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Positive selection in the egg receptor for abalone sperm lysin   总被引:18,自引:0,他引:18       下载免费PDF全文
The mechanism of speciation is a central problem in evolutionary biology. In free-spawning animals with no complex mating behavior, prezygotic reproductive isolation (speciation) could result from the rapid divergence of genes coding for sperm and egg proteins that bind each other during fertilization. In abalone, sperm lysin evolves rapidly by positive Darwinian selection. The egg vitelline envelope receptor for lysin had previously been shown to evolve neutrally and be subjected to concerted evolution. Several mathematical simulations predict that both male and female reproductive proteins should evolve rapidly by positive selection. Here we report that the sequence diversity of the amino-terminal end of the egg vitelline envelope receptor for lysin has been promoted by positive Darwinian selection. These data provide molecular support for theoretical models showing that the two sexes are locked in a "coevolutionary chase" that could be driven by processes such as sexual selection, sexual conflict, or microbial attack (pathogen avoidance). The result of this continuous coevolution of the gamete recognition system could be the splitting of one population into two that are reproductively isolated (speciation).  相似文献   
94.

Objectives

We analyzed the characteristics of carcinomas that could influence margin status and the existence of residual tumor in reexcisons.

Material and methods

We retrospectively studied the characteristics of 133 breast carcinomas diagnosed by mammographic wire-guided biopsy.

Results

In 37.59% biopsy was the only surgery in the breast. A total of 31.6% of margins were clear (more than 3 mm.), 20.3% were close (equal to or less than 3 mm) and 48.1% showed tumoral involvement. The mean tumor size of carcinomas with clear margins was statistically smaller than those with involved margins. Histological grade was related to margin status in ductal carcinomas in situ (DCIS) and to higher positive reexcision rates (grades II and III) in infiltrating ductal carcinomas (IDC). The overall residual tumor rate was 50%, but this percentage was higher in reexcisions of infiltrating lobular carcinomas (ILC) (85.71%), DCIS (70.53%), and in carcinomas with axillary lymph node involvement. A second reexcision was required in 13.79% of DCIS.

Conclusions

Reexcision is recommended in patients with ILC, DCIS and IDC (especially histological grades II and III in both cases) in which margins of more than 3 mm have not been achieved, regardless other characteristics. Clear margins are sometimes difficult to obtain in DCIS.  相似文献   
95.
The procedure generally used to remove bacterial biofilm adhering to the surface of titanium on dental implants is implantoplasty. This treatment is based on the machining of the titanium surface to remove bacterial plaque. In this study, we used 60 grade 4 titanium implants and performed the implantoplasty protocol. Using X-ray diffraction, we determined the stresses accumulated in each of the as-received, machined and debris implants. The resistance to corrosion in open circuit and potentiodynamically in physiological medium has been determined, and the corrosion potentials and intensities have been determined. Tests have been carried out to determine ion release by ICP-MS at different immersion times. The results show that the corrosion resistance and the release of titanium ions into the medium are related to the accumulated energy or the degree of deformation. The titanium debris exhibit compressive residual stresses of −202 MPa, the implant treated with implantoplasty −120 MPa, and as-received −77 MPa, with their corrosion behavior resulting in corrosion rates of 0.501, 0.77, and 0.444 mm/year, respectively. Debris is the material with the worst corrosion resistance and the one that releases the most titanium ions to the physiological medium (15.3 ppb after 21 days vs. 7 ppb for as-received samples). Pitting has been observed on the surface of the debris released into the physiological environment. This behavior should be taken into account by clinicians for the good long-term behavior of implants with implantoplasty.  相似文献   
96.
Compare community integration of people with stroke or traumatic brain injury (TBI) living in the community before and during the coronavirus severe acute respiratory syndrome coronavirus 2 disease (COVID-19) when stratifying by injury: participants with stroke (G1) and with TBI (G2); by functional independence in activities of daily living: independent (G3) and dependent (G4); by age: participants younger than 54 (G5) and older than 54 (G6); and by gender: female (G7) and male (G8) participants.Prospective observational cohort studyIn-person follow-up visits (before COVID-19 outbreak) to a rehabilitation hospital in Spain and on-line during COVID-19.Community dwelling adults (≥18 years) with chronic stroke or TBI.Community integration questionnaire (CIQ) the total-CIQ as well as the subscale domains (ie, home-CIQ, social-CIQ, productivity CIQ) were compared before and during COVID-19 using the Wilcoxon ranked test or paired t test when appropriate reporting Cohen effect sizes (d). The functional independence measure was used to assess functional independence in activities of daily living.Two hundred four participants, 51.4% with stroke and 48.6% with TBI assessed on-line between June 2020 and April 2021 were compared to their own in-person assessments performed before COVID-19.When analyzing total-CIQ, G1 (d = −0.231), G2 (d = −0.240), G3 (d = −0.285), G5 (d = −0.276), G6 (d = −0.199), G7 (d = −0.245), and G8 (d = −0.210) significantly decreased their scores during COVID-19, meanwhile G4 was the only group with no significant differences before and during COVID-19.In productivity-CIQ, G1 (d = −0.197), G4 (d = −0.215), G6 (d = −0.300), and G8 (d = −0.210) significantly increased their scores, meanwhile no significant differences were observed in G2, G3, G5, and G7.In social-CIQ, all groups significantly decreased their scores: G1 (d = −0.348), G2 (d = −0.372), G3 (d = −0.437), G4 (d = −0.253), G5 (d = −0.394), G6 (d = −0.319), G7 (d = −0.355), and G8 (d = −0.365).In home-CIQ only G6 (d = −0.229) significantly decreased, no significant differences were observed in any of the other groups.The largest effect sizes were observed in total-CIQ for G3, in productivity-CIQ for G6, in social-CIQ for G3 and in home-CIQ for G6 (medium effect sizes).Stratifying participants by injury, functionality, age or gender allowed identifying specific CIQ subtotals where remote support may be provided addressing them.  相似文献   
97.
Genome complexity has been associated with poor outcome in patients with chronic lymphocytic leukemia (CLL). Previous cooperative studies established five abnormalities as the cut-off that best predicts an adverse evolution by chromosome banding analysis (CBA) and genomic microarrays (GM). However, data comparing risk stratification by both methods are scarce. Herein, we assessed a cohort of 340 untreated CLL patients highly enriched in cases with complex karyotype (CK) (46.5%) with parallel CBA and GM studies. Abnormalities found by both techniques were compared. Prognostic stratification in three risk groups based on genomic complexity (0-2, 3-4 and ≥5 abnormalities) was also analyzed. No significant differences in the percentage of patients in each group were detected, but only a moderate agreement was observed between methods when focusing on individual cases (κ=0.507; P<0.001). Discordant classification was obtained in 100 patients (29.4%), including 3% classified in opposite risk groups. Most discrepancies were technique-dependent and no greater correlation in the number of abnormalities was achieved when different filtering strategies were applied for GM. Nonetheless, both methods showed a similar concordance index for prediction of time to first treatment (TTFT) (CBA: 0.67 vs. GM: 0.65) and overall survival (CBA: 0.55 vs. GM: 0.57). High complexity maintained its significance in the multivariate analysis for TTFT including TP53 and IGHV status when defined by CBA (hazard ratio [HR] 3.23; P<0.001) and GM (HR 2.74; P<0.001). Our findings suggest that both methods are useful but not equivalent for risk stratification of CLL patients. Validation studies are needed to establish the prognostic value of genome complexity based on GM data in future prospective studies.  相似文献   
98.
In advanced breast cancer, biomarker identification and patient selection using a metastatic tumor biopsy is becoming more necessary. However, the biology of metastasis according to the organ site is largely unknown. Here, we evaluated the expression of 771 genes in 184 metastatic samples across 11 organs, including liver, lung, brain, and bone, and made the following observations. First, all PAM50 molecular intrinsic subtypes were represented across organs and within immunohistochemistry‐based groups. Second, HER2‐low disease was identified across all organ sites, including bone, and HER2 expression significantly correlated with ERBB2 expression. Third, the majority of expression variation was explained by intrinsic subtype and not organ of metastasis. Fourth, subtypes and individual subtype‐related genes/signatures were significantly associated with overall survival. Fifth, we identified 74 genes whose expression was organ‐specific and subtype‐independent. Finally, immune profiles were found more expressed in lung compared to brain or liver metastasis. Our results suggest that relevant tumor biology can be captured in metastatic tissues across a variety of organ sites; however, unique biological features according to organ site were also identified and future studies should explore their implications in diagnostic and therapeutic interventions.  相似文献   
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Chlorpromazine is known to produce both systemic phototoxic and photoallergic reactions. However, it may also cause photoallergic contact dermatitis and, albeit exceptionally, allergic contact dermatitis (ACD). We present a series of photoallergic contact dermatitis and ACD to chlorpromazine diagnosed at a tertiary centre cutaneous allergy unit between 1980 and 2019.  相似文献   
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