bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-Inflammatory Activity and Gastric Lesions Induced by Zinc-Tenoxicam
Authors: Nascimento Jorge Willian L. , Santos Luiz Henrique , Nothenberg Michael S. , Coelho Márcio M. , Oga Seizi , Tagliati Carlos A.
Published: April 2003

Oral administration of tenoxicam or zinc-tenoxicam complex inhibited to a similar extent carrageenin-induced paw oedema and granulomatous tissue formation in rats as well as the acetic acid induced writhing response in mice. Gastric lesions induced by oral administration of zinc-tenoxicam were reduced in number and severity when compared with those induced by tenoxicam or the co-administration of tenoxicam and zinc acetate. However, after intraperitoneal administration, both zinc-tenoxicam and tenoxicam plus zinc acetate induced a reduced number of gastric lesions as compared with tenoxicam.
Quercetin Potentiates L-Dopa Reversal of Drug-Induced Catalepsy in Rats: Possible COMT/MAO Inhibition
Authors: Singh Amanpreet , Naidu Pattipati S. , Kulkarni Shrinivas K.
Published: April 2003

L-Dopa plus carbidopa treatment remains the first-line therapy in Parkinson’s disease. The use of catechol-O-methyltransferase (COMT) and/or monoamine oxidase (MAO) inhibitors as an adjunct to L-dopa therapy has yielded varying degrees of success. Quercetin, a flavonoid present in many plants, is reported to inhibit COMT and MAO activities, the key enzymes involved in the metabolism of dopamine. In the present study we have studied the effect of quercetin on the L-dopa plus carbidopa combination against perphenazine and reserpine-induced catalepsy in rats. Neuroleptic-induced catalepsy is a widely accepted animal model for testing the drugs used in parkinsonism. Catalepsy in rats was induced by administration of perphenazine (5 mg/kg i.p.) or reserpine (2.5 mg/kg i.p.) + α-methyl-p-tyrosine (200 mg/kg i.p.). Catalepsy in animals was assessed by using the bar test. The quercetin dose (25–100 mg/kg, p.o.) dependently reversed perphenazine- as well as reserpine-induced catalepsy. When quercetin was combined with a subthreshold dose of L-dopa plus carbidopa, the anticatatonic effect was potentiated. Pretreatment with a central COMT inhibitor, 3,5-dinitrocatechol (OR-486) (10 mg/kg p.o.), or a MAO-B inhibitor, selegiline (5 mg/kg i.p.), also potentiated the actions of threshold dose of quercetin against perphenazine- or reserpine-induced catalepsy. On the other hand adenosine (100 mg/kg i.p.), which is known to decrease the release of catecholamines through an action on presynaptic A1 receptors, partly reversed the protective effect of quercetin against perphenazine-induced catalepsy. Quercetin through its COMT and MAO enzyme-inhibiting properties might potentiate the anticatatonic effect of L-dopa plus carbidopa treatment. The results of the present study strongly suggest that quercetin could serve as an effective adjunct to L-dopa therapy in Parkinson’s disease.
In vitro Activity of Azithromycin in Combination with Amikacin, Ceftazidime, Ciprofloxacin or Imipenem against Clinical Isolates of Acinetobacter baumannii
Authors: Fernández-Cuenca Felipe , Martínez-Martínez Luis , Pascual Alvaro , Perea Evelio J.
Published: April 2003

The in vitro activity of the two-drug combinations of azithromycin with amikacin, ceftazidime, ciprofloxacin or imipenem against five clonally unrelated strains of Acinetobacter baumannii were evaluated. Synergy studies were performed by the checkerboard microtiter method. The fractional inhibitory concentration (FIC) index was calculated for each drug combination. None of the four combinations tested was antagonistic. The combination of azithromycin and ceftazidime was synergistic (FIC index ≤0.5) for one strain and partially synergistic (FIC index 0.75) for another strain. An additive effect (FIC index = 1) was observed for the combinations of azithromycin with imipenem (two strains) or ceftazidime (one strain). The activities of the other combinations were indifferent (FIC index range from 1.5 to 2.5). It is concluded that azithromycin combined with ceftazidime has moderate synergistic activity against some multiresistant A. baumannii.
A Large, Community-Based, Open-Label Trial of Donepezil in the Treatment of Alzheimer’s Disease
Authors: Relkin Norman R. , Reichman William E. , Orazem John , McRae Thomas
Published: April 2003

This phase III trial was conducted to evaluate the safety and efficacy of donepezil in Alzheimer’s disease (AD) patients with a greater range of comorbid conditions and concomitant medication use than those previously evaluated in placebo-controlled studies. Patients (n = 1,035) with mild to moderate probable or possible AD were enrolled from 255 sites in the USA; 894 (86%) completed the trial. Mean age was 74.9 years (± 7.8); baseline standardized Mini-Mental State Examination (sMMSE) score was 19.77 (± 5.4). Nearly all patients had at least 1 prior or comorbid medical condition (97%) or were taking at least 1 concomitant medication (93%). Safety assessments included recording treatment-emergent adverse events (AEs). To confirm comparability with past studies, efficacy was measured using the sMMSE. Over the 12-week study period, the mean sMMSE score increased by 1.54 points over baseline (p < 0.0001) in donepezil-treated patients. Most AEs (64%) were mild, and the occurrence of cholinergic-induced AEs was significantly lower after a dose increase at 4 weeks than that seen with a dose increase after 1 week in previous trials. Risk ratios for gastrointestinal side effects were not significantly increased by the use of aspirin or nonsteroidal anti-inflammatory drugs. Risk ratios for bradycardia were not significantly increased by the use of beta-blockers, nondihydropyridine calcium channel blockers or digoxin. Therefore, donepezil improved cognition, as measured by the sMMSE, and was well tolerated despite high concomitant medication use and extensive comorbidity. These results highlight donepezil as a safe and effective treatment for AD patients typically seen by community-based physicians.
Neural Correlates of Lexical Access during Visual Word Recognition
Authors: Binder J. R. , McKiernan K. A. , Parsons M. E. , Westbury C. F. , Possing E. T. , Kaufman J. N. , Buchanan L.
Published: April 2003

People can discriminate real words from nonwords even when the latter are orthographically and phonologically word-like, presumably because words activate specific lexical and/or semantic information. We investigated the neural correlates of this identification process using event-related functional magnetic resonance imaging (fMRI). Participants performed a visual lexical decision task under conditions that encouraged specific word identification: Nonwords were matched to words on orthographic and phonologic characteristics, and accuracy was emphasized over speed. To identify neural responses associated with activation of nonsemantic lexical information, processing of words and nonwords with many lexical neighbors was contrasted with processing of items with no neighbors. The fMRI data showed robust differences in activation by words and word-like nonwords, with stronger word activation occurring in a distributed, left hemisphere network previously associated with semantic processing, and stronger nonword activation occurring in a posterior inferior frontal area previously associated with grapheme-to-phoneme mapping. Contrary to lexicon-based models of word recognition, there were no brain areas in which activation increased with neighborhood size. For words, activation in the left prefrontal, angular gyrus, and ventrolateral temporal areas was stronger for items without neighbors, probably because accurate responses to these items were more dependent on activation of semantic information. The results show neural correlates of access to specific word information. The absence of facilitatory lexical neighborhood effects on activation in these brain regions argues for an interpretation in terms of semantic access. Because subjects performed the same task throughout, the results are unlikely to be due to task-specific attentional, strategic, or expectancy effects.
Meat Is Good to Taboo: Dietary Proscriptions as a Product of the Interaction of Psychological Mechanisms and Social Processes
Authors: Fessler Daniel , Navarrete Carlos David
Published: April 2003

Comparing food taboos across 78 cultures, this paper demonstrates that meat, though a prized food, is also the principal target of proscriptions. Reviewing existing explanations of taboos, we find that both functionalist and symbolic approaches fail to account for meat's cross-cultural centrality and do not reflect experience-near aspects of food taboos, principal among which is disgust. Adopting an evolutionary approach to the mind, this paper presents an alternative to existing explanations of food taboos. Consistent with the attendant risk of pathogen transmission, meat has special salience as a stimulus for humans, as animal products are stronger elicitors of disgust and aversion than plant products. We identify three psychosocial processes, socially-mediated ingestive conditioning, egocentric empathy, and normative moralization, each of which likely plays a role in transforming individual disgust responses and conditioned food aversions into institutionalized food taboos.
The state of emergentism in second language acquisition
Authors: Gregg Kevin R.
Published: April 2003

‘Emergentism’ is the name that has recently been given to a general approach to cognition that stresses the interaction between organism and environment and that denies the existence of pre-determined, domain-specific faculties or capacities. Emergentism thus offers itself as an alternative to modular, ‘special nativist’ theories of the mind, such as theories of Universal Grammar (UG). In language acquisition, emergentists claim that simple learning mechanisms, of the kind attested elsewhere in cognition, are sufficient to bring about the emergence of complex language representations. In this article, I consider, and reject, several a priori arguments often raised against ‘special nativism’. I then look at some of the arguments and evidence for an emergentist account of second language acquisition (SLA), and show that emergentists have so far failed to take into account, let alone defeat, standard Poverty of the Stimulus arguments for ‘special nativism’, and have equally failed to show how language competence could ‘emerge’.
Pituitary Corticotroph Ontogeny and Regulation in Transgenic Zebrafish
Authors: Liu Ning-Ai , Huang Haigen , Yang Zhongan , Herzog Wiebke , Hammerschmidt Matthias , Lin Shuo , Melmed Shlomo
Published: April 2003

We characterized zebrafish proopiomelanocortin (POMC) gene promoter, and sequence analysis revealed that the promoter contains regulatory elements conserved among vertebrate species. To monitor the ontogeny of the pituitary POMC lineage in living vertebrates, we generated transgenic zebrafish expressing green fluorescent protein (GFP) driven by the POMC promoter. Zebrafish POMC-GFP is first expressed asymmetrically as two bilateral groups of cells most anterior to the neural ridge midline at 18–20 h post fertilization (hpf). POMC-GFP-positive cells then fuse into a single-cell mass within the pituitary anlage after 24 hpf and subsequently organize as distinct anterior and posterior domains between 48 and 64 hpf. Immunohistochemical studies with ACTH and αMSH antisera showed that POMC-GFP was mainly targeted to both anterior and posterior pituitary corticotrophs, whereas posterior pituitary region melanotrophs did not express GFP. To determine in vivo zebrafish corticotroph responses, dexamethasone (10−5m) was added to live embryos, which selectively suppressed POMC-GFP expression in the anterior group of corticotrophs, suggesting a distinct domain that is responsive to glucocorticoid feedback. Transgenic zebrafish with specific POMC-GFP expression in pituitary corticotrophs offers a powerful genetic system for in vivo study of vertebrate corticotroph lineage development.
Modelling sources and sinks of CO2, H2O and heat within a Siberian pine forest using three inverse methods
Authors: Siqueira M. , Leuning R. , Kolle O. , Kelliher F. M. , Katul G. G.
Published: April 2003

Source/sink distributions of heat, CO2 and water vapour in a Siberian Scots pine forest were estimated from measured concentration and temperature profiles using three inverse analysis methods. These methods include: a Eulerian second‐order closure model (EUL); a localized near‐field Lagrangian dispersion model (LNF); and a hybrid model (HEL) which uses the Eulerian second‐order turbulence model to calculate the flow statistics combined with the regression analysis used with the Lagrangian model. Model predictions were compared to heat flux profiles measured at five levels in the canopy, and to CO2 and water‐vapour fluxes measured close to the ground and above the forest. Predictions of sensible‐heat flux profiles by the LNF and HEL schemes were systematically better than results from the EUL analysis. This improvement was attributed to the redundancy in the measured profile (scalar concentration and temperature) data for LNF and HEL and to the imposed smoothness condition used in the regression analyses, whereas the EUL approach calculates a source for each level without any redundancy. The LNF and HEL schemes were also better than EUL in predicting source distributions for CO2 and water vapour, although errors were larger than for sensible heat. The main novelty in our study is the use of EUL to decompose the vertical variability in scalar (or heat) sources into variability produced by the inhomogeneity in flow statistics and variability inferred from the measured mean scalar concentration (or temperature) profile. Hence, it is possible with this analysis to assess how much ‘new information’ about the source variability is attributed to vertical variation in the measured mean scalar concentration (or temperature) profiles. The analysis shows that measured water vapour concentration profiles provide little information on the inferred source distribution, whereas the CO2 profiles contain more information. Monte Carlo simulations show that computed sources from all three inverse methods have similar sensitivities to errors in measured temperatures. Errors are reduced when the reference temperature above the canopy is held fixed, implying that errors in this temperature propagate throughout the entire domain. When information content and error estimations are combined, a valuable tool to assess the quality of source prediction by inverse methods can be generated. Copyright © 2003 Royal Meteorological Society
Geographical variations in the prevalence of HIV and other sexually transmitted infections in rural Tanzania
Authors: Jansen Henrica A F M , Morison Linda , Mosha Frank , Changalucha John , Todd James , Obasi Angela , Rusizoka Mary , Mayaud Philippe , Munguti Katua , Mabey David , Grosskurth Heiner , Hayes Richard
Published: April 2003

The prevalence and incidence of HIV and other sexually transmitted infections (STIs) were recorded in two lake-island and eight rural mainland communities in Mwanza, Tanzania. The prevalence and incidence of HIV and syphilis were lower on the islands, but this pattern was not seen for herpes simplex virus type-2, gonorrhoea, chlamydia, male urethritis or antenatal prevalences of Trichomonas vaginalis. Island men reported fewer sexual partners than mainland men but no differences were found for women. Island men were more likely to be circumcised, island women less mobile and there were differences in marriage patterns. Possible explanations for the differences in HIV and syphilis include: slower introduction of HIV into the islands because of geographical isolation, more core-group sexual contact on the mainland, higher prevalence of male circumcision on the islands and differences in marital status. Differences in transmission dynamics may lead to geographical patterns that vary between STIs.
Internet sex-seeking leads to acute HIV infection: a report of two cases
Authors: Tashima K T , Alt E N , Harwell J I , Fiebich-Perez D K , Flanigan T P
Published: April 2003

The use of the internet provides a rapid medium for identifying potential sexual partners and arranging in-person meetings that often result in sex. There is growing concern that the internet facilitates the transmission of sexually transmitted diseases and HIV. We report the first two cases of acute HIV infection after internet chat room encounters. Physicians should address the potential risks to sex seekers who use the internet. HIV prevention efforts that target internet sex seekers are needed.
Carbimazole-Related Gastroschisis
Authors: Guignon Anne-Maëlle , Mallaret Michel P , Jouk Pierre Simon
Published: April 2003

OBJECTIVE:

To report a case of gastroschisis in a newborn secondary to carbimazole exposure in utero.

CASE SUMMARY:

A 25-year-old white woman was treated for Graves disease with carbimazole throughout pregnancy. A boy was born prematurely by vaginal delivery, with a gastroschisis without associated malformative syndrome. Death occurred in the 25th hour of life after surgical repair.

DISCUSSION:

Carbimazole is completely metabolized to methimazole after absorption. Carbimazole or methimazole intake during pregnancy has been associated with an increased incidence of scalp aplasia. Abdominal wall defects secondary to carbimazole or methimazole exposure in utero seem to be a rare occurrence. However, other cases of abdominal wall defects have been reported in 4 newborns, 2 of them associated with scalp aplasia. An objective causality assessment revealed that the relationship between the gastroschisis and the exposure to carbimazole in utero was possible.

CONCLUSIONS:

It is important to emphasize the possible risk of abdominal wall defects in newborns to pregnant women taking carbimazole or methimazole.
Triangular Nanoplates of Silver: Synthesis, Characterization, and Use as Sacrificial Templates For Generating Triangular Nanorings of Gold
Authors: Sun Y. , Xia Y.
Published: April 2003

Triangular nanoplates of silver are prepared by irradiating aqueous dispersions of spherical silver colloids with visible light in the presence of both poly(vinyl pyrrolidone) and sodium citrate. These silver nanoplates serve as sacrificial templates to generate triangular rings of gold (see transmission electron microscopy images in Figure) through a galvanic displacement reaction between silver and aqueous HAuCl4 solutions.
Preparation and properties of waterborne polyurethanes for water‐vapor‐permeable coating materials
Authors: Kwak Yong‐Sil , Park Sang‐Woo , Lee Young‐Hee , Kim Han‐Do
Published: April 2003

Waterborne polyurethanes were prepared by polyaddition reaction using isophorone diisocyanate, dimethylol propionic acid, various polyols with a fixed molecular weight (Mn = about 2000), ethylene diamine as a chain extender, and triethylamine as a neutralization agent. Three types of polyols such as (1) solo glycols [polypropylene glycol (PPG) (Mn = 2000), poly(tetramethylene oxide) glycol (PTMG) (Mn = 2000), poly(tetramethylene adipate glycol) (PTAd) (Mn = 2000), or polycaprolactone glycol (PCL) (Mn = 2000)], (2) the polyol blends (PPG/PCL, PTMG/PCL, PPG/PTAd, PTMG/PTAd), and (3) a triblock glycol (TBG) (Mn = 1990) were used in this study. The triblock glycol (TBG) [(CL)4.5–PTMG (Mn = 1000)–(CL)4.5 (Mn =1990] was synthesized from PTMG and ϵ‐caprolactone (CL) in this study. The triblock glycol was found to have two main melting peaks at about 13 and 40°C. This study was examined on the effect of the types of polyols on the particle size, viscosity, dynamic thermal properties, and water vapor permeability. The particle size of the aqueous polyurethane–urea dispersion increased in the order of polyol‐blends‐based samples (183–350 nm) > TBG‐based sample (167 nm) > solo‐polyol‐based sample (58–96 nm). By dynamic thermal mechanical analysis, the ester‐type polyol‐ (PTAd and PCL) based samples were found to have higher storage modulus and Tg than those of ether‐type polyol‐ (PPG and PTMG) based samples. The water vapor permeability (WVP) increased in the order of TGB‐based sample > PCL/PTMG‐based sample > PTAd/PTMG‐based sample > PCL/PPG‐based sample > PTAd/PPG‐based sample > PTMG‐based sample > PPG‐based sample > PCL‐based sample > PTAd‐based sample. WVP was found to increase in the order of TBG‐based sample > polyol‐blend based samples > solo‐polyol‐based samples. It was also found that the samples containing ether‐type glycols (PTMG, PPG) had higher permeability than samples having ester‐type glycols (PCL, PTAd). PTMG‐based samples were found to have higher permeability than PPG‐based samples if other compositions were constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 123–129, 2003
Pressure and cooling rate‐induced densification of atactic polystyrene
Authors: Pantani Roberto
Published: April 2003

The exact knowledge of postprocessing polymer‐specific volume is often a factor of enormous strategic importance from an industrial point of view. The subject is complicated by the fact that the specific volume of solid polymers at a constant temperature and pressure is not only a function of the current temperature and pressure, but is also a consequence of the whole formation history from the melt. In this work, specific volumes of samples solidified in different conditions are analyzed and related to their formation history. A wide range of cooling rates (from 5 × 10−3 to 300 K/s) and solidification pressures (from 0.1 to 80 MPa) are examined. The results show a synergic effect of the cooling rate and solidification pressure: Lower cooling rates result in a much higher pressure‐induced densification with respect to higher cooling rates. A simple phenomenological model which essentially links the densification effect to the dependence of the glass transition temperature upon the cooling rate and solidification pressure is adopted to describe the experimental data. Starting from the densification effect, the effect of the pressure and cooling rate on the glass transition temperature is evaluated. Furthermore, some conclusions about the dependence of the volume relaxation time on the temperature and pressure in the glass transition range are achieved. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 184–190, 2003
Borrelien: zeitgerechter Wirtswechsel
Authors: Erdnüß Frank
Published: April 2003

Borrelien exprimieren bestimmte Oberflächenproteine, die zum Übertritt von der Zecke in den Warmblüter notwendig sind. Die Proteinsynthese erfolgt zeitgerecht, je nachdem, welche Zeckenart als Zwischenwirt genutzt wird. Die Erkenntnisse können die Entwicklung eines Borreliose‐Impfstoffes beeinflussen.
Molekulargenetik im Artenschutz: Schutz der Europäischen Sumpfschildkröte
Authors: Poschadel Jens R. , Parzefall Jakob
Published: April 2003

Eine neue entwickelte Feldmethode macht die DNA‐Extraktion aus der Mundschleimhaut geschützter Vertebraten im Freiland sowie im Labor möglich. Die Methode fand bei der Probenahme zur Ermittlung der genetischen Variabilität in drei ausgewählten europäischen Gebieten mit insgesamt 13 Populationen der Europäischen Sumpfschildkröte Emys orbicularis Verwendung. Die Analyse der gewonnenen Proben ergab einen Gradienten in der Variabilität des gewählten genetischen Markers von der hoch diversen Region des Doñana Nationalparks im Südwesten von Spanien über die deutlich weniger diversen Populationen Ostpolens bis hin zur Inzuchtsituation bei brandenburgischen Reliktpopulationen.
Ectopic corticospinal tract and corticothalamic tract neurons in the cerebral cortex of yotari and reeler mice
Authors: Yamamoto Tatsuro , Sakakibara Shunsuke , Mikoshiba Katsuhiko , Terashima Toshio
Published: April 2003

Reeler and yotari mice, which are mutant for Reelin or Dab1, respectively, show disorders of cerebral cortical lamination. We injected horseradish peroxidase (HRP) into the upper lumbar enlargement to label corticospinal tract (CST) neurons and wheat germ agglutinin‐conjugated HRP (WGA‐HRP) into the ventral lateral nucleus of the thalamus to label corticothalamic tract (CTT) neurons in both 19‐day‐old yotari and reeler mice with the aim of discovering whether or not they show differences in the distribution pattern of layer V or layer VI neurons. Similar injections of tracers were made in normal controls. HRP‐labeled CST neurons, which were exclusively distributed in layer V of the normal cortex, were radially scattered in the cortex of both mutants, but those in reeler were more deeply distributed than in yotari. WGA‐labeled CTT neurons, which were mainly located in layer VI in the normal cortex, were superficially distributed just beneath the pia mater in both reeler and yotari cortex. The present quantitative study shows that the distribution pattern of layer V neurons, but not layer VI neurons, differs between reeler and yotari mice, suggesting that the Reelin and Dab1 proteins may play different roles in the migration and cell positioning of layer V neurons. J. Comp. Neurol. 461:61–75, 2003. © 2003 Wiley‐Liss, Inc.
Factors predictive of survival for esophageal carcinoma treated with preoperative radiotherapy with or without chemotherapy followed by surgery
Authors: Yeh Alexander M. , Mendenhall William M. , Morris Christopher G. , Zlotecki Robert A. , Desnoyers Rodwige J. , Vogel Stephen B.
Published: April 2003

Purpose

To evaluate parameters that may influence prognosis in patients treated with preoperative radiotherapy (RT) or chemoradiation.

Methods and Materials

One hundred seventy‐six patients with esophageal carcinoma received preoperative radiotherapy (45 patients) or chemoradiation (131 patients). Forty‐three received no surgery (NS), 32 had exploratory surgery (ES), and 101 received definitive surgery (DS).

Results

Five‐year cause‐specific survival and absolute survival rates were overall, 19% and 16%; NS group, 0% and 0%; ES group, 3% and 3%; DS group, 30% and 26%. On univariate analysis, definitive surgery (P < 0.0001), tumor size less than 5 cm (P < 0.0001), and chemotherapy (P = 0.0015) were significant predictors of improved cause‐specific survival. Cause‐specific survival was 51% for tumors ≤3 cm (n = 33), 32% for 3.1 to 4 cm (n = 28), and 16% for 4.1 to 5 cm (n = 29). No patient with a tumor ≥6 cm (n = 86) survived. Multivariate analysis of the DS group showed complete or partial pathologic response (P = 0.0001), chemotherapy (P = 0.0026), and overall treatment time less than 3 months (P = 0.0405) significantly predicted improved cause‐specific survival. Tumor <5 cm was marginally significant (P = 0.0515).

Conclusion

Patients who undergo preoperative chemoradiation and definitive surgery have improved survival. J. Surg. Oncol. 2003;83:14–23. © 2003 Wiley‐Liss, Inc.
Aphrodisiac activity of methanol extract of leaves of Passiflora incarnata Linn. in mice
Authors: Dhawan Kamaldeep , Kumar Suresh , Sharma Anupam
Published: April 2003

The aphrodisiac properties of the methanol extract of leaves of Passiflora incarnata Linn. have been evaluated in mice by observing the mounting behaviour. The methanol extract of P. incarnata exhibited significant aphrodisiac behaviour in male mice at all doses, i.e. 75, 100 and 150 mg/kg. Amongst these, the highest activity was observed with the 100 mg/kg dose when the mountings were calculated about 95 min after the administration of the test extracts. Copyright © 2003 John Wiley & Sons, Ltd.
Antibacterial, antiprotozoal and antioxidant activity of five plants used in Izabal for infectious diseases
Authors: Navarro M. C. , Montilla M. P. , Cabo M. M. , Galisteo M. , Cáceres A. , Morales C. , Berger I.
Published: April 2003

Methanol and aqueous extracts from ﬁve plant species, used in traditional medicine in Guatemala for the treatment of microbial infections, were tested in vitro for their ability to scavenge DPPH, OH· and O2‐ radicals and to inhibit lipoperoxidation (LPO) in order to establish a relationship between their antioxidant activities and their effects against infectious agents. Acalypha guatemalensis, Ocimum micranthum and Smilax spinosa possessed a signiﬁcant activity against both the three free radicals assayed and LPO; Guazuma ulmifolia showed effects against DPPH and OH·. Piper auritum showed no activity. These extracts were also evaluated for antibacterial and antiprotozoal activities. A. guatemalensis showed activity against Pseudomonas aeruginosa; S. spinosa was active against Salmonella typhi, and A. guatemalensis, and S. spinosa against Trypanosoma cruzi or Leishmania spp. Copyright © 2003 John Wiley & Sons, Ltd.
An SH3 domain is required for the mitogenic activity of microinjected phospholipase C‐γ1
Authors: Huang Pearl S. , Davis Lenora , Huber Hans , Goodhart Paula J. , Wegrzyn Ron E. , Oliff Allen , Heimbrook David C.
Published: April 2003

Phospholipase activity is elevated in dividing cells. In response to growth factor stimulation, phospholipase C‐γ (PLC‐γ) binds to activated tyrosine kinase receptors via SH2 binding domains, resulting in phosphorylation of PLC‐γ and activation of its enzyme activity. These observations suggest that PLC‐γ participates in the signal transduction pathway employed by growth factors to promote mitogenesis. Consistent with this hypothesis, microinjection of purified bovine PLC‐γ into quiescent fibroblasts has been previously reported to initiate a mitogenic response [Smith et al. (1989) Proc. Natl. Acad. Sci. 86, 3659]. We have reproduced this result using recombinant rat PLC‐γ protein. Surprisingly, however, a catalytically inactive mutant of PLC‐γ, H335Q, also elicited a full mitogenic response. The capacity to induce mitogenesis by microinjection of PLC‐γ was mapped to the ‘Z’ domain of the protein, which contains PLC‐γ's SH2 and SH3 motifs. Inactivation of the phosphorylated tyrosine binding properties of both SH2 domains had no effect on the mitogenic activity of the Z‐domain peptide. However, deletion of the SH3 domain resulted in a complete loss of activity. These results suggest that PLC‐γ's mitogenic properties do not require the enzyme's phospholipase activity, but are instead mediated by a novel pathway for mitogenic stimulation which is dependent upon an intact SH3 domain.
Adhalin mRNA and cDNA sequence are normal in the cardiomyopathic hamster
Authors: Roberds Steven L. , Campbell Kevin P.
Published: April 2003

Adhalin is deficient in two forms of human muscular dystrophy, one due to mutations in the adhalin gene and one linked to an unidentified gene on chromosome 13. Because adhalin is deficient in skeletal and cardiac muscles of BIO 14.6 hamsters, which experience both myopathy and cardiomyopathy, cDNA encoding adhalin from BIO 14.6 hamster skeletal muscle was cloned and sequenced. Adhalin mRNA was expressed at normal levels in BIO 14.6 hamster cardiac muscle, and no mutation in adhalin coding sequence was found, indicating that the inherited myopathy and cardiomyopathy of the BIO 14.6 hamster are most likely not due to mutations in the adhalin gene.
Isolation and characterization of the cDNA for pea chloroplast SecA Evolutionary conservation of the bacterial‐type SecA‐dependent protein transport within chloroplasts
Authors: Nohara Tetsuya , Nakai Masato , Goto Akira , Endo Toshiya
Published: April 2003

We report here the isolation of the cDNA for pea chloroplast SecA. Pea SecA encodes a polypeptide of 1,011 amino acids and shows high sequence similarity with cyanobacterial SecA. Pea SecA was synthesized as a larger precursor and was imported into isolated chloroplasts in vitro. The purified pea SecA, which was expressed in Escherichia coli cells, stimulated the in vitro import of the 33 kDa protein of the oxygen‐evolving complex into thylakoids. These results indicate that higher plant chloroplasts contain a bacterial‐type SecA protein‐dependent system for the intraorganellar protein transport into thylakoids.
Time‐resolved Fourier‐transform infrared studies of the cytochrome P‐450cam carbonmonoxide complex bound with (1R)‐camphor and (1S)‐camphor substrate
Authors: Contzen Jörg , Ristau Otto , Jung Christiane
Published: April 2003

The CO‐binding reaction of cytochrome P‐450cam bound with (1R)‐camphor and (1S)‐camphor are compared in the temperature region of 210–260 K using time‐resolved Fourier‐transform infrared spectroscopy with the CO stretch vibration as spectroscopic probe. For (1S)‐camphor as substrate the association of CO is slowed down by a factor of 2, while the dissociation is accelerated by a factor of 3. The CO complex for the (1S)‐camphor‐bound P‐450 is less stabilized (ΔG=−22 kJ/mol) compared to the natural substrate (1R)‐camphor (ΔG=−30 kJ/mol). The data are interpreted by a smaller change of the mobility of the (1S)‐camphor due to CO binding as compared to (1R)‐camphor, which would indicate a higher mobility of (1S)‐camphor already in the CO free reduced form of P‐450cam. The higher mobility of (1S)‐camphor in the heme pocket might explain the increased uncoupling rate (hydrogen peroxide formation) of 11% [Maryniak et al. (1993) Tetrahedron 49, 9373–9384] during the P‐450cam catalyzed hydroxylation compared to 3% for the conversion of (1R)‐camphor.
The p18 component of the multisynthetase complex shares a protein motif with the β and γ subunits of eukaryotic elongation factor 1
Authors: Quevillon Sophie , Mirande Marc
Published: April 2003

In higher eukaryotes, nine aminoacyl‐tRNA synthetases form a multienzyme complex also comprising the three auxiliary proteins p18, p38 and p43, of apparent molecular masses of 18, 38 and 43 kDa. The function of these proteins, invariably found associated to the synthetase components of the complex, is unknown. In order to gain a more precise view of the structural and functional organization of this complex, we cloned the cDNA encoding the p18 component. The 174‐amino‐acid hamster protein displays sequence homology with the NH2‐terminal moieties of the β and γ subunits of the elongation factor EF‐1H, implicated in subunits interaction. The homologous polypeptide fragment of about 90 amino acids is also recovered in the NH2‐terminal extension of human valyl‐tRNA synthetase, involved in its assembly with EF‐1H. These results suggest that p18 contributes a template for association of the multisynthetase complex with EF‐1H.
Artificial peroxidase‐like hemoproteins based on antibodies constructed from a specifically designed ortho‐carboxy substituted tetraarylporphyrin hapten and exhibiting a high affinity for iron‐porphyrins
Authors: Quilez Rebeca , de Lauzon Solange , Desfosses Bernard , Mansuy Daniel , Mahy Jean-Pierre
Published: April 2003

In order to get catalytic antibodies modelling peroxidases BALB/c mice have been immunized with iron(III)α,α,α,β‐mesotetrakis‐orthocarboxyphenyl‐porphyrin (Fe(ToCPP))‐KLH conjugates. Monoclonal antibodies have been produced by the hybridoma technology. Three antibodies, 2 IgG, and 1 IgG2a, were found to bind both Fe(ToCPP) and the free base ToCPPH2 with similar binding constants. None of those antibodies was found to bind tetraphenylporphyrin. Those results suggest that the recognition of Fe(ToCPP) by the antibodies was mainly due to the binding of the carboxylate groups to some amino acid residues of the protein. True K
d values of 2.9 × 10−9 M and 5.5 × 10−9 M have been determined for the two IgG1‐Fe(ToCPP) complexes. Those values are the best ones ever reported for iron‐porphyrin‐antibody complexes. UV‐vis. studies have shown that the two IgG1‐Fe(ToCPP) complexes were highspin hexacoordinate iron(III) complexes, with no amino acid residue binding the iron, whereas the IgG2α‐Fe(ToCPP) complex was a low‐spin hexacoordinate iron(III) complex with two strong ligands binding the iron atom. Both IgG1 ‐Fe(ToCPP) complexes were found to catalyze the oxidation of 2,2′‐azinobis (3ethylbenzothiazoline‐6‐sulfonic acid (ABTS) 5‐fold more efficiently than Fe(ToCPP) alone whereas the binding of IgG2a to this iron‐porphyrin had no effect on its catalytic activity. k
cat values of 100 min−1 and 63 min−1 and k
cat/K
m. values of 105 M−1 s−1 and 119 M−1 s−1 have been found respectively for the two IgG1‐Fe(ToCPP) complexes.
Nereis sarcoplasmic Ca2+‐binding protein has a highly unstructured apo state which is switched to the native state upon binding of the first Ca2+ ion
Authors: Prêcheur Bénédicte , Cox Jos A. , Petrova Tatiana , Mispelter Joël , Craescu Constantin T.
Published: April 2003

NSCP, a sarcoplasmic Ca2+/Mg2+‐binding protein from Nereis diversicolor, shows an allosteric change during Ca2+ binding and a high positive cooperativity for Mg2+ binding. Here we report the results of CD and NMR experiments aiming to characterize the apo state and the Ca2+‐induced conformational changes in this protein. Circular dichroism spectra of the apo form are indicative of a reduced helical structure. In contrast, NMR spectra show no element of regular secondary or tertiary structure. Addition of one Ca2+ determines large spectral changes bringing the molecule in a conformation which is very close to the native three Ca 2+ state. Addition of the second and third Ca 2+ shifts this equilibrium progressively towards the liganded conformation but affects only minimally the spectrum of the liganded species.
Oligomerization of sarcoplasmic reticulum Ca2+‐ATPase from rabbit skeletal muscle
Authors: Maguire Patricia B. , Ohlendieck Kay
Published: April 2003

Although the primary structure and catalytic cycle of the sarcoplasmic reticulum Ca2+‐ATPase has been revealed, it is not well understood whether functional Ca2+ pump proteins exist in a monomeric or an otigomeric state in native skeletal muscle membranes. Here, we show that the Ca2+‐ATPase tends to form high molecular weight complexes, estimated to be dimers and tetramers using immunoblotting of two‐dimensionally separated microsomal membranes following crosslinking. This agrees with both electron microscopical and biochemical findings which demonstrate that Ca2+‐ATPase clusters are the predominant molecular species in native membranes and that oligomerization may play a role in cooperative kinetics and enzyme stabilization.
Applying survival analysis to operations management: Analyzing the differences in donor classes in the blood donation process
Authors: Melnyk Steven A. , Pagell Mark , Jorae Gail , Sharpe A.Spencer
Published: April 2003

Much of the research in operations management deals with the study of events. These events take many different forms: the length of time until a job is completed, the time interval until a component breaks down or the time taken for the development and introduction of a new product. When studying events, we are often interested in examining how factors such as the introduction of a new dispatching rule or a change in the level of capacity utilization affect the resulting events (e.g., completion time for a job). Analyzing events is not an easy task. Events are often time‐varying (where the probability of the event taking place changes over the life of the event), seldom normally distributed (with the distributions often being highly skewed) and affected by censoring (observations lacking a beginning or ending point). Finally, information about events is frequently collected longitudinally. These traits create problems for the application of such commonly used procedures as ANOVA. To cope with such problems, new statistical tools are needed. This paper introduces such a statistical procedure, survival analysis. Survival analysis is a set of statistical techniques (non‐parametric, semi‐parametric and parametric) used to determine quantitatively the impact of independent variables on a dependent variable which represents the time interval between events. The usefulness of this procedure is illustrated by applying it to data taken from a study focusing on the blood donation process. The paper concludes by pointing out some of the problems encountered in operations management which can be readily analyzed using this procedure. Overall, the paper tries to make the reader aware of the capabilities offered by survival analysis.
Localization of keratin in the notochord and in notochord derived tumors—immunohistological study of rat embryo and human chordoma
Authors: Raju Trichur , Adelman Lester S. , Dahl Doris , Bignami Amico
Published: April 2003

Presence of keratin was observed in the notochordal plate of 10‐day rat embryos. The characteristic changes in the appearance of the notochord during the following days of gestation were also observed in sections stained by immunofluorescence with keratin antisera. On day 12, the keratin‐positive notochordal plate had become a cylindrical structure closely apposed to the ventral surface of the spinal cord. The distance between notochord and spinal cord progressively increased at later stages. The expression of keratin was also studied by the Avidin‐Biotin complex method on 4 chordomas, tumors originating from intraosseous notochordal vestigial remnants. In accordance with the developmental study all chordomas were keratin‐positive.
Axonal transport of gangliosides in the visual system of the developing chick embryo
Authors: Panzetta P. , Chiarenza A.P. , Maccioni H.J.F.
Published: April 2003

Chick embryos aged 7–18 days of development were injected with N‐[3H]acetylmannosamine into one eye. The labeling of gangliosides was significantly higher in the contralateral‐ than in the ipsilateral‐optic tectum in embryos aged 14 days or older. Comparison of the radioactivities of thin‐layer chromatograms of gangliosides from the contralateral‐ and ipsilateral‐optic tecta showed that in the 14‐day‐old embryo about 56 and 29% of the transported radioactivity chromatographed as GD1a and GT1, respectively. Most of the remaining radioactivity chromatographed in the zone of less complex gangliosides (GM2‐GD3, 3%; GM3, 6%). In the 18‐day‐old embryo about 72% of the transported radioactivity chromatographed as GD1a; the radioactivity in the zone of GT1 was reduced to about 2% and that in the less complex gangliosides remained low (about 14% in the zone of GM2‐GD3 and 7% in the zone of GM3).
Synthesis of plasma proteins by rat fetal brain and choroid plexus
Authors: Dziegielewska K.M. , Evans C.A.N. , New H. , Reynolds M.L. , Saunders N.R.
Published: April 2003

Several plasma proteins have previously been demonstrated to be within cells (presumed neurons) in the developing brain of various species. The possibility that the plasma proteins α‐fetoprotein (AFP) albumin and transferrin may be synthesized by developing brain and choroid plexus has been investigated in fetal rats of 18 to 22 days gestation. Samples of these tissues and of liver were incubated in Krebs solution containing [3H]leucine at 37°C for 1 h. Radioactively labelled AFP, albumin and transferrin were extracted and separated by immunoprecipitation. Incorporation of [3H]leucine into the plasma proteins was demonstrated in both fetal brain and choroid plexus. Incorporation was completely blocked by cycloheximide. It is concluded that fetal brain and choroid plexus synthesize AFP, albumin and transferrin and that secretion of these proteins by developing brain and choroid plexus cells probably contributes to the high concentration of plasma proteins in fetal csf.
Effects of triiodothyronine (T3) on the development of rat cerebellar cells in culture
Authors: Messer Anne , Maskin Paul , Snodgrass Gary L.
Published: April 2003

To determine whether or not the effects of thyroxine on the cells of the external granular layer of rat cerebellum are direct or indirect, Purkinje cell‐free dissociated cell cultures from 5‐day‐old rat cerebellum in serum‐free medium were treated with triiodothyronine (T3) at concentrations of 20–3000 ng/ml. Cultures were assayed for uptake and synthesis of γ‐aminobutyric acid (GABA) after 3 weeks, and for thymidine incorporation at 1, 2, 3 and 4 days. Specific (per mg protein) activity of glutamic acid decarboxylase and of GABA uptake into neurons was reduced by the more physiologic (50 or 500 ng/ml) concentrations of T3, probably due to a non‐neuronal increase in overall protein synthesis, since the total per culture values seem unaffected by hormone. Thymidine uptake was significantly increased only at the highest (unphysiologic) concentration of T3 on the second day after treatment. None of the label appeared to be in the nuclei of the neuronal cells at any of the times and concentrations tested.

These results are consistent with the hypothesis that T3 does not have a direct effect on the proliferation of neurons derived from the external granular layer, although it does seem to affect some non‐neuronal cells. T3 also does not seem to enhance differentiated GABA functions (uptake or synthesis) beyond the levels achieved using insulin, progesterone, putrescine, selenium and transferrin.
Receptor‐mediated uptake of labeled transferrin by embryonic chicken dorsal root ganglion neurons in culture
Authors: Markelonis G.J. , Oh T.H. , Park L.P. , Azari P. , Max S.R.
Published: April 2003

Transferrin is a growth‐promoting plasma protein which is known to occur within developing neurons. Since little information exists on the process by which transferrin is internalized by neurons, we studied this process using dissociated embryonic chicken dorsal root ganglion neurons in culture. Cultured dorsal root ganglion neurons were incubated in the presence of 3.75 nM 125I‐transferrin at 37°C, the cultures were extensively washed, the neurons were solubilized in a Triton‐containing buffer and internalized 125I‐transferrin was quantified with a gamma counter. 125I‐transferrin was internalized in a linear fashion for at least 60 min, and this uptake was abolished by the presence of 1.25 μM unlabeled transferrin. No competition for the uptake of 125I‐transferrin was observed in the presence of 1.25 μM ovalbumin, cytochrome c, hemoglobin, insulin, horseradish peroxidase, aldolase or the carboxyl‐terminal fragment (‘half‐site’) of transferrin. By contrast, uptake was inhibited by approximately 50% in the presence of the amino‐terminal fragment (‘half‐site’) of transferrin (1.25 μM) or in the presence of concanavalin A (1.25 μM). The binding of transferrin conjugated to fluorescein isothiocyanate to neurons at 4°C and its subsequent internalization at 37°C was demonstrated by fluorescence microscopy of unfixed cells following incubation of the neurons in the presence of the fluorescently labeled protein. Furthermore, the transferrin receptors were visualized immunocytochemically on the surface membranes of dorsal root ganglion neurons using rabbit antibodies directed against transferrin receptors from chicken reticulocytes. From these data, we conclude that transferrin is internalized by neurons via receptor‐mediated endocytosis, and suggest that this protein may serve an important role in the development and survival of dorsal root ganglion neurons.
Serotoninergic receptors in the visual system of light‐deprived rats
Authors: Aurich Marina , Schliebs Reinhard , Bigl Volker
Published: April 2003

The level of binding of [3H]serotonin (5‐hydroxytryptamine) to serotonin type 1 receptors (S1) in the visual centres and frontal cortex of control, dark reared and monocularly deprived (one eyelid sutured on postnatal day 10) 3‐month‐old rats were determined and compared to that assayed in 25‐day‐old rats. The two forms of light deprivation affect [3H]serotonin binding in the central visual structures in a different way.

Monocular deprivation until the age of 3 months resulted in decreased serotonin binding levels in the retina of both eyes compared to the control group raised under a 12 h light‐dark cycle. Additionally, serotonin binding in the lateral geniculate nucleus contralateral to the closed eye is decreased. Rearing rats in complete darkness from birth to the age of 3 months leads to an increase of serotonin binding in the visual cortex and superior colliculus. Regarding the normal distribution of serotonin type 1 binding sites in the visual system of 3‐month‐old rats, highest serotonin binding is found in the lateral geniculate nucleus followed by the retina, superior colliculus and visual cortex.

The differential effect of monocular or total light deprivation upon serotonin type 1 receptors in the different visual nuclei might reflect differences in the morpho‐functional organization of the serotoninergic system along the visual pathway and its involvement in visual information processing.