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Biomedical subjects

A C Kinn

Publications and source records attributed to A C Kinn.

At least 37 records · Page 2Linked to original sources
PubMed1993

Percutaneous extraction of upper urinary calculi under fluoroscopic control--still a valuable complement to ESWL.

Percutaneous extraction of 372 renal and proximal ureteral calculi was performed under fluoroscopic control in 202 consecutive patients. In 193 kidneys (90%) removal of stones was performed under fluoroscopic control only and in 10% initial ultrasonic disintegration was used. A completely stone free kidney was achieved in 74%. If successful outcome is defined as no stones or residual fragments less than 5 mm, the success rate was 91%. With a mean size of 10.3 mm 259 intact stones were extracted under fluoroscopic control. Open surgery was performed in 13 of 202 patients, in 10 of these cases due to unsuccessful removal of an impacted ureteral stone. Complications occurred in 16%, none of them were serious. Open intervention became necessary in 2 patients. Bleeding which required blood transfusion occurred once. Percutaneous renal stone extraction under fluoroscopy is safe and useful in selected patients when ESWL can be expected to produce less favourable results. The ability to perform this technique should therefore be well maintained.

Adolescent↗
PubMed1992

Receptor function studies in specimens from the proximal human urethra obtained by transurethral resection.

During transurethral resection (TUR) for prostatic hyperplasia, specimens were taken from the proximal urethra. Muscle strips thus obtained were mounted in an organ bath and muscle contraction was induced by adding increasing concentrations of noradrenaline (NA), methoxamine (alpha 1-agonist) and clonidine (alpha 2-agonist). NA and methoxamine induced a dose-dependent muscle contraction, but clonidine had no effect. The influence of prazosin (alpha 1-antagonist) and yohimbine (alpha 2-antagonist) on the NA-induced muscle contraction was also evaluated. Both antagonists had an inhibitory effect, which was much more potent with prazosin. The specimens taken during TUR were found to be suitable for in vitro receptor function studies. The alpha-adrenergic receptor function in the proximal human urethra was found to be mainly of the alpha-type.

Adrenergic alpha-Agonists↗
PubMed1992

Cost effectiveness of extracorporeal shock wave lithotripsy and percutaneous nephrolithotomy for medium-sized kidney stones. A randomised clinical trial.

To evaluate percutaneous nephrolithotomy (PNL) and extracorporeal shock wave lithotripsy (ESWL) for their clinical effects, their cost effectiveness, their complication rates, and the patients' experiences, 55 consecutive patients were randomised to have one or other operation between October 1986 and October 1988. Six patients were excluded, 21 were treated with PNL and 28 with ESWL as primary treatment. Mean hospital stay and length of treatment were longer for PNL than for ESWL. Since 1 July 1987 all patients having ESWL have been treated without anaesthesia (n = 15), whereas epidural anaesthesia was used for all PNL. Slightly more of the ESWL patients experienced some pain during treatment. Minor complications or pain were more common after ESWL during the first 10 days after discharge from hospital. If patients with stone fragments of 4 mm or less were regarded as having a successful outcome, the success rates after one year were 94% for PNL and 77% for ESWL. The overall total cost was lower for ESWL than for PNL, the cost per successfully treated patient being 2172 pounds for PNL and 1810 pounds for ESWL. Medium sized kidney stones (6-30 mm, or 2-3 stones of 20 mm or less) can be efficiently and cheaply treated by both PNL and ESWL, though the cost of ESWL is lower. Even if effects other than cost (such as complications and patients' experience) are borne in mind, ESWL was superior to PNL for this group of patients.

Cost-Benefit Analysis↗
PubMed1991

Effects of direct current on renal function. An experimental study in pigs.

Electric current from an external source was introduced between electrodes operatively placed into the ureters and positioned in the renal pelves of 13 pigs. Urinary excretion via the cathodic kidney showed a marked increase. The renal plasma flow and glomerular filtration rate diminished with increasing voltage, but no significant difference was found between the cathodic and the anodic kidney. The fractional sodium excretion by the cathodic kidney was 80% higher, indicating that the electric current mainly affected tubular function. A possible clinical application for electric fields in the kidneys is discussed.

Animals↗
PubMed1991

Electric modification of kidney function. The excretion of radiographic contrast media and adriamycin.

The body consists of systems of conductive pathways for ionic flow of current induced by metabolic or injury potentials among tissues and cells. In vivo electrophoresis in biologically closed electric circuits (BCEC) are coupled to the mechanical transports of blood and lymph. Connections also exist with conductive media such as cerebrospinal fluid, bile, and urine. Artificial induction of current was applied over the kidneys in order to study modification of kidney function. It is thought that studies of this kind will increase our understanding of kidney function from a new angle of view and possibly add new therapeutic possibilities. In anesthetized pigs, one kidney was made anodic (electropositive) and the other cathodic (electronegative). Current was applied between electrodes in each ureter. Intravascularly injected, electronegatively charged aminotrizoate and ioxaglate were excreted mainly by the anodic kidney. Nonionic iohexol was urographically excreted by both kidneys. Excretion of electropositively charged Adriamycin by the cathodic kidney was identified macroscopically and by chemical analysis. Functional effects on the kidneys can be induced electrophoretically without causing injury.

Animals↗
PubMed1991

Percutaneous nephrolithotomy--the birth of a new technique.

Extraction of renal calculi via a percutaneous track was for the first time practised at the Karolinska Hospital in 1973. After very strict indications in the beginning because of fear of uncontrollable bleeding, the method was found to be safe and the technique was spread all over the world. Now being to a large extent replaced by extracorporeal shock wave lithotripsy (ESWL), percutaneous nephrolithotomy (PNL) has still many applications e.g. alone in obstructed kidneys or together with ESWL in staghorn calculi.

History, 20th Century↗
PubMed1991

Vesicoureteral reflux in adults studied by computerized radionuclide cystography.

Direct radionuclide cystography in a computerized method as described by Willi and Treves was used in adults with recurrent pyelitis but without evidence of obstruction. Reflux was observed in 15 out of 38 patients. In patients with neurogenic bladder dysfunction or megaureters, reflux began early during the bladder filling and attained higher volumes than in those with uncomplicated pyelitis, who had minor reflux appearing mainly during voiding. Bladder capacity and detrusor compliance were lower in patients with reflux than in those without reflux. The low radiation exposure in radionuclide cystography permits observation of the urodynamic course of urinary reflux and correlation to the intravesical volume and pressure. The method is sensitive, and minor refluxed volumes can be detected. Radionuclide cystography can therefore be recommended for checking of surgical results and for follow-up of patients with neurogenic bladder dysfunction.

Adolescent↗
PubMed1990

Maximal electrical stimulation in the treatment of unstable detrusor and urge incontinence.

Ninety-one patients with unstable detrusor and urge incontinence were treated with maximal electrical stimulation. There were 17 dropouts. From the remaining 74 patients 51 were subjectively cured or significantly improved, this effect lasted for more than 6 weeks in 40. Objectively a significant decrease in frequency was found, also a significant increase in bladder volume. No effect on detrusor pressure at bladder contraction was noted.

Adult↗
PubMed1990

Desmopressin: a new principle for symptomatic treatment of urgency and incontinence in patients with multiple sclerosis.

Thirteen patients with advanced multiple sclerosis and urge urinary incontinence were treated with desmopressin--a synthetic analogue of antidiuretic hormone--in a double-blind cross-over study. The micturition frequency decreased significantly (p less than 0.05). Less leakage was considered valuable for daily life. Peroral medication was favourable in these patients with muscular dysfunction. Side-effects were few.

Administration, Oral↗
PubMed1989

Stop-flow measurement of detrusor contractility in bladder outflow obstruction.

Detrusor contractility was evaluated by measuring the increase in isometric pressure during a stop test in 25 men with benign prostatic hyperplasia. Before transurethral prostatic resection (TUR), a low pressure increase (delta P det iso) was associated with a large volume of residual urine. After TUR both the speed and the amplitude of isometric detrusor contractions during the stop test increased. A pre-operative low detrusor pressure increase was correlated with a great improvement in flow rate after TUR. The value of the stop-flow test was limited, however, since improvement in other urodynamic parameters could not be predicted.

Aged↗
PubMed1989

The effect of diclofenac sodium on renal function.

The effects of diclofenac sodium on the kidneys were studied during 4 1/2 hours in eight patients with normal renal function. Urinary output decreased within 10 min after the injection, and maximally by 80%. The renal plasma flow and the glomerular filtration rate initially diminished significantly, by 35%, but began to increase after only 2 hours. The dominant and persistent effect was reduction of free water clearance, with maximum fall from 5.9 to 0.08 ml/min after 2 1/2 hours. The long-lasting increased tubular reabsorption of water probably is important for the lowered intrapelvic pressure that is associated with good analgetic effect of diclofenac in ureteral colic.

Adult↗
PubMed1988

Biochemical characterization of prostaglandin 19-hydroxylase of seminal vesicles.

The microsomal fraction of homogenates of seminal vesicles of men and monkeys, Macaca fascicularis, were analyzed for prostaglandin (PG) 19-hydroxylase activity. The microsomes of the monkey seminal vesicles, supplemented with 1 mM NADPH, metabolized 0.2 mM PGE1 to 19-hydroxy-PGE1 at a mean rate of 0.26 nmol/min/mg of protein (with an apparent Km and an apparent Vmax of 40 microM and 0.30 nmol/min/mg of protein, respectively). The enzyme catalyzed the incorporation of atmospheric oxygen into the substrate. Substituting NADH for NADPH reduced the prostaglandin E1 19-hydroxylase activity to 40%. Carbon monoxide and proadifen (SKF 525A) inhibited the enzyme. Prostaglandin E2 (0.2 mM) was metabolized to 19-hydroxyprostaglandin E2 (0.2 nmol/min/mg of protein), but PGE1 was preferred as a substrate. Prostaglandin B1 was metabolized to 18-hydroxy-, 19-hydroxy-, and 20-hydroxyprostaglandin B1 at a combined rate of approximately 25% of prostaglandin E1. 19-Hydroxyprostaglandin B1 was the main product. The microsomes of human seminal vesicles metabolized 0.2 mM PGE2 to 19-hydroxy-PGE2 in the presence of 1 mM NADPH, while carbon monoxide inhibited this reaction. These results suggest that prostaglandin 19-hydroxylase of seminal vesicles might be a cytochrome P-450. The biosynthesis of 19-hydroxyprostaglandin E1 and 19-hydroxyprostaglandin E2 was also studied in vivo in man by analysis of the product/substrate ratios (i.e. 19-hydroxyprostaglandin E1/prostaglandin E1 and 19-hydroxyprostaglandin E2/prostaglandin E2) in a series of consecutive ejaculates, which were obtained during short intervals. There was a 10-fold interindividual difference in these ratios. Although the product/substrate ratios decreased, the 19-hydroxylation of E prostaglandins appeared to be efficient in vivo, which was in contrast to the rather slow biosynthesis in vitro.

Animals↗
PubMed1988

Estrogens and phenylpropanolamine in combination for stress urinary incontinence in postmenopausal women.

Thirty-six postmenopausal women with objectively verified stress incontinence were treated with oral estriol (Triovex, 2 mg x 1) and phenylpropanolamine (Kontexin, 50 mg x 2) alone and in combination. After an initial four-week single-blind period with phenylpropanolamine (PPA), either estriol or estriol and PPA were given randomly in four-week periods, in a crossover design. PPA and estriol in combination as well as PPA alone, raised the intraurethral pressure and significantly reduced the urinary loss by 35 per cent in a standardized physical strain test. In women with an initial low urethral pressure estriol also induced pressure increase. The leakage episodes and the assessed leakage amounts were significantly reduced by both estriol and PPA given separately as single treatment (28%) or when given as combined therapy (40%). Most of the women preferred the combined treatment to either drug alone. Additive but no synergistic effects are indicated.

Administration, Oral↗