Yersinia pestis caf1 variants and the limits of plague vaccine protection

Yersinia pestis, the highly virulent agent of plague, is a biological weapon. Strategies that prevent plague have been sought for centuries, and immunization with live, attenuated (nonpigmented) strains or subunit vaccines with F1 (Caf1) antigen is considered effective. We show here that immunization with live, attenuated strains generates plague-protective immunity and humoral immune responses against F1 pilus antigen and LcrV. Y. pestis variants lacking caf1 (F1 pili) are not only fully virulent in animal models of bubonic and pneumonic plague but also break through immune responses generated with live, attenuated strains or F1 subunit vaccines. In contrast, immunization with purified LcrV, a protein at the tip of type III needles, generates protective immunity against the wild-type and the fully virulent caf1 mutant strain, in agreement with the notion that LcrV can elicit vaccine protection against both types of virulent plague strains.     

A comparison of 2‐hydroxyglutarate detection at 3 and 7 T with long‐TE semi‐LASER

Abnormally high levels of the ‘oncometabolite’ 2‐hydroxyglutarate (2‐HG) occur in many grade II and III gliomas, and correlate with mutations in the genes of isocitrate dehydrogenase (IDH) isoforms. In vivo measurement of 2‐HG in patients, using magnetic resonance spectroscopy (MRS), has largely been carried out at 3 T, yet signal overlap continues to pose a challenge for 2‐HG detection. To combat this, several groups have proposed MRS methods at ultra‐high field (≥7 T) where theoretical increases in signal‐to‐noise ratio and spectral resolution could improve 2‐HG detection. Long echo time (long‐TE) semi‐localization by adiabatic selective refocusing (semi‐LASER) (TE = 110 ms) is a promising method for improved 2‐HG detection in vivo at either 3 or 7 T owing to the use of broad‐band adiabatic localization. Using previously published semi‐LASER methods at 3 and 7 T, this study directly compares the detectability of 2‐HG in phantoms and in vivo across nine patients. Cramér–Rao lower bounds (CRLBs) of 2‐HG fitting were found to be significantly lower at 7 T (6 ± 2%) relative to 3 T (15 ± 7%) (p = 0.0019), yet were larger at 7 T in an IDH wild‐type patient. Although no increase in SNR was detected at 7 T (77 ± 26) relative to 3 T (77 ± 30), the detection of 2‐HG was greatly enhanced through an improved spectral profile and increased resolution at 7 T. 7 T had a large effect on pairwise fitting correlations between γ‐aminobutyric acid (GABA) and 2‐HG (p = 0.004), and resulted in smaller coefficients. The increased sensitivity for 2‐HG detection using long‐TE acquisition at 7 T may allow for more rapid estimation of 2‐HG (within a few spectral averages) together with other associated metabolic markers in glioma.     

Altered levels of the soluble IL-1, IL-4 and TNF receptors, as well as the IL-1 receptor antagonist, in intermittent allergic rhinitis

BACKGROUND: The effects of cytokines are modulated by soluble cytokine receptors (SCR) and receptor antagonists. Therefore, allergic disease may depend on altered proportions between cytokines, their SCR and receptor antagonists, rather than absolute changes in cytokine levels. Little is known about SCR in intermittent allergic rhinitis (IAR). OBJECTIVE: To examine the concentrations of SCR, i.e. sIL-1R2, sIL-4R, sIL-6R and sTNFR1, as well as the interleukin-1 receptor antagonist (IL-1Ra) in nasal fluids from allergen-challenged patients with IAR and healthy controls. METHODS: 30 patients with birch- or grass-pollen-induced IAR and 30 healthy controls were studied. In the patients nasal fluids were obtained before as well as 1 and 6 h after allergen provocation. RESULTS: Both symptom scores and rhinoscopic signs of rhinitis increased in the patients after allergen challenge. Comparisons between patients and controls showed that sIL-4R was lower in patients before and 1 and 6 h after provocation. IL-1Ra was lower before and 1 h after provocation. In addition, lower concentrations of sTNFR1 were found in patients after 1 h, while sIL-1R2 concentrations were higher after 1 h. Comparisons of patients before and after challenge showed that IL-1Ra and sTNFR1 decreased after 1 h, while sIL-1R2 increased. No significant differences were found compared to 6 h. sIL-6R did not significantly differ between the study groups. CONCLUSIONS: After allergen challenge, significant changes in the nasal fluid levels of IL-1Ra, sIL-1R2 and sTNFR1 were found. By contrast, sIL-4R remained at lower levels than in controls both before and after challenge. Since sIL-4R modulates IgE synthesis, this may play a role in the pathogenesis of IAR.     

Novel homozygous p.E64D mutation in DJ1 in early onset Parkinson disease (PARK7)

Mutations in the parkin gene have been identified as a common cause of autosomal recessive inherited Parkinson disease (PD) associated with early disease manifestation. However, based on linkage data, mutations in other genes contribute to the genetic heterogeneity of early-onset PD (EOPD). Recently, two mutations in the DJ1 gene were described as a second cause of autosomal recessive EOPD (PARK7). Analyzing the PARK7/DJ1 gene in 104 EOPD patients, we identified a third mutation, c.192G>C (p.E64D), associated with EOPD in a patient of Turkish ancestry and characterized the functional significance of this amino acid substitution. In the patient, a substantial reduction of dopamine uptake transporter (DAT) binding was found in the striatum using [(18)F]FP-CIT and PET, indicating a serious loss of presynaptic dopaminergic afferents. His sister, homozygous for E64D, was clinically unaffected but showed reduced dopamine uptake when compared with a clinically unaffected brother, who is heterozygous for E64D. We demonstrate by crystallography that the E64D mutation does not alter the structure of the DJ1 protein, however we observe a tendency towards decreased levels of the mutant protein when overexpressed in HEK293 or COS7 cells. Using immunocytochemistry in contrast to the homogenous nuclear and cytoplasmic staining in HEK293 cells overexpressing wild-type DJ1, about 5% of the cells expressing E64D and up to 80% of the cells expressing the recently described L166P mutation displayed a predominant nuclear localization of the mutant DJ1 protein.     

Identification of two nuclear import signals in the alpha-gene product ICP22 of herpes simplex virus 1

The herpes simplex virus 1 (HSV-1) infected cell protein 22 (ICP22) is a multifunctional viral regulator that localizes in the nucleus of infected cells. ICP22 is required for optimal virus replication in certain cell types and is subject to extensive posttranslational modification. To map the signals in ICP22 which mediate its efficient nuclear localization, we investigated the nuclear import of fusion proteins comprising various fragments of ICP22 fused to green fluorescent protein (GFP) or beta-galactosidase (beta-Gal). These data demonstrated that ICP22 contains two independent regions with nuclear localization signal (NLS) activity. NLS1 maps to ICP22 amino acid position 16-31 and closely resembles the classical bipartite NLS of the type originally identified in nucleoplasmin. In contrast, NLS2 maps to ICP22 amino acid position 118-131 and contains multiple critical basic residues. Furthermore, fusion of both NLSs to chimeric glutathione-S-transferase (GST)-GFP protein and subsequent cytoplasmic microinjection of the respective transport substrates allowed us to monitor nuclear import in real-time. These data demonstrated that both ICP22-derived NLSs mediated efficient nuclear import with identical kinetics, resulting in complete nuclear accumulation of the chimeric transport cargoes at approximately 30 min postinjection. Finally, our data provide new insights into the domain structure of the multifunctional alpha-gene product ICP22 of HSV-1.     

Dynamics of dissemination and outer surface protein expression of different European Borrelia burgdorferi sensu lato strains in artificially infected Ixodes ricinus nymphs

Unfed Ixodes ricinus nymphs were infected with eight different strains and clones of Borrelia afzelii and B. garinii by capillary feeding. Except one B. afzelii clone, all expressed OspC in culture. Tick midguts and salivary glands were investigated at different time intervals for the presence of borreliae and for OspA and OspC phenotypes by immunofluorescence with simultaneous staining of OspA and OspC with monoclonal antibodies. Both species were transmittable to I. ricinus. All OspC-expressing strains and clones were able to disseminate into the salivary glands. In contrast, the OspC-negative B. afzelii clone was not detectable in the salivary glands, an indication that OspC plays an important role in dissemination. OspA-positive borreliae prevailed in the midgut. OspC positives were more frequent in the salivary glands than in the midgut. Notably, simultaneously OspA- and OspC-negative borreliae were detected in both organs. Kinetics of dissemination varied with the strains. The OspC-positive B. afzelii clone and all B. garinii OspA type 4 strains were detectable in the salivary glands right after feeding, while one B. garinii OspA type 6 strain invaded the salivary glands with a delay of 24 h. These findings support the hypothesis that OspA is abundantly expressed in unfed ticks while upregulation of OspC is also a prerequisite for dissemination in the vector for the Eurasian species B. afzelii and B. garinii. However, we found strain-specific dynamics of Osp expression and strain-specific kinetics of systemic infection in the vector tick and it appears that additional factors are involved in the initiation and regulation of the dissemination process.     

Force feedback facilitates multisensory integration during robotic tool use

The present study investigated the effects of force feedback in relation to tool use on the multisensory integration of visuo-tactile information. Participants learned to control a robotic tool through a surgical robotic interface. Following tool-use training, participants performed a crossmodal congruency task, by responding to tactile vibrations applied to their hands, while ignoring visual distractors superimposed on the robotic tools. In the first experiment it was found that tool-use training with force feedback facilitates multisensory integration of signals from the tool, as reflected in a stronger crossmodal congruency effect with the force feedback training compared to training without force feedback and to no training. The second experiment extends these findings by showing that training with realistic online force feedback resulted in a stronger crossmodal congruency effect compared to training in which force feedback was delayed. The present study highlights the importance of haptic information for multisensory integration and extends findings from classical tool-use studies to the domain of robotic tools. We argue that such crossmodal congruency effects are an objective measure of robotic tool integration and propose some potential applications in surgical robotics, robotic tools, and human–tool interaction.     

Hepatoblastoma in a 4-year-old girl with Fanconi anaemia

CASE REPORT: Hepatoblastoma was diagnosed in a 4-year-old girl receiving growth hormone substitution therapy for short stature. Owing to multiple congenital malformations, VACTERL-H (vertebral, anal, cardiac, tracheal, renal and limb anomalies with hydrocephalus) association had been suggested. Elevated chromosomal breakage rates and G2 phase arrest induced by DNA-crosslinking agents in cellular assays confirmed the diagnosis of Fanconi anaemia (FA), a tumour susceptibility syndrome known to be associated with hepatocellular carcinoma following androgen therapy. Subsequent genotyping revealed biallelic mutations in the FANCD1/BRCA2 gene. CONCLUSION: We describe the first case of hepatoblastoma in a patient with FA to raise awareness of this tumour type in the close clinical observation of early cancer-prone forms of this condition, particularly in the presence of FANCD1/BRCA2 mutations. The present case also underscores the importance of FA testing in patients with VACTERL(-H).     

Sympatho-renal interactions in the determination of arterial pressure: role in hypertension

Renal mechanisms and the sympathetic nervous system contribute to the development of arterial hypertension. Renal transplantation experiments in spontaneously hypertensive rats (SHRs) were performed to investigate how the sympathetic nervous system and the kidneys interact during the development and maintenance of hypertension. Our findings indicate that the rise in arterial pressure that occurs after transplantation of a kidney from a SHR into normotensive recipients is not mediated by elevations in sympathetic activity. However, chronic reductions in sympathetic tone reduce the rise in arterial pressure which can be induced by SHR renal grafts in normotensive recipients. Untreated SHRs transplanted with a kidney from sympathectomized donors have lower arterial pressure and reduced sodium sensitivity of arterial pressure compared to SHRs transplanted with a kidney from hydralazine-treated donors. It is concluded that chronic non-adapting changes in sympathetic activity modulate the degree to which renal mechanisms can cause hypertension in SHRs. Severe reduction in sympathetic tone during early ontogeny causes long-term changes in renal function that mitigate hypertension development in SHRs even when the extrarenal neuro-hormonal environment is restored.