Oligodendrogliomas tend to infiltrate the frontal aslant tract, whereas astrocytomas tend to displace it.

INTRODUCTION: MR-tractography is increasingly used in neurosurgical practice to evaluate the anatomical relationships between glioma and nearby subcortical tracts. In some patients, the subcortical tracts seem displaced by the glioma, while in other patients, the subcortical tracts seem infiltrated without displacement. At this point, it is unknown whether these different patterns are related to tumor type. The aim of this exploratory study was to investigate whether tumor type is related to the spatial tractography pattern of the frontal aslant tract (FAT) in low-grade gliomas (LGGs). METHODS: In 64 IDH-mutated LGG patients, the FAT was generated using a pipeline for automatic tractography. In 41 patients, the glioma adjoined the FAT, and four blinded reviewers independently assessed the following two dichotomous categories (yes/no): (i) glioma displaces the tract, and (ii) glioma infiltrates the tract. RESULTS: Fisher's exact tests demonstrated strong and significant positive associations between displacement and astrocytomas (p = .002, φ = .497) and infiltration and oligodendrogliomas (p = .004, φ = .484). The interobserver agreement was good for both categories: (i) κ = 0.76 and (ii) κ = 0.71. CONCLUSION: High sensitivity but low specificity for displacement in astrocytomas demonstrates that in the case of an astrocytoma, the tract is most likely displaced, but that displacement in itself is not necessarily predictive for astrocytomas, as oligodendrogliomas may both infiltrate and displace a tract. Overall, these results demonstrate that oligodendrogliomas tend to infiltrate the nearby subcortical tract, whereas astrocytomas only tend to displace it.

Dual Task Performance Is Associated with Amyloidosis in Cognitively Healthy Adults.

BACKGROUND: Preclinical Alzheimer's disease (AD) provides an opportunity for the study and implementation of interventions and strategies aimed at delaying, mitigating, and preventing AD. While this preclinical state is an ideal target, it is difficult to identify efficiently and cost-effectively. Recent findings have suggested that cognitive-motor dual task paradigms may provide additional inference. OBJECTIVES: Investigate the relationship between dual task performance and amyloidosis, suggestive of preclinical Alzheimer's disease and whether dual task performance provides additional information beyond a cognitive composite, to help in the identification of amyloidosis. DESIGN: Cross-sectional. SETTING: Outpatient specialty brain health clinical research institution in the United States. PARTICIPANTS: 52 cognitively healthy adults. MEASUREMENTS: The data included demographics, amyloid standardized uptake value ratio obtained via florbetapir-PET, neuropsychological testing, apolipoprotien E genotype, and dual task performance measures. Data were analyzed via hierarchal multiple linear regression or logistic regression, controlling for age, education, and apolipoprotien E genotype. Receiver operating characteristic curves were plotted, and sensitivity and specificity calculated via 2x2 contingency tables. RESULTS: There was a moderate relationship (rs>.30) between motor and cognitive dual task effects and amyloid standardized uptake value ratio (ps<.042). A strong relationship (r=.58) was found between combined dual task effect, a measure of automaticity derived from dual task performance, and amyloid standardized uptake value ratio (p<.001). Additionally, combined dual task effect showed promise in its unique contributions to amyloid standardized uptake value ratio, accounting for 7.8% of amyloid standardized uptake value ratio variance beyond cognitive composite scores (p=.018). Additionally, when incorporated into the cognitive composite, combined dual task effect resulted in improved diagnostic accuracy for determining elevated amyloid standardized uptake value ratio, and increased the sensitivity and specificity of the cognitive composite. CONCLUSSION: Dual task performance using the combined dual task effect, a measure of automaticity, was a moderate predictor of cerebral amyloidosis, which suggests that it has utility in the screening and diagnosis of individuals for preclinical AD. Additionally, when combined with the cognitive composite, the combined dual task effect improves diagnostic accuracy. Further research is warranted.

Reconciling communication repertoires: navigating interactions involving persons with severe/profound intellectual disability, a classic grounded theory study.

BACKGROUND: A rights-based agenda, informed by the UNCRPD, that advocates person-centredness, inclusion, empowerment and self-determination is shaping service provision to people with intellectual disability (ID). Listening to their perspectives is fundamental to meeting these goals. However, communication with people with severe/profound ID is challenging and difficult. Therefore, this study aims to generate a theory that explains how people communicate with and understand each other in these interactions. METHODS: Classic grounded theory (CGT) methodology was used as it recognises that knowledge can be captured rather than interpreted. According to CGT, capturing rather than interpreting experiences strengthens findings, particularly in relation to participants with severe/profound ID. Concurrent theoretical sampling, data collection and analysis were undertaken. Twenty-two individuals participated in the study: 3 people with severe/profound ID and 19 people with whom they interact. Data were collected over a 9-month period and involved video recordings, field notes, individual and group interviews. Data were analysed using CGT methods of coding, constant comparison and memoing. RESULTS: The Theory of Reconciling Communication Repertoires was generated. Nurturing a sense of belonging emerged as the main concern and core category that is resolved by reconciling communication repertoires. A communication repertoire refers to the cache of communication skills a person has available to them. To reconcile repertoires is to harmonise or make them compatible with each other in order to communicate. Interactions are navigated through five stages: motivation to interact, connection establishment, reciprocally engaging, navigating understanding and confusion resolution. CONCLUSIONS: The Theory of Reconciling Communication Repertoires explains how interactions involving people with severe/profound ID are navigated. While this is a substantive rather than formal theory, it has the potential to inform practice, policy, management, education and research as it outlines how communication with people with severe/profound ID can take place to design, inform and plan person-centred care.

The Family Psychoeducation Fidelity Scale: Psychometric Properties.

This study examined psychometric properties and feasibility of the Family Psychoeducation (FPE) Fidelity Scale. Fidelity assessors conducted reviews using the FPE fidelity scale four times over 18 months at five sites in Norway. After completing fidelity reviews, assessors rated feasibility of the fidelity review process. The FPE fidelity scale showed excellent interrater reliability (.99), interrater item agreement (88%), and internal consistency (mean = .84 across four time points). By the 18-month follow-up, all five sites increased fidelity and three reached adequate fidelity. Fidelity assessors rated feasibility as excellent. The FPE fidelity scale has good psychometric properties and is feasible for evaluating the implementation of FPE programs. Trial registration ClinicalTrials.gov Identifier: NCT03271242.

Synapse formation in adult barrel cortex following naturalistic environmental enrichment.

Environmental enrichment paradigms in adult laboratory animals, consisting of physical, perceptual, and social stimulation, have been shown to affect synapse and cell morphology in sensory cortex and enhance learning ability, whereas enrichment, which is in harmony with the animal's natural habitat may have even greater implications for plasticity. Previous studies in our laboratory have shown that whisker stimulation induced the formation of synapses and spines in the corresponding barrel. In the present study adult C57/Bl6J female laboratory mice at 6 weeks of age were placed during 2 months in a protected enrichment enclosure in a forest clearing at the Chisti Les Biological Station, Tvier, Russia. We analyzed neuropil ultrastructure in the C2 barrel using serial-section electron microscopy on a total of eight mice (n=4 enriched, n=4 standard cagemate controls). Quantitative analyses of volumes of neuropil showed a significant increase in excitatory and inhibitory synapses on spines and excitatory synapses on dendritic shafts in the C2 barrel in the enriched group compared with standard cagemate controls. These results demonstrate that naturalistic experience alters the synaptic circuitry in layer IV of the somatosensory cortex, the first cortical relay of sensory information, leaving a lasting trace that may guide subsequent behavior.

Bilateral hematogenous Pseudomonas aeruginosa endophthalmitis after lung transplantation.

Pseudomonas aeruginosa commonly colonizes the airways of patients with cystic fibrosis (CF). However, the occurrence of bacteremia with metastatic infection to the eye causing endogenous endophthalmitis is very rare. In the setting of lung transplantation, the significance of P. aeruginosa bacteremia in patients with CF whose airways are colonized before transplantation is unknown. We report a case of bilateral P. aeruginosa endogenous endophthalmitis in a patient with CF after lung transplant without documented bacteremia. The patient presented with acute eye symptoms in the presence of a left atrial thrombus and the disease followed a rapidly progressive course requiring aggressive medical-surgical treatment. Typically P. aeruginosa endophthalmitis has been associated with a poor visual prognosis. However, with combined medical-surgical management this patient retained useful vision in one eye without having retinal detachment or requiring enucleation. Endogenous endophthalmitis should be considered in the differential diagnosis of ocular complaints in patients with CF after lung transplant.

Factors associated with breastfeeding at discharge and duration of breastfeeding.

OBJECTIVE: To identify determinants of the initiation and duration of breastfeeding amongst Australian women. METHODS: A prospective cohort study of 556 women in Perth, Western Australia and 503 women from the Darling Downs area, Queensland, Australia. RESULTS: Breastfeeding at discharge was most strongly associated with perceived paternal support of breastfeeding with an adjusted odds ratio of 9.13 (95% CI 4.83-17.26), using multivariate logistic regression analysis. Duration of breastfeeding was most strongly associated with the length of time a mother intended to breastfeed with an adjusted relative risk of 4.18 (95% CI 2.81-6.22) for > or = 4 months relative to < 4 months. CONCLUSIONS: Interventions which aim to increase the length of time a woman intends to breastfeed, and which highlight the role of the father in successful breastfeeding, are recommended to help achieve recommended targets for breastfeeding initiation and duration.

Psychosocial factors associated with the abandonment of breastfeeding prior to hospital discharge.

A prospective study of 556 women from Perth, Western Australia, and 503 women from the Darling Downs area, Queensland, Australia, was conducted to identify factors associated with the abandonment of breastfeeding prior to hospital discharge. In total, 88% of women initiated breastfeeding, but 5% discontinued breastfeeding while still in the hospital. Discontinuation of breastfeeding prior to discharge was associated with a number of psychosocial factors, namely, infant feeding method being chosen after becoming pregnant, a perception by the mother that the infant's father either preferred formula feeding or was ambivalent about how the infant was fed, and whether the mother's own mother had ever breastfed. Judicious questioning prenatally regarding a women's commitment to, social support for, and prior exposure to breastfeeding will help identify those women most at risk of abandoning breastfeeding prematurely. Such women should be targeted for additional support while in the hospital.

The theory-practice gap in nursing: the role of the nurse teacher.

The increasingly complex requirements of today's nursing practitioners, have been accompanied by demands on nurse educators to look at new ways to facilitate learning in the clinical area (Camiah 1996). In recent years nursing education has undergone a period of major change in many countries through integrating with universities. While nurse educators are striving to respond to changes in education the dichotomy between the theoretical input taught in the classroom and what is practised or experienced on the wards remains a problem (Ashworth & Longmate 1993, Ferguson & Jinks 1994). Dale (1994) postulates that theory provides the basis for understanding the reality of nursing, it would seem reasonable, therefore, to assume that the content studied in the classroom correlates with what the student experiences on the ward. It should also follow that if a gap exists between theory and practice, efforts should be taken for its reduction (Rafferty et al. 1996). According to MacNeil (1997) many initiatives have been introduced in an effort to bridge the theory-practice gap and these have focused around the role of the nurse teacher. These changes in education are redefining the role of the nurse teacher, therefore, the part that they currently play and will play in the future needs to be carefully considered (Phillips et al. 1996b). The aim of this paper is to provide an overview of the literature on the theory-practice divide in nursing. First, some of the reasons cited for its existence will be explored. Second, suggested ways of bridging the divide will be considered focusing on the role of the nurse teacher.

Ulnar neuropathy as a complication of macular hole surgery.

OBJECTIVE: To report a series of patients manifesting ulnar neuropathy as an extraocular complication following macular hole surgery and facedown positioning. METHODS: Retrospective chart review of 7 patients identified by the operating surgeon as developing ulnar neuropathy during the immediate postoperative period after undergoing vitrectomy surgery with fluid-gas exchange for macular hole followed by at least 1 week of strict facedown positioning. RESULTS: All 7 patients developed symptoms of ulnar neuropathy, including paresthesias, dysesthesias, pain, weakness, and muscle atrophy. Signs included abnormal electromyogram, prolonged nerve conduction velocities, and impaired neurologic clinical test results in patients examined. Symptoms did not resolve with cessation of facedown positioning, and with follow-up ranging from 3 to 24 months all patients had persistent symptoms. All patients had positioned themselves with their arms continuously flexed. Three of 7 patients had placed pressure directly on their bent elbows. CONCLUSIONS: Ulnar neuropathy is an extraocular complication of macular hole surgery that can be attributed to arm position during postoperative facedown positioning. Surgeons performing macular hole surgery should caution their patients to minimize the amount of time spent with their elbows in a flexed position. Particular effort should be made to minimize pressure on the bent elbow.

Vibrissae-evoked behavior and conditioning before functional ontogeny of the somatosensory vibrissae cortex.

The following experiments determined that the somatosensory whisker system is functional and capable of experience-dependent behavioral plasticity in the neonate before functional maturation of the somatosensory whisker cortex. First, unilateral whisker stimulation caused increased behavioral activity in both postnatal day (P) 3-4 and P8 pups, whereas stimulation-evoked cortical activity (14C 2-deoxyglucose autoradiography) was detectable only in P8 pups. Second, neonatal rat pups are capable of forming associations between whisker stimulation and a reinforcer. A classical conditioning paradigm (P3-P4) showed that the learning groups (paired whisker stimulation-shock or paired whisker stimulation-warm air stream) exhibited significantly higher behavioral responsiveness to whisker stimulation than controls. Finally, stimulus-evoked somatosensory cortical activity during testing [P8; using 14C 2-deoxyglucose (2-DG) autoradiography] was assessed after somatosensory conditioning from P1-P8. No learning-associated differences in stimulus-evoked cortical activity were detected between learning and nonlearning control groups. Together, these experiments demonstrate that the whisker system is functional in neonates and capable of experience-dependent behavioral plasticity. Furthermore, in contrast to adult somatosensory classical conditioning, these data suggest that the cortex is not required for associative somatosensory learning in neonates.

Nutrition in early life: somatic growth and serum lipids.

This paper addresses the questions of whether early nutritional experience affects later somatic growth, the growth of the adipose tissue, or the levels of serum lipids among well-nourished children. The analyses are based on data from three prospective studies. Postnatal nutrition and growth: there were differences in growth between breast-fed and formula-fed children. There was no association between linear growth and differences in food energy or macronutrient intake. Birth size and postnatal growth: there was no association between ponderal index (PI) at birth and body mass index (BMI) in the second year. For boys, the PI at 3 and 6 months of age was significantly positively correlated with BMI at the ages of 8 and 15 years, but not for girls. Childhood growth and lipids: there was no association between lipids at the age of 8 years and either birth weight or length, but children who had had a low PI at birth had higher lipid levels at the age 8 years. A positive association was found between serum lipids and abdominal fat and BMI. We conclude that, although early diet may influence growth rate beyond infancy, the evidence for fat patterning resulting from differences in fetal or early postnatal nutrition is still open to question.

Norepinephrine and associative conditioning in the neonatal rat somatosensory system.

Neonatal rats, aged postnatal days 3-4, were trained in a somatosensory associative conditioning task involving temporal correlation of facial vibrissa stimulation and aversive shock. This training resulted in a subsequent conditioned behavioral activation/arousal response to vibrissa stimulation alone, compared to non-learning control pups trained with random vibrissa-shock presentations. The acquisition of the conditioned response was blocked by systemic injections of the NE beta-receptor antagonist propranolol in a dose-dependent manner. In a second study, vibrissa stimulation was paired with systemic injections of the NE beta-receptor agonist isoproterenol. Association of vibrissa stimulation with beta-receptor activation resulted in subsequent conditioned responses to vibrissa stimulation alone, in a dose-dependent manner. Together, these results suggest that early associative somatosensory conditioning requires and involves NE in a manner similar to that previously demonstrated for early olfactory learning.

Comparison of oversensing during bradycardia pacing in two types of implantable cardioverter-defibrillator systems.

BACKGROUND: During bradycardia pacing in Ventritex Cadence (Models V-100 and V-110) implantable cardioverter-defibrillators, amplifier gain is maximal and oversensing and false tachyarrhythmia detection have been reported. Newer Ventritex devices (Cadet, Model V-115 and Contour, Model V-145) have a modified automatic gain control that may minimize oversensing. METHODS AND RESULTS: We prospectively studied 50 patients (22 with Cadence, 28 with Cadet or Contour). Electrograms were evaluated for oversensing during bradycardia pacing. The bradycardia pacing refractory period required to prevent oversensing of T waves of paced beats and the time and number of beats required to achieve minimum gain after cessation of pacing were assessed. The bradycardia pacing refractory period could be left at its default setting of 350 ms in only 15 (30%) of 50 patients. The mean bradycardia pacing refractory period required to avoid oversensing of paced T waves was 386+/-32 ms. During pacing, oversensing of nonpaced T waves was seen in 12 (24%) devices, with similar incidence in Cadence devices (18%) and Cadet and Contour devices (29%, p = not significant). The time and number of beats to achieve minimum gain after pacing were longer in Cadence devices (19.0+/-4.5 vs 4.6+/-1.2 sec; 21.3+/-3.3 vs 5.0+/-0.4 beats, both p < 0.001). CONCLUSIONS: The incidence of oversensing at maximum gain is similar in both types of devices, but more rapid changes in autogain levels in the newer devices may reduce the likelihood of false tachyarrhythmia detection.

Feeding of a well-cooked beef diet containing a high heterocyclic amine content enhances colon and stomach carcinogenesis in 1,2-dimethylhydrazine-treated rats.

Epidemiologic studies have linked the consumption of red meat and the consumption of highly browned meats containing high levels of heterocyclic aromatic amines (HCAs) to increased risk of colorectal cancer or polyps. The present study determined the effects of long-term feeding of beef-containing diets with low and high levels of HCAs (in the context of a low or high beef tallow diet) on a standard 1,2-dimethylhydrazine (DMH)-induced colon tumorigenesis protocol. Very lean beef was cooked by a variety of methods at different temperatures, and the levels of the major HCAs (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline, and 2-amino-1-methyl-6-phenylimidazo[4,5-f]pyridine) were measured by high-performance liquid chromatography. Diets incorporating beef containing low or high levels of HCAs were fed for 12 weeks, during which DMH was administered to induce colon tumors, followed by various dietary regimens as promotional stimuli. Feeding of a beef diet high in HCAs resulted in more DMH-induced colon adenocarcinomas, but only in the context of a low-fat diet. The high-HCA diets increased stomach tumors in all DMH-treated rats. An apparent interaction of high HCA with a high fat level reduced the colon tumor incidence and tumor numbers in those diets containing both factors. These results support the epidemiologic data linking well-cooked meat to increased risk for colon and stomach cancer, but the role of dietary fat level remains puzzling.

Radiofrequency catheter ablation of idiopathic left ventricular tachycardia originating in the left anterior fascicle.

Radiofrequency catheter ablation has been used to treat idiopathic left ventricular tachycardia with high success rates. The majority of reported cases have exhibited the typical findings of right bundle branch block morphology with left axis deviation and originate from within or near the left posterior fascicle. We report a case of idiopathic left ventricular tachycardia originating from within or near the left anterior fascicle, which was successfully ablated using a local Purkinje potential as a guide.

Electrophysiological effects of acute dilatation in the isolated rabbit heart: cycle length-dependent effects on ventricular refractoriness and conduction velocity.

BACKGROUND: Acute ventricular dilatation has important electrophysiological effects: Dilatation shortens action potential duration and refractoriness without an apparent effect on conduction velocity. These effects have been implicated as a potential mechanism of arrhythmias in patients with congestive failure. Because the influence of cycle length on these phenomena has not been studied, we examined the effects of dilatation during ventricular pacing at cycle lengths from 1000 to 150 ms. METHODS AND RESULTS: Thin epicardial layers were created in isolated, perfused rabbit left ventricles (n=7). A fluid filled latex balloon was secured in the left ventricle to dilate the left ventricle. Mapping was performed with 248 epicardial electrodes. Longitudinal conduction velocity (76+/-1 cm/s; mean+/-SEM) and transverse conduction velocity (26+/-1 cm/s) were not influenced by dilatation at any cycle length. In contrast, the effects of dilatation in decreasing left ventricular effective refractory period (ERP) were significantly greater at shorter drive cycle lengths: The decrease in ERP was 2+/-2 ms (a 1% change) at a drive cycle length of 1000 ms and 18+/-4 ms (a 20% change) at a drive cycle length of 150 ms. In 10 additional intact, isolated perfused rabbit hearts, dilatation decreased ERP to a greater degree during 250 ms drive cycle length pacing than during pacing at 400 ms (25+/-4 versus 16+/-3 ms; P=.01). CONCLUSIONS: Acute dilatation exaggerates the normal rate-dependent shortening of refractoriness but does not influence transverse or longitudinal conduction velocity. This observation suggests that the electrophysiological effects of acute dilatation may be greater during tachycardia than at slower cycle lengths. This may have implications for arrhythmias in patients with congestive heart failure.