Meta-analysis of APOE genotype and subarachnoid hemorrhage: Clinical outcome and delayed ischemia

BACKGROUND

Emerging evidence suggests that the APOE4 allele may increase the risk of a negative outcome in patients with aneurysmal subarachnoid hemorrhage (SAH), but the results are conflicting. A genetic variable predicting the individual clinical course is currently lacking.

OBJECTIVE

To examine the association between the APOE4 allele and a negative outcome. A secondary objective was to investigate the association between the APOE4 allele and delayed ischemia, a major complication of SAH.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Library, CINHAL, LILACS, and www.google.it through March 2006. We hand-searched journals, international conference proceedings, and reference lists of retrieved articles. Individual patient data were requested from the corresponding authors of the original articles. Information on study design, participant characteristics, clinical outcome, delayed ischemia, and confounder distribution were independently abstracted by two investigators.

RESULTS

We included eight observational studies (696 patients for the clinical outcome and 600 for the delayed ischemia analyses). The corresponding authors of all the retrieved publications but one gave their original data. Summary odds ratios (ORs) were calculated by means of the random-effect model. The risk of a negative outcome (OR = 2.558; 95% CI 1.610 to 4.065) and delayed ischemia (OR = 2.044; 95% CI 1.269 to 3.291) were increased in the E4 carriers.

CONCLUSIONS

In patients with subarachnoid hemorrhage, the expression of the E4 allele is associated with a higher risk of a negative outcome and delayed ischemia.

Simulating leukocyte-venule interactions--a novel agent-oriented approach

Leukocyte recruitment into sites of inflammation involves a complex cascade of molecular interactions between the leukocyte and the endothelial cells of the inflamed venule. This report proposes a novel agent-oriented approach for simulating leukocyte-venule interactions during inflammation. We focus on modeling and simulating the initial steps of rolling, activation, and firm adhesion of neutrophils on TNF-alpha-treated mouse cremaster muscle venules.

Multiscale carbon nanotube-carbon fiber reinforcement for advanced epoxy composites

We report an approach to the development of advanced structural composites based on engineered multiscale carbon nanotube-carbon fiber reinforcement. Electrophoresis was utilized for the selective deposition of multi- and single-walled carbon nanotubes (CNTs) on woven carbon fabric. The CNT-coated carbon fabric panels were subsequently infiltrated with epoxy resin using vacuum-assisted resin transfer molding (VARTM) to fabricate multiscale hybrid composites in which the nanotubes were completely integrated into the fiber bundles and reinforced the matrix-rich regions. The carbon nanotube/carbon fabric/epoxy composites showed approximately 30% enhancement of the interlaminar shear strength as compared to that of carbon fiber/epoxy composites without carbon nanotubes and demonstrate significantly improved out-of-plane electrical conductivity.

CCL3L1 and CCL4L1: variable gene copy number in adolescents with and without human immunodeficiency virus type 1 (HIV-1) infection

As members of the chemokine family, macrophage inflammatory protein 1 alpha (MIP-1alpha) and MIP-1beta are unique in that they both consist of non-allelic isoforms encoded by different genes, namely chemokine (C-C motif) ligand 3 (CCL3), CCL4, CCL3-like 1 (CCL3L1) and CCL4L1. The products of these genes and of CCL5 (encoding RANTES, i.e., regulated on activation, normal T expressed and secreted) can block or interfere with human immunodeficiency virus type 1 (HIV-1) infection through competitive binding to chemokine (C-C motif) receptor 5 (CCR5). Our analyses of 411 adolescents confirmed that CCL3 and CCL4 genes occurred invariably as single copies (two per diploid genome), whereas the copy numbers of CCL3L1 and CCL4L1 varied extensively (0-11 and 1-6 copies, respectively). Neither CCL3L1 nor CCL4L1 gene copy number variation showed appreciable impact on susceptibility to or control of HIV-1 infection. Within individuals, linear correlation between CCL3L1 and CCL4L1 copy numbers was moderate regardless of ethnicity (Pearson correlation coefficients=0.63-0.65, P<0.0001), suggesting that the two loci are not always within the same segmental duplication unit. Persistently low serum MIP-1alpha and MIP-1beta (in the pg/ml range) compared with high CCL5 concentration (ng/ml range) implied that multi-copy genes CCL3L1 and CCL4L1 conferred little advantage in the intensity of expression among uninfected or infected adolescents.

Imaging informational conflict: a functional magnetic resonance imaging study of numerical stroop

We employed a parametric version of the comparison Stroop paradigm to investigate the processing of numerical magnitude and physical size under task-relevant and -irrelevant conditions to investigate two theoretical issues: (1) What is the neural fate of task-irrelevant information? (2) What is the neural basis of the resolution of the conflict between task-relevant and -irrelevant information? We show in 18 healthy adults that numerical magnitudes of numbers call for higher processing requirements than physical sizes. The enhanced activation elicited by numerical magnitudes is not modulated by task relevance, indicating autonomous processing. Moreover, the normal behavioral distance effect when the numerical dimension is task relevant and reversed distance effect when it is not show that autonomous processing fully encodes numerical magnitudes. Conflict trials elicited greater activation in bilateral inferior frontal gyri, right middle frontal gyri, and right superior frontal gyri. We postulate two sources to the conflict, namely, at cognitive and response levels.

Effect of lysed Enterococcus faecalis FK-23 on allergen-induced immune responses and intestinal microflora in antibiotic-treated weaning mice

BACKGROUND

Recent epidemiological studies have indicated that early life receipt of antibiotics may be associated with an increased risk of developing atopic disorder. Lysed Enterococcus faecalis FK-23 (LFK), a probiotic product of E faecalis, has been shown to have inhibitory effects on allergen-induced immune responses in mice.

OBJECTIVE

The purpose of this study was to evaluate the effects of LFK on immune responses and intestinal microflora in antibiotic-treated, and allergen-sensitized weaning mice.

METHODS

Three-week-old BALB/c mice were sensitized with cedar pollen allergen to establish the experimental model. The allergen-induced peritoneal accumulation of eosinophils, serum levels of total and allergen-specific immunoglobulin (Ig) E and IgG2a, and the intestinal bacterial flora were determined in the control, antibiotic, LFK and antibiotic-LFK groups (n = 7 in all groups). Orally administered erythromycin, one kind of macrolide antibiotic, was used for the experiments.

RESULTS

There was no significant difference in the allergen-induced peritoneal accumulation of eosinophils and serum specific IgE and IgG2a levels in erythromycin-treated mice compared to a control group. However, the ratio of serum total IgE to IgG2a levels was significantly increased in erythromycin-treated mice relative to that found either in LFK-treated mice or in erythromycin-treated mice with LFK supplementation. The total aerobes, total anaerobes and Enterococcus species of intestinal microflora were not significantly different among all groups. Lactobacillus species were distinctly eliminated in the mice exposed to erythromycin on day 7 and totally recovered in erythromycin-treated mice with LFK intervention on day 28, but could not be recovered in the erythromycin-treated mice without LFK intervention.

CONCLUSIONS

Our results suggest that LFK may improve the intestinal ecosystem disturbed by antibiotic use, and thereby prevent subsequent development of atopy. However, whether different antibiotics have different effects on immune responses needs to be addressed further.

Changes in the inferior alveolar nerve following sagittal split ramus osteotomy in monkeys: a comparison of monocortical and bicortical fixation

We aimed to observe the changes in the inferior alveolar nerve (IAN) after bilateral sagittal split ramus osteotomy (SSRO) using monocortical or bicortical screw fixation. Bilateral SSRO for setback of the mandible was done in 12 monkeys, and monocortical or bicortical fixation was applied on opposing sides of each mandible. Sensory nerve action potentials were tested before and immediately after operation, and at 2, 4, 8, and 12 weeks. Six animals selected randomly were killed at 4 and 12 weeks after the operation. Specimens of nerve were harvested and processed for histological examination and electron microscopic analysis. Obvious prolongation of latency and diminution of amplitude in the IAN were found postoperatively. At 4 weeks after operation, Wallerian degeneration was apparent, and there were signs of axonal regeneration in the nerves. The IAN had more abnormalities of evoked potentials and pathological changes after bicortical than after monocortical fixation. Although considerable recovery was found after both forms of fixation at 12 weeks, the function of the nerve after plate fixation was better than after screw fixation. Our results suggest that the nerve damage during SSRO could be temporary and reversible, and monocortical fixation may result in restoration of the nerve function sooner than bicortical fixation.

Tissue- and bone cell-specific expression of bone sialoprotein is directed by a 9.0 kb promoter in transgenic mice

Bone sialoprotein (BSP) is a phosphorylated glycoprotein that is expressed almost exclusively in mineralizing connective tissues. In bone, expression of BSP correlates with the differentiation of osteoblasts and the onset of mineralization. To determine how the tissue- and differentiation-specific transcription of BSP is regulated, various lengths of promoter sequence were ligated to a luciferase reporter and stably transfected into a rat stromal bone marrow cell line, RBMC-D8 and undifferentiated C3H10T1/2 cells. Luciferase transcription of reporter constructs including 5.4 kb (mBSP5.4Luc) and 9.0 kb (mBSP9.0Luc) of the BSP promoter was strongly up-regulated in parallel with endogenous BSP mRNA in differentiating SBMCs, but not in C3H10T1/2 cells. In contrast, 0.1 kb and 1.4 kb BSP promoter constructs did not show selective expression. To determine tissue-specific expression in vivo, transgenic mice expressing reporter constructs for the 9.0 kb promoter and a 4.8 kb promoter lacking two upstream Cbfa1/Runx2 elements (mBSP9.0Luc and mBSP4.8Luc, respectively) were generated. Analysis of various tissues collected from 1-, 4-, 7-, 14-, and 42-day-old mice revealed extremely high levels of luciferase activity in calvaria, mandible, and tibia of the mBSP9.0Luc mice. In contrast, soft tissues showed negligible luciferase expression. Mice harboring the 4.8 kb transgene also showed selective luciferase expression but displayed a significantly lower activity in mineralized tissues. Northern hybridization of endogenous BSP mRNA and immunostaining of BSP in mBSP9.0Luc mice showed a temporo-spatial expression pattern consistent with the luciferase activity. These results indicate that regulatory elements within the 9.0 kb region of the promoter are required for strong, tissue- and differentiation-specific expression of BSP.

Conserved extended haplotypes of the major histocompatibility complex: further characterization

Since the complete sequencing of a human major histocompatibility complex (MHC) haplotype, interest in non-human leucocyte antigen (HLA) genes encoded in the MHC has been growing. Non-HLA genes, which outnumber the HLA genes, may contribute to or account for HLA and disease associations. Most information on non-HLA genes has been obtained in separate studies of individual loci. To comprehensively address polymorphisms of relevant non-HLA genes in 'conserved extended haplotypes' (CEH), we investigated 101 International Histocompatibility Workshop reference cell lines and nine additional anonymous samples representing all 37 unambiguously characterized CEHs at MICA, NFKBIL1, LTA, NCR3, AIF1, HSPA1A, HSPA1B, BF, NOTCH4 and a single nucleotide polymorphism (SNP) at HLA-DQA1 as well as MICA, NOTCH4, HSPA1B and all five tumour necrosis factor short tandem repeat (STR) polymorphisms. This work (1) provides an extensive catalogue of MHC polymorphisms in all CEHs, (2) unravels interrelationships between HLA and non-HLA haplotypical lineages, (3) resolves reported typing ambiguities and (4) describes haplospecific markers for a number of CEHs. Analysis also identified a DQA1 SNP and segments containing MHC class III polymorphisms that corresponded with class II (DRB3 and DRB4) lineages. These results portray the MHC where lineages containing non-HLA and HLA variants in linkage disequilibrium may operate in concert and can guide more thorough design and interpretation of HLA-disease relationships.

Interleukin 18 and human immunodeficiency virus type I infection in adolescents and adults

Interleukin (IL)-18, a proinflammatory cytokine, has been recognized recently as an important factor in both treated and untreated patients with human immunodeficiency virus type 1 (HIV-1) infection. Consistent with all earlier reports, our quantification of serum IL-18 concentrations in 88 HIV-1 seropositive, North American adolescents (14-18 years old) revealed a positive correlation with cell-free HIV-1 viral load at two separate visits (Spearman's r = 0.31 and 0.50, respectively, P < 0.01 for both), along with a negative correlation with CD4+ T cell counts (r = -0.31 and -0.35, P < 0.01 for both). In additional analyses of 66 adults (21-58 years old) from Zambia, HIV-1 seroconversion was associated uniformly with elevated IL-18 production (P < 0.0001). These epidemiological relationships were independent of other population-related characteristics, including age, gender and ethnicity. In neither study population could serum IL-18 concentrations be associated with the IL-18 gene (IL18) promoter genotypes defined by five major single nucleotide polymorphisms. Collectively, these findings suggest that circulating IL-18 rather than the IL18 genotype may provide a useful biomarker for HIV-1-related events or outcomes.

A 77-year-old woman with sudden onset of blue discolouration of right third toe

We report on a 77-year-old woman with a history of peripheral vascular disease who presented with an acute-onset tender blue toe and deteriorating renal function. A clinical diagnosis of blue toe syndrome was made but the patient deteriorated rapidly and died. This case illustrates the rapidly devastating nature and fatality of blue toe syndrome. There is no effective treatment for this condition.

Clinicopathology of gout in growing layers induced by high calcium and high protein diets

1. An experiment was conducted to test the independent and combined effects of high dietary calcium and protein concentrations on the induction of visceral gout in growing birds of a layer strain. 2. One hundred and sixty healthy birds were randomly divided into 4 groups at 35 d of age. The different groups were given 4 diets containing normal or high concentrations of dietary calcium or crude protein in a 2 x 2 factorial experiment for 30 d. The diets contained normal calcium (Ca) and crude protein (CP) (NCNP, 8.5 g Ca/kg and 175g CP/kg), high calcium and normal protein (HC, 36.3 g Ca/kg and 175 g CP/kg), normal calcium and high protein (HP, 8.8 g Ca/kg and 245 g CP/kg) or high calcium and high protein (HCHP, 36.8 g Ca/kg and 242 g CP/kg), respectively. 3. Typical visceral gout was induced by the HCHP diet. The HCHP and HC diet caused severe kidney damage. The HP diet did not cause kidney damage, but significantly increased plasma uric acid and inorganic phosphorus concentrations. 4. The HC diet significantly increased plasma uric acid, calcium and sodium, but significantly decreased plasma inorganic phosphorus, potassium and magnesium concentrations. The HCHP diet significantly increased plasma uric acid, calcium and sodium. 5. Urine volumes were significantly higher on the HCHP and HC diets than on the control. The growers raised on HC and HCHP diets had significantly higher total quantity of 24 h urinary excretion of uric acid, calcium, magnesium, inorganic phosphorus and potassium and a significantly lower 24 h urinary excretion of sodium. The growers fed on the HP diet had a higher 24 h urinary excretion of uric acid and inorganic phosphorus than the control. 6. It is concluded that growing layer birds should not be fed on layer rations.

Interleukin (IL)-2 and IL-12 responses to Chlamydia trachomatis infection in adolescents

Chlamydia trachomatis infects epithelial cells at the mucosal surface. While in vitro and animal studies have shown changes in mucosal T(H)1-associated cytokines in the presence of C. trachomatis infection and with its progression to the upper genital tract or clearance, in vivo cytokine responses to chlamydial infection in humans are not well understood. Using a quantitative enzyme-linked immunosorbent assay (ELISA), we examined the endocervical production of two T(H)1-associated cytokines, i.e. interleukin (IL)-2 and IL-12, in relation to C. trachomatis infection in adolescents. At a randomly selected visit for 396 females, median endocervical IL-2 levels were significantly lower (190 versus 283 pg/ml, P = 0.02) and median IL-12 levels significantly higher (307 versus 132 pg/ml, P < 0.001) in subjects testing positive versus negative for C. trachomatis. These divergent T(H)1-associated cytokine responses were: (1) confirmed in paired analyses of 96 individuals before and after infection within 6-month intervals, (2) reversible in 97 patients who cleared infection during consecutive visits, (3) not attributable to sociodemographic factors or other genital infections and (4) independent of common genetic variants at the IL2 and IL12B loci associated previously with differential gene expression. From these findings we infer that increased IL-12 and decreased IL-2, observed commonly during mucosal inflammation, are important features of mucosal immune defence against C. trachomatis infection.