Abnormal ore pressure mechanism of working face under the influence of overlying concentrated coal pillar

Shenfu Dongsheng coal field is a cross-century energy base which is developed and constructed in China. In recent years, some mines have successively entered to the coal seam of the second layer. Due to the reasons of early mining, many coal pillars are left in the coal seam of the first layer, resulting in the phenomenon of strong ore pressure in the mining range before and after the coal pillar in the lower coal seam and even causing the buckling accident. In order to solve such safety problems, this paper takes the 22,307 working face in Bulianta coal mine as the research object, adopts physical similarity simulation experiment and theoretical analysis to systematically study the overlying rock characteristics and abnormal ore pressure manifestation mechanism of shallow and close coal seam in different working stages. The results show that the roof overburden of the key layer in the lower group bends and sinks when the coal pillar is mined, resulting in the activation and instability of the "masonry beam" structure formed by the roof of the upper coal seam. When the coal pillar is discharged, the residual concentrated coal pillar and the room type coal pillar are unstable under the action of high supporting stress, resulting in shear failure of the inter-layer rock in the upper part of 22,307 working face, causing the strong dynamic pressure of the working face to appear and then leading to the buckling accident. The working resistance of the support in each stage is obtained by establishing the structure diagram of the overlying rock under each stage and the corresponding mechanical structure model. Finally, the working resistance required by the support in the mining stage under the goaf is 16,692.6 kN, the working resistance required by the support in the coal pillar stage is 19,692.6 kN, the working resistance required by the support in the mining stage under the concentrated coal pillar is 13,150.6 kN, and the working resistance required by the support in the coal pillar stage is 19,215.6 kN.

Molecular mechanism of electroacupuncture treatment on oxaliplatin-induced peripheral neurotoxicity in rats

Oxaliplatin (L-OHP) has been widely used in the treatment of various tumors, especially in colorectal cancer. The mechanism of peripheral neurotoxicity induced by L-OHP (OIPN) is unclear and current therapeutic options only serve to alleviate the symptoms rather than prevent OIPN. To observe the effects of electroacupuncture (EA) stimulation on OIPN in rats, rats were randomly divided into the control group, OIPN model group, and OIPN + EA group. To establish OIPN rat models, a single intraperitoneal injection with 10 mg/kg L-OHP in the OIPN model rats. Rats in the control group received a single intraperitoneal injection with 0.9% lactose. From the third day after establishing OIPN models, the rats were treated with EA. Cold allodynia and heat sensitivity were assessed using the acetone drop and the Hargreaves method, respectively. Pathological changes in nerves were detected using hematoxylin and eosin (H&E) staining and transmission electron microscopy. Related mRNA and protein expression levels were measured by real-time polymerase chain reaction (PCR) and western blotting from 14 days after establishing OIPN models. Our results showed that L-OHP significantly increased the sensitivity to cold allodynia and nervous injury, which were ameliorated after EA treatment. The expression of glucocorticoid receptor alpha (GR-α) and B-cell lymphoma 2 (Bcl-2) was significantly decreased and that of Bax was significantly increased in sciatic nerve of OIPN model rats compared with control rats. However, EA treatment significantly inhibited L-OHP-induced protein expressions in rats. Moreover, compared with the control rats, the nucleus NF-κBp65 levels were significantly increased, while the cytoplasm NF-κBp65 levels were significantly decreased, which were reversed by EA treatment. In conclusion, EA treatment may reduce peripheral neurotoxicity induced by L-OHP through regulating related protein expression.

Use of Potentially Inappropriate Medications in People With Dementia in Vietnam and Its Associated Factors

This study examined the use of potentially inappropriate medicines that may affect cognition (PIMcog) in people with dementia and its associated factors. Medical records of all outpatients with dementia attending a tertiary hospital in Vietnam between January 1, 2015, and December 31, 2016, were examined. Medicine use was assessed against a list of PIMcog. Variables associated with having a PIMcog were assessed using a multiple logistic regression. Of the 128 patients, 41% used a PIMcog, 39.1% used cholinesterase inhibitors (CEIs) concomitantly with anticholinergics, and 18% used antipsychotics. The number of hospital visits (adjusted odds ratio [OR]: 1.08; 95% confidence interval [CI]: 1.02-1.16) and number of treating specialists (adjusted OR: 0.61; 95% CI: 0.45-0.83) were associated with PIMcog use. This study highlights a high-level use of medicines that can further impair cognition or reduce the effectiveness of CEIs in people with dementia. Efforts to improve quality use of medicines for this population are warranted.

Comparative Evaluation of Different Membranes for the Construction of an Artificial Liver Support System

During the past decades, many technological improvements have been made in the construction of extracorporeal liver support systems. Among these achievements, membranes of artificial capillary system, used as substrates of hepatocyte growth, aroused our interest in their application for the construction of bioreactors. The present paper studied the comparison of hepatocyte growth and function on six different membranes. Four of them are cellulose based membranes, Cuprophan, Hemophan, Cellulose acetate, and Bioflux; two are synthetic polymer SPAN and Polysulphone. Human hepatoma cell line SMMC-7721, with moderately differentiated hepatocyte-specific functions, was inoculated into the hollow fiber cartridges. These cells were allowed to attach and to grow over these membranes. It was found that there existed differences in hepatocyte immobilization and growth among these membranes. They influenced the growth and functions of hepatoma cells in vitro to some extent. These results show that membrane is an important factor in the construction of capillary membrane bioreactors for artificial liver support.

Advances of recurrent risk factors and management of choledocholithiasis

Gallstone disease is a common and frequently occurring disease in human, and it is the main disease among the digestive system diseases. The incidence of gallstone disease in western countries is about 5%-22%, and common bile duct stones (CBDS) accounts for 8%-20%. CBDS easily lead to biliary obstruction, secondary cholangitis, pancreatitis, and obstructive jaundice, even endanger life. Therefore, it needs timely treatment once diagnosed. The recurrence of choledocholithiasis after bile duct stones clearance involves complicated factors and cannot be completely elaborated by a single factor. The risk factors for recurrence of choledocholithiasis include bacteria, biliary structure, endoscopic and surgical treatment, and inflammation. The modalities for management of choledocholithiasis are endoscopic retrograde cholangiopancreatography (ERCP), laparoscopic or open common bile duct exploration, dissolving solutions, extracorporeal shockwave lithotripsy (ESWL), percutaneous radiological interventions, electrohydraulic lithotripsy (EHL) and laser lithotripsy. We compare the different benefits between surgery and ERCP. And finally, we make a summary of the current strategy for reducing the recurrence of CBDS and future perspectives for CBDS management.

Cost-effectiveness and resource implications of aggressive action on tuberculosis in China, India, and South Africa: a combined analysis of nine models

BACKGROUND

The post-2015 End TB Strategy sets global targets of reducing tuberculosis incidence by 50% and mortality by 75% by 2025. We aimed to assess resource requirements and cost-effectiveness of strategies to achieve these targets in China, India, and South Africa.

METHODS

We examined intervention scenarios developed in consultation with country stakeholders, which scaled up existing interventions to high but feasible coverage by 2025. Nine independent modelling groups collaborated to estimate policy outcomes, and we estimated the cost of each scenario by synthesising service use estimates, empirical cost data, and expert opinion on implementation strategies. We estimated health effects (ie, disability-adjusted life-years averted) and resource implications for 2016-35, including patient-incurred costs. To assess resource requirements and cost-effectiveness, we compared scenarios with a base case representing continued current practice.

FINDINGS

Incremental tuberculosis service costs differed by scenario and country, and in some cases they more than doubled existing funding needs. In general, expansion of tuberculosis services substantially reduced patient-incurred costs and, in India and China, produced net cost savings for most interventions under a societal perspective. In all three countries, expansion of access to care produced substantial health gains. Compared with current practice and conventional cost-effectiveness thresholds, most intervention approaches seemed highly cost-effective.

INTERPRETATION

Expansion of tuberculosis services seems cost-effective for high-burden countries and could generate substantial health and economic benefits for patients, although substantial new funding would be required. Further work to determine the optimal intervention mix for each country is necessary.

FUNDING

Bill & Melinda Gates Foundation.

Robust reverse logistics network design for the waste of electrical and electronic equipment (WEEE) under recovery uncertainty

The recovery of waste electrical and electronic equipment (WEEE) has become a major issue for solid waste management. Exploring new ways to dispose of WEEE has become mandatory in most of the countries in the world. Reverse logistics which is the backward flows of used product from consumers to producers is an important stage dealing with the WEEE. The reverse logistics network design for WEEE plays an important role in the total cost of recovery system. With this study, taking into account the uncertainty of reverse logistics network operation for WEEE, a robust mixed integer linear programming model for WEEE reverse logistics network was established for handling problem, which was affected by the uncertainty of recovery based on the risk preference coefficient and penalty coefficient deviated from the constraints, that could allow decision-makers to adjust the robust level of the operation system and risk preferences. The calculation and simulation of the model is used for lingo 11.0. The result showed that the robust mixed integer linear programming model was better than the classic model, which had a lower operational risk and could give consideration to the cycles of different circumstances that is effective in inhibiting the uncertainty ofreverse logistics system for WEEE.

Sex differences may affect the severity of poisoning and prognosis after carbon monoxide poisoning: a retrospective study

The objective of this retrospective study was to analyze the relationship between sex and prognosis after carbon monoxide (CO) poisoning. Sixty-six couples diagnosed with CO poisoning were divided into two groups according to premenopausal or postmenopausal females. The prognosis was compared between husbands and wives. A multiple-factor analysis was conducted to determine the effects of sex and age on prognosis. The wives had higher Glasgow Outcome Scale (GOS) scores (P = 0.012) and cure and improvement rate (P = 0.013) than did their husbands within the same poisoning environment. In the premenopausal group, the wives had higher GOS scores (P = 0.023) and cure and improvement rate (P = 0.035) than did their husbands, which was not present in the postmenopausal group. Females had milder classifications in 24 hours (odds ratio [OR] = 2.968; P = 0.010). Females (OR = 0.485; P = 0.034) or patients younger than 40 years old (OR = 5.760; P < 0.001) had higher GOS scores. As the patients diagnosed with mild or moderate poisoning were excluded, age was still related to the GOS scores (OR = 5.714; P = 0.001), but not sex. Females have an advantage over their male spouses in terms of the severity of poisoning and prognosis after CO poisoning, particularly in premenopausal couples. Sex is an important prognostic indicator in CO poisoning.

Cost-effectiveness of a comprehensive programme for drug-resistant tuberculosis in China

Objective

To investigate the cost–effectiveness of a comprehensive programme for drug-resistant tuberculosis launched in four sites in China in 2011.

Methods

In 2011–2012, we reviewed the records of 172 patients with drug-resistant tuberculosis who enrolled in the comprehensive programme and we collected relevant administrative data from hospitals and China’s public health agency. For comparison, we examined a cohort of 81 patients who were treated for drug-resistant tuberculosis in 2006−2009. We performed a cost–effectiveness analysis, from a societal perspective, that included probabilistic uncertainty. We measured early treatment outcomes based on three-month culture results and modelled longer-term outcomes to facilitate estimation of the comprehensive programme’s cost per disability-adjusted life-year (DALY) averted.

Findings

The comprehensive programme cost 8837 United States dollars (US$) per patient treated. Low enrolment rates meant that some fixed costs were higher, per patient, than expected. Although the comprehensive programme appeared 30 times more costly than the previous one, it resulted in greater health benefits. The comprehensive programme, which cost US$ 639 (95% credible interval: 112 to 1322) per DALY averted, satisfied the World Health Organization’s criterion for a very cost–effective intervention.

Conclusion

The comprehensive programme, which included rapid screening, standardized care and financial protection, improved individual outcomes for MDR tuberculosis in a cost-effective manner. To support post-2015 global heath targets, the comprehensive programme should be expanded to non-residents and other areas of China.

Chemotherapy reduces PARP1 in cancers of the ovary: implications for future clinical trials involving PARP inhibitors

BACKGROUND

PARP inhibitors have shown promising clinical results in cancer patients carrying BRCA1/2 mutations. Their clinical efficacy could logically be influenced by PARP1 protein levels in patient tumors.

METHODS

We screened three cohorts of patients with ovarian cancer, totaling 313 samples, and evaluated PARP1 protein expression by immunohistochemistry with further validation by western blotting.

RESULTS

We observed that up to 60 % of tumors showed little PARP1 protein expression. In serous ovarian tumors, comparing intratumoral PARP1 expression between chemo-naïve and post-chemotherapy patients revealed a decrease in intratumoral PARP1 following chemotherapy in all three cohorts (immunohistochemistry: p < 0.001, n = 239; western blot: p = 0.012, n = 74). The findings were further confirmed in a selection of matched samples from the same patients before and after chemotherapy.

CONCLUSION

Our data suggest that patients should be screened for PARP1 expression prior to therapy with PARP inhibitors. Further, the observed reduction of intratumoral PARP1 post-chemotherapy suggests that treating chemo-naïve patients with PARP inhibitors prior to the administration of chemotherapy, or concurrently, might increase the responsiveness to PARP1 inhibition. Thus, a change in the timing of PARP inhibitor administration may be warranted for future clinical trials.

Predictors of survival in children with methymalonic acidemia with homocystinuria in Beijing, China: a prospective cohort study

OBJECTIVE

(i) To determine whether clinical features and biochemical parameters help to predict survival of methylmalonic acidemia with homocystinuria; (ii) To find the cutoff values of biochemical parameters for predicting survival of methylmalonic acidemia with homocystinuria.

DESIGN

A prospective cohort study.

SETTING

A pediatric tertiary hospital in Beijing; all patients were followed until death or June 2013.

SUBJECTS

45 pediatric patients diagnosed with methylmalonic acidemia with homocystinuria between 2006 and 2012.

OUTCOME MEASURES

The data of clinical characteristics and pretreatment biochemical parameters were collected. The Cox regression analysis was performed to identify independent risk factors for survival of patients with methylmalonic acidemia and homocystinuria. The best cutoff values for these independent factors were determined by the receiver characteristic curve.

RESULTS

Newborn onset (OR=6.856, 95%CI=2.241-20.976, P=0.001), high level of methylmalonic acid in urine (OR=1.022, 95%CI=1.011-1.033, P<0.001), and high level of urea in serum (OR=1.083, 95%CI=1.027-1.141, P=0.003) were independent negative risk factors for survival of patients with methylmalonic acidemia and homocystinuria. The cutoff values of maximum predictive accuracy of methylmalonic acid in urine and urea in serum were respectively 5.41 mmol/mmol creatinine and 7.80 mmol/L by receiver operating characteristic curve analysis.

CONCLUSIONS

The patients of methylmalonic acidemia with homocystinuria tend to have an adverse outcome if they have newborn onsets. Elevated urea and urinary methylmalonic acid are predictors of adverse outcomes for the patients. They show similar effect for predicting severe adverse prognosis. The combination of methylmalonic acid in urine concentration and urea in serum concentration provided the most accurate predictive tool.

Patterns of genetic diversity reveal multiple introductions and recurrent founder effects during range expansion in invasive populations of Geranium carolinianum (Geraniaceae)

Genetic diversity, and thus the adaptive potential of invasive populations, is largely based on three factors: patterns of genetic diversity in the species' native range, the number and location of introductions and the number of founding individuals per introduction. Specifically, reductions in genetic diversity ('founder effects') should be stronger for species with low within-population diversity in their native range and few introductions of few individuals to the invasive range. We test these predictions with Geranium carolinianum, a winter annual herb native to North America and invasive in China. We measure the extent of founder effects using allozymes and microsatellites, and ask whether this is consistent with its colonization history and patterns of diversity in the native range. In the native range, genetic diversity is higher and structure is lower than expected based on life history traits. In China, our results provide evidence for multiple introductions near Nanjing, Jiangsu province, with subsequent range expansion to the west and south. Patterns of genetic diversity across China reveal weak founder effects that are driven largely by low-diversity populations at the expansion front, away from the introduction location. This suggests that reduced diversity in China has resulted from successive founder events during range expansion, and that the loss of genetic diversity in the Nanjing area was mitigated by multiple introductions from diverse source populations. This has implications for the future of G. carolinianum in China, as continued gene flow among populations should eventually increase genetic diversity within the more recently founded populations.

Isolation and characterization of microsatellite DNA loci for wild Brassica juncea (Brassicaceae)

Wild Brassica juncea is a widespread weed in China with increasingly great impact on the yield of many crops. This study aimed to develop microsatellite markers for assessing the genetic diversity and population genetic structure of B. juncea, and to provide basic information for biological and chemical control of the weed. The compound microsatellite marker technique was used to develop markers for investigating population genetics of wild B. juncea. Twelve loci were obtained, each of which showed high polymorphisms when tested in two populations in Sichuan and Jiangsu Provinces. The number of alleles per locus ranged from 4 to 27, with an average of 15.2 alleles per locus. The newly developed microsatellite loci will be informative for further investigations of the population genetics and evolutionary patterns of wild B. juncea.

Advances in plastic and cosmetic surgery at home and abroad - a bibliometric analysis

BACKGROUND

Plastic and cosmetic surgery is a new branch deriving from plastic surgery. Although several studies concerning advances in plastic and cosmetic surgeries have been reported, most literatures focus on specific diagnosis and treatment technology, but not the overall progress.

AIM

We attempt to use bibiometric analysis to investigate main research hotspots at home and abroad, outstanding researchers and excellent institutions.

MATERIALS AND METHODS

We retrieved relevant literatures published between 2007 and 2011 in five foreign and four Chinese journals. gCLUTO was used to perform double clustering analysis. Price's Law was used to analyze authors with high yield. Literature profiling was performed to construct author-keyword and institution-keyword matrix to comprehend research feature of high yield authors and research institutions.

RESULTS

A total of 67 and 94 high-frequency words were obtained from English and Chinese journals. Clustering analysis indicated that research hotspots at home and abroad mainly included side-effects of augmentation mammoplasty and its therapy, eyelid plastic surgery, cartilage transplantation and/or cartilage suture in nose plastic surgery, plastic surgery in cheilopalatognathus and nasal deformity, construction of surgical flaps, and facial plastic cosmetology. In addition, several authors and institutions with high yield also had been identified and they might have different research features.

CONCLUSIONS

We investigate advances, hotspots, experts and their institutions in plastic and cosmetic surgery in recent five years at home and abroad, which would provide some research directions for professionals of plastic and cosmetic surgery.

Impact of lesion size on the detection rate of non-palpable breast malignant lesions

OBJECTIVE

To evaluate the impact of lesion size on the detection rate of non-palpable breast malignant lesions and determine whether lesion size should prompt biopsy of non-palpable breast lesions.

METHODS

The study included 816 ultrasonographically detected non-palpable breast lesions. We divided the lesions into five groups based on their largest diameters: ≤0.5cm, 0.6-1.0cm, 1.1-1.5cm, 1.6-2.0 cm, and >2.0 cm. The detection rate of malignancies of different sizes were compared among these lesions, Breast Imaging Reporting and Data System (BI-RADS) category 2-3 lesions, and BI-RADS grades 4-5 lesions. The feasibility of using lesion size as biopsy indicator for BI-RADS category 2-3 non-palpable breast lesion was analyzed using ROC curve.

RESULTS

Of these 816 lesions, 100 (12.3%) were found to be malignant lesions. The detection rate of malignancy significantly increased along with the increase of lesion size (P<0.05). When the BI-RADS category was not considered, the frequency of malignancy in the >2.0 cm group was significantly higher than in other groups (P<0.05) The frequencies of malignancy in the 0.6-1.0 cm group, 1.1-1.5 cm group, and 1.6-2.0 cm group were higher than that in ≤0.5 cm group, but the difference was not significant (P>0.05) For BI RADS category 4 and 5 lesions, the frequency of malignancy in >2.0 cm group was higher than in other groups, but significant difference was only seen between >2.0 cm group and ≤0.5 cm group (P<0.05).

CONCLUSIONS

Lesion size may influence the detection rate of malignancy of non palpable breast lesions, and can be used as biopsy indicator of non palpable breast lesions in BI-RADS 2,3 category When we use 1.25cm as threshold,the sensitivity and specificity may be satisfying.

Role of fine needle aspiration cytology in surgical treatment of breast cancer

OBJECTIVE

To evaluate the clinical value of fine needle aspiration cytology (FNAC) for breast cancer surgery.

METHODS

FNAC was performed in 530 patients highly suspected of breast cancer from January 2004 to January 2009 in Peking Union Medical College Hospital. The FNAC-positive cases received radical operation directly, while the negative cases received open biopsy.

RESULTS

Of all 530 cases, 325 cases were FNAC-positive, and the diseases were histopathologically confirmed to be malignant. Among 205 FNAC-negative cases, 137 cases were histopathologically confirmed to be malignant and 68 benign.

CONCLUSION

FNAC is useful in the deciding surgical modes for women with potentially malignant diseases.

First Report of Southern Blight on Canadian Goldenrod (Solidago canadensis) Caused by Sclerotium rolfsii in China

Canadian goldenrod (Solidago canadensis L., Asteraceae) is a rhizomatous perennial plant native to North America that has invaded eastern China and continues to spread northward and westward. It is quite common on field borders, roadsides, and in undeveloped areas, posing a serious threat to native ecosystems and their biodiversity. During the late summers of 2007 and 2008, wilted Canadian goldenrod plants were occasionally found in invasive populations in the suburb of Nanjing city. Wilted plants were transplanted and maintained in a greenhouse at Nanjing Agricultural University. A white mass of fungal hyphae, which grew on the soil surface around the stem of the symptomatic S. canadesis plants and eventually covered the stem, was observed. Initially, the base of the stem became yellow, turned brown, and the light brown discoloration extended up the stem to a height of 3 to 7 cm. The leaves then collapsed, starting from the top until the entire plant wilted. The fungus produced numerous, small, roundish sclerotia of uniform size (0.7 to 2.0 mm in diameter), which were white at first and then became brown to dark brown. The fungus grew into the stems and downward into the rhizome area, but no sclerotia were detected inside the stem or root. Diseased tissue with sclerotia was disinfested for 1 min in 1% NaOCl and plated on potato dextrose agar amended with 100 mg/liter of streptomycin sulfate. On the basis of sclerotia morphology and the presence of clamp connections at hyphal septa, the fungus was identified as Sclerotium rolfsii. Pathogenicity of the isolate was confirmed by inoculating 1-year-old S. canadensis plants (average 1.5 m high) grown in pots. The inoculum consisted of cottonseed hulls infested with mycelium and sclerotia of the pathogen and was placed on the soil surface around the base of each unwounded plant. Noninoculated plants served as controls. The pathogenicity test was conducted twice. After inoculation, the plants were maintained at high humidity and 30°C for 3 days and then transferred to a greenhouse. All inoculated plants developed symptoms of southern blight. Inoculated plants developed symptoms of wilting 5 to 7 days after inoculation and were completely wilted within 15 to 20 days. Symptoms of wilting were soon followed by the appearance of white-to-light brown sclerotia on the collar region. Control plants remained symptomless and Sclerotium rolfsii was reisolated from inoculated plants. To our knowledge, this is the first report of southern blight of Canadian goldenrod caused by Sclerotium rolfsii in China.

Hydrogen therapy reduces apoptosis in neonatal hypoxia-ischemia rat model

Hypoxia-ischemia (HI) brain injury is a major cause of neuronal cell death especially apoptosis in the perinatal period. This study was designated to examine the effect of hydrogen therapy on apoptosis in an established neonatal HI rat pup model. Seven-day-old rat pups were subjected to left common carotid artery ligation and then 90 min hypoxia (8% oxygen at 37 degrees C). Immediately after HI insult, pups were placed into a chamber filled with 2% H2 for 30 min, 60 min, or 120 min, respectively. 24 h after 2% H2 therapy, the pups were decapitated and brain injury was assessed by 2,3,5-triphenyltetrazoliumchloride (TTC), Nissl, and TUNEL staining, as well as caspase-3, caspase-12 activities in the cortex and hippocampus. H2 treatment in a duration-dependent manner significantly reduced the number of positive TUNEL cells and suppressed caspase-3 and -12 activities. These results indicated H2 administration after HI appeared to provide brain protection via inhibition of neuronal apoptosis.

Raman spectroscopic studies of the phase transitions in hexane at high pressure

Raman spectroscopic study of n-hexane was carried out in a cubic zirconia anvil cell up to approximately 2.0 GPa. Under high pressure, the C-H stretching region of the spectrum at 2850-3000 cm(-1) shows measurable changes in frequency, bandwidth, and intensity. These Raman bands shift towards higher frequencies with increasing pressure. At about 1.4 GPa, phase transition from liquid to solid was induced by compression, as was simultaneously observed with the built-in microscope.

Efficacy of nonwoven fabric bioreactor immobilized with porcine hepatocytes for ex vivo xenogeneic perfusion treatment of liver failure in dogs

We have developed a new bioartificial liver bioreactor filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF). In this study, we investigated the efficacy of our hybrid bioartificial liver system incorporating the NWF bioreactors and an immunoglobulin adsorbent column for perfusion treatment in a canine liver failure model. Xenogeneic perfusion treatment for operative canine liver failure models were performed for 3 h, and survival time, intracranial pressure, and blood and cerebrospinal fluid data were documented. Treatment was carried out without obstruction by immunological rejection when immunoglobulin adsorbent columns were used with the NWF bioreactors in combination. Dogs treated with this system exhibited a restricted increase of intracranial pressure and significant compensatory effects on blood and cerebrospinal amino acid imbalances as shown by a significant improvement of Fischer's ratio. On the other hand, relatively low capacity for ammonia elimination was shown as compared with homologous direct hemoperfusion.

Variation between ASP-1 molecules from Ancylostoma caninum in China and the United States

Hookworm infection continues to be a serious problem in rural areas of China. Rapid reinfection and high cost limit the effectiveness of deworming programs. Vaccination offers an attractive alternative to mass chemotherapy. However, variation in vaccine antigens from field hookworm populations could conceivably limit efficacy of a vaccine developed from laboratory strains. Reported here are initial experiments to ascertain levels of molecular variation in a promising vaccine antigen, ASP-1, from the dog hookworm Ancylostoma caninum. ASP-1 from a Chinese strain of A. caninum was isolated from a third-stage larval cDNA library and compared to ASP-1 from a U.S. strain. There was 97% and 98% similarity in the DNA and amino acid sequences, respectively. There were 42 polymorphic sites between the sequences, 30 of which were synonymous. The 12 nonsynonymous substitutions resulted in 10 changes in the deduced amino acid sequence. Five of the amino acid changes were in the N-terminal domain, whereas the C-terminal domain was more highly conserved, containing only 2 amino acid changes. The results suggest that the effect of molecular variation in antigens from geographically separated parasite populations should be considered during vaccine development.

Hookworm burden reductions in BALB/c mice vaccinated with recombinant Ancylostoma secreted proteins (ASPs) from Ancylostoma duodenale, Ancylostoma caninum and Necator americanus

Vaccination of mice with alum-precipitated recombinant Ancylostoma secreted protein-1 from the canine hookworm Ancylostoma caninum (Ac-ASP-1) results in protection against A. caninum larval challenge. Vaccine protection is manifested by host reductions in hookworm burden compared to control mice. The goal of this study was to determine whether ASP antigens cloned and expressed from different hookworm species will cross protect against A. caninum larval challenge. Cross-species protection against A. caninum challenge infections was observed with immunizations using recombinant ASP-1 from the human hookworms Ancylostoma duodenale and Necator americanus. However, the degree of protection was proportional to the extent of amino acid sequence homology between the ASP immunogen used for vaccination and the Ac-ASP-1 produced by the challenge larval strain. Vaccine protection was noted to decrease significantly as amino acid sequence homologies diverged 10% or more. It was also determined that Ac-ASP-2, a molecule cloned from A. caninum having 55% amino acid sequence homology to the C-terminus of Ac-ASP-1, did not elicit vaccine protection. These observations were partly reflected in the titer of antibodies that recognize Ac-ASP-1. The studies reported here will help to design immunogenic peptide vaccines based on the sequence divergence of hookworm ASPs.

Comparative evaluation of different membranes for the construction of an artificial liver support system

During the past decades, many technological improvements have been made in the construction of extracorporeal liver support systems. Among these achievements, membranes of artificial capillary system, used as substrates of hepatocyte growth, aroused our interest in their application for the construction of bioreactors. The present paper studied the comparison of hepatocyte growth and function on six different membranes. Four of them are cellulose based membranes, Cuprophan, Hemophan, Cellulose acetate, and Bioflux; two are synthetic polymer SPAN and Polysulphone. Human hepatoma cell line SMMC-7721, with moderately differentiated hepatocyte-specific functions, was inoculated into the hollow fiber cartridges. These cells were allowed to attach and to grow over these membranes. It was found that there existed differences in hepatocyte immobilization and growth among these membranes. They influenced the growth and functions of hepatoma cells in vitro to some extent. These results show that membrane is an important factor in the construction of capillary membrane bioreactors for artificial liver support.