Search

Regeneration of orofacial tissues is hampered by the lack of adequate vascular supply. Implantation of in vitro engineered, prevascularized constructs has emerged as a strategy to allow the rapid vascularization of the entire graft. Given the angiogenic properties of dental pulp stem cells, we hereby established a preclinical model of prevascularized constructs loaded with stem cells from human exfoliating deciduous teeth (SHED) in a 3-dimensional-printed material and provided a functional analysis of their in vivo angiogenesis, vascular perfusion, and permeability. Three different cell-loaded collagen hydrogels (SHED–human umbilical vein endothelial cell [HUVEC], HUVEC with SHED-conditioned medium, and SHED alone) were cast in polylactic acid (PLA) grids and ectopically implanted in athymic mice. At day 10, in vivo positron emission tomography (PETscan) revealed a significantly increased uptake of radiotracer targeting activated endothelial cells in the SHED-HUVEC group compared to the other groups. At day 30, ex vivo micro–computed tomography imaging confirmed that SHED-HUVEC constructs had a significantly increased vascular volume compared to the other ones. Injection of species-specific lectins analyzed by 2-photon microscopy demonstrated blood perfusion of the engineered human vessels in both prevascularized groups. However, in vivo quantification showed increased vessel density in the SHED-HUVEC group. In addition, coinjection of fluorescent lectin and dextran revealed that prevascularization with SHED prevented vascular leakage, demonstrating the active role of SHED in the maturation of human-engineered microvascular networks. This preclinical study introduces a novel PLA prevascularized and implantable construct, along with an array of imaging techniques, to validate the ability of SHED to promote functional human-engineered vessels, further highlighting the interest of SHED for orofacial tissue engineering. Furthermore, this study validates the use of PETscan for the early detection of in vivo angiogenesis, which may be applied in the clinic to monitor the performance of prevascularized grafts. [ABSTRACT FROM AUTHOR]

Cissus quadrangularis (C. quadrangularis) is a plant of the Vitaceae family known for its anticonvulsant effects in traditional medicine. The objective of this study was to elucidate the anxiolytic and antiepileptic effects of aqueous extract of C. quadrangularis. The mice were divided into different groups and treated for seven consecutive days as follows: a negative control group that received distilled water, po, four test groups that received four doses of the plant (37.22, 93.05, 186.11, and 372.21 mg/kg, po), and a positive control group that received sodium valproate (300 mg/kg, ip). One hour after the first treatment (first day), epilepsy was induced by intraperitoneal administration of a single dose of pilocarpine (360 mg/kg). On the seventh day, the anxiolytic effects of the extract were evaluated in the epileptic mice using the elevated plus maze (EPM) and open field (OP) paradigms. Antioxidant activities and the involvement of gabaergic neurotransmission were determined by measuring the levels of malondialdehyde, reduced glutathione (GSH), GABA, and GABA-transaminase (GABA-T) in the hippocampus of sacrificed epileptic mice. The results show that the extract of C. quadrangularis significantly and dose-dependently increased the latency to clonic and generalized tonic–clonic seizures and decreased the number and duration of seizures. In the EPM, the extract of C. quadrangularis significantly increased the number of entries and the time spent into the open arms and reduced the number of entries and the time spent into the closed arms as well as the number of rearing. The extract of C. quadrangularis also increased the number of crossing, and the time spent in the center of the OP. The level of MDA and the activity of GABA-T were significantly decreased by the extract of C. quadrangularis while reduced GSH and GABA levels were increased. The results suggest that the anticonvulsant activities of C. quadrangularis are accompanied by its anxiolytics effects. These effects may be supported by its antioxidant properties and mediated at least in part by the GABA neurotransmission.

Alzheimer’s disease the most common form of dementia in the elderly is a neurodegenerative disease that affects 44 millions of people worldwide. The first treatments against Alzheimer’s disease are acetylcholinesterase inhibitors; however, these medications are associated with many side effects. Dichrocephala integrifolia is a traditional herb widely used by indigenous population of Cameroon to treat and prevent Alzheimer’s disease and for memory improvement. In this study, we evaluated the effect of the decoction prepared from leaves of D. integrifolia, on scopolamine-induced memory impairment in mice. Seven groups of six animals were used. The first two groups received distilled water for the distilled water and scopolamine groups. The four test groups received one of the four doses of the decoction of the plant (35, 87.5, 175 or 350 mg/kg p.o.) and the positive control group received tacrine (10 mg/kg), a cholinesterase inhibitor used in the treatment of Alzheimer’s disease, during 10 consecutive days. Scopolamine (1 mg/kg), a cholinergic receptor blocker, administered 30 min after treatments, was used to induce memory impairment to all groups except the distilled water group on day 10 of drug treatment. The behavioral paradigms used to evaluate the effects of the treatment were the elevated plus maze for learning and memory, Y maze for spatial short-term memory, the novel object recognition for recognition memory and Morris water maze for the evaluation of spatial long-term memory. After behavioral tests, animals were sacrificed and brains of a subset were used for the assessment of some biomarkers of oxidative stress (malondialdehyde and reduced glutathione levels) and for the evaluation of the acetylcholinesterase activity. From the remaining subset brains, histopathological analysis was performed. The results of this study showed that, D. integrifolia at the doses of 87.5 and 350 mg/kg significantly (p < 0.01) improved spatial short-term and long-term memory, by increasing the percentage of spontaneous alternation in the Y maze and reducing the escape latency in the Morris water maze. Furthermore, the results of histopathological evaluation showed that D. integrifolia attenuated the neuronal death in the hippocampus induced by scopolamine. The main finding of this work is that D. integrifolia improves learning capacities and counteracts the memory impairment induced by scopolamine. Thus, D. integrifolia can be a promising plant resource for the management of Alzheimer’s disease and memory loss.

In this study, we investigated antiepileptogenic and neuroprotective effects of the aqueous extract of Pergularia daemia roots (PDR) using in vivo and in vitro experimental models. In in vivo studies, status epilepticus caused by pilocarpine injection triggers epileptogenesis which evolves during about 1–2 weeks. After 2 h of status epilepticus, mice were treated during the epileptogenesis period for 7 days with sodium valproate and vitamin C (standards which demonstrated to alter epileptogenesis), or Pergularia daemia. The animals were then, 1 week after status epilepticus, challenged with acute pentylenetetrazole (PTZ) administration to test behaviorally the susceptibility to a convulsant agent of animals treated or not with the plan extract. Memory was assessed after PTZ administration in the elevated plus maze and T-maze paradigms at 24 and 48 h. Antioxidant and acetylcholinesterase activities were determined in the hippocampus after sacrifice, in vitro studies were conducted using embryonic rat primary cortical cultures exposed to L-glutamate. Cell survival rate was measured and apoptotic and necrotic cell death determined. The results showed that chronic oral administration of PDR significantly and dose-dependently increased the latency to myoclonic jerks, clonic seizures and generalized tonic–clonic seizures, and the seizure score. In addition, PDR at all doses (from 4.9 to 49 mg/kg) significantly decreased the initial and retention transfer latencies in the elevated plus maze. Interestingly PDR at the same doses significantly increased the time spent and the number of entries in T-maze novel arm. PDR significantly increased the activities of acetylcholinesterase and antioxidant enzymes superoxide dismutase, catalase, and total glutathione and proteins, and decreased malondialdehyde level. Furthermore, PDR increased viability rate of primary cortical neurons after L-glutamate-induced excitotoxicity, in a dose dependent manner. Altogether these results suggest that PDR has antiepileptogenic and neuroprotective effects, which could be mediated by antioxidant and antiapoptotic activities.

A new study uses x-ray diffraction and transport and magnetic measurements to investigate the magnetic, structural and transport properties of rf sputtered Co/Ag multilayers with differing Co-layer thicknesses.

Abstract Background Infant mortality rates (IMR) remain high in many sub-Saharan African countries, especially in rural settings where access to health services may be limited. Studies in such communities can provide relevant data on the burden of and risk factors for infant death. We measured IMR and explored risk factors for infant death in a cohort of children born in Banfora Health District, a rural area in South-West Burkina Faso. Methods A prospective community-based cohort study was nested within the PROMISE-EBF trial (NCT00397150) in 24 villages of the study area. Maternal and infant baseline characteristics were collected at recruitment and after birth, respectively. Home visits were conducted at weeks 3, 6, 12, 24 and 52 after birth. Descriptive statistics were calculated using robust standard errors to account for cluster sampling. Cox multivariable regression was used to investigate potential risk factors for infant death. Results Among the 866 live born children included in the study there were 98 infant deaths, yielding an IMR of 113 per 1000 live births (95% CI: 89–143). Over 75% of infant deaths had occurred by 6 months of age and the post neonatal infant mortality rate was 67 per 1000 live births (95% CI: 51–88). Infections (35%) and preterm births complications (23%) were the most common probable causes of death by 6 months. Multivariable analyses identified maternal history of child death, polygyny, twin births and poor anthropometric z-scores at week-3 as factors associated with increased risk of infant death. Conclusions We observed a very high IMR in a rural area of Burkina Faso, a country where 75% of the population lives in rural settings. Community-based health interventions targeting mothers and children at high risk are urgently needed to reduce the high burden of infant deaths in these areas.

Cissus quadrangularis (C. quadrangularis) is a plant of the Vitaceae family known for its anticonvulsant effects in traditional medicine. The objective of this study was to elucidate the anxiolytic and antiepileptic effects of aqueous extract of C. quadrangularis. The mice were divided into different groups and treated for seven consecutive days as follows: a negative control group that received distilled water, po, four test groups that received four doses of the plant (37.22, 93.05, 186.11, and 372.21 mg/kg, po), and a positive control group that received sodium valproate (300 mg/kg, ip). One hour after the first treatment (first day), epilepsy was induced by intraperitoneal administration of a single dose of pilocarpine (360 mg/kg). On the seventh day, the anxiolytic effects of the extract were evaluated in the epileptic mice using the elevated plus maze (EPM) and open field (OP) paradigms. Antioxidant activities and the involvement of gabaergic neurotransmission were determined by measuring the levels of malondialdehyde, reduced glutathione (GSH), GABA, and GABA-transaminase (GABA-T) in the hippocampus of sacrificed epileptic mice. The results show that the extract of C. quadrangularis significantly and dose-dependently increased the latency to clonic and generalized tonic–clonic seizures and decreased the number and duration of seizures. In the EPM, the extract of C. quadrangularis significantly increased the number of entries and the time spent into the open arms and reduced the number of entries and the time spent into the closed arms as well as the number of rearing. The extract of C. quadrangularis also increased the number of crossing, and the time spent in the center of the OP. The level of MDA and the activity of GABA-T were significantly decreased by the extract of C. quadrangularis while reduced GSH and GABA levels were increased. The results suggest that the anticonvulsant activities of C. quadrangularis are accompanied by its anxiolytics effects. These effects may be supported by its antioxidant properties and mediated at least in part by the GABA neurotransmission. [ABSTRACT FROM AUTHOR]

Alzheimer's disease the most common form of dementia in the elderly is a neurodegenerative disease that affects 44 millions of people worldwide. The first treatments against Alzheimer's disease are acetylcholinesterase inhibitors; however, these medications are associated with many side effects. Dichrocephala integrifolia is a traditional herb widely used by indigenous population of Cameroon to treat and prevent Alzheimer's disease and for memory improvement. In this study, we evaluated the effect of the decoction prepared from leaves of D. integrifolia, on scopolamineinduced memory impairment in mice. Seven groups of six animals were used. The first two groups received distilled water for the distilled water and scopolamine groups. The four test groups received one of the four doses of the decoction of the plant (35, 87.5, 175 or 350 mg/kg p.o.) and the positive control group received tacrine (10 mg/kg), a cholinesterase inhibitor used in the treatment of Alzheimer's disease, during 10 consecutive days. Scopolamine (1 mg/kg), a cholinergic receptor blocker, administered 30 min after treatments, was used to induce memory impairment to all groups except the distilled water group on day 10 of drug treatment. The behavioral paradigms used to evaluate the effects of the treatment were the elevated plus maze for learning and memory, Y maze for spatial short-term memory, the novel object recognition for recognition memory and Morris water maze for the evaluation of spatial long-term memory. After behavioral tests, animals were sacrificed and brains of a subset were used for the assessment of some biomarkers of oxidative stress (malondialdehyde and reduced glutathione levels) and for the evaluation of the acetylcholinesterase activity. From the remaining subset brains, histopathological analysis was performed. The results of this study showed that, D. integrifolia at the doses of 87.5 and 350 mg/kg significantly (p < 0.01) improved spatial short-term and long-term memory, by increasing the percentage of spontaneous alternation in the Y maze and reducing the escape latency in the Morris water maze. Furthermore, the results of histopathological evaluation showed that D. integrifolia attenuated the neuronal death in the hippocampus induced by scopolamine. The main finding of this work is that D. integrifolia improves learning capacities and counteracts the memory impairment induced by scopolamine. Thus, D. integrifolia can be a promising plant resource for the management of Alzheimer's disease and memory loss. [ABSTRACT FROM AUTHOR]

In this study, we investigated antiepileptogenic and neuroprotective effects of the aqueous extract of Pergularia daemia roots (PDR) using in vivo and in vitro experimental models. In in vivo studies, status epilepticus caused by pilocarpine injection triggers epileptogenesis which evolves during about 1-2 weeks. After 2 h of status epilepticus, mice were treated during the epileptogenesis period for 7 days with sodium valproate and vitamin C (standards which demonstrated to alter epileptogenesis) or Pergularia daemia. The animals were then, 1 week after status epilepticus, challenged with acute pentylenetetrazole (PTZ) administration to test behaviorally the susceptibility to a convulsant agent of animals treated or not with the plan extract. Memory was assessed after PTZ administration in the elevated plus maze and T-maze paradigms at 24 and 48 h. Antioxidant and acetylcholinesterase activities were determined in the hippocampus after sacrifice, in vitro studies were conducted using embryonic rat primary cortical cultures exposed to L-glutamate. Cell survival rate was measured and apoptotic and necrotic cell death determined. The results showed that chronic oral administration of PDR significantly and dose-dependently increased the latency to myoclonic jerks, clonic seizures and generalized tonic-clonic seizures and the seizure score. In addition, PDR at all doses (from 4.9 to 49 mg/kg) significantly decreased the initial and retention transfer latencies in the elevated plus maze. Interestingly PDR at the same doses significantly increased the time spent and the number of entries in T-maze novel arm. PDR significantly increased the activities of acetylcholinesterase and antioxidant enzymes superoxide dismutase, catalase, and total glutathione and proteins, and decreased malondialdehyde level. Furthermore, PDR increased viability rate of primary cortical neurons after L-glutamate-induced excitotoxicity, in a dose dependent manner. Altogether these results suggest that PDR has antiepileptogenic and neuroprotective effects, which could be mediated by antioxidant and antiapoptotic activities. [ABSTRACT FROM AUTHOR]

Introduction: Infra-popliteal angioplasty continues to be widely performed with minimal evidence to guide practice. Endovascular device selection is contentious and there is even uncertainty over which artery to treat for optimum reperfusion. Direct reperfusion (DR) targets the artery supplying the ischaemic tissue. Indirect reperfusion (IR) targets an artery supplying collaterals to the ischaemic area. Our unit practice for the last eight years has been to attempt to open all tibial arteries at the time of angioplasty. When successful, this results in both direct and indirect; or combined reperfusion (CR). The aim was to review the outcomes of CR and compare them with DR or IR alone. Methods: An eight year retrospective review from a single unit of all infra-popliteal angioplasties was undertaken. Wound healing, limb salvage, amputation-free and overall survival data as well as re-intervention rates were captured for all patients. Subgroup analysis for diabetics was undertaken. Kaplan Meier curves are presented for survival outcomes. All odds and hazard ratios (HR) and p values were corrected for bias from confounders using multivariate analysis. Results: 250 procedures were performed: 22 (9%) were CR; 115 (46%) DR and 113 (45%) IR. Amputation-free survival (HR 0.504, p = 0.039) and re-intervention and amputation-free survival (HR 0.414, p = 0.005) were significantly improved in patients undergoing CR compared to IR. Wound healing was similarly affected by reperfusion strategy (OR = 0.35, p = 0.047). Effects of CR over IR were similar when only diabetic patients were considered. Conclusions: Combined revascularisation can only be achieved in approximately 10% of patients. However, when successful, it results in significant improvements in wound healing and amputation-free survival over simple indirect reperfusion techniques. [ABSTRACT FROM AUTHOR]

Indoor air quality was characterized in 10 recently built energy-efficient French schools during two periods of 4.5 days. Carbon dioxide time-resolved measurements during occupancy clearly highlight the key role of the ventilation rate (scheduled or occupancy indexed), especially in this type of building, which was tightly sealed and equipped with a dual-flow ventilation system to provide air refreshment. Volatile organic compounds ( VOCs) and inorganic gases (ozone and NO2) were measured indoors and outdoors by passive techniques during the occupied and the unoccupied periods. Over 150 VOC species were identified. Among them, 27 species were selected for quantification, based on their occurrence. High concentrations were found for acetone, 2-butanone, formaldehyde, toluene, and hexaldehyde. However, these concentrations are lower than those previously observed in conventional school buildings. The indoor/outdoor and unoccupied/occupied ratios are informative regarding emission sources. Except for benzene, ozone, and NO2, all the pollutants in these buildings have an indoor source. Occupancy is associated with increased levels of acetone, 2-butanone, pentanal, butyl acetate, and alkanes. [ABSTRACT FROM AUTHOR]

Supraglacial streams are a significant part of the glacial hydrological system and important for understanding the connection between glacial hydrology and glacier dynamics. Here we determine the factors that influence the development of step-pool formation and pulsating flow in a supraglacial stream on Bylot Island, Nunavut. Results show that during the second week of a 2-week study, multiple successive rainfall events occurred, stream temperature increased and ablation decreased; which also caused stream discharge to decrease. In addition, the stream, which flowed over a 13 m high waterfall off the front of Fountain Glacier, rapidly formed 21 step-pools and began to pulsate. The pulsating phenomenon involved the complete stoppage of flow over the waterfall and the subsequent restart between 8 and 20 s later. Pulsating flow resulted from rapid changes in the streambed morphology. In particular, the formation of the step-pool sequence was caused by helical flow around meander bends and hydrologically induced slippage along transverse shear planes, evidenced by observations of high-pressure artesian flow from transverse fractures. Contrary to previous literature, this study shows that high discharge is not necessarily the cause of step-pool formation and pulsating flow within supraglacial streams. [ABSTRACT FROM PUBLISHER]

Aim The aim of this study is to determine if radiographic features are predictive of surgical difficulty of open exposure of palatal canines using a tissue sacrifice method. Materials and methods This is a prospective case series comparing features observed on preoperative panoramic radiographs and other variables to both surgical duration and the surgeons reported difficulty. Radiographic features included height, sector (overlap of adjacent incisor) and angulation of the impacted canine. Clinical variables recorded were patient age and gender, side of impaction, anaesthetic choice, if the canine was palpable, and patient cooperation. A stepwise linear regression analysis was used to relate clinical and radiographic variables to treatment duration and assessed difficulty. Inter- and intra-examiner reliability were assessed with Kappa statistics. Results Forty-nine patients with a total of 55 palatal canine exposures were included. The mean duration of exposure was 4 min and 5 s with a range of 45 s to 8 min and 50 s. Surgical duration was correlated to a subjective grade of surgical difficulty recorded on a visual analogue scale by the surgeon ( Pearson's correlation coefficient 0.76). Three predictors of increased surgical duration were identified as anaesthetic choice, height and angulation of impaction. The linear regression had an accuracy of 30.5%. Conclusions Radiographic features had a small predictive value in determining duration of open palatal canine exposure. Both increased height and angulation to the midline were associated with longer procedures. The use of local anaesthetic was associated with a longer surgical duration compared with general anaesthetic. [ABSTRACT FROM AUTHOR]

Women with antiphospholipid syndrome (APS) may have diverse pregnancy outcomes. The objective of this study was to evaluate pregnancy outcome in women with APS according to their clinical phenotype, i.e. thrombotic and obstetric APS. Eighty-three pregnancies in 67 women with APS were included in the study, including 21 with recurrent miscarriage (Group 1), 21 with late fetal loss or early delivery due to placental dysfunction (Group 2) and 41 with thrombotic APS (Group 3). Group 3 had higher rates of preterm delivery (26.8% versus 4.7%, p=0.05) than Group 1 and more small for gestational age (SGA) babies than Group 2 (39.5% versus 4.8%, p=0.003). Group 2 had significantly longer gestations compared with their pretreatment pregnancies (38.4 [28.4-41.4] versus 24.0 [18-35] weeks, p<0.0001) and 100% live birth rate after treatment with aspirin and low-molecular-weight heparin (LMWH). In conclusion, women with thrombotic APS (Group 3) have higher rates of pregnancy complications than those with obstetric APS (Groups 1 and 2). Treatment with aspirin and LMWH is associated with improved outcomes for women with previous late fetal loss or early delivery due to placental dysfunction (Group 2). [ABSTRACT FROM AUTHOR]