Schistosomal portal hypertension. Assessment of portal bood flow before and after surgical treatment

Objetivo: Avaliar o fluxo sanguíneo portal na esquistossomose hepato-esplênica e o efeito tardio do tratamento cirúrgico na hemodinâmica portal. Método: Foram estudados 64 pacientes por Doppler dúplex: grupo I (pacientes com hipertensão portal esquistossomótica); grupo II (pacientes submetidos a desconexão ázigo-portal com esplenectomia) e grupo III (pacientes submetidos derivação esplenorrenal distal). Resultados: O fluxo da veia porta foi maior no grupo I (1954,46 ± 693,73ml/min) e foi menor no grupo III (639,55 ± 285,86ml/min), neste correlacionou-se com o tempo pós-operatório (r=-0,67, p=0,0005). O fluxo sangüíneo portal do grupo II (1097,18 ± 342,12ml/min) foi semelhante ao de indivíduos normais. As mesmas alterações foram verificadas com relação ao diâmetro da veia porta nos grupos I, II, e III (cm): 1,46 ± 0,23; 1,12 ± 0,22; 0,93 ± 0,20, respectivamente. Conclusões: Estes dados sugerem que: 1) Existe hiperfluxo portal na fisiopatologia da hipertensão portal esquistossomótica; 2) o tratamento cirúrgico interferiu na hemodinâmica portal, diminuindo o fluxo sangüíneo da veia porta; 3) Esta redução do fluxo sangüíneo portal correlacionou-se com o tempo de seguimento pós-operatório no grupo III mas não no grupo II. _________________________________________________________________________________________ ABSTRACT: Background: Assessment of the portal blood flow in hepatoesplenic schistosomosis and the late effect of surgical treatment on portal hemodynamics. Method: Were studied 64 patients by duplex scan: group I (patients with schistosomal portal hypertension); group II (patients who underwent esophagogastric devascularization and splenectomy); group III (patients who underwent distal splenorenal shunt). Results: Portal vein blood flow was the highest in group I (1954.46 ± 693.73 ml/min) and the lowest in group III (639.55 ± 285.86 ml/min) which correlated with follow-up time (r=-0.67, p=0.0005). Group II portal flow (1097.18 ± 342.12 ml/min) was similar to control. The same changes were seen in portal vein diameter in groups I, II, III (cm): 1.46 ± 0.23, 1.12 ± 0.22, 0.93 ± 0.20, respectively. Conclusions: Our data suggest that: 1) there is portal overflow in the physiopathology of schistosomal portal hypertension; 2) surgical treatment has interfered in hemodynamic reducing portal venous blood flow; 3) portal venous blood flow reduction correlated with follow-up time in group III but not in group II

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements