bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maternal sex and mate relatedness affect offspring quality in the gynodioeciousSilene acaulis
Authors: Keller S. R. , Schwaegerle K. E. 
Published: March 2006

AbstractIn gynodioecious species, females sacrifice fitness by not producing pollen, and hence must have a fitness advantage over hermaphrodites. Because females are obligately outcrossed, they may derive a fitness advantage by avoiding selfing and inbreeding depression. However, both sexes are capable of biparental inbreeding, and there are currently few estimates of the independent effects of maternal sex and multiple levels of inbreeding on female advantage. To test these hypotheses, females and hermaphrodites from six Alaskan populations of Silene acaulis were crossed with pollen from self (hermaphrodites only), a sibling, a random plant within the same population, and a plant from a different population. Germination, survivorship and early growth revealed inbreeding depression for selfs and higher germination but reduced growth in sib-crosses, relative to outcrosses. Independent of mate relatedness, females germinated more seeds that grew faster than offspring from hermaphrodites. This indicates that inbreeding depression as well as maternal sex can influence breeding system evolution. The effect of maternal sex may be explained by higher performance of female genotypes and a greater abundance of female genotypes among the offspring of female mothers.
Flight of Sharovipteryx mirabilis: the world's first delta-winged glider
Authors: Dyke G. J. , Nudds R. L. , Rayner J. M. V. 
Published: March 2006

Abstract
The 225 million-year-old reptile Sharovipteryx mirabilis was the world's first delta-winged glider; this remarkable animal had a flight surface composed entirely of a hind-limb membrane. We use standard delta-wing aerodynamics to reconstruct the flight of S. mirabilis demonstrating that wing shape could have been controlled simply by protraction of the femora at the knees, and by variation in incidence of a small forelimb canard. Our method has allowed us to address the question of how identifying realistic glide performance can be used to set limits on aerodynamic design in this small animal. Our novel interpretation of the bizarre flight mode of S. mirabilis is the first based directly on interpretation of the fossil itself and the first grounded in aerodynamics.
Matching and Symmetry in the Frequency Recognition Curve of the Poison Frog Epipedobates trivittatus
Authors: Rojas Bibiana , Amézquita Adolfo , Delgadillo Alexandra 
Published: March 2006

AbstractIn territorial species, males use signals to advertise territory ownership to other males. In species with acoustic communication, masking interference by heterospecific signals may impede male–male communication and affect the reproductive success of males. Frogs are thought to minimize masking interference by using species‐specific frequency channels for communication. For this strategy to work, a frequency match is expected between the advertisement call and the auditory sensitivity. A previous field study on the Amazonian frog Epipedobates femoralis supported this prediction, but also revealed an asymmetric decrease in the probability of male reaction towards synthetic calls. That males of E. femoralis reacted less towards low‐frequency (compared with high‐frequency) calls was interpreted as a mechanism that reduces masking interference by E. trivittatus, a species calling within a lower, partially overlapping, frequency range. If this hypothesis holds, then males of E. trivittatus should exhibit the opposite asymmetry pattern, i.e. react less towards high‐frequency (compared with low‐frequency) calls. We tested this prediction by conducting 25 playback experiments on 22 males of E. trivittatus. Male phonotactic reaction towards synthetic calls of various frequency values was evaluated as a binary variable (the male either approached or not the loudspeaker), by measuring the latency until first jump, and by calculating the linear approaching speed. As in E. femoralis, the maximum probability of positive reaction was matched to the call frequency. Against our expectations, the response curve was symmetric. We discuss whether these results reflect a lack of selective pressures, or a compromise between natural selection and physiological constraints on the shape of the frequency recognition curves.
Individual Odour Similarity and Discrimination in the Coruro (Spalacopus cyanus, Octodontidae)
Authors: Hagemeyer Petra , Begall Sabine 
Published: March 2006

AbstractPrevious studies of subterranean, fossorial and above‐ground rodents have demonstrated that similarities in individual odours covary with genetic similarities thus supporting the theory of odour‐genes covariance (i.e. the closer the individuals are genetically, the greater the similarities between their odours). We used the habituation‐generalization paradigm, where the subject is exposed to the same odour stimulus in three consecutive habituation trials followed by two test trials in which the odour from two other individuals are presented successively. Using this test design, we showed that the socially living coruros (Spalacopus cyanus) discriminate individuals on the basis of their ano‐genital odours and also respond to odour similarities between individuals. Male and female subjects treated ano‐genital odours of two same‐sex family members and also the odours of two sibling strangers as different to each other. At the same time, they treated the odours of siblings as similar compared with the odour of an unrelated individual. No gender differences were detected. Our results contrast with those from other rodent species that did not spontaneously discriminate between individual odours of siblings from a different family than their own. The polygyneous lifestyle may provide the selective background for that difference. Additional research will be necessary to explore this hypothesis and to rule out differences due to dietary preferences and due to the type of paradigm chosen for the tests.
Pedicularis and Castilleja are natural hosts of Cronartium ribicola in North America: a first report
Authors: McDonald G. I. , Richardson B. A. , Zambino P. J. , Klopfenstein N. B. , Kim M.‐S. 
Published: March 2006

SummaryWhite pine blister rust disease, caused by the introduced pathogen Cronartium ribicola, has severely disrupted five‐needled pine ecosystems in North America. A 100‐year effort to manage this disease was predicated in part on the premise that the pathogen utilizes only species of Ribes (Grossulariaceae) as alternate hosts on this continent. The current study presents the first conclusive demonstration that some species in the family Orobanchaceae (Pedicularis racemosa and Castilleja miniata) are functioning as alternate hosts in a natural ecosystem of North America. This finding has implications for improving our understanding of epidemiology, pathogen adaptation and host–pathogen interactions within white pine blister rust.
Studies on anastomosis groups of Rhizoctonia solani isolates causing disease in two forest nurseries in Poland
Authors: StĘpniewska‐Jarosz S. , Mańka M. , Asiegbu F. O. 
Published: March 2006

SummaryThirty‐eight isolates of Rhizoctonia spp. were isolated from Scots pine (Pinus sylvestris) seedlings with damping‐off symptoms, originating from two forest nurseries in central‐west Poland (Wronczyn and Jarocin) and from diseased seedlings grown in soil from Wronczyn nursery. Majority of these isolates (79%) had multinucleate cells and were identified as Rhizoctonia solani. The remaining isolates were recognized as binucleate Rhizoctonia spp. R. solani isolates were characterized using hyphal anastomosis and were divided into five anastomosis groups (AG). The most prevalent was AG5 (37% of isolates), followed by AG2‐1 (30%) and 27% of the isolates were identified as AG4. Groups AG1‐IB and AG2‐2 were only represented by single isolates. The virulence recorded as mortality (in percentage) was comparatively high for binucleate and multinucleate isolates of Rhizoctonia spp. Sequence analysis of the polymerase chain reaction (PCR)‐amplified internal transcribed spacer (ITS) rDNA region was used for phylogenetic analysis. The dendrogram showed that isolates were distinctly separated based on their AG types and there was no relationship between pathogenicity on Scots pine seedlings and the AG to which the isolates belong to. The results are discussed with respect to pathogenic potential of the various AG groups.
EFFECTS OF EXERCISE‐INDUCED ARTERIAL HYPOXAEMIA ON LIMB MUSCLE FATIGUE AND PERFORMANCE
Authors: Romer Lee M , Dempsey Jerome A 
Published: March 2006

SUMMARY

Reductions in arterial O2 saturation (−5% to −10%Sao2 below rest) occur over time during sustained heavy‐intensity exercise in a normoxic environment, caused primarily by the effects of acid pH and increased temperature on the position of the HbO2 dissociation curve.
We prevented the desaturation incurred during exercise at ∼90% O2 MAX via increased fraction of inspired O2 (Fio2) (0.23 to 0.29) and showed that exercise time to exhaustion was increased.
We used supramaximal magnetic stimulation (1–100 Hz) of the femoral nerve to test for quadriceps fatigue. We used mildly hyperoxic inspirates (Fio2 0.23 to 0.29) to prevent O2 desaturation. We then compared the amount of quadriceps fatigue incurred following cycling exercise at Sao2 91% vs 98% with each trial carried out at identical work rates and for equal durations.
Preventing the normal exercise‐induced O2 desaturation prevented about one‐half the amount of exercise‐induced quadriceps fatigue; plasma lactate and effort perception were also reduced. In a subset of less fit subjects who showed only minimal arterial hypoxaemia during sustained exercise (Sao2∼95%), breathing a mildly hypoxic inspirate (Fio2 0.17; Sao2∼88%) exacerbated the quadriceps fatigue.
We conclude that the normal exercise‐induced O2 desaturation during heavy‐intensity endurance exercise contributes significantly to exercise performance limitation in part because of its effect on locomotor muscle fatigue.
PATIENT AGE IS A STRONG INDEPENDENT PREDICTOR OF 13C‐AMINOPYRINE BREATH TEST RESULTS: A COMPARATIVE STUDY WITH HISTOLOGY, DUPLEX‐DOPPLER AND A LABORATORY INDEX IN PATIENTS WITH CHRONIC HEPATITIS C VIRUS INFECTION
Authors: Schneider Arne RJ , Teuber Gerlinde , Paul Katrin , Nikodem Alice , Duesterhoeft Matthias , Caspary Wolfgang F , Stein Juergen 
Published: March 2006

SUMMARY

Noninvasive tests for the staging of chronic hepatitis C virus (HCV) infection would be an attractive alternative to liver biopsy. The 13C‐aminopyrine breath test (ABT) has been proposed for the noninvasive assessment of hepatic function and partly correlates with fibrosis. We aimed to investigate causes for the lack of discriminatory power for different degrees of hepatic fibrosis.
Eighty‐three patients (median age 49 years (28–78 years)) with chronic HCV infection underwent the ABT after an oral load of 75 mg N,N‐dimethyl‐13C‐aminopyrine. Portal vein flow was assessed by duplex‐Doppler and a laboratory index (aspartate aminotransferase to platelet ratio index or APRI) was calculated. Parameters were compared with liver histology.
The cumulative 13C‐recovery differed significantly between patients without relevant fibrosis (fibrosis score 0–2) and cirrhosis (5–6), beginning after 30 min of sampling (P < 0.05). The ABT did not discriminate patients with fibrosis scores 3–4 from the remaining two patient groups. Sensitivity and specificity for the prediction of cirrhosis was 73.4–82.8% and 63.2–68.4%, depending on the sampling time. Compared with the fibrosis score (P = 0.04), patient age was a highly significant independent predictor for the 13C‐recovery (P < 0.0001). Aspartate aminotransferase to platelet ratio index and duplex‐Doppler predicted cirrhosis with 76.6%vs. 87.5% sensitivity and 63.2%vs. 68.4% specificity.
Our data suggest an age‐dependent decrease of cytochrome P450 activity which probably accounts for the large overlap of ABT results that preclude clear differentiation. This is also consistent with former pharmacodynamic trials. Age‐adapted reference ranges could improve ABT results.
DIRECT EFFECTS OF QUERCETIN ON IMPAIRED REACTIVITY OF SPONTANEOUSLY HYPERTENSIVE RAT AORTAE: COMPARATIVE STUDY WITH ASCORBIC ACID
Authors: Ajay Machha , Achike Francis I , Mustafa Ali Mohd , Mustafa Mohd Rais 
Published: March 2006

SUMMARY

There is a growing interest in the anti‐oxidant characteristics and use of flavonoids in the management of cardiovascular diseases. The cardiovascular mechanism of action of these plant derivatives remains controversial. This study compared the effects of the flavonoid quercetin with those of the anti‐oxidant vitamin ascorbic acid (vitamin C) on the reactivity of aortic rings from spontaneously hypertensive rats (SHR).
The phenylephrine (PE)‐induced contractile and the endothelium‐dependent and independent relaxant responses of aortic rings from 21 to 22 week old SHR and age‐matched normotensive Wistar (WKY) rats were observed in the presence of quercetin or ascorbic acid. All the experiments were performed in the presence of the cyclooxygenase inhibitor, indomethacin (10 mmol/L).
The endothelium‐dependent and independent relaxations to acetylcholine (ACh) and sodium nitroprusside (SNP), respectively, were significantly lesser in the SHR compared to the WKY tissues whereas the contractile responses to PE were similar in both tissues. Pretreatment of WKY rings with quercetin or ascorbic acid had no effect on the responses to ACh or PE. In the SHR tissues, however, quercetin or ascorbic acid significantly improved the relaxation responses to ACh and reduced the contractions to PE with greater potency for quercetin. Both compounds lacked any effects on the responses to SNP in either aortic ring types. Nw‐nitro‐L‐arginine methyl ester (l‐NAME, 10 mmol/L) significantly attenuated the vasodepressor effects of quercetin and ascorbic acid, raising the responses to PE to a level similar to that observed in the control SHR tissues. In l‐NAME pretreated aortic rings, quercetin and ascorbic acid inhibited the contractile responses to PE with the same magnitude in WKY and SHR tissues.
The present results suggest that acute exposure to quercetin improves endothelium‐dependent relaxation and reduces the contractile responses of hypertensive aortae with a greater potency than ascorbic acid. This suggests a better vascular protection with this flavonoid than ascorbic acid in the SHR model of hypertension and possibly in human cardiovascular diseases.
THERAPEUTIC EFFECT OF GREEN TEA EXTRACT ON ADVANCED GLYCATION AND CROSS‐LINKING OF COLLAGEN IN THE AORTA OF STREPTOZOTOCIN DIABETIC RATS
Authors: Babu Pon Velayutham Anandh , Sabitha Kuruvimalai Ekambaram , Shyamaladevi Chennam Srinivasulu 
Published: March 2006

SUMMARY

The therapeutic effect of green tea extract (GTE) on the aortic collagen content and its characteristics were investigated in streptozotocin diabetic rats.
Diabetes was induced in rats by a single intra peritoneal injection of streptozotocin (60 mg/kg bodyweight). Six weeks after diabetes induction, GTE was administered orally for four weeks (300 mg/kg bodyweight daily). Systolic blood pressure, blood glucose, anti‐oxidant status, collagen content, extent of glycation, collagen linked fluorescence and aortic collagen solubility pattern were determined in experimental rats.
At the end of the experimental period, there was a significant increase in the systolic blood pressure and blood glucose in diabetic rats. The lipid peroxides increased whereas glutathione and vitamin C levels were decreased in the serum of diabetic rats. The collagen content, extent of glycation, the advanced glycation end products (AGEs) and degree of cross‐linking were increased in the aorta of diabetic rats.
The oral administration of GTE to diabetic rats significantly reduced the systolic blood pressure and blood glucose. The level of lipid peroxides reduced and the content of glutathione and vitamin C increased in the serum of GTE treated diabetic rats. Green tea extract also impede the accumulation of aortic collagen, extent of glycation, formation of AGEs and cross‐linking of collagen in diabetic rats. The antihyperglycemic, anti‐oxidant and antiglycating effects of GTE ascribed for these beneficial effects. In conclusion, green tea may have therapeutic effect in the treatment of cardiovascular complications characterized by increased AGE accumulation and protein cross‐linking associated with diabetes.
ATORVASTATIN PREVENTED AND PARTIALLY REVERSED ADRENOCORTICOTROPIC HORMONE‐INDUCED HYPERTENSION IN THE RAT
Authors: Mondo Charles K , Yang Wan‐Song , Su Ji‐Zhou , Huang Ti‐Gang 
Published: March 2006

SUMMARY

Adrenocorticotropic hormone (ACTH)‐induced hypertension is associated with nitric oxide (NO) deficiency and increased oxidative stress. Atorvastatin (Ato), an HMG‐Co‐enzyme‐A reductase inhibitor has been reported to enhance availability of NO. The aim of the study was to assess whether pretreatment with Ato would prevent the development of ACTH‐induced hypertension and whether established ACTH‐induced hypertension could be reversed with subsequent administration of Ato in rats.
Male Sprague‐Dawley rats (n = 60) were treated with Ato (30 mg/kg per day in drinking water) or tap water for 15 days. ACTH (0.2 mg/kg per day s.c) or saline was started 4 days after Ato treatment or non‐treated rats and continued for 11–13 days (prevention study). In the reversal study, Ato was given on day 8 of ACTH/Saline treatment for 5 days. Systolic blood pressure (SBP) was measured on alternate days using the tail cuff method.
Adrenocorticotropic hormone treatment increased SBP (110 ± 2–136 ± 2 mmHg, P < 0.001) and aortic superoxide production (P < 0.001). Ato alone did not alter SBP, but Ato pretreatment prevented ACTH‐induced hypertension compared with that in rats treated with ACTH alone (118 ± 2 and 136 ± 2 mmHg, respectively, P¢ < 0.01). Ato partially reversed ACTH‐induced hypertension (124 ± 3 and 136 ± 2 mmHg, respectively, P¢ < 0.05). Plasma nitrate/nitrite (NOx) was decreased in ACTH‐treated rats compared with saline treated rats (6.6 ± 0.4 saline and 4.5 ± 0.5 mmol/L ACTH, P < 0.001). Atorvastatin affected neither plasma NOx nor aortic superoxide production.
Atorvastatin prevented and partially reversed ACTH‐induced hypertension in the rat.
UPREGULATION OF 14‐3‐3 ISOFORMS IN ACUTE RAT MYOCARDIAL INJURIES INDUCED BY BURN AND LIPOPOLYSACCHARIDE
Authors: He Ming , Zhang Jixiang , Shao Lijian , Huang Qiren , Chen Jie , Chen Heping , Chen Xuanying , Liu Dan , Luo Zhijun 
Published: March 2006

SUMMARY

Burn‐induced myocardial injuries can be acute due to loss of body fluid and blood redistribution, and subacute due to pathogenic toxins of infecting bacteria. The goal of this study was to examine expression of 14‐3‐3 in the injured myocardium.
Myocardial injury models were created in vivo by subjecting rats to severe burn and administration of lipopolysaccharide. RT‐PCR and Western blotting were employed to assess the expression of 14‐3‐3 proteins and messenger ribonucleic acid (mRNA) for 14‐3‐3h and g in the myocardium, respectively.
In the two models, we found that 14‐3‐3 proteins were induced in a time‐dependent fashion. Such a change is at least in part attributed to increases in mRNAs for 14‐3‐3g and h. In contrast to 14‐3‐3z, whose mRNA was not detectable in the heart, mRNA for 14‐3‐3g was found significantly elevated between 24–48 h after burn. 14‐3‐3h mRNA exhibited a marked increase at 3 h continuing to 12 h and then decreased nearly to a normal level after 48 h. In lipopolysaccharide‐treated intact rats, 14‐3‐3g mRNA in myocardium showed a significant increase, reaching a peak at 4 h, followed by a decrease at 6 h. In contrast, 14‐3‐3h mRNA had a slight increase without significance.
Our results suggest that 14‐3‐3 may play a role in both acute and subacute (postburn infectious) phases of severe burn.
FLUVASTATIN INCREASES HETEROTOPICALLY INDUCED OSSICLES IN MICE
Authors: Galus R , Wlodarski PK , Wlodarski KH 
Published: March 2006

SUMMARY

The aim of the present study was to evaluate the influence of fluvastatin (3‐hydroxy‐3‐methylglutarylcoenzyme A reductase inhibitor) on heterotopic ossification (HO) induced by HeLa cells.
C57Bl/6 mice were injected with 3 ¥ 106 HeLa cells into right thigh muscles. Mice in the experimental group received fluvastatin 1.2 mg/kg per day for 17 consecutive days, while mice in the control group received placebo. Intact mice served as an additional control. Seventeen days post‐HeLa cell grafting, blood samples were collected to measure total serum cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol and alkaline phosphatase (AP).
In all animals injected with HeLa cells, the mass of mineral deposited in the induced ossicle was established after hydrolysis of soft tissues surrounding the induced ossicles. In fluvastatin‐treated mice, the mass of mineral deposited in heterotopically induced ossicles was significantly increased, when compared to mice receiving placebo. This was followed by a significant decrease of TG concentration; whereas the levels of serum AP were not significantly affected.
These results indicate that administration of statins may affect heterotopic ossification. This may also have clinical implication, because patients predisposed to HO and receiving statins during hypocholesterolemic treatment, may be at even greater risk of HO.
Dyspeptic symptoms associated with hypersensitivity to gastric distension induced by duodenal acidification
Authors: LEE KWANG JAE , KIM JIN HONG , CHO SUNG WON 
Published: March 2006

AbstractBackground and Aim:  Duodenal acidification might increase sensitivity to gastric distension, which seems to play a role in the genesis of dyspeptic symptoms in a subset of patients with functional dyspepsia. The aim of the present study was to investigate the characteristics of dyspeptic symptoms associated with hypersensitivity to gastric distension induced by duodenal acidification.Methods:  An infusion tube and a barostat bag were positioned in the duodenum and gastric fundus, respectively. Sensitivity to stepwise fundic distensions with severity scoring of the seven dyspeptic symptoms was assessed before and during duodenal acid infusion in 20 healthy subjects.Results:  Acid infusion significantly decreased the pressures and the corresponding wall tensions at the thresholds for discomfort. At the distending level of minimal distending pressure (MDP) + 2 mmHg, significantly higher scores of fullness and bloating were obtained during acid infusion. With distending stimuli of MDP + 4 and 6 mmHg, fullness, bloating, nausea, satiety, epigastric burning and epigastric pain were significantly more severe during acid infusion than before acid infusion. At the level of MDP + 8 mmHg, the severity of epigastric pain was significantly greater, compared with that before acid infusion.Conclusions:  Duodenal acidification might aggravate dyspeptic symptoms through the induction of hypersensitivity to gastric distension in healthy individuals. Those symptoms are diverse and variable, depending on the strength of the distending stimuli.
Enteroliths developed in a chronically obstructed afferent loop coexisting with gastric remnant carcinoma: Case report and review of the literature
Authors: Yavuz Nihat , Ergüney Sabri , Ögüt Gunduz , Alver Olcay 
Published: March 2006

AbstractA case of gastric remnant carcinoma coexisting with a chronic afferent loop syndrome harboring multiple enteroliths in a grossly dilated and elongated afferent loop is presented herein. The patient had undergone a Polya type antecolic Billroth II reconstruction for a stenosing duodenal ulcer 40 years previously. A concise review of the relevant literature is also presented.