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1.
Ann Oncol ; 28(4): 791-797, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28039177

RESUMO

Background: Anaplastic lymphoma kinase (ALK) inhibition using crizotinib has become the standard of care in advanced ALK-rearranged non-small cell lung cancer (NSCLC), but the treatment outcomes and duration of response vary widely. Echinoderm microtubule-associated protein-like 4 (EML4)-ALK is the most common translocation, and the fusion variants show different sensitivity to crizotinib in vitro. However, there are only limited data on the specific EML4-ALK variants and clinical responses of patients to various ALK inhibitors. Patients and methods: By multiplex reverse-transcriptase PCR, which detects 12 variants of known EML4-ALK rearrangements, we retrospectively determined ALK fusion variants in 54 advanced ALK rearrangement-positive NSCLCs. We subdivided the patients into two groups (variants 1/2/others and variants 3a/b) by protein stability and evaluated correlations of the variant status with clinical responses to crizotinib, alectinib, or ceritinib. Moreover, we established the EML4-ALK variant-expressing system and analyzed patterns of sensitivity of the variants to ALK inhibitors. Results: Of the 54 tumors analyzed, EML4-ALK variants 3a/b (44.4%) was the most common type, followed by variants 1 (33.3%) and 2 (11.1%). The 2-year progression-free survival (PFS) rate was 76.0% [95% confidence interval (CI) 56.8-100] in group EML4-ALK variants 1/2/others versus 26.4% (95% CI 10.5-66.6) in group variants 3a/b (P = 0.034) among crizotinib-treated patients. Meanwhile, the 2-year PFS rate was 69.0% (95% CI 49.9-95.4) in group variants 1/2/others versus 32.7% (95% CI 15.6-68.4) in group variants 3a/b (P = 0.108) among all crizotinib-, alectinib-, and ceritinib-treated patients. Variant 3a- or 5a-harboring cells were resistant to ALK inhibitors with >10-fold higher half maximal inhibitory concentration in vitro. Conclusion: Our findings show that group EML4-ALK variants 3a/b may be a major source of ALK inhibitor resistance in the clinic. The variant-specific genotype of the EML4-ALK fusion allows for more precise stratification of patients with advanced NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Pulmonares/genética , Proteínas de Fusão Oncogênica/genética , Adulto , Idoso , Antineoplásicos/uso terapêutico , Carbazóis/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Crizotinibe , Intervalo Livre de Doença , Feminino , Genótipo , Humanos , Hibridização in Situ Fluorescente , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Piperidinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Estabilidade Proteica , Pirazóis/uso terapêutico , Piridinas/uso terapêutico , Pirimidinas/uso terapêutico , Estudos Retrospectivos , Sulfonas/uso terapêutico
2.
Cell Calcium ; 39(3): 275-92, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16406008

RESUMO

Voltage-dependent calcium channels (VDCCs) in sensory neurones are tonically up-regulated via Ras/extracellular signal regulated kinase (ERK) signalling. The presence of putative ERK consensus sites within the intracellular loop linking domains I and II of neuronal N-type (Ca(v)2.2) calcium channels and all four neuronal calcium channel beta subunits (Ca(v)beta), suggests that Ca(v)2.2 and/or Ca(v)betas may be ERK-phosphorylated. Here we report that GST-Ca(v)2.2 I-II loop, and to a lesser extent Ca(v)beta1b-His(6), are substrates for ERK1/2 phosphorylation. Serine to alanine mutation of Ser-409 and/or Ser-447 on GST-Ca(v)2.2 I-II loop significantly reduced phosphorylation. Loss of Ser-447 reduced phosphorylation to a greater extent than mutation of Ser-409. Patch-clamp recordings from wild-type Ca(v)2.2,beta1b,alpha2delta1 versus mutant Ca(v)2.2(S447A) or Ca(v)2.2(S409A) channels revealed that mutation of either site significantly reduced current inhibition by UO126, a MEK (ERK kinase)-specific inhibitor that down-regulates ERK activity. However, no additive effect was observed by mutating both residues together, suggesting some functional redundancy between these sites. Mutation of both Ser-161 and Ser-348 on Ca(v)beta1b did not significantly reduce phosphorylation but did reduce UO126-induced current inhibition. Crucially, co-expression of Ca(v)2.2(S447A) with Ca(v)beta1b(S161,348A) had an additive effect, abolishing the action of UO126 on channel current, an effect not seen when Ca(v)beta1b(S161,348A) was co-expressed with Ca(v)2.2(S409A). Thus, Ser-447 on Ca(v)2.2 and Ser-161 and Ser-348 of Ca(v)beta1b appear to be both necessary and sufficient for ERK-dependent modulation of these channels. Together, our data strongly suggest that modulation of neuronal N-type VDCCs by ERK involves phosphorylation of Ca(v)2.2alpha1 and to a lesser extent possibly also Ca(v)beta subunits.


Assuntos
Canais de Cálcio Tipo N/fisiologia , MAP Quinases Reguladas por Sinal Extracelular/fisiologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Butadienos/farmacologia , Células COS , Canais de Cálcio Tipo L/fisiologia , Canais de Cálcio Tipo N/genética , Chlorocebus aethiops , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Nitrilas/farmacologia , Fosforilação , Mutação Puntual , Ratos , Serina/metabolismo , Transdução de Sinais/fisiologia
3.
Am J Trop Med Hyg ; 59(6): 859, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9886188

RESUMO

We conducted a retrospective analysis of hematologic changes in 89 patients with imported Plasmodium falciparum malaria. Thirteen (15%) were anemic at presentation, 60 (67%) had thrombocytopenia, and 63% had lymphopenia. There was a significant inverse relationship between parasitemia and platelet count. Anemia is rare among patients with imported malaria, while thrombocytopenia and lymphopenia are common.


Assuntos
Doenças Hematológicas/etiologia , Malária Falciparum/sangue , Doença Aguda , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Estudos Retrospectivos
4.
Theriogenology ; 33(2): 509-18, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16726747

RESUMO

This study examined the effects of two specific neurotransmitter receptor antagonists, naloxone (NAL; mu-opioid) and yohimbine (YOH; alpha(2)-adrenergic), on pulsatile luteinizing hormone (LH) release during the luteal phase (Day 10; Day 0 = estrus) of beef cows. Treatments were saline i.m. (C; n = 4); 1mg/kg NAL i.m. followed 3 h later by two 0.5 mg/kg injections spaced 2.5 h apart (N; n = 4); 0.2 mg/kg YOH i.v. (Y; n = 3); or combined N and Y regimens, with Y preceding N by 30 min (NY; n = 4). Blood samples were collected for 8 h before (Period I) and after (Period II) initiation of treatment. Respiration rates of Y cows were similar to C cows during Period II. However, respiration rates of N and NY animals increased 70% within 30 min of the first NAL injection. Acute LH release was not observed in response to either NAL or YOH. Pulsatile LH secretion was unchanged in N, Y and NY cows during Period II when compared with Period I. In contrast, basal and pulsatile LH secretion was inhibited in C cows during Period II. The inhibition of LH secretion in C animals following NAL indicate that the cows were under stress during Period II. Thus, these data suggest that the inhibition of LH release in stressed animals can be overcome by pharmacologic attenuation of inhibitory (N) or accentuation of stimulatory (Y) signals to LHRH-containing neurons.

5.
Theriogenology ; 29(4): 951-60, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16726416

RESUMO

Estrous response, pregnancy rate, and the relationship between palpable corpora lutea (CL) and plasma progesterone concentrations were studied during the spring (n = 149) and fall (n = 146) breeding seasons using postpartum, crossbred beef cows consisting of 0-Brahman, 1 4 - Brahman , or 1 2 Brahman breeding. At the start of each breeding season, a jugular blood sample was collected for progesterone analysis; each cow was palpated for the presence of a CL and randomly alloted within breed to a non-treated control or Synchro-Mate-B (SMB) treatment. Fewer (P<0.01) fall than spring bred cows exhibited estrus within the first 21 d of breeding. Within 48 h of implant removal, 84 and 64% (spring and fall, respectively) of synchronized cows exhibited estrus. In both seasons, more SMB than control cows became pregnant by 7 d of breeding. Percentage of Brahman breeding did not influence estrous response or pregnancy rate. On the basis of 292 evaluations, palpation per rectum correctly assessed ovarian status 74% of the time. These data indicate that although season can influence response. SMB can be used effectively to synchronize Brahman crossbred cows. In addition, it was found that there is a close relationship between palpation per rectum and plasma concentrations of progesterone.

6.
J Anim Sci ; 67(9): 2354-62, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2689418

RESUMO

Twenty-two nonlactating Hereford cows exhibiting normal estrous cycles were fed either maintenance (M) or restricted (R) diets until most of the R cows became anestrus; R cows then were fed 160% of the M diet until estrous cycles resumed. Concentrations of progesterone, glucose, insulin and nonesterified fatty acids (NEFA) were determined in weekly blood samples. Blood also was collected frequently, before and after i.v. infusion of 300 ml of a 40% glucose solution, to evaluate responses in blood concentrations of glucose and insulin when cows were exhibiting normal estrous cycles, when R cows were initiating anestrus, during anestrus, and at the reinitiation of estrous cycles. Losses in BW and body condition score in R cows were associated with reduced (P less than .01) concentrations of glucose and insulin and greater (P less than .01) concentrations of NEFA in blood plasma compared with those of M cows. During normal estrous cycles, disappearance of infused glucose from plasma and concentrations of insulin in serum were similar for R and M cows. Glucose disappearance from plasma was retarded and serum concentrations of insulin remained increased for a longer time after glucose infusion in R at the start of anestrus compared with M cows (P less than .01). Similarly, during anestrus, the rate of glucose disappearance was slower for R cows (P less than .01). During refeeding of R cows, disappearance of infused glucose was similar for R and M cows. In conclusion, reduced concentrations of glucose and insulin and increased concentrations of NEFA in blood were associated with nutritional anestrus and the glucoregulatory effects of insulin were compromised during nutritional anestrus.


Assuntos
Anestro/sangue , Glicemia/análise , Bovinos/fisiologia , Estro/sangue , Ácidos Graxos não Esterificados/sangue , Insulina/sangue , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Bovinos/sangue , Dieta , Feminino , Análise dos Mínimos Quadrados , Progesterona/sangue , Análise de Regressão
7.
J Anim Sci ; 67(6): 1520-6, 1989 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2768109

RESUMO

Multiparous Hereford cows (n = 22) with moderate to good body condition scores (BCS) were randomly allotted to maintenance (M) or restricted (R) diets under drylot conditions. Cows on M diets received adequate feed to maintain initial BW, whereas R cows were fed to lose 1% of their initial BW weekly until luteal activity ceased. When most of the R cows became anestrous, their diet was increased to allow BW gain and resumption of ovarian cyclicity. Body weights and BCS were recorded weekly and luteal activity was assessed by weekly determination of progesterone in plasma. Concentrations of LH in serum were quantified in weekly samples and in samples obtained frequently at four selected times. Restricted cows had reduced BW (P less than .01) by 5 wk and reduced BCS (P less than .01) by 15 wk compared with M cows. Luteal activity ceased after 26 +/- 1 wk of reduced nutrient intake in 91% of the R cows; R cows had lost 24.0 +/- .9% of their initial BW and had a BCS of 3.5 +/- .3. Lack of luteal activity was associated with absence of behavioral estrus. Estrous cycles resumed 9 +/- 2 wk after the diet of R cows was increased, at which time R cows weighed 12 +/- 3% less than at the start of the experiment and had a BCS of 4.6 +/- .2. Concentrations of LH in serum samples obtained weekly were reduced (P less than .01) in R cows compared with M cows. In addition, LH pulse frequency was reduced (P less than .05) when R cows were initiating anestrus.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Anestro/fisiologia , Bovinos/fisiologia , Corpo Lúteo/fisiologia , Estro/fisiologia , Hormônio Luteinizante/sangue , Anestro/sangue , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Feminino , Progesterona/sangue , Distribuição Aleatória , Fatores de Tempo , Aumento de Peso
8.
Gen Dent ; 48(3): 272-6, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11199592

RESUMO

This study compared a simple and readily available shade guide color-matching test with the general industry standard test for color discrimination. This study indicates that a simple screening test for color defective vision and color discrimination skills in dentistry can be performed by matching two Vita-Lumin shade guides. Those dental office personnel who score a low number of matches in the Vita test (that is, seven or fewer correct matches) should have additional color discrimination testing and refer shade matching to other personnel with higher scores.


Assuntos
Testes de Percepção de Cores , Porcelana Dentária , Pigmentação em Prótese , Adulto , Cor/normas , Recursos Humanos em Odontologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
9.
Proc Natl Acad Sci U S A ; 102(32): 11230-5, 2005 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-16061813

RESUMO

All auxiliary alpha2delta subunits of voltage-gated Ca2+ (Ca(V)) channels contain an extracellular Von Willebrand factor-A (VWA) domain that, in alpha2delta-1 and -2, has a perfect metal-ion-dependent adhesion site (MIDAS). Modeling of the alpha2delta-2 VWA domain shows it to be highly likely to bind a divalent cation. Mutating the three key MIDAS residues responsible for divalent cation binding resulted in a MIDAS mutant alpha2delta-2 subunit that was still processed and trafficked normally when it was expressed alone. However, unlike WT alpha2delta-2, the MIDAS mutant alpha2delta-2 subunit did not enhance and, in some cases, further diminished Ca(V)1.2, -2.1, and -2.2 currents coexpressed with beta1b by using either Ba2+ or Na+ as a permeant ion. Furthermore, expression of the MIDAS mutant alpha2delta-2 reduced surface expression and strongly increased the perinuclear retention of Ca(V)alpha1 subunits at the earliest time at which expression was observed in both Cos-7 and NG108-15 cells. Despite the presence of endogenous alpha2delta subunits, heterologous expression of alpha2delta-2 in differentiated NG108-15 cells further enhanced the endogenous high-threshold Ca2+ currents, whereas this enhancement was prevented by the MIDAS mutations. Our results indicate that alpha2delta subunits normally interact with the Ca(V)alpha1 subunit early in their maturation, before the appearance of functional plasma membrane channels, and an intact MIDAS motif in the alpha2delta subunit is required to promote trafficking of the alpha1 subunit to the plasma membrane by an integrin-like switch. This finding provides evidence for a primary role of a VWA domain in intracellular trafficking of a multimeric complex, in contrast to the more usual roles in binding extracellular ligands in other exofacial VWA domains.


Assuntos
Canais de Cálcio/metabolismo , Modelos Moleculares , Fator de von Willebrand/metabolismo , Sítios de Ligação , Canais de Cálcio/química , Canais de Cálcio/genética , Cátions Bivalentes/metabolismo , DNA Complementar/genética , Eletrofisiologia , Immunoblotting , Imuno-Histoquímica , Imunoprecipitação , Metais/metabolismo , Microscopia Confocal , Mutação/genética , Conformação Proteica
10.
J Prosthet Dent ; 70(3): 239-44, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8410731

RESUMO

The indications and features of the new Denar Combi articulator are reviewed. The Combi articulator was designed primarily as a set path instrument, but can also be used as a semiadjustable or fully adjustable stereographic articular. The articulator can be programmed for any of these modes, but the Combi model is limited when used as a stereographic instrument according to the manufacturer's instructions, with the instrument-precipitated geometric errors. These errors were identified mathematically, and an accurate technique for the instrument is described.


Assuntos
Articuladores Dentários , Registro da Relação Maxilomandibular/instrumentação , Humanos , Reprodutibilidade dos Testes , Dimensão Vertical
11.
J Prosthet Dent ; 69(3): 340-3, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8445569

RESUMO

The microwave processing procedure has been shown to be an efficient and accurate method of polymerizing poly(methyl methacrylate) resin for the fabrication of dentures. This article describes procedures to expand the uses of the microwave technique. With standard laboratory procedures, the microwave technique can improve and simplify denture relines, repairs, and rebasing of partial dentures.


Assuntos
Reembasamento de Dentadura/métodos , Reparação em Dentadura/métodos , Metilmetacrilatos/efeitos da radiação , Micro-Ondas , Prótese Parcial Removível , Humanos
12.
J Prosthet Dent ; 80(5): 559-64, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9813806

RESUMO

STATEMENT OF PROBLEM: When 2 implants are used to support a removable overdenture, optimal stress distribution to minimize forces to the implants is desired. PURPOSE: This study used photoelastic analysis to compare the stress patterns generated around implants with 2 retention mechanisms. MATERIAL AND METHODS: Two root form implants were anchored in a photoelastic mandible and a removable overdenture was fabricated. The denture was lined with a resilient layer of impression material to simulate oral mucosa. Attachment of the denture to the implants was varied by using ball/O-ring and bar-clip attachments. Vertical and oblique occlusal forces from 10 to 200 lb were applied unilaterally to the right and left first molars. Resultant stress distributions in the photoelastic mandible were photographed and evaluated. RESULTS: With vertical forces, the ball/O-ring attachment transferred minimal stress to both implants. Vertical forces applied to the bar-clip overdenture created immediate stress patterns of greater magnitude and concentration on both implants. A posterior oblique load resulted in similar stress patterns to both systems with slightly greater stress to the bar-clip overdenture. CONCLUSIONS: Within the limits of this study, ball/O-ring attachments transferred less stress to implants than the bar-clip attachments when the photoelastic model was subjected to a posterior vertical load.


Assuntos
Implantes Dentários , Análise do Estresse Dentário , Retenção de Dentadura , Revestimento de Dentadura , Prótese Parcial Removível , Força de Mordida , Dente Suporte , Implantação Dentária Endóssea/métodos , Análise do Estresse Dentário/métodos , Retenção de Dentadura/instrumentação , Elasticidade , Humanos , Luz , Mandíbula , Modelos Dentários
13.
Anat Histol Embryol ; 20(4): 363-8, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1796788

RESUMO

Postnatal development and variation of the bony cranial border of the lateral vertebral foramen (LVF) of the atlas was studied in 96 dogs. Developmental ossification was investigated in 8 known-aged Miniature Schnauzer pups, after each atlas was prepared either as an alizarin-red stained clearing or as a dried cleaned bone. Variation was investigated in 63 atlases from mature dogs and by study of radiographs from 25 mature dogs of various breeds. The soft tissue structures passing through the LVF and attaching to its cranial border were dissected in an additional 2 embalmed and 2 fresh cadavers. In 2-week-old pups, the LVF was represented by a notch in the cranial margin of the bony arch of the atlas, with a cartilage bar completing the foramen cranially. Between 6 and 16 weeks the bar forming the cranial bony border of the LVF ossified in its preexisting cartilage anlage. In mature dogs, the LVF was present in the craniolateral aspect of the arch of the atlas and was recognized on lateral radiographs. The vertebral artery and vein, and first cervical nerve passed through the LVF and the atlantooccipital joint capsule and dorsal membrane attached to the cranial border of the LVF. In one dog the cranial border of the LVF of the atlas was incompletely ossified bilaterally. This developmental variant was compared with variations in man and other mammals, and with proatlas neural arch derivatives.


Assuntos
Atlas Cervical/crescimento & desenvolvimento , Cães/crescimento & desenvolvimento , Animais , Atlas Cervical/diagnóstico por imagem , Feminino , Masculino , Radiografia
14.
J Prosthet Dent ; 74(1): 18-24, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7674185

RESUMO

Methods to facilitate the seating of artificial crowns can improve the gingival margins and ensure longevity. This study examined the effects of venting and different luting agents on the seating accuracy and compressive strength of Dicor ceramic crowns. Vented and unaltered anterior restorations were tested using zinc phosphate cement (ZnPO4), glass ionomer, and composite resin cement. Rexillium metal dies of a tooth preparation of a maxillary canine were provided and standardized crowns were fabricated. The artificial crowns were evaluated for adaptation of the finish line before and after cementation, then were compressively loaded to failure. Under the conditions of this study, neither the design of the artificial crown nor the luting agent had a significant effect on the compressive strength. Composite resinous cement appeared to enhance seating of the crown, whereas ZnPO4 cement inhibited seating.


Assuntos
Cimentação , Cerâmica/química , Coroas , Cimentos Dentários/química , Planejamento de Prótese Dentária , Ligas de Cromo/química , Resinas Compostas/química , Dente Canino , Adaptação Marginal Dentária , Porcelana Dentária/química , Cimentos de Ionômeros de Vidro/química , Humanos , Teste de Materiais , Falha de Prótese , Estresse Mecânico , Propriedades de Superfície , Cimento de Fosfato de Zinco/química
15.
Int J Prosthodont ; 6(6): 553-7, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8148026

RESUMO

This study investigated the early erosion of glass ionomer-cement that had been used to lute complete cast crowns. Restorations had margins ending on either enamel or cementum and had various sizes of marginal openings. These restorations were compared to those using a standard zinc phosphate cement. Results showed that leaving the band of excess cement, expressed during the seating of the crown, undisturbed for 10 minutes prevented significant erosion in a wet field. A resin coat was not necessary to provide further protection after removal of the band. Zinc phosphate cement also showed significant early erosion when exposed to moisture.


Assuntos
Coroas , Colagem Dentária/métodos , Cimentos de Ionômeros de Vidro , Cimentação/métodos , Distribuição de Qui-Quadrado , Infiltração Dentária/prevenção & controle , Humanos , Teste de Materiais , Propriedades de Superfície , Cimento de Fosfato de Zinco
16.
Biol Reprod ; 44(6): 961-6, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1873396

RESUMO

The objectives of this experiment were to determine if a postcastration increase in concentrations of LH occurs in nutritionally anestrous beef cows and to examine the relationship between body energy reserves and secretion of LH and insulin-like growth factor-I (IGF-I). Nonpregnant, nonlactating, Hereford cows were fed to maintain (M) body weight (BW), body condition score (BCS), and normal estrous cycles (n = 5) or were fed a restricted (R) diet for 26 wk to lose BW and BCS and to become anestrus (n = 10). At 5-7 wk after the initiation of anestrus, R cows were randomly allotted to be ovariectomized (OVX) via flank incision (n = 5) or to remain intact (INT, n = 5). OVX was performed when R cows became anestrous. All M cows were OVX. Serum was collected frequently the day before and during the first 10 days after OVX, and concentrations of progesterone, estradiol, LH and IGF-I were quantified. On Day 10 after OVX, 1 mg of estradiol was injected into 3 cows from each group and serum was collected for 30 h. After OVX, there was a treatment-by-day effect for mean serum LH and IGF-I concentrations. Concentrations of LH increased (p less than 0.01) and concentrations of IGF-I decreased (p less than 0.05) in M-OVX cows when compared with R-OVX and R-INT cows. Concentrations of LH and IGF-I were similar for R-OVX and R-INT cows. The number of LH pulses was similar for M and R cows.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Anestro/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Hormônio Luteinizante/sangue , Fenômenos Fisiológicos da Nutrição Animal , Animais , Peso Corporal , Bovinos , Metabolismo Energético , Estradiol/farmacologia , Estradiol/fisiologia , Feminino , Hormônio Luteinizante/metabolismo , Ovariectomia , Ovário/fisiologia
17.
Int J Prosthodont ; 6(4): 371-6, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8240648

RESUMO

A computer program that uses cephalometric analyses for determining the patient's occlusal vertical dimension has recently been introduced. Data generated from this computer implies changes in incisal-pin position for articulated casts. This study evaluated the accuracy of this vertical-dimension program using 24 completely dentate, white male subjects with clinically acceptable occlusal vertical dimensions. A cephalometric radiograph was made, and measurements from the tracing were entered into the computer for analysis. Recommended incisal-pin changes ranged from -11 to +25.3 mm, with a mean change of 8.4 mm for all methods tested. These results showed a low correlation with each subject's clinically determined occlusal vertical dimension.


Assuntos
Cefalometria/métodos , Diagnóstico por Computador/métodos , Dimensão Vertical , Adulto , Articuladores Dentários , Oclusão Dentária Central , Humanos , Masculino
18.
J Prosthet Dent ; 80(6): 642-8, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9830067

RESUMO

STATEMENT OF PROBLEM: Visual color matching to determine shades in dentistry is inconsistent and unreliable. If accurate, instrumental measurement of tooth color would provide objective, quantified data to match natural teeth to clinical shade guides. PURPOSE: This study evaluated and compared the ability of a new computerized colorimeter and a simple visual test to match ceramic shade guide teeth. MATERIAL AND METHODS: Thirty-one (n = 31) observers with normal color vision were allowed unlimited time to match one set of Vita Lumin shade guide teeth to the corresponding shade guide teeth of a second Vita Lumin shade guide. The same test was administered to 14 of the observers several months later to determine within-subject variability. A computerized colorimeter (Colortron II) equipped with a positioning guide was used to measure the middle third of each shade guide tooth. Through a "match tool" present in the computer's software, readings from one shade guide were matched with readings of the other shade guide by using CIELAB measurements and DeltaE values. The mean number of correct matches by the colorimeter and of correct matches in visual test were compared with a 1-tailed t test. Repeatability for both tests was determined with a paired t test. RESULTS: The Colortron II instrument correctly matched 8 of the 16 tabs (50% correct), whereas visual matching by examiners averaged 7. 7 of 16 correct matches (48% correct) (standard deviation 2.7). No statistically significant differences existed between the 2 methods. The colorimeter demonstrated 100% repeatability and the visual test demonstrated fair repeatability (correlation coefficient r =.60). CONCLUSIONS: Shade determination by visual means was inconsistent. Accuracy of a new colorimeter in matching porcelain shade guide teeth was only slightly better.


Assuntos
Planejamento de Prótese Dentária/métodos , Pigmentação em Prótese/métodos , Cerâmica , Cor , Colorimetria/instrumentação , Desenho Assistido por Computador/instrumentação , Planejamento de Prótese Dentária/instrumentação , Planejamento de Prótese Dentária/estatística & dados numéricos , Estudos de Avaliação como Assunto , Humanos , Variações Dependentes do Observador , Pigmentação em Prótese/instrumentação , Pigmentação em Prótese/estatística & dados numéricos
19.
J Prosthodont ; 7(4): 250-5, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10196845

RESUMO

PURPOSE: Using the one-step polyvinyl siloxane impression technique, this study compared the effect of putty material working time on the dimensional accuracy of recovered improved stone casts. MATERIALS AND METHODS: An acrylic resin master cast was fabricated with embedded reference points to enable both horizontal and vertical measurements. Four commercially available polyvinyl siloxane impression putties with light body washes were evaluated: 1) Extrude (Kerr), 2) Cutter (Coltere), 3) Express (3M), and 4) Reprosil (Caulk). Each putty was mixed by hand for 30 seconds, placed in a plastic stock tray, and seated on the master cast at 0, 30, 60, 90, and 120 seconds after mixing (N = 100, n = 5). The impressions were poured in improved stone, and vertical and horizontal measurements were made to 0.001 mm between reference points on recovered casts using an optical traveling microscope. ANOVA (p < or = .05) was used to compare vertical and horizontal measurements to master cast dimensions. RESULTS: No statistically significant difference was found among casts for all materials and time periods tested. When horizontal measurement ranges were evaluated, Extrude casts exhibited the widest range of measurement, especially when the trays were seated at 90 and 120 seconds. When vertical measurement ranges were evaluated, Express casts at 120 seconds exhibited the widest range. CONCLUSIONS: A high range of variability in vertical and horizontal dimensions occurred at the later time periods, especially for Extrude and Express casts. As a result of rapid polymerization and poor flow properties of putty materials, the impression tray should be seated within 60 seconds after putty mixing to reduce dimensional variability of recovered casts.


Assuntos
Materiais para Moldagem Odontológica , Técnica de Moldagem Odontológica , Modelos Dentários , Polivinil , Siloxanas , Análise de Variância , Estudos de Avaliação como Assunto , Humanos , Reprodutibilidade dos Testes , Fatores de Tempo
20.
Int J Prosthodont ; 7(3): 280-4, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7916895

RESUMO

Aluminum is one type of metal base material used as an alternative to acrylic resin. This study evaluated whether commonly used denture cleansers cause leaching of the metal base into the cleaning solution. Seven cleansers (Efferdent, Polident, Clorox, Clorox/Cascade, vinegar, Tartar and Stain Remover, and Ivory soap) and two controls (tap water and distilled water) were evaluated. One hundred thirty-five wax samples (30 x 30 x 1 mm) were cast in 99.4% pure aluminum. The 135 samples were randomly assigned to the nine cleanser groups. Each sample was soaked in a cleanser for 0.5, 1, or 8 hours, and the amount of aluminum present in each cleanser was then analyzed by atomic flame-emission spectrometry. The results indicated that all cleansers leached aluminum into solution in varying amounts. Tartar and Stain Remover and Clorox caused the greatest leaching, whereas Ivory soap and Efferdent leached the least.


Assuntos
Alumínio/química , Bases de Dentadura , Higienizadores de Dentadura/química , Análise de Variância , Corrosão , Solubilidade
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