A new antisplash irrigation system.
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Equipment Design↗
Biomedical subjects
Joy Odili
Publications and source records attributed to Joy Odili.
Effect of imidazole on the solubility of a his-tagged antibody fragment.
A number of studies have demonstrated the limited solubility of single-chain Fv antibody fragments and its improvement by genetic engineering. This limits the stability of recombinant protein upon storage and the efficiency of chemical modification. The RAFT3 scFv used in the present work is specific for melanoma-associated proteoglycan and an attractive candidate for clinical radioimaging studies because of its unusual radiolabelling properties. However, when expressed with a c-terminal his(6) IMAC purification tag, the recombinant protein starts to precipitate after column elution and dialysis against PBS and reaches a concentration of soluble protein of approximately 150 microg/mL within a few days upon storage at 4 degrees C. We tested several commonly used buffer modifications (addition of detergents, high salt, amino acids) to improve the solubility and stability of the protein but without any major improvement. However, we found that, when the final dialysis step was omitted and the protein left in IMAC column elution buffer (PBS containing imidazole), it remained soluble. Furthermore, several months old and precipitated protein could be redissolved in this buffer without loss of antigen binding. This observation and the largely pH-independent nature of protein solubility suggest that neither salt bridges formed by the his(6) tail nor cross-linking of his(6) tails mediated by metal ions leached from the column during elution are responsible for the limited solubility of the protein in the absence of imidazole. The presence of imidazole did not interfere with radiolabelling and in vivo tumor targeting in a mouse model. The solubilizing and stabilizing effect of imidazole could be of use for his(6) tagged and poorly soluble recombinant proteins other than scFvs.
Animals↗
Laser depilation of the natal cleft--an aid to healing the pilonidal sinus.
BACKGROUND: Pilonidal disease is common. Excessive hair growth in the natal cleft is thought to be a factor in initiating these sinuses. It is chronic and intermittent in nature and treatment can be difficult. Hair removal by shaving or use of creams is often advised as a compliment to surgical treatments. However, access to the natal cleft can be difficult. Laser removal of hair in the natal cleft is considered as an aid to healing the pilonidal sinus. PATIENTS AND METHODS: Over a 5-year period, 14 patients with recurrent pilonidal disease were treated in our unit with laser depilation. They were all contacted by postal questionnaire, and those with ongoing disease were asked to return to the clinic for evaluation and possible further treatment. RESULTS: All patients returned the postal questionnaire. Of the 14 patients, 4 had on-going disease and received further depilation with the Alexandrite laser. All are now healed with no reported complications. All patients found the procedure painful and received local anaesthetic. CONCLUSIONS: Laser depilation in the natal cleft is by no means a cure for pilonidal disease. Removal of hair by this method represents an alternative and effective method of hair removal and, although long lasting, is only temporary. However, it allows the sinuses to heal rapidly. It is relatively safe, and simple to teach, with few complications. It should thus be considered as an aid to healing the problem pilonidal sinus.
Adolescent↗