bluuebunny/crossref_metadata_2025 huggingface dataset:
Elimination of the overburden response from multicomponent source and receiver seismic data, with source designature and decomposition into PP-, PS-, SP-, and SS-wave responses
Authors: Holvik Egil , Amundsen Lasse
Published: April 2005

This paper shows that Betti's reciprocity theorem gives an integral equation procedure to eliminate from the physical multicomponent-source, multicomponent-receiver seismic measurements the effect of the physical source radiation pattern and the response of the physical overburden (that is, the medium above the receiver plane). The physical multicomponent sources are assumed to be orthogonally aligned anywhere above the multicomponent-receiver depth level. Other than the position of the sources, no source characteristics are required. The method, denoted the Betti designature/elastic demultiple, has the following additional characteristics: it preserves primary amplitudes while eliminating all waves scattered from the overburden; it requires no knowledge of the medium below the receiver level; it requires no knowledge of the medium above the receiver level; it requires information only of the local density and elastic wave propagation velocities at the receiver level to decompose the physical seismic measurements into upgoing and downgoing waves. Following the Betti designature/elastic demultiple step is an elastic wavefield decomposition step that decomposes the data into PP-, PS-, SP-, and SS-wave responses that would be recorded from idealized compressional-wave and shear-wave sources and receivers. The combined elastic wavefield decomposition on the source and receiver side gives data equivalent to data from a hypothetical survey with overburden absent, with single-component compressional and shear-wave sources, and single-component compressional and shear-wave receivers. When the medium is horizontally layered, the Betti designature/elastic demultiple scheme followed by the elastic source-receiver decomposition scheme greatly simplifies and is conveniently implemented as deterministic multidimensional deconvolution and elastic source-receiver wavefield decomposition of common-source gathers (or common-receiver gathers when source array variations are negligible). Betti designature/elastic demultiple followed by source-receiver wavefield decomposition applies to three different seismic experiments: a 9-component (9C) land seismic experiment, a 12-component (12C) ocean-bottom seismic experiment, and an 18-component (18C) borehole seismic experiment. For the land and ocean-bottom seismic experiments, an additional geophone should be deployed below the zero-offset geophone to predict the source-induced vertical traction vector at the source location. A numerical example for the 12C ocean-bottom seismic experiment over a horizontally layered medium validates the Betti designature/elastic demultiple scheme.
Energy balance of a drill-bit seismic source, part 2: Drill-bit versus conventional seismic sources
Authors: Poletto Flavio
Published: April 2005

The radiation properties of a downhole drill-bit seismic source are related to the amplitude and frequency of the forces exerted by the working bit. The main vibration modes of roller-cone and polycrystalline diamond compact (PDC) bits are investigated under different drilling conditions. The analysis includes vibrations produced by teeth indention, multilobed patterns, bouncing with periodic and random effects, single-cutter forces, stick-slip and whirling effects, mud-pressure modulation forces, and bit wear. Drill-bit radiation properties are calculated using the results obtained in part 1 of this paper and are numerically compared to the radiation of conventional vertical seismic profiling (VSP) sources.
History of Intramural Clinical Research at the National Institute of Child Health and Human Development (NICHD)
Authors: LORIAUX D LYNN
Published: April 2005

Abstract: This article reviews the beginnings of the NICHD intramural clinical research program; it focuses on three men, Roy Hertz, Mort Lipsett, and Griff Ross, who were instrumental in providing the intramural research program with the vision and character seen today.
Mutations in the Synthesis and Action of Estrogen: The Critical Role in the Male of Estrogen on Pubertal Growth, Skeletal Maturation, and Bone Mass
Authors: GRUMBACH MELVIN M.
Published: April 2005

Abstract: The discovery of males with mutations in CYP19, the gene that encodes aromatase, the enzyme catalyzing the final step in the conversion of androgen to estrogen, and of a man with a mutation in the estrogen receptor α gene has led to increasing recognition of the critical role of estrogen in the male. The diverse roles of estrogen in the male, both circulating and locally synthesized, is supported by extensive studies in male mice generated with disruption of the aromatase gene or the genes encoding the α‐ and β‐estrogen receptor. This presentation focuses on the crucial role of estradiol in the human male on the pubertal growth spurt, skeletal maturation and the cessation of linear growth, and the accrual of bone mass.
An Update of Congenital Adrenal Hyperplasia
Authors: NEW MARIA I.
Published: April 2005

Abstract: Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders caused by mutations that encode for enzymes involved in one of the various steps of adrenal steroid synthesis. These defects result in the absence or the decreased synthesis of cortisol from its cholesterol precursor. The anterior pituitary secretes excess adrenocorticotrophic hormone (ACTH) via feedback regulation by cortisol, which results in overstimulation of the adrenals and causes hyperplasia. Symptoms due to CAH can vary from mild to severe depending on the degree of ensymatic defect. In the classical form of CAH, there is a severe enzymatic defect owing to mutations in the CYP21 gene. Classically affected female fetuses undergo virilization of the genitalia prenatally and present with genital ambiguity at birth; however, prenatal treatment of CAH with dexamethasone to prevent ambiguity has been successfully utilized for over a decade. In the less severe, late‐onset form of CAH, prenatal virilization does not occur. The milder enzyme deficiency was termed nonclassical 21‐hydroxylase deficiency (NC21OHD) in 1979 and was later found to be the most common autosomal recessive disorder in humans. Disease frequency of NC21OHD varies between ethnic groups with the highest ethnic‐specific disease frequency in Ashkenazi Jews at 1/27. NC21OHD is diagnosed by serum elevations of 17‐OHP that plot on a nomogram between the range for unaffected individuals and levels observed for classical CAH and is typically confirmed with molecular genetic analysis. Similar to classical CAH, nonclassical 21‐hydroxylase deficiency may cause premature development of pubic hair, advanced bone age, acelerated linear growth velocity and diminished final height in both males and females. Severe cystic acne has also been attributed to nonclassical CAH. Women may present with symptoms of androgen excess, including hirsutism, temporal baldness, and infertility. Menarche in females may be normal or delayed and secondary amenorrhea is a frequent occurence. Polycystic ovary syndrome may also be seen in these patients. In males, early beard growth, acne, and growth spurt may prompt the diagnosis of NC21OHD. Although many males appear to be asymptomatic, they may present with oligozoospermia or diminished fertility. Individuals presenting to dermatology and infertility clinics with symptoms of hyperandrogenemia are rarely screened for NC21OHD. However, with hormonal and molecular genetic screening, previously undiagnosed patients may be identified and can therefore receive glucocorticoid treatment, which has been shown to reverse symptoms within 3 months.
Developmental Genetics of Drosophila
Authors: LEWIS EDWARD B.
Published: April 2005

Abstract: Drosophila melanogaster is one of the most valuable organisms in biological research, particularly in the areas of genetics and developmental biology. Drosophila has been used as a model organism in research for almost a century. The organism is easy to breed and has a short life cycle, making it ideal for the study of genetic mutations. The importance to human health and development lies in the homology of Drosophila genes to those in man, e.g., the homeobox gene complex.
Structure and Function of Glutamate Receptors
Authors: MAYER MARK
Published: April 2005

Abstract: Understanding how glutamate receptors, a group of molecules that mediate information between neurons in the brain, work at the molecular level has been the focus of my research. The key role of glutamate receptors is to mediate excitatory synaptic transmission throughout the brain and spinal cord. To understand the mechanisms by which this occurs requires a molecular understanding of the receptor proteins. Our experimental approach required breaking down the receptor into smaller assemblies that are easier to work with. We ended up, after a few years, with the first molecular model for how ion channel gating occurs.
Temperament and Early Experience Form Social Behavior
Authors: FOX NATHAN A.
Published: April 2005

Abstract: Individual differences in the way persons respond to stimulation can have important consequences for their ability to learn and their choice of vocation. Temperament is the study of such individual differences, being thought of as the behavioral style of an individual. Common to all approaches in the study of temperament are the notions that it can be identified in infancy, is fairly stable across development, and influences adult personality. We have identified a specific temperament type in infancy that involves heightened distress to novel and unfamiliar stimuli. Infants who exhibit this temperament are likely, as they get older, to display behavioral inhibition—wariness and heightened vigilance of the unfamiliar—particularly in social situations. Our work has also described the underlying biology of this temperament and has linked it to neural systems supporting fear responses in animals. Children displaying behavioral inhibition are at‐risk for behavioral problems related to anxiety and social withdrawal.
Development of the Home Pregnancy Test
Authors: VAITUKAITIS JUDITH L.
Published: April 2005

Abstract: The home pregnancy testworks by measuring human chorionic gonadotropin (hCG) hormone in urine. This hormone was initially studied in NICHD intramural laboratories as a reliable marker of certain tumors. Refinement of the assay for hCG detection to enhance specificity enabled its ready application to pregnancy detection.
Development of the Pill
Authors: GARCÍA CELSO‐RAMÓN
Published: April 2005

Abstract: The history of development of the first oral contraceptive reveals the coalescence of scientific and social forces in the late 1950s that led to his major advance in reproductive freedom for women. Improved knowledge of basic reproductive endocrinology, the development of oral compounds by pharmaceutical companies, and careful clinical trials to document efficacy each played pivotal roles in the story. In addition to industry, the National Institute of Child Health and Human Development and the U.S. Food and Drug Administration provided the research and regulatory support structures to nurture the field along its ultimately highly successful path. Still, it remains important to note that more than 500,000 women die each year from complications of child‐bearing, a problem that is particularly acute in Africa. A significant portion of this mortality would be prevented by better knowledge of and access to oral contraceptives.
Diagnostic Performance of Nanoparticle-Enhanced Magnetic Resonance Imaging in the Diagnosis of Lymph Node Metastases in Patients With Endometrial and Cervical Cancer
Authors: Rockall Andrea G. , Sohaib Syed A. , Harisinghani Mukesh G. , Babar Syed A. , Singh Naveena , Jeyarajah Arjun R. , Oram David H. , Jacobs Ian J. , Shepherd John H. , Reznek Rodney H.
Published: April 2005

Purpose

Lymph node metastases affect management and prognosis of patients with gynecologic malignancies. Preoperative nodal assessment with computed tomography or magnetic resonance imaging (MRI) is inaccurate. A new lymph node–specific contrast agent, ferumoxtran-10, composed of ultrasmall particles of iron oxide (USPIO), may enhance the detection of lymph node metastases independent of node size. Our aim was to compare the diagnostic performance of MRI with USPIO against standard size criteria.

Methods

Forty-four patients with endometrial (n = 15) or cervical (n = 29) cancer were included. MRI was performed before and after administration of USPIO. Two independent observers viewed the MR images before lymph node sampling. Lymph node metastases were predicted using size criteria and USPIO criteria. Lymph node sampling was performed in all patients.

Results

Lymph node sampling provided 768 pelvic or para-aortic nodes for pathology, of which 335 were correlated on MRI; 17 malignant nodes were found in 11 of 44 patients (25%). On a node-by-node basis, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) by size criteria were 29%*, 99%, 56%, and 96%, and by USPIO criteria (reader 1/reader 2) were 93%/82%* (*P = .008/.004), 97%/97%, 61%/59%, and 100%/99%, respectively (where [*] indicates the statistical difference of P = x/x between the two results marked by the asterisk). On a patient-by-patient basis, sensitivity, specificity, PPV, and NPV by size criteria were 27%*, 94%, 60%, and 79%, and by USPIO criteria (reader 1/reader 2) were 100%/91%* (*P = .031/.06), 94%/87%, 82%/71%, and 100%/96%, respectively. The κ statistic was 0.93.

Conclusion

Lymph node characterization with USPIO increases the sensitivity of MRI in the prediction of lymph node metastases, with no loss of specificity. This may greatly improve preoperative treatment planning.
Efficient Method for the Lactonization of ω-Hydroxycarboxylic Acids with Di-2-thienyl Carbonate by the Promotion of Catalytic Amounts of DMAP and Hf(OTf)4
Authors: Oohashi Yoshiaki , Fukumoto Kentarou , Mukaiyama Teruaki
Published: April 2005

An efficient method for the synthesis of macrolides from ω-hydroxycarboxylic acids is established by using an equimolar amount of di-2-thienyl carbonate (2-DTC) and catalytic amounts of 4-(dimethylamino)pyridine (DMAP) and group 4 metal triflates such as hafnium(IV) trifluoromethanesulfonate (Hf(OTf)4).
Recuperation and improvement of chromosome preparations stained with silver nitrate
Authors: Sanchez S. , Cano J. , Fenocchio A.S.
Published: April 2005

Both periodic acid and photographic reagents have been used to remove the silver nitrate residues from cytological preparations. We used potassium ferricyanide to remove AgNO3 salts in cases of excessive chromosome impregnation. This method produced partial decolorization, with contrast enhancement. Counterstaining with Giemsa also promoted a better contrast between chromosome arms and NORs, which were preserved and retained a dark color. Application of this procedure to chromosome preparations treated sequentially for CBG banding/AgNO3 staining promoted complete decolorization of C+ regions, leading to "reverse" C-banding, generally with high contrast.
Genetic control of characters associated with bean golden mosaic geminivirus resistance in Phaseolus vulgaris L.
Authors: Pessoni Luis Alberto , Zimmermann Maria José de O. , Faria Josias Corrêa de
Published: April 2005

Bean golden mosaic is the most important viral disease of the bean crop (Phaseolus vulgaris L.) in Latin America. The genetics of resistance to a Brazilian strain of bean golden mosaic virus (BGMV), was studied in a 4 x 4 diallel cross without reciprocals, among the parental genotypes DOR 303, EMGOPA 201 Ouro, Carnaval, and Redlands Greenleaf C. Seedlings of the four parents, six F1 hybrids, 12 backcrosses, and F2 generations for each combination were inoculated on the eighth day after sowing by exposure to a viruliferous whitefly (Bemisia tabaci Genn.) population for 24 h, in a glasshouse, prior to transplantation to field conditions. The full set of two parents, F1, F2 and respective backcrosses for each combination was considered to be a family. Data were recorded and analyzed for foliar yellowing, plant dwarfing, and pod malformation, using a randomized block design, with two replications. Weighted generation mean analysis was performed for each of the six families. An additive gene action model was significant for the three characteristics evaluated. On the other hand, non-additive gene action had greater absolute value in most cases. Resistance to foliar yellowing conferred by genes from DRO 303 was highly heritable and was expressed equally well in the different genetic backgrounds evaluated. Such resistance may be oligogenic. Broad- and narrow-sense heritabilities were relatively high for all response traits. The three traits studied were all positively correlated, indicating that they can be simultaneously selected for enhancement. The highest correlation coefficient was obtained for dwarfing x pod malformation.
Interphase cytogenetics using fluorescence in situ hybridization: an overview of its application to diffuse and solid tissue
Authors: Hackel Christine , Varella-Garcia Marileila
Published: April 2005

Interphase cytogenetics, utilizing fluorescence in situ hybridization (FISH) techniques, has been successfully applied to diffuse and solid tissue specimens. Most studies have been performed on isolated cells, such as blood or bone marrow cells; a few have been performed on cells from body fluids, such as amniotic fluid, urine, sperm, and sputum. Mechanically or chemically disaggregated cells from solid tissues have also been used as single cell suspensions for FISH. Additionally, intact organized tissue samples represented by touch preparations or thin tissue sections have been used, especially in cancer studies. Advantages and pitfalls of application of FISH methodology to each type of specimen and some significant biological findings achieved are illustrated in this overview.
Effect of taxol on chromosome aberrations induced by gamma radiation or by doxorubicin in Chinese hamster ovary cells
Authors: Dias Francisca da Luz , Antunes Lusânia M.G. , Takahashi Catarina S.
Published: April 2005

Combined therapy with radiation and chemotherapy has being increasingly used in cancer treatment. The effect of combinations of taxol (0.08 mug/ml) with doxorubicin (DXR, 0.5 or 1.0 mug/ml) or gamma radiation (20 or 40 cGy) was examined in two different treatment schedules (pretreatment or simultaneous treatment) using Chinese hamster ovary (CHO) cells treated at the G2 phase of the cell cycle. The results showed that taxol did not have a radiosensitizing effect on the chromosomal aberrations induced by gamma radiation nor did it have a potentiating effect on the chromosomal aberrations induced by DXR in CHO cells treated in the G2 phase of the cell cycle
Plant height reduction in populations of triticale (X triticosecale Wittmack) by induced mutations and artificial crosses
Authors: Pandini Fábio , Carvalho Fernando Irajá Félix de , Barbosa Neto José Fernandes
Published: April 2005

Induced mutations by gamma radiation (0, 5, 10, 20 and 40 kR doses) and reciprocal crosses were tested as mechanisms of enhancing genetic variability for plant height in two triticale cultivars, BR4 and EMBRAPA18. The reciprocal crosses and all doses of radiation showed similar increase in genetic amplitude for this trait, being suitable for increasing variability in breeding programs. Genotypes showed different responses as the gamma ray doses were increased, expressing shorter plant height. The decision of using induced mutations or artificial crosses depends on the resources available and the selection method to be used
Transient expression of a reporter gene introduced by bioballistic bombardment into Racosperma mangium (Leguminosae family) tissues
Authors: Quoirin M. , Aragão F. , Rech E. , De Oliveira D.E.
Published: April 2005

We report on an assay of direct transfer of DNA into calli and seeds of Racosperma (ex-Acacia) mangium, using a bioballistic method. We observed transient expression of the GUS gene in the treated tissues
Reproductive isolation between Anastrepha bistrigata and A. striata (Diptera, Tephritidae)
Authors: Selivon Denise , Morgante João S.
Published: April 2005

The reproductive isolation between two closely related species, Anastrepha bistrigata and A. striata, was studied in the laboratory. Interespecific copulation attempts were observed, but examination of the spermathecae showed that sperm transference did not occur, even after a prolonged period of contact between the mating pairs. These results indicate prezygotic isolation. The analysis of the hourly distribution of mating activities under laboratory conditions, here described for the first time for A. bistrigata, clearly showed differences for the two species, the activities being concentrated in the afternoon period for A. striata and in the morning for A. bistrigata
Molecular cloning of exons II and III of the a-globin major gene from Odontophrynus americanus 2n and 4n (Amphibia, Anura)
Authors: Acedo Maria Dolores P. , Paranhos-Baccalà Gláucia , Denoya Claudio D. , Ruiz Itamar R.G.
Published: April 2005

The a-globin major genes from diploid and tetraploid Odontophrynus americanus were studied using PCR-based technology. The cloned and sequenced amplified fragments were shown to contain most of the exon II sequences as well as the whole exon III sequence of the a-globin gene. Unexpectedly, intron 2 was entirely absent in the amplified fragments of both 2n and 4n origin. High conservation was observed among the obtained sequences when compared to corresponding sequences from human and Xenopus laevis origin. The possibility that these sequences might be pseudogenes is raised
Milk protein polymorphisms in Brazilian Zebu cattle
Authors: Silva Ivana Tramontina da , Del Lama Marco Antonio
Published: April 2005

Five bovine milk protein polymorphisms were studied in Zebuine cattle raised in Brazil, through horizontal electrophoresis on starch gel containing urea and 2-mercaptoethanol, using basic and acidic buffer systems. Allelic frequencies for a-La, b-Lg, aS1-Cn, b-Cn and k-Cn loci were estimated in six Gyr herds (N = 283), six Guzerat herds (N = 205), one Nelore herd (N = 17) and one Sindi herd (N = 22), all from São Paulo or Minas Gerais State, Brazil. Genotypic frequencies observed for each locus and breed studied are in accordance with the assumption of genetic equilibrium, demonstrating absence of high inbreeding levels for the breeds tested. The FST value found indicated significant genetic differentiation among breeds; however, the Gyr and Guzerat herds showed significantly different gene frequencies. Genetic distance estimates among zebuine breeds studied and the Holstein breed, taken as a reference for a taurine breed, showed strong differences between these two racial groups
Chromosome study in two Aratinga species (A. guarouba and A. acuticaudata) (Psittaciformes)
Authors: Goldschmidt Beatriz , Nogueira Denise M. , Monsores Denise W. , Souza Lúcia M.
Published: April 2005

The karyotypes of two species of Psittacidae of the genus Aratinga, Aratinga guarouba and A. acuticaudata were studied for the first time. The metaphases were obtained using a short term culture of feather pulp. These karyotypes are compared with others of the genus and their karyological relationships in the Psittaciformes are discussed
Correlation between high molecular weight gluten subunits composition and bread-making quality in Brazilian wheat
Authors: Schuster Ivan , Souza Moacil Alves de , Cardoso Antônio Américo , Sediyama Carlos Sigueyuki , Moreira Maurílio Alves
Published: April 2005

Bread-making quality is one of the most important targets in the genetic improvement of wheat. Although extensive analyses of quality traits such as farinography, sodium dodecyl sulfate (SDS) sedimentation, alveography, and baking are made in breeding programs, these analyses require high amounts of seeds which are obtained only in late generations. In this experiment the statistical correlations between the high molecular weight subunit of glutenin and bread-making quality measured by alveograph, farinograph and SDS sedimentation were evaluated. Seventeen wheat genotypes were grown under the same conditions, each producing about 1 kg of seeds for the evaluations. The high molecular weight (HMW) glutenin subunits were analyzed by SDS-PAGE. Statistical correlations were highly significant between HMW glutenin subunits and alveograph and SDS sedimentation. These results indicate the possibility of manipulating major genes for wheat seed quality by coupling traditional breeding with non-destructive single seed analysis. Only half seed is necessary to perform the SDS-PAGE analysis. Therefore, the other half seed can be planted to generate the progeny. Seed yield and SDS sedimentation were statistically correlated, indicating the possibility of simultaneous selection for both traits
Using the best linear predictor (BLP) in the selection between and among half-sib progenies of the CMS-39 maize population
Authors: Pacheco Cleso Antônio Patto , Ribeiro Júnior José Ivo , Cruz Cosme Damião
Published: April 2005

Data of corn ear production (kg/ha) of 196 half-sib progenies (HSP) of the maize population CMS-39 obtained from experiments carried out in four environments were used to adapt and assess the BLP method (best linear predictor) in comparison with to the selection among and within half-sib progenies (SAWHSP). The 196 HSP of the CMS-39 population developed by the National Center for Maize and Sorghum Research (CNPMS-EMBRAPA) were related through their pedigree with the recombined progenies of the previous selection cycle. The two methodologies used for the selection of the twenty best half-sib progenies, BLP and SAWHSP, led to similar expected genetic gains. There was a tendency in the BLP methodology to select a greater number of related progenies because of the previous generation (pedigree) than the other method. This implies that greater care with the effective size of the population must be taken with this method. The SAWHSP methodology was efficient in isolating the additive genetic variance component from the phenotypic component. The pedigree system, although unnecessary for the routine use of the SAWHSP methodology, allowed the prediction of an increase in the inbreeding of the population in the long term SAWHSP selection when recombination is simultaneous to creation of new progenies.
Identification of reciprocal hybrids in citrus by the broadness of the leaf petiole wing
Authors: Ballve Rosa M.L. , Medina-Filho Herculano Penna , Bordignon Rita
Published: April 2005

Broadness of leaf petiole wing (WB) was investigated as a morphological marker for screening hybrids of the very narrow-winged species Citrus limonia and C. sunki with broad-winged species C. aurantium and C. sinensis. Controlled polinizations produced over 500 reciprocal hybrids with potential in the ongoing rootstock breeding program identified by the Pgi-1 and Prxa-1 isozyme loci. Measurement ratios WB/leaf length, WB/leaf broadness and WB/petiole length identified 86 to 91% of the reciprocal hybrids produced. However, visual classification of WB was an equally efficient but much easier and faster method. It can be very useful in breeding programs when large number of plants have to be screened or when isozyme, RFLP or RAPD laboratories are not available.
Production of recombinant antigens in plants for animal and human immunization - a review
Authors: Hansen Ekkehard
Published: April 2005

Plants present a cost effective production system for high value proteins. There is an increasing world demand for cheap vaccines that can be readily administered to the population, especially in economically less developed regions. A promising concept is the production of vaccines in plants that could be grown locally. Expression of antigenic peptides in the palatable parts of plants can lead to the production of edible active vaccines. Two major strategies are: i) to express antigens in transgenic plants, and ii) to produce antigenic peptides on the surface of plant viruses that could be used to infect host plants. This review considers the experimental data and early results for both strategies, and discusses the potential and problems of this new technology
Absence of the E2 allele of apolipoprotein in Amerindians
Authors: Marin Guilherme B. , Tavella Marli H. , Guerreiro João F. , Santos Sidney E.B. , Zago Marco A.
Published: April 2005

Determination of the ApoE allele distribution in five South American Amerindian tribes revealed absence of the ApoE2 allele, accompanied by high ApoE3 and low ApoE4 allele frequencies for most tribes, a distribution only previously reported for the Inuit Eskimo from Greenland.
Histometric study of socket healing after tooth extraction in rats treated with diclofenac
Authors: Yugoshi Luciana Ibara , Sala Miguel Angel , Brentegani Luiz Guilherme , Carvalho Teresa Lúcia Lamano
Published: April 2005

The purpose of the present study was to investigate if diclofenac administration interferes with the time course of alveolar wound healing in rats. Forty-two Wistar rats were used, 21 rats received 10 mg/kg/day of diclofenac one day before and 4 days after extraction of the right maxillary incisors and 21 rats received saline. The animals were sacrificed 7, 14 and 21 days after tooth extraction. Progressive new bone formation and a decrease in the volume fraction of blood clot and connective tissue from 1 to 3 weeks after tooth extraction was quantified using the histometric point-counting method. Diclofenac treatment caused a significant delay in new bone formation in association with an impairment of blood clot remission/organization.
Submucous implant of abrasive dental materials in rat tongues: clinical and histological evaluation
Authors: Pistóia Alexandre Dorneles , Figueiredo Maria Antonia Zancanaro de
Published: April 2005

This study evaluated the clinical and histological manifestations produced by the submucuous implant of abrasive dental materials in the rat tongue. A total of 128 rats were divided into 4 groups of 32 rats each, according to the material selected for the implant: Herjos-F prophylactic paste both in its normal composition as well as lacking its abrasive components, SS White pumice stone and the abrasive powder of the 3M finishing and polishing sandpaper. The specimens were submitted to clinical and histological analyses at 30, 60, 90 and 120 days. After 90 days, the formation of nodular lesions in animals implanted with materials containing abrasive substances was observed. Histologically, these materials produced marked chronic granulomatous reactions. Herjos-F prophylactic paste produced the greatest reaction. However, without the abrasive components, this paste caused the mildest tissue reactions, with no inflammatory response, that was seen in a progressively greater number of cases after 90 days.
Activity of endodontic antibacterial agents against selected anaerobic bacteria
Authors: Ferreira Cláudio Maniglia , Rosa Odila Pereira da Silva , Torres Sérgio Aparecido , Ferreira Flaviana Bombarda de Andrade , Bernardinelli Norberti
Published: April 2005

The antimicrobial activity of substances used as antibacterial agents (solutions of 10% calcium hydroxide, camphorated paramonochlorophenol - PMCC, 2% chlorhexidine digluconate and 10% castor oil plant detergent) on anaerobic bacteria (Fusobacterium nucleatum ATCC 25586, Prevotella nigrescens ATCC 33563, Clostridium perfringens ATCC 13124 and Bacteroides fragilis ATCC 25285), using a broth dilution technique, was evaluated in vitro. For determination of minimum inhibitory and minimum bactericide concentrations (MIC and MBC), two culture broths, Reinforced Clostridial Medium (RCM) and supplemented Brucella, standardized inoculum and serially diluted solutions were used. All antibacterial agents presented antimicrobial activity that varied for different bacteria. There were no differences in the performance of the two broths. Chlorhexidine digluconate was the most effective, with the lowest MICs, followed by castor oil detergent, PMCC and calcium hydroxide. C. perfringens and B. fragilis were the most resistant bacteria to all agents.
Bilateral fusion of mandibular second molars with supernumerary teeth: case report
Authors: Nunes Eduardo , Moraes Ivaldo Gomes de , Novaes Paulo Márcio de Oliveira , Sousa Simone Maria Galvão de
Published: April 2005

Fusion is a developmental anomaly characterized by the union of two adjacent teeth. In this article we report a rare case of bilateral fusion of permanent mandibular second molars with supernumerary teeth. The rarity with which this entity appears, along with its complex characteristics, often make it difficult to treat. The endodontic management of one tooth is described, as well as the successful treatment of a periradicular lesion.
Histomorphometric analysis of rat alveolar wound healing with hydroxyapatite alone or associated to BMPs
Authors: Brandão Alexandre C. , Brentegani Luís Guilherme , Novaes Jr. Arthur B. , Grisi Márcio Fernando M. , Souza Sérgio Luís Scombatti de , Taba Jr. Mario , Salata Luiz Antônio
Published: April 2005

Several materials and techniques have been proposed to improve alveolar wound healing and decrease loss of bone height and thickness that normally follow dental extraction. The objective of this research was the histologic analysis of bone morphogenetic proteins implanted into dental alveoli of rats after extraction. A total of 45 adult male Wistar rats were divided into three groups of 15 animals each: control (no treatment), implanted with pure hydroxyapatite (HA, 3 mg) and implanted with hydroxyapatite plus bone morphogenetic proteins (HA/BMPs, 3 mg). Five animals from each group were sacrificed at 7, 21 and 42 days after extraction for the histometric analyses of the osteoconductive potential of hydroxyapatite associated or not with BMPs. After dissection, fixation, decalcification and serial microtomy of 6-µm thick sections, the samples were stained with hematoxylin-eosin for histologic and histometric analyses. Both HA and HA/BMPs caused a delay in wound healing compared to control animals, evaluated by the percentage of bone tissue in the alveoli. The treatment with HA/BMPs had the greatest delay at 21 days, even though it produced values similar to the control group at 42 days. The materials did not improve alveolar repair in the normal period of wound healing and the association of HA/BMPs did not have osteoconductive properties with granulated hydroxyapatite as the vehicle.
Shear bond strength of enamel surface treated with air-abrasive system
Authors: Borsatto Maria Cristina , Catirse Alma Blásida Elisaur Benitez , Palma Dibb Regina Guenka , Nascimento Telma Nunes do , Rocha Renata Andréa Salvitti de Sá , Corona Silmara Aparecida Milori
Published: April 2005

The aim of this study was to evaluate the shear bond strength of a composite resin to dental enamel, using three different surface treatments. Fifteen sound third molars were randomly assigned to three groups. The mesial and distal surfaces were flattened and covered using adhesive tape with a central orifice delimiting the adhesion area (7.07 mm²). Group I, the enamel surface was conditioned with 37% phosphoric acid for 15 s; group II, the surface was treated using air abrasion with aluminum oxide; group III, the enamel surface was treated using an association of air abrasion with aluminum oxide and 37% phosphoric acid. The Single Bond (3M) adhesive system was applied and a Teflon matrix was placed and filled with composite resin Z-100 (3M) and light-cured. The shear bond strength test was performed with a universal testing machine. The acid etching technique and air abrasion with aluminum oxide associated with acid etching had the highest shear bond strength values. Data were subjected to statistical analysis using ANOVA and the Tukey test, and no statistically significant difference in shear bond strength was observed between group I (12.49 ± 2.85 MPa) and group III (12.59 ± 2.68 MPa). In contrast, both groups had statistically better shear bond strengths compared to group II (0.29 ± 0.56 MPa; p<0.05). Air abrasion with aluminum oxide does not substitute acid etching. The association of these methods to obtain adequate adhesion to the substrate is necessary.
Changes in occlusal vertical dimension in microwave processing of complete dentures
Authors: Barbosa Débora Barros , Compagnoni Marco Antonio , Leles Cláudio Rodrigues
Published: April 2005

This study investigated the effect of different microwave curing cycles on the changes in occlusal vertical dimension of complete dentures. Four test groups with 12 maxillary dentures each were evaluated. Groups 1, 2 and 3 were polymerized with different cycles by microwave radiation and Group 4 was the control and cured by water bath. The average pin opening for all groups was less than 0.5 mm. There was no significant difference between the groups polymerized by the microwave method and the control group. However, analyses of the vertical dimension changes showed statistically significant differences between groups 2 (0.276 ± 0.141 mm) and 3 (0.496 ± 0.220 mm).
Histologic study of use of microfibrillar collagen hemostat in rat dental sockets
Authors: Magro-Érnica Natasha , Magro-Filho Osvaldo , Rangel-Garcia Idelmo
Published: April 2005

The aim of this paper was to evaluate if the placement of microfibrillar collagen hemostat (MCH) into a dental socket interfered with healing. General anesthesia was administered to 30 adult male Albinus Wistar rats and the maxillary right central incisor was extracted. In the control group after each tooth was extracted, the socket was sutured. In the MCH group after each tooth was extracted, MCH was placed into the socket before suturing. Postoperatively, 5 animals were sacrificed from each group at 7, 21 and 28 days. The right maxilla was removed from each animal and histologic slides were stained with Masson's trichromic and hematoxylin and eosin. Quantitative and qualitative analyses were done. The percentage of bone area in the dental socket was quantified using the Image Lab 98 image analysis system. The bone area formation for the control and MCH groups was: 8.1% and 3.3% at 7 days, 34.4% and 33% at 21 days and 41% and 41.3% at 28 days, respectively. We concluded that MCH interferes with the beginning of dental socket healing but does not interfere with the final healing of the dental socket.
Antimicrobial effect of 2% sodium hypochlorite and 2% chlorhexidine tested by different methods
Authors: Estrela Carlos , Ribeiro Rosane Galhardo , Estrela Cyntia R.A. , Pécora Jesus Djalma , Sousa-Neto Manoel Damião
Published: April 2005

The objective of this study was to analyze the antimicrobial effect of 2% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) by agar diffusion test and by direct exposure test. Five microorganisms: Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Bacillus subtilis, Candida albicans, and one mixture of these were used. These strains were inoculated in brain heart infusion (BHI) and incubated at 37ºC for 24 h. For the agar diffusion test (ADT), 18 Petri plates with 20 ml of BHI agar were inoculated with 0.1 ml of the microbial suspensions, using sterile swabs that were spread on the medium, obtaining growth in junction. Fifty-four paper disks (9 mm in diameter) were immersed in the experimental solutions for 1 min. Subsequently, three papers disks containing one of the substances were placed on the BHI agar surface in each agar plate. The plates were maintained for 1 h at room temperature, and then incubated at 37ºC for 48 h. The diameter of microbial inhibition was measured around the papers disks containing the substances. For the direct exposure test, 162 #50 sterile absorbent paper points were immersed in the experimental suspensions for 5 min, and were then placed on Petri plates and covered with one of the irrigant solutions, or with sterile distilled water (control group). After intervals of 5, 10 and 30 min, the paper points were removed from contact with the solutions and individually immersed in 7 ml of Letheen Broth, followed by incubation at 37ºC for 48 h. Microbial growth was evaluated by turbidity of the culture medium. A 0.1 ml inoculum obtained from the Letheen Broth was transferred to 7 ml of BHI, and incubated at 37ºC for 48 h. Bacterial growth was again evaluated by turbidity of the culture medium. Gram stain of BHI cultures was used for verification of contamination and growth was determined by macroscopic and microscopic examination. The best performance of antimicrobial effectiveness of NaOCl was observed in the direct exposure test, and of CHX was observed in the agar diffusion test. The magnitude of antimicrobial effect was influenced by the experimental methods, biological indicators and exposure time.
Orthopedic cervical headgear in Class II treatment: case report
Authors: Enoki Carla , Matsumoto Mírian Aiko Nakane , Ferreira José Tarcísio Lima
Published: April 2005

Early treatment for Class II malocclusion was undertaken with the objective of correcting skeletal disproportion by altering the growth pattern. A case of Class II, Division 1 malocclusion in the mixed dentition was corrected to Class I molar relationship using orthopedic cervical headgear, with nonextraction edgewise therapy. Cephalometric analysis indicated a reduction in the maxillomandibular discrepancy (ANB) correcting the Class II malocclusion to Class I malocclusion. The treatment showed that this was achieved by downward displacement and inhibition of the forward growth of the maxilla and growth of the mandible. There was no downward rotation of the mandible nor maxillary first molar extrusion. There was improvement in the jaw relationship.
Healing process of dog teeth after post space preparation and exposition of the filling material to the oral environment
Authors: Barbosa Henrian Gonzaga , Holland Roberto , Souza Valdir de , Dezan Júnior Eloi , Bernabé Pedro Felício Estrada , Otoboni Filho José Arlindo , Nery Mauro Juvenal
Published: April 2005

The purpose of this study was to observe the influence of coronal leakage on the behavior of periapical tissues after root canal filling and post space preparation. Forty root canals of dogs' teeth were instrumented and filled by the lateral condensation technique with gutta percha points and the cements Sealer 26 and Roth. After post space preparation, the remaining filling material was either protected or not protected with a plug of the temporary cement Lumicon. After root canal exposition to the oral environment for 90 days, the animals were killed and specimens were removed and prepared for histomorphological analysis. The Brown and Brenn technique showed 70% of cases with microorganism leakage for Roth cement, and 20% with Sealer 26. When a plug of Lumicon was employed, there was 30% leakage for Roth cement and 0% for Sealer 26. A chronic inflammatory reaction was more frequently observed with Roth cement than with Sealer 26. It was concluded that a plug of Lumicon was efficient in controlling microorganism coronal leakage (p=0.05), and that Sealer 26 was more biocompatible and sealed root canals better than Roth sealer (p=0.01).
Guided bone regeneration with subperiosteal implants of PTFE and hydroxyapatite physical barriers in rats
Authors: Macedo Nelson Luiz de , Macedo Luís Guilherme Scavone de , Matuda Fábio da Silva , Ouchi Suzana Martins , Monteiro Adriana Socorro Ferreira , Carvalho Yasmin Rodarte
Published: April 2005

Regeneration of periodontal and alveolar ridge defects utilizing membranes is a well-established procedure in reconstructive surgery. Biomaterial characteristics and membrane design employed in guided tissue regeneration (GTR) techniques play an important role in good results. The purpose of this histologic experimental study in rats was to compare the use of two physical barriers in the osteopromotion by using GTR principles in bone defects created in tibias. Fifteen animals divided into 3groups were used: group I (non-porous polytetrafluoroethylene (PTFE) barrier), group II (coral hydroxyapatite (HA) blocks), and group III (defects that received no physical barrier). Histological examination showed varied amounts of newly formed bone beneath both types of barriers. The non-porous PTFE barrier showed better results than the HA group. The results of this study suggest that bone regeneration can be successfully enhanced by a submerged membrane technique.
Evaluation of shear bond strength of composite to porcelain according to surface treatment
Authors: Kussano Claudia Minami , Bonfante Gerson , Batista José Gilmar , Pinto João Henrique Nogueira
Published: April 2005

This study evaluated the shear bond strength of porcelain/composite using 40 metal + porcelain + composite cylindrical specimens divided into 4 groups, according to porcelain surface treatment: 1) no treatment, 2) mechanical retentions performed with diamond burs, 3) etching with phosphoric acid+silane, and 4) etching with hydrofluoric acid+silane. After being stored in distilled water at room temperature for one week, the specimens were submitted to a shear force (load) and the data were analyzed statistically (ANOVA). The means (in Mpa) of the groups were: 4.71 (group 1); 4.81 (group 2); 11.76 (group 3); 11.07 (group 4). There were no statistically significant differences between groups 1 and 2 and between groups 3 and 4.
Image quality in digital radiographic systems
Authors: Almeida Solange Maria de , Oliveira Ana Emília Figueiredo de , Ferreira Rívea Inês , Bóscolo Frab Norberto
Published: April 2005

The aim of the present study was to evaluate the image quality of four direct digital radiographic systems. Radiographs were made of the maxillary central incisor and mandibular left molar regions of a dry skull, and an aluminum step-wedge. The X-ray generator operated at 10 mA, 60 and 70 kVp, and images were acquired with 3, 5, 8, 12, 24 and 48 exposure pulses. Six well-trained observers classified the images by means of scores from 1 to 3. Collected data were submitted to nonparametric statistical analysis using Fisher's exact test. Statistical analysis showed significant differences (p<0.01) in image quality with the four systems. Based on the results, it was possible to conclude that: 1) all of the digital systems presented good performance in producing acceptable images for diagnosis, if the exposures of the step-wedge and the maxillary central incisor region were made at 5 pulses, as well as at 8 pulses for the mandibular left molar region, selecting 60 or 70kVp; 2) higher percentages of acceptable images were obtained with the administration of lower radiation doses in CCD-sensors (charge-coupled device); 3) the Storage Phosphor systems produced acceptable images at a large range of exposure settings, that included low, intermediate and high radiation doses.
Root caries prevalence in a group of Brazilian adult dental patients
Authors: Watanabe Marlívia G.C.
Published: April 2005

The aim of this study was to measure the caries prevalence in the root surface in a group of Brazilian adults. The prevalence and their intraoral distribution of caries lesions of root surface were assessed in dental patients ranging in age from 35 to 44 and from 50 to 59 years of age of both sexes (n=360). A total of 98.9% had root surfaces with gingival recession and 78.1% had at least one root caries lesion. The prevalence of the disease was analyzed using the Root Caries Index (RCI). The average value was greater for women (18.6%) than for men (13.4%) (p<0.01) and similar in both age groups (p>0.01). The maxillary canines and first premolars and the mandibular molars presented the greatest RCI values. The RCI was greater in the proximal surface of the maxilla and buccal surface of the mandible. We conclude that caries of the root surface are present in the Brazilian population and deserve attention concerning their actual role in the epidemiology of principal oral diseases of the adult population.