Antitumor active fucoidan from the brown seaweed, umitoranoo (Sargassum thunbergii)

Neutral and acidic polysaccharides and their protein complexes were fractionated and purified from the brown seaweed umitoranoo (Sargassum thunbergii) by fractional extraction, iron-exchange chromatography, and gel filtration. Thirty-one polysaccharide fractions were obtained and tested for antitumor activity in mice with Ehrlich carcinoma transplanted i.p. Two of the fractions, GIV-A ([alpha]25D -127 degrees and mol. wt., 19,000) and GIV-B ([alpha]25D -110 degrees and mol. wt., 13,500) had such activity. On the basis of chemical and spectral analyses, these compounds were found to be a fucoidan or L-fucan containing approx. 30% sulfate ester groups per fucose residue, about 10% uronic acid, and less than 2% protein.

Antitumor active polysaccharides from the Chinese mushroom Songshan lingzhi, the fruiting body of Ganoderma tsugae

A systematic method of extraction, fractionation, and purification of polysaccharides from Songshan Lingzhi (Ganoderma tsugae) with antitumor activity was established. Seven glycans with strong antitumor activities were obtained from 14 water-soluble, and 15 water-insoluble fractions: FIo-a, FA-1, FII-1, FIII-2, and FIII-2-a, -b, and -c. FIo-a and FA-1 were protein-containing glucogalactans associated with mannose and fucose. FII-1 was a (1-->3)-beta-D-glucan having a lower protein content. The water-insoluble fractions FIII-2-a, -b, and -c were extracted with alkali, and were found to be protein-containing (1-->3)-beta-D-glucans showing the strongest activity. Chemical properties and structure of each antitumor polysaccharide were compared with three fungi of the Ganoderma family, Kofukitake (G. applanatum), Mannentake (G. lucidum), and Songshan Lingzhi (G. tsugae).

The plant WNK gene family and regulation of flowering time in Arabidopsis

The WNK (with no lysine kinase) protein kinase gene family may be involved in regulating ion homeostasis and other physiological processes in mammals. WNK-like genes have also been identified in plants, including nine in Arabidopsis, designated AtWNK1-AtWNK9. However, it is not clear if there are further plant WNK genes, and what the evolutionary relationships are among these genes, nor if these genes have functions other than their roles in regulating circadian rhythms and vacuolar H(+)-ATPase. In the present study, we found a tenth Arabidopsis WNK gene, designated AtWNK10. Further phylogenetic analysis of Arabidopsis and rice WNK genes suggests that the most recent common ancestor of monocots and eudicots had 4-8 WNK genes, and that the WNK gene family has experienced duplication events and possible gene losses. Semi-quantitative RT-PCR revealed that all Arabidopsis WNK genes except AtWNK6 are expressed in organs from the seedling to the flowering plant. T-DNA knockout mutations in the AtWNK2, AtWNK5 and AtWNK8 genes in different phylogenetic clades caused early flowering. In contrast, a T-DNA knockout wnk1 mutant had a much delayed flowering time. In addition, the transcript levels of several genes in the photoperiod pathway for flowering, such as ELF4, TOC1, CO and FT, were altered in atwnk mutants. Taken together, our results suggest that the Arabidopsis WNK gene family regulates flowering time by modulating the photoperiod pathway.

Antitumor protein-containing polysaccharides from a Chinese mushroom Fengweigu or Houbitake, Pleurotus sajor-caju (Fr.) Sings

Protein-containing polysaccharides extracted from fruiting bodies of a Chinese fungus named Feng Wei Gu, were fractionated and purified, and their antitumor activities were tested, out of which the following active fractions were obtained. FIo-a: A protein-containing xyloglucan, MW 280,000, polysaccharide: protein = 76:24 (w/w), polysaccharide consisting of Man:Gal:Xyl:Glc = 2:12:42:42 (molar ratio). [alpha]D23 + 25.3 degrees. FA-2: A protein-containing mannogalactan, MW 120,000, polysaccharide: protein = 76:16 (w/w), consisting of Xyl:Man:Gal = 9:35:56 (molar ratio), [alpha]D23 + 98.5 degrees. FII-1: A Protein-containing xylan (62:21 w/w). MW 200,000, [alpha]D23 + 8.7 degrees. FIII-1a: A protein-containing glucoxylan (15:71 w/w), [alpha]D23 + 30.7 degrees, MW 90,000, consisting of Glc:Xyl = 40:44 (molar ratio). FIII-2a: A protein-containing xyloglucan, MW 70,000, polysaccharide:protein = 69:3 (w/w), polysaccharide consisting of Xyl:Glc = 36:62 (molar ratio). [alpha]D23 + 38.6 degrees.

Antitumor polysaccharides from a Chinese mushroom, "yuhuangmo," the fruiting body of Pleurotus citrinopileatus

A water-soluble polysaccharide, FI, and water-insoluble polysaccharides, FII and FIII were extracted from Pleurotus citrinopileatus mushrooms. After fractionation, the antitumor activity of the fractions against Sarcoma 180 implanted in mice were examined, and the following active polysaccharides were obtained: Water-soluble polysaccharides FIo: A heteropolysaccharide containing 9.8% protein, and composed of glucose, mannose, arabinose, and galactose. FA-2-b-beta: A glycoprotein consisting of glycan:protein = 40:60 w/w, with the glyco-chain composed of glucose, xylose, mannose, galactose, and fucose. FA-3: A glycoprotein consisting of glycan:protein = 50:50 w/w, and glycan moiety consisting of glucose, galactose, xylose, mannose, and fucose. Water-insoluble polysaccharides. FIII-1: Protein-containing beta-D-glucans, FIII-1-a, and -b were obtained from FIII-1 by gel filtration, composed of glucan:protein = 80:20, and 68:32 w/w, respectively. The glucan moieties of both were almost all (1-->3)-beta-D-glucan, and their molecular weights were 68 x 10(4) and 40 x 10(4). FIII-2: Protein-containing beta-D-glucans, FIII-2-a, and -b, were obtained from FIII-2 by gel filtration, with molecular weights 190 x 10(4) and 120 x 10(4), respectively. Both were almost all composed of glucan:protein = 87:13 w/w. Both glucan moieties were mainly (1-->3)-beta-D-glucan.

Antitumor activity and chemical modification of polysaccharides from niohshimeji mushroom, Tricholma giganteum

Two chemical modification procedures, Smith degradation and formolysis processes, were used in an attempt to improve the antitumor activity of water-soluble and water-insoluble polysaccharides prepared from the fruiting body of niohshimeji, Tricholoma giganteum. The chemically modified products were examined for their antitumor effects on Sarcoma 180 solid tumor implanted in mice. The following results were as follows: Some Smith degradation products, i.e., O-R-Flo-c-beta and O-R-FA-2 prepared from water-soluble polysaccharides, and O-R-FII-1 and O-R-FIII-2-c from water-insoluble polysaccharides, had higher antitumor activities than the original polysaccharides. None of the formolysis products, F-Flo-a, F-W-Flo-a, F-FA-3, F-W-FA-3 from water-soluble polysaccharides, and F-FII-2, F-W-FII-2, F-FIII-2-b, and F-W-FIII-2-b prepared from water-insoluble polysaccharides had improved antitumor activities.

Antitumor active protein-containing glycans from the Chinese mushroom songshan lingzhi, Ganoderma tsugae mycelium

A water-soluble polysaccharide, FI, extracted from the mycelium of Granoderma tsugae, was fractionated and purified by ion-exchange chromatography, gel filtration, and affinity chromatography. Sixteen polysaccharides obtained were examined for antitumor effects on Sarcoma 180 in mice. The three active polysaccharides obtained were as follows: FIo-a: A glycan-protein complex containing 9.3% protein, and having a hetero-glyco-chain of mannose and xylose. FIo-b-alpha: Molecular weight 10,000, glucan-protein complex containing 25.8% protein. The inhibition ratio was 61.8% against the solid cancer Sarcoma 180/mice; the survival ratio was more than 194% of the control group (100). FA-1-b-alpha: Molecular weight 16,000, a complex of glycan:protein = 42:58 w/w, consisting of glucose as a main component, and associated with arabinose, mannose, xylose, and galactose. This had a tumor inhibition ratio of 56% and a survival ratio of more than 182%. Comparison of active glycan with the fruiting body and mycelium: Among water-soluble polysaccharides of fruiting body, FIo-a and FA-1, with antitumor activity, were both glucogalactan-protein complexes of molecular weight 10,000, but that of mycelium was a homoglucan protein complex in FIo-b-alpha and heteroglucan protein in both FA-1-a and FA-1-b-alpha. The heteroglucan had a low tumor inhibition ratio, but caused a high survival ratio in mice.

APT Weighted MRI as an Effective Imaging Protocol to Predict Clinical Outcome After Acute Ischemic Stroke

To explore the capability of the amide-proton-transfer weighted (APTW) magnetic resonance imaging (MRI) in the evaluation of clinical neurological deficit at the time of hospitalization and assessment of long-term daily functional outcome for patients with acute ischemic stroke (AIS). We recruited 55 AIS patients with brain MRI acquired within 24-48 h of symptom onset and followed up with their 90-day modified Rankin Scale (mRS) score. APT weighted MRI was performed for all the study subjects to measure APTW signal quantitatively in the acute ischemic area (APTW_ipsi) and the contralateral side (APTW_cont). Change of the APT signal between the acute ischemic region and the contralateral side (ΔAPTW) was calculated. Maximum APTW signal (APTW_max) and minimal APTW signal (APTW_min) were also acquired to demonstrate APTW signals heterogeneity (APTW_max-min). In addition, all the patients were divided into 2 groups according to their 90-day mRS score (good prognosis group with mRS score <2 and poor prognosis group with mRS score ≥2). In the meantime, ΔAPTW of these groups was compared. We found that ΔAPTW was in good correlation with National Institutes of Health Stroke Scale (NIHSS) score (R ² = 0.578, p < 0.001) and 90-day mRS score (R ² = 0.55, p < 0.001). There was significant difference of ΔAPTW between patients with good prognosis and patients with poor prognosis. Plus, APTW_max-min was significantly different between two groups. These results suggested that APT weighted MRI could be used as an effective tool to assess the stroke severity and prognosis for patients with AIS, with APTW signal heterogeneity as a possible biomarker.

Noninvasive Detection of Extracellular pH in Human Benign and Malignant Liver Tumors Using CEST MRI

PURPOSE

In this study, we aimed to use 3T magnetic resonance imaging (MRI), which is clinically available, to determine the extracellular pH (pHe) of liver tumors and prospectively evaluate the ability of chemical exchange saturation transfer (CEST) MRI to distinguish between benign and malignant liver tumors.

METHODS

Different radiofrequency irradiation schemes were assessed for ioversol-based pH measurements at 3T. CEST effects were quantified in vitro using the asymmetric magnetization transfer ratio (MTRasym) at 4.3 ppm from the corrected Z spectrum. Generalized ratiometric analysis was conducted by rationing resolved ioversol CEST effects at 4.3 ppm at a flip angle of 60 and 350°. Fifteen patients recently diagnosed with hepatic carcinoma and five patients diagnosed with hepatic hemangioma [1 male; mean age, 48.6 (range, 37-59) years] were assessed.

RESULTS

By conducting dual-power CEST MRI, the pH of solutions was determined to be 6.0-7.2 at 3T in vitro. In vivo, ioversol signal intensities in the tumor region showed that the extracellular pH in hepatic carcinoma was acidic(mean ± standard deviation, 6.66 ± 0.19), whereas the extracellular pH was more physiologically neutral in hemangioma (mean ± standard deviation, 7.34 ± 0.09).The lesion size was similar between CEST pH MRI and T2-weighted imaging.

CONCLUSION

dual-power CEST MRI can detect extracellular pH in human liver tumors and can provide molecular-level diagnostic tools for differentiating benign and malignant liver tumors at 3T.

On the use of iron octa-alkylporphyrins as models for protoporphyrin IX-containing heme systems in studies employing magnetic circular dichroism spectroscopy

The magnetic circular dichroism (MCD) properties of numerous oxidation and ligation state derivatives of myoglobin and horseradish peroxidase reconstituted with an iron octa-alkylporphyrin (mesoheme IX) have been investigated in order to establish the utility of such porphyrins as models for protoporphyrin IX-containing systems. The MCD spectra of the mesoheme-reconstituted proteins are blue-shifted (4-12 nm) and are somewhat more intense (1.5-2.5 fold) when compared to the spectra of analogous derivatives of native myoglobin and horseradish peroxidase. However, the spectral band patterns of the mesoheme-reconstituted proteins closely resemble those of the native proteins in essentially all cases. These data demonstrate that octa-alkylporphyrins can be productively used as models for protoporphyrin IX in studies of heme proteins with MCD spectroscopy.

Mutagenic effects of heavy ion radiation in plants

Genetic and developmental effects of heavy ions in maize and rice were investigated. Heavy particles with various charges and energies were accelerated at the BEVALAC. The frequency of occurrence of white-yellow stripes on leaves of plants developed from irradiated maize seeds increased linearly with dose, and high-LET heavy charged particles, e.g., neon, argon, and iron, were 2-12 times as effective as gamma rays in inducing this type of mutation. The effectiveness of high-LET heavy ion in (1) inhibiting rice seedling growth, (2) reducing plant fertility, (3) inducing chromosome aberration and micronuclei in root tip cells and pollen mother cells of the first generation plants developed from exposed seeds, and (4) inducing mutation in the second generation, were greater than that of low-LET gamma rays. All effects observed were dose-dependent; however, there appeared to be an optimal range of doses for inducing certain types of mutation, for example, for argon ions (400 MeV/u) at 90-100 Gy, several valuable mutant lines with favorable characters, such as semidwarf, early maturity and high yield ability, were obtained. Experimental results suggest that the potential application of heavy ions in crop improvement is promising. RFLP analysis of two semidwarf mutants induced by argon particles revealed that large DNA alterations might be involved in these mutants.

Vascular endothelial growth factor A (VEGFA) polymorphisms in Chinese patients with rheumatoid arthritis

OBJECTIVES

Vascular endothelial growth factor A (VEGFA) is the most potent proangiogenic molecule promoting the angiogenic phenotype of rheumatoid arthritis (RA). We hypothesized that VEGFA polymorphisms may contribute to RA susceptibility.

METHOD

We studied VEGFA rs699947 C/A, rs2010963 G/C, and rs3025039 C/T gene polymorphisms in 329 patients with RA and 697 controls in a Chinese population. Genotyping was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

RESULTS

VEGFA rs699947 C/A, rs2010963 G/C, and rs3025039 C/T polymorphisms were not associated with the risk of RA. However, in the dominant genetic model, a significantly decreased risk for RA associated with the VEGFA rs699947 CA/AA genotypes was evident among older patients and anti-cyclic citrullinated peptide antibody (ACPA)-negative patients compared with the VEGFA rs699947 CC genotype. A significantly decreased risk for RA associated with the VEGFA rs699947 CA genotype was evident among older patients.

CONCLUSIONS

These findings suggest that the functional single nucleotide polymorphism (SNP) VEGFA rs699947 C/A allele may decrease the risk of RA in older patients and ACPA-negative patients. However, our results were obtained from a moderate-sized sample and therefore this is a preliminary conclusion. Validation by a larger study from a more diverse ethnic population is needed to confirm these findings.

Purification and characterization of a lectin from the toxic mushroom Amanita pantherina

A lectin (APL) was isolated from the mushroom Amantia pantherina by means of hydrophobic chromatography on Butyl-Toyopearl, affinity chromatography on bovine submaxillary mucin (BSM)-Toyopearl and gel filtration on Superose 12 HR10/30 using a FPLC system. This lectin is composed of two identical subunits of 22 kDa and the molecular mass of the intact lectin was estimated to be 43 kDa by gel filtration. In hemagglutination inhibition assays, it exhibits sugar-binding specificities towards GlcNAc beta 1-->4Man beta-pNP, Gal beta 1-->4GlcNAc beta 1-->4GlcNAc, and Gal beta 1-->4GlcNAc beta 1-->4GlcNAc beta 1-->4GlcNAc among mono- and oligosaccharides tested. Among glycoproteins tested, BSM and asialo-BSM were the strongest inhibitors.

Antitumor-active heteroglycans from niohshimeji mushroom, Tricholoma giganteum

Water-soluble polysaccharide FI and water-insoluble polysaccharides FII, FIII-1, and FIII-2 were obtained from fruiting bodies of Tricholoma giganteum. Polysaccharides were further fractionated by ion-exchange chromatography, gel filtration, and affinity chromatography. The 24 polysaccharide fractions obtained were examined for their antitumor effect on Sarcoma 180 implanted in mice. The following antitumor-active polysaccharides were identified: FIo-a, a mixture of alpha-D-glucan and xyloglucomannan with an average molecular weight of 1.6 x 10(6); FA-1, a beta-D-glucan containing 1% protein and with a molecular weight of 4.0 x 10(4); FII-1, a (1-->3)-beta-D-glucan containing 7.8% protein, with a molecular weight of 5.2 x 10(4); FIII-1-b, a protein-polysaccharide complex (ratio, 37.5:62.5, w/w), with a molecular weight of 6.8 x 10(4) and with xylose, galactose, mannose, and glucose in the polysaccharide moiety (proportions of 8.9:14.9:29.3:46.9 by weight), and FIII-2-a, b, and c, three (1-->6)-beta-D-glucosyl-branched (1-->3)-beta-D-glucans with a molecular weight from 2.6 x 10(5) to 4.1 x 10(5) and containing small amounts of xylose and galactose and 3.5-8.3% protein.

Safety and efficacy of intravitreal injection of recombinant erythropoietin for protection of photoreceptor cells in a rat model of retinal detachment

PURPOSE

To elucidate the safety and efficacy of exogenous erythropoietin (EPO) for the protection of photoreceptor cells in a rat model of retinal detachment (RD).

METHODS

Recombinant rat EPO (400 ng) was injected into the vitreous cavity of normal rats to observe the eye manifestations. Retinal function was assessed by flash electroretinograms. Histopathological examination of retinal tissue was performed at 14 days and 2 months after injection, respectively. To investigate the inhibitory effect of EPO on photoreceptor cell apoptosis in RD rats, 100, 200, or 400 ng EPO was injected into the vitreous cavity immediately after RD model establishment. Apoptosis of photoreceptor cells was determined at 3 days after injection. Caspase-3 activation was measured by western blot analysis and immunofluorescence, respectively, and the level of Bcl-X(L) expression was analyzed by western blot.

RESULTS

Intravitreal injection of EPO 400 ng into normal rats had no significant impact on retinal function, morphology, or structure. Apoptosis of retinal photoreceptor cells apparently increased after RD and was significantly reduced following EPO treatment. The thickness of the outer nuclear layer in the RD + 400 ng group was significantly thicker than that in other experimental RD groups both at 14 days and at 2 months after RD (P < 0.05). Western blot and immunofluorescence analyses showed decreased caspase-3 activation and increased Bcl-X(L) expression following EPO treatment.

CONCLUSION

Intravitreal injection of EPO 400 ng is safe, and EPO may suppress caspase-3 activation and enhance Bcl-X(L) expression, resulting in inhibition of apoptosis and protection of photoreceptor cells.

Automated detection of intracranial artery stenosis and occlusion in magnetic resonance angiography: A preliminary study based on deep learning

BACKGROUND AND OBJECTIVES

Intracranial atherosclerotic stenosis of a major intracranial artery is the common cause of ischemic stroke. We evaluate the feasibility of using deep learning to automatically detect intracranial arterial steno-occlusive lesions from time-of-flight magnetic resonance angiography.

METHODS

In a retrospective study, magnetic resonance images with radiological reports of intracranial arterial stenosis and occlusion were extracted. The images were randomly divided into a training set and a test set. The manual annotation of lesions with a bounding box labeled "moderate stenosis," "severe stenosis," "occlusion," and "absence of signal" was considered as ground truth. A deep learning algorithm based on you only look once version 5 (YOLOv5) detection model was developed with the training set, and its sensitivity and positive predictive values to detect lesions were evaluated in the test set.

RESULTS

A dataset of 200 examinations consisted of a total of 411 lesions-242 moderate stenoses, 84 severe stenoses, 70 occlusions, and 15 absence of signal. The magnetic resonance images contained 291 lesions in the training set and 120 lesions in the test set. The sensitivity and positive predictive values were 64.2 and 83.7%, respectively. The detection sensitivity in relation to the location was greatest in the internal carotid artery (86.2%).

CONCLUSIONS

Applying deep learning algorithms in the automated detection of intracranial arterial steno-occlusive lesions from time-of-flight magnetic resonance angiography is feasible and has great potential.

Big Data and Artificial Intelligence： New Insight into the Estimation of Postmortem Interval

Abstract

The estimation of postmortem interval （PMI） is a core issue in forensic practice. A large amount of time-dependent data can be produced in the decomposition process of a body, however, such multidimensional data cannot be comprehensively and effectively analyzed and utilized by any existing conventional PMI estimation method. As a rapidly developing information technology, artificial intelligence （AI） has significant advantages in big data processing, due to it's comprehensiveness, efficiency and automation. Some scholars have already applied it to researches on the estimation of PMI, showing it's significant advantages in terms of accuracy and development prospect. This article reviews the significance, mode and progress of application of AI in PMI estimation and provides some suggestions and prospects for future study.

The value of a shorter-delay arterial spin labeling protocol for detecting cerebrovascular impairment

Background

The aim of this study was to determine the relationship between blood oxygen level dependent (BOLD) cerebrovascular reactivity (CVR) and cerebral blood flow (CBF) obtained from arterial spin labeling (ASL) using different post labeling delays (PLD).

Methods

Forty-two patients with steno-occlusive diseases and impaired CVR were divided into two groups, one scanned with a 1.5-second (1.5-s) and the other with a 2.5-second (2.5-s) PLD ASL protocol. For all patients, a region of interest (ROI) was drawn around the CVR impairment. This affected ROI was then left-right flipped across the brain midline to obtain the control ROI. For both groups, the difference in grey matter CVR between affected and control ROI was first tested to confirm significance. The average grey matter CBF of affected and control ROIs were then compared. The same analysis method was used to compare affected and control hemispheres.

Results

In both groups of 1.5-s and 2.5-s PLD, CVR values in the affected ROI (-0.049±0.055 and -0.042±0.074%/mmHg, respectively) were significantly lower compared to that in the control ROI (0.152±0.054 and 0.152±0.053%/mmHg, respectively, P<0.0001). In the group with the 1.5-s PLD, CBF in the affected ROI (37.62±11.37 mL/100 g/min) was significantly lower compared to CBF in the control ROI (44.13±11.58 mL/100 g/min, P<0.05). However, in the group with the 2.5-s PLD, no significant differences could be seen between CBF in the affected ROI (40.50±14.82 mL/100 g/min) and CBF in the control ROI (39.68±12.49 mL/100 g/min, P=0.73). In the hemisphere-based analysis, CBF was significantly lower in the affected side than in the control side for the group with the 1.5-s PLD (P<0.05) when CVR was impaired (P<0.0001), but not for the group with the 2.5-s PLD (P=0.49).

Conclusions

In conclusion, our study reveals and highlights the value of a shorter-PLD ASL protocol, which is able to reflect CVR impairment. At the same time, we offer a better understanding of the relationship between BOLD CVR and CBF obtained from ASL.

Non-traumatic hernia of the lateral abdominal wall in a patient infected with the human immunodeficiency virus

Introduction There are several classifications for abdominal hernias, and a non-traumatic lateral wall hernia (LAWH) is a rare type. We report the first case of a patient with LAWH infected with the human immunodeficiency virus (HIV). Case History A 53-year-old HIV-infected male presented with an abdominal mass. The patient had a history of treatment with combination antiretroviral therapy. A LAWH was diagnosed based on physical examination and findings of computed tomography. Open mesh repair was undertaken successfully. The patient had no evidence of a recurrent hernia during 11 months of follow-up. Conclusions High intra-abdominal pressure and weak connective tissue can lead to LAWHs. Antiretroviral therapy and lipodystrophy can cause LAWHs in HIV-infected patients.

[Clinicopathological features and prognosis of gastrointestinal stromal tumor with PDGFRA-D842V mutation]

Objective: Platelet-derived growth factor alpha (PDGFRA) mutations are respectively rare in gastrointestinal stromal tumors (GIST). Most GIST with PDGFRA exon 18 mutations including D842V mutation are highly resistant to imatinib. The treatment of GIST harboring PDGFRA primary drug-resistant mutation is a major challenge. This article aims to investigate clinicopathologic features of GIST with PDGFRA-D842V mutation and the efficacy of comprehensive treatment, providing a reference for clinical practice. Methods: A retrospective cohort study was conducted to collect the clinicopathological and follow-up data of patients with GIST harboring PDGFRA mutation who were diagnosed and treated in the GIST Clinic of Renji Hospital from January 2005 to May 2020. According to the mutation site, the enrolled patients were divided into D842V mutation group and non-D842V mutation group. The differences of clinicopathologic characteristics between the two groups were compared. Furthermore, overall survival and prognostic factors were analyzed. Results: A total of 71 patients with PDGFRA-mutant GIST were included in this study, including 47 cases of D842V mutation (66.2%) and 24 cases of non-D842V mutation (33.8%). There were 28 male patients and 19 female patients in D842V mutation group, with a median age of 60 (36-82) years. There were 16 male patients and 8 female patients in non-D842V mutation group, with a median age of 62 (30-81) years. There were no significant differences in age, gender, primary location, surgical procedure, tumor size, mitotic count, expression of CD117 and DOG1, Ki-67 proliferation index and modified NIH grade between the two groups (all P>0.05). The positive rate of CD34 was 89.4% (42/47) and 62.5% (15/24) in the D842V mutation group and the non-D842V mutation group, respectively, with a statistically significant difference (χ(2)=5.644, P=0.018). Among all the cases, 66 cases underwent R0 resection without preoperative treatment; two cases underwent emergency operation with R1 resection because of tumor rupture; 2 cases were not operated after the pathological and mutation types were confirmed by biopsy (one case received avapritinib treatment and obtain partial remission). One case was diagnosed as wild-type GIST per needle biopsy in another institute, and underwent R0 resection after preoperative imatinib treatment for 6 months. After surgery, 5 high-risk GIST patients with D842V mutation and 5 high-risk GIST patients with non-D842V mutation were treated with imatinib for more than one year. The median follow-up time was 37 (1-153) months. As of the last follow-up among the patients who received R0 resection, 4 patients with D842V mutation had relapse, of whom 1 was in the period of imatinib administration, and the 3-year relapse-free survival rate was 94.2%; none of the patients with non-D842V mutation had relapse. There was no statistically significant difference in relapse-free surivval between two groups (P=0.233). Univariate analysis revealed that mitotic count (P=0.002), Ki-67 proliferation index (P<0.001) and modified NIH grade (P=0.025) were the factors associated with relapse-free survival of patients with D842V mutation after R0 resection (all P<0.05). However, the above factros were not testified as independant prognostic facors in multivariate Cox analysis (all P<0.05). Conclusion: Clinicopathologic features and the efficacy of radical resection in patients with PDGFRA-D842V mutation are similar to those in patients with non-D842V mutation.

Repurposing of the PET Probe Prototype PiB for Label and Radiation-Free CEST MRI Molecular Imaging of Amyloid

Positron emission tomography (PET) probes are specific and sensitive while suffering from radiation risk. It is worthwhile to explore the chemical emission saturation transfer (CEST) effects of the probe prototypes and repurpose them for CEST imaging to avoid radiation. In this study, we used 11C-PiB as an example of a PET probe for detecting amyloid and tested the feasibility of repurposing this PET probe prototype, PiB, for CEST imaging. After optimizing the parameters through preliminary phantom experiments, we used APP/PS1 transgenic mice and age-matched C57 mice for in vivo CEST magnetic resonance imaging (MRI) of amyloid. Furthermore, the pathological assessment was conducted on the same brain slices to evaluate the correlation between the CEST MRI signal abnormality and β-amyloid deposition detected by immunohistochemical staining. In our results, the Z-spectra revealed an apparent CEST effect that peaked at approximately 6 ppm. APP/PS1 mice as young as 9 months injected with PiB showed a significantly higher CEST effect compared to the control groups. The hyperintense region was correlated with the Aβ deposition shown by pathological staining. In conclusion, repurposing the PET probe prototype for CEST MRI imaging is feasible and enables label- and radiation-free detection of the amyloid while maintaining the sensitivity and specificity of the ligand. This study opens the door to developing CEST probes based on PET probe prototypes.

[A seroepidemiological survey: antibody to HTLV-1 in sera from various populations in Guangdong Province]

A seroepidemiological survey of HTLV-1 infection in Guangdong Province was reported. 2224 serum samples from various populations were collected and antibodies to HTLV-1 in sera were detected with indirect immunofluorescent assay. Total seropositive rate was 1.57% (35/2224). The antibody positive rates of HTLV-1 in sera from healthy individuals (n = 1810), blood donors (n = 248), patients with T cell leukemia (n = 109) and patients with neurological diseases (n = 57) were 1.27%, 0.40 %, 7.30% and 5.26% respectively. There was a significant difference between the patients with T cell leukemia and the healthy individuals (P<0.005).