bluuebunny/crossref_metadata_2025 huggingface dataset:
Nursing staff mix models and outcomes
Authors: McGillis Hall Linda
Published: October 2003

Background. Recently, restructuring of the nursing workforce has been undertaken in a number of countries in an effort to provide efficient and cost‐effective services to users. This often takes the form of the introduction of unregulated workers to carry out support roles with registered nurses. However, these changes have not been evaluated for efficacy or impact on nurses, patients or the health care system.

Purpose. The purpose of this study was to determine the relationship between staff mix models comprising regulated staff (Registered Nurses and Registered Practical Nurses) or regulated and unregulated staff (Registered Nurses and unregulated workers), and nursing and quality outcomes.

Methods. This comparative correlational study was conducted in a random sample of 30 adult, acute care patient units within eight hospitals located in Toronto, Canada. Registered Nurses employed on 30 randomly selected hospital units, grouped by the two staff mix models (15 units per group), were surveyed using previously validated instruments to measure role conflict, role ambiguity, job satisfaction, perceived effectiveness of care and perceived quality of care.

Results. Results indicated that Registered Nurses in this study experienced high levels of role conflict, regardless of the type of staff mix model within which they worked. Registered Nurses on units employing both Registered Nurses and unregulated workers reported higher levels of job satisfaction. On units employing both Registered Nurses and unregulated workers, Registered Nurses perceived that the quality of care was lower.

Conclusions. Staff mix model was related to Registered Nurses’ perceptions of the quality of patient care. It was also evident that other variables within the work environment might have more influence on the outcomes examined than the independent variable of staff mix.
Of plants and other pets: practical aspects of freeze‐substitution and resin embedding
Authors: Hess M. W.
Published: October 2003

Representative tissues from higher plants (e.g. developing pollen, somatic anther tissues from the monocotyledonous angiosperm Ledebouria) and mammalian cell cultures were successfully cryoimmobilized by means of high‐pressure freezing. Various substitution and embedding protocols were then evaluated considering the preservation of ultrastructural details, membrane staining, immunolabelling properties, as well as reproducibility and ease of use. Two types of recipe proved to be highly suitable for most applications, regardless of type, developmental stage or physiological conditions of the cells: (i) the best choice for morphology is still osmium in acetone (optionally supplemented with uranyl acetate) followed by embedding in Epon and/or Araldite; (ii) feasible approaches for immunocytochemistry are freeze‐substitution with ethanol containing uranyl acetate and formaldehyde, or with pure acetone (in the case of fixation‐sensitive antigens), followed by embedding with LR‐white acrylic resin; though being far from optimal, these combinations represent, in my opinion, an acceptable compromise between labelling intensity, section stability, structural preservation and health hazards. Notably, the patterns observed in Ledebouria were consistent with data obtained from a broad range of other specimens from all kingdoms (e.g. leaves and callus cultures from angiosperms, gymnosperm roots with their ectomycorrhizal fungi, mammalian cell cultures and eubacteria). Finally, a warning is given as to the extractive potentials of embedding resins (Spurr's mixture, LR‐white, but also Epon) being sometimes the cause of unacceptable artefacts, both in plant and in mammalian cells prepared by cryoimmobilization and freeze‐substitution.
Blockade of macrophage migration inhibitory factor (MIF) in Schistosoma japonicum‐infected mice results in an increased adult worm burden and reduced fecundity
Authors: Stavitsky Abram B. , Metz Christine , Liu Shifan , Xianli Jia , Bucala Richard
Published: October 2003

Macrophage migration inhibitory factor (MIF), a cytokine produced by many cell types, modulates cellular and humoral immune responses. In schistosomiasis, ova in the portal circulation induce a delayed type hypersensitivity (DTH) that results in formation of hepatic granulomas (HG) which secrete MIF activity. Therefore, we hypothesized that endogenous MIF modulates immune responses in schistosomiasis. To test this hypothesis, Schistosoma japonicum‐infected mice were injected with rabbit IgG or neutralizing rabbit IgG antibody to MIF 4·5–6·5 week post infection when HG form and female worms are laying eggs. Compared with controls, 6·5–7‐week post‐infection, antibody‐treated mice had 1·7–3 times as many adult worms and half as many ova per worm pair in their livers. In contrast, antibody introduced before infection or 6–8 week post infection did not affect worm burden or fecundity. Thus, for the first time there is evidence that 4·5–6 week post‐infection endogenous MIF somehow mediates reduction of adult worm burden and promotes fecundity. Splenocytes and HG cells from antibody‐treated mice showed reduced intracellular expression of TNFα and/or IL‐10. We hypothesize that endogenous MIF enhances adult worm attrition by up‐regulating innate and adaptive immune responses by increasing expression of MHC‐II, co‐stimulatory, adhesion, receptor and cytokine molecules, and promotes fecundity by up‐regulating TNFα expression.
Enlarging pigmented patches on the hand
Authors: Muellenhoff Matthew , Cukrowski Tiffany , Morgan Michael , Miller Richard
Published: October 2003

This case illustrates the clinical and pathological features of Tinea mgra. Awareness of the characteristic features of this cutaneous infection, especially in areas where the organism is endemic, can ultimately lead clinicians to the appropriate diagnosis. If Tinea nigra should be considered in the differential diagnosis of palmoplantar pigmentation, potassium hydroxide (KOH) preparation may facilitate the diagnosis.
Clinical and mycological status of the Trichophyton mentagrophytes (interdigitale) syndrome of chronic dermatophytosis of the skin and nails
Authors: Zaias Nardo , Rebell Gerbert
Published: October 2003

The syndrome of tinea pedis caused by human‐adapted Trichophyton mentagrophytes (interdigitale) can be recognized by two signs not characteristically seen in tinea pedis caused by T. rubrum and Epidermophyton floccosum:1 bullous > 2 mm vesicles in the thin skin of the plantar arch and along the sides of the feet and heel adjacent to the thick plantar stratum corneum,2 and white superficial onychomycosis. The relationship of the syndrome to zoophilic T. mentagrophytes remains in question.
Treatment of acquired syndactyly by gauze‐fixed epidermal graft after radiosurgery
Authors: Kim Seong Eon , Sun Young‐Woo , Yoon Tae‐Jin , Kim Tae‐Heung
Published: October 2003

Background  Acquired syndactyly is a rare disease that occurs mostly after disease, trauma, or other inflammatory conditions. It is usually treated by surgical incision with a flap or full‐thickness skin graft, which is very invasive and requires hospitalization.

Objective  The objective was to treat acquired syndactyly with an epidermal graft by suction blister after radiosurgery, because this procedure is much less invasive and can be performed in an outpatient base.

Methods  A 65‐year‐old Korean woman had acquired syndactyly after various traditional treatments for tinea pedis. Five days after separation of syndactyly with radiosurgery, we prepared an epidermal sheet by suction blister, placed it on sterile meshed gauze, and applied it to the separated lesion.

Results  The patient's lesion was completely healed after 7 days.

Conclusion  Gauze‐fixed epidermal graft after radiosurgery is a very effective and simple treatment for shallow acquired syndactyly.
The activation of gelsolin by low pH
Authors: Lagarrigue Emeline , Ternent Diane , Maciver Sutherland K. , Fattoum Abdellatif , Benyamin Yves , Roustan Claude
Published: October 2003

Gelsolin is a multidomain and multifunction protein that nucleates the assembly of filaments and severs them. The activation of gelsolin by calcium is a multistep process involving many calcium binding sites that act to unfold the molecule from a tight structure to a more loose form in which three actin‐binding sites become exposed. Low pH is also known to activate gelsolin, in the absence of calcium and this too results in an unfolding of the molecule. Less is known how pH‐activation occurs but we show that there are significant differences in the mechanisms that lead to activation. Crucially, while it is known that the bonds between G2 and G6 are broken by co‐operative occupancy of calcium binding sites in both domains [Lagarrique, E., Maciver, S. K., Fattoum, A., Benyamin, Y. & Roustan, C. (2003) Eur. J. Biochem. 270, 2236–2243.], pH values that activate gelsolin do not result in a weakening of the G2‐G6 bonds. We report the existence of pH‐dependent conformational changes within G2 and in G4–6 that differ from those induced by calcium, and that low pH overrides the requirement for calcium for actin‐binding within G4–6 to a modest extent so that a Kd of 1 µm is measured, compared to 30–40 nm in the presence of calcium. Whereas the pH‐dependent conformational change in G2 is possibly different from the change induced by calcium, the changes measured in G4–6 appear to be similar in both calcium and low pH.
Impacts of grazing and burning on spider assemblages in dry eucalypt forests of north‐eastern New South Wales, Australia
Authors: HARRIS REBECCA , YORK ALAN , BEATTIE ANDREW J.
Published: October 2003

Abstract In the dry eucalypt forests of north‐eastern New South Wales, Australia, cattle grazing occurs at low intensities and is accompanied by frequent low‐intensity burning. This study investigated the combined effects of this management practice on the ground‐dwelling and arboreal (low vegetation) spider assemblages. Spiders were sampled at 49 sites representing a range of grazing intensities, using pitfall trapping, litter extraction and sweep sampling. A total of 237 spider morphospecies from 37 families were collected using this composite sampling strategy. The abundance, richness, composition and structure of spider assemblages in grazed and ungrazed forest sites were compared and related to a range of environmental variables. Spider assemblages responded to a range of environmental factors at the landscape, habitat and microhabitat scales. Forest type, spatial relationships and habitat variability at the site scale were more important in determining spider assemblages than localized low‐intensity grazing and burning. However, it is possible that a threshold intensity of grazing may exist, above which spiders respond to grazing and burning. Although low‐intensity grazing and burning may not affect spider assemblages below a threshold stocking rate, that stocking rate has yet to be established.
Temporal Complexity of Repolarization and Mortality in Patients with Implantable Cardioverter Defibrillators
Authors: PERKIOMAKI JUHA S. , COUDERC JEAN‐PHILIPPE , DAUBERT JAMES P. , ZAREBA WOJCIECH
Published: October 2003

Increased repolarization variability has been observed in various cardiac conditions. However, data on its relation to heart rate variability and on its value in predicting adverse outcomes in high risk patients are limited. Forty‐seven patients with decreased left ventricular function and ICDs had high resolution 10‐minute ECG recordings and were followed for 781 ± 258 days (mean ± SD) on average. The interval from the R peak to the T wave peak with maximum amplitude (RTmax) and from the R peak to the T wave offset (RToff) were determined automatically on a beat‐to‐beat basis. Temporal beat‐to‐beat RTmax and RToff variability were analyzed using traditional summary statistics, a complexity measure (approximate entropy [ApEn]), and the short‐term scaling exponent (α1). Eight (17%) patients died and 16 (34%) patients experienced death/appropriate ICD shock during follow‐up. RTmax‐ApEn was significantly higher in patients who died compared with patients who survived (1.24 ± 0.13vs1.01 ± 0.21, respectively, P = 0.008). When RTmax‐ApEn was tested together with the α1 of the RR intervals, occurrence of ventricular arrhythmias before ICD implantation, and β‐blockers usage in the Cox regression analysis, it still independently predicted mortality; hazard ratio = 3.36 (1.28–8.83, 95% CI, P = 0.014) for every 0.10‐increase in RTmax‐ApEn. None of the repolarization variability parameters independently predicted death/appropriate ICD shocks. Increased temporal complexity of repolarization (RTmax‐ApEn) independently predicts mortality in ICD patients. (PACE 2003; 26:1931–1936)
Nonthoracotomy Implantable Defibrillator Lead Extraction:
Authors: SAAD EDUARDO B. , SALIBA WALID I. , SCHWEIKERT ROBERT A. , AL‐KHADRA AYMAN S. , ABDUL‐KARIM AHMAD , NIEBAUER MARK J. , WILKOFF BRUCE L.
Published: October 2003

Extraction of pacemaker leads has been demonstrated to be successful and safe in experienced hands using current tools. Whether application of such techniques and tools yield similar results among patients undergoing extraction of nonthoracotomy implantable defibrillator leads is unknown. This report describes a retrospective analysis of indications, techniques used, and outcome of patients who had a single ventricular nonthoracotomy implantable defibrillator lead extracted at The Cleveland Clinic Foundation. Results were compared to a matched population of patients undergoing extraction of ventricular pacemaker leads from a national registry and to the experience with pacemaker lead extraction at The Cleveland Clinic Foundation. Successful complete extraction of ventricular nonthoracotomy implantable defibrillator leads, in the absence of major complications, was achieved in 96.9% of attempts to extract leads from 161 patients. Clinical success was achieved in 98.1% of patients. Failure occurred in three patients. Two patients had major complications, including one death. The most common indication for extraction was infection (46.6%), followed by lead failure (34.2%). Procedure (140.8 vs 171.2 minutes, P < 0.01) and fluoroscopy (9.9 vs 11.0 minutes, P < 0.01) times compared favorably with those obtained from the pacemaker lead extraction database. Use of LASER did not influence the safety of the procedure or fluoroscopy times. Extraction of ventricular nonthoracotomy implantable defibrillator leads using currently available tools is a complex but effective procedure. In experienced hands, excellent success rates should be achieved with a low incidence of complications. (PACE 2003; 26:1944–1950)
Predictors and Clinical Impact of Atrial Fibrillation After Pacemaker Implantation in Elderly Patients Treated with Dual Chamber Versus Ventricular Pacing
Authors: STAMBLER BRUCE S. , ELLENBOGEN KENNETH A. , ORAV E. JOHN , SGARBOSSA ELENA B. , MARK ESTES N. A. , RIZO‐PATRON CARLOS , KIRCHHOFFER JAMES B. , HADJIS TOM A. , GOLDMAN LEE , LAMAS GERVASIO A. ,   Pacemaker Selection in the Elderly (PASE) Trial Investigators
Published: October 2003

The Pacemaker Selection in the Elderly (PASE) trial was a prospective, multicenter, single blind, randomized comparison of single chamber, rate adaptive, ventricular pacing (VVIR) with dual chamber, rate adaptive pacing (DDDR) in 407 patients aged ≥65 years
(mean 76 ± 7 years, 60% male)
with standard bradycardia indications for dual chamber pacemaker implantation. The incidence, predictors, and clinical consequences of atrial fibrillation (AF) developing after pacemaker implantation in the PASE trial were studied prospectively. During a median follow‐up of 18 months, AF developed in 73 (18%) patients. Kaplan‐Meier estimated cumulative incidences of AF in patients with sinus node dysfunction (n = 176) at 18 months were 28% in the VVIR and 16% in the DDDR groups (P = 0.08). After adjustment for other clinical variables using a Cox multivariate regression model, randomization to VVIR compared with DDDR pacing mode among patients with sinus node dysfunction was independently associated with a 2.6‐fold increased relative risk (RR) of developing AF after pacemaker implantation (P = 0.01). Other independent clinical risk factors for development of postimplant AF included a preimplant history of hypertension (P = 0.02) or supraventricular tachyarrhythmias
(P < 0.04). Patients who developed AF had similar health related quality of life scores and cardiovascular functional status after 18 months of pacing as patients who remained free of AF. The RR of death, stroke, or heart failure hospitalization was not increased in patients who developed AF. Thus, in the elderly patients with sinus node dysfunction requiring permanent pacing, DDDR pacing mode protected against the development of AF. However, development of AF after pacemaker implantation in this population was not associated with a significant impact on quality‐of‐life, functional status, or other clinical endpoints during 18 months of follow‐up. (PACE 2003; 26:2000–2007)
The morphology and ecology of Dipolydora armata (Polychaeta, Spionidae) from the western Mediterranean Sea
Authors: Bick Andreas
Published: October 2003

Bick. A. 2001. The morphology and ecology of Dipolydora armata (Polychaeta, Spionidae) from the western Mediterranean Sea. —Acta Zoologica (Stockholm) 82: 177–187

The cosmopolitan spionid Dipolydora armata is a dominant species of epifauna on Thais haemastoma shells in the western Mediterranean Sea. Some characters, particularly number, thickness and arrangement of notopodial spines, were extremely variable among specimens. Three morphological forms were distinguished based on the general appearance of the bundles of spines; one form possesses at least one bundle of stout spines, whereas bundles of medium spines or thinner acicular spines characterise the other forms. Differences in prostomial shape, as well as in the extension and form of the caruncle, were artefacts (preservation or angle of observation). The present study supports D. rogeri as a junior synonym of D. armata. D. armata was regularly found on shells inhabited by hermit crabs (Calcinus tubularis, Clibanarius erythropus) and on damaged, empty shells. Abundance, dominance, size frequency, occurrence of larvae and occurrence of regenerated specimens varied, possibly as a result of fouling strategy and recurrent settlements.
Variation in the stopover duration of Reed WarblersAcrocephalus scirpaceusin Morocco: effects of season, age and site
Authors: Rguibi‐Idrissi Hamid , Julliard Romain , Bairlein Franz
Published: October 2003

To test the prediction that stopover duration reflects the rate of body mass gain during stopover, the relationship between these two parameters was investigated in the Reed WarblerAcrocephalus scirpaceusat two sites in Morocco, Sidi Bou Ghaba on the Atlantic coast, and Kerbacha on the Mediterranean coast. Estimation of stopover duration was made using the recently published method by M. Schaubet al. We investigated effects of age and site on stopover parameters during autumn and spring migration. Stopover duration was longer for juveniles than for adults, longer at the Atlantic site than at the Mediterranean site and longer in autumn than in spring. Altogether, estimated stopover duration was longer than expected from previous studies based on minimum stopover duration. Body mass gain varied inconsistently among site, season and age classes, without a clear relation to stopover duration. This suggests that stopover duration is not dependent only on the rate of body mass gain.
Breeding biology and conservation of the Black‐vented Shearwater Puffinus opisthomelas
Authors: Keitt Bradford S. , Tershy Bernie R. , Croll Donald A.
Published: October 2003

The Black‐vented Shearwater Puffinus opisthomelas is endemic to the Pacific coast of Baja California, Mexico. We studied the breeding biology of this species at Natividad Island in 1997 and 1998. The colony at Natividad Island covers approximately 2.5 km2 and we estimated there to be 114 455 (± 27 520 95% CI) burrows in the colony. In 1997 burrow occupancy was 66.9%, providing a population estimate of 76 570 (± 18 411 95% CI) breeding pairs, representing about 95% of the world's population of this species. In 1997 the peak in egg laying occurred in early March and hatching began on 7 May. The incubation period averaged 51 days (± 6 sd) and chick rearing averaged 69 days (± 3 sd). In 1998 burrow occupancy was lower (19.6%) and nest initiation was later (peak egg laying in mid‐April), perhaps a result of El Niño conditions that prevailed in the Eastern Pacific at that time. We calculated that the development of the town and roads on Natividad Island have destroyed over 15% (26 532 burrows) of the breeding habitat on the island.
Oscillatory zoning in garnet from the Willsboro Wollastonite Skarn, Adirondack Mts, New York: a record of shallow hydrothermal processes preserved in a granulite facies terrane
Authors: Clechenko C. C. , Valley J. W.
Published: October 2003

Oscillatory zoning in low δ18O skarn garnet from the Willsboro wollastonite deposit, NE Adirondack Mts, NY, USA, preserves a record of the temporal evolution of mixing hydrothermal fluids from different sources. Garnet with oscillatory zoning are large (1–3 cm diameter) euhedral crystals that grew in formerly fluid filled cavities. They contain millimetre‐scale oscillatory zoning of varying grossular–andradite composition (XAdr = 0.13–0.36). The δ18O values of the garnet zones vary from 0.80 to 6.26‰ VSMOW and correlate with XAdr. The shape, pattern and number of garnet zones varies from crystal to crystal, as does the magnitude of the correlated chemistry changes, suggesting fluid system variability, temporal and/or spatial, over the time of garnet growth. The zones of correlated Fe content and δ18O indicate that a high Fe3+/Al, high δ18O fluid mixed with a lower Fe3+/Al and δ18O fluid. The high δ18O, Fe enriched fluids were likely magmatic fluids expelled from crystallizing anorthosite. The low δ18O fluids were meteoric in origin.

These are the first skarn garnet with oscillatory zoning reported from granulite facies rocks. Geochronologic, stable isotope, petrologic and field evidence indicates that the Adirondacks are a polymetamorphic terrane, where localized contact metamorphism around shallowly intruded anorthosite was followed by a regional granulite facies overprint. The growth of these garnet in equilibrium with meteoric and magmatic fluids indicates an origin in the shallow contact aureole of the anorthosite prior to regional metamorphism. The zoning was preserved due to the slow diffusion of oxygen and cations in the large garnet and protection from deformation and recrystallization in zones of low strain in thick, rigid, garnetite layers. The garnet provide new information about the hydrothermal system adjacent to the shallowly intruded massif anorthosite that predates regional metamorphism in this geologically complex, polymetamorphic terrane.
Stable isotope constraints on the Al2SiO5‘triple‐point’ rocks from the Proterozoic Priest pluton contact aureole, New Mexico, USA
Authors: Larson T. E. , Sharp Z. D.
Published: October 2003

The Priest pluton contact aureole in the Manzano Mountains, central New Mexico preserves evidence for upper amphibolite contact metamorphism and localized retrograde hydrothermal alteration associated with intrusion of the 1.42 Ga Priest pluton. Quartz–garnet and quartz–sillimanite oxygen isotope fractionations in pelitic schist document an increase in the temperatures of metamorphism from 540 °C, at a distance of 1 km from the pluton, to 690 °C at the contact with the pluton. Comparison of calculated temperature estimates with one‐dimensional thermal modelling suggests that background temperatures between 300 and 350 °C existed at the time of intrusion of the Priest pluton. Fibrolite is found within 300 m of the Priest pluton in pelitic and aluminous schist metamorphosed at temperatures >580 °C. Coexisting fibrolite and garnet in pelitic schist are in oxygen isotope equilibrium, suggesting these minerals were stable reaction products during peak metamorphism. The fibrolite‐in isograd is coincident with the staurolite‐out isograd in pelitic schist, and K‐feldspar is not observed with the first occurrence of fibrolite. This suggests that the breakdown of staurolite and not the second sillimanite reaction controls fibrolite growth in staurolite‐bearing pelitic schist. Muscovite‐rich aluminous schist locally preserves the Al2SiO5 polymorph triple‐point assemblage – kyanite, andalusite and fibrolite. Andalusite and fibrolite, but not kyanite, are in isotopic equilibrium in the aluminous schist. Co‐nucleation of fibrolite and andalusite at 580 °C in the presence of muscovite and absence of K‐feldspar suggests that univariant growth of andalusite and fibrolite occurred. Kyanite growth occurred during an earlier regional metamorphic event at a temperature nearly 80 °C lower than andalusite and fibrolite growth. Quartz–muscovite fractionations in hydrothermally altered pelitic schist and quartzite are small or negative, suggesting that late isotopic exchange between externally derived fluids and muscovite, but not quartz, occurred after peak contact metamorphism and that hydrothermal alteration in pelitic schist and quartzite occurred below the closure temperature of oxygen self diffusion in quartz (<500 °C).
Association of the Heart Rate Turbulence with Classic Risk Stratification Parameters in Postmyocardial Infarction Patients
Authors: Jeron Andreas , Kaiser Tanja , Hengstenberg Christian , Löwel Hannelore , Riegger Günter AJ , Holmer Stephan
Published: October 2003

The heart rate turbulence (HRT) parameters were introduced for risk stratification of ventricular arrhythmias in postmyocardial infarction patients. However, the relationship of these parameters with other risk stratificators such as heart rate variability (HRV), repolarization parameters or left ventricular function is unknown. Furthermore, the influence of age and medication on HRT remains to be evaluated. Holter ECG's of 509 post‐MI patients (1–10 years after MI) were screened for single ventricular extrasystole. In 196 patients the parameters' turbulence onset (TO) and turbulence slope (TS) could be computed. A pathological TO (>0%) and TS (<2.5 ms) was found in 58 and 54 patients, respectively. HRT was not related to gender, but was correlated with age (TS: r = 0.209, P < 0.01). No relationship was observed between QT interval, QTc interval or QT dispersion and HRT parameters. Individuals with a pathological HRT showed decreased HRV values (e.g., PNN50: 2.8 vs. 11.5; P < 0.001). Of all MI patients with systolic left ventricular dysfunction (EF < 45%, n = 46), 18 showed a pathological TO (39%) compared to 34 out of 142 patients (24%) with an EF > 45%. In contrast, the percentage of pathological HRT was not different between patients with left ventricular hypertrophy (16 out of 59, 27%) compared to patients without LVH (38 out of 133, 28%). The HRT was pathological in 14 out of 24 patients with diabetes mellitus (58%) compared to 40 out of 172 (23%) normoglycemic patients (TO: −0.6 ± 3.1 vs. −2.5 ± 5.5, P < 0.02). HRT was similar in patients with ß‐blockers (n = 96) as in patients without ß‐blockers (n = 100).

In stable post‐MI patients, HRT is influenced by age and left ventricular function and correlates with heart rate variability. Therapy with ß‐blockers has no influence on HRT, while diabetic patients may have an increased likelihood of pathological HRT.
Are Reciprocal Changes a Consequence of “Ischemia at a Distance” or Merely a Benign Electrical Phenomenon? A Pulsed‐Wave Tissue Doppler Echocardiographic Study
Authors: Çelik Şükrü , Yilmaz Remzi , Baykan Merih , Örem Cihan , Erdöl Cevdet
Published: October 2003

Objectives: The aim of the present study was to investigate whether ST segment depression in precordial leads at the time of acute inferior myocardial infarction represents a reciprocal change rather than concurrent anterior wall ischemia on the surface electrocardiography.

Background: The mechanism of reciprocal ST segment depression during acute myocardial infarction is controversial. “Ischemia at a distance” or a benign electrical phenomenon has been implicated in numerous reports. Pulsed‐wave tissue Doppler (PWTD) echocardiography can be used to examine the regional diastolic motion of the left ventricular myocardial wall and may allow the detection of ischemic segments.

Methods: We evaluated regional myocardial ischemia using PWTD echocardiography in 48 patients with a first inferior wall myocardial infarction. The left ventricle was divided into 16 segments. PWTD echocardiographic velocities were obtained from each left ventricular segments.

Results: Reciprocal ST segment depression was present in 35 patients (Group 1) but not in the remaining 13 patients (Group 2). There were no significant differences between groups 1 and 2 with respect to systolic (S) (7.4 ± 1.1 vs 6.8 ± 0.9 cm/s; P > 0.05), early (E) (10.5 ± 2 vs 9.4 ± 1.2 cm/s; P > 0.05), and late (A) (9.5 ± 3.2 vs 8.5 ± 2.3 cm/s; P > 0.05) diastolic waves peak velocities, E/A ratio 1.1 ± 0.2 vs 1.1 ± 0.1; P > 0.05), Ewave deceleration time (DT) (92 ± 17 vs 101 ± 16 ms; P > 0.05) and regional relaxation time (RT) (82 ± 19 vs 93 ± 21 ms; P > 0.05) in anterior wall (basal levels), which correspond to reciprocal ST segment depression on electrocardiography. According to E/A ratio detected by PWTD echocardiography in anterior wall and anterior septum, patients with reciprocal ST segment depression were also divided into two groups: Group A, with E/A ratio > 1; Group B, with E/A ratio < 1. Among the 35 patients with reciprocal ST segment depression, anterior wall ischemia was present in 10 patients and absent in 25 patients, whereas anterior septal ischemia was present 12 patients and absent in 23 patients.

Conclusions: Reciprocal ST segment depression during the early phases of inferior infarction is an electrical reflection of primary ST segment elevation in the area of infarction.
Effect of rice lines transformed with Bacillus thuringiensis toxin genes on the brown planthopper and its predator Cyrtorhinus lividipennis
Authors: Bernal Carmencita C. , Aguda Remedios M. , Cohen Michael B.
Published: October 2003

Five transgenic rice lines, each containing an insecticidal toxin gene from Bacillus thuringiensis (Bt) under control of a different promoter, were tested for effects on two non‐target insects: the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae), and its predator Cyrtorhinus lividipennis (Hemiptera: Miridae). Bt toxin was detected by ELISA in the honeydew of N. lugens that fed on rice lines with the CaMV 35S and actin promoters. Nilaparvata lugens produced greater volumes of acidic honeydew (derived from xylem feeding) on all five Bt rice lines than on non‐transgenic control lines. The amount of honeydew derived from phloem feeding did not differ between Bt and control lines. There were no differences between N. lugens reared on Bt and control lines in any of the five fitness parameters measured (survival to the adult stage, male and female weight, and male and female developmental time). There were no differences between C. lividipennis reared on N. lugens nymphs from Bt and control lines, in any of the three fitness parameters examined (survival to the adult stage and male and female developmental time). Our results indicate that N. lugens and its natural enemies will be exposed to Bt toxins from rice lines transformed with some Bt gene constructs, but that this exposure might not affect N. lugens and C. lividipennis fitness.
Induced resistance by Myzus persicae in the peach cultivar ‘Rubira’
Authors: Sauge Marie‐Hélène , Lacroze Jean‐Philippe , Poëssel Jean‐Luc , Pascal Thierry , Kervella Jocelyne
Published: October 2003

The effect of a previous infestation by the green peach aphid Myzus persicae (Sulzer) on the settling behaviour and reproduction of the same aphid species was investigated in the resistant peach cultivar Rubira, and compared with that observed in the susceptible control cultivar GF305. A previous infestation of 48 h triggered induced resistance in Rubira. There were significantly fewer aphids settling on preinfested than on uninfested plants, indicating an increased rejection of Rubira as a host plant. The level of induced resistance in preinfested plants was positively related to the duration of the first infestation. In GF305, previous infestation had no detrimental effect on aphid settlement and even slightly enhanced larviposition by adult females. The aphid probing behaviour after a 48‐h preinfestation was also monitored for 8 h with the electrical peneration graph (EPG) technique. On preinfested GF305, most EPG parameters indicated an enhanced host plant acceptance. On preinfested GF305, aphids produced less sieve element salivation and more continuous sap ingestion than on uninfested GF305, indicating that the previous aphids provoked changes in plant properties beneficial to the test aphids. In Rubira, a major induced factor of resistance was thought to be expressed in the sieve element as phloem sap ingestion was 4‐fold shorter on preinfested than on uninfested plants. The time taken by the aphid stylets to reach a sieve element was also significantly increased on preinfested Rubira, suggesting the induction of resistance factors outside the phloem. The originality of the Rubira/M. persicae interaction is discussed in the perspective of a better understanding of plant induced responses to aphids.
Stylet penetration behavior resulting in inoculation of a semipersistently transmitted closterovirus by the whitefly Bemisia argentifolii
Authors: Johnson D.D. , Walker G.P. , Creamer R.
Published: October 2003

The electrical penetration graph (EPG) technique was used to determine what part of stylet penetration behavior by the whitefly vector, Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae), is lettuce chlorosis virus (LCV) inoculated in the host plant Malva parviflora L. LCV is a semipersistently‐transmitted closterovirus. Since closteroviruses generally are found in the phloem of their plant hosts, this study tested the hypothesis that virus inoculation occurs during the phloem phase of stylet penetration behavior. Virus‐exposed whiteflies were allowed to feed on uninfected host plants, and the whiteflies were divided into two experimental groups: group 1 attained phloem phase on the uninfected plants, and group 2 did not attain phloem phase. Two series of tests were conducted, one where whiteflies were manipulated so that the amount of time spent in non‐phloem phase stylet penetration behaviors was similar between group 1 and group 2, and a second series of tests where whiteflies were manipulated so that the number of intracellular punctures made during stylet penetration was similar between group 1 and group 2. Both series of tests indicated that virus inoculation took place primarily during phloem phase. Considering only individual whiteflies shown to be capable of transmitting virus, 11 of 23 whiteflies (48%) in the phloem phase treatment successfully inoculated the virus whereas only one of 19 whiteflies (5%) in the non‐phloem phase treatment successfully inoculated the virus (P= 0.00008).
A rapid hypersensitive response associated with resistance in the willow Salix viminalis against the gall midge Dasineura marginemtorquens
Authors: Ollerstam Olof , Rohfritsch Odette , Höglund Solveig , Larsson Stig
Published: October 2003

Great genotypic variation in resistance against the gall midge Dasineura marginemtorquens Bremi (Diptera: Cecidomyiidae) exists within its willow host Salix viminalis L. (Salicaceae). In some resistant genotypes larvae die within 40 h after attempting to initiate galls. The present study tested the hypothesis that the hypersensitive response (HR) is involved in incompatible interactions between D. marginemtorquens and S. viminalis. By means of UV/blue light and visible light microscopy, we verified a rapidly (within 12 h after egg hatch) spreading cell death of an HR‐type due to larval attack in resistant willow genotypes. Twelve h after egg hatch, the cell death had spread up to six cell layers in resistant S. viminalis genotypes whereas in susceptible genotypes only up to two cell layers were affected. In the groups of dead cells on the resistant genotypes accumulation of phenolics was observed within 24 h after egg hatch. The rapidity of the cell death induction, the early local accumulation of phenolic compounds, and the strong association of the cell death with larval mortality suggest that the formation of dead cells in resistant willow genotypes should be interpreted as a true HR.
Attraction and feeding responses of Mediterranean fruit fly and a natural enemy to protein baits laced with two novel toxins, phloxine B and spinosada
Authors: Vargas Roger I. , Miller Neil W. , Prokopy Ronald J.
Published: October 2003

Studies were conducted to determine attraction and feeding propensity of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), to different protein bait mixtures with and without the insecticides malathion, spinosad, and phloxine B. Protein baits were more attractive to females than to males. Protein‐starved females responded more than protein‐fed females. The type of protein (USB® yeast hydrolysate enzymatic, Mazoferm®E802, Nu‐Lure®Insect Bait, or Provesta® 621 autolyzed yeast extract) in the bait had a major influence on C. capitata attraction, which was strongest to fresh Provesta. Aged baits (four day‐old) were not as attractive as fresh baits. In feeding propensity studies, highest response was observed for USB protein. On the basis of attraction and feeding responses Provesta (attraction and feeding) and USB (feeding) outperformed the standard Nu‐Lure. Protein‐starved flies were much more likely to feed on protein compared to protein‐fed flies. For protein‐starved flies, a mixture of Provesta and malathion repelled fruit flies, compared to a mixture of Provesta and spinosad or phloxine B. This was not the case with protein–fed flies. The wasp Fopius arisanus (Sonan), one of C. capitata's primary natural enemies in Hawaii, would not consume protein baits. Our studies suggest that spinosad or phloxine B, with low contact toxicity, mixed with protein baits offers a more environmentally friendly choice for control of C. capitata and conservation of F. arisanus, whereby the nontarget effects of broad spectrum contact poisons such as malathion can be avoided. Presumably, due to greater selectivity with spinosad and phloxine B bait treatments, the host would be killed, but not the natural enemy.
Interaction between insect strain and artificial diet in diamondback moth development and reproduction
Authors: Carpenter James E. , Bloem Stephanie
Published: October 2003

The economical production of physiologically and behaviorally competent diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is critical to most research and control programs against this insect. Although a few laboratory‐adapted colonies are currently maintained on artificial diets, the establishment and adaptation of feral DBM onto semi‐synthetic diets is often difficult. Understanding the interactions between insect strain and diet may be critical to the process of laboratory adaptation as well as to the successful use of laboratory‐reared insects in the field. As such, the objective of this study was to investigate the interaction between several DBM colonies/strains and different natural and semi‐synthetic diets. Specifically, we examined the effect of different diets on the length of development, percent survival, adult weight, female fecundity, and adult longevity for two feral and one laboratory‐adapted strain of DBM. Significant interactions were observed between diet and laboratory‐adapted and feral strains, and also between diet and different feral strains with respect to many of the growth and development parameters tested. Therefore, the performance of one strain of DBM on a particular diet was not necessarily predicted by the performance of another DBM strain on the same diet. However, the soy‐based diet developed and reported herein performed well for all three DBM strains tested. In future efforts to colonize feral DBM, we suggest that researchers assay different diet formulations in order to identify a semi‐synthetic diet that is most suitable for the particular DBM strain under consideration.
Kairomones from scarabaeid grubs and their frass as cues in below‐ground host location by the parasitoids Tiphia vernalis and Tiphia pygidialis
Authors: Rogers Michael E. , Potter Daniel A.
Published: October 2003

Cues used in below‐ground host‐searching behaviour and host discrimination were examined for Tiphia vernalis Rohwer and Tiphia pygidialis Allen (Hymenoptera: Tiphiidae), ecto‐parasitoids of root‐feeding larvae of the Japanese beetle, Popillia japonica Newman, and masked chafers, Cyclocephala spp. (Coleoptera: Scarabaeidae), respectively. Response to potential stimuli was compared in dual choice tests in an observation chamber filled with soil. Each wasp showed species‐specific, directed movement along residual body odor trails made by dragging its respective host through the soil. Presence of a grub was not necessary for wasps to follow such trails. Frass from either host‐ or non‐host grubs elicited trail‐following, but each Tiphia species followed frass trails from its respective host when a choice was presented. Frass trails elicited stronger responses than body odor trails. The combination of host frass and body odor elicited the strongest trail‐following responses. Our results suggest that once in the soil, Tiphia spp. locate their hosts using contact kairomones present in grub body odor trails and frass.
Biological differences in reproductive strategy between the mosquito sibling species Anopheles gambiae sensu stricto and An. quadriannulatus
Authors: Takken Willem , Stuke Kristin , Klowden Marc J.
Published: October 2003

Females of the afrotropical mosquito species Anopheles gambiae Giles sensu stricto and An. quadriannulatus (Theobald) (Diptera: Culicidae) were studied for the effect of blood meal size and the frequency of blood feeding on reproductive development during the first gonotrophic cycle. To standardize the blood meals, meals were administered by enema in some experiments. The effects of insemination, mosquito size, and metabolic reserves at emergence on egg development were also investigated. Maximum insemination was reached after seven days, varying from 62% in An. quadriannulatus to 95% in An. gambiae and was significantly different (P<0.05) between the two species. Insemination had no effect on feeding success. Females of An. quadriannulatus were significantly larger than An. gambiae females (mean wing size 2.90 ±0.01 mm versus 2.82 ±0.01 mm), but the protein, glycogen, and lipid content of newly emerged females of the two species were not significantly different. Without a blood meal, larger females of both species were significantly more likely to develop oocytes up to Christopher's stage II. With one blood meal, 27% of An. gambiae became pre‐gravid and 73% matured eggs. In contrast, all An. quadriannulatus females remained in the pre‐gravid stage following ingestion of one blood meal. Vitellogenesis was significantly reduced in smaller‐sized pre‐gravid An. quadriannulatus compared to larger individuals. When given the opportunity to feed up to three times on three successive days, all females of An. gambiae matured eggs but only 85% of An. quadriannulatus did so. When 1 μl of human blood was administered by enema, none of the females of either species developed eggs. With a single enema of 1.5 μl of human blood, only An. gambiae developed eggs. A similar result was observed with 1 μl and 1.5 μl enemas of bovine blood although some An. gambiae also developed eggs with 1 μl of blood. Anopheles quadriannulatus developed eggs only when given two 1 μl enemas on successive days. However, the percentage of females developing eggs was significantly lower than that of An. gambiae. The implications of these differences in reproductive strategy are discussed in the light of behavioural traits in the field.
Foliar pubescence and resistance to potato moth, Phthorimaea operculella, in Lycopersicon hirsutum
Authors: Gurr G.M. , McGrath D.
Published: October 2003

Pubescence characteristics for six accessions of Lycopersicon hirsutum Dunal and five accessions of L. hirsutum f. glabratum CH Mull. were determined and compared with those of an accession of cultivated tomato (L. esculentum Mill.). Removal of trichome exudates from excised leaflets using ethanol solution resulted in a reduced mortality and increased survival of potato moth (Phthorimaea operculella (Zeller)) neonates for the accessions that were most lethal when not treated with ethanol solution. No such treatment effect was evident for L. esculentum or for the L. hirsutum accession with least effect on neonates when its trichomes were intact. In a glasshouse experiment with caged intact plants, mortality of neonate P. operculella placed on the abaxial surface was greater on seven accessions than for L. esculentum. Neonates were less severely affected on the adaxial surface. Eleven days after inoculation, no live larvae were found on LA 1927, PI 127827, PI 134418, and PI 134428, and numbers on other accessions were lower than for L. esculentum. Eventual emergence of adults followed a similar trend. Multiple regression of insect data against pubescence indicated a significant correlation between density of type IV and VI trichomes and neonate mortality, decreased larval development and decreased adult emergence. Non‐glandular type V trichomes were positively correlated with high survival of insects to 11 days and to adult. Though factors other than glandular trichomes are likely to be important, increased density of type IV and VI, along with reduced type V, are shown to be important to select in breeding for P. operculella resistance.
Effect of differential host exposure on reproduction in the solitary ectoparasitoid Eupelmus vuilleti
Authors: Darrouzet Eric , Huignard Jacques , Chevrier Claude
Published: October 2003

We examined self‐superparasitism in Eupelmus vuilleti (CRW.), a solitary ectoparasitoid of larvae of Callosobruchus maculatus (F.) which develop in cowpea seeds. The reproduction of isolated females was analysed in the presence of seeds containing 10 or 30 hosts for 24, 48, and 72 h. At the two host densities, female reproductive activity increased with host exposure time, but variations in offspring number per female were limited. The propensity of the females to self‐superparasitise their hosts after long exposure times could explain these results. The offspring sex ratio was female biased but tended to 0.5 for longer exposure times. The absence of host renewal for a 3‐day period was followed by an increase in self‐superparasitism which reduced the parasitoid survival rate and by emergence of a lower number of females in the offspring. The offspring production was then analysed when females were provided with ten hosts a day or with 30 hosts every three days throughout their life span. The reduction of host renewal frequency did not affect male production but caused a reduction in the number of females emerging from the seeds. The importance of a high rate of self‐superparasitism on the population biology of this parasitoid is discussed.