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J West

Publications and source records attributed to J West.

13 recordsLinked to original sources
PubMed1992

A prospective study examining the changes in factors that affect visual acuity following trabeculectomy.

Many patients report subjective changes in vision following trabeculectomy. In a prospective study of 16 eyes, we have tried to determine the causes of these visual changes. Ninety-four per cent of eyes showed a change in uncorrected Snellen acuity 1 week following surgery. This change was due to a myopic shift in refraction secondary to changes in the anterior chamber depth. A 1 mm change in anterior chamber depth results in approximately a 2 dioptre change in refractive sphere. Visual acuity starts to return to pre-operative levels by the third post-operative week, from which point no eyes showed a deterioration in corrected acuity of more than one line of Snellen. The vertical corneal radius of curvature is reduced in the early post-operative period and there is a with-the-rule change in corneal astigmatism. This resolves over longer follow-up and the possible causes of this are discussed. No changes were noted in corneal thickness and there was no evidence of macular oedema over the follow-up period. Patients should be warned of these possible visual changes pre-operatively as many will have normal acuity prior to surgery.

Aged↗
PubMed1977

Circulatory response to systemic infusion of norepinephrine in the pregnant ewe.

Seven pregnant ewes from 100 to 137 days of gestation were infused with systemic doses of norepinephrine and uterine arterial flow dose-response curves were determined. A constant infusion of norepinephrine at a mean rate of 0.24 mug per minute per kilogram led to a 39.3 per cent decrease in total uterine arterial blood flow as measured with isotope-labeled microspheres while systemic pressure was unaltered. At this dose the reduction in endometrial blood flow (--64 per cent) was significantly greater than that in either the myometrium (--45 per cent) or placental cotyledons (--31 per cent) (p less than 0.005). Significant decreases in blood flow to small bowel, skeletal muscle, vagina, cervix. Fallopian tubes, kidneys, spleen, pancreas, and mammary gland were documented. There were no significant increases in blood flow. This study demonstrates that during the period or pregnancy studied, the overwhelming response to norepinephrine is vasoconstriction and that the vascular beds of all the tissues of pregnant uterus are sensitive to the alpha-adrenergic effects of norepinephrine.

Animals↗
PubMed1975

Sialoadenosis produced by drug-treatment of hypertonicity. II. Experimental studies on the effects of guanethidine (Ismelin) on the submaxillary glands of the rat.

48 rats were treated with guanethidine (Ismelin) in order to study the side-effects on the submaxillary glands following application of a routinely used antihypertensive substance. In contrast to guanethidine-treated parotid glands, no retention of alpha-amylase was observed. The amylolytic activities of the glands are decreased both after treatment for 24 hrs and when a 3 week treatment had been followed by a 2 week recuperation period. This decrease of total amylase content runs parallel with alterations in the alpha-isoamylase patterns of the submaxillary glands. Furthermore, gland growth is inhibited by the guanethidine-mediated "pharmacological sympathectomy". We interpret these proteodyschylic changes of the submaxillary glands as a pharmacologically induced peripheral neurogenic sialoadenosis.

Amylases↗