bluuebunny/crossref_metadata_2025_split huggingface dataset:
High K+ and IGF‐1 protect cerebellar granule neurons via distinct signaling pathways
Authors: Zhong Jin , Deng Jixian , Huang Su , Yang Xianlin , Lee Wei‐Hua 
Published: February 2004

AbstractIn culture, cerebellar granule neurons die of apoptosis in serum‐free media containing a physiologic level of K+ but survive in a depolarizing concentration of K+ or when insulin‐like growth factor 1 (IGF‐1) is added. Both Akt/PKB activation and caspase‐3 inhibition were implicated as the underlying neuroprotective mechanisms. The duration of high K+, however, induced survival effects that outlasted its transient activation of Akt, and granule neurons derived from caspase‐3 knockout mice died to the same extent as did those from wild‐type mice, suggesting that additional mechanisms are involved. To delineate these survival mechanisms, we compared the activities of two major survival pathways after high K+‐induced depolarization or IGF‐1 stimulation. Although IGF‐1 promoted neuronal survival by activating its tyrosine kinase receptor, high K+ depolarization provided the same effect by increasing the Ca2+ influx through the L Ca2+ channel. Moreover, high K+‐induced depolarization resulted in sustained activation of MAP kinase, whereas IGF‐1 activated Akt in 4 hr. Inhibition of MEK (MAP kinase kinase) by either PD98059 or UO126 abolished the protective effect of high K+‐induced depolarization, but not that of IGF‐1, suggesting that activation of the MAP kinase pathway is necessary for high K+ neuroprotective effects. We demonstrated also that high K+‐induced depolarization, but not IGF‐1, increased phosphorylation of cAMP‐response element‐binding protein (CREB) and protein synthesis, both of which can be blocked by UO126. Overall, our findings suggested that high K+‐induced depolarization, unlike IGF‐1, promoted neuronal survival via activating MAP kinase, possibly by increasing CREB‐dependent transcriptional activation of specific proteins that promote neuronal survival. © 2004 Wiley‐Liss, Inc.
Characterization of a fast transient outward current in neocortical neurons from epilepsy patients
Authors: Rüschenschmidt C. , Köhling R. , Schwarz M. , Straub H. , Gorji A. , Siep E. , Ebner A. , Pannek H.W. , Tuxhorn I. , Wolf P. , Speckmann E.‐J. 
Published: February 2004

AbstractA‐type currents powerfully modulate discharge behavior and have been described in a large number of different species and cell types. However, data on A‐type currents in human brain tissue are scarce. Here we have examined the properties of a fast transient outward current in acutely dissociated human neocortical neurons from the temporal lobe of epilepsy patients by using the whole‐cell voltage‐clamp technique. The A‐type current was isolated with a subtraction protocol. In addition, delayed potassium currents were reduced pharmacologically with 10 mM tetraethylammonium chloride. The current displayed an activation threshold of about −70 mV. The voltage‐dependent activation was fitted with a Boltzmann function, with a half‐maximal conductance at −14.8 ± 1.8 mV (n = 5) and a slope factor of 17.0 ± 0.5 mV (n = 5). The voltage of half‐maximal steady‐state inactivation was −98.9 ± 8.3 mV (n = 5), with a slope factor of −6.6 ± 1.9 mV (n = 5). Recovery from inactivation could be fitted monoexponentially with a time constant of 18.2 ± 7.5 msec (n = 5). At a command potential of +30 mV, application of 5 mM 4‐aminopyridine or 100 μM flecainide resulted in a reduction of A‐type current amplitude by 35% or 22%, respectively. In addition, flecainide markedly accelerated inactivation. Current amplitude was reduced by 31% with application of 500 μM cadmium. All drug effects were reversible. In conclusion, neocortical neurons from epilepsy patients express an A‐type current with properties similar to those described for animal tissues. © 2004 Wiley‐Liss, Inc.
Lymphoscintigraphic and intraoperative detection of the sentinel lymph node in breast cancer patients: The nuclear medicine perspective
Authors: Mariani Giuliano , Erba Paola , Villa Giuseppe , Gipponi Marco , Manca Gianpiero , Boni Giuseppe , Buffoni Ferdinando , Castagnola Franca , Paganelli Giovanni , Strauss H. William 
Published: February 2004

AbstractThe concept of sentinel lymph node biopsy in breast cancer surgery relates to the fact that the tumor drains in a logical way via the lymphatic system, from the first to upper levels. Therefore, (1) the first lymph node met (the sentinel node) will most likely be the first one affected by metastasis, and (2) a negative sentinel node makes it highly unlikely that other nodes are affected. Sentinel lymph node biopsy would represent a significant advantage as a mini‐invasive procedure, considering that, after operation, about 70% of patients are found to be free from metastatic disease, yet axillary node dissection can lead to significant morbidity. Although the pattern of lymphatic drainage from a breast cancer can be very variable, the mammary gland and the overlying skin can be considered as a biologic unit in which lymphatics tend to follow the vasculature. Considering that tumor lymphatics are disorganized and relatively ineffective, subdermal, and peritumoral injection of small aliquots of radiotracer is preferred to intratumoral administration. 99mTc‐labeled colloids with most of the particles in the 100–200 nm size range would be ideal for radioguided sentinel node biopsy in breast cancer. Lymphoscintigraphy is an essential part of radioguided sentinel lymph node biopsy, as images are used to direct the surgeon to the site of the node. The sentinel lymph node should have a significantly higher count than background. After removal of the sentinel node, the axilla must be re‐examined to ensure all radioactive sites are identified and removed for analysis. The success rate of radioguidance in localizing the sentinel lymph node in breast cancer surgery is about 94–97% in Institutions where a high number of procedures are performed, approaching 99% when combined with the vital blue dye technique. At present, there is no definite evidence that a negative sentinel lymph node biopsy is invariably correlated with a negative axillary status, except perhaps for T1a‐b breast cancers, with size ≤1 cm. Randomized clinical trials should elucidate the impact of avoiding axillary node dissection in patients with a negative sentinel lymph node on the long‐term clinical outcome of patients. J. Surg. Oncol. 2004;85:112–122. © 2004 Wiley‐Liss, Inc.
Sentinel lymph node biopsy in breast cancer patients: The medical oncology perspective
Authors: Catzeddu Tiziana , Bertelli Gianfilippo , Del Mastro Lucia , Venturini Marco 
Published: February 2004

AbstractRecent data indicates that the sentinel lymph node biopsy (SLNB) is a possible alternative to axillary lymph node dissection (ALND) in early breast cancer patients, with minimal risk of complications.From the medical oncologist's point of view, the impact of SLNB on the management of patients should consider if SLNB is useful to choose adjuvant treatment, if it is adequate to provide local control, and what is the significance of lymph node micrometastases on treatment and staging. Lymph node involvement has always been recognised as the most important prognostic factor in early‐stage breast cancer, even if many other parameters have been evaluated in recent years. However, the lack of knowledge of nodal status in patients with false‐negative SLNB seems to result in an undertreatment in a very low percentage of patients. Adjuvant chemotherapy and hormonal therapy with tamoxifen are associated with an absolute reduction of the risk of recurrence and death both in node‐positive and in node‐negative patients, then if patients are treated with modern adjuvant systemic therapy, any effect associated with false negative SLN should be minimised.The impact of axillary treatment on survival is still controversial, but in recent times axillary lymph node positivity is considered as an indicator for high risk of systemic diffusion of the disease rather than a possible origin of systemic metastases.The significance of occult sentinel lymph node metastases detected by immunohistochemistry (IHC) or molecular biology on prognosis is still uncertain. The new version of the staging system of breast cancer has recognised the need for a standard diagnostic approach and of a nomenclature system which also takes SLNB into account. J. Surg. Oncol. 2004;85:129–132. © 2004 Wiley‐Liss, Inc.
Pathologic analysis of sentinel lymph nodes in melanoma patients: Current and future trends
Authors: Roberts Alice A. , Cochran Alistair J. 
Published: February 2004

AbstractSentinel lymph node dissection (SLND) has become the standard of care for the staging of clinically‐node negative melanomas and breast cancers. A large literature documents the efficacy of SLND in the staging of melanoma and breast cancer. The SLND has lower associated patient morbidity in comparison to elective node dissections that remove the closest regional‐draining node group. SLND has improved accuracy over traditional regional node dissection for the staging of melanoma. Currently, several multicenter trials are evaluating the prognostic significance of melanoma micrometastases in SLN detected by immunohistochemical and molecular methods. Pending trial outcome analysis, SLND has no proven effect on mortality. However, given the current oncologic emphasis on detection and removal of nodal tumor metastases, the technique has an important role in minimizing the invasiveness of tumor staging for melanoma and breast cancer. As long as lymph node metastases are used for staging solid malignancies, surgical pathologists are likely to encounter SLN excisional biopsies as a part of their routine practice. J. Surg. Oncol. 2004;85:152–161. © 2004 Wiley‐Liss, Inc.
Sentinel lymph node biopsy in melanoma patients: the medical oncologist's perspective
Authors: Queirolo Paola , Taveggia Paola , Gipponi Marco , Sertoli Mario Roberto 
Published: February 2004

AbstractWith the advent of sentinel node (sN) biopsy in melanoma patients, elective lymph node dissection (ELND) can be considered an exceeded procedure. Regardless of the possible therapeutic benefits, sN biopsy efficiently predicts prognosis avoiding the morbidity rate of ELND. The importance of the sN is underlined by multivariate analyses, which show that the sN status represents the most important prognostic factor influencing disease‐free and distant disease‐free survival in patients with stage I and II melanoma. Moreover, sN biopsy provides a minimally invasive method for identifying those patients with subclinical nodal metastasis who actually have stage III disease, with a very high risk of occult distant metastases and who may benefit by adjuvant therapy. J. Surg. Oncol. 2004;85:162–165. © 2004 Wiley‐Liss, Inc.
Prognostic value of sentinel lymph node biopsy in the pathologic staging of colorectal cancer patients
Authors: Bertoglio Sergio , Sandrucci Sergio , Percivale Pierluigi , Goss Matteo , Gipponi Marco , Moresco Luciano , Mussa Baudolino , Mussa Antonio 
Published: February 2004

AbstractBackground and ObjectivesOver the last decade, lymphatic mapping and sentinel lymph node (sN) biopsy have greatly increased the possibility of identifying nodal metastasis in clinically node‐negative patients with melanoma and breast cancer, thus improving the accuracy of pathologic staging. Recently, sN biopsy has been applied also in colorectal cancer. This prospective study aimed to assess its feasibility and accuracy in predicting regional lymph nodes metastases in colorectal cancer patients as well as the impact on treatment decision‐making.Materials and MethodsLymphatic mapping was accomplished by means of blue dye, which was intraoperatively injected into the subserosa overlying the tumor site in 26 patients undergoing colorectal cancer surgery. Following bowel resection, the operative specimen was inspected to identify each blue‐stained node, the sN, which was sent separately to the pathologist. One half of each sN was examined by multiple 200 μm sections, while the second half was examined by standard bi‐valving technique with hematoxylin‐eosin (H&E) staining; all the other regional non‐sentinel nodes were routinely examined by standard bi‐valving technique and H&E staining.ResultsAt least one sN was detected in 24 of 26 patients (92.3%); two patients with rectal cancer had no sN identified. Overall, 70 sN were retrieved into the operative specimens, with a mean of 2.9 sNs/patient, and 19 sNs were tumor‐positive. An agreement between sN and regional lymph‐node status was observed in 20 of 24 patients (83.4%). The sN was histologically negative in two of nine patients with positive regional nodes (sensitivity = 77.8%; false‐negative rate of 22.2%); in two of seven patients with tumor‐positive sN (28.6%), the sN was the exclusive site of regional nodal metastasis. The negative predictive value was 88.2% (15 of 17 patients), and the overall accuracy was 91.7% (22 of 24 patients). As regards the contribution to the detection of nodal metastasis according to the pathologic technique, standard H&E bi‐valving technique detected 16 of 19 tumor‐positive sNs (84.2%) while, by means of serial sectioning, metastases were detected in the remaining 3 of 19 sNs (15.8%).ConclusionsThe sN biopsy proved feasible, with a rather short learning curve. The focused analysis of the sN by means of serial sectioning improved the detection rate of nodal metastasis compared to standard bi‐valving examination, so that a more accurate nodal staging should be expected; finally, an elective localization of metastasis within the sN was observed in almost one third of regional node‐positive patients. J. Surg. Oncol. 2004;85:166–170. © 2004 Wiley‐Liss, Inc.
Rate constants for reaction of 1,2‐dimethylimidazole with benzyl bromide in ionic liquids and organic solvents
Authors: Skrzypczak A. , Neta P. 
Published: February 2004

AbstractThe rate constant for the Menschutkin reaction of 1,2‐dimethylimidazole with benzyl bromide to produce 3‐benzyl‐1,2‐dimethylimidazolium bromide was determined in a number of ionic liquids and molecular organic solvents. The rate constants in 12 ionic liquids are in the range of (1.0–3.2) × 10−3 L mol−1 s−1 and vary with the solvent anion in the order (CF3SO2)2 N− < PF6− < BF4−. Variations with the solvent cation (butylmethylimidazolium, octylmethylimidazolium, butyldimethylimidazolium, octyldimethylimidazolium, butylmethylpyrrolidinium, and hexyltributylammonium) are minimal. The rate constants in the ionic liquids are comparable to those in polar aprotic molecular solvents (acetonitrile, propylene carbonate) but much higher than those in weakly polar organic solvents and in alcohols. Correlation of the rate constants with the solvatochromic parameter ET(30) is reasonable within each group of similar solvents but very poor when all the solvents are correlated together. Better correlation is obtained for the organic solvents by using a combination of two parameters, π* (dipolarity/polarizibility) and α (hydrogen bond acidity), while additional parameters such as δ (cohesive energy density) do not provide any further improvement. © 2004 Wiley Periodicals, Inc.*This article is a US Government work and, as such, is in the public domain of the United States of America.
Int J Chem Kinet 36: 253–258, 2004
Gas‐phase radical–radical recombination reactions of nitroxides with substituted phenyl radicals
Authors: Heidbrink J. L. , Amegayibor F. S. , Kenttämaa H. I. 
Published: February 2004

AbstractFourier‐transform ion cyclotron resonance mass spectrometry has been used to examine gas‐phase reactions of four different nitroxide free radicals with eight positively charged pyridyl and phenyl radicals (some containing a Cl, F, or CF3 substituent). All the radicals reacted rapidly (near collision rate) with nitroxides by radical–radical recombination. However, some of the radicals were also able to abstract a hydrogen atom from the nitroxide. The results establish that the efficiency (kreaction/kcollision) of hydrogen atom abstraction varies with the electrophilicity of the radical, and hence is attributable to polar effects (a lowering of the transition‐state energy by an increase in its polar character). The efficiency of the recombination reaction is not sensitive to substituents, presumably due to a very low reaction barrier. Even so, after radical–radical recombination has occurred, the nitroxide adduct was found to fragment in different ways depending on the structure of the radical. For example, a cationic fragment was eliminated from the adducts of the more electrophilic radicals via oxygen anion abstraction by the radical (i.e., the nitroxide adduct cleaves heterolytically), whereas adducts of the less electrophilic radicals predominantly fragmented via homolytic cleavage (oxygen atom abstraction). Therefore, differences in the product branching ratios were found to be attributable to polar factors. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 216–229 2004
First‐order stochastic cellular automata simulations of the lindemann mechanism
Authors: Hollingsworth Chad A. , Seybold Paul G. , Kier Lemont B. , Cheng Chao‐Kun 
Published: February 2004

AbstractThe Lindemann mechanism explains how apparent unimolecular chemical reactions arise from bimolecular collisions. In this mechanism an ingredient M activates reactants A through collisions, and the resulting activated species A* can either decay to products P or be deactivated back to A, again via collisions with M. A first‐order stochastic cellular automata model described previously [Seybold, Kier, and Cheng, J Chem Inf Comput Sci 1997, 37, 386] has been modified to simulate this mechanism. It is demonstrated that this model accurately reflects the salient features of the Lindemann mechanism, including the normal second‐order kinetic behavior at low [M] and apparent first‐order kinetics at high [M]. At low [M] the mechanism is equivalent to a rate‐limited sequential process, whereas at high [M] it becomes a preequilibrium with leakage to products. The model also allows an examination of the validity of the steady‐state approximation normally employed in a deterministic analysis of this mechanism, and it is seen that this approximation is not well justified under reasonable conditions. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 230–237 2004
Investigation of the correlation of sensitivity vectors of hydrogen combustion models
Authors: Zádor Judit , Zsély István Gy. , Turányi Tamás 
Published: February 2004

AbstractA well‐established method for the analysis of large reaction mechanisms is the calculation and interpretation of the sensitivity of the kinetic model output Yi to parameter changes. Comparison of the sensitivity vectors si = {∂ Yi/∂p} belonging to different model outputs is a new tool for kinetic analysis. The relationship of the sensitivity vectors was investigated in homogeneous explosions, freely propagating and burner‐stabilized laminar flames of hydrogen–air mixtures, using either calculated adiabatic or constrained temperature profiles, for fuel‐to‐air ratios φ = 0.5–4.0. Sensitivity vectors are called locally similar, if the relationship si = λijsj is valid, where λij is a scalar. In many systems, only approximate local similarity of the sensitivity vectors exists and the extent of it can be quantified by using an appropriate correlation function. In the cases of adiabatic explosions and burner‐stabilized flames, accurate local similarity was present in wide ranges of the independent variable (time or distance), and the correlation function indicated that the local similarity was not valid near the concentration extremes of the corresponding species. The regions of poor similarity were studied further by cobweb plots. The correlation relationships found could be interpreted by the various kinetic processes in the hydrogen combustion systems. The sensitivity vector of the laminar flame velocity is usually considered to be characteristic for the whole combustion process. Our investigations showed that the flame velocity sensitivity vector has good correlation with the H and H2O concentration sensitivities at the front of the adiabatic flames, but there is poor correlation with the sensitivity vectors of all concentrations in homogeneous explosions. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 238–252 2004
A 308‐nm excimer laser for the treatment of scalp psoriasis
Authors: Taylor Charles R. , Racette Ashley L. 
Published: February 2004

AbstractBackground and ObjectivesScalp psoriasis is a frustrating disorder whose treatments can all too often be cumbersome and ineffective. Our objective was to test a combination device involving the 308‐nm excimer laser in tandem with a hair blower for treating scalp psoriasis.Study Design/Materials and MethodsAdult subjects with scalp psoriasis unresponsive to class I topical steroids used in conjunction with medicated shampoos were treated with 308‐nm excimer laser pulses in conjunction with a hair blower that parted the obstructing hair twice a week for up to 15 weeks. Half of the scalp served as a control. Starting doses were based on standard minimal erythema dose (MED)'s with subsequent increments of up to 20%.ResultsThirteen subjects completed the study without adverse events. Two were dropped due to lack of compliance. At the end of the investigation, the difference in the mean modified PASI scores between the control and treated sites was 4.0 (<0.0001).ConclusionsThe air blower device in conjunction with the 308‐nm excimer laser can safely and effectively treat otherwise refractory scalp psoriasis. Lasers Surg. Med. 34:136–140, 2004. © 2004 Wiley‐Liss, Inc.
The depth measuring videomicroscope (DMV): A non‐invasive tool for the assessment of capillary vascular malformations
Authors: Sivarajan Vivek , Mackay Iain R. 
Published: February 2004

AbstractBackground and ObjectivesThe response of capillary vascular malformations (CVMs) to laser treatment is believed to be due to the pattern of capillary ectasia, the depth, diameter, and flow through these capillaries and the amount of competing chromophores within the skin. Videomicroscopy has successfully been used to determine CVM capillary pattern and diameter of vessels. The depth measuring videomicroscope (DMV) allows the depth of capillaries to be measured also. The aim of this study is to examine how capillary depths within a CVM are affected by dye laser treatment using DMV.Study Design/Materials and MethodsThirteen previously untreated patients were examined in a temperature‐controlled room. A DMV examination was carried out prior to and 6 weeks following a treatment with pulsed dye laser. A further cohort of 11 resistant CVM patients, who had all received over five treatments, was also examined for comparison.ResultsUsing a Wilcoxon Signed rank test, the results showed that the remaining vessels within the CVM as measured using DMV were more deeply located and smaller (P < 0.01 and P < 0.02 respectively), following the laser treatment. Also in the resistant patients the vessels were again more deeply placed and smaller.ConclusionsThe hypothesis that smaller and more deeply placed CVM vessels respond poorest to laser treatment is supported by these findings. Moreover, the DMV provides a simple non‐invasive technique for demonstrating this. Lasers Surg. Med. 34:193–197, 2004. © 2004 Wiley‐Liss, Inc.