Biochemical assessment of gonadal function during maturation in girls and in adult women can be troublesome. With the recent advent of specific assays for the gonadal peptides inhibin A and inhibin B, it might be possible to achieve a clearer picture of events. We therefore determined serum levels of inhibin A, inhibin B, FSH, LH and estradiol in a cross-sectional study of 403 healthy schoolgirls (aged 6 -20 yr) in relation to age and stage of puberty and in 181 healthy nonpregnant women (aged 20-32 yr) in relation to stage of the menstrual cycle. In addition, inhibin A and inhibin B were measured daily throughout the menstrual cycle in 10 healthy adult women. Levels of inhibin B are low or undetectable in prepubertal girls (median, 26.5 pg/mL; 95% prediction interval, <20-100 pg/mL), increase sharply through pubertal stage II to peak in stage III (median, 84 pg/mL; 95% prediction interval, 28-227 pg/mL) and thereafter decline through pubertal stages IV and V. These changes presumably reflect increasing ovarian stimulation through early puberty, resulting in an increased number of developing follicles, follicles reaching a later stage of development before undergoing atresia, or both. Declining levels in late puberty and adulthood probably reflect the onset of the menstrual cycle and the subsequent appearance of the luteal phase, where inhibin B levels are low. Inhibin A levels are undetectable or very low in early puberty (median, <7 pg/mL; 95% prediction interval, <7-14) pg/mL), increasing gradually through pubertal stages to reach their highest values in adult women (median, 21.5 pg/mL; 95% prediction interval, <7-129 pg/mL). Levels of inhibin A greater than 19 pg/mL are only seen in postmenarcheal girls in puberty and in adult women, again consistent with inhibin A being primarily produced by the corpus luteum. Determining cut-off levels of serum inhibin B regarding whether a girl had entered puberty resulted in similar (low) sensitivities and specificities as those found for cut-off levels of LH or estradiol due to the large overlap between serum values in Tanner stages I and II. Correlations between inhibin A and inhibin B and FSH, LH, and estradiol within pubertal stages are presented. In early puberty both inhibin A and inhibin B correlated positively with LH and FSH. In late puberty inhibin A correlated negatively with FSH and did not correlate with LH; inhibin B still correlated positively with both FSH and LH, now most strongly with FSH. In adult women during the menstrual cycle, serum inhibin B levels increased during the follicular phase, indicating the greatest production by follicles in early stages of development. In contrast, serum inhibin A levels peaked during the luteal phase, indicating the greatest production by the corpus luteum. In conclusion, serum inhibin A and inhibin B levels in normal puberty in girls show consistency with our knowledge of the manner in which these hormones are secreted within the menstrual cycle in adult women. The presented reference values may be of use in the clin...
BackgroundMycoplasma bovis (M. bovis) is an emerging bovine pathogen, leading to significant economic losses in the livestock industry worldwide. Infection can result in a variety of clinical signs, such as arthritis, pneumonia, mastitis and keratoconjunctivitis, none of which are M. bovis-specific. Laboratory diagnosis is therefore important. Serological tests to detect M. bovis antibodies is considered an effective indicator of infection in a herd and often used as a herd test. Combined with clinical judgement, it can also be used to implement control strategies and/or to estimate the disease prevalence within a country. However, due to lack of harmonisation of approaches to testing, and serological tests used by different laboratories, comparisons of prevalence data between countries is often difficult. A network of researchers from six European countries designed and participated in an inter-laboratory trial, with the aim of evaluating the sensitivity (Se) and specificity (Sp) of two commercially available ELISA tests (ID Screen® ELISA (IDvet) and BIO K302 ELISA (BIO-X Diagnostics)) for diagnosis of M. bovis infection. Each laboratory received a blinded panel of bovine sera and tested independently, according to manufacturer’s instructions. Western blot analyses (WB) performed by one of the participating laboratories was used as a third diagnostic test in the statistical evaluation of Se and Sp values using latent class analysis.ResultsThe Se of WB, the ID Screen® ELISA and the BIO K302 ELISA were determined to be 91.8, 93.5 and 49.1% respectively, and corresponding Sp of the three tests were 99.6, 98.6 and 89.6%, respectively.ConclusionsThe present study is, to our knowledge, the first to present an inter-laboratory comparison of the BIO K302 ELISA and the ID Screen® ELISA. Based on our results, the ID Screen® ELISA showed high consistency with WB and performed with higher precision and accuracy than the BIO K302 ELISA.
Background The cytokine profile of atopic dermatitis (AD) depends on age, ethnicity, and disease severity. This study examined biomarkers in children with AD collected by tape strips and skin biopsies, and examined whether the levels differed with filaggrin genotype, disease severity, and food allergy. Methods Twenty‐five children aged 2–14 years with AD were clinically examined. Skin biopsies were collected from lesional skin and tape strips were collected from lesional and non‐lesional skin. We analyzed natural moisturizing factor (NMF) and 17 immune markers represented by mRNA levels in skin biopsies and protein levels in tape strips. Common filaggrin gene mutations were examined in all children. Results The cytokine profile in lesional skin was dominated by a T helper (Th) 2 response in skin biopsies, and by a general increase in innate inflammation markers (interleukin (IL)‐1α, IL‐1β, IL‐8, IL‐18) along with TARC and CTACK in tape strips. The levels of TARC, CTACK, IL‐8, IL‐18 showed significant correlation with AD severity in both lesional and non‐lesional tape stripped skin, while no significant correlations were observed in skin biopsy data. In tape strips from lesional and non‐lesional skin, the levels of NMF and selected cytokines differed significantly between children with and without FLG mutations and food allergy. Conclusion Sampling of the stratum corneum with non‐invasive tape strips can be used to identify biomarkers that are associated with disease severity, food allergy and FLG mutations. Skin biopsies showed robust Th2 signature but was inferior for association analysis regarding severity.
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