Determinants for a low dose of alteplase and its relationship to a lower intracerebral bleeding risk in acute ischemic stroke.

Background: Factors for the utilization of intravenous thrombolysis with a low-dose of alteplase (0.6mg/kg) and whether the low-dose of alteplase could reduce the risk of intracerebral bleeding in acute ischemic stroke (AIS) remains uncertain. Aims: We aimed to investigate determinants for the utilization of intravenous thrombolysis with a low-dose of alteplase. We further assessed the association between the low-dose of alteplase and the intracerebral bleeding risk in AIS patients. Method: We included AIS patients who received intravenous thrombolysis using alteplase in this multicenter retrospective observational study. We investigated the association between baseline characteristics and the utilization of a low-dose of alteplase to identify determinants. We assessed the association of the low-dose of alteplase with the risk of symptomatic intracranial hemorrhage (sICH) using a multivariable logistic regression model. We further compared the rate of sICH and any ICH in patients in the low-dose group to those in the standard-dose group, using propensity score-matching data. Results: A total of 506 AIS patients were included in this study. The mean age was 67 (interquartile range [IQR] 59-75), and 178 (35.2%) were women. A total of 96 patients were treated with the low-dose. Age (adjusted odds ratio [OR] 1.02, 95% confidence interval [CI] 1.00 -1.04, p = 0.042), having a previous ischemic stroke (adjusted OR 2.01, 95%CI 1.11 - 3.64 p = 0.021) and increasing baseline systolic blood pressure (adjusted OR 1.12, 95%CI 1.00 - 1.26, p = 0.049) were determinants for the utilization of the low-dose. Multivariable logistic regression analysis showed that the low-dose was significantly associated with a reduced risk of sICH (adjusted OR 0.13, 95%CI 0.03 - 0.62, p = 0.01). Propensity score analysis showed that the rate of sICH was significantly lower in the low-dose group compared to standard-dose group (2 [2.3%] vs 10 [11.4%], p = 0.032). There was no significant difference in the rate of any ICH between two groups (14 [15.9%] vs 18 [20.5%], p = 0.434). Conclusions: Patients with increasing age, a higher baseline systolic blood pressure, and previous ischemic stroke were at a higher odd of receiving a low-dose of alteplase. The low-dose was associated with a lower risk of developing symptomatic intracranial hemorrhage.

Six-month follow-up of functional status in discharged patients with coronavirus disease 2019.

BACKGROUND: The long-term functional outcome of discharged patients with coronavirus disease 2019 (COVID-19) remains unresolved. We aimed to describe a 6-month follow-up of functional status of COVID-19 survivors. METHODS: We reviewed the data of COVID-19 patients who had been consecutively admitted to the Tumor Center of Union Hospital (Wuhan, China) between 15 February and 14 March 2020. We quantified a 6-month functional outcome reflecting symptoms and disability in COVID-19 survivors using a post-COVID-19 functional status scale ranging from 0 to 4 (PCFS). We examined the risk factors for the incomplete functional status defined as a PCFS > 0 at a 6-month follow-up after discharge. RESULTS: We included a total of 95 COVID-19 survivors with a median age of 62 (IQR 53-69) who had a complete functional status (PCFS grade 0) at baseline in this retrospective observational study. At 6-month follow-up, 67 (70.5%) patients had a complete functional outcome (grade 0), 9 (9.5%) had a negligible limited function (grade 1), 12 (12.6%) had a mild limited function (grade 2), 7 (7.4%) had moderate limited function (grade 3). Univariable logistic regression analysis showed a significant association between the onset symptoms of muscle or joint pain and an increased risk of incomplete function (unadjusted OR 4.06, 95% CI 1.33-12.37). This association remained after adjustment for age and admission delay (adjusted OR 3.39, 95% CI 1.06-10.81, p = 0.039). CONCLUSIONS: A small proportion of discharged COVID-19 patients may have an incomplete functional outcome at a 6-month follow-up; intervention strategies are required.

Prevalence and outcomes of re-positive nucleic acid tests in discharged COVID-19 patients.

The prevalence and outcomes of patients who had re-activation of coronavirus disease 2019 (COVID-19) after discharge remain poorly understood. We included 126 consecutively confirmed cases of COVID-19 with 2-month follow-up data after discharge in this retrospective study. The upper respiratory specimen using a reverse-transcription polymerase chain reaction test of three patients (71 years [60-76]) were positive within 11-20 days after their discharge, with an event rate of 19.8 (95%CI 2.60-42.1) per 1,000,000 patient-days. Moreover, all re-positive patients were asymptomatic. Our findings suggest that few recovered patients may still be virus carriers even after reaching the discharge criteria.

Treadmill exercise enhances therapeutic potency of transplanted bone mesenchymal stem cells in cerebral ischemic rats via anti-apoptotic effects.

BACKGROUND: The transplantation of bone marrow stromal cells (MSCs) has proved to ameliorate ischemic brain injury in animals, but most transplanted MSCs undergo apoptosis in the ischemic penumbra, greatly compromising the therapeutic value of this treatment. Meanwhile, cell apoptosis can be inhibited by post-ischemia exercise which has been demonstrated to improve the expression of related anti-apoptotic proteins. The present study investigated whether treadmill exercise enhances the neuroprotective effects of transplanted MSCs in a rat experimental stroke model. RESULT: Rats were subjected to 2-h middle cerebral artery occlusion (MCAO). Twenty-four hours after reperfusion, they were assigned randomly to receive no MSCs treatment and no exercise (control group), intravenous transplantation of MSCs and treadmill exercise (MSCs + Ex group), MSCs transplantation only (MSCs group) and treadmill exercise only (Ex group). Neurological assessment, TUNEL staining and western blot were performed. Compared with the MSCs group and Ex group, the MSCs + Ex group reported markedly improved neurological function, significantly decreased apoptotic cells, and increased expressions of survivin and bcl-2 (p < 0.05 or p < 0.01, respectively). Interestingly, the treadmill exercise significantly inhibited the apoptosis of transplanted MSCs. As a result, the number of engrafted MSCs in the MSCs + Ex group was significantly higher than that in the MSC group (p < 0.01). CONCLUSIONS: Treadmill exercise enhances the therapeutic potency of MSCs by improving neurological function and possibly inhibiting the apoptosis of neuron cells and transplanted MSCs. These effects may involve an increased expression of survivin and bcl-2.

[The effects of adipose-derived stem cells transplantation on the expression of TGF-ß1 in rat brain after cerebral ischemia].

AIM: To explore the mechanisms of adipose-derived stem cells (ADSCs) transplanting induced angiogenesis in rat brain after focal cerebral ischemia. METHODS: 108 male adult Sprague-Dawley rats were randomly assigned into 4 groups: sham-operated group, middle cerebral artery occlusion (MCAO) group, vehicle group and MCAO+ADSCs-treated group. Rat's focal cerebral ischemia model was established by right middle cerebral artery occlusion (MCAO) with modified Longa's method. ADSCs were pre-labeled by CFSE before the transplantation into the rat brain. At 1 d after MCAO, 30 µL cell suspension which contained 1×10(6); ADSCs was injected into the lateral ventricle of MCAO+ADSCs-treated rats, and the same dose of PBS was given to the rats of vehicle group as control. At 4 d, 7 d and 14 d after MCAO, rats were decapitated to detect the TGF-ß1 expression in the infarct area. RESULTS: The expression of TGF-ß1 in brain tissues in MCAO+ADSCs-treated group was significantly higher than MCAO group and vehicle group at 4 d, 7 d and 14 d after MCAO, respectively. After transplantation into MCAO rats, ADSCs could survive and express TGF-ß1 in the ischemic brain. CONCLUSION: These data suggest that ADSCs transplantation can promote revascularization in cerebral ischemic rats, partly by promoting TGF-ß1 expression in the brain.

[Effects of adipose-derived stem cells transplantation on the neuronal apoptosis and the expression of Bcl-2 and caspase-12 in the brain post focal cerebral ischemia in rats].

AIM: To investigate the effects of adipose-derived stem cells (ADSCs) transplantation on neuronal apoptosis in the brain after focal cerebral ischemia in rats. METHODS: 72 male adult Sprague-Dawley rats were randomly divided into 4 groups: Sham-operated group , Middle cerebral artery occlusion (MCAO) group, Vehicle group and ADSC-treated group (n=18). MCAO model was established with the modified Longa's method. One day after right MCAO, 30 µL of cell suspension containing 1×10(6); cells were injected into the lateral ventricle of ADSC-treated group and the same dose of PBS was given to the vehicle group. At 4 d, 7 d and 14 d after MCAO, the apoptosis of neuron was detected by terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling (TUNEL) method and the expression of Bcl-2 and caspase-12 in ischemic region was detected by immunohistochemistry and RT-PCR. RESULTS: TUNEL-positive cells in ischemic region of ADSC-treated group were less than that in MCAO group and Vehicle group at 4 d, 7 d and 14 d post MCAO (P<0.05). Compared with MCAO group and Vehicle group, the expression of Bcl-2 significantly up-regulated while caspase-12 expression significantly decreased in ADSC-treated group at any time point post MCAO (P<0.05). CONCLUSION: The transplantation of ADSCs can reduce neuronal apoptosis of rats with cerebral ischemic injury partly by promoting the expression of Bcl-2 which participates in apoptotic signals after mitochondrial damage and inhibiting the expression of caspase-12 which mediates endoplasmic reticulum (ER) stress-induced apoptosis.

[Interleukin-10 inhibits the expression of interferon regulatory factor-1 with anoxia-reoxygenation in vitro].

AIM: to explore the effects of IL-10 on the expression of interferon regulatory factor-1 (IRF-1) after anoxia-reoxygenation in vitro. METHODS: brain microvascular endothelial cells (BMEC) and neutrophil (PMN) were co-cultured exposed to eight hours of anoxia followed by two hours of reoxygenation to establish anoxia-reoxygenation model in vitro. The co-cultured BMEC and PMN were randomly divided into the following groups: normal group, anoxia-reoxygenation group, 1 microg/L IL-10 treatment group, 10 microg/L IL-10 treatment group, and 30 microg/L IL-10 treatment group. The expression of IRF-1 was detected by RT-PCR and Western blot method. RESULTS: the expression of IRF-1 was significantly upregulated after anoxia-reoxygenation. IL-10 inhibited the expression of IRF-1 in a dose-dependent manner compared with anoxia-reoxygenation group, and the peak of inhibitive effects occurred at the dose of 30 µg/L. CONCLUSION: IL-10 can inhibit the expression of interferon regulatory factor-1 with anoxia-reoxygenation in vitro.

[The effects of adipose-derived stem cell transplantation on the expression of IL-10 and TNF-alpha after cerebral ischaemia in rats].

AIM: To explore the effects of adipose-derived stem cell (ADSC) transplantation on the expression of IL-10 amd TNF-alpha after cerebral ischaemia in Middle cerebral artery occlusion (MCAO) rats. METHODS: 72 male adult Sprague-Dawley rats were randomly divided into 4 groups: sham group, MCAO group, Vehicle group and ADSC group (n=18). Rat's cerebral ischemia model was established by MCAO with Longa's method. ADSC were labeled by DAPI before transplantation. One day after MCAO, 30 microL of cell suspension containing 1 x 10(6); ADSCs were injected into the lateral ventricle of ADSC group and the same dose of PBS was given to the Vehicle group. At day 4, day 7 and day 14 after MCAO, the rats were decapitated to detect the expression of IL-10 and TNF-alpha in ischaemic rat's brain by ELISA, immunohistochemistry and RT-PCR. RESULTS: Compared with sham group, the expression of IL-10 and TNF-alpha significantly up-regulated at 4 d, 7 d of MCAO group(P<0.05). There was no statistical difference of IL-10 and TNF-alpha expression between MCAO and vehicle group ant any time point(P>0.05). Compared with Vehicle group, the expression of IL-10 significantly up-regulated while TNF-alpha expression significantly decreased of ADSC-treated group at any timepoint post MCAO(P<0.05). CONCLUSION: The transplantation of ADSC could up-regulate the expression of IL-10 and down-regulate the expression of TNF-alpha in MCAO rat's brain, which might contribute to its protective role upon cerebral ischaemia.

[Inhibiting effects of interleukin-10 on expression of E-selectin and L-selectin in cerebral ischemia-reperfusion: experiment with rats].

OBJECTIVE: To investigate the inhibiting effects of interleukin-10 (IL-10) on the expression of E-selectin and L-selectin in cerebral ischemia-reperfusions. METHODS: Seventy-two adult male Sprague-Dawley rats were randomly divided into 4 equal groups, cerebral ischemia-reperfusion (I/R) group undergoing middle cerebral artery occlusion with Longa's thread method, IL-10 group undergoing lateral ventricle injection of IL-10 after the establishment of I/R model, Vehicle group undergoing lateral ventricle injection of normal saline after the establishment of I/R model, and sham operation (Sham) group. Twenty-four hours later the rats were killed with their brains taken out. Immunohistochemistry, RT-PCR and Western blotting were used to detect the mRNA and protein expression of E-selectin and L-selectin. RESULTS: The E-selectin and L-selectin expression levels of the I/R group were significantly up-regulated compared with the Sham group (both P < 0.05). The numbers of E-selectin and L-selectin positive vessels of the IL-10 group were 18.8 +/- 1.9/10 HP fields and 15.8 + 2.4/10 HP fields respectively, both significantly less than those of the vehicle group (24.7 +/- 2.4/10 HP fields and 20.9 + 3.3/10 HP fields respectively, both P < 0.05). The E-selectin and L-selectin gene mRNA expression levels of the IL-10 group were (0.431 +/- 0.029) and (0.318 +/- 0.048) respectively, both significantly lower than those of the Vehicle group [(0.497 +/- 0.019) and (0.433 +/- 0.087) respectively, both P < 0.05]. The E-selectin and L-selectin protein expression levels of the IL-10 group were (0.349 +/- 0.037) and (0.296 +/- 0.035) respectively, both significantly lower than those of the Vehicle group [(0.421 +/- 0.043,) and (0.348 +/- 0.044) respectively, both P < 0.05]. CONCLUSIONS: IL-10 suppresses the expression of E-selectin and L-selectin in cerebral ischemia-reperfusion.

[Effects of adipose-derived stem cell transplantation on the angiogenesis and the expression of bFGF and VEGF in the brain post focal cerebral ischemia in rats].

AIM: To investigate the effects of adipose-derived stem cell (ADSC) transplantation on the angiogenesis in the brain post focal cerebral ischemia in rats. METHODS: 72 male adult Sprague-Dawley rats were randomly divided into 4 groups: sham-operated group, middle cerebral artery occlusion (MCAO) group, vehicle group and MCAO+ADSC-treated group (n=18). A permenant focal cerebral ischemia model was established with the modified Longa's method. ADSC were labeled by DAPI before transplantation. One day after right MCAO, 30 muL of cell suspension containing 1x10(6) cells were injected into the lateral ventricle of MCAO+ADSC-treated group and the same dose of PBS was given to the vehicle group. On D4, D7 and D14 after MCAO, the rats were killed to detect the regeneration of microvessel and the expression of bFGF and VEGF in ischemic region by immunohistochemistry and RT-PCR. RESULTS: A lot of microvessel proliferate in the injured cortex reached peak in 2 weeks. The microvessel density in the brain tissues of rats treated with ADSC was higher than that in MCAO group and vehicle group (P<0.01). The expression of bFGF and VEGF in the brain tissues of MCAO+ADSC-treated group was higher than that in MCAO group and vehicle group on D4, D7 and D14 post MCAO. CONCLUSION: The transplantation of ADSC can promote the revascularization of cerebral ischemia in rats partly by enhancing bFGF and VEGF synthesis in brain.

[Effects of bone marrow-derived mesenchymal stem cells transplantation on recovery of neurological functions and expression of synaptophysin in focal cerebral infarction in rats].

AIM: To investigate the effects of bone marrow-derived mesenchymal stem cells (BMSC) transplantation on the recovery of neurological functions and the expression of synaptophysin in focal cerebral infarction in rats. METHODS: 72 male adult Sprague-Dawley rats were randomly divided into 4 groups (18 in each group): shamoperated group, middle cerebral artery occlusion (MCAO) roup,vehicle group and MCAO+BMSC-treated group. A permanent focal cerebral ischemia model was established using modified Longa's method. BMSC was labeled by DAPI before the transplantation. One day after right middle cerebral artery occlusion(MCAO), 1 x 10(6) cells were injected into the lateral ventricle of rats in BMSCs-treated group and the same dose of PBS was given to the rats in vehicle group. Before sacrificed and at 4 d, 7 d and 14 d after MCAO, the neurological functions were tested by balance beam, rota-rod and screen prehensile and the synaptophysin was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemical method. RESULTS: DAPI stained positive cells were observed around the cerebral infarcted area in the BMSC-treated group. Compared with the MCAO group and the vehicle group,the neurological functions in BMSC-treated group were better on 7 d and 14 d after MCAO (P<0.05 or P<0.01), and the synaptophysin around the cerebral infarcted area was significantly upregulated on 4 d, 7 d and 14 d after MCAO (all P<0.01). CONCLUSION: BMSC transplantation can improve the neurological functions by upregulating the expression of synaptophysin after MCAO in rats.

[The effect of interleukin-10 on neurocyte apoptosis in cerebral ischemia in rats].

AIM: To investigate the effect of interleukin-10 on neurocyte apoptosis in cerebral ischemia in rats. METHODS: 36 adult male Sprague-Dawley rats were randomly assigned into 3 groups: sham operation group, middle cerebral artery occlusion(MCAO) group and MCAO+interleukin-10 treatment group. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) staining was used to detect in situ cell apoptosis, immunohistochemical staining and RT-PCR were used to detect the expression of proapoptotic gene Fas, Fas ligand (FasL) and caspase-3 in peri-infarct, respectively. RESULTS: Cerebral ischemia significantly induced neurocyte apoptosis and upregulated the expression of Fas, FasL and caspase-3, repcetively (P<0.05). IL-10 treatment significantly inhibited neurocyte apoptosis, and suppressed the expression of proapoptotic gene FasL and caspase-3, repcetively (P<0.05), but had no obvious effect on Fas expression (P>0.05). CONCLUSION: IL-10 can suppress neurocyte apoptosis in cerebral ischemia, whose mechanisms seemed related to inhibiting the expression of proapoptotic gene FasL and caspase-3.