Characterization of ICAM-2 and evidence for a third counter-receptor for LFA-1

In an endeavor to further characterize human intercellular adhesion molecule-2 (ICAM-2), two murine monoclonal antibodies (mAb) were generated to ICAM-2 transfected COS cells, and designated CBR-IC2/1 and CBR-IC2/2. Immunoprecipitated, reduced ICAM-2 migrated as a broad band of Mr 60,000 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Treatment with N-glycanase revealed a peptide backbone of Mr 31,000, consistent with the size predicted from the cDNA. ICAM-2 had a broad distribution on hematopoietic cell lines and little expression on other cell lines, the sole exception being cultured endothelial cells which possess high levels of ICAM-2. Resting lymphocytes and monocytes expressed ICAM-2, while neutrophils did not. Staining of tissue sections with anti-ICAM-2 mAb confirmed their strong reactivity to vascular endothelium, but demonstrated a lack of ICAM-2 expression on other tissues. Small clusters of ICAM-2 positive cells were, however, seen in germinal centers. In contrast to ICAM-1 there was little or no induction of ICAM-2 expression on lymphocytes or cultured endothelium upon stimulation with inflammatory mediators. One of the two mAb, CBR-IC2/2, was found to totally inhibit binding of ICAM-2+ COS cells to purified lymphocyte function-associated antigen-1 (LFA-1). Using this mAb, LFA-1-dependent binding to both stimulated and unstimulated endothelium was found to be totally accounted for by ICAM-1 and ICAM-2. Homotypic aggregation of an Epstein-Barr virus-transformed B cell line, JY, was found to be solely ICAM-1 and ICAM-2-dependent, while in the case of the T cell lymphoma cell line, SKW3, anti- ICAM-2 mAb in conjunction with anti-ICAM-1 mAb could not inhibit the LFA-1-dependent aggregation. This suggests an additional LFA-1 ligand exists. Using a cell binding assay to purified LFA-1 in conjunction with anti-ICAM-1 and anti-ICAM-2 mAb, we have demonstrated that this putative third ligand for LFA-1 exists on SKW3 and other cell lines.     

ceRA: an RH allele variant producing a new rare blood

BACKGROUND: Antibodies against RH antigens are clinically significant. Some rare RH phenotypes, for example, RH:-46 (R(N)), RH:-18 (Hr(s)-), RH:-34 (Hr(b)-), and homozygous partial RH5 (e), are found exclusively in black persons of African descent. Quantitative and qualitative RHCE variants require characterization because the presence of these alleles can lead to difficulties when transfusion is needed. STUDY DESIGN AND METHODS: Here a new RH5 variant (ceRA) in an Indian patient is described and investigated by serology (agglutination and flow cytometry analysis) and molecular and immunoblot analysis. RESULTS: Red blood cells (RBCs), typed as RH:-1,-2, -3,4,w5, expressed a very depressed RH5 antigen, with no expression of the RH19 (h) high-frequency antigen. Molecular analysis revealed a new Rhce allele (homozygous state), hereafter called ceRA. This new allele exhibited a G48C mutation in exon 1 and a G538C mutation in exon 4, predicting, respectively, a Trp16Cys substitution and a Gly180Arg substitution, both in the intramembranous domain of the Rhce polypeptide. Immunoblot analysis showed that this defect results in a dramatic loss of the amount of RHCE polypeptides within the RBC membrane. No reactivity was evidenced with most of anti-RH5, in agglutination as well as in flow cytometry techniques. CONCLUSION: Both serologic results and localization of the Gly180Arg substitution emphasize the risk of anti-RH5 alloimmunization for patients expressing this new allele ceRA at the homozygous state. These results point out the importance of obtaining blood donations for the frozen rare blood bank in case future transfusion is needed.     

Developing an evidence base for interdisciplinary learning: a systematic review

AIM OF THE STUDY: The overall aim of the study was to explore the feasibility of introducing interdisciplinary education within undergraduate health professional programmes. This paper reports on the first stage of the study in which a systematic review was conducted to summarize the evidence for interdisciplinary education of undergraduate health professional students. METHODS: Systematic reviews integrate valid information providing a basis for rational decision making about health care which should be based on empirical and not anecdotal evidence. The accepted principles for systematic reviews were adapted in order to allow integration of the literature to produce recommendations for educational practice and guidelines for future research. FINDINGS: The literature on interdisciplinary education was found to be diverse, including relatively small amounts of research data and much larger amounts of evaluation literature. Methodological rating schemes were used to test for confounding influences in the research studies. The number of studies found was 141 but only 30 (21%) were included in the analysis because of lack of methodological rigour in the research and poorly developed outcome measures. CONCLUSIONS: Student health professionals were found to benefit from interdisciplinary education with outcome effects primarily relating to changes in knowledge, skills, attitudes and beliefs. Effects upon professional practice were not discernible and educational and psychological theories were rarely used to guide the development of the educational interventions.     

The first compound heterozygosity for HKalpha alpha allele and Southeast Asian deletion allele

BACKGROUND: In one program of newborn screening to detect deletional alpha-thalassemia with microarray, the microarray result of a 10-month-old girl showed that she was positive for the rightward deletion junction fragment, the Southeast Asian deletion junction fragment and alpha2. STUDY DESIGN: The girl and her parents were subjected to haematological and molecular analysis. RESULTS: The haematological data revealed that the family presented a typical alpha-thalassemic trait. The molecular analysis showed that the girl and her mother were compound heterozygosity for HKalpha alpha allele and Southeast Asian deletion allele, and her father is compound heterozygosity for alpha alpha allele and Southeast Asian deletion allele. CONCLUSIONS: We have detected a hitherto unreported compound heterozygosity for HKalpha alpha allele and Southeast Asian deletion allele. This case will provide some clinical implications for PCR-based diagnosis for deletional alpha-thalassemia.     

Induction of cytotoxic T lymphocytes against I-region-coded determinants: in vitro evidence for a third histocompatibility locus in the mouse

Determinants controlled by the I region of the murine H-2 complex provoked the generation of cytotoxic T lymphocytes (CTL) in both a secondary and primary mixed lymphocyte culture. The stimulating determinants appeared to be controlled by loci within the I-A subregion. The target antigens of the CTL generated were present on both lipopolysaccharide- and concanavalin-induced blast lymphocytes, but were barely detectable on phytohemagglutinin-induced blast cells. The stimulating capacity for CTL induction of a complete H-2 complex incompatibility by far exceeded the sum of H-2D/K-region and I-region incompatibility, respectively.     

A naturally occurring LeuVal mutation in beta3-integrin impairs the HPA-1a epitope: the third allele of HPA-1

BACKGROUND: Single-amino-acid substitution Leu33Pro in the beta3-integrin is responsible for the formation of the human platelet antigen (HPA)-1. Alloimmunization against HPA-1a (beta3-Leu33) is the most frequent cause of neonatal alloimmune thrombocytopenia and posttransfusion purpura. STUDY DESIGN AND METHODS: While HPA-1 genotyping a large cohort of patients with thromboembolic disease with a thermal cycler (LightCycler), one patient was identified with a unique HPA-1a melting curve. RESULTS: Sequence analysis revealed a C-to-G transversion at nucleotide 175 in the beta3-integrin (ITGB3) gene that alters the Leu33 codon to Val33. Further genotyping of healthy blood donors (n = 2950) identified one nonrelated Pro33Val33-positive individual. To examine whether the presence of Val33 affected the binding pattern of HPA-1 alloantibodies, transfectants were generated expressing recombinant beta3-Leu33 or beta3-Val33. Interestingly, differences in the reactivity of anti-HPA-1a were observed, with some HPA-1a alloantibodies showing diminished reactivity with beta3-Val33 compared to beta3-Leu33 and others reacting equally with both types. Similar findings were observed with recombinant human HPA-1a antibodies, with one of the three not binding to beta3-Val33. CONCLUSIONS: Our results demonstrate that the naturally occurring Leu33Val mutation in the beta3-integrin can disrupt some HPA-1a epitopes. These findings provide evidence for a heterogeneous humoral response against HPA-1a that may have potential clinical implications for alloimmune thrombocytopenia disorders.     

一个新的等位基因:HLA-A~*1114克隆和序列分析

目的　识别确认中国人群的HLA新等位基因。方法　使用PCR SSP以及以测序为基础的分型 (SBT)技术 ,在HLA分型常规工作中发现 1个与HLA A 110 2基因相关的新基因 ,以基因克隆及DNA测序 ,分析该基因和A 110 2基因序列的差异。结果　该基因和A 110 2基因序列的差异在于外显子 3区域中 ,5 2 4A >G ,5 2 6G>C以及 5 2 7C >G等 3个碱基的取代 ,使密码子 175由组氨酸变为精氨酸 ,密码子 176由丙氨酸变为精氨酸。结论该基因为HLA新等位基因 ,2 0 0 2年 9月已被世界卫生组织HLA因子命名委员会正式命名为HLA A 1114。用PCR SSP方法 ,在 30 0 0名随机造血干细胞供者中 ,未发现其他带有A 1114基因的个体。     

Fatigue, depression, and insomnia: evidence for a symptom cluster in cancer

OBJECTIVES: To review the evidence for considering fatigue, depression, and insomnia as a symptom cluster in cancer. DATA SOURCES: Empirical studies, clinical articles, and review articles. CONCLUSION: The single- and multi-symptom measurement approaches are of limited usefulness in distinguishing fatigue, depression, and insomnia. Studies in which these symptoms have been measured concurrently in patients with cancer yield consistent evidence of high positive correlations. Results do not appear to be solely a function of overlap in measurement approaches. IMPLICATIONS FOR NURSING PRACTICE: Successful management of fatigue, depression, and insomnia in cancer patients are likely to combine pharmacologic and nonpharmacologic therapies.     

Meniere's disease: an evidence based approach to assessment and management

Menière's disease (MD) is frequently over-diagnosed in both primary and secondary care. This is unfortunate given the significant medical and social implications of such a diagnosis. Difficulties may arise in differentiating the patient with true MD from those individuals with less clearly defined disorders of cochleo-vestibular function. In this review, we suggest a practical evidence based approach to assessment and management of the patient with MD.     

Vancomycin Ototoxicity: a Reevaluation in an Era of Increasing Doses

Nephrotoxicity and ototoxicity have historically been documented as relatively rare complications of vancomycin monotherapy. Recent reports have linked aggressive vancomycin dosing strategies to significant risks of nephrotoxicity. We evaluated the rate of high-frequency hearing loss detected by audiometry for patients on vancomycin therapy. For this purpose, we used retrospective case-control analysis of audiometry results for patients on vancomycin therapy for whom baseline and follow-up exams were available. Analysis of 89 patients for whom audiograms were performed after an average of 27 days of vancomycin therapy showed a 12% rate of high-frequency hearing loss, with a trend in univariate analysis toward a higher rate with advanced age. The mean of the highest vancomycin trough levels for both patients with worsening audiograms and those without worsening audiograms was 19 mg/liter. Regression tree modeling demonstrated that for patients <53 years old, the rate of high-frequency hearing loss detected by audiogram was 0%, while for patients >53 years old, the incidence was 19% (P = 0.008). We conclude that a significant rate of high-frequency hearing loss in older patients receiving vancomycin monotherapy was detected by audiometry. While these data urge caution against continued indiscriminate vancomycin dose escalation to treat infections caused by Staphylococcus aureus strains for which vancomycin MICs are 2 mg/liter, further prospective studies are needed to determine the clinical significance and reversibility of these effects.     

HLA-A、B基因对儿童过敏性紫癜的遗传易感性

目的探索HLA—A、B等位基因对内蒙地区汉族儿童过敏性紫癜（AP）的遗传易感性。方法采用病例对照研究方法，引入PCR-SSO技术，在祖籍三代居住内蒙地区、无血缘关系、无与异族通婚史及其他免疫性疚病史和家族史的汉族人群中，选择儿童AP病例组50例和健康儿童对照组96例。作以HLA-A、B等位基因型别分析。基因频率比较在单因素四格表x^2或Fisher检验的基础上，作以多因素logistic回归分析。结果HLA—A※26、HLA—B※35和HLA-B※52基因频率分别是7％、11％和9％。分别与健康对照组的1％、4．7％和3．6％比较，差异有统计学意义（x^2分别是-、4．107和3．639，P分别是0．009、0．043和0．056）。经回归后，Wald分别是4．783、4．205和4．293，P值分别是0．029、0．040和0．038，差异均有统计学意义（均P〈0．05）。B分别是1．782、1．112和1．164，均B〉0；OR分别是5．941、3．041和3．202，均OR〉1。促进发病，其95％可信区间分别是1．203～29．331、1．050～8806和1．065～9627，其内均不包含1，与P意义相符。兼有统计学意义。EF分别是0．647、0．369和0．387，均EF〉0。结论HLA—A※26、HLA—B※35和HLA—B※52等位基因可能是内蒙地区汉族儿童AP发病单体型中的3个遗传易感基因。     

Molecular basis for para-Bombay phenotypes in Chinese persons, including a novel nonfunctional FUT1 allele

BACKGROUND: The para-Bombay phenotype is characterized by H-deficient or H-partially deficient red blood cells (RBCs) in persons who secrete ABH antigens in their saliva. The studies that determined the genotypes for two Chinese individuals with the para-Bombay phenotype are described. STUDY DESIGN AND METHODS: RBC phenotypes were characterized by conventional serologic methods. Exons 6 and 7 of the ABO gene were amplified, as well as the entire coding region for FUT1 and FUT2, with four independence polymerase chain reactions (PCRs) from genomic DNA. PCR products were excised, purified from agarose gels, and sequenced directly. Mutations of FUT1 were identified by TOPO cloning sequencing. RESULTS: For both individuals, RBC ABO genotypes correlated with ABH substances in their saliva. One individual (a patient) had two heterozygous mutations of FUT1 by direct DNA sequencing, namely, a C-->T heterozygous mutation at position 293(C293T) and AG heterozygous deletion (CAGAGAG-->CAGAG) at position 547 to 552. These two mutations were confirmed to be compound heterozygotes; that is, each mutation was determined to be on a separate homologous chromosome by TOPO cloning sequencing. The FUT2 genotype was Se(357)Se(357). The other individual (a blood donor) had an AG deletion at position 547 to 552 homozygous allele in FUT1. The FUT2 genotype was Se(357)Se(357,385). C293T mutation can cause Thr/Met at amino acid position 98. AG deletion at position 547 to 552 caused a reading frameshift and a premature stop codon. CONCLUSION: A novel nonfunctional FUT1 allele C293T was identified in a person with the para-Bombay phenotype. This rare H-deficient phenotype may result from different nonfunctional alleles.