bluuebunny/crossref_metadata_2025 huggingface dataset:
Race, Money and Medicines
Authors: Bloche M. Gregg
Published: September 2006

Taking notice of race is both risky and inevitable, in medicine no less than in other endeavors. The literature on race as a classifying tool in clinical research poses this core dilemma: On the one hand, race can be a useful stand-in for unstudied genetic and environmental factors that yield differences in disease expression and therapeutic response. On the other hand, racial distinctions have social meanings that are often pejorative or worse, especially when these distinctions are cast as culturally or biologically fixed. Our country's troubled past in this regard and the persistence of race-related disadvantage should keep us on notice about this hazard. Yet paying attention to race in order to ameliorate past wrongs sometimes supports the quest for social justice, as Dorothy Roberts points out in this issue. And at times, as Jay Cohn and Raj Bhopal note, attention to race can make a therapeutic difference, to the point of saving lives.
Ethical Considerations in the Conduct of Electronic Surveillance Research
Authors: Bharucha Ashok J. , London Alex John , Barnard David , Wactlar Howard , Dew Mary Amanda , Reynolds Charles F.
Published: September 2006

Nearly 2.5 million Americans currently reside in nursing homes and assisted living facilities in the United States, accounting for approximately five percent of persons sixty-five and older. The aging of the “Baby Boomer” generation is expected to lead to an exponential growth in the need for some form of long-term care (LTC) for this segment of the population within the next twenty-five years. In light of these sobering demographic shifts, there is an urgency to address the profound concerns that exist about the quality-of-care (QoC) and quality-of-life (QoL) of this frailest segment of our population.
Reviews in Medical Ethics
Authors: Herrick Susan
Published: September 2006

The Bazelon Center for Mental Health Law (the Center), founded as the Mental Health Law Project by a group of attorneys and mental health professionals, has been a major advocacy force promoting the civil rights of persons with mental disabilities since the 1972 New York Willowbrook litigation.

Named for D. C. Circuit Court of Appeals Judge David L. Bazelon, whose opinions first articulated the principles that the mentally disabled have a right to treatment in the least restrictive alternative setting, the Center has actively pursued greater rights for the mentally disabled in housing, education, and federal entitlements such as Medicaid, as well as in treatment-related issues.
Recent Developments in Health Law
Authors: Falit Benjamin P. , Sclar David
Published: September 2006

In his State of the Union address on January 31, 2006, President George W. Bush asserted: “for all Americans, we must confront the rising cost of care, strengthen the doctor-patient relationship, and help people afford the insurance coverage they need.” Soon thereafter, the White House National Economic Council released a summary of President Bush's plans for health care reform. The Bush plan argues that increased consumer control over health care purchasing decisions will go a long way to solving America's health care woes. By making patients more value-conscious consumers, the Bush Administration hopes to reduce costs, improve quality and increase competition within the health care sector.

The problem of rising health care costs is not new. In fact, President Bush's statement could have come from any American President in the last fifty years.
Prior sustained hypoxia attenuates interaction between hypoxia and exercise as ventilatory stimuli in humans
Authors: Wood Helen E. , Fatemian Marzieh , Robbins Peter A.
Published: September 2006

Both exercise and hypoxia increase pulmonary ventilation. However, the combined effects of the two stimuli are more than additive, such that exercise may be considered to potentiate the acute ventilatory response to hypoxia (AHVR), and vice versa. Exposure to sustained hypoxia of 8 h duration or more has been shown to increase the acute chemoreflex responses to hypoxia and hypercapnia. The purpose of this study was to determine whether sustained exposure to hypoxia also changed the stimulus interaction between the effects of exercise and hypoxia on ventilation. Ten subjects undertook two main protocols on two separate days. On one day, subjects were exposed to isocapnic hypoxia (IH) at an end‐tidal partial pressure of O2 of 55 mmHg and on the other day, subjects were exposed to air as a control (C). Before and after each exposure, the sensitivity of AHVR was assessed during both resting conditions and exercise at 35% of the subjects' maximal oxygen uptake capacity. Average values (means ±s.d.) obtained for the sensitivity of AHVR from protocol IH were 0.85 ± 0.35 (rest, prehypoxic exposure), 1.60 ± 0.66 (exercise, prehypoxic exposure), 1.69 ± 0.63 (rest, posthypoxic exposure) and 1.81 ± 0.86 l min−1%−1 (exercise, posthypoxic exposure). A non‐dimensional variable, Φ, was used to quantify the interaction present between exercise and hypoxia. The variable Φ fell significantly following the sustained exposure to hypoxia (P < 0.02, ANOVA), indicating that the degree of stimulus interaction between acute hypoxia and exercise had declined. We suggest that the mechanisms by which sustained hypoxia modifies peripheral chemoreflex function may also modify the effects of exercise on the peripheral chemoreflex.
Relationships between nitric oxide‐mediated endothelial function, eNOS coupling and blood pressure revealed by eNOS–GTP cyclohydrolase 1 double transgenic mice
Authors: Adlam D. , Bendall J. K. , De Bono J. P. , Alp N. J. , Khoo J. , Nicoli T. , Yokoyama M. , Kawashima S. , Channon K. M.
Published: September 2006

Endothelium‐dependent relaxation in conduit vessels is mediated largely by nitric oxide (NO), produced by the enzyme endothelial nitric oxide synthase (eNOS) in the presence of the cofactor tetrahydrobiopterin (BH4) and mediated through a cGMP‐dependent downstream signalling cascade. Endothelial NOS regulates blood pressure in vivo, and impaired endothelial NO bioactivity in vascular disease states may contribute to systemic hypertension. In the absence of sufficient levels of the cofactor BH4, NO becomes uncoupled from arginine oxidation and eNOS produces superoxide rather than NO. The enzymatic uncoupling of eNOS is an important feature of vascular disease states associated with increased oxidative stress. However, whether eNOS coupling, rather than overall eNOS activity, has specific effects on endothelium‐dependent vasorelaxation in vitro, or on blood pressure regulation in vivo, remains unclear. In this study, we evaluate the relationships between blood pressure and endothelial function in models of eNOS uncoupling, using mice with endothelium‐targeted transgenic eNOS overexpression (eNOS‐Tg), in comparison with littermates in which eNOS coupling was rescued by additional endothelium‐targeted overexpression of GTP cyclohydrolase 1 (eNOS/GCH‐Tg) to increase endothelial BH4 levels. Despite the previously characterized differences in eNOS‐dependent superoxide production between these animals, we find that blood pressure is equally reduced in both genotypes, compared with wild‐type animals. Furthermore, both eNOS‐Tg and eNOS/GCH‐Tg mice exhibit similarly impaired endothelium‐dependent vasorelaxation. We show that reduced vasorelaxation responses result from desensitization of cGMP‐mediated signalling and are associated with increased NO production rather than changes in superoxide production.
Carotid baroreceptor stimulation alters cutaneous vascular conductance during whole‐body heating in humans
Authors: Keller David M. , Davis Scott L. , Low David A. , Shibasaki Manabu , Raven Peter B. , Crandall Craig G.
Published: September 2006

Prior studies investigating carotid baroreflex control of the cutaneous vasculature have yielded mixed findings. However, previously used methodological and analytical techniques may limit the ability to detect carotid baroreflex‐mediated changes in cutaneous vascular conductance (CVC). The aim of this study was to test the hypothesis that dynamic carotid baroreceptor stimulation (i.e. 5 s trials) using neck pressure (NP, simulated carotid hypotension) and neck suction (NS, simulated carotid hypertension) will decrease and increase CVC, respectively, during normothermic and whole‐body heating conditions in resting humans. Data were obtained from nine subjects (age, 31 ± 2 year). The ratio of forearm skin blood flux (laser‐Doppler flowmetry) and arterial blood pressure (Finapres) was used as an index of CVC. Multiple 5 s trials of NP (+40Torr) and NS (−60Torr), as well as breath‐hold/airflow control trials, were applied during end‐expiratory breath‐holds while subjects were normotheric and heat stressed (change in core temperature ∼0.75°C). CVC responses to each NP and NS trial were averaged into 1 s intervals during the following periods: 3 s prestimulus, 5 s during stimulus, and 5 s poststimulus. Peak CVC responses (3 s average) to NP and NS were compared to prestimulus values using paired t test. During normothermia, NP decreased CVC by 0.032 ± 0.007 arbitrary units (a.u.) mmHg−1; (P < 0.05); however, breath‐hold/airflow control trials resulted in similar decreases in CVC. NS did not change CVC (Δ= 0.002 ± 0.005 a.u. mmHg−1; P= 0.63). During whole‐body heating, NP decreased CVC (by 0.16 ± 0.04 a.u. mmHg−1; (P < 0.05), whereas NS increased CVC by 0.07 ± 0.03 a.u. mmHg−1; (P < 0.05). Furthermore, these changes were greater than, or directionally different from, the breath‐hold/airflow control trials. These findings indicate that carotid baroreceptor stimulation elicits dynamic changes in CVC and that these changes are more apparent during whole‐body heating.
Modelling spinal circuitry involved in locomotor pattern generation: insights from the effects of afferent stimulation
Authors: Rybak Ilya A. , Stecina Katinka , Shevtsova Natalia A. , McCrea David A.
Published: September 2006

A computational model of the mammalian spinal cord circuitry incorporating a two‐level central pattern generator (CPG) with separate half‐centre rhythm generator (RG) and pattern formation (PF) networks has been developed from observations obtained during fictive locomotion in decerebrate cats. Sensory afferents have been incorporated in the model to study the effects of afferent stimulation on locomotor phase switching and step cycle period and on the firing patterns of flexor and extensor motoneurones. Here we show that this CPG structure can be integrated with reflex circuits to reproduce the reorganization of group I reflex pathways occurring during locomotion. During the extensor phase of fictive locomotion, activation of extensor muscle group I afferents increases extensor motoneurone activity and prolongs the extensor phase. This extensor phase prolongation may occur with or without a resetting of the locomotor cycle, which (according to the model) depends on the degree to which sensory input affects the RG and PF circuits, respectively. The same stimulation delivered during flexion produces a temporary resetting to extension without changing the timing of following locomotor cycles. The model reproduces this behaviour by suggesting that this sensory input influences the PF network without affecting the RG. The model also suggests that the different effects of flexor muscle nerve afferent stimulation observed experimentally (phase prolongation versus resetting) result from opposing influences of flexor group I and II afferents on the PF and RG circuits controlling the activity of flexor and extensor motoneurones. The results of modelling provide insights into proprioceptive control of locomotion.
Cell domain‐dependent changes in the glutamatergic and GABAergic drives during epileptogenesis in the rat CA1 region
Authors: El‐Hassar Lynda , Milh Mathieu , Wendling Fabrice , Ferrand Nadine , Esclapez Monique , Bernard Christophe
Published: September 2006

An increased ratio of the glutamatergic drive to the overall glutamatergic/GABAergic drive characterizes the chronic stage of temporal lobe epilepsy (TLE), but it is unclear whether this modification is present during the latent period that often precedes the epileptic stage. Using the pilocarpine model of TLE in rats, we report that this ratio is decreased in hippocampal CA1 pyramidal cells during the early phase of the latent period (3–5 days post pilocarpine). It is, however, increased during the late phase of the latent period (7–10 days post pilocarpine), via cell domain‐dependent alterations in synaptic current properties, concomitant with the occurrence of interictal‐like activity in vivo. During the late latent period, the glutamatergic drive was increased in somata via an enhancement in EPSC decay time constant and in dendrites via an increase in EPSC frequency and amplitude. The GABAergic drive remained unchanged in the soma but was decreased in dendrites, since the drop off in IPSC frequency was more marked than the increase in IPSC kinetics. Theoretical considerations suggest that these modifications are sufficient to produce interictal‐like activity. In epileptic animals, the ratio of the glutamatergic drive to the overall synaptic drive was not further modified, despite additional changes in synaptic current frequency and kinetics. These results show that the global changes to more glutamatergic and less GABAergic activities in the CA1 region precede the chronic stage of epilepsy, possibly facilitating the occurrence and/or the propagation of interictal activity.
Reversal of diet‐induced insulin resistance with a single bout of exercise in the rat: the role of PTP1B and IRS‐1 serine phosphorylation
Authors: Ropelle Eduardo R. , Pauli José R. , Prada Patrícia O. , De Souza Cláudio T. , Picardi Paty K. , Faria Marcel C. , Cintra Dennys E. , Fernandes Maria Fernanda de A. , Flores Marcelo B. , Velloso Lício A. , Saad Mario J. A. , Carvalheira José B. C.
Published: September 2006

Lifestyle interventions including exercise programmes are cornerstones in the prevention of obesity‐related diabetes. In this study, we demonstrate that a single bout of exercise inhibits high‐fat diet‐induced insulin resistance. Diet‐induced obesity (DIO) increased the expression and activity of the protein tyrosine phosphatase 1B (PTP1B) and attenuated insulin signalling in gastrocnemius muscle of rats, a phenomenon which was reversed by a single session of exercise. In addition, DIO was observed to lead to serine phosphorylation of insulin receptor substrate 1 (IRS‐1), which was also reversed by exercise in muscle in parallel with a reduction in c‐Jun N‐terminal kinase (JNK) activity. Thus, acute exercise increased the insulin sensitivity during high‐fat feeding in obese rats. Overall, these results provide new insights into the mechanism by which exercise restores insulin sensitivity.
Ca2+ sensitivity of regulated cardiac thin filament sliding does not depend on myosin isoform
Authors: Schoffstall Brenda , Brunet Nicolas M. , Williams Shanedah , Miller Victor F. , Barnes Alyson T. , Wang Fang , Compton Lisa A. , McFadden Lori A. , Taylor Dianne W. , Seavy Margaret , Dhanarajan Rani , Chase P. Bryant
Published: September 2006

Myosin heavy chain (MHC) isoforms in vertebrate striated muscles are distinguished functionally by differences in chemomechanical kinetics. These kinetic differences may influence the cross‐bridge‐dependent co‐operativity of thin filament Ca2+ activation. To determine whether Ca2+ sensitivity of unloaded thin filament sliding depends upon MHC isoform kinetics, we performed in vitro motility assays with rabbit skeletal heavy meromyosin (rsHMM) or porcine cardiac myosin (pcMyosin). Regulated thin filaments were reconstituted with recombinant human cardiac troponin (rhcTn) and α‐tropomyosin (rhcTm) expressed in Escherichia coli. All three subunits of rhcTn were coexpressed as a functional complex using a novel construct with a glutathione S‐transferase (GST) affinity tag at the N‐terminus of human cardiac troponin T (hcTnT) and an intervening tobacco etch virus (TEV) protease site that allows purification of rhcTn without denaturation, and removal of the GST tag without proteolysis of rhcTn subunits. Use of this highly purified rhcTn in our motility studies resulted in a clear definition of the regulated motility profile for both fast and slow MHC isoforms. Maximum sliding speed (pCa 5) of regulated thin filaments was roughly fivefold faster with rsHMM compared with pcMyosin, although speed was increased by 1.6‐ to 1.9‐fold for regulated over unregulated actin with both MHC isoforms. The Ca2+ sensitivity of regulated thin filament sliding speed was unaffected by MHC isoform. Our motility results suggest that the cellular changes in isoform expression that result in regulation of myosin kinetics can occur independently of changes that influence thin filament Ca2+ sensitivity.
Localized Temporal Change of the Earth's Inner Core Boundary
Authors: Wen Lianxing
Published: September 2006

Compressional waves of an earthquake doublet (two events occurring in the South Sandwich Islands on 1 December 1993 and 6 September 2003), recorded at three seismic stations in Russia and Kyrgyzstan and reflected off Earth's inner core boundary, arrived at least from 39 to 70 milliseconds earlier in the 2003 event than in the 1993 event. Such changes indicate that Earth's inner core radius enlarged locally beneath middle Africa by 0.98 to 1.75 kilometers between the times of these two events. Changes of the inner core radius may be explained by either a differential motion of the inner core, assuming that irregularities are present at the inner core boundary and fixed to the inner core, or a rapid growth of the inner core by this amount.
What do patients really want to know in an informed consent procedure? A questionnaire-based survey of patients in the Bath area, UK
Authors: El-Wakeel H , Taylor G J , Tate J J T
Published: September 2006

Background:Medical decision making is based on patient autonomy and informed consent, which is an integral part of medical ethics, risk management and clinical governance. Consent to treatment has been extensively discussed, but the viewpoint of patients is not well represented. A new consent form was introduced by the Department of Health in 2001.

Aims:To determine the information most important to patients, to facilitate evidence-based guidelines and to provide a valid and reliable consent-procedure-satisfaction questionnaire.

Methods:An anonymous quantitative survey was carried out, asking 100 patients 15 questions regarding procedures they may need to undergo, using a Visual Analogue Scale to test the importance of each question.

Results and discussion:In total there were 77 respondents and the mean age was 48.8 (SD 17.63, range 20–82) years. There were 52% women and 48% men. Major complications, such as not undergoing the procedure, future management and long-term effect on work, all scored a median of 95%. Least concerns were related to technical details of the procedure and minor complications (median 64% and 63%, respectively). All other questions were still considered important (median 79–93%). No significant differences were observed between sex, age and professional groups, but a significant difference was observed between the education groups. Qualifications of the doctor did not correlate to any other question.

Conclusions:This questionnaire is proposed as a basis for informed consent guidelines to health workers and for measures of satisfaction with the consent procedure.
Just another reproductive technology? The ethics of human reproductive cloning as an experimental medical procedure
Authors: Elsner D
Published: September 2006

Human reproductive cloning (HRC) has not yet resulted in any live births. There has been widespread condemnation of the practice in both the scientific world and the public sphere, and many countries explicitly outlaw the practice. Concerns about the procedure range from uncertainties about its physical safety to questions about the psychological well-being of clones. Yet, key aspects such as the philosophical implications of harm to future entities and a comparison with established reproductive technologies such as in vitro fertilisation (IVF) are often overlooked in discussions about HRC. Furthermore, there are people who are willing to use the technology. Several scientists have been outspoken in their intent to pursue HRC. The importance of concerns about the physical safety of children created by HRC and comparisons with concerns about the safety of IVF are discussed. A model to be used to determine when it is acceptable to use HRC and other new assisted reproductive technologies, balancing reproductive freedom and safety concerns, is proposed. Justifications underpinning potential applications of HRC are discussed, and it is determined that these are highly analogous to rationalisations used to justify IVF treatment. It is concluded that people wishing to conceive using HRC should have a prima facie negative right to do so.
Interactions of doctors with the pharmaceutical industry
Authors: Morgan M A , Dana J , Loewenstein G , Zinberg S , Schulkin J
Published: September 2006

Objective:To assess the opinions and practice patterns of obstetrician-gynaecologists on acceptance and use of free drug samples and other incentive items from pharmaceutical representatives.

Methods:A questionnaire was mailed in March 2003 to 397 members of the American College of Obstetricians and Gynecologists who participate in the Collaborative Ambulatory Research Network.

Results:The response rate was 55%. Most respondents thought it proper to accept drug samples (92%), an informational lunch (77%), an anatomical model (75%) or a well-paid consultantship (53%) from pharmaceutical representatives. A third (33%) of the respondents thought that their own decision to prescribe a drug would probably be influenced by accepting drug samples. Respondents were more likely to think the average doctor’s prescribing would be influenced by acceptance of the items than theirs would be (p<0.002). Respondents who distributed drug samples to patients indicated doing so because of patients’ financial need (94%) and for their convenience (76%) and less so as a result of knowledge of the efficacy of the sample product (63%). A third (34%) of respondents agreed that interactions with industry should be more strictly regulated.

Conclusion:Obstetrician-gynaecologists largely indicated that they would act in accordance with what they think is proper regarding accepting incentive items from pharmaceutical representatives. Although accepting free drug samples was considered to be appropriate more often than any other item, samples were most commonly judged to be influential on prescribing practices. The widely accepted practice of receiving and distributing free drug samples needs to be examined more carefully.
Dealing with ethical problems in the healthcare system in Lithuania: achievements and challenges
Authors: Bankauskaite V , Jakusovaite I
Published: September 2006

Ethical problems in healthcare in Lithuania are identified, existing mechanisms that deal with them are analysed and policy implications are discussed. At least three groups of ethical problems exist in the Lithuanian healthcare system: problems in the healthcare reform process, in interprofessional interaction and in doctor–patient relationships. During the past 15 years, several diverse legal, political and administrative mechanisms have been implemented in Lithuania to tackle these problems. Despite major achievements, numerous problems persist, implying that the focus should be shifted to different mechanisms and interventions. It is necessary to broaden the conceptual understanding of ethics in healthcare and focus on management ethics to tackle ethical problems in Lithuania or in other countries in transition.
Systematics and mating systems of two fungal pathogens of opium poppy: the heterothallicCrivellia papaveraceawith aBrachycladium penicillatumasexual state and a homothallic species with aBrachycladium papaverisasexual state
Authors: Inderbitzin Patrik , Shoemaker Robert A. , O'Neill Nichole R. , Turgeon B. Gillian , Berbee Mary L.
Published: September 2006

This paper presents a systematic revision of the fungal opium poppy (Papaver somniferum L.) pathogens formerly known as Pleospora papaveracea (de Not.) Sacc., along with allied asexual states formerly placed in Dendryphion . The revision is based on analysis of phylogenetic relationships, comparative morphology, and analysis of mating systems. Using morphology, 18S and ITS rDNA, we established that these species belong to the Alternaria group rather than to Pleospora, a conclusion supported by the Shimodaira–Hasegawa test. For these fungi, we erect the new genus Crivellia , with Crivellia papaveracea as type. ITS rDNA analyses suggested with moderate support Alternaria brassicicola (Schw.) Wiltshire, Alternaria japonica Yoshii, and Ulocladium alternariae (Cooke) Simmons as Crivellia’s closest relatives. Combined ITS, partial GPD and EF-1 alpha analyses confirmed earlier studies that show that asexual isolates in the Crivellia lineage of poppy pathogens represent two closely related species. Because Dendryphion was determined to be polyphyletic, the former genus Brachycladium was resurrected for B. penicillatum Corda and B. papaveris (K. Sawada) Shoemaker & Inderbitzin, the Crivellia asexual states that had been in Dendryphion. Molecular and morphological comparison with isolates from field-collected ascomata and morphological comparison with the type specimen of P. papaveracea indicated that B. penicillatum , and not B. papaveris , is the anamorph of C. papaveracea. The mycelia from single conidium or single ascospore isolates, including mycelia from 14 single ascospores from one field-collected C. papaveracea ascoma, either have a MAT1-1 or MAT1-2 gene and are thus heterothallic. In contrast, each single-conidium isolate of B. papaveris has an incomplete MAT1-2 gene fused to a MAT1-1 region and is inferred to be homothallic. We speculate that ancestral MAT fusion might have led to speciation in Crivellia.
Bimodal pollination system in rare endemic Oncocyclus irises (Iridaceae) of Lebanon
Authors: Monty Arnaud , Saad Layla , Mahy Grégory
Published: September 2006

Pollination systems based on indirect rewards, such as heat and shelter, have seldom been studied. Plant–pollinator interactions were characterized in Iris cedretii Dinsmore ex Chaudhary and Iris sofarana subsp. kasruwana Dinsmore ex Chaudhary, rare endemic Lebanese Oncocyclus irises exhibiting potential adaptation to shelter pollination. Despite a diversity of floral visitors (47 species), only two groups of Anthophoridae male bees ( Xylocopa spp. and Eucera spp.) could be considered as efficient pollinators on the basis of frequency of visits, visiting behaviour, and pollen load. Lebanese Oncocyclus irises showed a bimodal pollination system with (1) diurnal visits at low rates but with potentially large pollen transfers by Xylocopa bees, exhibiting a foraging-like behaviour, principally during warm periods of the day and (2) sheltering, especially Eucera male bees, during night and day when the weather is changeable. Refuge occurrence in flowers was more important during the night (27%) than during the day (12%) and, for daytime, during cloudy or windy than sunny conditions. It also varied depending on the exposure of floral tunnels. Visitation rates of both day-visiting Xylocopa and night-sheltering Eucera were negatively associated with an increase of the number of flowers per clump. No experimental evidence was found showing that the principal advantage for male bees to shelter in Iris flowers was to fly earlier in the morning.
Ultrastructure of the fungus Ophiodothella vaccinii in infected leaves of Vaccinium arboreum
Authors: Mims Charles W. , Hanlin Richard T. , Richardson Elizabeth A.
Published: September 2006

Light and electron microscopy were used to study the fungus Ophiodothella vaccinii E.S. Boyd in infected leaves of Vaccinium arboreum Marsh. This pathogen produces large lesions on leaves in which host cells are surrounded by intercellular hyphae and penetrated by intracellular hyphae. In this study, we examined details of acervuli that are produced on these lesions, the process of conidiogenesis that took place within acervuli, and the relationships between hyphae and host cells within lesions. Most acervuli developed on the adaxial leaf surface just beneath the epidermis, which also was permeated by fungal hyphae. The epidermis covering an acervulus separated from the underlying host cells as numerous conidia embedded in extracellular material accumulated within an acervulus. The raised portion of the epidermis formed a shield-like clypeus over the acervulus. Mature conidia coated with extracellular material were released through a small pore in the clypeus. A columnar mass of sterile hyphae was present in each acervulus near the pore region. This mass was surrounded by conidia embedded in extracellular material. Conidia arose from a layer of phialides present at the base of an acervulus. Phialides arose from both intercellular hyphae and intracellular hyphae that emerged from host cells and also were surrounded by extracellular material. In older lesions, O. vaccinii clearly functioned as a necrotroph. However, in young lesions, we found evidence indicating that some cells were alive when penetrated by hyphae. Hyphae were highly constricted at host cell wall penetration sites and intracellular hyphae commonly grew completely through infected host cells and directly into adjacent cells. Hyphae in older lesions became extremely thick walled and were packed with large lipid bodies.
Nutrient homeostasis, metabolism of reserves, and seedling vigor as affected by seed priming in coarse rice
Authors: Farooq M. , Basra S.M.A. , Khalid M. , Tabassum R. , Mahmood T.
Published: September 2006

The influence of seed priming on germination, seedling vigor, ion homeostasis, and starch metabolism in coarse rice was studied. Priming treatments included pregermination (a traditional soaking method being used for rice nursery preparation), hydropriming for 48 h, osmohardening with KCl or CaCl2(ψs –1.25 MPa solution) for 24 h, ascorbate priming (10 mg·L–1) for 48 h, and hardening for 24 h. Compared with controls, all priming treatments (except pregermination) reduced the time to start germination, improved the rate of germination and synchronization, and the length of shoot and root, seedling fresh and dry mass, number of secondary roots, the concentration of reducing sugars, and α-amylase activity, although the extent of these changes was different in seeds subjected to different treatments. These seed treatments resulted in higher germination that might be due to overcoming dormancy. Osmohardening with KCl was more effective than CaCl2for these parameters. Nitrogen concentration remained unaffected in seedlings; however, Ca2+concentrations in both seeds and seedlings were greater in seeds osmohardenerd with CaCl2than with all other treatments, including the control. Seed priming enhanced K+concentration in both seeds and seedlings, leading to improved α-amylase activity. There were positive correlations between seed K+concentration and amylase activity, and the concentration of reducing sugars with amylase activity, seedling dry mass, or number of secondary roots. Osmohardening with KCl performed better than all other treatments including control. Priming improved the K+balance that activates α-amylase, a basis for seed invigoration.
The angiosperm flora of the Archipelago Juan Fernandez (Chile): origin and dispersal
Authors: Bernardello Gabriel , Anderson Gregory J. , Stuessy Tod F. , Crawford Daniel J.
Published: September 2006

We review the hypothesized origin and the methods of arrival of the angiosperm colonists to the Juan Fernandez Islands. We also summarize the dispersal capabilities of the current flora, including data on fruit type, fruit length, and dispersal unit length, correlating these features with dispersal and establishment. Most species originated from South America, followed by Pantropical, Australian, New Zealand, and Pacific colonizers. Sea and land birds were the most important initial long-distance dispersal agents. Most colonizing species are hermaphroditic flowered, and thus all dispersal methods are represented among them. Monoecious, andromonoecious and gynomonoecious, dioecious, and polygamous species were mainly carried by birds. Most wind- and bird-pollinated colonizing genera arrived with birds as did most annual herbs and species with bright-colored flowers. In the current flora, the majority of the species have dry fruits. In monoecious, andromonoecious and gynomonoecious, and dioecious species, achenes predominate. Fleshy fruits are limited to perennials. Most species have medium to small dispersal units, and generally, the larger the flower, the larger the fruit. Large- and medium-sized dispersal units are common in shrubs and trees. Abiotic dispersal is common in the current flora, which may reflect the ancestral dispersal capability of the colonizers, or adaptation to the absence of a fauna to disperse seeds and fruits. Anemochorous and autochorous species are mainly perennial and have medium to large, unisexual flowers. Anemochorous species have small dispersal units and dull-colored flowers, whereas large dispersal units and brightly colored flowers are frequent in autochorous species. Medium-sized dispersal units are represented in autochorous or ornithochorous species. The establishment and evolution of this flora was previously discussed to have occurred with very few pollination and (or) reproductive options. This study suggests that elements associated with dispersal are also analogously limited.
Effect of ovule position on patterns of seed maturation and abortion in Robinia pseudoacacia (Fabaceae)
Authors: Susko David J.
Published: September 2006

I examined the effect of ovule position on patterns of ovule development within the linear pods of black locust, Robinia pseudoacacia L. Fruits were sampled from three sites in southwestern Ontario, Canada. Approximately two-thirds of all ovules failed to show visible signs of fertilization or development. Patterns of seed maturation and abortion within fruits were nonrandom and depended on ovule position. The probability of seed maturation within individual fruits decreased significantly from the distal to basal ends, suggesting the existence of a fertilization gradient. Seeds at the basal ends of fruits were also lighter than more distally located seeds. While seed mass did not influence the likelihood of germination, seed mass was positively correlated with seedling size. Hence, ovule position exerts an influence on offspring vigour and has the potential, ultimately, to affect plant fitness.
Getting the most out of fluorescent amplified fragment length polymorphism
Authors: Trybush Sviatlana , Hanley Steven , Cho Kang-Hyun , Jahodová Šárka , Grimmer Michael , Emelianov Igor , Bayon Carlos , Karp Angela
Published: September 2006

Amplified fragment length polymorphism (AFLP™) is one of the most widely applied molecular marker detection systems used today. Among the reasons for its popularity are its reproducibility, capacity to generate large numbers of data points in a single assay, and “off-the-shelf” universal applicability. The original AFLP protocol was developed using radioactive detection. The transfer of this technique to fluorescent detection on automated DNA fragment analysers not only removed the undesirable requirement for radioactivity but also provided the possibility for increased effectiveness and detection throughput. Unfortunately, a number of problems are frequently encountered with fluorescent AFLPs, particularly failure to amplify high molecular-weight fragments and generation of nonuniform peak distributions. Here, we describe an improved generic protocol for fluorescent AFLPs achieved mainly thorough optimization of the multiplexed selective amplification reaction. This improved protocol gives increased production of valuable high molecular-weight markers and uniform peak intensities, facilitating unambiguous scoring. The protocol has been successfully applied, without further optimization, to species of Salix and Populus (Salicaceae), Melampsora (Melampsoraceae, rust fungi) and Heracleum (Apiaceae), as well as sugar beet ( Beta vulgaris L. subsp. vulgaris , Amaranthaceae), the endangered species Ranunculus kadzunensis Makino (Ranunculaceae), and to Aphidius ervi Haliday (Braconidae), a parasitoid wasp.
Compensation through rosette formation: the response of scarlet gilia (Ipomopsis aggregata: Polemoniaceae) to mammalian herbivory
Authors: Becklin Katie M. , Kirkpatrick H. Elizabeth
Published: September 2006

Plants could potentially compensate for floral herbivory by regrowing flowering stalks and by forming additional vegetative stems. Because scarlet gilia (Ipomopsis aggregata (Pursh) V. Grant) is described as monocarpic, its ability to regrow multiple flowering stalks following the removal of its primary inflorescence has been cited as the species’ primary means of compensating for herbivory. However, ancillary rosette formation could also contribute to compensation in subsequent years. To determine if herbivory induces ancillary rosette formation and whether energy diverted to vegetative regrowth reduces reproductive output, we analyzed the response of scarlet gilia to elk herbivory in the Wenatchee National Forest of Washington State. Control plants were protected from herbivory by wire enclosures; clipped plants were hand-cut to simulate herbivory; and grazed plants were left vulnerable to elk herbivory. Ninety percent of plants that lost inflorescences regrew multiple flowering stalks; these plants produced fewer fruits and seeds than protected plants, indicating that scarlet gilia undercompensated for herbivory despite greater aboveground biomass. The plants that regrew multiple flowering stalks were also more likely to form ancillary rosettes, which could increase compensation over multiple seasons. Although herbivory reduced initial fecundity, grazing generated morphological changes that could enable the plant to achieve a greater degree of compensation over time.
Allosteric Modulation of G Protein–Coupled Receptors
Authors: May Lauren T. , Leach Katie , Sexton Patrick M. , Christopoulos Arthur
Published: September 2006

The past decade has witnessed a significant growth in the identification of allosteric modulators of G protein–coupled receptors (GPCRs), i.e., ligands that interact with binding sites that are topographically distinct from the orthosteric site recognized by the receptor's endogenous agonist. Because of their ability to modulate receptor conformations in the presence of orthosteric ligand, allosteric modulators can “fine-tune” classical pharmacological responses. This is advantageous in terms of a potential for engendering greater GPCR subtype-selectivity, but represents a significant challenge for detecting and validating allosteric behaviors. Although allosteric sites need not have evolved to accommodate endogenous ligands, there are a number of examples of where such modulators have been shown to contribute to physiological or pathophysiological processes. Studies are also beginning to unravel the structural basis of allosteric modulation of GPCRs. It remains to be determined whether such modulation represents interactions within monomers versus across dimers.
Nicotinic Acetylcholine Receptors and Nicotinic Cholinergic Mechanisms of the Central Nervous System
Authors: Dani John A. , Bertrand Daniel
Published: September 2006

Subtypes of neuronal nicotinic acetylcholine receptors (nAChRs) are constructed from numerous subunit combinations that compose channel-receptor complexes with varied functional and pharmacological characteristics. Structural and functional diversity and the broad presynaptic, postsynaptic, and nonsynaptic locations of nAChRs underlie their mainly modulatory roles throughout the mammalian brain. Presynaptic and preterminal nicotinic receptors enhance neurotransmitter release, postsynaptic nAChRs contribute a small minority of fast excitatory transmission, and nonsynaptic nAChRs modulate many neurotransmitter systems by influencing neuronal excitability. Nicotinic receptors have roles in development and synaptic plasticity, and nicotinic mechanisms participate in learning, memory, and attention. Decline, disruption, or alterations of nicotinic cholinergic mechanisms contribute to dysfunctions such as epilepsy, schizophrenia, Parkinson's disease, autism, dementia with Lewy bodies, Alzheimer's disease, and addiction.
Mucosal stimulation activates secretomotor neurons via long myenteric pathways in guinea pig ileum
Authors: Reed David E. , Vanner Stephen
Published: September 2006

This study examined whether mucosal stimulation activates long secretomotor neural reflexes and, if so, how they are organized. The submucosa of in vitro full thickness guinea pig ileal preparations was exposed in the distal portion and intracellular recordings were obtained from electrophysiologically identified secretomotor neurons. Axons in the intact mucosa of the oral segment were stimulated by a large bipolar stimulating electrode. In control preparations, a single stimulus pulse evoked a fast excitatory postsynaptic potential (EPSP) in 86% of neurons located 0.7–1.0 cm anal to the stimulus site. A stimulus train evoked multiple fast EPSPs, but slow EPSPs were not observed. To examine whether mucosal stimulation specifically activated mucosal sensory nerve terminals, the mucosa/submucosa was severed from the underlying layers and repositioned. In these preparations, fast EPSPs could not be elicited in 89% of cells. Superfusion with phorbol dibutyrate enhanced excitability of sensory neurons and pressure-pulse application of serotonin to the mucosa increased the fast EPSPs evoked by mucosal stimulation, providing further evidence that sensory neurons were involved. To determine whether these reflexes projected through the myenteric plexus, this plexus was surgically lesioned between the stimulus site and the impaled neuron. No fast EPSPs were recorded in these preparations following mucosal stimulation whereas lesioning the submucosal plexus had no effect. These results demonstrate that mucosal stimulation triggers a long myenteric pathway that activates submucosal secretomotor neurons. This pathway projects in parallel with motor and vasodilator reflexes, and this common pathway may enable coordination of intestinal secretion, blood flow, and motility.
Evaluation of transmural distribution of viable muscle by myocardial strain profile and dobutamine stress echocardiography
Authors: Maruo Takeshi , Nakatani Satoshi , Jin Yintie , Uemura Kazunori , Sugimachi Masaru , Ueda-Ishibashi Hatsue , Kitakaze Masafumi , Ohe Tohru , Sunagawa Kenji , Miyatake Kunio
Published: September 2006

Transmural distribution of viable myocardium in the ischemic myocardium has not been quantified and fully elucidated. To address this issue, we evaluated transmural myocardial strain profile (TMSP) in dogs with myocardial infarction using a newly developed tissue strain imaging. TMSP was obtained from the posterior wall at the epicardial left ventricular short-axis view in 13 anesthetized open-chest dogs. After control measurements, the left circumflex coronary artery was occluded for 90 min to induce subendocardial infarction (SMI). Subsequently, latex microbeads (90 μm) were injected in the same artery to create transmural infarction (TMI). In each stage, measurements were done before and after dobutamine challenge (10 μg·kg−1·min−1 for 10 min) to estimate transmural myocardial viability. Strain in the subendocardium in the control stage increased by dobutamine (from 53.6 ± 17.1 to 73.3 ± 21.8%, P < 0.001), whereas that in SMI and TMI stages was almost zero at baseline and did not increase significantly by dobutamine [from 0.8 ± 8.8 to 1.3 ± 7.0%, P = not significant (NS) for SMI, from −3.9 ± 5.6 to −1.9 ± 6.0%, P = NS for TMI]. Strain in the subepicardium increased by dobutamine in the control stage (from 23.9 ± 6.1 to 26.3 ± 6.4%, P < 0.05) and in the SMI stage (from 12.4 ± 7.3 to 27.1 ± 8.8%, P < 0.005), whereas that in the TMI stage did not change (from −1.0 ± 7.8 to −0.7 ± 8.3%, P = NS). In SMI, the subendocardial contraction was lost, but the subepicardium showed a significant increase in contraction with dobutamine. However, in TMI, even the subepicardial increase was not seen. Assessment of transmural strain profile using tissue strain imaging was a new and useful method to estimate transmural distribution of the viable myocardium in myocardial infarction.
The impact of hypoxia on in vivo glucose uptake in a hypoglycemic fish,Myoxocephalus scorpius
Authors: MacCormack Tyson J. , Driedzic William R.
Published: September 2006

The mechanisms controlling carbohydrate utilization in teleost fish are poorly understood, particularly in the heart. Tissue glucose uptake and cardiovascular characteristics were measured in the short-horned sculpin, Myoxocephalus scorpius, a species exhibiting low blood glucose levels, during normoxia and hypoxia to assess the role of adenosine receptors in the control of glucose uptake and anaerobic metabolism. As expected, hypoxia exposure (300 min at 2 mg/l dissolved oxygen) resulted in a bradycardia and plasma lactate accumulation, but glucose uptake rates did not change in heart, brain, gill, spleen, and white muscle. Plasma glucose-to-intracellular glucose ratios indicated that glucose uptake was the rate-limiting step in glucose utilization. The majority of intracellular glucose was unphosphorylated, however, suggesting that hexokinase is also important in controlling the tissue glucose gradient. During hypoxia, the cholinergic blocker atropine resulted in tachycardia but did not significantly change tissue glucose uptake rates or heart and brain adenosine levels. In contrast, the combined treatment of atropine and an adenosine receptor blocker [8-( p-sulfophenyl)theophylline] during hypoxia increased heart glucose uptake to levels fivefold higher than normoxic fish, with no additive effects on cardiovascular parameters. Significant tissue lactate accumulation was observed in this group of fish, signifying that adenosine receptors may depress anaerobic metabolism, even though tissue adenosine accumulation was absent during hypoxia. White muscle accumulated glucose during normoxia, suggesting the presence of gluconeogenic pathways or active uptake mechanisms not previously described in this tissue.
Denervation does not change the ratio of collagen I and collagen III mRNA in the extracellular matrix of muscle
Authors: Arruda Ellen M. , Mundy Kevin , Calve Sarah , Baar Keith
Published: September 2006

Denervation or inactivity is known to decrease the mass and alter the phenotype of muscle and the mechanics of tendon. It has been proposed that a shift in the collagen of the extracellular matrix (ECM) of the muscle, increasing type III and decreasing type I collagen, may be partially responsible for the observed changes. We directly investigated this hypothesis using quantitative real-time PCR on muscles and tendons that had been denervated for 5 wk. Five weeks of denervation resulted in a 2.91-fold increase in collagen concentration but no change in the content of collagen in the muscle, whereas in the tendon there was no change in either the concentration or content of collagen. The expression of collagen I, collagen III, and lysyl oxidase mRNA in the ECM of muscle decreased (76 ± 1.6%, 73 ± 2.3%, and 83 ± 3.2%, respectively) after 5 wk of denervation. Staining with picrosirius red confirmed the earlier observation of a change in staining color from red to green. Taken with the observed equivalent decreases in collagen I and III mRNA, this suggests that there was a change in orientation of the ECM of muscle becoming more aligned with the axis of the muscle fibers and no change in collagen type. The change in collagen orientation may serve to protect the smaller muscle fibers from damage by increasing the stiffness of the ECM and may partly explain why the region of the tendon closest to the muscle becomes stiffer after inactivity.