Responses of soil nutrient concentrations and stoichiometry to different human land uses in a subtropical tidal wetland

We studied the impacts of anthropogenic changes in land use on the stoichiometric imbalance of soil carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in Phragmites australis wetlands in the Minjiang River estuary. We compared five areas with different land uses: P. australis wetland (control), grassland, a mudskipper breeding flat, pond aquaculture and rice cropland. Human activity has affected the elemental and stoichiometric compositions of soils through changes in land use. In general, soil C and N concentrations were lower and total soil K concentrations were higher at the sites under human land uses relative to the control site, and total soil P concentrations were generally not significantly different. The close relationship between total soil C and N concentrations in all cases, including fertilization with N, suggested that N was the most limiting nutrient in these wetlands. Lower soil N concentrations and similar soil P concentrations and higher soil K concentrations under human land-use activities suggest that human activity has increased the role of N limitation in these wetlands. Only grassland use increases soil N contents (only in the 0-10 cm of soil). Despite N fertilization, lower soil N concentrations were also observed in the rice cropland, indicating the difficulty of avoiding N limitation in these wetlands. The observed lower soil N:P ratio, together with higher soil P and K availabilities in rice croplands, is consistent with the tendency of human activity to change the competitive relationships of plants, in this case favoring species adapted to high rates of growth (low N:P ratio) and/or favoring plants with high demands for P and K. Both, soil C storage and respiration were higher in grasslands, likely due to the introduction of grasses, which led to a high density of plants, increased grazing activity and soil compaction. Soil C storage and respiration were lower under human land uses, except in the rice cropland, with respect to natural wetland. Using overall data, soil C storage and respiration were correlated, indicating that soil respiration was correlated with plant productivity. In this wetland area the impacts of different human land-uses on soil stoichiometry and C-cycle can be very different depending on the activity. Further regeneration of natural communities can be determined by the previous type of land-use.

Pathways involved in the spread of buccal carcinoma on contrast-enhanced multislice CT

OBJECTIVES

To explore how buccal carcinoma spread, using contrast-enhanced multislice CT (CEMSCT).

METHODS

We retrospectively analysed the extent of lesions in 56 patients with primary buccal squamous cell carcinoma (SCCA). Abnormal manifestations on CEMSCT at oral subsites and involved adjacent structures were documented and evaluated, which were compared with the results of surgery and histopathology.

RESULTS

Infiltration and spread to oral subsites and/or adjacent structures was confirmed in 33 patients (58.9%). The opening of the Stensen duct was the most commonly invaded oral subsite (72.7%); other sites included the gingivobuccal sulcus (60.6%), pterygomandibular raphe (54.5%), gingiva (24.2%), retromolar trigone (24.2%), orbicularis oris (18.2%) and the floor of mouth (15.2%). Of the involved adjacent structures, the buccal space was the most common site of spread (69.7%), followed by the masticatory muscles and spaces (57.6%), bone (54.5%), skin and subcutaneous fat (39.4%), pharynx (30.3%), investing fascia (15.2%) and the base of the skull (6.1%). CEMSCT manifestations of the involvement in buccal SCCAs had correlations with pathological findings (p < 0.05). The sensitivities, specificities and accuracies of two radiologists' evaluation on buccal carcinoma involvement were 50.00%, 23.21% and 73.21%; and 51.79%, 32.14% and 83.93%, respectively.

CONCLUSIONS

Buccal SCCAs could superficially and deeply spread to multiple oral subsites and/or adjacent structures. CEMSCT could delineate their spread pathways and extents.

Effectiveness of continuous and pulsed ultrasound for the management of knee osteoarthritis: a systematic review and network meta-analysis

BACKGROUND

To investigate the efficacy of continuous and pulsed ultrasound (US) in the management of knee osteoarthritis (OA).

DESIGN

This systematic review and network meta-analysis covered 12 trials in total. Electronic databases including MEDLINE, Embase and Cochrane Library were searched through to identify randomized controlled trials comparing the two modes of US with control interventions (sham or blank) or with each other. Bayesian network meta-analysis was used to integrate both the direct and indirect evidences on treatment effectiveness.

RESULTS

Pulsed US (PUS) is more effective in both pain relief and function improvement when compared with the control group; but for continuous US (CUS), there is only a significant difference in pain relief in comparison with the control group. In addition, no matter in terms of pain intensity or function at the last follow-up time point, PUS always exhibited a greater probability of being the preferred mode. However, the evidence of heterogeneity and the limitation in sample size of some studies could be a potential threat to the validity of results.

CONCLUSIONS

Our findings indicated that PUS, with a greater probability of being the preferred mode, is more effective in both pain relief and function improvement when compared with the control group. However, CUS could only be considered as a pain relief treatment in the management of knee OA. The findings also confirmed that none of these modes is dangerous.

LEVEL OF EVIDENCE

Level II, systematic review and network meta-analysis of randomized controlled trials.

Simultaneous picosecond and femtosecond solitons delivered from a nanotube-mode-locked all-fiber laser

We propose a compact nanotube-mode-locked all-fiber laser that can simultaneously generate picosecond and femtosecond solitons at different wavelengths. The pulse durations of picosecond and femtosecond solitons are measured to be ∼10.6  ps and ∼466  fs, respectively. Numerical results agree well with the experimental observations and clearly reveal that the dynamic evolutions of the picosecond and femtosecond solitons are qualitatively distinct in the intracavity. Our study presents a simple, stable, low-cost, and dual-scale ultrafast-pulsed laser source suitable for practical applications in optical communications.

Treatment of trochanteric fractures with proximal femoral nail antirotation or dynamic hip screw systems: a meta-analysis

OBJECTIVE

A meta-analysis to compare the intraoperative and postoperative outcome data for the proximal femoral nail antirotation (PFNA) and dynamic hip screw (DHS) implant systems for the treatment of patients with trochanteric fractures.

METHODS

A detailed search of several electronic databases was undertaken to identify randomized controlled trials published before 5 December 2011 that compared PFNA with DHS in patients with trochanteric fractures.

RESULTS

A quantitative meta-analysis of 11 studies including 798 patients was performed. PFNA was associated with significant reductions in duration of surgery (weighted mean difference [WMD] -21.38 min; 95% confidence interval [CI] -33.50, -9.26 min), intraoperative blood loss (WMD -176.36 ml; 95% CI -232.20, -120.52 ml), rate of fixation failure (relative risk [RR] 0.27, 95% CI 0.11, 0.62) and rate of postoperative complications (RR 0.46; 95% CI 0.31, 0.70) compared with DHS.

CONCLUSION

The use of PFNA for treatment of trochanteric fractures was found to be superior to DHS in terms of the duration of surgery, intraoperative blood loss, and rates of fixation failure and overall complications.

Usefulness of specific OA biomarkers, thrombin-cleaved osteopontin, in the posterior cruciate ligament OA rabbit model

OBJECTIVE

We undertook this study to determine whether thrombin-cleaved osteopontin (OPN) in synovial fluid (SF) represents a useful marker of osteoarthritis (OA) progression in the posterior cruciate ligament transection (PCLT) OA rabbit model.

METHOD

PCLT was performed on the right knee joints of 48 rabbits. The rabbits were then sacrificed separately at 4, 8, 16, and 24 weeks post-surgery, when the joint was harvested and macroscopic and histological assessments of articular cartilage were performed. Thrombin-cleaved OPN product in SF was determined using Western blotting and the levels were measured using an enzyme-linked immunoassay.

RESULTS

The macroscopic and histological scores for PCLT knees were already elevated 4 weeks after surgery and increased with time. Western blotting showed the presence of thrombin-cleaved OPN in SF from PCLT knees. Thrombin-cleaved OPN levels in SF were elevated at 4 weeks (P < 0.001) and were elevated peaking at 24 weeks (P < 0.00001) after PCLT compared to baseline. A positive significant correlation was found between thrombin-cleaved OPN levels and the macroscopic scores (8 weeks: ρ = 0.695, P = 0.012; 16 weeks: ρ = 0.751, P = 0.005; 24 weeks: ρ = 0.660, P = 0.020). Furthermore, the same correlation was noted between thrombin-cleaved OPN levels and the histological scores (4 weeks: ρ = 0.609, P = 0.036; 8 weeks: ρ = 0.662, P = 0.019; 16 weeks: ρ = 0.827, P = 0.001; 24 weeks: ρ = 0.813, P = 0.001).

CONCLUSION

In this rabbit model of PCLT, thrombin-cleaved OPN levels in SF appear to provide a useful marker of OA disease severity and progression.

Isolation and characterization of 19 polymorphic microsatellite loci from the topmouth gudgeon, Pseudorasbora parva

The Asiatic topmouth gudgeon, Pseudorasbora parva, is recognized as one of the most invasive fish species in many countries outside of Asia. We isolated and characterized 19 microsatellite loci from P. parva. The polymorphism of these 19 loci was tested on 40 individuals of P. parva sampled from a wild population located in Ezhou, Hubei province of China. The loci had 5 to 11 alleles, with a mean of 7.7 at each locus; 11 loci conformed to Hardy-Weinberg equilibrium. The expected and observed heterozygosities ranged from 0.237 to 0.973 and from 0.647 to 0.914, respectively. All microsatellite loci were in linkage equilibrium. These microsatellite markers are potentially useful for the assessment of population genetic structure during invasion and dispersal of P. parva in new habitats.

Mutation characteristics in type I collagen genes in Chinese patients with osteogenesis imperfecta

Osteogenesis imperfecta is normally caused by an autosomal dominant mutation in the type I collagen genes COL1A1 and COL1A2. The severity of osteogenesis imperfecta varies, ranging from perinatal lethality to a very mild phenotype. Although there have been many reports of COL1A1 and COL1A2 mutations, few cases have been reported in Chinese people. We report on five unrelated families and three sporadic cases. The mutations were detected by PCR and direct sequencing. Four mutations in COL1A1 and one in COL1A2 were found, among which three mutations were previously unreported. The mutation rates of G>C at base 128 in intron 31 of the COL1A1 gene and G>A at base 162 in intron 30 of the COL1A2 gene were higher than normal. The patients' clinical characteristics with the same mutation were variable even in the same family. We conclude that mutations in COL1A1 and COL1A2 also have an important role in osteogenesis imperfecta in the Chinese population. As the Han Chinese people account for a quarter of the world's population, these new data contribute to the type I collagen mutation map.

Serum concentrations of selected endogenous estrogen and estrogen metabolites in pre- and post-menopausal Chinese women with osteoarthritis

The purpose of this study was to investigate whether serum levels of selected endogenous estrogens and their metabolites are involved in the pathogenesis of osteoarthritis in pre- and post-menopausal women with osteoarthritis. Sixty-four patients with osteoarthritis (OA) of the knee, 48 patients with rheumatoid arthritis (RA) of the knee, and 48 healthy women were included in this study. Serum concentrations of estradiol and estrogen metabolites, such as 2- hydroxyestrone, 2-hydroxyestradiol, and 16α-hydroxyestrone, were measured by high performance liquid chromatography-mass spectrometry. Our results show that the serum concentrations of free estradiol and total 2-hydroxyestrone were significantly lower in pre-menopausal women with OA compared to the levels detected in the control groups (RA and healthy women). While serum concentrations of free and total estradiol in post-menopausal women with OA was significantly decreased compared to those of the control groups, the level of total 2-hydroxyestradiol significantly increased in postmenopausal women. Furthermore, the total 2-hydroxyestrone concentration positively correlated with the total estradiol level in pre-menopausal women with OA. In addition, the total 2- hydroxyestradiol level positively correlated with free and total estradiol levels in post-menopausal women with OA. In conclusion, estradiol and estrogen metabolites, including 2-hydroxyestrone and 2-hydroxyestradiol, were found in the sera of pre- and post-menopausal women with OA. Except for free and total estradiol deficiency, a decreased serum level of total 2- hydroxyestrone in pre-menopausal women and an increased total 2-hydroxyestradiol level in post-menopausal women with OA may also correlate with the pathogenesis of female OA.

Chronic elevated calcium blocks AMPK-induced GLUT-4 expression in skeletal muscle

Muscle contraction stimulates glucose transport independent of insulin. Glucose uptake into muscle cells is positively related to skeletal muscle-specific glucose transporter (GLUT-4) expression. Therefore, our objective was to determine the effects of the contraction-mediated signals, calcium and AMP-activated protein kinase (AMPK), on glucose uptake and GLUT-4 expression under acute and chronic conditions. To accomplish this, we used pharmacological agents, cell culture, and pigs possessing genetic mutations for increased cytosolic calcium and constitutively active AMPK. In C2C12 myotubes, caffeine, a sarcoplasmic reticulum calcium-releasing agent, had a biphasic effect on GLUT-4 expression and glucose uptake. Low-concentration (1.25 to 2 mM) or short-term (4 h) caffeine treatment together with the AMPK activator, 5-aminoimidazole-4-carboxamide-1-beta-D-ribonucleoside (AICAR), had an additive effect on GLUT-4 expression. However, high-concentration (2.5 to 5 mM) or long-term (4 to 30 h) caffeine treatment decreased AMPK-induced GLUT-4 expression without affecting cell viability. The negative effect of caffeine on AICAR-induced GLUT-4 expression was reduced by dantrolene, which desensitizes the ryanodine receptor. Consistent with cell culture data, increases in GLUT-4 mRNA and protein expression induced by AMPK were blunted in pigs possessing genetic mutations for both increased cytosolic calcium and constitutively active AMPK. Altogether, these data suggest that chronic exposure to elevated cytosolic calcium concentration blocks AMPK-induced GLUT-4 expression in skeletal muscle.