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Biomedical subjects

C C Carson

Publications and source records attributed to C C Carson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Penile prosthesis implantation surgery: a statewide population based analysis of 2354 patients.

AIMS OF THE STUDY: Minimally invasive therapy for erectile dysfunction (ED) has changed the frequency of penile prosthesis surgery. The purpose of this study is to describe the changes in frequency, hospital stay, hospital charges and penile prosthesis type in North Carolina. MATERIALS AND METHODS: The data source was a statewide hospital discharge database which includes data on hospitalized patients for all 151 hospitals in North Carolina. RESULTS: From 1988-1993, 2354 patients underwent implantation of penile prostheses. The total number of penile prostheses implanted has declined over this six year period. Similarly, hospital stay has declined from an average of 4.03-2.96 d with a 46.6% decrease in total hospital days. Despite this change in hospital stay, hospital charges rose significantly from an average of $7252.48 to $12,842.18 driving total charges from $2973,516.80 to $3,826,969.60 (1993) representing a 28.7% increase. CONCLUSIONS: Minimally invasive therapy and changes in reimbursement have had a major impact on the number of patients undergoing penile prosthesis implantation for ED. This downward trend may continue as more treatment options develop from the marked increase in research in this field. However, this may result in an increase of patients seeking treatment overall.

Erectile Dysfunction↗
PubMed1998

Quantifying risk of penile prosthesis infection with elevated glycosylated hemoglobin.

PURPOSE: Elevation of glycosylated hemoglobin above levels of 11.5 mg.% has been considered a contraindication to penile prosthesis implantation in diabetic patients. We determine the predictive value of glycosylated hemoglobin A1C in penile prosthesis infections in diabetic and nondiabetic patients to confirm or deny this prevalent opinion. MATERIALS AND METHODS: We conducted a 2-year prospective study of 389 patients, including 114 diabetics, who underwent 3-piece penile prosthesis implantation. All patients had similar preoperative preparation without regard to diabetic status, control or glycosylated hemoglobin A1C level. Risk of infection was statistically analyzed for diabetics versus nondiabetics, glycosylated hemoglobin A1C values above and below 11.5 mg.%, insulin dependent versus oral medication diabetics, and fasting blood sugars above and below 180 mg.%. RESULTS: Prosthesis infections developed in 10 diabetics (8.7%) and 11 nondiabetics (4.0%). No increased infection rate was observed in diabetics with high fasting sugars or diabetics on insulin. There was no statistically significant increased infection risk with increased levels of glycosylated hemoglobin A1C among all patients or among only the diabetics. In fact, there was no meaningful difference in the median or mean level of glycosylated hemoglobin A1C in the infected and noninfected patients regardless of diabetes. CONCLUSIONS: Use of glycosylated hemoglobin A1C values to identify and exclude surgical candidates with increased risk of infections is not proved by this study. Elevation of fasting sugar or insulin dependence also does not increase risk of infection in diabetics undergoing prosthesis implantation.

Diabetes Complications↗
PubMed1998

A comparative study of the Abrams-Griffiths nomogram and the linear passive urethral resistance relation to determine bladder outlet obstruction.

PURPOSE: The Abrams-Griffiths and linear passive urethral relationship (PURR) nomograms are commonly used to diagnose bladder outlet obstruction. To the best of our knowledge there are no clinical studies comparing these 2 evaluations to determine if they similarly predict the findings of bladder outlet obstruction. MATERIALS AND METHODS: From October 1994 through December 1996 multichannel urodynamic studies were performed in 72 men with lower urinary tract symptoms. The data from each urodynamic study were plotted on the Abrams-Griffiths and PURR nomograms. RESULTS: Using the Abrams-Griffiths nomogram 23 patients (46%) were unobstructed, 15 (21%) were equivocal for obstruction and 24 patients (33%) were obstructed. When the linear PURR nomogram was applied to the pressure-flow data in each group all unobstructed cases were categorized into grade 0 or 1 (no obstruction), equivocal into grade 2 (mild obstruction) and obstructed into grades 3 through 6 (moderate to severe obstruction). CONCLUSIONS: The Abrams-Griffiths and linear PURR nomograms are helpful and comparable clinical tools to assess lower urinary tract symptoms in men. The linear PURR nomogram not only detects the presence of bladder outlet obstruction but grades its severity, which may be helpful to monitor treatment.

Aged↗
PubMed1998

Acucise endopyelotomy: a successful therapeutic intervention in the treatment of ureteropelvic junction obstruction.

Ureteropelvic junction obstruction is a well-recognized cause of pain and eventual renal failure. This condition may be congenital or it can develop secondary to renal calculi, infection, and instrumentation. Surgical intervention is the definitive therapy, and a number of surgical options are available to treat ureteropelvic junction obstruction. We describe an approach using the Acucise cutting balloon to perform retrograde endopyelotomy. In 12 patients making up 13 renal units, our success rate was 92.3%, at a mean follow-up of 8.4 months (range 2 to 21 months). Complications were minimal. Based on our experience, Acucise endopyelotomy is a successful therapeutic intervention in treating ureteropelvic junction obstruction.

Adolescent↗
PubMed1997

Peyronie's disease is associated with Paget's disease of bone.

Peyronie's disease is an idiopathic disorder in which an inflammatory fibrosis occurs in the tunica albuginea of the corpora cavernosa which causes the erect penis to become deformed. Peyronie's disease has a prevalence of 1% in men over age 50 years. Paget's disease of bone is a chronic skeletal disease with areas of increased bone turnover leading to pain, deformity, and in some cases arthritis. Because of a high rate of Peyronie's disease in subjects in a Paget's disease industry-sponsored drug trial, we asked whether there was an association between Peyronie's disease and Paget's disease of bone. We evaluated 61 men with Paget's disease attending our clinic for metabolic bone disease in a tertiary referral hospital, reviewed hospital records of all men discharged from our three hospitals with the diagnosis of Peyronie's disease, and mailed a validated questionnaire about shape of the erect penis to 1500 male members of the Paget Foundation. In the clinic population of men with Paget's disease of bone, 51 of 61 (83.6%) reported having normal erections; 10 patients (16.4%) were impotent. Sixteen of the 51 men (31.4%) had developed a bend or deformity in their erect penis which was confirmed by a urologist's examination to be Peyronie's disease. When the men with Paget's disease with and without Peyronie's disease were compared, there was no difference in their ages, years with Paget's disease, or serum alkaline phosphatase level. Upon medical record review, 1 patient of 262 (0.4%) with Peyronie's disease was found to have Paget's disease of bone. The men with Paget's disease returned their questionnaires for a response rate of 44.8% and reported Peyronie's disease with a prevalence of 14.5%. We suggest that Peyronie's disease is associated with Paget's disease of bone. Furthermore, we suggest that Peyronie's disease may be a previously unrecognized complication of Paget's disease of bone.

Aged↗
PubMed1997

Potassium para-aminobenzoate for the treatment of Peyronie's disease: is it effective?

The medical treatment of Peyronie's disease remains controversial. Oral and injectable medications have been used with little documented disease specific effectiveness. Potassium para-aminobenzoate (POTABA) has long been suggested as a treatment for the plaque, curvature, and pain produced by chronic Peyronie's disease. We report a retrospective review of 32 patients treated for at least 3 months with 12 g of POTABA powder daily and followed for 8 to 24 months. Symptom resolution demonstrated improvement in penile discomfort in 8 of 18 patients, decreased plaque size in 18 of 32 patients, and improvement in penile angulation in 18 of 31 patients. Complete resolution of angulation was reported in 8 of 31 patients. While this review was retrospective and uncontrolled, it does suggest a place for POTABA in the treatment of Peyronie's disease. In order to confirm these findings and to control for the natural history of spontaneous resolution of Peyronie's disease symptomatology, a prospective, double-blind, multicenter, well-controlled study with objective criteria should be established.

4-Aminobenzoic Acid↗
PubMed1996

Doppler sonography in the evaluation of corporovenous competence after penile vein ligation surgery.

Doppler ultrasonographic findings in patients after penile vein ligation surgery are described and compared to the results of cavernosometry and cavernosography. Peak systolic and end diastolic velocities were recorded for both cavernosal arteries at 5 min intervals after papaverine injection for a total of 30 min. Peak end diastolic flow rates were compared with cavernosometric and cavernosographic results at 0-10 min, 11-20 min, and 21-30 min. Cavernosography identified venous leakage in nine patients. The end diastolic velocities were greater than the 5 cm/s threshold level generally considered to be indicative of venous leakage in nine of the nine patients (100%) at 0-10 min, in eight of the nine (89%) at 11-20 min, and in nine of the nine (100%) at 21-30 min. Although peak end diastolic velocities at or near the 5 cm/s threshold could be found in patients both with and without recurrent venous leakage in the initial 10 min of the studies, only patients with recurrent venous leakage had diastolic velocities that exceeded the 5 cm/s level when measured 10 min or more after injection. Measurement of end diastolic velocities between 21 and 30 min after injection seemed to discriminate most effectively the patients with recurrent venous leakage from those without leakage in the postoperative population.

Adult↗
PubMed1995

Azidotetrakis(trimethylphosphine)nickel(II) tetrafluoroborate.

The title complex, [Ni(N3)(C3H9P)4]BF4, is a nearly perfect trigonal bipyramid with the azide group at an apical position. The metal-azide bond angle, Ni1--N1--N2, of 138.6(5) degrees is the largest observed for a terminal azide ligand.

Crystallography, X-Ray↗
PubMed1995

Characterization and function of histamine receptors in corpus cavernosum.

Widespread clinical use of H2 antagonists for peptic ulcer disease has been associated with reports of impotence. Histamine is a vasoactive amine which is endogenously produced in many organs including the penis. To date, 3 histamine receptor subtypes (H1, H2 and H3) have been identified. However, the role and function of histamine in the corpus cavernosal physiology are poorly understood. This study evaluates the in vitro functional characteristics of the 3 histamine receptor subtypes in the isolated corpus cavernosal strips from New Zealand White rabbits. The isometric responses to histamine and specific histamine receptor subtype agonists were assessed, following cyclooxygenase (indomethacin, 10(-5) M.), adrenergic (guanethidine, 5 x 10(-6) M.) and cholinergic (atropine, 5 x 10(-6) M.) blockade, at resting tension and after submaximal precontraction with norepinephrine (NE, 2 x 10(-5) M.). Histamine (10(-8) M. to 10(-3) M.) produced concentration-dependent contraction from basal and precontracted states and did not relax precontracted tissue. The H1 agonist, 2-(2-thiazolyl)ethylamine (10(-8) M. to 10(-3) M.), produced a contractile response from both basal and precontracted states, while the corporal tissue did not respond to either dimaprit, an H2 agonist (10(-8) M. to 10(-5) M.) or R(-)-alpha-methyl-histamine, an H3 agonist (10(-8) M. to 10(-5) M.). The response to histamine was progressively attenuated by an H1 antagonist (mepyramine; 10(-8) M. to 10(-5) M.), while neither an H2 antagonist (cimetidine; 10(-4)M.) nor an H3 antagonist (thioperamide; 10(-4)M.) had any inhibitory effects. H1 antagonism enhanced relaxation induced by electrical field stimulation (neurally mediated). Such relaxation increased after preincubation with 10(-6) M. or greater of mepyramine (p < 0.05). This study suggests that the principal histamine receptor subtype that mediates smooth muscle cell contraction in the corpus cavernosum is the H1 subtype. Since histamine H1 receptor antagonism increased NANC neurally mediated corporal relaxation, it possesses potential as an intracavernosal pharmacotherapeutic agent for the treatment of erectile dysfunction. This study, therefore, strongly indicates that H2 receptor antagonists are unlikely to have direct effects on penile erection.

Acetylcholine↗
PubMed1995

Modulation of vasoactive intestinal polypeptide (VIP)-mediated relaxation by nitric oxide and prostanoids in the rabbit corpus cavernosum.

The polypeptide VIP has been proposed as an inhibitory nonadrenergic, noncholinergic (NANC) neurotransmitter involved in the relaxation of cavernosal smooth muscle during erection. However, the specific mechanism(s) by which VIP exerts its effect is unknown. To determine whether VIP is involved in NANC-mediated cavernosal relaxation, strips of corpus cavernosum from New Zealand White rabbits were hung in tissue baths; atropine and guanethidine were added to block cholinergic and adrenergic neurotransmission, respectively. The tissue was then submaximally precontracted with norepinephrine (NE) and relaxed by electrical field stimulation (EFS; 10 V square waves, 0.5 msec. duration, 10 second trains at 5, 15 and 40 Hz) before and after preincubation with the VIP antagonist, VIP 10-28. To evaluate the role of nitric oxide (NO) and prostaglandins on the relaxant effect of VIP in the corpus cavernosum, the strips were contracted with NE and subsequently relaxed with cumulative doses of VIP (10(-10) to 10(-6) M.). After VIP dose-response curves were obtained, the strips were preincubated with N omega-nitro-L-arginine (NOARG, an inhibitor of nitric oxide synthase, 10(-4) M.) and the VIP dose-response curve was repeated. Indomethacin (10(-5) M.) was added to one-half of the NOARG treated strips to inhibit prostaglandin synthesis. VIP 10-28 inhibited EFS-induced relaxation (p < 0.05) and produced dose-dependent relaxation, which was inhibited by NOARG (p < 0.05). In contrast, the VIP-induced relaxation was more pronounced in the presence of indomethacin (p < 0.05). Moreover, indomethacin substantially reversed the NOARG inhibition of VIP relaxation (p < 0.05). These results suggest that VIP is a mediator of NANC cavernosal relaxation and that NO synthesis is involved in VIP-induced NANC relaxation in the corpus cavernosum. In addition, the presence of vasoconstrictive prostanoids modulates this VIP-mediated NANC relaxation. Therefore, VIP appears to contribute to NANC neurally mediated cavernosal relaxation, and its mechanisms of relaxation are dependent on prostanoid and involve the generation of NO.

Animals↗
PubMed1994

Selection of a subset of mRNAs from combinatorial 3' untranslated region libraries using neuronal RNA-binding protein Hel-N1.

Hel-N1, a human RNA-binding protein, shares significant homology with Drosophila protein ELAV, which is essential for fly neuronal development. Hel-N1 has been shown to bind in vitro to 3' untranslated regions of mRNAs encoding c-myc, c-fos, granulocyte/macrophage colony-stimulating factor, and transcriptional repressor, Id. We report that Hel-N1 and a related form, Hel-N2, are expressed in human medulloblastoma cells, but their ratio differs significantly from that in adult brain and fetal brain. Selection of RNA targets from randomized combinatorial libraries yielded (A+U)-rich consensus sequences for both Hel-N1 and Hel-N2. As a means to identify cellular RNA targets for these proteins, we devised combinatorial shape libraries representing naturally derived 3' untranslated regions and were able to select a structurally related subset of transcripts that bound to Hel-N1. Approximately 10% of the proteins encoded by these subset mRNAs were identifiable in the data bases and most are implicated in cell growth regulation. This approach provides a means to gain access to novel genes expressed in various cell types by partitioning mRNAs containing common sequence elements using RNA-binding proteins.

Base Sequence↗
PubMed1994

Lack of effect of carbon monoxide inhibitor on relaxation induced by electrical field stimulation in corpus cavernosum.

Carbon monoxide has been proposed as a possible neurotransmitter because of its ability to bind to the iron atom of the heme of guanylyl cyclase, which is similar to that of nitric oxide. To determine whether carbon monoxide exerts an effect on the penis, strips of rabbit corpus cavernosum were mounted in an organ bath for isometric tension studies and the effect of zinc deuteroporphyrin, an inhibitor of heme oxygenase which metabolizes hemoprotein and releases carbon monoxide, on relaxation induced by electrical field stimulation (neurally mediated) was determined. Also observed was relaxation induced by electrical field stimulation after incubation with atropine and guanethidine to isolate nonadrenergic noncholinergic neurotransmission. Zinc deuteroporphyrin (10(-6) M, 10(-5) M, 10(-4) M and 3 x 10(-4) M) did not affect relaxation induced by electrical field stimulation in the absence or presence of guanethidine and atropine. Therefore, it appears that carbon monoxide does not contribute to neurally mediated relaxation of the rabbit corpus cavernosum.

Animals↗
PubMed1994

Primary adenocarcinoma of the penis.

To our knowledge we report the first case of primary adenocarcinoma of the penis. After extensive evaluation to rule out metastatic disease from other sources, partial penectomy for primary adenocarcinoma of the penis was performed. Select histological stains of the tumor failed to reveal an extra penile origin.

Adenocarcinoma↗
PubMed1994

Investigation of vascular changes following penile vein ligation.

In an effort to characterize the changes in penile vasculature that occur following penile vein ligation, we performed pharmaco-cavernosometry and pharmaco-cavernosography on 20 patients after penile vein ligation for comparison with preoperative studies. Three patients with return of erectile function underwent repeat study: 2 were completely normal and 1 had a mild leak from the deep dorsal vein. The remaining 17 patients had continued complaints of erectile impairment. Of these studies 4 showed no evidence of venous leakage, 11 identified a new site of leakage (7 corporo-spongiosal shunts, 2 crural veins and 2 with multiple sites of involvement) and 1 revealed persistent leak through the proximal stump of the resected deep dorsal vein, while 1 patient had an iodine allergy and underwent pharmaco-cavernosometry only. A repeat study in the latter patient showed flow volumes consistent with continued venous leakage. In summary, penile vein ligation appears to be effective at correcting venous leakage noted on cavernosography. However, new sites of leakage frequently appear postoperatively. A corporo-spongiosal shunt was the most frequent site of recurrent venous leakage. A surprisingly high percentage of patients with continued complaints of erectile dysfunction following penile vein ligation demonstrate no venous leakage on subsequent pharmaco-cavernosography.

Erectile Dysfunction↗
PubMed1994

Experimental hypercholesterolemia in rabbits induces cavernosal atherosclerosis with endothelial and smooth muscle cell dysfunction.

Hypercholesterolemia and other vascular risk factors for atherosclerosis are commonly associated with impotence. To characterize cavernosal smooth muscle reactivity in hypercholesterolemia, we performed isometric tension studies (with norepinephrine, acetylcholine, papaverine and electrical field stimulation) on isolated strips of corpus cavernosum from rabbits fed a 1% cholesterol diet. To assess the impact of cholesterol reduction, a group of rabbits was fed a cholesterol diet for 4 weeks and was then returned to a normal diet for 4 weeks before testing. Potential structure-function relationships were delineated by ultrastructural evaluation with transmission electron microscopy (TEM). All forms of cavernosal relaxation, including papaverine relaxation, were impaired with hypercholesterolemia, and norepinephrine contraction was augmented. In addition, ultrastructural evidence of an early atherosclerotic process in the cavernosal sinusoids was detected. Importantly, reduction of elevated serum cholesterol normalized cavernosal relaxation, including that of papaverine, and decreased the sensitivity to norepinephrine, thereby suggesting that cavernosal smooth muscle dysfunction in hypercholesterolemia is reversible.

Animals↗