bluuebunny/crossref_metadata_2025 huggingface dataset:
Reorganization of Remote Cortical Regions After Ischemic Brain Injury: A Potential Substrate for Stroke Recovery
Authors: Frost S. B. , Barbay S. , Friel K. M. , Plautz E. J. , Nudo R. J.
Published: May 2006

Although recent neurological research has shed light on the brain's mechanisms of self-repair after stroke, the role that intact tissue plays in recovery is still obscure. To explore these mechanisms further, we used microelectrode stimulation techniques to examine functional remodeling in cerebral cortex after an ischemic infarct in the hand representation of primary motor cortex in five adult squirrel monkeys. Hand preference and the motor skill of both hands were assessed periodically on a pellet retrieval task for 3 mo postinfarct. Initial postinfarct motor impairment of the contralateral hand was evident in each animal, followed by a gradual improvement in performance over 1–3 mo. Intracortical microstimulation mapping at 12 wk after infarct revealed substantial enlargements of the hand representation in a remote cortical area, the ventral premotor cortex. Increases ranged from 7.2 to 53.8% relative to the preinfarct ventral premotor hand area, with a mean increase of 36.0 ± 20.8%. This enlargement was proportional to the amount of hand representation destroyed in primary motor cortex. That is, greater sparing of the M1 hand area resulted in less expansion of the ventral premotor cortex hand area. These results suggest that neurophysiologic reorganization of remote cortical areas occurs in response to cortical injury and that the greater the damage to reciprocal intracortical pathways, the greater the plasticity in intact areas. Reorganization in intact tissue may provide a neural substrate for adaptive motor behavior and play a critical role in postinjury recovery of function.
Na+ Currents in Vestibular Type I and Type II Hair Cells of the Embryo and Adult Chicken
Authors: Masetto S. , Bosica M. , Correia M. J. , Ottersen O. P. , Zucca G. , Perin P. , Valli P.
Published: May 2006

In birds, type I and type II hair cells differentiate before birth. Here we describe that chick hair cells, from the semicircular canals, begin expressing a voltage-dependent Na current ( INa) from embryonic day 14 (E14) and continue to express the current up to hatching (E21). During this period, INa was present in most (31/43) type I hair cells irrespective of their position in the crista, in most type II hair cells located far from the planum semilunatum (48/63), but only occasionally in type II hair cells close to the planum semilunatum (2/35). INa activated close to –60 mV, showed fast time- and voltage-dependent activation and inactivation, and was completely, and reversibly, blocked by submicromolar concentrations of tetrodotoxin ( Kd = 17 nM). One peculiar property of INa concerns its steady-state inactivation, which is complete at –60 mV (half-inactivating voltage = –96 mV). INa was found in type I and type II hair cells from the adult chicken as well, where it had similar, although possibly not identical, properties and regional distribution. Current-clamp experiments showed that INa could contribute to the voltage response provided that the cell membrane was depolarized from holding potentials more negative than –80 mV. When recruited, INa produced a significant acceleration of the cell membrane depolarization, which occasionally elicited a large rapid depolarization followed by a rapid repolarization (action-potential-like response). Possible physiological roles for INa in the embryo and adult chicken are discussed.
Recent Clinical Trials of Surfactant Treatment for Neonates
Authors: Halliday Henry L.
Published: May 2006

Objective: To search for recent clinical trials of neonatal surfactant treatment and report their findings. Methods: Recent was defined as published between 2000 and 2005. An online search on PubMed was made on 30th December 2005 using the following terms: surfactant treatment, clinical trials and neonate, with limits of years 2000 to 2005 and age – newborn from birth to 1 month. Randomised clinical trials (RCTs) and systematic reviews of RCTs were prioritised and studies in children and animals were excluded from further analysis. Results: 175 papers were found in this search. Only about half of these papers were directly related to some aspect of surfactant treatment and of these just over one-half were either RCTs or systematic reviews of RCTs. Of the 34 RCTs of surfactant treatment, 3 were excluded as they involved children or animals rather than neonates. Twenty-nine trials studied preterm babies with respiratory distress syndrome (RDS) and 2 were for meconium aspiration syndrome (MAS) in term infants. The median sample sizes of these studies were RDS (92, range 19–1,361) and MAS (42, range 22–61). Eighteen of the RDS trials compared two or more surfactant preparations, the most frequently studied being Curosurf and Survanta but altogether 11 different surfactants were compared. These new RCTs need to be analysed by meta-analyses in systematic reviews. Twelve systematic reviews were found and these demonstrated the superiority of prophylactic over selective use of surfactant in babies <30 weeks, natural over synthetic surfactant and the absence of an increase in long-term developmental sequelae. Surfactant for MAS may reduce the severity of respiratory illness and the need for extracorporeal membrane oxygenation. Of the non-randomised trials’ novel delivery methods, failure to use evidence-based guidelines and the benefit of surfactant for babies <25 weeks were the most interesting. Conclusions: Surfactant remains one of the most effective and safest interventions in neonatology. Prophylactic natural surfactant seems to be the most evidence-based treatment for babies <30 weeks. Of the newer synthetic surfactants, only Surfaxin has been compared with currently used surfactants and systematic reviews are needed to establish if it has a role in treatment of RDS.The improvement in outcome for babies <25 weeks has been due to a number of interventions: prenatal steroids, prenatal antibiotics and postnatal surfactant. Clinical trials of surfactant replacement in the neonate continue to be published with remarkable frequency.
Somatic Sensation and the Insular-Opercular Cortex: Relationship to Central Pain
Authors: Bowsher David
Published: May 2006

We report 5 stroke patients with lesions affecting the insula and parietal operculum sparing the postcentral gyrus (somatosensory cortical area SI); 3 had spontaneous central poststroke pain (CPSP) and 2 did not. All were imaged and underwent quantitative sensory threshold tests, though not all modalities were tested in all subjects. Tactile thresholds were unaltered in all. The patients with CPSP exhibited greatly elevated thresholds for mechanical pain (skinfold pinch), sharpness and thermal sensations; the pain-free patients had distinctly lesser elevations of their skinfold pinch and innocuous and noxious thermal thresholds, and no sharpness deficit. It is therefore suggested that, in the case of similar cortical lesions, the presence or absence of spontaneous pain either modifies the thresholds for some innocuous modalities, or that the degree of deficit of some innocuous modalities determines whether or not central pain occurs.
Deletion of the Inducible 70-kDa Heat Shock Protein Genes in Mice Impairs Cardiac Contractile Function and Calcium Handling Associated With Hypertrophy
Authors: Kim Yun-Kyung , Suarez Jorge , Hu Ying , McDonough Patrick M. , Boer Christa , Dix David J. , Dillmann Wolfgang H.
Published: May 2006

Background—

Hspa1a and Hspa1b genes encode stress-inducible 70-kDa heat shock proteins (Hsp70) that protect cells from insults such as ischemia. Mice with null mutations of both genes (KO) were generated, and their cardiac phenotype was explored.

Methods and Results—

Heart rate and blood pressures were normal in the KO mice. Hearts from KO mice were more susceptible to both functional and cellular damage by ischemia/reperfusion. Cardiac hypertrophy developed in Hsp70-KO mice. Ca
2+
transients in cardiomyocytes of KO mice showed a delayed (120%) calcium decline and decreased sarcoplasmic reticulum calcium content. Cell shortening was decreased by 35%, and rates of contraction and relaxation were slower by 40%. These alterations can be attributed to the absence of Hsp70 because viral expression of Hsp70 in KO cultured cardiomyocytes restored these parameters. One mechanism underlying myocyte dysfunction could be decreased SERCA2a expression. This hypothesis was supported by a prolonged calcium decline and decreased SERCA2a protein. Viral SERCA2a expression restored contractility and Ca
2+
transients. We examined the involvement of
Jun
N-terminal kinase (JNK), p38-mitogen–activated protein kinase (p38-MAPK), Raf-1, and extracellular signal–regulated kinase (ERK) in SERCA2a downregulation and the cardiac phenotype of KO mice. Levels of phosphorylated JNK, p38-MAPK, Raf-1, and ERK were elevated in KO hearts. Activation of the Raf-1–ERK pathway in normal cardiomyocytes resulted in decreased SERCA2a.

Conclusions—

Absence of Hsp70 leads to dysfunctional cardiomyocytes and impaired stress response of Hsp70-KO hearts against ischemia/reperfusion. In addition, deletion of Hsp70 genes might induce cardiac dysfunction and development of cardiac hypertrophy through the activation of JNK, p38-MAPK, Raf-1, and ERK.
To What Degree are Environmentally Beneficial Choices Reflective of a General Conservation Stance?
Authors: Thøgersen John , Ölander Folke
Published: May 2006

Whether or not different environmentally beneficial choices have common motivational causes are discussed in the framework of partial correlation analysis with structural equation modeling. Correlations between recycling, buying organic food products, and using public transport or bicycle are analyzed based on telephone interviews with a random sample of about 1,100 Danish residents and two replication samples of about 300 from the same population. The study finds that theoretically meaningful correlations are suppressed by background characteristics. Common motivational causes, that is, environmental values and environmental concern, can account for the significant partial correlations between behaviors after controlling for background characteristics.
For Better or Worse? Self-Esteem and the Contingencies of Acceptance in Marriage
Authors: Murray Sandra L. , Griffin Dale W. , Rose Paul , Bellavia Gina
Published: May 2006

A longitudinal daily diary study examined the origins and consequences of perceiving a partner's acceptance and love as contingent on professional success. Both members of 154 couples completed a diary for 21 days. Multilevel analyses revealed that low self-esteem men and women felt more accepted and loved by their partner on days when their professional lives were marked by success, and low self-esteem women felt less accepted and loved on days when their professional lives were marked by failure. No such spillover effects between people's professional and relationship lives emerged for people high in chronic selfesteem. A 1-year longitudinal follow-up revealed that people who initially felt less accepted across days reported decreased satisfaction. Men also became especially distressed when their wives felt less accepted initially and (incorrectly) perceived their husbands' regard as contingent.
Self-Verification and Contextualized Self-Views
Authors: Chen Serena , English Tammy , Peng Kaiping
Published: May 2006

Whereas most self-verification research has focused on people's desire to verify their global self-conceptions, the present studies examined self-verification with regard to contextualized selfviews—views of the self in particular situations and relationships. It was hypothesized that individuals whose core self-conceptions include contextualized self-views should seek to verify these self-views. In Study 1, the more individuals defined the self in dialectical terms, the more their judgments were biased in favor of verifying over nonverifying feedback about a negative, situation-specific self-view. In Study 2, consistent with research on gender differences in the importance of relationships to the self-concept, women but not men showed a similar bias toward feedback about a negative, relationship-specific self-view, a pattern not seen for global self-views. Together, the results support the notion that self-verification occurs for core self-conceptions, whatever form(s) they may take. Individual differences in self-verification and the nature of selfhood and authenticity are discussed.
A Procedure for Evaluating Sensitivity to Within-Person Change: Can Mood Measures in Diary Studies Detect Change Reliably?
Authors: Cranford James A. , Shrout Patrick E. , Iida Masumi , Rafaeli Eshkol , Yip Tiffany , Bolger Niall
Published: May 2006

The recent growth in diary and experience sampling research has increased research attention on how people change over time in natural settings. Often however, the measures in these studies were originally developed for studying between-person differences, and their sensitivity to within-person changes is usually unknown. Using a Generalizability Theory framework, the authors illustrate a procedure for developing reliable measures of change using a version of the Profile of Mood States (POMS; McNair, Lorr, & Droppleman, 1992) shortened for diary studies. Analyzing two data sets, one composed of 35 daily reports from 68 persons experiencing a stressful examination and another composed of daily reports from 164 persons over a typical 28-day period, we demonstrate that three-item measures of anxious mood, depressed mood, anger, fatigue, and vigor have appropriate reliability to detect within-person change processes.
A New Clinical Collective for French Cancer Genetics
Authors: Bourret Pascale , Mogoutov Andrei , Julian-Reynier Claire , Cambrosio Alberto
Published: May 2006

Collaborative forms of work such as extended networks, expert groups, and consortia increasingly structure biomedical activities. They are particularly prominent in the cancer field, where procedures such as multicenter clinical trials have been instrumental in establishing the specialty of oncology, and subfields such as cancer genetics, where bioclinical activities—for example, testing for breast and ovarian cancer (BRCA) genes and follow-up interventions—are predicated on the articulation of a number of tasks performed by new clinical collectives. In this article, we examine the founding and development of a French bioclinical collective—the Groupe Génétique et Cancer (GGC)—that coordinates and structures the activities of most French actors in cancer genetics and operates simultaneously in the clinical, research, and regulatory domains. To examine the group’s structure and dynamics, the article combines information gathered through traditional fieldwork methods with information elicited from a coauthorship and semantic-network analysis of the publications of GGC members from 1969 to 2001.
Arthroscopic versus Open Shoulder Stabilization for Recurrent Anterior Instability
Authors: Bottoni Craig R. , Smith Eric L. , Berkowitz Mark J. , Towle Robert B. , Moore Josef H.
Published: May 2006

Background

Arthroscopic stabilization for anterior shoulder instability has been reported to result in a higher rate of recurrent instability compared to traditional open techniques.

Purpose

To test the null hypothesis that there is no difference in the clinical outcomes in patients with recurrent anterior shoulder instability treated with open or arthroscopic stabilization.

Study Design

Randomized controlled trial; Level of evidence, 1.

Methods

A consecutive series of 64 patients with recurrent anterior shoulder instability were randomized to receive either arthroscopic or open stabilization by a single surgeon. Magnetic resonance arthrogram studies were obtained preoperatively. These findings were compared to arthroscopic findings. Postoperative evaluations included range of motion, stability, and subjective assessments including Single Assessment Numeric Evaluation, Simple Shoulder Test, Western Ontario Instability Index, and University of California, Los Angeles evaluation. Failure was defined as a second dislocation, recurrent subluxation, or symptoms precluding return to previous work or unrestricted active military duty.

Results

Sixty-one patients, 29 who received open stabilization and 32 who received arthroscopic stabilization, were evaluated at a mean of 32 months postoperatively (range, 24-48 months). Patient demographics were equivalent. Preoperative magnetic resonance arthrogram findings were confirmed at arthroscopic examination. The mean operative time was significantly shorter for the arthroscopic repairs (59 vs 149 minutes; P <. 001). There were 3 clinical failures (2 open stabilizations, 1 arthroscopic stabilization) by the established criteria. There was a statistically significant improvement from preoperative to postoperative Single Assessment Numeric Evaluation scores in both groups (P <. 001). The mean loss of motion (compared to the contralateral shoulder) was greater in the open shoulders. Subjective evaluations were equal in both groups.

Conclusion

Clinical outcomes after arthroscopic and open stabilization were comparable. Preoperative magnetic resonance arthrograms in shoulders with anterior instability allow an accurate diagnosis of intra-articular abnormality that correlates well with operative findings. Arthroscopic stabilization for recurrent anterior shoulder instability can be performed safely; the clinical outcomes are comparable to those after traditional open stabilization.
Adult murine hematopoiesis can proceed without β1 and β7 integrins
Authors: Bungartz Gerd , Stiller Sebastian , Bauer Martina , Müller Werner , Schippers Angela , Wagner Norbert , Fässler Reinhard , Brakebusch Cord
Published: May 2006

The function of α4β1 and α4β7 integrins in hematopoiesis is controversial. While some experimental evidence suggests a crucial role for these integrins in retention and expansion of progenitor cells and lymphopoiesis, others report a less important role in hematopoiesis. Using mice with a deletion of the β1 and the β7 integrin genes restricted to the hematopoietic system we show here that α4β1 and α4β7 integrins are not essential for differentiation of lymphocytes or myelocytes. However, β1β7 mutant mice displayed a transient increase of colony-forming unit (CFU-C) progenitors in the bone marrow and, after phenylhydrazine-induced anemia, a decreased number of splenic erythroid colony-forming units in culture (CFUe's). Array gene expression analysis of CD4+CD8+ double-positive (DP) and CD4–CD8– double-negative (DN) thymocytes and CD19+ and CD4+ splenocytes did not provide any evidence for a compensatory mechanism explaining the mild phenotype. These data show that α4β1 and α4β7 are not required for blood cell differentiation, although in their absence alterations in numbers and distribution of progenitor cells were observed.
Early prediction of therapy response in patients with acute myeloid leukemia by nucleosomal DNA fragments
Authors: Mueller Susanne , Holdenrieder Stefan , Stieber Petra , Haferlach Torsten , Schalhorn Andreas , Braess Jan , Nagel Dorothea , Seidel Dietrich
Published: May 2006

Background

Elevated levels of nucleosomal DNA fragments can be detected in plasma and sera of patients with malignant diseases.

Methods

We investigated the course of nucleosomal DNA, thymidine kinase, lactate dehydrogenase and leukocytes in sera of 25 patients with acute myeloid leukemia during the first cycle of induction chemotherapy and tested their power to distinguish between patients with complete remission and those with no remission.

Results

Almost all patients showed strongly decreasing levels of nucleosomal DNA during the first week, in some cases after initial peaks. In overall analysis of variance, DNA levels could clearly distinguish between patients with complete remission, who had higher DNA values, and those with insufficient response (p = 0.017). The area under the curve of DNA values of days 2–4 after start of therapy (AUC 2–4) discriminated between both groups with a sensitivity of 56% at a specificity of 100%. Further, pretherapeutic levels and AUC 2–4 of nucleosomal DNA correlated significantly with blast reduction after 16 days. A tendency to higher levels in patients with complete response was also found for thymidine kinase, lactate dehydrogenase and leukocytes, however the difference did not reach the level of significance (p = 0.542, p = 0.260, and p = 0.144, respectively).

Conclusion

Our results indicate that nucleosomal DNA fragments are valuable markers for the early prediction of therapeutic efficacy in patients with acute myeloid leukemia.
The Canadian Natural Health Products (NHP) regulations: industry perceptions and compliance factors
Authors: Laeeque Hina , Boon Heather , Kachan Natasha , Cohen Jillian Clare , D'Cruz Joseph
Published: May 2006

Background

The use of natural health products, such as vitamins, minerals, and herbs, by Canadians has been increasing with time. As a result of consumer concern about the quality of these products, the Canadian Department of Health created the Natural Health Products (NHP) Regulations. The new Canadian regulations raise questions about whether and how the NHP industry will be able to comply and what impact they will have on market structure. The objectives of this study were to explore who in the interview sample is complying with Canada's new NHP Regulations (i.e., submitted product licensing applications on time); and explore the factors that affect regulatory compliance.

Methods

Twenty key informant interviews were conducted with employees of the NHP industry. The structured interviews focused on the level of satisfaction with the Regulations and perceptions of compliance and non-compliance. Interviews were tape recorded and then transcribed verbatim. Data were independently coded, using qualitative content analysis. Team meetings were held after every three to four interviews to discuss emerging themes.

Results

The major finding of this study is that most (17 out of 20) companies interviewed were beginning to comply with the new regulatory regime. The factors that contribute to likelihood of regulatory compliance were: perceptions and knowledge of the regulations and business size.

Conclusion

The Canadian case can be instructive for other countries seeking to implement regulatory standards for natural health products. An unintended consequence of the Canadian NHP regulations may be the exit of smaller firms, leading to industry consolidation.
Behavior change following a self-management intervention for housebound older adults with arthritis: an experimental study
Authors: Nour Kareen , Laforest Sophie , Gauvin Lise , Gignac Monique
Published: May 2006

Background

This study examined the impact of a home-based self-management intervention for housebound older adults with arthritis on the adoption of health behaviors. The moderating role of socio-demographic, psychological, and physical characteristics in the process of behavior change was also investigated.

Methods

Participants were 113 older adult women (n = 102) and men (n = 11) with osteoarthritis (OA) or rheumatoid arthritis (RA) who were randomly assigned to experimental (n = 68) or wait list control (n = 45) groups. Participants were interviewed using standardized questionnaires at baseline, pre-intervention, and post-intervention.

Results

Adjusted multilevel modeling analyses indicated that from pre to post intervention, experimental participants significantly increased their weekly frequency of exercise and relaxation activities. Socioeconomic status and depression played a moderating role in this change for exercise with larger effects occurring among more privileged, non-depressed participants.

Conclusion

We conclude that a self-management intervention can successfully improve involvement in exercise and relaxation among housebound older adults with arthritis.
Seasonal variation in concentration and metallic constituents of atmospheric particulates near the western coast of central Taiwan
Authors: Fang Guor-Cheng , Wu Yuh-Shen , Lee Wen-Jhy , Chou Te-Yen , Lin I-Chen
Published: May 2006

In addition to determining the concentration and metallic constituents of particulate matter at Taichung Harbor in central Taiwan, this study attempts to characterize the mass, metallic elements, composition and concentrations of total suspended particulates (TSP), fine particles and coarse particles. Statistical approaches, such as the Spearman tests, were also adopted to determine the seasonal variations of concentrations of these pollutants. Experimental results indicate that the mean TSP, fine particulate and coarse particulate concentrations in spring and winter are higher than in summer and autumn on the western coast of central Taiwan. Spearman statistical analysis of metallic elements Mn and Pb showed high concentration coefficients for fine and coarse particulates on the western coast of central Taiwan. The order of mean metallic concentrations in TSP, coarse particulates and fine particles was Fe-Zn-Mg-Cu-Cr-Mn-Pb in TSP, Fe-Cu-Zn-Mg-Mn-Pb-Cr in coarse particulates and Fe-Cu-Mg-Pb-Zn-Mn-Cr in fine particulates.
Hodgkin's Lymphoma in Adolescents
Authors: Foltz Lynda M. , Song Kevin W. , Connors Joseph M.
Published: May 2006

Purpose

To compare the clinical presentation, response to treatment, and long-term outcome of Hodgkin's lymphoma (HL) presenting in adolescents and young adults.

Patients and Methods

The British Columbia Cancer Agency Lymphoid Cancer database was used to identify adolescents (16 years to 21 years) and young adults (22 years to 45 years) receiving primary treatment for HL between 1981 and 2004. All patients were treated using adult protocols.

Results

The study population included 259 adolescents and 890 young adults. There were no significant differences in histologic subtypes, sex, stages, or presence of B symptoms or bulky disease between adolescents and adults. Equal proportions of adolescents and adults were treated with radiation alone (38% v 35%), chemotherapy alone (13% v 15%), or combined-modality programs (49% v 50%). There was no difference in progression-free survival (PFS) or overall survival (OS) between adolescents and adults, with 10-year PFS rates of 77% versus 80% (P = .67) and 10-year OS rates of 91% versus 89% (P = .42). In limited stage disease, 10-year PFS was 89% for adolescents and 89% for adults and OS 96% and 96%, respectively. In advanced stage disease, 10-year PFS was 71% for adolescents and 75% for adults and OS 88% and 86%, respectively. Actuarial risk of second malignancy for adolescents and adults was not different (P = .68).

Conclusion

Adolescents and young adults with HL have similar baseline characteristics and achieve similar outcomes when treated with the same protocols. The use of adult treatment protocols is a safe and effective strategy for treating adolescents with HL.
FER-1 regulates Ca2+-mediated membrane fusion during C. elegans spermatogenesis
Authors: Washington N. L. , Ward S.
Published: May 2006

FER-1 is required for fusion of specialized vesicles, called membranous organelles, with the sperm plasma membrane during Caenorhabditis elegans spermiogenesis. To investigate its role in membranous organelle fusion, we examined ten fer-1 mutations and found that they all cause the same defect in membrane fusion. FER-1 and the ferlin protein family are membrane proteins with four to seven C2 domains. These domains commonly mediate Ca2+-dependent lipid-processing events. Most of the fer-1 mutations fall within these C2 domains, showing that they have distinct, non-redundant functions. We found that membranous organelle fusion requires intracellular Ca2+ and that C2 domain mutations alter Ca2+ sensitivity. This suggests that the C2 domains are involved in Ca2+ sensing and further supports their independent function. Using two immunological approaches we found three FER-1 isoforms, two of which might arise from FER-1 by proteolysis. By both light and electron microscopy, these FER-1 proteins were found to be localized to membranous organelle membranes. Dysferlin, a human homologue of FER-1 involved in muscular dystrophy, is required for vesicle fusion during Ca2+-induced muscle membrane repair. Our results suggest that the ferlin family members share a conserved mechanism to regulate cell-type-specific membrane fusion.
Human Bcl-2 cannot directly inhibit the Caenorhabditis elegans Apaf-1 homologue CED-4, but can interact with EGL-1
Authors: Jabbour A. M. , Puryer M. A. , Yu J. Y. , Lithgow T. , Riffkin C. D. , Ashley D. M. , Vaux D. L. , Ekert P. G. , Hawkins C. J.
Published: May 2006

Although the anti-apoptotic activity of Bcl-2 has been extensively studied, its mode of action is still incompletely understood. In the nematode Caenorhabditis elegans, 131 of 1090 somatic cells undergo programmed cell death during development. Transgenic expression of human Bcl-2 reduced cell death during nematode development, and partially complemented mutation of ced-9, indicating that Bcl-2 can functionally interact with the nematode cell death machinery. Identification of the nematode target(s) of Bcl-2 inhibition would help clarify the mechanism by which Bcl-2 suppresses apoptosis in mammalian cells. Exploiting yeast-based systems and biochemical assays, we analysed the ability of Bcl-2 to interact with and regulate the activity of nematode apoptosis proteins. Unlike CED-9, Bcl-2 could not directly associate with the caspase-activating adaptor protein CED-4, nor could it inhibit CED-4-dependent yeast death. By contrast, Bcl-2 could bind the C. elegans pro-apoptotic BH3-only Bcl-2 family member EGL-1. These data prompt us to hypothesise that Bcl-2 might suppress nematode cell death by preventing EGL-1 from antagonising CED-9, rather than by inhibiting CED-4.
Adaptive Importance Sampling Technique for Markov Chains Using Stochastic Approximation
Authors: Ahamed T. P. I. , Borkar V. S. , Juneja S.
Published: May 2006

For a discrete-time finite-state Markov chain, we develop an adaptive importance sampling scheme to estimate the expected total cost before hitting a set of terminal states. This scheme updates the change of measure at every transition using constant or decreasing step-size stochastic approximation. The updates are shown to concentrate asymptotically in a neighborhood of the desired zero-variance estimator. Through simulation experiments on simple Markovian queues, we observe that the proposed technique performs very well in estimating performance measures related to rare events associated with queue lengths exceeding prescribed thresholds. We include performance comparisons of the proposed algorithm with existing adaptive importance sampling algorithms on some examples. We also discuss the extension of the technique to estimate the infinite horizon expected discounted cost and the expected average cost.
Community-Associated Methicillin-Resistant Staphylococcus aureus: New Bug, Old Drugs
Authors: Sabol Kathryn E , Echevarria Kelly L , Lewis James S
Published: May 2006

Objective:

To discuss community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections and evaluate older antibiotics as suitable therapeutic treatment options.

Data Sources:

Searches of MEDLINE, EMBASE, and the Cochrane Library (1966–May 2006) were performed using the key terms methicillin resistance, community-acquired, community associated, treatment, Staphylococcus aureus, mec, and Panton-Valentine leukocidin.

Study Selection and Data Extraction:

All articles were critically evaluated and all relevant information was included in this review.

Data Synthesis:

There has been a documented shift of methicillin resistance occurring in staphylococcal infections manifested within the community. Infections caused by CA-MRSA possess unique characteristics including lack of hospital-associated risk factors, improved susceptibility patterns, distinct genotypes, faster doubling times, and additional toxins. Potential therapeutic options to treat these infections include trimethoprim/sulfamethoxazole (TMP/SMX), clindamycin, tetracyclines, fluoroquinolones, and new antimicrobials.

Conclusions:

CA-MRSA infections can be successfully treated with older, oral antibiotic agents including TMP/SMX, clindamycin, and tetracyclines. Fluoroquinolones and linezolid should be avoided as first-line agents.
PET-blot Analysis Contributes to BSE Strain Recognition in C57Bl/6 Mice
Authors: Lezmi Stéphane , Bencsik Anna , Baron Thierry
Published: May 2006

Identification of the strain of agent responsible for bovine spongiform encephalopathy (BSE) can be made histologically through the analysis of both distribution and intensity of brain vacuolar lesions after BSE transmission to mouse. Another useful way to distinguish the BSE agent from other prion strains is the study of the distribution of the abnormal prion protein (PrPres). For that purpose, paraffin-embedded tissue blot (PET-blot) method was applied on brains from C57Bl/6 mice infected with cattle BSE, experimental sheep BSE, or feline spongiform encephalopathy (FSE) from a cheetah. PrPres distribution was comparable, whichever of the three BSE agent sources was considered and was distinct from the PrPres distribution in C57Bl/6 mice inoculated with a French scrapie isolate or with a mouse-adapted scrapie strain (C506M3). These data confirm a common origin of infectious agent responsible for the British and French cattle BSE. They also indicate that PET-blot method appears as a precise complementary tool in prion strain studies because it offers easy and quick assessment of the PrPres mapping. Advantages and limits of the PET-blot method are discussed and compared with other established and validated methods of strain typing.
Injectable Calcium Phosphate Bone Cement Provides Favorable Space and a Scaffold for Periodontal Regeneration in Dogs
Authors: Hayashi Chie , Kinoshita Atsuhiro , Oda Shigeru , Mizutani Koji , Shirakata Yoshinori , Ishikawa Isao
Published: May 2006

Background: An earlier study showed that an injectable calcium phosphate cement (CPC) served as a stable scaffold for bone formation and promoted histocompatible healing of periodontal tissue in dogs. In this study, we evaluated the influence of CPC on regeneration of periodontal defects with experimental periodontitis in dogs.

Methods: Experimental periodontitis was induced by placing stainless‐steel mesh on the mesial side of maxillary canines in six adult, healthy beagle dogs. Subsequently, intrabony defects were resized so as to be standard, and CPC was injected in the experimental bone defects. Non‐grafted defects on the contralateral side served as controls. Twelve weeks after surgery, the animals were sacrificed and histologic specimens were prepared. Periodontal tissue healing was evaluated histologically and histometrically.

Results: Healing of periodontal tissues, in terms of bone and cementum formation, was consistently observed in the CPC‐applied sites. CPC was partly replaced by new bone. New cementum and periodontal ligament‐like tissue were observed between CPC and the root surface. New bone (P <0.05), new cementum (P <0.01), and new connective tissue attachment and adhesion (P <0.05) were significantly enhanced in the experimental sites.

Conclusion: Calcium phosphate cement provides stable wound healing and enhanced periodontal regeneration in periodontal defects in dogs with experimental periodontitis.
Effect of Enamel Matrix Protein Derivative on Healing of Surgical Supra‐Infrabony Periodontal Defects in the Rat Molar: A Histomorphometric Study
Authors: Nemcovsky Carlos E. , Zahavi Shira , Moses Ofer , Kebudi Edmon , Artzi Zvi , Beny Leah , Weinreb Miron
Published: May 2006

Background: Enamel matrix protein derivative (EMD) has proven to enhance periodontal regeneration in human and animal studies. The present histomorphometric study evaluated healing of combined supra‐infrabony periodontal defects with EMD.

Methods: The study comprised two groups of 10 Wistar rats each, 7 to 8 months old. Bony defects were created on the mesial aspect of the mesial root of the first maxillary molar. The root surface was planed and 24% EDTA gel applied for 2 minutes and then rinsed with water. In the study group, EMD was applied, and in the control group, only propylene glycol alginate was applied. Animals were sacrificed 12 weeks after surgery, and block sections were removed, demineralized, and embedded in paraffin. For histomorphometric analysis, three sections from the central area of the defect were selected. Root, surgical defect, epithelial attachment, sulcus, supracrestal connective tissue, ankylosis, and the length and area of new cementum and new bone were measured.

Results: No statistically significant differences between the two groups were found for root and defect measures. The remaining parameters were calculated as a percentage of the defect. In the study group, smaller gingival recession (P = 0.05), deeper gingival sulcus (P = 0.05), and shorter junctional epithelium (P = 0.01) were found. New cementum was observed in the study group only (P = 0.02). Ankylosis was six times larger in the control group but not statistically significant. New bone formation was similar in both groups.

Conclusion: Enamel matrix protein derivative enhanced periodontal healing in this model by reducing gingival recession and junctional epithelium along the root surface and enhancing the formation of new cementum.
Feasibility and Influence of the Microgap of Two Implants Placed in a Non‐Submerged Procedure: A Five‐Year Follow‐Up Clinical Trial
Authors: Heijdenrijk Kees , Raghoebar Gerry M. , Meijer Henny J.A. , Stegenga Boudewijn , van der Reijden Wil A.
Published: May 2006

Background: The aim of this study was to evaluate the feasibility of using a two‐piece implant system in a non‐submerged procedure and to study the impact of the microgap between the implant and abutment.

Methods: Sixty edentulous patients (Cawood Class V‐VI) participated in this study. After randomization, 20 patients received two two‐piece implants placed in a non‐submerged procedure, 20 patients received two two‐piece implants placed in the traditional submerged procedure, and 20 patients were treated with two one‐piece dental implants placed in the traditional non‐submerged procedure. The implants were placed in the mandible for overdenture treatment. A standardized clinical evaluation was performed and radiographs were taken immediately after denture insertion and yearly up to 5 years. Peri‐implant samples were collected 12, 36, and 60 months after loading with sterile paper points and analyzed for the presence of putative periodontal pathogens using culture techniques.

Results: One two‐piece implant of the non‐submerged group and one two‐piece implant of the submerged group were lost after 6 and 12 months, respectively. After 5 years of functioning, no significant clinical, radiological, or microbiological differences were found between the three groups. No association was found between the level of the microgap and the amount of bone loss.

Conclusions: The results of this study indicate that dental implants designed for a submerged implantation procedure can also be used in a non‐submerged procedure and may be as predictable as when used in a submerged procedure or as one‐piece implants. The microgap at the crestal level in two‐piece implants does not appear to have an adverse effect on the amount of peri‐implant bone loss.
The Effects of Respite Care for Homeless Patients: A Cohort Study
Authors: Buchanan David , Doblin Bruce , Sai Theophilus , Garcia Pablo
Published: May 2006

Objectives. Homeless individuals experience high rates of physical and mental illness, increased mortality, and frequent hospitalizations. Respite care provides homeless individuals with housing and services allowing more complete recovery from illnesses and stabilization of chronic conditions.

Methods. We investigated respite care’s impact on 225 hospitalized homeless adults consecutively referred from an urban public hospital during a 26-month period. The cohort was separated into 2 groups: (1) patients referred and accepted into the respite center and (2) patients referred but denied admission because beds were unavailable. All patients met the center’s predefined eligibility criteria. Main outcome measures were inpatient days, emergency department visits, and outpatient clinic visits.

Results. The 2 groups had similar demographic characteristics, admitting diagnoses, and patterns of medical care use at baseline. During 12 months of follow-up, the respite care group required fewer hospital days than the usual care group (3.7 vs 8.3 days; P=.002), with no differences in emergency department or outpatient clinic visits. Individuals with HIV/AIDS experienced the greatest reduction in hospital days.

Conclusions. Respite care after hospital discharge reduces homeless patients’ future hospitalizations.
Healthy Naturally Occurring Retirement Communities: A Low-Cost Approach to Facilitating Healthy Aging
Authors: Masotti Paul J. , Fick Robert , Johnson-Masotti Ana , MacLeod Stuart
Published: May 2006

Naturally occurring retirement communities (NORCs) are broadly defined as communities where individuals either remain or move when they retire. Using the determinants of health model as a base, we hypothesize that some environmental determinants have a different impact on people at different ages.

Health benefits to living within NORCs have been observed and likely vary depending upon where the specific NORC exists on the NORC to healthy-NORC spectrum. Some NORC environments are healthier than others for seniors, because the NORC environment has characteristics associated with better health for seniors. Health benefits within healthy NORCs are higher where physical and social environments facilitate greater activity and promote feelings of well-being.

Compared to the provision of additional medical or social services, healthy NORCs are a low-cost community-level approach to facilitating healthy aging. Municipal governments should pursue policies that stimulate and support the development of healthy NORCs.
The Alabama Embryo Decision—The Politics and Reality of Recognizing “Extrauterine Children”
Authors: Feinberg Rebecca S. , Sinha Michael S. , Cohen I. Glenn
Published: March 2024

This Viewpoint discusses the Alabama Supreme Court’s opinion on in vitro fertilization and how it plays into a larger push for fetal and embryonic personhood.
Catholic Hospital Affiliation and Postpartum Contraceptive Care and Subsequent Deliveries
Authors: Meille Giacomo , Monnet Jessica N.
Published: March 2024

Importance

In recent years, the number of Catholic hospitals has grown, raising concerns about access to contraception. The association between living in an area in which the closest hospital is Catholic and the probability of postpartum contraception and subsequent deliveries is unknown.

Objective

To assess whether living in an area in which the closest hospital was Catholic was associated with the probability of postpartum contraception and subsequent deliveries.

Design, Setting, and Participants

This cohort study used data from the Healthcare Cost and Utilization Project’s State Inpatient Databases, State Emergency Department Databases, and State Ambulatory Surgery and Services Databases for 11 states (California, Florida, Georgia, Missouri, Nebraska, Nevada, New York, South Carolina, Tennessee, Vermont, and Wisconsin). Female patients with a delivery from 2016 to 2019 who lived within 20 miles of a nonfederal acute care hospital were included, with patients followed up for 1 to 3 years. Coarsened exact matching was used to match patients based on the county-level percentage of the population affiliated with Catholic churches and urbanicity, and the zip code–level number of hospitals within 5 and 20 miles, median household income, and percentage of the population by race and ethnicity. Data were analyzed from April 2022 to November 2023.

Exposures

Residence in a zip code in which the closest hospital was Catholic.

Main Outcomes and Measures

Probabilities of delivery at a Catholic hospital, surgical sterilization within 1 year of delivery, receipt of long-acting reversible contraception at delivery, and subsequent delivery within 3 years.

Results

The sample consisted of 4 101 443 deliveries (1 301 792 after matching), with 14.5% of patients living in exposed zip codes (ie, where the closest hospital was Catholic). Living in exposed zip codes was associated with a 21.26–percentage point (pp) increase in the probability of delivery at a Catholic hospital (95% CI, 19.50 to 23.02 pp; 237.3% relative to the mean in unexposed zip codes; P < .001). Additionally, comparing exposed vs unexposed zip codes, the probability of surgical sterilization at delivery decreased by 0.95 pp (95% CI, −1.14 to −0.76 pp; P < .001) and the probability of sterilization in the year after discharge further decreased by 0.21 pp (95% CI, −0.29 to −0.13; P < .001). Subsequent deliveries within 3 years increased 0.47 pp (95% CI, −0.03 to 0.97 pp; 2.3% relative to the mean in unexposed zip codes; P = .07).

Conclusions and Relevance

This cohort study finds that living in a zip code in which the closest hospital was Catholic was associated with a modest decrease in the probability of postpartum surgical sterilizations and a modest increase in the probability of subsequent deliveries.
Coma Prognostication After Acute Brain Injury
Authors: Fischer David , Edlow Brian L.
Published: March 2024

Importance

Among the most impactful neurologic assessments is that of neuroprognostication, defined here as the prediction of neurologic recovery from disorders of consciousness caused by severe, acute brain injury. Across a range of brain injury etiologies, these determinations often dictate whether life-sustaining treatment is continued or withdrawn; thus, they have major implications for morbidity, mortality, and health care costs. Neuroprognostication relies on a diverse array of tests, including behavioral, radiologic, physiological, and serologic markers, that evaluate the brain’s functional and structural integrity.

Observations

Prognostic markers, such as the neurologic examination, electroencephalography, and conventional computed tomography and magnetic resonance imaging (MRI), have been foundational in assessing a patient’s current level of consciousness and capacity for recovery. Emerging techniques, such as functional MRI, diffusion MRI, and advanced forms of electroencephalography, provide new ways of evaluating the brain, leading to evolving schemes for characterizing neurologic function and novel methods for predicting recovery.

Conclusions and Relevance

Neuroprognostic markers are rapidly evolving as new ways of assessing the brain’s structural and functional integrity after brain injury are discovered. Many of these techniques remain in development, and further research is needed to optimize their prognostic utility. However, even as such efforts are underway, a series of promising findings coupled with the imperfect predictive value of conventional prognostic markers and the high stakes of these assessments have prompted clinical guidelines to endorse emerging techniques for neuroprognostication. Thus, clinicians have been thrust into an uncertain predicament in which emerging techniques are not yet perfected but too promising to ignore. This review illustrates the current, and likely future, landscapes of prognostic markers. No matter how much prognostic markers evolve and improve, these assessments must be approached with humility and individualized to reflect each patient’s values.
Changes to Sexual Identity Response Options in the Youth Risk Behavior Survey
Authors: Phillips Gregory L. , Curtis Michael G. , Kelsey Scar Winter , Floresca Ysabel Beatrice , Davoudpour Shahin , Quiballo Kagen , Beach Lauren B.
Published: March 2024

This survey study discusses changes in the proportion of youths who selected “not sure” among other response options to questions about their sexual identity in the National Youth Risk Behavior Survey between 2019 and 2021 and recommends measures to inclusively reflect sexual identities.