bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of muscarinic receptor subtypes and interstitial cells of Cajal in the gastrointestinal tract of healthy dairy cows
Authors: Stoffel Michael H. , Monnard Christel Wicki , Steiner Adrian , Mevissen Meike , Meylan Mireille
Published: December 2006

Objective—To describe the distribution of muscarinic receptor subtypes M1 to M5 and interstitial cells of Cajal (ICCs) in the gastrointestinal tract of healthy dairy cows.

Sample Population—Full-thickness samples were collected from the fundus, corpus, and pyloric part of the abomasum and from the duodenum, ileum, cecum, proximal loop of the ascending colon, and both external loops of the spiral colon of 5 healthy dairy cows after slaughter.

Procedures—Samples were fixed in paraformaldehyde and embedded in paraffin. Muscarinic receptor subtypes and ICCs were identified by immunohistochemical analysis.

Results—Staining for M1 receptors was found in the submucosal plexus and myenteric plexus. Antibodies against M2 receptors stained nuclei of smooth muscle cells only. Evidence of M3 receptors was found in the lamina propria, in intramuscular neuronal terminals, on intermuscular nerve fibers, and on myocytes of microvessels. There was no staining for M4 receptors. Staining for M5 receptors was evident in the myocytes of microvessels and in smooth muscle cells. The ICCs were detected in the myenteric plexus and within smooth muscle layers. Distribution among locations of the bovine gastrointestinal tract did not differ for muscarinic receptor subtypes or ICCs.

Conclusions and Clinical Relevance—The broad distribution of M1, M3, M5, and ICCs in the bovine gastrointestinal tract indicated that these components are likely to play an important role in the regulation of gastrointestinal tract motility in healthy dairy cows. Muscarinic receptors and ICCs may be implicated in the pathogenesis of motility disorders, such as abomasal displacement and cecal dilatation-dislocation.
Postprandial changes in leptin concentrations of cerebrospinal fluid in dogs during development of obesity
Authors: Nishii Naohito , Nodake Hiroyuki , Takasu Masaki , Soe Okkar , Ohba Yasunori , Maeda Sadatoshi , Ohtsuka Yoshihiko , Honjo Tsutomu , Saito Masayuki , Kitagawa Hitoshi
Published: December 2006

Objective—To evaluate postprandial changes in the leptin concentration of CSF in dogs during development of obesity.

Animals—4 male Beagles.

Procedures—Weight gain was induced and assessments were made when the dogs were in thin, optimal, and obese body conditions (BCs). The fat area at the level of the L3 vertebra was measured via computed tomography to assess the degree of obesity. Dogs were evaluated in fed and unfed states. Dogs in the fed state received food at 9 AM. Blood and CSF samples were collected at 8 AM, 4 PM, and 10 PM.

Results—Baseline CSF leptin concentrations in the thin, optimal, and obese dogs were 24.3 ± 2.7 pg/mL, 86.1 ± 14.7 pg/mL, and 116.2 ± 47.3 pg/mL, respectively. In the thin BC, CSF leptin concentration transiently increased at 4 PM. In the optimal BC, baseline CSF leptin concentration was maintained until 10 PM. In the obese BC, CSF leptin concentration increased from baseline value at 4 PM and 10 PM. Correlation between CSF leptin concentration and fat area was good at all time points. There was a significant negative correlation between the CSF leptin concentration–to–serum leptin concentration ratio and fat area at 4 PM; this correlation was not significant at 8 AM and 10 PM.

Conclusions and Clinical Relevance—Decreased transport of leptin at the blood-brain barrier may be 1 mechanism of leptin resistance in dogs. However, leptin resistance at the blood-brain barrier may not be important in development of obesity in dogs.
Evaluation of recombinant human thyroid-stimulating hormone to test thyroid function in dogs suspected of having hypothyroidism
Authors: Boretti Felicitas S. , Sieber-Ruckstuhl Nadja S. , Favrot Claude , Lutz Hans , Hofmann-Lehmann Regina , Reusch Claudia E.
Published: December 2006

Objective—To evaluate the use of recombinant human (rh) thyroid-stimulating hormone (TSH) in dogs with suspected hypothyroidism.

Animals—64 dogs with clinical signs of hypothyroidism.

Procedures—Dogs received rhTSH (75 μg/dog, IV) at a dose independent of their body weight. Blood samples were taken before and 6 hours after rhTSH administration for determination of total serum thyroxine (T4) concentration. Dogs were placed into 1 of 3 groups as follows: those with normal (ie, poststimulation values indicative of euthyroidism), unchanged (ie, poststimulation values indicative of hypothyroidism; no thyroid gland stimulation), or intermediate (ie, poststimulation values between unchanged and normal values) post-TSH T4 concentrations. Serum canine TSH (cTSH) concentration was determined in prestimulation serum (ie, before TSH administration).

Results—14, 35, and 15 dogs had unchanged, normal, and intermediate post-TSH T4 concentrations, respectively. Basal T4 and post-TSH T4 concentrations were significantly different among groups. On the basis of basal serum T4 and cTSH concentrations alone, 1 euthyroid (normal post-TSH T4, low basal T4, and high cTSH concentrations) and 1 hypothyroid dog (unchanged post-TSH T4 concentration and low to with-in reference range T4 and cTSH concentrations) would have been misinterpreted as hypothyroid and euthyroid, respectively. Nine of the 15 dogs with intermediate post-TSHT4 concentrations had received medication known to affect thyroid function prior to the test, and 2 of them had severe nonthyroidal disease.

Conclusions and Clinical Relevance—The TSH-stimulation test with rhTSH is a valuable diagnostic tool to assess thyroid function in selected dogs in which a diagnosis of hypothyroidism cannot be based on basal T4 and cTSH concentrations alone.
Modeled detection time for surveillance for foot-and-mouth disease virus in bulk tank milk
Authors: Thurmond Mark C. , Perez Andrés M.
Published: December 2006

Objective—To estimate when foot-and-mouth disease virus (FMDV) would first be detected in bulk tank milk of dairies after exposure to FMDV.

Sample Population—Hypothetical dairy herds milking 100, 500, or 1,000 cows.

Procedures—For each day after herd exposure to FMDV, infection, milk yield, and virolactia were simulated for individual cows with low and high rates of intraherd transmission to estimate when a PCR assay would detect virus in bulk tank milk. Detection limits were based on assumptions for the number of virus genomes per milliliter of milk and for analytical sensitivity of a PCR assay.

Results—A mean of 10% of the cows was predicted to have FMD lesions from 7 to 8 days and from 13.5 to 15 days after herd exposure for herds with high and low intraherd transmission rates, respectively. Herd bulk milk volume decreased by 10% by 8.5 to 9.5 days and by 15 to 16.5 days after herd exposure for herds with high and low transmission rates, respectively. Mean times by which FMDV would be first detected in bulk milk were 2.5 days and 6.5 to 8 days after herd exposure, which were extended for 10 to 11 days and 17 to 18 days for herds with high and low transmission rates, respectively.

Conclusions and Clinical Relevance—PCR screening of bulk milk for FMDV would likely detect FMDV in dairy herds several days sooner than might be expected for owner reporting of clinical signs and thus should be worthy of consideration for regional, national, or global FMD surveillance.
Detection of novel papillomaviruslike sequences in paraffin-embedded specimens of invasive and in situ squamous cell carcinomas from cats
Authors: Nespeca Gilles , Grest Paula , Rosenkrantz Wayne S. , Ackermann Mathias , Favrot Claude
Published: December 2006

Objective—To detect and partially characterize papillomavirus (PV) DNA in squamous cell carcinoma (SCC) tumor specimens from cats.

Sample Population—54 formalin-fixed paraffinembedded skin biopsy specimens were examined. Specimens originated from Bowenoid in situ SCC (BISC; n = 21), invasive SCC (22), and skin affected by miscellaneous nonneoplastic conditions (11).

Procedures—Samples from each tissue block underwent DNA extraction after deparaffinization, and PCR assays were performed. Two sets of primers derived from PV E1 were used. The first set of primers was designed for the narrow-range PCR assay and was able to generate amplification products of feline PV (FePV), canine oral PV, or closely related PVs. The second set of primers was selected for the broad-range PCR assay because of its ability to amplify DNA from 64 human PVs. Sequence analysis of each amplified DNA was performed.

Results—1 of the 21 specimens of BISC was positive for PV DNA on the basis of narrow-range PCR assay results, whereas all the other specimens (BISC, invasive SCC, and controls) had negative results for PV DNA. In contrast, 5 of 21 BISC specimens and 4 of 22 invasive SCC specimens were positive for PV DNA on the basis of broad-range PCR assay results. Sequence analysis revealed that only 1 specimen was infected by a virus closely related to classic FePV. In the 8 other specimens positive for PV DNA, DNA of unknown PVs was uncovered.

Conclusions and Clinical Relevance—Bowenoid in situ SCC and invasive SCC of cats may be associated with PVs of genetic diversity.
Monitoring responses by use of five-color flow cytometry in subsets of peripheral T cells obtained from cattle inoculated with a killed Mycobacterium avium subsp paratuberculosis vaccine
Authors: Platt Ratree , Roth James A. , Royer Ryan L. , Thoen Charles O.
Published: December 2006

Objective—To monitor by use of 5-color flow cytometry the antigen-specific responses of subsets of peripheral T cells in cattle inoculated with a killed Mycobacterium avium subsp paratuberculosis (MAP) vaccine and to compare results with those for 2 established cell-mediated immunity assays.

Animals—45 female Holstein cattle with negative results for MAP in skin tests conducted at time of inoculation with MAP.

Procedures—Cattle were allocated to 4 groups. Cattle of group 1 (n = 12) were 0 to 3 months old and inoculated with a killed MAP vaccine. The 10 cattle of group 2 were the same age as those in group 1 but were not inoculated with MAP vaccine. The 11 cattle of group 3 were 9 to 12 months old and inoculated with killed MAP vaccine. The 12 cattle of group 4 were the same age as those in group 3 but were not inoculated with MAP vaccine.

Results—Flow cytometry identified T-cell subsets that responded specifically to the recall antigen. Results of assays for CD25 expression and wholeblood interferon-γ had the strongest correlation with results for skin tests as well as results with each other. Intracellular expression of interferon-γ was not correlated as well with results for the other tests.

Conclusions and Clinical Relevance—Flow cytometry can be useful for characterizing the immune response after administration of MAP vaccine and should be evaluated with regard to its sensitivity and specificity when used in detecting cattle naturally infected with MAP.
Analysis of reports of human exposure to Micotil 300 (tilmicosin injection)
Authors: Veenhuizen Melissa F. , Wright Theressa J. , McManus Robert F. , Owens Jane G.
Published: December 2006

Objective—To identify clinical signs associated with and outcome of human exposure to Micotil 300 (tilmicosin injection).

Design—Retrospective case series.

Study Population—Reports of 3,168 human exposures to Micotil 300.

Procedures—Reports of human exposure to Micotil 300 submitted to the Elanco Animal Health Pharmacovigilance Unit between March 1992 and March 2005 were reviewed.

Results—At least 1 clinical sign was described in 1,404 (44%) reports, whereas the remaining 1,764 (56%) exposures were presumably asymptomatic. Eighty percent of exposures involved males; mean age was 38 years. Sixty-one percent of exposures were a result of accidental injection, with injection site pain, bleeding, swelling, or inflammation being the most common signs, followed by nausea, tachycardia, dizziness, anxiety, an abnormal taste, headache, lightheadedness, limb pain, paresthesia, chest pain, and soreness. Only 156 (5%) reports involved serious adverse effects (ie, tachycardia, bradycardia, hypertension, hypotension, heart disorder, chest pain, tachypnea, or death). There were reports of 13 deaths following tilmicosin exposure, but only 2 of those deaths were related to accidental exposure. Time to onset of clinical signs was ≤ 60 minutes in 63 of the 156 (40%) reports involving serious adverse effects.

Conclusions and Clinical Relevance—Results suggest that the overall risk of accidental human exposure to tilmicosin resulting in serious adverse effects is low (approx 2 people for every 1 million doses administered). Nevertheless, safe handling and proper use should be emphasized.
Outcome associated with use of a percutaneously controlled hydraulic occluder for treatment of dogs with intrahepatic portosystemic shunts
Authors: Adin Christopher A. , Sereda Colin W. , Thompson Margaret S. , Wheeler Jason L. , Archer Linda L.
Published: December 2006

Objective—To evaluate efficacy of a hydraulic occluder (HO) used for treatment of dogs with an intrahepatic portosystemic shunt (IHPSS).

Design—Prospective study.

Animals—10 dogs with an IHPSS.

Procedures—Serum biochemical and postprandial bile acids (PPBA) analyses and transcolonic scintigraphy were performed before surgery. Laparotomy was performed, and an uninflated HO was placed around the portal vein branch leading to the IHPSS. After surgery, 0.9% NaCl solution was injected into subcutaneous injection ports at 2, 4, 6, and 8 weeks to achieve staged occlusion of the HO. Serum biochemical analyses, PPBA analysis, and scintigraphy were performed 2 weeks after occlusion. Serum biochemical analyses were repeated 1 year after surgery.

Results—Implant revision was required in 3 dogs because of rupture of the HO (n = 2) or detachment of the actuating tubing (1). Serum biochemical values and clinical signs improved in all dogs after surgery. Six of 10 dogs had PPBA concentration within reference range 2 weeks after occlusion, and 2 additional dogs had concentrations within reference range at 1 year. Only 5 of 10 dogs had complete resolution of portosystemic shunting 2 weeks after occlusion. Two dogs were lost to follow-up, and 8 dogs remained alive with no recurrence of clinical signs at a median of 22 months after surgery.

Conclusions and Clinical Relevance—Use of the HO appeared to be an effective method for surgical treatment for dogs with IHPSS, although problems with implant reliability indicate a need for modifications in design and manufacturing.
Effects of caloric restriction and a moderate or intense physiotherapy program for treatment of lameness in overweight dogs with osteoarthritis
Authors: Mlacnik Evamaria , Bockstahler Barbara A. , Müller Marion , Tetrick Mark A. , Nap Richard C. , Zentek Jürgen
Published: December 2006

Objective—To evaluate the effects of a weight reduction program combined with a basic or more complex physical therapy program including transcutaneous electric nerve stimulation on lameness in overweight dogs with osteoarthritis.

Design—Nonblinded prospective randomized clinical trial.

Animals—29 adult overweight or obese dogs with a body condition score of 4/5 or 5/5 and clinical and radiographic signs of osteoarthritis.

Procedures—A weight-loss program was initiated for all dogs. One group received caloric restriction and a home-based physical therapy program. The other group received the identical dietetic protocol and an intensive physical therapy program including transcutaneous electrical nerve stimulation. Lameness was assessed clinically and by kinetic gait analysis on a treadmill with 4 force plates to measure symmetry of ground reaction forces (GRFs) of the affected and contralateral limbs in bimonthly intervals for 6 months.

Results—Significant weight loss was achieved in both groups; however, greater weight reduction was attained by dogs treated with caloric restriction and intensive physiotherapy. Mobility and symmetry indices of GRFs were improved after 6 months; the best outcome was detected in the group receiving energy restriction combined with intensive physical therapy.

Conclusions and Clinical Relevance—Caloric restriction combined with intensive physical therapy improved mobility and facilitated weight loss in overweight dogs. The combination of dietetic and physical therapy may help to improve the health status more efficiently than dietetic treatment alone.
Evaluation of plasma protein C activity for detection of hepatobiliary disease and portosystemic shunting in dogs
Authors: Toulza Olivier , Center Sharon A. , Brooks Marjory B. , Erb Hollis N. , Warner Karen L. , Deal Wendy
Published: December 2006

Objective—To determine the diagnostic value of protein C (PC) for detecting hepatobiliary disease and portosystemic shunting (PSS) in dogs.

Design—Prospective study.

Animals—238 clinically ill dogs with (n = 207) and without (31) hepatobiliary disease, including 105 with and 102 without PSS.

Procedures—Enrollment required routine hematologic, serum biochemical, and urine tests; measurement of PC activity; and a definitive diagnosis. Total serum bile acids (TSBA) concentration and coagulation status, including antithrombin activity, were determined in most dogs. Dogs were grouped into hepatobiliary and PSS categories. Specificity and sensitivity were calculated by use of a PC cutoff value of 70% activity.

Results—Specificity for PC activity and TSBA concentrations was similar (76% and 78%, respectively). Best overall sensitivity was detected with TSBA, but PC activity had high sensitivity for detecting PSS and hepatic failure. Protein C activity in microvascular dysplasia (MVD; PC ≥ 70% in 95% of dogs) helped differentiate MVD from portosystemic vascular anomalies (PSVA; PC < 70% in 88% of dogs). A receiver operating characteristic curve (PSVA vs MVD) validated a useful cutoff value of < 70% activity for PC.

Conclusions and Clinical Relevance—Combining PC with routine tests improved recognition of PSS, hepatic failure, and severe hepatobiliary disease and signified a grave prognosis when coupled with hyperbilirubinemia and low antithrombin activity in hepatic failure. Protein C activity can help prioritize tests used to distinguish PSVA from MVD and sensitively reflects improved hepatic-portal perfusion after PSVA ligation.
Incomplete rupture of the gastrocnemius and superficial digital flexor muscles in a Quarter Horse stallion
Authors: Toppin D. Scott , Lori David N.
Published: December 2006

Case Description—A 16-year-old 500-kg (1,100-lb) Quarter Horse stallion was examined because of acute severe lameness involving the left hind limb.

Clinical Findings—Examination revealed signs of failure (concurrent flexion of the tarsus and extension of the stifle [femorotibial] joint) of the caudal component of the reciprocal apparatus. Results of radiographic evaluation ruled out fracture or joint injury as causes of the lameness. During the next 48 hours, the reciprocal apparatus on the left hind limb progressively deteriorated until the horse became non–weight bearing on the limb.

Treatment and Outcome—The horse wore a full-limb splint over a Robert-Jones bandage on the plantar aspect of the limb for 30 days. Thirty-four days after the initial injury, the horse had weak function of the reciprocal apparatus and limited ability to bear weight. Six days after removal of the splint, laminitis developed in the contralateral hind limb. The horse was managed with a sling for 5 weeks, during which time deep digital flexor tendon contracture developed. Eleven weeks after the initial injury, the stallion was discharged from the hospital and walking comfortably with a 1-cm-high block under the heel of the left hind foot.

Clinical Relevance—Incomplete failure of the caudal component of the reciprocal apparatus is an unusual injury that likely occurs during a fall with a hind limb extended under the body, resulting in forced extension of the muscle while it is engaged in contraction. Conservative management of this injury in a heavily muscled adult horse is possible.
Adaptive unknown input observer approach for aircraft actuator fault detection and isolation
Authors: Wang Dan , Lum Kai‐Yew
Published: December 2006

In this paper, an adaptive unknown input observer (UIO) approach is developed to detect and isolate aircraft actuator faults. In a multiple‐model scheme, a bank of parallel observers are constructed, each of which is based on a model that describes the system in the presence of a particular actuator fault. The observers are constructed based on a modified form of the standard UIO to generate fault‐dependant residual signals, such that when a model matches the system, the residual signal will be zero. Otherwise, the residual will be definitely non‐zero and governed uniquely by the faulty signal. For locked actuators and loss of actuator effectiveness, in which the locked position and the reduced effectiveness are additional unknowns, we develop an adaptive scheme to estimate these unknown parameters. To the best of our knowledge, this is the first adaptive UIO presented. We prove that the proposed adaptive algorithms guarantee that both the residual signals and the estimation errors of the unknown parameters converge exponentially when a model matches the plant. By further designing a model‐matching index, the fault can be isolated accurately. A condition for the approach is that for annth order system, there must benindependent measurements available. This requirement limits the applicability of our proposed approach. The condition is certainly satisfied by all state‐feedback control systems. However, for some other systems, extra efforts may be needed to increase the number of measurements. The method is applied to a linear model of the F‐16 aircraft with controller. The results show that the approach is effective. Copyright © 2006 John Wiley & Sons, Ltd.
A mixed‐integer optimization framework for de novo peptide identification
Authors: DiMaggio, Peter A. , Floudas Christodoulos A.
Published: December 2006

A novel methodology for the de novo identification of peptides by mixed‐integer optimization and tandem mass spectrometry is presented in this article. The various features of the mathematical model are presented and examples are used to illustrate the key concepts of the proposed approach. Several problems are examined to illustrate the proposed method's ability to address (1) residue‐dependent fragmentation properties and (2) the variability of resolution in different mass analyzers. A preprocessing algorithm is used to identify important m/z values in the tandem mass spectrum. Missing peaks, resulting from residue‐dependent fragmentation characteristics, are dealt with using a two‐stage algorithmic framework. A cross‐correlation approach is used to resolve missing amino acid assignments and to identify the most probable peptide by comparing the theoretical spectra of the candidate sequences that were generated from the MILP sequencing stages with the experimental tandem mass spectrum. © 2006 American Institute of Chemical Engineers AIChE J 2007
Use of limestone karst forests by Bornean orangutans (Pongo pygmaeus morio) in the Sangkulirang peninsula, east Kalimantan, Indonesia
Authors: Marshall Andrew J. , Salas Leonardo A. , Stephens Suzette , Nardiyono  , Engström Linda , Meijaard Erik , Stanley Scott A.
Published: December 2006

The Indonesian province of East Kalimantan is home to some of the largest remaining contiguous tracts of lowland Dipterocarp forest on the island of Borneo. Nest surveys recently conducted in these forests indicated the presence of a substantial population of Eastern Bornean orangutans (Pongo pygmaeus morio) in the Berau and East Kutai regencies in the northern half of the province. The Sangkulirang Peninsula contains extensive limestone karst forests in close proximity to the lowland Dipterocarp forests inhabited by orangutans in these regencies. Orangutans have been sighted in these limestone karst forests, but the importance of this forest type for orangutans has been unclear. Therefore, we conducted 49 km of nest surveys in limestone karst forest to obtain the first quantitative estimates of orangutan densities in this habitat, and walked 28 km of surveys in nearby lowland Dipterocarp forests for comparison. We also gathered basic ecological data along our transects in an attempt to identify correlates of orangutan abundance across these habitat types. Undisturbed limestone karst forests showed the lowest orangutan densities (147 nests/km2, 0.82 indiv/km2), disturbed limestone forests had intermediate densities (301 nests/km2, 1.40 indiv/km2), and undisturbed lowland Dipterocarp forests contained the highest density (987 nests/km2, 5.25 indiv/km2), significantly more than the undisturbed limestone karst forests. This difference was not correlated with variation in liana abundance, fig stem density, or stump density (an index of forest disturbance). Therefore, other factors, such as the relatively low tree species diversity of limestone karst forests, may explain why orangutans appear to avoid these areas. We conclude that limestone karst forests are of low relevance for safeguarding the future of orangutans in East Kalimantan. Am. J. Primatol. 69:1–8, 2007. © 2006 Wiley‐Liss, Inc.
Living in forest fragments reduces group cohesion in diademed sifakas (Propithecus diadema) in eastern Madagascar by reducing food patch size
Authors: Irwin Mitchell T.
Published: December 2006

Forest fragmentation is thought to threaten primate populations, yet the mechanisms by which this occurs remain largely unknown. However, fragmentation is known to cause dietary shifts in several primate species, and links between food resource distribution and within‐group spatial dynamics are well documented. Thus, fragmentation has the potential to indirectly affect spatial dynamics, and these changes may present additional stresses to fragmented populations. I present the results from a 12‐month study of Propithecus diadema at Tsinjoarivo, eastern Madagascar, including two groups in fragments and two in continuous forest. Instantaneous data on activity and spatial position were collected during all‐day focal animal follows. Fragment groups had much lower cohesion, being more likely to have no neighbor within 5 and 10 m. For continuous forest groups, cohesion was highest in the rainy season (when food patches are large) and lowest in winter (when the animals rely on small‐crowned mistletoes), and the chance of having no neighbor within 5 m was positively correlated with mistletoe consumption. Thus their decreased cohesion in fragment groups is inferred to result from their increased reliance on mistletoes and other small resources, which causes them to spread out among multiple patches. This scenario is consistent with the reduced body mass of subordinate individuals (males and immatures) in fragments, and suggests the occurrence of steeper within‐group fitness gradients. Further research is necessary to determine whether these patterns apply to other primates; however, since fragmentation tends to cause the loss of the largest trees, many primates in fragments may lose their largest food resources and undergo similar behavioral shifts. Am. J. Primatol. 69:1–14, 2007. © 2006 Wiley‐Liss, Inc.
Photoluminescence and Conductivity of Self‐Assembled π–π Stacks of Perylene Bisimide Dyes
Authors: Chen Zhijian , Stepanenko Vladimir , Dehm Volker , Prins Paulette , Siebbeles Laurens D. A. , Seibt Joachim , Marquetand Philipp , Engel Volker , Würthner Frank
Published: December 2006

The self‐assembly of a new, highly fluorescent perylene bisimide dye 2 into π stacks, both in solution and condensed phase, has been studied in detail by NMR spectroscopy, vapor pressure osmometry (VPO), UV/Vis and fluorescence spectroscopy, differential scanning calorimetry (DSC), optical polarizing microscopy (OPM) and X‐ray diffraction. The NMR and VPO measurements revealed the formation of extended π–π stacks of the dye molecules in solution. The aggregate size determined from VPO and DOSY NMR measurements agree well with that obtained from the concentration and temperature‐dependent UV/Vis spectral data by employing the isodesmic model (equal K model). In the condensed state, dye 2 possesses a hexagonal columnar liquid crystalline (LC) phase as confirmed by X‐ray diffraction analysis. The columnar stacking of this dye has been further explored by atomic force microscopy (AFM). Well‐resolved columnar nanostructures of the compound are observed on graphite surface. A color‐tunable luminescence from green to red has been observed upon aggregation which is accompanied by an increase of the fluorescence lifetime and depolarization. The observed absorption properties can be explained in terms of molecular exciton theory. The charge transport properties of dye 2 have been investigated by pulse radiolysis‐time resolved microwave conductivity measurements and a 1D charge carrier mobility up to 0.42 cm2 V−1 s−1 is obtained. Considering the promising self‐assembly, semiconducting, and luminescence properties of this dye, it might serve as a useful functional material for nano(opto)electronics.
Importance of Interfacial Adsorption in the Biphasic Hydroformylation of Higher Olefins Promoted by Cyclodextrins: A Molecular Dynamics Study at the Decene/Water Interface
Authors: Sieffert Nicolas , Wipff Georges
Published: December 2006

We report herein a molecular dynamics study of the main species involved in the hydroformylation of higher olefins promoted by cyclodextrins in 1‐decene/water biphasic systems at a temperature of 350 K. The two liquids form a well‐defined sharp interface of approximately 7 Å width in the absence of solute; the decene molecules are generally oriented “parallel” to the interface where they display transient contacts with water. We first focused on rhodium complexes bearing water‐soluble TPPTS3− ligands (where TPPTS3− represents tris(m‐sulfonatophenyl)phosphine) involved in the early steps of the reaction. The most important finding concerned the surface activity of the “active” form of the catalyst [RhH(CO)(TPPTS)2]6−, the [RhH(CO)2(TPPTS)2]6− complex, and the key reaction intermediate [RhH(CO)(TPPTS)2(decene)]6− (with the olefin π‐coordinated to the metal center) which are adsorbed at the water side of the interface in spite of their −6 charge. The free TPPTS3− ligands themselves are also surface‐active, whereas the −9 charged catalyst precursor [RhH(CO)(TPPTS)3]9− prefers to be solubilized in water. The role of cyclodextrins was then investigated by performing simulations on 2,6‐dimethyl‐β‐cyclodextrin (“CD”) and its inclusion complexes with the reactant (1‐decene), a reaction product (undecanal), and the corresponding key reaction intermediate [RhH(CO)(TPPTS)2(decene)]6− as guests; they were all shown to be surface‐active and prefer the interface over the bulk aqueous phase. These results suggest that the biphasic hydroformylation of higher olefins takes place “right” at the interface and that the CDs promote the “meeting” of the olefin and the catalyst in this peculiar region of the solution by forming inclusion complexes “preorganized” for the reaction. Our results thus point to the importance of adsorption at the liquid/liquid interface in this important phase‐transfer‐catalyzed reaction.
Host‐Guest Interactions between N,N′‐Bis(ferrocenylmethylene)‐Diaminobutane and Benzenetetracarboxylic Dianhydride Bridged Bis(β‐cyclodextrin)s
Authors: Chen Xi , Liu Jing , Yan Jun‐Lin , Fang Yu
Published: December 2006

A novel water soluble ditopic guest, the quaternary ammonium salt of N,N′‐bis(ferrocenylmethylene)‐diami‐ nobutane (1), and a known water soluble ditopic host, benzenetetracarboxylic dianhydride bridged bis(β‐cyclo‐dextrin)s (2), have been synthesized and characterized. 1H NMR spectra and cyclic voltammogram (CV) studies revealed the host‐guest interactions between them in aqueous solution. The supramolecular interaction also exists in solid state as confirmed by the studies of the solid samples, which were obtained by frozen‐drying the solution samples, using FTIR spectroscopy and differential scanning calorimetry (DSC) techniques. TEM measurement demonstrated that wire‐shaped supramolecular aggregates exist in the aqueous solution of the two compounds. The lengths of the aggregates could reach micrometers.
Alkylation of Hydroquinone with tert‐Butyl Alcohol over Bis[(perfluoroalkyl)sulfonyl]imides Supported on MCM‐41
Authors: Yuan Yu‐Bin , Nie Jin , Zhang Zheng‐Bo , Zhou San‐Yi
Published: December 2006

Bis[(perfluoroalkyl)sulfonyl]imides [HN(SO2Rf)2, and Rf represents the perfluorinated alkyl group] supported on MCM‐41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2‐adsorption techniques. The supported catalysts, HN(SO2Rf)2/MCM‐41, were used as the catalysts for the tert‐butylation of hydroquinone (HQ) with tert‐butyl alcohol (TBA) in the liquid phase. A high yield (52.0%) of 2‐tert‐butyl hydroquinone (TBHQ) could be obtained in the presence of 5 mol% HN(SO2C4F9)2/MCM‐41 under the optimized reaction conditions and the heterogeneous catalyst could be recycled at least 6 times without substantial loss of activity.
Construction of a Novel 2D Polymer [Co(dmpzm)(dca)2]∞ from Reaction of a Mononuclear Complex [Co(dmpzm)Cl2] with Sodium Dicyanamide (dca) [dmpzm=bis(3,5‐dimethylpyrazolyl)methane]
Authors: Li Qiao‐Yun , Zhang Wen‐Hua , Li Hong‐Xi , Tang Xiao‐Yan , Lang Jian‐Ping , Zhang Yong , Wang Xin‐Yi , Gao Song
Published: December 2006

Reaction of CoCl2·6H2O with equimolar bis(3,5‐dimethylpyrazolyl)methane (dmpzm) produced a mononuclear adduct [Co(dmpzm)Cl2] (1). Treatment of 1 with sodium dicyanamide (dca) afforded a polymeric complex [Co(dmpzm)(μ‐dca)2]∞ (2). 1 and 2 were characterized by elemental analysis, IR spectra, thermogravimetric analysis and single‐crystal X‐ray diffraction. The cobalt atom in 1 adopts a distorted tetrahedral coordination geometry, bound to two N atoms of one dmpzm and two Cl atoms. Complex 2 has a 2D brick‐wall network (extended along the bc plane) in which the {[Co(dmpzm)(μ‐dca)]2}2n+n chains are interconnected by pairs of μ‐dca anions along the c axis. The magnetic properties of 1 and 2 were also investigated.
Synthesis and Crystal Structure of Two iso‐closo 11‐Vertex p‐Bromobenzoate Ruthenoborane Clusters: [(PPh3)(p‐BrC6H4CO2)2RuB10H8] and [(PPh3)2Ru(p‐BrC6H4CO2)‐(PPh3)RuB10H9]
Authors: Guo Qing‐Liang , Dou Jian‐Min , Wu Li‐Bin , Li Da‐Cheng , Wang Da‐Qi
Published: December 2006

The title clusters [(PPh3)(p‐BrC6H4CO2)2RuB10H8] (1) and [(PPh3)2Ru(PPh3)(p‐BrC6H4CO2)RuB10H9] (2) have been prepared and characterized by elemental analysis, FT‐IR, 1H, 13C NMR spectra and single‐crystal X‐ray diffraction analysis. The clusters crystallize in monoclinic system, space group C2/c, with a=2.569(4) nm, b=1.546(2) nm, c=1.927(3) nm, β=95.11(2)°, Z=8, V=7.622(21) nm3, Dc=1.533 Mg/m3, F(000)=3472, S=1.009, R=0.0418, wR=0.0775 and triclinic system, space group P‐1, with a=1.3142(3) nm, b=1.3761(3) nm, c=1.8503(4) nm, α=90.445(4)°, β=105.950(4)°, (=108.980(4)°, Z=2, V=3.0251(12) nm3, Dc=1.434 Mg/m3, F(000)=1316, S=1.007, R=0.0464, wR=0.1175, respectively for 1 and 2. In the structures, both of the clusters are based on a closo‐type C2v 1:2:4:2:2 RuB10 stack with the metal occupying the unique six‐connected apical position. In cluster 1, the metal center has three exo‐polyhedral ligands:one triphenylphosphine and two dative oxygen atoms of p‐bromobenzoates. The other oxygen atoms of two p‐bromobenzoate are additionally bonded to B(2) and B(3) atoms respectively, resulting in two exo‐cyclic five‐membered Ru‐O‐C‐O‐B rings and engendering a symmetrical conformation. The cluster 2 is a bimetallic species in which the second ruthenium is bound to the {RuB10} center via one Ru–Ru bond and two {RuHµB} bridges resulting in one closo distorted exo‐polyhedral Ru(1)‐ Ru(2)‐B(3)‐B(6) tetrahedron.
Comparison of 2D Fingerprint Methods for Multiple‐Template Similarity Searching on Compound Activity Classes of Increasing Structural Diversity
Authors: Tovar Andrea , Eckert Hanna , Bajorath Jürgen
Published: December 2006

We studied the similarity search performance of differently designed molecular fingerprints using multiple reference structures and different search strategies. For this purpose, nine compound activity classes were assembled that exclusively consisted of molecules with different core structures and that represented different levels of intra‐class structural diversity. Thus, there was a strict one‐to‐one correspondence between test compounds and core structures. Analysis of unique core structures was found to be a better measure of class diversity than distributions of simplified scaffolds. On increasingly diverse classes, a trainable fingerprint using a unique search strategy performed better than others tested herein. Overall, clear preferences were detected for nearest‐neighbor search strategies over fingerprint‐averaging techniques. Nearest‐neighbor searching that relied on selecting database compounds most similar to one of the reference structures often improved compound recovery over other averaging methods, but at the cost of decreasing the ability to detect hits that were structurally distinct from reference molecules.
The impact of factors beyond Breslow depth on predicting sentinel lymph node positivity in melanoma
Authors: Paek Sandra C. , Griffith Kent A. , Johnson Timothy M. , Sondak Vernon K. , Wong Sandra L. , Chang Alfred E. , Cimmino Vincent M. , Lowe Lori , Bradford Carol R. , Rees Riley S. , Sabel Michael S.
Published: December 2006

BACKGROUND.

In addition to Breslow depth, the authors previously described how increasing mitotic rate and decreasing age predicted sentinel lymph node (SLN) metastases in patients with melanoma. The objectives of the current study were to verify those previous results and to create a prediction model for the better selection of which patients with melanoma should undergo SLN biopsy.

METHODS.

The authors reviewed 1130 consecutive patients with melanoma in a prospective database who underwent successful SLN biopsy. After eliminating patients aged <16 years and patients who had melanomas that measured <1 mm, 910 remaining patients were reviewed for clinical and pathologic features and positive SLN status. Univariate association of patient and tumor characteristics with positive SLN status was explored by using standard logistic regression techniques, and the best multivariate model that predicted lymph node metastases was constructed by using a backward stepwise‐elimination technique.

RESULTS.

The characteristics that were associated significantly with lymph node metastasis were angiolymphatic invasion, the absence of regression, increasing mitotic rate, satellitosis, ulceration, increasing Breslow depth, decreasing age, and location (trunk or lower extremity compared with upper extremity or head/neck). Previously reported interactions between mitotic rate and age and between Breslow depth and age were confirmed. The best multivariate model included patient age (linear), angiolymphatic invasion, the number of mitoses (linear), the interaction between patient age and the number of mitoses, Breslow depth (linear), the interaction between patient age and Breslow depth, and primary tumor location.

CONCLUSIONS.

Younger age, increasing mitotic rate (especially in younger patients), increasing Breslow depth (especially in older patients), angiolymphatic invasion, and trunk or lower extremity location of the primary tumor were associated with a greater likelihood of positive SLN status. The current results support the use of factors beyond Breslow depth to determine the risk of positive SLN status in patients with cutaneous melanoma. Cancer 2007. © 2006 American Cancer Society
Myoblast fusion in Drosophila melanogaster is mediated through a fusion‐restricted myogenic‐adhesive structure (FuRMAS)
Authors: Kesper Dörthe Andrea , Stute Christiana , Buttgereit Detlev , Kreisköther Nina , Vishnu Smitha , Fischbach Karl‐Friedrich , Renkawitz‐Pohl Renate
Published: December 2006

During myogenesis in Drosophila embryos, a prominent adhesive structure is formed between precursor cells and fusion‐competent myoblasts (fcms). Here, we show that Duf/Kirre and its interaction partners Rols7 (found in founder myoblasts and growing myotubes) and Sns (found in fcms) are organized in a ring‐structure at the contact points of fcms with precursor cells, while cytoskeletal components like F‐actin and Titin are centered in this ring in both cell types. The cytoplasmic protein Blow colocalizes with the actin plugs in fcms after cell adhesion. Furthermore, the requirement of additional as yet unidentified components was demonstrated by using mammalian C2C12 myoblasts. In this study, we propose that the fusion‐restricted myogenic‐adhesive structure (FuRMAS) is pivotal in linking cell adhesion as well as local F‐actin assembly and dynamics to downstream events that ultimately lead to plasma membrane fusion. Moreover, we suggest that the FuRMAS may restrict the area of membrane breakdown. Developmental Dynamics 236:404–415, 2007. © 2006 Wiley‐Liss, Inc.
Syntheses, Characterization and Reactivity of Iron(II), Nickel(II), Copper(II) and Zinc(II) Complexes of the Ligand N,N,N′,N′‐Tetrakis(2‐pyridylmethyl)benzene‐1,3‐diamine (1,3‐tpbd) and Its Phenol Derivative 2,6‐Bis[bis(2‐pyridylmethyl)amino]‐p‐cresol (2,6‐tpcd)
Authors: Foxon Simon , Xu Jing‐Yuan , Turba Sabrina , Leibold Michael , Hampel Frank , Heinemann Frank W. , Walter Olaf , Würtele Christian , Holthausen Max , Schindler Siegfried
Published: December 2006

N,N,N′,N′‐Tetrakis(2‐pyridylmethyl)benzene‐1,3‐diamine (1,3‐tpbd), a bis(tridentate) ligand, its protonated derivative, [1,3‐tpbdH2]2+, and a series of new dinuclear complexes [Fe2(1,3‐tpbd)(CH3CN)6](ClO4)4·(CH3CN)2·(H2O)0.5 (1), [Fe2(1,3‐tpbd)(DMF)6](ClO4)4 (2), [Ni2(1,3‐tpbd)(DMF)6](ClO4)4 (3), [Zn2(1,3‐tpbd)(CH3CN)2(SO3CF3)2(H2O)](SO3CF3)2 (4), [Zn2(1,3‐tpbd)Cl4]·H2O (5), [CuZn(1,3‐tpbd)Cl4] (7) and the tetranuclear copper(II) complex [Cu2(1,3‐tpbd)2(H2O)2](ClO4)4·2H2O (8) have been prepared and structurally characterized. Complex 8, a so called “dimetallocyclophane”, interestingly only formed in the presence of zinc ions and not when copper(II) ions were mixed stoichiometrically (1:1 mixtures) under aerobic conditions. Theoretical calculations provide evidence for the formation of a side‐on dinuclear peroxido copper complex during the oxidation of the (1,3‐tpbd)copper(I) complex. A possible reaction product, the dinuclear copper complex [Cu2(2,6‐tpcd)(H2O)(Cl)](ClO4)2·2H2O (9) of a phenolate derivative of 1,3‐tpbd was synthesized and structurally characterized independently from oxidation reactions from copper(II) perchlorate and the ligand 2,6‐bis[bis(2‐pyridylmethyl)amino]‐p‐cresol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Hippocampal gene expression analysis using the ORESTES methodology shows that homer 1a mRNA is upregulated in the acute period of the pilocarpine epilepsy model
Authors: Avedissian Marcelo , Longo Beatriz M. , Jaqueta Carolina B. , Schnabel Beatriz , Paiva Paulo B. , Mello Luiz Eugênio A.M. , Briones Marcelo R.S.
Published: December 2006

In the study of temporal lobe epilepsy (TLE) the characterization of genes expressed in the hippocampus is of central importance for understanding their roles in epileptogenic mechanisms. Although several large‐scale studies on TLE gene expression have been reported, precise assignment of individual genes associated with this syndrome is still debatable. Here we investigated differentially expressed genes by comparison of mRNAs from normal and epileptic rat hippocampus in the pilocarpine model of epilepsy. For this we used a powerful EST sequencing methodology, ORESTES (Open Reading frame Expressed Sequence Tags), which generates sequence datasets enriched for mRNAs open reading frames (ORFs) rather than simple 5′ and 3′ ends of mRNAs. Analysis of our sequences shows that ORESTES readily enables the identification of epilepsy associated ORFs. PFAM analysis of protein motifs present in our ORESTES epilepsy database revealed diverse important protein family domains, such as cytoskeletal, cell signaling and protein kinase domains, which could be involved in processes underlying epileptogenesis. More importantly, we show that the expression of homer 1a, known to be coupled to mGluR and NMDA synaptic transmission, is associated with pilocarpine induced status epilepticus (SE). The combined use of the pilocarpine model of epilepsy with the ORESTES technique can significantly contribute to the identification of specific genes and proteins related to TLE. This is the first study applying a large‐scale method for rapid shotgun sequencing directed to ORFs in epilepsy research. © 2006 Wiley‐Liss, Inc.
The homology and phylogeny of chondrichthyan tooth enameloid
Authors: Gillis J. Andrew , Donoghue Philip C.J.
Published: December 2006

A systematic SEM survey of tooth microstructure in (primarily) fossil taxa spanning chondrichthyan phylogeny demonstrates the presence of a superficial cap of single crystallite enameloid (SCE) on the teeth of several basal elasmobranchs, as well as on the tooth plates of Helodus (a basal holocephalan). This suggests that the epithelial–mesenchymal interactions required for the development of enameloid during odontogenesis are plesiomorphic in chondrichthyans, and most likely in toothed gnathostomes, and provides phylogenetic support for the homology of chondrichthyan and actinopterygian enameloid. Along the neoselachian stem, we see a crownward progression, possibly modulated by heterochrony, from a monolayer of SCE lacking microstructural differentiation to the complex triple‐layered tooth enameloid fabric of neoselachians. Finally, the occurrence of fully‐differentiated neoselachian enameloid microstructure (including compression‐resistant tangle fibered enameloid and bending‐resistant parallel fibered enameloid) in Chlamydoselachus anguineus, a basal Squalean with teeth that are functionally “cladodont,” is evidence that triple‐layered enameloid microstructure was a preadaption to the cutting and gouging function of many neoselachian teeth, and thus may have played an integral role in the Mesozoic radiation of the neoselachian crown group. J. Morphol, 2006. © 2006 Wiley‐Liss, Inc.
Stability of fused versus nonfused THA Femoral impaction grafts
Authors: Heiner Anneliese D. , Callaghan John J. , Brown Thomas D.
Published: December 2006

Impaction grafting for THA involves compacting morselized cancellous bone (MCB) into a cavitary defect to build up bone stock. Ideally, the MCB subsequently remodels into a new contiguous cancellous lattice. A recent laboratory model of MCB fusion allows simulating an impaction graft construct in this ideal eventual clinical state. The purpose of the present study was to determine the relative stability of femoral impaction graft constructs in which the MCB has fused versus that for MCB in the freshly impacted nonfused condition. Cemented femoral impaction graft constructs were created in composite femurs. For fused constructs, the MCB was mixed with an amine epoxy that causes the MCB to set up into a contiguous structure biomechanically comparable to intact cancellous bone in compression. The constructs were loaded with 500,000 physiologic gait cycles. Three‐dimensional motion was measured between the femur and the stem. The fused femoral impaction grafts were much more stable than the nonfused grafts at the proximal stem location, but MCB fusion had only a modest effect on distal stem stability. These results indicate that most of the opportunity to reduce femoral stem micromotion and migration lies proximal, and that steps to enhance impaction graft remodeling and fusion are most effectively focused proximally. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007