Coronavirus disease 2019 and stroke in Iran: a case series and effects on stroke admissions

OBJECTIVE

The coronavirus disease 2019 pandemic has affected healthcare systems around the globe and massively impacted patients with various non-infectious, life-threatening conditions. Stroke is a major neurological disease contributing to death and disability worldwide, and is still an ongoing issue during the pandemic. Here we investigate the impact of the coronavirus disease 2019 outbreak on stroke manifestations, treatment courses, the outcome of stroke patients, and the hospitalization rate in a referral center for stroke management in Tehran, Iran.

METHODS

We extracted data regarding 31 stroke patients (10 patients with laboratory-confirmed coronavirus disease 2019) and compared the demographic and pathological characteristics of the patients with or without coronavirus disease 2019 infection. The association of demographic/pathological characteristics of stroke patients during the coronavirus disease 2019 pandemic and a corresponding period during the previous year (49 patients) and an earlier period during the same year as the pandemic (50 patients) was also evaluated.

RESULTS

The absolute number of admissions decreased about 40% during the coronavirus disease 2019 pandemic. Except for the stroke severity (P = 0.002), there were no significant changes in the demographic and pathological characteristics of the stroke patients during the three studied periods. A significantly higher mean of age (75.60 ± 9.54 versus 60.86 ± 18.45; P = 0.007), a significant difference in the type of stroke (P = 0.046), and significantly higher stroke severity (P = 0.024) were observed in stroke patients with coronavirus disease 2019 compared with those of stroke patients without coronavirus disease 2019. Treatment approaches, duration of hospitalization, and mortality rates did not differ significantly.

CONCLUSIONS

This report shows that the pandemic caused the number of acute stroke admissions to plummet compared to other periods. Although the pandemic did not affect the treatment plans and care of the patients, stroke cases with coronavirus disease 2019 had higher age, more large vessel ischemic stroke, and more severe stroke. Further studies are urgently needed to realize the probable interaction of the coronavirus disease 2019 pandemic and the neurologic disease.

Effects of Low-Intensity Continuous Ultrasound on Hematological Parameters of Rats

BACKGROUND

Low intensity ultrasound (US) has some well-known bio-effects which are of great importance to be considered. Objective: We conducted the present study to investigate the effects of low intensity continuous ultrasound on blood cells count in rat.

METHODS

Rats were anesthetized and blood samples were collected before US exposure. Then, they were exposed to US with nominal intensity of 0.2 W/cm2 at frequency of 3 MHz for a period of 10 minutes and this protocol was repeated for 7 days. Twenty four hours after the last US exposure, secondary blood samples were collected and the changes in blood parameters were evaluated.

RESULTS

Analysis revealed that platelets, hematocrit (HCT) and hemoglobin (HGB) were significantly different between experimental and sham groups but no difference between sham and control groups was observed. The results show that HCT and HGB of exposed rats were significantly reduced. Conclusion: This study shows that low intensity US may lead to side effects for hematological parameters such as reduction in the levels of HGB and HCT.

Beclin 1 and autophagy are required for the tumorigenicity of breast cancer stem-like/progenitor cells

Malignant breast tissue contains a rare population of multi-potent cells with the capacity to self-renew; these cells are known as cancer stem-like cells (CSCs) or tumor-initiating cells. Primitive mammary CSCs/progenitor cells can be propagated in culture as floating spherical colonies termed ‘mammospheres'. We show here that the expression of the autophagy protein Beclin 1 is higher in mammospheres established from human breast cancers or breast cancer cell lines (MCF-7 and BT474) than in the parental adherent cells. As a result, autophagic flux is more robust in mammospheres. We observed that basal and starvation-induced autophagy flux is also higher in aldehyde dehydrogenase 1-positive (ALDH1⁺) population derived from mammospheres than in the bulk population. Beclin 1 is critical for CSC maintenance and tumor development in nude mice, whereas its expression limits the development of tumors not enriched with breast CSCs/progenitor cells. We found that decreased survival in autophagy-deficient cells (MCF-7 Atg7 knockdown cells) during detachment does not contribute to an ultimate deficiency in mammosphere formation. This study demonstrates that a prosurvival autophagic pathway is critical for CSC maintenance, and that Beclin 1 plays a dual role in tumor development.

Efficacy of adjuvant chemotherapy according to Prion protein expression in patients with estrogen receptor-negative breast cancer

BACKGROUND

Prion protein (PrPc) has been previously reported to be associated with resistance to proapoptotic stimuli. We evaluated whether the expression of PrPc was associated with the resistance to adjuvant chemotherapy in patients with estrogen receptor (ER) -negative breast cancer.

PATIENTS AND METHODS

The expression of PrPc by primary tumors was assessed by immunohistochemistry in a series of 756 patients included in two randomized trials that compared anthracycline-based chemotherapy to no chemotherapy. The PrPc expression was correlated with ER expression and the benefit of adjuvant chemotherapy was assessed according to PrPc expression in patients with ER-negative tumors.

RESULTS

Immunostaining analysis showed that PrPc was mainly expressed by myoepithelial cells in normal breast tissue. Tissue microarray analysis from 756 breast tumors showed that PrPc was associated with ER-negative breast cancer subsets (P < 0.001). Adjuvant chemotherapy was not associated with a significant risk reduction for death in patients with ER-negative/PrPc-positive disease [adjusted hazard ratio (HR) for death = 0.98, 95% confidence interval (CI) 0.45-2.1, P = 0.95], while it decreased the risk for death (HR = 0.39, 95% CI 0.2-0.74, P = 0.004) in patients with ER-negative/PrPc-negative tumors.

CONCLUSION

These data indicate that ER-negative/PrPc-negative phenotype is associated with a high sensitivity to adjuvant chemotherapy.

Imatinib enhances human melanoma cell susceptibility to TRAIL-induced cell death: Relationship to Bcl-2 family and caspase activation

In order to define genetic determinants of primary and metastatic melanoma cell susceptibility to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), we have applied oligonucleotide microarrays to TRAIL-sensitive primary T1 cells and TRAIL-resistant metastatic G1 cells treated or not with TRAIL. T1 and G1 cells are isogenic melanoma cell subclones. We examined 22 000 spots, 4.2% of which displayed differential expression in G1 and T1 cells. Cell susceptibility to TRAIL-mediated apoptosis was found to be correlated with gene expression signatures in this model. Some of the differentially expressed genes were identified as involved in ATP-binding and signaling pathways, based on previously published data. Further analysis provided evidences that c-kit was overexpressed in G1 cells while it was absent in T1 cells. The c-kit inhibitor, imatinib, did not restore TRAIL sensitivity, excluding a role for c-kit in TRAIL resistance in G1 cells. Surprisingly, imatinib inhibited cell proliferation and TRAIL-mediated apoptosis in melanoma cells. We investigated the possible involvement of several molecules, including c-ABL, platelet-derived growth factor receptor (PDGFR), cellular FADD-like interleukin-1 alpha-converting enzyme-like inhibitory protein (c-FLIP)(L/S), Fas-associated DD kinase, p53, p21(WAF1), proteins of B-cell leukemia/lymphoma 2 (Bcl-2) family and cytochrome c. Imatinib did not modulate the expression or activation of its own targets, such as c-ABL, PDGFRalpha and PDGFRbeta, but it did affect the expression of c-FLIP(L), BCL2-associated X protein (Bax) and Bcl-2. Moreover, c-FLIP(L) knockdown sensitized T1 cells to TRAIL-mediated apoptosis, with a sensitivity similar to that of cells previously treated with imatinib. More notably, we found that the resistance to TRAIL in G1 cells was correlated with constitutive c-FLIP(L) recruitment to the DISC and the inhibition of caspase 8, 3 and 9 processing. Moreover, c-FLIP(L) knockdown partly restored TRAIL sensitivity in G1 cells, indicating that the expression level of c-FLIP(L) and its interaction with TRAIL receptor2 play a crucial role in determining TRAIL resistance in metastatic melanoma cells. Our results also show that imatinib enhances TRAIL-induced cell death independently of BH3-interacting domain death agonist translocation, in a process involving the Bax:Bcl-X(L) ratio, Bax:Bcl-X(L)/Bcl-2 translocation, cytochrome c release and caspase activation. Our data indicate that imatinib sensitizes T1 cells by directly downregulating c-FLIP(L), with the use of an alternative pathway for antitumor activity, because PDGFRalpha is not activated in T1 cells and these cells do not express c-kit, c-ABL or PDGFRbeta. Caspase cascade activation and mitochondria also play a key role in the imatinib-mediated sensitization of melanoma cells to the proapoptotic action of TRAIL.

Reduction of the prenatal hypoxic-ischemic brain edema with noscapine

Cytotoxic free radicals and release of several neurotransmitters such as bradykinin contribute to the pathogenesis of hypoxic-ischemic brain damage. We have studied the efficacy of noscapine, an opium alkaloid and a bradykinin antagonist, in reducing post-hypoxic-ischemic damage in developing brain of 7-d-old rat pups. Hypoxic-ischemic injury to the right cerebral hemisphere was produced by legation of the right common carotid artery followed by 3 h of hypoxia with 8% oxygen. Thirty to 45 min before hypoxia the rat pups received noscapine (dose = 0.5-2 mg/kg) or saline. Pups were scarified at 24 h post recovery for the assessment of cerebral damage by histological methods. Our results showed that noscapine was an effective agent in reducing the extent of brain injury after hypoxic-ischemic insult to neonatal rats. Therefore, it is concluded that noscapine may be a useful drug in the managements of patients after stroke.