RGD-hirudin-based low molecular weight peptide prevents blood coagulation via subcutaneous injection.

Thromboembolic disease is a common cardio-cerebral vascular disease that threatens human life and health. Thrombin not only affects the exogenous coagulation pathway, but also the endogenous pathway. Thus, it becomes one of the most important targets of anticoagulant drugs. RGD-hirudin is an anticoagulant drug targeting thrombin, but it can only be administered intravenously. We designed a low molecular weight peptide based on RGD-hirudin that could prevent blood clots. We first used NMR to identify the key amino acid residues of RGD-hirudin that interacted with thrombin. Then, we designed a novel direct thrombin inhibitor peptide (DTIP) based on the structure and function of RGD-hirudin using homology modeling. Molecular docking showed that the targeting and binding of DTIP with thrombin were similar to those of RGD-hirudin, suggesting DTIP interacted directly with thrombin. The active amino acids of DTIP were identified by alanine scanning, and mutants were successfully constructed. In blood clotting time tests in vitro, we found that aPTT, PT, and TT in the rat plasma added with DTIP were greatly prolonged than in that added with the mutants. Subcutaneous injection of DTIP in rats also could significantly prolong the clotting time. Thrombelastography analysis revealed that DTIP significantly delayed blood coagulation. Bio-layer interferometry study showed that there were no significant differences between DTIP and the mutants in thrombin affinity constants, suggesting that it might bind to other sites of thrombin rather than to its active center. Our results demonstrate that DTIP with low molecular weight can prevent thrombosis via subcutaneous injection.

Characterization of 18F-PM-PBB3 (18F-APN-1607) Uptake in the rTg4510 Mouse Model of Tauopathy.

Misfolding, aggregation, and cerebral accumulation of tau deposits are hallmark features of Alzheimer's disease. Positron emission tomography study of tau can facilitate the development of anti-tau treatment. Here, we investigated a novel tau tracer 18F-PM-PBB3 (18F-APN-1607) in a mouse model of tauopathy. Dynamic PET scans were collected in groups of rTg4510 transgenic mice at 2-11 months of age. Associations between distribution volume ratios (DVR) and standardized uptake value ratios (SUVR) with cerebellum reference were used to determine the optimal scanning time and uptake pattern for each age. Immunohistochemistry staining of neurofibrillary tangles and autoradiography study was performed for ex vivo validation. An SUVR 40-70 min was most consistently correlated with DVR and was used in further analyses. Significant increased 18F-PM-PBB3 uptake in the brain cortex was found in six-month-old mice (+28.9%, p < 0.05), and increased further in the nine-month-old group (+38.8%, p < 0.01). The trend of increased SUVR value remained evident in the hippocampus and striatum regions except for cortex where uptake becomes slightly reduced in 11-month-old animals (+37.3%, p < 0.05). Radioactivity distributions from autoradiography correlate well to the presence of human tau (HT7 antibody) and hyperphosphorylated tau (antibody AT8) from the immunohistochemistry study of the adjacent brain sections. These findings supported that the 40-70 min 18F-PM-PBB3 PET scan with SUVR measurement can detect significantly increased tau deposits in a living rTg4510 transgenic mouse models as early as six-months-old. The result exhibited promising dynamic imaging capability of this novel tau tracer, and the above image characteristics should be considered in the design of longitudinal preclinical tau image studies.

The effects of mechanical insufflation-exsufflation on lung function and complications in cardiac surgery patients: a pilot study.

BACKGROUND: Postoperative positive pressure lung expansion is associated with decreased pulmonary complications and improved clinical outcomes. The aim of the present study was to compare the differences in post-operative pulmonary complications and clinical outcomes between two groups of study subjects who underwent cardiac surgery; one included subjects who received mechanical insufflation-exsufflation (MI-E) and the other included subjects who received intermittent positive pressure breathing (IPPB) therapy. METHODS: This retrospective study included 51 subjects, who underwent cardiac surgery in an intensive care unit of a tertiary hospital during the time period from June 2017 to February 2018. After liberation from mechanical ventilation, the subjects received lung expansion therapy by means of two types of positive pressure devices, MI-E (n = 21) or IPPB (n = 30). The pulmonary complications, lung function, and clinical outcomes were compared between the two groups. RESULTS: Subjects in both groups displayed similar baseline characteristics and underwent similar types of surgical procedures. Compared to subjects who received non-oscillatory therapy, those who received MI-E therapy had higher post-operative force vital capacity (58.4 ± 4.74% vs. 46.0 ± 3.70%, p = 0.042), forced expiratory volume in one second (62.4 ± 5.23% vs. 46.8 ± 3.83%, p = 0.017), and peak flow rate (67.1 ± 5.53 L vs. 55.7 ± 4.44 L p = 0.111). However, the incidence of chest pain was higher in the MI-E group (n = 13, 61.9%) than in the IPPB group (n = 4, 16.7%; odds ratio, 0.123, 95% confidence interval, 0.03-0.45; p = 0.002). The length of hospital and ICU stay, development of atelectasis, pneumonia, and pleural effusion were similar in both the groups. CONCLUSION: Both IPPB and MI-E therapies have similar effects on preventing post-operative complications in cardiac surgery patients. However, compared to IPPB therapy, MI-E therapy was associated with better-preserved pulmonary function and higher incidence of chest pain.

Recovery of pulmonary functions, exercise capacity, and quality of life after pulmonary rehabilitation in survivors of ARDS due to severe influenza A (H1N1) pneumonitis.

BACKGROUND: Acute respiratory distress syndrome (ARDS) due to severe influenza A H1N1 pneumonitis would result in impaired pulmonary functions and health-related quality of life (HRQoL) after hospital discharge. OBJECTIVES: The recovery of pulmonary functions, exercise capacity, and HRQoL in the survivors of ARDS due to 2009 pandemic influenza A H1N1 pneumonitis (H1N1-ARDS) was evaluated in a tertiary teaching hospital in northern Taiwan between May 2010 and June 2011. PATIENTS AND METHODS: Data of spirometry, total lung capacity (TLC), diffusing capacity of carbon monoxide (DLCO ), and 6-minute walk distance (6MWD) in the patients survived from H1N1-ARDS were collected 1, 3, and 6 months post-hospital discharge. HRQoL was evaluated with St. George respiratory questionnaire (SGRQ). RESULTS: Nine survivors of H1N1-ARDS in the study period were included. All these patients received 2 months' pulmonary rehabilitation program. Pulmonary functions and exercise capacity included TLC, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1 ), DLCO , and 6MWD improved from 1 to 3 months post-hospital discharge. Only TLC had further significant improvement from 3 to 6 months. HRQoL represented as the total score of SGRQ had no significant improvement in the first 3 months but improved significantly from 3 to 6 months post-discharge. CONCLUSION: The impaired pulmonary functions and exercise capacity in the survivors of H1N1-ARDS improved soon at 3 months after hospital discharge. Their quality of life had keeping improved at 6 months even though there was no further improvement of their pulmonary functions and exercise capacity.

Loss of CPEB3 Upregulates MEGF10 to Impair Mosaic Development of ON Starburst Amacrine Cells.

Cytoplasmic polyadenylation element binding protein 3 (CPEB3) regulates target RNA translation in neurons. Here, we examined CPEB3 distribution and function in the mouse retina. CPEB3 is expressed in retinal neurons, including those located in the inner nuclear layer (INL) and ganglion cell layer (GCL) but not in cone and rod photoreceptors in the outer nuclear layer (ONL). A previous study found CPEB3 expressed in cholinergic starburst amacrine cells (SACs). We first examined these cells and observed aberrant SAC mosaicism in CPEB3-knockout (KO) retinas. Retinal neurons showed orderly spatial arrangements. Many individual subtypes are organized non-randomly in patterns called mosaics. Despite CPEB3 being expressed in both populations of SACs, OFF SACs in the INL and ON SACs in the GCL, aberrant mosaic regularity was observed in only ON SACs of CPEB3-KO retinas. Molecular characterization revealed that translation of multiple epidermal growth factor 10 (Megf10) RNA is suppressed by CPEB3 during the first week of postnatal development, when MEGF10 is primarily expressed in SACs and mediates homotypic repulsive interactions to define intercellular spacing of SACs. Thus, elevated MEGF10 expression in the absence of the translational repressor CPEB3 may account for the defective spatial organization of ON SACs. Our findings uncover for the first time that translational control plays a role in shaping retinal mosaic arrangement.

CPEB3 Deficiency Elevates TRPV1 Expression in Dorsal Root Ganglia Neurons to Potentiate Thermosensation.

Cytoplasmic polyadenylation element binding protein 3 (CPEB3) is a sequence-specific RNA-binding protein that downregulates translation of multiple plasticity-related proteins (PRPs) at the glutamatergic synapses. Activity-induced synthesis of PRPs maintains long-lasting synaptic changes that are critical for memory consolidation and chronic pain manifestation. CPEB3-knockout (KO) mice show aberrant hippocampus-related plasticity and memory, so we investigated whether CPEB3 might have a role in nociception-associated plasticity. CPEB3 is widely expressed in the brain and peripheral afferent sensory neurons. CPEB3-KO mice with normal mechanosensation showed hypersensitivity to noxious heat. In the complete Freund's adjuvant (CFA)-induced inflammatory pain model, CPEB3-KO animals showed normal thermal hyperalgesia and transiently enhanced mechanical hyperalgesia. Translation of transient receptor potential vanilloid 1 (TRPV1) RNA was suppressed by CPEB3 in dorsal root ganglia (DRG), whereas CFA-induced inflammation reversed this inhibition. Moreover, CPEB3/TRPV1 double-KO mice behaved like TRPV1-KO mice, with severely impaired thermosensation and thermal hyperalgesia. An enhanced thermal response was recapitulated in non-inflamed but not inflamed conditional-KO mice, with cpeb3 gene ablated mostly but not completely, in small-diameter nociceptive DRG neurons. CPEB3-regulated translation of TRPV1 RNA may play a role in fine-tuning thermal sensitivity of nociceptors.

Relapsing polychondritis with initial presentations of recurrent negative-pressure pulmonary edema and acute respiratory failure.

Relapsing polychondritis is a rare autoimmune disease causing inflammation in cartilaginous structures and other tissues throughout the body. Negative-pressure pulmonary edema (NPPE) due to laryngeal swelling from relapsing polychondritis is rare and has not been reported. Here, we report a case of relapsing polychondritis in an 18-y-old female who presented with recurrent NPPE and acute respiratory failure, which was diagnosed initially as ARDS during the influenza season. She underwent an emergent tracheotomy to relieve the upper airway obstruction resulting from severe laryngeal edema. A chest radiograph showed diffuse infiltrations, pneumothorax, and pneumomediastinum. The pulmonary infiltrations resolved rapidly in 2 d, and NPPE was diagnosed. Left ear swelling with erythematous change and saddle nose developed during the course of hospitalization, and an ear biopsy demonstrated severe cartilage necrosis. Relapsing polychondritis was diagnosed based on clinical images and pathological findings.