bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Public Health Nursing Competencies: An Oral History
Authors: King Marilyn Givens , Erickson Grace P.
Published: May 2006

ABSTRACT
This paper identifies the external and internal forces that led to the initiation and completion of a set of Public Health Nursing (PHN) competencies by nursing representatives from the Quad Council (QC) organizations: the Association of Community Health Nursing Educators, the American Public Health Association/Public Health Nursing Section, the Association of State and Territorial Directors of Nursing, and the American Nurses Association Congress on Nursing Practice and Economics. Discussion on the need for competencies began in 1988 with the Institute of Medicine report, The Future of Public Health, which cited a widening gap between the education and practice of public health (PH). PH leaders promptly responded by initiating many interactions to improve academic programs and enhance workforce development, including the development of competencies for PH professionals. PHN responded through the Quad Council of Public Health Nursing Organizations, which completed development of a set of national PHN competencies in 2003. The unfolding of that process is reported from the content‐specific oral histories of five PHN leaders who served on the QC and participated in developing the PHN competencies.
Guiding Mothers' Management of Health Problems of Very Low Birth‐Weight Infants
Authors: Pridham Karen A. , Krolikowski Mary M. , Limbo Rana K. , Paradowski Jill , Rudd Nancy , Meurer John R. , Uttech Ann , Henriques Jeffrey B.
Published: May 2006

ABSTRACT Objective:Explore the feasibility, usefulness, and outcomes of a pilot program to support mothers in developing competencies for managing health problems of their very low birth‐weight (VLBW) infants in partnership with the primary care clinician (PCC).

Design:In a randomized study, mothers who received guided participation (GP) and printed guidelines for managing VLBW infant health problems were compared with mothers who received only the guidelines and standard care (GL group).

Sample:All mothers (GP=20; GL=11) were at least 18 years old and English speaking. Infants were all VLBW (≤1,500 g).

Intervention:GP began during the infant's neonatal intensive care unit stay and continued with public health nurses (PHNs) and a family service clinician through the infant's first 4 postterm months.

Measurements:Intervention feasibility and usefulness were assessed with maternal and clinician feedback. Outcomes included maternal and clinician appraisal of mothers' use of clinical resources and mothers' perceptions of primary‐care quality and the family‐PCC relationship.

Results:Intervention feasibility and usefulness were supported. GP and GL groups did not differ significantly on outcomes.

Conclusions:Findings indicate a longer intervention period, GP organized by infant problem episodes, and enhancement of the PHN role in the context of interdisciplinary and interagency collaboration.
Perceptions of Effectiveness of Nurse‐Managed Clinics: A Cross‐Cultural Study
Authors: Krothe Joyce Splann , Clendon Jill M.
Published: May 2006

ABSTRACT
Objective: To study perceptions of the effectiveness of two nurse‐managed clinics (NMCs), one in the United States and the other in New Zealand.

Design: Cross‐cultural evaluation study utilizing qualitative methodology; two rounds of in‐depth interviews were tape recorded, transcribed verbatim, and analyzed for themes.

Sample: Data were initially collected from 21 participants. Sixteen of the original participants participated in a second interview.

Intervention: The first round of interviews and provisional data analysis were conducted in the respective NMCs; joint data analysis to identify themes and develop a preliminary joint report of findings followed. Sixteen participants responded to the provisional report; additional data analysis resulted in the final report of findings.

Results: Analysis of the data yielded three categories: the NMC milieu affects perceived effectiveness; perceptions are shaped by contrasting with past experiences; and the level of care affects personal health care decisions.

Conclusions: The milieu created in the NMC enhances perceptions of effectiveness and responsibility for personal health care. Further research related to effectiveness of NMC models of care and client outcomes is needed. Qualitative methodology is recommended for cross‐cultural research.
Education, Cognitive Test Scores, and Black‐White Differences in Dementia Risk
Authors: Shadlen Marie‐Florence , Siscovick David , Fitzpatrick Annette L. , Dulberg Corinne , Kuller Lewis H. , Jackson Sharon
Published: May 2006

OBJECTIVES: To compare dementia risks of elderly black and white subjects and to determine whether differences in education and cognitive test scores contribute to the inconsistency in reported differences between these groups.

DESIGN: Longitudinal, 6‐year follow‐up.

PARTICIPANTS: Two thousand seven hundred eighty‐six older black and white subjects in the Cardiovascular Health Study.

MEASUREMENTS: Age, education (>10 years vs ≤10 years), Modified Mini‐Mental State Examination score (3MS, ≤85 vs >85). Potential confounders were sex, depression, apolipoprotein E4 genotype, vascular disease, and baseline magnetic resonance imaging changes.

RESULTS: White subjects with low education and black subjects with high education had twice the risk of dementia of white subjects with high education (95% confidence interval (CI)=1.5–2.4 and 95% CI=1.4–2.7); black subjects with low education had five times the risk of dementia (95% CI=3.4–7.7). Likewise, for subjects with low 3MSE scores, black subjects had 6.7 times the risk of dementia (95% CI=4.7–9.7) and white subjects had 2.7 times the risk of dementia (95% CI=2.2–3.5) as white subjects with high 3MSE scores. Finally, in Cox models, there was no significant black‐white difference in dementia risk after adjustment for all confounders and baseline 3MSE.

CONCLUSION: Black race was associated with greater dementia risk even after adjustment for education and other potential confounders. This black‐white difference in dementia risk was markedly attenuated after adjustment for baseline cognitive screening scores. The apparent race effect may reflect gaps in the quality of education or differences in the trajectory of impaired cognitive function experienced by the two groups. Future investigations might take these findings into consideration for the design of studies evaluating black‐white differences in dementia risk.
Hyperventilation, More than Just Hot Air
Authors: Blume Warren T.
Published: May 2006

Hyperventilation Revisited: Physiological Effects and Efficacy on Focal Seizure Activation in the Era of Video-EEG Monitoring

Guaranha MS, Garzon E, Buchpiguel CA, Tazima S, Yacubian EM, Sakamoto AC

Epilepsia 2005;46(1):69–75

Purpose

Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies. In this study, we assessed its effectiveness in inducing focal seizures during video-EEG monitoring.

Methods

We analyzed the effects of hyperventilation (HV) during video-EEG monitoring of patients with medically intractable focal epilepsies. We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures.

Results

We analyzed 97 patients; 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT).

Conclusions

HV is a safe and effective method of seizure activation during monitoring. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery.
H-Channel Dysfunction in Generalized Epilepsy: It Takes Two
Authors: Poolos Nicholas P.
Published: May 2006

Impaired Regulation of Thalamic Pacemaker Channels Through an Imbalance of Subunit Expression in Absence Epilepsy

Budde T, Caputi L, Kanyshkova T, Staak R, Abrahamczik C, Munsch T, Pape HC

J Neurosci 2005;25(43):9871–9882

The role of hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channel isoforms and hyperpolarization-activated cation current ( Ih) for seizure-related burst firing in thalamocortical (TC) neurons was investigated in a rat genetic model of absence epilepsy [Wistar Albino Glaxo rats, bred in Rijswijk (WAG/Rij)]. Burst discharges in TC neurons locked to seizure activity in vivo were prolonged during blockade of Ih by Cs+ and ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidinium chloride). In vitro analyses revealed a hyperpolarizing shift of half-maximal Ih activation ( Vh) in WAG/Rij ( Vh = −93.2 mV) compared with nonepileptic controls [August × Copenhagen-Irish (ACI) ( Vh = −88.0 mV)]. This effect is explained by a shift of the responsiveness of Ih to cAMP toward higher concentrations in TC neurons from WAG/Rij, as revealed by application of 8-bromo-cAMP and the phosphodiesterase inhibitor IBMX. During blockade of adenylyl cyclase activity, Ih activation was similar in the two strains, whereas the difference in cAMP responsiveness persisted, thereby voting against different ambient cAMP levels between strains. Increasing the intracellular cAMP level and shifting Ih activation led to a change from burst to tonic firing mode in WAG/Rij but not in ACI rats. Furthermore, HCN1 expression was significantly increased on mRNA and protein levels, with no changes in HCN2–4 expression. In conclusion, there is an increase in HCN1 expression in the epileptic thalamus, associated with a decrease in cAMP responsiveness of Ih in TC neurons and resulting impairment to control the shift from burst to tonic firing, which, in turn, will prolong burst activity after recruitment of Ih during absence seizures.
Does Political Democracy Enhance Human Development in Developing Countries?
Authors: Tsai Ming‐Chang
Published: May 2006

Abstract.  Despite the considerable progress of human development (HD) in developing countries (DCs) during recent decades, vast differences still remain among such countries. The question thus arises of why these divergences persist. This cross‐national study uses a larger sample of DCs to offer necessary testing of the impact of democracy on HD. This study adopts new measures of democracy featuring majority rule and political contention to estimate their correlation with three physical well‐being indicators as well as with three school enrollment indicators. After controlling for several macro‐level political and economic characteristics (state revenue and economic growth), the regression modeling for recent data from the 1980s and 1990s showed that democracies indeed achieved higher levels on the HD indicators used here. However, democracy was not a powerful predictor of changes in HD scores during the analysis period. Neither central government health or educational spending significantly altered HD. The conclusions offer a plausible explanation of why democracy in DCs failed to sustain its momentum in improving HD.
Anti‐lipopolysaccharide antibodies in acute appendicitis detected by ELISA
Authors: PÉTERFI ZOLTÁN , KOVÁCS KRISZTINA , ANTAL ANDRÁS , KOCSIS BÉLA
Published: May 2006

In acute appendicitis the bowel transmissibility of the intestinal flora increases in relation to inflammation and edema formation. We can therefore observe an immunologic response in patients, which is detectable using different bacteria isolated from the normal intestinal flora. Our aim was to measure this immunologic reaction and to detect the relationship between this response and histologic types of acute appendicitis. Sera from 47 cases, comprising 38 patients suffering from appendicitis and 9 healthy controls, were examined. The sera were taken shortly before appendectomy and 14 days after operation. The antigens were lipopolysaccharides (LPS) extracted from bacteria of normal intestinal flora: Escherichia coli O21, O22, O33, O61, O68, Bacteroides fragilis and an absolute rough mutant: Shigella sonnei Re 4350. Antibodies were detected by ELISA. We showed a direct relationship between severity of appendicitis and registered antibody titer. Both aerobic and anaerobic bacteria play a role in infection in appendicitis. According to our serologic results the synergy of B. fragilis with E. coli from normal flora is more important in the initiation of inflammation, but in the perforation process the role of E. coli seems more important compared to that of B. fragilis.
Changes in dental fluorosis following the cessation of water fluoridation
Authors: Clark D. Christopher , Shulman Jay D. , Maupomé Gerardo , Levy Steven M.
Published: May 2006

Abstract –  Objectives:  To determine changes in the prevalence of dental fluorosis, and in perceptions of aesthetic concerns due to dental fluorosis after water fluoridation ceased.

Methods:  Schoolchildren in second and third grades were examined in 1993–94, 1996–97 and 2002–03 to determine changes in the prevalence of dental fluorosis following fluoridation cessation of the public water supplies in 1992. The Thylstrup–Fejerskov Index (TFI) was used to quantify dental fluorosis. Perceptions of aesthetics were assessed by questionnaires which were sent home to parents. Residence and dental histories were confirmed on all children to determine the extent of exposure to all types of fluorides. Comparisons between the three surveys were used to establish the influence of fluoridated water and other fluoride sources on the occurrence and severity of dental fluorosis. Aesthetic ratings from parents were used to assess the aesthetic conditions of maxillary anterior teeth across the three surveys.

Results:  When fluoride was removed from the water supply in 1992, the prevalence and severity of TFI scores decreased significantly from the 1993–94 survey cycle when compared with the 1996–97 and 2002–03 survey cycles. The use of fluoride supplements and fluoride dentifrice also decreased during this study period. Analyses were unable to determine the influence of these different fluoride exposures on the changes in TFI scores over time. Comparisons of aesthetic ratings from parents between survey cycles failed to show any significant differences.
The effects of fluoride on the nanostructure and surface pK of enamel crystals: an atomic force microscopy study of human and rat enamel
Authors: Robinson Colin , Yamamoto Kyoko , Connell Simon D. , Kirkham Jennifer , Nakagaki Haruo , Smith Alastair D.
Published: May 2006

Atomic force microscopy (AFM) studies have revealed 30–40 nm‐wide regular positively charged bands across maturation‐stage rat enamel crystals. Low pH resolved these into positively charged spherical domains of ≈ 30 nm diameter. Crystal surface pK values from adhesion force titrations were ≈ 6.5. The effect of fluoride on this pK value and on the nanostructure of fluorosed human enamel crystals has not been reported. The nanostructure and surface chemistry (pK) of normal and fluorotic human and of fluoride‐treated rat maturing enamel crystals was examined. Enamel was sectioned and polished, prior to examination, using AFM in height and friction modes. High‐resolution height images revealed 30 nm‐diameter spherical domains within crystals, arranged as layers of hexagons or as a shallow spiral. Fluorotic enamel showed similar, but less well ordered, nanodomains. These could represent an arrangement of original initiation sites or binding sites for modulating matrix proteins. Surface pK was derived from adhesion‐force measurements between functionalized tips (OH or COOH) and crystal surfaces between pH 2 and pH 10. pK values of ≈ 6.5 for normal crystals were reduced to ≈ 5.5 after fluoride treatment. Reduction in surface pK by fluoride might indicate lowered protonation with possible effects on matrix protein binding.
A developmental comparison of matrix metalloproteinase‐20 and amelogenin null mouse enamel
Authors: Bartlett John D. , Skobe Ziedonis , Lee Daniel H. , Wright J. Timothy , Li Yong , Kulkarni Ashok B. , Gibson Carolyn W.
Published: May 2006

Mutations in both the human amelogenin and human matrix metalloproteinase‐20 (MMP20, enamelysin) genes cause amelogenesis imperfecta. Both genes have also been individually deleted from the mouse and each deletion results in defective dental enamel. Here, we compare the stage‐specific progression of enamel development in continuously erupting mouse incisors from amelogenin null and MMP‐20 null mice. Our goal was to closely examine differences in enamel and enamel organ structure between these mice that would allow a better understanding of each protein's function. The predominant feature of the amelogenin null incisors was the late onset of mineral deposition, with little or no protein present within the forming mineral. Conversely, the developing MMP‐20 null incisors had a layer of protein between the apical surface of the ameloblasts and the forming enamel. Furthermore, the protein present within the enamel matrix was disorganized. An analysis of crystal structure demonstrated that the thin amelogenin null enamel was plate‐like, while the MMP‐20 null enamel had a disrupted prism pattern. These results suggest that amelogenin is essential for appositional crystal growth during the early to mid‐secretory stage and for the maintenance of the crystal ribbon structure. They also suggest that MMP‐20 is responsible for enamel matrix organization and for subsequent efficient reabsorption of enamel matrix proteins. Both genes are essential for the generation of full‐thickness enamel containing the characteristic decussating prism pattern.
Proteolysis on maturing enamel surface, as shown by gel‐coating methods
Authors: Takano Yoshiro , Nakano Yukiko , Yamamoto‐Shuda Yoko , Baba Otto , Terashima Tatsuo
Published: May 2006

Degradation of enamel matrix proteins, and their removal during early maturation, is critical for the growth of large enamel crystals in the subsequent processes of enamel maturation. In this study, we sought to demonstrate, using in vivo zymography, the exact sites of proteolysis in maturing enamel and its relationship to the overlying ameloblasts. The maturing enamel surfaces of rat and bovine incisors were exposed and painted either with pre‐exposed autoradiographic emulsion or with densely fluorescein‐conjugated (DQ) gelatin. After a few hours, photographic development of the emulsion revealed alternate black and white banding patterns over the maturing enamel surface. DQ gelatin also revealed similar banding patterns of fluorescent and non‐fluorescent regions. White, powdery areas of emulsion and fluorescent bands of DQ gelatin both corresponded to the areas of ruffle‐ended ameloblasts, at least up to the mid stages of enamel maturation, implicating a predominant contribution of ruffle‐ended ameloblasts in the degradation of enamel matrix proteins. Powdery white bands in autoradiographic emulsion shifted from the areas of ruffle‐ended to smooth‐ended ameloblasts in late maturation in both bovine and rat incisors and were not influenced by proteinase inhibitors or heat inactivation, implicating non‐enzymatic interactions. DQ gelatin, in fact, did not generate any fluorescence in such smooth‐ended ameloblast regions.
Pattern of mineralization after regenerative periodontal therapy with enamel matrix proteins
Authors: Bosshardt Dieter D. , Sculean Anton , Donos Nikolaos , Lang Niklaus P.
Published: May 2006

A derivative (EMD) of enamel matrix proteins (EMPs) is used for periodontal regeneration because EMPs are believed to induce the formation of acellular extrinsic fiber cementum (AEFC). Other reports, however, indicate that EMPs have osteogenic potential. The aim of this study was to characterize the nature of the tissue that forms on the root surface following application of EMD. Ten human teeth affected by periodontitis and scheduled for extraction were treated with EMD. Four to six weeks later, they were extracted and processed for analysis by light microscopy and transmission electron microscopy. Immunocytochemistry with antibodies against bone sialoprotein (BSP) and osteopontin (OPN) was performed to determine the mineralization pattern. The newly formed tissues on the root were thick and contained embedded cells. Small mineralization foci were regularly seen, and large organic matrix patches were occasionally seen, but a distinct mineralization front was lacking. While labeling for BSP was always associated with small mineralization foci and large matrix patches, OPN labeling was seen inconsistently. It is concluded that tissues resembling either cellular intrinsic fiber cementum or a type of bone were observed. The mineralization pattern mostly resembled that found in bone, except for a few areas that exhibited a hitherto undescribed mineralization pattern.
Fluoride down‐regulates the expression of matrix metalloproteinase‐20 in human fetal tooth ameloblast‐lineage cells in vitro
Authors: Zhang Yan , Yan Qiaomei , Li Wu , DenBesten Pamela K.
Published: May 2006

Fluoride is associated with a decrease in the incidence of dental caries, but excessive fluoride intake during tooth enamel formation can result in enamel fluorosis. Fluorosed enamel has increased porosity, which has been related to a delay in the removal of amelogenin proteins as the enamel matures. This delay in protein removal suggests that fluoride may affect either the amount or the activity of enamel matrix proteinases. In this study, we investigated the role of fluoride in the synthesis and secretion of matrix metalloproteinase‐20 (MMP‐20), the proteinase primarily responsible for the initial hydrolysis of amelogenin during the secretory stage of enamel formation. Cultured human fetus tooth organ ameloblast‐lineage cells were exposed to 10 µM fluoride and analyzed for synthesis of MMP‐20. Immunoblotting showed that 10 µM NaF down‐regulated the synthesis of MMP‐20 by 21% compared with control cells, but did not alter the amount of amelogenin or kalikrein‐4 (KLK‐4) synthesized by the cells. Real‐time polymerase chain reaction (PCR) showed that 10 µM NaF down‐regulated MMP‐20 mRNA expression to 28% of the levels found in the non‐treated cells. These in vitro results suggest that fluoride can alter the expression of MMP‐20 by ameloblasts, resulting in a disturbance of the balance between MMP‐20 and its substrate that may contribute to the retention of amelogenins in the formation of fluorosed enamel.
SEM evidence that one ameloblast secretes one keyhole‐shaped enamel rod in monkey teeth
Authors: Skobe Ziedonis
Published: May 2006

Primate enamel is subdivided into inner enamel, having Hunter–Schreger bands, and outer enamel with all rods parallel to each other. Outer inter‐rod enamel may surround each rod, lie between rows of rods, or be absent, as in the ‘keyhole pattern’, which is composed entirely of rods. One theory on the formation of the ‘keyhole’ pattern overlays the hexagonal cross‐sectional shape of four or more ameloblasts over the keyhole shape of the enamel rod. This ignores the likelihood that Tomes processes have a different shape from the cell body, and also ignores the observation that paths of enamel rods sometimes diverge. Scanning electron microscopy (SEM) revealed the keyhole shape of the forming face of monkey enamel. These forming rods were arranged in stepped rows with the head regions in each row separated by the tails of the preceding row. Consequently, each forming face of a rod was surrounded on three sides by previously formed enamel. The apical surface of the Tomes process was shaped exactly like the forming rod face, permitting direct apposition of one rod and one Tomes process. The conclusion was that, in the monkey, each rod of the keyhole enamel configuration is produced by one ameloblast.
Intracellular nanosphere subunit assembly as revealed by amelogenin molecular cross‐linking studies
Authors: Brookes Steven J. , Lyngstadaas Staale Petter , Robinson Colin , Shore Roger C. , Kirkham Jennifer
Published: May 2006

Enamel matrix comprises nanospheres predominantly composed of amelogenin. Studies have shown that recombinant amelogenin forms nanospheres similar to those formedin vivo, but it is unclear exactly how nanospheres assemblein vivo. Are amelogenin monomers secreted into the enamel matrix where they then self‐assemble to form nanospheres, or does nanosphere assembly actually occur intracellularly? The aim of this study was to attempt to answer this question. Rat enamel organs were treated with the bifunctional cross‐linker, dithio bis (succinimidyl propionate) (DSP), which cross‐links primary amines lying in close molecular proximity. The key to this technique is the fact that DSP cross‐links are later sensitive to reductive cleavage. The cross‐linked proteins were first subjected to non‐reducing sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) in the first dimension and then to reducing SDS–PAGE in the second dimension (so‐called diagonal electrophoresis) followed by western blot probing with anti‐amelogenin. The results indicated that intracellular amelogenin monomers are in close neighbor contact, forming complexes comprising up to six individual amelogenin monomers. We suggest that these initial complexes are prefabricated intracellularly before secretion. Once secreted, these prefabricated subunits assemble further to form the mature full‐size nanospheres containing hundreds of individual amelogenins characteristic of enamel matrix.
Self‐assembly and effect on crystal growth of the leucine‐rich amelogenin peptide
Authors: Habelitz Stefan , DenBesten Pamela K. , Marshall Sally J. , Marshall Grayson W. , Li Wu
Published: May 2006

Amelogenins are a unique group of alternatively spliced proteins. While the full‐length amelogenin is known to assemble into nanospheres and alter apatite crystal growth and alignment, the function of the leucine‐rich amelogenin peptide (LRAP) in biomineralization is not understood. This study tested the hypothesis that LRAP self‐assembles into a supramolecular structure and guides crystal growth similarly to the full‐length protein. Synthetic LRAP and recombinant full‐length amelogenin (rH175) were used at different concentrations and either immobilized onto fluoroapatite substrates (FAP) or immersed into saturated calcium‐phosphate solutions. The structure of the assembled protein and the height of apatite crystals formed on the FAP template were determined using atomic force microscopy. Both LRAP and rH175 assembled into nanospheres. LRAP self‐assembly, however, was only observed at concentrations of > 0.5 mg ml−1 and limited to sizes between 5 and 30 nm. Apatite crystal growth was not significantly affected by LRAP, while rH175 accelerated crystal growth by up to 50‐fold. The increased growth rate was only observed when rH175 precipitated at concentrations of > 0.8 mg ml−1. It was concluded that the ability of amelogenins to self‐assemble into nanospheres and to bind to apatite in vitro is not inevitably an indication for the ability to control apatite crystal growth.
Comparison of three methods for enamel protein extraction in different developmental phases of rat lower incisors
Authors: Porto Isabel M. , Line Sérgio R. P. , Laure Helen J. , Gerlach Raquel F.
Published: May 2006

Protein extraction methods [urea, trichloroacetic acid (TCA), and acetic acid] were compared for protein recovery from rat incisor developing enamel in the S phase (intermediate/late secretion), M1 phase (early maturation), M2 phase (intermediate maturation), and M3 phase (final maturation). We compared the protein recoveries with the percentage of enamel matrix dry weight burnt off by incineration. Our results indicate that TCA and urea were equally efficient for the extraction of S‐stage proteins (85% and 90% recovery, respectively), while urea was the best for M1‐stage proteins (92% recovery), and TCA the best for M2‐stage (99% recovery) and M3‐stage (60% recovery) proteins. The other methods yielded less than 30% recovery in comparison to incineration for M2 and M3 stages. The fact that urea extraction works well in the S and M1 stages and not thereafter is probably related to the changes in the proteins during enamel development and the amount of mineral that needs to be dissolved. TCA is the single method that effectively recovered proteins from all developmental stages of the rat incisor enamel.
Effect of Toll‐Like Receptor (TLR) Agonists on TLR and Microbicide Expression in Uterine and Vaginal Tissues of the Mouse
Authors: Soboll Gisela , Schaefer Todd M. , Wira Charles R.
Published: May 2006

Problem

Epithelial cells lining the uterine lumen are the first line of defense against pathogenic microbes. The objective of this study was to examine the expression of Toll‐like receptors (TLRs), defensins and secretory leukocyte protease inhibitor (SLPI) in the mouse uterus and vagina and in primary uterine epithelial cells and to determine whether TLR agonists induce TLR and defensin expression.

Method of study

The mRNA expression of α‐ and β‐defensins (AD1, 2 and 5 and BD1, 2 and 4) and SLPI was examined by real‐time reverse transcriptase‐polymerase chain reaction (RT‐PCR) along with the secretion of macrophage chemotactic protein‐1 (MCP‐1), measured by enzyme‐linked immunosorbent assay.

Results

Expression of TLR1–9 as well as β‐defensins 1, 2 and 4 and SLPI by uterine and vaginal tissues was demonstrated by RT‐PCR. β‐Defensins and SLPI expression was greater in the vagina than in the uterus. Comparison of fresh and polarized uterine epithelial cells indicated that TLR2–6 expression was unaffected by culture. Incubation of polarized epithelial cells with TLR agonists [lipopolysaccharide (LPS), Pam3Cys, Poly (I:C) or PGN] induced TLR5 and TLR9 expression but had no effect on TLR4, defensins or SLPI. Furthermore, exposure to LPS, Pam3Cys, Poly (I:C) or PGN, induced MCP‐1 secretion by polarized epithelial cells in culture.

Conclusion

These results indicate that the uterus and vagina as well as uterine epithelial cells are responsive to bacterial and viral pathogens. Not only do epithelial cells respond to TLR agonists by releasing MCP‐1, which mediates inflammatory responses, but they also influence the expression of selected TLR genes to further enhance innate immune protection.
Bilateral Spigelian hernia treated by two‐layered prolene mesh
Authors: Naik Saleem , Kapoor Sorabh , Sharma Sandesh K. , Varshney Subodh
Published: May 2006

Spigelian hernia is an uncommon variety of abdominal hernias. It has been traditionally treated by tension‐free mesh hernioplasty. We report a rare case of a bilateral Spigelian hernia in an elderly male that was treated by bilateral two‐layeyed prolene mesh hernia system. Rare ventral hernia such as Spigelian hernia with weak abdominal wall can be safely treated by tension‐free mesh repair using bilayered prolene mesh system.
Symptomatic gallbladder agenesis in an elderly woman: Diagnosis and management dilemma
Authors: Ayantunde Abraham Abiodun
Published: May 2006

Gallbladder agenesis is an uncommon clinical entity where there is an isolated congenital absence of the gallbladder and the cystic duct. It is usually asymptomatic and many are not detected. There is, however, increasing diagnosis on account of available new imaging techniques. The symptomatic group typically presents with right upper quadrant pain of biliary colic, nausea and vomiting and obstructive jaundice. I report a case of an elderly woman presenting for the first time with agenesis of the gallbladder and painful obstructive jaundice.
USE OF DISCOVERY CURVES TO ASSESS ABUNDANCE OF HAWAIIAN MONK SEALS
Authors: Baker Jason D. , Harting Albert L. , Johanos Thea C.
Published: May 2006

Abstract

We investigated the pattern of first sighting of individual seals over the course of a field season, or the “discovery curve,” as a means for estimating abundance of the endangered Hawaiian monk seal, Monachus schauinslandi. We empirically derived a criterion to determine whether or not total enumeration had been accomplished at a given site and year. When greater than 100‐h field effort was expended without a new individual being identified, we concluded that total enumeration was likely achieved. To evaluate the potential for estimating abundance through extrapolation of nonlinear asymptotic functions fitted to discovery curves, we conducted simulations under a range of capture probability scenarios, including some based on observed individual variability in monk seal sighting frequencies. We demonstrated that if capture heterogeneity existed among individuals, the fitted asymptotes tended to yield biased estimates of abundance. Moreover, the levels of bias and uncertainty tended to increase inversely with the proportion of the population identified. While extrapolation shows little promise for generating unbiased abundance estimates, discovery curves have practical appeal for determining whether total enumeration has been achieved, and for optimizing field effort allocation. This is especially true for relatively small, closed populations of marked individuals.
General Three-Dimensional Analysis of Transient Elastic Waves in a Multilayered Medium
Authors: Ma Chien-Ching , Lee Genn-Sheng
Published: May 2006

The propagation of transient elastic waves in a three-dimensional multilayered medium subjected to general dynamic loadings is analyzed in this study. One of the objectives of this study is to develop an effective analytical method for determining transient full-field solutions in the multilayered medium subjected to nonaxisymmetric dynamic loadings. The wave field is decomposed into two parts; one is the P-SV system of waves and the other is the SH system, each of which propagates independently in a horizontally layered medium. A simple relationship between solutions of two- and three-dimensional problems in the Fourier transform domain is also presented. A matrix solution in the triple transform domain is obtained by Brownwich expansion and the inverse transform is inverted by Cagniard’s method. The matrix representation of the solution can be easily used to calculate the transient response of the multilayered medium without tracing the ray path manually. The formulas presented in this study enable us to calculate the long-time transient responses of the multilayered medium for three-dimensional configuration. The theoretical transient solution for a layer overlaying a half-space subjected to an arbitrarily oriented point force is presented in detail. The numerical calculations are compared with experimental measurements for the surface displacement response on a plate and a layer overlaying a half-space subjected to an axisymmetric point force. The numerical investigation is also carried out for nonaxisymmetric loading problem of a layer overlaying a half-space.
Subgrid Scale Modeling
of Turbulence for the Dynamic Procedure Using Finite Difference Method and Its Assessment on the
Thermally Stratified Turbulent Channel Flow
Authors: Tsubokura Makoto
Published: May 2006

Previously proposed methods for subgrid-scale (SGS) stress modeling were re-investigated and extended to SGS heat-flux modeling, and various anisotropic and isotropic eddy viscosity/diffusivity models were obtained. On the assumption that they are used in a finite-difference (FD) simulation, the models were constructed in such a way that they are insensitive to numerical parameters on which calculated flows are strongly dependent in the conventional Smagorinsky model. The models obtained, as well as those previously proposed, were evaluated a priori in a stably stratified open channel flow, which is considered to be a challenging application of large eddy simulation and suitable for testing both SGS stress and heat-flux models. The most important feature of the models proposed is that they are insensitive to the discretized test filtering parameter required in the dynamic procedure of Germano et al. (1991, Phys. Fluids, 3, pp. 1760–1765) in FD simulation. We also found in SGS heat-flux modeling that the effect of the grid (resolved)-scale (GS) velocity gradient plays an important role in the estimation of the streamwise heat flux, and an isotropic eddy diffusivity model with the effect of the GS velocity is proposed.
Unsteady Tip Leakage Vortex Cavitation Originating From the Tip Clearance of an Oscillating Hydrofoil
Authors: Murayama Masahiro , Yoshida Yoshiki , Tsujimoto Yoshinobu
Published: May 2006

Tip leakage vortex cavitations originating from the tip clearance of an oscillating hydrofoil were observed experimentally. It was found that the delay between the unsteady and the steady-state results of the tip leakage vortex cavitation increase, and that the maximum cavity size decreases when the reduced oscillating frequency increases. To simulate the unsteady characteristics of tip leakage vortex cavitation, a simple calculation based on slender body approximation was conducted taking into account the effect of cavity growth. The calculation and experimental results of the cavity volume fluctuation were found to be in qualitative agreement.
Numerical Simulation and Mixing Study of Pseudoplastic Fluids in an Industrial Helical Static Mixer
Authors: Rahmani Ramin K. , Keith Theo G. , Ayasoufi Anahita
Published: May 2006

Static mixers are increasingly being used to perform a variety of mixing tasks in industries, ranging from simple blending to complex multiphase reaction systems. Use of static mixers to process non-Newtonian fluids is quite common. Data on the pressure drop of non-Newtonian fluids in static mixers and the degree of mixing of materials through the mixer are very useful in the design and engineering application of these tools. This paper extends a previous study by the authors on an industrial helical static mixer and illustrates how static mixing processes of single-phase viscous liquids can be simulated numerically. A further aim is to provide an improved understanding of the flow pattern of pseudoplastic liquids through the mixer. A three-dimensional finite volume simulation is used to study the performance of the mixer. The flow velocities, pressure drops, etc., are calculated for various flow rates, using the Carreau and the power law models for non-Newtonian fluids. The numerical predictions by these two models are compared to existing experimental data. Also, a comparison of the mixer performance for both Newtonian and pseudoplastic fluids is presented. The effects of the Reynolds number of the flow and also properties of pseudoplastic fluids on the static mixer performance have been studied. It is shown that for the materials studied here, the fluid type is not effective on the degree of mixing. It is also shown that the fluid type has a major impact on the pressure drop across the mixer.
A Reconstruction Method for the Flow Past an Open Cavity
Authors: Podvin B. , Fraigneau Y. , Lusseyran F. , Gougat P.
Published: May 2006

In this paper we propose a method to reconstruct the flow at a given time over a region of space using partial instantaneous measurements and full-space proper orthogonal decomposition (POD) statistical information. The procedure is tested for the flow past an open cavity. 3D and 2D POD analysis are used to characterize the physics of the flow. We show that the full 3D flow can be estimated from a 2D section at an instant in time provided that some 3D statistical information—i.e., the largest POD modes of the flow— is made available.
Large-Eddy Simulation
of Reacting Turbulent Flows in Complex
Geometries
Authors: Mahesh K. , Constantinescu G. , Apte S. , Iaccarino G. , Ham F. , Moin P.
Published: May 2006

Large-eddy simulation (LES) has traditionally been restricted to fairly simple geometries. This paper discusses LES of reacting flows in geometries as complex as commercial gas turbine engine combustors. The incompressible algorithm developed by Mahesh et al. (J. Comput. Phys., 2004, 197, 215–240) is extended to the zero Mach number equations with heat release. Chemical reactions are modeled using the flamelet/progress variable approach of Pierce and Moin (J. Fluid Mech., 2004, 504, 73–97). The simulations are validated against experiment for methane-air combustion in a coaxial geometry, and jet-A surrogate/air combustion in a gas-turbine combustor geometry.
Tracking moving objects with megavoltage portal imaging: A feasibility studya)
Authors: Meyer Juergen , Richter Anne , Baier Kurt , Wilbert Juergen , Guckenberger Matthias , Flentje Michael
Published: May 2006

Four different algorithms were investigated with the aim to determine their suitability to track an object in conventional megavoltage portal images. The algorithms considered were the mean of the sum of squared differences (MSSD), mutual information (MI), the correlation ratio (CR), and the correlation coefficient (CC). Simulation studies were carried out with various image series containing a rigid object of interest that was moved along a predefined trajectory. For each of the series the signal‐to‐noise ratio (SNR) was varied to compare the performance of the algorithms under noisy conditions. For a poor SNR of the mean tracking error was 2.4, 6.5, 39.0, and for MSSD, CC, CR and MI, respectively, with a standard deviation of 1.9, 12.9, 19.5, and , respectively. The size of a pixel was . These results improved to 1.1, 1.3, 1.3, and , respectively, with a standard deviation of 0.6, 0.8, 0.8, and , respectively, when a mean filter was applied to the images prior to tracking. The implementation of MSSD into existing in‐house software demonstrated that, depending on the search range, it was possible to process between 2 and , making this approach capable of real‐time applications. In conclusion, the best geometric tracking accuracy overall was obtained with MSSD, followed by CC, CR, and MI. The simplest and best algorithm, both in terms of geometric accuracy as well as computational cost, was the MSSD algorithm and was therefore the method of choice.
Defective Lipolysis and Altered Energy Metabolism in Mice Lacking Adipose Triglyceride Lipase
Authors: Haemmerle Guenter , Lass Achim , Zimmermann Robert , Gorkiewicz Gregor , Meyer Carola , Rozman Jan , Heldmaier Gerhard , Maier Robert , Theussl Christian , Eder Sandra , Kratky Dagmar , Wagner Erwin F. , Klingenspor Martin , Hoefler Gerald , Zechner Rudolf
Published: May 2006

Fat tissue is the most important energy depot in vertebrates. The release of free fatty acids (FFAs) from stored fat requires the enzymatic activity of lipases. We showed that genetic inactivation of adipose triglyceride lipase (ATGL) in mice increases adipose mass and leads to triacylglycerol deposition in multiple tissues. ATGL-deficient mice accumulated large amounts of lipid in the heart, causing cardiac dysfunction and premature death. Defective cold adaptation indicated that the enzyme provides FFAs to fuel thermogenesis. The reduced availability of ATGL-derived FFAs leads to increased glucose use, increased glucose tolerance, and increased insulin sensitivity. These results indicate that ATGL is rate limiting in the catabolism of cellular fat depots and plays an important role in energy homeostasis.
Signal Recognition Particle Receptor Exposes the Ribosomal Translocon Binding Site
Authors: Halic Mario , Gartmann Marco , Schlenker Oliver , Mielke Thorsten , Pool Martin R. , Sinning Irmgard , Beckmann Roland
Published: May 2006

Signal sequences of secretory and membrane proteins are recognized by the signal recognition particle (SRP) as they emerge from the ribosome. This results in their targeting to the membrane by docking with the SRP receptor, which facilitates transfer of the ribosome to the translocon. Here, we present the 8 angstrom cryo–electron microscopy structure of a “docking complex” consisting of a SRP-bound 80
S
ribosome and the SRP receptor. Interaction of the SRP receptor with both SRP and the ribosome rearranged the S domain of SRP such that a ribosomal binding site for the translocon, the L23e/L35 site, became exposed, whereas Alu domain–mediated elongation arrest persisted.
Diversity and Distribution of Marine Microbial Eukaryotes in the Arctic Ocean and Adjacent Seas
Authors: Lovejoy C. , Massana R. , Pedrós-Alió C.
Published: May 2006

We analyzed microbial eukaryote diversity in perennially cold arctic marine waters by using 18S rRNA gene clone libraries. Samples were collected during concurrent oceanographic missions to opposite sides of the Arctic Ocean Basin and encompassed five distinct water masses. Two deep water Arctic Ocean sites and the convergence of the Greenland, Norwegian, and Barents Seas were sampled from 28 August to 2 September 2002. An additional sample was obtained from the Beaufort Sea (Canada) in early October 2002. The ribotypes were diverse, with different communities among sites and between the upper mixed layer and just below the halocline. Eukaryotes from the remote Canada Basin contained new phylotypes belonging to the radiolarian orders Acantharea, Polycystinea, and Taxopodida. A novel group within the photosynthetic stramenopiles was also identified. One sample closest to the interior of the Canada Basin yielded only four major taxa, and all but two of the sequences recovered belonged to the polar diatom
Fragilariopsis
and a radiolarian. Overall, 42% of the sequences were <98% similar to any sequences in GenBank. Moreover, 15% of these were <95% similar to previously recovered sequences, which is indicative of endemic or undersampled taxa in the North Polar environment. The cold, stable Arctic Ocean is a threatened environment, and climate change could result in significant loss of global microbial biodiversity.
Horizontal Gene Transfer of P
IB
-Type ATPases among Bacteria Isolated from Radionuclide- and Metal-Contaminated Subsurface Soils
Authors: Martinez Robert J. , Wang Yanling , Raimondo Melanie A. , Coombs Jonna M. , Barkay Tamar , Sobecky Patricia A.
Published: May 2006

Aerobic heterotrophs were isolated from subsurface soil samples obtained from the U.S. Department of Energy's (DOE) Field Research Center (FRC) located at Oak Ridge, Tenn. The FRC represents a unique, extreme environment consisting of highly acidic soils with cooccurring heavy metals, radionuclides, and high nitrate concentrations. Four hundred isolates obtained from contaminated soil were assayed for heavy metal resistance, and a smaller subset was assayed for tolerance to uranium. The vast majority of the isolates were gram-positive bacteria and belonged to the high-G+C- and low-G+C-content genera
Arthrobacter
and
Bacillus
, respectively. Genomic DNA from a randomly chosen subset of 50 Pb-resistant (Pb
r
) isolates was amplified with PCR primers specific for P
IB
-type ATPases (i.e.,
pbrA/cadA/zntA
). A total of 10
pbrA/cadA/zntA
loci exhibited evidence of acquisition by horizontal gene transfer. A remarkable dissemination of the horizontally acquired P
IB
-type ATPases was supported by unusual DNA base compositions and phylogenetic incongruence. Numerous Pb
r
P
IB
-type ATPase-positive FRC isolates belonging to the genus
Arthrobacter
tolerated toxic concentrations of soluble U(VI) (UO
2
2+
) at pH 4. These unrelated, yet synergistic, physiological traits observed in
Arthrobacter
isolates residing in the contaminated FRC subsurface may contribute to the survival of the organisms in such an extreme environment. This study is, to the best of our knowledge, the first study to report broad horizontal transfer of P
IB
-type ATPases in contaminated subsurface soils and is among the first studies to report uranium tolerance of aerobic heterotrophs obtained from the acidic subsurface at the DOE FRC.