Effect of CHRFAM7A Δ2bp gene variant on secondary inflammation after spinal cord injury.

The α7 neuronal nicotinic acetylcholine receptors (α7nAChRs) are essential for anti-inflammatory responses. The human-specific CHRFAM7A gene and its 2bp deletion polymorphism (Δ2bp variant) encodes a structurally-deficient α7nAChRs that may impact the anti-inflammatory function. We studied 45 spinal cord injury (SCI) patients for up to six weeks post SCI to investigate the role of the Δ2bp variant on multiple circulating inflammatory mediators and two outcome measures (neuropathic pain and risk of pressure ulcers). The patient's SCI were classified as either severe or mild. Missing values were imputed. Overall genetic effect was conducted with independent sample t-test and corrected with false discovery rate (FDR). Univariate analysis and regression analysis were applied to evaluate the Δ2bp effects on temporal variation of inflammatory mediators post SCI and their interaction with outcome measures. In severe SCI, the Δ2bp carriers showed higher levels of circulating inflammatory mediators than the Δ2bp non-carriers in TNF-α (FDR = 9.6x10-4), IFN-γ (FDR = 1.3x10-3), IL-13 (FDR = 1.6x10-3), CCL11 (FDR = 2.1x10-3), IL-12p70 (FDR = 2.2x10-3), IL-8 (FDR = 2.2x10-3), CXCL10 (FDR = 3.1x10-3), CCL4 (FDR = 5.7x10-3), IL-12p40 (FDR = 7.1x10-3), IL-1b (FDR = 0.014), IL-15 (FDR = 0.024), and IL-2 (FDR = 0.037). IL-8 and CCL2 were negatively associated with days post injury (DPI) for the Δ2bp carriers (P = 2x10-7 and P = 2x10-8, respectively) and IL-5 was positively associated with DPI for the Δ2bp non-carriers (P = 0.015). Neuropathic pain was marginally positively associated with IL-13 for the Δ2bp carriers (P = 0.056). In mild SCI, the Δ2bp carriers had lower circulating levels of IL-15 (FDR = 0.04) than the Δ2bp non-carriers. Temporal variation of inflammatory mediators post SCI was not associated with the Δ2bp variant. For the mild SCI Δ2bp carriers, risk of pressure ulcers was positively associated with circulating levels of IFN-γ, CXCL10, and CCL4 and negatively associated with circulating levels of IL-12p70. These findings support an important role for the human-specific CHRFAM7A Δ2bp gene variant in modifying anti-inflammatory function of α7nAChRs following SCI.

Association of a Functional Polymorphism in the CHRFAM7A Gene with Inflammatory Response Mediators and Neuropathic Pain after Spinal Cord Injury.

The alpha 7 nicotinic acetylcholine receptor, α7 nAChR, plays a central role in regulating inflammatory responses. Previous studies showed that pharmacological inhibitors of α7nAChR have a pro-inflammatory effect, increasing the circulating levels of cytokines such as tumor necrosis factor alpha (TNFα). This study focused on how genetic polymorphisms of the partially duplicated α7nAChR gene (CHRFAM7A), which is highly expressed in peripheral blood cells, contribute to functional outcome after spinal cord injury (SCI). In a cohort of 27 SCI patients and 25 emergency room consented controls (% F/M: 15/85, 24/76; mean ± SE age: 35 ± 1.38 and 35 ± 2.0 respectively), a panel of circulating cytokines, noradrenergic metabolite (normetanephrine [NMN]) levels, and clinical data were available within the first 7 days post-injury (DPI) up to 90 DPI, and were investigated in the acute/subacute (DPI 1-21) and intermediate (DPI 22-90) temporal periods. Cytokine and NMN plasma levels on different DPI were analyzed as a function of CHRFAM7A genotype. TNFα levels, as a representative of some elevated inflammatory mediators, were nearly threefold higher in individuals carrying the del-2bp variant of the CHRFAM7A gene compared with that in the no-deletion genotype (p = 0.001 analysis of variance [ANOVA]) 3 weeks DPI, and twofold higher than genotype-matched acute/subacute non-SCI injury controls within 7 days DPI. In contrast, NMN levels were initially unchanged, although after 3 weeks, NMN levels were significantly decreased in SCI individuals carrying the del-2bp variant compared with non-carriers (p = 0.011 ANOVA). Numerical pain scores over this same period post-injury were significantly elevated in SCI patients carrying the del-2bp variant relative to non-carriers (p = 0.001 ANOVA). Taken together, these data reveal that pro-inflammatory responses associated with CHRFAM7A gene variation may also be associated with differences in pain experience in patients following SCI, at least during the intermediate phase.

Statistical-thermodynamic model for light scattering from eye lens protein mixtures.

We model light-scattering cross sections of concentrated aqueous mixtures of the bovine eye lens proteins γB- and α-crystallin by adapting a statistical-thermodynamic model of mixtures of spheres with short-range attractions. The model reproduces measured static light scattering cross sections, or Rayleigh ratios, of γB-α mixtures from dilute concentrations where light scattering intensity depends on molecular weights and virial coefficients, to realistically high concentration protein mixtures like those of the lens. The model relates γB-γB and γB-α attraction strengths and the γB-α size ratio to the free energy curvatures that set light scattering efficiency in tandem with protein refractive index increments. The model includes (i) hard-sphere α-α interactions, which create short-range order and transparency at high protein concentrations, (ii) short-range attractive plus hard-core γ-γ interactions, which produce intense light scattering and liquid-liquid phase separation in aqueous γ-crystallin solutions, and (iii) short-range attractive plus hard-core γ-α interactions, which strongly influence highly non-additive light scattering and phase separation in concentrated γ-α mixtures. The model reveals a new lens transparency mechanism, that prominent equilibrium composition fluctuations can be perpendicular to the refractive index gradient. The model reproduces the concave-up dependence of the Rayleigh ratio on α/γ composition at high concentrations, its concave-down nature at intermediate concentrations, non-monotonic dependence of light scattering on γ-α attraction strength, and more intricate, temperature-dependent features. We analytically compute the mixed virial series for light scattering efficiency through third order for the sticky-sphere mixture, and find that the full model represents the available light scattering data at concentrations several times those where the second and third mixed virial contributions fail. The model indicates that increased γ-γ attraction can raise γ-α mixture light scattering far more than it does for solutions of γ-crystallin alone, and can produce marked turbidity tens of degrees celsius above liquid-liquid separation.

Model for screened, charge-regulated electrostatics of an eye lens protein: Bovine gammaB-crystallin.

We model screened, site-specific charge regulation of the eye lens protein bovine gammaB-crystallin (γB) and study the probability distributions of its proton occupancy patterns. Using a simplified dielectric model, we solve the linearized Poisson-Boltzmann equation to calculate a 54×54 work-of-charging matrix, each entry being the modeled voltage at a given titratable site, due to an elementary charge at another site. The matrix quantifies interactions within patches of sites, including γB charge pairs. We model intrinsic pK values that would occur hypothetically in the absence of other charges, with use of experimental data on the dependence of pK values on aqueous solution conditions, the dielectric model, and literature values. We use Monte Carlo simulations to calculate a model grand-canonical partition function that incorporates both the work-of-charging and the intrinsic pK values for isolated γB molecules and we calculate the probabilities of leading proton occupancy configurations, for 4

Embolic Stroke: A Rare but Probably Real Cause of Aneurysmal-Like Subarachnoid Hemorrhage.

BACKGROUND: Ischemic stroke is being increasingly recognized as a possible cause of spontaneous isolated convexity subarachnoid hemorrhage (SAH). However, it is a much less established cause of cisternal, aneurysmal-like SAH. Only 3 case reports of concomitant cisternal SAH and perforator infarcts exist in the literature, raising the possibility of perforating artery rupture as a potential mechanism. In contrast, embolic stroke is not recognized as a cause of aneurysmal-like SAH. CASE DESCRIPTION: In 2 patients with embolic cerebral infarctions mimicking intracranial aneurysm rupture, diagnosis was confirmed by magnetic resonance imaging with diffusion-weighted imaging after cerebral angiography failed to reveal an underlying vascular lesion. Extracranial atherosclerosis was identified as the source of emboli in each case. One patient was started on antiplatelet therapy, and the other underwent surgical revascularization. Both patients had a favorable hospital course, with no recurrent hemorrhage or ischemia. CONCLUSIONS: Based on these observations, embolic stroke should be included in the differential diagnosis of angiogram-negative SAH. Therefore, brain magnetic resonance imaging and vascular imaging of the neck should be part of the routine work-up of this relatively common entity.

Cantilever TLIF with structural allograft and RhBMP2 for correction and maintenance of segmental sagittal lordosis: long-term clinical, radiographic, and functional outcome.

STUDY DESIGN/SETTING: Prospective cohort study in a tertiary care spine center. OBJECTIVE: The effectiveness of the cantilever transforaminal lumbar interbody fusion (C-TLIF) technique in creating and maintaining lordosis, avoiding nerve problems, and obtaining fusion was studied. SUMMARY OF BACKGROUND DATA: C-TLIF is a microscope-assisted transforaminal lumbar interbody fusion technique, emphasizing no dural retraction with placement of structural allograft and RhBMP2 anteriorly under the cortical apophyseal ring, followed by middle column cancellous autograft placed under compression with posterior pedicle spinal instrumentation. METHODS: A total of 100 consecutive patients studied with an average of 30 months of follow-up. A total of 48 had prior surgery at the index level; 16 had the procedure done at an adjacent level to a previous fusion; 32 at L5-S1 with 42 at L4-L5 and 26 at L3-L4. There were 76 single-level and 24 two-level fusions. One patient was a smoker with one other patient a compensation case. Outcome was prospectively documented with self-administered Visual Analog Pain Scale, Oswestry Disability Questionnaire, Treatment Intensity Questionnaire, and SF-36 Health Survey. Patients rated the surgery as excellent, good, fair, or poor and whether they would recommend the surgery. Student t test was used for statistical analysis with significance set at P = 0.05. RESULTS: Blood loss and hospital stay averaged 300 mL and 2.2 days, respectively. There was significant reduction (P < 0.05) in pain scores from 9 to 3, Oswestry Disability Index scores from 35 to 12, and Treatment Intensity Score from 21/25 to 2/25 at final follow-up. The SF-36 PCS and MCS scores showed an increasing trend to improvement. A total of 69 rated the surgery as excellent, 23 good, 7 fair, and 1 poor. A total of 97% were satisfied and would recommend the surgery. All had improvement in radicular pain with no dural tears, neural injury, or neuropathic pain. There was significant improvement (P < 0.05) in segmental sagittal lordosis from 2 degrees to 9 degrees, anterior disc height from 6 to 14 mm, and posterior disc height from 4 to 8 mm. There was no subsidence, misplaced screws, or instrumentation failure. Solid fusion was obtained in 99 of 100 patients. CONCLUSIONS: The C-TLIF allows for creation and maintenance of sagittal lordosis while avoiding subsidence and neurologic problems with a 99% fusion rate and 97% patient satisfaction.

Surface properties, more than size, limiting convective distribution of virus-sized particles and viruses in the central nervous system.

OBJECT: Achieving distribution of gene-carrying vectors is a major barrier to the clinical application of gene therapy. Because of the blood-brain barrier, the distribution of genetic vectors to the central nervous system (CNS) is even more challenging than delivery to other tissues. Direct intraparenchymal microinfusion, a minimally invasive technique, uses bulk flow (convection) to distribute suspensions of macromolecules widely through the extracellular space (convection-enhanced delivery [CED]). Although acute injection into solid tissue is often used for delivery of oligonucleotides, viruses, and liposomes, and there is preliminary evidence that certain of these large particles can spread through the interstitial space of the brain by the use of convection, the use of CED for distribution of viruses in the brain has not been systematically examined. That is the goal of this study. METHODS: Investigators used a rodent model to examine the influence of size, osmolarity of buffering solutions, and surface coating on the volumetric distribution of virus-sized nanoparticles and viruses (adeno-associated viruses and adenoviruses) in the gray matter of the brain. The results demonstrate that channels in the extracellular space of gray matter in the brain are large enough to accommodate virus-sized particles and that the surface characteristics are critical determinants for distribution of viruses in the brain by convection. CONCLUSIONS: These results indicate that convective distribution can be used to distribute therapeutic viral vectors in the CNS.

Management of CNS mucormycosis in the pediatric patient.

Rhinocerebral mucormycosis (RM) is a rare, rapidly progressive disorder caused by fungi from the Mucoraceae family. With extensive central nervous system involvement, this disease is uniformly fatal within weeks. Mucormycosis normally presents in poorly controlled diabetics, intravenous drug abusers and immunocompromised patients. Many have advocated radical surgical resection (i.e. exenteration of the cavernous sinus with carotid sacrifice and en bloc resection) with administration of amphotericin B. We present a case of mucormycosis involving the paranasal sinuses and cranial base in a pediatric patient who experienced long-term survival with a more limited resection. We also present a review of the relevant literature. A 14-year-old diabetic male presented with RM with involvement of the bilateral frontal lobes, right basal ganglia and temporal lobe. Additionally, there was involvement of the sphenoid sinus and right cavernous sinus with extension into the posterior fossa along the course of the trigeminal nerve and encasement with narrowing of the right carotid artery. The patient underwent sinus endoscopy with debridement of necrotic fungal tissue and bone. This was followed by craniotomy with evacuation of bifrontal, right temporal and basal ganglia abscesses in such a way that all abscess cavities communicated. An Ommaya reservoir was placed into the largest cavity. The patient continued to receive intrathecal and intravenous antibiotics as well as hyperbaric oxygen therapy. The patient was clinically and radiographically free of disease 1 year after diagnosis. While invasive RM is generally a fatal disease, this rare disorder can be treated successfully without radical resection, particularly if multimodality treatment options are implemented.