Theoretical and experimental investigations on rotary ultrasonic surface micro-machining of brittle materials

Many brittle materials, such as single-crystal materials, amorphous materials, and ceramics, are widely used in many industries such as the energy industry, aerospace industry, and biomedical industry. In recent years, there is an increasing demand for high-precision micro-machining of these brittle materials to produce precision functional parts. Traditional ultra-precision micro-machining can lead to workpiece cracking, low machined surface quality, and reduced tool life. To reduce and further solve these problems, a new micro-machining process is needed. As one of the nontraditional machining processes, rotary ultrasonic machining is an effective method to reduce the issues generated by traditional machining processes of brittle materials. Therefore, rotary ultrasonic micro-machining (RUμM) is investigated to conduct the surface micro-machining of brittle materials. Due to the small diameter cutting tool (<500 μm) and high accuracy requirements, the impact of input parameters in the rotary ultrasonic surface micro-machining (RUSμM) process on tool deformation and cutting quality is extremely different from that in rotary ultrasonic surface machining (RUSM) with relatively large diameter cutting tool (∼10 mm). Up till now, there is still no investigation on the effects of ultrasonic vibration (UV) and input variables (such as tool rotation speed and depth of cut) on cutting force and machined surface quality in RUSμM of brittle materials. To fill this knowledge gap, rotary ultrasonic surface micro-machining of the silicon wafer (one of the most versatile brittle materials) was conducted in this study. The effects of ultrasonic vibration, tool rotation speed, and depth of cut on tool trajectory, material removal rate (MRR), cutting force, cutting surface quality, and residual stress were investigated. Results show that the ultrasonic vibration could reduce the cutting force, improve the cutting surface quality, and suppress the residual compressive stress, especially under conditions with high tool rotation speed.

Multilayer 3D Chiral Folding Polymers and Their Asymmetric Catalytic Assembly

A novel class of polymers and oligomers of chiral folding chirality has been designed and synthesized, showing structurally compacted triple-column/multiple-layer frameworks. Both uniformed and differentiated aromatic chromophoric units were successfully constructed between naphthyl piers of this framework. Screening monomers, catalysts, and catalytic systems led to the success of asymmetric catalytic Suzuki-Miyaura polycouplings. Enantio- and diastereochemistry were unambiguously determined by X-ray structural analysis and concurrently by comparison with a similar asymmetric induction by the same catalyst in the asymmetric synthesis of a chiral three-layered product. The resulting chiral polymers exhibit intense fluorescence activity in a solid form and solution under specific wavelength irradiation.

Asymmetric Catalytic Assembly of Triple-Columned and Multilayered Chiral Folding Polymers Showing Aggregation-Induced Emission (AIE)

Invited for the cover of this issue are Guigen Li's groups at Texas Tech University and Nanjing University. The cover artwork shows that chirality patterns exist from universal to molecular levels showing light emission properties. Read the full story of multilayer 3D chirality and its asymmetric catalytic synthesis at 10.1002/chem.202104102.

A randomised phase II trial of hydroxychloroquine and imatinib versus imatinib alone for patients with chronic myeloid leukaemia in major cytogenetic response with residual disease

In chronic-phase chronic myeloid leukaemia (CP-CML), residual BCR-ABL1+ leukaemia stem cells are responsible for disease persistence despite TKI. Based on in vitro data, CHOICES (CHlorOquine and Imatinib Combination to Eliminate Stem cells) was an international, randomised phase II trial designed to study the safety and efficacy of imatinib (IM) and hydroxychloroquine (HCQ) compared with IM alone in CP-CML patients in major cytogenetic remission with residual disease detectable by qPCR. Sixty-two patients were randomly assigned to either arm. Treatment 'successes' was the primary end point, defined as ≥0.5 log reduction in 12-month qPCR level from trial entry. Selected secondary study end points were 24-month treatment 'successes', molecular response and progression at 12 and 24 months, comparison of IM levels, and achievement of blood HCQ levels >2000 ng/ml. At 12 months, there was no difference in 'success' rate (p = 0.58); MMR was achieved in 80% (IM) vs 92% (IM/HCQ) (p = 0.21). At 24 months, the 'success' rate was 20.8% higher with IM/HCQ (p = 0.059). No patients progressed. Seventeen serious adverse events, including four serious adverse reactions, were reported; diarrhoea occurred more frequently with combination. IM/HCQ is tolerable in CP-CML, with modest improvement in qPCR levels at 12 and 24 months, suggesting autophagy inhibition maybe of clinical value in CP-CML.

Ultrasensitive Wearable Strain Sensors of 3D Printing Tough and Conductive Hydrogels

In this study, tough and conductive hydrogels were printed by 3D printing method. The combination of thermo-responsive agar and ionic-responsive alginate can highly improve the shape fidelity. With addition of agar, ink viscosity was enhanced, further improving its rheological characteristics for a precise printing. After printing, the printed construct was cured via free radical polymerization, and alginate was crosslinked by calcium ions. Most importantly, with calcium crosslinking of alginate, mechanical properties of 3D printed hydrogels are greatly improved. Furthermore, these 3D printed hydrogels can serve as ionic conductors, because hydrogels contain large amounts of water that dissolve excess calcium ions. A wearable resistive strain sensor that can quickly and precisely detect human motions like finger bending was fabricated by a 3D printed hydrogel film. These results demonstrate that the conductive, transparent, and stretchable hydrogels are promising candidates as soft wearable electronics for healthcare, robotics and entertainment.

Scratching-induced surface characteristics and material removal mechanisms in rotary ultrasonic surface machining of CFRP

Rotary ultrasonic machining has been successfully explored in surface machining of carbon fiber reinforced plastic (CFRP) composites. It has been proven to be an effective and efficient CFRP machining method. Both theoretical and experimental investigations have been conducted with the assumption that the CFRP is removed by brittle fracture removal mode. However, in brittle material machining, ductile flow phenomenon still exists. Ductile scratching marks are also observed on the machined CFRP surfaces. It is still unknown that what actual material removal modes are under different machining variables. To investigate the material removal mechanisms in rotary ultrasonic surface machining (RUSM) of CFRP, single abrasive scratching tests were conducted. The scratching induced characteristics and scratching forces were analyzed. Both the ductile removal mode and the brittle fracture removal mode were observed and identified in both carbon fiber layers and epoxy resin layers on the machined marks by using scanning electron microscopy (SEM) imaging. With the increase of scratching depth, the material removal mode of CFRP was changed from the ductile removal mode to the brittle fracture mode. From the analysis of kinematic trajectory of diamond grain, the scratching cutting forces were decreased in the tests with the assistance of ultrasonic vibration under the same machining variables. The generation mechanisms of the delamination were analyzed and discussed.

Polyphenols and health: Interactions between fibre, plant polyphenols and the gut microbiota

A high‐fibre diet and one rich in fruit and vegetables have long been associated with lower risk of chronic disease. There are several possible mechanisms underpinning these associations, but one likely important factor is the production of bioactive molecules from plant‐based foods by the bacteria in the colon. This links to our growing understanding of the role of the gut microbiome in promoting health. Polyphenolic‐rich plant foods have been associated with potential health effects in many studies, but the bioavailability of polyphenol compounds, as eaten, is often very low. Most of the ingested molecules enter the large intestine where they are catabolised to smaller phenolic acids that may be the key bioactive effectors. Dietary fibres, present in plant foods, are also fermented by the bacteria to short‐chain fatty acids, compounds associated with several beneficial effects on cell turnover, metabolism and eating behaviour. Polyphenols and fibre are often eaten together, but there is a lack of research investigating the interaction between these two groups of key substrates for the colonic bacteria. In a project funded by the Biotechnology and Biological Sciences Research Council Diet and Health Research Industry Club, we are investigating whether combining different fibres and polyphenol sources can enhance the production of bioactive phenolic acids to promote health. This could lead to improved dietary recommendations and to new products with enhanced potential health‐promoting actions.

A mechanistic ultrasonic vibration amplitude model during rotary ultrasonic machining of CFRP composites

Rotary ultrasonic machining (RUM) has been investigated in machining of brittle, ductile, as well as composite materials. Ultrasonic vibration amplitude, as one of the most important input variables, affects almost all the output variables in RUM. Numerous investigations on measuring ultrasonic vibration amplitude without RUM machining have been reported. In recent years, ultrasonic vibration amplitude measurement with RUM of ductile materials has been investigated. It is found that the ultrasonic vibration amplitude with RUM was different from that without RUM under the same input variables. RUM is primarily used in machining of brittle materials through brittle fracture removal. With this reason, the method for measuring ultrasonic vibration amplitude in RUM of ductile materials is not feasible for measuring that in RUM of brittle materials. However, there are no reported methods for measuring ultrasonic vibration amplitude in RUM of brittle materials. In this study, ultrasonic vibration amplitude in RUM of brittle materials is investigated by establishing a mechanistic amplitude model through cutting force. Pilot experiments are conducted to validate the calculation model. The results show that there are no significant differences between amplitude values calculated by model and those obtained from experimental investigations. The model can provide a relationship between ultrasonic vibration amplitude and input variables, which is a foundation for building models to predict other output variables in RUM.

Laser Engineered Net Shaping of Nickel-Based Superalloy Inconel 718 Powders onto AISI 4140 Alloy Steel Substrates: Interface Bond and Fracture Failure Mechanism

As a prospective candidate material for surface coating and repair applications, nickel-based superalloy Inconel 718 (IN718) was deposited on American Iron and Steel Institute (AISI) 4140 alloy steel substrate by laser engineered net shaping (LENS) to investigate the compatibility between two dissimilar materials with a focus on interface bonding and fracture behavior of the hybrid specimens. The results show that the interface between the two dissimilar materials exhibits good metallurgical bonding. Through the tensile test, all the fractures occurred in the as-deposited IN718 section rather than the interface or the substrate, implying that the as-deposited interlayer bond strength is weaker than the interfacial bond strength. From the fractography using scanning electron microscopy (SEM) and energy disperse X-ray spectrometry (EDS), three major factors affecting the tensile fracture failure of the as-deposited part are (i) metallurgical defects such as incompletely melted powder particles, lack-of-fusion porosity, and micropores; (ii) elemental segregation and Laves phase, and (iii) oxide formation. The fracture failure mechanism is a combination of all these factors which are detrimental to the mechanical properties and structural integrity by causing premature fracture failure of the as-deposited IN718.

Superiorization-based multi-energy CT image reconstruction

The recently-developed superiorization approach is efficient and robust for solving various constrained optimization problems. This methodology can be applied to multi-energy CT image reconstruction with the regularization in terms of the prior rank, intensity and sparsity model (PRISM). In this paper, we propose a superiorized version of the simultaneous algebraic reconstruction technique (SART) based on the PRISM model. Then, we compare the proposed superiorized algorithm with the Split-Bregman algorithm in numerical experiments. The results show that both the Superiorized-SART and the Split-Bregman algorithms generate good results with weak noise and reduced artefacts.

Metal ion type significantly affects the morphology but not the activity of lipase–metal–phosphate nanoflowers

Using different metal ions to prepare hybrid lipase nanoflowers resulted in a variety of different morphologies, but did not significantly affect the specific activity of the enzyme.

3D printing of an extremely tough hydrogel

A super tough hydrogel with tunable mechanical properties was 3D printed.

Chlamydia psittaci exposure in pet birds

Chlamydia psittaci is a zoonotic pathogen with a wide range of avian hosts and may be transmitted to humans and cause severe disease. To assess the risk of psittacosis posed by pet birds, the seroprevalence of Chlamydia psittaci antibodies in 360 Eurasian siskins (Carduelis spinus), 289 oriental skylarks (Alauda arvensis) and 36 black-tailed grosbeaks (Coccothraustes migratorius) in Gansu province, north-western China was detected by an indirect haemagglutination assay. Twenty-seven out of 289 (9.34 %) Alauda arvensis, 45 out of 360 (12.50 %) Carduelis spinus and 2 out of 36 (5.56 %) Coccothraustes migratorius were positive for Chlamydia psittaci infection at a cut-off dilution of 1 : 16. The prevalence of Chlamydia psittaci was higher in Carduelis spinus (12.5 %) than in Alauda arvensis (9.34 %) and Coccothraustes migratorius (5.56 %); however, the differences were not statistically significant (P>0.05). Statistical analysis indicated that Chlamydia psittaci seroprevalence in adult pet birds (12.4 %, 67/540) was significantly higher than that in juvenile pet birds (4.83 %, 7/145) (P<0.01). There was no statistical difference in Chlamydia psittaci seroprevalence between male (12.4 %) and female (8.27 %) birds. To our knowledge, this is the first report indicating the seroprevalence of Chlamydia psittaci exposure in pet birds in China. Our results indicate that close contact with pet birds poses the risk of zoonotic transmission of Chlamydia psittaci.

Seroprevalence of Chlamydia psittaci infection in market-sold adult chickens, ducks and pigeons in north-western China

Chlamydia psittaci, the agent of psittacosis in humans, infects a wide range of avian species. To assess the risk of psittacosis posed by domestic birds in the urban environment, the prevalence of C. psittaci antibodies in 413 chickens (Gallus domesticus; 305 caged and 108 free-range), 334 ducks (Anas spp.; 111 caged and 223 free-range) and 312 pigeons (Columba livia) in Lanzhou, north-western China, was detected using the indirect haemagglutination assay. The specific antibodies were found in sera of 55 (13.32 %) chickens, 130 (38.92 %) ducks and 97 (31.09 %) pigeons. Statistical analysis showed that the seroprevalence of C. psittaci infection in chickens was significantly lower than that in ducks and pigeons (P<0.05). The C. psittaci seroprevalence in caged and free-range chickens was 7.54 % and 29.63 %, respectively, and the difference was statistically significant (P<0.05). The C. psittaci seroprevalence in caged and free-range ducks was 26.13 % and 45.29 %, respectively (P<0.05). To our knowledge, this is the first study indicating the presence of C. psittaci infection in market-sold chickens, ducks and pigeons in north-western China. Close contact with these birds is associated with a risk of zoonotic transmission of C. psittaci. Public education should be implemented to reduce the risk of avian to human transmission of such a pathogenic agent.

X-ray dark-field imaging modeling

Dark-field images are formed from x-ray small-angle scattering signals. The small-angle scattering signals are particularly sensitive to structural variation and density fluctuation on a length scale of several tens to hundreds of nanometers, offering a unique contrast mechanism to reveal subtle structural features of an object. In this study, based on the principle of energy conservation, we develop a physical model to describe the relationship between x-ray small-angle scattering coefficients of an object and dark-field intensity images. This model can be used to reconstruct volumetric x-ray small-angle scattering images of an object using classical tomographic algorithms. We also establish a relationship between the small-angle scattering intensity and the visibility function measured with x-ray grating imaging. The numerical simulations and phantom experiments have demonstrated the accuracy and practicability of the proposed model.

X-ray scattering tomography for biological applications

The conventional attenuation contrast imaging does not yield satisfactory sensitivity and specificity for weakly absorbing media, such as biological soft tissues. The x-ray scattering offer an important contrast mechanism to reveal structural features and density fluctuation within an object. This scattering signal carries information at the molecular and supra-molecular level, and has a tremendous implication for biomedical and other applications. In this paper, we develop a scattering imaging approach to reconstruct the electron density distribution of an object and demonstrate its feasibility in the numerical simulation.

Rotary Ultrasonic Machining of Dental Ceramics: A Preliminary Study on Subsurface Cracks

Commercially available dental computer aided design/computer aided manufacture (CAD/CAM) systems usually use abrasive machining processes such as diamond grinding and milling. One of the major disadvantages of abrasive machining processes is subsurface cracks. In the present paper, rotary ultrasonic machining (RUM) technology is introduced into machining of alumina dental ceramics. The subsurface cracks are observed under scanning electron microscope. Effects of ultrasonic vibration on the subsurface cracks are also investigated. Results show that RUM is a very promising process to significantly reduce subsurface cracks in CAD/CAM of dental ceramics.

Bioluminescence tomography based on the phase approximation model

A reconstruction method of bioluminescence sources is proposed based on a phase approximation model. Compared with the diffuse approximation, this phase approximation model more correctly predicts bioluminescence photon propagation in biological tissues, so that bioluminescence tomography can accurately locate and quantify the distribution of bioluminescence sources. The compressive sensing (CS) technique is applied to regularize the inverse source reconstruction to enhance numerical stability and efficiency. The numerical simulation and phantom experiments demonstrate the feasibility of the proposed approach.

OPTICAL PROPERTY CHARACTERIZATION BASED ON A PHASE FUNCTION APPROXIMATION MODEL

Recently, we generalized the Delta-Eddington phase function and applied it to the radiative transfer equation for modeling the photon propagation in biological tissue. The resultant phase approximation model was shown to be highly accurate with a wide range of optical properties, including the strongly absorbing and weakly scattering media. In this paper, we propose phase-approximation-based method for estimating the optical parameters. Specifically, we design an iterative algorithm to take advantage of both the global search ability of the differential evolution algorithm and the efficiency of the conjugate gradient method. Then, we demonstrate the feasibility and merits of the proposed method in both numerical simulation and phantom experiments.

Modeling photon propagation in biological tissues using a generalized Delta-Eddington phase function

Photon propagation in biological tissue is commonly described by the radiative transfer equation, while the phase function in the equation represents the scattering characteristics of the medium and has significant influence on the precision of solution and the efficiency of computation. In this work, we present a generalized Delta-Eddington phase function to simplify the radiative transfer equation to an integral equation with respect to photon fluence rate. Comparing to the popular diffusion approximation model, the solution of the integral equation is highly accurate to model photon propagation in the biological tissue over a broad range of optical parameters. This methodology is validated by Monte Carlo simulation.

Flux vector formulation for photon propagation in the biological tissue

We present a generalized delta-Eddington phase function to simplify the radiative transfer equation to an integral equation with respect to the photon flux vector. The solution of the integral equation is highly accurate to model the photon propagation in the biological tissue over a broad range of optical parameters, especially in the visible light spectrum where the diffusion approximation breaks down. The methodology is validated in the Monte Carlo simulation and can be applied in various optical imaging applications.

Regulation of CO on heterocyst differentiation and nitrate uptake in the cyanobacterium Anabaena sp. PCC 7120

AIMS

The aim of the present investigation was to study the effects of different inorganic carbon and nitrogen sources on nitrate uptake and heterocyst differentiation in the culture of cyanobacterium Anabaena sp. PCC 7120.

METHODS AND RESULTS

Anabaena was cultivated in media BG11 containing combined nitrogen and supplementary NaHCO3 or CO2. Cell growth, heterocyst differentiation, nitrate reductase (NR, EC 1.7.7.2), glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) and NO uptake were analysed. The cells cultivated in BG11(0) medium with aeration were taken as reference. Experimental results showed that the differentiation frequency of heterocysts when the cells were cultivated with elevated CO2 was higher than that of the cells grown with air or bicarbonate. Heterocysts appeared unexpectedly when CO2 was introduced into the medium containing nitrate. However, no heterocysts emerged when CO2 was added to medium containing NH or urea, or when NaHCO3 was supplied to the medium with nitrate. Both nitrate uptake rate and nitrate reduction enzyme activity were depressed by the supplement of CO2 to the culture. The activity of G6PDH was enhanced with the increase in heterocyst differentiation frequency.

CONCLUSION

CO2 might compete with NO for energy and electrons in the uptake process and CO2 appears favoured. This led to a high intracellular C/N ratio and a relative N limitation. So the process of heterocyst differentiation was activated to supplement nitrogen uptake.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided an attractive possibility to form more heterocysts by rapid growth of Anabaena cells cultivated in the medium containing nitrate in order to increase nitrogen fixation and hydrogen production.

[Quantitative analysis of the expression of insulin receptor and tyrosine protein kinase of patients with hepatic cirrhosis]

OBJECTIVE

To investigate the relationship between the expression of insulin receptor (IR) and the content of tyrosine protein kinase (TPK) in patients with hepatic cirrhosis.

METHODS

Glucose tolerance test (GTT), insulin, c-peptide, insulin antibodies in serum, the expression of IR and TPK were quantitively analysed in patients with hepatic cirrhosis. The amount of IR and TPK was evaluated by immunohistochemical quantitative analysis using image analyzer in 12 patients with positive HBV marks and cirrhosis. Insulin and c-peptide in serum were determined by immunoenzymemetric assay (IEMA) and insulin antibodies in serum determined by RIA.

RESULTS

IR amount in normal and abnormal GTT patients with hepatic cirrhosis was signifficantly less than that in control group (P<0.01). TPK amount in liver of patitents with abnormal GTT was less than that of normal GTT (P<0.01).

CONCLUSIONS

IR decreases in cirrhotic patients. Abnormal GTT has relation to reducing TPK activity.

Allelic loss and gain, but not genomic instability, as the major somatic mutation in primary hepatocellular carcinoma

To identify genetic abnormalities in primary hepatocellular carcinoma (HCC), we performed microsatellite analysis (MSA) on 60 Chinese HCC specimens. Utilizing a semi-quantitative MSA and 292 highly polymorphic markers spanning all 22 autosomes, we found that somatic allelic imbalance (AI) occurred frequently in HCC. To evaluate the nature of the AI, comparative genomic hybridization was performed on 20 HCC specimens. The combined use of these two methods revealed frequent allelic loss on 17p, 9p21-p23, 4q, 16q21-q23.3, 13q, 8p21-p23, and 6q24-q27, whereas there was frequent allelic gain on 1q, 17q, and 8q24. The region with the highest incidence of genomic imbalance was 17p13 (65%), followed by 9p21-p23 (55%), 4q (35-51%), 16q21-q23.3 (52%), 17p12 (49%), 13q (39-46%), 8p21-p23 (41-45%), 8q24 (41%), and 1q32 (40%). In addition, aberrations of 19p13.3, 16p13.3, 13q33-q34, 9q13-31, and 7q were reported for the first time. The presence of a close correlation of 17p13 deletion with abnormalities of some other loci implies that 17p13 could play a crucial role in oncogenesis. Interestingly, microsatellite instability was rarely seen in our patients, in contrast to that observed in European HCC samples.

[Relationship between genetic alterations and clinicopathological features in intrahepatic cholangiocarcinoma]

OBJECTIVE

To evaluate the pedigree of genetic alterations during the tumorigenesis of intrahepatic cholangiocarcinoma (ICC) and their correlation with clinicopathological features by analysis of loss of heterozygosity (LOH) in 6 tumor suppressor genes (APC, MCC, DCC, OGG1, p53 and RB1) and point mutations in Ki-ras-2 oncogene.

METHODS

Genomic DNA was isolated from paraffin-embedded slides of 22 surgically resected ICC cases by microdissection-based PCR amplification and agarose gel electrophoresis. Genetic alterations were analyzed by direct DNA sequencing.

RESULTS

The total frequency of alterations in 7 genes studied was 86.4% (19/22). Based on the pattern of altered genes and their correlation with clinicopathological parameters, the genetic alterations were classified into two groups: Group I (9/19, 47.4%): alterations in APC, MCC, DCC and Ki-ras-2,); Group II (10/19, 52.6%): alterations in p53, OGG1 and RB1. The average age of patients in Group I (mean age, 57.2 years) was significantly younger than those in Group II (mean age, 69.1 years) (P < 0.05).

CONCLUSIONS

The occurrence and development of ICC was closely related with the accumulation and cooperation of multiple genetic alterations. The genetic alterations of APC, MCC, DCC and Ki-ras-2 may play crucial roles in the early stage of development of ICC, and the genetic alterations of p53, OGG1 and RB1 may play important roles in accelerating advanced progression of ICC. The detection of the pedigree of genetic alterations in ICC may provide useful information for evaluating the state of tumor progression and clinic prognosis.

[Genotyping of multiple genetic alterations of intrahepatic cholangiocarcinoma]

OBJECTIVE

To provide genetic evidence for understanding the mechanism of oncogenesis of intrahepatic cholangiocarcinoma (ICC) by detecting the multiple genetic spectrums.

METHODS

Twenty-two cases of paraffin-embedded ICC tissue sections were microdissected and genotyped by PCR-based DNA sequencing to detect the frequencies of loss of heterozygosity (LOH) of tumor suppressor genes APC, MCC, DCC, OGG1, p53, and RB1 and of point mutation of Ki-ras-2 oncogene.

RESULTS

The genetic alteration rate was 68.8% for APC, 46.2% for DCC, 41.7% for OGG1, 37.5% for p53, 27.3% for Ki-ras-2, 22.2% for RB1, and 14.3% for MCC.

CONCLUSION

ICC-related genetic spectrum is basically composed of APC, DCC, OGG1, p53, and Ki-ras-2. Multiple genetic alteration plays an important role in the carcinogenesis of ICC.

[E-selectin and its ligand-sLeX in the metastasis of hepatocellular carcinoma]

OBJECTIVE

To study the significance of E-selectin and its ligand-sLeX in the metastasis of hepatocellular carcinoma (HCC).

METHODS

Flow cytometry and immunohistochemistry were used to detect the expression of E-selectin and its ligand-sLeX in HCC cell lines and in human HCC tissues.

RESULTS

The positive rate of E-selectin in vascular endothelial cells adjacent to cancer nest in tumors was 67.9% (19/28). In tumors accompanied with emboli or satellite foci, it was significantly higher than that without emboli or satellite foci (P < 0.05). The positive rate of E-selectin was not related to tumor size, tumor capsule, AFP, and the degree of differentiation. The positive expressions of sLeX in SMMU-7721, PLC/PRF/5 and HepGII cell lines were 7.03%, 63.35% and 97.29% respectively. The positive cells of sLeX were mainly distributed in the margin of tumors; the positive expression of sLeX in HCC cells in emboli or invasive tumor tissues was much higher than that in primary foci.

CONCLUSION

E-selectin and its ligand-sLeX are closely correlated with the metastasis of HCC.

[Simultaneous analysis of low concentrations of glucose, ethanol and glycerol by high performance liquid chromatographic method]

A method based on high performance liquid chromatography (HPLC) for the analysis of glucose, ethanol and glycerol simultaneously is presented. The baseline separation was achieved at room temperature (25-30 degrees C) on a Beckman mu-Spherogel carbohydrate column (6.5 mm i.d. x 30 cm) with H2SO4-H2O(0.5:1,000, V/V) as mobile phase at a flow rate of 1.000 mL/min. All the substances were detected with the Beckman 186 Refractive Index Detector. Under these conditions, distinct peaks of glucose, ethanol and glycerol were resolved within 15 min. The retention time in the particular condition was (6.04 +/- 0.04) min for glucose, (13.36 +/- 0.08) min for ethanol and (8.72 +/- 0.05) min for glycerol. The detection limit for glucose, ethanol and glycerol were found to be 10(-5) g, 10(-4) g and 10(-5) g respectively. A series of experiments have been performed to investigate the glucose consumption and the ethanol, glycerol production in the random growth of Saccharomyces cerevisiae with the method above. Only 0.5 mL sample was needed each time. In 30 hours after inoculation, the cell density increased from 10(6) mL-1 to 10(7) mL-1. It was found that the glucose concentration decreased approximately linearly after 8 hours, and ethanol and glycerol was detected after the delay period as expected. The results show that the method proposed is rapid and convenient with enough accuracy. The method may be used to investigate the metabolic behavior of yeast in the fermentation process at the early stage or detect the slight changes of concentrations of some objective substances in particular culture experiments.

[WAF1/CIP1 gene expression in human hepatocellular carcinoma and its relationship with p53 mutation]

OBJECTIVE

To study the WAF1 gene expression in human hepatocellular carcinoma(HCC) and its relationship with p53 mutation.

METHODS

Using semiquantitative reverse transcriptase-polymerase chain reaction(RT-PCR) and immunohistochemistry, the expression of WAF1 and p53 in 32 HCC samples and their surrounding liver tissues and 5 normal liver tissues was detected respectively.

RESULTS

The expression level of WAF1 mRNA in HCC samples was lower than that in paratumor liver tissues(1.06 U +/- 0.37 U vs 1.30 U +/- 0.37 U, P < 0.01) and its positive rate of p21WAF1 was also lower than that in paratumor liver tissues(53.1% vs 100%, P < 0.01). The expression level of WAF1 mRNA in HCC samples with intra-hepatic metastatic lesions was lower than that without intra-hepatic metastatic lesions(0.92 U +/- 0.33 U vs 1.24 U +/- 0.35 U, P < 0.01) and its positive rate of p21WAF1 was also lower than that without intra-hepatic metastatic lesions(33.3% vs 78.6%, P < 0.05). The expression level of WAF1 mRNA in HCC samples with p53 mutation was lower than that without p53 mutation (0.92 U +/- 0.28 U vs 1.16 U +/- 0.40 U, P < 0.05) and its positive rate of p21WAF1 was also lower than that without p53 mutation(15.4% vs 78.9%, P < 0.01). The percentage of cells in S-phase in p21WAF1-positive HCC samples was lower than that in p21WAF1-negative HCC samples(44.57% +/- 7.56% vs 51.83% +/- 8.51%, P < 0.01). However, no significant difference in expression of WAF1 mRNA and p21WAF1 in HCC samples was found in other clinical pathological parameters such as the degree of differentiation, the histological pattern, the size of tumors, the status of capsule in tumors and the formation of tumor thrombus of portal vein. The expression level of WAF1 mRNA in normal liver tissues was strikingly lower(0.17 U +/- 0.06 U), and the immunohistochemical staining of p21WAF1 in all normal liver tissues was positive(100%).

CONCLUSION

The expression of WAF1 gene in HCC is predominantly regulated by dependence on p53 and the reduced WAF1 expression may participate in the carcingenesis and progression of HCC and the mechanisms of infiltration and metastasis of HCC.

Primary liver tumors in China

Until now, no large series studies on the clinicopathological features of primary liver tumors (PLTs) in mainland China have been reported. The authors retrospectively investigated 3,160 cases of PLTs surgically resected at Shanghai Oriental Hospital of Hepatobiliary Surgery between January 1982 and January 1996. Most of them are true neoplasms, others are tumor-like lesions. The 3,160 cases of PLTs could be divided into 3 groups of 25 types arising from three germinal layers, of which tumor-like lesions (Group 1) were of 4 types involving 112 cases (3.5%), benign PLTs (Group 2) were of 10 types involving 499 cases (15.8%) and malignant PLTs (Group 3) were of 11 types involving 2,549 cases (80.7%). The most common type of lesion in each group was solitary necrotic nodule, cavernous hemangioma and hepatocellular carcinoma (HCC), accounting for 73.2%, 74.3% and 96.6% of their respective groups. The patients ranged in age from 5 months to 79 years (mean, 45.7 years), but the age distribution and sex ratio varied reciprocally from group to group and from lesion to lesion. For example, the mean age of the patients in Group 1 was 39.1 years of age, whereas in Group 2 and Group 3, it was 45.9 years and 49.6 years, respectively. The sex ratio of men to women was 2.6:1 in Group 1, 1:1.1 in Group 2 and 7.7:1 in Group 3. The rates of serum HBsAg positivity and concomitant liver cirrhosis in the patients with HCC were 74.4% and 72%, respectively, and the concomitant rate of cirrhosis in small HCC (<3 cm in diameter) was as high as 83.3% (P<0.05), demonstrating a close relationship of HCC with HBV infection and liver cirrhosis. HCC amounts to 78.4% of the total 3,160 PLTs in this series, indicating that HCC is the most common malignant tumor of the liver in China.

[Clinicopathological study on 3,160 cases of liver tumors]

OBJECTIVE

To study the developmental and clinicopathological characteristics of liver tumors in China.

METHODS

Routine methods were utilized to analyse the composition and clinicopathological features of 3,160 cases of liver tumors which were surgically resected during a period of 14 years.

RESULTS

25 types of liver tumors arising from three germinal layers were studied. Tumor-like lesions, 4 types, 112 cases (3.5%); benign tumors, 10 types, 499 cases (15.8%); malignant tumors, 11 types, 2,549 cases (80.7%). Of the three groups, the most common being inflammatory pseudotumors, accounting for 73.2% of tumor-like lesions, cavernous hemangioma, accounting for 74.3% of benign tumors and hepatocellular carcinoma, accounting for 96.8% of malignant tumors respectively. The association of cirrhosis in small hepatocellular carcinoma (< 3 cm) was as high as 83.2%.

CONCLUSION

A close relationship between HBV, liver cirrhosis and hepatocellular carcinoma exists.

Postoperative immunotherapy for patients with hepatocarcinoma using tumor-infiltrating lymphocytes

OBJECTIVE

To explore a more effective immunotherapy for cancer by studying tumor-infiltrating lymphocytes (TIL) of patients with hepatocarcinoma.

METHODS

TIL isolated from freshly resected tumors of 12 patients with hepatocarcinomas were activated, expanded and cultured in vitro by incubation with interleukin-2, and then infused to the patients. The TIL cytotoxicity and phenotype were determined by MTT and immunohistochemical ABC methods.

RESULTS

The average weight and number of cells of the tumor tissues for culture of TIL were 4.8 g and 5.8 x 10(7) respectively, and the median expansion time was 31.8 days in vitro. The maximal expansion achieved 1000 fold, and the mean amplification rate was 198.5 fold. Lymphokine-activated killer cell culture supernatant could stimulate TIL growth. Ten of 12 patients received immunotherapy of TIL. The number of cells infused reached 4 x 10(8)-1.1 x 10(10). In 3 cases of our series, TIL infusions were done through a drug pump with a catheter embedded in the hepatic artery. Eight patients whose primary hepatic carcinomas were resected completely were followed up for 16 months with only one case (12.5%) having recurrence. The recurrence rates of them at 6 and 12 months after tumor resection were remarkably lower than those of the patients who did not receive TIL infusion (19.4% and 41.6%, respectively). One patient whose tumor was not able to be removed received TIL infusion twice and local alcohol injection several times. He has been alive for 9 months.

CONCLUSIONS

TIL isolated from the tumors of patients with hepatocarcinoma can be activated and expanded in vitro. It demonstrated remarkably cytotoxic activity against tumor targets. TIL infusion is an effective immunotherapy for patients with hepatocarcinoma in reducing recurrence after operation.