Children with social phobia have lower quality friendships than children with other anxiety disorders

BACKGROUND AND OBJECTIVE

Whilst shy, socially anxious or socially withdrawn children in nonclinical community samples report lower friendship quality (FQ) than nonanxious children, no study has examined the FQ of clinically anxious children. The aim of the study was to examine the FQ of children with anxiety disorders; and whether it differs for clinical children with or without a diagnosis of social phobia (SP).

DESIGN

The study design was cross-sectional self-report.

METHODS

Clinical children - 39 anxiety-disordered children with SP and 28 anxiety-disordered children without SP (No-SP) - presented for psychological treatment, and 29 nonclinical children were recruited from the community. Same-sex close friends were invited to participate using an unrestricted nomination procedure. All children were aged between 7 and 13 years. Both target child and friend completed the Friendship Quality Questionnaire and the Spence Children's Anxiety Scale.

RESULTS

Using multilevel modeling within the framework of the Actor-Partner Interdependence Model, SP dyads were found to report lower overall FQ than No-SP dyads. SP dyads did not report lower overall FQ than nonclinical dyads.

CONCLUSION

Children with SP in their diagnostic profile may be unique in their friendship experiences relative to children with other anxiety disorders.

Serotonin transporter [corrected] methylation and response to cognitive behaviour therapy in children with anxiety disorders

Anxiety disorders that are the most commonly occurring psychiatric disorders in childhood, are associated with a range of social and educational impairments and often continue into adulthood. Cognitive behaviour therapy (CBT) is an effective treatment option for the majority of cases, although up to 35-45% of children do not achieve remission. Recent research suggests that some genetic variants may be associated with a more beneficial response to psychological therapy. Epigenetic mechanisms such as DNA methylation work at the interface between genetic and environmental influences. Furthermore, epigenetic alterations at the serotonin transporter (SERT) promoter region have been associated with environmental influences such as stressful life experiences. In this study, we measured DNA methylation upstream of SERT in 116 children with an anxiety disorder, before and after receiving CBT. Change during treatment in percentage DNA methylation was significantly different in treatment responders vs nonresponders. This effect was driven by one CpG site in particular, at which responders increased in methylation, whereas nonresponders showed a decrease in DNA methylation. This is the first study to demonstrate differences in SERT methylation change in association with response to a purely psychological therapy. These findings confirm that biological changes occur alongside changes in symptomatology following a psychological therapy such as CBT.

An investigation into the lower peer liking of anxious than nonanxious children

Peer dislike of anxious behaviour was investigated in 7-12 year olds. Child actors delivered an identical verbal presentation: once in an anxious manner and once confidently. The videos were rated for liking and seven potential mediators by three groups of children: 32 anxiety-disordered peers with social phobia; 16 anxiety-disordered peers without social phobia; and 48 nonclinical peers. A mediation model with moderation effects was tested within a within-subjects framework. "Anxious" actors were liked significantly less than "confident" actors. This effect differed by group rater, in that relative dislike of the anxious actor was significantly greater for the nonclinical than socially phobic raters. Physical attractiveness and friend acceptance mediated the effect for all group raters. Other identified mediators differed depending upon the group rater. The findings direct future efforts to help anxiety-disordered children circumvent an increased risk of negative peer relations, and testify to consideration of the rater in sociometric studies.

Notizen: Cloud Attractors and Time-Inverted Julia Boundaries

Cloud attractors are predicted to exist in simple invertible systems. The explicit noodle map (a three-dimensional diffeomorphism) and several 4-variable ODEs (describing chemical reactors) provide candidates. A “widely spaced” Lyapunov spectrum (+ , - e, - ) may in general warrant a numerical search.

Spatial Learning Deficits Induced by Muscimol and CL218,872: Lack of Effect of Prenatal Malnutrition

The sensitivity of prenatal protein malnourished rats to the amnestic properties of the direct GABAA receptor agonist muscimol and the selective benzodiazepine (BZ) receptor agonist, CL218,872, was studied in the male offspring of rats provided with a protein deficient diet (6% casein) for 5 weeks prior to mating and throughout pregnancy. At postnatal day 90, rats were tested during acquisition of the submerged platform version of the Morris water maze task using four systemic doses of muscimol (0.1, 0.3, 1.0 and 1.8 mg/kg i.p.) or three systemic doses of CL218,872 (1.0, 3.2, and 5.6 mg/kg i.p.). In a dose dependent manner both drugs impaired acquisition of the task and impaired accuracy of the search pattern on the probe trial (platform removed). However, neither drug dissociated the performance of the two nutritional groups. These data are important in light of previous findings of differential behavioral effects of the non-specific BZ agonist, chlordiazepoxide (CDP), on spatial learning and on drug discrimination in prenatally malnourished rats and in the context of previous findings of reduced sensitivity to the anxiolytic effects of non-specific BZ receptor agonists across a wide variety of models of malnutrition. The present findings also support the concept that prenatal malnutrition does not affect the global functioning of the GABAA receptor, but fundamentally alters the way in which a subset of GABAA receptors (i.e. those containing the alpha2, alpha3 and/or the alpha5 but not the alpha1 subunit) is modulated by BZs.

An automated algorithm for the generation of dynamically reconstructed trajectories

The lack of long enough data sets is a major problem in the study of many real world systems. As it has been recently shown [C. Komalapriya, M. Thiel, M. C. Romano, N. Marwan, U. Schwarz, and J. Kurths, Phys. Rev. E 78, 066217 (2008)], this problem can be overcome in the case of ergodic systems if an ensemble of short trajectories is available, from which dynamically reconstructed trajectories can be generated. However, this method has some disadvantages which hinder its applicability, such as the need for estimation of optimal parameters. Here, we propose a substantially improved algorithm that overcomes the problems encountered by the former one, allowing its automatic application. Furthermore, we show that the new algorithm not only reproduces the short term but also the long term dynamics of the system under study, in contrast to the former algorithm. To exemplify the potential of the new algorithm, we apply it to experimental data from electrochemical oscillators and also to analyze the well-known problem of transient chaotic trajectories.

Sudden Onset of Pitting Corrosion on Stainless Steel as a Critical Phenomenon

Stainless steels undergo a sharp rise in pitting corrosion rate as the potential, solution concentration, or temperature is changed only slightly. We report experiments using real-time microscopic in situ visualizations that resolve the nucleation and evolution of individual pits during the transition. They suggest that the sudden onset of corrosion is explained by an explosive autocatalytic growth in the number of metastable pits and that stabilization of individual pits takes place only later. This finding agrees with a theoretical approach treating the onset of pitting corrosion as a cooperative critical phenomenon resulting from interactions among metastable pits, and it extends perspectives on the control and prevention of corrosion onset.

Adaptive control of unknown unstable steady states of dynamical systems

A simple adaptive controller based on a low-pass filter to stabilize unstable steady states of dynamical systems is considered. The controller is reference-free; it does not require knowledge of the location of the fixed point in the phase space. A topological limitation similar to that of the delayed feedback controller is discussed. We show that the saddle-type steady states cannot be stabilized by using the conventional low-pass filter. The limitation can be overcome by using an unstable low-pass filter. The use of the controller is demonstrated for several physical models, including the pendulum driven by a constant torque, the Lorenz system, and an electrochemical oscillator. Linear and nonlinear analyses of the models are performed and the problem of the basins of attraction of the stabilized steady states is discussed. The robustness of the controller is demonstrated in experiments and numerical simulations with an electrochemical oscillator, the dissolution of nickel in sulfuric acid; a comparison of the effect of using direct and indirect variables in the control is made. With the use of the controller, all unstable phase-space objects are successfully reconstructed experimentally.

Cooperative action of coherent groups in broadly heterogeneous populations of interacting chemical oscillators

We present laboratory experiments on the effects of global coupling in a population of electrochemical oscillators with a multimodal frequency distribution. The experiments show that complex collective signals are generated by this system through spontaneous emergence and joint operation of coherently acting groups representing hierarchically organized resonant clusters. Numerical simulations support these experimental findings. Our results suggest that some forms of internal self-organization, characteristic for complex multiagent systems, are already possible in simple chemical systems.

Stabilizing and tracking unknown steady States of dynamical systems

An adaptive dynamic state feedback controller for stabilizing and tracking unknown steady states of dynamical systems is proposed. We prove that the steady state can never be stabilized if the system and controller in sum have an odd number of real positive eigenvalues. For two-dimensional systems, this topological limitation states that only an unstable focus or node can be stabilized with a stable controller, and stabilization of a saddle requires the presence of an unstable degree of freedom in a feedback loop. The use of the controller to stabilize and track saddle points (as well as unstable foci) is demonstrated both numerically and experimentally with an electrochemical Ni dissolution system.

Suppressing spatiotemporal disorder via local perturbations in an electrochemical cell

We report experimental results depicting suppression of complex spatiotemporal dynamics under the influence of local periodic stimulations. In an experimental electrochemical system, applying a continuous forcing signal to one of the sites in an array of eight coupled oscillators, the naturally complex behavior of the remaining seven electrodes can be converted to periodic responses. The oscillations remain periodic as long as the forcing is active and revert back to exhibiting chaotic dynamics after the control is switched off. These results can also be interpreted as experimental realization of "phase-synchronization" induced via local driving in an extended system. A possible relevance to the experimentally observed calcium wave patterns is pointed out.

Parent-child interactions and anxiety disorders: an observational study

Past research has indicated a potential link between anxiety and parenting styles that are characterised by control and rejection. However, few studies have utilised observational methods to support these findings. In the current study, mother-child interactions were observed while the child completed two difficult cognitive tasks. The sample consisted of clinically anxious children (n=43), oppositional defiant children (n=20) and non-clinical children (n=32). After adjusting for the age and sex of the child, mothers of anxious children and mothers of oppositional children displayed greater and more intrusive involvement than mothers of non-clinical children. Mothers of anxious children were also more negative during the interactions than mothers of non-clinical children. The differences between anxious and non-clinical interactions were equivalent across three separate age groups. The results support the relationship between an overinvolved parenting style and anxiety but question the specificity of this relationship.

Phase synchronization and suppression of chaos through intermittency in forcing of an electrochemical oscillator

External periodic forcing was applied to a chaotic chemical oscillator in experiments on the electrodissolution of Ni in sulfuric acid solution. The amplitude and the frequency (Omega) of the forcing signal were varied in a region around Omega=omega(0), where omega(0) is the frequency of the unforced signal. Phase synchronization occurred with increase in the amplitude of the forcing. For Omega/omega(0) near 1 the signal remained chaotic after the transition to the phase-locked state; for Omega/omega(0) somewhat farther from 1 the transition was to a periodic state via intermittency. The experimental results are supported by numerical simulations using a general model for electrochemical oscillations.

Controlling spatiotemporal chemical chaos using delayed feedback

Control of chemical chaos in a spatially extended system mimicking CO oxidation on a Pt(110) single-crystal surface is achieved using delayed feedback techniques. For appropriate parameter values the uncontrolled model system exhibits both amplitude and phase turbulence. Superimposing a delayed feedback on the natural dynamics, suppression of spatiotemporal complexity is attained via stabilization of ordered states consisting of stable patterns.

Clustering of arrays of chaotic chemical oscillators by feedback and forcing

Feedback and external forcing are applied to an array of chaotic electrochemical oscillators through variations in the applied potential. We see transitions from intermittent clusters to stable chaotic clusters to stable periodic clusters to synchronized states as the feedback gain and forcing amplitude, respectively, are varied. With forcing up to four clusters are observed in stable states. The transition to synchronization with feedback occurs by the increase in the size of one cluster at the expense of the others.

Spatiotemporal patterns and symmetry breaking on a ring electrode

A series of experiments on a ring electrode with changes in a parameter, the applied potential, are described. Spatiotemporal patterns are investigated in a region of parameter space in which relaxation oscillations occur. The simplest state is a period 2Pi oscillation that has full O(2) symmetry so that at each instant the pattern is unchanged by rotations or reflections of the ring. With change in parameter a spatiotemporal period doubling occurs to period 4Pi. This is followed by a symmetry breaking to another state with period 4Pi and subsequently by a second period doubling to period 8Pi. Proper orthogonal decomposition is used as an aid in elucidating the nature of the transitions.

Issues in the diagnosis and assessment of anxiety disorders in children and adolescents

Accurate diagnosis and assessment of anxiety disorders in children and adolescents is important for both treatment and research. In this paper, we review research related to the discriminant validity of the childhood anxiety disorders, and outline methods of assessment for children, including diagnostic interviews, self-report instruments, and behavioural, cognitive, and psychophysiological measures. Particular attention is given to psychometric and developmental issues, and their influence on assessment. The evidence provides support for the validity of the anxiety disorders as a whole, but only partial support for differentiation between specific anxiety disorders in children. Similarly, assessment methods used with anxious children provide reasonably accurate information on anxious symptoms, however are limited by poor discriminant validity and lack of sensitivity to developmental levels.

Experiments on arrays of globally coupled chaotic electrochemical oscillators: Synchronization and clustering

Experiments on chaotically oscillating arrays of 64 nickel electrodes in sulfuric acid were carried out. External resistors in parallel and series are added to vary the extent of global coupling among the oscillators without changing the other properties of the system. The array is heterogeneous due to small variations in the properties of the electrodes and there is also a small amount of noise. The addition of global coupling transforms a system of independent elements to a state of complete synchronization. At intermediate coupling strengths stable clusters, or condensates of elements, form. All the elements in a cluster follow the same chaotic trajectory but each cluster has its own dynamics; the system is thus temporally chaotic but spatially ordered. Many cluster configurations occur under the same conditions and transitions among them can be produced. For values of the coupling parameter on either side of the stable cluster region a non-stationary behavior occurs in which clustered and synchronized states alternately form and break up. Some statistical properties of the cluster states are determined. (c) 2000 American Institute of Physics.

The origins of social phobia

A greater understanding of the origins of social phobia is much needed. The research to date is limited by the relatively small number of studies that sample clinical populations of individuals with social phobia. There is, however, research derived from related areas such as shyness, social anxiety, self-consciousness, peer neglect, and social withdrawal that contributes to a richer understanding of the etiology of social fears. Combining these areas of research, this review addresses four main factors that may be important to the origins of social phobia: (a) genetic factors; (b) family factors; (c) other environmental factors; and (d) developmental factors.

Impact of mitochondrial Ca2+ cycling on pattern formation and stability

Energization of mitochondria significantly alters the pattern of Ca2+ wave activity mediated by activation of the inositol (1,4,5) trisphosphate (IP3) receptor (IP3R) in Xenopus oocytes. The number of pulsatile foci is reduced and spiral Ca2+ waves are no longer observed. Rather, target patterns of Ca2+ release predominate, and when fragmented, fail to form spirals. Ca2+ wave velocity, amplitude, decay time, and periodicity are also increased. We have simulated these experimental findings by supplementing an existing mathematical model with a differential equation for mitochondrial Ca2+ uptake and release. Our calculations show that mitochondrial Ca2+ efflux plays a critical role in pattern formation by prolonging the recovery time of IP3Rs from a refractory state. We also show that under conditions of high energization of mitochondria, the Ca2+ dynamics can become bistable with a second stable stationary state of high resting Ca2+ concentration.

Microglial cell responses to fetal ventral mesencephalic tissue grafting and to active and adoptive immunizations

Microglia express cytokines, major histocompatibility (MHC) loci, and several other immunologically important constituents. The aim of this study was to detect immunological responses of microglial cells following allogeneic dopaminergic transplantation using active and adoptive immunizations. Adult inbred Fisher 344 (F344 RT1) rats were unilaterally dopamine (DA) depleted in striatum by injection of 6-hydroxydopamine. The degree of degeneration was assessed by recording the rotational response to apomorphine. Fetal ventral mesencephalic tissue containing DA neuroblasts from Wistar-Furth (WF, RT1u) rat donors (9-12 mm CRL) were later implanted in striatum on the lesioned side. Lymph nodes and spleen cells were collected aseptically, resuspended, and diluted for isovolumetric injections. Animals selected for active immunization were injected intraperitoneally with varying amounts of WF lymphocytes. Animals selected for adoptive immunization (transferred immunity) were intraperitoneally injected with 10(8) F344 lymphocytes prepared from animals actively immunized 3 weeks previously. Monoclonal antibodies against CD4 (OX38), CD8 (OX8), CD11b (OX42), MHC class I (OX18), monomorphic MHC class II (OX-6), and ED1 and polyclonal antibodies against tyrosine hydroxylase (TH) were used for immunohistochemistry. We found that the degree of ED1-positive cell proliferation was well correlated to the immunization patterns. Groups that were actively immunized with or without prior adoptive immunization had a larger amount of reactive microglial proliferation. ED1 immunohistochemistry revealed patterns of immunolabeling of engrafted areas: 8-12 weeks after grafting in nonimmunized and adoptively immunized groups reactive microglial proliferation occurred only at the graft periphery. Active and adoptive + active immunization led to ED1-IR within the grafts themselves. At early stages nonimmunized groups had an ED1 pattern which was partially inside the grafts. At early time points nonimmunized groups contained ameboid microglial cells within the grafts which disappeared at later stages and were absent in the immunized groups. ED1-positive ameboid microglial cells within the grafts may be of graft origin and constitute a part of a continued normal development of the fetal tissue.

Allogeneic grafts of fetal dopamine neurons: immunological reactions following active and adoptive immunizations

To define the importance of adoptive sensitization and duration of graft residence on transplant alloimmunization, behavioral and histochemical parameters were examined in unilaterally 6-OHDA-lesioned F344 rat hosts which received fetal ventral mesencephalic (VM) grafts from Wistar-Furth (WF) donors. In all animals which showed increased rotations after alloimmunization, increased numbers of T cell receptor (TcR) positive, CD8+ lymphocytes were detected in the grafts. In addition, an increased density of class I MHC antigens was seen in the graft and in the adjacent host brain. Lesser numbers of CD4+, CD11b+, and MHCII+ positive elements were also seen. Perivascular cuffing was often found in actively immunized animals. An increase in TcR+ and MHC class I+ elements was also seen in animals only adoptively immunized. The tyrosine hydroxylase positive graft area was also markedly reduced in actively immunized animals and the extent of reduction correlated with the number of cells used for immunization. These studies indicate that established allografts can evade rejection as long as host lymphocytes are not activated against graft alloantigens. In addition, increasing graft residence time in the host and adoptive immunization render the graft more susceptible to subsequent rejection.

Chronic treatment with levodopa and/or selegiline does not affect behavioral recovery induced by fetal ventral mesencephalic grafts in unilaterally 6-hydroxydopamine-lesioned rats

It has been suggested that levodopa (L-dopa), a dopamine precursor used to treat Parkinson's disease, may be toxic to grafted fetal neuroblasts; if so, the use of the monoamine oxidase B inhibitor selegiline might prevent such toxicity. We randomly assigned 30 unilaterally 6-hydroxydopamine-lesioned male Sprague-Dawley rats, whose lesions were verified with low-dose apomorphine-induced rotations, to one of five treatment groups: (i) L-dopa methyl ester (125 mg/kg/day) with benserazide (a peripheral decarboxylase inhibitor; 25 mg/kg/day), (ii) L-dopa methyl ester with benserazide and selegiline (L-deprenyl; 0.5 mg/kg/day), (iii) selegiline only, (iv) and (v) vehicle (ascorbate in normal saline) only. After 2 weeks of twice-daily ip injections, the rats received fetal ventral mesencephalic grafts into the lesioned striatum; one vehicle group received sham grafts. Drug therapy was continued for 2 1/2 months post grafting. At 1 month after grafting, and every 2 weeks thereafter, the rats were tested using low-dose apomorphine-induced rotation. A 70% decrease in rotations among all grafted groups, relative to the shams, was found. No statistical differences among groups receiving various drug therapies were seen in behavior or in counts or dimensions of tyrosine hydroxylase-positive cells. We therefore conclude that, in the unilaterally lesioned rat model of Parkinson's disease, there is no adverse effect of L-dopa nor any significant effect of selegiline, either alone or coadministered with L-dopa, on behavioral recovery induced by fetal ventral mesencephalic grafts.

Conditioned apomorphine-induced turning in 6-OHDA-lesioned rats

Apomorphine-induced turning has been used to evaluate the extent of unilateral nigrostriatal denervation after 6-hydroxydopamine (6-OHDA) lesions and subsequent functional striatal reinnervation by catecholaminergic grafts. It has been noted that the pregraft rotational pattern is usually double peaked and that fetal ventral mesencephalic grafts or dopaminergic drugs will alter the second peak but leave the first relatively unchanged. We hypothesized that the first peak may be the result of factors extrinsic to the nigrostriatal dopamine system, specifically a conditioned turning response, and would, therefore, be unperturbed by the above treatments which increase dopaminergic (DA) inputs. This was investigated by injecting 6-OHDA, unilaterally, into the nigrostriatal pathway of several groups of young Fisher 344 rats. One experimental group was repeatedly tested with 0.05 mg/kg apomorphine and the rotations quantified. A second group received similar injections of apomorphine but were prevented from rotating. Vehicle control animals were also studied for both of the above experimental groups. Subsequent to the above treatment, all animals were tested unrestrained repeatedly on apomorphine. Our results support the conditioned response hypothesis in that the first peak is not present with the initial unrestrained apomorphine behavioral trial but is present upon the second and subsequent unrestrained trials. Moreover, the restrained but apomorphine-injected rats, as well as the control animals, manifest no first peak upon their first freely moving apomorphine test; the second and subsequent unrestrained apomorphine trials, in these groups, do manifest a first peak.(ABSTRACT TRUNCATED AT 250 WORDS)

Allogeneic grafts of fetal dopamine neurons: behavioral indices of immunological interactions

Fetal central nervous system transplants to the adult brain have been utilized to understand brain connectivity and as replacement therapy in Parkinson's disease (PD). Here we use fetal brain allografting in the rat unilaterally depleted of dopamine, a unilateral model of PD, and apomorphine-induced rotations as an index of graft functional status while peripherally manipulating the host's alloimmune status. This system allows the investigator to examine, dynamically, host-allograft interactions in the brain under differing states of alloimmunoreactivity without the need to biopsy or sacrifice the animal. In addition to this novel application, we established that brain allografts are differentially susceptible to immunologic attack depending upon the graft's duration of residence in the host brain. Increasing residence time increases graft 'rejectability' to peripheral allosensitization. Passive immunization also sensitizes the host to subsequent graft rejection. Lastly, simple host alloimmunocompetence is necessary but not sufficient to cause fetal graft 'rejection', defined as a return of apomorphine-induced rotations.

Target and neurotransmitter specificity of fetal central nervous system transplants: importance for functional reinnervation

The ability of grafted fetal ventral mesencephalic dopaminergic (DAergic) neuroblasts to reinnervate the unilaterally DA denervated rat striatum and improve motoric asymmetry has been well documented in several laboratories. The importance of host target specificity, and catecholamine (CA) neurotransmitter species, in the ability of grafts to ameliorate rotational responses to apomorphine and to affect electrophysiological characteristics of striatal neurons has not been systematically studied. We unilaterally lesioned Sprague-Dawley rats with 6-hydroxydopamine (6-OHDA) and verified the lesions using apomorphine (0.05 mg/kg, s.c.)-induced rotational behavior. Some of the animals subsequently received, intrastriatally, either DA neuroblasts from ventral mesencephalon that normally innervate the striatum, or from arcuate nucleus that do not. Additionally, two other groups were included that received either a CAergic graft from the noradrenergic nucleus locus coeruleus or a graft of cerebral cortex, which normally projects to the striatum but does not contain CAergic neurons. Only the fetal ventral mesencephalic grafts were able to reduce apomorphine-induced rotations and normalize striatal cell firing rates; striatal cell firing rates with ventral mesencephalic grafts were 1.43 Hz +/- 0.22, with arcuate nucleus grafts were 6.03 +/- 0.73, with locus coeruleus grafts were 4.71 +/- 0.74, and with cerebral cortex grafts were 4.36 +/- 0.45. Moreover, only the ventral mesencephalic grafts produced a dense tyrosine hydroxylase (TH)-immunoreactive nerve terminal network in the striatum; in contrast, the arcuate nucleus grafts did not reinnervate the striatum. In locus coeruleus grafted striata, few very long TH-positive axons were seen. We thus conclude that target specificity and neurotransmitter type are critically important in the ability of a graft to functionally reinnervate the 6-OHDA denervated striatum.

Clinical estimate of birth-weight in labour: factors influencing its accuracy

Clinical assessments of birth-weight were made among 88 parturients at term, to determine what maternal and neonatal factors influence the accuracy of predicting neonatal weight. An estimate within +/- 10% of actual weight was considered accurate, while a prediction off by more than 10% was classified as inaccurate. Seventy-one per cent (63 of 88) of the estimates were considered accurate and 28% (25 of 88) inaccurate. Among these 2 groups of patients, univariate analysis did not identify maternal age, gravidity, parity, gestational age, maternal height, prepregnancy weight and maternal body mass index, maternal weight and maternal body mass index at the time of delivery, change in body mass index during pregnancy, intrapartum amniotic fluid index, newborn's weight, length, and ponderal index as being significant correlates of an accurate clinical estimate of the birth-weight. Over 2 years, as the provider gained experience in predicting the neonatal weight, the accuracy of the clinical estimate of birth-weight did not improve.

A 16-channel automated rotometer system for reliable measurement of turning behavior in 6-hydroxydopamine lesioned and transplanted rats

Unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway in rats result in a massive dopamine (DA) denervation of the ipsilateral striatum. Such animals have proven extremely useful as a model for the study of Parkinson's disease, an idiopathic neurodegenerative disorder of humans. Extensive unilateral DA disruption leaves the rat relatively normal in motor behavior; however, the extent of the lesion can be documented by drug-induced rotational behavior. When given an injection of a dopamine agonist, such as apomorphine or D-amphetamine, a lesioned animal will manifest rotational behavior; the number of turns correlates with the degree of unilateral denervation. In order to identify, for various studies, large numbers of animals with specific levels of denervation, the necessity of an automated and reliable rotational counting system (rotometer) becomes obvious. We have developed such a device that allows up to 16 rats to be tested concurrently with one inexpensive computer. This system is more reliable than, and certainly preferable to, more tedious methods such as videotaping and subsequent manual analysis or various other mechanical systems. Plexiglass, formed into large bowls, serve as the rotometer chambers. We have designed a simple, inexpensive, and accurate counting head that can be manufactured from readily available parts and that is very sturdy and reliable. This, together with a thoracic harness, completes the rotometer assembly. The rotational data, from up to 16 separate channels, is collected by a single-chip microprocessor and sent on a serial line to an IBM-type or MacIntosh host computer. There, it is graphically displayed on line and subsequently saved to disk with a novel acquisition program.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of apomorphine- and amphetamine-induced turning with nigrostriatal dopamine content in unilateral 6-hydroxydopamine lesioned rats

In the unilateral 6-hydroxydopamine (6-OHDA)-lesioned rat model of Parkinson's disease, controversy exists concerning the use of apomorphine- or D-amphetamine-induced rotations as reliable indicators of nigrostriatal dopamine depletion. Our objective was to evaluate which, if either, drug-induced behavior is more predictive of the extent of nigrostriatal dopamine depletion. Fischer 344 and Sprague-Dawley rats were unilaterally injected with 9 micrograms/4 microliters/4 min 6-hydroxydopamine into the medial forebrain bundle. The animals were behaviorally tested with apomorphine (0.05 mg/kg, s.c.) and D-amphetamine (5.0 mg/kg, s.c.). Following testing, the brains were removed and the right and left striata, substantia nigra and ventral tegmental area were dissected free and quickly frozen at -70 degrees C for analysis of catecholamine content by high performance liquid chromatography coupled with electrochemical detection. Our results indicate that an animal which has greater than a 90% depletion of dopamine in the striatum might not rotate substantially on apomorphine, without a concomitant depletion of > 50% of the DA content in the corresponding substantia nigra. No correlations were seen involving depletions of the ventral tegmental area and the extent of the lesions to the striatum. Submaximally lesioned (75-90% depleted) rats were found to rotate on D-amphetamine but not on apomorphine. In addition, control rats that did not receive lesions were often seen to rotate extensively on D-amphetamine. We therefore conclude that maximal lesions of the striatum and substantia nigra are required to generate rotations demonstrable with low dose apomorphine but not with D-amphetamine.(ABSTRACT TRUNCATED AT 250 WORDS)