1,065 research outputs found

    Rapid aneuploidy testing (knowing less) versus traditional karyotyping (knowing more) for advanced maternal age: What would be missed, who should decide?

    Get PDF
    Objectives The application of rapid aneuploidy testing as a stand-alone approach in prenatal diagnosis is much debated. The major criticism of this targeted approach is that it will not detect other chromosomal abnormalities that will be picked up by traditional karyotyping. This study aimed to study the nature of such chromosomal abnormalities and whether parents would choose to terminate affected pregnancies. Design Retrospective study on a cytogenetic database. Setting Eight public hospitals in Hong Kong. Participants The karyotype results of 19 517 amniotic fluid cultures performed for advanced maternal age (≥35 years) from 1997 to 2002 were classified according to whether they were detectable by rapid aneuploidy testing. The outcomes of pregnancies with abnormal karyotypes were reviewed from patient records. Results In all, 333 (1.7%) amniotic fluid cultures yielded abnormal karyotypes; 175 (52.6%) of these were detected by rapid aneuploidy testing, and included trisomy 21 (n=94, 28.2%), trisomy 18 or 13 (n=21, 6.3%), and sex chromosome abnormalities (n=60, 18.0%). The other 158 (47.4%) chromosomal abnormalities were not detectable by rapid aneuploidy testing, of which 63 (18.9%) were regarded to be of potential clinical significance and 95 (28.5%) of no clinical significance. Pregnancy outcomes in 327/333 (98.2%) of these patients were retrieved. In total, 143 (42.9%) of these pregnancies were terminated: 93/94 (98.9%) for trisomy 21, 20/21 (95.2%) for trisomy 18 or 13, 19/60 (31.7%) for sex chromosome abnormalities, and 11/63 (17.5%) for other chromosomal abnormalities with potential clinical significance. There were no terminations in the 95 pregnancies in which karyotyping results were regarded to be of no clinical significance. Conclusions 'Knowing less' by the rapid aneuploidy stand-alone testing could miss about half of all chromosomal abnormalities detectable by amniocentesis performed for advanced maternal age. Findings from two fifths of the latter were of potential clinical significance, and the parents chose to terminate one out of six of the corresponding pregnancies. If both techniques are available, parents could have enhanced autonomy to choose.published_or_final_versio

    Lobular breast cancers lack the inverse relationship between ER/PR status and cell growth rate characteristic of ductal cancers in two independent patient cohorts: implications for tumor biology and adjuvant therapy

    Get PDF
    BACKGROUND: Although invasive lobular carcinoma (ILC) of the breast differs from invasive ductal carcinoma (IDC) in numerous respects - including its genetics, clinical phenotype, metastatic pattern, and chemosensitivity - most experts continue to manage ILC and IDC identically in the adjuvant setting. Here we address this discrepancy by comparing early-stage ILC and IDC in two breast cancer patient cohorts of differing nationality and ethnicity. METHODS: The clinicopathologic features of 2029 consecutive breast cancer patients diagnosed in Hong Kong (HK) and Australia (AUS) were compared. Interrelationships between tumor histology and other clinicopathologic variables, including ER/PR and Ki67, were analysed. RESULTS: Two hundred thirty-nine patients were identified with ILC (11.8%) and 1790 patients with IDC. AUS patients were older (p 0.7). Moreover, whereas IDC tumors exhibited a strongly negative relationship between ER/PR and Ki67 status (p 0.6). CONCLUSION: These data imply that the primary adhesion defect in ILC underlies a secondary stromal-epithelial disconnect between hormonal signaling and tumor growth, suggesting in turn that this peritumoral feedback defect could reduce both the antimetastatic (adjuvant) and tumorilytic (palliative) efficacy of cytotoxic therapies for such tumors. Hence, we caution against assuming similar adjuvant chemotherapeutic survival benefits for ILC and IDC tumors with similar ER and Ki67, whether based on immunohistochemical or gene expression assays.published_or_final_versio

    Attention-Deficit/Hyperactivity Disorder medication consumption in 64 countries and regions from 2015 to 2019: a longitudinal study

    Get PDF
    Background: Timely recognition and appropriate treatment of attention-deficit/hyperactivity disorder (ADHD) are essential to enhance long-term outcomes of individuals with ADHD. This study aimed to evaluate the multinational trends and patterns of ADHD medication consumption. Methods: In this longitudinal trend study, we used pharmaceutical sales data of ADHD medication from the IQVIA-Multinational Integrated Data Analysis System between 2015 and 2019, covering 64 countries across the world. Consumption rates of ADHD medication were expressed as defined daily dose per 1000 child and adolescent inhabitants (aged 5–19) per day (DDD/TID). Linear mixed models were used to estimate the multinational, regional, and income level trend changes. Findings: The results showed that multinational ADHD medication consumption increased by +9.72% (95% confidence interval [CI], +6.25%, +13.31%) per year, from 1.19 DDD/TID in 2015 to 1.43 DDD/TID in 2019 across the 64 countries with marked differences between geographical locations. When stratified by countries’ income levels, increases in ADHD medication consumption were observed in high-income countries but not in middle-income countries. In 2019, the pooled consumption rates of ADHD medication were 6.39 DDD/TID (95% CI, 4.63, 8.84) in high-income countries, 0.37 DDD/TID (95% CI, 0.23, 0.58) in upper-middle-income countries and 0.02 DDD/TID (95% CI, 0.01, 0.05) in lower-middle-income countries. Interpretation: Current ADHD prevalence estimates and rates of ADHD medication consumption in most middle-income countries are lower than the global epidemiological prevalence. It is therefore imperative to evaluate the potential barriers to diagnosis and treatment in these countries to minimise the risk of negative outcomes from undiagnosed and untreated ADHD. Funding: This project was funded by a grant from the Hong Kong Research Grants Council Collaborative Research Fund (project number C7009-19G)

    A Model for the Prediction of Fiber Elasticity

    Get PDF
    A model is presented that enables the elastic properties of wood fibers to be estimated from the properties of its polymeric constituents, cellulose, hemicellulose, and lignin. The influence of the value of the axial stiffness of the cellulose crystal is demonstrated, its proper value being discussed in comparison with experimental data on fibers. The effects on fiber stiffness of the S2 fibril angle, the fibril angles of other layers, the crystallinity, and layer thicknesses are analyzed. The manner in which the effect of a variation in yield can be simulated by a change in shape factor of the reinforcing cellulose crystals is demonstrated, the cell wall thus being considered to be a discontinuous reinforced composite

    Laparoscopic correction of perforated peptic ulcer: first choice? A review of literature

    Get PDF
    Background Perforated peptic ulcer (PPU), despite antiulcer medication and Helicobacter eradication, is still the most common indication for emergency gastric surgery associated with high morbidity and mortality. Outcome might be improved by performing this procedure laparoscopically, but there is no consensus on whether the benefits of laparoscopic closure of perforated peptic ulcer outweigh the disadvantages such as prolonged surgery time and greater expense. Methods An electronic literature search was done by using PubMed and EMBASE databases. Relevant papers written between January 1989 and May 2009 were selected and scored according to Effective Public Health Practice Project guidelines. Results Data were extracted from 56 papers, as summarized in Tables 1-7. The overall conversion rate for laparoscopic correction of perforated peptic ulcer was 12.4%, with main reason for conversion being the diameter of perforation. Patients presenting with PPU were predominantly men (79%), with an average age of 48 years. Onethird had a history of peptic ulcer disease, and one-fifth took nonsteroidal anti-inflammatory drugs (NSAIDs). Only 7% presented with shock at admission. There seems to be no consensus on the perfect setup for surgery and/or operating technique. In the laparoscopic groups, operating time was significant longer and incidence of recurrent leakage at the repair site was higher. Nonetheless there was significant less postoperative pain, lower morbidity, less mortality, and shorter hospital stay. Conclusion There are good arguments that laparoscopic correction of PPU should be first treatment of choice. A Boey score of 3, age over 70 years, and symptoms persisting longer than 24 h are associated with higher morbidity and mortality and should be considered contraindications for laparoscopic intervention

    “Conjugate Channeling” Effect in Dislocation Core Diffusion: Carbon Transport in Dislocated BCC Iron

    Get PDF
    Dislocation pipe diffusion seems to be a well-established phenomenon. Here we demonstrate an unexpected effect, that the migration of interstitials such as carbon in iron may be accelerated not in the dislocation line direction [symbol], but in a conjugate diffusion direction. This accelerated random walk arises from a simple crystallographic channeling effect. [c] is a function of the Burgers vector b, but not [symbol], thus a dislocation loop possesses the same everywhere. Using molecular dynamics and accelerated dynamics simulations, we further show that such dislocation-core-coupled carbon diffusion in iron has temperature-dependent activation enthalpy like a fragile glass. The 71° mixed dislocation is the only case in which we see straightforward pipe diffusion that does not depend on dislocation mobility.National Science Foundation (U.S.) (Grant No. CMMI-0728069)National Science Foundation (U.S.) (Grant No. DMR-1008104)National Science Foundation (U.S.) (Grant No. DMR-1120901
    corecore