Polariton Condensation in Gap-Confined States of Photonic Crystal Waveguides

The development of patterned multiquantum well heterostructures in GaAs/AlGaAs waveguides has recently made it possible to achieve exciton-polariton condensation in a topologically protected bound state in the continuum (BIC). Polariton condensation was shown to occur above a saddle point of the two-dimensional polariton dispersion in a one-dimensional photonic crystal waveguide. A rigorous analysis of the condensation phenomenon in these systems, as well as the role of the BIC, is still missing. In the present Letter, we theoretically and experimentally fill this gap by showing that polariton confinement resulting from the negative effective mass and the photonic energy gap in the dispersion play a key role in enhancing the relaxation toward the condensed state. In fact, our results show that low-threshold polariton condensation is achieved within the effective trap created by the exciting laser spot, regardless of whether the resulting confined mode is long-lived (polariton BIC) or short-lived (lossy mode). In both cases, the spatial quantization of the polariton condensate and the threshold differences associated to the corresponding state lifetime are measured and characterized. For a given negative mass, a slightly lower condensation threshold from the polariton BIC mode is found and associated to its reduced radiative losses, as compared to the lossy one.

Enhancement of Parametric Effects in Polariton Waveguides Induced by Dipolar Interactions

Exciton-polaritons are hybrid light-matter excitations arising from the nonperturbative coupling of a photonic mode and an excitonic resonance. Behaving as interacting photons, they show optical third-order nonlinearities providing effects such as optical parametric oscillation or amplification. It has been suggested that polariton-polariton interactions can be greatly enhanced by inducing aligned electric dipoles in their excitonic part. However, direct evidence of a true particle-particle interaction, such as superfluidity or parametric scattering, is still missing. In this Letter, we demonstrate that dipolar interactions can be used to enhance parametric effects such as self-phase modulation in waveguide polaritons. By quantifying these optical nonlinearities, we provide a reliable experimental measurement of the direct dipolar enhancement of polariton-polariton interactions.

A preliminary study to investigate the prevalence of pain in international event riders during competition, in the United Kingdom

The aim of the study was to investigate the prevalence of riders at the international levels in eventing, competing with pain, the location of their pain, factors affecting their pain and whether they perceived this pain to have an effect on their performance. 331 questionnaires were completed by international event riders (FEI CCI*, CCI**, CIC***) at the Hartpury International Horse Trials, UK, to establish the prevalence of riders competing with pain. 96% of international event riders competed while experiencing pain, 76% of riders stated that this pain was in the neck, upper back or shoulders. All female riders reported pain, giving a significant correlation between gender and pain (X=-0.479, P=0.006). 55% of riders felt their pain affected their riding performance, giving an odds ratio of 1.14, compared to those riders who felt their pain did not effect their performance. Pain was perceived to influence performance by affecting fatigue, their concentration, and anxiety levels. 96% of riders reporting pain used medication to alleviate their symptoms. This high incidence of international event riders who compete with pain, particularly back pain, could be problematic given the longevity of a rider’s career, which can span over four decades and could potentially increase the risk of a serious or fatal fall in the cross-country phase. This research reports rider’s perceptions and self-reported pain and management options, which may affect the data. Further research is needed to establish the causes of back pain and appropriate management strategies.

A Qualitative Exploration of Community-Based Organization Programs, Resources, and Training to Promote Adolescent Sexual Health

BACKGROUND

Youth development professionals (YDPs) working at community-based organizations (CBOs) can promote adolescent sexual health through programs. This study explored the programs and resources that youth access at CBOs and training YDPs receive.

METHODS

Twenty-one semi-structured interviews were conducted with YDPs. Qualitative content analyses were conducted using NVivo.

RESULTS

Most YDPs (n = 15, 71.4%) described sexuality-related programs for youth. Some YDPs provided informal information (n = 11, 52.4%) and/or referrals for youth (n = 6, 28.6%). Few YDPs (n = 8, 38.1%) were trained to address adolescent sexuality, but some (n = 10, 47.6%) sought outside resources.

CONCLUSIONS

YDPs have a unique opportunity to improve adolescent sexual health and sexuality. Five considerations for organizations that develop programs and training for CBOs are suggested.

Random flips of electric field in microwave-induced states with spontaneously broken symmetry

In a two-dimensional electron system subject to microwaves and a magnetic field, photovoltages emerge. They can be separated into two components originating from built-in electric fields and electric field domains arising from spontaneous symmetry breaking. The latter occurs in the zero resistance regime only and manifests itself in pulsed behavior, synchronous across the sample. The pulses show sign reversal. This implies a flip of the field in each domain, consistent with the existence of two equally probable electric field domain configurations due to the spontaneous symmetry breaking.

Factors affecting the outcome of fractures of the femoral neck in children and adolescents: a systematic review

Fractures of the femoral neck in children are rare, high-energy injuries with high complication rates. Their treatment has become more interventional but evidence of the efficacy of such measures is limited. We performed a systematic review of studies examining different types of treatment and their outcomes, including avascular necrosis (AVN), nonunion, coxa vara, premature physeal closure (PPC), and Ratliff's clinical criteria. A total of 30 studies were included, comprising 935 patients. Operative treatment and open reduction were associated with higher rates of AVN. Delbet types I and II fractures were most likely to undergo open reduction and internal fixation. Coxa vara was reduced in the operative group, whereas nonunion and PPC were not related to surgical intervention. Nonunion and coxa vara were unaffected by the method of reduction. Capsular decompression had no effect on AVN. Although surgery allows a more anatomical union, it is uncertain whether operative treatment or the type of reduction affects the rate of AVN, nonunion or PPC, because more severe fractures were operated upon more frequently. A delay in treatment beyond 24 hours was associated with a higher incidence of AVN.

Gallbladder cancer: past, present and an uncertain future

Although gallbladder cancer (GBC) is the most common malignancy of the biliary tract, its relatively low incidence and confounding symptomatology result in advanced disease at the time presentation, contributing to the poor prognosis and decreased survival associated with this disease. It is therefore increasingly important to understand its pathogenesis and risk factors to allow for the earliest possible diagnosis. To date, gallbladder cancer is poorly understood compared to other malignancies, and is still most commonly discovered incidentally after cholecystectomy. Moreover, while much is known about biliary neoplasms as a whole, understanding the clinical and molecular nuances of GBC as a separate disease process will prove a cornerstone in the development of early intervention, potential screening and overall more effective treatment strategies. The present work reviews the most current understanding of the pathogenesis, diagnosis, staging and natural history of GBC, with additional focus on surgical treatment. Further, review of current adjuvant therapies for unresectable and advanced disease as well as prognostic factors provide fertile ground for the development of future studies which will hopefully improve treatment outcomes and affect overall survival for this highly morbid, poorly understood malignancy.

Sarcopenia: etiology, clinical consequences, intervention, and assessment

The aging process is associated with loss of muscle mass and strength and decline in physical functioning. The term sarcopenia is primarily defined as low level of muscle mass resulting from age-related muscle loss, but its definition is often broadened to include the underlying cellular processes involved in skeletal muscle loss as well as their clinical manifestations. The underlying cellular changes involve weakening of factors promoting muscle anabolism and increased expression of inflammatory factors and other agents which contribute to skeletal muscle catabolism. At the cellular level, these molecular processes are manifested in a loss of muscle fiber cross-sectional area, loss of innervation, and adaptive changes in the proportions of slow and fast motor units in muscle tissue. Ultimately, these alterations translate to bulk changes in muscle mass, strength, and function which lead to reduced physical performance, disability, increased risk of fall-related injury, and, often, frailty. In this review, we summarize current understanding of the mechanisms underlying sarcopenia and age-related changes in muscle tissue morphology and function. We also discuss the resulting long-term outcomes in terms of loss of function, which causes increased risk of musculoskeletal injuries and other morbidities, leading to frailty and loss of independence.

Comparative genomics of the lactic acid bacteria

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

Transition from single-mode to multimode operation of an injection-seeded pulsed optical parametric oscillator

Optical-heterodyne measurements are made on ~842-nm signal output of an injection-seeded optical parametric oscillator (OPO) based on periodically poled KTiOPO4 pumped at 532 nm by long (~27-ns) pulses from a Nd:YAG laser. At low pump energies (</= 2.5 times the free-running threshold), the narrowband tunable OPO output is single-longitudinal-mode (SLM) and frequency chirp can be <10 MHz, much less than the transform-limited optical bandwidth (~17.5 MHz). We explore the transition from SLM operation to multimode operation as pump energy or phase mismatch are increased, causing unseeded cavity modes to build up later in the pulse.

Apertureless near-field Raman spectroscopy

We report on the tip-enhanced Raman spectra of C60 obtained on a custom-built apertureless scanning near-field optical microscope. A commercial atomic force microscope tip coated with 100 nm thickness of gold was used to enhance locally the Raman signal and permit topographic and spectral information to be acquired simultaneously. We present preliminary data which demonstrate the tip enhancement effect using C60 as a test sample.

Under-reporting of erectile dysfunction among men with unrelated urologic conditions

To evaluate the incidence of erectile dysfunction (ED) in men with unrelated urologic conditions paying special attention to the reasons for patient under-reporting. We asked 500 consecutive men over age 50 visiting their urologist's office for problems unrelated to ED, whether or not they had any difficulty with their potency. Those who gave a positive response were then asked to complete a questionnaire to assess their reasons for under-reporting and whether they had had any previous discussions with their primary-care physicians regarding their sexual function. Out of 500 men, 218 (44%) reported experiencing some degree of ED. Reasons for failure to discuss ED with their urologist included: 161 out of 218 (74%) were embarrassed; 27 out of 218 (12%) felt that ED was a natural part of aging; 20 out of 218 (9%) were unaware that urologists dealt with the problem of ED; and 10 out of 218 (5%) did not consider the problem worthy of attention. Only 48 of the 218 men with ED reported having previous discussions about their problem with their primary-care physicians. Of the 170 patients who did not report having such discussions, 140 (82%) reported that they would have liked their primary-care physician to have initiated a discussion of ED during their routine visits. In conclusion. a significant percentage of older men with some unrelated urologic complaint also suffer from some degree of ED and remain undiagnosed unless specifically questioned about this problem. By far, the most common reason for under-reporting of ED was patient embarrassment. While urologists are able to elicit information regarding erectile function on specific questioning, patients appear comfortable and willing to discuss their potency with primary-care physicians.

When your patient can no longer live independently: a guide to supporting the patient and family

This article uses a case study format to illustrate the Expanded Family Life Cycle Theory of Carter and McGoldrick (1999). This theory provides nurses and other health care providers with tools for assessing and planning care for older adults facing stressful life transitions. The individual and family are assessed as a unit embedded within their community. This multicontextual framework is applied to an elderly woman's transition from independent living to supervised living in a facility and illustrates the ease of use for practicing nurses. Suggestions are also offered to assist health care providers in supporting older adults and their families in making this significant transition.

Paper-like electronic displays: large-area rubber-stamped plastic sheets of electronics and microencapsulated electrophoretic inks

Electronic systems that use rugged lightweight plastics potentially offer attractive characteristics (low-cost processing, mechanical flexibility, large area coverage, etc.) that are not easily achieved with established silicon technologies. This paper summarizes work that demonstrates many of these characteristics in a realistic system: organic active matrix backplane circuits (256 transistors) for large ( approximately 5 x 5-inch) mechanically flexible sheets of electronic paper, an emerging type of display. The success of this effort relies on new or improved processing techniques and materials for plastic electronics, including methods for (i) rubber stamping (microcontact printing) high-resolution ( approximately 1 microm) circuits with low levels of defects and good registration over large areas, (ii) achieving low leakage with thin dielectrics deposited onto surfaces with relief, (iii) constructing high-performance organic transistors with bottom contact geometries, (iv) encapsulating these transistors, (v) depositing, in a repeatable way, organic semiconductors with uniform electrical characteristics over large areas, and (vi) low-temperature ( approximately 100 degrees C) annealing to increase the on/off ratios of the transistors and to improve the uniformity of their characteristics. The sophistication and flexibility of the patterning procedures, high level of integration on plastic substrates, large area coverage, and good performance of the transistors are all important features of this work. We successfully integrate these circuits with microencapsulated electrophoretic "inks" to form sheets of electronic paper.

Risk-resistance adaptation model for caregivers and their children with sickle cell syndromes

This investigation examined the risk-resistance adaptation model for children with sickle cell disease and their primary caregivers. Participants were 55 children, ranging in age from 5 to 16 years with a mean age of 9 years 2 months, diagnosed with sickle cell disease and their primary caregivers, recruited from a university medical center. Measures included adjustment (i.e. primary caregiver and child adjustment), risk factors (i.e. disease and disability, functional independence, and psychosocial stressors), resistance factors (i.e. intrapersonal health locus of control, social-ecological), and stress processing (coping). Primary caregivers' adjustment was associated with developmental coping, changeR2 = .08, and child adaptation was associated with an internal health locus of control, changeR2 = .22. An indirect effect of primary caregivers' coping on child adjustment was found through influence on primary caregivers' adjustment, changeR2 = .11. The findings support research among other chronically ill populations that suggests an association between coping and disease adjustment. The results were interpreted to support the use of theoretically driven models in predicting the adaptation of children with chronic illness and adjustment in their caregivers.

Effects of training on attention to acoustic cues

Learning new phonetic categories in a second language may be thought of in terms of learning to focus one's attention on those parts of the acoustic-phonetic structure of speech that are phonologically relevant in any given context. As yet, however, no study has demonstrated directly that training can shift listeners' attention between acoustic cues given feedback about the linguistic phonetic category alone. In this paper we discuss the results of a training study in which subjects learned to shift their attention from one acoustic cue to another using only category-level identification as feedback. Results demonstrate that training redirects listeners' attention to acoustic cues and that this shift of attention generalizes to novel (untrained) phonetic contexts.

Time-dependent stimulation by aldosterone of blocker-sensitive ENaCs in A6 epithelia

To study and define the early time-dependent response (< or = 6 h) of blocker-sensitive epithelial Na+ channels (ENaCs) to stimulation of Na+ transport by aldosterone, we used a new modified method of blocker-induced noise analysis to determine the changes of single-channel current (iNa) channel open probability (Po), and channel density (NT) under transient conditions of transport as measured by macroscopic short-circuit currents (Isc). In three groups of experiments in which spontaneous baseline rates of transport averaged 1.06, 5.40, and 15.14 microA/cm2, stimulation of transport occurred due to increase of blocker-sensitive channels. NT varied linearly over a 70-fold range of transport (0.5-35 microA/cm2). Relatively small and slow time-dependent but aldosterone-independent decreases of Po occurred during control (10-20% over 2 h) and aldosterone experimental periods (10-30% over 6 h). When the Po of control and aldosterone-treated tissues was examined over the 70-fold extended range of Na+ transport, Po was observed to vary inversely with Isc, falling from approximately 0.5 to approximately 0.15 at the highest rates of Na+ transport or approximately 25% per 3-fold increase of transport. Because decreases of Po from any source cannot explain stimulation of transport by aldosterone, it is concluded that the early time-dependent stimulation of Na+ transport in A6 epithelia is due exclusively to increase of apical membrane NT.

Interaction of thyroid state and denervation on skeletal myosin heavy chain expression

The goal of this study was to examine the effects of altered thyroid state and denervation (Den) on skeletal myosin heavy chain (MHC) expression in the plantaris and soleus muscles. Rats were subjected to unilateral denervation (Den) and randomly assigned to one of three groups: (1) euthyroid; (2) hyperthyroid; (3) and hypothyroid. Denervation caused severe muscle atrophy and muscle-type specific MHC transformation. Denervation transformed the soleus to a faster muscle, and its effects required the presence of circulating thyroid hormone. In contrast, denervation transformed the plantaris to a slower muscle independently of thyroid state. Furthermore, thyroid hormone effects did not depend upon innervation status in the soleus, while they required the presence of the nerve in the plantaris. Collectively, these findings suggest that both thyroid hormone and intact nerve (a) differentially affect MHC transformations in fast and slow muscle; and (b) are important factors in regulating the optimal expression of both type I and IIB MHC genes. This research suggests that for patients with nerve damage and/or paralysis, both muscle mass and biochemical properties can also be affected by the thyroid state.

Steroid hormone-dependent expression of blocker-sensitive ENaCs in apical membranes of A6 epithelia

Weak channel blocker-induced noise analysis was used to determine the way in which the steroids aldosterone and corticosterone stimulated apical membrane Na+ entry into the cells of tissue-cultured A6 epithelia. Among groups of tissues grown on a variety of substrates, in a variety of growth media, and with cells at passages 73-112, the steroids stimulated both amiloride-sensitive and amiloride-insensitive Na+ transport as measured by short-circuit currents in chambers perfused with either growth medium or a Ringer solution. From baseline rates of blocker-sensitive short-circuit current between 2 and 7 microA/cm2, transport was stimulated about threefold in all groups of experiments. Single channel currents averaged near 0.3 pA (growth medium) and 0.5 pA (Ringer) and were decreased 6-20% from controls by steroid due to the expected decreases of fractional transcellular resistance. Irrespective of baseline transport rates, the steroids in all groups of tissues stimulated transport by increase of the density of blocker-sensitive epithelial Na+ channels (ENaCs). Channel open probability was the same in control and stimulated tissues, averaging approximately 0.3 in all groups of tissues. Accordingly, steroid-mediated increases of open channel density responsible for stimulation of Na+ transport are due to increases of the apical membrane pool of functional channels and not their open probability.

Rehabilitation after total knee arthroplasty: a comparison of 2 rehabilitation techniques

This study was conducted to compare postoperative total knee arthroplasty rehabilitation protocols. The hypothesis of this study was that patients undergoing total knee arthroplasty could achieve range of motion and hospital discharge in the same period using a postoperative rehabilitation protocol that did not use a continuous passive motion machine. This randomized prospective study compared 46 total knee arthroplasties in which a continuous passive motion machine was used with 37 total knees that were rehabilitated with early passive flexion of the knee (named drop and dangle protocol). Postoperative physical therapy regimens were otherwise the same for both groups. Surgical technique was the same for both groups except for closure which was performed in the drop and dangle group with the knee at 90 degrees to 95 degrees flexion. Only patients with osteoarthritis were included in the study, and in both groups of patients received the same prosthetic components. Patients in the drop and dangle group were discharged from the hospital 1 day earlier (p = 0.01) and had a statistically better extension range of 2.8 degrees at 6 months (p = 0.03). Knees in the drop and dangle group had less drainage (p = 0.06). Range of motion and hospital discharge can be achieved in a similar time interval with the drop and dangle technique as with using a continuous passive motion device, and that such a device is not required for postoperative knee rehabilitation.

Presentation format in analogue studies: effects on participants' evaluation

Whether presentation format (video, audio, written transcript, or written transcript with photograph) affects participants' responses to counseling scenarios in an analogue study was examined. After watching a brief counseling session presented in one of four formats, 131 participants completed three instruments measuring counselor credibility and expectations. Results revealed significant differences among the formats on teh COunselor Rating Form (CRF-S; Corrigan & Schmidt, 1983) Trustworthiness and Expertness Scales, with transcripts with pictures rated the highest (higher than videotape and audiotape) and transcripts without pictures rated second highest (higher than video). No significant differences between the presentation formats were revealed on the Expectations about Counseling Questionnaire (EAC; Tinsley, Workman, & Kass, 1980) or 15 Personal Problem Inventory (15PPI; Cash, Begley, McCown, & Weise, 1975). Results suggest that studies using differing formats with the CRF-S are not necessarily comparable and that the four types of analogue approaches may not be interchangeable.

Na+/H+ antiport activity conferred by Bacillus subtilis tetA(L), a 5' truncation product of tetA(L), and related plasmid genes upon Escherichia coli

An Escherichia coli transformant expressing the Bacillus subtilis tetA(L) gene from a weak promoter was challenged by growth on medium with low, increasing tetracycline concentrations. Changes in the substrate preference ratios of the TetA(L)-mediated resistances and antiports were examined in view of recent findings suggesting that TetA(L) catalyzes efflux of Na+ in exchange for protons in addition to having the ability to catalyze metal-tetracycline/H+ antiport. After growth of the transformant on 1 microgram or more of tetracycline per ml for 12 to 15 h, the tetA(L) gene in the plasmid was found to be disrupted by an IS10 element 50 bp from the 5' end of the coding sequence. This disrupted recombinant plasmid, pKB1, conferred greater tetracycline resistance and higher levels of membrane metal-tetracycline/proton antiport than the original plasmid, pJTA1, but conferred lower NA+ resistance and Na+/H+ antiport levels than the original plasmid. The results indicate that the 5' end of the gene is necessary for optimal Na+/H+ antiport but that some such activity as well as robust tetracycline/H+ antiport persists in its absence. Two plasmid genes, tet(K) and qacA, were compared with tetA(L) vis-à-vis their abilities to enhance the Na+/H+ antiporter activity of everted vesicles from E. coli transformants. tet(K), which is more closely related to tetA(L), catalyzed 22Na+ uptake by energized vesicles, whereas the less closely related qacA gene did not.

In vivo and in vitro pressor effects of erythropoietin in rats

Hypertension (HTN) is a common complication of recombinant erythropoietin (EPO) therapy, but the mechanism of the EPO-associated HTN is uncertain. In the present study we examined the effects of EPO and the vehicle alone on rat caudal artery contractile response and basal and thrombin-stimulated platelet cytosolic Ca2+ concentration ([Ca2+]i) in vitro and on blood pressure (BP) and heart rate in vivo. At high concentrations (200 U/ml) EPO caused a small but consistent contraction in the caudal artery rings (P < 0.01) without affecting the response to either angiotensin II (ANG II) or the alpha 1-agonist methoxamine. Incubation with EPO significantly increased basal platelet [Ca2+]i (P < 0.01) and augmented the thrombin-induced rise of [Ca2+]i in Ca(2+)-free medium (P < 0.05). Long-term EPO administration led to a significant elevation of BP within 2 wk regardless of whether the hematocrit was allowed to rise or was kept constant by dietary iron deficiency. In contrast, single intravenous administration of high-dose EPO (400 and 5,000 U/kg), estimated to yield plasma concentrations comparable with those employed in vitro, failed to either alter BP or modify the BP response to ANG II during a 60-min observation period. This was associated with a significant rise in plasma guanosine 3',5'-cyclic monophosphate but no discernible change in plasma atrial natriuretic peptide, suggesting enhanced nitric oxide (NO) release. Thus, at high concentrations, EPO appears to possess a fast-acting pressor effect in vitro but not in vivo. The observed discrepancy may be due to enhanced NO release with EPO administration in vivo. However, HTN does occur with repeated EPO administration in a time-dependent and hematocrit-independent manner. This suggest that expression of the hypertensive effect of EPO in vivo involves a gradual conditioning process.

Adolescent cancer survivors. Psychosocial and familial adaptation

Adolescent cancer survivors were compared with nondiseased control subjects on measures of adaptation, coping, body image, sexual adjustment, psychopathology, and family functioning. Cancer survivors reported no major difficulties in social competence, overall coping, and family communication. Although their school teachers reported no symptoms of psychopathology, the cancer survivors did report body image disturbances and adjustment difficulties. Further, the surviving adolescents were eager to present themselves favorably. Compared with nondiseased control families, families of survivors were characterized as somewhat inflexible. Implications for clinical practice include the careful monitoring of youth who have survived cancer as well as sensitivity to underlying concerns that the survivors and their families may avoid.

Psychosocial and family functioning in children with sickle cell syndrome and their mothers

OBJECTIVE

The purpose of this study was to compare the psychiatric functioning of 61 sickle cell youth and their families with nondiseased sibling controls.

METHOD

Functioning assessed by multiple informants included indices of behavioral, cognitive, and family/interpersonal functioning, self-esteem, life events, coping strategies, temperament, adaptive behavior, and parental psychopathology.

RESULTS

Key findings were that sickle cell patients evidenced more depressive symptoms and associated attributional style, and externalizing behavioral difficulties than did nondiseased siblings. With age, sickle cell youth evidence increasing adaptive behavior deficits and internalizing symptoms. Illness severity was related to symptoms of internalizing behavior and fewer daily living skills. Associations were found between maternal and child coping.

CONCLUSIONS

It is recommended that psychiatric consultations routinely be conducted with these children, particularly at times of family stress and developmental transitions. Psychiatric interventions should focus on ameliorating emotional difficulties via enhancing adaptive coping strategies.

Cognitive status of children treated with central nervous system prophylactic chemotherapy for acute lymphocytic leukemia

Treatment-related cognitive impairments have been reported for survivors of childhood leukemia following prophylactic central nervous system (CNS) treatment with craniospinal radiation. We examined the neurocognitive status of 46 children with acute lymphocytic leukemia (ALL) to assess the impact of a regimen consisting of systemic chemotherapy and prophylactic CNS chemotherapy. By comparing three groups of ALL children (i.e., patients whose diagnosis was recent, patients 1 year postdiagnosis currently receiving CNS prophylactic chemotherapy, and off-therapy patients who had been treated with chemotherapy for 3 years) and their healthy siblings on measures of sequential and simultaneous processing, we were able to examine the effects of CNS prophylactic and systemic chemotherapy at various points during treatment. Results indicate that the children who had received a 3-year course of chemotherapy (off-therapy patients) were more impaired on tasks involving right-hemisphere simultaneous processing than were sibling controls or ALL children whose diagnosis was recent and whose treatment had just begun. Age at diagnosis did not interact with the effects of chemotherapy. These findings support the need for continued evaluation of cognitive functioning in ALL, children receiving CNS prophylactic chemotherapy to identify potential harmful neurocognitive sequelae of treatment.

Psychiatric and family functioning in children with leukemia and their parents

The present study reports data from a cross-sectional investigation of the psychiatric and psychosocial functioning of 55 children diagnosed with acute lymphocytic leukemia and their families at three points in time: diagnosis (newly diagnosed), 1 year postdiagnosis, and 1 year after the completion of chemotherapy (off-therapy). Results reveal minimal psychopathology in these children and their parents based on self- and informant-reports and structured diagnostic interviews. These families appear to be functioning adequately and report more family cohesiveness and marital satisfaction after chemotherapy was completed. Coping strategies commonly used by children and their parents include problem-solving, a positive outlook, and good communication. Implications for psychiatric consultation are presented.

Gender differences in a clinic-referred sample of attention-deficit-disordered children

This study of attention-deficit-disordered children revealed that females were more frequently retained in school and evidenced greater impairment on spatial memory tasks. Moreover, there was a trend for girls to be older at the time of referral. With age, the girls evidenced more severity across a wider array of measures, including cognitive functioning, poorer academic achievement, and more problems with peers.

Ultrastructural correlates of meiotic maturation in mammalian oocytes

Immature mammalian oocytes reside in ovarian follicles with junctionally coupled granulosa cells. When released from a currently undefined meiotic arresting influence, these oocytes resume meiosis to progress from late diplotene (germinal vesicle stage) through the first meiotic division to metaphase II. Oocytes remain at metaphase II until fertilization activates them to complete meiosis. This review summarizes ultrastructural events that occur during meiotic maturation in mammals. Developmental correlates that promise a clearer understanding of regulatory mechanisms operating to control maturation are emphasized. By use of TEM of thin sections, freeze-fracture analysis, and replicated oocyte cortical patches, we demonstrate stage-specific changes in the oocyte nucleus, reorganization of cytoplasmic organelles, correlations between oocyte maturational commitment and the junctional integrity of associated granulosa cells, and definition of the components comprising the oocyte cortical cytoplasm.