Regional cerebral blood flow correlates with heart period and high-frequency heart period variability during working-memory tasks: Implications for the cortical and subcortical regulation of cardiac autonomic activity

The aim of the present study was to characterize the functional relationships between behaviorally evoked regional brain activation and cardiac autonomic activity in humans. Concurrent estimates of regional cerebral blood flow (rCBF; obtained by positron emission tomography), heart period, and high-frequency heart period variability (HF-HPV; an indicator of cardiac parasympathetic activity) were examined in 93 adults (aged 50-70 years) who performed a series of increasingly difficult working-memory tasks. Increased task difficulty resulted in decreased heart period (indicating cardioacceleration) and decreased HF-HPV (indicating decreased cardiac parasympathetic activity). Task-induced decreases in heart period and HF-HPV were associated with concurrent increases and decreases in rCBF to cortical and subcortical brain regions that are speculated to regulate cardiac autonomic activity during behavioral processes: the medial-prefrontal, insular, and anterior cingulate cortices, the amygdala-hippocampal complex, and the cerebellum. These findings replicate and extend a small number of functional neuroimaging studies that suggest an important role for both cortical and subcortical brain systems in human cardiac autonomic regulation.     

High‐resolution microarray analysis unravels complex Xq28 aberrations in patients and carriers affected by X‐linked blue cone monochromacy

The human X chromosome contains ～1600 genes, about 15% of which have been associated with a specific genetic condition, mainly affecting males. Blue cone monochromacy (BCM) is an X‐linked condition caused by a loss‐of‐function of both the OPN1LW and OPN1MW opsin genes. The cone opsin gene cluster is composed of 2–9 paralogs with 99.8% sequence homology and is susceptible to deletions, duplications, and mutations. Current diagnostic tests employ polymerase chain reaction (PCR)‐based technologies; however, alterations remain undetermined in 10% of patients. Furthermore, carrier testing in females is limited or unavailable. High‐resolution X chromosome‐targeted CGH microarray was applied to test for rearrangements in males with BCM and female carriers from three unrelated families. Pathogenic alterations were revealed in all probands, characterized by sequencing of the breakpoint junctions and quantitative real‐time PCR. In two families, we identified a novel founder mutation that consisted of a complex 3‐kb deletion that embraced the cis‐regulatory locus control region and insertion of an additional aberrant OPN1MW gene. The application of high‐resolution X‐chromosome microarray in clinical diagnosis brings significant advantages in detection of small aberrations that are beyond the resolution of clinically available aCGH analysis and which can improve molecular diagnosis of the known conditions and unravel previously unrecognized X‐linked diseases.     

The effect of spiroarsoranes on Trypanosoma brucei brucei and T. b. rhodesiense

 Topical application and intraperitoneal administration of spiroarsoranes were carried out to cure central nervous system (CNS) trypanosomiasis in the chronic Trypanosoma brucei GVR 35 mouse model. Topical application appeared more efficient than intraperitoneal injection. The periods of aparasitaemia after treatment were longer but none of the mice was permanently cured. Combination treatment with eflornithine (DFMO) and the spiroarsoranes failed to show any synergistic effect. In addition, spiroarsorane I was evaluated against the T. b. rhodesiense KETRI 2634 strain, whereby 60-mg/kg treatment produced a noticeable prolongation of the life span of trypanosome-positive animals. These in vivo results suggests that the spiroarsoranes have difficulty in crossing the blood-brain barrier (BBB) and clearing the parasites from the CNS or, alternatively, that these strains are less sensitive to pentavalent arsenicals than the T. b. brucei CMP fast strain, which in the present study was more sensitive to spiroarsoranes whose lipophilicity corresponded to a log-P value ranging from 2.5 to 3.7. Received: 3 November 1995 / Accepted: 15 January 1996     

Haplotype and interspersion analysis of the FMR1 CGG repeat identifies two different mutational pathways for the origin of the fragile X syndrome

To understand the origins of the fragile X syndrome and factors predisposing alleles to instability and hyperexpansion, we have compared the haplotype (using markers FRAXAC1, FRAXAC2, and DXS548) and AGG interspersion patterns of the FMR1 CGG repeat for 214 normal and 16 premutation chromosomes. Association testing between interspersion pattern and haplotype reveals a highly significant (P < 0.002) non- random distribution, indicating that all three markers are useful in phylogenetic reconstruction of mutational change. Parsimony analysis of the FMR1 CGG repeat substructure predicts that loss of AGG interruptions has occurred independently on many haplotypes associated with the fragile X syndrome, partially explaining the haplotype diversity of this disease. Among haplotypes found in linkage disequilibrium with the fragile X mutation, two different modes of mutation and predisposition to instability have been identified. One pathway has involved the frequent and recurrent loss of AGG interruptions from rare asymmetrical ancestral array structures. Intergenerational transmission studies suggest that these predisposed chromosomes progress relatively rapidly to the disease state. In contrast, the second mutational pathway involves a single haplotype which has maintained two AGG interruptions. Parsimony analysis of CGG repeat substructure within this haplotype suggests that larger alleles have been generated by gradual increments of CGG repeats distal to the most 3' interruption. Pedigree analysis of the intergenerational stability of alleles of this haplotype confirms a gradual progression toward instability thresholds. As a result, a large reservoir of chromosomes carrying large repeats on this haplotype exists. These chromosomes are predisposed to disease. The present data support a model in which there are at least two different mutational pathways predisposing alleles to instability and hyperexpansion associated with the fragile X syndrome.      

Vaccination against IL-17 suppresses autoimmune arthritis and encephalomyelitis

Interleukin 17 is a T cell-derived cytokine that induces the release of pro-inflammatory mediators in a wide range of cell types. Recently, a subset of IL-17-producing T helper cells (Th17) distinct from Th1 and Th2 cells has been described, which constitutes a new T cell polarization state. Aberrant Th17 responses and overexpression of IL-17 have been implicated in a number of autoimmune disorders including rheumatoid arthritis and multiple sclerosis. Molecules blocking IL-17 such as IL-17-specific monoclonal antibodies have proved to be effective in ameliorating disease in animal models. Hitherto, active immunization targeting IL-17 is an untried approach. Herein we explore the potential of neutralizing IL-17 by active immunization using virus-like particles conjugated with recombinant IL-17 (IL-17-VLP). Immunization with IL-17-VLP induced high levels of anti-IL-17 antibodies thereby overcoming natural tolerance, even in the absence of added adjuvant. Mice immunized with IL-17-VLP had lower incidence of disease, slower progression to disease and reduced scores of disease severity in both collagen-induced arthritis and experimental autoimmune encephalomyelitis. Active immunization against IL-17 therefore represents a novel therapeutic approach for the treatment of chronic inflammatory diseases.     

Multicenter evaluation of use of dried blood and plasma spot specimens in quantitative assays for human immunodeficiency virus RNA: measurement,precision, and RNA stability

Eleven laboratories evaluated the use of dried blood and plasma spots for quantitation of human immunodeficiency virus (HIV) RNA by two commercially available RNA assays, the Roche Amplicor HIV-1 Monitor and the bioMerieux NucliSens HIV-1 QT assays. The recovery of HIV RNA was linear over a dynamic range extending from 4,000 to 500,000 HIV type 1 RNA copies/ml. The Monitor assay appeared to have a broader dynamic range and seemed more sensitive at lower concentrations. However, the NucliSens assay gave more consistent results and could be performed without modification of the kit. HIV RNA was stable in dried whole blood or plasma stored at room temperature or at -70 degrees C for up to 1 year. Dried blood and dried plasma spots can be used as an easy and inexpensive means for the collection and storage of specimens under field conditions for the diagnosis of HIV infection and the monitoring of antiretroviral therapy.     

婴幼儿法洛四联症和肺动脉闭锁病例肺血来源的分析

目的探讨法洛四联症和肺动脉闭锁先天性心脏病患儿的肺循环血流来源。方法回顾性分析67例法洛四联症和27例肺动脉闭锁患儿的临床和影像学资料,判断肺循环血流的具体来源。结果94例中单纯肺动脉供血51例,单纯体动脉供血27例,肺-体动脉双重供血16例。单纯体动脉供血或肺-体动脉双重供血病例中,合并单纯动脉导管未闭20例,合并单纯体-肺侧支20例,3例同时合并动脉导管未闭和体-肺侧支,侧支循环的发生率与肺动脉狭窄程度相关。结论法洛四联症和肺动脉闭锁病例肺血来源复杂多样,多数合并动脉导管未闭和(或)体-肺侧支,而且体-肺侧支的发生率较高,对治疗往往产生重要影响。     

Production of calmodulin-tagged proteins in Drosophila Schneider S2 cells: a novel system for antigen production and phage antibody isolation

We report the development of an expression system for the production of soluble, calmodulin (CaM)-tagged proteins in Drosophila Schneider S2 cells and the subsequent use of these proteins for the selection of phage displayed antibodies. The CaM-tag permitted the purification of recombinant protein to >90% purity in a single step at yields of >20 mg/l. Using platelet glycoprotein VI (GP6) as a model, we demonstrated that the recombinant CaM-tagged protein was post-translationally N-glycosylated and had identical ligand specificity to native protein. A novel selection strategy, exploiting the CaM tag, was then used to isolate four single chain Fv fragments (scFvs) specific for GP6 from a non-immune phage display library. In contrast to other selection methods, which can result in antibodies that do not recognise native protein, all of the scFvs we selected bound cell surface expressed GP6. In conclusion, the production of CaM-tagged proteins in Drosophila Schneider S2 cells and the selection strategy reported here offer advantages over previously published methods, including simple culture conditions, rapid protein purification, specific elution of phage antibodies and preferential selection of phage antibodies that recognise native, cell surface expressed protein.