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排序方式: 共有514条查询结果,搜索用时 15 毫秒
91.
Transfusion of patients with sickle cell disease (SCD) has been a challenge in clinical transfusion medicine, especially when the required donor RBCs must be U- and negative for high-prevalence Rh phenotypes (hr(B), hr(S)). It is now possible to genotype donors to identify or confirm Uvar and U- phenotypes, as well as Rh hr(B)- and hrS- phenotypes, and to characterize the different RH backgrounds found in these donors. In a preliminary study of donors registered in the American Rare Donor Program, twelve different RH backgrounds were identified in eighteen hr(B)- or hr(S)- donors. These results, summarized in the current report, confirm the heterogeneous nature of these phenotypes and are relevant for selection of donor units for patients with antibodies to high-prevalence Rh antigens. Not all phenotypically similar units will be compatible, and matching the Rh genotype of the donor to the patient is important to prevent further Rh sensitization. Most donors referred were hr(B)- and carry at least one hybrid RHD-CE(3-7)-D gene that encodes a variant C antigen linked to RHCE*ceS that encodes the VS+V- phenotype. Surprisingly, the majority of donors were heterozygous, some even carrying conventional alleles, suggesting that the loss of expression of the hr(B) epitopes on RBCs is a dominant phenotype. Although antigen-matching of patients with SCD with donors for C, E, and K antigens has decreased the incidence of alloimmunization, some patients still become immunized to Rh antigens, indicating the units were not truly matched. RH genotyping can identify those patients with SCD who carry RH alleles that encode altered C, e, or D who are at risk for production of "apparent auto" and alloantibodies to Rh antigens. RH genotyping of alloimmunized patients with SCD, partnered with genotyping of donors, can identify compatible units that would also eliminate the risk of further Rh alloimmunization. 相似文献
92.
Horn T Castilho L Moulds JM Billingsley K Vege S Johnson N Westhoff CM 《Transfusion》2012,52(5):1092-1096
BACKGROUND: The Jk(a?b?) null phenotype is not common but is more prevalent in Polynesian and Asian persons and appears to be rare in blacks. We determined the molecular basis for Jk(a?b?) in an African American family. DNA testing of samples from random African American, Caucasian, and Brazilian blacks was done to estimate the allele frequency. STUDY DESIGN AND METHODS: Standard methods were used for red blood cell (RBC) typing. DNA was isolated from white blood cells, and polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) and amplification and sequencing of the coding regions of JK were performed by routine molecular methods. A MaeIII PCR‐RFLP assay was designed to target the nucleotide (nt) change. RESULTS: RBCs from the proband typed as Jk(a?b?) and DNA testing indicated JK*A/JK*A. JK sequencing found that the sample was homozygous for nt561C>A change, predicted to encode a premature stop in the protein (187Stop). The altered allele was present in the heterozygous state in three of six siblings. Testing of 500 African American and 100 Caucasian donors from the same region and 500 African American donors from the southern United States found no additional examples. Screening of 1174 Brazilian blacks revealed seven examples: one homozygote and six heterozygotes. CONCLUSIONS: JK*A (561C>A) is associated with a Kidd‐null phenotype in this African American family. The allele was present in approximately one in 168 Brazilian blacks, suggesting that detection of this allele is important to avoid false‐positive prediction of Jk(a) status in this population. 相似文献
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Lauren Stephanie Chernick Rebecca Schnall Melissa S Stockwell Paula M Casta?o Tracy Higgins Carolyn Westhoff John Santelli Peter S Dayan 《Journal of medical Internet research》2016,18(9)
BackgroundOver 15 million adolescents use the emergency department (ED) each year in the United States. Adolescent females who use the ED for medical care have been found to be at high risk for unintended pregnancy. Given that adolescents represent the largest users of text messaging and are receptive to receiving text messages related to their sexual health, the ED visit represents an opportunity for intervention.ObjectiveThe aim of this qualitative study was to explore interest in and preferences for the content, frequency, and timing of an ED-based text message intervention to prevent pregnancy for adolescent females.MethodsWe conducted semistructured, open-ended interviews in one urban ED in the United States with adolescent females aged 14-19 years. Eligible subjects were adolescents who were sexually active in the past 3 months, presented to the ED for a reproductive health complaint, owned a mobile phone, and did not use effective contraception. Using an interview guide, enrollment continued until saturation of key themes. The investigators designed sample text messages using the Health Beliefs Model and participants viewed these on a mobile phone. The team recorded, transcribed, and coded interviews based on thematic analysis using the qualitative analysis software NVivo and Excel.ResultsParticipants (n=14) were predominantly Hispanic (13/14; 93%), insured (13/14; 93%), ED users in the past year (12/14; 86%), and frequent text users (10/14; 71% had sent or received >30 texts per day). All were interested in receiving text messages from the ED about pregnancy prevention, favoring messages that were “brief,” “professional,” and “nonaccusatory.” Respondents favored texts with links to websites, repeated information regarding places to receive “confidential” care, and focused information on contraception options and misconceptions. Preferences for text message frequency varied from daily to monthly, with random hours of delivery to maintain “surprise.” No participant feared that text messages would violate her privacy.ConclusionsAdolescent female patients at high pregnancy risk are interested in ED-based pregnancy prevention provided by texting. Understanding preferences for the content, frequency, and timing of messages can guide in designing future interventions in the ED. 相似文献
95.
Maryam Pourhassan Bjoern Buehring Ulrik Stervbo Sven Rahmann Felix Mlder Sebastian Rütten Ulrike Trampisch Nina Babel Timm Henning Westhoff Rainer Wirth 《Nutrients》2021,13(11)
Osteoporosis and sarcopenia are two chronic conditions, which widely affect older people and share common risk factors. We investigated the prevalence of low bone mineral density (BMD) and sarcopenia, including the overlap of both conditions (osteosarcopenia) in 572 older hospitalized patients (mean age 75.1 ± 10.8 years, 78% women) with known or suspected osteoporosis in this prospective observational multicenter study. Sarcopenia was assessed according to the revised definition of the European Working Group on Sarcopenia in Older People (EWGSOP2). Low BMD was defined according to the World Health Organization (WHO) recommendations as a T-score < −1.0. Osteosarcopenia was diagnosed when both low BMD and sarcopenia were present. Low BMD was prevalent in 76% and the prevalence of sarcopenia was 9%, with 90% of the sarcopenic patients showing the overlap of osteosarcopenia (8% of the entire population). Conversely, only few patients with low BMD demonstrated sarcopenia (11%). Osteosarcopenic patients were older and frailer and had lower BMI, fat, and muscle mass, handgrip strength, and T-score compared to nonosteosarcopenic patients. We conclude that osteosarcopenia is extremely common in sarcopenic subjects. Considering the increased risk of falls in patients with sarcopenia, they should always be evaluated for osteoporosis. 相似文献
96.
Matthias Schneider Lea Vollmer Anna-Laura Potthoff Vidhya M Ravi Bernd O Evert Mohummad A Rahman Shahin Sarowar Jan Kueckelhaus Paulina Will David Zurhorst Kevin Joseph Julian P Maier Nicolas Neidert Paolo dErrico Melanie Meyer-Luehmann Ulrich G Hofmann Andreas Dolf Paolo Salomoni Erdem Güresir Per
Enger Martha Chekenya Torsten Pietsch Patrick Schuss Oliver Schnell Mike-Andrew Westhoff Jürgen Beck Hartmut Vatter Andreas Waha Ulrich Herrlinger Dieter H Heiland 《Neuro-oncology》2021,23(11):1885
97.
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99.
The long-term prognosis of Legg-Calvé-Perthes disease primarily depends on the spherical form of the femoral head and the congruency of the hip joint after healing. Of the many factors influencing the outcome only the range of mobility and containment can be addressed therapeutically. The mobility of the joint is maintained or restored through various conservative measures thus reducing joint deforming forces. If loss of containment becomes evident operative treatment is indicated, preferably in the early fragmentation stage. For biomechanical reasons correction of the acetabulum is preferred. For children less than 8.5 years old greater trochanteric apophyseodesis is warranted to prevent trochanteric overgrowth. The results of containment ameliorating surgery are promising. In older children with severe Legg-Calvé-Perthes disease the results are less promising. 相似文献
100.