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PubMed1999

Stuttering children and the probability of remission--the role of cerebral dominance and speech production.

OBJECTIVE: The identification of critical characteristics which might predict whether childhood stuttering will become chronic. Part of the study investigates the relationship between hearing and central processing of acoustic stimuli, cerebral dominance and the clinical course of the stuttering. METHODS: A prospective study of 79 stuttering children aged 3-9 years. The subjects were examined with regard to their cerebral dominance in various tests of laterality, their peripheral hearing and their ability to discriminate sound using the dichotic discrimination test according to Uttenweiler (V. Uttenweiler, Dichotischer Diskriminationstest für Kinder, Sprache Stimme Gehör 4 (1980) 107-111). Results were correlated with the probability of remission of stuttering. Comparisons were made with a control group of 18 children of kindergarten age with normal speech. The period of investigation was 18 months. RESULTS: Seventy-two children underwent follow-up examinations. Of these, 36 achieved fluency of speech. The results of the dichotic discrimination test showed no relation to the rate of remission. When the relationship between handedness and stuttering was investigated, it was found that left-handed children had a significantly poorer chance of attaining speech fluency. CONCLUSIONS: The Uttenweiler test allowed no prognostic evaluation of the future course of stuttering in the age group studied, though auditory dominance was not completely developed in a majority of the 3-6 year-old children. Handedness, however, appears to be related to the probability that stuttering will become chronic.

Case-Control Studies↗
PubMed2001

Circular polarisation in star-forming regions: possible implications for homochirality.

Our discovery of high degrees of circular polarisation in some star-forming regions provides an attractive mechanism for the origin of homochirality. The largest degrees of circular polarisation, so far observed at near-infrared wavelengths, are thought to arise from the scattering of stellar radiation from aligned dust grains and are calculated to extend down to UV wavelengths. The extent of the region where circularly polarised light (CPL) of a single handedness originates is very large, and it is likely that the whole of a planetary system would see a single handedness of CPL also. We present the observational data, models of the scattering that leads to the production of CPL, and a model for the origin of homochirality. We also discuss briefly future laboratory and space-based experiments.

Astronomical Phenomena↗
PubMed1999

Hypermobility and peripartum pelvic pain syndrome in pregnant South African women.

OBJECTIVE: To determine the incidence and correlation of joint hypermobility (HM) and peripartum pelvic pain (PPPP) in an homogeneous pregnant South African population. STUDY DESIGN: A cross-sectional study among Cape Coloured pregnant women. Joint mobility was measured by Beighton score; PPPP with a specially developed PPPP score. RESULTS: Using the Beighton scores with a cut-off point of HM > or = 5/9, only 4.9% of the 509 pregnant women were hypermobile. Hyperextension of the elbow was the largest contributor to HM (35.4%). No correlation of HM with the incidence of PPPP was established. Only 20 very mild cases of PPPP were recorded. Back pain increased significantly during pregnancy to a mean of 38%. Right handedness occurred in 95.9%. No significant relation was found between HM and the non-dominant side. CONCLUSION: Hypermobility in pregnant Cape Coloured women was surprisingly low (4.9%) with a decrease with age, but no increase during pregnancy. Peripartum pelvic pain is virtually absent and has no correlation with joint laxity. Back pain increased during pregnancy to a mean of 38%. Right handedness was high (96%) in comparison with the world-wide figure of 85%. No correlation was found between the dominant body side and hypermobility.

Adolescent↗
PubMed2000

Factors associated with early menopause.

OBJECTIVE: An understanding of why certain factors contribute to a more rapid decline in ovarian function may, for some women, help prevent premature loss of fecundity and the subsequent impact of health problems secondary to long-term estrogen deficiency such as osteoporosis, cardiovascular disease, and possibly Alzheimer's disease. METHODS: A summary of the evidence regarding factors that have been proposed to contribute to an early onset of natural menopause is presented. These factors include cigarette smoking, race, education, parity, menstrual cycle length, the use of oral contraceptives, age at menarche, major depression, anthropometry, and handedness. RESULTS: Cigarette smoking has been found to hasten the onset of menopause by as much as one year. Lifetime number of ovulatory cycles (indicative of oocyte depletion) is also predictive of the age at natural menopause (ANP). This is consistent with the many studies that have reported early ANP among women with shorter menstrual cycles, and a later ANP among multigravid women or those who used oral contraceptives. The relationship between depressive disorder and ovarian failure is complex, involving consideration of the pharmacological effects of treatment, and is currently unclear. The findings regarding an effect of body mass index on ANP are also mixed. At this time, there is little persuasive evidence that handedness or demographic characteristics (independent of their relationship with behavioral factors like smoking) influence the ANP to any substantial degree. CONCLUSIONS: Some factors that could potentially influence ANP have been identified, but these and other avenues of investigation warrant further study.

Female↗
PubMed1991

Supine and prone head orientation preference in term infants.

Head orientation preference in the supine and prone positions was studied in 62 healthy term born infants at three different times within 24 hours after delivery. Head orientation preference was related to: the foetal position, the initial head position when the newborn was lying prone on the abdomen of the mother, the handedness of the parents and the state of the infant (according to Prechtl). Although for the whole group a head orientation preference for the right side was observed, an individual significant head orientation preference was observed in less than 50% of the infants studied. Neither the occurrence nor the direction of head orientation per individual was constant during the observation period. No relationship was found between an infant's head orientation and foetal position, initial head position, handedness of the parents, or the state of the infant. Our data suggest that persistent head orientation preference to one side in a healthy term born infant within 24 hours after delivery is a sign of abnormality. Head orientation to the right should not be considered as a sign of normality.

Choice Behavior↗
PubMedDate not supplied

Specification of left-right asymmetry in mammals: embryo culture studies of stage of determination and relationships with morphogenesis and growth.

The internal mammalian body plan is laterally asymmetric with a consistent handedness such that some organs are placed on one side (stomach on the left, for example) and paired organs are not symmetric (for example, there are more lung lobes on the right). Some chemical teratogens can affect the development of asymmetry, and some can cause asymmetric defects in overtly symmetric structures, but the mechanisms are unknown. We have used chemical treatment of rat embryos in culture to examine the stage at which the left-right axis is determined and show that all effective treatments can affect left-right axis development up to the early headfold stage, but not from late headfold onwards. This suggests that the left-right axis is determined by the late headfold stage, even though the embryo is overtly symmetric at this stage. It appears to be much easier to induce an abnormal left-right axis from late allantoic bud and early headfold stages than the early allantoic bud stage, but we have not established the earliest stage at which a response can be induced. Complete situs inversus was the most common chemically induced abnormality, although heart looping and body turning could be inverted separately, suggesting that the two phenomena are linked but not wholly interdependent. The treatments appeared to cause a loss of handedness, rather than inducing inversion, since the incidence of an abnormal left-right axis never exceeded 50%. All treatments except methoxamine, an alpha1 adrenergic agonist, induced an abnormal left-right axis in association with other morphologic defects and growth retardation. However, there was no relationship between the severity or incidence of dysmorphology, nor growth retardation, and left-right abnormality, suggesting that although the process that specifies lateral asymmetry is labile, it is independent of general growth and morphogenesis.

Abnormalities, Drug-Induced↗
PubMed2003

Sex differences in the corpus callosum of patients with schizophrenia.

The corpus callosum (CC) has been of interest in schizophrenia research because of its possible role in reduced lateralization and because of its sexually dimorphic characteristics. The literature has been replete with structural brain studies that have yielded equivocal results because of failure to address sex differences, handedness, and overall reductions in total brain volume (TBV) associated with schizophrenia. We performed midsagittal corpus callosum area MRI measurements on 71 chronically ill patients with schizophrenia (52 males, 19 females) and 67 controls (49 males, 18 females) using a semiautomated analytic technique subdividing the corpus callosum into five segments. Consistent with a meta-analysis [J. Neurol., Neurosurg. Psychiatry 58 (1995) 457], reductions in total CC area (after controlling for TBV and age) were found in schizophrenia patients relative to controls. However, our effect size, though not statistically significant, was -0.33 compared to -0.18 for the meta-analysis, indicating greater reductions in total CC area in our group of patients. Statistical significance was achieved only in male patients versus male controls (effect size=-0.50). The effect size remained the same when only right-handers were included in the analysis; thus, handedness did not account for this result. CC size was not related to psychiatric symptoms nor cognitive functioning in this group of patients.

Adult↗
PubMed1998

Hemispheric specialization in schizophrenics with perceptual aberration.

Higher rates of left-handedness and atypical lateralization in schizophrenics paired with findings of morphological abnormalities in cerebral asymmetry suggest that the normal patterns of hemisphere specialization for processing verbal and spatial information may be anomalous in schizophrenics. The small number of studies that have addressed this question have produced inconsistent findings and varied with subtype diagnosis, gender, type of task employed, task difficulty, and control of handedness. Conflicting research findings also may be due to confounding from the heterogeneity of the schizophrenic construct and variability in clinical symptoms across patients. The present study was designed to control for factors that may have confounded earlier studies. Because the study used perceptual measures, the relationship between symptoms of perceptual aberration and hemisphere advantages was examined using Chapman et al.'s (1978) Perceptual Aberration Scale (PAS). Fifteen male schizophrenic patients and 14 male controls were administered tachistoscopic letter and facial recognition go/no-go reaction time tasks. Left hemisphere advantages were found for both controls and schizophrenics on the letter task. Right hemisphere advantages were found for controls on the facial task but not schizophrenics. Instead, a strong negative correlation was found between schizophrenics' PAS scores and hemisphere advantages (r = -0.685, p < 0.007). Further analysis identified a subgroup of schizophrenics with perceptual aberration who exhibited reversed left hemisphere advantages that increased as the PAS scores increased. Additional research is needed to determine whether this subgroup of schizophrenics constitutes a meaningful subtype with a distinct disease process that disrupts the development of normal cerebral lateralization. The findings provide further evidence for the importance of examining relationships between schizophrenics' performance on cognitive measures and their symptom patterns.

Adult↗
PubMed2002

Sinistrality in subtypes of schizophrenia.

UNLABELLED: Sinistrality, characterized by an excess of non-right-handedness, has been reported in schizophrenic patients, but the findings are controversial. AIM: As sinistrality could be linked to a failure of hemisphere specialization in schizophrenia that would translate into language disorders, sinistrality was found out in disorganized and positive schizophrenic patients characterized by language disorders. METHODS: Seventy-three schizophrenic patients (DSM IV) and 81 controls were evaluated with the Edinburgh Handedness Inventory (EHI). Patients were evaluated and classified into five subtypes (deficit, positive, disorganized, mixed and residual) with the Positive and Negative Syndrome Scale and the Schedule for the Deficit Syndrome. RESULTS: Disorganized patients had a significantly more severe sinistrality in comparison to the deficit, residual and mixed subtypes and controls. A negative correlation was found between the disorganization and the EHI scores (r = - 0.34; P < 0.01). A significantly more severe sinistrality was also observed in the positive subtype in comparison to controls, but there was no correlation between hallucinatory and EHI scores (r = 0.06). CONCLUSION: The findings provided further evidence that the defects in the normal process of lateralization observed in schizophrenia affects primarily disorganized patients.

Adult↗
PubMed2002

EFSUMB: safety tutorial: epidemiology of diagnostic ultrasound exposure during pregnancy-European committee for medical ultrasound safety (ECMUS).

The present paper summarizes some of the epidemiological studies of in utero ultrasound exposure and subsequent childhood development. Emphasis is placed on birth weight, childhood malignancies, neurological development, handedness and speech development. The epidemiological evidence does not indicate any association between diagnostic ultrasound exposure during pregnancy and reduced birth weight, childhood malignancies or neurological development. However, a statistically significant association between ultrasound and left-handedness among males has been found in three studies. Thus, there is still need for more research.

Birth Weight↗
PubMed2000

Hemispheric asymmetries of cortico-cortical connections in human hand motor areas.

OBJECTIVE: To evaluate possible functional asymmetries of the motor cortex on the hand-dominant versus the non-dominant hemisphere. METHODS: We assessed the handedness of 15 consenting volunteers using the Edinburgh Inventory. They were divided in two groups: 9 right-handers and 6 left-handers. We used single- and paired-transcranial magnetic stimulation (TMS) to measure the relaxed and active motor threshold and the ipsilateral cortico-cortical inhibition and facilitation curve for both hand motor areas. We looked for hemispheric asymmetries of variables related to the side of stimulation (dominant versus non-dominant) and to handedness. RESULTS: We found no significant intra- or intergroup hemispheric asymmetry for the relaxed and active thresholds. Among the right-handers, the cortico-cortical inhibition and facilitation curve showed an increased amount of facilitation in the dominant as compared with the non-dominant hand area. No such changes were seen among the left-handers. Both the dominant and the non-dominant hand areas of the right-handers showed more inhibition and less facilitation on the cortico-cortical inhibition and facilitation curve than the corresponding areas of left-handers. CONCLUSION: In the right-handers, paired TMS studies showed a functional asymmetry of the motor cortex between the dominant and the non-dominant hand. The left-handers did not show this lateralization. Under TMS investigation their motor cortex function appeared different from that of right-handers.

Adult↗
PubMed1981

On the distribution of nonrighthandedness among twins and their families.

In 773 three-generation families of twins, individual probability of nonrighthandedness (NRH) depends significantly on the handedness of that individual's parents. The parents of twins are much more often NRH than are their nontwinbearing siblings. The twins and their siblings apparently inherit the excess liability for NRH shown by their parents. Monozygotic (MZ) pairs are significantly about twice as often concordant (casewise) for handedness as dizygotic (DZ) pairs. Overall, the best-fitting mode of transmission is autosomal, NRH dominant to RH with penetrance of about 50% in the heterozygote, or multifactorial, with heritability of 60-70%. Under the major-gene approach, heterogeneity seems likely, with about one-third of the families showing no NRH outside of the twin sibships. MZ/DZ concordance ratio is about four in those families, suggestive of recessive inheritance. A 1.16-fold excess of NRH in twins compared to their siblings, and a 1.8-fold excess in the second-born members of same-sex discordant paris, leaves open the possibility that a minor portion of NRH in twins may be secondary to transient hypoxia and/or acidosis.

Adolescent↗
PubMed2000

Determinants of neurological dysfunction in first episode schizophrenia.

BACKGROUND: Although it is well recognized that individuals with schizophrenia display evidence of subtle neurological impairment, its aetiopathological and clinical significance continues to be unclear. METHODS: Patients presenting with a first episode of schizophrenia or schizophreniform psychosis (DSM-IV criteria) were examined using two previously validated neurological examinations. The majority (N = 35) were examined prior to their 'first ever' dose of neuroleptic while the remaining patients (N = 21) had been medicated for less than one month. The manner in which neurological functioning is influenced by symptomatology and handedness was ascertained. RESULTS: The majority of patients who were examined neuroleptic-naive displayed evidence of neurodysfunction. A combination of relative hand preference and symptomatology explained a significant proportion of the variance in neurological functioning. Mixed handedness among adults at the time of first presentation with schizophrenia was associated with more severe neurological impairment and a history of poorer scholastic attainment and pre-morbid social adjustment. CONCLUSIONS: Neurological soft signs are an intrinsic part of schizophrenia rather than a direct consequence of treatment. Early developmental processes are associated with the level of subsequent neurological impairment in first episode schizophrenia. However, symptomatology appears to have an influence on the apparent severity of neurological impairment.

Acute Disease↗
PubMed2003

Formation of racemate and mesocate complexes from an achiral tripodal ligand containing three benzimidazole groups.

Two complexes of the achiral tripodal ligand tris(1-benzimidazolylethyl)amine (nteb), viz., [Mn(nteb)(2)(H(2)O)(2)](ClO(4))(2).CH(3)OH, 1, and [Ag(2)(nteb)(2)](CF(3)CO(2))(2).2H(2)O, 2, have been synthesized and characterized by IR, (1)H NMR, and EPR spectroscopy (1), electrospray mass spectrometry, thermogravimetric analysis, and X-ray crystallography. Compound 1 contains chiral complex cations due to the same handedness of two nteb ligands (deltadelta or lambdalambda) but crystallizes as a racemate, while 2 contains a dinuclear mesocate because of the opposite handedness (deltalambda) of two nteb ligands. Crystal data for 1: space group P(-)1 with a = 9.471(4) A, b = 16.884(7) A, c = 19.906(8) A, alpha = 77.930(7) degrees, beta = 88.063(7) degrees, gamma = 89.706(7) degrees, V = 3111(2) A(3), and Z = 2. Crystal data for 2: space group P(-)1 with a = 9.3390(12) A, b = 10.2168(13) A, c = 16.382(2) A, alpha = 75.721(3) degrees, beta = 87.857(3) degrees, gamma = 71.738(3) degrees, V = 1437.2(3) A(3), and Z = 1. In 1, water serves as an auxiliary ligand, connected to one imidazole N atom of each nteb ligand through a H-bridge; the cationic complexes are associated intermolecularly via pi.pi interactions. In contrast to 1, the coordination to the Ag(+) ions in 2 occurs in a heterochiral manner and produces a dinuclear mesocate.

Journal Article↗
PubMed2002

Photoinduced supramolecular chirality in amorphous azobenzene polymer films.

Supramolecular chirality was optically induced in amorphous and achiral azobenzene polymer films by irradiation of a laser beam with elliptical polarization. The chirality resulted from helical orientation of azobenzene chromophores by a combined process of circular and linear polarization. The helix-handedness could be controlled by incident light-handedness.

Journal Article↗
PubMed2006

Two-dimensional surface chirality control by solvent-induced helicity inversion of a helical polyacetylene on graphite.

We report the direct evidence for the macromolecular helicity inversion of a helical poly(phenylacetylene) bearing l- or d-alanine pendants with a long alkyl chain in different solvents by atomic force microscopy observations of the diastereomeric helical structures. The diastereomeric helical poly(phenylacetylene)s induced in polar and nonpolar solvents self-assembled into ordered, two-dimensional helix bundles with controlled molecular packing, helical pitch, and handedness on graphite upon exposure of each solvent. The macromolecular helicity deposited on graphite from a polar solvent further inverted to the opposite handedness by exposure to a specific nonpolar solvent, and these changes in the surface chirality based on the inversion of helicity could be visualized by atomic force microscopy with molecular resolution, and the results were quantified by X-ray diffraction of the oriented liquid crystalline, diastereomeric helical polymer films.

Journal Article↗
PubMed2003

A correlation between the absolute configuration of alkyl aryl sulfoxides and their helical twisting powers in nematic liquid crystals.

In this paper, for the first time, a systematic experimental and theoretical analysis of the cholesteric induction due to solutes whose chirality is originated only by a single stereogenic center has been carried out. The twisting power beta of a series of alkyl aryl sulfoxides has been determined in several nematic solvents. The sign of beta, which reflects the handedness of the induced helical arrangement of the solvent molecules, correlates with the configuration of the stereogenic sulfur in the nematic solvents E7, Phase 1083, and ZLI 2359: (S)-configurated dopants induce (M)-chiral nematics. (S)-Configurated cyclic sulfoxides, which are forced to adopt a different conformation with respect to the parent acyclic compounds, induce, instead, right-handed chiral nematics. The experimental data have been interpreted in the light of the surface chirality model, which allows the calculation of beta in terms of the molecular properties of the dopant, namely, the anisotropy and helicity of its molecular surface. The calculations reliably reproduce the behavior experimentally observed. The more flexible, open-chain compounds investigated induce chiral nematics of opposite handedness in MBBA and Phase 1053: temperature-dependent experiments point out the importance of the conformation in determining the effective sign of beta. The results have been discussed in terms of different conformation populations in these latter solvents with respect to E7, Phase 1083, and ZLI 2359.

Journal Article↗
PubMed2003

Abnormal brain lateralization in high-functioning autism.

Disturbances in lateral preference in autism are of interest because of their potential to shed light on brain maturational processes in this disorder. Forty-seven autistic individuals with a history of disordered early language development and 22 autistic individuals with normal early language acquisition were matched with 112 healthy individuals and compared on a standardized measure of lateral preference, the Edinburgh Handedness Inventory. Autistic individuals with a history of early language disturbance showed more atypical cerebral dominance than both healthy participants and autistic individuals with normal early language skills. The data indicated maturational disturbances in establishing lateral preference rather than increased rates of left handedness. Atypical establishment of cerebral dominance may be one cause of disordered language development in autism.

Adolescent↗