Search PubMedSearch

Biomedical subjects

D J Bailey

Publications and source records attributed to D J Bailey.

6 recordsLinked to original sources

Local anesthesia in rhinoplasty: a new twist?

Twenty volunteers were asked to compare pain upon injection during septorhinoplasty using buffered versus unbuffered local anesthetics. The concentration of the buffer was one part sodium bicarbonate to five parts local. The surgeons performing the operation were asked to identify any difference in hemostasis or duration of anesthesia. Eighteen of twenty patients found the buffered anesthetic to be less painful and better tolerated. No difference in hemostasis or duration of action was noted between the buffered or unbuffered solution, however, faster onset of action was noted with the buffered solution. The addition of sodium bicarbonate as a buffering agent to the local anesthetics lidocaine and bupivacaine can significantly reduce pain upon injection. A solution of 5cc 2% lidocaine with 1:100,000 epinephrine, 5cc 0.25% bupivacaine with 1:200,000 epinephrine, and 2cc of 7.5% sodium bicarbonate mixed just prior to injection is a safe, effective, less painful local anesthetic with rapid onset of action and full efficacy.

Adult

Cation transport across the guinea-pig placenta perfused in situ.

1. The guinea-pig placenta perfused in situ via the umbilical circulation has been used to measure unidirectional fluxes of Na from mother to fetus, and in the reverse direction, with 24Na and 22Na. There was no significant difference between the two fluxes, each being 22 mumole.min-1. 2. Ouabain 10(-5) M in the perfusion fluid had no detectable effect on radioisotopic movements of Na in either direction. 3. Unidirectional fluxes of 42K in both directions were approximately equal at 1.7 mumole.min-1 mother fetus and 1.8 mumole.min-1 in the reverse direction, despite a K concentration of 3.4 mM on the maternal side and 5.0 mM on the fetal side of the placenta. 4. Extraction of 42K and 86Rb from the perfusion fluid was inhibited by 43% by 10(-5) M-ouabain in the fluid. This effect was largely due to a reduction of isotope uptake by the placental tissue. 5. The relative permeabilities of the placenta, mother to fetus, were Rb approximately K (3.2) greater than Na (1.0) greater than Li (0.55). 6. Under the experimental conditions, the electrical potential difference between perfusion fluid and maternal blood was 6 mV (fetus negative). It was shifted towards the positive by a low Na fluid. 7. The results suggest the presence of a dominant Na-K pump (active component towards mother) sited at the maternal-facing membrane of the syncytiotrophoblast together with a subsidiary pump oriented in the opposite direction and probably sited together with a subsidiary pump oriented in the opposite direction and probably sited at the fetal-facing membrane of the syncytiotrophoblast. 8. A high proportion of Na movement particularly towards the fetus is probably passive, occurring through water-filled spaces, whilst K movement is more dependent on active transport.

Animals

Estrogen potentiating activity of two spiro compounds having approximately similar molecular dimensions to stilbestrol.

Pharmacological investigation of members of a series of synthetic spiro derivatives with similar molecular dimensions to stilbestrol revealed that two compounds, spiro[cyclohexane-1,2'-tetralin]-1,4'-dione and spiro[cyclohexane-1,2'-indan]-1,4'-diol, exhibited a marked ability to potentiate stilbestrol at doses which had no intrinsic estrogenic activity. It is postulated that such compounds may be of use in reducing the side effects associated with estrogen therapy.

Animals

Nuclear accumulation of androgens in perfused rat accessory sex organs and testes.

The uptake of androgens into the nuclei of caput epididymis, ventral prostate, seminal vesicle and testis was studied by recirculating physiological and pharmacological concentrations of [3H]testosterone in an artificial medium through the lower half (hemicorpus) of castrated or hypophysectomized rats. The accumulation of dihydrotestosterone in accessory sex organ nuclei was saturable, inhibited by perfusion of excess testosterone or cyproterone acetate, and associated with binding to 3S salt-extractable molecules. In castrated preparations the mean saturation levels (pmol/mg DNA) were different in the three organs: seminal vesicle, 2.8; ventral prostate, 1.8; caput epididymis, 0.9. The saturation level was significantly lower in ventral prostate of hypophysectomized rats (1.2) treated with testosterone to regenerate the accessory sex organs. Testosterone was the major nuclear androgen in the testes of mature hypophysectomized preparations perfused with testosterone. Although there was a large amount of nonspecific accumulation, testosterone binding to 3S molecules was shown by sucrose gradient centrifugation. Binding of dihydrotestosterone to 3S molecules in testicular nuclei was also demonstrated. The ratio of dihydrotestosterone to testosterone was different in immature and mature testicular nuclei and was altered by treatments known to affect testicular 5 alpha-reductase activity. The results suggest that in rat accessory sex organs and immature testis the major active androgen is dihydrotestosterone, whereas in mature testis it is testosterone. The shift in the predominant nuclear androgen in the testis from dihydrotestosterone to testosterone is most simply explained by the maturational change in 5 alpha-reductase activity.

Androgens

Evaluation of methods for perfusing rat testes.

Organ perfusion methods offer a number of advantages in biologic studies but require full characterization before application. Two new methods for perfusing rat testes were characterized and compared with recirculating hemicorpus system. These preparations, selective and isolated testicular perfusion, are nonrecirculating and consequently, allow direct measurement of testosterone secretion. In both systems, testosterone production was a fuction of the dose of human chorionic gonadotropin in the perfusion medium up to 1000 mIU per ml which appeared to be inhibitory. The isolated testis method, in comparison with the selective, is more sensitive to human chorionic gonadotropin, requires less perfusion medium, maintains normal blood flow rates and water content, and is associated with no ischemia at commencement of perfusion. However, this system does not retain normal levels of ATP and GTP after 3 hr of perfusion. Whereas both procedures may be used for studies of testosterone secretion and androgen receptors, the inability to maintain testicular ATP and GTP levels indicates that present methods are not suitable for study of processes dependent upon high energy phosphate metabolism.

Adenosine Triphosphate