Electrodynamics of lipid membrane interactions in the presence of zwitterionic buffers.

Due to thermal motion and molecular polarizability, electrical interactions in biological systems have a dynamic character. Zwitterions are dipolar molecules that typically are highly polarizable and exhibit both a positive and a negative charge depending on the pH of the solution. We use multilamellar structures of common lipids to identify and quantify the effects of zwitterionic buffers that go beyond the control of pH. We use the fact that the repeat spacing of multilamellar lipid bilayers is a sensitive and accurate indicator of the force balance between membranes. We show that common buffers can in fact charge up neutral membranes. However, this electrostatic effect is not immediately recognized because of the concomitant modification of dispersion (van der Waals) forces. We show that although surface charging can be weak, electrostatic forces are significant even at large distances because of reduced ionic screening and reduced van der Waals attraction. The zwitterionic interactions that we identify are expected to be relevant for interfacial biological processes involving lipid bilayers, and for a wide range of biomaterials, including amino acids, detergents, and pharmaceutical drugs. An appreciation of zwitterionic electrodynamic character can lead to a better understanding of molecular interactions in biological systems and in soft materials in general.

Transobturator tape removal using a combined vaginal-transcutaneous approach for intractable groin pain.

BACKGROUND: : Transient groin pain is a therapeutically challenging complication associated with transobturator sling procedures. CASE: : We present the case of a 37-year-old woman who presented with debilitating left groin pain and dyspareunia following placement of transobturator sling. Pelvic floor physical therapy, medications, and trigger point injections failed to provide relief. Workup included magnetic resonance imaging of the pelvis, complex cystometrics, and additional trigger point injections. Surgical removal of the complete left side of the tape including the portion imbedded in the obturator foramen was performed with a combined vaginal-transcutaneous approach. Extirpation of the mesh arm brought prompt and full resolution of the patient's symptoms. CONCLUSIONS: : Surgical removal of the transobturator tape through the obturator foramen can be safely performed using a combined vaginal-transcutaneous approach.

Interposition grafts for rectovaginal fistula repair in the New Zealand white rabbit.

INTRODUCTION AND HYPOTHESIS: The objective was to use an animal model to study different types of interposition grafts for rectovaginal fistula repair. METHODS: Twelve New Zealand white rabbits underwent surgical creation of a rectovaginal fistula, followed by repair. Four repair techniques were studied; three with interposition grafts and one control group without a graft. Animals were euthanized at 4-week intervals and underwent gross and histologic analysis. RESULTS: The mean rectovaginal wall thickness was greatest in the control group (5.6 mm) and thinnest in the autologous rectus fascia (4.2 mm) and porcine small intestine submucosa (5.1 mm) groups. The polypropylene graft had a mean thickness of 5.4 mm and elicited a strong, protracted inflammatory response. All fistulas were successfully closed except one porcine small intestine submucosa repair. CONCLUSIONS: There is no benefit from interposition graft use for rectovaginal fistula repair in our New Zealand white rabbit model.

Rectovaginal fistula model in the New Zealand white rabbit.

INTRODUCTION AND HYPOTHESIS: The purpose of this study was to create an animal model to study rectovaginal fistula repair. METHODS: Fourteen New Zealand white rabbits underwent surgical creation of a rectovaginal fistula. The technique was developed with a pilot study conducted on the first two animals, then standardized and performed on the remaining 12 rabbits. The standardized technique included making a defect in the rectovaginal septum using a 3-mm skin punch then splinting the defect with 6-mm tubing for 2 weeks. RESULTS: Using the standardized technique, a fistula was successfully created in all 12 rabbits ranging from 1 to 5 mm (mean = 2.8 mm, SD = 1.1). A 95% tolerance interval was calculated for the model and predicted that a successful fistula can be created ranging from 0.3 to 5.2 mm in 85% of attempts with the model. CONCLUSION: The New Zealand white rabbit is a promising animal model to study rectovaginal fistula repair.

Sacral neuromodulation in the treatment of vulvar vestibulitis syndrome.

BACKGROUND: Vulvar vestibular syndrome is a chronic pain syndrome that typically results in pain and irritation of the vulvar vestibule and has few effective options for treatment. CASE: A 42-year-old woman presented with symptoms consistent with chronic vulvar vestibular syndrome that was refractory to multiple attempted therapies. The patient was offered sacral neuromodulation for treatment. She underwent a standard two-phase surgical implantation with good result at 2 years postimplantation. CONCLUSION: Sacral neuromodulation was shown to be a valid treatment option for this patient and resulted in excellent patient satisfaction at 2-year follow-up. Although the exact mechanism of action is unknown, sacral neuromodulation may be a viable option for the management of chronic pain syndromes of the vulva and vagina.

The racial distribution of female pelvic floor disorders in an equal access health care system.

PURPOSE: We examined ethnic differences in female pelvic disorders in an equal access health care system. MATERIALS AND METHODS: An electronic medical record review was performed for patients with pelvic floor disorders at a military female pelvic medicine and reconstructive surgery division for a 1-year period. Primary diagnosis codes and patient reported race were reviewed. RESULTS: Mean +/- SD cohort age was 55 +/- 16.3 years. A total of 720 patients were identified, of whom 68.8% were white and 18.6% were black. Pelvic organ prolapse was the primary diagnosis in 34.2% of the women, while 19.7% had stress urinary incontinence and 10.8% had urge urinary incontinence. There was no difference in the prevalence of prolapse between black and white women. However, of patients with incontinence there was a statistically significant difference with urge incontinence in more black women (51.2%) and stress incontinence in more white women (66.2%) (chi-square p <0.05). CONCLUSIONS: There is a similar ethnic distribution of pelvic organ prolapse in an equal access health care system. Of women with incontinence there was a higher prevalence of urge urinary incontinence in black women and a higher prevalence of stress urinary incontinence in white women.

Utility of ultrasound in the combat theater: experiences of a gynecologist during Operation Iraqi Freedom/Operation Enduring Freedom.

OBJECTIVE: The purpose of this study was to evaluate the utility of ultrasound in a combat theater. METHODS: A retrospective review of gynecology visits was evaluated at Camp Doha, Kuwait, from August 2003 through April 2004. Of the 1,737 visits, 237 required pelvic ultrasound. Demographic information, as well as the indications, diagnosis, and disposition of the patients, was compiled. RESULTS: The average age of the patient requiring ultrasound was 28 +/- 8 years. The primary presenting complaint was pelvic pain. Forty percent with pelvic pain had no identifiable cause. The most common final diagnosis was pregnancy. Of the 237 visits, the use of ultrasound resulted in 136 return-to-duty dispositions. Of the 31% who were administratively redeployed, the majority were secondary to pregnancy. CONCLUSION: Gynecologic ultrasound was found to be a very useful tool in the combat theater. Ultrasound resulted in improved diagnostic ability and enhanced reassurance to both provider and patient.

Pregnancy during Operation Iraqi Freedom/Operation Enduring Freedom.

OBJECTIVE: The purpose of this study was to evaluate pregnancy during war-time deployment. METHODS: A retrospective review of gynecology visits was evaluated at Camp Doha, Kuwait, from August 2003 through April 2004. Of the 1,737 visits, 77 demonstrated a positive pregnancy test. These charts were evaluated for factors that may lead to important information for future deployments. RESULTS: The average age of the female soldier with a positive pregnancy test in theater was 27 +/- 7 years. The primary presenting complaint was amenorrhea. Ninety-two percent had an ultrasound. Fifty-four percent of visits were active duty, followed by Reserve, National Guard, and civilian government employees. Ninety-two percent were administratively redeployed. Seventy-seven percent of the soldiers became pregnant in country. Twenty-three percent arrived in country pregnant. CONCLUSIONS: Given the number of pregnancies before and during deployment, current screening procedures as well as new concepts in prevention need to be addressed.

Sexually transmitted diseases in Operation Iraqi Freedom/Operation Enduring Freedom.

OBJECTIVE: To identify the incidence of sexually transmitted diseases (STDs) in a female active duty population deployed in support of Operation Iraqi Freedom/Operation Enduring Freedom was the objective of this study. METHODS: Retrospective chart review was completed on all soldiers seeking outpatient gynecologic care at Camp Doha, Kuwait, from September 2003 through March 2004. Descriptive statistical analysis was performed on data from all patients identified as having an STD. RESULTS: Forty-four soldiers (2.5% of all encounters) were diagnosed with STDs during the study period. Genital herpes, Condyloma acuminata, and chlamydia were the most commonly identified infections accounting for 30, 25, and 21% of the diagnoses, respectively. CONCLUSION: Transmission of STDs in the deployed environment continues to be problematic. Viral infections were more commonly encountered than were bacterial infections. Patient education and prevention should be emphasized. Consideration should be given to STD screening upon redeployment.

Pelvic pain presenting in a combat environment.

OBJECTIVE: The objective was to identify the incidence of pain disorders in the deployed female active duty population in support of Operation Iraqi Freedom. METHODS: Retrospective chart review was completed on all patients who were seen for gynecologic services at Camp Doha, Kuwait, from September 2003 through March 2004. One thousand seven hundred thirty-seven patients were identified. Statistical analysis was performed. RESULTS: Of the 1,737 patients seen during the study period, 150 patients were identified as having a pelvic pain disorder. These patients accounted for 14% of all patients seen for gynecologic services. Mean age was 28 +/- 8 years (range, 15-53 years). Pelvic pain of unclear etiology and cystitis were the most common diagnoses made accounting for 19% and 16% of encounters. CONCLUSIONS: Acute pelvic pain disorders can be effectively managed in the combat environment. Optimization of predeployment regimens for management of pain is strongly recommended. Consideration should be given to making soldiers with chronic pelvic pain disorders that fail to respond to predeployment medical management nondeployable.