bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Effects on Green Sturgeon Bioenergetics
Authors: Mayfield Ryan B. , Cech Joseph J.
Published: July 2004

The green sturgeon Acipenser medirostris is relatively rare, and little is known about the effects of important habitat‐related influences on its life history. Temperature directly or indirectly impacts the distribution of fish as well as their physiological and behavioral processes. Because the Klamath and Rogue rivers may reach 24–25°C and egg and embryo incubation temperatures above 22°C are associated with deformities in juvenile green sturgeon, data on the temperature‐related bioenergetic responses of these juveniles would be especially useful in designing effective conservation and management strategies. We measured the food consumption, growth, food conversion efficiency, oxygen consumption, volitional activity, ventilatory frequency, thermal preference, and swimming performance of juveniles at several temperatures spanning their warm‐season temperature range (11–24°C). Food consumption, growth, and food conversion efficiency generally increased with temperature between 11°C and 15°C but stayed constant between 15°C and 19°C. Growth increased and food conversion efficiency decreased with ration size. Oxygen consumption, volitional activity rate, and ventilatory frequency generally increased with temperature, while preferred temperature increased and swimming performance decreased with temperature from 19°C to 24°C. Relative to other sturgeon species, the green sturgeon has high growth and oxygen consumption rates. Overall, we found that bioenergetic performance was optimal between 15°C and 19°C under either full or reduced rations, thus providing a temperature‐related habitat target for conservation of this rare species.
Smallmouth Bass Predation on Hatchery and Wild Salmonids in the Yakima River, Washington
Authors: Fritts Anthony L. , Pearsons Todd N.
Published: July 2004

Predation on hatchery and wild salmonids by nonnative smallmouth bassMicropterus dolomieuwas examined in the lower Yakima River, Washington, in March through June of 1998 to 2001. Smallmouth bass were sampled weekly using a drift‐boat electrofisher in two sections of the river. Average abundance estimates of smallmouth bass 150 mm fork length or longer for the 4 years sampled ranged from 3,347 in late March to 19,438 in early June. Abundance estimates from 1998 to 2001 all showed a similar trend of increasing abundance throughout the spring. Salmonids were identified in the guts of smallmouth bass throughout the sampling period and were most prevalent during the month of May. Ocean‐type Chinook salmonOncorhynchus tshawytschaconstituted 47% of all the fish species identified in the gut samples. Smallmouth bass were estimated to have consumed an average of 200,405 salmonids yearly from March 22 to June 16 in 1998–2001; of these, only 3,176 were yearling salmonids (primarily spring Chinook salmon). Smallmouth bass predation on all yearling salmonids never exceeded 0.6% of the annual production of hatchery and wild fish combined. We estimated that as much as 85% of the ocean‐type Chinook salmon consumed by smallmouth bass in a given year were of natural origin. Estimated smallmouth bass consumption of hatchery ocean‐type Chinook salmon has only comprised up to 4% of production in a single year. Our estimates of consumption on ocean‐type Chinook salmon are likely to be underestimates because we did not sample throughout the entire rearing and emigration period of these fish. Our results indicate that smallmouth bass can have negative impacts on ocean‐type Chinook salmon, particularly those that are naturally produced, which are generally smaller and available longer than hatchery fish.
Are There Differences in Growth and Condition between Mobile and Resident Cutthroat Trout?
Authors: Hilderbrand Robert H. , Kershner Jeffrey L.
Published: July 2004

There is evidence that actively moving salmonids are of lower condition than the general population, and they are sometimes regarded as inferior to resident fish. However, little information exists on the permanence of this attribute. We used mark–recapture and two‐way traps to determine whether there are differences in the condition and growth of mobile and resident Bonneville cutthroat trout Oncorhynchus clarki utah in Beaver Creek, Idaho. Actively moving fish were significantly larger than the general population, and the largest of these mobile fish were in significantly lower condition for a given size. However, mobile fish that were marked and recaptured a year later had regained condition equivalent to that of the general population upon their recapture, and the largest mobile fish had significantly greater condition than fish of equal length in the general population. In contrast, there was no relationship between growth rate and the total distance moved during the 1‐year period. These results suggest that the lower condition of actively moving fish does not have permanent effects on future condition or growth in stream‐resident cutthroat trout.
Spatial Variation in Fish Species Richness of the Upper Mississippi River System
Authors: Koel Todd M.
Published: July 2004

Important natural environmental gradients, including the connectivity of off‐channel aquatic habitats to the main‐stem river, have been lost in many reaches of the upper Mississippi River system, and an understanding of the consequences of this isolation is lacking in regard to native fish communities. The objectives of this study were to describe patterns of fish species richness, evenness, and diversity among representative habitats and river reaches and to examine the relationship between fish species richness and habitat diversity. Each year (1994–1999) fish communities of main‐channel borders (MCB), side channel borders (SCB), and contiguous backwater shorelines (BWS) were sampled using boat‐mounted electrofishing, mini‐fyke‐nets, fyke nets, hoop nets, and seines at a standardized number of sites. A total of 0.65 million fish were collected, representing 106 species from upper Mississippi River Pools 4, 8, 13, and 26; the open (unimpounded) river reach; and the La Grange Reach of the Illinois River. Within pools, species richness based on rarefaction differed significantly among habitats and was highest in BWS and lowest in MCB (P < 0.0001). At the reach scale, Pools 4, 8, and 13 consistently had the highest species richness and Pool 26, the open‐river reach, and the La Grange Reach were significantly lower (P < 0.0001). Species evenness and diversity indices showed similar trends. The relationship between native fish species richness and habitat diversity was highly significant (r2 = 0.85; P = 0.0091). These results support efforts aimed at the conservation and enhancement of connected side channels and backwaters. Although constrained by dams, pools with high native species richness could serve as a relative reference. The remnants of natural riverine dynamics that remain in these reaches should be preserved and enhanced; conditions could be used to guide restoration activities in more degraded reaches.
Pink Salmon Spawning Habitat is Recovering a Decade after the Exxon Valdez Oil Spill
Authors: Carls Mark G. , Rice Stanley D. , Marty Gary D. , Naydan Diane K.
Published: July 2004

Intertidal sediment surrounding many spawning streams for pink salmon Oncorhynchus gorbuscha in western Prince William Sound, Alaska, was contaminated by the Exxon Valdez oil spill in 1989. Biochemical and egg‐dig evidence suggested that oil reduced the survival of pink salmon embryos for several years. Previous research also demonstrated that dissolved oil can be transferred to developing embryos from surrounding oiled sediment via drainage of interstitial water as a result of tidal cycling and hydraulic gradients. In this study, completed a decade after the spill, we sampled stream water for the presence of oil using passive membrane sampling devices, collected sediment and pink salmon eggs for hydrocarbon analysis, and examined alevins for induction of cytochrome P4501A (CYP1A). Polynuclear aromatic hydrocarbons (PAHs) consistent with Exxon Valdez oil were present in the water of one of six heavily impacted streams; total PAH concentrations in the stream were greatest in the lower intertidal zone. Similarly distributed total PAHs in a second stream suggested possible contamination. Oil was not detected in the remaining four streams. Induction of CYP1A in pink salmon alevins from the two contaminated streams was lowest in water above mean high tide and increased downstream. Because our samples were all selected from heavily oiled streams, we infer that most pink salmon spawning habitat either has recovered or is recovering.
Fallback, Reascension, and Adjusted Fishway Escapement Estimates for Adult Chinook Salmon and Steelhead at Columbia and Snake River Dams
Authors: Boggs C. T. , Keefer M. L. , Peery C. A. , Bjornn T. C. , Stuehrenberg L. C.
Published: July 2004

During their upstream spawning migration in the Columbia River basin, some adult salmonids Oncorhynchus spp. ascend and then fall back over main‐stem hydroelectric dams. Fallback can result in fish injury or death, migration delays, and biases in fishway counts, the primary index for escapement and the basis for production estimates and harvest quotas. We used radiotelemetry to calculate fallback percentages and rates, reascension percentages, biases in fishway escapement estimates due to fallback, and occurrence of behaviorally motivated fallback (correcting overshoot of natal sites) by spring–summer and fall Chinook salmon O. tshawytscha and steelhead O. mykiss. The study area included eight Columbia River and Snake River dams evaluated from 1996 to 2001. For all years combined, about 22% of spring–summer Chinook salmon, 15% of fall Chinook salmon, and 21% of steelhead fell back at least once at a dam. Fallback percentages for spring–summer Chinook salmon were generally highest at Bonneville and the Dalles dams and decreased at progressively upstream dams. Fallback rates for spring–summer Chinook salmon were positively correlated with river discharge. Fallback percentages for steelhead and fall Chinook salmon were less variable between years but were more variable between dams than those of spring–summer Chinook salmon. Reascension percentages at dams ranged widely between runs and sites and were negatively related to the number of fish that entered tributaries downstream from the fallback location. Fall Chinook salmon were the most likely to enter a downstream tributary after falling back, though this behavior was also observed in spring–summer Chinook salmon and steelhead. For all years and at all dams, fallback produced positive fishway count biases ranging from 1% to 16% for spring–summer Chinook salmon, 1% to 38% for fall Chinook salmon, and 1% to 12% for steelhead.
Predicting Invasions of North American Basses in Japan Using Native Range Data and a Genetic Algorithm
Authors: Iguchi Kei'ichiro , Matsuura Keiichi , McNyset Kristina M. , Peterson A. Townsend , Scachetti‐Pereira Ricardo , Powers Katherine A. , Vieglais Dave A. , Wiley E. O. , Yodo Taiga
Published: July 2004

Largemouth bass Micropterus salmoides and smallmouth bass M. dolomieu have been introduced into freshwater habitats in Japan, with potentially serious consequences for native fish populations. In this paper we apply the technique of ecological niche modeling using the genetic algorithm for rule‐set prediction (GARP) to predict the potential distributions of these two species in Japan. This algorithm constructs a niche model based on point occurrence records and ecological coverages. The model can be visualized in geographic space, yielding a prediction of potential geographic range. The model can then be tested by determining how well independent point occurrence data are predicted according to the criteria of sensitivity and specificity provided by receiver–operator curve analysis. We ground‐truthed GARP's ability to forecast the geographic occurrence of each species in its native range. The predictions were statistically significant for both species (P < 0.001). We projected the niche models onto the Japanese landscape to visualize the potential geographic ranges of both species in Japan. We tested these predictions using known occurrences from introduced populations of largemouth bass, both in the aggregate and by habitat type. All analyses robustly predicted known Japanese occurrences (P < 0.001). The number of smallmouth bass in Japan was too small for statistical tests, but the 10 known occurrences were predicted by the majority of models.
Oxazolidinones, Antibacterials
Authors: Hollingsworth Rawle I. , Wang Guijun
Published: July 2004

Oxazolidinones hold great promise as the new line of defense against bacteria that have become resistance to the spectrum of available therapies. Much success has been realized in the treatment of infections by drug resistantStaphylococcus aureus, Enterococcus faecium, andStreptococcus pneumonia strainsby the introduction of linezolid (Zyvox). Multidrug resistance involving these pathogens represents one of the largest unmet needs in medicine today. As a class oxazolidinones have not shown great promise in the treatment of gram‐negative infections. The overall activity spectrum of this class of drugs is relatively narrow and this has been a significant restriction in their use. The structure activity relationships have been relatively well characterized and the mode of interaction with the ribosome to prevent protein synthesis is being elucidated. The negative effect of linezolid on bone marrow production is a matter of some concern. Several linezolid resistant strains have now been reported.
Chemical Vapor Deposition
Authors: Chiu Hsin‐Tien
Published: July 2004

Chemical vapor deposition (CVD) is a chemical process that transforms vapor‐phase molecules, called precursors, into solid materials, such as thin films on substrates and powders. This process is carried out inside a flow reactor. By supplying either thermal, photo‐ or plasma energy to the reactor, the precursors are activated and decomposed to deposit the solids. The process is widely used to produce thin films for semiconductor devices and protective coatings on precision machine parts. It is also capable of producing fine powders, nanotubes, nanorods, and nanowires of many different materials.
Dynamic flow in a Kenics static mixer: An assessment of various CFD methods
Authors: van Wageningen W. F. C. , Kandhai D. , Mudde R. F. , van den Akker H. E. A.
Published: July 2004

The flow in the Kenics static mixer is investigated in detail both numerically and experimentally in the range of Re = 100…1000. It was found that at Re = 300 the flow becomes unsteady. Two numerical methods, the lattice Boltzmann (LB) method and FLUENT, were compared and used to simulate the flow. The LB method proved to be a relatively fast and cheap (in terms of memory) alternative for the simulation of the transient flow in the Kenics static mixer at Re > 300. Furthermore, the flow field and dynamic behavior were validated by means of LDA experiments. The transient behavior observed could be explained by studying the dynamics of the vortices in the flow. The transition to unsteady flow takes place, when the vortices start to stretch out over an entire mixing element and create a disturbance in the flow, which subsequently triggers the unsteady behavior. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1684–1696, 2004
Querung des Elbe‐Seitenkanals und des Mittellandkanals mittels Horizontal‐Directional‐Drilling für eine 380‐km‐Pipeline
Authors: Dietel Eckhard , Lübbers Hermann
Published: July 2004

Das Bundeswasserstraßennetz umfaßt rd. 7500 km Binnenwasserstraßen. Neben der verkehrswirtschaftlichen Nutzung haben die Wasserstraßen auch eine außerverkehrliche Funktion, insbesondere im wasserwirtschaftlichen Bereich (Wasserversorgung für Industrie und Landwirtschaft, Hochwasserschutz u.a.). Die Bundesrepublik Deutschland als Eigentümer der Bundeswasserstraßen verwaltet diese gemäß Artikel 87 und 89 Grundgesetz durch eigene Behörden, die Wasser‐ und Schifffahrtsverwaltung des Bundes (WSV), örtlich vertreten durch das jeweils zuständige Wasser‐ und Schifffahrtsamt (WSA). Das WSA ist gemäß § 31 Bundeswasserstraßengesetz (WaStrG) Genehmigungsbehörde für strom‐ und schifffahrtspolizeiliche Genehmigungen von Anlagen Dritter, die den Verkehrsweg Bundeswasserstraße beabsichtigen zu kreuzen oder zu dükern, wie im vorliegenden Fall. Im Zuge der 380 km langen Pipeline von Stade nach Teutschenthal (PST) wurden insgesamt 203 Bohrungen in der HDD‐Technik durchgeführt. 24 Querungen waren größere Fluß‐ und Kanalquerungen. Zwei technisch extrem anspruchsvolle Projekte stellten dabei die Querung des Elbe‐Seitenkanals und des Mittellandkanals dar.
Querkraft‐ und Torsionsbemessung nach DIN 1045‐1 (07.01)
Authors: Friedrich Richard
Published: July 2004

Für schlaff bewehrte Bauteile aus normalfestem Normalbeton werden grafische Hilfsmittel für die Querkraftbemessung und für die Torsionsbemessung und auch für deren vereinfachte Kombination vorgestellt. Ein Beispiel zeigt die praktische Anwendung.
Rapid separation of barbiturates and benzodiazepines by capillary electrochromatography with 3‐(1,8‐naphthalimido)propyl‐modiﬁed silyl silica gel
Authors: Ohyama Kaname , Wada Mitsuhiro , Ohba Yoshihito , Fujishita Osamu , Nakashima Kenichiro , Kuroda Naotaka
Published: July 2004

A capillary electrochromatographic (CEC) method was applied to the simultaneous separation of barbiturates (barbital, phenobarbital, secobarbital and thiopental) and benzodiazepines (nitrazepam, diazepam and triazolam). The separation was performed in a 75 µm i.d. capillary, packed with 3‐(1,8‐naphthalimido)propyl‐modiﬁed silyl silica gel (NAIP), studying the effects of buffer pH and mobile phase composition. Using an applied voltage of 20 kV and the short‐end injection method (9 cm capillary effective length), the mobile phase of 1.0 mm citrate buffer (pH 5.0) containing 45% methanol provided the baseline separation of seven toxic drugs in less than 9 min. In CEC with NAIP, the benzodiazepines were separated by the combination of hydrophobic and π–π interactions, whereas the separation of the barbiturates was based on the hydrophobic interaction. Copyright © 2004 John Wiley & Sons, Ltd.
Liquid chromatographic determination of polyamines in human urine based on intramolecular excimer‐forming fluorescence derivatization using 4‐(1‐pyrene)butanoyl chloride
Authors: Yoshida Hideyuki , Harada Hajime , Nakano Yukitaka , Nohta Hitoshi , Ishida Junichi , Yamaguchi Masatoshi
Published: July 2004

A liquid chromatographic method for highly sensitive and selective fluorometric determination of polyamines (putrescine, cadaverine, spermidine and spermine) in human urine is described. This method is based on an intramolecular excimer‐forming fluorescence derivatization with a pyrene reagent, 4‐(1‐pyrene)butanoyl chloride (PBC), followed by reversed‐phase liquid chromatography. The method offers higher sensitivity for determination of spermidine and spermine than previously reported method utilizing 4‐(1‐pyrene)butyric acid N‐hydroxysuccinimide ester as a derivatization reagent. Samples containing free polyamines in diluted human urine were directly derivatized with PBC and separated on an octyl column. The derivatives were detected at excitation 345 and emission 475 nm wavelengths. For determination of total polyamine content, the conjugated polyamines were first hydrolyzed in 4 m HCl. The detection limits (signal‐to‐noise ratio = 3) for polyamines in urine were 1.1–3.4 pmol/mL. At optimized derivatization and chromatographic conditions, interferences such as biogenic monoamines gave no peaks or the peaks did not interfere with the peaks of polyamine derivatives. In conclusion, the present derivatization method allows direct determination of polyamines in human urine samples without the need for sample clean‐up procedures. Copyright © 2004 John Wiley & Sons, Ltd.
Intravenous administration of 2,7,8‐trimethyl‐2‐(β‐carboxyethyl)‐6‐hydroxy chroman (γ‐CEHC) to rats and determination of its plasma concentration and urinary sodium excretion
Authors: Tanabe Maiko , Fukushima Takeshi , Usui Noriko , Aoyama Nozomi , Tsunoda Makoto , Imai Kazuhiro
Published: July 2004

A natriuretic hormone, 2,7,8‐trimethyl‐2‐(β‐carboxyethyl)‐6‐hydroxy chroman (γ‐CEHC) was administered intravenously to male Sprague–Dawley rats and the plasma concentration of γ‐CEHC along with urinary sodium (Na+) excretion was investigated. The plasma γ‐CEHC concentrations were ﬂuorimetrically determined by a column‐switching HPLC method consisting of both phenyl and octadecyl silica columns, following a pre‐column ﬂuorescence derivatization with a ﬂuorescence reagent, 4‐N,N‐dimethylaminosulfonyl‐7‐piperazino‐2,1,3‐benzoxadiazole (DBD‐PZ). In rats fed with a high‐NaCl (8.0%) diet, plasma γ‐CEHC concentrations rapidly decreased by 20% in 15–45 min after the adminstration of γ‐CEHC, while Na+ excretion gradually increased with time. Considering these results, the Na+ excretion effect appeared not to be associated with plasma γ‐CEHC concentration. In addition, attempts were made to examine a main urinary metabolite of γ‐CEHC, a large amount of 6‐O‐sulfated γ‐CEHC found to be present in the urine using an HPLC‐tandem mass spectrometry. Thus, it is plausible that γ‐CEHC was easily metabolized to 6‐O‐sulfated metabolite and excreted into urine in rats. Copyright © 2004 John Wiley & Sons, Ltd.
Switching from an analogous to a stable isotopically labeled internal standard for the LC‐MS/MS quantitation of the novel anticancer drug Kahalalide F signiﬁcantly improves assay performance
Authors: Stokvis E. , Rosing H. , López‐Lázaro L. , Schellens J. H. M. , Beijnen J. H.
Published: July 2004

The importance of a stable isotopically labeled (SIL) internal standard for the quantitative LC‐MS/MS assay for Kahalalide F in human plasma is highlighted. Similar results can be expected for other LC‐MS/MS assays. Therefore, we emphasize the need for an SIL internal standard for accurate and precise LC‐MS/MS assays of drugs in biological matrices. Copyright © 2004 John Wiley & Sons, Ltd.
Progress in 1,2,3,4‐Tetrazine Chemistry
Authors: Churakov Aleksandr M. , Tartakovsky Vladimir A.
Published: July 2004

For Abstract see ChemInform Abstract in Full Text.
Postoperative serum carcinoembryonic antigen levels in patients with pathologic stage IA nonsmall cell lung carcinoma
Authors: Sawabata Noriyoshi , Maeda Hajime , Yokota Soichiro , Takeda Shin‐ichi , Koma Masaru , Tokunaga Toshiteru , Ito Masami
Published: July 2004

BACKGROUND

Elevated serum carcinoembryonic antigen (CEA) levels are sometimes attributable to the production of CEA by malignant cells, and in turn, the antigen itself can enhance the metastatic potential of malignant cells. The authors speculated that low serum CEA levels might be indicative of relatively low levels of malignant cells and a low probability of disease recurrence. This hypothesis led them to investigate whether low CEA levels in serum represented a useful prognostic factor for patients with pathologic Stage IA nonsmall cell lung carcinoma.

METHODS

Between 1993 and 2001, 724 patients underwent surgery for NSCLC at Toneyama National Hospital (Toyonaka, Japan). Of these patients, the 242 who were diagnosed with pathologic Stage IA disease were included in the current study. Smoking behavior, gender, age, tumor diameter, disease histology, and preoperative and postoperative serum CEA levels were chosen as study variables, with the cutoff level between subnormal and normal serum CEA levels set at 2.5 ng/mL and the cutoff level between normal and high serum CEA levels set at 5.0 ng/mL. Prognostic indicators were evaluated using a Cox hazard model. In addition, survival probabilities were calculated using the Kaplan–Meier method, and differences in survival were assessed by log‐lank analysis.

RESULTS

Subnormal postoperative serum CEA levels were found to be an independent prognostic indicator (hazard ratio, 2.3; 95% confidence interval, 1.1–4.7; P = 0.03 for comparison with patients who had normal CEA levels) on multivariate analysis. Furthermore, the 5‐year survival rate was 87% for patients with subnormal postoperative CEA levels (n = 146), compared with 75% for patients with normal postoperative CEA levels (n = 80) and 53% for patients with high postoperative CEA levels (n = 16) (P < 0.0001).

CONCLUSIONS

Among patients with pathologic Stage IA NSCLC, those who had an extremely favorable prognosis were distinguished by their subnormal postoperative serum CEA levels. Cancer 2004. © 2004 American Cancer Society.
Near complete surgical resection predicts a favorable outcome in pediatric patients with nonbrainstem, malignant gliomas
Authors: Bucci Mary Kara , Maity Amit , Janss Anna J. , Belasco Jean B. , Fisher Michael J. , Tochner Zelig A. , Rorke Lucy , Sutton Leslie N. , Phillips Peter C. , Shu Hui‐Kuo G.
Published: July 2004

BACKGROUND

Because few reports on outcome in patients with pediatric malignant gliomas during the magnetic resonance imaging era were available, the authors studied the outcomes of children with these tumors at their institution.

METHODS

The medical records of 39 patients with nonbrainstem, malignant gliomas who were treated at the Hospital of the University of Pennsylvania/Children's Hospital of Philadelphia between February 1, 1989 and December 31, 2000 were reviewed retrospectively. Magnetic resonance imaging was used to assess tumors at presentation and at follow‐up. Progression‐free survival (PFS) and overall survival (OS) were determined using the Kaplan–Meier method. Univariate and multivariate analyses were performed using a Cox proportional hazards model.

RESULTS

The median follow‐up for the 14 surviving patients was 47.6 months. The median PFS for all patients was 12.2 months, and the median OS for all patients was 21.3 months. The extent of surgery was the strongest prognostic factor for predicting outcomes in these patients, with a median survival of 122.2 months in patients who underwent macroscopic total resection compared with 14.1 months in patients who had significant residual disease after surgery. In univariate analyses, other than the extent of surgery, only the absence of visual symptoms at diagnosis significantly predicted improved OS. Local control was improved for patients who underwent better resection and had smaller tumors. In multivariate analyses, although the extent of surgery continued to predict outcomes significantly, histologic grade, which was not significant in the univariate analysis, also was significant.

CONCLUSIONS

Children with malignant gliomas appeared to fare better than their adult counterparts. Because the extent of resection was one of the strongest predictors of outcome, the authors concluded that the optimal therapy for these patients would include the maximal possible resection. Cancer 2004. © 2004 American Cancer Society.
Phase II trial of dose‐dense paclitaxel, cisplatin, 5‐fluorouracil, and leucovorin with filgrastim support in patients with squamous cell carcinoma of the head and neck
Authors: Hitt Ricardo , Jimeno Antonio , Millán Jose María , Castellano Daniel , Cortés‐Funes Hernán
Published: July 2004

BACKGROUND

The current study evaluated the feasibility and clinical activity of a combination of paclitaxel, cisplatin, 5‐fluorouracil (5‐FU), and leucovorin administered on a biweekly schedule to patients with recurrent or unresectable squamous cell carcinoma of the head and neck (HNSCC).

METHODS

Patients with recurrent or unresectable HNSCC were eligible if they had received a previous regimen of neoadjuvant chemotherapy, concurrent chemoradiotherapy, or no previous systemic therapy. Patients received paclitaxel (175 mg/m2 on Day 1), cisplatin (35 mg/m2 on Days 1 and 2), leucovorin (200 mg/m2 on Day 1), and 5‐FU (1000 mg/m2 per day as a 48‐hour continuous intravenous infusion on Days 1 and 2) every 2 weeks. Patients received subcutaneous filgrastim (300 μg per day) on Days 3–9 of each cycle. Treatment was administered on an outpatient basis for a maximum of six cycles.

RESULTS

Thirty‐five patients received a combined total of 194 treatment cycles. Eighteen complete responses (51%) and 12 partial responses (34%) were documented, for an overall response rate of 86% (30 of 35 patients). The median progression‐free survival duration was 14 months, and the median overall survival duration was 18 months. Two toxicity‐related deaths were documented (one due to neutropenic sepsis and the other due to catheter‐related pulmonary embolism). Grade 4 neutropenia was observed in one patient. Other severe (Grade 3 or 4) toxic effects included mucositis (14%), anemia (6%), thrombosis (6%), thrombocytopenia (3%), and neuropathy (3%).

CONCLUSIONS

The current dose‐dense, four‐agent, taxane‐containing biweekly schedule was feasible and effective in patients with recurrent or unresectable HNSCC. However, given the single‐center nature of the current study and the highly selected study population, further validation of these findings is recommended. Cancer 2004. © 2004 American Cancer Society.
Prostate‐specific antigen: A review of the validation of the most commonly used cancer biomarker
Authors: Hernández Javier , Thompson Ian M.
Published: July 2004

BACKGROUND

The widespread use of prostate‐specific antigen (PSA) screening has had a tremendous impact on all aspects of the management of prostate carcinoma. Although PSA‐based screening has resulted in a stage migration to more organ‐confined tumors at the time of diagnosis, and has been temporally associated with a decrease in prostate carcinoma mortality, PSA screening is imperfect. A recent analysis of results from the Prostate Cancer Prevention Trial (PCPT) has provided insight into the positive predictive value of PSA in the so‐called “normal” range.

METHODS

The history of the discovery, initial studies, and subsequent widespread application of PSA screening is reviewed.

RESULTS

The application of PSA for screening preceded the development of current prostate biopsy techniques and an upper limit of normal was established without complete disease ascertainment. More recent modifications of PSA‐based screening have been adopted clinically without sufficient validation. With current methods, overdiagnosis of clinically unimportant disease almost certainly occurs and high‐grade, aggressive disease may not be detected sufficiently early to allow successful treatment.

CONCLUSIONS

To the authors' knowledge, the optimal upper limit of normal for PSA for prostate carcinoma screening is unknown. New biomarkers of disease are needed; these must be linked with disease prognosis and must be validated in rigorously designed clinical trials. Cancer 2004. © 2004 American Cancer Society.
Effects of limb exercise after spinal cord injury on motor neuron dendrite structure
Authors: Gazula Valeswara‐Rao , Roberts Melinda , Luzzio Christopher , Jawad Abbas F. , Kalb Robert Gordon
Published: July 2004

An integration center subserving locomotor leg movements resides in the upper lumbar spinal cord. If this neuronal network is preserved after a spinal cord injury, it is possible to stimulate this circuitry to initiate and promote walking. The several effective approaches (electrical stimulation, pharmacologic agents, physical therapy training programs) may all share a common modus operandi of altering synaptic activity within segmental spinal cord. To understand the neural substrate for the use‐dependent behavioral improvement, we studied the dendritic architecture of spinal motor neurons. In the first experiment, we compared three groups of animals: animals with an intact spinal cord, animals that had a complete spinal cord transection (SCT) and animals with SCT who engaged in a daily exercise program of actively moving paralyzed hindlimbs through the motions of walking. When compared with animals with an intact spinal cord, the motor neurons from animals with SCT displayed marked atrophy, with loss of dendritic membrane and elimination of branching throughout the visible tree within transverse tissue slices. None of these regressive changes were found in the motor neurons from SCT animals that underwent exercise. In a second experiment, we inquired whether exercise of animals with an intact spinal cord influenced dendrite structure. Increased exercise had very modest effects on dendrite morphology, indicating an upper limit of use‐dependent dendrite growth. Our findings suggest that the dendritic tree of motor neurons deprived of descending influences is rapidly pruned, and this finding is not observed in motor neurons after SCT if hindlimbs are exercised. The functional benefits of exercise after SCT injury may be subserved, in part, by stabilizing or remodeling the dendritic tree of motor neurons below the injury site. J. Comp. Neurol. 476:130–145, 2004. © 2004 Wiley‐Liss, Inc.
Target‐specific differences in somatodendritic morphology of layer V pyramidal neurons in rat motor cortex
Authors: Gao Wen‐Jun , Zheng Ze‐Hui
Published: July 2004

Dendritic geometry has been shown to be a critical determinant of information processing and neuronal computation. However, it is not known whether cortical projection neurons that target different subcortical nuclei have distinct dendritic morphologies. In this study, fast blue retrograde tracing in combination with intracellular Lucifer yellow injection and diaminobenzidine (DAB) photoconversion in fixed slices was used to study the morphological features of corticospinal, corticostriatal, and corticothalamic neurons in layer V of rat motor cortex. Marked differences in the distribution of soma, somal size, and dendritic profiles were found among the three groups of pyramidal neurons. Corticospinal neurons were large, were located in deep layer V, and had the most expansive dendritic fields. The apical dendrites of corticospinal pyramidal neurons were thick, spiny, and branched. In contrast, nearly all corticostriatal neurons were small cells located in superficial layer V. Their apical dendritic shafts were significantly more slender, though spiny like those of corticospinal neurons. Corticothalamic neurons, which were located in superficial layer V and in layer VI, had small or medium‐sized soma, slender apical dendritic shafts, and dendrites that were largely spine free. This study indicates that, in layer V of rat motor cortex, each population of projection neurons has a unique somatodendritic morphology and suggests that distinct modes of cortical information processing are operative in corticospinal, corticostriatal, and corticothalamic neurons. J. Comp. Neurol. 476:174–185, 2004. © 2004 Wiley‐Liss, Inc.
Past success and convergent thinking in groups: The role of group‐focused attributions
Authors: Goncalo Jack A.
Published: July 2004

Past success often causes groups to think narrowly around strategies that have worked in the past, even when environmental change has rendered these strategies ineffective. From a psychological perspective, this research seems to indicate that past success may give rise to convergent thinking in groups. Why might successful groups be prone to convergent thinking? I argue that the relationship between past success and convergent thinking may depend on the attributions that groups generate to explain their shared success. In this paper, I focus on two distinct attributions at the group level: Individual‐focused attributions that reflect the idiosyncratic characteristics of individual group members and group‐focused attributions that reflect the emergent properties of the group as a whole. I found that group‐focused attributions for past success cause groups to generate fewer ideas that are, on average, more convergent. In contrast, individual‐focused attributions cause groups to generate more ideas that are on average more divergent. These findings suggest that the experience of success may actually stimulate divergent thinking depending on how a group chooses to explain it. Copyright © 2004 John Wiley & Sons, Ltd.
Identifying good opportunities to act: Implementation intentions and cue discrimination
Authors: Webb Thomas L. , Sheeran Paschal
Published: July 2004

Forming an implementation intention (‘If I encounter situation X, then I'll perform behaviour Y!’) is thought to increase the likelihood that the person will detect a good opportunity to act. Experiment 1 found support for this hypothesis in a novel context where detection of the specified cue was very difficult. Experiments 2 and 3 extended existing paradigms to test whether this improved cue detection has costs in terms of increased false positives and/or slower responses to ambiguous stimuli. This hypothesis was not supported. Forming an implementation intention led to more accurate (Experiment 2) and faster (Experiment 3) responses to the specified cue without compromising responses to non‐relevant, or ambiguous, stimuli. Overall, the findings suggest that forming an implementation intention is an effective self‐regulatory tool because the specified cues are discriminated swiftly and with precision. Copyright © 2004 John Wiley & Sons, Ltd.
Task engagement after mortality salience: The effects of creativity, conformity and connectedness on worldview defence
Authors: Routledge Clay , Arndt Jamie , Sheldon Kennon M.
Published: July 2004

Terror management research has shown that activating thoughts about mortality (mortality salience) increases defence of one's worldview. This study investigated how worldview defence is affected by engaging in a task that fosters creativity, conformity, or sharing values after being reminded of death. After writing about death or a control topic, participants were randomly assigned to design a t‐shirt with the goal of being as creative as possible, trying to please others but not oneself, or trying to connect with others via shared values. After mortality salience, conforming to others led to increased worldview defence whereas sharing values did not. Further, engaging in a creative task decreased worldview defence after mortality salience. Implications for understanding the interface between different forms of social connectedness, creativity and the management of existential fears are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Upset in response to a child's partner's infidelities
Authors: Shackelford Todd K. , Michalski Richard L. , Schmitt David P.
Published: July 2004

The weight of existing evidence suggests that men display greater upset in response to a long‐term partner's sexual infidelity, whereas women display greater upset in response to a partner's emotional infidelity. This sex difference was first hypothesized by evolutionary psychologists, who argued that the difference may reflect sex‐differentiated evolved psychological design. Some socialization theorists, in contrast, have argued that the difference may be attributable to sex‐differentiated socialization practices. A. Fenigstein and R. Peltz (2002) collected data from parents of undergraduates about upset in response to a child's partner's infidelities and found that both sexes report greater upset in response to a son's partner's sexual infidelity and in response to a daughter's partner's emotional infidelity. The key variable therefore is the sex of the child, as predicted from a heuristic application of an evolutionary perspective, and not the sex of the parent, as predicted from a heuristic application of one socialization perspective. We report a replication of these findings using data collected from retirees with an average age of about 70 years who have at least one son and one daughter and most of whom have grandchildren. Copyright © 2004 John Wiley & Sons, Ltd.
EEG and the Test for the Early Detection of Dementia with Discrimination from Depression (TE4D): a validation study
Authors: Brinkmeyer Jürgen , Grass‐Kapanke Brigitte , Ihl Ralf
Published: July 2004

Objective

The Test for the Early Detection of Dementia with Discrimination from Depression (TE4D) was developed as a screening instrument for mild dementia. We investigated the convergent validity of the TE4D to EEG and other psychometric tests in patients suffering from dementia and depression.

Method

In 47 patients suffering from Alzheimer's disease (ICD‐10 F.00) and 16 patients with affective disorders (F30‐F39) the tests TE4D, ADAS‐cog, SKT, BCRS, MMSE were performed and an EEG recorded. Group differences were compared by t‐tests and a regression analysis was calculated.

Results

The inter‐test‐correlations varied between rs = 0.77 and rs = 0.91. Significant differences between the diagnostic groups were found for all tests as well as for the frequency bands α and β. For the qEEG, significant positive correlations were found between TE4D (Dementia subscore) and the mean frequency (r = 0.47), the peak frequency (r = 0.42), the frequency bands α (r = 0.59) and β (r = 0.56) as well as negative correlations in the frequency bands δ (r = −0.23) and ϑ (r = −0.42). The mean frequency and the activity in the frequency bands α, β2, δ and ϑ contributed to the regression equation. The correlation between regression equation and the TE4D was rs = 0.87. The other tests also correlated with the TE4D: ADAS rs = −0.75, MMST rs = 0.82, SKT rs = −0.74, BCRS rs = −0.83.

Conclusion

The TE4D showed convergent validity with the EEG parameters. Both the TE4D‐score and the EEG‐alterations correlated significantly with the degree of severity of Alzheimer's disease. This result underlines the assumption that the TE4D will be a useful instrument for the diagnostic process in dementia. Copyright © 2004 John Wiley & Sons, Ltd.
Mechanism of action of the antifibrogenic compound gliotoxin in rat liver cells
Authors: Orr James G. , Leel Val , Cameron Gary A. , Marek Carylyn J. , Haughton Emma L. , Elrick Lucy J. , Trim Julie E. , Hawksworth Gabrielle M. , Halestrap Andrew P. , Wright Matthew C.
Published: July 2004

Gliotoxin has been shown to promote a reversal of liver fibrosis in an animal model of the disease although its mechanism of action in the liver is poorly defined. The effects of gliotoxin on activated hepatic stellate cells (HSCs) and hepatocytes have therefore been examined. Addition of gliotoxin (1.5 μM) to culture-activated HSCs resulted in its rapid accumulation, resulting in increased levels of glutathione and apoptosis without any evidence of oxidative stress. In contrast, although hepatocytes also rapidly sequestered gliotoxin, cell death only occurred at high (50-μM) concentrations of gliotoxin and by necrosis. At high concentrations, gliotoxin was metabolized by hepatocytes to a reduced (dithiol) metabolite and glutathione was rapidly oxidized. Fluorescent dye loading experiments showed that gliotoxin caused oxidative stress in hepatocytes. Antioxidants—but not thiol redox active compounds—inhibited both oxidative stress and necrosis in hepatocytes. In contrast, HSC apoptosis was not affected by antioxidants but was potently abrogated by thiol redox active compounds. The adenine nucleotide transporter (ANT) is implicated in mitochondrial-dependent apoptosis. HSCs expressed predominantly nonliver ANT isoform 1, and gliotoxin treatment resulted in a thiol redox-dependent alteration in ANT mobility in HSC extracts, but not hepatocyte extracts. In conclusion, these data suggest that gliotoxin stimulates the apoptosis of HSCs through a specific thiol redox-dependent interaction with the ANT. Further understanding of this mechanism of cell death will aid in finding therapeutics that specifically stimulate HSC apoptosis in the liver, a promising approach to antifibrotic therapy. Supplementary material for this article can be found on the Hepatology website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (Hepatology 2004;40:232-242.)
A phase II dose-escalating trial of clevudine in patients with chronic hepatitis B
Authors: Marcellin Patrick , Mommeja-Marin Herve , Sacks Stephen L. , Lau George K. K. , Sereni Daniel , Bronowicki Jean-Pierre , Conway Brian , Trepo Christian , Blum Robert M. , Yoo Byung Chul , Mondou Elsa , Sorbel Jeff , Snow Andrea , Rousseau Franck , Lee Hyo-Suk
Published: July 2004

Current therapies available for the treatment of chronic hepatitis B are limited in their ability to result in a cure. Clevudine is a new pyrimidine analog with potent anti-hepatitis B virus (HBV) activity in vitro. A multicenter dose-escalation study evaluated clevudine at 10, 50, 100, and 200 mg once daily for 28 days. Eligible patients had HBV DNA levels of 3 × 106 copies/mL or more, had not undergone nucleoside treatment, and were without human immunodeficiency or hepatitis C virus coinfection. Thirty-two patients were enrolled (5, 10, 10, and 7 patients in the 10-, 50-, 100-, and 200-mg dose groups, respectively), 81% were male, 81% Asian, and 88% were hepatitis Be antigen (HBeAg) positive at baseline. Median pretreatment serum HBV DNA levels ranged from 7.3 to 8.8 log10 copies/mL. After 28 days, the median HBV DNA log10 change from baseline was −2.5, −2.7, −3.0, and −2.6 log10. Six months after dosing, median changes from baseline were −1.2, −1.4, −2.7 and −1.7 log10 in the 10-, 50-, 100-, and 200-mg cohorts, respectively. Six of 27 patients lost HBeAg, and 3 of 27 patients seroconverted to HBe antibody. Clevudine was well tolerated, with no dose-limiting toxicities. A transient increase in alanine aminotransferase of up to 7.8 times the upper limit of normal (increase ranged from 20 to 186 IU/L) was observed in six patients in the 100-mg cohort, without signs of liver failure. These increases were associated with improved viral suppression. The pharmacokinetic profile of clevudine was proportional to the dose. In conclusion, these results demonstrate the tolerability and potent activity of clevudine in HBV-infected patients and support further clinical study. (Hepatology 2004;40:140-148.)
Comparison of HCV-specific intrahepatic CD4+ T cells in HIV/HCV versus HCV†
Authors: Graham Camilla S. , Curry Michael , He Qi , Afdhal Nezam , Nunes David , Fleming Catherine , Horsburgh Robert , Craven Donald , Sherman Kenneth E. , Koziel Margaret James
Published: July 2004

Persons with human immunodeficiency virus (HIV) and hepatits C virus (HCV) coinfection are at increased risk for progression to cirrhosis compared with persons with HCV alone, but the reasons for this are unclear. In chronic HCV, the mechanism of liver injury is presumed to be due to HCV-specific T cell destruction of hepatocytes, so it is paradoxical that immunosuppressed hosts have higher rates of fibrosis progression. We examined intrahepatic cellular immune responses to HCV antigens to determine whether there were qualitative or quantitative differences in subjects with and without HIV. Expanded, CD4-enriched, liver-infiltrating lymphocytes from 18 subjects with chronic HCV and 12 subjects with HIV/HCV were cultured in the presence of HCV core protein, nonstructural proteins NS3 and NS5, and recall antigens tetanus toxoid and Candida. Secretion of interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), and interleukin (IL) 10 was determined using enzyme-linked immunosorbent spot assay. There were no significant differences in liver biopsy grade or stage for HIV/HCV versus HCV groups. There were no significant differences between groups in the secretion of IFN-γ or TNF-α in response to HCV or recall antigens. However, there was a significant increase in IL-10 secretion in response to NS3 and NS5 in subjects with HCV compared with HIV and HCV coinfection. In conclusion, subjects with coinfection have an alteration of intrahepatic HCV-specific IL-10 cytokine response that may have implications for HCV-related disease progression. (Hepatology 2004;40:125-132.)