Preliminary Study on the Protective Effects and Molecular Mechanism of Procyanidins against PFOS-Induced Glucose-Stimulated Insulin Secretion Impairment in INS-1 Cells

This study aimed to investigate the effects of perfluorooctanesulfonic acid (PFOS) exposure on glucose-stimulated insulin secretion (GSIS) of rat insulinoma (INS-1) cells and the potential protective effects of procyanidins (PC). The effects of PFOS and/or PC on GSIS of INS-1 cells were investigated after 48 h of exposure (protein level: insulin; gene level: glucose transporter 2 (Glut2), glucokinase (Gck), and insulin). Subsequently, the effects of exposure on the intracellular reactive oxygen species (ROS) activity were measured. Compared to the control group, PFOS exposure (12.5, 25, and 50 μM) for 48 h had no significant effect on the viability of INS-1 cells. PFOS exposure (50 μM) could reduce the level of insulin secretion and reduce the relative mRNA expression levels of Glut2, Gck, and insulin. It is worth noting that PC could partially reverse the damaging effect caused by PFOS. Significantly, there was an increase in ROS after exposure to PFOS and a decline after PC intervention. PFOS could affect the normal physiological function of GSIS in INS-1 cells. PC, a plant natural product, could effectively alleviate the damage caused by PFOS by inhibiting ROS activity.

[Clinical features and influencing factors of long-term prognosis in patients with tuberculous meningitis]

Objective: To investigate the clinical features and influencing factors of long-term prognosis of tuberculous meningitis(TBM), and to provide a recommendation for treatment and early intervention of TBM. Methods: Clinical data of TBM patients were retrospectively collected at Peking Union Medical College Hospital from January 2014 to December 2021. Patients who were followed-up more than one year were divided into two groups according to modified Rankin Scale (mRS). Risk factors associated with long-term prognosis were analyze by conditional logistic stepwise regression. Results: A total of 60 subjects were enrolled including 33 (55%) males and 27 (45%) females with age 15-79 (44.5±19.8) years. There were 30 cases (50%) complicated with encephalitis, 21 cases (35%) with miliary tuberculosis. The diagnosis was microbiologically confirmed in 22 patients (36.7%), including 5 cases (22.7%, 5/22) by acid-fast staining, 8 cases (36.4%, 8/22) by Mycobacterium tuberculosis (MTB) culture, and 20 cases (90.9%, 20/22) by molecular biology. The median follow-up period was 52(43, 66 ) months in 55 cases surviving more than one year. Among them, 40 cases (72.7%) were in favorable group (mRS 0-2) and 15 cases (27.3%) were in unfavorable group (mRS 3-6) with poor prognosis. The mortality rate was 20% (11/55). Elderly (OR=1.06, P=0.048 ) , hyponatremia(OR=0.81,P=0.020), high protein level in cerebrospinal fluid (CSF) (OR=3.32,P=0.033), cerebral infarction(OR=10.50,P=0.040) and hydrocephalus(OR=8.51,P=0.049) were associated with poor prognosis in TBM patients. Conclusions: The mortality rate is high in patients with TBM. Molecular biology tests improves the sensitivity and shorten the diagnosis time of TBM. Elderly, hyponatremia, high protein level in CSF, cerebral infarction and hydrocephalus are independent risk factors of long-term survival in TBM patients.

Mutagenicity of biodiesel or diesel exhaust particles and the effect of engine operating conditions

BACKGROUND

Changing the fuel supply from petroleum based ultra-low sulfur diesel (ULSD) to biodiesel and its blends is considered by many to be a viable option for controlling exposures to particulate material (PM). This is critical in the mining industry where approximately 28,000 underground miners are potentially exposed to relatively high concentrations of diesel particulate matter (DPM). This study was conducted to investigate the mutagenic potential of diesel engine emissions (DEE) from neat (B100) and blended (B50) soy-based fatty acid methyl ester (FAME) biodiesel in comparison with ULSD PM using different engine operating conditions and exhaust aftertreatment configurations.

METHODS

The DPM samples were collected for engine equipped with either a standard muffler or a combination of the muffler and diesel oxidation catalytic converter (DOC) that was operated at four different steady-state modes. Bacterial gene mutation activity of DPM was tested on the organic solvent extracts using the Ames Salmonella assay.

RESULTS

The results indicate that mutagenic activity of DPM was strongly affected by fuels, engine operating conditions, and exhaust aftertreatment systems. The mutagenicity was increased with the fraction of biodiesel in the fuel. While the mutagenic activity was observed in B50 and B100 samples collected from both light-and heavy-load operating conditions, the ULSD samples were mutagenic only at light-load conditions. The presence of DOC in the exhaust system resulted in the decreased mutagenicity when engine was fueled with B100 and B50 and operated at light-load conditions. This was not the case when engine was fueled with ULSD. Heavy-load operating condition in the presence of DOC resulted in a decrease of mutagenicity only when engine was fueled with B50, but not B100 or ULSD.

CONCLUSIONS

Therefore, the results indicate that DPM from neat or blended biodiesel has a higher mutagenic potency than that one of ULSD. Further research is needed to investigate the health effect of biodiesel as well as efficiency of DOC or other exhaust aftertreatment systems.

A laser-Compton scattering prototype experiment at 100 MeV linac of Shanghai Institute of Applied Physics

As a prototype of the Shanghai Laser Electron Gamma Source in the Shanghai Synchrotron Radiation Facility, an x-ray source based on laser-Compton scattering (LCS) has been installed at the terminal of the 100 MeV linac of the Shanghai Institute of Applied Physics. LCS x-rays are generated by interactions between Q-switched Nd:yttrium aluminum garnet laser pulses [with wavelength of 1064 nm and pulse width of 21 ns (full width at half maximum)] and electron bunches [with energy of 108 MeV and pulse width of 0.95 ns (rms)] at an angle of 42 degrees between laser and electron beam. In order to measure the energy spectrum of LCS x-rays, a Si(Li) detector along the electron beam line axis is positioned at 9.8 m away from a LCS chamber. After background subtraction, the LCS x-ray spectrum with the peak energy of 29.1+/-4.4|(stat)+/-2.1|(syst) keV and the peak width (rms) of 7.8+/-2.8|(stat)+/-0.4|(syst) keV is observed. Normally the 100 MeV linac operates with the electron macropulse charge of 1.0 nC/pulse, and the electron and laser collision repetition rate of 20 Hz. Therefore, the total LCS x-ray flux of (5.2+/-2.0) x 10(2) Hz can be achieved.

Induction of micronuclei in rat bone marrow by four model compounds

Studies have been performed to determine the dose and sampling time responses of micronuclei after Sprague-Dawley rats were treated with triethylenemelamine, mitomycin C. dimethylbenzanthracene, and vincristine by a single intraperitoneal injection. Three doses were tested for each compound. Animals were sacrificed 24, 48, and 72 h after chemical treatment. Slides prepared from the bone marrow were stained with May-Gruenwald and Giemsa stains. The number of micronucleated polychromatic erythrocytes among 2,000 polychromatic erythrocytes (PCEs) and the ratio of PCEs to normochromatic erythrocytes were determined for each animal. The results show that all four compounds cause micronucleus formation in rat bone marrow. The peak response sampling time, either 24 or 48 h posttreatment, is dependent on the chemical as well as the dose. In all cases, however, an increase in the micronucleated PCEs was detected 24 h after chemical treatment. These results seem to indicate that two sampling times, 24 and 48 h, may be adequate for the micronucleus assay using rat bone marrow cells.

Effect of tetrandrine on micronucleus formation and sister-chromatid exchange in both in vitro and in vivo assays

The genotoxicity of tetrandrine, a drug potentially useful for the treatment of silicosis, was studied using the micronucleus and the sister-chromatid exchange (SCE) assay systems. Cultured Chinese hamster lung (V79) cells were used for the in vitro micronucleus and sister-chromatid exchange studies. Mouse bone marrow was used for the in vivo micronucleus assay and mouse spleen cells for the in vivo/in vitro sister-chromatid exchange analysis. The results show that SCE levels in V79 and in spleen cells were significantly elevated by treatment with tetrandrine at doses above 0.08 mg/ml and 100 mg/kg bw, respectively. Increased tetradrine-induced SCE in vitro was metabolic activation dependent. Tetrandrine failed to induce micronuclei at any of the doses tested. A decrease of replicative index with an increase in the concentration of tetrandrine was found both in vitro and in vivo. These results indicate that tetrandrine is a weak indirect-acting genotoxicant.

Effects of artemether on peripheral T, B, T mu and T gamma lymphocytes in beagle dog

The effects of intramuscular injection of Artemether on peripheral T, B, T mu and T gamma lymphocytes in beagle dogs was investigated cytochemically. Doses used were 6, 19, and 32 MKD, respectively. Results showed that after injection of Artemether for 15 successive days, the T, B, and T mu lymphocytes of the 19 and 32 MKD groups were markedly reduced and the T gamma lymphocytes of all 3 dosage groups were decreased to zero. 28 days after cessation of the drug, T, T mu and T gamma lymphocytes had recovered to control levels, while the B lymphocytes of the 19 and 32 MKD groups remained markedly lower than those of the control groups. The differences and similarities of the effects on the peripheral T, B, T mu and T gamma lymphocytes produced by the 3 dosages of Artemether and the relationship between the changes of T, B lymphocytes and immunological function of beagle dogs are discussed.

[Studies on the surveillance and purifying measures for filariasis in controlled areas]

This paper reports the results of longitudinal surveillance of filariasis for 4 years in Jining City, Shandong, where the disease has been controlled. It showed that the microfilaremia rate dropped from 0.48% to 0.03% and no new case was found and the natural infective rate of the main vector mosquito Culex pipiens fell from 0.45% to 0.03% and no larva III was detected. The purifying measures should put emphasis on the management of migrating persons repeatedly examining and treating old microfilaremia cases, the border areas with high microfilaremia rate, as well as working out a plan to cure the advanced patients and mosquito control measures with special reference to construction of new village settlements.

A study of 11C-benzoate as a radiopharmaceutical for renal imaging

11C-benzoic acid prepared in a radiochemical purity over 90% was studied radiopharmacologically in mice and rabbits. The uptake of 11C-benzoate in ICR mice increased quickly. The ratio of kidney uptake rate to that in other organs reached values between 9 and 55 with a maximum at 10 min after i.v. injection. Gamma camera imaging of rabbits showed that uptake in the kidneys began at 2 min after injection and that activity began to appear in the bladder 4 min later. Rabbits with left renal artery ligature showed no uptake in the left kidney but the right kidney was imaged to the same extent as that of a rabbit without artery ligature. The kidney imaging of 11C-benzoic acid may be a useful method for renal diagnosis.

Pharmacology of radioiodinated hexadecenoic acid--a myocardial imaging agent

123I- and 131I-labeled hexadecenoic acid (IHDA, radiochemical purity over 92%, dissolved in 6% bovine serum albumin solution) was investigated in vivo. ICR mice were administered IHDA via the tail vein. Maximum myocardial uptake (27.3 +/- 5.1%) was reached about 0.5 min after the injection. The ratio of uptake in the heart to that in the lungs was 2.3, to that in liver 1.5 and to that in other organs 2.4 to 6.4. The dog myocardium was visualized distinctly within 3-5 min with a gamma camera after i.v. 131I-IHDA, and not interfered with by activities in the lungs, liver and other organs. The low blood levels at 20 min had little effect on the quality of the heart images.