RESUMEN
Polyclonal antibody-based enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of retrorsine (1, 351 g/mol), monocrotaline (2, 325 g/mol), and retronecine (3, 155 g/mol) in the parts per billion (ppb) range. A set of three bifunctional linking arms (6-8) was synthesized. By N-alkylation of pyrrolizidine alkaloids (PAs) retrorsine, monocrotaline, and retronecine acetonide (9), six haptens (6.1, 6.2, 7.1, 7.2, 7.9, and 8.9) were synthesized and used to generate rabbit antisera. The resulting anti-retrorsine antiserum gave a 50% inhibition (I50) value of 0.9 +/- 0.2 ppb for retrorsine with detection limits of 0.5-10 ppb. The same ELISA system also detected isatidine (4, retrorsine N-oxide) dihydrate (403 g/mol) with an I50 of 1 ppb and senecionine (5,352 g/mol) with an I50 of 100 ppb. A second monocrotaline-based ELISA detected monocrotaline with an I50 of 36 +/- 9 ppb 2 with detection limits of 5-500 ppb and shows no cross-reactivity with 1 or 5; this ELISA demonstrates the potential for the substrate-specific detection method. A third retronecine-based ELISA detects 3 with an I50 of 3000 +/- 600 ppb (3 +/- 0.6 ppm) and detection limits of 600-10,000 ppb. None of these ELISAs cross-react with the structurally similar swainsonine (10) or lupinine (11) alkaloids. PAs were detected in extracts of Senecio vulgaris and Crotalaria retusa, but not in Lupinus spp., as a demonstration of the ELISA's usefulness.
Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Alcaloides de Pirrolicidina/análisis , Alquilación , Animales , Anticuerpos/inmunología , Antígenos/química , Antígenos/inmunología , Calibración , Reacciones Cruzadas , Haptenos/inmunología , Inmunización , Espectroscopía de Resonancia Magnética , Monocrotalina/análisis , Monocrotalina/inmunología , Plantas/química , Alcaloides de Pirrolicidina/química , Alcaloides de Pirrolicidina/inmunología , Conejos , Sensibilidad y EspecificidadRESUMEN
A syndrome of distal common bile duct obstruction secondary to the fibrotic effects of chronic pancreatitis has been recognized for some time. A group of ten characteristic patients, seven of whom have undergone surgery, is discussed. The diagnostic techniques and surgical procedures are presented, and the results are analyzed. Three patients with the syndrome were not operated upon and one improved spontaneously. The typical patient was a male alcoholic, average age 48 years, with a history of chronic, relapsing pancreatitis and abdominal pain. The most consistently abnormal laboratory value is a markedly elevated alkaline phosphates level. Endoscopic retrograde pancreaticocholangiography and transhepatic cholangiography are the most useful diagnostic procedures. Fifteen per cent of the most useful diagnostic procedures. Fifteen per cent of the patients operated upon required emergent surgery for acute cholangitis and sepsis. Another 29 per cent required prompt intervention for progressive hepatic failure secondary to biliary cirrhosis. The authors advocate an aggressive approach to establish biliary drainage in the presence of acute cholangitis or biliary cirrhosis. If a dilated pancreatic duct can be demonstrated and abdominal pain is the principal problem a direct procedure on the pancreas is needed.