A 500 kV, 10 kA, 40 ns coaxial Marx generator pulser for cable fed flash x-ray system

Flash x-ray (FXR) systems are used for dynamic radiography. Depending on the speed of the object, these systems typically require a very short pulse duration (∼25 ns) for image acquisition without motion blur. The conventional Marx generators with zigzag discharge paths result in higher inductance; hence, they do not meet the requirement of shorter pulse duration (30-40 ns) and low impedance (40-60 Ω) simultaneously. A coaxial Marx generator has been designed and developed, which is capable of generating 500 kV peak voltages and 10 kA peak current within a 40 ns pulse duration. The CST simulation of the coaxial Marx generator has been carried out to validate the design parameters. The FXR electron beam diode is powered by this Marx generator. Experiments were carried out to measure the x-ray parameters like pulse width, source size, x-ray energy spectrum, penetration depth, and cone angle. The maximum measured x-ray dose was 62 mR at 1 m distance from the source window. The x-ray radiograph demonstrates a penetration depth of 32 mm in steel kept at 2.5 m distance from the source for 500 kV diode voltages.

O079 Predictive value for elevated platelet-derived SGPVI in venous in-stent stenosis in patients with post-thrombotic syndrome

Introduction

In-stent stenosis following intervention for post-thrombotic syndrome (PTS) occurs in ∼30% of cases, despite therapeutic anticoagulation. Our aim was to investigate whether platelets are involved.

Methods

Blood was taken from case-matched patients before and after venous stenting. Flow-cytometry was used to assess platelet activation (P-selectin and/or phosphatidylserine exposure) while= functional activity was measured by plate-based aggregation and through a flow-cell model of thrombus formation. Soluble glycoprotein VI (sGPVI) was measured in plasma. Patients with in-stent stenosis requiring reintervention (>50% diameter reduction) were compared with those who did not.

Results

Forty-five patients were recruited (median age: 43yrs (33–55yrs); 65% female), and 19/45 (42%) required reintervention (median time: 3wks (1day-3mths)). There was no difference in platelet activation or reactivity after stenting, but P-selectin exposure pre-stent was significantly higher in patients who developed in-stent stenosis (2.7%±0.4 vs 1.7%±0.2; P<0.05). Pre-stent sGPVI levels were increased in patients who developed in-stent stenosis (18.9±3.6ng/mL vs. 7.4±0.9ng/mL; P<0.01). Platelet reactivity to collagen-related peptide, a GPVI-specific platelet agonist, was reduced in patients who developed in-stent stenosis (logEC50 = -6.5M±0.3 vs -7.2M±0.2; P<0.05; n=33). Pre-stent platelet accumulation (26.6AU±0.5 vs 19.0AU±8.1; P=0.04) was significantly increased in PTS patients compared with healthy controls.

Conclusion

Venous stenting does not activate platelets, but patients who developed in-stent stenosis exhibited greater levels of pre-stent platelet activation, greater loss of platelet surface GPVI in the form of sGPVI and reduction in reactivity to GPVI activation. sGPVI may have potential to risk stratify patients undergoing venous stenting and predict who requires closer surveillance.

Take-home message

Soluble GPVI may have potential to risk-stratify patients undergoing deep venous reconstruction and predict who requires closer surveillance.

Restoring Carboxylates on Highly Modified Alginates Improves Gelation, Tissue Retention and Systemic Capture

Alginate hydrogels are gaining traction for use in drug delivery, regenerative medicine, and as tissue engineered scaffolds due to their physiological gelation conditions, high tissue biocompatibility, and wide chemical versatility. Traditionally, alginate is decorated at the carboxyl group to carry drug payloads, peptides, or proteins. While low degrees of substitution do not cause noticeable mechanical changes, high degrees of substitution can cause significant losses to alginate properties including complete loss of calcium cross-linking. While most modifications used to decorate alginate deplete the carboxyl groups, we propose that alginate modifications that replenish the carboxyl groups could overcome the loss in gel integrity and mechanics. In this report, we demonstrate that restoring carboxyl groups during functionalization maintains calcium cross-links as well as hydrogel shear-thinning and self-healing properties. In addition, we demonstrate that alginate hydrogels modified to a high degree with azide modifications that restore the carboxyl groups have improved tissue retention at intramuscular injection sites and capture blood-circulating cyclooctynes better than alginate hydrogels modified with azide modifications that deplete the carboxyl groups. Taken together, alginate modifications that restore carboxyl groups could significantly improve alginate hydrogel mechanics for clinical applications. STATEMENT OF SIGNIFICANCE: Chemical modification of hydrogels provides a powerful tool to regulate cellular adhesion, immune response, and biocompatibility with local tissues. Alginate, due to its biocompatibility and easy chemical modification, is being explored for tissue engineering and drug delivery. Unfortunately, modifying alginate to a high degree of substitution consumes carboxyl group, which are necessary for ionic gelation, leading to poor hydrogel crosslinking. We introduce alginate modifications that restore the alginate's carboxyl groups. We demonstrate that modifications that reintroduce carboxyl groups restore gelation and improve gel mechanics and tissue retention. In addition to contributing to a basic science understanding of hydrogel properties, we anticipate our approach will be useful to create tissue engineered scaffolds and drug delivery platforms.

Use of the Coupler Microanastomotic Device for the Treatment of a Distal Posterior Inferior Cerebellar Artery Aneurysm Via Excision and End-to-End Anastomosis—A Case Report

BACKGROUND AND IMPORTANCE

The Coupler microanastomotic device (Medical Companies Alliance, Birmingham, Alabama) aims at facilitating safe and efficient end-to-end reconstruction of the native vessel ends following resection of intracranial aneurysms.

CLINICAL PRESENTATION

We report the first case of the Coupler device used to treat a ruptured posterior inferior cerebellar artery (PICA) aneurysm. Following aneurysmal trapping and excision, the native parent vessel ends were connected in an end-to-end fashion.

CONCLUSION

The microanastomotic Coupler device is an acceptable option for end-to-end anastomosis and was successfully applied in the management of a ruptured fusiform PICA aneurysm.

Outcomes following two-stage surgical approaches in the treatment of pediatric ulcerative colitis

INTRODUCTION

Surgery for the treatment of ulcerative colitis (UC) can be performed in one-, two-, or three-stage procedures [1]. The more traditional approach is a total proctocolectomy and creation of an ileo pouch-anal anastomosis and diverting stoma at the initial operation, followed by ileostomy closure several weeks later (TIPPA) [1]. An alternative is an initial subtotal colectomy and end ileostomy [2]. In this alternative approach (NIPAA), a completion proctectomy and definitive ileo pouch-anal anastomosis can be performed without a diverting stoma. We hypothesize that functional outcomes following a NIPAA approach when performed in children, in our experience, are likely similar or improved when compared to those treated by TIPAA.

METHODS

After IRB approval, a review of patients who underwent a two-stage Laparoscopic IPAA from 2004 to 2017 occurred. Data included demographics, diagnosis, surgical intervention time to full diet, level of continence, use of antidiarrheals and complications.

RESULTS

N = 41 (NIPAA = 14, TIPAA = 27). After establishment of bowel continuity, no significant differences in appetite recovery, continence, or complications were noted. The number of antidiarrheals prescribed were significantly higher in the TIPAA group (p = 0.01). Thirteen patients (31.7%) had pouchitis: 4 NIPAA and 9 TIPAA (p = NS). Of the 41 patients, 11 required subsequent surgery; 2 patients (18.2%) received NIPAA and 9 (81.8%) received TIPAA (p = 0.20). Two TIPAA patients received a diverting ileostomy owing to chronic anal pain and failure to achieve continence.

CONCLUSION

This study suggests children with medically refractory UC treated by NIPAA or TIPAA have similar outcomes. Minimal differences in overall outcome were noted following either approach. However, NIPAA may reduce reliance on antidiarrheals to achieve satisfactory defecation outcomes.

LEVEL OF EVIDENCE

III Retrospective comparative study.

PrEP Eligibility and Interest Among Clinic- and Community-Recruited Young Black Women in Atlanta, Georgia, USA

BACKGROUND

Atlanta has been identified as an HIV "hot spot" for Black women and ranks 5th in the US with new infections. Yet little is known about PrEP eligibility or interest among young Black women in Atlanta.

METHODS

A convenience sample of 1,261 Black women (ages 14-24 years) were recruited from two settings: community venues and sexual health clinics. They provided self-reported sexual behavior data and specimens for laboratory testing for chlamydia (CT) and gonorrhea (GC) infections. For each woman, the number of key self-reported behavioral HIV risk factors was calculated (0-6 factors for the clinic sample, 0-3 factors for the community sample). A single item assessed PrEP interest in the community sample only.

RESULTS

Bacterial STI positivity, an indicator for PrEP eligibility, was 20.5% (17.1% CT, 6.3% GC) and 20.9% (18.8% CT, 5.2% GC) for the clinic and community samples, respectively. Of the 144 STI positive women from the clinic sample, 20.1% reported no behavioral risk indicators and 47.2% reported > 2 behavioral indicators. Of the 117 STI positive women from the community sample, 21.4% reported no behavioral risk indicators. 60.7% of the community sample reported they would be likely or very likely to use PrEP if available.

CONCLUSION

Young Black women in Atlanta, whether sampled from community or sexual health settings, are at substantial risk for HIV infection and meet several PrEP eligibility criteria. Scaling up PrEP among women in Atlanta could have significant implications for HIV in this high burden region.

Left Internal Carotid Artery Arising from the Right Cavernous Internal Carotid Artery: A Case Report

Anatomical variations involving the internal carotid artery are uncommon. Herein, we present a very rare origin of the internal carotid artery. An adult female presented to the emergency department after falling. Imaging revealed that the left internal carotid artery arose from the contralateral cavernous segment of the internal carotid artery. Such a variation should be kept in mind by radiologists and surgeons who interpret and operate in this area, respectively.

Development of cable fed flash X-ray (FXR) system

Flash X-ray sources driven by pulsed power find applications in industrial radiography, and a portable X-ray source is ideal where the radiography needs to be taken at the test site. A compact and portable flash X-ray (FXR) system based on a Marx generator has been developed with the high voltage fed to the FXR tube via a cable feed-through arrangement. Hard bremsstrahlung X-rays of few tens of nanosecond duration are generated by impinging intense electron beams on an anode target of high Z material. An industrial X-ray source is developed with source size as low as 1 mm. The system can be operated from 150 kV to 450 kV peak voltages and a dose of 10 mR has been measured at 1 m distance from the source window. The modeling of the FXR source has been carried out using particle-in-cell and Monte Carlo simulations for the electron beam dynamics and X-ray generation, respectively. The angular dose profile of X-ray has been measured and compared with the simulation.

Association of the Extent of Resection With Survival in Glioblastoma: A Systematic Review and Meta-analysis

Importance

Glioblastoma multiforme (GBM) remains almost invariably fatal despite optimal surgical and medical therapy. The association between the extent of tumor resection (EOR) and outcome remains undefined, notwithstanding many relevant studies.

Objective

To determine whether greater EOR is associated with improved 1- and 2-year overall survival and 6-month and 1-year progression-free survival in patients with GBM.

Data Sources

Pubmed, CINAHL, and Web of Science (January 1, 1966, to December 1, 2015) were systematically reviewed with librarian guidance. Additional articles were included after consultation with experts and evaluation of bibliographies. Articles were collected from January 15 to December 1, 2015.

Study Selection

Studies of adult patients with newly diagnosed supratentorial GBM comparing various EOR and presenting objective overall or progression-free survival data were included. Pediatric studies were excluded.

Data Extraction and Synthesis

Data were extracted from the text of articles or the Kaplan-Meier curves independently by investigators who were blinded to each other's results. Data were analyzed to assess mortality after gross total resection (GTR), subtotal resection (STR), and biopsy. The body of evidence was evaluated according to Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria and PRISMA guidelines.

Main Outcome and Measures

Relative risk (RR) for mortality at 1 and 2 years and progression at 6 months and 1 year.

Results

The search produced 37 studies suitable for inclusion (41 117 unique patients). The meta-analysis revealed decreased mortality for GTR compared with STR at 1 year (RR, 0.62; 95% CI, 0.56-0.69; P < .001; number needed to treat [NNT], 9) and 2 years (RR, 0.84; 95% CI, 0.79-0.89; P < .001; NNT, 17). The 1-year risk for mortality for STR compared with biopsy was reduced significantly (RR, 0.85; 95% CI, 0.80-0.91; P < .001). The risk for mortality was similarly decreased for any resection compared with biopsy at 1 year (RR, 0.77; 95% CI, 0.71-0.84; P < .001; NNT, 21) and 2 years (RR, 0.94; 95% CI, 0.89-1.00; P = .04; NNT, 593). The likelihood of disease progression was decreased with GTR compared with STR at 6 months (RR, 0.72; 95% CI, 0.48-1.09; P = .12; NNT, 14) and 1 year (RR, 0.66; 95% CI, 0.43-0.99; P < .001; NNT, 26). The quality of the body of evidence by the GRADE criteria was moderate to low.

Conclusion and Relevance

This analysis represents the largest systematic review and only quantitative systematic review to date performed on this subject. Compared with STR, GTR substantially improves overall and progression-free survival, but the quality of the supporting evidence is moderate to low.

Systematic review: outcomes and post-operative complications following colectomy for ulcerative colitis

BACKGROUND

Colectomy for ulcerative colitis is associated with short- and long-term complications. Estimates of the frequency of such complications are variable and may have changed since the introduction of biological therapy. Understanding the true burden of surgical complications is important to clinicians in assessing risks and benefits of colectomy vs. continued medical therapy.

AIM

To ascertain the outcomes of colectomy and ileal pouch surgery in patients with ulcerative colitis in the biologics era.

METHODS

Embase, MEDLINE and The Cochrane Library were searched for studies (2002-2015) reporting the outcomes of colorectal procedures (total and subtotal colectomy, IPAA with J-, S-, W-pouch) in adults with ulcerative colitis. Conferences proceedings (2011-2015) were hand-searched.

RESULTS

We identified 28 studies (20,801 patients) reporting outcomes from procedures conducted from 2002-2015. Early complications (≤30 days post-operatively), reported in 10 studies, occurred in 9-65% of patients with ulcerative colitis; late complications (>30 days post-operatively) occurred in 17-55% of patients. Most frequent short-term complications: infectious complications and ileus (mean incidence 20% and 18%). Most frequent long-term complications: pouchitis, faecal incontinence and small bowel obstruction (mean incidence 29%, 21% and 17%). Rates of early infection and late pouch failure decreased from 22% and 13% in 2002-2009 to 11% and 2% in 2010-2015. The mean incidence of post-operative mortality was 1.0% across 11 studies.

CONCLUSIONS

Early and late complications arise in about one-third of patients undergoing surgery for ulcerative colitis. While colorectal surgical procedures are recommended for a specific group of patients, the post-operative complications associated with these procedures should not be underestimated.

Abstract TMP108: Absence of Cortical Microvessel Spasm During Large Vessel Spasm Following Experimental Subarachnoid Hemorrhage

Introduction: A significant portion of the morbidity and mortality following aneurysmal subarachnoid hemorrhage (SAH) is due to delayed ischemic neurological deficits (DIND). Although large vessel vasospasm has been implicated as a cause of DIND, the presence of such spasm is not always correlated with DIND. In the present experiment we examined the cortical microvasculature in awake mice after SAH in an experimental model typically associated with large vessel vasospasm.

Methods: Twenty adult mice underwent cisterna magna (CM) injection of 60ul syngenic donor blood or artificial cerebrospinal fluid (aCSF). The mice were perfused at 72 hours, and Circle of Willis (COW) vessel diameters were measured. In a separate experiment, polished and reinforced thinned skull cranial windows were created in 10 mice that then underwent CM blood or aCSF injection. Cortical microvessels were measured in living, awake mice in the postoperative vasospasm period using two photon laser scanning microscopy.

Results: A pairwise comparison of COW vessels revealed a statistically significant difference in vessel diameter between the experimental and control groups at each of the sites measured (ACA, P=0.0012; MCA, P=0.0259; Pcom, P=0.0053). In the second experiment, there were no significant differences in cortical microvessel diameter between the experimental and control groups.

Conclusions: This study represents the first report of in vivo imaging of cortical microvessels during large vessel spasm following SAH. In a CM injection SAH model, we observed significant large vessel spasm but no cortical microvessel spasm. These results may have important implications for understanding the mechanisms of DIND.

Systematic review: the financial burden of surgical complications in patients with ulcerative colitis

BACKGROUND

Patients undergoing colectomy for ulcerative colitis (UC) may experience complications associated with reduced quality of life (QoL), and maybe a considerable economic burden to healthcare systems. Appreciation of these burdens is important to evaluate the cost effectiveness of newer interventions for UC vs. colectomy.

AIM

To identify data representing resource utilisation or costs of complications arising from colorectal procedures in patients with UC, and data representing patient QoL, as reported by health state utility values (HSUVs).

METHODS

Embase, MEDLINE and The Cochrane Library were searched for studies (1995-2014) reporting resource use/costs of surgical complications, and HSUVs data in adult patients with UC, undergoing colorectal procedures. Conference proceedings (January 2011-January 2014) were hand-searched.

RESULTS

Twelve studies reported resource use/costs, and three reported HSUVs data in patients with UC experiencing surgical complications. Additional mean costs of postoperative complications ranged from $18 650/patient with complications at a 6-month follow-up (46% incidence) to $34 714/patient with complications over a 5-year period (49% incidence). Pouchitis, pouch failure and small bowel obstruction carried the greatest burden. Marked reductions in HSUVs were observed for patients with UC experiencing surgical complications, vs. patients with UC in a remission state.

CONCLUSIONS

There is a paucity of well reported studies on resource use/cost, and QoL burden of surgical complications in patients with UC. However, surgical complications represent a substantial burden both in terms of cost and of quality of life, with reoperations, physician fees, additional in-patient hospital stays and infertility treatment being the main cost drivers.

Onyx-HD 500 Embolization of a Traumatic Internal Carotid Artery Pseudoaneurysm after Transsphenoidal Surgery

BACKGROUND AND PURPOSE

Traumatic intracranial pseudoaneurysms present a challenge for treatment. Traditionally these lesions have required a deconstructive approach consisting of vessel sacrifice since their fragile nature often makes direct microsurgical repair or coil embolization hazardous. As a high-viscosity liquid embolic agent that results in immediate, vessel sparing aneurysm occlusion, Onyx-HD 500 represents a uniquely efficacious tool for this clinical situation.

CASE SUMMARY

We report the case of a 56-year-old right-handed gentleman who suffered a vascular injury to the ICA during revision transsphenoidal surgery for a recurrent pituitary macroadenoma. The patient was initially treated with nasal packing, but after recurrent episodes of epistaxis and a CT angiogram demonstrating a large traumatic ICA pseudoaneurysm, the patient was referred for invasive treatment. Given the presumed fragility of the lesion, embolization with Onyx-HD 500 was chosen in order to safely achieve immediate aneurysm occlusion without the need for vessel sacrifice. After an early recurrence due to incomplete initial embolization, the patient went on to complete occlusion without further hemorrhage.

CONCLUSION

This case illustrates the utility of a high-viscosity liquid embolic agent in providing immediate protection from rehemorrhage by occluding a large ruptured pseudoaneurysm of the proximal intracranial ICA, while sparing the parent artery.

Editor's choice--Angulation of the C-arm during complex endovascular aortic procedures increases radiation exposure to the head

OBJECTIVES/BACKGROUND

The increased complexity of endovascular aortic repair necessitates longer procedural time and higher radiation exposure to the operator, particularly to exposed body parts. The aims were to measure directly exposure to radiation of the bodies and heads of the operating team during endovascular repair of thoracoabdominal aortic aneurysms (TAAA), and to identify factors that may increase exposure.

METHODS

This was a single-centre prospective study. Between October 2013 and July 2014, consecutive elective branched and fenestrated TAAA repairs performed in a hybrid operating room were studied. Electronic dosimeters were used to measure directly radiation exposure to the primary (PO) and assistant (AO) operator in three different areas (under-lead, over-lead, and head). Fluoroscopy and digital subtraction angiography (DSA) acquisition times, C-arm angulation, and PO/AO height were recorded.

RESULTS

Seventeen cases were analysed (Crawford II-IV), with a median operating time of 280 minutes (interquartile range 200-330 minutes). Median age was 76 years (range 71-81 years); median body mass index was 28 kg/m(2) (25-32 kg/m(2)). Stent-grafts incorporated branches only, fenestrations only, or a mixture of branches and fenestrations. A total of 21 branches and 38 fenestrations were cannulated and stented. Head dose was significantly higher in the PO compared with the AO (median 54 μSv [range 24-130 μSv] vs. 15 μSv [range 7-43 μSv], respectively; p = .022), as was over-lead body dose (median 80 μSv [range 37-163 μSv] vs. 32 μSv [range 6-48 μSv], respectively; p = .003). Corresponding under-lead doses were similar between operators (median 4 μSv [range 1-17 μSv] vs. 1 μSv [range 1-3 μSv], respectively; p = .222). Primary operator height, DSA acquisition time in left anterior oblique (LAO) position, and degrees of LAO angulation were independent predictors of PO head dose (p < .05).

CONCLUSIONS

The head is an unprotected area receiving a significant radiation dose during complex endovascular aortic repair. The deleterious effects of exposure to this area are not fully understood. Vascular interventionalists should be cognisant of head exposure increasing with C-arm angulation, and limit this manoeuvre.

Angiogenic cell therapy for critical limb ischemia: an update on concepts and trials

Therapeutic neovascularization is a novel approach used to salvage critically ischemic limbs that are not amenable to conventional treatments. Initial efforts were based on single injections of angiogenic factors but there is now a realization that delivering angiogenic cells is more likely to achieve effective revascularization. Clinical studies to date have mostly used mixtures of mononuclear cells harvested from the bone marrow or peripheral blood. The modest results achieved with these cells, only a proportion of which are angiogenic, has stimulated a search for more potent cell types. Preclinical studies have identified several candidates, including adipose derived, embryonic and induced pluripotent stem cells. This review provides an update on the current status of angiogenic cell therapy for the ischemic limb and outlines efforts aimed at enhancing the clinical efficacy of treatments.

Detection of circulating tumor cells in the cerebrospinal fluid of a patient with a solitary metastasis from breast cancer: A case report

Brain lesions identified following the diagnosis and eradication of primary cancers are often ambiguous in origin, existing as a solitary metastasis or an independent primary brain tumor. The brain is a relatively common site of metastasis with breast cancer, although determining whether metastases have originated from the breast or brain is often not possible without invasive biopsies. In the current case report, a patient presented with a brain lesion identified by radiography and was without systemic disease. The patient had previously exhibited a complete response to chemotherapy and surgery for a poorly differentiated invasive ductal carcinoma. The origin of the brain lesion could not be determined by magnetic resonance imaging, giving rise to a diagnostic dilemma with diverging treatment options. We previously reported a method to isolate and enumerate tumor cells of epithelial origin in the cerebrospinal fluid (CSF). CSF tumor cell analysis of the patient revealed massive CSF tumor cell burden of epithelial origin, indicating that the brain lesion was likely of breast origin. The current case report highlights the use of CSF tumor cell detection as a differential diagnostic tool, in addition to its previously demonstrated use as a marker of disease burden and therapeutic response.

Experimental investigations of argon spark gap recovery times by developing a high voltage double pulse generator

The voltage recovery in a spark gap for repetitive switching has been a long research interest. A two-pulse technique is used to determine the voltage recovery times of gas spark gap switch with argon gas. First pulse is applied to the spark gap to over-volt the gap and initiate the breakdown and second pulse is used to determine the recovery voltage of the gap. A pulse transformer based double pulse generator capable of generating 40 kV peak pulses with rise time of 300 ns and 1.5 μs FWHM and with a delay of 10 μs-1 s was developed. A matrix transformer topology is used to get fast rise times by reducing L(l)C(d) product in the circuit. Recovery Experiments have been conducted for 2 mm, 3 mm, and 4 mm gap length with 0-2 bars pressure for argon gas. Electrodes of a sparkgap chamber are of rogowsky profile type, made up of stainless steel material, and thickness of 15 mm are used in the recovery study. The variation in the distance and pressure effects the recovery rate of the spark gap. An intermediate plateu is observed in the spark gap recovery curves. Recovery time decreases with increase in pressure and shorter gaps in length are recovering faster than longer gaps.

Dual inactivation of Akt and ERK by TIC10 signals Foxo3a nuclear translocation, TRAIL gene induction, and potent antitumor effects

Recombinant tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an antitumor protein that is in clinical trials as a potential anticancer therapy but suffers from drug properties that may limit efficacy such as short serum half-life, stability, cost, and biodistribution, particularly with respect to the brain. To overcome such limitations, we identified TRAIL-inducing compound 10 (TIC10), a potent, orally active, and stable small molecule that transcriptionally induces TRAIL in a p53-independent manner and crosses the blood-brain barrier. TIC10 induces a sustained up-regulation of TRAIL in tumors and normal cells that may contribute to the demonstrable antitumor activity of TIC10. TIC10 inactivates kinases Akt and extracellular signal-regulated kinase (ERK), leading to the translocation of Foxo3a into the nucleus, where it binds to the TRAIL promoter to up-regulate gene transcription. TIC10 is an efficacious antitumor therapeutic agent that acts on tumor cells and their microenvironment to enhance the concentrations of the endogenous tumor suppressor TRAIL.

Effects of spray drying conditions on the physicochemical properties of the Tramadol-Hcl microparticles containing Eudragit(®) RS and RL

The preparation of Tramadol-HCL spray-dried microspheres can be affected by the long drug recrystallization time. Polymer type and drug–polymer ratio as well as manufacturing parameters affect the preparation. The purpose of this work was to evaluate the possibility to obtain tramadol spray-dried microspheres using the Eudragit^® RS and RL; the influence of the spray-drying parameters on morphology, dimension, and physical stability of microspheres was studied. The effects of matrix composition on microparticle properties were characterized by Laser Light scattering, differential scanning calorimetry (DSC), X-ray diffraction study, FT-infrared and UV-visible spectroscopy. The spray-dried microparticles were evaluated in terms of shape (SEM), size distribution (Laser light scattering method), production yield, drug content, initial drug loding and encapsulation efficiency. The results of X-ray diffraction and thermal analysis reveals the conversion of crystalline drug to amorphous. FTIR analysis confirmed the absence of any drug polymer interaction. The results indicated that the entrapment efficiency (EE), and product yield were depended on polymeric composition and polymeric ratios of the microspheres prepared. Tramadol microspheres based on Eudragit^® blend can be prepared by spray-drying and the nebulization parameters do not influence significantly on particle properties.

Identification and enumeration of circulating tumor cells in the cerebrospinal fluid of breast cancer patients with central nervous system metastases

The number of circulating tumor cells (CTCs) in the peripheral blood of metastatic breast cancer patients is now an established prognostic marker. While the central nervous system is a common site of metastasis in breast cancer, the standard marker for disease progression in this setting is cerebrospinal fluid (CSF) cytology. However, the significance of CSF cytology is unclear, requires large sample size, is insensitive and subjective, and sometimes yields equivocal results. Here, we report the detection of breast cancer cells in CSF using molecular markers by adapting the CellSearch system (Veridex). We used this platform to isolate and enumerate breast cancer cells in CSF of breast cancer patients with central nervous system (CNS) metastases. The number of CSF tumor cells correlated with tumor response to chemotherapy and were dynamically associated with disease burden. This CSF tumor cell detection method provides a semi-automated molecular analysis that vastly improves the sensitivity, reliability, objectivity, and accuracy of detecting CSF tumor cells compared to CSF cytology. CSF tumor cells may serve as a marker of disease progression and early-stage brain metastasis in breast cancer and potentiate further molecular analysis to elucidate the biology and significance of tumor cells in the CSF.

Cataract surgery after retinal surgery

Many patients require surgery for cataract after retinal surgery. When evaluating patients preoperatively, the surgeon should pay careful attention to the assessment of visual function and potential acuity, and to the slit lamp examination of the lens, posterior capsule, anterior cortical vitreous, and zonules. The surgeon's technique must account for increased nuclear sclerosis, intraoperative miosis, a characteristically longer axial length, and fluctuations in anterior chamber depth from movement of the iris-lens diaphragm. Posterior capsule plaques are not unusual. Posterior capsule opacification is the most frequent late complication. Visual outcomes are usually good except when limited by pre-existing macular pathology. Vision-threatening complications of cataract surgery are unusual.

Bilateral lateral rectus recession for consecutive exotropia

INTRODUCTION

Treatment of consecutive exotropia after bilateral medial rectus recessions has been rarely studied. Though several series have reported results of medial rectus advancement, none has described results of lateral rectus recessions.

METHODS

We reviewed our results in 31 patients who underwent bilateral lateral rectus recessions for consecutive exotropia after bilateral medial rectus recessions. Mean follow-up was 30 months (range, 1-140 months) after the exotropia repair.

RESULTS

At last follow-up, 20 of 31 patients (65%) had deviations of less than or equal to 10 PD. Limitation of adduction was not apparent.

DISCUSSION

Cooper's dictum states that lateral rectus recession should be performed instead of medial rectus advancement. Our results suggest that this approach is generally successful. The outcome after exotropia repair in consecutive deviations is comparable to that after repair of primary exotropia.

Cytogenetics and cancer

Techniques based on fluorescence in situ hybridization (FISH) have bridged the gap between molecular genetics and conventional cytogenetics. Since its introduction in the late 1980s, advanced FISH-based methods have greatly enhanced the cytogenetic analysis of hematopoietic and solid tumors and are rapidly gaining ground in clinical cytogenetic diagnostics. As interest in FISH technologies has grown, it has inspired an era of new FISH-based technologies such as multiplex FISH, spectral karyotyping, and comparative genomic hybridization. In this review, the focus is on the impact of these technologies in the field of cancer genetics.

Evaluation of an unused 1952 Ridley intraocular lens

PURPOSE

To evaluate an unused 1952 historic Ridley intraocular lens (IOL) brought to Bombay, India, in 1952 from an Oxford Ophthalmologic Conference in England and given to 1 of the authors during his residency.

SETTING

Alcon Laboratories, Fort Worth, Texas, USA.

METHODS

The Ridley IOL was evaluated at Alcon Laboratories, Inc., using the established procedures of its Intraocular R&D Laboratories. Various optical and physical aspects of the Ridley lens were evaluated including (1) dimensions, (2) weight, (3) power, (4) resolution efficiency and modulation transfer function (MTF), (5) surface sphericity by interferometry, (6) ultraviolet (UV)-visible transmission characteristic, (7) attenuated total reflectance (ATR)-Fourier transform infrared reflectance spectrum, and (8) cosmetics by visual inspection using light microscopy.

RESULTS

This 8.5 mm diameter, 2.4 mm thick, 23 diopter biconvex IOL weighed 108 mg. The ATR spectrum, UV-visible transmission, and refractive index confirmed its poly-(methyl methacrylate) material. The 0.56 MTF value at 100 line pairs/mm, per the International Standards Organization--IOL Optics Standard, and 93% resolution efficiency in water, per the American National Standard Institute IOL Optics Standard, revealed the IOL's excellent optics. This was confirmed by 0.278 wave root mean square surface figure as measured by Zygo interferometer using a 633 nm wavelength. Visual inspection revealed rough edges with sharp corners and some surface scratches. Early clinical experience with Ridley IOLs in Bombay, India, is briefly given.

CONCLUSION

The Ridley IOL had excellent optical quality, meeting the requirements of current IOL optics standards. The selection of its dimensions was guided by the human crystalline lens, and the Ridley IOL was half as bulky. Although its clinical results were mixed, successful cases inspired subsequent improvements, leading to modern, highly satisfactory IOLs. This IOL represented a revolutionary innovation in ophthalmology.

Overexpression of EMS1/cortactin in NIH3T3 fibroblasts causes increased cell motility and invasion in vitro

Cortactin, a p80/85 protein first identified as a src kinase substrate, is thought to be involved in the signaling pathway of mitogenic receptors and adhesion molecules mediating cytoskeletal reorganization. The cortactin gene, EMS1, maps to chromosome 11q13, a region amplified in head and neck squamous cell carcinomas (HNSCC) and breast cancer, which display lymph node metastasis and an unfavorable clinical outcome. To further address the role of cortactin in the malignant phenotype of cells, we stably overexpressed cortactin in NIH3T3 fibroblasts and evaluated the effects of elevated cortactin on cellular proliferation, motility and invasiveness. Cortactin overexpressing cells did not display any striking morphological changes, nor any significant differences in cell proliferation or saturation density as compared to control NIH3T3 cells. Furthermore, the cortactin overexpressing cells were anchorage dependent for growth. Interestingly, cortactin overexpressing cells were more motile and invasive in modified Boyden chamber assays. These results suggest that overexpression of cortactin may play a role in tumor progression by influencing tumor cell migration and invasion.

Determining the imaging quality of intraocular lenses

PURPOSE

To validate the proposed optical requirements of a draft international standard for intraocular lenses (IOLs).

SETTING

Eight optical testing laboratories in the United States, Germany, Japan, and The Netherlands.

METHODS

The testing laboratories performed modulation transfer function (MTF) tests on various IOLs using a model eye and visual resolution tests in air. Each laboratory performed duplicate measurements on a set of 43 lenses that was circulated among the testing laboratories.

RESULTS

The interlaboratory tests showed that the MTF measurements using a model eye had better repeatability and reproducibility than the more common industry practice of resolution testing in air with parallel light and the United States Air Force three-bar target. However, the two methods correlated well. The commonly applied criterion that an IOL resolve in air at least 60% of the Rayleigh cutoff spatial frequency corresponded to a minimum requirement of 0.43 MTF units at 100 mm-1 in a model eye.

CONCLUSIONS

Either criterion may be applied in accordance with a proposed international standard for IOLs. The model eye method can be applied over a broader range of dioptric powers and is relevant for materials that interact with aqueous. Both tests appear to have a greater ability to detect unwanted surface aberrations than resolution testing of IOLs in a water cell using parallel light, a method described in the current American National Standards Institute standard.

In vitro adherence of Pseudomonas aeruginosa to four intraocular lenses

PURPOSE

To compare the relative degrees of adherence of a clinical strain of Pseudomonas aeruginosa to the optic material of four intraocular lenses (IOLs).

SETTING

Center for Applied and Environmental Microbiology, Georgia State University, Atlanta, Georgia, USA.

METHODS

Intraocular lens optics made of poly(methyl methacrylate) (PMMA), AcrySof-acrylic, and silicone were included in this study. The IOLs were incubated in a minimal medium with cells of P. aeruginosa for 2 hours and 18 hours. Cells in the 2 hour experiment were prelabeled with 3H-leucine; those in the 18 hour experiments were postlabeled. After rinsing the IOLs to remove loosely adherent cells, we determined the number of cells adhered to coded lenses from calibration curves of disintegrations per minute versus cells per square millimeter. Additional lenses were incubated with P. aeruginosa and examined with scanning electron microscopy.

RESULTS

The adherence of P. aeruginosa in order of increasing magnitude was AcrySof-acrylic < PMMA < silicone 1 < silicone 2. The differences between all groups were statistically significant. The scanning electron microscopy observations were in general agreement with the radiolabel studies.

CONCLUSIONS

The AcrySof-acrylic IOL was less susceptible to primary adherence and 18 hour biofilm formation by P. aeruginosa than the PMMA and silicone IOLs, indicating that this material reduced pseudomonad adherence and the risk of endophthalmitis following cataract surgery.

Accuracy in determining intraocular lens dioptric power assessed by interlaboratory tests

PURPOSE

To describe a testing program conducted by a standards group as a guide for setting international tolerances for intraocular lens (IOL) dioptric power.

SETTING

Multicenter study.

METHODS

Seven biconvex, poly(methyl methacrylate) IOLs ranging in power from 10.00 through 30.00 diopter (D) were circulated among nine participating laboratories experienced in IOL optical measurements. Each laboratory performed repeated optical tests to determine dioptric power. These results were analyzed for repeatability and reproducibility in accordance with methods specified by the International Organization for Standardization.

RESULTS

Intralaboratory repeatability was less than 0.5% of the dioptric power, and interlaboratory reproducibility, when following a normalized procedure for correction and conversion, was less than 1.0% of the dioptric power.

CONCLUSION

Tolerance limits of +/0 0.30 D in the range 0 to 15.00 D, +/- 0.40 D for 15.50 to 25.00 D, and +/- 0.50 D for 25.50 to 30.00 D have been proposed as an international standard for IOLs. The contribution of IOL power error within the limits of the standard are estimated to contribute less than 1.0% to the total error in postoperative refractive prediction.

Construction of an ultrasound biopsy phantom

The technique for construction of an agar-based ultrasound biopsy phantom is described. Features include tissue equivalent reflectivity, long life and non-shadowing targets. The phantom is useful for learning the necessary co-ordination between needle and probe for ultrasound needle guidance. This skill should initially be practised in vitro, on a device such as this.

Endogenous Fusarium endophthalmitis in a patient with acute lymphocytic leukemia

Endogenous fungal endophalmitis is an uncommon complication of systemic mycosis. Only a few cases involving Fusarium have been reported, most with unfavorable visual outcomes. We examined a 31-year-old woman with acute lymphocytic leukemia who developed sudden visual loss in her right eye. A dense, white placoid infiltrate was present in the right macula extending into the vitreous. An iris nodule and hypopyon were present in the left eye. A vitreous aspirate of the right eye was positive for Fusarium species. The patient progressively lost vision despite amphotericin B and 5-fluorocytosine therapy. She died from bronchopneumonia, fungemia, and multisystem failure. Histopathologic study disclosed a panophthalmitis with Fusarium organisms invading all the ocular coats in the right eye. Leukemic infiltrates were present in the left iris, anterior chamber, and trabecular meshwork. The ocular destructiveness of Fusarium may be caused by marked mycotic vascular invasion and occlusion with consequent infarction and necrosis of ocular tissues.

Water properties of hydrogel contact lens materials: a possible predictive model for corneal desiccation staining

A set of properties of the water contained within hydrogel contact lens materials was determined with the aim of developing a model which would predict the propensity of a hydrogel contact lens material to induce corneal desiccation staining. We postulated that materials containing a larger proportion of water with the properties of bulk water would tend to induce corneal desiccation more readily than materials with the same overall water content but containing a larger proportion of water that interacts strongly with the polymer. The water structure [as measured by differential scanning calorimetry (DSC)] and the permeabilities of water and glucose were determined for a series of commercial hydrogel lenses. Both glucose permeability and DSC measurements are sensitive indicators of water structure and able to distinguish between various materials. To illustrate the potential of our model, the results of a short-term clinical study are presented. Lower levels of staining were noted for a material with a lower glucose permeability and a larger amount of water melting below 0 degrees C than for a control lens, even though both materials were similar in water content and water permeability. Further clinical studies are needed to validate this model.

Eight years experience with Permalens intracorneal lenses in nonhuman primates

BACKGROUND

For the past 8 years, three independent laboratories have been researching the biocompatibility and performance of Permalens intracorneal lens implants in the corneas of nonhuman primates. Both myopic and hyperopic corrections have been achieved. This article describes the evolution of the intracorneal lens design and manufacturing process.

METHODS

During this time period, 63 surgeries were performed on various species of nonhuman primates. Follow-up examination extended between 30 months and 8.2 years. Objective measures of refractive performance, as well as biocompatibility were made using slit lamp, retinoscopy, autorefractor, specular microscope, etc. Additionally, histopathology was performed on many of the specimens, both acute and chronic.

RESULTS

Surgically successful implants were achieved in between 60% and 100% of eyes in the various series of lens implants outlined in the article. Levels of contamination in the preparation of hydrogels were felt to be responsible for many of the surgical failures. The removal of silicone and other contaminants seems to have significantly improved the biocompatibility of these materials within the cornea. The major histopathological finding was that there appeared to be some epithelial thinning over the implants, but in general excellent biocompatibility was obtained over the 8-year period outlined in this paper.

CONCLUSIONS

Although extensive studies of biocompatibility have been completed, the future of the performance of these materials remains to be proven in the human subject. Additionally, empirical relationships between lens implant power and refractive results will have to be determined in humans, prior to their general clinical usage.

Initial human experience with Permalens myopic hydrogel intracorneal lens implants

BACKGROUND

Previous nonhuman primate experimentation has demonstrated the successful use of Permalens hydrogel intracorneal lens implants for the correction of hyperopic and myopic refractive errors. This article documents the first human experience with myopic Permalens hydrogel intracorneal lens implants.

METHODS

In this article, we report an 18-month follow up on five patients implanted with minus power hydrogel intracorneal lenses. All surgery and follow-up examinations were performed in Bogota, Columbia. The mean preoperative spherical refraction was -14.00 +/- 5.00 diopters (range, -9.5 to -19.00 D).

RESULTS

Corrections of up to 13.00 D were achieved. Corrections deviated from the predicted correction by a mean of -5.00 +/- 2.10 D (range, -2.80 to -8.00 D). No significant surgical or postoperative complications were noted. Visual recovery was rapid, usually achieving maximum acuity within 1 month.

CONCLUSIONS

Successful myopic refractive changes were accomplished in all five human subjects. The major problem with the study to date has been a significant undercorrection of the preoperative refraction. We anticipate that further empirically derived relationships between hydrogel lens power and refractive change will allow a more accurate prediction of refractive result. Also, the ability to surgically interchange myopic hydrogel inlays should allow correction of any residual refractive errors.

Lipid adsorption onto hydrogel contact lens materials. Advantages of Nile red over oil red O in visualization of lipids

An artificial tear solution containing the major types of proteins, glycoproteins, and lipids represented in human tears has been developed. The adsorption of lipids onto various hydrogel lens materials (polymacon, lidofilcon A, phemfilcon A, etafilcon A) was examined by exposing the lenses to our artificial tear solution for 18 h. The adsorbed lipids were detected using Nile red stain. The patterns of deposits obtained in vitro were similar to those obtained with human worn lenses. The Nile red stain appeared far more sensitive in detecting lipids adsorbed to hydrogel lenses than the oil red O stain. It was found that lipids adsorb to hydrogel materials quite readily either in a pure state or combined with mucin or other proteins. In view of this work more attention should be given to the role of lipids in the etiology of various contact lens wear complications.