Correlation Between Laser Fluorescence Readings and Volume of Tooth Preparation in Incipient Occlusal Caries In Vitro

This study evaluated the correlation between laser fluorescence readings and the extent of carious tooth structure as measured by the volume of tooth preparation in vitro. One hundred and three permanent molars and premolars containing incipient occlusal caries were selected. DIAGNOdent and QLF readings were obtained according to manufacturer instructions. Caries was removed with ¼ round burs in high speed. The amount of uncured composite needed to fill the prepared cavity was used to calculate the volume of tooth preparation. The Pearson correlation for preparation volume and maximum DIAGNOdent reading and QLF measurements was 0.285 and 0.399 respectively. Sensitivity and specificity of DIAGNOdent was .83 and .60 and .66 and .73 for the cut-off values of 20 and 30 respectively. Within the limitations of this study, it is possible to conclude that laser fluorescence measured with DIAGNOdent and QLF does not appear to correlate well with tooth preparation volume

Correlation between Laser Fluorescence Readings and Volume of Tooth Preparation in Incipient Occlusal Caries In Vitro

This study evaluated the correlation between laser fluorescence readings and the extent of incipient occlusal caries as measured by the volume of tooth preparation in vitro.One hundred and three permanent molars and premolars containing incipient occlusal pit-and-fissure caries and sound occlusal surfaces (1/4 of the sample, control) were selected. DIAGNOdent (KaVo Dental Corporation, Lake Zurich, IL, USA) readings were obtained according to manufacturer instructions. Caries was removed with 1/4 round burs in high speed. The volume of tooth preparation was measured using a surrogate measure based on the amount of composite needed to fill the preparations. Sensitivity and specificity using different cutoff values were calculated for lesions/preparations extending into dentin. The results were analyzed statistically.The Pearson correlation for preparation volume and DIAGNOdent reading measurements was low ( r  = 0.285). Sensitivity and specificity of DIAGNOdent for detection of dentinal lesions were 0.83 and 0.60, and 0.66 and 0.73 for the cutoff values of 20 and 30, respectively.Within the limitations of this study, laser fluorescence measured with DIAGNOdent does not correlate well with extent of carious tooth structure in incipient occlusal caries.Clinicians should not rely only on DIAGNOdent readings to determine the extension of incipient occlusal caries.( J Esthet Restor Dent 22:31–41, 2010)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78687/1/j.1708-8240.2009.00309.x.pd

Triagem primária de doadores de sangue por teste de ácidos nucléicos: desenvolvimento de um método não-comercial e resultados

An "in-house" RT-PCR method was developed that allows the simultaneous detection of the RNA of the Hepatitis C Virus (HCV) and an artificial RNA employed as an external control. Samples were analyzed in pools of 6-12 donations, each donation included in two pools, one horizontal and one vertical, permitting the immediate identification of a reactive donation, obviating the need for pool dismembering. The whole process took 6-8 hours per day and results were issued in parallel to serology. The method was shown to detect all six HCV genotypes and a sensitivity of 500 IU/mL was achieved (95% hit rate). Until July 2005, 139,678 donations were tested and 315 (0.23%) were found reactive for HCV-RNA. Except for five false-positives, all 310 presented the corresponding antibody as well, so the yield of NAT-only donations was zero, presenting a specificity of 99.83%. Detection of a window period donation, in the population studied, will probably demand testing of a larger number of donations. International experience is showing a rate of 1:200,000 - 1:500,000 of isolated HCV-RNA reactive donations.Desenvolveu-se uma metodologia própria ("in-house") baseada em RT-PCR, que permite detectar simultaneamente o RNA do vírus HCV e de um RNA artificial empregado como controle externo. As amostras são analisadas em pools de 6-12 doações, cada doação sendo incluída em dois pools diferentes, um horizontal e um vertical, permitindo a identificação imediata de uma doação reativa, sem a necessidade de desmembrar-se um pool reativo. O processo todo consumiu de 6-8 horas diárias e os resultados foram emitidos em paralelo à sorologia. O método detectou os seis genótipos de HCV, com um limite de sensibilidade de 500 UI/mL (95% hit rate). Até julho de 2005 haviam sido testadas 139.678 doações com a detecção de 315 (0,23%) doações reativas para HCV-RNA. Exceto cinco falso-positivas, todas estas doações também apresentavam o respectivo anticorpo, portanto não se detectou nenhuma doação em janela imunológica. A especificidade foi de 99,83%. A detecção de amostra em janela imunológica, nesta população de doadores, provavelmente demandará a análise de um número maior de doações, espelhando-se na experiência internacional que tem mostrado a detecção de amostras HCV-RNA isoladas em 1:200.000 - 1:500.000 doações

Substituição do teste de p24 Ag (HIV) por um RT-PCR multiplex na triagem primária de doadores de sangue

O uso de testes de ácidos nucleicos (NAT) na rotina de triagem de doadores de sangue tornou-se uma realidade ao final da década de 1990. Descreve-se aqui uma metodologia de RT-PCR multiplex "in-house" que permite a detecção simultânea dos RNAs dos vírus HIV e HCV além de uma molécula artificial de RNA usada como controle externo. O método detecta todos os subtipos de HIV do grupo M e também do grupo N e O, com uma sensibilidade de 500 UI/mL. Após validação, este teste substituiu o do antígeno p24, até então na rotina de triagem em nosso laboratório, desde 1996. De julho de 2001 a fevereiro de 2006 foram testadas 102.469 doações e 41 (0.04%) foram NAT reativas. Uma doação NAT isoladamente reativa (anticorpo não-reativa) foi detectada com soroconversão subseqüente do doador, portanto, o rendimento do NAT nesta população até o presente momento é de 1:102.469. Este número contrasta com a experiência obtida internacionalmente, onde taxas de 1:600.000 - 1:3.100.000 foram descritas.Nucleic Acid Testing (NAT) as a tool for primary screening of blood donors became a reality in the end of the 1990 decade. We report here the development of an "in-house" RT-PCR method that allows the simultaneous (multiplex) detection of HCV and HIV-RNA in addition to an artificial RNA employed as an external control. This method detects all HIV group M subtypes, plus group N and O, with a detection threshold of 500 IU/mL. After validation, the method replaced p24 Ag testing, in use for blood donation screening since 1996 at our services. From July 2001 to February 2006, 102,469 donations were tested and 41 (0.04%) were found HIV-RNA reactive. One NAT-only reactive donation (antibody non-reactive) was observed, with subsequent seroconversion of the implied donor, giving a yield of 1:102,469. This rate is in contrast to the international experience that reports a detection of approximately 1:600,000 - 1:3,100,000 of isolated HIV-RNA donations

Parathyroid Hormone Mediates Hematopoietic Cell Expansion through Interleukin-6

Parathyroid hormone (PTH) stimulates hematopoietic cells through mechanisms of action that remain elusive. Interleukin-6 (IL-6) is upregulated by PTH and stimulates hematopoiesis. The purpose of this investigation was to identify actions of PTH and IL-6 in hematopoietic cell expansion. Bone marrow cultures from C57B6 mice were treated with fms-like tyrosine kinase-3 ligand (Flt-3L), PTH, Flt-3L plus PTH, or vehicle control. Flt-3L alone increased adherent and non-adherent cells. PTH did not directly impact hematopoietic or osteoclastic cells but acted in concert with Flt-3L to further increase cell numbers. Flt-3L alone stimulated proliferation, while PTH combined with Flt-3L decreased apoptosis. Flt-3L increased blasts early in culture, and later increased CD45+ and CD11b+ cells. In parallel experiments, IL-6 acted additively with Flt-3L to increase cell numbers and IL-6-deficient bone marrow cultures (compared to wildtype controls) but failed to amplify in response to Flt-3L and PTH, suggesting that IL-6 mediated the PTH effect. In vivo, PTH increased Lin- Sca-1+c-Kit+ (LSK) hematopoietic progenitor cells after PTH treatment in wildtype mice, but failed to increase LSKs in IL-6-deficient mice. In conclusion, PTH acts with Flt-3L to maintain hematopoietic cells by limiting apoptosis. IL-6 is a critical mediator of bone marrow cell expansion and is responsible for PTH actions in hematopoietic cell expansion

The effect of tooth age on the fracture toughness of four dental bonding systems

Objective: The purpose of this in vitro study was to evaluate the effect of dentin age on the fracture toughness (Kic) of dental bonding systems using the notchless triangular prism (NTP) specimen Kic test. Methods: 80 human molars and pre-molars, 40 of them from patients not older than 45 years ("young") and 40 from patients not younger than 65 years ("old"), were wet ground on 600-grit silicon carbide abrasive paper to obtain a 4x4x4x4mm triangular prisms with the labial surface exposed for bonding. Within each of the two groups, the specimens were randomly assigned to four subgroups (n=10) according to the bonding system to be used for composite bonding: Adper Prompt L-pop (3M ESPE), Clearfil SE (Kuraray), Prime & Bond NT (Dentsply) and Scotch Bond MP (3M ESPE). The composite, Z-100 (3M ESPE), was bonded to each of the treated surfaces as per the manufacturer's instructions to obtain a 4x4x4x8mm dentin-composite NTP specimens. The specimens were stored in water for 24h at 37°C and tested to determine Kic. The data was analyzed using Levene's test for normality, two-way univariate analysis of variance (ANOVA), and Bonferroni tests for multiple means comparisons. A significance level of 0.05 was used for all tests. Results: While Adper Prompt L-pop and Clearfil SE achieved the highest Kic values for both age groups, Prime & Bond NT showed the lowest values. SEM observations of fractured samples revealed differences in fracture path. No statistically significant differences were observed between age groups. Conclusions: The Kic values of the four dental bonding systems were not affected by age. Furthermore, statistically significant differences were observed between the Kic values of the four bonding systems, regardless of the age of the dentin.Dentistry, Faculty ofGraduat

Parathyroid hormone mediates hematopoietic cell expansion through interleukin-6.

Parathyroid hormone (PTH) stimulates hematopoietic cells through mechanisms of action that remain elusive. Interleukin-6 (IL-6) is upregulated by PTH and stimulates hematopoiesis. The purpose of this investigation was to identify actions of PTH and IL-6 in hematopoietic cell expansion. Bone marrow cultures from C57B6 mice were treated with fms-like tyrosine kinase-3 ligand (Flt-3L), PTH, Flt-3L plus PTH, or vehicle control. Flt-3L alone increased adherent and non-adherent cells. PTH did not directly impact hematopoietic or osteoclastic cells but acted in concert with Flt-3L to further increase cell numbers. Flt-3L alone stimulated proliferation, while PTH combined with Flt-3L decreased apoptosis. Flt-3L increased blasts early in culture, and later increased CD45(+) and CD11b(+) cells. In parallel experiments, IL-6 acted additively with Flt-3L to increase cell numbers and IL-6-deficient bone marrow cultures (compared to wildtype controls) but failed to amplify in response to Flt-3L and PTH, suggesting that IL-6 mediated the PTH effect. In vivo, PTH increased Lin(-) Sca-1(+)c-Kit(+) (LSK) hematopoietic progenitor cells after PTH treatment in wildtype mice, but failed to increase LSKs in IL-6-deficient mice. In conclusion, PTH acts with Flt-3L to maintain hematopoietic cells by limiting apoptosis. IL-6 is a critical mediator of bone marrow cell expansion and is responsible for PTH actions in hematopoietic cell expansion

IL-6 mediates the <i>ex vivo</i> and <i>in vivo</i> PTH effects.

<p>(A–B) Whole bone marrow was isolated from wild-type (WT) mice and seeded at 1.8×10⁵ cells/cm² in the presence or absence of Flt-3L (100 ng/ml) or PTH (10 nM), a combination of both, or vehicle only control, with and without IL-6 (10 ng/ml). Non-adherent (A), and adherent (B), cells were harvested and enumerated using trypan blue exclusion at day 8. Data are mean ± SEM of 2 experiments performed in duplicate *<i>p</i><0.05 versus vehicle/vehicle, <i>** p</i><0.05 versus vehicle/Flt-3L. (C–D) Whole bone marrow was isolated from wild-type or IL-6 deficient mice (IL-6 KO) and seeded at 1.8×10⁵ cells/cm² in the presence of Flt-3L (100 ng/ml), PTH (10 nM), a combination of PTH and Flt-3L, or vehicle only control. Non-adherent (C) and adherent (D) cells were harvested and enumerated using trypan blue exclusion at day 8 of culture. Data are mean ± SEM of 2 experiments performed in duplicate. *<i>p</i><0.05 versus vehicle (wild-type cells) <i>**p</i><0.05 versus Flt-3L (wild-type cells) <i>***p</i><0.05 IL6-KO cells versus wild-type cells of the respective treatment group. Whole bone marrow was isolated from wild-type mice and seeded at 1.8×10⁵ cells/cm² in the presence or absence of Flt-3L (100 ng/ml) or PTH (10 nM), a combination of both. One hour after cells were plated vehicle (control) or a STAT-3 inhibitor, cucurbitacin (20 nM) was added to the culture. Non-adherent cells were harvested and enumerated using trypan blue exclusion at day 8 of culture (E). Data are mean ± SEM, from one of two experiments performed with similar results, *<i>p</i><0.05 versus vehicle of the respective group, <i>**p</i><0.05 versus Flt-3L of the respective group, *<i>**p</i><0.05 vehicle versus cucurbitacin in the combined Flt-3L and PTH groups. (F) Four-day-old wild-type and IL-6-deficient mice (n≥5/group) were treated daily with 50 µg/kg PTH or vehicle for 3 weeks. Bone marrow was isolated and flow cytometric analyses of Annexin V⁺ cells were performed. Fold induction of Annexin V+ cells measured as treatment over vehicle (control) of the respective phenotype. *<i>p</i><0.05 versus vehicle of the respective phenotype.</p