Genome-wide prediction of human VNTRs

Polymorphic minisatellites, also known as variable number of tandem repeats (VNTRs), are tandem repeat regions that show variation in the number of repeat units among chromosomes in a population. Currently, there are no general methods for predicting which minisatellites have a high probability of being polymorphic, given their sequence characteristics. An earlier approach has focused on potentially highly polymorphic and hypervariable minisatellites, which make up only a small fraction of all minisatellites in the human genome. We have developed a model, based on available minisatellite and VNTR sequence data, that predicts the probability that a minisatellite (unit size > or = 6 bp) identified by the computer program Tandem Repeats Finder is polymorphic (VNTR). According to the model, minisatellites with high copy number and high degree of sequence similarity are most likely to be VNTRs. This approach was used to scan the draft sequence of the human genome for VNTRs. A total of 157,549 minisatellite repeats were found, of which 29,224 are predicted to be VNTRs. Contrary to previous results, VNTRs appear to be widespread and abundant throughout the human genome, with an estimated density of 9.1 VNTRs/Mb.     

The sialic acid binding SabA adhesin of Helicobacter pylori is essential for nonopsonic activation of human neutrophils

Infiltration of neutrophils and monocytes into the gastric mucosa is a hallmark of chronic gastritis caused by Helicobacter pylori. Certain H. pylori strains nonopsonized stimulate neutrophils to production of reactive oxygen species causing oxidative damage of the gastric epithelium. Here, the contribution of some H. pylori virulence factors, the blood group antigen-binding adhesin BabA, the sialic acid-binding adhesin SabA, the neutrophil-activating protein HP-NAP, and the vacuolating cytotoxin VacA, to the activation of human neutrophils in terms of adherence, phagocytosis, and oxidative burst was investigated. Neutrophils were challenged with wild type bacteria and isogenic mutants lacking BabA, SabA, HP-NAP, or VacA. Mutant and wild type strains lacking SabA had no neutrophil-activating capacity, demonstrating that binding of H. pylori to sialylated neutrophil receptors plays a pivotal initial role in the adherence and phagocytosis of the bacteria and the induction of the oxidative burst. The link between receptor binding and oxidative burst involves a G-protein-linked signaling pathway and downstream activation of phosphatidylinositol 3-kinase as shown by experiments using signal transduction inhibitors. Collectively our data suggest that the sialic acid-binding SabA adhesin is a prerequisite for the nonopsonic activation of human neutrophils and, thus, is a virulence factor important for the pathogenesis of H. pylori infection.     

Changes in mACh, NMDA and GABA(A) receptor binding after lateral fluid-percussion injury: in vitro autoradiography of rat brain frozen sections

Adult rats were subjected to a moderate lateral fluid percussion injury (FPI), followed by survival periods of 2 and 12 h. Regional NMDA subtype glutamate, muscarinic acetylcholine and GABA(A) receptor binding in various brain regions was analysed by quantitative in vitro autoradiography and short-lived positron emission tomography tracers [11C]cyano-dizocilpine, 4-N-[11C]methylpiperidylbenzilate (4-N-[11C]MPB), and [11C]flumazenil, respectively. The binding potential (BP, Bmax/KD) was calculated. The data with [11C]cyano-dizocilpine showed a significant decrease in BP bilaterally for the frontoparietal cortex and hippocampus at both time points, in comparison with that of the sham-operated controls. At 12 h the decrease was significantly more prominent for the ipsilateral cortex and hippocampus than for the contralateral side. The BP of 4-N-[11C]MPB was significantly decreased after 2 h for the trauma-side hippocampus, and after 12 h it had decreased for the trauma-site cortex and the bilateral hippocampus. The [11C]flumazenil exhibited a significant decrease in BP for the trauma-site cortex and the underlying hippocampus by 2 h after the traumatic brain injury. After 12 h a significantly decreased BP was observed only for the trauma-site cortex. The finding of a decreased BP demonstrates the involvement of these receptor systems in the development of cellular dysfunction, which is widespread and not limited to the site of lateral FPI.     

Palaeoisopus,Palaeopantopus andPalaeothea,pycnogonid arthropods from the Lower Devonian Hunsriick Slate,West Germany

Palaeoisopus problematicus andPalaeopantopus maucheri are redescribed and found to be primitive pycnogonids belonging to extinct orders.Palaeoisopus is particularly primitive in retaining a long abdomen with a telson. It differs from other forms also in having flattened limbs indicating a swimming mode of life and in having the ocelli differently arranged.Palaeothea devonica nov. gen. et nov. spec. is a tiny pycnogonid, the only hitherto known fossil representative of the extant order Pantopoda, indicating that entirely modern forms were in existence already in the Early Devonian. A derivation of pycnogonids from early merostomes is regarded as likely.     

IgG Suppresses Antibody Responses in Mice Lacking C1q,C3, Complement Receptors 1 and 2, or IgG Fc-Receptors

Antigen-specific IgG antibodies, passively administered to mice or humans together with large particulate antigens like erythrocytes, can completely suppress the antibody response against the antigen. This is used clinically in Rhesus prophylaxis, where administration of IgG anti-RhD prevents RhD-negative women from becoming immunized against RhD-positive fetal erythrocytes aquired transplacentally. The mechanisms by which IgG suppresses antibody responses are poorly understood. We have here addressed whether complement or Fc-receptors for IgG (FcγRs) are required for IgG-mediated suppression. IgG, specific for sheep red blood cells (SRBC), was administered to mice together with SRBC and the antibody responses analyzed. IgG was able to suppress early IgM- as well as longterm IgG-responses in wildtype mice equally well as in mice lacking FcγRIIB (FcγRIIB knockout mice) or FcγRI, III, and IV (FcRγ knockout mice). Moreover, IgG was able to suppress early IgM responses equally well in mice lacking C1q (C1qA knockout mice), C3 (C3 knockout mice), or complement receptors 1 and 2 (Cr2 knockout mice) as in wildtype mice. Owing to the previously described severely impaired IgG responses in the complement deficient mice, it was difficult to assess whether passively administered IgG further decreased their IgG response. In conclusion, Fc-receptor binding or complement-activation by IgG does not seem to be required for its ability to suppress antibody responses to xenogeneic erythrocytes.     

Is Cadmium Exposure Associated with the Burden,Vulnerability and Rupture of Human Atherosclerotic Plaques?

The general population is exposed to cadmium from food and smoking. Cadmium is a widely spread toxic pollutant that seems to be associated with cardiovascular diseases, although little is known if it contributes to the occurrence of atherosclerotic plaques and the process whereby plaques become vulnerable and are prone to rupture. We tested the hypotheses that cadmium exposure is associated not only with an increased subclinical burden of atherosclerotic plaques in different vascular territories and early signs of plaque vulnerability, but also with cadmium content and plaque-rupture in the clinical phase of the disease. Ultrasound technique was used to measure plaque prevalence and echogenicity in the carotid and femoral arteries in a population sample of women (n = 599) in whom blood cadmium was measured. In addition cadmium was measured in snap-frozen endarterectomies and whole blood obtained from patients who were referred to surgery because of symptomatic carotid plaques (n = 37). Sixteen endarterectomies were divided into three parts corresponding to different flow conditions and plaque vulnerability. In the population sample blood cadmium was associated with the number of vascular territories with plaques (p = 0.003 after adjustment for potential confounders). The cadmium concentrations in symptomatic plaques were 50-fold higher in plaque tissue than in blood. Cadmium levels in blood and plaque correlated, also after adjustment for smoking and other cardiovascular risk factors (p<0.001). Compared with the other parts of the plaque, the cadmium content was double as high in the part where plaque rupture usually occurs. In conclusion, the results show that cadmium exposure is associated with the burden of subclinical atherosclerosis in middle-aged women with different degrees of glucose tolerance, and that the content of cadmium in symptomatic plaques in patients is related to that in blood, but much higher, and preferentially located in the part of plaque where rupture often occurs.     

High Lysyl Oxidase (LOX) in the Non-Malignant Prostate Epithelium Predicts a Poor Outcome in Prostate Cancer Patient Managed by Watchful Waiting

Lysyl oxidase (LOX) has been shown to both promote and suppress tumor progression, but its role in prostate cancer is largely unknown. LOX immunoreactivity was scored in prostate tumor epithelium, tumor stroma and in the tumor-adjacent non-malignant prostate epithelium and stroma. LOX scores in tumor and non-malignant prostate tissues were then examined for possible associations with clinical characteristics and survival in a historical cohort of men that were diagnosed with prostate cancer at transurethral resection and followed by watchful waiting. Men with a low LOX score in the non-malignant prostate epithelium had significantly longer cancer specific survival than men with a high score. Furthermore, LOX score in non-malignant prostate epithelium remained prognostic in a multivariable analysis including Gleason score. LOX score in prostate tumor epithelium positively correlated to Gleason score and metastases but was not associated with cancer survival. LOX score in tumor and non-malignant prostate stroma appeared unrelated to these tumor characteristics. In radical prostatectomy specimens, LOX immune-staining corresponded to LOX in-situ hybridization and LOX mRNA levels were found to be similar between tumor and adjacent non-malignant areas, but significantly increased in bone metastases samples. LOX levels both in tumors and in the surrounding tumor-bearing organ are apparently related to prostate cancer aggressiveness.     

Nurse-Led,Telephone-Based,Secondary Preventive Follow-Up after Stroke or Transient Ischemic Attack Improves Blood Pressure and LDL Cholesterol: Results from the First 12 Months of the Randomized,Controlled NAILED Stroke Risk Factor Trial

Background

Enhanced secondary preventive follow-up after stroke or transient ischemic attack (TIA) is necessary for improved adherence to recommendations regarding blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) levels. We investigated whether nurse-led, telephone-based follow-up was more efficient than usual care at improving BP and LDL-C levels at 12 months after hospital discharge.

Methods

We randomized 537 patients to either nurse-led, telephone-based follow-up (intervention) or usual care (control). BP and LDL-C measurements were performed at 1 month (baseline) and 12 months post-discharge. Intervention group patients who did not meet target values at baseline received additional follow-up, including titration of medication and lifestyle counselling, to reach treatment goals (BP < 140/90 mmHg, LDL-C < 2.5 mmol/L).

Results

At 12 months, mean systolic BP, diastolic BP and LDL-C was 3.3 (95% CI 0.3 to 6.3) mmHg, 2.3 mmHg (95% CI 0.5 to 4.2) and 0.3 mmol/L (95% CI 0.1 to 0.4) lower in the intervention group compared to controls. Among participants with values above the treatment goal at baseline, the difference in systolic BP and LDL-C was more pronounced (8.0 mmHg, 95% CI 4.0 to 12.1, and 0.6 mmol/L, 95% CI 0.4 to 0.9). A larger proportion of the intervention group reached the treatment goal for systolic BP (68.5 vs. 56.8%, p = 0.008) and LDL-C (69.7% vs. 50.4%, p < 0.001).

Conclusions

Nurse-led, telephone-based secondary preventive follow-up, including medication adjustment, was significantly more efficient than usual care at improving BP and LDL-C levels by 12 months post-discharge.

Trial Registration

ISRCTN Registry ISRCTN23868518     

Severe liver disease resembling PSC in mice with K5-Cre mediated deletion of Krüppel-like factor 5 (Klf5)

Transgenic Research - Chronic cholestatic liver diseases including primary sclerosing cholangitis (PSC) present a complex spectrum with regards to the cause, age of manifestation and...