Development and application of isothermal amplification methods for rapid detection of F4 fimbriae producing Escherichia coli.

Enterotoxigenic Escherichia coli (ETEC) is the causative agent of a wide range of diseases, which are the important cause of illness and mortality in piglets. ETEC strains expressing F4 fimbriae are frequently associated with post-weaning diarrhea (PWD) and lead to great economic losses in swine production industry worldwide. The aim of this study was to establish a rapid and effective isothermal amplification method for detection of F4 fimbriae. Loop-mediated isothermal amplification (LAMP), Polymerase spiral reaction (PSR) and cross-priming ampli- fication (CPA) were used to develop and optimize the detection method first time. Subsequently, the specificity and sensitivity of these methods were evaluated, and the clinical samples were detected with these methods. All the F4-positive samples could produce ladder-like amplifica- tions products and lead the chromogenic substrate SYBR Green I produce green fluorescence, while in blank control and negative samples lack of this pattern or remained orange. The sensi- tivity of LAMP and CPA were 10 times higher than PSR method. Meanwhile, these three methods were validated with clinical samples, 7 were found positive, while 125 samples were negative, the testing results were consisted with the real-time PCR method. These findings suggested that the isothermal amplification based on the F4 fimbriae is a rapid, effective and sensitive method under resource constrains.

Methylation-sensitive amplified polymorphism analysis of Verticillium wilt-stressed cotton (Gossypium).

In this study, a methylation-sensitive amplification polymorphism analysis system was used to analyze DNA methylation level in three cotton accessions. Two disease-sensitive near-isogenic lines, PD94042 and IL41, and one disease-resistant Gossypium mustelinum accession were exposed to Verticillium wilt, to investigate molecular disease resistance mechanisms in cotton. We observed multiple different DNA methylation types across the three accessions following Verticillium wilt exposure. These included hypomethylation, hypermethylation, and other patterns. In general, the global DNA methylation level was significantly increased in the disease-resistant accession G. mustelinum following disease exposure. In contrast, there was no significant difference in the disease-sensitive accession PD94042, and a significant decrease was observed in IL41. Our results suggest that disease-resistant cotton might employ a mechanism to increase methylation level in response to disease stress. The differing methylation patterns, together with the increase in global DNA methylation level, might play important roles in tolerance to Verticillium wilt in cotton. Through cloning and analysis of differently methylated DNA sequences, we were also able to identify several genes that may contribute to disease resistance in cotton. Our results revealed the effect of DNA methylation on cotton disease resistance, and also identified genes that played important roles, which may shed light on the future cotton disease-resistant molecular breeding.

Increased human epididymis protein 4 in benign gynecological diseases complicated with chronic renal insufficiency patients.

We examined the serum concentration of human epididymis protein (HE4) in patients with benign gynecological diseases complicated with chronic renal deficiency and its significance in the differential diagnosis of benign and malignant gynecological diseases. Serum HE4 and cancer antigen 125 concentrations were detected by chemiluminescence. Clinically or pathologically confirmed gynecological diseases were grouped and retrospectively analyzed, including 50 cases of gynecological benign diseases, 35 cases of non-mucinous epithelial ovarian carcinoma, 36 cases of endometrial adenocarcinoma, 15 cases of gynecological benign diseases patients complicated with chronic renal deficiency, 15 cases of gynecological diseases without chronic renal deficiency, and 30 normal controls. Serum HE4 values in the ovarian cancer group, endometrial cancer group, gynecological benign diseases with chronic renal deficiency group, and chronic renal deficiency group were significantly increased compared with the benign gynecological diseases and normal control groups, showing a significant difference (P < 0.001). A comparison of 4 groups with high HE4 showed that the HE4 level in the 2 groups with renal deficiency were higher than those in the ovarian cancer and endometrial cancer groups, but the difference was not significant (P > 0.05); there was no significant difference between 2 groups with renal deficiency (P > 0.05). Serum concentration of HE4 was high in patients with chronic renal deficiency, which should be distinguished during differential diagnosis of gynecological benign and malignant tumors in patients with chronic renal deficiency to avoid misdiagnosis.

Identification and mapping of Rf-I an inhibitor of the Rf5 restorer gene for Cms-C in maize (Zea mays L.).

The restoration of the C-type cytoplasmic male sterility (Cms) has been a common agriculture practice in the production of hybrid seed for many years. In this study, a series of crosses between select sterile and restorer lines, as well as a backcross population of (Cms-C77 x 6233) x 6233, were used to investigate the restoration of C-type Cms. Our results demonstrated that there was an inhibitor of the Rf5 restorer gene. This inhibitor gene, Rf-I, maps to chromosome 7 and is tightly linked with SSR markers, umc2326 and umc2327, at a genetic distance 4.7 and 3.4 cM, respectively. After analyzing our data combined with previous studies, we propose that the restoration of C-type Cms has two dominant genes, Rf4 and Rf5. Rf4 has the ability to restore all genotypes of Cms-C lines; however, there exists an inhibitor for the other restorer gene, Rf5; thus, it can restore only those genotypes of Cms-C lines lacking the Rf-I inhibitor.

Cellular neural network analysis for two-dimensional bioheat transfer equation.

The cellular neural network (CNN) method is applied to solve the Pennes bioheat transfer equation, and its feasibility is demonstrated. Numerical solutions were obtained for a cellular neural network for a two-dimensional steady-state temperature field obtained from focused and unfocused ultrasound heat sources. Transient-state temperature fields were also studied and compared with experimental results obtained elsewhere. The cellular neural networks' key features of asynchronous parallel processing, continuous-time dynamics and local interaction enable real-time temperature field estimation for clinical hyperthermia.