bluuebunny/crossref_metadata_2025 huggingface dataset:
Bilateral Risk for Subsequent Breast Cancer After Lobular Carcinoma-In-Situ: Analysis of Surveillance, Epidemiology, and End Results Data
Authors: Chuba Paul J. , Hamre Merlin R. , Yap Johnny , Severson Richard K. , Lucas David , Shamsa Falah , Aref Amr
Published: August 2005

Purpose

Noninvasive lesions involving the lobules of the breast are increasingly diagnosed as incidental microscopic findings at the time of lumpectomy or core-needle biopsy. We investigated the incidence rates of invasive breast cancer (IBC) after a diagnosis of lobular carcinoma-in-situ (LCIS) by using Surveillance, Epidemiology, and End Results (SEER) data.

Patients and Methods

Patients (N = 4,853) having a diagnosis of primary LCIS in the time period of 1973 to 1998 were identified using the SEER Public Use CD-ROM data. The database was then searched for patients with subsequent primary IBC occurrences (n = 350). The clinical and pathologic characteristics of patients with subsequent primary IBCs were compared with the characteristics of patients with primary IBCs attained during the same time period (N = 255,114).

Results

The incidence of IBC increased over time from diagnosis of LCIS, with 7.1% ± 0.5% incidence of IBC at 10 years. IBCs detected after partial mastectomy occurred in either breast (46% ipsilateral and 54% contralateral); however, after mastectomy, most IBCs were contralateral (94.7%). IBCs occurring after LCIS more often represented invasive lobular histology (23.1%) compared with primary IBCs (6.5%). The standardized incidence ratio (the ratio of observed to expected cases) for developing IBC was 2.4 (95% CI, 2.1 to 2.6) adjusted for age and year of diagnosis.

Conclusion

LCIS is associated with increased risk of subsequent invasive disease, with equal predisposition in either breast. The minimum risk of developing IBC after LCIS is 7.1% at 10 years.
Determination of TP53 Mutation Is More Relevant Than Microsatellite Instability Status for the Prediction of Disease-Free Survival in Adjuvant-Treated Stage III Colon Cancer Patients
Authors: Westra Jantine L. , Schaapveld Michael , Hollema Harry , de Boer Jelle P. , Kraak Marian M.J. , de Jong Debora , ter Elst Arja , Mulder Nanno H. , Buys Charles H.C.M. , Hofstra Robert M.W. , Plukker John T.M.
Published: August 2005

Purpose

Microsatellite instability (MSI), TP53 mutation, and KRAS mutation status have been reported as prognostic factors in colon cancer. Most studies, however, have included heterogeneous groups of patients with respect to cancer stage. We determined the prognostic relevance of high-frequency MSI (MSI-H), TP53 mutations, and KRAS mutations in a well-defined group of patients with stage III colon cancer (N = 391), randomly assigned for adjuvant treatment with fluorouracil-based chemotherapy.

Methods

Three hundred ninety-one tumor specimens were available. MSI was determined in 273 specimens, and mutation analyses of TP53 and KRAS were performed in 220 and 205 specimens, respectively.

Results

In a univariate analysis, MSI-H (44 of 273; 16%) was associated with a longer disease-free survival (DFS; P = .038), but in a multivariate model adjusting for nodal involvement, histology, invasion, and grade of tumor, the association of MSI status with DFS did no longer reach statistical significance, though the risk estimate for microsatellite stability versus MSI-H tumors did not change much. Mutant TP53, found in 116 (53%) of 220 tumors, was associated with a shorter DFS, both in univariate (P = .009) and multivariate analyses (P = .018), whereas KRAS mutations (58 of 205; 28%) did not show any prognostic significance.

Conclusion

Both mutant TP53 and MSI-H seem to be prognostic indicators for disease-free survival, but only TP53 retains statistical significance after adjusting for clinical heterogeneity. Thus, in adjuvantly treated patients with stage III colon cancer, presence or absence of a TP53 mutation should be considered as a better predictor for DFS than MSI status.
Ecteinascidin-743 (ET-743) for Chemotherapy-Naive Patients With Advanced Soft Tissue Sarcomas: Multicenter Phase II and Pharmacokinetic Study
Authors: Garcia-Carbonero R. , Supko J.G. , Maki R.G. , Manola J. , Ryan D.P. , Harmon D. , Puchalski T.A. , Goss G. , Seiden M.V. , Waxman A. , Quigley M.T. , Lopez T. , Sancho M.A. , Jimeno J. , Guzman C. , Demetri G.D.
Published: August 2005

Purpose

To evaluate the response rate, toxicity profile, and pharmacokinetics of ecteinascidin-743 (ET-743) as first-line therapy in patients with unresectable advanced soft tissue sarcoma (STS).

Patients and Methods

Thirty-six patients with STS were enrolled onto the study between September 1999 and August 2000. Patients were treated with 1.5 mg/m2 of ET-743 given as a 24-hour continuous intravenous (IV) infusion every 21 days. Pharmacokinetic sampling was performed in 23 patients.

Results

One complete and five partial responses were achieved in 35 assessable patients for an overall response rate of 17.1% (95% CI, 6.6% to 33.6%). In addition, one patient had a minor response, leading to an overall clinical benefit of 20%. Neutropenia and transaminitis were the main grade 3 to 4 toxicities, which occurred in 33% and 36% of the patients. The estimated 1-year progression-free and overall survival rates were 21% (95% CI, 11% to 41%) and 72% (95% CI, 59% to 88%), respectively. Total body clearance (L/h) was not significantly correlated with body-surface area (r = −0.28; P = .21). Mild hepatic impairment or the extent of prior cytotoxic therapy does not seem to contribute significantly to the high interpatient variability (49%) in the clearance of this drug. Severity of treatment-related toxicity was not correlated with pharmacokinetic variables.

Conclusion

ET-743 demonstrates clinical activity as first-line therapy against STS with acceptable toxicity. Additional studies to establish empirical dosing guidelines may be necessary to improve the safety of the drug in patients with varying degrees of hepatic dysfunction and definitively establish the role of ET-743 for patients with these malignancies.
Sequential Regimen of Chemotherapy, Reduced-Intensity Conditioning for Allogeneic Stem-Cell Transplantation, and Prophylactic Donor Lymphocyte Transfusion in High-Risk Acute Myeloid Leukemia and Myelodysplastic Syndrome
Authors: Schmid Christoph , Schleuning Michael , Ledderose Georg , Tischer Johanna , Kolb Hans-Jochem
Published: August 2005

Purpose

To improve the effect of allogeneic stem-cell transplantation by sequential use of intensive chemotherapy, reduced-intensity conditioning (RIC), and prophylactic donor lymphocyte transfusions (pDLTs) in high-risk acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

Patients and Methods

In a prospective study of 75 consecutive patients (median age, 52.3 years), high risk was defined by progressive or refractory disease (n = 59), second remission after early relapse (n = 8), or first remission with poor prognosis based on cytogenetics or delayed response to induction therapy (n = 8). Unfavorable karyotypes were found in 49% of informative patients, and 68 patients had medical contraindications against standard conditioning. Fludarabine (30 mg/m2), cytarabine (2 g/m2), and amsacrine (100 mg/m2) for 4 days were used for cytoreduction. After 3 days of rest, RIC consisted of 4 Gy total-body irradiation, antithymocyte globulin, and 80 to 120 mg/kg cyclophosphamide. Thirty-one patients had an HLA-identical sibling donor; 44 patients had an unrelated and/or HLA-mismatched donor. pDLT was given from day +120 in patients who were not receiving immunosuppression and were free of graft-versus-host disease (GvHD).

Results

Complete remission was induced in 66 patients (88%). With a median follow-up of 35.1 months (range, 13.6 to 47.6 months), 2-year overall and leukemia-free survival were 42% and 40%, respectively. Outcome of patients with refractory disease or with complex cytogenetic aberrations was identical to that of better prognostic subgroups. Survival was best in patients who received high CD34+ cell numbers, and in patients with limited GvHD.

Conclusion

Sequential use of intensive chemotherapy, RIC transplantation, and pDLT represents a promising approach to the treatment of high-risk AML and MDS, particularly in patients with most unfavorable prognoses.
Multicenter, Randomized Phase II Trial of Oral CI-1033 for Previously Treated Advanced Ovarian Cancer
Authors: Campos Susana , Hamid Oday , Seiden Michael V. , Oza Amit , Plante Marie , Potkul Ronald K. , Lenehan Peter F. , Kaldjian Eric P. , Varterasian Mary L. , Jordan Cheryl , Charbonneau Claudie , Hirte Hal
Published: August 2005

Purpose

To evaluate the antitumor activity and toxicity of two doses of CI-1033 in patients with platinum-refractory or recurrent ovarian cancer, and to determine baseline expression of epidermal growth factor receptor in tumor cells.

Patients and Methods

This phase II, open-label clinical trial evaluated CI-1033 in patients with ovarian cancer who failed prior platinum-based therapy. Two oral doses of CI-1033 were evaluated—a 50-mg and a 200-mg oral dose administered daily for 21 days in a 28-day cycle. Patients were evaluated for tumor response and toxicity; in addition, archival baseline tumor samples were analyzed by immunohistochemistry for erbB1 to erbB4 status.

Results

One hundred five eligible patients were treated. Baseline demographic characteristics were balanced in this heavily pretreated patient population. The median number of prior chemotherapy regimens received was four. The most commonly encountered drug-related adverse events for both dose arms were gastrointestinal (diarrhea, nausea, stomatitis) toxicity, asthenia, and rash. No responses were observed. Stable disease was confirmed in 34% and 26% of patients in the 200-mg and 50-mg arms, respectively, and 1-year survival rates were 38.5% and 37.7%, respectively. Baseline erbB3 and erbB4 revealed the highest frequencies of expression, while erbB2 was the lowest.

Conclusion

CI-1033 did not show activity in unscreened patients with advanced ovarian cancer. At 50 mg/d, CI-1033 had a more favorable adverse events profile than at 200 mg/d. erbB3 and erbB4 receptors showed the highest expression in tumor samples while erbB2 revealed the least. There appears to be no association between baseline erbB expression and disease stability.
Phase II Study of Gefitinib, Fluorouracil, Leucovorin, and Oxaliplatin Therapy in Previously Treated Patients With Metastatic Colorectal Cancer
Authors: Kuo Timothy , Cho Cheryl D. , Halsey Joanne , Wakelee Heather A. , Advani Ranjana H. , Ford James M. , Fisher George A. , Sikic Branimir I.
Published: August 2005

Purpose

To investigate the gefitinib, fluorouracil (FU), leucovorin, and oxaliplatin regimen (IFOX) in previously treated patients with metastatic colorectal cancer.

Patients and Methods

Eligible patients had stage IV colorectal adenocarcinoma and had demonstrated progression or intolerance to a prior chemotherapy regimen not including oxaliplatin. Each cycle consisted of 14 days. Cycle 1 consisted of oxaliplatin 85 mg/m2 intravenously (IV) during 2 hours on day 1, hours 0 to 2; leucovorin 200 mg/m2 IV on days 1 and 2, hours 0 to 2; FU 400 mg/m2 IV push on days 1 and 2; and FU 600 mg/m2 IV on days 1 and 2, hours 2 to 24 (FOLFOX-4). All subsequent cycles consisted of FOLFOX-4 with gefitinib at 500 mg/d administered orally throughout the 14-day cycle.

Results

Twenty-seven patients were enrolled onto the study. The median number of prior chemotherapy regimens was two, and 74% of all patients received prior irinotecan. Nine of the 27 patients (33%) and six of the 20 patients (30%) who had prior FU and irinotecan had a partial response by Response Evaluation Criteria in Solid Tumors Group criteria. Median overall survival was 12.0 months. Median event-free survival was 5.4 months. Grade 3 to 4 toxicities included neutropenia (48%), diarrhea (48%), nausea (22%), and vomiting (15%).

Conclusion

IFOX is an active regimen in patients with previously treated metastatic colorectal adenocarcinoma, demonstrating higher response rates than those reported with FOLFOX-4 alone in a similar patient population.
Modeling the Cost of Management Options for Stage I Nonseminomatous Germ Cell Tumors: A Decision Tree Analysis
Authors: Link Richard E. , Allaf Mohamad E. , Pili Roberto , Kavoussi Louis R.
Published: August 2005

Purpose

Patients with clinical stage I nonseminomatous germ cell tumors (NSGCTs) have been managed with surveillance, chemotherapy, or retroperitoneal lymphadenectomy (RPLND) with similar survival outcomes. Cost factors influencing the choice of therapy were evaluated using computer-based decision analysis.

Methods

A detailed model was developed that integrates projected costs for more than 60 possible treatment outcomes. It incorporates primary, adjuvant, and salvage chemotherapy, primary and postchemotherapy RPLND, and both laparoscopic and open surgical approaches. Starting values and probabilities were derived from a comprehensive meta-analysis of the last 25 years of testes cancer literature. Hypothesis testing was performed using sensitivity analysis.

Results

The model predicts a cost premium for both primary chemotherapy (18.7%) and RPLND (51.7%) compared with surveillance. If laparoscopic RPLND was practiced, the cost premium for primary surgery (29.1%) approached that of chemotherapy (26.4%). Open RPLND was 1.25× as costly as laparoscopic RPLND, primarily because of longer hospitalization. The choice of open RPLND yielded a 6.9% cost premium for a surveillance program in this model. For such a program, primary chemotherapy became cost advantageous when the probability of recurrence during surveillance was more than 46%.

Conclusion

This model allows a variety of treatment cost hypotheses to be tested. Primary RPLND is never cost advantageous over surveillance or primary chemotherapy. Surgical costs can significantly increase the overall cost of a surveillance program. In stage I patients with high-risk tumor characteristics, primary chemotherapy may have a cost advantage over surveillance.
Initial and Late Resistance to Imatinib in Advanced Gastrointestinal Stromal Tumors Are Predicted by Different Prognostic Factors: A European Organisation for Research and Treatment of Cancer–Italian Sarcoma Group–Australasian Gastrointestinal Trials Group Study
Authors: Van Glabbeke Martine , Verweij Jaap , Casali Paolo G. , Le Cesne Axel , Hohenberger Peter , Ray-Coquard Isabelle , Schlemmer Marcus , van Oosterom Allan T. , Goldstein David , Sciot Raf , Hogendoorn Pancras C.W. , Brown Michelle , Bertulli Rossella , Judson Ian R.
Published: August 2005

Purpose

The aim of this study was to identify factors predicting initial and late resistance of GI stromal tumor (GIST) patients to imatinib and to document the dose-response relationship in the prognostic subgroups. This study is based on the European Organisation for Research and Treatment of Cancer–Italian Sarcoma Group–Australasian Gastrointestinal Trials Group randomized trial comparing two doses of imatinib in advanced disease.

Patients and Methods

Initial resistance was defined as progression within 3 months of randomization, and late resistance was defined as progression beyond 3 months. Investigated cofactors include imatinib dose, age, sex, performance status, original disease site, site and size of lesions at trial entry, and baseline hematologic and biologic parameters.

Results

Initial resistance was recorded for 116 (12%) of 934 assessable patients and was independently predicted by the presence of lung and absence of liver metastases, low hemoglobin level, and high granulocyte count. Among 818 patients who were alive and progression free at 3 months, 347 subsequent progressions were recorded, and late resistance was independently predicted by high baseline granulocyte count, primary tumor outside of the stomach, large tumor size, and low initial imatinib dose. The impact of initial dose on late resistance was mainly significant in patients with a high baseline granulocyte count (> 5.109/L) and in patients with tumors of GI origin outside of the stomach and small intestine.

Conclusion

Our study identifies patients for whom initial and/or long-term treatment needs to be improved and patients who require a high initial dose. Correlation of these results with immunohistochemistry and molecular parameters may further help to understand the biologic mechanisms of resistance.
Adenomatous Polyposis Families That Screen APC Mutation–Negative by Conventional Methods Are Genetically Heterogeneous
Authors: Renkonen Elise T. , Nieminen Pekka , Abdel-Rahman Wael M. , Moisio Anu-Liisa , Järvelä Irma , Arte Sirpa , Järvinen Heikki J. , Peltomäki Päivi
Published: August 2005

Purpose

One third of families with classical adenomatous polyposis (FAP), and a majority of those with attenuated FAP (AFAP), remain APC mutation–negative by conventional methods. Our purpose was to clarify the genetic basis of polyposis and genotype-phenotype correlations in such families.

Patients and Methods

We studied a cohort of 29 adenomatous polyposis families that had screened APC mutation–negative by the protein truncation test, heteroduplex analysis, and exon-specific sequencing. The APC gene was investigated for large genomic rearrangements by multiplex ligation-dependent probe amplification (MLPA), and for allelic mRNA expression by single nucleotide primer extension (SNuPE). The AXIN2 gene was screened for mutations by sequencing.

Results

Four families (14%) showed a constitutional deletion of the entire APC gene (three families) or a single exon (one family). Seven families (24%) revealed reduced or extinct mRNA expression from one APC allele in blood, accompanied by loss of heterozygosity in the APC region in six (75%) of eight tumors. In 15 families (52%), possible APC involvement could be neither confirmed nor excluded. Finally, as detailed elsewhere, three families (10%) had germline mutations in genes other than APC, AXIN2 in one family, and MYH in two families.

Conclusion

“APC mutation–negative” FAP is genetically heterogeneous, and a combination of MLPA and SNuPE is able to link a considerable proportion (38%) to APC. Significant differences were observed in clinical manifestations between subgroups, emphasizing the importance of accurate genetic and clinical characterization for the proper management of such families.
The geneENHANCER OF PINOIDcontrols cotyledon development in theArabidopsisembryo
Authors: Treml Birgit S. , Winderl Sabine , Radykewicz Roman , Herz Markus , Schweizer Günther , Hutzler Peter , Glawischnig Erich , Ruiz Ramón A. Torres
Published: August 2005

During Arabidopsis embryo development, cotyledon primordia are generated at transition stage from precursor cells that are not derived from the embryonic shoot apical meristem (SAM). To date, it is not known which genes specifically instruct these precursor cells to elaborate cotyledons, nor is the role of auxin in cotyledon development clear. In laternemutants, the cotyledons are precisely deleted, yet the hypocotyl and root are unaffected. The laterne phenotype is caused by a combination of two mutations: one in the PINOID (PID) gene and another mutation in a novel locus designated ENHANCER OF PINOID (ENP). The expression domains of shoot apex organising genes such as SHOOT MERISTEMLESS (STM) extend along the entire apical region of laterne embryos. However, analysis of pid enp stm triple mutants shows that ectopic activity of STM does not appear to cause cotyledon obliteration. This is exclusively caused by enp in concert with pid. In pinoid embryos, reversal of polarity of the PIN1 auxin transport facilitator in the apex is only occasional, explaining irregular auxin maxima in the cotyledon tips. By contrast, polarity of PIN1:GFP is completely reversed to basal position in the epidermal layer of the laterne embryo. Consequently auxin, which is believed to be essential for organ formation, fails to accumulate in the apex. This strongly suggests that ENP specifically regulates cotyledon development through control of PIN1 polarity in concert with PID.
Genetic and cellular analyses of zebrafish atrioventricular cushion and valve development
Authors: Beis Dimitris , Bartman Thomas , Jin Suk-Won , Scott Ian C. , D'Amico Leonard A. , Ober Elke A. , Verkade Heather , Frantsve Julie , Field Holly A. , Wehman Ann , Baier Herwig , Tallafuss Alexandra , Bally-Cuif Laure , Chen Jau-Nian , Stainier Didier Y. R. , Jungblut Benno
Published: August 2005

Defects in cardiac valve morphogenesis and septation of the heart chambers constitute some of the most common human congenital abnormalities. Some of these defects originate from errors in atrioventricular (AV) endocardial cushion development. Although this process is being extensively studied in mouse and chick, the zebrafish system presents several advantages over these models, including the ability to carry out forward genetic screens and study vertebrate gene function at the single cell level. In this paper, we analyze the cellular and subcellular architecture of the zebrafish heart during stages of AV cushion and valve development and gain an unprecedented level of resolution into this process. We find that endocardial cells in the AV canal differentiate morphologically before the onset of epithelial to mesenchymal transformation, thereby defining a previously unappreciated step during AV valve formation. We use a combination of novel transgenic lines and fluorescent immunohistochemistry to analyze further the role of various genetic (Notch and Calcineurin signaling) and epigenetic (heart function)pathways in this process. In addition, from a large-scale forward genetic screen we identified 55 mutants, defining 48 different genes, that exhibit defects in discrete stages of AV cushion development. This collection of mutants provides a unique set of tools to further our understanding of the genetic basis of cell behavior and differentiation during AV valve development.
EPHB4 regulates chemokine-evoked trophoblast responses: a mechanism for incorporating the human placenta into the maternal circulation
Authors: Red-Horse Kristy , Kapidzic Mirhan , Zhou Yan , Feng Kui-Tzu , Singh Harbindar , Fisher Susan J.
Published: August 2005

In humans, fetal cytotrophoblasts leave the placenta and enter the uterine wall, where they preferentially remodel arterioles. The fundamental mechanisms that govern these processes are largely unknown. Previously, we have shown that invasive cytotrophoblasts express several chemokines, as well as the receptors with which they interact. Here, we report that these ligand-receptor interactions stimulate cytotrophoblast migration to approximately the same level as a growth factor cocktail that includes serum. Additionally,cytotrophoblast commitment to uterine invasion was accompanied by rapid downregulation of EPHB4, a transmembrane receptor associated with venous identity, and upregulation of ephrin B1. Within the uterine wall, the cells also upregulated expression of ephrin B2, an EPH transmembrane ligand that is associated with arterial identity. In vitro cytotrophoblasts avoided EPHB4-coated substrates; upon co-culture with 3T3 cells expressing this molecule, their migration was significantly inhibited. As to the mechanisms involved, cytotrophoblast interactions with EPHB4 downregulated chemokine-induced but not growth factor-stimulated migration. We propose that EPHB4/ephrin B1 interactions generate repulsive signals that direct cytotrophoblast invasion toward the uterus, where chemokines stimulate cytotrophoblast migration through the decidua. When cytotrophoblasts encounter EPHB4 expressed by venous endothelium, ephrin B-generated repulsive signals and a reduction in chemokine-mediated responses limit their interaction with veins. When they encounter ephrin B2 ligands expressed in uterine arterioles,migration is permitted. The net effect is preferential cytotrophoblast remodeling of arterioles, a hallmark of human placentation.
Progressive divergence of definitive haematopoietic stem cells from the endothelial compartment does not depend on contact with the foetal liver
Authors: Taoudi Samir , Morrison Aline M. , Inoue Hirofumi , Gribi Ruby , Ure Janice , Medvinsky Alexander
Published: August 2005

The yolk sac and the para-aortic splanchnopleura/aorta-genital ridges-mesonephros (P-Sp/AGM) region are the main sites of haematopoietic activity in the mouse embryo at the pre-liver stage of development. By day 11.5 of gestation, the AGM region is capable of autonomous initiation and expansion of definitive haematopoietic stem cells (HSCs). By day 12.5, HSC activity in the AGM region is reduced whilst a second wave of HSCs begins to emerge in the yolk sac. We show here that HSCs emerging in both locations are marked by co-expression of the endothelial-specific marker VE-cadherin and the pan-leukocyte antigen CD45. Phenotypic characterisation using CD31, TIE2,FLK1, Ac-LDL receptors, and CD34 markers demonstrated significant similarities between this VE-cadherin+CD45+ `double-positive'population and endothelial cells suggesting a common origin for these cells. The double-positive fraction also expressed the stem cell markers Kit, Sca1 and AA4.1. Long-term transplantation experiments demonstrated that the double-positive population, which constituted less than 0.05% of the day 11.5 AGM region and the day 12.5 yolk sac, is highly enriched for HSCs. In vitro assays showed that this population is also enriched for myeloid progenitors. During foetal liver colonization, circulating HSCs remained within the VE-cadherin+ cell fraction, although their phenotypic similarity with endothelial cells became less prominent. Upon liver colonisation the majority of HSCs downregulated VE-cadherin, expression of which was completely lost in the adult bone marrow. Partial loss of VE-cadherin expression in HSCs can be observed extra hepatically in the advanced AGM region by E12.5. Similarly, the CD34+KIT+ population in the placenta,recently identified as a reservoir of HSCs, partly lose VE-cadherin expression by E12.5. By culturing isolated E11.5 AGM region and E12.5 yolk sac we show that the developmental switch from a `primary'VE-cadherin+CD45+ to a more `advanced'VE-cadherin-CD45+ phenotype does not require contact of HSCs with the liver and is probably a function of developmental time.
Hair follicle renewal: organization of stem cells in the matrix and the role of stereotyped lineages and behaviors
Authors: Legué Emilie , Nicolas Jean-François
Published: August 2005

Hair follicles (HFs) are renewed via multipotent stem cells located in a reservoir (the bulge); however, little is known about how they generate multi-tissue HFs from a proliferative zone (the matrix). To address this issue, we temporally induced clonal labeling during HF growth. Challenging the prevailing hypothesis, we found that the matrix contains restricted self-renewing stem cells for each inner structure. These cells are located around the dermal papilla forming a germinative layer. They occupy different proximodistal sectors and produce differentiated cells along the matrix radial axis via stereotyped lineages and cell behavior. By contrast, the outer layer of HFs displays a mode of growth involving apoptosis that coordinates the development of outer and inner structures. HF morphology is therefore determined by the organization of cell fates along the proximodistal axis and by cell behavior along the radial (lateral) axis in the matrix. Thus, our studies suggest that fate and behavior are organized by two systems(uncoupled), and this uncoupling may represent a fundamental way to simplify morphogenesis.
Proximodistal identity during vertebrate limb regeneration is regulated by Meis homeodomain proteins
Authors: Mercader Nadia , Tanaka Elly M. , Torres Miguel
Published: August 2005

The mechanisms by which cells obtain instructions to precisely re-create the missing parts of an organ remain an unresolved question in regenerative biology. Urodele limb regeneration is a powerful model in which to study these mechanisms. Following limb amputation, blastema cells interpret the proximal-most positional identity in the stump to reproduce missing parts faithfully. Classical experiments showed the ability of retinoic acid (RA) to proximalize blastema positional values. Meis homeobox genes are involved in RA-dependent specification of proximal cell identity during limb development. To understand the molecular basis for specifying proximal positional identities during regeneration, we isolated the axolotl Meis homeobox family. Axolotl Meis genes are RA-regulated during both regeneration and embryonic limb development. During limb regeneration, Meis overexpression relocates distal blastema cells to more proximal locations, whereas Meis knockdown inhibits RA proximalization of limb blastemas. Meis genes are thus crucial targets of RA proximalizing activity on blastema cells.
Genetic and epigenetic properties of mouse male germline stem cells during long-term culture
Authors: Kanatsu-Shinohara Mito , Ogonuki Narumi , Iwano Tomohiko , Lee Jiyoung , Kazuki Yasuhiro , Inoue Kimiko , Miki Hiromi , Takehashi Masanori , Toyokuni Shinya , Shinkai Yoichi , Oshimura Mitsuo , Ishino Fumitoshi , Ogura Atsuo , Shinohara Takashi
Published: August 2005

Although stem cells are believed to divide infinitely by self-renewal division, there is little evidence that demonstrates their infinite replicative potential. Spermatogonial stem cells are the founder cell population for spermatogenesis. Recently, in vitro culture of spermatogonial stem cells was described. Spermatogonial stem cells can be expanded in vitro in the presence of glial cell line-derived neurotrophic factor (GDNF),maintaining the capacity to produce spermatogenesis after transplantation into testis. Here, we examined the stability and proliferative capacity of spermatogonial stem cells using cultured cells. Spermatogonial stem cells were cultured over 2 years and achieved ∼1085-fold expansion. Unlike other germline cells that often acquire genetic and epigenetic changes in vitro, spermatogonial stem cells retained the euploid karyotype and androgenetic imprint during the 2-year experimental period, and produced normal spermatogenesis and fertile offspring. However, the telomeres in spermatogonial stem cells gradually shortened during culture, suggesting that they are not immortal. Nevertheless, the remarkable stability and proliferative potential of spermatogonial stem cells suggest that they have a unique machinery to prevent transmission of genetic and epigenetic damages to the offspring, and these characteristics make them an attractive target for germline modification.
Carbonic anhydrase in the adult mosquito midgut
Authors: del Pilar Corena Maria , VanEkeris Leslie , Salazar Ma. Isabel , Bowers Doria , Fiedler Molly M. , Silverman David , Tu Chingkuang , Linser Paul J.
Published: August 2005

We have previously demonstrated the involvement of carbonic anhydrase (CA)in larval mosquito midgut physiology. In this study, we used Hansson's histochemistry to examine the distribution of the enzyme in the midgut of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, Culex nigripalpus, Ochlerotatus taeniorhynchus, Anopheles albimanus and Anopheles quadrimaculatus adult mosquitoes. Additionally, we quantitated CA content in the anterior and posterior midgut of adult males and females from these species using the 18O isotope exchange method coupled to mass spectrometry. We also tested the effect of CA inhibitors such as methazolamide and acetazolamide in the alkalization of the midgut in females from these species. Our results indicate that CA is present in the midgut of adults from the species studied and that it appears to be preferentially associated with the posterior midgut in both males and females. CA inhibitors appear to have a profound effect on midgut pH indicating that this enzyme might play a key role in the maintenance of this pH.
Performance of guinea fowlNumida meleagrisduring jumping requires storage and release of elastic energy
Authors: Henry Havalee T. , Ellerby David J. , Marsh Richard L.
Published: August 2005

The ability of birds to perform effective jumps may play an important role in predator avoidance and flight initiation. Jumping can provide the vertical acceleration necessary for a rapid takeoff, which may be particularly important for ground-dwelling birds such as phasianids. We hypothesized that by making use of elastic energy storage and release, the leg muscles could provide the large power outputs needed for achieving high velocities after takeoff. We investigated the performance of the leg muscles of the guinea fowl Numida meleagris during jumping using kinematic and force-plate analyses. Comparison of the methods indicated that in this species the wings did not supply energy to power takeoff and thus all the work and power came from the leg muscles. Guinea fowl produced a peak vertical force of 5.3 times body weight. Despite having lower muscle-mass-specific power output in comparison to more specialized jumpers, guinea fowl demonstrated surprisingly good performance by producing muscle-mass-specific work outputs of 45 J kg–1, a value approximately two thirds of the maximal expected value for skeletal muscle. The muscle-mass-specific peak power output during jumping was nearly 800 W kg–1, which is more than twice the peak isotonic power estimated for guinea fowl leg muscles. To account for high power outputs, we concluded that energy has to be stored early in the jumps and released later during peak power production, presumably using mechanisms similar to those found in more specialized jumpers.
Cranial kinesis in palaeognathous birds
Authors: Gussekloo Sander W. S. , Bout Ron G.
Published: August 2005

Cranial kinesis in birds is induced by muscles located caudal on the cranium. These forces are transferred onto the moveable parts of the skull via the Pterygoid–Palatinum Complex (PPC). This bony structure therefore plays an essential role in cranial kinesis. In palaeognathous birds the morphology of the PPC is remarkably different from that of neognathous birds and is thought to be related to the specific type of cranial kinesis in palaeognaths known as central rhynchokinesis. We determined whether clear bending zones as found in neognaths are present in the upper bill of paleognaths, and measured bending forces opposing elevation of the upper bill. A static force model was used to calculate the opening forces that can be produced by some of the palaeognathous species. We found that no clear bending zones are present in the upper bill, and bending is expected to occur over the whole length of the upper bill. Muscle forces are more than sufficient to overcome bending forces and to elevate the upper bill. The resistance against bending by the bony elements alone is very low, which might indicate that bending of bony elements can occur during food handling when muscles are not used to stabilise the upper bill. Model calculations suggest that the large processi basipterygoidei play a role in stabilizing the skull elements, when birds have to resist external opening forces on the upper bill as might occur during tearing leafs from plants. We conclude that the specific morphology of the palaeognathous upper bill and PPC are not designed for active cranial kinesis, but are adapted to resist external forces that might cause unwanted elevation of the upper bill during feeding.
The kinematics of feeding and drinking in palaeognathous birds in relation to cranial morphology
Authors: Gussekloo Sander W. S. , Bout Ron G.
Published: August 2005

Cranial kinesis is an important feature in avian feeding behaviour and involves the transmission of quadrate movement to the upper bill by the Pterygoid–Palatinum Complex (PPC). The PPC in Palaeognathae is remarkably different from that found in Neognathae. In this study we analyse whether the special morphology of the PPC is an adaptation to the feeding behaviour of the Palaeognathae. Behavioural analyses of the rhea Rhea americana showed that the feeding behaviour of the rhea is typical `Catch and Throw' behaviour, independent of the size of the food item. Drinking is achieved by a scooping movement followed by a low-amplitude tip-up phase. During feeding rhynchokinetic movements of the upper bill were observed. However, cranial kinesis was limited and may differ from rhynchokinesis in neognathes as a clear bending zone seemed absent. Since the movement patterns are considered very similar to the basic feeding behaviour in neognathous birds it is concluded that the specific morphology of the PPC is not the result of specific functional demands from palaeognathous feeding behaviour.
Mechanisms underlying the production of carapace vibrations and associated waterborne sounds in the American lobster,Homarus americanus
Authors: Henninger Heidi Pye , Watson Winsor H.
Published: August 2005

American lobsters produce carapace vibrations, which also lead to waterborne acoustic signals, by simultaneously contracting the antagonistic remotor and promotor muscles located at the base of the second antenna. These vibrations have a mean frequency of 183.1 Hz (range 87–261 Hz), range in duration from 68 to 1720 ms (mean 277.1 ms) and lead to waterborne sounds of similar frequencies. Lobsters most often produce these signals using only one pair of muscles at a time and alternate between the muscles of the left and right antennae when making a series of vibrations. Occasionally, they vibrate their carapace by simultaneously contracting both sets of muscles. While the remotor muscle is required for producing carapace vibrations, the promotor appears to play a secondary role. Electrical stimulation of the remotor, but not the promotor, results in the production of vibrations, while lesions of the remotor, but not promotor, eliminate the ability of lobsters to vibrate their carapace. Lobsters of all sizes and both sexes produce these signals when startled, grasped or threatened. However, at this time, the behavioral significance of vibration and/or sound production by American lobsters is not known.
Hind limb proportions and kinematics: are small primates different from other small mammals?
Authors: Schmidt Manuela
Published: August 2005

Similar in body size, locomotor behaviour and morphology to the last common ancestor of Primates, living small quadrupedal primates provide a convenient model for investigating the evolution of primate locomotion. In this study,the hind limb kinematics of quadrupedal walking in mouse lemurs, brown lemurs,cotton-top tamarins and squirrel monkeys are analysed using cineradiography. The scaling of hind limb length to body size and the intralimb proportions of the three-segmented hind limb are taken into consideration when kinematic similarities and differences are discussed.

Hind limb kinematics of arboreal quadrupedal primates, ranging in size between 100 g and 3000 g, are size independent and resemble the hind limb kinematics of small non-cursorial mammals. A common feature seen in smaller mammals, in general, is the horizontal position of the thigh at touchdown and of the lower leg at lift-off. Thus, the maximum bone length is immediately transferred into the step length. The vertical position of the leg at the beginning of a step cycle and of the thigh at lift-off contributes the same distance to pivot height. Step length and pivot height increase proportionally with hind limb length, because intralimb proportions of the hind limb remain fairly constant. Therefore, the strong positive allometric scaling of the hind limb in arboreal quadrupedal primates affects neither the kinematics of hind limb segments nor the total angular excursion of the limb. The angular excursion of the hind limb in quadrupedal primates is equal to that of other non-cursorial mammals. Hence, hind limb excursion in larger cercopithecine primates differs from that of other large mammals due to the decreasing angular excursion as part of convergent cursorial adaptations in several phylogenetic lineages of mammals. Typical members of those phylogenetic groups are traditionally used in comparison with typical primates, and therefore the`uniqueness' of primate locomotor characteristics is often overrated.
Spatial orientation in echolocating harbour porpoises (Phocoena phocoena)
Authors: Verfuß Ursula K. , Miller Lee A. , Schnitzler Hans-Ulrich
Published: August 2005

Studies concerning the echolocation behaviour of odontocetes focus mainly on target detection and discrimination, either in stationary animals or in animals approaching a specific target. We present the first data on the use of echolocation for spatial orientation or navigation. Synchronised video and high-frequency recordings were made of two harbour porpoises trained to swim from one position to another across an outdoor pool in order to correlate swimming and echolocation behaviour. Both porpoises showed a clear range-locking behaviour on specific positions near the end of the pool, as indicated by a decrease in click interval with decreasing distance. The decrease in click interval followed the two-way-transit time, which is the time interval between the outgoing click and the received echo from the focal object. This suggests that the porpoises used focal objects as landmarks. The lag time, defined as the time between the arrival of an echo from a landmark and the emission of the next click, was task specific. The lag time was longer for difficult tasks (26–36 ms) and shorter for simpler tasks(14–19 ms), with some individual differences between the two animals. Our results suggest that echolocation by odontocetes is used not only for target detection, localisation and classification but also for spatial orientation.
Identification and characterization of a tachykinin-containing neuroendocrine organ in the commissural ganglion of the crabCancer productus
Authors: Messinger Daniel I. , Kutz Kimberly K. , Le Thuc , Verley Derek R. , Hsu Yun-Wei A. , Ngo Christina T. , Cain Shaun D. , Birmingham John T. , Li Lingjun , Christie Andrew E.
Published: August 2005

A club-shaped, tachykinin-immunopositive structure first described nearly two decades ago in the commissural ganglion (CoG) of three species of decapod crustaceans has remained enigmatic, as its function is unknown. Here, we use a combination of anatomical, mass spectrometric and electrophysiological techniques to address this issue in the crab Cancer productus. Immunohistochemistry using an antibody to the vertebrate tachykinin substance P shows that a homologous site exists in each CoG of this crab. Confocal microscopy reveals that its structure and organization are similar to those of known neuroendocrine organs. Based on its location in the anterior medial quadrant of the CoG, we have named this structure the anterior commissural organ (ACO). Matrix-assisted laser desorption/ionization Fourier transform mass spectrometry shows that the ACO contains the peptide APSGFLGMRamide,commonly known as Cancer borealis tachykinin-related peptide Ia(CabTRP Ia). Using the same technique, we show that CabTRP Ia is also released into the hemolymph. As no tachykinin-like labeling is seen in any of the other known neuroendocrine sites of this species (i.e. the sinus gland, the pericardial organ and the anterior cardiac plexus), the ACO is a prime candidate to be the source of CabTRP Ia present in the circulatory system. Our electrophysiological studies indicate that one target of hemolymph-borne CabTRP Ia is the foregut musculature. Here, no direct CabTRP Ia innervation is present, yet several gastric mill and pyloric muscles are nonetheless modulated by hormonally relevant concentrations of the peptide. Collectively,our findings show that the C. productus ACO is a neuroendocrine organ providing hormonal CabTRP Ia modulation to the foregut musculature. Homologous structures in other decapods are hypothesized to function similarly.
Generalization of convex shapes by bees: what are shapes made of?
Authors: Lehrer Miriam , Campan Raymond
Published: August 2005

For about 70 years, bees were assumed not to possess the capacity to discriminate among convex shapes, such as a disc, a square or a triangle,based on results of early studies conducted by presenting shapes on horizontal planes. Using shapes presented on a vertical plane, we recently demonstrated that bees do discriminate among a variety of convex shapes. Several findings,summarized here, provide indirect evidence that discrimination is based on a cue located at the shapes' boundaries. In the present study, we test this hypothesis directly in two different ways. (1) Three groups of bees are each trained with a different pair of convex shapes, one positive (rewarding), the other not (negative), producing colour contrast, luminance contrast or motion contrast against the background. The trained bees are then offered a choice between pairs of stimuli whose shapes are identical to those of the training shapes, but whose contrast against the background is varied by changing the pattern, the colour or the luminance of the areas. The results show that bees discriminate between the pairs of novel shapes, i.e. they generalize the shapes among the different types of contrast, revealing that they use a particular cue extracted from the positive shape. The bees' choices between a stimulus that produces the correct contrast but has the wrong shape and one that possesses the correct shape but the wrong contrast show, in addition,that the relevant cue is not located within the area of the shape. (2) Bees trained with pairs of convex shapes are tested with the same pairs of shapes,but which lack the inner area, i.e. only the contours or fragments of the contours are presented in the tests. Bees are found to prefer the stimulus whose contours (or fragments of contours) agree with those of the positive training shape. Taken together, the results suggest that convex shapes are not represented by the form of their areas but rather by some cue located at their boundaries.
Adsorption of Phenol from Aqueous Solution by Aminated Hypercrosslinked Polymers
Authors: Sun Yue , Chen Jin-Long , Li Ai-Min , Liu Fu-Qiang , Zhang Quan-Xing
Published: August 2005

The adsorption of phenol from aqueous solution onto the hypercrosslinked polymeric adsorbent NDA-100 and its dimethylamine aminated derivatives AH-1, AH-2 and AH-3, the commercial resin Amberlite XAD-4 and the weakly basic anion-exchange resin D301 was compared. Of the tested polymers, the aminated hypercrosslinked resins had the highest adsorption capacities. The empirical Freundlich equation was successfully employed to describe the adsorption process. The specific surface area and the micropore structure of the adsorbent together with the tertiary amino group on the matrix affected the adsorption performance towards phenol. Furthermore, these factors also influenced the thermodynamic properties. Kinetic studies demonstrated that the presence of the tertiary amino group on the polymer matrix decreased the adsorption rate and increased the apparent activation energy of the adsorption process.
Nickel Recovery from Aqueous Solution Using Crab Shell Particles
Authors: Vijayaraghavan Kuppusamy , Jegan Joseph Raj , Palanivelu Kandasamy , Velan Manickam
Published: August 2005

The potential use of crab shell as a sorbent for the removal of nickel(II) ions from aqueous solution was investigated. The binding of nickel ions by crab shell was found to be affected significantly by pH, with the maximum sorption capacity being observed at pH 4.5. The sorption isotherm was well represented using the Freundlich model. Nickel(II) ion removal by crab shell was mainly influenced by the removal of calcium carbonate, proteins and chitin, indicating the importance of these components in nickel ion binding. Co-ions such as Cu2+, Co2+, Cd2+, Zn2+ and Mg2+ affected the Ni(II) ion removal efficiency of crab shell.

The biosorbed Ni(II) ions were effectively eluted by various mineral acids, EDTA solutions and NH4OH. Of these, the sodium salt of EDTA (0.01 M) in NH4OH appeared to be the best eluant, being capable of desorbing more than 99% of the sequestered Ni(II) ions with insignificant damage to the shell particles. The biosorbent could be regenerated and re-used in five sorption—elution cycles.