bluuebunny/crossref_metadata_2025 huggingface dataset:
Traumatic intrusion of maxillary permanent incisors into the nasal cavity: report of a case
Authors: Luna Aníbal Henrique Barbosa , Moreira Roger William Fernandes , Moraes Márcio de
Published: March 2008

Abstract –  Complete intrusion injuries in the mixed or permanent dentition are relatively rare and represent one of the most serious injuries to the periodontal ligament in dental traumatology. This paper describes the case history of a 7‐year‐old boy who sustained displacement of central incisors into the nasal cavity. Surgical repositioning was undertaken and a splint was placed.
Tooth fragment reattachment in multiple complicated permanent incisor crown‐root fractures – a report of two cases
Authors: Naudi Antoniella Busuttil , Fung Diane E.
Published: March 2008

Abstract –  Crown‐root fractures account for only 5% of all traumatic injuries; however, they can present difficulties for successful management. This paper describes the treatment of two unrelated children who sustained crown‐root fractures, extending subgingivally, in permanent upper central incisor teeth with immature apices.
Reattachment using a fragment from an extracted tooth to treat complicated coronal fracture
Authors: Demarco Flávio Fernando , De Moura Flávio Renato Reis , Tarquinio Sandra Beatriz Chaves , Lima Fábio Garcia
Published: March 2008

Abstract –  Reattachment of fragment is the preferred alternative to restore the fractured teeth, offering several advantages. Partial pulpotomy has demonstrated satisfactory results as a conservative treatment for pulp exposures because of trauma. This study reports a case in which the treatment of a complicated coronal fracture was accomplished by partial pulpotomy and reattachment of a dental fragment obtained from an extracted tooth using composite resin. The results show the feasibility of the conservative pulp therapy and the restorative approach.
Repair of a horizontal mid‐root fracture accompanied by labial luxation and partial alveolar fracture: a 21‐year follow up
Authors: Zabalegui‐Andonegui Borja , Tabernero‐Gallimó Inmaculada
Published: March 2008

Abstract –  The prognosis of injured teeth involving horizontal mid‐root fractures is poor and depends heavily on pulpal vitality, periodontal health and the repositioning of the tooth to its original position. Here, we report the case of an upper right central incisor presenting a horizontal mid‐root fracture, complicated by impaction of the coronal fragment in the external alveolar bone, which in turn prevented the repositioning of the tooth fragment. As a consequence, it was necessary to raise a full‐thickness flap and perform window‐osteotomy to free the coronal fragment and reset the fractured fragment. Short‐term follow up revealed pulpal vitality of the affected incisor and tissue repair at the level of the line of fracture, without any signs of periapical or periradicular pathology. In this paper, we describe some of the clinical features found upon revising this case 21 years later. The affected tissues are in good health, the root fracture is repaired and the pulp maintains its vitality.
Effectiveness of dental trauma education for elementary school staff
Authors: McIntyre Judy D. , Lee Jessica Y. , Trope Martin , Vann William F.
Published: March 2008

Abstract –  The purpose of this study was to assess the knowledge of elementary school staff members regarding the management of traumatic dental injuries (TDI) before and after an educational intervention aimed to increase TDI knowledge. Using a newly developed reliable survey instrument, we tested our elementary school staff participants about TDI before (time0), immediately after (time1), and three months after (time2) the intervention. Schools were randomized into three groups: no intervention/control (C), pamphlets (P), and pamphlets + lecture (P + L). Outcomes of interest were TDI knowledge over time relative to the interventions vs controls. Statistical analysis involved a repeated measures linear model. At time0, TDI knowledge was low among all three groups. At time1, knowledge increased among all groups and is given by P > P+L > C. For time2 vs time1, the P + L group retained the knowledge while in both the C and P groups the knowledge level decreased. Between time1 and time2, significant differences were found between both intervention groups when compared with the control (P vs C and P + L vs C: both P < 0.05). In summary, both P and P + L groups significantly improved TDI knowledge among elementary school staff, and this difference held up over time. These interventions have the potential to improve TDI management by elementary school staff when faced with such injuries.
Tooth avulsion in children: to replant or not
Authors: ANDREASEN JENS OVE , MALMGREN BARBRO , BAKLAND LEIF K.
Published: March 2008

Replanting avulsed teeth with a doubtful long‐term prognosis due to unfavorable extra‐alveolar conditions has recently been questioned by Kenny and Barrett (1). Many factors, however, still favor replanting such teeth. First of all, reliability of failure predictors has not yet been tested in prospective studies. Secondly, preservation of even resorbing replanted teeth may offer significant long‐term advantages in preparation for definitive treatment. Also, for psychological reasons, replantation can significantly reduce the anxiety and despair of both the injured child and the parents. Furthermore, decoronation of a resorbing anterior tooth will allow it to serve as a matrix for alveolar bone formation and preserve an otherwise resorbing alveolar process, thereby leaving an environment of bone and soft tissue that is optimal for both single implant insertion or fixed prosthesis. Finally, replantation and subsequent decoronation, if indicated, appears to be cost‐effective in comparison with non‐replantation combined with subsequent repeated prosthetic tooth replacements owing to vertical alveolar growth of adjacent ridge areas, with eventual definitive implant placement or a fixed prosthesis.
Alveolar bone development after decoronation of ankylosed teeth
Authors: MALMGREN BARBRO , MALMGREN OLLE , ANDREASEN JENS OVE
Published: March 2008

Decoronation of ankylosed teeth in infraposition was introduced in 1984 by Malmgren and co‐workers (1). This method is used all over the world today. It has been clinically shown that the procedure preserves the alveolar width and rebuilds lost vertical bone of the alveolar ridge in growing individuals. The biological explanation is that the decoronated root serves as a matrix for new bone development during resorption of the root and that the lost vertical alveolar bone is rebuilt during eruption of adjacent teeth. First a new periosteum is formed over the decoronated root, allowing vertical alveolar growth. Then the interdental fibers that have been severed by the decoronation procedure are reorganized between adjacent teeth. The continued eruption of these teeth mediates marginal bone apposition via the dental‐periosteal fiber complex. The erupting teeth are linked with the periosteum covering the top of the alveolar socket and indirectly via the alveolar gingival fibers, which are inserted in the alveolar crest and in the lamina propria of the interdental papilla. Both structures can generate a traction force resulting in bone apposition on top of the alveolar crest. This theoretical biological explanation is based on known anatomical features, known eruption processes and clinical observations.
Relationship between calcium hydroxide pH levels in the root canals and periodontal healing after replantation of avulsed teeth
Authors: ANDREASEN JENS OVE , JENSEN LILLI , CHRISTENSEN SØREN STENO AHRENSBURG
Published: March 2008

Calcium hydroxide [Ca(OH)2], when used as a root canal dressing, has been shown to promote periapical healing, induce formation of an apical hard tissue barrier (apexification), and arrest infection‐related root resorption. The main mechanism of action is thought to be the high alkalinity of Ca(OH)2 ensuring a bactericidal or bacteriostatic effect upon microorganisms in the root canal and dentinal tubules. Several anatomical factors related to the root canal, such as the coronal access cavity, the apical foramen, the dentinal tubules, and existing resorption cavities on the root surface, all allow leakage of hydroxide ions from the root canal. The purpose of the present clinical study was to analyze pH changes in 63 permanent anterior teeth in which Ca(OH)2 (Calasept®) was used as an initial canal dressing after replantation and subsequent pulp necrosis had developed. The pH changes in the pulp canal were studied with relation to observation period, stage of root formation, healing of any periapical radiolucency, infection‐related root resorption, formation of an apical hard tissue barrier, and finally the radiographic appearance of Ca(OH)2 in the canal (i.e. present or not). The study showed that several factors determined the pH level: the observation period (i.e. observation periods exceeding 6 months showed a significant drop in pH level below a pH of 10), an initial active inflammatory root resorption (tendency to be related to a drop in pH), and a subsequent progression of infection‐related resorption (the same tendency to be related to a drop in pH to below 10). The size of the apical foramen and the length of the pulp had no relation to pH change. The radiographic disappearance of Ca(OH)2 in the root canal (loss of radiopacity of the canal dressing) was found to be significantly associated with a drop in pH (P=0.001). It was concluded that radiographic monitoring of the Ca(OH)2 presence in the root canal is essential for endodontic treatment planning (i.e. when to replace Ca(OH)2 or perform a permanent root filling). Furthermore, continuous activity of inflammatory root resorption may indicate a drop in pH and should result in replacement of new Ca(OH)2. It should be noted that these findings apply to a Ca(OH)2 product (Calasept®) with no added radiopaque material.
Neuronal cell adhesion molecule deletion induces a cognitive and behavioral phenotype reflective of impulsivity
Authors: Matzel L. D. , Babiarz J. , Townsend D. A. , Grossman H. C. , Grumet M.
Published: March 2008

Cell adhesion molecules, such as neuronal cell adhesion molecule (Nr‐CAM), mediate cell–cell interactions in both the developing and mature nervous system. Neuronal cell adhesion molecule is believed to play a critical role in cell adhesion and migration, axonal growth, guidance, target recognition and synapse formation. Here, wild‐type, heterozygous and Nr‐CAM null mice were assessed on a battery of five learning tasks (Lashley maze, odor discrimination, passive avoidance, spatial water maze and fear conditioning) previously developed to characterize the general learning abilities of laboratory mice. Additionally, all animals were tested on 10 measures of sensory/motor function, emotionality and stress reactivity. We report that the Nr‐CAM deletion had no impact on four of the learning tasks (fear conditioning, spatial water maze, Lashley maze and odor discrimination). However, Nr‐CAM null mice exhibited impaired performance on a task that required animals to suppress movement (passive avoidance). Although Nr‐CAM mutants expressed normal levels of general activity and body weights, they did exhibit an increased propensity to enter stressful areas of novel environments (the center of an open field and the lighted side of a dark/light box), exhibited higher sensitivity to pain (hot plate) and were more sensitive to the aversive effects of foot shock (shock‐induced freezing). This behavioral phenotype suggests that Nr‐CAM does not play a central role in the regulation of general cognitive abilities but may have a critical function in regulating impulsivity and possibly an animal’s susceptibility to drug abuse and addiction.
Mapping a locus for alcohol physical dependence and associated withdrawal to a 1.1 Mb interval of mouse chromosome 1 syntenic with human chromosome 1q23.2‐23.3
Authors: Kozell L. , Belknap J. K. , Hofstetter J. R. , Mayeda A. , Buck K. J.
Published: March 2008

Physiological dependence and associated withdrawal episodes are thought to constitute a motivational force perpetuating continued alcohol use/abuse. Although no animal model duplicates alcoholism, models for specific factors, like the withdrawal syndrome, are useful to identify potential determinants of liability in humans. We previously detected quantitative trait loci (QTLs) with large effects on predisposition to physical dependence and associated withdrawal following chronic or acute alcohol exposure to a large region of chromosome 1 in mice (Alcdp1 and Alcw1, respectively). Here, we provide the first confirmation of Alcw1 in a congenic strain, and, using interval‐specific congenic strains, narrow its position to a minimal 1.1 Mb (maximal 1.7 Mb) interval syntenic with human chromosome 1q23.2‐23.3. We also report the development of a small donor segment congenic that confirms capture of a gene(s) affecting physical dependence after chronic alcohol exposure within this small interval. This congenic will be invaluable for determining whether this interval harbors a gene(s) involved in additional alcohol responses for which QTLs have been detected on distal chromosome 1, including alcohol consumption, alcohol‐conditioned aversion and ‐induced ataxia. The possibility that this QTL plays an important role in such diverse responses to alcohol makes it an important target. Moreover, human studies have identified markers on chromosome 1q associated with alcoholism, although this association is still suggestive and mapped to a large region. Thus, the fine mapping of this QTL and analyses of the genes within the QTL interval can inform developing models for genetic determinants of alcohol dependence in humans.
A magnetic resonance spectroscopy study of antisocial behaviour disorder, psychopathy and violent crime among military conscripts
Authors: Basoglu Cengiz , Semiz Umit , Oner Ozgur , Gunay Huseyin , Ebrinc Servet , Cetin Mesut , Sildiroglu Onur , Algul Ayhan , Ates Alpay , Sonmez Guner
Published: March 2008

Background:

Prefrontal and/or temporo-limbic abnormalities associated with antisocial personality disorder (APD), high psychopathy scores and violent behaviours can readily be evaluated by neuroimaging methods.

Objectives:

In this study, we compared the brain metabolites in adult male military conscripts with APD, high psychopathy scores and serious violent crimes (n = 15) with age- and educational-level-matched healthy controls (n = 15) by means of magnetic resonance spectroscopy.

Methods:

All cases were diagnosed by means of the Diagnostic Statistical Manual-IV APD module of the Structured Clinical Interview for DSM III-R Axis II Disorders (SCID-II) semistructured questionnaire in Turkish. The psychopathy scores were evaluated by means of the Hare Psychopathy Checklist-Revised translated into Turkish (PCL-R). PCL-R is a 20-item, reliable and valid instrument for assessment of psychopathy, both in categorical and dimensional natures. All patients had a total score of 29 (of possible 40) or higher from PCL-R, indicating a high degree of psychopathy.

Results:

Our results showed no significant differences in ratio of N-acetyl aspartate (NAA), creatine (Cr) and choline-related compounds in the right dorsolateral prefrontal cortex, anterior cingulate cortex (ACC) and amygdala–hippocampus regions of cases compared with controls. ACC NAA/Cr was significantly negatively correlated with both the PCL-R total score and the PCL-R factor I score (interpersonal/affective problems) among the cases.

Conclusion:

As ACC plays an important role in decision-making and emotional information processing, we postulate that the lower NAA/Cr ratio, suggesting impaired neural integrity, may increase the severity of interpersonal/affective problems of the psychopathy factor in male subjects exhibiting APD, high psychopathy overall scores and violent crimes.
Osteopenia of prematurity: a national survey and review of practice
Authors: Harrison CM , Johnson K , McKechnie E
Published: March 2008

Premature infants are at significant risk of reduced bone mineral content (BMC) and subsequent osteopenia. There are currently no standard practices regarding screening, investigation or treatment of this condition. We present a case report and findings of a national survey of 36 level 2 and 3 neonatal units (72% response rate). The findings showed widely disparate practice regarding screening, prevention and treatment. We summarize the tests currently available for osteopenia and suggest guidelines for management of the at risk group.

Conclusion: Our survey confirms inconsistent practices regarding management of infants at risk of osteopenia of prematurity. Investigations and treatments available are summarized together with a guideline for management of this susceptible group of infants.
Antifungal prophylaxis for the prevention of neonatal candidiasis?
Authors: O'Grady Michael J , Dempsey Eugene M
Published: March 2008

Background: Randomized controlled trials suggest that prophylactic administration of antifungal agents reduce the rate of colonization and invasive Candida infection in a subgroup of high‐risk very low birth weight (VLBW) neonates. The extent of antifungal prophylaxis use in the United Kingdom and Ireland is unknown.

Methods: A postal questionnaire was administered to neonatologists practicing in the United Kingdom and Ireland caring for VLBW infants. Information was requested on the prophylactic agents used, dosing schedules and duration of therapy. The rationale for reported practices was also ascertained.

Results: The response rate was 55% (125/228). Antifungal prophylaxis use was reported by 66 (53%) respondents. First‐line agents utilized included oral nystatin (53%) and intravenous fluconazole (41%). The most frequent indications for antifungal prophylaxis included antibiotic administration in 45 (68%) and decreased birth weight in 33 (50%) respondents. The majority of respondents who did not use antifungal prophylaxis felt that the perceived rate of invasive fungal disease within their unit was not high enough to justify its use.

Conclusions: A small majority of clinicians caring for VLBW neonates routinely use antifungal prophylaxis. This reflects the wide variation in the incidence of invasive disease, lack of guidelines supporting a role for prophylaxis and concerns related to emergence of resistant strains.
Preterm birth and carotid diameter and stiffness in childhood
Authors: Bonamy Anna‐Karin Edstedt , Andolf Ellika , Martin Helena , Norman Mikael
Published: March 2008

Background and Aim: Low birthweight, either as a result of poor foetal growth or preterm birth, is a risk factor for stroke in adult life. Carotid stiffening, an early marker of atheromatous disease, has been found in low‐birthweight children born at term. We hypothesized that carotid artery growth and dynamic properties are permanently affected by preterm birth.

Methods: Carotid artery stiffness and dimensions in 56 school children, 39 born very preterm (mean gestational age [GA] 29 weeks) and 17 controls born at term, were studied by ultrasonic measurements of the pulsatile movements of the vessel wall.

Results: The carotid artery diameter was 6.4 mm both in children born preterm and at term (p = 0.99). No difference in carotid stiffness was found. Within the preterm group, no differences could be seen between those born small for gestational age (SGA) or appropriate for gestational age (AGA).

Conclusions: Carotid artery elasticity and structure are not altered after preterm birth. The mechanisms behind the increased stroke risk in adults born preterm remain unresolved.
Prevalence and risk factors of asthma and allergic diseases among schoolchildren in Bolu, Turkey
Authors: Talay Fahrettin , Kurt Bahar , Tug Tuncer , Yilmaz Fahrettin , Goksugur Nadir
Published: March 2008

Aim: In this study we aimed to detect the prevalence and risk factors of asthma and allergic diseases in children aged between 7 and 14 years old at rural and urban areas of Bolu, Turkey.

Methods: Questionnaire of International Study of Asthma and Allergies in Childhood (ISAAC) phase one and questionnaire including questions about family, demographic, socio‐economic characteristics of children were applied to 931 schoolchildren who were selected by randomized sampling.

Results: In children, the prevalence of diseases and symptoms were as follows: wheeze ever: 15.5%, asthma: 5.6%, nasal symptoms ever: 41.4%, allergic rhinitis: 23.2%, itchy rash ever: 5.9% and eczema: 5.0%. In multivariate regression analysis, presence of allergic disease in the family was risk factor for wheezing (OR = 1.74, 95% CI = 1.19–2.76), asthma (OR = 2.19, CI = 1.06–4.52), allergic rhinitis (OR = 2.68, CI = 1.80–3.98) and eczema (OR = 2.33, CI = 1.17–4.65); living in shanties was risk factor for allergic rhinitis (OR = 5.26, CI = 2.1–13.16); a monthly income below $300 was risk factor for asthma (OR = 2.54, CI = 1.06–6.08).

Conclusion: It was detected that the prevalence of allergic rhinitis and its symptoms was more common in schoolchildren living in Bolu. Presence of allergic disease in fathers or mothers and low socio‐economic level increase the risk of asthma and other allergic diseases in children.
Ethics ain't easy: do we need simple rules for complicated ethical decisions?
Authors: Janvier Annie , Barrington Keith J. , Aziz Khalid , Lantos John
Published: March 2008

Background: Recommendations from national bodies regarding extremely preterm infants have focussed almost exclusively on thresholds for intervention based upon estimated gestational age (GA) alone.

Methods: We reviewed policy statements that address active intervention for newborn infants and compare them with those that are available for older patients. We reviewed research, examining attitudes towards preterm infants, uncertainties in GA assessment and other factors important in determining prognosis at the time of birth.

Results: Policy statements regarding active care of very preterm infants treat this population differently from others in morally significant ways – without rationalizing this discrepancy. Extremely preterm infants are devalued in medical and lay opinion compared to older individuals with similar outcomes. Uncertainty in GA estimates often covers a range with vastly differing prognoses. Sex, birth weight, inborn‐outborn status and use of antenatal steroids are vitally important in prognosis, but clinical findings in the delivery room are not. Most policy statements fail to account for these factors.

Conclusion: Simplistic policies based on GA alone should be avoided. Decision making for extremely preterm infants should recognize that they are each unique and must be individualized, taking into account all relevant prognostic factors and the values and wishes of the families.
Variations in Kinship Networks Across Geographic and Social Space
Authors: Murphy Michael
Published: March 2008

This article analyzes variations in interaction with non‐coresident adult kin based on comparable cross‐national surveys conducted in 2001 in 27 countries. The two main dimensions of kin contact are considered: (1) overall levels and (2) the relative emphasis given to contacts with primary kin (parents, adult children, siblings) and secondary kin (aunts, cousins, in‐laws). Age‐adjusted variations in kin contact between countries are much greater than those within countries. These results do not confirm the commonly hypothesized existence of well‐defined family system boundaries in Europe arising from historical factors. The similarity of patterns of countries outside Europe with European countries with which they have historical ties suggests cultural factors are important in explaining interaction with kin, whereas welfare regimes appear to have little explanatory value. Within Europe, kin contact levels are more strongly related to a north/south divide than to indicators of economic development or religiosity. The findings suggest that neither of the extreme assumptions—homogenizing pressures toward a nuclear family model or persistent well‐defined groupings arising from historical contexts—can be substantiated. Rather, there is a continuum in family behaviors over a substantial range, related to a number of explanatory factors.
The Contribution of Assisted Reproduction to Completed Fertility: An Analysis of Danish Data
Authors: Sobotka Tomáŝ , Hansen Martin A. , Jensen Tina Kold , Pedersen Anette Tønnes , Lutz Wolfgang , Skakkebæk Niels Erik
Published: March 2008

Assisted reproduction has a minor but increasing influence on childbearing trends in advanced societies. In Denmark, the use of assisted reproduction technology (ART) has become particularly widespread. At the same time, Danish women born in the late 1950s and the 1960s experienced stabilization or even a slight increase in their mean number of children. Broad availability and widespread use of assisted reproduction may become important factors contributing to maintaining relatively high completed fertility among the younger cohorts of Danish women. To explore this idea, we analyze and project cohort trends in fertility rates among native Danish women born in 1960‐78 and examine the likely contribution of assisted reproduction to these trends. The projected proportion of children born after ART treatment shows a substantial increase from 2.1 percent among women born in 1965 to 4‐5 percent among women born in 1978, with an estimated net impact of ART (as compared with the hypothetical situation where no ART treatment was available) on the order of 3‐4 percent. When intrauterine inseminations are included, this implies that up to 7 percent of children of those native Danish women born in 1975 and later will likely be conceived by infertility treatment.
A Profile of the World's Young Developing Country International Migrants
Authors: McKenzie David J.
Published: March 2008

Individual‐level census and household survey data are used to present a rich profile of young developing country international migrants around the world. They are found to comprise a large share of the flow of migrants, particularly among migrants to other developing countries, with the age distribution of migrants peaking in the late teens or early twenties. Detailed data are presented on the age and sex composition of migrants, on whether young migrants move alone or with a parent or spouse, on their participation in schooling and work in the destination country, on the types of jobs they have, and on the incidence and age of return migration. The results suggest a high degree of commonality in the youth immigrant experience across a number of destination countries. Recent developing country young migrants tend to work in similar occupations and are more concentrated in these occupations than recent older migrants or young immigrants who arrived at an earlier age. Nevertheless, there is also considerable heterogeneity among young immigrants with respect to school attendance and work in their destination country. The potential of international migration for building human capital is significant but far from being fully used.
European Demographic Forecasts Have Not Become More Accurate Over the Past 25 Years
Authors: Keilman Nico
Published: March 2008

Nowadays, demographers, population statisticians, and population forecasters have richer data, more refined theories of demographic behavior, and more sophisticated methods of analysis than they had two or three decades ago. This scientific progress should have made it easier to predict demographic behavior. But analyses of the errors in older forecasts show that demographic forecasts published by statistical agencies in 14 European countries have not become more accurate over the past 25 years. The findings demonstrate that scientific progress in population studies during the previous two to three decades has not kept up with the trend toward less predictable demographic behavior of populations in European countries. There is no reason to be more optimistic about US Census Bureau forecasts. Population forecasts are intrinsically uncertain, hence should be couched in probabilistic terms.
An intermediate step in the evolution of ATPases – a hybrid F0–V0 rotor in a bacterial Na+ F1F0 ATP synthase
Authors: Fritz Michael , Klyszejko Adriana L. , Morgner Nina , Vonck Janet , Brutschy Bernd , Muller Daniel J. , Meier Thomas , Müller Volker
Published: March 2008

The Na+ F1F0 ATP synthase operon of the anaerobic, acetogenic bacterium Acetobacterium woodii is unique because it encodes two types of c subunits, two identical 8 kDa bacterial F0‐like c subunits (c2 and c3), with two transmembrane helices, and a 18 kDa eukaryal V0‐like (c1) c subunit, with four transmembrane helices but only one binding site. To determine whether both types of rotor subunits are present in the same c ring, we have isolated and studied the composition of the c ring. High‐resolution atomic force microscopy of 2D crystals revealed 11 domains, each corresponding to two transmembrane helices. A projection map derived from electron micrographs, calculated to 5 Å resolution, revealed that each c ring contains two concentric, slightly staggered, packed rings, each composed of 11 densities, representing 22 transmembrane helices. The inner and outer diameters of the rings, measured at the density borders, are approximately 17 and 50 Å. Mass determination by laser‐induced liquid beam ion desorption provided evidence that the c rings contain both types of c subunits. The stoichiometry for c2/c3 : c1 was 9 : 1. Furthermore, this stoichiometry was independent of the carbon source of the growth medium. These analyses clearly demonstrate, for the first time, an F0–V0 hybrid motor in an ATP synthase.
Identification and Validation of a New Nursing Diagnosis: Sick Role Conflict
Authors: Kubsch Sylvia M. , Wichowski Harriet Conley
Published: March 2008

The purpose of this research is to assess the presence, etiology, and effects of sick role conflict experienced by hospitalized patients. Data from 99 hospitalized adult subjects were analyzed using a path analysis design. Patients were interviewed at the bedside using a structured interview tool developed by the researchers. It was found that subjects who occupied multiple roles, who were not adequately prepared for hospitalization, and who had an acute rather than chronic illness were prone to experience sick role conflict when hospitalized. Those subjects experiencing sick role conflict did not fully assume the sick role as defined by Parsons (1956). As a consequence of incomplete sick role assumption, an increased incidence of human responses such as guilt, powerless ness, anxiety, decreased self‐esteem, depression, appetite change, and insomnia were reported. The researchers urge nurses to assume responsibility for diagnosing and treating sick role conflict, a human response lo hospitalization commonly seen among patients.
Metacognitive Skills in Diagnostic Reasoning: Making the Implicit Explicit
Authors: Pesut Daniel J. , Herman JoAnne
Published: March 2008

The metacognitive skills or monitoring, analyzing, predicting, planning, evaluating, regulating, and revising frame the nursing process and support clinical reasoning. Nurse educators who encourage metacognitive skill acquisition are likely to accelerate student comprehension, understanding, and mastery or nursing diagnosis, nursing process, and clinical reasoning. The models presented in this article have implications for teaching and learning clinical/ diagnostic reasoning.
Nesting Success of Costa Rican Lowland Rain Forest Birds in Response to Edge and Isolation Effects
Authors: Young Bruce E. , Sherry Thomas W. , Sigel Bryan J. , Woltmann Stefan
Published: March 2008

Although open‐cup nesting birds generally face increased risk of nest depredation from forest edge predators and brood parasites in fragmented temperate landscapes, little information exists to assess such risks in tropical birds. We compared nesting success of real birds' nests in large and small forest fragments to a control site in Caribbean lowland wet forest of Costa Rica. Pooling across species, nesting success was significantly greater in unfragmented forest than in either small, isolated fragments or the La Selva Biological Reserve, which is at the tip of a forest ‘peninsula’ embedded in a largely deforested landscape. Nesting success in isolated fragments did not vary according to distance from edge, suggesting that predators in fragments act throughout these forest patches. The case for increased nest predation as a plausible mechanism to explain the documented decline of forest interior bird populations in this fragmented tropical landscape is enhanced by a simple demographic model that suggests nesting success is likely too low to maintain populations at La Selva and in the fragments. The fact that the large (> 1000 ha) La Selva forest reserve is experiencing nest predation rates similar to those in much smaller fragments is cause for concern. Our results make a strong case for additional studies to document the identities of nest predators in both fragmented and unfragmented forests in such tropical forest landscapes.
Influence of Drought and Shade on Seedling Growth of Native and Invasive Trees in the Seychelles
Authors: Schumacher Eva , Kueffer Christoph , Tobler Monika , Gmür Veronika , Edwards Peter J. , Dietz Hansjörg
Published: March 2008

We studied the growth of seedlings of native and invasive tree species from secondary tropical forests on Mahé (Seychelles). We were interested in whether native or invasive species are more drought‐tolerant, and therefore conducted a garden (pot) experiment comparing the growth of seedlings of five native and five invasive tree species under different light (7% and 60% transmittance) and water (natural and repeated drought stress) conditions. Differences in the responses of native and invasive species to these treatments were small. In both groups, mean relative growth rates were reduced only slightly by intermittent drought that caused wilting of leaves. However, invasive species produced clearly thinner leaves (high specific leaf area, SLA) and more root biomass than native species under high light, while these differences were small under low light. Native species performed better than invasive species under low light with low water availability. It appears that high phenotypic plasticity allows some fast‐growing invasive species to cope with water stress by adjusting the relative allocation of resources to aboveground and belowground structures under high light, while this strategy is not effective when both light and water resources are limiting. We conclude that water stress may reduce the invasibility of shaded habitats by fast‐growing invasive species, while water stress in unshaded habitats may have less effect on invasive species than previously recognized.
Detecting Altitudinal Migration Events in Neotropical Birds Using Stable Isotopes
Authors: Fraser Kevin C. , Kurt Kyser T. , Ratcliffe Laurene M.
Published: March 2008

We evaluated the utility of stable‐hydrogen isotope ratios in tropical bird tissues for detecting altitudinal migration events. Our results identified two of five species as altitudinal migrants in Nicaragua. This approach may circumvent the current limitations of mark–recapture techniques and enhance our ability to study this poorly characterized behavior.
Root‐fed Salicylic Acid in Grape Involves the Response Caused by Aboveground High Temperature
Authors: Liu Hong‐Tao , Liu Yue‐Ping , Huang Wei‐Dong
Published: March 2008

In order to investigate the transportation and distribution of salicylic acid (SA) from root to aboveground tissues in response to high temperature, the roots of grape plant were fed with 14C‐SA before high temperature treatment. Radioactivity results showed that progressive increase in SA transportation from root to aboveground as compared with the control varied exactly with the heat treatment time. Radioactivity results of leaves at different stem heights indicated that the increase in SA amount at the top and middle leaves during the early period was most significant in comparison with the bottom leaves. The up‐transportation of SA from root to aboveground tissues was dependent on xylem rather than phloem. Auto‐radiographs of whole grape plants strongly approved the conclusions drawn above. Root‐derived SA was believed to be a fundamental source in response to aboveground high temperature.
Effects of Light on the Growth and Clonal Reproduction of Ligularia virgaurea
Authors: Wang Man‐Tang , Zhao Zhi‐Gang , Du Guo‐Zhen , He Yan‐Long
Published: March 2008

Ligularia virgaurea is a perennial herb that is widely distributed in the alpine meadow on the eastern Qinghai‐Tibet plateau. We investigated the patterns of growth and reproduction of L. virgaurea under two contrasting levels of light conditions for two continuous growing seasons. Our results showed that the light effects on the maximum relative growth rate, the shoot weight ratio and the root weight ratio differed between the two growing seasons. L. virgaurea reproduced initially through rhizome in the second growing season, rather than sexual reproduction. The proportion of genets with clonal reproduction decreased under shaded conditions. A minimum genet size should be attained for clonal reproduction to begin under the shaded conditions. There was a positive linear relationship between clonal reproduction and genet size. Light level affected the allocation of total biomass to clonal structures, with less allocation under the full natural irradiance than under the shaded conditions. There seemed to be a trade‐off between vegetative growth and clonal reproduction under the full natural irradiance, in terms of smaller relative growth rates of genets with clonal reproduction than those without clonal reproduction. L. virgaurea emphasized clonal reproduction under the full natural irradiance, while the plant emphasized vegetative growth under the shaded conditions.
Regional Self‐Employment: The Effect of State Push and Pull Factors
Authors: Benedict Mary Ellen , Hakobyan Irinah
Published: March 2008

This study investigates the effects of business cycle, tax, and self‐employment policy on the self‐employment rate at the state level. Using 1999‐2002 data, the results of the analysis suggest that the recession‐push hypothesis of self‐employment is not supported for the United States. In fact, it appears as though the prosperity‐pull hypothesis is a more likely candidate for explaining self‐employment and business cycle changes. Further, the Self‐Employment Assistance Program, based on the recession‐push hypothesis, appears to have a negative effect on the self‐employment rate. These results suggest that current programs to promote self‐employment have incorrectly focused on the unemployed, and/or have not prepared participants for self‐employment. The study also examines the tax effect on self‐employment and finds only weak support for the tax avoidance hypothesis.
The transition from pulpitis to periapical periodontitis in dogs’ teeth
Authors: Kovačević Maja , Tamarut Tomislav , Jonjić Nives , Braut Alen , Kovačević Miljenko
Published: March 2008

The purpose of the study was to histologically analyse transition from pulpitis to periapical periodontitis on dog's teeth. Pulps of mandibular premolars (37 roots) were exposed using a low‐speed handpiece. Teeth were left open to the oral environment for 20, 35, 50 and 65 days. After the experimental period animals were sacrificed. Undemineralised teeth with surrounding bone, embedded in methylmetacrylate, were prepared for standard histological analysis. All teeth with pulpitis (five roots), regardless of the experimental period, had acute serose periapical periodontitis. All teeth (15 roots) with partial pulp necrosis had subacute periapical periodontitis. Teeth with complete pulp necrosis (19 roots) had chronic periapical periodontitis and in one case suppurative apical periodontitis. The condition of the pulp correlates with the histopathological findings of periapical tissue in the open types of pulp infection. Acute periapical periodontitis begins during pulpitis and can occur before 20 days of pulp exposure in the dog.
Non‐surgical management of infected type III dens invaginatus with vital surrounding pulp using contemporary endodontic techniques
Authors: John Vijay
Published: March 2008

This paper reports on the conservative non‐surgical endodontic management of an upper right lateral incisor diagnosed with infected dens invaginatus (Oehlers’ type III) and associated acute apical abscess, while maintaining vitality of the surrounding pulp. The use of contemporary endodontic techniques in the diagnosis, treatment planning and management of the case is highlighted.
RESEARCH ARTICLE: Myelin Abnormalities without Oligodendrocyte Loss in Periventricular Leukomalacia
Authors: Billiards Saraid S. , Haynes Robin L. , Folkerth Rebecca D. , Borenstein Natalia S. , Trachtenberg Felicia L. , Rowitch David H. , Ligon Keith L. , Volpe Joseph J. , Kinney Hannah C.
Published: March 2008

The cellular basis of myelin deficits detected by neuroimaging in long‐term survivors of periventricular leukomalacia (PVL) is poorly understood. We tested the hypothesis that oligodendrocyte lineage (OL) cell density is reduced in PVL, thereby contributing to subsequent myelin deficits. Using computer‐based methods, we determined OL cell density in sections from 18 PVL and 18 age‐adjusted control cases, immunostained with the OL‐lineage marker Olig2. Myelination was assessed with myelin basic protein (MBP) immunostaining. We found no significant difference between PVL and control cases in Olig2 cell density in the periventricular or intragyral white matter. We did find, however, a significant increase in Olig2 cell density at the necrotic foci, compared with distant areas. Although no significant difference was found in the degree of MBP immunostaining, we observed qualitative abnormalities of MBP immunostaining in both the diffuse and necrotic components of PVL. Abnormal MBP immunostaining in PVL despite preserved Olig2 cell density may be secondary to arrested OL maturation, damage to OL processes, and/or impaired axonal‐OL signaling. OL migration toward the “core” of injury may occur to replenish OL cell number. This study provides new insight into the cellular basis of the myelin deficits observed in survivors of PVL.
RESEARCH ARTICLE: An Orthotopic Skull Base Model of Malignant Meningioma
Authors: Baia Gilson S. , Dinca Eduard B. , Ozawa Tomoko , Kimura Edna T. , McDermott Michael W. , James C. David , VandenBerg Scott R. , Lal Anita
Published: March 2008

Meningioma tumor growth involves the subarachnoid space that contains the cerebrospinal fluid. Modeling tumor growth in this microenvironment has been associated with widespread leptomeningeal dissemination, which is uncharacteristic of human meningiomas. Consequently, survival times and tumor properties are varied, limiting their utility in testing experimental therapies. We report the development and characterization of a reproducible orthotopic skull‐base meningioma model in athymic mice using the IOMM‐Lee cell line. Localized tumor growth was obtained by using optimal cell densities and matrigel as the implantation medium. Survival times were within a narrow range of 17–21 days. The xenografts grew locally compressing surrounding brain tissue. These tumors had histopathologic characteristics of anaplastic meningiomas including high cellularity, nuclear pleomorphism, cellular pattern loss, necrosis and conspicuous mitosis. Similar to human meningiomas, considerable invasion of the dura and skull and some invasion of adjacent brain along perivascular tracts were observed. The pattern of hypoxia was also similar to human malignant meningiomas. We use bioluminescent imaging to non‐invasively monitor the growth of the xenografts and determine the survival benefit from temozolomide treatment. Thus, we describe a malignant meningioma model system that will be useful for investigating the biology of meningiomas and for preclinical assessment of therapeutic agents.
RESEARCH ARTICLE: Neurogenesis Impairment and Increased Cell Death Reduce Total Neuron Number in the Hippocampal Region of Fetuses with Down Syndrome
Authors: Guidi Sandra , Bonasoni Paola , Ceccarelli Claudio , Santini Donatella , Gualtieri Fabio , Ciani Elisabetta , Bartesaghi Renata
Published: March 2008

We previously obtained evidence for reduced cell proliferation in the dentate gyrus (DG) of fetuses with Down syndrome (DS), suggesting that the hippocampal hypoplasia seen in adulthood may be caused by defective early neuron production. The goal of this study was to establish whether DS fetuses (17–21 weeks of gestation) exhibit reduction in total cell number in the DG, hippocampus and parahippocampal gyrus (PHG). Volumes of the cellular layers and cell number were estimated with Cavalieri's principle and the optical fractionator method, respectively. We found that in DS fetuses all investigated structures had a reduced volume and cell number. Analysis of cell phenotype showed that DS fetuses had a higher percentage of cells with astrocytic phenotype but a smaller percentage of cells with neuronal phenotype. Immunohistochemistry for Ki‐67, a marker of cycling cells, showed that DS fetuses had less proliferating cells in the germinal zones of the hippocampus and PHG. We additionally found that in the hippocampal region of DS fetuses there was a higher incidence of apoptotic cell death. Results show reduced neuron number in the DS hippocampal region and suggest that this defect is caused by disruption of neurogenesis and apoptosis, two fundamental processes underlying brain building.
SYMPOSIUM: Clearance of Aβ from the Brain in Alzheimer's Disease: Perivascular Drainage of Amyloid‐β Peptides from the Brain and Its Failure in Cerebral Amyloid Angiopathy and Alzheimer's Disease
Authors: Weller Roy O. , Subash Malavika , Preston Stephen D. , Mazanti Ingrid , Carare Roxana O.
Published: March 2008

Alzheimer's disease is the commonest dementia. One major characteristic of its pathology is accumulation of amyloid‐β (Aβ) as insoluble deposits in brain parenchyma and in blood vessel walls [cerebral amyloid angiopathy (CAA)]. The distribution of Aβ deposits in the basement membranes of cerebral capillaries and arteries corresponds to the perivascular drainage pathways by which interstitial fluid (ISF) and solutes are eliminated from the brain—effectively the lymphatic drainage of the brain. Theoretical models suggest that vessel pulsations supply the motive force for perivascular drainage of ISF and solutes. As arteries stiffen with age, the amplitude of pulsations is reduced and insoluble Aβ is deposited in ISF drainage pathways as CAA, thus, further impeding the drainage of soluble Aβ. Failure of perivascular drainage of Aβ and deposition of Aβ in the walls of arteries has two major consequences: (i) intracerebral hemorrhage associated with rupture of Aβ‐laden arteries in CAA; and (ii) Alzheimer's disease in which failure of elimination of ISF, Aβ and other soluble metabolites from the brain alters homeostasis and the neuronal environment resulting in cognitive decline and dementia. Therapeutic strategies that improve elimination of Aβ and other soluble metabolites from the brain may prevent cognitive decline in Alzheimer's disease.