Purification and Characterization of a Keratinase from a Feather-Degrading Bacillus licheniformis Strain

A keratinase was isolated from the culture medium of feather-degrading Bacillus licheniformis PWD-1 by use of an assay of the hydrolysis of azokeratin. Membrane ultrafiltration and carboxymethyl cellulose ion-exchange and Sephadex G-75 gel chromatographies were used to purify the enzyme. The specific activity of the purified keratinase relative to that in the original medium was approximately 70-fold. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and Sephadex G-75 chromatography indicated that the purified keratinase is monomeric and has a molecular mass of 33 kDa. The optimum pH and the pI were determined to be 7.5 and 7.25, respectively. Under standard assay conditions, the apparent temperature optimum was 50 degrees C. The enzyme is stable when stored at -20 degrees C. The purified keratinase hydrolyzes a broad range of substrates and displays higher proteolytic activity than most proteases. In practical applications, keratinase is a useful enzyme for promoting the hydrolysis of feather keratin and improving the digestibility of feather meal.

Induction of tumoricidal activity in mouse peritoneal macrophages by ginseng polysaccharide

This study examined the effects of ginseng polysaccharide (GPS) on mouse peritoneal macrophage (PM)-mediated cytotoxicity towards K562, HL-60, or KG1alpha cells. GPS had no direct effect on killing of tumor cells. However, when mouse PMs were treated with GPS, cytotoxic activity against K562, HL-60, or KG1alpha cells was significantly induced. In addition, phagocytic activity was enhanced in GPS-treated mouse PMs compared to the control. The expressions of CD(68), ACP and alpha-ANE in mouse PMs were increased by the treatment with GPS. Moreover, the levels of cytokines, including tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), IL-6 were increased and the production of nitric oxide (NO) was enhanced. Taken together, these results suggest that GPS possess a potent antitumor activity by stimulating macrophage and a potentiality as an immunomodulator against diseases such as cancer.

Total saponins of Panax ginseng (TSPG) promote erythroid differentiation of human CD34+ cells via EpoR-mediated JAK2/STAT5 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Total saponins of Panax ginseng (TSPG), main constituents extracted from Panax ginseng, a highly valued traditional Chinese medicine, have been shown to be an effective agent on hematopoiesis.

OBJECTIVE

To investigate the effect and mechanism underlying in which TSPG promote human CD34(+) hematopoietic stem and progenitor cells to differentiate into erythroid-lineage cells.

MATERIALS AND METHODS

The effect of TSPG on erythroid differentiation of purified CD34(+) cells derived from umbilical cord blood (UCB) was determined by methylcellulose assay system and colorimetry for hemoglobin content. The changes of EpoR expression in umbilical cord blood mononuclear cells (UCB-MNCs) and purified CD34(+) cells were detected with Western blotting and flow cytometry, respectively, and observed under laser scanning confocal microscope (LSCM). RT-PCR was performed to examine EpoR mRNA expression in CD34(+) cells. The effects of TSPG-pretreatment on Epo-induced JAK(2) and STAT(5) tyrosine phosphorylation were analyzed by immunoprecipitation.

RESULTS

The addition of TSPG (20-70 mg/L) increased the colony formation rate of BFU-E. TSPG (50 mg/L) alone used significantly increased the hemoglobin content, the addition of AG490 evidently reduced TSPG-induced elevation of hemoglobin content. TSPG increased the expression of EpoR on the surface membrane of CD34(+) cells but did not change the expression of EpoR in total UCB-MNCs. TSPG also increased the expression of EpoR mRNA in CD34(+) cells. TSPG markedly enhanced Epo-induced tyrosine phosphorylation of JAK(2) and STAT(5) in UCB-MNCs.

CONCLUSION

These findings suggest that TSPG may enhance the erythroid differentiation of hematopoietic stem and progenitor cells via Epo/EpoR-mediated JAK(2)/STAT(5) signaling pathway.

Superconductivity induced by Ni doping in SmFe(1-x)Ni(x)AsO

Superconductivity with a T(c) of about 10 K is observed in the Ni-doped SmFe(1-x)Ni(x)AsO system. The measurements of resistivity and magnetic susceptibility show that the spin-density wave (SDW) order is quickly suppressed with increasing Ni content, and superconductivity emerges as x≥0.04. T(c)(mid) shows a maximum of 10.8 K at x = 0.06, and it drops to lower than 2 K as x>0.12. Meanwhile, the upper critical field (H(c2)(0)) is estimated to be about 40 T for the optimally-doped sample (x = 0.06). The normal state thermopower is negative for all the Ni-doped samples, indicating that an electron-type charge carrier dominates in the transport properties. Moreover, the magnitude of the room-temperature thermopower increases with increasing Ni content, and then shows a broad peak around x = 0.06. We found that there is an obvious correlation between the anomalously enhanced thermopower and superconductivity. A phase diagram is derived based on the transport measurements and a dome-like T(c)(x) curve is established.

Expression of receptor activator of nuclear factor-kappaB ligand by B cells in response to oral bacteria

INTRODUCTION

We investigated receptor activator of nuclear factor-kappaB ligand (RANKL) expression by B lymphocytes during early and late aspects of the immune response to Aggregatibacter actinomycetemcomitans, a gram-negative, anaerobic bacterium associated with aggressive periodontal disease.

METHODS

Expression of messenger RNA transcripts (tumor necrosis factor-alpha, Toll-like receptors 4 and 9, interleukins 4 and 10, and RANKL) involved in early (1-day) and late (10-day) responses in cultured rat splenocytes was examined by reverse transcription-polymerase chain reaction (RT-PCR). The immune cell distribution (T, B, and natural killer cells and macrophages) in cultured rat splenocytes and RANKL expression in B cells were determined by flow cytometric analyses. B-cell capacity for induction of osteoclast differentiation was evaluated by coculture with RAW 264.7 cells followed by a tartrate-resistant acid phosphatase (TRAP) activity assay.

RESULTS

The expression levels of interleukins 4 and 10 in cultured cells were not changed in the presence of A. actinomycetemcomitans until cultured for 3 days, and peaked after 7 days. After culture for 10 days, the percentages of B and T cells, the overall RANKL messenger RNA transcripts, and the percentage of RANKL-expressing immunoglobulin G-positive cells were significantly increased in the presence of A. actinomycetemcomitans. These increases were considerably greater in cells isolated from A. actinomycetemcomitans-immunized animals than from non-immunized animals. RAW 264.7 cells demonstrated significantly increased TRAP activity when cocultured with B cells from A. actinomycetemcomitans-immunized animals. The addition of human osteoprotegerin-Fc to the culture significantly diminished such increases.

CONCLUSION

This study suggests that B-lymphocyte involvement in the immune response to A. actinomycetemcomitans through upregulation of RANKL expression potentially contribute to bone resorption in periodontal disease.

Occurrence of matrix-bound phosphine in intertidal sediments of the Yangtze Estuary

This study investigated the levels and potential transformation of matrix-bound phosphine in the intertidal sediments (0-5cm) of the Yangtze Estuary. Matrix-bound phosphine concentrations in sediments ranged from 0.65 to 3.25ngkg(-1), with an annual average of 1.53ngkg(-1). In freshwater sediments, the concentrations of matrix-bound phosphine were significantly higher than in the brackish sediments. The maximum concentrations of matrix-bound phosphine appeared in July (1.17-3.25ngkg(-1)), followed by May (0.92-3.01ngkg(-1)), November (0.65-2.41ngkg(-1)) and January (0.51-1.42ngkg(-1)). Matrix-bound phosphine derived probably from the mechanochemical reduction of apatite-bound phosphate and the microbial conversion of organic phosphorus in the intertidal sediments. Its spatial and seasonal distributions, however, were regulated by salinity and sediment temperature. Compared with other aquatic systems (e.g. rivers, lakes and coastal seas), a low level of matrix-bound phosphine was observed in the intertidal sediments, probably implicating a relatively rapid turnover of phosphine in the system.

A multicentre study assessing the prevalence of sensitizations in patients with asthma and/or rhinitis in China

BACKGROUND

The prevalence of sensitization in patients with asthma and rhinitis in mainland China remains unclear.

OBJECTIVE

Our aim was to estimate the prevalence of allergy in patients with respiratory allergic diseases such as asthma and/or rhinitis attending respiratory clinics within mainland China. The study also investigated regional and annual differences in the prevalence and pattern of sensitization among the patients in China.

METHOD

A cross-sectional survey was performed in 6304 patients suffering from asthma and/or rhinitis in 17 cities from 4 regions of China. Patients completed a standardized questionnaire asking for the presence of respiratory and allergic symptoms. They also underwent skin prick tests with 13 common aeroallergens.

RESULTS

Among the 6304 patients, 4545 (72.1%) had at least one positive skin prick reaction. The overall prevalence of positive skin prick responses was 59.0% for Dermatophagoides farinae, 57.6% for Dermatophagoides pteronyssinus, 40.7% for Blomia tropicalis, 16.1% for American cockroach, 14.0% for dog, 11.5% for Blatella germanica, 11.3% for Artemisia vulgaris, 10.3% for cat, 6.5% for Ambrosia artemisifolia, 6.3% for mixed mould I, 4.4% for mixed mould IV, 3.5% for mixed grass pollen and 2.2% for mixed tree pollen. Sensitizations to common allergens varied widely between geographical areas and demonstrated unique pattern in patients by stratification with age groups, with asthma and/or rhinitis. Severity of rhinitis and asthma was significantly correlated with skin index of reactivity to Artemisia vulgaris, Ambrosia artemisifolia and to D. pteronyssinus, D. farinae and Blomia tropicalis respectively (P < 0.001). Positive reactivity to the tested allergens and concomitant reactivity to multiple allergens including to house dust mites and Blomia tropicalis was markedly increased in patients with both asthma and rhinitis.

CONCLUSION

House dust mites were the most prevalent allergens in patients with asthma and/or rhinitis in China. There were significant differences in patterns of sensitizations in patients from different geographical areas, age groups as well as asthma and/or rhinitis.

'I felt I have grown up as an adult': caregiving experience of children affected by HIV/AIDS in China

BACKGROUND

The growing global epidemic of HIV/AIDS has a significant impact on the lives of both people living with HIV/AIDS and their family members including children. Children of parents with HIV/AIDS may experience an increased responsibility of caregiving in family. However, limited data are available regarding the caregiving experience and its impact on psychosocial well-being among these children. This study was designed to address these issues by using qualitative data collected from children affected by HIV/AIDS in China.

METHODS

The qualitative data were collected in 2006 in rural central China, where many residents were infected with HIV/AIDS through unhygienic blood collection procedures. In-depth individual interviews were conducted by trained interviewers with 47 children between 8 and 17 years of age who had lost one or both parents to AIDS.

RESULTS

Findings of this study suggest that many children affected by AIDS had experienced increased responsibilities in housework and caregiving for family members. Such caregiving included caring for self and younger siblings, caring for parents with illness and caring for elderly grandparents. Positive impacts from children's participation in family caregiving included personal growth and emotional maturity. Negative consequences included physical fatigue, psychological fear and anxiety and suboptimal schooling (dropping out from school, repeated absence from school and unable to concentrate in class).

CONCLUSION

While the increased caregiving responsibilities among children reflected some cultural beliefs and had some positive effect on personal growth, the caregiving experience generally negatively effected the children's physical and mental health and schooling. The findings in the current study suggest that community-based caregiving support is necessary in areas with high prevalence of HIV and limited resources, especially for the families lacking adult caregivers. In addition, social and psychological support should be made available for children participating in family caregiving.

Sibling separation and psychological problems of double AIDS orphans in rural China - a comparison analysis

OBJECTIVE

We investigated the psychological impact of sibling separation among children who lost both of their parents to AIDS and were placed in group care or kinship care settings in rural China.

METHODS

Comparative analysis of cross-sectional survey data among 155 children among whom 96 experienced sibling separation. Trauma symptoms (Anxiety, Depression, Anger, Post-traumatic stress, Dissociation, Sexual concerns) were compared between the AIDS orphans who experienced sibling separation and those who did not using analysis of variance and multivariate analysis of covariance.

RESULTS

Among the participants (47.7% girls) with an average age of 12.4 years, univariate and multivariate analyses showed that separation from siblings was associated with significantly higher scores in anxiety, depression, anger and dissociation before or after controlling for gender, age, care arrangement, number of household replacement, trusting relationship with the current caregivers and perceived quality of current living condition. Sibling separation among orphans was not associated with level of post-traumatic stress and sexual concerns.

CONCLUSION

AIDS orphans separated from their siblings suffered from increased psychological distress compared with those who remained with their siblings. The data in the current study suggest that care arrangement for AIDS orphan should include accommodating the siblings together or providing them with opportunities for frequent contact and/or communication with each other. Appropriate psychological counselling should be given to those orphans experiencing sibling separation.

Granulocyte colony stimulating factor decreases brain amyloid burden and reverses cognitive impairment in Alzheimer's mice

Granulocyte colony stimulating factor (G-CSF) is a multi-modal hematopoietic growth factor, which also has profound effects on the diseased CNS. G-CSF has been shown to enhance recovery from neurologic deficits in rodent models of ischemia. G-CSF appears to facilitate neuroplastic changes by both mobilization of bone marrow-derived cells and by its direct actions on CNS cells. The overall objective of the study was to determine if G-CSF administration in a mouse model of Alzheimer's disease (AD) (Tg APP/PS1) would impact hippocampal-dependent learning by modifying the underlying disease pathology. A course of s.c. administration of G-CSF for a period of less than three weeks significantly improved cognitive performance, decreased beta-amyloid deposition in hippocampus and entorhinal cortex and augmented total microglial activity. Additionally, G-CSF reduced systemic inflammation indicated by suppression of the production or activity of major pro-inflammatory cytokines in plasma. Improved cognition in AD mice was associated with increased synaptophysin immunostaining in hippocampal CA1 and CA3 regions and augmented neurogenesis, evidenced by increased numbers of calretinin-expressing cells in dentate gyrus. Given that G-CSF is already utilized clinically to safely stimulate hematopoietic stem cell production, these basic research findings will be readily translated into clinical trials to reverse or forestall the progression of dementia in AD. The primary objective of the present study was to determine whether a short course of G-CSF administration would have an impact on the pathological hallmark of AD, the age-dependent accumulation of A beta deposits, in a transgenic mouse model of AD (APP+ PS1; Tg). A second objective was to determine whether such treatment would impact cognitive performance in a hippocampal-dependent memory paradigm. To explain the G-CSF triggered amyloid reduction and associated reversal of cognitive impairment, several mechanisms of action were explored. (1) G-CSF was hypothesized to increase activation of resident microglia and to increase mobilization of marrow-derived microglia. The effect of G-CSF on microglial activation was examined by quantitative measurements of total microglial burden. To determine if G-CSF increased trafficking of marrow-derived microglia into brain, bone marrow-derived green fluorescent protein-expressing (GFP+) microglia were visualized in the brains of chimeric AD mice. (2) To assess the role of immune-modulation in mediating G-CSF effects, a panel of cytokines was measured in both plasma and brain. (3) To test the hypothesis that reduction of A beta deposits can affect synaptic area, quantitative measurement of synaptophysin immunoreactivity in hippocampal CA1 and CA3 sectors was undertaken. (4) To learn whether enhanced hippocampal neurogenesis was induced by G-CSF treatment, numbers of calretinin-expressing cells were determined in dentate gyrus.

Quantum well states in two-dimensional gold clusters on MgO thin films

The electronic structure of ultrasmall Au clusters on thin MgO/Ag(001) films has been analyzed by scanning tunneling spectroscopy and density functional theory. The clusters exhibit two-dimensional quantum well states, whose shapes resemble the eigenstates of a 2D electron gas confined in a parabolic potential. From the symmetry of the highest occupied (HOMO) and lowest unoccupied molecular orbital (LUMO) of a particular cluster, its electron filling and charge state is determined. In accordance with a Bader charge analysis, aggregates containing up to 20 atoms accumulate one to four extra electrons due to a charge transfer from the MgO/Ag interface. The HOMO-LUMO gap is found to close for clusters containing between 70 and 100 atoms.

Supersolid behavior in confined geometry

We have carried out torsional oscillator and heat capacity measurements on solid 4He samples grown within a geometry which restricts the helium to thin (150 microm) cylindrical disks. In contrast with previously reported values from Rittner and Reppy of 20% nonclassical rotational inertia for similar confining dimensions, 0.9% nonclassical rotational inertia (consistent with that found in bulk samples and samples embedded in porous media) was observed in our torsional oscillator cell. In this confined geometry, the heat capacity peak is consistent with that found in bulk solid samples of high crystalline quality.

Association of GCKR rs780094, alone or in combination with GCK rs1799884, with type 2 diabetes and related traits in a Han Chinese population

AIMS/HYPOTHESIS

The GCKR rs780094 and GCK rs1799884 polymorphisms have been reported to be associated with dyslipidaemia and type 2 diabetes in white Europeans. The aim of this study was to replicate these associations in Han Chinese individuals and to identify the potential mechanisms underlying these associations.

METHODS

The single nucleotide polymorphisms rs780094 and rs1799884 were genotyped in a population-based sample of Han Chinese individuals (n = 3,210) and tested for association with risk of type 2 diabetes and related phenotypes.

RESULTS

The GCKR rs780094 A allele was marginally associated with reduced risk of type 2 diabetes (OR 0.85, 95% CI 0.73-1.00, p value under an additive model [p((add))] = 0.05) and significantly associated with reduced risk of impaired fasting glucose (IFG) or type 2 diabetes (OR 0.86, 95% CI 0.77-0.96, p([add]) = 0.0032). It was also significantly associated with decreased fasting glucose and increased HOMA of beta cell function (HOMA-B) and fasting triacylglycerol levels (p([add]) = 0.0169-5.3 x 10(-6)), but not with HOMA of insulin sensitivity (HOMA-S). The associations with type 2 diabetes and IFG remained significant after adjustment for BMI, while adjustment for HOMA-B abolished the associations. The GCKR rs780094 was also associated with obesity and BMI, independently of its association with type 2 diabetes. The GCK rs1799884 A allele was significantly associated with decreased HOMA-B (p([add]) = 0.0005), but not with type 2 diabetes or IFG. Individuals with increasing numbers of risk alleles for both variants had significantly lower HOMA-B (p([add]) = 5.8 x 10(-5)) in the combined analysis.

CONCLUSIONS/INTERPRETATION

Consistent with observations in white Europeans, the GCKR rs780094 polymorphism contributes to the risk of type 2 diabetes and dyslipidaemia in Han Chinese individuals. In addition, we showed that the effect on type 2 diabetes is probably mediated through impaired beta cell function rather than through obesity.

Monocyte differentiation is controlled by MyD88 after mouse orthotopic lung transplantation

In lung grafts, ischemia-reperfusion signals rapidly induce the recruitment and differentiation of host monocytes into macrophages and dendritic cells. The nature of ischemia-reperfusion signals are antigen independent, but have been hypothesized to initiate Toll-like receptor (TLR) and interleukin (IL)-1R-mediated signaling pathways that are thought to potentiate alloimmune responses. We wondered whether MyD88, an adaptor molecule critical for both TLR and IL-1R-mediated inflammatory responses, regulated monocyte differentiation in a mouse model of vascularized orthotopic lung transplantation. Orthotopic left lung transplants were performed in the following syngeneic combinations: CD45.1(+) B6 --> CD45.2(+) MyD88(-/-) and CD45.1(+) B6 --> CD45.2(+) B6. One day later, recipient-derived dendritic cells and macrophage numbers were assessed in the bronchiolar lavage by FACS analysis. Compared with the bronchiolar lavage of wildtype recipients, MyD88(-/-) recipients had lower numbers of dendritic cells in lung graft airways that were of recipient origin. Lower numbers of newly differentiated lung graft dendritic cells was coincident with the appearance of higher numbers of undifferentiated monocytes in the lung airways of MyD88(-/-) recipients as compared with wild-type recipients. Moreover, adoptive transfer experiments demonstrated that MyD88(-/-) monocytes were poorer at differentiating into lung dendritic cells as compared with wild-type monocytes. Taken together, these data show that MyD88 regulates graft-infiltrating monocyte differentiation and suggests a mechanism by which TLR/IL-1R-signaling pathways control adaptive responses in lung allografts through controlling monocyte fate.

Safety evaluation of polydextrose in infant formula using a suckling piglet model

Oligosaccharides, the third largest component in human milk, are virtually absent from cow's milk and most infant formula. Prebiotic carbohydrates like polydextrose (PDX) have been proposed as surrogates for human milk oligosaccharides. Safety assessments of novel infant formula ingredients include dose-response experiments in appropriate neonatal animal models such as the suckling pig. To further substantiate the safety of the ingredient, one-day old pigs were fed a cow's milk-based formula supplemented with PDX (1.7, 4.3, 8.5 or 17 g/L) for 18 days (n=13/dose) and compared to appropriate control (unsupplemented formula; n=13) and reference groups (day 0 pigs, and sow-reared pigs; n=13). Growth rate, formula intake, stool consistency, behavior score, blood chemistry and hematology, relative organ weights (% of body weight), tissue morphology (i.e. liver, kidney and pancreas) and pancreas biochemistry did not differ among formula-fed pigs (P>0.1). Polydextrose mimicked other prebiotic carbohydrates and had no adverse effect at the highest tested level 17.0 g PDX/L, equivalent to a dose of 8.35 g/kg of body weight per day.