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Biomedical subjects

C L Parsons

Publications and source records attributed to C L Parsons.

At least 73 records · Page 4Linked to original sources
PubMed1990

Preliminary results of a phase I/II study of sodium pentosanpolysulfate in the treatment of chronic radiation-induced proctitis.

This is a report of a phase I/II study of 13 patients treated with sodium pentosanpolysulfate (PPS) for chronic radiation-induced proctitis. A complete response was obtained in 82%, a partial response occurred in 9%, and 9% failed to respond to therapy. No significant toxicity was observed. It is concluded that PPS is an effective treatment for chronic radiation-induced proctitis and a phase III randomized, double-blind study of PPS versus placebo is planned.

Adult↗
PubMed1990

Bladder surface glycosaminoglycans is a human epithelial permeability barrier.

Transitional epithelium of the bladder has been known to be impermeable. The data reported herein suggest the principal barrier to permeability may be glycosaminoglycans (GAG) of the surface of the bladder. We examined the ability of surface GAG to prevent a small molecule, urea, from moving across the epithelium in humans. It appears that GAG provide a physical barrier which prevents small molecules from reaching the underlying tight junctions and cell membranes and, hence, are a major permeability barrier. Normal volunteers (27) had 100 milliliters of a 200 grams per liter urea solution placed into their bladders for 45 minutes. Net flow of urea from the bladder lumen was 5.1 per cent. Volunteers who were capable of completing the study (19) had protamine sulfate (5 milligrams per milliliter) instilled in the bladder for 15 minutes, then removed and a second urea study done. Urea loss was significantly higher at 22 per cent (p less than 0.02). A solution of heparin (2,000 units per milliliter) was instilled for 15 minutes followed by a third urea study and urea loss was reversed to 9 per cent. All volunteers experienced significant urinary urgency and discomfort after protamine treatment which were reduced by heparin.

Administration, Intravesical↗
PubMed1989

Fibronectin levels in male ejaculate and evidence for its role in unexplained infertility.

Vasovasostomy has become a popular and highly successful method of restoring fertility to those who have undergone a vasectomy. However, there is a high correlation between vasostomy and antisperm antibody production leading to spontaneous sperm agglutination and immobilization. There is still considerable disagreement on whether antibodies are the primary causative agent. Our study provides evidence that fibronectin, a ubiquitous glycoprotein whose major function is cell-to-cell adhesion, could be a "subfertility" factor and contribute to male "unexplained infertility." Semen from control, random, and vasovasostomy populations was studied using a sophisticated enzyme-linked immunosorbent assay (ELISA). The results show that fibronectin is significantly present in all groups. The mean concentrations (micrograms/mL) were 753.9 for control, 566.4 for random, followed by significantly higher 1267.3 for the vasovasostomy group (p less than 0.05). The spermatozoa were assayed for bound fibronectin by flow cytometry. The mean percentage of cells bound after background subtract was 29.7 for control and 48.2 for the vasovasostomy group; the difference was significant (p less than 0.05). We conclude that fibronectin is present in semen and bound to sperm cells in great concentrations for individuals having undergone surgical insult and may contribute to male infertility particularly by sperm agglutination.

Adult↗
PubMed1989

Peyronie's disease: surgical experience and presentation of a proximal approach.

A total of 29 patients underwent 32 operations for correction of penile curvature. Of these patients 22 underwent placement of a semirigid prosthesis and 94 per cent of those available for followup were able to resume coitus. Of the 8 patients who underwent operative correction of penile curvature and who maintained potency only 3 (38 per cent) were able to resume intercourse. Vascular compromise and/or skin slough after degloving of the penile skin was noted in 3 patients. A proximal approach to penile reconstruction is presented.

Adult↗
PubMed1988

Urethral pressure profilometry in Scott artificial urinary sphincter.

The Scott sphincter models AS 791 and AS 800 were implanted in 22 men with urinary incontinence. Urethral pressure profilometry was used intraoperatively and postoperatively to measure the urethral closure pressure (UCP) and to improve the rate of continence and reduce the risk of erosion. Success was achieved in 20 of 24 patients. The utility of urethral profilometry in these cases is described.

Humans↗
PubMed1988

Reversible inactivation of bladder surface glycosaminoglycan antibacterial activity by protamine sulfate.

Prior studies in our laboratory have shown that the bladder surface is lined with glycosaminoglycans which appear to be an important antibacterial defense mechanism that operates by resisting bacterial adherence and infection. The present study further implicates bladder surface glycosaminoglycans as the key antiadherent factor and also suggests a potential model for diseases (such as urinary tract infections) whereby the antiadherent surface of the bladder is inactivated biochemically. Protamine sulfate treatment of bladder tissue was found to significantly increase bacterial adherence to the urinary bladder by approximately 2.3-fold. This effect was reversed by a second treatment of the bladder with pentosanpolysulfate (a polysaccharide known to duplicate the surface antiadherent effect). Protamine sulfate had no effect on bacterial viability or bacterial adherence when bacteria were pretreated with it.

Animals↗
PubMed1988

Protocol for treatment of typical urinary tract infection: criteria for antimicrobial selection.

Criteria for selecting an appropriate drug for treatment of urinary tract infection are based on therapeutic goals. A major criterion is to choose an antimicrobial that will not affect the patient's fecal and vaginal flora. Low cost is another important criterion. It is unnecessary to select an expensive antimicrobial when highly effective agents are available at low cost. High urinary concentration is the third goal of therapy and a major criterion for selecting an appropriate drug. To apply these selection criteria in clinical practice, use a criteria-based classification. Choose the agent highest on the following lists for which the patient shows no sensitivity: Class I, nitrofurantoin macrocrystals and penicillin VK; Class II, carbenicillin; Class III, amoxicillin; Class IV, trimethoprim-sulfamethoxazole and cephalosporins; Class V, ampicillin, tetracycline, norfloxacin.

Bacteria↗
PubMed1988

Overview. New standards for UTI--1988.

Lower urinary tract infection is a significant problem in 20 percent of the female population in the United States. An improved standard of care is now possible through new understanding of pathogenesis, evaluation, and cost-effective management. Urologists are called on to establish standard protocols for practical diagnosis and treatment of uncomplicated urinary tract infection, thereby establishing a common language among physicians and patients. An appreciation of host defense mechanisms, particularly the antiadherence role of glycosaminoglycan (GAG) in the bladder mucin, reinforces clinical recognition of the bladder as the target organ for bacterial attack associated with urinary tract infection.

Adult↗
PubMed1987

Inactivation of antiadherence effect of bladder surface glycosaminoglycans as possible mechanism for carcinogenesis.

We have shown that the urinary bladder secretes and binds to its surface a glycosaminoglycan layer whose nonspecific antiadherence effect protects the bladder from infection and perhaps from stone formation. If bladder cancer is caused by agents present in the urine, as is widely believed, this mechanism may also protect against carcinogenesis. We performed the current study to determine whether suspected carcinogens or cocarcinogens in the urine gain access to the transitional cells by impairing or inactivating the surface antiadherence effect. Using an in vivo method to quantitate bacterial adherence to the rabbit bladder, we compared adherence in control and glycosaminoglycan-deficient bladders to adherence in bladders treated with one of several suspected urinary carcinogens. There were statistically significant differences between adherence in control bladders and adherence in bladders treated with the tryptophan metabolites 3-hydroxykynurenine and 3-hydroxyanthranilic acid, sodium cyclamate, and sodium saccharin. These data indicate that perhaps certain suspected urinary bladder carcinogens inactivate the anti-adherence effect of the glycosaminoglycan layer at the bladder surface and thereby penetrate to the transitional cells to exert their tumorigenic effects; or they may serve as cocarcinogens that inactivate the glycosaminoglycan barrier and permit other urinary carcinogens to transform the transitional cells.

3-Hydroxyanthranilic Acid↗
PubMed1987

Functional and structural characteristics of the glycosaminoglycans of the bladder luminal surface.

The glycosaminoglycan layer of bladder has been proposed to play a crucial role in protecting the bladder from harmful substances in urine. Rats were partially cystectomized to determine whether bladder glycosaminoglycans are routinely eluted from the bladder surface in detectable quantities. Cystectomy produced no detectable qualitative or quantitative changes in excreted GAG thereby showing that most urinary glycosaminoglycan originates in the kidney and not from the bladder. Damaging the glycosaminoglycan layer by a dilute acid wash, however, leads to a consistent decrease in the output of urinary GAG which recovers to normal at the same rate as the layer regenerates. This suggests that the newly exposed sites tightly bind urinary GAG. We suggest that such binding may be a component of the normal physiological defense mechanism of the bladder. The bladder glycosaminoglycan layer was isolated, dilute acid being used to elute ionically-bound material and brief trypsinization to elute intercalated proteoglycans from the luminal surface. The GAG from the luminal surface, which was present at a density of one chain per 50 nm.2 of bladder surface, was quite different in composition from that isolated from the whole bladder.

Animals↗
PubMed1987

Successful therapy of interstitial cystitis with pentosanpolysulfate.

Sodium pentosanpolysulfate (Elmiron) is a synthetic, sulfated polysaccharide available in an oral form that is excreted into the urine. This drug was used in a double-blind fashion to evaluate its efficacy in the management of symptoms of interstitial cystitis. A dose of 100 mg. 3 times daily was used for a minimum of 4 months and was continued for longer than 18 months in some individuals. A total of 62 patients was evaluated from 2 different medical centers. Subjective improvements were greater in all parameters when the drug was compared to placebo therapy, with significant improvement in pain, urgency, frequency and nocturia. Objective improvement in average voided volumes was greater with the drug than with placebo (p equals 0.009). No significant difference was found between drug and placebo groups in the average number of daily voiding episodes.

Clinical Trials as Topic↗
PubMed1987

Effect of tongue reduction on articulation in children with Down syndrome.

Tongue-reduction surgery was completed on 18 children with Down syndrome. Changes in articulation were evaluated pre- and postoperatively and at a 6-month follow-up. No significant differences in the number of articulation errors were found. The postoperative and 6-month follow-up scores of the surgery group were compared to a nonsurgery (contrast) group (N = 9) who had received two evaluations 6 months apart. Again, no significant differences were found. A follow-up survey of parental ratings on articulation of the surgery and nonsurgery group revealed that there were no significant differences between the groups but that parents of all the children claimed that "speech" had improved over the 6-month time period. These findings suggest that tongue-reduction surgery has no effect on the articulation of sounds.

Adolescent↗
PubMed1987

Lower urinary tract infections in women.

The combination of increased ability of the bacteria to adhere plus susceptible epithelial cells appears to predispose certain women to infection. The author presents a practical approach to the selection and employment of common urinary tract agents for pre- and postmenopausal women. Discussed are therapeutic goals, initial and chronic therapy, and complications of treatment (in postmenopausal women, pregnancy, and renal failure).

Adult↗
PubMed1987

Prophylactic antibiotics in urology.

The emergence of prosthetic surgery and nonoperative surgical treatment of urolithiasis has seen with it an expanded application of prophylactic antibiotics. The very nature of these procedures with the often increased risk of infectious complications lends itself perfectly to wider but more judicious use of prophylactic antibiotics. Controlled clinical trials that address issues such as dosing, selection, and indications for antibiotic prophylaxis are lacking. Until that information is forthcoming, only recommendations can be made as we have tried to provide in this article.

Anti-Bacterial Agents↗