Ultrasound Evaluation and Guided Injection of the Subscapularis and Serratus Anterior Muscles Between the Scapula and the Thoracic Cage: A Technical Note.

Most subscapularis and serratus anterior muscles lie between the scapula and the thoracic cage. Evaluation of this area in patients with scapulothoracic dyskinesis, snapping scapular syndrome, or interscapular pain can provide valuable information to clinicians. However, ultrasound scanning of pathologies in this area is hindered by anatomical limitations. In this study, we described a simple patient setup position and scanning method for ultrasound evaluation and guided intervention of the subscapularis and serratus anterior muscles between the scapula and thoracic cage.

Volume Effect of Nerve Hydrodissection for Carpal Tunnel Syndrome: A Prospective, Randomized, and Single-Blind Study.

OBJECTIVES: This study compared ultrasound-guided nerve hydrodissection (HD) outcomes using two commonly used injectate volumes (10 and 5 mL) of normal saline to explore if there is a volume effect of HD for patients with moderate carpal tunnel syndrome (CTS). METHODS: Twenty-four participants were randomly assigned to treatment with HD using ultrasound-guidance and either 10 mL or 5 mL of normal saline (HD-10 and HD-5 groups respectively). Our primary outcome measures were the change scores of the two subscales of the Boston Carpal Tunnel Syndrome Questionnaire: The Symptom Severity Scale (SSS) and Functional Status Scale (FSS). We conducted a one-way repeated analysis of variance for 3 time points (4, 12, and 24 weeks) for both SSS and FSS, respectively, for change scores from time 0, and percentage change from time 0. RESULTS: All participants (n = 12 per group) completed the study. From 0 to 24 weeks the HD-10 group outperformed the HD-5 group for improvement in SSS (median ± IQR; -0.8 ± 0.4 versus -0.5 ± 0.5; P = .024) and FSS scores (mean ± SD; -0.8 ± 0.2 versus -0.5 ± 0.5; P = .011). The HD-10 group improvement in FSS subtest significantly exceeded the MCID percentage-change-based threshold of 27% (34%; P = .039). CONCLUSIONS: Despite the limitations of small study size, a largely inert injectate, and a single injection approach, these findings in favor of the 10 mL group suggest that the volume used for ultrasound-guided HD in moderate CTS matters, and a higher volume is more effective.

Niche differentiation in the light spectrum promotes coexistence of phytoplankton species: a spatial modelling approach.

The paradox of the plankton highlights the apparent contradiction between Gause's law of competitive exclusion and the observed diversity of phytoplankton. It is well known that phytoplankton dynamics depend heavily on light availability. Here we treat light as a continuum of resources rather than a single resource by considering the visible light spectrum. We propose a spatially explicit reaction-diffusion-advection model to explore under what circumstance coexistence is possible from mathematical and biological perspectives. Furthermore, we provide biological context as to when coexistence is expected based on the degree of niche differentiation within the light spectrum and overall turbidity of the water.

Front propagation in the shadow wave-pinning model.

In this paper we consider a non-local bistable reaction-diffusion equation which is a simplified version of the wave-pinning model of cell polarization. In the small diffusion limit, a typical solution u(x, t) of this model approaches one of the stable states of the bistable nonlinearity in different parts of the spatial domain [Formula: see text], separated by an interface moving at a normal velocity regulated by the integral [Formula: see text]. In what is often referred to as wave-pinning, feedback between mass-conservation and bistablity causes the interface to slow and approach a fixed limit. In the limit of a small diffusivity [Formula: see text], we prove that for any [Formula: see text] the interface can be estimated within [Formula: see text] of the location as predicted using formal asymptotics. We also discuss the sharpness of our result by comparing the formal asymptotic results with numerical simulations.

Directed movement changes coexistence outcomes in heterogeneous environments.

Understanding mechanisms of coexistence is a central topic in ecology. Mathematical analysis of models of competition between two identical species moving at different rates of symmetric diffusion in heterogeneous environments show that the slower mover excludes the faster one. The models have not been tested empirically and lack inclusions of a component of directed movement toward favourable areas. To address these gaps, we extended previous theory by explicitly including exploitable resource dynamics and directed movement. We tested the mathematical results experimentally using laboratory populations of the nematode worm, Caenorhabditis elegans. Our results not only support the previous theory that the species diffusing at a slower rate prevails in heterogeneous environments but also reveal that moderate levels of a directed movement component on top of the diffusive movement allow species to coexist. Our results broaden the theory of species coexistence in heterogeneous space and provide empirical confirmation of the mathematical predictions.

The Long-Term Analgesic Effectiveness of Platelet-Rich Plasma Injection for Carpal Tunnel Syndrome: A Cross-Sectional Cohort Study.

OBJECTIVE: Interest in perineural platelet-rich-plasma (PRP) injections for the treatment of carpal tunnel syndrome (CTS) has increased in recent years. However, evidence supporting the long-term effectiveness of PRP is lacking. Therefore, the aim of our cross-sectional cohort study was to investigate the long-term results of PRP injections for CTS. METHODS: Eighty-one patients diagnosed with CTS of any grade who received a single PRP injection at least 2 years prior were enrolled. Through structured telephone interviews, all patients were asked of their post-injection outcomes compared to their pre-injection condition. Symptom relief ≥50%, compared to the pre-injection condition, was considered an effective outcome. Binary logistic regression was applied to analyze each baseline variable as a regressor for determining the prognostic outcome factors. RESULTS: In total, 70% of patients reported positive outcomes ≥2 years post-injection. Shorter duration of symptoms before treatment (odds ratio: 0.991; 95% confidence interval [CI] 0.983-0.999; P = .023) and lower electrodiagnostic severity of CTS were the main prognostic factors for an effective outcome (mild grade vs severe grade, odds ratio: 17.652; 95% CI 1.43-221.1; P = .025). Although there was a trend toward positive outcomes at longer follow-up durations (2-3 years vs 3-4 years vs 4-5 years), the difference was not statistically significant. CONCLUSIONS: A single perineural PRP injection has a long-term analgesic effect on CTS, especially in mild-to-moderate cases.

A cancer model with nonlocal free boundary dynamics.

Cancer cells at the tumor boundary move in the direction of the oxygen gradient, while cancer cells far within the tumor are in a necrotic state. This paper introduces a simple mathematical model that accounts for these facts. The model consists of cancer cells, cytotoxic T cells, and oxygen satisfying a system of partial differential equations. Some of the model parameters represent the effect of anti-cancer drugs. The tumor boundary is a free boundary whose dynamics is determined by the movement of cancer cells at the boundary. The model is simulated for radially symmetric and axially symmetric tumors, and it is shown that the tumor may increase or decrease in size, depending on the "strength" of the drugs. Existence theorems are proved, global in-time in the radially symmetric case, and local in-time for any shape of tumor. In the radially symmetric case, it is proved, under different conditions, that the tumor may shrink monotonically, or expand monotonically.

Ultrasound-guided L5/S1 intradiscal needle placement using biplanar approach with the patient in the lateral decubitus position: A report of three cases.

BACKGROUND: The use of ultrasound (US)-guided intradiscal injection has been described in the literature with the patient lying in the prone position; however, many patients are unable to lie in the prone position. Therefore, we describe an innovative technique of US-guided platelet-rich plasma (PRP) administration in the lumbar intervertebral disc (IVD) of 3 patients with chronic lower back pain who failed to improve with conservative management. CASE SERIES: For all the 3 patients, magnetic resonance imaging showed annular tears of the L5/S1 IVD with broad-based central posterior protrusions. PRP injection was performed with the patients in the lateral decubitus position or modified recovery position. With the transducer initially placed in the short axis to the lumbar spine, the needle was inserted in-plane to the IVD, with the needle trajectory clearly visualized. Once the needle entered the annulus fibrosus, placement of the needle was confirmed by turning the transducer along the long axis of the spine to validate the location of the needle tip inside the IVD. Discus stimulation was performed with contrast administered to elicit each patient's usual pain, and spread of the contrast was confirmed under fluoroscopy. Upon confirmation of the intradiscal location, 3 ml of PRP was administered. CONCLUSIONS: This report described a novel technique demonstrating that US-guided lumbar intradiscal needle placement for PRP administration in patients lying in the lateral decubitus position is feasible.

Three-patch Models for the Evolution of Dispersal in Advective Environments: Varying Drift and Network Topology.

We study the evolution of dispersal in advective three-patch models with distinct network topologies. Organisms can move between connected patches freely and they are also subject to the passive, directed drift. The carrying capacity is assumed to be the same in all patches, while the drift rates could vary. We first show that if all drift rates are the same, the faster dispersal rate is selected for all three models. For general drift rates, we show that the infinite diffusion rate is a local Convergence Stable Strategy (CvSS) for all three models. However, there are notable differences for three models: For Model I, the faster dispersal is always favored, irrespective of the drift rates, and thus the infinity dispersal rate is a global CvSS. In contrast, for Models II and III a singular strategy will exist for some ranges of drift rates and bi-stability phenomenon happens, i.e., both infinity and zero diffusion rates are local CvSSs. Furthermore, for both Models II and III, it is possible for two competing populations to coexist by varying drift and diffusion rates. Some predictions on the dynamics of n-patch models in advective environments are given along with some numerical evidence.

Prognostic factors in carpal tunnel syndrome treated with 5% dextrose perineural injection: A retrospective study.

Background: Perineural injection therapy with 5% dextrose water (D5W) is a potential and innovative treatment with long-term efficacy for carpal tunnel syndrome (CTS). However, the prognostic factors of this management are lacking; hence, the aim of this retrospective study was to identify the prognostic factors of D5W perineural injection therapy for mild-to-moderate CTS. Methods: A total of 52 patients (52 wrists) diagnosed with mild-to-moderate CTS and treated with a single ultrasound-guided 5cc D5W perineural injection were retrospectively reviewed. Patient-reported injection outcomes (visual analog scale, VAS) at 6 months post-injection were categorized into two groups; (1) Good outcome, when symptom relief ≥50% compared to pre-injection and (2) Poor outcome, when symptom relief < 50% compared to pre-injection. Significant variables between groups were entered into a binary logistic regression with forward stepwise regression to determine the prognostic factors for these outcomes. Results: The treatment outcome was significantly related to body height and sensory nerve conduction velocity (SNCV) (159.1 ± 1.0 vs. 155.0 ± 1.8, p=0.04; 33.6 ± 0.8 vs. 28.3 ± 1.2, p=0.001, good vs. poor outcomes). However, only SNCV remained significantly correlated with the outcomes after conducting stepwise logistic regression (ORs: 1.201; 95% CI 1.05-1.38; p=0.01). Conclusions: SNCV was found to be a significant prognostic factor of treatment outcome for patients with mild-to-moderate CTS 6 months after a D5W perineural injection.

Comparison of short- and long-axis nerve hydrodissection for carpal tunnel syndrome: A prospective randomized, single-blind trial.

Background: This study is to compare the efficacy of short-axis hydrodissection with long-axis hydrodissection for patients with mild-to-moderate carpal tunnel syndrome (CTS). Methods: Forty-seven patients with mild-to-moderate CTS were enrolled in a prospective, randomized, single-blinded, controlled trial (6 months follow-up). With ultrasound guidance, patients in both groups (short-axis or long-axis groups) were injected with normal saline (5 mL per session). Assessments were performed before and 2 weeks after the injection, as well as at 1, 3, and 6 months post-intervention. The primary outcome measure was the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) score and secondary outcomes included the cross-sectional area of the median nerve and electrophysiological studies. Results: Forty-four patients (21 wrists in the short-axis group and 23 wrists in the long-axis group) completed the study. Compared with the baseline, both groups showed improved BCTQ and cross-sectional area at all follow-up assessments (p<0.05). The short-axis group was not more effective except significant improvements in BCTQ-severity and BCTQ-function 1 month post-injection compared to the long-axis group (p = 0.031 and p = 0.023, respectively). Conclusions: Both short- and long-axis hydrodissection were effective for patients with mild-to-moderate CTS and the short-axis approach was not more effective than long-axis injection. Further studies with larger sample sizes, multiple injections, and larger injection volume are encouraged in the future.

Analysis of a mathematical model of immune response to fungal infection.

Fungi are cells found as commensal residents, on the skin, and on mucosal surfaces of the human body, including the digestive track and urogenital track, but some species are pathogenic. Fungal infection may spread into deep-seated organs causing life-threatening infection, especially in immune-compromised individuals. Effective defense against fungal infection requires a coordinated response by the innate and adaptive immune systems. In the present paper we introduce a simple mathematical model of immune response to fungal infection consisting of three partial differential equations, for the populations of fungi (F), neutrophils (N) and cytotoxic T cells (T), taking N and T to represent, respectively, the innate and adaptive immune cells. We denote by [Formula: see text] the aggressive proliferation rate of the fungi, by [Formula: see text] and [Formula: see text] the killing rates of fungi by neutrophils and T cells, and by [Formula: see text] and [Formula: see text] the immune strengths, respectively, of N and T of an infected individual. We take the expression [Formula: see text] to represent the coordinated defense of the immune system against fungal infection. We use mathematical analysis to prove the following: If [Formula: see text], then the infection is eventually stopped, and [Formula: see text] as [Formula: see text]; and (ii) if [Formula: see text] then the infection cannot be stopped and F converges to some positive constant as [Formula: see text]. Treatments of fungal infection include anti-fungal agents and immunotherapy drugs, and both cause the parameter I to increase.

Are Two-Patch Models Sufficient? The Evolution of Dispersal and Topology of River Network Modules.

We study the dynamics of two competing species in three-patch models and illustrate how the topology of directed river network modules may affect the evolution of dispersal. Each model assumes that patch 1 is at the upstream end, patch 3 is at the downstream end, but patch 2 could be upstream, or middle stream, or downstream, depending on the specific topology of the modules. We posit that individuals are subject to both unbiased dispersal between patches and passive drift from one patch to another, depending upon the connectivity of patches. When the drift rate is small, we show that for all models, the mutant species can invade when rare if and only if it is the slower disperser. However, when the drift rate is large, most models predict that the faster disperser wins, while some predict that there exists one evolutionarily singular strategy. The intermediate range of drift is much more complex: most models predict the existence of one singular strategy, but it may or may not be evolutionarily stable, again depending upon the topology of modules, while one model even predicts that for some intermediate drift rate, singular strategy does not exist and the faster disperser wins the competition.

Analysis of a mathematical model of rheumatoid arthritis.

Rheumatoid arthritis is an autoimmune disease characterized by inflammation in the synovial fluid within the synovial joint connecting two contiguous bony surfaces. The inflammation diffuses into the cartilage adjacent to each of the bony surfaces, resulting in their gradual destruction. The interface between the cartilage and the synovial fluid is an evolving free boundary. In this paper we consider a two-phase free boundary problem based on a simplified model of rheumatoid arthritis. We prove global existence and uniqueness of a solution, and derive properties of the free boundary. In particular it is proved that the free boundary increases in time, and the cartilage shrinks to zero as [Formula: see text], even under treatment by a drug. It is also shown in the reduced one-phased problem, with cartilage alone, that a larger prescribed inflammation function leads to a faster destruction of the cartilage.

Rituximab-PECC induction followed by 90 Y-ibritumomab tiuxetan consolidation in relapsed or refractory DLBCL patients who are ineligible for or have failed ASCT: results from a phase II HOVON study.

Patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) after, or ineligible for, autologous stem cell transplantation (ASCT) have a dismal prognosis. This phase II study evaluated treatment with R-PECC (rituximab, prednisolone, etoposide, chlorambucil, lomustine), every 28 days for 4 cycles in 62 patients, followed by radio-immunotherapy consolidation with 90 Y-ibritumomab tiuxetan in responsive patients. Primary endpoints were failure-free survival (FFS) and incidence of grade ≥3 adverse events from start of 90 Y-ibritumomab tiuxetan. The overall response rate after R-PECC was 50%. Twenty-nine of 31 responsive patients proceeded to 90 Y-ibritumomab tiuxetan. Five out of 15 partial remission patients converted to complete remission after 90 Y-ibritumomab tiuxetan. One-year FFS and overall survival (OS) from start of 90 Y-ibritumomab tiuxetan was 52% (95% confidence interval [CI], 33-68%) and 62% (95% CI, 42-77%), respectively. One-year FFS and OS from start of R-PECC was 28% (95% CI, 17-39%) and 49% (95% CI, 36-61%), respectively. Toxicities of R-PECC and 90 Y-ibritumomab tiuxetan were mainly haematological. In conclusion, for relapsed DLBCL patients the largely oral R-PECC regimen achieves promising response rates, combined with an acceptable safety profile. Consolidation with 90 Y-ibritumomab tiuxetan resulted in long-term response durations in approximately one third of the patients that received it.

Dynamics of a consumer-resource reaction-diffusion model : Homogeneous versus heterogeneous environments.

We study the dynamics of a consumer-resource reaction-diffusion model, proposed recently by Zhang et al. (Ecol Lett 20(9):1118-1128, 2017), in both homogeneous and heterogeneous environments. For homogeneous environments we establish the global stability of constant steady states. For heterogeneous environments we study the existence and stability of positive steady states and the persistence of time-dependent solutions. Our results illustrate that for heterogeneous environments there are some parameter regions in which the resources are only partially limited in space, a unique feature which does not occur in homogeneous environments. Such difference between homogeneous and heterogeneous environments seems to be closely connected with a recent finding by Zhang et al. (2017), which says that in consumer-resource models, homogeneously distributed resources could support higher population abundance than heterogeneously distributed resources. This is opposite to the prediction by Lou (J Differ Equ 223(2):400-426, 2006. https://doi.org/10.1016/j.jde.2005.05.010 ) for logistic-type models. For both small and high yield rates, we also show that when a consumer exists in a region with a heterogeneously distributed input of exploitable renewed limiting resources, the total population abundance at equilibrium can reach a greater abundance when it diffuses than when it does not. In contrast, such phenomenon may fail for intermediate yield rates.

Chronic signs of memory B cell activation in patients with Behçet's disease are partially restored by anti-tumour necrosis factor treatment.

OBJECTIVES: Behçet's disease (BD), an auto-inflammatory vasculitis with oro-genital ulcerations, skin lesions and uveitis, is regarded as T cell mediated. A successful trial with rituximab suggests an additive role for B cells in the pathogenesis. Therefore, we studied B cell abnormalities in BD patients and the effect of TNF-blocking therapy. METHODS: B cells in blood (n = 36) and tissue (n = 6) of BD patients were analysed with flow cytometry and/or immunohistochemistry and compared with healthy controls (n = 22). BD current activity form (BDCAF) in relation to B cell somatic hypermutations (SHMs) and immunoglobulin class-switching were studied. RESULTS: Thirty-six patients (17 males) were included, mean age 44 years, average disease duration 10 years and mean BDCAF 2.7. Blood B cell numbers were significantly lower in patients than in controls (P = 0.0061), mostly due to decreased CD27+ memory B cells expressing IgM (P = 0.0001), IgG (P = 0.0002) and IgA (P = 0.0038) B cell subsets. CD27+ IgA+ B cells showed the highest magnitude of decrease in active disease, measured with BDCAF (P = 0.02). CD27+ IgM+ IgD+ B cells were impaired in replication history (P = 0.0133) and selection of SHM, whereas IgA+ B cells carried elevated SHM levels (P = 0.04) and lower IgA2 subclass usage (P = 0.0004) than controls. Immunohistochemistry revealed B cells in tissue of active mucosal ulcers. In adalimumab-treated patients, blood B cells were similar to controls. CONCLUSION: We show significant deviations in the memory B cell compartment, related to disease activity and therapeutic efficacy. Pronounced molecular impairments were seen in the fast-responding IgM+-memory and the mucosal IgA+-memory B cells. Because of the demonstrated abundance of B cells in affected tissue, we hypothesize relocation of memory B cells to the site of inflammation could account for the deviations found in blood of BD patients. These peripheral B cells are easily accessible as a marker to monitor therapeutic efficacy.

Reinforcement of the colon anastomosis with cyanoacrylate glue: a porcine model.

BACKGROUND: Previous experimental studies on cyanoacrylate (CA) glue for the prevention of colorectal anastomotic leakage (AL) have shown promising results. The aim of this study was to investigate the effect of CA in prevention of leakage in a porcine model of ischemic colorectal AL. METHODS: Twenty-four animals were divided into four groups of six: (1)ischemic anastomosis with sufficient suture (ISCH), (2)ischemic anastomosis with sufficient suture and CA reinforcement (CA-ISCH), (3)ischemic anastomosis with insufficient suture (ISCH-AI), and (4)ischemic anastomosis with insufficient suture and CA reinforcement (CA-ISCH-AI). In CA groups, N-butyl-2-cyanoacrylate was applied between the colon ends. Anastomotic bursting pressure, abscess formation, and adhesion formation were evaluated on postoperative day 7. Tissue samples were obtained for histologic evaluation of foreign body reaction. RESULTS: The AL rate was 4 of 6 (67%) in the ISCH-AI group compared with none in the other three groups. The ISCH and ISCH-AI groups had significantly higher AL scores compared with the CA groups. The mean anastomotic bursting pressure was 167 ± 54 mm Hg in the ISCH-group versus 213 ± 43 mm Hg in the CA-ISCH-group (P = nonsignificant) and 145 ± 102 mm Hg in the ISCH-AI group versus 187 ± 19 mm Hg in the CA-ISCH-AI group (P = nonsignificant). The average adhesion score was significantly higher in the ISCH group than in the CA-ISCH group (4.2 ± 1.3 versus 1.7 ± 0.82; P = 0.019). Stricture of the anastomosis occurred only in the non-CA groups (3/12, 25%). CONCLUSIONS: Anastomotic reinforcement with CA is effective and safe to prevent leakage in a high-risk colorectal anastomosis in a porcine model.

Dimorphism by Singularity Theory in a Model for River Ecology.

Geritz, Gyllenberg, Jacobs, and Parvinen show that two similar species can coexist only if their strategies are in a sector of parameter space near a nondegenerate evolutionarily singular strategy. We show that the dimorphism region can be more general by using the unfolding theory of Wang and Golubitsky near a degenerate evolutionarily singular strategy. Specifically, we use a PDE model of river species as an example of this approach. Our finding shows that the dimorphism region can exhibit various different forms that are strikingly different from previously known results in adaptive dynamics.