BACKGROUND: The maximal number of live births (k) per donor was usually determined by cultural and social perspective. It was rarely decided on the basis of scientific evidence or discussed from mathematical or probabilistic viewpoint. METHODS AND RESULTS: To recommend a value for k, we propose three criteria to evaluate its impact on consanguinity and disease incidence due to artificial insemination by donor (AID). The first approach considers the optimization of k under the criterion of fixed tolerable number of consanguineous mating due to AID. The second approach optimizes k under fixed allowable average coefficient of inbreeding. This approach is particularly helpful when assessing the impact on the public, is of interest. The third criterion considers specific inheritance diseases. This approach is useful when evaluating the individual's risk of genetic diseases. When different diseases are considered, this criterion can be easily adopted. All these derivations are based on the assumption of shortage of gamete donors due to great demand and insufficient supply. CONCLUSIONS: Our results indicate that strong degree of assortative mating, small population size and insufficient supply in gamete donors will lead to greater risk of consanguinity. Recommendations under other settings are also tabulated for reference. A web site for calculating the limit for live births per donor is available. 相似文献
The use of focused ultrasound thermal ablation to treat hepatocarcinoma and other liver tumors produces promising clinical results. However, one of the major drawbacks is the high absorption of ultrasonic energy by the rib, making partial rib removal necessary in many cases. This study numerically investigated the feasibility of using a spherical ultrasound phased array for transrib liver-tumor thermal ablation. An independently array-element activitation scheme, which switches off the transducer elements obstructed by the ribs based on feedback anatomical medical imaging, was proposed to reduce the rib-overheating problem. The numerical results showed that the proposed treatment planning strategy can effectively reduce the specific energy absorbed by the rib while maintaining the energy at the target position, which both reduces the rib-overheating problem and increases the possibility of treating a target lesion under an intact rib. The analysis also demonstrated that the target position and the ultrasound frequency play key roles in the treatment. Patients with diverse characteristics were also tested to show the generality of the proposed strategy. The proposed treatment planning strategy also provides useful information for evaluating the treatment effectiveness prior to clinically performing transrib ultrasound liver-tumor thermal ablation. 相似文献
An influenza B outbreak occurred in Taiwan in 2004 and 2005, during which both Victoria (Vic) and Yamagata (Ya) lineages cocirculated. This study examined 36 influenza B viral genomes isolated during the outbreak to reveal their reassortment patterns. According to the isolate groupings in phylogenetic analysis, we were able to categorize those 36 isolates as being of either the Victoria or Yamagata lineage for all eight influenza B virus genomic segments, except for the NS gene, in which clades A and B existed. Based on these groupings, three genome patterns clearly emerged, namely, pattern I (Vic+Vic+Ya+Vic+Ya+Ya+Ya+A, from segments 1 to 8), pattern II (Ya+Ya+Ya+Ya+Ya+Ya+Ya+B), and pattern III (Ya+Ya+Ya+Ya+Ya+Ya+Ya+A). According to the timeline of those isolates under investigation, it appears that pattern I and II viruses could have generated pattern III via reassortment of the NS gene. On the other hand, a genomewide comparison of all six pattern III Taiwanese viruses with 37 international influenza B viral genomes showed that two international strains, B/Oslo/71/04 and B/England/23/04, were consistently clustered with the pattern III viruses isolated in Taiwan in 2004 and 2005, suggesting that Taiwanese pattern III viruses might also have been imported due to their matching genomic composition. 相似文献
This study aimed to examine the relative contribution of genes and environment to psychometrically measured schizotypy and
the causes for the covariation between different dimensions of schizotypy in a total of 330 pairs of twins and 36 same-sex
sib-pairs aged 12–16 and systematically recruited from junior high schools in Taipei. Twins’ zygosity was determined by a
combination of DNA typing and physical similarity. Schizotypy was measured using the Perceptual Aberration Scale (PAS) as
well as the Schizotypal Personality Questionnaire (SPQ) and its three factors (Cognitive-perceptual Dysfunction, Disorganization,
and Interpersonal Dysfunction). Univariate analyses of structural equation modeling using Mx program showed that scores on
these schizotypal measures were substantially heritable (h2 ranging from 41 to 49%), with some genetic effects being non-additive. Multivariate analyses revealed common genetic factors
linking between various traits of schizotypy, with bivariate heritability ranging from 50 to 65%. The proportion of the genetic
contributions not shared with the other measures of schizotypy ranged from 24% for the Disorganization to 49% for the PAS
scores. We concluded that there exist both common and specific genetic factors between the various dimensions of schizotypy,
and at least half of their correlations were genetic in nature.
Edited by Peter McGuffin 相似文献
In emission tomography, anatomical side information, in the form of organ and lesion boundaries, derived from intra-patient coregistered CT or MR scans can be incorporated into the reconstruction. Our interest is in exploring the efficacy of such side information for lesion detectability. To assess detectability we used the SNR of a channelized Hotelling observer and a signal-known exactly/background-known exactly detection task. In simulation studies, we incorporated anatomical side information into a SPECT MAP (maximum a posteriori) reconstruction by smoothing within but not across organ or lesion boundaries. A non-anatomical prior was applied by uniform smoothing across the entire image. We investigated whether the use of anatomical priors with organ boundaries alone or with perfect lesion boundaries alone would change lesion detectability relative to the case of a prior with no anatomical information. Furthermore, we investigated whether any such detectability changes for the organ-boundary case would be a function of the distance of the lesion to the organ boundary. We also investigated whether any detectability changes for the lesion-boundary case would be a function of the degree of proximity, i.e. a difference in the radius of the true functional lesion and the radius of the anatomical lesion boundary. Our results showed almost no detectability difference with versus without organ boundaries at any lesion-to-organ boundary distance. Our results also showed no difference in lesion detectability with and without lesion boundaries, and no variation of lesion detectability with degree of proximity. 相似文献
Background: Homeless youth in the United States have high rates of substance use. Existing research has identified social network composition and street-associated stressors as contributing factors. Incarceration is a highly prevalent stressor for homeless youth. Its effect on youth’s social network composition and substance use, however, has been neglected.
Aims: This study investigated the direct and indirect associations between incarceration history and substance use (through social networks) among homeless youth in Los Angeles, California.
Methods: A sample of 1047 homeless youths were recruited between 2011 and 2013. Computerized self-administrated surveys and social network interviews were conducted to collect youth’s sociodemographic characteristics, incarceration history, social network composition, and substance use. Bootstrapping was used to identify the direct and indirect associations between youth’s incarceration history and substance use.
Results: Incarceration history was positively associated with youth’s cannabis, methamphetamine, and injection drug use. The percentage of cannabis-using peers partially mediated the associations between incarceration history and youth’s cannabis, cocaine, and heroin use. The percentage of methamphetamine-using peers partially mediated the associations between incarceration history and youth's methamphetamine, cocaine, and injection drug use. The percentage of heroin-using peers partially mediated the association between incarceration history and youth’s heroin use. Moreover, the percentage of peers who inject drugs partially mediated the associations between incarceration history and youth’s methamphetamine, heroin, and injection drug use.
Discussion: Incarceration history should be taken to a more central place in future research and practice with homeless youth in the United States. 相似文献
This study aimed to elucidate the modulation by nitric oxide (NO) of the apoptosis of macrophages and osteoblasts, the essential cellular components in the development of periapical lesions. Lipopolysaccharide (LPS) induced prominent nitrite synthesis in J774 mouse macrophage cell lines. Exposure to LPS induced obvious apoptosis in J774 cells, whereas transient transfection with murine inducible nitric oxide synthase (iNOS), small interfering RNA (siRNA) diminished this effect. Tumor necrosis factor-alpha (TNF-alpha) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) (a NO donor) triggered apoptosis in UMR-106 rat osteoblastic cell lines and a synergistic effect was noted when TNF-alpha and SNAP were added to the medium together. Administration of siRNAs for c-Fos and c-Jun: components of activator protein-1 (AP-1) and transforming growth factor-beta1 attenuated the combined effect markedly. Terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) stain in a rat model of induced periapical lesion showed positive apoptotic signals in macrophages and osteoblasts. Administration of N(G)-monomethyl-l-arginine markedly diminished the extent of bone loss and the amounts of apoptotic macrophages and osteoblasts. In conclusion, NO mediates LPS-stimulated apoptosis of macrophages. It also induces osteoblast apoptosis and augments the pro-apoptotic effect of cytokines. Inhibition of NO synthesis in vivo attenuates apoptosis and the size of periapical lesions. Taken together, these results suggest that NO may promote the progression of periapical lesion by inducing the apoptosis of macrophages and osteoblasts. 相似文献
For over a decade, symptom distress has been a key concept in several studies of cancer. However, the definition of symptom distress is still unclear, and there are few measures targeting symptom distress, in general, and specific cancers, in particular. Prostate cancer is the sixth most common cancer worldwide and the second leading cause of death in American men. Many men with clinically localized prostate cancer may experience unique and multidimensional symptoms that occur from diagnosis through treatment, and thereafter. These symptoms associated with the disease and its treatments are in the form of physical and psychological sequelae such as urinary and bowel problems and sexual dysfunction. The purposes of this article are to (1) systematically review literature on symptoms and symptom distress in localized prostate cancer and (2) synthesize evidence of symptom distress applications and measurement in this group. A comprehensive, systematic review was conducted to identify original, data-based studies of symptoms and symptom distress in localized prostate cancer. Clarification of symptom distress and more comprehensive information about symptoms and symptom distress will provide nurses with a better foundation for developing self-management interventions aimed at ameliorating symptom distress and, ultimately, enhancing the quality of life of patients with localized prostate cancer. 相似文献
Gorham–Stout disease (GSD) and generalized lymphatic anomaly (GLA) are subtypes of complex lymphatic malformations (CLMs) with osseous involvement that cause significant complications, including pain and pathologic fractures. As with other vascular anomalies, somatic mosaic mutations in oncogenes are often present, and the mTOR inhibitor sirolimus alleviates symptoms in some, but not all, patients. We describe two patients, one with GSD and one with GLA, found to have EML4::ALK fusions. This report of a targetable, oncogenic fusion in vascular malformations expands our understanding of the genetic basis for CLMs and suggests additional targeted therapies could be effective. 相似文献