Methamphetamine (METH) is a powerful stimulant drug that can cause addiction and serious health problems. It is one of the most widely abused drugs in the world. However, the mechanisms of how METH affects the brain and leads to addiction are still unclear, and there are no effective treatments for METH addiction in clinical practice. Therefore, it is important to explore the new addiction mechanisms and treatment strategies of METH. METH addiction is a complex and chronic brain disorder that involves multiple brain regions and neurotransmitter systems. Neurotransmitters are chemical messengers that transmit signals between neurons (nerve cells) in the brain. Some of the main neurotransmitters involved in METH addiction are dopamine (DA), glutamate (Glu), norepinephrine (NE), and serotonin (SNRIS). These neurotransmitters regulate various aspects of brain function, such as reward, reinforcement, motivation, cognition, emotion, and behavior. When a person takes METH, it causes a surge of these neurotransmitters in the brain, especially in the prefrontal cortex (mPFC), ventral tegmental area (VTA), and nucleus accumbens (NAc). These brain regions form a circuit called the mesocorticolimbic system, which is responsible for mediating the rewarding and reinforcing effects of drugs and natural stimuli. The increased levels of neurotransmitters in this circuit make the person feel euphoric, alert, confident, and energetic. However, repeated or chronic use of METH can also cause negative effects, such as anxiety, paranoia, psychosis, depression, and cognitive impairment. The effects of METH on the brain are not only due to the changes in neurotransmitter levels, but also to the changes in gene expression. Gene expression is the process by which genes are turned on or off to produce proteins that perform various functions in the cells. Gene expression can be influenced by environmental factors, such as drugs, stress, diet, etc. One way that environmental factors can affect gene expression is through epigenetic mechanisms. Epigenetics is a branch of genetics that studies the heritable changes in gene expression that are not caused by changes in DNA sequence. Epigenetic mechanisms include histone modifications, DNA methylation, and non-coding RNA regulation. These mechanisms can modulate the chromatin structure and accessibility, thereby affecting the transcriptional activity of genes. Chromatin is a complex of DNA and proteins that forms the chromosomes in the nucleus of the cell. The chromatin structure can be altered by adding or removing chemical groups to histones (proteins that wrap around DNA) or DNA itself. These chemical groups can either activate or repress gene expression by changing the affinity of transcription factors (proteins that bind to DNA and initiate transcription) or other regulatory molecules. Non-coding RNAs are RNA molecules that do not code for proteins but can regulate gene expression by interacting with DNA, RNA, or proteins. Epigenetic mechanisms provide a link between environmental stimuli and gene expression, and play an important role in various physiological and pathological processes, including drug addiction. Recent studies have shown that epigenetic mechanisms are involved in the regulation of neurotransmitter systems and neural plasticity in response to METH exposure. Neural plasticity is the ability of neurons to change their structure and function in response to experience or injury. Neural plasticity is essential for learning, memory, adaptation, and recovery. The expression of some genes related to METH addiction is altered by epigenetic modifications, such as histone acetylation, methylation, ubiquitination, and non-coding RNA regulation. These epigenetic changes may affect the synaptic function and morphology, neuronal connectivity, and circuitry formation in the brain regions implicated in METH addiction. Moreover, some epigenetic modifications may persist for a long time after METH withdrawal, suggesting that they may contribute to the development and maintenance of METH addiction. In this article, we review the current literature on the epigenetic mechanisms of METH addiction. We will first introduce METH and its pharmacological effects, and then discuss the epigenetic regulation of neurotransmitter systems and neural plasticity by METH. We will focus on the changes of histone, DNA, and RNA during METH addiction, and the possible causes and consequences of their relationship with METH addiction. We will also provide some perspectives on the potential applications of epigenetic interventions for METH addiction treatment.

Objective To investigate the expression and prognostic significance of mediator complex subunit 8 (MED8) in gastric cancer and its impact on the cell cycle.Methods The expression of MED8 in gastric cancer and adjacent tissues and its correlation with patients' prognosis were analyzed using public databases.A validation cohort of 104 patients who underwent radical resection for gastric cancer in the First Affiliated Hospital of Bengbu Medical College from June 2012 to July 2017 was included.The receiver operating characteristic curve was established to evaluate the predictive value of MED8 for postoperative 5-year survival.Bioinformatics tools were used to predict the biological roles of MED8 in gastric cancer.The effect of the MED8 level on the G1/S phase transition of gastric cancer cells (MGC-803) was analyzed via lentivirus transduction and flow cytometry.Western blotting was carried out to assess the impact of MED8 expression on the protein levels of cyclin-dependent kinase 4(Cdk4) and G1/S-specific cyclin-D1(CyclinD1) in MGC-803 cells.Results The high expression of MED8 in the gastric cancer tissue was associated with poor prognosis (P<0.001) and had prognostic significance (area under curve=0.733,P<0.001).Gene enrichment analysis suggested that MED8 may participate in the cell cycle process.Flow cytometry results revealed that the upregulation of MED8 expression promoted the transition of MGC-803 cells from the G1 phase to the S phase (P<0.001),while the downregulation of MED8 had the opposite effect (P<0.001).Western blotting showed increases in the protein levels of Cdk4 and CyclinD1 in MGC-803 cells with upregulated MED8 expression (all P<0.001),and decreases in the cells with downregulated MED8 expression (all P<0.001).Conclusion MED8 is highly expressed in gastric cancer and may affect its progression and prognosis by regulating the G1/S phase transition of gastric cancer cells.
Humans ; Stomach Neoplasms ; Prognosis ; Cell Proliferation ; Cell Cycle ; Mediator Complex/metabolism* ; Cell Line, Tumor

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.
Cross-Sectional Studies ; HIV Infections/epidemiology* ; HIV-1 ; Homosexuality, Male ; Humans ; Immunoenzyme Techniques ; Incidence ; Male ; Sexual and Gender Minorities

Objective To investigate and control the outbreak of infection caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) in a gastroenterology intensive care unit (ICU), so as to provide reference for the prevention and control of clinical multidrug-resistant organisms (MDROs).Methods Epidemiological investigation was conducted on 3 patients with CRKP infection in a gastroenterology ICU on January 21-31, 2018, specimens were collected with environmental biology monitoring method, CRKP in environment was searched, homology between patients and environmental isolates were analyzed by pulsed-field gel electrophoresis (PFGE).Results Three patients were all isolated CRKP from sputum and blood specimens, all were male, with adjacent beds in the same ward, and treated by the same doctor.The number of isolated CRKP and infection rate in January 2018 were higher than those in other months, infection rate was significantly different (χ2=13.67, P＜0.01).A total of 102 environmental specimens were collected, including air and surface of objects, only 1 of which (nurse's uniform) was isolated 1 strain of KP.PFGE typing of KP isolated from patients and environment showed that there were two genotypes A and B, KP isolated from uniform of a nurse, hydrops abdominis and blood specimen of patient at bed 07, blood specimen of patient at bed 08, as well as sputum and blood specimen of patient at bed 09 were all type A, KP isolated from sputum specimen of patient at bed 07 was type B, KP isolated from hydrops abdominis in patient at bed 09 was not be typed.After comprehensive intervention, CRKP was not no longer isolated from 3 patients, and there was no new case in the ward.Conclusion Imperfect implementation of prevention and control measures for MDROs by health care workers may be an important cause for the spread of CRKP.

Notopterol, isoimperatorin, volatile oil and extract （water and ethanol) were used as the research objects in this study to investigate the effects of different softening method, slice thickness and drying methods on the quality of Notopterygii Rhizoma et Radix slices, and the experimental data were analyzed by homogeneous distance evaluation method. The results showed that different softening, cutting and drying processes could affect the content of five components in Notopterygii Rhizoma et Radix incisum. The best processing technology of Notopterygii Rhizoma et Radix slices was as follows: non-medicinal parts were removed; mildewed and rot as well as moth-eaten parts were removed; washed by the flowing drinking water; stacked in the drug pool; moistening method was used for softening, where 1/8 volume of water was sprayed for every 1 kg of herbs every 2 h; upper part of herbs covered with clean and moist cotton, and cut into thick slices (2-4 mm) after 12 h moistening until appropriate softness, then received blast drying for 4 h at 50 ℃, and turned over for 2 times during the drying. The process is practical and provides the experimental basis for the standardization of the processing of Notopterygii Rhizoma et Radix, with great significance to improve the quality of Notopterygii Rhizoma et Radix slices.

Study on the standardization of Chinese materia medica is an important action for modernization and globalization for traditional Chinese medicine. Standardization on the processing of Chinese herbal pieces is an important part in the study on standardization of Chinese materia medica, so it is of great significance to establish the technical processing standards of Angelicae Sinensis Radix pieces for improving its quality. In this study, single factor experiment was designed to optimize the softening, cutting and drying processes of Angelicae Sinensis Radix. With ferulic acid, Angelicae Sinensis Radix polysaccharide, volatile oil and extracts (water and ethanol) content as the quality index, the effects of different softening, cutting and drying processes on the contents of the five components in Angelicae Sinensis Radix were analyzed, and the normalized distance evaluation method was used to analyze the experimental data. The results showed that the content of five components in Angelicae Sinensis Radix was affected by different softening methods and drying temperature, but the thickness of slice had little effect on the content. The best preparation process for Angelicae Sinensis Radix was as follows: Non-medicinal parts were removed; mildewed and rot as well as moth-eaten parts were removed; washed by the flowing drinking water; stacked in the drug pool; moistening method was used for softening, where 125 mL water was sprayed for every 1 kg of herbs every 2.5 h; upper part of herbs covered with clean and moist cotton, and cut into thin slices (1-2 mm) after 15 h moistening until appropriate softness, with disk thickness of 1-2 cm, then received blast drying for 6 h at 55 ℃, and turned over for 2 times during the drying.

OBJECTIVETo investigate the role of microtubule-actin crosslinking factor 1 (MACF1) in the response of glioma cells to temozolomide (TMZ).

METHODSTMZ was applied to a human gliomablastoma cell line (U87) and changes in the protein expression and cellular localization were determined with Western blot, RT-PCR, and immunofluorescence. The responses of the cells with MACF1 expression knockdown by RNA interference to TMZ were assessed. TMZ-induced effects on MACF1 expression were also assessed by immunohistochemistry in a nude mouse model bearing human glioblastoma xenografts.

RESULTSTMZ resulted in significantly increased MACF1 expression (by about 2 folds) and changes in its localization in the gliomablastoma cells both in vitro and in vivo (P<0.01). Knockdown of MACF1 reduced the proliferation (by 45%) of human glioma cell lines treated with TMZ (P<0.01). TMZ-induced changes in MACF1 expression was accompanied by cytoskeletal rearrangement.

CONCLUSIONMACF1 may be a potential therapeutic target for glioblastoma.

The method of UHPLC-LTQ-Orbitrap mass spectrometry coupled with higher energy collision dissociation (HCD) was established to rapidly analyze the constituents absorbed into blood after oral administration of steroidal saponins from Radix Ophiopogonis. A total of 31 constituents, including 13 furostanol steroidal saponins and 18 spirostanol steroidal saponins, were characterized based on the accurate mass measurements, fragmentation patterns, chromatographic retention times, and diagnostic product ions. Among them, 8 compounds were unambiguously identified by comparison with their corresponding standards. The results provide comprehensive insights and guidance for elucidation of material basis of Radix Ophiopogonis activity.

BACKGROUND AND OBJECTIVEInvasion and metastasis are the most common causes of mortality for patients with colorectal neoplasms, and blocking invasion and metastasis in a timely fashion has become a hot research focus. We investigated the expression of the messenger RNA of Syndecan-1 and HPA-1 in colorectal cancer, and their correlation with invasion and metastasis.

METHODSReal-time fluorescent quantitative polymerase chain reaction (PCR) was used to detect the expression of Syndecan-1 and HPA-1 in specimens from 49 patients with colorectal cancer, 49 paired adjacent colorectal neoplasms (2 cm from the carcinoma), and 49 surgical margins of paired normal colorectal mucosa tissue (5 cm from the carcinoma), to analyze their correlation with clinicopathologic characteristics of colorectal neoplasm.

RESULTSThe expression of HPA-1 mRNA was significantly higher in colorectal cancer (40.56 +/- 11.75) than that in the paired adjacent colorectal neoplasms (18.28 +/- 11.33) and normal colorectal mucosa tissue (10.80 +/- 10.20) (all P < 0.001). The expression of HPA-1 mRNA was significantly higher in paired adjacent colorectal neoplasms than that in normal colorectal mucosa (P < 0.05). The expression of Syndecan-1 mRNA was significantly higher in normal colorectal mucosa (61.21 +/- 12.96) than in the paired adjacent mucosa (14.35 +/- 11.06) or colorectal cancer (10.12 +/- 8.58) (all P < 0.001). The expression of Syndecan-1 mRNA was significantly higher in the paired adjacent mucosa than that in colorectal cancer (P < 0.05). The decreased expression of Syndecan-1 mRNA and the increased expression of HPA-1 were closely associated with the degree of differentiation, the depth of infiltration, lymph node metastasis, vessel metastasis, and TNM staging of colorectal cancer (all P < 0.05). Spearman rank correlation analysis demonstrated a significant correlation between Syndecan-1 and HPA-1(r = -0.405, P < 0.05).

CONCLUSIONSThe expression of Syndecan-1 mRNA was significantly highest in normal colorectal mucosa and the expression of HPA-1 mRNA was significantly highest in colorectal cancer. At the same time, the decreased expression of Syndecan-1 mRNA and the increased expression of HPA-1 mRNA can promote the invasion and metastasis of colorectal cancer. The determination of Syndecan-1 and HPA-1 may be of value in the treatment as well as in the prognosis of patients with colorectal cancer.

Adenocarcinoma ; metabolism ; pathology ; Colorectal Neoplasms ; metabolism ; pathology ; Gene Expression Regulation, Neoplastic ; Glucuronidase ; genetics ; metabolism ; Humans ; Intestinal Mucosa ; metabolism ; pathology ; Lymphatic Metastasis ; Neoplasm Invasiveness ; Neoplasm Staging ; Prognosis ; RNA, Messenger ; metabolism ; Real-Time Polymerase Chain Reaction ; Syndecan-1 ; genetics ; metabolism

Background and Objective:Invasion and metastasis are the most common causes of mortality for patients with colorectaI neoplasms,and blocking invasion and metastasis in a timely fashion has become a hot research focus.We investigated the expression of the messenger RNA (mRNA)of Syndecan-1 and HPA-1 in colorecta J cancer,and their correlation with invasion and metastasis.Methods:Real-time fluorescent quantitative reverse transcription polymerase chain reaction(RT-PCR)was used to detect the expression of Syndecan-1 and HPA-1 in specimens from 49 patients with colorectal cancer.49 paired adjacent colorectal neoplasms(2 cm from the carcinoma),and 49 surgical margins of paired normal colorectal mucosa tissue(5 cm from the carcinoma),to analyze their correlation with clinicopathologic characteristics of colorectal neoplasm.Results:The expression of HPA-1 mRNA was significantly higher in colorectal cancer (40.56±11.75)than that in the paired adjacent colorectal neoplasms(18.28±11.33)and normal colorectal mucosa tissue(10.80±1020)(all P＜0.001).The expression of HPA-1 mRNA was significantly higher in paired adjacent colorectal neoplasms than that in normal colorectal mucosa(P＜0.05).The expression of Syndecan-1 mRNA was significantly higher in normal colorectal mucosa(61.21±12.96)than in the paired adjacent mucosa (14.35±11.06)or colorectaI cancer(10.12±8.58)(all P＜0.001).The expression of Syndecan-1 mRNA was significantly higher in the paired adjacent mucosa than that in colorectal cancer(P＜0.05).The decreased expression of Syndecan-1 mRNA and the increased expression of HPA-1 were closely associated with the degree of differentiation,the depth of infiltration,lymph node metastasis,vessel metastasis,and TNM staging of colorectal cancer(all P＜0.05).Spearman rank correlation analysis demonstrated a significant correlation between Syndecan-1 and HPA-1(r=-0.405,P＜0.05).Conclusions:The expression of Syndecan-1 mRNA was significantly highest in normal colorectal mucosa and the expression of HPA-1 mRNA was significantly highest in colorectal cancer.At the same time,the decreased expression of Syndecan-1 mRNA and the increased expression of HPA-1 mRNA can promote the invasion and metastasis of colorectal cancer.The determination of Syndecan-1 and HPA-1 may be of value in the treatment as well as in the prognosis of patients with colorectal cancer.