[Genetic analysis of a pedigree with primary hypertrophic osteoarthropathy]

Objective: To analyze the clinical and genetic features of primary hypertrophic osteoarthropathy (PHO). Methods: The clinical data of one Chinese pedigree of PHO, namely pachydermoperiostosis (PDP) were collected.Blood samples were drawn from the propositus and other family members.DNA was extracted and genetic analysis was performed by Sanger method after PCR.The sequencing data of HPGD gene exons were analyzed by alignment with sequences from National Center for Biotechnology Information (NCBI). Results: (1)The propositus represented symptoms in childhood including clubbing fingers, sweating, seborrhea, joint swelling and so on.Periosteal thickening and bone hyperplasia were found by X-ray. (2)The homozygous mutation named c. 310_311delCT in propositus, which located in the third exon of HPGD, was identified.His parents carried the same heterozygous mutation, while his sister did not inherit any mutation of this gene. (3)The prediction of spatial structure of proteins revealed that the mutant proteins had about 60% discrepancy compared with wild-type protein, losing a lot of motifs responsible for combining with coenzyms and prostaglandin E(2), as well as active sites of enzymes. Conclusions: The clinical manifestations and imaging findings are helpful to diagnose PDP. Moreover gene mutation analysis ensures the diagnosis.The structure and function of HPGD gene mutation induce 15-hydroxy prostaglandin dehydrogenase mutation, contributing to the occurrence of PDP.

Room-temperature CO Thermoelectric Gas Sensor based on Au/Co3O4 Catalyst Tablet

A carbon monoxide (CO) thermoelectric (TE) gas sensor was fabricated by affixing a Au/Co₃O₄ catalyst tablet on a TE film layer. The Au/Co₃O₄ catalyst tablet was prepared by a co-precipitation and tablet compression method and its possible catalytic mechanism was discussed by means of x-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, x-ray photoelectron spectroscopy, temperature-programmed reduction of hydrogen, Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller analysis. The optimal catalyst, with a Au content of 10 wt%, was obtained at a calcination temperature between 200 and 300 °C. The small size of the Au nanoparticles, high specific surface, the existence of Co³⁺ and water-derived species contributed to  high catalytic activity. Based on the optimal Au/Co₃O₄ catalyst tablet, the CO TE gas sensor worked at room temperature and showed a response voltage signal (ΔV) of 23 mV, high selectivity among hydrogen and methane, high stability, and a fast response time of 106 s for 30 000 ppm CO/air. In addition, a CO concentration in the range of 5000-30 000 ppm could obviously be detected and exhibited a linear relationship with ΔV. The CO TE gas sensor provides a promising option for the detection of CO gas at room temperature.

Mobilising elementary and secondary school students for tuberculosis case finding in Anhui, China

OBJECTIVES

To evaluate the implementation of a FIDELIS (Fund for Innovative DOTS Expansion through Local Initiatives to Stop TB) project in Anhui Province, China.

DESIGN

A survey card was designed for students to identify individuals who might have tuberculosis (TB) in their family. Teachers provided health education on TB before distributing the survey cards. Survey cards identifying individuals with respiratory symptoms for ≥3 weeks were sent by the teachers to village doctors who were trained to visit symptomatic individuals and advise them to undergo sputum examination. Data were routinely collected in the implementation of the FIDELIS project, and quarterly reports from the National Tuberculosis Programme were analysed. The detection of new smear-positive TB cases before and after FIDELIS, as well as with and without FIDELIS, were compared.

RESULTS

In the first year, a total of 2 387 405 students were involved and 23 079 symptomatic individuals were examined, among whom 2307 (10.3%) were diagnosed with smear-positive TB. Case detection in FIDELIS counties increased by a factor of 3.5 during the FIDELIS period compared with before FIDELIS, and that in non-FIDELIS counties by a factor of 3.1 (P = 0.001).

CONCLUSION

It was feasible to massively mobilise students for TB case finding through collaboration between the health care and education systems.

Enhanced ultraviolet emission from Au/Ag-nanoparticles@MgO/ZnO heterostructure light-emitting diodes: A combined effect of exciton- and photon- localized surface plasmon couplings

Localized surface plasmon (LSP)-enhanced ultraviolet light-emitting diodes (LEDs) based on a Au/MgO/ZnO metal/insulator/semi- conductor heterostructure were fabricated by embedding Ag nanoparticles (Ag-NPs) into MgO dielectric layer. A ~6-fold electroluminescence (EL) enhancement was achieved from the Ag-NPs decorated device. Time-resolved spectroscopy studies, as well as analogue simulation and theoretical estimation based on experimental data, reveal that the internal quantum efficiency and light extraction efficiency of the heterojunction LED are increased ~3-fold and ~2-fold, respectively, as a result of the introduction of Ag LSPs. This result indicates that the observed EL enhancement originates from a combined effect of both exciton-LSP coupling and photon-LSP coupling.

Molecular characterization of Cryptosporidium spp. in pre-weaned calves in Shaanxi Province, north-western China

Cryptosporidium, a worldwide protozoan parasite, is one of the most common causes of diarrhoea in humans and animals. The aim of the present study was to determine Cryptosporidium species/genotypes in pre-weaned calves in Shaanxi Province using PCR and sequencing based on the small subunit rRNA gene. A total of 258 faecal samples were collected from pre-weaned calves in 19 different farms from six areas in Shaanxi Province, north-western China. Cryptosporidium infection was detected in 14 of 19 farms (73.7 %), with a total prevalence of 20.2 % (52/258). Both dairy and Qinchuan (beef) cattle were found with Cryptosporidium infection. Three Cryptosporidium species, namely Cryptosporidium bovis (n = 26), Cryptosporidium andersoni (n = 14) and Cryptosporidium ryanae (n = 12), were detected in pre-weaned calves in Shaanxi Province, with C. bovis (in 12 farms) identified as the most common species on cattle farms. Two additional and previously unknown C. ryanae genotypes, CRTypes III and IV, were observed in the present study. However, the zoonotic species, Cryptosporidium parvum, was not detected in this study, which suggested a low zoonotic potential in Cryptosporidium-infected pre-weaned calves in this province.

Improved methane production from waste activated sludge with low organic content by alkaline pretreatment at pH 10

Sludge with low organic content always results in an unsatisfactory performance, even failure of anaerobic digestion. The alkaline pretreatment effect on anaerobic digestion of sludge with low organic content has seldom been studied although it gives many benefits for sludge with high organic content. In this study the influence of alkaline pretreatment (pH 10, an effective alkaline pH) on the solubilization and methane production from waste activated sludge (WAS) with low organic content was investigated. Results from biochemical methane potential (BMP) experiments showed that anaerobic biodegradability of WAS was greatly improved by alkaline pretreatment at pH 10. Methane production from the current WAS under conditions of pretreatment time 4 h and digestion time 15 d was 139.6 mL/g VS (volatile solids), much higher than that from the unpretreated WAS with digestion time of 20 d (75.2 mL/g VS). Also, the solubilization of WAS was significantly accelerated by alkaline pretreatment. Mechanism exploration indicated that the general activities of anaerobic microorganisms, specific activities of key enzymes and the amounts of methanogens were enhanced by alkaline pretreatment at pH 10, showing good agreement with methane production.

First Report of Nigrospora oryzae Causing Leaf Spot of Cotton in China

Cotton (Gossypium hirsutum L.) is widely cultivated for the important economic value of the fiber. In the summer of 2011, a leaf spot of cotton plants cv. Wanza40 was observed in 11 fields (total of about 4 ha) in Qianshan County in southwest Anhui Province, China. Approximately 30% of the plants in each field were symptomatic. Affected plants exhibited brown to reddish, irregular foliar lesions, each with a brown border near the vein of the leaves. A sign of fungal infection was a dark leaf mold observed on lesions on the abaxial surface of leaves. Sections of symptomatic leaf tissues were surface-sterilized (in 75% ethanol for 30 s, then 1% NaOCl for 1 min), rinsed three times in sterile distilled water, and plated onto potato dextrose agar (PDA). A fungus consistently recovered from symptomatic leaf samples produced colonies that were initially white and then became grayish brown with the onset of sporulation. Black, spherical to subspherical, single-celled conidia (10 to 12 × 14 to 16 μm) were borne on a hyaline vesicle at the tip of each conidiophore. Morphological characteristics of the fungus were similar to that of Nigrospora oryzae (2). The internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) from a representative strain of the fungus, AHC-1, was amplified using the primers ITS1/ITS4 (4) and sequenced (GenBank Accession No. JQ864579). The ITS sequence had 99% identity with >553 bp of the ITS sequence of an N. oryzae isolate (GenBank Accession No. EU918714.1). On the basis of morphological data and ITS rDNA sequence, the isolate was determined to be N. oryzae. A pathogenicity test was performed on detached, young leaves of 4-month-old healthy cotton plants of cv. Wanza40. Six leaves were inoculated by placing a colonized agar piece (5 mm in diameter) from 7-day-old cultures of the fungus on pushpin-wounded leaves. Another six leaves treated with sterile PDA plugs served as a negative control treatment. Leaves were incubated in petri dishes and maintained at 25°C in a growth chamber programmed for 12 hours of fluorescent white light/day. After 5 days, brown to black lesions were observed on all inoculated leaves, whereas no symptoms developed on control leaves. N. oryzae was consistently reisolated from symptomatic leaves but not from the control leaves. N. oryzae is a weak pathogen on a wide range of plants, and has been described as the causal agent of lint rot on cotton (1,3), but to our knowledge this is the first report of N. oryzae causing a leaf spot of cotton in China. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , April 8, 2012. (2) H. J. Hudson. Trans. Br. Mycol. Soc. 46:355, 1963. (3) A. J. Palmatter et al. Plant Dis. 87:873, 2003. (4) T. J. White et al. In: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

First Report of Leaf Blight Caused by Nigrospora sphaerica on Curcuma in China

Curcuma (family Zingiberaceae) is commonly cultivated for the use of rhizomes within traditional Chinese medicines. In October 2009 and 2010, severe leaf blight was observed on Curcuma wenyujin Y.H. Chen & C. Ling (4) in fields located in Ruian, China. The area of cultivation in Ruian encompasses 90% of the production in Zhejiang Province. Disease incidence was approximately 90% of plants observed in affected fields. Early symptoms were yellow-to-brown, irregular-shaped lesions on the leaf margin or tip. After several days, lesions expanded along the mid-vein until the entire leaf was destroyed. Blighted leaves turned grayish to dark brown and withered, and severely affected plants died. Eight fungal isolates were recovered from symptomatic C. wenyujin leaves, collected from eight different fields, on potato dextrose agar (PDA). These fungal colonies were initially white, becoming light to dark gray and produced black, spherical to subspherical, single-celled conidia (14 to 17 × 12 to 15 μm), which were borne on a hyaline vesicle at the tip of the conidiophores. On the basis of these morphological features, the isolates appeared to be similar to Nigrospora sphaerica (2). Strain ZJW-1 was selected as a representative for molecular identification. Genomic DNA was extracted from the isolate, and the internal transcribed spacer (ITS) region of the ribosomal DNA (ITS1-5.8S-ITS2) was amplified using ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') primers (3). The ITS region was further cloned and sequenced (GenBank Accession No. JF738028) and was 99% identical to N. sphaerica (GenBank Accession No. FJ478134.1). On the basis of morphological data and the ITS rDNA sequence, the isolate was determined to be N. sphaerica. Pathogenicity tests were conducted on four leaves of four C. wenyujin plants by placing agar pieces (5 mm in diameter) from 8-day-old cultures on pushpin-wounded leaves. An equal number of control plants were wounded and inoculated with noncolonized PDA agar pieces. Plants were placed in moist chambers at 25°C with a 12-h photoperiod. Brown-to-black lesions were observed on wounded leaves after 3 days and expanded to an average of 56 × 40 mm 15 days after inoculation. No symptoms developed on the control leaves. The pathogen was reisolated from the margins of necrotic tissues but not from the controls. The pathogen has been reported as a leaf pathogen on several hosts worldwide (1). To our knowledge, this is the first report of N. sphaerica as a leaf pathogen of C. wenyujin in China. Future research will focus primarily on management of this disease. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases, Systematic Mycology and Microbiology Laboratory, USDA-ARS, Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , March 31, 2011. (2) E. W. Mason. Trans. Brit. Mycol. Soc. 12:152, 1927. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (4) J. Zhao et al. Molecules 15:7547, 2010.

[Determination of 1, 1-dichloro-l-nitroethane in air of workplaces by gas chromatography]

OBJECTIVE

To establish a gas chromatography method for detecting the concentration of 1,1-dichloro-1-nitroethane in air of workplaces.

METHOD

1,1-dichloro-1-nitroethane in air of workplaces was collected by activated charcoal tube, absorbed using carbon disulfide and analyzed by Gas Chromatography (FID) with FFAP capillary column.

RESULTS

The linear rang of 1,1-dichloro-1-nitroethane in this method was 4.0-858.2 microg/ml, the linear regression formula was Y = 283X-1076, the correlation coefficient was 0.9999, the lowest detection concentration was 0.4 mg/m3 (3L sampling air), the relative standard deviation (RSD) was 1.8%-4.1%, the desorption efficiency was 88.5%-90.6%, the breakthrough volume was > 0.7 mg, the sampling efficiency was 100%, the samples could be kept at ambient temperature for at least 7 days.

CONCLUSION

The indicators of this method were conformed to the requirements of "Guide for establishing occupational health standards--Determination methods of air chemicals in workplace". This method could be used to detect 1,1-dichloro-1-nitroethane in air of workplaces.

Differential gene expression and functional analysis of pit cells from regenerating rat liver

Hepatic pit cells are a population of large granular lymphocytes that substantially contribute to hepatic immunity. Studies have proven that pit cells have a role in liver regeneration, but the details of the relationship between pit cells and liver regeneration is not clear at present. We subjected rats to a two-third hepatectomy; pit cells with high purity were obtained with Percoll density centrifugation and immunomagnetic bead methods, and the changes in mRNA levels in pit cells from the regenerating liver were monitored up to 168 h using a Rat Genome 230 2.0 Array composed of 25,020 distinct rat liver cDNA clones. Of the 25,020 genes analyzed, 612 known and 358 unknown genes were identified to be associated with liver regeneration. The 612 known genes are classified into up-regulation and down-regulation patterns based on the expression levels; they primarily participate in at least 23 biological activities based on gene ontology analysis. Together with gene function enrichment analysis, cytokines and a growth factor-mediated pathway in pit cells were activated at an early phase of liver regeneration; pit cell proliferation occurred from 24-72 h after liver hepatectomy; the machinery of pit cell differentiation commenced early and came into play late; an immune/inflammatory response was enhanced late. Expression pattern analysis of functionally classified genes in pit cells can give insights into the relationship between pit cells and liver regeneration.

Emergy evaluation and economic analysis of three wetland fish farming systems in Nansi Lake area, China

Emergy and economic methods were used to evaluate and compare three fish production models, i.e., cage fish farming system, pond intensive fish rearing system and semi-natural extensive pond fish rearing system, in Nansi Lake area in China in the year 2007. The goal of this study was to understand the benefits and driving forces of selected fish production models from ecological and economic points of view. The study considered input structure, production efficiency, environmental impacts, economic viability and sustainability. Results show that the main difference among the three production systems was the emergy cost for fish feed associated with their feeding system, i.e., feeding on natural biomass such as plankton and grass or on commercial feedstock. As indicated by EYR, ELR and ESI, it can be clearly shown that the intensive production model with commercial feed is not a sustainable pattern. However, the point is that more environmentally sound patterns do not seem able to provide a competitive net profit in the short run. The intensive pond fish farming system had a net profit of 2.57E+03 $/ha, much higher than 1.27E+03 $/ha for cage fish farming system and slightly higher than 2.37E+03 $/ha for semi-natural fish farming system. With regard to the drivers of local farmer's decisions, the accessibility of land for the required use and investment ability determine the farmer's choice of the production model and the scale of operation, while other factors seem to have little effect. Theoretically, the development of environmentally sustainable production patterns, namely water and land conservation measures, greener feed as well as low waste systems is urgently needed, to keep production activities within the carrying capacity of ecosystems. Coupled emergy and economic analyses can provide better insight into the environmental and economic benefits of fish production systems and help solve the problems encountered during policy making.

Availability of second-line drugs and anti-tuberculosis drug susceptibility testing in China: a situational analysis

OBJECTIVE

To assess the availability of second-line drugs (SLDs) and the use of drug susceptibility testing (DST) results for the treatment of tuberculosis (TB) in China.

DESIGN

Cross-sectional survey in 4675 health care facilities, 1960 of which have a dedicated TB clinic, in 12 provinces in China.

RESULTS

More than 70% of TB clinics at the provincial and prefecture levels had at least one SLD available compared to 41.8% of facilities at the county/district level. The proportion of facilities at provincial, prefecture and county levels with any fluoroquinolone was respectively 74.1%, 64.9% and 34.5%. Sputum culture was performed at 6.0% of TB clinics at the county level, 37.5% at the prefecture and 59.3% at the provincial levels, while DST was performed only at the prefecture (28.6%) and provincial (44.4%) levels. Only 18% of the facilities that used SLDs for the treatment of multidrug-resistant TB (MDR-TB) based treatment regimens on DST results.

CONCLUSION

SLDs are widely available in China for the treatment of both TB and other infectious diseases. To prevent the development of Mycobacterium tuberculosis resistance to SLDs, the availability of SLDs should be limited and they should be used with caution in the treatment of MDR-TB.

Targeted deletion of NF-kappaB p50 diminishes the cardioprotection of histone deacetylase inhibition

We have recently demonstrated that the inhibition of histone deacetylases (HDAC) protects the heart against ischemia-reperfusion (I/R) injury. The mechanism by which HDAC inhibition confers myocardial protection remains unknown. The purpose of this study is to investigate whether the disruption of NF-kappaB p50 would eliminate the protective effects of HDAC inhibition. Wild-type and NF-kappaB p50-deficient mice were treated with trichostatin A (TSA; 0.1 mg/kg ip), a potent inhibitor of HDACs. Twenty-four hours later, the hearts were perfused in Langendorff model and subjected to 30 min of ischemia and 30 min of reperfusion. Inhibition of HDACs by TSA in wild-type mice produced marked improvements in left ventricular end-diastolic pressure, left ventricular rate pressure product, and the reduction of infarct size compared with non-TSA-treated group. TSA-induced cardioprotection in wild-type animals was absent with genetic deletion of NF-kappaB p50 subunit. Notably, Western blot displayed a significant increase in nuclear NF-kappaB p50 and the immunoprecipitation demonstrated a remarkable acetylation of NF-kappaB p50 at lysine residues following HDAC inhibition. EMSA exhibited a subsequent increase in NF-kappaB DNA binding activity. Luciferase assay demonstrated an activation of NF-kappaB by HDAC inhibition. The pretreatment of H9c2 cardiomyoblasts with TSA (50 nmol/l) decreased cell necrosis and increased in cell viability in simulated ischemia. The resistance of H9c2 cardiomyoblasts to simulated ischemia by HDAC inhibition was eliminated by genetic knockdown of NF-kappaB p50 with transfection of NF-kappaB p50 short interfering RNA but not scrambled short interfering RNA. These results suggest that NF-kappaB p50 acetylation and activation play a pivotal role in HDAC inhibition-induced cardioprotection.

VEGF gene therapy for the survival of transplanted fat tissue in nude mice

The objective of this study was to determine the effects of adenovirus-mediated vascular endothelial growth factor (Ad-VEGF) on the angiogenesis and survival of free-fat tissue transplantation in nude mice. Thirty 6-week-old CD-1 nude male mice were injected with 1ml fat tissue (harvested by suction-assisted lipectomy from the breast of humans) in the subcutaneous of scalp and were randomised into three groups of 10 animals each. Group 1 was the study group, in which Ad-VEGF was mixed with transplanted fat tissue and injected into mice. In group 2, adenovirus-mediated green fluorescent protein (Ad-GFP) gene was mixed with transplanted fat tissue and injected into the mice. In group 3, normal saline alone was used. Both group 2 and group 3 are control groups. The animals were euthanised 15 weeks after the procedure. The fat survival weight and volume of the study group were significantly greater than those of two control groups (p<0.05). Light microscopical examination of haematoxylin and eosin-stained slides of the dissected fat 15 weeks after injection was performed in group 1 and group 2. Less cyst formation and fibrosis, indicating improved quality of the injected fat, can be obtained by the addition of Ad-VEGF. Vascular density was evaluated at the microvascular level through the use of light microscopic sections of the central part of the fat tissue at 15 weeks after injection by von Willebrand factor staining. Histological evaluation showed that capillary density increased markedly in the study group mice. Mice of the study group disclosed significantly higher VEGF protein levels detected by ELISA assay of plasma samples obtained from the mice after the fat injection (day 1, 4, 7 and 28; p<0.01) at each time point than the mice of the two control groups. The findings reported in this study indicate that the VEGF gene therapy can enhance the survival and the quality of grafted fat tissue, which may be due to induction of angiogenesis.

[Expression of FasL and apoptosis in pulmonary tissue of rats exposed to silica at different time]

OBJECTIVE

To investigate the change of the expression of the FasL receptor and apoptosis in the pathology of silicosis of the rats exposed to silica and their roles.

METHODS

Ninety-six wistar rats were randomizedly divided into the control group and the experimental group. The silicotic animal model was established by the direct tracheal instillation of silica into rat lungs surgically. The control rats underwent directly tracheal instillation of saline into lungs surgically. Eight rats from each group were sacrificed at different days. The expression of FasL receptor in the tissue of the model rats was detected by tissuechip microarray and immunohistochemistry and the cell apoptosis induced by silica was determined by TdT-mediated dUTP nick end-labeling method. The integral optical density of positive cells were quantitatively analyzed using Image-Pro Plus Version 4.5 for windows.

RESULTS

The expression of FasL in the lung tissue of the model rats on the 7th, the 14th, the 21st, and the 28th day was significantly higher than that in the control group (P < 0.05), and peaked at the 14th day after exposure to silica. Apoptotic cells in the lung tissue of the model rats on the 1st, the 3rd, the 7th, the 14th, the 21st, and the 28th day were significantly more than those in the control group, and peaked at the 7th and the 14th day after exposure to silica.

CONCLUSION

Silica can lead to apoptosis in lung tissues. FasL is expressed in all kinds of cells in the pulmonary tissues of the rats exposed to silica and leads to apoptosis. From the 7th day to 14th day, inflammatory cells dominate in apoptotic cells.

The impact of migrants on the epidemiology of tuberculosis in Beijing, China

SETTING

Tuberculosis (TB) services in the Municipality of Beijing, China.

OBJECTIVE

To evaluate the impact of migrants on the epidemiology and management of TB in Beijing.

DESIGN

Comparison of information on permanent residents and migrants from routine reports of TB cases registered in Beijing from 1993 to 2005.

RESULTS

From 1993 to 2005, there was a steady rise in the proportion of migrants among TB cases notified in Beijing, from approximately one in 10 cases to one in three cases. The results of treatment in migrant cases of TB over the period 1997-2004 were unsatisfactory. The proportion of cases cured among permanent residents was 90.6%, compared with only 37.0% of cases among migrants.

CONCLUSION

Migrants pose a challenge to TB services in Beijing. Special attention must be given to them by the National Tuberculosis Programme to address these challenges.

[Induced expression of the variable region of AMA-1 from Plasmodium falciparum]

OBJECTIVE

To express the variable region of AMA-1 gene from Plasmodium falciparum in Escherichia coli.

METHODS

Genomic DNA of FCC1/HN was used as template and the variable region of AMA-1 gene was amplified by polymerase chain reaction(PCR). The PCR products were digested by endonuclease BamH I and Hind III, cloned into pBlu2KSP. The nucleotide sequences of the variable region of AMA-1 gene were determined by sequencing. The AMA-1 gene fragment was subcloned into plasmid pQE, expressed in E. coli and induced by IPTG. The fusion product as identified by SDS-PAGE gel electrophoresis and Western blotting were proceeded with anti-AMA-1 sera from rabbit.

RESULTS

The size of the variable region of AMA-1 gene from FCC1/HN was 506 bp and encoded 168 amino acids. On SDS-PAGE gel dyed with Coomassie brilliant blue R250, no specific protein band can be discerned, but Western blotting proceeded with anti-AMA-1 sera from rabbit demonstrated that the specific protein band was about 23.0 kDa.

CONCLUSION

The variable region of AMA-1 gene from FCC1/HN was able to be expressed in E. coli and analysis of Western blotting demonstrated that the AMA-1 fussion protein contained specific antigenic epitopes.

Thalidomide modulation of the immune response in female B6C3F1 mice: a host resistance study

Previously, we have reported that thalidomide (Thd) treatment can modulate the immune responses in female B6C3F1 mice. The present study was designed to evaluate whether or not these immunomodulatory responses were of sufficient magnitude to alter host resistances in a number of pathogen and tumor models. B6C3F1 mice were treated intraperitoneally with Thd (30-150 mg/kg) for 14 or 28 days, then inoculated with either Plasmodium yeolii, PYB6 fibrosarcoma tumor cells, B16F10 melanoma tumor cells, Listeria monocytogenes, or Streptococcus pneumoniae. Significant dose-dependent protection against B16F10 and L. monocytogenes was observed in mice that were treated with Thd. Furthermore, time course study using bacterial colony-forming units per spleen and liver as the endpoints indicated that the protective effect of Thd on host resistance to L. monocytogenes was time-dependent. In contrast, Thd treatment did not affect host resistance to P. yeolii, S. pneumoniae and PYB6 tumor. Additionally, the effect of Thd on the phagocytic function of the mononuclear phagocyte system (MPS) was evaluated following intravenous injection of 51Cr-labeled sRBCs. The overall phagocytic activity of MPS was not significantly altered by Thd treatment. In conclusion, these results demonstrate that Thd immunomodulation altered host resistance to B16F10 and L. monocytogenes; and selective modulation of Thd on the immune system may be responsible for the pathogen or tumor-specific effect of this compound.

Occupational and environmental risk factors for respiratory symptoms in rural Beijing, China

The aim of the present study was to determine the effects of occupational and environmental exposure on respiratory symptoms in adults in rural Beijing, China. Thirty randomly selected villages in the counties of Shunyi and Tongxian, 50 km north and east, respectively, of the city of Beijing, China, participated in this study. Village doctors interviewed all residents aged > or = 15 yrs and completed the International Union Against Tuberculosis and Lung Disease Questionnaire on Bronchial Symptoms translated into Chinese with added questions on smoking and occupational and environmental exposure. Of the eligible population, 22,528 adults (98%) took part. The prevalence of all respiratory symptoms, i.e. asthma-like symptoms, asthma attacks in the last 12 months, chronic cough and chronic phlegm, was low. Significant determinants for respiratory symptoms were age, sex, smoking and county of residence. A dose-dependent relationship was found between cumulative cigarette consumption and prevalence of respiratory symptoms. After adjusting for these variables, exposure to insecticides and fertilisers significantly increased the risk of most of the respiratory symptoms, whereas exposure to indoor air pollution from domestic fuels did not. Exposure to chemicals such as insecticides and fertilisers contributed independently to the risk of respiratory symptoms in rural Beijing, China.

Sodium metasilicate hypersensitivity in BALB/c mice

BACKGROUND

Sodium metasilicate (SMS) is a key ingredient for a number of industrial and consumer products. Although little is known about potential for this chemical to cause allergic reactions, a similar silicate compound, sodium silicate, was reported to elicit IgE-mediated contact urticaria.

OBJECTIVE

The aim of this study was to evaluate the potential for sodium metasilicate to elicit an allergic response in female BALB/c mice after dermal exposure.

METHODS

The primary irritancy assay (IA), local lymph node assay (LLNA), and a mouse ear swelling test (MEST) were used to evaluate the hypersensitivity response elicited by SMS exposure. An evaluation of lymph node subpopulations, cytokine mRNA expression, and serum IgE levels was also conducted.

RESULTS

SMS caused significant dermal irritation at concentrations >or=6% and an allergic response after mice were sensitized with 4% SMS then challenged with 6% SMS in the MEST. Lymph node cell proliferation was not observed in the LLNA after treatment with SMS (2% to 6% SMS). Increases in lymph node cellularity, the percentage of B cells, and the expression of certain cytokine mRNAs were observed in mice treated with SMS. Changes in the concentration of serum IgE after SMS treatment, however, were not observed.

CONCLUSIONS

SMS appears to elicit a chemical hypersensitivity response in mice, as indicated by the MEST, but not by the LLNA. Increases in auricular lymph node cellularity, the percentage of B cells, and certain cytokine mRNAs support classifying SMS as a weak chemical allergen.