DNA sequencing with chain-terminating inhibitors

A new method for determining nucleotide sequences in DNA is described. It is similar to the "plus and minus" method [Sanger, F. & Coulson, A. R. (1975) J. Mol. Biol. 94, 441-448] but makes use of the 2',3'-dideoxy and arabinonucleoside analogues of the normal deoxynucleoside triphosphates, which act as specific chain-terminating inhibitors of DNA polymerase. The technique has been applied to the DNA of bacteriophage varphiX174 and is more rapid and more accurate than either the plus or the minus method.     

肝炎病毒利用DC-SIGN逃逸机体免疫作用

DC-SIGN是DC表面识别多种病原微生物的受体.一方面,DC借助DC-SIGN对固有免疫及适应性免疫发挥免疫调节作用;另一方面,DC-SIGN又成为某些病原微生物如肝炎病毒借以逃逸机体免疫防御功能的靶分子.我们就DC-SIGN的结构及功能、与病毒的相互作用等方面进行阐述.     

Chylous ascites following aneurysm surgery.

A case of chylous ascites occurring after elective abdominal aortic aneurysm repair is described. The patient was initially managed conservatively with hyperalimentation and intermittent drainage of the retroperitoneal collection, but, this proved inadequate and a peritoneo-venous shunt was inserted. Although the shunt appeared to work well the patient finally died of septicaemia.     

Induction of proliferation of B prolymphocytic leukemia cells by phorbol ester and native or recombinant interferon-gamma

Phorbol ester phorbol myristate acetate (PMA) induces proliferation in nonmalignant human B cells and B cells from a patient with B prolymphocytic leukemia (B-PLL). Mitogen-free T cell-derived conditioned medium acts synergistically with PMA in inducing proliferation of B-PLL cells but does not enhance the PMA-stimulated outgrowth of nonmalignant B cells. Interleukin 2 (IL-2) has no effect on the outgrowth of B-PLL cells, and monoclonal antibodies against the IL-2 receptor do not influence the response to PMA and conditioned medium. Recombinant interferon-gamma (IFN-gamma), in contrast, is a potent enhancer of PMA-induced proliferation of B-PLL cells. With gel filtration techniques and with the use of anti-IFN-gamma antibodies, it is shown that IFN-gamma in the conditioned medium is responsible for the observed increase in B-PLL cell proliferation. Preincubation of B- PLL cells with IFN-gamma induces responsiveness to PMA, whereas IFN- gamma alone had no effect on these cells when pretreated with PMA. The combined data show that, in the presence of PMA, native and recombinant IFN-gamma are growth factors for B cells from a B-PLL patient and that IL-2 is not involved in this process.     

Nonlinear sensory cortex response to simultaneous tactile stimuli in writer's cramp.

Writer's cramp is a task-specific dystonia that leads to involuntary hand postures during writing. Abnormalities of sensory processing may play a pathophysiological role in this disorder. Electrophysiology studies in a monkey model of focal dystonia have revealed de-differentiation of sensory maps and the existence of single cells in hand regions of area 3b with enlarged receptive fields that extend to the surfaces of more than one digit. These changes may lead to abnormal processing of simultaneous sensory inputs. To study abnormal processing of simultaneous sensory information in adult humans with writer's cramp, we used functional magnetic resonance imaging to compare the response in primary sensory cortex with simultaneous tactile stimulation of the index and middle finger, with the response to stimulation of each finger alone. We tested five patients with writer's cramp and seven unaffected (normal) subjects. In the normal subjects, a linear combination of the activation patterns for individual finger stimulation predicts the pattern of activity for combined stimulation with 12% error. In writer's cramp patients, the linear combination predicted the combined stimulation pattern with 30% error. Results indicate a nonlinear interaction between the sensory cortical response to individual finger stimulation in writer's cramp. This altered interaction may contribute to the motor abnormalities.     

High resolution of heterogeneity among human neutrophil granules: physical, biochemical, and ultrastructural properties of isolated fractions

Previous studies on the fractionation of human neutrophil granules have identified two major populations: myeloperoxidase (MPO)-containing azurophil, or primary, granules and MPO-deficient specific, or secondary, granules. Peripheral blood neutrophils from individual donors were lysed in sucrose-free media by either hypotonic shock or nitrogen cavitation. Using a novel two-gradient Percoll density centrifugation system, the granule-rich postnuclear supernatant was rapidly (ten minutes) and reproducibly resolved into 13 granule fractions (L1 through L8 and H1 through H5). Granule flotation and recentrifugation experiments on both continuous, self-generated and multiple-step gradients using individual and mixed isolated fractions demonstrated that the banding patterns were isopycnic and nonartifactual. Isolated granules were intact based on the findings that biochemical latency of several granule enzymes was greater than 95%, and thin-sectioned electron micrographs demonstrated intact granule profiles. Biochemical analyses of the granule marker proteins MPO, beta-glucuronidase, lysozyme, and lactoferrin indicated that a number of the fractions were related to the major azurophil and specific granule populations. Lactoferrin was found in ten of 13 fractions (L1 through L8, H1 to H2), whereas MPO was found in every fraction. Consistent with these biochemical data, all fractions exhibited varying degrees of heterogeneity based on ultrastructural morphology and cytochemistry, including diaminobenzidine (DAB) reactivity for peroxidase and periodate-thiocarbohydrazide-silver proteinate (PA-TCH-SP) staining for complex glycoconjugates. A variable but significant percentage (23% to 70%) of the granules in fractions L1 through L8 and H1 and H2 showed DAB reactivity, while about 90% of the granules in fractions H3 through H5 were peroxidase positive. These results demonstrated that DAB-reactive granules spanned the entire range of granule size and density. Ultrastructural PA-TCH-SP staining of isolated granule fractions revealed patterns similar to those of granules in intact neutrophils at different stages of development. Granules from human acute promyelocytic leukemia cells (HL-60) exhibited a surprisingly low density compared with typical azurophil granules from normal, mature neutrophils. The data suggest that both functional and maturational differences contribute to granule heterogeneity, and provide a new practical and conceptual framework for further defining the phenomenon of neutrophil granule heterogeneity.     

Economic,clinical, and quality-of-life outcomes associated with olanzapine treatment in mania. Results from a randomized controlled trial

INTRODUCTION: The objectives of this study were to determine the economic, clinical, and quality-of-life outcomes associated with olanzapine treatment in patients diagnosed with mania. METHODS: Patients with a diagnosis of bipolar I disorder with manic or mixed episodes were enrolled in a randomized controlled trial. The study design comprised a 3-week acute phase followed by a 49-week open label extension. In the open label extension, the use of lithium and fluoxetine was permitted for patients who experienced breakthrough symptoms. Clinical, economic, and quality-of-life outcomes of treatment were assessed. RESULTS: During the acute phase, olanzapine patients experienced a statistically significant greater mean improvement from baseline on the Y-MRS total score compared to the placebo patients. In the open label extension, patients experienced a statistically significant mean change of 11.8 units on the Y-MRS from the end of the acute phase. When compared to costs incurred in the previous 12 months of therapy, patients experienced savings of almost $900 per month during the 49 weeks of olanzapine therapy. These cost savings were largely driven by reductions in in-patient costs during the open label extension. Health-related quality of life improvements measured by the SF-36 were seen on several dimensions both in the 3-week acute phase as well as in the 49-week open label extension. CONCLUSION: From a clinical, economic, and quality-of-life outcomes standpoint, olanzapine had a significant impact in the treatment of mania, and could be considered a cost-effective treatment option for use in this population if these findings are extrapolated to non-clinical trial populations.     

Molecular basis of aggressive disease in chronic lymphocytic leukemia patients with 11q deletion and trisomy 12 chromosomal abnormalities

In B-cell chronic lymphocytic leukemia (CLL), Rai stage, immunoglobulin gene mutational status, chromosomal abnormalities, CD38 and ZAP-70 expression were used as prognostic markers. In this study, to understand the molecular basis of chromosomal abnormalities leading to tumor progression, 90 CLL patients were grouped into poor prognosis (with 11q deletion and trisomy 12) and good prognosis (with normal karyotype and 13q deletion) and their clinical outcome was assessed. Gene expression profiles of 35 CLL samples with poor outcome (11q deletion, n=9; trisomy 12, n=5) and good outcome (13q deletion, n=13; normal karyotype, n=8) were analyzed using oligonucleotide microarray. Significance analysis of microarray (SAM) identified 27 differentially expressed genes between these two subgroups with significant overexpression of ATF5 and underexpression of CDC16, PCDH8, SLAM, MNDA and ATF2 in CLL patients with poor outcome. ATF5 gene expression in CLL was further studied because of its role in the regulation of cell cycle progression/differentiation and apoptosis. The overexpression of ATF5 was confirmed by real-time PCR using 39 CLL samples from the poor and good outcome groups. ATF5 was significantly (p<0.001) overexpressed in the poor outcome group. Furthermore, ATF5 expression was significantly higher in the 11q deletion as well as trisomy 12 group alone compared to the 13q deletion and normal karyotype groups. ATF5 overexpression was also associated with significantly (p=0.04) shorter time to treatment. Similarly, expression of five underexpressed genes also correlated with longer time to treatment. Thus, this report demonstrates that ATF5 may be one of the key genes involved in increased proliferation and survival in 11q deletion or trisomy 12, whereas CD16, CD86, SLAM, MNDA and ATF2 may be involved in the decreased proliferation of CLL cells with 13q deletion or normal karyotype.