Cutaneous stimulation from patella tape causes a differential increase in vasti muscle activity in people with patellofemoral pain

Patella taping reduces pain ill individuals with patellofemoral pain (PFP), although the mechanism remains unclear. One possibility is that patella taping modifies vasti muscle activity via stimulation of cutaneous afferents. The aim of this study was to investigate the effect of stretching the skin over the patella on vasti Muscle activity in people with PFP. Electromyographic activity (EMG) of individual motor units in vastus medialis obliquus (VMO) was recorded via a needle electrode and from Surface electrodes placed over VMO and vastus lateralis (VL). A tape was applied to the skin directly over the patella and stretch was applied via the tape in three directions, while subjects maintained a gentle isometric knee extension effort at constant force. Recordings were made from five separate motor units in each direction. Stretch applied to the skin over the patella increased VMO surface EMG and was greatest with lateral stretch. There was no change in VL surface EMG activity. While there was no net increase in motor unit firing rate, it was increased in the majority of motor units during lateral stretch. Application of stretch to the skin over VMO via the tape can increase VMO activity, suggesting that cutaneous stimulation may be one mechanism by which patella taping produces a clinical effect. (c) 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.

A randomized, controlled trial to determine the efficacy of paper tape in preventing hypertrophic scar formation in surgical incisions that traverse Langer's skin tension lines

Background: How a scar is managed postoperatively influences Its cosmetic outcome. After Suture removal, scars are susceptible to skin tension, which may be the trigger for hypertrophic scarring. Paper tape to support the scar may reduce multidirectional forces and prevent hypertrophic scarring. Methods: Seventy patients who had under gone cesarean section at the Royal Brisbane and Women's Hospital were randomized to treatment and control groups. Patients in the control group received no postoperative intervention. Patients in the treatment group applied paper tape to their scars for 12 weeks. Scars were assessed at 6 weeks, 12 weeks, and 6 months after surgery using Ultrasound to measure intradermal scar volume. Scars were also assessed using the International Clinical Recommendations. Results: Paper tape significantly decreased scar volume by a mean of 0.16 cm(3), (95 percent confidence Interval, 0.00 to 0.29 cm(3)) At 12 weeks after surgery, 41 percent of the control group developed hypertrophic scars compared with none in the treatment group (exact test, p = 0.003). In the treatment group, one patient developed a hypertrophic scar and four developed stretched scars only after the tape was removed. The odds of developing a hypertrophic scar were 13.6 times greater in the control than in the treatment group (95 percent confidence interval, 3.6 to 66.9). Of the 70 patients randomized, 39 completed the study. Four patients in the treatment group developed a localized red rash beneath the tape. These reactions were minor and transient and resolved without medical intervention. Conclusions: The development of hypertrophic and stretched scars in the treatment group only after the tape was removed suggests that tension acting on a scar is die trigger for hypertrophic scarring. Paper tape is likely to be an effective modality for the prevention of hypertrophic scarring through its ability to eliminate scar tension.

Endometrial and vaginal effects of low-dose estradiol delivered by vaginal ring or vaginal tablet

Aims The major aims of the study were to compare the safety of a continuous low-dose estradiol-releasing vaginal ring (ESTring) to that of a vaginal estradiol tablet (Vagifem®) on the endometrium and the relief of subjective symptoms and signs of urogenital estrogen deficiency. Quality of life and acceptability of treatment delivery were also assessed. Study design A prospective, randomized study in which women were assigned in a 2: 1 ratio to ESTring and Vagifem and followed for 12 months. The primary endpoint was endometrial safety, based on the results of ultrasound measurement of endometrial thickness and a progestogen challenge test at baseline and week 48. Efficacy was determined by subjective assessment of urogenital estrogen deficiency symptoms at baseline and weeks 3, 12, 24, 36 and 48 and assessment of signs of vaginal epithelial atrophy by the clinician at baseline, 12 and 48 weeks. In addition, pelvic floor strength, vaginal cytological evaluation and pH, bacteruria and patient acceptability were assessed. Quality of life was assessed using a menopause-specific quality-of-life questionnire and a 2-day bladder diary at baseline and 12 and 48 weeks. The comparability of the two groups was assessed using ANOVA, χ(2) or Fisher's exact tests. Results A total of 126 women were randomized to ESTring and 59 to Vagifem. There was no statistical difference between the groups in the alleviation of symptoms and signs of urogenital estrogen deficiency. Maturation indices increased in both groups, from generally atrophic at baseline to proliferative or highly proliferative at 48 weeks. After 48 weeks of treatment, there was no statistically significant difference in endometrial thickness between the two groups. A statistically smaller proportion of bleeding/spotting occurred in the ESTring group (n = 0) compared to the Vagifem users (n = 4). Estradiol and total estrone serum levels increased during treatment in both groups but remained within the normal postmenopausal range. General health status in both groups was unchanged but the urogenital component of health burden was significantly improved in both groups. Bladder diary variables showed no differences between treatment groups. Conclusion Equivalent endometrial safety and efficacy in the relief of the symptoms and signs of urogenital estrogen deficiency were demonstrated for the 12 months' use of a low-dose estradiol-releasing vaginal ring and a vaginal estradiol tablet.

Postoperative analgesic requirements - total laparoscopic hysterectomy versus vaginal hysterectomy

Background: There is limited information available on the requirement for postoperative analgesic drugs in patients submitted to total laparoscopic hysterectomy (TLH) compared with patients undergoing vaginal hysterectomy (VH). Aim: To compare the postoperative analgesic requirements in patients who underwent a TLH with patients who had a VH. Methods: Chart review of 53 patients who had TLH and 47 who had VH and were seen postoperatively by an acute pain management service in order to assess postoperative analgesic requirements. Patient controlled analgesia (PCA) was part of the standard protocol for postoperative pain management. Analgesic requirement was recorded as the mean doses of morphine and number of days that patients used non-steroidal anti-inflammatory drugs (NSAIDs), oxycodone and tramadol. Results: The requirement for total morphine was approximately half the dose in patients who had a TLH (10.8 +/- 12.6 mg) compared with patients who had a VH (19.4 +/- 21.9 mg) (P 0.017). The length of use of NSAIDs was significantly reduced in patients who had undergone a TLH (2.0 +/- 0.95 days) as compared with patients who had a VH (2.85 +/- 1.1 days) (P < 0.0001). Conclusions: Patients submitted to TLH require less postoperative analgesic drugs when compared with patients who had VH. Prospective randomised trials are warranted to compare analgesic requirements between patients submitted to TLH and VH.

Characterisation of protein stability in rod-insert vaginal rings

A major goal in vaccine development is elimination of the 'cold chain', the transport and storage system for maintenance and distribution of the vaccine product. This is particularly pertinent to liquid formulation of vaccines. We have previously described the rod-insert vaginal ring (RiR) device, comprising an elastomeric body into which are inserted lyophilised, rod-shaped, solid drug dosage forms, and having potential for sustained mucosal delivery of biomacromolecules, such as HIV envelope protein-based vaccine candidates. Given the solid, lyophilised nature of these insert dosage forms, we hypothesised that antigen stability may be significantly increased compared with more conventional solubilised vaginal gel format. In this study, we prepared and tested vaginal ring devices fitted with lyophilised rod inserts containing the model antigen bovine serum albumin (BSA). Both the RiRs and the gels that were freeze-dried to prepare the inserts were evaluated for BSA stability using PAGE, turbidimetry, microbial load, MALDI-TOF and qualitative precipitate solubility measurements. When stored at 4°C, but not when stored at 40°C/75% RH, the RiR formulation offered protection against structural and conformational changes to BSA. The insert also retained matrix integrity and release characteristics. The results demonstrate that lypophilised gels can provide relative protection against degradation at lower temperatures compared to semi-solid gels. The major mechanism of degradation at 40°C/75% RH was shown to be protein aggregation. Finally, in a preliminary study, we found that addition of trehalose to the formulation significantly reduces the rate of BSA degradation compared to the original formulation when stored at 40°C/75% RH. Establishing the mechanism of degradation, and finding that degradation is decelerated in the presence of trehalose, will help inform further development of RiRs specifically and polymer based freeze-dried systems in general.

Molecular investigations into vaginal immunization with HIV gp41 antigenic construct H4A in a quick release solid dosage form

A robust vaginal immune response is considered essential for an effective prophylactic vaccine that prevents transmission of HIV and other sexually acquired diseases. Considerable attention has recently focused on the potential of vaginally administered vaccines as a means to induce such local immunity. However, the potential for vaccination at this site remains in doubt as the vaginal mucosa is generally considered to have low immune inductive potential. In the current study, we explored for the first time the use of a quick release, freeze-dried, solid dosage system for practical vaginal administration of a protein antigen. These solid dosage forms overcome the common problem associated with leakage and poor retention of vaginally administered antigen solutions. Mice were immunized vaginally with H4A, an HIV gp41 envelope based recombinant protein, using quick release, freeze-dried solid rods, and the immune responses compared to a control group immunized via subcutaneous H4A injection. Vaginally immunized mice failed to elicit robust immune responses. Our detailed investigations, involving cytokine analysis, the stability of H4A in mouse cervicovaginal lavage, and elucidation of the state of H4A protein in the immediate-release dosage form, revealed that antigen instability in vaginal fluid, the state of the antigen in the dosage form, and the cytokine profile induced are all likely to have contributed to the observed lack of immunogenicity. These are important factors affecting vaginal immunization and provide a rational basis for explaining the typically poor and variable elicitation of immunity at this site, despite the presence of immune responsive cells within the vaginal mucosae. In future mucosal vaccine studies, a more explicit focus on antigen stability in the dosage form and the immune potential of available antigen-responsive cells is recommended.

Non-aqueous silicone elastomer gels as a vaginal microbicide delivery system for the HIV-1 entry inhibitor maraviroc

Aqueous semi-solid polymeric gels, such as those based on hydroxyethylcellulose (HEC) and polyacrylic acid (e.g. Carbopol®), have a long history of use in vaginal drug delivery. However, despite their ubiquity, they often provide sub-optimal clinical performance, due to poor mucosal retention and limited solubility for poorly water-soluble actives. These issues are particularly pertinent for vaginal HIV microbicides, since many lead candidates are poorly water-soluble and where a major goal is the development of a coitally independent, once daily gel product. In this study, we report the use of a non-aqueous silicone elastomer gel for vaginal delivery of the HIV-1 entry inhibitor maraviroc. In vitro rheological, syringeability and retention studies demonstrated enhanced performance for silicone gels compared with a conventional aqueous HEC gel, while testing of the gels in the slug model confirmed a lack of mucosal irritancy. Pharmacokinetic studies following single dose vaginal administration of a maraviroc silicone gel in rhesus macaques showed higher and sustained MVC levels in vaginal fluid, vaginal tissue and plasma compared with a HEC gel containing the same maraviroc loading. The results demonstrate that non-aqueous silicone gels have potential as a formulation platform for coitally independent vaginal HIV microbicides.

Sustained release of the CCR5 inhibitors CMPD167 and maraviroc from vaginal rings in rhesus macaques

Antiretroviral entry inhibitors are now being considered as vaginally administered microbicide candidates for the prevention of the sexual transmission of human immunodeficiency virus. Previous studies testing the entry inhibitors maraviroc and CMPD167 in aqueous gel formulations showed efficacy in the macaque challenge model, although protection was highly dependent on the time period between initial gel application and subsequent challenge. In this paper, we describe the sustained release of maraviroc and CMPD167 from matrix-type silicone elastomer vaginal rings both in vitro and in vivo. Both inhibitors were released continuously during 28 days from rings in vitro at rates of 100 to 2,500 µg/day. In 28-day pharmacokinetic studies in rhesus macaques, the compounds were measured in the vaginal fluid and vaginal tissue; steady-state fluid concentrations were ~10(6)-fold greater than the 50% inhibitory concentrations (IC(50)s) for simian human immunodeficiency virus 162P3 inhibition in macaque lymphocytes in vitro. Plasma concentrations for both compounds were very low. The pretreatment of macaques with Depo-Provera (DP), which is commonly used in macaque challenge studies, was shown to significantly modify the biodistribution of the inhibitors but not the overall amount released. Vaginal fluid and tissue concentrations were significantly decreased while plasma levels increased with DP pretreatment. These observations have implications for designing macaque challenge experiments and also for ring performance during the human female menstrual cycle.