Identification of Hub Genes and Pathways Associated with CAR-T Cell-Mediated Neurotoxicity in DLBCL

BACKGROUND

Severe neurotoxicity after chimeric antigen receptor T cell (CAR-T) therapy can be a crucial lifethreatening event in diffuse large B-cell lymphoma (DLBCL), and management of those toxicities is still a serious clinical challenge. The underlying mechanisms of CAR-T cell-mediated neurotoxicity remain poorly elucidated because very few studies examine the intact tumor microenvironment before CAR-T cell infusion. Herein, we pur-posed to identify differentially expressed genes (DEGs) related to CAR-T cell-mediated neurotoxicity in the DLBCL microenvironment before CAR-T cell infusion and reveal their potential mechanisms.

METHODS

The mRNA expression profile data of GSE153438 were obtained from the GEO database. The GSE153438 dataset includes 26 samples with non-severe neurotoxicity (grade 0 - 2) and 10 samples with severe neurotoxicity (grade 3 or higher). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) patway enrichment assessment was carried out. We screened the hub gene by protein-protein interaction (PPI) network analysis and Cytoscape software. Gene set enrichment analysis (GSEA) was also analyzed with the GSEA software. Moreover, the predictive value of the hub gene for severe neurotoxicity was evaluated via receiver operating characteristic (ROC) curve analysis.

RESULTS

We identified a total of 25 up-regulated DEGs and 26 downregulated DEGs associated with CAR-T cell-mediated neurotoxicity in the DLBCL microenvironment before CAR-T cell infusion. Results of GO analysis showed that DEGs were mainly enriched in T cell activation, leukocyte cell-cell adhesion, and positive regulation of cell adhesion. The KEGG analysis revealed that DEGs were significantly enriched in T cell receptor signaling pathway, cell adhesion molecules, and Epstein-Barr virus infection. GSEA revealed that the glycolysis pathway was significantly associated with severe neurotoxicity. The top centrality hub gene GZMB was identified from the PPI network. ROC curve analysis showed that GZMB had a potential predictive value for severe neurotoxicity.

CONCLUSIONS

In DLBCL microenvironment before CAR-T cell infusion, we identified T cell activation and glycolysis pathways significantly associated with CAR-T cell-mediated severe neurotoxicity. GZMB might be used as a predictive and therapeutic molecular marker for neurotoxicity. The study suggested that the tumor microenviron-ment before CAR-T cell infusion plays an essential role in the early prediction of neurotoxicity.

Efficacy and safety of tranexamic acid in orthopaedic trauma surgery: a meta-analysis

OBJECTIVE

To systematically review the efficacy and safety of tranexamic acid (TXA) in reducing blood transfusion and total blood loss in patients undergoing orthopaedic trauma surgery.

MATERIALS AND METHODS

A systematic literature search was performed using PubMed, Embase and Cochrane Library databases. The search time was incepted to February 2019. Two reviewers independently screened literature, extracted data, and assessed risk of bias. Then, meta-analysis was performed using RevMan 5.3.

RESULTS

A total of 10 studies were included, with 936 patients. The pooled results indicated that TXA group was superior to control group in the total blood loss [MD=-157.61, 95%CI (-250.09, -65.13), p=0.0008], blood transfusion [OR=0.59, 95%CI (0.43, 0.81), p=0.001], and the wound complications [OR=0.59, 95%CI (0.43, 0.81), p=0.001]. There was no significant difference in risk of thromboembolic events [OR=1.27, 95%CI (0.78, 2.12), p=0.35] and the mortality [OR=0.79, 95%CI (0.35, 1.78), p=0.57] between TXA and control group.

CONCLUSIONS

TXA could effectively reduce blood transfusion, total blood loss, and wound complications in patients undergoing orthopedic trauma surgery. Furthermore, TXA does not significantly increase the incidence of thromboembolic events and mortality. Due to the limited quality of the included studies, more high-quality works are required to verify the above conclusions.

[Efficiency Analysis of EX16+10Y Kit on Detection of the Uygur Population in Xinjiang Province]

OBJECTIVES

To analyse the efficiency of EX16+10Y kit on the forensic detection of the Uygur in Xinjiang province.

METHODS

The blood samples were extracted from 4 620 male individuals of Uygur in Xinjiang province, and amplified by EX16+10Y kit. The typing of amplification products was performed by 3130xl genetic analyzer.

RESULTS

The genotyping graphs of 15 autosomal STR loci and 10 Y-chromosomal STR loci from 4 620 male individuals of Uygur in Xinjiang province were acquired completely. The genotype distribution of 15 autosomal STR loci was consistent with Hardy-Weinberg equilibrium. The heterozygosity, polymorphism information content and discrimination power of STR loci were 0.637-0.838, 0.580-0.860 and 0.811-0.978, respectively. There were 766 haplotypes in 10 Y -chromosomal STR loci.

CONCLUSIONS

The test results of EX16+10Y kit is accurate and trustworthy, which can simultaneously be used for the individual identification and the screening of paternal pedigree in practical work.

Identification of miRNA-mRNA Network Associated with Acute Myeloid Leukemia Survival

Background

Acute myeloid leukemia (AML) is a common hematologic malignancy of adults. The pathophysiological mechanism of AML is not well understood. The purpose of this study was to examine the crucial miRNAs and mRNAs associated with AML survival.

Material/Methods

The full clinical dataset of miRNA and mRNA expression profiling of AML patients was downloaded from The Cancer Genome Atlas database. Univariate Cox regression analysis was performed to obtain those miRNAs and mRNAs associated with AML survival. A miRNA-mRNA interaction network was constructed. The underlying functions of mRNAs were predicted through Kyoto Encyclopedia of Genes and Genomes (KEEG) pathway enrichment. The expression levels of miRNAs and mRNAs were detected by quantitative real-time polymerase chain reaction (qRT-PCR).

Results

Fourteen miRNAs and 830 mRNAs associated with AML survival were identified. Of the 14 miRNAs, hsa-mir-425, hsa-mir-1201, and hsa-mir-1978 were identified as risk factors and the other 11 miRNAs were identified as protective factors of AML survival. For target-genes of miRNAs, GTSF1, RTN4R, and CD44 were the top risk factor target-genes associated with AML survival. An interaction network was constructed that including 607 miRNA-target gene pairs associated with AML survival. Target-genes associated with AML survival were significantly enriched in several pathways including pancreatic secretion, calcium signaling pathway, natural killer cell mediated cytotoxicity, and Alzheimer’s disease. The qRT-PCR results were consistent with our bioinformatics analyses.

Conclusions

The miRNA hsa-mir-425 was identified as the top risk factor miRNA of AML survival and CD44 was identified as one of the top three risk factor target-genes associated with AML survival. Both hsa-mir-425 and CD44 may play key roles in progression and development of AML through calcium signaling pathway and natural killer cell mediated cytotoxicity.

Bacterial Folates Provide an Exogenous Signal for C. elegans Germline Stem Cell Proliferation

Here we describe an in vitro primary culture system for Caenorhabditis elegans germline stem cells. This culture system was used to identify a bacterial folate as a positive regulator of germ cell proliferation. Folates are a family of B-complex vitamins that function in one-carbon metabolism to allow the de novo synthesis of amino acids and nucleosides. We show that germ cell proliferation is stimulated by the folate 10-formyl-tetrahydrofolate-Glun both in vitro and in animals. Other folates that can act as vitamins to rescue folate deficiency lack this germ cell stimulatory activity. The bacterial folate precursor dihydropteroate also promotes germ cell proliferation in vitro and in vivo, despite its inability to promote one-carbon metabolism. The folate receptor homolog FOLR-1 is required for the stimulation of germ cells by 10-formyl-tetrahydrofolate-Glun and dihydropteroate. This work defines a folate and folate-related compound as exogenous signals to modulate germ cell proliferation.

Progranulin and short-term outcome in patients with acute ischaemic stroke

BACKGROUND AND PURPOSE

Stroke is a leading cause of death and severe disability worldwide. Serum biomarkers play a critical role in the assessment of the severity and prognosis in stroke patients.

METHODS

In this prospective cohort study, the measurement of serum progranulin (PGRN) was conducted in 316 participants, including 216 patients with an identified diagnosis of acute ischaemic stroke and 100 normal control subjects. The primary end-point was defined as all-cause mortality for a short-term follow-up of 6 months. Adverse functional outcome (modified Rankin Scale score ≥3) was considered as the secondary end-point.

RESULTS

The median value of serum PGRN for patients with acute ischaemic stroke was 64.2 ng/ml (interquartile range 54.6-73.7), which was significantly higher than the control group [59.7 (54.4-64.4) ng/ml; P < 0.001]. Multivariable linear regression suggested that PGRN levels were significantly correlated with body mass index, alcohol consumption, fasting blood glucose, total cholesterol, National Institutes of Health Stroke Scale (NIHSS) score and high-density lipoprotein cholesterol. Serum PGRN concentrations were independently associated with increased risks of all-cause mortality and adverse functional outcome after adjustment for clinical variables. In Cox proportional hazards models, PGRN levels were associated with the risk of mortality (hazard ratio 1.090, 95% confidence interval 1.033-1.150, P = 0.002). The net reclassification improvement of the model with added PGRN was 0.1902 (P = 0.0234) after adjustment for the variables in the Cox regression model for predicting all-cause mortality, and the integrated discrimination improvement was 0.1052 (P < 0.001).

CONCLUSIONS

Serum PGRN levels independently predicted all-cause mortality and adverse functional outcome in the short term in stroke patients. The discriminative power was improved by PGRN on the basis of NIHSS score.

Differences in Growth, and Nitrogen Uptake and Storage Between Two Container-Grown Cultivars of Rhododendron

One-year-old liners of an evergreen rhododendron (Rhododendron L. ‘H-1 P.J.M’) and a deciduous azalea (Rhododendron L. ‘Cannon's Double’) were used to determine nitrogen (N) uptake, remobilization, and storage in relation to plant growth from May to September. Plants were grown in a substrate of equal parts (by vol) vermiculite, pumice, and sandy loam soil and received liquid fertilization with or without N. Rate of N uptake was correlated with the rate of plant growth and maximum uptake occurred during July [azalea, &gt;4 mg/day (1.4E – 04 oz/day)] and August [rhododendron, &gt;2 mg/day (7.1E – 05 oz/day)]. Compared to the rhododendron used in this study, the azalea cultivar grew faster and had a greater rate of N uptake and uptake efficiency (azalea, 12 to 33%; rhododendron, 8 to 16%). The old leaves of the rhododendron remobilized N for new growth. New azalea leaves exported approx. 40% of their N by September when the stems and roots were actively accumulating biomass. The roots, stems and new leaves of the rhododendrons were still accumulating biomass by September. Our results suggest that transplanted 1-year-old liners of rhododendron and azalea contained sufficient N reserves in both the plant and substrate to support initial plant growth and that increasing availability of N in the substrate during the period of rapid growth can significantly increase N uptake while improving vegetative growth and the N status of both rhododendron and azalea.

Down-regulation of CD44 contributes to the differentiation of HL-60 cells induced by ATRA or HMBA

CD44 is highly expressed in human acute myeloid leukemia (AML) cells. Some experiments had shown that it was possible to reverse differentiation blockage in AML cells by CD44 ligation with specific antibodies, indicating that CD44 was closely related to the differentiation of leukemia cells. The differentiation of acute promyelocytic leukemia cell line HL-60 cells could be induced by all trans-retinoic acid (ATRA) and hexamethylene bisacetamide (HMBA), but so far the mechanism was not demonstrated clearly. In the present study, we investigated whether ATRA or HMBA induced the growth arrest of HL-60 cells by down-regulating the expression of CD44. The results indicated that the proliferation of HL-60 cells was obviously inhibited and the differentiation was induced by both ATRA and HMBA. The decreased expression of CD44 and cyclin E mRNA, and the increased expression of p27 and p21 at mRNA levels were observed. Furthermore, there was a negative correlation between the expression of CD44 and p27. It was concluded that ATRA and HMBA played a role in the differentiation induction of HL-60 cells, which was mediated by the down-regulation of CD44, accompanied by down-regulation of cyclin E, and up-regulation of p27 and p21 mRNA.

The molecular mechanism of HDAC inhibitors in anticancer effects

HDACs and HATs are two kinds of enzymes which catalyse deacetylation and acetylation of histone in eukaryotes, whose dynamic balance has accurate regulation for gene transcription and gene expression of eukaryotes at DNA level. Disbalance of them can bring the disorder of proliferation and differentiation in normal cells, and then lead to the initiation of tumor. Their aberrant functions were directly related to the initiation and progression of various tumors, such as promyelocytic leukemia, Hodgkin lymphoma, colonic cancer and gastral cancer. The inhibitors of HDACs are used for treatment of tumor. They can restrain the activity of HDACs and block the inhibition of gene expression caused by the disorder of deacetylation. Its major biological effects lie in inducing differentiation of tumor cells, arresting cell circle at G0/G1, activating cell apoptosis gene, enhancing the sensitivity of chemical therapy and radioactive therapy. So far HDAC has been an important target enzyme in anticancer drug research.

Expression of testis specific ankyrin repeat and SOCS box-containing 17 gene

Human ASB-17 (Ankyrin Repeat and SOCS Box-containing 17) is a recently identified gene belonging to the ASB family, isolated from testis cDNA library. Human ASB-17 is expressed exclusively in testis among 16 tissues, revealed by Northern blot. Mouse Asb-17 was shown to be expressed from the third week post birth to adult by semi-quantitative RT-PCR analysis. In situ hybridization on frozen sections demonstrated that Asb-17 is expressed in spermatogenic cells in adult mouse, but not in Leydig cell and epididymis in adult mouse. ASB-17 proteins are highly conserved in mammals including human, mouse, rat, Canis familiaris and Macaca fascicularis.

Selective presynaptic propagation of long-term potentiation in defined neural networks

Induction of long-term potentiation (LTP) of the synaptic connection between two hippocampal glutamatergic neurons in a neural network formed in cell culture resulted in a specific pattern of potentiation at other connections within the network. We found that potentiation propagated from the site of induction retrogradely to glutamatergic or GABAergic synapses received by the dendrites of the presynaptic neuron and laterally to those made by its axonal collaterals onto other glutamatergic cells. In contrast, synapses made by the same presynaptic neuron onto GABAergic cells were not affected, and there was no postsynaptic lateral or forward propagation to other synapses received or made by the postsynaptic neuron. In addition, there was no secondary propagation to synapses not directly associated with the presynaptic neuron. Both induction and propagation of LTP required correlated spiking of the postsynaptic cell as well as the activation of the NMDA subtype of glutamate receptors. Such selective propagation suggests the existence of a long-range cytoplasmic signaling within the presynaptic neuron, leading to a specific pattern of coordinated potentiation along excitatory pathways in a neural network.

[Germline LKB1 gene mutation screening in 4 Chinese Peutz-Jeghers syndrome pedigrees]

OBJECTIVE

To evaluate the frequency and nature of LKB1 gene germline mutations in 4 large Chinese Peutz-Jeghers syndrome pedigrees.

METHODS

Four Chinese Peutz-Jeghers syndrome pedigrees were investigated. Two patients and 1 normal adult from each pedigree were selected, and genomic DNA from peripheral blood was extracted. The 9 exons of LKB1 gene were amplified by PCR. The products were tested by SSCP and abnormally shifted bands were sequenced. If there was no positive finding in any pedigree, the entire exons were sequenced.

RESULTS

The same 842 C deletion of LKB1 gene frame-shift mutations was found in 2 pedigrees, which resulted in truncated protein. No exon variant was found in the left 2 pedigrees.

CONCLUSIONS

LKB1 gene germline mutation is an important molecular pathogen of Peutz-Jeghers syndrome. 842 C deletion is a possible mutation hotspot and might be a common-ancestor mutation characteristic of Chinese.

[The rapid effects of steroids on glycine uptake in neuroblastoma cell strain SK-N-SH cells]

In the present study, glycine uptake in SK-N-SH cells was determined with liquid scintillation technique, and the rapid effects of steroids on glycine uptake in SK-N-SH cells were investigated. The results were as follows. High-affinity glycine uptake in SK-N-SH cells was dependent on Na+ and Cl-. Corticosterone (CORT), progesterone (P) and dexamethasone (DEX) had rapid effects on the glycine uptake. Since estradiol (E2) and deoxycorticosterone (DOC) had no effects, it was suggested that the rapid effects of steroids were specific. The rapid effects of CORT were concentration-dependent in a range of 10(-9)-10(-6) mol/L. The rapid effects were not affected by the inhibitor of protein synthesis and persisted even when CORT was conjugated with bovine serum album, but attenuated when Ca2+ was absent in the external medium. The results suggest that the steroid effect on glycine uptake in SK-N-SH cells was nongenomicly mediated.

Distributed synaptic modification in neural networks induced by patterned stimulation

Activity-dependent changes in synaptic efficacy or connectivity are critical for the development, signal processing and learning and memory functions of the nervous system. Repetitive correlated spiking of pre- and postsynaptic neurons can induce a persistent increase or decrease in synaptic strength, depending on the timing of the pre- and postsynaptic excitation. Previous studies on such synaptic modifications have focused on synapses made by the stimulated neuron. Here we examine, in networks of cultured hippocampal neurons, whether and how localized stimulation can modify synapses that are remote from the stimulated neuron. We found that repetitive paired-pulse stimulation of a single neuron for brief periods induces persistent strengthening or weakening of specific polysynaptic pathways in a manner that depends on the interpulse interval. These changes can be accounted for by correlated pre- and postsynaptic excitation at distant synaptic sites, resulting from different transmission delays along separate pathways. Thus, through such a 'delay-line' mechanism, temporal information coded in the timing of individual spikes can be converted into and stored as spatially distributed patterns of persistent synaptic modifications in a neural network.

Triplex formation by oligonucleotides containing novel deoxycytidine derivatives

Homopurine sequences of duplex DNA are binding sites for triplex-forming oligodeoxyribopyrimidines. The interactions of synthetic duplex DNA targets with an oligodeoxyribopyrimidine containing N4-(6-amino-2-pyridinyl)deoxycytidine (1), a nucleoside designed to interact with a single C-G base pair interruption of the purine target tract, was studied by UV melting, circular dichroism spectroscopy and dimethylsulfate alkylation experiments. Nucleoside 1 supports stable triplex formation at pH 7.0 with formation of a 1-Y-Z triad, where Y-Z is a base pair in the homopurine tract of the target. Selective interaction was observed when Y-Z was C-G, although A-T and, to a lesser extent, T-A and G-C base pairs were also recognized. The circular dichroism spectra of the triplex having a 1-C-G triad were similar to those of a triplex having a C(+)-G-C triad, suggesting that the overall structures of the two triplexes are quite similar. Removal of the 6-amino group from 1 essentially eliminated triplex formation. Reaction of a triplex having the 1-C-G triad with dimethylsulfate resulted in a 50% reduction of methylation of the G residue of this triad. In contrast, the G of a similar triplex containing a U-C-G triad was not protected from methylation by dimethylsulfate. These results are consistent with a binding mode in which the 6-amino-2-pyridinyl group of 1 spans the major groove of the target duplex at the 1-C-G binding site and forms a hydrogen bond with the O6 of G. An additional stabilizing hydrogen bond could form between the N4 of the imino tautomer of 1 and the N4 amino group of C.

Triplex formation by a psoralen-conjugated oligodeoxyribonucleotide containing the base analog 8-oxo-adenine

Oligodeoxyribonucleotides containing thymidine and 8-oxo-2'-deoxyadenosine can form pyr.pur.pyr type triplexes with double-stranded DNA. Unlike triplexes whose third strands contain thymidine and deoxycytidine, the stability of these triplexes is independent of pH. We have prepared d-ps-TAAATAAATTTTTAT-L [I(A)], where A is 8-oxo-2'-deoxyadenosine, ps is 4'-hydroxymethyl-4,5',8- trimethylpsoralen and L is a 6-amino-2-(hydroxymethyl)hexyl linker. The oligomer is designed to interact with a homopurine sequence in the promoter region of the human gene coding for the 92 kDa form of collagenase type IV. Oligomer I(A) and oligomer I(C), which contains 2'-deoxycytidine in place of 8-oxo-2'-deoxycytidine, both form stable triplexes at pH 6.2, but only I(A) forms a stable triplex with a model duplex DNA target at pH 7.5, as determined by UV melting experiments. Triplex formation is stabilized by the presence of the psoralen group. Upon irradiation both I(A) and I(C) form photoadducts with the DNA target at pH 6.2, but only I(A) forms a photoadduct at pH 7.5. In these photoreactions oligomer I(A) appears to selectively form a photoadduct with a C in the purine-rich strand of the duplex target. Although a T residue is present in the pyrimidine-rich strand of the target at the duplex/triplex junction, essentially no adduct formation takes place with this strand, nor is interstrand cross-linking observed. The extent of photoadduct formation decreases with increasing temperature, behavior which is consistent with the UV melting curve of the triplex. A tetramethylrhodamine derivative of I(A) was prepared and found to cross-link less extensively than I(A) itself. Oligomer I(A) is completely resistant to hydrolysis when incubated for 24h in the presence of 10% fetal bovine serum at 37 degree C, although it is hydrolyzed by S1 nuclease. The properties of oligomer I(A) suggest that 8-oxo- containing oligomers may find utility as antigene oligonucleotide reagents.

Cell membrane resealing by a vesicular mechanism similar to neurotransmitter release

After injury to the cell membrane, rapid resealing of the membrane occurs with little loss of intracellular contents. This process has been studied by measurement of the rate of dye loss after membrane puncture in both the sea urchin embryo and 3T3 fibroblasts. Resealing of disrupted cell membranes requires external calcium that can be antagonized by magnesium. Block of multifunctional calcium/calmodulin kinase, which regulates exocytotic vesicle availability at synapses, and of kinesin, which is required for outward-directed transport of vesicles, inhibited membrane resealing. Resealing was also inhibited by botulinum neurotoxins B and A, suggesting that the two synaptosomal-associated proteins synaptobrevin and SNAP-25 also participate in resealing. This pattern of inhibition indicates that the calcium-dependent mechanisms for cell membrane resealing may involve vesicle delivery, docking, and fusion, similar to the exocytosis of neurotransmitters.

[Changes of angiotensin II contents in rat plasma, brain, cardiovascular system and adrenal during stress]

The changes of content of angiotensin II (A II) in plasma, anterior hypothalamus, medulla oblongata, myocardium, vasculature and adrenals during acute and chronic stress were studied in rats. Compulsive cold-water swimming and trauma by limb-breaking were used to set acute stress models while cold environment of 4-8 degrees C was used to set chronic stress model. The results showed that: (1) The A II levels in plasma were significantly increased in all three stress- model groups, reaching to 900%, 390% and 134% of the control in the swimming group, the limb-broken group and the cold environment group, respectively. It's clear that the level of angiotension II in the acute stress groups were much higher than those in the chronic stress group. (2) The A II levels of the rat brain, myocardium and blood vessel were also increased in the stress animals except the limb-broken group. Furthermore, the contents of angiotensin II of the chronic stress animals were significantly higher than those of the acute stress animals in the brain, myocardium and blood vessels, but not in the adrenals. (3) The adrenal A II content was significantly higher than that of the control in all stressed animals. (4) The plasma corticosterone was also significantly increased over the control level in both the acute and chronic stress groups. These results suggest that circulating angiotensin II and tissue angiotensin II may play a role during the development of acute and chronic stress, respectively.

Heterokaryon myotubes with normal mouse and Duchenne nuclei exhibit sarcolemmal dystrophin staining and efficient intracellular free calcium control

Duchenne and mdx muscle tissues lack dystrophin where it normally interacts with glycoproteins in the sarcolemma. Intracellular free calcium ([Ca2+]i) is elevated in Duchenne and mdx myotubes and is correlated with abnormally active calcium-specific leak channels in dystrophic myotubes. We fused Duchenne human and normal mouse myoblasts and identified heterokaryon myotubes by Hoechst 33342 staining to measure the degree to which dystrophin introduced by normal nuclei could incorporate throughout the myotube at the sarcolemma and restore normal calcium homeostasis. Dystrophin expression in myotubes was determined by immunofluorescence and confocal laser scanning microscopy. Dystrophin was expressed at the sarcolemma in normal mouse and heterokaryon myotubes, but not in Duchenne myotubes. In heterokaryons, extensive dystrophin localization occurred at the sarcolemma even where only Duchenne nuclei were present, indicating that dystrophin does not exhibit nuclear domains. Heterokaryon, normal mouse and Duchenne myotube [Ca2+]i was measured using fura-2 and fluorescence ratio imaging. Heterokaryon and normal mouse myotubes were found to maintain similar levels of [Ca2+]i. In contrast, Duchenne myotubes had significantly higher [Ca2+]i (p < 0.001). Furthermore, the ability of heterokaryons to maintain normal [Ca2+]i did not depend on greater numbers of normal nuclei than Duchenne being present in the myotube. These results support the view that dystrophin expression in heterokaryons allows for efficient control of [Ca2+]i.

Changes in circulating and tissue angiotensin II during acute and chronic stress

Changes of angiotensin II and cAMP in plasma, brain tissue, adrenal gland and cardiovascular tissue during the acute and chronic stress were studied in rats. The acute stress group was subjected to compulsive cold water swimming for 20 min, while the chronic stress group was exposed to an ambient temperature of 4-8 degrees C for 5 days. The results indicated that plasma angiotensin II levels were significantly increased in both stress groups, reaching up to 900% and 134% of the control in the acute and chronic groups, respectively. Angiotensin II contents in the anterior hypothalamus, medulla oblongata, myocardium, vasculature and adrenals were also elevated in both groups. With the exception of the adrenals, the contents of tissue angiotensin II in the chronic stress animals were significantly higher than those of the acute stress animals. In contrast, cAMP levels in plasma and tissue (hypothalamus and adrenals) and corticosterone levels in plasma in the acute stress group were all higher than those in the chronic stress animals, although the levels of the latter group were also increased compared with the control group. These results suggest that circulating and tissue angiotensin II may play an important role in the acute and chronic stress responses and that angiotensin II should be classified as a stress hormone.

[Morphine decreased the content of cyclic AMP in the rat spinal cord]

It has been reported that morphine or opiate-like substances (OLS) can affect the contents of cyclic AMP and/or cyclic GMP in mammalian brain, but very little is known whether similar effects also occur in spinal cord. Using RIA method, we showed that morphine significantly decreased the content of cyclic AMP in the rat spinal cord in vivo and in vitro and this effect could be completely blocked by naloxone, while the concentration of cyclic GMP in rat spinal cord is unchanged. In view of the present experiment it is suggested that the changes of cyclic AMP in the central nervous system may be partly mediated by the action of morphine.