Gulf Coast Regional Blood Center

About: Gulf Coast Regional Blood Center is a based out in . It is known for research contribution in the topics: Population & Allele. The organization has 6297 authors who have published 6917 publications receiving 198369 citations.

A simple salting out procedure for extracting DNA from human nucleated cells

Abstract: One of the obstacles encountered when extracting DNA from a large number of samples is the cumbersome method of deprotein-izing cell digests with the hazardous organic solvents phenol and isochloroform. Several other non-toxic extraction procedures have been published, but require either extensive dialysis (1) or the use of filters (2). A rapid, safe and inexpensive method was developed to simplify the deprotein-ization procedure. This method involves salting out of the cellular proteins by dehydration and precipitation with a saturated NaCl solution. Buffy coats of nucleated cells obtained from anticoagulated blood (ACD or EDTA) were resuspended in 15 ml polypropylene centrifugation tubes with 3 ml of nuclei lysis buffer (10 mM Tris-HCl t 400 mM NaCl and 2 mM Na 2 EDTA, pH 8.2). The cell lysates were digested overnight at 37°C with 0.2 ml of 10Z SDS and 0.5 ml of a protease K solution (1 mg protease K in 1Z SDS and 2 mM Na2EDTA). After digestion was complete, 1 ml of saturated NaCl (approximately 6M) was added to each tube and shaken vigorously for 15 seconds, followed by centrifugation at 2500 rpm for 15 minutes. The precipitated protein pellet was left at the bottom of the tube and the supernatant containing the DNA was transferred to another 15 ml polypropylene tube. Exactly 2 volumes of room temperature absolute ethanol was added and the tubes inverted several times until the DNA precipitated. The precipitated DNA strands were removed with a plastic spatula or pipette and transferred to a 1.5 ml microcentrifuge tube containing 100-200 pi TE buffer (10 mM Tris-HCl, 0.2 mM Na 2 EDTA, pH 7.5). The DNA was allowed to dissolve 2 hours at 37°C before quantitating. The DNA obtained from this simple technique yielded quantities comparable to those obtained from phenol-chloroform extractions. The 260/280 ratios were consistently 1.8-2.0, demonstrating good deproteinization. Restrictions were performed using a number of different enzymes requiring high, medium or low salt concentrations, all resulting in complete restriction. This procedure has been used in our laboratory on several thousand blood samples for parentage, population and forensic studies. This technique is used with our non-isotopic hybridization procedures (3) rendering the entire process of RFLP analysis free of toxic materials.

An assay for circulating antibodies to a major etiologic virus of human non-A, non-B hepatitis

Abstract: A specific assay has been developed for a blood-borne non-A, non-B hepatitis (NANBH) virus in which a polypeptide synthesized in recombinant yeast clones of the hepatitis C virus (HCV) is used to capture circulating viral antibodies. HCV antibodies were detected in six of seven human sera that were shown previously to transmit NANBH to chimpanzees. Assays of ten blood transfusions in the United States that resulted in chronic NANBH revealed that there was at least one positive blood donor in nine of these cases and that all ten recipients seroconverted during their illnesses. About 80 percent of chronic, post-transfusion NANBH (PT-NANBH) patients from Italy and Japan had circulating HCV antibody; a much lower frequency (15 percent) was observed in acute, resolving infections. In addition, 58 percent of NANBH patients from the United States with no identifiable source of parenteral exposure to the virus were also positive for HCV antibody. These data indicate that HCV is a major cause of NANBH throughout the world.

Effectiveness of convalescent plasma therapy in severe COVID-19 patients.

Abstract: Currently, there are no approved specific antiviral agents for novel coronavirus disease 2019 (COVID-19). In this study, 10 severe patients confirmed by real-time viral RNA test were enrolled prospectively. One dose of 200 mL of convalescent plasma (CP) derived from recently recovered donors with the neutralizing antibody titers above 1:640 was transfused to the patients as an addition to maximal supportive care and antiviral agents. The primary endpoint was the safety of CP transfusion. The second endpoints were the improvement of clinical symptoms and laboratory parameters within 3 d after CP transfusion. The median time from onset of illness to CP transfusion was 16.5 d. After CP transfusion, the level of neutralizing antibody increased rapidly up to 1:640 in five cases, while that of the other four cases maintained at a high level (1:640). The clinical symptoms were significantly improved along with increase of oxyhemoglobin saturation within 3 d. Several parameters tended to improve as compared to pretransfusion, including increased lymphocyte counts (0.65 × 109/L vs. 0.76 × 109/L) and decreased C-reactive protein (55.98 mg/L vs. 18.13 mg/L). Radiological examinations showed varying degrees of absorption of lung lesions within 7 d. The viral load was undetectable after transfusion in seven patients who had previous viremia. No severe adverse effects were observed. This study showed CP therapy was well tolerated and could potentially improve the clinical outcomes through neutralizing viremia in severe COVID-19 cases. The optimal dose and time point, as well as the clinical benefit of CP therapy, needs further investigation in larger well-controlled trials.