bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the effects of animal age, concurrent bacterial infection, and pathogenicity of porcine reproductive and respiratory syndrome virus on virus concentration in pigs
Authors: Cho Jenny G. , Dee Scott A. , Deen John , Guedes Alonso , Trincado Carlos , Fano Eduardo , Jiang Yin , Faaberg Kay , Collins James E. , Murtaugh Michael P. , Joo Han Soo
Published: February 2006

Objective—To evaluate the influences of animal age, bacterial coinfection, and porcine reproductive and respiratory syndrome virus (PRRSV) isolate pathogenicity on virus concentration in pigs.

Animals—Twenty-one 2-month-old pigs and eighteen 6-month-old pigs.

Procedure—Pigs were grouped according to age and infected with mildly virulent or virulent isolates of PRRSV. The role of concurrent bacterial infection was assessed by infecting selected pigs with Mycoplasma hyopneumoniae 21 days prior to inoculation with PRRSV. On alternating days, blood and swab specimens of nasal secretions and oropharyngeal secretions were collected. On day 21 after inoculation with PRRSV, selected tissues were harvested. Concentrations of PRRSV were determined by use of quantitative real-time PCR and expressed in units of TCID50 per milliliter (sera and swab specimens) or TCID50 per gram (tissue specimens).

Results—Concentrations of virus were higher in blood and tonsils of pigs infected with virulent PRRSV. Pigs infected with virulent PRRSV and M hyopneumoniae had significantly higher concentrations of viral RNA in lymphoid and tonsillar tissue. Coinfection with M hyopneumoniae resulted in a higher viral load in oropharyngeal swab specimens and blood samples, independent of virulence of the PRRSV isolate. Two-month-old pigs had significantly higher viral loads in lymph nodes, lungs, and tracheal swab specimens than did 6-month-old pigs, independent of virulence of the PRRSV isolate.

Conclusions and Clinical Relevance—Multiple factors affect PRRSV concentration in pigs, including pathogenicity of the PRRSV isolate, age, and concurrent infection with M hyopneumoniae.
Association between incubation time and genotype in sheep experimentally inoculated with scrapie-positive brain homogenate
Authors: Bulgin Marie S. , Sorensen Sharon J. , Matlock Mary E.
Published: February 2006

Objective—To compare incubation time and clinical signs of scrapie in codon 136/171 alanine-valine/gluta-mine-glutamine (AVQQ) experimentally inoculated sheep with that in sheep with the more common 136/171 AAQQ genotype.

Animals—60 Suffolk sheep.

Procedure—Twenty-seven 171 QQ ewes purchased from 2 private flocks were bred with a 171 QQ Suffolk ram before being inoculated with a 20% solution of scrapie-positive brain homogenate (5 mL, PO) from sheep containing genotypes 136/154/171 AA/argi-nine-arginine (RR)/QQ, AVRRQQ, and VVRRQQ that had died of scrapie. Ewes had 33 lambs, which were inoculated in the same manner on the day of birth.

Results—All 16 genotype 136/154/171 AVRRQQ sheep that died of scrapie were 9 to 11 months of age; clinical signs lasted 1 day to 3 weeks with no wasting and only mild pruritus. The first AARRQQ sheep died with typical clinical signs of scrapie 27 months after inoculation, and 14 were still alive 37 to 42 months after inoculation. The 136/171 AVQQ sheep had minimal accumulation of modified cellular protein (PrPSC) as determined by immunohistochemical (IHC) staining within affected cells; thus the severity of clinical signs and time of death were not associated with brain lesions or the amount of PrPSC in brain tissue of 136/154/171 AVRRQQ sheep as determined by IHC staining.

Conclusions and Clinical Relevance—The rapid incubation time may have been influenced by the codon 136 genotype, a new unreported valine (V)-dependent strain of scrapie similar to strain SSBP/1, or the inoculum may have contained a traditional strain and a V-dependent or SSBP/1-like strain of scrapie.
Phase I trial and pharmacokinetic analysis of ifosfamide in cats with sarcomas
Authors: Rassnick Kenneth M. , Moore Antony S. , Northrup Nicole C. , Kristal Orna , Beaulieu Bernard B. , Lewis Lionel D. , Page Rodney L.
Published: February 2006

Objective—To determine the maximally tolerated dose (MTD) and dose-limiting toxicosis (DLT) of ifosfamide in tumor-bearing cats.

Animals—38 cats with resected, recurrent, or metastatic sarcomas.

Procedure—The starting dosage of ifosfamide was 400 mg/m2 of body surface area, IV, and dosages were increased by 50 to 100 mg/m2 in cohorts of 3 cats. To protect against urotoxicosis, mesna was administered at a dosage equal to 20% of the calculated ifosfamide dosage. Diuresis with saline (0.9% NaCl) solution before and after administration of ifosfamide was used to minimize nephrotoxicosis. Samples for pharmacokinetic analysis were obtained after the MTD was reached.

Results—38 cats were entered into this phase I study and were administered a single dose of ifosfamide at various dosages. The MTD was 1,000 mg/m2, and neutropenia was the DLT. Seven of 8 episodes of neutropenia were on day 7 after treatment, and 1 cat developed severe neutropenia on day 5. Adverse effects on the gastrointestinal tract were generally mild and self-limiting, the most common of which was nausea during ifosfamide infusion. One cat had signs consistent with a drug-induced hypersensitivity reaction. There were no episodes of hemorrhagic cystitis or nephrotoxicosis. Correlations between pharmacokinetic variables and ifosfamide-associated toxicoses were not found. Preliminary evidence of antitumor activity was observed in 6 of 27 cats with measurable tumors.

Conclusions and Clinical Relevance—The dosage of ifosfamide recommended to treat tumor-bearing cats is 900 mg/m2 every 3 weeks. This dosage should be used in phase II clinical trials.
Effect of administration of a controlled-release monensin capsule on incidence of calving-related disorders, fertility, and milk yield in dairy cows
Authors: Melendez Pedro , Goff Jesse P. , Risco Carlos A. , Archbald Louis F. , Littell Ramon C. , Donovan G. Arthur
Published: February 2006

Objective—To determine the effect of a controlled-release monensin capsule administered at cessation of lactation on incidence of calving-related disorders, fertility, and milk yield in dairy cows.

Animals—290 dairy cows treated with monensin and 290 untreated control cows.

Procedure—Treated cows received a capsule that released monensin at 335 mg/d for 95 days. Incidence of calving-related disorders; daily milk yield up to 20 days postpartum; test-day milk yield, fat, protein, and mature-equivalent 305-day milk production; and body condition score at calving were determined. Reproductive variables were conception rate at first service, pregnancy rate, and calving-to-conception interval.

Results—Cows treated with monensin were 2.1 times as likely to develop dystocia and 0.8 times as likely to develop metritis as control cows. For milk yield, there was an interaction of treatment ×time ×parity. In multiparous cows, monensin significantly improved milk yield at test days 4 and 7. In addition, monensin increased body condition score at calving.

Conclusions and Clinical Relevance—Despite increasing the likelihood of developing dystocia and metritis, administration of monensin improved the lactational performance of multiparous cows and may be a promising additive for use at the time of cessation of lactation.
Veterinarian-client-patient communication patterns used during clinical appointments in companion animal practice
Authors: Shaw Jane R. , Bonnett Brenda N. , Adams Cindy L. , Roter Debra L.
Published: February 2006

Objective—To identify communication patterns used by veterinarians during clinical appointments in companion animal practice.

Design—Cross-sectional descriptive study.

Sample Population—A random sample of 50 companion animal practitioners in southern Ontario and a convenience sample of 300 clients and their pets.

Procedure—For each practitioner, 6 clinical appointments (3 wellness appointments and 3 appointments related to a health problem) were videotaped. The Roter interaction analysis system was used to analyze the resulting 300 videotapes, and cluster analysis was used to identify veterinarian communication patterns.

Results—175 (58%) appointments were classified as having a biomedical communication pattern, and 125 (42%) were classified as having a biolifestyle-social communication pattern. None were classified as having a consumerist communication pattern. Twentythree (46%) veterinarians were classified as using a predominantly biomedical communication pattern, 19 (38%) were classified as using a mixed communication pattern, and 8 (16%) were classified as using a predominantly biolifestyle-social communication pattern. Pattern use was related to the type of appointment. Overall, 103 (69%) wellness appointments were classified as biolifestyle-social and 127 (85%) problem appointments were classified as biomedical. Appointments with a biomedical communication pattern (mean, 11.98 minutes) were significantly longer than appointments with a biolifestyle-social communication pattern (10.43 minutes). Median relationship-centered care score (ie, the ratio of client-centered talk to veterinarian-centered talk) was significantly higher during appointments with a biolifestyle-social communication pattern (1.10) than during appointments with a biomedical communication pattern (0.40).

Conclusions and Clinical Relevance—Results suggest that veterinarians in companion animal practice use 2 distinct patterns of communication. Communication pattern was associated with duration of visit, type of appointment, and relationship-centeredness. Recognition of these communication patterns has implications for veterinary training and client and patient outcomes.
Use of computed tomography for evaluation of lung lesions associated with spontaneous pneumothorax in dogs: 12 cases (1999–2002)
Authors: Au Jennifer J. , Weisman Debra L. , Stefanacci Joseph D. , Palmisano Matthew P.
Published: February 2006

Objective—To evaluate use of computed tomography (CT) of the lungs, compared with conventional radiography, for detection of blebs and bullae associated with spontaneous pneumothorax in dogs.

Design—Retrospective case series.

Animals—12 dogs with spontaneous pneumothorax.

Procedure—Medical records were reviewed, and information was collected that included signalment, body weight, initial owner complaint, laboratory findings, radiographic findings, CT findings, medical and surgical treatment, histologic findings, complications, duration of hospitalization, and final outcome.

Results—Radiographs were excellent for identifying pneumothorax (sensitivity, 100%) but poor for identifying the underlying cause (bullae or blebs); these were identified in radiographs of only 2 of 12 dogs. Computed tomography allowed identification of bullae or blebs in 9 of 12 dogs. Ten of the 12 dogs were treated via surgery, and 17 affected lung lobes were identified. Four of the 17 affected lobes were identified via radiography. Thirteen of the 17 affected lobes were identified via CT; however, 1 lobe was incorrectly identified as the right caudal lobe instead of the right cranial lobe.

Conclusions and Clinical Relevance—Results suggested that CT is better than radiography for identifying the underlying causes of spontaneous pneumothorax.
Renal transplantation in cats with calcium oxalate urolithiasis: 19 cases (1997–2004)
Authors: Aronson Lillian R. , Kyles Andrew E. , Preston Alicia , Drobatz Kenneth J. , Gregory Clare R.
Published: February 2006

Objective—To determine outcome of renal transplantation in cats with renal failure associated with calcium oxalate urolithiasis.

Design—Retrospective case series.

Animals—19 cats.

Procedure—Medical records were reviewed for evaluation of signalment, preoperative clinical signs, physical examination results, dietary history, clinicopathologic data, abdominal imaging, postoperative diet, complications, and long-term outcome.

Results—The domestic shorthair was the most common breed represented. There were 13 spayed females and 7 castrated males. Mean age was 6.8 years. Clinical signs included weight loss, lethargy, vomiting, anorexia, polyuria, and polydipsia. Before surgery, cats received commercially available canned or dry food (n = 10), a prescription renal failure diet (5), a commercial diet to manage struvite crystalluria (1), or an unknown diet (3). Seventeen cats were anemic. All cats were azotemic. Hypercalcemia was detected in 7 cats. Abdominal imaging revealed nephrolithiasis, ureterolithiasis, or both in all cats. Median duration of survival of all cats was 605 days. Eight cats were alive 282 to 2,005 days (median, 1,305 days) after surgery. Eleven cats died 2 to 1,197 days (median, 300 days) after surgery. Five cats formed calculi in their allograft (120 to 665 days). Two of the 5 cats that formed calculi were hypercalcemic. Four of the 5 cats died following complications associated with formation of calculi.

Conclusions and Clinical Relevance—Renal transplantation appears to be a viable option for cats in renal failure secondary to calcium oxalate urolithiasis. In addition to reported complications in renal transplant recipients, formation of calculi within the allograft may also occur.
Molecular characterization of Clostridium difficile isolates from horses in an intensive care unit and association of disease severity with strain type
Authors: Magdesian K. Gary , Dujowich Mauricio , Madigan John E. , Hansen Lori M. , Hirsh Dwight C. , Jang Spencer S.
Published: February 2006

Objective—To determine molecular characteristics, antimicrobial susceptibility, and toxigenicity of Clostridium difficile isolates from horses in an intensive care unit and evaluate associations among severity of clinical disease with specific strains of C difficile.

Design—Prospective study.

Animals—130 horses.

Procedures—Feces were collected from horses admitted for acute gastrointestinal tract disease with loose feces and submitted for microbial culture and immunoassay for toxin production. Polymerase chain reaction assays were performed on isolates for toxins A and B genes and strain identification.

Results—Isolates were grouped into 3 strains (A, B, and C) on the basis of molecular banding patterns. Toxins A and B gene sequences were detected in 93%, 95%, and 73% of isolates of strains A, B, and C, respectively. Results of fecal immunoassays for toxin A were positive in 40%, 63%, and 16% of horses with strains A, B, and C, respectively. Isolates in strain B were resistant to metronidazole. Horses infected with strain B were 10 times as likely to have been treated with metronidazole prior to the onset of diarrhea as horses infected with other strains. Duration from onset of diarrhea to discharge (among survivors) was longer, systemic inflammatory response syndromes were more pronounced, and mortality rate was higher in horses infected with strain B than those infected with strains A and C combined.

Conclusions and Clinical Relevance—Horses may be infected with a number of heterogeneous isolates of C difficile. Results indicated that toxigenicity and antimicrobial susceptibility of isolates vary and that metronidazole-resistant strains may be associated with severe disease.
Pulmonary hypertension and right-sided heart failure in an adult llama with hepatic disease
Authors: Middleton John R. , Chigerwe Munashe , Fine Deborah M. , Turk James R. , Lattimer Jimmy C.
Published: February 2006

Case Description—A 13-year-old llama was examined because of lethargy, inappetence, and syncope.

Clinical Findings—Physical examination revealed muffled heart and lung sounds and peripheral edema. Clinicopathologic abnormalities included lymphopenia, hyperglycemia, prerenal azotemia, mild hyponatremia, mild hypoalbuminemia, and high γ-glutamyltransferase and creatine kinase activities. On ultrasonography, the liver appeared hyperechoic and ascites and pleural effusion were seen. Echocardiography revealed severe dilatation of the right atrium, right ventricle, and pulmonary artery; severe tricuspid regurgitation; and high right ventricular systolic pressure consistent with right-sided heart failure secondary to pulmonary hypertension.

Treatment and Outcome—Treatment with furosemide was attempted, but because of failing health, the llama was euthanized 4 weeks later. Macronodular cirrhosis of the liver, glomerulonephritis, and intimal fibrosis and medial hypertrophy of muscular pulmonary arteries were seen on histologic examination of postmortem specimens.

Clinical Relevance—Findings in this case were similar to those reported for human patients with portopulmonary hypertension secondary to hepatic cirrhosis. Pulmonary hypertension secondary to hepatic disease should be considered in the differential diagnosis of right-sided heart failure.
Cover Picture: A Micropatterned Hydrogel Platform for Chemical Synthesis and Biological Analysis (Adv. Mater. 5/2006)
Authors: Zourob M. , Gough J. E. , Ulijn R. V.
Published: March 2006

A polymer hydrogel platform for peptide arrays compatible with both solid‐phase peptide synthesis conditions and the aqueous environment essential for biological assays is reported on p. 655 by Ulijn and co‐workers. Micropatterning followed by multiple‐step peptide synthesis produces the peptide‐functionalized poly(ethylene glycol)–polyamide “biochips” shown schematically on the cover. On‐chip biological assays involving cells and enzymes provide proof‐of‐concept.
Palladium/Magnesium‐Lanthanum Mixed Oxide Catalyst in the Heck Reaction
Authors: Cwik Agnieszka , Hell Zoltán , Figueras François
Published: March 2006

A new, reusable palladium/magnesium‐lanthanum mixed oxide catalyst has been found to exhibit unprecedented high catalytic activity and selectivity for the heterogeneous Heck cross‐coupling reaction of aryl halides with alkenes. The nature of the aryl halides has a determinate effect on the reaction yield. The corresponding reactions of a wide range of activated and non‐activated aryl bromides and chlorides furnished the arylated product with high E/Z isomer ratios even already at 80 °C. The stereoselectivity depended on the nature of the olefins.
Metal‐Free Chemoselective Oxidation of Sulfides to Sulfoxides by Hydrogen Peroxide Catalyzed by in situ Generated Dodecyl Hydrogen Sulfate in the Absence of Organic Co‐Solvents
Authors: Firouzabadi H. , Iranpoor N. , Jafari A. A. , Riazymontazer E.
Published: March 2006

The mild oxidation of sulfides to sulfoxides with an aqueous solution of H2O2 (35%) catalyzed by in situ generated dodecyl hydrogen sulfate as Brønsted acid surfactant in the absence of any organic co‐solvents and under metal‐free conditions is described. The method shows high chemoselectivity and the process is highly green for solid sulfoxides which crystallize out immediately after their formation from the reaction mixture. Liquid sulfoxides can be isolated under high vacuum by bulb‐to‐bulb distillation or by extraction with Et2O or EtOAc. Yields of the products are excellent.
Air‐Stable, Phosphine‐Free Anionic Palladacyclopentadienyl Catalysts: Remarkable Halide and Pseudohalide Effects in Stille Coupling
Authors: Crawforth Catherine M. , Fairlamb Ian J. S. , Kapdi Anant R. , Serrano José Luis , Taylor Richard J. K. , Sanchez Gregorio
Published: March 2006

The Stille cross‐coupling of allylic and benzyl bromides is shown to proceed efficiently using phosphine‐free dinuclear anionic palladacyclopentadienyl catalysts possessing bridging (N,O)‐imidate ligands. The type of bridging anion influences the catalytic activity considerably. Halide anions such as chloride, bromide or iodide also influence the catalytic activity but to a far lesser extent than the pseudohalide imidate anions (from succinimide or phthalimide). A Baldwin‐type cooperative effect is seen with 7a using CuI as a co‐catalyst, in the presence of two equivalents of CsF in DMF at 40 °C. In toluene, these additives slow down substrate turnover.
Application of Tridentate Bis(oxazoline) Ligands in Catalytic Asymmetric Nozaki–Hiyama Allylation and Crotylation: An Example of High Enantioselection with a Non‐Symmetric Bis(oxazoline) Ligand
Authors: McManus Helen A. , Cozzi Pier Giorgio , Guiry Patrick J.
Published: March 2006

A series of both symmetric and non‐symmetric bis(oxazoline) ligands was applied in the Nozaki–Hiyama allylation and crotylation of benzaldehyde. It was found that both the magnitude and sense of the asymmetric induction depended strongly on the nature and combination of the oxazoline substituents. For both reactions, the non‐symmetric tert‐butyl/benzyl‐substituted ligand proved to be the optimal ligand and was applied successfully in the allylation and crotylation of a range of aryl and aliphatic aldehydes. The enantioselectivities obtained in allylation were up to 91% ee and in crotylation up to 92% with typical syn:anti ratios of up to 80 : 20.
Dynamic Kinetic Resolution over Cinchona‐Modified Platinum Catalyst: Hydrogenation of Racemic Ethyl 2‐Fluoroacetoacetate
Authors: Szőri Kornél , Szöllősi György , Bartók Mihály
Published: March 2006

The enantioselective hydrogenation over a Cinchona alkaloid‐modified supported platinum catalyst and parallel spontaneous racemization under the reaction conditions of the unreacted enantiomer of ethyl 2‐fluoroacetoacetate are described. Using the appropriate reaction conditions an 82% enantiomeric excess in favor of the (2S,3R)‐ethyl 2‐fluoro‐3‐hydroxybutanoate and a 99/1 threo/erythro ratio were obtained. This novel method for producing optically enriched α‐fluoro‐β‐hydroxy esters is the first example of dynamic kinetic resolution of a chirally labile racemic fluorinated compound over a modified heterogeneous metal catalyst carried out without using supplementary additives except the chiral modifier. The hydrogenation described here shows that the activation of the keto group of acetoacetates by one fluorine atom in the α position is also sufficient for obtaining high enantiomeric excess in the Orito reaction.
Small Peptide‐Catalyzed Enantioselective Addition of Ketones to Nitroolefins
Authors: Xu Yongmei , Zou Weibiao , Sundén Henrik , Ibrahem Ismail , Córdova Armando
Published: March 2006

The direct small peptide‐catalyzed enantioselective Michael addition of ketones to nitroolefins is presented. Simple di‐ and tripeptides derived from alanine catalyze the asymmetric Michael additions with high stereoselectivity and furnish the corresponding Michael products in high yield with up to 68 : 1 dr and 98% ee. The study demonstrates that small, readily prepared peptides with increased structural complexity as compared to the parent amino acid mediate the asymmetric Michael reaction with superior reactivity and enantioselectivity.
The High Yield Synthesis of Benzaldehydes from Benzylic Alcohols using Homogeneously Catalyzed Aerobic Oxidation in Acetic Acid
Authors: Partenheimer Walt
Published: March 2006

The kinetics and yields for the formation of benzaldehydes from benzylic alcohols via aerobic oxidation using homogeneous catalysts in acetic acid are reported. For compounds of the type X‐C6H4CH2OH where X=H, 4‐CH3, 4‐OCH3, 4‐Cl, 4‐COOH the observed yields were 84, 78, 57, 88 and 52 mol %, respectively. These yields are comparable to those reported for the stoichiometric Co(III)/Br oxidation of these same benzylic alcohols. These results are limited to benzylic alcohols. The high yields are possible for two reasons: 1) the rate of reaction exhibits two maxima in which the benzaldehyde is predominately being generated in the first phase and the carboxylic acid in the second and 2) the competing esterification of the benzylic alcohol with the acetic acid solvent is an order of magnitude slower. A variety of other catalysts were also evaluated which give lower yields mainly because they are less active and the competing esterification reaction becomes more important. Water addition to the acetic acid increased the rate of acetylation of the alcohol, contrary to expectation. The oxidation of the benzaldehyde appears to be inhibited by the presence of the benzylic alcohol. Even though the rate of oxidation of the benzaldehyde, by itself, is equally reactive as the benzylic alcohol, the benzaldehyde does not significantly react until the benzylic alcohol concentration is very low. Two possible reasons, using a free‐radical chain mechanism, are suggested to explain this behavior. A mechanism demonstrating why the stoichiometric and catalytic reactions give similar yields is given.
A One‐Pot Enantioselective Chemo‐Enzymatic Synthesis of Amino Acids in Water
Authors: Simons Chrétien , Hanefeld Ulf , Arends Isabel W. C. E. , Maschmeyer Thomas , Sheldon Roger A.
Published: March 2006

The combination of immobilised Rh‐MonoPhos (1‐AlTUD‐1) and acylase I afforded a chemo‐enzymatic, one‐pot process for the enantioselective synthesis of amino acids in water, without the need for isolation of intermediates. In addition, the enzymatic hydrolysis increases the enantiopurity of the product from 95% ee to >98% ee. Compatibility studies revealed that for optimum results compartmentalisation of the catalysts is required.
Enantioselective Cyanosilylation of Ketones Catalyzed by a Nitrogen‐Containing Bifunctional Catalyst
Authors: Xiong Yan , Huang Xiao , Gou Shaohua , Huang Jinglun , Wen Yuehong , Feng Xiaoming
Published: March 2006

An efficient and optically active, bifunctional tetraaza ligand (2S)‐N‐{(1R,2R)‐2‐[(S)‐pyrrolidine‐2‐carboxamido]‐1,2‐diphenylethyl}pyrrolidine‐2‐carboxamide has been developed for the addition of trimethylsilyl cyanide (TMSCN) to ketones. The bifunctional catalyst system based on a monometallic titanium complex was found to be a highly enantioselective catalyst to provide O‐TMS cyanohydrins with up to 94% ee. A possible transition state has been proposed to explain the origin of the activation and asymmetric inductivity.
Catalytic Asymmetric Epoxidation of Unfunctionalised Olefins using Silica, LDH and Resin‐Supported Sulfonato‐Mn(salen) Complex
Authors: Choudary B. M. , Ramani Thekkathu , Maheswaran H. , Prashant Leon , Ranganath K. V. S. , Kumar K. Vijay
Published: March 2006

Sulfonated chiral Mn(salen) catalyst immobilised onto various supports such as silica, LDH and resin afforded remarkably higher rates and ees of up to 96% for the asymmetric epoxidation of unfunctionalised olefins. The LDH and resin supported (R,R)‐1 catalysts were recovered quantitatively by simple filtration and reused for several times with consistent ees and insignificant loss of activity.
Asymmetric Addition of Phenylacetylene to Aldehydes Catalyzed by β‐Sulfonamide Alcohol‐Titanium Complex
Authors: Xu Zhaoqing , Lin Li , Xu Jiangke , Yan Wenjin , Wang Rui
Published: March 2006

A series of β‐sulfonamide alcohol ligands were synthesized from L‐phenylalanine. Titanium complexes of these compounds were used to catalyze the asymmetric addition of phenylacetylene to a number of aldehydes. When the conditions were optimized, 20 mol % of ligand 8a catalyzed the reaction with high enantioselectivity (up to 98% ee) and good yield (up to 92%). When a small amount of MeOH was added to the reaction as a modifier, as little as 5 mol % of ligand was required to efficiently catalyze the reaction under very mild conditions, resulting in an ee of up to 99% and good yield.
Exploration of hydrogen production in a membrane reformer
Authors: Feng Wei , Tan Tianwei , Ji Peijun , Zheng Danxing
Published: March 2006

Auto‐thermal reforming (ATR) is one of the key technologies to produce hydrogen from natural gas. Applying an H2 membrane to an ATR reactor can simplify the process for pure hydrogen production, and in the meantime can promote methane conversion into hydrogen. Although it is a promising approach and has a great potential application in the future, it is still in an early stage of development. The objective of this work is to systematically study the factors affecting the pure hydrogen production and the thermodynamic efficiency of the integrated process containing an H2‐membrane ATR reactor. The study has been accomplished by the simulation of the H2‐membrane ATR reactor and the thermodynamic analysis of the process. The simulation work is based on the kinetics of the reactions and the mechanisms of membrane permeation. The effects of factors including the flowing mode of sweeping gas, the rate of sweeping gas, the inlet rate of CH4, and the inlet ratio of CH4 to H2O, on the production rate of separated H2, on the driving force of hydrogen permeation, and on the thermodynamic efficiency of the integrated process have been explored. The results will have a significant contribution to the design of an H2‐membrane ATR reactor and an integrated process for pure hydrogen production. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Synthesis, Physicochemical and Anticonvulsant Properties of New N‐(Pyridine‐2‐yl) Derivatives of 2‐Azaspiro[4.4]nonane and [4.5]decane‐1,3‐dione. Part II
Authors: Kaminski Krzysztof , Obniska Jolanta , Zagorska Agnieszka , Maciag Dorota
Published: March 2006

A series of N‐(pyridine‐2‐yl) derivatives of 2‐azaspiro[4.4]nonane‐ (1a–e), 2‐azaspiro[4.5]decane‐ (2a–e) and 6‐methyl‐2‐azaspiro[4.5]decane‐1,3‐dione (3a–e) were synthesized and tested for their anticonvulsant activity in the maximum electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) seizure threshold tests. To explain the possible mechanism of action, the most active compounds N‐(3‐methylpyridine‐2‐yl)‐2‐azaspiro[4.4]nonane‐1,3‐dione (1b), N‐(3‐methylpyridine‐2‐yl)‐2‐azaspiro[4.5]decane‐1,3‐dione (2b), N‐(4‐methylpyridine‐2‐yl)‐2‐azaspiro[4.5]decane‐1,3‐dione (2c), and N‐(3‐methylpyridine‐2‐yl)‐6‐methyl‐2‐azaspiro[4.5]decane‐1,3‐dione (3b) were tested in vitro for their influence on voltage‐sensitive calcium channel receptors, however, they revealed low affinities. For all synthesized compounds the lipophilicity was determined by use of RP‐TLC method. The correlation between the lipophilicity and anticonvulsant activity was obtained – the higher the lipophilicity the stronger the anticonvulsant efficacy.
A procedure for the computation of accurate PWL approximations of non‐linear dynamical systems
Authors: Repetto Lorenzo , Parodi Mauro , Storace Marco
Published: March 2006

In this paper we propose a variational method to find out piecewise‐linear (PWL) approximations of non‐linear dynamical systems in view of their circuit implementations. The method is based on some significant trajectories of the dynamical system and provides reasonably accurate PWL approximations with a relatively low number of parameters. The effectiveness of the method is validated by applying it to the approximation of limit cycles (both stable and unstable) in the Bautin system. Copyright © 2006 John Wiley & Sons, Ltd.
Effect of cell:cell competition and BAFF expression on peripheral B cell tolerance and B‐1 cell survival in transgenic mice expressing a low level of Igκ‐reactive macroself antigen
Authors: Aït‐Azzouzene Djemel , Gavin Amanda L. , Skog Patrick , Duong Bao , Nemazee David
Published: March 2006

In mice carrying a synthetic Igκ‐reactive superantigen (“κ macroself antigen”), low level expression induced split peripheral B cell tolerance in the sIgκ+compartment, with striking reductions in follicular and marginal zone (MZ) B cells and the retention of significant numbers of sIgκ+B‐1a but not B‐1b cells in the peritoneum. Here, we characterize the transgenic line pKκ with this split tolerance phenotype and assess the effects of B cell competition and the survival cytokine BAFF (B cell activating factor belonging to the TNF family) on peripheral tolerance. In pKκ mice the surviving peritoneal and splenic κ+B cells were largely lost in mice carrying one copy of the human Cκ exon in place of the mouse version, a maneuver that generates additional antigen non‐reactive competitor B cells in this model. Furthermore, overexpression of BAFF suppressed κ‐macroself antigen‐induced deletion and promoted production of both IgM,κ and IgA,κ antibodies in mice with normal Igκ alleles but not in mice carrying one copy of the human Cκ allele. These findings suggest that BAFF overexpression has minimal effects on the survival of autoreactive B cells in a polyclonal immune system and that B cell:B cell competition plays a potent role in suppressing the survival of B‐1 and splenic B cells with excessive autoreactivity.
Chemo‐enzymatic epoxidation of linoleic acid: Parameters influencing the reaction
Authors: Orellana‐Coca Cecilia , Camocho Samuel , Adlercreutz Dietlind , Mattiasson Bo , Hatti‐Kaul Rajni
Published: March 2006

No abstracts.
Bioactive minor compounds of extra‐virgin olive oil: the ibuprofen‐like activity of oleocanthal
Authors: Galli Claudio
Published: March 2006

No abstracts.
Prognosis of follicular lymphomas
Authors: Luminari Stefano , Federico Massimo
Published: March 2006

Follicular lymphoma (FL) is as an indolent neoplasia with median survival measured in decades. Nevertheless, some patients have poor progression‐free survival and overall survival. Several treatment approaches are proposed for patients with FL, however criteria to rationalize treatment decisions are lacking. Studies have been performed to build up prognostic indices that are useful for defining risk‐adapted treatment recommendations. Available indices are based on parameters that have an independent role in predicting patient survival and that are variably correlated with the features of the disease, with the characteristics of the patient and with the effects of treatment. Two new prognostic indices have recently been proposed for FL: the Italian Lymphoma Intergroup (ILI) index and the Follicular Lymphoma International prognostic Index (FLIPI). Both indices are based on large series of patients and exhibit differences in their ability to discriminate between patients with different probabilities of survival. In recent years, with the advent of gene expression profile studies, our knowledge of the biology of FL is changing as novel data become available about the lymphoma cell and about the role of the microenvironment; these studies have already provided novel prognostic tools for identifying patients with more aggressive disease. Further data and large international cooperative studies are needed to translate into clinical practice the novel acquisitions of biology and therapeutics. Copyright © 2006 John Wiley & Sons, Ltd.
In vivo biodegradability and biocompatibility evaluation of novel alanine ester based polyphosphazenes in a rat model
Authors: Sethuraman Swaminathan , Nair Lakshmi S. , El‐Amin Saadiq , Farrar Robert , Nguyen My‐Tien N. , Singh Anurima , Allcock Harry R. , Greish Yaser E. , Brown Paul W. , Laurencin Cato T.
Published: March 2006

Amino acid ester substituted polyphosphazenes are attractive candidates for various biomedical applications because of their biocompatibility, controllable hydrolytic degradation rates, and nontoxic degradation products. In this study, the biocompatibility of three L‐alanine ethyl ester functionalized polyphosphazenes was evaluated in a subcutaneous rat model. The polymers used in the study were poly[bis(ethylalanato)phosphazene] (PNEA), poly[(50% ethylalanato) (50% methylphenoxy) phosphazene] (PNEA50mPh50), and poly[(50% ethylalanato)(50% phenyl phenoxy) phosphazene] (PNEA50PhPh50). Polymer disks of diameter 7.5 mm were prepared by a solvent evaporation technique and were implanted subcutaneously in rats. After 2, 4, and 12 weeks, the polymer along with the surrounding tissues were excised, prepared, and viewed by light microscopy to evaluate the tissue responses of the implanted polymers. The tissue responses were classified as minimal, mild, or moderate, based on a biocompatibility scheme developed in our laboratory. Minimal inflammation was characterized by the presence of few neutrophils, erythrocytes, and lymphocytes; mild response was characterized by the predominant presence of macrophages, fibroblasts, or giant cells; and moderate inflammation was characterized by the abundance of macrophages, giant cells, and by the presence of tissue exudates. The in vivo degradation profiles of the polymers at various time points were evaluated by gel permeation chromatography (GPC). PNEA and PNEA50mPh50 matrices elicited varying levels of tissue responses during the 12‐week implantation period. At 2 weeks both polymers evoked a moderate response, and by 12 weeks the response was found to be mild. However, PNEA50PhPh50 elicited a mild response at the end of 2 weeks and demonstrated a further decreased inflammatory response after12 weeks. The in vivo degradation of the polymers was followed by determining the molecular weights of the explanted polymer disks. PNEA and PNEA50mPh50 disks showed significant decrease in molecular weight after 2 weeks of implantation. The molecular weights of PNEA and PNEA50mPh50 residues could not be determined by GPC after 12 weeks of implantation because of almost complete degradation. On the other hand the in vivo degradation of PNEA50PhPh50 was found to be slow, with a 63% loss in molecular weight in 12 weeks. Furthermore, this polymer maintained its shape and structure during the entire study. Thus, these polymers demonstrated excellent tissue compatibility and in vivo biodegradability and can be potential candidates for various biomedical applications. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Expansion on specific substrates regulates the phenotype and differentiation capacity of human articular chondrocytes
Authors: Barbero Andrea , Grogan Shawn Patrick , Mainil‐Varlet Pierre , Martin Ivan
Published: March 2006

In this study, we investigated if monolayer expansion of adult human articular chondrocytes (AHAC) on specific substrates regulates cell phenotype and post‐expansion multilineage differentiation ability. AHAC isolated from cartilage biopsies of five donors were expanded on plastic dishes (PL), on dishes coated with collagen type II (COL), or on slides coated with a ceramic material (Osteologic™, OS). The phenotype of expanded chondrocytes was assessed by flow cytometry and real‐time RT‐PCR. Cells were then cultured in previously established conditions promoting differentiation toward the chondrogenic or osteogenic lineage. AHAC differentiation was assessed histologically, biochemically, and by real‐time RT‐PCR. As compared to PL‐expanded AHAC, those expanded on COL did not exhibit major phenotypic changes, whereas OS‐expanded cells expressed (i) higher bone sialoprotein (BSP) (22.6‐fold) and lower collagen type II (9.3‐fold) mRNA levels, and (ii) lower CD26, CD90 and CD140 surface protein levels (1.4–11.1‐fold). Following chondrogenic differentiation, COL‐expanded AHAC expressed higher mRNA levels of collagen type II (2.3‐fold) and formed tissues with higher glycosaminoglycan (GAG) contents (1.7‐fold), whereas OS‐expanded cells expressed 16.5‐fold lower collagen type II and generated pellets with 2.0‐fold lower GAG contents. Following osteogenic differentiation, OS‐expanded cells expressed higher levels of BSP (3.9‐fold) and collagen type I (2.8‐fold) mRNA. In summary, AHAC expansion on COL or OS modulated the de‐differentiated cell phenotype and improved the cell differentiation capacity respectively toward the chondrogenic or osteogenic lineage. Phenotypic changes induced by AHAC expansion on specific substrates may mimic pathophysiological events occurring at different stages of osteoarthritis and may be relevant for the engineering of osteochondral tissues. J. Cell. Biochem. 98: 1140–1149, 2006. © 2006 Wiley‐Liss, Inc.
Identification of a PTH regulated gene selectively induced in vivo during PTH‐mediated bone formation
Authors: Robinson John A. , Susulic Vedrana , Liu Yao‐Bin , Taylor Chanda , Hardenburg Jill , Gironda Virginia , Zhao Weiguang , Kharode Yogendra , McLarney Sean , Bai Yuchen , Malone Daniel P. , Murrills Richard , Bex Fred
Published: March 2006

The biological activities of parathyroid hormone (PTH) on bone are quite complex as demonstrated by its catabolic and anabolic activities on the skeleton. Although there have been many reports describing genes that are regulated by PTH in osteoblast cells, the goal of this study was to utilize a well‐established in vivo PTH anabolic treatment regimen to identify genes that mediate bone anabolic effects of PTH. We identified a gene we named PTH anabolic induced gene in bone (PAIGB) that has been reported as brain and acute leukemia cytoplasmic (BAALC). Therefore, using the latter nomenclature, we have discovered that BAALC is a PTH‐regulated gene whose mRNA expression was selectively induced in rat tibiae nearly 100‐fold (maximal) by a PTH 1–34 anabolic treatment regimen in a time‐dependent manner. Although BAALC is broadly expressed, PTH did not regulate BAALC expression in other PTH receptor expressing tissues and we find that the regulation of BAALC protein by PTH in vivo is confined to mature osteoblasts. Further in vitro studies using rat UMR‐106 osteoblastic cells show that PTH 1–34 rapidly induces BAALC mRNA expression maximally by 4 h while the protein was induced by 8 h. In addition to being regulated by PTH 1–34, BAALC expression can also be induced by other bone forming factors including PGE2and 1,25 dihydroxy vitamin D3. We determined that BAALC is regulated by PTH predominantly through the cAMP/PKA pathway. Finally, we demonstrate in MC3T3‐E1 osteoblastic cells that BAALC overexpression regulates markers of osteoblast differentiation, including downregulating alkaline phosphatase and osteocalcin expression while inducing osteopontin expression. We also demonstrate that these transcriptional responses mediated by BAALC are similar to the responses elicited by PTH 1–34. These data, showing BAALC overexpression can mimic the effect of PTH on markers of osteoblast differentiation, along with the observations that BAALC is induced selectively with a bone anabolic treatment regimen of PTH (not a catabolic treatment regimen), suggest that BAALC may be an important mediator of the PTH anabolic action on bone cell function. J. Cell. Biochem. 98: 1203–1220, 2006. © 2006 Wiley‐Liss, Inc.
Mitochondrial mechanism of microvascular endothelial cells apoptosis in hyperhomocysteinemia
Authors: Tyagi Neetu , Ovechkin Alexander V. , Lominadze David , Moshal Karni S. , Tyagi Suresh C.
Published: March 2006

An elevated level of homocysteine (Hcy) limits the growth and induces apoptosis. However, the mechanism of Hcy‐induced programmed cell death in endothelial cells is largely unknown. We hypothesize that Hcy induces intracellular reactive oxygen species (ROS) production that leads to the loss of transmembrane mitochondrial potential (Δψm) accompanied by the release of cytochrome‐c from mitochondria. Cytochrome‐c release contributes to caspase activation, such as caspase‐9, caspase‐6, and caspase‐3, which results in the degradation of numerous nuclear proteins including poly (ADP‐ribose) polymerase (PARP), which subsequently leads to the internucleosomal cleavage of DNA, resulting cell death. In this study, rat heart microvascular endothelial cells (MVEC) were treated with different doses of Hcy at different time intervals. Apoptosis was measured by DNA laddering and transferase‐mediated dUTP nick‐end labeling (TUNEL) assay. ROS production and MP were determined using florescent probes (2,7‐dichlorofluorescein (DCFH‐DA) and 5,5′,6,6′‐tetrachloro‐1,1′,3,3′‐tetraethyl‐benzamidazolocarbocyanin iodide (JC‐1), respectively, by confocal microscopy. Differential gene expression for apoptosis was analyzed by cDNA array. The results showed that Hcy‐mediated ROS production preceded the loss of MP, the release of cytochrome‐c, and the activation of caspase‐9 and ‐3. Moreover the Hcy treatment resulted in a decrease in Bcl2/Bax ratio, evaluated by mRNA levels. Caspase‐9 and ‐3 were activated, causing cleavage of PARP, a hallmark of apoptosis and internucleosomal DNA fragmentation. The cytotoxic effect of Hcy was blocked by using small interfering RNA (siRNA)‐mediated suppression of caspase‐9 in MVEC. Suppressing the activation of caspase‐9 inhibited the activation of caspase ‐3 and enhanced the cell viability and MP. Our data suggested that Hcy‐mediated ROS production promotes endothelial cell death in part by disturbing MP, which results in subsequent release of cytochrome‐c and activation of caspase‐9 and 3, leading to cell death. J. Cell. Biochem. 98: 1150–1162, 2006. © 2006 Wiley‐Liss, Inc.
AUF1‐like protein binds specifically to DAS cis‐acting element that regulates mouse α‐fetoprotein gene expression
Authors: Jiao Ruiqing , He Qing‐Yu , Chen Hongmin , Hua Zichun , Jiao Qincai , Chiu Jen‐fu
Published: March 2006

Alpha‐fetoprotein (AFP) is one of the major serum proteins in the early life of mammals. We have previously identified a novel cis‐acting element designated as DAS at the 5′‐flanking region of the AFP gene and demonstrated that the DAS sequence can be specifically recognized by nuclear protein DAP‐II in AFP‐producing hepatoma cells and retinoic acid (RA)‐induced AFP‐producing F9 cells. In this study, we used DNA affinity chromatography to purify the DAP‐II proteins from the nuclear extracts (NE) of RA‐treated F9 cells. The purified DAP‐II complex mainly contained five proteins, with molecular weights of 45, 42, 32, 30, and 20 kDa, respectively. The identification of these proteins was determined by MALDI‐TOF mass spectrometric analysis and a database search. These proteins were found to belong to the AUF1 RNA‐binding protein family. Protein (30 kDa), one of five proteins in an isolated DAP‐II complex, was matched with amino acid sequence highly similar to muAUF1‐3. The expression of this protein is inducible by RA, and the pattern of the protein expression is the same as DAP‐II proteins in F9 cells after treatment with RA during differentiation. Our results suggest that the 30‐kDa protein is a novel isoform of AUF1 family and is the main component of the DAP‐II complex that binds to the DAS sequence. J. Cell. Biochem. 98: 1257–1270, 2006. © 2006 Wiley‐Liss, Inc.
Osteoblast‐conditioned media influence the expression of E‐selectin on bone‐derived vascular endothelial cells
Authors: Makuch Lauren A. , Sosnoski Donna M. , Gay Carol V.
Published: March 2006

Breast cancer cells frequently metastasize to the ends of long bones, ribs and vertebrae, structures which contain a rich microvasculature that is closely juxtaposed to metabolically active trabecular bone surfaces. This study focuses on the effects of osteoblast secretions on the surface presentation of adhesive proteins on skeletal vascular endothelial cells. Vascular endothelial cells were isolated from trabecular bone regions of the long bones of 7‐week‐old Swiss Webster mice and also from the central marrow cavity where trabecular bone is absent. Both types of endothelial cells were placed in culture for 7 days, then exposed 24 h to conditioned media from MC3T3‐E1 osteoblasts. Conditioned medium (CM) from two different stages of osteoblast development were tested: (1) from immature MC3T3‐E1 cells cultured for 5–7 days and (2) from mature MC3T3‐E1 cells cultured for 28–30 days. The immature osteoblasts were in a stage of rapid proliferation; the mature osteoblasts formed a matrix that mineralized. Following exposure to the conditioned media, the vascular cells were exposed to anti‐P‐selectin, anti‐E‐selectin, anti‐ICAM‐1, and anti‐VCAM‐1 to detect the corresponding adhesive proteins on their surfaces. Breast cancer cells are known to bind to these adhesive proteins. Of the four proteins evaluated, E‐selectin was consistently found on more cell surfaces (∼30%) of bone‐derived vascular endothelial cells (BVECs) when exposed to the immature CM whereas vascular endothelial cells from marrow (MVECs) did not show this response to either immature CM or mature CM. These studies suggest that the BVEC blood vessels near immature bone cells express more surface adhesive protein that could enhance entrapment and extravasation of breast cancer cells. Once cancer cells have undergone extravasation into marrow adjacent to bone, they could be readily attracted to nearby bone surfaces. J. Cell. Biochem. 98: 1221–1229, 2006. © 2006 Wiley‐Liss, Inc.