Monthly distribution of ammonia-oxidizing microbes in a tropical bay.

Ammonia oxidation, performed by ammonia-oxidizing archaea (AOA) and bacteria (AOB), plays a critical role in the cycle of nitrogen in the ocean. For now, environmental variables controlling distribution of ammonia-oxidizing microbes are still largely unknown in oceanic environments. In this study, we used real-time quantitative PCR and high-throughput sequencing methods to investigate the abundance and diversity of AOA and AOB from sediment and water in Zhanjiang Bay. Phylogenic analysis revealed that the majority of AOA amoA sequences in water and sediment were affiliated with the genus Nitrosopumilus, whereas the Nitrosotalea cluster was only detected with low abundance in water. Nitrosomonas and Nitrosospira dominated AOB amoA sequences in water and sediment, respectively. The amoA copy numbers of both AOA and AOB varied significantly with month for both sediment and water. When water and sediment temperature dropped to 17-20°C in December and February, respectively, the copy number of AOB amoA genes increased markedly and was much higher than for AOA amoA genes. Also, AOA abundance in water peaked in December when water temperature was lowest (17-20°C). Stepwise multiple regression analyses revealed that temperature was the most key factor driving monthly changes of AOA or AOB abundance. It is inferred that low water temperature may inhibit growth of phytoplankton and other microbes and so reduce competition for a common substrate, ammonium.

Spatio-Temporal Variations in the Abundance and Community Structure of Nitrospira in a Tropical Bay.

Nitrospira is the most diverse genus of nitrite-oxidizing bacteria, and its members are widely spread in various natural and engineered ecosystems. In this study, the phylogenetic diversity of Nitrospira and monthly changes of its abundance from Zhanjiang Bay were investigated. Phylogenetic analysis showed that among 58 OTUs with high abundance, 74% were not affiliated with any previously described Nitrospira species, revealing a previously unrecognized diversity of coastal Nitrospira. The abundances of both Nitrospira and Nitrospina exhibited a significantly monthly change. During most of the months, abundance of Nitrospina was greater than that of Nitrospira. In particle-attached communities, either abundance of Nitrospina or Nitrospira was highly correlated with that of ammonia-oxidizing archaea (AOA), whereas abundance of ammonia-oxidizing bacteria was only highly correlated with that of Nitrospina. In free-living communities, either abundance of Nitrospina or Nitrospira was correlated only with that of AOA. These results suggest that both Nitrospira and Nitrospina can be involved in nitrite oxidation by coupling with AOA, but Nitrospina may play a greater role than Nitrospira in this tropical bay.

The effect of melanin-free extract from Sepia esculenta ink on lipid peroxidation, protein oxidation and water-holding capacity of tilapia fillet during cold storage.

BACKGROUND: Preservative effect of melanin-free extract of Sepia esculenta ink (MFESI) on Sparus latus fillet has been verified in our previous work. This study aims to further approach the mechanism of MFESI for extending the shelf-life of fish fillet during cold storage. Tilapia fillets were treated with different dosage of MFESI (0, 15, 25 and 35 mg/ml) and packed with preservative film for succedent cold-storage at 4 °C for scheduled time. Contents of total volatile basic nitrogen and sulfydryl and carbanyl groups were measured for evaluating protein oxidation. Malondialdehyde contents were measured for estimating lipid peroxidation and loss of water was used to determine water-holding capacity of fillet. RESULTS: The data indicated that MFESI not only possessed certain degree of antioxidant capacity in vitro, also lengthened shelf-life of tilapia fillet in cold-storage condition. Apart from 15 mg/ml, both 25 and 35 mg/ml of MFESI obviously prevented lipid and protein from oxidation and reduced loss of water from tilapia fillets, and the latter was more effective than the former. CONCLUSION: MFESI can repress lipid peroxidation and protein oxidation and reduce water loss, maintain the tilapia fillets quality and, thus, it could be an effective and natural preservative for extending the shelf-life of tilapia fillets during cold storage.

Inhibition of acrolein-induced autophagy and apoptosis by a glycosaminoglycan from Sepia esculenta ink in mouse Leydig cells.

In our recent reports, a squid ink polysaccharide (SIP) was found having preventive activity against cyclophosphamide induced damage in mouse testis and ovary. Here we further reveal the regulative mechanism of SIP against chemical toxicity on testis. Leydig cells exposed to acrolein (ACR) underwent apoptosis at 12h and 24h. Before apoptosis, cells occurred autophagy that was confirmed by high autophagic rate and Beclin-1 protein content at 3h. PI3K/Akt and p38 MAPK signal pathways involved in the regulatory mechanisms. These outcomes of ACR were recovered completely by SIP, which was demonstrated by attenuated disruption of redox equilibrium and increased testosterone production, through suppressing ACR-caused autophagy and apoptosis regulated by PI3K/Akt and p38 MAPK signal pathways in Leydig cells. Summarily, autophagy occurred before apoptosis caused by ACR-activated p38 MAPK and PI3K/Akt pathways were blocked by SIP, resulting in survival and functional maintenance of Leydig cells.

Atorvastatin alleviates renal ischemia-reperfusion injury in rats by promoting M1-M2 transition.

Acute kidney injury (AKI) often occurs as a result of ischemia-reperfusion (IR). Previous studies have demonstrated that inflammation is an important contributor to AKI. Atorvastatin (ATO) possesses anti­inflammatory properties and has been demonstrated to exert protective effects against renal IR injury (IRI). However, the underlying mechanism requires further study. In the present study, a rat model of renal IRI was successfully established. Consistent with the results of a previous study, ATO significantly attenuated IRI, which was supported by a decrease in serum creatinine and an increase in creatinine clearance rate, as well as alleviated pathological alterations in renal tubular cells. There are two types of activated macrophages: Proinflammatory M1 and anti­inflammatory M2 macrophages, which have been demonstrated to exert contributory and protective effects on IRI, respectively. The present study demonstrated that treatment with ATO significantly decreased M1 macrophage density and increased M2 macrophage density, as compared with the IR group. In addition, it is well known that M1 macrophages can be induced by T helper 1 cytokines, including tumor necrosis factor (TNF)­α and interferon (IFN)­Î³, whereas M2 macrophages can be induced by peroxisome proliferator-activated receptor (PPAR)­Î³. The present study indicated that ATO treatment significantly decreased the expression levels of TNF­α and IFN­Î³, and increased PPAR­Î³ expression. In conclusion, ATO may ameliorate renal IRI by promoting M1­M2 transition. Furthermore, ATO­mediated macrophage polarization in rats with renal IRI may be associated with the downregulation of TNF­α and IFN­Î³, and the upregulation of PPAR-γ.

[Synthesis and characterization of CO-3(2-) doping nano-hydroxyapatite].

CO3(2-) doping is an effective method to increase the biological activity of nano-hydroxyapatite (n-HA). In the present study, calcium nitrate and trisodium phosphate were chosen as raw materials, with a certain amount of Na2CO3 as a source of CO-3(2-) ions, to synthesize nano-carbonate hydroxyapatite (n-CHA) slurry by solution precipitation method. The structure and micro-morphology of n-CHA were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR) and Raman spectroscopy (RS). The results revealed that the synthetic n-HA crystals are acicular in nanometer scale and have a crystal size of 20-30 nm in diameter and 60-80 nm in length, which are similar to natural bone apatite. And the crystallinity of n-CHA crystals decreases to the increment of CO3(2-). Samples with more CO3(2) have composition and structure more similar to the bone apatite. The value of lattice parameters a decreases, value of c increases, and c/a value increases with the increase in the amount of CO3(2-), in accordance with crystal cell parameters change rule of type B replacement. In the AB mixed type (substitution OH- and PO4(3-)) CHA, IR characteristic peak of CO3(2-) out-of-plane bending vibration appears at 872 cm(-1), meanwhile, the asymmetry flexible vibration band is split into band at 1 454 cm(-1) and band at 1 420 cm(-1), while weak CO3(2)-peak appears at 1 540 cm(-1). CO3(2-) Raman peak of symmetric stretching vibration appears at 1 122 cm(-1). CO3(2-) B-type (substitution PO4(3-)) peak appeared at 1 071 cm(-1). Through the calculation of integral area ratio of PO4(3-)/ CO3(2-), OH-/CO3(2-), and PO4(3-)/OH-, low quantity CO3(2-) is B-type and high quantity CO3(2-) is A-type (substitution OH-). The results show that the synthesized apatite crystals are AB hybrid substitued nano-carbonate hydroxyapatite, however B-type replacement is the main substitute mode. Due to similarity inthe shape, size, crystal structure and growth mode, the synthesized apatite crystals can be called a kind of bone-like apatite.

[Efficacy of continuous positive airway pressure therapy upon resistant hypertension in patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To investigate the efficacy and possible mechanism of continuous positive airway pressure (CPAP) therapy upon blood pressure in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) and resistant hypertension (RH). METHODS: Thirteen OSAHS patients with RH were recruited. Before and after 3-month CPAP therapy, their blood pressures at 10:00 PM, 2:00 AM and 6:00 AM were measured and their morning plasma concentrations of aldosterone (ALD) and plasma renin activity (PRA) tested at supine position with radioimmunoassay. RESULTS: Compared with blood pressure parameters at pre-CPAP therapy, there was a significant decrease in blood pressure before sleep at the end of 3-month CPAP therapy [(135.5 +/- 2.8)/(84.2 +/- 4.6) vs (152.2 +/- 19.2)/(98.9 +/- 15.6) mm Hg, P < 0.01], at night during sleep [ (133.1 +/- 2.4)/(81.5 +/- 4.6) vs (156.6 +/- 19.4)/(102.8 +/- 16.6) mm Hg, P < 0.01] and in the early morning [(151.5 +/- 3.0)/(81.2 +/- 3.2) vs (172.1 +/- 23.7)/(98.1 +/- 6.5) mm Hg, P < 0.01]. Comparison of plasma concentrations of ALD and PRA before and after 3-month CPAP therapy indicated that there was a significant difference in ALD [(538 +/- 42) vs (408 +/- 53) pmol/L, P < 0.01] but not significantly different in PRA [(0.27 +/- 0.14) microg x L(-1) x h(-1) vs (0.20 +/- 0.12), P = 0.221]. CONCLUSIONS: CPAP therapy could significantly improve RH and plasma ALD concentration. Elevated plasma ALD concentration is possibly involved in the pathogenesis of RH in OSAHS patients.

Effect of continuous positive airway pressure treatment on serum adiponectin level and mean arterial pressure in male patients with obstructive sleep apnea syndrome.

BACKGROUND: Recent research suggested that obstructive sleep apnea syndrome (OSAS) might be independently associated with hypoadiponectinemia, which was linked to some complications of OSAS, such as hypertension, diabetes, etc. This study was conducted to investigate the effect of continuous positive airway pressure (CPAP) treatment on changes of both serum adiponectin levels and mean arterial pressure and their possible links in male OSAS patients. METHODS: Twenty-three adult male patients with moderate-to-severe OSAS but without obesity, coronary heart disease and diabetes were recruited. Their blood samples were collected and morning mean arterial pressure (MAP) was measured before CPAP treatment and on day 3, 7, 14 of CPAP treatment respectively. The serum adiponectin concentration was tested with radioimmunoassay. RESULTS: Compared with the serum adiponectin level before CPAP treatment, no significant change was found in OSAS patients on day 3 and day 7 of CPAP treatment (P > 0.05). It was not until day 14 of CPAP treatment did a significant elevation in serum adiponectin level occur (P < 0.01). Meanwhile, the MAP showed no statistically significant difference among its levels before CPAP, on day 3 and day 7 of CPAP treatment (P > 0.05). However, on day 14 of CPAP treatment, a significantly lower MAP than that obtained before treatment was observed (P < 0.05). CONCLUSIONS: CPAP treatment can gradually reverse hypoadiponectinemia and reduce MAP in OSAS patients. Hypoadiponectinemia might be involved in the pathogenesis of OSAS-mediated hypertension.

[Effect of hospice care on the quality of life and psychological state of aged mortal inpatients].

OBJECTIVE: To investigate the influence of hospice care on the life quality and psychological state of aged mortal inpatients. METHODS: Seventy-six aged patients were randomly divided into 2 groups (n=38). The research group was treated with hospice care, while the control group was treated with conventional nursing. Before and after more than one month of the interference, the quality of life, social support, satisfied degree, anxiety, and depression mood were investigated. RESULTS: All the indexes, such as total scale of life quality, appetite, spirit, sleep, family comprehension and coordination, recognition of cancer, attitude to therapy, and facial expression of the mortal inpatients after the interference, were raised and higher than those of the controls (P<0.05 or P<0.01). Life satisfaction index and the total scale of social support and subjective support, utilization ratio of support were raised and higher than those of the controls (P<0.05 or P<0.01). The level of anxiety and depression was decreased and lower than the control (P<0.05 or P<0.01). CONCLUSION: Hospice care can raise the life quality, subjective support, utilization ratio of support and life satisfaction of aged mortal inpatients. It could decrease the negative mood, such as anxiety and depression and improve the psychological state.

Anti-hepatitis B activities of ganoderic acid from Ganoderma lucidum.

Ganoderic acid, from Ganoderma lucidum, at 8 microg/ml inhibited replication of hepatitis B virus (HBV) in HepG2215 cells over 8 days. Production of HBV surface antigen and HBV e antigen were 20 and 44% of controls without ganoderic acid. Male KM mice were significantly protected from liver injury, induced with carbon tetrachloride, by treatment with ganoderic acid at 10 mg and 30 mg/kg x d (by intravenous injection) 7 days. Ganoderic acid at the same dosage also significantly protected the mice from liver injury induced by M. bovis BCG plus lipopolysaccharide (from Escherichia coli 0127:B8).

[In vitro inhibitory efects on HBsAg and HBeAg secretion of 3 new components produced by Ganoderma lucidum in the medium contained Radix sophorae flavescentis extract].

In order to enhance the medical effects of Ganoderma lucidum submergedly cultured broth, the aqueous extract of Radix sophorae flavescentis, a traditional Chinese medicine, was added into the cultivation medium of G. lucidum. The organic acids were extracted with ethanol, chloroform, 5% NaHCO3 and chloroform in turn from the cultured broth of Ganoderma lucidum which cultivation medium contained Radix sophorae flavescentis extract. Six new components were separated from the organic acids with preparative HPLC. Their inhibitory effects on HBsAg and HBeAg secretion of HBV DNA transferred HepG2 cell (2.2.15 cell) were investigated. The results indicate that 3 components of the six have significant inhibitory effects on the antigen secretion.

A quantum chemical and statistical study of ganoderic acids with cytotoxicity against tumor cell.

A set of molecular properties (variables) of 24 ganoderic acids with cytotoxicities against Meth-A tumor cells was calculated by the molecular orbital semi-empirical method AM1 and ChemPropStd. Pattern recognition techniques, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to reduce dimensionality and investigate which subset of variables could be more effective for classifying the ganoderic acids according to their degree of cytotoxicities against tumor cells. The PCA and HCA studies showed that EHOMO (highest occupied molecular orbital energy), Mulliken electronegativity (chi), electronic energy (Eel), log P (octanol/water partition coefficient), and Connolly molecular area (MA) are the most important variables for the classification between the ganoderic acids with higher and lower cytotoxicities against tumor cells.