Thyroid function and thyroid autoimmunity in apparently healthy pregnant and non-pregnant Mexican women.

BACKGROUND: Thyroid disorders are common in women of reproductive age, and thyroid dysfunction during pregnancy has been associated with adverse outcomes for mother and child. Thyroid function and thyroid function tests (TFTs) can be influenced by a variety of factors, such as ethnicity, the presence of autoimmune thyroid disease (AITD), dietary iodine intake, pregnancy, and methodological differences. However, no large-scale studies have been published which examine TFTs and prevalence of AITD in Mexican pregnant women and women of reproductive age. METHODS: TFTs and thyroid autoantibody testing were performed on 660 pregnant and 104 non-pregnant women from Mérida, Yucatán, Mexico. After removal of thyroid autoantibody positive individuals and women with thyroid stimulating hormone (TSH) >4.94 mIU/L, reference intervals were calculated for TFT for non-pregnant women and pregnant women by trimester. RESULTS: Anti-thyroidperoxidase antibodies (TPO-Ab) and/or anti-thyroglobulin antibodies (Tg-Ab) were positive in 14.4% and 13.5% of non-pregnant and pregnant women, respectively. TSH values were significantly higher in women who were positive for TPO-Ab and co-positive for TPO-Ab and Tg-Ab. TSH values were also significantly higher in Tg-Ab positive pregnant women. Other TFTs were not significantly different based on antibody status. Using antibody negative women, reference intervals were determined for TFTs in pregnant (gestational age-specific) and non-pregnant women. CONCLUSIONS: Laboratory evidence of AITD is common in this population of Mexican pregnant and non-pregnant women. TFT results and reference intervals are influenced by pregnancy and thyroid autoimmunity. For optimal interpretation of TFT results, gestational age-specific reference intervals established using a local patient population should be used.

Longitudinal evaluation of thyroid autoimmunity and function in pregnant Korean women.

BACKGROUND: Maternal thyroid dysfunction during pregnancy has been associated with adverse outcomes for both the mother and child. For this reason, it is important to understand thyroid status in pregnant women. However, there are relatively few published studies that examine thyroid function tests (TFT) and thyroid autoimmunity in non-Western pregnant women. METHODS: Serum samples were longitudinally collected throughout pregnancy from 108 Korean women. TFT, thyroid peroxidase antibodies (TPO-Ab), and thyroglobulin antibodies (Tg-Ab) testing was performed. The impact of gestational age on TPO-Ab and Tg-Ab levels was evaluated and gestational age-specific reference intervals for TFT were established in antibody negative women. RESULTS: In the first trimester, TPO-Ab and Tg-Ab were positive in 13.9% and 16.7% of women, respectively. For antibody positive women, median autoantibody levels for TPO-Ab and Tg-Ab dropped from first trimester to near term (133.7-10.5 IU/mL, and 162.1-21.9 IU/mL, respectively). Antibody status influenced thyroid stimulating hormone (TSH) during the first trimester, and TSH, free T4 (FT4) and total T4 (TT4) in the early second trimester. Later in gestation, no significant differences in TFT were found based on antibody status. Gestational age-specific reference intervals for TFT were calculated in antibody negative women. CONCLUSIONS: Laboratory evidence of autoimmune thyroid disease (AITD) is common in this population of pregnant Korean women. Antibody status influences TFT values in the first and early second trimester. Thyroid autoantibody status and titer change in an individual-specific manner throughout pregnancy. Gestational age-specific reference intervals should be utilized for interpretation of TFT results in pregnant women.

Can evaluation of a dental procedure at the outset of learning predict later performance at the preclinical level? A pilot study.

The purpose of this study was to examine the effectiveness of conventional pre-clinical training in dentistry and to determine if evaluation of a dental procedure at the beginning of dental training can be a predictor for future performance. A group of second year dental students with no previous experience in operative dentistry were asked to prepare a conventional class I cavity on a lower first molar typodont. Their first preparation was carried out after an introductory lecture and a demonstration and their second at the end of conventional training. The prepared typodonts were coded and blindly scored for the traditional assessment criteria of outline form, retention form, smoothness, cavity depth and cavity margin angulation. Once the codes were broken, a paired t-test was used to compare the difference between the means of before and after scores (P<0.0001) and a Pearson's linear correlation to test the association (r=0.4). From the results of this study, we could conclude that conventional preclinical training results in a significant improvement in the manual skills of the dental students and that the dental procedure used had only a limited predictive value for later performance at the preclinical level.

The reproducibility and accuracy of internal fit of Cerec 3D CAD/CAM all ceramic crowns.

The objective of this study was to evaluate the reproducibility and accuracy of internal fit using Cerec 3D CAD/CAM (computer aided design/computer aided manufacturing) all-ceramic crowns and to investigate the proximal contact point areas between the crowns and neighbouring teeth, in terms of location and the presence or absence of contact. A total of 48 crowns were milled and divided into two groups of twenty-four each. One group consisted of testing a Control die and the other group consisted of testing single Replica stone die duplicates of the Control die. The Internal Marginal Gap, Axio-Occlusal Transition Gap and Occlusal Gap were measured on each crown in both groups. No significant differences were identified between the mean thickness of the Marginal Gap, the Axio-Occlusal Transition Gap and the Occlusal Gap of the Control die when compared with the Replica dies indicating uniformity and consistency of the accuracy of fit and therefore die replication.

A long-term follow up of spontaneously healed root fractures later subjected to orthodontic forces - two case reports.

There is evidence that many dental injuries which result in root fractures may not require active treatment in cases where the coronal fragment is minimally displaced and does not exhibit clinical signs or symptoms. This paper discusses two individual cases where spontaneous root fracture healing was observed and this healing was apparently not compromised by later orthodontic tooth movement. The observation periods for the two cases were 13 and 18 years since the original root fractures occurred.

The selection of adhesive systems for resin-based luting agents.

The use of resin-based luting agents is ever expanding with the development of adhesive dentistry. A multitude of different adhesive systems are used with resin-based luting agents, and new products are introduced to the market frequently. Traditional adhesives generally required a multiple step bonding procedure prior to cementing with active resin-based luting materials; however, combined agents offer a simple application procedure. Self-etching 'all-in-one' systems claim that there is no need for the use of a separate adhesive process. The following review addresses the advantages and disadvantages of the available adhesive systems used with resin-based luting agents.

Single unit CAD/CAM restorations: a literature review.

Computer-aided design/computer-aided manufacture (CAD/CAM) has been used in dentistry since 1987. Since then, many CAD/CAM systems have been described, which enable the production of chair-side single unit dental restorations. These restorations are of comparable quality to those made by conventional techniques and have some specific advantages, including rapid production, improved wear properties, decreased laboratory fee and improved cross infection control. This literature review investigates the evidence base for the use of single unit CAD/CAM restorations. Materials, marginal gap, aesthetics, post-operative sensitivity, cementation, cost-effectiveness and longevity are discussed.

Recombinant LH supplementation in patients with a relative reduction in LH levels during IVF/ICSI cycles: A prospective randomized controlled trial.

PURPOSE: The aim of this study was to assess the use of recombinant luteinizing hormone (rLH) supplementation in patients who experience a reduction in LH concentration during controlled ovarian hyperstimulation (COH) for IVF/ICSI. METHODS: A multi-center prospective randomized controlled trial (RCT) was performed over three years. Two hundred and forty patients aged between 24 and 42 years undergoing IVF/ICSI treatment with a long down regulation (LDR) protocol were recruited. LH was measured on the day FSH was started and again 6days later. 100 patients had a 50% or greater reduction in LH levels and these were randomized to receive either recombinant LH (rLH) supplementation (group 1, n=43) or no additional rLH supplementation (group 2, n=57). Group 1 received rLH 75IU daily from day 7 of FSH stimulation to the day of HCG trigger. RESULTS: There were no differences in either live birth or clinical pregnancy rates per embryo transfer between the two groups (27.8% vs. 37.0%, p=0.39, RR=0.75, 95%CI 0.39-1.44 and 36.1% vs. 43.5% p=0.51, RR=0.84, 95%CI 0.5-1.48, respectively). CONCLUSION: In conclusion the addition of rLH in patients with a relative reduction in serum LH concentration during COH for IVF/ICSI did not improve live birth or clinical pregnancy rates. However the results were not conclusive and further large well-designed RCTs are required to confirm these findings.

'We're having trouble conceiving...'.

BACKGROUND: The growing trend for Australian women to delay childbearing has a significant impact on their individual fertility and the consequent need for assisted reproductive technology. OBJECTIVE: This article defines infertility and highlights typical male, female, and unexplained combined causes of infertility. Initial fertility investigations best undertaken in general practice are outlined, and suggestions on when to refer a couple to a fertility specialist is clarified. DISCUSSION: Initial assessment of the subfertile couple is best managed by the general practitioner whose relationship can facilitate quick understanding of how long the couple has been trying to conceive, age, and medical history. The woman can then undergo simple global blood and hormone tests while a semen analysis is appropriate for the man. On review, any abnormal tests can indicate referral to a fertility specialist for review and management.

Complex reference value distributions and partitioned reference intervals across the pediatric age range for 14 specialized biochemical markers in the CALIPER cohort of healthy community children and adolescents.

BACKGROUND: The CALIPER program has previously reported a comprehensive database of pediatric reference intervals for 63 biochemical and immunochemical markers. Here, covariate-stratified reference intervals were determined for a number of special assays not previously reported. METHODS: A total of 1917 healthy children and adolescents were recruited and serum concentrations of 14 biochemical markers were measured using the Abbott Architect ci4100 system. Age and gender partitions were statistically determined, outliers removed and reference intervals calculated using CSLI C28-A3 guidelines. RESULTS: Many analytes showed dynamic changes in concentration requiring at least 3 age partitions. Unique intervals were required within the first year of life for: pancreatic amylase, C-peptide, ceruloplasmin, insulin, ß-2-microglobulin, cystatin C, dehydroepiandrosterone sulfate (DHEA-S), and α-1-glycoprotein. Cholinesterase, cholinesterase-dibucaine number, and immunoglobulin E required only 2 age partitions and α-1-antitrypsin required only one. Anti-CCP and anti-TPO levels were below the detection limit of the assay. Some analytes including insulin and DHEA-S required additional gender partitions for specific age groups. CONCLUSIONS: Complex profiles were observed for endocrine and special chemistry markers, requiring establishment of age- and gender-specific reference intervals. These updated reference intervals will allow improved laboratory assessment of pediatric patients but should be validated for each analytical platform and local population as recommended by CLSI.

Single-arm, observational study of the ease of use of a redesigned pen device to deliver recombinant human follicle-stimulating hormone (follitropin alfa) for assisted reproductive technology treatment.

PURPOSE: Evaluation of patients' ease of use of the redesigned, disposable, ready-to-use follitropin alfa pen during controlled ovarian stimulation for assisted reproductive technology. METHODS: This single-center, observational, open-label, single-arm study recruited infertile normo-ovulatory women (aged 18-45 years). Nurses trained patients to self-administer recombinant human follicle-stimulating hormone daily using the follitropin alfa pen (300 IU, 450 IU, and 900 IU). Before treatment, patients completed Questionnaire A. Following self-administered treatment, on stimulation days 5-6 and 7-8 (within a day of receiving recombinant human chorionic gonadotropin), patients completed Questionnaire B. Nurses completed an ease-of-learning/teaching questionnaire. The primary endpoint was proportion of patients rating the pen as "easy/very easy" to use (Questionnaire B) on the final visit before recombinant human chorionic gonadotropin. Secondary endpoints included: proportion of patients rating the follitropin alfa pen as easy to learn, use, prepare, deliver, and dispose of (Questionnaires A and B). Proportions (95% confidence intervals [CIs]) were provided for primary and secondary endpoints. Adverse events were reported descriptively. RESULTS: Eighty-six patients received recombinant human follicle-stimulating hormone. Of the 72 patients who had completed the overall assessment questions, 66 (91.7%; 95% CI =82.7%-96.9%) found the pen "easy" to use. Also, 70/86 (81.4%) patients "strongly agreed/agreed" that, overall, it was easy to learn how to use the pen; 72/86 (83.7%) "strongly agreed/agreed" that easily understandable, verbal information was provided; and 70/86 (81.4%) were confident about using the pen correctly. In total, 24/26 nurses (92.3%; 95% CI =74.9%-99.1%) rated the pen as easy to use. Clinical pregnancy rate/patient/cycle/embryo transfer was 37%. Twenty-six ovarian hyperstimulation syndrome events were reported (none severe; 16 patients [19%]); of these, 13 occurred at embryo transfer. CONCLUSION: In this observational study, patients had a high acceptance of the redesigned follitropin alfa pen, with most finding it very easy/easy to use. Assisted reproductive technology nurses found the pen very easy/easy to teach.

A Progress Report of the IFCC Committee for Standardization of Thyroid Function Tests.

BACKGROUND: The IFCC Committee for Standardization of Thyroid Function Tests aims at equivalence of laboratory test results for free thyroxine (FT4) and thyrotropin (TSH). OBJECTIVES: This report describes the phase III method comparison study with clinical samples representing a broad spectrum of thyroid disease. The objective was to expand the feasibility work and explore the impact of standardization/harmonization in the clinically relevant concentration range. METHODS: Two sets of serum samples (74 for FT4, 94 for TSH) were obtained in a clinical setting. Eight manufacturers participated in the study (with 13 FT4 and 14 TSH assays). Targets for FT4 were set by the international conventional reference measurement procedure of the IFCC; those for TSH were based on the all-procedure trimmed mean. The manufacturers recalibrated their assays against these targets. RESULTS: All FT4 assays were negatively biased in the mid- to high concentration range, with a maximum interassay discrepancy of approximately 30%. However, in the low range, the maximum deviation was approximately 90%. For TSH, interassay comparability was reasonable in the mid-concentration range, but worse in the pathophysiological ranges. Recalibration was able to eliminate the interassay differences, so that the remaining dispersion of the data was nearly entirely due to within-assay random error components. The impact of recalibration on the numerical results was particularly high for FT4. CONCLUSIONS: Standardization and harmonization of FT4 and TSH measurements is feasible from a technical point of view. Because of the impact on the numerical values, the implementation needs careful preparation with the stakeholders.

A radiographic analysis of implant component misfit.

PURPOSE: Radiographs are commonly used to assess the fit of implant components, but there is no clear agreement on the amount of misfit that can be detected by this method. This study investigated the effect of gap size and the relative angle at which a radiograph was taken on the detection of component misfit. Different types of implant connections (internal or external) and radiographic modalities (film or digital) were assessed. MATERIALS AND METHODS: Twelve internal-connection and 12 external-connection implant analogs with impression copings were assembled, with radiolucent washers interposed, to produce vertical misfits of 0, 12.7, 25, 38, 51, 63, 76, 88, 102, 114, 127, and 190 µm. A custom-made positioning apparatus was used to obtain radiographs of the components at angulations between 0 and 35 degrees. The images were randomized, and three experienced examiners assessed whether a gap was visible at the interface. Their responses were compared to the actual status of the samples, and a probability model was constructed to predict the likelihood of a correct answer at any combination of gap and angle. RESULTS: The relative angulation of the radiograph and the dimension of the gap were the most significant factors affecting an examiner's diagnostic ability. A 0-µm gap viewed at 0 degrees was the combination most accurately diagnosed. Implant component misfits as small as 12.7 µm were reliably detected with radiographs up to 5 degrees from the orthogonal projection; this was similar with configurations of 25 to 38 µm/10 degrees and 51 µm/15 degrees. There was good (inter-)examiner reliability. Neither the type of component used nor the radiographic media used influenced diagnostic ability. CONCLUSION: The angulation of the x-ray beam relative to implant components needs to be controlled when using radiographs to detect component misfit.

Canadian Laboratory Initiative on Pediatric Reference Interval Database (CALIPER): pediatric reference intervals for an integrated clinical chemistry and immunoassay analyzer, Abbott ARCHITECT ci8200.

OBJECTIVES: A comprehensive set of age- and gender-specific pediatric reference intervals is essential for accurate interpretation of laboratory tests in a pediatric setting. DESIGN AND METHODS: 1459 serum/plasma from children attending select outpatient clinics and deemed to be metabolically stable, were collected from five age groups; 0-12 months, 1-5 years, 6-10 years, 11-14 years and 15-20 years. Samples were analyzed for 24 chemistries and 15 immunoassays on ARCHITECT ci8200. RESULTS: Reference intervals were established according to CLSI/IFCC C28-P3 guidelines by the Robust statistical method. The ranges reflect the central 95% confidence intervals for the population tested. Age and gender were partitioned using the Harris-Boyd method. CONCLUSIONS: While these intervals are ci8200 method specific, they not only provide robust intervals for users of this system but are also useful for any laboratory requiring pediatric intervals if they can be shown to be transferable and if validated for the local patient population.

Thyroid autoimmunity and thyroid hormone reference intervals in apparently healthy Chinese adults.

BACKGROUND: Thyroid disorders are common, often go unrecognized, and when left untreated, can have serious public health implications. Dietary and ethnic differences are known to influence thyroid function. However, comparatively few studies have examined the prevalence of autoimmune thyroid disease (AITD) and thyroid function test (TFT) reference intervals in non-Western populations. METHODS: Sera were collected from 486 apparently healthy Chinese adults. Participants were classified as healthy based on physician review of metabolic testing and patient history. TFT (TSH, Free T4, Total T4, Free T3, Total T3, and T-Uptake), thyroid peroxidase autoantibodies (TPO-Ab), and thyroglobulin autoantibodies (Tg-Ab) were measured for all participants. RESULTS: TPO-Ab and Tg-Ab were found in 12.1% and 10.3% of participants, with higher prevalence found in women. Reference intervals were calculated for all TFT. Gender associated differences in mean values were noted for Total T4, Free T3, Total T3, and T-Uptake, but not for TSH and Free T4. CONCLUSIONS: Laboratory evidence of AITD is common in otherwise healthy Chinese adults. Women are significantly more likely to be positive for TPO-Ab and Tg-Ab, which is of particular concern for women of reproductive age. Reference values specific for the Chinese population were established for thyroid function tests in individuals without AITD.

Establishment of detailed reference values for luteinizing hormone, follicle stimulating hormone, estradiol, and progesterone during different phases of the menstrual cycle on the Abbott ARCHITECT analyzer.

During a normal menstrual cycle, serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol, and progesterone can vary widely between cycles for the same woman, as well as between different woman. Reliable reference values based on the local population are important for correct interpretation of laboratory results. The purpose of our study was to determine detailed reference values for these hormones throughout the menstrual cycle using the Abbott ARCHITECT system. From 20 volunteers (age 20-36 years) with normal cycles and no use of oral contraceptives, samples were taken every day during their cycle. Volunteers received three vaginal ultrasound examinations (days 10 and 13, and 1 or 2 days after ovulation) to measure follicular and corpus luteum development. Hormone levels were measured using the corresponding ARCHITECT assay and were synchronized to the LH peak. Median, and 5th and 95th percentile values were determined for each day of the cycle, as well as for early follicular (days -15 to -6), late follicular (days -5 to -1), LH peak (day 0), early luteal (+1 to +4), mid-luteal (days +5 to +9), and late luteal (days +10 to +14) phases of the cycle. Based on our data, we were able to establish detailed reference values for LH, FSH, estradiol, and progesterone, which should aid in the interpretation of results for these reproductive hormones in a variety of circumstances.

Prevalence of abnormal thyroid stimulating hormone and thyroid peroxidase antibody-positive results in a population of pregnant women in the Samara region of the Russian Federation.

Undiagnosed thyroid disease is a common problem with significant public health implications. This is especially true during pregnancy, when the health of both the mother and the developing child can be adversely affected by abnormal maternal thyroid function. Measurement of serum thyroid stimulating hormone (TSH) and thyroid peroxidase antibodies (TPO-Ab) are two common ways to assess maternal thyroid status. The objective of our study was to determine the prevalence of abnormal TSH and TPO-Ab tests in a population of pregnant women in the Samara region of the Russian Federation. Serum samples were obtained from 1588 pregnant women as part of their routine antenatal care. TSH and TPO-Ab were measured, and trimester-specific reference values for TSH (2.5-97.5 percentiles) were calculated using TPO-Ab-negative women. TSH results outside these ranges were considered abnormal; TPO-Ab levels outside the manufacturer's reference range (>12 IU/mL) were considered abnormal. Overall, the prevalence of abnormal results was 6.3% for TSH and 10.7% for TPO-Ab. High TSH (>97.5 trimester-specific percentile) and TPO-Ab-positive results were most common in the first trimester (5.7% and 13.8%, respectively). TSH levels were associated with gestational age and TPO-Ab status, and with maternal age in TPO-Ab-negative women. TPO-Ab status was associated with both maternal and gestational age. Women with TSH >2.5 mIU/L had a significantly increased risk of being TPO-Ab-positive, and this risk increased with age. Based on our data, we conclude that abnormal TSH and TPO-Ab are common in pregnant women of the Samara region. Given the association of thyroid dysfunction to adverse pregnancy outcomes, screening of this population for abnormal thyroid function should be considered.

A pilot study comparing the effectiveness of conventional training and virtual reality simulation in the skills acquisition of junior dental students.

The use of virtual reality (VR) in the training of operative dentistry is a recent innovation and little research has been published on its efficacy compared to conventional training methods. To evaluate possible benefits, junior undergraduate dental students were randomly assigned to one of three groups: group 1 as taught by conventional means only; group 2 as trained by conventional means combined with VR repetition and reinforcement (with access to a human instructor for operative advice); and group 3 as trained by conventional means combined with VR repetition and reinforcement, but without instructor evaluation/advice, which was only supplied via the VR-associated software. At the end of the research period, all groups executed two class 1 preparations that were evaluated blindly by 'expert' trainers, under traditional criteria (outline, retention, smoothness, depth, wall angulation and cavity margin index). Analyses of resulting scores indicated a lack of significant differences between the three groups except for scores for the category of 'outline form', for group 2, which produced significantly lower (i.e. better) scores than the conventionally trained group. A statistical comparison between scores from two 'expert' examiners indicated lack of agreement, despite identical written and visual criteria being used for evaluation by both. Both examiners, however, generally showed similar trends in evaluation. An anonymous questionnaire suggested that students recognized the benefits of VR training (e.g. ready access to assessment, error identification and how they can be corrected), but the majority felt that it would not replace conventional training methods (95%), although participants recognized the potential for development of VR systems in dentistry. The most common reasons cited for the preference of conventional training were excessive critical feedback (55%), lack of personal contact (50%) and technical hardware difficulties (20%) associated with VR-based training.