Usefulness of 3T diffusion-weighted MRI for discrimination of reactive and metastatic cervical lymph nodes in patients with oral squamous cell carcinoma: a pilot study

OBJECTIVES

To study the diagnostic accuracy of 3T diffusion-weighted MRI (DW-MRI) for the discrimination of reactive and metastatic cervical lymph nodes in patients with oral squamous cell carcinoma.

METHODS

DW T1 and T2 weighted MRI was performed in 25 patients with biopsy-proved primary oral squamous cell carcinoma. The mean apparent diffusion coefficient (ADC) values of 30 histopathologically proved reactive lymph nodes and 21 histopathologically proved metastatic lymph nodes were compared using an unpaired t-test. A cut-off ADC value with optimal diagnostic sensitivity, specificity and area under the curve in discrimination of the two groups was determined using a receiver operating characteristic curve analysis.

RESULTS

The mean ADC values of reactive lymph node and metastatic lymph node groups were (1.037 ± 0.149) × 10(-3) and (0.702 ± 0.197) × 10(-3) mm(2) s(-1), respectively. A statistically significant difference in ADC values of the two groups was certified (p < 0.0001). An optimal ADC threshold value of 0.887 × 10(-3) mm(2) s(-1) was suggested as the cut-off point, which resulted in 93.33% sensitivity, 80.95% specificity, 88.20% accuracy and area under curve of 0.887.

CONCLUSIONS

Our preliminary study indicates that the addition of 3T DW-MRI may be useful for discriminating between reactive lymph nodes and metastatic lymph nodes in patients with oral squamous cell carcinoma. However, larger studies are still required to validate our results and to standardize this imaging technique for daily clinical practice.

Online learning control by association and reinforcement

This paper focuses on a systematic treatment for developing a generic online learning control system based on the fundamental principle of reinforcement learning or more specifically neural dynamic programming. This online learning system improves its performance over time in two aspects: 1) it learns from its own mistakes through the reinforcement signal from the external environment and tries to reinforce its action to improve future performance; and 2) system states associated with the positive reinforcement is memorized through a network learning process where in the future, similar states will be more positively associated with a control action leading to a positive reinforcement. A successful candidate of online learning control design is introduced. Real-time learning algorithms is derived for individual components in the learning system. Some analytical insight is provided to give guidelines on the learning process took place in each module of the online learning control system.

Principle component feature detector for motor cortical control

Principle component analysis (PCA) was performed on recorded neuronal action potentials from neural ensembles in rat's motor cortex when the rat was involved in a closed-loop real-time brain machine interface (BCI). The implanted rat was placed in a conditioning chamber, but freely moving, to decide which one of the two paddles should be activated to shift the light to the center. It is found that the principle component feature vectors revealed the importance of individual neurons and their temporal dynamics in relation to the intention of activating either left or right paddle. In addition, the first principle component feature has much higher discriminative capability than others although it represents only a few percentage of the total variance. Using the first principle component with the Bayes classifier achieved 90% classification accuracy, which is comparable with the accuracy obtained by a more sophisticated high performance support vector classifiers.

Schistosoma japonicum triose-phosphate isomerase plasmid DNA vaccine protects pigs against challenge infection

The protective efficacy of a Schistosoma japonicum, Chinese strain, triose-phosphate isomerase (TPI) plasmid DNA vaccine was examined in naïve pigs. Pigs were vaccinated with the TPI DNA-plasmid alone, or in conjunction with IL-12 as pcDNA3.1-P35, pcDNA3.1-P40 plasmids via intramuscular injection. Control pigs were immunized with equivalent amounts of pcDNA3.1. Pigs were immunized 3 times at 21-day intervals and challenged 30 days after the final boost. Forty-five days post-challenge, pigs were sacrificed and perfused to compare adult worm burdens, female worm burdens, liver egg burdens and granuloma size. We found that pigs vaccinated with SjCTPI DNA alone had adult worm burdens reduced by 48.3% and that a further decrease in adult worm burdens was not seen in the group vaccinated with SjCTPI DNA in conjunction with IL-12 (46.2% reduction). The SjCTPI DNA vaccines had a more pronounced effect on reducing female worm burdens i.e. 53.6% SjCTPI alone and 59.6% for SjCTPI+IL-12. Vaccination with SjCTPI-DNA reduced liver eggs by 49.4% and this response was significantly enhanced by the addition of IL-12 (65.8% reduction in liver eggs). In addition to the dramatic protective effects seen in vaccinated pigs, we also noted that granuloma size was reduced by 42% in both groups. Thus, vaccination of pigs and other large animals in China with SjCTPI DNA vaccine will likely reduce transmission by reducing adult worm burdens and worm egg output and simultaneously reduce hepatic egg-associated pathology.

Validation of the in vitro gastrointestinal (IVG) method to estimate relative bioavailable lead in contaminated soils

The effect of the dosing vehicle (e.g., dough) on the ability of an in vitro gastrointestinal (IVG) method to predict relative bioavailable Pb associated with soil ingestion was evaluated. Bioaccessible Pb determined by the IVG method was compared with relative bioavailable Pb measured from dosing trials using juvenile swine for 18 contaminated soils ranging from 1270 to 14200 mg Pb kg(-1). Bioaccessible Pb was measured in the IVG gastric extraction (GE) and intestinal extraction (IE) solutions. Mean bioaccessible Pb values were 32.2% for GE without dough, 23.0% for GE with dough, 1.06% for IE without dough, and 0.56% for IE with dough. It is possible that phytic acid associated with the dough addition decreased bioaccessible Pb. In vivo relative bioavailable Pb ranges for different swine tissues were 1 to 87% for blood, 0 to 110% for liver, 1 to 124% for kidney, and 0.04 to 94% for bone. Strong linear relationships between IVG GE Pb with dough (r > 0.76, P < 0.0002), IVG IE Pb with dough (r > 0.56, P < 0.015), and IVG GE Pb without dough (r > 0.81, P < 0.0001) and in vivo bioavailable Pb as estimated with blood, kidney, liver, and bone were found. Inexpensive in vitro methods may be useful in providing an estimate of the variability in relative bioavailable Pb at a single study site. The IVG method can be used to estimate relative bioavailable Pb, As, and Cd in contaminated soil.

[Protective immunity induced by 23 kDa membrane protein DNA vaccine of Schistosoma japonicum Chinese strain in mice]

OBJECTIVE

To develop 23 kDa membrane protein DNA vaccine of Schistosoma japonicum Chinese strain and test its protective efficacy in infected C57BL/6 mice.

METHODS

The full length cDNA encoding SjC23 amplified from pUC19-SjC23 subcloned into pcDNA3.1. 48 female mice were divided into three groups: A, B and C. Group A (control group) was each immunized i.m. with 100 micrograms of pcDNA3.1; group B (SjC23 group) was each immunized i.m. with 100 micrograms of pcDNA3.1-SjC23; group C (SjC23 + IL-12) was each immunized i.m. with a mixture of 100 micrograms of pcDNA3.1-SjC23, 100 micrograms of pcDNA3.1-p35 and 100 micrograms of pcDNA-p40, followed by two boosts of the same DNA once every two weeks. All the mice were challenged with 45 cercariae at week 8, killed and perfused for worms at week 14. The expression of SjC23 and p35, p40 in muscle tissue was determined by immuno-histochemical method. By the culture of spleen cells, the production of IL-2, IL-4, IL-10 and IFN-gamma after the stimulation of rSjC23-HD was determined two weeks before and after challenge. Anti-SjC23 antibodies were tested by Western blotting.

RESULTS

SjC23 and p35, p40 were all expressed on the membrane and in the plasma of muscle cells of the infected mice. Significant increase of IL-2 and IFN-gamma in SjC23 and SjC23 + IL-12 groups was observed before and after challenge. Western blotting showed that after the third immunization (before challenge) 8 out of 10 sera from SjC23 group and 9 out of 10 sera from SjC23 + IL-12 group were positive. The worm reduction rate in SjC23 group and SjC23 + IL-12 group was 26.9% and 35.4%, respectively; the number of eggs in liver tissue was reduced by 22.2% and 28.4%, respectively.

CONCLUSION

pcDNA3.1-SjC23 DNA vaccine could induce partial protection against Schistosoma japonicum in C57BL/6 mice.

Establishment of an animal model of chronic atrophic gastritis and a study on the factors inducing atrophy

OBJECTIVE

To establish a rat model of chronic atrophic gastritis and explore the factors inducing atrophy.

METHODS

In accordance with repeated orthogonal design of L8(2(7)), 60% alcohol and 20 mmol/L sodium deoxycholate (served as factor A), 0.05%-0.1% ammonia water (factor B), 0.05% indomethacin (factor C) were given, alone or in combination, to rats in three experiments for 3 months, 6 months or 9 months respectively. Then the rats were dissected, and their pathologic changes of the gastric mucosa were assessed.

RESULTS

Typical signs of chronic atrophic gastritis (CAG) were found in all rats which were treated with factor A, B, C alone or in combination for 6 or 9 months. No significant difference of pathologic changes of gastric mucosa was found between the rats treated for 6 months and those for 9 months. No obvious CAG signs were found in the rats treated with factor A, B, C for 3 months.

CONCLUSION

Sixty percent of alcohol, 20 mmol/L sodium deoxycholate, 0.05%-0.1% ammonia water and 0.05% indomethacin given to Sprague-Dawley rats for 6 months can successfully establish the animal model of CAG. Prolongation of the model-establishment time is not able to further facilitate the atrophy of gastric mucosa.

Relationship of dietary lysine level to the concentration of all essential amino acids in broiler diets

A study was conducted to evaluate the relationship of dietary Lys and other essential amino acids (EAA) in diets for broilers. Diets were formulated based upon NRC (1994) recommendations. Within each age period, diets contained NRC recommended levels of Lys with other EAA at 100, 110, 120, or 130% of NRC. The diets were then supplemented with 0.1, 0.2, or 0.3% additional Lys, resulting in a 4 x 4 factorial arrangement with four levels of Lys (NRC, + 0.1%, + 0.2%, and + 0.3% Lys) and four levels of other EAA (100, 110, 120, and 130% of NRC). Each of the 16 treatments was fed to six replicate pens of 25 male broilers of a commercial strain. At 56 d, five birds per pen were processed to determine dressing percentage and carcass yield. There were no significant interactions between level of Lys and levels of other EAA for live performance or carcass characteristics. The BW was significantly increased at 21 and 42 d by addition of + 0.1% Lys above NRC but not at 56 d. There was no significant effect of other EAA on BW at any age. The effects of Lys on feed conversion were varied. At 21 and 42 d, addition of 0.1% Lys to diets containing the NRC Lys level significantly improved feed conversion; response to 0.2 or 0.3% Lys were varied. No significant effects of Lys on feed conversion were observed at 56 d. Increasing the level of EAA resulted in significant improvements in feed conversion at 21, 42, and 56 d, generally following a linear trend. Dietary Lys levels had no significant effects on dressing percentage, breast meat yield, or abdominal fat content. The level of other EAA significantly influenced dressed yield but had no significant influence on carcass yield. These results indicate that NRC (1994) levels of Lys and other EAA are adequate for optimum performance of male broilers processed at 56 d but may be less than adequate at younger ages.

Photoinduced stable second-harmonic generation in chalcogenide glasses

We report on photoinduced second-harmonic generation (SHG) in chalcogenide glasses. Fundamental and second-harmonic waves from a nanosecond pulsed Nd:YAG laser were used to induce second-order nonlinearity in chalcogenide glasses. The magnitude of SHG in 20G?20A?60S glass was 10(4) larger than that of tellurite glass with a composition of 15Nb(2)O (5) 85TeO(2) (mol.%). Moreover, no apparent decay of photoinduced SHG in 20G?20A?60S glass was observed after optical poling at room temperature. We suggest that the large and stable value of chi((2)) is due to the induced defect structures and large chi((3)) of the chalcogenide glasses.

[The effect of epidermal growth factor on the pathologic changes of gastric mucosa in SD rats with chronic atrophic gastritis]

OBJECTIVE

To study the effect of epidermal growth factor (EGF) on the pathologic changes of gastric mucosa in rats with chronic atrophic gastritis(CAG).

METHODS

The established rat models of CAG were divided into therapy group and control group. The rats in the therapy group received EGF 10 microg/kg subcutaneously (SC), whereas these in the control group the same volume of normal saline SC. 12 weeks later, all rats were killed by cervical dislocation and their gastric mucosa were examined with microscope.

RESULTS

The grade of inflammatory cell infiltration in the therapy group was lower than that in the control group (P < 0.01). The thickness of gastric mucosal gland layer was (215.0 +/- 20.7) microm in the therapy group and (139.2 +/- 13.8) microm in the control group (P < 0.01). The ratio of the thickness of gastric mucosal glands and muscularis mucosa(L(1)/L(2)) was 2.70 +/- 0.34 in the therapy group and 1.27 +/- 0.27 in the control group (P < 0.01). The number of gastric glands in 1 mm length of mucosal layer was 26.20 +/- 1.27 in the therapy group and 19.90 +/- 1.78 in the control group (P < 0.01). In the therapy group, the gastric glands were rearranged in order, without signs of malignant proliferation. The width of the expression of proliferating cell nuclear antigen (PCNA ) of gastric mucosa was higher in the therapy group than in the control group [(77.70 +/- 4.16) microm vs (54.40 +/- 4.54) microm, P < 0.01].

CONCLUSIONS

EGF played a therapeutic role in reversing the gastric mucosal atrophy of the rats with CAG. It promoted the expression of PCNA, which induced a protective proliferation of the gastric mucosal lesions in the rats with CAG.

Changes in serum ammonia concentration in cirrhotic patients with Helicobacter pylori infection

OBJECTIVE

To study whether liver cirrhosis associated with Helicobacter pylori (H. pylori) infection will induce increased serum ammonia and whether the peripheral serum ammonia reflects the level of portal vein serum ammonia.

METHODS

Blood was taken from the portal vein and the cubital vein in cirrhotic patients with and without H. pylori infection and non-cirrhotic patients (splenic rupture) with and without H. pylori infection, and the serum ammonia was measured.

RESULTS

The mean levels of serum ammonia in the group of cirrhotic patients with H. pylori infection were 167.82 +/- 8.97 mumol/L (portal vein) and 142.2 +/- 13.35 mumol/L (cubital vein). They were increased significantly as compared with cirrhotic patients without H. pylori infection (47.68 +/- 12.03 mumol/L portal vein and 37.23 +/- 7.04 mumol/L cubital vein), and also compared with the groups of splenic rupture patients with and without H. pylori infection (P < 0.01). There was no significant difference between the serum ammonia level of the cubital vein and portal vein (P > 0.05).

CONCLUSIONS

H. pylori infection can induce an increase in serum ammonia in patients with liver dysfunction, and the peripheral serum ammonia measurement may replace the portal vein serum ammonia as a monitoring method. Eradication of H. pylori in cirrhotic patients may prevent hepatic encephalopathy (HE).

[Assay and L1 gene sequence analysis of human papillomavirus type 6 and 11 in condylomata acuminata]

OBJECTIVE

To determinate the prevalence of HPV type 6, 11 in condylomata acuminata, and analyze the sequence of L1 gene and its deduced L1 protein.

METHODS

PCR was used to amplify DNA sequences between E6 and E7 of HPV type 6 and 11. The PCR products were identified by the fragment length cleaved with restriction enzyme RsaI. L1 genes were amplified with high fidelity Taq, and cloned DNA sequences were detected by the dideoxynucleotide method.

RESULTS

In 34 examples of condylomata acuminata, HPV11 was found in 25 examples (73.5%), HPV6 in 15(44.1%), including HPV6 + HPV11 in 6(17.6%). In comparison with the prototypes there were 7-8 point mutations in HPV11 L1 gene and 3 in HPV6L1 gene. L1 encoded protein changes showed up only in 1-3 amino acids in the former cases.

CONCLUSION

Most of patients tested with condylomata acuminata are mainly infected by HPV11, the rest of them by HPV6 or by co-infection of two mixex types. Sequence analysis of L1 genes indicated that mutations were found in both HPV6 and 11, whereas deduced amino acid mutations in L1 protein were limited in HPV11 only.

Dynamic topology representing networks

In the present paper, we propose a new algorithm, namely the Dynamic Topology Representing Networks (DTRN) for learning both topology and clustering information from input data. In contrast to other models with adaptive architecture of this kind, the DTRN algorithm adaptively grows the number of output nodes by applying a vigilance test. The clustering procedure is based on a winner-take-quota learning strategy in conjunction with an annealing process in order to minimize the associated mean square error. A competitive Hebbian rule is applied to learn the global topology information concurrently with the clustering process. The topology information learned is also utilized for dynamically deleting the nodes and for the annealing process. Properties of the DTRN algorithm will be discussed. Extensive simulations will be provided to characterize the effectiveness of the new algorithm in topology preserving, learning speed, and classification tasks as compared to other algorithms of the same nature.

[Study on genuineness of traditional Chinese medicine cortex Magnoliae officinalis]

It's found that a significant correlation between the samples of Magnoliae officinalis from the provenance in phenols content and varieties or forms. The total content of magnolol and honokiol in its bark is usually used as an index to measure the quality. Therefore, Cortex Magnoliae officinalis produced in Sichuan and Hubei being considered genuinenss and good in quality, should be actually referred to local varieties. This conclusion can also reveals the nature and scientific connotation of genuineness on Cortex Magnoliae Officinalis.

Modified theory of photoinduced molecular polar alignment in azo polymers

An improvement on the simplified theory of all-optical poling [Chem. Phys. Lett. 286, 415 (1998)] is proposed. In this improvement the influence of the cis isomer is taken into account in the process of photoinduced molecular polar alignment. An analytical expression for the induced polar order in the steady-state regime is derived. This expression shows that, although the contribution to the photoinduced second-order susceptibility from the cis state itself can be neglected, the population of the cis state plays an important role. This result suggests the possibility that one can improve the induced polar order by increasing the poling temperature, so that thermal-assisted optical poling can be explained.