SARS-CoV-2 Infection Causes Heightened Disease Severity and Mortality in a Mouse Model of Down Syndrome.

Recent epidemiological studies suggest that individuals with Down syndrome are more susceptible to SARS-CoV-2 infection and have higher rates of hospitalization and mortality than the general population. However, the main drivers behind these disparate health outcomes remain unknown. Herein, we performed experimental infections with SARS-CoV-2 in a well-established mouse model of Down syndrome. We observed similar SARS-CoV-2 replication kinetics and dissemination in the primary and secondary organs between mice with and without Down syndrome, suggesting that both groups have similar susceptibilities to SARS-CoV-2 infection. However, Down syndrome mice exhibited more severe disease as defined by clinical features including symptoms, weight loss, pulmonary function, and survival of mice. We found that increased disease severity in Down syndrome mice could not be attributed solely to increased infectivity or a more dramatic pro-inflammatory response to infection. Rather, results from RNA sequencing suggested that differences in the expression of genes from other physiological pathways, such as deficient oxidative phosphorylation, cardiopulmonary dysfunction, and deficient mucociliary clearance in the lungs may also contribute to heightened disease severity and mortality in Down syndrome mice following SARS-CoV-2 infection.

Gross Hematuria Does not Affect the Selection of Nephrectomy Types for Clinical Stage 1 Clear Cell Renal Cell Carcinoma: A Multicenter, Retrospective Cohort Study.

PURPOSE: This study aimed to discuss the correlation between gross hematuria and postoperative upstaging (from T1 to T3a) in patients with cT1 clear cell renal cell carcinoma (ccRCC) and to compare oncologic outcomes of partial nephrectomy (PN) and radical nephrectomy (RN) in patients with gross hematuria. METHODS: A total of 2145 patients who met the criteria were enrolled in the study (including 363 patients with gross hematuria). The least absolute selection and shrinkage operator logistic regression was used to evaluate the risk factor of postoperative pathological upstaging. The propensity score matching (PSM) and stable inverse probability of treatment weighting (IPTW) analysis were used to balance the confounding factors. The Kaplan-Meier analysis and multivariate Cox proportional risk regression model were used to assess the prognosis. RESULTS: Gross hematuria was a risk factor of postoperative pathological upstaging (odds ratio [OR] = 3.96; 95% confidence interval [CI] 2.44-6.42; P < 0.001). After PSM and stable IPTW adjustment, the characteristics were similar in corresponding patients in the PN and RN groups. In the PSM cohort, PN did not have a statistically significant impact on recurrence-free survival (hazard ratio [HR] = 1.48; 95% CI 0.25-8.88; P = 0.67), metastasis-free survival (HR = 1.24; 95% CI 0.33-4.66; P = 0.75), and overall survival (HR = 1.46; 95% CI 0.31-6.73; P = 0.63) compared with RN. The results were confirmed in sensitivity analyses. CONCLUSIONS: Although gross hematuria was associated with postoperative pathological upstaging in patients with cT1 ccRCC, PN should still be the preferred treatment for such patients.

Identification of molecular subtypes and diagnostic model in clear cell renal cell carcinoma based on collagen-related genes may predict the response of immunotherapy.

Background: Collagen represents a prominent constituent of the tumor's extracellular matrix (ECM). Nonetheless, its correlation with the molecular subtype attributes of clear cell renal cell carcinoma (ccRCC) remains elusive. Our objective is to delineate collagen-associated molecular subtypes and further construct diagnostic model, offering insights conducive to the precise selection of ccRCC patients for immunotherapeutic interventions. Methods: We performed unsupervised non-negative matrix factorization (NMF) analysis on TCGA-KIRC samples, utilizing a set of 33 collagen-related differentially expressed genes (33CRDs) for clustering. Our analysis encompassed evaluations of subtype-associated differences in pathways, immune profiles, and somatic mutations. Through weighted gene co-expression network analysis (WGCNA) and four machine learning algorithms, two core genes were found and a diagnostic model was constructed. This was subsequently validated in a clinical immunotherapy cohort. Single cell sequencing analysis and experiments demonstrated the role of core genes in ccRCC. Finally, we also analyzed the roles of MMP9 and SCGN in pan-cancer. Results: We described two novel collagen related molecular subtypes in ccRCC, designated subtype 1 and subtype 2. Compared with subtype 1, subtype 2 showed more infiltration of immune components, but had a higher TIDE (tumor immunedysfunctionandexclusion) score and increased levels of immune checkpoint molecules. Furthermore, reduced prognosis for subtype 2 was a consistent finding in both high and low mutation load subgroups. MMP9 and SCGN were identified as key genes for distinguishing subtype 1 and subtype 2. The diagnostic model based on them could better distinguish the subtype of patients, and the differentiated patients had different progression free survival (PFS) in the clinical immunotherapy cohort. MMP9 was predominantly expressed in macrophages and has been extensively documented in the literature. Meanwhile, SCGN, which was overexpressed in tumor cells, underwent experimental validation, emphasizing its role in ccRCC. In various cancers, MMP9 and SCGN were associated with immune-related molecules and immune cells. Conclusion: Our study identifies two collagen-related molecular subtypes of ccRCC and constructs a diagnostic model to help select appropriate patients for immunotherapy.

Patients with high nuclear grade pT1-ccRCC are more suitable for radical nephrectomy than partial nephrectomy: a multicenter retrospective study using propensity score.

BACKGROUND: Partial nephrectomy (PN) is usually recommended for T1 stage clear cell renal cell carcinoma (ccRCC) regardless of the nuclear grades. However, the question remains unresolved as to whether PN is non-inferior to RN in patients with T1-ccRCC at higher risk of recurrence. In fact, we found that patients with high nuclear grades treated with PN had poorer prognosis compared with those treated with radical nephrectomy (RN). Therefore, this study was designed to evaluate the associations of PN and RN in the four nuclear grade subsets with oncologic outcomes. METHODS: A retrospective study was conducted in three Chinese urological centers that included 1,714 patients who underwent PN or RN for sporadic, unilateral, pT1, N0, and M0 ccRCC without positive surgical margins and neoadjuvant therapy between 2010 and 2019. Associations of nephrectomy type with local ipsilateral recurrence, distant metastases, and all-cause mortality (ACM) were evaluated using the Kaplan-Meier method and multivariable Cox proportional hazards regression models after overlap weighting (OW). RESULTS: A total of 1675 patients entered the OW cohort. After OW, in comparison to PN, RN associated with a reduced risk of local ipsilateral recurrence in the G2 subset (HR = 0.148, 95% CI 0.046-0.474; p < 0.05), G3 subset (HR = 0.097, 95% CI 0.021-0.455; p < 0.05), and G4 subset (HR = 0.091, 95% CI 0.011-0.736; p < 0.05), and resulting in increased five-year local recurrence-free survival rates of 7.0%, 17.9%, and 36.2%, respectively. An association between RN and a reduced risk of distant metastases in the G4 subset (HR = 0.071, 95% CI 0.016-0.325; p < 0.05), with the five-year distant metastases-free survival rate increasing by 33.1% was also observed. No significant difference in ACM between PN and RN was identified. CONCLUSIONS: Our findings substantiate that opting for RN, as opposed to PN, is more advantageous for local recurrence-free survival and distant metastases-free survival in patients with high nuclear grade (especially G4) pT1-ccRCC. We recommend placing a heightened emphasis on enhancing preoperative nuclear grade assessment, as it can significantly influence the choice of surgical plan. TRIAL REGISTRATION: This study was registered at Chinese Clinical Trial Registry (ID: ChiCTR2200063333).

Differential gene expression patterns between the head and thorax of Gynaephora aureata are associated with high-altitude adaptation.

Grassland caterpillars (Lepidoptera: Erebidae: Gynaephora) are important pests in alpine meadows of the Qinghai-Tibetan Plateau (QTP). These pests have morphological, behavioral, and genetic adaptations for survival in high-altitude environments. However, mechanisms underlying high-altitude adaptation in QTP Gynaephora species remain largely unknown. Here, we performed a comparative analysis of the head and thorax transcriptomes of G. aureata to explore the genetic basis of high-altitude adaptation. We detected 8,736 significantly differentially expressed genes (sDEGs) between the head and thorax, including genes related to carbohydrate metabolism, lipid metabolism, epidermal proteins, and detoxification. These sDEGs were significantly enriched in 312 Gene Ontology terms and 16 KEGG pathways. We identified 73 pigment-associated genes, including 8 rhodopsin-associated genes, 19 ommochrome-associated genes, 1 pteridine-associated gene, 37 melanin-associated genes, and 12 heme-associated genes. These pigment-associated genes were related to the formation of the red head and black thorax of G. aureata. A key gene, yellow-h, in the melanin pathway was significantly upregulated in the thorax, suggesting that it is related to the formation of the black body and contributed to the adaptation of G. aureata to low temperatures and high ultraviolet radiation in the QTP. Another key gene, cardinal, in the ommochrome pathway was significantly upregulated in the head and may be related to red warning color formation. We also identified 107 olfactory-related genes in G. aureata, including genes encoding 29 odorant-binding proteins, 16 chemosensory proteins, 22 odorant receptor proteins, 14 ionotropic receptors, 12 gustatory receptors, 12 odorant degrading enzymes, and 2 sensory neuron membrane proteins. Diversification of olfactory-related genes may be associated with the feeding habits of G. aureata, including larvae dispersal and searching for plant resources available in the QTP. These results provide new insights into high-altitude adaptation of Gynaephora in the QTP and may contribute to the development of new control strategies for these pests.

Dissection of a Down syndrome-associated trisomy to separate the gene dosage-dependent and -independent effects of an extra chromosome.

As an aneuploidy, trisomy is associated with mammalian embryonic and postnatal abnormalities. Understanding the underlying mechanisms involved in mutant phenotypes is broadly important and may lead to new strategies to treat clinical manifestations in individuals with trisomies, such as trisomy 21 [Down syndrome (DS)]. Although increased gene dosage effects because of a trisomy may account for the mutant phenotypes, there is also the possibility that phenotypic consequences of a trisomy can arise because of the presence of a freely segregating extra chromosome with its own centromere, i.e. a 'free trisomy' independent of gene dosage effects. Presently, there are no reports of attempts to functionally separate these two types of effects in mammals. To fill this gap, here we describe a strategy that employed two new mouse models of DS, Ts65Dn;Df(17)2Yey/+ and Dp(16)1Yey/Df(16)8Yey. Both models carry triplications of the same 103 human chromosome 21 gene orthologs; however, only Ts65Dn;Df(17)2Yey/+ mice carry a free trisomy. Comparison of these models revealed the gene dosage-independent impacts of an extra chromosome at the phenotypic and molecular levels for the first time. They are reflected by impairments of Ts65Dn;Df(17)2Yey/+ males in T-maze tests when compared with Dp(16)1Yey/Df(16)8Yey males. Results from the transcriptomic analysis suggest the extra chromosome plays a major role in trisomy-associated expression alterations of disomic genes beyond gene dosage effects. This model system can now be used to deepen our mechanistic understanding of this common human aneuploidy and obtain new insights into the effects of free trisomies in other human diseases such as cancers.

[Tiaoshen Jieyu acupuncture combined with sertraline hydrochloride tablet for post-stoke depression: a randomized controlled trial].

OBJECTIVE: To compare the clinical efficacy between Tiaoshen Jieyu acupuncture (acupuncture for regulating mind and relieving depression) combined with sertraline hydrochloride tablet and simple sertraline hydrochloride tablet for post-stroke depression (PSD). METHODS: A total of 76 patients with PSD were randomized into an observation group (38 cases, 6 cases dropped off) and a control group (38 cases, 4 cases dropped off). Both groups were treated with conventional treatment i.e. controlling blood pressure and anti-inflammation. Sertraline hydrochloride tablet was given orally in the control group, 20 mg a time, once a day. On the basis of the treatment in the control group, Tiaoshen Jieyu acupuncture was applied at Baihui (GV 20), Yintang (GV 24+), Neiguan (PC 6), Taichong (LR 3), etc. in the observation group, Baihui (GV 20) and Yintang (GV 24+) were connected to electroacupuncture, with disperse-dense wave, 2 Hz/100 Hz in frequency, 30 min a time, once a day, 6 times a week. Treatment of 8 weeks was required in both groups. Before and after treatment, the scores of Hamilton depression scale (HAMD), National Institutes of Health stroke scale (NIHSS), Barthel index (BI) and Pittsburgh sleep quality index (PSQI) were observed respectively, the therapeutic efficacy and rate of adverse reactions were evaluated in the two groups. RESULTS: After treatment, the scores of HAMD, NIHSS and PSQI were lower while BI scores were higher than those before treatment in both groups (P<0.05); the scores of HAMD, NIHSS and PSQI in the observation group were lower while BI score was higher than those in the control group (P<0.05). The total effective rate was 93.8% (30/32) in the observation group, which was higher than 70.6% (24/34) in the control group (P<0.05). The rate of adverse reactions was 9.4% (3/32) in the observation group, which was lower than 32.4% (11/34) in the control group (P<0.05). CONCLUSION: Tiaoshen Jieyu acupuncture combined with sertraline hydrochloride tablet can improve the depression degree, neurological function, activity of daily living and sleep quality in patients with post-stroke depression, the clinical efficacy is superior to simple sertraline hydrochloride, and can alleviate the adverse reactions caused by medication.

Hearing impairment in murine model of Down syndrome.

Hearing impairment is a cardinal feature of Down syndrome (DS), but its clinical manifestations have been attributed to multiple factors. Murine models could provide mechanistic insights on various causes of hearing loss in DS. To investigate mechanisms of hearing loss in DS in the absence of the cadherin 23 mutation, we backcrossed our DS mice, Dp(16)1Yey, onto normal-hearing CBA/J mice and evaluated their auditory function. Body weights of wild type (WT) and DS mice were similar at 3-months of age, but at 9-months, WT weighed 30% more than DS mice. Distortion product otoacoustic emissions (DPOAE), a test of sensory outer hair cell (OHC) function negatively impacted by conductive hearing loss, were reduced in amplitude and sensitivity across all frequencies in DS mice. The middle ear space in DS mice appeared normal with no evidence of infection. MicroCT structural imaging of DS temporal bones revealed a smaller tympanic membrane diameter, oval window, and middle ear space and localized thickening of the bony otic capsule, but no gross abnormalities of the middle ear ossicles. Histological analysis of the cochlear and vestibular sensory epithelium revealed a normal density of cochlear and vestibular hair cells; however, the cochlear basal membrane was approximately 0.6 mm shorter in DS than WT mice so that the total number of hair cells was greater in WT than DS mice. In DS mice, the early and late peaks in the auditory brainstem response (ABR), reflecting neural responses from the cochlear auditory nerve followed by subsequent neural centers in the brainstem, were reduced in amplitude and ABR thresholds were elevated to a similar degree across all frequencies, consistent with a conductive hearing impairment. The latency of the peaks in the ABR waveform were longer in DS than WT mice when compared at the same intensity; however, the latency delays disappeared when the data were compared at the same intensity above thresholds to compensate for the conductive hearing loss. Future studies using wideband tympanometry and absorbance together with detailed histological analysis of the middle ear could illuminate the nature of the conductive hearing impairment in DS mice.

Tuning the Oxidation State of Cu Electrodes for Selective Electrosynthesis of Ammonia from Nitrate.

Electrochemical reduction of nitrate (NO3-) to ammonia (NH3) provides a promising route for recycling nitrate from wastewater to balance the nitrogen cycle and sustainable production of ammonia. Among various catalytic materials for NO3- electroreduction, Cu shows a favorable selectivity to NH3. However, Cu can be easily oxidized, while the effect of the Cu oxidation state on NO3- reduction remains to be elucidated. Here, we report that oxidic Cu formed on a Cu electrode can enhance its activity and selectivity for NO3- reduction to NH3. We first used a polished Cu foil as a model catalyst for NO3- reduction and found that a brief exposure of the Cu electrode to air could increase its yield rate and Faradaic efficiency for NH3 production. The improved catalytic performance was attributed to the formed Cu+ sites that can reduce the energy barrier for NO3- reduction to NH3 and suppress the competing HER reaction. Based on this finding, an oxide-derived Cu (OD-Cu) electrode was prepared by annealing a Cu foil in O2 gas followed by electroreduction, which exhibited superior performance for NO3- reduction to NH3, with a Faradaic efficiency of 92% and a yield rate of 1.1 mmol h-1 cm-2 for NH3 production at -0.15 V versus reversible hydrogen electrode. Moreover, an OD-Cu foam electrode was similarly developed to demonstrate NO3- recycling from a low-concentration NO3- solution, which showed a nearly 100% conversion of NO3- to NH3 using a circulating flow cell.

Coat Color-Facilitated Efficient Generation and Analysis of a Mouse Model of Down Syndrome Triplicated for All Human Chromosome 21 Orthologous Regions.

Down syndrome (DS) is one of the most complex genetic disorders in humans and a leading genetic cause of developmental delays and intellectual disabilities. The mouse remains an essential model organism in DS research because human chromosome 21 (Hsa21) is orthologously conserved with three regions in the mouse genome. Recent studies have revealed complex interactions among different triplicated genomic regions and Hsa21 gene orthologs that underlie major DS phenotypes. Because we do not know conclusively which triplicated genes are indispensable in such interactions for a specific phenotype, it is desirable that all evolutionarily conserved Hsa21 gene orthologs are triplicated in a complete model. For this reason, the Dp(10)1Yey/+;Dp(16)1Yey/+;Dp(17)1Yey/+ mouse is the most complete model of DS to reflect gene dosage effects because it is the only mutant triplicated for all Hsa21 orthologous regions. Recently, several groups have expressed concerns that efforts needed to generate the triple compound model would be so overwhelming that it may be impractical to take advantage of its unique strength. To alleviate these concerns, we developed a strategy to drastically improve the efficiency of generating the triple compound model with the aid of a targeted coat color, and the results confirmed that the mutant mice generated via this approach exhibited cognitive deficits.

Mechanistic Analysis of Age-Related Clinical Manifestations in Down Syndrome.

Down syndrome (DS) is the most common genetic cause of Alzheimer's disease (AD) due to trisomy for all or part of human chromosome 21 (Hsa21). It is also associated with other phenotypes including distinctive facial features, cardiac defects, growth delay, intellectual disability, immune system abnormalities, and hearing loss. All adults with DS demonstrate AD-like brain pathology, including amyloid plaques and neurofibrillary tangles, by age 40 and dementia typically by age 60. There is compelling evidence that increased APP gene dose is necessary for AD in DS, and the mechanism for this effect has begun to emerge, implicating the C-terminal APP fragment of 99 amino acid (ß-CTF). The products of other triplicated genes on Hsa21 might act to modify the impact of APP triplication by altering the overall rate of biological aging. Another important age-related DS phenotype is hearing loss, and while its mechanism is unknown, we describe its characteristics here. Moreover, immune system abnormalities in DS, involving interferon pathway genes and aging, predispose to diverse infections and might modify the severity of COVID-19. All these considerations suggest human trisomy 21 impacts several diseases in an age-dependent manner. Thus, understanding the possible aging-related mechanisms associated with these clinical manifestations of DS will facilitate therapeutic interventions in mid-to-late adulthood, while at the same time shedding light on basic mechanisms of aging.

Enhancing carbon dioxide gas-diffusion electrolysis by creating a hydrophobic catalyst microenvironment.

Electroreduction of carbon dioxide (CO2) over copper-based catalysts provides an attractive approach for sustainable fuel production. While efforts are focused on developing catalytic materials, it is also critical to understand and control the microenvironment around catalytic sites, which can mediate the transport of reaction species and influence reaction pathways. Here, we show that a hydrophobic microenvironment can significantly enhance CO2 gas-diffusion electrolysis. For proof-of-concept, we use commercial copper nanoparticles and disperse hydrophobic polytetrafluoroethylene (PTFE) nanoparticles inside the catalyst layer. Consequently, the PTFE-added electrode achieves a greatly improved activity and Faradaic efficiency for CO2 reduction, with a partial current density >250 mA cm-2 and a single-pass conversion of 14% at moderate potentials, which are around twice that of a regular electrode without added PTFE. The improvement is attributed to a balanced gas/liquid microenvironment that reduces the diffusion layer thickness, accelerates CO2 mass transport, and increases CO2 local concentration for the electrolysis.

Fufang Xueshuantong alleviates diabetic retinopathy by activating the PPAR signalling pathway and complement and coagulation cascades.

ETHNOPHARMACOLOGICAL RELEVANCE: Fufang Xueshuantong (FXST) is a traditional Chinese patent medicine composed of Panax notoginseng (Burkill) F.H.Chen (Araliaceae), Salvia miltiorrhiza Bunge (Lamiaceae), Astragalus propinquus Schischkin (Leguminosae), and Scrophularia ningpoensis Hemsl. (Scrophulariaceae). It has been widely used for the treatment of diabetic retinopathy (DR) and exerts a positive clinical therapeutic effect. AIM OF THE STUDY: The aim of this study was to observe the effect of FXST on diabetic rat retinas and investigate its pharmacological mechanism for improving DR. METHODS: The diabetic rat model was established by intraperitoneal injection of streptozotocin. The rats were divided into a normal group, diabetic group, and FXST group. The rats in the FXST group were treated with FXST by intragastric administration for 12 weeks while other rats were given the same volume of normal saline. The haemodynamic parameters of the central retinal artery in the rats were measured by ultrasound. Haematoxylin-eosin staining was utilised to observe the pathological structural changes in the retina. The apoptosis of retinal nerve cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labelling. RNA sequencing was used to screen the differentially expressed genes (DEGs), and enrichment analyses were performed. The DEGs were validated through real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). RESULTS: The peak systolic velocity, end diastolic velocity, and mean velocity decreased while the resistance index and pulsatility index increased in the diabetic rat retinas. FXST also improved haemodynamics. In contrast with the diabetic group, FXST allayed the disorder and oedema of the retinal structure in addition to reversing the reductions in retinal thickness and retinal ganglion cell number. It also decreased the apoptosis index of retinal cells. A total of 1134 DEGs were identified by RNA sequencing in the FXST group compared to the diabetic group, including 814 upregulated genes and 320 downregulated genes. These genes were enriched in the complement and coagulation cascades as well as the peroxisome proliferator-activated receptor (PPAR) signalling pathway. Several DEGs, including PPAR gamma, perilipin 4, acyl-CoA dehydrogenase long chain, CD55 molecule, and plasminogen activator urokinase, were identified by qRT-PCR, and the results were consistent with the RNA sequencing data. CONCLUSIONS: FXST alleviates DR by improving the haemodynamics and morphological alterations of diabetic rat retinas, which are mediated by complement and coagulation cascades and the PPAR signalling pathway.

HuoXue JieDu formula improves diabetic retinopathy in rats by regulating microRNAs.

ETHNOPHARMACOLOGICAL RELEVANCE: HuoXue JieDu Formula (HXJDF) originates from classical formulas and was formed based on clinical experience. It is composed of Euonymus alatus (Thunb.) Siebold, Panax notoginseng (Burkill) F.H. Chen, the roots of Anguina kirilowii (Maxim.) Kuntze, and Coptis omeiensis (C. Chen) C.Y.Cheng. HXJDF prevents the deterioration of diabetic retinopathy. AIM OF THE STUDY: To evaluate the effects of HXJDF on diabetic retinopathy in rats and investigate the roles of miRNAs in the effects of HXJDF. MATERIALS AND METHODS: A single intraperitoneal injection of streptozotocin (STZ) (65 mg/kg) was used to induce diabetes in rats. Rats were divided into three groups: normal, diabetic, and diabetic + HXJDF. Rats were treated with HXJDF (15.4 g/kg) or water by oral gavage for twelve weeks. At the end of the treatment, rats were anaesthetized, and retinal haemodynamic changes were measured. Then, the retinas were removed and examined by haematoxylin and eosin (HE) staining and TUNEL assays. In addition, miRNA expression profiling was performed using miRNA microarrays and further validated by quantitative real-time PCR (qRT-PCR). RESULTS: Diabetes reduced peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV) and central retinal vein velocity (CRV) but increased the resistance index (RI) and pulsatility index (PI). In addition, in the diabetic group, retinal cell arrangement was disordered and loosely arranged, the retinal thickness and retinal ganglion cell (RGC) number decreased, and retinal cell apoptosis increased. In addition, 11 miRNAs were upregulated and 4 miRNAs were downregulated. After treatment, HXJDF improved retinal haemodynamics and morphologic changes, restored retinal thickness and RGC number and decreased retinal cell apoptosis. Furthermore, the changes in miRNA expression were significantly abolished by HXJDF. CONCLUSION: HXJDF may prevent DR by regulating the expression of miRNAs.

A subsequent procedure for further deciphering weapons after application of the Trace Metal Detection Test (TMDT): Proof of concept.

The trace metal detection test (TMDT) is an effective and convenient technique to potentially link perpetrators and metallic weapons by comparing morphological information of developed imprints and suspected weapons. However, metallic items without characteristic patterns and incomplete contact with weapons often lead to inadequate morphological features in developed imprints on hands, resulting in difficulty in identifying suspected weapons and a failure to demonstrate potential relationships between perpetrators and weapons. This paper presents a subsequent procedure, after application of the TMDT, for inferring possible weapon-source of a specific imprint. As a proof of concept, all the experiments involved metallic items as an example and were carried out under controlled laboratory conditions. An analytical method was established by selecting elements of interest in developed imprints from seven metallic items (three groups), undertaking quantitative ICP-MS determination of the elements, and comparing the elements in these imprints (inter- and intra-group comparisons) and with those in their source items. Using the established method, possible groups and types of source metallic items could be inferred based on elemental characteristics in imprints, under the premise that no other metal sources exist before or after contacting specified metallic items. This method could be useful for providing investigative clues and evidence of association for developed imprints that lack unique morphological features and for verifying the results of color reactions in the TMDT. For this reason, it can serve as a standard supplementary procedure after the application of the TMDT, which could further strengthen the correlations between perpetrators and weapons even common metallic objects.

Genetic and epigenetic pathways in Down syndrome: Insights to the brain and immune system from humans and mouse models.

The presence of an extra copy of human chromosome 21 (Hsa21) leads to a constellation of phenotypic manifestations in Down syndrome (DS), including prominent effects on the brain and immune system. Intensive efforts to unravel the molecular mechanisms underlying these phenotypes may help developing effective therapies, both in DS and in the general population. Here we review recent progress in genetic and epigenetic analysis of trisomy 21 (Ts21). New mouse models of DS based on syntenic conservation of segments of the mouse and human chromosomes are starting to clarify the contributions of chromosomal subregions and orthologous genes to specific phenotypes in DS. The expression of genes on Hsa21 is regulated by epigenetic mechanisms, and with recent findings of highly recurrent gene-specific changes in DNA methylation patterns in brain and immune system cells with Ts21, the epigenomics of DS has become an active research area. Here we highlight the value of combining human studies with mouse models for defining DS critical genes and understanding the trans-acting effects of a simple chromosomal aneuploidy on genome-wide epigenetic patterning. These genetic and epigenetic studies are starting to uncover fundamental biological mechanisms, leading to insights that may soon become therapeutically relevant.

A modified trace metal detection test for secondary imprints on porous substrates: A preliminary study.

In the investigation of criminal cases involving metallic weapons such as firearms and knives, the trace metal detection test (TMDT) and the transfer detection technique are two effective and on-the-spot methods to link a suspect and a suspected metallic weapon. In general, these tests need to be conducted on suspects' hands or done by lifting trace metals from their hands within 3 days of the crime being committed. However, if no suspects are arrested within this period, neither of these two techniques is applicable. This paper presents preliminary development of a modified TMDT to overcome the intrinsic disadvantages of conventional TMDTs. The method primarily focuses on the secondary imprints on porous substrates that are transferred unconsciously from the palms of criminals after handling galvanized weapons. The modified TMDT was established by studying the effect of various factors on secondary imprints on porous substrates. We also tested the effectiveness of the modified TMDT for common porous substrates and galvanized weapons and its relative sensitivity in a depletion series. Additionally, the storage conditions of the developed secondary imprints as physical evidence were studied under different time lapses and light conditions. Finally, we proposed an improved procedure for detecting metal traces formed in the use of metallic weapons and subsequent activities at a crime scene. The modified TMDT provides a novel method for investigators to demonstrate the relationship between a suspect and a metallic weapon, thus reducing the heavy reliance of conventional TMDTs on suspects and the time limit available to visualize or lift metal traces. For this reason, it can be used as a complementary and remedial method for conventional TMDTs, especially when suspects are not arrested within 3 days of the commission of a crime. Furthermore, the improved procedure can serve as a guide for investigators to apply the TMDT series properly to solving the cases involving metallic weapons.

Adaptive evidence of mitochondrial genomes in Dolycoris baccarum (Hemiptera: Pentatomidae) to divergent altitude environments.

Given mitochondrion is the 'energy and oxygen usage factories', adaptive signatures of mitochondrial genes have been extensively investigated in vertebrates from different altitudes, but few studies focus on insects. Here, we sequenced the complete mitochondrial genome (mitogenome) of Dolycoris. baccarum living in the Tibetan Plateau (DBHC, ∼3200 m above sea level (asl)) and conducted a detailed comparative analysis with another D. baccarum mitogenome (DBQY) from relatively low altitude (∼1300 m asl). All the 37 mitochondrial genes were highly conserved and under purifying selection, except for two mitochondrial protein-coding genes (MPCGs) (atp6 and nad5) that showed positively selected signatures. We therefore further examined non-synonymous substitutions in atp6 and nad5, by sequencing more individuals from three populations with different altitudes. We found that these non-synonymous substitutions were polymorphic in these populations, likely due to relaxed selection constraints in different altitudes. Purifying selection in all mitochondrial genes may be due to their functional importance for the precision of ATP production usually. Length difference in mitochondrial control regions between DBHC and DBQY was also conversed at the population level, indicating that sequence size adjustments in control region may be associated with adaptation to divergent altitudes. Quantitatively real-time PCR analysis for 12 MPCGs showed that gene expression patterns had a significant change between the two populations, suggesting that expression levels of MPCGs could be modulated by divergent environmental pressures (e.g. oxygen content and ambient temperature). These results provided an important guide for further uncovering genetic mechanisms of ecological adaptation in insects.