Low-dose intravenous recombinant tissue plasminogen activator in acute ischemic stroke without large vessel occlusion screened by 3T MRI.

OBJECTIVE: Globally, there are more than six million deaths due to cerebrovascular disease, which is the second leading cause of death. Although the imaging findings of magnetic resonance imaging (MRI) are more accurate than computed tomography for acute ischemic stroke (AIS), it is uncommon in recombinant tissue plasminogen activator (rTPA) treatment. Alteplase is not only strongly recommended treatment for acute ischemic stroke within 4.5 hours, but also decreases the disability and mortality rate. Besides, low-dose rTPA was associated with significant reductions in symptomatic intracerebral hemorrhage (sICH), compared with standard one. However, the benefits of low-dose rTPA for the treatment of AIS without large vessel occlusion (LVO) have not been fully demonstrated. We evaluated whether the low-dose rTPA in AIS without LVO could improve prognosis in patients three months post-treatment. PATIENTS AND METHODS: This was a cross-sectional study on patients with AIS treated within 4.5 hours of symptom onset admitted to Can Tho S.I.S General Hospital between February 2019 and July 2021. The eligibility criteria were patients aged > 18 years treated with low-dose rTPA (0.6 mg/kg) and screened by 3T MRI. Patients with a pre-hospital modified Rankin score (mRS) ≥ 2 points, intracranial hemorrhage, LVO, or ≥ 3 microbleeds on brain MRI were excluded. The primary outcomes were the favorable outcome rate at three months and safety, which were evaluated by the rates of intracranial hemorrhage and mortality at three months. RESULTS: This study enrolled 92 eligible patients between February 2019 and July 2021. Their National Institute of Health Stroke Scale (NIHSS) scores were 7.5 ± 3.7 at admission, 3.3 ± 3.5 at discharge or seven days after discharge, and 2.2 ± 2.8 at three months. Their mRS were 2.9 ± 0.8 at admission, 1.4 ± 1.3 at discharge or seven days after discharge, and 1.1 ± 1.1 at three months. Elevated cardiac enzymes, age ≥ 75 years, and body mass index ≥ 25 were associated with increased poor outcomes at three months. While AIS was more common in men than women, a similar number of men (33.3%) and women had poor mRS. Three patients had complications associated with low-dose rTPA treatment: one (1.1%) had intracranial hemorrhage, one (1.1%) had new infarcts, and one (1.1%) had gastrointestinal bleeding. No deaths occurred within three months. CONCLUSIONS: Our study indicates the efficacy and safety of low-dose rTPA treatment for AIS without LVO within 4.5 hours. Patient selection for rTPA by 3T MRI decreased complications and mortality.

Isolation of a human B lymphocyte membrane protein with Ia-like properties.

A rapid method for isolation of a major surface membrane glycoprotein from whole, unfractionated cultured human B lymphoblasts is described. After detergent solubilization the method uses gel filtration followed by affinity chromatography on Sepharose Con A and then alkaline acrylamide gel electrophoresis. Specific high-titre, rabbit antisera to the isolated protein reacted with cultured and normal peripheral blood B lymphocytes, as well as peritoneal macrophages from a renal dialysis patient. The antisera selectively inhibited the mixed lymphocyte reaction at high dilution. The protein reacted with a heterologous antiserum to HL-B antigens and contained subunits of MW 33 000 and 27 000. Resolution of the subunits, however, required a discontinuous SDS gel system. These properties indicate its similarity to murine Ia antigens. The protein was not associated with beta 2 microglobulin and showed no structural or antigenic similarity to the major erythocyte glycoprotein, glycophorin. Antisera to the protein failed to precipitate surface-radiodinated components from similarily treated extracts of cultured human T lymphoblasts. This method now makes available a reference membrane glycoprotein from a differentiated, nucleated human cell in sufficient purity and quantity for kinetic and biosynthetic studies.