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Biomedical subjects

J R Hale

Publications and source records attributed to J R Hale.

12 recordsLinked to original sources
PubMed1983

Magnetic microspheres as drug carriers: factors influencing localization at different anatomical sites in rats.

Factors of practical expediency influencing magnetic fixation of circulating microspheres, known to be capable of carrying therapeutically effective drugs, were studied in three different anatomic sites in rats: the tail, the hind leg, and the head (including both soft tissues and brain). Specific localization of magnetic microspheres was achieved at these three sites, but only with varying degrees of success. Specific targeting of the microspheres within brain tissue could not be accomplished. Factors influencing and tending to restrict specific retention of circulating microspheres by an external magnetic force include: complex vasculature networks, subsurface depth, and tissue-vascular barriers. Even with magnets producing high magnetic field gradients, effective localization of microspheres would appear to be restricted to tissues relatively close to body surfaces.

Animals↗
PubMed1978

A new magnetic technique for the treatment of giant retinal tears.

Using surgical techniques similar to those for closed vitreous surgery, we introduced a small magnetic sphere into the intraocular cavity of experimental animals. The sphere was subsequently maneuvered gently over the retina to unfold and reposition it with a small external permanent magnet probe. We used 68 enucleated canine eyes; eight eyes were operated in vivo and then examined microscopically. Retinal damage was caused by friction and excessive pressure when we used external magnets that were too strong or spheres that were too large. When small intraocular magnetic spheres coated with silicone or teflon or encased in a hollow oversize epoxy sphere were used the damage to the retina was minimal, or absent. We suggest using this same technique to treat retinal tumors through the introduction of radioactive material or antitumoral drugs. The intraocular magnetic sphere of this type would be left inside the eye in contact with the lesion for an extended period (seven days to three months) by suturing a small magnet to the sclera over the lesion.

Animals↗
PubMed1976

High-pouch imperforate anus treated by electromagnetic bougienage and subsequent perineal repair.

Four male infants with imperforate anus were treated by electromagnetic bougienage and subsequent perineal anoplasty with division of rectourethral fistula. Each had high-pouch imperforate anus of the supralevator type, with rectourethral fishtula at or above the level of the membranous urethra. Perineal anoplasty was accomplished in all four, with division of the rectourethral fistula, avoiding the need to do a sacral-abdominal-perineal procedure, as had been customary previously in similar cases.

Anal Canal↗
PubMed1975

Electromagnetic bougienage to lengthen esophageal segments in congenital esophageal atresia.

Some cases of esophageal atresia, either with or without tracheoesophageal fistula, are not suited for primary anastomosis. To avert the need for colon interposition in two such infants, intermittent electromagnetic force was used to pull together "bullets" placed in the esophageal ends. This method elongated and enlarged the esophageal segments enough to accomplish their anastomosis later. This approach appears feasible to use for infants whose esophageal malformation does not permit primary repair. It may also be applicable to cases of imperforate anus with a hight pouch.

Dilatation↗