Pancreatic cancer is an aggressive and lethal disease that affects especially older population. Its more relevant tumor marker is CA 19-9 （carbohydrate antigen 19-9）, although it can be elevated in others clinical s...Pancreatic cancer is an aggressive and lethal disease that affects especially older population. Its more relevant tumor marker is CA 19-9 （carbohydrate antigen 19-9）, although it can be elevated in others clinical situations, like cholangitis and cholestasis. Otherwise, a small people subset, like our patient, do not produce this tumor marker, as on blood as in the tumor, because they are incapable to express the Lewis Antigen. Therefore, this case report is about a patient without Lewis Antigen express and CA 19-9 low levels. We will report a rapid disease progression, despite of low CA 19-9, comparing with available data that often show better prognosis in this setting. Conclusion： Low levels of CA 19-9 do not predict good response or better prognosis in patients that do not express Lewis Antigen.展开更多
Interactions between BabA and Lewis b (Leb) related antigens are the best characterized adhesin-receptor interactions in Helicobacter pylori (H pylori). Several mechanisms for the regulation of BabA expression are pre...Interactions between BabA and Lewis b (Leb) related antigens are the best characterized adhesin-receptor interactions in Helicobacter pylori (H pylori). Several mechanisms for the regulation of BabA expression are predicted, including at both transcriptional and translational levels. The formation of chimeric proteins (babA /B or babB /A chimeras) seems to play an especially important role in translational regulation. Chimeric BabB/A protein had the potential to bind Leb; however, protein production was subject to phase variation through slipped strand mispairing. The babA gene was cloned initially from strain CCUG17875, which contains a silent babA1 gene and an expressed babA2 gene. The sequence of these two genes differs only by the presence of a 10 bp deletion in the signal peptide sequence of babA1 that eliminates its translational initiation codon. However, the babA1 type deletion was found only in strain CCUG17875. A few studies evaluated BabA status by immunoblot and confirmed that BabA-positive status in Western strains was closely associated with severe clinical outcomes. BabA-positive status also was associated with the presence of other virulence factors (e.g. cagA-positive status and vacA s1 genotype). A small class of strains produced low levels of the BabA protein and lacked Leb binding activity. These were more likely to be associated with increased mucosal inflammation and severe clinical outcomes than BabA-positive strains that exhibited Leb binding activity. The underlying mechanism is unclear, and further studies will be necessary to investigate how the complex BabA-receptor network is functionally coordinated during the interaction of H pylori with the gastric mucosa.展开更多
文摘Pancreatic cancer is an aggressive and lethal disease that affects especially older population. Its more relevant tumor marker is CA 19-9 （carbohydrate antigen 19-9）, although it can be elevated in others clinical situations, like cholangitis and cholestasis. Otherwise, a small people subset, like our patient, do not produce this tumor marker, as on blood as in the tumor, because they are incapable to express the Lewis Antigen. Therefore, this case report is about a patient without Lewis Antigen express and CA 19-9 low levels. We will report a rapid disease progression, despite of low CA 19-9, comparing with available data that often show better prognosis in this setting. Conclusion： Low levels of CA 19-9 do not predict good response or better prognosis in patients that do not express Lewis Antigen.
基金(in part) National Institutes of Health Grants, R01 DK62813
文摘Interactions between BabA and Lewis b (Leb) related antigens are the best characterized adhesin-receptor interactions in Helicobacter pylori (H pylori). Several mechanisms for the regulation of BabA expression are predicted, including at both transcriptional and translational levels. The formation of chimeric proteins (babA /B or babB /A chimeras) seems to play an especially important role in translational regulation. Chimeric BabB/A protein had the potential to bind Leb; however, protein production was subject to phase variation through slipped strand mispairing. The babA gene was cloned initially from strain CCUG17875, which contains a silent babA1 gene and an expressed babA2 gene. The sequence of these two genes differs only by the presence of a 10 bp deletion in the signal peptide sequence of babA1 that eliminates its translational initiation codon. However, the babA1 type deletion was found only in strain CCUG17875. A few studies evaluated BabA status by immunoblot and confirmed that BabA-positive status in Western strains was closely associated with severe clinical outcomes. BabA-positive status also was associated with the presence of other virulence factors (e.g. cagA-positive status and vacA s1 genotype). A small class of strains produced low levels of the BabA protein and lacked Leb binding activity. These were more likely to be associated with increased mucosal inflammation and severe clinical outcomes than BabA-positive strains that exhibited Leb binding activity. The underlying mechanism is unclear, and further studies will be necessary to investigate how the complex BabA-receptor network is functionally coordinated during the interaction of H pylori with the gastric mucosa.
