Locomotor adaptability in persons with unilateral transtibial amputation

Background Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. Objective Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). Methods The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. Results Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. Conclusions Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb

Percutaneous vascular interventions for acute ischaemic stroke.

peer-reviewedMost disabling strokes are due to blockage of a large artery in the brain by a blood clot. Prompt removal of the clot with intra-arterial thrombolytic drugs or mechanical devices, or both, can restore blood flow before major brain damage has occurred, leading to improved recovery. However, these so-called percutaneous vascular interventions can cause bleeding in the brain.PUBLISHEDpeer-reviewe

Phosphodiesterase type 4 expression and anti-proliferative effects in human pulmonary artery smooth muscle cells

BACKGROUND: Pulmonary arterial hypertension is a proliferative vascular disease, characterized by aberrant regulation of smooth muscle cell proliferation and apoptosis in distal pulmonary arteries. Prostacyclin (PGI(2)) analogues have anti-proliferative effects on distal human pulmonary artery smooth muscle cells (PASMCs), which are dependent on intracellular cAMP stimulation. We therefore sought to investigate the involvement of the main cAMP-specific enzymes, phosphodiesterase type 4 (PDE4), responsible for cAMP hydrolysis. METHODS: Distal human PASMCs were derived from pulmonary arteries by explant culture (n = 14, passage 3–12). Responses to platelet-derived growth factor-BB (5–10 ng/ml), serum, PGI(2 )analogues (cicaprost, iloprost) and PDE4 inhibitors (roflumilast, rolipram, cilomilast) were determined by measuring cAMP phosphodiesterase activity, intracellular cAMP levels, DNA synthesis, apoptosis (as measured by DNA fragmentation and nuclear condensation) and matrix metalloproteinase-2 and -9 (MMP-2, MMP-9) production. RESULTS: Expression of all four PDE4A-D genes was detected in PASMC isolates. PDE4 contributed to the main proportion (35.9 ± 2.3%, n = 5) of cAMP-specific hydrolytic activity demonstrated in PASMCs, compared to PDE3 (21.5 ± 2.5%), PDE2 (15.8 ± 3.4%) or PDE1 activity (14.5 ± 4.2%). Intracellular cAMP levels were increased by PGI(2 )analogues and further elevated in cells co-treated with roflumilast, rolipram and cilomilast. DNA synthesis was attenuated by 1 μM roflumilast (49 ± 6% inhibition), rolipram (37 ± 6%) and cilomilast (30 ± 4%) and, in the presence of 5 nM cicaprost, these compounds exhibited EC(50 )values of 4.4 (2.6–6.1) nM (Mean and 95% confidence interval), 59 (36–83) nM and 97 (66–130) nM respectively. Roflumilast attenuated cell proliferation and gelatinase (MMP-2 and MMP-9) production and promoted the anti-proliferative effects of PGI(2 )analogues. The cAMP activators iloprost and forskolin also induced apoptosis, whereas roflumilast had no significant effect. CONCLUSION: PDE4 enzymes are expressed in distal human PASMCs and the effects of cAMP-stimulating agents on DNA synthesis, proliferation and MMP production is dependent, at least in part, on PDE4 activity. PDE4 inhibition may provide greater control of cAMP-mediated anti-proliferative effects in human PASMCs and therefore could prove useful as an additional therapy for pulmonary arterial hypertension

Chromatophore Activity during Natural Pattern Expression by the Squid Sepioteuthis lessoniana: Contributions of Miniature Oscillation

Squid can rapidly change the chromatic patterns on their body. The patterns are created by the expansion and retraction of chromatophores. The chromatophore consists of a central pigment-containing cell surrounded by radial muscles that are controlled by motor neurons located in the central nervous system (CNS). In this study we used semi-intact squid (Sepioteuthis lessoniana) displaying centrally controlled natural patterns to analyze spatial and temporal activities of chromatophores located on the dorsal mantle skin. We found that chromatophores oscillated with miniature expansions/retractions at various frequencies, even when the chromatic patterns appear macroscopically stable. The frequencies of this miniature oscillation differed between “feature” and “background” areas of chromatic patterns. Higher frequencies occurred in feature areas, whereas lower frequencies were detected in background areas. We also observed synchronization of the oscillation during chromatic pattern expression. The expansion size of chromatophores oscillating at high frequency correlated with the number of synchronized chromatophores but not the oscillation frequency. Miniature oscillations were not observed in denervated chromatophores. These results suggest that miniature oscillations of chromatophores are driven by motor neuronal activities in the CNS and that frequency and synchrony of this oscillation determine the chromatic pattern and the expansion size, respectively

Analysis of Genetic Variation and Phylogeny of the Predatory Bug, Pilophorus typicus, in Japan using Mitochondrial Gene Sequences

Pilophorus typicus (Distant) (Heteroptera: Miridae) is a predatory bug occurring in East, Southeast, and South Asia. Because the active stages of P. typicus prey on various agricultural pest insects and mites, this species is a candidate insect as an indigenous natural enemy for use in biological control programs. However, the mass releasing of introduced natural enemies into agricultural fields may incur the risk of affecting the genetic integrity of species through hybridization with a local population. To clarify the genetic characteristics of the Japanese populations of P. typicus two portions of the mitochondrial DNA, the cytochrome oxidase subunit I (COI) (534 bp) and the cytochrome B (cytB) (217 bp) genes, were sequenced for 64 individuals collected from 55 localities in a wide range of Japan. Totals of 18 and 10 haplotypes were identified for the COI and cytB sequences, respectively (25 haplotypes over regions). Phylogenetic analysis using the maximum likelihood method revealed the existence of two genetically distinct groups in P. typicus in Japan. These groups were distributed in different geographic ranges: one occurred mainly from the Pacific coastal areas of the Kii Peninsula, the Shikoku Island, and the Ryukyu Islands; whereas the other occurred from the northern Kyushu district to the Kanto and Hokuriku districts of mainland Japan. However, both haplotypes were found in a single locality of the southern coast of the Shikoku Island. COI phylogeny incorporating other Pilophorus species revealed that these groups were only recently differentiated. Therefore, use of a certain population of P. typicus across its distribution range should be done with caution because genetic hybridization may occur

Estrogen receptor transcription and transactivation: Structure-function relationship in DNA- and ligand-binding domains of estrogen receptors

Estrogen receptors are members of the nuclear receptor steroid family that exhibit specific structural features, ligand-binding domain sequence identity and dimeric interactions, that single them out. The crystal structures of their DNA-binding domains give some insight into how nuclear receptors discriminate between DNA response elements. The various ligand-binding domain crystal structures of the two known estrogen receptor isotypes (α and β) allow one to interpret ligand specificity and reveal the interactions responsible for stabilizing the activation helix H12 in the agonist and antagonist positions

Spermatogonial Stem Cells (SSCs) in Buffalo (Bubalus bubalis) Testis

BACKGROUND: Water buffalo is an economically important livestock species and about half of its total world population exists in India. Development of stem cell technology in buffalo can find application in targeted genetic modification of this species. Testis has emerged as a source of pluripotent stem cells in mice and human; however, not much information is available in buffalo. OBJECTIVES AND METHODS: Pou5f1 (Oct 3/4) is a transcription factor expressed by pluripotent stem cells. Therefore, in the present study, expression of POU5F1 transcript and protein was examined in testes of both young and adult buffaloes by semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemical analysis. Further, using the testis transplantation assay, a functional assay for spermatogonial stem cells (SSCs), stem cell potential of gonocytes/spermatogonia isolated from prepubertal buffalo testis was also determined. RESULTS: Expression of POU5F1 transcript and protein was detected in prepubertal and adult buffalo testes. Western blot analysis revealed that the POU5F1 protein in the buffalo testis exists in two isoforms; large (∼47 kDa) and small (∼21 kDa). Immunohistochemical analysis revealed that POU5F1 expression in prepubertal buffalo testis was present in gonocytes/spermatogonia and absent from somatic cells. In the adult testis, POU5F1 expression was present primarily in post-meiotic germ cells such as round spermatids, weakly in spermatogonia and spermatocytes, and absent from elongated spermatids. POU5F1 protein expression was seen both in cytoplasm and nuclei of the stained germ cells. Stem cell potential of prepubertal buffalo gonocytes/spermatogonia was confirmed by the presence of colonized DBA-stained cells in the basal membrane of seminiferous tubules of xenotransplanted mice testis. CONCLUSION/SIGNIFICANCE: These findings strongly indicate that gonocytes/spermatogonia, isolated for prepubertal buffalo testis can be a potential target for establishing a germ stem cell line that would enable genetic modification of buffaloes

PI3Kδ and PI3Kγ isoforms have distinct functions in regulating pro-tumoural signalling in the multiple myeloma microenvironment

Phosphoinositide-3-kinase and protein kinase B (PI3K-AKT) is upregulated in multiple myeloma (MM). Using a combination of short hairpin RNA (shRNA) lentivirus-mediated knockdown and pharmacologic isoform-specific inhibition we investigated the role of the PI3K p110γ (PI3Kγ) subunit in regulating MM proliferation and bone marrow microenvironment-induced MM interactions. We compared this with inhibition of the PI3K p110δ (PI3kδ) subunit and with combined PI3kδ/γ dual inhibition. We found that MM cell adhesion and migration were PI3Kγ-specific functions, with PI3kδ inhibition having no effect in MM adhesion or migration assays. At concentration of the dual PI3Kδ/γ inhibitor duvelisib, which can be achieved in vivo we saw a decrease in AKT phosphorylation at s473 after tumour activation by bone marrow stromal cells (BMSC) and interleukin-6. Moreover, after drug treatment of BMSC/tumour co-culture activation assays only dual PI3kδ/γ inhibition was able to induce MM apoptosis. shRNA lentiviral-mediated targeting of either PI3Kδ or PI3Kγ alone, or both in combination, increased survival of NSG mice xeno-transplanted with MM cells. Moreover, treatment with duvelisib reduced MM tumour burden in vivo. We report that PI3Kδ and PI3Kγ isoforms have distinct functions in MM and that combined PI3kδ/γ isoform inhibition has anti-MM activity. Here we provide a scientific rationale for trials of dual PI3kδ/γ inhibition in patients with MM

CD40, autophagy and Toxoplasma gondii

Toxoplasmagondii represents a pathogen that survives within host cells by preventing the endosomal-lysosomal compartments from fusing with the parasitophorous vacuoles. The dogma had been that the non-fusogenic nature of these vacuoles is irreversible. Recent studies revealed that this dogma is not correct. Cell-mediated immunity through CD40 re-routes the parasitophorous vacuoles to the lysosomal compartment by a process called autophagy. Autophagosome formation around the parasitophorous vacuole results in killing of the T. gondii. CD40-induced autophagy likely contributes to resistance against T. gondii particularly in neural tissue

The Progression of Liver Fibrosis Is Related with Overexpression of the miR-199 and 200 Families

Chronic hepatitis C (CH) can develop into liver cirrhosis (LC) and hepatocellular carcinoma (HCC). Liver fibrosis and HCC development are strongly correlated, but there is no effective treatment against fibrosis because the critical mechanism of progression of liver fibrosis is not fully understood. microRNAs (miRNAs) are now essential to the molecular mechanisms of several biological processes. In order to clarify how the aberrant expression of miRNAs participates in development of the liver fibrosis, we analyzed the liver fibrosis in mouse liver fibrosis model and human clinical samples