Functional Dizziness as a Spatial Cognitive Dysfunction

(1) Background: Persistent postural-perceptual dizziness (PPPD) is a common chronic dizziness disorder with an unclear pathophysiology. It is hypothesized that PPPD may involve disrupted spatial cognition processes as a core feature. (2) Methods: A cohort of 19 PPPD patients underwent psycho-cognitive testing, including assessments for anxiety, depression, memory, attention, planning, and executive functions, with an emphasis on spatial navigation via a virtual Morris water maze. These patients were compared with 12 healthy controls and 20 individuals with other vestibular disorders but without PPPD. Vestibular function was evaluated using video head impulse testing and vestibular evoked myogenic potentials, while brain magnetic resonance imaging was used to exclude confounding pathology. (3) Results: PPPD patients demonstrated unique impairments in allocentric spatial navigation (as evidenced by the virtual Morris water maze) and in other high-demand visuospatial cognitive tasks that involve executive functions and planning, such as the Towers of London and Trail Making B tests. A factor analysis highlighted spatial navigation and advanced visuospatial functions as being central to PPPD, with a strong correlation to symptom severity. (4) Conclusions: PPPD may broadly impair higher cognitive functions, especially in spatial cognition. We discuss a disruption in the creation of enriched cognitive spatial maps as a possible pathophysiology for PPPD.

Lateral Prefrontal Theta Oscillations Reflect Proactive Cognitive Control Impairment in Males With Attention Deficit Hyperactivity Disorder

Attention Deficit Hyperactivity Disorder (ADHD) is a common neuropsychiatric disorder in which children present prefrontal cortex (PFC) related functions deficit. Proactive cognitive control is a process that anticipates the requirement of cognitive control and crucially depends on the maturity of the PFC. Since this process is important to ADHD symptomatology, we here test the hypothesis that children with ADHD have proactive cognitive control impairments and that these impairments are reflected in the PFC oscillatory activity. We recorded EEG signals from 29 male children with ADHD and 25 typically developing (TD) male children while they performed a Go-Nogo task, where the likelihood of a Nogo stimulus increased while a sequence of consecutive Go stimuli elapsed. TD children showed proactive cognitive control by increasing their reaction time (RT) concerning the number of preceding Go stimuli, whereas children with ADHD did not. This adaptation was related to modulations in both P3a potential and lateral prefrontal theta oscillation for TD children. Children with ADHD as a group did not demonstrate either P3a or theta modulation. But, individual variation in theta activity was correlated with the ADHD symptomatology. The results depict a neurobiological mechanism of proactive cognitive control impairments in children with ADHD.

Neural markers of social and monetary rewards in children with Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

Recent theories of decision making propose a shared value-related brain mechanism for encoding monetary and social rewards. We tested this model in children with Attention-Deficit/Hyperactivity Disorder (ADHD), children with Autism Spectrum Disorder (ASD) and control children. We monitored participants’ brain dynamics using high density-electroencephalography while they played a monetary and social reward tasks. Control children exhibited a feedback Error-Related Negativity (fERN) modulation and Anterior Cingulate Cortex (ACC) source activation during both tasks. Remarkably, although cooperation resulted in greater losses for the participants, the betrayal options generated greater fERN responses. ADHD subjects exhibited an absence of fERN modulation and reduced ACC activation during both tasks. ASD subjects exhibited normal fERN modulation during monetary choices and inverted fERN/ACC responses in social options than did controls. These results suggest that in neurotypicals, monetary losses and observed disloyal social decisions induced similar activity in the brain value system. In ADHD children, difficulties in reward processing affected early brain signatures of monetary and social decisions. Conversely, ASD children showed intact neural markers of value-related monetary mechanisms, but no brain modulation by prosociality in the social task. These results offer insight into the typical and atypical developments of neural correlates of monetary and social reward processing.

Ground and excited states of NH4: Electron propagator and quantum defect analysis

Vertical excitation energies of the Rydberg radical NH4 are inferred from ab initio electron propagator calculations on the electron affinities of NH4+. The adiabatic ionization energy of NH4 is evaluated with coupled-cluster calculations. These predictions provide optimal parameters for the molecular-adapted quantum defect orbital method, which is used to determine Einstein emission coefficients and radiative lifetimes. Comparisons with spectroscopic data and previous calculations are discussed.

Clients' perceptions of the benefits of reflexology on their quality of life

Awareness has increased among health-care professionals, patients and the general public of the importance of an holistic approach to cancer care. Psychosocial interventions, including complementary therapies, may help to improve the quality of life (QoL) of people with cancer by helping to reduce the distress associated with the diagnosis and treatment of cancer and by facilitating improved psychological adjustment to the experience of cancer. The following article presents anecdotal findings at ARC Cancer Support Centre Dublin, Ireland, of clients' perceptions of the benefits of reflexology interventions on their QoL. Reflexology interventions were perceived to impact positively upon clients' levels of impairment and functional status, including physical and psychological function, with implications for general health perceptions. The paper discusses how these findings might form the basis of further, more rigourous evaluation of the benefits of reflexology for people with cancer at ARC Cancer Support Centre.

Activation of flavin-containing oxidases underlies light-induced production of H2O2 in mammalian cells

Violet-blue light is toxic to mammalian cells, and this toxicity has been linked with cellular production of H2O2. In this report, we show that violet-blue light, as well as UVA, stimulated H2O2 production in cultured mouse, monkey, and human cells. We found that H2O2 originated in peroxisomes and mitochondria, and it was enhanced in cells overexpressing flavin-containing oxidases. These results support the hypothesis that photoreduction of flavoproteins underlies light-induced production of H2O2 in cells. Because H2O2 and its metabolite, hydroxyl radicals, can cause cellular damage, these reactive oxygen species may contribute to pathologies associated with exposure to UVA, violet, and blue light. They may also contribute to phototoxicity often encountered during light microscopy. Because multiphoton excitation imaging with 1,047-nm wavelength prevented light-induced H2O2 production in cells, possibly by minimizing photoreduction of flavoproteins, this technique may be useful for decreasing phototoxicity during fluorescence microscopy.

Comparative ultrastructure of plasmodesmata of Chara and selected bryophytes: toward an elucidation of the evolutionary origin of plant plasmodesmata

We have used transmission electron microscopy to examine plasmodesmata of the charophycean green alga Chara zeylanica, and of the putatively early divergent bryophytes Monoclea gottschei (liverwort), Notothylas orbicularis (hornwort), and Sphagnum fimbriatum (moss), in an attempt to learn when seed plant plasmodesmata may have originated. The three bryophytes examined have desmotubules. In addition, Monoclea was found to have branched plasmodesmata, and plasmodesmata of Sphagnum displayed densely staining regions around the neck region, as well as ring-like wall specializations. In Chara, longitudinal sections revealed endoplasmic reticulum (ER) that sometimes appeared to be associated with plasmodesmata, but this was rare, despite abundant ER at the cell periphery. Across all three fixation methods, cross-sectional views showed an internal central structure, which in some cases appeared to be connected to the plasma membrane via spoke-like structures. Plasmodesmata were present even in the incompletely formed reticulum of forming cell plates, from which we conclude that primary plasmodesmata are formed at cytokinesis in Chara zeylanica. Based on these results it appears that plasmodesmata of Chara may be less specialized than those of seed plants, and that complex plasmodesmata probably evolved in the ancestor of land plants before extant lineages of bryophytes diverged.

Follow-up of abnormal Papanicolaou smears in a hospital-based adolescent clinic

STUDY OBJECTIVE

To present data on the spectrum of abnormal Papanicolaou (PAP) smears in adolescents and to determine factors that influence compliance with recommendations to return for repeat PAP smears or for colposcopic examination.

DESIGN

Retrospective chart review with follow-up telephone calls to patients who did not follow recommendations for colposcopy.

SETTING

Adolescents receiving health care in a hospital-based adolescent clinic.

PARTICIPANTS

Patients with abnormal PAP smears between July 1, 1994 and June 30, 1995.

MAIN OUTCOME MEASURES

Compliance with follow-up for abnormal PAP smears including referral to the colposcopy clinic, and the results of repeat PAP smears and colposcopy.

RESULTS

Of 888 adolescents undergoing PAP smear evaluation 119 (13.4%) had an abnormal PAP smear during the study year (index PAP). The results of the index PAP were 97 (81.5%) atypia and 22 (18.5%) squamous intraepithelial lesion low grade (SIL LG). The index PAP was the first abnormal PAP smear for 92 of the patients (77%); 27 had one or more previous abnormal PAP smears (18 atypia, 7 SIL LG, 2 SIL high grade [HG]), and 13 had been referred for colposcopy in the past. For 76 of 92 patients with atypia on index PAP (84%), the index PAP was the first abnormal PAP smear. Of these 76 patients, 51 had a second PAP smear: 27 (53%) were normal, 13 (25%) atypia, and 11 (22%) SIL LG. Sixty patients were referred to the colposcopy clinic, but only 37 actually kept the colposcopy appointment despite outreach. The only significant factor for obtaining colposcopy was a visit to the Adolescent Clinic after notification of the abnormal PAP smear result and before the colposcopy appointment; 79% of those who had a visit obtained colposcopy compared with 45% of those who did not have such a visit (p = 0.007). There were no significant differences by race, insurance status, age, PAP smear result, previous referral for colposcopy, or number of reminders with compliance with recommendations for repeat PAP smears or colposcopy.

CONCLUSIONS

Although a sizable proportion of adolescents with abnormal PAP smears have significant pathology on repeat PAP smears, adolescents with abnormal PAP smears have a high failure rate in keeping appointments for follow-up PAP smears and colposcopy. Interventions that target all adolescents with abnormal PAP smears need to be designed and tested to aid follow-up.

Scores on the Wechsler Intelligence Scale for Children-Third Edition and Woodcock-Johnson Tests of Achievement-Revised for a sample of children with emotional handicaps

Because there is little available research, this study examined the associations between scores on the Wechsler Intelligence Scale for Children-Third Edition and the Woodcock-Johnson Tests of Achievement-Revised for 85 children with diagnosed emotional handicaps. Analysis indicated associations were significant.

Dysfunctional uterine bleeding in adolescents

Dysfunctional uterine bleeding (DUB) is a common presenting problem for adolescents. New data have emerged on the frequency of the pathologic causes for menorrhagia and the potential to use new therapies such as gonadotropin-releasing hormone analogues. DUB is defined as abnormal vaginal bleeding without an identifiable pathologic condition. In adolescents, DUB is most often due to the anovulatory cycles that result from an immature hypothalamic-pituitary-ovarian axis. Although most adolescents will develop normal, regular menstrual cycles, a significant number may require gynecologic follow-up for persistent abnormal vaginal bleeding. Thus, optimal management of DUB requires a systematic diagnosis and therapeutic approach. This article reviews the pathophysiology, diagnostic evaluation, treatment options, and outcome of DUB in adolescents.