Leukocyte telomere length mediates the association between cadmium exposure and cognitive function in US older adults

BACKGROUND

Long-term exposure to cadmium-polluted environments may lead to shortened leukocyte telomere length and cognitive decline. This study aims to investigate (1) the associations among blood cadmium levels, leukocyte telomere length, and cognitive function, and (2) the mediating role of leukocyte telomere length between blood cadmium levels and cognitive function among older adults in the United States.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002. Cadmium exposure level was assessed by measuring cadmium levels in blood samples. Leukocyte telomere length was measured by quantitative polymerase chain reaction, and cognitive function was measured by the digit symbol substitution test (DSST).

RESULTS

A total of 2185 older adults aged over 60 were included in this study, comprising 1109 (49.65%) males. Elevated blood cadmium levels were significantly associated with the risk of a decline in cognitive function (β = - 2.842, p = 0.018). Shorter leukocyte telomere lengths were significantly associated with a higher risk of a decline in cognitive function (β = 4.144, p = 0.020). The total indirect effect on the blood cadmium level and cognitive function via leukocyte telomere length was - 0.218 (p = 0.012). The mediation effect was estimated to be 0.218/2.084 × 100% = 10.46%.

CONCLUSION

The findings suggest that cadmium exposure may increase the risk of cognitive impairment by causing shortened leukocyte telomere length.

Nomogram Based on Clinical and Radiomics Data for Predicting Radiation-induced Temporal Lobe Injury in Patients with Non-metastatic Stage T4 Nasopharyngeal Carcinoma

AIMS

To use pre-treatment magnetic resonance imaging-based radiomics data with clinical data to predict radiation-induced temporal lobe injury (RTLI) in nasopharyngeal carcinoma (NPC) patients with stage T4/N0-3/M0 within 5 years after radiotherapy.

MATERIALS AND METHODS

This study retrospectively examined 98 patients (198 temporal lobes) with stage T4/N0-3/M0 NPC. Participants were enrolled into a training cohort or a validation cohort in a ratio of 7:3. Radiomics features were extracted from pre-treatment magnetic resonance imaging that were T1-and T2-weighted. Spearman rank correlation, the t-test and the least absolute shrinkage and selection operator (LASSO) algorithm were used to select significant radiomics features; machine-learning models were used to generate radiomics signatures (Rad-Scores). Rad-Scores and clinical factors were integrated into a nomogram for prediction of RTLI. Nomogram discrimination was evaluated using receiver operating characteristic analysis and clinical benefits were evaluated using decision curve analysis.

RESULTS

Participants were enrolled into a training cohort (n = 139) or a validation cohort (n = 59). In total, 3568 radiomics features were initially extracted from T1-and T2-weighted images. Age, D_max, D_1cc and 16 stable radiomics features (six from T1-weighted and 10 from T2-weighted images) were identified as independent predictive factors. A greater Rad-Score was associated with a greater risk of RTLI. The nomogram showed good discrimination, with a C-index of 0.85 (95% confidence interval 0.79-0.92) in the training cohort and 0.82 (95% confidence interval 0.71-0.92) in the validation cohort.

CONCLUSION

We developed models for the prediction of RTLI in patients with stage T4/N0-3/M0 NPC using pre-treatment radiomics data and clinical data. Nomograms from these pre-treatment data improved the prediction of RTLI. These results may allow the selection of patients for earlier clinical interventions.

Surgical anatomy of the submental artery perforator flap and assessment for application in postoperative reconstruction following oral cancer surgery: a prospective clinical study

The submental artery perforator flap (SMAPF) has an elongated pedicle, allowing good cosmetic outcomes to be achieved following oral reconstruction surgery. The improper dissection of perforators often leads to a vascular flap crisis. To avoid this, some surgeons choose to carry amounts of connective tissue around the pedicle. However the inclusion of connective tissue on the pedicle raises concerns about oncological safety. A surgical anatomical study of the submental vessel patterns and subdivisions of the cervical level I lymph nodes was conducted on 33 patients with primary oral cancer who underwent reconstruction with a SMAPF after tumour resection. The variations in vessels and cervical level I lymph nodes observed during SMAPF harvesting were recorded and analyzed. Two patterns of submental artery perforators and three patterns of submental veins were identified. The different characteristics of the lymph node distribution were elucidated for five subdivisions. All SMAPFs survived (n=33, 100%); however, two SMAPFs exhibited partial losses. The 3-year survival rate of patients was 84.5±6.4%, and there were no suspected flap-related recurrences. With detailed anatomical information on the vascular system and lymph node subdivision, SMAPFs are a reliable choice for postoperative reconstruction following oral cancer surgery, meeting the standards for oncological safety.

Treatment Strategy for Unruptured Intracranial Aneurysm in Elderly Patients: Coiling, Clipping, or Conservative?

An increasing number of unruptured intracranial aneurysms (UIAs) has been discovered in elderly patients in recent years, but the optimal treatment strategy for these patients remains controversial. We report our six-year experience treating UIAs in elderly patients (≥ 70 years old). A retrospective review was conducted of elderly patients who harbored UIAs treated by conservative observation, microsurgical clipping, or endovascular coiling between January 2009 and December 2014. The patients’ clinical and imaging information was recorded. Treating methods, procedure-related complications, imaging results, and clinical outcomes were analyzed. A total of 141 consecutive elderly patients with 166 UIAs were enrolled in our study. In all, 64 patients with 79 aneurysms were treated with coiling, and 14 patients with 14 aneurysms were treated with clipping. The remaining 63 patients with 73 aneurysms were placed under conservative observation. The average modified Rankin scale was 0.99 (range 0–6) in the full cohort after a mean follow-up of 50.4 months (range 0–70 months). There was no significant difference of modified Rankin scale in patients with UIAs treated by different methods. Multivariate analysis showed that age (p=0.030) and aneurysm size (p=0.011) were independent risk factors for unfavorable outcome of UIAs in the elderly. Patient age (p=0.010) and aneurysm size (p=0.020) were also significantly associated with unfavorable outcome of UIAs managed with observation initially. Our results indicated that endovascular coil embolization and clipping were both safe and effective treatment methods for UIAs in the elderly. Aggressive treatment for UIAs in elderly patients with risk factors of aneurysm rupture should be considered positively.

[Variation trend and significance of adult tonsil size and tongue position]

Objective:The aim of this study is to explore the changing trend and significance of adult tonsil size and tongue position by observing adults in different age groups. Method:Oropharyngeal cavities of 1 060 adults who undergoing health examination and had no history of tonsil surgery were observed. Friedman tongue position (FTP) and tonsil size (TS) were scored according to Friedman's criteria and results were statistic analyzed to evaluate their changing law and significance. Result: Mean FTP scores increased with age significantly（P <0.01）; FTP score in male was lower than that in female（P <0.01）. TS score significantly decreased with age（P <0.05）.The average score of TS had no statistical significance in different gender. Although there was no statistical significance, total score of FTP show an increasing trend with age（P >0.05）;Total scores of FTP were different between sexes（male 4.12±0.67，female 4.23±0.68，P <0.05）.BMI was not found to be statistically different when FTP scores, TS scores and total scores changed (P >0.05); but it showed an increasing trend with age（P <0.01）. Conclusion:Width of pharyngeal cavity in normal adults is always kept in certain stability, while it proves to be narrower in obese people. TS score and FTP score, which appear the opposite trend with age, can be thought as a major factor to keep a stable width of oral pharyngeal cavity.

Voltammetric behavior of vitamin B(2) on the gold electrode modified with a self-assembled monolayer of l-cysteine and its application for the determination of vitamin B(2) using linear sweep stripping voltammetry

The voltammetric behavior of Vitamin B(2) (VB(2)) has been studied at the gold electrode modified with a self-assembled monolayer of l-cysteine. The voltammetric responses are evaluated with respect experimental conditions, such as composition and pH of the supporting electrolyte, concentration of VB(2), accumulation potential and accumulation time. On basis of the voltammetric behavior a highly sensitive method is present for the determination of VB(2) by using linear sweep stripping volammetry. The method is suitable for the determination of VB(2) concentrations between 5.0x10(-11) and 5.0x10(-6) mol l(-1). And the detection limit can be reached to 2.5x10(-11) mol l(-1). The method is applied to determine the concentration of VB(2) in the tablets with satisfactory results.

Electrochemical and PM-IRRAS a glycolipid-containing biomimetic membrane prepared using Langmuir-Blodgett/Langmuir-Schaefer deposition

Differential capacitance, chronocoulometry, and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) measurements were used to characterize the structure and orientation of a DMPC + cholesterol + GM 1 (60:30:10 mol %) bilayer supported at a Au(111) electrode surface prepared using combined Langmuir-Blodgett/Langmuir-Schaefer (LB/LS) deposition. The electrochemical measurements indicate that the incorporation of ganglioside GM 1 into the membrane significantly improves the quality of the bilayer, reflected in the very low capacitance value of approximately 0.8 microF cm (-2). An analysis of the infrared data suggests that the incorporation of the glycolipid into the membrane changes both the orientation of the lipid acyl chains in the membrane and the hydration of the membrane, particularly with respect to the interfacial region of the lipids.

Controlled Site-Directed Assembly of Antibodies by Their Oligosaccharide Moieties onto APTES Derivatized Surfaces

A convenient and efficient method for the site-directed incorporation of aldehydes generated on the oligosaccharide moieties at the C-terminal of immunoglobulin (IgG) using NaIO4 oxidation reaction is explored as a means of ensuring controlled assembly of IgG antibodies onto aminopropyltriethoxylsilane (APTES) derivatized silicon wafer surfaces. The orientation and antigen binding capacity (AgBC) of site-directly assembled IgG antibodies on derivatized surfaces were investigated using atomic force microscopy (AFM) and enzyme immunoassay (EIA), respectively. A major difference in preferential orientation is observed when the incubation of derivatized surfaces with oxidized IgG molecules is compared in two different kinds of buffer solutions. We obtained the stable and homogeneous IgG layer without loss of the AgBC on the APTES derivatized surface using the controlled incubation condition. Copyright 1999 Academic Press.

Individual repeats of Drosophila Myb can function in transformation by v-Myb

The v-Myb protein binds to specific DNA sequences and can regulate gene expression. The DNA-binding domain of v-Myb contains the second and third of the three highly conserved tandem repeats found in c-Myb. In general, the ability of mutant forms of v-Myb to transform correlates with their ability to trans activate transcription. Two mutations within the DNA-binding domain of v-Myb which preserve DNA binding in vitro but fail to trans activate or transform have been described. These results suggested that this highly conserved domain might function in specific protein-protein interactions, as well as in DNA binding. We therefore tested the ability of a related protein domain from Drosophila melanogaster to substitute functionally for the homologous region of v-Myb. We found that either the second or third repeat of Drosophila Myb, but not both, could function in trans-activation and transformation by v-Myb. The hybrid containing both the second and third repeats of Drosophila Myb bound to DNA but failed to trans activate transcription either in the context of v-Myb or as a v-Myb-VP16 fusion protein. These results demonstrate that although the protein-DNA contacts made by the Myb repeats have been conserved during the evolution of animals, the protein-protein interactions have diverged.

The Myb DNA-binding domain is highly conserved in Dictyostelium discoideum

The c-myb proto-oncogene encodes a protein that is highly conserved among birds and mammals. The amino-terminal domain of c-Myb contains three imperfect tandem repeats of approximately 50 amino acids each. This domain is required for DNA binding and has also been conserved to varying degrees in invertebrates, plants and yeast. Given that myb-related genes appear to control cellular differentiation in a variety of eucaryotic systems, the presence of a myb gene in the cellular slime mold Dictyostelium discoideum might provide a tractable system for studying the role of myb in differentiation. Degenerate oligonucleotide primers encoding regions that are highly conserved in the vertebrate and Drosophila Myb DNA-binding domains were used to amplify a related domain from Dictyostelium genomic DNA, which was then used to isolate a genomic clone. The putative DNA-binding domain of Dictyostelium Myb is as closely related to vertebrate c-Myb as is Drosophila Myb (65% identity), whereas the known Myb-related proteins of plants and yeast are more distantly related. The conserved domain of Dictyostelium Myb is capable of binding to the same DNA sequence as the vertebrate and Drosophila Myb proteins. The remainder of the deduced amino acid sequence of Dictyostelium Myb shows no homology to the divergent domains of the known animal, plant and yeast Myb-related proteins. Evolutionary analysis implies that the duplications that generated the repeats of the Myb DNA-binding domain began prior to the divergence of animals, plants, cellular slime molds and yeast.

Comparative study with monospecific and monoclonal antibodies against a 65 K human cytomegalovirus protein

Immunofluorescence assay using monospecific and monoclonal antibodies to the 65 K major protein of human cytomegalovirus (HCMV) was carried out to monitor the expression of this protein in infected cells. Regardless of differences in the reactivity of the monoclonal antibodies, as determined by immunoblotting and immunofluorescent staining, all stained cytoplasmic inclusion bodies localized to the site of the HCMV-induced receptor for the Fc portion of IgG, suggesting that most of the 65 K major protein of HCMV colocalizes with the HCMV-induced FcR.