| ppGpp | 3'-pyrophosphoryl-guanosine-5'-diphosphate |
|---|---|
| PPRP | polyadenosine diphosphate-ribose polymerase |
| TDP | thermal death point; thoracic duct pressure; thymidine diphosphate; total degradation products |
| UD | ulcerative dermatosis; ulnar deviation; undetermined; underdeveloped; unit dose; urethral dilatation... |
| UDKase | uridine diphosphate kinase |