Association Between Long-Term Exposure to Ambient Air Pollution and the Risk of Mild Cognitive Impairment in a Chinese Urban Area: A Case-Control Study

Background

As a prodromal stage of dementia, significant emphasis has been placed on the identification of modifiable risks of mild cognitive impairment (MCI). Research has indicated a correlation between exposure to air pollution and cognitive function in older adults. However, few studies have examined such an association among the MCI population inChina.

Objective

We aimed to explore the association between air pollution exposure and MCI risk from the Hubei Memory and Aging Cohort Study.

Methods

We measured four pollutants from 2015 to 2018, 3 years before the cognitive assessment of the participants. Logistic regression models were employed to calculate odds ratios (ORs) to assess the relationship between air pollutants and MCI risk.

Results

Among 4,205 older participants, the adjusted ORs of MCI risk for the highest quartile of PM2.5, PM10, O3, and SO2 were 1.90 (1.39, 2.62), 1.77 (1.28, 2.47), 0.56 (0.42, 0.75), and 1.18 (0.87, 1.61) respectively, compared with the lowest quartile. Stratified analyses indicated that such associations were found in both males and females, but were more significant in older participants.

Conclusions

Our findings are consistent with the growing evidence suggesting that air pollution increases the risk of mild cognitive decline, which has considerable guiding significance for early intervention of dementia in the older population. Further studies in other populations and broader geographical areas are warranted to validate these findings.

Systematic sequential therapy for ex vivo liver resection and autotransplantation: A case report and review of literature

BACKGROUND

Perihilar cholangiocarcinoma (pCCA) is a highly malignant tumor arising from the biliary tree. Radical surgery is the only treatment offering a chance of long-term survival. However, limited by the tumor's anatomic location and peri-vascular invasion, most patients lose the chance for curative treatment. Therefore, more methods to increase the resectability of tumors as well as to improve outcomes are needed.

CASE SUMMARY

A 68-year-old female patient had a hepatic hilar mass without obvious symptoms. Laboratory results showed hepatitis B positivity. Magnetic resonance imaging indicated that the mass (maximum diameter: 41 mm) invaded the left and right branches of the main portal vein, as well as the middle, left and right hepatic veins; enlarged lymph nodes were also detected in the hilum. The patient was diagnosed with pCCA, and the clinical stage was determined to be T4N1M0 (stage IIIC). Considering the tumor's anatomic location and vascular invasion, systematic conversion therapy followed by ex vivo liver resection and autotransplantation (ELRA) was determined as personalized treatment for this patient. Our original systemic sequential therapeutic strategy (lenvatinib and tislelizumab in combination with gemcitabine and cisplatin) was successfully adopted as conversion therapy because she achieved partial response after three cycles of treatment, without severe toxicity. ELRA, anastomotic reconstruction of the middle hepatic vein, right hepatic vein, root of portal vein, inferior vena cava and right hepatic artery, and lymph node dissection were performed at one month after systemic therapy. Pathological and immunohistochemical examination confirmed the diagnosis of pCCA with lymph node metastasis. Although the middle hepatic vein was partially obstructed four months later, hepatic vein stent implantation successfully addressed this problem. The patient has survived for 22 mo after the diagnosis, with no evidence of recurrence or metastasis.

CONCLUSION

An effective therapeutic strategy for conversion therapy greatly increases the feasibility and efficiency of ELRA.

Synthesis of peptides of Carapax Trionycis and their inhibitory effects on TGF-β1-induced hepatic stellate cells

We previous identified the antifibrotic active ingredients from Carapax Trionycis as two peptides. Here, we synthesized these two peptides (peptide 1 and peptide 2) by a solid phase method and examined their effects on proliferation and activation of cultured hepatic stellate cells (HSC) which are the main ECM (extracellular matrix)-producing cells in fibrosis progression. We demonstrated that peptide 1 and peptide 2 significantly reduced HSC proliferation and activation in a dose dependent manner. Further, peptide 1 and peptide 2 could interfere with TGF-signaling by down-regulating Smad 3 phosphorylation. Thus, these synthetic peptides of Carapax Trionycis could inhibit proliferation and activation of HSC and might be used as a candidate for treatment of liver fibrosis.

Large-scale mitochondrial DNA deletions in weak goslings

1. Evidence has accumulated in mammals to support the idea that mitochondrial DNA (mtDNA) deletions and mutations might contribute to ageing and reproductive failure. White Roman geese were monitored to evaluate the effect of large-scale deletions of mtDNA in an avian species. 2. A total of 340 samples from 114 dead embryos, 111 weak goslings, and 115 normal goslings were used in this experiment. The regions of these two large-scale mtDNA deletions, ΔmtDNA6829 and ΔmtDNA6992, were between the COI and ND5 genes. A 3·6% (4 out of 111) positive sample was detected in the weak goslings. In contrast, no large-scale mitochondrial DNA deletions were detected in either the dead embryos (0 out of 114) or the normal goslings (0 out of 115). 3. Large-scale mtDNA deletions may be a factor causing weak goslings.

The origin of the white Roman goose

In order to avoid interference from nuclear copies of mitochondrial DNA (numts), mtDNA of the white Roman goose (domestic goose) was extracted from liver mitochondria. The mtDNA control region was amplified using a long PCR strategy and then sequenced. Neighbor-joining, maximum parsimony, and maximum-likelihood approaches were implemented using the 1,177 bp mtDNA control region sequences to compute the phylogenetic relationships of the domestic goose with other geese. The resulting identity values for the white Roman geese were 99.1% (1,166/1,177) with western graylag geese and 98.8% (1,163/1,177) with eastern graylag geese. In molecular phylogenetic trees, the white Roman goose was grouped in the graylag lineage, indicating that the white Roman goose came from the graylag goose (Anser anser). Thus, the scientific name of the white Roman goose should be Anser anser 'White Roman.'

Biodelignification of rice straw by Phanerochaete chrysosporium in the presence of dirhamnolipid

Lignin degradation by white-rot fungi has received considerable attention as a means for reducing accumulation of lignocellulosic wastes in the environment. The stimulatory effect of surfactants on fungal lignocellulose bioconversion also has attracted wide interest. In this study the influence of dirhamnolipid biosurfactant on biodegradation of rice straw by Phanerochaete chrysosporium was investigated. It was shown that the biodelignification process of rice straw can be significantly enhanced by the presence of dirhamnolipid biosurfactant. In particular, the dirhamnolipid at the concentration of 0.007% increased the peak activity of lignin peroxidase (LiP) by 86% without affecting the manganese peroxidase (MnP) activity. The water-soluble organic carbon (WSOC) contents in the straw substrates as well as the microbial growth and activity were effectively improved by dirhamnolipid, while the degradation rate of lignin increased by 54% with dirhamnolipid of 0.007%. Observed chemical structural and morphological changes showed that the straw substrates were delignified in the presence of dirhamnolipid with the formation of terrace-like fragments separated from the inner cellular fibers and the release of simple compounds. Variation partitioning analysis revealed that the dirhamnolipid addition induced a significant straw biodelignification which explained 22.1% (P = 0.013) of the variance.

Troponin T measurement can predict persistent left ventricular dysfunction in peripartum cardiomyopathy

OBJECTIVE

To determine whether measurement of cardiac troponin T (cTnT) concentration in newly diagnosed peripartum cardiomyopathy (PPCM) can be used to predict persistent left ventricular dysfunction after a 6-month follow-up.

PATIENTS AND METHODS

This was a prospective, multiple-centre clinical trial that studied 106 patients with newly diagnosed PPCM surviving over 6 months. cTnT concentration was measured within 2 weeks of the onset of PPCM.

RESULTS

Serum cTnT concentration was negatively correlated with left ventricular ejection fraction (LVEF) at follow-up (LVEF, r = -0.518, p = 0.0001). Analysis by receiver operator characteristic curve yielded an area under the curve of 0.764 (95% CI 0.669 to 0.860, p = 0.0001, vs null hypothesis value 0.5) for cTnT, and a cTnT concentration cut off of >0.04 ng/ml, predicting persistent left ventricular dysfunction with a sensitivity of 54.9% and a specificity of 90.9%. Among 106 recruited patients, there were 33 patients with cTnT concentrations >0.04 ng/ml and 73 patients with cTnT concentrations < or =0.04 ng/ml. After a 6-month follow-up, there was significantly smaller LVEF (35.42% (13.04% vs 50.16% (10.48%, p = 0.0001) and more persistent left ventricular dysfunction (84.8% vs 31.5%, OR = 12.17 (95% CI 4.17 to 35.57), p = 0.001) in patients with cTnT >0.04 ng/ml than in patients with cTnT < or =0.04 ng/ml.

CONCLUSION

Serum cTnT concentration measured within 2 weeks of the onset of PPCM was correlated negatively with LVEF at follow-up. This marker offers a simple, quick, inexpensive, non-invasive method for predicting a persistent LVEF of < or =50%. A cTnT concentration of >0.04 ng/ml predicted persistent left ventricular dysfunction with a sensitivity of 54.9% and a specificity of 90.9%.

Comparison of rate control and rhythm control in patients with atrial fibrillation after percutaneous mitral balloon valvotomy: a randomised controlled study

OBJECTIVE

To compare rate control and rhythm control strategies in patients with atrial fibrillation (AF) after percutaneous mitral balloon valvotomy (PMV).

METHODS

183 patients with AF after successful PMV, with AF duration <or= 12 months and post-PMV left atrial (LA) size <or= 45 mm, were studied in a prospective, randomised trial. The primary end point was improvement in AF-related symptoms. Secondary study end points were 6 min walk tests, quality of life (QOL), normalisation of LA size, number of hospital admissions and duration of hospital stay.

RESULTS

Over one year, 2% patients in the rate control group had sinus rhythm, as compared with 96% of patients in the rhythm control group (p < 0.001). A greater proportion of patients reported improvement in symptoms in the rhythm control group than in the rate control group (p < 0.0001 at every visit time). Walking distance in a 6 min walk test, QOL and LA size normalisation were better in the rhythm control group than in the rate control group. The strategy of rhythm control was associated with similar numbers of hospital admissions but with longer duration of hospital admissions. Drug-related side effect did not differ between the rate control and rhythm control groups. During the follow-up period, no patients in either group had embolic or transitory ischaemic neurological events.

CONCLUSIONS

In patients with AF after PMV, AF duration <or= 12 months and post-PMV LA size <or= 45 mm, sinus rhythm was easy and safe to achieve and maintain. Moreover, patients benefited from restoration and maintenance of sinus rhythm in terms of improved AF-related symptoms, 6 min walk tests and QOL, and of LA size normalisation. Rhythm control should therefore be considered as the preferred initial therapy for this group of patients. The optimal strategy to treat AF after PMV should be individualised.

Effects of percutaneous electrical stimulation on peripheral nerve regeneration using silicone rubber chambers

The purpose of this study was to determine whether 0.8-1 mA, 2 Hz of percutaneous electrical stimulation could affect the regeneration of a 10-mm gap of rat sciatic nerve created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes. Six weeks after implantation, though the group receiving the electrical stimulation had a lower success percentage of regeneration (57%) compared with the controls receiving no stimulation (70%), quantitative histology of the successfully regenerated nerves revealed that the mean values of the axon density, blood vessel number, blood vessel area, and percentage of blood vessel area in total nerve area in the group with the electrical stimulation were all significantly larger than those in the controls (p < 0.05). These results showed that the electrical stimulation could elicit rehabilitating effects on the regenerated nerves.

[Analyses of chromosomal karyotypes and cytogenetic variations of animal cell lines]

After the master cell stock(mcs) and working cell bank of more than 30 different strains of 7 animal kidney cell lines (F-81 or CRFK cell line, MDCK cell line, Vero or Vero-2 cell line, MA-104 cell line and BHK-21 cell line) were established in China, the chromosomal number variations and structural aberrations of the above lines, primary feline or canine kidney cell (FKC or CKC) and HeLa cell line were investigated and their karyotypes of routine or Giemsa chromosomal bands were analyzed. The carcinogenesis or tumorigenicity testing of these cells in about 700 nude mice and for colony formation in soft agar (SA) and for agglutination under different concentration of plant lectins was carried out. Both tumorigenicity-negative strains of F-81, CRFK, Vero or Vero-2 lines and very-low-tumorigenicity strains of MDCK line were successfully selected and evaluated for the production of canine or feline combination viral vaccines, which are free of infectious agents, and described with respect to cytogenetic characteristics and tumorigenicity. Rate of modal chromosome number represents the ratio of cell number having modal chromosome number to all the split cell number analyzed at random. Rate of difference represents the ratio of difference of the rate of modal chromosome number between mcs (master cell stock) + n and mcs passages. The chromosomal analysis results showed that the ratio of difference of the rate of modal chromosome number between mcs + n and mcs passages was not more than 5%-15% and the structure aberrations was generally 0%-3%, not more than 5%-10%, thus the hereditary character of cell lines is comparatively stable without significant difference between different passages. The genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species specific. Experimental models were established for the researches on the prevention and prophylaxis of malignant tumors or cancers and their genetically biological characteristics. Tests showed that there was correlation among cell line chromosome number variations, anchorage independence in soft agar, agglutination under plant lectins and tumor-forming ability in nude mice. Since testing in vitro is more economic, simpler, faster, and is thought to be reliable, we recommend plant lectins followed by SA or analysis of karyotypes as the initial means for monitoring tumorigenicity of animal cell line in nude mice.

Apoptosis of bovine granulosa cells after serum withdrawal is mediated by Fas antigen (CD95) and Fas ligand

Ovarian follicular atresia occurs by apoptosis of granulosa and theca cells. The Fas antigen (Fas), a cell surface receptor that triggers apoptosis when activated by Fas ligand (FasL), may be involved in this process. A possible role of the Fas pathway in mediating serum withdrawal-induced apoptosis of granulosa cells was examined. Granulosa cells collected from 5- to 10-mm bovine follicles were cultured in DMEM-F12 containing serum for 3 days, deprived of serum, and live cells were counted at various times after serum withdrawal. Cell death increased significantly 6 h after serum withdrawal (21% +/- 7%; P: < 0.05 vs. 0 h) and continued to increase until 24 h (43% +/- 6%). No further increases in cell death were observed through 72 h. Detection of the translocation of phosphatidylserine to the outer surface of the cell membrane by annexin V binding indicated that cells died by apoptosis. Quantitative reverse transcriptase-polymerase chain reaction assays showed no changes in Fas mRNA levels but a 4.7-fold increase in FasL mRNA 3 h after serum withdrawal (P: < 0.05 vs. 0 h). FasL mRNA remained elevated through 24 h and returned to basal levels at 48 h. Immunohistochemical staining showed that both Fas and FasL protein increased on the cell surface within 3 h and remained elevated through 12 h (the last time point tested). Binding of FasL to Fas was blocked with two reagents that bind to the extracellular domain of FasL: an anti-FasL antibody and Fas:Fc, a chimeric protein consisting of the Fc portion of human immunoglobulin G and the extracellular domain of human Fas. Cell death 24 h after serum withdrawal was reduced 55% +/- 10% and 34% +/- 12% by anti-FasL antibody and Fas:Fc, respectively (P: < 0.05 vs. no blocking protein). In conclusion, serum withdrawal-induced apoptosis of bovine granulosa cells is mediated at least partially by Fas/FasL interactions. These results are consistent with a potential role of Fas in an autocrine or paracrine pathway to trigger ovarian follicular atresia.

Peripheral nerve regeneration using silicone rubber chambers filled with collagen, laminin and fibronectin

A 10 mm gap of rat sciatic nerve was created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes filled with an extracellular gel containing collagen, laminin and fibronectin. Empty silicone rubber tubes were used as controls. Six weeks after implantation, all extracellular elements were completely degraded and absorbed, and 90% of the animals from the extracellular gel group exhibited regeneration across the nerve gaps, whereas only 60% in the control group. Both qualitative and quantitative histology of the regenerated nerves revealed a more mature ultrastructural organization with 28% larger cross-sectional area and 28% higher number of myelinated axons in the extracellular gel group than the controls. These results showed that the gel mixture of collagen, laminin and fibronectin could offer a suitable growth medium for the regeneration of axons.

Gender determination in single bovine blastomeres by polymerase chain reaction amplification of sex-specific polymorphic fragments in the amelogenin gene

A sensitive technique for the sexing of bovine embryos was developed using polymerase chain reaction (PCR) amplification of the bovine amelogenin (bAML) gene on the X- and Y-chromosomes of Holstein dairy cattle. Cloning and DNA sequencing showed a 45.1% homology between the fifth intron of the bAML-X and bAML-Y gene with multiple deletions. A pair of sex-specific primers was designed to allow amplification of a single fragment of 467-bp from the X-chromosome of female cattle and two fragments of 467-bp and 341-bp from the X- and Y-chromosomes of male cattle. The primers were successfully applied to bovine sexing from single blastomeres isolated from day-6 to day-7 cow embryos by direct cell lysis and PCR. Our protocol of embryo sexing should be applicable to the diagnosis of defective genes in vitro in human embryos and in other domestic or recreational animals.

Carcase composition of Taiwan simulated native chickens

This study investigated the carcase composition of Taiwan simulated native chickens at different stages of growth. The results indicated that the carcases of male chickens exhibited significantly larger protein mass and water mass than those of females during weeks 7 to 20; as was the ash mass during weeks 8 to 20. However, the fat mass of the carcases of female chickens was larger than that of males during weeks 14 to 20. Separate regression equations were derived for the relationship between protein mass, fat mass, ash mass and water mass and both carcase weight and age of both male and female chickens.

[Treatment of experimental ischemic cerebral lactic acidosis in rats with dichloroacetate]

In the cerebral ischemic pathophysiologic mechanism, lactic acidosis is a important factor to exacerbate cerebral damage. Our research showed that the lactic level of cerebral cortex in rats increased rapidly after the focal cerebral ischemia or during blood reperfusion after cerebral ischemia, 26.99 +/- 5.89 and 28.63 +/- 5.08 mumol/g brain wight respectively, it exacerbated significantly brain edema and pathological damage. The lactic level decreased rapidly to treat with dichloroacetate (50 mg/kg body weight) after cerebral ischemia or during blood reperfusion, 14.11 +/- 2.06 and 13.23 +/- 1.71 mumol/g brain wight respectively, brain edema and pathology improved significantly. It suggested that dichloroacetate might across blood-brain barrier into the cerebral ischemic region and lowered lactic level, improved brain internal environment, relieved cerebral damage after focal cerebral ischemia or during blood reperfusion. It may improve the prognosis of patient with ischemic cerebral vascular disease to be treated with dichloroacetate early.

[Cerebrovascular disease in rural areas of Sichuan]

The prevalence ratio, incidence and mortality rates from cerebrovascular disease (CVD) among 41,232 subjects, in rural areas of Sichuan, People's Republic of China, were investigated and various suspect risk factors to stroke were evaluated. The prevalence ratio of CVD was 266.10/100,000 population; annual incidence rate was 179.86/100,000 population; annual mortality rate was 153.02/100,000 population. The main risk factors were hypertension, heart diseases, sclerotic findings and TIAs. It was characterized by higher incidence, shorter course, higher mortality of stroke in rural area.

Synthesis and turnover of protein-bound Nt-methylhistidine in cultured vascular smooth muscle cells

Rabbit aortic smooth muscle cells cultured for 14 days in second passage produce significant amounts of protein-bound radioactive Nt-methylhistidine when pulsed with radiolabelled histidine. Much of the radioactive Nt-methylhistidine is located in the actin synthesized by these cells. Pulse chase data also suggest this newly synthesized Nt-methylhistidine disappears from the cell layer at two distinctly different rates: one with a half-life of 2.4 days, and the other with a half-life of approximately 17 days. Radioactive Nt-methylhistidine to histidine ratio reaches a maximum approximately 8 days following the 1-day [14C]histidine pulse. During the initial 15-day chase period, there is a substantial net accumulation of total Nt-methylhistidine in the culture flasks. The data presented in this communication indicate that methods to evaluate Nt-methylhistidine synthesis and disappearance in cultures are feasible when radiolabelled histidine is employed.

Waveform feature extraction based on tauberian approximation

A technique is presented for feature extraction of a waveform y based on its Tauberian approximation, that is, on the approximation of y by a linear combination of appropriately delayed versions of a single basis function x, i.e., y(t) = ¿M i = 1 aix(t - ¿i), where the coefficients ai and the delays ¿i are adjustable parameters. Considerations in the choice or design of the basis function x are given. The parameters ai and ¿i, i=1, . . . , M, are retrieved by application of a suitably adapted version of Prony's method to the Fourier transform of the above approximation of y. A subset of the parameters ai and ¿i, i = 1, . . . , M, is used to construct the feature vector, the value of which can be used in a classification algorithm. Application of this technique to the classification of wide bandwidth radar return signatures is presented. Computer simulations proved successful and are also discussed.

A theory of necrotaxis

A mathematical theory for the motion of polynuclear leukocytes after the laser irradiation of a red blood cell is derived and compared with the measured movement of a number of cells. An estimate is made on the diffusion constant and the molecular size for the unknown material which communicates the information on the irradiation of the red blood cell to the leukocyte.