
Authors: Dupéré Véronique , Perkins Douglas D.
Published: February 2007

Research has found that neighborhood structural characteristics can influence residents' mental health. Few studies, however, have explored the proximal reasons behind such influences. This study investigates how different types of communities, in terms of environmental stressors (social and physical disorder and fear of crime) and social resources (informal ties and formal organizational participation), affect well‐being, depression, and anxiety in adult residents. Data are from a survey of 412 residents nested in 50 street blocks. Block stressors and resources were cluster analyzed to identify six block types. After controlling for several individual‐ and block‐level characteristics, results from multilevel models suggest that in communities facing relatively few stressors, higher levels of formal participation are associated with better mental health. Because high levels of formal participation were not found in communities with higher levels of stressors, the impact of participation in such contexts could not be examined. However, results suggest that in communities where stressors are more common, isolation from neighbors may have a protective effect on mental health.
Self-assembly of micelles into designed networks
Authors: Yuan Yong J , Pyatenko Alexander T , Suzuki Masaaki
Published: February 2007

The EO20PO70EO20(molecular weight 5800) amphiphile as a template is to form dispersed micelle structures. Silver nanoparticles, as inorganic precursors synthesized by a laser ablation method in pure water, are able to produce the highly ordered vesicles detected by TEM micrography. The thickness of the outer layer of a micelle, formed by the silver nanoparticles interacting preferentially with the more hydrophilic EO20block, was around 3.5 nm. The vesicular structure ensembled from micelles is due to proceeding to the mixture of cubic and hexagonal phases.
Anti‐angiogenic properties of myo‐inositol trispyrophosphate in ovo and growth reduction of implanted glioma
Authors: Sihn Gabin , Walter Thomas , Klein Jean-Claude , Queguiner Isabelle , Iwao Hiroshi , Nicolau Claude , Lehn Jean-Marie , Corvol Pierre , Gasc Jean-Marie
Published: February 2007

We investigate here the anti‐angiogenic properties of the synthetic compound myo‐inositol trispyrophosphate (ITPP). By increasing oxy‐haemoglobin dissociation, ITPP has the potential to counteract the effects of hypoxia, a critical regulator of angiogenesis and cancer progression. ITPP inhibited angiogenesis of the chorioallantoic membrane (CAM), as analyzed with an original program dedicated to automated quantification of angiogenesis in this model. ITPP also markedly reduced tumor progression and angiogenesis in an experimental model of U87 glioma cell nodules grafted onto the CAM. These results point out the potential of ITPP for the development of a new class of anti‐angiogenic and anti‐cancer compounds.
Mechanisms of COPII vesicle formation and protein sorting
Authors: Sato Ken , Nakano Akihiko
Published: February 2007

The evolutionarily conserved coat protein complex II (COPII) generates transport vesicles that mediate protein transport from the endoplasmic reticulum (ER). COPII coat is responsible for direct capture of cargo proteins and for the physical deformation of the ER membrane that drives the COPII vesicle formation. In addition to coat proteins, recent data have indicated that the Ras‐like small GTPase Sar1 plays multiple roles, such as COPII coat recruitment, cargo sorting, and completion of the final fission. In the present review, we summarize current knowledge of COPII‐mediated vesicle formation from the ER, as well as highlighting non‐canonical roles of COPII components.
Intermittent fasting prevents the progression of type I diabetic nephropathy in rats and changes the expression of Sir2 and p53
Authors: Tikoo Kulbhushan , Tripathi Durga Nand , Kabra Dhiraj G. , Sharma Vikram , Gaikwad Anil Bhanudas
Published: February 2007

Diabetic nephropathy (DN) is one of the main causes of end stage renal disease (ESRD) and a leading cause of diabetes mellitus related morbidity and mortality. Recently, sirtuin are reported to have emerging pathogenetic roles in cancer, muscle differentiation, heart failure, neurodegeneration, diabetes and aging. The aim of the present study was to study the role of intermittent fasting (IF) on DN and studying the expression of Sir2 and p53. At biochemical level, we found that IF causes significant improvement in blood urea nitrogen (BUN), creatinine, albumin and HDL cholesterol, parameters that are associated with the development of DN. Diabetic rats on IF also show significant improvement in onset of hypertension. Interestingly, the expression of Sir2, a NAD dependent histone deacetylase, decreases in diabetic rat kidney and this decrease is overcome by IF. Moreover, we provide evidence for involvement of mitogen activated protein kinases (MAPK) cascade in mediating the effects of IF as there is reduction in the expression of p38 which gets induced under diabetic condition. This was further accompanied by the concomitant decrease in cleavage of caspase3 and p53 expression. These findings suggest that IF significantly improves biochemical parameters associated with development of DN and changes the expression of Sir2 and p53.
Effect of magnesium ions on the thermal stability of human poly(A)‐specific ribonuclease
Authors: Liu Wei-Feng , Zhang Ao , Cheng Yuan , Zhou Hai-Meng , Yan Yong-Bin
Published: February 2007

Poly(A)‐specific ribonuclease (PARN), a member of the DEDD family, is a key enzyme involved in the deadenylation of mRNA in higher eukaryotic cells. In this research, it was found that Mg2+ could protect PARN against thermal inactivation by increasing the midpoint of inactivation and decreasing the inactivation rate. This protective effect was unique to Mg2+ in a concentration‐dependent manner. However, the thermal unfolding and aggregation was promoted by the addition of Mg2+ at high temperatures. These results revealed that Mg2+ might have dual effects on PARN stability: protecting the active site but endangering the overall structural stability.
Retained introns increase putative microRNA targets within 3′ UTRs of human mRNA
Authors: Tan Sheng , Guo Jiaming , Huang Qianli , Chen Xueping , Li-Ling Jesse , Li Qingwei , Ma Fei
Published: February 2007

MicroRNAs (miRNAs) are a class of non‐coding RNA that post‐transcriptionally regulates the expression of target genes by binding to mRNAs. As one form of alternative splicing, intron retention has influence upon mRNA modification and protein encoding. The effect of miRNA on mRNA containing retained intron within 3′ UTR, however, has not been systematically elucidated. Here, we examined a total of 2864 human genes which contain at least one retained intron from the MAASE and ASD databases and found 387 genes having contained retained introns within 3′ UTR. The effect of retained introns upon miRNA targets was explored with three web‐based programs for miRNA prediction including miRanda, TargetScanS and PicTar. The results showed that retained introns can increase putative miRNA targets in human mRNA. Retained introns have higher chances than other regions of 3′ UTR in involving the site of miRNAs targets of most genes which contain putative miRNA targets within it. Furthermore, some transcripts contain miRNA targets solely because of the retained introns in 3′ UTR. In addition, we examined those ‘Ignored’ retained introns by miRanda software and the results indicated that miRNAs may contain many more putative targets.
Cooling of aPr<1 fluid in a rectangular container
Authors: LIN WENXIAN , ARMFIELD S. W. , PATTERSON JOHN C.
Published: February 2007

The flow behaviour associated with the cooling of an initially quiescent isothermal Newtonian fluid with Prandtl numberPrless than unity in a rectangular container by unsteady natural convection with an imposed lower temperature on vertical sidewalls is investigated by scaling analysis and direct numerical simulation. The flow is dominated by two distinct stages of development. i.e the boundary-layer development stage adjacent to the sidewall and the subsequent cooling-down stage. The first stage can be further divided into a start-up stage, transitional stage, and steady-state stage. The parameters characterizing the flow behaviour are the boundary-layer thickness, the maximum vertical velocity within the boundary layer, the time for the boundary layer to reach the steady state, the Nusselt number across the sidewall at the boundary-layer development stage, the time for the fluid in the container to be fully cooled down, and the average fluid temperature over the whole volume of the container.
Spatial signatures of retrograde spanwise vortices in wall turbulence
Authors: NATRAJAN V. K. , WU Y. , CHRISTENSEN K. T.
Published: February 2007

The spatial signatures of retrograde spanwise vortices in wall turbulence are assessed from particle-image velocimetry measurements in the streamwise–wall-normal plane of a zero-pressure-gradient turbulent boundary layer at Reτ≡u*δ/ν=2350. The present results suggest that a proportion of retrograde spanwise vortices have a well-defined spatial relationship with neighbouring prograde vortices. Two-point cross-correlations and conditionally averaged velocity fields given a retrograde vortex reveal that such structures are typically oriented either upstream of and below or downstream of and above a prograde core. While these pairings are consistent with the typical-eddy patterns reported by Falco and co-workers, we offer an alternative interpretation for a proportion of these retrograde/prograde pairs. In particular, the arrangement of a retrograde spanwise vortex upstream of and below a prograde core is also consistent with the spatial signature revealed if an omega-shaped hairpin structure were sliced through its shoulder region by a fixed streamwise–wall-normal measurement plane.
Scaling and instability of a junction vortex
Authors: ALLEN J. J. , NAITOH T.
Published: February 2007

This paper details experiments in the region where an impulsively started moving wall slides under a stationary wall. The experiments were conducted over a Reynolds number range of ReΓ=5×102–5×105. The length scale for the Reynolds number is defined as the distance the wall has moved from rest and increases during an experiment. Experiments show that for ReΓ>103 a vortex forms close to the junction where the moving wall meets the stationary one. The data shows that while the vortical structure is small, in relation to the fixed-apparatus length scale, the size of the vortex normalized with respect to the wall speed and viscosity scales in a universal fashion with respect to ReΓ. The scaling rate is proportional to t5/6 when the Reynolds number is large. The kinematic behaviour of the vortex is related to the impulse that the moving wall applies to the fluid and results in a prediction that the transient structure should grow as t5/6 and the velocity field should scale as t−1/6. The spatial-growth prediction is in good agreement with the experimental results and the velocity scaling is moderately successful in collapsing the experimental data.

For ReΓ>2×104 three-dimensional instabilities appear on the perimeter of the vortical structure and the flow transitions from an unsteady two-dimensional flow to a strongly three-dimensional vortical structure at ReΓ≃ 4 × 104. The instability mechanism is centrifugal. The formation and growth of these instability structures and their ingestion into the primary vortex core causes the three-dimensional breakdown of the primary vortex. Two movies are available with the online version of the paper.
Non-dispersive and weakly dispersive single-layer flow over an axisymmetric obstacle: the equivalent aerofoil formulation
Authors: ESLER J. G. , RUMP O. J. , JOHNSON E. R.
Published: February 2007

Non-dispersive and weakly dispersive single-layer flows over axisymmetric obstacles, of non-dimensional height M measured relative to the layer depth, are investigated. The case of transcritical flow, for which the Froude number F of the oncoming flow is close to unity, and that of supercritical flow, for which F > 1, are considered. For transcritical flow, a similarity theory is developed for small obstacle height and, for non-dispersive flow, the problem is shown to be isomorphic to that of the transonic flow of a compressible gas over a thin aerofoil. The non-dimensional drag exerted by the obstacle on the flow takes the form D(Γ) M5/3, where Γ = (F-1)M−2/3 is a transcritical similarity parameter and D is a function which depends on the shape of the ‘equivalent aerofoil’ specific to the obstacle. The theory is verified numerically by comparing results from a shock-capturing shallow-water model with corresponding solutions of the transonic small-disturbance equation, and is found to be generally accurate for M≲0.4 and |Γ| ≲ 1. In weakly dispersive flow the equivalent aerofoil becomes the boundary condition for the Kadomtsev–Petviashvili equation and (multiple) solitary waves replace hydraulic jumps in the resulting flow patterns.

For Γ ≳ 1.5 the transcritical similarity theory is found to be inaccurate and, for small M, flow patterns are well described by a supercritical theory, in which the flow is determined by the linear solution near the obstacle. In this regime the drag is shown to be $c_d M^2/(F\sqrt{F^2-1})$, where cd is a constant dependent on the obstacle shape. Away from the obstacle, in non-dispersive flow the far-field behaviour is known to be described by the N-wave theory of Whitham and in dispersive flow by the Korteweg–de Vries equation. In the latter case the number of emergent solitary waves in the wake is shown to be a function of ${\cal A}= 3M/(2\delta^2 \sqrt{F^2-1})$, where δ is the ratio of the undisturbed layer depth to the radial scale of the obstacle.