The Relationship Between Observers' Self-Attractiveness and Preference for Physical Dimorphism: A Meta-Analysis

Background: Many studies have reported an association between observers' self-attractiveness and their preference for sexual dimorphism across different physical domains, including the face, voice, and body. However, the results of these studies are inconsistent. Here, a meta-analysis was conducted to estimate the association between observers' own attractiveness and their dimorphic preference.Methods: Major electronic databases including PsycINFO, Web of Science, PubMed, ProQuest, and Google Scholar were searched during April 2017 (the first time) and April 2018 (the second time). The effect size computation and moderating effect analyses were conducted separately for masculine and feminine preferences.Results: We identified 5,359 references, of which we included 25 studies (x = 55, x = number of the effect size) with 6,853 participants in the meta-analysis. Across these studies, the correlation between observers' own attractiveness and their sexual dimorphic preference was 0.095 (x = 55) and that for preference for masculinity (x = 39) and femininity (x = 16) were 0.102 and 0.076, respectively. The results of the funnel plot, Egger's regression method, and fail-safe number suggested that there was no obvious publication bias. The relationship depended on the relationship context (short or long-term), opposite or same sex (the gender of the observer and host), measures of observers' self-attractiveness (subject or objective), and preference task (e.g., attractiveness rating, forced-choice, and face sequence test). Furthermore, for female participants, using a hormonal contraceptive also influenced their masculinity preference. The effect size for the preference for a masculine body and voice was larger than that for facial masculinity.Conclusion: We found a small but significant correlation between self-attractiveness and physical dimorphic preference, the relationship was moderated by the relationship context, same/opposite-sex, and contraceptive using. These three moderating effects represented the observer's trade-off on good genes, good provider and good father (3Gs) consistent with the life history strategies. Besides, measurement of observers' attractiveness, type of preference task and stimuli may also involve the relationship

Beneficial effects of trypsin inhibitors derived from a spider venom peptide in L-arginine-induced severe acute pancreatitis in mice.

HWTI is a 55-residue protein isolated from the venom of the spider Ornithoctonus huwena. It is a potent trypsin inhibitor and a moderate voltage-gated potassium channel blocker. Here, we designed and expressed two HWTI mutants, HWTI-mut1 and HWTI-mut2, in which the potassium channel inhibitory activity was reduced while the trypsin inhibitory activity of the wild type form (approximately 5 EPU/mg) was retained. Animal studies showed that these mutants were less toxic than HWTI. The effects of HWTI and HWTI-mut1 were examined in a mouse model of acute pancreatitis induced by intraperitoneal injection of a large dose of L-arginine (4 mg/kg, twice). Serum amylase and serum lipase activities were assessed, and pathological sections of the pancreas were examined. Treatment with HWTI and HWTI-mut1 significantly reduced serum amylase and lipase levels in a dose dependent manner. Compared with the control group, at 4 mg/kg, HWTI significantly reduced serum amylase level by 47% and serum lipase level by 73%, while HWTI-mut1 significantly reduced serum amylase level by 59% and serum lipase level by 72%. Moreover, HWTI and HWTI-mut1 effectively protected the pancreas from acinar cell damage and inflammatory cell infiltration. The trypsin inhibitory potency and lower neurotoxicity of HWTI-mut1 suggest that it could potentially be developed as a drug for the treatment of acute pancreatitis with few side effects

Effect of HWTI and the two mutants on potassium channel activity in rat DRG cells.

<p>Potassium currents were recorded by whole-cell patch-clamp with rapidly dissociated DRG neurons. (A) Currents were recorded before and after the application of 10 µM HWTI. (B) Currents measured in the presence of HWTI were converted into percent of control currents and plotted versus the log[HWTI], with an IC₅₀ of 3.92 µM. (C) Currents were recorded before and after the application of 10 µM HWTI-mut1. (D) Currents measured in the presence of HWTI-mut1 were converted into percent of control currents and plotted versus the log[HWTI-mut1]. (E) Currents were recorded before and after the application of 10 µM HWTI-mut2. (F) Currents measured in the presence of HWTI-mut2 were converted into percent of control currents and plotted versus the log[HWTI-mut2].</p

Protective effects of HWTI and HWTI-mut1 against damage to the pancreas.

<p>Pancreatic samples were obtained 72 hours after the induction of SAP. Formalin-fixed, paraffin-embedded sections of the pancreas were stained with hematoxylin and eosin. (A) Photomicrograph of the normal pancreas. (B) Mice were injected with saline after the induction of SAP. Sections show extensive acinar cell damage, edema and evident leukocyte infiltration. (C) Treatment with HWTI reduced the symptoms of acinar cell damage, leukocyte infiltration and edema. Normal acinar cell architecture was seen in the 4 mg/kg group. (D) Injection of HWTI-mut1 had a greater protective effect on the pancreas than HWTI. The 2 mg/kg and 4 mg/kg groups showed no significant damage to acinar cells. Magnification: 200×.</p

Purification of HWTI and the two mutants.

<p>Fractions collected from the CM-Sepharose column were applied to a RP-HPLC column equilibrated with 0.1% trifluoroacetic acid for further purification at a flow rate of 2 mL/min (buffer B, 0.1% trifluoroacetic acid in acetonitrile) with an increase from 20% to 30% over 13 minutes. The molecular mass of the purified protein was measured by MALDI-TOF mass spectrometry. The retention time of HWTI was 19.23 min. (A), and the measured MW was 6,173.25 (B). For HWTI-mut1, the retention time was 21 min (C), and the measured MW was 6,089.52 (D). The retention time of HWTI-mut2 was 19.5 min (E), and the measured MW was 6,138.12 (F).</p

Effect of HWTI and HWTI-mut1 on the reduction of serum amylase and lipase levels.

<p>Severe acute pancreatitis in mice was induced by injecting 4 g/kg L-arginine (8%) twice with a 1 hour interval. HWTI and HWTI-mut1 were administered intraperitoneally 8, 24, and 48 hours after the first injection of L-arginine. Mice were sacrificed at 72 hours and serum was collected for the measurement of amylase and lipase levels. (A) HWTI and HWTI-mut1 significantly reduced serum amylase levels at a dose of 1 mg/kg. At the maximal dose (4 mg/kg), the amylase level was nearly half of that of the control group. HWTI-mut1 was more effective at reducing amylase levels in the 4 mg/kg group than HWTI. (B) HWTI and HWTI-mut1 significantly reduced serum lipase levels at a dose of 2 mg/kg. In the 4 mg/kg group, serum lipase level was nearly 1/3 of that of the control group. Data are shown in IU/L and expressed as mean+SE (n = 8–12). * denotes p<0.05 compared with the control group; ** denotes p<0.01 compared with the control group; ^# denotes p<0.05 between lined groups.</p

Structure and sequence comparison of HWTI and BPTI.

<p>(A) Amino acid sequences of HWTI and BPTI and the two mutants. The disulfide bonds are indicated above the sequences. Gray shading indicates identical residues between HWTI and BPTI. The potassium channel inhibition-related residues in HWTI are labeled in green, while the corresponding residues in BPTI are labeled in red. In the two BPTI mutants, the mutated residues are indicated in red. (B) 3D structures of HWTI (PDB code, 2JOT) and BPTI (PDB code, 1LD5). The residues corresponding to the inhibitory activity against trypsin and potassium channels are indicated.</p