Model for assessment of proficiency of human immunodeficiency virus type 1 sequencing-based genotypic antiretroviral assays

Use of sequencing-based genotyping as a diagnostic assay for human immunodeficiency virus (HIV) antiretroviral resistance is increasing. Periodic evaluation of the proficiency of laboratories performing this assay should be established. It is important to identify components of the assay that influence the generation of reliable sequencing data and that should and can be monitored. A model was developed to determine what parameters were reasonable and feasible for assessing the performance of genotyping assays. Ten laboratories using the genotyping platform, HIV-1 Genotyping System (HGS) v. 1 and software versions 1.1 or 2.0, participated in two rounds of testing. For each round, each group was sent a panel consisting of three clinical samples to sequence in real time. Six months later, seven laboratories using the TRUGENE HIV-1 Genotyping Kit participated in a separate round, working with both panels at the same time. Analysis of the data showed that one main indicator of genotyping proficiency was achievement of > or =98% sequence homology of a sample tested to a group consensus sequence for that sample. A second was concordant identification of codons at sites identified with resistance mutations in the sample, although scoring of these criteria is still undetermined from this study. These criteria are applicable to all sequence-based genotyping platforms and have been used as a baseline for assessing the performance of genotyping for the determination of antiretroviral resistance in our ongoing proficiency program.     

Teaching medical students about medical errors and patient safety: evaluation of a required curriculum.

PURPOSE: To assess the effectiveness of a brief curriculum about patient safety and medical errors with third-year medical students. METHOD: From 2000-03, third-year medical students at New York Medical College, Valhalla, New York, were required to participate in a new curriculum on patient safety and medical errors during their family medicine clerkships. Five hundred seventy-two students participated in a four-hour curriculum that included interactive discussion, readings, a videotape session with a standardized patient, and a small-group debriefing facilitated by a family physician. Before and after participating in the curriculum, students were asked to complete questionnaires on self-awareness about patient communication and safety. Curriculum evaluations and follow-up surveys were also distributed. Responses to each statement on the before and after questionnaires were compared using the Wilcoxon signed-rank test for matched data. RESULTS: Five hundred eleven (89%) students reported that the opportunity to present an error to a patient increased their confidence about discussing this issue with patients, and 537 (94%) students reported that they strongly agreed or agreed that the standardized patient and feedback exercise was a useful learning experience. A total of 535 before and after questionnaires were used in the analysis. A comparison of before and after questionnaire data revealed statistically significant increases in the self-reported awareness of students' strengths and weaknesses in communicating medical errors to patients (p 相似文献   

Molecular cloning and characterization of the 78-kilodalton glucose-regulated protein of Trypanosoma cruzi.

The protozoan Trypanosoma cruzi is the etiologic agent of Chagas' disease, an illness responsible for morbidity and death among millions of Latin Americans. Mice also develop this disease when infected with T. cruzi and are a useful model organism for the study of parasite-specific immune responses. To identify immunogenic T. cruzi antigens, serum from an infected mouse was used to isolate clones from a T. cruzi epimastigote cDNA expression library. One of these clones was found to encode the 78-kDa glucose-regulated protein (grp78), the endoplasmic reticular member of the 70-kDa heat shock protein (hsp70) family. Like the mammalian and yeast grp78s, the T. cruzi protein contains an endoplasmic reticular leader peptide and a carboxyl-terminal endoplasmic reticular retention sequence. T. cruzi grp78 is encoded by a tandemly arranged family of three genes located on a chromosome of 1.6 Mb. The effects on grp78 expression of heat shock and tunicamycin treatment, the latter of which specifically stimulates mammalian grp78, were investigated. While the level of the grp78 protein remained constant under all circumstances, grp78 mRNA was unaffected by heat shock but induced fivefold by tunicamycin. Finally, we found that grp78 is the most immunogenic of the T. cruzi heat shock proteins we have characterized, reacting strongly in immunoblots with sera from infected mice.     

The rheumatic patient''s early needs and expectations

During the last few years, studies have revealed that the need for psychosocial support and concrete social services are great in the early stages of the treatment of rheumatic diseases. The ability to keep a job, to do household chores, to participate in leisure activities and to maintain social relations is clearly impaired. Anxiety and depression are not unusual and often associated with weak support from relatives, loneliness and disturbed family relations. Nevertheless, the patients report resilience and determination to cope with the impacts of illness. Crisis intervention, vocational guidance and counselling about problems concerning the disease should be available and offered to the patients. As the patients seem to be unaccustomed to talking about their psychosocial problems, an empathetic and information-seeking attitude on the part of the health care staff is essential.     

Extent, pattern, and correlates of remote memory impairment in Alzheimer's disease and Parkinson's disease

Content and contextual memory for remote public figures and events was assessed with a modified version of the Presidents Test in patients with Alzheimer's disease (AD) or Parkinson's disease (PD). Contributions of executive functioning, semantic memory, and explicit anterograde memory to remote memory abilities were also examined. The AD group had temporally extensive deficits in content and contextual remote memory not accountable for by dementia severity. The PD group did not differ from the control group in remote memory, despite anterograde memory impairment. These results support the position that different component processes characterize remote memory, various mnemonic and nonmnemonic cognitive processes contribute to remote memory performance, and anterograde and remote memory processes are dissociable and differentially disrupted by neurodegenerative disease.     

Qa-1, a nonclassical class I histocompatibility molecule with roles in innate and adaptive immunity

Qa-1, a nonclassical class I histocompatibility molecule expressed in mice, predominantly assembles with a single nonameric peptide, Qdm, derived from the signal sequence of certain class Ia molecules. The Qa-1/Qdm complex is the primary ligand for CD94/NKG2A inhibitory receptors expressed on a major fraction of natural killer (NK) cells. Cells become susceptible to killing by NK cells under conditions where surface expression of the Qa-1/Qdm inhibitory ligand is reduced. The CD94/NKG2 "missing-self" recognition system serves as mechanism for removing cells that have abnormalities in the intracellular machinery required for assembly and expression of class I-peptides complexes, as a consequence of viral infection, for example. Despite its highly focused peptide-binding specificity, Qa-1 also has a capacity to act as an antigen-presentation molecule for CD8+ T cells. It appears that a small subpopulation of these T cells undergoes positive selection by interaction with Qa-1 in the thymus, and they maintain their specificity for Qa-1 after maturation. The role of these unusual T cells in adaptive immune responses remains to be defined.     

Graft-versus-host disease as adoptive immunotherapy in patients with advanced hematologic neoplasms

The occurrence of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation for leukemia is thought to decrease the probability of recurrence. To study this effect (called adoptive immunotherapy) we modified the prophylaxis of GVHD in patients with advanced hematologic neoplasms (mostly leukemia) who received bone marrow transplants. Patients under 30 years of age were randomly assigned to one of three regimens of post-transplantation immunosuppression: Group I (n = 44) received a standard course of methotrexate for 102 days after transplantation, Group II (n = 40) received an abbreviated (11-day) course of methotrexate, and Group III (n = 25) received the standard course of methotrexate plus viable buffy-coat cells from the marrow donors. All 109 patients received cyclophosphamide (60 mg per kilogram of body weight on each of two days), total-body irradiation (2.25 Gy daily for seven days), and unmodified marrow from HLA-identical sibling donors. The frequency of GVHD of Grades II through IV was 25 percent in Group I, 59 percent in Group II, and 82 percent in Group III (P = 0.0001). The incidence of chronic GVHD, however, did not differ significantly among the groups (33, 51, and 44 percent, respectively), nor did the five-year probability of recurrence of disease (38, 45, and 33 percent, respectively). However, mortality from causes other than cancer was 34 percent in Group I, 45 percent in Group II, and 64 percent in Group III (I vs. III, P = 0.024); the deaths were due primarily to infections complicating the course of GVHD. With a median follow-up of 5.1 years (range, 3.9 to 7.4), disease-free survival was 41 percent in Group I, 30 percent in Group II, and 24 percent in Group III (the differences were not statistically significant). We conclude that abbreviating methotrexate prophylaxis or infusing donor buffy-coat cells increased the incidence of acute GVHD and related mortality without altering the incidence of chronic GVHD or the recurrence of malignant disease.     

The changing survival profile of people with Down's syndrome: implications for genetic counselling

Cohort studies have indicated that the survival of individuals with Down's syndrome has dramatically increased over the past 50 years. Early childhood survival in particular has shown major improvement, due largely to advances in cardiac surgery and in general health management. The present study was based on a continuous cohort of 1332 people with Down's syndrome in Western Australia, registered for intellectual disability services between 1953 and 2000. Their life expectancy was 58.6 years, 25% lived to 62.9 years, and the oldest living person is 73 years of age. Life expectancy for males was greater than females by 3.3 years. The substantial increase in survival across the study period means that the life expectancy of people with Down's syndrome is approaching that of the general population, but accompanied by a range of significant mid-life health problems. The findings are of relevance to all developed countries and have considerable implications in terms of the counselling information provided to families at risk of having a child with Down's syndrome.