Isolation And Characterisation Of Immunoglobulin Gene Superfamily Molecules From Lower Vertebrates (Fish)

Acquired immunity in vertebrates is a major mechanism of the immune system, which enables the vertebrates to discriminate self and non-self The most important feature of acquired immunity is the major histocompatibility complex (MHC) restricted-cellular immune response. This involves several important elements including MHC molecules and T cell antigen receptor (TCR) complex. MHC molecules are glycoproteins that recognise and present self and foreign peptides to T-cells via the TCR, causing the T cell to proliferate and secrete cytokines. There is increasing evidence that peripheral T cells and MHC restricted cellular immune responses occur in all vertebrates. However, the exact nature of the TCR and MHC in lower vertebrates has still to be established. The aim of this thesis was firstly, to use the polymerase chain reaction (PCR) in conjunction with degenerative primers to the TCR β chain variable region (TCRBV) sequences of the homed shark to allow the amplification of the TCR-like genes from dogfish, Scyliorhinus canicula; secondly, to employ a similar strategy using degenerative primers to the banded houndshark MHC class-I α3 DNA sequence, to amplify MHC genes from S. canicula. Using the degenerative primers, four clones from dogfish genomic DNA were obtained. These clones showed homology to TCR genes of other species. The amino acid sequence of clone 2C144 showed homology to the TCRBV region of several species. The highest similarities include 51.7% with the honed shark TCRBV, 45.1% with human TCRBV, 41% with monkey TCRBV, 40.7% with bovine TCRBV and 38.8 and 37.5% with chimpanzee and rat TCRBV, respectively. The clone 6C43 also showed homology to the TCRBV genes of several species (similarity is between 21.1% to 23.9%). Another two clones (6C53 and 6C54) were identified that showed high homology to the TCR δ chain variable region (TCRDV) of other vertebrates with 45.7% identity to the honed shark TCRDV region, 43.2% identity to mouse TCRDV, 32.2% identity to porcine TCRDV region, and 30.7% identity to human TCRDV. The highly conserved residues in the other vertebrates TCR are present in these four clones as well, such as WYRQ37 and YY(F)C92 motifs. Southern blotting analysis with the putative TCRBV (2Cl44) and TCRDV (6C53 and 6C54) suggested that polymorphism existed between different fish. Northern blotting analysis with the probe 6C53 identified a transcript of approximately 2 kb in the spleen., lymphocytes and brain as well, with the probe 2C144 identified a transcript of approximately 2 kb in the lymphocytes of dogfish. The sequences of nine clones obtained using cDNA as a template from dogfish together with degenerative primers showed high homology to the membrane-proximal domain of the MHC class II α chain in several species. These clones exhibited a high degree of homology to the nurse shark MHC class II α chain (74.1%), zebrafish MHC class II α chain (52.8%), mouse MHC class II I-A (49.6%), rat MHC class II α chain (49.9%), bovine MHC class II DYα chain and DQα chain (52.7% and 44.9%, respectively), human HLA- DP, - DQα and -DRα chain (44.4%) respectively. The cysteine residues of the membrane-proximal domain are conserved in the dogfish, suggesting that it may have a similar tertiary structure to mammalian MHC class II proteins. A highly conserved tryptophan residue at position 121 was found in the dogfish and an N-linked glycosylation site was present at position 133, whilst in higher mammals it is usually found at position 118. The Southern blotting analysis using probe DM9 showed that there may be more than four loci of MHC class IIA in dogfish. These results suggest that the MHC class II, TCRB and TCRD genes are present in dogfish. The dogfish may have distinct T-cells, expressing either αlβ or γ/δ heterodimers. Conserved key residues in both MHC class IIA. TCRB and TCRD suggest that these genes may encode functional MHC class II, TCRB and TCRD molecules. The MHC restricted cellular immune response may be present in dogfish. Dogfish TCRB, TCRD and MHC class II genes show high homology with several species including human, rat, bovine and other fish species, which implies that the immunoglobulin (Ig) superfamily has evolved from a common ancestor

Attention-Block Deep Learning Based Features Fusion in Wearable Social Sensor for Mental Wellbeing Evaluations

With the progressive increase of stress, anxiety and depression in working and living environment, mental health assessment becomes an important social interaction research topic. Generally, clinicians evaluate the psychology of participants through an effective psychological evaluation and questionnaires. However, these methods suffer from subjectivity and memory effects. In this paper, a new multi- sensing wearable device has been developed and applied in self-designed psychological tests. Speech under different emotions as well as behavior signals are captured and analyzed. The mental state of the participants is objectively assessed through a group of psychological questionnaires. In particular, we propose an attention-based block deep learning architecture within the device for multi-feature classification and fusion analysis. This enables the deep learning architecture to autonomously train to obtain the optimum fusion weights of different domain features. The proposed attention-based architecture has led to improving performance compared with direct connecting fusion method. Experimental studies have been carried out in order to verify the effectiveness and robustness of the proposed architecture. The obtained results have shown that the wearable multi-sensing devices equipped with the attention-based block deep learning architecture can effectively classify mental state with better performance

Reinforcing endothelial junctions prevents microvessel permeability increase and tumor cell adhesion in microvessels in vivo

Tumor cell adhesion to the microvessel wall is a critical step during tumor metastasis. Vascular endothelial growth factor (VEGF), a secretion of tumor cells, can increase microvessel permeability and tumor cell adhesion in the microvessel. To test the hypothesis that inhibiting permeability increase can reduce tumor cell adhesion, we used in vivo fluorescence microscopy to measure both microvessel permeability and adhesion rates of human mammary carcinoma MDA-MB-231 cells in post-capillary venules of rat mesentery under the treatment of VEGF and a cAMP analog, 8-bromo-cAMP, which can decrease microvessel permeability. By immunostaining adherens junction proteins between endothelial cells forming the microvessel wall, we further investigated the structural mechanism by which cAMP abolishes VEGF-induced increase in microvessel permeability and tumor cell adhesion. Our results demonstrate that 1) Pretreatment of microvessels with cAMP can abolish VEGF-enhanced microvessel permeability and tumor cell adhesion; 2) Tumor cells prefer to adhere to the endothelial cell junctions instead of cell bodies; 3) VEGF increases microvessel permeability and tumor cell adhesion by compromising endothelial junctions while cAMP abolishes these effects of VEGF by reinforcing the junctions. These results suggest that strengthening the microvessel wall integrity can be a potential approach to inhibiting hematogenous tumor metastasis

The Rate of Decline of Glomerular Filtration Rate May Not Be Associated with Polymorphism of the PPAR γ

The aim of the study was to investigate whether a Pro12Ala polymorphism in the peroxisome proliferator-activated receptor gamma 2 (PPARγ2) gene is associated with the progress of diabetic nephropathy in patients with type 1 diabetes. 197 Caucasian patients with type 1 diabetes and ethnically matched 151 normal healthy controls were genotyped for this polymorphism. Results showed that there were no significant differences in the frequencies of the genotypes and alleles of the polymorphism between groups. Multiple regression analysis in 77 patients demonstrated that the rate of decline in renal function in terms of glomerular filtration rate was significantly correlated to the baseline level of cholesterol (P=0.0014), mean diastolic blood pressure during follow-up period (P=0.019), and baseline level of HbA1c (P=0.022) adjusting for the effect of diabetes duration and gender, but no significant association was found between the polymorphism and the progression of diabetic nephropathy in our studied population. In summary, our results show that the PPARγ2 polymorphism is unlikely to be associated with the development and progression of the diabetic nephropathy in patients with type 1 diabetes. Further studies in different populations may be warranted to confirm our findings as the sample size in our study was relatively small

Endothelial Surface Glycocalyx Can Regulate Flow-Induced Nitric Oxide Production in Microvessels In Vivo

Due to its unique location, the endothelial surface glycocalyx (ESG) at the luminal side of the microvessel wall may serve as a mechano-sensor and transducer of blood flow and thus regulate endothelial functions. To examine this role of the ESG, we used fluorescence microscopy to measure nitric oxide (NO) production in post-capillary venules and arterioles of rat mesentery under reduced (low) and normal (high) flow conditions, with and without enzyme pretreatment to remove heparan sulfate (HS) of the ESG and in the presence of an endothelial nitric oxide synthase (eNOS) inhibitor, NG-monomethyl-L-arginine (L-NMMA). Rats (SD, 250–300g) were anesthetized. The mesentery was gently taken out from the abdominal cavity and arranged on the surface of a glass coverslip for the measurement. An individual post-capillary venule or arteriole was cannulated and loaded for 45 min with 5 μM 4, 5-Diaminofluorescein diacetate, a membrane permeable fluorescent indictor for NO, then the NO production was measured for ~10 min under a low flow (~300 μm/s) and for ~60 min under a high flow (~1000 μm/s). In the 15 min after switching to the high flow, DAF-2-NO fluorescence intensity increased to 1.27-fold of its baseline, DAF-2-NO continuously increased under the high flow, to 1.53-fold of its baseline in 60 min. Inhibition of eNOS by 1 mM L-NMMA attenuated the flow-induced NO production to 1.13-fold in 15 min and 1.30-fold of its baseline in 60 min, respectively. In contrast, no significant increase in NO production was observed after switching to the high flow for 60 min when 1 h pretreatment with 50 mU/mL heparanase III to degrade the ESG was applied. Similar NO production was observed in arterioles under low and high flows and under eNOS inhibition. Our results suggest that ESG participates in endothelial cell mechanosensing and transduction through its heparan sulfate to activate eNOS

Effects of divalent cations on cell adhesion between human neutrophil and endothelial ligand VCAM-1: a lattice Boltzmann analysis

AbstractIt was reported that the circulating blood cells, including neutrophils, were more likely adherent to the curved micro-vessels than the straight ones. Our previous work indicated that the vessel curvature, cell-cell interaction, and wall shear stress variation would greatly affect this preferential adhesion. It was also found that the affinity state of integrins would be influenced by different divalent cations, which provides an opportunity to explore the particular importance of integrins activation in neutrophils adhesion. In this study, we aim at numerically investigating the effects of divalent cations, i.e. Mn2+, Mg2+ plus EGTA, and Ca2+, on VLA-4/VCAM-1 adhesion under flow condition. The blood dynamics was carried out by the lattice Boltzmann method (LBM), the neutrophil dynamics was governed by the Newton's law of translation and rotation, and a refined neutrophil adhesive dynamics model that taken into account the effect of wall shear stress gradient on receptor-ligand bonds was applied to solve the VLA-4/VCAM-1 adhesion. The simulation results indicated that the divalent cations significantly influenced neutrophils adhesion under hydrodynamic condition. It was found that the capability of stimulating affinity state of VLA-4 to VCAM-1 was larger in Mg2+ plus EGTA than in Ca2+, and largest in the presence of Mn2+. Our results would be helpful to understand the β1-integrin-mediated neutrophils adhesion in real physiological situations

Car-following model considering the lane-changing prevention effect and its stability analysis

The car-following behavior has attracted much attention in past decades. However, the majority of the existing studies ignored the fact that the following vehicle in car-following may prevent the lane-changing of the vehicle on the adjacent lanes, when a large gap exists between the following and leading vehicles. Therefore, this paper proposes a new car-following model considering the lane-changing prevention effect. The final velocity of the following vehicle is a combination of a safe velocity and a lane-changing prevention velocity. The stability condition of the model is derived and verified through numerical simulation, and impacts of several factors on stability are analyzed. The results display that the stability condition is consistent with the simulation results. The most significant factors impacting on the stability are the safe time-headway for lane-changing and the contribution proportion α of the safe velocity and lane-changing prevention velocity. The optimal values exist for the proportion α and lane-changing time headway that can make the stability of the traffic flow the highest

Analysis of early warning indicators of death in patients with severe fever with thrombocytopenia syndrome

Abstract Background Since its discovery, severe fever with thrombocytopenia syndrome (SFTS) has been characterized by rapid progression and poor prognosis, and no specific treatment is available. The aim of this study was to investigate the early warning indicators of mortality in SFTS patients. Methods This is a retrospective cross-sectional study. The study subjects were patients who were admitted to the hospital with a confirmed diagnosis of SFTS from January 2023 to October 2023, and their clinical symptoms and signs at the time of admission, as well as the laboratory indexes of the first blood collection after admission were collected, grouped according to the prognosis, and statistically analyzed. Results A total of 141 patients were collected, of which 27 patients died and 114 patients were in the survival group. Through statistical analysis, patients with combined hemorrhagic manifestations, disturbance of consciousness, lymphopenia, elevated lipase, and prolonged thrombin time on admission were independent risk factors for patients’ death. By plotting the working characteristic curve of the subjects, as well as calculating the area under the curve, the results showed that the AUC of lymphopenia count was 0.670, 95% CI (0.563–0.776), P = 0.006; the AUC of elevated serum lipase index was 0.789, 95% CI (0.699–0.878), p < 0.001; the AUC of prolonged thrombin time was 0.749, 95% CI (0.645–0.854), p < 0.001. Conclusion Patients with hemorrhagic manifestations, disturbance of consciousness, lymphocyte reduction, elevated serum lipase, and prolonged thrombin time on admission are more worthy of the clinician’s attention, and require early and effective interventions to avoid further disease progression

Modeling the Traffic Flow of the Urban Signalized Intersection with a Straddling Work Zone

Work zones widely exist on urban roads in many countries and have a significant negative impact on traffic. Few studies have focused on modeling the traffic flow of the work zone on the urban arterials, especially on the work zone at the intersections. In this paper, a microscopic model based on the social force theory for the traffic flow of the intersection with a specific work zone, called straddling work zone, is proposed. The model can capture the no lane division and irregular boundary characteristics of the traffic of the intersection with a straddling work zone and also can reflect the interaction of the intersection traffic flows from the two opposite directions. The proposed model is calibrated and validated using the real work zone data, and the results display that the MARE values are all less than 10%. The factors affecting the traffic flow in the straddling work zone are analyzed through simulation. Our study reveals that the distance from the lower edge of the work zone to the median divider of the road and the proportion of large vehicles in the work zone have the greatest impact on the signalized intersection, which provides a reference for the future traffic control at the intersection with the straddling work zone