A comparative study of the normal oesophageal wall thickness based on 3-dimensional, 4-dimensional, and cone beam computed tomography.

BACKGROUND: The study aimed to compare normal oesophageal wall thickness based on 3-dimensional computed tomography (3DCT), 4-dimensional computed tomography (4DCT) and cone beam computed tomography (CBCT). METHODS: Contrast-enhanced 3DCT, 4DCT, and CBCT scans were acquired from 50 patients with lung cancer or metastatic lung cancer. The outer oesophageal wall was manually contoured on each 3DCT, the maximum intensity projection of 4DCT (4DCTMIP) the end expiration phase of 4DCT (4DCT50) (the end expiration phase of 4DCT) and the CBCT data sets. The average wall thicknesses were measured (defined as R3DCT, R50, RMIP, and RCBCT). RESULTS: Whether for thoracic or for intra-abdominal segments, there were no significant differences between R3DCT and R50, but significant differences between R3DCT and RMIP, R3DCT and RCBCT. For upper and middle oesophagus, RCBCT were larger than RMIP. There was no significant difference between upper and middle segments on 3DCT, 4DCT, and CBCT. Intra-abdominal oesophageal wall thickness was greater than that of thoracic oesophagus. There were no differences between upper and lower, and middle and lower oesophagus on CBCT. CONCLUSION: Our findings indicate normal oesophageal wall thickness differed along the length of oesophagus whatever it was delineated on 3DCT, 4DCT (4DCT50 and 4DCTMIP) or CBCT. It is reasonable to use uniform criterion to identify normal esophageal wall thickness when delineating gross tumor volume on 3DCT and 4DCT50, the same is true of delineating internal gross tumor volume on 4DCTMIP or CBCT images for lower and intra-abdominal oesophagus. But, in spite of using contrast-enhanced scanning, relatively blurred boundary on the CBCT images is noteworthy, especially for upper and middle thoracic esophagus.

Comparison of gross tumor volume of primary oesophageal cancer based on contrast-enhanced three-dimensional, four-dimensional, and cone beam computed tomography.

BACKGROUND: To explore motion information included in 3DCT, 4DCT and CBCT by comparing volumetric and positional differences of GTV. RESULTS: Independent of tumor location, significant differences were observed among volumes [IGTV10 > (IGTVCBCT or IGTVMIP) > (GTV3D or GTV4D50)]. The underestimations or overestimations between IGTV10 and IGTVCBCT were larger than those between IGTV10 and IGTVMIP (p < 0.001-0.011; p < 0.001-0.023). For upper oesophageal tumors, GTV4D50/IGTVCBCT negatively correlated with motion vector (r = -0.756, p = 0.011). In AP direction, the centroid coordinates of IGTVCBCT differed from GTV3D, GTV4D50, IGTVMIP and IGTV10 (p = 0.006, 0.013, 0.038, and 0.010). For middle oesophageal tumors, IGTV10/IGTVCBCT positively correlated with motion vector (r = 0.695, p = 0.006). The centroid coordinates of IGTVCBCT differed from those of IGTV10 (p = 0.046) in AP direction. For distal oesophageal tumors, the centroid coordinates of IGTVCBCT showed significant differences to those of IGTVMIP (p = 0.042) in LR direction. For both middle and distal tumors, the degrees of associations of IGTV10 outside IGTVCBCT significantly correlated with the motion vector (r = 0.540, p = 0.046; r = 0.678, p = 0.031). MATERIALS AND METHODS: Thirty-four oesophageal cancer patients underwent 3DCT, 4DCT and CBCT. GTV3D, GTV4D50, internal GTVMIP (IGTVMIP) and IGTVCBCT were delineated on 3DCT, 4DCT50, 4DCTMIP and CBCT. GTVs from 10 respiratory phases were combined to produce GTV10. Differences in volume, position for different targets, correlation between volume ratio and motion vector were evaluated. The motion vector was the spatial moving of the target centroid position. CONCLUSIONS: IGTVCBCT encompasses more motion information than GTV3D and GTV4D50 for upper oesophageal tumors, but slightly less than IGTV10 for middle and distal oesophageal tumors. IGTVCBCT incorporated similar motion information to IGTVMIP. However, motion information encompassed in CBCT and MIP cannot replace each other.

Interactions of Methylenetetrahydrofolate Reductase Gene Polymorphisms, Folate, and Homocysteine on Blood Pressure in a Chinese Hypertensive Population.

BACKGROUND: High blood pressure is related to cardiovascular diseases. We aimed to explore the interactions of methylenetetrahydrofolate reductase (MTHTR) gene C677T and A1298C mutations and folate/homocysteine (Hcy) status on blood pressure in a Chinese hypertensive population. METHODS: The clinical data in the present study derived from a previous trial (NCT00520247). Genotypes in Hcy pathway enzymes were detected by PCR-RFLP methods. Supine blood pressure was measured with a mercury sphygmomanometer. Serum Hcy was measured by high-performance liquid chromatography, and serum folate was measured by chemiluminescent immunoassay. RESULTS: This study showed that hyperhomocysteinemia independently elevated diastolic blood pressure (DBP) (ß (SE): 2.02 (0.85), p = 0.018). Furthermore, individuals with high Hcy and MTHFR1298AC + CC genotypes showed higher DBP than the normal Hcy and 1298AA carriers (ß (SE): 1.81 (0.54), p = 0.001). This correlation was verified by the trend test (p = 0.003). However, polymorphisms of MTHFR C677T, MTR A2756G or MTRR A66G do not affect baseline blood pressure level. CONCLUSIONS: The present study demonstrated that the MTHFR A1298C mutation accompanied by hyperhomocysteinemia jointly elevated DBP. Further studies are necessary to confirm the role of these genotypes and Hcy on blood pressure in a larger population.

Analysis on genetic diversification and heterosis in autotetraploid rice.

Polyploidization has played an important role in plant evolution and is a pathway for plants to increase genetic diversification and to get higher heterosis comparing with that of diploid does. This study was undertaken to assess the genetic variation and relationships among 40 autotetraploid rice genotypes and their counterpart diploid cultivars with 99 SSR markers screened from published rice genome. The 99 SSR markers detected polymorphism among autotetraploid genotypes and revealed a total of 291 alleles with an average of 2.949 alleles per locus. Autotetraploid lines showed higher genetic diversity and significant variation in agronomic traits than diploid cultivars. Phylogenetic analysis revealed that most of autotetraploid lines were genetically different from their diploid parents, and inter-subspecific hybrids were prepared on the basis of genetic distance between parents. Inter-subspecific autotetraploid hybrids showed a higher and positive heterobeltiosis and competitive heterosis than diploid hybrids, especially for grain yield. Genetic distance appeared not to predict heterosis in diploid rice for all traits; however, it showed a significant correlation with grain yield, grain length and grain length to width ratio in autotetraploid rice. This extensive research on autotetraploid heterosis and genetic diversity will be useful for the development of autotetraploid rice hybrids.

Abnormalities occurring during female gametophyte development result in the diversity of abnormal embryo sacs and leads to abnormal fertilization in indica/japonica hybrids in rice.

Embryo sac abortion is one of the major reasons for sterility in indica/japonica hybrids in rice. To clarify the causal mechanism of embryo sac abortion, we studied the female gametophyte development in two indica/japonica hybrids via an eosin B staining procedure for embryo sac scanning using confocal laser scanning microscope. Different types of abnormalities occurred during megasporogenesis and megagametogenesis were demonstrated. The earliest abnormality was observed in the megasporocyte. A lot of the chalazal-most megaspores were degenerated before the mono-nucleate embryo sac stage. Disordered positioning of nucleus and abnormal nucellus tissue were characteristics of the abnormal female gametes from the mono-nucleate to four-nucleate embryo sac stages. The abnormalities that occurred from the early stage of the eight-nucleate embryo sac development to the mature embryo sac stage were characterized by smaller sizes and wrinkled antipodals. Asynchronous nuclear migration, abnormal positioning of nucleus, and degeneration of egg apparatus were also found at the eight-nucleate embryo sac stage. The abnormalities that occurred during female gametophyte development resulted in five major types of abnormal embryo sacs. These abnormal embryo sacs led to abnormal fertilization. Hand pollination using normal pollens on the spikelets during anthesis showed that normal pollens could not exclude the effect of abnormal embryo sac on seed setting.