Long-term nitrogen deposition inhibits soil priming effects by enhancing phosphorus limitation in a subtropical forest.

It is widely accepted that phosphorus (P) limits microbial metabolic processes and thus soil organic carbon (SOC) decomposition in tropical forests. Global change factors like elevated atmospheric nitrogen (N) deposition can enhance P limitation, raising concerns about the fate of SOC. However, how elevated N deposition affects the soil priming effect (PE) (i.e., fresh C inputs induced changes in SOC decomposition) in tropical forests remains unclear. We incubated soils exposed to 9 years of experimental N deposition in a subtropical evergreen broadleaved forest with two types of 13 C-labeled substrates of contrasting bioavailability (glucose and cellulose) with and without P amendments. We found that N deposition decreased soil total P and microbial biomass P, suggesting enhanced P limitation. In P unamended soils, N deposition significantly inhibited the PE. In contrast, adding P significantly increased the PE under N deposition and by a larger extent for the PE of cellulose (PEcellu ) than the PE of glucose (PEglu ). Relative to adding glucose or cellulose solely, adding P with glucose alleviated the suppression of soil microbial biomass and C-acquiring enzymes induced by N deposition, whereas adding P with cellulose attenuated the stimulation of acid phosphatase (AP) induced by N deposition. Across treatments, the PEglu increased as C-acquiring enzyme activity increased, whereas the PEcellu increased as AP activity decreased. This suggests that P limitation, enhanced by N deposition, inhibits the soil PE through varying mechanisms depending on substrate bioavailability; that is, P limitation regulates the PEglu by affecting soil microbial growth and investment in C acquisition, whereas regulates the PEcellu by affecting microbial investment in P acquisition. These findings provide new insights for tropical forests impacted by N loading, suggesting that expected changes in C quality and P limitation can affect the long-term regulation of the soil PE.

Galactose-1-phosphate uridyltransferase (GalT), an in vivo-induced antigen of Actinobacillus pleuropneumoniae serovar 5b strain L20, provided immunoprotection against serovar 1 strain MS71.

GALT is an important antigen of Actinobacillus pleuropneumoniae (APP), which was shown to provide partial protection against APP infection in a previous study in our lab. The main purpose of the present study is to investigate GALT induced cross-protection between different APP serotypes and elucidate key mechanisms of the immune response to GALT antigenic stimulation. Bioinformatic analysis demonstrated that galT is a highly conserved gene in APP, widely distributed across multiple pathogenic strains. Homologies between any two strains ranges from 78.9% to 100% regarding the galT locus. Indirect enzyme-linked immunosorbent assay (ELISA) confirmed that GALT specific antibodies could not be induced by inactivated APP L20 or MS71 whole cell bacterin preparations. A recombinant fusion GALT protein derived from APP L20, however has proven to be an effective cross-protective antigen against APP sevorar 1 MS71 (50%, 4/8) and APP sevorar 5b L20 (75%, 6/8). Histopathological examinations have confirmed that recombinant GALT vaccinated animals showed less severe pathological signs in lung tissues than negative controls after APP challenge. Immunohistochemical (IHC) analysis indicated that the infiltration of neutrophils in the negative group is significantly increased compared with that in the normal control (P<0.001) and that in surviving animals is decreased compared to the negative group. Anti-GALT antibodies were shown to mediate phagocytosis of neutrophils. After interaction with anti-GALT antibodies, survival rate of APP challenged vaccinated animals was significantly reduced (P<0.001). This study demonstrated that GALT is an effective cross-protective antigen, which could be used as a potential vaccine candidate against multiple APP serotypes.

Yangxin Tongmai Formula ameliorates impaired glucose tolerance in children with Graves' disease through upregulation of the insulin receptor levels.

Graves' disease (GD) is the leading cause of hyperthyroidism, and the majority of GD patients eventually develop disorders of glucose handling, which further affects their quality of life. Yangxin Tongmai formula (YTF) is modified from a famous formula of traditional Chinese medicine for the treatment of cardiovascular diseases. In this study we investigated the potential effects of YTF in the treatment of pediatric GD patients with impaired glucose tolerance. Forty pediatric GD patients and 20 healthy children were recruited for this clinical study. Based on the glucose tolerance, the GD patients were divided into two groups: 20 patients displayed impaired glucose tolerance, while the other 20 patients displayed normal glucose tolerance. YTF was orally administered for 60 days. YTF administration significantly ameliorated the abnormal glucose tolerance and insulin sensitivity in the GD patients with impaired glucose tolerance. To determine the molecular mechanisms of this observation, the number of plasma insulin receptors was determined by ELISA. Before treatment, the fasting and postprandial levels of the insulin receptor were significantly lower in patients with impaired glucose tolerance compared with those in patients with normal glucose tolerance and healthy children. After YTF treatment, both the fasting and the postprandial circulating insulin receptor levels were upregulated, and close to those in healthy children. Therefore, YTF is a potential effective treatment to enhance glucose handling in GD children with impaired glucose tolerance.

[Root decomposition characteristics of Castanopsis carlesii stand in Wanmulin Natural Reserve of Fujian Province].

By using litter-bag method, the root decomposition characteristics of Castanopsis carlesii stand in Jian'ou Wanmulin Natural Reserve of Fujian Province were studied over two years. Three classes of roots, i.e., 0-1 mm, 1-2 mm, and 2-4 mm in diameter, were tested. During the 2-year period of decomposition, all classes roots showed a bi-phase pattern, being decomposed faster in prophase and slower in anaphase. The leaching loss of extractable substances in roots made root decomposition faster in prophase, while the increase of the acid-insoluble substances concentration in roots restrained the decomposition in anaphase. In the first year, the decomposition rate of all classes roots was controlled by the initial concentrations of their extractive substances and N; while in the second year, the decomposition rate was controlled by the initial C/N and the initial concentrations of acid-insoluble substances, N and P of the roots. During decomposition, all classes roots showed an increasing N concentration and a decreasing P concentration, and the N showed an enrichment-release pattern, while the P showed a direct release pattern.

[Total hip replacement for the treatment of Crowe IV congenital hip dislocation using small acetabular components combined with medial protrusio technique].

OBJECTIVE: To summarize the surgical technique and the clinical results of small acetabular components combined with medial protrusio technique in primary total hip arthroplasty (THA) for the treatment of Crowe type IV congenital hip dislocation (CHD). METHODS: From January 2000 to December 2005, total 14 patients (16 hips) of Crowe type IV CHD underwent cementless THA (12 unilateral, 2 bilateral) with this new technique. There were 2 males and 12 females with an average age of 49 years (range, 38 to 75 years). The indications for surgery was severe hip pain and leg length discrepancy with difficulty in walking and activating. Cup design: Duraloc (Depuy, Warsaw, USA) in 10 hips, Pressfit S II (LINK, Germany) in 6 hips. The outside diameter of the cup was 42 to 44 mm; and the thickness of the polyethylene liner was 6 to 7 mm. Total hip replacement were performed with the medial protrusion technique to stabilize the fit of a hemispherical metal cup in the acetabulum. The hip functions were evaluated by Harris hip score. The muscle strength of the gluteus medius and gait were respectively evaluated in accordance with the standards of five and four classes. RESULTS: The X-ray showed that the average superolateral bone coverage in these 16 hips (none of which had bone graft) was more than 98 percent. The cup was an average of (5.8 +/- 1.2) mm medial and (6.2 +/- 1.7) mm superior to the Ranawat triangle. The follow-up period ranged from 3 to 9 years. The Harris hip score improved from 25 to 32 preoperatively to 90 to 98 1 year postoperatively. X-ray showed that perforated area of the medial acetabulum were repaired with healed bone mud 4 to 8 months after operation. The rate of linear wear of the polyethylene liner averaged (0.10 +/- 0.03) mm each year. Until now, no aseptic loosening or osteolysis was identified around the acetabulum components, no acetabular components were revised for loosening or other reasons. CONCLUSION: Small acetabular components combined with medial protrusio technique is a simple, reliable and flexible surgical technique. Early and mid-term result in total hip arthroplasty with this technique for the treatment of Crowe type IV CHD is satisfactory.

Biomechanical analysis of functional electrical stimulation on trunk musculature during wheelchair propulsion.

BACKGROUND: The objective of this study was to examine how surface electrical stimulation of trunk musculature influences the kinematic, kinetic, and metabolic characteristics, as well as shoulder muscle activity, during wheelchair propulsion. METHODS: Eleven participants with spinal cord injury propelled their own wheelchairs on a dynamometer at a speed of 1.3 m/s for three 5-minute trials. During a propulsion trial, 1 of 3 stimulation levels (HIGH, LOW, and OFF) was randomly applied to the participant's abdominal and back muscle groups with a surface functional electrical stimulation device. Propulsion kinetics, trunk kinematics, metabolic responses, and surface electromyographic (EMG) activity of 6 shoulder muscles were collected synchronously. Kinetic, kinematic, and EMG variables were recorded during 3 time intervals (30 seconds each) within a 5-minute trial. Metabolic variables were recorded through the entire 5-minute trial. RESULTS: Participants with HIGH stimulation increased their gross mechanical efficiency (P=.05) during wheelchair propulsion. No differences were found in shoulder EMG activity, energy expenditure, and trunk motion between stimulation levels. CONCLUSION: Functional electrical stimulation on the trunk musculature has potential advantages in helping manual wheelchair users with spinal cord injury improve propulsion efficiency without placing additional demands on shoulder musculature.