Step trajectory analysis of spinal cord injured rats trained with neuromuscular electrical stimulation coordinated with robotic treadmill training

Applying neuromuscular electrical stimulation (NMES) during treadmill training (TT) has been shown to improve functional outcomes, such as gait speed and walking distance, in spinal cord injury (SCI) patients. However, ways to improve this combined NMES+TT therapy have not been investigated. We have developed NMES system for a rodent model of SCI to investigate whether and how more precisely timing the stimulation to robotically assisted hindlimb position might achieve rehabilitation of independent stepping after SCI. In our therapy (NMES+RTT), rodent ankle flexor muscles are stimulated while the hindlimbs are robotically driven through pre-programmed trajectories during treadmill training. The objectives of the work presented here were to quantify changes in step trajectory resulting from our combined NMES+RTT therapy and compare those effects with those induced by robotic treadmill training (RTT) alone. Animals were spinally contused to model severe SCI, and either received 2 weeks of NMES+RTT followed by 2 weeks of RTT (n=6) or 2 weeks of RTT followed by 2 weeks of NMES+RTT (n=7). Changes in step trajectories after training were analyzed. According to a deviation measure we developed, the step trajectories improved after either NMES+RTT or RTT training but more closely matched the desired pre-programmed trajectories after NMES+RTT than after RTT only. The step trajectories are also more consistent, as indicated by a coefficient of variation measure, after training and more so after NMES+RTT than after RTT only. These preliminary results from our NMES+RTT vs. RTT study are consistent with the hypothesis that appropriately timing NMES with hindlimb movements during stepping is an effective therapy for restoring the ability to step after spinal cord injury.

Enhanced photoluminescence and characterization of multicolor carbon dots using plant soot as a carbon source

Carbon dots (C-dots) are a class of novel fluorescent nanomaterials, which have drawn great attention for their potential applications in bio-nanotechnology. Multicolor C-dots have been synthesized by chemical nitric acid oxidation using the reproducible plant soot as raw material. TEM analysis reveals that the prepared C-dots have an average size of 3.1 nm. The C-dots are well dispersed in aqueous solution and are strongly fluorescent under the irradiation of ultra-violet light. X-ray photoelectron spectroscopy characterization demonstrates that the O/C atomic ratio for C-dots change to from 0.207 to 0.436 due to the chemical oxidation process. The photo bleaching experiment reveals that the C-dots show excellent photostability as compared with the conventional organic dyes, fluorescein and rhodamine B. The fluorescence intensity of the C-dots did not change significantly in the pH range of 3-10. To further enhance the fluorescence quantum yield, the C-dots were surface modified with four types of passivation ligands, 4,7,10-trioxa-1,13-tridecanediamine (TTDDA), poly-L-lysine (PLL), cysteine and chitosan and the fluorescence quantum yields of the TTDDA, PLL, cysteine and chitosan passivated C-dots were improved 1.53-, 5.94-, 2.00- and 3.68-fold, respectively. Fourier-transform infrared (FTIR) spectra were employed to characterize the surface groups of the C-dots. The bio-application of the C-dots as fluorescent bio-probes was evaluated in cell imaging and ex vivo fish imaging, which suggests that the C-dots may have potential applications in biolabeling and bioimaging.

Probiotics in luminal gastroenterology: the current state of play

In recent years, there has been a growing interest in the use of probiotics in various areas of gastrointestinal (GI) health. Probiotics are defined as live microorganisms that provide beneficial health effects on the host when administered in adequate amounts. Various probiotics have been shown to suppress bacterial growth, modulate the immune system and improve intestinal barrier function. However, despite several studies with promising results, most trials are small and many have substantial methodological limitations. However, with better targeting and appropriate randomised controlled trials, this area may soon yield important therapeutic strategies to optimise GI health. Here, we review the current knowledge of probiotics of relevance to luminal GI health.

General practitioners' knowledge of and attitudes to inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic disease requiring long-term management. General practitioners (GPs) are often the first point of contact for initial symptoms and flares. Thus we assessed GPs' attitudes to and knowledge of IBD.

METHODS

A state-wide postal survey of GPs was performed collecting demographic details, practice and attitudes in IBD-specific management and knowledge.

RESULTS

Of 1800 GPs surveyed in South Australia, 409 responded; 58% were male, 80% Australian trained and 73% practised in metropolitan areas. Most GPs (92%) reported seeing zero to five IBD patients per month. Overall, 37% of the GPs reported being generally 'uncomfortable' with IBD management. Specifically, they were only somewhat comfortable in providing/using maintenance therapy, steroid therapy or unspecified therapy for an acute flare. They were uncomfortable with the use of immunomodulators and biologicals (71 and 91% respectively). No GP reported never referring, referring sometimes (12%), often (34%) or always (55%). Most (87%) GPs rated their communication with private specialists positively; while only 32% were satisfied with support from public hospitals. Of concern, most (70%) monitored patients on immunosuppression on a case-by-case basis rather than by protocol. In multivariable analyses, GPs' IBD-specific knowledge did not influence comfort with overall management, nor did knowledge influence GP comfort with any particular therapy.

CONCLUSION

Individual GPs care for few IBD patients and have variable attitudes in their practice. Whether improvement can realistically be achieved given individual GP's paucity of patients is questionable. These data support the provision of better support and specific action plans for IBD patients.

Synthesis and evaluation of a targeted nanoglobular dual-modal imaging agent for MR imaging and image-guided surgery of prostate cancer

PURPOSE

To synthesize and evaluate a peptide targeted nanoglobular dual modal imaging agent specific to a cancer biomarker in tumor stroma for MRI and fluorescence visualization of prostate tumor in image-guided surgery.

METHODS

A peptide (CGLIIQKNEC, CLT1) targeted generation 2 nanoglobular (polylysine dendrimer with a silsesquioxane core) dual modal imaging agent, CLT1-G2-(Gd-DOTA-MA)-Cy5, was synthesized by stepwise conjugation of Gd-DOTA-MA, Cy5 and peptide to the dendrimer. Contrast enhanced MR imaging of the targeted dual imaging agent was evaluated on a Bruker 7T animal scanner with male athymic nude mice bearing orthotopic PC3-GFP prostate tumor. Fluorescence tumor imaging of the agent was carried out on a Maestro fluorescence imaging system.

RESULTS

The targeted agent CLT1-G2-(Gd-DOTA-MA)-Cy5 produced greater contrast enhancement in the tumor tissue than the control agent KAREC-G2-(Gd-DOTA-MA)-Cy5 at a dose of 30 μmol-Gd/kg in the MR images of the tumor bearing mice. Signal-to-noise ratio (SNR) of CLT1-G2-(Gd-DOTA-MA)-Cy5 in the tumor tissue was approximately 2 fold of that of the control agent in the first 15 min post-injection. The targeted agent also resulted in bright fluorescence signals in the tumor tissue.

CONCLUSION

The CLT1 peptide targeted nanoglobular dual-imaging agent CLT1-G2-(Gd-DOTA-MA)-Cy5 has a potential for MRI and fluorescence visualization of prostate tumor.

Comparison between cartilage and fascia grafts in type 1 tympanoplasty

OBJECTIVES

We retrospectively analysed long-term hearing results and graft take rates in our cases with both temporalis muscle fascia and the cartilage island technique.

METHODOLOGY

Between September 2000 and October 2011, a total of 489 patients underwent cartilage tympanoplasty, while 318 patients had tympanoplasty using fascia. In this study we included patients with a follow-up period of at least 3 years. Exclusion criteria were ossicular chain defects, cholesteatoma, otorrhoea, middle ear granulation or effusion, and a history of middle ear surgery.

RESULTS

The cartilage group consisted of 49 patients, with 28 patients being included in the fascia group. Both air conduction hearing thresholds and air bone gaps improved significantly in both groups. However, no statistical significance was found between the results for the two groups (p > 0.05).

CONCLUSION

Our study concurs with many others in the literature, clearly indicating that cartilage produces hearing results that are comparable to temporalis muscle fascia grafts.

Electroacupuncture alleviates affective pain in an inflammatory pain rat model

Pain has both sensory-discriminative and emotional-affective dimensions. Previous studies demonstrate that electroacupuncture (EA) alleviates the sensory dimension but do not address the affective. An inflammatory pain rat model, produced by a complete Freund adjuvant (CFA) injection into the hind paw, was combined with a conditioned place avoidance (CPA) test to determine whether EA inhibits spontaneous pain-induced affective response and, if so, to study the possibility that rostral anterior cingulate cortex (rACC) opioids underlie this effect. Male Sprague-Dawley rats (250-275 g, Harlan) were used. The rats showed place aversion (i.e. affective pain) by spending less time in a pain-paired compartment after conditioning than during a preconditioning test. Systemic non-analgesic morphine (0.5 and 1.0 mg/kg, i.p.) inhibited the affective reaction, suggesting that the affective dimension is underpinned by mechanisms different from those of the sensory dimension of pain. Morphine at 0.5 and at 1 mg/kg did not induce reward. Rats given EA treatment before pain-paired conditioning at GB 30 showed no aversion to the pain-paired compartment, indicating that EA inhibited the affective dimension. EA treatment did not produce reward or aversive effect. Intra-rACC administration of D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr amide (CTOP), a selective mu opioid receptor antagonist, but not norbinaltorphimine (nor-BNI), a selective kappa opioid receptor antagonist, blocked EA inhibition of the affective dimension. These data demonstrate that EA activates opioid receptors in the rACC to inhibit pain-induced affective responses and that EA may be an effective therapy for both the sensory-discriminative and the affective dimensions of pain.

Single cell molecular recognition of migrating and invading tumor cells using a targeted fluorescent probe to receptor PTPmu

Detection of an extracellular cleaved fragment of a cell-cell adhesion molecule represents a new paradigm in molecular recognition and imaging of tumors. We previously demonstrated that probes that recognize the cleaved extracellular domain of receptor protein tyrosine phosphatase mu (PTPmu) label human glioblastoma brain tumor sections and the main tumor mass of intracranial xenograft gliomas. In this article, we examine whether one of these probes, SBK2, can label dispersed glioma cells that are no longer connected to the main tumor mass. Live mice with highly dispersive glioma tumors were injected intravenously with the fluorescent PTPmu probe to test the ability of the probe to label the dispersive glioma cells in vivo. Analysis was performed using a unique three-dimensional (3D) cryo-imaging technique to reveal highly migratory and invasive glioma cell dispersal within the brain and the extent of colabeling by the PTPmu probe. The PTPmu probe labeled the main tumor site and dispersed cells up to 3.5 mm away. The cryo-images of tumors labeled with the PTPmu probe provide a novel, high-resolution view of molecular tumor recognition, with excellent 3D detail regarding the pathways of tumor cell migration. Our data demonstrate that the PTPmu probe recognizes distant tumor cells even in parts of the brain where the blood-brain barrier is likely intact. The PTPmu probe has potential translational significance for recognizing tumor cells to facilitate molecular imaging, a more complete tumor resection and to serve as a molecular targeting agent to deliver chemotherapeutics to the main tumor mass and distant dispersive tumor cells.

Development of functionalized terbium fluorescent nanoparticles for antibody labeling and time-resolved fluoroimmunoassay application

Silica-based functionalized terbium fluorescent nanoparticles were prepared, characterized and developed as a fluorescence probe for antibody labeling and time-resolved fluoroimmunoassay. The nanoparticles were prepared in a water-in-oil (W/O) microemulsion containing a strongly fluorescent Tb(3+) chelate, N,N,N(1),N(1)-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)phenylpyridine] tetrakis(acetate)-Tb(3+) (BPTA-Tb(3+)), Triton X-100, octanol, and cyclohexane by controlling copolymerization of tetraethyl orthosilicate (TEOS) and 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (AEPS) with ammonia water. The characterizations by transmission electron microscopy and fluorometric methods show that the nanoparticles are spherical and uniform in size, 45 +/- 3nm in diameter, strongly fluorescent with fluorescence quantum yield of 10% and a long fluorescence lifetime of 2.0ms. The amino groups directly introduced to the nanoparticle's surface by using AEPS in the preparation made the surface modification and bioconjugation of the nanoparticles easier. The nanoparticle-labeled anti-human alpha-fetoprotein antibody was prepared and used for time-resolved fluoroimmunoassay of alpha-fetoprotein (AFP) in human serum samples. The assay response is linear from 0.10ngml(-1) to about 100ngml(-1) with the detection limit of 0.10ngml(-1). The coefficient variations (CVs) of the method are less than 9.0%, and the recoveries are in the range of 84-98% for human serum sample measurements.

Enhancement of surface graft density of MPEG on alginate/chitosan hydrogel microcapsules for protein repellency

Alginate/chitosan/alginate (ACA) hydrogel microcapsules were modified with methoxy poly(ethylene glycol) (MPEG) to improve protein repellency and biocompatibility. Increased MPEG surface graft density (n(S)) on hydrogel microcapsules was achieved by controlling the grafting parameters including the buffer layer substrate, membrane thickness, and grafting method. X-ray photoelectron spectroscopy (XPS) model was employed to quantitatively analyze n(S) on this three-dimensional (3D) hydrogel network structure. Our results indicated that neutralizing with alginate, increasing membrane thickness, and in situ covalent grafting could increase n(S) effectively. ACAC(PEG) was more promising than ACC(PEG) in protein repellency because alginate supplied more -COO(-) negative binding sites and prevented MPEG from diffusing. The n(S) increased with membrane thickness, showing better protein repellency. Moreover, the in situ covalent grafting provided an effective way to enhance n(S), and 1.00 ± 0.03 chains/nm(2) was achieved, exhibiting almost complete immunity to protein adsorption. This antifouling hydrogel biomaterial is expected to be useful in transplantation in vivo.

Interobserver reliability of compression ultrasound for residual thrombosis after first unprovoked deep vein thrombosis

BACKGROUND

Accurate assessment of residual thrombosis is of clinical importance for diagnostic baseline imaging, and may be of value in risk stratification for recurrent venous thromboembolism (VTE). This study evaluated the interobserver reliability of the measurement of residual thrombosis in patients 6 months after a first unprovoked deep vein thrombosis (DVT) of the leg.

PATIENTS/METHODS

All enrolled patients received two ultrasound examinations by two independent blinded ultrasound technicians 5-7 months after their first unprovoked DVT. In total, 49 patients completed the two baseline ultrasound examinations. During the examinations, the presence of residual thrombosis was evaluated. If residual thrombosis was present, a detailed description of the size and location was reported. After all ultrasound results had been collected, the interobserver agreement was calculated by use of the kappa statistics, Pearson correlation, and the Bland-Altman plot. Furthermore, the clinical implications of interobserver reliability were examined.

RESULTS

The interobserver reliability of the assessment of whether residual thrombosis is present was very good (κ = 0.92). The interobserver reliability of the measurement of residual thrombosis was good (r2 = 0.648), with a limited number of patients being misclassified. For the assessment of the percentage of residual occlusion, the interobserver reliability was fair (r2 = 0.357).

CONCLUSIONS

Our results suggest that the interobserver reliability for measurement of residual thrombosis is high, and that the variability introduced by interobserver reliability has minimal clinical implications. Our study is important for the use of baseline imaging for the diagnostic and prognostic management of recurrent VTE.

Synthesis and evaluation of a peptide targeted small molecular Gd-DOTA monoamide conjugate for MR molecular imaging of prostate cancer

Tumor extracellular matrix has an abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. Innovative design and development of safe and effective targeted contrast agents to these biomarkers would allow effective MR cancer molecular imaging with high spatial resolution. In this study, we synthesized a low molecular weight CLT1 peptide targeted Gd(III) chelate CLT1-dL-(Gd-DOTA)(4) specific to clotted plasma proteins in tumor stroma for cancer MR molecular imaging. CLT1-dL-(Gd-DOTA)(4) was synthesized by conjugating four Gd-DOTA monoamide chelates to a CLT1 peptide via generation 1 lysine dendrimer. The T(1) relaxivity of CLT1-dL-(Gd-DOTA)(4) was 40.4 mM(-1) s(-1) per molecule (10.1 mM(-1) s(-1) per Gd) at 37 °C and 1.5 T. Fluorescence imaging showed high binding specificity of CLT1 to orthotopic PC3 prostate tumor in mice. The contrast agent resulted in improved tumor contrast enhancement in male athymic nude mice bearing orthotopic PC3 prostate tumor xenograft at a dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for high-resolution MR molecular imaging of prostate tumor.

Electroacupuncture inhibition of hyperalgesia in an inflammatory pain rat model: involvement of distinct spinal serotonin and norepinephrine receptor subtypes

BACKGROUND

Although acupuncture analgesia is well documented, its mechanisms have not been thoroughly clarified. We previously showed that electroacupuncture (EA) activates supraspinal serotonin- and norepinephrine-containing neurones that project to the spinal cord. This study investigates the involvement of spinal alpha(2)-adrenoceptors (α2-ARs) and 5-hydroxytryptamine (serotonin) receptors (5-HTRs) in EA effects on an inflammatory pain rat model.

METHODS

Inflammatory hyperalgesia was induced by injecting complete Freund's adjuvant (CFA, 0.08 ml) into the plantar surface of one hind paw and assessed by paw withdrawal latency (PWL) to a noxious thermal stimulus. The selective α2a-AR antagonist BRL-44408, α2b-AR antagonist imiloxan hydrochloride, 5-HT2B receptor (5-HT2BR) antagonist SB204741, 5-HT3R antagonist LY278584, or 5-HT1AR antagonists NAN-190 hydrobromide, or WAY-100635 were intrathecally administered 20 min before EA or sham EA, which was given 2 h post-CFA at acupoint GB30.

RESULTS

EA significantly increased PWL compared with sham [7.20 (0.46) vs 5.20 (0.43) s]. Pretreatment with α2a-AR [5.35 (0.45) s] or 5-HT1AR [5.22 (0.38) s] antagonists blocked EA-produced anti-hyperalgesia; α2b-AR, 5-HT2BR, and 5-HT3R antagonist pretreatment did not. Sham plus these antagonists did not significantly change PWL compared with sham plus vehicle, indicating that the antagonists had little effect on PWL. Immunohistochemical staining demonstrated that α2a-ARs are on primary afferents and 5-HT1ARs are localized in N-methyl-d-aspartic acid (NMDA) subunit NR1-containing neurones in the spinal dorsal horn.

CONCLUSIONS

The data show that α2a-ARs and 5-HT1ARs are involved in the EA inhibition of inflammatory pain and that the NMDA receptors are involved in EA action.