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61.
Elkins MK Vittinghoff E Baranzini SE Hecht FM Sriram U Busch MP Levy JA Oksenberg JR;San Francisco Primary Infection Group 《Genes and immunity》2005,6(1):66-69
In chronically HIV infected individuals, a number of functional B cell abnormalities have been described. However, the immediate changes that occur in the B cell compartment following viral exposure and how they affect the long-term course of infection are not well understood. We report the longitudinal analysis of B cell repertoires during early infection in untreated and treated individuals receiving highly active antiretroviral therapy (HAART). Analysis was based on IgG heavy chain gene utilization and CDR3 length measurement and relationship with CD4/CD8 counts, viral load, and total serum IgG, and anti-HIV antibodies levels. Repertoires were assessed at baseline and at weeks 2, 4, 12, 24, and 72 after initiation of therapy. The findings indicate a stable peripheral B cell repertoire during the first 72 weeks following infection, particularly in the HAART treated patients. A modest association between B cell repertoire integrity and viremia levels as well as treatment was detected. 相似文献
62.
Risk factors for incident HIV infection among anonymous HIV testing site clients in Santos,Brazil: 1996-1999 总被引:1,自引:0,他引:1
Alves K Shafer KP Caseiro M Rutherford G Falcao ME Sucupira MC Busch MP Rawal BD Diaz RS 《Journal of acquired immune deficiency syndromes (1999)》2003,32(5):551-559
OBJECTIVES: To determine temporal trends in HIV infection and risk factors among persons seeking anonymous HIV testing in Santos, Brazil. METHODS: Data and sera from persons testing for HIV from 1996 to 1999 were used. Exposures were abstracted from HIV testing risk assessments. Stored HIV-positive sera were tested to identify recently acquired HIV infection using a serologic testing algorithm for detecting recent HIV seroconversion (STARHS). Independent associations between exposures and recently acquired HIV infection were determined using multivariate analyses. RESULTS: Overall, estimated HIV incidence was 2.0% (95% CI: 1.1-3.5) for the 4-year period: 1.2% (95% CI: 0.5-2.6) in women and 2.7% (95% CI: 1.3-5.0) in men. Incidence increased among women but remained stable among men. Exposures independently associated with incident infection included a history of sex work (OR= 5.4, 95% CI: 1.5-18.7), concurrent syphilis infection (OR =4.1, 95% CI: 1.4-11.9), anal sex (OR = 3.0, 95% CI: 1.3-7.1), and having an HIV-positive sexual partner (OR= 1.4, 95% CI: 1.1-1.9). CONCLUSIONS: This study further demonstrates the public health utility of using the STARHS for the assessment of emerging trends in the HIV epidemic. Results from this study will help to target appropriate prevention strategies directed toward at-risk populations in Santos. 相似文献
63.
Somatic mutation processes at a human minisatellite 总被引:6,自引:3,他引:6
Germline instability at human minisatellites frequently involves complex
inter-allelic transfers of repeat units usually restricted to one end of
the repeat array and apparently regulated by flanking DNA. In contrast,
nothing is known about the structural basis of somatic instability at
minisatellites. An electrophoretic size-enrichment strategy was therefore
developed at minisatellite MS32 (D1S8) to enable rare abnormal-length
mutants to be detected, validated and quantitated in blood DNA by single
molecule PCR. Structural analysis of rare mutant alleles in blood revealed
simple deletions/duplications of repeat unit blocks located at random along
the tandem repeat array, a mode of mutation completely different from that
seen in sperm. Furthermore, allele-specific suppression of sperm
instability at MS32 did not affect somatic instability. These data suggest
that conversion-based minisatellite mutation in sperm is completely
germline-specific and most likely meiotic in origin. Somatic instability
appears to occur by a separate pathway involving replication slippage or,
more likely, intra-allelic unequal crossing over.
相似文献
64.
Mutations in the TSC2 gene: analysis of the complete coding sequence using the protein truncation test (PTT) 总被引:4,自引:0,他引:4
Mutations in the TSC2 gene on chromosome 16p13.3 are responsible for
approximately 50% of familial tuberous sclerosis (TSC). The gene has 41
small exons spanning 45 kb of genomic DNA and encoding a 5.5 kb mRNA. Large
germline deletions of TSC2 occur in <5% of cases, and a number of small
intragenic mutations have been described. We analysed mRNA from 18
unrelated cases of TSC for TSC2 mutations using the protein truncation test
(PTT). Three cases were predicted to be TSC2 mutations on the basis of
linkage analysis or because a hamartoma from the patient showed loss of
heterozygosity for 16p13.3 markers. Three overlapping PCR products,
covering the complete coding sequence of mRNA, were generated from
lymphoblastoid cell lines, translated into 35S-methionine labelled protein,
and analysed by SDS-PAGE. PCR products showing PTT shifts were directly
sequenced, and mutations confirmed by restriction enzyme digestion where
possible. Six PTT shifts were identified. Five of these were caused by
mutations predicted to produce a truncated protein: (i) a sporadic case
showed a 32 bp deletion in exon 11, and a mutant mRNA without exon 11 was
produced; the normal exon 10 was also spliced out; (ii) a sporadic case had
a 1 bp deletion in exon 12 (1634delT); (iii) a TSC2-linked mother and
daughter pair had a G-->T transversion in exon 23 (G2715T) introducing a
cryptic splice site causing a 29 bp truncation of mRNA from exon 23; (iv) a
sporadic case showed a 2 bp deletion in exon 36; (v) a sporadic case showed
a 1 bp insertion disrupting the donor splice site of exon 37 (5007+2insA),
resulting in the use of an upstream exonic cryptic splice site to cause a
29 bp truncation of mRNA from exon 37. In one case, the PTT shift was
explained by in-frame splicing out of exon 10, in the presence of a normal
exon 10 genomic sequence. Alternative splicing of exon 10 of the TSC2 gene
may be a normal variant. Three 3rd base substitution polymorphisms were
also detected during direct sequencing of PCR products. Confirmed mutations
were identified in 28% of the families studied and on the assumption that
half of the sporadic cases should have TSC2 mutations, a crude estimate of
the detection rate would be 60%. This compares favourably with other
screening methods used for TSC2, notably SSCP, and since PTT involves much
less work it may be the method of choice.
相似文献
65.
Yajima T Nishimura H Ishimitsu R Yamamura K Watase T Busch DH Pamer EG Kuwano H Yoshikai Y 《European journal of immunology》2001,31(3):757-766
We recently constructed IL-15 transgenic (Tg) mice using cDNA encoding a secretable isoform of the IL-15 precursor protein under the control of an MHC class I promoter. The IL-15 Tg mice exhibited resistance against a primary infection with Listeria monocytogenes. The numbers of memory CD8(+) T cells were markedly increased in the IL-15 Tg mice following Listeria infection accompanied by sustained IL-15 production. The increased CD44(+)CD8(+) T cells in the infected IL-15 Tg mice were not specialized to recognize Listeria-specific antigen but produced a large amount of IFN-gamma in response to bystander stimulation exogenous IL-15 in combination with IL-12. Furthermore, Listeria-specific Th1 response by CD4(+) T cells was significantly augmented in the IL-15 Tg mice compared with control mice following Listeria infection. In vivo depletion of the CD8(+) T cells by anti-CD8 monoclonal antibody and adoptive transfer of the T cells from naive IL-15 Tg mice indicated that the CD8(+) T cells functioned not only to eliminate bacteria at the early stage of infection but also to promote Th1 response to L. monocytogenes. Overexpression of IL-15 shed light on a novel role of memory CD8(+) T cells in early protection and promotion of Th1 response against a primary infection with L. monocytogenes. 相似文献
66.
Screening of selected male blood donors for p24 antigen of human immunodeficiency virus type 1. The Transfusion Safety Study Group 总被引:1,自引:0,他引:1
M P Busch P E Taylor B A Lenes S H Kleinman M Stuart C E Stevens P A Tomasulo J P Allain C G Hollingsworth J W Mosley 《The New England journal of medicine》1990,323(19):1308-1312
BACKGROUND. The p24 antigen of human immunodeficiency virus type 1 (HIV-1) is sometimes detected before antibody (anti-HIV-1) is detectable in the serum of recently infected persons. This has led to the consideration of p24-antigen testing for routine screening of blood donors. METHODS. To estimate how many HIV-infected seronegative donors would be identified if p24-antigen screening was introduced, we tested selected donations from a repository of 200,000 serum samples from voluntary donors that was established in late 1984 and early 1985. The 8597 serum samples selected for p24-antigen screening were chosen because their donors had demographic characteristics known to be associated with a high prevalence of seropositivity. RESULTS. The prevalence of anti-HIV-1 antibodies in the 1984-1985 serum samples selected for p24-antigen screening was 1.54 percent--more than 100 times the 0.012 percent prevalence in present-day donations in the United States. The antigen was detected in 15 of 132 serum samples (11.4 percent) from donors who had already been confirmed as seropositive. No instance of confirmed positivity for p24 antigen was found among the 8465 seronegative serum samples. CONCLUSIONS. These data indicate that the yield of screening for p24 antigen in volunteer donors to identify HIV-1 carriers would be negligible. We therefore recommend against routine screening with currently available p24-antigen assays. 相似文献
67.
Detecting pre-ovulatory luteinizing hormone surges in urine 总被引:2,自引:1,他引:2
Kesner JS; Knecht EA; Krieg EF Jr; Wilcox AJ; O'Connor JF 《Human reproduction (Oxford, England)》1998,13(1):15-21
The study objectives were to determine (i) if pre-ovulatory luteinizing
hormone (LH) surges, undetected in urine by two immunoradiometric assays
(IRMA), were detectable by an ultrasensitive immunofluorometric assay
(IFMA) and (ii) the influence of creatinine adjustment on the detection and
timing of the urinary LH surges. Daily urine specimens were contributed by
healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for
an epidemiological study conducted in 1983-1985. Specimens were selected as
having been previously assayed by two IRMA without consistently detecting
LH surges. These urine specimens were remeasured using an IFMA and adjusted
for creatinine concentration. IFMA measurements revealed unambiguous LH
surges in all cycles. Adjusting IRMA urinary LH values for creatinine
concentrations revealed previously undetected LH surges in four of eight
cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH
surges by 1-5 days. These results demonstrate an IFMA that detects pre-
ovulatory LH surges in unpreserved, frozen urine from cycles where such
surges were previously undetectable. Further, creatinine adjustment can
markedly affect detection and timing of the onset and peak of the urinary
LH surge. While our analysis suggests that this adjustment improves the
validity of the LH measure, this requires further investigation.
相似文献
68.
We performed a randomized doubled-blind study to evaluate whether there was a benefit in delay in tourniquet deflation with intra-articular administration of morphine and bupivacaine following operative arthroscopic surgery. In 34 patients the tourniquet was deflated immediately and in 38 patients the tourniquet remained inflated for 10 min following injection. The analgesic efficacy was assessed using pain scores and the amount of supplementary analgesia required. The results demonstrate no benefit in delay in tourniquet deflation. 相似文献
69.
70.
Differences in maintenance of CD8+ and CD4+ bacteria-specific effector-memory T cell populations 总被引:1,自引:0,他引:1
Schiemann M Busch V Linkemann K Huster KM Busch DH 《European journal of immunology》2003,33(10):2875-2885
Our knowledge about the kinetics and dynamics of complex pathogen-specific CD8(+) T cell responses and the in vivo development of CD8(+) memory T cells has increased substantially over the past years; in comparison, relatively little is known about the CD4(+) T cell compartment. We monitored and directly compared the phenotypical changes of pathogen (Listeria monocytogenes)-specific CD8(+) and CD4(+) T cell responses under conditions leading to effective and long-lasting protective immunity. We found that the general kinetics of bacteria-specific CD8(+) and CD4(+) T cells during the effector and post-effector phases are synchronized. However, later during the memory phase, CD8(+) and CD4(+) T cell populations differ substantially. Whereas CD8(+) memory T cell populations with immediate effector function are readily detectable in lymphoid and non-lymphoid tissues and remain remarkably stable in size, antigen-specific CD4(+) effector-memory T cells decline continuously in frequency over time. These findings have important implications for the better understanding of the in vivo development of protective immunity towards intracellular pathogens. 相似文献