EFFECTS OF SODIUM HYALURONATE ON EPITHELIAL HEALING OF THE VESICAL MUCOSA AND VESICAL FIBROSIS IN RABBITS WITH ACETIC ACID INDUCED CYSTITIS

A Case Report of the Treatment of Diabetic Foot Ulcers Using a Sodium Hyaluronate and Iodine Complex

Diabetic foot ulcers are difficult to heal due to defects in local microvasculature and persistent, concomitant infection. Despite the best medical care, amputation is often a management option for this problem. The authors have developed a new and unique system for wound treatment, which is based on a combination of high molecular weight sodium hyaluronate with an iodine complex—Hyiodine® (Contipro C, Dolní Dobrouc, Czech Republic). In this case report, the authors present an observational study on a series of patients with diabetic foot disease with nonhealing wounds treated with Hyiodine. The effect of the HA-iodine complex was studied on 18 patients suffering from complicated foot diabetic wounds. The HA-iodine complex was either spread directly over the wound, or more frequently, gauze was immersed in the HA-iodine complex and then put on/into the wound. Then several layers of dry gauze covered the wound. This dressing was changed every 24 hours. Wound healing was monitored daily, and wound pictures were taken each second week. Clinical improvement was observed in the majority. This suggests that the HA-iodine complex dressing has potential that needs to be developed from controlled studies.

Intravesical hyaluronic acid treatment improves bacterial cystitis and reduces cystitis-induced hypercontractility in rats

OBJECTIVE

To investigate the effect of intravesical hyaluronic acid on Escherichia coli-induced cystitis and cystitis-induced hypercontractility in rats.

METHODS

Bacterial cystitis was induced in Wistar female rats by intravesical inoculation of E. coli. Isotonic saline was instilled in the control group (n = 6). The rats were either non-treated, treated with gentamycin (4 mg/kg, 5 days) or treated intravesically with hyaluronic acid (0.5 mL, 0.5%). On the eighth day, the bladder tissues were excised for histological examination, and the measurements of myeloperoxidase, superoxide dismutase and catalase activities. Contraction/relaxation responses to carbachol, isoprotrenol and papaverine were studied.

RESULTS

Tissue myeloperoxidase activity was increased, but superoxide dismutase and catalase activities were decreased in bacterial cystitis, while hyaluronic acid treatment reversed these changes. In the hyaluronic acid-treated group, healing of the uroepithelium was observed, while decreased inflammatory cell infiltration was obvious in gentamycin-treated group. E. coli-induced cystitis in all rats resulted in increased contraction responses to carbachol compared with controls (P < 0.01). Treatment with hyaluronic acid, but not gentamycin, significantly (P < 0.05) depressed hypercontractility at maximum carbachol concentrations. In all rats with cystitis, papaverine-induced relaxation was increased, whereas isoproterenol-induced relaxation curves were not different between the studied groups.

CONCLUSION

Gentamycin treatment, despite its ameliorative effect on inflammation, had no impact on the contractile dysfunction of the injured bladder. Intravesical hyaluronic acid, in addition to its supportive role in the healing of the epithelium, seems to lower the increased threshold for contraction and to reduce oxidative stress. These findings support a potential role for hyaluronic acid in the treatment of bacterial cystitis.

A mouse model for interstitial cystitis/painful bladder syndrome based on APF inhibition of bladder epithelial repair: a pilot study

BACKGROUND

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a chronic bladder disorder with bladder epithelial thinning or ulceration, pain, urinary frequency and urgency. There is no reliably effective therapy for IC/PBS, and no generally accepted animal model for the disorder in which potential therapies can be tested. Bladder epithelial cells from IC/PBS patients make a small glycopeptide antiproliferative factor or "APF" that inhibits proliferation, decreases tight junction protein expression, increases paracellular permeability, and induces changes in gene expression of bladder epithelial cells in vitro that mimic abnormalities in IC/PBS patient biopsy specimens in vivo. We therefore determined the ability of a synthetic APF derivative to inhibit bladder epithelial repair in mice.

METHODS

The bladder epithelium of female CBA/J mice was stripped by transurethral infusion of 3% acetic acid, and mice were subsequently treated daily with one of three intravesical treatments [synthetic as-APF, inactive unglycosylated control peptide, or phosphate buffered saline carrier (PBS)] for 1-21 days. Fixed bladder sections were either stained with haematoxylin and eosin for determination of epithelial area by image analysis, or incubated with anti-uroplakin III (UPIII) or anti-zonula occludens type 1 (ZO-1) antibodies for immunofluorescence microscopy. Epithelial measurement data were analyzed by a two-way analysis of variance (ANOVA); post hoc comparisons of multiple groups were carried out using the Tukey-Kramer method.

RESULTS

Bladder epithelial repair was significantly attenuated in as-APF-treated mice as compared to control mice on days 3-21 (p < 0.05); the mean epithelial/total area over all measured days was also significantly lower in as-APF-treated mice vs. mice in either control group by post hoc analysis (p < 0.0001 for both comparisons). UPIII and ZO-1 expression was also decreased in as-APF-treated mice as compared to mice in either control group by day 7 (UPIII) or day 14 (ZO-1).

CONCLUSIONS

This model demonstrates in vivo effects of as-APF which abrogates bladder epithelial repair and expression of UPIII and ZO-1 in CBA/J mice following transurethral acetic acid infusion. As bladder epithelial thinning, decreased UPIII expression, and decreased ZO-1 expression are histopathologic features of IC/PBS patient biopsies, this model may be useful for studying the pathophysiology of IC/PBS and the effect of potential therapies.

Preventive effects of hyaluronic acid on Escherichia coli-induced urinary tract infection in rat

OBJECTIVES

To investigate the effects of hyaluronic acid (HA) in rat with Escherichia coli-induced urinary tract infection and duration of its effect. HA is a component of the glycosaminoglycan layer, and is known to interfere with the attachment of E. coli to the urothelium.

METHODS

The rats were divided into various groups. The E. coli-only group in which phosphate-buffered saline was instilled before E. coli (fimH+, sfa+, papA+) inoculation; HA-1, HA-3, HA-5, and HA-7 groups in which HA (0.5 mL, 0.5%) was instilled 1, 3, 5, 7 days before E. coli inoculation, respectively. To assess the symptomatic changes, we examined the voiding interval (VI) of E. coli-only group and HA-1 group before and after E. coli inoculation. Atomic force microscopy was performed to investigate the change in the urothelium before and after HA treatment.

RESULTS

Bacterial growth rate in the bladder was significantly higher in the E. coli-only group (84.6%) than in the HA-1 (20.0%), HA-3 (23.5%), and HA-5 groups (7.7%) (P <.05). The VI in E. coli-only group decreased from the first to third day after the induction of cystitis. The VI in E. coli-only group was significantly shorter than in HA-1 group (P <.05). No pathological evidence of acute inflammation was observed in the bladder and kidney of culture-negative HA groups. Atomic force microscopy showed HA coating on the urothelium.

CONCLUSIONS

This study shows that HA has an effect on the protection mechanism against the invasion of E. coli and that its effect duration is about seven days.

Formulation study of intravesical oxybutynin instillation solution with enhanced retention in bladder

A formulation study of intravesical oxybutynin (OB) preparations was carried out in order to improve the effectiveness in intravesical instillation therapy for spastic neurogenetic bladder. Sodium hyaluronate (HYA) was introduced to enhance the muco-adhesiveness of the instillation preparation, and the physicochemical properties of the OB formulation were evaluated in comparison with a conventional formulation containing hydroxypropylcellulose (HPC). The viscous properties and in vitro adhesiveness increased with the amount of the polymeric additives, and retention properties of OB in rabbit bladder were comparable after addition of 0.4% HYA and 1.0% HPC. HYA was able to enhance the intravesical retention properties of OB instillation solution to a lesser degree than HPC, it seemed to be a useful additive in the OB instillation due to its safety and mucosal-protective effect.

Treatment approaches for painful bladder syndrome/interstitial cystitis

Painful bladder syndrome/interstitial cystitis (PBS/IC) is a disease of unknown aetiology, characterised by severe pressure and pain in the bladder area or lower pelvis that is frequently or typically relieved by voiding, along with urgency or frequency of urination in the absence of urinary tract infections. PBS/IC occurs primarily in women, is increasingly recognised in young adults, and may affect as many as 0.1-1% of adult women. PBS/IC is often comorbid with allergies, endometriosis, fibromyalgia, irritable bowel syndrome and panic syndrome, all of which are worsened by stress. As a result, patients may visit as many as five physicians, including family practitioners, internists, gynaecologists, urologists and pain specialists, leading to confusion and frustration. There is no curative treatment; intravesical dimethyl sulfoxide, as well as oral amitriptyline, pentosan polysulfate and hydroxyzine have variable results, with success more likely when these drugs are given together. Pilot clinical trials suggest that the flavonoid quercetin may be helpful. Lack of early diagnosis and treatment can affect outcomes and leads to the development of hyperalgesia/allodynia.

Topical high molecular weight hyaluronan reduces radicular pain post laminectomy in a rat model

BACKGROUND CONTEXT

A controversy exists about the mechanism of causation of the post-laminectomy pain syndrome. Some believe that epidural scarring, and attendant spinal nerve and nerve root scarring and tethering to the disc or pedicle at the site of surgery contributes to post-laminectomy pain in such patients. However, clinical outcome studies on this question are inconclusive and the assertion remains controversial. Definitive studies to help resolve the question are needed. Previously our laboratory has reported on a preclinical post-laminectomy model that mimics the postoperative proliferative fibrotic response grossly, as well as by biochemical assessment of the collagen content within the spinal canal. The post-laminectomy fibrotic response was attenuated in that study by application of a topical antifibrotic (high molecular weight hyaluronan gel) or by insertion of an absorbable roofing barrier (0.2-mm-thick Macropore sheet material) over the laminectomy defect before wound closure. The question remains of relevance of the attenuation of the fibrotic response to post-laminectomy chronic pain syndromes.

PURPOSE

The purpose of this study is to evaluate the effect of therapeutic attenuation of proliferative scar within the spinal canal post laminectomy on the pain-related behavioral response in a preclinical rat model.

STUDY DESIGN/SETTING

An established L5-L6 rat laminectomy model with a unilateral L5-6 disc injury was employed to assess postoperative proliferative fibrosis of the L5 spinal nerves using quantitative biochemical hydroxyproline assessment of the collagen content in four experimental groups. These observations were correlated with gross descriptions of spinal nerve scarring or tethering. Associated manifestations of a sensory pain-related response in the L5 spinal nerve receptor area of the hind paws was studied using standard tactile allodynia assessment with the von Frey hair technique. The tactile allodynia findings were supplemented by weekly descriptors of behavioral pain manifestations.

METHODS

Bilateral laminectomies at L5 and L6 and a unilateral right disc injury (L5-6) were performed on 35 male adult Sprague-Dawley rats, weighing 400+ grams (approved by the VA Institutional Animal Care Use Committee). The study consisted of four groups: 1) normal nonoperative control; 2) a sham-operated group; 3) an untreated laminectomy-disc injury group; and 4) a laminectomy-disc injury treatment group in which 0.1 cc topical high molecular weight hyaluronan (HMW HA) gel was layered over the dura and into the laminectomy canal before closure. Before animals were entered into the study, they were checked for the presence of abnormal response to the tactile testing procedure of the L5 sensory receptor area. Animals exhibiting anomalous responses were excluded from the study. Behavioral testing for tactile allodynia was performed at weekly intervals post laminectomy beginning at 3 weeks. Pain-related behavior was characterized at weekly intervals. A behavioral test cage with a wire mesh floor allowed for tactile allodynia testing. Graduated von Frey hairs whose stiffness increased logarithmically from 0.41 to 15 g were used for tactile allodynia tests. The animals were killed 8 weeks postoperatively for analysis. The dissected spinal nerve and nerve root specimens were studied biochemically for hydroxyproline content to estimate total collagen in and around the L5 neural structures. Statistical analyses were performed using analysis of variance and a Fisher comparison t test.

RESULTS

The major observations on the untreated preclinical post-laminectomy rat model previously described by this laboratory were confirmed. All untreated animals developed a tail contracture concave toward the right (disc injury side) consistent with asymmetrical lumbar muscle spasm. Only one animal in the HA gel treatment group had a tail contracture. It was of mild degree and occurred in an animal that demonstrated slightly increased right L5 tactile sensitivity. Gross inspection of the dissected specimens demonstrated spinal nerve scarring and tethering to the disc and pedicle greater on the right than the left in untreated animals, findings that were markedly reduced in the treatment group. Collagen content of the L5 spinal nerve and nerve roots with attached scar were significantly lower in the HA gel treatment group than in the untreated laminectomy group (p=.0014). Pain behavioral testing of the L5 receptor area of the right hind paw in the untreated laminectomy group showed markedly increased sensitivity to tactile allodynia testing compared with the corresponding limb of the control group (p=.0001), to the corresponding limb of the sham group (p=.0001), and compared with the HMW HA gel treatment group (p=.0010). Comparisons of the pain behavioral data between the sham and the post-laminectomy HA gel treatment group and the control animals lacked statistical significance.

CONCLUSION

This study supports the concept of a relationship between perineural fibrosis and radicular neuropathy in the model described, and emphasizes the role of disc injury and spinal nerve retraction in the post-laminectomy fibrotic process. Furthermore, it shows promise for preliminary assessment of interventions with other anti-inflammatory agents, for characterization of the neurochemical profile of the post-laminectomy pain state, and for exploration of newer pharmaceutical agents potentially useful in the prevention or management of the post-laminectomy syndrome. Post-laminectomy scar is but one of many potential causes of the post-laminectomy pain syndrome. Furthermore, a cautionary note must be emphasized as in all studies using preclinical models, conclusions drawn from the studies cannot be extended directly to patients without confirmatory clinical follow-up studies.