bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant lipases: Biocatalyst aqueous environment in relation to optimal catalytic activity in lipase‐catalyzed synthesis reactions
Authors: Caro Yanis , Pina Michel , Turon Fabrice , Guilbert Stephane , Mougeot Estelle , Fetsch David V. , Attwool Philip , Graille Jean
Published: August 2002

Adsorption and desorption isotherms of two commercial enzyme preparations of papain and bromelain were determined with a Dynamic Vapor System. The Guggenheim‐Anderson‐deBoer (GAB) modeling of the obtained sorption isotherms allowed the definition of different levels of hydration of those samples. Afterward, these enzyme preparations were used as biocatalysts in water and solvent‐free esterification and alcoholysis reactions. The evolution of the obtained fatty acid ester level as a function of the initial hydration level of the biocatalyst, i.e., thermodynamic water activity (aw) and water content, was studied. The results show an important correlation between the initial hydration level of the biocatalyst and its catalytic activity during the lipase‐catalyzed synthesis reactions. Thus, the Carica papaya lipase (crude papain preparation) catalytic activity is highly dependent on the biocatalyst hydration state. The optimized synthesis reaction yield is obtained when the aw value of the enzyme preparation is stabilized at 0.22, which corresponds to 2% water content. This optimal level of hydration occurs on the linear part of the biocatalyst's sorption isotherm, where the water molecules can form a mono‐ or multiple layer with the protein network. The synthesis reaction yield decreases when the aw of the preparation is higher than 0.22, because the excess water molecules modify the system equilibrium leading to the reverse and competitive reaction, i.e., hydrolysis. These results show also that an optimal storage condition for the highly hydrophilic crude papain preparation is a relative humidity strictly lower than 70% to avoid an irreversible structural transition leading to a useless biocatalyst. Concerning the bromelain preparation, no effect of the hydration level on the catalytic activity during esterification reactions was observed. This biocatalyst has too weak a catalytic activity which makes it difficult to observe any differences. Furthermore, the bromelain preparation is far more hydrophobic as it adsorbs only 18 g of water per 100 g of dry material at aw around 0.90. No deliquescence of this enzymatic preparation is oserved at this aw value. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 693–703, 2002; DOI 10.1002/bit.10155
Estimation of hyphal tensile strength in production‐scale Aspergillus oryzae fungal fermentations
Authors: Li Zheng Jian , Shukla Vivek , Wenger Kevin , Fordyce Andrew , Pedersen Annemarie Gade , Marten Mark
Published: August 2002

Fragmentation of filamentous fungal hyphae depends on two phenomena: hydrodynamic stresses, which lead to hyphal breakage, and hyphal tensile strength, which resists breakage. The goal of this study was to use turbulent hydrodynamic theory to develop a correlation that allows experimental data of morphology and hydrodynamics to be used to estimate relative (pseudo) tensile strength (σpseudo) of filamentous fungi. Fed‐batch fermentations were conducted with a recombinant strain of Aspergillus oryzae in 80 m3 fermentors, and measurements were made of both morphological (equivalent hyphal length, L) and hydrodynamic variables (specific power input, $\bar \varepsilon$; kinematic viscosity, v). We found that v increased over 100‐fold during these fermentations and, hence, Kolmogorov microscale (λ) also changed significantly with time. In the impeller discharge zone, where hyphal fragmentation is thought to actually take place, λ was calculated to be 700–3500 μm, which is large compared to the size of typical fungal hyphae (100–300 μm). This result implies that eddies in the viscous subrange are responsible for fragmentation. Applying turbulent theory for this subrange, it was possible to calculate σpseudo from morphological and hydrodynamic measurements. Pseudo tensile strength was not constant but increased to a maximum during the first half and then decreased during the second half of each fermentation, presumably due to differences in physiological state. When a literature correlation for hyphal fragmentation rate (kfrag) was modified by adding a term to account for viscosity and tensile strength, the result was better qualitative agreement with morphological data. Taken together, these results imply hyphal tensile strength can change significantly over the course of large‐scale, fed‐batch fungal fermentations and that existing fragmentation and morphology models may be improved if they accounted for variations in hyphal tensile strength with time. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 601–613, 2002; DOI 10.1002/bit.10209
Modeling of the enzymatic kinetic synthesis of cephalexin—Influence of substrate concentration and temperature
Authors: Schroën C. G. P. H. , Nierstrasz V. A. , Moody H. M. , Hoogschagen M. J. , Kroon P. J. , Bosma R. , Beeftink H. H. , Janssen A. E. M. , Tramper J.
Published: August 2002

During enzymatic kinetic synthesis of cephalexin, an activated phenylglycine derivative (phenylglycine amide or phenylglycine methyl ester) is coupled to the nucleus 7‐aminodeacetoxycephalosporanic acid (7‐ADCA). Simultaneously, hydrolysis of phenylglycine amide and hydrolysis of cephalexin take place. This results in a temporary high‐product concentration that is subsequently consumed by the enzyme. To optimize productivity, it is necessary to develop models that predict the course of the reaction. Such models are known from literature but these are only applicable for a limited range of experimental conditions.

In this article a model is presented that is valid for a wide range of substrate concentrations (0–490 mM for phenylglycine amide and 0–300 mM for 7‐ADCA) and temperatures (273–298 K). The model was built in a systematic way with parameters that were, for an important part, calculated from independent experiments. With the constants used in the model not only the synthesis reaction but also phenylglycine amide hydrolysis and cephalexin hydrolysis could be described accurately. In contrast to the models described in literature, only a limited number (five) of constants was required to describe the reaction at a certain temperature. For the temperature dependency of the constants, the Årrhenius equation was applied, with the constants at 293 K as references. Again, independent experiments were used, which resulted in a model with high statistic reliability for the entire temperature range. Low temperatures were found beneficial for the process because more cephalexin and less phenylglycine is formed.

The model was used to optimize the reaction conditions using criteria such as the yield on 7‐ADCA or on activated phenylglycine. Depending on the weight of the criteria, either a high initial phenylglycine amide concentration (yield on 7‐ADCA) or a high initial 7‐ADCA concentration (yield on phenylglycine amide) is beneficial. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 171–178, 2001.
Wet extrusion of fibronectin–fibrinogen cables for application in tissue engineering
Authors: Underwood S. , Afoke A. , Brown R. A. , MacLeod A. J. , Shamlou P. Ayazi , Dunnill P.
Published: August 2002

A method for the wet extrusion of human plasma‐derived fibronectin–fibrinogen cables is described. Solutions of fibronectin and fibrinogen with and without sodium alginate and carboxymethylcellulose (CMC) are tested. The rheological properties of the protein solutions changed from Newtonian to shear thinning non‐Newtonian in the presence of small quantities of these additives, the apparent viscosity increased, and the extrusion properties of the protein solutions improved. Cables were prepared using a capillary with a diameter of 1 mm and overall length of 18 mm. Cable diameter was reduced to about 0.5 mm by drawing using a series of rollers. Cables prepared with sodium alginate were found to have suitable properties, and those made with CMC were sticky and difficult to handle. Solutions containing no sodium alginate required a minimum total protein concentration of about 70 mg/mL for extrusion. Extruded cables were prepared with solutions containing 140 mg/mL total protein with 12.9 mg/mL alginate (high protein), and 46 mg/mL total protein with 47.6 mg/mL of sodium alginate (high alginate). The mechanical strength of the extruded cables was within the range suitable for application in tissue engineering. Extrusion of the protein solutions into cables was achieved in a coagulation bath. Cables with a mechanical strength of approximately 30 N/mm2, suitable for wound repair and nerve regeneration applications, were prepared with a coagulation bath containing 0.25 M HCl, 2% CaCl2 at a pH of <0.9. These cables also had a large average elongation at break of 52%, and showed an increase in cable length after breakage (permanent set) of 20%, demonstrating the potential for drawing the cables down to a fine diameter. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 295–305, 2001.
Substrate controlled development of anaerobic acidifying aggregates at different shear rates in a gas lift reactor
Authors: Verschuren Peter G. , van den Heuvel Johannes C.
Published: August 2002

The influence of liquid shear rates on the development of acidifying mixed‐culture aggregates was studied in a gas‐lift reactor. The glucose concentration was kept at a constant and relatively high level by operating the reactor in pH‐auxostat mode. Size, strength, and wet density of aggregates cultivated at different superficial gas velocities (Ug) were investigated. Image analysis showed that the Sauter mean diameter (Ds) decreased with increasing Ug. A stirred tank was used to characterize the surface detachment rate (Rd) under non‐growth conditions. An exponential decrease was observed in Rd with the applied Ug during cultivation, i.e., aggregates became stronger. The increased strength coincided with an increase in aggregate wet density. Size classified aggregates showed an increase in Rd with the square of the aggregate diameter (Dp), however, this contribution was much smaller than the effect of adaptation. Experiments in a similar gas‐lift reactor under dynamic conditions without adaptation, showed that Rd increased exponentially with increasing Ug. So, two important contributions to Rd can be distinguished: adaptation, which induces stronger aggregates, and aggregate size, which makes them less susceptible to hydrodynamic shear. A general expression for Rd was derived, which depends on Dp and Ug. Combining this equation with the surface biomass growth rate (Rg) allowed for the estimation of the maximal diameter (Dmax) aggregates can reach at any Ug, and it was found that the estimated and measured Dmax were in good agreement. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 306–315, 2002.
Separation of cephalosporins on thin silica gel layers impregnated with transition metal ions and by reversed‐phase TLC
Authors: Bhushan Ravi , Thiong'o G. Thuku
Published: August 2002

Cephalosporin antibiotics were separated on thin layer plates impregnated with transition metal ions, Mn2+, Fe2+, Co2+, Ni2+ and Cu2+, using different concentrations. Various solvent systems were developed for the study and were used for separation of these analytes. Impregnation was observed to have an effect on hRF values, removed tailing of analytes and improved the resolution. The results have been discussed for each metal ion and compared, and the best conditions of separation have been identified. Activation time of thin layer plates impregnated with 0.1% FeSO4 was found to affect both hRF values and resolution of cephalosporins. New solvent systems are reported for both normal phase and reversed‐phase TLC. Copyright © 2002 John Wiley & Sons, Ltd.
Determination of captopril in biological samples by high‐performance liquid chromatography with ThioGlo™3 derivatization
Authors: Aykin Nukhet , Neal Rachel , Yusof Mozow , Ercal Nuran
Published: August 2002

Captopril, a well‐known angiotensin converting enzyme (ACE) inhibitor, is widely used for treatment of arterial hypertension. Recent studies suggest that it may also act as a scavenger of free radicals because of its thiol group. Therefore, the present study describes a rapid, sensitive and relatively simple method for the detection of captopril in biological tissues with reverse‐phase HPLC. Captopril was first derivatized with ThioGlo™3 [3H‐Naphto[2,1‐b]pyran,9‐acetoxy‐2‐(4‐(2,5‐dihydro‐2,5‐dioxo‐1H‐pyrrol‐1‐yl)phenyl‐3‐oxo‐)]. It was then detected by fluorescence‐HPLC using an Astec C18 column as the stationary phase and a water:acetonitrile:acetic acid:phosphoric acid mixture (50:50; 1 mL/L acids) as the mobile phase (excitation wavelength, 365 nm; emission wavelength, 445 nm). The calibration curve for captopril was linear over a range of 10–2500 nM and the coefficient of variation acquired for the within‐ and between‐run precision for captopril was 0.5 and 3.8%, respectively. The detection limit of captopril with this method was found to be 200 fmol/20 µL injection volume. Its relative recovery from biological samples was determined to the range from 93.3 to 105.3%. Based on these results, we believe that our method is advantageous for captopril determination. Copyright © 2001 John Wiley & Sons, Ltd.

Abbreviations used:

ACE

angiotensin converting enzyme

PBPB

P‐bromophenylbromide

ROS

reactive oxygen species
Influence of oxidation and crosslinking on oxygen binding properties of mouse erythrocytes
Authors: Lotero L. A. , Jordán J. A. , López R. M. , García‐Pérez A. I. , Diez J. C.
Published: August 2002

Different chemical treatments for mouse erythrocyte modification has been used. Oxidation treatments with Ascorbate/Fe3+, a system able to react with intracellular proteins, produced a displacement of the O2 binding equilibrium curve to a higher affinity behaviour with loss of the haemoglobin cooperativity for oxygen binding. Incubation of mouse erythrocytes with diamide showed that at low reagent concentration (0.8 mM) no modification on oxygen binding equilibrium curves was observed. At higher reagent concentration (2.0 mM), an increased affinity and a disappearance of the cooperative behaviour can be observed. Additionally, crosslinking reactions on mouse erythrocytes with band 3 crosslinkers seemed to affect oxygen binding properties when used at a crosslinker concentration of 5 mM. Oxyhaemoglobin levels in crosslinked and diamide‐treated erythrocytes are similar to those found in control cells. In contrast, ascorbate/Fe3+ treatments produced an increment in the proportion of methaemoglobin, decreasing the oxyhaemoglobin levels in these oxidized erythrocytes. Copyright © 2001 John Wiley & Sons, Ltd.
Postoperative coronary revascularization on LVAD support for surgically inaccessible myocardial ischemia
Authors: Kollar Andras , Misra Vijay , Pierson Richard N.
Published: August 2002

The authors have used the concept of hybrid revascularization to salvage a patient in persistent cardiogenic shock after incomplete emergent surgical revascularization. While the patient was on left ventricular assist device support, a complex angioplasty was done on a surgically inaccessible right coronary artery, with subsequent cardiac recovery. Cathet Cardiovasc Intervent 2002;55:381–384. © 2002 Wiley‐Liss, Inc.
Claeys MJ, Bosmans JM, Hendrix J, Vrints CJ. Reliability of fractional flow reserve measurements in patients with associated microvascular dysfunction: Importance of flow on translesional pressure gradient. Cathet Cardiovasc Intervent 2001;54:427–434
Authors: Claey MJ , Bosmans JM , Hendrix J , Vrints CJ
Published: August 2002

The original article to which this Erratum refers was published in Catheterization and Cardiovascular Interventions; 2002; 54(4) 427–434
Transcatheter recanalization of the left main pulmonary artery after four years of complete occlusion
Authors: Fink Christoph , Peuster Matthias , Bertram Harald , Hausdorf Gerd
Published: August 2002

A technique for transcatheter “reconstruction” of a completely occluded left pulmonary artery using radiofrequency perforation with subsequent balloon dilation and stent implantation is reported in a 7‐year‐old child. It is shown that transcatheter radiofrequency perforation can still be effective years after the occlusion of a vessel. Cathet Cardiovasc Intervent 2001;53:81–84. © 2001 Wiley‐Liss, Inc.
Standalone cutting balloon angioplasty for the treatment of stent‐related restenosis: Acute results and 3‐ to 6‐month angiographic recurrent restenosis rates
Authors: Miyamoto Takamichi , Araki Takao , Hiroe Michiaki , Marumo Fumiaki , Niwa Akihiro , Yokoyama Koichi
Published: August 2002

Despite excellent acute reperfusion results, 20%–30% of patients who undergo coronary stent implantation will develop angiographic restenosis and may require same additional treatments. Cutting Balloon angioplasty (CBA) causes less histological damage outside of the incised area than a regular balloon. However, regular plain old balloon angioplasty is sometimes required before CBA, as is adjunctive stenting and adjunctive angioplasty. These adjunctive strategies may negate the advantages of CBA. There is little data available on CBA as a standalone therapy for stent‐related restenosis (SRS). The aim of this study was to evaluate the acute and 3‐ to 6‐month angiographic recurrent restenosis rates following standalone CBA in a patient population treated for SRS and in whom optimal acute results were obtained. In this study, 40 patients with SRS (54 lesions) underwent standalone CBA with optimal acute results. For all lesions, coronary angiography was conducted before and after a standalone CBA procedure for SRS and systematically during 3–6 months to assess recurrent angiographic restenosis rates in the study population. In the study lesions, SRS was either diffuse disease (> 15 mm; 52%) or focal type (48%). Cutting Balloon diameter was 3.20 ± 0.44 mm and maximal inflation pressure 8.7 ± 1.2 atm. Ratio of Cutting Balloon diameter to restenotic stent diameter was 0.996 ± 0.487. Multiple inflations (6 ± 3 times) were performed. Number of used Cutting Balloon was 1.02 ± 0.14. Complications were as follows; one non–Q‐wave MI (1.9%); 0 death (0%), and 17 repeat target lesion revascularizations (TLRs; 32%). Follow‐up coronary angiography (CAG) was not attained for one patient. The angiographic recurrent restenosis rate was 34%, with a higher rate observed when the SRS was diffuse type, 50% vs. 16% for focal‐type SRS (P < 0.01). The recurrent restenosis rate for smaller vessels (vessel diameter ≤ 3.0 mm) was the same as for larger ones. At follow‐up CAG, diffuse‐type recurrent restenosis (56%) presented nearly as frequently as that presenting in the original SRS lesions (52%). But four diffuse‐type SRS (29%) changed into focal‐type recurrent stenosis. In this study, standalone CBA for SRS with optimal acute results was associated with an angiographic restenosis rate of 34%. Diffuse‐type disease had a higher recurrent restenosis rate. When CBA achieves acute optimal results, adjunctive stenting or adjunctive PTCA are not always necessary, particularly when the SRS is focal. As a result of CBA, some diffuse‐type SRS may change into focal‐type recurrent stenosis by the time of the next intervention. Cathet Cardiovasc Intervent 2001;54:301–308. © 2001 Wiley‐Liss, Inc.
Determination of the absolute configuration of a key tricyclic component of a novel vasopressin receptor antagonist by use of vibrational circular dichroism
Authors: Dyatkin Alexey B. , Freedman Teresa B. , Cao Xiaolin , Dukor Rina K. , Maryanoff Bruce E. , Maryanoff Cynthia A. , Matthews Jay M. , Shah Rekha D. , Nafie Laurence A.
Published: August 2002

We present the results of a study using vibrational circular dichroism (VCD) for (+)‐1, which furnished an unambiguous determination of its absolute configuration as S. The most abundant conformation of (+)‐1 in CDCl3 solution was also established. Chirality 14:215–219, 2002. © 2002 Wiley‐Liss, Inc.
The challenge of completely ethical CI and the CHIP model
Authors: Charters Darren
Published: August 2002

This article examines difficulties that are present for competitive intelligence practitioners endeavoring to conduct ethical CI. It explores the basic schools of ethical thought and combines them to create a model for evaluating the ethics of potential competitive intelligence activities. It concludes by suggesting that using rigorous ethical evaluation in assessing CI activities does not have to sacrifice the competitive position of an organization. © 2001 John Wiley & Sons, Inc.
Contraction‐mediated pinocytosis of RGD‐peptide by dermal fibroblasts: Inhibition of matrix attachment blocks contraction and disrupts microfilament organisation
Authors: Sethi K. K. , Mudera V. , Sutterlin R. , Baschong W. , Brown R. A.
Published: August 2002

Force generation in collagen and matrix contraction are basic functions of fibroblasts and important elements of tissue repair. Cell‐matrix attachment is critical to this contraction, involving RGD‐binding integrins. We have investigated how this process operates, in terms of force generation (in the Culture Force Monitor) and cytoskeletal structure, using a synthetic RGD‐decapeptide. The RGD‐peptide blocked force generation over the first 6 h, followed by near complete recovery by 20 h. However, dose response was complex indicating multiple processes were operating. Analysis of cytoskeletal structure after treatment with RGD‐peptide indicated major disruption with condensed aggregates of actin and microtubular fragmentation. Fluorescent labeling and tracking of the RGD‐peptide demonstrated intracellular uptake into discrete cytoplasmic aggregates. Critically, these RGD‐peptide pools co‐localised with the condensed actin microfilament aggregates. It is concluded that RGD‐peptide uptake was by a form of contraction‐mediated pinocytosis, resulting from mechanical tension applied to the untethered RGD‐peptide‐integrin, as contractile microfilament were assembled. These findings emphasize the importance of sound mechanical attachment of ligand‐occupied integrins (e.g., to extracellular matrix) for normal cytoskeletal function. Conversely, this aspect of unrestrained cytoskeletal contraction may have important pathogenic and therapeutic applications. Cell Motil. Cytoskeleton 52:231–241, 2002. © 2002 Wiley‐Liss, Inc.
Survival by radiation therapy oncology group recursive partitioning analysis class and treatment modality in patients with brain metastases from malignant melanoma
Authors: Buchsbaum Jeffrey C. , Suh John H. , Lee Shih‐Yuan , Chidel Mark A. , Greskovich John F. , Barnett Gene H.
Published: August 2002

BACKGROUND

In a population of patients with brain metastases from melanoma, the authors sought to determine whether various therapies provided any benefit at all, whether local therapy was better than whole brain radiotherapy (WBRT), and whether combined local therapy and WBRT provided any advantage over local therapy alone. They also analyzed survival according to a Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) to determine how well the RTOG RPA classes predicted survival in this patient population and whether treatments varied in effectiveness from category to category.

METHODS

A total of 74 patients with brain metastases from melanoma were treated at The Cleveland Clinic Foundation between 1984 and 1998. For this study, the authors reviewed patient charts and confirmed survival status. Survival was compared by treatment modality (surgical resection, WBRT, stereotactic radiosurgery, or WBRT combined with local therapy). Survival also was compared according to the RTOG RPA prognostic classes (Class 1, Class 2, or Class 3), which has not been validated previously in patients with malignant melanoma.

RESULTS

The median survival was 5.5 months for all patients. Survival varied significantly by RTOG prognostic class; The median survival was 10.5 months (range, 2.2–99.2 months) for patients in Class 1, 5.9 months (range, 0.2–43.9 months) for patients in Class 2, and 1.8 months (range, 0.1–6.9 months) for patients in Class 3 (P < 0.0001). Survival analysis showed that combined treatment offered significantly better survival (P < 0.0001; combined vs. other). The median survival was 8.8 months (range, 1.8–99.2 months) for the combined therapy group, 4.8 months (range, 1.2–27.8 months) for the local therapy alone group, 2.3 months (range, 0.2–9.6 months) for the WBRT alone group, and 1.1 months (0.1–3.0 months) for the group that received no therapy.

CONCLUSIONS

Adding WBRT to local therapy may improve survival in this group of patients: Combined therapy was superior to WBRT alone. The RPA classification scheme likely has prognostic value for patients with brain metastases from malignant melanoma. Prospective studies are required to overcome selection bias and confirm these results. Cancer 2002;94:2265–72. © 2002 American Cancer Society.

DOI 10.1002/cncr.10426
Follow‐up surveillance strategies for genitourinary malignancies
Authors: Evans Christopher P.
Published: August 2002

BACKGROUND

Genitourinary cancers account for more than 20% of all malignancies in the United States. These cancers do not usually yield rapid mortality, thereby necessitating longer‐term surveillance strategies.

METHODS

A review and analysis of relevant studies were performed. Follow‐up strategies are proposed to reflect effective methods to detect recurrent prostate, bladder, renal, and testicular cancers. Cost analysis was performed using Medicare reimbursement rates.

RESULTS

For genitourinary tumors, follow‐up tests can be planned rationally based on detection rates and patterns. Tumor grade and stage drive follow‐up strategies, along with therapeutic implications of detecting a recurrence. Symptomatic recurrences often obviate the need for radiographic tests and can minimize costs. Stage‐ specific plans for these four urologic malignancies are outlined specifically.

CONCLUSIONS

Not all surveillance approaches have been critically tested for follow‐up of genitourinary tumors, but ample data are available to propose sound medical and economic strategies. Cancer 2002;94:2892–905. © 2002 American Cancer Society.

DOI 10.1002/cncr.10525
Serum tissue polypeptide specific antigen as a noninvasive prognostic indicator for early recurrence of hepatocellular carcinoma after curative resection
Authors: Yao Wei‐Jen , Wang Shan‐Tair , Chow Nan‐Haw , Chang Ting‐Tsung , Lin Pin‐Wen , Tu Dom‐Gene
Published: August 2002

BACKGROUND

Serum tissue polypeptide specific antigen (TPS) is a useful cell proliferation marker in diagnosing and monitoring patients with a variety of malignancies. The objective of this study was to determine the usefulness of serum TPS as a noninvasive prognostic factor for early recurrence of hepatocellular carcinoma (HCC) after patients undergo curative resection.

METHODS

Serum TPS levels were measured by monoclonal TPS immunoradiometric assay in 54 patients shortly before they underwent curative resection for HCC. The recurrence time was correlated with the TPS level and with other prognostic factors using the log‐rank test in univariate analysis and a Cox regression in multivariate analysis. Receiver operating characteristic analysis was performed to examine the power of the various prognostic factors to distinguish between patients with recurrent tumors and patients who were disease free.

RESULTS

Patients who had higher levels of TPS (≥ 150 U/L) had earlier recurrences compared with patients who had lower levels of TPS (< 150 U/L; P = 0.016) in univariate analysis. Tumor size, the number of tumors, portal vein invasion, and the resection margins also were associated significantly with the time to tumor recurrence (P = 0.015, P = 0.004, P = 0.003, and P = 0.003, respectively). Serum α‐fetoprotein was not a significant risk factor for tumor recurrence. In multivariate analysis, the TPS level, tumor size, and resection margins were independent prognostic factors (P = 0.025, P = 0.018, and P = 0.016, respectively). The inclusion of TPS in addition to tumor size and resection margins increased the rate of corrective prediction from 0.72 to 0.80.

CONCLUSIONS

The current study demonstrated that the preoperative serum TPS level was a significant factor in predicting early recurrence of HCC after curative resection. Patients with high serum TPS levels warrant more aggressive treatment and close follow‐up after they undergo tumor resection. Cancer 2002;95:112–8. © 2002 American Cancer Society.

DOI 10.1002/cncr.10626
Serotoninergic and noradrenergic axons make contacts with neurons of the ventral spinocerebellar tract in the cat
Authors: Hammar Ingela , Maxwell David J.
Published: August 2002

Contacts between monoaminergic fibers and electrophysiologically identified neurons of the ventral spinocerebellar tract were investigated in the cat. Five neurons were labeled intracellularly with rhodamine dextran, and monoaminergic fibers were revealed with antibodies against serotonin and dopamine beta‐hydroxylase. The distribution of appositions between monoaminergic varicosities and the soma and the whole length of dendrites of these neurons was examined by using a three‐channel confocal microscope. The analysis showed that close appositions between monoaminergic fibers and labeled processes occurred over the whole surface of the neurons. The highest percentage of such appositions was found on proximal dendrites, for both serotonin (37%) and noradrenaline (57%). The total number of serotoninergic contacts (66–134 per neuron) by far exceeded that of noradrenergic contacts (3–36 per neuron). Contacts between serotoninergic fibers and two neurons were analyzed by using electron microscopy. These neurons were labeled intracellularly with horseradish peroxidase, and serotoninergic varicosities were identified by immunocytochemistry. Six of 10 serially analyzed boutons in apposition to proximal dendrites were found to form morphologic synapses. The identification of the remaining four was inconclusive. These results indicate that many of the appositions seen in confocal microscopy may represent direct synaptic contacts. They also indicate that monoaminergic neurons may modulate activity of neurons of the ventral spinocerebellar tract by direct postsynaptic actions in addition to any effects evoked by means of volume transmission. J. Comp. Neurol. 443:310–319, 2002. © 2002 Wiley‐Liss, Inc.
Stereological analysis of Ca2+/calmodulin‐dependent protein kinase IIα‐containing dorsal root ganglion neurons in the rat: Colocalization with isolectin Griffonia simplicifolia, calcitonin gene‐related peptide, or vanilloid receptor 1
Authors: Carlton Susan M. , Hargett Gregory L.
Published: August 2002

The enzyme Ca2+/calmodulin‐dependent protein kinase II (CaMKII) is widely distributed in the nervous system. A previous report describes immunostaining for CaMKIIα in dorsal root ganglion (DRG) neurons. In this study, CaMKIIα is colocalized in the rat with three putative markers of nociceptive DRG neurons, isolectin Griffonia simplicifolia (I‐B4), identifying small‐diameter, “peptide‐poor” neurons; calcitonin gene‐related peptide (CGRP), identifying “ peptide‐rich” neurons; or the vanilloid receptor 1 (VR1), identifying neurons activated by heat, acid, and capsaicin. Lumbar 4 and 5 DRG sections were labeled using immunofluorescence or lectin binding histochemistry, and percentages of single and double‐labeled CaMKIIα neurons were determined. Stereological estimates of total neuron number in the L4 DRG were 13,815 ± 2,798 and in the L5 DRG were 14,111 ± 4,043. Percentages of single‐labeled L4 DRG neurons were 41% ± 2% CaMKIIα, 38% ± 3% I‐B4, 44% ± 3% CGRP, and 32% ± 6% VR1. Percentages of single‐labeled L5 DRG neurons were 44% ± 5% CaMKIIα, 48% ± 2% I‐B4, 41% ± 7% CGRP, and 39% ± 14% VR1. For L4 and L5, respectively, estimates of double‐labeled CaMKIIα neurons showed 34% ± 2% and 38% ± 17% labeled for I‐B4, 25% ± 14% and 19% ± 10% labeled for CGRP, and 37% ± 7% and 38% ± 5% labeled for VR1. Conversely, for L4 and L5, respectively, 39% ± 14% and 38% ± 7% I‐B4 binding neurons, 24% ± 12% and 23% ± 10% CGRP neurons, and 42% ± 7% and 35% ± 7% VR1 neurons labeled for CaMKIIα. The mean diameter of CaMKIIα‐ labeled neurons was approximately 27 μm, confirming that this enzyme was preferentially localized in small DRG neurons. The results indicate that subpopulations of DRG neurons containing CaMKIIα are likely to be involved in the processing of nociceptive information. Thus, this enzyme may play a critical role in the modulation of nociceptor activity and plasticity of primary sensory neurons. J. Comp. Neurol. 448:102–110, 2002. © 2002 Wiley‐Liss, Inc.
Neurochemistry of nerve fibers apposing sympathetic preganglionic neurons activated by sustained hypotension
Authors: Minson Jane B. , Arnolda Leonard F. , Llewellyn‐Smith Ida J.
Published: August 2002

Sympathetic preganglionic neurons (SPN) in rat spinal cord were activated by the reflex stimulation of bulbospinal sympathetic neuronal pathways after a nitroprusside‐induced hypotension. Hypotension‐sensitive SPN, identified by immunoreactivity (IR) to the product of the immediate early gene c‐fos and to choline acetyltransferase, were localized in the intermediolateral cell column of thoracic and upper lumbar cord, particularly middle to lower thoracic cord. Putative neurotransmitters, or their markers, in varicose fiber networks around SPN were identified. Nearly all hypotension‐sensitive (Fos‐IR) SPN were apposed by varicose fibers immunoreactive for tyrosine hydroxylase, serotonin, substance P, or enkephalin. Neuropeptide Y (NPY)‐ or phenylethanolamine‐N‐methyl transferase (PNMT)‐IR varicose fibers apposed Fos‐IR SPN in the upper and middle thoracic spinal cord, but in lower thoracic segments some Fos‐IR SPN lacked these appositions. In thoracic segment 12, 51% ± 5% of Fos‐IR SPN (n = 9 rats) lacked PNMT contacts and 25% ± 3% of Fos‐IR SPN (n = 8 rats) lacked NPY contacts. In contrast to other chemically defined afferents, galanin‐IR varicose fibers apposed fewer than half of the Fos‐IR SPN in the middle to lower thoracic cord. Neurotransmitters/neuromodulators that might influence the activity of SPN acting in the baroreflex‐mediated control of blood pressure have been identified. Uniformity in the neurochemistry of some fibers making connections with Fos‐IR SPN, regardless of their segmental origin, suggests that common sets of neurons provide convergent inputs to all hypotension‐sensitive SPN. Other fibers show topographic differences in their contacts with Fos‐IR SPN, suggesting that subgroups of hypotension‐sensitive SPN are targeted by particular neuron groups. J. Comp. Neurol. 449:307–318, 2002. © 2002 Wiley‐Liss, Inc.
Jaw‐muscle spindle afferent pathways to the trigeminal motor nucleus in the rat
Authors: Luo Pifu , Moritani Masayuki , Dessem Dean
Published: August 2002

Neural pathways conveying proprioceptive feedback from the jaw muscles were studied in rats by combining retrograde and intracellular neuronal labeling. Initially, horseradish peroxidase was iontophoresed unilaterally into the trigeminal motor nucleus (Vmo). Two days later, 1–5 jaw‐muscle spindle afferent axons located in the mesencephalic trigeminal nucleus were physiologically identified and intracellularly stained with biotinamide. Stained mesencephalic trigeminal jaw‐muscle spindle afferent axon collaterals and boutons were predominantly distributed in the supratrigeminal region (Vsup), Vmo, dorsomedial trigeminal principal sensory nucleus (Vpdm), parvicellular reticular formation (PCRt), alpha division of the parvicellular reticular formation (PCRtA), and dorsomedial portions of the spinal trigeminal subnuclei oralis (Vodm), and interpolaris (Vidm). Numerous neurons retrogradely labeled with horseradish peroxidase from the trigeminal motor nucleus were found bilaterally in the PCRt, PCRtA, Vodm, and Vidm. Retrogradely labeled neurons were also present contralaterally in the Vsup, Vpdm, Vmo, peritrigeminal zone, and bilaterally in the dorsal medullary reticular field. Putative contacts between intracellularly stained mesencephalic trigeminal jaw‐muscle spindle afferent boutons and trigeminal premotor neurons retrogradely labeled with horseradish peroxidase were found in the ipsilateral Vodm, PCRtA, and PCRt, as well as the contralateral Vsup, Vmo, Vodm, PCRt, and PCRtA. Thus, multiple disynaptic jaw‐muscle spindle afferent‐motoneuron circuits exist. These pathways are likely to convey long‐latency jaw‐muscle stretch reflexes and may contribute to stiffness regulation of the masticatory muscles. J. Comp. Neurol. 435:341–353, 2001. © 2001 Wiley‐Liss, Inc.
The number of morphological synapses between neurons does not predict the strength of their physiological synaptic interactions: A study of dendrites in the nematode Ascaris suum
Authors: Angstadt James D. , Donmoyer Judith E. , Stretton Antony O.W.
Published: August 2002

Previous electrophysiological and anatomical studies of Ascaris suum motor neurons demonstrated a strong correlation between functional interactions and the presence of anatomically defined synapses. However, one example of a physiologically robust synaptic connection was encountered for which no anatomical evidence of direct chemical synapses was found. This involved synaptic transmission from an identified excitatory motor neuron to its inhibitory partner. In this study, pressure injection of horseradish peroxidase or nickel lysine into inhibitory motor neurons revealed numerous spines projecting from the main neuronal process toward the neuromuscular surface that then branched and extended fine, longitudinal processes up to 130 μm in length. Subsequent examination of nickel lysine‐injected spines by electron microscopy revealed numerous chemical synapses, including for the first time direct inputs from the excitatory neuron. However, the numbers of synapses from this motor neuron were very small relative to inputs from other identified cells. Thus, direct synapses are unlikely to explain the robust nature of this physiological interaction. J. Comp. Neurol. 432:512–527, 2001. © 2001 Wiley‐Liss, Inc.
Changes in synaptic inputs to sympathetic preganglionic neurons after spinal cord injury
Authors: Llewellyn‐Smith Ida J. , Weaver Lynne C.
Published: August 2002

Spinal cord injury (SCI) leads to plastic changes in organization that impact significantly on central nervous control of arterial pressure. SCI causes hypotension and autonomic dysreflexia, an episodic hypertension induced by spinal reflexes. Sympathetic preganglionic neurons (SPNs) respond to SCI by retracting and then regrowing their dendrites within 2 weeks of injury. We examined changes in synaptic input to SPNs during this time by comparing the density and amino acid content of synaptic input to choline acetyltransferase (ChAT)‐immunoreactive SPNs in the eighth thoracic spinal cord segment (T8) in unoperated rats and in rats at 3 days or at 14 days after spinal cord transection at T4. Postembedding immunogold labeling demonstrated immunoreactivity for glutamate or γ‐aminobutyric acid (GABA) within presynaptic profiles. We counted the number of presynaptic inputs to measured lengths of SPN somatic and dendritic membrane and identified the amino acid in each input. We also assessed gross changes in the morphology of SPNs using retrograde labeling with cholera toxin B and light microscopy to determine the structural changes that were present at the time of evaluation of synaptic density and amino acid content. At 3 days after SCI, we found that retrogradely labeled SPNs had shrunken somata and greatly shortened dendrites. Synaptic density (inputs per 10‐μm membrane) decreased on ChAT‐immunoreactive somata by 34% but increased on dendrites by 66%. Almost half of the inputs to SPNs lacked amino acids. By 14 days, the density of synaptic inputs to dendrites and somata decreased by 50% and 70%, respectively, concurrent with dendrite regrowth. The proportion of glutamatergic inputs to SPNs in spinal cord‐transected rats (≈40%) was less than that in unoperated rats, whereas the GABAergic proportion (60–68%) increased. In summary, SPNs participate in vasomotor control after SCI despite profound denervation. An altered balance of excitatory and inhibitory inputs may explain injury‐induced hypotension. J. Comp. Neurol. 435:226–240, 2001. © 2001 Wiley‐Liss, Inc.
Distribution of gonadal steroid receptor–containing neurons in the preoptic–periaqueductal gray–brainstem pathway: A potential circuit for the initiation of male sexual behavior
Authors: Murphy Anne Z. , Hoffman Gloria E.
Published: August 2002

The present study used anterograde and retrograde tract tracing techniques to examine the organization of the medial preoptic—periaqueductal gray—nucleus paragigantocellularis pathway in the male rat. The location of neurons containing estrogen (alpha subtype; ERα) and androgen receptors (AR) were also examined. We report here that injection of the anterograde tracer biotinylated dextran amine (BDA) into the medial preoptic (MPO) produced dense labeling within the periaqueductal gray (PAG); anterogradely labeled fibers terminated in close juxtaposition to neurons retrogradely labeled from the nucleus paragigantocellularis (nPGi). Dual immunostaining for Fluoro‐Gold (FG) and ERα or FG and AR showed that over one‐third of MPO efferents to the PAG contain receptors for either estrogen or androgen. In addition, approximately 50% of PAG neurons retrogradely labeled from the nPGi were immunoreactive for either ERα or AR. These results are the first to establish an MPO→PAG→nPGi circuit and further indicate that gonadal steroids can influence neuronal synaptic activity within these sites. We reported previously that nPGi reticulospinal neurons terminate preferentially within the motoneuronal pools of the lumbosacral spinal cord that innervate the pelvic viscera. Together, we propose that the MPO→PAG→nPGi circuit forms the final common pathway whereby MPO neural output results in the initiation and maintenance of male copulatory reflexes. J. Comp. Neurol. 438:191–212, 2001. © 2001 Wiley‐Liss, Inc.
Crossed and uncrossed projections to the cat sacrocaudal spinal cord: III. Axons expressing calcitonin gene‐related peptide immunoreactivity
Authors: Ritz Louis A. , Murray Constance R. , Foli Kim
Published: August 2002

We have investigated the projection patterns of peptidergic small‐diameter primary afferent fibers to the cat sacrocaudal spinal cord, a region associated with midline structures of the lower urogenital system and of the tail. Calcitonin gene‐related peptide (CGRP)‐immunoreactive (CGRP‐IR) primary afferent fibers were observed within the superficial laminae, rostrally as the typical inverted U‐shaped band that capped the separate dorsal horns (S1 to rostral S2) and caudally as a broad band that spanned the entire mediolateral extent of the fused dorsal horns (caudal S2 and caudal). Within the dorsal gray commissure, labeling was seen as a periodic vertical, midline band. CGRP‐IR labeling was prevalent in an extensive mediolateral distribution at the base of the dorsal horn, originating from both lateral and medial collateral bundles that extend from the superficial dorsal horn. Some bundles, in part traveling within the dorsal commissure, conspicuously crossed the midline. In addition to the robust projection to the superficial dorsal horn, there was a more extensive distribution of CGRP‐IR fibers within the deeper portions of the cat sacrocaudal dorsal horn than has been reported for other regions of the cat spinal cord. Presumably, these deep projections convey visceral information to projection or segmental neurons at the neck of the dorsal horn and in the region of the central canal. This deep distribution overlaps the reported projections of the pelvic and pudendal nerves. In addition, the contralateral projections of CGRP‐IR fibers may form an anatomical substrate of the bilateral receptive fields for selective dorsal horn neurons. The density and variety of CGRP‐IR projection patterns is a reflection of the functional attributes of the innervated structures. J. Comp Neurol. 438:388–398, 2001. © 2001 Wiley‐Liss, Inc.
Diurnal variation of c‐Fos expression in subdivisions of the dorsal raphe nucleus of the Mongolian gerbil (Meriones unguiculatus)
Authors: Janušonis Skirmantas , Fite Katherine V.
Published: August 2002

Recent studies suggest that the dorsal raphe nucleus (DRN) of the brainstem contains several subdivisions that differ both anatomically and neurochemically. The present study examined whether variation of c‐Fos expression across the 24‐hour light‐dark cycle may also be different in these subdivisions. Animals were kept on a 12:12 light‐dark cycle, were perfused at seven different time points, and brain sections were processed by using c‐Fos immunocytochemistry. At all coronal levels of the DRN, c‐Fos expression reached a peak 1 hour after the light‐dark transition (lights‐off) and reached its lowest levels in the middle of the light period. In contrast to the light‐dark transition, c‐Fos levels did not change significantly after the dark‐light transition (lights‐on). One‐way analysis of variance (ANOVA) revealed that the diurnal variation of c‐Fos expression was highly significant in the caudal ventral DRN. Similar variation in c‐Fos expression also was observed in the other DRN subdivisions, but this variation appeared to gradually diminish in the caudal‐to‐rostral and ventromedial‐to‐dorsomedial directions. Double‐label immunocytochemistry revealed that, 1 hour after lights‐off, only 11% of c‐Fos‐positive neurons in the caudal ventral DRN were serotonin (5‐HT)‐immunoreactive. These results suggest that DRN subdivisions may differ functionally with regard to the diurnal cycle, and that these differences may be reflected in the activity of nonserotonergic cells in the DRN. J. Comp. Neurol. 440:31–42, 2001. © 2001 Wiley‐Liss, Inc.
Finite element approximation on quadrilateral meshes
Authors: Arnold Douglas N. , Boffi Daniele , Falk Richard S. , Gastaldi Lucia
Published: August 2002

Quadrilateral finite elements are generally constructed by starting from a given finite dimensional space of polynomials V̂ on the unit reference square K̂. The elements of V̂ are then transformed by using the bilinear isomorphisms FK which map K̂ to each convex quadrilateral element K. It has been recently proven that a necessary and sufficient condition for approximation of order r+1 in L2 and r in H1 is that V̂ contains the space Qr of all polynomial functions of degree r separately in each variable. In this paper several numerical experiments are presented which confirm the theory. The tests are taken from various examples of applications: the Laplace operator, the Stokes problem and an eigenvalue problem arising in fluid‐structure interaction modelling. Copyright © 2001 John Wiley & Sons, Ltd.
Ergodicity for the Navier‐Stokes equation with degenerate random forcing: Finite‐dimensional approximation
Authors: E Weinan , Mattingly Jonathan C.
Published: August 2002

We study Galerkin truncations of the two‐dimensional Navier‐Stokes equation under degenerate, large‐scale, stochastic forcing. We identify the minimal set of modes that has to be forced in order for the system to be ergodic. Our results rely heavily on the structure of the nonlinearity. © 2001 John Wiley & Sons, Inc.