[A study of the anti-fibrotic effect of ghrelin on mice with nonalcoholic steatohepatitis]

Objective: To study the anti-fibrotic effect of ghrelin on high-fat diet-induced non-alcoholic steatohepatitis (NASH) in mice. Methods: 24 male C57BL/6 mice were randomly divided into a normal diet group, a normal diet + ghrelin group, a high-fat diet group, and the high-fat diet + ghrelin group. The HFD and HFD+ghrelin groups were fed high-fat diet for 16 weeks to induce non-alcoholic steatohepatitis. Among them, the NCD+ghrelin group and HFD+ghrelin group were continuously given ghrelin intervention (11nmol·kg(-1)·d(-1)) for 2 weeks after feeding for 14 weeks. 16 mice were euthanized on weekends. The plasma levels of alanine aminotransferase (ALT) and hyaluronic acid (HA) were measured in mice. The content of hydroxyproline (Hyp) was determined in liver tissue. RT-qPCR was used to detect the mRNA expression levels of transforming growth factor β1 (TGF-β1) and collagen types I, III, and IV in liver tissue. A Western blot was used to detect the expression level of the α-smooth muscle actin (α-SMA) protein in liver tissue. HE staining was used to observe the morphological changes in liver tissue. VG staining was used to observe the fibrotic condition in liver tissue. Results: Compared with the NCD group, plasma ALT (266.80±146.80)U/L, HA (219.00±39.47) ng/ml levels, Hyp content (0.35±0.05)μg/mg prot (P < 0.05), mRNA expression levels of transforming growth factor β1 (TGF-β1) and collagen types I, III, IV (P < 0.05), and the expression level of α-SMA protein in the HFD group were significantly increased (P < 0.05), with congestion in the hepatic central lobular veins, hepatocytes swelling, and deposition of a large amount of collagen fibers in liver tissue. Compared with the HFD group, plasma ALT (57.17±20.88)U/L, HA (75.68±8.40)μg/mg levels, Hyp content (0.19±0.07)μg/mg prot, mRNA expression levels of transforming growth factor β1 (TGF-β1) and collagen types I, III, IV (P < 0.05), and the expression level of α-SMA protein in the HFD+ghrelin mice group was significantly reduced (P < 0.05), with only mild sinusoidal congestion in the liver tissue but significant improvement and reduction in liver injury and collagen fiber deposition. Conclusion: Ghrelin has a significant improvement effect on liver fibrosis in NASH mice.

Saturn Anomalous Myriametric Radiation, a New Type of Saturn Radio Emission Revealed by Cassini

A new radio component namely Saturn Anomalous Myriametric Radiation (SAM) is reported. A total of 193 SAM events have been identified by using all the Cassini Saturn orbital data. SAM emissions are L-O mode radio emission and occasionally accompanied by a first harmonic in R-X mode. SAM's intensities decrease with increasing distance from Saturn, suggesting a source near Saturn. SAM has a typical central frequency near 13 kHz, a bandwidth greater than 8 kHz and usually drifts in frequency over time. SAM's duration can extend to near 11 hr and even longer. These features distinguish SAM from the regular narrowband emissions observed in the nearby frequency range, hence the name anomalous. The high occurrence rate of SAM after low frequency extensions of Saturn Kilometric Radiation and the SAM cases observed during compressions of Saturn's magnetosphere suggest a special connection to solar wind dynamics and magnetospheric conditions at Saturn.

Reflection and Refraction of the L-O Mode 5 kHz Saturn Narrowband Emission by the Magnetosheath

The reflection-by-sheath mechanism of 5 kHz narrowband emissions (NB) at Saturn is confirmed by Cassini observations during several crossings of the magnetopause, which show that the 5 kHz NB can be prevented from escaping Saturn's magnetosphere. The L-O mode 5 kHz NB remained visible in areas of low plasma density but disappeared in regions of high plasma density. In three cases, NB disappeared immediately after the crossings of Saturn's magnetopause. A possible reflected NB event observed near the magnetosheath is discussed. This mechanism can help explain the 5 kHz NB observed at low latitudes outside the Enceladus plasma torus and their upper frequency limit variations. This mechanism significantly improves the current understanding of the 5 kHz NB.

[Ergonomic risk factors of carpal tunnel syndrome in workers of an automobile factory]

Objective: To investigate the occurrence of pain symptoms and risk factors of carpal tunnel syndrome (CTS) in automobile manufacturing workers and provide theoretical basis for the prevention of CTS. Methods: From Nov.5th to Nov.19th, 2017, 446 workers in an automobile factory whose work age was above one year participate in questionnaires by cluster sampling. Chi square test and multifactor logistics regression analysis were used to analyze the factors related to the occurrence of CTS pain symptoms in workers. Results: The incidence of CTS pain among workers in this automobile factory was 20.8%. Working in the same position for a long time (OR=2.137, 95% CI:1.183-3.862) and unable to work reasonably because of uncomfortable posture (OR =2.067, 95% CI: 1.075-3.974) were identified as the risk factors of CTS pain symptoms by multifactor logistics regression analysis. Working age (OR=0.537, 95%CI:0.311-0.926) and work break (OR= 0.489, 95% CI: 0.282-0.849) were identified as the benefit factors of CTS pain symptoms. Conclusion: The incidence of CTS pain in automobile manufacturing workers is related to the posture in the process of labor . Effective ergonomic interventions should be carried out to prevent the occurrence of CTS pain in automobile manufacturing workers.

[Overview of resistance mechanisms in Campylobacter]

Campylobacter is a major cause of food-borne gastroenteritis worldwide. While mortality is low when people was infected with Campylobacter, morbidity imparted by post-infectious sequelae such as Guillain-Barré syndrome and irritable bowel syndrome is significantly noteworthy. Although fluoroquinolones and macrolides were the first line drug for the treatment of Campylobacter infections, there is a tough challenge in clinical treatment with high antimicrobial resistant rate and multi antimicrobial resistance arise. Based on the latest literature acquired in this work, we have chosen five classes of antibiotics always used in clinical, and discussed antibiotic resistance mechanisms and transmission of Campylobacter, in order to provide proper therapy both in the veterinary and human populations, and support basis data for the development of new drugs.

Early development of vasogenic edema in experimental cerebral fat embolism in cats: correlation with MRI and electron microscopic findings

RATIONALE AND OBJECTIVES

To evaluate the magnetic resonance imaging and electron microscopic findings of the hyperacute stage of cerebral fat embolism in cats and the time needed for the development of vasogenic edema.

METHODS

Magnetic resonance imaging was performed at 30 minutes (group 1, n = 9) and at 30 minutes and 1, 2, 4, and 6 hours after embolization with triolein (group 2, n = 10). As a control for group 2, the same acquisition was obtained after embolization with polyvinyl alcohol particles (group 3, n = 5). Magnetic resonance images were analyzed qualitatively and quantitatively. Electron microscopic examination was done in all cats.

RESULTS

In group 1, the lesions were iso- or slightly hyperintense on T2-weighted (T2W) and diffusion-weighted (DWIs) images, hypointense on the apparent diffusion coefficient (ADC) map image, and markedly enhanced on the gadolinium-enhanced T1-weighted images (Gd-T1WIs). In group 2 at 30 minutes, the lesions were similar to those in group 1. Thereafter, the lesions became more hyperintense on T2WIs and DWIs and more hypointense on the ADC map image. The lesions were enhanced on Gd-T1WIs at all acquisition times. In group 3, the lesions showed mild hyperintensity on T2WIs at 6 hours but hypointensity on the ADC map image from 30 minutes, with a tendency toward a greater decrease over time. The lesions were not enhanced on Gd-T1WIs at any time point. Electron microscopic findings revealed discontinuity of the capillary endothelial wall, perivascular and interstitial edema, and swelling of glial and neuronal cells in groups 1 and 2. Cellular swelling and interstitial edema were more prominent in group 2. In group 3, interstitial edema was seen; however, discontinuity of the endothelial wall was absent.

CONCLUSIONS

The lesions were hyperintense on T2WIs and DWIs, hypointense on the ADC map image, and enhanced on Gd-T1WIs. On electron microscopy, the lesions showed cytotoxic and vasogenic edema with disruption of the blood-brain barrier. Vasogenic edema seems to develop within 30 minutes in cerebral fat embolism in cats.

NisP is related to nisin precursor processing and possibly to immunity in Lactococcus lactis

In this study, a plasmid was integrated into nisP, creating the first defined mutation in a nisin biosynthetic gene. The mutant strain secreted fully modified nisin with the N-terminal leader still attached. The presence of the leader was confirmed by N-terminal sequencing of the purified precursor. The dehydration and lanthionine formation of the precursor were already completed as active nisin could be formed by cleaving the leader from the inactive precursor by a trypsin treatment or by incubation with wild type cells. Nisin immunity of the NisP mutant strain was lowered to about 10% of the wild type immunity. The results show that NisP is needed fro precursor processing and for development of high immunity of nisin.

Sequencing with the large fragment of DNA polymerase I from Bacillus stearothermophilus

The large fragment of DNA polymerase I, isolated from Bacillus stearothermophilus, was used for dideoxy sequencing. This heat-stable enzyme permits performing sequencing reactions at high temperature to melt secondary structure and results in uniform band intensities and low background on the autoradiogram. The enzyme can be used in the standard Sanger one-step protocol or in a two-step protocol which separates the labeling reaction from the elongation-termination reaction. The enzyme can be used in double-stranded sequencing. 35S-labeled nucleotides may be used instead of 32P-labeled nucleotides. Both 7-deaza-dGTP and dITP can be used during the reaction in order to minimize band compression on the gel. Results presented here indicate that this enzyme should be a useful tool for sequence determination.

The significance of new abnormal isoenzymes of 5'-nucleotide phosphodiesterase in the diagnosis of human liver cancer

In 1986, we reported that abnormal 5'-nucleotide phosphodiesterase (5'-NP) (oligonucleate: 5'-nucleotidohydrolase, EC 3.1.4.1) isoenzymes (5'-NP I and 5'-NP V + VI) were observed in the serum of patients with liver cancer. The results of the present study show that the 5'-NP I positivity rate is 99.2% (234/236), specificity 74.9%; and the 5'-NP V + VI positivity rate is 77.5% (183/236), specificity 95.3% in liver cancer. 5'-NP I positivity rate is 86.7% (13/15) and 5'-NP V + VI positivity rate is 46.7% (7/15) in metastatic liver cancer. These 3 abnormal isoenzyme bands were all present in the serum of 6 patients with liver cancer before radical resection and disappeared after successful resection, but they were all present in the serum of 6 other liver cancer patients before and after palliative operation. In 2 cases of small liver cancer (diameter less than 4cm), 5'-NP I and 5'-NP V + VI were strongly positive. It may be considered that the new 5'-NP abnormal isoenzyme bands are specific markers and will be useful for diagnosis of human liver cancer.

Heat-stable DNA polymerase I large fragment resolves hairpin structure in DNA sequencing

A heat-stable large fragment was obtained by subtilisin digestion of DNA polymerase, prepared from Bacillus stearothermophilus. The dideoxy sequencing method, combined with the use of M13 vector has proved to be the most powerful one for obtaining the sequences of large genomes. However, the hairpin structure formed along the single-stranded DNA template often prevents the DNA polymerase from moving on, with the result that no sequence information can be obtained. The heat-stable large fragment that we have obtained has proved to be the most active at 65 degrees C. When the sequencing reaction was carried out at this temperature, the hairpin structure was resolved and the sequencing gels obtained were satisfactory.

New abnormal isoenzyme of 5'-nucleotide phosphodiesterase in the serum of human hepatoma

5'-nucleotide phosphodiesterase (5'-NP) isoenzymes were separated from the serum of human primary liver cancer (PLC) patients by 4-20% tubular polyacrylamide gel gradient electrophoresis. Electrophoresis showed 11 isoenzymes in which bands I, V and VI (from anode to cathode) were all absent in 125 normal control sera; bands V and VI were detectable in 31(73.8%) of 42 patients with PLC, but absent in 70 cases of other diseases. Bands V and VI may represent specific isoenzyme bands of PLC, comprising a new addition to the markers used in the diagnosis of this disease. By the same method, it was also found that the abnormal serum isoenzyme bands of PLC correspond to those found in the cord blood sera of the newborn and fetus. These abnormal isoenzymes diminish gradually after birth and all disappear when children reach the age of 10.

Restriction endonucleases from three strains of Haemophilus influenzae

The restriction endonucleases, Hin P1 I1), Hin S1 I and Hin S2 I are isolated from three strains of Haemophilus influenzae respectively. By polymin P treatment, ammonium sulphate, precipitation and column chromatography on phosphocellulose and on heparin-Sepharose Hin P1 I is partially purified. No contaminating deoxyribonuclease activities have been detected in this purified enzyme preparation. The fact that the digestion patterns of Hin P2 I and Hha I on phage lambda, plasmids ColE1 an pBR 322 DNAs are identical that they are isoschizomers but theri splitting sites are different. The banding patterns of Hin S1 I and Hin S2 I are also the same as that of Hha I.