A TGF-β-dominant chemoresistant phenotype of hepatoblastoma associated with aflatoxin exposure in children

BACKGROUND AND AIMS

Hepatoblastoma (HB) is the most common liver cancer in children, posing a serious threat to children's health. Chemoresistance is the leading cause of mortality in patients with HB. A more explicit definition of the features of chemotherapy resistance in HB represents a fundamental urgent need.

APPROACH AND RESULTS

We performed an integrative analysis including single-cell RNA sequencing, whole-exome sequencing, and bulk RNA sequencing in 180 HB samples, to reveal genomic features, transcriptomic profiles, and the immune microenvironment of HB. Multicolor immunohistochemistry staining and in vitro experiments were performed for validation. Here, we reported four HB transcriptional subtypes primarily defined by differential expression of transcription factors. Among them, the S2A subtype, characterized by strong expression of progenitor ( MYCN , MIXL1 ) and mesenchymal transcription factors ( TWIST1 , TBX5 ), was defined as a new chemoresistant subtype. The S2A subtype showed increased TGF-β cancer-associated fibroblast and an immunosuppressive microenvironment induced by the upregulated TGF-β of HB. Interestingly, the S2A subtype enriched SBS24 signature and significantly higher serum aflatoxin B1-albumin (AFB1-ALB) level in comparison with other subtypes. Functional assays indicated that aflatoxin promotes HB to upregulate TGF-β. Furthermore, clinical prognostic analysis showed that serum AFB1-ALB is a potential indicator of HB chemoresistance and prognosis.

CONCLUSIONS

Our studies offer new insights into the relationship between aflatoxin and HB chemoresistance and provide important implications for its diagnosis and treatment.

Deep whole-genome analysis of 494 hepatocellular carcinomas

Over half of hepatocellular carcinoma (HCC) cases diagnosed worldwide are in China1-3. However, whole-genome analysis of hepatitis B virus (HBV)-associated HCC in Chinese individuals is limited4-8, with current analyses of HCC mainly from non-HBV-enriched populations9,10. Here we initiated the Chinese Liver Cancer Atlas (CLCA) project and performed deep whole-genome sequencing (average depth, 120×) of 494 HCC tumours. We identified 6 coding and 28 non-coding previously undescribed driver candidates. Five previously undescribed mutational signatures were found, including aristolochic-acid-associated indel and doublet base signatures, and a single-base-substitution signature that we termed SBS_H8. Pentanucleotide context analysis and experimental validation confirmed that SBS_H8 was distinct to the aristolochic-acid-associated SBS22. Notably, HBV integrations could take the form of extrachromosomal circular DNA, resulting in elevated copy numbers and gene expression. Our high-depth data also enabled us to characterize subclonal clustered alterations, including chromothripsis, chromoplexy and kataegis, suggesting that these catastrophic events could also occur in late stages of hepatocarcinogenesis. Pathway analysis of all classes of alterations further linked non-coding mutations to dysregulation of liver metabolism. Finally, we performed in vitro and in vivo assays to show that fibrinogen alpha chain (FGA), determined as both a candidate coding and non-coding driver, regulates HCC progression and metastasis. Our CLCA study depicts a detailed genomic landscape and evolutionary history of HCC in Chinese individuals, providing important clinical implications.

SCAR: Single-cell and Spatially-resolved Cancer Resources

Advances in sequencing and imaging technologies offer a unique opportunity to unravel cell heterogeneity and develop new immunotherapy strategies for cancer research. There is an urgent need for a resource that effectively integrates a vast amount of transcriptomic profiling data to comprehensively explore cancer tissue heterogeneity and the tumor microenvironment. In this context, we developed the Single-cell and Spatially-resolved Cancer Resources (SCAR) database, a combined tumor spatial and single-cell transcriptomic platform, which is freely accessible at http://8.142.154.29/SCAR2023 or http://scaratlas.com. SCAR contains spatial transcriptomic data from 21 tumor tissues and single-cell transcriptomic data from 11 301 352 cells encompassing 395 cancer subtypes and covering a wide variety of tissues, organoids, and cell lines. This resource offers diverse functional modules to address key cancer research questions at multiple levels, including the screening of tumor cell types, metabolic features, cell communication and gene expression patterns within the tumor microenvironment. Moreover, SCAR enables the analysis of biomarker expression patterns and cell developmental trajectories. SCAR also provides a comprehensive analysis of multi-dimensional datasets based on 34 state-of-the-art omics techniques, serving as an essential tool for in-depth mining and understanding of cell heterogeneity and spatial location. The implications of this resource extend to both cancer biology research and cancer immunotherapy development.

Machine learning based longitudinal virtual diagnostics at SwissFEL

The bunch length in a linac driven Free Electron Laser (FEL) is a major parameter to be characterized to optimize the final accelerator performance. In linear machines, this observable is typically determined from the beam imaged on a screen located downstream of a Transverse Deflecting Structure (TDS) used to impinge a time dependent kick along the longitudinal coordinate of the beam. This measurement is typically performed during the machine setup and only sporadically to check the beam duration, but it cannot be continuously repeated because it is time consuming and invasive. A non-invasive method to determine the electron bunch length has already been presented in the past. This method is based on the analysis of the synchrotron radiation light spot emitted by the bunch passing through a magnetic chicane, provided that the energy chirp impinged on the bunch by the upstream radio frequency structures is known. In order to overcome a systematic discrepancy affecting the synchrotron radiation monitor based results compared to the absolute TDS based ones, we implemented and optimized a machine learning approach to predict the bunch length downstream of the two SwissFEL compression stages-from about 10 fs up to about 2 ps-as well as the beam longitudinal profile at the first one.

The subfamily Xerocomoideae (Boletaceae, Boletales) in China

Xerocomoideae is an ecologically and economically important Boletaceae subfamily (Boletales) comprising 10 genera. Although many studies have focused on Xerocomoideae in China, the diversity, taxonomy and molecular phylogeny still remained incompletely understood. In the present study, taxonomic and phylogenetic studies on Chinese species of Xerocomoideae were carried out by morphological examinations and molecular phylogenetic analyses. Eight genera in Xerocomoideae, viz. Aureoboletus, Boletellus, Heimioporus, Hemileccinum, Hourangia, Phylloporus, Pulchroboletus, and Xerocomus were confirmed to be distributed in China; 97 species of the subfamily were accepted as being distributed in China; one ambiguous taxon was tentatively named Bol. aff. putuoensis; two synonyms, viz. A. marroninus and P. dimorphus were defined. Among the Chinese accepted species, 13 were newly described, viz. A. albipes, A. conicus, A. ornatipes, Bol. erythrolepis, Bol. rubidus, Bol. sinochrysenteroides, Bol. subglobosus, Bol. zenghuoxingii, H. squamipes, P. hainanensis, Pul. erubescens, X. albotomentosus, and X. fuscatus, 36 known species were redescribed, and the other 48 species were reviewed. Keys to accepted species of Aureoboletus, Boletellus, Heimioporus, Hemileccinum, Hourangia, Phylloporus, and Xerocomus in China were also provided. Taxonomic novelties: New species: Aureoboletus albipes N.K. Zeng, Xu Zhang & Zhi Q. Liang, A. conicus N.K. Zeng, Xu Zhang & Zhi Q. Liang, A. ornatipes N.K. Zeng, Xu Zhang & Zhi Q. Liang, Boletellus erythrolepis N.K. Zeng, R. Xue, S. Jiang & Zhi Q. Liang, Bol. rubidus N.K. Zeng, R. Xue, Y.J. Hao & Zhi Q. Liang, Bol. sinochrysenteroides N.K. Zeng, R. Xue & Kuan Zhao, Bol. subglobosus N.K. Zeng, R. Xue, S. Jiang & Zhi Q. Liang, Bol. zenghuoxingii N.K. Zeng, R. Xue, S. Jiang & Zhi Q. Liang, Hemileccinum squamipes N.K. Zeng, Chang Xu & Zhi Q. Liang, Phylloporus hainanensis N.K. Zeng, L.L. Wu, & Zhi Q. Liang, Pulchroboletus erubescens N.K. Zeng, Chang Xu & Zhi Q. Liang, Xerocomus albotomentosus N.K. Zeng, H.J. Xie, Chang Xu & Zhi Q. Liang, and X. fuscatus N.K. Zeng, H.J. Xie, Chang Xu & Zhi Q. Liang. Citation: Xue R, Zhang X, Xu C, Xie HJ, Wu LL, Wang Y, Tang LP, Hao YJ, Zhao K, Jiang S, Li Y, Yang YY, Li Z, Liang ZQ, Zeng NK (2023). The subfamily Xerocomoideae (Boletaceae, Boletales) in China. Studies in Mycology 106: 95-197. doi: 10.3114/sim.2022.106.03.

Th1 cells inducing IFNγ response improves immunotherapy efficacy in gastric cancer

Objective

Cancer immunotherapy has made remarkable advances in recent years, but its effectiveness in treating gastric cancer is often limited by the complexity of the tumor microenvironment and the lack of effective biomarkers. This study aimed to identify effective biomarkers for immunotherapy treatment by characterizing the tumor microenvironment.

Methods

We retrieved the RNA-seq data from gastric cancer patients treated with the programmed death 1 (PD-1) blockade pembrolizumab. Differentially expressed genes associated with clinical outcomes were identified and further analyzed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Gene signature scores were calculated by single sample Gene Set Enrichment Analysis (ssGSEA). The infiltration levels of immune cells were quantified using the xCell website. Cell type enrichment analysis was performed to compare treatment response and non-response groups, and regression analysis was used to investigate the relationship between interferon gamma (IFNγ) immune response and immune cell infiltration. Biomarkers were identified using least absolute shrinkage and selection operator (LASSO) analysis.

Results

Compared to normal tissues, cytokine activity and interleukin-6 production were highly activated in gastric tumors. Responders to pembrolizumab showed significantly up-regulated expression of IFNγ response-related genes. Cell type enrichment analysis revealed that Th1 cells were significantly enriched in the tumor microenvironment of responders. Regression analysis indicated that Th1 cells induced IFNγ response more efficiently than other cell types. Using signatures of Th1 cells, stromal cells and IFNγ response, a set of eight genes were identified that effectively predicted the efficacy of immunotherapy treatment and patient prognosis.

Conclusions

Th1 cells promote therapeutic efficacy of PD-1 blockade by promoting IFNγ immune response in gastric cancer. The identified biomarkers have the potential to improve the effectiveness of immunotherapy treatment for gastric cancer patients.

Intratumoral erythroblastic islands restrain anti-tumor immunity in hepatoblastoma

Erythroblastic islands (EBIs) are the specialized structures for erythropoiesis, but they have never been found functional in tumors. As the most common pediatric liver malignancy, hepatoblastoma (HB) requires more effective and safer therapies to prevent progression and the lifelong impact of complications on young children. However, developing such therapies is impeded by a lack of comprehensive understanding of the tumor microenvironment. By single-cell RNA sequencing of 13 treatment-naive HB patients, we discover an immune landscape characterized by aberrant accumulation of EBIs, formed by VCAM1⁺ macrophages and erythroid cells, which is inversely correlated with survival of HB. Erythroid cells inhibit the function of dendritic cells (DCs) via the LGALS9/TIM3 axis, leading to impaired anti-tumor T cell immune responses. Encouragingly, TIM3 blockades relieve the inhibitory effect of erythroid cells on DCs. Our study provides an immune evasion mechanism mediated by intratumoral EBIs and proposes TIM3 as a promising therapeutic target for HB.

Liver tumour immune microenvironment subtypes and neutrophil heterogeneity

The heterogeneity of the tumour immune microenvironment (TIME), organized by various immune and stromal cells, is a major contributing factor of tumour metastasis, relapse and drug resistance^1-3, but how different TIME subtypes are connected to the clinical relevance in liver cancer remains unclear. Here we performed single-cell RNA-sequencing (scRNA-seq) analysis of 189 samples collected from 124 patients and 8 mice with liver cancer. With more than 1 million cells analysed, we stratified patients into five TIME subtypes, including immune activation, immune suppression mediated by myeloid or stromal cells, immune exclusion and immune residence phenotypes. Different TIME subtypes were spatially organized and associated with chemokine networks and genomic features. Notably, tumour-associated neutrophil (TAN) populations enriched in the myeloid-cell-enriched subtype were associated with an unfavourable prognosis. Through in vitro induction of TANs and ex vivo analyses of patient TANs, we showed that CCL4⁺ TANs can recruit macrophages and that PD-L1⁺ TANs can suppress T cell cytotoxicity. Furthermore, scRNA-seq analysis of mouse neutrophil subsets revealed that they are largely conserved with those of humans. In vivo neutrophil depletion in mouse models attenuated tumour progression, confirming the pro-tumour phenotypes of TANs. With this detailed cellular heterogeneity landscape of liver cancer, our study illustrates diverse TIME subtypes, highlights immunosuppressive functions of TANs and sheds light on potential immunotherapies targeting TANs.

Instantaneous 4D micro-particle image velocimetry (µPIV) via multifocal microscopy (MUM)

Multifocal microscopy (MUM), a technique to capture multiple fields of view (FOVs) from distinct axial planes simultaneously and on one camera, was used to perform micro-particle image velocimetry (µPIV) to reconstruct velocity and shear stress fields imposed by a liquid flowing around a cell. A diffraction based multifocal relay was used to capture images from three different planes with 630 nm axial spacing from which the axial positions of the flow-tracing particles were calculated using the image sharpness metric. It was shown that MUM can achieve an accuracy on the calculated velocity of around (0.52 ± 0.19) µm/s. Using fixed cells, MUM imaged the flow perturbations at sub-cellular level, which showed characteristics similar to those observed in the literature. Using live cells as an exemplar, MUM observed the effect of changing cell morphology on the local flow during perfusion. Compared to standard confocal laser scanning microscope, MUM offers a clear advantage in acquisition speed for µPIV (over 300 times faster). This is an important characteristic for rapidly evolving biological systems where there is the necessity to monitor in real time entire volumes to correlate the sample responses to the external forces.

Propofol ameliorates acute postoperative fatigue and promotes glucagon-regulated hepatic gluconeogenesis by activating CREB/PGC-1α and accelerating fatty acids beta-oxidation

Postoperative fatigue (POF) is the most common and long-lasting complication after surgery, which brings heavy burden to individuals and society. Recently, hastening postoperative recovery receives increasing attention, but unfortunately, the mechanisms underlying POF remain unclear. Propofol is a wildly used general anesthetic in clinic, and inspired by the rapid antidepressant effects induced by ketamine at non-anesthetic dose, the present study was undertaken to investigate the anti-fatigue effects and underlying mechanisms of propofol at a non-anesthetic dose in 70% hepatectomy induced POF model in rats. We first showed here that single administration of propofol at 0.1 mg/kg ameliorated acute POF in hepatectomy induced POF rats. Based on metabonomics analysis, we hypothesized that propofol exerted anti-fatigue activity in POF rats by facilitating free fatty acid (FFA) oxidation and gluconeogenesis. We further confirmed that propofol restored the deficit in FFA oxidation and gluconeogenesis in POF rats, as evidenced by the elevated FFA utilization, acetyl coenzyme A content, pyruvic acid content, phosphoenolpyruvic acid content, hepatic glucose output and glycogen storage. Moreover, propofol stimulated glucagon secretion and up-regulated expression of cAMP-response element binding protein (CREB), phosphorylated CREB, peroxlsome prolifeator-activated receptor-γ coactivator-1α (PGC-1α), phosphoenolpyruvate carboxykinade1 and carnitine palmitoltransferase 1A. In summary, our study suggests for the first time that propofol ameliorates acute POF by promoting glucagon-regulated gluconeogenesis via CREB/PGC-1α signaling and accelerating FFA beta-oxidation.

Single-Cell DNA Sequencing Reveals Punctuated and Gradual Clonal Evolution in Hepatocellular Carcinoma

BACKGROUND & AIMS

Copy number alterations (CNAs), elicited by genome instability, are a major source of intratumor heterogeneity. How CNAs evolve in hepatocellular carcinoma (HCC) remains unknown.

METHODS

We performed single-cell DNA sequencing (scDNA-seq) on 1275 cells isolated from 10 patients with HCC, ploidy-resolved scDNA-seq on 356 cells from 1 additional patient, and single-cell RNA sequencing on 27,344 cells from 3 additional patients. Three statistical fitting models were compared to investigate the CNA accumulation pattern.

RESULTS

Cells in the tumor were categorized into the following 3 subpopulations: euploid, pseudoeuploid, and aneuploid. Our scDNA-seq analysis revealed that CNA accumulation followed a dual-phase copy number evolution model, that is, a punctuated phase followed by a gradual phase. Patients who exhibited prolonged gradual phase showed higher intratumor heterogeneity and worse disease-free survival. Integrating bulk RNA sequencing of 17 patients with HCC, published datasets of 1196 liver tumors, and immunohistochemical staining of 202 HCC tumors, we found that high expression of CAD, a gene involved in pyrimidine synthesis, was correlated with rapid tumorigenesis and reduced survival. The dual-phase copy number evolution model was validated by our single-cell RNA sequencing data and published scDNA-seq datasets of other cancer types. Furthermore, ploidy-resolved scDNA-seq revealed the common clonal origin of diploid- and polyploid-aneuploid cells, suggesting that polyploid tumor cells were generated by whole genome doubling of diploid tumor cells.

CONCLUSIONS

Our work revealed a novel dual-phase copy number evolution model, showed HCC with longer gradual phase was more severe, identified CAD as a promising biomarker for early recurrence of HCC, and supported the diploid origin of polyploid HCC.

IDH Mutation Subgroup Status Associates with Intratumor Heterogeneity and the Tumor Microenvironment in Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is highly heterogeneous. Here, the authors perform exome sequencing and bulk RNA sequencing on 73 tumor regions from 14 ICC patients to portray the multi-faceted intratumor heterogeneity (ITH) landscape of ICC. The authors show that ITH is highly concordant across genomic, transcriptomic, and immune levels. Comparison of these data to 8 published datasets reveals significantly higher degrees of ITH in ICC than hepatocellular carcinoma. Remarkably, the authors find that high-ITH tumors highly overlap with the IDH (isocitrate dehydrogenase)-mutant subgroup (IDH-SG), comprising of IDH-mutated tumors and IDH-like tumors, that is, those IDH-wildtype tumors that exhibit similar molecular profiles to the IDH-mutated ones. Furthermore, IDH-SG exhibits less T cell infiltration and lower T cell cytotoxicity, indicating a colder tumor microenvironment (TME). The higher ITH and colder TME of IDH-SG are successfully validated by single-cell RNA sequencing on 17 503 cells from 4 patients. Collectively, the study shows that IDH mutant subgroup status, rather than IDH mutation alone, is associated with ITH and the TME of ICC tumors. The results highlight that IDH-like patients may also benefit from IDH targeted therapies and provide important implications for the diagnosis and treatment of ICC.

Sevoflurane impedes the progression of glioma through modulating the circular RNA has_circ_0012129/miR-761/TGIF2 axis

OBJECTIVE

Glioma is a highly aggressive and lethal brain tumor. Anesthetics have been shown to have important effects on the biological characteristics of cancer cells. Nevertheless, the molecular mechanism of anesthetic-mediated glioma cells progression remains unclear.

MATERIALS AND METHODS

Sevoflurane (sev) was employed to treat glioma cells. The biological characteristics (viability, colony formation, apoptosis, cell cycle, migration, and invasion) of glioma cells were determined via Cell Counting Kit-8 (CCK-8), cell colony formation, flow cytometry, PI cytometry, or transwell assays. The protein levels of Cell Cycle Dependent Kinase (CDK) 2, CDK4, E-cadherin, N-cadherin, Vimentin, and Transforming Growth Factor Beta (TGFB) induced factor homeobox 2 (TGIF2) were assessed through Western blot analysis. Glucose consumption and lactate production were measured using special commercial kits. The expression of circular RNA has_circ_0012129 (circ_0012129) and miR-761 was detected via quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between circ_0012129 or TGIF2 and miR-761 was verified with Dual-Luciferase reporter assay. Sevoflurane-mediated molecular mechanisms have been confirmed via xenograft assay.

RESULTS

Sevoflurane suppressed viability, colony formation, cell cycle, migration, and invasion and promoted apoptosis of glioma cells in vitro, and impeded tumor growth in vivo. Circ_0012129 and TGIF2 were downregulated and miR-761 was upregulated in sevoflurane-treated glioma cells. Circ_0012129 elevation abolished sevoflurane-mediated biological characteristics of glioma cells. MiR-761 served as target for circ_0012129 and miR-761 targeted TGIF2. Moreover, both miR-761 overexpression and TGIF2 suppression restored circ_0012129 enhancement-mediated biological characteristics of sevoflurane-treated glioma cells.

CONCLUSIONS

Sevoflurane mediated the progression of glioma via regulating the circ_0012129/miR-761/TGIF2 axis.

Effect of NT-3 on repair of spinal cord injury through the MAPK signaling pathway

OBJECTIVE

The aim of this study was to explore the effect of neurotrophin-3 (NT-3) on the repair of spinal cord injury (SCI) through the mitogen-activated protein kinase (MAPK) signaling pathway.

MATERIALS AND METHODS

The rat model of SCI was first successfully established using the impactor (SCI group). Meanwhile, control group and NT-3 treatment group were set up as well. Basso-Beattie-Bresnahan (BBB) score was given and blood, and spinal cord tissues were collected from rats. Subsequently, serum indexes were detected, including glucose (Glu), creatinine (Cr), K+, Na+, the content of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-β (TNF-β), and the level of myeloperoxidase (MPO). Moreover, the morphological changes were observed via hematoxylin-eosin (HE) staining. The gene and protein expressions of glial fibrillary acidic protein (GFAP) and MAPK were determined through Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Western blotting, respectively. Furthermore, the effect of the MAPK signaling pathway on SCI was comprehensively observed.

RESULTS

In SCI group, the rats could not crawl autonomously with the loss of motor function and paraplegia. Meanwhile, the levels of Glu, Cr, Na+, IL-6, IL-1β, TNF-β, and MPO were all significantly up-regulated. According to the results of HE staining, spinal nerve fibers disappeared with significant syringomyelia in SCI group. Meanwhile, the aggregation of nerve fibers was observed without apparent tissue bleeding, edema, and cell deformation in NT-3 group. QRT-PCR results demonstrated that SCI group showed remarkably higher levels of GFAP, MAPK, and c-Jun N-terminal kinase (JNK) (p<0.05), while it showed a markedly lower level of ERK2 than NT-3 group (p<0.05). In NT-3 group, the protein expression of MAPK in myocardial tissues was remarkably lower than that of SCI group (p<0.05).

CONCLUSIONS

NT-3 can inhibit the MAPK signaling pathway, thereby promoting the repair of SCI.

Somatic mutation landscape reveals differential variability of cell-of-origin for primary liver cancer

Primary liver tissue cancer types are renowned to display a consistent increase in global disease burden and mortality, thus needing more effective diagnostics and treatments. Yet, integrative research efforts to identify cell-of-origin for these cancers by utilizing human specimen data were poorly established. To this end, we analyzed previously published whole-genome sequencing data for 384 tumor and progenitor tissues along with 423 publicly available normal tissue epigenomic features and single cell RNA-seq data from human livers to assess correlation patterns and extended this information to conduct in-silico prediction of the cell-of-origin for primary liver cancer subtypes. Despite mixed histological features, the cell-of-origin for mixed hepatocellular carcinoma/intrahepatic cholangiocarcinoma subtype was predominantly predicted to be hepatocytic origin. Individual sample-level predictions also revealed hepatocytes as one of the major predicted cell-of-origin for intrahepatic cholangiocarcinoma, thus implying trans-differentiation process during cancer progression. Additional analyses on the whole genome sequencing data of hepatic progenitor cells suggest these cells may not be a direct cell-of-origin for liver cancers. These results provide novel insights on the nature and potential contributors of cell-of-origins for primary liver cancers.

Efficacy and immunogenicity of a live L. acidophilus expressing SAD epitope of transmissible gastroenteritis virus as an oral vaccine

Transmissible gastroenteritis virus (TGEV) causes great economic loss to swine industry worldwide. Vaccination is an important method to control the TGEV infection. In this study, a TGEV oral vaccine was generated by transferring a eukaryotic expression recombinant plasmid carrying the SAD (A and D antigenic sites of the S protein) epitope of TGEV into a swine-origin Lactobacillus acidophilus (L. acidophilus). In orally immunized BALB/c mice, the TGEV L. acidophilus oral vaccine induced significantly higher level of SIgA antibodies specific to TGEV compared with the mice immunized with a commercial inactivated TGEV vaccine and similar levels of IgG specific to TGEV as the inactivated vaccine. Furthermore, the TGEV L. acidophilus oral vaccine induced higher levels of IFN-γ, which suggested that the vaccine was able to induce immune response. In brief, this novel TGEV L. acidophilus oral vaccine could induce high levels of both mucosal and humoral immune responses, which has a potential to be used in the pig industries in the future. Keywords: transmissible gastroenteritis virus (TGEV); live L. acidophilus oral vaccine; SIgA antibody; IgG antibody; IFN-γ; IL-4.

[Prevalence of silicosis among Xiangyu railway construction workers in Nanchong from 2008-2007]

Objective: To analyze the prevalence of silicosis in the militias with contribution to the former Xiangyu Railway construction in Nanchong, China, from 2008 to 2017, and to provide a scientific basis for the future development of pneumoconiosis prevention and control strategies based on the current status. Methods: A database was established for the data of 11863 militias with contribution to the former Xiangyu Railway construction in Nanchong, China, who attended our hospital from 2008 to 2017, including 11485 males (96.81%) and 378 females (3.19%). The SPSS 17.0 software was used to analyze the differences in the detection rate of silicosis between militias with different sexes or those with different job types, as well as the age, length of service, and regional distribution of patients. Results: Of the 11863 railway militias in Nanchong, 3169 (26.71%) were diagnosed with silicosis, including 2761 (87.12%) in stage I, 359 (11.33%) in stage II, and 49 (1.55%) in stage III; the males had a significantly higher detection rate of silicosis than the females (χ(2)=64.496, P<0.05); there was a significant difference in the detection rate of silicosis between the militias with different job types (χ(2)=856.839, P<0.05). There were significant differences in the mean age of diagnosis and the mean length of service between the patients with different stages of silicosis (F=4.944, P<0.05; F=3.174, P<0.05). There was a significant difference in the number of militia patients with silicosis between different areas of Nanchong (χ(2)=843.330, P<0.05). Conclusion: The prevalence of silicosis is relatively high among the militias with contribution to the former Xiangyu Railway. It is necessary to strengthen the occupational health monitoring of patients, actively treat and prevent complications, and improve the quality of life of patients.

Genomic and Transcriptomic Profiling of Combined Hepatocellular and Intrahepatic Cholangiocarcinoma Reveals Distinct Molecular Subtypes

We performed genomic and transcriptomic sequencing of 133 combined hepatocellular and intrahepatic cholangiocarcinoma (cHCC-ICC) cases, including separate, combined, and mixed subtypes. Integrative comparison of cHCC-ICC with hepatocellular carcinoma and intrahepatic cholangiocarcinoma revealed that combined and mixed type cHCC-ICCs are distinct subtypes with different clinical and molecular features. Integrating laser microdissection, cancer cell fraction analysis, and single nucleus sequencing, we revealed both mono- and multiclonal origins in the separate type cHCC-ICCs, whereas combined and mixed type cHCC-ICCs were all monoclonal origin. Notably, cHCC-ICCs showed significantly higher expression of Nestin, suggesting Nestin may serve as a biomarker for diagnosing cHCC-ICC. Our results provide important biological and clinical insights into cHCC-ICC.

[Effects of chronic intermittent hypoxia on hepatic function and protective mechanism of adiponectin in rats]

Objective: To explore the effect of chronic intermittent hypoxia (CIH) on rats hepatic function, and the protective mechanism of adiponectin (Ad). Methods: Sixty healthy male wistar rats were randomly divided into 4 groups: normal control (NC), NC+ Ad, CIH, and CIH+ Ad groups with 15 rats in each. The rats in CIH and CIH+ Ad groups were exposed to an intermittent hypoxic chamber 8 hours per day for 4 months. Meanwhile, the rats in both the NC and NC + Ad groups were housed with normal pressure air. The rats in the NC+ Ad and CIH+ Ad groups were additionally treated with an intravenous injection of Ad (10 μg), twice a week for 4 months. At the end of experiment, comparison among groups was made about plasma levels of aspartate amino transferase (AST), alanine amino transferase (ALT), degrees of endoplasmic reticulum stress (ERS) and mitochondrium associated cellular apoptosis. Results: No significant difference was detected in all items between NC and NC+ Ad groups (all P>0.05). Plasma hepatic enzyme levels of AST and ALT were significantly higher in CIH group [(319±21) and (113±9) U/L] than those in NC group [(178±19) and (51±9) U/L] and NC+ Ad group [(175±16) and (52±8) U/L] (all P<0.05). Compared NC with NC+ Ad group, there was more remarkable ERS and mitochondrial injury associated cellular apoptosis in hepatic tissues of CIH group. Such pathological changes were less obvious in CIH+ Ad group than in CIH group (all P<0.05). Conclusion: CIH can induce hepatic injury in rats, while Ad supplement may play a protective role possibly through inhibition of ERS and associated pathways of cellular apoptosis.

H9N2 influenza virus isolated from minks has enhanced virulence in mice

H9N2 is one of the major subtypes of influenza virus circulating in poultry in China, which has a wide host range from bird to mammals. Two H9N2 viruses were isolated from one mink farm in 2014. Phylogenetic analysis showed that internal genes of the H9N2 viruses have close relationship with those of H7N9 viruses. Interestingly, two H9N2 were separated in phylogenetic trees, indicating that they are introduced to this mink farm in two independent events. And further mice studies showed that one H9N2 caused obvious weight loss and 20% mortality in infected mice, while another virus did not cause any clinical sign in mice infected at the same dose. Genetic analysis indicated that the virulent H9N2 contain a natural mutation at 701N in PB2 protein, which was reported to contribute to mammalian adaptation. However, such substitution is absent in the H9N2 avirulent to mice. Circulation of H9N2 in mink may drive the virus to adapt mammals; continual surveillance of influenza virus in mink was warranted.

Aggravation of spinal cord compromise following new osteoporotic vertebral compression fracture prevented by teriparatide in patients with surgical contraindications

Patients with spinal cord deficits following new unstable osteoporotic compression fracture and surgical contraindications were considered to receive conservative treatment. Teriparatide was better than alendronate at improving bone mineral density and bone turnover parameters, as well as preventing aggravation of spinal cord compromise.

INTRODUCTION

This study compared the preventive effects of teriparatide and alendronate on aggravation of spinal cord compromise following new unstable osteoporotic vertebral compression fracture (OVCF) in patients with surgical contraindications.

METHODS

This was a 12-month, randomized, open-label study of teriparatide versus alendronate in 49 patients with new unstable OVCF and surgical contraindications. Neurological function was evaluated using modified Japanese Orthopedic Association (mJOA) score (11-point scale, the maximum score of 11 implies normalcy). Visual analog scale (VAS) scores, kyphotic angles, anterior-border heights and diameters of the spinal canal of the fractured vertebrae, any incident of new OVCFs (onset of OVCF during follow-up), spine bone mineral density (BMD), and serum markers of bone resorption and bone formation were also examined at baseline and 1, 3, 6, and 12 months after initiation of the medication regimen.

RESULTS

At 12 months, mean mJOA score had improved in the teriparatide group and decreased in the alendronate group. Mean concentrations of bone formation and bone resorption biomarkers, mean spine BMD, and mean anterior-border height and spinal canal diameter of the fractured vertebrae were significantly greater in the teriparatide group than in the alendronate group. Mean VAS score, mean kyphotic angle of the fractured vertebrae, and incidence of new OVCFs were significantly smaller in the teriparatide group than in the alendronate group.

CONCLUSIONS

In patients with neurological deficits following new unstable OVCF and with surgical contraindications, teriparatide was better than alendronate at improving the BMD and the bone turnover parameters, as well as preventing aggravation of spinal cord compromise.

Variable Intra-Tumor Genomic Heterogeneity of Multiple Lesions in Patients With Hepatocellular Carcinoma

BACKGROUND & AIMS

Many patients with hepatocellular carcinoma (HCC) have multiple lesions (primary tumors, intrahepatic metastases, multiple occurrences, satellite nodules, and tumor thrombi); these have been associated with a poor prognosis and tumor recurrence after surgery. We investigated the clonal relationship among these lesions on the basis of genetic features.

METHODS

We collected 43 lesions and 10 matched control samples (blood or nontumorous liver) from 10 patients with hepatitis B virus-associated HCC treated at Tianjin Cancer Hospital (China) from January 2013 through May 2014. We performed exome and low-depth, whole-genome sequencing on these samples. Genomic aberrations, including somatic mutations and copy number variations, were identified using germline DNA as control. We compared the genetic features of different lesions from each patient and constructed phylogenetic trees to depict their evolutionary histories.

RESULTS

In each patient, mutations shared by all the lesions were called ubiquitous mutations. The percentage of ubiquitous mutations varied from 8% to 97% among patients, indicating variation in the extent of intratumor heterogeneity. Branched evolution was evident, with somatic mutations, hepatitis B virus integrations, and copy number variations identified on both the trunks and branches of the phylogenetic trees. Intrahepatic metastases and tumor thrombi contained some, but not all, of the mutations detected in their matched primary lesions. By contrast, satellite nodules shared approximately 90% of mutations detected in primary lesions. In a patient with multicentric tumors, 6 lesions were assigned to 2 distinct groups, based on significant differences in genetic features. In another patient with combined hepatocellular and intrahepatic cholangiocarcinoma, the physically separate HCC and cholangiocarcinoma lesions shared 102 mutations.

CONCLUSIONS

The extent of intratumor heterogeneity varies considerably among patients with HCC. Therefore, sequence analysis of a single lesion cannot completely characterize the genomic features of HCC in some patients. Genomic comparisons of multiple lesions associated with HCCs will provide important information on the genetic changes associated with tumor progression.

Role of mitophagy regulated by Parkin/DJ-1 in remote ischemic postconditioning-induced mitigation of focal cerebral ischemia-reperfusion

OBJECTIVE

We evaluated the role of mitophagy controlled by Parkin/DJ-1 in remote ischemic post conditioning-induced mitigation of focal cerebral ischemia-reperfusion (I/R) injury in rats.

MATERIALS AND METHODS

Ninety adult male rats were randomly assigned into 5 groups including a sham operation group (S) and ischemia-reperfusion group (I/R). Focal cerebral I/R was induced by right middle cerebral artery occlusion (MCAO). I/R+remote ischemic postconditioning (I/R+RIPoC), I/R+RIPoC+ mitophagy inhibitor Mdivi-1 (I/R+RIPoC+M), and I/R+RIPoC+ normal saline (I/R+RIPoC+NS) groups all received 3 cycles of 10 minutes reperfusion followed by 10 minutes ischemia in bilateral femoral arteries at the beginning of cerebral reperfusion. I/R+RIPoC+M received mitochondrial division inhibitor (Mdivi-1) before ischemia and after 24h of reperfusion, neurological deficit scores (NDSs) were measured and rats were then sacrificed. Brain was removed and size of the infarct was determined. Apoptosis index and LC3-II/I ratio, Parkin/DJ-1 proteins expression, SOD activity, MDA and 15-F2t-Isoprostane content in cerebral ischemic penumbra were studied. Linear correlation between Parkin/DJ-1 proteins expression and LC3-II/I ratio and cerebral infarct size were analyzed.

RESULTS

In experimental groups the NDSs, percentage of cerebral infarct size, apoptosis index, LC3-II/I ratio, MDA and 15-F2t-Isoprostane content significantly increased and Parkin/DJ-1 proteins were up-regulated (p<0.05). In I/R+RIPoC and I/R+RIPoC+NS groups, NDSs, percentage of cerebral infarct size, apoptosis index, MDA and 15-F2t-Isoprostane content decreased significantly while LC3-II/I ratio and SOD activity increased compared to I/R group. Parkin/DJ-1 proteins were up-regulated in I/R+RIPoC, I/R+RIPoC+NS and I/R+RIPoC+M groups (p<0.05). LC3-II/I ratio and SOD activity significantly decreased (p<0.05). Parkin/DJ-1 proteins expression didn't changed in I/R+RIPoC+M group (p>0.05). The Parkin/DJ-1 proteins expression were positively correlated with LC3-II/I ratio, and negatively correlated with cerebral infarct size (p<0.05).

CONCLUSIONS

Remote Ischemic Post Conditioning (RIPoC) promoted the mitophagy via up-regulation of Parkin/DJ-1 proteins expression and inhibiting the oxidative stress responses, thus mitigating focal cerebral I/R injury in rats.

A Delicate Nanoscale Motor Made by Nature-The Bacterial Flagellar Motor

The bacterial flagellar motor (BFM) is a molecular complex ca. 45 nm in diameter that rotates the propeller that makes nearly all bacteria swim. The motor self-assembles out of ca. 20 different proteins and can not only rotate at up to 50 000 rpm, but can also switch rotational direction in milliseconds and navigate its environment to maneuver, on average, towards regions of greater benefit. The BFM is a pinnacle of evolution that informs and inspires the design of novel nanotechnology in the new era of synthetic biology.

Development of novel microsatellite markers in the Korean rockfish Sebastes schlegeli

The Korean rockfish Sebastes schlegeli is a valuable recreational and commercial fish in China, and is cultured in land-based tanks and net cages. Fifteen microsatellite markers were developed for this species, and their polymorphisms were examined in a population. The allele number of the 15 markers ranged from 2 to 13, with an average of 5.933 per locus. The observed and expected heterozygosity values ranged from 0.063 to 0.938 (averaging 0.585), and 0.062 to 0.908 (averaging 0.642), respectively. Thirteen loci were at Hardy-Weinberg equilibrium (HWE), whereas the other two significantly deviated from the HWE after a Bonferroni's correction. No significant linkage disequilibrium was detected between the comparisons of these loci. These markers are useful for studies of population genetics, linkage mapping, and other relevant studies on S. schlegeli.

Resistance of transgenic silkworm to BmNPV could be improved by silencing ie-1 and lef-1 genes

RNA interference (RNAi)-mediated viral inhibition has been used in several organisms for improving viral resistance. In the present study, we reported the use of transgenic RNAi in preventing Bombyx mori nucleopolyhedrovirus (BmNPV) multiplication in the transgenic silkworm B. mori. We targeted the BmNPV immediate-early-1 (ie-1) and late expression factor-1 (lef-1) genes in the transiently transfected BmN cells, in the stable transformed BmN cell line and in the transgenic silkworms. We generated four piggyBac-based vectors containing short double-stranded ie-1 RNA (sdsie-1), short double-stranded lef-1 RNA (sdslef-1), long double-stranded ie-1 RNA (ldsie-1) and both sdsie-1 and sdslef-1 (sds-ie1-lef1) expression cassettes. Strong viral repression was observed in the transiently transfected cells and in the stable transformed BmN cells transfected with sds-ie-1, sdslef-1, ldsie-1 or sds-ie-lef. The decrease of ie-1 mRNA level in the sds-ie1-lef1 transiently transfected cells was most obvious among the cells transfected with different vectors. The inhibitory effect of viral multiplication was decreased in a viral dose-dependent manner; the infection ratio of transfected cells for sds-ie-1, sdslef-1, ldsie-1 and sds-ie-lef decreased by 18.83%, 13.73%, 6.93% and 30.63%, respectively, compared with control cells 5 days after infection. We generated transgenic silkworms using transgenic vector piggyantiIE-lef1-neo with sds-ie1-lef1 expression cassette; the fourth instar larvae of transgenic silkworms of generation G5 exhibited stronger resistance to BmNPV, the mortalities for the transgenic silkworms and control silkworms were 60% and 100%, respectively, at 11 days after inoculation with BmNPV (10(6) occlusion bodies per ml). These results suggest that double-stranded RNA expression of essential genes of BmNPV is a feasible method for breeding silkworms with a high antiviral capacity.

Accuracy of vessel-encoded pseudocontinuous arterial spin-labeling in identification of feeding arteries in patients with intracranial arteriovenous malformations

BACKGROUND AND PURPOSE

Identifying feeding arteries of intracranial AVMs is very important for preoperative evaluation. DSA remains the reference standard for diagnosis but is invasive. Our aim was to evaluate the diagnostic accuracy of vessel-encoded pseudocontinuous arterial spin-labeling in identifying feeding arteries of intracranial AVMs by using DSA as the criterion standard.

MATERIALS AND METHODS

Eighteen patients with AVMs were examined with vessel-encoded pseudocontinuous arterial spin-labeling and DSA. Three postlabeling delays (postlabeling delay = 1, 1.3, and 1.6 seconds) were applied in 6 patients, and a single postlabeling delay (1 second) was applied in the remainder. Perfusion-weighted images were decoded into individual vascular territories with standard and relative tagging efficiencies, respectively. The supply fraction of each feeding artery to the AVM was calculated. The within-subject ANOVA was applied to compare supply fractions acquired across 3 postlabeling delays. Receiver operating characteristic analysis curves were calculated to evaluate the diagnostic accuracy of vessel-encoded pseudocontinuous arterial spin-labeling for identifying the feeding arteries of AVMs.

RESULTS

There were no significant differences in supply fractions of the 3 major arteries to AVMs acquired with 3 postlabeling delays (P > .05). For vessel-encoded pseudocontinuous arterial spin-labeling with standard labeling efficiencies, the area under the receiver operating characteristic analysis curve was 0.942. The optimal cutoff of the supply fraction for identifying feeding arteries was 15.17%, and the resulting sensitivity and specificity were 84.62% and 93.33%, respectively. For vessel-encoded pseudocontinuous arterial spin-labeling with relative labeling efficiencies, the area under the receiver operating characteristic analysis curve was 0.957. The optimal cutoff of the supply fraction was 11.73%, which yielded an 89.74% sensitivity and 93.33% specificity.

CONCLUSIONS

The contribution fraction of each feeding artery of the AVM can be reliably estimated by using vessel-encoded pseudocontinuous arterial spin-labeling. Vessel-encoded pseudocontinuous arterial spin-labeling with either standard or relative labeling efficiencies offers a high level of diagnostic accuracy compared with DSA for identifying feeding arteries.

MR evaluation of the glomerular homing of magnetically labeled mesenchymal stem cells in a rat model of nephropathy

PURPOSE

To assess renal glomerular homing of intravenously injected superparamagnetic iron oxide (SPIO)-labeled mesenchymal stem cells (MSCs) at in vivo and ex vivo magnetic resonance (MR) imaging in an experimental rat model of mesangiolysis.

MATERIALS AND METHODS

Animal procedures were performed in accordance with protocols approved by Institutional Animal Care and Use Committee. Fourteen rats were divided into two groups: one pathologic (n = 10), with persistent mesangiolysis following simultaneous injection of OX-7 monoclonal antibody and puromycin aminonucleoside in which 10(7) SPIO- and DiI-labeled MSCs were injected, and one control (n = 4). In vivo and ex vivo MR imaging examinations were performed with 4.7- and 9.4-T spectrometers, respectively, and T2*-weighted sequences. In vivo signal intensity variations were measured in the liver and kidney before and 6 days after MSC injection. Intrarenal signal intensity variations were correlated with histopathologic data by means of colocalization of DiI fluorescence, alpha-actin, and Prussian blue stain-positive cells. Histologic differences between the glomerular homing of MSCs in different kidney portions were correlated to the areas of MR signal intensity decrease with nonparametric statistical tests.

RESULTS

On in vivo images, signal intensity measurements of pathologic kidneys following MSC injection did not show any signal intensity decrease (P = .7), whereas a 34% +/- 14 (mean +/- standard deviation) signal intensity decrease was observed in the liver (P < .01), where a substantial number of labeled cells were trapped. On ex vivo images, pathologic kidneys showed focal cortical (glomerular) areas of signal intensity loss, which was absent in controls. The areas of low signal intensity correlated well with alpha-actin and Prussian blue stain- and DiI-positive areas (P < .01), which indicates that MSCs specifically home to injured tissue. No MSCs were detected in the kidneys of control animals.

CONCLUSION

Intravenously injected MSCs specifically home to focal areas of glomerular damage and can be detected at ex vivo MR imaging.

Computer simulation of the distribution of aluminum speciation in soil solutions in equilibrium with the mineral phase imogolite

The speciation of aluminum (Al) is a critical issue when evaluating the environmental and biological significance of elevated Al concentrations in soil solutions caused by acidic precipitation. Numerous studies have revealed that, with increased concentrations of silica acid in soil, the activity of Al species in soil solutions is greatly modified by SiO(4)(2-). However, thus far there has been little thorough theoretical modeling of this subject. This paper reports a computer simulation of the distribution of Al speciation in soil solutions in equilibrium with the mineral phase imogolite based on a chemical equilibrium calculation. The unique characteristic associated with imogolite reported by previous researchers can be explained theoretically by the proposed model. The dissolved silica has a remarkable influence on Al speciation: increasing concentrations of silica acid may effectively inhibit the formation of polymeric alumino-hydroxo species, and, furthermore, detoxify Al toxicity to plants.

Rapid three-dimensional diffusion MRI facilitates the study of acute stroke in mice

MRI studies using mouse brain models of ischemia are becoming a valuable tool for understanding the mechanism of stroke, since transgenic models are now available. However, the small size of the mouse brain and the surgical complexity of creating ischemia in mice make it technically challenging to obtain high-quality MRI data. Therefore, there are few reports of MRI studies in murine cerebral ischemia. In this project a newly developed rapid 3D diffusion-weighted imaging (DWI) technique was applied to study experimental stroke in a mouse model of reversible middle cerebral artery occlusion (MCAO). Ischemic volumes were successfully delineated using this 3D whole-brain imaging technique with high spatial (0.34 x 0.5 x 1.0 mm(3) before zero-filling) and temporal (7 min) resolution. The 3D observation revealed the characteristic evolution of stroke after transient MCAO. There was a temporarily high diffusion constant in the cortex during early reperfusion, followed by a secondary energy failure in the cortex and caudate-putamen at 6 and 21 h of reperfusion. Magn Reson Med 46:183-188, 2001.

[Analysis and expression of Hyphantria cunea nuclear polyhedrosis virus sod gene]

The sequencing results indicated that Hyphantria cunea nuclear polyhedrosis virus (HcNPV) sod gene open reading frame of 456 nt encoding protein of 151 amino acid, was identified to that of Bombyx mori nuclear polyhedrosis virus (BmNPV), and exhibited 97.2% homology at nucletde level to that of Autographa californica nuclear polyhedrosis virus (AcNPV), three amino acid residues difference in amino acid level with AcNPV sod. The essential amino acid residues for the construction and active could be detected in HcNPV sod. Activity of the SOD is 147.09 U per milliliter E. coli.

In vivo three-dimensional reconstruction of rat brain axonal projections by diffusion tensor imaging

The in situ assessment of axonal projections of the brain has been severely limited by the lack of noninvasive techniques to study this type of anatomy. We show here that in vivo three-dimensional (3D) reconstruction of axonal projections can be achieved using a rapid 3D high-resolution diffusion-weighted imaging technique combined with a recently designed fiber reconstruction algorithm. As a first example, neuronal pathways in the rat brain were probed. Eight well-known fiber projections; genu and splenium of corpus callosum, internal and external capsule, fimbria, anterior commissure, optic tract, and stria terminalis were tracked and shown to be in agreement with the location of these known axonal projections. The experiment took 2 hr and shorter times should be possible in the clinical situation. By combining anisotropy information with fiber tracking, the anisotropy of individual projections was also documented. Magn Reson Med 42:1123-1127, 1999.

In vivo three-dimensional reconstruction of rat brain axonal projections by diffusion tensor imaging

The in situ assessment of axonal projections of the brain has been severely limited by the lack of noninvasive techniques to study this type of anatomy. We show here that in vivo three-dimensional (3D) reconstruction of axonal projections can be achieved using a rapid 3D high-resolution diffusion-weighted imaging technique combined with a recently designed fiber reconstruction algorithm. As a first example, neuronal pathways in the rat brain were probed. Eight well-known fiber projections; genu and splenium of corpus callosum, internal and external capsule, fimbria, anterior commissure, optic tract, and stria terminalis were tracked and shown to be in agreement with the location of these known axonal projections. The experiment took 2 hr and shorter times should be possible in the clinical situation. By combining anisotropy information with fiber tracking, the anisotropy of individual projections was also documented. Magn Reson Med 42:1123-1127, 1999.

Delayed reduction of tissue water diffusion after myocardial ischemia

The apparent diffusion coefficient (ADC) of water after regional myocardial ischemia was measured in isolated, perfused rabbit hearts by using magnetic resonance imaging (MRI) techniques. After ligation of the left anterior descending coronary artery, the ADC of the nonperfused region showed a gradual but significant decreasing trend over time, whereas that of the normally perfused myocardium remained constant. Morphological analysis revealed that the ADC decrease reflected the expansion of a subregion of reduced ADC within the nonperfused myocardium. The dynamics of the diffusion change and the morphological progression of the affected tissue suggest that the ADC decrease may be linked to the onset of myocardial infarction, which is known to involve myocyte swelling. The ADC reduction provides a potentially valuable MRI tissue-contrast mechanism for noninvasively determining the viability of the ischemic myocardium and assessing the dynamics of acute myocardial infarction.

Amyloid precursor protein metabolism in primary cell cultures of neurons, astrocytes, and microglia

Amyloid precursor protein (APP) gives rise by proteolytic processing to the amyloid beta peptide (A beta) found abundantly in cerebral senile plaques of individuals with Alzheimer's disease. APP is highly expressed in the brain. To assess the source of cerebral A beta, the metabolism of APP was investigated in the major cell types of the newborn rat cerebral cortex by pulse/chase labeling and immunoprecipitation of the APP and APP metabolic fragments. We describe a novel C-terminally truncated APP isoform that appears to be made only in neurons. The synthesis, degradation, and metabolism of APP were quantified by phosphorimaging in neurons, astrocytes, and microglia. The results show that although little APP is metabolized through the amyloidogenic pathways in each of the three cultures, neurons appear to generate more A beta than astrocytes or microglia.

Soluble amyloid beta-protein is a marker of Alzheimer amyloid in brain but not in cerebrospinal fluid

The amyloid beta protein (A beta), a 4 kD fragment of the beta amyloid precursor protein, is deposited as insoluble amyloid in the brain of Alzheimer disease (AD) subjects. Soluble A beta is a normal metabolic product and is present in cerebrospinal fluid. We identified soluble A beta forms of 4kD, 3kD and 3.7kD in AD but not in control brains free of amyloid deposits. All three forms of soluble A beta extend beyond residue 40. Analysis of cerebrospinal fluid from the same subjects confirmed the presence of only 4kD A beta in comparable amounts in AD and controls. The presence of soluble A beta only in brain regions with amyloid suggests they are related. The undetectability of soluble A beta in control brains indicates that it is normally removed or bound to other proteins. Failure of this protective mechanism might cause amyloid formation in AD.

Fatal familial insomnia, a prion disease with a mutation at codon 178 of the prion protein gene

BACKGROUND

We previously described two members of a family affected by an apparently genetically determined fatal disease characterized clinically by progressive insomnia, dysautonomia, and motor signs and characterized pathologically by severe atrophy of the anterior ventral and mediodorsal thalamic nuclei. Five other family members who died of this disease, which we termed "fatal familial insomnia," had broader neuropathologic changes suggesting that fatal familial insomnia could be a prion disease.

METHODS

We used antibodies to prion protein (PrP) to perform dot and Western blot analyses, with and without proteinase K, on brain tissue obtained at autopsy from two patients with fatal familial insomnia, three patients with sporadic Creutzfeldt-Jakob disease, and six control subjects. The coding region of the PrP gene was amplified and sequenced in the samples from the two patients with fatal familial insomnia. Restriction-enzyme analysis was carried out with amplified PrP DNA from 33 members of the kindred.

RESULTS

Protease-resistant PrP was found in both patients with fatal familial insomnia, but the size and number of protease-resistant fragments differed from those in Creutzfeldt-Jakob disease. In the family with fatal familial insomnia, all 4 affected members and 11 of the 29 unaffected members had a point mutation in PrP codon 178 that results in the substitution of asparagine for aspartic acid and elimination of the Tth111 I restriction site. Linkage analysis showed a close relation between the point mutation and the disease (maximal lod score, 3.4 when theta was zero).

CONCLUSIONS

Fatal familial insomnia is a prion disease with a mutation in codon 178 of the PrP gene, but the disease phenotype seems to differ from that of previously described kindreds with the same point mutation.