Detection of simulated incipient furcation involvement by CBCT: an in vitro study using pig mandibles

The aim of the present study was to test the reproducibility, sensitivity, and specificity of cone-beam computed tomography (CBCT) in detecting incipient furcation involvement. Fifteen macerated pig mandibles, with intact second molar teeth and preserved adjacent cortical areas, were used. Simulated lesions were created in the furcation region of these teeth by applying 70% perchloric acid in up to four possible buccal/lingual sites in the right/left sides of each mandible. The mandibles were then submitted to a CBCT scan. Two blinded and calibrated experienced oral and maxillofacial radiologists interpreted the exams. Furcation involvement was also assessed in the regions without simulated lesions. CBCT showed high levels of accuracy, ranging from 78% to 88%. The variations in Kappa values for intra- and inter-observer agreement (0.41-0.59) were considered moderate. CBCT can be considered a reliable and accurate method for detecting incipient furcation involvement.

Performance of fluorescence-based and conventional methods of occlusal caries detection in primary molars - an in vitro study

International Journal of Paediatric Dentistry 2012; 22: 459466 Aim. This in vitro study aimed to test the performance of fluorescence-based methods in detecting occlusal caries lesions in primary molars compared to conventional methods. Design. Two examiners assessed 113 sites on 77 occlusal surfaces of primary molars using three fluorescence devices: DIAGNOdent (LF), DIAGNOdent pen (LFpen), and fluorescence camera (VistaProof-FC). Visual inspection (ICDAS) and radiographic methods were also evaluated. One examiner repeated the evaluations after one month. As reference standard method, the lesion depth was determined after sectioning and evaluation in stereomicroscope. The area under the ROC curve (Az), sensitivity, specificity, and accuracy of the methods were calculated at enamel (D1) and dentine caries (D3) lesions thresholds. The intra and interexaminer reproducibility were calculated using the intraclass correlation coefficient (ICC) and kappa statistics. Results. At D1, visual inspection presented higher sensitivities (0.970.99) but lower specificities (0.180.25). At D3, all the methods demonstrated similar performance (Az values around 0.90). Visual and radiographic methods showed a slightly higher specificity (values higher than 0.96) than the fluorescence based ones (values around 0.88). In general, all methods presented high reproducibility (ICC higher than 0.79). Conclusions. Although fluorescence-based and conventional methods present similar performance in detecting occlusal caries lesions in primary teeth, visual inspection alone seems to be sufficient to be used in clinical practice.

Molecular detection of Streptococcus agalactiae in bovine raw milk samples obtained directly from bulk tanks

Mastitis is the most common infectious disease affecting dairy cattle; in addition, it remains the most economically important disease of dairy industries around the world. Streptococcus agalactiae, a contagious pathogen associated with subclinical mastitis, is highly infectious. This bacterium can cause an increase in bulk tank bacterial counts (BTBC) and bulk tank somatic cell counts (BTSCC). The microbiological identification of S. agalactiae in samples from bulk tanks is an auxiliary method to control contagious mastitis. Thus, there are some limitations for time-consuming cultures or identification methods and additional concerns about the conservation and transport of samples. Bulk tank samples from 247 dairy farms were cultured and compared through polymerase chain reaction (PCR), directed to 16S rRNA genes of S. agalactiae, followed by BTBC and S. agalactiae isolation. The mean value of BTBC was 1.08 x 10(6) CFU mL(-1) and the bacterium was identified through the microbiological method in 98 (39.7%; CI95% = 33.8-45.9%) and through PCR in 110 (44.5%; CI95% = 38.5-50.8%) samples. Results indicated sensitivity of 0.8571 +/- 0.0353 (CI95% = 0.7719-0.9196) and specificity of 0.8255 +/- 0.0311 (CI95% = 0.7549-0.8827). The lack of significant difference between microbiological and molecular results (kappa = 0.6686 +/- 0.0477 and CI95% = 0.5752-0.7620) indicated substantial agreement between the methods. This suggests that PCR can be used for bulk tank samples to detect contagious mastitis caused by S. agalactiae. (C) 2011 Elsevier Ltd. All rights reserved.

Accuracy of positron emission tomography/computed tomography and clinical assessment in the detection of complete rectal tumor regression after neoadjuvant chemoradiation Long-Term Results of a Prospective Trial (National Clinical Trial 00254683)

BACKGROUND: Neoadjuvant chemoradiation (CRT) therapy may result in significant tumor regression in patients with rectal cancer. Patients who develop complete tumor regression have been managed by treatment strategies that are alternatives to standard total mesorectal excision. Therefore, assessment of tumor response with positron emission tomography/computed tomography (PET/CT) after neoadjuvant treatment may offer relevant information for the selection of patients to receive alternative treatment strategies. METHODS: Patients with clinical T2 (cT2) through cT4NxM0 rectal adenocarcinoma were included prospectively. Neoadjuvant therapy consisted of 54 grays of radiation and 5-fluorouracil-based chemotherapy. Baseline PET/CT studies were obtained before CRT followed by PET/CT studies at 6 weeks and 12 weeks after the completion of CRT. Clinical assessment was performed at 12 weeks after CRT completion. PET/CT results were compared with clinical and pathologic data. RESULTS: In total, 99 patients were included in the study. Twenty-three patients were complete responders (16 had a complete clinical response, and 7 had a complete pathologic response). The PET/CT response evaluation at 12 weeks indicated that 18 patients had a complete response, and 81 patients had an incomplete response. There were 5 false-negative and 10 false-positive PET/CT results. PET/CT for the detection of residual cancer had 93% sensitivity, 53% specificity, a 73% negative predictive value, an 87% positive predictive value, and 85% accuracy. Clinical assessment alone resulted in an accuracy of 91%. PET/CT information may have detected misdiagnoses made by clinical assessment alone, improving overall accuracy to 96%. CONCLUSIONS: Assessment of tumor response at 12 weeks after CRT completion with PET/CT imaging may provide a useful additional tool with good overall accuracy for the selection of patients who may avoid unnecessary radical resection after achieving a complete clinical response. Cancer 2012;35013511. (C) 2011 American Cancer Society.

Serological detection of Plasmodium vivax malaria using recombinant proteins corresponding to the 19-kDa C-terminal region of the merozoite surface protein-1

Abstract Background Serological tests to detect antibodies specific to Plasmodium vivax could be a valuable tool for epidemiological studies, for screening blood donors in areas where the malaria is not endemic and for diagnosis of infected individuals. Because P. vivax cannot be easily obtained in vitro, ELISA assays using total or semi-purified antigens are rarely used. Based on this limitation, we tested whether recombinant proteins representing the 19 kDa C-terminal region of the merozoite surface protein-1 of P. vivax (MSP119) could be useful for serological detection of malaria infection. Methods Three purified recombinant proteins produced in Escherichia coli (GST-MSP119, His6-MSP119 and His6-MSP119-PADRE) and one in Pichia pastoris (yMSP119-PADRE) were compared for their ability to bind to IgG antibodies of individuals with patent P. vivax infection. The method was tested with 200 serum samples collected from individuals living in the north of Brazil in areas endemic for malaria, 53 serum samples from individuals exposed to Plasmodium falciparum infection and 177 serum samples from individuals never exposed to malaria. Results Overall, the sensitivity of the ELISA assessed with sera from naturally infected individuals was 95%. The proportion of serum samples that reacted with recombinant proteins GST-MSP119, His6-MSP119, His6-MSP119-PADRE and yMSP119-PADRE was 90%, 93.5%, 93.5% and 93.5%, respectively. The specificity values of the ELISA determined with sera from healthy individuals and from individuals with other infectious diseases were 98.3% (GST-MSP119), 97.7% (His6-MSP119 and His6-MSP119-PADRE) or 100% (yMSP119-PADRE). Conclusions Our study demonstrated that for the Brazilian population, an ELISA using a recombinant protein of the MSP119 can be used as the basis for the development of a valuable serological assay for the detection of P. vivax malaria.

Impact of the rapid antigen detection test in diagnosis and treatment of acute pharyngotonsillitis in a Pediatric emergency room

OBJECTIVE: To evaluate the impact of the routine use of rapid antigen detection test in the diagnosis and treatment of acute pharyngotonsillitis in children. METHODS: This is a prospective and observational study, with a protocol compliance design established at the Emergency Unit of the University Hospital of Universidade de São Paulo for the care of children and adolescents diagnosed with acute pharyngitis. RESULTS: 650 children and adolescents were enrolled. Based on clinical findings, antibiotics would be prescribed for 389 patients (59.8%); using the rapid antigen detection test, they were prescribed for 286 patients (44.0%). Among the 261 children who would not have received antibiotics based on the clinical evaluation, 111 (42.5%) had positive rapid antigen detection test. The diagnosis based only on clinical evaluation showed 61.1% sensitivity, 47.7% specificity, 44.9% positive predictive value, and 57.5% negative predictive value. CONCLUSIONS: The clinical diagnosis of streptococcal pharyngotonsillitis had low sensitivity and specificity. The routine use of rapid antigen detection test led to the reduction of antibiotic use and the identification of a risk group for complications of streptococcal infection, since 42.5% positive rapid antigen detection test patients would not have received antibiotics based only on clinical diagnosis.

A quantitative TaqMan PCR assay for the detection of Ureaplasma diversum

Ureaplasma diversum in veterinary studies is an undesirable microbe, which may cause infection in bulls and may result in seminal vesiculitis, balanopostitis, and alterations in spermatozoids, whereas in cows, it may cause placentitis, fetal alveolitis, abortion, and birth of weak calves. U. diversum is released through organic secretions, especially semen, preputial and vaginal mucus, conjunctival secretion, and milk. The aim of the present study was to develop a TaqMan probe, highly sensitive and specific quantitative PCR (qPCR) assay for the detection and quantification of U. diversum from genital swabs of bovines. Primers and probes specific to U. diversum 16S rRNA gene were designed. The specificity, detection limit, intra- and inter-assay variability of qPCR to detect this ureaplasma was compared with the results of the conventional PCR assay (cPCR). Swabs of vaginal mucus from 169 cows were tested. The qPCR assay detected as few as 10 copies of U. diversum and was 100-fold more sensitive than the cPCR. No cross-reactivity with other Mollicutes or eubacteria was observed. U. diversum was detected in 79 swabs (46.42%) by qPCR, while using cPCR it was detected in 42 (25%) samples. The difference in cPCR and qPCR ureaplasma detection between healthy and sick animals was not statistically significant. But the U. diversum load in samples from animals with genital disorders was higher than in healthy animals. The qPCR assay developed herein is highly sensitive and specific for the detection and quantification of U. diversum in vaginal bovine samples.