The effect of increasing sets (within one treatment session) and different set durations (between treatment sessions) of lumbar spine posteroanterior mobilisations on pressure pain thresholds

Spinal mobilisations are a common form of treatment intervention applied by physiotherapists in clinical practice to manage musculoskeletal pain and/or dysfunction. Previous research has demonstrated that mobilisations cause a hypoalgesic effect. However, there is very little research investigating the optimal treatment dose inducing this effect.AimTo investigate the effect of the number of sets (up to 5) and different durations (30 vs. 60 s) on pressure pain thresholds (PPTs) at different sites.MethodsThis single-blinded, randomised, same subject repeated measures crossover design included 19 asymptomatic healthy volunteers. The participants received 5 sets of either 30 or 60 s of postero-anterior mobilisations to L4 on different days. PPTs were measured immediately before, between and after the intervention at 4 different standardised sites.ResultsA 4-way ANOVA analysis revealed that there was no statistically significant difference between 30 versus 60 s of mobilisations. However, there was a tendency for PPT values to be higher for the 60 s intervention. All PPT measurements after the interventions were significantly higher than the baseline. Only the measurement after the 4th set of mobilisations was significantly higher than the measurement after the 1st set (p = 0.035).ConclusionsThe results suggest that in order to induce the greatest local hypoalgesia, at least 4 sets of mobilisations are required. The different durations of 30 versus 60 s of mobilisation may not change the extent of the hypoalgesic effect.     

Complicated Grief,Depression, Health and Attachment Style in First Degree Relatives of Individuals with a Chronic Psychotic Disorders

Complicated grief (CG) is a form of unrelenting grief after the death of a loved one. However, family members of individuals who suffer from Schizophrenia, Schizoaffective disorders and Bipolar disorder may experience symptoms of CG even though their loved one is still alive. The present study assessed CG and risk factors for CG in first degree relatives of individuals with severe chronic mental illness. The incidence of CG was examined in 78 parents, siblings, adult children and spouses recruited through organizations and social media that provide support services for individuals suffering from mental illness and their families. High rates of CG (39.7%) were found in this group. CG was associated with a higher prevalence of posttraumatic and depression symptoms and poorer physical health. These findings may contribute to heightening therapists' awareness of the importance of assessing, acknowledging and resolving CG in the family members of patients with chronic psychotic disorders.

     

When is Higher Level Cognitive Control Needed for Locomotor Tasks Among Patients with Parkinson’s Disease?

Turning has been implicated as a complex task that requires both motor and cognitive resources. Accumulating evidence shows that patients with Parkinson’s disease (PD) require more steps and more time to complete a turn, however, the role of the prefrontal cortex during turning is not clear. Forty nine patients with PD without freezing of gait (mean age 71.7?±?1.0 years; 67% men, disease duration 9.7?±?1.3 years) performed motor and cognitive tests. Prefrontal activation, specifically in Brodmann area 10 (BA10), during turning and usual walking was measured using functional near infrared spectroscopy (fNIRS). The patients with PD were further divided into two subgroups with high and low functional status based on limitations in community ambulation. General Linear Model analysis adjusted for age, gender, disease duration and turn duration was used to assess differences between tasks and subgroups of patients with PD. In addition, Pearson’s correlation was performed to assess association between BA10 activation and motor and cognitive scores. Activation in BA10 increased during walking (p?<?0.001), while it decreased during turning (p?=?0.006). A comparison between the two subgroups of patients with PD revealed that patients with relatively better ambulation decreased prefrontal activation during turning, as compared to patients with relatively worse ambulation (p?<?0.001). These findings are the first to show that BA10 plays a different role during turning and walking and that ambulation status may alter BA10 activation during turning. Higher prefrontal activation during turning in the subgroup of patients with relatively worse ambulation may reflect a compensatory attempt at improving performance.     

Analysis of Arg834Gln and Val902Glu type 2A von Willebrand disease mutations: studies with recombinant von Willebrand factor and correlation with patient characteristics

Type 2A von Willebrand disease (vWD), the most common qualitative form of vWD, is characterized by a relative decrease in circulating intermediate and high molecular weight (HMW) multimers. We studied the biosynthesis of recombinant von Willebrand factor (vWF) containing each of two type 2A vWD mutations previously reported by us, Arg834Gln and Val902Glu. The structure of recombinant Arg834Gln vWF within transfected COS-7 cells and the secretion of HMW multimers were similar to wild type vWF. The normal transport and secretion of Arg834Gln vWF, categorizes it as a group II type 2A mutation. In contrast, the Val90- 2Glu mutation resulted in intracellular proteolysis of vWF with the generation of a 176-kD fragment and retention of vWF between the endoplasmic reticulum and the Golgi complex. Moreover, the 176-kD fragment was also increased in plasma from patients with the Val902Glu mutation. Significantly impaired secretion and intracellular proteolysis of Val902Glu vWF categorizes a new sub-group of type 2A mutations. The intracellular proteolysis of vWF Val902Glu explains the lack of response to 1-deamino 8-D-arginine vasopressin (DDAVP) in patients who carry the mutation.     

Methionine synthase A2756G and methylenetetrahydrofolate reductase A1298C polymorphisms are not risk factors for idiopathic venous thromboembolism

Hyperhomocysteinemia is a defined risk factor for venous thromboembolism (VTE). Several polymorphisms of genes encoding for enzymes acting in the remethylation pathway of homocysteine metabolism, ie, methionine synthase (MS) A2756G, methylenetetrahydrofolate reductase (MTHFR) C677T and MTHFR A1298C, can cause increased homocysteine levels particularly in patients with deficiencies of folic acid, vitamin B6, or B12 and hence be potential risk factors for VTE. Indeed, homozygous MTHFR C677T was shown to be a mild risk factor for VTE by some, but not by all, investigators. In this study, we assessed the risk exerted by MS A2756G and MTHFR A1298C in a cohort of patients with idiopathic venous thromboembolism. Homozygosities for MS A2756G and MTHFR A1298C were not found to be statistically significant risk factors for VTE. In addition, no interactions were observed among MS A2756G, MTHFR A1298C and MTHFR C677T in conferring a risk of VTE.     

Spatiotemporal effects of microsaccades on population activity in the visual cortex of monkeys during fixation

During visual fixation, the eyes make fast involuntary miniature movements known as microsaccades (MSs). When MSs are executed they displace the visual image over the retina and can generate neural modulation along the visual pathway. However, the effects of MSs on neural activity have substantial variability and are not fully understood. By utilizing voltage-sensitive dye imaging, we imaged the spatiotemporal patterns induced by MSs in V1 and V2 areas of behaving monkeys while they were fixating and presented with visual stimuli. We then investigated the neuronal modulation dynamics, induced by MSs, under different visual stimulation. MSs induced monophasic or biphasic neural responses depending on stimulus size. These neural responses were accompanied by different spatiotemporal patterns of synchronization. Finally, we show that a local patch of population response evoked by a small stimulus was clearly shifted over the V1 retinotopic map after each MS. Our results demonstrate the lack of visual stability in V1 following MSs and help clarify the substantial variability reported for MSs effects on neuronal responses. The observed neural effects suggest that MSs are associated with a continuum of neuronal responses in V1 area reflecting diverse spatiotemporal dynamics.     

Harnessing RNAi-based nanomedicines for therapeutic gene silencing in B-cell malignancies

Despite progress in systemic small interfering RNA (siRNA) delivery to the liver and to solid tumors, systemic siRNA delivery to leukocytes remains challenging. The ability to silence gene expression in leukocytes has great potential for identifying drug targets and for RNAi-based therapy for leukocyte diseases. However, both normal and malignant leukocytes are among the most difficult targets for siRNA delivery as they are resistant to conventional transfection reagents and are dispersed in the body. We used mantle cell lymphoma (MCL) as a prototypic blood cancer for validating a novel siRNA delivery strategy. MCL is an aggressive B-cell lymphoma that overexpresses cyclin D1 with relatively poor prognosis. Down-regulation of cyclin D1 using RNA interference (RNAi) is a potential therapeutic approach to this malignancy. Here, we designed lipid-based nanoparticles (LNPs) coated with anti-CD38 monoclonal antibodies that are specifically taken up by human MCL cells in the bone marrow of xenografted mice. When loaded with siRNAs against cyclin D1, CD38-targeted LNPs induced gene silencing in MCL cells and prolonged survival of tumor-bearing mice with no observed adverse effects. These results highlight the therapeutic potential of cyclin D1 therapy in MCL and present a novel RNAi delivery system that opens new therapeutic opportunities for treating MCL and other B-cell malignancies.RNA interference (RNAi) can be activated by introducing synthetic short double-stranded RNA fragments, termed small interfering RNAs (siRNAs), into cells to silence genes bearing complementary sequences. RNAi holds great promise as a powerful tool for evaluating the role of specific genes in cellular and disease processes and for therapeutic applications (1, 2). siRNAs that manipulate gene expression in leukocytes could be used to understand hematologic cell biology and to develop novel therapeutic approaches to dampen inflammation and the harmful immune responses that occur during autoimmunity; to suppress lymphotropic viral infections, such as HIV; or to treat blood cancers (3). However, the lack of systemic delivery startegies to target leukocytes foils these applications.Here we devised a new strategy to target B-cell malignancies using mantle cell lymphoma (MCL) as a prototypic blood cancer to validate this siRNA delivery approach. MCL is an aggressive B-cell malignancy characterized by a t(11:14) chromosomal translocation that juxtaposes the proto-oncogene encoding cyclin D1 (cycD1) to the Ig heavy chain gene promotor (4). This leads to constitutive overexpression of cycD1, a protein that is not expressed in healthy B-lymphocytes. Current MCL therapy relies mainly on conventional chemotherapy; anti-CD20 cytotoxic monoclonal antibodies; autologous stem cell transplantation; and, more recently, small molecule inhibitors of critical molecular pathways, such as the BTK inhibitor ibrutinib (5). Unfortunately, relapse and progressive resistance to treatment lead to short median survival. MCL has one of the worst prognoses among lymphomas (6–8). Thus, there is a need for new therapeutic approaches.We previously showed that cycD1 down-regulation in MCL cell lines using RNAi inhibits proliferation and causes cell cycle arrest and apoptosis (9). However, the clinical application of this approach is hindered by the lack of appropriate systems that could deliver RNAi payloads to MCL cells in an efficient and safe manner (10, 11). RNAi therapeutics for B-cell malignancies is especially challenging because these cells are dispersed and are intrinsically resistant to transfection with nucleic acids (3, 12, 13). Therefore, to test the potential therapeutic effect of cycD1 inhibition in vivo and to demonstrate the feasibility of RNAi therapeutics in MCL, we needed to develop a suitable RNAi-delivery platform for potent gene silencing.Lipid-based nanoparticles (LNPs), composed of ionizable lipids that incorporate siRNAs, can induce potent gene silencing in the liver (14, 15). These are currently being evaluated in a phase III clinical study to knock down the TTR gene expressed in the liver to treat familial amyloidosis (16). We recently demonstrated that LNPs could be surface-modified with a natural ligand or a monoclonal antibody to improve in vivo delivery of siRNA payloads (17, 18). Here we investigate the use of antibody-targeted LNPs to deliver siRNAs to MCL cells. The blood supply in the hematological tissues where MCL cells mostly reside, including spleen and bone marrow, is made up of sinusoids that allow small nanoparticles tissue access. Selective targeting of lymphoma cells by antibody-targeted delivery should be clinically beneficial because it could reduce the total amount of drug required for therapeutic benefit and reduce toxicity to bystander cells (2, 12).CD38 is expressed on the surface of immature hematopoietic cells, including immature B cells. Its expression is tightly regulated during B-cell ontogeny; it is expressed on bone marrow precursors, but not mature B cells. CD38 is expressed on most MCLs (19). In the present study, we show that CD38 is a suitable target for antibody-mediated delivery of therapeutic siRNAs to MCL. LNPs–siRNA coated with an anti-CD38 monoclonal antibody (αCD38 mAb) showed specific MCL binding in vitro (in MCL cell lines and MCL primary lymphomas) and in vivo (in mice xenografted with a human MCL cell line). CD38-targeted LNPs (αCD38-LNPs) entrapping siRNA against cycD1 (siCycD1) were specifically taken up by MCL xenografts. αCD38-LNPs-siCycD1 induced gene silencing, suppressed tumor cell growth in vitro, and prolonged the survival of MCL-bearing mice. Our data demonstrate the effectiveness of inhibiting cycD1 in MCL in vivo and highlight αCD38–LNPs–siRNA as part of a strategy that could ultimately become a novel therapeutic modality for treating MCL and other CD38-expressing hematological malignancies.