RESUMO
A variation of immunoblotting method (the "Rainbow Western"), permits sequential detection of multiple antigens (MAD) on a single protein blot without stripping off prior antibodies. Because no stripping is involved, immobilized proteins are not lost from the membrane, thus allowing for multiple reprobings of the same membrane with different primary antibodies (≥12), retaining strong signal intensities for all sequential antibody probings. The procedure utilizes horseradish peroxidase (HRPase)-based detection with both a chemiluminescent and colorimetric substrate. Initial incubation of the blot with secondary antibody followed by colorimetric development prior to probing the blot with primary antibodies markedly reduces background in ECL-based detection procedures and permits sequential use of antibodies derived from a single species. In the "Rainbow Western," four different HRPase-colorimetric substrates that produce black, brown, red, and green colors are employed sequentially for detection and simultaneous display of four different antigens on the same membrane. By allowing large amounts of data to be obtained from a single blot, the MAD-immunoblotting and Rainbow Western methods have the potential for researchers to compare the expression of several proteins within a single biological sample. Both techniques could be particularly valuable for analysis of cellular populations that are difficult to isolate in large numbers or of clinical specimens where the amounts of protein samples is minute or only available on a one-time basis.
Assuntos
Antígenos/análise , Western Blotting/métodos , Animais , Anticorpos/química , Colorimetria/métodos , Peroxidase do Rábano Silvestre/química , Humanos , Camundongos , CoelhosRESUMO
OBJECTIVES: Spontaneous bacterial peritonitis (SBP) is associated with high mortality. Early paracentesis (EP) is essential for rapid diagnosis and optimal treatment. The aim of the study is to compare the outcomes of patients with SBP who received EP vs. delayed paracentesis (DP). METHODS: Consecutive patients who were diagnosed with SBP (ascites neutrophil count ≥250 cells/mm(3) and clinical evidence of cirrhosis) <72 h from the first physician encounter at two centers were identified. EP was defined by receiving paracentesis <12 h and DP 12-72 h from hospitalization. Primary outcome was in-hospital mortality. RESULTS: The mean age of 239 patients with SBP was 53±10 years; mean Model for End-Stage Liver Disease (MELD) score was 22±9. In all, 98 (41%) patients who received DP had a higher in-hospital mortality (27% vs. 13%, P=0.007) compared with 141 (59%) who received EP. Furthermore, DP group had longer intensive care days (4.0±9.5 vs. 1.3±4.1, P=0.008), hospital days (13.0±14.7 vs. 8.4±7.4, P=0.005), and higher 3-month mortality (28/76, 37% vs. 21/98, 21%; P=0.03) compared with the EP group. Adjusting for MELD score ≥22 (adjusted odds ratio (AOR)=5.7, 95% confidence interval (CI)=1.8-18.5) and creatinine levels ≥1.5 mg/dl (AOR=3.2, 95% CI=1.4-7.2), DP was associated with increased in-hospital mortality (AOR=2.7, 95% CI=1.3-4.8). Each hour delay in paracentesis was associated with a 3.3% (95% CI=1.3-5.4%) increase in in-hospital mortality after adjusting for MELD score and creatinine levels. CONCLUSIONS: Hospitalized patients with SBP who received DP had a 2.7-fold increased risk of mortality adjusting for MELD score and renal dysfunction. Diagnostic paracentesis performed <12 h from hospitalization in patients with cirrhosis and ascites may improve short-term survival.