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Biomedical subjects

G S Benson

Publications and source records attributed to G S Benson.

At least 19 recordsLinked to original sources

Autonomic innervation of the mammalian penis: a histochemical and physiological study.

The distribution of adrenergic and cholinergic nerves was studied in penile tissue from rat, rabbit, cat, monkey and man. Glyoxylic acid histofluorescence and acetylcholinesterase-positive fibers were found in all tissues examined, but histofluorescent, presumably adrenergic fibers predominated. In general, except in the rabbit, more nerve fibers of both types were found in the corpus cavernosum (CC) than in the corpus spongiosum/penile urethra (CS). The rabbit penis showed slightly more adrenergic fibers in the CC than in the CS and more cholinergic nerves in the CS than in the CC. The CC of the monkey demonstrated an alpha receptor mediated contractile response to norepinephrine (NE) stimulation and no response to acetylcholine (ACh) in an in vitro muscle bath.

Acetylcholinesterase

Transient blindness: unusual initial symptom of transurethral prostatic resection reaction.

Transient blindness was seen in 2 patients undergoing transurethral resection (TUR) of the prostate as the initial symptom of a severe TUR reaction. Cerebral edema of the occipital cortex is the most probable mechanism. Both fully recovered their vision when appropriately treated. Patients with visual disturbances during transurethral prostatectomy should be suspected of having a TUR reaction.

Aged

Gross hematuria associated with sickle cell trait and von Willebrand's disease.

A case of recurrent gross hematuria, sickle cell trait and von Willebrand's disease is reported. The gross hematuria abated promptly after the institution of cryoprecipitate therapy. The importance of considering von Willebrand's disease in the differential diagnosis in patients with sickle cell trait and hematuria is discussed.

Adolescent

Lack of evidence for adrenergic innervation of the external urethral sphincter.

Catecholamine histofluorescence studies of the external urethral sphincter in 11 normal dogs, 4 dogs treated with tranylcypromine and 4 humans have demonstrated that this striated muscle does not possess adrenergic innervation. This finding suggests that the sympathetic nervous system affects outlet resistance only through its influence on the smooth musculature of the bladder neck and urethra.

Animals

The reproducibility and interpretation of carbon dioxide cystometry.

The day-to-day and same-day variability of carbon dioxide cystometry was examined in a population of men. Considerable variability was observed in each parameter monitored. The implications of such variability, and the validity and significance of certain cystometric events are discussed.

Adult

Bladder muscle contractility. Comparative effects and mechanisms of action of atropine, propantheline, flavoxate, and imipramine.

The anticholinergic and antispasmodic activity of atropine, propantheline, imipramine, and flavoxate were judged by each drug's ability to inhibit bethanechol chloride and barium chloride-induced canine detrusor contractions. In this in vitro model, atropine and propantheline are pure anticholinergic agents. Imipramine significantly decreases both bethanechol and barium-induced contractions, while flavoxate only minimally inhibits the response to either stimulant.

Animals

Innervation of trigonal area of canine urinary bladder.

Adrenergic and cholinergic histochemical staining techniques and in vitro muscle strip responses to adrenergic and cholinergic stimulation and blockade have failed to demonstrate any neuromorphologic or neuropharmacologic differences between the musculature of the canine trigone and that of the underlying detrusor. There is no evidence to suggest that a functional potential could be attributed to the trigone separate from that of the related bladder base.

Acetylcholine

Management of neurogenic bladder dysfunction in the adult.

A review of the management of neurogenic bladder dysfunction in the adult is presented. The various modes of therapy are classified according to their effects on bladder contractility and outlet resistance, providing a logical framework for discussion.

Autonomic Nerve Block

Adrenergic innervation and stimulation of canine urethra.

Sympathetic nervous innervation of the canine urethra was studied using catecholamine histofluorescent straining and the in vitro muscle bath. Morphologically, adrenergic nerves were found terminating on the urethral smooth muscle. Pharmacologically, urethral strips responded like muscle strips from the bladder base to adrenergic stimulation. This evidence supports the concept that the sympathetic nervous system supplies and modulates the function of the smooth muscle stimulation of the rich periurethral vasculature nerve supply.

Animals

Effect of levodopa on urinary bladder.

Levodopa therapy enhanced the ability of the bladder to store urine in two parkinsonian patients. In vitro canine muscle bath studies with the two major metabolites of levodopa, dopamine and norepinephrine, indicate that the effects of the drug on the peripheral sympathetic nervous system may play a major role in the improvement of urinary symptoms observed with levodopa therapy.

Aged

Oral methylene blue and the dissolution of renal calculi.

Oral methylene blue therapy was not effective in dissolving non-obstructive renal calculi in 26 patients but it may prevent new stone formation in patients with metabolically active urolithiasis. The use of methylene blue therapy in combination with other regimens having different mechanisms of stone inhibition is recommended to further improve results.

Administration, Oral

Adrenergic and cholinergic stimulation and blockade of the human bladder base.

The response of muscle strips from the human anterior and posterior bladder base to autonomic stimulation and blockade was studied. The human bladder base, like that of the dog, possesses an abundance of cholinergic and alpha-adrenergic receptor sites. Neuropharmacologically, the musculature of the anterior base is similar to that of the posterior base (trigone plus detrusor musculature).

Acetylcholine