Seroprevalence of Toxocara canis infection among children in Swaziland, southern Africa.

As there appeared to be no data available on Toxocara canis infection in the children of Swaziland, a serological survey of T. canis infection was recently conducted among 92 children aged 3-12 years from rural slums in the low- and middle-veld. A child was considered seropositive if, in western blots based on the excretory-secretory antigens of larval T. canis, his or her serum gave a positive result when diluted 1 : 64. Forty-one (44.6%) of the children were found seropositive. There were no statistically significant differences in seroprevalence between the 49 boys and 43 girls investigated (46.9% v. 41.8%) or between the eight subjects aged 12 years and the 47 aged < or = 5 years (62.5% v. 38.3%); the corresponding odds ratios were 0.81 (95% confidence interval=0.36-1.86; P=0.62) and 2.69 (95% confidence interval=0.57-12.62; P=0.20), respectively. The 66 subjects from the middleveld were, however, significantly more likely to be seropositive than the 26 subjects from the lowveld (54.5% v. 19.2%; odds ratio=5.04, with a 95% confidence interval of 1.70-14.98; P<0.01). It seems likely that T. canis infection is common among the children who live in slums in Swaziland, particularly in the country's middleveld, probably as the result of poor hygiene and poor sanitation.

Optimizing production of polyunsaturated fatty acids in Marchantia polymorpha cell suspension culture.

Chlorophyll containing callus cells of Marchantia polymorpha are able to grow under dim illumination in the presence of an organic carbon source and retain the ability to produce polyunsaturated fatty acids (PUFA), including C(20) fatty acids. Highest PUFA production was achieved using 2,4-dichlorophenoxyacetic acid as growth regulator. Inoculum size, illumination intensity, organic carbon source, and ferrous ion are the major factors affecting PUFA productivity. Maximum PUFA productivity is attained under low light intensity, with a photon flux density ca. 20 micromol m(-2) s(-1). Optimal inoculum size and glucose concentration for PUFA production are 8-12% and 20-30 g l(-1), respectively. Ferrous ion can promote PUFA productivity by increasing the intracellular lipid content. Highest productivities for PUFA, arachidonic acid (ARA), and eicosapentaenoic acid (EPA) were 35.0+/-2.1, 6.7+/-0.4 and 6.6+/-0.4 mg l(-1) day(-1), respectively. PUFA production in the M. polymorpha culture is shown to be strongly growth-associated. Environmental stress (osmotic pressure) is ineffective in promoting PUFA productivity. Chitosan, an elicitor, also has no effect on intracellular PUFA content in cultured M. polymorpha cells.

Green fluorescent protein as a secretory reporter and a tool for process optimization in transgenic plant cell cultures.

Green fluorescent protein (GFP) is an attractive reporter for bioprocess monitoring. Although expression of GFP in plants has been widely reported, research on the use of GFP in plant cell cultures for bioprocess applications has been limited. In this study, the suitability of GFP as a secretory reporter and a useful tool in plant cell bioprocess optimization was demonstrated. GFP was produced and secreted from suspension cells derived from tobacco that was transformed with a binary vector containing mgfp5-ER cDNA, a modified GFP for efficient sorting to the endoplasmic reticulum, under control of the CaMV 35S promoter. For cell line gfp-13, extracellular and intracellular GFP accumulated to 15.4 and 29.4 mg x 1(-1), respectively. Extracellular GFP accounted for 30.9% of the total extracellular protein. The molecular mass of extracellular GFP was nearly identical to that of a recombinant GFP standard, indicating cleavage of the signal sequence. Neomycin phosphotransferase II, a cytosolic selection marker, was found almost exclusively in cellular extracts with less than 2% in the extracellular medium. These results suggest that extracellular GFP is most likely the result of secretion rather than nonspecific leakage from cells. Furthermore, medium fluorescence intensity correlated nicely with extracellular GFP concentration supporting the use of GFP as a quantitative secretory reporter. During the batch cultivation, culture GFP fluorescence also followed closely with cell growth. A medium feeding strategy was then developed based on culture GFP fluorescence that resulted in improved biomass as well as GFP production in a fed-batch culture.

Optimal design of the tubular microporous membrane aerator for shear-sensitive cell cultures.

In this paper, a theoretical analysis of oxygen transport across the tubular microporous membrane is described. This analysis has provided some insight into the optimal design of the membrane aerator. It was found in this study, at fixed inlet pressure, that the overall membrane oxygen transfer rate increases with increased tubing length only up to a certain length, i.e., the "critical length". When a large membrane surface area is required, the fiber should be divided into parallel segments to increase the overall oxygen transfer rate. A manifold or a gas distributor can then be used to distribute gas into segments of tubing. The length of each segment cannot exceed the critical length. In addition, shorter tube segments should give a higher oxygen transfer rate per unit tube length; however, this advantage is counterbalanced by the fact that gas distribution into huge numbers of parallel tubings may not be uniform.

[Clinical research on the relation of chronic gastritis and intragastric bile acids].

Intragastric bile acids on fasting for 1 hour have been determined by radioimmunoassay and thin-layer chromatographic scanning in 102 cases of chronic gastritis. The results showed that all of intragastric conjunction bile acids were higher in chronic atrophic gastritis group than those in chronic superficial gastritis group. Both of their intragastric bile acids and nitrite levels increased significantly in patients whose gastric mucosa appeared acute inflammation, glandular atrophy and moderate or severe intestinal metaplasia. These findings suggest that bile acids may be implicated in premalignant histological changes of gastric mucosa such as chronic atrophic gastritis. Determining intragastric bile acids will reflect the degree and injurious effect of duodenogastric reflux.

[In vitro anti-microbial activity against H. pylori and clinical efficacy of various drugs].

The in vitro antimicrobial activity against H. pylori and clinical efficacy of various antibiotics and antiulcer drugs are summarized in this study. H. pylori highly sensitive to most of the beta-lactams and macrolides. Especially, amoxicillin and clarithromycin have satisfactory in vitro activity against H. pylori. The anti-ulcer drugs, sofalcon and plaunotol, used in Japan as mucosal protective agents, also have a weak activity against H. pylori with MIC50 12.5 micrograms/ml and MIC90, 50-100 micrograms/ml, while H2-receptor antagonists do not have in vitro activity. Efficacy of antibiotics as monotherapy for eradicating H. pylori is rather poor. The best results with monotherapy are obtained with clarithromycin and amoxicillin. Omeprazole monotherapy suppresses H. pylori infection but does not eradicate H. pylori. Combined therapy with omeprazole and amoxicillin have strong synergistic effects on the eradication of H. pylori (68.8%). Newly developed proton pump inhibitors, such as lansoprazole, E-3810 and their derivatives, showed strong in vitro activity against H. pylori suggesting that these drugs may be useful for the treatment of H. pylori infection.

Increased expression of PRL-1 protein correlates with shortened patient survival in human hepatocellular carcinoma.

BACKGROUND: The purposes of the current study were to investigate whether overexpression of the PRL-1 is clinically relevant to hepatocellular carcinoma (HCC) and whether expression patterns of PRL-1 in HCC have diagnostic and prognostic value. METHODS: Immunohistochemistry analysis was performed for PRL-1 in 60 HCC samples. The data were correlated with clinicopathological features. The univariate and multivariate survival analyses were also performed to determine their prognostic significance. RESULTS: PRL-1 protein was overexpressed (83%) in HCC as compared with the adjacent normal tissue. PRL-1 expression was not influenced by chronic alcohol exposure or cirrhosis. High expression of PRL-1 was correlated with smoking (p=0.012), cirrhosis (p=0.047) and histological grade (p=0.055). The Kaplan-Meier survival curves showed that high PRL-1 expression related to a poor survival with statistical significance (I vs. III, p=0.010; II vs. III, p=0.001). Univariate analysis showed that PRL-1 expression was associated with tumour size, stage and PRL-1 score. Multivariate analysis revealed that the PRL-1 protein expression level was an independent factor for overall survival (HR, 5.367; 95% CI, 2.270-12.692; p=0.001). This is the first demonstration that the expression level of PRL-1 is correlated with tumour progression and prognosis in HCC. CONCLUSIONS: Along with other results, the PRL-1 protein is a candidate biomarker and a potential target for novel therapies against human HCC progression.

Clinical characteristics of optic neuritis in Taiwanese children.

PURPOSE: To document the etiology, clinical presentation, and visual prognosis of optic neuritis in Taiwanese children. METHODS: Retrospectively reviewed children younger than 18 years old with optic neuritis in Chang Gung Memorial Hospital and Chang Gung Children's Hospital from 1998 to 2009. RESULTS: There were 24 children (38 eyes) with optic neuritis in that period. Overall, 14 patients (58.3%) were female and 10 patients (41.7%) were male. In total, 14 patients (58.3%) had bilateral involvement, and 10 patients (41.7%) had unilateral involvement. Out of 38 eyes, 24 (63.2%) had disc swelling. Out of 24 patients, 21 (87.5%) underwent intravenous steroid therapy (10 to 30 mg/kg/day) for 3-5 days, and followed by an oral taper. Out of 24 patients, 20 (83.3%) achieved final visual acuity (VA) of 20/40 or better. However, a poor visual outcome (four patients) (VA<20/40) was correlated with pale disc at presentation (P=0.002, Pearson χ (2)-test) and age older than 10 years (P=0.012, Fisher's exact test). Five patients were diagnosed with acute disseminated encephalomyelitis (ADEM) (21%), and three patients were diagnosed with multiple sclerosis (MS) (12.5%). Patients with ADEM did not have a better visual outcome than patients with MS (P=0.643, Fisher's exact test). CONCLUSIONS: Visual recovery from optic neuritis was favorable in Taiwanese children. A poor visual outcome was correlated with pale disc at presentation and patients' age older than 10 years. ADEM is the most common associated systemic disease; MS is relatively rare.

A community-based RCT for oral cancer screening with toluidine blue.

Early detection of oral premalignant lesions (OPMLs) by visual inspection with toluidine blue has not been addressed. We conducted a community-based randomized controlled trial to assess whether using toluidine blue as an adjunctive tool for visual screening had a higher detection rate of OPMLs and could further reduce the incidence of oral cancer. In 2000, in Keelung, we randomly assigned a total of 7975 individuals, aged 15 years or older and with high-risk oral habits, to either the toluidine-blue-screened (TBS) group or the visual screening group. Results showed 5% more oral premalignant lesions and 79% more oral submucous fibrosis detected in the TBS group than in the control group. After a five-year follow-up ascertaining oral cancer development through linkage to the National Cancer Registry, the incidence rate in the TBS group (28.0 x 10(-5)) was non-significantly 21% lower than that in the control group (35.4 x 10(-5)).

Perfusion strategy for rosmarinic acid production by Anchusa officinalis.

The production of an intracellular secondary metabolite rosmarinic acid (RA) by plant cell suspensions of Anchusa officinalis cultivated with intermittent medium exchange is investigated. Initially, a two-stage perfusion culture method was employed. After being cultured in the batch mode for ca. 6 days in B5 medium plus 3% sucrose, 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), and 0.1 mg/L kinetin (2,4-D B5 medium), Anchusa culture was cultivated to high cell density by perfusion during the growth stage using a hormone-free Gamborg B5 medium supplemented with 6% sucrose. This was followed by a production stage, in which a complete medium exchange into B5 medium plus 3% sucrose and 0.25 mg/L naphthleneacetic acid (NAA) was conducted. The two-stage perfusion culture had a higher maximum culture RA concentration but a lower RA content per cell than the batch stock culture maintained in the 2,4-D B5 medium. Higher culture RA concentration was due primarily to high cell density. The high packed cell volume, however, seemed to reduce the synergistic effect of NAA on RA synthesis. Subsequently, a single-stage perfusion culture method was investigated. The best result was obtained by growing the culture in the batch mode for ca. 10 days using B5 medium supplemented with 3% sucrose and 0.25 mg/L NAA, followed by perfusing the culture with B5 medium plus 6% sucrose and 0.25 mg/L NAA at a constant perfusion rate of 0.1/day. A maximum cell dry weight of 35 g/L and a RA concentration of almost 4 g/L were achieved. This is the highest RA concentration ever reported in the Anchusa culture.

Dysarthria associated with giant cell arteritis.

Over a one month period, a 74-year-old man developed typical features of giant cell arteritis (GCA) including visual changes, headache, scalp tenderness, and an elevated erythrocyte sedimentation rate. In addition, he had reproducible painless dysarthria that was precipitated by chewing or prolonged talking and was relieved by resting the jaw. The dysarthria with chewing along with the other classical symptoms of GCA subsided with treatment. To our knowledge this is the first report of painless dysarthria associated with GCA.

Growth and gas production for hyperthermophilic archaebacterium, Pyrococcus furiosus.

Pyrococcus furiosus represents one of the most important hyperthermophilic bacteria isolated thus far because of its relatively high cell yields and rapid growth rates. Pyrococcus furiosus exhibits several interesting growth characteristics, especially in terms of biotic gas production, which were examined in this study. In the presence of elemental sulfur, both carbon dioxide and hydrogen sulfide production appeared to be strongly growth associated, while no significant hydrogen production was observed. In the absence of sulfur, hydrogen and carbon dioxide were produced by the organism and hydrogen inhibition was observed. The addition of elemental sulfur to the medium apparently eliminated, hydrogen inhibition as growth proceeded normally even when hydrogen was added to the gas phase. Also, no apparent substrate limitation or toxic product could be attributed to the cessation of growth as cell growth in spent media was at least as good as in fresh media. An unstructured growth model was used to correlate growth and gas production for P. furiosus in complex seawater-based media at 98 degrees C both in the absence and presence of elemental sulfur. The model was shown to be useful for examining some of the observations made in this study.

Helicobacter pylori with separate beta- and beta'-subunits of RNA polymerase is viable and can colonize conventional mice.

The genes encoding the beta- and beta'-subunits of RNA polymerase (rpoB and rpoC respectively) are fused as one continuous open reading frame in Helicobacter pylori and in other members of this genus, but are separate in other bacterial taxonomic groups, including the closely related genus Campylobacter. To test whether this beta-beta' tethering is essential, we used polymerase chain reaction-based cloning to separate the rpoB and rpoC moieties of the H. pylori rpoB-rpoC fusion gene with a non-polar chloramphenicol resistance cassette containing a new translational start, and introduced this construct into H. pylori by electro-transformation. H. pylori containing these separated rpoB and rpoC genes in place of the native fusion gene produced non-tethered beta and beta' RNAP subunits, grew well in culture and colonized and proliferated well in conventional C57BL/6 mice. Thus, the extraordinary beta-beta' tethering is not essential for H. pylori viability and gastric colonization.

Prevalence of vacuolating cytotoxin production and distribution of distinct vacA alleles in Helicobacter pylori from China.

Studies of Helicobacter pylori from the West have linked production of vacuolating cytotoxin and a particular signal sequence (s1a) allele of the underlying vacA gene to peptic ulcer disease (PUD). Among Chinese H. pylori, most isolates from both PUD and gastritis patients were toxigenic (35/46 and 29/35, respectively). Polymerase chain reaction and DNA sequencing showed that 95 of 96 isolates carried vacA s1a alleles. In the mid-region, 78 of 96 isolates carried m2; 14 were m1-like but only 87% identical (DNA-level) to classical m1 and were designated m1b; the other 4 were unusual hybrids (m1b-type proximal, m2-type distal). Isolates with m1b and m1b-m2 alleles produced higher levels of vacuolating activity than did isolates with m2 alleles (P < .01). There was no association between any vacA allele and disease. These results suggest that the composition of H. pylori gene pools varies geographically and that other as-yet-unknown polymorphic H. pylori genes are important in PUD.