Mixed Sex Effects on the Second‐to‐Fourth Digit Ratio of Túngara Frogs (Engystomops pustulosus) and Cane Toads (Rhinella marina)

Sexual dimorphism in the ratio of digit lengths has been correlated to behavioral, physiological, and morphological traits in a variety of taxa. While sexual dimorphism in the second‐to‐fourth digit length ratio (2D:4D) is a well‐established indicator of prenatal androgen exposure in mammals, investigations into the patterns of 2D:4D and the drivers of such variation in other taxa are lacking. We used linear mixed effects models to gain a mechanistic understanding of the factors that drive variation in the scaling relationship between the lengths of the second and fourth digits in two species of anurans: túngara frogs (Engystomops pustulosus) and cane toads (Rhinella marina). We found evidence for sexual dimorphism of the 2D:4D scaling relationship on the front feet of túngara frogs, with female frogs having a larger ratio than males resulting from a relatively longer second digit on females. To our knowledge, this mammal‐like pattern of sex differences in digit ratio has not yet been reported for anurans. However, given the reduced number of digits on the front feet of anurans, and uncertainty about which digit was lost during evolutionary history, this apparent sexual dimorphism in the front feet of túngara frogs should be treated with caution. In contrast, we found no evidence of sexual dimorphism in 2D:4D on either the front or rear feet of cane toads. This study highlights ambiguities in 2D:4D across taxa and suggests that further research is needed to evaluate the effect of androgens on 2D:4D in animals other than placental mammals. Anat Rec, 299:421–427, 2016. © 2016 Wiley Periodicals, Inc.     

Patterns of Second‐to‐Fourth Digit Length Ratios (2D:4D) in Two Species of Frogs and Two Species of Lizards at La Selva,Costa Rica

It is now well documented that androgen and estrogen signaling during early development cause a sexual dimorphism in second‐to‐fourth digit length ratio (2D:4D). It is also well documented that males of mammalian species have a smaller 2D:4D than females. Although there are discrepancies among 2D:4D studies in birds, the consensus is that birds exhibit the opposite pattern with males having a larger 2D:4D than females. The literature currently lacks substantial information regarding the phylogenetic pattern of this trait in amphibians and reptiles. In this study, we examined 2D:4D in two species of frogs (Oophaga pumilio and Craugastor bransfordii) and two species of lizards (Anolis humilis and Anolis limifrons) to determine the existence and the pattern of the sexual dimorphism. Male O. pumilio and C. bransfordii displayed larger 2D:4D than females in at least one of their two forelimbs. Male A. humilis had larger 2D:4D than females in both hindlimbs, but smaller 2D:4D than females in both forelimbs. Male A. limifrons may also have smaller 2D:4D than females in the right forelimb. Finally, digit ratios were sometimes positively related to body length, suggesting allometric growth. Overall, our results support the existence of the 2D:4D sexual dimorphism in amphibians and lizards and add to the knowledge of 2D:4D trait patterning among tetrapods. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

Sexual Dimorphism in Titi Monkeys’ Digit (2D:4D) Ratio is Associated with Maternal Urinary Sex Hormones During Pregnancy

The second-to-fourth digit (2D:4D) ratio is a sexually-dimorphic biomarker for prenatal sex hormone exposure. We investigated whether titi monkeys (Plecturocebus cupreus) exhibit sexually-dimorphic 2D:4D ratio, and whether variation in 2D:4D ratio correlates with maternal testosterone and estrogen levels during early pregnancy. Subjects were 61 adult titi monkeys (32 males, 29 females). For 26 subjects, maternal urine samples were collected approximately 15–20 weeks before birth and assayed for testosterone and estrone conjugate (E₁C). Titi monkeys exhibited a human-like pattern of sexual dimorphism in right-hand 2D:4D ratio, with females exhibiting higher 2D:4D ratio than males (β = −0.29, p = 0.023). For left-hand 2D:4D ratio, high levels of maternal E₁C predicted low offspring 2D:4D ratio (β = −0.48, p = 0.009). For right-hand 2D:4D ratio, high levels of testosterone (β = −0.53, p = 0.005) and testosterone-to-E₁C ratio (β = −0.41, p = 0.028) predicted low offspring 2D:4D ratio. For 2D:4D ratio asymmetry (right-hand – left-hand), high levels of testosterone (β = −0.43, p = 0.03) and testosterone-to-E₁C ratio (β = −0.53, p = 0.003) predicted low (right-biased) asymmetry. This is the first report of sexually-dimorphic 2D:4D ratio in New World monkeys, and the results support a growing literature suggesting prenatal sex hormones may modulate offspring 2D:4D ratio.     

Females Have Larger Ratio of Second‐to‐Fourth Digits Than Males in Four Species of Salamandridae,Caudata

Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. It is considered to be a suitable biomarker of the in utero balance of fetal sex hormones, which affect early development of individua?s behavioral and morphological characteristics. In recent decades, digit ratio attracted a great attention in biology and psychology. However, for unmasking the biological basis of the phenomenon, extensive studies on non‐human animals are necessary. Despite it was hypothesized that digit ratio is well conserved in all Tetrapoda, and there exist studies on mammals, birds, and reptiles, there are only two such study on anuran amphibians. Therefore, the aim of this study is to investigate the 2D:4D in the most basal salamanders, Caudata. We have studied digit ratio in four species of newts: Triturus cristatus, Mesotriton alpestris, Lissotriton montandoni, and Lissotriton vulgaris, using museum collection. We used computerized measuring of each limb? photos. We have found out that, in M. alpestris, females 2D:4D of all four limbs were significantly larger than in males. In L. montandoni and L. vulgaris, only 2D:4D of rear limbs significantly differed, in females being larger. In T. cristatus, digit ratios of males and females did not statistically differ. Thus, the results confirmed our hypothesis that at least in M. alpestris, L. montandoni, and L. vulgaris, females seem to have larger 2D:4D comparing to males, the pattern known from most mammals and opposite to birds, reptiles and anuran amphibians. Anat Rec, 298:1424–1430, 2015. © 2015 Wiley Periodicals, Inc.     

The ratios of 2nd to 4th digit may be a predictor of schizophrenia in male patients

The production of androgens (mostly testosterone) during the early fetal stage is essential for the differentiation of the male brain. Some authors have suggested a relationship between androgen exposure during the prenatal period and schizophrenia. These two separate relationships suggest that digit length ratios are associated with schizophrenia in males. The study was performed in a university hospital between October 2012 and May 2013. One hundred and three male patients diagnosed with schizophrenia according to DSM‐IV using SCID‐I, and 100 matched healthy males, were admitted to the study. Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms (SANS) and Brief Psychiatric Rating Scale (BPRS) were used to assess schizophrenia symptoms. The second digit (2D) and fourth digit (4D) asymmetry index (AI), and the right‐ and left‐hand 2D:4D ratios were calculated. All parametric data in the groups were compared using an independent t‐test. The predictive power of the AI was estimated by receiver operating characteristics analysis. The 2D:4D AI was statistically significantly lower in the patient group than the healthy control comparison group. There were significant differences between the schizophrenia and the control groups in respect of left 2D:4D and right 2D:4D. There was no correlation between AI, left, or right 2D:4D, BPRS, or SAPS in the schizophrenia group. However, there was a negative correlation between left 2nd digit (L2D):4D and the SANS score. Our findings support the view that the 2D:4D AI can be used as a moderate indicator of schizophrenia. Even more simply, the right or left 2D:4D can be used as an indicator. L2D:4D could indicate the severity of negative symptoms. Clin. Anat. 28:551–556, 2015. © 2015 Wiley Periodicals, Inc.     

The Ratio of Second to Fourth Digit Length (2D:4D) and Coronary Artery Disease in a Han Chinese Population

Background: The association between index finger to ring finger length ratio (2D:4D) and cardiac disorders has been reported, however it has not been discussed in terms of coronary artery disease (CAD). We investigated whether 2D:4D could be used as a marker for predisposition to CAD as assessed by coronary angiography in Chinese men and women.Methods: This study included 1764 persons divided into 4 groups, 441 cases with CAD and 441 persons without CAD as control in each sex of the same age. Finger lengths were measured twice for both hands using electronic calipers. Student t test was used to detect the difference of 2D:4D among groups. The receiver operator characteristic curves (ROCs) were used to detect the diagnostic effect of 2D:4D for CAD.Results: There were no significant differences in age among the four groups. A significant difference of 2D:4D ratios between right and left hand were observed only in men in both control and CAD groups. On the right hand in the control group and on both hands in the CAD group, the 2D:4D ratios were higher in women than in men (all, P < 0.001). In men with CAD, mean 2D:4D was higher than mean 2D:4D in control men (right hand 0.962±0.042:0.927±0.038; left hand 0.950±0.044:0.934±0.048; both hands, P < 0.001), but this was not observed in women. No relationship was found between 2D:4D and age (all, P >0.05). The area under the curve of right hand 2D:4D in male was 0.72 (95% CI 0.683-0.753, p<0.001), while it was 0.602 (95% CI 0.565-0.639, p<0.001) in left hand.Conclusions: The present study showed an association between high 2D:4D ratio and CAD in both hands in men. There were no significant differences in mean 2D:4D between women with CAD and controls.     

No association between two candidate markers of prenatal sex hormones: Digit ratios (2D:4D and other) and finger‐ridge counts

The second‐to‐fourth digit ratio (2D:4D), putatively indexing prenatal androgen levels retrospectively, has become increasingly popular as an easily applied measure in research into the prenatal sex‐hormonal bases of behavior, health, and disease. However, its validity has not yet been conclusively demonstrated and in fact is currently debated, because validation tests of 2D:4D with other, prenatally established, presumed markers for prenatal sex‐hormone action have yielded mixed evidence or still are unavailable. Hence, the associations of 2D:4D with finger‐ridge counts, one such further under‐researched marker, were examined in this study. In a sample of 75 male and 75 female normal healthy adults, the six possible finger‐length ratios of the human hand (from 2D:3D to 4D:5D, including the classic 2D:4D ratio) were ascertained with two commonly used measurement methods (imaged‐based vs. fingers measured directly), along with two traditional dermatoglyphic traits (total and absolute finger‐ridge counts). Sex differences in finger‐length ratios (lower in men) generally were of moderate size (about .5 SD units), whereas those in finger‐ridge counts (higher in men) were small to negligible (about .2 SD units). Within‐sex analysis did not indicate theory compliant (i.e., negative) correlations between these two sets of traits that were consistent, noteworthy, or reliable. Finger‐length ratios and finger‐ridge counts are ontogenetically overlapping in their prenatal formation and anatomically adjacent. Hence, possible temporal and localized sex‐hormonal effects in prenatal life are unlikely to account for their nonassociation. The current findings cast some doubt on the validity of these retrospective pointers to prenatal androgen levels. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53: 69–78, 2011.     

Digit ratios (2D:4D), postnatal testosterone and eye contact in toddlers

Previous research has shown an association between eye contact and prenatal testosterone measured in amniocenteses samples. The purpose of this study was to test the association between eye contact and prenatal androgen action measured via second to fourth digit ratios (2D:4D ratios), and to explore the relationship between eye contact and postnatal testosterone levels. Participants included 72 children, between the ages of 18 and 24 months, and their parents. Salivary testosterone levels were obtained when children were 3-months old. At 18-months, 2D:4D ratios were measured and parent–child dyads participated in an 8-min play session that was recorded and later coded for duration and frequency of eye contact. Results indicated that larger 2D:4D ratios (indicative of lower androgen levels) significantly predicted longer duration and more frequency of eye contact, while postnatal testosterone levels were unrelated to eye contact. These novel findings suggest prenatal androgens may influence the emergence of social development.     

Women have Relatively Larger Brains than Men: A Comment on the Misuse of General Linear Models in the Study of Sexual Dimorphism

General linear models (GLM) have become such universal tools of statistical inference, that their applicability to a particular data set is rarely questioned. These models are designed to minimize residuals along the y‐axis, while assuming that the predictor (x‐axis) is free of statistical noise (ordinary least square regression, OLS). However, in practice, this assumption is often violated, which can lead to erroneous conclusions, particularly when two predictors are correlated with each other. This is best illustrated by two examples from the study of allometry, which have received great interest: (1) the question of whether men or women have relatively larger brains after accounting for body size differences, and (2) whether men indeed have shorter index fingers relative to ring fingers (digit ratio) than women. In depth analysis of these examples clearly shows that GLMs produce spurious sexual dimorphism in body shape where there is none (e.g. relative brain size). Likewise, they may fail to detect existing sexual dimorphisms in which the larger sex has the lower trait values (e.g. digit ratio) and, conversely, tend to exaggerate sexual dimorphism in which the larger sex has the relatively larger trait value (e.g. most sexually selected traits). These artifacts can be avoided with reduced major axis regression (RMA), which simultaneously minimizes residuals along both the x and the y‐axis. Alternatively, in cases where isometry can be established there are no objections against and good reasons for the continued use of ratios as a simple means of correcting for size differences. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.     

Markers aiding the diagnosis of chondroid tumors: an immunohistochemical study including osteonectin,bcl‐2, cox‐2, actin,calponin, D2‐40 (podoplanin), mdm‐2, CD117 (c‐kit), and YKL‐40

Chondroid tumors comprise a heterogenous group of benign to overt malignant neoplasms, which may be difficult to differentiate from one another by histological examination. A group of 43 such tumors was stained with nine relevant antibodies in an attempt to find consistent marker profile(s) for the different subgroups. Archival material from three extraskeletal myxoid chondrosarcomas, five chordomas, five chondromyxoid fibromas, five chondroblastomas and 25 chondrosarcomas was stained with antibodies against osteonectin, bcl‐2, cox‐2, actin, calponin, D2‐40 (podoplanin), mdm‐2, CD117 (c‐kit) and YKL‐40. All 25 chondrosarcomas showed a positive staining reaction for D2‐40, none for actin and CD117, and a partial reactivity for bcl‐2 (36%). Chondroblastomas (5/5) and chondromyxoid fibromas (2/5) were the only tumors with a positive reaction for actin, and all chondroblastomas (n=5) and extraskeletal myxoid chondrosarcomas (n=3) were positive for bcl‐2. In contrast to all other tumors, two of three extraskeletal myxoid chondrosarcomas were also positive for CD17 and negative for osteonectin, cox‐2, mdm‐2 and actin. All five chordomas were negative for D2‐40 and positive for mdm‐2 and YKL‐40. The diagnosis of chondrosarcoma may be aided by its positivity for D2‐40 and YKL‐40 and its lack of reactivity for actin and CD117. This should be seen in the light of no reaction for D2‐40 in chordomas and a corresponding lack of reaction for osteonectin, cox‐2, mdm‐2 and actin in extraskeletal myxoid chondrosarcomas. A convincing immunoreactivity for calponin and/or actin in chondromyxoid fibromas and chondroblastomas may also be helpful in differentiating these tumors from chondrosarcomas.     

The damage‐associated molecular pattern HMGB1 is elevated in human alcoholic hepatitis,but does not seem to be a primary driver of inflammation

The role of sterile inflammation caused by release of damage‐associated molecular patterns (DAMP) remains unclear in human alcoholic hepatitis (AH). The DAMP, high mobility group box‐1 protein (HMGB1) is released by tissue damage and inflammation. We aimed to investigate whether HMGB1 is a primary inflammatory driver in AH by determining HMGB1 serum levels and effects on inflammatory cells from AH patients. We measured serum HMGB1 in 34 AH patients and 10 healthy controls using ELISA. Toll‐like receptor 4 (TLR4) and CD14 expressions were assessed by flow cytometry on HMGB1‐stimulated peripheral blood mononuclear cells (PBMC) and ELISA was used to measure TNF‐α and IL‐1β in the supernatants. We observed 5‐fold higher serum levels of HMGB1 in AH patients at the day of diagnosis and day 30, but no associations to clinical outcome. HMGB1 stimulation increased the expression of TLR4 on CD14+‐monocytes compared with unstimulated cells in the AH patients. The TNF‐α and IL‐1β production in response to HMGB1 was diminished in AH patients. In conclusion, AH patients have increased levels of HMGB1 in their blood. This combined with an increased TLR4 expression, but an unaffected cytokine response to HMGB1 suggest that HMGB1 is not the primary driver of inflammation in AH.     

Cognitive‐Analytic Therapy in a Group: Reflections on a Dialogic Approach

Cognitive‐Analytic Therapy (CAT) (Ryle & Kerr, 2002 ) is a brief, integrative psychological therapy developed by Dr Anthony Ryle and others over the last 25 years. CAT is often used as an individual therapy for clients with personality disorder and is widespread within the NHS and private sectors in the UK and several countries abroad. CAT is being increasingly applied in group settings in the NHS. CAT, being at its heart a psychotherapy based on a relational understanding of human development, would seem to have much to offer in a group setting. This paper briefly reviews previous ways that the CAT model has been used in groups and then goes on to describe the author's experience of a one‐year group carried out in South‐West England. The therapeutic approach used adapts the CAT tools to a group setting, draws on CAT's dialogic underpinnings and shares some broader concepts with psychodynamic approaches.     

Trappin‐2/Elafin: a novel innate anti‐human immunodeficiency virus‐1 molecule of the human female reproductive tract

Trappin‐2/Elafin is a serine protease inhibitor that plays a major role as an anti‐inflammatory mediator at mucosal surfaces. In addition, Trappin‐2/Elafin has antibacterial activity against Gram‐positive and Gram‐negative bacterial and fungal pathogens. In this study we examined the production of Trappin‐2/Elafin by epithelial cells from the human upper and lower female reproductive tract as well as its activity as an anti‐human immunodeficiency virus (HIV)‐1 molecule. We found that primary uterine, Fallopian tube, cervical and ectocervical epithelial cells produce Trappin‐2/Elafin constitutively and that production of Trappin‐2/Elafin is enhanced following stimulation with Poly(I:C), especially by the uterine cells. Given the presence of Trappin‐2/Elafin in the reproductive tract, we tested the ability of recombinant Trappin‐2/Elafin to inhibit HIV‐1, an important sexually transmitted pathogen. We found that recombinant Trappin‐2/Elafin was able to inhibit both T‐cell‐tropic X4/IIIB and macrophage‐tropic R5/BaL HIV‐1 in a dose‐dependent manner. The inhibitory activity was observed when virus was incubated with Trappin‐2/Elafin but not when Trappin‐2/Elafin was added to cells either before infection or after infection. This suggests that the mechanism of inhibition is likely to be a direct interaction between HIV‐1 and Trappin‐2/Elafin. Additionally, we measured the levels of secreted Trappin‐2/Elafin in cervico‐vaginal lavages (CVL) from both HIV‐positive and HIV‐negative women and found that average levels of secreted Trappin‐2/Elafin were higher in the CVL from HIV‐negative women, although the values did not reach statistical significance. We also found that women at the secretory phase of the menstrual cycle produced more Trappin‐2/Elafin in CVL relative to women at the proliferative phase of the menstrual cycle. Our data suggest that Trappin‐2/Elafin might be an important endogenous microbicide of the female reproductive tract that is protective against HIV‐1.     

Inhibition of cleavage of the third component of human complement (C3) by its small cleavage fragment, C3a: inhibition occurs with the classical-pathway, but not the alternative-pathway, C3 convertase

Activation of the third component of complement (C), C3, is central to the functioning of the C system in inflammation. Cleavage of C3 by the C3 convertases of both the classical and alternative pathways results in the formation of two split products, C3b and C3a. C3a inhibited cleavage of C3 by the classical-pathway C3 convertase. The inhibition varied in a concn-dependent relationship, with a concn of approximately 40 micrograms/ml yielding 50% inhibition. Removal of the carboxy terminal arginine from the C3a did not alter the inhibition. C3a did not inhibit cleavage of C3 by the alternative C pathway C3 convertase, or cleavage of C5 by C5 convertase. The C3-cleaving capacity of EAC142oxy that had been previously incubated with C3a could be recovered completely by washing the cells, indicating that the C3a binding to the EAC42oxy cell must have been reversed without having had an effect on the amount of C2 bound. Ribonuclease, a molecule of similar size and charge to C3a, did not affect C3 cleavage and C3a inhibition was not reduced by providing a surface for non-specific adsorption of the C3a, suggesting that the effect of C3a on C3 cleavage was not mediated by non-specific interaction with cell surfaces. C3a inhibited the C3-cleaving capacity of the fluid-phase enzyme, C42oxy, to the same degree as it inhibited the cell-bound enzyme, EAC42oxy, indicating that the C3a must interact with the C42 complex directly. Inhibition of C3 cleavage by C3a is the first demonstration of product inhibition of a complement enzyme. It may provide another control of C3 activation.     

Immiscible Poly(L‐lactide)/Poly(ε‐caprolactone) Blends: Influence of the Addition of a Poly(L‐lactide)‐Poly(oxyethylene) Block Copolymer on Thermal Behavior and Morphology

Summary: A binary blend of poly (L ‐lactide) (PLLA) and poly(ε‐caprolactone) (PCL) of composition 70:30 by weight was prepared using a twin screw miniextruder and investigated by differential scanning calorimetry (DSC), optical microscopy and scanning electron microscopy (SEM). Ternary 70:30:2 blends were also obtained by adding either a diblock copolymer of PLLA and poly(oxyethylene) (PEO) or a triblock PLLA‐PCL‐PLLA copolymer as a third component. Optical microscopy revealed that the domain size of dispersed PCL domains is reduced by one order of magnitude in the presence of both copolymers. SEM confirmed the strong reduction in particle size upon the addition of the copolymers, with an indication of an enhanced emulsifying effect in the case of the PLLA‐PEO copolymer. These results are analyzed on the basis of solubility parameters of the blend components.

Optical micrograph of M3EG2 blend melt quenched at 125 °C.     

Sca‐1 expression defines developmental stages of mouse pDCs that show functional heterogeneity in the endosomal but not lysosomal TLR9 response

Plasmacytoid dendritic cells (pDCs) play an important role in innate and adaptive immunity and were shown to be identical to previously described natural interferon (IFN)‐α‐producing cells. Here, we describe two functionally distinct pDC subpopulations that are characterized by the differential expression of stem cell antigen‐1 (Sca‐1; Ly‐6A/E). Sca‐1^? pDCs are mainly found in the BM, appear first during development, show a higher proliferative activity, and represent the more precursor phenotype. Sca‐1⁺ pDCs are mostly located in secondary lymphoid organs and represent a later developmental stage. Sca‐1^? pDCs give rise to an Sca‐1⁺ subset upon activation or in response to endogenous type I IFN. Interestingly, in contrast to Sca‐1^? pDCs, Sca‐1⁺ pDCs are defective in IFN‐α production upon endosomal TLR9 stimulation, whereas lysosomal signaling via TLR9 is functional in both subsets. Gene expression analysis revealed that osteopontin is strongly upregulated in Sca‐1^? pDCs. These data provide evidence for the molecular basis of the observed functional heterogeneity, as the intracellular isoform of osteopontin couples TLR9 signaling to IFN‐α expression. Taken together, our results indicate that Sca‐1^? pDCs are an early developmental stage of pDCs with distinct innate functions representing the true murine natural IFN‐α‐producing cells.