Deconstruction of lignocellulosic plant cell walls to fermentable sugars by biochemical means is impeded by several poorly understood ultrastructural and chemical barriers. Pretreatment is an essential step by altering the morphological and compositional characteristics of biomass to enhance the sugar release during enzymatic hydrolysis. Therefore, getting insight into this field is necessary to improve the conversion of biomass into biofuels. In this review, we highlight our recent understanding on the impact of various promising pretreatments on biomass, with emphasis on the topochemical and ultrastructural changes of plant cell walls that are related to the reduction of recalcitrance and the consequence of saccharification. It will lend support to the scientific research and development with respect to biomass conversion.
Biofuels ; Biomass ; Carbohydrates ; chemistry ; Cell Wall ; ultrastructure ; Fermentation ; Hydrolysis ; Lignin ; chemistry ; Plant Cells ; ultrastructure

OBJECTIVETo explore the feasibility for therapy of spinal cord injury (SCI) by genetic engineering neural stem cell (NSC) modified by lentiviral vector.

METHODSFollowing the construction of the genetic engineering NSC modified by lentivirus to secrete both neurotrophic factor-3 (NT-3) and green fluorescence protein (GFP), hemisection of spinal cord at the level of T10 was performed in 56 adult Wistar rats that were randomly divided into 4 groups (n = 14), namely 3 therapeutic groups and 1 control group. The therapeutic groups were dealed with NSC, genetic engineering NSC, and concentrated lentiviral supernatant which carries both GFP and NT-3, respectively. Then used fluorescence microscope to detect the transgenic expression in vitro and in vivo, migration of the grafted cells in vivo, and used the Basso, Beattie, and Bresnahan (BBB) open-field locomotor test to assess the recovery of function.

RESULTSThe transplanted cells could survive for long time in vivo and migrate for long distance. The stable transgenic expression could be detected in vivo. The hindlimb function of the injured rats in 3 therapeutic groups, especially those dealed with genetic engineering NSC, improved obviously.

CONCLUSIONIt is feasible to combine NSC with lentivirus for the repair of SCI. NSC modified by lentivirus to deliver NT-3, acting as a source of neurotrophic factors and function cell in vivo, has the potential to participate in spinal cord repair.

Animals ; Cell Line ; Embryonic Stem Cells ; transplantation ; Female ; Genetic Engineering ; methods ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; Lentivirus ; genetics ; Neurons ; transplantation ; Neurotrophin 3 ; genetics ; Rats ; Rats, Wistar ; Spinal Cord Injuries ; therapy

OBJECTIVETo understand whole body bone mineral and body composition changes in normal subjects, and study the relationship between body composition and bone mineral.

METHODS292 normal subjects aged 10-79 years old, including 140 males and 152 females, were selected to be measured bone mineral content (BMC), bone mineral density (BMD) lean and fat of whole body by dual X-ray absorptiometry (DXA). Individuals were divided into age-groups by every ten years and were analyzed by statistical methods.

RESULTSIn males, peak values of BMC, BMD, lean and fat were in the 30-39, 20-39, 30-39, 70-79 age-groups. In females, they were in the 30-39, 30-39, 30-49, 50-69 age-groups respectively. Peak values of BMC, BMD and lean were higher in males than that in females, but peak value of BMD was not significantly higher in males than that in females. Peak value of fat was higher in females than that in males. Loss of BMC and BMD for females were more pronounced than that for males. Loss of lean for males was more pronounced than that for females. There are significant positive correlation between lean, weight and bone mineral in males and females. Fat has significant effect on BMC in females only.

CONCLUSIONSThe normal bone mineral and body composition data of whole body for males and females, and the characteristic of changes with aging are provided for analyzing the relationship between bone mineral and body composition with ease.

Absorptiometry, Photon ; Adolescent ; Adult ; Aged ; Body Composition ; Bone Density ; Child ; Female ; Humans ; Male ; Middle Aged ; Sex Factors

OBJECTIVETo investigate the role of 99mTc-TRODAT-1 SPECT in diagnosis and assessing severity of idiopathic Parkinson's disease (PD).

METHODSThirty-eight patients with primary, tentative diagnosis of PD and eighteen age-matched normal controls were studied with 99mTc-TRODAT-1 SPECT imaging. The regions of interests (ROIs) were drawn manually on cerebellum (CB), occipital cortex (OC) and three transverse plane slice-views of striatums, the semiquantitative BG (background)/[(OC+CB)/2] were then calculated.

RESULTSA lower uptake of 99mTc-TRODAT-1 in striatums were displayed in thirty-six out of thirty-eight PD patients by visual inspection, compared to controls. In twenty-four PD cases with (Hoehn and Yahr scale) HYS stage I, a greater loss of DAT uptake was found in striatum and its subregions contralateral striatum to the affected limbs than in the same regions of the controls, although the striatal uptake was bilaterally reduced. Using Spearman correlation analysis showed that the reduction of the uptake ratios significantly correlated with the UPDRS in striatum and all its subregions in the PD group (P<0.05), a similar change was also found in the putamen by using the rating scale of Hoehn and Yahr (P<0.05). However, analysis of variance (ANOVA) did not show any relationship between the decreasing uptake of 99mTc-TRODAT-1 and increasing severity of PD patients, although the specific uptake of 99mTc-TRODAT-1 was continuously decreased in the striatum by visual inspection with the progress of PD from HYS stage I to III.

CONCLUSION99mTc-TRODAT-1 SPECT imaging may serve as a useful method for improving the correct diagnosis of PD. In assessing the role of 99mTc-TRODAT-1 SPECT in disease severity of PD, UPDRS can offer a comprehensive index, although the Hoehn and Yahr assessment may be available in part.

Adult ; Aged ; Corpus Striatum ; diagnostic imaging ; metabolism ; Dopamine Plasma Membrane Transport Proteins ; Feasibility Studies ; Female ; Humans ; Male ; Membrane Glycoproteins ; metabolism ; Membrane Transport Proteins ; metabolism ; Middle Aged ; Nerve Tissue Proteins ; metabolism ; Organotechnetium Compounds ; pharmacokinetics ; Parkinson Disease ; diagnostic imaging ; metabolism ; Radiopharmaceuticals ; pharmacokinetics ; Reproducibility of Results ; Sensitivity and Specificity ; Severity of Illness Index ; Tomography, Emission-Computed, Single-Photon ; methods ; Tropanes ; pharmacokinetics

BACKGROUNDOsteogenesis imperfecta (OI) is a rare bone disease and its effective treatment is relatively deficient. We tried to assess the effects of new bisphosphonate, ibandronate on children with OI.

METHODSIn this open-label, prospective, controlled study, 30 children with OI were enrolled. They received either infusions of ibandronate (2 mg) in every three months or oral calcitriol 0.25 µg daily for 24 months. All patients took 500 mg calcium plus 200 U vitamin D daily together. The endpoints were the change of annual new fracture rate (observed by case history and X ray films of spine), bone mineral density (BMD, measured by dual energy X-ray absortiometry), serum concentration of carboxy-telopeptide cross-links of type I collagen (CTX, bone resorption marker) and alkaline phosphatase (ALP, bone formation marker) during the follow-up.

RESULTSAfter the cyclic infusions of ibandronate, the annual new fracture rate was significantly decreased from 1.9 to 0.13 time, obviously lower than that of calcitriol group, which decreased from 1.8 to 1.0 time after the treatment (P < 0.001). The significant increase of BMD at the lumbar spine, femoral neck, trochanter, total hip was found in the group of ibandronate by 59.0%, 42.0%, 47.5% and 36.6% in time dependent manner (compared with the baseline, P < 0.001). The increase of BMD in ibandronate group was greater than that of calcitriol group (P < 0.001). The concentrations of ALP and CTX were obviously decreased in ibandronate group, and the reduction of CTX was more significant than that of ALP (P < 0.001). The tolerance of the children to ibandronate was quite well. Mild fever and muscle pain were found in 9 cases within 1 - 3 days after the first infusion of ibandronate, which could relieve after 1 - 2 days without special management.

CONCLUSIONSThe benefits of cyclic infusions of ibandronate to children with OI are significant because ibandronate could significantly reduce annual bone fracture rate, increase lumbar and hip BMD, preserve vertebral morphometry of patients through inhibition of bone resorption.

Bone Density Conservation Agents ; administration & dosage ; Child ; Child, Preschool ; Diphosphonates ; administration & dosage ; Female ; Humans ; Infant ; Infant, Newborn ; Infusions, Intravenous ; Male ; Osteogenesis Imperfecta ; drug therapy ; Prospective Studies