MSC-Based Cell Therapy in Neurological Diseases: A Concise Review of the Literature in Pre-Clinical and Clinical Research

Mesenchymal stem cells (MSCs) are multipotent stromal cells with the ability to self-renew and multi-directional differentiation potential. Exogenously administered MSCs can migrate to damaged tissue sites and participate in the repair of damaged tissues. A large number of pre-clinical studies and clinical trials have demonstrated that MSCs have the potential to treat the abnormalities of congenital nervous system and neurodegenerative diseases. Therefore, MSCs hold great promise in the treatment of neurological diseases. Here, we summarize and highlight current progress in the understanding of the underlying mechanisms and strategies of MSC application in neurological diseases.

[A transcriptomic analysis of correlation between mitochondrial function and energy metabolism remodeling in mice with myocardial fibrosis following myocardial infarction]

OBJECTIVE

To investigate the changes of mitochondrial respiratory function during myocardial fibrosis in mice with myocardial infarction (MI) and its correlation with the increase of glycolytic flux.

METHODS

Forty C57BL/6N mice were randomized into two equal groups to receive sham operation or ligation of the left anterior descending coronary artery to induce acute MI. At 28 days after the operation, 5 mice from each group were euthanized and left ventricular tissue samples were collected for transcriptomic sequencing. FPKM method was used to calculate gene expression levels to identify the differentially expressed genes (DEGs) in MI mice, which were analyzed using GO and KEGG databases to determine the pathways affecting the disease process. Heat maps were drawn to show the differential expressions of the pathways and the related genes in the enrichment analysis. In primary cultures of neonatal mouse cardiac fibroblasts (CFs), the changes in mitochondrial respiration and glycolysis levels in response to treatment with the pro-fibrotic agonist TGF-β1 were analyzed using Seahorse experiment.

RESULTS

The mouse models of MI showed significantly increased diastolic and systolic left ventricular diameter (P < 0.05) and decreased left ventricular ejection fraction (P < 0.0001). A total of 124 up-regulated and 106 down-regulated DEGs were identified in the myocardial tissues of MI mice, and GO and KEGG enrichment analysis showed that these DEGs were significantly enriched in fatty acid metabolism, organelles and other metabolic pathways and in the mitochondria. Heat maps revealed fatty acid beta oxidation, mitochondrial dysfunction and increased glycolysis levels in MI mice. In the primary culture of CFs, treatment with TGF-β1 significantly reduced the basal and maximum respiratory levels and increased the basal and maximum glycolysis levels (P < 0.0001).

CONCLUSION

During myocardial fibrosis, energy metabolism remodeling occurs in the CFs, manifested by lowered mitochondrial function and increased energy generation through glycolysis.

Differences of Escherichia coli isolated from different organs of the individual sheep: molecular typing, antibiotics resistance, and biofilm formation

Despite numerous studies on Escherichia coli (E. coli) from sheep, there have been few reports on the characterization of E. coli isolates from various organs of individual sheep until now. The present study conducted molecular typing, antibiotics resistance, biofilm formation, and virulence genes on E. coli isolated from 57 freshly slaughtered apparently healthy sheep carcasses, gallbladders, fecal samples, and mesenteric lymph nodes (MLNs). The results demonstrated that the detection rate of R1 LPS core type in E. coli isolated from fecal samples (70.83%) was higher than that from other organs, but the detection rate of antibiotic resistance genes was lower (P < 0.05). The predominant phylogenetic group of E. coli isolated from the carcasses was group B1 (93.33%), and the detection rate of multidrug-resistance phenotype (80%) and the resistance rate of E. coli was higher than that from other organs (P < 0.05). Interestingly, the intensity of biofilm formation of E. coli isolated from MLNs was higher than that from other organs (P < 0.05). However, except for ibeB, the detection rates of virulence genes did not differ in E.coli isolated from different organs. In conclusion, differences were noted in these parameters of E. coli isolated from different organs of individual sheep. Therefore, the data may contain considerable mistakes concerning the actual situation in the host if we only analyze the data of E. coli isolated from feces or carcasses.

Down-regulation of β-lactam antibiotics resistance and biofilm formation by Staphylococcus epidermidis is associated with isookanin

Introduction

Biofilm formation is the major pathogenicity of Staphylococcus epidermidis (S. epidermidis), which enhances bacterial resistance to antibiotics. Isookanin has potential inhibitory activity on biofilm.

Method

The inhibiting mechanisms of isookanin against biofilm formation through surface hydrophobicity assay, exopolysaccharides, eDNA, gene expression analysis, microscopic visualization, and molecular docking were explored. Additionally, the combination of isookanin and β-lactam antibiotics were evaluated by the broth micro-checkerboard assay.

Results

The results showed that isookanin could decrease the biofilm formation of S. epidermidis by ≥85% at 250 μg/mL. The exopolysaccharides, eDNA and surface hydrophobicity were reduced after treatment with isookanin. Microscopic visualization analysis showed that there were fewer bacteria on the surface of the microscopic coverslip and the bacterial cell membrane was damaged after treatment with isookanin. The down-regulation of icaB and up-regulation of icaR were observed after treatment with isookanin. Additionally, the RNAIII gene was significantly up-regulated (p < 0.0001) at the mRNA level. Molecular docking showed that isookanin could bind to biofilm-related proteins. This indicated that isookanin can affect biofilm formation at the initial attachment phase and the aggregation phase. The FICI index showed that the combination of isookanin and β-lactam antibiotics were synergistic and could reduce doses of antibiotics by inhibiting biofilm formation.

Discussion

This study improved the antibiotic susceptibility of S. epidermidis through inhibition of the biofilm formation, and provided a guidance for the treatment of antibiotic resistance caused by biofilm.

3β-Hydroxysteroid dehydrogenase expressed by gut microbes degrades testosterone and is linked to depression in males

Testosterone deficiency can lead to depressive symptoms in humans; however, the causes of this deficiency are incompletely understood. Here, we isolated Mycobacterium neoaurum from the fecal samples of testosterone-deficient patients with depression and showed that this strain could degrade testosterone in vitro. Furthermore, gavaging rats with M. neoaurum reduced their serum and brain testosterone levels and induced depression-like behaviors. We identified the gene encoding 3β-hydroxysteroid dehydrogenase (3β-HSD) as the enzyme causing testosterone degradation. Introducing 3β-HSD into Escherichia coli enhanced its ability to degrade testosterone. Gavaging rats with 3β-HSD-producing E. coli reduced their serum and brain testosterone levels and caused depression-like behaviors. Finally, compared with 16.67% of participants without depression, 42.99% (46/107) of the fecal samples of patients with depression harbored 3β-HSD, and 60.87% (28/46) of these fecal samples expressed 3β-HSD. These results suggest that 3β-HSD expressed by gut microbes may be associated with depressive symptoms due to testosterone degradation.

The dUTPase of caprine arthritis-encephalitis virus negatively regulates interferon signaling pathway

Background

Deoxyuracil triphosphate nucleotide (dUTP) pyrophosphatase (dUTPase, DU) is an enzyme of caprine arthritis-encephalitis virus (CAEV) that minimizes incorporation of dUTP into the DNA. Caprine arthritis-encephalitis virus relies partly on its ability to escape from innate immunity to cause persistent infections. Interferon β (IFN-β) is an important marker for evaluating the innate immune system, and it has a broad spectrum of antiviral activity.

Aims

This study was conducted to investigate the details of the IFN-β response to CAEV infection.

Methods

The expression of IFN-β and the proliferation of Sendai virus (SeV) and vesicular stomatitis virus (VSV) were determined by real-time quantitative polymerase chain reaction (qPCR). The effect of DU on the IFN signaling pathway was evaluated using luciferase reporter assays.

Results

In our study, the expression of IFN-β was significantly inhibited and the proliferation of SeV and VSV was promoted in cells overexpressing CAEV-DU. DU affected interferon stimulated response element (ISRE) and IFN-β promoter activities induced by RIG-I/MDA5/MAVS/TBK1 pathway, while did not affect them induced by interferon regulatory factor 3 (IRF3-5D).

Conclusion

DU protein downregulated the production of IFN-β by inhibiting the activity of the signal transduction molecules upstream of IRF3, thereby, helping CAEV escape innate immunity. Findings of this work provide an evidence to understand the persistent infection and multiple system inflammation of CAEV.

Wake dynamics of air filaments generated by high-energy picosecond laser pulses at 1 kHz repetition rate

We investigated the filamentation in air of 7 ps laser pulses of up to 200 mJ energy from a 1.03 μm-wavelength Yb:YAG laser at repetition rates up to f=1kHz. Interferograms of the wake generated show that while pulses in a train of repetition rate f=0.1kHz encounter a nearly unperturbed environment, at f=1kHz, a channel with an axial air density hole of ∼20% is generated and maintained at all times by the cumulative effect of preceding laser pulses. Measurements at f=1kHz show that the energy deposited decreases proportional to the air channel density depletion, becoming more pronounced as the repetition rate and pulse energy increase. Numerical simulations indicate that contrary to filaments generated by shorter duration pulses, the electron avalanche is the dominant energy loss mechanism during filamentation with 7 ps pulses. The results are of interest for the atmospheric propagation of joule-level picosecond pulses from Yb:YAG lasers, of which average powers now surpass 1 kW, and for channeling other directed energy beams.

[Huangqin decoction alleviates ulcerative colitis by regulating ILC3s-TH cell response]

OBJECTIVE

To explore the effect of Huangqin decoction (HQD) on group 3 innate lymphoid cells (ILC3s) and helper T cells (Th) for treatment of ulcerative colitis (UC).

OBJECTIVE

Male Balb/c mice were randomly divided into control group, DSS group, mesalazine group (ME, 400 mg/kg), and 2.275 g/kg, 4.55 g/kg and 9.1 g/kg HQD groups. All the mice were given free access to normal chow. Except for those in the normal control group, all the mice were given 3% DSS solution for 7 days to establish models of UC. The mice in ME group and 3 HQD groups were given mesalazine or HQD via oral gavage at the specified doses once a day. Flow cytometry was performed to analyze the ILC3s, MHC Ⅱ, Th1 and Treg in the lamina propria lymphocytes in the colon. Milliplex was performed to determine cytokine levels of in the colon tissues.

OBJECTIVE

Compared with those in DSS group, the mice in the 3 HQD groups all showed obviously lessened symptoms of UC with significantl decreased DAI score (P < 0.001) and macroscopic score (P < 0.001). The results of flow cytometry showed that HQD treatment significantly increased the percentage of ILC3s (P < 0.05) and expression of MHCⅡ (P < 0.05), obviously reduced the proportion of Th1 (P < 0.05) but increased Treg cells (P < 0.05) in the colon tissues. Milliplex showed that HQD treatment significantly reduced the expressions of Th-related pro-inflammatory cytokines including IL-2 (P < 0.05), IL-17A (P < 0.05), IL-23 (P < 0.05), TNF-α (P < 0.05), and IFN-γ (P < 0.05).

OBJECTIVE

HQD alleviates DSS- induced UC in mice by increasing ILC3s and MHC Ⅱ expression to suppress the function of Th17 and Th1 cells and promote Treg and Th2 cells.

Studies on the effects of LPS, ß-glucan and metabolic inhibitors on the respiratory burst and gene expression in Atlantic salmon macrophages

Reactive oxygen species (ROS) production in macrophage-like cells is induced as an antimicrobial defence against invading pathogens. In this study, we have explored how different stimuli and metabolic inhibitors affect the level of respiratory burst in Atlantic salmon (Salmo salar L.) head kidney macrophage-like cells. Cells stimulated in vitro by bacterial lipopolysaccharide (LPS) and ß-glucan showed increased production of ROS compared to unstimulated cells. Both stimulation and costimulation by curdlan (ß-glucan) induced a higher production of ROS compared to stimulation and costimulation by LPS. Metabolic inhibitors co-incubated with the stimulants did not, in most cases, perturb the level of ROS generation in the salmon macrophage-like cells. The NAD⁺ content as well as the NAD⁺ /NADH ratio increased in curdlan and LPS + curdlan-stimulated cells compared to control cells, which indicated increased metabolic activity in the stimulated cells. Supporting these findings, gene analysis using real-time quantitative PCR showed that arginase-1 and IL-1ß genes were highly expressed in the stimulated cells.

[Analysis on the trend of innovation and development in the field of ophthalmology]

Objective: To systematically analyze the innovation and development trend in the field of ophthalmology. Methods: The latest ophthalmology funding program from the National Eye Institute and National Natural Science Foundation of China, and funding project for 2012 to 2016 from the National Institutes of Health, National Natural Science Foundation of China and National key research and development plan of China was collected. Using the comparative analysis method, the major ophthalmology funding areas at home and abroad were analyzed. Papers published in 2012 to 2016 in the field of ophthalmology were collected from the Web of Science Core Collection, among which ESI highly cited papers and hot papers were particularly selected. Using bibliometric methods, the time trend of the number of papers and the citation frequency were analyzed. Using the co-occurrence cluster analysis method, the continued focuses and emerging concerns of ophthalmology papers was analyzed. Results: The funding plan of the National Eye Institute mainly covers nine major diseases in ophthalmology. NSFC focuses on retinal damage and repair mechanisms. The National Key Research and Development Program of China focuses on research on high-end ophthalmic implants. NIH continues to focus on the molecular mechanisms of blinding eye disease such as diabetic retinopathy, age-related macular degeneration, glaucoma, corneal disease and cataracts, basic research in genetics, and advanced diagnostic techniques such as imaging. Latest areas of interest involve gene editing techniques and the application of stem cell technology in ophthalmology. In China, research and application of stem cells in ophthalmic diseases, intraocular sustained-release drug carrier, and precision medicine research in ophthalmology are emerging areas of funding. In 2012 to 2016, research topics of 168 papers collected by ESI focused on macular degeneration, retinal diseases, glaucoma and other eye diseases. How to quickly promote new drugs and new technological achievements to the clinical application is a problem in the field of ophthalmology. How to change the ophthalmology clinic model, so as to provide patients with convenient and quality service, has become a research topic that needs to be given attention to. Conclusions: Based on the multidimensional analysis of innovation and development in the field of ophthalmology, cross application and integration of ophthalmology and high - tech fields such as advanced imaging technology, stem cell technology, gene editing technology, molecular targeting, and artificial intelligence will provide a strong basis for the enhancement of China's ophthalmology research innovation and international competitiveness. Research efforts for ophthalmic transformation should be strengthened, in order to realize the clinical application of the achievements as soon as possible. (Chin J Ophthalmol, 2018, 54: 452-463).

Downregulation of guanine nucleotide-binding protein beta 1 (GNB1) is associated with worsened prognosis of clearcell renal cell carcinoma and is related to VEGF signaling pathway

PURPOSE

Clear-cell renal cell carcinoma (ccRCC) is characterized by genetic abnormalities, while the role of Guanine Nucleotide-Binding Protein Beta 1 (GNB1) in ccRCC has not been studied. We thus aimed to evaluate the expression and prognostic value of GNB1 in ccRCC.

METHODS

A two-stage study (exploration and validation) was conducted using in silico and immunohistochemical (IHC) scoring of ccRCC samples from our institute, to evaluate the association between GNB1 expression and clinicopathological parameters of ccRCC patients. Pathway analyses were performed for genes coexpressed with GNB1 using the KOBAS platform to profile the function of GNB1 and IHC validation.

RESULTS

In the exploration stage, data from TCGA ccRCC dataset were reproduced, which contained 537 patients with ccRCC and found that downregulation of GNB1 was significantly associated with worse prognosis. IHC staining from the Human Protein Atlas showed significantly downregulation of GNB1 in ccRCC tissue compared with normal kidney. Pathway analysis showed significantly altered vascular endothelial growth factor (VEGF) signaling pathways among which expressions of 3 genes (WASF2, NRP1, and HIP1) were significantly associated with GNB1 expression, respectively. In the validation stage, included were 80 ccRCC samples and GNB1 expression was scored using IHC positivity. GNB1 expression was negatively associated with tumor stage, lymph node invasion, metastasis, older age, and increased tumor grade. Female gender and receiving neoadjuvant therapy were also associated with decreased GNB1 expression. The expressions of WASF2, NRP1 and HIP1 were also studied and found that they were significantly associated with GNB1.

CONCLUSION

GNB1 was downregulated in ccRCC. Decreased GNB1 expression was associated with worsened disease characteristics and prognosis. GNB1 was related with VEGF signaling in ccRCC, implying a therapeutic potential of this factor.

Reduced risk of relapse after long-term nucleos(t)ide analogue consolidation therapy for chronic hepatitis B

BACKGROUND

Before stopping nucleos(t)ide analogue (NA) treatment in chronic hepatitis B (CHB), 6-12 months of consolidation therapy is recommended.

AIM

To investigate the effect of consolidation therapy on off-treatment outcomes in CHB patients.

METHODS

We included 94 patients who stopped NA after at least 1 year of therapy. Patients could be HBeAg-positive or HBeAg-negative at start-of-treatment, but were HBeAg-negative and had undetectable HBV DNA at time of discontinuation. Consolidation therapy was defined as treatment after the first undetectable HBV DNA (and HBeAg loss for HBeAg-positive patients) until NA cessation.

RESULTS

At 3 years, 74% of the start-of-treatment HBeAg-positive and 75% of the start-of-treatment HBeAg-negative patients developed HBV DNA >2000 IU/mL at a single time point, whereas a persistent virological relapse (≥2 tests of HBV DNA >2000 IU/mL 6 months apart within 1 year) developed in 49% of the start-of-treatment HBeAg-positive and 53% of the start-of-treatment HBeAg-negative patients. For both HBeAg-positive and HBeAg-negative patients, consolidation therapy of ≥3 years was associated with lower persistent virological relapse rates compared to <1 year (1-year relapse rate: 25% vs. 54%; P = 0.063 and 24% vs. 57%; P = 0.036, respectively). At 3 years, 9% of the HBeAg-positive and 14% of the HBeAg-negative patients became HBsAg-negative. Prolonged consolidation therapy increased the likelihood of HBsAg loss. Two cirrhotic patients developed hepatic decompensation but both recovered.

CONCLUSIONS

After nucleos(t)ide analogue discontinuation, relapse was common in patients with chronic hepatitis B. Prolongation of consolidation therapy beyond 3 years decreased the risk of persistent virological relapse and increased the likelihood of HBsAg loss.

Proposal for photonic quantization with differential encoding using a phase modulator and delay-line interferometers

A photonic quantization approach to implementing analog-to-digital conversion (ADC) in the optical domain with differential encoding employing a phase modulator and delay-line interferometers (DLIs) is proposed and demonstrated. In the proposed ADC system, the phase-modulated signal is sent to an array of DLIs that have identical time delay difference, but different phase shifts, which are employed to achieve quantization with differential encoding. A proof-of-concept experiment is performed. The quantization of a 10 GHz sinusoidal signal with a bit length of 4 is experimentally demonstrated.

Frequency of PIK 3CA Mutations in Chinese HER2+ Metastatic Breast Cancer Patients and Association with Clinical Benefit to Lapatinib and Capecitabine Treatment

Background: Activating mutations in PIK3CA are frequent in breast cancer (Campbell et al. Cancer Res 2004;64:7678-7681). Previous analyses suggest that the presence of PIK3CA activating mutations were associated with poor clinical outcome (Li et al. Breast Can Res Treat 2006;96:91-95) and could confer resistance to treatment with trastuzumab (T) (Berns et al. Cancer Cell 2007;12:395-402). Lapatinib (L) is an oral tyrosine kinase inhibitor targeting EGFR and HER2 pathways. L plus capecitabine (C) has demonstrated efficacy in women with HER2+ metastatic breast cancer (MBC) previously treated with T (Geyer et al. N Engl J Med 2006;355(26):2733-2743). EGF109491 evaluated the efficacy of L+C in 52 Chinese HER2+ MBC patients. The clinical benefit rate (CBR) was 57.7% (PR 44% and SD 44%) and median progression free survival (PFS) was 6.3 months. The purpose of this analysis was to establish the frequency of PIK3CA mutations in this small cohort of Chinese patients and to determine if the presence of a PIK3CA mutation has any impact on clinical benefit to L+C.Methods: 38/52 patients provided tumor samples for biomarker analysis. Briefly, DNA was extracted from these tumor samples, amplified by PCR and sequenced by Pyrosequencing methods to identify the presence of frequent activating mutations in exons 9 and 20 in PIK3CA. Mutation status was tested for association with CBR and PFS using contingency table analysis and proportional hazards analysis respectively.Results:11/38 (29%) patients harbored a mutation in the PIK3CA gene, consistent with published frequencies. 9/11 mutations reside in the catalytic domain and 2/11 mutations reside in the accessory domain of the gene. There was no statistical association with CBR (p=0.639) or PFS (HR=1.01, p=0.989) in PIK3CA wildtype patients vs. PIK3CA mutant patients. PIK3CA wildtype n=27 (%)PIK3CA Mutation n=11 (%)CR0 (0)0 (0)PR12 (44%)4 (36%)SD13 (48%)5 (45%)PD1 (4%)1 (9%)Unknown1 (4%)1 (9%)HR1.01 (p=0.989) Conclusion: The frequency of PIK3CA mutations in this small cohort of Chinese HER2+ MBC patients is consistent with published frequencies. There was no statistically significant association between the presence of a PIK3CA mutation and clinical benefit to L+C in these patients. These results are in agreement with previous reports that mutations in PIK3CA do not seem to impact clinical outcome following L-containing treatment regimens.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1140.

Impact of glyphosate on the development, fertility and demography of Chrysoperla externa (Neuroptera: Chrysopidae): ecological approach

Few ecotoxicological studies have used life table analysis to evaluate the toxicity of pesticides on beneficial organisms. This study is the first report of the effect of the herbicide glyphosate on a predator insect, Chrysoperla externa, using a demographic approach. This predator is associated to soybean pests and has a potential role as a biological control agent in the Neotropical Region. The objective of this work was to evaluate the side-effects of glyphosate on the development, fertility and demography of C. externa, treated orally by ingestion of glyphosate-dipped eggs of Sitotroga cerealella in laboratory conditions. The data were analyzed using the age-stage, two-sex life table. Development from third larval instar to pupae and adult longevity were shorter in glyphosate-treatment than in the control. Adult pre-reproductive period was longer in glyphosate-treatment than in the control. Fecundity and fertility were deeply reduced, as well, being fertility greater affected. A high important reduction was registered in all population parameters. Most eggs from glyphosate-treated cohort looked abnormal, smaller than control, dehydrated and became black 2d after oviposition. In addition, adults developed tumours in the abdomen region at 20d after emergence, being the effect more drastic in females than males. It is beyond the scope of our study to speculate on the effects of this herbicide on C. externa field populations. However, it seems likely that populations under continuous use of glyphosate would be exposed at greater detrimental effects in the long term.

Enhanced biological phosphorus removal in the retrofitting from an anoxic selector to an anaerobic selector in a full-scale activated sludge process in Singapore

This paper presents the investigation results of retrofitting an anoxic selector to an anaerobic selector through stepwise reduction of air supply in a full-scale activated sludge process with a focus on enhanced biological phosphorus removal (EBPR). The process experienced gradual shift from a Ludzack-Ettinger (LE) to an anaerobic-anoxic-oxic (A(2)O) process and subsequently, an anaerobic-oxic (A/O) process. The major findings are: (i) the average influent-based PO(4) (3-)-P release in the anaerobic selector compartment was 16.3 mg P l(-1) and that in the secondary clarifier was 1.7 mg P l(-1). 75% of the SCOD and 93% of the acetic acid in the primary effluent were taken up in the anaerobic selector compartment, respectively; (ii) PO(4) (3-)-P uptake contributed by both aerobic and denitrifying phosphorus accumulating organisms (DPAOs) occurred mainly in the first and second aerobic lanes together with simultaneous nitrification and denitrification (SND) while there was not much contribution from the last aerobic lane; (iii) The average PO(4) (3-)-P concentration of the final effluent was 2.4 mg P l(-1) corresponding to a removal efficiency of 85%; (iv) the SVI was satisfactory after retrofitting; and (v) the increase of NH(4) (+)-N in the final effluent from the commencement to the completion of the retrofitting resulted in an approximate 40-50% reduction in oxygen demand and a significant aeration energy saving was achieved.

Median liver lobe of woodchuck as a model to study hepatic outflow obstruction: a pilot study

BACKGROUND

Hepatic vein outflow obstruction represents an important clinical problem in living-liver transplantation. An animal model is required to study the influence of outflow obstruction on the intrahepatic regulation of liver perfusion and the subsequent effects on liver injury and recovery during liver regeneration. The size of woodchucks enables the use of standard clinical imaging procedures.

AIM

This study aims at describing hepatic vascular and territorial anatomy of the woodchuck liver based on a virtual three-dimensional (3D) visualization of the hepatic vascular tree.

METHODS

Woodchucks (n=6) were subjected to an all-in-one computed tomography (CT) after contrasting the vascular and the biliary tree. CT-images were used for 3D-reconstruction of hepatic and portal veins and calculation of the corresponding portal and hepatic vein territories and their respective volume using hepavision (MeVisLab). A virtual resection was performed following the Cantlie-line and territories at risk were calculated.

RESULTS

The median lobe of the woodchuck liver has a similar vascular supply and drainage as the human liver with two portal (right and left median portal vein) and three hepatic veins (left, middle and right median hepatic vein). The corresponding portal and hepatic vein subterritories are of a similar relative size compared with the human liver. Virtual splitting of the median lobe of the woodchuck liver revealed areas at risk of focal outflow obstruction, as observed clinically.

CONCLUSION

The median liver lobe of the woodchuck represents, to a small extent, the hepatic vascular anatomy of the human liver and is therefore a suitable potential model to correlate repeated imaging of impaired liver perfusion with histomorphological findings of liver damage and regeneration.

Simultaneous measurement of axial strain, temperature, and transverse load by a superstructure fiber grating

A novel and simple fiber-optic sensor based on a superstructure fiber grating for simultaneous measurement of temperature, axial strain, and transverse load is proposed and demonstrated. By measurement of the shift and split of broadband and narrow-band loss peaks, one can determine the temperature, axial strain, and transverse load simultaneously over the ranges 0-140 degrees , 0-1200muepsilon, and 0-0.3 kg/mm, respectively.

Pediatric Salmonella enterocolitis in a teaching hospital in Taitung: A four-year analysis

In order to understand the childhood Salmonella enterocolitis in Taitung, we retrospectively collected the patients with the diagnosis of acute enterocolitis who were admitted to the pediatric wards of Taitung branch of Mackay Memorial Hospital from January 1, 1995 to December 31, 1998. Salmonella enterocolitis accounted for 16.8% of the total cases of acute enterocolitis. The mean age of the patients was 14.6 +/- 14.1 months old. Seventy-nine patients were male and 78 patients were female. Eighty-two patients lived in the urban area and 75 patients lived in the suburbs. The mean duration from onset of illness to admission was 2.6 +/- 1.9 days. The mean duration of hospitalization was 6.6 +/- 4.8 days. The peak incidence was in August and September. The most common clinical manifestations were fever (74.5%) and blood stool (46.5%). In 157 patients, Salmonella serogroup B was isolated from stool in 115 patients. The rate of bacteremia was 4.5%. Serogroup D accounted for 28.6% of the bacteremia. Two patients developed meningitis and one patient had osteomyelitis. Of 88 patients examined for rotavirus, 12 had positive results. There was neither bowel perforation nor mortality recorded in our study.

Somatic mutation and germline variants of MINPP1, a phosphatase gene located in proximity to PTEN on 10q23.3, in follicular thyroid carcinomas

Various genes have been identified to play a role in the pathogenesis of follicular thyroid tumors. Cowden syndrome is the only known familial syndrome with an increased risk of both follicular thyroid adenoma (FA) and carcinoma (FTC). Germline mutations in the tumor suppressor gene PTEN, which encodes a dual-specificity phosphatase, have been found in up to 80% of patients with Cowden syndrome suggesting a role of PTEN in the pathogenesis of follicular thyroid tumors. Although somatic intragenic mutations in PTEN, which maps to 10q23.3, are rarely found in follicular tumors, loss of heterozygosity (LOH) of markers within 10q22-24 occurs in about 25%. Recently, another phosphatase gene, MINPP1, has been localized to 10q23.3. MINPP1 has the ability to remove 3-phosphate from inositol phosphate substrates, a function that overlaps that of PTEN. Because of this overlapping function with PTEN and the physical location of MINPP1 to a region with frequent LOH in follicular thyroid tumors, we considered it to be an excellent candidate gene that could contribute to the pathogenesis of follicular thyroid tumors. We analyzed DNA from tumor and corresponding normal tissue from 23 patients with FA and 15 patients with FTC for LOH and mutations at the MINPP1 locus. LOH was identified in four malignant and three benign tumors. One of these FTCs with LOH was found to harbor a somatic c.122C > T or S41L mutation. We also found two germline sequence variants, c.809A > G (Q270R) and IVS3 + 34T > A. The c.809A > G variant was found in only one patient with FA but not in patients with FTC or normal controls. More interestingly, IVS3 + 34T > A was found in about 15% of FA cases and normal controls but not in patients with FTC. These results suggest a role for MINPP1 in the pathogenesis of at least a subset of malignant follicular thyroid tumors, and MINPP1 might act as a low penetrance predisposition allele for FTC.

Targeted deletion of Minpp1 provides new insight into the activity of multiple inositol polyphosphate phosphatase in vivo

Multiple inositol polyphosphate phosphatase (Minpp1) metabolizes inositol 1,3,4,5,6-pentakisphosphate (InsP(5)) and inositol hexakisphosphate (InsP(6)) with high affinity in vitro. However, Minpp1 is compartmentalized in the endoplasmic reticulum (ER) lumen, where access of enzyme to these predominantly cytosolic substrates in vivo has not previously been demonstrated. To gain insight into the physiological activity of Minpp1, Minpp1-deficient mice were generated by homologous recombination. Tissue extracts from Minpp1-deficient mice lacked detectable Minpp1 mRNA expression and Minpp1 enzyme activity. Unexpectedly, Minpp1-deficient mice were viable, fertile, and without obvious defects. Although Minpp1 expression is upregulated during chondrocyte hypertrophy, normal chondrocyte differentiation and bone development were observed in Minpp1-deficient mice. Biochemical analyses demonstrate that InsP(5) and InsP(6) are in vivo substrates for ER-based Minpp1, as levels of these polyphosphates in Minpp1-deficient embryonic fibroblasts were 30 to 45% higher than in wild-type cells. This increase was reversed by reintroducing exogenous Minpp1 into the ER. Thus, ER-based Minpp1 plays a significant role in the maintenance of steady-state levels of InsP(5) and InsP(6). These polyphosphates could be reduced below their natural levels by aberrant expression in the cytosol of a truncated Minpp1 lacking its ER-targeting N terminus. This was accompanied by slowed cellular proliferation, indicating that maintenance of cellular InsP(5) and InsP(6) is essential to normal cell growth. Yet, depletion of cellular inositol polyphosphates during erythropoiesis emerges as an additional physiological activity of Minpp1; loss of this enzyme activity in erythrocytes from Minpp1-deficient mice was accompanied by upregulation of a novel, substitutive inositol polyphosphate phosphatase.

[Risk factors of type 2 diabetes in Shenzhen]

OBJECTIVE

The study was designed to investigate the risk factors of Type 2 diabetes in the new city Shenzhen.

METHODS

A representative sample of 8,182 adults aged over 20 to 75 years old were randomly selected in the residents of Shenzhen, China in 1997. Type 2 diabetes was diagnosed according to the WHO criteria. Questionnaire survey, anthropometric measurement and blood analysis were carried out, and logistic regression analysis was used to study the risk factors.

RESULTS

The results showed that the prevalence of type 2 diabetes in subjects with high total cholesterol were 4.9 times of those with lower TC value. Subjects with high triglyceride had a prevalence 5.7 times of those who had lower TG. Those HDL-ch had a prevalence 68.7% higher than those with normal HDL-ch value; on the other hand, those HDL-ch > 1.91 mmol/L were 44.6% lower in the prevalence than those with normal HDL-ch. The prevalence of type 2 diabetes in subjects with BMI >or= 25 were 2.6 times of those with BMI < 25. Subject with hypertension (>or= 140/90 mm Hg) had a prevalence 3.8 times of those with normal blood pressure. Subjects with family history of type II diabetes had a prevalence 2.0 times of no family history, and women who had delivered babies over 4 kg had a prevalence 1.9 times of those who had babies less than 4 kg. Subjects with waist/hip ratio (WHR) >or= 1.0 had a prevalence 5.1 times of those with WHR < 1.0. The prevalence of type 2 Diabetes was higher with increasing amount of cigarette smoking and the duration (in years) of smoking or increasing drinking (alcohol) and the duration (in years) of drinking.

CONCLUSIONS

The blood glucose level was found to be positively correlated with TC or TG, and negatively correlated with HDL-ch. This study demonstrated again that TC, TG, HDL-ch, obesity, hypertension, family history of type 2 diabetes and in women, delivery of babies over 4 kg and age were risk factors of type 2 diabetes.

A modular neural network architecture for pattern classification based on different feature sets

We propose a novel connectionist method for the use of different feature sets in pattern classification. Unlike traditional methods, e.g., combination of multiple classifiers and use of a composite feature set, our method copes with the problem based on an idea of soft competition on different feature sets developed in our earlier work. An alternative modular neural network architecture is proposed to provide a more effective implementation of soft competition on different feature sets. The proposed architecture is interpreted as a generalized finite mixture model and, therefore, parameter estimation is treated as a maximum likelihood problem. An EM algorithm is derived for parameter estimation and, moreover, a model selection method is proposed to fit the proposed architecture to a specific problem. Comparative results are presented for the real world problem of speaker identification.

Improved learning algorithms for mixture of experts in multiclass classification

Mixture of experts (ME) is a modular neural network architecture for supervised learning. A double-loop Expectation-Maximization (EM) algorithm has been introduced to the ME architecture for adjusting the parameters and the iteratively reweighted least squares (IRLS) algorithm is used to perform maximization in the inner loop [Jordan, M.I., Jacobs, R.A. (1994). Hierarchical mixture of experts and the EM algorithm, Neural Computation, 6(2), 181-214]. However, it is reported in literature that the IRLS algorithm is of instability and the ME architecture trained by the EM algorithm, where IRLS algorithm is used in the inner loop, often produces the poor performance in multiclass classification. In this paper, the reason of this instability is explored. We find out that due to an implicitly imposed incorrect assumption on parameter independence in multiclass classification, an incomplete Hessian matrix is used in that IRLS algorithm. Based on this finding, we apply the Newton-Raphson method to the inner loop of the EM algorithm in the case of multiclass classification, where the exact Hessian matrix is adopted. To tackle the expensive computation of the Hessian matrix and its inverse, we propose an approximation to the Newton-Raphson algorithm based on a so-called generalized Bernoulli density. The Newton-Raphson algorithm and its approximation have been applied to synthetic data, benchmark, and real-world multiclass classification tasks. For comparison, the IRLS algorithm and a quasi-Newton algorithm called BFGS have also been applied to the same tasks. Simulation results have shown that the use of the proposed learning algorithms avoids the instability problem and makes the ME architecture produce good performance in multiclass classification. In particular, our approximation algorithm leads to fast learning. In addition, the limitation of our approximation algorithm is also empirically investigated in this paper.

Multiple inositol polyphosphate phosphatase: evolution as a distinct group within the histidine phosphatase family and chromosomal localization of the human and mouse genes to chromosomes 10q23 and 19

Multiple inositol polyphosphate phosphatase is the only enzyme known to hydrolyze the abundant metabolites inositol pentakisphosphate and inositol hexakisphosphate. We have previously demonstrated that the chick homolog of multiple inositol polyphosphate phosphatase, designated HiPER1, has a role in growth plate chondrocyte differentiation. The relationship of these enzymes to intracellular signaling is obscure, and as part of our investigation we have examined the murine ((MMU)Minpp1) and human ((HSA)MINPP1) homologs. Northern blot analysis demonstrated expression of ((MMU)Minpp1 in a variety of mouse tissues, comparable to the expression of other mammalian homologs, but less restricted than the expression of HiPER1 in chick. A purified (MMU)Minpp1 fusion protein cleaved phosphate from inositol (1,3,4,5)-tetrakisphosphate and para-nitrophenyl phosphate. When the presumptive active site histidine was altered to alanine by site-directed mutagenesis, enzyme activity was abolished, confirming the classification of (MMU)Minpp1 as a histidine phosphatase. The amino acid sequences of the murine and human MINPP proteins share >80% identity with the rat enzyme and >56% identity with HiPER1, with conservation of the C-terminal consensus sequence that retains proteins in the endoplasmic reticulum. The intron/exon structure of the mammalian (MMU)Minpp1 and (HSA)MINPP1 genes is also conserved compared to the chick HiPER1 gene. Sequence analysis of plant and fruit fly MINPP homologs supports the hypothesis that the MINPP enzymes constitute a distinct evolutionary group within the histidine phosphatase family. We have mapped (HSA)MINPP1 to human chromosome 10q23 by fluorescence in situ hybridization, YAC screening, and radiation hybrid mapping. This assignment places (HSA)MINPP1 in a region of chromosome 10 that is frequently mutated in human cancers and places (HSA)MINPP1 proximal to the tumor suppressor PTEN, which maps to 10q23.3. Using a radiation hybrid panel, we localized (MMU)Minpp1 to a region of mouse chromosome 19 that includes the murine homolog of Pten. The evolutionary conservation of this novel enzyme within the inositol polyphosphate pathway suggests a significant role for multiple inositol polyphosphate phosphatase throughout higher eukaryotes.

[Detection of fetal DNA in maternal plasma using the nested polymerase chain reaction]

OBJECTIVE

To search for a new method of non-invasive prenatal gene diagnosis.

METHODS

A single-copy human DYS14 gene of Y-chromosome of fetal DNA sequence was amplified by nested polymerase chain reaction (PCR) from twelve pregnant maternal plasma (12-40 weeks). A 239 bp and 198 bp specific fragment were obtained. The maternal plasma samples of twelve pregnant women were used directly for nested PCR. RESULTS The fragment was identified in 8 of 10 male-bearing pregnant women plasma. The diagnostic accordance rate was 80% (8/10), 6 to 8 women gave positive signals in two consecutive amplifications, 2 of 8 women gave positive signals in the second amplification. The rate of positive was increased greatly by nested PCR (from 60% to 80%). None of the other 2 female-bearing pregnant women had positive results. The final accuracy of 83.3% (10/12) was attained in all cases.

CONCLUSION

The finding of circulating fetal DNA in maternal plasma may have new implications for non-invasive prenatal gene diagnosis, and the nested PCR possesses the advantages of sensitivity and specificity which improves the clinical application.