Time-intensity curve parameters in colorectal tumours measured using double contrast-enhanced ultrasound: correlations with tumour angiogenesis

AIM

The aim of the study was to assess the correlation between time-intensity curve (TIC) parameters and colorectal tumour angiogenesis using double contrast-enhanced ultrasound (DCEUS), in which an intraluminal contrast agent was used in combination with an intravascular contrast agent.

METHOD

Thirty nine patients with colorectal tumours were examined preoperatively. During hydrocolonal examination with the intraluminal contrast agent, an intravascular contrast agent, SonoVue, was used to perform the DCEUS. The parameter arrival time (AT), time to peak (TTP), peak intensity (PI) and area under the curve (AUC) were measured. Postoperative specimens were assessed for microvessel density (MVD) and vascular endothelial growth factor (VEGF). The correlation between TIC parameters and the expression of VEGF or MVD was studied.

RESULTS

The mean values of AT, TTP, PI and AUC of the colorectal tumours were 14.32 ± 11.36 s, 30.61 ± 18.65 s, 20.38 ± 17.45 dB and 221.10 ± 156.09 dB.s, respectively. Both AUC and MVD were significantly higher in colorectal adenocarcinomas than in adenomas (all P < 0.05). A positive linear correlation was found between the AUC and MVD in colorectal tumours (r = 0.686, P = 0.0019). No correlation was found between VEGF and any TIC parameter.

CONCLUSION

DCEUS is a valuable method for evaluating angiogenesis in colorectal tumours in vivo. The AUC has a positive linear correlation with MVD and could form a new index for assessing angiogenesis and the biological behaviour of colorectal tumours.

Potential risk of zoonotic transmission from young swine to human: seroepidemiological and genetic characterization of hepatitis E virus in human and various animals in Beijing, China

The aim of this study was to further investigate the prevalence of infection and genotype of hepatitis E virus (HEV) among different species of animals, people whose works are related to pigs and the general population in the suburb of Beijing, China. Serum and faecal samples were collected from 10 animal species and humans. Anti-HEV was detected by enzyme immunoassays (EIA); HEV RNA was amplified by reverse transcription-nested polymerase chain reaction (RT-nPCR) method. PCR products were cloned and sequenced. The isolated swine HEV sequences were analysed phylogenetically. The positive rates of serum anti-HEV in swine, cattle, milk cow, horse, sheep, donkey, dog, duck, chicken, pig farm workers and slaughterhouse workers, and general population were 81.17% (802/988), 25.29% (66/261), 14.87% (40/269), 14.29% (40/280), 9.30% (53/514), 0 (0/25), 0 (0/20), 2.53% (8/316), 3.03% (7/231), 58.73% (37/63), 35.87% (66/184) and 20.06% (538/2682), respectively. The anti-HEV prevalence in adult swine (≥ 6 months) and younger swine (≤ 3 months) was 91.49% (591/646) and 61.7% (211/342), respectively. The positive rate of HEV RNA in young swine faeces was 47.94% (93/194). All 93 isolates from the younger swine shared 87.8-100% nucleotide homology with each other and had identities of 75.6-78.9%, 73.9-76.1%, 76.4-80.6% and 83.1-95.0% with the corresponding regions of genotypes 1-4 HEV, respectively. Phylogenetic analysis showed that all HEV isolates belong to genotype 4, subgenotype 4d. These results suggest a potential risk of zoonotic transmission of HEV from younger swine to farmers who rear pigs.

Study on prevalence and genotype of hepatitis E virus isolated from Rex Rabbits in Beijing, China

A novel genotype of hepatitis E virus (HEV) isolated from rabbits is reported. The aim of this study was to confirm and further investigate the prevalence of the novel HEV genotype in rabbits in China. Sera and faecal samples were collected from farmed rex rabbits in Beijing, China. All serum samples were tested for anti-HEV antibody by EIA. Both the serum and the faecal samples were evaluated for detection of HEV RNA using a nested RT-PCR assay. The nucleotide sequences of rabbit HEV were then analysed, and sequence homology of rabbit HEV compared against human HEV genotypes 1-4, and avian HEV.

RESULTS

The prevalence of positive serum anti-HEV from rex rabbits was 54.62% (65/119). The detection rate of HEV RNA using ORF2 primers was 6.96% (8/115) amongst rabbit faecal samples. All eight amplicons shared 98.3-100% nucleotide homology with each other and had identities of 75.8-78.6%, 73.9-75.0%, 77.5-81.0%, 74.2-78.6% and 54.8-57.6% with the corresponding regions of genotypes 1-4 and avian HEV, respectively. Phylogenetic analysis showed that the eight sequences formed one individual branch and were on the same branch with GDC9 and GDC46, both of which were reported to be a novel genotype of HEV isolated from rabbits. The conclusion is that this study provides further information about HEV infecting rabbits, which may be a new animal host of HEV, as well as genetical evidence of a new mammalian genotype of HEV.

Prognosis and role of postmastectomy radiotherapy in patients with T1-T2 breast cancer with one to three positive axillary nodes

PURPOSE

To evaluate the prognosis and role of postmastectomy radiotherapy (PMRT) in T1-T2 breast cancer with one to three positive axillary nodes.

METHODS

The 10-year Kaplan-Meier locoregional recurrence (LRR), distant recurrence (DR), disease-free survival (DFS) and overall survival (OS) were compared between the NO and 1-3N+ cohorts. The role of PMRT was evaluated in the 1-3N+ cohort.

RESULTS

The 10-year LRR, DR, DFS, OS rates in NO and the 1-3N+ cohorts were as follows: LRR 7.5% vs 19.4% (p = 0.011); DR 14.4% vs 23.0% (p = 0.029); DFS 71.3% vs 51.2% (p = 0.001) and OS 77.0% vs 58.7% (p = 0.001). Of the 192 1-3N+ patients not treated and treated with PMRT, the outcomes were: LRR 20.1% vs 18.4% (p = 0.047); DR 26.4% vs 21.5% (p = 0.743); DFS 40.2% vs 55.4% (p = 0.260) and OS 40.7% vs 66.0% (p = 0.344), respectively.

CONCLUSION

PMRT reduces the 10-year LRR rate for such patients, but further examination is needed.

Effect of 3 postmortem electrical stimulation treatments on the quality of early deboned broiler breast meat

The present experiment was carried out to evaluate the effects of electrical stimulation (ES) immediately prescalding (PS), ES immediately postdefeathering (PD), or PS combined with PD (PSPD) on the quality of early deboned (2 h) broiler breast muscles, pectoralis major (fillets), and pectoralis minor (tenders). No stimulation, early-deboned (2 h), and 24-h deboned (24 h) fillets were used for the comparison. The 42-d-old broiler carcasses were electrically stimulated with pulsed current at 200 V for 30 s over a 90-s time interval (total of 1 min over 180 s for PSPD), and breast meat was deboned 2 h postmortem. Quality indicators evaluated were CIE L*, a*, and b* color and pH of the raw fillets and cook yields and Warner-Bratzler (WB) shear force of the fillets and tenders. There were no differences in raw fillet color, pH, and cook yields of both the fillets and tenders between the 3 ES treatments. Effects of different ES treatments on meat WB shear force values varied with breast muscles. For the fillets, the average WB shear force values of both the PS and PSPD samples, which were not different from each other, were significantly lower than those of the PD samples. For the tenders, there were no differences in the average shear force values between the 3 ES treatments. Regardless of ES treatment and breast muscle, early deboned broiler breast meat from ES carcasses required significantly less force to shear than the 2-h control. These results indicate that ES can tenderize early deboned poultry breast muscles; however, the effectiveness of ES tenderization varies with ES treatments for the fillets. The PS treatment is more effective in reducing fillet shear values than PD, and there is no further reduction in shear values with PSPD compared with the PS treatment.

Epidemiology and prevention of hepatitis B virus infection in China

The concept of a hepatitis B vaccine was first introduced into China in 1978. China has been one of the first two developing countries to enact the universal hepatitis B vaccination programme for newborn babies in 1992, and has made tremendous achievements in the control of hepatitis B virus (HBV) infection since then. China now has both low and high endemic regions regarding HBV prevalence co-existing. Although China's drive to stop HBV spread has resulted in changes in HBV epidemic patterns, for the eventual elimination HBV infection in China, it is important to understand the current status of its epidemiology and the aspects of HBV transmission in different regions. More efforts are needed to improve and develop strategies for the control of HBV infection in China, particularly after implementing the policy of universal HBV immunization for all newborns.

Temporal profile of fluorodeoxyglucose uptake in malignant lesions and normal organs over extended time periods in patients with lung carcinoma: implications for its utilization in assessing malignant lesions

AIM

In this study, the fluorodeoxyglucose (FDG) uptake was prospectively investigated in tumors as well as the normal organs over 8 h in patients with non small cell lung carcinoma (NSCLC). The intent of this study was to collect positron emission tomography (PET) data with regard to the time course of FDG uptake in the primary and metastatic sites and the normal tissues over extended time periods (up to 8 h) after intravenous FDG injection in patients.

METHODS

Three patients (2 males, 1 female; mean age: 64 years; age range: 57-76 years) with the diagnosis of NSCLC underwent a series of whole body FDG-PET at several time points, beginning at 5 min and extending up to 8 h after the intravenous administration of FDG. We calculated the standardized uptake values (SUVmax) in the malignant lesions and all organs. SUVmax was calculated over contiguous slices and the highest value was considered for the analysis. Similar locations were used for the placement of regions of interest in subsequent images. Time activity curves (TACs) were generated utilizing these SUV values for each of these sites. The ratios of the SUVmax of the malignant lesions to those of normal organs (viz. lung and liver) at specific time points were also calculated and the TACs for these ratios were generated. The blood and plasma decay curves of (18)F activity over time were generated based on the counts obtained from blood sample analysis. The ratios of 18F activity of blood to plasma were also calculated and the TACs of this ratio were generated.

RESULTS

The observed mean SUVmax at different time points (5 min, 1 h, 2 h, 4 h, 6 h and 8 h) in the organs and the lesions were as follows: 1) heart: 2.9, 2, 1.9, 1.6, 1.3, 1.5; 2) kidney: 3.3, 3.5, 2.6, 2.1, 2, 2; 3) liver: 3.9, 2.2, 1.9, 1.6, 1.5, 1.8; 4) lung: 0.6, 0.5, 0.4, 0.4, 0.4, 0.4, 0.4; 5) large bowel: 2.1, 1.4, 1.8, 1.4, 2, 2.2; 6) small bowel: 2.6, 1.6, 1.4, 1.2, 1.3, 1.5; 7) lung neoplasm: 3.7, 5.1, 6.1, 6.8, 6.9, 6.8; 8) mediastinal lesion 1: 6.8, 8.8, 13, 12.7, 13.8, 12.5; 9) mediastinal lesion 2: 5.5, 8.6, 10.7, 13.2, 11.7, 12.1; 10) adrenal metastasis (starting at 1 h): 3.3, 3.7, 4.7, 4.7, 4.7; 11) right iliac metastasis: 2.6, 2.6, 3.1, 3.5, 3.4. For the right iliac metastasis, we had SUVmax up to 6 h. The SUVmax ratios of malignant lesions to those of normal lung and liver and their TACs demonstrate initial rise followed by a delayed plateau. Increasing (18)F count ratios of blood to plasma with time was observed in 2 patients where these data were available.

CONCLUSIONS

The results from this preliminary study indicate that while the tumor sites show increased uptake of FDG during the course of 8 h, surrounding normal tissues demonstrate declining or stable values with time. This would indicate increasing contrast between the lesion and the background and, therefore, possibly improved sensitivity of the test. While the high SUV at 5 min can be explained by the blood pool activity in the organs and the malignant lesions, the SUVmax values at the later times decreases or remains the same in normal organs. The observation on the different slopes of the curves among the various malignant lesions can be partly explained by the well known ''seed and soil'' theory in cancer biology. The finding of continued increases in the blood to plasma count ratios of (18)F activity is also noteworthy and most likely reflects GLUT-1 mediated glucose transport into red blood cells.

Membership function modification of fuzzy logic controllers with histogram equalization

In most fuzzy logic controllers (FLCs), initial membership functions (MFs) are normally laid evenly all across the universes of discourse (UD) that represent fuzzy control inputs. However, for evenly distributed MFs, there exists a potential problem that may adversely affect the control performance; that is, if the actual inputs are not equally distributed, but instead concentrate within a certain interval that is only part of the entire input area, this will result in two negative effects. On one hand, the MFs staying in the dense-input area will not be sufficient to react precisely to the inputs, because these inputs are too close to each other compared to the MFs in this area. The same fuzzy control output could be triggered for several different inputs. On the other hand, some of the MFs assigned for the sparse-input area are "wasted". In this paper we argue that, if we arrange the placement of these MFs according to a statistical study of feedback errors in a closed-loop system, we can expect a better control performance. To this end, we introduce a new mechanism to modify the evenly distributed MFs with the help of a technique termed histogram equalization. The histogram of the errors is actually the spatial distribution of real-time errors of the control system. To illustrate the proposed MF modification approach, a computer simulation of a simple system that has a known mathematical model is first analyzed, leading to our understanding of how this histogram-based modification mechanism functions. We then apply this method to an experimental laser tracking system to demonstrate that in real-world applications, a better control performance can he obtained by using this proposed technique.

Microtia: ear reconstruction using tissue expander and autogenous costal cartilage

Ear reconstruction is one of the most challenging surgeries faced by the reconstructive surgeon. Currently, the use of autogenous costal cartilage is still best practice for microtia reconstruction. However, the relative deficiency of thin skin for coverage of the cartilage framework remains a limiting factor. Since 1994, we have used tissue expander in the mastoid area and innovated a technique to fabricate cartilage framework. All these innovations may solve the deficiency of the skin and improve cartilaginous framework definition. In conclusion, tissue expander offers a non-hairbearing, thin, well-vascularised skin to envelope an erect, contour-accentuated framework. Most patients with microtia are satisfied with their ear reconstruction.

Heme oxygenase-1 protects brain from acute excitotoxicity

Heme oxygenase is a rate-limiting enzyme that degrades heme, a pro-oxidant, into carbon monoxide, iron, and bilirubin. Heme oxygenase has two active isoforms: heme oxygenase-1 and heme oxygenase-2. Heme oxygenase-1 can be induced by various insults. Several investigators have postulated that it has cytoprotective activities, although its role in the nervous system is not fully understood, especially considering that normally heme oxygenase-2 accounts for the vast majority of heme oxygenase activity in the brain. Here, the basal effect of heme oxygenase-1 was investigated in acute glutamatergic excitotoxicity to test the hypothesis that N-methyl-D-aspartate-induced acute toxicity in brain is attenuated by heme oxygenase-1. N-methyl-D-aspartate was unilaterally injected into the striatum of wildtype and heme oxygenase-1 knockout mice. After 48 h, brains were harvested, sectioned, and stained with Cresyl Violet to measure the lesion size. Lesion volume was significantly (P<0.05) greater in brains of heme oxygenase-1 knockout mice (15.2+/-3.1 mm(3); n=10) than in those of wildtype mice (6.2+/-1.5 mm(3); n=11). In addition, Western blot analysis indicated no detectable differences between wildtype and heme oxygenase-1 knockout mouse brains in the levels of the glutamate or N-methyl-D-aspartate receptors studied. To test whether heme oxygenase-1 could specifically protect neurons, mouse primary neuronal cell cultures of wildtype and heme oxygenase-1 knockout mice were treated with or without N-methyl-D-aspartate. Cell viability of the heme oxygenase-1 knockout neurons was significantly less than that of wildtype neurons at each of the N-methyl-D-aspartate concentrations tested (12.8+/-1.3%, 16.0+/-1.4%, and 18.4+/-1.8% at 30, 100, and 300 microM N-methyl-D-aspartate, respectively). These results indicate that heme oxygenase-1 provides neuroprotection against acute excitotoxicity and suggest that potential intervention that can increase heme oxygenase-1 activity within the brain should be considered as a therapeutic target in acute and potentially chronic neurological disorders.

Detection of mutA genes in transmitted strains and nontransmitted strains of mutans streptococci

Our aim was to determine whether an isolate carrying one of the mutA genes was related to its ability to be transmitted from mother to her child. First, 200 mutans streptococci isolates were genotyped by arbitrarily primed polymerase chain reaction (AP-PCR) to demonstrate transmission between 20 mother-child pairs and to detect the transmitted and nontransmitted strains. Then the mutacin structural genes mutA encoding mutacin types I, II, and III were screened by PCR. The results showed that all strains found to carry the mutAI gene were nontransmitted strains; PCR screening primers mutAII and mutAIII did not yield amplicons in any of the strains tested. Our data suggest that an isolate carrying the mutAI gene is related to reduced transmission. The low frequency of detection of mutAII, and mutAIII suggests that there is a high heterogeneity in the genetic determinants needed for the production of mutacin-like substances.