Toripalimab plus capecitabine in the treatment of patients with residual nasopharyngeal carcinoma: a single-arm phase 2 trial

Patients with residual nasopharyngeal carcinoma after receiving definitive treatment have poor prognoses. Although immune checkpoint therapies have achieved breakthroughs for treating recurrent and metastatic nasopharyngeal carcinoma, none of these strategies have been assessed for treating residual nasopharyngeal carcinoma. In this single-arm, phase 2 trial, we aimed to evaluate the antitumor efficacy and safety of toripalimab (anti-PD1 antibody) plus capecitabine in patients with residual nasopharyngeal carcinoma after definitive treatment (ChiCTR1900023710). Primary endpoint of this trial was the objective response rate assessed according to RECIST (version 1.1). Secondary endpoints included complete response rate, disease control rate, duration of response, progression-free survival, safety profile, and treatment compliance. Between June 1, 2020, and May 31, 2021, 23 patients were recruited and received six cycles of toripalimab plus capecitabine every 3 weeks. In efficacy analyses, 13 patients (56.5%) had complete response, and 9 patients (39.1%) had partial response, with an objective response rate of 95.7% (95% CI 78.1-99.9). The trial met its prespecified primary endpoint. In safety analyses, 21 of (91.3%) 23 patients had treatment-related adverse events. The most frequently reported adverse event was hand-foot syndrome (11 patients [47.8%]). The most common grade 3 adverse event was hand-foot syndrome (two patients [8.7%]). No grades 4-5 treatment-related adverse events were recorded. This phase 2 trial shows that combining toripalimab with capecitabine has promising antitumour activity and a manageable safety profile for patients with residual nasopharyngeal carcinoma.

[Value of radiomics model based on dynamic contrast-enhanced magnetic resonance imaging in differentiation fat-poor angiomyolipoma from alpha-fetoprotein-negative hepatocellular carcinoma in the background of non-cirrhotic liver]

Objective: To explore the value of radiomics model based on dynamic contrast-enhanced magnetic resonance imaging (MRI) in differentiation fat-poor angiomyolipoma (fp-AML) from alpha-fetoprotein-negative hepatocellular carcinoma (n-HCC) in the background of non-cirrhotic liver. Methods: The complete data of 121 patients from Guangdong Provincial People's Hospital, Zhongshan Hospital Affiliated to Fudan University and Sun Yat-sen University Cancer Center with hepatic fp-AML and n-HCC confirmed by pathology from October 2010 to July 2020 were retrospectively analyzed. Among them, 75 were males and 46 were females, aged from 23 to 80 (55±12) years. A total of 93 patients from Zhongshan Hospital Affiliated to Fudan University were divided into the training cohort (n=75) and internal test cohort (n=18) according to entry time, and the patients of other 2 hospitals were divided into external test cohort (n=28). The radiomics features were extracted from the preoperative triple-phase contrast-enhanced images. The feature selection algorithm based on Joint Mutual Information Maximisation (JMIM) was used to extract the optimal feature subset, and support vector machine (SVM) was used to build the radiomics model. The diagnostic performance of radiomics model was evaluated using the receiver operating characteristic (ROC) curve, and was compared with that of two radiologists. Results: In the internal cohort, the area under the curve (AUC) for the differential diagnosis between fp-AML and n-HCC of the radiomics model was 0.819 (with an accuracy of 72.2%), outperforming than radiologist 1 with 10 years of diagnostic experience (AUC=0.542, P=0.029) and radiologist 2 with 2 years of diagnostic experience (AUC=0.375, P=0.004). In the external cohort, the AUC of the radiomics model was 0.772 (with and accuracy of 71.4%), which was comparable to that of radiologist 1 (AUC=0.661, P=0.442) and better than that of radiologist 2 (AUC=0.400, P=0.008). Conclusion: The radiomics model based on dynamic contrast-enhanced MRI is of high accuracy for preoperatively differentiating hepatic fp-AML from n-HCC in the noncirrhotic liver.

Low value of whole-body dual-modality [18f]fluorodeoxyglucose positron emission tomography/computed tomography in primary staging of stage I-II nasopharyngeal carcinoma: a nest case-control study

Objectives

The value of using PET/CT for staging of stage I–II NPC remains unclear. Hence, we aimed to investigate the survival benefit of PET/CT for staging of early-stage NPC before radical therapy.

Methods

A total of 1003 patients with pathologically confirmed NPC of stages I–II were consecutively enrolled. Among them, 218 patients underwent both PET/CT and conventional workup ([CWU], head-and-neck MRI, chest radiograph, liver ultrasound, bone scintigraphy) before treatment. The remaining 785 patients only underwent CWU. The standard of truth (SOT) for lymph node metastasis was defined by the change of size according to follow-up MRI. The diagnostic efficacies were compared in 218 patients who underwent both PET/CT and CWU. After covariate adjustment using propensity scoring, a cohort of 872 patients (218 with and 654 without pre-treatment PET/CT) was included. The primary outcome was overall survival based on intention to treat.

Results

Retropharyngeal lymph nodes were metastatic based on follow-up MRI in 79 cases. PET/CT was significantly less sensitive than MRI in detecting retropharyngeal lymph node lesions (72.2% [62.3–82.1] vs. 91.1% [84.8–97.4], p = 0.004). Neck lymph nodes were metastatic in 89 cases and PET/CT was more sensitive than MRI (96.6% [92.8–100.0] vs. 76.4% [67.6–85.2], p < 0.001). In the survival analyses, there was no association between pre-treatment PET/CT use and improved overall survival, progression-free survival, local relapse-free survival, regional relapse-free survival, and distant metastasis-free survival.

Conclusions

This study showed PET/CT is of little value for staging of stage I–II NPC patients at initial imaging.

Key Points

• PET/CT was more sensitive than MRI in detecting neck lymph node lesions whereas it was significantly less sensitive than MRI in detecting retropharyngeal lymph node lesions.

• No association existed between pre-treatment PET/CT use and improved survival in stage I–II NPC patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07478-1.

Proteomics and Its Application in Forensic Pathology

Proteomics has become one of the hot topics in modern life sciences. Its application prospects have been confirmed in clinical medical research, such as the discovery of new disease biomarkers, identification of disease-related proteins, and development of new drug targets. However, in the field of forensic science, especially in forensic pathology, it is still in the stage of exploration. This paper reviews the research techniques and the use of proteomics in forensic pathology in domestic and foreign scholars, in order to provide new ideas for the research and application of forensic pathology.

[Clinical outcome of allogeneic hematopoietic stem cell transplantation in the treatment of 9 myeloid leukemia patients with granulocytic sarcoma]

To explore the efficacy and influencing factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myeloid leukemia and granulocytic sarcoma (GS). Clinical outcome including hematopoietic reconstitution, transplant-related complications, survival and relapse were collected and retrospectively analyzed in 9 patients with myeloid leukemia and GS after allo-HSCT. Hematopoiesis reconstitution was achieved in all the 9 recipients. Four cases developed acute graft-versus-host disease (GVHD), and 1 with chronic GVHD. The median follow-up time after transplantation was 10(4-81) months. Only 2 cases survived, the other 7 died of relapse. The median time of relapse after transplantation was 5(3-19) months. Allo-HSCT is relatively effective treatment for patients with myeloid leukemia and GS. Relapse after transplantation remains the major factor of mortality.

[Outcome analysis of allogeneic hematopoietic stem cell transplantation for 41 patients with severe aplastic anemia]

目的

评价异基因造血干细胞移植（allo-HSCT）治疗重型再生障碍性贫血（SAA）患者的疗效。

方法

回顾性分析2001年10月至2015年5月接受allo-HSCT治疗的41例SAA患者的临床资料。其中男27例，女14例，中位年龄为17(2~43）岁。其中同胞相合移植24例，无关供者移植17例。

结果

38例患者移植后获得造血重建，造血重建率为92.68%。可评估患者的中性粒细胞和血小板的中位植入时间分别为16(10~57) d和20(9~83) d。13例发生急性移植物抗宿主病（aGVHD），8例发生慢性移植物抗宿主病，5例发生移植物排斥反应。中位随访27(3~154）个月，预期3年总生存（OS）率为（75.1±8.3）%。10例患者死亡，移植相关死亡率为24.39%。多因素分析结果显示：移植后发生Ⅱ~Ⅳ度aGVHD[P=0.018，OR=27.481(95% CI 2.377~392.636）]和侵袭性真菌病[P=0.021，OR=21.364(95% CI 1.732~354.185）]为影响SAA患者allo-HSCT后OS的独立危险因素。

结论

同胞相合供者和HLA匹配的无关供者allo-HSCT是治疗SAA患者的有效手段，Ⅱ~Ⅳ度aGVHD和侵袭性真菌病与移植后OS率较低有关。

[A comparative study of unrelated donor and matched-sibling donor allogeneic hematopoietic stem cell transplantation in children and adolescents with acquired severe aplastic anemia]

Objective: To evaluate the efficacy of unrelated donor allogeneic hematopoietic stem cell transplantation(URD allo-HSCT) for children and adolescents with severe aplastic anemia (SAA). Methods: Clinical data of 34 SAA children and adolescents undergoing allo-HSCT were retrospectively analyzed from October 2001 to October 2015. According to the source of donor, the patients were divided into matched sibling donor allo-HSCT group (MSD group) and unrelated donor group (URD group). The clinical outcome of SAA children and adolescents receiving URD allo-HSCT was assessed, and patients in MSD allo-HSCT group were enrolled as control at the same period. Results: The rate of hematopoietic reconstitution, the time of neutrophil and platelet engraftment, incidence of chimerism and graft rejection between two groups were not statistically different.The incidence of acute graft-versus-host disease (GVHD) in URD group was significantly higher than that in MSD group [42.9%(6/14) vs 10.5%(2/19), P=0.047]. The incidence of grade Ⅱ-Ⅳ acute GVHD and chronic GVHD in URD were higher than those in MSD group [21.4%(3/14) vs 5.3%(1/19), P=0.288; 35.7%(5/14) vs 5.3%(1/19), P=0.062, respectively], yet without significant difference between two groups. Other transplant-related complications including pulmonary complications, hemorrhagic cystitis, incidence of EBV and CMV reactivation and venous occlusive disease were comparable with two regimens. Estimated 5-years overall survival (OS) rate and disease free survival (DFS) rate were not statistically significant between URD group and MSD group [(84.4±6.6)% vs (89.4±7.1)%, (82.5±5.4)% vs (82.1±4.3)%; P=0.766, P=0.884, respectively]. Conclusions: By multivariate analysis, the outcome of URD allo-HSCT in SAA children and adolescent is similar to MSD allo-HSCT. It could be an alternative option as the first-line treatment for SAA children and adolescents without HLA matched sibling donors.

Primary renal synovial sarcoma: computed tomography imaging findings

BACKGROUND

A synovial sarcoma arising from the kidney is extremely rare. To date, few data are available on their radiological features.

PURPOSE

To identify the computer tomography (CT) imaging findings of primary renal synovial sarcomas (PRSSs).

MATERIAL AND METHODS

Five cases of PRSS confirmed by histopathological and cytogenetic studies were retrospectively analyzed. All patients had undergone unenhanced and multiphase enhanced CT examinations (one patient underwent CT twice). The CT characteristics, including shape, size, margin, attenuation, and enhancement pattern after intravenous contrast medium injection, were analyzed.

RESULTS

The study involved two female and three male patients (mean age, 27.4 years; range, 15-43 years). Unenhanced CT showed completely or partly well-defined masses, with heterogeneous (n = 5) or homogeneous (n = 1) patchy low density. On multiphase contrast-enhanced CT, in five of the six CT examinations, the tumors appeared as solid-cystic masses with cyst walls or pseudo-capsules, and demonstrated moderately heterogeneous (n = 5) and/or septate enhancement (n = 2), with a "rapid wash-in and slow wash-out" pattern of enhancement in the solid component. Only one tumor showed a simple cyst appearance and developed an irregular, intratumoral, septate soft density 8 months later. A renal vein and inferior vena cava thrombus was noticed in one patient, while lymphadenopathy was not observed in any patient.

CONCLUSION

PRSS should be included in the differential diagnosis when an adolescent or young adult presents with a renal neoplasm appearing as a solid-cystic mass with well-defined borders, a cystic wall or pseudo-capsule, heterogeneous or septate enhancement, a "rapid wash-in and slow wash-out" pattern of enhancement in the solid component, and no sign of lymphadenopathy.

Correlation analysis between starch properties and single nucleotide polymorphisms of waxy genes in common rye (Secale cereale L.)

To understand the relationships between single nucleotide polymorphisms (SNPs) in the waxy gene and starch parameters in common rye, we performed sequence characterization, enzyme activity testing, amylopectin/amylose ratio evaluation, starch property testing, and correlation analysis. Specific primers were used to clone waxy from 20 rye cultivars. Sequence analysis showed that waxy was 2852 bp, including 11 exons, and sequence similarity across the 20 cultivars was over 98%. The Waxy protein showed >95% similarity with those from wheat, rice, and barley, the closest genetic relationship being with wheat Wx-A type. Waxy had multiple SNPs, most of which were located in the exons. Amino acid variants were found to be mainly distributed in the catalytic domain in an imbalanced state. Multi-factor correlation analysis revealed significant correlation among starch pasting parameters in rye flour. The Waxy protein activity was significantly negatively correlated with the amylose content and amylopectin/amylose ratio. However, pasting parameters, Waxy enzyme activity, and amylopectin/amylose content ratio were not correlated. The correlation of SNPs, the key catalytic site of Waxy, with starch parameters and enzyme activity suggested that both starch pasting parameters and Waxy protein activity were influenced by No. 260 amino acid (aa). Further, the 141 and 152 aa loci were found in the enzyme-catalyzing domain of Waxy. Interestingly, Waxy enzyme activity was also influenced by the 363 aa locus in the pliable region. These results provide important theoretical regarding the high-throughput quality identification of noodle starch, functional studies, directional selection, and molecular markers of wheat Wx subunits.

Isolation and characterization of two VpYABBY genes from wild Chinese Vitis pseudoreticulata

The establishment of abaxial-adaxial polarity is an important feature of the development of lateral organs in plants. Members of the YABBY gene family may be specific to seed-plant-specific transcriptional regulators that play critical roles in promoting abaxial cell fate in the model eudicot, Arabidopsis thaliana. However, recent study has shown that the roles of YABBY genes are not conserved in the development of angiosperms. The establishment of abaxial-adaxial polarity has not been studied in perennial fruit crops. Grapes are an important fruit crop in many regions of the world. Investigating YABBY genes in grapevines should help us to discover more about the key genetic and molecular pathways in grapevine development. To understand the characterization of YABBY genes in grapevines, two YABBY genes, VpYABBY1 (GenBank accession No. KC139089) and VpYABBY2 (GenBank accession No. KC139090), were isolated from the wild Chinese species Vitis pseudoreticulata. Both of these encode YABBY proteins. Sequence characterization and phylogenetic analyses show that VpYABBY1 is group classified into the FIL subfamily while VpYABBY2 is a member of the YAB2 subfamily of Arabidopsis thaliana. Subcellular localization analysis indicates that VpYABBY1 and VpYABBY2 proteins are localized in the nucleus. Tissue specific expressional analysis reveals that VpYABBY1 is expressed strongly in young leaves of grape but only weakly in the mature leaves. Meanwhile, VpYABBY2 is expressed in grape stems, flowers, tendrils, and leaves. Transgenic Arabidopsis plants ectopically expressing VpYABBY1 caused the partial abaxialization of the adaxial epidermises of leaves, behaving similarly to those over-expressing FIL or YAB3 with abaxialized lateral organs. By contrast, ectopic expression of VpYABBY2 in Arabidopsis did not cause any alteration in the adaxial-abaxial polarity. Sequence characterization and phylogenetic analysis revealed that VpYABBY1 and VpYABBY2 are group-classified into two different subfamilies. They have diverged functionally in the control of lateral organ development. VpYABBY1 may have a function in leaf development, while VpYABBY2 may play a specific role in carpel development and grape berry morphogenesis. It is further possible that during the evolution of different species, YABBY family members have preserved different expression regulatory systems and functions.

Abnormal baseline brain activity in patients with HBV-related cirrhosis without overt hepatic encephalopathy revealed by resting-state functional MRI

Neurocognitive dysfunction of varying degrees is common in patients with hepatitis B virus-related cirrhosis (HBV-RC) without overt hepatic encephalopathy (OHE). However, the neurobiological mechanisms underlying these dysfunctions are not well understood. We sought to identify changes in the neural activity of patients with HBV-RC without OHE in the resting state by using the amplitude of low-frequency fluctuation (ALFF) method and to determine whether these changes were related to impaired cognition. Resting-state functional MRI data from 30 patients with HBV-RC and 30 healthy controls matched for age, sex, and years of education were compared to determine any differences in the ALFF between the two groups. Cognition was measured with the psychometric hepatic encephalopathy score (PHES), and the relationship between these scores and ALFF variation was assessed. Compared with controls, patients showed widespread lower standardized ALFF (mALFF) values in visual association areas (bilateral lingual gyrus, middle occipital gyrus, and left inferior temporal gyrus), motor-related areas (bilateral precentral gyrus, paracentral lobule, and right postcentral gyrus), and the default mode network (bilateral cuneus/precuneus and inferior parietal lobule). Higher mALFF values were found in the bilateral orbital gyrus/rectal gyrus. In patients, mALFF values were significantly positive correlated with the PHES in the right middle occipital gyrus and bilateral precentral gyrus. Our findings of resting-state abnormalities in patients with HBV-RC without OHE suggest that neurocognitive dysfunction in patients with HBV-RC without OHE may be caused by abnormal neural activity in multiple brain regions.

Abnormal regional homogeneity of resting-state brain activity in patients with HBV-related cirrhosis without overt hepatic encephalopathy

BACKGROUND

Many studies have reported that cognitive deficits exist in cirrhotic patients without overt hepatic encephalopathy (OHE). However, the neurobiological mechanisms underlying these deficits are still not fully understood.

AIM

To investigate regional activity abnormalities in patients with hepatitis B virus-related cirrhosis (HBV-RC) without OHE using resting-state functional MRI (Rs-fMRI), and to examine the relationship between regional activity abnormalities and impaired cognition.

METHODS

A newly reported regional homogeneity (ReHo) approach was used to compare the local synchronization of Rs-fMRI signals in 32 patients with HBV-RC without OHE and 32 well-matched healthy controls. Cognition was measured in all patients using psychometric hepatic encephalopathy score (PHES) tests, and the relationship between ReHo variation and PHES was analysed.

RESULTS

Relative to healthy controls, the cirrhosis group showed high ReHo in the prefrontal cortex, and widespread low ReHo in visual association areas (left lingual gyrus, middle temporal gyrus and right middle occipital gyrus), motor association areas (bilateral precentral gyrus and paracentral lobule) and the bilateral precuneus. Correlation analysis of the mean ReHo values in different brain areas and PHES in cirrhotic patients revealed a significantly positive correlation in the left lingual gyrus (r = 0.352; P = 0.048), right middle occipital gyrus (r = 0.453; P = 0.009) and bilateral precentral gyrus (left: r = 0.436, P = 0.013; right: r = 0.582, P < 0.001), paracentral lobule (r = 0.485; P = 0.005) and precuneus (r = 0.468; P = 0.007).

CONCLUSIONS

Our results provide information on the pathophysiological mechanisms underlying cognitive alterations in cirrhotic patients and demonstrate the feasibility of using Rs-fMRI with ReHo analysis as a noninvasive modality with which to detect the progression of cognitive changes in cirrhotic patients.

Regional homogeneity changes in heroin-dependent individuals: resting-state functional MR imaging study

PURPOSE

To identify heroin-related modulations of neural activity in the resting state in heroin-dependent individuals (HDIs) by using resting-state functional magnetic resonance (MR) imaging and a regional homogeneity method and to investigate whether these changes of neural activity can be related to duration of heroin use and to decision-making deficits in HDIs.

MATERIALS AND METHODS

This prospective study was approved by the appropriate ethics committee, and written informed consent was obtained from each participant. Thirty-one HDIs receiving methadone-maintained treatment and 24 control subjects participated. Resting-state functional MR imaging was performed by using a gradient-echo echo-planar imaging sequence. Regional homogeneity was calculated by using software. Voxel-based analysis of the regional homogeneity maps between control and HDI groups was performed with two-sample t tests by using software. Statistical maps were set at P less than .05 and were corrected for multiple comparisons. The Iowa gambling task (IGT) was used to assess participant decision making during uncertainty. Abnormal clusters revealed by group comparison were extracted and correlated with behavioral performance at the IGT and with duration of heroin use.

RESULTS

Regional homogeneity was diminished in the bilateral medial orbitofrontal cortex (OFC), bilateral dorsal medial thalamus, bilateral cuneus, and lingual gyrus in HDIs compared with control subjects. There were negative correlations between mean regional homogeneity in the medial OFC, bilateral cuneus, and lingual gyrus and duration of heroin use. There was a positive correlation between mean regional homogeneity in the medial OFC and performance level at the IGT.

CONCLUSION

The present study reveals resting-state abnormalities in HDIs that may lead to further improvement of the understanding of the neural substrates of cognitive impairment in HDIs.

Influence of data preprocessing on the quantitative determination of nutrient content in poultry manure by near infrared spectroscopy

With increasing concern over potential polltion from farm wastes, there is a need for rapid and robust methods that can analyze livestock manure nutrient content. The near infrared spectroscopy (NIRS) method was used to determine nutrient content in diverse poultry manure samples (n=91). Various standard preprocessing methods (derivatives, multiplicative scatter correction, Savitsky-Golay smoothing, and standard normal variate) were applied to reduce data systemic noise. In addition, a new preprocessing method known as direct orthogonal signal correction (DOSC) was tested. Calibration models for ammonium nitrogen, total potassium, total nitrogen, and total phosphorus were developed with the partial least squares (PLS) method. The results showed that all the preprocessed data improved prediction results compared with the non-preprocessing method. Compared with the other preprocessing methods, the DOSC method gave the best results. The DOSC method achieved moderately successful prediction for ammonium nitrogen, total nitrogen, and total phosphorus. However, all preprocessing methods did not provide reliable prediction for total potassium. This indicates the DOSC method, especially combined with other preprocessing methods, needs further study to allow a more complete predictive analysis of manure nutrient content.

Prediction of the nutrient content in dairy manure using artificial neural network modeling

Nutrients in animal manure are valuable inputs in agronomic crop production. Timely and reliable information on animal manure nutrient content will facilitate the utilization of manure as organic fertilizer and reduce any associated potential environmental problems. The objective of this study was to investigate the feasibility of using multiple linear regression (MLR), polynomial regression, and artificial neural network (ANN) models to determine nutrient content in dairy manure. Fresh manure samples (n = 86) from Holstein dairy cattle were collected from 34 dairy farms located in Beijing city, China. All samples were analyzed for nutrient content (ammonium nitrogen, total potassium, total nitrogen, and total phosphorus) by standard laboratory methods. The physicochemical properties (specific gravity, electrical conductivity, and pH) of dairy manure samples were measured. Relationships between nutrient content and physicochemical properties were explored by MLR, polynomial regression, and ANN models. Several parameters (R(2), modeling efficiency statistic, mean squared error of prediction, mean bias, linear bias, and maximum bias) were calculated to evaluate model performance. The residual analysis results indicated that all MLR models for the testing data set had significant mean and linear bias. When compared with MLR and polynomial regression models, the ANN model for all nutrient contents had better performance with higher R(2) and modeling efficiency statistics and lower mean squared error of prediction, mean bias, linear bias, and maximum bias. These findings demonstrated that the ANN model may be an appropriate tool to predict dairy manure nutrient content.

The effect of an inoculant and enzymes on fermentation and nutritive value of sorghum straw silages

The objectives of this study were to determine the effect of inoculant, enzymes and inoculant-enzymes mixture on fermentation quality, nutritive value, and microbial changes of sorghum straw silage. Sorghum straws were collected and treated with distilled water (control), inoculant, enzymes and inoculant+enzymes prior to ensiling. Three bag silos for each silage (denoted C, I, E and I+E, respectively) were opened after 3, 7, 11, 15, 30 and 60 days for chemical and microbial analyses. For all the silages, there was a rapid decline in pH during the first 3 days of ensiling. Relative to silage C, all the treatment (I, E and I+E) had higher (P<0.05) lactic acid concentration at all ensiling periods. Population of LAB during all ensiling time was numerically greater for treated than control silages. Separate addition of two additives, especially for enzymes, can effectively (P<0.05) decrease aNDF and ADF concentration. Treatments with enzymes (E, I+E) can also improve significantly silage IVDMD and IVNDFD concentration. These results indicated that the addition of additives can improve the sorghum straw silage fermentation quality at different extent.

[Determination of carfentrazone-ethyl(F8426) residue in soil and wheat by wide-bore capillary gas chromatography]

An efficient method for determining F8426 of Affinity 40 DF in soil and wheat is described. F8426 was extracted from the soil and the wheat sample with acetone-water (80:20, volume ratio), and the extract was partitioned with petroleum ether. Then the upper layer was concentrated and cleaned up on a micro-column of Florisil and activated carbon mixture. Finally F8426 was separated from other interfering components through wide-bore capillary gas chromatographic column (OV-1701, 12 m x 0.53 mm i.d.), and was detected by electron capture detector (ECD). The lowest detection limit for F8426 was 0.02 ng. The lowest detectable concentrations in wheat and soil was 2 micrograms/kg and 1 microgram/kg respectively. The average recovery and coefficient of variation of this method were 89.60%-97.53% and 4.42%-8.67% respectively. This method is simple, sensitive and suitable for residue analysis of F8426.

[A study on physical characteristics of porous plates for water sublimator]

Objective. To investigate the development method of porous plate, the key part of water sublimator, and its main physical characteristics. Method. Technical parameters of porous plates used in water sublimator were analyzed. On the basis of this, porous plates made of different materials were developed by making use of sintered powder technology. A tester for testing the physical characteristics of porous plate was designed. All around physical characteristic tests for porous plates were conducted. Result. Main factors affecting performance of porous plates were tested. These provided basis for performance test of sublimator, established porous plate criterion and optimized porous plate. Conclusion. Porous plates developed by making use of sintered powder technology could meet requirements of performance of water sublimator.

Comparison of bone single-photon emission tomography and planar imaging in the detection of vertebral metastases in patients with back pain

Bone scan has long been considered to be an important diagnostic test in searching for bone metastases. However, considerable difficulty is encountered in the vertebral region due to the complexity of structures and the fact that other benign lesions, especially degenerative changes, are very common there. Single-photon emission tomography (SPET) has been reported to be useful in the differentiation of benign from malignant conditions. Here we report our experience with bone SPET in the diagnosis of vertebral metastases. This is a retrospective study of technetium-99m methylene diphosphonate (MDP) bone scans in 174 consecutive patients who were referred for the investigation of back pain in our department. MDP planar and SPET images were obtained. Of teh 174 patients, 98 had a known history of malignant tumours. The diagnosis of vertebral metastasis was made on the basis of the patients' clinical histories and the findings with other imaging techniques such as magnetic resonance imaging, computed tomography or follow-up bone scan. We found that the presence of pedicle involvement as seen on SPET was an accurate diagnostic criterion of vertebral metastasis. SPET had a sensitivity of 87%, a specificity of 91%, a positive predictive value of 82%, a negative predictive value of 94% and an accuracy of 90%. On the other hand, planar study had a sensitivity of 74%, a specificity of 81%, a positive predictive value of 64%, a negative predictive value of 88% and an accuracy of 79% in diagnosing vertebral metastasis. Except with regard to the negative predictive value, SPET performed statistically better than planar imaging. Only 9/147 (6.4%) lesions involving the vertebral body alone and 3/49 (6.1%) lesions involving facet joints alone were subsequently found to be metastases. We conclude that bone SPET is an accurate diagnostic test for the detection of vertebral metastases and is superior to planar imaging in this respect.

Transduction of human renal carcinoma cells with human gamma-interferon gene via retroviral vector

We used a retroviral vector containing a human gamma-interferon (gamma-IFN) gene to transduce 13 renal carcinoma cell lines. The transduction efficiencies ranged from 0% to 60%, as determined by using an analogous vector containing the LacZ marker gene. In addition, gene-transferred resistance to the antibiotic neomycin was used to select for transduced cells. Nine of 13 lines were successfully transduced. Transduction was associated with the morphologic change of elongation, and there was a marked decrease in cell growth rate. Transduced cells secreted varying amounts (20-1076 pg/10(6) cells/d) of gamma-IFN as measured by enzyme-linked immunosorbent assay for at least 2 to 3 weeks after transduction (including 1 day of transduction, 6-7 days of selection, and an additional 8-12 days before the first passage of the transduced cells). Human leukocyte antigen (HLA) class II expression was markedly increased in six of seven cell lines; HLA class I expression was significantly increased in two of eight lines. Transduced cells that were subjected to cryopreservation after irradiation still produced gamma-IFN and expressed HLA class I and II antigens, although generally at lower levels than before these manipulations. This study confirms that retroviral vector transduction of the human gamma-IFN gene into renal carcinoma cells is feasible and associated with persistent production of gamma-IFN and increased expression of HLA class I and II molecules, and these effects are retained after irradiation and cryopreservation. This suggests that an autologous tumor cell vaccine trial with irradiated gamma-IFN gene-transduced renal carcinoma cell is rationale and feasible.