Despite its clinical importance, the underlying central mechanisms of pruritic behaviors are poorly understood. To investigate the role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behaviors in mice, we tested the effect of arcuate nucleus neurons and interscapular brown adipose tissue (IBAT) on itch produced by intradermal injection of chloroquine in the nape of the neck. Our results provide several lines of evidence for an important role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behavior: (1) Intradermal microinjection of chloroquine resulted in a dramatic increase in itch behaviors accompanied by the activation of c-Fos positive neurons in arcuate nucleus; (2) Microinjection of chloroquine significantly increased IBAT temperature in the mice. These findings suggested that chloroquine-induced pruritic behaviors were associated with the activity of nociceptive arcuate nucleus neurons.

BACKGROUND:The establishment of a safe, reliable and easily repeatable mouse model of nonalcoholic fatty liver disease is the prerequisite for the study of the diagnosis and treatment of the disease.
OBJECTIVE:To establish a C57BL/6 mouse model of nonalcoholic fatty liver disease and observe changes of biochemical indicators, which can provide a theoretical basis for its pathogenesis and drug treatment.
METHODS:Sixty healthy male C57BL/6 mice were randomly divided into a control group of 30 cases (normal diet), and a model group of 30 cases (high fat diet). Models of nonalcoholic fatty liver were established. At 8 weeks, body mass, liver index, and homogenate superoxide dismutase activity in the liver were detected. Changes in serum alanine aminotransferase, aspartate aminotransferase, triglyceride glycerol, cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were observed. Pathological examination was performed.
RESULTS AND CONCLUSION:(1) Pathological sections showed that large droplets and smal lipid droplets in the mouse liver and spread the whole liver. Swel ing of the liver cel s, visible cytoplasmic vacuoles and obviously inflammatory changes in liver cel s were observed in the model group. (2) Body weight and liver index were significantly higher in the model group than in the control group (P<0.05). Superoxide dismutase activity was significantly reduced in the liver (P<0.05). (3) Triglycerides, cholesterol, and low-density lipoprotein cholesterol levels were significantly higher, but high-density lipoprotein cholesterol levels were significantly lower in the model group than in the control group (P<0.05). (4) Nonalcoholic fatty liver mouse model is ideal for high-fat diet-induced animal model. The method is simple, repetitive, and can provide a stable animal model for the study on the mechanism of nonalcoholic fatty liver disease and drug treatment.

Despite its clinical importance, the underlying central mechanisms of pruritic behaviors are poorly understood. To investigate the role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behaviors in mice, we tested the effect of arcuate nucleus neurons and interscapular brown adipose tissue (IBAT) on itch produced by intradermal injection of chloroquine in the nape of the neck. Our results provide several lines of evidence for an important role of nociceptive arcuate nucleus neurons in chloroquine-induced pruritic behavior: (1) Intradermal microinjection of chloroquine resulted in a dramatic increase in itch behaviors accompanied by the activation of c-Fos positive neurons in arcuate nucleus; (2) Microinjection of chloroquine significantly increased IBAT temperature in the mice. These findings suggested that chloroquine-induced pruritic behaviors were associated with the activity of nociceptive arcuate nucleus neurons.
Animals ; Arcuate Nucleus of Hypothalamus ; drug effects ; physiopathology ; Chloroquine ; adverse effects ; Male ; Mice ; Mice, Inbred C57BL ; Nociceptors ; drug effects ; physiology ; Pruritus ; chemically induced ; physiopathology

Objective:To investigate the effect of virus inactivation on weak positive result of 2019 novel coronavirus(2019-nCoV) nucleic acid test.Methods:A retrospective study was conducted on the nasopharyngeal swabs of three patients with positive PCR nucleic acid test for 2019-nCoV at different concentrations in the Second affiliated Hospital of Zhejiang University Medical College from January to February 2020.The virus in nasopharyngeal swab specimens were inactivated by water bath at 56 ℃ for 30 min, dry bath at 56 ℃ for 60 min and dry bath at 60 ℃ for 30 min respectively. After treatment, these samples RNA were extracted and then detected by three new commercial quantitative real-time polymerase chain reaction reagent kits for 2019-nCoV.Cycle threshold (Ct) value was used to evaluate the effect of virus inactivation on nucleic acid detection of 2019-nCoV.Results:There was no significant difference between the groups before and after inactivation. Ct values of ORF1ab gene before inactivation were 23.28±0.28, 25.25±0.25, 28.93±0.44, 32.06±0.47, 35.20±0.38, 32.89±0.38, 36.24±0.23, 33.30±0.46, and those after inactivation were, group 1:23.60±0.20, 27.29±0.30, 31.83±0.51, 37.41±0.46, group 2: 24.25±0.34, 27.18±0.42, 31.84±0.61, 34.99±1.01, 34.89±0.45,group 3: 23.37±0.17, 26.89±0.52, 32.05±0.50.Ct value of N gene before inactivation were 24.38±0.09, 26.64±0.11, 30.35±0.12, 33.29±0.33, 36.93±0.11, 34.50±0.12, 35.63±0.12, those after inactivation were, group 1: 24.66±0.11, 28.52±0.14, 32.71±0.14, 37.00±0.13;group 2: 25.41±0.10, 28.79±0.15, 33.29±0.28; group 3: 23.37±0.11, 28.68±0.11, 33.54±0.13, 37.18±0.23(ORF1ab gene: t=-1.416; N gene: t=-1.379, P>0.05). There was no significant difference among the three inactivation groups, the specific Ct values are shown above(ORF1ab gene: t=-0.460; N gene: t=-0.132, P>0.05). However, the Ct values of the inactivated groups (1,2,3) and the non-inactivated group at different dilution times were different (10 ×:Ct value of ORF1ab was 25.25±0.25 in the non-inactivated group, and 27.29±0.30, 27.18±0.42 and 26.89±0.52 in the inactivated group1,2 and 3, t(ORF1ab)=-7.327, P<0.01.Ct value of N gene in the non-inactivated group was26.64±0.11, those in inactivated group 1, 2 and 3 were 28.52±0.14, 28.79±0.15 and 28.68±0.11, respectively, t (N)=-19.340, P<0.01. 100 ×:Ct value of ORF1ab was 28.93±0.44 in the non-inactivated group, and 31.83±0.51,31.84±0.61 and 32.05±0.50 in the inactivated group1,2 and 3, t (ORF1ab)=-9.462, P<0.01. Ct value of N gene in the non-inactivated group was 30.35±0.12, those in the inactivated group 1, 2 and 3 were 32.71±0.14, 33.29±0.28 and 33.54±0.13, respectively, t (N)=-18.583, P<0.01. The positive detection rate of the non-inactivated group (7/11, 8/11, 5/11) was significantly different from that of the inactivated group (inactivated group 1:4/11, 4/11, 3/11, inactivated group 2:3/11, 3/11, 3/11, and inactivated group 3:3/11, 3/11, 2/11) ( Z=-2.670, P<0.01). There were no significant difference among the inactivated groups(inactivated group 1:4/11, 4/11, 3/11, inactivated group 2:3/11, 3/11, 3/11, inactivated group 3:3/11, 3/11, 2/11) ( Z=4.413, P>0.05) and among the three reagents(reagent 1:7/11, 4/11, 3/11, 3/11, reagent 2:8/11, 4/11, 3/11, 3/11, reagent 3:5/11, 3/11, 3/11, 2/11)(χ 2=1.199, P>0.05). Conclusion:The virus inactivation can degrade the nucleic acid of the 2019-nCoV, resulting in the decrease of the Ct value and the false negative results of the low-concentration specimens.