PubMed Health⌕ Search

Biomedical subjects

Kenneth Graham

Publications and source records attributed to Kenneth Graham.

3 recordsLinked to original sources
PubMed2007

Surgical interventions for the treatment of radiation-induced alopecia in pediatric practice.

Permanent alopecia can occur following treatment for pediatric malignant disease, especially cranial irradiation, resulting in identity and self-image problems. This late effect is usually addressed through external cosmesis and psychological adjustment. Surgical options are less commonly utilized. The experience of reconstructive procedures in patients at RLC NHS Trust, Alder Hey with alopecia is presented. Four patients had scalp tissue expansion and one had hair transplantation. The reconstructive options available are discussed as well as the potential opportunities and difficulties in this population. Post-radiotherapy alopecia can be successfully addressed by reconstructive surgery, and should be considered more often in this population.

Adolescent↗
PubMed2002

Improved initial yields in C-terminal sequence analysis by thiohydantoin chemistry using purified diphenylphosphoryl isothiocyanate: NMR evidence for a reaction intermediate in the coupling reaction.

A thiohydantoin method for C-terminal sequence analysis of proteins on Zitex membranes involves derivatization of the free alpha-carboxyl group with diphenylphosphoryl isothiocyanate (DPPITC) plus treatment with pyridine to form a peptidylthiohydantoin derivative, cleavage of the thiohydantoin (TH) amino acid from the protein with potassium trimethylsilanolate, and identification of the released TH-amino acid by online reversed-phase HPLC. This automated chemistry, which was adapted to the Hewlett-Packard G 1009A sequencer, has been shown to identify two or three cycles on a wide variety of proteins, but suffers from low initial yields and instability of the DPPITC reagent. We report here an improved method for synthesis and purification of DPPITC. With this procedure the DPPITC reagent is a clear liquid that is stable at room temperature under vacuum for more than 9 months or for more than 24 months as a 1.0M solution in benzene at -20 degrees C. Using the purified reagent we were able to more than double the initial yield (from 30.7 to 72.4%) of TH-amino acid from a test protein and substantially decrease sequencer background. Examination of the reaction between DPPITC and the carboxylate of model N-terminally protected dipeptides with 31P NMR provides spectroscopic evidence for a postulated intermediate formed between the DPPITC and the peptide carboxylate. The reaction intermediate provides new insight into the coupling mechanism.

Isothiocyanates↗