bluuebunny/crossref_metadata_2025 huggingface dataset:
Symptomatic intracystic hemorrhage in pineal cysts
Authors: Sarikaya-Seiwert Sevgi , Turowski Bernd , Hänggi Daniel , Janssen Giesela , Steiger Hans-Jakob , Stummer Walter
Published: September 2009

Pineal cysts are benign and often asymptomatic intracranial entities. Occasionally they can lead to neurological symptoms through growth or due to intracystic hemorrhage. The purpose of the current report is to describe their clinical characteristics and treatment options.

In the current study, the authors illustrate the course of disease in 3 patients who developed neurological symptoms due to hemorrhage into a pineal cyst. Two of their patients had additional cerebral disease, and regular MR imaging examinations were conducted. This circumstance allowed documentation of growth and intracystic hemorrhage. After the occurrence of new neurological symptoms with severe headache, MR images showed a fluid-fluid interface due to intracystic hemorrhage. The third patient presented with acute triventricular hydrocephalus and papilledema due to aqueductal stenosis caused by intracystic hemorrhage.

In all 3 cases, excision of the pineal cysts via an infratentorial/supracerebellar approach was performed. Histological examination revealed the characteristic structure of pineal cyst in all cases, with hemorrhagic residues in the form of hemosiderin deposits. All patients recovered fully after surgical removal of the cysts. Furthermore, resolution of occlusive hydrocephalus could be demonstrated in those cases with ventricular enlargement.

Pineal cysts without neurological symptoms are often discovered as incidental findings on cranial MR images. In contrast, neurological symptoms such as severe headache, diplopia, or Parinaud syndrome, may occur as a result of pineal apoplexy due to intracystic hemorrhage. The authors' cases confirm that MR imaging can identify intracystic hemorrhage by a characteristic fluid-fluid interface. Their experience suggests that microsurgical resection of cysts may be an effective and curative treatment option.
Risk factors for latex sensitization in young children with myelomeningocele
Authors: Majed Masoud , Nejat Farideh , Khashab Mostafa El , Tajik Parvin , Gharagozloo Mohammad , Baghban Mahboubeh , Sajjadnia Adeleh
Published: September 2009

Object

Patients with myelomeningoceles (MMCs) are at increased risk of latex allergy and sensitization. Number of surgeries and history of atopy are known risk factors. The object of this study was to evaluate the role of diagnostic procedures and nonsurgical treatments in latex sensitization in young patients with MMC.

Methods

Seventy-three children with MMC were included in the study. For each child a questionnaire was administered and serum determination of IgE was performed, and 62 children underwent skin prick tests (SPTs), 60 of which had reliable results. Multivariate logistic regression modeling was performed, using latex sensitization as the dependent variable.

Results

The mean age of the 73 patients was 3.8 years. The SPT results were positive in 30.6%, whereas results of testing for latex-specific IgE were positive in only 8.2%. In univariate analysis, history of untethering, barium enema, and number of clean intermittent catheterizations (CICs) per day were significantly associated with positive results on the SPT. Although the number of surgical procedures was significantly higher in patients who had shunts, no significant relationship between the presence of a shunt and latex sensitization was seen.

Conclusions

The young age of the patients in this study may account for the low prevalence of latex sensitization that was found. In young patients with MMC, the numbers of CICs per day, a history of untethering, circumcision, and a barium enema performed without latex-free equipment could be risk factors for latex sensitization. The use of latex-free gloves in all procedures performed in these cases, nonlatex polyvinyl chloride catheters in CIC, and ordinary nonballoon tips in barium enemas could decrease the risk of sensitization.
Forniceal glioma in children
Authors: Blauwblomme Thomas , Varlet Pascale , Goodden John R. , Cuny Marie Laure , Piana Helene , Roujeau Thomas , DiRocco Federico , Grill Jacques , Kieffer Virginie , Boddaert Nathalie , Sainte-Rose Christian , Puget Stéphanie
Published: September 2009

Object

Five to ten percent of pediatric brain tumors are located in the ventricles. Among them, forniceal lesions are rare and their management has not often been described. The aim of this study was to review the clinical, radiological, and histopathological features as well as the feasibility of surgical excision and the outcomes in these patients.

Methods

From a retrospective analysis of 250 cases of supratentorial pediatric glioma, the records of 8 children presenting with forniceal lesions were selected and reviewed.

Results

The median age of patients in the cohort was 13.5 years. Presenting features included intracranial hypertension (7 cases), hypothalamic dysfunction (2), and memory dysfunction (3). Complete resection was possible in only 1 case, where the lesion was mainly exophytic; the remaining patients had either a partial resection or biopsy. On histological review, the tumors were confirmed as pilocytic astrocytoma (4 lesions), WHO Grade II astrocytoma (3), and ganglioglioma (1). Postoperatively, working and retrograde memory was normal for all patients, but the authors found a mild alteration in verbal episodic memory in 5 patients. Despite fatigability for 5 patients, academic achievement was normal for all but 2, both of whom had preoperative school difficulties. Additional treatment was required for 5 patients for tumor progression, with a median interval of 19 months from surgery. At a median follow-up duration of 4.9 years, all patients had stable disease.

Conclusions

In this series, forniceal gliomas were found to be low-grade gliomas. They are surgically challenging, and only exophytic lesions may be cured surgically. Due to the high rate of progression of residual disease, adjuvant therapy is recommended for infiltrative tumors, and it yielded excellent results.
Neurosurgical management of intracranial epidermoid tumors in children
Authors: Ahmed Ibrahim , Auguste Kurtis I. , Vachhrajani Shobhan , Dirks Peter B. , Drake James M. , Rutka James T.
Published: September 2009

Object

Epidermoid tumors are benign lesions representing 1% of all intracranial tumors. There have been few pediatric series of intracranial epidermoid tumors reported previously. The authors present their experience in the management of these lesions.

Methods

The neurosurgical database at the Hospital for Sick Children was searched for children with surgically managed intracranial epidermoid tumors. The patients' charts were reviewed for demographic data, details of clinical presentation, surgical therapy, and follow-up. Ethics board approval was obtained for this study.

Results

Seven children, all girls, were identified who met the inclusion criteria between 1980 and 2007. The average age at surgery was 11.2 years (range 8–15 years), and the mean maximal tumor diameter was 2.1 cm. Headache was the most common presenting symptom, and 1 tumor was found incidentally. Most patients had normal neurological examinations, but meningism was found in 2 cases. There were 3 cerebellopontine angle lesions, 1 pontomedullary lesion, and 3 supratentorial tumors. Hydrocephalus developed in 1 patient after aseptic meningitis, and she underwent shunt placement. There were no operative deaths. Complete resection could be performed in 2 patients. One patient experienced a small recurrence that did not require a repeated operation, while 1 subtotally resected lesion recurred and the patient underwent a second operation.

Conclusions

Intracranial epidermoid tumors are rare in the pediatric population. Total resection is desirable to minimize the risk of postoperative aseptic meningitis, hydrocephalus, and tumor recurrence. Aggressive neurosurgical resection may be associated with cranial nerve or ischemic deficits, however. In these cases, neurosurgical judgment at the time of surgery is warranted to ensure maximum resection while minimizing postoperative neurological deficits.
Endoscopic transventricular positioning of intracystic catheter for treatment of craniopharyngioma
Authors: Pettorini Benedetta L. , Tamburrini Gianpiero , Massimi Luca , Caldarelli Massimo , Di Rocco Concezio
Published: September 2009

The intracystic injection of chemo- and radiotherapeutic agents was introduced for the treatment of craniopharyngioma to control tumor growth and to delay the potentially harmful effects of surgery or radiation therapy. The positioning of cyst catheters has been performed by means of direct vision, stereotactically guided insertion, and ultrasonographic and ventriculoscopic guidance. The insertion of a catheter into the cyst is not devoid of complications, with an incidence ranging up to 16%, independent of the surgical technique used.

Eight patients (mean age 25.8 years) with symptomatic cystic craniopharyngioma were treated by means of an endoscopic transventricular approach for the insertion of an intracystic catheter for intratumoral therapy with interferon-α.

A single right precoronal bur hole is made, and the frontal horn of the lateral ventricle is accessed under neuronavigation guidance. A ventricular catheter with an inserted stylet was advanced anterior to the endoscope sheath through the same cortical access as the endoscope and was guided under endoscopic view down to the cyst dome wall. The coagulated surface of the craniopharyngioma cyst was punctured and the tip of the ventricular catheter was advanced; the depth was established preoperatively on MR scans and confirmed by neuronavigation guidance. The proximal end of the cystic catheter was connected to an access chamber to be left in the subcutaneous space, and the endoscope was slowly retracted.

The authors' experience favors the use of neuroendoscopic positioning of intracystic catheters as safer than open and stereotactic approaches.
Quantification of Everest region glacier velocities between 1992 and 2002, using satellite radar interferometry and feature tracking
Authors: Quincey D.J. , Luckman A. , Benn D.
Published: September 2009

Many glacier snouts in the Himalaya are known to be stagnant and exhibiting low surface gradients, conditions that are conducive to the formation of glacial lakes impounded either by the terminal moraine or by the remnant glacier snout. In this study, we use interferometry and feature-tracking techniques to quantify the extent of stagnation in 20 glaciers across the Everest (Qomolangma; Sagarmatha) region, and subsequently we examine the relationship between local catchment topography and ice dynamics. The results show that only one of the studied glaciers, Kangshung Glacier, is dynamic across its entire surface, with flow rates greater than 40 m a−1 being recorded in high-elevation areas. Twelve other glaciers show some evidence of flow, but are generally characterized by long, stagnant tongues, indicating widespread recession and in situ decay. The remaining seven glaciers show no evidence of flow in any of the available datasets. Hypsometric data suggest that catchment topography plays an important role in controlling glacier flow regimes, with those fed by wide, high-altitude accumulation areas showing the most extensive active ice, and those originating at low elevations exhibiting large areas of stagnant ice. Surface profiles extracted from a SRTM digital elevation model indicate that stagnant snouts are characterized by very low (<2°) surface angles and that down-wasting is the prevalent ablation pattern in the study area.
Synthesis of 4-[10H-Phenothiazin-10-yl(1H-tetrazol-5-yl)-methyl]phenol
Authors: Venkatraman Bathey , Kavitha Helen
Published: September 2009

This present work aims at synthesizing a novel tetrazole from phenothiazine. Phenothiazine is converted into a nitrile by reacting it with 4-hydroxybenzaldehyde, sodium metabisulphite and sodium cyanide. The nitrile on treatment with NaN3/DMF yielded the corresponding tetrazole. The tetrazole obtained was characterized by IR, 1H NMR, EI-MS and elemental analysis.
Antibacterial Activity of 2-(2’,4’-Dibromophenoxy)-4,6-dibromophenol from Dysidea granulosa
Authors: Shridhar Divya M.  P. , Mahajan Girish  B. , Kamat Vijayendra  P. , Naik Chandrakant  G. , Parab Rajashri  R. , Thakur Nidhi  R. , Mishra Prabhu  D.
Published: September 2009

2-(2’,4’-Dibromophenoxy)-4,6-dibromophenol isolated from the marine sponge Dysidea granulosa (Bergquist) collected off the coast of Lakshadweep islands, Indian Ocean, exhibited potent and broad spectrum in-vitro antibacterial activity, especially against methicillin resistant Staphylococcus aureus (MRSA), methicillin sensitive Staphylococcus aureus (MSSA), vancomycin resistant Enterococci (VRE), vancomycin sensitive Enterococci (VSE) and Bacillus spp. Minimal inhibitory concentration (MIC) was evaluated against 57 clinical and standard strains of Gram positive and Gram negative bacteria. The observed MIC range was 0.117-2.5 μg/mL against all the Gram positive bacteria and 0.5-2 μg/mL against Gram negative bacteria. The in-vitro antibacterial activity observed was better than that of the standard antibiotic linezolid, a marketed anti-MRSA drug. The results establish 2-(2’,4’-dibromophenoxy)-4,6-dibromophenol, as a potential lead molecule for anti-MRSA and anti-VRE drug development.
Dendrimer-Capped Nanoparticles Prepared by Picosecond Laser Ablation in Liquid Environment
Authors: Giorgetti Emilia , Giusti Anna , Giammanco Francesco , Marsili Paolo , Laza Simona
Published: September 2009

Fifth generation ethylendiamine-core poly(amidoamine) (PAMAM G5) is presented as an efficient capping agent for the preparation of metal and semiconductor nanoparticles by ps laser ablation in water. In particular, we describe results obtained with the fundamental, second and third harmonic of a ps Nd:YAG laser and the influence of laser wavelength and pulse energy on gold particle production and subsequent photofragmentation. In this framework, the role of the dendrimer and, in particular, its interactions with gold clusters and cations are accounted.
Taiwanese Nursing Students' Attitudes Toward Older People
Authors: Pan I-Ju , Edwards Helen , Chang Anne
Published: September 2009

The aim of this research was to establish Taiwanese undergraduate nursing students' attitudes toward older people. This study involved a cross-sectional survey of 362 nursing students in a university in southern Taiwan. Overall, the results showed that nursing students had positive attitudes toward older people. Moreover, the findings suggested that nursing students' intention to work with older people and gender were important factors influencing their attitudes toward older people. The findings of this study indicate that efforts are required to maintain these positive attitudes. In addition, provision of nursing courses related to older people that place greater emphasis on attitudes about aging and that take into account students' working experience and career intention will lead to higher quality of care for older people.
The Importance of Living Wills and Advance Directives
Authors: Alfonso Heather
Published: September 2009

Living wills and advance directives are important components of patients' medical records, which all too often do not indicate the appropriate palliative care measures the patient desires. A review of the current literature indicates that approximately 85% to 95% of the population does not have adequate advance directives or palliative care measures written in their medical record. Furthermore, these orders may not follow the patient when he or she is transferred to other facilities for intermittent care. Unwanted tracheal intubations can be both costly to the facility and distressing to the patient and family members. By instituting a change in policy, organizations can ensure that patients' wishes for end-of-life care are met appropriately. In addition, nurses should advocate for a centralized database at the political level.
Medication Adherence and Older Renal Transplant Patients' Perceptions of Electronic Medication Monitoring
Authors: Russell Cynthia L. , Owens Sarah , Hamburger Karen Q. , Thompson Denise A. , Leach Rebecca R. , Cetingok Muammer , Hathaway Donna , Conn Vicki S. , Ashbaugh Catherine , Peace Leanne , Madsen Richard , Winsett Rebecca P. , Wakefield Mark R.
Published: September 2009

This study evaluated older renal transplant recipients' perceptions of electronic medication monitoring and the influence of these perceptions on medication adherence. A sample of 73 older adult renal transplant recipients who used the Medication Event Monitoring System (MEMS
®
) TrackCaps for 12 months provided their perceptions of device use. Participants perceived that the MEMS had a neutral effect on their medication-taking routine (65%), believed the MEMS was practical (56%), and could not describe any instances in which using the MEMS was difficult (56%). No significant difference in medication adherence was found between those who perceived the MEMS's influence negatively/neutrally and those who perceived the MEMS positively (
p
= 0.22). Medication adherence data from older adult renal transplant recipients can be used regardless of their perceptions of the MEMS's influence on their medication taking without biasing medication adherence data.
Behavioral Management of Auditory Hallucinations: Implementation and Evaluation of a 10-Week Coure
Authors: Buffum Martha D. , Buccheri Robin , Trygstad Louise , Gerlock April A. , Birmingham Patricia , Dowling Glenna A. , Kuhlman Gloria J.
Published: September 2009

A 10-session behavioral course for self-management of auditory hallucinations in patients with schizophrenia has demonstrated positive outcomes. This article evaluates both the course's implementation and benefits to patients attending the course. Teleconferencing, electronic media, and 26 monthly conference calls were used to educate six advanced practice nurses (APNs) at six sites about the course implementation. Thirty-two patients within the U.S. Department of Veterans Affairs participated in the course. All of the APNs reported course helpfulness, improved communication with patients about voices, and improved harm assessment. Of the patients, 96% found the course helpful: 67% no longer heard voices to harm self or others, and 60% had improved auditory hallucination intensity scores. The project demonstrated successful implementation and practice integration with APNs' activities corresponding to Rogers' stages of innovation adoption. Facilitators and barriers to implementation are also described.
Psychiatric Nurses' Decision to Restrain: The Association Between Empowerment and Individual Factors
Authors: Lindsey Pamela L.
Published: September 2009

The use of restraints in all health care settings has come under increased scrutiny in recent years. Although the organizational context has been suggested as a possible influence on restraint use, few researchers have examined whether organizational factors affect use of restraints and nurses' decisions to restrain patients hospitalized in psychiatric facilities. The purpose of this study was to examine the association of nurses' work empowerment (an indicator of organizational culture) with nurses' decision to restrain. This study also examined the association between individual characteristics of the patient and of the nurses with nurses' decision to restrain. Lastly, this study examined the decision patterns used by psychiatric nurses in response to patient situations in which restraint might be considered.
Weight Gain with Atypical Antipsychotic Drugs in Bipolar Disorder: Nursing Management
Authors: Callan Judith A. , Howland Robert H. , Puskar Kathryn
Published: September 2009

Diana is a 21-year-old student who lives with her parents. She had been enrolled in college but has taken a temporary leave of absence due to the instability of her bipolar disorder. Since being diagnosed at age 18, Diana's treatment team has been unable to find a medication regimen that would maintain her stability. She has had several breakthrough manic episodes that resulted in significant risky and inappropriate behaviors on campus. The cognitive, motivational, and energy limitations of depression left her unable to keep up with school requirements. Dr. Spiker, her regular psychiatrist, prescribed olanzapine (Zyprexa
®
) 5 mg. Both Diana and Dr. Spiker are concerned about potential weight gain but consider this intervention necessary, as other medication trials have been unsuccessful.
Influence of High-Dose Cortisol on the Biomechanics of Incubated Porcine Corneal Strips
Authors: Spoerl Eberhard , Zubaty Viktoria , Terai Naim , Pillunat Lutz E. , Raiskup Frederik
Published: September 2009

Purpose:

To investigate the change in biomechanical properties of the cornea induced by high-dose hydro-cortisone.

Methods:

The influence of hydrocortisone was investigated in 12 fresh porcine corneas incubated in culture medium of 2.5 µM of hydrocortisone for 7 days. Twelve additional porcine corneas incubated in culture medium without hydrocortisone for the same time served as the control group. Strips of cornea were cut and the stress–strain relationship was measured in a biomaterial tester. Young's modulus was calculated.

Results:

After incubation, the thickness of the cornea was 1120±130 µm in the control group and 1320±90 µm in the hydrocortisone group. The hydrocortisonetreated corneas were 18% thicker compared to the control corneas. However, the difference in the biomechanical stress value at 10% strain was significantly larger. In the control group, the stress value measured 122±40 kPa, and in the hydrocortisone group, it measured 77±19 kPa (P=.003), representing a reduction of the corneal stiffness by 37% due to hydrocortisone treatment. Young's modulus was reduced by 42.8% from 2.90±1.10 MPa in the control group to 1.66±0.49 in the hydrocortisone group.

Conclusions:

Hydrocortisone is a modulating factor of the biomechanical properties of the cornea. The significance of the cortisol status of the patient and its influence on the biomechanical stability of the cornea should be considered in the development of keratectasia in keratoconus or after refractive surgery. [J Refract Surg. 2009;25:S794–S798.]
In Vitro Antimicrobial Efficacy of Riboflavin and Ultraviolet Light onStaphylococcus aureus, Methicillin-resistantStaphylococcus aureus, andPseudomonas aeruginosa
Authors: Schrier Amilia , Greebel Gennifer , Attia Hosam , Trokel Stephen , Smith Edward F.
Published: September 2009

Purpose:

Ultraviolet (UV) light and riboflavin has been developed as a collagen cross-linking treatment for corneal ectasia. This treatment has also been used to treat infectious corneal ulcers with apparent favorable results. In this experiment, the antibacterial action of riboflavin alone, UV light alone, and the combination of riboflavin and UV light was tested onStaphylococcus aureus, methicillin-resistantS aureus(MRSA), andPseudomonas aeruginosa.

Methods:

Thirty agar plates withS aureusoverlays were used. Ten plates were exposed to riboflavin (0.1% solution in dextran) alone, 10 plates were exposed to UV light (365 nm) alone, and 10 plates were exposed to a combination of riboflavin and UV light. Fifteen agar plates with MRSA and 15 plates withP aeruginosawere tested. Five plates of each group were exposed to riboflavin, 5 plates of each group were exposed to UV light alone, and 5 plates of each group were exposed to a combination of riboflavin and UV light. All plates were incubated for 24 hours and then analyzed.

Results:

All plates exposed to riboflavin alone showed no bacterial death. AllS aureusand MRSA plates exposed to UV light alone showed no bacterial growth. Three of fiveP aeruginosaplates exposed to UV light alone showed no bacterial death; two of fiveP aeruginosaplates exposed to UV light alone showed minimal inhibition. All plates exposed to the combination of riboflavin and UV light showed bacterial death.

Conclusions:

Riboflavin in combination with UV light is an effective modality to eradicate the bacteriaS aureus, MRSA, andP aeruginosa. [J Refract Surg. 2009;25: S799–S802.]
Keratitis and Corneal Scarring After UVA/Riboflavin Cross-linking for Keratoconus
Authors: Koppen Carina , Vryghem Jérôme C. , Gobin Laure , Tassignon Marie-José
Published: September 2009

Purpose:

To report four cases of severe keratitis after standard corneal collagen cross-linking (CXL) treatment for keratoconus.

Methods:

Four patients with progressive keratoconus from two different centers were treated by ultraviolet A (UVA) CXL, using riboflavin as a photosensitizer. The epithelium was removed over the central 8 to 9 mm of the cornea. Riboflavin 0.1% in dextran 20% was instilled every 2 minutes for 30 minutes before UVA exposure. The UV-X™ light source (IROC), calibrated at 3 mW/cm
2
, was applied for 30 minutes while instillation was continued every 2 minutes. At the end of the treatment, a bandage contact lens was applied and topical treatment consisting of a combination of antibiotics and/or anti-inflammatory drops was initiated.

Results:

Patients experienced delayed (after more than 24 hours) symptoms and signs of inflammation. The eyes showed pronounced ciliary redness with cells in the anterior chamber and central keratic precipitates; multiple white infiltrates had developed at the edge and within the area of CXL. High-dose topical or subconjunctival corticosteroids led to rapid initial improvement of symptoms and signs. Herpes virus could not be detected on the ocular surface or on the anterior chamber tap of one patient.

Conclusions:

We report four cases of keratitis and corneal scarring from a total of 117 eyes treated with CXL. The location of the scarring determined the amount of loss of visual acuity: in two eyes, there was a persistent decrease in best spectacle-corrected visual acuity. [
J Refract Surg
. 2009;25:S819–S823.]
Permanent Corneal Haze After Riboflavin-UVA-induced Cross-Linking in Keratoconus
Authors: Raiskup Frederik , Hoyer Anne , Spoerl Eberhard
Published: September 2009

Purpose:

Retrospective evaluation of haze development after riboflavin-ultraviolet (UV) A-induced corneal collagen cross-linking (CXL).

Methods:

One hundred sixty-three eyes of 127 patients with stage 1–3 keratoconus according to Krumeich's classification were included in this retrospective analysis. Follow-up was 1 year. Preoperatively and at all follow-up examinations uncorrected visual acuity, best spectacle-corrected visual acuity (BSCVA), slit-lamp microscopic findings, corneal topography, and corneal thickness were recorded.

Results:

At 1 year after CXL, 149 (91.4%) eyes of 114 patients had a clear cornea without stromal haze (control group), whereas 14 eyes (8.6%) of 13 patients developed clinically significant stromal haze (haze group). Preoperatively, the mean keratometry (K) value of the apex was 62.1±13.8 diopters (D) in the control group and 71.1±13.2 D in the haze group (
P
=.02). The mean corneal thickness before the procedure was 478.1±52.4 µm in the control group and 420.0±33.9 µm in the haze group (
P
=.001). Uncorrected visual acuity and BSCVA, which were similar between groups preoperatively (
P
=.59 and
P
=.75, respectively), were improved in the control group (
P
=.023 and
P
=.001, respectively), but reduced in the haze group (
P
=.012 and
P
=.004, respectively) postoperatively.

Conclusions:

The parameters defining the stage of keratoconus, such as K-value and corneal thickness, could be considered predicting factors for possible development of corneal haze after riboflavin-UVA-induced CXL. Advanced keratoconus should be considered at higher risk of haze development after CXL due to low corneal thickness and high corneal curvature. [
J Refract Surg
. 2009;25:S824–S828.]
Reproducibility of Tear Meniscus Measurement by Fourier-Domain Optical Coherence Tomography: A Pilot Study
Authors: Zhou Sheng , Li Yan , Lu Ake Tzu-Hui , Liu Pengfei , Tang Maolong , Yiu Samuel C. , Huang David
Published: September 2009

Background and Objective:

To study the reproducibility of tear meniscus measurement with high-speed high-resolution Fourier-domain optical coherence tomography (FD-OCT).

Patients and Methods:

Twenty normal participants were enrolled in this prospective study. The lower tear meniscus in the right eye of each subject was imaged by vertical scans centered on the inferior cornea and the lower eyelid using an FD-OCT system (RTVue; Optovue, Inc., Fremont, CA) with a corneal adaptor. The system performs 26,000 axial scans per second and has a 5-micron axial resolution. Each subject was examined at two visits 30 to 60 days apart. Each eye was scanned twice on each visit. The scans were taken 2 seconds after a blink. The lower meniscus height, depth, and cornea–meniscus angle were measured with a computer caliper. The cross-sectional area was calculated using a two-triangle approximation.

Results:

The between-visits coefficient of variation was 17.5%, 18.0%, 35.5%, and 12.2% for meniscus height, depth, area, and angle, respectively. The intraclass correlations for these parameters were 0.605, 0.558, 0.567, and 0.367, respectively.

Conclusion:

FD-OCT measures lower tear meniscus dimensions and area with higher between-visits reproducibility than previous OCT instruments. FD-OCT may be a useful way to measure dry eye severity and treatment effectiveness.

[Ophthalmic Surg Lasers Imaging 2009;40:442–447.]
Effectiveness of Laser Photocoagulation in Clinically Significant Macular Edema With Focal Versus Diffuse Parafoveal Thickening on Optical Coherence Tomography
Authors: Barkmeier Andrew J. , Nicholson Benjamin P. , Akduman Levent
Published: September 2009

Background and Objective:

To evaluate whether increased foveal thickness in clinically significant diabetic macular edema responds differently to modified focal/grid laser photocoagulation in the setting of focal versus diffuse parafoveal thickening as defined by optical coherence tomography (OCT) criteria.

Patients and Methods:

The medical records of patients undergoing macular laser procedures for clinically significant diabetic macular edema were retrospectively reviewed. OCT, demographic, and clinical data were recorded for 62 consecutive eyes with clinically significant diabetic macular edema and foveal thickening (> 230 microns). Diffuse parafoveal thickening was defined as having all four parafoveal OCT quadrants greater than 300 microns, whereas focal thickening was defined as having fewer than four quadrants greater than 300 microns.

Results:

Mean foveal thickness decreased from 331 to 311 microns with relatively stable visual acuity (20/54 vs 20/51) after a single laser treatment session. The diffuse parafoveal edema subgroup (24 eyes) had a mean foveal thickness change from 383 to 366 microns (
P
= .47) and mildly decreased visual acuity (20/62 vs 20/69). The focal parafoveal edema subgroup (38 eyes) experienced statistically significant foveal thinning from 299 to 276 microns (
P
= .018) and mildly improved visual acuity (20/48 to 20/43).

Conclusion:

Increased foveal thickening associated with clinically significant diabetic macular edema responds more favorably to modified focal/grid laser photocoagulation in the setting of focal parafoveal edema by OCT criteria. Statistically significant foveal thinning occurred following treatment in the focal group (
P
= .018) but not the diffuse group (
P
= .47). Furthermore, eyes with focal parafoveal edema experienced a more beneficial visual acuity response than those with diffuse edema (
P
= .049).

[Ophthalmic Surg Lasers Imaging 2009;40:472–479.]
High-Resolution Ocular Imaging: Combining Advanced Optics and Microtechnology
Authors: Cordeiro M. Francesca , Nickells Robert , Drexler Wolfgang , Borrás Terete , Ritch Robert
Published: September 2009

Recent developments in imaging technologies offer great potential for the assessment of retinal ganglion cell disorders, with particular relevance to glaucoma. In particular, advances in this field have allowed unprecedented in vivo access to the retinal layers, using many different properties of light to differentiate cellular structures. This article is a summary of currently available and investigational advanced, high-resolution imaging technologies and their potential applications to glaucoma. It represents the topics of discussion at the annual Optic Nerve Rescue and Restoration Think Tank, sponsored by The Glaucoma Foundation, entitled “High Resolution Imaging of the Eye: Advanced Optics, Microtechnology and Nanotechnology” and held in New York, New York, September 28–29, 2007.
[Ophthalmic Surg Lasers Imaging 2009;40:480–488.]
Macular Star Secondary to Nasal Branch Retinal Vein Occlusion
Authors: Parodi Maurizio Battaglia , Iacono Pierluigi , Ravalico Giuseppe
Published: September 2009

An 83-year-old woman affected by nasal branch retinal vein occlusion with macular star underwent treatment with intravitreal triamcinolone acetonide injection followed by laser treatment addressed to the leaking vascular lesions. Visual acuity improved from 20/200 to 20/40 with a remarkable reduction of the macular exu-dates and resolution of dye leakage on fluorescein angiography over a 2-year follow-up. Nasal branch retinal vein occlusion may rarely occur with macular edema and macular star. Intravitreal triamcinolone acetonide injection and laser treatment of the leaking vascular lesions can result in visual function improvement over a 2-year follow-up.
[Ophthalmic Surg Lasers Imaging 2009;40:504–505.]
Prospective Scope of Forest Management Education at James Madison's Montpelier
Authors: Munsell John F. , Hamilton Rachel , Downing Adam K.
Published: September 2009

Urban sprawl and intergenerational transfers are fostering a new period of family forest ownership in the United States typified by larger numbers of younger owners with smaller parcels that are interested in managing their forests but often lacking requisite knowledge. At the same time, there is a general decline in the public's connection to forests and appreciation of forestry. In light of these circumstances, forest management educators are increasing opportunities for younger citizens, owners of small forests, and suburban and urban residents. Incorporating forest management education into heritage tourism offers an approach that could contribute to ongoing efforts. The potential scope of such a strategy is possible to explore within the context of a newly created outdoor sustainable forestry education initiative at James Madison's Montpelier. Knox's (2002) Adult Basic Education Guide was used to guide a formative evaluation of visitor participation in outdoor sustainable forestry education at Montpelier. Results suggest the initiative may help reach a sizeable number of key constituents. The implications for reaching family owners of smaller acreages, engaging younger citizens and likely opinion leaders, future program development, and potential impacts are discussed.
Definition of Implanted Neurological Device Abandonment
Authors: Okun Michael S. , Marjenin Timothy , Ekanayake Jinendra , Gilbert Frederic , Doherty Sean P. , Pilkington Jack , French Jennifer , Kubu Cynthia , Lázaro-Muñoz Gabriel , Denison Timothy , Giordano James
Published: April 2024

Importance

Establishing a formal definition for neurological device abandonment has the potential to reduce or to prevent the occurrence of this abandonment.

Objective

To perform a systematic review of the literature and develop an expert consensus definition for neurological device abandonment.

Evidence Review

After a Royal Society Summit on Neural Interfaces (September 13-14, 2023), a systematic English language review using PubMed was undertaken to investigate extant definitions of neurological device abandonment. Articles were reviewed for relevance to neurological device abandonment in the setting of deep brain, vagal nerve, and spinal cord stimulation. This review was followed by the convening of an expert consensus group of physicians, scientists, ethicists, and stakeholders. The group summarized findings, added subject matter experience, and applied relevant ethics concepts to propose a current operational definition of neurological device abandonment. Data collection, study, and consensus development were done between September 13, 2023, and February 1, 2024.

Findings

The PubMed search revealed 734 total articles, and after review, 7 articles were found to address neurological device abandonment. The expert consensus group addressed findings as germane to neurological device abandonment and added personal experience and additional relevant peer-reviewed articles, addressed stakeholders’ respective responsibilities, and operationally defined abandonment in the context of implantable neurotechnological devices. The group further addressed whether clinical trial failure or shelving of devices would constitute or be associated with abandonment as defined. Referential to these domains and dimensions, the group proposed a standardized definition for abandonment of active implantable neurotechnological devices.

Conclusions and Relevance

This study’s consensus statement suggests that the definition for neurological device abandonment should entail failure to provide fundamental aspects of patient consent; fulfill reasonable responsibility for medical, technical, or financial support prior to the end of the device’s labeled lifetime; and address any or all immediate needs that may result in safety concerns or device ineffectiveness and that the definition of abandonment associated with the failure of a research trial should be contingent on specific circumstances.
Prescription and Dispensation of QT-Prolonging Medications in Individuals Receiving Hemodialysis
Authors: Wang Virginia , Wang Chin-Hua (Lily) , Assimon Magdalene M. , Pun Patrick H. , Winkelmayer Wolfgang C. , Flythe Jennifer E.
Published: April 2024

Importance

Individuals with dialysis-dependent kidney failure have numerous risk factors for medication-related adverse events, including receipt of care by multiple clinicians and initiation of some QT-prolonging medications with known risk of torsades de pointes (TdP), which is associated with higher risk of sudden cardiac death. Little is known about the prescription and dispensation patterns of QT-prolonging medications among people receiving dialysis, hindering efforts to reduce drug-related harm from these and other medications in this high-risk population.

Objective

To examine prescription and dispensation patterns of QT-prolonging medications with known TdP risk and selected interacting medications prescribed to individuals receiving hemodialysis.

Design, Setting, and Participants

This cross-sectional study included patients 60 years or older who were enrolled in Medicare Parts A, B, and D receiving in-center hemodialysis from January 1 to December 31, 2019. Analyses were conducted from October 20, 2022, to June 16, 2023.

Exposures

New-user prescriptions for the 7 most frequently filled QT-prolonging medications characterized by the timing of the new prescription relative to acute care encounters, the type of prescribing clinician and pharmacy that dispensed the medication, and concomitant use of selected medications known to interact with the 7 most frequently filled QT-prolonging medications with known TdP risk.

Main Outcomes and Measures

The main outcomes were the frequencies of the most commonly filled and new-use episodes of QT-prolonging medications; the timing of medication fills relative to acute care events; prescribers and dispensing pharmacy characteristics for new use of medications; and the frequency and types of new-use episodes with concurrent use of potentially interacting medications.

Results

Of 20 761 individuals receiving hemodialysis in 2019 (mean [SD] age, 74 [7] years; 51.1% male), 10 992 (52.9%) filled a study drug prescription. Approximately 80% (from 78.6% for odansetron to 93.9% for escitalopram) of study drug new-use prescriptions occurred outside of an acute care event. Between 36.8% and 61.0% of individual prescriptions originated from general medicine clinicians. Between 16.4% and 26.2% of these prescriptions occurred with the use of another QT-prolonging medication. Most potentially interacting drugs were prescribed by different clinicians (46.3%-65.5%).

Conclusions and Relevance

In this cross-sectional study, QT-prolonging medications for individuals with dialysis-dependent kidney failure were commonly prescribed by nonnephrology clinicians and from nonacute settings. Prescriptions for potentially interacting medications often originated from different prescribers. Strategies aimed at minimizing high-risk medication-prescribing practices in the population undergoing dialysis are needed.
Accuracy of Event Rate and Effect Size Estimation in Major Cardiovascular Trials
Authors: Olivier Christoph B. , Struß Lasse , Sünnen Nathalie , Kaier Klaus , Heger Lukas A. , Westermann Dirk , Meerpohl Joerg J. , Mahaffey Kenneth W.
Published: April 2024

Importance

For the design of a randomized clinical trial (RCT), estimation of the expected event rate and effect size of an intervention is needed to calculate the sample size. Overestimation may lead to an underpowered trial.

Objective

To evaluate the accuracy of published estimates of event rate and effect size in contemporary cardiovascular RCTs.

Evidence Review

A systematic search was conducted in MEDLINE for multicenter cardiovascular RCTs associated with MeSH (Medical Subject Headings) terms for cardiovascular diseases published in the New England Journal of Medicine, JAMA, or the Lancet between January 1, 2010, and December 31, 2019. Identified trials underwent abstract review; eligible trials then underwent full review, and those with insufficiently reported data were excluded. Data were extracted from the original publication or the study protocol, and a random-effects model was used for data pooling. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses reporting guideline. The primary outcome was the accuracy of event rate and effect size estimation. Accuracy was determined by comparing the observed event rate in the control group and the effect size with their hypothesized values. Linear regression was used to determine the association between estimation accuracy and trial characteristics.

Findings

Of the 873 RCTs identified, 374 underwent full review and 30 were subsequently excluded, resulting in 344 trials for analysis. The median observed event rate was 9.0% (IQR, 4.3% to 21.4%), which was significantly lower than the estimated event rate of 11.0% (IQR, 6.0% to 25.0%) with a median deviation of −12.3% (95% CI, −16.4% to −5.6%; P < .001). More than half of the trials (196 [61.1%]) overestimated the expected event rate. Accuracy of event rate estimation was associated with a higher likelihood of refuting the null hypothesis (0.13 [95% CI, 0.01 to 0.25]; P = .03). The median observed effect size in superiority trials was 0.91 (IQR, 0.74 to 0.99), which was significantly lower than the estimated effect size of 0.72 (IQR, 0.60 to 0.80), indicating a median overestimation of 23.1% (95% CI, 17.9% to 28.3%). A total of 216 trials (82.1%) overestimated the effect size.

Conclusions and Relevance

In this systematic review of contemporary cardiovascular RCTs, event rates of the primary end point and effect sizes of an intervention were frequently overestimated. This overestimation may have contributed to the inability to adequately test the trial hypothesis.
Believing in conspiracy theories: The role of emotional granularity and maladaptive emotion regulation strategies
Authors: Wabnegger Albert , Potthoff Jonas , Schienle Anne
Published: April 2024

The COVID‐19 pandemic has accelerated the spread of conspiracy theories. Previous research has found that individuals who struggle with emotion regulation are more prone to believing in conspiracy theories. Emotional granularity, or the ability to differentiate between nuanced emotional states, is a key component of effective emotion regulation, yet its relationship with conspiracy beliefs has not been explored thoroughly. Thus, we conducted an experience‐sampling study (165 participants, mean age = 26.32 years) including measures of emotion regulation and differentiation. The findings revealed that individuals who endorse conspiracy theories engage in repetitive thinking about the causes and consequences of events and exhibit a reduced ability to distinguish between negative emotions. This effect, however, was observed only in the performance‐based measure of emotion differentiation, not in the self‐report measures. This suggests that enhancing emotional granularity may help individuals in regulating their emotions more effectively, thereby reducing their vulnerability to adopt conspiracy beliefs.
Fixed‐time adaptive neural network tracking control for output‐constrained high‐order systems using command filtered strategy
Authors: Chen Lian , Tang Junzhong , Ling Song
Published: April 2024

This article proposes a fixed‐time adaptive neural command filtered controller for a category of high‐order systems based on adding a power integrator technique. Different from existing research, the presented controller has the following distinguishing advantages: (i) a fixed‐time control framework is extended to the tracking control problem of high‐order systems. (ii) The error compensation mechanism eliminates filter errors that arise from dynamic controllers. (iii) Growth assumptions about unknown functions are relaxed with the help of adaptive neural networks. (iv) More general systems: the developed controller can apply to high‐order systems subject to uncertain dynamics, unknown gain functions and asymmetric constraints. Stability analysis shows that all states are semi‐globally uniformly ultimately bounded, and the convergence rate of tracking error is independent of initial conditions. Finally, simulation results validate the advantages and efficacy of the developed control scheme.
Magnesium Test: Universal and Ultra‐Sensitive Method for Measuring Reliability of Thin‐Film‐Encapsulated Bioelectronic Implants in Physiological Environment
Authors: Mariello Massimo , Ayama Kosuke , Wu Kangling , Baudino Costanza , Wang Lei , Mutschler Léo , Jourdan Lucas Aurélien , Cleusix Marion Bianca , Furfaro Ivan , Kathe Claudia , Courtine Grégoire , von Allmen Marion , Van Gompel Matthias , Leterrier Yves , Lacour Stéphanie P.
Published: April 2024

Next‐generation bioelectronic implants require miniaturization, durability, and long‐term functionality. Thin film encapsulations, prepared with inorganic or hybrid organic/inorganic designs, are essential for ensuring protection, low water permeation, adaptability, and structural strength. It is equally important to precisely measure their barrier performance, especially for in vivo use, to ensure the manufacture of reliable bioelectronics. Current monitoring solutions are not adequate: they are bulky, lack sensitivity, and are incompatible with microfabricated devices. Here, a comprehensive method is introduced to quantify the permeability of thin‐film encapsulation for bioelectronic implants both in situ and in real time. This method relies on monitoring the electrical resistance of the Mg film, which experiences corrosion due to water permeation, leading to Mg hydrolysis. An analytical model is proposed that predicts and quantifies this permeation, and is adaptable for various types of encapsulations, including hybrid multilayers. An unprecedented ultra‐low detection limit of 3 × 10−8 g m−2 d−1at room temperature is demonstrated and the monitoring approach is validated in vivo using polyimide and poly(dimethylsiloxane)‐coated bioelectronics.