Supramolecular Fibrous Hydrogel Augmentation of Uterosacral Ligament Suspension for Treatment of Pelvic Organ Prolapse.

Uterosacral ligament suspension (USLS) is a common surgical treatment for pelvic organ prolapse (POP). However, the relatively high failure rate of up to 40% underscores a strong clinical need for complementary treatment strategies, such as biomaterial augmentation. Herein, the first hydrogel biomaterial augmentation of USLS in a recently established rat model is described using an injectable fibrous hydrogel composite. Supramolecularly-assembled hyaluronic acid (HA) hydrogel nanofibers encapsulated in a matrix metalloproteinase (MMP)-degradable HA hydrogel create an injectable scaffold showing excellent biocompatibility and hemocompatibility. The hydrogel can be successfully delivered and localized to the suture sites of the USLS procedure, where it gradually degrades over six weeks. In situ mechanical testing 24 weeks post-operative in the multiparous USLS rat model shows the ultimate load (load at failure) to be 1.70 ± 0.36 N for the intact uterosacral ligament (USL), 0.89 ± 0.28 N for the USLS repair, and 1.37 ± 0.31 N for the USLS + hydrogel (USLS+H) repair (n = 8). These results indicate that the hydrogel composite significantly improves load required for tissue failure compared to the standard USLS, even after the hydrogel degrades, and that this hydrogel-based approach can potentially reduce the high failure rate associated with USLS procedures.

User-defined, temporal presentation of bioactive molecules on hydrogel substrates using supramolecular coiled coil complexes.

The ability to spatiotemporally control the presentation of relevant biomolecules in synthetic culture systems has gained significant attention as researchers strive to recapitulate the endogenous extracellular matrix (ECM) in vitro. With the biochemical composition of the ECM constantly in flux, the development of platforms that allow for user-defined control of bioactivity is desired. Here, we reversibly conjugate bioactive molecules to hydrogel-based substrates through supramolecular coiled coil complexes that form between complementary peptides. Our system employs a thiolated peptide for tethering to hydrogel surfaces (T-peptide) through a spatially-controlled photomediated click reaction. The complementary association peptide (A-peptide), containing the bioactive domain, forms a heterodimeric coiled coil complex with the T-peptide. Addition of a disruptor peptide (D-peptide) engineered specifically to target the A-peptide outcompetes the T-peptide for binding, and removes the A-peptide and the attached bioactive motif from the scaffold. We use this platform to demonstrate spatiotemporal control of biomolecule presentation within hydrogel systems in a repeatable process that can be extended to adhesive motifs for cell culture. NIH 3T3 fibroblasts seeded on hyaluronic acid hydrogels and polyethylene glycol-based fibrous substrates supramolecularly functionalized with an RGD motif demonstrated significant cell spreading over their nonfunctionalized counterparts. Upon displacement of the RGD motif, fibroblasts occupied less area and clustured on the substrates. Taken together, this platform enables facile user-defined incorporation and removal of biomolecules in a repeatable process for controlled presentation of bioactivity in engineered culture systems.

Electrospun hydrogels for dynamic culture systems: advantages, progress, and opportunities.

The extracellular matrix (ECM) is a water-swollen, tissue-specific material environment in which biophysiochemical signals are organized and influence cell behaviors. Electrospun nanofibrous substrates have been pursued as platforms for tissue engineering and cell studies that recapitulate features of the native ECM, in particular its fibrous nature. In recent years, progress in the design of electrospun hydrogel systems has demonstrated that molecular design also enables unique studies of cellular behaviors. In comparison to the use of hydrophobic polymeric materials, electrospinning hydrophilic materials that crosslink to form hydrogels offer the potential to achieve the water-swollen, nanofibrous characteristics of endogenous ECM. Although electrospun hydrogels require an additional crosslinking step to stabilize the fibers (allowing fibers to swell with water instead of dissolving) in comparison to their hydrophobic counterparts, researchers have made significant advances in leveraging hydrogel chemistries to incorporate biochemical and dynamic functionalities within the fibers. Consequently, dynamic biophysical and biochemical properties can be engineered into hydrophilic nanofibers that would be difficult to engineer in hydrophobic systems without strategic and sometimes intensive post-processing techniques. This Review describes common methodologies to control biophysical and biochemical properties of both electrospun hydrophobic and hydrogel nanofibers, with an emphasis on highlighting recent progress using hydrogel nanofibers with engineered dynamic complexities to develop culture systems for the study of biological function, dysfunction, development, and regeneration.

Managing pulmonary embolism secondary to suppurative deep vein thrombophlebitis due to community-acquired Staphylococcus aureus in a resource-poor setting.

Deep vein thrombosis and pulmonary thromboembolism are rare and life threatening emergencies in children. We report an 11-year old female who presented with acute complaints of high grade fever, pain in the left thigh and inability to walk and breathlessness since 6 days. On physical examination, there was a diffuse tender swelling of the left thigh, tachypnea, tachycardia with hyperdynamic precordium and bilateral basal crepitations. Ultrasonography and venous doppler of lower limbs showed mild effusion of left hip joint and thrombus in the left common femoral vein and left external iliac vein suggesting a diagnosis of septic arthritis with thrombophlebitis. The tachypnea and tachycardia which was out of proportion to fever and crepitations on auscultation prompted suspicion of an embolic phenomenon. Radiograph of the chest revealed multiple wedge shaped opacities in the right middle zone and lower zone suggestive of pulmonary embolism and left lower zone consolidation. For corroboration, computed tomography pulmonary angiography and computed tomography of abdomen was performed which showed pulmonary thromboembolism and deep venous thrombosis extending up to infrarenal inferior vena cava. On further workup, magnetic resonance imaging of hips showed left femoral osteomyelitis and multiple intramuscular abscesses in the muscles around the hip joint. Blood culture grew methicillin resistant Staphylococcus aureus. Antibiotics were changed according to culture sensitivity and there was a dramatic response. After four weeks of anticoagulation and antibiotics the child became asymptomatic and thrombus resolved. Thus, it is crucial to consider methicillin resistant Staphylococcus aureus infection as an important infection when we encounter such a clinical scenario. This case report highlights an unusual and potentially life threatening presentation of a virulent strain of a common pathogen, which when diagnosed was completely amenable to treatment.

Female urethral stricture: a contemporary series.

PURPOSE: To report the etiology, presenting symptoms and outcomes of the different treatments performed in female patients with recurrent urethral stricture. MATERIALS AND METHODS: Twenty-six patients with refractory LUTS were diagnosed with a urethral stricture. The symptoms, the treatment performed and the outcomes were prospectively recorded. Sixteen patients were treated with a urethroplasty using a buccal mucosal graft (BMG) in 14 cases (54 %) and a vaginal flap in 2 (8 %). Urethral dilatation, optical urethrotomy and meatoplasty were performed in 8 (31 %), 1 (3.8 %) and 1 (3.8 %) patients, respectively. RESULTS: Strictures were idiopathic in 11 patients (42 %). Previous urethral instrumentation and traumatic vaginal delivery were the commonest causes of urethral stricture (42 and 15 %, respectively). The most frequent symptoms were reduced flow (93 %), detrusor overactivity (50 %) and UTIs (42 %). The stricture was cured in 93 % of patients treated with a BMG urethroplasty and in all the patients in which a vaginal flap urethroplasty was performed. In the same group, the improvement in urethral pain was observed in the 67 and the 88 % of patients were cured from recurrent UTIs. All the patients treated with urethral dilatation needed further dilatations; hence, the cure of the stricture was achieved in none of them. Improvement in urethral pain, UTIs and detrusor activity was not recorded in the latter group. CONCLUSION: Urethroplasty in its various forms has demonstrated in the present series the highest cure rate for the treatment of recurrent urethral stricture.

Differential antioxidative response of tolerant and sensitive maize (Zea mays L.) genotypes to drought stress at reproductive stage.

The role of oxidative stress management was evaluated in two maize (Zea mays L.) genotypes - Parkash (drought-resistant) and Paras (drought-sensitive), subjected to drought stress during reproductive stage. Alterations in their antioxidant pools - glutathione (GSH) and ascorbic acid (AsA) combined with activities of enzymes glutathione reductase (GR), ascorbate peroxidase (APX), peroxidase (POX) and catalase (CAT) involved in defense against oxidative stress and stress parameters, namely chlorophyll (Chl), hydrogen peroxide (H2O2) and malondialdehyde (MDA) were investigated in flag leaves from silk emergence till maturity. The drought caused transient increase in GR, APX, POX and CAT activities in drought-tolerant genotype (Parkash) which decreased at later stages with the extended period of drought stress. However, in Paras, drought stress caused decrease in activities of GR and CAT from initial period of stress till the end of experiment, except for POX which showed slight increase in activity. A significant increase in GSH content was observed in Parkash till 35 days after silking (DAS), whereas in Paras, GSH content remained lower than irrigated till maturity. Parkash which had higher AsA and Chl contents, also showed lower H2O2 and MDA levels than Paras under drought stress conditions. However, at the later stages, decline in antioxidant enzyme activities in Parkash due to severe drought stress led to enhanced membrane damage, as revealed by the accumulation of MDA. Our data indicated that significant activation of antioxidant system in Parkash might be responsible for its drought-tolerant behavior under drought stress and helped it to cope with the stress up to a definite period. Thus, the results indicate that antioxidant status and lipid peroxidation in flag leaves can be used as indices of drought tolerance in maize plants and also as potential biochemical targets for the crop improvement programmes to develop drought-tolerant cultivars.

In vivo RAF signal transduction as a potential biomarker for sorafenib efficacy in patients with neuroendocrine tumours.

BACKGROUND: Targeted therapies elicit anticancer activity by exerting pharmacodynamic effects on specific molecular targets. Currently, there is limited use of pharmacodynamic assessment to guide drug administration in the routine oncology setting. METHODS: We developed a phosphoshift (pShift) flow cytometry-based test that measures RAF signal transduction capacity in peripheral blood cells, and evaluated it in a phase II clinical trial of oral sorafenib plus low-dose cyclophosphamide in patients with advanced neuroendocrine tumours (NETs), in order to predict clinical course and/or guide individual dose-titration. RESULTS: Twenty-two patients were enrolled. Median progression-free survival (PFS) was 3 months (95% CI 2-10.7), and one patient had a partial response. PFS was longer among five patients who demonstrated an increase in pShift after 7 days of sorafenib compared with those who did not (14.9 months vs 2.8 months; P=0.047). However, pShift did not add value to toxicity-based dose-titration. CONCLUSION: The pharmacodynamic assessment of RAF transduction may identify selected patients with advanced NETs most likely to benefit from the combination of sorafenib plus cyclophosphamide. Further investigation of this test as a potential biomarker is warranted.

Malignant risk and surgical outcomes of presacral tailgut cysts.

BACKGROUND: Presacral tailgut cysts are uncommon and few data exist on the outcomes following surgery. METHODS: Patients undergoing tailgut cyst resection at the Mayo Clinic between 1985 and 2008 were analysed retrospectively. Demographic data, clinicopathological features, operative details, postoperative complications and recurrence were reviewed. RESULTS: Thirty-one patients were identified (28 women), with a median age of 52 years. Seventeen patients were symptomatic and 28 had a palpable mass on digital rectal examination. Median cyst diameter was 4.4 cm. Four patients had a fistula to the rectum. Complete cyst excision was achieved in all patients; eight underwent distal sacral resection or coccygectomy. Postoperative complications occurred in eight patients but without 30-day mortality. Malignant transformation was present in four patients: adenocarcinoma in three and carcinoid in one. The cyst recurred in one patient after surgery for a benign lesion. CONCLUSION: Presacral tailgut cysts should be removed due to the risk of malignant transformation.

Effects of calcitonin gene-related peptide on vascular resistance in rats: role of sex steroids.

It has been demonstrated in reflex-intact animals that the sensitivity to calcitonin gene-related peptide (CGRP) is increased during pregnancy and that this action is mediated by sex steroids but not by nitric oxide (NO). We assessed the effects of CGRP in the following groups of anesthetized ganglion-blocked rats: 1) pregnant, 2) ovariectomized, and 3) ovariectomized and treated with estradiol and progesterone. Changes in mean arterial pressure (MAP) were assessed after the administration of varying doses of CGRP. Decreases in MAP after CGRP administration were significantly greater in pregnant rats and ovariectomized rats administered sex steroids than in ovariectomized controls. The CGRP antagonist CGRP8-37 produced a pressor response of similar magnitude in both pregnant and ovariectomized rats. We also assessed the effects of CGRP and the modulating role of NO in the isolated uterine vascular bed preparation. CGRP reduced perfusion pressure to a greater degree in ovariectomized animals treated with sex steroids than in ovariectomized animals. This response was attenuated by pretreatment with an NO synthesis inhibitor. CGRP8-37 produced a similar increase in perfusion pressure in both groups. We conclude that 1) the increased vascular sensitivity observed during pregnancy or after treatment with sex steroids is in part mediated by NO, and 2) CGRP8-37 has a vasoconstrictor action of its own.

Acidosis and glucocorticoids induce branched-chain amino acid catabolism.

Chronic renal failure (CRF) is frequently complicated by malnutrition and wasting. The loss of lean body mass in CRF is the result of accelerated protein and amino acid degradation. Both appear to occur via acidosis-induced, glucocorticoid-dependent processes. In skeletal muscle, acidosis stimulates the activity of the rate-limiting enzyme in branched-chain amino acid metabolism, branched-brain ketoacid dehydrogenase (BCKAD). The activation of BCKAD in acidosis is likely to be glucocorticoid-dependent.

Early prediction of outcome following head injury in children: an assessment of the value of Glasgow Coma Scale score trend and abnormal plantar and pupillary light reflexes.

A retrospective study of 95 children less than 15 years of age with significant head injury was made to assess the value of Glasgow Coma Scale (GCS) score trend and plantar and pupillary light reflexes during the first 24 hours after injury, in predicting eventual outcome. GCS score trend or reflexes used alone were significantly correlated to outcome. There was also a statistically significant correlation when these parameters in combination were related to outcome. However, the clinical value of the combined use of GCS score trend and reflexes was only slightly greater than the use of GCS score trend alone.

Cardiovascular effects of nasotracheal intubation.

Intubation time, arterial pressure, heart rate and arterial oxygen saturation during nasotracheal intubation effected with the Macintosh laryngoscope blade were compared with those during orotracheal intubation. The 60 patients studied received a standardised general anaesthetic and were randomly allocated to one of two groups immediately before tracheal intubation. The mean nasal intubation time (33.2 seconds) was significantly greater than mean oral intubation time (14.8 seconds). The mean arterial pressure changes in the nasal group were significantly greater and more prolonged than in the oral group. The mean heart rate in the nasal group was significantly lower than in the oral group during the first minute after intubation, after which heart rates were similar. There were no significant differences between the two groups with regard to arterial oxygen saturation levels at any stage.

Dermatoglyphic profile in congenital cataracts.

Forty-five children with congenital cataract cases were studied for patterns and compared with age sex matched controls. The patients showed marked differences in different dermatoglyphic traits. The intra uterine aetiological groups i.e. rubella, hereditary and undetected aetiology, showed variations in mainline terminations. Rubella group showed increased angle atd.

Sister chromatid exchanges in congenital cataracts.

A total of 25 patients with bilateral congenital cataracts, from three aetiological groups i.e. rubella (6 patients) hereditary (6 patients) and undetected aetiology (13 patients) were studied for sister chromatid exchanges (SCE). SCEs were markedly raised in the rubella groups as compared with age sex matched controls. The other two groups also showed raised SCE, more so in hereditary group.

Genetic appraisal of congenital cataract.

A total of 45 congenital cataract cases were studied for chromosomal aberrations and dermatoglyphic patterns. Whereas parents showed no marked differences, patients showed marked differences in different dermatoglyphic traits as compared to age-sex matched controls. Out of all the patients Rubella, hereditary and undetected actiology groups showed variations differently, SCE were seen in all cataracts irrespective of their aetiology as compared to controls.